Slope excavation quality assessment and excavated volume calculation in hydraulic projects based on laser scanning technology

Directory of Open Access Journals (Sweden)

Chao Hu

2015-04-01

Full Text Available Slope excavation is one of the most crucial steps in the construction of a hydraulic project. Excavation project quality assessment and excavated volume calculation are critical in construction management. The positioning of excavation projects using traditional instruments is inefficient and may cause error. To improve the efficiency and precision of calculation and assessment, three-dimensional laser scanning technology was used for slope excavation quality assessment. An efficient data acquisition, processing, and management workflow was presented in this study. Based on the quality control indices, including the average gradient, slope toe elevation, and overbreak and underbreak, cross-sectional quality assessment and holistic quality assessment methods were proposed to assess the slope excavation quality with laser-scanned data. An algorithm was also presented to calculate the excavated volume with laser-scanned data. A field application and a laboratory experiment were carried out to verify the feasibility of these methods for excavation quality assessment and excavated volume calculation. The results show that the quality assessment indices can be obtained rapidly and accurately with design parameters and scanned data, and the results of holistic quality assessment are consistent with those of cross-sectional quality assessment. In addition, the time consumption in excavation quality assessment with the laser scanning technology can be reduced by 70%–90%, as compared with the traditional method. The excavated volume calculated with the scanned data only slightly differs from measured data, demonstrating the applicability of the excavated volume calculation method presented in this study.

Design of earth slide prevention structure and results of analyzing its behavior in excavation work for main building foundation for No.4 plant in Kashiwazaki-Kariwa Nuclear Power Station

International Nuclear Information System (INIS)

Kuroda, Teruo; Shimazu, Masaomi; Terada, Kenji

1990-01-01

In the construction works for No.4 plant in Kashiwazaki-Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc., the excavation work using ground anchor type earth slide prevention structure of about 30 m height intended for soft rocks was carried out. In this report, the outline of the design of the earth slide prevention structure is described, and based on the results of measurement of the earth slide prevention structure and surrounding ground during the period of the excavation work, the effect that the underground continuous wall normally intersecting with the back of the earth slide prevention wall and structurally separated from it exerted to the deformation behavior of the earth slide prevention wall was examined, and the results are reported. The geological features of the site are explained. The excavation work is to excavate the site of +5 m level down to -26 m for the turbine building and to -38.15 m for the reactor building, and the quantity of earth to be excavated is 1.39 million m 3 . These valuable experiences are utilized for the design and construction of the following plants. (K.I.)

Safety excavation; Seguranca em escavacoes

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Walter Manoel [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

2003-07-01

In the construction and maintenance services of buried pipelines, the excavation is the activity that contains larger risk, could cause serious accidents. Norms, procedures and technical articles, national and international goods, should be followed for legal and technical aspects. This paper - Safety in Excavations - has purpose to gather all the technical concepts and of safety in a document denominated Procedure of Safety Excavation, serving as instrument to systematize and control the execution of excavation services in construction civil, assembly and pipelines repairs, seeking the people, facilities and the environment's safety. (author)

Effects of demographic structure on key properties of stochastic density-independent population dynamics.

Science.gov (United States)

Vindenes, Yngvild; Sæther, Bernt-Erik; Engen, Steinar

2012-12-01

The development of stochastic demography has largely been based on age structured populations, although other types of demographic structure, especially permanent and dynamic heterogeneity, are likely common in natural populations. The combination of stochasticity and demographic structure is a challenge for analyses of population dynamics and extinction risk, because the population structure will fluctuate around the stable structure and the population size shows transient fluctuations. However, by using a diffusion approximation for the total reproductive value, density-independent dynamics of structured populations can be described with only three population parameters: the expected population growth rate, the environmental variance and the demographic variance. These parameters depend on population structure via the state-specific vital rates and transition rates. Once they are found, the diffusion approximation represents a substantial reduction in model complexity. Here, we review and compare the key population parameters across a wide range of demographic structure, from the case of no structure to the most general case of dynamic heterogeneity, and for both discrete and continuous types. We focus on the demographic variance, but also show how environmental stochasticity can be included. This study brings together results from recent models, each considering a specific type of population structure, and places them in a general framework for structured populations. Comparison across different types of demographic structure reveals that the reproductive value is an essential concept for understanding how population structure affects stochastic dynamics and extinction risk. Copyright © 2011 Elsevier Inc. All rights reserved.

Stochastic Analysis of Offshore Steel Structures An Analytical Appraisal

CERN Document Server

Karadeniz, Halil

2013-01-01

Stochastic Analysis of Offshore Steel Structures provides a clear and detailed guide to advanced analysis methods of fixed offshore steel structures using 3D beam finite elements under random wave and earthquake loadings. Advanced and up-to-date research results are coupled with modern analysis methods and essential theoretical information to consider optimal solutions to structural issues. As these methods require and use knowledge of different subject matters, a general introduction to the key areas is provided. This is followed by in-depth explanations supported by design examples, relevant calculations and supplementary material containing related computer programmers. By combining this theoretical and practical approach Stochastic Analysis of Offshore Steel Structures cover a range of key concepts in detail including: ·         The basic principles of standard 3D beam finite elements and special connections, ·         Wave loading - from hydrodynamics to the calculation of wave load...

A remotely operated excavator [HAZ-TRAK

International Nuclear Information System (INIS)

Anon.

1992-01-01

HAZ-TRAK is a remotely operated excavator and material handling system for nuclear waste site characterization, waste site remediation, and the decommissioning of nuclear facilities. HAZ-TRAK combines the power and mobility of a commercial excavator, with the dexterity and controllability of a force feedback manipulator system: when operating HAZ-TRAK as an excavator, the operator can feel buried objects. A master/slave control method enables the operator to intuitively control all the excavator arm functions with one hand. The main features of the excavator are described in this article. (author)

Deformations and damage to buildings adjacent to deep excavations in soft soils

NARCIS (Netherlands)

Korff, M.

2009-01-01

The objective of this study is to gain insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations and to find a reliable method to design and monitor deep excavations in urban areas with soft soil conditions. The research focuses on typical Dutch conditions. The

100 Area excavation treatability test plan

International Nuclear Information System (INIS)

1993-08-01

This test plan documents the requirements for a treatability study on field radionuclide analysis and dust control techniques. These systems will be used during remedial actions involving excavation. The data from this treatability study will be used to support the feasibility study (FS) process. Excavation is one of the high-priority, near-term, treatability study needs identified in the program plan (DOE-RL 1992f). Excavation of contaminated soils and buried solid wastes is included in several of the alternatives identified in the 100 Area FS. Although a common activity, excavation has only been used occasionally at the Hanford Site for waste removal applications. The most recent applications are excavation of the 618-9 burial ground and partial remediation of the 316-5 process trenches (DOE-RL 1992a, 1992b). Both projects included excavation of soil and dust control (using water sprays). Excavation is a well-developed technology and equipment is readily available; however, certain aspects of the excavation process require testing before use in full-scale operations. These include the following: Measurement and control of excavation-generated dust and airborne contamination; verification of field analytical system capabilities; demonstration of soil removal techniques specific to the 100 Area waste site types and configurations. The execution of this treatability test may produce up to 500 yd 3 of contaminated soil, which will be used for future treatability tests. These tests may include soil washing with vitrification of the soil washing residuals. Other tests will be conducted if soil washing is not a viable alternative

Lightweight Robotic Excavation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Robust, lightweight, power-efficient excavation robots are mission enablers for lunar outposts and surface systems. Lunar excavators of this type cost-effectively...

A new unbiased stochastic derivative estimator for discontinuous sample performances with structural parameters

NARCIS (Netherlands)

Peng, Yijie; Fu, Michael C.; Hu, Jian Qiang; Heidergott, Bernd

In this paper, we propose a new unbiased stochastic derivative estimator in a framework that can handle discontinuous sample performances with structural parameters. This work extends the three most popular unbiased stochastic derivative estimators: (1) infinitesimal perturbation analysis (IPA), (2)

Crane and Excavator Operator.

Science.gov (United States)

Marine Corps Inst., Washington, DC.

Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on crane and excavator operation is designed to enable the crane and excavator operator to perform his/her duties more proficiently. Introductory materials include specific information for MCI students, a course introduction, and a study guide…

Excavation/Fill/Soil Disturbance, Self-Study #31419

Energy Technology Data Exchange (ETDEWEB)

Grogin, Phillip W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2018-02-06

This course, Excavation/Fill/Soil Disturbance Self-Study (#31419), presents an overview of the hazards, controls, and requirements that affect safe excavations at Los Alamos National Laboratory (LANL). An overview of the LANL excavation/fill/soil disturbance permit (EXID permit) approval process is also presented, along with potholing requirements for planning and performing excavations at LANL.

Excavations at Kainapirina (SAC), Watom Island, Papua New Guinea

International Nuclear Information System (INIS)

Green, R.C.; Anson, D.

1998-01-01

This paper is the final report on excavations in 1985 at the locality of Kainapirina (site SAC), situated on the Reber mission station adjacent to Rakival village on Watom Island. It backgrounds previous investigations there, the objectives of the 1985 endeavours, and the excavation strategies undertaken to achieve them. The occupation sequence based on stratigraphy, dating, and associated structural features is described and illustrated. Aspects of the human skeletal remains recovered are briefly reviewed; the economic evidence is discussed in detail. Analyses are provided of the various portable artefacts from these Lapita contexts, particularly stone adzes. obsidian, and pottery. These document an 'exotic to Watom' exchange component among the local manufactures. It is concluded that these 1985 excavations at SAC currently best enable an understanding of the significance of the entire Reber-Rakival Lapita site. (author)

Assessing Exhaustiveness of Stochastic Sampling for Integrative Modeling of Macromolecular Structures.

Science.gov (United States)

Viswanath, Shruthi; Chemmama, Ilan E; Cimermancic, Peter; Sali, Andrej

2017-12-05

Modeling of macromolecular structures involves structural sampling guided by a scoring function, resulting in an ensemble of good-scoring models. By necessity, the sampling is often stochastic, and must be exhaustive at a precision sufficient for accurate modeling and assessment of model uncertainty. Therefore, the very first step in analyzing the ensemble is an estimation of the highest precision at which the sampling is exhaustive. Here, we present an objective and automated method for this task. As a proxy for sampling exhaustiveness, we evaluate whether two independently and stochastically generated sets of models are sufficiently similar. The protocol includes testing 1) convergence of the model score, 2) whether model scores for the two samples were drawn from the same parent distribution, 3) whether each structural cluster includes models from each sample proportionally to its size, and 4) whether there is sufficient structural similarity between the two model samples in each cluster. The evaluation also provides the sampling precision, defined as the smallest clustering threshold that satisfies the third, most stringent test. We validate the protocol with the aid of enumerated good-scoring models for five illustrative cases of binary protein complexes. Passing the proposed four tests is necessary, but not sufficient for thorough sampling. The protocol is general in nature and can be applied to the stochastic sampling of any set of models, not just structural models. In addition, the tests can be used to stop stochastic sampling as soon as exhaustiveness at desired precision is reached, thereby improving sampling efficiency; they may also help in selecting a model representation that is sufficiently detailed to be informative, yet also sufficiently coarse for sampling to be exhaustive. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Effect of excavation method on rock mass displacement

International Nuclear Information System (INIS)

Sato, Toshinori; Kikuchi, Tadashi; Sugihara, Kozo

1998-01-01

Rock mass displacement measurements have been performed to understand rock mass behavior and its dependence on excavation method during drift excavation at the Tono mine. Rock mass displacements of 1.46 mm and 0.67 mm have been measured at one meter (0.33D: blasting, 0.42D: machine, D: width of drift) from the walls of drifts excavated by the drill and blasting method and machine, respectively. Numerical analysis of rock mass displacements with Finite Element Method has been performed assuming an excavation disturbed zone. Measured and analysed rock mass displacements are consistent with each other for the drift excavation by the drill and blasting method. The excavation disturbed zone was narrower for the drift excavated by machine than for the drift excavated by the drill and blasting method. (author)

Comparison between periodic and stochastic parabolic light trapping structures for thin-film microcrystalline Silicon solar cells.

Science.gov (United States)

Peters, M; Battaglia, C; Forberich, K; Bläsi, B; Sahraei, N; Aberle, A G

2012-12-31

Light trapping is of very high importance for silicon photovoltaics (PV) and especially for thin-film silicon solar cells. In this paper we investigate and compare theoretically the light trapping properties of periodic and stochastic structures having similar geometrical features. The theoretical investigations are based on the actual surface geometry of a scattering structure, characterized by an atomic force microscope. This structure is used for light trapping in thin-film microcrystalline silicon solar cells. Very good agreement is found in a first comparison between simulation and experimental results. The geometrical parameters of the stochastic structure are varied and it is found that the light trapping mainly depends on the aspect ratio (length/height). Furthermore, the maximum possible light trapping with this kind of stochastic structure geometry is investigated. In a second step, the stochastic structure is analysed and typical geometrical features are extracted, which are then arranged in a periodic structure. Investigating the light trapping properties of the periodic structure, we find that it performs very similar to the stochastic structure, in agreement with reports in literature. From the obtained results we conclude that a potential advantage of periodic structures for PV applications will very likely not be found in the absorption enhancement in the solar cell material. However, uniformity and higher definition in production of these structures can lead to potential improvements concerning electrical characteristics and parasitic absorption, e.g. in a back reflector.

The essence of excavators

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

Competition is hotting-up between rope shovel and hydraulic excavator manufacturers as demand mounts for surface loading equipment. The article gives an overview of major players and gives details of their popular models of excavators and rope shovels. It compares surface loading equipment from P & H, Bucyrus, THYI, OMZ, Komatsu, Hirachi, O & K and Liebherr. 4 tabs., 3 photos.

Excavating wide inclines in weak strata

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, N N [Ukrspetsstroiproekt (USSR)

1990-09-01

Discusses schemes for excavation of transport inclines in surface mines under conditions of weak, unstable rocks characterized by a high water content. The schemes are aimed at maximum reduction of excavation operations without infringing the safety of personnel. Use of walking draglines (the EhSh-20/90, EhSh-100/100 and EhSh-10/70) is evaluated. Optimum schemes for incline excavation and determining optimum slope inclination are described on the example of the Berezovsk brown coal surface mine in the USSR. Efficiency of optimum schemes is analyzed: range of excavation, safety degree, landslide hazards, water influx rate, accident rate, etc.

Customized excavators beat the odds

Energy Technology Data Exchange (ETDEWEB)

1991-10-01

Blackstone Mining, launched in 1983, is based in eastern Ohio, near Cadiz and specializes in stripping small properties for Ohio Edison. Specially modified hydraulic excavators and an efficient mining technique allow the mining of marginal coal deposits. In 1986 Ken McBeth, the company's founder begun using a Cat 245 hydraulic excavator to cleanly and efficiently load coal and also remove overburden. Modifications include: a mass excavator boom 5 feet longer to better reach over the sides of haul trucks and load from higher benches; and larger hydraulic cylinders to maintain earthmoving production. McBeth also devised a fast economical technique for extracting coal from the thin, narrow seams. Soft cover material is removed by excavator; the remaining sand and limestone are blasted to within 2 feet of the seam; the remaining material is removed by an agricultural tractor with a blade; an excavator loads the coal into haul trucks starting at the toe of the face and working backwards. Haul trucks are not placed directly on the seam. This prevents contamination, reducing the price of the coal. There is no wash plant; the coal is hauled direct to the utility. 4 photos.

GPS-Based Excavation Encroachment Notification

Science.gov (United States)

2011-10-31

Excavation damage is the primary threat to the integrity of the natural gas distribution system. According to the Common Ground Alliance, the two primary root causes of excavation damage are failure to notify the one-call center and careless excavati...

Mechanical tunnel excavation in welded tuff

International Nuclear Information System (INIS)

Sperry, P.E.

1991-01-01

The Technical Review Board for the US high-level radioactive waste facility at Yucca Mountain has recommended maximum use of open-quotes the most modern mechanical excavation techniques...in order to reduce disturbance to the rock walls and to achieve greater economy of time and cost.close quotes Tunnels for the waste repository at Yucca Mountain can be economically constructed with mechanical excavation equipment. This paper presents the results of mechanical excavation of a tunnel in welded tuff, similar to the tuffs of Yucca Mountain. These results are projected to excavation of emplacement drifts in Yucca Mountain using a current state-of-the-art tunnel boring machine (TBM)

Stochastic Erosion of Fractal Structure in Nonlinear Dynamical Systems

Science.gov (United States)

Agarwal, S.; Wettlaufer, J. S.

2014-12-01

We analyze the effects of stochastic noise on the Lorenz-63 model in the chaotic regime to demonstrate a set of general issues arising in the interpretation of data from nonlinear dynamical systems typical in geophysics. The model is forced using both additive and multiplicative, white and colored noise and it is shown that, through a suitable choice of the noise intensity, both additive and multiplicative noise can produce similar dynamics. We use a recently developed measure, histogram distance, to show the similarity between the dynamics produced by additive and multiplicative forcing. This phenomenon, in a nonlinear fractal structure with chaotic dynamics can be explained by understanding how noise affects the Unstable Periodic Orbits (UPOs) of the system. For delta-correlated noise, the UPOs erode the fractal structure. In the presence of memory in the noise forcing, the time scale of the noise starts to interact with the period of some UPO and, depending on the noise intensity, stochastic resonance may be observed. This also explains the mixing in dissipative dynamical systems in presence of white noise; as the fractal structure is smoothed, the decay of correlations is enhanced, and hence the rate of mixing increases with noise intensity.

Lightweight Bulldozer Attachment for Construction and Excavation on the Lunar Surface

Science.gov (United States)

Mueller, Robert; Wilkinson, R. Allen; Gallo, Christopher A.; Nick, Andrew J.; Schuler, Jason M.; King, Robert H.

2009-01-01

A lightweight bulldozer blade prototype has been designed and built to be used as an excavation implement in conjunction with the NASA Chariot lunar mobility platform prototype. The combined system was then used in a variety of field tests in order to characterize structural loads, excavation performance and learn about the operational behavior of lunar excavation in geotechnical lunar simulants. The purpose of this effort was to evaluate the feasibility of lunar excavation for site preparation at a planned NASA lunar outpost. Once the feasibility has been determined then the technology will become available as a candidate element in the NASA Lunar Surface Systems Architecture. In addition to NASA experimental testing of the LANCE blade, NASA engineers completed analytical work on the expected draft forces using classical soil mechanics methods. The Colorado School of Mines (CSM) team utilized finite element analysis (FEA) to study the interaction between the cutting edge of the LANCE blade and the surface of soil. FEA was also used to examine various load cases and their effect on the lightweight structure of the LANCE blade. Overall it has been determined that a lunar bulldozer blade is a viable technology for lunar outpost site preparation, but further work is required to characterize the behavior in 1/6th G and actual lunar regolith in a vacuum lunar environment.

The adoption of mechanized excavation techniques for the Superconducting Super Collider

International Nuclear Information System (INIS)

Laughton, C.; Nelson, P.; Lundin, T.

1991-01-01

The Superconducting Super Collider (SSC) is the latest and largest in a line of high-energy physics accelerator projects. The five increasingly energetic accelerators which make up the physics laboratory complex are to be housed almost entirely in subsurface structures, which will include over 100 km of small-diameter tunnel. Among other reasons, the Texas SSC site was chosen from a set of state proposals because of the suitability of the host rock materials for the performance of rapid and efficient excavation work. This site bedrock units are relatively soft and homogeneous and should allow for a maximum use of mechanical excavation plant for the various underground openings. This paper will review the site conditions and describe the developed understanding of geologic material behavior. With completion of planned large-scale in-situ studies of the ground behavior to provide acquisition of early site-specific excavation data, final design and construction detail of critical structures can be undertaken with the necessary degree of confidence to satisfy the stringent performance requirements. 5 refs., 4 figs., 6 tabs

AECL's excavation stability study - summary of observations

International Nuclear Information System (INIS)

Read, R.S.; Chandler, N.A.

1996-05-01

The Excavation Stability Study (ESS) was conducted at the 420 Level of the Underground Research Laboratory (URL) to evaluate stability and the extent of excavation damage in tunnels as a function of tunnel geometry and orientation, geology, and excavation method. A series of ovaloid and circular openings were used to achieve different boundary stress levels and near-field stress distributions to assess the effect of tunnel geometry on damage development. Several of these openings had sections in both granite and granodiorite lithology, providing a comparison of damage in rock types with different strength characteristics. Damage around circular tunnels (one excavated by drill-and-blast, the other by mechanical means) was also investigated. The study.showed that mechanically stable openings can be excavated in the most adverse stress conditions at the 420 Level of the URL. In addition, it was shown that tunnel stability is sensitive to tunnel shape, variations in geology, and to some extent, the excavation method. Findings of the study are relevant in developing design criteria, and in assessing the feasibility of constructing large ovaloid openings in adverse stress conditions. This report summarizes the preliminary observations related to tunnel stability and excavation damage. (author). 8 refs., 7 tabs., 23 figs

Stochastic analysis of the earthquake response of structures with a view to soil-structure interaction

International Nuclear Information System (INIS)

Bauer, J.

1980-01-01

Thesis dealing with the analysis of earthquake response of structures. In order to achieve a reliable risk assessment, the results of the seismic risk analysis have to be seen in an overall view together with the results of stochastic vibrational analyses, and the data on maximum supportable stresses of the structure. Taking into account stochastic seismic focus models and calculation methods is of special significance in this connection. Based upon well-known seismic risk assessment models, the calculation of the annual probability for exceeding the acceleration level is carried out also considering the length of the failure zone, assuming that the energy released during an earthquake is uniformly, distributed over this fracture zone. The strong influence of local parameters on the annual exceeding probability is shown by a sensitivity analysis. (orig./RW) [de

Development of digital photogrammetry for measurements of displacements in underground excavation

International Nuclear Information System (INIS)

Ohnishi, Yuzo; Ohtsu, Hiroyasu; Nishiyama, Satoshi; Ono, Tetsu; Matsui, Hiroya

2002-03-01

Because deformations are important indicators of the degree of stability during construction of rock structures, monitoring of deformation is a key element of construction of tunnels and structures for the underground research laboratory. Especially in the construction and maintenance of underground excavation, monitoring of deformations is needed for obtaining useful information to control its stability. We have been developing the application of digital photogrammetry to monitoring techniques in rock structures. Photogrammetric process has undergone a remarkable evolution with its transformation into digital photogrammetry. Photogrammetry has the advantage of measuring deformation of an object by some photos with easy measurements and excellent cost performance. In this paper, we present that the digital photogrammetry can monitor the displacements of the underground excavation accurately along with a capability of real-time measurement. (author)

Properties of Ti-6Al-4V non-stochastic lattice structures fabricated via electron beam melting

International Nuclear Information System (INIS)

Cansizoglu, O.; Harrysson, O.; Cormier, D.; West, H.; Mahale, T.

2008-01-01

This paper addresses foams which are known as non-stochastic foams, lattice structures, or repeating open cell structure foams. The paper reports on preliminary research involving the design and fabrication of non-stochastic Ti-6Al-4V alloy structures using the electron beam melting (EBM) process. Non-stochastic structures of different cell sizes and densities were investigated. The structures were tested in compression and bending, and the results were compared to results from finite element analysis simulations. It was shown that the build angle and the build orientation affect the properties of the lattice structures. The average compressive strength of the lattice structures with a 10% relative density was 10 MPa, the flexural modulus was 200 MPa and the strength to density ration was 17. All the specimens were fabricated on the EBM A2 machine using a melt speed of 180 mm/s and a beam current of 2 mA. Future applications and FEA modeling were discussed in the paper

Stochastic modeling of reinforced concrete structures exposed to chloride attack

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Frier, Christian

2004-01-01

For many reinforced concrete structures corrosion of reinforcement is an important problem since it can result in expensive maintenance and repair actions. Further, a significant reduction of the load-bearing capacity can occur. One mode of corrosion initiation is that the chloride content around...... concentration and reinforcement cover depth are modeled by stochastic fields. The paper contains a description of the parameters to be included in a stochastic model and a proposal for the information needed to obtain values for the parameters in order to be able to perform reliability investigations....... The distribution of the time to initiation of corrosion is estimated by simulation. As an example a bridge pier in a marine environment is considered....

Stochastic Modeling of Reinforced Concrete Structures Exposed to Chloride Attack

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Frier, Christian

2003-01-01

For many reinforced concrete structures corrosion of reinforcement is an important problem since it can result in expensive maintenance and repair actions. Further, a significant reduction of the load-bearing capacity can occur. One mode of corrosion initiation is that the chloride content around...... concentration and reinforcement cover depth are modeled by stochastic fields. The paper contains a description of the parameters to be included in a stochastic model and a proposal for the information needed to obtain values for the parameters in order to be ab le to perform reliability investigations....... The distribution of the time to initiation of corrosion is estimated by simulation. As an example a bridge pier in a marine environment is considered....

Reliability estimation of structures under stochastic loading—A case study on nuclear piping

International Nuclear Information System (INIS)

Hari Prasad, M.; Rami Reddy, G.; Dubey, P.N.; Srividya, A.; Verma, A.K.

2013-01-01

Highlights: ► Structures are generally subjected to different types of loadings. ► One such type of loading is random sequence and has been treated as a stochastic fatigue loading. ► In this methodology both stress amplitude and number of cycles to failure have been considered as random variables. ► The methodology has been demonstrated with a case study on nuclear piping. ► The failure probability of piping has been estimated as a function of time. - Abstract: Generally structures are subjected to different types of loadings throughout their life time. These loads can be either discrete in nature or continuous in nature and also these can be either stationary or non stationary processes. This means that the structural reliability analysis not only considers random variables but also considers random variables which are functions of time, referred to as stochastic processes. A stochastic process can be viewed as a family of random variables. When a structure is subjected to a random loading, based on the stresses developed in the structure and failure criteria the failure probability can be estimated. In practice the structures are designed with higher factor of safety to take care of such random loads. In such cases the structure will fail only when the random loads are cyclic in nature. In traditional reliability analysis, the variation in the load is treated as a random variable and to account for the number of occurrences of the loading the concept of extreme value theory is used. But with this method one is neglecting the damage accumulation that will take place from one loading to another loading. Hence, in this paper, a new way of dealing with these types of problems has been discussed by using the concept of stochastic fatigue loading. The random loading has been considered as earthquake loading. The methodology has been demonstrated with a case study on nuclear power plant piping.

The interpolation method of stochastic functions and the stochastic variational principle

International Nuclear Information System (INIS)

Liu Xianbin; Chen Qiu

1993-01-01

Uncertainties have been attaching more importance to increasingly in modern engineering structural design. Viewed on an appropriate scale, the inherent physical attributes (material properties) of many structural systems always exhibit some patterns of random variation in space and time, generally the random variation shows a small parameter fluctuation. For a linear mechanical system, the random variation is modeled as a random one of a linear partial differential operator and, in stochastic finite element method, a random variation of a stiffness matrix. Besides the stochasticity of the structural physical properties, the influences of random loads which always represent themselves as the random boundary conditions bring about much more complexities in structural analysis. Now the stochastic finite element method or the probabilistic finite element method is used to study the structural systems with random physical parameters, whether or not the loads are random. Differing from the general finite element theory, the main difficulty which the stochastic finite element method faces is the inverse operation of stochastic operators and stochastic matrices, since the inverse operators and the inverse matrices are statistically correlated to the random parameters and random loads. So far, many efforts have been made to obtain the reasonably approximate expressions of the inverse operators and inverse matrices, such as Perturbation Method, Neumann Expansion Method, Galerkin Method (in appropriate Hilbert Spaces defined for random functions), Orthogonal Expansion Method. Among these methods, Perturbation Method appear to be the most available. The advantage of these methods is that the fairly accurate response statistics can be obtained under the condition of the finite information of the input. However, the second-order statistics obtained by use of Perturbation Method and Neumann Expansion Method are not always the appropriate ones, because the relevant second

Stochastic models for structured populations scaling limits and long time behavior

CERN Document Server

Meleard, Sylvie

2015-01-01

In this contribution, several probabilistic tools to study population dynamics are developed. The focus is on scaling limits of qualitatively different stochastic individual based models and the long time behavior of some classes of limiting processes. Structured population dynamics are modeled by measure-valued processes describing the individual behaviors and taking into account the demographic and mutational parameters, and possible interactions between individuals. Many quantitative parameters appear in these models and several relevant normalizations are considered, leading  to infinite-dimensional deterministic or stochastic large-population approximations. Biologically relevant questions are considered, such as extinction criteria, the effect of large birth events, the impact of  environmental catastrophes, the mutation-selection trade-off, recovery criteria in parasite infections, genealogical properties of a sample of individuals. These notes originated from a lecture series on Structured P...

The underground research laboratory room 209 excavation response test

International Nuclear Information System (INIS)

Simmons, G.R.

1992-02-01

The response of the rock mass to excavation is an important factor in the design and performance of underground excavations and installations. This is particularly true in the excavation of vaults for the disposal of nuclear fuel waste, where the conditions in the rock mass around the disposal areas may affect the performance of engineered sealing systems installed to isolate the waste. The factors influencing, and mechanisms controlling, rock mass response to excavation must be understood in order to accommodate excavation response effects in disposal vault design and construction

Overview of the excavation disturbance experiment at the Kamaishi mine

International Nuclear Information System (INIS)

Matsui, Hiroya; Sato, Toshinori; Sugihara, Kozo; Kikuchi, Tadashi

1999-01-01

Excavation of an underground drift disturbs the rock mass around the opening by each of the following processes: Fracturing in the vicinity of opening induced by the excavation work and stress concentration. Changes in the apertures of existing fractures due to stress redistribution. Changes in water pressure around the opening due to water inflow and chemical changes due to the increased oxygen supply to the rock and such phenomena as degassing of groundwater. All of these mechanical, hydrological, and chemical changes to the rock mass are termed excavation disturbance and the affected area is called the 'Excavation Disturbed Zone (EDZ)'. The portion of the EDZ in which the rock mass is fractured due to excavation is called the Excavation Damaged Zone'. This experiment is focused on the mechanical and hydrological property changes caused by excavation, the degree and extend of which is important for the design, excavation and support of underground openings. The relevance of the EDZ for the geological isolation of nuclear waste disposal may be summarized as: 1) Relevance to near-field performance assessment. The EDZ is of importance for near-field performance assessment, as the development of new fractures and the opening of existing fractures due to excavation may create preferential pathways for mass transport from the engineered barrier system to natural transmissive flowpaths. 2) Relevance to the design, excavation and sealing of a repository. The excavation method affects the properties and the extend of the excavation damaged zone. The shape and the scale of the underground opening, and whether the underground opening is backfilled after excavation, will affect the final stress state. It is important to understand the EDZ for the design, excavation and sealing of a repository. 3) Initial and boundary conditions of in situ experiments. Information about the EDZ is necessary for the design and interpretation of certain in situ experiments. (author)

Mining technology development for hard rock excavation

International Nuclear Information System (INIS)

Hustrulid, W.; Cudnick, R.; Trent, R.; Holmberg, R.

1980-01-01

A research facility has been established in the granitic gneiss of the CSM Experimental Mine at Idaho Springs, Colorado, for the purpose of evaluating/developing mining, geologic and geotechnical procedures appropriate for use in establishing nuclear waste repositories in hard rock. An experimental room has been excavated using careful blasting procedures. The extent and magnitude of blast damage is being evaluated. Structural geology is being mapped to assess continuity

Uncertainty Aware Structural Topology Optimization Via a Stochastic Reduced Order Model Approach

Science.gov (United States)

Aguilo, Miguel A.; Warner, James E.

2017-01-01

This work presents a stochastic reduced order modeling strategy for the quantification and propagation of uncertainties in topology optimization. Uncertainty aware optimization problems can be computationally complex due to the substantial number of model evaluations that are necessary to accurately quantify and propagate uncertainties. This computational complexity is greatly magnified if a high-fidelity, physics-based numerical model is used for the topology optimization calculations. Stochastic reduced order model (SROM) methods are applied here to effectively 1) alleviate the prohibitive computational cost associated with an uncertainty aware topology optimization problem; and 2) quantify and propagate the inherent uncertainties due to design imperfections. A generic SROM framework that transforms the uncertainty aware, stochastic topology optimization problem into a deterministic optimization problem that relies only on independent calls to a deterministic numerical model is presented. This approach facilitates the use of existing optimization and modeling tools to accurately solve the uncertainty aware topology optimization problems in a fraction of the computational demand required by Monte Carlo methods. Finally, an example in structural topology optimization is presented to demonstrate the effectiveness of the proposed uncertainty aware structural topology optimization approach.

Heart rot hotel: fungal communities in red-cockaded woodpecker excavations

Science.gov (United States)

Michelle A. Jusino; Daniel L. Lindner; Mark T. Banik; Jeffrey R. Walters

2015-01-01

Tree-cavity excavators such as woodpeckers are ecosystem engineers that have potentially complex but poorly documented associations with wood decay fungi. Fungi facilitate cavity excavation by preparing and modifying excavation sites for cavity excavators. Associations between fungi and endangered red-cockaded woodpeckers (RCWs) are particularly interesting because...

Summary report of soil removal preliminary excavations

International Nuclear Information System (INIS)

Wickland, C.E.

1975-01-01

This report discusses a proposed technique to remove small areas, less than 2,000 m 2 , of contaminated soil and the results of an actual excavation. Based on the results of a trial excavation in uncontaminated soil and an excavation of two trenches in contaminated soil, it is concluded that the techniques described are a satisfactory means of contaminated soil removal. It can be done safely with a release of airborne plutonium a factor of 10 or more below the Environmental Protection Administration (EPA) limit

A Prototype Bucket Wheel Excavator for the Moon, Mars and Phobos

Science.gov (United States)

Muff, T.; Johnson, L.; King, R.; Duke, M. B.

2004-02-01

Excavation of surface regolith material is the first step in processes to extract volatile materials from planetary surface regolith for the production of propellant and life support consumables. Typically, concentrations of volatiles are low, so relatively large amounts of material must be excavated. A bucket wheel excavator is proposed, which has the capability of continuous excavation, which is readily adapted to granular regolith materials as found on the Moon, in drift deposits on Mars, and probably on the surface of asteroids and satellites, such as Phobos. The bucket wheel excavator is relatively simple, compared to machines such as front end loaders. It also has the advantage that excavation forces are principally horizontal rather than vertical, which minimizes the need for excavator mass and suits it to operations in reduced gravity fields. A prototype small bucket wheel excavator has been built at approximately the scale of the rovers that are carried to Mars on the Mars Exploration Rover Mission. The prototype allows the collection of data on forces exerted and power requirements for excavation and will provide data on which more efficient designs can be based. At excavation rates in the vicinity of one rover mass of material excavated per hour, tests of the prototype demonstrate that the power required is largely that needed to operate the excavator hardware and not related strongly to the amount of material excavated. This suggests that the excavation rate can be much larger for the same excavation system mass. Work on this prototype is continuing on the details of transfer of material from the bucket wheel to an internal conveyor mechanism, which testing demonstrated to be problematic in the current design.

CLASSIFICATION OF THE MGR SUBSURFACE EXCAVATION SYSTEM

International Nuclear Information System (INIS)

R. Garrett

1999-01-01

The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface excavation system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

Optimal Stochastic Modeling and Control of Flexible Structures

Science.gov (United States)

1988-09-01

1.37] and McLane [1.18] considered multivariable systems and derived their optimal control characteristics. Kleinman, Gorman and Zaborsky considered...Leondes [1.72,1.73] studied various aspects of multivariable linear stochastic, discrete-time systems that are partly deterministic, and partly stochastic...June 1966. 1.8. A.V. Balaknishnan, Applied Functional Analaysis , 2nd ed., New York, N.Y.: Springer-Verlag, 1981 1.9. Peter S. Maybeck, Stochastic

Optimization design of foundation excavation for Xiluodu super-high arch dam in China

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Qixiang Fan

2015-04-01

Full Text Available With better understanding of the quality and physico-mechanical properties of rocks of dam foundation, and the physico-mechanical properties and structure design of arch dam in association with the foundation excavation of Xiluodu arch dam, the excavation optimization design was proposed for the foundation surface on the basis of feasibility study. Common analysis and numerical analysis results demonstrated the feasibility of using the weakly weathered rocks III1 and III2 as the foundation surface of super-high arch dam. In view of changes in the geological conditions at the dam foundation along the riverbed direction, the design of extending foundation surface excavation area and using consolidating grouting and optimizing structure of dam bottom was introduced, allowing for harmonization of the arch dam and foundation. Three-dimensional (3D geomechanics model test and finite element analysis results indicated that the dam body and foundation have good overload stability and high bearing capacity. The monitoring data showed that the behaviors of dam and foundation correspond with the designed patterns in the construction period and the initial operation period.

Development of excavation technologies at the Canadian underground research laboratory

International Nuclear Information System (INIS)

Kuzyk, Gregory W.; Martino, Jason B.

2008-01-01

Several countries, Canada being among them, are developing concepts for disposal of used fuel from power generating nuclear reactors. As in underground mining operations, the disposal facilities will require excavation of many kilometres of shafts and tunnels through the host rock mass. The need to maintain the stability of excavations and safety of workers will be of paramount importance. Also, excavations required for many radioactive waste repositories will ultimately need to be backfilled and sealed to maintain stability and minimize any potential for migration of radionuclides, should they escape their disposal containers. The method used to excavate the tunnels and shafts, and the rock damage that occurs due to excavation, will greatly affect the performance characteristics of repository sealing systems. The underground rock mechanics and geotechnical engineering work performed at the Canadian Underground Research Laboratory (URL) has led to the development of excavation technologies that reduce rock damage in subsurface excavations. This paper discusses the excavation methods used to construct the URL and their application in planning for the construction of similar underground laboratories and repositories for radioactive wastes. (author)

Field Observation of Soil Displacements Resulting Due Unsupported Excavation and Its Effects on Proposed Adjacent Piles

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Ala Nasir Al-Jorany

2016-06-01

Full Text Available Soil movement resulting due unsupported excavation nearby axially loaded piles imposes significant structural troubles on geotechnical engineers especially for piles that are not designed to account for loss of lateral confinement. In this study the field excavation works of 7.0 m deep open tunnel was continuously followed up by the authors. The work is related to the project of developing the Army canal in the east of Baghdad city in Iraq. A number of selected points around the field excavation are installed on the ground surface at different horizontal distance. The elevation and coordinates of points are recorded during 23 days with excavation progress period. The field excavation process was numerically simulated by using the finite element package PLAXIS 3D foundation. The obtained analysis results regarding the displacements of the selected points are compared with the field observation for verification purpose. Moreover, finite element analysis of axially loaded piles that are presumed to be existed at the locations of the observation points is carried out to study the effect of excavation on full scale piles behaviors. The field observation monitored an upward movement and positive lateral ground movement for shallow excavation depth. Later on and as the excavation process went deeper, a downward movement and negative lateral ground movement are noticed. The analyses results are in general well agreed with the monitored values of soil displacements at the selected points. It is found also that there are obvious effects of the nearby excavation on the presumed piles in terms of displacements and bending moments.

100 area excavation treatability test plan

International Nuclear Information System (INIS)

1993-05-01

This test plan documents the requirements for a treatability study on field radionuclide analysis and dust control techniques. These systems will be used during remedial actions involving excavation. The data from this treatability study will be used to support the feasibility study (FS) process. Development and screening of remedial alternatives for the 100 Area, using existing data, have been completed and are documented in the 100 Area Feasibility Study, Phases 1 and 2 (DOE-RL 1992a). Based on the results of the FS, the Treatability Study Program Plan (DOE-RL 1992b) identifies and prioritizes treatability studies for the 100 Area. The data from the treatability study program support future focused FS, interim remedial measures (IRM) selection, operable unit final remedy selection, remedial design, and remedial actions. Excavation is one of the high-priority, near-term, treatability study needs identified in the program plan (DOE-RL 1992b). Excavation of contaminated soils and buried solid wastes is included in several of the alternatives identified in the 100 Area FS. Although a common activity, excavation has only been used occasionally at the Hanford Site for waste removal applications

Theory and technology of rock excavation for civil engineering

CERN Document Server

Zou, Dingxiang

2017-01-01

This book summarizes the technical advances in recent decades and the various theories on rock excavation raised by scholars from different countries, including China and Russia. It not only focuses on rock blasting but also illustrates a number of non-blasting methods, such as mechanical excavation in detail. The book consists of 3 parts: Basic Knowledge, Surface Excavation and Underground Excavation. It presents a variety of technical methods and data from diverse sources in the book, making it a valuable theoretical and practical reference resource for engineers, researchers and postgraduates alike.

Development of excavator training simulator using leap motion controller

Science.gov (United States)

Fahmi, F.; Nainggolan, F.; Andayani, U.; Siregar, B.

2018-03-01

Excavator is a heavy machinery that is used for many industries purposes. Controlling the excavator is not easy. Its operator has to be trained well in many skills to make sure it is safe, effective, and efficient while using the excavator. In this research, we proposed a virtual reality excavator simulator supported by a device called Leap Motion Controller that supports finger and hand motions as an input. This prototype will be developed than in the virtual reality environment to give a more real sensing to the user.

Outline and results of study on excavation response of rock mass around shaft in shaft excavation effects project

International Nuclear Information System (INIS)

Sugihara, Kozo; Matsui, Hiroya; Sato, Toshinori

1993-01-01

A shaft, with a diameter of 6 m and a depth of 150 m, has been newly excavated in sedimentary rock and excavation response of rock mass around the shaft has been measured and analyzed. Excavation response has been evaluated based on the results of measurement of rock mass movement, such as displacement and strain, and change of rock property, such as deformability and permeability. This study indicates that rock property has been changed with in about 1 m from the shaft wall, and rock mass movement and property change has been influenced by rock facies, fracture and re-distributed stress. The relation between property change and these factors is remained to be evaluated in future study. (author)

Real-time support for precision excavation of radionuclide-contaminated soils

International Nuclear Information System (INIS)

Durham, L. A.; Johnson, R. L.

2003-01-01

Traditional approaches to excavation design for sites with radionuclide-contaminated soils generally involve work plans with fixed excavation footprints and post-excavation verification sampling. Recent advancements in real-time data collection systems, combined with data loggers, location control systems, and secure project-support Web sites, allow for an alternative, more precise approach to excavation design and implementation. In this mode, traditional work plans are replaced with dynamic work plans. Excavation efforts are organized by lift, with real-time dig face screening performed and the data for each lift analyzed, before excavation continues. Rather than specifying excavation footprints, dynamic work plans identify the decision logic that will be used to determine footprints based on real-time data collection. The level of investment in excavation support data collection can be balanced against potential cost savings realized through waste stream minimization. Secure project support Web sites ensure that data sets generated during the remediation process are readily accessible to all who need to see them, whether they are on site or not. These include regulators, program managers, and technical support staff. This type of Web site allows for quick problem resolution, increased transparency in field decision making, and more efficient allocation of expensive technical staff time

THE IMPROVEMENT OF THE EXCAVATION METHODS IN BAUXITE DEPOSITS

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Borislav Perić

1990-12-01

Full Text Available The underground bauxite excavation in Yugoslavia is getting more important recently due to gradual exploitation of shallow deposits. The main excavation method is sublevel caving method. That technology of exploitation is characterized by high excavation loosses reaching even to 50% due to mixing of bauxite with waste. By beds with competent limestone roof which are not liable to direct caving are formed unplanned open spaces so the work safety is often dangercd by sudden caving. That was the reason for carrying out the observations in situ and investigations on mathematical models to define boundary of excavated space stability. This investigation were the basis for the new conception of further excavation of the »Jukići-Didare« mine with the application of even three exploitation methods maximally adapted to the characteristics of the remaining part of deposit.

Structural factoring approach for analyzing stochastic networks

Science.gov (United States)

Hayhurst, Kelly J.; Shier, Douglas R.

1991-01-01

The problem of finding the distribution of the shortest path length through a stochastic network is investigated. A general algorithm for determining the exact distribution of the shortest path length is developed based on the concept of conditional factoring, in which a directed, stochastic network is decomposed into an equivalent set of smaller, generally less complex subnetworks. Several network constructs are identified and exploited to reduce significantly the computational effort required to solve a network problem relative to complete enumeration. This algorithm can be applied to two important classes of stochastic path problems: determining the critical path distribution for acyclic networks and the exact two-terminal reliability for probabilistic networks. Computational experience with the algorithm was encouraging and allowed the exact solution of networks that have been previously analyzed only by approximation techniques.

Stochastic output error vibration-based damage detection and assessment in structures under earthquake excitation

Science.gov (United States)

Sakellariou, J. S.; Fassois, S. D.

2006-11-01

A stochastic output error (OE) vibration-based methodology for damage detection and assessment (localization and quantification) in structures under earthquake excitation is introduced. The methodology is intended for assessing the state of a structure following potential damage occurrence by exploiting vibration signal measurements produced by low-level earthquake excitations. It is based upon (a) stochastic OE model identification, (b) statistical hypothesis testing procedures for damage detection, and (c) a geometric method (GM) for damage assessment. The methodology's advantages include the effective use of the non-stationary and limited duration earthquake excitation, the handling of stochastic uncertainties, the tackling of the damage localization and quantification subproblems, the use of "small" size, simple and partial (in both the spatial and frequency bandwidth senses) identified OE-type models, and the use of a minimal number of measured vibration signals. Its feasibility and effectiveness are assessed via Monte Carlo experiments employing a simple simulation model of a 6 storey building. It is demonstrated that damage levels of 5% and 20% reduction in a storey's stiffness characteristics may be properly detected and assessed using noise-corrupted vibration signals.

Stochastic Geometric Network Models for Groups of Functional and Structural Connectomes

Science.gov (United States)

Friedman, Eric J.; Landsberg, Adam S.; Owen, Julia P.; Li, Yi-Ou; Mukherjee, Pratik

2014-01-01

Structural and functional connectomes are emerging as important instruments in the study of normal brain function and in the development of new biomarkers for a variety of brain disorders. In contrast to single-network studies that presently dominate the (non-connectome) network literature, connectome analyses typically examine groups of empirical networks and then compare these against standard (stochastic) network models. Current practice in connectome studies is to employ stochastic network models derived from social science and engineering contexts as the basis for the comparison. However, these are not necessarily best suited for the analysis of connectomes, which often contain groups of very closely related networks, such as occurs with a set of controls or a set of patients with a specific disorder. This paper studies important extensions of standard stochastic models that make them better adapted for analysis of connectomes, and develops new statistical fitting methodologies that account for inter-subject variations. The extensions explicitly incorporate geometric information about a network based on distances and inter/intra hemispherical asymmetries (to supplement ordinary degree-distribution information), and utilize a stochastic choice of networks' density levels (for fixed threshold networks) to better capture the variance in average connectivity among subjects. The new statistical tools introduced here allow one to compare groups of networks by matching both their average characteristics and the variations among them. A notable finding is that connectomes have high “smallworldness” beyond that arising from geometric and degree considerations alone. PMID:25067815

Radon in an underground excavation site in Helsinki

International Nuclear Information System (INIS)

Venelampi, E.

2004-01-01

The paper reports on radon measurements and actions taken in a large underground excavation site in Helsinki, where a coal store was excavated underneath an existing power plant. The measurements were carried out by taking grab samples using Lucas type scintillation cells. Large variations in radon concentrations were observed during the three-year study. The reasons for variations are discussed and recommendations are given for radon monitoring procedures in underground excavation sites. The importance of ventilation to reduce the radon level is stressed. (P.A.)

Characterization of stochastic uncertainty in the 1996 performance assessment for the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Helton, Jon Craig; Davis, Freddie J.; Johnson, J.D.

2000-01-01

The 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) maintains a separation between stochastic (i.e., aleatory) and subjective (i.e., epistemic) uncertainty, with stochastic uncertainty arising from the possible disruptions that could occur at the WIPP over the 10,000 yr regulatory period specified by the US Environmental Protection Agency (40 CFR 191, 40 CFR 194) and subjective uncertainty arising from an inability to uniquely characterize many of the inputs required in the 1996 WIPP PA. The characterization of stochastic uncertainty is discussed including drilling intrusion time, drilling location penetration of excavated/nonexcavated areas of the repository, penetration of pressurized brine beneath the repository, borehole plugging patterns, activity level of waste, and occurrence of potash mining. Additional topics discussed include sampling procedures, generation of individual 10,000 yr futures for the WIPP, construction of complementary cumulative distribution functions (CCDFs), mechanistic calculations carried out to support CCDF construction the Kaplan/Garrick ordered triple representation for risk and determination of scenarios and scenario probabilities

Identifying the cutting tool type used in excavations using neural networks

Energy Technology Data Exchange (ETDEWEB)

Jonak, J.; Gajewski, J. [Lublin University of Technology, Lublin (Poland). Faculty of Mechanical Engineering

2006-03-15

The paper presents results of preliminary research on utilising neural networks to identify excavating cutting tool's type used in multi-tool excavating heads of mechanical coal miners. Such research is necessary to identify rock excavating process with a given head, and construct adaptation systems for control of excavating process with such a head.

Research on Trajectory Planning and Autodig of Hydraulic Excavator

Directory of Open Access Journals (Sweden)

Bin Zhang

2017-01-01

Full Text Available As the advances in computer control technology keep emerging, robotic hydraulic excavator becomes imperative. It can improve excavation accuracy and greatly reduce the operator’s labor intensity. The 12-ton backhoe bucket excavator has been utilized in this research work where this type of excavator is commonly used in engineering work. The kinematics model of operation device (boom, arm, bucket, and swing in excavator is established in both Denavit-Hartenberg coordinates for easy programming and geometric space for avoiding blind spot. The control approach is based on trajectory tracing method with displacements and velocities feedbacks. The trajectory planning and autodig program is written by Visual C++. By setting the bucket teeth’s trajectory, the program can automatically plan the velocity and acceleration of each hydraulic cylinder and motor. The results are displayed through a 3D entity simulation environment which can present real-time movements of excavator kinematics. Object-Oriented Graphics Rendering Engine and skeletal animation are used to give accurate parametric control and feedback. The simulation result shows that a stable linear autodig can be achieved. The errors between trajectory planning command and simulation model are analyzed.

Finite-element modelling of geomechanical and hydraulic responses to the room 209 heading extension excavation response experiment 2: post-excavation analysis of experimental results

Energy Technology Data Exchange (ETDEWEB)

Chan, T; Griffith, P; Nakka, B W; Khair, K R

1993-07-01

An in situ excavation response test was conducted at the 240 Level of the Underground Research Laboratory (URL) in conjunction with the excavation of a tunnel (Room 209) through a narrow, near-vertical, water-bearing fracture oriented almost perpendicular to the tunnel axis. This report presents a post-excavation analysis of the predicted mechanical response of the granitic rock mass to the tunnel excavation and the near-field hydraulic response of the fracture zone, compares the numerical modelling predictions with the actual measured response, provides information on the rock mass and fracture from back-analysis of the responses, and makes recommendations for future experiments. Results indicate that displacements and stress changes were reasonably well predicted. Pressure drops at hydrology boreholes and inflow to the tunnel were overpredicted, and fracture permeability changes were underpredicted. The permeability change is considered too large to be solely stress-induced. The back-calculated deformation modulus indicated nonlinear softening of the rock within 3.5 m of the tunnel wall. This is likely due to both excavation damage and the confining stress dependence of the modulus. For future excavation experiments it is recommended that mechanical excavation should replace the drill-and-blast technique; excavation damage should be incorporated into mechanical models; an improved hydraulic fracture model should be developed; and a coupled geomechanical-hydraulic analysis of fracture flow should be developed. (author). 16 refs., 15 tabs., 156 figs.

Finite-element modelling of geomechanical and hydraulic responses to the room 209 heading extension excavation response experiment 2: post-excavation analysis of experimental results

International Nuclear Information System (INIS)

Chan, T.; Griffith, P.; Nakka, B.W.; Khair, K.R.

1993-07-01

An in situ excavation response test was conducted at the 240 Level of the Underground Research Laboratory (URL) in conjunction with the excavation of a tunnel (Room 209) through a narrow, near-vertical, water-bearing fracture oriented almost perpendicular to the tunnel axis. This report presents a post-excavation analysis of the predicted mechanical response of the granitic rock mass to the tunnel excavation and the near-field hydraulic response of the fracture zone, compares the numerical modelling predictions with the actual measured response, provides information on the rock mass and fracture from back-analysis of the responses, and makes recommendations for future experiments. Results indicate that displacements and stress changes were reasonably well predicted. Pressure drops at hydrology boreholes and inflow to the tunnel were overpredicted, and fracture permeability changes were underpredicted. The permeability change is considered too large to be solely stress-induced. The back-calculated deformation modulus indicated nonlinear softening of the rock within 3.5 m of the tunnel wall. This is likely due to both excavation damage and the confining stress dependence of the modulus. For future excavation experiments it is recommended that mechanical excavation should replace the drill-and-blast technique; excavation damage should be incorporated into mechanical models; an improved hydraulic fracture model should be developed; and a coupled geomechanical-hydraulic analysis of fracture flow should be developed. (author). 16 refs., 15 tabs., 156 figs

Choroidal Excavation in Eye with Normal Tension Glaucoma

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Kazunobu Asao

2014-05-01

Full Text Available Purpose: To report the case of an eye with normal tension glaucoma and a choroidal excavation. Methods: This is an observational case report. Results: A 59-year-old woman with normal tension glaucoma had a choroidal excavation in the left eye. Her best-corrected visual acuity and intraocular pressure were within normal limits and had been stable for 5 years. Fundus examination showed a small white lesion inferior to the macula and a nerve fiber layer defect at the inferior edge of the optic disc. Humphrey Field Analyzer (HFA showed visual field defects corresponding to the nerve fiber layer defect with C30-2, and a central scotoma superior to the macula with C10-2. Optical coherence tomography (OCT showed a 150-µm deep choroidal excavation. Disruptions of the IS/OS line were detected only in the area inferior to the choroidal excavation. During the 5 months of follow-up, her best-corrected visual acuity remained at 1.0 and the IOP ranged from 12 to 14 mm Hg in the left eye. The fundus and OCT images did not deteriorate and the choroidal excavation did not enlarge. Conclusions: The disruption of the inner/outer segment (IS/OS line was detected only at the area surrounding the choroidal excavation. OCT examinations are useful in assessing the area of the residual IS/OS line, and HFA can be used to estimate the residual central visual field.

