WorldWideScience

Sample records for optical zone decentration

  1. The optical axis optimization in measurement of decentration of lens

    Science.gov (United States)

    Wang, Yajing; Yang, Lin; Wang, Chunyu

    2013-09-01

    Measure of optical decentration plays an important role in inspection, installation and adjustment of optical system. This article describes optical measurement principle of decentration, analyzes the reason of the decentration measurement accuracy, and indicates the necessity of optimizing the optical axis. Finally, because of the error of the decentration optical axis fitting. A new method of optical axis optimization is put forward here. A mathematical model to find the best optical axis is established, which improved the optical performance of the system.

  2. Optical performance of toric intraocular lenses in the presence of decentration

    Institute of Scientific and Technical Information of China (English)

    Bin; Zhang; Jin-Xue; Ma; Dan-Yan; Liu; Ying-Hua; Du; Cong-Rong; Guo; Yue-Xian; Cui

    2015-01-01

    · AIM: To evaluate the optical performance of toric intraocular lenses(IOLs) after decentration and with different pupil diameters, but with the IOL astigmatic axis aligned.· METHODS: Optical performances of toric T5 and SN60 AT spherical IOLs after decentration were tested on a theoretical pseudophakic model eye based on the Hwey-Lan Liou schematic eye using the Zemax ray-tracing program. Changes in optical performance were analyzed in model eyes with 3-mm, 4-mm, and 5-mm pupil diameters and decentered from 0.25 mm to 0.75 mm with an interval of 5° at the meridian direction from0° to 90°. The ratio of the modulation transfer function(MTF) between a decentered and a centered IOL(MTFDecentration/MTFCentration) was calculated to analyze the decrease in optical performance.· RESULTS: Optical performance of the toric IOL remained unchanged when IOLs were decentered in any meridian direction. The MTFs of the two IOLs decreased,whereas optical performance remained equivalent after decentration. The MTFDecentration/MTFCentrationratios of the IOLs at a decentration from 0.25 mm to 0.75 mm were comparable in the toric and SN60 AT IOLs. After decentration, MTF decreased further, with the MTF of the toric IOL being slightly lower than that of the SN60 AT IOL. Imaging qualities of the two IOLs decreased when the pupil diameter and the degree of decentration increased, but the decrease was similar in the toric and spherical IOLs.· CONCLUSION: Toric IOLs were comparable to spherical IOLs in terms of tolerance to decentration at the correct axial position.

  3. Decentralized Ground Staff Scheduling

    DEFF Research Database (Denmark)

    Sørensen, M. D.; Clausen, Jens

    2002-01-01

    Typically, ground staff scheduling is centrally planned for each terminal in an airport. The advantage of this is that the staff is efficiently utilized, but a disadvantage is that staff spends considerable time walking between stands. In this paper a decentralized approach for ground staff...... scheduling is investigated. The airport terminal is divided into zones, where each zone consists of a set of stands geographically next to each other. Staff is assigned to work in only one zone and the staff scheduling is planned decentralized for each zone. The advantage of this approach is that the staff...... work in a smaller area of the terminal and thus spends less time walking between stands. When planning decentralized the allocation of stands to flights influences the staff scheduling since the workload in a zone depends on which flights are allocated to stands in the zone. Hence solving the problem...

  4. Fractal zone plate beam based optical tweezers

    Science.gov (United States)

    Cheng, Shubo; Zhang, Xinyu; Ma, Wenzhuo; Tao, Shaohua

    2016-01-01

    We demonstrate optical manipulation with an optical beam generated by a fractral zone plate (FZP). The experimental results show that the FZP beam can simultaneously trap multiple particles positioned in different focal planes of the FZP beam, owing to the multiple foci and self-reconstruction property of the FZP beam. The FZP beam can also be used to construct three-dimensional optical tweezers for potential applications. PMID:27678305

  5. Topographical Evaluation of the Decentration of Orthokeratology Lenses

    Institute of Scientific and Technical Information of China (English)

    Xiao Yang; Xingwu Zhong; Xiangming Gong; Junwen Zeng

    2005-01-01

    Purpose: To evaluate the amount of lens decentration and various factors affecting decentration after orthokeratology lens wear and to observe the effect of decentration on the visual functions.Methods: Two kinds of orthokeratology lenses were fitted to 270 eyes of 135 patients [initial mean refractive error: (-3.98±1.51)D]. Humphery Instruments ATLAS 990 was used for the computer-assisted analysis of corneal topographical maps. The examination of corneal topography was performed on patients before and after 6 months of wearing orthokeratology lenses. The amount of decentration of orthokeratology lenses was measured by finding the distance between center of optic zone and the pupil center. The factors influencing the amount of decentration were analyzed, including the initial refraction error, astigmatism, keratometry values, corneal eccentricity, and the diameter of lens.Visual symptoms including monocular diplopia, glare around lights were recorded to evaluate the effects of decentration on visual functions.Results: The mean amount of decentration was (0.49±0.34) mm after one night's wear.The mean amount of decentration after 1 month, 3 months and 6 months was (0.57±0.41) mm, (0.55±0.48) mm and (0.59±0.39) mm, respectively. After one month, the amount of decentration was less than 0.50 mm in 51.1% eyes, 0.50~1.0 mm in 35.6% eyes and more than 1.00 mm in 13.3% eyes. The direction of decentration of more than 0.50 mm was mainly in the temporal quadrant (48.5%). Patients with greater initial astigmatism and smaller lenses showed greater decentration (P<0.05). There was no statistically significant difference in decentration between the two groups with different corneal eccentricities and keratometry values (P>0.05). The amount of decentration was greater in patients who complained of monocular diplopia and glare.Conclusions: The amount of decentration of orthokeratology depends on the initial refractive error, astigmatism and the design of orthokeratology

  6. Linear optical pulse compression based on temporal zone plates.

    Science.gov (United States)

    Li, Bo; Li, Ming; Lou, Shuqin; Azaña, José

    2013-07-15

    We propose and demonstrate time-domain equivalents of spatial zone plates, namely temporal zone plates, as alternatives to conventional time lenses. Both temporal intensity zone plates, based on intensity-only temporal modulation, and temporal phase zone plates, based on phase-only temporal modulation, are introduced and studied. Temporal zone plates do not exhibit the limiting tradeoff between temporal aperture and frequency bandwidth (temporal resolution) of conventional linear time lenses. As a result, these zone plates can be ideally designed to offer a time-bandwidth product (TBP) as large as desired, practically limited by the achievable temporal modulation bandwidth (limiting the temporal resolution) and the amount of dispersion needed in the target processing systems (limiting the temporal aperture). We numerically and experimentally demonstrate linear optical pulse compression by using temporal zone plates based on linear electro-optic temporal modulation followed by fiber-optics dispersion. In the pulse-compression experiment based on temporal phase zone plates, we achieve a resolution of ~25.5 ps over a temporal aperture of ~5.77 ns, representing an experimental TBP larger than 226 using a phase-modulation amplitude of only ~0.8π rad. We also numerically study the potential of these devices to achieve temporal imaging of optical waveforms and present a comparative analysis on the performance of different temporal intensity and phase zone plates.

  7. Numerical nonwavefront-guided algorithm for expansion or recentration of the optical zone

    Science.gov (United States)

    Arba Mosquera, Samuel; Verma, Shwetabh

    2014-08-01

    Complications may arise due to the decentered ablations during refractive surgery, resulting from human or mechanical errors. Decentration may cause over-/under-corrections, with patients complaining about seeing glares and halos after the procedure. Customized wavefront-guided treatments are often used to design retreatment procedures. However, due to the limitations of wavefront sensors in precisely measuring very large aberrations, some extreme cases may suffer when retreated with wavefront-guided treatments. We propose a simple and inexpensive numerical (nonwavefront-guided) algorithm to recenter the optical zone (OZ) and to correct the refractive error with minimal tissue removal. Due to its tissue-saving capabilities, this method can benefit patients with critical residual corneal thickness. Based on the reconstruction of ablation achieved in the first surgical procedure, we calculate a target ablation (by manipulating the achieved OZ) with adequate centration and an OZ sufficient enough to envelope the achieved ablation. The net ablation map for the retreatment procedure is calculated from the achieved and target ablations and is suitable to expand, recenter, and modulate the lower-order refractive components in a retreatment procedure. The results of our simulations suggest minimal tissue removal with OZ centration and expansion. Enlarging the OZ implies correcting spherical aberrations, whereas inducing centration implies correcting coma. This method shows the potential to improve visual outcomes in extreme cases of retreatment, possibly serving as an uncomplicated and inexpensive alternative to wavefront-guided retreatments.

  8. Organizational decentralization in radiology.

    Science.gov (United States)

    Aas, I H Monrad

    2006-01-01

    At present, most hospitals have a department of radiology where images are captured and interpreted. Decentralization is the opposite of centralization and means 'away from the centre'. With a Picture Archiving and Communication System (PACS) and broadband communications, transmitting radiology images between sites will be far easier than before. Qualitative interviews of 26 resource persons were performed in Norway. There was a response rate of 90%. Decentralization of radiology interpretations seems less relevant than centralization, but several forms of decentralization have a role to play. The respondents mentioned several advantages, including exploitation of capacity and competence. They also mentioned several disadvantages, including splitting professional communities and reduced contact between radiologists and clinicians. With the new technology decentralization and centralization of image interpretation are important possibilities in organizational change. This will be important for the future of teleradiology.

  9. Decentralized energy studies: bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, J.M.; Unseld, C.T.; Levine, A.; Silversmith, J.A.

    1980-05-01

    This bibliography is a compilation of literature on decentralized energy systems. It is arranged according to topical (e.g., lifestyle and values, institutions, and economics) and geographical scale to facilitate quick reference to specific areas of interest. Also included are articles by and about Amory B. Lovins who has played a pivotal role in making energy decentralization an important topic of national debate. Periodicals, other bibliographies, and directories are also listed.

  10. Exclusion-Zone Dynamics Explored with Microfluidics and Optical Tweezers

    Directory of Open Access Journals (Sweden)

    István N. Huszár

    2014-08-01

    Full Text Available The exclusion zone (EZ is a boundary region devoid of macromolecules and microscopic particles formed spontaneously in the vicinity of hydrophilic surfaces. The exact mechanisms behind this remarkable phenomenon are still not fully understood and are debated. We measured the short- and long-time-scale kinetics of EZ formation around a Nafion gel embedded in specially designed microfluidic devices. The time-dependent kinetics of EZ formation follow a power law with an exponent of 0.6 that is strikingly close to the value of 0.5 expected for a diffusion-driven process. By using optical tweezers we show that exclusion forces, which are estimated to fall in the sub-pN regime, persist within the fully-developed EZ, suggesting that EZ formation is not a quasi-static but rather an irreversible process. Accordingly, the EZ-forming capacity of the Nafion gel could be exhausted with time, on a scale of hours in the presence of 1 mM Na2HPO4. EZ formation may thus be a non-equilibrium thermodynamic cross-effect coupled to a diffusion-driven transport process. Such phenomena might be particularly important in the living cell by providing mechanical cues within the complex cytoplasmic environment.

  11. Decentralization and Governance in Indonesia

    NARCIS (Netherlands)

    Holzhacker, Ronald; Wittek, Rafael; Woltjer, Johan

    2016-01-01

    I. Theoretical Reflections on Decentralization and Governance for Sustainable Society 1. Decentralization and Governance for Sustainable Society in Indonesia Ronald Holzhacker, Rafael Wittek and Johan Woltjer 2. Good Governance Contested: Exploring Human Rights and Sustainability as Normative Goals

  12. Decentralizing Agricultural Extension: Alternative Strategies.

    Science.gov (United States)

    Rivera, William M.

    1997-01-01

    Examines government strategies for decentralizing agricultural extension, concluding that such changes are largely determined by the country's constitutional status. Reviews decentralization guidelines for structural and fiscal reforms and participatory management systems. (SK)

  13. Territorial Decentration and Geographic Learning.

    Science.gov (United States)

    Stoltman, Joseph P.

    Territorial decentration is a question of major significance to geographic educators. This paper reports the findings of a research project designed to determine the territorial decentration of an American sample of children. The primary purpose of the research was to determine if Piaget's territorial decentration stages are appropriate for…

  14. Decentralization and Participation: the Montevidian Experience

    Directory of Open Access Journals (Sweden)

    María del Rosario Revello

    1999-10-01

    Full Text Available Beginning with the proposition that a true process of decentralization must necessarily be a process of democratization, such a process is understood as a privileged instrument for participation. Indeed, for a deepening of democratic practices, the ways which should be taken are via decentralization and social participation. This article describes and analyzes the experience of decentralization in Montevideo, a fundamental project created by the coalition of leftist parties that have governed the capital of Uruguay since 1990, a project which had no historical antecedents in the country. The department of Montevideo divided into 18 zones and created juntas locales (local boards - local, decentralized politicalorgans with representation from all the parties - and neighborhood councils. The Neighborhood Councils are representative organs that voice the neighborhood’s interests. Not integrated in the public municipal structure, these constitute private civil society organizations. They are consultative and consultancy bodies with the important tasks of initiative and proposal, planning, consultation, evaluation and the control over the communal management. Also described in the article is the methodology for the project’s improvement and progressive sophistication, which is in function of, among other factors, the degree of effectiveness and reaching of objectives that emerge from the permanent control and evaluation carried out year to year. The strategy presented emphasizes the need for ensuring that the community directly monitors and controls the process of municipal management to safeguard the democratic character of the process.

  15. The Rhetoric of Decentralization

    Science.gov (United States)

    Ravitch, Diane

    1974-01-01

    Questions the rationale for and possible consequences of political decentralization of New York City. Suggests that the disadvantages--reduced level of professionalism, increased expense in multiple government operation, "stabilization" of residential segregation, necessity for budget negotiations because of public disclosure of tax structure and…

  16. Analyzing Von Neumann machines using decentralized symmetries

    Science.gov (United States)

    Fang, Jie

    2013-10-01

    The artificial intelligence method to e-business is defined not only by the study of fiber-optic cables, but also by the unproven need for vacuum tubes. Given the current status of virtual archetypes, theorists clearly desire the exploration of semaphores, which embodies the compelling principles of cryptoanalysis. We present an algorithm for probabilistic theory (Buck), which we use to disprove that write-back caches can be made decentralized, lossless, and reliable.

  17. Decentralized Portfolio Management

    Directory of Open Access Journals (Sweden)

    Benjamin Miranda Tabak

    2003-12-01

    Full Text Available We use a mean-variance model to analyze the problem of decentralized portfolio management. We find the solution for the optimal portfolio allocation for a head trader operating in n different markets, which is called the optimal centralized portfolio. However, as there are many traders specialized in different markets, the solution to the problem of optimal decentralized allocation should be different from the centralized case. In this paper we derive conditions for the solutions to be equivalent. We use multivariate normal returns and a negative exponential function to solve the problem analytically. We generate the equivalence of solutions by assuming that different traders face different interest rates for borrowing and lending. This interest rate is dependent on the ratio of the degrees of risk aversion of the trader and the head trader, on the excess return, and on the correlation between asset returns.

  18. Decentralized Constraint Satisfaction

    CERN Document Server

    Duffy, K R; Leith, D J

    2011-01-01

    Constraint satisfaction problems (CSPs) lie at the heart of many modern industrial and commercial tasks. An important new collection of CSPs has recently been emerging that differ from classical problems in that they impose constraints on the class of algorithms that can be used to solve them. In computer network applications, these constraints arise as the variables within the CSP are located at physically distinct devices that cannot communicate. At each instant, every variable only knows if all its constraints are met or at least one is not. Consequently, the CSP's solution must be found using a decentralized approach. Existing algorithms for solving CSPs are either centralized or distributed, both of which violate these algorithmic constraints. In this article we present the first algorithm for solving CSPs that fulfills these new requirements. It is fully decentralized, making no use of a centralized controller or message-passing between variables. We prove that this algorithm converges with probability ...

