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Sample records for iri model results

  1. IRIS Simplified LERF Model

    International Nuclear Information System (INIS)

    Maioli, A.; Finnicum, D.J.; Kumagai, Y.

    2004-01-01

    Westinghouse is currently conducting the pre-application licensing of the International Reactor Innovative and Secure (IRIS). One of the key aspects of the IRIS design is its safety-by-designTM philosophy and within this framework the PRA is being used as an integral part of the design process. The most ambitious risk-related goal for IRIS is to reduce the Emergency Planning Zone (EPZ) to within the exclusion area by demonstrating that the off-site doses are consistent with the US Protective Action Guidelines (PAGs) for initiation of emergency response so that the required protective actions would be limited to the exclusion area. As a first step, a model has been developed to provide a first order approximation of the Large Early Release Frequency (LERF) as a surrogate predictor of the off-site doses. A key-aspect of the LERF model development is the characterization of the possible paths of release. Four main categories have been historically pointed out: (1) Core Damage (CD ) sequences with containment bypass, (2) CD sequences with containment isolation failure, (3) CD sequences with containment failure at low pressure and (4) CD sequences with containment failure at high pressure. They have been reevaluated to account for the IRIS design features

  2. Efficient Iris Localization via Optimization Model

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2017-01-01

    Full Text Available Iris localization is one of the most important processes in iris recognition. Because of different kinds of noises in iris image, the localization result may be wrong. Besides this, localization process is time-consuming. To solve these problems, this paper develops an efficient iris localization algorithm via optimization model. Firstly, the localization problem is modeled by an optimization model. Then SIFT feature is selected to represent the characteristic information of iris outer boundary and eyelid for localization. And SDM (Supervised Descent Method algorithm is employed to solve the final points of outer boundary and eyelids. Finally, IRLS (Iterative Reweighted Least-Square is used to obtain the parameters of outer boundary and upper and lower eyelids. Experimental result indicates that the proposed algorithm is efficient and effective.

  3. IRIS PRA preliminary results and future direction

    International Nuclear Information System (INIS)

    Finnicum, D.J.; Kling, C.L.; Carelli, M.D.

    2004-01-01

    Westinghouse is currently conducting the pre-application licensing of the International Reactor Innovative and Secure (IRIS) on behalf of the IRIS Consortium. One of the key aspects of the IRIS design is the concept of safety-by-design. The PRA (Probabilistic Risk Analysis) is being used as an integral part of the design process. As part of this effort, a PRA of the initial design was generated to address 2 key areas. First, the IRIS PRA supported the evaluation of IRIS design issues by providing a solid risk basis for design and analyses required for the pre-licensing evaluation of the IRIS design. The PRA provides the tool for quantifying the benefit of the safety-by-design approach. Second, the current PRA task is beginning the preparation of the more complete PRA analyses and documentation eventually required for Design Certification. One of the key risk-related goals for IRIS is to reduce the EPZ (Emergency Protection Zone) to within the exclusion area by demonstrating that the off-site doses are consistent with the US Protective Action Guidelines (PAGs) for initiation of emergency response so that the required protective actions would be limited to the exclusion area. The results of the preliminary PRA indicated a core damage frequency of 1.2 E-08 for internal initiators. This is a very good result but much work is needed to meet the ambitious goal of no emergency response. The next phase of the PRA analyses will involve a two-fold expansion of the PRA. First, as the design and analyses approach a greater level of detail, the assumptions used for the initial PRA will be reviewed and the models will be revised as needed to reflect the improved knowledge of the system design and performance. Furthermore, as the full plant design advances, the PRA will be expanded to incorporate risk associated with external challenges such as seismic and fire, and to address low power and shutdowns modes of operation. As with the initial work, the PRA will serve as a tool to

  4. CFD modeling of the IRIS pressurizer dynamic

    International Nuclear Information System (INIS)

    Sanz, Ronny R.; Montesinos, Maria E.; Garcia, Carlos; Bueno, Elizabeth D.; Mazaira, Leorlen R.; Bezerra, Jair L.; Lira, Carlos A.B. Oliveira

    2015-01-01

    Integral layout of nuclear reactor IRIS makes possible the elimination of the spray system, which is usually used to mitigate in-surge transient and also help to Boron homogenization. The study of transients with deficiencies in the Boron homogenization in this technology is very important, because they can cause disturbances in the reactor power and insert a strong reactivity in the core. The detailed knowledge of the behavior of multiphase multicomponent flows is challenging due to the complex phenomena and interactions at the interface. In this context, the CFD modeling is employed in the design of equipment in the nuclear industry as it allows predicting accidents or predicting their performance in dissimilar applications. The aim of the present research is to model the IRIS pressurizer's dynamic using the commercial CFD code CFX. A symmetric tri dimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The model considers the coexistence of four phases and also takes into account the heat losses. The relationships for interfacial mass, energy, and momentum transport are programmed and incorporated into CFX. Moreover, two subdomains and several additional variables are defined to monitoring the boron dilution sequences and condensation-evaporation rates in different control volumes. For transient states a non - equilibrium stratification in the pressurizer is considered. This paper discusses the model developed and the behavior of the system for representative transients sequences. The results of analyzed transients of IRIS can be applied to the design of pressurizer internal structures and components. (author)

  5. CFD modeling of the IRIS pressurizer dynamic

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Ronny R.; Montesinos, Maria E.; Garcia, Carlos; Bueno, Elizabeth D.; Mazaira, Leorlen R., E-mail: rsanz@instec.cu, E-mail: mmontesi@instec.cu, E-mail: cgh@instec.cu, E-mail: leored1984@gmail.com [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Bezerra, Jair L.; Lira, Carlos A.B. Oliveira, E-mail: jair.lima@ufpe.br, E-mail: cabol@ufpe.br [Universida Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2015-07-01

    Integral layout of nuclear reactor IRIS makes possible the elimination of the spray system, which is usually used to mitigate in-surge transient and also help to Boron homogenization. The study of transients with deficiencies in the Boron homogenization in this technology is very important, because they can cause disturbances in the reactor power and insert a strong reactivity in the core. The detailed knowledge of the behavior of multiphase multicomponent flows is challenging due to the complex phenomena and interactions at the interface. In this context, the CFD modeling is employed in the design of equipment in the nuclear industry as it allows predicting accidents or predicting their performance in dissimilar applications. The aim of the present research is to model the IRIS pressurizer's dynamic using the commercial CFD code CFX. A symmetric tri dimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The model considers the coexistence of four phases and also takes into account the heat losses. The relationships for interfacial mass, energy, and momentum transport are programmed and incorporated into CFX. Moreover, two subdomains and several additional variables are defined to monitoring the boron dilution sequences and condensation-evaporation rates in different control volumes. For transient states a non - equilibrium stratification in the pressurizer is considered. This paper discusses the model developed and the behavior of the system for representative transients sequences. The results of analyzed transients of IRIS can be applied to the design of pressurizer internal structures and components. (author)

  6. IRIS

    International Nuclear Information System (INIS)

    Malfaro, W.; Zygmont, A.

    1991-01-01

    This paper discusses development of ISOLATION RESET INFORMATION SYSTEM (IRIS), an expert system to aid nuclear plant operators during plant transients known as automatic containment isolations. IRIS is implemented using the Personal Consultant Plus expert system shell, taking advantage of the dBase III Plus interface. The design of IRIS is discussed as well as the system's current state of development. The use of expert systems for training operators is discussed. The importance of gaining regulatory acceptance of expert systems is presented. This issue will ultimately determine the extent of expert system use in nuclear applications

  7. Computational model for transient studies of IRIS pressurizer behavior

    International Nuclear Information System (INIS)

    Rives Sanz, R.; Montesino Otero, M.E.; Gonzalez Mantecon, J.; Rojas Mazaira, L.

    2014-01-01

    International Reactor Innovative and Secure (IRIS) excels other Small Modular Reactor (SMR) designs due to its innovative characteristics regarding safety. IRIS integral pressurizer makes the design of larger pressurizer system than the conventional PWR, without any additional cost. The IRIS pressurizer volume of steam can provide enough margins to avoid spray requirement to mitigate in-surge transient. The aim of the present research is to model the IRIS pressurizer's dynamic using the commercial finite volume Computational Fluid Dynamic code CFX 14. A symmetric tridimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The model considers the coexistence of three phases: liquid, steam, and vapor bubbles in liquid volume. Additionally, it takes into account the heat losses between the pressurizer and primary circuit. The relationships for interfacial mass, energy, and momentum transport are programmed and incorporated into CFX by using expressions in CFX Command Language (CCL) format. Moreover, several additional variables are defined for improving the convergence and allow monitoring of boron dilution sequences and condensation-evaporation rate in different control volumes. For transient states a non - equilibrium stratification in the pressurizer is considered. This paper discusses the model developed and the behavior of the system for representative transients sequences such as the in/out-surge transients and boron dilution sequences. The results of analyzed transients of IRIS can be applied to the design of pressurizer internal structures and components. (author)

  8. Computer modeling of homogenization of boric acid in IRIS pressurizer

    International Nuclear Information System (INIS)

    Rives Sanz, Ronny; Montesinos Otero, Maria Elena; Gonzalez Mantecon, Javier

    2015-01-01

    Integral layout of nuclear reactor IRIS makes possible the elimination of the spray system; which is usually used to mitigate in-surge transient and help to boron homogenization. The study of transients with deficiencies in the boron homogenization in this technology is very important, because they can cause disturbances in the reactor power and insert a strong reactivity in the core. The aim of the present research is to model the IRIS pressurizer using the CFX code searching for designs alternatives that guaranteed its intrinsic security, focused on the phenomena before mentioned. A symmetric tri dimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The relationships are programmed and incorporated into the code. This paper discusses the model developed and the behavior of the system for representative transients sequences. The results of the analyzed IRIS transients could be applied to the design of the pressurizer internal structures and components. (Author)

  9. Porcine cadaver iris model for iris heating during corneal surgery with a femtosecond laser

    Science.gov (United States)

    Sun, Hui; Fan, Zhongwei; Wang, Jiang; Yan, Ying; Juhasz, Tibor; Kurtz, Ron

    2015-03-01

    Multiple femtosecond lasers have now been cleared for use for ophthalmic surgery, including for creation of corneal flaps in LASIK surgery. Preliminary study indicated that during typical surgical use, laser energy may pass beyond the cornea with potential effects on the iris. As a model for laser exposure of the iris during femtosecond corneal surgery, we simulated the temperature rise in porcine cadaver iris during direct illumination by the femtosecond laser. Additionally, ex-vivo iris heating due to femtosecond laser irradiation was measured with an infrared thermal camera (Fluke corp. Everett, WA) as a validation of the simulation.

  10. Combining GPS measurements and IRI model predictions

    International Nuclear Information System (INIS)

    Hernandez-Pajares, M.; Juan, J.M.; Sanz, J.; Bilitza, D.

    2002-01-01

    The free electrons distributed in the ionosphere (between one hundred and thousands of km in height) produce a frequency-dependent effect on Global Positioning System (GPS) signals: a delay in the pseudo-orange and an advance in the carrier phase. These effects are proportional to the columnar electron density between the satellite and receiver, i.e. the integrated electron density along the ray path. Global ionospheric TEC (total electron content) maps can be obtained with GPS data from a network of ground IGS (international GPS service) reference stations with an accuracy of few TEC units. The comparison with the TOPEX TEC, mainly measured over the oceans far from the IGS stations, shows a mean bias and standard deviation of about 2 and 5 TECUs respectively. The discrepancies between the STEC predictions and the observed values show an RMS typically below 5 TECUs (which also includes the alignment code noise). he existence of a growing database 2-hourly global TEC maps and with resolution of 5x2.5 degrees in longitude and latitude can be used to improve the IRI prediction capability of the TEC. When the IRI predictions and the GPS estimations are compared for a three month period around the Solar Maximum, they are in good agreement for middle latitudes. An over-determination of IRI TEC has been found at the extreme latitudes, the IRI predictions being, typically two times higher than the GPS estimations. Finally, local fits of the IRI model can be done by tuning the SSN from STEC GPS observations

  11. Fault detection in IRIS reactor secondary loop using inferential models

    International Nuclear Information System (INIS)

    Perillo, Sergio R.P.; Upadhyaya, Belle R.; Hines, J. Wesley

    2013-01-01

    The development of fault detection algorithms is well-suited for remote deployment of small and medium reactors, such as the IRIS, and the development of new small modular reactors (SMR). However, an extensive number of tests are still to be performed for new engineering aspects and components that are not yet proven technology in the current PWRs, and present some technological challenges for its deployment since many of its features cannot be proven until a prototype plant is built. In this work, an IRIS plant simulation platform was developed using a Simulink® model. The dynamic simulation was utilized in obtaining inferential models that were used to detect faults artificially added to the secondary system simulations. The implementation of data-driven models and the results are discussed. (author)

  12. New modelling strategy for IRIS dynamic response simulation

    International Nuclear Information System (INIS)

    Cammi, A.; Ricotti, M. E.; Casella, F.; Schiavo, F.

    2004-01-01

    The pressurized light water cooled, medium power (1000 MWt) IRIS (International Reactor Innovative and Secure) has been under development for four years by an international consortium of over 21 organizations from ten countries. The plant conceptual design was completed in 2001 and the preliminary design is nearing completion. The pre-application licensing process with NRC started in October, 2002 and IRIS is one of the designs considered by US utilities as part of the ESP (Early Site Permit) process. In this paper the development of an adequate modeling and simulation tool for Dynamics and Control tasks is presented. The key features of the developed simulator are: a) Modularity: the system model is built by connecting the models of its components, which are written independently of their boundary conditions; b) Openness: the code of each component model is clearly readable and close to the original equations and easily customised by the experienced user; c) Efficiency: the simulation code is fast; d) Tool support: the simulation tool is based on reliable, tested and well-documented software. To achieve these objectives, the Modelica language was used as a basis for the development of the simulator. The Modelica language is the results of recent advances in the field of object-oriented, multi-physics, dynamic system modelling. The language definition is open-source and it has already been successfully adopted in several industrial fields. To provide the required capabilities for the analysis, specific models for nuclear reactor components have been developed, to be applied for the dynamic simulation of the IRIS integral reactor, albeit keeping general validity for PWR plants. The following Modelica models have been written to satisfy the IRIS modelling requirements and are presented in this paper: neutronics point kinetic, fuel heat transfer, control rods model, including the innovative internal drive mechanism type, and a once-through type steam generator, thus

  13. Gaze Estimation for Off-Angle Iris Recognition Based on the Biometric Eye Model

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

    2013-01-01

    Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ANONYMIZED biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

  14. Appropriate Objective Functions for Quantifying Iris Mechanical Properties Using Inverse Finite Element Modeling.

    Science.gov (United States)

    Pant, Anup D; Dorairaj, Syril K; Amini, Rouzbeh

    2018-07-01

    Quantifying the mechanical properties of the iris is important, as it provides insight into the pathophysiology of glaucoma. Recent ex vivo studies have shown that the mechanical properties of the iris are different in glaucomatous eyes as compared to normal ones. Notwithstanding the importance of the ex vivo studies, such measurements are severely limited for diagnosis and preclude development of treatment strategies. With the advent of detailed imaging modalities, it is possible to determine the in vivo mechanical properties using inverse finite element (FE) modeling. An inverse modeling approach requires an appropriate objective function for reliable estimation of parameters. In the case of the iris, numerous measurements such as iris chord length (CL) and iris concavity (CV) are made routinely in clinical practice. In this study, we have evaluated five different objective functions chosen based on the iris biometrics (in the presence and absence of clinical measurement errors) to determine the appropriate criterion for inverse modeling. Our results showed that in the absence of experimental measurement error, a combination of iris CL and CV can be used as the objective function. However, with the addition of measurement errors, the objective functions that employ a large number of local displacement values provide more reliable outcomes.

  15. Computer Models for IRIS Control System Transient Analysis

    International Nuclear Information System (INIS)

    Gary D Storrick; Bojan Petrovic; Luca Oriani

    2007-01-01

    This report presents results of the Westinghouse work performed under Task 3 of this Financial Assistance Award and it satisfies a Level 2 Milestone for the project. Task 3 of the collaborative effort between ORNL, Brazil and Westinghouse for the International Nuclear Energy Research Initiative entitled 'Development of Advanced Instrumentation and Control for an Integrated Primary System Reactor' focuses on developing computer models for transient analysis. This report summarizes the work performed under Task 3 on developing control system models. The present state of the IRIS plant design--such as the lack of a detailed secondary system or I and C system designs--makes finalizing models impossible at this time. However, this did not prevent making considerable progress. Westinghouse has several working models in use to further the IRIS design. We expect to continue modifying the models to incorporate the latest design information until the final IRIS unit becomes operational. Section 1.2 outlines the scope of this report. Section 2 describes the approaches we are using for non-safety transient models. It describes the need for non-safety transient analysis and the model characteristics needed to support those analyses. Section 3 presents the RELAP5 model. This is the highest-fidelity model used for benchmark evaluations. However, it is prohibitively slow for routine evaluations and additional lower-fidelity models have been developed. Section 4 discusses the current Matlab/Simulink model. This is a low-fidelity, high-speed model used to quickly evaluate and compare competing control and protection concepts. Section 5 describes the Modelica models developed by POLIMI and Westinghouse. The object-oriented Modelica language provides convenient mechanisms for developing models at several levels of detail. We have used this to develop a high-fidelity model for detailed analyses and a faster-running simplified model to help speed the I and C development process. Section

  16. Measurements and IRI Model Predictions During the Recent Solar Minimum

    Science.gov (United States)

    Bilitza, Dieter; Brown, Steven A.; Wang, Mathew Y.; Souza, Jonas R.; Roddy, Patrick A.

    2012-01-01

    Cycle 23 was exceptional in that it lasted almost two years longer than its predecessors and in that it ended in an extended minimum period that proved all predictions wrong. Comparisons of the International Reference Ionosphere (IRI) with CHAMP and GRACE in-situ measurements of electron density during the minimum have revealed significant discrepancies at 400-500 km altitude. Our study investigates the causes for these discrepancies with the help of ionosonde and Planar Langmuir Probe (PLP) data from the Communications/Navigation Outage Forecasting System (C/NOFS) satellite. Our C/NOFS comparisons confirm the earlier CHAMP and GRACE results. But the ionosonde measurements of the F-peak plasma frequency (foF2) show generally good agreement throughout the whole solar cycle. At mid-latitude stations yearly averages of the data-model difference are within 10% and at low latitudes stations within 20%. The 60-70% differences found at 400-500 km altitude are not seen at the F peak. We will discuss how these seemingly contradicting results from the ionosonde and in situ data-model comparisons can be explained and which parameters need to be corrected in the IRI model.

  17. Multiple local feature representations and their fusion based on an SVR model for iris recognition using optimized Gabor filters

    Science.gov (United States)

    He, Fei; Liu, Yuanning; Zhu, Xiaodong; Huang, Chun; Han, Ye; Dong, Hongxing

    2014-12-01

    Gabor descriptors have been widely used in iris texture representations. However, fixed basic Gabor functions cannot match the changing nature of diverse iris datasets. Furthermore, a single form of iris feature cannot overcome difficulties in iris recognition, such as illumination variations, environmental conditions, and device variations. This paper provides multiple local feature representations and their fusion scheme based on a support vector regression (SVR) model for iris recognition using optimized Gabor filters. In our iris system, a particle swarm optimization (PSO)- and a Boolean particle swarm optimization (BPSO)-based algorithm is proposed to provide suitable Gabor filters for each involved test dataset without predefinition or manual modulation. Several comparative experiments on JLUBR-IRIS, CASIA-I, and CASIA-V4-Interval iris datasets are conducted, and the results show that our work can generate improved local Gabor features by using optimized Gabor filters for each dataset. In addition, our SVR fusion strategy may make full use of their discriminative ability to improve accuracy and reliability. Other comparative experiments show that our approach may outperform other popular iris systems.

  18. Investigation on equatorial ionospheric profiles and IRI model

    International Nuclear Information System (INIS)

    Adeniyi, J.O.

    1996-01-01

    Ionospheric profiles below the F2 peak ionisation density are compared with those of the International Reference Ionosphere (IRI). The data used are those of Ibadan (Lat. 7.4 deg N, Long. 3.9 E). The IRI model gives a much thinner bottomside F region ionisation density than what is observed experimentally, in winter; both at high and low solar activity. Similar departures are observed in the summer of both solar epoch but on a reduced scale. The closet agreement occurs during the March equinox of high solar activity. (author). 3 refs, 4 figs

  19. Computational model for transient studies of IRIS pressurizer behavior; Modelo computacional para el estudio de transitorios en el compensador de presion IRIS

    Energy Technology Data Exchange (ETDEWEB)

    Rives Sanz, R.; Montesino Otero, M.E.; Gonzalez Mantecon, J.; Rojas Mazaira, L., E-mail: mmontesi@instec.cu [Higher Institute of Technology and Applied Science, La Habana (Cuba). Department of Nuclear Engineering; Lira, C.A. Brayner de Oliveira [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2014-07-01

    International Reactor Innovative and Secure (IRIS) excels other Small Modular Reactor (SMR) designs due to its innovative characteristics regarding safety. IRIS integral pressurizer makes the design of larger pressurizer system than the conventional PWR, without any additional cost. The IRIS pressurizer volume of steam can provide enough margins to avoid spray requirement to mitigate in-surge transient. The aim of the present research is to model the IRIS pressurizer's dynamic using the commercial finite volume Computational Fluid Dynamic code CFX 14. A symmetric tridimensional model equivalent to 1/8 of the total geometry was adopted to reduce mesh size and minimize processing time. The model considers the coexistence of three phases: liquid, steam, and vapor bubbles in liquid volume. Additionally, it takes into account the heat losses between the pressurizer and primary circuit. The relationships for interfacial mass, energy, and momentum transport are programmed and incorporated into CFX by using expressions in CFX Command Language (CCL) format. Moreover, several additional variables are defined for improving the convergence and allow monitoring of boron dilution sequences and condensation-evaporation rate in different control volumes. For transient states a non - equilibrium stratification in the pressurizer is considered. This paper discusses the model developed and the behavior of the system for representative transients sequences such as the in/out-surge transients and boron dilution sequences. The results of analyzed transients of IRIS can be applied to the design of pressurizer internal structures and components. (author)

  20. IRI-2012 MODEL ADAPTABILITY ESTIMATION FOR AUTOMATED PROCESSING OF VERTICAL SOUNDING IONOGRAMS

    Directory of Open Access Journals (Sweden)

    V. D. Nikolaeva

    2014-01-01

    Full Text Available The paper deals with possibility of IRI-2012 global empirical model applying to the vertical sounding of the ionosphere semiautomatic data processing. Main ionosphere characteristics from vertical sounding data at IZMIRAN Voeikovo station in February 2013 were compared with IRI-2012 model calculation results. 2688 model values and 1866 real values of f0F2, f0E, hmF2, hmE were processed. E and F2 layers critical frequency (f0E, f0F2 and the maximum altitudes (hmF2, hmE were determined from the ionograms. Vertical profiles of the electron concentration were restored with IRI-2012 model by measured frequency and height. The model calculation was also made without the inclusion of the real vertical sounding data. Monthly averages and standard deviations (σ for the parameters f0F2, f0E, hmF2, hmE for each hour of the day were calculated according to the vertical sounding and model values. Model applicability conditions for automated processing of ionograms for subauroral ionosphere were determined. Initial IRI-2012 model can be applied in the sub-auroral ionograms processing at daytime with undisturbed conditions in the absence of sporadic ionization. In this case model calculations can be adjusted by the near-time vertical sounding data. IRI-2012 model values for f0E (in daytime and hmF2 can be applied to reduce computational costs in the systems of automatic parameters search and preliminary determination of the searching area range for the main parameters. IRI-2012 model can be used for a more accurate approximation of the real data series in the absence of the real values. In view of sporadic ionization, ionosphere models of the high latitudes must be applied with corpuscular ions formation unit.

  1. Topside electron density: comparison of experimental and IRI model profiles during low solar activity period

    International Nuclear Information System (INIS)

    Alazo, K.; Coisson, P.; Radicella, S.M.

    2003-01-01

    The pattern of the topside electron density profiles is not yet very well represented by the IRI model. In this work the topside profiles obtained by the ISIS-2 satellite during low solar activity conditions are compared to those modeled by IRI. We take the quantitative parameter ε to measure the deviation of the model from the observed profiles. The results showed that the IRI overestimation of the topside profile is higher for low dip latitudes. The dispersion of the epsilon values is from 40 to 140%, more in equinoctial months and some lower for Winter. The best modeling is about 20% to 40% in middle and high latitudes of the North Hemisphere. (author)

  2. IRI related data and model services at NSSDC

    Science.gov (United States)

    Bilitza, D.; Papitashvili, N.; King, J.

    NASA's National Space Science Data Center (NSSDC) provides internet access to a large number of space physics data sets and models. We will review and explain the different products and services that might be of interest to the IRI community. Data can be obtained directly through anonymous ftp or through the SPyCAT WWW interface to a large volume of space physics data on juke-box type mass storage devices. A newly developed WWW system, the ATMOWeb, provides browse and sub-setting capabilities for selected atmospheric and thermospheric data. NSSDC maintains an archive of space physics models that includes a subset of ionospheric models. The model software can be retrieved via anonymous ftp. A selection of the most frequently requested models can be run on-line through special WWW interfaces. Currently supported models include the International Reference Ionosphere (IRI), the Mass Spectrometer and Incoherent Scatter (MSIS) atmospheric model, the International Geomagnetic Reference Field (IGRF) and the AE-8/AP-8 radiation belt models. In this article special emphasis will be given to the IRI interface and its various input/output options. Several new options and a Java-based plotting capability were recently added to the Web interface.

  3. Toward accurate and fast iris segmentation for iris biometrics.

    Science.gov (United States)

    He, Zhaofeng; Tan, Tieniu; Sun, Zhenan; Qiu, Xianchao

    2009-09-01

    Iris segmentation is an essential module in iris recognition because it defines the effective image region used for subsequent processing such as feature extraction. Traditional iris segmentation methods often involve an exhaustive search of a large parameter space, which is time consuming and sensitive to noise. To address these problems, this paper presents a novel algorithm for accurate and fast iris segmentation. After efficient reflection removal, an Adaboost-cascade iris detector is first built to extract a rough position of the iris center. Edge points of iris boundaries are then detected, and an elastic model named pulling and pushing is established. Under this model, the center and radius of the circular iris boundaries are iteratively refined in a way driven by the restoring forces of Hooke's law. Furthermore, a smoothing spline-based edge fitting scheme is presented to deal with noncircular iris boundaries. After that, eyelids are localized via edge detection followed by curve fitting. The novelty here is the adoption of a rank filter for noise elimination and a histogram filter for tackling the shape irregularity of eyelids. Finally, eyelashes and shadows are detected via a learned prediction model. This model provides an adaptive threshold for eyelash and shadow detection by analyzing the intensity distributions of different iris regions. Experimental results on three challenging iris image databases demonstrate that the proposed algorithm outperforms state-of-the-art methods in both accuracy and speed.

  4. Improvements and new features in the IRI-2000 model

    International Nuclear Information System (INIS)

    Bilitza, D.

    2002-01-01

    This paper describes the changes that were implemented in the new version of the COSPAR/URSI International Reference Ionosphere (IRI-2000). These changes are: (1) two new options for the electron density in the D-region, (2) a better functional description of the electron density in the E-F merging region, (3) inclusion of the F1 layer occurrence probability as a new parameter, (4) a new model for the bottomside parameters B 0 and B 1 that greatly improves the representation at low and equatorial latitudes during high solar activities, (5) inclusion of a model for foF2 storm-time updating, (6) a new option for the electron temperature in the topside ionosphere, and (7) inclusion of a model for the equatorial F region ion drift. The main purpose of this paper is to provide the IRI users with examples of the effects of these changes. (author)

  5. Comparison of ionospheric profile parameters with IRI-2012 model over Jicamarca

    International Nuclear Information System (INIS)

    Bello, S A; Abdullah, M; Hamid, N S A; Reinisch, B W

    2017-01-01

    We used the hourly ionogram data obtained from Jicamarca station (12° S, 76.9° W, dip latitude: 1.0° N) an equatorial region to study the variation of the electron density profile parameters: maximum height of F2-layer ( hm F2), bottomside thickness ( B0 ) and shape ( B1 ) parameter of F-layer. The period of study is for the year 2010 (solar minimum period).The diurnal monthly averages of these parameters are compared with the updated IRI-2012 model. The results show that hm F2 is highest during the daytime than nighttime. The variation in hmF2 was observed to modulate the thickness of the bottomside F2-layer. The observed hm F2 and B0 post-sunset peak is as result of the upward drift velocity of ionospheric plasma. We found a close agreement between IRI-CCIR hm F2 model and observed hm F2 during 0000-0700 LT while outside this period the model predictions deviate significantly with the observational values. Significant discrepancies are observed between the IRI model options for B0 and the observed B0 values. Specifically, the modeled values do not show B0 post-sunset peak. A fairly good agreement was observed between the observed B1 and IRI model options (ABT-2009 and Bill 2000) for B1 . (paper)

  6. Comparison of ionospheric profile parameters with IRI-2012 model over Jicamarca

    Science.gov (United States)

    Bello, S. A.; Abdullah, M.; Hamid, N. S. A.; Reinisch, B. W.

    2017-05-01

    We used the hourly ionogram data obtained from Jicamarca station (12° S, 76.9° W, dip latitude: 1.0° N) an equatorial region to study the variation of the electron density profile parameters: maximum height of F2-layer (hmF2), bottomside thickness (B0) and shape (B1) parameter of F-layer. The period of study is for the year 2010 (solar minimum period).The diurnal monthly averages of these parameters are compared with the updated IRI-2012 model. The results show that hmF2 is highest during the daytime than nighttime. The variation in hmF2 was observed to modulate the thickness of the bottomside F2-layer. The observed hmF2 and B0 post-sunset peak is as result of the upward drift velocity of ionospheric plasma. We found a close agreement between IRI-CCIR hmF2 model and observed hmF2 during 0000-0700 LT while outside this period the model predictions deviate significantly with the observational values. Significant discrepancies are observed between the IRI model options for B0 and the observed B0 values. Specifically, the modeled values do not show B0 post-sunset peak. A fairly good agreement was observed between the observed B1 and IRI model options (ABT-2009 and Bill 2000) for B1.

  7. Iris Image Classification Based on Hierarchical Visual Codebook.

    Science.gov (United States)

    Zhenan Sun; Hui Zhang; Tieniu Tan; Jianyu Wang

    2014-06-01

    Iris recognition as a reliable method for personal identification has been well-studied with the objective to assign the class label of each iris image to a unique subject. In contrast, iris image classification aims to classify an iris image to an application specific category, e.g., iris liveness detection (classification of genuine and fake iris images), race classification (e.g., classification of iris images of Asian and non-Asian subjects), coarse-to-fine iris identification (classification of all iris images in the central database into multiple categories). This paper proposes a general framework for iris image classification based on texture analysis. A novel texture pattern representation method called Hierarchical Visual Codebook (HVC) is proposed to encode the texture primitives of iris images. The proposed HVC method is an integration of two existing Bag-of-Words models, namely Vocabulary Tree (VT), and Locality-constrained Linear Coding (LLC). The HVC adopts a coarse-to-fine visual coding strategy and takes advantages of both VT and LLC for accurate and sparse representation of iris texture. Extensive experimental results demonstrate that the proposed iris image classification method achieves state-of-the-art performance for iris liveness detection, race classification, and coarse-to-fine iris identification. A comprehensive fake iris image database simulating four types of iris spoof attacks is developed as the benchmark for research of iris liveness detection.

  8. IRIS Licensing Status

    International Nuclear Information System (INIS)

    Kling, Charles L.; Carelli, Mario D.

    2006-01-01

    The International Reactor Innovative and Secure (IRIS) nuclear power plant is well into the pre-application review process with the US NRC and has accomplished its first near term goal of obtaining US NRC feedback on the long term testing program. To date, the IRIS team has submitted to the US NRC a number of documents patterned after the Evaluation Model Development and Assessment Process (EMDAP) outlined in Regulatory Guide 1,203. They have covered a detailed description of IRIS, initial safety analysis results, PIRT development for limiting transients, scaling analysis and a description of the test program. The IRIS Safety-by-Desing TM intrinsically eliminates and/or significantly reduces the consequences of traditional LWR accidents. In addition, the fewer passive safety systems are similar in principle to those of the US NRC approved AP1000 design. For these reasons, the IRIS testing program only needs to include those features unique to the IRIS design. NRC feedback was that the planned test program appeared to be complete and could generate sufficient information to support a Design Certification (DC) submittal. The US NRC has also stated that a DC application must include complete information regarding the test program. On this basis the IRIS team has initiated an aggressive program to conduct IRIS testing to support a DC submittal by the end of 2008. Subsequent US NRC review should be expeditious because of the AP1000 precedent, allowing IRIS to obtain its Final Design Approval (FDA) in 2012; thereby, maintaining its goal of deployment in the 2015-2017 time frame. The next steps in the pre-application review process will be to provide the US NRC with a road map of the anticipated IRIS licensing process, a review of current licensing requirements showing that IRIS meets or exceeds all current criteria and information to support the long term goal of redefining the Emergency Planning Zone (EPZ)

  9. Comparative Study of foF2 Measurements with IRI-2007 Model Predictions During Extended Solar Minimum

    Science.gov (United States)

    Zakharenkova, I. E.; Krankowski, A.; Bilitza, D.; Cherniak, Iu.V.; Shagimuratov, I.I.; Sieradzki, R.

    2013-01-01

    The unusually deep and extended solar minimum of cycle 2324 made it very difficult to predict the solar indices 1 or 2 years into the future. Most of the predictions were proven wrong by the actual observed indices. IRI gets its solar, magnetic, and ionospheric indices from an indices file that is updated twice a year. In recent years, due to the unusual solar minimum, predictions had to be corrected downward with every new indices update. In this paper we analyse how much the uncertainties in the predictability of solar activity indices affect the IRI outcome and how the IRI values calculated with predicted and observed indices compared to the actual measurements.Monthly median values of F2 layer critical frequency (foF2) derived from the ionosonde measurements at the mid-latitude ionospheric station Juliusruh were compared with the International Reference Ionosphere (IRI-2007) model predictions. The analysis found that IRIprovides reliable results that compare well with actual measurements, when the definite (observed and adjusted) indices of solar activityare used, while IRI values based on earlier predictions of these indices noticeably overestimated the measurements during the solar minimum.One of the principal objectives of this paper is to direct attention of IRI users to update their solar activity indices files regularly.Use of an older index file can lead to serious IRI overestimations of F-region electron density during the recent extended solar minimum.

  10. Checking the new IRI model: The bottomside B parameters

    International Nuclear Information System (INIS)

    Mosert, M.; Buresova, D.; Miro, G.; Lazo, B.; Ezquer, R.

    2003-01-01

    Electron density profiles obtained at Pruhonice (50.0, 15.0), El Arenosillo (37.1, 353.2) and Havana (23, 278) were used to check the bottom-side B parameters BO (thickness parameter) and B1 (shape parameter) predicted by the new IRI - 2000 version. The electron density profiles were derived from ionograms using the ARP technique. The data base includes daytime and nighttime ionograms recorded under different seasonal and solar activity conditions. Comparisons with IRI predictions were also done. The analysis shows that: a) The parameter B1 given by IRI 2000 reproduces better the observed ARP values than the IRI-90 version and b) The observed BO values are in general well reproduced by both IRI versions: IRI-90 and IRI-2000. (author)

  11. Checking the new IRI model The bottomside B parameters

    CERN Document Server

    Mosert, M; Ezquer, R; Lazo, B; Miro, G

    2002-01-01

    Electron density profiles obtained at Pruhonice (50.0, 15.0), El Arenosillo (37.1, 353.2) and Havana (23, 278) were used to check the bottom-side B parameters BO (thickness parameter) and B1 (shape parameter) predicted by the new IRI - 2000 version. The electron density profiles were derived from ionograms using the ARP technique. The data base includes daytime and nighttime ionograms recorded under different seasonal and solar activity conditions. Comparisons with IRI predictions were also done. The analysis shows that: a) The parameter B1 given by IRI 2000 reproduces better the observed ARP values than the IRI-90 version and b) The observed BO values are in general well reproduced by both IRI versions: IRI-90 and IRI-2000.

  12. Comparison of the observed results of the electron density profiles with the IRI90

    International Nuclear Information System (INIS)

    Zhang Manlian; Radicella, S.M.; Dai Kailiang

    1996-01-01

    The daily and composite profiles and the thickness parameter of the electron density profiles are compared with the results of IRI90 for the stations of Ramey (15.8 deg. N, 292.9 deg. E), Wuchang (30.6 deg. N, 114.3 deg. E), Chongqing (29.5 deg. N, 106.4 deg. E) and Wrumchi (43.8 deg. N, 87.6 deg. E). It is found that the electron density profiles produced by IRI90, both with the old Standard B0 and the new Gulyaeva-B0 thickness parameter, are too thick below F2-peak compared with the observed results. It is also shown that the IRI90 results show a very poor agreement with the observed results for the intermediate (F1) layer of the ionosphere. (author). 1 ref., 4 figs,

  13. Comparison of experimental slant electron content and IRI model for moderate solar activity conditions

    International Nuclear Information System (INIS)

    Cabrera, M.A.; Ezquer, R.G.; Mosert, M.; Jadur, C.A.

    2002-01-01

    The International Reference Ionosphere model only gives the vertical electron content (VTEC). In this paper the slant electron content (SEC) for the ATS 6 satellite - Palehua (21.4 deg. N, 201.9 deg. E) radio signal path for a middle solar activity year is calculated. To this end, IRI model is used to obtain the electron density at different points of the signal path. Equinoxes and solstices are considered. Measurements obtained with Faraday rotation technique at Palehua are compared with the modelled values. Although overestimation was observed for night hours, the results show good SEC predictions for several hours at period of maximum ionisation, suggesting that would be possible to model the STEC using IRI. (author)

  14. Analysis of different containment models for IRIS small break LOCA, using GOTHIC and RELAP5 codes

    International Nuclear Information System (INIS)

    Papini, Davide; Grgic, Davor; Cammi, Antonio; Ricotti, Marco E.

    2011-01-01

    Advanced nuclear water reactors rely on containment behaviour in realization of some of their passive safety functions. Steam condensation on containment walls, where non-condensable gas effects are significant, is an important feature of the new passive containment concepts, like the AP600/1000 ones. In this work the international reactor innovative and secure (IRIS) was taken as reference, and the relevant condensation phenomena involved within its containment were investigated with different computational tools. In particular, IRIS containment response to a small break LOCA (SBLOCA) was calculated with GOTHIC and RELAP5 codes. A simplified model of IRIS containment drywell was implemented with RELAP5 according to a sliced approach, based on the two-pipe-with-junction concept, while it was addressed with GOTHIC using several modelling options, regarding both heat transfer correlations and volume and thermal structure nodalization. The influence on containment behaviour prediction was investigated in terms of drywell temperature and pressure response, heat transfer coefficient (HTC) and steam volume fraction distribution, and internal recirculating mass flow rate. The objective of the paper is to preliminarily compare the capability of the two codes in modelling of the same postulated accident, thus to check the results obtained with RELAP5, when applied in a situation not covered by its validation matrix (comprising SBLOCA and to some extent LBLOCA transients, but not explicitly the modelling of large dry containment volumes). The option to include or not droplets in fluid mass flow discharged to the containment was the most influencing parameter for GOTHIC simulations. Despite some drawbacks, due, e.g. to a marked overestimation of internal natural recirculation, RELAP5 confirmed its capability to satisfactorily model the basic processes in IRIS containment following SBLOCA.

  15. Ordinal measures for iris recognition.

    Science.gov (United States)

    Sun, Zhenan; Tan, Tieniu

    2009-12-01

    Images of a human iris contain rich texture information useful for identity authentication. A key and still open issue in iris recognition is how best to represent such textural information using a compact set of features (iris features). In this paper, we propose using ordinal measures for iris feature representation with the objective of characterizing qualitative relationships between iris regions rather than precise measurements of iris image structures. Such a representation may lose some image-specific information, but it achieves a good trade-off between distinctiveness and robustness. We show that ordinal measures are intrinsic features of iris patterns and largely invariant to illumination changes. Moreover, compactness and low computational complexity of ordinal measures enable highly efficient iris recognition. Ordinal measures are a general concept useful for image analysis and many variants can be derived for ordinal feature extraction. In this paper, we develop multilobe differential filters to compute ordinal measures with flexible intralobe and interlobe parameters such as location, scale, orientation, and distance. Experimental results on three public iris image databases demonstrate the effectiveness of the proposed ordinal feature models.

  16. Comparison of GPS derived TEC with the TEC predicted by IRI 2012 model in the southern Equatorial Ionization Anomaly crest within the Eastern Africa region

    Science.gov (United States)

    Sulungu, Emmanuel D.; Uiso, Christian B. S.; Sibanda, Patrick

    2018-04-01

    We have compared the TEC obtained from the IRI-2012 model with the GPS derived TEC data recorded within southern crest of the EIA in the Eastern Africa region using the monthly means of the 5 international quiet days for equinoxes and solstices months for the period of 2012 - 2013. GPS-derived TEC data have been obtained from the Africa array and IGS network of ground based dual-frequency GPS receivers from four stations (Kigali (1.95°S, 30.09°E; Geom. Lat. 11.63°S), Malindi (2.99°S, 40.19°E; Geom. Lat. 12.42°S), Mbarara (0.60°S, 30.74°E; Geom. Lat. 10.22°S) and Nairobi (1.22°S, 36.89°E; Geom. Lat. 10.69°S)) located within the EIA crest in this region. All the three options for topside Ne of IRI-2012 model and ABT-2009 for bottomside thickness have been used to compute the IRI TEC. Also URSI coefficients were considered in this study. These results are compared with the TEC estimated from GPS measurements. Correlation Coefficients between the two sets of data, the Root-Mean Square Errors (RMSE) of the IRI-TEC from the GPS-TEC, and the percentage RMSE of the IRI-TEC from the GPS-TEC have been computed. Our general results show that IRI-2012 model with all three options overestimates the GPS-TEC for all seasons and at all stations, and IRI-2001 overestimates GPS-TEC more compared with other options. IRI-Neq and IRI-01-corr are closely matching in most of the time. The observation also shows that, GPS TEC are underestimated by TEC from IRI model during noon hours, especially during equinoctial months. Further, GPS-TEC values and IRI-TEC values using all the three topside Ne options show very good correlation (above 0.8). On the other hand, the TEC using IRI-Neq and IRI-01- corr had smaller deviations from the GPS-TEC compared to the IRI-2001.

  17. Coupled RELAP5/GOTHIC model for IRIS SBLOCA analysis

    International Nuclear Information System (INIS)

    Grgic, D.; Cavlina, N.; Bajs, T.; Oriani, L.; Conway, L. E.

    2004-01-01

    Historically, accident analyses for nuclear power plants have been successfully performed using system thermal-hydraulics codes. In case of complex problems involving solution of thermal-hydraulics together with other disciplines such as: reactor physics, chemistry, aerosol dynamics, metallurgy; system codes are usually not enough or prediction capability can be improved by addition of separate computational models. The similar is true in case when interaction of different solution domains should be calculated (e.g. primary system and containment) with different physical models, or very different spatial or time discretization. An interesting example of such kind of interaction of different evaluation models is given by containment and reactor coolant system accident analysis of the IRIS. Previously, the different physical phenomena involved in the analyses and the need for different spatial and time discretization have led to the development of separate and specialized computer codes and evaluation models for the analysis of these two systems. The different mathematical models available are typically used independently based on external iterations and appropriate boundary conditions. In fact, the interaction of the reactor coolant system and containment is typically analyzed with two independent runs. First the mass and energy (MandE) released from the reactor versus time is calculated by a system code using a conservatively (low), bounding, containment pressure, and then the containment response is calculated for that MandE release versus time. This approach is usually sufficient for current LWR reactors. In new advanced passive reactor systems, interaction of the coolant system and containment is much more important since it impacts on the evolution of the transients. Therefore, a different modeling strategy is needed. The most straightforward approach for analyzing interacting systems would be to adopt a single evaluation model for the two coupled systems

  18. Modeling IrisCode and its variants as convex polyhedral cones and its security implications.

    Science.gov (United States)

    Kong, Adams Wai-Kin

    2013-03-01

    IrisCode, developed by Daugman, in 1993, is the most influential iris recognition algorithm. A thorough understanding of IrisCode is essential, because over 100 million persons have been enrolled by this algorithm and many biometric personal identification and template protection methods have been developed based on IrisCode. This paper indicates that a template produced by IrisCode or its variants is a convex polyhedral cone in a hyperspace. Its central ray, being a rough representation of the original biometric signal, can be computed by a simple algorithm, which can often be implemented in one Matlab command line. The central ray is an expected ray and also an optimal ray of an objective function on a group of distributions. This algorithm is derived from geometric properties of a convex polyhedral cone but does not rely on any prior knowledge (e.g., iris images). The experimental results show that biometric templates, including iris and palmprint templates, produced by different recognition methods can be matched through the central rays in their convex polyhedral cones and that templates protected by a method extended from IrisCode can be broken into. These experimental results indicate that, without a thorough security analysis, convex polyhedral cone templates cannot be assumed secure. Additionally, the simplicity of the algorithm implies that even junior hackers without knowledge of advanced image processing and biometric databases can still break into protected templates and reveal relationships among templates produced by different recognition methods.

  19. Results of the IRIS UV Burst Survey, Part I: Active Regions Tracked Limb to Limb

    Science.gov (United States)

    Madsen, C. A.; DeLuca, E.

    2017-12-01

    We present results from the first phase of an effort to thoroughly characterize UV bursts within the Interface Region Imaging Spectrograph (IRIS) data catalogue. The observational signatures of these phenomena include dramatically intensified and broadened NUV/FUV emission line profiles with absorption features from cool metallic ions. These properties suggest that UV bursts originate from plasma at transition region temperatures (≥ 80,000 K) which is deeply embedded in the cool lower chromosphere ( 5,000 K). Rigorously characterizing the energetic and dynamical properties of UV bursts is crucial since they have considerable potential to heat active region chromospheres and could provide critical constraints for models of magnetic reconnection in these regions. The survey first focuses on IRIS observations of active regions tracked from limb to limb. All observations consist of large field-of-view raster scans of 320 or 400 steps each, which allow for widespread detection of many burst profiles at the expense of having limited short-term time evolution information. We detect bursts efficiently by applying a semi-automated single-Gaussian fitting technique to Si IV 1393.8 Å emission profiles that isolates the distinct burst population in a 4-D parameter space. The robust sample of NUV/FUV burst spectra allows for precise constraints of properties critical for modeling reconnection in the chromosphere, including outflow kinetic energy, density estimates from intensity ratios of Si IV 1402.8 Å and O IV 1401.2 Å emission lines, and coincident measures of emission in other wavelengths. We also track burst properties throughout the lifetimes of their host active regions, noting changes in detection rate and preferential location as the active regions evolve. Finally, the tracked active region observations provide a unique opportunity to investigate line-of-sight effects on observed UV burst spectral properties, particularly the strength of Ni II 1393.3 Å absorption

  20. New methods in iris recognition.

    Science.gov (United States)

    Daugman, John

    2007-10-01

    This paper presents the following four advances in iris recognition: 1) more disciplined methods for detecting and faithfully modeling the iris inner and outer boundaries with active contours, leading to more flexible embedded coordinate systems; 2) Fourier-based methods for solving problems in iris trigonometry and projective geometry, allowing off-axis gaze to be handled by detecting it and "rotating" the eye into orthographic perspective; 3) statistical inference methods for detecting and excluding eyelashes; and 4) exploration of score normalizations, depending on the amount of iris data that is available in images and the required scale of database search. Statistical results are presented based on 200 billion iris cross-comparisons that were generated from 632500 irises in the United Arab Emirates database to analyze the normalization issues raised in different regions of receiver operating characteristic curves.

  1. Full-sized plates irradiation with high UMo fuel loading. Final results of IRIS 1 experiment

    International Nuclear Information System (INIS)

    Huet, F.; Marelle, V.; Noirot, J.; Sacristan, P.; Lemoine, P.

    2003-01-01

    As a part of the French UMo Group qualification program, IRIS 1 experiment contained full-sized plates with high uranium loading in the meat of 8 g.cm -3 . The fuel particles consisted of 7 and 9 wt% Mo-uranium alloys ground powders. The plate were irradiated at OSIRIS reactor in IRIS device up to 67.5% peak burnup within the range of 136 W.cm - '2 for the heat flux and 72 deg. C for the cladding temperature. After each reactor cycle the plates thickness were measured. The results show no swelling behaviour differences versus burnup between UMo7 and UMo9 plates. The maximum plate swelling for peak burnup location remains lower than 6%. The wide set of PIE has shown that, within the studied irradiation conditions, the interaction product have a global formulation of '(U-Mo)Al -7 ' and that there is no aluminium dissolution in UMo particles. IRIS1 experiment, as the first step of the UMo fuel qualification for research reactor, has established the good behaviour of UMo7 and UMo9 high uranium loading full-sized plate within the tested conditions. (author)

  2. IRI performance models for recently constructed low and medium-traffic two lane roads of the province of Biscay

    Energy Technology Data Exchange (ETDEWEB)

    Perez Acebo, H.; Gonzalo-Orden, H.

    2016-07-01

    Reliable pavement prediction models are needed for pavement management systems (PMS), as they are a key component to forecast future conditions of the pavement and to prioritize maintenance, rehabilitation and reconstruction strategies. The International Roughness Index (IRI) is the most used parameter worldwide for calibrating pavement roughness and measures reasonably the ride comfort perceived by occupants of passenger cars. The Regional Government of Biscay also collects this value on the road network under its control These surveys are carried out regularly in the XXI century. Several IRI performance models have been proposed by different authors and administrations, varying greatly in their comprehensiveness, the ability to predict performance with accurancy and input data requirements. The aim of this paper is to develop a roughness performance model for Biscay's roads, based on availablbe IRI data, taking into account heavy traffic volume and the age of pavement. Local characteristics as climate conditions and average rainfall are not considered. IRI performance models have been suggested for regional two lane highways with low and medium heavy traffic constructed in the last 20 years in the province of Biscay, with no treatments during their life. They can be applied for flexible pavements, but no logical coherent results have been concluded for semi-rigid pavements. (Author)

  3. Iris recognition via plenoptic imaging

    Science.gov (United States)

    Santos-Villalobos, Hector J.; Boehnen, Chris Bensing; Bolme, David S.

    2017-11-07

    Iris recognition can be accomplished for a wide variety of eye images by using plenoptic imaging. Using plenoptic technology, it is possible to correct focus after image acquisition. One example technology reconstructs images having different focus depths and stitches them together, resulting in a fully focused image, even in an off-angle gaze scenario. Another example technology determines three-dimensional data for an eye and incorporates it into an eye model used for iris recognition processing. Another example technology detects contact lenses. Application of the technologies can result in improved iris recognition under a wide variety of scenarios.

  4. Video-based noncooperative iris image segmentation.

    Science.gov (United States)

    Du, Yingzi; Arslanturk, Emrah; Zhou, Zhi; Belcher, Craig

    2011-02-01

    In this paper, we propose a video-based noncooperative iris image segmentation scheme that incorporates a quality filter to quickly eliminate images without an eye, employs a coarse-to-fine segmentation scheme to improve the overall efficiency, uses a direct least squares fitting of ellipses method to model the deformed pupil and limbic boundaries, and develops a window gradient-based method to remove noise in the iris region. A remote iris acquisition system is set up to collect noncooperative iris video images. An objective method is used to quantitatively evaluate the accuracy of the segmentation results. The experimental results demonstrate the effectiveness of this method. The proposed method would make noncooperative iris recognition or iris surveillance possible.

  5. Ionospheric Tomography from a Reference GPS/MET Experiment Through the IRI Model

    Directory of Open Access Journals (Sweden)

    Lung-Chih Tsai

    2006-01-01

    Full Text Available In earlier studies, we implemented the Multiplicative Algebraic Reconstruction Technique (MART to reconstruct two-dimensional ionospheric structures from measured TECs through the receptions of the GPS-to-LEO signals and/or the NNSS-to-ground beacon signals. To examine the accuracy of the reconstructed image we need ground-based validation systems which are difficult to obtain. However, such comparative investigation is needed if one aims to improve tomography inverse techniques and algorithms. In this study, we propose a simulation scheme to carry out this task. We first simulate the GPS-to-LEO TEC measurements through the IRI model by integrating electron densities along the ¡§straight¡¨ ray occultation paths between the GPS and LEO satellite obtained from the real GPS/MET experiment. Contiguous tomographic images are then derived by the MART algorithm within the ¡§reference¡¨ GPS/MET experiment. They are verified by comparison with the ¡§true¡¨ IRI-modelled ionosphere. We show that simulation/reference results can be used to find the optimal reconstruction strategy in space-based ionospheric tomography.

  6. Aphakia correction with retropupillary fixated iris-claw lens (Artisan – long-term results

    Directory of Open Access Journals (Sweden)

    Schallenberg M

    2013-12-01

    Full Text Available Maurice Schallenberg,1,2 Dirk Dekowski,1 Angela Hahn,1 Thomas Laube,1,3 Klaus-Peter Steuhl,1 Daniel Meller11Department of Ophthalmology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany; 2HELIOS Klinikum Wuppertal, Wuppertal, Germany; 3Zentrum für Augenheilkunde PD Dr Laube, Düsseldorf, GermanyPurpose: To evaluate the technique, safety, and efficacy of the retropupillary implantation of iris-claw intraocular lenses in a long-term follow-up study.Patients and methods: This retrospective study included 31 eyes of 31 patients who underwent an Artisan aphakic intraocular lens implantation between January 2006 and February 2011 at the University Hospital Essen, Essen, Germany and at the Zentrum für Augenheilkunde PD Dr Laube, Düsseldorf, Germany. Preoperative data collected included demographics, etiology of aphakia, previous surgeries, preoperative eye pathology, intraocular pressure, clinical signs of endothelial cell loss, and best corrected visual acuity. Operative data and postoperative outcomes included the best corrected visual acuity, lens position, intraocular pressure, pigment dispersion, clinical signs of endothelial cell loss, development of macular edema, and other complications.Results: Thirty-one patients were included. The mean follow-up was 25.2 months (range: 4–48 months. The mean best corrected visual acuity postoperatively was 0.64 logarithm of the minimum angle of resolution (logMAR and varied from 0 logMAR to 3 logMAR. Some patients had a low visual acuity preoperatively because of preoperative eye pathologies. In 22 patients the visual acuity improved, in two patients the visual acuity remained unchanged, and seven patients showed a decreased visual acuity. Complications were peaked pupils (n=10 and retinal detachment in one case. Four patients showed an iris atrophy and high intraocular pressure was observed only in one patient. Subluxation of the intraocular lens, endothelial cell loss, and

  7. Assessment of the NeQuick-2 and IRI-Plas 2017 models using global and long-term GNSS measurements

    Science.gov (United States)

    Okoh, Daniel; Onwuneme, Sylvester; Seemala, Gopi; Jin, Shuanggen; Rabiu, Babatunde; Nava, Bruno; Uwamahoro, Jean

    2018-05-01

    The global ionospheric models NeQuick and IRI-Plas have been widely used. However, their uncertainties are not clear at global scale and long term. In this paper, a climatologic assessment of the NeQuick and IRI-Plas models is investigated at a global scale from global navigation satellite system (GNSS) observations. GNSS observations from 36 globally distributed locations were used to evaluate performances of both NeQuick-2 and IRI-Plas 2017 models from January 2006 to July 2017, covering more than the 11-year period of a solar cycle. An hourly interval of diurnal profiles computed on monthly basis was used to measure deviations of the model estimations from corresponding GNSS VTEC observations. Results show that both models are fairly accurate in trends with the GNSS measurements. The NeQuick predictions were generally better than the IRI-Plas predictions in most of the stations and the times. The mean annual prediction errors for the IRI-Plas model typically varied from about 3 TECU at the high latitude stations to about 12 TECU at the low latitude stations, while for the NeQuick the values are respectively about 2-7 TECU. Out of a total 4497 months in which GNSS data were available for all the stations put together for the entire period covered in this work, the NeQuick model was observed to perform better in about 83% of the months while the IRI-Plas performed better in about 17% of the months. The IRI-Plas generally performed better than the NeQuick at certain locations (e.g. DAV1, KERG, and ADIS). For both models, the most of the deviations were witnessed during local daytimes and during seasons that receive maximum solar radiation for various locations. In particular, the IRI-Plas model predictions were improved during periods of increased solar activity at the low latitude stations. The IRI-Plas model overestimates the GNSS VTEC values, except during high solar activity years at some high latitude stations. The NeQuick underestimates the TEC values during

  8. Comparison of COSMIC measurements with the IRI-2007 model over the eastern Mediterranean region

    Directory of Open Access Journals (Sweden)

    P. Vryonides

    2013-05-01

    Full Text Available This paper presents a comparison of the International Reference Ionosphere (IRI-2007 model over the eastern Mediterranean region with peak ionospheric characteristics (foF2–hmF2 and electron density profiles measured by FORMOSAT-3/COSMIC satellites in terms of GPS radio occultation technique and the Cyprus digisonde. In the absence of systematic ionosonde measurements over this area, COSMIC measurements provide an opportunity to perform such a study by considering observations for year 2010 to investigate the behaviour of the IRI-2007 model over the eastern Mediterranean area.

  9. Performance of Solar Proxy Options of IRI-Plas Model for Equinox Seasons

    Science.gov (United States)

    Sezen, Umut; Gulyaeva, Tamara L.; Arikan, Feza

    2018-02-01

    International Reference Ionosphere (IRI) is the most acclaimed climatic model of the ionosphere. Since 2009, the range of the IRI model has been extended to the Global Positioning System (GPS) orbital height of 20,000 km in the plasmasphere. The new model, which is called IRI extended to Plasmasphere (IRI-Plas), can input not only the ionosonde foF2 and hmF2 but also the GPS-total electron content (TEC). IRI-Plas has been provided at www.ionolab.org, where online computation of ionospheric parameters is accomplished through a user-friendly interface. The solar proxies that are available in IRI-Plas can be listed as sunspot number (SSN1), SSN2, F10.7, global electron content (GEC), TEC, IG, Mg II, Lyman-α, and GEC_RZ. In this study, ionosonde foF2 data are compared with IRI-Plas foF2 values with the Consultative Committee International Radio (CCIR) and International Union of Radio Science (URSI) model choices for each solar proxy, with or without the GPS-TEC input for the equinox months of October 2011 and March 2015. It has been observed that the best fitting model choices in Root Mean Square (RMS) and Normalized RMS (NRMS) sense are the Jet Propulsion Laboratory global ionospheric maps-TEC input with Lyman-α solar proxy option for both months. The input of TEC definitely lowers the difference between the model and ionosonde foF2 values. The IG and Mg II solar proxies produce similar model foF2 values, and they usually are the second and third best fits to the ionosonde foF2 for the midlatitude ionosphere. In high-latitude regions, Jet Propulsion Laboratory global ionospheric map-TEC inputs to IRI-Plas with Lyman-α, GEC_RZ, and TEC solar proxies are the best choices. In equatorial region, the best fitting solar proxies are IG, Lyman-α, and Mg II.

  10. TEC variability near northern EIA crest and comparison with IRI model

    Science.gov (United States)

    Aggarwal, Malini

    2011-10-01

    Monthly median values of hourly total electron content (TEC) is obtained with GPS at a station near northern anomaly crest, Rajkot (geog. 22.29°N, 70.74°E; geomag. 14.21°N, 144.9°E) to study the variability of low latitude ionospheric behavior during low solar activity period (April 2005 to March 2006). The TEC exhibit characteristic features like day-to-day variability, semiannual anomaly and noon bite out. The observed TEC is compared with latest International Reference Ionosphere (IRI) - 2007 model using options of topside electron density, NeQuick, IRI01-corr and IRI-2001 by using both URSI and CCIR coefficients. A good agreement of observed and predicted TEC is found during the daytime with underestimation at other times. The predicted TEC by NeQuick and IRI01-corr is closer to the observed TEC during the daytime whereas during nighttime and morning hours, IRI-2001 shows lesser discrepancy in all seasons by both URSI and CCIR coefficients.

  11. Using scale heights derived from bottomside ionograms for modelling the IRI topside profile

    Directory of Open Access Journals (Sweden)

    B. W. Reinisch

    2004-01-01

    Full Text Available Groundbased ionograms measure the Chapman scale height HT at the F2-layer peak that is used to construct the topside profile. After a brief review of the topside model extrapolation technique, comparisons are presented between the modeled profiles with incoherent scatter radar and satellite measurements for the mid latitude and equatorial ionosphere. The total electron content TEC, derived from measurements on satellite beacon signals, is compared with the height-integrated profiles ITEC from the ionograms. Good agreement is found with the ISR profiles and with results using the low altitude TOPEX satellite. The TEC values derived from GPS signal analysis are systematically larger than ITEC. It is suggested to use HT , routinely measured by a large number of Digisondes around the globe, for the construction of the IRI topside electron density profile.

  12. Thailand low and equatorial F 2-layer peak electron density and comparison with IRI-2007 model

    Science.gov (United States)

    Wichaipanich, N.; Supnithi, P.; Tsugawa, T.; Maruyama, T.

    2012-06-01

    Ionosonde measurements obtained at two Thailand ionospheric stations, namely Chumphon (10.72°N, 99.37°E, dip 3.0°N) and Chiang Mai (18.76°N, 98.93°E, dip 12.7°N) are used to examine the variation of the F 2-layer peak electron density ( N m F 2) which is derived from the F 2-layer critical frequency, f o f 2. Measured data from September 2004 to August 2005 (a period of low solar activity) are analyzed based on the diurnal and seasonal variation and then compared with IRI-2007 model predictions. Our results show that, in general, the diurnal and seasonal variations of the N m F 2 predicted by the IRI (URSI and CCIR options) model show a feature generally similar to the observed N m F 2. Underestimation mostly occurs in all seasons except during the September equinox and the December solstice at Chumphon, and the September equinox and the March equinox at Chiang Mai, when they overestimate those measured. The best agreement between observation and prediction occurs during the pre-sunrise to post-sunrise hours. The best agreement of the %PD values of both the options occurs during the March equinox, while the agreement is the worst during the September equinox. The N m F 2 values predicted by the CCIR option show a smaller range of deviation than the N m F 2 values predicted by the URSI option. During post-sunset to morning hours (around 21:00-09:00 LT), the observed N m F 2 at both stations are almost identical for the periods of low solar activity. However, during daytime, the observed N m F 2 at Chumphon is lower than that at Chiang Mai. The difference between these two stations can be explained by the equatorial ionospheric anomaly (EIA). These results are important for future improvements of the IRI model for N m F 2 over Southeast Asia, especially for the areas covered by Chumphon and Chiang Mai stations.

  13. Modeling and Experimental Tests on the Hydraulically Driven Control Rod option for IRIS Reactor

    International Nuclear Information System (INIS)

    Cammi, Antonio; Ricotti, Marco E.; Vitulo, Alessia

    2004-01-01

    The adoption of Internal Control Rod Drive Mechanisms (ICRDMs) represents a valuable alternative to classical, external CRDMs based on electro-magnetic devices, as adopted in current PWRs. The advantages on the safety features of the reactor are apparent: inherent elimination of the Rod Ejection accidents and of possible concerns about the vessel head penetrations. A further positive feedback on the design is the reduction of the primary system overall dimensions. Within the frame of the ICRDM concepts, the Hydraulically Driven Control Rod solution is investigated as a possible option for the IRIS integral reactor. After a brief comparison of the solutions currently proposed for integral reactors, the configuration of the Hydraulic Control Rod device for IRIS, made up by an external movable piston and an internal fixed cylinder, is described. A description of the whole control system is reported as well. Particular attention is devoted to the Control Rod profile characterization, performed by means of a Computational Fluid Dynamics (CFD) analysis. The investigation of the system behavior has been carried out, including the dynamic equilibrium and its stability properties, the withdrawal and insertion step movement and the sensitivity study on command time periods. A suitable dynamic model has been set up for the mentioned purposes: the models corresponding to the various Control Rod system devices have been written in an Object-Oriented language (Modelica), thus allowing an easy implementation of such a system into the simulator for the whole reactor. Finally, a preliminary low pressure, low temperature, reduced length experimental facility has been built. Tests on HDCR stability and operational transients have been performed. The results are compared with the dynamic system model and CFD simulation model, showing good agreement between simulations and experimental data. During these preliminary tests, the control system performed correctly, allowing stable dynamic

  14. Iris Recognition Using Wavelet

    Directory of Open Access Journals (Sweden)

    Khaliq Masood

    2013-08-01

    Full Text Available Biometric systems are getting more attention in the present era. Iris recognition is one of the most secure and authentic among the other biometrics and this field demands more authentic, reliable and fast algorithms to implement these biometric systems in real time. In this paper, an efficient localization technique is presented to identify pupil and iris boundaries using histogram of the iris image. Two small portions of iris have been used for polar transformation to reduce computational time and to increase the efficiency of the system. Wavelet transform is used for feature vector generation. Rotation of iris is compensated without shifts in the iris code. System is tested on Multimedia University Iris Database and results show that proposed system has encouraging performance.

  15. Development of Camera Model and Geometric Calibration/validation of Xsat IRIS Imagery

    Science.gov (United States)

    Kwoh, L. K.; Huang, X.; Tan, W. J.

    2012-07-01

    XSAT, launched on 20 April 2011, is the first micro-satellite designed and built in Singapore. It orbits the Earth at altitude of 822 km in a sun synchronous orbit. The satellite carries a multispectral camera IRIS with three spectral bands - 0.52~0.60 mm for Green, 0.63~0.69 mm for Red and 0.76~0.89 mm for NIR at 12 m resolution. In the design of IRIS camera, the three bands were acquired by three lines of CCDs (NIR, Red and Green). These CCDs were physically separated in the focal plane and their first pixels not absolutely aligned. The micro-satellite platform was also not stable enough to allow for co-registration of the 3 bands with simple linear transformation. In the camera model developed, this platform stability was compensated with 3rd to 4th order polynomials for the satellite's roll, pitch and yaw attitude angles. With the camera model, the camera parameters such as the band to band separations, the alignment of the CCDs relative to each other, as well as the focal length of the camera can be validated or calibrated. The results of calibration with more than 20 images showed that the band to band along-track separation agreed well with the pre-flight values provided by the vendor (0.093° and 0.046° for the NIR vs red and for green vs red CCDs respectively). The cross-track alignments were 0.05 pixel and 5.9 pixel for the NIR vs red and green vs red CCDs respectively. The focal length was found to be shorter by about 0.8%. This was attributed to the lower operating temperature which XSAT is currently operating. With the calibrated parameters and the camera model, a geometric level 1 multispectral image with RPCs can be generated and if required, orthorectified imagery can also be produced.

  16. A Novel Iris Segmentation Scheme

    Directory of Open Access Journals (Sweden)

    Chen-Chung Liu

    2014-01-01

    Full Text Available One of the key steps in the iris recognition system is the accurate iris segmentation from its surrounding noises including pupil, sclera, eyelashes, and eyebrows of a captured eye-image. This paper presents a novel iris segmentation scheme which utilizes the orientation matching transform to outline the outer and inner iris boundaries initially. It then employs Delogne-Kåsa circle fitting (instead of the traditional Hough transform to further eliminate the outlier points to extract a more precise iris area from an eye-image. In the extracted iris region, the proposed scheme further utilizes the differences in the intensity and positional characteristics of the iris, eyelid, and eyelashes to detect and delete these noises. The scheme is then applied on iris image database, UBIRIS.v1. The experimental results show that the presented scheme provides a more effective and efficient iris segmentation than other conventional methods.

  17. Results of radiotherapy in case of juvenile xanthogranuloma of the iris

    International Nuclear Information System (INIS)

    Mueller, R.P.; Juenemann, G.