Structural damage diagnosis based on on-line recursive stochastic subspace identification

International Nuclear Information System (INIS)

Loh, Chin-Hsiung; Weng, Jian-Huang; Liu, Yi-Cheng; Lin, Pei-Yang; Huang, Shieh-Kung

2011-01-01

This paper presents a recursive stochastic subspace identification (RSSI) technique for on-line and almost real-time structural damage diagnosis using output-only measurements. Through RSSI the time-varying natural frequencies of a system can be identified. To reduce the computation time in conducting LQ decomposition in RSSI, the Givens rotation as well as the matrix operation appending a new data set are derived. The relationship between the size of the Hankel matrix and the data length in each shifting moving window is examined so as to extract the time-varying features of the system without loss of generality and to establish on-line and almost real-time system identification. The result from the RSSI technique can also be applied to structural damage diagnosis. Off-line data-driven stochastic subspace identification was used first to establish the system matrix from the measurements of an undamaged (reference) case. Then the RSSI technique incorporating a Kalman estimator is used to extract the dynamic characteristics of the system through continuous monitoring data. The predicted residual error is defined as a damage feature and through the outlier statistics provides an indicator of damage. Verification of the proposed identification algorithm by using the bridge scouring test data and white noise response data of a reinforced concrete frame structure is conducted

A heterogeneous stochastic FEM framework for elliptic PDEs

International Nuclear Information System (INIS)

Hou, Thomas Y.; Liu, Pengfei

2015-01-01

We introduce a new concept of sparsity for the stochastic elliptic operator −div(a(x,ω)∇(⋅)), which reflects the compactness of its inverse operator in the stochastic direction and allows for spatially heterogeneous stochastic structure. This new concept of sparsity motivates a heterogeneous stochastic finite element method (HSFEM) framework for linear elliptic equations, which discretizes the equations using the heterogeneous coupling of spatial basis with local stochastic basis to exploit the local stochastic structure of the solution space. We also provide a sampling method to construct the local stochastic basis for this framework using the randomized range finding techniques. The resulting HSFEM involves two stages and suits the multi-query setting: in the offline stage, the local stochastic structure of the solution space is identified; in the online stage, the equation can be efficiently solved for multiple forcing functions. An online error estimation and correction procedure through Monte Carlo sampling is given. Numerical results for several problems with high dimensional stochastic input are presented to demonstrate the efficiency of the HSFEM in the online stage

Evolving stochastic context-free grammars for RNA secondary structure prediction

DEFF Research Database (Denmark)

Anderson, James WJ; Tataru, Paula Cristina; Stains, Joe

2012-01-01

Background Stochastic Context-Free Grammars (SCFGs) were applied successfully to RNA secondary structure prediction in the early 90s, and used in combination with comparative methods in the late 90s. The set of SCFGs potentially useful for RNA secondary structure prediction is very large, but a few...... to structure prediction as has been previously suggested. Results These search techniques were applied to predict RNA secondary structure on a maximal data set and revealed new and interesting grammars, though none are dramatically better than classic grammars. In general, results showed that many grammars...... with quite different structure could have very similar predictive ability. Many ambiguous grammars were found which were at least as effective as the best current unambiguous grammars. Conclusions Overall the method of evolving SCFGs for RNA secondary structure prediction proved effective in finding many...

Assessment of rock mass characteristics and the excavation disturbed zone in the Lingxin Coal Mine beneath the Xitian river, China

International Nuclear Information System (INIS)

Xingping Lai

2006-01-01

Safe production and induced hazard prevention in coal mines mainly concern problems in the excavation disturbed zone (EDZ), but coal mining can also make a significant impact on the environment. Comprehensive techniques using a borehole TV viewer system, electrical logging, and monitoring of drilling fluid leakage offer the ability to identify changing geological conditions and the location of any nearby abandoned mining workings. The inner collapsed zone and the expanding height of the crack zone transmitting water plus their spatial distribution after excavating the superincumbent coal seam stratum are determined at no. L3414 workings, Lingxin Coal Mine beneath the Xitian river, China. An integrated system of GIS-based on a stochastic model, which has been developed for the prediction of dynamic subsidence coupling the time function and probabilistic integral method, is verified through practice at the Lingxin Coal Mine. This development has greatly expanded the ability of the mine operator to characterize previously inaccessible areas of the mine, providing a reliable basis for safe mining and prevention of induced-hazards to ensure high production mining underneath the river bed. (author)

Greenhouse Gas Emissions from Excavation on Residential Construction Sites

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Perry Forsythe

2014-12-01

Full Text Available Despite considerable research concerning the manifestation of greenhouse gases in the usage of buildings, little has been done concerning emissions arising from the construction process itself. This paper specifically examines emissions arising from cut and fill excavation on residential construction sites. Even though such excavation is often seen as being economical in terms of providing a flat base for concrete raft slab construction, the environmental consequences of this approach need to be considered more fully in terms of impact on the environment. This is particularly important when steeply sloping sites are involved and for different soil types. The paper undertakes a study that quantitatively assesses the cumulative greenhouse gas emissions caused by cut and fill excavation on 52 residential projects in Australia for a range of slope and soil types. The paper presents results from the study and concludes that greenhouse gas emissions increase as site slope increases; the building footprint area (as distinct from Gross Floor Area, exposes the need to reduce the area of the building to reduce greenhouse gas emissions; excavation of rock soils creates higher emissions than other soil types; and cut and fill excavation on steeply slope sites increase emissions. Potential alternative construction includes suspended floor construction systems which involve less excavation.

Greenhouse Gas Emissions from Excavation on Residential Construction Sites

Directory of Open Access Journals (Sweden)

Perry Forsythe

2014-12-01

Full Text Available Despite considerable research concerning the manifestation of greenhouse gases in the usage of buildings, little has been done concerning emissions arising from the construction process itself. This paper specifically examines emissions arising from cut and fill excavation on residential construction sites. Even though such excavation is often seen as being economical in terms of providing a flat base for concrete raft slab construction, the environmental consequences of this approach need to be considered more fully in terms of impact on the environment. This is particularly important when steeply sloping sites are involved and for different soil types. The paper undertakes a study that quantitatively assesses the cumulative greenhouse gas emissions caused by cut and fill excavation on 52 residential projects in Australia for a range of slope and soil types. The paper presents results from the study and concludes that greenhouse gas emissions increase as site slope increases; the building footprint area (as distinct from Gross Floor Area, exposes the need to reduce the area of the building to reduce greenhouse gas emissions; excavation of rock soils creates higher emissions than other soil types; and cut and fill excavation on steeply slope sites increase emissions. Potential alternative construction includes suspended floor construction systems which involve less excavation. 

Mechanical excavator performance in Yucca Mountain tuffs

International Nuclear Information System (INIS)

Ozdemir, L.; Hansen, F.D.

1991-01-01

A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests and potentially large-scale laboratory demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs. 3 refs., 2 tabs

Mechanical excavator performance in Yucca Mountain tuffs

International Nuclear Information System (INIS)

Ozdemir, L.; Hansen, F.D.

1991-01-01

A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests, and potentially large-scale lab. demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well-quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs

Dynamic and Stochastic Structures of U.S. Cotton Exports and Mill Demand

OpenAIRE

Fadiga, Mohamadou L.

2006-01-01

This study employs a structural time-series method to model and estimate U.S. cotton exports and mill use. The results show that the stochastic process governing cotton export fluctuations is transitory, while the process pertaining to mill use has transitory, seasonal, and secular origins. The estimated structural relationships after accounting for the unobserved components indicate U.S. cotton exports respond directly to higher international price relative to domestic price of cotton, while...

Stochastic search in structural optimization - Genetic algorithms and simulated annealing

Science.gov (United States)

Hajela, Prabhat

1993-01-01

An account is given of illustrative applications of genetic algorithms and simulated annealing methods in structural optimization. The advantages of such stochastic search methods over traditional mathematical programming strategies are emphasized; it is noted that these methods offer a significantly higher probability of locating the global optimum in a multimodal design space. Both genetic-search and simulated annealing can be effectively used in problems with a mix of continuous, discrete, and integer design variables.

Stochastic structure of annual discharges of large European rivers

Directory of Open Access Journals (Sweden)

Stojković Milan

2015-03-01

Full Text Available Water resource has become a guarantee for sustainable development on both local and global scales. Exploiting water resources involves development of hydrological models for water management planning. In this paper we present a new stochastic model for generation of mean annul flows. The model is based on historical characteristics of time series of annual flows and consists of the trend component, long-term periodic component and stochastic component. The rest of specified components are model errors which are represented as a random time series. The random time series is generated by the single bootstrap model (SBM. Stochastic ensemble of error terms at the single hydrological station is formed using the SBM method. The ultimate stochastic model gives solutions of annual flows and presents a useful tool for integrated river basin planning and water management studies. The model is applied for ten large European rivers with long observed period. Validation of model results suggests that the stochastic flows simulated by the model can be used for hydrological simulations in river basins.

Stability calculation method of slope reinforced by prestressed anchor in process of excavation.

Science.gov (United States)

Li, Zhong; Wei, Jia; Yang, Jun

2014-01-01

This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tension of the whole process is also given out, through which the real-time analysis and checking of slope stability in the process of excavation can be realized. The calculation examples indicate that the slope stability is changed with the dynamic change of the design parameters of anchor and grillage beam. So it is relatively more accurate and reasonable by using dynamic search model to determine the critical slip surface of the slope reinforced by prestressed anchor and grillage beam. Through the relationships of each anchor layout and the slope height of various stages of excavation, and the optimal stability solution of prestressed bolt tension design value in various excavation stages can be obtained. The arrangement of its prestressed anchor force reflects that the layout of the lower part of bolt and the calculation of slope reinforcement is in line with the actual. These indicate that the method is reasonable and practical.

Stochastic volatility and stochastic leverage

DEFF Research Database (Denmark)

Veraart, Almut; Veraart, Luitgard A. M.

This paper proposes the new concept of stochastic leverage in stochastic volatility models. Stochastic leverage refers to a stochastic process which replaces the classical constant correlation parameter between the asset return and the stochastic volatility process. We provide a systematic...... treatment of stochastic leverage and propose to model the stochastic leverage effect explicitly, e.g. by means of a linear transformation of a Jacobi process. Such models are both analytically tractable and allow for a direct economic interpretation. In particular, we propose two new stochastic volatility...... models which allow for a stochastic leverage effect: the generalised Heston model and the generalised Barndorff-Nielsen & Shephard model. We investigate the impact of a stochastic leverage effect in the risk neutral world by focusing on implied volatilities generated by option prices derived from our new...

Causal feedforward control of a stochastically excited fuselage structure with active sidewall panel.

Science.gov (United States)

Misol, Malte; Haase, Thomas; Monner, Hans Peter; Sinapius, Michael

2014-10-01

This paper provides experimental results of an aircraft-relevant double panel structure mounted in a sound transmission loss facility. The primary structure of the double panel system is excited either by a stochastic point force or by a diffuse sound field synthesized in the reverberation room of the transmission loss facility. The secondary structure, which is connected to the frames of the primary structure, is augmented by actuators and sensors implementing an active feedforward control system. Special emphasis is placed on the causality of the active feedforward control system and its implications on the disturbance rejection at the error sensors. The coherence of the sensor signals is analyzed for the two different disturbance excitations. Experimental results are presented regarding the causality, coherence, and disturbance rejection of the active feedforward control system. Furthermore, the sound transmission loss of the double panel system is evaluated for different configurations of the active system. A principal result of this work is the evidence that it is possible to strongly influence the transmission of stochastic disturbance sources through double panel configurations by means of an active feedforward control system.

Remotely operated excavator needs assessment/site visit summary

Energy Technology Data Exchange (ETDEWEB)

Straub, J.; Haller, S.; Worsley, R. [Westinghouse Environmental Management Co. of Ohio, Cincinnati, OH (United States); King, M. [THETA Technology Inc. (United States)

1992-12-02

The Uranium in Soils Integrated Demonstration requested an assessment of soil excavation needs relative to soil remediation. The following list identifies the DOE sites assessed: Mound Laboratory, Paducah Gaseous Diffusion Plant, Portsmouth Gaseous Diffusion Plant, Nevada Test Site, Lawrence Livermore National Laboratory, Rocky Flats Plant, Los Alamos National Laboratory, Sandia National Laboratory, Idaho National Engineering Laboratory, Hanford Site, and Fernald Site. The reviewed sites fall into one or more of the following three categories: production, EPA National Priorities List, or CERCLA (superfund) designation. Only three of the sites appear to have the need for a remotely operated excavator rope. Hanford and Idaho Falls have areas of high-level radioactive contamination either buried or in/under buildings. The Fernald site has a need for remote operated equipment of different types. It is their feeling that remote equipment can be used to remove the health dangers to humans by removing them from the area. Most interviewees stated that characterization technologies needs are more immediate concern over excavation. In addition, the sites do not have similar geographic conditions which would aid in the development of a generic precision excavator. The sites visited were not ready to utilize or provide the required design information necessary to draft a performance specification. This creates a strong case against the development of one type of ROPE for use at these sites. Assuming soil characterization technology/methodology is improved sufficiently to allow accurate and real time field characterization then development of a precision excavator might be pursued based on FEMP needs, since the FEMP`s sole scope of work is remediation. The excavator could then be used/tested and then later modified for other sites as warranted.

Sequential neural models with stochastic layers

DEFF Research Database (Denmark)

Fraccaro, Marco; Sønderby, Søren Kaae; Paquet, Ulrich

2016-01-01

How can we efficiently propagate uncertainty in a latent state representation with recurrent neural networks? This paper introduces stochastic recurrent neural networks which glue a deterministic recurrent neural network and a state space model together to form a stochastic and sequential neural...... generative model. The clear separation of deterministic and stochastic layers allows a structured variational inference network to track the factorization of the model's posterior distribution. By retaining both the nonlinear recursive structure of a recurrent neural network and averaging over...

Stochastic Pi-calculus Revisited

DEFF Research Database (Denmark)

Cardelli, Luca; Mardare, Radu Iulian

2013-01-01

We develop a version of stochastic Pi-calculus with a semantics based on measure theory. We dene the behaviour of a process in a rate environment using measures over the measurable space of processes induced by structural congruence. We extend the stochastic bisimulation to include the concept of...

Excavation of LSS1

CERN Multimedia

CERN PhotoLab

1972-01-01

Excavation of the long straight-section LSS1 by an Alpine boring machine. View of the connection chamber, in the background, the roofs of the enlarged sections (8.5 m and 6 m). On the right, the access tunnel to PP1.

Stochastic Optimization of Wind Turbine Power Factor Using Stochastic Model of Wind Power

DEFF Research Database (Denmark)

Chen, Peiyuan; Siano, Pierluigi; Bak-Jensen, Birgitte

2010-01-01

This paper proposes a stochastic optimization algorithm that aims to minimize the expectation of the system power losses by controlling wind turbine (WT) power factors. This objective of the optimization is subject to the probability constraints of bus voltage and line current requirements....... The optimization algorithm utilizes the stochastic models of wind power generation (WPG) and load demand to take into account their stochastic variation. The stochastic model of WPG is developed on the basis of a limited autoregressive integrated moving average (LARIMA) model by introducing a crosscorrelation...... structure to the LARIMA model. The proposed stochastic optimization is carried out on a 69-bus distribution system. Simulation results confirm that, under various combinations of WPG and load demand, the system power losses are considerably reduced with the optimal setting of WT power factor as compared...

Excavating the Spartans

Directory of Open Access Journals (Sweden)

John Wilkes

1997-11-01

Full Text Available Few ancient Greek place names are so embedded in Western consciousness as Sparta, evoking as it does courage, harsh training, stern duty and endurance. By the 2nd century AD it had become a "heritage centre " admired by visiting Romans, and it flourished again in the Byzantine period. The Institute has been involved in new excavations at Sparta since 1989.

Fundamentals of stochastic nature sciences

CERN Document Server

Klyatskin, Valery I

2017-01-01

This book addresses the processes of stochastic structure formation in two-dimensional geophysical fluid dynamics based on statistical analysis of Gaussian random fields, as well as stochastic structure formation in dynamic systems with parametric excitation of positive random fields f(r,t) described by partial differential equations. Further, the book considers two examples of stochastic structure formation in dynamic systems with parametric excitation in the presence of Gaussian pumping. In dynamic systems with parametric excitation in space and time, this type of structure formation either happens – or doesn’t! However, if it occurs in space, then this almost always happens (exponentially quickly) in individual realizations with a unit probability. In the case considered, clustering of the field f(r,t) of any nature is a general feature of dynamic fields, and one may claim that structure formation is the Law of Nature for arbitrary random fields of such type. The study clarifies the conditions under wh...

Stochastic Still Water Response Model

DEFF Research Database (Denmark)

Friis-Hansen, Peter; Ditlevsen, Ove Dalager

2002-01-01

In this study a stochastic field model for the still water loading is formulated where the statistics (mean value, standard deviation, and correlation) of the sectional forces are obtained by integration of the load field over the relevant part of the ship structure. The objective of the model is...... out that an important parameter of the stochastic cargo field model is the mean number of containers delivered by each customer.......In this study a stochastic field model for the still water loading is formulated where the statistics (mean value, standard deviation, and correlation) of the sectional forces are obtained by integration of the load field over the relevant part of the ship structure. The objective of the model...... is to establish the stochastic load field conditional on a given draft and trim of the vessel. The model contributes to a realistic modelling of the stochastic load processes to be used in a reliability evaluation of the ship hull. Emphasis is given to container vessels. The formulation of the model for obtaining...

Stochastic demography and the neutral substitution rate in class-structured populations.

Science.gov (United States)

Lehmann, Laurent

2014-05-01

The neutral rate of allelic substitution is analyzed for a class-structured population subject to a stationary stochastic demographic process. The substitution rate is shown to be generally equal to the effective mutation rate, and under overlapping generations it can be expressed as the effective mutation rate in newborns when measured in units of average generation time. With uniform mutation rate across classes the substitution rate reduces to the mutation rate.

Telerobotic Excavator Designed to Compete in NASA's Lunabotics Mining Competition

Science.gov (United States)

Nash, Rodney; Santin, Cara; Yousef, Ahmed; Nguyen, Thien; Helferty, John; Pillapakkam, Shriram

2011-01-01

The second annual NASA Lunabotics Mining competition is to be held in May 23-28, 2011. The goal of the competition is for teams of university level students to design, build, test and compete with a fully integrated lunar excavator on a simulated lunar surface. Our team, named Lunar Solutions I, will be representing Temple University's College of Engineering in the competition. The team's main goal was to build a robot which is able to compete with other teams, and ultimately win the competition. The main challenge of the competition was to build a wireless robot that can excavate and collect a minimum of 10 kilograms of the regolith material within 15 minutes. The robot must also be designed to operate in conditions similar to those found on the lunar surface. The design of the lunar excavator is constrained by a set of requirements determined by NASA and detailed in the competition's rulebook. The excavator must have the ability to communicate with the "main base" wirelessly, and over a Wi-Fi network. Human operators are located at a remote site approximately 60 meters away from the simulated lunar surface upon which the robot must excavate the lunar regolith surface. During the competition, the robot will operate in a separate area from the control room in an area referred to as the "Lunarena." From the control room, the operators will have to control the robot using visual feedback from cameras placed both within the arena and on the robot. Using this visual feedback the human operators control the robots movement using both keyboard and joystick commands. In order to place in the competition, a minimum of 10 kg of regolith material has to be excavated, collected, and dumped into a specific location. For that reason, the robot must be provided with an effective and powerful excavation system. Our excavator uses tracks for the drive system. After performing extensive research and trade studies, we concluded that tracks would be the most effective method for

Identification of the structure parameters using short-time non-stationary stochastic excitation

Science.gov (United States)

Jarczewska, Kamila; Koszela, Piotr; Śniady, PaweŁ; Korzec, Aleksandra

2011-07-01

In this paper, we propose an approach to the flexural stiffness or eigenvalue frequency identification of a linear structure using a non-stationary stochastic excitation process. The idea of the proposed approach lies within time domain input-output methods. The proposed method is based on transforming the dynamical problem into a static one by integrating the input and the output signals. The output signal is the structure reaction, i.e. structure displacements due to the short-time, irregular load of random type. The systems with single and multiple degrees of freedom, as well as continuous systems are considered.

Use of chemical explosives for emergency solar flare shelter construction and other excavations on the Martian surface

International Nuclear Information System (INIS)

Dick, R.D.; Blacic, J.D.; Pettitt, D.R.

1985-01-01

The necessity to shelter people on the Martian surface from solar flare particles at short notice and the need for long-term habitats with thick cosmic ray shielding suggests that explosives could be used effectively for excavation of such structures. Modern insensitive high explosives are safe, efficient, and reliable for rock breakage and excavation. Extensive Earth-bound experience leads us to propose several strategies for explosively-constructed shelters based on tunneling, cratering, and rock casting techniques

Determination of near field excavation disturbance in crystalline rock

International Nuclear Information System (INIS)

Koopmans, R.; Hughes, R.W.

1986-01-01

The computerized dilatometer system has rapidly and economically provided deformation moduli of low and high modulus rock, determined the extent of excavation disturbance surrounding an underground opening and located open fracture within a rock mass. Results from both test sites indicate that the moduli obtained were influenced by the in situ tangential stress field. It has been shown that the near field excavation disturbance is kept to a minimum through the use of careful excavation techniques such as the tunnel boring machine. In turn, the in situ tangential stress levels and deformation moduli are maximized while the corresponding permeability is minimized

Archaeological Excavation and Deep Mapping in Historic Rural Communities

Directory of Open Access Journals (Sweden)

Carenza Lewis

2015-09-01

Full Text Available This paper reviews the results of more than a hundred small archaeological “test pit” excavations carried out in 2013 within four rural communities in eastern England. Each excavation used standardized protocols in a different location within the host village, with the finds dated and mapped to create a series of maps spanning more than 3500 years, in order to advance understanding of the spatial development of settlements and landscapes over time. The excavations were all carried out by local volunteers working physically within their own communities, supported and advised by professional archaeologists, with most test pits sited in volunteers’ own gardens or those of their friends, family or neighbors. Site-by-site, the results provided glimpses of the use made by humans of each of the excavated sites spanning prehistory to the present day; while in aggregate the mapped data show how settlement and land-use developed and changed over time. Feedback from participants also demonstrates the diverse positive impacts the project had on individuals and communities. The results are presented and reviewed here in order to highlight the contribution archaeological test pit excavation can make to deep mapping, and the contribution that deep mapping can make to rural communities.

Dynamic analysis and reliability assessment of structures with uncertain-but-bounded parameters under stochastic process excitations

International Nuclear Information System (INIS)

Do, Duy Minh; Gao, Wei; Song, Chongmin; Tangaramvong, Sawekchai

2014-01-01

This paper presents the non-deterministic dynamic analysis and reliability assessment of structures with uncertain-but-bounded parameters under stochastic process excitations. Random ground acceleration from earthquake motion is adopted to illustrate the stochastic process force. The exact change ranges of natural frequencies, random vibration displacement and stress responses of structures are investigated under the interval analysis framework. Formulations for structural reliability are developed considering the safe boundary and structural random vibration responses as interval parameters. An improved particle swarm optimization algorithm, namely randomised lower sequence initialized high-order nonlinear particle swarm optimization algorithm, is employed to capture the better bounds of structural dynamic characteristics, random vibration responses and reliability. Three numerical examples are used to demonstrate the presented method for interval random vibration analysis and reliability assessment of structures. The accuracy of the results obtained by the presented method is verified by the randomised Quasi-Monte Carlo simulation method (QMCSM) and direct Monte Carlo simulation method (MCSM). - Highlights: • Interval uncertainty is introduced into structural random vibration responses. • Interval dynamic reliability assessments of structures are implemented. • Boundaries of structural dynamic response and reliability are achieved

BILATERAL CHOROIDAL EXCAVATION IN JUVENILE LOCALIZED SCLERODERMA.

Science.gov (United States)

Franklin, Mackenzie L; Day, Shelley

2018-01-01

To describe a case of bilateral choroidal excavation in a patient with juvenile localized scleroderma. Case report. An asymptomatic 12-year-old boy with localized scleroderma presented for examination and was found to have bilateral areas of choroidal excavation temporal to the fovea. Previous reports of ocular complications of localized scleroderma have primarily described adnexal and anterior segment changes. This is the second report of choroidal changes in a patient with localized scleroderma, and the first in a pediatric patient.

A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study.

Science.gov (United States)

Hassan, Afrah Fatima; Yadav, Gunjan; Tripathi, Abhay Mani; Mehrotra, Mridul; Saha, Sonali; Garg, Nishita

2016-01-01

Caries excavation is a noninvasive technique of caries removal with maximum preservation of healthy tooth structure. To compare the efficacy of three different caries excavation techniques in reducing the count of cariogenic flora. Sixty healthy primary molars were selected from 26 healthy children with occlusal carious lesions without pulpal involvement and divided into three groups in which caries excavation was done with the help of (1) carbide bur; (2) polymer bur using slow-speed handpiece; and (3) ultrasonic tip with ultrasonic machine. Samples were collected before and after caries excavation for microbiological analysis with the help of sterile sharp spoon excavator. Samples were inoculated on blood agar plate and incubated at 37°C for 48 hours. After bacterial cultivation, the bacterial count of Streptococcus mutans was obtained. All statistical analysis was performed using SPSS 13 statistical software version. Kruskal-Wallis analysis of variance, Wilcoxon matched pairs test, and Z test were performed to reveal the statistical significance. The decrease in bacterial count of S. mutans before and after caries excavation was significant (p flora, while ultrasonic tip showed almost comparable results, while polymer bur showed least reduction in cariogenic flora after caries excavation. Hassan AF, Yadav G, Tripathi AM, Mehrotra M, Saha S, Garg N. A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study. Int J Clin Pediatr Dent 2016;9(3):214-217.

MATHEMATICAL MODEL OF ATTITUDE CONTROL BUCKET‐WHEEL EXCAVATOR

Directory of Open Access Journals (Sweden)

Ivana ONDERKOVÁ

2013-07-01

Full Text Available This lecture deals with the application problems of convertibility GPS system at paddle excavator K 800. The claims of the modern operating surface mining of the excavators requires a lot of information for monitoring of mining process, capacity mining, selective extraction etc. The utilization of monitoring the excavator setting by GPS system proved to be the only one proper because the receivers are resistant to the vibration, dust, temperature divergence and weather changeable. Only the direct contact with communications satellite is required. It means that they can´t be located in a metal construction space (shadow caused by construction elements, influence of electrical high voltage cables even they can´t be located close to the paddle wheel on the paddle boom (shadow possibility caused by cuttinng edge created during lower gangplanks mining. This is the reason that GPS receivers are set uppermost on the metal construction excavator and the mathematical formulation is required for determination of paddle wheel petting. The relations for calculation of the paddle wheel coordinate were defined mathematically and after that the mathematical model was composed.

Design and construction of earth retaining walls with anchors employed in excavation works at Oi Nuclear Power Plant

International Nuclear Information System (INIS)

Saino, Susumu; Aoshima, Ken-ichiro; Kamide, Atsushi.

1990-01-01

In Oi Nuclear Power Station, Kansai Electric Power Co., Inc., No.3 and No.4 plants of each 1180 MWe output are additionally installed, neighboring existing No.1 and No.2 plants of each 1175 MWe output in operation. The start of operation is expected in December, 1991 in No.3 plant, and in February, 1993 in No.4 plant. The total quantity of earth excavated for this additional installation works is about 3.3 million m 3 . The main works are, subsequently to the preparation of the site, the excavation for the foundations of reactor buildings and others, and the construction of the foundations for the seawater system facilities for cooling condensers and reactor auxiliary machines, and the works were begun in May, 1987. The excavation by using anchors was carried out in seven places. The vertical excavation on large scale was carried out by using the earth retaining walls of concrete-sprayed anchor structure in drain pits. In this report, the outline of the geological features, the outline of the excavation works, the design of the earth retaining walls, the execution of concrete spraying, the planning and result of measurement are described. (K.I.)

Utilization of thin-layer chromatography for confirmational sampling during remedial excavation

International Nuclear Information System (INIS)

Burton, P.J.

1996-01-01

Thin-layer chromatography (TLC) is a simple, efficient, inexpensive, and accurate method of chemical analysis. This method is applicable to field testing for confirming the limits of excavation during excavation of petroleum, oil, and/or lubricant (POL) contamination. Traditionally, excavation at contaminated sites suffers from a time delay due to the need to obtain laboratory confirmation of the limits of excavation. All suspected contaminated material is removed for stockpiling or remediation. The remaining soils need to be sampled to confirm that no contaminated material remains in the excavation. The site scientist collects samples and sends them out for analysis at a certified laboratory. The laboratory requires, even for a rush order, several days to analyze the samples. This time delay interferes with the efficiency of the operation. The excavations either have to be left open (which is a safety hazard) or reopened if additional material must be excavated. TLC samples can be collected and analyzed in several hours allowing for a short turnaround time for analytical results. The TLC method can be easily performed by a technician. Results of a case study from a subarctic Alaskan site will be reported. Simple operational TLC procedures will be shared. The equipment required for TLC analysis will be outlined. Correlation data between TLC and laboratory analysis will be presented

Stochastic generation of explicit pore structures by thresholding Gaussian random fields

Energy Technology Data Exchange (ETDEWEB)

Hyman, Jeffrey D., E-mail: jhyman@lanl.gov [Program in Applied Mathematics, University of Arizona, Tucson, AZ 85721-0089 (United States); Computational Earth Science, Earth and Environmental Sciences (EES-16), and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Winter, C. Larrabee, E-mail: winter@email.arizona.edu [Program in Applied Mathematics, University of Arizona, Tucson, AZ 85721-0089 (United States); Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ 85721-0011 (United States)

2014-11-15

We provide a description and computational investigation of an efficient method to stochastically generate realistic pore structures. Smolarkiewicz and Winter introduced this specific method in pores resolving simulation of Darcy flows (Smolarkiewicz and Winter, 2010 [1]) without giving a complete formal description or analysis of the method, or indicating how to control the parameterization of the ensemble. We address both issues in this paper. The method consists of two steps. First, a realization of a correlated Gaussian field, or topography, is produced by convolving a prescribed kernel with an initial field of independent, identically distributed random variables. The intrinsic length scales of the kernel determine the correlation structure of the topography. Next, a sample pore space is generated by applying a level threshold to the Gaussian field realization: points are assigned to the void phase or the solid phase depending on whether the topography over them is above or below the threshold. Hence, the topology and geometry of the pore space depend on the form of the kernel and the level threshold. Manipulating these two user prescribed quantities allows good control of pore space observables, in particular the Minkowski functionals. Extensions of the method to generate media with multiple pore structures and preferential flow directions are also discussed. To demonstrate its usefulness, the method is used to generate a pore space with physical and hydrological properties similar to a sample of Berea sandstone. -- Graphical abstract: -- Highlights: •An efficient method to stochastically generate realistic pore structures is provided. •Samples are generated by applying a level threshold to a Gaussian field realization. •Two user prescribed quantities determine the topology and geometry of the pore space. •Multiple pore structures and preferential flow directions can be produced. •A pore space based on Berea sandstone is generated.

Rock samples from LEP/LHC tunnel excavation

CERN Multimedia

1985-01-01

Rock samples taken from 0 to 170 m below ground on the CERN site when the LEP (Large Electron Positron collider) pit number 6 was drilled in Bois-chatton (Versonnex). The challenges of LHC civil engineering: A mosaic of works, structures and workers of differents crafts and origins. Three consulting consortia for the engineering and the follow-up of the works. Four industrial consortia for doing the job. A young team of 25 CERN staff, 30 surface buildings, 32 caverns of all sizes, 170 000 m3 of concrete, 420 000 m3 excavated. 1998-2004 : six years of work and 340 millions Swiss Francs.

Combining a popularity-productivity stochastic block model with a discriminative-content model for general structure detection.

Science.gov (United States)

Chai, Bian-fang; Yu, Jian; Jia, Cai-Yan; Yang, Tian-bao; Jiang, Ya-wen

2013-07-01

Latent community discovery that combines links and contents of a text-associated network has drawn more attention with the advance of social media. Most of the previous studies aim at detecting densely connected communities and are not able to identify general structures, e.g., bipartite structure. Several variants based on the stochastic block model are more flexible for exploring general structures by introducing link probabilities between communities. However, these variants cannot identify the degree distributions of real networks due to a lack of modeling of the differences among nodes, and they are not suitable for discovering communities in text-associated networks because they ignore the contents of nodes. In this paper, we propose a popularity-productivity stochastic block (PPSB) model by introducing two random variables, popularity and productivity, to model the differences among nodes in receiving links and producing links, respectively. This model has the flexibility of existing stochastic block models in discovering general community structures and inherits the richness of previous models that also exploit popularity and productivity in modeling the real scale-free networks with power law degree distributions. To incorporate the contents in text-associated networks, we propose a combined model which combines the PPSB model with a discriminative model that models the community memberships of nodes by their contents. We then develop expectation-maximization (EM) algorithms to infer the parameters in the two models. Experiments on synthetic and real networks have demonstrated that the proposed models can yield better performances than previous models, especially on networks with general structures.

Heathrow Terminal 5 Excavation Archive (Data Paper

Directory of Open Access Journals (Sweden)

Framework Archaeology

2014-06-01

Full Text Available Framework Archaeology is a Joint Venture agreement between Oxford Archaeology (OA and Wessex Archaeology (WA to provide archaeological services to BAA (formerly British Airports Authority, now Heathrow Airport Holdings Ltd. Given the potential scale of some of BAA's projects, the joint venture enables Framework Archaeology to draw on the full resources of both OA and WA, including site staff, specialist managers, administrative support, and technical facilities. In 1993, BAA plc and Heathrow Airport Limited submitted a joint planning application to develop an additional passenger terminal complex (Terminal 5, together with the provision of aircraft aprons and taxiways, and include the realignment of rivers and landscaping. The resulting archaeological excavations were undertaken as three main phases of work. Excavations in 1996 by the Museum of London Archaeology Service of approximately 4 ha of sludge stockpile areas (site code POK96. Between 1999-2000 Framework Archaeology excavated approximately 21 ha in the Perry Oaks sludge works and adjacent areas (WPR98. Framework Archaeology also undertook excavations between 2002-2007 as part of the construction of Terminal 5 (PSH02, TEC05 covering a further 50 hectares. Importantly the aim of the Terminal 5 archaeological programme was to move beyond the description and recovery of archaeological remains and to arrive at an understanding of the history of human inhabitation and the practical ways in which people established their presence in the material, social and political conditions of their day.

Application of full-face round by the sequential blasting machine in tunnel excavation

Energy Technology Data Exchange (ETDEWEB)

Cho, Y.D.; Park, B.K.; Lee, S.E.; Lim, H.U.

1995-12-31

Many methods and techniques have been developed to reduce ground vibrations. Some of them are an adoption of electric millisecond detonators with a sequential blasting machine and an improvement of initiating system with an adequate number of delay intervals. To reduce the level of ground vibration in tunnel excavation, the sequential blasting machine (S.B.M.) with decisecond detonators was adopted. A total of 134 blasts was recorded at various sites and the results were analyzed. The distances blast-to-structures were ranged from 20.3 to 42.0 meter, where charge weights were varied from 0.25 to 0.75kg per delay. It is proved that the sequential blasting in tunnel excavation is very effective to control ground vibration.

Determining the productivity of frontal-selective excavation equipment

Energy Technology Data Exchange (ETDEWEB)

Baikenzhin, A E; Ermekov, T E

1979-01-01

The engineering parameters of the VMF-2 frontal-selective excavation machine are given. Calculation formulae are given for determining the feed speed of the working tool relative to the difference in the motion of the arm of the working tool and the feed speed of the hydraulic jack lifter. A methodology is developed for calculating the productivity of the excavator depending on various engineering conditions, accounting for modifications in its design.

Pajarito Plateau archaeological surveys and excavations. II

Energy Technology Data Exchange (ETDEWEB)

Steen, C R

1982-04-01

Los Alamos National Laboratory continues its archaeological program of data gathering and salvage excavations. Sites recently added to the archaeological survey are described, as well as the results of five excavations. Among the more interesting and important discoveries are (1) the apparently well-established local use of anhydrous lime, and (2) a late pre-Columbian use of earlier house sites and middens for garden plots. Evidence indicated that the local puebloan population was the result of an expansion of upper Rio Grande peoples, not an influx of migrants.

Room 209 excavation response test in the underground research laboratory

International Nuclear Information System (INIS)

Lang, P.A.

1989-01-01

An in situ excavation response test was conducted at the Canadian Underground Research Laboratory (URL) in conjunction with excavation of a tunnel (Room 209) through a near-vertical water-bearing fracture oriented perpendicular to the tunnel axis. Encountering a fracture with such desirable characteristics provided a unique opportunity during construction of the URL to try out instrumentation and analytical methods for use in the Excavation Response Experiment (ERE) planned as one of the major URL experiments. The test has produced a valuable data set for validating numerical models. Four modelling groups predicted the response that would be monitored by the instruments. The predictions of the mechanical response were generally good. However, the predictions of the permeability and hydraulic pressure changes in the fracture, and the water flows into the tunnel, were poor. It is concluded that we may not understand the mechanisms that occur in the fracture in response to excavation. Laboratory testing, and development of a contracting joint code, has been initiated to further investigate this phenomenon. Preliminary results indicate that the excavation damaged zone in the walls and crown is less than 0.5 m thick and has relatively low permeability. The damaged zone in the floor is at least 1 m thick and has relatively high permeability. The damage in the floor could be reduced in future excavations by using controlled blasting methods similar to those used for the walls and crown

A study experiment of auto idle application in the excavator engine performance

Energy Technology Data Exchange (ETDEWEB)

Purwanto, Wawan, E-mail: wawan5527@gmail.com; Maksum, Hasan; Putra, Dwi Sudarno, E-mail: dwisudarnoputra@ft.unp.ac.id; Wahyudi, Retno [State University of Padang, West Sumatera (Indonesia); Azmi, Meri, E-mail: meriazmi@gmail.com [State Polytechnic of Padang, West Sumatera (Indonesia)

2016-03-29

The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

Astrophysical disks Collective and Stochastic Phenomena

CERN Document Server

Fridman, Alexei M; Kovalenko, Ilya G

2006-01-01

The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

Excavated rock materials from tunnels for sprayed concrete

OpenAIRE

Luong, Judy Yuen Wah; Aarstad, Kari; De Weerdt, Klaartje; Bjøntegaard, Øyvind

2017-01-01

Sand extracted from natural resources is widely used in concrete production nowadays. The increase in demand for concrete production has resulted in shortage of natural sand resources, especially in terms of suitable materials for concrete production. At the same time, large amounts of excavated rock materials are and have been generated from tunnelling projects and discarded. Hence, there is an opportunity to use these excavated rock materials as aggregates for concrete production. The chall...

Evaluation of structural behavior, geological and hydrogeological characteristics

International Nuclear Information System (INIS)

Kim, Jhin Wung; Kim, Sun Hoon; Kim, Dae Hong; Choi, Kyu Sup

1992-02-01

In order to understand the behavior of an underground structure properly, this report includes the study on the structural behavior of rock masses surrounding underground openings considering the effect of excavation. Before analyzing the underground structure, the followings are studied: initial stress distribution before excavation, stress release and redistribution due to the sequential excavation, comparison of analysis methods, discussions on numerical simulation techniques for the sequential excavation and an numerical analysis modeling. The underground structure in then analyzed using the finite element and distinct element methods of analysis considering the effect of sequential excavation, Based on the results of the analysis, the followings are discussed: shape of the opening, distance between openings, method and sequence of excavation, and structural reinforcement. (Author)

Random function representation of stationary stochastic vector processes for probability density evolution analysis of wind-induced structures

Science.gov (United States)

Liu, Zhangjun; Liu, Zenghui

2018-06-01

This paper develops a hybrid approach of spectral representation and random function for simulating stationary stochastic vector processes. In the proposed approach, the high-dimensional random variables, included in the original spectral representation (OSR) formula, could be effectively reduced to only two elementary random variables by introducing the random functions that serve as random constraints. Based on this, a satisfactory simulation accuracy can be guaranteed by selecting a small representative point set of the elementary random variables. The probability information of the stochastic excitations can be fully emerged through just several hundred of sample functions generated by the proposed approach. Therefore, combined with the probability density evolution method (PDEM), it could be able to implement dynamic response analysis and reliability assessment of engineering structures. For illustrative purposes, a stochastic turbulence wind velocity field acting on a frame-shear-wall structure is simulated by constructing three types of random functions to demonstrate the accuracy and efficiency of the proposed approach. Careful and in-depth studies concerning the probability density evolution analysis of the wind-induced structure have been conducted so as to better illustrate the application prospects of the proposed approach. Numerical examples also show that the proposed approach possesses a good robustness.

SLOPE STABILITY EVALUATION AND EQUIPMENT SETBACK DISTANCES FOR BURIAL GROUND EXCAVATIONS

Energy Technology Data Exchange (ETDEWEB)

MCSHANE DS

2010-03-25

After 1970 Transuranic (TRU) and suspect TRU waste was buried in the ground with the intention that at some later date the waste would be retrieved and processed into a configuration for long term storage. To retrieve this waste the soil must be removed (excavated). Sloping the bank of the excavation is the method used to keep the excavation from collapsing and to provide protection for workers retrieving the waste. The purpose of this paper is to document the minimum distance (setback) that equipment must stay from the edge of the excavation to maintain a stable slope. This evaluation examines the equipment setback distance by dividing the equipment into two categories, (1) equipment used for excavation and (2) equipment used for retrieval. The section on excavation equipment will also discuss techniques used for excavation including the process of benching. Calculations 122633-C-004, 'Slope Stability Analysis' (Attachment A), and 300013-C-001, 'Crane Stability Analysis' (Attachment B), have been prepared to support this evaluation. As shown in the calculations the soil has the following properties: Unit weight 110 pounds per cubic foot; and Friction Angle (natural angle of repose) 38{sup o} or 1.28 horizontal to 1 vertical. Setback distances are measured from the top edge of the slope to the wheels/tracks of the vehicles and heavy equipment being utilized. The computer program utilized in the calculation uses the center of the wheel or track load for the analysis and this difference is accounted for in this evaluation.

Slope Stability Evaluation And Equipment Setback Distances For Burial Ground Excavations

International Nuclear Information System (INIS)

Mcshane, D.S.

2010-01-01

After 1970 Transuranic (TRU) and suspect TRU waste was buried in the ground with the intention that at some later date the waste would be retrieved and processed into a configuration for long term storage. To retrieve this waste the soil must be removed (excavated). Sloping the bank of the excavation is the method used to keep the excavation from collapsing and to provide protection for workers retrieving the waste. The purpose of this paper is to document the minimum distance (setback) that equipment must stay from the edge of the excavation to maintain a stable slope. This evaluation examines the equipment setback distance by dividing the equipment into two categories, (1) equipment used for excavation and (2) equipment used for retrieval. The section on excavation equipment will also discuss techniques used for excavation including the process of benching. Calculations 122633-C-004, 'Slope Stability Analysis' (Attachment A), and 300013-C-001, 'Crane Stability Analysis' (Attachment B), have been prepared to support this evaluation. As shown in the calculations the soil has the following properties: Unit weight 110 pounds per cubic foot; and Friction Angle (natural angle of repose) 38 o or 1.28 horizontal to 1 vertical. Setback distances are measured from the top edge of the slope to the wheels/tracks of the vehicles and heavy equipment being utilized. The computer program utilized in the calculation uses the center of the wheel or track load for the analysis and this difference is accounted for in this evaluation.

The Use of Ground Penetrating Radar to extend the Results of Archaeological Excavation

Science.gov (United States)

Utsi, E.

2009-04-01

The condition of the Romano-British archaeological site in Wortley, Gloucestershire, UK is typical of sites of the period in that it has been heavily robbed out since it first fell into disuse. Building materials taken from the site have been re-used over the centuries to construct other local buildings. This makes both preservation of the extant remains and interpretation of the excavation problematic. Following the accidental discovery of the site in the 1980s, a programme of excavation was set in place. This excavation was run as a practical archaeological training school and, as a result, a wide range of archaeological and geophysical techniques were applied to the site. This included the introduction of Ground Penetrating Radar (GPR). The preliminary results of the first GPR used on site were not entirely satisfactory which led to the development of a new radar in the early 1990s, specifically developed for use on archaeological sites. The excavation and GPR results were published in a series of excavation reports [1] [2]. It was not possible to excavate fully for two reasons. Firstly the site crossed present day ownership boundaries and secondly the ownership of the excavation area changed. At this point the excavation was summarily terminated. In 2007, permission was given by the owner of an adjacent property to carry out a GPR survey over their land in order to derive additional information, if possible. An area survey was carried out in May 2007 with reduced transect spacing [3]. The radar data showed similar patterning to that of the original investigation i.e. substantial remains which had been subject to a high degree of post-occupational attrition. Time slices from the radar survey were matched to the principal excavation plans. It proved possible to deduce the full extent of certain partially excavated features, notably the courtyard and bath house. It was also possible to demonstrate that one part of the adjacent property did not contain similar

Stochasticity in the Josephson map

International Nuclear Information System (INIS)

Nomura, Y.; Ichikawa, Y.H.; Filippov, A.T.

1996-04-01

The Josephson map describes nonlinear dynamics of systems characterized by standard map with the uniform external bias superposed. The intricate structures of the phase space portrait of the Josephson map are examined on the basis of the tangent map associated with the Josephson map. Numerical observation of the stochastic diffusion in the Josephson map is examined in comparison with the renormalized diffusion coefficient calculated by the method of characteristic function. The global stochasticity of the Josephson map occurs at the values of far smaller stochastic parameter than the case of the standard map. (author)

Study on Excavation of Particular Part of Underground Cavern for Hydropower Station

Science.gov (United States)

Yang, Yang; Zhang, Feng; Shang, Qin; Zheng, Huakang

2018-01-01

In the present study, regarding four particular parts of underground cavern for hydropower station, i.e., crown, high sidewall, the intersection between high sidewall and tunnel and tailrace tunnel, by summarizing the previous construction experience, we have proposed the excavation approach based on “middle first and edge later, soft first and hard later”, “layered construction by excavating the thin layer first and supporting as the layer advances”, “tunnel first and wall later, small tunnels into large ones” and “excavating tunnels supported by separation piers”. In addition, the proposed excavation approach has been analyzed and verified with finite element numerical simulation. The result has indicated that the proposed special approach is reasonable and effective to reduce the turbulence on surrounding rocks, lower the influence of unloading during excavating and enhance the local and global stability of caverns and surrounding rocks.

Stochastic Community Assembly: Does It Matter in Microbial Ecology?

Science.gov (United States)

Zhou, Jizhong; Ning, Daliang

2017-12-01

Understanding the mechanisms controlling community diversity, functions, succession, and biogeography is a central, but poorly understood, topic in ecology, particularly in microbial ecology. Although stochastic processes are believed to play nonnegligible roles in shaping community structure, their importance relative to deterministic processes is hotly debated. The importance of ecological stochasticity in shaping microbial community structure is far less appreciated. Some of the main reasons for such heavy debates are the difficulty in defining stochasticity and the diverse methods used for delineating stochasticity. Here, we provide a critical review and synthesis of data from the most recent studies on stochastic community assembly in microbial ecology. We then describe both stochastic and deterministic components embedded in various ecological processes, including selection, dispersal, diversification, and drift. We also describe different approaches for inferring stochasticity from observational diversity patterns and highlight experimental approaches for delineating ecological stochasticity in microbial communities. In addition, we highlight research challenges, gaps, and future directions for microbial community assembly research. Copyright © 2017 American Society for Microbiology.

Stochastic Averaging and Stochastic Extremum Seeking

CERN Document Server

Liu, Shu-Jun

2012-01-01

Stochastic Averaging and Stochastic Extremum Seeking develops methods of mathematical analysis inspired by the interest in reverse engineering  and analysis of bacterial  convergence by chemotaxis and to apply similar stochastic optimization techniques in other environments. The first half of the text presents significant advances in stochastic averaging theory, necessitated by the fact that existing theorems are restricted to systems with linear growth, globally exponentially stable average models, vanishing stochastic perturbations, and prevent analysis over infinite time horizon. The second half of the text introduces stochastic extremum seeking algorithms for model-free optimization of systems in real time using stochastic perturbations for estimation of their gradients. Both gradient- and Newton-based algorithms are presented, offering the user the choice between the simplicity of implementation (gradient) and the ability to achieve a known, arbitrary convergence rate (Newton). The design of algorithms...

Influence of various excavation techniques on the structure and physical properties of 'near-field' rock around large boreholes

International Nuclear Information System (INIS)

Pusch, R.

1989-12-01

The procedure employed in the excavation of canister deposition holes affects the structure and physical properties of the 'near-field' rock. Except for smooth blasting, the generated damage appears to be less important than the increase in 'axial' hydraulic conductivity that is caused by stress release effects, but both combine to yield significant local flow passages. This is particularly obvious where the rock structure yield steep wedges, which is frequently occurring in granite. Percussion drilling is concluded to cause rich fine-fissuring to a distance of up to one centimeter from the borehole wall, and 'discing'. Richer fissuring and some generation of new fractures and growth of preexisting ones are produced within several decimeters from the borehole wall by full-face drilling. Core drilling has the least effect on the rock structure. Smooth blasting produces a particular form of regular fractures which appear to be determinants of the hydraulic conductivity of the near-field rock. Theoretically, its conductivity in the axial direction of blasted big holes or tunnels should be in the range of 10 -8 - 10 -6 m/s, which is in agreement with measurements in the Stripa mine. (orig.)

Modeling of excavation induced coupled hydraulic-mechanical processes in claystone

Energy Technology Data Exchange (ETDEWEB)

Massmann, Jobst

2009-07-01

Concepts for the numerical modeling of excavation induced processes in claystone are investigated. The study has been motivated by the international discussion on the adequacy of claystone as a potential host rock for a final repository of radioactive waste. The processes, which could impact the safety of such a repository, are manifold and strongly interacting. Thus, a multiphysics approach is needed, regarding solid mechanics and fluid mechanics within a geological context. A coupled modeling concept is therefore indispensable. Based on observations and measurements at an argillaceous test site (the underground laboratory Tournemire, operated by the Institute of Radioprotection and Nuclear Safety, France) the modeling concept is developed. Two main processes constitute the basis of the applied model: deformation (linear elasticity considering damage) and fluid flow (unsaturated one-phase flow). Several coupling phenomena are considered: Terzaghi 's effective stress concept, mass conservation of the liquid in a deformable porous media, drying induced shrinkage, and a permeability which depends on deformation and damage. In addition, transversely isotropic material behavior is considered. The numerical simulations are done with the finite element code RockFlow, which is extended to include: an orthotropic non-linear shrinkage model, a continuum damage model, and an orthotropic permeability model. For these new methods the theory and a literature review are presented, followed by applications, which illustrate the capability to model excavation induced processes in principle. In a comprehensive case study, the modeling concept is used to simulate the response of the Tournemire argillite to excavation. The results are compared with observations and measurements of three different excavations (century old tunnel, two galleries excavated in 1996 and 2003). In summary, it can be concluded that the developed model concept provides a prediction of the excavation induced

Modeling of excavation induced coupled hydraulic-mechanical processes in claystone

International Nuclear Information System (INIS)

Massmann, Jobst

2009-01-01

Concepts for the numerical modeling of excavation induced processes in claystone are investigated. The study has been motivated by the international discussion on the adequacy of claystone as a potential host rock for a final repository of radioactive waste. The processes, which could impact the safety of such a repository, are manifold and strongly interacting. Thus, a multiphysics approach is needed, regarding solid mechanics and fluid mechanics within a geological context. A coupled modeling concept is therefore indispensable. Based on observations and measurements at an argillaceous test site (the underground laboratory Tournemire, operated by the Institute of Radioprotection and Nuclear Safety, France) the modeling concept is developed. Two main processes constitute the basis of the applied model: deformation (linear elasticity considering damage) and fluid flow (unsaturated one-phase flow). Several coupling phenomena are considered: Terzaghi 's effective stress concept, mass conservation of the liquid in a deformable porous media, drying induced shrinkage, and a permeability which depends on deformation and damage. In addition, transversely isotropic material behavior is considered. The numerical simulations are done with the finite element code RockFlow, which is extended to include: an orthotropic non-linear shrinkage model, a continuum damage model, and an orthotropic permeability model. For these new methods the theory and a literature review are presented, followed by applications, which illustrate the capability to model excavation induced processes in principle. In a comprehensive case study, the modeling concept is used to simulate the response of the Tournemire argillite to excavation. The results are compared with observations and measurements of three different excavations (century old tunnel, two galleries excavated in 1996 and 2003). In summary, it can be concluded that the developed model concept provides a prediction of the excavation induced

Modeling of excavation induced coupled hydraulic-mechanical processes in claystone

Energy Technology Data Exchange (ETDEWEB)

Massmann, Jobst

2009-07-01

Concepts for the numerical modeling of excavation induced processes in claystone are investigated. The study has been motivated by the international discussion on the adequacy of claystone as a potential host rock for a final repository of radioactive waste. The processes, which could impact the safety of such a repository, are manifold and strongly interacting. Thus, a multiphysics approach is needed, regarding solid mechanics and fluid mechanics within a geological context. A coupled modeling concept is therefore indispensable. Based on observations and measurements at an argillaceous test site (the underground laboratory Tournemire, operated by the Institute of Radioprotection and Nuclear Safety, France) the modeling concept is developed. Two main processes constitute the basis of the applied model: deformation (linear elasticity considering damage) and fluid flow (unsaturated one-phase flow). Several coupling phenomena are considered: Terzaghi 's effective stress concept, mass conservation of the liquid in a deformable porous media, drying induced shrinkage, and a permeability which depends on deformation and damage. In addition, transversely isotropic material behavior is considered. The numerical simulations are done with the finite element code RockFlow, which is extended to include: an orthotropic non-linear shrinkage model, a continuum damage model, and an orthotropic permeability model. For these new methods the theory and a literature review are presented, followed by applications, which illustrate the capability to model excavation induced processes in principle. In a comprehensive case study, the modeling concept is used to simulate the response of the Tournemire argillite to excavation. The results are compared with observations and measurements of three different excavations (century old tunnel, two galleries excavated in 1996 and 2003). In summary, it can be concluded that the developed model concept provides a prediction of the excavation

Reconstruction of measurable three-dimensional point cloud model based on large-scene archaeological excavation sites

Science.gov (United States)

Zhang, Chun-Sen; Zhang, Meng-Meng; Zhang, Wei-Xing

2017-01-01

This paper outlines a low-cost, user-friendly photogrammetric technique with nonmetric cameras to obtain excavation site digital sequence images, based on photogrammetry and computer vision. Digital camera calibration, automatic aerial triangulation, image feature extraction, image sequence matching, and dense digital differential rectification are used, combined with a certain number of global control points of the excavation site, to reconstruct the high precision of measured three-dimensional (3-D) models. Using the acrobatic figurines in the Qin Shi Huang mausoleum excavation as an example, our method solves the problems of little base-to-height ratio, high inclination, unstable altitudes, and significant ground elevation changes affecting image matching. Compared to 3-D laser scanning, the 3-D color point cloud obtained by this method can maintain the same visual result and has advantages of low project cost, simple data processing, and high accuracy. Structure-from-motion (SfM) is often used to reconstruct 3-D models of large scenes and has lower accuracy if it is a reconstructed 3-D model of a small scene at close range. Results indicate that this method quickly achieves 3-D reconstruction of large archaeological sites and produces heritage site distribution of orthophotos providing a scientific basis for accurate location of cultural relics, archaeological excavations, investigation, and site protection planning. This proposed method has a comprehensive application value.