  19. Policy Implementation Decentralization Government in Indonesia

    Directory of Open Access Journals (Sweden)

    Kardin M. Simanjuntak

    2015-06-01

    Full Text Available Decentralization in Indonesia is that reforms not completed and until the current implementation is not maximized or have not been successful. The essence of decentralization is internalising cost and benefit' for the people and how the government closer to the people. That's the most important essence of essence 'decentralization’. However, the implementation of decentralization in Indonesia is still far from the expectations. It is shown that only benefits of decentralization elite and local authorities, decentralization is a neo-liberal octopus, decentralization of public services are lacking in character, decentralization without institutional efficiency, decentralization fosters corruption in the area, and quasi-fiscal decentralization.

  20. Influence of array photodetectors characteristics on the accuracy of the optical-electronic system with optical equisignal zone

    Science.gov (United States)

    Gusarov, Vadim F.; Maraev, Anton A.; Timofeev, Aleksandr N.; Klimov, Aleksandr A.

    2016-04-01

    In this paper we attempt to assess the possibility of applying the array of photodetectors and digital information processing in positioning systems based on optical equisignal zone. The basic theoretical information about working principles of the system with equisignal zone and the formation of the base direction are listed. The influence on the accuracy of the positioning system some parameters such as the number and size of the array elements of the receiver, capacity analog-digital converter, aberrations of optical elements are researched. The possibility of registering the angular displacements (reversals) of the controlled object by using the developed system is shown.

  1. Decentral Smart Grid Control

    Science.gov (United States)

    Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

    2015-01-01

    Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals.

  2. Experimental observation and investigation of the prewave zone effect in optical diffraction radiation

    Directory of Open Access Journals (Sweden)

    P. Karataev

    2008-03-01

    Full Text Available Transition radiation (TR and diffraction radiation (DR has widely been used for both electron beam diagnostics and generation of intense radiation beams in the millimeter and the submillimeter wavelength range. Recently, it was theoretically predicted that TR and DR properties change either at extremely high energies of electrons or at long radiation wavelengths. This phenomenon was called a prewave zone effect. We have performed the first observation and detailed investigation of the prewave zone effect in optical diffraction radiation at 1.28 GeV electron beam at the KEK-Accelerator Test Facility (KEK-ATF. The beam energy at KEK-ATF is definitely not the highest one achieved in the world. Since we could easily observe the effect, at higher energies it might cause serious problems. We developed and applied a method for prewave zone suppression valid for optical wavelengths. Furthermore, a method for prewave zone suppression applicable for longer radiation wavelengths is discussed.

  3. Internal fingerprint zone detection in optical coherence tomography fingertip scans

    CSIR Research Space (South Africa)

    Darlow, LN

    2015-04-01

    Full Text Available Optical coherence tomography (OCT) is a high-resolution imaging technology capable of capturing a three-dimensional (3-D) representation of fingertip skin. The papillary junction—a junction layer of skin containing the same topographical features...

  4. Design of extended viewing zone at autostereoscopic 3D display based on diffusing optical element

    Science.gov (United States)

    Kim, Min Chang; Hwang, Yong Seok; Hong, Suk-Pyo; Kim, Eun Soo

    2012-03-01

    In this paper, to realize a non-glasses type 3D display as next step from the current glasses-typed 3D display, it is suggested that a viewing zone is designed for the 3D display using DOE (Diffusing Optical Element). Viewing zone of proposed method is larger than that of the current parallax barrier method or lenticular method. Through proposed method, it is shown to enable the expansion and adjustment of the area of viewing zone according to viewing distance.

  5. On Decentralization and Life Satisfaction

    DEFF Research Database (Denmark)

    Bjørnskov, Christian; Dreher, Axel; Fischer, Justina A.V.

    2008-01-01

    We empirically analyze the impact of fiscal and political decentralization on subjective well-being in a cross-section of 60,000 individuals from 66 countries. More spending or revenue decentralization raises well-being while greater local autonomy is beneficial only via government consumption...

  6. On Decentralization and Life Satisfaction

    DEFF Research Database (Denmark)

    Bjørnskov, Christian; Dreher, Axel; Fischer, Justina A.V.

    2008-01-01

    We empirically analyze the impact of fiscal and political decentralization on subjective well-being in a cross-section of 60,000 individuals from 66 countries. More spending or revenue decentralization raises well-being while greater local autonomy is beneficial only via government consumption...

  7. Centralized versus Decentralized Information Systems

    Science.gov (United States)

    Hugoson, Mats-Åke

    This paper brings into question whether information systems should be centralized or decentralized in order to provide greater support for different business processes. During the last century companies and organizations have used different approaches for centralization and decentralization; a simple answer to the question does not exist. This paper provides a survey of the evolution of centralized and decentralized approaches, mainly in a Nordic perspective. Based on critical reflections on the situation in the end of the century we can discuss what we can learn from history to achieve alignment between centralized and decentralized systems and the business structure. The conclusion is that theories, management and practice for decisions on centralization or decentralization of information systems must be improved. A conscious management and control of centralization /decentralization of IT support is a vital question in the company or the organization, and this is not a task that can be handled only by IT-specialists. There is a need for business oriented IT management of centralization/decentralization.

  8. Coalition or decentralization

    DEFF Research Database (Denmark)

    Mahdiraji, Hannan Amoozad; Govindan, Kannan; Zavadskas, Edmundas Kazimieras

    2014-01-01

    Supply chains have become the major and dominant paradigm of business and competition. The main challenge is how to act in multi-echelon supply chains considering the levels involved. Making a choice independently or integrating with some or all levels will be a critical decision, and therefore...... affects the overall profit of the chain. This article proposes a non-cooperative game theory approach to helping in making a better decision in the supply chain and gaining the most accessible benefit. Our research considers unlimited three-echelon supply chains with S suppliers, M manufacturers and K...... retailers. The Nash equilibrium and definition are used bearing in mind inventory and pricing and marketing cost as decision variables for this matter. This paper studies a three-echelon supply chain network and focuses on the value of integrating a pair of partners in the chain. In the decentralized case...

  9. Coalition or decentralization

    DEFF Research Database (Denmark)

    Mahdiraji, Hannan Amoozad; Govindan, Kannan; Zavadskas, Edmundas Kazimieras

    2014-01-01

    retailers. The Nash equilibrium and definition are used bearing in mind inventory and pricing and marketing cost as decision variables for this matter. This paper studies a three-echelon supply chain network and focuses on the value of integrating a pair of partners in the chain. In the decentralized case...... affects the overall profit of the chain. This article proposes a non-cooperative game theory approach to helping in making a better decision in the supply chain and gaining the most accessible benefit. Our research considers unlimited three-echelon supply chains with S suppliers, M manufacturers and K......, the supplier sets its own price, the manufacturer points out order quantity, wholesale price and backorder quantity, and the retailer charges the final retail price of the product and marketing product. Though there are multiple players at a single echelon level, each manufacturer supplies only a specific...

  10. Analysis of dead zone sources in a closed-loop fiber optic gyroscope.

    Science.gov (United States)

    Chong, Kyoung-Ho; Choi, Woo-Seok; Chong, Kil-To

    2016-01-01

    Analysis of the dead zone is among the intensive studies in a closed-loop fiber optic gyroscope. In a dead zone, a gyroscope cannot detect any rotation and produces a zero bias. In this study, an analysis of dead zone sources is performed in simulation and experiments. In general, the problem is mainly due to electrical cross coupling and phase modulation drift. Electrical cross coupling is caused by interference between modulation voltage and the photodetector. The cross-coupled signal produces spurious gyro bias and leads to a dead zone if it is larger than the input rate. Phase modulation drift as another dead zone source is due to the electrode contamination, the piezoelectric effect of the LiNbO3 substrate, or to organic fouling. This modulation drift lasts for a short or long period of time like a lead-lag filter response and produces gyro bias error, noise spikes, or dead zone. For a more detailed analysis, the cross-coupling effect and modulation phase drift are modeled as a filter and are simulated in both the open-loop and closed-loop modes. The sources of dead zone are more clearly analyzed in the simulation and experimental results.

  11. Decentralization Calls for Internal Audits.

    Science.gov (United States)

    DiCello, Jim

    1995-01-01

    Outlines internal-auditing strategies necessitated by decentralization. Describes the following areas of concern: the student activities account, student attendance, and funding delegated to the site level. Guidelines for conducting an internal audit are also included. (LMI)

  12. Decentralization Calls for Internal Audits.

    Science.gov (United States)

    DiCello, Jim

    1995-01-01

    Outlines internal-auditing strategies necessitated by decentralization. Describes the following areas of concern: the student activities account, student attendance, and funding delegated to the site level. Guidelines for conducting an internal audit are also included. (LMI)

  13. Predictability and stability of refraction with increasing optical zone diameter in hyperopic LASIK

    Directory of Open Access Journals (Sweden)

    Mostafa A El-Helw

    2010-05-01

    Full Text Available Mostafa A El-Helw, Ahmed M EmarahCairo University, Cairo, EgyptObjective: We undertook a prospective nonrandomized study to assess refractive outcome and patient satisfaction with hyperopic laser in situ keratomileusis (LASIK using variable optical zone diameters in correction of hyperopia of more than 4.00 diopters.Methods: Fourteen adults (comprising 28 hyperopic eyes underwent hyperopic LASIK correction for hyperopia of more than 4.00 diopters. The sample was divided into two groups. Group 1 included the right eyes of the 14 patients who underwent hyperopic LASIK using a 6.5 mm optical zone diameter. Group 2 comprised the left eyes of the same patients with the only difference being that the optical zone diameter was 6.0 mm.Results: The mean age of the patients was 36.42 ± 5.10 years. Group 1 eyes had a median (range preoperative uncorrected visual acuity (UCVA of 0.79 (0.52 and best-corrected visual acuity (BCVA of 0.15 (0.08. Group 2 had a median preoperative UCVA of 0.79 (0.60 and BCVA of 0.15 (0.08. The median postoperative UCVA in Group 1 was 0.17 (0.21 and BCVA was 0.15 (0.13. In Group 2, the median postoperative UCVA was 0.30 (0.32 and BCVA was 0.15 (0.26. Group 1 had a median preoperative refraction of +5.37 (1.75 diopters and the median postoperative refraction at one week was −0.23 (1.25 diopters, at three months was +0.75 (0.75 diopters, and at six months was +0.75 (1.00 diopters. Group 2 had a median preoperative refraction of +5.00 (1.75 diopters, and the median postoperative refraction at one week was +0.13 (1.5 diopters, at three months was +1.00 (0.75 diopters and at six months +1.25 (1.25 diopters. The difference was statistically significant between groups 1 and 2. The difference within each group was also significant. Group 1 eyes were stabilizing after the three-month period in contrast with Group 2 in which the refractive changes continued throughout the follow-up period.Conclusion: Larger optical zone diameter in

  14. Partial decentralization as a safeguard against favoritism

    OpenAIRE

    Cortés Cortés, Darwin Fauricio

    2010-01-01

    In this paper I investigate the optimal level of decentralization of tasks for the provision of a local public good. I enrich the well-known trade-off between internalization of spillovers (that favors centralization) and accountability (that favors decentralization) by considering that public goods are produced through multiple tasks. This adds an additional institutional setting, partial decentralization, to the classical choice between full decentralization and full centralization. The mai...

  15. Decentralized Decision-Making. ERS Information Aid.

    Science.gov (United States)

    Powell, Janet F.

    In this paper, the current debate over decentralized decisionmaking is highlighted and facts, figures, and models based on a recent nationwide survey are presented. Decentralization in decisionmaking is defined as the involvement of building-level principals in district-wide decisions. Advantages and disadvantages of decentralization, the nature…

  16. Rethinking Partnerships on a Decentralized Campus

    Science.gov (United States)

    Dufault, Katie H.

    2017-01-01

    Decentralization is an effective approach for structuring campus learning and success centers. McShane & Von Glinow (2007) describe decentralization as "an organizational model where decision authority and power are dispersed among units rather than held by a single small group of administrators" (p. 237). A decentralized structure…

  17. Light comfort zones of mesopelagic acoustic scattering layers in two contrasting optical environments

    KAUST Repository

    Røstad, Anders

    2016-03-31

    We make a comparison of the mesopelagic sound scattering layers (SLs) in two contrasting optical environments; the clear Red Sea and in murkier coastal waters of Norway (Masfjorden). The depth distributions of the SL in Masfjorden are shallower and narrower than those of the Red Sea. This difference in depth distribution is consistent with the hypothesis that the organisms of the SL distribute according to similar light comfort zones (LCZ) in the two environments. Our study suggest that surface and underwater light measurements ranging more than10 orders of magnitude is required to assess the controlling effects of light on SL structure and dynamics.

  18. Experimental evidence of zone-center optical phonon softening by accumulating holes in thin Ge

    Energy Technology Data Exchange (ETDEWEB)

    Kabuyanagi, Shoichi; Nishimura, Tomonori; Yajima, Takeaki; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656 (Japan)

    2016-01-15

    We discuss the impact of free carriers on the zone-center optical phonon frequency in germanium (Ge). By taking advantage of the Ge-on-insulator structure, we measured the Raman spectroscopy by applying back-gate bias. Phonon softening by accumulating holes in Ge film was clearly observed. This fact strongly suggests that the phonon softening in heavily-doped Ge is mainly attributed to the free carrier effect rather than the dopant atom counterpart. Furthermore, we propose that the free carrier effect on phonon softening is simply understandable from the viewpoint of covalent bonding modification by free carriers.

  19. Computerized Systems: Centralized or Decentralized?

    Science.gov (United States)

    Seitz, Linda Ludington

    1985-01-01

    Computerized management information systems have long been used in business, and data integration and sophisticated programing now enable many businesses to decentralize their information operations. This approach has advantages and disadvantages that colleges and universities must weigh and plan for carefully. (MSE)

  20. Music Libraries: Centralization versus Decentralization.

    Science.gov (United States)

    Kuyper-Rushing, Lois

    2002-01-01

    Considers the decision that branch libraries, music libraries in particular, have struggled with concerning a centralized location in the main library versus a decentralized collection. Reports on a study of the Association of Research Libraries that investigated the location of music libraries, motivation for the location, degrees offered,…

  1. Decentralized neural control application to robotics

    CERN Document Server

    Garcia-Hernandez, Ramon; Sanchez, Edgar N; Alanis, Alma y; Ruz-Hernandez, Jose A

    2017-01-01

    This book provides a decentralized approach for the identification and control of robotics systems. It also presents recent research in decentralized neural control and includes applications to robotics. Decentralized control is free from difficulties due to complexity in design, debugging, data gathering and storage requirements, making it preferable for interconnected systems. Furthermore, as opposed to the centralized approach, it can be implemented with parallel processors. This approach deals with four decentralized control schemes, which are able to identify the robot dynamics. The training of each neural network is performed on-line using an extended Kalman filter (EKF). The first indirect decentralized control scheme applies the discrete-time block control approach, to formulate a nonlinear sliding manifold. The second direct decentralized neural control scheme is based on the backstepping technique, approximated by a high order neural network. The third control scheme applies a decentralized neural i...

  2. Wage Dispersion and Decentralization of Wage Bargaining

    DEFF Research Database (Denmark)

    Dahl, Christian M.; Le Maire, Christian Daniel; Munch, Jakob Roland

    This paper studies how decentralization of wage bargaining from sector to firm level influences wage levels and wage dispersion. We use a detailed panel data set covering a period of decentralization in the Danish labor market. The decentralization process provides exogenous variation in the indi......This paper studies how decentralization of wage bargaining from sector to firm level influences wage levels and wage dispersion. We use a detailed panel data set covering a period of decentralization in the Danish labor market. The decentralization process provides exogenous variation...... in the individual worker's wage-setting system that facilitates identification of the effects of decentralization. Consistent with predictions we find that wages are more dispersed under firm-level bargaining compared to more centralized wage-setting systems. However, the differences across wage-setting systems...