    1983-01-01

    The juvenile xanthogranuloma is a rare, benign, cutaneous disease occurring in infants and young children which can be situated in about 10% of the cases on the eye and preferentially on the iris. The reason for consulting an ophthalmologist is mostly a recurrent unilateral hyphemia which is typical for this disease. The diagnosis of the juvenile xanthogranuloma has to be established clinically, based on the characteristic alterations of the iris - heterochromia, vascularized tumor or diffuse thickening of the iris - and the possibly increased intraocular pressure. In order to avoid the deleting consequences of an uncontrollable secondary glaucoma, radiotherapy with a total dose of 300 to 400 cGy combined with a mild local steroid treatment has to be undertaken immediately, if possible. Taking into consideration the indications of literature, the value of a low-dose radiotherapy for this disease shall be demonstrated by five own cases in all of which the concerned eye could be healed and preserved. (orig.) [de

  18. Off-Angle Iris Correction Methods

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Villalobos, Hector J [ORNL; Thompson, Joseph T [ORNL; Karakaya, Mahmut [ORNL; Boehnen, Chris Bensing [ORNL

    2016-01-01

    In many real world iris recognition systems obtaining consistent frontal images is problematic do to inexperienced or uncooperative users, untrained operators, or distracting environments. As a result many collected images are unusable by modern iris matchers. In this chapter we present four methods for correcting off-angle iris images to appear frontal which makes them compatible with existing iris matchers. The methods include an affine correction, a retraced model of the human eye, measured displacements, and a genetic algorithm optimized correction. The affine correction represents a simple way to create an iris image that appears frontal but it does not account for refractive distortions of the cornea. The other method account for refraction. The retraced model simulates the optical properties of the cornea. The other two methods are data driven. The first uses optical flow to measure the displacements of the iris texture when compared to frontal images of the same subject. The second uses a genetic algorithm to learn a mapping that optimizes the Hamming Distance scores between off-angle and frontal images. In this paper we hypothesize that the biological model presented in our earlier work does not adequately account for all variations in eye anatomy and therefore the two data-driven approaches should yield better performance. Results are presented using the commercial VeriEye matcher that show that the genetic algorithm method clearly improves over prior work and makes iris recognition possible up to 50 degrees off-angle.

  19. Comparison of midlatitude ionospheric F region peak parameters and topside Ne profiles from IRI2012 model prediction with ground-based ionosonde and Alouette II observations

    Science.gov (United States)

    Gordiyenko, G. I.; Yakovets, A. F.

    2017-07-01

    The ionospheric F2 peak parameters recorded by a ground-based ionosonde at the midlatitude station Alma-Ata [43.25N, 76.92E] were compared with those obtained using the latest version of the IRI model (http://omniweb.gsfc.nasa.gov/vitmo/iri2012_vitmo.html). It was found that for the Alma-Ata (Kazakhstan) location, the IRI2012 model describes well the morphology of seasonal and diurnal variations of the ionospheric critical frequency (foF2) and peak density height (hmF2) monthly medians. The model errors in the median foF2 prediction (percentage deviations between the median foF2 values and their model predictions) were found to vary approximately in the range from about -20% to 34% and showed a stable overestimation in the median foF2 values for daytime in January and July and underestimation for day- and nighttime hours in the equinoctial months. The comparison between the ionosonde hmF2 and IRI results clearly showed that the IRI overestimates the nighttime hmF2 values for March and September months, and the difference is up to 30 km. The daytime Alma-Ata hmF2 data were found to be close to the IRI predictions (deviations are approximately ±10-15 km) in winter and equinoctial months, except in July when the observed hmF2 values were much more (from approximately 50-200 km). The comparison between the Alouette foF2 data and IRI predictions showed mixed results. In particular, the Alouette foF2 data showed a tendency to be overestimated for daytime in winter months similar to the ionosonde data; however, the overestimated foF2 values for nighttime in the autumn equinox were in disagreement with the ionosonde observations. There were large deviations between the observed hmF2 values and their model predictions. The largest deviations were found during winter and summer (up to -90 km). The comparison of the Alouette II electron density profiles with those predicted by the adapted IRI2012 model in the altitude range hmF2 of the satellite position showed a great

  20. Effective Solar Indices for Ionospheric Modeling: A Review and a Proposal for a Real-Time Regional IRI

    Science.gov (United States)

    Pignalberi, A.; Pezzopane, M.; Rizzi, R.; Galkin, I.

    2018-01-01

    The first part of this paper reviews methods using effective solar indices to update a background ionospheric model focusing on those employing the Kriging method to perform the spatial interpolation. Then, it proposes a method to update the International Reference Ionosphere (IRI) model through the assimilation of data collected by a European ionosonde network. The method, called International Reference Ionosphere UPdate (IRI UP), that can potentially operate in real time, is mathematically described and validated for the period 9-25 March 2015 (a time window including the well-known St. Patrick storm occurred on 17 March), using IRI and IRI Real Time Assimilative Model (IRTAM) models as the reference. It relies on foF2 and M(3000)F2 ionospheric characteristics, recorded routinely by a network of 12 European ionosonde stations, which are used to calculate for each station effective values of IRI indices IG_{12} and R_{12} (identified as IG_{{12{eff}}} and R_{{12{eff}}}); then, starting from this discrete dataset of values, two-dimensional (2D) maps of IG_{{12{eff}}} and R_{{12{eff}}} are generated through the universal Kriging method. Five variogram models are proposed and tested statistically to select the best performer for each effective index. Then, computed maps of IG_{{12{eff}}} and R_{{12{eff}}} are used in the IRI model to synthesize updated values of foF2 and hmF2. To evaluate the ability of the proposed method to reproduce rapid local changes that are common under disturbed conditions, quality metrics are calculated for two test stations whose measurements were not assimilated in IRI UP, Fairford (51.7°N, 1.5°W) and San Vito (40.6°N, 17.8°E), for IRI, IRI UP, and IRTAM models. The proposed method turns out to be very effective under highly disturbed conditions, with significant improvements of the foF2 representation and noticeable improvements of the hmF2 one. Important improvements have been verified also for quiet and moderately disturbed

  1. Iris Recognition Using Feature Extraction of Box Counting Fractal Dimension

    Science.gov (United States)

    Khotimah, C.; Juniati, D.

    2018-01-01

    Biometrics is a science that is now growing rapidly. Iris recognition is a biometric modality which captures a photo of the eye pattern. The markings of the iris are distinctive that it has been proposed to use as a means of identification, instead of fingerprints. Iris recognition was chosen for identification in this research because every human has a special feature that each individual is different and the iris is protected by the cornea so that it will have a fixed shape. This iris recognition consists of three step: pre-processing of data, feature extraction, and feature matching. Hough transformation is used in the process of pre-processing to locate the iris area and Daugman’s rubber sheet model to normalize the iris data set into rectangular blocks. To find the characteristics of the iris, it was used box counting method to get the fractal dimension value of the iris. Tests carried out by used k-fold cross method with k = 5. In each test used 10 different grade K of K-Nearest Neighbor (KNN). The result of iris recognition was obtained with the best accuracy was 92,63 % for K = 3 value on K-Nearest Neighbor (KNN) method.

  2. The effect of gender on eye colour variation in European populations and an evaluation of the IrisPlex prediction model

    DEFF Research Database (Denmark)

    Pietroni, Carlotta; Andersen, Jeppe D.; Johansen, Peter

    2014-01-01

    In two recent studies of Spanish individuals [1,2], gender was suggested as a factor that contributes to human eye colour variation. However, gender did not improve the predictive accuracy on blue, intermediate and brown eye colours when gender was included in the IrisPlex model [3]. In this stud...... and their corresponding predictive values using the IrisPlex prediction model [4]. The results suggested that maximum three (rs12913832, rs1800407, rs16891982) of the six IrisPlex SNPs are useful in practical forensic genetic casework.......In two recent studies of Spanish individuals [1,2], gender was suggested as a factor that contributes to human eye colour variation. However, gender did not improve the predictive accuracy on blue, intermediate and brown eye colours when gender was included in the IrisPlex model [3]. In this study......12203592). A quantitative eye colour score (Pixel Index of the Eye: PIE-score) was calculated based on digital eye images using the custom made DIAT software. The results were compared with those of Danish and Swedish population samples. As expected, we found HERC2 rs12913832 as the main predictor of human...

  3. Dynamic modeling of primary and secondary systems of IRIS reactor for transient analysis using SIMULINK

    International Nuclear Information System (INIS)

    Magalhaes, Mardson Alencar de Sa; Lira, Carlos Alberto Brayner de Oliveira; Silva, Mario Augusto Bezerra da

    2011-01-01

    The IRIS project has significantly advanced in the last few years in response to a demand for a new generation reactor, that could fulfill the essential requirements for a future nuclear power plant: better economics, safety-by-design, low proliferation risk and environmental sustainability. IRIS reactor is a integral type PWR in which all primary components are arranged inside the pressure vessel. This configuration involves important changes in relation to a conventional PWR. These changes require several studies to comply with the safe operational limits for the reactor. In this paper, a study has been conducted to develop a dynamic model (named MODIRIS) for transient analysis, implemented in the MATLAB'S software SIMULINK, allowing the analysis of IRIS behavior by considering the neutron point kinetics for power production. The methodology is based on generating a set of differential equations of neutronic and thermal-hydraulic balances which describes the dynamics of the primary circuit, as well as a set of differential equations describing the dynamics of secondary circuit. The equations and initialization parameters at full power were into the SIMULINK and the code was validated by the confrontation with RELAP simulations for a transient of feedwater reduction in the steam generators. (author)

  4. Variations of B0 and B1 with the solar quiet Sq-current system and comparison with IRI-2012 model at Ilorin

    Science.gov (United States)

    Bello, S. A.; Abdullah, M.; Hamid, N. S. A.; Yoshikawa, A.; Olawepo, A. O.

    2017-07-01

    The ionospheric thickness (B0) and shape (B1) are bottomside profile parameters introduced by the International Reference Ionosphere (IRI) model. We have validated these parameters with the latest version of the IRI-2012 model and compared them with the solar quiet of geomagnetic H-component (SqH). The B0, B1 and SqH are calculated from the measurements obtained from digisonde DPS-4 sounder and the Magnetic Data Acquisition System (MAGDAS) magnetometer, respectively at Ilorin (geo latitude 8.50°N, geo longitude 4.68°E, and Magnetic dip 4.1°S) an equatorial station in the African sector. The study was for the year 2010, a year of low solar activity (with 27-day averaged solar index, F10.7 = 80 sfu). The results show that B0 for the entire months was higher during the daytime than during the night time. On the other hand, the magnitude of B1during the daytime period is lower than nighttime values and exhibit oscillatory pattern. By comparing the experimental observations of the profile parameters with the IRI-2012 model prediction, we found that B0 was fairly represented by the IRI model options during the nighttime period while discrepancies exist between the model estimates and the experimental values during the morning till midday. A close agreement exists between the observed B1 values and IRI model options. We observed a positive and significant correlation coefficient between B0 and SqH indicating a plausible relationship between these parameters while a weak and negative correlation coefficient between B1 and SqH was observed. We concluded that the difference in the relationship of SqH and the profile parameters B0 and B1 observed can be attributed to their sensitivity to the electric field which is responsible for the E × B drift which in turn modulate the height of the F2.

  5. Subluxation of iris-sutured intraocular lenses and results of a closed chamber technique for repositioning after penetrating keratoplasty.

    Science.gov (United States)

    Jabbur, Nada S; Akpek, Esen Karamursel; Stark, Walter J

    2005-05-01

    To describe subluxation of iris-fixated intraocular lenses (IOLs) after penetrating keratoplasty (PK) as a postoperative complication and report the long-term outcomes of a closed-chamber refixation technique used in the management. This was a retrospective, noncomparative interventional case series in which 19 consecutive patient charts with a subluxated iris-fixated IOL after PK were retrospectively reviewed. Fourteen of the patients underwent surgery using a closed-chamber refixation technique. These patients were evaluated for visual outcome and surgical complications associated with the procedure. In 13 patients, postoperative follow-up was available. In all 13 cases, the fixated IOL appeared stable and remained well positioned during a follow-up period of 56 months (range, 6-122). All patients (100%) achieved improved uncorrected visual acuity. The postoperative visual acuity ranged from 20/20 to 20/100 with a mean of 20/40. Vitreous hemorrhage occurred in 1 patient, and an additional patient required a second surgery using the same technique. Both of these patients did well with a final visual acuity of 20/40 and 20/50, respectively. Subluxation of iris-fixated IOL after PK can occur as a postoperative complication. The technique that we herein describe enables secure refixation of subluxated IOLs and yields favorable long-term results.

  6. An automatic iris occlusion estimation method based on high-dimensional density estimation.

    Science.gov (United States)

    Li, Yung-Hui; Savvides, Marios

    2013-04-01

    Iris masks play an important role in iris recognition. They indicate which part of the iris texture map is useful and which part is occluded or contaminated by noisy image artifacts such as eyelashes, eyelids, eyeglasses frames, and specular reflections. The accuracy of the iris mask is extremely important. The performance of the iris recognition system will decrease dramatically when the iris mask is inaccurate, even when the best recognition algorithm is used. Traditionally, people used the rule-based algorithms to estimate iris masks from iris images. However, the accuracy of the iris masks generated this way is questionable. In this work, we propose to use Figueiredo and Jain's Gaussian Mixture Models (FJ-GMMs) to model the underlying probabilistic distributions of both valid and invalid regions on iris images. We also explored possible features and found that Gabor Filter Bank (GFB) provides the most discriminative information for our goal. Finally, we applied Simulated Annealing (SA) technique to optimize the parameters of GFB in order to achieve the best recognition rate. Experimental results show that the masks generated by the proposed algorithm increase the iris recognition rate on both ICE2 and UBIRIS dataset, verifying the effectiveness and importance of our proposed method for iris occlusion estimation.

  7. Observation and modelling of the Fe XXI line profile observed by IRIS during the impulsive phase of flares

    Science.gov (United States)

    Polito, V.; Testa, P.; De Pontieu, B.; Allred, J. C.

    2017-12-01

    The observation of the high temperature (above 10 MK) Fe XXI 1354.1 A line with the Interface Region Imaging Spectrograph (IRIS) has provided significant insights into the chromospheric evaporation process in flares. In particular, the line is often observed to be completely blueshifted, in contrast to previous observations at lower spatial and spectral resolution, and in agreement with predictions from theoretical models. Interestingly, the line is also observed to be mostly symmetric and with a large excess above the thermal width. One popular interpretation for the excess broadening is given by assuming a superposition of flows from different loop strands. In this work, we perform a statistical analysis of Fe XXI line profiles observed by IRIS during the impulsive phase of flares and compare our results with hydrodynamic simulations of multi-thread flare loops performed with the 1D RADYN code. Our results indicate that the multi-thread models cannot easily reproduce the symmetry of the line and that some other physical process might need to be invoked in order to explain the observed profiles.

  8. Intraoperative floppy iris and prevalence of intraoperative complications: results from ophthalmic surgery outcomes database.

    Science.gov (United States)

    Vollman, David E; Gonzalez-Gonzalez, Luis A; Chomsky, Amy; Daly, Mary K; Baze, Elizabeth; Lawrence, Mary

    2014-06-01

    To estimate the prevalence of untoward events during cataract surgery with the use of pupillary expansion devices and intraoperative floppy iris (IFIS). Retrospective analysis of 4923 cataract surgery cases from the Veterans Affairs Ophthalmic Surgical Outcomes Data Project. Outcomes from 5 Veterans Affairs medical centers were analyzed, including use of alpha-blockers (both selective and nonselective), IFIS, intraoperative iris trauma, intraoperative iris prolapse, posterior capsular tear, anterior capsule tear, intraoperative vitreous prolapse, and use of pupillary expansion devices. P values were calculated using the χ(2) test. A total of 1254 patients (25.5%) took alpha-blockers preoperatively (selective, 587; nonselective, 627; both, 40). Of these 1254 patients, 428 patients (34.1%) had documented IFIS. However, 75.2% of patients with IFIS (428/569) had taken alpha-blockers preoperatively (P < .00001). A total of 430 patients (8.7%) had a pupillary expansion device used during their cataract surgery, of which 186 patients (43.4%) had IFIS (P < .0001). Eighty-six patients with IFIS had at least 1 intraoperative complication and 39 patients with IFIS had more than 1 intraoperative complication (P < .001). The use of either selective or nonselective alpha-antagonists preoperatively demonstrated a significant risk of IFIS. Nonselective alpha-antagonists caused IFIS at a higher prevalence than previously reported. This study did demonstrate statistically significant increased odds of surgical complications in patients with IFIS vs those without IFIS in all groups (those taking selective and nonselective alpha-antagonists and also those not taking medications). Published by Elsevier Inc.

  9. The effect of gender on eye colour variation in European populations and an evaluation of the IrisPlex prediction model.

    Science.gov (United States)

    Pietroni, Carlotta; Andersen, Jeppe D; Johansen, Peter; Andersen, Mikkel M; Harder, Stine; Paulsen, Rasmus; Børsting, Claus; Morling, Niels

    2014-07-01

    In two recent studies of Spanish individuals, gender was suggested as a factor that contributes to human eye colour variation. However, gender did not improve the predictive accuracy on blue, intermediate and brown eye colours when gender was included in the IrisPlex model. In this study, we investigate the role of gender as a factor that contributes to eye colour variation and suggest that the gender effect on eye colour is population specific. A total of 230 Italian individuals were typed for the six IrisPlex SNPs (rs12913832, rs1800407, rs12896399, rs1393350, rs16891982 and rs12203592). A quantitative eye colour score (Pixel Index of the Eye: PIE-score) was calculated based on digital eye images using the custom made DIAT software. The results were compared with those of Danish and Swedish population samples. As expected, we found HERC2 rs12913832 as the main predictor of human eye colour independently of ancestry. Furthermore, we found gender to be significantly associated with quantitative eye colour measurements in the Italian population sample. We found that the association was statistically significant only among Italian individuals typed as heterozygote GA for HERC2 rs12913832. Interestingly, we did not observe the same association in the Danish and Swedish population. This indicated that the gender effect on eye colour is population specific. We estimated the effect of gender on quantitative eye colour in the Italian population sample to be 4.9%. Among gender and the IrisPlex SNPs, gender ranked as the second most important predictor of human eye colour variation in Italians after HERC2 rs12913832. We, furthermore, tested the five lower ranked IrisPlex predictors, and evaluated all possible 3(6) (729) genotype combinations of the IrisPlex assay and their corresponding predictive values using the IrisPlex prediction model [4]. The results suggested that maximum three (rs12913832, rs1800407, rs16891982) of the six IrisPlex SNPs are useful in practical

  10. IS (Iris Security)

    OpenAIRE

    Iovane, G.; Tortoriello, F. S.

    2003-01-01

    In the paper will be presented a safety system based on iridology. The results suggest a new scenario where the security problem in supervised and unsupervised areas can be treat with the present system and the iris image recognition.

  11. PROPERTIES AND MODELING OF UNRESOLVED FINE STRUCTURE LOOPS OBSERVED IN THE SOLAR TRANSITION REGION BY IRIS

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, David H. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Reep, Jeffrey W.; Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2016-08-01

    Recent observations from the Interface Region Imaging Spectrograph ( IRIS ) have discovered a new class of numerous low-lying dynamic loop structures, and it has been argued that they are the long-postulated unresolved fine structures (UFSs) that dominate the emission of the solar transition region. In this letter, we combine IRIS measurements of the properties of a sample of 108 UFSs (intensities, lengths, widths, lifetimes) with one-dimensional non-equilibrium ionization simulations, using the HYDRAD hydrodynamic model to examine whether the UFSs are now truly spatially resolved in the sense of being individual structures rather than being composed of multiple magnetic threads. We find that a simulation of an impulsively heated single strand can reproduce most of the observed properties, suggesting that the UFSs may be resolved, and the distribution of UFS widths implies that they are structured on a spatial scale of 133 km on average. Spatial scales of a few hundred kilometers appear to be typical for a range of chromospheric and coronal structures, and we conjecture that this could be an important clue for understanding the coronal heating process.

  12. Iris-based medical analysis by geometric deformation features.

    Science.gov (United States)

    Ma, Lin; Zhang, D; Li, Naimin; Cai, Yan; Zuo, Wangmeng; Wang, Kuanguan

    2013-01-01

    Iris analysis studies the relationship between human health and changes in the anatomy of the iris. Apart from the fact that iris recognition focuses on modeling the overall structure of the iris, iris diagnosis emphasizes the detecting and analyzing of local variations in the characteristics of irises. This paper focuses on studying the geometrical structure changes in irises that are caused by gastrointestinal diseases, and on measuring the observable deformations in the geometrical structures of irises that are related to roundness, diameter and other geometric forms of the pupil and the collarette. Pupil and collarette based features are defined and extracted. A series of experiments are implemented on our experimental pathological iris database, including manual clustering of both normal and pathological iris images, manual classification by non-specialists, manual classification by individuals with a medical background, classification ability verification for the proposed features, and disease recognition by applying the proposed features. The results prove the effectiveness and clinical diagnostic significance of the proposed features and a reliable recognition performance for automatic disease diagnosis. Our research results offer a novel systematic perspective for iridology studies and promote the progress of both theoretical and practical work in iris diagnosis.

  13. Unconstrained Iris Acquisition and Recognition Using COTS PTZ Camera

    Directory of Open Access Journals (Sweden)

    Venugopalan Shreyas

    2010-01-01

    Full Text Available Abstract Uniqueness of iris patterns among individuals has resulted in the ubiquity of iris recognition systems in virtual and physical spaces, at high security facilities around the globe. Traditional methods of acquiring iris patterns in commercial systems scan the iris when an individual is at a predetermined location in front of the scanner. Most state-of-the-art techniques for unconstrained iris acquisition in literature use expensive custom equipment and are composed of a multicamera setup, which is bulky, expensive, and requires calibration. This paper investigates a method of unconstrained iris acquisition and recognition using a single commercial off-the-shelf (COTS pan-tilt-zoom (PTZ camera, that is compact and that reduces the cost of the final system, compared to other proposed hierarchical multicomponent systems. We employ state-of-the-art techniques for face detection and a robust eye detection scheme using active shape models for accurate landmark localization. Additionally, our system alleviates the need for any calibration stage prior to its use. We present results using a database of iris images captured using our system, while operating in an unconstrained acquisition mode at 1.5 m standoff, yielding an iris diameter in the 150–200 pixels range.

  14. A new objective criterion for IRIS localization

    International Nuclear Information System (INIS)

    Basit, A.

    2010-01-01

    Iris localization is the most important step in iris recognition systems. For commonly used databases, exact data is not given which describe the true results of localization. To cope with this problem a new objective criterion for iris localization is proposed in this paper based on our visual system. A specific number of points are selected on pupil boundary, iris boundary, upper eyelid and lower eyelid using the original image and then distance from these points to the result of complete iris localization has been calculated. If the determined distance is below a certain threshold then iris localization is considered correct. Experimental results show that proposed criterion is very effective. (author)

  15. Iris Template Protection Based on Local Ranking

    Directory of Open Access Journals (Sweden)

    Dongdong Zhao

    2018-01-01

    Full Text Available Biometrics have been widely studied in recent years, and they are increasingly employed in real-world applications. Meanwhile, a number of potential threats to the privacy of biometric data arise. Iris template protection demands that the privacy of iris data should be protected when performing iris recognition. According to the international standard ISO/IEC 24745, iris template protection should satisfy the irreversibility, revocability, and unlinkability. However, existing works about iris template protection demonstrate that it is difficult to satisfy the three privacy requirements simultaneously while supporting effective iris recognition. In this paper, we propose an iris template protection method based on local ranking. Specifically, the iris data are first XORed (Exclusive OR operation with an application-specific string; next, we divide the results into blocks and then partition the blocks into groups. The blocks in each group are ranked according to their decimal values, and original blocks are transformed to their rank values for storage. We also extend the basic method to support the shifting strategy and masking strategy, which are two important strategies for iris recognition. We demonstrate that the proposed method satisfies the irreversibility, revocability, and unlinkability. Experimental results on typical iris datasets (i.e., CASIA-IrisV3-Interval, CASIA-IrisV4-Lamp, UBIRIS-V1-S1, and MMU-V1 show that the proposed method could maintain the recognition performance while protecting the privacy of iris data.

  16. Feature and score fusion based multiple classifier selection for iris recognition.

    Science.gov (United States)

    Islam, Md Rabiul

    2014-01-01

    The aim of this work is to propose a new feature and score fusion based iris recognition approach where voting method on Multiple Classifier Selection technique has been applied. Four Discrete Hidden Markov Model classifiers output, that is, left iris based unimodal system, right iris based unimodal system, left-right iris feature fusion based multimodal system, and left-right iris likelihood ratio score fusion based multimodal system, is combined using voting method to achieve the final recognition result. CASIA-IrisV4 database has been used to measure the performance of the proposed system with various dimensions. Experimental results show the versatility of the proposed system of four different classifiers with various dimensions. Finally, recognition accuracy of the proposed system has been compared with existing N hamming distance score fusion approach proposed by Ma et al., log-likelihood ratio score fusion approach proposed by Schmid et al., and single level feature fusion approach proposed by Hollingsworth et al.

  17. Safety design features of the IRIS

    International Nuclear Information System (INIS)

    2009-01-01

    The International Reactor Innovative and Secure (IRIS) is an advanced, integral, light water cooled reactor of medium generating capacity (335 MW(e)), that features an integral reactor vessel containing all the reactor primary system components, including steam generators, coolant pumps, pressurizer and heaters, and control rod drive mechanisms; in addition to the typical core, internals, control rods and neutron reflector. This integral configuration allows for the use of a small, high design pressure, spherical steel containment which results in a significant reduction in the size of the nuclear island. Other IRIS innovations include a simplified passive safety system concept and equipment features that derive from the 'safety-by-design' philosophy. This design approach allows for elimination of certain accident initiators at the design stage, or when outright elimination is not possible, decreases accident consequences and/or their probability of occurrence. Major design characteristics of the IRIS are given. As part of the IRIS pre-application licensing review by the U.S. Nuclear Regulatory Commission (NRC), the IRIS design team has developed a test plan that will provide the necessary data for safety analysis computer model verification, as well as for verifying the manufacturing feasibility, operability, and durability of new component designs

  18. The bottomside parameters B0, B1 obtained from incoherent scatter measurements during a solar maximum and their comparisons with the IRI-2001 model

    Directory of Open Access Journals (Sweden)

    N. K. Sethi

    2002-06-01

    Full Text Available High resolution electron density profiles (Ne measured with the Arecibo (18.4 N, 66.7 W, Incoherent Scatter radar (I. S. are used to obtain the bottomside shape parameters B0, B1 for a solar maximum period (1989–90. Median values of these parameters are compared with those obtained from the IRI-2001 model. It is observed that during summer, the IRI values agree fairly well with the Arecibo values, though the numbers are somewhat larger during the daytime. Discrepancies occur during winter and equinox, when the IRI underestimates B0 for the local times from about 12:00 LT to about 20:00 LT. Furthermore, the IRI model tends to generally overestimate B1 at all local times. At Arecibo, B0 increases by about 50%, and B1 decreases by about 30% from solar minimum to solar maximum.Key words. Ionosphere (equational ionosphere; modeling and forecasting

  19. What Genes Tell about Iris Appearance

    DEFF Research Database (Denmark)

    Harder, Stine; Christoffersen, Susanne R.; Johansen, Peter

    2012-01-01

    Predicting phenotypes based on genotypes is generally hard, but has shown good results for prediction of iris color. We propose to correlate the appearance of iris with DNA. Six single-nucleotide polymorphisms (SNPs) have previously been shown to correlate with human iris color, and we demonstrat...

  20. Investigation of the single layer model of GPS ionospheric data processing using IRI-90 and the attached diffusive equilibrium model of plasmaspheric electron density

    Directory of Open Access Journals (Sweden)

    L. Bànyai

    1997-06-01

    Full Text Available The single layer model of GPS ionospheric data processing is compared with the International Reference Ionosphere í 1990 and the attached Diffusive Equilibrium model of Plasmasphere (IRI-90+DEP which proved to be a good supplement to GPS data processing. These models can be used to estimate the single layer height and to improve the mapping function in day-time. The code delays estimated from IRI-90+DEP models are compared with GPS measurements carried out by TurboRogue receiver. These models can be used to estimate the preliminary receiver biases especially in the case of cross-correlation tracking mode. The practical drawback of the IRI-90 model is the sharp discontinuity of the ion components during sunset and sunrise at an elevation of 1000 km, because it also causes a sharp discontinuity in the TEC values computed from the DEP model. The GPS data may be a good source to improve the topside region of the IRI model estimating smooth TEC transition before and after sunrise in the plasmasphere.

  1. Does Iris Change Over Time?

    Science.gov (United States)

    Mehrotra, Hunny; Vatsa, Mayank; Singh, Richa; Majhi, Banshidhar

    2013-01-01

    Iris as a biometric identifier is assumed to be stable over a period of time. However, some researchers have observed that for long time lapse, the genuine match score distribution shifts towards the impostor score distribution and the performance of iris recognition reduces. The main purpose of this study is to determine if the shift in genuine scores can be attributed to aging or not. The experiments are performed on the two publicly available iris aging databases namely, ND-Iris-Template-Aging-2008–2010 and ND-TimeLapseIris-2012 using a commercial matcher, VeriEye. While existing results are correct about increase in false rejection over time, we observe that it is primarily due to the presence of other covariates such as blur, noise, occlusion, and pupil dilation. This claim is substantiated with quality score comparison of the gallery and probe pairs. PMID:24244305

  2. Does iris change over time?

    Science.gov (United States)

    Mehrotra, Hunny; Vatsa, Mayank; Singh, Richa; Majhi, Banshidhar

    2013-01-01

    Iris as a biometric identifier is assumed to be stable over a period of time. However, some researchers have observed that for long time lapse, the genuine match score distribution shifts towards the impostor score distribution and the performance of iris recognition reduces. The main purpose of this study is to determine if the shift in genuine scores can be attributed to aging or not. The experiments are performed on the two publicly available iris aging databases namely, ND-Iris-Template-Aging-2008-2010 and ND-TimeLapseIris-2012 using a commercial matcher, VeriEye. While existing results are correct about increase in false rejection over time, we observe that it is primarily due to the presence of other covariates such as blur, noise, occlusion, and pupil dilation. This claim is substantiated with quality score comparison of the gallery and probe pairs.

  3. Does iris change over time?

    Directory of Open Access Journals (Sweden)

    Hunny Mehrotra

    Full Text Available Iris as a biometric identifier is assumed to be stable over a period of time. However, some researchers have observed that for long time lapse, the genuine match score distribution shifts towards the impostor score distribution and the performance of iris recognition reduces. The main purpose of this study is to determine if the shift in genuine scores can be attributed to aging or not. The experiments are performed on the two publicly available iris aging databases namely, ND-Iris-Template-Aging-2008-2010 and ND-TimeLapseIris-2012 using a commercial matcher, VeriEye. While existing results are correct about increase in false rejection over time, we observe that it is primarily due to the presence of other covariates such as blur, noise, occlusion, and pupil dilation. This claim is substantiated with quality score comparison of the gallery and probe pairs.

  4. Iris melanocytoma.

    Science.gov (United States)

    Radovanović, Anica Bobić; Krnjaja, Bojana Dacić; Jaksić, Vesna

    2016-01-01

    Iris melanocytoma (IM) is a rare benign tumor, but unavoidable in differential diagnosis of pigmented iris lesions. According to the best knowledge of the authors it is for the first time in Serbia that a well-documented case of IM is presented and that the problem of this tumor is discussed. In the left eye of a 47-year-old white female at the iris in a six o'clock position, a highly pigmented, dome shaped lesion with a crater-like cavity in the center and with feathery margins was noticed. There were no signs of infiltration of surrounding tissue or intrinsic vessels and the lens was clear. Visual acuity and intraocular pressure were normal. An ultrasound biomicroscopy (UBM) revealed a well-defined lesion with high internal reflectivity, with a base diameter of 1.25 mm and a thickness of 0.80 mm in the periphery, and 0.53 mm in the central part.The diagnosis of IM of the left eye was established and regular checkups were performed for ten years. No changes in clinical or UBM presentation were established. Awareness of clinical presentation of IM is most important for correct diagnosis. Ultrasound biomicroscopy is a useful diagnostic procedure in the following up of IM.

  5. A comparison of neural network-based predictions of foF2 with the IRI-2012 model at conjugate points in Southeast Asia

    Science.gov (United States)

    Wichaipanich, Noraset; Hozumi, Kornyanat; Supnithi, Pornchai; Tsugawa, Takuya

    2017-06-01

    This paper presents the development of Neural Network (NN) model for the prediction of the F2 layer critical frequency (foF2) at three ionosonde stations near the magnetic equator of Southeast Asia. Two of these stations including Chiang Mai (18.76°N, 98.93°E, dip angle 12.7°N) and Kototabang (0.2°S, 100.3°E, dip angle 10.1°S) are at the conjugate points while Chumphon (10.72°N, 99.37°E, dip angle 3.0°N) station is near the equator. To produce the model, the feed forward network with backpropagation algorithm is applied. The NN is trained with the daily hourly values of foF2 during 2004-2012, except 2009, and the selected input parameters, which affect the foF2 variability, include day number (DN), hour number (HR), solar zenith angle (C), geographic latitude (θ), magnetic inclination (I), magnetic declination (D) and angle of meridian (M) relative to the sub-solar point, the 7-day mean of F10.7 (F10.7_7), the 81-day mean of SSN (SSN_81) and the 2-day mean of Ap (Ap_2). The foF2 data of 2009 and 2013 are then used for testing the NN model during the foF2 interpolation and extrapolation, respectively. To examine the performance of the proposed NN, the root mean square error (RMSE) of the observed foF2, the proposed NN model and the IRI-2012 (CCIR and URSI options) model are compared. In general, the results show the same trends in foF2 variation between the models (NN and IRI-2012) and the observations in that they are higher during the day and lower at night. Besides, the results demonstrate that the proposed NN model can predict the foF2 values more closely during daytime than during nighttime as supported by the lower RMSE values during daytime (0.5 ≤ RMSE ≤ 1.0 for Chumphon and Kototabang, 0.7 ≤ RMSE ≤ 1.2 at Chiang Mai) and with the highest levels during nighttime (0.8 ≤ RMSE ≤ 1.5 for Chumphon and Kototabang, 1.2 ≤ RMSE ≤ 2.0 at Chiang Mai). Furthermore, the NN model predicts the foF2 values more accurately than the IRI model at the

  6. Iris recognition and what is next? Iris diagnosis: a new challenging topic for machine vision from image acquisition to image interpretation

    Science.gov (United States)

    Perner, Petra

    2017-03-01

    Molecular image-based techniques are widely used in medicine to detect specific diseases. Look diagnosis is an important issue but also the analysis of the eye plays an important role in order to detect specific diseases. These topics are important topics in medicine and the standardization of these topics by an automatic system can be a new challenging field for machine vision. Compared to iris recognition has the iris diagnosis much more higher demands for the image acquisition and interpretation of the iris. One understands by iris diagnosis (Iridology) the investigation and analysis of the colored part of the eye, the iris, to discover factors, which play an important role for the prevention and treatment of illnesses, but also for the preservation of an optimum health. An automatic system would pave the way for a much wider use of the iris diagnosis for the diagnosis of illnesses and for the purpose of individual health protection. With this paper, we describe our work towards an automatic iris diagnosis system. We describe the image acquisition and the problems with it. Different ways are explained for image acquisition and image preprocessing. We describe the image analysis method for the detection of the iris. The meta-model for image interpretation is given. Based on this model we show the many tasks for image analysis that range from different image-object feature analysis, spatial image analysis to color image analysis. Our first results for the recognition of the iris are given. We describe how detecting the pupil and not wanted lamp spots. We explain how to recognize orange blue spots in the iris and match them against the topological map of the iris. Finally, we give an outlook for further work.

  7. Hyperspectral versus multispectral crop-productivity modeling and type discrimination for the HyspIRI mission

    Science.gov (United States)

    Mariotto, Isabella; Thenkabail, Prasad S.; Huete, Alfredo; Slonecker, E. Terrence; Platonov, Alexander

    2013-01-01

    Precise monitoring of agricultural crop biomass and yield quantities is critical for crop production management and prediction. The goal of this study was to compare hyperspectral narrowband (HNB) versus multispectral broadband (MBB) reflectance data in studying irrigated cropland characteristics of five leading world crops (cotton, wheat, maize, rice, and alfalfa) with the objectives of: 1. Modeling crop productivity, and 2. Discriminating crop types. HNB data were obtained from Hyperion hyperspectral imager and field ASD spectroradiometer, and MBB data were obtained from five broadband sensors: Landsat-7 Enhanced Thematic Mapper Plus (ETM +), Advanced Land Imager (ALI), Indian Remote Sensing (IRS), IKONOS, and QuickBird. A large collection of field spectral and biophysical variables were gathered for the 5 crops in Central Asia throughout the growing seasons of 2006 and 2007. Overall, the HNB and hyperspectral vegetation index (HVI) crop biophysical models explained about 25% greater variability when compared with corresponding MBB models. Typically, 3 to 7 HNBs, in multiple linear regression models of a given crop variable, explained more than 93% of variability in crop models. The evaluation of λ1 (400–2500 nm) versus λ2 (400–2500 nm) plots of various crop biophysical variables showed that the best two-band normalized difference HVIs involved HNBs centered at: (i) 742 nm and 1175 nm (HVI742-1175), (ii) 1296 nm and 1054 nm (HVI1296-1054), (iii) 1225 nm and 697 nm (HVI1225-697), and (iv) 702 nm and 1104 nm (HVI702-1104). Among the most frequently occurring HNBs in various crop biophysical models, 74% were located in the 1051–2331 nm spectral range, followed by 10% in the moisture sensitive 970 nm, 6% in the red and red-edge (630–752 nm), and the remaining 10% distributed between blue (400–500 nm), green (501–600 nm), and NIR (760–900 nm).Discriminant models, used for discriminating 3 or 4 or 5 crop types, showed

  8. Comparison of GPS-TEC measurements with NeQuick2 and IRI model predictions in the low latitude East African region during varying solar activity period (1998 and 2008-2015)

    Science.gov (United States)

    Mengistu, E.; Damtie, B.; Moldwin, M. B.; Nigussie, M.

    2018-03-01

    This paper examines the performances of NeQuick2, the latest available IRI-2016, IRI-2012 and IRI-2007 models in describing the monthly and seasonal mean total electron content (TEC) over the East African region. This is to gain insight into the success of the various model types and versions at characterizing the ionosphere within the equatorial ionization anomaly. TEC derived from five Global Positioning System (GPS) receivers installed at Addis Ababa (ADD, 5.33°N, 111.99°E Geog.), Asab (ASAB, 8.67°N, 116.44°E Geog.), Ambo (ABOO, 5.43°N, 111.05°E Geog.), Nairobi (RCMN, -4.48°N, 108.46°E Geog.) and Nazret (NAZR, 4.78°N, 112.43°E Geog.), are compared with the corresponding values computed using those models during varying solar activity period (1998 and 2008-2015). We found that different models describe the equatorial and anomaly region ionosphere best depending on solar cycle, season and geomagnetic activity levels. Our results show that IRI-2016 is the best model (compared to others in terms of discrepancy range) in estimating the monthly mean GPS-TEC at NAZR, ADD and RCMN stations except at ADD during 2008 and 2012. It is also found that IRI-2012 is the best model in estimating the monthly mean TEC at ABOO station in 2014. IRI show better agreement with observations during June solstice for all the years studied at ADD except in 2012 where NeQuick2 better performs. At NAZR, NeQuick2 better performs in estimating seasonal mean GPS-TEC during 2011, while IRI models are best during 2008-2009. Both NeQuick2 and IRI models underestimate measured TEC for all the seasons at ADD in 2010 but overestimate at NAZR in 2009 and RCMN in 2008. The periodic variations of experimental and modeled TEC have been compared with solar and geomagnetic indices at ABOO and ASAB in 2014 and results indicate that the F10.7 and sunspot number as indices of solar activity seriously affects the TEC variations with periods of 16-32 days followed by the geomagnetic activity on

  9. Iris recognition using possibilistic fuzzy matching on local features.

    Science.gov (United States)

    Tsai, Chung-Chih; Lin, Heng-Yi; Taur, Jinshiuh; Tao, Chin-Wang

    2012-02-01

    In this paper, we propose a novel possibilistic fuzzy matching strategy with invariant properties, which can provide a robust and effective matching scheme for two sets of iris feature points. In addition, the nonlinear normalization model is adopted to provide more accurate position before matching. Moreover, an effective iris segmentation method is proposed to refine the detected inner and outer boundaries to smooth curves. For feature extraction, the Gabor filters are adopted to detect the local feature points from the segmented iris image in the Cartesian coordinate system and to generate a rotation-invariant descriptor for each detected point. After that, the proposed matching algorithm is used to compute a similarity score for two sets of feature points from a pair of iris images. The experimental results show that the performance of our system is better than those of the systems based on the local features and is comparable to those of the typical systems.

  10. Gender is a major factor explaining discrepancies in eye colour prediction based on HERC2/OCA2 genotype and the IrisPlex model.

    Science.gov (United States)

    Martinez-Cadenas, Conrado; Peña-Chilet, Maria; Ibarrola-Villava, Maider; Ribas, Gloria

    2013-07-01

    In recent years, several studies have greatly increased our understanding of the genetic basis underlying human eye colour variation. A large percentage of the eye colour diversity present in humans can already be genetically explained, so much so that different DNA-based eye colour prediction models, such as IrisPlex, have been recently developed for forensic purposes. Though these models are already highly accurate, they are by no means perfect, with many genotype-phenotype discrepancies still remaining unresolved. In this work we have genotyped six SNPs associated with eye colour (IrisPlex) in 535 individuals from Spain, a Mediterranean population. Aside from different SNP frequencies in Spain compared to Northern Europe, the results for eye colour prediction are quite similar to other studies. However, we have found an association between gender and eye colour prediction. When comparing similar eye colour genetic profiles, females tend, as a whole, to have darker eyes than males (and, conversely, males lighter than females). These results are also corroborated by the revision and meta-analysis of data from previously published eye colour genetic studies in several Caucasian populations, which significantly support the fact that males are more likely to have blue eyes than females, while females tend to show higher frequencies of green and brown eyes than males. This significant gender difference would suggest that there is an as yet unidentified gender-related factor contributing to human eye colour variation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Engineering a Light-Attenuating Artificial Iris.

    Science.gov (United States)

    Shareef, Farah J; Sun, Shan; Kotecha, Mrignayani; Kassem, Iris; Azar, Dimitri; Cho, Michael

    2016-04-01

    Discomfort from light exposure leads to photophobia, glare, and poor vision in patients with congenital or trauma-induced iris damage. Commercial artificial iris lenses are static in nature to provide aesthetics without restoring the natural iris's dynamic response to light. A new photo-responsive artificial iris was therefore developed using a photochromic material with self-adaptive light transmission properties and encased in a transparent biocompatible polymer matrix. The implantable artificial iris was designed and engineered using Photopia, a class of photo-responsive materials (termed naphthopyrans) embedded in polyethylene. Photopia was reshaped into annular disks that were spin-coated with polydimethylsiloxane (PDMS) to form our artificial iris lens of controlled thickness. Activated by UV and blue light in approximately 5 seconds with complete reversal in less than 1 minute, the artificial iris demonstrates graded attenuation of up to 40% of visible and 60% of UV light. There optical characteristics are suitable to reversibly regulate the incident light intensity. In vitro cell culture experiments showed up to 60% cell death within 10 days of exposure to Photopia, but no significant cell death observed when cultured with the artificial iris with protective encapsulation. Nuclear magnetic resonance spectroscopy confirmed these results as there was no apparent leakage of potentially toxic photochromic material from the ophthalmic device. Our artificial iris lens mimics the functionality of the natural iris by attenuating light intensity entering the eye with its rapid reversible change in opacity and thus potentially providing an improved treatment option for patients with iris damage.

  12. Fluid and structure coupling analysis of the interaction between aqueous humor and iris.

    Science.gov (United States)

    Wang, Wenjia; Qian, Xiuqing; Song, Hongfang; Zhang, Mindi; Liu, Zhicheng

    2016-12-28

    Glaucoma is the primary cause of irreversible blindness worldwide associated with high intraocular pressure (IOP). Elevated intraocular pressure will affect the normal aqueous humor outflow, resulting in deformation of iris. However, the deformation ability of iris is closely related to its material properties. Meanwhile, the passive deformation of the iris aggravates the pupillary block and angle closure. The nature of the interaction mechanism of iris deformation and aqueous humor fluid flow has not been fully understood and has been somewhat a controversial issue. The purpose here was to study the effect of IOP, localization, and temperature on the flow of the aqueous humor and the deformation of iris interacted by aqueous humor fluid flow. Based on mechanisms of aqueous physiology and fluid dynamics, 3D model of anterior chamber (AC) was constructed with the human anatomical parameters as a reference. A 3D idealized standard geometry of anterior segment of human eye was performed. Enlarge the size of the idealization geometry model 5 times to create a simulation device by using 3D printing technology. In this paper, particle image velocimetry technology is applied to measure the characteristic of fluid outflow in different inlet velocity based on the device. Numerically calculations were made by using ANSYS 14.0 Finite Element Analysis. Compare of the velocity distributions to confirm the validity of the model. The fluid structure interaction (FSI) analysis was carried out in the valid geometry model to study the aqueous flow and iris change. In this paper, the validity of the model is verified through computation and comparison. The results indicated that changes of gravity direction of model significantly affected the fluid dynamics parameters and the temperature distribution in anterior chamber. Increased pressure and the vertical position increase the velocity of the aqueous humor fluid flow, with the value increased of 0.015 and 0.035 mm/s. The results

  13. Genetic Background of Iris Melanomas and Iris Melanocytic Tumors of Uncertain Malignant Potential.

    Science.gov (United States)

    van Poppelen, Natasha M; Vaarwater, Jolanda; Mudhar, Hardeep S; Sisley, Karen; Rennie, Ian G; Rundle, Paul; Brands, Tom; van den Bosch, Quincy C C; Mensink, Hanneke W; de Klein, Annelies; Kiliç, Emine; Verdijk, Robert M

    2018-01-19

    Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Iris melanoma comprises 4% to 10% of all UMs and has a lower mortality rate. The genetic changes in iris melanoma are not as well characterized as ciliary body or choroidal melanoma. The aim of this study was to gain more insight into the genetic background of iris melanoma and iris nevi. Multicenter, retrospective case series. Patients diagnosed with iris melanoma or iris nevi who underwent surgical intervention as primary or secondary treatment. Next-generation sequencing of GNAQ, GNA11, EIF1AX, SF3B1, BAP1, NRAS, BRAF, PTEN, c-Kit, TP53, and TERT was performed on 30 iris melanomas and 7 iris nevi. Copy number status was detected using single nucleotide polymorphisms (SNPs) included in the next-generation sequencing (NGS) panel, SNP array, or fluorescent in situ hybridization. BAP1 immunohistochemistry was performed on all samples. Mutation and copy number status were analyzed. Results of BAP1 immunohistochemistry were used for survival analysis. In 26 of the 30 iris melanoma and all iris nevi, at least 1 mutation was identified. Multiple mutations were detected in 23 iris melanoma and 5 nevi, as well as mutations in GNAQ and GNA11. Furthermore, 13 of 30 BAP1, 5 of 30 EIF1AX, and 2 of 30 SF3B1 mutations were identified in iris melanoma. No correlation between BAP1 status and disease-free survival was found. The iris nevi showed 1 EIF1AX and 3 BAP1 mutations. Two of the nevi, with a BAP1 mutation, were histologically borderline malignant. Mutations in NRAS, BRAF, PTEN, c-KIT, and TP53 were detected in 6 iris melanomas and 4 iris nevi. Mutations that are often found in uveal and cutaneous melanoma were identified in this cohort of iris melanomas and iris nevi. Therefore, iris melanomas harbor a molecular profile comparable to both choroidal melanoma and cutaneous melanoma. These findings may offer adjuvant targeted therapies for iris melanoma. There was no prognostic significance of

  14. Shape adaptive, robust iris feature extraction from noisy iris images.

    Science.gov (United States)

    Ghodrati, Hamed; Dehghani, Mohammad Javad; Danyali, Habibolah

    2013-10-01

    In the current iris recognition systems, noise removing step is only used to detect noisy parts of the iris region and features extracted from there will be excluded in matching step. Whereas depending on the filter structure used in feature extraction, the noisy parts may influence relevant features. To the best of our knowledge, the effect of noise factors on feature extraction has not been considered in the previous works. This paper investigates the effect of shape adaptive wavelet transform and shape adaptive Gabor-wavelet for feature extraction on the iris recognition performance. In addition, an effective noise-removing approach is proposed in this paper. The contribution is to detect eyelashes and reflections by calculating appropriate thresholds by a procedure called statistical decision making. The eyelids are segmented by parabolic Hough transform in normalized iris image to decrease computational burden through omitting rotation term. The iris is localized by an accurate and fast algorithm based on coarse-to-fine strategy. The principle of mask code generation is to assign the noisy bits in an iris code in order to exclude them in matching step is presented in details. An experimental result shows that by using the shape adaptive Gabor-wavelet technique there is an improvement on the accuracy of recognition rate.

  15. ANTIMICROBIAL ACTIVITY OF EXTRACTS OF IRIS HUNGARICA AND IRIS SIBIRICA

    Directory of Open Access Journals (Sweden)

    Kovalev V. M.

    2017-06-01

    following test-strains were used: Staphylococcus aureus АТСС 25923, Escherichia coli АТСС 25922, Pseudomonas aeruginosa АТСС 27853, Bacillus subtilis АТСС 6633, Proteus vulgaris ATCC 4636, Candida albicans АТСС 885/653. The 18 to 24–hour culture of microorganisms was used for the test. Mueller-Hinton agar was used for bacteria. The strains of Candida albicans were cultivated using Sabouraud agar. Method of serial dilutions was used for the examination of antibacterial properties of selected extracts. The concentration of substances was 1 1000 μg/ml; 2 500 μg/ml; 3 250 μg/ml; 4 125 μg/ml; 5 62.5 μg/ml. To each test tube was added of 0.1 ml 109 microbial cells test strains. Examined preparations represented the alcohol and aqueous solutions of the dry and lipophilic extracts of Irises in the different concentrations. Water is the solvent for the dry extracts of Iris hungarica, for the lipophilic – is 70% ethyl alcohol. For dissolution of the dry extracts of Iris sibirica was used water, 70% and 96% ethyl alcohol, for lipophilic extracts – was used 70%, 96% ethyl alcohol. The concentration of the substances was 1.0 % in all experiments. In the capacity of the comparative drug was selected an alcohol solution of chlorophyllipt in the dose of 10 μg/ml («Chlorophyllipt alcohol solution 1%» 100 ml, «GNCLS» Pilot Plant. Results and discussions. The dry extract of the leaves of Iris hungarica at the concentration 1% has a more pronounced antibacterial activity than the extract of the rhizomes and is the most susceptible to gram-negative bacteria – Escherichiа coli, Proteus vulgaris, Pseudomonas aeruginosa. At that time, as the dry extract of the rhizomes of Iris hungarica at the concentration 1% is more susceptible to gram-positive bacteria. The lipophilic extracts of the leaves and rhizomes were more susceptibility to gram-positive bacteria. The dry extracts of the leaves and rhizomes of Iris sibirica in aqueous and alcohol solutions have a

  16. Risk-informed design of IRIS using a level-1 probabilistic risk assessment from its conceptual design phase

    International Nuclear Information System (INIS)

    Mizuno, Yuko; Ninokata, Hisashi; Finnicum, David J.

    2005-01-01

    In this study, a probabilistic risk assessment (PRA) for the International Reactor Innovative and Secure (IRIS) has been generated to address two key areas as a part of the effort for the pre-application licensing of the IRIS design. First, the IRIS PRA is supporting the evaluation of IRIS design by providing design insights as well as a solid risk basis for the pre-licensing evaluation of the IRIS design. Second, the current PRA task is beginning the preparation of the more complete PRA analyses and documentation that will be required for Design Certification. The initial IRIS PRA is an at-power, Level-1 PRA for internal events that focuses on the evaluation of the IRIS design features to support the risk-informed design of IRIS by application of the PRA insights and the risk information to the design. To accomplish the evaluation, a reasonably complete Level-1 PRA model has been developed. The use of PRA in the early stages of the design has allowed a selection of design and performance features and an optimization of the design of several systems to reduce the potential for events that could lead to core damage via both enhanced prevention and mitigation of challenges. As a result, the total core damage frequency for internal events for the IRIS design has been calculated as 1.2x10 -8 per year

  17. Improving Robustness Assessment Methodologies for Structures Impacted by Missiles (IRIS-2012) - Final Report

    International Nuclear Information System (INIS)

    Orbovic, Neb; Blahoainu, Andrei; Sagals, Genadis; Tarallo, Francois; Rambach, Jean-Mathieu; Huerta, Alejandro; White, Andrew; Nevander, Olli; ); Riera, Jorge Daniel; Krauthammer, Ted; Krutzik, Norbert; Arros, Jorma; Rouqand, Alain; Stangenberg, Friedhelm; Schwer, Leonard E.

    2014-01-01

    This report documents the results and conclusions of the second phase of the Integrity and Ageing of Components and Structures Working Group (WGIAGE) activity 'Improving Robustness assessment of structures Impacted by missiles', called IRIS-2012. The objective of the activity was to conduct a post-test benchmark study to improve models and evaluation techniques used in IRIS-2010. The benchmark was open to the new participants and some of IRIS-2010 participants did not take part of IRIS-2012. For this reason the team numbers in two benchmarks are different and to make direct comparisons it is necessary to have both lists. For IRIS-2010 benchmark a series of repeated test was performed: two bending rupture tests and three punching rupture tests. For IRIS-2012 and based on recommendation from IRIS-2010, tri-axial tests and Brazilian tensile test were additionally performed in order to calibrate constitutive models. The benchmark was officially launched in February 2012 with the participation of twenty six teams from twenty different institutions (Safety Authorities, TSOs, Utilities, Vendors, Research Institutes and Consulting Companies), from ten different countries from Europe, North America and Asia (plus 1 international organisation). A three day workshop was convened in October 2012 in Ottawa, Ontario, Canada where each participating team presented and discussed their results and performed simulations. Based on IRIS-2010 results and recommendations, OECD/NEA members recognized that there was a need to continue the work on understanding and improving simulation of structural impact. The goal of the new IRIS-2012 benchmark was to: 1) Update and improve existing FE models, for teams that participated in IRIS-2010, or to create new models for new participants. In order to improve FE models it was requested to: Simulate uni-axial unconfined concrete test and tri-axial concrete tests, using the results provided by IRSN, as well as the Brazilian test (concrete tensile

  18. Enhanced iris recognition method based on multi-unit iris images

    Science.gov (United States)

    Shin, Kwang Yong; Kim, Yeong Gon; Park, Kang Ryoung

    2013-04-01

    For the purpose of biometric person identification, iris recognition uses the unique characteristics of the patterns of the iris; that is, the eye region between the pupil and the sclera. When obtaining an iris image, the iris's image is frequently rotated because of the user's head roll toward the left or right shoulder. As the rotation of the iris image leads to circular shifting of the iris features, the accuracy of iris recognition is degraded. To solve this problem, conventional iris recognition methods use shifting of the iris feature codes to perform the matching. However, this increases the computational complexity and level of false acceptance error. To solve these problems, we propose a novel iris recognition method based on multi-unit iris images. Our method is novel in the following five ways compared with previous methods. First, to detect both eyes, we use Adaboost and a rapid eye detector (RED) based on the iris shape feature and integral imaging. Both eyes are detected using RED in the approximate candidate region that consists of the binocular region, which is determined by the Adaboost detector. Second, we classify the detected eyes into the left and right eyes, because the iris patterns in the left and right eyes in the same person are different, and they are therefore considered as different classes. We can improve the accuracy of iris recognition using this pre-classification of the left and right eyes. Third, by measuring the angle of head roll using the two center positions of the left and right pupils, detected by two circular edge detectors, we obtain the information of the iris rotation angle. Fourth, in order to reduce the error and processing time of iris recognition, adaptive bit-shifting based on the measured iris rotation angle is used in feature matching. Fifth, the recognition accuracy is enhanced by the score fusion of the left and right irises. Experimental results on the iris open database of low-resolution images showed that the

  19. The IRIS user guide

    International Nuclear Information System (INIS)

    Adams, M.; Howells, W.; Telling, M.

    2001-01-01

    The principles of operation of the IRIS instrument based on inelastic neutron scattering and diffraction are described. The procedure of an experiment performance on IRIS consists of selecting sample cans, loading the sample into the neutron beam. Instructions for using the beam line shutter interlock system, IRIS computing procedure, suitable instrument settings and chopper control are included

  20. Iris Recognition: The Consequences of Image Compression

    Directory of Open Access Journals (Sweden)

    Bishop DanielA

    2010-01-01

    Full Text Available Iris recognition for human identification is one of the most accurate biometrics, and its employment is expanding globally. The use of portable iris systems, particularly in law enforcement applications, is growing. In many of these applications, the portable device may be required to transmit an iris image or template over a narrow-bandwidth communication channel. Typically, a full resolution image (e.g., VGA is desired to ensure sufficient pixels across the iris to be confident of accurate recognition results. To minimize the time to transmit a large amount of data over a narrow-bandwidth communication channel, image compression can be used to reduce the file size of the iris image. In other applications, such as the Registered Traveler program, an entire iris image is stored on a smart card, but only 4 kB is allowed for the iris image. For this type of application, image compression is also the solution. This paper investigates the effects of image compression on recognition system performance using a commercial version of the Daugman iris2pi algorithm along with JPEG-2000 compression, and links these to image quality. Using the ICE 2005 iris database, we find that even in the face of significant compression, recognition performance is minimally affected.

  1. Iris Recognition: The Consequences of Image Compression

    Science.gov (United States)

    Ives, Robert W.; Bishop, Daniel A.; Du, Yingzi; Belcher, Craig

    2010-12-01

    Iris recognition for human identification is one of the most accurate biometrics, and its employment is expanding globally. The use of portable iris systems, particularly in law enforcement applications, is growing. In many of these applications, the portable device may be required to transmit an iris image or template over a narrow-bandwidth communication channel. Typically, a full resolution image (e.g., VGA) is desired to ensure sufficient pixels across the iris to be confident of accurate recognition results. To minimize the time to transmit a large amount of data over a narrow-bandwidth communication channel, image compression can be used to reduce the file size of the iris image. In other applications, such as the Registered Traveler program, an entire iris image is stored on a smart card, but only 4 kB is allowed for the iris image. For this type of application, image compression is also the solution. This paper investigates the effects of image compression on recognition system performance using a commercial version of the Daugman iris2pi algorithm along with JPEG-2000 compression, and links these to image quality. Using the ICE 2005 iris database, we find that even in the face of significant compression, recognition performance is minimally affected.

  2. Developmental origin of the posterior pigmented epithelium of iris.

    Science.gov (United States)

    Wang, Xiaobing; Xiong, Kai; Lu, Lei; Gu, Dandan; Wang, Songtao; Chen, Jing; Xiao, Honglei; Zhou, Guomin

    2015-03-01

    Iris epithelium is a double-layered pigmented cuboidal epithelium. According to the current model, the neural retina and the posterior iris pigment epithelium (IPE) are derived from the inner wall of the optic cup, while the retinal pigment epithelium (RPE) and the anterior IPE are derived from the outer wall of the optic cup during development. Our current study shows evidence, contradicting this model of fetal iris development. We demonstrate that human fetal iris expression patterns of Otx2 and Mitf transcription factors are similar, while the expressions of Otx2 and Sox2 are complementary. Furthermore, IPE and RPE exhibit identical morphologic development during the early embryonic period. Our results suggest that the outer layer of the optic cup forms two layers of the iris epithelium, and the posterior IPE is the inward-curling anterior rim of the outer layer of the optic cup. These findings provide a reasonable explanation of how IPE cells can be used as an appropriate substitute for RPE cells.

  3. A fourier transform quality measure for iris images

    CSIR Research Space (South Africa)

    Makinana, S

    2014-08-01

    Full Text Available to ensure that good quality images are selected for feature extraction, in order to improve iris recognition system. In addition, this research proposes a measure of iris image quality using a Fourier Transform. The experimental results demonstrate...

  4. Texture Feature Extraction and Classification for Iris Diagnosis

    Science.gov (United States)

    Ma, Lin; Li, Naimin

    Appling computer aided techniques in iris image processing, and combining occidental iridology with the traditional Chinese medicine is a challenging research area in digital image processing and artificial intelligence. This paper proposes an iridology model that consists the iris image pre-processing, texture feature analysis and disease classification. To the pre-processing, a 2-step iris localization approach is proposed; a 2-D Gabor filter based texture analysis and a texture fractal dimension estimation method are proposed for pathological feature extraction; and at last support vector machines are constructed to recognize 2 typical diseases such as the alimentary canal disease and the nerve system disease. Experimental results show that the proposed iridology diagnosis model is quite effective and promising for medical diagnosis and health surveillance for both hospital and public use.

  5. Modeling the Lower Part of the Topside Ionospheric Vertical Electron Density Profile Over the European Region by Means of Swarm Satellites Data and IRI UP Method

    Science.gov (United States)

    Pignalberi, A.; Pezzopane, M.; Rizzi, R.

    2018-03-01

    An empirical method to model the lower part of the ionospheric topside region from the F2 layer peak height to about 500-600 km of altitude over the European region is proposed. The method is based on electron density values recorded from December 2013 to June 2016 by Swarm satellites and on foF2 and hmF2 values provided by IRI UP (International Reference Ionosphere UPdate), which is a method developed to update the IRI model relying on the assimilation of foF2 and M(3000)F2 data routinely recorded by a network of European ionosonde stations. Topside effective scale heights are calculated by fitting some definite analytical functions (α-Chapman, β-Chapman, Epstein, and exponential) through the values recorded by Swarm and the ones output by IRI UP, with the assumption that the effective scale height is constant in the altitude range considered. Calculated effective scale heights are then modeled as a function of foF2 and hmF2, in order to be operationally applicable to both ionosonde measurements and ionospheric models, like IRI. The method produces two-dimensional grids of the median effective scale height binned as a function of foF2 and hmF2, for each of the considered topside profiles. A statistical comparison with Constellation Observing System for Meteorology, Ionosphere, and Climate/FORMOsa SATellite-3 collected Radio Occultation profiles is carried out to assess the validity of the proposed method and to investigate which of the considered topside profiles is the best one. The α-Chapman topside function displays the best performance compared to the others and also when compared to the NeQuick topside option of IRI.

  6. Equatorial Ionospheric Anomaly (EIA) and comparison with IRI model during descending phase of solar activity (2005-2009)

    Science.gov (United States)

    Kumar, Sanjay; Singh, A. K.; Lee, Jiyun

    2014-03-01

    The ionospheric variability at equatorial and low latitude region is known to be extreme as compared to mid latitude region. In this study the ionospheric total electron content (TEC), is derived by analyzing dual frequency Global Positioning System (GPS) data recorded at two stations separated by 325 km near the Indian equatorial anomaly region, Varanasi (Geog latitude 25°, 16/ N, longitude 82°, 59/ E, Geomagnetic latitude 16°, 08/ N) and Kanpur (Geog latitude 26°, 18/ N, longitude 80°, 12/ E, Geomagnetic latitude 17°, 18/ N). Specifically, we studied monthly, seasonal and annual variations as well as solar and geomagnetic effects on the equatorial ionospheric anomaly (EIA) during the descending phase of solar activity from 2005 to 2009. It is found that the maximum TEC (EIA) near equatorial anomaly crest yield their maximum values during the equinox months and their minimum values during the summer. Using monthly averaged peak magnitude of TEC, a clear semi-annual variation is seen with two maxima occurring in both spring and autumn. Results also showed the presence of winter anomaly or seasonal anomaly in the EIA crest throughout the period 2005-2009 only except during the deep solar minimum year 2007-2008. The correlation analysis indicate that the variation of EIA crest is more affected by solar activity compared to geomagnetic activity with maximum dependence on the solar EUV flux, which is attributed to direct link of EUV flux on the formation of ionosphere and main agent of the ionization. The statistical mean occurrence of EIA crest in TEC during the year from 2005 to 2009 is found to around 12:54 LT hour and at 21.12° N geographic latitude. The crest of EIA shifts towards lower latitudes and the rate of shift of the crest latitude during this period is found to be 0.87° N/per year. The comparison between IRI models with observation during this period has been made and comparison is poor with increasing solar activity with maximum difference during

  7. Engineering a Light-Attenuating Artificial Iris

    Science.gov (United States)

    Shareef, Farah J.; Sun, Shan; Kotecha, Mrignayani; Kassem, Iris; Azar, Dimitri; Cho, Michael

    2016-01-01

    Purpose Discomfort from light exposure leads to photophobia, glare, and poor vision in patients with congenital or trauma-induced iris damage. Commercial artificial iris lenses are static in nature to provide aesthetics without restoring the natural iris's dynamic response to light. A new photo-responsive artificial iris was therefore developed using a photochromic material with self-adaptive light transmission properties and encased in a transparent biocompatible polymer matrix. Methods The implantable artificial iris was designed and engineered using Photopia, a class of photo-responsive materials (termed naphthopyrans) embedded in polyethylene. Photopia was reshaped into annular disks that were spin-coated with polydimethylsiloxane (PDMS) to form our artificial iris lens of controlled thickness. Results Activated by UV and blue light in approximately 5 seconds with complete reversal in less than 1 minute, the artificial iris demonstrates graded attenuation of up to 40% of visible and 60% of UV light. There optical characteristics are suitable to reversibly regulate the incident light intensity. In vitro cell culture experiments showed up to 60% cell death within 10 days of exposure to Photopia, but no significant cell death observed when cultured with the artificial iris with protective encapsulation. Nuclear magnetic resonance spectroscopy confirmed these results as there was no apparent leakage of potentially toxic photochromic material from the ophthalmic device. Conclusions Our artificial iris lens mimics the functionality of the natural iris by attenuating light intensity entering the eye with its rapid reversible change in opacity and thus potentially providing an improved treatment option for patients with iris damage. PMID:27116547

  8. A Study on Iris Localization and Recognition on Mobile Phones

    Directory of Open Access Journals (Sweden)

    Dae Sik Jeong

    2007-11-01

    Full Text Available A new iris recognition method for mobile phones based on corneal specular reflections (SRs is discussed. We present the following three novelties over previous research. First, in case of user with glasses, many noncorneal SRs may happen on the surface of glasses and it is very difficult to detect genuine SR on the cornea. To overcome such problems, we propose a successive on/off dual illuminator scheme to detect genuine SRs on the corneas of users with glasses. Second, to detect SRs robustly, we estimated the size, shape, and brightness of the SRs based on eye, camera, and illuminator models. Third, the detected eye (iris region was verified again using the AdaBoost eye detector. Experimental results with 400 face images captured from 100 persons with a mobile phone camera showed that the rate of correct iris detection was 99.5% (for images without glasses and 98.9% (for images with glasses or contact lenses. The consequent accuracy of iris authentication was 0.05% of the EER (equal error rate based on detected iris images.

  9. [Surgical treatment with an artificial iris].

    Science.gov (United States)

    Mayer, C S; Hoffmann, A E

    2015-10-01

    Iris defects with their disturbed pupillary function, visual impairment and glare constitute a therapeutic challenge in surgical reconstruction. A new therapeutic option for distinctive defects consists in the implantation of a custom-made silicone iris. This new and challenging therapy provides the opportunity to achieve an individual, aesthetically appealing and good functional result for the patient.

  10. Iris Cryptography for Security Purpose

    Science.gov (United States)

    Ajith, Srighakollapu; Balaji Ganesh Kumar, M.; Latha, S.; Samiappan, Dhanalakshmi; Muthu, P.