Geohydromechanical Processes in the Excavation Damaged Zone in Crystalline Rock, Rock Salt, and Indurated and Plastic Clays

International Nuclear Information System (INIS)

Tsang, Chin-Fu; Bernier, Frederic; Davies, Christophe

2004-01-01

The creation of an excavation disturbed zone or excavation damaged zone is expected around all man-made openings in geologic formations. Macro- and micro-fracturing, and in general a redistribution of in situ stresses and rearrangement of rock structures, will occur in this zone, resulting in drastic changes of permeability to flow, mainly through the fractures and cracks induced by excavation. Such an EDZ may have significant implications for the operation and long-term performance of an underground nuclear waste repository. Various issues of concern need to be evaluated, such as processes creating fractures in the excavation damaged zone, the degree of permeability increase, and the potential for sealing or healing (with permeability reduction) in the zone. In recent years, efforts along these lines have been made for a potential repository in four rock types-crystalline rock, salt, indurated clay, and plastic clay-and these efforts have involved field, laboratory, and theoretical studies. The present work involves a synthesis of the ideas and issues that emerged from presentations and discussions on EDZ in these four rock types at a CLUSTER Conference and Workshop held in Luxembourg in November, 2003. First, definitions of excavation disturbed and excavation damaged zones are proposed. Then, an approach is suggested for the synthesis and intercomparison of geohydromechanical processes in the EDZ for the four rock types (crystalline rock, salt, indurated clay, and plastic clay). Comparison tables of relevant processes, associated factors, and modeling and testing techniques are developed. A discussion of the general state-of-the-art and outstanding issues are also presented. A substantial bibliography of relevant papers on the subject is supplied at the end of the paper

Simulating the time-dependent behaviour of excavations in hard rock

CSIR Research Space (South Africa)

Malan, DF

2002-10-01

Full Text Available (1993) estimated the rock disintegration of the roof of the Swedish repository at Forsmark where the excavation is intersected by a fracture zone. By generalising the structure to be one of regular layers of blocks and applying a log- time creep law, he... and secondary closure in squeezing tunnels. Tertiary movements can be considered by providing suitable laws relating the values of the mechanical parameters (such as viscosity) to the irreversible part of the time-dependent strain. These rheological models...

Modelling bucket excavation by finite element

Science.gov (United States)

Pecingina, O. M.

2015-11-01

Changes in geological components of the layers from lignite pits have an impact on the sustainability of the cup path elements and under the action of excavation force appear efforts leading to deformation of the entire assembly. Application of finite element method in the optimization of components leads to economic growth, to increase the reliability and durability of the studied machine parts thus the machine. It is obvious usefulness of knowledge the state of mechanical tensions that the designed piece or the assembly not to break under the action of tensions that must cope during operation. In the course of excavation work on all bucket cutting force components, the first coming into contact with the material being excavated cutting edge. Therefore in the study with finite element analysis is retained only cutting edge. To study the field of stress and strain on the cutting edge will be created geometric patterns for each type of cup this will be subject to static analysis. The geometric design retains the cutting edge shape and on this on the tooth cassette location will apply an areal force on the abutment tooth. The cutting edge real pattern is subjected to finite element study for the worst case of rock cutting by symmetrical and asymmetrical cups whose profile is different. The purpose of this paper is to determine the displacement and tensions field for both profiles considering the maximum force applied on the cutting edge and the depth of the cutting is equal with the width of the cutting edge of the tooth. It will consider the worst case when on the structure will act both the tangential force and radial force on the bucket profile. For determination of stress and strain field on the form design of cutting edge profile will apply maximum force assuming uniform distribution and on the edge surface force will apply a radial force. After geometric patterns discretization on the cutting knives and determining stress field, can be seen that at the

A stochastic global identification framework for aerospace structures operating under varying flight states

Science.gov (United States)

Kopsaftopoulos, Fotis; Nardari, Raphael; Li, Yu-Hung; Chang, Fu-Kuo

2018-01-01

In this work, a novel data-based stochastic "global" identification framework is introduced for aerospace structures operating under varying flight states and uncertainty. In this context, the term "global" refers to the identification of a model that is capable of representing the structure under any admissible flight state based on data recorded from a sample of these states. The proposed framework is based on stochastic time-series models for representing the structural dynamics and aeroelastic response under multiple flight states, with each state characterized by several variables, such as the airspeed, angle of attack, altitude and temperature, forming a flight state vector. The method's cornerstone lies in the new class of Vector-dependent Functionally Pooled (VFP) models which allow the explicit analytical inclusion of the flight state vector into the model parameters and, hence, system dynamics. This is achieved via the use of functional data pooling techniques for optimally treating - as a single entity - the data records corresponding to the various flight states. In this proof-of-concept study the flight state vector is defined by two variables, namely the airspeed and angle of attack of the vehicle. The experimental evaluation and assessment is based on a prototype bio-inspired self-sensing composite wing that is subjected to a series of wind tunnel experiments under multiple flight states. Distributed micro-sensors in the form of stretchable sensor networks are embedded in the composite layup of the wing in order to provide the sensing capabilities. Experimental data collected from piezoelectric sensors are employed for the identification of a stochastic global VFP model via appropriate parameter estimation and model structure selection methods. The estimated VFP model parameters constitute two-dimensional functions of the flight state vector defined by the airspeed and angle of attack. The identified model is able to successfully represent the wing

Prediction of permeability changes in an excavation response zone

International Nuclear Information System (INIS)

Kinoshita, Naoto; Ishii, Takashi; Kuroda, Hidetaka; Tada, Hiroyuki

1992-01-01

In geologic disposal of radioactive wastes, stress changes due to cavern excavation may expand the existing fractures and create possible bypasses for groundwater. This paper proposes a simple method for predicting permeability changes in the excavation response zones. Numerical analyses using this method predict that the response zones created by cavern excavation would differ greatly in thickness and permeability depending on the depth of the cavern site and the initial in-situ stress, that when the cavern site is deeper, response zones would expand more and permeability would increases more, and that if the ratio of horizontal to vertical in-situ stress is small, extensive permeable zones at the crown and the bottom would occur, whereas if the ratio is large, extensive permeable zones would occur in the side walls. (orig.)

Design of the human computer interface on the telerobotic small emplacement excavator

International Nuclear Information System (INIS)

Thompson, D.H.; Killough, S.M.; Burks, B.L.; Draper, J.V.

1995-01-01

The small emplacement excavator (SEE) is a ruggedized military vehicle with backhoe and front loader used by the U.S. Army for explosive ordinance disposal (EOD) and general utility excavation activities. This project resulted from a joint need in the U.S. Department of Energy (DOE) for a remote controlled excavator for buried waste operations and the U.S. Department of Defense for remote EOD operations. To evaluate the feasibility of removing personnel from the SEE vehicle during high-risk excavation tasks, a development and demonstration project was initiated. Development of a telerobotic SEE (TSEE) was performed by the Oak Ridge National Laboratory in a project funded jointly by the U.S. Army and the DOE. The TSEE features teleoperated driving, a telerobotic backhoe with four degrees of freedom, and a teleoperated front loader with two degrees of freedom on the bucket. Remote capabilities include driving (forward, reverse, brake, steering), power takeoff shifting to enable digging modes, deploying stabilizers, excavation, and computer system booting

Minimizing the stochasticity of halos in large-scale structure surveys

Science.gov (United States)

Hamaus, Nico; Seljak, Uroš; Desjacques, Vincent; Smith, Robert E.; Baldauf, Tobias

2010-08-01

In recent work (Seljak, Hamaus, and Desjacques 2009) it was found that weighting central halo galaxies by halo mass can significantly suppress their stochasticity relative to the dark matter, well below the Poisson model expectation. This is useful for constraining relations between galaxies and the dark matter, such as the galaxy bias, especially in situations where sampling variance errors can be eliminated. In this paper we extend this study with the goal of finding the optimal mass-dependent halo weighting. We use N-body simulations to perform a general analysis of halo stochasticity and its dependence on halo mass. We investigate the stochasticity matrix, defined as Cij≡⟨(δi-biδm)(δj-bjδm)⟩, where δm is the dark matter overdensity in Fourier space, δi the halo overdensity of the i-th halo mass bin, and bi the corresponding halo bias. In contrast to the Poisson model predictions we detect nonvanishing correlations between different mass bins. We also find the diagonal terms to be sub-Poissonian for the highest-mass halos. The diagonalization of this matrix results in one large and one low eigenvalue, with the remaining eigenvalues close to the Poisson prediction 1/n¯, where n¯ is the mean halo number density. The eigenmode with the lowest eigenvalue contains most of the information and the corresponding eigenvector provides an optimal weighting function to minimize the stochasticity between halos and dark matter. We find this optimal weighting function to match linear mass weighting at high masses, while at the low-mass end the weights approach a constant whose value depends on the low-mass cut in the halo mass function. This weighting further suppresses the stochasticity as compared to the previously explored mass weighting. Finally, we employ the halo model to derive the stochasticity matrix and the scale-dependent bias from an analytical perspective. It is remarkably successful in reproducing our numerical results and predicts that the

Consistent Stochastic Modelling of Meteocean Design Parameters

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Sterndorff, M. J.

2000-01-01

Consistent stochastic models of metocean design parameters and their directional dependencies are essential for reliability assessment of offshore structures. In this paper a stochastic model for the annual maximum values of the significant wave height, and the associated wind velocity, current...

Structure and properties of Hughston's stochastic extension of the Schroedinger equation

International Nuclear Information System (INIS)

Adler, Stephen L.; Horwitz, Lawrence P.

2000-01-01

Hughston has recently proposed a stochastic extension of the Schroedinger equation, expressed as a stochastic differential equation on projective Hilbert space. We derive new projective Hilbert space identities, which we use to give a general proof that Hughston's equation leads to state vector collapse to energy eigenstates, with collapse probabilities given by the quantum mechanical probabilities computed from the initial state. We discuss the relation of Hughston's equation to earlier work on norm-preserving stochastic equations, and show that Hughston's equation can be written as a manifestly unitary stochastic evolution equation for the pure state density matrix. We discuss the behavior of systems constructed as direct products of independent subsystems, and briefly address the question of whether an energy-based approach, such as Hughston's, suffices to give an objective interpretation of the measurement process in quantum mechanics. (c) 2000 American Institute of Physics

Energy substrate used by workers of leaf-cutting ants during nest excavation

Directory of Open Access Journals (Sweden)

Roberto S. Camargo

2013-12-01

Full Text Available Energy substrate used by workers of leaf-cutting ants during nest excavation. In this study we aimed to ascertain whether leaf-cutting ant workers lose body reserves (fat or sugars as a function of nest excavation. For each treatment, we isolated 10 workers of Atta sexdens into two experimental groups, Control (C- without excavation and Soil (S- with excavation, which were kept for different time intervals (0, 24, 48 or 72 hours, totaling 700 tested workers. We then determined the concentration of soluble carbohydrates and total lipid content in them. The total carbohydrates were determined colorimetrically, based on the reaction between carbohydrates and sulfuric acid-phenol. For determination of lipids, the insects were immersed in organic solvent until they reached a constant weight. Our results showed that carbohydrates are consumed during nest excavation activities. In the experimental groups S24, S48 and S72, there was an average reduction of 5.82 (20.42%, 14.31 (44.96% and 13.27 (43.96% µ.mg-1 in soluble sugar when compared with the experimental groups that did not excavate. Furthermore, the lipids were not used during this activity. With respect to dry mass of the workers, their values were C0 = 8%, C24 = 10.4%, C48 = 9.2%, C72 = 10%, S24 = 9.2%, S48 = 8.7% and S72 = 8.5%. Our results show experimentally that the source of energy for nest excavation is carbohydrates, whereas lipids are conserved for other activities.

Adaptive stochastic Galerkin FEM with hierarchical tensor representations

KAUST Repository

Eigel, Martin

2016-01-01

PDE with stochastic data usually lead to very high-dimensional algebraic problems which easily become unfeasible for numerical computations because of the dense coupling structure of the discretised stochastic operator. Recently, an adaptive

Momentum Maps and Stochastic Clebsch Action Principles

Science.gov (United States)

Cruzeiro, Ana Bela; Holm, Darryl D.; Ratiu, Tudor S.

2018-01-01

We derive stochastic differential equations whose solutions follow the flow of a stochastic nonlinear Lie algebra operation on a configuration manifold. For this purpose, we develop a stochastic Clebsch action principle, in which the noise couples to the phase space variables through a momentum map. This special coupling simplifies the structure of the resulting stochastic Hamilton equations for the momentum map. In particular, these stochastic Hamilton equations collectivize for Hamiltonians that depend only on the momentum map variable. The Stratonovich equations are derived from the Clebsch variational principle and then converted into Itô form. In comparing the Stratonovich and Itô forms of the stochastic dynamical equations governing the components of the momentum map, we find that the Itô contraction term turns out to be a double Poisson bracket. Finally, we present the stochastic Hamiltonian formulation of the collectivized momentum map dynamics and derive the corresponding Kolmogorov forward and backward equations.

Investigation of Hexavalent Chromium Flux to Groundwater at the 100-C-7:1 Excavation Site

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J.; Vermeul, Vincent R.; Fritz, Brad G.; Mackley, Rob D.; Horner, Jacob A.; Johnson, Christian D.; Newcomer, Darrell R.

2012-11-16

Deep excavation of soil has been conducted at the 100-C-7 and 100-C-7:1 waste sites within the 100-BC Operable Unit at the Department of Energy (DOE) Hanford Site to remove hexavalent chromium (Cr(VI)) contamination with the excavations reaching to near the water table. Soil sampling showed that Cr(VI) contamination was still present at the bottom of the 100-C-7:1 excavation. In addition, Cr(VI) concentrations in a downgradient monitoring well have shown a transient spike of increased Cr(VI) concentration following initiation of excavation. Potentially, the increased Cr(VI) concentrations in the downgradient monitoring well are due to Cr(VI) from the excavation site. However, data were needed to evaluate this possibility and to quantify the overall impact of the 100-C-7:1 excavation site on groundwater. Data collected from a network of aquifer tubes installed across the floor of the 100-C-7:1 excavation and from temporary wells installed at the bottom of the entrance ramp to the excavation were used to evaluate Cr(VI) releases into the aquifer and to estimate local-scale hydraulic properties and groundwater flow velocity.

Comparison of Traditional Design Nonlinear Programming Optimization and Stochastic Methods for Structural Design

Science.gov (United States)

Patnaik, Surya N.; Pai, Shantaram S.; Coroneos, Rula M.

2010-01-01

Structural design generated by traditional method, optimization method and the stochastic design concept are compared. In the traditional method, the constraints are manipulated to obtain the design and weight is back calculated. In design optimization, the weight of a structure becomes the merit function with constraints imposed on failure modes and an optimization algorithm is used to generate the solution. Stochastic design concept accounts for uncertainties in loads, material properties, and other parameters and solution is obtained by solving a design optimization problem for a specified reliability. Acceptable solutions were produced by all the three methods. The variation in the weight calculated by the methods was modest. Some variation was noticed in designs calculated by the methods. The variation may be attributed to structural indeterminacy. It is prudent to develop design by all three methods prior to its fabrication. The traditional design method can be improved when the simplified sensitivities of the behavior constraint is used. Such sensitivity can reduce design calculations and may have a potential to unify the traditional and optimization methods. Weight versus reliabilitytraced out an inverted-S-shaped graph. The center of the graph corresponded to mean valued design. A heavy design with weight approaching infinity could be produced for a near-zero rate of failure. Weight can be reduced to a small value for a most failure-prone design. Probabilistic modeling of load and material properties remained a challenge.

Electron thermal confinement in a partially stochastic magnetic structure

Science.gov (United States)

Morton, L. A.; Young, W. C.; Hegna, C. C.; Parke, E.; Reusch, J. A.; Den Hartog, D. J.

2018-04-01

Using a high-repetition-rate Thomson scattering diagnostic, we observe a peak in electron temperature Te coinciding with the location of a large magnetic island in the Madison Symmetric Torus. Magnetohydrodynamic modeling of this quasi-single helicity plasma indicates that smaller adjacent islands overlap with and destroy the large island flux surfaces. The estimated stochastic electron thermal conductivity ( ≈30 m 2/s ) is consistent with the conductivity inferred from the observed Te gradient and ohmic heating power. Island-shaped Te peaks can result from partially stochastic magnetic islands.

Stochastic-Strength-Based Damage Simulation Tool for Ceramic Matrix and Polymer Matrix Composite Structures

Science.gov (United States)

Nemeth, Noel N.; Bednarcyk, Brett A.; Pineda, Evan J.; Walton, Owen J.; Arnold, Steven M.

2016-01-01

Stochastic-based, discrete-event progressive damage simulations of ceramic-matrix composite and polymer matrix composite material structures have been enabled through the development of a unique multiscale modeling tool. This effort involves coupling three independently developed software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/ Life), and (3) the Abaqus finite element analysis (FEA) program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating unit cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC. Abaqus is used at the global scale to model the overall composite structure. An Abaqus user-defined material (UMAT) interface, referred to here as "FEAMAC/CARES," was developed that enables MAC/GMC and CARES/Life to operate seamlessly with the Abaqus FEA code. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events, which incrementally progress and lead to ultimate structural failure. This report describes the FEAMAC/CARES methodology and discusses examples that illustrate the performance of the tool. A comprehensive example problem, simulating the progressive damage of laminated ceramic matrix composites under various off-axis loading conditions and including a double notched tensile specimen geometry, is described in a separate report.

Analytic stochastic regularization and gange invariance

International Nuclear Information System (INIS)

Abdalla, E.; Gomes, M.; Lima-Santos, A.

1986-05-01

A proof that analytic stochastic regularization breaks gauge invariance is presented. This is done by an explicit one loop calculation of the vaccum polarization tensor in scalar electrodynamics, which turns out not to be transversal. The counterterm structure, Langevin equations and the construction of composite operators in the general framework of stochastic quantization, are also analysed. (Author) [pt

Coupling Neumann development and component mode synthesis methods for stochastic analysis of random structures

Directory of Open Access Journals (Sweden)

Driss Sarsri

2014-05-01

Full Text Available In this paper, we propose a method to calculate the first two moments (mean and variance of the structural dynamics response of a structure with uncertain variables and subjected to random excitation. For this, Newmark method is used to transform the equation of motion of the structure into a quasistatic equilibrium equation in the time domain. The Neumann development method was coupled with Monte Carlo simulations to calculate the statistical values of the random response. The use of modal synthesis methods can reduce the dimensions of the model before integration of the equation of motion. Numerical applications have been developed to highlight effectiveness of the method developed to analyze the stochastic response of large structures.

Ambit processes and stochastic partial differential equations

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole; Benth, Fred Espen; Veraart, Almut

Ambit processes are general stochastic processes based on stochastic integrals with respect to Lévy bases. Due to their flexible structure, they have great potential for providing realistic models for various applications such as in turbulence and finance. This papers studies the connection betwe...... ambit processes and solutions to stochastic partial differential equations. We investigate this relationship from two angles: from the Walsh theory of martingale measures and from the viewpoint of the Lévy noise analysis....

Stochastic Optimisation of Battery System Operation Strategy under different Utility Tariff Structures

OpenAIRE

Erdal, Jørgen Sørgård

2017-01-01

This master thesis develops a stochastic optimisation software for household grid-connected batteries combined with PV-systems. The objective of the optimisation is to operate the battery system in order to minimise the costs of the consumer, and it was implemented in MATLAB using a self-written stochastic dynamic programming algorithm. Load was considered as a stochastic variable and modelled as a Markov Chain. Transition probabilities between time steps were calculated using historic load p...

Bucket wheel excavators for open-cast mining all over the world

Energy Technology Data Exchange (ETDEWEB)

Durst, W.

1979-04-01

A report is given on the use of bucket wheel excavators, spreaders and tripper cars in open-cast mining of brown coal, oilsand and other minerals in Australia, Canada, India, Spain, USA and Yugoslavia as well as on the use of bucket wheel excavators for land reclamation in Singapore.

Estimating RMR Values for Underground Excavations in a Rock Mass

Directory of Open Access Journals (Sweden)

Vítor Santos

2018-02-01

Full Text Available During underground excavations for civil or mining engineering purposes, the variations in rock mass quality are important, especially for the design of the most suitable support to be applied to ensure stability. The aim of this investigation is to model the expected behavior of the ground, and thus to predict the scenarios indicating potential variations in the quality of the rock mass during underground excavation. When considering the rock mass rating (RMR values observed at the excavation face in six study cases, which together total more than 27 km in length of underground excavation by drilling and blasting (D&B, and based on the observed RMR values at the face, the most probable value (1–100 is estimate for the RMR index at the five subsequent front advances. It is concluded that, up to about 20 m ahead of the current face, the quality of the rock mass for the next advances is close to the quality observed at the present face, and that, with increasing distance, there is a greater deviation of RMR values with respect to the quality observed at the current face.

A Stochastic Polygons Model for Glandular Structures in Colon Histology Images.

Science.gov (United States)

Sirinukunwattana, Korsuk; Snead, David R J; Rajpoot, Nasir M

2015-11-01

In this paper, we present a stochastic model for glandular structures in histology images of tissue slides stained with Hematoxylin and Eosin, choosing colon tissue as an example. The proposed Random Polygons Model (RPM) treats each glandular structure in an image as a polygon made of a random number of vertices, where the vertices represent approximate locations of epithelial nuclei. We formulate the RPM as a Bayesian inference problem by defining a prior for spatial connectivity and arrangement of neighboring epithelial nuclei and a likelihood for the presence of a glandular structure. The inference is made via a Reversible-Jump Markov chain Monte Carlo simulation. To the best of our knowledge, all existing published algorithms for gland segmentation are designed to mainly work on healthy samples, adenomas, and low grade adenocarcinomas. One of them has been demonstrated to work on intermediate grade adenocarcinomas at its best. Our experimental results show that the RPM yields favorable results, both quantitatively and qualitatively, for extraction of glandular structures in histology images of normal human colon tissues as well as benign and cancerous tissues, excluding undifferentiated carcinomas.

Stochastic Control Synthesis of Systems with Structured Uncertainty

Science.gov (United States)

Padula, Sharon L. (Technical Monitor); Crespo, Luis G.

2003-01-01

This paper presents a study on the design of robust controllers by using random variables to model structured uncertainty for both SISO and MIMO feedback systems. Once the parameter uncertainty is prescribed with probability density functions, its effects are propagated through the analysis leading to stochastic metrics for the system's output. Control designs that aim for satisfactory performances while guaranteeing robust closed loop stability are attained by solving constrained non-linear optimization problems in the frequency domain. This approach permits not only to quantify the probability of having unstable and unfavorable responses for a particular control design but also to search for controls while favoring the values of the parameters with higher chance of occurrence. In this manner, robust optimality is achieved while the characteristic conservatism of conventional robust control methods is eliminated. Examples that admit closed form expressions for the probabilistic metrics of the output are used to elucidate the nature of the problem at hand and validate the proposed formulations.

Dig-face monitoring during excavation of a radioactive plume at Mound Laboratory, Ohio

International Nuclear Information System (INIS)

Josten, N.E.; Gehrke, R.J.; Carpenter, M.V.

1995-12-01

A dig-face monitoring system consists of onsite hardware for collecting information on changing chemical, radiological, and physical conditions in the subsurface soil during the hazardous site excavation. A prototype dig-face system was take to Mount Laboratory for a first trial. Mound Area 7 was the site of historical disposals of 232 Th, 227 Ac, and assorted debris. The system was used to monitor a deep excavation aimed at removing 227 Ac-contaminated soils. Radiological, geophysical, and topographic sensors were used to scan across the excavation dig-face at four successive depths as soil was removed. A 3-D image of the contamination plumes was developed; the radiation sensor data indicated that only a small portion of the excavated soil volume was contaminated. The spatial information produced by the dig-face system was used to direct the excavation activities into the area containing the 227 Ac and to evaluate options for handling the separate 232 Th plume

Numerical study on lateral wall displacement of deep excavation supported by IPS earth retention system

Directory of Open Access Journals (Sweden)

Tugen Feng

2017-12-01

Full Text Available The objective of this study is to investigate the 3D behavior characteristics of an excavation supported by an innovative prestressed support (IPS earth retention system. A numerical simulation was conducted in order to provide insight into the IPS system behavior by using the FLAC3D package. Prior to the parametric study, validation work was conducted by means of a comparison of the deformation between the field test data and numerical analysis results, and strong agreement was obtained. The reasonable excavation location, layered excavation thickness, and blocked excavation sequence are presented according to variable parameter analysis. In view of the previous findings, certain measurements are proposed in order to control the foundation pit deformation. The results indicate that prestress compensation has a significant effect on the IPS system behavior, while an optimized excavation sequence slightly improves its behavior. With the conclusion proposed based on the numerical results, the aim is to provide reference data for optimization design and the construction sequence. Keywords: FLAC3D, IPS system, Prestress compensation, Layered excavation, Blocked excavation, Deformation control

Controlled drill ampersand blast excavation at AECL's Underground Research Laboratory

International Nuclear Information System (INIS)

Kuzyk, G.W.; Onagi, D.P.; Thompson, P.M.

1996-01-01

A controlled drill and blast method has been developed and used to excavate the Underground Research Laboratory, a geotechnical facility constructed by Atomic Energy of Canada Limited (AECL) in crystalline rock. It has been demonstrated that the method can effectively reduce the excavation disturbed zone (EDZ) and is suitable for the construction of a used fuel disposal vault in the plutonic rock of the Canadian Shield

Affine stochastic mortality

NARCIS (Netherlands)

Schrager, D.F.

2006-01-01

We propose a new model for stochastic mortality. The model is based on the literature on affine term structure models. It satisfies three important requirements for application in practice: analytical tractibility, clear interpretation of the factors and compatibility with financial option pricing

Bucket wheel rehabilitation of ERC 1400-30/7 high-capacity excavators from lignite quarries

Science.gov (United States)

Vîlceanu, Fl; Iancu, C.

2016-11-01

The existence of bucket wheel equipment type ERC 1400-30/7 in lignite quarries with lifetime expired, or in the ultimate life period, together with high cost investments for their replacement, makes rational the efforts made to rehabilitation in order to extend their life. Rehabilitation involves checking operational safety based on relevant expertise of metal structures supporting effective resistance but also the replacement (or modernization) of subassemblies that can increase excavation process productivity, lowering energy consumption, reducing mechanical stresses. This paper proposes an analysis of constructive solution of using a part of the classical bucket wheel, on which are located 9 cutting cups and 9 chargers cups and adding a new part so that the new redesigned bucket-wheel will contain 18 cutting-chargers cups, compared to the classical model. On the CAD model of bucket wheel was performed a static and a dynamic FEA, the results being compared with the yield strength of the material of the entire structure, were checked mechanical stresses in the overall distribution map, and were verified the first 4 vibrating modes the structure compared to real loads. Thus was verified that the redesigned bucket-wheel can accomplish the proposed goals respectively increase excavation process productivity, lowering energy consumption and reducing mechanical stresses.

Time-dependent evolution of the excavation damaged zone in the argillaceous Tournemire site

Energy Technology Data Exchange (ETDEWEB)

Rejeb, A.; Cabrera, J. [Institut de Radioprotection et de Surete Nucleaire (IRSN/DEI/SARG), Lab. d' Etude Hydrodynamique et Geotechnique, 92 - Fontenay-aux-Roses (France)

2006-07-01

The experimental Tournemire site enables the assessment of the Excavation Damaged Zones (EDZ) around three structures excavated in argilites: the century-old tunnel, the ten year-old east and west galleries, and the three year-old main gallery. This paper discusses the main experimental results concerning the EDZ characterisation and their interpretation. EDZ fracture analyses from the galleries (cartography) and the radial boreholes (core analyses) allow for accurate structural characterisation of the EDZs. The tunnel has an EDZ with dense, homogeneous fracturing parallel to the wall, resembling onion skins. However, the new galleries do not have an EDZ similar to that of the tunnel. Unsaturated micro-cracks, mainly parallel to the bedding planes are observed on the non covered walls of each gallery. The extent of the EDZ does not seem to be affected by the age of the structure. It is approximately 20 % of the mean radius of the structure. Based on the modelling and experimental characterisation work completed, it is considered that the EDZ in this argillaceous Tournemire site is due to a deferred failure. At first time, when the wall of the structures are not covered the desaturation/re-saturation phenomena induced a tensile failure around the new galleries. During the time, these desaturation/re-saturation phenomena cause a gradual weakening of the material. The EDZ tunnel fractures are explained by this possible hydric damage and a decreasing mechanical strength with the time. These assumptions remain to be confirmed through coupled numerical modelling in unsaturated medium. (authors)

Time-dependent evolution of the excavation damaged zone in the argillaceous Tournemire site

International Nuclear Information System (INIS)

Rejeb, A.; Cabrera, J.

2006-01-01

The experimental Tournemire site enables the assessment of the Excavation Damaged Zones (EDZ) around three structures excavated in argilites: the century-old tunnel, the ten year-old east and west galleries, and the three year-old main gallery. This paper discusses the main experimental results concerning the EDZ characterisation and their interpretation. EDZ fracture analyses from the galleries (cartography) and the radial boreholes (core analyses) allow for accurate structural characterisation of the EDZs. The tunnel has an EDZ with dense, homogeneous fracturing parallel to the wall, resembling onion skins. However, the new galleries do not have an EDZ similar to that of the tunnel. Unsaturated micro-cracks, mainly parallel to the bedding planes are observed on the non covered walls of each gallery. The extent of the EDZ does not seem to be affected by the age of the structure. It is approximately 20 % of the mean radius of the structure. Based on the modelling and experimental characterisation work completed, it is considered that the EDZ in this argillaceous Tournemire site is due to a deferred failure. At first time, when the wall of the structures are not covered the desaturation/re-saturation phenomena induced a tensile failure around the new galleries. During the time, these desaturation/re-saturation phenomena cause a gradual weakening of the material. The EDZ tunnel fractures are explained by this possible hydric damage and a decreasing mechanical strength with the time. These assumptions remain to be confirmed through coupled numerical modelling in unsaturated medium. (authors)

Performance prediction of mechanical excavators from linear cutter tests on Yucca Mountain welded tuffs

International Nuclear Information System (INIS)

Gertsch, R.; Ozdemir, L.

1992-09-01

The performances of mechanical excavators are predicted for excavations in welded tuff. Emphasis is given to tunnel boring machine evaluations based on linear cutting machine test data obtained on samples of Topopah Spring welded tuff. The tests involve measurement of forces as cutters are applied to the rock surface at certain spacing and penetrations. Two disc and two point-attack cutters representing currently available technology are thus evaluated. The performance predictions based on these direct experimental measurements are believed to be more accurate than any previous values for mechanical excavation of welded tuff. The calculations of performance are predicated on minimizing the amount of energy required to excavate the welded tuff. Specific energy decreases with increasing spacing and penetration, and reaches its lowest at the widest spacing and deepest penetration used in this test program. Using the force, spacing, and penetration data from this experimental program, the thrust, torque, power, and rate of penetration are calculated for several types of mechanical excavators. The results of this study show that the candidate excavators will require higher torque and power than heretofore estimated

Laboratory Evidence for Stochastic Plasma-Wave Growth

International Nuclear Information System (INIS)

Austin, D. R.; Hole, M. J.; Robinson, P. A.; Cairns, Iver H.; Dallaqua, R.

2007-01-01

The first laboratory confirmation of stochastic growth theory is reported. Floating potential fluctuations are measured in a vacuum arc centrifuge using a Langmuir probe. Statistical analysis of the energy density reveals a lognormal distribution over roughly 2 orders of magnitude, with a high-field nonlinear cutoff whose spatial dependence is consistent with the predicted eigenmode profile. These results are consistent with stochastic growth and nonlinear saturation of a spatially extended eigenmode, the first evidence for stochastic growth of an extended structure

Reliability and maintenance in European nuclear power plants: A structural analysis of a controlled stochastic process

International Nuclear Information System (INIS)

Sturm, R.

1991-01-01

Two aspects of performance are of main concern: plant availability and plant reliability (defined as the conditional probability of an unplanned shutdown). The goal of the research is a unified framework that combines behavioral models of optimizing agents with models of complex technical systems that take into account the dynamic and stochastic features of the system. In order to achieve this synthesis, two liens of work are necessary. One line requires a deeper understanding of complex production systems and the type of data they give rise to; the other line involves the specification and estimation of a rigorously specified behavioral model. Plant operations are modeled as a controlled stochastic process, and the sequence of up and downtime spells is analyzed during failure time and point process models. Similar to work on rational expectations and structural econometric models, the behavior model of how the plant process is controlled is formulated at the level of basic processes, i.e., the objective function of the plant manager, technical constraints, and stochastic disturbances

Excavation and aggregation as organizing factors in de novo construction by mound-building termites.

Science.gov (United States)

Green, Ben; Bardunias, Paul; Turner, J Scott; Nagpal, Radhika; Werfel, Justin

2017-06-14

Termites construct complex mounds that are orders of magnitude larger than any individual and fulfil a variety of functional roles. Yet the processes through which these mounds are built, and by which the insects organize their efforts, remain poorly understood. The traditional understanding focuses on stigmergy, a form of indirect communication in which actions that change the environment provide cues that influence future work. Termite construction has long been thought to be organized via a putative 'cement pheromone': a chemical added to deposited soil that stimulates further deposition in the same area, thus creating a positive feedback loop whereby coherent structures are built up. To investigate the detailed mechanisms and behaviours through which termites self-organize the early stages of mound construction, we tracked the motion and behaviour of major workers from two Macrotermes species in experimental arenas. Rather than a construction process focused on accumulation of depositions, as models based on cement pheromone would suggest, our results indicated that the primary organizing mechanisms were based on excavation. Digging activity was focused on a small number of excavation sites, which in turn provided templates for soil deposition. This behaviour was mediated by a mechanism of aggregation, with termites being more likely to join in the work at an excavation site as the number of termites presently working at that site increased. Statistical analyses showed that this aggregation mechanism was a response to active digging, distinct from and unrelated to putative chemical cues that stimulate deposition. Agent-based simulations quantitatively supported the interpretation that the early stage of de novo construction is primarily organized by excavation and aggregation activity rather than by stigmergic deposition. © 2017 The Author(s).

Stochastic dynamics and control

CERN Document Server

Sun, Jian-Qiao; Zaslavsky, George

2006-01-01

This book is a result of many years of author's research and teaching on random vibration and control. It was used as lecture notes for a graduate course. It provides a systematic review of theory of probability, stochastic processes, and stochastic calculus. The feedback control is also reviewed in the book. Random vibration analyses of SDOF, MDOF and continuous structural systems are presented in a pedagogical order. The application of the random vibration theory to reliability and fatigue analysis is also discussed. Recent research results on fatigue analysis of non-Gaussian stress proc

Silica exposure to excavation workers during the excavation of a low level radiological waste pit and tritium disposal shafts

International Nuclear Information System (INIS)

Wilson, K.M.

1995-01-01

This study evaluated the task-length average (TLA) respirable dust and respirable silica airborne concentrations to which construction workers excavating volcanic tuff at Los Alamos National Laboratory (LANL) were exposed. These workers were excavating a low level radiological waste disposal pit of final dimensions 720 feet long, 132 feet wide and 60 feet deep. The objectives of this study were as follows: (1) evaluate exposures; (2) determine if the type of machinery used affects the respirable dust concentration in the breathing zone of the worker; (3) evaluate the efficacy of wetting the pit to reduce the respirable dust exposure; and (4) determine if exposure increases with increasing depth of pit due to the walls of the pit blocking the cross wind ventilation

A Stochastic mesoscopic model for predicting the globular grain structure and solute redistribution in cast alloys at low superheat

International Nuclear Information System (INIS)

Nastac, Laurentiu; El Kaddah, Nagy

2012-01-01

It is well known that casting at low superheat has a strong influence on the solidification morphology and macro- and microstructures of the cast alloy. This paper describes a stochastic mesoscopic solidification model for predicting the grain structure and segregation in cast alloy at low superheat. This model was applied to predict the globular solidification morphology and size as well as solute redistribution of Al in cast Mg AZ31B alloy at superheat of 5°C produced by the Magnetic Suspension Melting (MSM) process, which is an integrated containerless induction melting and casting process. The castings produced at this low superheat have fine globular grain structure, with an average grain size of 80 μm, which is about 3 times smaller than that obtained by conventional casting techniques. The stochastic model was found to reasonably predict the observed grain structure and Al microsegregation. This makes the model a useful tool for controlling the structure of cast magnesium alloys.

29 CFR 1926.913 - Blasting in excavation work under compressed air.

Science.gov (United States)

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Blasting in excavation work under compressed air. 1926.913... Use of Explosives § 1926.913 Blasting in excavation work under compressed air. (a) Detonators and... connecting wires are connected up. (b) When detonators or explosives are brought into an air lock, no...

Summary of nuclear-excavation applications

International Nuclear Information System (INIS)

Toman, John

1970-01-01

Although many nuclear-excavation applications have been proposed, few have been seriously considered and none have been brought to fruition. This paper summarizes and discusses specific examples of a canal, a harbor, a highway cut and a nuclear quarry, all of which have been studied in some detail. It is believed that useful demonstration projects - such as a deep-water harbor and a nuclear quarry - can be safely accomplished with existing technology. Current assessments of the feasibility of constructing a sea-level canal in either Panama or Colombia appear to be favorable from a technical viewpoint. The concept of close spacing in row-charge designs has made it possible to greatly reduce the estimated required salvo yields for both proposed canals. Salvo yields have been reduced from 35 Mt to 13 Mt in Colombia and 11 Mt in Panama. As a result, the seismic motions predicted for large cities in these countries are similar to motions produced in populated areas in the United States by nuclear tests and earthquakes in which no real damage to residential or high-rise structures was noted. (author)

Summary of nuclear-excavation applications

Energy Technology Data Exchange (ETDEWEB)

Toman, John [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

1970-05-01

Although many nuclear-excavation applications have been proposed, few have been seriously considered and none have been brought to fruition. This paper summarizes and discusses specific examples of a canal, a harbor, a highway cut and a nuclear quarry, all of which have been studied in some detail. It is believed that useful demonstration projects - such as a deep-water harbor and a nuclear quarry - can be safely accomplished with existing technology. Current assessments of the feasibility of constructing a sea-level canal in either Panama or Colombia appear to be favorable from a technical viewpoint. The concept of close spacing in row-charge designs has made it possible to greatly reduce the estimated required salvo yields for both proposed canals. Salvo yields have been reduced from 35 Mt to 13 Mt in Colombia and 11 Mt in Panama. As a result, the seismic motions predicted for large cities in these countries are similar to motions produced in populated areas in the United States by nuclear tests and earthquakes in which no real damage to residential or high-rise structures was noted. (author)

Stepwise excavation in a permanent molar

DEFF Research Database (Denmark)

Lima, Fernanda Ferruzzi; Pascotto, Renata Corrêa; Benetti, Ana Raquel

2010-01-01

with zinc oxide cement were performed to minimize the risk of pulp exposure during excavation. After 45 days, the remaining carious tissue was removed and a restoration with glass-ionomer lining (Vitrebond) and resin composite (P-50) was performed. Satisfactory morphology and function of the restoration...

Optimal Control and Optimization of Stochastic Supply Chain Systems

CERN Document Server

Song, Dong-Ping

2013-01-01

Optimal Control and Optimization of Stochastic Supply Chain Systems examines its subject in the context of the presence of a variety of uncertainties. Numerous examples with intuitive illustrations and tables are provided, to demonstrate the structural characteristics of the optimal control policies in various stochastic supply chains and to show how to make use of these characteristics to construct easy-to-operate sub-optimal policies.                 In Part I, a general introduction to stochastic supply chain systems is provided. Analytical models for various stochastic supply chain systems are formulated and analysed in Part II. In Part III the structural knowledge of the optimal control policies obtained in Part II is utilized to construct easy-to-operate sub-optimal control policies for various stochastic supply chain systems accordingly. Finally, Part IV discusses the optimisation of threshold-type control policies and their robustness. A key feature of the book is its tying together of ...

Calculation of the Chilling Requirement for Air Conditioning in the Excavation Roadway

Directory of Open Access Journals (Sweden)

Yueping Qin

2015-10-01

Full Text Available To effectively improve the climate conditions of the excavation roadway in coal mine, the calculation of the chilling requirement taking air conditioning measures is extremely necessary. The temperature field of the surrounding rock with moving boundary in the excavation roadway was numerically simulated by using finite volume method. The unstable heat transfer coefficient between the surrounding rock and air flow was obtained via the previous calculation. According to the coupling effects of the air flow inside and outside air duct, the differential calculation mathematical model of air flow temperature in the excavation roadway was established. The chilling requirement was calculated with the selfdeveloped computer program for forecasting the required cooling capacity of the excavation roadway. A good air conditioning effect had been observed after applying the calculated results to field trial, which indicated that the prediction method and calculation procedure were reliable.

Energy-saving analysis of hydraulic hybrid excavator based on common pressure rail.

Science.gov (United States)

Shen, Wei; Jiang, Jihai; Su, Xiaoyu; Karimi, Hamid Reza

2013-01-01

Energy-saving research of excavators is becoming one hot topic due to the increasing energy crisis and environmental deterioration recently. Hydraulic hybrid excavator based on common pressure rail (HHEC) provides an alternative with electric hybrid excavator because it has high power density and environment friendly and easy to modify based on the existing manufacture process. This paper is focused on the fuel consumption of HHEC and the actuator dynamic response to assure that the new system can save energy without sacrificing performance. Firstly, we introduce the basic principle of HHEC; then, the sizing process is presented; furthermore, the modeling period which combined mathematical analysis and experiment identification is listed. Finally, simulation results show that HHEC has a fast dynamic response which can be accepted in engineering and the fuel consumption can be reduced 21% to compare the original LS excavator and even 32% after adopting another smaller engine.

Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

Directory of Open Access Journals (Sweden)

Daniela Römer

Full Text Available During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density

Sequential Subterranean Transport of Excavated Sand and Foraged Seeds in Nests of the Harvester Ant, Pogonomyrmex badius.

Directory of Open Access Journals (Sweden)

Walter R Tschinkel

Full Text Available During their approximately annual nest relocations, Florida harvester ants (Pogonomyrmex badius excavate large and architecturally-distinct subterranean nests. Aspects of this process were studied by planting a harvester ant colony in the field in a soil column composed of layers of 12 different colors of sand. Quantifying the colors of excavated sand dumped on the surface by the ants revealed the progress of nest deepening to 2 m and enlargement to 8 L in volume. Most of the excavation was completed within about 2 weeks, but the nest was doubled in volume after a winter lull. After 7 months, we excavated the nest and mapped its structure, revealing colored sand deposited in non-host colored layers, especially in the upper 30 to 40 cm of the nest. In all, about 2.5% of the excavated sediment was deposited below ground, a fact of importance to sediment dating by optically-stimulated luminescence (OSL. Upward transport of excavated sand is carried out in stages, probably by different groups of ants, through deposition, re-transport, incorporation into the nest walls and floors and remobilization from these. This results in considerable mixing of sand from different depths, as indicated in the multiple sand colors even within single sand pellets brought to the surface. Just as sand is transported upward by stages, incoming seeds are transported downward to seed chambers. Foragers collect seeds and deposit them only in the topmost nest chambers from which a separate group of workers rapidly transports them downward in increments detectable as a "wave" of seeds that eventually ends in the seed chambers, 20 to 80 cm below the surface. The upward and downward transport is an example of task-partitioning in a series-parallel organization of work carried out by a highly redundant work force in which each worker usually completes only part of a multi-step process.

A Stochastic Maximum Principle for a Stochastic Differential Game of a Mean-Field Type

Energy Technology Data Exchange (ETDEWEB)

Hosking, John Joseph Absalom, E-mail: j.j.a.hosking@cma.uio.no [University of Oslo, Centre of Mathematics for Applications (CMA) (Norway)

2012-12-15

We construct a stochastic maximum principle (SMP) which provides necessary conditions for the existence of Nash equilibria in a certain form of N-agent stochastic differential game (SDG) of a mean-field type. The information structure considered for the SDG is of a possible asymmetric and partial type. To prove our SMP we take an approach based on spike-variations and adjoint representation techniques, analogous to that of S. Peng (SIAM J. Control Optim. 28(4):966-979, 1990) in the optimal stochastic control context. In our proof we apply adjoint representation procedures at three points. The first-order adjoint processes are defined as solutions to certain mean-field backward stochastic differential equations, and second-order adjoint processes of a first type are defined as solutions to certain backward stochastic differential equations. Second-order adjoint processes of a second type are defined as solutions of certain backward stochastic equations of a type that we introduce in this paper, and which we term conditional mean-field backward stochastic differential equations. From the resulting representations, we show that the terms relating to these second-order adjoint processes of the second type are of an order such that they do not appear in our final SMP equations. A comparable situation exists in an article by R. Buckdahn, B. Djehiche, and J. Li (Appl. Math. Optim. 64(2):197-216, 2011) that constructs a SMP for a mean-field type optimal stochastic control problem; however, the approach we take of using these second-order adjoint processes of a second type to deal with the type of terms that we refer to as the second form of quadratic-type terms represents an alternative to a development, to our setting, of the approach used in their article for their analogous type of term.

A Stochastic Maximum Principle for a Stochastic Differential Game of a Mean-Field Type

International Nuclear Information System (INIS)

Hosking, John Joseph Absalom

2012-01-01

We construct a stochastic maximum principle (SMP) which provides necessary conditions for the existence of Nash equilibria in a certain form of N-agent stochastic differential game (SDG) of a mean-field type. The information structure considered for the SDG is of a possible asymmetric and partial type. To prove our SMP we take an approach based on spike-variations and adjoint representation techniques, analogous to that of S. Peng (SIAM J. Control Optim. 28(4):966–979, 1990) in the optimal stochastic control context. In our proof we apply adjoint representation procedures at three points. The first-order adjoint processes are defined as solutions to certain mean-field backward stochastic differential equations, and second-order adjoint processes of a first type are defined as solutions to certain backward stochastic differential equations. Second-order adjoint processes of a second type are defined as solutions of certain backward stochastic equations of a type that we introduce in this paper, and which we term conditional mean-field backward stochastic differential equations. From the resulting representations, we show that the terms relating to these second-order adjoint processes of the second type are of an order such that they do not appear in our final SMP equations. A comparable situation exists in an article by R. Buckdahn, B. Djehiche, and J. Li (Appl. Math. Optim. 64(2):197–216, 2011) that constructs a SMP for a mean-field type optimal stochastic control problem; however, the approach we take of using these second-order adjoint processes of a second type to deal with the type of terms that we refer to as the second form of quadratic-type terms represents an alternative to a development, to our setting, of the approach used in their article for their analogous type of term.

Radiological safety research for nuclear excavation projects - Interoceanic canal studies

Energy Technology Data Exchange (ETDEWEB)

Klement, Jr, A W [U.S. Atomic Energy Commission, Las Vegas, NV (United States)

1969-07-01

The general radiological problems encountered in nuclear cratering and nuclear excavation projects are discussed. Procedures for assessing radiological problems in such projects are outlined. Included in the discussions are source term, meteorology, fallout prediction and ecological factors. Continuing research requirements as well as pre- and post-excavation studies are important considerations. The procedures followed in the current interoceanic canal feasibility studies provide examples of radiological safety problems, current solutions and needed research. (author)

Radiological safety research for nuclear excavation projects - Interoceanic canal studies

International Nuclear Information System (INIS)

Klement, A.W. Jr.

1969-01-01

The general radiological problems encountered in nuclear cratering and nuclear excavation projects are discussed. Procedures for assessing radiological problems in such projects are outlined. Included in the discussions are source term, meteorology, fallout prediction and ecological factors. Continuing research requirements as well as pre- and post-excavation studies are important considerations. The procedures followed in the current interoceanic canal feasibility studies provide examples of radiological safety problems, current solutions and needed research. (author)

Reserves and cash flows under stochastic retirement

DEFF Research Database (Denmark)

Gad, Kamille Sofie Tågholt; Nielsen, Jeppe Woetmann

2016-01-01

Uncertain time of retirement and uncertain structure of retirement benefits are risk factors for life insurance companies. Nevertheless, classical life insurance models assume these are deterministic. In this paper, we include the risk from stochastic time of retirement and stochastic benefit...... structure in a classical finite-state Markov model for a life insurance contract. We include discontinuities in the distribution of the retirement time. First, we derive formulas for appropriate scaling of the benefits according to the time of retirement and discuss the link between the scaling...... and the guarantees provided. Stochastic retirement creates a need to rethink the construction of disability products for high ages and ways to handle this are discussed. We show how to calculate market reserves and how to use modified transition probabilities to calculate expected cash flows without significantly...

Simulations of DSB Yields and Radiation-induced Chromosomal Aberrations in Human Cells Based on the Stochastic Track Structure Induced by HZE Particles

Science.gov (United States)

Ponomarev, Artem; Plante, Ianik; George, Kerry; Wu, Honglu

2014-01-01

The formation of double-strand breaks (DSBs) and chromosomal aberrations (CAs) is of great importance in radiation research and, specifically, in space applications. We are presenting a new particle track and DNA damage model, in which the particle stochastic track structure is combined with the random walk (RW) structure of chromosomes in a cell nucleus. The motivation for this effort stems from the fact that the model with the RW chromosomes, NASARTI (NASA radiation track image) previously relied on amorphous track structure, while the stochastic track structure model RITRACKS (Relativistic Ion Tracks) was focused on more microscopic targets than the entire genome. We have combined chromosomes simulated by RWs with stochastic track structure, which uses nanoscopic dose calculations performed with the Monte-Carlo simulation by RITRACKS in a voxelized space. The new simulations produce the number of DSBs as function of dose and particle fluence for high-energy particles, including iron, carbon and protons, using voxels of 20 nm dimension. The combined model also calculates yields of radiation-induced CAs and unrejoined chromosome breaks in normal and repair deficient cells. The joined computational model is calibrated using the relative frequencies and distributions of chromosomal aberrations reported in the literature. The model considers fractionated deposition of energy to approximate dose rates of the space flight environment. The joined model also predicts of the yields and sizes of translocations, dicentrics, rings, and more complex-type aberrations formed in the G0/G1 cell cycle phase during the first cell division after irradiation. We found that the main advantage of the joined model is our ability to simulate small doses: 0.05-0.5 Gy. At such low doses, the stochastic track structure proved to be indispensable, as the action of individual delta-rays becomes more important.

Summary report of soil removal preliminary excavations. (Report No. ES-389-75-171)

International Nuclear Information System (INIS)

Wickland, C.E.

1975-07-01

A proposed technique to remove small areas, 2 , of contaminated soil is discussed along with the results of an actual excavation. Based on the results of a trial excavation in uncontaminated soil and an excavation of two trenches in contaminated soil, it is concluded that the techniques described are a satisfactory means of contaminated soil removal. It can be done safely with a release of airborne plutonium a factor of 10 or more below the Environmental Protection Administration (EPA) limit

An introduction to stochastic processes with applications to biology

CERN Document Server

Allen, Linda J S

2010-01-01

An Introduction to Stochastic Processes with Applications to Biology, Second Edition presents the basic theory of stochastic processes necessary in understanding and applying stochastic methods to biological problems in areas such as population growth and extinction, drug kinetics, two-species competition and predation, the spread of epidemics, and the genetics of inbreeding. Because of their rich structure, the text focuses on discrete and continuous time Markov chains and continuous time and state Markov processes.New to the Second EditionA new chapter on stochastic differential equations th

Excavating a transfer tunnel

CERN Multimedia

Laurent Guiraud

2000-01-01

The transfer tunnel being dug here will take the 450 GeV beam from the SPS and inject it into the LHC where the beam energies will be increased to 7 TeV. In order to transfer this beam from the SPS to the LHC, two transfer tunnels are used to circulate the beams in opposite directions. When excavated, the accelerator components, including magnets, beam pipes and cryogenics will be installed and connected to both the SPS and LHC ready for operation to begin in 2008.