  3. The Two Edge Knife of Decentralization

    Directory of Open Access Journals (Sweden)

    Ahmad Khoirul Umam

    2011-07-01

    Full Text Available A centralistic government model has become a trend in a number of developing countries, in which the ideosycretic aspect becomes pivotal key in the policy making. The situation constitutes authoritarianism, cronyism, and corruption. To break the impasse, the decentralized system is proposed to make people closer to the public policy making. Decentralization is also convinced to be the solution to create a good governance. But a number of facts in the developing countries demonstrates that decentralization indeed has ignite emerges backfires such as decentralized corruption, parochialism, horizontal conflict, local political instability and others. This article elaborates the theoretical framework on decentralization's ouput as the a double-edge knife. In a simple words, the concept of decentralization does not have a permanent relationship with the creation of good governance and development. Without substantive democracy, decentralization is indeed potential to be a destructive political instrument threating the state's future.

  4. Decentralization and REDD+ in Brazil

    Directory of Open Access Journals (Sweden)

    Fabiano Toni

    2011-01-01

    Full Text Available Recent discussions on REDD+ (Reducing Emissions from Deforestation and Forest Degradation, plus conservation, sustainable management of forests and enhancement of forest carbon stocks have raised optimism about reducing carbon emissions and deforestation in tropical countries. If approved under the United Nations Framework Convention on Climate Change (UNFCCC, REDD+ mechanisms may generate a substantial influx of financial resources to developing countries. Some authors argue that this money could reverse the ongoing process of decentralization of forest policies that has spread through a large number of developing countries in the past two decades. Central states will be accountable for REDD+ money, and may be compelled to control and keep a significant share of REDD+ funds. Supporters of decentralization argue that centralized implementation of REDD+ will be ineffective and inefficient. In this paper, I examine the relation between subnational governments and REDD+ in Brazil. Data show that some state governments in the Brazilian Amazon have played a key role in creating protected areas (PAs after 2003, which helped decrease deforestation rates. Governors have different stimuli for creating PAs. Some respond to the needs of their political constituency; others have expectations to boost the forest sector so as to increase fiscal revenues. Governors also have led the discussion on REDD+ in Brazil since 2008. Considering their interests and political power, REDD+ is unlikely to curb decentralization in Brazil.

  5. Decentralization and Economic Growth per capita in Europe

    OpenAIRE

    Crucq, Pieter; Hemminga, Hendrik-Jan

    2007-01-01

    In this paper the relationship between decentralization and economic growth is investigated. The focus is on decentralization from the national government to the highest substate level in a country, which we define as regional decentralization. Section 2 discusses the different dimensions of decentralization. Political decentralization refers to the degree to which central governments allow non-central government entities to implement certain political functions. Fiscal decentralization in a ...

  6. Growth of Nd{sub 2}TiO{sub 5} single crystal using optical floating zone technique

    Energy Technology Data Exchange (ETDEWEB)

    Murugesan, G.; Kalainathan, S., E-mail: kalainathan@yahoo.com [Centre for Crystal Growth, School of Advanced Sciences, VIT University, Vellore-632014 (India); Nithya, R.; Ravindran, T. R. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102 (India)

    2015-06-24

    Single crystals of Nd{sub 2}TiO{sub 5} were grown using Optical Floating zone technique in oxygen atmosphere by spontaneous nucleation. Powder X-ray diffraction pattern showed that the grown single crystal is of homogeneous composition. Laue diffraction was recorded in both transmission and backscattering geometries to check the crystal quality. Vibrational properties were analyzed using Raman measurements.

  7. Educational Decentralization: Weak State or Strong State?

    Science.gov (United States)

    McGinn, Noel; Street, Susan

    1986-01-01

    A government is a complex system of competing factions that adopts a decentralization policy when the dominant group sees current government structures or procedures as an obstacle to the realization of group interests. Case studies of educational decentralization in Peru, Chile, and Mexico demonstrate that the "state" tends to share…

  8. What supervisors want to know about decentralization.

    Science.gov (United States)

    Boissoneau, R; Belton, P

    1991-06-01

    Many organizations in various industries have tended to move away from strict centralization, yet some centralization is still vital to top management. With 19 of the 22 executives interviewed favoring or implementing some form of decentralization, it is probable that traditionally centralized organizations will follow the trend and begin to decentralize their organizational structures. The incentives and advantages of decentralization are too attractive to ignore. Decentralization provides responsibility, clear objectives, accountability for results, and more efficient and effective decision making. However, one must remember that decentralization can be overextended and that centralization is still viable in certain functions. Finding the correct balance between control and autonomy is a key to decentralization. Too much control and too much autonomy are the primary reasons for decentralization failures. In today's changing, competitive environment, structures must be continuously redefined, with the goal of finding an optimal balance between centralization and decentralization. Organizations are cautioned not to seek out and install a single philosopher-king to impose unified direction, but to unify leadership goals, participation, style, and control to develop improved methods of making all responsible leaders of one mind about the organization's needs and goals.

  9. Wind Farm Decentralized Dynamic Modeling With Parameters

    DEFF Research Database (Denmark)

    Soltani, Mohsen; Shakeri, Sayyed Mojtaba; Grunnet, Jacob Deleuran;

    2010-01-01

    Development of dynamic wind flow models for wind farms is part of the research in European research FP7 project AEOLUS. The objective of this report is to provide decentralized dynamic wind flow models with parameters. The report presents a structure for decentralized flow models with inputs from...

  10. Wage Dispersion and Decentralization of Wage Bargaining

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; le Maire, Christian Daniel; Munch, Jakob R.

    2013-01-01

    's wage-setting system that facilitates identification of the effects of decentralization. We find a wage premium associated with firm-level bargaining relative to sector-level bargaining and that the return to skills is higher under the more decentralized wage-setting systems. Using quantile regression...

  11. Optically inscribed surface-relief zone plates in azo polymer films

    Institute of Scientific and Technical Information of China (English)

    Jun Yang; Bin Guo; Douguo Zhang; Pei Wang; Hai Ming

    2007-01-01

    We describe a simple and cost-effective holographic method for the fabrication of surface-relief zone plates.The zone plate is inscribed by interference between the first- and second-order diffracted waves from an ionetched Fresnel zone plate. The inscribed surface-relief zone plates are observed by atomic force microscope (AFM). The formation process of the surface grating and the mass diffusion in azo polymer are analyzed.

  12. Decentralization and Economic Growth per capita in Europe

    NARCIS (Netherlands)

    Crucq, Pieter; Hemminga, Hendrik-Jan

    2007-01-01

    In this paper the relationship between decentralization and economic growth is investigated. The focus is on decentralization from the national government to the highest substate level in a country, which we define as regional decentralization. Section 2 discusses the different dimensions of decentr

  13. Centralized versus Decentralized Infrastructure Networks

    CERN Document Server

    Hines, Paul D H; Schläpfer, Markus

    2015-01-01

    While many large infrastructure networks, such as power, water, and natural gas systems, have similar physical properties governing flows, these systems tend to have distinctly different sizes and topological structures. This paper seeks to understand how these different size-scales and topological features can emerge from relatively simple design principles. Specifically, we seek to describe the conditions under which it is optimal to build decentralized network infrastructures, such as a microgrid, rather than centralized ones, such as a large high-voltage power system. While our method is simple it is useful in explaining why sometimes, but not always, it is economical to build large, interconnected networks and in other cases it is preferable to use smaller, distributed systems. The results indicate that there is not a single set of infrastructure cost conditions under which optimally-designed networks will have highly centralized architectures. Instead, as costs increase we find that average network size...

  14. Bitcoin as a decentralized currency

    Directory of Open Access Journals (Sweden)

    Dinić Vladimir

    2014-01-01

    Full Text Available Bitcoin is the first decentralized peer-to-peer crypto-currency founded in 2009. Its main specificity is the fact that there is no issuer of this currency. On the other hand, the supply of this currency is software-programmed and limited. Among other things, its main features are relatively secure payments, low transaction costs, anonymity, inability of counterfeiting, irreversibility of transactions, but also extremely unstable exchange rate. Despite many advantages, the use of this currency is subject of numerous discussions, as this currency offers the possibility of performing various abuses and criminal activities. The future of this and other currencies in this regard depends on both security and privacy of these currencies, and legal regulation of such payments.

  15. Decentralized Procurement in Light of Strategic Inventories

    DEFF Research Database (Denmark)

    Arya, Anil; Frimor, Hans; Mittendorf, Brian

    2014-01-01

    The centralization versus decentralization choice is perhaps the quintessential organizational structure decision. In the operations realm, this choice is particularly critical when it comes to the procurement function. Why firms may opt to decentralize procurement has been often studied...... and confirmed to be a multifaceted choice. This paper complements existing studies by detailing the trade-offs in the centralization versus decentralization decision in light of firm's decision to cede procurement choices to its individual devisions can help moderate inventory levels and provide a natural salve...

  16. Statistical mapping of zones of focused groundwater/surface-water exchange using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Mwakanyamale, Kisa; Day-Lewis, Frederick D.; Slater, Lee D.

    2013-01-01

    Fiber-optic distributed temperature sensing (FO-DTS) increasingly is used to map zones of focused groundwater/surface-water exchange (GWSWE). Previous studies of GWSWE using FO-DTS involved identification of zones of focused GWSWE based on arbitrary cutoffs of FO-DTS time-series statistics (e.g., variance, cross-correlation between temperature and stage, or spectral power). New approaches are needed to extract more quantitative information from large, complex FO-DTS data sets while concurrently providing an assessment of uncertainty associated with mapping zones of focused GSWSE. Toward this end, we present a strategy combining discriminant analysis (DA) and spectral analysis (SA). We demonstrate the approach using field experimental data from a reach of the Columbia River adjacent to the Hanford 300 Area site. Results of the combined SA/DA approach are shown to be superior to previous results from qualitative interpretation of FO-DTS spectra alone.

  17. Single crystal growth of Sr{sub 2}TiMnO{sub 6} by optical floating zone technique

    Energy Technology Data Exchange (ETDEWEB)

    Murugesan, G.; Kalainathan, S. [Centre for Crystal Growth, School of Advanced Sciences, VIT University, Vellore 632 014, Tamil Nadu (India); Nithya, R. [Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Das, Amitabh [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai – 400085 (India)

    2016-05-23

    Single crystals of Sr{sub 2}TiMnO{sub 6} were grown by optical floating zone technique. Powder X-ray diffraction studies confirmed the single phase nature of the grown crystal. Laue diffraction studies proved the quality of the grown crystal. Neutron diffraction showed no magnetic ordering down to 6 K. Impedance studies showed temperature dependant relaxation which is due to the presence of oxygen vacancies in the grown crystal.

  18. The effects of fiscal decentralization in Albania

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Blerta Dragusha

    2012-06-01

    Full Text Available “Basically decentralization is a democratic reform which seeks to transfer the political, administrative, financial and planning authority from central to local government. It seeks to develop civic participation, empowerment of local people in decision making process and to promote accountability and reliability: To achieve efficiency and effectiveness in the collection and management of resources and service delivery”1 The interest and curiosity of knowing how our country is doing in this process, still unfinished, served as a motivation forme to treat this topic: fiscal decentralization as a process of giving 'power' to local governments, not only in terms of rights deriving from this process but also on the responsibilities that come with it. Which are the stages before and after decentralization, and how has it affected the process in several key indicators? Is decentralization a good process only, or can any of its effects be seen as an disadvantage?

  19. Modeling Decentralized Organizational Change in Honeybee Societies

    OpenAIRE

    Hoogendoorn, Mark; Schut, Martijn; Treur, Jan

    2006-01-01

    Multi-agent organizations in dynamic environments, need to have the ability to adapt to environmental changes to ensure a continuation of proper functioning. Such adaptations can be made through a centralized decision process or come from the individuals within the organization. In the domain of social insects, such as honeybees and wasps, organizations are known to adapt in a decentralized fashion to environmental changes. An organizational model for decentralized organizational change is pr...

  20. The Two Edge Knife of Decentralization

    OpenAIRE

    Ahmad Khoirul Umam

    2011-01-01

    A centralistic government model has become a trend in a number of developing countries, in which the ideosycretic aspect becomes pivotal key in the policy making. The situation constitutes authoritarianism, cronyism, and corruption. To break the impasse, the decentralized system is proposed to make people closer to the public policy making. Decentralization is also convinced to be the solution to create a good governance. But a number of facts in the developing countries demonstrates that dec...

  1. Decentralized network management based on mobile agent

    Institute of Scientific and Technical Information of China (English)

    李锋; 冯珊

    2004-01-01

    The mobile agent technology can be employed effectively for the decentralized management of complex networks. We show how the integration of mobile agent with legacy management protocol, such as simple network management protocol (SNMP), leads to decentralized management architecture. HostWatcher is a framework that allows mobile agents to roam network, collect and process data, and perform certain adaptive actions. A prototype system is built and a quantitative analysis underlines the benefits in respect to reducing network load.

  2. Decentralized Consistent Updates in SDN

    KAUST Repository

    Nguyen, Thanh Dang

    2017-04-10

    We present ez-Segway, a decentralized mechanism to consistently and quickly update the network state while preventing forwarding anomalies (loops and blackholes) and avoiding link congestion. In our design, the centralized SDN controller only pre-computes information needed by the switches during the update execution. This information is distributed to the switches, which use partial knowledge and direct message passing to efficiently realize the update. This separation of concerns has the key benefit of improving update performance as the communication and computation bottlenecks at the controller are removed. Our evaluations via network emulations and large-scale simulations demonstrate the efficiency of ez-Segway, which compared to a centralized approach, improves network update times by up to 45% and 57% at the median and the 99th percentile, respectively. A deployment of a system prototype in a real OpenFlow switch and an implementation in P4 demonstrate the feasibility and low overhead of implementing simple network update functionality within switches.

  3. Decentralized and Modular Electrical Architecture

    Science.gov (United States)

    Elisabelar, Christian; Lebaratoux, Laurence

    2014-08-01

    This paper presents the studies made on the definition and design of a decentralized and modular electrical architecture that can be used for power distribution, active thermal control (ATC), standard inputs-outputs electrical interfaces.Traditionally implemented inside central unit like OBC or RTU, these interfaces can be dispatched in the satellite by using MicroRTU.CNES propose a similar approach of MicroRTU. The system is based on a bus called BRIO (Bus Réparti des IO), which is composed, by a power bus and a RS485 digital bus. BRIO architecture is made with several miniature terminals called BTCU (BRIO Terminal Control Unit) distributed in the spacecraft.The challenge was to design and develop the BTCU with very little volume, low consumption and low cost. The standard BTCU models are developed and qualified with a configuration dedicated to ATC, while the first flight model will fly on MICROSCOPE for PYRO actuations and analogue acquisitions. The design of the BTCU is made in order to be easily adaptable for all type of electric interface needs.Extension of this concept is envisaged for power conditioning and distribution unit, and a Modular PCDU based on BRIO concept is proposed.

  4. Sustainability evaluation of decentralized electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Karger, Cornelia R.; Hennings, Wilfried [Research Centre Juelich, Programme Group Humans, Environment, Technology (MUT), 52425 Juelich (Germany)

    2009-04-15

    Decentralized power generation is gaining significance in liberalized electricity markets. An increasing decentralization of power supply is expected to make a particular contribution to climate protection. This article investigates the advantages and disadvantages of decentralized electricity generation according to the overall concept of sustainable development. On the basis of a hierarchically structured set of sustainability criteria, four future scenarios for Germany are assessed, all of which describe different concepts of electricity supply in the context of the corresponding social and economic developments. The scenarios are developed in an explorative way according to the scenario method and the sustainability criteria are established by a discursive method with societal actors. The evaluation is carried out by scientific experts. By applying an expanded analytic hierarchy process (AHP), a multicriteria evaluation is conducted that identifies dissent among the experts. The results demonstrate that decentralized electricity generation can contribute to climate protection. The extent to which it simultaneously guarantees security of supply is still a matter of controversy. However, experts agree that technical and economic boundary conditions are of major importance in this field. In the final section, the article discusses the method employed here as well as implications for future decentralized energy supply. (author)

  5. Convergent Double Auction Mechanism for a Prosumers' Decentralized Smart Grid

    National Research Council Canada - National Science Library

    Tadahiro Taniguchi; Tomohiro Takata; Yoshiro Fukui; Koki Kawasaki

    2015-01-01

    ...) for a prosumers' decentralized smart grid. The target decentralized smart grid is a regional electricity network that consists of many prosumers that have a battery and a renewable energy-based generator, such as photovoltaic cells...