    2018-04-01

    In today's world, the security became the major issue to every human being. A major issue is hacking as hackers are everywhere, as the technology was developed still there are many issues where the technology fails to meet the security. Engineers, scientists were discovering the new products for security purpose as biometrics sensors like face recognition, pattern recognition, gesture recognition, voice authentication etcetera. But these devices fail to reach the expected results. In this work, we are going to present an approach to generate a unique secure key using the iris template. Here the iris templates are processed using the well-defined processing techniques. Using the encryption and decryption process they are stored, traversed and utilized. As of the work, we can conclude that the iris cryptography gives us the expected results for securing the data from eavesdroppers.

  11. Automatic quantification of iris color

    DEFF Research Database (Denmark)

    Christoffersen, S.; Harder, Stine; Andersen, J. D.

    2012-01-01

    regions. The result is a blue-brown ratio for each eye. Furthermore, an image clustering approach has been used with promising results. The approach is based on using a sparse dictionary of feature vectors learned from a training set of iris regions. The feature vectors contain both local structural...... information and colour information. For each iris an explanatory histogram is build, containing information about the weighted occurrence of each visual word. A hierarchical agglomerative clustering of the entire set of photos is performed using the distance between the explanatory histograms. The approach...

  12. A patient with multiple iris | Asselman | Southern African Journal of ...

    African Journals Online (AJOL)

    IRIS results from a pathological inflammatory response to pre-existing infective, host or other antigens, alive or dead, causing clinical deterioration in HIV-infected patients after initiating ART.1 A case definition for IRIS is shown in Table I. The most common forms of IRIS described occur in association with mycobacterial and ...

  13. Eyelid Localization for Iris Identification

    Directory of Open Access Journals (Sweden)

    T. Ea

    2008-12-01

    Full Text Available This article presents a new eyelid localization algorithm based on a parabolic curve fitting. To deal with eyelashes, low contrast or false detection due to iris texture, we propose a two steps algorithm. First, possible edge candidates are selected by applying edge detection on a restricted area inside the iris. Then, a gradient maximization is applied along every parabola, on a larger area, to refine parameters and select the best one. Experiments have been conducted on a database of 151 iris that have been manually segmented. The performance evaluation is carried out by comparing the segmented images obtained by the proposed method with the manual segmentation. The results are satisfactory in more than 90% of the cases.

  14. The Economics of IRIS

    International Nuclear Information System (INIS)

    Miller, K.; Paramonov, D.

    2002-01-01

    IRIS (International Reactor Innovative and Secure) is a small to medium advanced light water cooled modular reactor being developed by an international consortium led by Westinghouse/BNFL. This reactor design is specifically aimed at utilities looking to install new (or replacement) nuclear capacity to match market demands, or at developing countries for their distributed power needs. To determine the optimal configuration for IRIS, analysis was undertaken to establish Generation Costs ($/MWh) and Internal Rate of Return (IRR %) to the Utility at alternative power ratings. This was then combined with global market projections for electricity demand out to 2030, segmented into key geographical regions. Finally this information is brought together to form insights, conclusions and recommendations regarding the optimal design. The resultant analysis reveals a single module sized at 335 MWe, with a construction period of 3 years and a 60-year plant life. Individual modules can be installed in a staggered fashion (3 equivalent to 1005 MWe) or built in pairs (2 sets of twin units' equivalent to 1340 MWe). Uncertainty in Market Clearing Price for electricity, Annual Operating Costs and Construction Costs primarily influence lifetime Net Present Values (NPV) and hence IRR % for Utilities. Generation Costs in addition are also influenced by Fuel Costs, Plant Output, Plant Availability and Plant Capacity Factor. Therefore for a site based on 3 single modules, located in North America, Generations Costs of 28.5 $/MWh are required to achieve an IRR of 20%, a level which enables IRIS to compete with all other forms of electricity production. Plant size is critical to commercial success. Sustained (lifetime) high factors for Plant Output, Availability and Capacity Factor are required to achieve a competitive advantage. Modularity offers Utilities the option to match their investments with market conditions, adding additional capacity as and when the circumstances are right

  15. Gender is a major factor explaining discrepancies in eye colour prediction based on HERC2/OCA2 genotype and the IrisPlex model

    OpenAIRE

    Martínez-Cadenas, Conrado; Peña Chilet, María; Ibarrola-Villava, Maider; Ribas, Gloria

    2013-01-01

    In recent years, several studies have greatly increased our understanding of the genetic basis underlying human eye colour variation. A large percentage of the eye colour diversity present in humans can already be genetically explained, so much so that different DNA-based eye colour prediction models, such as IrisPlex, have been recently developed for forensic purposes. Though these models are already highly accurate, they are by no means perfect, with many genotype-phenotype discrepancies st...

  16. Feature Vector Construction Method for IRIS Recognition

    Science.gov (United States)

    Odinokikh, G.; Fartukov, A.; Korobkin, M.; Yoo, J.

    2017-05-01

    One of the basic stages of iris recognition pipeline is iris feature vector construction procedure. The procedure represents the extraction of iris texture information relevant to its subsequent comparison. Thorough investigation of feature vectors obtained from iris showed that not all the vector elements are equally relevant. There are two characteristics which determine the vector element utility: fragility and discriminability. Conventional iris feature extraction methods consider the concept of fragility as the feature vector instability without respect to the nature of such instability appearance. This work separates sources of the instability into natural and encodinginduced which helps deeply investigate each source of instability independently. According to the separation concept, a novel approach of iris feature vector construction is proposed. The approach consists of two steps: iris feature extraction using Gabor filtering with optimal parameters and quantization with separated preliminary optimized fragility thresholds. The proposed method has been tested on two different datasets of iris images captured under changing environmental conditions. The testing results show that the proposed method surpasses all the methods considered as a prior art by recognition accuracy on both datasets.

  17. Dynamical Downscaling of Seasonal Climate Prediction over Nordeste Brazil with ECHAM3 and NCEP's Regional Spectral Models at IRI.

    Science.gov (United States)

    Nobre, Paulo; Moura, Antonio D.; Sun, Liqiang

    2001-12-01

    This study presents an evaluation of a seasonal climate forecast done with the International Research Institute for Climate Prediction (IRI) dynamical forecast system (regional model nested into a general circulation model) over northern South America for January-April 1999, encompassing the rainy season over Brazil's Nordeste. The one-way nesting is one in two tiers: first the NCEP's Regional Spectral Model (RSM) runs with an 80-km grid mesh forced by the ECHAM3 atmospheric general circulation model (AGCM) outputs; then the RSM runs with a finer grid mesh (20 km) forced by the forecasts generated by the RSM-80. An ensemble of three realizations is done. Lower boundary conditions over the oceans for both ECHAM and RSM model runs are sea surface temperature forecasts over the tropical oceans. Soil moisture is initialized by ECHAM's inputs. The rainfall forecasts generated by the regional model are compared with those of the AGCM and observations. It is shown that the regional model at 80-km resolution improves upon the AGCM rainfall forecast, reducing both seasonal bias and root-mean-square error. On the other hand, the RSM-20 forecasts presented larger errors, with spatial patterns that resemble those of local topography. The better forecast of the position and width of the intertropical convergence zone (ITCZ) over the tropical Atlantic by the RSM-80 model is one of the principal reasons for better-forecast scores of the RSM-80 relative to the AGCM. The regional model improved the spatial as well as the temporal details of rainfall distribution, and also presenting the minimum spread among the ensemble members. The statistics of synoptic-scale weather variability on seasonal timescales were best forecast with the regional 80-km model over the Nordeste. The possibility of forecasting the frequency distribution of dry and wet spells within the rainy season is encouraging.

  18. IRIS Toxicological Review of Tetrahydrofuran (THF) ...

    Science.gov (United States)

    EPA is releasing the draft report, Toxicological Review of Tetrahydrofuran, that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from other Federal agencies and White House Offices are provided below with external peer review panel comments. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for tetrahydrofuran. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effects that may result from chronic (or lifetime) exposure to chemicals in the environment. IRIS contains chemical-specific summaries of qualitative and quantitative health information in support of two steps of the risk assessment paradigm, i.e., hazard identification and dose-response evaluation. IRIS assessments are used in combination with specific situational exposure assessment information to evaluate potential public health risk associated with environmental contaminants.

  19. Preliminary ATWS analysis for the IRIS PRA

    International Nuclear Information System (INIS)

    Maddalena Barra; Marco S Ghisu; David J Finnicum; Luca Oriani

    2005-01-01

    Full text of publication follows: The pressurized light water cooled, medium power (1000 MWt) IRIS (International Reactor Innovative and Secure) has been under development for four years by an international consortium of over 21 organizations from ten countries. The plant conceptual design was completed in 2001 and the preliminary design is nearing completion. The pre-application licensing process with NRC started in October, 2002. IRIS has been primarily focused on establishing a design with innovative safety characteristics. The first line of defense in IRIS is to eliminate event initiators that could potentially lead to core damage. In IRIS, this concept is implemented through the 'safety by design' approach, which allows to minimize the number and complexity of the safety systems and required operator actions. The end result is a design with significantly reduced complexity and improved operability, and extensive plant simplifications to enhance construction. To support the optimization of the plant design and confirm the effectiveness of the safety by design approach in mitigating or eliminating events and thus providing a significant reduction in the probability of severe accidents, the PRA is being used as an integral part of the design process. A preliminary but extensive Level 1 PRA model has been developed to support the pre-application licensing of the IRIS design. As a result of the Preliminary IRIS PRA, an optimization of the design from a reliability point of view was completed, and an extremely low (about 1.2 E -8 ) core damage frequency (CDF) was assessed to confirm the impact of the safety by design approach. This first assessment is a result of a PRA model including internal initiating events. During this assessment, several assumptions were necessary to complete the CDF evaluation. In particular Anticipated Transients Without Scram (ATWS) were not included in this initial assessment, because their contribution to core damage frequency was assumed

  20. On techniques for angle compensation in nonideal iris recognition.

    Science.gov (United States)

    Schuckers, Stephanie A C; Schmid, Natalia A; Abhyankar, Aditya; Dorairaj, Vivekanand; Boyce, Christopher K; Hornak, Lawrence A

    2007-10-01

    The popularity of the iris biometric has grown considerably over the past two to three years. Most research has been focused on the development of new iris processing and recognition algorithms for frontal view iris images. However, a few challenging directions in iris research have been identified, including processing of a nonideal iris and iris at a distance. In this paper, we describe two nonideal iris recognition systems and analyze their performance. The word "nonideal" is used in the sense of compensating for off-angle occluded iris images. The system is designed to process nonideal iris images in two steps: 1) compensation for off-angle gaze direction and 2) processing and encoding of the rotated iris image. Two approaches are presented to account for angular variations in the iris images. In the first approach, we use Daugman's integrodifferential operator as an objective function to estimate the gaze direction. After the angle is estimated, the off-angle iris image undergoes geometric transformations involving the estimated angle and is further processed as if it were a frontal view image. The encoding technique developed for a frontal image is based on the application of the global independent component analysis. The second approach uses an angular deformation calibration model. The angular deformations are modeled, and calibration parameters are calculated. The proposed method consists of a closed-form solution, followed by an iterative optimization procedure. The images are projected on the plane closest to the base calibrated plane. Biorthogonal wavelets are used for encoding to perform iris recognition. We use a special dataset of the off-angle iris images to quantify the performance of the designed systems. A series of receiver operating characteristics demonstrate various effects on the performance of the nonideal-iris-based recognition system.

  1. Iridium Interfacial Stack (IRIS)

    Science.gov (United States)

    Spry, David James (Inventor)

    2015-01-01

    An iridium interfacial stack ("IrIS") and a method for producing the same are provided. The IrIS may include ordered layers of TaSi.sub.2, platinum, iridium, and platinum, and may be placed on top of a titanium layer and a silicon carbide layer. The IrIS may prevent, reduce, or mitigate against diffusion of elements such as oxygen, platinum, and gold through at least some of its layers.

  2. Atmospheric Deposition Modeling Results

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset provides data on model results for dry and total deposition of sulfur, nitrogen and base cation species. Components include deposition velocities, dry...

  3. Deep Learning-Based Iris Segmentation for Iris Recognition in Visible Light Environment

    Directory of Open Access Journals (Sweden)

    Muhammad Arsalan

    2017-11-01

    Full Text Available Existing iris recognition systems are heavily dependent on specific conditions, such as the distance of image acquisition and the stop-and-stare environment, which require significant user cooperation. In environments where user cooperation is not guaranteed, prevailing segmentation schemes of the iris region are confronted with many problems, such as heavy occlusion of eyelashes, invalid off-axis rotations, motion blurs, and non-regular reflections in the eye area. In addition, iris recognition based on visible light environment has been investigated to avoid the use of additional near-infrared (NIR light camera and NIR illuminator, which increased the difficulty of segmenting the iris region accurately owing to the environmental noise of visible light. To address these issues; this study proposes a two-stage iris segmentation scheme based on convolutional neural network (CNN; which is capable of accurate iris segmentation in severely noisy environments of iris recognition by visible light camera sensor. In the experiment; the noisy iris challenge evaluation part-II (NICE-II training database (selected from the UBIRIS.v2 database and mobile iris challenge evaluation (MICHE dataset were used. Experimental results showed that our method outperformed the existing segmentation methods.

  4. Iris recognition based on key image feature extraction.

    Science.gov (United States)

    Ren, X; Tian, Q; Zhang, J; Wu, S; Zeng, Y

    2008-01-01

    In iris recognition, feature extraction can be influenced by factors such as illumination and contrast, and thus the features extracted may be unreliable, which can cause a high rate of false results in iris pattern recognition. In order to obtain stable features, an algorithm was proposed in this paper to extract key features of a pattern from multiple images. The proposed algorithm built an iris feature template by extracting key features and performed iris identity enrolment. Simulation results showed that the selected key features have high recognition accuracy on the CASIA Iris Set, where both contrast and illumination variance exist.

  5. TAPIOCA MELANOMA OF THE IRIS

    NARCIS (Netherlands)

    DEKEIZER, RJW; OOSTERHUIS, JA; HOUTMAN, WA; DEWOLFFROUENDAAL, D

    Clinical identification of tapioca melanoma of the iris is important because its medical treatment may differ from that of other malignant iris melanomas. The characteristic iris nodules must be differentiated from granulomatous uveitis, metastases, and Lisch nodules (neurofibromatosis). We will

  6. Trade off between variable and fixed size normalization in orthogonal polynomials based iris recognition system.

    Science.gov (United States)

    Krishnamoorthi, R; Anna Poorani, G

    2016-01-01

    Iris normalization is an important stage in any iris biometric, as it has a propensity to trim down the consequences of iris distortion. To indemnify the variation in size of the iris owing to the action of stretching or enlarging the pupil in iris acquisition process and camera to eyeball distance, two normalization schemes has been proposed in this work. In the first method, the iris region of interest is normalized by converting the iris into the variable size rectangular model in order to avoid the under samples near the limbus border. In the second method, the iris region of interest is normalized by converting the iris region into a fixed size rectangular model in order to avoid the dimensional discrepancies between the eye images. The performance of the proposed normalization methods is evaluated with orthogonal polynomials based iris recognition in terms of FAR, FRR, GAR, CRR and EER.

  7. Use of IRI to Model the Effect of Ionosphere Emission on Earth Remote Sensing at L-Band

    Science.gov (United States)

    Abraham, Saji; LeVine, David M.

    2004-01-01

    Microwave remote sensing in the window at 1.413 GHz (L-band) set aside for passive use only is important for monitoring sea surface salinity and soil moisture. These parameters are important for understanding ocean dynamics and energy exchange between the surface and atmosphere, and both NASA and ESA plan to launch satellite sensors to monitor these parameters at L-band (Aquarius, Hydros and SMOS). The ionosphere is an important source of error for passive remote sensing at this frequency. In addition to Faraday rotation, emission from the ionosphere is also a potential source of error at L-band. As an aid for correcting for emission, a regression model is presented that relates ionosphere emission to the integrated electron density (TEC). The goal is to use TEC from sources such as TOPEX, JASON or GPS to obtain estimates of emission over the oceans where the electron density profiles needed to compute emission are not available. In addition, data will also be presented to evaluate the use of the IRI for computing emission over the ocean.

  8. Iris and periocular biometrics

    CERN Document Server

    Rathgeb, Christian

    2017-01-01

    This book provides an overview of scientific fundamentals and principles of iris and periocular biometric recognition. It covers: an introduction to iris and periocular recognition; a selective overview of issues and challenges; soft biometric classification; security aspects; privacy protection and forensics; and future trends.

  9. Dynamic Features for Iris Recognition.

    Science.gov (United States)

    da Costa, R M; Gonzaga, A

    2012-08-01

    The human eye is sensitive to visible light. Increasing illumination on the eye causes the pupil of the eye to contract, while decreasing illumination causes the pupil to dilate. Visible light causes specular reflections inside the iris ring. On the other hand, the human retina is less sensitive to near infra-red (NIR) radiation in the wavelength range from 800 nm to 1400 nm, but iris detail can still be imaged with NIR illumination. In order to measure the dynamic movement of the human pupil and iris while keeping the light-induced reflexes from affecting the quality of the digitalized image, this paper describes a device based on the consensual reflex. This biological phenomenon contracts and dilates the two pupils synchronously when illuminating one of the eyes by visible light. In this paper, we propose to capture images of the pupil of one eye using NIR illumination while illuminating the other eye using a visible-light pulse. This new approach extracts iris features called "dynamic features (DFs)." This innovative methodology proposes the extraction of information about the way the human eye reacts to light, and to use such information for biometric recognition purposes. The results demonstrate that these features are discriminating features, and, even using the Euclidean distance measure, an average accuracy of recognition of 99.1% was obtained. The proposed methodology has the potential to be "fraud-proof," because these DFs can only be extracted from living irises.

  10. Comparison of GPS-derived TEC with IRI-2012 and IRI-2007 TEC predictions at Surat, a location around the EIA crest in the Indian sector, during the ascending phase of solar cycle 24

    Science.gov (United States)

    Patel, N. C.; Karia, S. P.; Pathak, K. N.

    2017-07-01

    This paper presents a comparison of GPS-derived TEC with IRI-2012 and IRI-2007 TEC Predictions at Surat (21.16°N Geographic latitude, 72.78°E Geographic longitude, 12.90°N Geomagnetic latitude) a location around the Equatorial Ionisation Anomaly (EIA) crest in the Indian sector, during the Ascending Phase of Solar Cycle 24, for a period of three years (January 2010-December 2012). In this comparison, plasmaspheric electron content (PEC) contribution to the GPS-TEC has been removed. It is observed that percentage PEC contribution to the GPS-TEC varies from about ∼15% (at the noon local time) to about ∼30% (at the morning local time). From the monthly comparison of GPS-TEC with IRI-TEC, it is observed that, TEC predicted by both the models overestimates in June-2012 and underestimates TEC in November-2011, December-2011 and March-2011. For all other months IRI estimates the TEC well. From the seasonal comparison, it is observed that the peak time appears ∼1-h later than the actual peak time in Winter 2010, Summer 2011, and Equinox 2010 and 2012 (the result suggest that it may be due to discrepancies/disagreement of both the versions of the IRI model in estimating the peak density as well as the thickness and shape parameters of the electron density profiles). For the Summer season, the IRI-TEC estimates the TEC well for all the years. Further, the seasonal variation of the GPS-TEC for all the three years matches well with IRI-2012 model compared to IRI-2007 model. Also, the mean annual TEC is predicted well by both the versions of the IRI model.

  11. Improved iris localization by using wide and narrow field of view cameras for iris recognition

    Science.gov (United States)

    Kim, Yeong Gon; Shin, Kwang Yong; Park, Kang Ryoung

    2013-10-01

    Biometrics is a method of identifying individuals by their physiological or behavioral characteristics. Among other biometric identifiers, iris recognition has been widely used for various applications that require a high level of security. When a conventional iris recognition camera is used, the size and position of the iris region in a captured image vary according to the X, Y positions of a user's eye and the Z distance between a user and the camera. Therefore, the searching area of the iris detection algorithm is increased, which can inevitably decrease both the detection speed and accuracy. To solve these problems, we propose a new method of iris localization that uses wide field of view (WFOV) and narrow field of view (NFOV) cameras. Our study is new as compared to previous studies in the following four ways. First, the device used in our research acquires three images, one each of the face and both irises, using one WFOV and two NFOV cameras simultaneously. The relation between the WFOV and NFOV cameras is determined by simple geometric transformation without complex calibration. Second, the Z distance (between a user's eye and the iris camera) is estimated based on the iris size in the WFOV image and anthropometric data of the size of the human iris. Third, the accuracy of the geometric transformation between the WFOV and NFOV cameras is enhanced by using multiple matrices of the transformation according to the Z distance. Fourth, the searching region for iris localization in the NFOV image is significantly reduced based on the detected iris region in the WFOV image and the matrix of geometric transformation corresponding to the estimated Z distance. Experimental results showed that the performance of the proposed iris localization method is better than that of conventional methods in terms of accuracy and processing time.

  12. IRIS Responsiveness to Generation IV Road-map Goals

    International Nuclear Information System (INIS)

    Carelli, M.D.; Paramonov, D.V.; Petrovic, B.

    2002-01-01

    The DOE Generation IV road-map process is in its second and final year. Almost one hundred concepts submitted from all over the world have been reviewed against the Generation IV goals of resources sustainability; safety and reliability; and, economics. Advanced LWRs are taken as the reference point. IRIS (International Reactor Innovative and Secure), a 100-335 MWe integral light water reactor being developed by a vast international consortium led by Westinghouse, is one on the concepts being considered in the road-map and is perhaps the most visible representative of the concept set known as Integral Primary System Reactors (IPSR). This paper presents how IRIS satisfies the prescribed goals. The first goal of resource sustainability includes criteria like utilization of fuel resources, amount and toxicity of waste produced, environmental impact, proliferation and sabotage resistance. As a thermal reactor IRIS does not have the same fuel utilization as fast reactors. However, it has a significant flexibility in fuel cycles as it is designed to utilize either UO 2 or MOX with straight burn cycles of 4 to 10 years, depending on the fissile content. High discharge burnup and Pu recycling result in good fuel utilization and lower waste; IRIS has also attractive proliferation resistance characteristics, due to the reduced accessibility of the fuel. The safety and reliability goal include reliability, workers' exposure, robust safety features, models with well characterized uncertainty, source term and mechanisms of energy release, robust mitigation of accidents. IRIS is significantly better than advanced LWRs because of its safety by design which eliminates a variety of accidents such as LOCAs, its containment vessel coupled design which maintains the core safely covered during the accident sequences, its design simplification features such as no (or reduced) soluble boron, internal shielding and four-year refueling/maintenance interval which significantly reduce

  13. IRIS core criticality calculations

    International Nuclear Information System (INIS)

    Jecmenica, R.; Trontl, K.; Pevec, D.; Grgic, D.

    2003-01-01

    Three-dimensional Monte Carlo computer code KENO-VI of CSAS26 sequence of SCALE-4.4 code system was applied for pin-by-pin calculations of the effective multiplication factor for the first cycle IRIS reactor core. The effective multiplication factors obtained by the above mentioned Monte Carlo calculations using 27-group ENDF/B-IV library and 238-group ENDF/B-V library have been compared with the effective multiplication factors achieved by HELIOS/NESTLE, CASMO/SIMULATE, and modified CORD-2 nodal calculations. The results of Monte Carlo calculations are found to be in good agreement with the results obtained by the nodal codes. The discrepancies in effective multiplication factor are typically within 1%. (author)

  14. Role of Arbuscular Mycorrhizal Fungi on Iris

    Directory of Open Access Journals (Sweden)

    CHEN Yuan

    2014-06-01

    Full Text Available For efficiency using the amphibious plant iris to restore polluted water, the promoting effect of different arbuscular mycorrhiza fungi(AMFon iris was investigated, by monitoring the plant growth index, the physicochemical properties of the soil and the plant photosynthesis indexes. The result showed that the promoting effects of the AMF on the aboveground part and the underground part of the iris were based on different mechanism. For the underground part of the iris, the AMF stimulated its growth through the nutrient enrichment which was performed by the enormous hypha network. The nitrogen absorbing rate of the G. mosseae and the G. intraradices infected iris increased about 71.75% and 42.55%, and the phosphorous absorbing rate increased 8.36% and 9.5% separately. For the aboveground part of the iris, the AMF strengthened the conductance of the leaves’ stomas to control the balance between the net photosynthesis rate and the transpiration rate, so that the utilization rate of water resources was optimized, the metabolic rate was accelerated and the growth of the plant was promoted eventually. In this study, the promoting effect of the G. mosseae on the photosynthesis rate of the iris was significantly better than that of the G. intraradices(P<0.05.

  15. LOCA analysis of the IRIS reactor

    International Nuclear Information System (INIS)

    Bajs, T.; Grgic, D.; Cavlina, N.

    2003-01-01

    The IRIS reactor (International Reactor Innovative and Secure) is an integral, light water cooled, medium power reactor. IRIS has been selected as an International Near Term Deployable (INTD) reactor, within the Generation IV International Forum activities. The IRIS concept addresses the key-requirements defined by the US DOE for next generation reactors, i.e. enhanced reliability and safety, and improved economics. It features innovative, advanced engineering, but it is firmly based on the proven technology of pressurized water reactors (PWR). An innovative safety approach has been developed to mitigate the IRIS response to small-to-medium Loss of Coolant Accident (LOCA). This strategy is based on the interaction of IRIS compact containment with the reactor vessel to limit initial blowdown, and on depressurization through the use of a passive Emergency Heat Removal System (EHRS). A small Automatic Depressurization System (ADS) provides supplementary depressurization capability. A pressure suppression system is provided to limit the pressure peak following the initial blowdown to well below the containment design limit. The ultimate result is that during a small-to-medium LOCA, the core remains covered for an extended period of time, without credit for emergency water injection or external core makeup. The IRIS LOCA response is based on 'maintaining water inventory' rather than on the principle of safety injection. This novel safety approach poses significant issues for computational and analysis methods since the IRIS vessel and containment are strongly coupled, and the system response is based on the interaction between the two. The small break LOCA was calculated using RELAP5/mod3.3 and GOTHIC codes. Break of the largest line connected to the IRIS Reactor Pressure Vessel (RPV) was analyzed. The results of the calculations confirmed good performance of the IRIS system during LOCA. (author)

  16. Edge detection techniques for iris recognition system

    International Nuclear Information System (INIS)

    Tania, U T; Motakabber, S M A; Ibrahimy, M I

    2013-01-01

    Nowadays security and authentication are the major parts of our daily life. Iris is one of the most reliable organ or part of human body which can be used for identification and authentication purpose. To develop an iris authentication algorithm for personal identification, this paper examines two edge detection techniques for iris recognition system. Between the Sobel and the Canny edge detection techniques, the experimental result shows that the Canny's technique has better ability to detect points in a digital image where image gray level changes even at slow rate

  17. Feature and Score Fusion Based Multiple Classifier Selection for Iris Recognition

    Directory of Open Access Journals (Sweden)

    Md. Rabiul Islam

    2014-01-01

    Full Text Available The aim of this work is to propose a new feature and score fusion based iris recognition approach where voting method on Multiple Classifier Selection technique has been applied. Four Discrete Hidden Markov Model classifiers output, that is, left iris based unimodal system, right iris based unimodal system, left-right iris feature fusion based multimodal system, and left-right iris likelihood ratio score fusion based multimodal system, is combined using voting method to achieve the final recognition result. CASIA-IrisV4 database has been used to measure the performance of the proposed system with various dimensions. Experimental results show the versatility of the proposed system of four different classifiers with various dimensions. Finally, recognition accuracy of the proposed system has been compared with existing N hamming distance score fusion approach proposed by Ma et al., log-likelihood ratio score fusion approach proposed by Schmid et al., and single level feature fusion approach proposed by Hollingsworth et al.

  18. Three-batch reloading scheme for IRIS reactor extended cycles

    International Nuclear Information System (INIS)

    Jecmenica, R.; Pevec, D.; Grgic, D.

    2004-01-01

    To fully exploit the IRIS reactor optimized maintenance, and at the same time improve fuel utilization, a core design enabling a 4-year operating cycle together with a three-batch reloading scheme is desirable. However, this requires not only the increased allowed burnup but also use of fuel with uranium oxide enriched beyond 5%. This paper considers three-batch reloading scheme for a 4-year operating cycle with the assumptions of increased discharge burnup and fuel enrichment beyond 5%. Calculational model of IRIS reactor core has been developed based on FER FA2D code for group constants generation and NRC's PARCS nodal code for global core analysis. Studies have been performed resulting in a preliminary design of a three-batch core configuration for the first cycle. It must be emphasized that this study is outside the current IRIS licensing efforts, which rely on the present fuel technology (enrichment below 5%), but it is of long-term interest for potential future IRIS design upgrades. (author)

  19. [Intraoperative floppy iris syndrome].

    Science.gov (United States)

    Mazal, Z

    2007-04-01

    In the year 2005, Chang and Cambell described unusual reaction of the iris during the cataract surgery in patients treated with tamsulosine. This was named as IFIS, an acronym for the Intraoperative Floppy Iris Syndrome. In its advanced stage, the syndrome is characterized by insufficient mydfiasis before the surgery, narrowing of the pupil during the surgery, its impossible dilatation during the surgery by means of stretching, unusual elasticity of the pupilar margin, surging and fluttering iris with tendency to prolapse. The same manifestations we observed in our patients and we confirm the direct connection with tamsulosine hydrochloride treatment. Tamsulosine is the antagonist of alpha 1A adrenergic receptors whose are present, except in the smooth musculature of the prostate gland and the urinary bladder, in the iris dilator as well. At the same time we observed this syndrome rarely in some patients not using tamsulosine. In most cases, these patients were treated with antipsychotic drugs.

  20. Transient analysis of the IRIS reactor

    International Nuclear Information System (INIS)

    Bajs, T.; Oriani, L.; Ricotti, M.E.; Barroso, A.C.

    2002-01-01

    An international consortium of industry, laboratory, university and utility establishments, led by Westinghouse, is developing a modular, integral, light water cooled, small to medium power reactor, the International Reactor Innovative and Secure (IRIS). IRIS features innovative, advanced engineering, but it is firmly based on the proven technology of pressurized water reactors (PWR). Given the large number of organizations involved in the IRIS design, the RELAP5/MOD 3.3 code has been selected as the main system code. A nodalization of the reference IRIS design has been developed with a basic set of protective functions and controls. Engineered Safety Features of the concept are being also implemented, and in particular the Emergency Heat Removal System that is used for safety grade decay heat removal and in the small break LOCA response of IRIS (Large break LOCAs are eliminated in IRIS by the adoption of the Integral layout) This paper discusses developed model and transient behavior of the system for representative transient sequences.(author)

  1. Iris reconstruction using artificial iris prosthesis for management of aniridia.

    Science.gov (United States)

    Mostafa, Yehia S; Osman, Amr A; Hassanein, Dina H; Zeid, Ashraf M; Sherif, Ahmed M

    2018-01-01

    To discuss the limitations and benefits of the BrightOcular prosthetic artificial iris device in management of aniridia associated with aphakia or cataract. This is a retrospective study including 5 eyes of 4 patients who underwent implantation of the BrightOcular iris prosthesis (Stellar Devices) for total or partial aniridia. The cases included 2 eyes of 1 patient with congenital aniridia associated with congenital cataract and 3 eyes with traumatic aniridia: 1 with subluxated cataractous lens and 2 with aphakia. In all cases, the iris prosthesis was implanted after a 3-piece acrylic intraocular lens was implanted. We evaluated the clinical course with a minimum follow-up period of 6 months, the intraoperative and postoperative complications, and the cosmetic satisfaction of patients. All patients had improved uncorrected distance visual acuity and best-corrected distance visual acuity. All patients had a transient corneal edema that resolved within the first postoperative week. Only the patient with congenital aniridia had a permanent increase in intraocular pressure and developed a band keratopathy throughout a 2-year follow-up period. The prosthesis was well-centered in all eyes except for one case that required scleral suture fixation after 3 months. All patients had a satisfactory cosmetic appearance. BrightOcular iris prosthesis is a safe and useful tool to correct aniridia associated with pseudophakia or aphakia. Being foldable, it is easy to be implanted through a small incision and placed in the ciliary sulcus without sutures when properly sized. Cosmetic results are satisfactory. Sizing methods should be improved.

  2. Antigen-Specific Interferon-Gamma Responses and Innate Cytokine Balance in TB-IRIS

    Science.gov (United States)

    Goovaerts, Odin; Jennes, Wim; Massinga-Loembé, Marguerite; Ceulemans, Ann; Worodria, William; Mayanja-Kizza, Harriet; Colebunders, Robert; Kestens, Luc

    2014-01-01

    Background Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) remains a poorly understood complication in HIV-TB patients receiving antiretroviral therapy (ART). TB-IRIS could be associated with an exaggerated immune response to TB-antigens. We compared the recovery of IFNγ responses to recall and TB-antigens and explored in vitro innate cytokine production in TB-IRIS patients. Methods In a prospective cohort study of HIV-TB co-infected patients treated for TB before ART initiation, we compared 18 patients who developed TB-IRIS with 18 non-IRIS controls matched for age, sex and CD4 count. We analyzed IFNγ ELISpot responses to CMV, influenza, TB and LPS before ART and during TB-IRIS. CMV and LPS stimulated ELISpot supernatants were subsequently evaluated for production of IL-12p70, IL-6, TNFα and IL-10 by Luminex. Results Before ART, all responses were similar between TB-IRIS patients and non-IRIS controls. During TB-IRIS, IFNγ responses to TB and influenza antigens were comparable between TB-IRIS patients and non-IRIS controls, but responses to CMV and LPS remained significantly lower in TB-IRIS patients. Production of innate cytokines was similar between TB-IRIS patients and non-IRIS controls. However, upon LPS stimulation, IL-6/IL-10 and TNFα/IL-10 ratios were increased in TB-IRIS patients compared to non-IRIS controls. Conclusion TB-IRIS patients did not display excessive IFNγ responses to TB-antigens. In contrast, the reconstitution of CMV and LPS responses was delayed in the TB-IRIS group. For LPS, this was linked with a pro-inflammatory shift in the innate cytokine balance. These data are in support of a prominent role of the innate immune system in TB-IRIS. PMID:25415590

  3. The fast iris image clarity evaluation based on Tenengrad and ROI selection

    Science.gov (United States)

    Gao, Shuqin; Han, Min; Cheng, Xu

    2018-04-01

    In iris recognition system, the clarity of iris image is an important factor that influences recognition effect. In the process of recognition, the blurred image may possibly be rejected by the automatic iris recognition system, which will lead to the failure of identification. Therefore it is necessary to evaluate the iris image definition before recognition. Considered the existing evaluation methods on iris image definition, we proposed a fast algorithm to evaluate the definition of iris image in this paper. In our algorithm, firstly ROI (Region of Interest) is extracted based on the reference point which is determined by using the feature of the light spots within the pupil, then Tenengrad operator is used to evaluate the iris image's definition. Experiment results show that, the iris image definition algorithm proposed in this paper could accurately distinguish the iris images of different clarity, and the algorithm has the merit of low computational complexity and more effectiveness.

  4. Iris unwrapping using the Bresenham circle algorithm for real-time iris recognition

    Science.gov (United States)

    Carothers, Matthew T.; Ngo, Hau T.; Rakvic, Ryan N.; Broussard, Randy P.

    2015-02-01

    An efficient parallel architecture design for the iris unwrapping process in a real-time iris recognition system using the Bresenham Circle Algorithm is presented in this paper. Based on the characteristics of the model parameters this algorithm was chosen over the widely used polar conversion technique as the iris unwrapping model. The architecture design is parallelized to increase the throughput of the system and is suitable for processing an inputted image size of 320 × 240 pixels in real-time using Field Programmable Gate Array (FPGA) technology. Quartus software is used to implement, verify, and analyze the design's performance using the VHSIC Hardware Description Language. The system's predicted processing time is faster than the modern iris unwrapping technique used today∗.

  5. Optimal wavelength band clustering for multispectral iris recognition.

    Science.gov (United States)

    Gong, Yazhuo; Zhang, David; Shi, Pengfei; Yan, Jingqi

    2012-07-01

    This work explores the possibility of clustering spectral wavelengths based on the maximum dissimilarity of iris textures. The eventual goal is to determine how many bands of spectral wavelengths will be enough for iris multispectral fusion and to find these bands that will provide higher performance of iris multispectral recognition. A multispectral acquisition system was first designed for imaging the iris at narrow spectral bands in the range of 420 to 940 nm. Next, a set of 60 human iris images that correspond to the right and left eyes of 30 different subjects were acquired for an analysis. Finally, we determined that 3 clusters were enough to represent the 10 feature bands of spectral wavelengths using the agglomerative clustering based on two-dimensional principal component analysis. The experimental results suggest (1) the number, center, and composition of clusters of spectral wavelengths and (2) the higher performance of iris multispectral recognition based on a three wavelengths-bands fusion.

  6. Optical Coherence Tomography Angiography Characteristics of Iris Melanocytic Tumors

    Science.gov (United States)

    Skalet, Alison H.; Li, Yan; Lu, Chen D.; Jia, Yali; Lee, ByungKun; Husvogt, Lennart; Maier, Andreas; Fujimoto, James G.; Thomas, Charles R.; Huang, David

    2016-01-01

    Objective To evaluate tumor vasculature with optical coherence tomography (OCT) angiography (OCTA) in malignant iris melanomas and benign iris lesions. Design Cross-sectional observational clinical study. Participants Patients with iris lesions and healthy volunteers. Methods Eyes were imaged using OCTA systems operating at 1050 and 840 nm wavelengths. Three-dimensional OCTA scans were acquired. Iris melanomas patients treated with radiation therapy were imaged again after I-125 plaque brachytherapy at 6 and 18 months. Main Outcome Measures OCT and OCTA images, qualitative evaluation of iris and tumor vasculature and quantitative vessel density. Results One eye each of eight normal volunteers and nine patients with iris melanomas or benign iris lesions including freckles, nevi, and an iris pigment epithelial (IPE) cyst were imaged. The normal iris has radially-oriented vessels within the stroma on OCTA. Penetration of flow signal in normal iris depended on iris color, with best penetration seen in light to moderately pigmented irides. Iris melanomas demonstrated tortuous and disorganized intratumoral vasculature. In two eyes with nevi there was no increased vascularity; in another, fine vascular loops were noted near an area of ectropion uveae. Iris freckles and the IPE cyst did not have intrinsic vascularity. The vessel density was significantly higher within iris melanomas (34.5%±9.8%, piris nevi (8.0%±1.4%) or normal irides (8.0%±1.2%). Tumor regression after radiation therapy for melanomas was associated with decreased vessel density. OCTA at 1050 nm provided better visualization of tumor vasculature and penetration through thicker tumors than at 840 nm. But in very thick tumors and highly pigmented lesions even 1050 nm OCTA could not visualize their full thickness. Interpretable OCTA images were obtained in 82% participants in whom imaging was attempted. Conclusions This is the first demonstration of OCTA in iris tumors. OCTA may provide a dye-free, no

  7. Primary iris leiomyoma.

    Science.gov (United States)

    Yeaney, Gabrielle A; Platt, Sean; Singh, Arun D

    Intraocular leiomyomas are uncommon and usually occur in the ciliary body. Primary leiomyoma of the iris is both rare and a difficult diagnosis to make, given melanocytic tumors are more common and may be amelanotic. The somewhat controversial diagnosis of iris leiomyoma requires further confirmation by immunohistochemistry and electron microscopy. Herein, we describe a 58-year-old man with a 2-mm round translucent pink lesion of the iris. The tumor was excised by sector iridectomy. Immunohistochemistry showed positivity for both smooth muscle actin and desmin and negativity for S-100, HMB45, SOX10, MelanA, CD31, CD34, and h-caldesmon. Epstein-Barr virus-associated smooth muscle tumor was excluded by chromogenic in situ hybridization-Epstein-Barr virus-encoded RNA. Ultrastructural analysis showed cytoplasmic myofilaments with focal fusiform densities and micropinocytotic vesicles. Our review of previous literature confirmed the unusual nature of this tumor. Primary iris leiomyoma should be considered in the differential of an amelanotic S-100-immunonegative iris tumor. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Inertial Movements of the Iris as the Origin of Postsaccadic Oscillations

    Science.gov (United States)

    Bouzat, S.; Freije, M. L.; Frapiccini, A. L.; Gasaneo, G.

    2018-04-01

    Recent studies on the human eye indicate that the pupil moves inside the eyeball due to deformations of the iris. Here we show that this phenomenon can be originated by inertial forces undergone by the iris during the rotation of the eyeball. Moreover, these forces affect the iris in such a way that the pupil behaves effectively as a massive particle. To show this, we develop a model based on the Newton equation on the noninertial reference frame of the eyeball. The model allows us to reproduce and interpret several important findings of recent eye-tracking experiments on saccadic movements. In particular, we get correct results for the dependence of the amplitude and period of the postsaccadic oscillations on the saccade size and also for the peak velocity. The model developed may serve as a tool for characterizing eye properties of individuals.

  9. Gabor Weber Local Descriptor for Bovine Iris Recognition

    Directory of Open Access Journals (Sweden)

    Shengnan Sun

    2013-01-01

    Full Text Available Iris recognition is a robust biometric technology. This paper proposes a novel local descriptor for bovine iris recognition, named Gabor Weber local descriptor (GWLD. We first compute the Gabor magnitude maps for the input bovine iris image, and then calculate the differential excitation and orientation for each pixel over each Gabor magnitude map. After that, we use these differential excitations and orientations to construct the GWLD histogram representation. Finally, histogram intersection is adopted to measure the similarity between different GWLD histograms. The experimental results on the SEU bovine iris database verify the representation power of our proposed local descriptor.

  10. Multispectral iris recognition based on group selection and game theory

    Science.gov (United States)

    Ahmad, Foysal; Roy, Kaushik

    2017-05-01

    A commercially available iris recognition system uses only a narrow band of the near infrared spectrum (700-900 nm) while iris images captured in the wide range of 405 nm to 1550 nm offer potential benefits to enhance recognition performance of an iris biometric system. The novelty of this research is that a group selection algorithm based on coalition game theory is explored to select the best patch subsets. In this algorithm, patches are divided into several groups based on their maximum contribution in different groups. Shapley values are used to evaluate the contribution of patches in different groups. Results show that this group selection based iris recognition

  11. Iris - nimi marmortahvlilt / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2003-01-01

    Briti kirjanikust Iris Murdochist pajatava inglise-ameerika mängufilmist "Iris" eesti videolevisse jõudmise puhul. Võrreldakse inglise teatrilavastaja Richard Eyre filmidebüüti Elmo Nüganeni debüütfilmiga "Nimed marmortahvlil"

  12. Iris reactor development

    International Nuclear Information System (INIS)

    Paramonov, D.V.; Carelli, M.D.; Miller, K.; Lombardi, C.V.; Ricotti, M.E.; Todreas, N.E.; Greenspan, E.; Yamamoto, K.; Nagano, A.; Ninokata, H.; Robertson, J.; Oriolo, F.

    2001-01-01

    The development progress of the IRIS (International Reactor Innovative and Secure) nuclear power system is presented. IRIS is currently being developed by an international consortium of industry, laboratory, university and utility establishments, led by Westinghouse. It is aimed at achieving the four major objectives of the Generation IV nuclear systems, i.e., proliferation resistance, enhanced safety, economic competitiveness and reduced waste. The project first year activities, which are summarized here, were focused on core neutronics, in-vessel configuration, steam generator and containment design, safety approach and economic performance. Details of these studies are provided in parallel papers in these proceedings. (author)

  13. Iris double recognition based on modified evolutionary neural network

    Science.gov (United States)

    Liu, Shuai; Liu, Yuan-Ning; Zhu, Xiao-Dong; Huo, Guang; Liu, Wen-Tao; Feng, Jia-Kai

    2017-11-01

    Aiming at multicategory iris recognition under illumination and noise interference, this paper proposes a method of iris double recognition based on a modified evolutionary neural network. An equalization histogram and Laplace of Gaussian operator are used to process the iris to suppress illumination and noise interference and Haar wavelet to convert the iris feature to binary feature encoding. Calculate the Hamming distance for the test iris and template iris , and compare with classification threshold, determine the type of iris. If the iris cannot be identified as a different type, there needs to be a secondary recognition. The connection weights in back-propagation (BP) neural network use modified evolutionary neural network to adaptively train. The modified neural network is composed of particle swarm optimization with mutation operator and BP neural network. According to different iris libraries in different circumstances of experimental results, under illumination and noise interference, the correct recognition rate of this algorithm is higher, the ROC curve is closer to the coordinate axis, the training and recognition time is shorter, and the stability and the robustness are better.

  14. An iris recognition algorithm based on DCT and GLCM

    Science.gov (United States)

    Feng, G.; Wu, Ye-qing

    2008-04-01

    With the enlargement of mankind's activity range, the significance for person's status identity is becoming more and more important. So many different techniques for person's status identity were proposed for this practical usage. Conventional person's status identity methods like password and identification card are not always reliable. A wide variety of biometrics has been developed for this challenge. Among those biologic characteristics, iris pattern gains increasing attention for its stability, reliability, uniqueness, noninvasiveness and difficult to counterfeit. The distinct merits of the iris lead to its high reliability for personal identification. So the iris identification technique had become hot research point in the past several years. This paper presents an efficient algorithm for iris recognition using gray-level co-occurrence matrix(GLCM) and Discrete Cosine transform(DCT). To obtain more representative iris features, features from space and DCT transformation domain are extracted. Both GLCM and DCT are applied on the iris image to form the feature sequence in this paper. The combination of GLCM and DCT makes the iris feature more distinct. Upon GLCM and DCT the eigenvector of iris extracted, which reflects features of spatial transformation and frequency transformation. Experimental results show that the algorithm is effective and feasible with iris recognition.

  15. Iris recognition in the presence of ocular disease.

    Science.gov (United States)

    Aslam, Tariq Mehmood; Tan, Shi Zhuan; Dhillon, Baljean

    2009-05-06

    Iris recognition systems are among the most accurate of all biometric technologies with immense potential for use in worldwide security applications. This study examined the effect of eye pathology on iris recognition and in particular whether eye disease could cause iris recognition systems to fail. The experiment involved a prospective cohort of 54 patients with anterior segment eye disease who were seen at the acute referral unit of the Princess Alexandra Eye Pavilion in Edinburgh. Iris camera images were obtained from patients before treatment was commenced and again at follow-up appointments after treatment had been given. The principal outcome measure was that of mathematical difference in the iris recognition templates obtained from patients' eyes before and after treatment of the eye disease. Results showed that the performance of iris recognition was remarkably resilient to most ophthalmic disease states, including corneal oedema, iridotomies (laser puncture of iris) and conjunctivitis. Problems were, however, encountered in some patients with acute inflammation of the iris (iritis/anterior uveitis). The effects of a subject developing anterior uveitis may cause current recognition systems to fail. Those developing and deploying iris recognition should be aware of the potential problems that this could cause to this key biometric technology.

  16. Iris recognition as a biometric method after cataract surgery

    Directory of Open Access Journals (Sweden)

    Roizenblatt Jaime

    2004-01-01

    Full Text Available Abstract Background Biometric methods are security technologies, which use human characteristics for personal identification. Iris recognition systems use iris textures as unique identifiers. This paper presents an analysis of the verification of iris identities after intra-ocular procedures, when individuals were enrolled before the surgery. Methods Fifty-five eyes from fifty-five patients had their irises enrolled before a cataract surgery was performed. They had their irises verified three times before and three times after the procedure, and the Hamming (mathematical distance of each identification trial was determined, in a controlled ideal biometric environment. The mathematical difference between the iris code before and after the surgery was also compared to a subjective evaluation of the iris anatomy alteration by an experienced surgeon. Results A correlation between visible subjective iris texture alteration and mathematical difference was verified. We found only six cases in which the eye was no more recognizable, but these eyes were later reenrolled. The main anatomical changes that were found in the new impostor eyes are described. Conclusions Cataract surgeries change iris textures in such a way that iris recognition systems, which perform mathematical comparisons of textural biometric features, are able to detect these changes and sometimes even discard a pre-enrolled iris considering it an impostor. In our study, re-enrollment proved to be a feasible procedure.

  17. Numerical stress analysis of the iris tissue induced by pupil expansion: Comparison of commercial devices

    Science.gov (United States)

    Wang, Xiaofei; Perera, Shamira A.; Girard, Michaël J. A.

    2018-01-01

    Purpose (1) To use finite element (FE) modelling to estimate local iris stresses (i.e. internal forces) as a result of mechanical pupil expansion; and to (2) compare such stresses as generated from several commercially available expanders (Iris hooks, APX dilator and Malyugin ring) to determine which design and deployment method are most likely to cause iris damage. Methods We used a biofidelic 3-part iris FE model that consisted of the stroma, sphincter and dilator muscles. Our FE model simulated expansion of the pupil from 3 mm to a maximum of 6 mm using the aforementioned pupil expanders, with uniform circular expansion used for baseline comparison. FE-derived stresses, resultant forces and area of final pupil opening were compared across devices for analysis. Results Our FE models demonstrated that the APX dilator generated the highest stresses on the sphincter muscles, (max: 6.446 MPa; average: 5.112 MPa), followed by the iris hooks (max: 5.680 MPa; average: 5.219 MPa), and the Malyugin ring (max: 2.144 MPa; average: 1.575 MPa). Uniform expansion generated the lowest stresses (max: 0.435MPa; average: 0.377 MPa). For pupil expansion, the APX dilator required the highest force (41.22 mN), followed by iris hooks (40.82 mN) and the Malyugin ring (18.56 mN). Conclusion Our study predicted that current pupil expanders exert significantly higher amount of stresses and forces than required during pupil expansion. Our work may serve as a guide for the development and design of next-generation pupil expanders. PMID:29538452

  18. IRI STORM validation over Europe

    Science.gov (United States)

    Haralambous, Haris; Vryonides, Photos; Demetrescu, Crişan; Dobrică, Venera; Maris, Georgeta; Ionescu, Diana

    2014-05-01

    The International Reference Ionosphere (IRI) model includes an empirical Storm-Time Ionospheric Correction Model (STORM) extension to account for storm-time changes of the F layer peak electron density (NmF2) during increased geomagnetic activity. This model extension is driven by past history values of the geomagnetic index ap (The magnetic index applied is the integral of ap over the previous 33 hours with a weighting function deduced from physically based modeling) and it adjusts the quiet-time F layer peak electron density (NmF2) to account for storm-time changes in the ionosphere. In this investigation manually scaled hourly values of NmF2 measured during the main and recovery phases of selected storms for the maximum solar activity period of the current solar cycle are compared with the predicted IRI-2012 NmF2 over European ionospheric stations using the STORM model option. Based on the comparison a subsequent performance evaluation of the STORM option during this period is quantified.

  19. Using crypts as iris minutiae

    Science.gov (United States)

    Shen, Feng; Flynn, Patrick J.

    2013-05-01

    Iris recognition is one of the most reliable biometric technologies for identity recognition and verification, but it has not been used in a forensic context because the representation and matching of iris features are not straightforward for traditional iris recognition techniques. In this paper we concentrate on the iris crypt as a visible feature used to represent the characteristics of irises in a similar way to fingerprint minutiae. The matching of crypts is based on their appearances and locations. The number of matching crypt pairs found between two irises can be used for identity verification and the convenience of manual inspection makes iris crypts a potential candidate for forensic applications.

  20. Integrated analysis for a small break LOCA in the IRIS reactor using MELCOR and RELAP5 codes

    International Nuclear Information System (INIS)

    Del Nevo, A.; Manfredini, A.; Oriolo, F.; Paci, S.; Oriani, L.

    2004-01-01

    The pressurized light water cooled, medium power (1000 MWt) IRIS (International Reactor Innovative and Secure) has been under development for four years by an international consortium of over 21 organizations from ten countries. The plant conceptual design was completed in 2001 and the preliminary design is nearing completion. The pre-application licensing process with NRC started in October, 2002 and IRIS is one of the designs considered by US utilities as part of the ESP (Early Site Permit) process. This paper's focus is on the use of well known computer codes for integrated (reactor vessel and containment) calculations of the IRIS response to a small break loss of coolant accident (LOCA). In IRIS, large break LOCA events are eliminated by the use of a layout configuration in which the reactor vessel contains all the reactor coolant system components including the core, control rod drive mechanisms, pressurizer, steam generators, and coolant pumps. Thus the IRIS configuration has no large loop piping; also, no pipes with a diameter greater than 0.1 meters are part of the reactor coolant system boundary. For small break LOCAs, IRIS features an innovative mitigation approach that is based on maintaining coolant inventory rather than designing high and low pressure injection systems to provide makeup coolant to the reactor to maintain core cooling. The novel IRIS approach requires development of evaluation models that are different from those used for the current generation of pressurized water reactors. An analysis of small break LOCAs for IRIS is documented in two companion papers, and has been developed using a preliminary evaluation model based on the explicit coupling of the RELAP5 and GOTHIC codes. The objective of this paper is to compare the results obtained via the coupled RELAP/GOTHIC code with different computational tools. A reference case from the preliminary IRIS safety assessment was selected, and the same small break LOCA sequence is analyzed using

  1. Iris metastasis of gastric adenocarcinoma.

    Science.gov (United States)

    Celebi, Ali Riza Cenk; Kilavuzoglu, Ayse Ebru; Altiparmak, U Emrah; Cosar, C Banu; Ozkiris, Abdullah

    2016-03-08

    Iris metastasis in patients with gastric cancer is extremely rare. Herein, it is aimed to report on a patient with gastric adenocarcinoma and iris metastasis. A 65-year-old patient with the history of gastric cancer was admitted for eye pain and eye redness on his left eye. There was ciliary injection, severe +4 cells with hypopyon in the anterior chamber and a solitary, friable, yellow-white, fleshy-creamy vascularized 2 mm × 4 mm mass on the upper nasal part of the iris within the left eye. The presented patient's mass lesion in the iris fulfilled the criteria of the metastatic iris lesion's appearance. The ocular metastasis occurred during chemotherapy. Iris metastasis can masquerade as iridocyclitis with pseudohypopyon or glaucoma. In patients with a history of gastric cancer that present with an iris mass, uveitis, and high intraocular pressure, ocular metastasis of gastric cancer should be a consideration.

  2. Image compression with Iris-C

    Science.gov (United States)

    Gains, David

    2009-05-01

    Iris-C is an image codec designed for streaming video applications that demand low bit rate, low latency, lossless image compression. To achieve compression and low latency the codec features the discrete wavelet transform, Exp-Golomb coding, and online processes that construct dynamic models of the input video. Like H.264 and Dirac, the Iris-C codec accepts input video from both the YUV and YCOCG colour spaces, but the system can also operate on Bayer RAW data read directly from an image sensor. Testing shows that the Iris-C codec is competitive with the Dirac low delay syntax codec which is typically regarded as the state-of-the-art low latency, lossless video compressor.

  3. Proton beam radiotherapy of iris melanoma

    International Nuclear Information System (INIS)

    Damato, Bertil; Kacperek, Andrzej; Chopra, Mona; Sheen, Martin A.; Campbell, Ian R.; Errington, R. Douglas

    2005-01-01

    Purpose: To report on outcomes after proton beam radiotherapy of iris melanoma. Methods and Materials: Between 1993 and 2004, 88 patients with iris melanoma received proton beam radiotherapy, with 53.1 Gy in 4 fractions. Results: The patients had a mean age of 52 years and a median follow-up of 2.7 years. The tumors had a median diameter of 4.3 mm, involving more than 2 clock hours of iris in 32% of patients and more than 2 hours of angle in 27%. The ciliary body was involved in 20%. Cataract was present in 13 patients before treatment and subsequently developed in another 18. Cataract had a 4-year rate of 63% and by Cox analysis was related to age (p = 0.05), initial visual loss (p < 0.0001), iris involvement (p < 0.0001), and tumor thickness (p < 0.0001). Glaucoma was present before treatment in 13 patients and developed after treatment in another 3. Three eyes were enucleated, all because of recurrence, which had an actuarial 4-year rate of 3.3% (95% CI 0-8.0%). Conclusions: Proton beam radiotherapy of iris melanoma is well tolerated, the main problems being radiation-cataract, which was treatable, and preexisting glaucoma, which in several patients was difficult to control

  4. High-frequency ultrasound measurements of the normal ciliary body and iris.

    Science.gov (United States)

    Garcia, Julian P S; Spielberg, Leigh; Finger, Paul T

    2011-01-01

    To determine the normal ultrasonographic thickness of the iris and ciliary body. This prospective 35-MHz ultrasonographic study included 80 normal eyes of 40 healthy volunteers. The images were obtained at the 12-, 3-, 6-, and 9-o'clock radial meridians, measured at three locations along the radial length of the iris and at the thickest section of the ciliary body. Mixed model was used to estimate eye site-adjusted means and standard errors and to test the statistical difference of adjusted results. Parameters included mean thickness, standard deviation, and range. Mean thicknesses at the iris root, midway along the radial length of the iris, and at the juxtapupillary margin were 0.4 ± 0.1, 0.5 ± 0.1, and 0.6 ± 0.1 mm, respectively. Those of the ciliary body, ciliary processes, and ciliary body + ciliary processes were 0.7 ± 0.1, 0.6 ± 0.1, and 1.3 ± 0.2 mm, respectively. This study provides standard, normative thickness data for the iris and ciliary body in healthy adults using ultrasonographic imaging. Copyright 2011, SLACK Incorporated.

  5. Correlation of iris biometrics and DNA

    DEFF Research Database (Denmark)

    Harder, Stine; Clemmensen, Line Katrine Harder; Dahl, Anders Bjorholm

    2013-01-01

    The presented work concerns prediction of complex human phenotypes from genotypes. We were interested in correlating iris color and texture with DNA. Our data consist of 212 eye images along with DNA: 32 single-nucleotide polymorphisms (SNPs). We used two types of biometrics to describe the eye...... images: One for iris color and one for iris texture. Both biometrics were high dimensional and a sparse principle component analysis (SPCA) reduced the dimensions and resulted in a representation of data with good interpretability. The correlations between the sparse principal components (SPCs......) and the 32 SNPs were found using a canonical correlation analysis (CCA). The result was a single significant canonical correlation (CC) for both biometrics. Each CC comprised two correlated canonical variables, consisting of a linear combination of SPCs and a linear combination of SNPs, respectively...

  6. Effect of tamsulosin on iris vasculature and morphology

    Science.gov (United States)

    Shtein, Roni M.; Hussain, Munira T.; Cooney, Theresa M.; Elner, Victor M.; Hood, Christopher T.

    2015-01-01

    PURPOSE To determine whether preoperative iris vasculature and morphology are altered in patients who have taken tamsulosin (Flomax). SETTING Academic multispecialty practice. DESIGN Case series. METHODS Patients with current or past tamsulosin use and age- and sex-matched control patients were included. Anterior segment optical coherence tomography (AS-OCT) and iris fluorescein angiography were performed to measure iris vasculature and thickness before cataract surgery. Data collected at surgery included pupil diameter, clinical signs of intraoperative floppy-iris syndrome, and surgical complications. RESULTS Tamsulosin was currently used by 16 patients and in the past by 4 patients; the control group comprised 10 patients. Pharmacologically dilated pupil diameter was significantly smaller preoperatively and immediately postoperatively in the tamsulosin group than in the control group (P = .009 and P = .003, respectively). There was a statistically significant decrease in pupil size intraoperatively in the tamsulosin group (P = .05) but not in the control group (P = .3). Iris-vasculature parameters, specifically time to first vessel fill and percentage of vessel fill on iris fluorescein angiography, were not significantly different between the 2 groups. The AS-OCT measurements of iris morphology were not statistically significantly different between the groups. No surgical complications occurred. No fluorescein dye leakage, staining, or other vascular anomalies were observed. CONCLUSIONS Although there were differences in pupil measurements and intraoperative iris behavior between patients who had been on tamsulosin and control patients, there were no significant differences in iris vasculature on iris fluorescein angiography or in iris morphology on AS-OCT. PMID:24631201

  7. Iris reconstruction combined with iris-claw intraocular lens implantation for the management of iris-lens injured patients.

    Science.gov (United States)

    Hu, Shufang; Wang, Mingling; Xiao, Tianlin; Zhao, Zhenquan

    2016-03-01

    To study the efficiency and safety of iris reconstruction combined with iris-claw intraocular lens (IOL) implantation in the patients with iris-lens injuries. Retrospective, noncomparable consecutive case series study. Eleven patients (11 eyes) following iris-lens injuries underwent iris reconstructions combined with iris-claw IOL implantations. Clinical data, such as cause and time of injury, visual acuity (VA), iris and lens injuries, surgical intervention, follow-up period, corneal endothelial cell count, and optical coherence tomography, were collected. Uncorrected VA (UCVA) in all injured eyes before combined surgery was equal to or iris returned to its natural round shape or smaller pupil, and the iris-claw IOLs in the 11 eyes were well-positioned on the anterior surface of reconstructed iris. No complications occurred in those patients. Iris reconstruction combined with iris-claw IOL implantation is a safe and efficient procedure for an eye with iris-lens injury in the absence of capsular support.

  8. Eclipse-Free-Time Assessment Tool for IRIS

    Science.gov (United States)

    Eagle, David

    2012-01-01

    IRIS_EFT is a scientific simulation that can be used to perform an Eclipse-Free- Time (EFT) assessment of IRIS (Infrared Imaging Surveyor) mission orbits. EFT is defined to be those time intervals longer than one day during which the IRIS spacecraft is not in the Earth s shadow. Program IRIS_EFT implements a special perturbation of orbital motion to numerically integrate Cowell's form of the system of differential equations. Shadow conditions are predicted by embedding this integrator within Brent s method for finding the root of a nonlinear equation. The IRIS_EFT software models the effects of the following types of orbit perturbations on the long-term evolution and shadow characteristics of IRIS mission orbits. (1) Non-spherical Earth gravity, (2) Atmospheric drag, (3) Point-mass gravity of the Sun, and (4) Point-mass gravity of the Moon. The objective of this effort was to create an in-house computer program that would perform eclipse-free-time analysis. of candidate IRIS spacecraft mission orbits in an accurate and timely fashion. The software is a suite of Fortran subroutines and data files organized as a "computational" engine that is used to accurately predict the long-term orbit evolution of IRIS mission orbits while searching for Earth shadow conditions.

  9. IRIS Toxicological Review of Inorganic Arsenic (Cancer) ...

    Science.gov (United States)

    EPA's Science Advisory Board (SAB) conducted a review of the scientific basis supporting the human health cancer hazard and dose-response assessment of inorganic arsenic that will appear on the Integrated Risk Information System (IRIS) database. EPA revised the assessment and is now returning the assessment to the SAB and releasing the document to the public for a focused review of EPA's responses to the SAB recommendations. This draft IRIS health assessment addresses only cancer human health effects that may result from chronic exposure to this chemical.

  10. Simplified safety and containment systems for the iris reactor

    International Nuclear Information System (INIS)

    Conway, L.E.; Lombardi, C.; Ricotti, M.; Oriani, L.

    2001-01-01

    The IRIS (International Reactor Innovative and Secure) is a 100 - 300 MW modular type pressurized water reactor supported by the U.S. DOE NERI Program. IRIS features a long-life core to provide proliferation resistance and to reduce the volume of spent fuel, as well as reduce maintenance requirements. IRIS utilizes an integral reactor vessel that contains all major primary system components. This integral reactor vessel makes it possible to reduce containment size; making the IRIS more cost competitive. IRIS is being designed to enhance reactor safety, and therefore a key aspect of the IRIS program is the development of the safety and containment systems. These systems are being designed to maximize containment integrity, prevent core uncover following postulated accidents, minimize the probability and consequences of severe accidents, and provide a significant simplification over current safety system designs. The design of the IRIS containment and safety systems has been identified and preliminary analyses have been completed. The IRIS safety concept employs some unique features that minimize the consequences of postulated design basis events. This paper will provide a description of the containment design and safety systems, and will summarize the analysis results. (author)

  11. Iris Recognition for Partially Occluded Images: Methodology and Sensitivity Analysis

    Directory of Open Access Journals (Sweden)

    Poursaberi A

    2007-01-01

    Full Text Available Accurate iris detection is a crucial part of an iris recognition system. One of the main issues in iris segmentation is coping with occlusion that happens due to eyelids and eyelashes. In the literature, some various methods have been suggested to solve the occlusion problem. In this paper, two different segmentations of iris are presented. In the first algorithm, a circle is located around the pupil with an appropriate diameter. The iris area encircled by the circular boundary is used for recognition purposes then. In the second method, again a circle is located around the pupil with a larger diameter. This time, however, only the lower part of the encircled iris area is utilized for individual recognition. Wavelet-based texture features are used in the process. Hamming and harmonic mean distance classifiers are exploited as a mixed classifier in suggested algorithm. It is observed that relying on a smaller but more reliable part of the iris, though reducing the net amount of information, improves the overall performance. Experimental results on CASIA database show that our method has a promising performance with an accuracy of 99.31%. The sensitivity of the proposed method is analyzed versus contrast, illumination, and noise as well, where lower sensitivity to all factors is observed when the lower half of the iris is used for recognition.

  12. Iris reactor conceptual design

    International Nuclear Information System (INIS)

    Carelli, M.D.; Conway, L.E.; Petrovic, B.; Paramonov, D.V.; Galvin, M.; Todreas, N.E.; Lombardi, C.V.; Maldari, F.; Ricotti, M.E.; Cinotti, L.

    2001-01-01

    IRIS (International Reactor Innovative and Secure) is a modular, integral, light water cooled, low-to-medium power (100-350 MWe) reactor which addresses the requirements defined by the US DOE for Generation IV reactors, i.e., proliferation resistance, enhanced safety, improved economics and fuel cycle sustainability. It relies on the proven technology of light water reactors and features innovative engineering, but it does not require new technology development. This paper discusses the current reference IRIS design, which features a 1000 MWt thermal core with proven 5%-enriched uranium oxide fuel and five-year long straight burn fuel cycle, integral reactor vessel housing helical tube steam generators and immersed spool pumps. Other major contributors to the high level of safety and economic attractiveness are the safety by design and optimized maintenance approaches, which allow elimination of some classes of accidents, lower capital cost, long operating cycle, and high capacity factors. (author)

  13. IRiS: construction of ARG networks at genomic scales.

    Science.gov (United States)

    Javed, Asif; Pybus, Marc; Melé, Marta; Utro, Filippo; Bertranpetit, Jaume; Calafell, Francesc; Parida, Laxmi

    2011-09-01

    Given a set of extant haplotypes IRiS first detects high confidence recombination events in their shared genealogy. Next using the local sequence topology defined by each detected event, it integrates these recombinations into an ancestral recombination graph. While the current system has been calibrated for human population data, it is easily extendible to other species as well. IRiS (Identification of Recombinations in Sequences) binary files are available for non-commercial use in both Linux and Microsoft Windows, 32 and 64 bit environments from https://researcher.ibm.com/researcher/view_project.php?id = 2303 parida@us.ibm.com.

  14. IRIS Toxicological Review of n-Butanol (External Review Draft ...

    Science.gov (United States)

    EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of n-butanol that will appear in the Integrated Risk Information System (IRIS) database. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for n-butanol. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effects that may result from chronic (or lifetime) exposure to chemicals in the environment. IRIS contains chemical-specific summaries of qualitative and quantitative health information in support of two steps of the risk assessment paradigm, i.e., hazard identification and dose-response evaluation. IRIS assessments are used in combination with specific situational exposure assessment information to evaluate potential public health risk associated with environmental contaminants.