Numerical simulation of excavation and supporting of pit slope of the pump room in XNPC

International Nuclear Information System (INIS)

Hu Mengqian; Zhu Xiuyun; Ji Zhonghua; Lu Yu; Sun Feng

2014-01-01

The research simulates the excavation and supporting of pit slope of the pump room in XNPC. According to the designing of excavation and supporting plan of slope, the numerical simulation of excavation and supporting of pit slope is conducted using the ANSYS finite element numerical simulation software. The simulation results show that, the displacement and stress caused by the excavation of above stage slope and pit slope are both small after taking some measures, including deep mixing pile reinforcement, retaining piles and prestressed anchor cable. Thus the slope is steady. (authors)

Chip shape and secondary fragmentation through TBM excavation

International Nuclear Information System (INIS)

Tsusaka, Kimikazu; Tanimoto, Chikaosa; Ueno, Takaaki; Koizumi, Yu; Nakane, Tatsuto

2008-01-01

The chips through TBM tunneling are well-known for one of useful indices to reflect the geological conditions. The flat and elongated chips whose width are equal to the spacing of cutter trace indicate the cutting face with less joints and good practice of TBM excavation with less secondary fragmentation rate. Through a case history in granitic rock, the authors proposed the new index, which is the ratio of length of major axis to thickness. Also the authors studied the relationship between the index and the excavation efficiencies. In conclusion, it was clarified that chips with the new index over 3.5 were generally observed when a TBM drove with less than 30% the secondary fragmentation rate. (author)

Modeling and stability of electro-hydraulic servo of hydraulic excavator

Science.gov (United States)

Jia, Wenhua; Yin, Chenbo; Li, Guo; Sun, Menghui

2017-11-01

The condition of the hydraulic excavator is complicated and the working environment is bad. The safety and stability of the control system is influenced by the external factors. This paper selects hydraulic excavator electro-hydraulic servo system as the research object. A mathematical model and simulation model using AMESIM of servo system is established. Then the pressure and flow characteristics are analyzed. The design and optimization of electro-hydraulic servo system and its application in engineering machinery is provided.

Detection of parasite eggs from archaeological excavations in the Republic of Korea

Directory of Open Access Journals (Sweden)

Eun-Taek Han

2003-01-01

Full Text Available Excavations at two sites dating from 2000 BC-1900 AD in southeastern areas of the Republic of Korea, revealed the remains of several structures. Examination of the contents suspected privies revealed the presence of eggs from 5 kinds of parasite: Ascaris, Trichuris, Clonorchis, and two species of unknown trematodes. Clonorchis sinensis eggs were found in a soil dating from around AD 668-935. This is the first record of C. sinensis eggs in archaeological materials in the Republic of Korea.

Non-stochastic Ti-6Al-4V foam structures with negative Poisson's ratio

Energy Technology Data Exchange (ETDEWEB)

Yang, Li, E-mail: lyang5@ncsu.edu [Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 400 Daniels Hall, 111 Lampe Drive, Raleigh, NC 27695 (United States); Cormier, Denis, E-mail: drceie@rit.edu [Department of Industrial Systems Engineering, Rochester Institute of Technology, 81 Lomb Memorial Drive, Rochester, NY 14623-5603 (United States); West, Harvey, E-mail: hawest@ncsu.edu [Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 400 Daniels Hall, 111 Lampe Drive, Raleigh, NC 27695 (United States); Harrysson, Ola, E-mail: harrysson@ncsu.edu [Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 400 Daniels Hall, 111 Lampe Drive, Raleigh, NC 27695 (United States); Knowlson, Kyle, E-mail: kyle.knowlson@gmail.com [Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, 400 Daniels Hall, 111 Lampe Drive, Raleigh, NC 27695 (United States)

2012-12-15

This paper details the design, fabrication, and testing of non-stochastic auxetic lattice lattice structures. All Ti-6Al-4V samples were created via the Electron Beam Melting (EBM) additive manufacturing process. It was found that the Poisson's ratio values significantly influence the mechanical properties of the structures. The bending properties of the auxetic samples were significantly higher than those of currently commercialized metal foams. The compressive strength was moderately higher than available metal foams. These results suggest that metallic auxetic structures have considerable promise for use in a variety of applications in which tradeoffs between mass and mechanical properties are crucial.

The huge ATLAS cavern now fully excavated

CERN Multimedia

2002-01-01

Excavation of the ATLAS cavern is now complete! At the end of two years' work involving a tremendous technical challenge, the civil engineering contractors have succeeded in digging out one of the biggest experimental caverns in the world. Bravo!

Nonlinear and stochastic dynamics of coherent structures

DEFF Research Database (Denmark)

Rasmussen, Kim

1997-01-01

This Thesis deals with nonlinear and stochastic dynamics in systems which can be described by nonlinear Schrödinger models. Basically three different models are investigated. The first is the continuum nonlinear Schröndinger model in one and two dimensions generalized by a tunable degree of nonli......This Thesis deals with nonlinear and stochastic dynamics in systems which can be described by nonlinear Schrödinger models. Basically three different models are investigated. The first is the continuum nonlinear Schröndinger model in one and two dimensions generalized by a tunable degree...... introduces the nonlinear Schrödinger model in one and two dimensions, discussing the soliton solutions in one dimension and the collapse phenomenon in two dimensions. Also various analytical methods are described. Then a derivation of the nonlinear Schrödinger equation is given, based on a Davydov like...... system described by a tight-binding Hamiltonian and a harmonic lattice coupled b y a deformation-type potential. This derivation results in a two-dimensional nonline ar Schrödinger model, and considering the harmonic lattice to be in thermal contact with a heat bath w e show that the nonlinear...

Stochastic Analysis 2010

CERN Document Server

Crisan, Dan

2011-01-01

"Stochastic Analysis" aims to provide mathematical tools to describe and model high dimensional random systems. Such tools arise in the study of Stochastic Differential Equations and Stochastic Partial Differential Equations, Infinite Dimensional Stochastic Geometry, Random Media and Interacting Particle Systems, Super-processes, Stochastic Filtering, Mathematical Finance, etc. Stochastic Analysis has emerged as a core area of late 20th century Mathematics and is currently undergoing a rapid scientific development. The special volume "Stochastic Analysis 2010" provides a sa

Excavated pulmonary nodules: an unusual clinical presentation of lung metastasis in two cases

Directory of Open Access Journals (Sweden)

Lalya Issam

2010-06-01

Full Text Available Abstract Background Excavated pulmonary metastasis are rare. We present two cases of excavated pulmonary nodules proved to be metastases from osteosarcoma and gallblader lymphoma. Case presentation The first one is 39-year-old man in whom cholecystectomy made the diagnosis of primary non-Hodgkin's lymphoma of the gallbladder. He presented in chest CT scan excavated nodules that had been biopsied and confirmed the diagnosis of non hodgkin lymphoma. He underwent 8 courses of chemotherapy CHOP 21 with complete remission. The second one is an 21 years old man who presented a right leg osteoblastic osteosarcoma with only excavated pulmonary nodules in extension assessment. He had 3 courses of polychemotherapy API (doxorubicin, platinum, and ifosfamide with partial response. Unfortunately, he died following a septic shock. Review of the literature shows that excavated pulmonary nodules as metastasis are rare but we should consider this diagnosis every time we are in front of a cancer. Chest computed tomography is the best diagnosis imaging that could make this diagnosis. Differential diagnosis between benign and malignant bullous lesions is important because surgical excision affects survival in some malignancies. Conclusions Although pulmonary nodules are the most common cancer metastasis, a differential diagnosis of a concurrent primary malignancy should always be considered every time we have excavated lesions, even in patients with known malignant disease. Thorough chest evaluation is important, as multiple primary malignancies may occur concomitantly.

Detailed measurements of deformation in the excavation disturbed zone

International Nuclear Information System (INIS)

Thompson, P.M.; Martino, J.B.; Spinney, M.H.

1993-01-01

An excavation damage extensometer (EDEX) is described. It was designed to enable detailed small-scale deformation measurements to be made in the excavation disturbed zone (EDZ) around a tunnel opening in stressed rock. Its use in the Mine-by Experiment in unfractured granitic rock at the Underground Research Laboratory (Manitoba) is described. The results obtained from an array of eight EDEX installations are presented. These demonstrate how the EDEX can be used to provide data on the EDZ which is supplementary to that obtained by larger scale borehole extensometers and a acoustic emission/micro-seismic monitoring system. (4 figures, 5 references) (UK)

Stability assessment for underground excavations and key construction techniques

CERN Document Server

Zhu, Hanhua; Zhao, Yu; Niu, Fusheng

2017-01-01

This book examines how the state of underground structures can be determined with the assistance of force, deformation and energy. It then analyzes mechanized shield methods, the New Austrian tunneling method (NATM) and conventional methods from this new perspective. The book gathers a wealth of cases reflecting the experiences of practitioners and administrators alike. Based on statistical and engineering studies of these cases, as well as lab and field experiments, it develops a stability assessment approach incorporating a stable equilibrium, which enables engineers to keep the structure and surrounding rocks safe as long as the stable equilibrium and deformation compliance are maintained. The book illustrates the implementation of the method in various tunneling contexts, including soil-rock mixed strata, tunneling beneath operating roads, underwater tunnels, and tunnel pit excavation. It offers a valuable guide for researchers, designers and engineers, especially those who are seeking to understand the u...

Report on Excavations at Sedgeford, Norfolk 1996

Directory of Open Access Journals (Sweden)

Nick Cook

1997-11-01

Full Text Available Excavations were undertaken as part of the ongoing work of the Sedgeford Hall Archaeological Research Project, which was set up in 1995 with the aim of investigating the archaeological history of the parish of Sedgeford, west Norfolk.

Investigation of Bucket Wheel Excavator Lattice Structure Internal Stress in Harsh Environment through a Remote Measurement System

Science.gov (United States)

Risteiu, M.; Dobra, R.; Andras, I.; Roventa, M.; Lorincz, A.

2017-06-01

The paper shows the results of a lab model for strain gauges based measuring system for multiple measuring heads of the mechanical stress in lattice structures of the bucket wheel excavator for open pit mines-harsh environment. The system is designed around a microcontroller system. Because of specific working conditions, the measuring system sends data to a processing system (a PC with Matlab software), we have implemented a secure communication solution based on ISM standard, by using NRF24L01 module. The transceiver contains a fully integrated frequency synthesizer based on crystal oscillator, and a Enhanced ShockBurst™ protocol engine. The proposed solution has a current consumption around 9.0 mA at an output power of -6dBm and 12.3mA in RX mode. Built-in Power Down and Standby modes makes power saving easily realizable for our solution battery powered. The stress from structures is taken by specific strain gauges adapted to low frequency vibrations. We are using a precision 24-bit analog-to-digital converter (ADC) designed for weigh scales and industrial control applications to interface directly with a bridge sensor-instrumentation device, with low drift voltage, low noise, common mode rejection signal, frequency and temperature stability. As backup implementation for measurements a high speed storage implementation is used.

Stochastic properties of the Friedman dynamical system

International Nuclear Information System (INIS)

Szydlowski, M.; Heller, M.; Golda, Z.

1985-01-01

Some mathematical aspects of the stochastic cosmology are discussed in the corresponding ordinary Friedman world models. In particulare, it is shown that if the strong and Lorentz energy conditions are known, or the potential function is given, or a stochastic measure is suitably defined then the structure of the phase plane of the Friedman dynamical system is determined. 11 refs., 2 figs. (author)

Safety analysis of autonomous excavator functionality

International Nuclear Information System (INIS)

Seward, D.; Pace, C.; Morrey, R.; Sommerville, I.

2000-01-01

This paper presents an account of carrying out a hazard analysis to define the safety requirements for an autonomous robotic excavator. The work is also relevant to the growing generic class of heavy automated mobile machinery. An overview of the excavator design is provided and the concept of a safety manager is introduced. The safety manager is an autonomous module responsible for all aspects of system operational safety, and is central to the control system's architecture. Each stage of the hazard analysis is described, i.e. system model creation, hazard definition and hazard analysis. Analysis at an early stage of the design process, and on a system that interfaces directly to an unstructured environment, exposes certain issues relevant to the application of current hazard analysis methods. The approach taken in the analysis is described. Finally, it is explained how the results of the hazard analysis have influenced system design, in particular, safety manager specifications. Conclusions are then drawn about the applicability of hazard analysis of requirements in general, and suggestions are made as to how the approach can be taken further

Transport in Stochastic Media

International Nuclear Information System (INIS)

Haran, O.; Shvarts, D.; Thieberger, R.

1998-01-01

Classical transport of neutral particles in a binary, scattering, stochastic media is discussed. It is assumed that the cross-sections of the constituent materials and their volume fractions are known. The inner structure of the media is stochastic, but there exist a statistical knowledge about the lump sizes, shapes and arrangement. The transmission through the composite media depends on the specific heterogeneous realization of the media. The current research focuses on the averaged transmission through an ensemble of realizations, frm which an effective cross-section for the media can be derived. The problem of one dimensional transport in stochastic media has been studied extensively [1]. In the one dimensional description of the problem, particles are transported along a line populated with alternating material segments of random lengths. The current work discusses transport in two-dimensional stochastic media. The phenomenon that is unique to the multi-dimensional description of the problem is obstacle bypassing. Obstacle bypassing tends to reduce the opacity of the media, thereby reducing its effective cross-section. The importance of this phenomenon depends on the manner in which the obstacles are arranged in the media. Results of transport simulations in multi-dimensional stochastic media are presented. Effective cross-sections derived from the simulations are compared against those obtained for the one-dimensional problem, and against those obtained from effective multi-dimensional models, which are partially based on a Markovian assumption

Influence of stochastic geometric imperfections on the load-carrying behaviour of thin-walled structures using constrained random fields

Science.gov (United States)

Lauterbach, S.; Fina, M.; Wagner, W.

2018-04-01

Since structural engineering requires highly developed and optimized structures, the thickness dependency is one of the most controversially debated topics. This paper deals with stability analysis of lightweight thin structures combined with arbitrary geometrical imperfections. Generally known design guidelines only consider imperfections for simple shapes and loading, whereas for complex structures the lower-bound design philosophy still holds. Herein, uncertainties are considered with an empirical knockdown factor representing a lower bound of existing measurements. To fully understand and predict expected bearable loads, numerical investigations are essential, including geometrical imperfections. These are implemented into a stand-alone program code with a stochastic approach to compute random fields as geometric imperfections that are applied to nodes of the finite element mesh of selected structural examples. The stochastic approach uses the Karhunen-Loève expansion for the random field discretization. For this approach, the so-called correlation length l_c controls the random field in a powerful way. This parameter has a major influence on the buckling shape, and also on the stability load. First, the impact of the correlation length is studied for simple structures. Second, since most structures for engineering devices are more complex and combined structures, these are intensively discussed with the focus on constrained random fields for e.g. flange-web-intersections. Specific constraints for those random fields are pointed out with regard to the finite element model. Further, geometrical imperfections vanish where the structure is supported.

Problems of Mathematical Finance by Stochastic Control Methods

Science.gov (United States)

Stettner, Łukasz

The purpose of this paper is to present main ideas of mathematics of finance using the stochastic control methods. There is an interplay between stochastic control and mathematics of finance. On the one hand stochastic control is a powerful tool to study financial problems. On the other hand financial applications have stimulated development in several research subareas of stochastic control in the last two decades. We start with pricing of financial derivatives and modeling of asset prices, studying the conditions for the absence of arbitrage. Then we consider pricing of defaultable contingent claims. Investments in bonds lead us to the term structure modeling problems. Special attention is devoted to historical static portfolio analysis called Markowitz theory. We also briefly sketch dynamic portfolio problems using viscosity solutions to Hamilton-Jacobi-Bellman equation, martingale-convex analysis method or stochastic maximum principle together with backward stochastic differential equation. Finally, long time portfolio analysis for both risk neutral and risk sensitive functionals is introduced.

Simulations of DSB Yields and Radiation-induced Chromosomal Aberrations in Human Cells Based on the Stochastic Track Structure iIduced by HZE Particles

Science.gov (United States)

Ponomarev, Artem; Plante, Ianik; George, Kerry; Wu, Honglu

2014-01-01

The formation of double-strand breaks (DSBs) and chromosomal aberrations (CAs) is of great importance in radiation research and, specifically, in space applications. We are presenting a new particle track and DNA damage model, in which the particle stochastic track structure is combined with the random walk (RW) structure of chromosomes in a cell nucleus. The motivation for this effort stems from the fact that the model with the RW chromosomes, NASARTI (NASA radiation track image) previously relied on amorphous track structure, while the stochastic track structure model RITRACKS (Relativistic Ion Tracks) was focused on more microscopic targets than the entire genome. We have combined chromosomes simulated by RWs with stochastic track structure, which uses nanoscopic dose calculations performed with the Monte-Carlo simulation by RITRACKS in a voxelized space. The new simulations produce the number of DSBs as function of dose and particle fluence for high-energy particles, including iron, carbon and protons, using voxels of 20 nm dimension. The combined model also calculates yields of radiation-induced CAs and unrejoined chromosome breaks in normal and repair deficient cells. The joined computational model is calibrated using the relative frequencies and distributions of chromosomal aberrations reported in the literature. The model considers fractionated deposition of energy to approximate dose rates of the space flight environment. The joined model also predicts of the yields and sizes of translocations, dicentrics, rings, and more complex-type aberrations formed in the G0/G1 cell cycle phase during the first cell division after irradiation. We found that the main advantage of the joined model is our ability to simulate small doses: 0.05-0.5 Gy. At such low doses, the stochastic track structure proved to be indispensable, as the action of individual delta-rays becomes more important.

Archeological Excavations at the Wanapum Cache Site

International Nuclear Information System (INIS)

T. E. Marceau

2000-01-01

This report was prepared to document the actions taken to locate and excavate an abandoned Wanapum cache located east of the 100-H Reactor area. Evidence (i.e., glass, ceramics, metal, and wood) obtained from shovel and backhoe excavations at the Wanapum cache site indicate that the storage caches were found. The highly fragmented condition of these materials argues that the contents of the caches were collected or destroyed prior to the caches being burned and buried by mechanical equipment. While the fiber nets would have been destroyed by fire, the specialized stone weights would have remained behind. The fact that the site might have been gleaned of desirable artifacts prior to its demolition is consistent with the account by Riddell (1948) for a contemporary village site. Unfortunately, fishing equipment, owned by and used on behalf of the village, that might have returned to productive use has been irretrievably lost

Excavating and loading equipment for peat mining

Science.gov (United States)

Mikhailov, A. V.; Zhigulskaya, A. I.; Yakonovskaya, T. B.

2017-10-01

Recently, the issues of sustainable development of Russian regions, related to ensuring energy security, are more urgent than ever. To achieve sustainable development, an integrated approach to the use of local natural resources is needed. Practically in all north regions of the Russian Federation, peat as a local natural resource is widespread, which has a practical application in the area of housing services. The paper presents the evaluation of technologies for open-pit peat mining, as well as analysis of technological equipment for peat production. Special attention is paid to a question of peat materials excavating and loading. The problem of equipment selection in a peat surface mine is complex. Many features, restrictions and criteria need to be considered. Use of low and ultra-low ground pressure excavators and low ground pressure front-end loaders with full-range tires to provide the necessary floatation in the peat bog environment is offered.

Dilmun revisited: excavations at Saar, Bahrain

Directory of Open Access Journals (Sweden)

Harriet Crawford

1997-11-01

Full Text Available About 2000 BC the island of Bahrain was at the centre of a prosperous trading community - the Early Dilmun civilization - that stretched from Mesopotamia to the Indus Valley. Excavations at the site of Saar have, since 1989, recovered much new information about the layout of the settlement and its local economy and social system.

Stochastic geometry and its applications

CERN Document Server

Chiu, Sung Nok; Kendall, Wilfrid S; Mecke, Joseph

2013-01-01

An extensive update to a classic text Stochastic geometry and spatial statistics play a fundamental role in many modern branches of physics, materials sciences, engineering, biology and environmental sciences. They offer successful models for the description of random two- and three-dimensional micro and macro structures and statistical methods for their analysis. The previous edition of this book has served as the key reference in its field for over 18 years and is regarded as the best treatment of the subject of stochastic geometry, both as a subject with vital a

Simulation and inference for stochastic processes with YUIMA a comprehensive R framework for SDEs and other stochastic processes

CERN Document Server

Iacus, Stefano M

2018-01-01

The YUIMA package is the first comprehensive R framework based on S4 classes and methods which allows for the simulation of stochastic differential equations driven by Wiener process, Lévy processes or fractional Brownian motion, as well as CARMA processes. The package performs various central statistical analyses such as quasi maximum likelihood estimation, adaptive Bayes estimation, structural change point analysis, hypotheses testing, asynchronous covariance estimation, lead-lag estimation, LASSO model selection, and so on. YUIMA also supports stochastic numerical analysis by fast computation of the expected value of functionals of stochastic processes through automatic asymptotic expansion by means of the Malliavin calculus. All models can be multidimensional, multiparametric or non parametric.The book explains briefly the underlying theory for simulation and inference of several classes of stochastic processes and then presents both simulation experiments and applications to real data. Although these ...

Roles of dispersal, stochasticity, and nonlinear dynamics in the spatial structuring of seasonal natural enemy-victim populations

Science.gov (United States)

Patrick C. Tobin; Ottar N. Bjornstad

2005-01-01

Natural enemy-victim systems may exhibit a range of dynamic space-time patterns. We used a theoretical framework to study spatiotemporal structuring in a transient natural enemy-victim system subject to differential rates of dispersal, stochastic forcing, and nonlinear dynamics. Highly mobile natural enemies that attacked less mobile victims were locally spatially...

Design Of Combined Stochastic Feedforward/Feedback Control

Science.gov (United States)

Halyo, Nesim

1989-01-01

Methodology accommodates variety of control structures and design techniques. In methodology for combined stochastic feedforward/feedback control, main objectives of feedforward and feedback control laws seen clearly. Inclusion of error-integral feedback, dynamic compensation, rate-command control structure, and like integral element of methodology. Another advantage of methodology flexibility to develop variety of techniques for design of feedback control with arbitrary structures to obtain feedback controller: includes stochastic output feedback, multiconfiguration control, decentralized control, or frequency and classical control methods. Control modes of system include capture and tracking of localizer and glideslope, crab, decrab, and flare. By use of recommended incremental implementation, control laws simulated on digital computer and connected with nonlinear digital simulation of aircraft and its systems.

Stochastic Gravity: Theory and Applications

Directory of Open Access Journals (Sweden)

Hu Bei Lok

2008-05-01

Full Text Available Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein–Langevin equation, which has, in addition, sources due to the noise kernel. The noise kernel is the vacuum expectation value of the (operator-valued stress-energy bitensor, which describes the fluctuations of quantum-matter fields in curved spacetimes. A new improved criterion for the validity of semiclassical gravity may also be formulated from the viewpoint of this theory. In the first part of this review we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity, showing the link from the mean value of the stress-energy tensor to the correlation functions. The functional approach uses the Feynman–Vernon influence functional and the Schwinger–Keldysh closed-time-path effective action methods. In the second part, we describe three applications of stochastic gravity. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic-gravity viewpoint, which can go beyond the standard treatment by incorporating the full quantum effect of the inflaton fluctuations. Third, using the Einstein–Langevin equation, we discuss the backreaction of Hawking radiation and the behavior of metric fluctuations for both the quasi-equilibrium condition of a black-hole in a box and the fully nonequilibrium condition of an evaporating black hole spacetime. Finally, we briefly discuss the theoretical structure of stochastic gravity in relation to quantum gravity and point out

Fuzzy mathematics method for theoretical analysis of ground movements due to underground excavation

Energy Technology Data Exchange (ETDEWEB)

Li Wenxiu (Changsa Research Institute of Mining and Metallurgy, Changsa (China))

1991-07-01

The analysis of the rock mass movements due to excavation operations is one of the many important problems of rock mass mechanics. It is difficult to calculate the ground movements due to underground excavation accurately because of the complexity of the problem. In this paper, the application is described of the fuzzy probability measures to the analysis of ground movements. Based on the definition of the fuzzy probability measure, the theories for both the two-dimensional and three-dimensional problems are developed and are applied to the analysis of ground movements due to underground excavation. 31 refs., 5 figs.

Excavations at Pukearuhe (N99/49), North Taranaki, 1968

International Nuclear Information System (INIS)

Lawrence, J.; Prickett, N.

1984-01-01

The 1968 salvage excavations at Pukearuhe (N99/49), north Taranaki, are reported. Pukearuhe was for long a Ngati Tama fortification; in the period 1865-1885 it was occupied by european forces, firstly, imperial troops and Taranaki military settlers, later, armed constabulary. Ngati Tama and european occupation was based on the powerful strategic situation of Pukearuhe at the northern gateway into Taranaki. Excavations revealed evidence of the Maori and European occupation. Radiocarbon dates were obtained for Maori occupation. European material adds to the knowledge of sites relating to the period of military conflict in Taranaki which extended from 1860 to the early 1880s

Geotechnical characterization and construction methods for SSC tunnel excavation

International Nuclear Information System (INIS)

Nelson, P.P.; Lundin, T.K.

1990-06-01

The site for the Superconducting Super Collider (SSC) facility was selected in 1988 after a nationwide proposal competition. The selected site is located in Ellis County, Texas, surrounding the town of Waxahachie which is about 30 miles (48 km) south of the City of Dallas central business district. This paper will describe the geotechnical conditions anticipated for excavation at the SSC site. A general geologic and geomechanical description of the rock present will be followed by a summary of the site-specific conceptual design for the tunneled components of the SSC machine. The Supercollider project will include about 70 miles (113) km of tunnel excavation

Alternative cytoskeletal landscapes: cytoskeletal novelty and evolution in basal excavate protists

Science.gov (United States)

Dawson, Scott C.; Paredez, Alexander R.

2016-01-01

Microbial eukaryotes encompass the majority of eukaryotic evolutionary and cytoskeletal diversity. The cytoskeletal complexity observed in multicellular organisms appears to be an expansion of components present in genomes of diverse microbial eukaryotes such as the basal lineage of flagellates, the Excavata. Excavate protists have complex and diverse cytoskeletal architectures and life cycles – essentially alternative cytoskeletal “landscapes” – yet still possess conserved microtubule- and actin-associated proteins. Comparative genomic analyses have revealed that a subset of excavates, however, lack many canonical actin-binding proteins central to actin cytoskeleton function in other eukaryotes. Overall, excavates possess numerous uncharacterized and “hypothetical” genes, and may represent an undiscovered reservoir of novel cytoskeletal genes and cytoskeletal mechanisms. The continued development of molecular genetic tools in these complex microbial eukaryotes will undoubtedly contribute to our overall understanding of cytoskeletal diversity and evolution. PMID:23312067

Choice of rock excavation methods for the Swedish deep repository for spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Baeckblom, Goeran [Conrox, Stockholm (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Lagerstedt, Leif [SwedPower AB, Stockholm (Sweden)

2004-09-01

Choice of rock excavation methods will or may have implications for a number of issues like repository layout, long term and operational safety, environmental impact, design of and operation of transport vehicles and methodology for backfilling the repository before closure as well as effects on costs and schedules. To fully analyse the issues at hand related to selection of excavation methods, SKB organized a project with the objectives: To investigate and compare principal technical solutions for rock excavation, both methods that are used at present but also methods that may be feasible 10 years from now; To assess how the selection of excavation method influences the design and operation of the deep repository; To present a definition of the Excavation Damaged/Disturbed Zone and practical methods for measurements of EDZ; To present advantages and disadvantages with different excavation methods for the various tunnels and underground openings as a basis for selection of preferred excavation methods; To present the Design Justification Statement for the selection of particular excavation methods for the different tunnels and openings in the deep repository to underpin a decision on excavation method; and To present background data that may be required for the evaluation of the long term safety of the deep repository. Main alternatives studied are very smooth blasting, excavation with a tunnel-boring machine (TBM) and excavation with horizontal pull-reaming using more or less conventional raise-boring equipment. The detailed studies were carried through in co-operation with major suppliers and end-users of the technology. An observation in this study is that all excavation technologies are mature; no major breakthroughs are foreseen within a 10 year period but it is likely that for any technology selected, SKB would specifically fine-tune the design of the equipment and work procedures in view of requirements and site specific conditions. Excavation methods have

Choice of rock excavation methods for the Swedish deep repository for spent nuclear fuel

International Nuclear Information System (INIS)

Baeckblom, Goeran; Christiansson, Rolf; Lagerstedt, Leif

2004-09-01

Choice of rock excavation methods will or may have implications for a number of issues like repository layout, long term and operational safety, environmental impact, design of and operation of transport vehicles and methodology for backfilling the repository before closure as well as effects on costs and schedules. To fully analyse the issues at hand related to selection of excavation methods, SKB organized a project with the objectives: To investigate and compare principal technical solutions for rock excavation, both methods that are used at present but also methods that may be feasible 10 years from now; To assess how the selection of excavation method influences the design and operation of the deep repository; To present a definition of the Excavation Damaged/Disturbed Zone and practical methods for measurements of EDZ; To present advantages and disadvantages with different excavation methods for the various tunnels and underground openings as a basis for selection of preferred excavation methods; To present the Design Justification Statement for the selection of particular excavation methods for the different tunnels and openings in the deep repository to underpin a decision on excavation method; and To present background data that may be required for the evaluation of the long term safety of the deep repository. Main alternatives studied are very smooth blasting, excavation with a tunnel-boring machine (TBM) and excavation with horizontal pull-reaming using more or less conventional raise-boring equipment. The detailed studies were carried through in co-operation with major suppliers and end-users of the technology. An observation in this study is that all excavation technologies are mature; no major breakthroughs are foreseen within a 10 year period but it is likely that for any technology selected, SKB would specifically fine-tune the design of the equipment and work procedures in view of requirements and site specific conditions. Excavation methods have

Excavation-caused extra deformation of existing masonry residence in soft soil region

Science.gov (United States)

Tang, Y.; Franceschelli, S.

2017-04-01

Growing need for construction of infrastructures and buildings in fast urbanization process creates challenges of interaction between buildings under construction and adjacent existing buildings. This paper presents the mitigation of contradiction between two parties who are involved the interaction using civil engineering techniques. Through the in-depth analysis of the results of monitoring surveys and enhanced accuracy and reliability of surveys, a better understanding of the behavior of deformable buildings is achieved. Combination with the original construction documents, the two parties agree that both of them are responsible for building damages and a better understanding for the rehabilitation of the existing buildings is focused on. Two cases studies are used to demonstrate and describe the importance of better understanding of the behavior of existing buildings and their rehabilitations. The objective of this study is to insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations, which can result in a damage in existing masonry residence, and to take the optimized measures to make deep excavations safety and economic and adjacent buildings keep good serviceability in urban areas with soft soil conditions.

Uncertainty Reduction for Stochastic Processes on Complex Networks

Science.gov (United States)

Radicchi, Filippo; Castellano, Claudio

2018-05-01

Many real-world systems are characterized by stochastic dynamical rules where a complex network of interactions among individual elements probabilistically determines their state. Even with full knowledge of the network structure and of the stochastic rules, the ability to predict system configurations is generally characterized by a large uncertainty. Selecting a fraction of the nodes and observing their state may help to reduce the uncertainty about the unobserved nodes. However, choosing these points of observation in an optimal way is a highly nontrivial task, depending on the nature of the stochastic process and on the structure of the underlying interaction pattern. In this paper, we introduce a computationally efficient algorithm to determine quasioptimal solutions to the problem. The method leverages network sparsity to reduce computational complexity from exponential to almost quadratic, thus allowing the straightforward application of the method to mid-to-large-size systems. Although the method is exact only for equilibrium stochastic processes defined on trees, it turns out to be effective also for out-of-equilibrium processes on sparse loopy networks.

Stochastic population oscillations in spatial predator-prey models

International Nuclear Information System (INIS)

Taeuber, Uwe C

2011-01-01

It is well-established that including spatial structure and stochastic noise in models for predator-prey interactions invalidates the classical deterministic Lotka-Volterra picture of neutral population cycles. In contrast, stochastic models yield long-lived, but ultimately decaying erratic population oscillations, which can be understood through a resonant amplification mechanism for density fluctuations. In Monte Carlo simulations of spatial stochastic predator-prey systems, one observes striking complex spatio-temporal structures. These spreading activity fronts induce persistent correlations between predators and prey. In the presence of local particle density restrictions (finite prey carrying capacity), there exists an extinction threshold for the predator population. The accompanying continuous non-equilibrium phase transition is governed by the directed-percolation universality class. We employ field-theoretic methods based on the Doi-Peliti representation of the master equation for stochastic particle interaction models to (i) map the ensuing action in the vicinity of the absorbing state phase transition to Reggeon field theory, and (ii) to quantitatively address fluctuation-induced renormalizations of the population oscillation frequency, damping, and diffusion coefficients in the species coexistence phase.

Stochastic and non-stochastic effects - a conceptual analysis

International Nuclear Information System (INIS)

Karhausen, L.R.

1980-01-01

The attempt to divide radiation effects into stochastic and non-stochastic effects is discussed. It is argued that radiation or toxicological effects are contingently related to radiation or chemical exposure. Biological effects in general can be described by general laws but these laws never represent a necessary connection. Actually stochastic effects express contingent, or empirical, connections while non-stochastic effects represent semantic and non-factual connections. These two expressions stem from two different levels of discourse. The consequence of this analysis for radiation biology and radiation protection is discussed. (author)

Minimum uncertainty and squeezing in diffusion processes and stochastic quantization

Science.gov (United States)

Demartino, S.; Desiena, S.; Illuminati, Fabrizo; Vitiello, Giuseppe

1994-01-01

We show that uncertainty relations, as well as minimum uncertainty coherent and squeezed states, are structural properties for diffusion processes. Through Nelson stochastic quantization we derive the stochastic image of the quantum mechanical coherent and squeezed states.

Stochastic inflation in phase space: is slow roll a stochastic attractor?

Energy Technology Data Exchange (ETDEWEB)

Grain, Julien [Institut d' Astrophysique Spatiale, UMR8617, CNRS, Univ. Paris Sud, Université Paris-Saclay, Bt. 121, Orsay, F-91405 (France); Vennin, Vincent, E-mail: julien.grain@ias.u-psud.fr, E-mail: vincent.vennin@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO13FX (United Kingdom)

2017-05-01

An appealing feature of inflationary cosmology is the presence of a phase-space attractor, ''slow roll'', which washes out the dependence on initial field velocities. We investigate the robustness of this property under backreaction from quantum fluctuations using the stochastic inflation formalism in the phase-space approach. A Hamiltonian formulation of stochastic inflation is presented, where it is shown that the coarse-graining procedure—where wavelengths smaller than the Hubble radius are integrated out—preserves the canonical structure of free fields. This means that different sets of canonical variables give rise to the same probability distribution which clarifies the literature with respect to this issue. The role played by the quantum-to-classical transition is also analysed and is shown to constrain the coarse-graining scale. In the case of free fields, we find that quantum diffusion is aligned in phase space with the slow-roll direction. This implies that the classical slow-roll attractor is immune to stochastic effects and thus generalises to a stochastic attractor regardless of initial conditions, with a relaxation time at least as short as in the classical system. For non-test fields or for test fields with non-linear self interactions however, quantum diffusion and the classical slow-roll flow are misaligned. We derive a condition on the coarse-graining scale so that observational corrections from this misalignment are negligible at leading order in slow roll.

118-B-1 excavation treatability test plan

International Nuclear Information System (INIS)

1994-07-01

The Hanford 118-B-1 Burial Ground Treatability Study has been required by milestone change request number-sign M-15-93-04, dated September 30, 1993. The change request requires that a treatability test be conducted at the 100-B Area to obtain additional engineering information for remedial design of burial grounds receiving waste from 100 Area removal actions. This treatability study has two purposes: (1) to support development of the Proposed Plan (PP) and Record of Decision (ROD), which will identify the approach to be used for burial ground remediation, and (2) to provide specific engineering information for receiving waste generated from the 100 Area removal actions. Data generated from this test also will provide critical performance and cost information necessary for remedy evaluation in the detailed analysis of alternatives during preparation of the focused feasibility study (FFS). This treatability testing supports the following 100 Area alternatives: (1) excavation and disposal, and (2) excavation, sorting, (treatment), and disposal

Stochastic solution of population balance equations for reactor networks

International Nuclear Information System (INIS)

Menz, William J.; Akroyd, Jethro; Kraft, Markus

2014-01-01

This work presents a sequential modular approach to solve a generic network of reactors with a population balance model using a stochastic numerical method. Full-coupling to the gas-phase is achieved through operator-splitting. The convergence of the stochastic particle algorithm in test networks is evaluated as a function of network size, recycle fraction and numerical parameters. These test cases are used to identify methods through which systematic and statistical error may be reduced, including by use of stochastic weighted algorithms. The optimal algorithm was subsequently used to solve a one-dimensional example of silicon nanoparticle synthesis using a multivariate particle model. This example demonstrated the power of stochastic methods in resolving particle structure by investigating the transient and spatial evolution of primary polydispersity, degree of sintering and TEM-style images. Highlights: •An algorithm is presented to solve reactor networks with a population balance model. •A stochastic method is used to solve the population balance equations. •The convergence and efficiency of the reported algorithms are evaluated. •The algorithm is applied to simulate silicon nanoparticle synthesis in a 1D reactor. •Particle structure is reported as a function of reactor length and time

Stochasticity and determinism in models of hematopoiesis.

Science.gov (United States)

Kimmel, Marek

2014-01-01

This chapter represents a novel view of modeling in hematopoiesis, synthesizing both deterministic and stochastic approaches. Whereas the stochastic models work in situations where chance dominates, for example when the number of cells is small, or under random mutations, the deterministic models are more important for large-scale, normal hematopoiesis. New types of models are on the horizon. These models attempt to account for distributed environments such as hematopoietic niches and their impact on dynamics. Mixed effects of such structures and chance events are largely unknown and constitute both a challenge and promise for modeling. Our discussion is presented under the separate headings of deterministic and stochastic modeling; however, the connections between both are frequently mentioned. Four case studies are included to elucidate important examples. We also include a primer of deterministic and stochastic dynamics for the reader's use.

Case Studies and Monitoring of Deep Excavations

NARCIS (Netherlands)

Korff, M.

2017-01-01

Several case histories from Dutch underground deep excavation projects are presented in this paper, including the lessons learned and the learning processes involved. The focus of the paper is on how the learning takes places and how it is documented. It is necessary to learn in a systematic and

ROCK MASS DAMAGED ZONE CAUSED BY BLASTING DURING TUNNEL EXCAVATION

Directory of Open Access Journals (Sweden)

Hrvoje Antičević

2012-07-01

Full Text Available Design of underground spaces, including tunnels, and repositories for radioactive waste include the application of the same or similar technologies. Tunnel excavation by blasting inevitably results in the damage in the rock mass around the excavation profile. The damage in the rock mass immediately next to the tunnel profile emerges as the expanding of the existing cracks and the appearance of new cracks, i.e. as the change of the physical and-mechanical properties of the rock mass. Concerning the design of deep geological repositories, requirements in terms of damaged rock are the same or more rigorous than for the design of tunnel. The aforementioned research is directed towards determining the depth of damage zone caused by blasting. The depth of the damage zone is determined by measuring the changes of physical and-mechanical properties of the rock mass around the tunnel excavation profile. By this research the drilling and blasting parameters were correlated with the depth and size of the damage zone (the paper is published in Croatian.

Geological mappability of bored versus drill and blast excavations for radioactive waste repositories

International Nuclear Information System (INIS)

Nilsen, B.; Ozdemir, L.

1992-01-01

The issue of accurate geological mappability has been subject of intense debate in the selection of bored versus drill and blast excavation for radioactive waste repositories. This paper is intended to provide an assessment of the problems usually encountered in mappability on the basis of field experience from a large number of completed tunnels, mainly as part of the Norwegian hydropower projects. The main conclusion is that mapping in a mechanically excavated underground opening, with very few exceptions, reflects the in-situ conditions more accurately than mapping in a drill and blast tunnel. This is due to the overbreak effects of drill and blast excavation, primarily

Technical summary of AECL's Mine-by Experiment phase I: Excavation response

International Nuclear Information System (INIS)

Read, R.S.; Martin, C.D.

1996-02-01

The first phase of the Mine-by Experiment was conducted at the 420 Level of the Underground Research Laboratory (URL) to investigate the response induced in the rock mass by excavating a 3.5-m-diameter circular tunnel using a non-explosive technique. The main objective of the experiment was to study the processes involved in progressive failure and the development of excavation-induced damage around underground openings. To this end, state-of-the-art geomechanical and geophysical instrumentation was used to monitor the excavation of the 46-m-long Mine-by Experiment test tunnel. The results from the experiment show that progressive failure in compressive regions around the tunnel initiates at stresses about 50% of the rock strength measured in uniaxial compression tests in the laboratory. The difference between the laboratory and in situ behaviour is attributed to complex stress changes that occur during excavation of the tunnel, especially in the vicinity of the advancing face. These effects are not simulated in standard laboratory tests. Numerical modelling and in situ characterization studies were conducted to establish the extent and characteristics of the damaged zone around the test tunnel. As part of this study, in situ stresses and material properties were established through back analysis of measured displacements and strains. Using these boundary conditions, it was shown that the damaged zone was limited to within 1 m of the original tunnel perimeter. The characteristics of the damaged zone, however, were found to be highly variable around the tunnel, and were dependent on the nature of the stress concentrations, geology, stress magnitudes and orientations and, to a lesser extent, the excavation method and sequence. (author) 136 refs., 14 tabs., 103 figs

Excavation damage and organic growth in a 1.2m diameter borehole

International Nuclear Information System (INIS)

Everitt, R.A.; Gann, P.; Brown, D.A.; Boychuk, D.M.

1994-01-01

A 1.24m diameter borehole was drilled 5m into the floor of a typical drill-and-blast tunnel in unfractured granite, at AECL's Underground Research Laboratory. Three generations of excavation damage, characteristic of what may be encountered in boreholes excavated for in-hole emplacement of used fuel wastes was observed. These include: (1) damage related to the initial excavation of the room, (2) damage caused by the drilling of the borehole itself, and (3) damage due to subsequent stress-induced spalling of the borehole walls. A biofilm containing a variety of microorganisms has developed where seepage issues from the concrete-granite interface. The biota were introduced from surface water used for mining and drilling. Their growth has been stimulated by residues from blasting and drilling, which have concentrated iron and silicon by passive sorption and energy metabolism. Ferrous iron has been oxidized and precipitated as ferrihydrite/hematite to give an orange/brown colouration on the biofilm interface black. These observations, significant to the understanding and monitoring of excavation damage, highlight the importance of thorough, in situ, multi-disciplinary characterization for vault design

Dam geology and basic treatment(2). Adit substitution technique and measures against landslide involved in excavation

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Kin' ichi [Kinki Geological Center, Co. Ltd., Kyoto, Japan (JP)

1988-12-25

This paper discusses the adit substitution technique which is a method for special treatment of dams and measures against landslide involved in excavation. The adit substitution technique consists of excavating an adit in the natural ground, excavating another adit which is in contact with the first adit and is at a level higher than the first adit, placing concrete from the upper adit to the lower adit to fill first adit completely with concrete, excavating a third adit, filling the second adit with concrete similarly, and proceeding with this process to construct a water barrier within the natural ground until the water barrier reaches the required height. The paper explains examples of this technique used on four dams. It also explains examples of measures against excavation-induced landslide adopted on three dams. 13 refs., 8 figs., 2 tabs.

Reliability-Based Shape Optimization using Stochastic Finite Element Methods

DEFF Research Database (Denmark)

Enevoldsen, Ib; Sørensen, John Dalsgaard; Sigurdsson, G.

1991-01-01

stochastic fields (e.g. loads and material parameters such as Young's modulus and the Poisson ratio). In this case stochastic finite element techniques combined with FORM analysis can be used to obtain measures of the reliability of the structural systems, see Der Kiureghian & Ke (6) and Liu & Der Kiureghian...

Zedex - an in-situ study of the importance of the excavation disturbed zone to repository performance

International Nuclear Information System (INIS)

Olsson, O.; Slimane K.B.; Davies, N.

1995-01-01

The excavation of shafts and tunnels in a waste repository will cause a disturbance to the surrounding rock mass with possible alterations to rock mass stability and hydraulic properties. The properties and extent of the disturbed zone must be considered in the design of a repository and in the assessment of its long-term safety. In addition, the data collected in drifts, which will be used for detailed characterization of the repository, will be affected by excavation effects. ANDRA, UK Nirex, and SKB have jointly set up the ZEDEX Project at the Aespoe Hard Rock Laboratory, Sweden, in order to improve understanding of the properties and extent the Excavation Disturbed Zone (EDZ). The main objective is to study the mechanical behavior of the EDZ with respect to its origin, character, magnitude of property change, extent, and its dependence of excavation method. The project will also provide a test of equipment and methodology for quantifying the EDZ. The ZEDEX Project includes tests of open-quote normal close-quote excavation by drill and blast, a smooth blasting procedure based on low shock explosives, and excavation by tunnel boring. The ZEDEX Project is still in progress and results have not been fully analyzed. The preliminary analysis of the results indicates that the measurable changes in properties induced by tunnel excavation are comparatively small

The Montana ALE (Autonomous Lunar Excavator) Systems Engineering Report

Science.gov (United States)

Hull, Bethanne J.

2012-01-01

On May 2 1-26, 20 12, the third annual NASA Lunabotics Mining Competition will be held at the Kennedy Space Center in Florida. This event brings together student teams from universities around the world to compete in an engineering challenge. Each team must design, build and operate a robotic excavator that can collect artificial lunar soil and deposit it at a target location. Montana State University, Bozeman, is one of the institutions selected to field a team this year. This paper will summarize the goals of MSU's lunar excavator project, known as the Autonomous Lunar Explorer (ALE), along with the engineering process that the MSU team is using to fulfill these goals, according to NASA's systems engineering guidelines.

Hydraulic tests for the Excavation Disturbed Zone in NATM drift of North Extension

International Nuclear Information System (INIS)

Matsuoka, Eiken

1997-03-01

Investigation for characterization of rock properties of the Excavation Disturbed Zone (EDZ) were carried out in NATM drift of North Extension in the Tono Mine. As a part of this investigation, hydraulic tests were performed by means of the hydraulic measuring instrument, which had been developed by PNC Tono Geoscience Center. The purpose of this tests is to characterize the change in hydraulic properties of the EDZ caused by drift excavation using machine (boom header). The hydraulic tests were performed in the burials MH-1,2,3, in which hydraulic tests had been performed before the drift excavation in 1994. The test results indicate that the measured values of pore water pressure have decreased after excavation of the drift. The values ranged from -0.037 kgf/cm 2 to 0.039 kgf/cm 2 . The measured hydraulic conductivities ranged from 2.2*10 -11 cm/s to 9.1*10 -11 cm/s for mud stone and from 2.8*10 -9 cm/s to 2.4*10 -7 cm/s for conglomerate. The measured hydraulic conductivities for mud stone are below the lower limit of the instrument, and the change in the hydraulic conductivities for conglomerate is little. The hydraulic conductivities for conglomerate and mad stone (reference values) are interpreted. The change in hydraulic conductivities measured before and after excavation of the drift is insignificant. (author)

Stochastic dynamics of new inflation

International Nuclear Information System (INIS)

Nakao, Ken-ichi; Nambu, Yasusada; Sasaki, Misao.

1988-07-01

We investigate thoroughly the dynamics of an inflation-driving scalar field in terms of an extended version of the stochastic approach proposed by Starobinsky and discuss the spacetime structure of the inflationary universe. To avoid any complications which might arise due to quantum gravity, we concentrate our discussions on the new inflationary universe scenario in which all the energy scales involved are well below the planck mass. The investigation is done both analytically and numerically. In particular, we present a full numerical analysis of the stochastic scalar field dynamics on the phase space. Then implications of the results are discussed. (author)

Uncertainty calculation for modal parameters used with stochastic subspace identification: an application to a bridge structure

Science.gov (United States)

Hsu, Wei-Ting; Loh, Chin-Hsiung; Chao, Shu-Hsien

2015-03-01

Stochastic subspace identification method (SSI) has been proven to be an efficient algorithm for the identification of liner-time-invariant system using multivariate measurements. Generally, the estimated modal parameters through SSI may be afflicted with statistical uncertainty, e.g. undefined measurement noises, non-stationary excitation, finite number of data samples etc. Therefore, the identified results are subjected to variance errors. Accordingly, the concept of the stabilization diagram can help users to identify the correct model, i.e. through removing the spurious modes. Modal parameters are estimated at successive model orders where the physical modes of the system are extracted and separated from the spurious modes. Besides, an uncertainty computation scheme was derived for the calculation of uncertainty bounds for modal parameters at some given model order. The uncertainty bounds of damping ratios are particularly interesting, as the estimation of damping ratios are difficult to obtain. In this paper, an automated stochastic subspace identification algorithm is addressed. First, the identification of modal parameters through covariance-driven stochastic subspace identification from the output-only measurements is used for discussion. A systematic way of investigation on the criteria for the stabilization diagram is presented. Secondly, an automated algorithm of post-processing on stabilization diagram is demonstrated. Finally, the computation of uncertainty bounds for each mode with all model order in the stabilization diagram is utilized to determine system natural frequencies and damping ratios. Demonstration of this study on the system identification of a three-span steel bridge under operation condition is presented. It is shown that the proposed new operation procedure for the automated covariance-driven stochastic subspace identification can enhance the robustness and reliability in structural health monitoring.

Mine-by experiment committee report phase 1: excavation response summary and implications

International Nuclear Information System (INIS)

Martin, C.D.; Kaiser, P.K.

1996-05-01

The first phase of the Mine-by Experiment, i.e., excavation of a 3.5-m-diameter tunnel, was carried out at the 420 Level of the Underground Research Laboratory to investigate rock mass damage and progressive failure around a circular opening in brittle unfractitred Lac du Bonnet granite. The tunnel was excavated without explosives, and state-of-the-art instrumentation comprising both geomechanical and geophysical instruments was used to monitor the failure process. The experiment showed that rock mass damage begins once the deviatoric stress (0'1 - 0'3) near the advancing face of the tunnel exceeds a critical level. Crack propagation can lead to progressive failure around the tunnel; however, it is limited to a region, referred to as the excavation damaged zone, of less than one tunnel radius. Within the damaged zone, stabbing (a typical form of brittle failure) began at stress levels equivalent to about 50% of the short-term laboratory unconfined compressive strength. This reduction in strength between laboratory and in situ conditions occurs because the in situ loading path is far more complex than the monotonic loading path used to test laboratory samples. There is no evidence to suggest that the stabbing failure process would extend beyond the depth of damage defined by the deviatoric stress criterion. The stabbing process stops when the tunnel face has advanced sufficiently (approximately 2 tunnel diameters) such that the rock mass is no longer subjected to excavation-induced stress changes. The strength of the rock mass in the damaged zone must be back-calculated from in situ tests, because the loading path cannot be duplicated readily in the laboratory. Thus, the back-calculated damaged strength must be used to evaluate the stability of the excavation. Sealing systems to reduce the permeability in the axial direction of a tunnel must be keyed into the rock mass beyond the radial extent of the damaged zone. The shape of the seals must be designed so as to

A low-cost approach for the documentation and monitoring of an archaeological excavation site

Science.gov (United States)

Hoffmeister, Dirk; Orrin, Joel; Richter, Jürgen

2016-04-01

The documentation of archaeological excavations and in particular a constant monitoring is often time-consuming and depending on humańs capabilities. Thus, remote sensing methods, which allow an objective reproduction of the current state of an excavation and additional information are of interest. Therefore, a low-cost approach was tested on an open-air excavation site for two days in September 2015. The Magdalenian excavation site of Bad Kösen-Lengefeld, Germany is one important site in a system of about 100 sites in the area of the small rivers Saale and Unstrut. The whole site and the surrounding area (200 by 200 m) was first observed by a GoPro Hero 3+ mounted on a DJI-Phantom 2 UAV. Ground control points were set-up in a regular grid covering the whole area. The achieved accuracy is 20 mm with a ground resolution of 45 mm. As a test, the GoPro Hero 3+ camera was additionally mounted on a small, extendable pole. With this second low-cost, easy to apply monitoring approach, pictures were automatically taken every second in a stop-and-go mode. In order to capture the excavation pit (7 by 4 m), two different angles were used for holding the pole, which focused on the middle and on the border of the pit. This procedure was repeated on the following day in order to document the excavation process. For the registration of the images, the already existing and measured excavation nails were used, which are equally distributed over the whole site in a 1 m grid. Thus, a high accurate registration of the images was possible (>10 mm). In order to approve the accuracy of the already derived data, the whole site was also observed by a Faro Focus 3D LS 120 laser scanner. The measurements of this device were registered by spherical targets, which were measured in the same reference system. The accuracy of the registration and the ground resolution for the image based approach for both days was about 4 mm. From these two measurements the process of the excavation was easily

29 CFR 1926.651 - Specific excavation requirements.

Science.gov (United States)

2010-07-01

...) Exposure to vehicular traffic. Employees exposed to public vehicular traffic shall be provided with, and... containing a concentration of a flammable gas in excess of 20 percent of the lower flammable limit of the gas... ensure proper operation. (3) If excavation work interrupts the natural drainage of surface water (such as...

Support system, excavation arrangement, and process of supporting an object

Science.gov (United States)

Arnold, Bill W.

2017-08-01

A support system, an excavation arrangement, and a process of supporting an object are disclosed. The support system includes a weight-bearing device and a camming mechanism positioned below the weight-bearing device. A downward force on the weight-bearing device at least partially secures the camming mechanism to opposing surfaces. The excavation arrangement includes a borehole, a support system positioned within and secured to the borehole, and an object positioned on and supported by the support system. The process includes positioning and securing the support system and positioning the object on the weight-bearing device.

Excavation induced damage evolution during a mine-by experiment in Opalinus Clay

International Nuclear Information System (INIS)

Vietor, T.; Armand, G.; Nyonoya, S.; Schuster, K.; Wieczorek, K.

2010-01-01

Document available in extended abstract form only. In Switzerland Opalinus Clay, a potential host rock formation for a nuclear waste repository, is intensively studied in the Mont Terri Underground Rock Laboratory (URL) in North-Western Switzerland. During the 2008 extension of the URL, the construction works were repeatedly interrupted to implement monitoring systems for a mine-by experiment. The future position of a 24 m long tunnel was instrumented with 36 different monitoring systems comprising approximately 200 sensors. Key features of this tunnel were chosen similar to the current Swiss concept for emplacement tunnels for High Level Radioactive Waste: circular section, full-face excavation following the geological bedding, support by a thin layer of shotcrete and 6 anchors every 1.3 m. For a mine-by experiment 26 boreholes were equipped with 7 multipoint extensometers, two multi segment inclinometer chains and 26 pore pressure chambers. The data acquisition system recorded 12 data sets per hour. For seismic transmission and acoustic emission monitoring, 8 piezo-electric emitters and 15 piezo-electric receivers were installed in 5 boreholes. The excavation of the instrumented tunnel took place in October/November 2008. The activities on the site were monitored with a web cam to separate spontaneous and excavation induced rock mass reactions. Daily mappings of the tunnel face and the sidewalls revealed the fracture pattern that was generated ahead of the advancing excavation. Three sets of excavation activated discontinuities could be clearly identified. These three sets develop within the framework of the pre-existing tectonic micro-faults that generally have a half-meter spacing. Where their density is high the intensity of excavation induced new slip planes apparently drops. Despite the presence of micro-faults the deformation monitoring around the advancing tunnel face showed a remarkably homogenous response to the excavation. Inclinometer chain segments

Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

International Nuclear Information System (INIS)

Thoeny, R.