  6. Transition-Independent Decentralized Markov Decision Processes

    Science.gov (United States)

    Becker, Raphen; Silberstein, Shlomo; Lesser, Victor; Goldman, Claudia V.; Morris, Robert (Technical Monitor)

    2003-01-01

    There has been substantial progress with formal models for sequential decision making by individual agents using the Markov decision process (MDP). However, similar treatment of multi-agent systems is lacking. A recent complexity result, showing that solving decentralized MDPs is NEXP-hard, provides a partial explanation. To overcome this complexity barrier, we identify a general class of transition-independent decentralized MDPs that is widely applicable. The class consists of independent collaborating agents that are tied up by a global reward function that depends on both of their histories. We present a novel algorithm for solving this class of problems and examine its properties. The result is the first effective technique to solve optimally a class of decentralized MDPs. This lays the foundation for further work in this area on both exact and approximate solutions.

  7. Partially decentralized control for ALSTOM gasifier.

    Science.gov (United States)

    Tan, Wen; Lou, Guannan; Liang, Luping

    2011-07-01

    The gasifier plays a key role in the operation of the whole IGCC power plant. It is a typical multivariable control system with strict constraints on the inputs and outputs which makes it very difficult to control. This paper presents a partially decentralized controller design method based on the stabilizer idea. The method only requires identifying some closed-loop transfer functions and solving an H(∞) optimization problem. The final partially decentralized controller is easy to implement and test in practice. Two partially decentralized controllers are designed for the ALSTOM gasifier benchmark problem, and simulation results show that they both meet the design specifications. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Towards Automatic Decentralized Control Structure Selection

    DEFF Research Database (Denmark)

    for decentralized control is determined automatically, and the resulting decentralized control structure is automatically tuned using standard techniques. Dynamic simulation of the resulting process system gives immediate feedback to the process design engineer regarding practical operability of the process......A subtask in integration of design and control of chemical processes is the selection of a control structure. Automating the selection of the control structure enables sequential integration of process and controld esign. As soon as the process is specified or computed, a structure....... The control structure selection problem is formulated as a special MILP employing cost coefficients which are computed using Parseval's theorem combined with RGA and IMC concepts. This approach enables selection and tuning of large-scale plant-wide decentralized controllers through efficient combination...

  9. Elements for a Theory of Decentralized Governance

    Directory of Open Access Journals (Sweden)

    Cristian-Ion POPA

    2013-06-01

    Full Text Available This year the Romanian Government has triggered a wide-ranging political process in order to revise the existing Constitution and, in this context, an ambitious program of decentralization-regionalization of the Romanian state administration. The article proposes a brief critical analysis of these generous objectives of the Government, and the means of achieving them, using a part of the academic literature devoted to decentralized governance. The two main sections of the article will attempt to address, in turn, and as realistic as possible, (1 the potential advantages of decentralized governance, and (2 some risks of this type of government, as they are described in the relevant literature of public economy.

  10. Towards Automatic Decentralized Control Structure Selection

    DEFF Research Database (Denmark)

    Jørgensen, John Bagterp; Jørgensen, Sten Bay

    2000-01-01

    A subtask in integration of design and control of chemical processes is the selection of a control structure. Automating the selection of the control structure enables sequential integration of process and control design. As soon as the process is specified or computed, a structure...... for decentralized control is determined automatically, and the resulting decentralized control structure is automatically tuned using standard techniques. Dynamic simulation of the resulting process system gives immediate feedback to the process design engineer regarding practical operability of the process....... The control structure selection problem is formulated as a special MILP employing cost coefficients which are computed using Parseval's theorem combined with RGA and IMC concepts. This approach enables selection and tuning of large-scale plant-wide decentralized controllers through efficient combination...

  11. Sub-100 nm hard X-ray microbeam generation with Fresnel zone plate optics

    CERN Document Server

    Takano, H; Takeuchi, A

    2003-01-01

    A hard X-ray focusing test of a Fresnel zone plate has been performed with a synchrotron radiation source at the undulator beamline 20XU of SPring-8. Fresnel zone plate with a radius of 150 mu m, and an outermost zone width of 100 nm was used for the X-ray focusing device. The 248-m-long beamline provides fully coherent illumination for the focusing device. The focused beam evaluated by the knife-edge-scan method and scanning microscope test using test charts. Nearly diffraction- limited focusing with a size of 120 nm was achieved for the first-order diffraction at 10 keV X-ray. Evaluation for the third order diffraction was also performed at 8 keV X-ray, and a focal size of 50 m has been obtained. (author)

  12. Fiscal decentralization and its effects on macroeconomic performance

    OpenAIRE

    Yalım, Derya

    2003-01-01

    Cataloged from PDF version of article. Decentralization has become an important policy issue in recent years. International organizations allocate more space for fiscal decentralization in their agenda. In the literature, there are vast amount of studies that concentrate on the advantages or disadvantages of fiscal decentralization. The literature suggested that with a good policy design of the fiscal decentralization, especially developing countries might achieve desired ou...

  13. Decentralization of Government Agencies: What Does It Accomplish?

    Science.gov (United States)

    Yin, Robert K.

    1979-01-01

    Focuses on the decentralization of governmental agencies from the perspective of both municipal and federal experiences. The article first discusses the main lessons from municipal decentralization, then outlines the characteristics of recent federal initiatives, and concludes with comments on the likely effects of decentralization. (Author)

  14. Harsh Realities about Decentralized Decision Making.

    Science.gov (United States)

    Patterson, Jerry

    1998-01-01

    To increase their odds for successful decentralized decision making, leaders must operate from a different set of realities about organizational change and design appropriate strategies to create more resilient organizations. Most people act first in their own self-interest; resist understanding the meaning of organizational change; and are…

  15. Decentralized forest governance in central Vietnam

    NARCIS (Netherlands)

    Tran Nam, T.; Burgers, P.P.M.

    2012-01-01

    A major challenge in decentralized forest governance in Vietnam is developing a mechanism that would support both reforestation and poverty reduction among people in rural communities. To help address this challenge, Forest Land Allocation (FLA) policies recognize local communities and individuals a

  16. Towards a Decentralized Magnetic Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Zakaria Kasmi

    2015-12-01

    Full Text Available Decentralized magnetic indoor localization is a sophisticated method for processing sampled magnetic data directly on a mobile station (MS, thereby decreasing or even avoiding the need for communication with the base station. In contrast to central-oriented positioning systems, which transmit raw data to a base station, decentralized indoor localization pushes application-level knowledge into the MS. A decentralized position solution has thus a strong feasibility to increase energy efficiency and to prolong the lifetime of the MS. In this article, we present a complete architecture and an implementation for a decentralized positioning system. Furthermore, we introduce a technique for the synchronization of the observed magnetic field on the MS with the artificially-generated magnetic field from the coils. Based on real-time clocks (RTCs and a preemptive operating system, this method allows a stand-alone control of the coils and a proper assignment of the measured magnetic fields on the MS. A stand-alone control and synchronization of the coils and the MS have an exceptional potential to implement a positioning system without the need for wired or wireless communication and enable a deployment of applications for rescue scenarios, like localization of miners or firefighters.

  17. GDCluster: A General Decentralized Clustering Algorithm

    NARCIS (Netherlands)

    Mashayekhi, Hoda; Habibi, Jafar; Khalafbeigi, Tania; Voulgaris, Spyros; van Steen, Martinus Richardus

    In many popular applications like peer-to-peer systems, large amounts of data are distributed among multiple sources. Analysis of this data and identifying clusters is challenging due to processing, storage, and transmission costs. In this paper, we propose GDCluster, a general fully decentralized

  18. Securing data accountability in decentralized systems

    NARCIS (Netherlands)

    Corin, Ricardo; Galindo, David; Hoepman, Jaap-Henk

    2006-01-01

    We consider a decentralized setting in which agents exchange data along with usage policies. Agents may violate the intended usage policies, although later on auditing authorities may verify the agents’ data accountability with respect to the intended policies. Using timestamping and signature schem

  19. Afterword: The Politics of School Decentralization

    Science.gov (United States)

    Peterson, Paul E.

    1975-01-01

    Summarizes the organizational process and political bargaining models of policy change, and considers the rational decision-making model as an alternative. Models are interrelated with each other to show how each reveals a dimension of the politics of school decentralization. (Author/AM)

  20. Decentralization and the local development state

    DEFF Research Database (Denmark)

    Emmenegger, Rony Hugo

    2016-01-01

    between the 2005 and 2010 elections. Based on ethnographic field research, the empirical case presented discloses that decentralization and state-led development serve the expansion of state power into rural areas, but that state authority is simultaneously constituted and undermined in the course...

  1. Fiscal decentralization and the challenges of public ecological services delivery

    Directory of Open Access Journals (Sweden)

    N.V. Kotenko

    2015-06-01

    provides for the official consolidation of local authorities which meets lots of resistance from communities. To overcome obstacles and make it really voluntary there are propositions to account natural marks and distributive criteria basing on ecosystem approach. The analysis of financial autonomy of local budgets shows that the prior part of local public revenues continues to form by intergovernmental fiscal transfers. For the purpose to provide sustainable development of communities authors propose to include ecological components into the system of budget equalization and compensation. This paper proves the inadequacy of horizontal equalization procedures for management of the system of general territorial nature use. The main reason for it is the inferior fiscal potential of the state environment tax and payments fixed attached to the local budgets. On the contrary, establishment of the ecological subsidies to the budget management allows to finance the local projects of expanded reproduction of territory and its ecological infrastructure. To resolve this problem authors propose to assess the quantity of ecological subsidy basing on the next parameters: the amount of population of rated community (political unit; the financial standard of budgetary provision of ecological services, compensate coefficients. The compensate coefficients must be individual to particular territory and take into account the ecological degradation pace, the efficiency and experience of ecological public program implementation, the tendency of degradation of independent nature components that is in keeping with existent levels of man's impact, the particularity of ecological service provisioning in exclusion zone. Conclusions and directions of further researches. To summarize, reform of fiscal decentralization in Ukraine is really needed and has opportunities. But it needs prudence and accurate economic ground. Cooperation and consolidation of communities on the basis of common interests and

  2. X-ray imaging microscopy at 25 keV with Fresnel zone plate optics

    CERN Document Server

    Awaji, M; Takeuchi, A; Takano, H; Kamijo, N; Tamura, S; Yasumoto, M

    2001-01-01

    X-ray imaging microscopy with a sputtered-sliced Fresnel zone plate (SS-FZP) has been developed at an X-ray energy of 25 keV. Objects were imaged in transmission with the SS-FZP as an objective with a magnification of 10.2 times, and detected with a X-ray image sensor. The performance of the imaging microscope has been tested with a gold mesh and a resolution test pattern at an undulator beamline 47XU of SPring-8. The resolution test patterns up to 0.5 mu m line-and-space structures have been resolved.

  3. In-the-bag decentration of an intraocular lens in a patient with a tendency to hypertrophic scarring

    Science.gov (United States)

    Joshi, Rajesh Subhash

    2016-01-01

    Summary We report a case of rapid anterior lens capsular contraction leading to decentration of a hydrophilic acrylic lens with stiff haptics (Rayner design). To our knowledge, this is the first report to investigate early capsular contraction with folding of the haptic over the optic in a patient with a tendency toward hypertrophic scar formation. PMID:27330480

  4. The impact of the semiconductor emitting diode brightness distribution on the energy sensitivity of the opto-electronic system with the optical equisignal zone

    Science.gov (United States)

    Nekrylov, Ivan S.; Timofeev, Alexander N.; Kleshchenok, Maksim A.

    2016-04-01

    The research of the influence of the LED radiation brightness distribution on the energy sensitivity of optical-electronic systems with optical equal zone is provided. Mathematical modeling of the radiation field on a matrix receiver, considering lens spherical aberration, is provided. The possibility of forming a uniform illumination on the photo-detector matrix, changing the shape of the distribution of the brightness of the LED at a predetermined invariable spherical aberration of the lens is provided.

  5. (DeCentralization of the Global Informational Ecosystem

    Directory of Open Access Journals (Sweden)

    Johanna Möller

    2017-09-01

    Full Text Available Centralization and decentralization are key concepts in debates that focus on the (antidemocratic character of digital societies. Centralization is understood as the control over communication and data flows, and decentralization as giving it (back to users. Communication and media research focuses on centralization put forward by dominant digital media platforms, such as Facebook and Google, and governments. Decentralization is investigated regarding its potential in civil society, i.e., hacktivism, (encryption technologies, and grass-root technology movements. As content-based media companies increasingly engage with technology, they move into the focus of critical media studies. Moreover, as formerly nationally oriented companies now compete with global media platforms, they share several interests with civil society decentralization agents. Based on 26 qualitative interviews with leading media managers, we investigate (decentralization strategies applied by content-oriented media companies. Theoretically, this perspective on media companies as agents of (decentralization expands (decentralization research beyond traditional democratic stakeholders by considering economic actors within the “global informational ecosystem” (Birkinbine, Gómez, & Wasko, 2017. We provide a three-dimensional framework to empirically investigate (decentralization. From critical media studies, we borrow the (decentralization of data and infrastructures, from media business research, the (decentralization of content distribution.

  6. Partially coherent sources which produce the same far zone optical force as a laser beam

    CERN Document Server

    Auñon, Juan Miguel

    2013-01-01

    On applying a theorem previously derived by Wolf and Collett, we demonstrate that partially coherent Gaussian Schell model uctuating sources (GSMS) produce exactly the same optical forces as a fully coherent laser beam. We also show that this kind of sources helps to control the light-matter interaction in biological samples which are very sensitive to thermal heating induced by higher power intensities; and hence the invasiveness of the manipulation. This is a consequence of the fact that the same photonic force can be obtained with a low intensity GSMS as with a high intensity laser beam.

  7. Management Methods of Decentralized Public Services

    Directory of Open Access Journals (Sweden)

    BILOUSEAC Irina Adriana

    2013-05-01

    Full Text Available The purpose of the article, having as theme the typology of public services management and the implications on decentralization, is the foundation of theoretical concepts, but also the analysis from a practical point of view of both types of management applied in the management of public services in Romania and of the effects they cause on the Romanian public administration capacity to provide efficient public services. Although the users of decentralized public services don’t have the possibility of choosing the service provider, the analysis of the management methods is important, because depending on the type of management chosen there are advantages and disadvantages for the local community. It has to be analyzed for each particularly case which type of management leads to a greater satisfaction of a social need appeared.

  8. Centralized, Decentralized, and Hybrid Purchasing Organizations

    DEFF Research Database (Denmark)

    Bals, Lydia; Turkulainen, Virpi

    illustrate with our empirical analysis on global sourcing organization design at Global Chemical Company (GCC, a pseudonym) that revisiting the conventional wisdom about global sourcing organization designs is required; by engaging in a detailed, subfirm level of analysis on the design of the purchasing......This paper addresses one of the focal issues in purchasing and supply management – global sourcing – from an organizational design perspective. In particular, we elaborate the traditional classification of global sourcing organization designs into centralized, decentralized, and hybrid models. We...... organization we can identify organization designs beyond the classical centralization-decentralization continuum. We also provide explanations for the observed organization design at GCC. The study contributes to research on purchasing and supply management as well as research on organization design....