  15. Cataract influence on iris recognition performance

    Science.gov (United States)

    Trokielewicz, Mateusz; Czajka, Adam; Maciejewicz, Piotr

    2014-11-01

    This paper presents the experimental study revealing weaker performance of the automatic iris recognition methods for cataract-affected eyes when compared to healthy eyes. There is little research on the topic, mostly incorporating scarce databases that are often deficient in images representing more than one illness. We built our own database, acquiring 1288 eye images of 37 patients of the Medical University of Warsaw. Those images represent several common ocular diseases, such as cataract, along with less ordinary conditions, such as iris pattern alterations derived from illness or eye trauma. Images were captured in near-infrared light (used in biometrics) and for selected cases also in visible light (used in ophthalmological diagnosis). Since cataract is a disorder that is most populated by samples in the database, in this paper we focus solely on this illness. To assess the extent of the performance deterioration we use three iris recognition methodologies (commercial and academic solutions) to calculate genuine match scores for healthy eyes and those influenced by cataract. Results show a significant degradation in iris recognition reliability manifesting by worsening the genuine scores in all three matchers used in this study (12% of genuine score increase for an academic matcher, up to 175% of genuine score increase obtained for an example commercial matcher). This increase in genuine scores affected the final false non-match rate in two matchers. To our best knowledge this is the only study of such kind that employs more than one iris matcher, and analyzes the iris image segmentation as a potential source of decreased reliability

  16. Integrated risk information system (IRIS)

    Energy Technology Data Exchange (ETDEWEB)

    Tuxen, L. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    The Integrated Risk Information System (IRIS) is an electronic information system developed by the US Environmental Protection Agency (EPA) containing information related to health risk assessment. IRIS is the Agency`s primary vehicle for communication of chronic health hazard information that represents Agency consensus following comprehensive review by intra-Agency work groups. The original purpose for developing IRIS was to provide guidance to EPA personnel in making risk management decisions. This original purpose for developing IRIS was to guidance to EPA personnel in making risk management decisions. This role has expanded and evolved with wider access and use of the system. IRIS contains chemical-specific information in summary format for approximately 500 chemicals. IRIS is available to the general public on the National Library of Medicine`s Toxicology Data Network (TOXNET) and on diskettes through the National Technical Information Service (NTIS).

  17. A novel iris patterns matching algorithm of weighted polar frequency correlation

    Science.gov (United States)

    Zhao, Weijie; Jiang, Linhua

    2014-11-01

    Iris recognition is recognized as one of the most accurate techniques for biometric authentication. In this paper, we present a novel correlation method - Weighted Polar Frequency Correlation(WPFC) - to match and evaluate two iris images, actually it can also be used for evaluating the similarity of any two images. The WPFC method is a novel matching and evaluating method for iris image matching, which is complete different from the conventional methods. For instance, the classical John Daugman's method of iris recognition uses 2D Gabor wavelets to extract features of iris image into a compact bit stream, and then matching two bit streams with hamming distance. Our new method is based on the correlation in the polar coordinate system in frequency domain with regulated weights. The new method is motivated by the observation that the pattern of iris that contains far more information for recognition is fine structure at high frequency other than the gross shapes of iris images. Therefore, we transform iris images into frequency domain and set different weights to frequencies. Then calculate the correlation of two iris images in frequency domain. We evaluate the iris images by summing the discrete correlation values with regulated weights, comparing the value with preset threshold to tell whether these two iris images are captured from the same person or not. Experiments are carried out on both CASIA database and self-obtained images. The results show that our method is functional and reliable. Our method provides a new prospect for iris recognition system.

  18. Real-time image restoration for iris recognition systems.

    Science.gov (United States)

    Kang, Byung Jun; Park, Kang Ryoung

    2007-12-01

    In the field of biometrics, it has been reported that iris recognition techniques have shown high levels of accuracy because unique patterns of the human iris, which has very many degrees of freedom, are used. However, because conventional iris cameras have small depth-of-field (DOF) areas, input iris images can easily be blurred, which can lead to lower recognition performance, since iris patterns are transformed by the blurring caused by optical defocusing. To overcome these problems, an autofocusing camera can be used. However, this inevitably increases the cost, size, and complexity of the system. Therefore, we propose a new real-time iris image-restoration method, which can increase the camera's DOF without requiring any additional hardware. This paper presents five novelties as compared to previous works: 1) by excluding eyelash and eyelid regions, it is possible to obtain more accurate focus scores from input iris images; 2) the parameter of the point spread function (PSF) can be estimated in terms of camera optics and measured focus scores; therefore, parameter estimation is more accurate than it has been in previous research; 3) because the PSF parameter can be obtained by using a predetermined equation, iris image restoration can be done in real-time; 4) by using a constrained least square (CLS) restoration filter that considers noise, performance can be greatly enhanced; and 5) restoration accuracy can also be enhanced by estimating the weight value of the noise-regularization term of the CLS filter according to the amount of image blurring. Experimental results showed that iris recognition errors when using the proposed restoration method were greatly reduced as compared to those results achieved without restoration or those achieved using previous iris-restoration methods.

  19. IRIS-economics review

    International Nuclear Information System (INIS)

    Miller, K.

    2005-01-01

    IRIS is a medium sized advanced light water cooled modular reactor being developed by an international Group led by Westinghouse/BNFL. This reactor design is aimed at a broad spectrum of Utilities looking to install nuclear capacity to match market demands, or at emerging Nations with specific financial constraints looking to strategically optimise their debit levels. The IRIS building block is a multiple module sized at 335 MWe, with a construction period of 3 years and a 60-year plant life. Modules can be installed individually or in parks. In the latter case, deployment can be in single modules or in pairs (twin-unit); both will be built in staggered fashion at time intervals as dictated by economic and market considerations. One of the unique features of IRIS is its ability to offer reduction in costs through increased experience 'Learning' at a single site: In construction, the principal benefit is derived for subsequent modules, and is dependent on maintaining the 'core' team throughout. This is particularly important if there is any significant period between the completion of say module 1 and the start of module 2. This time frame will be driven by the overall market size, projected growth in demand and the level of financial risk the utility is prepared to accept. Learning benefits in construction are derived from skills and experience retention impacting on reducing the number of inputs and construction time. Learning in operation may benefit from a certain delay between modules as this allows operators to build up their 'cumulative experience'. Reactor operations on day 1 would be significantly different from those of say 3 years later. These benefits would be passed on to modules 2 and 3, which would realise them from day 1. Learning in operation is dependent on the ability to retain within the organisation knowledge and records of key events. The benefits from Learning in operation may also be applicable to different sites, in different countries. It

  20. NeQuick 2 and IRI Plas VTEC predictions for low latitude and South American sector

    Science.gov (United States)

    Ezquer, R. G.; Scidá, L. A.; Migoya Orué, Y.; Nava, B.; Cabrera, M. A.; Brunini, C.

    2018-04-01

    Using vertical total electron content (VTEC) measurements obtained from GPS satellite signals the capability of the NeQuick 2 and IRI Plas models to predict VTEC over the low latitude and South American sector is analyzed. In the present work both models were used to calculate VTEC up to the height of GPS satellites. Also, comparisons between the performance of IRI Plas and IRI 2007 have been done. The data correspond to June solstice and September equinox 1999 (high solar activity) and they were obtained at nine stations. The considered latitude range extends from 18.4°N to -64.7°N and the longitude ranges from 281.3°E to 295.9°E in the South American sector. The greatest discrepancies among model predictions and the measured VTEC are obtained at low latitudes stations placed in the equatorial anomaly region. Underestimations as strong as 40 TECU [1 TECU = 1016 m-2] can be observed at BOGT station for September equinox, when NeQuick2 model is used. The obtained results also show that: (a) for June solstice, in general the performance of IRI Plas for low latitude stations is better than that of NeQuick2 and, vice versa, for highest latitudes the performance of NeQuick2 is better than that of IRI Plas. For the stations TUCU and SANT both models have good performance; (b) for September equinox the performances of the models do not follow a clearly defined pattern as in the other season. However, it can be seen that for the region placed between the Northern peak and the valley of the equatorial anomaly, in general, the performance of IRI Plas is better than that of NeQuick2 for hours of maximum ionization. From TUCU to the South, the best TEC predictions are given by NeQuick2. The source of the observed deviations of the models has been explored in terms of CCIR foF2 determination in the available ionosonde stations in the region. Discrepancies can be also related to an unrealistic shape of the vertical electron density profile and or an erroneous prediction of

  1. IRIS Mission Operations Director's Colloquium

    Science.gov (United States)

    Carvalho, Robert; Mazmanian, Edward A.

    2014-01-01

    Pursuing the Mysteries of the Sun: The Interface Region Imaging Spectrograph (IRIS) Mission. Flight controllers from the IRIS mission will present their individual experiences on IRIS from development through the first year of flight. This will begin with a discussion of the unique nature of IRISs mission and science, and how it fits into NASA's fleet of solar observatories. Next will be a discussion of the critical roles Ames contributed in the mission including spacecraft and flight software development, ground system development, and training for launch. This will be followed by experiences from launch, early operations, ongoing operations, and unusual operations experiences. The presentation will close with IRIS science imagery and questions.

  2. The IRIS user-guide

    International Nuclear Information System (INIS)

    Adams, M.A.

    1997-10-01

    This is the first version of the IRIS User-Guide. IRIS is continually evolving and improving and so some of the information contained within this manual will become out of date quite quickly. The basics behind the operation of IRIS, however, should remain essentially constant for the foreseeable future. Updated manuals will be produced when appropriate although it should always be remembered that the most up-to-date sources of information concerning IRIS are the instrument scientist and the local contacts for the experiments. It would be appreciated, however, if this user-guide were to be the first point of call. (author)

  3. Iris Segmentation using Gradient Magnitude and Fourier Descriptor for Multimodal Biometric Authentication System

    Directory of Open Access Journals (Sweden)

    Defiana Sulaeman

    2016-12-01

    Full Text Available Perfectly segmenting the area of the iris is one of the most important steps in iris recognition. There are several problematic areas that affect the accuracy of the iris segmentation step, such as eyelids, eyelashes, glasses, pupil (due to less accurate iris segmentation, motion blur, and lighting and specular reflections. To solve these problems, gradient magnitude and Fourier descriptor are employed to do iris segmentation in the proposed Multimodal Biometric Authentication System (MBAS. This approach showed quite promising results, i.e. an accuracy rate of 97%. The result of the iris recognition system was combined with the result of an open-source fingerprint recognition system to develop a multimodal biometrics authentication system. The results of the fusion between iris and fingerprint authentication were 99% accurate. Data from Multimedia Malaysia University (MMUI and our own prepared database, the SGU-MB-1 dataset, were used to test the accuracy of the proposed system.

  4. Multi-wavelength Spectral Analysis of Ellerman Bombs Observed by FISS and IRIS

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jie; Ding, M. D. [School of Astronomy and Space Science, Nanjing University, Nanjing 210023 (China); Cao, Wenda, E-mail: dmd@nju.edu.cn [Big Bear Solar Observatory, New Jersey Institute of Technology, 40386 North Shore Lane, Big Bear City, CA 92314-9672 (United States)

    2017-04-01

    Ellerman bombs (EBs) are a kind of solar activity that is suggested to occur in the lower solar atmosphere. Recent observations using the Interface Region Imaging Spectrograph (IRIS) show connections between EBs and IRIS bombs (IBs), which imply that EBs might be heated to a much higher temperature (8 × 10{sup 4} K) than previous results. Here we perform a spectral analysis of EBs simultaneously observed by the Fast Imaging Solar Spectrograph and IRIS. The observational results show clear evidence of heating in the lower atmosphere, indicated by the wing enhancement in H α , Ca ii 8542 Å, and Mg ii triplet lines and also by brightenings in images of the 1700 Å and 2832 Å ultraviolet continuum channels. Additionally, the intensity of the Mg ii triplet line is correlated with that of H α when an EB occurs, suggesting the possibility of using the triplet as an alternative way to identify EBs. However, we do not find any signal in IRIS hotter lines (C ii and Si iv). For further analysis, we employ a two-cloud model to fit the two chromospheric lines (H α and Ca ii 8542 Å) simultaneously, and obtain a temperature enhancement of 2300 K for a strong EB. This temperature is among the highest of previous modeling results, albeit still insufficient to produce IB signatures at ultraviolet wavelengths.

  5. IRIS Toxicological Review of n-Butanol (Interagency Science ...

    Science.gov (United States)

    On September 8, 2011, the Toxicological Review of n-Butanol (External Review Draft) was released for external peer review and public comment. The Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and White House Offices before public release. In the new IRIS process, introduced by the EPA Administrator, all written comments on IRIS assessments submitted by other federal agencies and White House Offices will be made publicly available. Accordingly, interagency comments with EPA's response and the interagency science consultation draft of the IRIS Toxicological Review of n-Butanol and the charge to external peer reviewers are posted on this site. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for n-butanol. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effects that may result from chronic (or lifetime) exposure to chemicals in the environment. IRIS contains chemical-specific summaries of qualitative and quantitative health information in support of two steps of the risk assessment paradigm, i.e., hazard identification and dose-response evaluation. IRIS assessments are used in combination with specific situational exposure assessment information to evaluate potential public health risk associated with environmental contaminants.

  6. Evaluating the impact of image preprocessing on iris segmentation

    Directory of Open Access Journals (Sweden)

    José F. Valencia-Murillo

    2014-08-01

    Full Text Available Segmentation is one of the most important stages in iris recognition systems. In this paper, image preprocessing algorithms are applied in order to evaluate their impact on successful iris segmentation. The preprocessing algorithms are based on histogram adjustment, Gaussian filters and suppression of specular reflections in human eye images. The segmentation method introduced by Masek is applied on 199 images acquired under unconstrained conditions, belonging to the CASIA-irisV3 database, before and after applying the preprocessing algorithms. Then, the impact of image preprocessing algorithms on the percentage of successful iris segmentation is evaluated by means of a visual inspection of images in order to determine if circumferences of iris and pupil were detected correctly. An increase from 59% to 73% in percentage of successful iris segmentation is obtained with an algorithm that combine elimination of specular reflections, followed by the implementation of a Gaussian filter having a 5x5 kernel. The results highlight the importance of a preprocessing stage as a previous step in order to improve the performance during the edge detection and iris segmentation processes.

  7. Treatment of non-resectable malignant iris tumours with custom designed plaque radiotherapy

    International Nuclear Information System (INIS)

    Shields, C.L.; Shields, J.A.; Potter, P. De; Singh, A.D.; Hernandez, C.; Brady, L.W.

    1995-01-01

    Background- Plaque radiotherapy is the most common method of managing posterior uveal melanoma but its use for iris melanoma and iris metastases has not yet been evaluated. Methods -Fourteen patients with non-resectable iris melanoma and four with iris metastasis were treated with plaque radiotherapy. The tumour response to treatment and the local side effects of the radioactive plaque were evaluated. Results -In the iris melanoma group over a mean follow up of 26 (range 6-75) months, the tumour regressed in 13 of the 14 patients (93%) and recurred as diffuse seeding in one patient (7%). Despite large doses of radiation given transcorneally, the cornea developed epitheliopathy, abraxion, and oedema in only one case each. The major radiation side effects were localised iris vasculopathy without glaucoma in two cases, posterior synechiae in five cases, and cataract in six cases. In the iris metastasis group, tumour regression was observed in all four patients (100%) and radiation side effects were not evident over the relatively short mean follow up period of 8 (range 4-9) months. All of the 14 patients with irradiated iris melanoma have remained systemically healthy without metastasis while three of the four patients with irradiated iris metastases have died of metastases from the primary neoplasm. Conclusion - Custom designed plaque radiotherapy appears to be an effective alternative method of controlling non-resectable diffuse iris melanoma and solitary iris metastasis and has relatively few side effects. (author)

  8. IRIS-2012 OECD/NEA/CSNI benchmark: Numerical simulations of structural impact

    International Nuclear Information System (INIS)

    Orbovic, Nebojsa; Tarallo, Francois; Rambach, Jean-Mathieu; Sagals, Genadijs; Blahoianu, Andrei

    2015-01-01

    A benchmark of numerical simulations related to the missile impact on reinforced concrete (RC) slabs has been launched in the frame of OECD/NEA/CSNI research program “Improving Robustness Assessment Methodologies for Structures Impacted by Missiles”, under the acronym IRIS. The goal of the research program is to simulate RC structural, flexural and punching, behavior under deformable and rigid missile impact. The first phase called IRIS-2010 was a blind prediction of the tests performed at VTT facility in Espoo, Finland. The two simulations were performed related to two series of tests: (1) two tests on the impact of a deformable missile exhibiting damage mainly by flexural (so-called “flexural tests”) or global response and (2) three tests on the impact of a rigid missile exhibiting damage mainly by punching response (so-called “punching tests”) or local response. The simulation results showed significant scatter (coefficient of variation up to 132%) for both flexural and punching cases. The IRIS-2012 is the second, post-test, phase of the benchmark with the goal to improve simulations and reduce the scatter of the results. Based on the IRIS-2010 recommendations and to better calibrate concrete constitutive models, a series of tri-axial tests as well as Brazilian tests were performed as a part of the IRIS-2012 benchmark. 25 teams from 11 countries took part in this exercise. Majority of participants were part of the IRIS-2010 benchmark. Participants showed significant improvement in reducing epistemic uncertainties in impact simulations. Several teams presented both finite element (FE) and simplified analysis as per recommendations of the IRIS-2010. The improvements were at the level of simulation results but also at the level of understanding of impact phenomena and its modeling. Due to the complexity of the physical phenomena and its simulation (high geometric and material non-linear behavior) and inherent epistemic and aleatory uncertainties, the

  9. IRIS-2012 OECD/NEA/CSNI benchmark: Numerical simulations of structural impact

    Energy Technology Data Exchange (ETDEWEB)

    Orbovic, Nebojsa, E-mail: nebojsa.orbovic@cnsc-ccsn.gc.ca [Canadian Nuclear Safety Commission, Ottawa, ON (Canada); Tarallo, Francois [IRSN, Fontenay aux Roses (France); Rambach, Jean-Mathieu [Géodynamique et Structures, Bagneux (France); Sagals, Genadijs; Blahoianu, Andrei [Canadian Nuclear Safety Commission, Ottawa, ON (Canada)

    2015-12-15

    A benchmark of numerical simulations related to the missile impact on reinforced concrete (RC) slabs has been launched in the frame of OECD/NEA/CSNI research program “Improving Robustness Assessment Methodologies for Structures Impacted by Missiles”, under the acronym IRIS. The goal of the research program is to simulate RC structural, flexural and punching, behavior under deformable and rigid missile impact. The first phase called IRIS-2010 was a blind prediction of the tests performed at VTT facility in Espoo, Finland. The two simulations were performed related to two series of tests: (1) two tests on the impact of a deformable missile exhibiting damage mainly by flexural (so-called “flexural tests”) or global response and (2) three tests on the impact of a rigid missile exhibiting damage mainly by punching response (so-called “punching tests”) or local response. The simulation results showed significant scatter (coefficient of variation up to 132%) for both flexural and punching cases. The IRIS-2012 is the second, post-test, phase of the benchmark with the goal to improve simulations and reduce the scatter of the results. Based on the IRIS-2010 recommendations and to better calibrate concrete constitutive models, a series of tri-axial tests as well as Brazilian tests were performed as a part of the IRIS-2012 benchmark. 25 teams from 11 countries took part in this exercise. Majority of participants were part of the IRIS-2010 benchmark. Participants showed significant improvement in reducing epistemic uncertainties in impact simulations. Several teams presented both finite element (FE) and simplified analysis as per recommendations of the IRIS-2010. The improvements were at the level of simulation results but also at the level of understanding of impact phenomena and its modeling. Due to the complexity of the physical phenomena and its simulation (high geometric and material non-linear behavior) and inherent epistemic and aleatory uncertainties, the

  10. Iris image enhancement for feature recognition and extraction

    CSIR Research Space (South Africa)

    Mabuza, GP

    2012-10-01

    Full Text Available the employment of other algorithms and commands so as to better present and demonstrate the obtained results. Edge detection and enhancing images for use in an iris recognition system allow for efficient recognition and extraction of iris patterns. REFERENCES... Gonzalez, R.C. and Woods, R.E. 2002. Digital Image Processing 2nd Edition, Instructor?s manual .Englewood Cliffs, Prentice Hall, pp 17-36. Proen?a, H. and Alexandre, L.A. 2007. Toward Noncooperative Iris Recognition: A classification approach using...

  11. Determination of a test section parameters for Iris nuclear reactor pressurizer

    International Nuclear Information System (INIS)

    Silva, Mario A.B. da; Lira, Carlos A.B. de O.

    2009-01-01

    An integral, modular and medium size nuclear reactor, known as IRIS, is being developed by Westinghouse and by research centers. IRIS is characterized by having most of its components inside the pressure vessel, eliminating the probability of accidents. Due to its integral configuration, there is no spray system for boron homogenization, which may cause power transients. Thus, boron mixing must be investigated. The aim of this paper is to establish the conditions under which a test section has to be built for boron dispersion analysis inside IRIS reactor pressurizer. Through Fractional Scaling Analysis, which is a new methodology of similarity, the main parameters for a test section are obtained. By combining Fractional Scaling Analysis with local scaling for the densimetric Froude number and a previously established volumetric scale factor, the values of recirculation orifices, inlet water temperature, time scale factor and recirculation flow for the test section (model) are determined so that boron distribution is well represented in IRIS reactor pressurizer (prototype). Analytical solutions were used to validate the adopted methodology and when the results simulated in the model are compared to those that characterize the prototype, the agreement for both systems is absolute. The thermal power also influences boron distribution inside the test section. This power is determined by condensation laws in the vapor region and by suitable correlations for free convection. The fractions for rising inlet recirculation water enthalpy and vapor formation are also considered. (author)

  12. New Vary-Chap Profile of the Topside Ionosphere Electron Density Distribution for use with the IRI Model and the GIRO Real-Time Data

    Science.gov (United States)

    Nsumei, Patrick; Reinisch, Bodo W.; Huang, Xueqin; Bilitza, Dieter

    2012-01-01

    A new Vary-Chap function is introduced for the empirical modeling of the electron density N(h) profile in the topside ionosphere that uses a shape function S(h) in the generalized Chapman function. The Vary-Chap profile extends the bottomside profile that is specified by the IRI model or measured by the Global Ionospheric Radio Observatory (GIRO) to the altitude of the ISIS-2 satellite. Some 80,000 topside profiles, measured by the topside sounder on the ISIS-2 satellite were analyzed, and the shape function S(h) was calculated for each profile. A parameterized function S*(h), composed of two sub-functions S1(h) and S2(h), is fitted to the measured S(h) profile using three free parameters. At altitudes just above the F2 layer peak height hmF2, the shape function S1 controls S(h), and at greater altitudes S2 controls S(h). The height of the intersection of S1 and S2 is defined as the transition height h(sub T) indicating the transition from an O(+) to an H(+)-dominated profile shape. The observed transition heights range from approx.500 km to 800 km.

  13. IRIS economics. A sensitivity review

    International Nuclear Information System (INIS)

    Miller, Keith

    2003-01-01

    IRIS (International Reactor Innovative and Secure) is a small to medium advanced light water cooled modular reactor being developed by an international consortium led by Westinghouse/BNFL. This reactor design is specifically aimed at utilities looking to install new (or replacement) nuclear capacity to match market demands, or at developing countries for their distributed power needs. To determine the optimal configuration for IRIS, analysis was undertaken to establish Generation Costs ($/MWh) and Internal Rate of Return (IRR %) to the Utility at alternative power ratings. This was then combined with global market projections for electricity demand out to 2030, segmented into key geographical regions. Finally this information is brought together to form insights, conclusions and recommendations regarding the optimal design. The resultant analysis reveals an optimum power rating for a single module of 335 MWe, with a construction period of 3 years or less and a minimum plant life of 60 years. Individual modules can be installed in a staggered fashion (3 equivalent to 1005 MWe) or built in pairs (2 sets of twin units' equivalent to 1340 MWe). Uncertainty in Market Clearing Price for electricity, Annual Operating Costs and Construction Costs primarily influence lifetime Net Present Values (NPV) and hence IRR % for Utilities. Generation Costs in addition are also influenced by Fuel Costs, Plant Output, Plant Availability and Plant Capacity Factor. Therefore for a site based on 3 single modules, located in North America, Generations Costs of 28.5 $/MWh are required to achieve an IRR of 20%, a level which enables IRIS to compete with all other forms of electricity production. Plant size is critical to commercial success. Sustained (lifetime) high factors for Plant Output, Availability and Capacity Factor are required to achieve a competitive advantage. Modularity offers Utilities the option to match their investments with market conditions, adding additional capacity as

  14. Iris image recognition wavelet filter-banks based iris feature extraction schemes

    CERN Document Server

    Rahulkar, Amol D

    2014-01-01

    This book provides the new results in wavelet filter banks based feature extraction, and the classifier in the field of iris image recognition. It provides the broad treatment on the design of separable, non-separable wavelets filter banks, and the classifier. The design techniques presented in the book are applied on iris image analysis for person authentication. This book also brings together the three strands of research (wavelets, iris image analysis, and classifier). It compares the performance of the presented techniques with state-of-the-art available schemes. This book contains the compilation of basic material on the design of wavelets that avoids reading many different books. Therefore, it provide an easier path for the new-comers, researchers to master the contents. In addition, the designed filter banks and classifier can also be effectively used than existing filter-banks in many signal processing applications like pattern classification, data-compression, watermarking, denoising etc.  that will...

  15. IRIS: Proceeding Towards the Preliminary Design

    International Nuclear Information System (INIS)

    Carelli, M.; Miller, K.; Lombardi, C.; Todreas, N.; Greenspan, E.; Ninokata, H.; Lopez, F.; Cinotti, L.; Collado, J.; Oriolo, F.; Alonso, G.; Morales, M.; Boroughs, R.; Barroso, A.; Ingersoll, D.; Cavlina, N.

    2002-01-01

    The IRIS (International Reactor Innovative and Secure) project has completed the conceptual design phase and is moving towards completion of the preliminary design, scheduled for the end of 2002. Several other papers presented in this conference provide details on major aspects of the IRIS design. The three most innovative features which uniquely characterize IRIS are, in descending order of impact: 1. Safety-by-design, which takes maximum advantage of the integral configuration to eliminate from consideration some accidents, greatly lessen the consequence of other accident scenarios and decrease their probability of occurring; 2. Optimized maintenance, where the interval between maintenance shutdowns is extended to 48 months; and 3. Long core life, of at least four years without shuffling or partial refueling. Regarding feature 1, design and analyses will be supplemented by an extensive testing campaign to verify and demonstrate the performance of the integral components, individually as well as interactive systems. Test planning is being initiated. Test results will be factored into PRA analyses under an overall risk informed regulation approach, which is planned to be used in the IRIS licensing. Pre-application activities with NRC are also scheduled to start in mid 2002. Regarding feature 2, effort is being focused on advanced online diagnostics for the integral components, first of all the steam generators, which are the most critical component; several techniques are being investigated. Finally, a four year long life core design is well underway and some of the IRIS team members are examining higher enrichment, eight to ten year life cores which could be considered for reloads. (authors)

  16. IRIS. Progress in licensing and toward deployment

    International Nuclear Information System (INIS)

    Petrovic, B.; Carelli, M.D.; Kling, C.L.; Cavlina, N.; Grgic, D.

    2006-01-01

    The International Reactor Innovative and Secure (IRIS) is an advanced, integral, light water cooled, pressurized reactor of smaller generating capacity (1000 MWt, or 335 MWe). It is being developed through a strong international partnership by a team lead by Westinghouse and including organizations from 10 countries. The main objective of the project is to offer a simple nuclear power plant with outstanding safety, attractive economics and enhanced proliferation resistance characteristics ready for deployment within the next decade. IRIS embodies the requirements set forth by the recently announced US DOE Global Nuclear Energy Partnership (GNEP) program for worldwide deployment of a smaller-scale reactors and provides a viable bridge to Generation IV reactors. IRIS is designed to address the needs of both developed and emerging markets. Its smaller power level provides deployment flexibility in larger developed markets, and makes it in particular well suited for markets with limited grids or where the annual energy demand growth is moderate. Due to its short construction time and the staggered build option, IRIS significantly reduces the required financing, improves cash flow, and provides a viable solution for economies with limited resources. While based on proven and worldwide accepted LWR technology, IRIS introduces a number of innovative solutions to simplify its design and improve safety and operational characteristics, including the integral primary system and its components, as well as the safety-by-design approach. These features will be tested and demonstrated in a testing program that has been initiated. As its centerpiece, the program will include the integral test facility. Results of this program will support licensing with the US NRC. A multinational licensing is considered to facilitate worldwide deployment. (author)

  17. Iris Matching Based on Personalized Weight Map.

    Science.gov (United States)

    Dong, Wenbo; Sun, Zhenan; Tan, Tieniu

    2011-09-01

    Iris recognition typically involves three steps, namely, iris image preprocessing, feature extraction, and feature matching. The first two steps of iris recognition have been well studied, but the last step is less addressed. Each human iris has its unique visual pattern and local image features also vary from region to region, which leads to significant differences in robustness and distinctiveness among the feature codes derived from different iris regions. However, most state-of-the-art iris recognition methods use a uniform matching strategy, where features extracted from different regions of the same person or the same region for different individuals are considered to be equally important. This paper proposes a personalized iris matching strategy using a class-specific weight map learned from the training images of the same iris class. The weight map can be updated online during the iris recognition procedure when the successfully recognized iris images are regarded as the new training data. The weight map reflects the robustness of an encoding algorithm on different iris regions by assigning an appropriate weight to each feature code for iris matching. Such a weight map trained by sufficient iris templates is convergent and robust against various noise. Extensive and comprehensive experiments demonstrate that the proposed personalized iris matching strategy achieves much better iris recognition performance than uniform strategies, especially for poor quality iris images.

  18. Iris-fixated phakic intraocular lens implantation to correct myopia and a predictive model of endothelial cell loss.

    Science.gov (United States)

    Bouheraoua, Nacim; Bonnet, Clemence; Labbé, Antoine; Sandali, Otman; Lecuen, Nicolas; Ameline, Barbara; Borderie, Vincent; Laroche, Laurent

    2015-11-01

    To report long-term results of Artisan phakic intraocular lens (pIOL) to correct myopia and to propose a model predicting endothelial cell loss after pIOL implantation. Quinze-Vingts National Ophthalmology Hospital, Paris, France. Retrospective, interventional case series. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and central endothelial cell count (ECC) were determined before and at yearly intervals up to 5 years after pIOL implantation. Linear model analysis was performed to present a model that describes endothelial cell loss as a linear decrease and an additional decrease depending on postoperative loss. A total of 49 patients (68 eyes) implanted with pIOLs from January 2000 to January 2009 were evaluated. The mean preoperative and final spherical equivalent (SE) were -13 ± 4.10 and -0.75 ± 0.74 diopters (D), respectively. The mean preoperative and final central ECC were 2629 ± 366 and 2250 ± 454 cells/mm(2), respectively. There were no intraoperative complications for any of the eyes. One eye required surgery for repositioning the pIOL, and 1 eye required pIOL exchange for postoperative refractive error. The model predicted that for patients with preoperative ECC of 3000, 2500, and 2000 cells/mm(2), a critical ECC of 1500 cells/mm(2) will be reached at 39, 28, and 15 years after implantation, respectively. Implantation of the pIOL was an effective and stable procedure after 5 years of follow-up. The presented model predicted EC loss after pIOL implantation, which can assist ophthalmologists in patient selection and follow-up. The authors report no conflict of interest. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. Micropropagation of Iris sp.

    Science.gov (United States)

    Jevremović, Slađana; Jeknić, Zoran; Subotić, Angelina

    2013-01-01

    Irises are perennial plants widely used as ornamental garden plants or cut flowers. Some species accumulate secondary metabolites, making them highly valuable to the pharmaceutical and perfume industries. Micropropagation of irises has successfully been accomplished by culturing zygotic embryos, different flower parts, and leaf base tissues as starting explants. Plantlets are regenerated via somatic embryogenesis, organogenesis, or both processes at the same time depending on media composition and plant species. A large number of uniform plants are produced by somatic embryogenesis, however, some species have decreased morphogenetic potential overtime. Shoot cultures obtained by organogenesis can be multiplied for many years. Somatic embryogenic tissue can be reestablished from leaf bases of in vitro-grown shoots. The highest number of plants can be obtained by cell suspension cultures. This chapter describes effective in vitro plant regeneration protocols for Iris species from different types of explants by somatic embryogenesis and/or organogenesis suitable for the mass propagation of ornamental and pharmaceutical irises.

  20. Bartus Iris biometrics

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, R.; Grace, W.

    1996-07-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). We won a 1994 R&D 100 Award for inventing the Bartas Iris Verification System. The system has been delivered to a sponsor and is no longer available to us. This technology can verify the identity of a person for purposes of access control, national security, law enforcement, forensics, counter-terrorism, and medical, financial, or scholastic records. The technique is non-invasive, psychologically acceptable, works in real-time, and obtains more biometric data than any other biometric except DNA analysis. This project sought to develop a new, second-generation prototype instrument.

  1. Iris recognition based on robust principal component analysis

    Science.gov (United States)

    Karn, Pradeep; He, Xiao Hai; Yang, Shuai; Wu, Xiao Hong

    2014-11-01

    Iris images acquired under different conditions often suffer from blur, occlusion due to eyelids and eyelashes, specular reflection, and other artifacts. Existing iris recognition systems do not perform well on these types of images. To overcome these problems, we propose an iris recognition method based on robust principal component analysis. The proposed method decomposes all training images into a low-rank matrix and a sparse error matrix, where the low-rank matrix is used for feature extraction. The sparsity concentration index approach is then applied to validate the recognition result. Experimental results using CASIA V4 and IIT Delhi V1iris image databases showed that the proposed method achieved competitive performances in both recognition accuracy and computational efficiency.

  2. [Phytoremediation of Petroleum Contaminated Soils with Iris pseudacorus L. and the Metabolic Analysis in Roots].

    Science.gov (United States)

    Wang, Ya-nan; Cheng, Li-juan; Zhou, Qi-xing

    2016-04-15

    In this study, we performed a greenhouse pot-culture experiment to investigate the potential of a wild ornamental plant Iris pseudacorus L. in remediating petroleum contaminated soils from the Dagang Oilfield in Tianjin, China. The results suggested that Iris pseudacorus L. had great resistance to ≤ 40,000 mg · kg(⁻¹ of total petroleum hydrocarbons (TPHs). The removal rate of TPHs with concentrations of 10,000 mg · kg⁻¹, 20,000 mg · kg⁻¹ and 40,000 mg · kg⁻¹ in soils by Iris pseudacorus L. was 42.1%, 33.1% 31.2%, respectively, much higher than those in the corresponding controls (31.8%, 21.3% 11.9%, respectively) (P 1.2) with the root specific surface area from the PLS-DA model analysis, including ethanedioic acid, lactic acid, 2-butenedioic acid, phosphate and propanedioic acid, were positively correlated with the root specific surface area, but the others, gluconic acid, uridine, butanoic acid, maltose, 9,12-octadecadienoic acid, phenylalanine, were negatively correlated with it. In conclusion, using Iris pseudacorus L. to remediate petroleum contaminated soils is feasible, and the metabolic analysis in roots is useful to better understand the metabolic response of plants exposure to petroleum contaminated soils, and then reveals its remediated mechanisms.

  3. Comparison of ionospheric F2 peak parameters foF2 and hmF2 with IRI2001 at Hainan

    Science.gov (United States)

    Wang, X.; Shi, J. K.; Wang, G. J.; Gong, Y.

    2009-06-01

    Monthly median values of foF2, hmF2 and M(3000)F2 parameters, with quarter-hourly time interval resolution for the diurnal variation, obtained with DPS4 digisonde at Hainan (19.5°N, 109.1°E; Geomagnetic coordinates: 178.95°E, 8.1°N) are used to investigate the low-latitude ionospheric variations and comparisons with the International Reference Ionosphere (IRI) model predictions. The data used for the present study covers the period from February 2002 to April 2007, which is characterized by a wide range of solar activity, ranging from high solar activity (2002) to low solar activity (2007). The results show that (1) Generally, IRI predictions follow well the diurnal and seasonal variation patterns of the experimental values of foF2, especially in the summer of 2002. However, there are systematic deviation between experimental values and IRI predictions with either CCIR or URSI coefficients. Generally IRI model greatly underestimate the values of foF2 from about noon to sunrise of next day, especially in the afternoon, and slightly overestimate them from sunrise to about noon. It seems that there are bigger deviations between IRI Model predictions and the experimental observations for the moderate solar activity. (2) Generally the IRI-predicted hmF2 values using CCIR M(3000)F2 option shows a poor agreement with the experimental results, but there is a relatively good agreement in summer at low solar activity. The deviation between the IRI-predicted hmF2 using CCIR M(3000)F2 and observed hmF2 is bigger from noon to sunset and around sunrise especially at high solar activity. The occurrence time of hmF2 peak (about 1200 LT) of the IRI model predictions is earlier than that of observations (around 1500 LT). The agreement between the IRI hmF2 obtained with the measured M(3000)F2 and the observed hmF2 is very good except that IRI overestimates slightly hmF2 in the daytime in summer at high solar activity and underestimates it in the nighttime with lower values near

  4. Presentation Attack Detection for Iris Recognition System Using NIR Camera Sensor

    Science.gov (United States)

    Nguyen, Dat Tien; Baek, Na Rae; Pham, Tuyen Danh; Park, Kang Ryoung

    2018-01-01

    Among biometric recognition systems such as fingerprint, finger-vein, or face, the iris recognition system has proven to be effective for achieving a high recognition accuracy and security level. However, several recent studies have indicated that an iris recognition system can be fooled by using presentation attack images that are recaptured using high-quality printed images or by contact lenses with printed iris patterns. As a result, this potential threat can reduce the security level of an iris recognition system. In this study, we propose a new presentation attack detection (PAD) method for an iris recognition system (iPAD) using a near infrared light (NIR) camera image. To detect presentation attack images, we first localized the iris region of the input iris image using circular edge detection (CED). Based on the result of iris localization, we extracted the image features using deep learning-based and handcrafted-based methods. The input iris images were then classified into real and presentation attack categories using support vector machines (SVM). Through extensive experiments with two public datasets, we show that our proposed method effectively solves the iris recognition presentation attack detection problem and produces detection accuracy superior to previous studies. PMID:29695113

  5. Presentation Attack Detection for Iris Recognition System Using NIR Camera Sensor

    Directory of Open Access Journals (Sweden)

    Dat Tien Nguyen

    2018-04-01

    Full Text Available Among biometric recognition systems such as fingerprint, finger-vein, or face, the iris recognition system has proven to be effective for achieving a high recognition accuracy and security level. However, several recent studies have indicated that an iris recognition system can be fooled by using presentation attack images that are recaptured using high-quality printed images or by contact lenses with printed iris patterns. As a result, this potential threat can reduce the security level of an iris recognition system. In this study, we propose a new presentation attack detection (PAD method for an iris recognition system (iPAD using a near infrared light (NIR camera image. To detect presentation attack images, we first localized the iris region of the input iris image using circular edge detection (CED. Based on the result of iris localization, we extracted the image features using deep learning-based and handcrafted-based methods. The input iris images were then classified into real and presentation attack categories using support vector machines (SVM. Through extensive experiments with two public datasets, we show that our proposed method effectively solves the iris recognition presentation attack detection problem and produces detection accuracy superior to previous studies.

  6. Novel approaches to improve iris recognition system performance based on local quality evaluation and feature fusion.

    Science.gov (United States)

    Chen, Ying; Liu, Yuanning; Zhu, Xiaodong; Chen, Huiling; He, Fei; Pang, Yutong

    2014-01-01

    For building a new iris template, this paper proposes a strategy to fuse different portions of iris based on machine learning method to evaluate local quality of iris. There are three novelties compared to previous work. Firstly, the normalized segmented iris is divided into multitracks and then each track is estimated individually to analyze the recognition accuracy rate (RAR). Secondly, six local quality evaluation parameters are adopted to analyze texture information of each track. Besides, particle swarm optimization (PSO) is employed to get the weights of these evaluation parameters and corresponding weighted coefficients of different tracks. Finally, all tracks' information is fused according to the weights of different tracks. The experimental results based on subsets of three public and one private iris image databases demonstrate three contributions of this paper. (1) Our experimental results prove that partial iris image cannot completely replace the entire iris image for iris recognition system in several ways. (2) The proposed quality evaluation algorithm is a self-adaptive algorithm, and it can automatically optimize the parameters according to iris image samples' own characteristics. (3) Our feature information fusion strategy can effectively improve the performance of iris recognition system.

  7. Presentation Attack Detection for Iris Recognition System Using NIR Camera Sensor.

    Science.gov (United States)

    Nguyen, Dat Tien; Baek, Na Rae; Pham, Tuyen Danh; Park, Kang Ryoung

    2018-04-24

    Among biometric recognition systems such as fingerprint, finger-vein, or face, the iris recognition system has proven to be effective for achieving a high recognition accuracy and security level. However, several recent studies have indicated that an iris recognition system can be fooled by using presentation attack images that are recaptured using high-quality printed images or by contact lenses with printed iris patterns. As a result, this potential threat can reduce the security level of an iris recognition system. In this study, we propose a new presentation attack detection (PAD) method for an iris recognition system (iPAD) using a near infrared light (NIR) camera image. To detect presentation attack images, we first localized the iris region of the input iris image using circular edge detection (CED). Based on the result of iris localization, we extracted the image features using deep learning-based and handcrafted-based methods. The input iris images were then classified into real and presentation attack categories using support vector machines (SVM). Through extensive experiments with two public datasets, we show that our proposed method effectively solves the iris recognition presentation attack detection problem and produces detection accuracy superior to previous studies.

  8. Academy Distance Learning Tools (IRIS) -

    Data.gov (United States)

    Department of Transportation — IRIS is a suite of front-end web applications utilizing a centralized back-end Oracle database. The system fully supports the FAA Academy's Distance Learning Program...

  9. Iris Murdoch armastusest / Udo uibo

    Index Scriptorium Estoniae

    Uibo, Udo, 1956-

    2010-01-01

    Londoni Kingstoni ülikool omandas 50 000 naesterlingi eest 164 Iris Murdochi kirja prantsuse kirjanikule, keeleeksperimentaatorile Raymond Quenaule, millest selgub Murdochi ühepoolne ning vastamata jäänud tunne Quenau suhtes.

  10. Integrated Risk Information System (IRIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — EPA?s Integrated Risk Information System (IRIS) is a compilation of electronic reports on specific substances found in the environment and their potential to cause...

  11. Case study of ISWI in Vietnam: A comparison of ionospheric parameters observed over Ho Chi Minh with IRI predictions

    Science.gov (United States)

    Lan, Hoang Thai; Tam, Dao Ngoc Hanh

    2014-01-01

    For the contribution of Vietnam to ISWI activities, there are 3 GPS receivers, 3 Ionosondes, 1 AWESOME and 1 MAGDAS operating in Vietnam. With a special geographical position stretching from the north tropic to the magnetic equator, Vietnam is an interesting area to supplement the data for the Global Space Weather Model. The Ionosphere is an important indicator of Space Weather and the International Reference Ionosphere (IRI) model has become widely accepted. The first task of ionospheric science in a new location is often comparing the observed data with IRI. This paper presents the results of comparisons of the foF2 and TEC observed over Ho Chi Minh City (10.51 N, 106.33 E) with the values calculated according to the IRI-2007 in order to evaluate the applicability of the model in forecasting for the equatorial region of Vietnam. We compare the critical frequency of layer F (foF2) and Total Electron Content (TEC) values for two phases of solar activity. The results show very good diurnal correlations between the observed foF2 and TEC with IRI values in the decreasing solar activity period 2003 ± 2006 (the deviation 40. This is a note for correction IRI model applying for Vietnam. The comparison of the TEC shows that the correlation between GPS-TEC and IRI-TEC generally was good with coefficients k > 0.8 and R > 0.9 for the period 2006 - 2010. The worst relationship were March, April, September, October, November and December 2011, corresponding to periods when the TEC gradients are highest. The phenomenon of decline in the TEC at noon over Ho Chi Minh City observed pretty weak. This phenomenon appeared only in a few months from April to September, when the ionization is high. In the period from 0 to 5 am local time, the average minimum GPS-TEC observed over Ho Chi Minh City is about 3 tecu, while the IRI-TEC value is ~ 0.3. Thus, the IRI-TEC values should be recalibrated.

  12. Comparison and evaluation of datasets for off-angle iris recognition

    Science.gov (United States)

    Kurtuncu, Osman M.; Cerme, Gamze N.; Karakaya, Mahmut

    2016-05-01

    In this paper, we investigated the publicly available iris recognition datasets and their data capture procedures in order to determine if they are suitable for the stand-off iris recognition research. Majority of the iris recognition datasets include only frontal iris images. Even if a few datasets include off-angle iris images, the frontal and off-angle iris images are not captured at the same time. The comparison of the frontal and off-angle iris images shows not only differences in the gaze angle but also change in pupil dilation and accommodation as well. In order to isolate the effect of the gaze angle from other challenging issues including dilation and accommodation, the frontal and off-angle iris images are supposed to be captured at the same time by using two different cameras. Therefore, we developed an iris image acquisition platform by using two cameras in this work where one camera captures frontal iris image and the other one captures iris images from off-angle. Based on the comparison of Hamming distance between frontal and off-angle iris images captured with the two-camera- setup and one-camera-setup, we observed that Hamming distance in two-camera-setup is less than one-camera-setup ranging from 0.05 to 0.001. These results show that in order to have accurate results in the off-angle iris recognition research, two-camera-setup is necessary in order to distinguish the challenging issues from each other.

  13. Iris Location Algorithm Based on the CANNY Operator and Gradient Hough Transform

    Science.gov (United States)

    Zhong, L. H.; Meng, K.; Wang, Y.; Dai, Z. Q.; Li, S.

    2017-12-01

    In the iris recognition system, the accuracy of the localization of the inner and outer edges of the iris directly affects the performance of the recognition system, so iris localization has important research meaning. Our iris data contain eyelid, eyelashes, light spot and other noise, even the gray transformation of the images is not obvious, so the general methods of iris location are unable to realize the iris location. The method of the iris location based on Canny operator and gradient Hough transform is proposed. Firstly, the images are pre-processed; then, calculating the gradient information of images, the inner and outer edges of iris are coarse positioned using Canny operator; finally, according to the gradient Hough transform to realize precise localization of the inner and outer edge of iris. The experimental results show that our algorithm can achieve the localization of the inner and outer edges of the iris well, and the algorithm has strong anti-interference ability, can greatly reduce the location time and has higher accuracy and stability.

  14. Towards online iris and periocular recognition under relaxed imaging constraints.

    Science.gov (United States)

    Tan, Chun-Wei; Kumar, Ajay

    2013-10-01

    Online iris recognition using distantly acquired images in a less imaging constrained environment requires the development of a efficient iris segmentation approach and recognition strategy that can exploit multiple features available for the potential identification. This paper presents an effective solution toward addressing such a problem. The developed iris segmentation approach exploits a random walker algorithm to efficiently estimate coarsely segmented iris images. These coarsely segmented iris images are postprocessed using a sequence of operations that can effectively improve the segmentation accuracy. The robustness of the proposed iris segmentation approach is ascertained by providing comparison with other state-of-the-art algorithms using publicly available UBIRIS.v2, FRGC, and CASIA.v4-distance databases. Our experimental results achieve improvement of 9.5%, 4.3%, and 25.7% in the average segmentation accuracy, respectively, for the UBIRIS.v2, FRGC, and CASIA.v4-distance databases, as compared with most competing approaches. We also exploit the simultaneously extracted periocular features to achieve significant performance improvement. The joint segmentation and combination strategy suggest promising results and achieve average improvement of 132.3%, 7.45%, and 17.5% in the recognition performance, respectively, from the UBIRIS.v2, FRGC, and CASIA.v4-distance databases, as compared with the related competing approaches.

  15. Frontal view reconstruction for iris recognition

    Science.gov (United States)

    Santos-Villalobos, Hector J; Bolme, David S; Boehnen, Chris Bensing

    2015-02-17

    Iris recognition can be accomplished for a wide variety of eye images by correcting input images with an off-angle gaze. A variety of techniques, from limbus modeling, corneal refraction modeling, optical flows, and genetic algorithms can be used. A variety of techniques, including aspherical eye modeling, corneal refraction modeling, ray tracing, and the like can be employed. Precomputed transforms can enhance performance for use in commercial applications. With application of the technologies, images with significantly unfavorable gaze angles can be successfully recognized.

  16. Aqueous humor tyrosinase activity is indicative of iris melanocyte toxicity.

    Science.gov (United States)

    Mahanty, Sarmistha; Kawali, Ankush A; Dakappa, Shruthi Shirur; Mahendradas, Padmamalini; Kurian, Mathew; Kharbanda, Varun; Shetty, Rohit; Setty, Subba Rao Gangi

    2017-09-01

    TYR enzyme, thus reflecting its toxicity to iris melanocytes and corresponding to its activity in the aqueous humor. Intriguingly, none of these patients developed any clinically appreciable ocular side effects characteristic of BAIT or BADI. Overall, our results suggest that topical antibiotics cause different levels of iris melanocyte toxicity, releasing dispersed pigments into the aqueous humor, which can be measured through TYR enzyme activity. Hence, we conclude that topical FQLs may cause subclinical toxicity to the iris melanocytes but may not be the sole cause of the development of BAIT or BADI. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Evaluation of Genetic Diversity of Iris Genotypes (Iris spp Using ISSR

    Directory of Open Access Journals (Sweden)

    seyedeh zeinab attari

    2017-02-01

    and qualified using agarose gel electrophoresis. A total of 16 primers were initially screened against two plants selected from different regions and finally six primers for final analysis was selected based on consistent (CA8G ،(CT8RG ،(TC8C ،(TG8G ، (AC8YG and (AG8YT, strong amplification products, production of polymorph, reproducible fragments between replicate Polymerase Chain Reaction (PCR. The ISSR amplification reactions contained 30-50 ηg of genomic DNA, 2.5 μL 1 × buffer, 2 mM MgCl2, 200 μM of each dNTP (Fermentas, 10 μM primers and 0.2 U Taq DNA polymerase (Fermentas, with the final volume adjusted to 25μL with H2O bidest. ISSR reaction products were separated on 1.5% horizontal agarose gels, in TBE buffer and visualized under ultraviolet light after staining in 0.5μg/mL ethidium bromide. Digital photo was taken with gel documentation system. The 100 bp DNA ladder plus molecular weight marker was used to compare the molecular weight of amplified products. Amplified products were scored for the presence (1 or absence (0 of bands and binary matrices were assembled for the ISSR markers. The binary matrices were subjected to statistical analyses using NTSYS-pc software version 2.02. Results and Discussion: Six ISSR primers produced 126 bands across the 16 genotypes, of which 119 were polymorphic. The number of amplified fragments varied from 16 [primer (CA8G] to 24 [primer (TC8C and (AC8YG] across the genotypes. The average polymorphic bands per primer were 19.4. The percentage of polymorphism for primers ranged from 76 to 100, with an average of 94.4.The amplified bands genotypes related to a species the same banding pattern was observed but there was lower similarity between the species. Our data indicated that ISSR technology can detect considerable polymorphisms (76.4 % in our genotypes, suggesting that it will be useful in characterization and fingerprinting of Iris germplasm. The results of this study also provide fundamental evidence

  18. International Roughness Index (IRI) measurement using Hilbert-Huang transform

    Science.gov (United States)

    Zhang, Wenjin; Wang, Ming L.

    2018-03-01

    International Roughness Index (IRI) is an important metric to measure condition of roadways. This index is usually used to justify the maintenance priority and scheduling for roadways. Various inspection methods and algorithms are used to assess this index through the use of road profiles. This study proposes to calculate IRI values using Hilbert-Huang Transform (HHT) algorithm. In particular, road profile data is provided using surface radar attached to a vehicle driving at highway speed. Hilbert-Huang transform (HHT) is used in this study because of its superior properties for nonstationary and nonlinear data. Empirical mode decomposition (EMD) processes the raw data into a set of intrinsic mode functions (IMFs), representing various dominating frequencies. These various frequencies represent noises from the body of the vehicle, sensor location, and the excitation induced by nature frequency of the vehicle, etc. IRI calculation can be achieved by eliminating noises that are not associated with the road profile including vehicle inertia effect. The resulting IRI values are compared favorably to the field IRI values, where the filtered IMFs captures the most characteristics of road profile while eliminating noises from the vehicle and the vehicle inertia effect. Therefore, HHT is an effect method for road profile analysis and for IRI measurement. Furthermore, the application of HHT method has the potential to eliminate the use of accelerometers attached to the vehicle as part of the displacement measurement used to offset the inertia effect.

  19. Cosmetic Detection Framework for Face and Iris Biometrics

    Directory of Open Access Journals (Sweden)

    Omid Sharifi

    2018-04-01

    Full Text Available Cosmetics pose challenges to the recognition performance of face and iris biometric systems due to its ability to alter natural facial and iris patterns. Facial makeup and iris contact lens are considered to be commonly applied cosmetics for the face and iris in this study. The present work aims to present a novel solution for the detection of cosmetics in both face and iris biometrics by the fusion of texture, shape and color descriptors of images. The proposed cosmetic detection scheme combines the microtexton information from the local primitives of texture descriptors with the color spaces achieved from overlapped blocks in order to achieve better detection of spots, flat areas, edges, edge ends, curves, appearance and colors. The proposed cosmetic detection scheme was applied to the YMU YouTube makeup database (YMD facial makeup database and IIIT-Delhi Contact Lens iris database. The results demonstrate that the proposed cosmetic detection scheme is significantly improved compared to the other schemes implemented in this study.

  20. SINGLE FRAME SUPER RESOLUTION OF NONCOOPERATIVE IRIS IMAGES

    Directory of Open Access Journals (Sweden)

    Anand Deshpande

    2016-11-01

    Full Text Available Image super-resolution, a process to enhance image resolution, has important applications in biometrics, satellite imaging, high definition television, medical imaging, etc. The long range captured iris identification systems often suffer from low resolution and meager focus of the captured iris images. These degrade the iris recognition performance. This paper proposes enhanced iterated back projection (EIBP method to super resolute the long range captured iris polar images. The performance of proposed method is tested and analyzed on CASIA long range iris database by comparing peak signal to noise ratio (PSNR and structural similarity index (SSIM with state-of-the-art super resolution (SR algorithms. It is further analyzed by increasing the up-sampling factor. Performance analysis shows that the proposed method is superior to state-of-the-art algorithms, the peak signal-to-noise ratio improved about 0.1-1.5 dB. The results demonstrate that the proposed method is well suited to super resolve the iris polar images captured at a long distance

  1. A multi-approach feature extractions for iris recognition

    Science.gov (United States)

    Sanpachai, H.; Settapong, M.

    2014-04-01

    Biometrics is a promising technique that is used to identify individual traits and characteristics. Iris recognition is one of the most reliable biometric methods. As iris texture and color is fully developed within a year of birth, it remains unchanged throughout a person's life. Contrary to fingerprint, which can be altered due to several aspects including accidental damage, dry or oily skin and dust. Although iris recognition has been studied for more than a decade, there are limited commercial products available due to its arduous requirement such as camera resolution, hardware size, expensive equipment and computational complexity. However, at the present time, technology has overcome these obstacles. Iris recognition can be done through several sequential steps which include pre-processing, features extractions, post-processing, and matching stage. In this paper, we adopted the directional high-low pass filter for feature extraction. A box-counting fractal dimension and Iris code have been proposed as feature representations. Our approach has been tested on CASIA Iris Image database and the results are considered successful.

  2. Proceedings of the IRI Task Force Activity 2001

    International Nuclear Information System (INIS)

    Radicella, S.M.

    2002-08-01

    This ICTP Internal Report contains the list of papers presented, activity report and the write up of a number of presentations delivered during the International Reference Ionosphere (IRI) Task Force Activity 2001 which took place at the Abdus Salam ICTP during May 2001, particularly centred in the week from 21-25 May. The 2001 Task Force Activity is the eighth successful encounter of specialists organized by the URSI-Cospar IRI Working Group and the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics of Trieste, Italy. This project continues the IRI Task Force Activities at the Abdus Salam International Centre for Theoretical Physics (ICTP) in Trieste, Italy. The primary focus of this activity was the development of a specification model for ionospheric variability. Such a model is high on the wish list of users of ionospheric models. Climatological models like IRI provide monthly mean values of ionospheric parameters. Understandably a satellite designer or operator needs to know not only the monthly average conditions but also the expected deviations from these mean values. The main discussions and presentations took place during the week 21-25 May. The format was similar to last year's activity with presentations and round-table discussions in the morning and follow-on work in small subgroups in front of computer terminals in the afternoon. This Proceedings contains also four papers of the previous IRI Task Force Activity which were omitted

  3. Information fusion in personal biometric authentication based on the iris pattern

    International Nuclear Information System (INIS)

    Wang, Fenghua; Han, Jiuqiang

    2009-01-01

    Information fusion in biometrics has received considerable attention. This paper focuses on the application of information fusion techniques in iris recognition. To improve the reliability and accuracy of personal identification based on the iris pattern, this paper proposes the schemes of multialgorithmic fusion and multiinstance fusion. Multialgorithmic fusion integrates the improved phase algorithm and the DCT-based algorithm, and multiinstance fusion combines information from the left iris and the right iris of an individual. Both multialgorithmic fusion and multiinstance fusion are carried out at the matching score level and the support vector machine (SVM)-based fusion rule is utilized to generate fused scores for final decision. The experimental results on the noisy iris database UBIRIS demonstrate that the proposed fusion schemes can perform better than the single recognition systems, and further prove that information fusion techniques are feasible and effective to improve the accuracy and robustness of iris recognition especially under noisy conditions

  4. Optimal Face-Iris Multimodal Fusion Scheme

    Directory of Open Access Journals (Sweden)

    Omid Sharifi

    2016-06-01

    Full Text Available Multimodal biometric systems are considered a way to minimize the limitations raised by single traits. This paper proposes new schemes based on score level, feature level and decision level fusion to efficiently fuse face and iris modalities. Log-Gabor transformation is applied as the feature extraction method on face and iris modalities. At each level of fusion, different schemes are proposed to improve the recognition performance and, finally, a combination of schemes at different fusion levels constructs an optimized and robust scheme. In this study, CASIA Iris Distance database is used to examine the robustness of all unimodal and multimodal schemes. In addition, Backtracking Search Algorithm (BSA, a novel population-based iterative evolutionary algorithm, is applied to improve the recognition accuracy of schemes by reducing the number of features and selecting the optimized weights for feature level and score level fusion, respectively. Experimental results on verification rates demonstrate a significant improvement of proposed fusion schemes over unimodal and multimodal fusion methods.

  5. IRIS pre-application licensing

    International Nuclear Information System (INIS)

    Carelli, Mario D.; Kling, Charles L.; Ritterbusch, Stanley E.

    2003-01-01

    This paper presents the approach to pre-application licensing by the International Reactor Innovative and Secure (IRIS), and advanced, integral reactor design with a thermal power of 1000 MW. The rationale for the pre-application licensing is discussed. Since IRIS technology is based on proven LWR experience, the project will rely on AP600/AP1000 precedent and will focus during the pre-application on long lead and novel items. A discussion of the evolution of the project to significantly reduce licensing issues is provided, followed by a summary of the IRIS safety-by-design which provides a formidable first step in the Defense in Depth approach. The effects of the safety-by-design, as well as of passive systems, on the IRIS safety will be investigated in a proposed testing program that will be reviewed by NRC during the pre-application. Documentation to be provided to NRC is discussed. Early design analyses indicate that the benefits of the IRIS safety-by-design approach are so significant that the basic premise of current emergency planning regulations (i.e., likelihood of core damage) will be reduced to the extent that special emergency response planning beyond the exclusion area boundary may not be needed. How this very significant outcome can be effected through a highly risk-informed licensing is discussed. (author)

  6. IrisDenseNet: Robust Iris Segmentation Using Densely Connected Fully Convolutional Networks in the Images by Visible Light and Near-Infrared Light Camera Sensors.

    Science.gov (United States)

    Arsalan, Muhammad; Naqvi, Rizwan Ali; Kim, Dong Seop; Nguyen, Phong Ha; Owais, Muhammad; Park, Kang Ryoung

    2018-05-10

    The recent advancements in computer vision have opened new horizons for deploying biometric recognition algorithms in mobile and handheld devices. Similarly, iris recognition is now much needed in unconstraint scenarios with accuracy. These environments make the acquired iris image exhibit occlusion, low resolution, blur, unusual glint, ghost effect, and off-angles. The prevailing segmentation algorithms cannot cope with these constraints. In addition, owing to the unavailability of near-infrared (NIR) light, iris recognition in visible light environment makes the iris segmentation challenging with the noise of visible light. Deep learning with convolutional neural networks (CNN) has brought a considerable breakthrough in various applications. To address the iris segmentation issues in challenging situations by visible light and near-infrared light camera sensors, this paper proposes a densely connected fully convolutional network (IrisDenseNet), which can determine the true iris boundary even with inferior-quality images by using better information gradient flow between the dense blocks. In the experiments conducted, five datasets of visible light and NIR environments were used. For visible light environment, noisy iris challenge evaluation part-II (NICE-II selected from UBIRIS.v2 database) and mobile iris challenge evaluation (MICHE-I) datasets were used. For NIR environment, the institute of automation, Chinese academy of sciences (CASIA) v4.0 interval, CASIA v4.0 distance, and IIT Delhi v1.0 iris datasets were used. Experimental results showed the optimal segmentation of the proposed IrisDenseNet and its excellent performance over existing algorithms for all five datasets.

  7. IrisDenseNet: Robust Iris Segmentation Using Densely Connected Fully Convolutional Networks in the Images by Visible Light and Near-Infrared Light Camera Sensors

    Directory of Open Access Journals (Sweden)

    Muhammad Arsalan

    2018-05-01

    Full Text Available The recent advancements in computer vision have opened new horizons for deploying biometric recognition algorithms in mobile and handheld devices. Similarly, iris recognition is now much needed in unconstraint scenarios with accuracy. These environments make the acquired iris image exhibit occlusion, low resolution, blur, unusual glint, ghost effect, and off-angles. The prevailing segmentation algorithms cannot cope with these constraints. In addition, owing to the unavailability of near-infrared (NIR light, iris recognition in visible light environment makes the iris segmentation challenging with the noise of visible light. Deep learning with convolutional neural networks (CNN has brought a considerable breakthrough in various applications. To address the iris segmentation issues in challenging situations by visible light and near-infrared light camera sensors, this paper proposes a densely connected fully convolutional network (IrisDenseNet, which can determine the true iris boundary even with inferior-quality images by using better information gradient flow between the dense blocks. In the experiments conducted, five datasets of visible light and NIR environments were used. For visible light environment, noisy iris challenge evaluation part-II (NICE-II selected from UBIRIS.v2 database and mobile iris challenge evaluation (MICHE-I datasets were used. For NIR environment, the institute of automation, Chinese academy of sciences (CASIA v4.0 interval, CASIA v4.0 distance, and IIT Delhi v1.0 iris datasets were used. Experimental results showed the optimal segmentation of the proposed IrisDenseNet and its excellent performance over existing algorithms for all five datasets.

  8. 77 FR 31869 - Iris Lacustris (Dwarf Lake Iris); Draft Recovery Plan for Review and Comment

    Science.gov (United States)

    2012-05-30

    ...-FF03E00000] Iris Lacustris (Dwarf Lake Iris); Draft Recovery Plan for Review and Comment AGENCY: Fish and... Service (Service) announces availability for public review of the draft recovery plan for the Iris lacustris (dwarf lake iris), a species that is federally listed as threatened under the Endangered Species...

  9. IRIS Toxicological Review of Acrolein (2003 Final)

    Science.gov (United States)

    EPA announced the release of the final report, Toxicological Review of Acrolein: in support of the Integrated Risk Information System (IRIS). The updated Summary for Acrolein and accompanying toxicological review have been added to the IRIS Database.

  10. IRIS Toxicological Review of Chloroform (Final Report)

    Science.gov (United States)

    EPA is announcing the release of the final report, Toxicological Review of Chloroform: in support of the Integrated Risk Information System (IRIS). The updated Summary for Chloroform and accompanying Quickview have also been added to the IRIS Database.

  11. PLATEAU IRIS SYNDROME--CASE SERIES.

    Science.gov (United States)

    Feraru, Crenguta Ioana; Pantalon, Anca Delia; Chiselita, Dorin; Branisteanu, Daniel

    2015-01-01

    Plateau iris is characterized by closing the anterior chamber angle due to a large ciliary body or due to its anterior insertion that alters the position of iris periphery in respect to the trabecular meshwork. There are two aspects that need to be differentiated: plateau iris configuration and plateau iris syndrome. The first describes a situation when the iris root is flat and the anterior chamber is not shallow, the latter refers to a post laser iridotomy condition in which a patent iridotomy has removed the relative pupillary block, but goniscopically confirmed angle closure recurs without central shallowing of the anterior chamber. Isolated plateau iris syndrome is rare compared to plateau iris configuration. We hereby present two case reports of plateau iris syndrome in young patients who came to an ophthalmologic consult by chance.

  12. IRIS and the National Research Council (NRC)

    Science.gov (United States)

    Since the 2011 National Academies’ National Research Council (NRC) review of the IRIS Program's assessment of Formaldehyde, EPA and NRC have had an ongoing relationship into the improvements of developing the IRIS Assessments.

  13. Quality assessment for online iris images

    CSIR Research Space (South Africa)

    Makinana, S

    2015-01-01

    Full Text Available Iris recognition systems have attracted much attention for their uniqueness, stability and reliability. However, performance of this system depends on quality of iris image. Therefore there is a need to select good quality images before features can...

  14. A new global empirical model of the electron temperature with the inclusion of the solar activity variations for IRI

    Czech Academy of Sciences Publication Activity Database

    Truhlík, Vladimír; Bilitza, D.; Třísková, Ludmila

    2012-01-01

    Roč. 64, č. 6 (2012), s. 531-543 ISSN 1343-8832 R&D Projects: GA AV ČR IAA300420603; GA ČR GAP209/10/2086 Grant - others: NASA (US) NNH06CD17C. Institutional support: RVO:68378289 Keywords : Electron temperature * ionosphere * plasmasphere * empirical models * International Reference Ionosphere Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.921, year: 2012 http://www.terrapub.co.jp/journals/EPS/abstract/6406/64060531.html

  15. Iris small break loca phenomena identification and ranking table (PIRT)

    International Nuclear Information System (INIS)

    Larson, T.K.; Moody, F.J.; Wilson, G.E.; Brown, W.L.; Frepoli, C.; Hartz, J.; Woods, B.G.; Oriani, L.

    2007-01-01

    The international reactor innovative and secure (IRIS) is a modular pressurized water reactor with an integral configuration (all primary system components - reactor core, internals, pumps, steam generators, pressurizer, and control rod drive mechanisms - are inside the reactor vessel). The IRIS plant conceptual design was completed in 2001 and the preliminary design is currently underway. The pre-application licensing process with the United States Nuclear Regulatory Commission (USNRC) started in October 2002. The first line of defense in IRIS is to eliminate event initiators that could potentially lead to core damage. If it is not possible to eliminate certain accidents altogether, then the design inherently reduces their consequences and/or decreases their probability of occurring. One of the most obvious advantages of the IRIS Safety-by-Design TM approach is the elimination of large break loss-of-coolant accidents (LBLOCAs), since no large primary penetrations of the reactor vessel or large loop piping exist. While the IRIS Safety-by-Design TM approach is a logical step in the effort to produce advanced reactors, the desired advances in safety must still be demonstrated in the licensing arena. With the elimination of LBLOCA, an important next consideration is to show the IRIS design fulfills the promise of increased safety also for small break LOCAs (SBLOCAs). Accordingly, the SBLOCA phenomena identification and ranking table (PIRT) project was established. The primary objective of the IRIS SBLOCA PIRT project was to identify the relative importance of phenomena in the IRIS response to SBLOCAs. This relative importance, coupled with the current relative state of knowledge for the phenomena, provides a framework for the planning of the continued experimental and analytical efforts. To satisfy the SBLOCA PIRT project objectives, Westinghouse organized an expert panel whose members were carefully selected to insure that the PIRT results reflect internationally

  16. Ekspert i undervisning - IRIS Connect

    DEFF Research Database (Denmark)

    Wullum, Annemette Heine; Eriksen, Frits Hedegaard

    Ekspert i undervisning – IRIS Connect Credoet bag de seneste års mange læreruddannelsesreformer har været, at flere og dybere kundskaber vil styrke de studerendes forudsætninger for at løse opgaverne i pædagogisk praksis. Et forhold, som bliver overset i forbindelse med uddannelsesreformerne, er...... praksis, og hvad ”effektiv” undervisning er. Hovedantagelserne bag projektet er, at de studerendes personbundne kundskaber kan synliggøres, at deres lægmandsopfattelser af, hvad ”effektiv” undervisning er, kan udfordres gennem analyser og drøftelser, og at brugen af IRIS Connects dataindsamlings- og...