2014-01-01

Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

Energy Technology Data Exchange (ETDEWEB)

Thoeny, R.

2014-07-01

Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

Further excavations of the submerged city of Dwarka

Digital Repository Service at National Institute of Oceanography (India)

Rao, S.R.

Since 1983 the Marine Archaeology Unit of the National Institute of Oceanography is engaged in the offshore exploration and excavation of the legendary city of Dwaraka in the coastal waters of Dwarka in Gujarat. Brief accounts of the findings...

Biofuel or excavation? - Life cycle assessment (LCA) of soil remediation options

Energy Technology Data Exchange (ETDEWEB)

Suer, Pascal; Andersson-Skoeld, Yvonne [Swedish Geotechnical Institute, 58193 Linkoeping (Sweden)

2011-02-15

The environmental consequences of soil remediation through biofuel or through dig-and-dump were compared using life cycle assessment (LCA). Willow (Salix viminalis) was actually grown in-situ on a discontinued oil depot, as a phytoremediation treatment. These data were used for the biofuel remediation, while excavation-and-refill data were estimated from experience. The biofuel remediation had great environmental advantages compared to the ex situ excavation remediation. With the ReCiPe impact assessment method, which included biodiversity, the net environmental effect was even positive, in spite of the fact that the wood harvest was not utilised for biofuel production, but left on the contaminated site. Impact from the Salix viminalis cultivation was mainly through land use for the short rotation coppice, and through journeys of control personnel. The latter may be reduced when familiarity with biofuel as a soil treatment method increases. The excavation-and-refill remediation was dominated by the landfill and the transport of contaminated soil and backfill. (author)

Numerical Evaluation on Dynamic Response of Existing Underlying Tunnel Induced by Blasting Excavation of a Subway Tunnel

Directory of Open Access Journals (Sweden)

Jixue Zhou

2017-01-01

Full Text Available In Southwest China, most regions are mountainous, where traditional drill-and-blast method is adopted to excavate relatively harder rocks. However, blasting would cause vibration to adjacent structures and might result in damage or even failure. This paper considers a case where subway tunnel is overlying an existing railway tunnel, while the excavation requires blasting method. Vibration and stress distribution are calculated via Dynamic Finite Element Method (DFEM for both full-face excavation and CD method. Result shows that vibration induced by CD method is only 28% of that caused by full-face blasting with same distance. Peak vibration is located on the lining facing the blasting source, while peak tensile stress is on the other side of the contour due to the reflection of stress wave on strata boundary. And peak value of tensile stress induced by full-face blasting is capable of causing lining failure; thus full-face blasting is not suggested within 40 m beyond the underlying tunnel axis. However, CD method has shown much advantage, since blasting within 25 m is also considered safe to the underlying tunnel. But when the blasting source is as near as 12 m within the underlying tunnel, the CD method is no longer safe.

Lectures on Topics in Spatial Stochastic Processes

CERN Document Server

Capasso, Vincenzo; Ivanoff, B Gail; Dozzi, Marco; Dalang, Robert C; Mountford, Thomas S

2003-01-01

The theory of stochastic processes indexed by a partially ordered set has been the subject of much research over the past twenty years. The objective of this CIME International Summer School was to bring to a large audience of young probabilists the general theory of spatial processes, including the theory of set-indexed martingales and to present the different branches of applications of this theory, including stochastic geometry, spatial statistics, empirical processes, spatial estimators and survival analysis. This theory has a broad variety of applications in environmental sciences, social sciences, structure of material and image analysis. In this volume, the reader will find different approaches which foster the development of tools to modelling the spatial aspects of stochastic problems.

The multivariate supOU stochastic volatility model

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole; Stelzer, Robert

Using positive semidefinite supOU (superposition of Ornstein-Uhlenbeck type) processes to describe the volatility, we introduce a multivariate stochastic volatility model for financial data which is capable of modelling long range dependence effects. The finiteness of moments and the second order...... structure of the volatility, the log returns, as well as their "squares" are discussed in detail. Moreover, we give several examples in which long memory effects occur and study how the model as well as the simple Ornstein-Uhlenbeck type stochastic volatility model behave under linear transformations....... In particular, the models are shown to be preserved under invertible linear transformations. Finally, we discuss how (sup)OU stochastic volatility models can be combined with a factor modelling approach....

Stochastic variables in N=1 supersymmetric Yang-Mills theory

International Nuclear Information System (INIS)

Lechtenfeld, O.

1984-06-01

The stochastic structure of N=1 supersymmetric Yang-Mills theory is rederived by using a previously developed method for the construction of the (nonlocal) Nicolai map. The stochastic variables correspond to the fixed points of this mapping. The relations are derived in a light cone gauge and in general covariant gauges. (orig.)

Adaptive stochastic Galerkin FEM with hierarchical tensor representations

KAUST Repository

Eigel, Martin

2016-01-08

PDE with stochastic data usually lead to very high-dimensional algebraic problems which easily become unfeasible for numerical computations because of the dense coupling structure of the discretised stochastic operator. Recently, an adaptive stochastic Galerkin FEM based on a residual a posteriori error estimator was presented and the convergence of the adaptive algorithm was shown. While this approach leads to a drastic reduction of the complexity of the problem due to the iterative discovery of the sparsity of the solution, the problem size and structure is still rather limited. To allow for larger and more general problems, we exploit the tensor structure of the parametric problem by representing operator and solution iterates in the tensor train (TT) format. The (successive) compression carried out with these representations can be seen as a generalisation of some other model reduction techniques, e.g. the reduced basis method. We show that this approach facilitates the efficient computation of different error indicators related to the computational mesh, the active polynomial chaos index set, and the TT rank. In particular, the curse of dimension is avoided.

In Appreciation of Claude Warren and Susan Rose's "William Pengelly's Techniques of Archaeological Excavation"

Directory of Open Access Journals (Sweden)

David L. Browman

1997-11-01

Full Text Available The short (40 pages pamphlet by Warren and Rose (1994 provides the answer to a complex question regarding credit for an important archaeological methodology, stratigraphic excavation. Let me set the stage for this appreciation. Continuing research on the beginnings of stratigraphic excavations in North America (Browman and Givens 1996, I sought the origins of the idea of actually excavating by strata, rather than post-facto interpretation, seen in North American as early as 1895 in the work of Henry Chapman Mercer, but not really introduced into the repertoire of American techniques until the work of Gamio, Kidder and Nelson between 1911 and 1914. The roots of the latter three seemed to lie with individuals such as Reisner, Boas, Uhle, who in turn seemed to rely on Hugo Obennaier, Gabriel de Mortillet, Marcellin Boule, and perhaps Pitt-Rivers, while Mercer's work could be traced to Boule and Albert Gaudry. Doggedly following back the roots, I found that Chapman (1989 could make a reasonable case that Pitt-Rivers had actually learned of the idea of strati­graphic excavation from Evans, Prestwich, and Lubbock, from the British scientists working with the Upper and Middle Paleolithic excavations during 1858-1868.

Stochastic resonance: noise-enhanced order

International Nuclear Information System (INIS)

Anishchenko, Vadim S; Neiman, Arkady B; Moss, F; Shimansky-Geier, L

1999-01-01

Stochastic resonance (SR) provides a glaring example of a noise-induced transition in a nonlinear system driven by an information signal and noise simultaneously. In the regime of SR some characteristics of the information signal (amplification factor, signal-to-noise ratio, the degrees of coherence and of order, etc.) at the output of the system are significantly improved at a certain optimal noise level. SR is realized only in nonlinear systems for which a noise-intensity-controlled characteristic time becomes available. In the present review the physical mechanism and methods of theoretical description of SR are briefly discussed. SR features determined by the structure of the information signal, noise statistics and properties of particular systems with SR are studied. A nontrivial phenomenon of stochastic synchronization defined as locking of the instantaneous phase and switching frequency of a bistable system by external periodic force is analyzed in detail. Stochastic synchronization is explored in single and coupled bistable oscillators, including ensembles. The effects of SR and stochastic synchronization of ensembles of stochastic resonators are studied both with and without coupling between the elements. SR is considered in dynamical and nondynamical (threshold) systems. The SR effect is analyzed from the viewpoint of information and entropy characteristics of the signal, which determine the degree of order or self-organization in the system. Applications of the SR concept to explaining the results of a series of biological experiments are discussed. (reviews of topical problems)

Stochastic resonance: noise-enhanced order

Energy Technology Data Exchange (ETDEWEB)

Anishchenko, Vadim S; Neiman, Arkady B [N.G. Chernyshevskii Saratov State University, Saratov (Russian Federation); Moss, F [Department of Physics and Astronomy, University of Missouri at St. Louis (United States); Shimansky-Geier, L [Humboldt University at Berlin (Germany)

1999-01-31

Stochastic resonance (SR) provides a glaring example of a noise-induced transition in a nonlinear system driven by an information signal and noise simultaneously. In the regime of SR some characteristics of the information signal (amplification factor, signal-to-noise ratio, the degrees of coherence and of order, etc.) at the output of the system are significantly improved at a certain optimal noise level. SR is realized only in nonlinear systems for which a noise-intensity-controlled characteristic time becomes available. In the present review the physical mechanism and methods of theoretical description of SR are briefly discussed. SR features determined by the structure of the information signal, noise statistics and properties of particular systems with SR are studied. A nontrivial phenomenon of stochastic synchronization defined as locking of the instantaneous phase and switching frequency of a bistable system by external periodic force is analyzed in detail. Stochastic synchronization is explored in single and coupled bistable oscillators, including ensembles. The effects of SR and stochastic synchronization of ensembles of stochastic resonators are studied both with and without coupling between the elements. SR is considered in dynamical and nondynamical (threshold) systems. The SR effect is analyzed from the viewpoint of information and entropy characteristics of the signal, which determine the degree of order or self-organization in the system. Applications of the SR concept to explaining the results of a series of biological experiments are discussed. (reviews of topical problems)

Three-Dimensional Laser Scanning for Geometry Documentation and Construction Management of Highway Tunnels during Excavation

Science.gov (United States)

Gikas, Vassilis

2012-01-01

Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operations have a great impact on both technical and economic aspects of a project. This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels. It provides a detailed overview of the static laser scanning method, its principles of operation and applications for tunnel construction operations. Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction. Specific case studies are considered based on two construction sites in Greece. Particularly, the potential of the method is examined for checking the tunnel profile, producing volume computations and validating the smoothness/thickness of shotcrete layers at an excavation stage and during the completion of excavation support and primary lining. An additional example of the use of the method in the geometric documentation of the concrete lining formwork is examined and comparisons against dimensional tolerances are examined. Experimental comparisons and analyses of the laser scanning method against conventional surveying techniques are also considered. PMID:23112655

Physico-chemical properties of excavated plastic from landfill mining and current recycling routes.

Science.gov (United States)

Canopoli, L; Fidalgo, B; Coulon, F; Wagland, S T

2018-06-01

In Europe over 5.25 billion tonnes of waste has been landfilled between 1995 and 2015. Among this large amount of waste, plastic represents typically 5-25 wt% which is significant and has the potential to be recycled and reintroduced into the circular economy. To date there is still however little information available of the opportunities and challenges in recovering plastics from landfill sites. In this review, the impacts of landfill chemistry on the degradation and/or contamination of excavated plastic waste are analysed. The feasibility of using excavated plastic waste as feedstock for upcycling to valuable chemicals or liquid fuels through thermochemical conversion is also critically discussed. The limited degradation that is experienced by many plastics in landfills (>20 years) which guarantee that large amount is still available is largely due to thermooxidative degradation and the anaerobic conditions. However, excavated plastic waste cannot be conventionally recycled due to high level of ash, impurities and heavy metals. Recent studies demonstrated that pyrolysis offers a cost effective alternative option to conventional recycling. The produced pyrolysis oil is expected to have similar characteristics to petroleum diesel oil. The production of valuable product from excavated plastic waste will also increase the feasibility of enhanced landfill mining projects. However, further studies are needed to investigate the uncertainties about the contamination level and degradation of excavated plastic waste and address their viability for being processed through pyrolysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Neuro-Inspired Computing with Stochastic Electronics

KAUST Repository

Naous, Rawan

2016-01-06

The extensive scaling and integration within electronic systems have set the standards for what is addressed to as stochastic electronics. The individual components are increasingly diverting away from their reliable behavior and producing un-deterministic outputs. This stochastic operation highly mimics the biological medium within the brain. Hence, building on the inherent variability, particularly within novel non-volatile memory technologies, paves the way for unconventional neuromorphic designs. Neuro-inspired networks with brain-like structures of neurons and synapses allow for computations and levels of learning for diverse recognition tasks and applications.

Impact-Actuated Digging Tool for Lunar Excavation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Honeybee Robotics proposes to develop a vacuum compatible, impact-actuated digging tool for the excavation of frozen and compacted regolith on the lunar surface and...

A new bee species that excavates sandstone nests

Science.gov (United States)

Many wonder why animals act in seemingly injurious ways. Understanding the behavior of pollinators such as bees is especially important because of the necessary ecosystem service they provide. The new species Anthophora pueblo, discovered excavating sandstone nests, provides a model system for addre...

Stability of underground excavations in a repository system

International Nuclear Information System (INIS)

Calash, A.Y.; Greer, J.C.; Andrea, S.J.; Chowdhury, A.H.; Nguyen, V.V.

1988-01-01

The DOE is investigating the feasibility of constructing a deep geologic repository at the Hanford Site, Washington, for the permanent disposal of nuclear waste. The underground openings associated with the repository design include shafts, tunnels, emplacement rooms and boreholes. The stability of these underground openings, the extent and characteristics of the disturbed zones due to excavation, and their effects on groundwater flow path and travel time have a primary influence on the performance assessment of the Hanford Site as a nuclear waste repository. This study is being done in accordance with the requirements of the NRC. Results of structural analyses of shafts and tunnels under in situ stresses and/or medium weight are presented in this paper. Four different analyses were carried out to analyze the shaft: a plane strain model, axisymmetric model, 3-D model of a single material medium, and 3-D model of a three material medium

Air Quality and Microclimatic Parameters During Excavation of Mala Kapela Tunnel

Directory of Open Access Journals (Sweden)

Mario Klanfar

2015-06-01

Full Text Available During excavation of the Mala Kapela tunnel, measurements of harmful gases concentration, ventilation parameters and microclimatic parameters were performed. Measurements were done in 17 occasions during period of 16 months, along the advance of the tunnel excavation. Consequently, large amount of data was obtained, in different tunnel chainages, ventilation ducts length, and in different work operations during the excavation. Main sources of harmful gases during tunnel excavation are explosives and diesel equipment. The concentration of the same mainly depends on explosive charge and overall diesel equipment power, present at the excavation face of the tunnel. Continuous measurements of the concentration of carbon monoxide (CO and dioxide (CO2, and nitrogen oxide (NO and dioxide (NO2 was performed during drilling, blasting, and loading and haulage operations. Measurements were done in 45 cases in total. Recorded data was analysed, where peak concentrations were joined to corresponding operation and the tunnel chainage. Regulations on threshold limit values were used to determine if concentrations rise above the permissible ones. In case they do, the time required for dilution of gases below permissible concentration was noted. Typically, concentrations of all measured gases rise rapidly after blasting. Afterwards, ventilation system acts to dilute them and maintain them relatively constant until the end of loading and haulage. According to measurements in this research, highest concentrations and longest time of dilution were found after blasting. At the same time, concentration of all measured gases exceeds permissible values. Carbon monoxide is found to exceed permissible values during all work operations. It shows most frequent transgression above the limit (in 33 to 100% of cases and highest time of dilution (up to 40 min. Air supply to the excavation face was measured in 25 cases. It was correlated to the length of ventilation ducts, as

Remote Excavation System technology evaluation report: Buried Waste Robotics Program

International Nuclear Information System (INIS)

1993-09-01

This document describes the results from the Remote Excavation System demonstration and testing conducted at the Idaho National Engineering Laboratory during June and July 1993. The purpose of the demonstration was to ascertain the feasibility of the system for skimming soil and removing various types of buried waste in a safe manner and within all regulatory requirements, and to compare the performances of manual and remote operation of a backhoe. The procedures and goals of the demonstration were previously defined in The Remote Excavation System Test Plan, which served as a guideline for evaluating the various components of the system and discussed the procedures used to conduct the tests

Noncausal stochastic calculus

CERN Document Server

Ogawa, Shigeyoshi

2017-01-01

This book presents an elementary introduction to the theory of noncausal stochastic calculus that arises as a natural alternative to the standard theory of stochastic calculus founded in 1944 by Professor Kiyoshi Itô. As is generally known, Itô Calculus is essentially based on the "hypothesis of causality", asking random functions to be adapted to a natural filtration generated by Brownian motion or more generally by square integrable martingale. The intention in this book is to establish a stochastic calculus that is free from this "hypothesis of causality". To be more precise, a noncausal theory of stochastic calculus is developed in this book, based on the noncausal integral introduced by the author in 1979. After studying basic properties of the noncausal stochastic integral, various concrete problems of noncausal nature are considered, mostly concerning stochastic functional equations such as SDE, SIE, SPDE, and others, to show not only the necessity of such theory of noncausal stochastic calculus but ...

A method of modeling time-dependent rock damage surrounding underground excavations in multiphase groundwater flow

International Nuclear Information System (INIS)

Christian-Frear, T.; Freeze, G.

1997-01-01

Underground excavations produce damaged zones surrounding the excavations which have disturbed hydrologic and geomechanical properties. Prediction of fluid flow in these zones must consider both the mechanical and fluid flow processes. Presented here is a methodology which utilizes a mechanical model to predict damage and disturbed rock zone (DRZ) development around the excavation and then uses the predictions to develop time-dependent DRZ porosity relationships. These relationships are then used to adjust the porosity of the DRZ in the fluid flow model based upon the time and distance from the edge of the excavation. The application of this methodology is presented using a site-specific example from the Waste Isolation Pilot Plant, a US Department of Energy facility in bedded salts being evaluated for demonstration of the safe underground disposal of transuranic waste from US defense-related activities

Detecting defects in diaphragm walls prior to excavation

NARCIS (Netherlands)

Spruit, R.; Hopman, V.; Van Tol, A.F.; Broere, W.

2011-01-01

Recent incidents with leaking diaphragm walls during construction of subway lines in Amsterdam and Rotterdam (Netherlands) have led to reconsideration of the diaphragm wall as a retaining wall construction for deep excavations. In our opinion the joints between the panels are the weak spot. During

Novel, low-vibration excavation techniques for underground radioactive waste storage

International Nuclear Information System (INIS)

Kogelmann, W.J.

1994-01-01

In order to meet the construction specifications of the challenging Yucca Mountain nuclear waste repository, novel, low-vibration tunneling and shaft sinking techniques must be applied. Conventional roadheaders, even with reduced cutting speed, cannot be employed due to the high strength and widely varying physical properties of the rock formations. The Multi Tool Miner (MTM) concept utilizes both an impact hammer, for efficient hard rock mining, and a cutter head, tooled with drag-bits (picks), to profile tunnel walls down to the sound, undisturbed rock, in order to meet the 10,000-year stability requirement for underground structures. As the operational requirements and rock conditions at the Yucca Mountain site are not suitable for wide, transverse open-quotes ripperclose quotes cutting drums, a small diameter, in-line, open-quotes milling augerclose quotes cutter head was developed. The synergetic combination of high-production hammer excavation and precise milling will facilitate the construction of stable, long-life underground structures within the budget limitations mandated by Congress

Application of Stochastic Sensitivity Analysis to Integrated Force Method

Directory of Open Access Journals (Sweden)

X. F. Wei

2012-01-01

Full Text Available As a new formulation in structural analysis, Integrated Force Method has been successfully applied to many structures for civil, mechanical, and aerospace engineering due to the accurate estimate of forces in computation. Right now, it is being further extended to the probabilistic domain. For the assessment of uncertainty effect in system optimization and identification, the probabilistic sensitivity analysis of IFM was further investigated in this study. A set of stochastic sensitivity analysis formulation of Integrated Force Method was developed using the perturbation method. Numerical examples are presented to illustrate its application. Its efficiency and accuracy were also substantiated with direct Monte Carlo simulations and the reliability-based sensitivity method. The numerical algorithm was shown to be readily adaptable to the existing program since the models of stochastic finite element and stochastic design sensitivity are almost identical.

A study on excavation of rock mass by lasers. Researching the possibility of utilizing low-power lasers

Energy Technology Data Exchange (ETDEWEB)

Ito, Fumio [Taisei Corporation, Technology Research Center, Yokohama, Kanagawa (Japan)

2000-03-01

The object of this research is to develop the techniques of rock-mass excavation by laser irradiation. This rock-mass excavation technique by lasers has a characteristic of extremely little effect to the surroundings of an excavation site no matter how the target rock mass is with regard to geological aspects and given physical property. Moreover, it could be utilized in excavation of waste dump facilities, which need to be re-buried, and applied to excavation of long piles and tunnels, which are drilled through different kinds of strata, and to improvement of rock mass and ground. Lasers have a characteristic of concentrating the energy into a limited point and not only discontinue or cut a large area with a small output like sharp scissors but also block up the cracks deep inside the rock mass by fusing vitrification for its improvement. It leads to restrain the loss of energy, minimization of the effected environment, effective utilization of resources and energy, environmental restoration, and improvement of the working environment. In the field of nuclear fuel, which includes excavating dump pits, dismantling a furnace, and taking appropriate steps of mine remains, excavating, cutting, and fusing could be required to do within a limited space of rock mass or concrete. Up to the present, those things have been done mainly by large machines, but it is too scarce in possibility for them to improve their large size, heavy weight, difficulty in unmanned operation, limited shapes of cutting, and stabilization of waste. In this research the concrete system images have been examined, doing the fundamental researches about higher-power lasers, smaller sizing, transmitting by fibers to find our the breakthrough to realization of laser excavation, This year, as the summary of examining the laser excavation techniques, utilizing a low-power laser, which is thought to be highly effective in rock-mass improvement, will be examined, considering application of the technique

3D Numerical Modeling of Pile Group Responses to Excavation-Induced Stress Release in Silty Clay

Directory of Open Access Journals (Sweden)

M. A. Soomro

2018-02-01

Full Text Available Development of underground transportation systems consists of tunnels, basement construction excavations and cut and cover tunnels which may encounter existing pile groups during their construction. Since many previous studies mainly focus on the effects of excavations on single piles, settlement and load transfer mechanism of a pile group subjected to excavation-induced stress release are not well investigated and understood. To address these two issues, three-dimensional coupled-consolidation numerical analysis is conducted by using a hypoplastic model which takes small-strain stiffness into account. A non-linear pile group settlement was induced. This may be attributed to reduction of shaft resistance due to excavation induced stress release, the pile had to settle substantially to further mobilise end-bearing. Compared to the Sp of the pile group, induced settlement of the single pile is larger with similar settlement characteristics. Due to the additional settlement of the pile group, factor of safety for the pile group can be regarded as decreasing from 3.0 to 1.4, based on a displacement-based failure load criterion. Owing to non-uniform stress release, pile group tilted towards the excavation with value of 0.14%. Due to excavation-induced stress release and dragload, head load of rear piles was reduced and transferred to rear piles. This load transfer can increase the axial force in front piles by 94%.

Computational Methods in Stochastic Dynamics Volume 2

CERN Document Server

Stefanou, George; Papadopoulos, Vissarion

2013-01-01

The considerable influence of inherent uncertainties on structural behavior has led the engineering community to recognize the importance of a stochastic approach to structural problems. Issues related to uncertainty quantification and its influence on the reliability of the computational models are continuously gaining in significance. In particular, the problems of dynamic response analysis and reliability assessment of structures with uncertain system and excitation parameters have been the subject of continuous research over the last two decades as a result of the increasing availability of powerful computing resources and technology.   This book is a follow up of a previous book with the same subject (ISBN 978-90-481-9986-0) and focuses on advanced computational methods and software tools which can highly assist in tackling complex problems in stochastic dynamic/seismic analysis and design of structures. The selected chapters are authored by some of the most active scholars in their respective areas and...

Structural Stability Monitoring of a Physical Model Test on an Underground Cavern Group during Deep Excavations Using FBG Sensors

Directory of Open Access Journals (Sweden)

Yong Li

2015-08-01

Full Text Available Fiber Bragg Grating (FBG sensors are comprehensively recognized as a structural stability monitoring device for all kinds of geo-materials by either embedding into or bonding onto the structural entities. The physical model in geotechnical engineering, which could accurately simulate the construction processes and the effects on the stability of underground caverns on the basis of satisfying the similarity principles, is an actual physical entity. Using a physical model test of underground caverns in Shuangjiangkou Hydropower Station, FBG sensors were used to determine how to model the small displacements of some key monitoring points in the large-scale physical model during excavation. In the process of building the test specimen, it is most successful to embed FBG sensors in the physical model through making an opening and adding some quick-set silicon. The experimental results show that the FBG sensor has higher measuring accuracy than other conventional sensors like electrical resistance strain gages and extensometers. The experimental results are also in good agreement with the numerical simulation results. In conclusion, FBG sensors could effectively measure small displacements of monitoring points in the whole process of the physical model test. The experimental results reveal the deformation and failure characteristics of the surrounding rock mass and make some guidance for the in situ engineering construction.

Scalable inference for stochastic block models

KAUST Repository

Peng, Chengbin; Zhang, Zhihua; Wong, Ka-Chun; Zhang, Xiangliang; Keyes, David E.

2017-01-01

Community detection in graphs is widely used in social and biological networks, and the stochastic block model is a powerful probabilistic tool for describing graphs with community structures. However, in the era of "big data," traditional inference

Apparatus and method of measuring fluctuations of excavated mud amount in a slurry line

International Nuclear Information System (INIS)

Yamazaki, H.; Kubota, R.; Uchida, Y.; Kasuya, T.; Seki, N.

1976-01-01

An apparatus and method for measuring fluctuations in amount of soil in slurry or soil-containing fluid line is described. Each system of feeding the slurry typically to tunneling face and draining it therefrom in the slurry line is provided with gamma-ray densimeter and electromagnetic flow-meter to obtain respective amounts of soil only (dry-soil amounts) in the slurry flowing through each of said systems from respective outputs of these meters in each system, so that actually excavated amount through ground layer of a shielded excavator at the tunneling face can be measured by the difference between the respective dry-soil amounts. The excavator will be advanced depending on this measured amount

Excavation damage and disturbance in crystalline rock - results from experiments and analyses

International Nuclear Information System (INIS)

Baeckblom, Goeran

2008-11-01

SKB plans to submit the application to site and construct the final repository for spent nuclear fuel in 2010. One important basis for the application is the results of the safety assessments, for which one particular dataset is the axial hydraulic properties along the underground openings used to calculate the transport resistance for radionuclide transport in the event that the canister is impaired. SKB initiated a project (Zuse) to be run over the period 2007-2009 to: - establish the current knowledge base on excavation damage and disturbance with particular focus on the axial hydraulic properties along the underground openings; - provide a basis for the requirements and compliance criteria for the excavation damaged and disturbed zone; - devise methods and instruments to infer or measure the excavation damage and disturbance at different times during the repository construction and operation before closure; - propose demonstration tests for which the methods are used in situ to qualify appropriate data for use in the safety reports. This report presents the results of the first stage of the Zuse project. Previous major experiments and studies in Canada, Finland, Japan, Sweden and Switzerland on spalling, excavation damage and disturbance was compiled and evaluated to provide the SR-Site report with a defendable database on the properties for the excavation damage and disturbance. In preparation for the SR-Site report, a number of sensitivity studies were conducted in which reasonable ranges of values for spalling and damage were selected in combination with an impaired backfill. The report here describes the construction of the repository in eleven steps and for each of these steps, the potential evolution of THMCB (Thermal, Mechanical, Hydraulic and Chemical/ Biological) processes are reviewed. In this work it was found that descriptions of the chemical and microbiological evolution connected with excavation damage and disturbance was lacking. The preliminary

National Advanced Drilling and Excavation Technologies Institute. Status report, March 1997

Energy Technology Data Exchange (ETDEWEB)

Peterson, C.

1997-12-31

The National Advanced Drilling and Excavation Technologies (NADET) program is intended to pool support, talent, and technologies of the industries dependent upon drilling and excavation technologies to initiate, coordinate, and sustain programs capable of developing substantial technological advances. The NADET Institute has been funded by the DOE Office of Geothermal Technologies and is now supporting seven projects aimed at advanced geothermal drilling technologies. The Institute seeks to broaden its base of funding and technological support from both government and industry sources. Encouraging progress has been made with the support of dues-paying industrial members and industrial sponsorship of a substantial drilling research study.

Long-range terrain characterization for productive regolith excavation, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed research will develop long-range terrain characterization technologies for autonomous excavation in planetary environments. This work will develop a...

Physical soil properties and slope treatments effects on hydraulic excavator productivity for forest road construction.

Science.gov (United States)

Parsakho, Aidin; Hosseini, Seyed Ataollah; Jalilvand, Hamid; Lotfalian, Majid

2008-06-01

Effects of moisture, porosity and soil bulk density properties, grubbing time and terrain side slopes on pc 220 komatsu hydraulic excavator productivity were investigated in Miana forests road construction project which located in the northern forest of Iran. Soil moisture and porosity determined by samples were taken from undisturbed soil. The elements of daily works were measured with a digital stop watch and video camera in 14 observations (days). The road length and cross section profiles after each 20 m were selected to estimate earthworks volume. Results showed that the mean production rates for the pc 220 komatsu excavators were 60.13 m3 h(-1) and earthwork 14.76 m h(-1) when the mean depth of excavation or cutting was 4.27 m3 m(-1), respectively. There was no significant effects (p = 0.5288) from the slope classes' treatments on productivity, whereas grubbing time, soil moisture, bulk density and porosity had significantly affected on excavator earthworks volume (p < 0.0001). Clear difference was showed between the earthwork length by slope classes (p = 0.0060). Grubbing time (p = 0.2180), soil moisture (p = 0.1622), bulk density (p = 0.2490) and porosity (p = 0.2159) had no significant effect on the excavator earthworks length.

Shaft Excavation in Frozen Ground at Point 5

CERN Document Server

Osborne, J

2000-01-01

Construction work on the 112 MCHF civil engineering contract started at Point 5 in August 1998. The new surface buildings and underground structures are necessary to accommodate the CMS detector for the LHC Project. The principal underground works consist of two new shafts, two parallel caverns separated by a supporting pillar, and a number of small connection tunnels and service galleries. The two shafts are to be sunk through approximately 50 m of water-bearing moraine to the underlying molasse rock. From a number of possible construction methods, ground freezing of the moraine was considered to be most appropriate. The ground freezing is used to control the groundwater and to support temporarily the moraine during excavation and lining of the shafts. The aim of this paper is to present the ground-freezing technique and to discuss the advantages and disadvantages of the system in the light of its first few months of running on the Point 5 site.

Impact of Drill and Blast Excavation on Repository Performance Confirmation

International Nuclear Information System (INIS)

Keller, R.; Francis, N.; Houseworth, J.; Kramer, N.

2000-01-01

There has been considerable work accomplished internationally examining the effects of drill and blast excavation on rock masses surrounding emplacement openings of proposed nuclear waste repositories. However, there has been limited discussion tying the previous work to performance confirmation models such as those proposed for Yucca Mountain, Nevada. This paper addresses a possible approach to joining the available information on drill and blast excavation and performance confirmation. The method for coupling rock damage data from drill and blast models to performance assessment models for fracture flow requires a correlation representing the functional relationship between the peak particle velocity (PPV) vibration levels and the potential properties that govern water flow rates in the host rock. Fracture aperture and frequency are the rock properties which may be most influenced by drill and blast induced vibration. If it can be shown (using an appropriate blasting model simulation) that the effect of blasting is far removed from the waste package in an emplacement drift, then disturbance to the host rock induced in the process of drill and blast excavation may be reasonably ignored in performance assessment calculations. This paper proposes that the CANMET (Canada Center for Mineral and Energy Technology) Criterion, based on properties that determine rock strength, may be used to define a minimum PPV. This PPV can be used to delineate the extent of blast induced damage. Initial applications have demonstrated that blasting models can successfully be coupled with this criterion to predict blast damage surrounding underground openings. The Exploratory Studies Facility at Yucca Mountain has used a blasting model to generate meaningful estimates of near-field vibration levels and damage envelopes correlating to data collected from pre-existing studies conducted. Further work is underway to expand this application over a statistical distribution of geologic

Excavation damage and disturbance in crystalline rock - results from experiments and analyses

Energy Technology Data Exchange (ETDEWEB)

Baeckblom, Goeran (Conrox AB, Stockholm (Sweden))

2008-11-15

SKB plans to submit the application to site and construct the final repository for spent nuclear fuel in 2010. One important basis for the application is the results of the safety assessments, for which one particular dataset is the axial hydraulic properties along the underground openings used to calculate the transport resistance for radionuclide transport in the event that the canister is impaired. SKB initiated a project (Zuse) to be run over the period 2007-2009 to: - establish the current knowledge base on excavation damage and disturbance with particular focus on the axial hydraulic properties along the underground openings; - provide a basis for the requirements and compliance criteria for the excavation damaged and disturbed zone; - devise methods and instruments to infer or measure the excavation damage and disturbance at different times during the repository construction and operation before closure; - propose demonstration tests for which the methods are used in situ to qualify appropriate data for use in the safety reports. This report presents the results of the first stage of the Zuse project. Previous major experiments and studies in Canada, Finland, Japan, Sweden and Switzerland on spalling, excavation damage and disturbance was compiled and evaluated to provide the SR-Site report with a defendable database on the properties for the excavation damage and disturbance. In preparation for the SR-Site report, a number of sensitivity studies were conducted in which reasonable ranges of values for spalling and damage were selected in combination with an impaired backfill. The report here describes the construction of the repository in eleven steps and for each of these steps, the potential evolution of THMCB (Thermal, Mechanical, Hydraulic and Chemical/ Biological) processes are reviewed. In this work it was found that descriptions of the chemical and microbiological evolution connected with excavation damage and disturbance was lacking. The preliminary

Analysis of long-term closure in drifts excavated in Callovo-Oxfordian clay-stone: roles of anisotropy and hydro-mechanical couplings

International Nuclear Information System (INIS)

Guayacan Carrillo, Lina Maria

2016-01-01

The French National Radioactive Waste Management Agency (Andra) began in 2000 the construction of an Underground Research Laboratory (URL) with the main goal of demonstrating the feasibility of a geological repository in Callovo-Oxfordian clay-stone. Several research programs have taken place to improve the knowledge of the rock properties and its response to the excavation progress. A network of experimental drifts has been constructed with variations on: excavation method, structure geometry, supports system and orientations with respect to principal stresses' directions. In each drift different sections have been instrumented to monitor the hydro-mechanical behavior of the rock mass formation. Continuous monitoring of the excavated zone around the drifts in the main level (-490 m) revealed the development of a fractured zone (extensional and shear fractures) induced by the excavation. The extent of this fractured zone depends on the drift orientation regarding the in-situ stress field. Accordingly, the convergence measurements showed an anisotropic closure which depends also on the drifts' orientations. Moreover, marked overpressures and an anisotropic pore pressure field around the drifts have been also observed. The approach proposed in this work is mainly based on a direct analysis of the convergence measurements, for studying the anisotropic response of the rock formation during and after excavation. The convergence evolution is analyzed on the basis of the semi-empirical law proposed by Sulem et al. (1987) [Int J Rock Mech Min Sci Geomech Abstr 24: 145-154]. The monitoring and analysis of convergence data can provide a reliable approach of the interaction between rock mass and support. Therefore, the anisotropy and the variability of the closure are analyzed taking into account different field cases: drifts excavated in two different orientations (i.e. influence of the initial stress state), different methods, sizes and rates of excavation and

STOCHASTIC FLOWS OF MAPPINGS

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

In this paper, the stochastic flow of mappings generated by a Feller convolution semigroup on a compact metric space is studied. This kind of flow is the generalization of superprocesses of stochastic flows and stochastic diffeomorphism induced by the strong solutions of stochastic differential equations.

Stochastic processes dominate during boreal bryophyte community assembly.

Science.gov (United States)

Fenton, Nicole J; Bergeron, Yves

2013-09-01

Why are plant species found in certain locations and not in others? The study of community assembly rules has attempted to answer this question, and many studies articulate the historic dichotomy of deterministic (predictable niches) vs. stochastic (random or semi-random processes). The study of successional sequences to determine whether they converge, as would be expected by deterministic theory, or diverge, as stochastic theory would suggest, has been one method used to investigate this question. In this article we ask the question: Do similar boreal bryophyte communities develop in the similar habitat created by convergent succession after fires of different severities? Or do the stochastic processes generated by fires of different severity lead to different communities? Specifically we predict that deterministic structure will be more important for large forest-floor species than stochastic processes, and that the inverse will be true for small bryophyte species. We used multivariate regression trees and model selection to determine the relative weight of structure (forest structure, substrates, soil structure) and processes (fire severity) for two groups of bryophyte species sampled in 12 sites (seven high-severity and five low-severity fires). Contrary to our first hypothesis, processes were as important for large forest-floor bryophytes as for small pocket species. Fire severity, its interaction with the quality of available habitat, and its impact on the creation of biological legacies played dominant roles in determining community structure. In this study, sites with nearly identical forest structure, generated via convergent succession after high- and low-severity fire, were compared to see whether these sites supported similar bryophyte communities. While similar to some degree, both the large forest-floor species and the pocket species differed after high-severity fire compared to low-severity fire. This result suggests that the "how," or process of

A research on the excavation, support, and environment control of large scale underground space

Energy Technology Data Exchange (ETDEWEB)

Kang, Pil Chong; Kwon, Kwang Soo; Jeong, So Keul [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1995-12-01

With the growing necessity of the underground space due to the deficiency of above-ground space, the size and shape of underground structures tend to be complex and diverse. This complexity and variety force the development of new techniques for rock mass classification, excavation and supporting of underground space, monitoring and control of underground environment. All these techniques should be applied together to make the underground space comfortable. To achieve this, efforts have been made on 5 different areas; research on the underground space design and stability analysis, research on the techniques for excavation of rock by controlled blasting, research on the development of monitoring system to forecast the rock behaviour of underground space, research on the environment inspection system in closed space, and research on dynamic analysis of the airflow and environmental control in the large geos-spaces. The 5 main achievements are improvement of the existing structure analysis program(EXCRACK) to consider the deformation and failure characteristics of rock joints, development of new blasting design (SK-cut), prediction of ground vibration through the newly proposed wave propagation equation, development and In-Situ application of rock mass deformation monitoring system and data acquisition software, and trial manufacture of the environment inspection system in closed space. Should these techniques be applied to the development of underground space, prevention of industrial disaster, cut down of construction cost, domestication of monitoring system, improvement of tunnel stability, curtailment of royalty, upgrade of domestic technologies will be brought forth. (Abstract Truncated)

Acoustic emission and ultrasonic-velocity methods used to characterise the excavation disturbance associated with deep tunnels in hard rock

Science.gov (United States)

Falls, Stephen D.; Young, R. Paul

1998-04-01

Acoustic emission (AE) and ultrasonic-velocity monitoring studies have been undertaken at both the Atomic Energy of Canada Limited (AECL) Underground Research Laboratory (URL) and at the Swedish Nuclear Fuel Waste Management Company (SKB) Hard Rock Laboratory (HRL). At both locations the excavations were tunnels in granitic material at approximately 420 m depth. However, the stress regime was more severe at the URL Mine-by tunnel site than the HRL ZEDEX tunnel. Different parts of the ZEDEX tunnel were created using different excavation techniques. Using AE and ultrasonic techniques to study these tunnels we have been able to examine the nature of the excavation-disturbed zone around the tunnel, as well as examining the effects of different stress regimes and excavation techniques. Studies were undertaken both during and after the Mine-by tunnel excavation and during excavation in the ZEDEX tunnel. AE monitoring in the wall of the Mine-by tunnel during excavation showed that some activity occurred in the sidewall regions, but the spatial density of AE hypocentres increased toward the regions in the floor and roof of the tunnel where breakout notches formed. This sidewall activity was clustered primarily within 0.5 m of the tunnel wall. AE monitoring in the floor of the tunnel showed that small numbers of AE continued to occur in the notch region in the floor of the tunnel over 2 years after excavation was completed. This activity became more acute as the rock was heated, imposing thermally induced stresses on the volume. Ultrasonic-velocity studies both in the floor and the wall of the tunnel showed that the velocity is strongly anisotropic with the direction of slowest velocity orthogonal to the tunnel surface. The velocity increased with distance into the rock from the tunnel surface. In the floor, this effect was seen up to 2 m from the tunnel surface. Most of the change occurred within the first 0.5 m from the tunnel perimeter. At the lower-stress HRL, most of

On justification of efficient Energy-Force parameters of Hydraulic-excavator main mechanisms

Science.gov (United States)

Komissarov, Anatoliy; Lagunova, Yuliya; Shestakov, Viktor; Lukashuk, Olga

2018-03-01

The article formulates requirements for energy-efficient designs of the operational equipment of a hydraulic excavator (its boom, stick and bucket) and defines, for a mechanism of that equipment, a new term “performance characteristic”. The drives of main rotation mechanisms of the equipment are realized by hydraulic actuators (hydraulic cylinders) and transmission (leverage) mechanisms, with the actuators (the cylinders themselves, their pistons and piston rods) also acting as links of the leverage. Those drives are characterized by the complexity of translating mechanical-energy parameters of the actuators into energy parameters of the driven links (a boom, a stick and a bucket). Relations between those parameters depend as much on the types of mechanical characteristics of the hydraulic actuators as on the types of structural schematics of the transmission mechanisms. To assess how energy-force parameters of the driven links change when a typical operation is performed, it was proposed to calculate performance characteristics of the main mechanisms as represented by a set of values of transfer functions, i.e. by functional dependences between driven links and driving links (actuators). Another term “ideal performance characteristic” of a mechanism was introduced. Based on operation-emulating models for the main mechanisms of hydraulic excavators, analytical expressions were derived to calculate kinematic and force transfer functions of the main mechanisms.

The SNL/NM Classified Waste Landfill Excavation: Lessons Learned Moving from Planning to Implementation

International Nuclear Information System (INIS)

Galloway, Robert B; Slavin, Paula

1999-01-01

The Sandia National Laboratories/New Mexico (SNL/NM) Environmental Restoration Project is halfway through excavating the Classified Waste Landfill in Technical Area II, a disposal area for weapon components for approximately 40 years. While the planning phase of any project is important, it is only a means of getting to the field implementation phase where reality quickly sinks in. Documents outlining the general processes are developed, heavy equipment, supply needs, requisite skills, and staffing levels are anticipated, and contingencies for waste management are put in place. However, the nature of landfill excavation dictates that even the most detailed plans will probably change. This project is proving that trying to account for undefined variables and predicting the total cost of landfill remediation is very difficult if the contents are not well known. In landfill excavation, contingency cannot be minimized. During development of the waste management plan, it was recognized that even the best forecasting could not formulate the perfect cradle-to-grave processes because waste streams are rarely definable before excavation begins. Typically, as excavation progresses and waste streams are generated, new characterization information allows further definition of disposal options which, in turn, modify the generation/management process. A general plan combined with close involvement of waste management personnel to resolve characterization and packaging questions during generation has worked very well. And, as expected, each new pit excavated creates new waste management challenges. The material excavated consists primarily of classified weapon assemblies and related components, so disposition must include demilitarization and sanitization. The demilitarization task at the start of the project was provided by an SNL/NM group that has since lost their funding and operational capability. This project is having to take on the task of disassembly, destruction, and

Stochastic processes

CERN Document Server

Parzen, Emanuel

1962-01-01

Well-written and accessible, this classic introduction to stochastic processes and related mathematics is appropriate for advanced undergraduate students of mathematics with a knowledge of calculus and continuous probability theory. The treatment offers examples of the wide variety of empirical phenomena for which stochastic processes provide mathematical models, and it develops the methods of probability model-building.Chapter 1 presents precise definitions of the notions of a random variable and a stochastic process and introduces the Wiener and Poisson processes. Subsequent chapters examine

In-plane current induced domain wall nucleation and its stochasticity in perpendicular magnetic anisotropy Hall cross structures

International Nuclear Information System (INIS)

Sethi, P.; Murapaka, C.; Lim, G. J.; Lew, W. S.

2015-01-01

Hall cross structures in magnetic nanowires are commonly used for electrical detection of magnetization reversal in which a domain wall (DW) is conventionally nucleated by a local Oersted field. In this letter, we demonstrate DW nucleation in Co/Ni perpendicular magnetic anisotropy nanowire at the magnetic Hall cross junction. The DWs are nucleated by applying an in-plane pulsed current through the nanowire without the need of a local Oersted field. The change in Hall resistance, detected using anomalous Hall effect, is governed by the magnetic volume switched at the Hall junction, which can be tuned by varying the magnitude of the applied current density and pulse width. The nucleated DWs are driven simultaneously under the spin transfer torque effect when the applied current density is above a threshold. The possibility of multiple DW generation and variation in magnetic volume switched makes nucleation process stochastic in nature. The in-plane current induced stochastic nature of DW generation may find applications in random number generation

Existence and density theorems for stochastic maps on commutative C*-algebras

International Nuclear Information System (INIS)

Alberti, P.M.; Uhlmann, A.

1979-06-01

Theorems are presented on the structure of stochastic and normalized positive linear maps over commutative C*-algebras. It is shown how strongly the solution of the n-tupel problem for stochastic maps relates to the fact that stochastic maps of finite rank are weakly dense within stochastic maps in case of a commutative C*-algebra. A new proof of the density theorem is given and (besides the solution of the n-tupel problem) results are derived concerning the extremal maps of certain convex subsets which are weakly dense. All stated facts suggest application in statistical physics (algebraic approach), especially concerning questions around evolution of classical systems. (author)

Excavation-drier method of energy-peat extraction reduces long-term climatic impact

Energy Technology Data Exchange (ETDEWEB)

Silvan, N.; Silvan, K.; Laine, J. [Finnish Forest Research Inst., Parkano (Finland)], e-mail: niko.silvan@metla.fi; Vaisanen, S.; Soukka, R. [Lappeenranta Univ.of Techology (Finland)

2012-11-01

Climatic impacts of energy-peat extraction are of increasing concern due to EU emissions trading requirements. A new excavation-drier peat extraction method has been developed to reduce the climatic impact and increase the efficiency of peat extraction. To quantify and compare the soil GHG fluxes of the excavation drier and the traditional milling methods, as well as the areas from which the energy peat is planned to be extracted in the future (extraction reserve area types), soil CO{sub 2}, CH{sub 4} and N{sub 2}O fluxes were measured during 2006-2007 at three sites in Finland. Within each site, fluxes were measured from drained extraction reserve areas, extraction fields and stockpiles of both methods and additionally from the biomass driers of the excavation-drier method. The Life Cycle Assessment (LCA), described at a principal level in ISO Standards 14040:2006 and 14044:2006, was used to assess the long-term (100 years) climatic impact from peatland utilisation with respect to land use and energy production chains where utilisation of coal was replaced with peat. Coal was used as a reference since in many cases peat and coal can replace each other in same power plants. According to this study, the peat extraction method used was of lesser significance than the extraction reserve area type in regards to the climatic impact. However, the excavation-drier method seems to cause a slightly reduced climatic impact as compared with the prevailing milling method. (orig.)

Experimental research data on stress state of salt rock mass around an underground excavation

Science.gov (United States)

Baryshnikov, VD; Baryshnikov, DV

2018-03-01

The paper presents the experimental stress state data obtained in surrounding salt rock mass around an excavation in Mir Mine, ALROSA. The deformation characteristics and the values of stresses in the adjacent rock mass are determined. Using the method of drilling a pair of parallel holes in a stressed area, the authors construct linear relationship for the radial displacements of the stress measurement hole boundaries under the short-term loading of the perturbing hole. The resultant elasticity moduli of rocks are comparable with the laboratory core test data. Pre-estimates of actual stresses point at the presence of a plasticity zone in the vicinity of the underground excavation. The stress state behavior at a distance from the excavation boundary disagrees with the Dinnik–Geim hypothesis.

Characterization of enameled glass excavated from Laem Pho, southern Thailand

Science.gov (United States)

Dhanmanonda, W.; Won-in, K.; Tancharakorn, S.; Tantanuch, W.; Thongleurm, C.; Kamwanna, T.; Dararutana, P.

2012-07-01

Laem Pho in Surat Thani, southern province of Thailand is one of the most important historic site on the eastern shore of the Gulf of Thailand. In this work, the enameled glass fragments which looked-like Islamic glass mainly excavated from this site were analyzed using SEM-EDS, PIXE and μ-XRF, in order to understand the chemical composition by comparing the archaeological data and topology. The structure of the enameled decoration was also studied. The resulting data indicated that high-magnesia alkali-lime silicate glass was produced. The presence of transition metals such as copper, iron and manganese were affected on the glass colorations. Typological classifications, technological observations and comparative studies serve to clarify the development and cultural inter-relationships of various glass objects along the trade and exchange networks in ancient maritime.

Characterization of enameled glass excavated from Laem Pho, southern Thailand

International Nuclear Information System (INIS)

Dhanmanonda, W; Won-in, K; Tancharakorn, S; Tantanuch, W; Thongleurm, C; Kamwanna, T; Dararutana, P

2012-01-01

Laem Pho in Surat Thani, southern province of Thailand is one of the most important historic site on the eastern shore of the Gulf of Thailand. In this work, the enameled glass fragments which looked-like Islamic glass mainly excavated from this site were analyzed using SEM-EDS, PIXE and μ-XRF, in order to understand the chemical composition by comparing the archaeological data and topology. The structure of the enameled decoration was also studied. The resulting data indicated that high-magnesia alkali-lime silicate glass was produced. The presence of transition metals such as copper, iron and manganese were affected on the glass colorations. Typological classifications, technological observations and comparative studies serve to clarify the development and cultural inter-relationships of various glass objects along the trade and exchange networks in ancient maritime.

Hydraulic tests for the Excavation Disturbed Zone in deep rock mass

International Nuclear Information System (INIS)

Matsuoka, Eiken

1998-03-01

Investigation for characterization of rock properties of the Excavation Disturbed Zone (EDZ) were carried out in 250 m level drift of KAMAISHI Mine. As a part of this investigation, hydraulic tests in the two different sections which were excavated by normal and smooth blasting method respectively, were performed in the vicinity of a drift wall and floor. The test results are as follows, 1) The distribution of pore water pressure in two sections was different. 2) In this investigation, hydraulic test was performed at the different depth in the horizontal and vertical down hole. The variation of measured permeability with depth from the drift wall and floor showed different character. 3) The measured permeability in horizontal hole has no change with depth from drift wall, but in vertical down hole, the measured permeability in nearest part from the floor indicated the higher value compared to the permeability in deeper part. 4) In horizontal holes in two sections there was no difference of the measured permeabilities dependent on the excavation method. The higher permeability was obtained in the vertical hole in smooth blasting section compared to normal blasting section. (author)

Control of stochastic resonance in bistable systems by using periodic signals

International Nuclear Information System (INIS)

Min, Lin; Li-Min, Fang; Yong-Jun, Zheng

2009-01-01

According to the characteristic structure of double wells in bistable systems, this paper analyses stochastic fluctuations in the single potential well and probability transitions between the two potential wells and proposes a method of controlling stochastic resonance by using a periodic signal. Results of theoretical analysis and numerical simulation show that the phenomenon of stochastic resonance happens when the time scales of the periodic signal and the noise-induced probability transitions between the two potential wells achieve stochastic synchronization. By adding a bistable system with a controllable periodic signal, fluctuations in the single potential well can be effectively controlled, thus affecting the probability transitions between the two potential wells. In this way, an effective control can be achieved which allows one to either enhance or realize stochastic resonance

Selection of Excavators for Earth Work on the Basis of their Performance

Science.gov (United States)

Vondráčková, Terezie; Voštová, Věra

2017-10-01

For the specific construction of the reconstruction of the railway section Ostrov nad Oslavou and Žďár nad Sázavou will be done removed the railway superstructure and the partial adjustment of the substructure including drainage. For the earthwork will be used excavators of the company Komatsu, with the possibility of adjustment of parameters of the working tool - the length of the bracket and the volume of the shovel. The determined value will be purely indicative, as it does not affect how the operator of the excavator handles the discharge of cargo means.

The effect of deep excavation-induced lateral soil movements on the behavior of strip footing supported on reinforced sand

Directory of Open Access Journals (Sweden)

Mostafa El Sawwaf

2012-10-01

Full Text Available This paper presents the results of laboratory model tests on the influence of deep excavation-induced lateral soil movements on the behavior of a model strip footing adjacent to the excavation and supported on reinforced granular soil. Initially, the response of the strip footings supported on un-reinforced sand and subjected to vertical loads (which were constant during the test due to adjacent deep excavation-induced lateral soil movement were obtained. Then, the effects of the inclusion of geosynthetic reinforcement in supporting soil on the model footing behavior under the same conditions were investigated. The studied factors include the value of the sustained footing loads, the location of footing relative to the excavation, the affected depth of soil due to deep excavation, and the relative density of sand. Test results indicate that the inclusion of soil reinforcement in the supporting sand significantly decreases both vertical settlements and the tilts of the footings due to the nearby excavation. However, the improvements in the footing behavior were found to be very dependent on the location of the footing relative to excavation. Based on the test results, the variation of the footing measured vertical settlements with different parameters are presented and discussed.