  9. Problems in Decentralized Decision making and Computation.

    Science.gov (United States)

    1984-12-01

    Wald ) problem [Teneketzis, 1983], as well as problems involving communication of zero-one messages from certain sensors to others [Ekchian and Tenney...that the development of results for pseudo-gradient algorithms leads easily to results for broader classes of algorithms, such as Kiefer- Wolfowitz ...Decentralized Wald Problem," Proceedings of the 1983 American Control Conference, San Francisco, CA. Teneketzis, D., P. Varaiya, (1984), "Consensus in

  10. Centralization Versus Decentralization in Credit Lending

    OpenAIRE

    Idriss Ghodbane, Mohamed

    2002-01-01

    This paper explores different organizational forms in terms of their ability to generate information about investment projects and allocate capital to these projects efficiently. A decentralized approach - with small, single-manager firms - is most likely to be attractive when information about individual projects is "non-verifiable" and cannot be credibly trasmitted. Moreover, holding fixed firm size, non-verifiable information also favors flatter organizations with fewer layers of manage...

  11. Fiscal Decentralization and Soft Budget Constraints

    OpenAIRE

    Timofeev Andrey

    2002-01-01

    Liberalization policies of transition have led to the mass reduction of enterprise subsidization which prevailed in socialist economies. However, in some sectors of the economy, subsidies associated with price controls remain due to "social" and "political" factors. Moreover in multi-tier governments, subnational levels seem to be more sensitive to these factors because of their proximity to the constituency. Thus decentralization of fiscal resources might interfere with the elimination of re...

  12. Rural Roads: The Challenge of Decentralized Implementation

    OpenAIRE

    Simon D. Ellis; Aurelio Menendez

    2014-01-01

    This paper will review the key elements required for effective decentralized implementation of rural roads programs. It will review the range of options available and the evidence for successful implementation where it exists. Section 2 makes the case for the importance of rural roads and sets out the evidence for the socio-economic benefits. Section 3 addresses the responsibilities for implementation and critical importance of having clarity over network ownership. Section 4 highlights the d...

  13. Model for valuating decentralized energy production

    OpenAIRE

    Cider, Muammer

    2008-01-01

    Ankara : The Department of Economics, Bilkent University, 2008. Thesis (Master's) -- Bilkent University, 2008. Includes bibliographical references leaves 78-79. The purpose of this thesis is to assess decentralized production technologies in an economical framework. Throughout the thesis, technological aspects such as smart metering or connectivity issues are ignored. All assumptions are based on specification sheets by the producers of the technologies to provide an imparti...

  14. File Transfer Algorithm for Autonomous Decentralized System

    Institute of Scientific and Technical Information of China (English)

    GUI Xun; TAN Yong-dong; Qian Qing-quan

    2008-01-01

    A file transfer algorithm based on ADP (autonomous decentralized protocol) was proposed to solve the problem that the ADS (autonomous decentralized system) middleware (NeXUS/Dlink) lacks of file transfer functions for Windows. The algorithm realizes the peer-to-peer file transfer, one-to-N inquiry/multi-response file transfer and one-to-N file distribution in the same data field based on communication patterns provided by the ADP. The peer-to-peer file transfer is implemented through a peer-to-peer communication path, one-to-N inquiry/multi-response file transfer and one-to-N file distribution are implemented through multicast commtmieation. In this algorithm, a file to be transferred is named with a GUID ( global unique identification), every data packet is marked with a sequence number, and file-receiving in parallel is implemented by caching DPOs (data processing objects) and multithread technologies. The algorithm is applied in a simulation system of the decentralized control platform, and the test results and long time stable mrming prove the feasibility of the algorithm.

  15. Query Optimizations over Decentralized RDF Graphs

    KAUST Repository

    Abdelaziz, Ibrahim

    2017-05-18

    Applications in life sciences, decentralized social networks, Internet of Things, and statistical linked dataspaces integrate data from multiple decentralized RDF graphs via SPARQL queries. Several approaches have been proposed to optimize query processing over a small number of heterogeneous data sources by utilizing schema information. In the case of schema similarity and interlinks among sources, these approaches cause unnecessary data retrieval and communication, leading to poor scalability and response time. This paper addresses these limitations and presents Lusail, a system for scalable and efficient SPARQL query processing over decentralized graphs. Lusail achieves scalability and low query response time through various optimizations at compile and run times. At compile time, we use a novel locality-aware query decomposition technique that maximizes the number of query triple patterns sent together to a source based on the actual location of the instances satisfying these triple patterns. At run time, we use selectivity-awareness and parallel query execution to reduce network latency and to increase parallelism by delaying the execution of subqueries expected to return large results. We evaluate Lusail using real and synthetic benchmarks, with data sizes up to billions of triples on an in-house cluster and a public cloud. We show that Lusail outperforms state-of-the-art systems by orders of magnitude in terms of scalability and response time.

  16. Dynamic Teams and Decentralized Control Problems with Substitutable Actions

    OpenAIRE

    Asghari, Seyed Mohammad; Nayyar, Ashutosh

    2016-01-01

    This paper considers two problems -- a dynamic team problem and a decentralized control problem. The problems we consider do not belong to the known classes of "simpler" dynamic team/decentralized control problems such as partially nested or quadratically invariant problems. However, we show that our problems admit simple solutions under an assumption referred to as the substitutability assumption. Intuitively, substitutability in a team (resp. decentralized control) problem means that the ef...

  17. Political decentralization and corruption: Evidence from around the world

    OpenAIRE

    Fan, CS; Lin, C.; Treisman, D

    2009-01-01

    How does political decentralization affect the frequency and costliness of bribe extraction by corrupt officials? Previous empirical studies, using subjective indexes of perceived corruption and mostly fiscal indicators of decentralization, have suggested conflicting conclusions. In search of more precise findings, we combine and explore two new data sources—an original cross-national data set on particular types of decentralization and the results of a firm level survey conducted in 80 count...

  18. Decentralized Energy Studies: compendium of U. S. studies and projects

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, J.; Ohi, J.M.

    1980-06-01

    This compendium was prepared as a part of the Decentralized Energy Studies task at the Solar Energy Research Institute. The compendium lists and briefly describes a number of studies, programs, and projects that involve decentralized energy systems. The purpose is to provide information about research activities in decentralized energy systems to researchers, government officials, and interested citizens. A contact person or address is given for each of the activities listed so that interested readers can obtain more information.

  19. Dissolved oxygen concentration profiles in the hyporheic zone through the use of a high density fiber optic measurement network

    Science.gov (United States)

    Reeder, W. J.; Quick, A. M.; Farrell, T. B.; Benner, S. G.; Feris, K. P.; Tonina, D.

    2013-12-01

    The hyporheic zone (HZ) is a potentially important source of the potent greenhouse gas, nitrous oxide (N2O); stream processes may account for up to 10% of global anthropogenic N2O emissions. However, mechanistic understanding and predictive quantification of this gas flux is hampered by complex temporally and spatially variable interactions between flow dynamics and biogeochemical processes. Reactive inorganic nitrogen (Nr) is typically present at low concentrations in natural stream waters, but many rural and urban streams suffer from an excess of Nr, typically in the form of ammonium (NH4+) and nitrate (NO3-). These reactive species are either assimilated by living biomass or transformed by microbial processes. The two primary microbial transformations of Nr are nitrification (NH4+ to NO3-) and denitrification (NO3- to N2). Denitrification, which occurs almost exclusively in the anoxic zone of the HZ, permanently removes between 30-70% of all Nr entering streams, other mechanisms may retain nitrogen. The mass transport of reactive species (i.e. O2, NO3- and N2O) by hyporheic flow strongly influences reaction rates, residence times, and subsequent N2O flux. By extension, stream flow and channel morphology presumably control, and may be effective predictors of, N2O generation rates. By recreating the stream processes in the University of Idaho flume, we are able to control the bed morphology, fluxes and residence times through the HZ and concentrations of Nr from exogenous (stream water) and endogenous (organic material in the streambed) sources. For the present experiment, the flume was divided into three streams, each with different morphologies (3, 6 and 9cm dunes) and all using the same source water. Stream water for this first experimental phase had no significant loading of Nr. As such, all reaction products were the result of endogenous sources of Nr. To measure dissolved oxygen (DO) concentrations we deployed 120 channels of a novel, fiber-optic optode

  20. Design of Solar Optical Fiber Lighting System for Enhanced Lighting in Highway Tunnel Threshold Zone: A Case Study of Huashuyan Tunnel in China

    Directory of Open Access Journals (Sweden)

    Xiaochun Qin

    2015-01-01

    Full Text Available In this paper, the principle, structural composition, materials, and characteristics of solar optical fiber lighting system were discussed. The different luminance requirements of different zones of highway tunnel were identified on the basis of the analysis of tunnel lighting considering drivers’ visually self-accommodating physiological function for luminance change. Taken Huashuyan Tunnel of G109 Highway located in Hohhot of Inner Mongolia in China as the case study, the system design of solar optical fiber lighting for enhanced lighting in threshold zone of highway tunnel was made. It was indicated through calculation that the design length of solar optical fiber enhanced lighting was related to the design speed, longitudinal slope, and overhead clearance of the tunnel, and the design luminance of solar optical fiber enhanced lighting was related to the luminance outside the tunnel, the design speed, and the design traffic flow of the tunnel. Luminance analysis of the solar optical fiber lighting system of Huashuyan Tunnel was made based on the on-site experiment. Also, the 3D illuminance simulation results by DIALux software were made to indicate that the solar optical fiber lighting system in Huashuyan Tunnel still well met the enhanced lighting demand even not considering the contribution of LED lighting.

  1. Tractable problems in optimal decentralized control

    Science.gov (United States)

    Rotkowitz, Michael Charles

    2005-07-01

    This thesis considers the problem of constructing optimal decentralized controllers. The problem is formulated as one of minimizing the closed-loop norm of a feedback system subject to constraints on the controller structure. The notion of quadratic invariance of a constraint set with respect to a system is defined. It is shown that quadratic invariance is necessary and sufficient for the constraint set to be preserved under feedback. It is further shown that if the constraint set has this property, this allows the constrained minimum-norm problem to be solved via convex programming. These results are developed in a very general framework, and are shown to hold for continuous-time systems, discrete-time systems, or operators on Banach spaces, for stable or unstable plants, and for the minimization of any norm. The utility of these results is then demonstrated on some specific constraint classes. An explicit test is derived for sparsity constraints on a controller to be quadratically invariant, and thus amenable to convex synthesis. Symmetric synthesis is also shown to be quadratically invariant. The problem of control over networks with delays is then addressed as another constraint class. Multiple subsystems are considered, each with its own controller, such that the dynamics of each subsystem may affect those of other subsystems with some propagation delays, and the controllers may communicate with each other with some transmission delays. It is shown that if the communication delays are less than the propagation delays, then the associated constraints are quadratically invariant, and thus optimal controllers can be synthesized. We further show that this result still holds in the presence of computational delays. This thesis unifies the few previous results on specific tractable decentralized control problems, identifies broad and useful classes of new solvable problems, and delineates the largest known class of convex problems in decentralized control.

  2. A Novel Scheme of Fast-frequency Hopping Optical CDMA System with No-hit-zone Sequence

    Science.gov (United States)

    Ji, Jianhua; liu, Ling; Wang, Ke; Zhang, Zhipeng; Xu, Ming

    2013-09-01

    In traditional fast frequency-hopping OCDMA (FFH-OCDMA) system, beat noise and multiple-access interference are the main performance limitations, and complicated power control must be employed to eliminate the near-far effect. In this paper, a novel scheme of FFH-OCDMA with no-hit-zone sequence is proposed, which is named NHZ FFH-OCDMA. In NHZ FFH-OCDMA, the synchronization among users can be controlled within permissible time delay, and the code cross-correlation for different users equals zero. Therefore, near-far effect can be eliminated. Furthermore, beat noise and multiple-access interference also can be removed. Simulation of eight simultaneous users with dada rate 100 Mbit/s is demonstrated, where the fiber link consists of 50 km single-mode fiber, plus 5 km dispersion compensating fiber. Simulation results show that the near-far problem of NHZ FFH-OCDMA can be eliminated, and complicated power control can be removed. Therefore, this scheme is a good candidate for optical access network.

  3. Decentralized Pricing in Minimum Cost Spanning Trees

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moulin, Hervé; Østerdal, Lars Peter

    In the minimum cost spanning tree model we consider decentralized pricing rules, i.e. rules that cover at least the ecient cost while the price charged to each user only depends upon his own connection costs. We de ne a canonical pricing rule and provide two axiomatic characterizations. First......, the canonical pricing rule is the smallest among those that improve upon the Stand Alone bound, and are either superadditive or piece-wise linear in connection costs. Our second, direct characterization relies on two simple properties highlighting the special role of the source cost....

  4. Decentralized Coordinated Control Strategy of Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan

    as grid voltage/frequency regulation. In order to enhance the reliability of overall islanded Microgrid operation, basic functions of coordinated control which taking into account the state of charge (SoC) limitation and power availability of renewable energy sources is implemented in a distributed level...... control strategies in this thesis, in order to promote the decentralization of the overall system. Especially the consensus algorithm based secondary level is investigated in the thesis in order to simplify the communication configuration which only flood information through the neighboring units...

  5. P2P Techniques for Decentralized Applications

    CERN Document Server

    Pacitti, Esther

    2012-01-01

    As an alternative to traditional client-server systems, Peer-to-Peer (P2P) systems provide major advantages in terms of scalability, autonomy and dynamic behavior of peers, and decentralization of control. Thus, they are well suited for large-scale data sharing in distributed environments. Most of the existing P2P approaches for data sharing rely on either structured networks (e.g., DHTs) for efficient indexing, or unstructured networks for ease of deployment, or some combination. However, these approaches have some limitations, such as lack of freedom for data placement in DHTs, and high late

  6. Assessment of β-zone peripapillary atrophy by optical coherence tomography and scanning laser ophthalmoscopy imaging in glaucoma patients

    Directory of Open Access Journals (Sweden)

    Seidensticker F

    2014-06-01

    Full Text Available Florian Seidensticker,1,* Lukas Reznicek,2,* Thomas Mann,2 Irene Hübert,2 Anselm Kampik,2 Michael Ulbig,2 Christoph Hirneiss,2 Aljoscha S Neubauer,2 Marcus Kernt2 1Department of Ophthalmology, Hannover Medical School, Hannover, Germany; 2Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany  *These authors have contributed equally to this work Purpose: To assess β-zone peripapillary atrophy (β-PPA using spectral domain optical coherence tomography (SD-OCT, scanning laser ophthalmoscopy (SLO, and fundus autofluorescence (FAF imaging in patients with primary open-angle glaucoma with advanced glaucomatous visual field defects. Methods: A consecutive, prospective series of 82 study eyes with primary open-angle glaucoma were included in this study. All study participants underwent a full ophthalmic examination followed by SD-OCT, wide-field SLO, and FAF imaging of the optic nerve head and the peripapillary region. Results: Eighty-four glaucomatous eyes were included in our prospective study. Correlation analyses for horizontally and vertically obtained β-PPA for all three imaging modalities (color SLO, FAF, and SD-OCT revealed highest correlations between FAF and color SLO (Pearson correlation coefficient: 0.904 [P<0.001] for horizontal β-PPA and 0.786 [P<0.001] for vertical β-PPA. Bland–Altman plotting revealed highest agreements between color SLO and FAF, with −2.1 pixels ±1.96 standard deviation (SD for horizontal β-PPA, SD: 10.5 pixels and 2.4 pixels ±1.96 SD for vertical β-PPA. Conclusion: β-PPA can be assessed using en-face SLO and cross-sectional SD-OCT imaging. Correlation analyses revealed highest correlations between color SLO and FAF imaging, while correlations between SLO and SD-OCT were weak. A more precise structural definition of β-PPA is needed. Keywords: fundus autofluorescence, FAF, OCT, SD-OCT, SLO, glaucomatous optic neuropathy

  7. Providing leadership to a decentralized total quality process.

    Science.gov (United States)

    Diederich, J J; Eisenberg, M

    1993-01-01

    Integrating total quality management into the culture of an organization and the daily work of employees requires a decentralized leadership structure that encourages all employees to become involved. This article, based upon the experience of the University of Michigan Hospitals Professional Services Divisional Lead Team, outlines a process for decentralizing the total quality management process.

  8. Decentralized energy studies: compendium of international studies and research

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, C.