  17. Report printer (COBOL IRIS 50)

    International Nuclear Information System (INIS)

    Paul, Daniele

    1973-10-01

    The research thesis reports a detailed study of the Report Writer of the COBOL language in order to integrate it into the IRIS 50 COBOL compiler. In order to use existing compiler processing, the author developed a simulation of the Report Writer by using Cobol statements generated in the declarative part of the Division procedure. After a brief presentation of the IRIS 50 computer, the author presents the general plan of the compiler with modifications and adjunctions exclusively due to the Report Writer. The next part addresses the practical implementation and the problems met and solved during this implementation

  18. Protective effect of Iris germanica L. in β-amyloid-induced animal ...

    African Journals Online (AJOL)

    Protective effect of Iris germanica L. in β-amyloid-induced animal model of alzheimer's disease. ... The day after surgery, animals in treatment groups received different doses of the aqueous extract of Iris by gavage for 30 days. Morris water maze test (MWM) was performed to assess the effects of I. germanica on learning ...

  19. Effect of iris registration on outcomes of LASIK for myopia with the VISX CustomVue platform

    DEFF Research Database (Denmark)

    Moshirfar, Majid; Chen, Michael C; Espandar, Ladan

    2009-01-01

    PURPOSE: To compare visual outcomes after LASIK using the VISX STAR S4 CustomVue, with and without Iris Registration technology. METHODS: In this retrospective study, LASIK was performed on 239 myopic eyes, with or without astigmatism, of 142 patients. Iris registration LASIK was performed on 121...... eyes and non-iris registration LASIK was performed on 118 eyes. Primary outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and manifest refraction. RESULTS: At 6 months, the mean values for UCVA (logMAR) were 0.00 +/- 0.09 in the iris registration...... magnitude of error of surgically induced astigmatism was -0.09 in the iris registration group and -0.04 in the non-iris registration group (P = .25). CONCLUSIONS: Wavefront-guided LASIK with the VISX STAR S4 CustomVue laser system, independent of iris registration status, is effective, safe, and predictable...

  20. Sizes of secondary plant components for modularized IRIS balance of plant design

    International Nuclear Information System (INIS)

    Williamson, Martin; Townsend, Lawrence

    2003-01-01

    Herein we report on a conceptual design for a balance of plant (BOP) layout to coordinate with IRIS-like plants. The report consists of results of calculations that sizes of various BOP components. These calculations include the thermodynamic analyses and general sizing of the components in order to determine plant capability and plant layout for studies on modularity and transportability. Mathematical modeling of the BOP system involves a modified ORCENT2 code as well as standard heat transfer methods. Using typical values for PWR type plants, a general BOP design, and IRIS steam generator values, an ORCENT2 heat balance is carried out for the secondary side of the plant. Using the ORCENT2 output, standard heat transfer methods are then used to calculate system performance and component sizes. (author)

  1. CFD Analysis of the mixing process in the downcomer of IRIS reactor

    International Nuclear Information System (INIS)

    Diaz Bueno, Elizabeth; Montesino Otero, Maria E.; Rives Sanz, Ronny; Garcia, Carlos

    2015-01-01

    The boron ( 10 B) is a strong absorber of thermal neutrons and diluted as boric acid in the coolant of the pressurized water reactor helps to control the excess reactivity in the core of these facilities. The study of transients with deficiencies in the boron homogenization is very important in this technology because it inserts a strong reactivity in the reactor core with consequent threat to society and nature. The aim of this study is to evaluate the thermal-hydraulics losses and their influence on the process of heterogeneous boron dilution during normal system operation by using CFX code. Profiles of pressure, velocity and temperature of the downcomer reactor IRIS are obtained. The model developed also allows studying an event of total loss of flow. The results are applicable to the design of internal components and structures of IRIS downcomer. (Author)

  2. A giant traumatic iris cyst

    Directory of Open Access Journals (Sweden)

    Lott Pooi Wah

    2015-12-01

    Full Text Available A 52 year-old construction worker presented with progressive painful blurring of vision in the left eye associated with redness for past 1 month. There was a history of penetrating injury in the same eye 10 years ago and he underwent primary wound toilet and suturing, lens removal with intraocular lens implantation. Slit lamp examination revealed a corneal scar at 9’oclock, a large transilluminant iris cyst superotemporally and adherent to corneal endothelium. It was extended from angle of the pupil and obstructing the visual axis. The patient underwent excision of an iris cyst through superior limbal incision. Viscodissection was done to separate the cyst from the corneal endothelium and underlying iris stroma. Trypan blue ophthalmic solution was injected into the cyst to stain the cyst capsule. Post operatively 7 days, vision improved to 6/7.5 without complication. There was no recurrence up to 1 year postoperation. Histopathological finding revealed a benign cyst mass lined by simple cuboidal to nonkeratinized stratified squamous epithelium. We had achieved a good surgical outcome with no complication to date for our case study. We advocate this modified surgical method to completely remove iris cyst.

  3. IRIS Nuclear Power Plant design

    International Nuclear Information System (INIS)

    Carelli, M. D.; Cobian, J.

    2002-01-01

    IRIS(International Reactor Innovative and Secure) is a novel light water reactor with a modular, integral primary system configuration. This concept, initially developed in response to the first NERI solicitation, is now being pursued by an international consortium of 20 participants from seven countries. IRIS is designed to satisfy the four key requirements for Generation IV systems: enhanced safety, improved economics, proliferation resistance and waste minimization. Its main features are: small-to-medium power (100-335 MWe/module); long life core 5 to 10 years) without shuffling or refueling; optimized maintenance with repair shutdown intervals of a least four years; simplified compact design with the primary vessel housing steam generators, pressurizer and pumps; safety by design where accidents are positively eliminated by design rather than engineering to cope with their consequences; loss of coolant accidents of any size and loss of low accidents are eliminated as major safety concerns; estimated power generation total cost is projected to be competitive with other power options. IRIS is one of four new reactor designs currently under NRC review. Projected schedule calls for design certification by 2008 and being ready for deployment by 2001 or later. This rather short schedule is made possible by the fact that IRIS is based on proven light water technology and new technology development is not required. (Author)

  4. IRIS Final Technical Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    M. D. Carelli

    2003-11-03

    OAK-B135 This NERI project, originally started as the Secure Transportable Autonomous Light Water Reactor (STAR-LW) and currently known as the International Reactor Innovative and Secure (IRIS) project, had the objective of investigating a novel type of water-cooled reactor to satisfy the Generation IV goals: fuel cycle sustainability, enhanced reliability and safety, and improved economics. The research objectives over the three-year (1999-2002) program were as follows: First year: Assess various design alternatives and establish main characteristics of a point design; Second year: Perform feasibility and engineering assessment of the selected design solutions; Third year: Complete reactor design and performance evaluation, including cost assessment These objectives were fully attained and actually they served to launch IRIS as a full fledged project for eventual commercial deployment. The program did not terminate in 2002 at the end of the NERI program, and has just entered in its fifth year. This has been made possible by the IRIS project participants which have grown from the original four member, two-countries team to the current twenty members, nine countries consortium. All the consortium members work under their own funding and it is estimated that the value of their in-kind contributions over the life of the project has been of the order of $30M. Currently, approximately 100 people worldwide are involved in the project. A very important constituency of the IRIS project is the academia: 7 universities from four countries are members of the consortium and five more US universities are associated via parallel NERI programs. To date, 97 students have worked or are working on IRIS; 59 IRIS-related graduate theses have been prepared or are in preparation, and 41 of these students have already graduated with M.S. (33) or Ph.D. (8) degrees. This ''final'' report (final only as far as the NERI program is concerned) summarizes the work performed

  5. Iris recognition using image moments and k-means algorithm.

    Science.gov (United States)

    Khan, Yaser Daanial; Khan, Sher Afzal; Ahmad, Farooq; Islam, Saeed

    2014-01-01

    This paper presents a biometric technique for identification of a person using the iris image. The iris is first segmented from the acquired image of an eye using an edge detection algorithm. The disk shaped area of the iris is transformed into a rectangular form. Described moments are extracted from the grayscale image which yields a feature vector containing scale, rotation, and translation invariant moments. Images are clustered using the k-means algorithm and centroids for each cluster are computed. An arbitrary image is assumed to belong to the cluster whose centroid is the nearest to the feature vector in terms of Euclidean distance computed. The described model exhibits an accuracy of 98.5%.

  6. Systemic and Ophthalmologic Findings in Patients with Iris Coloboma

    Directory of Open Access Journals (Sweden)

    Sevda Ertekin

    2013-01-01

    Full Text Available Pur po se: Ocular coloboma is a rare malformation resulting from defective closure of the embryonic optic fissure. It can affect iris, retina, choroid, optic disc or ciliary body. This study reviews the clinical diagnosis and the accompanying ocular and systemic abnormalities in cases of iris coloboma. Ma te ri al and Met hod: Sixteen eyes of ten patients referred to our clinic and diagnosed as iris coloboma were included in the study and were reviewed retrospectively. Re sults: Seven cases were sporadic, and three cases were familial. Isolated iris coloboma was present in only one case, and chorioretinal involvement was present in all the others. Seven cases had involvement of the optic disc. Other ocular anomalies were unilateral microphthalmia in 3 cases, unilateral anophthalmia in 1 case, and unilateral microcornea in one case. Strabismus was present in the familial cases. Dis cus si on: In patients, diagnosed with iris coloboma, routine eye examination should be completed, refractive errors should be corrected, and these patients must be follewed for amblyopia. If strabismus is concominant, surgery can be performed. For potential complications, patients should be checked at regular intervals. (Turk J Ophthalmol 2013; 43: 19-22

  7. Iris structure and minor physical anomalies in schizophrenia.

    Science.gov (United States)

    Trixler, Dániel; Tényi, Tamás

    2017-10-01

    This study compared five human iris characteristics and minor physical anomalies (MPAs) between patients with schizophrenia (n = 32) and controls (n = 31). Correlations between iris characteristics and MPAs were expected, due to their same ectodermic origin. Iris macro photos were taken and quantified in five categories mentioned before. MPAs were also examined in both groups. Our results show significant differences in the frequency of pigment dots of the iris and total number of MPAs between groups. Other significant differences were found in the extension of concentric furrows, as they were more common in healthy subjects, while Wolfflin nodules occurred significantly more often in patients with schizophrenia. Expected difference in Fuch's crypts could not be observed between groups. Light eye color was positively correlated to pigment dots and Wolfflin nodules, and negatively correlated with concentric furrows. Dark eye color showed positive correlation with concentric furrows, and negative correlation with pigment dots and concentric furrows. A gender effect could also been observed: male individuals showed moderate positive correlations between pigment dots and total MPAs frequency, while this couldn't be observed in the female group. Our findings suggest possible connections between iris characteristics and MPAs, where males are more prone to deviations. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Efficient iris recognition by characterizing key local variations.

    Science.gov (United States)

    Ma, Li; Tan, Tieniu; Wang, Yunhong; Zhang, Dexin

    2004-06-01

    Unlike other biometrics such as fingerprints and face, the distinct aspect of iris comes from randomly distributed features. This leads to its high reliability for personal identification, and at the same time, the difficulty in effectively representing such details in an image. This paper describes an efficient algorithm for iris recognition by characterizing key local variations. The basic idea is that local sharp variation points, denoting the appearing or vanishing of an important image structure, are utilized to represent the characteristics of the iris. The whole procedure of feature extraction includes two steps: 1) a set of one-dimensional intensity signals is constructed to effectively characterize the most important information of the original two-dimensional image; 2) using a particular class of wavelets, a position sequence of local sharp variation points in such signals is recorded as features. We also present a fast matching scheme based on exclusive OR operation to compute the similarity between a pair of position sequences. Experimental results on 2255 iris images show that the performance of the proposed method is encouraging and comparable to the best iris recognition algorithm found in the current literature.

  9. IRIS Arrays: Observing Wavefields at Multiple Scales and Frequencies

    Science.gov (United States)

    Sumy, D. F.; Woodward, R.; Frassetto, A.

    2014-12-01

    The Incorporated Research Institutions for Seismology (IRIS) provides instruments for creating and operating seismic arrays at a wide range of scales. As an example, for over thirty years the IRIS PASSCAL program has provided instruments to individual Principal Investigators to deploy arrays of all shapes and sizes on every continent. These arrays have ranged from just a few sensors to hundreds or even thousands of sensors, covering areas with dimensions of meters to thousands of kilometers. IRIS also operates arrays directly, such as the USArray Transportable Array (TA) as part of the EarthScope program. Since 2004, the TA has rolled across North America, at any given time spanning a swath of approximately 800 km by 2,500 km, and thus far sampling 2% of the Earth's surface. This achievement includes all of the lower-48 U.S., southernmost Canada, and now parts of Alaska. IRIS has also facilitated specialized arrays in polar environments and on the seafloor. In all cases, the data from these arrays are freely available to the scientific community. As the community of scientists who use IRIS facilities and data look to the future they have identified a clear need for new array capabilities. In particular, as part of its Wavefields Initiative, IRIS is exploring new technologies that can enable large, dense array deployments to record unaliased wavefields at a wide range of frequencies. Large-scale arrays might utilize multiple sensor technologies to best achieve observing objectives and optimize equipment and logistical costs. Improvements in packaging and power systems can provide equipment with reduced size, weight, and power that will reduce logistical constraints for large experiments, and can make a critical difference for deployments in harsh environments or other situations where rapid deployment is required. We will review the range of existing IRIS array capabilities with an overview of previous and current deployments and examples of data and results. We

  10. Barumiki antocyjanowe u Iris germanica [Anthocyanin pigments in Iris germanica L.

    Directory of Open Access Journals (Sweden)

    J. Szczepańska

    2015-06-01

    Full Text Available Anthocyanin pigments occurring in the flowers of Iris germanica were investigated in five varieties: Rota, Wedgewood, Empress of India, Deputate Nomblot and Joanna. The relation between the colour of the flower and the amount of the pigment was studied. The pigments were extracted from the dry plant material with 1% hydrochloric acid in methanol. Paper chromatography and colorimetric determinations were used for identification of the pigments and their quantitative determination. The results allow the following conclusions: 1. The varieties investigated were characterized toy the occurrence of delphinidine glycoside; 2. The colour intensity is dependent on the anthocyanin pigments; 3. The colour spectrum of Iris sp. flowersis greatly extended by yellow copigments.

  11. Results of Absolute Cavity Pyrgeometer (ACP), InfraRed Integrating Sphere (IRIS), and Atmospheric Emitted Radiance Interferometer (AERI) Comparisons and CIMO Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Reda, Ibrahim M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dooraghi, Michael R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Grobner, Julian [Physikalisch-Meteorologisches Observatorium Davos (PMOD); Wacker, Stefan [Deutscher Wetterdienst (DWD); Thomann, Christian [Physikalisch-Meteorologisches Observatorium Davos (PMOD); Long, Chuck [National Oceanic and Atmospheric Administration (NOAA); McComiskey, Allison [National Oceanic and Atmospheric Administration (NOAA); Ruedi, Isabelle [Physikalisch-Meteorologisches Observatorium Davos (PMOD); Forgan, Bruce [Bureau of Meteorology, Melbourne; Turner, Dave [National Oceanic and Atmospheric Administration (NOAA)

    2018-03-05

    Presenting results of five comparisons between ACPs and IRISs and the difference between the longwave irradiance measured by the ACPs and IRISs versus the average irradiance measured by the WISG. The process of CIMO recommendation to establish the world reference for measuring the atmospheric longwave irradiance with traceability to the International System of Units (SI) is also presented.

  12. Engineering model cryocooler test results

    International Nuclear Information System (INIS)

    Skimko, M.A.; Stacy, W.D.; McCormick, J.A.

    1992-01-01

    This paper reports that recent testing of diaphragm-defined, Stirling-cycle machines and components has demonstrated cooling performance potential, validated the design code, and confirmed several critical operating characteristics. A breadboard cryocooler was rebuilt and tested from cryogenic to near-ambient cold end temperatures. There was a significant increase in capacity at cryogenic temperatures and the performance results compared will with code predictions at all temperatures. Further testing on a breadboard diaphragm compressor validated the calculated requirement for a minimum axial clearance between diaphragms and mating heads

  13. Measuring Biometric Sample Quality in terms of Biometric Feature Information in Iris Images

    Directory of Open Access Journals (Sweden)

    R. Youmaran

    2012-01-01

    Full Text Available This paper develops an approach to measure the information content in a biometric feature representation of iris images. In this context, the biometric feature information is calculated using the relative entropy between the intraclass and interclass feature distributions. The collected data is regularized using a Gaussian model of the feature covariances in order to practically measure the biometric information with limited data samples. An example of this method is shown for iris templates processed using Principal-Component Analysis- (PCA- and Independent-Component Analysis- (ICA- based feature decomposition schemes. From this, the biometric feature information is calculated to be approximately 278 bits for PCA and 288 bits for ICA iris features using Masek's iris recognition scheme. This value approximately matches previous estimates of iris information content.

  14. Innovative features and fuel design approach in the iris reactor

    International Nuclear Information System (INIS)

    Petrovic, B.; Carelli, M.; Greenspan, E.; Matsumoto, H.; Padovani, E.; Ganda, F.

    2002-01-01

    The International Reactor Innovative and Secure (IRIS) is being developed by an international consortium of industry, laboratory, university and utility establishments, led by Westinghouse. The IRIS design addresses key requirements associated with advanced reactors, including improved safety, enhanced proliferation resistance, competitive electricity production cost, and improved waste management. IRIS is a modular, small/medium size (335 MWe) PWR with an integral vessel configuration. The objective has been to base its design on proven LWR technology, so that no new technology development is needed and near-term deployment is possible, yet at the same time to introduce innovative features making it attractive when compared to present PWRs. These opposing requirements resulted in an evolutionary approach to fuel and core design, balancing new features against the need to avoid extensive testing and demonstration programmes. (author)

  15. Free-Floating Iris Cyst in a Patient with Recurrent Iritis

    Directory of Open Access Journals (Sweden)

    Joanne M.Y. Teong

    2015-06-01

    Full Text Available Purpose: We describe an unusual clinical finding of a free-floating iris cyst in a patient with recurrent iritis. Method: The clinical finding of a free-floating iris cyst was recorded using slit-lamp photography. Results: A 39-year-old male with a 5-year history of recurrent right iritis was found to have a small mobile iris cyst within his right anterior chamber, first identified 3 years ago. The patient did not experience any discomfort or visual symptoms resulting from the cyst. Conclusion: Surgical removal is not indicated for asymptomatic non-progressive free-floating iris cysts. The significance of a free-floating iris cyst in the setting of recurrent iritis remains unknown.

  16. Heterogeneous iris image hallucination using sparse representation on a learned heterogeneous patch dictionary

    Science.gov (United States)

    Li, Yung-Hui; Zheng, Bo-Ren; Ji, Dai-Yan; Tien, Chung-Hao; Liu, Po-Tsun

    2014-09-01

    Cross sensor iris matching may seriously degrade the recognition performance because of the sensor mis-match problem of iris images between the enrollment and test stage. In this paper, we propose two novel patch-based heterogeneous dictionary learning method to attack this problem. The first method applies the latest sparse representation theory while the second method tries to learn the correspondence relationship through PCA in heterogeneous patch space. Both methods learn the basic atoms in iris textures across different image sensors and build connections between them. After such connections are built, at test stage, it is possible to hallucinate (synthesize) iris images across different sensors. By matching training images with hallucinated images, the recognition rate can be successfully enhanced. The experimental results showed the satisfied results both visually and in terms of recognition rate. Experimenting with an iris database consisting of 3015 images, we show that the EER is decreased 39.4% relatively by the proposed method.

  17. Secure and Robust Iris Recognition Using Random Projections and Sparse Representations.

    Science.gov (United States)

    Pillai, Jaishanker K; Patel, Vishal M; Chellappa, Rama; Ratha, Nalini K

    2011-09-01

    Noncontact biometrics such as face and iris have additional benefits over contact-based biometrics such as fingerprint and hand geometry. However, three important challenges need to be addressed in a noncontact biometrics-based authentication system: ability to handle unconstrained acquisition, robust and accurate matching, and privacy enhancement without compromising security. In this paper, we propose a unified framework based on random projections and sparse representations, that can simultaneously address all three issues mentioned above in relation to iris biometrics. Our proposed quality measure can handle segmentation errors and a wide variety of possible artifacts during iris acquisition. We demonstrate how the proposed approach can be easily extended to handle alignment variations and recognition from iris videos, resulting in a robust and accurate system. The proposed approach includes enhancements to privacy and security by providing ways to create cancelable iris templates. Results on public data sets show significant benefits of the proposed approach.

  18. Aging aggravates long-term renal ischemia-reperfusion injury in a rat model.

    Science.gov (United States)

    Xu, Xianlin; Fan, Min; He, Xiaozhou; Liu, Jipu; Qin, Jiandi; Ye, Jianan

    2014-03-01

    Ischemia-reperfusion injury (IRI) has been considered as the major cause of acute kidney injury and can result in poor long-term graft function. Functional recovery after IRI is impaired in the elderly. In the present study, we aimed to compare kidney morphology, function, oxidative stress, inflammation, and development of renal fibrosis in young and aged rats after renal IRI. Rat models of warm renal IRI were established by clamping left pedicles for 45 min after right nephrectomy, then the clamp was removed, and kidneys were reperfused for up to 12 wk. Biochemical and histologic renal damage were assessed at 12 wk after reperfusion. The immunohistochemical staining of monocyte macrophage antigen-1 (ED-1) and transforming growth factor beta 1 (TGF-β1) and messenger RNA level of TGF-β1 in the kidney were analyzed. Renal IRI caused significant increases of malondialdehyde and 8-hydroxydeoxyguanosine levels and a decrease of superoxide dismutase activity in young and aged IRI rats; however, these changes were more obvious in the aged rats. IRI resulted in severe inflammation and tubulointerstitial fibrosis with decreased creatinine (Cr) clearance and increased histologic damage in aged rats compared with young rats. Moreover, we measured the ratio of Cr clearance between young and aged IRI rats. It demonstrated that aged IRI rats did have poor Cr clearance compared with the young IRI rats. ED-1 and TGF-β1 expression levels in the kidney were significantly higher in aged rats than in young rats after IRI. Aged rats are more susceptible to IRI-induced renal failure, which may associate with the increased oxidative stress, increased histologic damage, and increased inflammation and tubulointerstitial fibrosis. Targeting oxidative stress and inflammatory response should improve the kidney recovery after IRI. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Increasing the information acquisition volume in iris recognition systems.

    Science.gov (United States)

    Barwick, D Shane

    2008-09-10

    A significant hurdle for the widespread adoption of iris recognition in security applications is that the typically small imaging volume for eye placement results in systems that are not user friendly. Separable cubic phase plates at the lens pupil have been shown to ameliorate this disadvantage by increasing the depth of field. However, these phase masks have limitations on how efficiently they can capture the information-bearing spatial frequencies in iris images. The performance gains in information acquisition that can be achieved by more general, nonseparable phase masks is demonstrated. A detailed design method is presented, and simulations using representative designs allow for performance comparisons.

  20. A new method for generating an invariant iris private key based on the fuzzy vault system.

    Science.gov (United States)

    Lee, Youn Joo; Park, Kang Ryoung; Lee, Sung Joo; Bae, Kwanghyuk; Kim, Jaihie

    2008-10-01

    Cryptographic systems have been widely used in many information security applications. One main challenge that these systems have faced has been how to protect private keys from attackers. Recently, biometric cryptosystems have been introduced as a reliable way of concealing private keys by using biometric data. A fuzzy vault refers to a biometric cryptosystem that can be used to effectively protect private keys and to release them only when legitimate users enter their biometric data. In biometric systems, a critical problem is storing biometric templates in a database. However, fuzzy vault systems do not need to directly store these templates since they are combined with private keys by using cryptography. Previous fuzzy vault systems were designed by using fingerprint, face, and so on. However, there has been no attempt to implement a fuzzy vault system that used an iris. In biometric applications, it is widely known that an iris can discriminate between persons better than other biometric modalities. In this paper, we propose a reliable fuzzy vault system based on local iris features. We extracted multiple iris features from multiple local regions in a given iris image, and the exact values of the unordered set were then produced using the clustering method. To align the iris templates with the new input iris data, a shift-matching technique was applied. Experimental results showed that 128-bit private keys were securely and robustly generated by using any given iris data without requiring prealignment.

  1. Small incision guarded hydroaspiration of iris lesions.

    Science.gov (United States)

    Singh, Arun D

    2017-11-01

    To describe the technique and results of a minimally invasive surgical technique for resection of small iris lesions. Consecutive case series of 22 patients with localised, small iris lesions that were resected using the described surgical technique that composed of multiple, small corneal incisions created to allow for internal iris resection with 23-gauge horizontal vitrectomy scissors, followed by guarded tumour aspiration through a clear plastic tubing (diameter 3.5 mm) primed with viscoelastic agent. The mean largest basal diameter was 3.0 mm (range 1.5-5.0 mm; median 3.0 mm) and mean thickness was 1.3 mm (range 0.5-2.5 mm; median 1.0 mm). Use of multiple (2-4) small corneal incisions (range 2.0-3.0 mm; mean 2.8 mm) allowed reduced postoperative morbidity (significant hyphema (0%), hypotony (0%), wound leak (0%), >2 line change in best corrected visual acuity at postoperative 1 week (4.5%) and mean corneal astigmatism of 1.0 D (range 0.14-2.99 D; median 0.8 D) at postoperative 4-12 weeks. The tumour could be resected with clear surgical margins in all neoplastic cases (benign (2), borderline (1) and malignant (16)). Local recurrence or metastases were not observed in any melanoma case over a mean follow-up of 33.0 months (range 1.0-90.0 months; median 33.5 months). Small incision guarded hydroaspiration is a minimally invasive surgical technique for resection of select small iris lesions. Use of multiple small corneal incisions avoids morbidity associated with a single large corneoscleral incision, and use of guarded aspiration may eliminate the risk of wound contamination by the malignant tumour. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. An Improved Iris Recognition Algorithm Based on Hybrid Feature and ELM

    Science.gov (United States)

    Wang, Juan

    2018-03-01

    The iris image is easily polluted by noise and uneven light. This paper proposed an improved extreme learning machine (ELM) based iris recognition algorithm with hybrid feature. 2D-Gabor filters and GLCM is employed to generate a multi-granularity hybrid feature vector. 2D-Gabor filter and GLCM feature work for capturing low-intermediate frequency and high frequency texture information, respectively. Finally, we utilize extreme learning machine for iris recognition. Experimental results reveal our proposed ELM based multi-granularity iris recognition algorithm (ELM-MGIR) has higher accuracy of 99.86%, and lower EER of 0.12% under the premise of real-time performance. The proposed ELM-MGIR algorithm outperforms other mainstream iris recognition algorithms.

  3. Lentes plegables suturadas a iris

    Directory of Open Access Journals (Sweden)

    Dunia Cruz Izquierdo

    Full Text Available Para la corrección quirúrgica de la afaquia existen en la actualidad varias técnicas quirúrgicas que permiten fijar los lentes intraoculares plegables o rígidos en cámara posterior suturados al iris o al sulcus ciliar. En estas circunstancias el cirujano determinará cuándo, dónde y el tipo de lente mejor a implantar. Se presenta un paciente con una afaquia traumática del ojo izquierdo, con agudeza visual sin corrección de movimiento de mano a 1 m. Se le realizó implante secundario de lente intraocular plegable de cámara posterior suturada al iris. En el examen biomicroscópico en lámpara de hendidura del ojo izquierdo se observó midriasis media paralítica, refracción dinámica de +11,00 (0,6 y tensión ocular normal. Se le realizó examen por bimicroscopía indirecta sin alteración. Al mes de operado la agudeza visual mejor corregida alcanzó la unidad de visión. Las complicaciones presentadas fueron ovalización de la pupila y depósitos de pigmentos de iris en el lente intraocular.

  4. DCT-based iris recognition.

    Science.gov (United States)

    Monro, Donald M; Rakshit, Soumyadip; Zhang, Dexin

    2007-04-01

    This paper presents a novel iris coding method based on differences of discrete cosine transform (DCT) coefficients of overlapped angular patches from normalized iris images. The feature extraction capabilities of the DCT are optimized on the two largest publicly available iris image data sets, 2,156 images of 308 eyes from the CASIA database and 2,955 images of 150 eyes from the Bath database. On this data, we achieve 100 percent Correct Recognition Rate (CRR) and perfect Receiver-Operating Characteristic (ROC) Curves with no registered false accepts or rejects. Individual feature bit and patch position parameters are optimized for matching through a product-of-sum approach to Hamming distance calculation. For verification, a variable threshold is applied to the distance metric and the False Acceptance Rate (FAR) and False Rejection Rate (FRR) are recorded. A new worst-case metric is proposed for predicting practical system performance in the absence of matching failures, and the worst case theoretical Equal Error Rate (EER) is predicted to be as low as 2.59 x 10(-4) on the available data sets.

  5. Association of iris crypts with acute primary angle closure.

    Science.gov (United States)

    Koh, Victor; Chua, Jacqueline; Shi, Yuan; Thakku, Sri Gowtham; Lee, Ryan; Nongpiur, Monisha E; Baskaran, Mani; Kumar, Rajesh S; Perera, Shamira; Aung, Tin; Cheng, Ching-Yu

    2017-10-01

    To determine the relationship between iris surface features and acute primary angle closure (APAC) in eyes with angle closure. Case-control study involving Asian patients diagnosed with previous APAC, primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG) at an eye centre in Singapore between August 2012 and January 2015. Participants underwent ophthalmic examination and digital slit-lamp iris photography. Iris surface features were graded based on crypts, furrows and colour. Fellow eyes of APAC were compared with PACS and PAC/PACG eyes with regard to their iris surface features. Occurrence of APAC. A total of 309 patients (71 APAC, 139 PACS, 47 PAC and 52 PACG) were included (mean age: 67.7±7.2 years and 36.6% male). Compared with PACS, higher crypt grade was significantly associated with lower odds of APAC (OR=0.58 for one grade higher in crypt grade; p=0.027, adjusted for age, gender, ethnicity and pupil diameter). The results remained similar when compared with PAC/PACG group (OR=0.58 for one grade higher in crypt grade; p=0.043). We did not observe any significant associations between iris furrows or colour with presence of APAC. Our study comprising Asian eyes with angle closure suggests that the presence of a higher crypt grading may be protective for APAC. As such, assessing iris surface architecture for crypts could be a new measure for risk stratification of developing APAC in eyes with angle closure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  6. Iris features-based heart disease diagnosis by computer vision

    Science.gov (United States)

    Nguchu, Benedictor A.; Li, Li

    2017-07-01

    The study takes advantage of several new breakthroughs in computer vision technology to develop a new mid-irisbiomedical platform that processes iris image for early detection of heart-disease. Guaranteeing early detection of heart disease provides a possibility of having non-surgical treatment as suggested by biomedical researchers and associated institutions. However, our observation discovered that, a clinical practicable solution which could be both sensible and specific for early detection is still lacking. Due to this, the rate of majority vulnerable to death is highly increasing. The delayed diagnostic procedures, inefficiency, and complications of available methods are the other reasons for this catastrophe. Therefore, this research proposes the novel IFB (Iris Features Based) method for diagnosis of premature, and early stage heart disease. The method incorporates computer vision and iridology to obtain a robust, non-contact, nonradioactive, and cost-effective diagnostic tool. The method analyzes abnormal inherent weakness in tissues, change in color and patterns, of a specific region of iris that responds to impulses of heart organ as per Bernard Jensen-iris Chart. The changes in iris infer the presence of degenerative abnormalities in heart organ. These changes are precisely detected and analyzed by IFB method that includes, tensor-based-gradient(TBG), multi orientations gabor filters(GF), textural oriented features(TOF), and speed-up robust features(SURF). Kernel and Multi class oriented support vector machines classifiers are used for classifying normal and pathological iris features. Experimental results demonstrated that the proposed method, not only has better diagnostic performance, but also provides an insight for early detection of other diseases.

  7. PLATEAU IRIS – DIAGNOSIS AND TREATMENT

    Science.gov (United States)

    Stefan, Cornel; Iliescu, Daniela Adriana; Batras, Mehdi; Timaru, Cristina Mihaela; De Simone, Algerino

    2015-01-01

    Objectives: The objective of our study was to review the current knowledge on the diagnosis and treatment options of plateau iris configuration and syndrome. Systematic review methodology: Relevant publications on plateau iris that were published until 2014. Conclusions: Plateau iris syndrome is a form of primary angle closure glaucoma caused by a large or anteriorly positioned ciliary body that leads to mechanical obstruction of trabecular meshwork. This condition is most often found in younger patients. Plateau iris has been considered an abnormal anatomic variant of the iris that can be diagnosed on ultrasound biomicroscopy or optical coherence tomography of anterior segment. Patients with plateau iris syndrome can be recognized by the lack of response in angle opening after iridotomy. The treatment of choice in these cases is argon laser peripheral iridoplasty PMID:27373109

  8. PLATEAU IRIS--DIAGNOSIS AND TREATMENT.

    Science.gov (United States)

    Stefan, Cornel; Iliescu, Daniela Adriana; Batras, Mehdi; Timaru, Cristina Mihaela; De Simone, Algerino

    2015-01-01

    The objective of our study was to review the current knowledge on the diagnosis and treatment options of plateau iris configuration and syndrome. Relevant publications on plateau iris that were published until 2014. Plateau iris syndrome is a form of primary angle closure glaucoma caused by a large or anteriorly positioned ciliary body that leads to mechanical obstruction of trabecular meshwork. This condition is most often found in younger patients. Plateau iris has been considered an abnormal anatomic variant of the iris that can be diagnosed on ultrasound biomicroscopy or optical coherence tomography of anterior segment. Patients with plateau iris syndrome can be recognized by the lack of response in angle opening after iridotomy. The treatment of choice in these cases is argon laser peripheral iridoplasty.

  9. Iris analysis for biometric recognition systems

    CERN Document Server

    Bodade, Rajesh M

    2014-01-01

    The book presents three most significant areas in Biometrics and Pattern Recognition. A step-by-step approach for design and implementation of Dual Tree Complex Wavelet Transform (DTCWT) plus Rotated Complex Wavelet Filters (RCWF) is discussed in detail. In addition to the above, the book provides detailed analysis of iris images and two methods of iris segmentation. It also discusses simplified study of some subspace-based methods and distance measures for iris recognition backed by empirical studies and statistical success verifications.

  10. Preface: The International Reference Ionosphere (IRI) at equatorial latitudes

    Science.gov (United States)

    Reinisch, Bodo; Bilitza, Dieter

    2017-07-01

    This issue of Advances in Space Research includes papers that report and discuss improvements of the International Reference Ionosphere (IRI). IRI is the international standard for the representation of the plasma in Earth's ionosphere and recognized as such by the Committee on Space Research (COSPAR), the International Union of Radio Science (URSI), the International Telecommunication Union (ITU), and the International Standardization Organization (ISO). As requested, particularly by COSPAR and URSI, IRI is an empirical model relying on most of the available and reliable ground and space observations of the ionosphere. As new data become available and as older data sources are fully exploited the IRI model undergoes improvement cycles to stay as close to the existing data record as possible. The latest episode of this process is documented in the papers included in this issue using data from the worldwide network of ionosondes, from a few of the incoherent scatter radars, from the Alouette and ISIS topside sounders, and from the Global Navigation Satellite Systems (GNSS). The focus of this issue is on the equatorial and low latitude region that is of special importance for ionospheric physics because it includes the largest densities and steep density gradients in the double hump latitudinal structure, the Equatorial Ionization Anomaly (EIA), which is characteristic for this region.

  11. Exploring the feasibility of iris recognition for visible spectrum iris images obtained using smartphone camera

    Science.gov (United States)

    Trokielewicz, Mateusz; Bartuzi, Ewelina; Michowska, Katarzyna; Andrzejewska, Antonina; Selegrat, Monika

    2015-09-01

    In the age of modern, hyperconnected society that increasingly relies on mobile devices and solutions, implementing a reliable and accurate biometric system employing iris recognition presents new challenges. Typical biometric systems employing iris analysis require expensive and complicated hardware. We therefore explore an alternative way using visible spectrum iris imaging. This paper aims at answering several questions related to applying iris biometrics for images obtained in the visible spectrum using smartphone camera. Can irides be successfully and effortlessly imaged using a smartphone's built-in camera? Can existing iris recognition methods perform well when presented with such images? The main advantage of using near-infrared (NIR) illumination in dedicated iris recognition cameras is good performance almost independent of the iris color and pigmentation. Are the images obtained from smartphone's camera of sufficient quality even for the dark irides? We present experiments incorporating simple image preprocessing to find the best visibility of iris texture, followed by a performance study to assess whether iris recognition methods originally aimed at NIR iris images perform well with visible light images. To our best knowledge this is the first comprehensive analysis of iris recognition performance using a database of high-quality images collected in visible light using the smartphones flashlight together with the application of commercial off-the-shelf (COTS) iris recognition methods.

  12. Computational cameras for moving iris recognition

    Science.gov (United States)

    McCloskey, Scott; Venkatesha, Sharath

    2015-05-01

    Iris-based biometric identification is increasingly used for facility access and other security applications. Like all methods that exploit visual information, however, iris systems are limited by the quality of captured images. Optical defocus due to a small depth of field (DOF) is one such challenge, as is the acquisition of sharply-focused iris images from subjects in motion. This manuscript describes the application of computational motion-deblurring cameras to the problem of moving iris capture, from the underlying theory to system considerations and performance data.

  13. Characterization of a cartilage-like engineered biomass using a self-aggregating suspension culture model: molecular composition using FT-IRIS.

    Science.gov (United States)

    Kim, Minwook; Kraft, Jeffrey J; Volk, Andrew C; Pugarelli, Joan; Pleshko, Nancy; Dodge, George R

    2011-12-01

    Maintenance of chondrocyte phenotype and robust expression and organization of macromolecular components with suitable cartilaginous properties is an ultimate goal in cartilage tissue engineering. We used a self-aggregating suspension culture (SASC) method to produce an engineered cartilage, "cartilage tissue analog" (CTA). With an objective of understanding the stability of phenotype of the CTA over long periods, we cultured chondrocytes up to 4 years and analyzed the matrix. Both early (eCTAs) (6 months) and aged (aCTAs) (4 years) showed type II collagen throughout with higher concentrations near the edge. Using Fourier transform-infrared imaging spectroscopy (FT-IRIS), proteoglycan/collagen ratio of eCTA was 2.8 times greater than native cartilage at 1 week, but the ratio was balanced to native level (p = 0.017) by 36 weeks. Surprisingly, aCTAs maintained the hyaline characteristics, but there was evidence of calcification within the tissue with a distinct range of intensities. Mineral/matrix ratio of those aCTA with "intensive" calcification was significantly higher (p = 0.017) than the "partial," but when compared to native bone the ratio of "intensive" aCTAs was 2.4 times lower. In this study we utilized the imaging approach of FT-IRIS and have shown that a biomaterial formed is compositionally closely related to natural cartilage for long periods in culture. We show that this culture platform can maintain a CTA for extended periods of time (4 years) and under those conditions signs of mineralization can be found. This method of cartilage tissue engineering is a promising method to generate cartilaginous biomaterial and may have potential to be utilized in both cartilage and boney repairs. Copyright © 2011 Orthopaedic Research Society.

  14. Degradation monitoring in IRIS steam generators

    International Nuclear Information System (INIS)

    Alpay, B.; Holloway, J. P.; Lee, J. C.

    2007-01-01

    We present a degradation monitoring technique based on unscented Kalman filtering (UKF), which uses a nonlinear system model without linearization to estimate the status of the component/state variables. To test the applicability of the methodology, the fouling of tubes is chosen among various degradation mechanisms for the IRIS (International Reactor Innovative and Secure) steam generators (SGs). The degradation monitoring algorithm diagnoses the tube fouling and estimates the thickness of the crud deposited on the secondary side of the SG along with the increase in the pressure drop triggered by fouling. A stand-alone SG model developed with the RELAP5 code was used to simulate the transient behavior of the SG and drive an UKF state estimate. By using the secondary side outlet temperature as the measurement and the nodal pressures along the secondary side as states, UKF generated accurate estimates of the crud layer thicknesses for different crud formations. (authors)

  15. Iterative Redeployment of Illumination and Sensing (IRIS): Application to STW-SAR Imaging

    National Research Council Canada - National Science Library

    Marble, Jay; Raich, Raviv; Hero, Alfred O

    2006-01-01

    .... The IRIS algorithm has the following features: (1) use of a sparse Bayesian image model that captures the free-space dominated propagation characteristics of interiors of man-made structures such as caves and residences; (2...

  16. Single application on iris localization technology in excimer laser for astigmatism

    Directory of Open Access Journals (Sweden)

    Jun-Hua Hao

    2014-06-01

    Full Text Available AIM:To discuss the single application on iris localization technology in excimer laser for the treatment of astigmatism. METHODS:Totally 203 cases(406 eyesof laser in situ keratomileusis(LASIKin the treatment of compound myopic astigmatism patients were operated from November 2011 to November 2012 in our hospital. They were divided into two groups. One was observation group using iris localization and the other was control group using routine operation. Patients in the observation group of 100 cases(200 eyes, aged 18-43 years old, spherical diopter was -1.25 to -8.75D, astigmatism was -1.0 to -3.25D. In control group, 103 patients(206 eyes, aged 19-44 years old, spherical diopter was -1.75-9.50D, astigmatism was -1.0 to -3.25D. The patients in the observation group before the application of WaveScan aberrometer check for iris image, spherical lens, cylindrical lens and astigmatism axis data operation, only single application of iris location, without using wavefront aberration guided technology, laser cutting patterns for conventional LASIK model, spherical, cylindrical mirror and astigmatism axis data source to preoperative wavefront aberration results. The control group received routine LASIK. It was applicated comprehensive optometry optometry respectively to examine astigmatism and axial, based on the computer analysis during the preoperative, 1wk after the operation, and 6mo. Analysis of using SPSS 17 statistical software, it was independent-sample t test between the two groups of residual astigmatism and astigmatism axis. RESULTS:Postoperative residual astigmatism, the observation group was significantly better than the control group. Astigmatism axial measurement after operation, the observation group was significantly less than that of the control group. Postoperative visual acuity at 6mo, the observation group was better than that of the control group. The difference was statistically significant. CONCLUSION: For patients who cannot

  17. Nuclear power desalinating complex with IRIS reactor plant and Russian distillation desalinating unit

    International Nuclear Information System (INIS)

    Kostin, V. I.; Panov, Yu.K.; Polunichev, V. I.; Fateev, S. A.; Gureeva, L. V.

    2004-01-01

    This paper has been prepared as a result of Russian activities on the development of nuclear power desalinating complex (NPDC) with the IRIS reactor plant (RP). The purpose of the activities was to develop the conceptual design of power desalinating complex (PDC) and to evaluate technical and economical indices, commercial attractiveness and economical efficiency of PDC based on an IRIS RP with distillation desalinating plants. The paper presents the main results of studies as applied to dual-purpose PDC based on IRIS RP with different types of desalinating plants, namely: characteristics of nuclear power desalinating complex based on IRIS reactor plant using Russian distillation desalinating technologies; prospective options of interface circuits of the IRIS RP with desalinating plants; evaluations of NPDC with IRIS RP output based on selected desalinating technologies for water and electric power supplied to the grid; cost of water generated by NPDC for selected interface circuits made by the IAEA DEEP code as well as by the Russian TEO-INVEST code; cost evaluation results for desalinated water of PDC operating on fossil fuel and conditions for competitiveness of the nuclear PDC based on IRIS RP compared with analog desalinating complexes operating on fossil fuel.(author)

  18. Feature Set Fusion for Spoof Iris Detection

    Directory of Open Access Journals (Sweden)

    P. V. L. Suvarchala

    2018-04-01

    Full Text Available Iris recognition is considered as one of the most promising noninvasive biometric systems providing automated human identification. Numerous programs, like unique ID program in India - Aadhar, include iris biometric to provide distinctive identity identification to citizens. The active area is usually captured under non ideal imaging conditions. It usually suffers from poor brightness, low contrast, blur due to camera or subject's relative movement and eyelid eyelash occlusions. Besides the technical challenges, iris recognition started facing sophisticated threats like spoof attacks. Therefore it is vital that the integrity of such large scale iris deployments must be preserved. This paper presents the development of a new spoof resistant approach which exploits the statistical dependencies of both general eye and localized iris regions in textural domain using spatial gray level dependence matrix (SGLDM, gray level run length matrix (GLRLM and contourlets in transform domain. We did experiments on publicly available fake and lens iris image databases. Correct classification rate obtained with ATVS-FIr iris database is 100% while it is 95.63% and 88.83% with IITD spoof iris databases respectively.

  19. [Electronic Device for Retinal and Iris Imaging].

    Science.gov (United States)

    Drahanský, M; Kolář, R; Mňuk, T

    This paper describes design and construction of a new device for automatic capturing of eye retina and iris. This device has two possible ways of utilization - either for biometric purposes (persons recognition on the base of their eye characteristics) or for medical purposes as supporting diagnostic device. eye retina, eye iris, device, acquisition, image.

  20. In Vitro Antimicrobial Activity of Iris pseudacorus and Urtica dioica

    Directory of Open Access Journals (Sweden)

    Maryam Ramtin

    2014-03-01

    Full Text Available Background: In this study, the effects of antibacterial activity of Urtica dioica and Iris pseudacorus essential oils, native plant northern of Iran, were investigated for some selected bacteria. Material and Methods: The influence of essential oils was tested by the using of disk diffusion and micro-broth dilution methods against standard strains of the picked out bacteria. Gas Chromatography/Mass Spectroscopy (GC/MS analysis, bioactivity determination, Minimum inhibitory concentrations (MIC and minimum bactericidal concentration (MBC of essential oils were utilized for this goal. Results: This study showed that, Inhibition zone diameter varied from 11 to 19 mm and 9 to 17 mm for Urtica dioica and Iris pseudacorus respectively. In contrast, this figure fluctuated from 19 to 28 mm and 7 to 17 mm for gentamicin and ampicillin separately. By the application of micro-broth dilution technique, MICs for 1% essential oils were 1.8-7.5 μg/ml and 3.75-15 μg/ml for, Urtica dioica and Iris pseudacorus against gram-positive and gram-negative bacteria individually. Furthermore, the MBCs of herbal essences were 1.8-15 μg/ml for, Urtica dioica and 15-30 μg/ml for Iris. Conclusion: The application of essential oils for the bio-control of diseases, as a novel emerging alternative to antimicrobial treatments, lead to safer and more environmental management for infective diseases4T.4T

  1. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    Science.gov (United States)

    2012-01-01

    Background To assess the efficacy, clinical outcomes, visual acuity (VA), incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany) were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%), 20/60 or better in 12 eyes (92%), and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method. PMID:23050659

  2. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    Directory of Open Access Journals (Sweden)

    Garcia-Rojas Leonardo

    2012-10-01

    Full Text Available Abstract Background To assess the efficacy, clinical outcomes, visual acuity (VA, incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%, 20/60 or better in 12 eyes (92%, and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method.

  3. Comparative analysis of classification based algorithms for diabetes diagnosis using iris images.

    Science.gov (United States)

    Samant, Piyush; Agarwal, Ravinder

    2018-01-01

    Photo-diagnosis is always an intriguing area for the researchers, with the advancement of image processing and computer machine vision techniques it have become more reliable and popular in recent years. The objective of this paper is to study the change in the features of iris, particularly irregularities in the pigmentation of certain areas of the iris with respect to diabetic health of an individual. Apart from the point that iris recognition concentrates on the overall structure of the iris, diagnostic techniques emphasises the local variations in the particular area of iris. Pre-image processing techniques have been applied to extract iris and thereafter, region of interest from the extracted iris have been cropped out. In order to observe the changes in the tissue pigmentation of region of interest, statistical, texture textural and wavelet features have been extracted. At the end, a comparison of accuracies of five different classifiers has been presented to classify two subject groups of diabetic and non-diabetic. Best classification accuracy has been calculated as 89.66% by the random forest classifier. Results have been shown the effectiveness and diagnostic significance of the proposed methodology. Presented piece of work offers a novel systemic perspective of non-invasive and automatic diabetic diagnosis.

  4. Security enhanced BioEncoding for protecting iris codes

    Science.gov (United States)

    Ouda, Osama; Tsumura, Norimichi; Nakaguchi, Toshiya

    2011-06-01

    Improving the security of biometric template protection techniques is a key prerequisite for the widespread deployment of biometric technologies. BioEncoding is a recently proposed template protection scheme, based on the concept of cancelable biometrics, for protecting biometric templates represented as binary strings such as iris codes. The main advantage of BioEncoding over other template protection schemes is that it does not require user-specific keys and/or tokens during verification. Besides, it satisfies all the requirements of the cancelable biometrics construct without deteriorating the matching accuracy. However, although it has been shown that BioEncoding is secure enough against simple brute-force search attacks, the security of BioEncoded templates against more smart attacks, such as record multiplicity attacks, has not been sufficiently investigated. In this paper, a rigorous security analysis of BioEncoding is presented. Firstly, resistance of BioEncoded templates against brute-force attacks is revisited thoroughly. Secondly, we show that although the cancelable transformation employed in BioEncoding might be non-invertible for a single protected template, the original iris code could be inverted by correlating several templates used in different applications but created from the same iris. Accordingly, we propose an important modification to the BioEncoding transformation process in order to hinder attackers from exploiting this type of attacks. The effectiveness of adopting the suggested modification is validated and its impact on the matching accuracy is investigated empirically using CASIA-IrisV3-Interval dataset. Experimental results confirm the efficacy of the proposed approach and show that it preserves the matching accuracy of the unprotected iris recognition system.

  5. Alpha antagonists and intraoperative floppy iris syndrome: A spectrum

    Directory of Open Access Journals (Sweden)

    Sharif A Issa

    2008-07-01

    Full Text Available Sharif A Issa, Omar H Hadid, Oliver Baylis, Margaret DayanDepartment of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UKBackground: To determine occurrence of features of intraoperative floppy iris syndrome (IFIS during cataract surgery in patients taking systemic alpha-antagonists (AA.Methods: We prospectively studied patients on AA and who underwent phacoemulsification. The following were recorded: pupil diameter preoperatively, iris flaccidity, iris prolapse and peroperative miosis.Results: We studied 40 eyes of 31 subjects. Mean age was 78 years. Overall, 14 eyes (13 patients showed signs of IFIS: 9/13 (69% eyes of patients on tamsulosin, 1/18 (6% eyes in the doxazosin group, 2/2 prazosin patients, 1/4 eyes in the indoramin group, and 1/2 eyes in two patients on a combination of doxazosin and tamsulosin. Most cases (92% had only one or two signs of IFIS. Bilateral cataract surgery was undertaken in 9 patients but only one patient (on tamsulosin had features of IFIS in both eyes, while 4 patients (2 on tamsulosin and 2 on other AA showed signs of IFIS in one eye only, and 4 patients did not show IFIS in either eye.Conclusion: Most AA were associated with IFIS, but it tends to present as a spectrum of signs rather than full triad originally described. Tamsulosin was most likely to be associated with IFIS; however, its intake does not necessarily mean that IFIS will occur. For patients on AA, the behavior of the iris intraoperatively in one eye is a poor predictor of the other eye. Surgeons should anticipate the occurrence of IFIS in any patient on AA.Keywords: alpha blocker, alpha antagonist, cataract surgery, intraoperative floppy iris syndrome, tamsulosin.

  6. Relationship of the Van Herick Grading System with Peripheral Iris Configuration and Level of Iris Insertion.

    Science.gov (United States)

    Khan, Faisal Aziz; Niazi, Shafaq Pervez Khan; Khan, Assad Zaman

    2017-09-01

    To determine the relationship of the van Herick angle grading system with the level of iris insertion and peripheral iris configuration. Observational study. Eye department, Combined Military Hospital, Malir Cantt., Karachi, from May to October 2015. Sixty-five eyes of 65 patients were recruited. Anterior chamber depth at the temporal limbus was measured as a fraction of corneal section thickness using van Herick technique and graded on the standard 4-point scale of the van Herick grading system. Gonioscopy of the temporal quadrant was performed with a Posner 4 mirror goniolens and both the true level of iris insertion and peripheral iris configuration were recorded on a 4-point scale so as to equate with the van Herick 4-point grading system. Spearman's rho test was applied to determine the relationship of the van Herick grading system with level of iris root insertion and peripheral iris configuration. Amoderate positive correlation between van Herick grade and peripheral iris configuration was found which was statistically significant (rs=0.42, p < 0.001). Astatistically significant and moderate positive correlation was also detected between van Herick grade and the level of iris insertion (rs=0.45, p < 0.001). The van Herick grade has a moderately positive relationship with the peripheral iris configuration and true level of iris insertion.

  7. Iris's Functional Description using Zernike polynomials

    International Nuclear Information System (INIS)

    Munnoz, D. P.; Silva Mata, F. J.; Talavera, I.; Hernandez, N.; Augier, A.

    2012-01-01

    The main goal of this work is the texture representation of the iris original image by means of functional data. The essence of the method consists in obtaining an adjusted vector of coefficients by means of a least square approximation starting from the representation of the original image by the expansion on the two-dimensional Zernike basis. This type of representation provides remarkable advantages regarding other representations e.g. the appreciable reduction of the dimension of the data, the simplification of the general process of the image and those characteristics of the functional data analysis. The carried out experiments demonstrate the feasibility of this approach and they allowed determining the optimal dimension of the coefficients vectors by means of the minimization of the residual errors. To corroborate the effectiveness of this representation, some experiments on identification were carried out on international databases whose initial results are annexed in the work. (Author)

  8. Secondary Metabolites Isolated from Iris germanica

    Directory of Open Access Journals (Sweden)

    Muhammad I. Choudhary

    2009-06-01

    Full Text Available Phytochemical investigations of methanol extract of rhizome of Iris germanica L. resulted in the isolation of one new compound, 6,6-ditetradecyl-6,7-dihydrooxepin-2(3H-one (1 and five known compounds, 1-(2-(6′-hydroxy-2′-methylcyclohex-1′-enyloxy-5-methoxyphenylethanone (2 4-hydroxy-3-methoxyacetophenone (3, irisolone (4 irisolidone (5 and 2-acetoxy-3,6-dimethoxy-1,4-benzoquinone (6 .The structures of the compounds were determined on the basis of spectroscopic techniques. The antifungal activity of different soluble portions was measured. The hexane soluble portion of the methanol extract showed significant antifungal activity where as the ethyl acetate and chloroform soluble portions showed moderate activity. The methanol extract showed no antifungal activity.

  9. Iris Data Classification Using Quantum Neural Networks

    International Nuclear Information System (INIS)

    Sahni, Vishal; Patvardhan, C.

    2006-01-01

    Quantum computing is a novel paradigm that promises to be the future of computing. The performance of quantum algorithms has proved to be stunning. ANN within the context of classical computation has been used for approximation and classification tasks with some success. This paper presents an idea of quantum neural networks along with the training algorithm and its convergence property. It synergizes the unique properties of quantum bits or qubits with the various techniques in vogue in neural networks. An example application of Fisher's Iris data set, a benchmark classification problem has also been presented. The results obtained amply demonstrate the classification capabilities of the quantum neuron and give an idea of their promising capabilities

  10. The Infrared Imaging Spectrograph (IRIS) for TMT: multi-tiered wavefront measurements and novel mechanical design

    Science.gov (United States)

    Dunn, Jennifer; Andersen, David; Chapin, Edward; Reshetov, Vlad; Wierzbicki, Ramunas; Herriot, Glen; Chalmer, Dean; Isbrucker, Victor; Larkin, James E.; Moore, Anna M.; Suzuki, Ryuji

    2016-08-01

    The InfraRed Imaging Spectrograph (IRIS) will be the first light adaptive optics instrument on the Thirty Meter Telescope (TMT). IRIS is being built by a collaboration between Caltech, the University of California, NAOJ and NRC Herzberg. In this paper we present novel aspects of the Support Structure, Rotator and On-Instrument Wavefront Sensor systems being developed at NRC Herzberg. IRIS is suspended from the bottom port of the Narrow Field Infrared Adaptive Optics System (NFIRAOS), and provides its own image de-rotation to compensate for sidereal rotation of the focal plane. This arrangement is a challenge because NFIRAOS is designed to host two other science instruments, which imposes strict mass requirements on IRIS. As the mechanical design of all elements has progressed, we have been tasked with keeping the instrument mass under seven tonnes. This requirement has resulted in a mass reduction of 30 percent for the support structure and rotator compared to the most recent IRIS designs. To accomplish this goal, while still being able to withstand earthquakes, we developed a new design with composite materials. As IRIS is a client instrument of NFIRAOS, it benefits from NFIRAOS's superior AO correction. IRIS plays an important role in providing this correction by sensing low-order aberrations with three On-Instrument Wavefront Sensors (OIWFS). The OIWFS consists of three independently positioned natural guide star wavefront sensor probe arms that patrol a 2-arcminute field of view. We expect tip-tilt measurements from faint stars within the IRIS imager focal plane will further stabilize the delivered image quality. We describe how the use of On-Detector Guide Windows (ODGWs) in the IRIS imaging detector can be incorporated into the AO correction. In this paper, we present our strategies for acquiring and tracking sources with this complex AO system, and for mitigating and measuring the various potential sources of image blur and misalignment due to properties of

  11. Results of the naive quark model

    International Nuclear Information System (INIS)

    Gignoux, C.

    1987-10-01

    The hypotheses and limits of the naive quark model are recalled and results on nucleon-nucleon scattering and possible multiquark states are presented. Results show that with this model, ropers do not come. For hadron-hadron interactions, the model predicts Van der Waals forces that the resonance group method does not allow. Known many-body forces are not found in the model. The lack of mesons shows up in the absence of a far reaching force. However, the model does have strengths. It is free from spuriousness of center of mass, and allows a democratic handling of flavor. It has few parameters, and its predictions are very good [fr

  12. IRIS Toxicological Review of Thallium and Compounds ...

    Science.gov (United States)

    Thallium compounds are used in the semiconductor industry, the manufacture of optic lenses and low-melting glass, low-temperature thermometers, alloys, electronic devices, mercury lamps, fireworks, and imitation germs, and clinically as an imaging agent in the diagnosis of certain tumors. EPA's assessment of noncancer health effects and carcinogenic potential of thallium compounds was last prepared and added to the IRIS database between 1988 and 1990. The IRIS program is preparing an assessment that will incorporate current health effects information available for thallium and compounds, and current risk assessment methods. The IRIS assessment for thallium compounds will consist of a Toxicological Review and IRIS Summary. The Toxicological Review is a critical review of the physiochemical and toxicokinetic properties of a chemical, and its toxicity in humans and experimental systems. The assessment will present reference values for the noncancer effects of thallium compounds (RfD and Rfc), and a cancer assessment. The Toxicological Review and IRIS Summary have been subject to Agency review, Interagency review, and external scientific peer review. The final product will reflect the Agency opinion on the overall toxicity of thallium and compounds. EPA is undertaking an Integrated Risk Information System (IRIS) health assessment for thallium and compounds. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effec

  13. The concave iris in pigment dispersion syndrome.

    Science.gov (United States)

    Liu, Lance; Ong, Ee Lin; Crowston, Jonathan

    2011-01-01

    To visualize the changes of the iris contour in patients with pigment dispersion syndrome after blinking, accommodation, and pharmacologic miosis using anterior segment optical coherence tomography. Observational case series. A total of 33 eyes of 20 patients with pigment dispersion syndrome. Each eye was imaged along the horizontal 0- to 180-degree meridian using the Visante Anterior Segment Imaging System (Carl Zeiss Meditec, Dublin, CA). Scans were performed at baseline and after focusing on an internal fixation target for 5 minutes, forced blinking, accommodation, and pharmacologic miosis with pilocarpine 2%. Quantitative analysis of the changes in the iris configuration. After 5 minutes of continual fixation, the iris became planar with the mean ± standard deviation curvature decreasing from 214 ± 74 μm to 67 ± 76 μm (P pigment dispersion syndrome after forced blinking, but the iris concavity recovered to 227 ± 113 μm (P = 0.34) and 238 ± 119 μm (P = 0.19) with the -3.0 and -6.0 diopter lenses, respectively. Pilocarpine-induced miosis caused the iris to assume a planar configuration in all subjects. This study shows that the iris in pigment dispersion syndrome assumes a planar configuration when fixating and that the concavity of the iris surface is not restored by blinking. Accommodation restored the iris concavity, suggesting that the posterior curvature of the iris in pigment dispersion syndrome is induced and probably maintained, at least in part, by accommodation. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  14. Scoping Evaluation of the IRIS Radiation Environment by Using the FW-CADIS Method and SCALE MAVRIC Code

    International Nuclear Information System (INIS)

    Petrovic, B.

    2008-01-01

    IRIS is an advanced pressurized water reactor of integral configuration. This integral configuration with its relatively large reactor vessel and thick downcomer (1.7 m) results in a significant reduction of radiation field and material activation. It thus enables setting up aggressive dose reduction objectives, but at the same time presents challenges for the shielding analysis which needs to be performed over a large spatial domain and include flux attenuation by many orders of magnitude. The Monte Carlo method enables accurately representing irregular geometry and potential streaming paths, but may require significant computational efforts to reduce statistical uncertainty within the acceptable range. Variance reduction methods do exist, but they are designed to provide results for individual detectors and in limited regions, whereas in the scoping phase of IRIS shielding analysis the results are sought throughout the whole containment. To facilitate such analysis, the SCALE MAVRIC was employed. Based on the recently developed FW-CADIS method, MAVRIC uses forward and adjoint deterministic transport theory calculations to generate effective biasing parameters for Monte Carlo simulations throughout the problem. Previous studies have confirmed the potential of this method for obtaining Monte Carlo solutions with acceptable statistics over large spatial domains. The objective of this work was to evaluate the capability of the FW-CADIS/MAVRIC to efficiently perform the required shielding analysis of IRIS. For that purpose, a representative model was prepared, retaining the main problem characteristics, i.e., a large spatial domain (over 10 m in each dimension) and significant attenuation (over 12 orders of magnitude), but geometrically rather simplified. The obtained preliminary results indicate that the FW-CADIS method implemented through the MAVRIC sequence in SCALE will enable determination of radiation field throughout the large spatial domain of the IRIS nuclear

  15. SEGMENTATION AND QUALITY ANALYSIS OF LONG RANGE CAPTURED IRIS IMAGE

    Directory of Open Access Journals (Sweden)

    Anand Deshpande

    2016-05-01

    Full Text Available The iris segmentation plays a major role in an iris recognition system to increase the performance of the system. This paper proposes a novel method for segmentation of iris images to extract the iris part of long range captured eye image and an approach to select best iris frame from the iris polar image sequences by analyzing the quality of iris polar images. The quality of iris image is determined by the frequency components present in the iris polar images. The experiments are carried out on CASIA-long range captured iris image sequences. The proposed segmentation method is compared with Hough transform based segmentation and it has been determined that the proposed method gives higher accuracy for segmentation than Hough transform.

  16. IRIS Toxicological Review of Dichloromethane (Methylene ...

    Science.gov (United States)

    EPA has finalized the Toxicological Review of Dichloromethane (Methylene Chloride): In support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health. This document presents background information and justification for the Intergrated Risk Information System (IRIS) Summary of the hazard and dose-response assessment of dichloromethane. IRIS Summaries may include oral reference dose (RfD) and inhalation reference concentration (RfC) values for chronic and other exposure durations, and a carcinogencity assessment. Internet/NCEA web site

  17. FORSTERIAN MODEL OF CHARACTERIZATION AND NON-HUMAN CHARACTERS IN NARRATIVE FICTION: IRIS MURDOCH’S MISTER MARS AND FRANZ KAFKA’S GREGOR SAMSA

    Directory of Open Access Journals (Sweden)

    Barış METE

    2017-06-01

    Full Text Available In Aspects of the Novel, Edward Morgan Forster introduces the critical concepts of flat and round to describe the nature of different types of fictional characters. According to Forster’s theoretical categorization, flat characters are constructed and exist in their fictional realm around a single feature or quality. As this is the key criterion, Forster argues that flat characters can easily be recognized and remembered by the reader. Flat characters remain mostly the same through circumstances. In other words, flat characters never surprise the reader. Contrary to the nature of flat characters, round characters operate in an opposite direction to their counterparts. Round characters never remain the same throughout events, and it is not easy to recognize them since they do not exist under the dominance of a single trait. In addition to these, round characters are those who surprise the reader. Although Forster’s categorisation of fictional characters has functioned well in most of the cases, some characters are not easily analysed under this formula. Franz Kafka’s Gregor Samsa, for example, seems neither a round nor a flat character. Throughout his story, he remains the same. At the same time, he surprises the reader, which is not expected from him since he is mostly the same character in the text. Samsa’s turning into an insect further complicates the definition of his roundness or flatness. Another example is Iris Murdoch’s Mister Mars. Mister Mars is an animal. But at the same time he is a movie star, a celebrity. He has a pivotal role for the protagonist of the text. Therefore, the aim of this study is first to introduce the theoretical background of the nature of fictional characters and then to display some difficulties present particularly in Forster’s classification through the characterisation of two non-human examples.

  18. FAST DISCRETE CURVELET TRANSFORM BASED ANISOTROPIC FEATURE EXTRACTION FOR IRIS RECOGNITION

    Directory of Open Access Journals (Sweden)

    Amol D. Rahulkar

    2010-11-01

    Full Text Available The feature extraction plays a very important role in iris recognition. Recent researches on multiscale analysis provide good opportunity to extract more accurate information for iris recognition. In this work, a new directional iris texture features based on 2-D Fast Discrete Curvelet Transform (FDCT is proposed. The proposed approach divides the normalized iris image into six sub-images and the curvelet transform is applied independently on each sub-image. The anisotropic feature vector for each sub-image is derived using the directional energies of the curvelet coefficients. These six feature vectors are combined to create the resultant feature vector. During recognition, the nearest neighbor classifier based on Euclidean distance has been used for authentication. The effectiveness of the proposed approach has been tested on two different databases namely UBIRIS and MMU1. Experimental results show the superiority of the proposed approach.

  19. A novel iris localization algorithm using correlation filtering

    Science.gov (United States)

    Pohit, Mausumi; Sharma, Jitu

    2015-06-01

    Fast and efficient segmentation of iris from the eye images is a primary requirement for robust database independent iris recognition. In this paper we have presented a new algorithm for computing the inner and outer boundaries of the iris and locating the pupil centre. Pupil-iris boundary computation is based on correlation filtering approach, whereas iris-sclera boundary is determined through one dimensional intensity mapping. The proposed approach is computationally less extensive when compared with the existing algorithms like Hough transform.