Characterization of the emissions impacts of hybrid excavators with a portable emissions measurement system (PEMS)-based methodology.

Science.gov (United States)

Cao, Tanfeng; Russell, Robert L; Durbin, Thomas D; Cocker, David R; Burnette, Andrew; Calavita, Joseph; Maldonado, Hector; Johnson, Kent C

2018-04-13

Hybrid engine technology is a potentially important strategy for reduction of tailpipe greenhouse gas (GHG) emissions and other pollutants that is now being implemented for off-road construction equipment. The goal of this study was to evaluate the emissions and fuel consumption impacts of electric-hybrid excavators using a Portable Emissions Measurement System (PEMS)-based methodology. In this study, three hybrid and four conventional excavators were studied for both real world activity patterns and tailpipe emissions. Activity data was obtained using engine control module (ECM) and global positioning system (GPS) logged data, coupled with interviews, historical records, and video. This activity data was used to develop a test cycle with seven modes representing different types of excavator work. Emissions data were collected over this test cycle using a PEMS. The results indicated the HB215 hybrid excavator provided a significant reduction in tailpipe carbon dioxide (CO 2 ) emissions (from -13 to -26%), but increased diesel particulate matter (PM) (+26 to +27%) when compared to a similar model conventional excavator over the same duty cycle. Copyright © 2018 Elsevier B.V. All rights reserved.

MPED: An ISRU Bucket Ladder Excavator Demonstrator System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed innovation is a planetary surface tool called the Multi Purpose Excavation Demonstrator (MPED), which is intended to both extract Lunar Soil to feed an...

Drill, baby, drill: the influence of woodpeckers on post-fire vertebrate communities through cavity excavation

Science.gov (United States)

Gina L. Tarbill; Patricia N. Manley; Angela M. White

2015-01-01

Several studies have addressed the importance of woodpeckers as ecological engineers in forests due to their excavation of cavities. Although research in green, unburned forests has identified the influence of different excavators on secondary use by cavity-dependent species, little is known about the relative importance of cavities created by woodpeckers in recently...

End effectors and attachments for buried waste excavation equipment

International Nuclear Information System (INIS)

King, R.H.

1993-09-01

The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that form a comprehensive remediation system for the effective and efficient remediation of buried waste. Their efforts are identified and coordinated in support of the U.S. Department of Energy (DOE), Environmental Restoration and Waste Management (ER ampersand WM) Department's needs and objectives. The present focus of BWID is to support retrieval and ex-situ treatment configuration options. Future activities will explore and support containment, and stabilization efforts in addition to the retrieval/ex situ treatment options. This report presents a literature search on the state-of-the-art in end effectors and attachments in support of excavator of buried transuranic waste. Included in the report are excavator platforms and a discussion of the various attachments. Also included is it list of vendors and specifications

The Method of Validity Evaluation of Hard Coal Excavation in Residual Seam Parts

Science.gov (United States)

Wodarski, Krzysztof; Bijańska, Jolanta; Gumiński, Adam

2017-12-01

The excavation of residual seam parts should be justified by positive assessment of the purposefulness, technical feasibility and economic effectiveness. The results of the profitability evaluation are crucial in a decision making process. The excavation of residual seam parts, even if it is possible from a technical point of view, should not be implemented if it is economically inefficient or when accompanied by a very high risk of non-recovery of invested capital resources. The article presents the evaluation method of possibilities of excavating hard coal from residual seam parts, and the example of its use in one of collieries in the Upper Silesian Coal Basin. Working in line with the developed method, allows to indicate the variant of residual seam part exploitation, which is feasible to implement from a technical point of view, and which is characterized by the highest economic effectiveness and lowest risk.

Archaeological excavation of T10/993 at Matarangi

International Nuclear Information System (INIS)

Furey, L.

1999-01-01

This report describes the excavation of a small midden site, T10/993, representative of a number of like sites in the sand dunes at Matarangi on the east coast of the Coromandel Peninsula. Few sites of this type have been investigated archaeologically yet they are the remains of a very important part of the Maori economic cycle. The sites could be termed shellfish processing sites. The excavation was a condition imposed by Historic Places Trust on the granting of an authority to modify sites T10/993 and 994 (HPT Authority no. 1997/42), prior to destruction of the sites (Furey 1998). Matarangi Beach Estates commissioned the author to undertake an archaeological site survey of a grassed area at Matarangi Beach which was to be Stage 14 of the urban housing development. The area was in excess of 13 hectares. Two sites were found, T10/993 and 994, and recommendations made for monitoring of the dunes as the topsoil was removed (Furey 1997a). (author). 15 refs., 6 figs., 2 tabs

Structured Modeling and Analysis of Stochastic Epidemics with Immigration and Demographic Effects.

Science.gov (United States)

Baumann, Hendrik; Sandmann, Werner

2016-01-01

Stochastic epidemics with open populations of variable population sizes are considered where due to immigration and demographic effects the epidemic does not eventually die out forever. The underlying stochastic processes are ergodic multi-dimensional continuous-time Markov chains that possess unique equilibrium probability distributions. Modeling these epidemics as level-dependent quasi-birth-and-death processes enables efficient computations of the equilibrium distributions by matrix-analytic methods. Numerical examples for specific parameter sets are provided, which demonstrates that this approach is particularly well-suited for studying the impact of varying rates for immigration, births, deaths, infection, recovery from infection, and loss of immunity.

Joint ANDRA/Nirex/SKB zone of excavation disturbance experiment (ZEDEX) at the Aspo hard rock laboratory

International Nuclear Information System (INIS)

Hooper, A.J.; Olsson, O.

1995-01-01

The excavation of access shafts and tunnels and of the disposal areas of a waste repository will cause a disturbance in the surrounding rock mass with possible alterations to rock mass stability and hydraulic properties. For a number of disposal concepts this disturbance may be important for the operational and/or post-closure safety of the repository. Furthermore the disturbance may extend over time as a consequence of processes such as stress relaxation. The sponsors of ZEDEX, namely ANDRA, Nirex and SKB, are interested in developing the ability to produce reliable models of the disturbed zone that will develop around large cross-section excavations in fractured hard rock masses that are initially water saturated. Various models have been developed to calculate the important characteristics of the disturbed zone in such rock masses as a function of parameters related to the rock mass quality and the geometric description of the excavation. ZEDEX was initiated in the Aspo Hard Rock Laboratory in April 1994 with drilling and instrumentation of boreholes running alongside the planned extension of the spiral access ramp and a planned parallel experimental tunnel. ZEDEX has been designed to generate information for alternative methods of excavation. The extension to the spiral ramp is to be made by tunnel boring whereas the parallel experimental tunnel will be excavated in part by ''normal'' basting and in part by smooth blasting. The objective is to build confidence in the modelling of the disturbed zone to support the selection of excavation methods for repository construction. (authors). 3 figs

Numerical Simulation of Rock Mass Damage Evolution During Deep-Buried Tunnel Excavation by Drill and Blast

Science.gov (United States)

Yang, Jianhua; Lu, Wenbo; Hu, Yingguo; Chen, Ming; Yan, Peng

2015-09-01

Presence of an excavation damage zone (EDZ) around a tunnel perimeter is of significant concern with regard to safety, stability, costs and overall performance of the tunnel. For deep-buried tunnel excavation by drill and blast, it is generally accepted that a combination of effects of stress redistribution and blasting is mainly responsible for development of the EDZ. However, few open literatures can be found to use numerical methods to investigate the behavior of rock damage induced by the combined effects, and it is still far from full understanding how, when and to what degree the blasting affects the behavior of the EDZ during excavation. By implementing a statistical damage evolution law based on stress criterion into the commercial software LS-DYNA through its user-subroutines, this paper presents a 3D numerical simulation of the rock damage evolution of a deep-buried tunnel excavation, with a special emphasis on the combined effects of the stress redistribution of surrounding rock masses and the blasting-induced damage. Influence of repeated blast loadings on the damage extension for practical millisecond delay blasting is investigated in the present analysis. Accompanying explosive detonation and secession of rock fragments from their initial locations, in situ stress in the immediate vicinity of the excavation face is suddenly released. The transient characteristics of the in situ stress release and induced dynamic responses in the surrounding rock masses are also highlighted. From the simulation results, some instructive conclusions are drawn with respect to the rock damage mechanism and evolution during deep-buried tunnel excavation by drill and blast.

Nonlocal quantum field theory and stochastic quantum mechanics

International Nuclear Information System (INIS)

Namsrai, K.

1986-01-01

This volume presents a systematic development of the implications to both quantum mechanics and quantum field theory of the hypothesis of a stochastic structure of space-time. Some applications to elementary particle physics are also considered. Part 1 is concerned with nonlocal quantum field theory and, among other topics, deals with quantized fields, electromagnetic and weak processes, the Schroedinger equation, and functional methods and their applications. Part 2 presents an introduction to stochastic mechanics and many specific problems of interest are discussed. (Auth.)

What Shapes the Phylogenetic Structure of Anuran Communities in a Seasonal Environment? The Influence of Determinism at Regional Scale to Stochasticity or Antagonistic Forces at Local Scale.

Science.gov (United States)

Martins, Clarissa de Araújo; Roque, Fabio de Oliveira; Santos, Bráulio A; Ferreira, Vanda Lúcia; Strüssmann, Christine; Tomas, Walfrido Moraes

2015-01-01

Ecological communities are structured by both deterministic and stochastic processes. We investigated phylogenetic patterns at regional and local scales to understand the influences of seasonal processes in shaping the structure of anuran communities in the southern Pantanal wetland, Brazil. We assessed the phylogenetic structure at different scales, using the Net Relatedness Index (NRI), the Nearest Taxon Index (NTI), and phylobetadiversity indexes, as well as a permutation test, to evaluate the effect of seasonality. The anuran community was represented by a non-random set of species with a high degree of phylogenetic relatedness at the regional scale. However, at the local scale the phylogenetic structure of the community was weakly related with the seasonality of the system, indicating that oriented stochastic processes (e.g. colonization, extinction and ecological drift) and/or antagonist forces drive the structure of such communities in the southern Pantanal.

The Excavation and Remediation of the Sandia National Laboratories Chemical Waste Landfill

International Nuclear Information System (INIS)

KWIECINSKI, DANIEL ALBERT; METHVIN, RHONDA KAY; SCHOFIELD, DONALD P.; YOUNG, SHARISSA G.

1999-01-01

The Chemical Waste Landfill (CWL) at Sandia National Laboratories/New Mexico (SNL/NM) is a 1.9-acre disposal site that was used for the disposal of chemical wastes generated by many of SNL/NM research laboratories from 1962 until 1985. These laboratories were primarily involved in the design, research and development of non-nuclear components of nuclear weapons and the waste generated by these labs included small quantities of a wide assortment of chemical products. A Resource Conservation and Recovery Act (RCRA) Closure Plan for the Chemical Waste Landfill was approved by the New Mexico Environment Department (NMED) in 1992. Subsequent site characterization activities identified the presence of significant amounts of chromium in the soil as far as 80 feet below ground surface (fbgs) and the delineation of a solvent plume in the vadose zone that extends to groundwater approximately 500 fbgs. Trichloroethylene (TCE) was detected in some groundwater samples at concentrations slightly above the drinking water limit of 5 parts per billion. In 1997 an active vapor extraction system reduced the size of the TCE vapor plume and for the last six quarterly sampling events groundwater samples have not detected TCE above the drinking water standard. A source term removal, being conducted as a Voluntary Corrective Measure (VCM), began in September 1998 and is expected to take up to two years. Four distinct disposal areas were identified from historical data and the contents of disposal pits and trenches in these areas, in addition to much of the highly contaminated soil surrounding the disposal cells, are currently being excavated. Buried waste and debris are expected to extend to a depth of 12 to 15 fbgs. Excavation will focus on the removal of buried debris and contaminated soil in a sequential, area by area manner and will proceed to whatever depth is required in order to remove all pit contents. Up to 50,000 cubic yards of soil and debris will be removed and managed during

Predictive modelling of an excavation test in indurated clay

International Nuclear Information System (INIS)

Garitte, B.; Vaunat, J.; Gens, A.; Vietor, T.

2010-01-01

Document available in extended abstract form only. This Abstract presents the predictive hydro-mechanical (HM) modelling of an excavation performed in Opalinus clay in the Mont Terri underground laboratory. Niche 2 was excavated in the shaly facies of Opalinus clay from gallery 08. The area surrounding the gallery was intensively instrumented. The geology of Mont Terri is described in Thury and Bosssart (1999) and the parameters used in the analysis were taken from Bock (2009). The stress state is derived from Martin and Lanyion (2003). Gallery 08 is horseshoe shaped and has a mean radius of 2.25 m. It was excavated with a road header at a mean velocity of 1 m/day starting on January 30, 2008 (Gallery chainage 43.8) and ending on June 30, 2008 (Gallery chainage 123.8) with a stop from March 18, to April 24, to instrument the area of niche 2. Niche 2 was excavated by successive blastings 1.3 m deep until reaching a distance of 24 m from the gallery 08 wall. Advance was continuous from October 13, to November 7 with the exception of three stops of 3, 5 and 4 days. The niche has an average diameter of 4.5 m and has a slight upward slope of 0.98%. The excavation of gallery 08 from chainage 43.8 to chainage 123.8 and of the niche was simulated by relaxing the normal total stress and water pressure from the value before excavation to 0. The gallery advance rate was simulated in an approximate manner by applying successively the excavation procedure to 9 m long gallery sections. In the case of the niche, the blasting scheme and the application of the shotcrete was closely reproduced. The three dimensional geometry used in the simulation is shown. The coupled hydro-mechanical formulation used for the analysis is based on the simultaneous solution of the balance equation for solid mass, water mass and momentum (equilibrium). In accordance with field observations, it has been assumed that the medium remains saturated throughout. The formulation was completed with a number of

Remote Excavation of Heavily Contaminated UXO Sites. The Range Master

National Research Council Canada - National Science Library

Crandall, Alan L

2007-01-01

USA Environmental, Inc., and Timberline Environmental Services, Inc., developed the Range Master, a remote controlled scraper with an integrated power screen, to excavate and sift the top 12 inches of heavily contaminated UXO sites...

Multilayer Stochastic Block Models Reveal the Multilayer Structure of Complex Networks

Directory of Open Access Journals (Sweden)

Toni Vallès-Català

2016-03-01

Full Text Available In complex systems, the network of interactions we observe between systems components is the aggregate of the interactions that occur through different mechanisms or layers. Recent studies reveal that the existence of multiple interaction layers can have a dramatic impact in the dynamical processes occurring on these systems. However, these studies assume that the interactions between systems components in each one of the layers are known, while typically for real-world systems we do not have that information. Here, we address the issue of uncovering the different interaction layers from aggregate data by introducing multilayer stochastic block models (SBMs, a generalization of single-layer SBMs that considers different mechanisms of layer aggregation. First, we find the complete probabilistic solution to the problem of finding the optimal multilayer SBM for a given aggregate-observed network. Because this solution is computationally intractable, we propose an approximation that enables us to verify that multilayer SBMs are more predictive of network structure in real-world complex systems.

Robotic excavator trajectory control using an improved GA based PID controller

Science.gov (United States)

Feng, Hao; Yin, Chen-Bo; Weng, Wen-wen; Ma, Wei; Zhou, Jun-jing; Jia, Wen-hua; Zhang, Zi-li

2018-05-01

In order to achieve excellent trajectory tracking performances, an improved genetic algorithm (IGA) is presented to search for the optimal proportional-integral-derivative (PID) controller parameters for the robotic excavator. Firstly, the mathematical model of kinematic and electro-hydraulic proportional control system of the excavator are analyzed based on the mechanism modeling method. On this basis, the actual model of the electro-hydraulic proportional system are established by the identification experiment. Furthermore, the population, the fitness function, the crossover probability and mutation probability of the SGA are improved: the initial PID parameters are calculated by the Ziegler-Nichols (Z-N) tuning method and the initial population is generated near it; the fitness function is transformed to maintain the diversity of the population; the probability of crossover and mutation are adjusted automatically to avoid premature convergence. Moreover, a simulation study is carried out to evaluate the time response performance of the proposed controller, i.e., IGA based PID against the SGA and Z-N based PID controllers with a step signal. It was shown from the simulation study that the proposed controller provides the least rise time and settling time of 1.23 s and 1.81 s, respectively against the other tested controllers. Finally, two types of trajectories are designed to validate the performances of the control algorithms, and experiments are performed on the excavator trajectory control experimental platform. It was demonstrated from the experimental work that the proposed IGA based PID controller improves the trajectory accuracy of the horizontal line and slope line trajectories by 23.98% and 23.64%, respectively in comparison to the SGA tuned PID controller. The results further indicate that the proposed IGA tuning based PID controller is effective for improving the tracking accuracy, which may be employed in the trajectory control of an actual excavator.

Pricing long-dated insurance contracts with stochastic interest rates and stochastic volatility

NARCIS (Netherlands)

van Haastrecht, A.; Lord, R.; Pelsser, A.; Schrager, D.

2009-01-01

We consider the pricing of long-dated insurance contracts under stochastic interest rates and stochastic volatility. In particular, we focus on the valuation of insurance options with long-term equity or foreign exchange exposures. Our modeling framework extends the stochastic volatility model of

Semi-analytical stochastic analysis of the generalized van der Pol system

Czech Academy of Sciences Publication Activity Database

Náprstek, Jiří; Fischer, Cyril

(2018) ISSN 1802-680X R&D Projects: GA ČR(CZ) GA15-01035S Institutional support: RVO:68378297 Keywords : stochastic stability * generalized van der Pol system * stochastic averaging * limit cycles Subject RIV: JM - Building Engineering OBOR OECD: Construction engineering, Municipal and structural engineering https://www.kme.zcu.cz/acm/acm/article/view/407

Characteristics of the excavation response zone as applied to shaft sealing

International Nuclear Information System (INIS)

Jakubick, A.T.; Klein, R.; Gray, M.N.; Keil, L.D.

1989-01-01

Effective sealing of an underground repository requires high quality seals. Clay-based backfills in combination with cement plugs are the possible candidates. An important component of the shaft sealing program is the development of techniques to predict and monitor the flow in the excavation response zone (ERZ) and at the seal-rock interface. The mechanical and hydraulic performance of the seal and backfill and the flow characteristics of the ERZ under in situ conditions will be tested in three experimental shafts to be excavated in the URL. The use of the vacuum permeability technique for characterization of the hydraulic properties and of the permeability distribution in the ERZ under various geomechanical conditions is discussed

The influence of cathode excavation of cathodic arc evaporator on thickness uniformity and erosion products angle distribution

Directory of Open Access Journals (Sweden)

D. V. Duhopel'nikov

2014-01-01

Full Text Available Cathodic arc evaporators are used for coating with functional films. Prolonged or buttend evaporators may be used for this purposes. In butt-end evaporator the cathode spots move continuously on the cathode work surface and evaporate cathode material. High depth excavation profile forms on the cathode work surface while the thick coating precipitation (tens or hundreds of microns. The cathode excavation profile is shaped like a “cup” with high walls for electrostatic discharge stabilization systems with axial magnetic fields. Cathode spots move on the bottom of the “cup”. It is very likely that high “cup” walls are formed as a result of lasting work time influence on the uniformity of precipitated films.In the present work the influence of excavation profile walls height on the uniformity of precipitated coating was carried out. The high profile walls are formed due to lasting work of DC vacuum arc evaporator. The cathode material used for tests was 3003 aluminum alloy. The extended substrate was placed parallel to the cathode work surface. Thickness distribution along the substrate length with the new cathode was obtained after 6 hours and after 12 hours of continuous operation.The thickness distribution of precipitated coating showed that the cathode excavation has an influence on the angular distribution of the matter escaping the cathode. It can be clearly seen from the normalized dependence coating thickness vs the distance from the substrate center. Also the angular distribution of the matter flow from the cathode depending on the cathode working time was obtained. It was shown that matter flow from the cathode differs from the LambertKnudsen law. The more the cathode excavation the more this difference.So, cathode excavation profile has an influence on the uniformity of precipitated coating and it is necessary to take in account the cathode excavation profile while coating the thick films.

Stochastic thermodynamics

Science.gov (United States)

Eichhorn, Ralf; Aurell, Erik

2014-04-01

'Stochastic thermodynamics as a conceptual framework combines the stochastic energetics approach introduced a decade ago by Sekimoto [1] with the idea that entropy can consistently be assigned to a single fluctuating trajectory [2]'. This quote, taken from Udo Seifert's [3] 2008 review, nicely summarizes the basic ideas behind stochastic thermodynamics: for small systems, driven by external forces and in contact with a heat bath at a well-defined temperature, stochastic energetics [4] defines the exchanged work and heat along a single fluctuating trajectory and connects them to changes in the internal (system) energy by an energy balance analogous to the first law of thermodynamics. Additionally, providing a consistent definition of trajectory-wise entropy production gives rise to second-law-like relations and forms the basis for a 'stochastic thermodynamics' along individual fluctuating trajectories. In order to construct meaningful concepts of work, heat and entropy production for single trajectories, their definitions are based on the stochastic equations of motion modeling the physical system of interest. Because of this, they are valid even for systems that are prevented from equilibrating with the thermal environment by external driving forces (or other sources of non-equilibrium). In that way, the central notions of equilibrium thermodynamics, such as heat, work and entropy, are consistently extended to the non-equilibrium realm. In the (non-equilibrium) ensemble, the trajectory-wise quantities acquire distributions. General statements derived within stochastic thermodynamics typically refer to properties of these distributions, and are valid in the non-equilibrium regime even beyond the linear response. The extension of statistical mechanics and of exact thermodynamic statements to the non-equilibrium realm has been discussed from the early days of statistical mechanics more than 100 years ago. This debate culminated in the development of linear response

Stochastic Gravity: Theory and Applications

Directory of Open Access Journals (Sweden)

Hu Bei Lok

2004-01-01

Full Text Available Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. The noise kernel is the vacuum expectation value of the (operator-valued stress-energy bi-tensor which describes the fluctuations of quantum matter fields in curved spacetimes. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity, showing the link from the mean value of the stress-energy tensor to their correlation functions. The functional approach uses the Feynman-Vernon influence functional and the Schwinger-Keldysh closed-time-path effective action methods which are convenient for computations. It also brings out the open systems concepts and the statistical and stochastic contents of the theory such as dissipation, fluctuations, noise, and decoherence. We then focus on the properties of the stress-energy bi-tensor. We obtain a general expression for the noise kernel of a quantum field defined at two distinct points in an arbitrary curved spacetime as products of covariant derivatives of the quantum field's Green function. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime. We offer an analytical solution of the Einstein-Langevin equation and compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint, which can go beyond the standard treatment by incorporating the full quantum effect of the inflaton fluctuations. Third, we discuss the backreaction

Review of excavation methods and their implications for the near-field barrier of a deep underground repository

International Nuclear Information System (INIS)

Young, D.K.

1993-01-01

The report reviews excavation techniques for use in the construction of deep underground radioactive waste repositories, gives a summary of responses of the host rock to excavation and the means of measuring that response and discusses techniques for predicting that response. The review of excavation techniques included technical developments and current practice. To this end an extensive database was developed reviewing major excavations in rock types relevant to disposal and the techniques employed. Creation of an underground opening alters the properties of the rock mass around it. This study identifies stress, displacement, rock mass deformability and permeability as key parameters and reviews how they may be determined. Finally the report discusses the techniques available for predicting the behaviour of the near-field host rock. This concentrates on methods of numerical analysis since existing empirical or analytical methods are not considered suitable. (author)

Structured Modeling and Analysis of Stochastic Epidemics with Immigration and Demographic Effects.

Directory of Open Access Journals (Sweden)

Hendrik Baumann

Full Text Available Stochastic epidemics with open populations of variable population sizes are considered where due to immigration and demographic effects the epidemic does not eventually die out forever. The underlying stochastic processes are ergodic multi-dimensional continuous-time Markov chains that possess unique equilibrium probability distributions. Modeling these epidemics as level-dependent quasi-birth-and-death processes enables efficient computations of the equilibrium distributions by matrix-analytic methods. Numerical examples for specific parameter sets are provided, which demonstrates that this approach is particularly well-suited for studying the impact of varying rates for immigration, births, deaths, infection, recovery from infection, and loss of immunity.

Portfolio Optimization with Stochastic Dividends and Stochastic Volatility

Science.gov (United States)

Varga, Katherine Yvonne

2015-01-01

We consider an optimal investment-consumption portfolio optimization model in which an investor receives stochastic dividends. As a first problem, we allow the drift of stock price to be a bounded function. Next, we consider a stochastic volatility model. In each problem, we use the dynamic programming method to derive the Hamilton-Jacobi-Bellman…

MARSAME Radiological Release Report for Archaeological Artifacts Excavated from Area L

Energy Technology Data Exchange (ETDEWEB)

Ruedig, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Whicker, Jeffrey Jay [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gillis, Jessica Mcdonnel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-06-03

In 1991 Los Alamos National Laboratory’s (LANL’s) cultural resources team excavated archaeological site LA 4618 located at Technical Area 54, within Material Disposal Area L (MDA L). MDA L received non-radioactive chemical waste from the early 1960s until 1985. Further development of the MDA required excavation of several cultural sites under National Historic Preservation Act requirements; artifacts from these sites have been subsequently stored at LANL. The LANL cultural resources group would now like to release these artifacts to the Museum of Indian Arts and Culture in Santa Fe for curation. The history of disposal at Area L suggests that the artifact pool is unlikely to be chemically contaminated and LANL staff washed each artifact at least once following excavation. Thus, it is unlikely that the artifacts present a chemical hazard. LANL’s Environmental Stewardship group (EPC-ES) has evaluated the radiological survey results for the Area L artifact pool and found that the items described in this report meet the criteria for unrestricted radiological release under Department of Energy (DOE) Order 458.1 Radiation Protection of the Public and the Environment and are candidates for release without restriction from LANL control. This conclusion is based on the known history of MDA L and on radiation survey data.

DEM modeling of failure mechanisms induced by excavations on the Moon

Science.gov (United States)

jiang, mingjing; shen, zhifu; Utili, Stefano

2013-04-01

2D Discrete Element Method (DEM) analyses were performed for excavations supported by retaining walls in lunar environment. The lunar terrain is made of a layer of sand (regolith) which differs from terrestrial sands for two main features: the presence of adhesive attractive forces due to van der Waals interactions and grains being very irregular in shape leading to high interlocking. A simplified contact model based on linear elasticity and perfect plasticity was employed. The contact model includes a moment - relative rotation law to account for high interlocking among grains and a normal adhesion law to account for the van der Waals interactions. Analyses of the excavations were run under both lunar and terrestrial environments. Under lunar environment, gravity is approximately one sixth than the value on Earth and adhesion forces between grains of lunar regolith due to van der Waals interactions are not negligible. From the DEM simulations it emerged that van der Waals interactions may significantly increase the bending moment and deflection of the retaining wall, and the ground displacements. Hence this study indicates that an unsafe estimate of the wall response to an excavation on the Moon would be obtained from physical experiments performed in a terrestrial environment, i.e., considering the effect of gravity but neglecting the van der Waals interactions.

Momentum and Stochastic Momentum for Stochastic Gradient, Newton, Proximal Point and Subspace Descent Methods

KAUST Repository

Loizou, Nicolas

2017-12-27

In this paper we study several classes of stochastic optimization algorithms enriched with heavy ball momentum. Among the methods studied are: stochastic gradient descent, stochastic Newton, stochastic proximal point and stochastic dual subspace ascent. This is the first time momentum variants of several of these methods are studied. We choose to perform our analysis in a setting in which all of the above methods are equivalent. We prove global nonassymptotic linear convergence rates for all methods and various measures of success, including primal function values, primal iterates (in L2 sense), and dual function values. We also show that the primal iterates converge at an accelerated linear rate in the L1 sense. This is the first time a linear rate is shown for the stochastic heavy ball method (i.e., stochastic gradient descent method with momentum). Under somewhat weaker conditions, we establish a sublinear convergence rate for Cesaro averages of primal iterates. Moreover, we propose a novel concept, which we call stochastic momentum, aimed at decreasing the cost of performing the momentum step. We prove linear convergence of several stochastic methods with stochastic momentum, and show that in some sparse data regimes and for sufficiently small momentum parameters, these methods enjoy better overall complexity than methods with deterministic momentum. Finally, we perform extensive numerical testing on artificial and real datasets, including data coming from average consensus problems.

Momentum and Stochastic Momentum for Stochastic Gradient, Newton, Proximal Point and Subspace Descent Methods

KAUST Repository

Loizou, Nicolas; Richtarik, Peter

2017-01-01

In this paper we study several classes of stochastic optimization algorithms enriched with heavy ball momentum. Among the methods studied are: stochastic gradient descent, stochastic Newton, stochastic proximal point and stochastic dual subspace ascent. This is the first time momentum variants of several of these methods are studied. We choose to perform our analysis in a setting in which all of the above methods are equivalent. We prove global nonassymptotic linear convergence rates for all methods and various measures of success, including primal function values, primal iterates (in L2 sense), and dual function values. We also show that the primal iterates converge at an accelerated linear rate in the L1 sense. This is the first time a linear rate is shown for the stochastic heavy ball method (i.e., stochastic gradient descent method with momentum). Under somewhat weaker conditions, we establish a sublinear convergence rate for Cesaro averages of primal iterates. Moreover, we propose a novel concept, which we call stochastic momentum, aimed at decreasing the cost of performing the momentum step. We prove linear convergence of several stochastic methods with stochastic momentum, and show that in some sparse data regimes and for sufficiently small momentum parameters, these methods enjoy better overall complexity than methods with deterministic momentum. Finally, we perform extensive numerical testing on artificial and real datasets, including data coming from average consensus problems.

Stochastic neuron models

CERN Document Server

Greenwood, Priscilla E

2016-01-01

This book describes a large number of open problems in the theory of stochastic neural systems, with the aim of enticing probabilists to work on them. This includes problems arising from stochastic models of individual neurons as well as those arising from stochastic models of the activities of small and large networks of interconnected neurons. The necessary neuroscience background to these problems is outlined within the text, so readers can grasp the context in which they arise. This book will be useful for graduate students and instructors providing material and references for applying probability to stochastic neuron modeling. Methods and results are presented, but the emphasis is on questions where additional stochastic analysis may contribute neuroscience insight. An extensive bibliography is included. Dr. Priscilla E. Greenwood is a Professor Emerita in the Department of Mathematics at the University of British Columbia. Dr. Lawrence M. Ward is a Professor in the Department of Psychology and the Brain...

Toxic hazards of underground excavation

International Nuclear Information System (INIS)

Smith, R.; Chitnis, V.; Damasian, M.

1982-09-01

Inadvertent intrusion into natural or man-made toxic or hazardous material deposits as a consequence of activities such as mining, excavation or tunnelling has resulted in numerous deaths and injuries in this country. This study is a preliminary investigation to identify and document instances of such fatal or injurious intrusion. An objective is to provide useful insights and information related to potential hazards due to future intrusion into underground radioactive-waste-disposal facilities. The methodology used in this study includes literature review and correspondence with appropriate government agencies and organizations. Key categories of intrusion hazards are asphyxiation, methane, hydrogen sulfide, silica and asbestos, naturally occurring radionuclides, and various mine or waste dump related hazards

Toxic hazards of underground excavation

Energy Technology Data Exchange (ETDEWEB)

Smith, R.; Chitnis, V.; Damasian, M.; Lemm, M.; Popplesdorf, N.; Ryan, T.; Saban, C.; Cohen, J.; Smith, C.; Ciminesi, F.

1982-09-01

Inadvertent intrusion into natural or man-made toxic or hazardous material deposits as a consequence of activities such as mining, excavation or tunnelling has resulted in numerous deaths and injuries in this country. This study is a preliminary investigation to identify and document instances of such fatal or injurious intrusion. An objective is to provide useful insights and information related to potential hazards due to future intrusion into underground radioactive-waste-disposal facilities. The methodology used in this study includes literature review and correspondence with appropriate government agencies and organizations. Key categories of intrusion hazards are asphyxiation, methane, hydrogen sulfide, silica and asbestos, naturally occurring radionuclides, and various mine or waste dump related hazards.

Stochastic equations theory and applications in acoustics, hydrodynamics, magnetohydrodynamics, and radiophysics

CERN Document Server

Klyatskin, Valery I

2015-01-01

This monograph set presents a consistent and self-contained framework of stochastic dynamic systems with maximal possible completeness. Volume 1 presents the basic concepts, exact results, and asymptotic approximations of the theory of stochastic equations on the basis of the developed functional approach. This approach offers a possibility of both obtaining exact solutions to stochastic problems for a number of models of fluctuating parameters and constructing various asymptotic buildings. Ideas of statistical topography are used to discuss general issues of generating coherent structures from chaos with probability one, i.e., almost in every individual realization of random parameters. The general theory is illustrated with certain problems and applications of stochastic mathematical physics in various fields such as mechanics, hydrodynamics, magnetohydrodynamics, acoustics, optics, and radiophysics.  

Grimsel test site. Excavation disturbed zone experiment (EDZ)

International Nuclear Information System (INIS)

Frieg, B.; Blaser, P. C.; Adams, J.; Dollinger, H.; Kuhlmann, U.; Lanyon, G. W.

2012-07-01

The ‘Excavation Disturbed Zone (EDZ) Experiment’ was conducted at the Grimsel Test Site (GTS) in the framework of safety analysis of deep geological repositories for radioactive wastes. It concentrated on investigating the hydraulic regime of the near-field of drilled tunnel sections under fully saturated conditions, with the aim of contributing to the development of methods for measuring and modelling axial water flow along tunnels and caverns. The studies focused on the mechanical and hydraulic properties of the rock mass in the direct vicinity of the tunnel wall. The EDZ is defined as the zone around the tunnel where excavation has altered the rock properties. The selected test location was a tunnel section where mechanical stressing of the rock and some breakouts had been observed. In-situ stress measurements were performed in order to record the actual stress redistribution in the tunnel near-field induced by excavation of the tunnel. A small stress increase and microfissures could be identified in the tunnel near-field. The stress measurements and the results of the geological mapping formed the basis for the rock mechanical modelling of the EDZ. Two different models of the development and geometry of the EDZ were used: (a) the regional 3D stress field modelling indicated that the topography has a significant influence on the primary stress field; a good agreement between the measured and calculated stresses in the GTS was achieved by applying an additional far-field tectonic stress component; (b) with the local 2D numerical disturbed zone modelling of the tunnel section itself, stress redistributions, possible plastifications and joint behaviour were investigated; all displacements of the rock matrix and the shear displacements of the discontinuities seem to be the result of the tunnel excavation; maximum shear deformations of 2 - 5 mm occur at the tunnel wall. Prior to the hydraulic test phase, the test location was decoupled from the normal GTS tunnel

ZEDEX - A study of damage and disturbance from tunnel excavation by blasting and tunnel boring

International Nuclear Information System (INIS)

Emsley, S.; Olsson, Olle; Stenberg, L.; Alheid, H.J.; Falls, S.

1997-12-01

The objectives of the ZEDEX project were to understand the mechanical behaviour of the excavation disturbed zone (EDZ) with respect to its origin, character, magnitude of property change, extent and its dependence on excavation method. Excavation with normal smooth blasting, blasting with low shock explosives and tunnel boring were studied. The drifts are located at Aespoe at a depth of 420 m, the profiles are circular and 5 m in diameter. The results have shown that there is a damaged zone, close to the drift wall dominated by changes in rock properties which are irreversible, and that there is a disturbed zone beyond the damaged zone that is dominated by changes in stress state and mainly reversible. There is no distinct boundary between the two zones. The results from ZEDEX indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The extent of the damaged zone can be limited through application of appropriate excavation methods. By limiting the extent of the damaged zone it should also be feasible to block pathways in the damaged zone by plugs placed at strategic locations

Endoscopic excavation for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

Science.gov (United States)

Ye, Li-ping; Zhu, Lin-hong; Zhou, Xian-bin; Mao, Xin-li; Zhang, Yu

2015-01-01

This study was designed to evaluate the safety and efficacy of endoscopic excavation for esophageal subepithelial tumors originating from the muscularis propria. Forty-five patients with esophageal subepithelial tumors originating from the muscularis propria were treated with endoscopic excavation between January 2010 and June 2012. The key steps were: (1) making several dots around the tumor; (2) incising the mucosa along with the marker dots, and then seperating the tumor from the muscularis propria by using a hook knife or an insulated-tip knife; (3) closing the artificial ulcer with clips after the tumor was removed. The mean tumor diameter was 1.1 ± 0.6 cm. Endoscopic excavation was successfully performed in 43 out of 45 cases (95.6%), the other 2 cases were ligated with nylon rope. During the procedure perforation occurred in 4 (8.9%) patients, who recovered after conservative treatment. No massive bleeding or delayed bleeding occurred. Histologic diagnosis was obtained from 43 (95.6%) patients. Pathological diagnoses of these tumors were leiomyomas (38/43) and gastrointestinal stromal tumors (5/43). Endoscopic excavation is a safe and effective method for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

ZEDEX - A study of damage and disturbance from tunnel excavation by blasting and tunnel boring

Energy Technology Data Exchange (ETDEWEB)

Emsley, S [Golder Associates, Maidenhead (United Kingdom); Olsson, Olle; Stenberg, L [Swedish Nuclear Fuel and Waste Co., Figeholm (Sweden); Alheid, H J [Federal Inst. for Geosciences and Natural Resources, Hannover (Germany); Falls, S [Queens Univ., Kingston, ON (Canada)

1997-12-01

The objectives of the ZEDEX project were to understand the mechanical behaviour of the excavation disturbed zone (EDZ) with respect to its origin, character, magnitude of property change, extent and its dependence on excavation method. Excavation with normal smooth blasting, blasting with low shock explosives and tunnel boring were studied. The drifts are located at Aespoe at a depth of 420 m, the profiles are circular and 5 m in diameter. The results have shown that there is a damaged zone, close to the drift wall dominated by changes in rock properties which are irreversible, and that there is a disturbed zone beyond the damaged zone that is dominated by changes in stress state and mainly reversible. There is no distinct boundary between the two zones. The results from ZEDEX indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The extent of the damaged zone can be limited through application of appropriate excavation methods. By limiting the extent of the damaged zone it should also be feasible to block pathways in the damaged zone by plugs placed at strategic locations 68 refs, 92 figs, 31 tabs

Archaeological Excavation Report for Proposed Well 199-K-131 in Support of the 100-KR-4 Pump-and-Treat Project

Energy Technology Data Exchange (ETDEWEB)

Woody, Dave M.; Prendergast-Kennedy, Ellen L.

2004-06-22

An archaeological excavation was conducted at the site of proposed groundwater monitoring well 199-K-131 in support of the 100-KR-4 Pump-and-Treat Project between June 2 and 3, 2004. Excavations confirmed that there were no intact cultural deposits at the proposed well location. This report was prepared to document the findings of the test excavation.

Stochastic tools in turbulence

CERN Document Server

Lumey, John L

2012-01-01

Stochastic Tools in Turbulence discusses the available mathematical tools to describe stochastic vector fields to solve problems related to these fields. The book deals with the needs of turbulence in relation to stochastic vector fields, particularly, on three-dimensional aspects, linear problems, and stochastic model building. The text describes probability distributions and densities, including Lebesgue integration, conditional probabilities, conditional expectations, statistical independence, lack of correlation. The book also explains the significance of the moments, the properties of the

The stochastic spectator

Energy Technology Data Exchange (ETDEWEB)

Hardwick, Robert J.; Vennin, Vincent; Wands, David [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Byrnes, Christian T.; Torrado, Jesús, E-mail: robert.hardwick@port.ac.uk, E-mail: vincent.vennin@port.ac.uk, E-mail: c.byrnes@sussex.ac.uk, E-mail: jesus.torrado@sussex.ac.uk, E-mail: david.wands@port.ac.uk [Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom)

2017-10-01

We study the stochastic distribution of spectator fields predicted in different slow-roll inflation backgrounds. Spectator fields have a negligible energy density during inflation but may play an important dynamical role later, even giving rise to primordial density perturbations within our observational horizon today. During de-Sitter expansion there is an equilibrium solution for the spectator field which is often used to estimate the stochastic distribution during slow-roll inflation. However slow roll only requires that the Hubble rate varies slowly compared to the Hubble time, while the time taken for the stochastic distribution to evolve to the de-Sitter equilibrium solution can be much longer than a Hubble time. We study both chaotic (monomial) and plateau inflaton potentials, with quadratic, quartic and axionic spectator fields. We give an adiabaticity condition for the spectator field distribution to relax to the de-Sitter equilibrium, and find that the de-Sitter approximation is never a reliable estimate for the typical distribution at the end of inflation for a quadratic spectator during monomial inflation. The existence of an adiabatic regime at early times can erase the dependence on initial conditions of the final distribution of field values. In these cases, spectator fields acquire sub-Planckian expectation values. Otherwise spectator fields may acquire much larger field displacements than suggested by the de-Sitter equilibrium solution. We quantify the information about initial conditions that can be obtained from the final field distribution. Our results may have important consequences for the viability of spectator models for the origin of structure, such as the simplest curvaton models.

The stochastic spectator

International Nuclear Information System (INIS)

Hardwick, Robert J.; Vennin, Vincent; Wands, David; Byrnes, Christian T.; Torrado, Jesús

2017-01-01

We study the stochastic distribution of spectator fields predicted in different slow-roll inflation backgrounds. Spectator fields have a negligible energy density during inflation but may play an important dynamical role later, even giving rise to primordial density perturbations within our observational horizon today. During de-Sitter expansion there is an equilibrium solution for the spectator field which is often used to estimate the stochastic distribution during slow-roll inflation. However slow roll only requires that the Hubble rate varies slowly compared to the Hubble time, while the time taken for the stochastic distribution to evolve to the de-Sitter equilibrium solution can be much longer than a Hubble time. We study both chaotic (monomial) and plateau inflaton potentials, with quadratic, quartic and axionic spectator fields. We give an adiabaticity condition for the spectator field distribution to relax to the de-Sitter equilibrium, and find that the de-Sitter approximation is never a reliable estimate for the typical distribution at the end of inflation for a quadratic spectator during monomial inflation. The existence of an adiabatic regime at early times can erase the dependence on initial conditions of the final distribution of field values. In these cases, spectator fields acquire sub-Planckian expectation values. Otherwise spectator fields may acquire much larger field displacements than suggested by the de-Sitter equilibrium solution. We quantify the information about initial conditions that can be obtained from the final field distribution. Our results may have important consequences for the viability of spectator models for the origin of structure, such as the simplest curvaton models.

Excavation of the Surikamigawa dam diversion tunnel. Surikamigawa dam karihaisui tunnel kantsu

Energy Technology Data Exchange (ETDEWEB)

Ikeda, T.; Konno, T. (Ministry of Construction, Tokyo (Japan))

1994-04-01

A bypass tunnel construction has been completed at the Surikamigawa dam (Japan). This paper describes the summary of the construction. The full-swing dam construction work is scheduled to begin in 1995. The soils distributed near the dam site consist of lapillus tuff containing andesite-based light stones and tuff-based conglomerates containing large gravels. Excavation of the dam diversion tunnel has used a blasting method, and the tunnel construction has adopted an automatic tunnel cross section marking system and a non-electric explosion method. This marking system is a system to irradiate a laser beam onto the facing to depict excavation lines that realizes labor saving and high-accuracy excavation. The error at the tunnel completion was found 20 mm. The non-electric explosion method ignites a coated explosive layer with an impact wave, which is electrostatically safe, and reduces blasting vibration. Electric detonators have also been used because of using ANFO explosives. The result obtained from measurements of inner space displacement necessary for the blasting process has indicated that the area near the dam site consists of stable mountains. 6 figs., 4 tabs.

Predictive hydro-mechanical excavation simulation of a mine-by test at the Mont Terri rock laboratory

International Nuclear Information System (INIS)

Krug, St.; Shao, H.; Hesser, J.; Nowak, T.; Kunz, H.; Vietor, T.

2010-01-01

Document available in extended abstract form only. The Mont Terri rock laboratory was extended from mid October 2007 to end 2008 with the goal to allow the project partners to continue their cooperative research on the long term. The extension of the underground laboratory by the excavation of an additional 165 metres long access tunnel (Gallery 08) with four niches was taken as opportunity to conduct an instrumented mine-by test in one of the niches (Niche 2/Niche MB). The measurements during the bedding parallel excavation provided a large amount of data as a basis to understand the hydro-mechanical (HM) coupled behaviour of Opalinus Clay around the excavated niche. BGR was involved in the in-situ investigations (seismic measurements) as a member of the experiment team consisting of five organisations (incl. NAGRA, ANDRA, GRS, Obayashi). An important issue for BGR is the application of the numerical code RockFlow (RF) for HM coupled simulations in order to understand the behaviour of Opalinus Clay by the use of the gained measuring data for validation. Under the management of NAGRA a blind prediction was carried out for a group of modelers belonging to some of the experiment team organisations. After a first comparison between the numerical results of different HM coupled models during the prediction meeting of the teams in June 2009 the measurement data are provided by NAGRA in order to validate the numerical models. Basically the model predictions have already shown the correct tendencies and ranges of observed deformation and pore water pressure evolution besides some under- or overestimations. The future RF validation results after having done some slight parameter adjustments are intended to be presented in the paper. The excavation of Niche 2 was done from 13 October to 7 November 2008 with a constant excavation rate of 1.30 m per day. The orientation of the niche follows the bedding strike, which amounts 60 deg.. The bedding planes have an average dip of

Monitoring the Excavation Damaged Zone in Opalinus clay by three dimensional reconstruction of the electrical resistivity in the Mont Terri gallery G-04

Science.gov (United States)

Lesparre, N.; Adler, A.; Nicollin, F.; Gibert, D.; Nussbaum, C.

2012-04-01

The characteristics of opalinus clay have been studied in the last years for its capacity to retain radionuclide transport as a low permeable rock. This formation presents thereby suitable properties for hosting repository sites of radioactive waste. The Mont Terri underground rock laboratory (Switzerland) has been excavated in opalinus clay layer in order to develop experiences improving the knowledge on the physico-chemical properties of the rock. The study of electrical properties furnishes information on the rock structure, its anisotropy and the changes of these properties with time (Nicollin et al., 2010 ; Thovert et al., 2011). Here the three dimensional reconstruction of the electrical resistivity aims at monitoring the temporal evolution of the excavation damaged zone. Three rings of electrodes have been set-up around the gallery and voltage is measured between two electrodes while a current is injected between two others (Gibert et al., 2006). Measurements have been achieved from July 2004 until April 2008 before, during and after the excavation of the gallery 04. In this study we develop a computational approach to reconstruct three dimensional images of the resistivity in the vicinity of the electrodes. A finite element model is used to represent the complex geometry of the gallery. The measurements inferred from a given resistivity distribution are estimated using the software EIDORS (Adler and Lionheart, 2006), this constitutes the forward problem. The reconstruction of the media resistivity is then implemented by fitting the estimated to the measured data, via the resolution of an inverse problem. The parameters of this inverse problem are defined by mapping the forward problem elements into a coarser mesh. This allows to reduce drastically the number of unknowns and so increases the robustness of the inversion. The inversion is executed with the conjugate gradient method regularised by an analysis of the Jacobian singular values. The results show an

Post-excavation analysis of a revised hydraulic model of the Room 209 fracture, URL, Manitoba, Canada

International Nuclear Information System (INIS)

Winberg, A.; Tin Chan; Griffiths, P.; Nakka, B.

1989-10-01

An excavation response test was conducted in the Room 209 on the 240 m level of the AECL Underground Research Laboratory. Model predictions prior to excavation were made of the geomechanical response of the rock mass and the hydraulic response of an intercepted fracture. The model results were compared with excavation response data collected in a comprehensive instrument array. The work performed has addressed discrepancies between calculated and in-situ measured hydraulic response as part of a post-test analysis. Already existing hydraulic conceptual models of the fracture were revised and any available information was included in the new model. The model reproduced the pre-excavation hydraulic head distribution and hydraulic test results in terms of normalized flow rate within 5% and 75%, respectively. It was also found that the model reproduced the results of cross-hole hydraulic interference tests at least from a qualitative standpoint. The next stage of the modelling addressed the response of the model to a simulation of the excavated pilot tunnel. The preliminary results suggested the presence of a skin of different permeability in a thin zone around the periphery of the tunnel. By altering the permeability in the floor and along the walls and roof of the periphery, a better correspondence between calculated and measured drawdown was obtained. The same also applied for measured groundwater inflow in quantity, though not for the actual distribution on inflow. As probable causes for the interpreted positive skin in the crown and wall, temporary partial unsaturation and propulsion of debris into the fracture were suggested. The negative skin in the floor was interpreted as an effect of the dense and high energy charges used in the excavation process. (authors)

Numerical calculation of hydrodynamic characteristics of tidal currents for submarine excavation engineering in coastal area

Directory of Open Access Journals (Sweden)

Jian-hua Li

2016-04-01

Full Text Available In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a small-scale model, with a high resolution in the vertical direction, was used to simulate the tidal current around a submarine excavation project. The finite volume method was used to solve Navier-Stokes equations and the Reynolds stress transport equation, and the entire process of the tidal current was simulated with unstructured meshes, generated in the irregular shape area, and structured meshes, generated in other water areas. The meshes near the bottom and free surface were densified with a minimum layer thickness of 0.05 m. The volume of fluid method was used to track the free surface, the volume fraction of cells on the upstream boundary was obtained from the volume fraction of adjacent cells, and that on the downstream boundary was determined by the water level process. The numerical results agree with the observed data, and some conclusions can be drawn: after the foundation trench excavation, the flow velocity decreases quite a bit through the foundation trench, with reverse flow occurring on the lee slope in the foundation trench; the swirling flow impedes inflow, leading to the occurrence of dammed water above the foundation trench; the turbulent motion is stronger during ebbing than in other tidal stages, the range with the maximum value of turbulent viscosity, occurring on the south side of the foundation trench at maximum ebbing, is greater than those in other tidal stages in a tidal cycle, and the maximum value of Reynolds shear stress occurs on the south side of the foundation trench at maximum ebbing in a tidal cycle. The numerical calculation method shows a strong performance in simulation of the hydrodynamic characteristics of tidal currents in the foundation trench, providing a basis for submarine engineering construction in coastal areas.

Integrating stochastic age-structured population dynamics into complex fisheries economic models for management evaluations: the North Sea saithe fishery as a case study

NARCIS (Netherlands)

Simons, S.L.; Bartelings, H.; Hamon, K.G.; Kempf, A.J.; Doring, R.; Temming, A.

2014-01-01

There is growing interest in bioeconomic models as tools for understanding pathways of fishery behaviour in order to assess the impact of alternative policies on natural resources. A model system is presented that combines stochastic age-structured population dynamics with complex fisheries

Stochastic processes in cell biology

CERN Document Server

Bressloff, Paul C

2014-01-01

This book develops the theory of continuous and discrete stochastic processes within the context of cell biology.  A wide range of biological topics are covered including normal and anomalous diffusion in complex cellular environments, stochastic ion channels and excitable systems, stochastic calcium signaling, molecular motors, intracellular transport, signal transduction, bacterial chemotaxis, robustness in gene networks, genetic switches and oscillators, cell polarization, polymerization, cellular length control, and branching processes. The book also provides a pedagogical introduction to the theory of stochastic process – Fokker Planck equations, stochastic differential equations, master equations and jump Markov processes, diffusion approximations and the system size expansion, first passage time problems, stochastic hybrid systems, reaction-diffusion equations, exclusion processes, WKB methods, martingales and branching processes, stochastic calculus, and numerical methods.   This text is primarily...

Aspects if stochastic models for short-term hydropower scheduling and bidding

Energy Technology Data Exchange (ETDEWEB)

Belsnes, Michael Martin [Sintef Energy, Trondheim (Norway); Follestad, Turid [Sintef Energy, Trondheim (Norway); Wolfgang, Ove [Sintef Energy, Trondheim (Norway); Fosso, Olav B. [Dep. of electric power engineering NTNU, Trondheim (Norway)

2012-07-01

This report discusses challenges met when turning from deterministic to stochastic decision support models for short-term hydropower scheduling and bidding. The report describes characteristics of the short-term scheduling and bidding problem, different market and bidding strategies, and how a stochastic optimization model can be formulated. A review of approaches for stochastic short-term modelling and stochastic modelling for the input variables inflow and market prices is given. The report discusses methods for approximating the predictive distribution of uncertain variables by scenario trees. Benefits of using a stochastic over a deterministic model are illustrated by a case study, where increased profit is obtained to a varying degree depending on the reservoir filling and price structure. Finally, an approach for assessing the effect of using a size restricted scenario tree to approximate the predictive distribution for stochastic input variables is described. The report is a summary of the findings of Work package 1 of the research project #Left Double Quotation Mark#Optimal short-term scheduling of wind and hydro resources#Right Double Quotation Mark#. The project aims at developing a prototype for an operational stochastic short-term scheduling model. Based on the investigations summarized in the report, it is concluded that using a deterministic equivalent formulation of the stochastic optimization problem is convenient and sufficient for obtaining a working prototype. (author)

Stochastic pump effect and geometric phases in dissipative and stochastic systems

Energy Technology Data Exchange (ETDEWEB)

Sinitsyn, Nikolai [Los Alamos National Laboratory

2008-01-01

The success of Berry phases in quantum mechanics stimulated the study of similar phenomena in other areas of physics, including the theory of living cell locomotion and motion of patterns in nonlinear media. More recently, geometric phases have been applied to systems operating in a strongly stochastic environment, such as molecular motors. We discuss such geometric effects in purely classical dissipative stochastic systems and their role in the theory of the stochastic pump effect (SPE).