    1980-03-01

    The purpose of the compendium is to provide information about research activities in decentralized energy systems to researchers, government officials, and interested citizens. The compendium lists and briefly describes a number of studies in other industrialized nations that involve decentralized energy systems. A contact person is given for each of the activities listed so that interested readers can obtain more information.

  9. School Administration: Optimal Ratio of Centralization to Decentralization.

    Science.gov (United States)

    Kapto, A. E.

    1990-01-01

    Compares advantages and disadvantages of centralized and decentralized control in Soviet public schools. Recognizes that centralization concentrates the forces, funds, and available resources necessary for maximum achievement. Suggests that decentralization of administration can be optimized by delegating rights, duties, and responsibilities to…

  10. Microflora of drinking water distributed through decentralized supply systems (Tomsk)

    Science.gov (United States)

    Khvaschevskaya, A. A.; Nalivaiko, N. G.; Shestakova, A. V.

    2016-03-01

    The paper considers microbiological quality of waters from decentralized water supply systems in Tomsk. It has been proved that there are numerous microbial contaminants of different types. The authors claim that the water distributed through decentralized supply systems is not safe to drink without preliminary treatment.

  11. Study on Concept of Centralization and Decentralization Group Decision Making

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qin-sheng; XI You-min; WANG Ying-luo

    2002-01-01

    The paper extracts the concept of Centralization Group Decision Making (CGDM) and Decentralization Group Decision Making (DGDM) from management systems on bases of studies on Informational Centralization Process (ICP) and Informational Decentralization Process (IDP), then the similarities and differences between CGDM and DGDM are presented. Further, the taxonomy of CGDM and DGDM is researched.

  12. An index of political support for decentralization: the Spanish case.

    OpenAIRE

    2010-01-01

    This paper presents a method to make measurable what was not: the discourses of politicians regarding decentralization. For this purpose, we develop a matrix of arguments and a set of indexes, and apply them to provide a snapshot of the politicians views on the General Law of Budgetary Stability, a landmark for the process of decentralization in Spain.

  13. Setting the Governmental Agenda for State Decentralization of Higher Education.

    Science.gov (United States)

    McLendon, Michael K.

    2003-01-01

    State decentralization of higher education emerged as a significant governance trend of the 1980s to 1990s. Yet little is known about how or why decentralization first became an issue to which state governments paid serious attention. This study employs multiple theories to analyze the agenda-setting stage of policy formation in three states…

  14. Decentralized Consistency Checking in Cross-organizational Workflows

    NARCIS (Netherlands)

    Wombacher, Andreas

    Service Oriented Architectures facilitate loosely coupled composed services, which are established in a decentralized way. One challenge for such composed services is to guarantee consistency, i.e., deadlock-freeness. This paper presents a decentralized approach to consistency checking, which

  15. Decentralized Event-triggered Control with Asynchronous Updates

    NARCIS (Netherlands)

    Mazo Jr., Manuel; Cao, Ming

    2011-01-01

    We propose taking event-triggered control actions to implement decentralized control over wireless sensor/actuator networks without requiring synchronized measurement updates. In comparison with the existing results on event-triggered decentralized control, the proposed implementation does not rely

  16. Decentralized Consistency Checking in Cross-organizational Workflows

    NARCIS (Netherlands)

    Wombacher, A.

    2006-01-01

    Service Oriented Architectures facilitate loosely coupled composed services, which are established in a decentralized way. One challenge for such composed services is to guarantee consistency, i.e., deadlock-freeness. This paper presents a decentralized approach to consistency checking, which utiliz

  17. Centralization Versus Decentralization: A Location Analysis Approach for Librarians.

    Science.gov (United States)

    Shishko, Robert; Raffel, Jeffrey

    One of the questions that seems to perplex many university and special librarians is whether to move in the direction of centralizing or decentralizing the library's collections and facilities. Presented is a theoretical approach, employing location theory, to the library centralization-decentralization question. Location theory allows the analyst…

  18. Centralization vs. Decentralization: A Location Analysis Approach for Librarians

    Science.gov (United States)

    Raffel, Jeffrey; Shishko, Robert

    1972-01-01

    An application of location theory to the question of centralized versus decentralized library facilities for a university, with relevance for special libraries is presented. The analysis provides models for a single library, for two or more libraries, or for decentralized facilities. (6 references) (Author/NH)

  19. Analysis of Schwalbe′s Line (Limbal Smooth Zone by Scanning Electron Microscopy and Optical Coherence Tomography in Human Eye Bank Eyes

    Directory of Open Access Journals (Sweden)

    Mark P Breazzano

    2013-01-01

    Full Text Available Purpose: Implantation of intraocular devices may become critical as they decrease in size in the future. Therefore, it is desirable to evaluate the relationship between radial location and Schwalbe′s line (smooth zone by examining its width with scanning electron microscopy (SEM and to correlate this with observations by optical coherence tomography (OCT. Methods: Full corneoscleral rings were obtained from twenty-six formalin-fixed human phakic donor eyes. SEM of each eye yielded a complete montage of the smooth zone, from which the area was measured, and width was determined in each quadrant. In three different eyes, time domain anterior segment OCT (Visante, Carl Zeiss Meditec Inc., Dublin, CA, USA and spectral domain OCT (Cirrus 4.0, Carl Zeiss Meditec Inc., Dublin, CA, USA were used to further characterize Schwalbe′s line. Results: The overall smooth zone width was 79±22 μm, (n=15 ranging from 43 to 115 μm. The superior quadrant (103±8 μm, n=19, demonstrated significantly wider smooth zone than both the nasal (71±5 μm, n=19, P0.05. SEM findings of the smooth zone were correlated with visualization of Schwalbe′s line by Cirrus and Visante OCT imaging. Conclusion: The smooth zone appears widest superiorly and thinnest inferonasally, suggesting that as glaucoma surgical devices become smaller, their placement could be targeted clinically by using OCT with preference to the superior quadrant, to minimize damage to the corneal endothelium.

  20. Conceptualizing decentralization in European health systems: a functional perspective.

    Science.gov (United States)

    Saltman, Richard B; Bankauskaite, Vaida

    2006-04-01

    Although decentralization has been widely implemented in health systems, there is little agreement as to how it should be defined or the outcomes it should produce. This article develops a functional typology based on political, administrative, and fiscal dimensions of decentralization. It utilizes these three categories to identify and highlight key theoretical issues concerning decentralization, emphasizing the likely advantages and disadvantages that decentralization can be expected to generate. It then examines the usefulness of this functional framework in explaining recent policy-making decisions within a number of tax-based health systems in Western Europe. The article concludes by suggesting that this three-part typology can be helpful to both policy makers and academics in evaluating the effectiveness of decentralization as a policy mechanism within health care systems.

  1. Environmental systems and local actors: decentralizing environmental policy in Uganda.

    Science.gov (United States)

    Oosterveer, Peter; Van Vliet, Bas

    2010-02-01

    In Uganda, environmental and natural resource management is decentralized and has been the responsibility of local districts since 1996. This environmental management arrangement was part of a broader decentralization process and was intended to increase local ownership and improve environmental policy; however, its implementation has encountered several major challenges over the last decade. This article reviews some of the key structural problems facing decentralized environmental policy in this central African country and examines these issues within the wider framework of political decentralization. Tensions have arisen between technical staff and politicians, between various levels of governance, and between environmental and other policy domains. This review offers a critical reflection on the perspectives and limitations of decentralized environmental governance in Uganda. Our conclusions focus on the need to balance administrative staff and local politicians, the mainstreaming of local environmental policy, and the role of international donors.

  2. Decentralization and Participatory Rural Development: A Literature Review

    Directory of Open Access Journals (Sweden)

    Muhammad Shakil Ahmad

    2011-12-01

    Full Text Available Most of the developing nations are still struggling for efficient use of their resources. In order to overcome physical and administrative constraints of the development, it is necessary to transfer the power from the central government to local authorities. Distribution of power from improves the management of resources and community participation which is considered key to sustainable development. Advocates of decentralization argue that decentralized government is source to improve community participation in rural development. Decentralized government is considered more responsive towards local needs and development of poor peoples. There are many obstacles to expand the citizen participation in rural areas. There are many approaches for participatory development but all have to face the same challenges. Current paper highlights the literature about Decentralization and participatory rural development. Concept and modalities of Decentralization, dimensions of participation, types of rural participation and obstacles to participation are also the part of this paper.

  3. Decentralized control experiments on NASA's flexible grid

    Science.gov (United States)

    Ozguner, U.; Yurkowich, S.; Martin, J., III; Al-Abbass, F.

    1986-01-01

    Methods arising from the area of decentralized control are emerging for analysis and control synthesis for large flexible structures. In this paper the control strategy involves a decentralized model reference adaptive approach using a variable structure control. Local models are formulated based on desired damping and response time in a model-following scheme for various modal configurations. Variable structure controllers are then designed employing co-located angular rate and position feedback. In this scheme local control forces the system to move on a local sliding mode in some local error space. An important feature of this approach is that the local subsystem is made insensitive to dynamical interactions with other subsystems once the sliding surface is reached. Experiments based on the above have been performed for NASA's flexible grid experimental apparatus. The grid is designed to admit appreciable low-frequency structural dynamics, and allows for implementation of distributed computing components, inertial sensors, and actuation devices. A finite-element analysis of the grid provides the model for control system design and simulation; results of several simulations are reported on here, and a discussion of application experiments on the apparatus is presented.

  4. Batch Delivery Scheduling with Multiple Decentralized Manufacturers

    Directory of Open Access Journals (Sweden)

    Shi Li

    2014-01-01

    Full Text Available This paper addresses an integrated decision on production scheduling and delivery operations, which is one of the most important issues in supply chain scheduling. We study a model in which a set of jobs ordered by only one customer and a set of decentralized manufacturers located at different locations are considered. Specifically, each job must be assigned to one of the decentralized manufacturers to process on its single machine facility. Then, the job is delivered to the customer directly in batch without intermediate inventory. The objective is to find a joint schedule of production and distribution to optimize the customer service level and delivery cost. In our work, we discuss this problem considering two different situations in terms of the customer service level. In the first one, the customer service is measured by the maximum arrival time, while the customer service is measured by the total arrival time in the second one. For each situation, we develop a dynamic programming algorithm to solve, respectively. Moreover, we identify a special case for the latter situation by introducing its corresponding solutions.

  5. Decentralized asset management for collaborative sensing

    Science.gov (United States)

    Malhotra, Raj P.; Pribilski, Michael J.; Toole, Patrick A.; Agate, Craig

    2017-05-01

    There has been increased impetus to leverage Small Unmanned Aerial Systems (SUAS) for collaborative sensing applications in which many platforms work together to provide critical situation awareness in dynamic environments. Such applications require critical sensor observations to be made at the right place and time to facilitate the detection, tracking, and classification of ground-based objects. This further requires rapid response to real-world events and the balancing of multiple, competing mission objectives. In this context, human operators become overwhelmed with management of many platforms. Further, current automated planning paradigms tend to be centralized and don't scale up well to many collaborating platforms. We introduce a decentralized approach based upon information-theory and distributed fusion which enable us to scale up to large numbers of collaborating Small Unmanned Aerial Systems (SUAS) platforms. This is exercised against a military application involving the autonomous detection, tracking, and classification of critical mobile targets. We further show that, based upon monte-carlo simulation results, our decentralized approach out-performs more static management strategies employed by human operators and achieves similar results to a centralized approach while being scalable and robust to degradation of communication. Finally, we describe the limitations of our approach and future directions for our research.

  6. Centralized versus decentralized lunar PMAD study

    Science.gov (United States)

    Metcalf, Kenneth J.

    A study of proposed lunar base architectures was performed to identify issues concerning centralized and decentralized power system deployment options. The power management and distribution (PMAD) system analysis is addressed. The PMAD system consists of power conditioning components that convert the generated power into the form desired for transmission, transmission lines that conduct this power from the power sources to the loads, and power conditioning hardware that converts the power into the form selected for secondary distribution to the loads. Three PMAD architecture configurations were evaluated: centralized, hybrid, and decentralized. Two models were created for each architecture to identify the preferred method of power transmission, DC or AC. Each model permitted the load power demands and distribution voltage level to be varied to assess the impact on power system mass. The AC power system models also allowed the distribution frequency to be changed. Finally, individual models were developed for different transmission line configurations and placements to determine the best conductor construction and installation location.

  7. Issues concerning centralized versus decentralized power deployment

    Science.gov (United States)

    Metcalf, Kenneth J.; Harty, Richard B.; Robin, James F.

    1991-03-01

    The results of a study of proposed lunar base architectures to identify issues concerning centralized and decentralized power system deployment options are presented. The power system consists of the energy producing system (power plant), the power conditioning components used to convert the generated power into the form desired for transmission, the transmission lines that conduct this power from the power sources to the loads, and the primary power conditioning hardware located at the user end. Three power system architectures, centralized, hybrid, and decentralized, were evaluated during the course of this study. Candidate power sources were characterized with respect to mass and radiator area. Two electrical models were created for each architecture to identify the preferred method of power transmission, dc or ac. Each model allowed the transmission voltage level to be varied at assess the impact on power system mass. The ac power system models also permitted the transmission line configurations and placements to determine the best conductor construction and installation location. Key parameters used to evaluate each configuration were power source and power conditioning component efficiencies, masses, and radiator areas; transmission line masses and operating temperatures; and total system mass.

  8. IOL tilt and decentration estimation from 3 dimensional reconstruction of OCT image.

    Directory of Open Access Journals (Sweden)

    Xiaogang Wang

    Full Text Available PURPOSE: To evaluate intraocular lens (IOL tilt and decentration by anterior segment optical coherence tomography (AS-OCT using 3-dimensional (3D reconstruction method. DESIGN: Prospective observational case series. PARTICIPANTS: Thirty-nine patients (39 eyes were included. METHODS: The IOL positions of all eyes were examined by AS-OCT. Images were obtained in 4 axes (0-180 degrees, 45-225 degrees, 90-270 degrees, and 135-315 degrees using the quadrant-scan model. The cross-sectional images were analyzed with MATLAB software. MAIN OUTCOME MEASURES: The angle (θ between the reference pupillary plane and the IOL plane, the distances between the center points of the pupil circle and the IOL on the x-axis (dx and y-axis (dy and the spatial distance (ds were calculated after 3D-reconstruction. RESULTS: The mean angle (θ between the pupillary plane and the IOL plane was 2.94±0.99 degrees. The mean IOL decentration of dx and dy was 0.32±0.26 mm and 0.40±0.27 mm, respectively. The ds of the IOL decentration was 0.56±0.31 mm. There was no significant correlation between the ocular residual astigmatism (ORA and the tilted angle or the decentration distance. There was a significant correlation between the ORA and total astigmatism (r = 0.742, P<0.001. There was no significant correlation between the postoperative best corrected visual acuity (BCVA and the ORA (r = 0.156; P = 0.344, total astigmatism (r = 0.012; P = 0.942, tilted angle (θ; r = 0.172; P = 0.295 or decentration distance (dx: r = 0.191, P = 0.244; dy: r = 0.253, P = 0.121; ds: r = 0.298, P = 0.065. CONCLUSIONS: AS-OCT can be used as an alternative for the analysis of IOL tilt and decentration using 3D-reconstruction.

  9. Energy and air emission implications of a decentralized wastewater system

    Science.gov (United States)

    Shehabi, Arman; Stokes, Jennifer R.; Horvath, Arpad

    2012-06-01

    Both centralized and decentralized wastewater systems have distinct engineering, financial and societal benefits. This paper presents a framework for analyzing the environmental effects of decentralized wastewater systems and an evaluation of the environmental impacts associated with two currently operating systems in California, one centralized and one decentralized. A comparison of energy use, greenhouse gas emissions and criteria air pollutants from the systems shows that the scale economies of the centralized plant help lower the environmental burden to less than a fifth of that of the decentralized utility for the same volume treated. The energy and emission burdens of the decentralized plant are reduced when accounting for high-yield wastewater reuse if it supplants an energy-intensive water supply like a desalination one. The centralized facility also reduces greenhouse gases by flaring methane generated during the treatment process, while methane is directly emitted from the decentralized system. The results are compelling enough to indicate that the life-cycle environmental impacts of decentralized designs should be carefully evaluated as part of the design process.