  20. Interpreting Results from the Multinomial Logit Model

    DEFF Research Database (Denmark)

    Wulff, Jesper

    2015-01-01

    This article provides guidelines and illustrates practical steps necessary for an analysis of results from the multinomial logit model (MLM). The MLM is a popular model in the strategy literature because it allows researchers to examine strategic choices with multiple outcomes. However, there see...... suitable for both interpretation and communication of results. The pratical steps are illustrated through an application of the MLM to the choice of foreign market entry mode.......This article provides guidelines and illustrates practical steps necessary for an analysis of results from the multinomial logit model (MLM). The MLM is a popular model in the strategy literature because it allows researchers to examine strategic choices with multiple outcomes. However, there seem...... to be systematic issues with regard to how researchers interpret their results when using the MLM. In this study, I present a set of guidelines critical to analyzing and interpreting results from the MLM. The procedure involves intuitive graphical representations of predicted probabilities and marginal effects...

  1. Longitudinal coupling impedance of a thick iris collimator

    International Nuclear Information System (INIS)

    Gluckstern, R.L.; Jiang, S.

    1992-01-01

    A previous calculation of the longitudinal coupling impedance of an iris in a beam pipe turned out not to be well convergent. In this work an alternate basis vector for the matrix equations is constructed, leading to convergent results. Numerical results are presented for the limit a/b → ∞, corresponding to a beam passing through a circular hole in a thick wall. 4 figs., 4 refs

  2. The IRIS Data Management Center: Enabling Access to Observational Time Series Spanning Decades

    Science.gov (United States)

    Ahern, T.; Benson, R.; Trabant, C.

    2009-04-01

    The Incorporated Research Institutions for Seismology (IRIS) is funded by the National Science Foundation (NSF) to operate the facilities to generate, archive, and distribute seismological data to research communities in the United States and internationally. The IRIS Data Management System (DMS) is responsible for the ingestion, archiving, curation and distribution of these data. The IRIS Data Management Center (DMC) manages data from more than 100 permanent seismic networks, hundreds of temporary seismic deployments as well as data from other geophysical observing networks such as magnetotelluric sensors, ocean bottom sensors, superconducting gravimeters, strainmeters, surface meteorological measurements, and in-situ atmospheric pressure measurements. The IRIS DMC has data from more than 20 different types of sensors. The IRIS DMC manages approximately 100 terabytes of primary observational data. These data are archived in multiple distributed storage systems that insure data availability independent of any single catastrophic failure. Storage systems include both RAID systems of greater than 100 terabytes as well as robotic tape robots of petabyte capacity. IRIS performs routine transcription of the data to new media and storage systems to insure the long-term viability of the scientific data. IRIS adheres to the OAIS Data Preservation Model in most cases. The IRIS data model requires the availability of metadata describing the characteristics and geographic location of sensors before data can be fully archived. IRIS works with the International Federation of Digital Seismographic Networks (FDSN) in the definition and evolution of the metadata. The metadata insures that the data remain useful to both current and future generations of earth scientists. Curation of the metadata and time series is one of the most important activities at the IRIS DMC. Data analysts and an automated quality assurance system monitor the quality of the incoming data. This insures data

  3. IRIS Bimonthly Public Meeting (Oct 2014)

    Science.gov (United States)

    The meeting was held to obtain input from the scientific community and the public on studies and data that will be used in the assessments of Diisononyl Phthalate (DINP) and Hexavalent Chromium (Cr(VI)) that are under IRIS development.

  4. IRIS Bimonthly Public Meeting (Apr 2014)

    Science.gov (United States)

    EPA hosted a public meeting/webinar to provide an opportunity for the public to give input and participate in an open discussion regarding several IRIS chemical assessments for Diethyl Phthalate (DEP) and Hexabromocyclododecane (HBCD).

  5. An Application for Descriptive Nearness: Iris Recognition

    Directory of Open Access Journals (Sweden)

    Polat Kadirhan

    2017-12-01

    Full Text Available Near Set Theory has various applications in the literature. In this paper, using the concept descriptive nearness, we show how to perform iris recognition. This process has a few algorithms given via Mathematica Script Language.

  6. Constructing New Biorthogonal Wavelet Type which Matched for Extracting the Iris Image Features

    International Nuclear Information System (INIS)

    Isnanto, R Rizal; Suhardjo; Susanto, Adhi

    2013-01-01

    Some former research have been made for obtaining a new type of wavelet. In case of iris recognition using orthogonal or biorthogonal wavelets, it had been obtained that Haar filter is most suitable to recognize the iris image. However, designing the new wavelet should be done to find a most matched wavelet to extract the iris image features, for which we can easily apply it for identification, recognition, or authentication purposes. In this research, a new biorthogonal wavelet was designed based on Haar filter properties and Haar's orthogonality conditions. As result, it can be obtained a new biorthogonal 5/7 filter type wavelet which has a better than other types of wavelets, including Haar, to extract the iris image features based on its mean-squared error (MSE) and Euclidean distance parameters.

  7. Reparative processes of the iris after irradiation with the argon-ion laser

    International Nuclear Information System (INIS)

    Huber, G.K.; Zypen, E. van der; Fankhauser, F.

    1979-01-01

    The reparative processes of the pigmented iris of the rabbit were analysed with ultrastructural methods. Clearing of the damaged area by macrophages is the first step in the reparative processes. Clump cells are macrophages which are observed from the first day of the injury until the ninth week. Repair of the anterior surface of the iris is largely finished after 32 days. The repair of collagenous fibres reaches its maximum activity 32 days after irradiation. The pigment epithelium has only an insignificant regeneration potential. Irradiation of the iris by the argon-ion laser results in an atropic, hyperpigmented scar. The rapid regeneration of a lesion induced by the argon-ion laser in the rabbit iris casts doubt as to whether this method could be applied to the human eye with equal success. (orig.) 891 AJ/orig. 892 MB

  8. Reducing Error Rates for Iris Image using higher Contrast in Normalization process

    Science.gov (United States)

    Aminu Ghali, Abdulrahman; Jamel, Sapiee; Abubakar Pindar, Zahraddeen; Hasssan Disina, Abdulkadir; Mat Daris, Mustafa

    2017-08-01

    Iris recognition system is the most secured, and faster means of identification and authentication. However, iris recognition system suffers a setback from blurring, low contrast and illumination due to low quality image which compromises the accuracy of the system. The acceptance or rejection rates of verified user depend solely on the quality of the image. In many cases, iris recognition system with low image contrast could falsely accept or reject user. Therefore this paper adopts Histogram Equalization Technique to address the problem of False Rejection Rate (FRR) and False Acceptance Rate (FAR) by enhancing the contrast of the iris image. A histogram equalization technique enhances the image quality and neutralizes the low contrast of the image at normalization stage. The experimental result shows that Histogram Equalization Technique has reduced FRR and FAR compared to the existing techniques.

  9. Novel Iris Biometric Watermarking Based on Singular Value Decomposition and Discrete Cosine Transform

    Directory of Open Access Journals (Sweden)

    Jinyu Lu

    2014-01-01

    Full Text Available A novel iris biometric watermarking scheme is proposed focusing on iris recognition instead of the traditional watermark for increasing the security of the digital products. The preprocess of iris image is to be done firstly, which generates the iris biometric template from person's eye images. And then the templates are to be on discrete cosine transform; the value of the discrete cosine is encoded to BCH error control coding. The host image is divided into four areas equally correspondingly. The BCH codes are embedded in the singular values of each host image's coefficients which are obtained through discrete cosine transform (DCT. Numerical results reveal that proposed method can extract the watermark effectively and illustrate its security and robustness.

  10. SURVEY OF BIOMETRIC SYSTEMS USING IRIS RECOGNITION

    OpenAIRE

    S.PON SANGEETHA; DR.M.KARNAN

    2014-01-01

    The security plays an important role in any type of organization in today’s life. Iris recognition is one of the leading automatic biometric systems in the area of security which is used to identify the individual person. Biometric systems include fingerprints, facial features, voice recognition, hand geometry, handwriting, the eye retina and the most secured one presented in this paper, the iris recognition. Biometric systems has become very famous in security systems because it is not possi...

  11. Iris en sayuela signo clínico nuevo asociado al síndrome tóxico del segmento anterior: a new clinical sign associated to the anterior segment toxic syndrome Iris in underskirt

    Directory of Open Access Journals (Sweden)

    Iván Hernández López

    2010-01-01

    Full Text Available OBJETIVO: Presentar un nuevo signo clínico como resultado del desprendimiento gigante del epitelio pigmentado posterior del iris en el curso de un síndrome tóxico del segmento anterior tras una cirugía de catarata. MÉTODOS: Presentamos un paciente intervenido de catarata mediante facoemulsificación con implante de lente intraocular de cámara posterior plegable, sin incidencias ni complicaciones transoperatorias. Se le realizó evaluación biomicroscópica en el posoperatorio inmediato diagnosticándosele un síndrome tóxico del segmento anterior asociado a un desprendimiento gigante del epitelio pigmentado posterior del iris. Se tomaron fotos durante la evolución del paciente para documentar este raro signo clínico. RESULTADOS: Al provocar la dilatación pupilar farmacológica nos encontramos con la retracción de todas las capas anteriores del iris, mostrando por debajo al epitelio pigmentado posterior del iris sinequiado al lente intraocular y tan extensamente desprendido que simulaba un segundo iris. No encontramos este hallazgo clínico reportado en la literatura revisada. Denominamos este signo como iris en sayuela. CONCLUSIONES: El desprendimiento del epitelio pigmentado posterior del iris constituye un hallazgo clínico que puede aparecer raramente asociado al síndrome tóxico del segmento anterior y cuando es muy extenso puede presentarse de forma insólita como el signo del iris en sayuela.OBJECTIVE: To present a new clinical sign as a result of a huge posterior pigmented epithelium detachment of the iris in the course of at toxic anterior segment syndrome after a successful cataract surgery. METHOD: A patient who had undergone a cataract surgery by phacoemulsification with posterior chamber foldable intraocular lens implantation, without any incidence or transoperative complication. He was evaluated through biomicroscopy in the immediate postoperative period where a huge posterior pigmented epithelium detachment of the iris

  12. INPRO economic assessment of the IRIS nuclear reactor for deployment in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves Filho, Orlando Joao Agostinho, E-mail: orlando@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN - RJ), Rua Helio de Almeida, 75, Cidade Universitaria, Ilha do Fundao, 21941-906 Rio de Janeiro, RJ (Brazil)

    2011-06-15

    Highlights: > First INPRO evaluation of IRIS economic competitiveness for deployment in Brazil. > Plant arrangement of three independent IRIS single units constructed in series. > Angra 3 reactor used as reference design for judgment of IRIS economic potential. > IRIS economically competes with 2nd generation nuclear power plants in Brazil - Abstract: This paper presents the results of the economic assessment of the International Reactor Innovative and Secure (IRIS) for deployment in Brazil using the assessment methodology developed under the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO), co-ordinated by the International Atomic Energy Agency (IAEA). INPRO initiated in 2001 and has the main objective of helping to ensure that nuclear energy will be available to contribute in a sustainable manner to the energy needs of the 21st century. Among its missions is the development of a methodology to assess innovative nuclear energy systems (INSs) on a global, regional and national basis. In 2005, Brazil submitted a proposal for the assessment of two small-size reactors as components of an INS, completed with a conventional open nuclear fuel cycle based on enriched uranium. One of the reactors assessed was IRIS, a small-size, modular, integral-type PWR reactor. IRIS was evaluated with regard to the areas of reactor safety and economics only. This paper outlines the rationale for the study and summarizes the results of the economic assessment. The study concluded that the reference design of IRIS complies with most of INPRO economics criteria and has potential to comply with the remaining ones.

  13. Parallel-Bit Stream for Securing Iris Recognition

    OpenAIRE

    Elsayed Mostafa; Maher Mansour; Heba Saad

    2012-01-01

    Biometrics-based authentication schemes have usability advantages over traditional password-based authentication schemes. However, biometrics raises several privacy concerns, it has disadvantages comparing to traditional password in which it is not secured and non revocable. In this paper, we propose a fast method for securing revocable iris template using parallel-bit stream watermarking to overcome these problems. Experimental results prove that the proposed method has low computation time ...

  14. Results of steel containment vessel model test

    International Nuclear Information System (INIS)

    Luk, V.K.; Ludwigsen, J.S.; Hessheimer, M.F.; Komine, Kuniaki; Matsumoto, Tomoyuki; Costello, J.F.

    1998-05-01

    A series of static overpressurization tests of scale models of nuclear containment structures is being conducted by Sandia National Laboratories for the Nuclear Power Engineering Corporation of Japan and the US Nuclear Regulatory Commission. Two tests are being conducted: (1) a test of a model of a steel containment vessel (SCV) and (2) a test of a model of a prestressed concrete containment vessel (PCCV). This paper summarizes the conduct of the high pressure pneumatic test of the SCV model and the results of that test. Results of this test are summarized and are compared with pretest predictions performed by the sponsoring organizations and others who participated in a blind pretest prediction effort. Questions raised by this comparison are identified and plans for posttest analysis are discussed

  15. Spectral sensitivity of the photointrinsic iris in the red-eared slider turtle (Trachemys scripta elegans).

    Science.gov (United States)

    Sipe, Grayson O; Dearworth, James R; Selvarajah, Brian P; Blaum, Justin F; Littlefield, Tory E; Fink, Deborah A; Casey, Corinne N; McDougal, David H

    2011-01-01

    Our goal in this study was to examine the red-eared slider turtle for a photomechanical response (PMR) and define its spectral sensitivity. Pupils of enucleated eyes constricted to light by ∼11%, which was one-third the response measured in alert behaving turtles at ∼33%. Rates of constriction in enucleated eyes that were measured by time constants (1.44-3.70 min) were similar to those measured in turtles at 1.97 min. Dilation recovery rates during dark adaptation for enucleated eyes were predicted using line equations and computed times for reaching maximum sizes between 26 and 44 min. Times were comparable to the measures in turtles where maximum pupil size occurred within 40 min and possessed a time constant of 12.78 min. Hill equations were used to derive irradiance threshold values from enucleated hemisected eyes and then plot a spectral sensitivity curve. The analysis of the slopes and maximum responses revealed contribution from at least two different photopigments, one with a peak at 410 nm and another with a peak at 480 nm. Fits by template equations suggest that contractions are triggered by multiple photopigments in the iris including an opsin-based visual pigment and some other novel photopigment, or a cryptochrome with an absorbance spectrum significantly different from that used in our model. In addition to being regulated by retinal feedback via parasympathetic nervous pathways, the results support that the iris musculature is photointrinsically responsive. In the turtle, the control of its direct pupillary light response (dPLR) includes photoreceptive mechanisms occurring both in its iris and in its retina. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. Microarray Analysis of Iris Gene Expression in Mice with Mutations Influencing Pigmentation

    Science.gov (United States)

    Trantow, Colleen M.; Cuffy, Tryphena L.; Fingert, John H.; Kuehn, Markus H.

    2011-01-01

    Purpose. Several ocular diseases involve the iris, notably including oculocutaneous albinism, pigment dispersion syndrome, and exfoliation syndrome. To screen for candidate genes that may contribute to the pathogenesis of these diseases, genome-wide iris gene expression patterns were comparatively analyzed from mouse models of these conditions. Methods. Iris samples from albino mice with a Tyr mutation, pigment dispersion–prone mice with Tyrp1 and Gpnmb mutations, and mice resembling exfoliation syndrome with a Lyst mutation were compared with samples from wild-type mice. All mice were strain (C57BL/6J), age (60 days old), and sex (female) matched. Microarrays were used to compare transcriptional profiles, and differentially expressed transcripts were described by functional annotation clustering using DAVID Bioinformatics Resources. Quantitative real-time PCR was performed to validate a subset of identified changes. Results. Compared with wild-type C57BL/6J mice, each disease context exhibited a large number of statistically significant changes in gene expression, including 685 transcripts differentially expressed in albino irides, 403 in pigment dispersion–prone irides, and 460 in exfoliative-like irides. Conclusions. Functional annotation clusterings were particularly striking among the overrepresented genes, with albino and pigment dispersion–prone irides both exhibiting overall evidence of crystallin-mediated stress responses. Exfoliative-like irides from mice with a Lyst mutation showed overall evidence of involvement of genes that influence immune system processes, lytic vacuoles, and lysosomes. These findings have several biologically relevant implications, particularly with respect to secondary forms of glaucoma, and represent a useful resource as a hypothesis-generating dataset. PMID:20739468

  17. Phakic iris-fixated intraocular lens placement in the anterior chamber: effects on aqueous flow.

    Science.gov (United States)

    Repetto, Rodolfo; Pralits, Jan O; Siggers, Jennifer H; Soleri, Paolo

    2015-05-01

    Phakic intraocular lenses (pIOLs) are used for correcting vision; in this paper we investigate the fluid dynamical effects of an iris-fixated lens in the anterior chamber. In particular, we focus on changes in the wall shear stress (WSS) on the cornea and iris, which could be responsible for endothelial and pigment cell loss, respectively, and also on the possible increase of the intraocular pressure, which is known to correlate with the incidence of secondary glaucoma. We use a mathematical model to study fluid flow in the anterior chamber in the presence of a pIOL. The governing equations are solved numerically using the open source software OpenFOAM. We use an idealized standard geometry for the anterior chamber and a realistic geometric description of the pIOL. We consider separately the main mechanisms that produce fluid flow in the anterior chamber. The numerical simulations allow us to obtain a detailed description of the velocity and pressure distribution in the anterior chamber, and indicated that implantation of the pIOL significantly modifies the fluid dynamics in the anterior chamber. However, lens implantation has negligible influence on the intraocular pressure and does not produce a significant increase of the shear stress on the cornea, while the shear stress on the iris, although increased, is not enough to cause detachment of cells. We conclude that alterations in the fluid dynamics in the anterior chamber as a result of lens implantation are unlikely to be the cause of medical complications associated with its use.

  18. The EURAD model: Design and first results

    International Nuclear Information System (INIS)

    1989-01-01

    The contributions are abridged versions of lectures delivered on the occasion of the presentation meeting of the EURAD project on the 20th and 21st of February 1989 in Cologne. EURAD stands for European Acid Deposition Model. The project takes one of the possible and necessary ways to search for scientific answers to the questions which the modifications of the atmosphere caused by anthropogenic influence raise. One of the objectives is to develop a realistic numeric model of long-distance transport of harmful substances in the troposphere over Europe and to use this model for the investigation of pollutant distribution but also for the support of their experimental study. The EURAD Model consists of two parts: a meteorologic mesoscale model and a chemical transport model. In the first part of the presentation, these parts are introduced and questions concerning the implementation of the entire model on the computer system CRAY X-MP/22 discussed. Afterwards it is reported upon the results of the test calculations for the cases 'Chernobyl' and 'Alpex'. Thereafter selected problems concerning the treatments of meteorological and air-chemistry processes as well as the parametrization of subscale processes within the model are discussed. The conclusion is made by two lectures upon emission evaluations and emission scenarios. (orig./KW) [de

  19. A physiological production model for cacao : results of model simulations

    NARCIS (Netherlands)

    Zuidema, P.A.; Leffelaar, P.A.

    2002-01-01

    CASE2 is a physiological model for cocoa (Theobroma cacao L.) growth and yield. This report introduces the CAcao Simulation Engine for water-limited production in a non-technical way and presents simulation results obtained with the model.

  20. Maintenance Cycle Extension in the IRIS Advanced Light Water Reactor Plant Design

    International Nuclear Information System (INIS)

    Galvin, Mark R.; Todreas, Neil E.; Conway, Larry E.

    2003-01-01

    New nuclear power generation in the United States will be realized only if the economic performance can be made competitive with other methods of electrical power generation. The economic performance of a nuclear power plant can be significantly improved by increasing the time spent on-line generating electricity relative to the time spent off-line conducting maintenance and refueling. Maintenance includes planned actions (surveillances) and unplanned actions (corrective maintenance) to respond to component degradation or failure. A methodology is described that can be used to resolve, in the design phase, maintenance-related operating cycle length barriers. A primary goal was to demonstrate the applicability and utility of the methodology in the context of the International Reactor, Innovative and Secure (IRIS) design. IRIS is an advanced light water nuclear power plant that is being designed to maximize this on-line generating time by increasing the operating cycle length. This is consequently a maintenance strategy paper using the IRIS plant as the example.Potential IRIS operating cycle length maintenance-related barriers, determined by modification of an earlier operating pressurized water reactor (PWR) plant cycle length analysis to account for differences between the design of IRIS and this operating PWR, are presented. The proposed methodology to resolve these maintenance-related barriers by the design process is described. The results of applying the methodology to two potential IRIS cycle length barriers, relief valve testing and emergency heat removal system testing, are presented

  1. Association between iris constitution and apolipoprotein e gene polymorphism in hypertensives.

    Science.gov (United States)

    Um, Jae-Young; Hwang, Chung-Yeon; Hwang, Woo-Jun; Kang, Sung-Do; Do, Keum-Rok; Cho, Ju-Jang; Cho, Jae-Woon; Kim, Sung-Hoon; Shin, Tae-Yong; Kim, Yun-Kyung; Kim, Hyung-Min; Hong, Seung-Heon

    2004-12-01

    Iridology is a complementary and alternative medicine (CAM) that involves the diagnosis of medical conditions by noting irregularities of the pigmentation in the iris. Iris constitution has a strong familial aggregation and heredity is implicated. Apolipoprotein E (apoE) gene polymorphism is one of the most well-studied genetic markers for vascular diseases, including hypertension. In this study, we investigated the relationship between iris constitution and apoE polymorphism in hypertensives. We classified 87 hypertensives and 79 controls according to iris constitution and determined the apoE genotype of each individual. A significantly higher percentage of individuals with neurogenic constitutions was found in the hypertensive group when compared with the control group (chi(2) = 40.244, p < 0.001). In addition, a neurogenic constitution increased the relative risk for hypertension for subjects with an apo epsilon2 or an epsilon4 allele (chi(2) = 4.086, p = 0.049, odds ratio = 2.633, confidence interval = 1.004-6.905). Our results imply that a neurogenic iris constitution enhances the relative risk for hypertension in subjects with the apo epsilon2 or epsilon4 allele. Furthermore, we attempted to evaluate the efficacy of iris constitutional medicine and to find an association with hypertension.

  2. Spectral analysis software improves confidence in plant and soil water stable isotope analyses performed by isotope ratio infrared spectroscopy (IRIS).

    Science.gov (United States)

    West, A G; Goldsmith, G R; Matimati, I; Dawson, T E

    2011-08-30

    Previous studies have demonstrated the potential for large errors to occur when analyzing waters containing organic contaminants using isotope ratio infrared spectroscopy (IRIS). In an attempt to address this problem, IRIS manufacturers now provide post-processing spectral analysis software capable of identifying samples with the types of spectral interference that compromises their stable isotope analysis. Here we report two independent tests of this post-processing spectral analysis software on two IRIS systems, OA-ICOS (Los Gatos Research Inc.) and WS-CRDS (Picarro Inc.). Following a similar methodology to a previous study, we cryogenically extracted plant leaf water and soil water and measured the δ(2)H and δ(18)O values of identical samples by isotope ratio mass spectrometry (IRMS) and IRIS. As an additional test, we analyzed plant stem waters and tap waters by IRMS and IRIS in an independent laboratory. For all tests we assumed that the IRMS value represented the "true" value against which we could compare the stable isotope results from the IRIS methods. Samples showing significant deviations from the IRMS value (>2σ) were considered to be contaminated and representative of spectral interference in the IRIS measurement. Over the two studies, 83% of plant species were considered contaminated on OA-ICOS and 58% on WS-CRDS. Post-analysis, spectra were analyzed using the manufacturer's spectral analysis software, in order to see if the software correctly identified contaminated samples. In our tests the software performed well, identifying all the samples with major errors. However, some false negatives indicate that user evaluation and testing of the software are necessary. Repeat sampling of plants showed considerable variation in the discrepancies between IRIS and IRMS. As such, we recommend that spectral analysis of IRIS data must be incorporated into standard post-processing routines. Furthermore, we suggest that the results from spectral analysis be

  3. LDPC and SHA based iris recognition for image authentication

    Directory of Open Access Journals (Sweden)

    K. Seetharaman

    2012-11-01

    Full Text Available We introduce a novel way to authenticate an image using Low Density Parity Check (LDPC and Secure Hash Algorithm (SHA based iris recognition method with reversible watermarking scheme, which is based on Integer Wavelet Transform (IWT and threshold embedding technique. The parity checks and parity matrix of LDPC encoding and cancellable biometrics i.e., hash string of unique iris code from SHA-512 are embedded into an image for authentication purpose using reversible watermarking scheme based on IWT and threshold embedding technique. Simply by reversing the embedding process, the original image, parity checks, parity matrix and SHA-512 hash are extracted back from watermarked-image. For authentication, the new hash string produced by employing SHA-512 on error corrected iris code from live person is compared with hash string extracted from watermarked-image. The LDPC code reduces the hamming distance for genuine comparisons by a larger amount than for the impostor comparisons. This results in better separation between genuine and impostor users which improves the authentication performance. Security of this scheme is very high due to the security complexity of SHA-512, which is 2256 under birthday attack. Experimental results show that this approach can assure more accurate authentication with a low false rejection or false acceptance rate and outperforms the prior arts in terms of PSNR.

  4. Lessons learned from IRIS EPO program evaluations

    Science.gov (United States)

    Taber, J.; Hubenthal, M.

    2012-12-01

    Evaluating the overall impact of EPO programs that include activities ranging from formal education through broad public outreach, is a complex issue. The impact of education activities targeted at narrowly defined audiences is generally easier to quantify than the national impact of outreach activities conducted by a relatively small program. For educational activities, our approach has been to leverage the best-practices identified through research and to continuously assess the individual elements internally with the intention of making improvements based on the data generated and the existing research. By constructing our elements on the best practices identified by the research community we feel that internal formative evaluation is a valid means to determine if an activity is effective, particularly when the results are compared to similar programs. For example, effective practices of professional development are well documented in the literature. As a result, this allows us to shape our programs and our evaluations to monitor elements that have been identified as key by the educational research community. Further, such actions allow us to avoid allocating significant resources with the intention of pinning down direct causal relationships between our programs and consumers, when similar interventions (conducted by others) have already shown such relationships. Ongoing review by an EPO advisory committee also provides regular oversight of program impact. While we find internal and external formative evaluation extremely useful in shaping the program and documenting its impact, we also recognize the value of a summative evaluation process. For example, an external summative evaluation of the IRIS EPO program was conducted in 2009, followed by an external panel review, as part of the regular review of IRIS programs. We found that the most valuable part of the external evaluation was our preparation, including clarifying the goals of each of the elements of the

  5. Modelling rainfall erosion resulting from climate change

    Science.gov (United States)

    Kinnell, Peter

    2016-04-01

    It is well known that soil erosion leads to agricultural productivity decline and contributes to water quality decline. The current widely used models for determining soil erosion for management purposes in agriculture focus on long term (~20 years) average annual soil loss and are not well suited to determining variations that occur over short timespans and as a result of climate change. Soil loss resulting from rainfall erosion is directly dependent on the product of runoff and sediment concentration both of which are likely to be influenced by climate change. This presentation demonstrates the capacity of models like the USLE, USLE-M and WEPP to predict variations in runoff and erosion associated with rainfall events eroding bare fallow plots in the USA with a view to modelling rainfall erosion in areas subject to climate change.

  6. Iris autofluorescence in Fuchs' heterochromic uveitis.

    Science.gov (United States)

    Liu, Qian; Jia, Yading; Zhang, Suhua; Xie, Juan; Chang, Xin; Hou, Jia; Li, Gaiyun; Koch, Douglas D; Wang, Li

    2016-10-01

    To explore the characteristic autofluorescence patterns of iris depigmentation in eyes diagnosed with Fuchs' heterochromic uveitis (FHU). Near-infrared autofluorescence images and colour images of iris were taken in 21 eyes of 21 patients with FHU, 30 eyes of 15 normal subjects, 30 eyes of 15 normal age-related iris atrophy and 33 eyes of 20 patients with uveitis other than FHU. The confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph 2, HRA2) was used for melanin-related autofluorescence imaging. The indocyanine green angiography mode of HRA2 was applied for near-infrared laser imaging, and the wavelength of the excitation laser was 795 nm. Iris colour images were also taken with the slit lamp. In normal iris, moderately intense autofluorescence was noted for the pigment ruff at the pupillary border, the crests in the pupillary zone and the collarette; and there was mild autofluorescence in the ciliary zone. In eyes with age-related iris atrophy and uveitis, much less autofluorescence was seen than the healthy normal irides. In eyes with FHU, there was moderate but discontinuous autofluorescence in the pigment ruff, a petaloid pattern of autofluorescence in the pupillary zone, moderate autofluorescence in the collarette and reticular pattern of autofluorescence in the ciliary zone. Characteristic autofluorescence patterns appeared in eyes diagnosed with FHU. Near-infrared autofluorescence is a promising objective technique to document the iris changes in FHU. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. INTRAVAL test case 1b - modelling results

    International Nuclear Information System (INIS)

    Jakob, A.; Hadermann, J.

    1991-07-01

    This report presents results obtained within Phase I of the INTRAVAL study. Six different models are fitted to the results of four infiltration experiments with 233 U tracer on small samples of crystalline bore cores originating from deep drillings in Northern Switzerland. Four of these are dual porosity media models taking into account advection and dispersion in water conducting zones (either tubelike veins or planar fractures), matrix diffusion out of these into pores of the solid phase, and either non-linear or linear sorption of the tracer onto inner surfaces. The remaining two are equivalent porous media models (excluding matrix diffusion) including either non-linear sorption onto surfaces of a single fissure family or linear sorption onto surfaces of several different fissure families. The fits to the experimental data have been carried out by Marquardt-Levenberg procedure yielding error estimates of the parameters, correlation coefficients and also, as a measure for the goodness of the fits, the minimum values of the χ 2 merit function. The effects of different upstream boundary conditions are demonstrated and the penetration depth for matrix diffusion is discussed briefly for both alternative flow path scenarios. The calculations show that the dual porosity media models are significantly more appropriate to the experimental data than the single porosity media concepts. Moreover, it is matrix diffusion rather than the non-linearity of the sorption isotherm which is responsible for the tailing part of the break-through curves. The extracted parameter values for some models for both the linear and non-linear (Freundlich) sorption isotherms are consistent with the results of independent static batch sorption experiments. From the fits, it is generally not possible to discriminate between the two alternative flow path geometries. On the basis of the modelling results, some proposals for further experiments are presented. (author) 15 refs., 23 figs., 7 tabs

  8. 75 FR 25239 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2010-05-07

    ... Information System (IRIS); Announcement of Availability of Literature Searches for IRIS Assessments AGENCY: Environmental Protection Agency. ACTION: Notice; Announcement of availability of literature searches for IRIS... the availability of literature searches for four IRIS assessments and requesting scientific...

  9. Under the hood of IRIS's Distributed REU Site

    Science.gov (United States)

    Hubenthal, M.; Taber, J.

    2014-12-01

    Since 1998 the IRIS Undergraduate Internship Program has provided research experiences for up to 15 students each summer. Through this 9 to 11 week internship program, students take part in an intensive week-long preparatory course, and work with leaders in seismological research, in both lab-base and field-based settings, to produce research products worthy of presentation and recognition at large professional conferences. The IRIS internship program employs a distributed REU model that has been demonstrated to bond students into a cohort, and maintain group cohesion despite students conducting their research at geographically distributed sites. Over the past 16 years the program has encountered numerous anticipated and unanticipated challenges. The primary challenges have involved exploring how to modify the REU-system to produce outcomes that are better aligned with our programmatic goals. For example, some questions we have attempted to address include: How can the success of an REU site be measured? How do you find, interest, and recruit under-represented minorities into a geophysics program? Can the program increase the probability of interns receiving some minimal level of mentoring across the program? While it is likely that no single answer to these questions exists, we have developed and piloted a number of strategies. These approaches have been developed through a process of identifying relevant research results from other REUs and combing this information with data from our own programmatic evaluations. This data informs the development of specific changes within our program which are then measured as a feedback. We will present our current strategies to address each questions along with measures of their effectiveness. In addition to broad scale systematic issues, we have also placed significant effort into responding to smaller, process challenges that all REU sites face. These range from simple logistical issues (e.g. liability), to educational

  10. Prediction of multipactor in the iris region of rf deflecting mode cavities

    Directory of Open Access Journals (Sweden)

    G. Burt

    2011-12-01

    Full Text Available Multipactor is a major cause of field limitation in many superconducting rf cavities. Multipacting is a particular issue for deflecting mode cavities as the typical behavior is not well studied, understood, or parametrized. In this paper an approximate analytical model for the prediction of multipactor in the iris region of deflecting mode cavities is developed. This new but simple model yields a clear explanation on the broad range of rf field levels over which the multipactor can occur. The principle multipactors under investigation here are two-point multipactors associated with cyclotron motion in the cavity’s rf magnetic field. The predictions from the model are compared to numerical simulations and good agreement is obtained. The results are also compared to experimental results previously reported by KEK and are also found in good agreement.

  11. Thermal hydraulic tradeoffs in the design of IRIS primary circuit

    International Nuclear Information System (INIS)

    Oriani, L.; Lombardi, C.; Ricotti, M.E.; Paramonov, D.; Carelli, M.; Conway, L.

    2001-01-01

    IRIS (International Reactor Innovative and Secure) is currently being developed by an international consortium, led by Westinghouse and including universities. In order to achieve high level of safety, reduce complexity and capital cost, and enhance proliferation resistance, an integral primary circuit configuration has been selected. The integral configuration (the core, steam generators, coolant pumps, pressurizer and control rods are all contained within the reactor vessel) has no loop piping and thereby eliminates the possibility of large loss of coolant accidents. If the reactor vessel and components are designed for a very high level of natural circulation, which is promoted by an integral design, the consequence of loss of flow accidents can be significantly reduced or even completely eliminated. Core and integral primary circuit design optimization has been performed using the OSCAR computer code, a specialized tool for the analyses of the IRIS primary system developed at POLIMI. Results of trade-off studies of various in-vessel configurations explored to achieve tight packaging and high serviceability and/or replacement of components such as steam generators and pumps are reported. Effects of changes in secondary side parameters and steam generator design on system efficiency were explored together with the optimization of the vessel and steam generator dimensions and costs. The aim of the trade-off analyses was to limit the design space, and select a reference configuration for the IRIS reactor. (author)

  12. Iris phenotypes and pigment dispersion caused by genes influencing pigmentation.

    Science.gov (United States)

    Anderson, Michael G; Hawes, Norman L; Trantow, Colleen M; Chang, Bo; John, Simon W M

    2008-10-01

    Spontaneous mutations altering mouse coat colors have been a classic resource for discovery of numerous molecular pathways. Although often overlooked, the mouse iris is also densely pigmented and easily observed, thus representing a similarly powerful opportunity for studying pigment cell biology. Here, we present an analysis of iris phenotypes among 16 mouse strains with mutations influencing melanosomes. Many of these strains exhibit biologically and medically relevant phenotypes, including pigment dispersion, a common feature of several human ocular diseases. Pigment dispersion was identified in several strains with mutant alleles known to influence melanosomes, including beige, light, and vitiligo. Pigment dispersion was also detected in the recently arising spontaneous coat color variant, nm2798. We have identified the nm2798 mutation as a missense mutation in the Dct gene, an identical re-occurrence of the slaty light mutation. These results suggest that dysregulated events of melanosomes can be potent contributors to the pigment dispersion phenotype. Combined, these findings illustrate the utility of studying iris phenotypes as a means of discovering new pathways, and re-linking old ones, to processes of pigmented cells in health and disease.

  13. Developing virtual REU cohorts: Reflections from the IRIS Undergraduate Internship Program

    Science.gov (United States)

    Hubenthal, M.; Taber, J.; Aster, R.; Frassetto, A.

    2007-12-01

    Beginning in 2006, the IRIS Education and Outreach program received funding from the National Science Foundation (EAR-0453427) to explore a novel approach to the traditional Research Experience for Undergraduates (REU) model. This model blends the spirit of an REU program, which traditionally hosts participants in one location with successful prior IRIS experience hosting students at widely separated institutions to participate in summer research. A unique feature the IRIS Undergraduate Internship Program is that throughout the summer, interns form and sustain a virtual community, offering assistance, sharing ideas, asking questions, and relaying life experiences while conducting their research at diverse institutions. Key to IRIS's REU model is a combination of: one-on-one mentoring by researchers at IRIS institutions across the US, developing a strong unity among interns through both face-to-face and on-line interactions, participation of an IRIS REU alumni mentor to provide both group and intern-specific guidance developing interns' abilities to self-evaluate and work independently, through carefully designed web-based tools, and increasing interns' awareness of the IRIS and broader Earth Science community; demonstrating the role they will play in this larger community. Virtual interaction is facilitated by 1) bringing students together for face-to-face contact, through a week long orientation held annually at the IRIS PASSCAL Instrument Center on the campus of the New Mexico Institute of Mining and Technology, and 2) the community enabling web infrastructure at http://www.iris.edu/internship/. During the orientation students engage in classes in geophysics basics, career preparation, as well as training to communicate virtually. Our experiences and evaluations from the 2006 and 2007 field seasons have:shown the increasing demand for electronic advertising of REU programs, provided support for several assumptions of the model including the key role of both the

  14. International Reactor Innovative and Secure (IRIS) summary

    International Nuclear Information System (INIS)

    Carelli, Mario D.

    2001-01-01

    The IRIS (International Reactor Innovative and Secure) reactor is described in the first part of the presentation. IRIS is a light water cooled reactor with an integral configuration, where steam generators, pumps and pressurizer are inside the reactor vessel. Partially funded by the DOE NERI program, IRIS is being developed by an international consortium of 16 organizations from seven countries. A key IRIS characteristic is its 'safety by design' approach which strives to eliminate, by design, as many accidents as possible rather than coping with their consequences. Initial returns are very positive; out of the eight Class IV accidents considered in the AP600 only one remains as a Class IV in IRIS, and at much reduced probability. Small-to-medium LOCAs have minimal consequences as the core remains safely under water for days, without the need for safety injection or water makeup. In spite of its novelty IRIS is firmly grounded on proven LWR technology and therefore a prototype is not needed to assure design certification. Rather, very extensive scaled tests will be performed to investigate the performance of in-vessel components such as steam generators and pumps, both individually and as interactive systems. Accident sequences will also be simulated and tested to prove IRIS safety by design claims. The first core fuel is less than 5% enriched and the fuel assembly is very similar to existing PWR assemblies, so there is no licensing challenge regarding the fuel. Because of the safety by design approach, yielding simplifications In design and accident management (e.g., IRIS does not have an emergency core cooling system), some accident scenarios are eliminated and others have lesser consequences. Thus, simplification and streamlining of the regulatory process might be possible. Risk informed regulation will be coupled with safety by design to show lower accident and damage probabilities. This could lead to a relaxation of siting regulatory requirements. It is

  15. Balloon cell nevus of the iris.

    Science.gov (United States)

    Morcos, Mohib W; Odashiro, Alexandre; Bazin, Richard; Pereira, Patricia Rusa; O'Meara, Aisling; Burnier, Miguel N

    2014-12-01

    Balloon cell nevus is a rare histopathological lesion characterized by a predominance of large, vesicular and clear cells, called balloon cells. There is only 1 case of balloon cell nevus of the iris reported in the literature. A 55 year-old man presented a pigmented elevated lesion in the right iris since the age of 12 years old. The lesion had been growing for the past 2 years and excision was performed. Histopathological examination showed a balloon cell nevus composed of clear and vacuolated cells without atypia. A typical spindle cell nevus of the iris was also observed. The differential diagnosis included xanthomatous lesions, brown adipocyte or other adipocytic lesions, clear cell hidradenoma, metastatic clear cell carcinoma of the kidney and clear cell sarcoma. The tumor was positive for Melan A, S100 protein and HMB45. Balloon cell nevus of the iris is rare but should be considered in the differential diagnosis of melanocytic lesions of the iris. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. Uso de la triamcinolona subtenoniana en pacientes con rubeosis del iris Use of intravitreal triamcinolone in patients with iris rubeosis

    Directory of Open Access Journals (Sweden)

    Irene Rojas Rondón

    2008-12-01

    Full Text Available OBJETIVO: Describir el comportamiento de la rubeosis del iris luego de la aplicación de triamcinolona subtenoniana. MÉTODOS: Se realizó un estudio descriptivo de corte longitudinal con 25 pacientes para un total de 32 ojos con diferentes afecciones oculares. Se efectuaron pruebas estadísticas con las variables del estudio y en algunas se utilizó la prueba de los signos de comparación para datos pareados y en otras se aplicó chi cuadrado. Se caracterizaron las variables: edad, sexo, causa de rubeosis del iris y sus estadios, síntomas y tratamiento con láser de panfotocoagulación retiniana. RESULTADOS: La retinopatía diabética proliferativa fue la afección más frecuente en el 76 % de los pacientes, seguida de la oclusión de la vena central retiniana. Del total de pacientes tratados, el 37,5 % evolucionó satisfactoriamente el estado de la rubeosis del iris. Fue mayor el número de pacientes que mejoraron el grado de la rubeosis con tratamiento combinado de láser y triamcinolona subtenoniana, aunque estadísticamente no fue significativo. El estado de la rubeosis mejoró en más de la mitad de los pacientes con tiempo de evolución menor de 6 meses. En aquellos con un tiempo mayor de 6 meses y neovascularización del iris grado III, se pudo estabilizar el glaucoma neovascular. CONCLUSIÓN: Se plantea que la triamcinolona subtenoniana constituye una alternativa para el manejo de este tipo de pacientes.OBJECTIVE: To describe the behaviour of iris rubeosis after using intravitreal triamcinolone. METHODS: A longitudinal descriptive study was performed on 25 patients for a total number of 32 eyes with several ocular diseases. Statistical tests were made with the study variables; sign comparison for paired data and Chi square tests were applied. The variables were age, sex, cause of iris rubeosis and its staging, symptoms and treatment with retinal photocoagulation laser. RESULTS: Proliferative diabetic retinopathy was the most common

  17. Assessment of Urbanization on the Integrated Land-Ocean-Atmosphere Environment in Coastal Metropolis in Preparation for HyspIRI

    Science.gov (United States)

    Sequera, Pedro; McDonald, Kyle C.; Gonzalez, Jorge; Arend, Mark; Krakauer, Nir; Bornstein, Robert; Luvll, Jeffrey

    2012-01-01

    The need for comprehensive studies of the relationships between past and projected changes of regional climate and human activity in comple x urban environments has been well established. The HyspIRI preparato ry airborne activities in California, associated science and applicat ions research, and eventually HyspIRI itself provide an unprecedented opportunity for development and implementation of an integrated data and modeling analysis system focused on coastal urban environments. We will utilize HyspIRI preparatory data collections in developing ne w remote sensing-based tools for investigating the integrated urban e nvironment, emphasizing weather, climate, and energy demands in compl ex coastal cities.

  18. Lipopolysaccharide preconditioning protects hepatocytes from ischemia/reperfusion injury (IRI through inhibiting ATF4-CHOP pathway in mice.

    Directory of Open Access Journals (Sweden)

    Jianhua Rao

    Full Text Available BACKGROUND: Low-dose lipopolysaccharide (LPS preconditioning-induced liver protection has been demonstrated during ischemia-reperfusion injury (IRI in several organs but has not been sufficiently elucidated underlying causal mechanism. This study investigated the role of low-dose LPS preconditioning on ATF4-CHOP pathway as well as the effects of the pathway on tissue injury and inflammation in a mouse model of liver partial-warm IRI. METHODS: LPS (100 µg/kg/d was injected intraperitoneally two days before ischemia. Hepatic injury was evaluated based on serum alanine aminotransferase levels, histopathology, and caspase-3 activity. The ATF4-CHOP pathway and its related apoptotic molecules were investigated after reperfusion. The role of LPS preconditioning on apoptosis and ATF4-CHOP pathway was examined in vitro. Moreover, the effects of the ATF4-CHOP pathway on apoptosis, Caspase-12, and Caspase-3 were determined with ATF4 small interfering RNA (siRNA. Inflammatory cytokine expression was also checked after reperfusion. Inflammatory cytokines and related signaling pathways were analyzed in vitro in macrophages treated by LPS preconditioning or ATF4 siRNA. RESULTS: LPS preconditioning significantly attenuated liver injury after IRI. As demonstrated by in vitro experiments, LPS preconditioning significantly reduced the upregulation of the ATF4-CHOP pathway and inhibited Caspase-12 and Caspase-3 activation after IRI. Later experiments showed that ATF4 knockdown significantly suppressed CHOP, cleaved caspase-12 and caspase-3 expression, as well as inhibited hepatocellular apoptosis. In addition, in mice pretreated with LPS, TNF-α and IL-6 were inhibited after reperfusion, whereas IL-10 was upregulated. Similarly, low-dose LPS significantly inhibited TNF-α, IL-6, ATF4-CHOP pathway, NF-κB pathway, and ERK1/2 in high-dose LPS-stimulated macrophages, whereas IL-10 and cytokine signaling (SOCS-3 suppressor were induced. Importantly, ATF4 siRNA is

  19. AHMCT Intelligent Roadway Information System (IRIS) technical support and testing

    Science.gov (United States)

    2011-12-31

    This report documents the research project AHMCT IRIS Technical Support and Testing, : performed under contract 65A0275, Task ID 1777. It presents an overview of the Intelligent : Roadway Information System (IRIS), and its design and function. ...

  20. Comparison of features response in texture-based iris segmentation

    CSIR Research Space (South Africa)

    Bachoo, A

    2009-03-01

    Full Text Available the Fisher linear discriminant and the iris region of interest is extracted. Four texture description methods are compared for segmenting iris texture using a region based pattern classification approach: Grey Level Co-occurrence Matrix (GLCM), Discrete...

  1. Changes of the eye optics after iris constriction

    Directory of Open Access Journals (Sweden)

    Robert Montés-Micó

    2010-10-01

    Conclusion: Iris constriction slightly modifies the optics of the eye. The small hyperopic shift of the best image plane after iris constriction may be explained by a change in the lens shape and/or position.

  2. IRIS Toxicological Review of Tetrahydrofuran (THF) (Interagency Science Discussion Draft)

    Science.gov (United States)

    EPA is releasing the draft report, Toxicological Review of Tetrahydrofuran, that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the iris/process.htm">IRIS Assessment Development Proc...

  3. IRIS Assessment Plan for Uranium (Scoping and Problem Formulation Materials)

    Science.gov (United States)

    In January 2018, EPA released the IRIS Assessment Plan for Uranium (Oral Reference Dose) (Scoping and Problem Formulation Materials). An IRIS Assessment Plan (IAP) communicates to the public the plan for assessing each individual chemical and includes summary informatio...

  4. IRIS Toxicological Review of Vinyl Chloride (Final Report, 2000)

    Science.gov (United States)

    EPA is announcing the release of the final report, Toxicological Review of Vinyl Chloride: in support of the Integrated Risk Information System (IRIS). The updated Summary for Vinyl Chloride and accompanying Quickview have also been added to the IRIS Database.

  5. Proceedings of the IRI task force activity 2000

    International Nuclear Information System (INIS)

    Radicella, Sandro M.

    2001-05-01

    This internal report of the International Center for Theoretical Physics (ICTP) contains presentations delivered during the International Reference Ionosphere Task Force Activity 2000 which took place at the Abdus Salam ICTP during July 2000. The 2000 Task Force Activity is the seventh successful encounter of specialists organized by the URSI-COSPAR IRI Working Group and the Aeronomy and Radiopropagation Laboratory of the ICTP of Trieste, Italy. The main topic of this task force activity was the modeling of the topside ionosphere and the development of strategies for modeling of ionospheric variability

  6. Bilateral acute iris transillumination: Case report

    Directory of Open Access Journals (Sweden)

    Cumali Degirmenci

    2016-04-01

    Full Text Available Bilateral acute iris transillumination (BAIT is a recently defined disease characterized with bilateral acute, severe pigment dispersion of iris and pupil sphincter paralysis. The etiopathogenesis of the disease is unknown, but antibiotics such as moxifloxacin, clarithromycin, viral infections, and fumigation therapies were considered as probable etiologic factors. A 33-year-old female was referred to our clinic for acute iridocyclitis refractory to azathioprine, colchicum and corticosteroid treatments. Ophthalmic examination revealed bilateral pigment dispersion, significant iris transillumination, heavy pigment deposition in iridocorneal angle, and elevated intraocular pressure. Upon systemic evaluation she was found to have bacterial urinary tract infection. BAIT is an important cause of pigment dispersion and clinicians must be vigilant for this condition to avoid unnecessary diagnostic tests and treatment.

  7. Internet Renewable energy Information System (IRIS)

    DEFF Research Database (Denmark)

    Bäurle, Britta; Nielsen, Vilhjalmur; Ménard, Lionel

    1999-01-01

    Even though the Internet is now a widely accessible data source, the unorganised flood of information makes a specific request e.g. for renewable energy products inefficient. In addition, existing databases on renewable energies are often old and incomplete. The objective of IRIS has been...... to organise and retrieve renewable energy product information on the Internet instead of collecting it manually. Updating coincides with the self interestself-interest of manufacturers to present their latest renewable energy products on their own HTML documents. IRIS is based on a set of powerful tools...... and intends to find, extract, collect and index HTML documents with standardised META tags that are widely spread across web servers on the Internet. This paper presents the structure of IRIS, the software tools, and gives one example of how to categorise and prepare web-sites with product information...

  8. RECENT DEVELOPMENTS OF THE IRIS PROJECT OF INTEREST FOR LATIN AMERICA

    International Nuclear Information System (INIS)

    Carelli, M.D.; Petrovic, B.

    2004-01-01

    The IRIS (International Reactor Innovative and Secure) reactor design is being developed by an international consortium of 21 organizations from ten countries, including three members from Brazil and one from Mexico. This reflects the interest that Latin America has for a project which addresses the energy needs of the region. Presented here are some of the most recent developments in the IRIS project. The project's highest priority is the current pre-application licensing with the US NRC, which has required an investigation of the major accident sequences and a preliminary probabilistic risk assessment (PRA). The results of the accident analyses confirmed the outstanding inherent safety of the IRIS configuration and the PRA analyses indicated a core damage frequency due to internal events of the order of 2E-8. This not only highlights the enhanced safety characteristic of IRIS which should enhance its public acceptance, but it has also prompted IRIS to consider the possibility of being licensed without the need for off-site emergency response planning which would have a very positive economic implication. The modular IRIS, with each module rated at ∼ 335 MWe, is of course an ideal size for developing countries as it allows to easily introduce a moderate amount of power on limited electric grids. IRIS can be deployed in single modules in regions only requiring a few hundred MWs or in multiple modules deployed successively at time intervals in large urban areas requiring a larger amount of power increasing with time. IRIS is designed to operate ''hands-off'' as much as possible, with a small crew, having in mind deployment in areas with limited infrastructure. Thus IRIS has a 48-months maintenance interval, long refueling cycles in excess of three years, and is designed to increase as much as possible operational reliability. For example, the project has recently adopted internal control rod drive mechanisms to eliminate vessel head penetrations and the

  9. Discussion of gas trade model (GTM) results

    International Nuclear Information System (INIS)

    Manne, A.

    1989-01-01

    This is in response to your invitation to comment on the structure of GTM and also upon the differences between its results and those of other models participating in EMF9. First a word upon the structure. GTM was originally designed to provide both regional and sectoral detail within the North American market for natural gas at a single point in time, e.g. the year 2000. It is a spatial equilibrium model in which a solution is obtained by maximizing a nonlinear function, the sum of consumers and producers surplus. Since transport costs are included in producers cost, this formulation automatically ensures that geographical price differentials will not differ by more than transport costs. For purposes of EMF9, GTM was modified to allow for resource development and depletion over time

  10. Biometric iris image acquisition system with wavefront coding technology

    Science.gov (United States)

    Hsieh, Sheng-Hsun; Yang, Hsi-Wen; Huang, Shao-Hung; Li, Yung-Hui; Tien, Chung-Hao

    2013-09-01

    Biometric signatures for identity recognition have been practiced for centuries. Basically, the personal attributes used for a biometric identification system can be classified into two areas: one is based on physiological attributes, such as DNA, facial features, retinal vasculature, fingerprint, hand geometry, iris texture and so on; the other scenario is dependent on the individual behavioral attributes, such as signature, keystroke, voice and gait style. Among these features, iris recognition is one of the most attractive approaches due to its nature of randomness, texture stability over a life time, high entropy density and non-invasive acquisition. While the performance of iris recognition on high quality image is well investigated, not too many studies addressed that how iris recognition performs subject to non-ideal image data, especially when the data is acquired in challenging conditions, such as long working distance, dynamical movement of subjects, uncontrolled illumination conditions and so on. There are three main contributions in this paper. Firstly, the optical system parameters, such as magnification and field of view, was optimally designed through the first-order optics. Secondly, the irradiance constraints was derived by optical conservation theorem. Through the relationship between the subject and the detector, we could estimate the limitation of working distance when the camera lens and CCD sensor were known. The working distance is set to 3m in our system with pupil diameter 86mm and CCD irradiance 0.3mW/cm2. Finally, We employed a hybrid scheme combining eye tracking with pan and tilt system, wavefront coding technology, filter optimization and post signal recognition to implement a robust iris recognition system in dynamic operation. The blurred image was restored to ensure recognition accuracy over 3m working distance with 400mm focal length and aperture F/6.3 optics. The simulation result as well as experiment validates the proposed code

  11. A modified COMS plaque for iris melanoma

    Directory of Open Access Journals (Sweden)

    Daniel J. Scanderbeg

    2011-09-01

    Full Text Available Melanoma of the iris is a rare condition compared to posterior ocular tumors and in this case report we presenta 51-year-old female patient with diffuse iris melanoma. Traditional COMS (Collaborative Ocular Melanoma Studyplaques are used at our institution for radiation therapy, so a novel modification of the traditional plaque was requiredto allow better conformance with placement on the cornea. The usual silastic insert was machined to dimensions incompliance with the cornea, placed without incident, and treatment delivered with excellent patient tolerance of themodified plaque.

  12. IRIS Toxicological Review of Trichloroethylene (TCE) ...

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroethylene (TCE) that when finalized will appear on the Integrated Risk Information System (IRIS) database. The purpose of this Toxicological Review is to provide scientific support and rationale for the hazard and dose-response assessment in IRIS pertaining to chronic exposure to trichloroethylene. It is not intended to be a comprehensive treatise on the chemical or toxicological nature of trichloroethylene.

  13. Plateau iris secondary to iridociliary cysts.

    Science.gov (United States)

    Vila-Arteaga, J; Díaz-Céspedes, R A; Suriano, M M

    2015-11-01

    We present a case of plateau iris and glaucoma due to multiple unilateral iridociliary cysts. The patient was treated with iridotomy Nd: YAG laser and 360° iridoplasty, without achieving pressure control. Phacoemulsification improved the hypertension. Dynamic gonioscopy and OCT of the anterior chamber was also performed before and after treatment. Iridociliary cysts are a benign condition that can cause iris plateau configuration, and can produce a difficult to treat ocular hypertension. Cystotomy, peripheral iridoplasty, and other treatments have been proposed. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  14. IRIS: A global approach to nuclear power renaissance

    International Nuclear Information System (INIS)

    Carelli, M.D.

    2004-01-01

    Improved international reactor IRIS (International Reactor Innovative and Secure) is discussed. IRIS is defined as a modular reactor with integral arrangement and water coolant. Industrial companies, research, scientific groups and electric power producers of different countries (USA, Great Britain, Italy, Spain, Brazil, Russia, Mexico, Japan, Croatia) take part in the realization of IRIS. Basic parameters of the reactor, construction characteristics, arrangement are presented [ru

  15. IRIS: Supporting & Managing the Research Life-Cycle

    Science.gov (United States)

    Bollini, Andrea; Mennielli, Michele; Mornati, Susanna; Palmer, David T.

    2016-01-01

    IRIS is a new Current Research Information System (CRIS) developed by Cineca to upgrade and replace two previous solutions that have been used by Italian universities in the last 10 years. At the end of 2015, sixty-three Italian institutions are using IRIS. One of the main components of IRIS is DSpace-CRIS, an open source solution that can also be…

  16. Ethnicity distinctiveness through iris texture features using Gabor filters

    CSIR Research Space (South Africa)

    Mabuza-Hocquet, Gugulethu P

    2017-02-01

    Full Text Available Research in iris biometrics has been focused on utilizing iris features as a means of identity verification and authentication. However, not enough research work has been done to explore iris textures to determine soft biometrics such as gender...

  17. The Danish national passenger modelModel specification and results

    DEFF Research Database (Denmark)

    Rich, Jeppe; Hansen, Christian Overgaard

    2016-01-01

    The paper describes the structure of the new Danish National Passenger model and provides on this basis a general discussion of large-scale model design, cost-damping and model validation. The paper aims at providing three main contributions to the existing literature. Firstly, at the general level......, the paper provides a description of a large-scale forecast model with a discussion of the linkage between population synthesis, demand and assignment. Secondly, the paper gives specific attention to model specification and in particular choice of functional form and cost-damping. Specifically we suggest...... a family of logarithmic spline functions and illustrate how it is applied in the model. Thirdly and finally, we evaluate model sensitivity and performance by evaluating the distance distribution and elasticities. In the paper we present results where the spline-function is compared with more traditional...

  18. Superconducting solenoid model magnet test results

    Energy Technology Data Exchange (ETDEWEB)

    Carcagno, R.; Dimarco, J.; Feher, S.; Ginsburg, C.M.; Hess, C.; Kashikhin, V.V.; Orris, D.F.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab

    2006-08-01

    Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab High Intensity Neutrino Source (formerly known as Proton Driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab Magnet Test Facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests.

  19. Superconducting solenoid model magnet test results

    International Nuclear Information System (INIS)

    Carcagno, R.; Dimarco, J.; Feher, S.; Ginsburg, C.M.; Hess, C.; Kashikhin, V.V.; Orris, D.F.; Pischalnikov, Y.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; Tompkins, J.C.; Wokas, T.; Fermilab

    2006-01-01

    Superconducting solenoid magnets suitable for the room temperature front end of the Fermilab High Intensity Neutrino Source (formerly known as Proton Driver), an 8 GeV superconducting H- linac, have been designed and fabricated at Fermilab, and tested in the Fermilab Magnet Test Facility. We report here results of studies on the first model magnets in this program, including the mechanical properties during fabrication and testing in liquid helium at 4.2 K, quench performance, and magnetic field measurements. We also describe new test facility systems and instrumentation that have been developed to accomplish these tests

  20. Assessment of IRI-2016 profile parameters over Indian low latitude station

    Science.gov (United States)

    Patel, Nilesh C.; Karia, Sheetal P.; Pathak, Kamlesh N.

    2018-05-01

    The present study reports the assessment of the bottom-side profile thickness (B0), shape (B1) and F2-peak height (hmF2) parameters IRI-2016 model over the Indian region by using digisonde observations. The digisonde data from a low latitude station Ahmedabad, (located at the crest of the northern equatorial anomaly) during three months June-2012, July-2012 and December-2012 are considered for this study. Simultaneous comparison is made on the performance of three different options `Gul-1987', `Bil-2000' and the `ABT-2009' for the bottom-side profile, three different options`AMTB2013 (AMT)', `SHU-2015 (SHU)', and `BSE-1979 (BSE)' for the hmF2 estimation in the latest available IRI-2016 to that obtained from digisonde measurements. Further, the diurnal characteristics of the B0 and B1 from digisonde measurements are also compared with those from the IRI-2016 model using the three different options.

  1. Distribution and multiplication of iris severe mosaic potyvirus in bulbous Iris in relation to metabolic activity : implications for ISMV detection

    NARCIS (Netherlands)

    Vlugt, van der C.I.M.

    1994-01-01

    During cultivation of iris, several viruses may cause severe damage like yield reduction and discoloration of the plant. In commercial stocks in the Netherlands virtually all plants are infected with iris mild mosaic virus (IMMV) while iris severe mosaic virus (ISMV) and narcissus latent

  2. Dynamical seasonal climate prediction using an ocean-atmosphere coupled climate model developed in partnership between South Africa and the IRI

    CSIR Research Space (South Africa)

    Beraki, AF

    2014-02-01

    Full Text Available dedicated a large amount of resources to utilize Atmospheric General Circulation Models 66 (AGCMs) as operational seasonal forecast tools (Landman et al. 2012). These models 67 have all been developed outside of South Africa, but have been used extensively... Niña seasons (Landman et al. 2012; Landman and Beraki 2012). As noted above, coupled 99 models are largely assumed or hypothesized to represent the state of the art of seasonal 100 forecasting. In fact, it has been conclusively shown through...

  3. Scale Model Thruster Acoustic Measurement Results

    Science.gov (United States)

    Vargas, Magda; Kenny, R. Jeremy

    2013-01-01

    The Space Launch System (SLS) Scale Model Acoustic Test (SMAT) is a 5% scale representation of the SLS vehicle, mobile launcher, tower, and launch pad trench. The SLS launch propulsion system will be comprised of the Rocket Assisted Take-Off (RATO) motors representing the solid boosters and 4 Gas Hydrogen (GH2) thrusters representing the core engines. The GH2 thrusters were tested in a horizontal configuration in order to characterize their performance. In Phase 1, a single thruster was fired to determine the engine performance parameters necessary for scaling a single engine. A cluster configuration, consisting of the 4 thrusters, was tested in Phase 2 to integrate the system and determine their combined performance. Acoustic and overpressure data was collected during both test phases in order to characterize the system's acoustic performance. The results from the single thruster and 4- thuster system are discussed and compared.

  4. CMS standard model Higgs boson results

    Directory of Open Access Journals (Sweden)

    Garcia-Abia Pablo

    2013-11-01

    Full Text Available In July 2012 CMS announced the discovery of a new boson with properties resembling those of the long-sought Higgs boson. The analysis of the proton-proton collision data recorded by the CMS detector at the LHC, corresponding to integrated luminosities of 5.1 fb−1 at √s = 7 TeV and 19.6 fb−1 at √s = 8 TeV, confirm the Higgs-like nature of the new boson, with a signal strength associated with vector bosons and fermions consistent with the expectations for a standard model (SM Higgs boson, and spin-parity clearly favouring the scalar nature of the new boson. In this note I review the updated results of the CMS experiment.

  5. Modelling Extortion Racket Systems: Preliminary Results

    Science.gov (United States)

    Nardin, Luis G.; Andrighetto, Giulia; Székely, Áron; Conte, Rosaria

    Mafias are highly powerful and deeply entrenched organised criminal groups that cause both economic and social damage. Overcoming, or at least limiting, their harmful effects is a societally beneficial objective, which renders its dynamics understanding an objective of both scientific and political interests. We propose an agent-based simulation model aimed at understanding how independent and combined effects of legal and social norm-based processes help to counter mafias. Our results show that legal processes are effective in directly countering mafias by reducing their activities and changing the behaviour of the rest of population, yet they are not able to change people's mind-set that renders the change fragile. When combined with social norm-based processes, however, people's mind-set shifts towards a culture of legality rendering the observed behaviour resilient to change.

  6. New results in the Dual Parton Model

    International Nuclear Information System (INIS)

    Van, J.T.T.; Capella, A.

    1984-01-01

    In this paper, the similarity between the x distribution for particle production and the fragmentation functions are observed in e+e- collisions and in deep inelastic scattering are presented. Based on the observation, the authors develop a complete approach to multiparticle production which incorporates the most important features and concepts learned about high energy collisions. 1. Topological expansion : the dominant diagram at high energy corresponds to the simplest topology. 2. Unitarity : diagrams of various topology contribute to the cross sections in a way that unitary is preserved. 3. Regge behaviour and Duality. 4. Partonic structure of hadrons. These general theoretical ideas, result from many joint experimental and theoretical efforts on the study of soft hadron physics. The dual parton model is able to explain all the experimental features from FNAL to SPS collider energies. It has all the properties of an S-matrix theory and provides a unified description of hadron-hadron, hadron-nucleus and nucleus-nucleus collisions

  7. IRIS Bimonthly Public Meeting (Jun 2014)

    Science.gov (United States)

    On June 25-27, 2014, EPA hosted a public meeting/webinar, to provide an opportunity for the public to give input and participate in an open discussion regarding several IRIS chemical assessments of Hexavalent Chromium (Cr(VI)) and Inorganic Arsenic (iAs).

  8. IRIS Public Science Meeting (June 2016)

    Science.gov (United States)

    This June 2016 public meeting is made available to solicit comments on the public comment draft of the IRIS Assessment of tert-Butanol. The draft document was re-opened in the docket for a 60-day public comment period closing on July 16, 2016.

  9. Iris Murdoch, Liberal Education and Human Flourishing

    Science.gov (United States)

    Evans, William

    2009-01-01

    Articulating the good of liberal education--what we should teach and why we should teach it--is necessary to resist the subversion of liberal education to economic or political ends and the mania for measurable skills. I argue that Iris Murdoch's philosophical writings enrich the work of contemporary Aristotelians, such as Joseph Dunne and…

  10. Iris recognition using the JAVAVis Library

    Directory of Open Access Journals (Sweden)

    L.Martin García

    2008-12-01

    Full Text Available This project has been created to develop a biometric identification system through a man’s iris using a computer to perform the processing of the pictures. To develop this application, and to differentiate the project from others who have already implemented, we have used the image processing library JAVAVis and JAVA as a programming language.

  11. IRI profile parameters at equatorial latitudes

    International Nuclear Information System (INIS)

    Reinisch, B.W.; Huang Xueqin; Conway, J.

    2002-01-01

    The IRI bottom-side electron density profile is specified as a function of three parameters B0, B1, and D1 describing the F2 layer thickness and shape, and the shape of the F1 layer, respectively. Together with the URSI or CCIR coefficients for the F2 layer peak density and height, they completely specify the profiles as function of time, season and solar activity. In support of the international effort of determining the best set of parameters we have analyzed the diurnal variations of B0, B1, and D1 for Jicamarca for high solar activity during 1999 and 2000 for different seasons and magnetic activity. The B0 values vary from a minimum of ∼95 km at 0300 LT to ∼250 km at local noon (1700 UT). The diurnal variation is similar to the IRI2000 prediction. B1 varies from ∼1.9 at daytime to ∼2.2 at night. The value of D1 is ∼0.5. The parameters show little Kp dependence. Standard deviations are shown. We calculated the ionospheric total electron contents for March and April 1998 from the ionogram profiles at Jicamarca and compared them with IRI predictions using the IRI 2000 parameters. While there is fair agreement, a significant time shift of 1 to 2 hours occurs in the transition from night to daytime values. (author)

  12. IRIS Toxicological Review of Benzo[a]pyrene (Interagency ...

    Science.gov (United States)

    In January 2017, EPA finalized the IRIS assessment of Benzo[a]pyrene. The Toxicological Review was reviewed internally by EPA and by other federal agencies and White House Offices before public release. Consistent with the May 2009 IRIS assessment development process, all written comments on IRIS assessments submitted by other federal agencies and White House Offices are made publicly available. Accordingly, interagency comments and the interagency science discussion materials provided to other agencies, including interagency review drafts of the IRIS Toxicological Review of Benzo[a]pyrene are posted on this site. EPA is undertaking an update of the Integrated Risk Information System (IRIS) health assessment for benzo[a]pyrene (BaP). The outcome of this project is an updated Toxicological Review and IRIS Summary for BaP that will be entered into the IRIS database.

  13. Toward noncooperative iris recognition: a classification approach using multiple signatures.

    Science.gov (United States)

    Proença, Hugo; Alexandre, Luís A

    2007-04-01

    This paper focuses on noncooperative iris recognition, i.e., the capture of iris images at large distances, under less controlled lighting conditions, and without active participation of the subjects. This increases the probability of capturing very heterogeneous images (regarding focus, contrast, or brightness) and with several noise factors (iris obstructions and reflections). Current iris recognition systems are unable to deal with noisy data and substantially increase their error rates, especially the false rejections, in these conditions. We propose an iris classification method that divides the segmented and normalized iris image into six regions, makes an independent feature extraction and comparison for each region, and combines each of the dissimilarity values through a classification rule. Experiments show a substantial decrease, higher than 40 percent, of the false rejection rates in the recognition of noisy iris images.