A Top Pilot Tunnel Preconditioning Method for the Prevention of Extremely Intense Rockbursts in Deep Tunnels Excavated by TBMs

Science.gov (United States)

Zhang, Chuanqing; Feng, Xiating; Zhou, Hui; Qiu, Shili; Wu, Wenping

2012-05-01

The headrace tunnels at the Jinping II Hydropower Station cross the Jinping Mountain with a maximum overburden depth of 2,525 m, where 80% of the strata along the tunnels consist of marble. A number of extremely intense rockbursts occurred during the excavation of the auxiliary tunnels and the drainage tunnel. In particular, a tunnel boring machine (TBM) was destroyed by an extremely intense rockburst in a 7.2-m-diameter drainage tunnel. Two of the four subsequent 12.4-m-diameter headrace tunnels will be excavated with larger size TBMs, where a high risk of extremely intense rockbursts exists. Herein, a top pilot tunnel preconditioning method is proposed to minimize this risk, in which a drilling and blasting method is first recommended for the top pilot tunnel excavation and support, and then the TBM excavation of the main tunnel is conducted. In order to evaluate the mechanical effectiveness of this method, numerical simulation analyses using the failure approaching index, energy release rate, and excess shear stress indices are carried out. Its construction feasibility is discussed as well. Moreover, a microseismic monitoring technique is used in the experimental tunnel section for the real-time monitoring of the microseismic activities of the rock mass in TBM excavation and for assessing the effect of the top pilot tunnel excavation in reducing the risk of rockbursts. This method is applied to two tunnel sections prone to extremely intense rockbursts and leads to a reduction in the risk of rockbursts in TBM excavation.

Logs of Paleoseismic Excavations Across the Central Range Fault, Trinidad

Science.gov (United States)

Crosby, Christopher J.; Prentice, Carol S.; Weber, John; Ragona, Daniel

2009-01-01

This publication makes available maps and trench logs associated with studies of the Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. Our studies were conducted in 2001 and 2002. We mapped geomorphic features indicative of active faulting along the right-lateral, Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. We excavated trenches at two sites, the Samlalsingh and Tabaquite sites. At the Samlalsingh site, sediments deposited after the most recent fault movement bury the fault, and the exact location of the fault was unknown until we exposed it in our excavations. At this site, we excavated a total of eleven trenches, six of which exposed the fault. The trenches exposed fluvial sediments deposited over a strath terrace developed on Miocene bedrock units. We cleaned the walls of the excavations, gridded the walls with either 1 m X 1 m or 1 m X 0.5 m nail and string grid, and logged the walls in detail at a scale of 1:20. Additionally, we described the different sedimentary units in the field, incorporating these descriptions into our trench logs. We mapped the locations of the trenches using a tape and compass. Our field logs were scanned, and unit contacts were traced in Adobe Illustrator. The final drafted logs of all the trenches are presented here, along with photographs showing important relations among faults and Holocene sedimentary deposits. Logs of south walls were reversed in Illustrator, so that all logs are drafted with the view direction to the north. We collected samples of various materials exposed in the trench walls, including charcoal samples for radiocarbon dating from both faulted and unfaulted deposits. The locations of all samples collected are shown on the logs. The ages of seventeen of the charcoal samples submitted for radiocarbon analysis at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, Ariz., are given in Table 1. Samples found in

Preliminary results of excavations at Lincoln Cave, Sterkfontein, South Africa

CSIR Research Space (South Africa)

Reynolds, SC

2003-05-01

Full Text Available , sandwiched between two flowstone layers which could be dated using uranium series methods. The excavation furthermore yielded good indications that a portion of an older breccia has been eroded and that fauna and artefacts from this older, reworked breccia...

Stochastic Generalized Method of Moments

KAUST Repository

Yin, Guosheng; Ma, Yanyuan; Liang, Faming; Yuan, Ying

2011-01-01

The generalized method of moments (GMM) is a very popular estimation and inference procedure based on moment conditions. When likelihood-based methods are difficult to implement, one can often derive various moment conditions and construct the GMM objective function. However, minimization of the objective function in the GMM may be challenging, especially over a large parameter space. Due to the special structure of the GMM, we propose a new sampling-based algorithm, the stochastic GMM sampler, which replaces the multivariate minimization problem by a series of conditional sampling procedures. We develop the theoretical properties of the proposed iterative Monte Carlo method, and demonstrate its superior performance over other GMM estimation procedures in simulation studies. As an illustration, we apply the stochastic GMM sampler to a Medfly life longevity study. Supplemental materials for the article are available online. © 2011 American Statistical Association.

Stochastic Generalized Method of Moments

KAUST Repository

Yin, Guosheng

2011-08-16

The generalized method of moments (GMM) is a very popular estimation and inference procedure based on moment conditions. When likelihood-based methods are difficult to implement, one can often derive various moment conditions and construct the GMM objective function. However, minimization of the objective function in the GMM may be challenging, especially over a large parameter space. Due to the special structure of the GMM, we propose a new sampling-based algorithm, the stochastic GMM sampler, which replaces the multivariate minimization problem by a series of conditional sampling procedures. We develop the theoretical properties of the proposed iterative Monte Carlo method, and demonstrate its superior performance over other GMM estimation procedures in simulation studies. As an illustration, we apply the stochastic GMM sampler to a Medfly life longevity study. Supplemental materials for the article are available online. © 2011 American Statistical Association.

Numerical Simulation of Blast Vibration and Crack Forming Effect of Rock-Anchored Beam Excavation in Deep Underground Caverns

Directory of Open Access Journals (Sweden)

XinPing Li

2017-01-01

Full Text Available Aiming at surrounding rock damage induced by dynamic disturbance from blasting excavation of rock-anchored beam in rock mass at moderate or far distance in underground cavern, numerical model of different linear charging density and crustal stress in underground cavern is established by adopting dynamic finite element software based on borehole layout, charging, and rock parameter of the actual situation of a certain hydropower station. Through comparison in vibration velocity, contour surface of rock mass excavation, and the crushing extent of excavated rock mass between calculation result and field monitoring, optimum linear charging density of blast hole is determined. Studies are also conducted on rock mass vibration in moderate or far distance to blasting source, the damage of surrounding rock in near-field to blasting source, and crushing degree of excavated rock mass under various in situ stress conditions. Results indicate that, within certain range of in situ stress, the blasting vibration is independent of in situ stress, while when in situ stress is increasing above certain value, the blasting vibration velocity will be increasing and the damage of surrounding rock and the crushing degree of excavated rock mass will be decreasing.

Investment timing under hybrid stochastic and local volatility

International Nuclear Information System (INIS)

Kim, Jeong-Hoon; Lee, Min-Ku; Sohn, So Young

2014-01-01

Highlights: • The effects of hybrid stochastic volatility on real option prices are studied. • The stochastic volatility consists of a fast mean-reverting component and a CEV type one. • A fast mean-reverting factor lowers real option prices and investment thresholds. • The increase of elasticity raises real option prices and investment thresholds. • The effects of the addition of a slowly varying factor depend upon the project value. - Abstract: We consider an investment timing problem under a real option model where the instantaneous volatility of the project value is given by a combination of a hidden stochastic process and the project value itself. The stochastic volatility part is given by a function of a fast mean-reverting process as well as a slowly varying process and the local volatility part is a power (the elasticity parameter) of the project value itself. The elasticity parameter controls directly the correlation between the project value and the volatility. Knowing that the project value represents the market price of a real asset in many applications and the value of the elasticity parameter depends on the asset, the elasticity parameter should be treated with caution for investment decision problems. Based on the hybrid structure of volatility, we investigate the simultaneous impact of the elasticity and the stochastic volatility on the real option value as well as the investment threshold

Development of a teleoperated backhoe for buried waste excavation

International Nuclear Information System (INIS)

Burks, B.L.; Killough, S.M.; Thompson, D.H.

1992-01-01

For nearly five decades the United States (US) Department of Energy (DOE) and its predecessor agencies have engaged in broad-based research and development activities as well as nuclear weapons component production. As a by-product of these activities, large quantities of waste materials have been granted. One of the most common approaches used for solid waste storage was to bury waste containers in pits and trenches. With the current emphasis on environmental restoration, DOE now plans to either retrieve much of the legacy of buried waste or stabilize the waste in place via in situ vitrification or other means. Because of the variety of materials that have been buried over the years, the hazards of retrieval are significant if performed using conventional manned operations. The potential hazards, in addition to radiation exposure, include pyrophorics, toxic chemicals, and explosives. Although manifests exist for much of the buried waste, these records are often incomplete compared to today's requirements. Because of the potential hazards and uncertainty about waste contents and container integrity, it is highly desirable to excavate these wastes using remotely operated equipment. In this paper the authors describe the development of a teleoperated military tractor called the Small Emplacement Excavator (SEE). Development of the SEE is being funded jointly by both DOE and the US Army. The DOE sponsor is the Office of Technology Development (OTD) Robotics Program. The US Army sponsor is the Program Manager for Ammunition Logistics, Picatinny Arsenal. The primary interest for DOE is in the application to remote excavation of buried waste, while the primary emphasis for the US Army is in the remote retrieval of unexploded ordnance. Technical requirements for these two tasks are very similar and, therefore, justify a joint development project. 1 ref

Asymptotic problems for stochastic partial differential equations

Science.gov (United States)

Salins, Michael

Stochastic partial differential equations (SPDEs) can be used to model systems in a wide variety of fields including physics, chemistry, and engineering. The main SPDEs of interest in this dissertation are the semilinear stochastic wave equations which model the movement of a material with constant mass density that is exposed to both determinstic and random forcing. Cerrai and Freidlin have shown that on fixed time intervals, as the mass density of the material approaches zero, the solutions of the stochastic wave equation converge uniformly to the solutions of a stochastic heat equation, in probability. This is called the Smoluchowski-Kramers approximation. In Chapter 2, we investigate some of the multi-scale behaviors that these wave equations exhibit. In particular, we show that the Freidlin-Wentzell exit place and exit time asymptotics for the stochastic wave equation in the small noise regime can be approximated by the exit place and exit time asymptotics for the stochastic heat equation. We prove that the exit time and exit place asymptotics are characterized by quantities called quasipotentials and we prove that the quasipotentials converge. We then investigate the special case where the equation has a gradient structure and show that we can explicitly solve for the quasipotentials, and that the quasipotentials for the heat equation and wave equation are equal. In Chapter 3, we study the Smoluchowski-Kramers approximation in the case where the material is electrically charged and exposed to a magnetic field. Interestingly, if the system is frictionless, then the Smoluchowski-Kramers approximation does not hold. We prove that the Smoluchowski-Kramers approximation is valid for systems exposed to both a magnetic field and friction. Notably, we prove that the solutions to the second-order equations converge to the solutions of the first-order equation in an Lp sense. This strengthens previous results where convergence was proved in probability.

Underground excavation methods for a high-level waste repository

International Nuclear Information System (INIS)

Peshel, J.; Gupta, D.; Nataraja, M.

1990-01-01

This paper reports on rock excavation methods for a High-Level Waste repository that should be selected to limit the potential for creating preferential pathways for groundwater to travel to the waste packages or for radionuclides to migrate to the accessible environment. The use of water and other foreign substances should be controlled so that the repository performance is not compromised. The excavated openings should remain stable so that operations can be carried out safely and the retrievability option maintained. As per the current conceptual designs presented by the Department of Energy, the exploratory shaft facility becomes a part of the repository if the Yucca Mountain site is found suitable for repository development. Therefore, the methods of constructing the underground openings should be compatible with the performance requirements for the repository. Also, the degree of damage to the rock surrounding the openings and the extent of the damage zone should not preclude adequate site characterization. The ESf construction and operation should be compatible with the site data gathering activities, such as geological, thermomechanical, hydrological and geochemical testing

Integration of stochastic generation in power systems

NARCIS (Netherlands)

Papaefthymiou, G.; Schavemaker, P.H.; Sluis, van der L.; Kling, W.L.; Kurowicka, D.; Cooke, R.M.

2006-01-01

Stochastic generation, i.e., electrical power production by an uncontrolled primary energy source, is expected to play an important role in future power systems. A new power system structure is created due to the large-scale implementation of this small-scale, distributed, non-dispatchable

Relic excavated in western India is probably of Georgian Queen Ketevan.

Science.gov (United States)

Rai, Niraj; Taher, Nizamuddin; Singh, Manvendra; Chaubey, Gyaneshwer; Jha, Aditya Nath; Singh, Lalji; Thangaraj, Kumarasamy

2014-01-01

History has well documented the execution of Queen Ketevan of Georgia by the Persian Emperor of modern day Iran. Based on historical records, in 1624 two Augustinian friars unearthed the queen's remains and one of them brought the relic to the St. Augustine convent in Goa, India. We carried out ancient DNA analysis on the human bone remains excavated from the St. Augustine convent by sequencing and genotyping of the mitochondrial DNA. The investigations of the remains revealed a unique mtDNA haplogroup U1b, which is absent in India, but present in Georgia and surrounding regions. Since our genetic analysis corroborates archaeological and literary evidence, it is likely that the excavated bone belongs to Queen Ketevan of Georgia. Copyright © 2013 Elsevier B.V. All rights reserved.

Probabilistic Forecasts of Solar Irradiance by Stochastic Differential Equations

DEFF Research Database (Denmark)

Iversen, Jan Emil Banning; Morales González, Juan Miguel; Møller, Jan Kloppenborg

2014-01-01

approach allows for characterizing both the interdependence structure of prediction errors of short-term solar irradiance and their predictive distribution. Three different stochastic differential equation models are first fitted to a training data set and subsequently evaluated on a one-year test set...... included in probabilistic forecasts may be paramount for decision makers to efficiently make use of this uncertain and variable generation. In this paper, a stochastic differential equation framework for modeling the uncertainty associated with the solar irradiance point forecast is proposed. This modeling...

Sequential stochastic optimization

CERN Document Server

Cairoli, Renzo

1996-01-01

Sequential Stochastic Optimization provides mathematicians and applied researchers with a well-developed framework in which stochastic optimization problems can be formulated and solved. Offering much material that is either new or has never before appeared in book form, it lucidly presents a unified theory of optimal stopping and optimal sequential control of stochastic processes. This book has been carefully organized so that little prior knowledge of the subject is assumed; its only prerequisites are a standard graduate course in probability theory and some familiarity with discrete-paramet

Response spectrum analysis of a stochastic seismic model

International Nuclear Information System (INIS)

Kimura, Koji; Sakata, Masaru; Takemoto, Shinichiro.

1990-01-01

The stochastic response spectrum approach is presented for predicting the dynamic behavior of structures to earthquake excitation expressed by a random process, one of whose sample functions can be regarded as a recorded strong-motion earthquake accelerogram. The approach consists of modeling recorded ground motion by a random process and the root-mean-square response (rms) analysis of a single-degree-of-freedom system by using the moment equations method. The stochastic response spectrum is obtained as a plot of the maximum rms response versus the natural period of the system and is compared with the conventional response spectrum. (author)

Singular stochastic differential equations

CERN Document Server

Cherny, Alexander S

2005-01-01

The authors introduce, in this research monograph on stochastic differential equations, a class of points termed isolated singular points. Stochastic differential equations possessing such points (called singular stochastic differential equations here) arise often in theory and in applications. However, known conditions for the existence and uniqueness of a solution typically fail for such equations. The book concentrates on the study of the existence, the uniqueness, and, what is most important, on the qualitative behaviour of solutions of singular stochastic differential equations. This is done by providing a qualitative classification of isolated singular points, into 48 possible types.

Modelling of excavation depth and fractures in rock caused by tool indentation

International Nuclear Information System (INIS)

Kou Shaoquan; Tan Xiangchun; Lindqvist, P.A.

1997-10-01

The hydraulic regime after excavation in the near-field rock around deposition holes and deposition tunnels in a spent nuclear fuel repository is of concern for prediction of the saturation process of bentonite buffer and tunnel backfill. The hydraulic condition of main interest in this context is a result of the fracture network that is caused by the excavation. Modelling of the excavation disturbed zone in hard rocks caused by mechanical excavation has been carried out in the Division of Mining Engineering since 1993. This report contains an overview of the work conducted. The mechanical excavation is reasonably simplified as an indentation process of the interaction between rigid indenters and rocks. A large number of experiments have been carried out in the laboratory, and the results used for identifying crushed zones and fracture systems in rock under indentation are presented based on these experiments. The indentation causes crushing and damage of the rock and results in a crushed zone and a cracked zone. The indenter penetrates the rock with a certain depth when the force is over a threshold value relevant to the rock and tool. Outside the cracked zone there are basically three systems of cracks: median cracks, radial cracks, and side cracks. Fully developed radial cracks on each side of the indented area can connect with each other and join with median crack. This forms the so-called radial/median crack system. The influence of the mechanical properties of the rock is discussed based on our conceptual model, and the main factors governing the indentation event are summarised. The cracked zone is dealt with by an analytical fracture model. The side crack is simulated by applying the boundary element method coupled with fracture mechanics. Functional relationships are established relating either the indentation depth or the length of radial/median cracks to the various quantities characterising the physical event, namely the shape and the size of the

Modelling of excavation depth and fractures in rock caused by tool indentation

Energy Technology Data Exchange (ETDEWEB)

Kou Shaoquan; Tan Xiangchun; Lindqvist, P.A. [Luleaa Univ. of Technology (Sweden)

1997-10-01

The hydraulic regime after excavation in the near-field rock around deposition holes and deposition tunnels in a spent nuclear fuel repository is of concern for prediction of the saturation process of bentonite buffer and tunnel backfill. The hydraulic condition of main interest in this context is a result of the fracture network that is caused by the excavation. Modelling of the excavation disturbed zone in hard rocks caused by mechanical excavation has been carried out in the Division of Mining Engineering since 1993. This report contains an overview of the work conducted. The mechanical excavation is reasonably simplified as an indentation process of the interaction between rigid indenters and rocks. A large number of experiments have been carried out in the laboratory, and the results used for identifying crushed zones and fracture systems in rock under indentation are presented based on these experiments. The indentation causes crushing and damage of the rock and results in a crushed zone and a cracked zone. The indenter penetrates the rock with a certain depth when the force is over a threshold value relevant to the rock and tool. Outside the cracked zone there are basically three systems of cracks: median cracks, radial cracks, and side cracks. Fully developed radial cracks on each side of the indented area can connect with each other and join with median crack. This forms the so-called radial/median crack system. The influence of the mechanical properties of the rock is discussed based on our conceptual model, and the main factors governing the indentation event are summarised. The cracked zone is dealt with by an analytical fracture model. The side crack is simulated by applying the boundary element method coupled with fracture mechanics. Functional relationships are established relating either the indentation depth or the length of radial/median cracks to the various quantities characterising the physical event, namely the shape and the size of the

Evaluation of excavation experience: Pierre shale. Final report

International Nuclear Information System (INIS)

Abel, J.F. Jr.; Gentry, D.W.

1975-01-01

Pierre shale and its stratigraphic equivalents represent a potentially favorable geologic environment for underground storage of hazardous waste products. These rock formations cover great areal and vertical extents, and represent some of the least permeable rock formations within the continental United States. There are, however, several engineering problems associated with constructing underground openings in Pierre shale. This formation is relatively weak and tends to deteriorate rather rapidly if not protected from the mine environment. It will be necessary to place all underground openings below the surficially weathered upper 50 to 70 feet of Pierre shale which contains groundwater moving on fracture permeability. The optimum site for disposal of hazardous waste in Pierre shale, or its stratigraphic equivalents, would be a seismically stable platform bounded on all sides by faults. The optimum size of individual openings would be the minimum necessary for access, storage, and retrieval of waste components. Underground excavations in Pierre shale must be made with care, must be of limited dimensions, must be widely spaced, must be protected from prolonged contact with the mine environment, must be supported immediately after excavation, and must be sited to avoid areas of faulting and(or) intense jointing. Underground openings constructed with boring machines and supported with wet shotcrete are recommended

Parametric Optimization and Prediction Tool for Excavation and Prospecting Tasks, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Honeybee Robotics therefore proposed to develop a software tool for facilitating prospecting and excavation system trades in support of selecting an optimal...

Influence of Turbulent Atmosphere on Polarization Properties of Stochastic Electromagnetic Pulsed Beams

International Nuclear Information System (INIS)

Ding Chao-Liang; Zhao Zhi-Guo; Li Xiao-Feng; Pan Liu-Zhan; Yuan Xiao

2011-01-01

Using the coherence theory of non-stationary fields and the characterization of stochastic electromagnetic pulsed beams, the analytical expression for the spectral degree of polarization of stochastic electromagnetic Gaussian Schell-model pulsed (GSMP) beams in turbulent atmosphere is derived and is used to study the polarization properties of stochastic electromagnetic GSMP beams propagating through turbulent atmosphere. The results of numerical calculation are given to illustrate the dependence of spectral degree of polarization on the pulse frequency, refraction index structure constant and spatial correlation length. It is shown that, compared with free-space case, in turbulent atmosphere propagation there are two positions at which the on-axis spectral degree of polarization P is equal to zero. The position change depends on the pulse frequency, refraction index structure constant and spatial correlation length. (fundamental areas of phenomenology(including applications))

Collective, stochastic and nonequilibrium behavior of highly excited hadronic matter

Energy Technology Data Exchange (ETDEWEB)

Carruthers, P [Los Alamos National Lab., NM (USA). Theoretical Div.

1984-04-23

We discuss selected problems concerning the dynamics and stochastic behavior of highly excited matter, particularly the QCD plasma. For the latter we consider the equation of state, kinetics, quasiparticles, flow properties and possible chaos and turbulence. The promise of phase space distribution functions for covariant transport and kinetic theory is stressed. The possibility and implications of a stochastic bag are spelled out. A simplified space-time model of hadronic collisions is pursued, with applications to A-A collisions and other matters. The domain wall between hadronic and plasma phase is of potential importance: its thickness and relation to surface tension is noticed. Finally, we review the recently developed stochastic cell model of multiparticle distributions and KNO scaling. This topic leads to the notion that fractional dimensions are involved in a rather general dynamical context. We speculate that various scaling phenomena are independent of the full dynamical structure, depending only on a general stochastic framework having to do with simple maps and strange attractors. 42 refs.

Fourier analysis and stochastic processes

CERN Document Server

Brémaud, Pierre

2014-01-01

This work is unique as it provides a uniform treatment of the Fourier theories of functions (Fourier transforms and series, z-transforms), finite measures (characteristic functions, convergence in distribution), and stochastic processes (including arma series and point processes). It emphasises the links between these three themes. The chapter on the Fourier theory of point processes and signals structured by point processes is a novel addition to the literature on Fourier analysis of stochastic processes. It also connects the theory with recent lines of research such as biological spike signals and ultrawide-band communications. Although the treatment is mathematically rigorous, the convivial style makes the book accessible to a large audience. In particular, it will be interesting to anyone working in electrical engineering and communications, biology (point process signals) and econometrics (arma models). A careful review of the prerequisites (integration and probability theory in the appendix, Hilbert spa...

Potential in stochastic differential equations: novel construction

International Nuclear Information System (INIS)

Ao, P

2004-01-01

There is a whole range of emergent phenomena in a complex network such as robustness, adaptiveness, multiple-equilibrium, hysteresis, oscillation and feedback. Those non-equilibrium behaviours can often be described by a set of stochastic differential equations. One persistent important question is the existence of a potential function. Here we demonstrate that a dynamical structure built into stochastic differential equation allows us to construct such a global optimization potential function. We present an explicit construction procedure to obtain the potential and relevant quantities. In the procedure no reference to the Fokker-Planck equation is needed. The availability of the potential suggests that powerful statistical mechanics tools can be used in nonequilibrium situations. (letter to the editor)

A study of feasibility, design and cost of excavations for underground siting of nuclear power plants

International Nuclear Information System (INIS)

1976-02-01

A study conducted for the State Power Board on underground siting of nuclear power plants is presented. The report is divided into two chapters, both concerning the technical aspects of large underground openings. The first chapter gives a brief general survey of the problems involved, and the second outlines the technical aspects of a PWR project at a specific site. Details are given in 8 appendices and arrangement drawings. The project differs from conventional hydroelectric excavation schemes mainly in the fact that the spherical reactor containment requires a vault of 60m free span, and the turbine hall a cylindrical vault of 45m span, both of which exceed any span hitherto built for similar purposes. This requires a comparatively wide extrapolation of tested and available experience in underground excavations for permanent civil use. To what extent and under what circumstances such extrapolation is tenable must be tested in practice, preferably in a specially controlled prototype test. However the study indicates that conventional nuclear power plants can be sited underground when the topography and rock conditions are suitable. A 1000-2000 MW conventional plant adapted for underground siting will require large span caverns, tunnels and shafts, totalling about 1.0 mill. cubic metres of underground excavation. In addition access and cooling water tunnels, depending on the location, will require 0.2-0.5 mill. cubic metres of tunnel excavations. The excavations and support work can be completed within a construction time of about 2 1/2 years at an estimated total cost of 215 mill. Norwegian kroner (1975 value). (JIW)

A stochastic approach to anelastic creep

International Nuclear Information System (INIS)

Venkataraman, G.

1976-01-01

Anelastic creep or the time-dependent yielding or a material subjected to external stresses has been found to be of great importantance in technology in the recent years, particularly in engineering structures including nuclear reactors wherein structural members may be under stress. The physics aspects underlying this phenomenon is dealt with in detail. The basics of time-dependent elasticity, constitutive relation, network models, constitutive equation in the frequency domain and its mearurements, and stochastic approach to creep are discussed. (K.B.)

Predetermining acceptable noise limits of EXAFS spectra in the limit of stochastic noise

International Nuclear Information System (INIS)

Hu, Yung-Jin; Booth, Corwin H

2009-01-01

The effect of stochastic noise on Extended X-ray Absorption Fine Structure (EXAFS) data measurement, analysis, and fitting is discussed. Stochastic noise reduces the ability to uniquely fit a calculated model to measured EXAFS data. Such noise can be reduced by common methods that increase the signal-to-noise ratio; however, these methods are not always practical. Therefore, predetermined, quantitative knowledge of the level of acceptable stochastic noise when fitting for a particular model system is essential in maximizing the chances of a successful EXAFS experiment and minimizing wasted beamtime. This paper outlines a method to estimate, through simulation, the acceptable level of stochastic noise in EXAFS spectra that still allows a successful test of a proposed model compound.

Endoscopic excavation for gastric heterotopic pancreas: an analysis of 42 cases from a tertiary center.

Science.gov (United States)

Zhang, Yu; Huang, Qin; Zhu, Lin-hong; Zhou, Xian-bin; Ye, Li-ping; Mao, Xin-li

2014-09-01

Because of the difficulty associated with making an accurate diagnosis of gastric heterotopic pancreas (HP) before surgery, surgical resection is usually performed in suspected cases. However, this is an invasive procedure and prone to certain surgical complications. This study was designed to evaluate the feasibility of endoscopic excavation for gastric HP, as well as the value of endoscopic ultrasonography (EUS) in diagnosing gastric HP. Between January 2007 and January 2013, 42 consecutive patients with gastric HP were enrolled in this retrospective study. Key steps: (1) Injection of a solution (100 ml saline + 2 ml indigo carmine + 1 ml epinephrine) into the submucosal layer after making several dots around the lesion; (2) Incision of the mucosa outside the marker dots with a needle-knife, and then circumferential excavation until complete resection of the lesion; (3) Closure of the artificial ulcer with several clips after tumor removal. In this study, 18 cases (42.9%) were suspected as gastric HP (assessed by two experienced endoscopists before endoscopic excavation), 8 (19.0%) were suspected as gastrointestinal stromal tumors, 7 (16.7%) as gastric polyp, and the remaining 9 cases (21.4%) were still unknown. The mean procedure duration was 28.6 min. En bloc resection by endoscopic excavation was achieved in 40 cases (95.2%), and no massive bleeding, delayed bleeding, perforation, or other severe complication occurred in these patients. Among the 42 lesions, a tube echo could be detected in 11 cases by EUS. Those 11 cases were diagnosed as gastric HP by histopathology. Endoscopic excavation appears to be a safe and feasible procedure for accurate histopathologic evaluation and curative treatment in gastric HP. Use of EUS has some value in the diagnosis of gastric HP before the procedure

Probabilistic analysis of soil : Diaphragm wall friction used for value engineering of deep excavation, north/south metro Amsterdam

NARCIS (Netherlands)

Buykx, S.M.; Delfgaauw, S.; Bosch, J.W.

2009-01-01

The excavation of deep building pits often requires a check against failure by uplift of low permeability ground layers below excavation level. Whenever the weight of these soil layers is less than the pore-water pressure underneath, measures to resist buoyancy are to be considered. The measures

The extended local gauge invariance and the BRS symmetry in stochastic quantization of gauge fields

International Nuclear Information System (INIS)

Nakazawa, Naohito.

1989-05-01

We investigate the BRS invariance of the first-class constrained systems in the context of the stochastic quantization. For the first-class constrained systems, we construct the nilpotent BRS transformation and the BRS invariant stochastic effective action based on the D+1 dimensional field theoretical formulation of stochastic quantization. By eliminating the multiplier field of the gauge fixing condition and an auxiliary field, it is shown that there exists a truncated BRS transformation which satisfies the nilpotency condition. The truncated BRS invariant stochastic action is also derived. As the examples of the general formulation, we investigate the BRS invariant structure in the massless and massive Yang-Mills fields in stochastic quantization. (author)

Recent advances in ambit stochastics with a view towards tempo-spatial stochastic volatility/intermittency

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole E.; Benth, Fred Espen; Veraart, Almut

Ambit stochastics is the name for the theory and applications of ambit fields and ambit processes and constitutes a new research area in stochastics for tempo-spatial phenomena. This paper gives an overview of the main findings in ambit stochastics up to date and establishes new results on genera...

Functional Abstraction of Stochastic Hybrid Systems

NARCIS (Netherlands)

Bujorianu, L.M.; Blom, Henk A.P.; Hermanns, H.

2006-01-01

The verification problem for stochastic hybrid systems is quite difficult. One method to verify these systems is stochastic reachability analysis. Concepts of abstractions for stochastic hybrid systems are needed to ease the stochastic reachability analysis. In this paper, we set up different ways

Stochastic quantisation: theme and variation

International Nuclear Information System (INIS)

Klauder, J.R.; Kyoto Univ.

1987-01-01

The paper on stochastic quantisation is a contribution to the book commemorating the sixtieth birthday of E.S. Fradkin. Stochastic quantisation reformulates Euclidean quantum field theory in the language of Langevin equations. The generalised free field is discussed from the viewpoint of stochastic quantisation. An artificial family of highly singular model theories wherein the space-time derivatives are dropped altogether is also examined. Finally a modified form of stochastic quantisation is considered. (U.K.)

Bond and CDS Pricing via the Stochastic Recovery Black-Cox Model

Directory of Open Access Journals (Sweden)

Albert Cohen

2017-04-01

Full Text Available Building on recent work incorporating recovery risk into structural models by Cohen & Costanzino (2015, we consider the Black-Cox model with an added recovery risk driver. The recovery risk driver arises naturally in the context of imperfect information implicit in the structural framework. This leads to a two-factor structural model we call the Stochastic Recovery Black-Cox model, whereby the asset risk driver At defines the default trigger and the recovery risk driver Rt defines the amount recovered in the event of default. We then price zero-coupon bonds and credit default swaps under the Stochastic Recovery Black-Cox model. Finally, we compare our results with the classic Black-Cox model, give explicit expressions for the recovery risk premium in the Stochastic Recovery Black-Cox model, and detail how the introduction of separate but correlated risk drivers leads to a decoupling of the default and recovery risk premiums in the credit spread. We conclude this work by computing the effect of adding coupons that are paid continuously until default, and price perpetual (consol bonds in our two-factor firm value model, extending calculations in the seminal paper by Leland (1994.

Distributed Adaptive Neural Control for Stochastic Nonlinear Multiagent Systems.

Science.gov (United States)

Wang, Fang; Chen, Bing; Lin, Chong; Li, Xuehua

2016-11-14

In this paper, a consensus tracking problem of nonlinear multiagent systems is investigated under a directed communication topology. All the followers are modeled by stochastic nonlinear systems in nonstrict feedback form, where nonlinearities and stochastic disturbance terms are totally unknown. Based on the structural characteristic of neural networks (in Lemma 4), a novel distributed adaptive neural control scheme is put forward. The raised control method not only effectively handles unknown nonlinearities in nonstrict feedback systems, but also copes with the interactions among agents and coupling terms. Based on the stochastic Lyapunov functional method, it is indicated that all the signals of the closed-loop system are bounded in probability and all followers' outputs are convergent to a neighborhood of the output of leader. At last, the efficiency of the control method is testified by a numerical example.

STOCHASTIC ASSESSMENT OF NIGERIAN STOCHASTIC ...

African Journals Online (AJOL)

eobe

STOCHASTIC ASSESSMENT OF NIGERIAN WOOD FOR BRIDGE DECKS ... abandoned bridges with defects only in their decks in both rural and urban locations can be effectively .... which can be seen as the detection of rare physical.

Environmental versus demographic variability in stochastic predator–prey models

International Nuclear Information System (INIS)

Dobramysl, U; Täuber, U C

2013-01-01

In contrast to the neutral population cycles of the deterministic mean-field Lotka–Volterra rate equations, including spatial structure and stochastic noise in models for predator–prey interactions yields complex spatio-temporal structures associated with long-lived erratic population oscillations. Environmental variability in the form of quenched spatial randomness in the predation rates results in more localized activity patches. Our previous study showed that population fluctuations in rare favorable regions in turn cause a remarkable increase in the asymptotic densities of both predators and prey. Very intriguing features are found when variable interaction rates are affixed to individual particles rather than lattice sites. Stochastic dynamics with demographic variability in conjunction with inheritable predation efficiencies generate non-trivial time evolution for the predation rate distributions, yet with overall essentially neutral optimization. (paper)

Use of the 14C-PMMA and He-gas methods to characterise excavation disturbance in crystalline rock

International Nuclear Information System (INIS)

Autio, J.; Kirkkomaeki, T.; Siitari-Kauppi, M.; Timonen, J.; Laajalahti, M.; Aaltonen, T.; Maaranen, J.

1999-04-01

Characterisation of the excavation disturbance caused by boring of experimental full-scale deposition holes in the Research Tunnel at Olkiluoto was carried out successfully by using two novel methods; the 14 C-PMMA and He-gas methods, which were modified and applied for the first time in this type of study. The experience obtained implies that the techniques are feasible and can be used to study similar types of rock excavation disturbance such as that caused by boring with mini discs, a technique which will be used in the underground Hard Rock Laboratory at Aespoe during late 1998 and early 1999. Both of the measurement methods have been in continuous use and the work has included development of both the measuring and interpretation techniques. Use of the 14 C-PMMA method is suggested for studies of rock structure and the spatial distribution of porosity. The 14 C-PMMA method also provides quantitative information about nanometer-range porosity which is beyond the scope of most standard methods of microscopic investigation. The use of He-gas methods are proposed for determining the diffusion coefficient, permeability and complementary porosity of rock samples taken from the disturbed zone. (orig.)

Stochastic quantization and gravity

International Nuclear Information System (INIS)

Rumpf, H.

1984-01-01

We give a preliminary account of the application of stochastic quantization to the gravitational field. We start in Section I from Nelson's formulation of quantum mechanics as Newtonian stochastic mechanics and only then introduce the Parisi-Wu stochastic quantization scheme on which all the later discussion will be based. In Section II we present a generalization of the scheme that is applicable to fields in physical (i.e. Lorentzian) space-time and treat the free linearized gravitational field in this manner. The most remarkable result of this is the noncausal propagation of conformal gravitons. Moreover the concept of stochastic gauge-fixing is introduced and a complete discussion of all the covariant gauges is given. A special symmetry relating two classes of covariant gauges is exhibited. Finally Section III contains some preliminary remarks on full nonlinear gravity. In particular we argue that in contrast to gauge fields the stochastic gravitational field cannot be transformed to a Gaussian process. (Author)

Stochastic climate theory

NARCIS (Netherlands)

Gottwald, G.A.; Crommelin, D.T.; Franzke, C.L.E.; Franzke, C.L.E.; O'Kane, T.J.

2017-01-01

In this chapter we review stochastic modelling methods in climate science. First we provide a conceptual framework for stochastic modelling of deterministic dynamical systems based on the Mori-Zwanzig formalism. The Mori-Zwanzig equations contain a Markov term, a memory term and a term suggestive of

Bond-based linear indices of the non-stochastic and stochastic edge-adjacency matrix. 1. Theory and modeling of ChemPhys properties of organic molecules.

Science.gov (United States)

Marrero-Ponce, Yovani; Martínez-Albelo, Eugenio R; Casañola-Martín, Gerardo M; Castillo-Garit, Juan A; Echevería-Díaz, Yunaimy; Zaldivar, Vicente Romero; Tygat, Jan; Borges, José E Rodriguez; García-Domenech, Ramón; Torrens, Francisco; Pérez-Giménez, Facundo

2010-11-01

Novel bond-level molecular descriptors are proposed, based on linear maps similar to the ones defined in algebra theory. The kth edge-adjacency matrix (E(k)) denotes the matrix of bond linear indices (non-stochastic) with regard to canonical basis set. The kth stochastic edge-adjacency matrix, ES(k), is here proposed as a new molecular representation easily calculated from E(k). Then, the kth stochastic bond linear indices are calculated using ES(k) as operators of linear transformations. In both cases, the bond-type formalism is developed. The kth non-stochastic and stochastic total linear indices are calculated by adding the kth non-stochastic and stochastic bond linear indices, respectively, of all bonds in molecule. First, the new bond-based molecular descriptors (MDs) are tested for suitability, for the QSPRs, by analyzing regressions of novel indices for selected physicochemical properties of octane isomers (first round). General performance of the new descriptors in this QSPR studies is evaluated with regard to the well-known sets of 2D/3D MDs. From the analysis, we can conclude that the non-stochastic and stochastic bond-based linear indices have an overall good modeling capability proving their usefulness in QSPR studies. Later, the novel bond-level MDs are also used for the description and prediction of the boiling point of 28 alkyl-alcohols (second round), and to the modeling of the specific rate constant (log k), partition coefficient (log P), as well as the antibacterial activity of 34 derivatives of 2-furylethylenes (third round). The comparison with other approaches (edge- and vertices-based connectivity indices, total and local spectral moments, and quantum chemical descriptors as well as E-state/biomolecular encounter parameters) exposes a good behavior of our method in this QSPR studies. Finally, the approach described in this study appears to be a very promising structural invariant, useful not only for QSPR studies but also for similarity

Structural damage detection based on stochastic subspace identification and statistical pattern recognition: I. Theory

Science.gov (United States)

Ren, W. X.; Lin, Y. Q.; Fang, S. E.

2011-11-01

One of the key issues in vibration-based structural health monitoring is to extract the damage-sensitive but environment-insensitive features from sampled dynamic response measurements and to carry out the statistical analysis of these features for structural damage detection. A new damage feature is proposed in this paper by using the system matrices of the forward innovation model based on the covariance-driven stochastic subspace identification of a vibrating system. To overcome the variations of the system matrices, a non-singularity transposition matrix is introduced so that the system matrices are normalized to their standard forms. For reducing the effects of modeling errors, noise and environmental variations on measured structural responses, a statistical pattern recognition paradigm is incorporated into the proposed method. The Mahalanobis and Euclidean distance decision functions of the damage feature vector are adopted by defining a statistics-based damage index. The proposed structural damage detection method is verified against one numerical signal and two numerical beams. It is demonstrated that the proposed statistics-based damage index is sensitive to damage and shows some robustness to the noise and false estimation of the system ranks. The method is capable of locating damage of the beam structures under different types of excitations. The robustness of the proposed damage detection method to the variations in environmental temperature is further validated in a companion paper by a reinforced concrete beam tested in the laboratory and a full-scale arch bridge tested in the field.

2–stage stochastic Runge–Kutta for stochastic delay differential equations

Energy Technology Data Exchange (ETDEWEB)

Rosli, Norhayati; Jusoh Awang, Rahimah [Faculty of Industrial Science and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300, Gambang, Pahang (Malaysia); Bahar, Arifah; Yeak, S. H. [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)

2015-05-15

This paper proposes a newly developed one-step derivative-free method, that is 2-stage stochastic Runge-Kutta (SRK2) to approximate the solution of stochastic delay differential equations (SDDEs) with a constant time lag, r > 0. General formulation of stochastic Runge-Kutta for SDDEs is introduced and Stratonovich Taylor series expansion for numerical solution of SRK2 is presented. Local truncation error of SRK2 is measured by comparing the Stratonovich Taylor expansion of the exact solution with the computed solution. Numerical experiment is performed to assure the validity of the method in simulating the strong solution of SDDEs.

The evolution of competitive settlement strategies in Fijian prehistory : results of excavations and radiometric dating

International Nuclear Information System (INIS)

Field, J.S.

2003-01-01

A series of excavations were completed between June 2001 and March 2002 in the Fiji Islands. The goal of this research was to investigate the evolution of competitive settlement strategies in Fijian prehistory from an archaeological and evolutionary ecological perspective. Twelve sites were excavated and mapped in the Sigatoka Valley, located in the southwestern corner of the main island of Viti Levu. Excavations were focused on determining the chronology of fortifications in the region, and the collected samples were compared to expectations based on GIS-based analyses of land productivity and historical documents pertaining to late-period warfare. Over four hundred archaeological sites have been identified in the Sigatoka Valley, and of these roughly one-third are purely defensive in configuration, with no immediate access to water or arable land. The Waikato Archaeological Dating Fund provided four radiometric dates for three defensive sites, and one site associated with a production area. (author). 6 refs., 1 fig

Our experience with the full-profile excavation of exploratory for tunnel pipes

Directory of Open Access Journals (Sweden)

Edita Lazarová

2006-12-01

Full Text Available The economic development of Slovakia places an emphasis on increasing the quality of transport infrastructure, which requires its modernization residing in building the transport network of international level and improving its efficiency and travel speed. The development of transport in Slovakia has been passing major changes related to the economic and political processes in the country. Regarding the geographical character of the land, the tunnel excavation is an inseparable feature of the road communications modernization. Approximately thirty kilometres of highway tunnels are planned for construction in Slovakia until 2020 and road tunnels should be constructed as well. The first modern highway tunnel Branisko, the longest one (4975 m in Slovakia was put into operation in 2003 with a preceding excavation of the Branisko exploratory gallery in the course of designed tunnel pipe. The tunnelling works on the exploratory gallery of Višňové tunnel started in January 1999 and finished in the late summer of 2002 due to unfavorable geological conditions. The excavation of a final profile of the Višňové tunnel is planned for 2007. The Horelica tunnel (605 m near Čadca was finished and put into operation in 2004. The tunnels Lučivná (250 m, Bôrik (999 m and Sitina (1440 m are in construction at present.

New Design Concept for an Excavator Arms by Using Composite Material

Science.gov (United States)

Solazzi, L.; Assi, A.; Ceresoli, F.

2018-06-01

The purpose of the present paper is to lightweight design an excavator arms, by using a different materials and in particular composite material. Specifically, the research is based on the study of a commercial excavator, by determining its geometry and analyzing the load conditions to which it is exposed. These are determined in relation to either the load diagram of the machine or the possible utilities of the excavator, such as the rotation of the machine. The materials used and implemented in the different analytical and numerical elaborations are classic construction steel S 355 (UNI EN 10025-3), high-resistance steel S 890 (UNI EN 10025-6), aluminum Al 6063 T6 (UNI EN 573-3) and the composite material made by carbon fiber and epoxy resin. The adopted constraints for the design of new arms with different materials, non-conventional for these applications, are numerous. The new solutions must present a safety factor either with respect to the yield tensile strength or to the critical load of buckling greater than or equal to the one determined for the excavator in its original geometrical conformation. Another criterion, which has heavily conditioned the geometry of the arms, was given by the fact that the developed solutions must present a very similar value of the maximum displacement in the different load conditions analyzed. A new geometry for arms made by composite material was developed. It was an elliptical conic section, instead of the classic rectangular section, in order to use the filament winding technological process. As for the adoption of the composite material, we focused on the study and the design of this material as long as the interaction with the extremities (made of aluminum) which are interfaced either with the link between the arms or with the elements of the hydraulic plant which serves for the arms movement. From the results developed, it emerges that the solution developed by adopting composite materials is the one that permits the

Space-time-modulated stochastic processes

Science.gov (United States)

Giona, Massimiliano

2017-10-01

Starting from the physical problem associated with the Lorentzian transformation of a Poisson-Kac process in inertial frames, the concept of space-time-modulated stochastic processes is introduced for processes possessing finite propagation velocity. This class of stochastic processes provides a two-way coupling between the stochastic perturbation acting on a physical observable and the evolution of the physical observable itself, which in turn influences the statistical properties of the stochastic perturbation during its evolution. The definition of space-time-modulated processes requires the introduction of two functions: a nonlinear amplitude modulation, controlling the intensity of the stochastic perturbation, and a time-horizon function, which modulates its statistical properties, providing irreducible feedback between the stochastic perturbation and the physical observable influenced by it. The latter property is the peculiar fingerprint of this class of models that makes them suitable for extension to generic curved-space times. Considering Poisson-Kac processes as prototypical examples of stochastic processes possessing finite propagation velocity, the balance equations for the probability density functions associated with their space-time modulations are derived. Several examples highlighting the peculiarities of space-time-modulated processes are thoroughly analyzed.

RES: Regularized Stochastic BFGS Algorithm

Science.gov (United States)

Mokhtari, Aryan; Ribeiro, Alejandro

2014-12-01

RES, a regularized stochastic version of the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton method is proposed to solve convex optimization problems with stochastic objectives. The use of stochastic gradient descent algorithms is widespread, but the number of iterations required to approximate optimal arguments can be prohibitive in high dimensional problems. Application of second order methods, on the other hand, is impracticable because computation of objective function Hessian inverses incurs excessive computational cost. BFGS modifies gradient descent by introducing a Hessian approximation matrix computed from finite gradient differences. RES utilizes stochastic gradients in lieu of deterministic gradients for both, the determination of descent directions and the approximation of the objective function's curvature. Since stochastic gradients can be computed at manageable computational cost RES is realizable and retains the convergence rate advantages of its deterministic counterparts. Convergence results show that lower and upper bounds on the Hessian egeinvalues of the sample functions are sufficient to guarantee convergence to optimal arguments. Numerical experiments showcase reductions in convergence time relative to stochastic gradient descent algorithms and non-regularized stochastic versions of BFGS. An application of RES to the implementation of support vector machines is developed.

Excavations and chronology at the Redcliffs Flat site, Canterbury, New Zealand

International Nuclear Information System (INIS)

Jacomb, C.

2009-01-01

The Redcliffs Flat site is one of a number of early Maori archaeological sites that cluster near the mouth of the estuary of the Avon and Heathcote rivers. Although several have been the subject of archaeological investigations, the chronology and extent of the Redcliffs Flat site remain poorly understood. Recent excavations associated with the redevelopment of a suburban section allow some progress to be made on both fronts. A small excavation here yielded a surprising amount of faunal, lithic and stratigraphic information. The site is shown to have extended to close to the edge of the estuary at the time of occupation and a radiocarbon date on a fragment of moa eggshell confirms the fourteenth to early fifteenth century status of the site. The radiocarbon chronology of the sites of the wider Redcliffs area is reviewed in light of this result. (author). 41 refs., 6 figs., 3 tabs.

Elitism and Stochastic Dominance

OpenAIRE

Bazen, Stephen; Moyes, Patrick

2011-01-01

Stochastic dominance has typically been used with a special emphasis on risk and inequality reduction something captured by the concavity of the utility function in the expected utility model. We claim that the applicability of the stochastic dominance approach goes far beyond risk and inequality measurement provided suitable adpations be made. We apply in the paper the stochastic dominance approach to the measurment of elitism which may be considered the opposite of egalitarianism. While the...

Apparatus and method for large tunnel excavation in soft and incompetent rock or ground

International Nuclear Information System (INIS)

Altseimer, J.H.; Hanold, R.J.

1975-01-01

A tunneling machine is described for producing large tunnels in soft rock or wet, clayey, unconsolidated or bouldery earth by simultaneously detaching the tunnel core by thermal melting a boundary kerf into the tunnel face and forming a supporting excavation wall liner by deflecting the molten materials against the excavation walls to provide, when solidified, a continuous wall supporting liner, and detaching the tunnel face circumscribed by the kerf with powered mechanical earth detachment means and in which the heat required for melting the kerf and liner material is provided by a compact nuclear reactor. (U.S.)

Explicit calibration and simulation of stochastic fields by low-order ARMA processes

DEFF Research Database (Denmark)

Krenk, Steen

2011-01-01

A simple framework for autoregressive simulation of stochastic fields is presented. The autoregressive format leads to a simple exponential correlation structure in the time-dimension. In the case of scalar processes a more detailed correlation structure can be obtained by adding memory...... to the process via an extension to autoregressive moving average (ARMA) processes. The ARMA format incorporates a more detailed correlation structure by including previous values of the simulated process. Alternatively, a more detailed correlation structure can be obtained by including additional 'state......-space' variables in the simulation. For a scalar process this would imply an increase of the dimension of the process to be simulated. In the case of a stochastic field the correlation in the time-dimension is represented, although indirectly, in the simultaneous spatial correlation. The model with the shortest...

Development of stochastic webs in a wave-driven linear oscillator

International Nuclear Information System (INIS)

Murakami, Sadayoshi; Sato, Tetsuya; Hasegawa, Akira.

1988-01-01

We present developments of stochastic webs in a linear oscillator which is driven by a finite number (N) of external waves with frequency ω o (harmonic of the linear oscillator frequency). The expansion of the stochastic domain as functions of the number of waves and their amplitudes is studied numerically. The results with small amplitude waves compares well with the perturbation theory. When the amplitude of external waves is small a leaf structure which expands with N develops radially in the phase space. (author)

Stochastic symplectic and multi-symplectic methods for nonlinear Schrödinger equation with white noise dispersion

Energy Technology Data Exchange (ETDEWEB)

Cui, Jianbo, E-mail: jianbocui@lsec.cc.ac.cn [Institute of Computational Mathematics and Scientific/Engineering Computing, Chinese Academy of Sciences, Beijing, 100190 (China); Hong, Jialin, E-mail: hjl@lsec.cc.ac.cn [Institute of Computational Mathematics and Scientific/Engineering Computing, Chinese Academy of Sciences, Beijing, 100190 (China); Liu, Zhihui, E-mail: liuzhihui@lsec.cc.ac.cn [Institute of Computational Mathematics and Scientific/Engineering Computing, Chinese Academy of Sciences, Beijing, 100190 (China); Zhou, Weien, E-mail: weienzhou@nudt.edu.cn [College of Science, National University of Defense Technology, Changsha 410073 (China)

2017-08-01

We indicate that the nonlinear Schrödinger equation with white noise dispersion possesses stochastic symplectic and multi-symplectic structures. Based on these structures, we propose the stochastic symplectic and multi-symplectic methods, which preserve the continuous and discrete charge conservation laws, respectively. Moreover, we show that the proposed methods are convergent with temporal order one in probability. Numerical experiments are presented to verify our theoretical results.

Stochastic symplectic and multi-symplectic methods for nonlinear Schrödinger equation with white noise dispersion

International Nuclear Information System (INIS)

Cui, Jianbo; Hong, Jialin; Liu, Zhihui; Zhou, Weien

2017-01-01

We indicate that the nonlinear Schrödinger equation with white noise dispersion possesses stochastic symplectic and multi-symplectic structures. Based on these structures, we propose the stochastic symplectic and multi-symplectic methods, which preserve the continuous and discrete charge conservation laws, respectively. Moreover, we show that the proposed methods are convergent with temporal order one in probability. Numerical experiments are presented to verify our theoretical results.

Plan for the testing of radiation measurement instrumentation intended for use at an excavation site

International Nuclear Information System (INIS)

Gehrke, R.J.

1994-11-01

This plan describes performance tests to be made with ionizing radiation measurement instrumentation designed and built for in-field assay at an excavation site. One instrument measures gross gamma-ray and neutron fields and the other identifies gamma-ray emitting radionuclides and also is capable of assaying for selected hazardous materials. These instruments will be operationally tested to verify that original specifications have been met and performance tested to establish and verify that they have the potential to function as intended at an excavation site

Conditional Stochastic Processes Applied to Wave Load Predictions

DEFF Research Database (Denmark)

Jensen, Jørgen Juncher

2015-01-01

The concept of conditional stochastic processes provides a powerful tool for evaluation and estimation of wave loads on ships and offshore structures. This article first considers conditional waves with a focus on critical wave episodes. Then the inherent uncertainty in the results is illustrated...

FROM EXCAVATIONS TO WEB: A GIS FOR ARCHAEOLOGY

Directory of Open Access Journals (Sweden)

M. G. D'Urso

2017-05-01

Full Text Available The study and the protection of Cultural Heritage in recent years have undergone a revolution about the search tools and the reference disciplines. The technological approach to the problem of the collection, organization and publication of archaeological data using GIS software has completely changed the essence of the traditional methods of investigation, paving the way to the development of several application areas, up to the Cultural Resource Management. A relatively recent specific sector of development for archaeological GIS development sector is dedicated to the intra - site analyses aimed to recording, processing and display information obtained during the excavations. The case - study of the archaeological site located in the south - east of San Pietro Vetere plateau in Aquino, in the Southern Lazio, is concerned with the illustration of a procedure describing the complete digital workflow relative to an intra-site analysis of an archaeological dig. The GIS project implementation and its publication on the web, thanks to several softwares, particularly the FOSS (Free Open Source Software Quantum - GIS, are an opportunity to reflect on the strengths and the critical nature of this particular application of the GIS technology. For future developments in research it is of fundamental importance the identification of a digital protocol for processing of excavations (from the acquisition, cataloguing, up data insertion, also on account of a possible future Open Project on medieval Aquino.

Stochastic analytic regularization

International Nuclear Information System (INIS)

Alfaro, J.

1984-07-01

Stochastic regularization is reexamined, pointing out a restriction on its use due to a new type of divergence which is not present in the unregulated theory. Furthermore, we introduce a new form of stochastic regularization which permits the use of a minimal subtraction scheme to define the renormalized Green functions. (author)

On Stochastic Dependence

Science.gov (United States)

Meyer, Joerg M.

2018-01-01

The contrary of stochastic independence splits up into two cases: pairs of events being favourable or being unfavourable. Examples show that both notions have quite unexpected properties, some of them being opposite to intuition. For example, transitivity does not hold. Stochastic dependence is also useful to explain cases of Simpson's paradox.

Stochastic massless fields I: Integer spin

International Nuclear Information System (INIS)

Lim, S.C.