  10. LOCAL BUDGETS UNDER CURRENT DECENTRALIZATION: UKRAINE AND FOREIGN EXPERIENCE

    Directory of Open Access Journals (Sweden)

    O. Cheberyako

    2016-04-01

    Full Text Available The article is devoted to the major trends and issues of development of local budgets in Ukraine. A study of the essence of fiscal decentralization as one of the components of the management, aimed at reducing the dependence of local governments from the central government with regard to foreign experience. Particular attention is paid to local budgets under decentralization of own and delegated financial powers. The theoretical principles of fiscal decentralization and its proven impact on the socio-economic development. Studied the European countries model of local budgets. The features of formation of revenues of local budgets under decentralization. The role in shaping tax revenues of local budgets in foreign countries and Ukraine. The analysis of state policy of financial support for regional development in Ukraine. The structure of tax revenue in the context of changes in the budget and tax legislation in a decentralized tax powers. Systematized features of fiscal decentralization in Ukraine. Problems and grounded main ways of optimizing the formation of local budgets in a decentralized tax powers. Formed selection of areas targeted as ways to increase economic and financial independence of regions of Ukraine.

  11. Fractional Power Control for Decentralized Wireless Networks

    CERN Document Server

    Jindal, Nihar; Andrews, Jeffrey G

    2007-01-01

    We propose and analyze a new paradigm for power control in decentralized wireless networks, termed fractional power control. Transmission power is chosen as the current channel quality raised to an exponent -s, where s is a constant between 0 and 1. Choosing s = 1 and s = 0 correspond to the familiar cases of channel inversion and constant power transmission, respectively. Choosing s in (0, 1) allows all intermediate policies between these two extremes to be evaluated, and we see that neither extreme is ideal. We prove that using an exponent of s = 1/2 optimizes the transmission capacity of an ad hoc network, meaning that the inverse square root of the channel strength is the optimal transmit power scaling. Intuitively, this choice achieves the optimal balance between helping disadvantaged users while making sure they do not flood the network with interference.

  12. Rollout Sampling Policy Iteration for Decentralized POMDPs

    CERN Document Server

    Wu, Feng; Chen, Xiaoping

    2012-01-01

    We present decentralized rollout sampling policy iteration (DecRSPI) - a new algorithm for multi-agent decision problems formalized as DEC-POMDPs. DecRSPI is designed to improve scalability and tackle problems that lack an explicit model. The algorithm uses Monte- Carlo methods to generate a sample of reachable belief states. Then it computes a joint policy for each belief state based on the rollout estimations. A new policy representation allows us to represent solutions compactly. The key benefits of the algorithm are its linear time complexity over the number of agents, its bounded memory usage and good solution quality. It can solve larger problems that are intractable for existing planning algorithms. Experimental results confirm the effectiveness and scalability of the approach.

  13. Decentralized Overlay for Federation of Enterprise Clouds

    CERN Document Server

    Ranjan, Rajiv

    2008-01-01

    This chapter describes Aneka-Federation, a decentralized and distributed system that combines enterprise Clouds, overlay networking, and structured peer-to-peer techniques to create scalable wide-area networking of compute nodes for high-throughput computing. The Aneka-Federation integrates numerous small scale Aneka Enterprise Cloud services and nodes that are distributed over multiple control and enterprise domains as parts of a single coordinated resource leasing abstraction. The system is designed with the aim of making distributed enterprise Cloud resource integration and application programming flexible, efficient, and scalable. The system is engineered such that it: enables seamless integration of existing Aneka Enterprise Clouds as part of single wide-area resource leasing federation; self-organizes the system components based on a structured peer-to-peer routing methodology; and presents end-users with a distributed application composition environment that can support variety of programming and execu...

  14. Load scheduling for decentralized CHP plants

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg, orlov 31.07.2008; Madsen, Henrik; Nielsen, Torben Skov

    This report considers load scheduling for decentralized combined heat and power plants where the revenue from selling power to the transmission company and the fuel cost may be time-varying. These plants produce both heat and power with a fixed ratio between these outputs. A heat storage facility...... is used to be able to deviate from this restriction. The load scheduling must be performed with only approximate knowledge about the future. At present in Denmark this uncertainty is only associated with the heat demand, but in the future revenues of produced energy and the fuel costs might also...... be uncertain and dependent on time. It is suggested to use a combination of background knowledge of the operator and computer tools to solve the scheduling problem. More specificly it is suggested that the plant is equipped with (i) an automatic on-line system for forecasting the heat demand, (ii...

  15. Decentralized energy systems for clean electricity access

    Science.gov (United States)

    Alstone, Peter; Gershenson, Dimitry; Kammen, Daniel M.

    2015-04-01

    Innovative approaches are needed to address the needs of the 1.3 billion people lacking electricity, while simultaneously transitioning to a decarbonized energy system. With particular focus on the energy needs of the underserved, we present an analytic and conceptual framework that clarifies the heterogeneous continuum of centralized on-grid electricity, autonomous mini- or community grids, and distributed, individual energy services. A historical analysis shows that the present day is a unique moment in the history of electrification where decentralized energy networks are rapidly spreading, based on super-efficient end-use appliances and low-cost photovoltaics. We document how this evolution is supported by critical and widely available information technologies, particularly mobile phones and virtual financial services. These disruptive technology systems can rapidly increase access to basic electricity services and directly inform the emerging Sustainable Development Goals for quality of life, while simultaneously driving action towards low-carbon, Earth-sustaining, inclusive energy systems.

  16. Influence of cardiac decentralization on cardioprotection.

    Directory of Open Access Journals (Sweden)

    John G Kingma

    Full Text Available The role of cardiac nerves on development of myocardial tissue injury after acute coronary occlusion remains controversial. We investigated whether acute cardiac decentralization (surgical modulates coronary flow reserve and myocardial protection in preconditioned dogs subject to ischemia-reperfusion. Experiments were conducted on four groups of anesthetised, open-chest dogs (n = 32: 1- controls (CTR, intact cardiac nerves, 2- ischemic preconditioning (PC; 4 cycles of 5-min IR, 3- cardiac decentralization (CD and 4- CD+PC; all dogs underwent 60-min coronary occlusion and 180-min reperfusion. Coronary blood flow and reactive hyperemic responses were assessed using a blood volume flow probe. Infarct size (tetrazolium staining was related to anatomic area at risk and coronary collateral blood flow (microspheres in the anatomic area at risk. Post-ischemic reactive hyperemia and repayment-to-debt ratio responses were significantly reduced for all experimental groups; however, arterial perfusion pressure was not affected. Infarct size was reduced in CD dogs (18.6 ± 4.3; p = 0.001, data are mean ± 1 SD compared to 25.2 ± 5.5% in CTR dogs and was less in PC dogs as expected (13.5 ± 3.2 vs. 25.2 ± 5.5%; p = 0.001; after acute CD, PC protection was conserved (11.6 ± 3.4 vs. 18.6 ± 4.3%; p = 0.02. In conclusion, our findings provide strong evidence that myocardial protection against ischemic injury can be preserved independent of extrinsic cardiac nerve inputs.

  17. Macroeconomic Effects In Centralized And Decentralized Wage Setting Systems

    OpenAIRE

    Sorolla, Valeri

    2000-01-01

    We present a model of a monetary economy with two systems of wage setting: a decentralized system and a centralized system. In the decentralized system there is a union per firm that sets the firm's wage. In the centralized system there is a unique union that sets a common wage for all firms. We find that, when there is unemployment, the equilibrium wage set in the centralized wage setting system is lower than the one set in the decentralized wage setting and that both depend on the size of t...

  18. Analysis and design of robust decentralized controllers for nonlinear systems

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwald, D.A.

    1993-07-01

    Decentralized control strategies for nonlinear systems are achieved via feedback linearization techniques. New results on optimization and parameter robustness of non-linear systems are also developed. In addition, parametric uncertainty in large-scale systems is handled by sensitivity analysis and optimal control methods in a completely decentralized framework. This idea is applied to alleviate uncertainty in friction parameters for the gimbal joints on Space Station Freedom. As an example of decentralized nonlinear control, singular perturbation methods and distributed vibration damping are merged into a control strategy for a two-link flexible manipulator.

  19. Responsiveness and flexibility in a Decentralized Supply Chain

    DEFF Research Database (Denmark)

    Petersen, Kristian Rasmus; Bilberg, Arne; Hadar, Ronen

    Today’s supply chains are not capable of managing the instabilities that is the case in the market. Instead, there is a need to develop supply chains that are capable of adapting to changes. Through a case study of LEGO, the authors suggest a possible solution: a decentralized supply chain serving...... independent and self-sufficient local factories. The decentralized supply chain is provided with materials, parts and pre-assembled elements from local suppliers and supplies the local market in return. Keywords: Decentralize, Responsiveness, Flexibility...

  20. Self-organized synchronization in decentralized power grids.

    Science.gov (United States)

    Rohden, Martin; Sorge, Andreas; Timme, Marc; Witthaut, Dirk

    2012-08-10

    Robust synchronization (phase locking) of power plants and consumers centrally underlies the stable operation of electric power grids. Despite current attempts to control large-scale networks, even their uncontrolled collective dynamics is not fully understood. Here we analyze conditions enabling self-organized synchronization in oscillator networks that serve as coarse-scale models for power grids, focusing on decentralizing power sources. Intriguingly, we find that whereas more decentralized grids become more sensitive to dynamical perturbations, they simultaneously become more robust to topological failures. Decentralizing power sources may thus facilitate the onset of synchronization in modern power grids.

  1. DECENTRALIZED STABILIZATION OF A CLASS OF INTERCONNECTED SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper is concerned with the decentralized stabilization of continuous and discrete linear interconnected systems with the structural constraints about the interconnection matrices. For the continuous case,the main improvement in the paper as compared with the corresponding results in the literature is to extend the considered class of systems from S to S*(both will be defined in the paper)without resulting in high decentralized gain and difficult numerical computation. The algorithm for obtaining decentralized state feedback control to stable the overall system is presented. The discrete case and some very useful results are discussed as well.

  2. On the efficiency of decentralized exchange with resale possibilities

    DEFF Research Database (Denmark)

    Groes, Ebbe; Tranæs, Torben

    1999-01-01

    . If resale is possible and transaction costs are negligible, we would nevertheless expect an efficient allocation to result from decentralized exchange. This paper suggests that this depends on the nature of the commodity; while the allocation of a durable good will be efficient, the allocation......This paper studies decentralized exchange by bilateral matching and bargaining when resale is possible. Decentralized exchange involves the risk that goods and services may be allocated inefficiently; if low-valuation buyers consume while high-valuation buyers do not, then social welfare is reduced...

  3. Centralized vs. De-centralized Multinationals and Taxes

    DEFF Research Database (Denmark)

    Nielsen, Søren Bo; Raimondos-Møller, Pascalis; Schjelderup, Guttorm

    2005-01-01

    The paper examines how country tax differences affect a multinational enterprise's choice to centralize or de-centralize its decision structure. Within a simple model that emphasizes the multiple conflicting roles of transfer prices in MNEs - here, as a strategic pre-commitment device and a tax...... manipulation instrument -, we show that (de-)centralized decisions are more profitable when tax differentials are (small) large.Keywords: Centralized vs. de-centralized decisions, taxes, MNEs.JEL-Classification: H25, F23, L23....

  4. Improvement of Axial Resolution in Confocal Microscopy by an Optical Pupil Filter with Two Zones Phase-Shifted by π

    Institute of Scientific and Technical Information of China (English)

    林列; 王湘晖; 王肇圻; 母国光

    2003-01-01

    A filter with two zones phase-shifted by π is proposed to improve the axial resolution of confocal microscopes with a finite-sized detector. The optimum axial resolution for a given size of the detector can be achieved by adjusting the zone boundary of the filter. The experimental results are well in agreement with the theoretical predictions.

  5. Growth, mechanical, and magnetic study of SmFeO{sub 3} single crystal grown by optical floating zone technique

    Energy Technology Data Exchange (ETDEWEB)

    Babu, P. Ramesh [Centre for Crystal Growth, VIT University, Vellore, Tamil Nadu (India); Bhaumik, Indranil [Crystal Growth Laboratory, Laser Materials Development and Devices Division, RRCAT, Indore (India); Ganesamoorthy, S. [Material Science Group, IGCAR, Kalpakkam, Tamil Nadu (India); Kalainathan, S., E-mail: kalainathan@yahoo.com [Centre for Crystal Growth, VIT University, Vellore, Tamil Nadu (India); Bhatt, R.; Karnal, A.K.; Gupta, P.K. [Crystal Growth Laboratory, Laser Materials Development and Devices Division, RRCAT, Indore (India)

    2016-08-15

    Single crystals of Samarium orthoferrite (SmFeO{sub 3}) have been grown by the optical floating zone technique. The growth parameters to yield good quality crystals are 5 mm/h for pulling and 30–40 rpm for rotation. The mechanical behavior of the grown crystal has been investigated. Rosette pattern has been observed around the indentation and the microhardness has been found to decreases non-linearly with the applied load. For load higher than 1.96 N there is a transition from palmqvist to median crack due to plastic deformation of the crystal. The hardness parameters like fracture toughness, brittleness index, and yield strength have also been calculated for palmqvist and median cracks occurring on the crystal surface. The magnetic investigations revealed that a magnetic transition in the range of 300–180 K. Above 180 K, the magnetization decreases as Sm and Fe sublattices have opposite spins. At high temperature, two anomalies are observed, one due to near spin reorientation (T{sub SR} = 480 K) and the other is AFM to paramagnetic transitions (T{sub N} = 670 K). The M–H curves exhibit a shape change with temperature due to the emergence and enlargement of multi-domain state of the SmFeO{sub 3} crystals. Bloch parameter (3.28 × 10{sup −5} K{sup −3/2}) has also been evaluated. - Highlights: • SmFeO{sub 3} single crystals have been grown by OFZ technique in air. • The microhardness has been found to decreases non-linearly with the applied load. • At 472 K, spin reorientation occurs in Fe sublattice. • The M–H curves exhibit a shape change with temperature due to the emergence and enlargement of multi-domain state. • Bloch 3/2-law holds good for SmFeO{sub 3} (B-parameter as 3.28 × 10{sup −5} K{sup −3/2}).

  6. Communication-Based Decomposition Mechanisms for Decentralized MDPs

    CERN Document Server

    Goldman, Claudia V; 10.1613/jair.2466

    2011-01-01

    Multi-agent planning in stochastic environments can be framed formally as a decentralized Markov decision problem. Many real-life distributed problems that arise in manufacturing, multi-robot coordination and information gathering scenarios can be formalized using this framework. However, finding the optimal solution in the general case is hard, limiting the applicability of recently developed algorithms. This paper provides a practical approach for solving decentralized control problems when communication among the decision makers is possible, but costly. We develop the notion of communication-based mechanism that allows us to decompose a decentralized MDP into multiple single-agent problems. In this framework, referred to as decentralized semi-Markov decision process with direct communication (Dec-SMDP-Com), agents operate separately between communications. We show that finding an optimal mechanism is equivalent to solving optimally a Dec-SMDP-Com. We also provide a heuristic search algorithm that converges...

  7. Decentralized control of large flexible structures by joint decoupling

    Science.gov (United States)

    Su, Tzu-Jeng; Juang, Jer-Nan

    1994-01-01

    This paper presents a novel method to design decentralized controllers for large complex flexible structures by using the idea of joint decoupling. Decoupling of joint degrees of freedom from the interior degrees of freedom is achieved by setting the joint actuator commands to cancel the internal forces exerting on the joint degrees of freedom. By doing so, the interactions between substructures are eliminated. The global structure control design problem is then decomposed into several substructure control design problems. Control commands for interior actuators are set to be localized state feedback using decentralized observers for state estimation. The proposed decentralized controllers can operate successfully at the individual substructure level as well as at the global structure level. Not only control design but also control implementation is decentralized. A two-component mass-spring-damper system is used as an example to demonstrate the proposed method.