  14. Finiteness results for Abelian tree models

    NARCIS (Netherlands)

    Draisma, J.; Eggermont, R.H.

    2015-01-01

    Equivariant tree models are statistical models used in the reconstruction of phylogenetic trees from genetic data. Here equivariant refers to a symmetry group imposed on the root distribution and on the transition matrices in the model. We prove that if that symmetry group is Abelian, then the

  15. Finiteness results for Abelian tree models

    NARCIS (Netherlands)

    Draisma, J.; Eggermont, R.H.

    2012-01-01

    Equivariant tree models are statistical models used in the reconstruction of phylogenetic trees from genetic data. Here equivariant refers to a symmetry group imposed on the root distribution and on the transition matrices in the model. We prove that if that symmetry group is Abelian, then the

  16. Finiteness results for Abelian tree models

    NARCIS (Netherlands)

    Draisma, J.; Eggermont, R.H.

    2015-01-01

    Equivariant tree models are statistical models used in the reconstruction of phylogenetic trees from genetic data. Here equivariant§ refers to a symmetry group imposed on the root distribution and on the transition matrices in the model. We prove that if that symmetry group is Abelian, then the

  17. Lack of Radiation Maculopathy After Palladium-103 Plaque Radiotherapy for Iris Melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Yousef, Yacoub A. [New York Eye Cancer Center, New York Eye and Ear Infirmary, and New York University School of Medicine, New York, NY (United States); Finger, Paul T., E-mail: pfinger@eyecancer.com [New York Eye Cancer Center, New York Eye and Ear Infirmary, and New York University School of Medicine, New York, NY (United States)

    2012-07-15

    Purpose: To report on the risk of radiation maculopathy for iris and iridociliary melanomas treated by {sup 103}Pd plaque radiotherapy. Methods and Materials: This is a retrospective clinical case series of 30 eyes in 30 patients with melanomas limited to the iris or invading the ciliary body. The main outcome measures included demographic information, laterality, tumor size, location, visual acuity, radiation dose, local control, retinal evaluation, and duration of follow-up. Results: Thirty patients were followed for a median 36 months (range, 12-90 months). Sixteen of 30 tumors (53%) were pure iris melanomas, and 14 (47%) were primary iris melanomas extending into the ciliary body. Radiation dosimetry showed that the median tumor apex dose was 85 Gy (range, 75-100 Gy), lens dose 43.5 Gy (range, 17.8-60 Gy), fovea dose 1.8 Gy (range, 1.3-5 Gy), and central optic disc dose 1.7 Gy (range, 1.3-4.7 Gy). Cataracts developed in 20 of the 28 phakic eyes (71.4%). No patient in this series developed radiation maculopathy or radiation optic neuropathy. Last best-corrected visual acuity was {>=}20/25 in 28 patients (93%) at a median 36 months' follow-up. Conclusion: Though visual acuities were transiently affected by radiation cataract, no radiation maculopathy or optic neuropathy has been noted after {sup 103}Pd treatment of iris and iridociliary melanomas.

  18. Lack of Radiation Maculopathy After Palladium-103 Plaque Radiotherapy for Iris Melanoma

    International Nuclear Information System (INIS)

    Yousef, Yacoub A.; Finger, Paul T.

    2012-01-01

    Purpose: To report on the risk of radiation maculopathy for iris and iridociliary melanomas treated by 103 Pd plaque radiotherapy. Methods and Materials: This is a retrospective clinical case series of 30 eyes in 30 patients with melanomas limited to the iris or invading the ciliary body. The main outcome measures included demographic information, laterality, tumor size, location, visual acuity, radiation dose, local control, retinal evaluation, and duration of follow-up. Results: Thirty patients were followed for a median 36 months (range, 12–90 months). Sixteen of 30 tumors (53%) were pure iris melanomas, and 14 (47%) were primary iris melanomas extending into the ciliary body. Radiation dosimetry showed that the median tumor apex dose was 85 Gy (range, 75–100 Gy), lens dose 43.5 Gy (range, 17.8–60 Gy), fovea dose 1.8 Gy (range, 1.3–5 Gy), and central optic disc dose 1.7 Gy (range, 1.3–4.7 Gy). Cataracts developed in 20 of the 28 phakic eyes (71.4%). No patient in this series developed radiation maculopathy or radiation optic neuropathy. Last best-corrected visual acuity was ≥20/25 in 28 patients (93%) at a median 36 months’ follow-up. Conclusion: Though visual acuities were transiently affected by radiation cataract, no radiation maculopathy or optic neuropathy has been noted after 103 Pd treatment of iris and iridociliary melanomas.

  19. Evolution of iris colour in relation to cavity nesting and parental care in passerine birds.

    Science.gov (United States)

    Davidson, Gabrielle L; Thornton, Alex; Clayton, Nicola S

    2017-01-01

    Strong selection pressures are known to act on animal coloration. Although many animals vary in eye colour, virtually no research has investigated the functional significance of these colour traits. Passeriformes have a range of iris colours, making them an ideal system to investigate how and why iris colour has evolved. Using phylogenetic comparative methods, we tested the hypothesis that conspicuous iris colour in passerine birds evolved in response to (a) coordination of offspring care and (b) cavity nesting, two traits thought to be involved in intra-specific gaze sensitivity. We found that iris colour and cooperative offspring care by two or more individuals evolved independently, suggesting that bright eyes are not important for coordinating parental care through eye gaze. Furthermore, we found that evolution between iris colour and nesting behaviour did occur in a dependent manner, but contrary to predictions, transitions to coloured eyes were not more frequent in cavity nesters than non-cavity nesters. Instead, our results indicate that selection away from having bright eyes was much stronger in non-cavity nesters than cavity nesters, perhaps because conspicuous eye coloration in species not concealed within a cavity would be more visible to predators. © 2017 The Authors.

  20. Clinical observation of Artisan iris-clip intraocular lens implantation at stage Ⅰ

    Directory of Open Access Journals (Sweden)

    Qing Zhou

    2014-09-01

    Full Text Available AIM: To observe the clinical efficacy of Artisan iris-clip intraocular lens(IOLimplantation on cataract with a wide range of lens dislocation.METHODS: Twenty-four hospital patients(28 eyesof cataract with lens subluxation by trauma(20 patients, 20 eyesand Marfan's syndrome(4 patients, 8 eyesduring May 2007 to December 2011 were selected. All of them underwent phacoemulsification or an anterior vitrectomy and Artisan iris-clip IOL implantation at stage Ⅰ. Postoperative visual acuity, corneal endothelial cell count, intraocular lens position and postoperative complications were observed. Follow-up time was 6mo.RESULTS:Compared with the preoperative, postoperative best corrected visual acuity improved to varying degrees, visual acuity of 0.1-0.5 was in 20 eyes, 0.5-1.0 in 8 eyes. After followed up 1-6mo, no artificial lens shift, iris inflammation, iris atrophy and corneal decompensation and other complications were observed.CONCLUSION: Cataract surgery with a wide range of lens dislocation is difficult, but as long as surgeons who have a wealth of clinical experience and superb skills, still can carry out phacoemulsification surgery or anterior vitrectomy and Artisan iris-clip IOL implantation and obtain a better outcome.

  1. Effect of cataract surgery and pupil dilation on iris pattern recognition for personal authentication.

    Science.gov (United States)

    Dhir, L; Habib, N E; Monro, D M; Rakshit, S

    2010-06-01

    The purpose of this study was to investigate the effect of cataract surgery and pupil dilation on iris pattern recognition for personal authentication. Prospective non-comparative cohort study. Images of 15 subjects were captured before (enrolment), and 5, 10, and 15 min after instillation of mydriatics before routine cataract surgery. After cataract surgery, images were captured 2 weeks thereafter. Enrolled and test images (after pupillary dilation and after cataract surgery) were segmented to extract the iris. This was then unwrapped onto a rectangular format for normalization and a novel method using the Discrete Cosine Transform was applied to encode the image into binary bits. The numerical difference between two iris codes (Hamming distance, HD) was calculated. The HD between identification and enrolment codes was used as a score and was compared with a confidence threshold for specific equipment, giving a match or non-match result. The Correct Recognition Rate (CRR) and Equal Error Rates (EERs) were calculated to analyse overall system performance. After cataract surgery, perfect identification and verification was achieved, with zero false acceptance rate, zero false rejection rate, and zero EER. After pupillary dilation, non-elastic deformation occurs and a CRR of 86.67% and EER of 9.33% were obtained. Conventional circle-based localization methods are inadequate. Matching reliability decreases considerably with increase in pupillary dilation. Cataract surgery has no effect on iris pattern recognition, whereas pupil dilation may be used to defeat an iris-based authentication system.

  2. A field study of the accuracy and reliability of a biometric iris recognition system.

    Science.gov (United States)

    Latman, Neal S; Herb, Emily

    2013-06-01

    The iris of the eye appears to satisfy the criteria for a good anatomical characteristic for use in a biometric system. The purpose of this study was to evaluate a biometric iris recognition system: Mobile-Eyes™. The enrollment, verification, and identification applications were evaluated in a field study for accuracy and reliability using both irises of 277 subjects. Independent variables included a wide range of subject demographics, ambient light, and ambient temperature. A sub-set of 35 subjects had alcohol-induced nystagmus. There were 2710 identification and verification attempts, which resulted in 1,501,340 and 5540 iris comparisons respectively. In this study, the system successfully enrolled all subjects on the first attempt. All 277 subjects were successfully verified and identified on the first day of enrollment. None of the current or prior eye conditions prevented enrollment, verification, or identification. All 35 subjects with alcohol-induced nystagmus were successfully verified and identified. There were no false verifications or false identifications. Two conditions were identified that potentially could circumvent the use of iris recognitions systems in general. The Mobile-Eyes™ iris recognition system exhibited accurate and reliable enrollment, verification, and identification applications in this study. It may have special applications in subjects with nystagmus. Copyright © 2012 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Reliability of automatic biometric iris recognition after phacoemulsification or drug-induced pupil dilation.

    Science.gov (United States)

    Seyeddain, Orang; Kraker, Hannes; Redlberger, Andreas; Dexl, Alois K; Grabner, Günther; Emesz, Martin

    2014-01-01

    To investigate the reliability of a biometric iris recognition system for personal authentication after cataract surgery or iatrogenic pupil dilation. This was a prospective, nonrandomized, single-center, cohort study for evaluating the performance of an iris recognition system 2-24 hours after phacoemulsification and intraocular lens implantation (group 1) and before and after iatrogenic pupil dilation (group 2). Of the 173 eyes that could be enrolled before cataract surgery, 164 (94.8%) were easily recognized postoperatively, whereas in 9 (5.2%) this was not possible. However, these 9 eyes could be reenrolled and afterwards recognized successfully. In group 2, of a total of 184 eyes that were enrolled in miosis, a total of 22 (11.9%) could not be recognized in mydriasis and therefore needed reenrollment. No single case of false-positive acceptance occurred in either group. The results of this trial indicate that standard cataract surgery seems not to be a limiting factor for iris recognition in the large majority of cases. Some patients (5.2% in this study) might need "reenrollment" after cataract surgery. Iris recognition was primarily successful in eyes with medically dilated pupils in nearly 9 out of 10 eyes. No single case of false-positive acceptance occurred in either group in this trial. It seems therefore that iris recognition is a valid biometric method in the majority of cases after cataract surgery or after pupil dilation.

  4. Genetic and phenotypic variability of iris color in Buenos Aires population

    Directory of Open Access Journals (Sweden)

    Diana María Hohl

    Full Text Available Abstract The aim of this work was to describe the phenotypic and genotypic variability related to iris color for the population of Buenos Aires province (Argentina, and to assess the usefulness of current methods of analysis for this country. We studied five Single Nucleotide Polymorphisms (SNPs included in the IrisPlex kit, in 118 individuals, and we quantified eye color with Digital Iris Analysis Tool. The markers fit Hardy-Weinberg equilibrium for the whole sample, but not for rs12913832 within the group of brown eyes (LR=8.429; p=0.004. We found a remarkable association of HERC2 rs12913832 GG with blue color (p < 0.01 but the other markers did not show any association with iris color. The results for the Buenos Aires population differ from those of other populations of the world for these polymorphisms (p < 0,01. The differences we found might respond to the admixed ethnic composition of Argentina; therefore, methods of analysis used in European populations should be carefully applied when studying the population of Argentina. These findings reaffirm the importance of this investigation in the Argentinian population for people identification based on iris color.

  5. Relationship between iris constitution analysis and TNF-alpha gene polymorphism in hypertensives.

    Science.gov (United States)

    Yoo, Chun-Sang; Hwang, Woo-Jun; Hong, Seung-Heon; Lee, Hye-Jung; Jeong, Hyun-Ja; Kim, Su-Jin; Kim, Hyung-Min; Um, Jae-Young

    2007-01-01

    Iridology is a complementary and alternative medicine that involves the diagnosis of medical conditions by noting irregularities of the pigmentation in the iris. Iris constitution has a strong hereditary component. Tumor necrosis factor-alpha (TNFalpha), a pleiotropic cytokine, has been implicated in many pathological processes including hypertension. In this paper, the relationship between iris constitution and TNFalpha gene polymorphism in those with hypertension is investigated. Eighty seven hypertensive individuals and 79 controls were classified according to iris constitution and the TNFalpha genotype of each individual determined. Compared to the controls, the frequency of the TNFalpha GA heterozygote was lower in the hypertensive group, although the statistical significance was marginal (p = 0.08). This result implies an association with resistance to the disease. In addition, the frequency of the cardio-renal connective tissue weakness type was significantly higher in the hypertensive group with the TNFalpha GG genotype, as compared to the controls (p = 0.001). An association is demonstrated among TNFalpha gene polymorphism, Koreans with hypertension, and iris constitution.

  6. Immersive visualization of dynamic CFD model results

    International Nuclear Information System (INIS)

    Comparato, J.R.; Ringel, K.L.; Heath, D.J.

    2004-01-01

    With immersive visualization the engineer has the means for vividly understanding problem causes and discovering opportunities to improve design. Software can generate an interactive world in which collaborators experience the results of complex mathematical simulations such as computational fluid dynamic (CFD) modeling. Such software, while providing unique benefits over traditional visualization techniques, presents special development challenges. The visualization of large quantities of data interactively requires both significant computational power and shrewd data management. On the computational front, commodity hardware is outperforming large workstations in graphical quality and frame rates. Also, 64-bit commodity computing shows promise in enabling interactive visualization of large datasets. Initial interactive transient visualization methods and examples are presented, as well as development trends in commodity hardware and clustering. Interactive, immersive visualization relies on relevant data being stored in active memory for fast response to user requests. For large or transient datasets, data management becomes a key issue. Techniques for dynamic data loading and data reduction are presented as means to increase visualization performance. (author)

  7. Linkage of PRA models. Phase 1, Results

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.L.; Knudsen, J.K.; Kelly, D.L.

    1995-12-01

    The goal of the Phase I work of the ``Linkage of PRA Models`` project was to postulate methods of providing guidance for US Nuclear Regulator Commission (NRC) personnel on the selection and usage of probabilistic risk assessment (PRA) models that are best suited to the analysis they are performing. In particular, methods and associated features are provided for (a) the selection of an appropriate PRA model for a particular analysis, (b) complementary evaluation tools for the analysis, and (c) a PRA model cross-referencing method. As part of this work, three areas adjoining ``linking`` analyses to PRA models were investigated: (a) the PRA models that are currently available, (b) the various types of analyses that are performed within the NRC, and (c) the difficulty in trying to provide a ``generic`` classification scheme to groups plants based upon a particular plant attribute.

  8. Linkage of PRA models. Phase 1, Results

    International Nuclear Information System (INIS)

    Smith, C.L.; Knudsen, J.K.; Kelly, D.L.

    1995-12-01

    The goal of the Phase I work of the ''Linkage of PRA Models'' project was to postulate methods of providing guidance for US Nuclear Regulator Commission (NRC) personnel on the selection and usage of probabilistic risk assessment (PRA) models that are best suited to the analysis they are performing. In particular, methods and associated features are provided for (a) the selection of an appropriate PRA model for a particular analysis, (b) complementary evaluation tools for the analysis, and (c) a PRA model cross-referencing method. As part of this work, three areas adjoining ''linking'' analyses to PRA models were investigated: (a) the PRA models that are currently available, (b) the various types of analyses that are performed within the NRC, and (c) the difficulty in trying to provide a ''generic'' classification scheme to groups plants based upon a particular plant attribute

  9. Engineering Glass Passivation Layers -Model Results

    Energy Technology Data Exchange (ETDEWEB)

    Skorski, Daniel C.; Ryan, Joseph V.; Strachan, Denis M.; Lepry, William C.

    2011-08-08

    The immobilization of radioactive waste into glass waste forms is a baseline process of nuclear waste management not only in the United States, but worldwide. The rate of radionuclide release from these glasses is a critical measure of the quality of the waste form. Over long-term tests and using extrapolations of ancient analogues, it has been shown that well designed glasses exhibit a dissolution rate that quickly decreases to a slow residual rate for the lifetime of the glass. The mechanistic cause of this decreased corrosion rate is a subject of debate, with one of the major theories suggesting that the decrease is caused by the formation of corrosion products in such a manner as to present a diffusion barrier on the surface of the glass. Although there is much evidence of this type of mechanism, there has been no attempt to engineer the effect to maximize the passivating qualities of the corrosion products. This study represents the first attempt to engineer the creation of passivating phases on the surface of glasses. Our approach utilizes interactions between the dissolving glass and elements from the disposal environment to create impermeable capping layers. By drawing from other corrosion studies in areas where passivation layers have been successfully engineered to protect the bulk material, we present here a report on mineral phases that are likely have a morphological tendency to encrust the surface of the glass. Our modeling has focused on using the AFCI glass system in a carbonate, sulfate, and phosphate rich environment. We evaluate the minerals predicted to form to determine the likelihood of the formation of a protective layer on the surface of the glass. We have also modeled individual ions in solutions vs. pH and the addition of aluminum and silicon. These results allow us to understand the pH and ion concentration dependence of mineral formation. We have determined that iron minerals are likely to form a complete incrustation layer and we plan

  10. CIEMAT model results for Esthwaite Water

    International Nuclear Information System (INIS)

    Aguero, A.; Garcia-Olivares, A.

    2000-01-01

    This study used the transfer model PRYMA-LO, developed by CIEMAT-IMA, Madrid, Spain, to simulate the transfer of Cs-137 in watershed scenarios. The main processes considered by the model include: transfer of the fallout to the ground, incorporation of the fallout radioisotopes into the water flow, and their removal from the system. The model was tested against observation data obtained in water and sediments of Esthwaite Water, Lake District, UK. This comparison made it possible to calibrate the parameters of the model to the specific scenario

  11. Revision of IRIS/IDA Seismic Station Metadata

    Science.gov (United States)

    Xu, W.; Davis, P.; Auerbach, D.; Klimczak, E.

    2017-12-01

    Trustworthy data quality assurance has always been one of the goals of seismic network operators and data management centers. This task is considerably complex and evolving due to the huge quantities as well as the rapidly changing characteristics and complexities of seismic data. Published metadata usually reflect instrument response characteristics and their accuracies, which includes zero frequency sensitivity for both seismometer and data logger as well as other, frequency-dependent elements. In this work, we are mainly focused studying the variation of the seismometer sensitivity with time of IRIS/IDA seismic recording systems with a goal to improve the metadata accuracy for the history of the network. There are several ways to measure the accuracy of seismometer sensitivity for the seismic stations in service. An effective practice recently developed is to collocate a reference seismometer in proximity to verify the in-situ sensors' calibration. For those stations with a secondary broadband seismometer, IRIS' MUSTANG metric computation system introduced a transfer function metric to reflect two sensors' gain ratios in the microseism frequency band. In addition, a simulation approach based on M2 tidal measurements has been proposed and proven to be effective. In this work, we compare and analyze the results from three different methods, and concluded that the collocated-sensor method is most stable and reliable with the minimum uncertainties all the time. However, for epochs without both the collocated sensor and secondary seismometer, we rely on the analysis results from tide method. For the data since 1992 on IDA stations, we computed over 600 revised seismometer sensitivities for all the IRIS/IDA network calibration epochs. Hopefully further revision procedures will help to guarantee that the data is accurately reflected by the metadata of these stations.

  12. Training and assessment of psychomotor skills for performing laparoscopic surgery using BEST-IRIS virtual reality training simulator.

    Science.gov (United States)

    Makam, Ramesh; Rajan, C S; Brendon, Tulip; Shreedhar, V; Saleem, K; Shrivastava, Sangeeta; Sudarshan, R; Naidu, Prakash

    2004-01-01

    In this article, we present the results of a pilot study that examined the performance of people training on a Virtual Reality based BEST-IRIS Laparoscopic Surgery Training Simulator. The performance of experienced surgeons was examined and compared to the performance of residents. The purpose of this study is to validate the BEST-IRIS training simulator. It appeared to be a useful training and assessment tool.

  13. Evaluating empathy in Colombian ex-combatants: Examination of the internal structure of the Interpersonal Reactivity Index (IRI) in Spanish.

    Science.gov (United States)

    Garcia-Barrera, Mauricio A; Karr, Justin E; Trujillo-Orrego, Natalia; Trujillo-Orrego, Sandra; Pineda, David A

    2017-01-01

    The Republic of Colombia has a long-standing history of internal armed conflict, further complicated by the ideological assumptions underlying their war. In recent years, its government designed the Program for Reincorporation to Civilian Life (Programa para la Reincorporación a la Vida Civil, PRVC), aiming demobilization of thousands of insurgents who were involved in guerilla and paramilitary forces. One PRVC goal involves the psychological characterization of its reincorporated members, aiming the informed design of effective and efficacious interventions to improve their adjustment. We are interested in the examination of empathy in this population. Empathy refers to the ability to predict, understand, and experience other's feelings. Empathy appears to have an effect on level of aggressive behavior. The Interpersonal Reactivity Index (IRI; Davis, 1980, 1983) is a well-established 28-item self-report tool for the assessment of empathy, including 4 scales: Perspective Taking, Fantasy, Empathic Concern, and Personal Distress. Versions in Spanish were validated in Spain and Chile, but no norms for Colombians exist. We examined the factorial structure of the IRI in a sample of 548 (83.4% males) members of the PRVC. Ten items with low factor loadings were eliminated following a series of confirmatory factor analyses (CFA). The final 4-factor model (Model 2) reached an acceptable fit (e.g., CFI = .898). A second-order CFA demonstrated that empathic concern correlated too high with a common "empathy" latent factor. With these results at hand, our 18-item IRI version in Spanish achieved a factorial structure comparable to that previously validated for Spanish speakers from other countries. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. Application of the nudged elastic band method to the point-to-point radio wave ray tracing in IRI modeled ionosphere

    Science.gov (United States)

    Nosikov, I. A.; Klimenko, M. V.; Bessarab, P. F.; Zhbankov, G. A.

    2017-07-01

    Point-to-point ray tracing is an important problem in many fields of science. While direct variational methods where some trajectory is transformed to an optimal one are routinely used in calculations of pathways of seismic waves, chemical reactions, diffusion processes, etc., this approach is not widely known in ionospheric point-to-point ray tracing. We apply the Nudged Elastic Band (NEB) method to a radio wave propagation problem. In the NEB method, a chain of points which gives a discrete representation of the radio wave ray is adjusted iteratively to an optimal configuration satisfying the Fermat's principle, while the endpoints of the trajectory are kept fixed according to the boundary conditions. Transverse displacements define the radio ray trajectory, while springs between the points control their distribution along the ray. The method is applied to a study of point-to-point ionospheric ray tracing, where the propagation medium is obtained with the International Reference Ionosphere model taking into account traveling ionospheric disturbances. A 2-dimensional representation of the optical path functional is developed and used to gain insight into the fundamental difference between high and low rays. We conclude that high and low rays are minima and saddle points of the optical path functional, respectively.

  15. IRIS design overview and status update

    International Nuclear Information System (INIS)

    Carelli, M.D.; Petrovic, B.; Conway, L.E.; Oriani, L.; Kling, C.L.; Miller, K.; Lombardi, C.V.; Ricotti, M.E.; Barroso, A.C.O.; Collado, J.M.; Cinotti, L.; Storai, S.; Berra, F.; Todreas, N.E.; Ninokata, H.; Cavlina, N.; Grgic, D.; Oriolo, F.; Moraes, M.M.; Frederico, C.; Henning, F.; Griffith, W.; Love, J.; Ingersoll, D.T.; Wood, R.; Alonso, G.; Kodochigov, N.; Polunichev, V.; Augutis, J.; Alzbutas, R.; Boroughs, R.D.; Naviglio, A.; Panella, B.

    2005-01-01

    The International Reactor Innovative and Secure (IRIS) is an advanced, integral, light-water cooled reactor of medium generating capacity (1000 MWt, or ∼335 MWe), geared at near term deployment (2012- 2015). It has been under development since the turn of the century by an international consortium--led by Westinghouse--that includes 21 organizations from 10 countries, and it is currently in the pre-application licensing process with the U.S. Nuclear Regulatory Commission (NRC). This paper describes its integral design (i.e., steam generators, pumps, pressurizer and control rod drive mechanisms are all included inside the reactor vessel, together with the core, control rods, and neutron reflector/shield) and discusses the unique ('safety-by-design') TM IRIS philosophy. This approach, by eliminating accidents at the design stage, or decreasing their consequences and probabilities when outright elimination is not possible, provides a very powerful first level of defense in depth. The ('safety by- design') TM allows a significant reduction and simplification of the passive safety systems, which not only improves safety but simultaneously reduces the overall cost. Moreover, it supports licensing the power plant without the need for off-site emergency response planning--an objective which is part of the pre-application with NRC and is also pursued within an international research project coordinated by the International Atomic Energy Agency (IAEA). This would allow IRIS to be treated as any other industrial facility, located closer to population centers, and enable its effective dual-purpose use for electricity production and co-generation (district heating, desalination, industrial steam). The modular IRIS--with each module rated at ∼335 MWe--is an ideal size for developing countries as it allows to easily introducing single modules in regions only requiring a few hundred MWs, or a moderate amount of power on limited electric grids. IRIS can be also deployed in

  16. Post irradiation examinations on UMo full-sized plates - IRIS2 experiment

    International Nuclear Information System (INIS)

    Huet, F.; Noirot, J.; Marelle, V.; Dubois, S.; Boulcourt, P.; Sacristan, P.; Naury, S.; Lemoine, P.

    2005-01-01

    IRIS2 irradiation was the last irradiation of 4 full sized plates launched by CEA for the French UMo group to test in which operating conditions the coarse porosity forms in the UMo/Al interaction product. IRIS2 consists in four plates with high uranium loading and U-7wt%Mo atomised powder irradiated up to 60 days at OSIRIS reactor in IRIS device at a peak power of 238 W.cm -2 . The results show that in the tested conditions pillowing of the plate started from a fission density over 2.10 21 fission.cm -3 . Moreover, they show that the fission products and impurities have a key-role in the origin of the excessive plate swelling. (author)

  17. Flying Training Capacity Model: Initial Results

    National Research Council Canada - National Science Library

    Lynch, Susan

    2005-01-01

    OBJECTIVE: (1) Determine the flying training capacity for 6 bases: * Sheppard AFB * Randolph AFB * Moody AFB * Columbus AFB * Laughlin AFB * Vance AFB * (2) Develop versatile flying training capacity simulation model for AETC...

  18. IRIS COLOUR CLASSIFICATION SCALES--THEN AND NOW.

    Science.gov (United States)

    Grigore, Mariana; Avram, Alina

    2015-01-01

    Eye colour is one of the most obvious phenotypic traits of an individual. Since the first documented classification scale developed in 1843, there have been numerous attempts to classify the iris colour. In the past centuries, iris colour classification scales has had various colour categories and mostly relied on comparison of an individual's eye with painted glass eyes. Once photography techniques were refined, standard iris photographs replaced painted eyes, but this did not solve the problem of painted/ printed colour variability in time. Early clinical scales were easy to use, but lacked objectivity and were not standardised or statistically tested for reproducibility. The era of automated iris colour classification systems came with the technological development. Spectrophotometry, digital analysis of high-resolution iris images, hyper spectral analysis of the human real iris and the dedicated iris colour analysis software, all accomplished an objective, accurate iris colour classification, but are quite expensive and limited in use to research environment. Iris colour classification systems evolved continuously due to their use in a wide range of studies, especially in the fields of anthropology, epidemiology and genetics. Despite the wide range of the existing scales, up until present there has been no generally accepted iris colour classification scale.

  19. IRIS COLOUR CLASSIFICATION SCALES – THEN AND NOW

    Science.gov (United States)

    Grigore, Mariana; Avram, Alina

    2015-01-01

    Eye colour is one of the most obvious phenotypic traits of an individual. Since the first documented classification scale developed in 1843, there have been numerous attempts to classify the iris colour. In the past centuries, iris colour classification scales has had various colour categories and mostly relied on comparison of an individual’s eye with painted glass eyes. Once photography techniques were refined, standard iris photographs replaced painted eyes, but this did not solve the problem of painted/ printed colour variability in time. Early clinical scales were easy to use, but lacked objectivity and were not standardised or statistically tested for reproducibility. The era of automated iris colour classification systems came with the technological development. Spectrophotometry, digital analysis of high-resolution iris images, hyper spectral analysis of the human real iris and the dedicated iris colour analysis software, all accomplished an objective, accurate iris colour classification, but are quite expensive and limited in use to research environment. Iris colour classification systems evolved continuously due to their use in a wide range of studies, especially in the fields of anthropology, epidemiology and genetics. Despite the wide range of the existing scales, up until present there has been no generally accepted iris colour classification scale. PMID:27373112

  20. Iris colour in relation to myopia among Chinese school-aged children.

    Science.gov (United States)

    Pan, Chen-Wei; Qiu, Qin-Xiao; Qian, Deng-Juan; Hu, Dan-Ning; Li, Jun; Saw, Seang-Mei; Zhong, Hua

    2018-01-01

    Understanding the association of iris colour and myopia may provide further insights into the role of the wavelength of lights in the pathophysiology of myopia. We aim to assess the association of iris colour and myopia in a school-based sample of Chinese students. Two thousand three hundred and forty-six Year 7 students from 10 middle schools (93.5% response rate) aged 13-14 years in Mojiang, a small county located in Southwestern China, participated in the study. We obtained standardised slit lamp photographs and developed a grading system assessing iris colour (higher grade denoting a darker iris). Refractive error was measured after cycloplegia using an autorefractor by optometrists or trained technicians. An IOLMaster (www.zeiss.com) was used to measure ocular biometric parameters including axial length (AL). Of all the study participants, 693 (29.5%) were affected by myopia with the prevalence estimates being higher in girls (36.8%; 95% confidence interval [CI]: 34.0, 39.6) than in boys (22.8%; 95% CI: 20.4, 25.1) (p iris colour tended to have a higher prevalence of myopia, a more myopic refraction and a longer AL. Dose-response relationships were observed in all regression models (p for trend iris colour was associated with more myopic refractive errors and longer ALs among Chinese school-aged children and this association was independent of other known myopia-related risk factors. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

  1. Systematic Re-evaluation of Iris atrofusca Baker (Sawsan Jela'd) of Shafa Badran in Jordan as Iris nigricans Dinsmore

    International Nuclear Information System (INIS)

    Oran, S.; AL-Da'ja, I.

    2003-01-01

    The identity of one species of Iris (Iridaceae) from Locality at Shafa Badran area in Amman/Jordan has been reassessed and reidentified as I.nigricans Dinsmore, the national flower of Jordan, as it is misidentified as I. atrofusca for plants collected and identified from this area previously and as recorded in the related literature ( Post, 1932; Feinbrun, 1986). This decision has been made on the basis of studying fresh plants collected from Shafa Badran area, northeast of Amman in the period March-April 2001. The confirmation of identity of the species of Iris occur in Shafa Badran was based on studying the morphological characteristics of the leaves ,stems flowers for plants collected from that area, as well as studying the pollen grains and seed characteristics using light and scanning electron microscopy, as compared with plants of Iris nigricans collected from Madaba area for the same characters. Moreover, herbarium specimens deposited st Amman herbarium were checked and reidentified as I. nigricans. The results of studying the vegetative reproductive characters suggesting that the species that is occurring in Shafa Badran area is I.nigricans. However, these findings suggest that an interbreeding might have taken place between the individuals of I. nigricans in Shafa Badran and I.atrofusca from a neighboring geographical area called Jarash in North of Jordan, close enough that they are not geographically isolated for specimens that were probably intermixed with the population of Iris nigricans in Shafa Badran area. ( authors)

  2. Ten years of intraoperative floppy iris syndrome in the era of α-blockers

    Science.gov (United States)

    Mohamad Al-Ali, Badereddin; Radmayr, Christian; Weber, Maria; Horninger, Wolfgang; Findl, Oliver; Plas, Eugen

    2017-01-01

    Introduction The use of alpha-1 receptor antagonists in the treatment of benign prostatic hyperplasia (BPH) has created a problem in ophthalmic surgery, the so-called intraoperative floppy iris syndrome (IFIS). This consists of a billowing iris, insufficient pupillary dilation with progressive intraoperative miosis, and protrusion of iris tissue through the tunnel and side port incision that are made for access to the anterior chamber during surgery. IFIS presents particular difficulties in cataract surgery which is carried out through the pupil with manipulations in the immediate vicinity of the iris. The complications range from poor visibility of the operative field to iris damage with the surgical instruments and to rupture of the posterior capsule, with loss of lens material into the vitreous body. Material and methods A comprehensive literature review was performed using MEDLINE with MeSH terms and keywords ‘benign prostatic hyperplasia’, ‘intraoperative floppy iris syndrome’, ‘adrenergic alpha-antagonist’ and ‘cataract surgery’. In addition, reference lists from identified publications were reviewed to identify reports and studies of interest from 2001 to 2017. Results The A total of 95% of experienced ophthalmologic surgeons reported that systematic treatment with tamsulosin represents a challenging surgical condition increasing the risk of complications. Alpha-blockers are commonly prescribed, with 1,079,505 packages of tamsulosin prescribed each month in 2014 in Austria. Dose modification may be one way to reduce the risk of IFIS. A lower incidence of IFIS was reported in patients on tamsulosin in Japan, but the recommended dosage was lower than that used in Europe and the US (0.2 mg vs. 0.4 mg). Conclusions We showed that not all patients taking tamsulosin experience IFIS. Moreover, larger investigations with a prospective design are needed, including studies to monitor the pre- and post-therapeutic ophthalmologic changes under tamsulosin

  3. Calculation of Single Cell and Fuel Assembly IRIS Benchmarks Using WIMSD5B and GNOMER Codes

    International Nuclear Information System (INIS)

    Pevec, D.; Grgic, D.; Jecmenica, R.

    2002-01-01

    IRIS reactor (an acronym for International Reactor Innovative and Secure) is a modular, integral, light water cooled, small to medium power (100-335 MWe/module) reactor, which addresses the requirements defined by the United States Department of Energy for Generation IV nuclear energy systems, i.e., proliferation resistance, enhanced safety, improved economics, and waste reduction. An international consortium led by Westinghouse/BNFL was created for development of IRIS reactor; it includes universities, institutes, commercial companies, and utilities. Faculty of Electrical Engineering and Computing, University of Zagreb joined the consortium in year 2001, with the aim to take part in IRIS neutronics design and safety analyses of IRIS transients. A set of neutronic benchmarks for IRIS reactor was defined with the objective to compare results of all participants with exactly the same assumptions. In this paper a calculation of Benchmark 44 for IRIS reactor is described. Benchmark 44 is defined as a core depletion benchmark problem for specified IRIS reactor operating conditions (e.g., temperatures, moderator density) without feedback. Enriched boron, inhomogeneously distributed in axial direction, is used as an integral fuel burnable absorber (IFBA). The aim of this benchmark was to enable a more direct comparison of results of different code systems. Calculations of Benchmark 44 were performed using the modified CORD-2 code package. The CORD-2 code package consists of WIMSD and GNOMER codes. WIMSD is a well-known lattice spectrum calculation code. GNOMER solves the neutron diffusion equation in three-dimensional Cartesian geometry by the Green's function nodal method. The following parameters were obtained in Benchmark 44 analysis: effective multiplication factor as a function of burnup, nuclear peaking factor as a function of burnup, axial offset as a function of burnup, core-average axial power profile, core radial power profile, axial power profile for selected

  4. Prosessiautomaation häiriösuojaus

    OpenAIRE

    Aalto, Joni

    2015-01-01

    Opinnäytetyön tarkoituksena oli tutustua prosessiteollisuuden automaatio- ja ohjausjärjestelmien häiriösuojaukseen ja varmistaa sen oikeanlainen rakenne ja toiminta käytännössä. Työ tehtiin Insta Automation Oy:lle, joka vastaa Boliden Harjavallan sähkökunnossapidosta ja sähkösuunnittelusta. Työ tehtiin Boliden Harjavallan sulaton alueella. Työhön kuului häiriöttömän eli TE-maadoituksen rakenteen tarkastaminen ja mittaus sekä prosessinohjaukseen käytettävän Metso DNA-järjestelmän sähköns...

  5. Preliminary core design of IRIS-50

    International Nuclear Information System (INIS)

    Petrovic, Bojan; Franceschini, Fausto

    2009-01-01

    IRIS-50 is a small, 50 MWe, advanced PWR with integral primary system. It evolved employing the same design principles as the well known medium size (335 MWe) IRIS. These principles include the 'safety-by-design' philosophy, simple and robust design, and deployment flexibility. The 50 MWe design addresses the needs of specific applications (e.g., power generation in small regional grids, water desalination and biodiesel production at remote locations, autonomous power source for special applications, etc.). Such applications may favor or even require longer refueling cycles, or may have some other specific requirements. Impact of these requirements on the core design and refueling strategy is discussed in the paper. Trade-off between the cycle length and other relevant parameters is addressed. A preliminary core design is presented, together with the core main reactor physics performance parameters. (author)

  6. Fuel management approach in IRIS Reactor

    International Nuclear Information System (INIS)

    Petrovic, B.; Franceschini, F.

    2004-01-01

    This paper provides an overview of fuel management approach employed in IRIS (International Reactor Innovative and Secure). It introduces the initial, rather ambitious, fuel management goals and discusses their evolution that reflected the fast pace of progress of the overall project. The updated objectives rely on using currently licensed fuel technology, thus enabling near-term deployment of IRIS, while still providing improved fuel utilization. The paper focuses on the reference core design and fuel management strategy that is considered in pre-application licensing, which enables extended cycle of three to four years. The extended cycle reduces maintenance outage time and increases capacity factor, thus reducing the cost of electricity. Approaches to achieving this goal are discussed, including use of different reloading strategies. Additional fuel management options, which are not part of the licensing process, but are pursued as long-term research for possible future implementation, are presented as well. (Author)

  7. Graphical interpretation of numerical model results

    International Nuclear Information System (INIS)

    Drewes, D.R.

    1979-01-01

    Computer software has been developed to produce high quality graphical displays of data from a numerical grid model. The code uses an existing graphical display package (DISSPLA) and overcomes some of the problems of both line-printer output and traditional graphics. The software has been designed to be flexible enough to handle arbitrarily placed computation grids and a variety of display requirements

  8. IRIS Toxicological Review of Trichloroacetic Acid (TCA) ...

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroacetic acid (TCA) that when finalized will appear on the Integrated Risk Information System (IRIS) database. The draft Toxicological Review of trichloroacetic acid provides scientific support and rationale for the hazard and dose-response assessment pertaining to chronic exposure to trichloroacetic acid.

  9. Unsupervised detection of non-iris occlusions

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Krupička, Mikuláš

    2015-01-01

    Roč. 57, č. 5 (2015), s. 60-65 ISSN 0167-8655 R&D Projects: GA ČR(CZ) GA14-10911S Institutional support: RVO:67985556 Keywords : Iris recognition * Color * Markov random field * Texture Subject RIV: BD - Theory of Information Impact factor: 1.586, year: 2015 http://library.utia.cas.cz/separaty/2015/RO/haindl-0444723.pdf

  10. Outcomes of iris-claw anterior chamber versus iris-fixated foldable intraocular lens in subluxated lens secondary to Marfan syndrome.

    Science.gov (United States)

    Hirashima, Denise E; Soriano, Eduardo S; Meirelles, Rodrigo L; Alberti, Gustave N; Nosé, Walton

    2010-08-01

    To compare the outcome of phacoemulsification using 2 different iris-fixation techniques for intraocular lens (IOL) replacement, a foldable posterior chamber IOL (PCIOL; AcrySof MA60AC, Alcon Laboratories Inc, Fort Worth, TX) and an iris-claw anterior chamber IOL (ACIOL; Artisan, Ophtec BV), for treatment of subluxated lenses in patients with Marfan syndrome (MFS). Randomized, controlled trial. A total of 31 eyes of 16 patients with subluxated lenses associated with MFS and a preoperative corrected visual acuity (CVA) IOL type. Preoperative and postoperative ophthalmologic examination, optical coherence tomography, and endothelial cell counts were performed. We recorded CVA results at 3, 6, and 12 months, complications, endothelial cell loss, and central retinal thickness. In the iris-fixated PCIOL group, CVA was significantly improved at 3 (P = 0.011; n = 16), 6 (P = 0.006; n = 16), and 12 months (P = 0.002; n = 16). In the iris-claw ACIOL group, CVA was significantly improved at 3 (P = 0.001; n=15), 6 (P = 0.001; n = 15), and 12 months (P = 0.009; n = 12). The CVA results did not differ significantly between groups. Dislocation of the IOL occurred in 3 of 16 (18.75%) eyes in the PCIOL group. Retinal detachment occurred in 3 eyes (2 in the PCIOL group and 1 in the ACIOL group) and was successfully repaired. Postoperative foveal tomograms in both groups revealed a decrease in the mean foveal thickness (MFT; IOL dislocation tended to occur more frequently in the iris-fixated PCIOL group, the difference was not significant. At 6 months postoperatively, all study patients tended to have a thinner MFT. None of the patients in either group developed cystoid macular edema. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  11. [Analysis of iris: history and future].

    Science.gov (United States)

    Norn, Mogens

    2003-01-01

    Analysis of the iris has ancient roots, but iridology in its present sense was established by Philippi Meyers in 1670. The discipline was further developed by Ignaz Péczely in 1881 and by Nils Liljequist in 1890. Other studies have been published in Germany, Sweden, Norway, England, France, USA, Australia and elsewhere, and iridology is practiced worldwide. The techniques used are described and the sources of error are mentioned when several photos from the same patient are compared (e.g. the influences of differences in pupil size, magnification and the effect of oblique light). The iris key (irigraphy) and the interpretation of different sights are discussed in some detail; there is little agreement among iridologists. Some iris diagnoses are of little interest to day and some modern diseases are missing in the diagnostic system. Controlled studies reveal that iridology is of no use whatsoever for the detection of cancer and other diseases in the stomach, intestines, kidney, lungs and heart. The reason for the continued popularity of iridology is discussed, and it is concluded that this type of alternative medicine is not harmless.

  12. Developing Federated Services within Seismology: IRIS' involvement in the CoopEUS Project

    Science.gov (United States)

    Ahern, T. K.; Trabant, C. M.; Stults, M.

    2014-12-01

    As a founding member of the CoopEUS initiative, IRIS Data Services has partnered with five data centers in Europe and the UC Berkeley (NCEDC) in the US to implement internationally standardized web services to access seismological data using identical methodologies. The International Federation of Digital Seismograph Networks (FDSN) holds commission status within IASPEI/IUGG and as such is the international body that governs data exchange formats and access protocols within seismology. The CoopEUS project involves IRIS and UNAVCO as part of the EarthScope project and the European collaborators are all members of the European Plate Observing System (EPOS). CoopEUS includes one work package that attempts to coordinate data access between EarthScope and EPOS facilities. IRIS has worked with its partners in the FDSN to develop and adopt three key international service standards within seismology. These include 1) fdsn-dataselect, a service that returns time series data in a variety of standard formats, 2) fdsn-station, a service that returns related metadata about a seismic station in stationXML format, and 3) fdsn-event, a service that returns information about earthquakes and other seismic events in QuakeML format. Currently the 5 European data centers supporting these services include the ORFEUS Data Centre in the Netherlands, the GFZ German Research Centre for Geosciences in Potsdam, Germany, ETH Zurich in Switzerland, INGV in Rome, Italy, and the RESIF Data Centre in Grenoble France. Presently these seven centres can all be accessed using standardized web services with identical service calls and returns results in standardized ways. IRIS is developing an IRIS federator that will allow a client to seamlessly access information across the federated centers. Details and current status of the IRIS Federator will be presented.

  13. VASIR: An Open-Source Research Platform for Advanced Iris Recognition Technologies.

    Science.gov (United States)

    Lee, Yooyoung; Micheals, Ross J; Filliben, James J; Phillips, P Jonathon

    2013-01-01

    The performance of iris recognition systems is frequently affected by input image quality, which in turn is vulnerable to less-than-optimal conditions due to illuminations, environments, and subject characteristics (e.g., distance, movement, face/body visibility, blinking, etc.). VASIR (Video-based Automatic System for Iris Recognition) is a state-of-the-art NIST-developed iris recognition software platform designed to systematically address these vulnerabilities. We developed VASIR as a research tool that will not only provide a reference (to assess the relative performance of alternative algorithms) for the biometrics community, but will also advance (via this new emerging iris recognition paradigm) NIST's measurement mission. VASIR is designed to accommodate both ideal (e.g., classical still images) and less-than-ideal images (e.g., face-visible videos). VASIR has three primary modules: 1) Image Acquisition 2) Video Processing, and 3) Iris Recognition. Each module consists of several sub-components that have been optimized by use of rigorous orthogonal experiment design and analysis techniques. We evaluated VASIR performance using the MBGC (Multiple Biometric Grand Challenge) NIR (Near-Infrared) face-visible video dataset and the ICE (Iris Challenge Evaluation) 2005 still-based dataset. The results showed that even though VASIR was primarily developed and optimized for the less-constrained video case, it still achieved high verification rates for the traditional still-image case. For this reason, VASIR may be used as an effective baseline for the biometrics community to evaluate their algorithm performance, and thus serves as a valuable research platform.

  14. Ignalina NPP Safety Analysis: Models and Results

    International Nuclear Information System (INIS)

    Uspuras, E.

    1999-01-01

    Research directions, linked to safety assessment of the Ignalina NPP, of the scientific safety analysis group are presented: Thermal-hydraulic analysis of accidents and operational transients; Thermal-hydraulic assessment of Ignalina NPP Accident Localization System and other compartments; Structural analysis of plant components, piping and other parts of Main Circulation Circuit; Assessment of RBMK-1500 reactor core and other. Models and main works carried out last year are described. (author)

  15. Prevalence of plateau iris configuration in primary angle closure glaucoma using ultrasound biomicroscopy in the Indian population

    Directory of Open Access Journals (Sweden)

    Gaurav Kumar

    2012-01-01

    Full Text Available Purpose: To report the prevalence of plateau iris in patients with primary angle closure glaucoma (PACG, in North India. Materials and Methods: The patients with PACG, attending the glaucoma services at a tertiary care center in North India were included in the study. All patients had undergone Nd-YAG laser peripheral iridotomy at least four weeks prior to inclusion in the study. Four weeks prior to inclusion in the study, none of the patients had used pilocarpine. Ultrasound Biomicroscopy (UBM images were qualitatively evaluated and plateau iris configuration was defined in an eye if the following criteria were fulfilled in two or more quadrants: anteriorly directed ciliary process supporting the peripheral iris, steep rise of iris root from its point of insertion followed by a downward angulation from the corneoscleral wall, absent ciliary sulcus, and iridotrabecular contact in the same quadrant. Results: One hundred and one eyes were included in the study. There were 63 (62.4% females and 38 (37.6% males. The mean age of the patients was 57.8 ± 9.5 years (range: 42 to 78 years. The mean axial length in the study population was 22.2 ± 1.1 mm. The mean spherical equivalent refraction was 0.06 ± 1.12 D. The mean intraocular pressure was 18.5 ± 4.7 mmHg (range: 12 - 24 mmHg. Twenty-nine (28.7% subjects were diagnosed with plateau iris on the basis of above-defined criteria. Of the 29 eyes, 18 (62.1% subjects had plateau iris in two quadrants, nine (31.03% in three quadrants, and two (6.8% had this configuration in all the four quadrants. Conclusions: Approximately 30% of the eyes with PACG had plateau iris on UBM. Plateau iris was very often the cause for residual angle closure following laser peripheral iridotomy in Indian eyes with PACG.

  16. UV and X-ray Evolution of AR12230 as Observed with IRIS and FOXSI-II

    Science.gov (United States)

    Ryan, Daniel; Christe, Steven; Glesener, Lindsay; Vievering, Julie; Krucker, Sam; Ishikawa, Shin-Nosuke

    2017-08-01

    We present a multi-spectral and spatio-temporal analysis of AR12230 using both UV and X-ray spectroscopic imaging obtained as part of a coordinated observing campaign on 11 December 2014. The campaign involved IRIS (Interface Region Imaging Spectrometer) -- which provides both UV imaging and slit spectrograph observations of optically thick chromospheric and transition region emission -- and FOXSI-II (Focusing Optics X-ray Solar Imager) -- the second in a series of sounding rocket flights which combines grazing incidence direct focusing optics to produce solar X-ray spectroscopic imaging in the range 4-15keV. The active region exhibits a prolonged compact brightening in the IRIS 1330 A and 1400 A slit-jaw channels near the center of the active region throughout the duration of the observations. In the early phase of the observations FOXSI-II shows an X-ray source approximately 20x20 arcsec centered at the same location. The X-ray spectra show the presence of hot (~8 MK) thermal plasma and is suggestive of the presence of non-thermal electrons.. Later, two additional transient, spatially extended, simultaneous brightenings are observed, one of which was captured by the IRIS slit spectrograph. We combine these observations to explore the evolution and topology of the active region. Hydrodynamic modeling of the chromosphere is used to place a limit on the amount of non-thermal electrons required to produce the observed UV emission. This result is then compared to the limit inferred from the FOXSI-II X-ray spectra. Thus, we explore the role of non-thermal electrons and hydrodynamics in the energization and evolution of plasma in active regions.

  17. IRIS TOXICOLOGICAL REVIEW AND SUMMARY ...

    Science.gov (United States)

    The Draft Toxicological Review was developed to evaluate both the cancer and non cancer human health risks from environmental exposure to vinyl chloride. A reference concentration (RfC), and a reference dose (RfD) were developed based upon induction of liver cell polymorphism in a chronic dietary study utilizing Wistar rats. An RfC of 1E-1 mg/m3 and an RfD of 5E-3 mg/kg-d are recommended. On the basis of sufficient evidence for carcinogenicity in human epidemiology studies vinyl chloride is reaffirmed to be a known human carcinogen. Cancer potencies were derived for oral and inhalation exposure. An oral slope factor of 1.3 per (mg/kg-day) for continuous exposure during adulthood and 2.5 per (mg/kg-day) for continuous lifetime exposure from birth, based upon a chronic dietary study in female Wistar rats is recommended; an inhalation unit risk of 4.3 E-6 per (55g/m3) for continuous exposure during adulthood and 8.7 E-6 per (55g/m3) for continuous lifetime exposure from birth is also recommended, based upon exposure of male and female Sprague Dawley rats and Swiss mice, via inhalation, for a lifetime. A PBPK model was used in the derivation of the RfC, RfD, and cancer potency estimates. Its use is based on the assumption that equal tissue concentrations of reactive metabolite, chlorethylene oxide or chloracetaldehyde, at the critical target site will result in equivalent toxicity between species.

  18. Use of PRA techniques to optimize the design of the IRIS nuclear power plant

    International Nuclear Information System (INIS)

    Muhlheim, M.D.; Cletcher, J.W. II

    2003-01-01

    True design optimization of a plants inherent safety and performance characteristics results when a probabilistic risk assessment (PRA) is integrated with the plant-level design process. This is the approach being used throughout the design of the International Reactor Innovative and Secure (IRIS) nuclear power plant to maximize safety. A risk-based design optimization tool employing a 'one-button' architecture is being developed by the Oak Ridge National Laboratory to evaluate design changes; new modeling approaches, methods, or theories modeling uncertainties and completeness; physical assumptions; and data changes on component, cabinet, train, and system bases. Unlike current PRAs, the one-button architecture allows components, modules, and data to be interchanged at will with the probabilistic effect immediately apparent. Because all of the current and previous design, and data sets are available via the one-button architecture, the safety ramifications of design options are evaluated, feedback on design alternatives is immediate, and true optimization and understanding can be achieved. Thus, for the first time, PRA analysts and designers can easily determine the probabilistic implications of different design configurations and operating conditions in various combinations for the entire range of initiating events. The power of the one-button architecture becomes evident by the number of design alternatives that can be evaluated C11 component choices yielded 160 design alternatives. Surprisingly, the lessons learned can be counter-intuitive and significant. For example, one of the alternative designs for IRIS evaluated via this architecture revealed that because of common-cause failure probabilities, using the most reliable components actually decreased systems' reliability. (author)

  19. Gabor Weber Local Descriptor for Bovine Iris Recognition

    OpenAIRE

    Sun, Shengnan; Zhao, Lindu; Yang, Shicai

    2013-01-01

    Iris recognition is a robust biometric technology. This paper proposes a novel local descriptor for bovine iris recognition, named Gabor Weber local descriptor (GWLD). We first compute the Gabor magnitude maps for the input bovine iris image, and then calculate the differential excitation and orientation for each pixel over each Gabor magnitude map. After that, we use these differential excitations and orientations to construct the GWLD histogram representation. Finally, histogram intersectio...

  20. HyspIRI Low Latency Concept and Benchmarks

    Science.gov (United States)

    Mandl, Dan

    2010-01-01

    Topics include HyspIRI low latency data ops concept, HyspIRI data flow, ongoing efforts, experiment with Web Coverage Processing Service (WCPS) approach to injecting new algorithms into SensorWeb, low fidelity HyspIRI IPM testbed, compute cloud testbed, open cloud testbed environment, Global Lambda Integrated Facility (GLIF) and OCC collaboration with Starlight, delay tolerant network (DTN) protocol benchmarking, and EO-1 configuration for preliminary DTN prototype.

  1. Linking International Development Actors to Geophysical Infrastructure: Exploring an IRIS Community Role in Bridging a Communications Gap

    Science.gov (United States)

    Lerner-Lam, A.; Aster, R.; Beck, S.; Ekstrom, G.; Fisher, K.; Meltzer, A.; Nyblade, A.; Sandvol, E.; Willemann, R.

    2008-12-01

    Over the past quarter century, national investments in high-fidelity digital seismograph networks have resulted in a global infrastructure for real-time in situ earthquake monitoring. Many network operators adhere to community-developed standards, with the result that there are few technical impediments to data sharing and real-time information exchange. Two unanswered questions, however, are whether the existing models of international collaboration will ensure the stability and sustainability of global earthquake monitoring, and whether the participating institutions can work with international development agencies and non- governmental organizations in meeting linked development and natural hazard risk reduction goals. Since the 2004 Indian Ocean tsunami, many of these actors are enlarging their commitments to natural hazard risk reduction and building national technical capacities, among broader programs in poverty alleviation and adaptation to environmental stress. Despite this renewed commitment, international development organizations, with notable exceptions, have been relatively passive in discussions of how the existing earthquake monitoring infrastructure could be leveraged to support risk-reduction programs and meet sustainable development goals. At the same time, the international seismological community - comprising universities and government seismological surveys - has built research and education initiatives such as EarthScope, AfricaArray, and similar programs in China, Europe and South America, that use innovative instrumentation technologies and deployment strategies to enable new science and applications, and promote education and training in critical sectors. Can these developments be combined? Recognizing this communication or knowledge gap, the IRIS International Working Group (IWG) explores the link between the activities of IRIS Members using IRIS facilities and the missions of international development agencies, such as US AID, the World

  2. Lentivirus-mediated RNA interference of vascular endothelial growth factor in monkey eyes with iris neovascularization.

    Science.gov (United States)

    Yuan, Meng-Ke; Tao, Yong; Yu, Wen-Zhen; Kai, Wang; Jiang, Yan-Rong

    2010-08-25

    To explore the in vivo anti-angiogenesis effects resulting from lentivirus-mediated RNAi of vascular endothelial growth factor (VEGF) in monkeys with iris neovascularization (INV). Five specific recombinant lentiviral vectors for RNA interference, targeting Macaca mulatta VEGFA, were designed and the one with best knock down efficacy (LV-GFP-VEGFi1) in H1299 cells and RF/6A cells was selected by real-time PCR for in vivo use. A laser-induced retinal vein occlusion model was established in one eye of seven cynomolgus monkeys. In monkeys number 1, 3, and 5 (Group 1), the virus (1x10(8) particles) was intravitreally injected into the preretinal space of the animal's eye immediately after laser coagulation; and in monkeys number 2, 4, and 6 (Group 2), the virus (1x10(8) particles) was injected at 10 days after laser coagulation. In monkey number 7, a blank control injection was performed. In monkeys number 1 and 2, virus without RNAi sequence was used; in monkeys number 3 and 4, virus with nonspecific RNAi sequence was used; and in monkeys 5 and 6, LV-GFP-VEGFi1 was used. In monkey number 5, at 23 days after laser treatment, no obvious INV was observed, while fluorescein angiography of the iris revealed high fluorescence at the margin of pupil and point posterior synechiae. At 50 days after laser treatment, only a slight ectropion uvea was found. However, in the other eyes, obvious INV or hyphema was observed. The densities of new iridic vessels all significantly varied: between monkey number 5 and number 3 (36.01+/-4.49/mm(2) versus 48.68+/-9.30/mm(2), p=0.025), between monkey number 3 and monkey number 7 (48.68+/-9.30/mm(2) versus 74.38+/-9.23/mm(2), p=0.002), and between monkey number 5 and number 7 (36.01+/-4.49/mm(2) versus 74.38+/-9.23/mm(2), p<0.001). Lentivirus-mediated RNAi of VEGF may be a new strategy to treat iris neovascularization, while further studies are needed to investigate the long-term effect.

  3. Microplasticity of MMC. Experimental results and modelling

    International Nuclear Information System (INIS)

    Maire, E.; Lormand, G.; Gobin, P.F.; Fougeres, R.

    1993-01-01

    The microplastic behavior of several MMC is investigated by means of tension and compression tests. This behavior is assymetric : the proportional limit is higher in tension than in compression but the work hardening rate is higher in compression. These differences are analysed in terms of maxium of the Tresca's shear stress at the interface (proportional limit) and of the emission of dislocation loops during the cooling (work hardening rate). On another hand, a model is proposed to calculate the value of the yield stress, describing the composite as a material composed of three phases : inclusion, unaffected matrix and matrix surrounding the inclusion having a gradient in the density of the thermally induced dilocations. (orig.)

  4. Microplasticity of MMC. Experimental results and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Maire, E. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Lormand, G. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Gobin, P.F. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France)); Fougeres, R. (Groupe d' Etude de Metallurgie Physique et de Physique des Materiaux, INSA, 69 Villeurbanne (France))

    1993-11-01

    The microplastic behavior of several MMC is investigated by means of tension and compression tests. This behavior is assymetric : the proportional limit is higher in tension than in compression but the work hardening rate is higher in compression. These differences are analysed in terms of maxium of the Tresca's shear stress at the interface (proportional limit) and of the emission of dislocation loops during the cooling (work hardening rate). On another hand, a model is proposed to calculate the value of the yield stress, describing the composite as a material composed of three phases : inclusion, unaffected matrix and matrix surrounding the inclusion having a gradient in the density of the thermally induced dilocations. (orig.).

  5. Multispectral diagnostic imaging of the iris in pigment dispersion syndrome.

    Science.gov (United States)

    Roberts, Daniel K; Lukic, Ana; Yang, Yongyi; Wilensky, Jacob T; Wernick, Miles N

    2012-08-01

    To determine if wavelength selection with near infrared iris imaging may enhance iris transillumination defects (ITDs) in pigment dispersion syndrome. An experimental apparatus was used to acquire iris images in 6 African-American (AA) and 6 White patients with pigment dispersion syndrome. Light-emitting diode probes of 6 different spectral bands (700 to 950 nm) were used to project light into patients' eyes. Iris patterns were photographed, ITD regions of interest were outlined, and region of interest contrasts were calculated for each spectral band. Contrasts varied as a function of wavelength (Ppigmented eyes may be slightly longer than for less pigmented eyes.

  6. Iris Transponder-Communications and Navigation for Deep Space

    Science.gov (United States)

    Duncan, Courtney B.; Smith, Amy E.; Aguirre, Fernando H.

    2014-01-01

    The Jet Propulsion Laboratory has developed the Iris CubeSat compatible deep space transponder for INSPIRE, the first CubeSat to deep space. Iris is 0.4 U, 0.4 kg, consumes 12.8 W, and interoperates with NASA's Deep Space Network (DSN) on X-Band frequencies (7.2 GHz uplink, 8.4 GHz downlink) for command, telemetry, and navigation. This talk discusses the Iris for INSPIRE, it's features and requirements; future developments and improvements underway; deep space and proximity operations applications for Iris; high rate earth orbit variants; and ground requirements, such as are implemented in the DSN, for deep space operations.

  7. Spatula scaffold: An iris-sparing technique for lensectomy.

    Science.gov (United States)

    Narang, Priya; Agarwal, Amar

    2017-12-01

    Lensectomy with vitrectomy is often performed for crystalline lenticular subluxation. We report a new technique and a practical approach that involves the placement of a spatula beneath the iris tissue that facilitates retroiridial removal of subluxated lens and acts as a scaffold by protecting the iris tissue from being accidentally trapped into the vitrectomy cutter port. Our technique facilitates management of the lens and vitreous without any trauma to the iris and secondarily obviates the need to perform an iris repair procedure that may arise due to iatrogenic reasons.

  8. Iris recognition as a biometric method after cataract surgery.

    Science.gov (United States)

    Roizenblatt, Roberto; Schor, Paulo; Dante, Fabio; Roizenblatt, Jaime; Belfort, Rubens

    2004-01-28

    Biometric methods are security technologies, which use human characteristics for personal identification. Iris recognition systems use iris textures as unique identifiers. This paper presents an analysis of the verification of iris identities after intra-ocular procedures, when individuals were enrolled before the surgery. Fifty-five eyes from fifty-five patients had their irises enrolled before a cataract surgery was performed. They had their irises verified three times before and three times after the procedure, and the Hamming (mathematical) distance of each identification trial was determined, in a controlled ideal biometric environment. The mathematical difference between the iris code before and after the surgery was also compared to a subjective evaluation of the iris anatomy alteration by an experienced surgeon. A correlation between visible subjective iris texture alteration and mathematical difference was verified. We found only six cases in which the eye was no more recognizable, but these eyes were later reenrolled. The main anatomical changes that were found in the new impostor eyes are described. Cataract surgeries change iris textures in such a way that iris recognition systems, which perform mathematical comparisons of textural biometric features, are able to detect these changes and sometimes even discard a pre-enrolled iris considering it an impostor. In our study, re-enrollment proved to be a feasible procedure.

  9. A gallery approach for off-angle iris recognition

    Science.gov (United States)

    Karakaya, Mahmut; Yoldash, Rashiduddin; Boehnen, Christopher

    2015-05-01

    It has been proven that hamming distance score between frontal and off-angle iris images of same eye differs in iris recognition system. The distinction of hamming distance score is caused by many factors such as image acquisition angle, occlusion, pupil dilation, and limbus effect. In this paper, we first study the effect of the angle variations between iris plane and the image acquisition systems. We present how hamming distance changes for different off-angle iris images even if they are coming from the same iris. We observe that increment in acquisition angle of compared iris images causes the increment in hamming distance. Second, we propose a new technique in off-angle iris recognition system that includes creating a gallery of different off-angle iris images (such as, 0, 10, 20, 30, 40, and 50 degrees) and comparing each probe image with these gallery images. We will show the accuracy of the gallery approach for off-angle iris recognition.

  10. Extending the imaging volume for biometric iris recognition.

    Science.gov (United States)

    Narayanswamy, Ramkumar; Johnson, Gregory E; Silveira, Paulo E X; Wach, Hans B

    2005-02-10

    The use of the human iris as a biometric has recently attracted significant interest in the area of security applications. The need to capture an iris without active user cooperation places demands on the optical system. Unlike a traditional optical design, in which a large imaging volume is traded off for diminished imaging resolution and capacity for collecting light, Wavefront Coded imaging is a computational imaging technology capable of expanding the imaging volume while maintaining an accurate and robust iris identification capability. We apply Wavefront Coded imaging to extend the imaging volume of the iris recognition application.

  11. Modelling and observation of transionospheric propagation results from ISIS II in preparation for ePOP

    Directory of Open Access Journals (Sweden)

    R. G. Gillies

    2007-02-01

    Full Text Available The enhanced Polar Outflow Probe (ePOP is scheduled to be launched as part of the Cascade Demonstrator Small-Sat and Ionospheric Polar Explorer (CASSIOPE satellite in early 2008. A Radio Receiver Instrument (RRI on ePOP will receive HF transmissions from various ground-based transmitters. In preparation for the ePOP mission, data from a similar transionospheric experiment performed by the International Satellites for Ionospheric Studies (ISIS II satellite has been studied. Prominent features in the received 9.303-MHz signal were periodic Faraday fading of signal intensity at rates up to 13 Hz and a time of arrival delay between the O- and X-modes of up to 0.8 ms. Both features occurred when the satellite was above or south of the Ottawa transmitter. Ionospheric models for ray tracing were constructed using both International Reference Ionosphere (IRI profiles and local peak electron density values from ISIS ionograms. Values for fade rate and differential mode delay were computed and compared to the values observed in the ISIS II data. The computed values showed very good agreement to the observed values of both received signal parameters when the topside sounding foF2 values were used to scale IRI profiles, but not when strictly modelled IRI profiles were used. It was determined that the primary modifier of the received signal parameters was the foF2 density and not the shape of the profile. This dependence was due to refraction, at the 9.303-MHz signal frequency, causing the rays to travel larger distances near the peak density where essentially all the mode splitting occurred. This study should assist in interpretation of ePOP RRI data when they are available.

  12. Survey of HTR related research at IRI, Delft, Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Hoogenboom, J.E.; Wallerbos, E.J.M.; Van der Hagen, T.H.J.J.; Van Dam, H. [Interfaculty Reactor Institute IRI, Delft University of Technology, Delft (Netherlands); Tuerkcan, E. [ECN Nuclear Research, Petten (Netherlands)

    1998-09-01

    High temperature helium-cooled reactors have a large potential for inherent safety. Therefore, several projects on HTR research are being carried out or were carried out at the Interfaculty Reactor Institute (IRI) of the Delft University of Technology in Delft, Netherlands. As part of a larger research programme measurements of core reactivity, reactivity worth of safety rods and of small samples being oscillated in the reactor core were carried out at the PROTEUS facility of the Paul Scherrer Institute at Villigen, Switzerland. Together with other partners in the Netherlands a small inherently safe co-generation plant with a pebble-bed HTR core was designed and analysed. It was verified that such a reactor can operate continuously for 10 years by adding continuously fuel pebbles until the maximum available core height is reached. As a new, innovative, inherently safe reactor type the design of a fluidized-bed reactor with coated fuel particles on a helium gas stream is discussed and results are shown for the analysis of inherent criticality safety under varying coolant flow rates. IRI is also taking part in the new IAEA Co-ordinated Research Programme, which involves participation in the start-up experiments of the Japanese HTTR and carrying out calculations for the core physics benchmark test. 11 refs.

  13. Graphite analyser upgrade for the IRIS spectrometer at ISIS

    International Nuclear Information System (INIS)

    Campbell, S.I.; Telling, M.T.F.; Carlile, C.J.