1981-04-01

Nelson's stochastic quantization scheme is applied to classical massless tensor potential in ''Coulomb'' gauge. The relationship between stochastic potential field in various gauges is discussed using the case of vector potential as an illustration. It is possible to identify the Euclidean tensor potential with the corresponding stochastic field in physical Minkowski space-time. Stochastic quantization of massless fields can also be carried out in terms of field strength tensors. An example of linearized stochastic gravitational field in vacuum is given. (author)

Classical and quantum stochastic models of resistive and memristive circuits

Science.gov (United States)

Gough, John E.; Zhang, Guofeng

2017-07-01

The purpose of this paper is to examine stochastic Markovian models for circuits in phase space for which the drift term is equivalent to the standard circuit equations. In particular, we include dissipative components corresponding to both a resistor and a memristor in series. We obtain a dilation of the problem which is canonical in the sense that the underlying Poisson bracket structure is preserved under the stochastic flow. We do this first of all for standard Wiener noise but also treat the problem using a new concept of symplectic noise, where the Poisson structure is extended to the noise as well as the circuit variables, and in particular where we have canonically conjugate noises. Finally, we construct a dilation which describes the quantum mechanical analogue.

Stochastic and information-thermodynamic structures of population dynamics in a fluctuating environment

Science.gov (United States)

Kobayashi, Tetsuya J.; Sughiyama, Yuki

2017-07-01

Adaptation in a fluctuating environment is a process of fueling environmental information to gain fitness. Living systems have gradually developed strategies for adaptation from random and passive diversification of the phenotype to more proactive decision making, in which environmental information is sensed and exploited more actively and effectively. Understanding the fundamental relation between fitness and information is therefore crucial to clarify the limits and universal properties of adaptation. In this work, we elucidate the underlying stochastic and information-thermodynamic structure in this process, by deriving causal fluctuation relations (FRs) of fitness and information. Combined with a duality between phenotypic and environmental dynamics, the FRs reveal the limit of fitness gain, the relation of time reversibility with the achievability of the limit, and the possibility and condition for gaining excess fitness due to environmental fluctuation. The loss of fitness due to causal constraints and the limited capacity of real organisms is shown to be the difference between time-forward and time-backward path probabilities of phenotypic and environmental dynamics. Furthermore, the FRs generalize the concept of the evolutionary stable state (ESS) for fluctuating environment by giving the probability that the optimal strategy on average can be invaded by a suboptimal one owing to rare environmental fluctuation. These results clarify the information-thermodynamic structures in adaptation and evolution.

SELANSI: a toolbox for simulation of stochastic gene regulatory networks.

Science.gov (United States)

Pájaro, Manuel; Otero-Muras, Irene; Vázquez, Carlos; Alonso, Antonio A

2018-03-01

Gene regulation is inherently stochastic. In many applications concerning Systems and Synthetic Biology such as the reverse engineering and the de novo design of genetic circuits, stochastic effects (yet potentially crucial) are often neglected due to the high computational cost of stochastic simulations. With advances in these fields there is an increasing need of tools providing accurate approximations of the stochastic dynamics of gene regulatory networks (GRNs) with reduced computational effort. This work presents SELANSI (SEmi-LAgrangian SImulation of GRNs), a software toolbox for the simulation of stochastic multidimensional gene regulatory networks. SELANSI exploits intrinsic structural properties of gene regulatory networks to accurately approximate the corresponding Chemical Master Equation with a partial integral differential equation that is solved by a semi-lagrangian method with high efficiency. Networks under consideration might involve multiple genes with self and cross regulations, in which genes can be regulated by different transcription factors. Moreover, the validity of the method is not restricted to a particular type of kinetics. The tool offers total flexibility regarding network topology, kinetics and parameterization, as well as simulation options. SELANSI runs under the MATLAB environment, and is available under GPLv3 license at https://sites.google.com/view/selansi. antonio@iim.csic.es. © The Author(s) 2017. Published by Oxford University Press.

Stochastic Geometric Models with Non-stationary Spatial Correlations in Lagrangian Fluid Flows

Science.gov (United States)

Gay-Balmaz, François; Holm, Darryl D.

2018-01-01

Inspired by spatiotemporal observations from satellites of the trajectories of objects drifting near the surface of the ocean in the National Oceanic and Atmospheric Administration's "Global Drifter Program", this paper develops data-driven stochastic models of geophysical fluid dynamics (GFD) with non-stationary spatial correlations representing the dynamical behaviour of oceanic currents. Three models are considered. Model 1 from Holm (Proc R Soc A 471:20140963, 2015) is reviewed, in which the spatial correlations are time independent. Two new models, called Model 2 and Model 3, introduce two different symmetry breaking mechanisms by which the spatial correlations may be advected by the flow. These models are derived using reduction by symmetry of stochastic variational principles, leading to stochastic Hamiltonian systems, whose momentum maps, conservation laws and Lie-Poisson bracket structures are used in developing the new stochastic Hamiltonian models of GFD.

Stochastic Geometric Models with Non-stationary Spatial Correlations in Lagrangian Fluid Flows

Science.gov (United States)

Gay-Balmaz, François; Holm, Darryl D.

2018-06-01

Inspired by spatiotemporal observations from satellites of the trajectories of objects drifting near the surface of the ocean in the National Oceanic and Atmospheric Administration's "Global Drifter Program", this paper develops data-driven stochastic models of geophysical fluid dynamics (GFD) with non-stationary spatial correlations representing the dynamical behaviour of oceanic currents. Three models are considered. Model 1 from Holm (Proc R Soc A 471:20140963, 2015) is reviewed, in which the spatial correlations are time independent. Two new models, called Model 2 and Model 3, introduce two different symmetry breaking mechanisms by which the spatial correlations may be advected by the flow. These models are derived using reduction by symmetry of stochastic variational principles, leading to stochastic Hamiltonian systems, whose momentum maps, conservation laws and Lie-Poisson bracket structures are used in developing the new stochastic Hamiltonian models of GFD.

Investigation of the impact of excavation (reinforced) on the seismic ...

African Journals Online (AJOL)

Every year, as a result of earthquake, abundant losses may be created as result of roof motion and sliding and rupture. Under normal conditions, the ground and soils forming the ground tolerate and transfer the existing stresses and any kind of action like excavation and release of trench and applying dynamic load could ...

Stochastic processes inference theory

CERN Document Server

Rao, Malempati M

2014-01-01

This is the revised and enlarged 2nd edition of the authors’ original text, which was intended to be a modest complement to Grenander's fundamental memoir on stochastic processes and related inference theory. The present volume gives a substantial account of regression analysis, both for stochastic processes and measures, and includes recent material on Ridge regression with some unexpected applications, for example in econometrics. The first three chapters can be used for a quarter or semester graduate course on inference on stochastic processes. The remaining chapters provide more advanced material on stochastic analysis suitable for graduate seminars and discussions, leading to dissertation or research work. In general, the book will be of interest to researchers in probability theory, mathematical statistics and electrical and information theory.

Path to Stochastic Stability: Comparative Analysis of Stochastic Learning Dynamics in Games

KAUST Repository

Jaleel, Hassan

2018-04-08

Stochastic stability is a popular solution concept for stochastic learning dynamics in games. However, a critical limitation of this solution concept is its inability to distinguish between different learning rules that lead to the same steady-state behavior. We address this limitation for the first time and develop a framework for the comparative analysis of stochastic learning dynamics with different update rules but same steady-state behavior. We present the framework in the context of two learning dynamics: Log-Linear Learning (LLL) and Metropolis Learning (ML). Although both of these dynamics have the same stochastically stable states, LLL and ML correspond to different behavioral models for decision making. Moreover, we demonstrate through an example setup of sensor coverage game that for each of these dynamics, the paths to stochastically stable states exhibit distinctive behaviors. Therefore, we propose multiple criteria to analyze and quantify the differences in the short and medium run behavior of stochastic learning dynamics. We derive and compare upper bounds on the expected hitting time to the set of Nash equilibria for both LLL and ML. For the medium to long-run behavior, we identify a set of tools from the theory of perturbed Markov chains that result in a hierarchical decomposition of the state space into collections of states called cycles. We compare LLL and ML based on the proposed criteria and develop invaluable insights into the comparative behavior of the two dynamics.

Quantum stochastics

CERN Document Server

Chang, Mou-Hsiung

2015-01-01

The classical probability theory initiated by Kolmogorov and its quantum counterpart, pioneered by von Neumann, were created at about the same time in the 1930s, but development of the quantum theory has trailed far behind. Although highly appealing, the quantum theory has a steep learning curve, requiring tools from both probability and analysis and a facility for combining the two viewpoints. This book is a systematic, self-contained account of the core of quantum probability and quantum stochastic processes for graduate students and researchers. The only assumed background is knowledge of the basic theory of Hilbert spaces, bounded linear operators, and classical Markov processes. From there, the book introduces additional tools from analysis, and then builds the quantum probability framework needed to support applications to quantum control and quantum information and communication. These include quantum noise, quantum stochastic calculus, stochastic quantum differential equations, quantum Markov semigrou...

Nambu mechanics for stochastic magnetization dynamics

Energy Technology Data Exchange (ETDEWEB)

Thibaudeau, Pascal, E-mail: pascal.thibaudeau@cea.fr [CEA DAM/Le Ripault, BP 16, F-37260 Monts (France); Nussle, Thomas, E-mail: thomas.nussle@cea.fr [CEA DAM/Le Ripault, BP 16, F-37260 Monts (France); CNRS-Laboratoire de Mathématiques et Physique Théorique (UMR 7350), Fédération de Recherche “Denis Poisson” (FR2964), Département de Physique, Université de Tours, Parc de Grandmont, F-37200 Tours (France); Nicolis, Stam, E-mail: stam.nicolis@lmpt.univ-tours.fr [CNRS-Laboratoire de Mathématiques et Physique Théorique (UMR 7350), Fédération de Recherche “Denis Poisson” (FR2964), Département de Physique, Université de Tours, Parc de Grandmont, F-37200 Tours (France)

2017-06-15

Highlights: • The LLG equation can be formulated in the framework of dissipative Nambu mechanics. • A master equation is derived for the spin dynamics for additive/multiplicative noises. • The derived stochastic equations are compared to moment equations obtained by closures. - Abstract: The Landau–Lifshitz–Gilbert (LLG) equation describes the dynamics of a damped magnetization vector that can be understood as a generalization of Larmor spin precession. The LLG equation cannot be deduced from the Hamiltonian framework, by introducing a coupling to a usual bath, but requires the introduction of additional constraints. It is shown that these constraints can be formulated elegantly and consistently in the framework of dissipative Nambu mechanics. This has many consequences for both the variational principle and for topological aspects of hidden symmetries that control conserved quantities. We particularly study how the damping terms of dissipative Nambu mechanics affect the consistent interaction of magnetic systems with stochastic reservoirs and derive a master equation for the magnetization. The proposals are supported by numerical studies using symplectic integrators that preserve the topological structure of Nambu equations. These results are compared to computations performed by direct sampling of the stochastic equations and by using closure assumptions for the moment equations, deduced from the master equation.

Stochastic analysis for Poisson point processes Malliavin calculus, Wiener-Itô chaos expansions and stochastic geometry

CERN Document Server

Peccati, Giovanni

2016-01-01

Stochastic geometry is the branch of mathematics that studies geometric structures associated with random configurations, such as random graphs, tilings and mosaics. Due to its close ties with stereology and spatial statistics, the results in this area are relevant for a large number of important applications, e.g. to the mathematical modeling and statistical analysis of telecommunication networks, geostatistics and image analysis. In recent years – due mainly to the impetus of the authors and their collaborators – a powerful connection has been established between stochastic geometry and the Malliavin calculus of variations, which is a collection of probabilistic techniques based on the properties of infinite-dimensional differential operators. This has led in particular to the discovery of a large number of new quantitative limit theorems for high-dimensional geometric objects. This unique book presents an organic collection of authoritative surveys written by the principal actors in this rapidly evolvi...

Stochastic cooling

International Nuclear Information System (INIS)

Bisognano, J.; Leemann, C.

1982-03-01

Stochastic cooling is the damping of betatron oscillations and momentum spread of a particle beam by a feedback system. In its simplest form, a pickup electrode detects the transverse positions or momenta of particles in a storage ring, and the signal produced is amplified and applied downstream to a kicker. The time delay of the cable and electronics is designed to match the transit time of particles along the arc of the storage ring between the pickup and kicker so that an individual particle receives the amplified version of the signal it produced at the pick-up. If there were only a single particle in the ring, it is obvious that betatron oscillations and momentum offset could be damped. However, in addition to its own signal, a particle receives signals from other beam particles. In the limit of an infinite number of particles, no damping could be achieved; we have Liouville's theorem with constant density of the phase space fluid. For a finite, albeit large number of particles, there remains a residue of the single particle damping which is of practical use in accumulating low phase space density beams of particles such as antiprotons. It was the realization of this fact that led to the invention of stochastic cooling by S. van der Meer in 1968. Since its conception, stochastic cooling has been the subject of much theoretical and experimental work. The earliest experiments were performed at the ISR in 1974, with the subsequent ICE studies firmly establishing the stochastic cooling technique. This work directly led to the design and construction of the Antiproton Accumulator at CERN and the beginnings of p anti p colliding beam physics at the SPS. Experiments in stochastic cooling have been performed at Fermilab in collaboration with LBL, and a design is currently under development for a anti p accumulator for the Tevatron

Stochastic optimal control, forward-backward stochastic differential equations and the Schroedinger equation

Energy Technology Data Exchange (ETDEWEB)

Paul, Wolfgang; Koeppe, Jeanette [Institut fuer Physik, Martin Luther Universitaet, 06099 Halle (Germany); Grecksch, Wilfried [Institut fuer Mathematik, Martin Luther Universitaet, 06099 Halle (Germany)

2016-07-01

The standard approach to solve a non-relativistic quantum problem is through analytical or numerical solution of the Schroedinger equation. We show a way to go around it. This way is based on the derivation of the Schroedinger equation from conservative diffusion processes and the establishment of (several) stochastic variational principles leading to the Schroedinger equation under the assumption of a kinematics described by Nelson's diffusion processes. Mathematically, the variational principle can be considered as a stochastic optimal control problem linked to the forward-backward stochastic differential equations of Nelson's stochastic mechanics. The Hamilton-Jacobi-Bellmann equation of this control problem is the Schroedinger equation. We present the mathematical background and how to turn it into a numerical scheme for analyzing a quantum system without using the Schroedinger equation and exemplify the approach for a simple 1d problem.

Supplement analysis for paleontological excavation at the National Ignition Facility at Lawrence Livermore National Laboratory

International Nuclear Information System (INIS)

1997-01-01

On December 15, 1997, contractor workers supporting the National Ignition Facility (NIF) construction uncovered bones suspected to be of paleontological importance. The NIF workers were excavating a utility trench near the southwest corner of the NIF footprint area, located at the northeast corner of the Lawrence Livermore National Laboratory (LLNL) Livermore Site, and were excavating at a depth of approximately 30 feet. Upon the discovery of bone fragments, the excavation in the immediate vicinity was halted and the LLNL archaeologist was notified. The archaeologist determined that there was no indication of cultural resources. Mark Goodwin, Senior Curator for the University of California Museum of Paleontology at the University of California, Berkeley, was then contacted. Mr. Goodwin visited the site on December 16th and confirmed that the bones consisted of a section of the skull, a portion of the mandible, several teeth, upper palate, and possibly the vertebrae of a mammoth, genus Mammuthus columbi. This supplement analysis evaluates the potential for adverse impacts of excavating skeletal remains, an activity that was only generally assessed by the NIF Project-Specific Analysis in the Final Programmatic Environmental impact Statement for Stockpile Stewardship and Management (SS and M PEIS) published in September 1996 (DOE/EIS-0236) and its Record of Decision published on December 19, 1996. This supplement analysis has been prepared pursuant to the DOE regulations implementing the National Environmental Policy Act (10 CFR 1021.314)

Coarse-graining and hybrid methods for efficient simulation of stochastic multi-scale models of tumour growth

International Nuclear Information System (INIS)

Cruz, Roberto de la; Guerrero, Pilar; Calvo, Juan; Alarcón, Tomás

2017-01-01

The development of hybrid methodologies is of current interest in both multi-scale modelling and stochastic reaction–diffusion systems regarding their applications to biology. We formulate a hybrid method for stochastic multi-scale models of cells populations that extends the remit of existing hybrid methods for reaction–diffusion systems. Such method is developed for a stochastic multi-scale model of tumour growth, i.e. population-dynamical models which account for the effects of intrinsic noise affecting both the number of cells and the intracellular dynamics. In order to formulate this method, we develop a coarse-grained approximation for both the full stochastic model and its mean-field limit. Such approximation involves averaging out the age-structure (which accounts for the multi-scale nature of the model) by assuming that the age distribution of the population settles onto equilibrium very fast. We then couple the coarse-grained mean-field model to the full stochastic multi-scale model. By doing so, within the mean-field region, we are neglecting noise in both cell numbers (population) and their birth rates (structure). This implies that, in addition to the issues that arise in stochastic-reaction diffusion systems, we need to account for the age-structure of the population when attempting to couple both descriptions. We exploit our coarse-graining model so that, within the mean-field region, the age-distribution is in equilibrium and we know its explicit form. This allows us to couple both domains consistently, as upon transference of cells from the mean-field to the stochastic region, we sample the equilibrium age distribution. Furthermore, our method allows us to investigate the effects of intracellular noise, i.e. fluctuations of the birth rate, on collective properties such as travelling wave velocity. We show that the combination of population and birth-rate noise gives rise to large fluctuations of the birth rate in the region at the leading edge

Stochastic Analysis : A Series of Lectures

CERN Document Server

Dozzi, Marco; Flandoli, Franco; Russo, Francesco

2015-01-01

This book presents in thirteen refereed survey articles an overview of modern activity in stochastic analysis, written by leading international experts. The topics addressed include stochastic fluid dynamics and regularization by noise of deterministic dynamical systems; stochastic partial differential equations driven by Gaussian or Lévy noise, including the relationship between parabolic equations and particle systems, and wave equations in a geometric framework; Malliavin calculus and applications to stochastic numerics; stochastic integration in Banach spaces; porous media-type equations; stochastic deformations of classical mechanics and Feynman integrals and stochastic differential equations with reflection. The articles are based on short courses given at the Centre Interfacultaire Bernoulli of the Ecole Polytechnique Fédérale de Lausanne, Switzerland, from January to June 2012. They offer a valuable resource not only for specialists, but also for other researchers and Ph.D. students in the fields o...

Stochastic Analysis with Financial Applications

CERN Document Server

Kohatsu-Higa, Arturo; Sheu, Shuenn-Jyi

2011-01-01

Stochastic analysis has a variety of applications to biological systems as well as physical and engineering problems, and its applications to finance and insurance have bloomed exponentially in recent times. The goal of this book is to present a broad overview of the range of applications of stochastic analysis and some of its recent theoretical developments. This includes numerical simulation, error analysis, parameter estimation, as well as control and robustness properties for stochastic equations. This book also covers the areas of backward stochastic differential equations via the (non-li

Evolution of mud-capped dredge pits following excavation: sediment trapping and slope instability

Science.gov (United States)

Obelcz, J.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; O'Connor, M. C.; Wang, J.

2016-02-01

Many fluvial channels incised the Northern Gulf of Mexico inner continental shelf during the late Quaternary. Mud-capped dredge pits (MCDPs), which are generally elongate and deep (8-10 m) excavations, target sandy fluvial channel deposits for coastal restoration projects. The morphological evolution of dredge excavations in noncohesive sandy substrate is well studied, but MCDPs have up to a several-meter-thick veneer of Holocene shelf mud overlying sandy channel deposits. This stratigraphy is hypothesized to result in more complex post-dredge morphology than pit walls simply slumping to the angle of repose shortly after excavation. Numerical modeling of MCDP post-dredge response conducted prior to excavation indicates pit walls may retrogressively fail, which is accounted for in pit design by assigning no-dredge setback buffers from pipelines or cultural and environmental resources. To validate model results and test effectiveness of setback buffers, a geophysical survey of the Sandy Point MCDP (20 km west of the Mississippi River Delta in 10m deep water), where 1.7 million m3 of sandy sediment was excavated in 2012, was conducted May 2015. A total of 84 line-km of high-resolution chirp subbottom and a 27 km2 grid of swath bathymetry and sidescan sonar were collected. The data indicate the dredge pit walls are differentially slumping, with the western pit wall in a more active state of failure than the eastern wall. The western failures morphologically resemble features observed along the muddy Mississippi River Delta Front at water depths of 20-100 m, including bowl-shaped collapse failures and retrogressive stair-stepped slumps; these failures may play a key role in evaluating the distance of setback buffer zone to pipelines. These features indicate the cohesive mud overlying the sandy infill has a prominent role in pit wall stability. A 0.5-1 m thick acoustically transparent package overlies the entire pit floor (interpreted as a possible fluid mud layer

Analytic stochastic regularization and gauge theories

International Nuclear Information System (INIS)

Abdalla, E.; Gomes, M.; Lima-Santos, A.

1987-04-01

We prove that analytic stochatic regularization braks gauge invariance. This is done by an explicit one loop calculation of the two three and four point vertex functions of the gluon field in scalar chromodynamics, which turns out not to be geuge invariant. We analyse the counter term structure, Langevin equations and the construction of composite operators in the general framework of stochastic quantization. (author) [pt

Hydrogeologic characterization and evolution of the 'excavation damaged zone' by statistical analyses of pressure signals: application to galleries excavated at the clay-stone sites of Mont Terri (Ga98) and Tournemire (Ga03)

International Nuclear Information System (INIS)

Fatmi, H.; Ababou, R.; Matray, J.M.; Joly, C.

2010-01-01

Document available in extended abstract form only. This paper presents methods of statistical analysis and interpretation of hydrogeological signals in clayey formations, e.g., pore water pressure and atmospheric pressure. The purpose of these analyses is to characterize the hydraulic behaviour of this type of formation in the case of a deep repository of Mid- Level/High-Level and Long-lived radioactive wastes, and to study the evolution of the geologic formation and its EDZ (Excavation Damaged Zone) during the excavation of galleries. We focus on galleries Ga98 and Ga03 in the sites of Mont Terri (Jura, Switzerland) and Tournemire (France, Aveyron), through data collected in the BPP- 1 and PH2 boreholes, respectively. The Mont Terri site, crossing the Aalenian Opalinus clay-stone, is an underground laboratory managed by an international consortium, namely the Mont Terri project (Switzerland). The Tournemire site, crossing the Toarcian clay-stone, is an Underground Research facility managed by IRSN (France). We have analysed pore water and atmospheric pressure signals at these sites, sometimes in correlation with other data. The methods of analysis are based on the theory of stationary random signals (correlation functions, Fourier spectra, transfer functions, envelopes), and on multi-resolution wavelet analysis (adapted to nonstationary and evolutionary signals). These methods are also combined with filtering techniques, and they can be used for single signals as well as pairs of signals (cross-analyses). The objective of this work is to exploit pressure measurements in selected boreholes from the two compacted clay sites, in order to: - evaluate phenomena affecting the measurements (earth tides, barometric pressures..); - estimate hydraulic properties (specific storage..) of the clay-stones prior to excavation works and compare them with those estimated by pulse or slug tests on shorter time scales; - analyze the effects of drift excavation on pore pressures

Assessment of technologies for hazardous waste site remediation: Non-treatment technologies and pilot scale facility implementation -- excavation -- storage technology -- safety analysis and review statement

International Nuclear Information System (INIS)

Johnson, H.R.; Overbey, W.K. Jr.; Koperna, G.J. Jr.

1994-02-01

The purpose of this study is to assess the state-of-the-art of excavation technology as related to environmental remediation applications. A further purpose is to determine which of the excavation technologies reviewed could be used by the US Corp of Engineers in remediating contaminated soil to be excavated in the near future for construction of a new Lock and Dam at Winfield, WV. The study is designed to identify excavation methodologies and equipment which can be used at any environmental remediation site but more specifically at the Winfield site on the Kanawha River in Putnam County, West Virginia. A technical approach was determined whereby a functional analysis was prepared to determine the functions to be conducted during the excavation phase of the remediation operations. A number of excavation technologies were identified from the literature. A set of screening criteria was developed that would examine the utility and ranking of the technologies with respect to the operations that needed to be conducted at the Winfield site. These criteria were performance, reliability, implementability, environmental safety, public health, and legal and regulatory compliance. The Loose Bulk excavation technology was ranked as the best technology applicable to the Winfield site. The literature was also examined to determine the success of various methods of controlling fugitive dust. Depending upon any changes in the results of chemical analyses, or prior remediation of the VOCs from the vadose zone, consideration should be given to testing a new ''Pneumatic Excavator'' which removes the VOCs liberated during the excavation process as they outgas from the soil. This equipment however would not be needed on locations with low levels of VOC emissions

The 2010-2011 excavation season at Al Zubarah, north-west Qatar

DEFF Research Database (Denmark)

Richter, Tobias; al-Naimi, Faisal; Yeomans, Lisa

2012-01-01

This paper briefly summarizes the results of the 2010–2011 archaeological fieldwork at the late eighteenth–twentieth-century abandoned city of al-Zubarah in north-west Qatar. The excavations in five areas inside the town, covering courtyard houses, a suq, a palatial compound, and a midden...

Short-term Probabilistic Forecasting of Wind Speed Using Stochastic Differential Equations

DEFF Research Database (Denmark)

Iversen, Jan Emil Banning; Morales González, Juan Miguel; Møller, Jan Kloppenborg

2016-01-01

and uncertain nature. In this paper, we propose a modeling framework for wind speed that is based on stochastic differential equations. We show that stochastic differential equations allow us to naturally capture the time dependence structure of wind speed prediction errors (from 1 up to 24 hours ahead) and......It is widely accepted today that probabilistic forecasts of wind power production constitute valuable information for both wind power producers and power system operators to economically exploit this form of renewable energy, while mitigating the potential adverse effects related to its variable......, most importantly, to derive point and quantile forecasts, predictive distributions, and time-path trajectories (also referred to as scenarios or ensemble forecasts), all by one single stochastic differential equation model characterized by a few parameters....

Stochastic three-wave interaction in flaring solar loops

Science.gov (United States)

Vlahos, L.; Sharma, R. R.; Papadopoulos, K.

1983-01-01

A model is proposed for the dynamic structure of high-frequency microwave bursts. The dynamic component is attributed to beams of precipitating electrons which generate electrostatic waves in the upper hybrid branch. Coherent upconversion of the electrostatic waves to electromagnetic waves produces an intrinsically stochastic emission component which is superposed on the gyrosynchrotron continuum generated by stably trapped electron fluxes. The role of the density and temperature of the ambient plasma in the wave growth and the transition of the three wave upconversion to stochastic, despite the stationarity of the energy source, are discussed in detail. The model appears to reproduce the observational features for reasonable parameters of the solar flare plasma.

Stochastic three-wave interaction in flaring solar loops

International Nuclear Information System (INIS)

Vlahos, L.; Sharma, R.R.; Papadopoulos, K.

1983-01-01

We propose a model for the dynamic structure of high-frequency microwave bursts. The dynamic component is attributed to beams of precipitating electrons which generate electrostatic waves in the upper hybrid branch. Coherent upconversion of the electrostatic waves to electromagnetic waves produces an intrinsically stochastic emission component which is superposed on the gyrosynchrotron continuum generated by stably trapped electron fluxes. The role of the density and temperature of the ambient plasma in the wave growth and the transition of the three wave upconversion to stochastic, despite the stationarity of the energy source are discussed in detail. The model appears to reproduce the observational features for reasonable parameters of the solar flare plasma

Excavating silences and tensions of agency|passivity in science education reform

Science.gov (United States)

Rivera Maulucci, Maria S.

2010-12-01

I reflect on studies by Rodriguez and Carlone, Haun-Frank, and Kimmel to emphasize the ways in which they excavate silences in the science education literature related to linguistic and cultural diversity and situating the problem of reform in teachers rather than contextual factors, such as traditional schooling discourses and forces that serve to marginalize science. I propose that the current push for top-down reform and accountability diminishes opportunities for receptivity, learning with and from students in order to transform teachers' practices and promote equity in science education. I discuss tensions of agency and passivity in science education reform and argue that attention to authentic caring constitutes another silence in the science education literature. I conclude that the current policy context positions teachers and science education researchers as tempered radicals struggling against opp(reg)ressive reforms and that there is a need for more studies to excavate these and other silences.

Stochastic Reachability Analysis of Hybrid Systems

CERN Document Server

Bujorianu, Luminita Manuela

2012-01-01

Stochastic reachability analysis (SRA) is a method of analyzing the behavior of control systems which mix discrete and continuous dynamics. For probabilistic discrete systems it has been shown to be a practical verification method but for stochastic hybrid systems it can be rather more. As a verification technique SRA can assess the safety and performance of, for example, autonomous systems, robot and aircraft path planning and multi-agent coordination but it can also be used for the adaptive control of such systems. Stochastic Reachability Analysis of Hybrid Systems is a self-contained and accessible introduction to this novel topic in the analysis and development of stochastic hybrid systems. Beginning with the relevant aspects of Markov models and introducing stochastic hybrid systems, the book then moves on to coverage of reachability analysis for stochastic hybrid systems. Following this build up, the core of the text first formally defines the concept of reachability in the stochastic framework and then...

Endoscopic en bloc resection of an exophytic gastrointestinal stromal tumor with suction excavation technique

Science.gov (United States)

Choi, Hyuk Soon; Chun, Hoon Jai; Kim, Kyoung-Oh; Kim, Eun Sun; Keum, Bora; Jeen, Yoon-Tae; Lee, Hong Sik; Kim, Chang Duck

2016-01-01

Here, we report the first successful endoscopic resection of an exophytic gastrointestinal stromal tumor (GIST) using a novel perforation-free suction excavation technique. A 49-year-old woman presented for further management of a gastric subepithelial tumor on the lesser curvature of the lower body, originally detected via routine upper gastrointestinal endoscopy. Abdominal computed tomography and endoscopic ultrasound showed a 4-cm extraluminally protruding mass originating from the muscularis propria layer. The patient firmly refused surgical resection owing to potential cardiac problems, and informed consent was obtained for endoscopic removal. Careful dissection and suction of the tumor was repeated until successful extraction was achieved without serosal injury. We named this procedure the suction excavation technique. The tumor’s dimensions were 3.5 cm × 2.8 cm × 2.5 cm. The tumor was positive for C-KIT and CD34 by immunohistochemical staining. The mitotic count was 6/50 high-power fields. The patient was followed for 5 years without tumor recurrence. This case demonstrated the use of endoscopic resection of an exophytic GIST using the suction excavation technique as a potential therapy without surgical resection. PMID:27340363

Field observations and failure analysis of an excavation damaged zone in the Horonobe Underground Research Laboratory

International Nuclear Information System (INIS)

Aoyagi, Kazuhei; Ishii, Eiichi; Ishida, Tsuyoshi

2017-01-01

In the construction of a deep underground facility, the hydromechanical properties of the rock mass around an underground opening are changed significantly due to stress redistribution. This zone is called an excavation damaged zone (EDZ). In high-level radioactive waste disposal, EDZs can provide a shortcut for the escape of radionuclides to the surface environment. Therefore, it is important to develop a method for predicting the detailed characteristics of EDZs. For prediction of the EDZ in the Horonobe Underground Research Laboratory of Japan, we conducted borehole televiewer surveys, rock core analyses, and repeated hydraulic conductivity measurements. We observed that niche excavation resulted in the formation of extension fractures within 0.2 to 1.0 m into the niche wall, i.e., the extent of the EDZ is within 0.2 to 1.0 m into the niche wall. These results are largely consistent with the results of a finite element analysis implemented with the failure criteria considering failure mode. The hydraulic conductivity in the EDZ was increased by 3 to 5 orders of magnitude compared with the outer zone. The hydraulic conductivity in and around the EDZ has not changed significantly in the two years following excavation of the niche. These results show that short-term unloading due to excavation of the niche created a highly permeable EDZ. (author)

Stochastic processes, slaves and supersymmetry

International Nuclear Information System (INIS)

Drummond, I T; Horgan, R R

2012-01-01

We extend the work of Tănase-Nicola and Kurchan on the structure of diffusion processes and the associated supersymmetry algebra by examining the responses of a simple statistical system to external disturbances of various kinds. We consider both the stochastic differential equations (SDEs) for the process and the associated diffusion equation. The influence of the disturbances can be understood by augmenting the original SDE with an equation for slave variables. The evolution of the slave variables describes the behaviour of line elements carried along in the stochastic flow. These line elements, together with the associated surface and volume elements constructed from them, provide the basis of the supersymmetry properties of the theory. For ease of visualization, and in order to emphasize a helpful electromagnetic analogy, we work in three dimensions. The results are all generalizable to higher dimensions and can be specialized to one and two dimensions. The electromagnetic analogy is a useful starting point for calculating asymptotic results at low temperature that can be compared with direct numerical evaluations. We also examine the problems that arise in a direct numerical simulation of the stochastic equation together with the slave equations. We pay special attention to the dependence of the slave variable statistics on temperature. We identify in specific models the critical temperature below which the slave variable distribution ceases to have a variance and consider the effect on estimates of susceptibilities. (paper)

Homogenization of the stochastic Navier–Stokes equation with a stochastic slip boundary condition

KAUST Repository

Bessaih, Hakima

2015-11-02

The two-dimensional Navier–Stokes equation in a perforated domain with a dynamical slip boundary condition is considered. We assume that the dynamic is driven by a stochastic perturbation on the interior of the domain and another stochastic perturbation on the boundaries of the holes. We consider a scaling (ᵋ for the viscosity and 1 for the density) that will lead to a time-dependent limit problem. However, the noncritical scaling (ᵋ, β > 1) is considered in front of the nonlinear term. The homogenized system in the limit is obtained as a Darcy’s law with memory with two permeabilities and an extra term that is due to the stochastic perturbation on the boundary of the holes. The nonhomogeneity on the boundary contains a stochastic part that yields in the limit an additional term in the Darcy’s law. We use the two-scale convergence method after extending the solution with 0 inside the holes to pass to the limit. By Itô stochastic calculus, we get uniform estimates on the solution in appropriate spaces. Due to the stochastic integral, the pressure that appears in the variational formulation does not have enough regularity in time. This fact made us rely only on the variational formulation for the passage to the limit on the solution. We obtain a variational formulation for the limit that is solution of a Stokes system with two pressures. This two-scale limit gives rise to three cell problems, two of them give the permeabilities while the third one gives an extra term in the Darcy’s law due to the stochastic perturbation on the boundary of the holes.

Stochastic Estimation via Polynomial Chaos

Science.gov (United States)

2015-10-01

AFRL-RW-EG-TR-2015-108 Stochastic Estimation via Polynomial Chaos Douglas V. Nance Air Force Research...COVERED (From - To) 20-04-2015 – 07-08-2015 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Stochastic Estimation via Polynomial Chaos ...This expository report discusses fundamental aspects of the polynomial chaos method for representing the properties of second order stochastic

Exploration and excavation of shipwrecks in Goa and adjoining waters 2004-2005

Digital Repository Service at National Institute of Oceanography (India)

Anon

As a part of the Institutional Project, 'Application of geological and geophysical methods in marine archaeology and underwater explorations' (STS 0004), exploration and excavation of shipwrecks have been carried out from Nov 24-Dec 02, 2005 for 06...

Exploration and excavation of shipwrecks in Goa and adjoining waters 2005-2006

Digital Repository Service at National Institute of Oceanography (India)

As a part of the institutional project, 'Application of Geological and Geophysical methods in Marine Archaeology and Underwater Explorations, (OLP 0008)', exploration and excavation of shipwrecks have been carried out from 23 Jan 2006 to 21 Feb 2006...

Electrical tomography monitoring of the EDZ during the excavation of the gallery Ga08 in the Mont Terri URL

International Nuclear Information System (INIS)

Nicollin, Florence; Gibert, Dominique; Lesparre, Nolwenn; Nussbaum, Christophe

2010-01-01

, subsets of 32 electrodes were selected on 18 areas of 1.2 m high by 0.9 m wide, to measure the electrical resistivity in 12 directions of the face plane. In each of the 2 groups of boreholes, the electrical resistivity is measured in 8 directions of a plane perpendicular to the face. Using simulated annealing, each data set was inverted independently to recover the full tensor of resistivity, given in term of its principal values. While the minimum value and the intermediate value are rather constant (9 ± 2 W.m and 27 ± 7 W.m respectively), the maximum value is significantly different in two domains separated by a tectonic fracture (200 ± 37 W.m in the upper domain and 74 ± 15 W.m in the lower domain). The direction of this maximum value is almost constant and deviates of less than 10 deg. from the direction normal to the bedding plane. Consequently, the directions of intermediate and minimum values are contained in the bedding plane, with the direction of minimum resistivity also tangent to the curved shaped face. So, we may conclude that the geo-electrical structure of the EDZ results here from complex interaction between inherited tectonic features, stratigraphic properties and stress perturbation produced by the excavation of the gallery. During one month corresponding to the excavation of the last meters of the gallery Ga08, including a temporary stop (18 days) of excavation at 8 m from the Ga04 face (end of the long boreholes), electrical tomography was done continuously using the lines of electrodes installed in the 4 long boreholes. Daily, one Wenner profile was performed in each borehole, and numerous cross-hole measurements were performed between the 6 possible pairs of boreholes spaced 1 to 2 meters. These cross-hole measurements are dominated by a sharp increase of electrical resistivity at the time of the stop of excavation, visible at any distances in the boreholes but with higher amplitudes at the Ga08 side. In the time series of Wenner profiles, the

Remarks on stochastic acceleration

International Nuclear Information System (INIS)

Graeff, P.

1982-12-01

Stochastic acceleration and turbulent diffusion are strong turbulence problems since no expansion parameter exists. Hence the problem of finding rigorous results is of major interest both for checking approximations and for reference models. Since we have found a way of constructing such models in the turbulent diffusion case the question of the extension to stochastic acceleration now arises. The paper offers some possibilities illustrated by the case of 'stochastic free fall' which may be particularly interesting in the context of linear response theory. (orig.)

Assessment of geomechanical properties, maximum depth and excavation damaged zone aspects - Expert report

International Nuclear Information System (INIS)

Amann, F.; Löw, S.; Perras, M.

2015-11-01

This comprehensive report published by the Swiss National Nuclear Safety Inspectorate ENSI discusses the expert report published on the need for the assessment of geomechanical properties and maximum depth of repositories for high, medium and low-activity nuclear wastes. Also, aspects concerning excavation damaged zones (EDZ) are considered. These are all criteria for the selection of sites as part of Phase 2 of the Swiss waste disposal project. Four questions are examined: are NAGRA’s documented basic considerations and calculations on Opalinus Clay comprehensive enough and correct, are the calculations on maximum depth correct, are the proposed storage perimeters correct with respect to depth and will NAGRA be able to take possible excavation damaged zones (EDZ) into account? Literature and references concerning the subject are quoted

Stochastic parameterizing manifolds and non-Markovian reduced equations stochastic manifolds for nonlinear SPDEs II

CERN Document Server

Chekroun, Mickaël D; Wang, Shouhong

2015-01-01

In this second volume, a general approach is developed to provide approximate parameterizations of the "small" scales by the "large" ones for a broad class of stochastic partial differential equations (SPDEs). This is accomplished via the concept of parameterizing manifolds (PMs), which are stochastic manifolds that improve, for a given realization of the noise, in mean square error the partial knowledge of the full SPDE solution when compared to its projection onto some resolved modes. Backward-forward systems are designed to give access to such PMs in practice. The key idea consists of representing the modes with high wave numbers as a pullback limit depending on the time-history of the modes with low wave numbers. Non-Markovian stochastic reduced systems are then derived based on such a PM approach. The reduced systems take the form of stochastic differential equations involving random coefficients that convey memory effects. The theory is illustrated on a stochastic Burgers-type equation.

Stochastic spin-one massive field

International Nuclear Information System (INIS)

Lim, S.C.

1984-01-01

Stochastic quantization schemes of Nelson and Parisi and Wu are applied to a spin-one massive field. Unlike the scalar case Nelson's stochastic spin-one massive field cannot be identified with the corresponding euclidean field even if the fourth component of the euclidean coordinate is taken as equal to the real physical time. In the Parisi-Wu quantization scheme the stochastic Proca vector field has a similar property as the scalar field; which has an asymptotically stationary part and a transient part. The large equal-time limit of the expectation values of the stochastic Proca field are equal to the expectation values of the corresponding euclidean field. In the Stueckelberg formalism the Parisi-Wu scheme gives rise to a stochastic vector field which differs from the massless gauge field in that the gauge cannot be fixed by the choice of boundary condition. (orig.)

Pricing real estate index options under stochastic interest rates

Science.gov (United States)

Gong, Pu; Dai, Jun

2017-08-01

Real estate derivatives as new financial instruments are not merely risk management tools but also provide a novel way to gain exposure to real estate assets without buying or selling the physical assets. Although real estate derivatives market has exhibited a rapid development in recent years, the valuation challenge of real estate derivatives remains a great obstacle for further development in this market. In this paper, we derive a partial differential equation contingent on a real estate index in a stochastic interest rate environment and propose a modified finite difference method that adopts the non-uniform grids to solve this problem. Numerical results confirm the efficiency of the method and indicate that constant interest rate models lead to the mispricing of options and the effects of stochastic interest rates on option prices depend on whether the term structure of interest rates is rising or falling. Finally, we have investigated and compared the different effects of stochastic interest rates on European and American option prices.

Stochastic TDHF and the Boltzman-Langevin equation

International Nuclear Information System (INIS)

Suraud, E.; Reinhard, P.G.

1991-01-01

Outgoing from a time-dependent theory of correlations, we present a stochastic differential equation for the propagation of ensembles of Slater determinants, called Stochastic Time-Dependent Hartree-Fock (Stochastic TDHF). These ensembles are allowed to develop large fluctuations in the Hartree-Fock mean fields. An alternative stochastic differential equation, the Boltzmann-Langevin equation, can be derived from Stochastic TDHF by averaging over subensembles with small fluctuations

Middle Stone Age stratigraphy and excavations at Die Kelders Cave 1 (Western Cape Province, South Africa): the 1992, 1993, and 1995 field seasons.

Science.gov (United States)

Marean, C W; Goldberg, P; Avery, G; Grine, F E; Klein, R G

2000-01-01

Die Kelders Cave 1, first excavated under the direction of Franz Schweitzer in 1969-1973, was re-excavated between 1992 and 1995 by a combined team from the South African Museum, SUNY at Stony Brook, and Stanford University. These renewed excavations enlarged the artefactual and faunal samples from the inadequately sampled and less intensively excavated lower Middle Stone Age (MSA) layers, increased our understanding of the complex site formation processes within the cave, enlarged the hominid sample from the MSA deposits, and generated ESR, TL, and OSL dates for the MSA layers. Importantly, these new excavations dramatically improved our comprehension of the vertical and lateral characteristics of the MSA stratigraphy. Surface plotting of the MSA layers has led to the identification of at least two major zones of subsidence that significantly warped the layers, draping some along the eroding surface contours of major blocks of fallen limestone roof rock. A third zone of subsidence is probably present in the older excavations. Dramatic roof falls of very large limestone blocks occurred at least twice-once in the middle of Layer 4/5 where the roof blocks were only slightly weathered after collapse, and at the top of Layer 6 where the blocks weathered heavily after collapse, producing a zone of decomposed rock around the blocks. Many of the sandy strata are cut by small and localized faults and slippages. All of the strata documented by Schweitzer's excavations are present throughout the exposed area to the west of his excavated area, where many of them thicken and become more complex. Layer 6, the thickest MSA layer, becomes less diagenetically altered and compressed to the west. Copyright 2000 Academic Press.

Stochastic resonance in a stochastic bistable system with additive noises and square–wave signal

International Nuclear Information System (INIS)

Feng, Guo; Xiang-Dong, Luo; Shao-Fu, Li; Yu-Rong, Zhou

2010-01-01

This paper considers the stochastic resonance in a stochastic bistable system driven by a periodic square-wave signal and a static force as well as by additive white noise and dichotomous noise from the viewpoint of signal-to-noise ratio. It finds that the signal-to-noise ratio appears as stochastic resonance behaviour when it is plotted as a function of the noise strength of the white noise and dichotomous noise, as a function of the system parameters, or as a function of the static force. Moreover, the influence of the strength of the stochastic potential force and the correlation rate of the dichotomous noise on the signal-to-noise ratio is investigated. (general)

The Origin of the ‘Chicago Method’ Excavation Techniques: Contributions of William Nickerson and Frederick Starr

Directory of Open Access Journals (Sweden)

David Browman

2013-09-01

Full Text Available What were the origins of the ‘Chicago method’ of scientific excavation? What is it and how did it get that name? Does its origin predate its popular employment at excavations in the USA during the 1930s and 1940s, and go back to institutional competition between Frederic Ward Putnam of the Field Museum and Frederick Starr of the University of Chicago? Or was it the result of the fieldwork of avocational archaeologist and one of Putnam’s first students, William Baker Nickerson, who implemented it as the basis of his fieldwork, and proved its efficacy, for many years before he retired in 1921? Nickerson’s detailed notes on the results of his thorough stratigraphic excavation techniques, used at many archaeological sites in Iowa, Illinois, Ohio and Minnesota, were passed on to the first University of Chicago field party doing archaeological work in Illinois, that consequently became the foundations of the later ‘Chicago method’.

Stochastic quantization of Proca field

International Nuclear Information System (INIS)

Lim, S.C.

1981-03-01

We discuss the complications that arise in the application of Nelson's stochastic quantization scheme to classical Proca field. One consistent way to obtain spin-one massive stochastic field is given. It is found that the result of Guerra et al on the connection between ground state stochastic field and the corresponding Euclidean-Markov field extends to the spin-one case. (author)

Stochastic optimization methods

CERN Document Server

Marti, Kurt

2005-01-01

Optimization problems arising in practice involve random parameters. For the computation of robust optimal solutions, i.e., optimal solutions being insensitive with respect to random parameter variations, deterministic substitute problems are needed. Based on the distribution of the random data, and using decision theoretical concepts, optimization problems under stochastic uncertainty are converted into deterministic substitute problems. Due to the occurring probabilities and expectations, approximative solution techniques must be applied. Deterministic and stochastic approximation methods and their analytical properties are provided: Taylor expansion, regression and response surface methods, probability inequalities, First Order Reliability Methods, convex approximation/deterministic descent directions/efficient points, stochastic approximation methods, differentiation of probability and mean value functions. Convergence results of the resulting iterative solution procedures are given.

Acoustic wave propagation and stochastic effects in metamaterial absorbers

DEFF Research Database (Denmark)

Christensen, Johan; Willatzen, Morten

2014-01-01

We show how stochastic variations of the effective parameters of anisotropic structured metamaterials can lead to increased absorption of sound. For this, we derive an analytical model based on the Bourret approximation and illustrate the immediate connection between material disorder and attenua...

MBC model analysis for predicting the rock behavior in excavating the Mizunami Underground Research Laboratory

International Nuclear Information System (INIS)

Mori, Takayuki; Iwano, Keita; Nakajima, Makoto; Morikawa, Seiji; Tabei, Kazuto

2005-03-01

As a Phase 1 of MIU project (Mizunami Underground Research Laboratory project), through the laboratory and borehole in-situ tests, JNC Tono Geoscience Center plans to constitute the comprehensive geological model and predicts the rock behaviors in excavating the shaft and gallery. These model and results leads to be reflected by the next step research projects. So far, the Phase 1 of MIU project is coming to final stage, and the Phase 2 will start at next year in which the in-situ researches are planned through the excavation. In this study, the comprehensive geometrical model was drawn out through the Phase 1 data, and MBC model analysis was carried out to predict the rock mass behavior around the shaft and gallery. The following results are obtained. 1. With MIZ-1 borehole core, artificial joints, which are assumed to be produced by rock blasting, were formed through the Brazilian test. And through the rock shear test for these joints, these mechanical properties were obtained. 2. By examining the MIZ-1 borehole research data, Mizunami site was classified by mechanical and joint properties and the Geomechanical model were made up. 3. Through the MBC model, the shaft and gallery cases were analyzed which depend on the rock mass classification, Excavation Damaged Zone, and the direction of the galleries. These results showed that in most cases, the joint opening were little because of the rock stiffness, but by the existence of high inclined joints, the side wall of the galleries were damaged by the excavation. (author)

HOMOCLINIC TANGLE BIFURCATIONS AND EDGE STOCHASTICITY IN DIVERTED TOKAMAKS

International Nuclear Information System (INIS)

EVANS, T.E.; ROEDER, R.K.W.; CARTER, J.A.; RAPOPORT, B.I.

2003-01-01

OAK-B135 The boundary and pedestal region of a poloidally diverted tokamak is particularly susceptible to the onset of vacuum magnetic field stochasticity due to small non-axisymmetric resonant perturbations. Recent calculations of the separatrix topology in diverted tokamaks, when subjected to small magnetic perturbations, show the existence of complex invariant manifold structures known as homoclinic tangles. These structures appear above a relatively low perturbation threshold that depends on certain equilibrium shape parameters. Homoclinic tangles represent a splitting of the unperturbed separatrix into stable and unstable invariant manifolds associated with each X-point (hyperbolic point). The manifolds that make up homoclinic tangles set the boundaries that prescribe how stochastic field line trajectories are organized i.e., how field lines from the inner domain of the unperturbed separatrix mix and are transported to plasma facing surfaces such as divertor target plates and protruding baffle structures. Thus, the topology of these tangles determines which plasma facing components are most likely to interact with escaping magnetic field lines and the parallel heat and particle flux they carry

Optimal Tax Reduction by Depreciation : A Stochastic Model

NARCIS (Netherlands)

Berg, M.; De Waegenaere, A.M.B.; Wielhouwer, J.L.

1996-01-01

This paper focuses on the choice of a depreciation method, when trying to minimize the expected value of the present value of future tax payments.In a quite general model that allows for stochastic future cash- ows and a tax structure with tax brackets, we determine the optimal choice between the

Phenomenology of stochastic exponential growth

Science.gov (United States)

Pirjol, Dan; Jafarpour, Farshid; Iyer-Biswas, Srividya

2017-06-01

Stochastic exponential growth is observed in a variety of contexts, including molecular autocatalysis, nuclear fission, population growth, inflation of the universe, viral social media posts, and financial markets. Yet literature on modeling the phenomenology of these stochastic dynamics has predominantly focused on one model, geometric Brownian motion (GBM), which can be described as the solution of a Langevin equation with linear drift and linear multiplicative noise. Using recent experimental results on stochastic exponential growth of individual bacterial cell sizes, we motivate the need for a more general class of phenomenological models of stochastic exponential growth, which are consistent with the observation that the mean-rescaled distributions are approximately stationary at long times. We show that this behavior is not consistent with GBM, instead it is consistent with power-law multiplicative noise with positive fractional powers. Therefore, we consider this general class of phenomenological models for stochastic exponential growth, provide analytical solutions, and identify the important dimensionless combination of model parameters, which determines the shape of the mean-rescaled distribution. We also provide a prescription for robustly inferring model parameters from experimentally observed stochastic growth trajectories.

Methods to ensure the quality of excavated soil material from geogenically metalliferous sites

Science.gov (United States)

Liebhard, Peter; Sager, Manfred

2017-04-01

Soils at geogenically metalliferous sites might exceed heavy metal threshold levels with respect to agricultural use, apart from anthropogenic contamination sources. As a fundamental substrate for green plants and green plant production, soil is not easily renewable, its formation needs long time (e.g. 500 years for 20 mm). In Austria, about 10ha of soil get sealed every day, resulting in complete loss of its biological functions. Excavated soil material has been classified as waste from a legal point of view, which made 33 mill. tons resp. 48% of total waste in Austria in 2010. Recycling of excavated soil material for agricultural use will be an important task to reduce future waste and to enlarge agricultural substrate volumes, but methods to ensure proper qualities are needed to improve regulations. Within this investigation, the transfer of various metals from geogenically metalliferous soils to various crop plants will be investigated, and correlated with various simple soil test methods. Four excavated soil materials from the metalliferous schist zone within the Austrian province of Styria (Kraubath/Mur, Übelbach) and a low-metal reference sample have been taken as substrates to grow raygrass (lolium multiflorum) as a green cover, salad (Lactuca sativa) as a vegetable food item, oats (Avena sativa), maize (Zea mais) and stinging nettle (Urtica dioica) as a hyperaccumulating species. Results and recommendations will be presented.

Excavation Technology for Hard Rock - Problems and Prospects

International Nuclear Information System (INIS)

Gillani, S.T.A.; Butt, N.

2009-01-01

Civil engineering projects have greatly benefited from the mechanical excavation of hard rock technology. Mining industry, on the other hand, is still searching for major breakthroughs to mechanize and then automate the winning of ore and drivage of access tunnels in its metalliferous sector. The aim of this study is to extend the scope of drag bits for road headers in hard rock cutting. Various factors that can impose limitations on the potential applications of drag bits in hard rock mining are investigated and discussed along with alternative technology options. (author)

Stochastic Bifurcation Analysis of an Elastically Mounted Flapping Airfoil

Directory of Open Access Journals (Sweden)

Bose Chandan

2018-01-01

Full Text Available The present paper investigates the effects of noisy flow fluctuations on the fluid-structure interaction (FSI behaviour of a span-wise flexible wing modelled as a two degree-of-freedom elastically mounted flapping airfoil. In the sterile flow conditions, the system undergoes a Hopf bifurcation as the free-stream velocity exceeds a critical limit resulting in a stable limit-cycle oscillation (LCO from a fixed point response. On the other hand, the qualitative dynamics changes from a stochastic fixed point to a random LCO through an intermittent state in the presence of irregular flow fluctuations. The probability density function depicts the most probable system state in the phase space. A phenomenological bifurcation (P-bifurcation analysis based on the transition in the topology associated with the structure of the joint probability density function (pdf of the response variables has been carried out. The joint pdf corresponding to the stochastic fixed point possesses a Dirac delta function like structure with a sharp single peak around zero. As the mean flow speed crosses the critical value, the joint pdf bifurcates to a crater-like structure indicating the occurrence of a P-bifurcation. The intermittent state is characterized by the co-existence of the unimodal as well as the crater like structure.

Stability of Large Parallel Tunnels Excavated in Weak Rocks: A Case Study