    1999-01-01

    Complete text of publication follows. The pyrolytic graphite (PG) analyser bank on the IRIS high resolution inelastic spectrometer [1] at ISIS is to be upgraded. At present the analyser consists of 1350 graphite pieces (6 rows by 225 columns) cooled to 25K [2]. The new analyser array, however, will provide a three-fold increase in area and employ 4212 crystal pieces (18 rows by 234 columns). In addition, the graphite crystals will be cooled close to liquid helium temperature to further reduce thermal diffuse scattering (TDS) and improve the sensitivity of the spectrometer [2]. For an instrument such as IRIS, with its analyser in near back-scattering geometry, optical aberration and variation in the time-of-flight of the analysed neutrons is introduced as one moves out from the horizontal scattering plane. To minimise such effects, the profile of the analyser array has been redesigned. The concept behind the design of the new analyser bank and factors that effect the overall resolution of the instrument are discussed. Results of Monte Carlo simulations of the expected resolution and intensity of the complete instrument are presented and compared to the current instrument performance. (author) [1] C.J. Carlile et al, Physica B 182 (1992) 431-440.; [2] C.J. Carlile et al, Nuclear Instruments and Methods In Physics Research A 338 (1994) 78-82

  14. Intraoperative floppy iris syndrome (IFIS): a practical approach to medical and surgical considerations in cataract extractions

    DEFF Research Database (Denmark)

    Storr-Paulsen, Allan; Nørregaard, Jens Christian; Børme, Kim Kamp

    2009-01-01

    Abstract. Intraoperative floppy iris syndrome (IFIS) during cataract surgery is characterized by iris fluttering, iris prolapse towards the incisions, and a progressive pupillary constriction leading to high rates of complications. The syndrome has been reported following the treatment of benign...

  15. TB-IRIS and remodelling of the T cell compartment in highly immunosuppressed HIV+ patients with TB: the CAPRI T (ANRS-12614) study

    Science.gov (United States)

    Haridas, V.; Pean, P.; Jasenosky, L.D.; Madec, Y.; Laureillard, D.; Sok, T.; Sath, S.; Borand, L.; Marcy, O.; Chan, S.; Tsitsikov, E.; Delfraissy, J.-F.; Blanc, F.-X.; Goldfeld, A.E.

    2015-01-01

    Objective To investigate the impact of tuberculosis (TB)-associated immune reconstitution syndrome (IRIS) upon immunological recovery and the T cell compartment after initiation of TB and antiretroviral therapy (ART). Design and methods We prospectively evaluated T cell immunophenotypes by flow cytometry and cytokines by Luminex assays in a subset (n=154) of highly immunosuppressed HIV+ patients with TB from the CAMELIA randomized clinical trial. We compared findings from patients who developed TB-IRIS to findings from patients who did not develop TB-IRIS. Data were evaluated with mixed effect linear regression, Kaplan-Meier estimates, and Wilcoxon rank sum tests, and q-values were calculated to control for multiple comparisons. Results Development of TB-IRIS was associated with significantly greater pre-ART frequencies of HLA-DR+CD45RO+CD4+, CCR5+CD4+, OX40+CD4+, and Fas+ effector memory (EM) CD8+ T cells, and significantly elevated levels of plasma IL-6, IL-1β, IL-8, and IL-10 and viral load. Post-ART initiation, EM CD4+ and Fas+ EM CD4+ T cell frequencies significantly expanded, and central memory (CM) CD4+ T cell frequencies significantly contracted in patients who experienced TB-IRIS. By week 34 post-TB treatment initiation, EM/CM CD4+ T cell ratios were markedly higher in TB-IRIS versus non-TB-IRIS patients. Conclusions A distinct pattern of pre-ART T cell and cytokine markers appear to poise the immune response to develop TB-IRIS. Experience of TB-IRIS is then associated with long-term remodeling of the CD4+ T cell memory compartment towards an EM-dominated phenotype. We speculate that these pre- and post-ART TB-IRIS-associated immune parameters may contribute to superior immune control of TB/HIV co-infection and better clinical outcome. PMID:25486415

  16. Iris abscess a rare presentation of intravenous drug abuse associated Candida endophthalmitis

    Directory of Open Access Journals (Sweden)

    Jonathan Pierce

    2016-12-01

    Conclusions and importance: An iris abscess is a rare clinical presentation of intravenous drug use-associated endogenous endophthalmitis and as a result may present a diagnostic challenge as it requires a high level of clinical suspicion and a detailed social history to elicit the drug abuse. Early diagnosis and aggressive therapy is the key to better visual outcomes in these patients.

  17. Effect of tamsulosin on iris vasculature and morphology.

    Science.gov (United States)

    Shtein, Roni M; Hussain, Munira T; Cooney, Theresa M; Elner, Victor M; Hood, Christopher T

    2014-05-01

    To determine whether preoperative iris vasculature and morphology are altered in patients who have taken tamsulosin (Flomax). Academic multispecialty practice. Case series. Patients with current or past tamsulosin use and age- and sex-matched control patients were included. Anterior segment optical coherence tomography (AS-OCT) and iris fluorescein angiography were performed to measure iris vasculature and thickness before cataract surgery. Data collected at surgery included pupil diameter, clinical signs of intraoperative floppy-iris syndrome, and surgical complications. Tamsulosin was currently used by 16 patients and in the past by 4 patients; the control group comprised 10 patients. Pharmacologically dilated pupil diameter was statistically significantly smaller preoperatively and immediately postoperatively in the tamsulosin group than in the control group (P=.009 and P=.003, respectively). There was a statistically significant decrease in pupil size intraoperatively in the tamsulosin group (P=.05) but not in the control group (P=.3). Iris-vasculature parameters, specifically time to first vessel fill and percentage of vessel fill on iris fluorescein angiography, were not significantly different between the 2 groups. The AS-OCT measurements of iris morphology were not statistically significantly different between the groups. No surgical complications occurred. No fluorescein dye leakage, staining, or other vascular anomalies were observed. Although there were differences in pupil measurements and intraoperative iris behavior between patients who had been on tamsulosin and control patients, there were no significant differences in iris vasculature on iris fluorescein angiography or in iris morphology on AS-OCT. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  18. MMP-9 immunohistochemical expression is correlated with histologic grade in feline diffuse iris melanoma

    Directory of Open Access Journals (Sweden)

    Laura Nordio

    2018-06-01

    Full Text Available Feline diffuse iris melanoma (FDIM is the most common primary intraocular neoplasm in cats. It is usually a malignant tumor, even if slowly progressive, thus representing an unique spontaneous model of the aggressive, although rare, human iris melanoma. In cats, the extent of the tumor within the eye, expressed as histological grade, is considered a good predictor of survival. In the context of the neoplastic cells-tumor microenvironment interaction, Matrix Metalloproteinase-9 (MMP-9 is an endopeptidase able to digest the extracellular matrix with involvement in tumor invasion . MMP-9 expression has been positively correlated with metastasizing behavior in human posterior uveal melanoma. The present study investigates the expression of MMP-9 in a caseload of formalin-fixed paraffin-embedded FDIMs in relation to the histological grade  and mitotic index (MI (threshold=7/10 hpf. Sixty-one samples of FDIM evaluated on light microscopy (Fig. 1 were selected (grade I n=22, grade II n=20, grade III n=19. Immunohistochemical staining with standard ABC method was performed using a mouse anti-MMP-9 antibody. Results were semi-quantitatively scored and compared by Mann-Whitney U test. MMP-9 was expressed in 59,1% grade I FDIM, 90,0% grade II and 80,0% grade III. Tumors with MMP-9 expression in more than 50% of neoplastic cells were 13,6% in grade I cases, 40,0% in grade II and 36,8% in grade III. MMP-9 was expressed in 71,4% of FDIM with MI≤7 and 92,3% of FDIM with MI>7. MMP-9 expression differed significantly between grade I and the other two grades, and between groups with low and high MI. In conclusion, intense expression of MMP-9 seems to correlate with the histological aggressiveness of FDIM.

  19. Relations between CT perfusion parameters and degree of hepatic ischemia reperfusion injury in a rabbit model

    International Nuclear Information System (INIS)

    Guo Chengwei; Shen Sandi; Yi Xianlin; Zhang Zhonglin; Liu Zaiyi; Liang Changhong

    2011-01-01

    Objective: To observe the changes of hepatic CT perfusion parameters and their correlation with serum aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) in a rabbit hepatic ischemia reperfusion injury (IRI) model. Methods: Hepatic IRI was produced in rabbits by inducing left liver lobe ischemia (60 min) followed by 6 h, 12 h and 24 h reperfusion (6 rabbits were used for each reperfusion interval). Additional 6 rabbits were served as sham-operated controls. All the rabbits were scanned with a dynamic iCT protocol. Blood samples were taken from the superior mesenteric vein to measure the levels of serum amylase (ALT, AST, and ALP) in various groups, and liver samples were taken for histological examinations after scanning. One-way analysis of variance (ANOVA) was used to determine differences between groups. The correlations of CT perfusion parameters with serum levels were analyzed using Pearson correlation coefficient. Results: Heterogeneity of CT perfusion patterns appeared in the 6 h groups, which presented as low enhanced area [(25.1±9.3) ml · min -1 · 100 mg -1 ]. In reduced perfusion regions of IRI group, HAP of 12 h IRI group [(19.5± 13.6) ml · min -1 · 100 mg -1 ], 24 h IRI group (8.0±2.7) ml · min -1 · 100 mg -1 ], HPP of 6 h IRI group [(10.8±5.5) ml · min -1 · 100 mg -1 ], 12 h IRI group [(14.4±5.2) ml · min -1 · 100 mg -1 ] , 24 h IRI group [(7.8±3.3) ml · min -1 · 100 mg -1 ] and TLP of 6 h IRI group [(35.9±14.0) ml · min -1 · 100 mg -1 ], 12 h IRI group [(33.9±16.1) ml · min -1 · 100 mg -1 ], 24 h IRI group [(16.0± 5.5) ml · min -1 · 100 mg -1 ] were lower than those of sham group [HAP (21.2±10.5) ml · min -1 · 100 mg -1 , HPP (63.5±24.0) ml · min -1 · 100 mg -1 , TLP (81.4±24.8) ml · min -1 · 100 mg -1 ] (F=8.376, 25.950, 16.925, P<0.01). However, HPI of 6 h IRI group [(65.9±3.9)%], 12 h IRI group [(54.2±16.7)%], and 24 h IRI group [(48.9±10.0)%] were higher compared to sham

  20. An unusual case of seed dispersal in an invasive aquatic; yellow flag iris (Iris pseudacorus)

    Science.gov (United States)

    Understanding reproductive mode of invasive plants can help managers plan more efficacious control. Invasive aquatics typically reproduce primarily through vegetative means. Yellow flag iris is an invasive plant species often growing as an emergent aquatic. There have been contradictory reports of i...

  1. Hyperspectral optical imaging of human iris in vivo: characteristics of reflectance spectra

    Science.gov (United States)

    Medina, José M.; Pereira, Luís M.; Correia, Hélder T.; Nascimento, Sérgio M. C.

    2011-07-01

    We report a hyperspectral imaging system to measure the reflectance spectra of real human irises with high spatial resolution. A set of ocular prosthesis was used as the control condition. Reflectance data were decorrelated by the principal-component analysis. The main conclusion is that spectral complexity of the human iris is considerable: between 9 and 11 principal components are necessary to account for 99% of the cumulative variance in human irises. Correcting image misalignments associated with spontaneous ocular movements did not influence this result. The data also suggests a correlation between the first principal component and different levels of melanin present in the irises. It was also found that although the spectral characteristics of the first five principal components were not affected by the radial and angular position of the selected iridal areas, they affect the higher-order ones, suggesting a possible influence of the iris texture. The results show that hyperspectral imaging in the iris, together with adequate spectroscopic analyses provide more information than conventional colorimetric methods, making hyperspectral imaging suitable for the characterization of melanin and the noninvasive diagnosis of ocular diseases and iris color.

  2. Dom IRIS in njegova vloga v rehabilitaciji: Smart Home IRIS and its role in rehabilitation: Smart Home IRIS and its role in rehabilitation:

    OpenAIRE

    Jenko, Mojca; Ocepek, Julija; Zupan, Anton

    2010-01-01

    Smart Home IRIS is a demonstrative apartment, founded in 2008 on the basis of numerous European smart home projects. The aim of this study was to establish the role of Smart Home IRIS in improving quality of life for persons with disabilities and elderly in Slovenia and the satisfaction of persons who have already been involved in a treatment in it. We analyzed a satisfaction questionnaire of the treatment in Smart Home IRIS, sent to all patients in 2008 (79 in total), as well as the problems...

  3. Improvement of selected indication methods with plants for the surveying network of air pollution in Lower Saxony. Pt. 1. Iris hollandica for biological monitoring. Optimierung ausgewaehlter pflanzlicher Indikationsverfahren im Luftguete-Ueberwachungsnetz des Landes Niedersachsen. T. 1. Iris hollandica als Bioindikator

    Energy Technology Data Exchange (ETDEWEB)

    Koester, W; Merkel, D

    1985-12-01

    Verification of a biological monitoring method for heavy metal accumulation with Iris hollandica. With Iris hollandica, fluoride immissions can be registered proportionally as with rye grass. Fluoride concentrations in the dry matter of rye grass, however, are always greater than in Iris hollandica. Cultivation of Iris hollandica in soil is advantageous as compared to cultivation in hydroponic. The exposition of iris plants, aged 6-8 weeks, for a period of 14 days is recommended. There were positive results from experiments to monitor the deposition of lead and cadmium with this method. Effects of fluoride immissions on the fruit trees apple, pear and plum in the neighborhood of an aluminium plant were investigated. (orig./KG) With 26 tabs., 8 figs.

  4. Score level fusion scheme based on adaptive local Gabor features for face-iris-fingerprint multimodal biometric

    Science.gov (United States)

    He, Fei; Liu, Yuanning; Zhu, Xiaodong; Huang, Chun; Han, Ye; Chen, Ying

    2014-05-01

    A multimodal biometric system has been considered a promising technique to overcome the defects of unimodal biometric systems. We have introduced a fusion scheme to gain a better understanding and fusion method for a face-iris-fingerprint multimodal biometric system. In our case, we use particle swarm optimization to train a set of adaptive Gabor filters in order to achieve the proper Gabor basic functions for each modality. For a closer analysis of texture information, two different local Gabor features for each modality are produced by the corresponding Gabor coefficients. Next, all matching scores of the two Gabor features for each modality are projected to a single-scalar score via a trained, supported, vector regression model for a final decision. A large-scale dataset is formed to validate the proposed scheme using the Facial Recognition Technology database-fafb and CASIA-V3-Interval together with FVC2004-DB2a datasets. The experimental results demonstrate that as well as achieving further powerful local Gabor features of multimodalities and obtaining better recognition performance by their fusion strategy, our architecture also outperforms some state-of-the-art individual methods and other fusion approaches for face-iris-fingerprint multimodal biometric systems.

  5. Grading of Iris Color with an Extended Photographic Reference Set

    Directory of Open Access Journals (Sweden)

    Luuk Franssen

    2008-01-01

    Conclusion: The new method is promising to be more accurate than existing iris color classification systems in clinical situations where objective colorimetry-based systems are not available. The method may be useful to assess iris translucency and fundus reflectance as sources of variation in retinal straylight.

  6. Driving Simulator study for intelligent cooperative intersection safety system (IRIS)

    NARCIS (Netherlands)

    Vreeswijk, J.; Schendzielorz, T.; Mathias, P.; Feenstra, P.

    2008-01-01

    About forty percent of all accidents occur at intersections. The Intelligent Cooperative Intersection Safety system (IRIS), as part of the European research project SAFESPOT, is a roadside application and aims at minimizing the number of accidents at controlled and uncontrolled intersections. IRIS

  7. An enhanced iris recognition and authentication system using ...

    African Journals Online (AJOL)

    Iris recognition and authentication has a major issue in its code generation and verification accuracy, in order to enhance the authentication process, a binary bit sequence of iris is generated, which contain several vital information that is used to calculate the Mean Energy and Maximum Energy that goes into the eye with an ...

  8. IRIS Toxicological Review of Ammonia (Revised External Review Draft)

    Science.gov (United States)

    In August 2013, EPA submitted a revised draft IRIS assessment of ammonia to the agency's Science Advisory Board (SAB) and posted this draft on the IRIS website. EPA had previously released a draft of the assessment for public comment, held a public meeting about the draft, and ...

  9. Retropupillary Fixation of Iris-Claw Intraocular Lens for Aphakic Eyes in Children

    Science.gov (United States)

    Brandner, Martina; Thaler-Saliba, Sarah; Plainer, Sophie; Vidic, Bertram; El-Shabrawi, Yosuf; Ardjomand, Navid

    2015-01-01

    Purpose To report outcome, complications and safety of retropupillary fixated iris-claw intraocular lenses in a pediatric population. Design Retrospective study. Patients and Methods Ten consecutive pediatric patients (15 eyes) underwent placement of retropupillary fixated iris-claw intraocular lenses between October 2007 and July 2013 at the Department of Ophthalmology, Medical University Graz and General Hospital Klagenfurt, Austria. Postoperative visual acuity and complications were analyzed. Results Median final best-corrected visual acuity improved by 0.12 logMAR from preoperative baseline. Mean postoperative spherical equivalent was -0.05 ± 1.76 D. No serious complications were observed intra- or postoperatively during the entire follow-up period of up to 40 months. One patient experienced a haptic disenclavation with IOL subluxation immediately after a car accident. Conclusion Our study demonstrates that iris-claw intraocular lens implantation behind the iris is safe in children with lack of capsular support and yields excellent visual outcome with low complication rate. PMID:26110864

  10. Retropupillary iris-claw intraocular lens for the surgical correction of aphakia in cases with microspherophakia

    Directory of Open Access Journals (Sweden)

    Sameh Mosaad Fouda

    2016-01-01

    Full Text Available Purpose: This study aimed to evaluate the safety and efficacy of retropupillary fixation of an iris-claw intraocular lens (IOL; Verisyse polymethyl methacrylate IOL, Abbott Medical Optics [AMO], Netherlands for the surgical correction of aphakia in microspherophakic eyes without sufficient capsular support. Design: This was a prospective, interventional, noncomparative case series. Methods: This interventional case series comprised 17 eyes of 9 microspherophakic patients. Retropupillary fixation of the Verisyse iris-claw IOL (AMO was performed in all cases. The surgical time was measured. Corrected distance visual acuity, astigmatism, intraocular pressure (IOP, tissue reaction, pigment dispersion, and stability of the IOL were studied 1 day, 3 days, 1 week, 2 weeks, 1 month, and 6 months postoperatively. Results: Eight patients had familial microspherophakia and one patient had Marfan's syndrome. Eighty-two percent of the cases achieved a visual acuity of 0.3 or better. There was no significant postoperative inflammatory reaction. Transient elevation of IOP was recorded in two cases in the 1st week only. One IOL developed disengagement of one of the haptics from the iris and was successfully re-engaged. All the other IOLs were well centered and stable. The mean surgical time was 18.0 ± 4.5 min. Conclusions: Retropupillary fixation of an iris-claw IOL is a safe and effective procedure that provides early visual recovery. It is also a time-saving method for correcting aphakia in microspherophakic eyes without sufficient capsular support.

  11. Extending the Capture Volume of an Iris Recognition System Using Wavefront Coding and Super-Resolution.

    Science.gov (United States)

    Hsieh, Sheng-Hsun; Li, Yung-Hui; Tien, Chung-Hao; Chang, Chin-Chen

    2016-12-01

    Iris recognition has gained increasing popularity over the last few decades; however, the stand-off distance in a conventional iris recognition system is too short, which limits its application. In this paper, we propose a novel hardware-software hybrid method to increase the stand-off distance in an iris recognition system. When designing the system hardware, we use an optimized wavefront coding technique to extend the depth of field. To compensate for the blurring of the image caused by wavefront coding, on the software side, the proposed system uses a local patch-based super-resolution method to restore the blurred image to its clear version. The collaborative effect of the new hardware design and software post-processing showed great potential in our experiment. The experimental results showed that such improvement cannot be achieved by using a hardware-or software-only design. The proposed system can increase the capture volume of a conventional iris recognition system by three times and maintain the system's high recognition rate.

  12. [Cyclorotation of the eye in wavefront-guided LASIK using a static eyetracker with iris recognition].

    Science.gov (United States)

    Kohnen, T; Kühne, C; Cichocki, M; Strenger, A

    2007-01-01

    Centration of the ablation zone decisively influences the result of wavefront-guided LASIK. Cyclorotation of the eye occurs as the patient changes from the sitting position during aberrometry to the supine position during laser surgery and may lead to induction of lower and higher order aberrations. Twenty patients (40 eyes) underwent wavefront-guided LASIK (B&L 217z 100 excimer laser) with a static eyetracker driven by iris recognition (mean preoperative SE: -4.72+/-1.45 D; range: -1.63 to -7.00 D). The iris patterns of the patients' eyes were memorized during aberrometry and after flap creation. The mean absolute value of the measured cyclorotation was -1.5+/-4.2 degrees (range: -11.0 to 6.9 degrees ). The mean cyclorotation was 3.5+/-2.7 masculine (range: 0.1 to 11.0 degrees ). In 65% of all eyes cyclorotation was >2 masculine. A static eyetracker driven by iris recognition demonstrated that cyclorotation of up to 11 degrees may occur in myopic and myopic astigmatic eyes when changing from a sitting to a supine position. Use of static eyetrackers with iris recognition may provide a more precise positioning of the ablation profile as they detect and compensate cyclorotation.

  13. Multi-image encryption based on synchronization of chaotic lasers and iris authentication

    Science.gov (United States)

    Banerjee, Santo; Mukhopadhyay, Sumona; Rondoni, Lamberto

    2012-07-01

    A new technique of transmitting encrypted combinations of gray scaled and chromatic images using chaotic lasers derived from Maxwell-Bloch's equations has been proposed. This novel scheme utilizes the general method of solution of a set of linear equations to transmit similar sized heterogeneous images which are a combination of monochrome and chromatic images. The chaos encrypted gray scaled images are concatenated along the three color planes resulting in color images. These are then transmitted over a secure channel along with a cover image which is an iris scan. The entire cryptology is augmented with an iris-based authentication scheme. The secret messages are retrieved once the authentication is successful. The objective of our work is briefly outlined as (a) the biometric information is the iris which is encrypted before transmission, (b) the iris is used for personal identification and verifying for message integrity, (c) the information is transmitted securely which are colored images resulting from a combination of gray images, (d) each of the images transmitted are encrypted through chaos based cryptography, (e) these encrypted multiple images are then coupled with the iris through linear combination of images before being communicated over the network. The several layers of encryption together with the ergodicity and randomness of chaos render enough confusion and diffusion properties which guarantee a fool-proof approach in achieving secure communication as demonstrated by exhaustive statistical methods. The result is vital from the perspective of opening a fundamental new dimension in multiplexing and simultaneous transmission of several monochromatic and chromatic images along with biometry based authentication and cryptography.

  14. Genome-wide association study of pigmentary traits (skin and iris color in individuals of East Asian ancestry

    Directory of Open Access Journals (Sweden)

    Lida Rawofi

    2017-11-01

    Full Text Available Background Currently, there is limited knowledge about the genetics underlying pigmentary traits in East Asian populations. Here, we report the results of the first genome-wide association study of pigmentary traits (skin and iris color in individuals of East Asian ancestry. Methods We obtained quantitative skin pigmentation measures (M-index in the inner upper arm of the participants using a portable reflectometer (N = 305. Quantitative measures of iris color (expressed as L*, a* and b* CIELab coordinates were extracted from high-resolution iris pictures (N = 342. We also measured the color differences between the pupillary and ciliary regions of the iris (e.g., iris heterochromia. DNA samples were genotyped with Illumina’s Infinium Multi-Ethnic Global Array (MEGA and imputed using the 1000 Genomes Phase 3 samples as reference haplotypes. Results For skin pigmentation, we did not observe any genome-wide significant signal. We followed-up in three independent Chinese samples the lead SNPs of five regions showing multiple common markers (minor allele frequency ≥ 5% with good imputation scores and suggestive evidence of association (p-values < 10−5. One of these markers, rs2373391, which is located in an intron of the ZNF804B gene on chromosome 7, was replicated in one of the Chinese samples (p = 0.003. For iris color, we observed genome-wide signals in the OCA2 region on chromosome 15. This signal is driven by the non-synonymous rs1800414 variant, which explains 11.9%, 10.4% and 6% of the variation observed in the b*, a* and L* coordinates in our sample, respectively. However, the OCA2 region was not associated with iris heterochromia. Discussion Additional genome-wide association studies in East Asian samples will be necessary to further disentangle the genetic architecture of pigmentary traits in East Asian populations.

  15. Retrospective Evaluation of Topical Bimatoprost and Iris Pigmentation Change.

    Science.gov (United States)

    Zaleski-Larsen, Lisa A; Ruth, Nadine H; Fabi, Sabrina G

    2017-12-01

    Topical bimatoprost is a topical prostaglandin analog originally used to treat glaucoma and more recently used to cosmetically induce hypertrichosis of the eyelashes. Iris pigmentation change has been noted in the treatment of glaucoma but has not been assessed with the cosmetic periorbital application of bimatoprost. To evaluate for iris pigmentation change with the long-term cosmetic use of topical bimatoprost. A retrospective chart review in a cosmetic dermatology practice of women (N = 50) who consistently purchased topical bimatoprost over an average of 4.59 years was compared with that of age-matched non-bimatoprost patients (N = 50). A blinded evaluator assessed each patient for iris pigmentary change. No iris pigmentation change was noted with the cutaneous application of bimatoprost. The cutaneous application of bimatoprost appears to be safe with minimal risk for iris pigmentation change.

  16. Simultaneous correction of post-traumatic aphakia and aniridia with the use of artificial iris and IOL implantation.

    Science.gov (United States)

    Forlini, Cesare; Forlini, Matteo; Rejdak, Robert; Prokopiuk, Agata; Levkina, Oxana; Bratu, Adriana; Rossini, Paolo; Cagampang, Perfecto R; Cavallini, Gian Maria

    2013-03-01

    Combined post-traumatic aniridia and aphakia demand extensive and complex reconstructive surgery. We present our approach for simultaneous correction of this surgical situation with the use of the ArtificialIris (Dr. Schmidt Intraocularlinsen GmbH, Germany) with a foldable acrylic IOL Lentis L-313 (Oculentis, GmbH, Germany) sutured to its surface. The novelty (our first operation was on June 2010) of this surgical technique is based on the combined use of foldable (with closed haptics) IOL and Artificialiris to correct post-traumatic aniridia and aphakia. Four consecutive cases of combined post-traumatic lesions of iris and lens, corrected with complex device ArtificialIris and foldable IOL. In two cases, the compound implant was sutured to the sclera in sulcus during the penetrating keratoplasty; in another case, it was positioned through a corneal incision of about 5.0 mm with transscleral fixation, and in one patient with preserved capsular support and possibility of IOL in-the-bag implantation the ArtificialIris was placed in sulcus sutureless through a clear corneal tunnel. Maximal follow-up was 6 months. The complex device was placed firmly fixed within the sulcus, including in the eye implanted without sutures, and showed a stable and centered position without any tilt or torque. Management of post-traumatic aniridia combined with aphakia by haptic fixation of a foldable acrylic IOL on a foldable iris prosthesis appears to be a promising approach which gives the surgeon the possibility to correct a complex lesion with one procedure, which is less traumatic and faster. Existence of foldable materials, both iris and IOL, permits relatively small corneal incisions (4.0-5.0 mm). Moreover, the custom-tailored iris prosthesis gives a perfect aesthetic result.

  17. SU-F-T-650: The Comparison of Robotic Partial Breast Stereotactic Irradiation Using MLC Vs. Iris Cone

    Energy Technology Data Exchange (ETDEWEB)

    Ding, C; Timmerman, R; Jiang, S; Rahimi, A [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: To evaluate the dosimetric impact on treatment planning for partial breast stereotactic irradiation using Cyberknife with MLC versus Iris Cone. Methods: Ten patients whom underwent lumpectomy for DCIS or stage I invasive non-lobular epithelial breast cancer were included in this study. All patients were previously treated on the Cyberknife using Iris cone with the prescription dose of 37.5Gy in 5 fractions covering at least 95% of PTV on our phase I SBRT 5 fraction partial breast irradiation trial. Retrospectively, treatment planning was performed and compared using the new Cyberknife M6 MLC system for each patient. Using the same contours and critical organ constraints for both MLC and Iris cone plans, the dose on target and critical organs were analyzed accordingly. Results: Dose to critical organs such as ipsilateral lung, contralateral lung, heart, skin, ipsilateral breast, and rib were analyzed, as well as conformity index and high dose spillage of the target area. In 9 of 10 patients, the MLC plans had less total ipsilateral breast volume encompassing the 50% prescription isodose (mean:22.3±8.2% MLC vs. 31.6±8.0 Iris, p=0.00014) .The MLC plans mean estimated treatment delivery time was significantly less than the Iris plans (51±3.9min vs. 56.2±9min, p=0.03) Both MLC and Iris cone plans were able to meet all dose constraints and there was no statistical difference between those dose constraints. Conclusion: Both MLC and Iris Cone can deliver conformal dose to a partial breast target and satisfy the dose constraints of critical organs. The new Cyberknife with MLC can deliver a more conformal dose in the lower dose region and spare more ipsilateral breast tissue to the 50% prescription isodose. The treatment time for partial breast SBRT plans was also reduced using MLC. Project receives research support from Accuray Inc.

  18. Mapping of land cover in Northern California with simulated HyspIRI images

    Science.gov (United States)

    Clark, M. L.; Kilham, N. E.

    2014-12-01

    Land-cover maps are important science products needed for natural resource and ecosystem service management, biodiversity conservation planning, and assessing human-induced and natural drivers of land change. Most land-cover maps at regional to global scales are produced with remote sensing techniques applied to multispectral satellite imagery with 30-500 m pixel sizes (e.g., Landsat, MODIS). Hyperspectral, or imaging spectrometer, imagery measuring the visible to shortwave infrared regions (i.e., full range) of the spectrum have shown improved capacity to map plant species and coarser land-cover associations, yet techniques have not been widely tested at regional and greater spatial scales. The Hyperspectral Infrared Imager (HyspIRI) mission is a full-range hyperspectral and thermal satellite being considered for development by NASA (hyspiri.jpl.nasa.gov). A hyperspectral satellite, such as HyspIRI, will provide detailed spectral and temporal information at global scales that could greatly improve our ability to map land cover with greater class detail and spatial and temporal accuracy than possible with conventional multispectral satellites. The broad goal of our research is to assess multi-temporal, HyspIRI-like satellite imagery for improved land cover mapping across a range of environmental and anthropogenic gradients in California. In this study, we mapped FAO Land Cover Classification System (LCCS) classes over 30,000 km2 in Northern California using multi-temporal HyspIRI imagery simulated from the AVIRIS airborne sensor. The Random Forests classification was applied to predictor variables derived from the multi-temporal hyperspectral data and accuracies were compared to that from Landsat 8 OLI. Results indicate increased mapping accuracy using HyspIRI multi-temporal imagery, particularly in discriminating different forest life-form types, such as mixed conifer and broadleaf forests and open- and closed-canopy forests.

  19. Promoting seismology education and research via the IRIS Education and Public Outreach Program

    Science.gov (United States)

    Taber, J. J.; Bravo, T. K.; Dorr, P. M.; Hubenthal, M.; Johnson, J. A.; McQuillan, P.; Sumy, D. F.; Welti, R.

    2015-12-01

    combination of internal and external assessments, with an emphasis on formative evaluation and regular review by an advisory committee of community members. Results from our assessments inform the program's decision-making process, which has allowed IRIS to significantly enhance its EPO activities over time.

  20. Evaluation of PWR and BWR assembly benchmark calculations. Status report of EPRI computational benchmark results, performed in the framework of the Netherlands` PINK programme (Joint project of ECN, IRI, KEMA and GKN)

    Energy Technology Data Exchange (ETDEWEB)

    Gruppelaar, H. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Klippel, H.T. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Kloosterman, J.L. [Netherlands Energy Research Foundation (ECN), Petten (Netherlands); Hoogenboom, J.E. [Technische Univ. Delft (Netherlands). Interfacultair Reactor Instituut; Leege, P.F.A. de [Technische Univ. Delft (Netherlands). Interfacultair Reactor Instituut; Verhagen, F.C.M. [Keuring van Electrotechnische Materialen NV, Arnhem (Netherlands); Bruggink, J.C. [Gemeenschappelijke Kernenergiecentrale Nederland N.V., Dodewaard (Netherlands)

    1993-11-01

    Benchmark results of the Dutch PINK working group on calculational benchmarks on single pin cell and multipin assemblies as defined by EPRI are presented and evaluated. First a short update of methods used by the various institutes involved is given as well as an update of the status with respect to previous performed pin-cell calculations. Problems detected in previous pin-cell calculations are inspected more closely. Detailed discussion of results of multipin assembly calculations is given. The assembly consists of 9 pins in a multicell square lattice in which the central pin is filled differently, i.e. a Gd pin for the BWR assembly and a control rod/guide tube for the PWR assembly. The results for pin cells showed a rather good overall agreement between the four participants although BWR pins with high void fraction turned out to be difficult to calculate. With respect to burnup calculations good overall agreement for the reactivity swing was obtained, provided that a fine time grid is used. (orig.)

  1. Evaluation of PWR and BWR assembly benchmark calculations. Status report of EPRI computational benchmark results, performed in the framework of the Netherlands' PINK programme (Joint project of ECN, IRI, KEMA and GKN)

    International Nuclear Information System (INIS)

    Gruppelaar, H.; Klippel, H.T.; Kloosterman, J.L.; Hoogenboom, J.E.; Bruggink, J.C.

    1993-11-01

    Benchmark results of the Dutch PINK working group on calculational benchmarks on single pin cell and multipin assemblies as defined by EPRI are presented and evaluated. First a short update of methods used by the various institutes involved is given as well as an update of the status with respect to previous performed pin-cell calculations. Problems detected in previous pin-cell calculations are inspected more closely. Detailed discussion of results of multipin assembly calculations is given. The assembly consists of 9 pins in a multicell square lattice in which the central pin is filled differently, i.e. a Gd pin for the BWR assembly and a control rod/guide tube for the PWR assembly. The results for pin cells showed a rather good overall agreement between the four participants although BWR pins with high void fraction turned out to be difficult to calculate. With respect to burnup calculations good overall agreement for the reactivity swing was obtained, provided that a fine time grid is used. (orig.)

  2. 75 FR 76982 - Integrated Risk Information System (IRIS); Announcement of Availability of Literature Searches...

    Science.gov (United States)

    2010-12-10

    ... Information System (IRIS); Announcement of Availability of Literature Searches for IRIS Assessments AGENCY: Environmental Protection Agency. ACTION: Announcement of availability of literature searches for IRIS... the availability of literature searches for four IRIS assessments, acetaldehyde (CAS No. 75-07-0...

  3. Iridium Interfacial Stack - IrIS

    Science.gov (United States)

    Spry, David

    2012-01-01

    Iridium Interfacial Stack (IrIS) is the sputter deposition of high-purity tantalum silicide (TaSi2-400 nm)/platinum (Pt-200 nm)/iridium (Ir-200 nm)/platinum (Pt-200 nm) in an ultra-high vacuum system followed by a 600 C anneal in nitrogen for 30 minutes. IrIS simultaneously acts as both a bond metal and a diffusion barrier. This bondable metallization that also acts as a diffusion barrier can prevent oxygen from air and gold from the wire-bond from infiltrating silicon carbide (SiC) monolithically integrated circuits (ICs) operating above 500 C in air for over 1,000 hours. This TaSi2/Pt/Ir/Pt metallization is easily bonded for electrical connection to off-chip circuitry and does not require extra anneals or masking steps. There are two ways that IrIS can be used in SiC ICs for applications above 500 C: it can be put directly on a SiC ohmic contact metal, such as Ti, or be used as a bond metal residing on top of an interconnect metal. For simplicity, only the use as a bond metal is discussed. The layer thickness ratio of TaSi2 to the first Pt layer deposited thereon should be 2:1. This will allow Si from the TaSi2 to react with the Pt to form Pt2Si during the 600 C anneal carried out after all layers have been deposited. The Ir layer does not readily form a silicide at 600 C, and thereby prevents the Si from migrating into the top-most Pt layer during future anneals and high-temperature IC operation. The second (i.e., top-most) deposited Pt layer needs to be about 200 nm to enable easy wire bonding. The thickness of 200 nm for Ir was chosen for initial experiments; further optimization of the Ir layer thickness may be possible via further experimentation. Ir itself is not easily wire-bonded because of its hardness and much higher melting point than Pt. Below the iridium layer, the TaSi2 and Pt react and form desired Pt2Si during the post-deposition anneal while above the iridium layer remains pure Pt as desired to facilitate easy and strong wire-bonding to the Si

  4. Scale Invariant Gabor Descriptor-Based Noncooperative Iris Recognition

    Directory of Open Access Journals (Sweden)

    Du Yingzi

    2010-01-01

    Full Text Available Abstract A new noncooperative iris recognition method is proposed. In this method, the iris features are extracted using a Gabor descriptor. The feature extraction and comparison are scale, deformation, rotation, and contrast-invariant. It works with off-angle and low-resolution iris images. The Gabor wavelet is incorporated with scale-invariant feature transformation (SIFT for feature extraction to better extract the iris features. Both the phase and magnitude of the Gabor wavelet outputs were used in a novel way for local feature point description. Two feature region maps were designed to locally and globally register the feature points and each subregion in the map is locally adjusted to the dilation/contraction/deformation. We also developed a video-based non-cooperative iris recognition system by integrating video-based non-cooperative segmentation, segmentation evaluation, and score fusion units. The proposed method shows good performance for frontal and off-angle iris matching. Video-based recognition methods can improve non-cooperative iris recognition accuracy.

  5. Scale Invariant Gabor Descriptor-based Noncooperative Iris Recognition

    Directory of Open Access Journals (Sweden)

    Zhi Zhou

    2010-01-01

    Full Text Available A new noncooperative iris recognition method is proposed. In this method, the iris features are extracted using a Gabor descriptor. The feature extraction and comparison are scale, deformation, rotation, and contrast-invariant. It works with off-angle and low-resolution iris images. The Gabor wavelet is incorporated with scale-invariant feature transformation (SIFT for feature extraction to better extract the iris features. Both the phase and magnitude of the Gabor wavelet outputs were used in a novel way for local feature point description. Two feature region maps were designed to locally and globally register the feature points and each subregion in the map is locally adjusted to the dilation/contraction/deformation. We also developed a video-based non-cooperative iris recognition system by integrating video-based non-cooperative segmentation, segmentation evaluation, and score fusion units. The proposed method shows good performance for frontal and off-angle iris matching. Video-based recognition methods can improve non-cooperative iris recognition accuracy.

  6. Enhancement of Iris Recognition System Based on Phase Only Correlation

    Directory of Open Access Journals (Sweden)

    Nuriza Pramita

    2011-08-01

    Full Text Available Iris recognition system is one of biometric based recognition/identification systems. Numerous techniques have been implemented to achieve a good recognition rate, including the ones based on Phase Only Correlation (POC. Significant and higher correlation peaks suggest that the system recognizes iris images of the same subject (person, while lower and unsignificant peaks correspond to recognition of those of difference subjects. Current POC methods have not investigated minimum iris point that can be used to achieve higher correlation peaks. This paper proposed a method that used only one-fourth of full normalized iris size to achieve higher (or at least the same recognition rate. Simulation on CASIA version 1.0 iris image database showed that averaged recognition rate of the proposed method achieved 67%, higher than that of using one-half (56% and full (53% iris point. Furthermore, all (100% POC peak values of the proposed method was higher than that of the method with full iris points.

  7. Cross-sensor iris recognition through kernel learning.

    Science.gov (United States)

    Pillai, Jaishanker K; Puertas, Maria; Chellappa, Rama

    2014-01-01

    Due to the increasing popularity of iris biometrics, new sensors are being developed for acquiring iris images and existing ones are being continuously upgraded. Re-enrolling users every time a new sensor is deployed is expensive and time-consuming, especially in applications with a large number of enrolled users. However, recent studies show that cross-sensor matching, where the test samples are verified using data enrolled with a different sensor, often lead to reduced performance. In this paper, we propose a machine learning technique to mitigate the cross-sensor performance degradation by adapting the iris samples from one sensor to another. We first present a novel optimization framework for learning transformations on iris biometrics. We then utilize this framework for sensor adaptation, by reducing the distance between samples of the same class, and increasing it between samples of different classes, irrespective of the sensors acquiring them. Extensive evaluations on iris data from multiple sensors demonstrate that the proposed method leads to improvement in cross-sensor recognition accuracy. Furthermore, since the proposed technique requires minimal changes to the iris recognition pipeline, it can easily be incorporated into existing iris recognition systems.

  8. Iris segmentation using an edge detector based on fuzzy sets theory and cellular learning automata.

    Science.gov (United States)

    Ghanizadeh, Afshin; Abarghouei, Amir Atapour; Sinaie, Saman; Saad, Puteh; Shamsuddin, Siti Mariyam

    2011-07-01

    Iris-based biometric systems identify individuals based on the characteristics of their iris, since they are proven to remain unique for a long time. An iris recognition system includes four phases, the most important of which is preprocessing in which the iris segmentation is performed. The accuracy of an iris biometric system critically depends on the segmentation system. In this paper, an iris segmentation system using edge detection techniques and Hough transforms is presented. The newly proposed edge detection system enhances the performance of the segmentation in a way that it performs much more efficiently than the other conventional iris segmentation methods.

  9. Nonintrusive iris image acquisition system based on a pan-tilt-zoom camera and light stripe projection

    Science.gov (United States)

    Yoon, Soweon; Jung, Ho Gi; Park, Kang Ryoung; Kim, Jaihie

    2009-03-01

    Although iris recognition is one of the most accurate biometric technologies, it has not yet been widely used in practical applications. This is mainly due to user inconvenience during the image acquisition phase. Specifically, users try to adjust their eye position within small capture volume at a close distance from the system. To overcome these problems, we propose a novel iris image acquisition system that provides users with unconstrained environments: a large operating range, enabling movement from standing posture, and capturing good-quality iris images in an acceptable time. The proposed system has the following three contributions compared with previous works: (1) the capture volume is significantly increased by using a pan-tilt-zoom (PTZ) camera guided by a light stripe projection, (2) the iris location in the large capture volume is found fast due to 1-D vertical face searching from the user's horizontal position obtained by the light stripe projection, and (3) zooming and focusing on the user's irises at a distance are accurate and fast using the estimated 3-D position of a face by the light stripe projection and the PTZ camera. Experimental results show that the proposed system can capture good-quality iris images in 2.479 s on average at a distance of 1.5 to 3 m, while allowing a limited amount of movement by the user.

  10. Development of a coupled containment-reactor coolant system methodology for the analysis of IRIS small break LOCA

    International Nuclear Information System (INIS)

    Manfredini, Antonio; Oriolo, Francesco; Paci, Sandro; Oriani, Luca

    2003-01-01

    The main purpose of the present work is to identify the most relevant physical phenomena for the IRIS (International Reactor Innovative and Secure) containment system and the development of an integrated methodology for the simultaneous safety analysis of both the reactor and containment with available computer codes. Specific objectives are: (a) to assess the limitations of the lumped parameter codes on predictions of complex situations; (b) to identify alternatives to classical containment analysis techniques. The characteristic features of an integral reactor like IRIS present a much greater challenge to code developers than conventional, loop type PWRs. In particular, the integral primary system and the containment are strongly coupled during postulated accident conditions and thus an integrated simulation of both systems is required to obtain a reliable phenomenological representation. The comparison of the results obtained in the application of two containment codes (GOTHIC and integrated FUMO) on 'ad hoc' IRIS related benchmarks will also be described. These preliminary calculations were used to test the IRIS containment concept and cooling strategies, at the same time highlighting the most relevant issues that require a more refined investigation. Finally, this activity allowed to perform more refined calculations, in progress at the moment, aimed at showing that the IRIS safety systems and containment design solutions perform their intended functions. (author)

  11. IRIS: A SIGNIFICANT ELEMENT OF THE MEDITERRANEAN LANDSCAPE

    Directory of Open Access Journals (Sweden)

    A. UBRIZSY SAVOIA

    2000-01-01

    Full Text Available The Southern European species of Iris growing in dry, rocky places, stony ground, terra rossa, sandy, basalt and/or calcareous hills, maquis and coastal rocky slopes, are a neglected bioplasm resource of the Mediterranean landscape. These species have traditional uses and cultural significance and have inspired artists. Both natural and naturalised ornamental Iris species may help to improve and maintain the Mediterranean landscape by avoiding land erosion, fixing dunes and preserving coastal zones. These Iris species are a significant component of Mediterranean floristic diversity. Their conservation and use in traditional Mediterranean landscape gardening are emphasised.

  12. IRIS: A SIGNIFICANT ELEMENT OF THE MEDITERRANEAN LANDSCAPE

    Directory of Open Access Journals (Sweden)

    S. PIGNATTI

    2000-04-01

    Full Text Available The Southern European species of Iris growing in dry, rocky places, stony ground, terra rossa, sandy, basalt and/or calcareous hills, maquis and coastal rocky slopes, are a neglected bioplasm resource of the Mediterranean landscape. These species have traditional uses and cultural significance and have inspired artists. Both natural and naturalised ornamental Iris species may help to improve and maintain the Mediterranean landscape by avoiding land erosion, fixing dunes and preserving coastal zones. These Iris species are a significant component of Mediterranean floristic diversity. Their conservation and use in traditional Mediterranean landscape gardening are emphasised.

  13. Some measurement possibilities for the improvement of IRI

    International Nuclear Information System (INIS)

    Serafimov, K.B.

    1984-01-01

    Some methodological assumptions behind the development of improved measurements for use in the International Reference Ionosphere (IRI) are presented. Attention is given to improving the IRI-representation of electron density in the D-region by comparing data from vertical rocket soundings and absorption measurements on multifrequencies ionosondes; by the application of absorption measurements for the specification of density profile structure; and by the use of combined rocket and ground-based measurements. The methodological possibilities, for improving the IRI-distribution of electron densities in the bottomside and topside ionosphere, and for the specification of Te(h) profiles are also discussed

  14. BRCA1-IRIS Overexpression Promotes Formation of Aggressive Breast Cancers

    Science.gov (United States)

    Shimizu, Yoshiko; Luk, Hugh; Horio, David; Miron, Penelope; Griswold, Michael; Iglehart, Dirk; Hernandez, Brenda; Killeen, Jeffrey; ElShamy, Wael M.

    2012-01-01

    Introduction Women with HER2+ or triple negative/basal-like (TN/BL) breast cancers succumb to their cancer rapidly due, in part to acquired Herceptin resistance and lack of TN/BL-targeted therapies. BRCA1-IRIS is a recently discovered, 1399 residue, BRCA1 locus alternative product, which while sharing 1365 residues with the full-length product of this tumor suppressor gene, BRCA1/p220, it has oncoprotein-like properties. Here, we examine whether BRCA1-IRIS is a valuable treatment target for HER2+ and/or TN/BL tumors. Methodology/Principal Findings Immunohistochemical staining of large cohort of human breast tumor samples using new monoclonal anti-BRCA1-IRIS antibody, followed by correlation of BRCA1-IRIS expression with that of AKT1, AKT2, p-AKT, survivin and BRCA1/p220, tumor status and age at diagnosis. Generation of subcutaneous tumors in SCID mice using human mammary epithelial (HME) cells overexpressing TERT/LT/BRCA1-IRIS, followed by comparing AKT, survivin, and BRCA1/p220 expression, tumor status and aggressiveness in these tumors to that in tumors developed using TERT/LT/RasV12-overexpressing HME cells. Induction of primary and invasive rat mammary tumors using the carcinogen N-methyl-N-nitrosourea (NMU), followed by analysis of rat BRCA1-IRIS and ERα mRNA levels in these tumors. High BRCA1-IRIS expression was detected in the majority of human breast tumors analyzed, which was positively correlated with that of AKT1-, AKT2-, p-AKT-, survivin, but negatively with BRCA1/p220 expression. BRCA1-IRIS-positivity induced high-grade, early onset and metastatic HER2+ or TN/BL tumors. TERT/LT/BRCA1-IRIS overexpressing HME cells formed invasive subcutaneous tumors that express high AKT1, AKT2, p-AKT and vimentin, but no CK19, p63 or BRCA1/p220. NMU-induced primary and invasive rat breast cancers expressed high levels of rat BRCA1-IRIS mRNA but low levels of rat ERα mRNA. Conclusion/Significance BRCA1-IRIS overexpression triggers aggressive breast tumor formation

  15. Challenges at different stages of an iris based biometric system

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Singla

    2012-04-01

    Full Text Available Iris recognition has been used for authentication for the past few years and is capable of positive/negative authenticationof an individual without any physical contact or intervention. This technique is being used mainly because of its uniqueness,stability, and reliability but still many challenges are being faced an the iris based recognition system. This paperpresents the difficulties faced in different modules, like the sensor module, preprocessing module, feature extraction module,and matching module of an iris biometric system.

  16. Keskittymishäiriön kuvaaminen syanotypialla

    OpenAIRE

    Lammela, Maarit

    2017-01-01

    Toiminallisessa opinnäytetyössäni oli tavoitteena havainnollistaa kuvina luki- ja keskittymishäiriön tunnetiloja syanotypialla vedostaen. Projektissa tarkastelin ja tutkin itseäni. Havainnollistin kuvina yli viisikymmentä luonteenpiirrettä, jotka ovat tyypillisiä luki- ja keskittymishäiriöiselle ihmiselle. Näistä toteutin teoksiksi 25. Kuvasin itseäni ja tunnetilojani digikameralla itselaukaisinta apuna käyttäen. Halusin tehdä tämän työn kertoakseni luki- ja keskittymishäiriöisen ihmisen t...

  17. Activity of MM-398, nanoliposomal irinotecan (nal-IRI), in Ewing's family tumor xenografts is associated with high exposure of tumor to drug and high SLFN11 expression.

    Science.gov (United States)

    Kang, Min H; Wang, Jing; Makena, Monish R; Lee, Joo-Sang; Paz, Nancy; Hall, Connor P; Song, Michael M; Calderon, Ruben I; Cruz, Riza E; Hindle, Ashly; Ko, Winford; Fitzgerald, Jonathan B; Drummond, Daryl C; Triche, Timothy J; Reynolds, C Patrick

    2015-03-01

    To determine the pharmacokinetics and the antitumor activity in pediatric cancer models of MM-398, a nanoliposomal irinotecan (nal-IRI). Mouse plasma and tissue pharmacokinetics of nal-IRI and the current clinical formulation of irinotecan were characterized. In vivo activity of irinotecan and nal-IRI was compared in xenograft models (3 each in nu/nu mice) of Ewing's sarcoma family of tumors (EFT), neuroblastoma (NB), and rhabdomyosarcoma (RMS). SLFN11 expression was assessed by Affymetrix HuEx arrays, Taqman RT-PCR, and immunoblotting. Plasma and tumor concentrations of irinotecan and SN-38 (active metabolite) were approximately 10-fold higher for nal-IRI than for irinotecan. Two doses of NAL-IRI (10 mg/kg/dose) achieved complete responses maintained for >100 days in 24 of 27 EFT-xenografted mice. Event-free survival for mice with RMS and NB was significantly shorter than for EFT. High SLFN11 expression has been reported to correlate with sensitivity to DNA damaging agents; median SLFN11 mRNA expression was >100-fold greater in both EFT cell lines and primary tumors compared with NB or RMS cell lines or primary tumors. Cytotoxicity of SN-38 inversely correlated with SLFN11 mRNA expression in 20 EFT cell lines. In pediatric solid tumor xenografts, nal-IRI demonstrated higher systemic and tumor exposures to SN-38 and improved antitumor activity compared with the current clinical formulation of irinotecan. Clinical studies of nal-IRI in pediatric solid tumors (especially EFT) and correlative studies to determine if SLFN11 expression can serve as a biomarker to predict nal-IRI clinical activity are warranted. ©2015 American Association for Cancer Research.

  18. Machine learning techniques for medical diagnosis of diabetes using iris images.

    Science.gov (United States)

    Samant, Piyush; Agarwal, Ravinder

    2018-04-01

    Complementary and alternative medicine techniques have shown their potential for the treatment and diagnosis of chronical diseases like diabetes, arthritis etc. On the same time digital image processing techniques for disease diagnosis is reliable and fastest growing field in biomedical. Proposed model is an attempt to evaluate diagnostic validity of an old complementary and alternative medicine technique, iridology for diagnosis of type-2 diabetes using soft computing methods. Investigation was performed over a close group of total 338 subjects (180 diabetic and 158 non-diabetic). Infra-red images of both the eyes were captured simultaneously. The region of interest from the iris image was cropped as zone corresponds to the position of pancreas organ according to the iridology chart. Statistical, texture and discrete wavelength transformation features were extracted from the region of interest. The results show best classification accuracy of 89.63% calculated from RF classifier. Maximum specificity and sensitivity were absorbed as 0.9687 and 0.988, respectively. Results have revealed the effectiveness and diagnostic significance of proposed model for non-invasive and automatic diabetes diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. The uncertainty analysis of model results a practical guide

    CERN Document Server

    Hofer, Eduard

    2018-01-01

    This book is a practical guide to the uncertainty analysis of computer model applications. Used in many areas, such as engineering, ecology and economics, computer models are subject to various uncertainties at the level of model formulations, parameter values and input data. Naturally, it would be advantageous to know the combined effect of these uncertainties on the model results as well as whether the state of knowledge should be improved in order to reduce the uncertainty of the results most effectively. The book supports decision-makers, model developers and users in their argumentation for an uncertainty analysis and assists them in the interpretation of the analysis results.

  20. Peer Review Comments on the IRIS Assessment of Benzene

    Science.gov (United States)

    Attachment to IRIS file for benzene, January 19, 2000, RESPONSE TO THE PEER REVIEW COMMENTS, II. Extrapolation of the Benzene Inhalation Unit Risk Estimate to the Oral Route of Exposure (EPA/NCEA-W-0517, July 1999)

  1. IRIS Toxicological Review of Hexavalent Chromium (Peer Review Plan)

    Science.gov (United States)

    EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of hexavalent chromium that will appear on the Integrated Risk Information System (IRIS) database.

  2. an enhanced iris recognition and authentication system using ...

    African Journals Online (AJOL)

    Biu et al.

    1Department of Mathematical Sciences, Kaduna State University, Kaduna – Nigeria. (E-mail: ..... localization, the iris is in a circulation fashion then lastly, the image is saved into .... Conference on Computer Engineering Systems. Cleve, K.

  3. IRIS Toxicological Review of Trichloroacetic Acid (TCA) (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroacetic acid (TCA) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

  4. IRIS Toxicological Review of Trichloroacetic Acid (Tca) (Final Report)

    Science.gov (United States)

    EPA has finalized the Toxicological Review of Trichloroacetic Acid: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health.

  5. IRIS Toxicological Review of Trichloroethylene (Interagency Science Discussion Draft)

    Science.gov (United States)

    EPA is releasing the draft report, Toxicological Review of Trichloroethylene, that was distributed to Federal agencies and White House Offices for comment during the Science Discussion step of the IRIS Assessment Development Process. Comments received from other Federal agencies ...

  6. IRIS Toxicological Review of Trichloroethylene (TCE) (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Trichloroethylene (TCE) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

  7. IRIS Toxicological Review of Hydrogen Cyanide (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review of the scientific basis supporting the human health hazard and dose-response assessment of hydrogen cyanide and cyanide salts that will appear on the Integrated Risk Information System (IRIS) database.

  8. Bilateral acute iris transillumination (BAIT initially misdiagnosed as acute iridocyclitis

    Directory of Open Access Journals (Sweden)

    Saban Gonul

    2015-04-01

    Full Text Available Bilateral acute iris transillumination (BAIT is a relatively new clinical entity characterized by bilateral acute loss of iris pigment epithelium, iris transillumination, pigment dispersion in the anterior chamber, and sphincter paralysis. We report the case of a 30-year-old male who was initially diagnosed with acute iridocyclitis in a different clinic and treated with topical and systemic corticosteroids. He was referred to our clinic to seek another opinion because his symptoms did not improve. An ocular examination revealed bilateral pigment dispersion into the anterior chamber, diffuse iris transillumination, pigment dusting on the anterior lens capsule, atonic and distorted pupils, and increased intraocular pressure, suggesting a diagnosis of BAIT rather than iridocyclitis. Clinicians should be aware of the differential diagnosis of syndromes associated with pigment dispersion from iridocyclitis to avoid aggressive anti-inflammatory therapy and detailed investigation for uveitis.

  9. IRIS Toxicological Review of Tetrahydrofuran (THF) (External Review Draft)

    Science.gov (United States)

    EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of tetrahydrofuran (THF) that when finalized will appear on the Integrated Risk Information System (IRIS) database.

  10. IRIS Toxicological Review of Methanol (Noncancer) (Final Report)

    Science.gov (United States)

    EPA conducted a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of Methanol (noncancer) , this is finalized and posted on the IRIS Web site.

  11. IRIS Toxicological Review of Tetrahydrofuran (THF) (Final Report)

    Science.gov (United States)

    EPA has released the Toxicological Review of Tetrahydrofuran: in support of the Integrated Risk Information System (IRIS). Now final, this assessment may be used by EPA’s program and regional offices to inform decisions to protect human health.

  12. Embedded Design Research of Iris Information Acquisition System

    Directory of Open Access Journals (Sweden)

    Huiyan Xu

    2014-09-01

    Full Text Available In view of the limitation of traditional identification, it is easy to lose and copy keys, cards or ID cards, and it is easy to forget the password, so we designed an embedded application system based on the iris identification technology, which can realize the functions of gathering, inputting, and registering the iris information and identification. The hardware circuit was designed by using advanced RISC machines (ARM embedded microprocessor as the core. The iris sensor was used to gather the iris information, and the development of software was accomplished with the embedded OS Windows CE. The system can be used on the company entrance guard system, customs security of airport and criminal identification.

  13. A bibliography of IRIS-related publications, 2000-2011

    Science.gov (United States)

    Muco, B.

    2012-12-01

    Citations and acknowledgements in scientific journals can be an indicator of the role an organization has on the research of that field. Since its formation and incorporation in May 1984, the IRIS Consortium (Incorporated Research Institutions for Seismology) is mentioned more and more as a valuable source of data, instruments and programs in the literature of earth sciences. As a large organization with more than 100 member domestic institutes and about 40 international affiliates, obviously IRIS has a direct impact on the earth sciences through all its programs, projects, workshops, symposia, and news¬letters and as a lively forum for exchanging ideas. In order to maintain support from National Science Foundation (NSF) and the research community, it is important to document the continued use of IRIS facilities in basic research programs. IRIS maintains a database of articles that are based on the use of IRIS facilities or which reference use of IRIS data and resources. Articles in this database have been either been provided to IRIS by the authors or selected through an annual search of a number of prominent journals. A text version of the full bibliographic database is available on the IRIS website and a version in EndNote format is also provided. To provide a more complete bibliography and a consistent evaluation of temporal tends in publications, a special annual search began in 2000 which focused on a subset of key seismology and Earth science journals: Bulletin of Seismological Society of America, Journal of Geophysical Research, Seismological Research Letters, Geophysical Research Letters, Earth and Planetary Science Letters, Physics of the Earth and Planetary Interiors, Tectonophysics, Geophysical Journal International, Nature, Science, Geology and EOS. Using different search engines as Scirus, ScienceDirect, GeoRef, OCLC First Search, EASI Search, NASA Abstract Service etc. for online journals and publishers' databases, we searched for key words (IRIS

  14. Retinal vascular caliber, iris color, and age-related macular degeneration in the Irish Nun Eye Study.

    Science.gov (United States)

    McGowan, Amy; Silvestri, Giuliana; Moore, Evelyn; Silvestri, Vittorio; Patterson, Christopher C; Maxwell, Alexander P; McKay, Gareth J

    2014-12-18

    To evaluate the relationship between retinal vascular caliber (RVC), iris color, and age-related macular degeneration (AMD) in elderly Irish nuns. Data from 1233 participants in the cross-sectional observational Irish Nun Eye Study were assessed from digital photographs with a standardized protocol using computer-assisted software. Macular images were graded according to the modified Wisconsin Age-related Maculopathy Grading System. Regression models were used to assess associations, adjusting for age, mean arterial blood pressure, body mass index, refraction, and fellow RVC. In total, 1122 (91%) participants had gradable retinal images of sufficient quality for vessel assessment (mean age: 76.3 years [range, 56-100 years]). In an unadjusted analysis, we found some support for a previous finding that individuals with blue iris color had narrower retinal venules compared to those with brown iris color (P < 0.05), but this was no longer significant after adjustment. Age-related macular degeneration status was categorized as no AMD, any AMD, and late AMD only. Individuals with any AMD (early or late AMD) had significantly narrower arterioles and venules compared to those with no AMD in an unadjusted analysis, but this was no longer significant after adjustment. A nonsignificant reduced risk of any AMD or late AMD only was observed in association with brown compared to blue iris color, in both unadjusted and adjusted analyses. Retinal vascular caliber was not significantly associated with iris color or early/late AMD after adjustment for confounders. A lower but nonsignificant AMD risk was observed in those with brown compared to blue iris color. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  15. V and V Efforts of Auroral Precipitation Models: Preliminary Results

    Science.gov (United States)

    Zheng, Yihua; Kuznetsova, Masha; Rastaetter, Lutz; Hesse, Michael

    2011-01-01

    Auroral precipitation models have been valuable both in terms of space weather applications and space science research. Yet very limited testing has been performed regarding model performance. A variety of auroral models are available, including empirical models that are parameterized by geomagnetic indices or upstream solar wind conditions, now casting models that are based on satellite observations, or those derived from physics-based, coupled global models. In this presentation, we will show our preliminary results regarding V&V efforts of some of the models.

  16. IRIS: A SIGNIFICANT ELEMENT OF THE MEDITERRANEAN LANDSCAPE

    OpenAIRE

    A. UBRIZSY SAVOIA; S. PIGNATTI; S. VAROLI PIAZZA

    2000-01-01

    The Southern European species of Iris growing in dry, rocky places, stony ground, terra rossa, sandy, basalt and/or calcareous hills, maquis and coastal rocky slopes, are a neglected bioplasm resource of the Mediterranean landscape. These species have traditional uses and cultural significance and have inspired artists. Both natural and naturalised ornamental Iris species may help to improve and maintain the Mediterranean landscape by avoiding land erosion, fixing dunes and preserving coastal...

  17. IRIS: A global approach to nuclear power renaissance

    International Nuclear Information System (INIS)

    Carelli, M.D.

    2004-01-01

    Improved international reactor IRIS (International Reactor Innovative and Secure) is discussed. IRIS is defined as a modular reactor with integral arrangement and water coolant. Design of reactor core and fuel elements is considered. Use of radial neutron reflectors from stainless steel is favorable to decrease of cost and increase of reactor operation. Reactor maintenance, constructional safety and arrangement of plant are characterized. Economical analysis and marketing are performed [ru

  18. Comparison of electron density profiles observed in China's low latitude station with that produced by the International Reference Ionosphere (IRI2001)

    International Nuclear Information System (INIS)

    Zhang Manlian; Shi Jiankui; Wang Xiao

    2003-01-01

    One month's data of ionograms observed by DPS-4 digisonde in China's low latitude station Hainan (19.4 deg N/109.0 deg E) for the high solar activity year 2002 is used to make a comparison study between the observational electron density profiles and that produced by the newly updated International Reference Ionosphere (IRI2001). The present study showed that for the month studied (April, 2002): (1) When B0-Tab value is used, profiles given by IRI2001 are in poor agreement with the observational results during daytime and nearby midnight hours when standard Ne(h) option is chosen, whereas when the LAY functions version is chosen, IRI2001 produces profiles with erroneous features during evening and nighttime hours, although it produces profiles in a reasonable good agreement with the observational ones during daytime hours. (2) In general, profiles produced by IRI2001 with B0-Gulyaeva choice is in better agreement with observational profiles than when B0-Tab is chosen. When the B0-Gulyaeva and LAY functions version of Ne(h) are both chosen, IRI2001 produced the best results when compared with the observational results. (3) The B0 parameter given by B0-Gulyaeva choice in IRI2001 is much closer to the observed (best fitted) one than that given by the B0-Tab choice is. (author)

  19. Variation of hmF2 and NmF2 deduced from DPS-4 over Multan (Pakistan) and their comparisons with IRI-2012 & IRI-2016 during the deep solar minimum between cycles 23 & 24

    Science.gov (United States)

    Ameen, Muhammad Ayyaz; Khursheed, Haqqa; Jabbar, Mehak Abdul; Ali, Muneeza Salman; Chishtie, Farrukh

    2018-04-01

    We report the results of ionospheric measurements from DPS-4 installed at Multan (Geog coord. 30.18°N, 71.48°E, dip 47.4°). The variations in F2-layer maximum electron density NmF2 and its peak height hmF2 are studied during the deep solar minimum between cycles 23 & 24 i.e 2008-2009 with comparisons conducted with the International Reference Ionosphere (IRI) versions 2012 & 2016. We find that the hmF2 observations peak around the pre-sunrise and sunrise hours depending on the month. Seasonally, the daytime variation of NmF2 is higher in the Equinox and Summer, while daytime hmF2 are slightly higher in the Equinox and Winter. High values of hmF2 around midnight are caused by an increase of upward drifts produced by meridional winds. The ionosphere over Multan, which lies at the verge of low and mid latitude, is affected by both E × B drifts and thermospheric winds as evident from mid-night peaks and near-sunrise dips in hmF2. The results of the comparison of the observed NmF2 and hmF2 for the year 2008-2009 with the IRI-2012 (both NmF2 and hmF2) and IRI-2016 (only hmF2) estimates indicate that for NmF2, IRI-2012 with Consultative Committee International Radio (CCIR) option produces values in better agreement with observed data. Whereas, for hmF2, IRI-2016 with both International Union of Radio Science (URSI) and CCIR SHU-2015 options, predicts well for nighttime hours throughout the year. However, the IRI-2012 with CCIR option produces better agreement with data during daytime hours. Furthermore, IRI-2012 with CCIR option gives better results during Equinox months, whereas, IRI-2016 with both URSI and CCIR SHU-2015 options predict well for Winter and Summer.

  20. Testing Danegaptide Effects on Kidney Function after Ischemia/Reperfusion Injury in a New Porcine Two Week Model.

    Directory of Open Access Journals (Sweden)

    Chris Amdisen

    Full Text Available Ischemia/reperfusion injury (I/R-I is a leading cause of acute kidney injury (AKI and is associated with increased mortality. Danegaptide is a selective modifier of the gap junction protein connexion 43. It has cytoprotective as well as anti-arrhythmic properties and has been shown to reduce the size of myocardial infarct in pigs. The aim of this study was to investigate the ischemia-protective effect of Danegaptide in a porcine renal I/R-I model with two weeks follow up.Unilateral renal I/R-I was induced in pigs by clamping the left renal artery over a two hour period. The model allowed examination of renal blood flow by magnetic resonance imaging (MRI and the measurement of single kidney GFR two weeks after injury. Eleven animals were randomized to Danegaptide-infusion while nine animals received placebo. Kidney histology and urinary neutrophil gelatinase-associated lipocalin (NGAL excretion were included as markers of AKI.Unilateral kidney I/R-I resulted in an immediate ~50% GFR reduction, associated with a four-fold increase in urinary NGAL-excretion. Fourteen days after I/R-I, the total GFR was ~75% of baseline with a significantly lower GFR in the injured left kidney compared to the right kidney. No differences in GFR were observed between the treated and non-treated animals immediately after I/R-I or at Day 14. Furthermore, no differences were observed in the urinary excretion of NGAL, renal blood flow or other markers of renal function.As expected this porcine renal I/R-I model was associated with reduced GFR two weeks after injury. Danegaptide did not improve renal function after I/R-I.