  8. Decentralization of school management to boards of governors in ...

    African Journals Online (AJOL)

    ICL

    Keywords: Educational management; decentralized management; school management; boards of ... institutions must be based on professional management practices. .... Efficient and effective allocation of resources, based on a school budget; .... culture, high academic performance, good human relationships, and sense of ...

  9. An interactive heuristic for financial planning in decentralized organizations.

    NARCIS (Netherlands)

    M.H. Goedhart; J. Spronk (Jaap)

    1995-01-01

    textabstractPlanning and controlling overall performance in decentralized organizations is a complex task for central management because it is contronted with incomplete information on organizational opportunities and possible conflicts of interest with local managers. Many formal procedures for the

  10. Engaging Social Capital for Decentralized Urban Stormwater Management

    Science.gov (United States)

    Decentralized approaches to urban stormwater management, whereby installations of green infrastructure (e.g., rain gardens, bioswales, and constructed wetlands) are dispersed throughout a management area, are cost-effective solutions with co-benefits beyond water abatement. Inste...

  11. Low Decision Space Means No Decentralization in Fiji

    Science.gov (United States)

    Faguet, Jean-Paul

    2016-01-01

    Mohammed, North, and Ashton find that decentralization in Fiji shifted health-sector workloads from tertiary hospitals to peripheral health centres, but with little transfer of administrative authority from the centre. Decision-making in five functional areas analysed remains highly centralized. They surmise that the benefits of decentralization in terms of services and outcomes will be limited. This paper invokes Faguet’s (2012) model of local government responsiveness and accountability to explain why this is so – not only for Fiji, but in any country that decentralizes workloads but not the decision space of local governments. A competitive dynamic between economic and civic actors that interact to generate an open, competitive politics, which in turn produces accountable, responsive government can only occur where real power and resources have been devolved to local governments. Where local decision space is lacking, by contrast, decentralization is bound to fail because it has not really happened in the first place. PMID:27801361

  12. Engaging Social Capital for Decentralized Urban Stormwater Management

    Science.gov (United States)

    Decentralized approaches to urban stormwater management, whereby installations of green infrastructure (e.g., rain gardens, bioswales, and constructed wetlands) are dispersed throughout a management area, are cost-effective solutions with co-benefits beyond water abatement. Inste...

  13. An interactive heuristic for financial planning in decentralized organizations.

    NARCIS (Netherlands)

    M.H. Goedhart; J. Spronk (Jaap)

    1995-01-01

    textabstractPlanning and controlling overall performance in decentralized organizations is a complex task for central management because it is contronted with incomplete information on organizational opportunities and possible conflicts of interest with local managers. Many formal procedures for the

  14. Decentralized Neural Backstepping Control Applied to a Robot Manipulator

    OpenAIRE

    Ramon Garcia-Hernandez; Ruz-Hernandez, Jose A.; Jose L. Rullan-Lara

    2013-01-01

    This paper presents a discrete‐time decentralized control scheme for trajectory tracking of a two degrees of freedom (DOF) robot manipulator. A high order neural network (HONN) is used to approximate a decentralized control law designed by the backstepping technique as applied to a block strict feedback form (BSFF). The weights for each neural network are adapted online by an extended Kalman filter training algorithm. The motion for each joint is controlled independently using only local angu...

  15. A Decentralized Variable Ordering Method for Distributed Constraint Optimization

    Science.gov (United States)

    2005-05-01

    Either aproach can be used depending on how densely the nodes are connected inside blocks. If inside-block connec- tivity is sparse, the latter method ...A Decentralized Variable Ordering Method for Distributed Constraint Optimization Anton Chechetka Katia Sycara CMU-RI-TR-05-18 May 2005 Robotics...00-00-2005 4. TITLE AND SUBTITLE A Decentralized Variable Ordering Method for Distributed Constraint Optimization 5a. CONTRACT NUMBER 5b. GRANT

  16. Decentralization and Participatory Rural Development: A Literature Review

    OpenAIRE

    Muhammad Shakil Ahmad; Noraini Bt. Abu Talib

    2011-01-01

    Most of the developing nations are still struggling for efficient use of their resources. In order to overcome physical and administrative constraints of the development, it is necessary to transfer the power from the central government to local authorities. Distribution of power from improves the management of resources and community participation which is considered key to sustainable development. Advocates of decentralization argue that decentralized government is source to improve communi...

  17. Responsiveness and flexibility in a Decentralized Supply Chain

    OpenAIRE

    Petersen, Kristian Rasmus; Bilberg, Arne; Hadar, Ronen

    2012-01-01

    Today’s supply chains are not capable of managing the instabilities that is the case in the market. Instead, there is a need to develop supply chains that are capable of adapting to changes. Through a case study of LEGO, the authors suggest a possible solution: a decentralized supply chain serving independent and self-sufficient local factories. The decentralized supply chain is provided with materials, parts and pre-assembled elements from local suppliers and supplies the local market in ret...

  18. Emergent Semantics Interoperability in Large-Scale Decentralized Information Systems

    CERN Document Server

    Cudré-Mauroux, Philippe

    2008-01-01

    Peer-to-peer systems are evolving with new information-system architectures, leading to the idea that the principles of decentralization and self-organization will offer new approaches in informatics, especially for systems that scale with the number of users or for which central authorities do not prevail. This book describes a new way of building global agreements (semantic interoperability) based only on decentralized, self-organizing interactions.

  19. 光学浮区法生长的 GdFeO3单晶%GdFeO3 monocrystal prepared by optical floating zone method

    Institute of Scientific and Technical Information of China (English)

    王占亮; 武安华; 景财年; 占晟; 曹世勋; 徐军

    2013-01-01

      正交钙钛矿结构 GdFeO3材料是一种新型的磁光材料。采用光学浮区法生长磁光晶体 GdFeO3,通过多次试验,生长出的晶体直径达到8mm,长度为50~80mm,晶体截面抛光后未发现明显的夹杂物等缺陷。测试结果证明光学浮区法是生长 GdFeO3磁光晶体的有效方法。%  Gadolinium orthoferrite crystals (GdFeO3) with orthogonal perovskite structure is a novel magneto-optical crystal. The magneto-optical crystal GdFeO3 (gadolinium orthoferrite) was grown by floating zone method. The growth parameters were optimized and GdFeO3 single crystal was prepared with diameter of up to 8mm and length of 50-80mm. There are no visible inclusions on the polished surface. The test results prove that floating zone method is an effective technology to grow GdFeO3 magneto-optical crystal.

  20. Subsidiarity in Principle: Decentralization of Water Resources Management

    Directory of Open Access Journals (Sweden)

    Ryan Stoa

    2014-05-01

    Full Text Available The subsidiarity principle of water resources management suggests that water management and service delivery should take place at the lowest appropriate governance level. The principle is attractive for several reasons, primarily because: 1 the governance level can be reduced to reflect environmental characteristics, such as the hydrological borders of a watershed that would otherwise cross administrative boundaries; 2 decentralization promotes community and stakeholder engagement when decision-making is localized; 3 inefficiencies are reduced by eliminating reliance on central government bureaucracies and budgetary constraints; and 4 laws and institutions can be adapted to reflect localized conditions at a scale where integrated natural resources management and climate change adaptation is more focused. Accordingly, the principle of subsidiarity has been welcomed by many states committed to decentralized governance, integrated water resources management, and/or civic participation. However, applications of decentralization have not been uniform, and in some cases have produced frustrating outcomes for states and water resources. Successful decentralization strategies are heavily dependent on dedicated financial resources and human resource capacity. This article explores the nexus between the principle of subsidiarity and the enabling environment, in the hope of articulating factors likely to contribute to, or detract from, the success of decentralized water resources management. Case studies from Haiti, Rwanda, and the United States’ Florida Water Management Districts provide examples of the varied stages of decentralization.

  1. Taking stock of decentralized disaster risk reduction in Indonesia

    Science.gov (United States)

    Grady, Anthony; Gersonius, Berry; Makarigakis, Alexandros

    2016-09-01

    The Sendai Framework, which outlines the global course on disaster risk reduction until 2030, places strong importance on the role of local government in disaster risk reduction. An aim of decentralization is to increase the influence and authority of local government in decision making. Yet, there is limited empirical evidence of the extent, character and effects of decentralization in current disaster risk reduction implementation, and of the barriers that are most critical to this. This paper evaluates decentralization in relation to disaster risk reduction in Indonesia, chosen for its recent actions to decentralize governance of DRR coupled with a high level of disaster risk. An analytical framework was developed to evaluate the various dimensions of decentralized disaster risk reduction, which necessitated the use of a desk study, semi-structured interviews and a gap analysis. Key barriers to implementation in Indonesia included: capacity gaps at lower institutional levels, low compliance with legislation, disconnected policies, issues in communication and coordination and inadequate resourcing. However, any of these barriers are not unique to disaster risk reduction, and similar barriers have been observed for decentralization in other developing countries in other public sectors.

  2. Subsidiarity in Principle: Decentralization of Water Resources Management

    Directory of Open Access Journals (Sweden)

    Ryan Stoa

    2014-05-01

    Full Text Available The subsidiarity principle of water resources management suggests that water management and service delivery should take place at the lowest appropriate governance level. The principle is attractive for several reasons, primarily because: 1 the governance level can be reduced to reflect environmental characteristics, such as the hydrological borders of a watershed that would otherwise cross administrative boundaries; 2 decentralization promotes community and stakeholder engagement when decision-making is localized; 3 inefficiencies are reduced by eliminating reliance on central government bureaucracies and budgetary constraints; and 4 laws and institutions can be adapted to reflect localized conditions at a scale where integrated natural resources management and climate change adaptation is more focused. Accordingly, the principle of subsidiarity has been welcomed by many states committed to decentralized governance, integrated water resources management, and/or civic participation. However, applications of decentralization have not been uniform, and in some cases have produced frustrating outcomes for states and water resources. Successful decentralization strategies are heavily dependent on dedicated financial resources and human resource capacity. This article explores the nexus between the principle of subsidiarity and the enabling environment, in the hope of articulating factors likely to contribute to, or detract from, the success of decentralized water resources management. Case studies from Haiti, Rwanda, and the United States’ Florida Water Management Districts provide examples of the varied stages of decentralization.

  3. The snow system: A decentralized medical data processing system.

    Science.gov (United States)

    Bellika, Johan Gustav; Henriksen, Torje Starbo; Yigzaw, Kassaye Yitbarek

    2015-01-01

    Systems for large-scale reuse of electronic health record data is claimed to have the potential to transform the current health care delivery system. In principle three alternative solutions for reuse exist: centralized, data warehouse, and decentralized solutions. This chapter focuses on the decentralized system alternative. Decentralized systems may be categorized into approaches that move data to enable computations or move computations to the where data is located to enable computations. We describe a system that moves computations to where the data is located. Only this kind of decentralized solution has the capabilities to become ideal systems for reuse as the decentralized alternative enables computation and reuse of electronic health record data without moving or exposing the information to outsiders. This chapter describes the Snow system, which is a decentralized medical data processing system, its components and how it has been used. It also describes the requirements this kind of systems need to support to become sustainable and successful in recruiting voluntary participation from health institutions.

  4. Rethinking Decentralization in Education in terms of Administrative Problems

    Directory of Open Access Journals (Sweden)

    Vasiliki Papadopoulou

    2013-11-01

    Full Text Available The general purpose of this study is to thoroughly examine decentralization in education according to the literature and previous research, and to discuss the applicability of educational decentralization practices in Turkey. The literature was reviewed for the study and findings reported. It has been observed that decentralization in education practices were realized in many countries after the 1980’s. It is obvious that the educational system in Turkey has difficulty in meeting the needs, and encounters many problems due to its present centralist state. Educational decentralization can provide effective solutions for stakeholder engagement, educational financing and for problems in decision making and operation within the education system. However, the present state of local governments, the legal framework, geographical, cultural and social features indicate that Turkey’s conditions are not ready for decentralization in education. A decentralization model realized in the long run according to Turkey’s conditions, and as a result of a social consensus, can help resolve the problems of the Turkish education system.

  5. Bandwidth Partitioning in Decentralized Wireless Networks

    CERN Document Server

    Jindal, Nihar; Weber, Steven

    2007-01-01

    This paper addresses the following question, which is of interest in the design of a multiuser decentralized network. Given a total system bandwidth of W Hz and a fixed data rate constraint of R bps for each transmission, how many frequency slots N of size W/N should the band be partitioned into in order to maximize the number of simultaneous links in the network? Dividing the available spectrum results in two competing effects. On the positive side, a larger N allows for more parallel, non-interfering communications to take place in the same area. On the negative side, a larger N increases the SINR requirement for each link because the same information rate must be achieved over less bandwidth, which in turn increases the area consumed by each transmission. Exploring this tradeoff and determining the optimum value of N in terms of the system parameters is the focus of the paper. Using stochastic geometry, the optimal SINR threshold - which directly corresponds to the optimal spectral efficiency - is derived ...

  6. Decentralized provenance-aware publishing with nanopublications

    Directory of Open Access Journals (Sweden)

    Tobias Kuhn

    2016-08-01

    Full Text Available Publication and archival of scientific results is still commonly considered the responsability of classical publishing companies. Classical forms of publishing, however, which center around printed narrative articles, no longer seem well-suited in the digital age. In particular, there exist currently no efficient, reliable, and agreed-upon methods for publishing scientific datasets, which have become increasingly important for science. In this article, we propose to design scientific data publishing as a web-based bottom-up process, without top-down control of central authorities such as publishing companies. Based on a novel combination of existing concepts and technologies, we present a server network to decentrally store and archive data in the form of nanopublications, an RDF-based format to represent scientific data. We show how this approach allows researchers to publish, retrieve, verify, and recombine datasets of nanopublications in a reliable and trustworthy manner, and we argue that this architecture could be used as a low-level data publication layer to serve the Semantic Web in general. Our evaluation of the current network shows that this system is efficient and reliable.

  7. Establishing trust in decentralized smart sensor networks

    Science.gov (United States)

    Vagts, H.; Cosar, T.; Beyerer, J.

    2011-06-01

    Smart sensors can gather all kind of information and process it. Cameras are still dominating and smart cameras can offer services for face recognition or person tracking. Operators are building collaborations to cover a larger area, to save costs and to add more and different sensors. Cryptographic methods may achieve integrity and confidentiality between operators, but not trust. Even if a partner or one of his sensors is authenticated, no statements can be made about the quality of the sensor data. Hence, trust must be established between the partners and their sensors. Trust can be built based on past experience. A reputation system collects opinions of operators about the behavior of sensors and calculates trust based on these opinions. Many reputation systems have been proposed, e.g., for authentication of files in peer-topeer networks. This work presents a new reputation system, which is designed to calculate the trustworthiness of smart sensors and smart sensor systems. A new trust model, including functions to calculate and update trust on past experiences, is proposed. When fusing information of multiple sensors, it cannot always be reconstructed, which information led to a bad result. Hence, an approach for fair rating is shown. The proposed system has been realized in a Service-Oriented Architecture for easy integration in existing smart sensor systems, e.g., smart surveillance systems. The model itself can be used in every decentralized heterogeneous smart sensor network.

  8. Platform Architecture for Decentralized Positioning Systems

    Directory of Open Access Journals (Sweden)

    Zakaria Kasmi

    2017-04-01

    Full Text Available A platform architecture for positioning systems is essential for the realization of a flexible localization system, which interacts with other systems and supports various positioning technologies and algorithms. The decentralized processing of a position enables pushing the application-level knowledge into a mobile station and avoids the communication with a central unit such as a server or a base station. In addition, the calculation of the position on low-cost and resource-constrained devices presents a challenge due to the limited computing, storage capacity, as well as power supply. Therefore, we propose a platform architecture that enables the design of a system with the reusability of the components, extensibility (e.g., with other positioning technologies and interoperability. Furthermore, the position is computed on a low-cost device such as a microcontroller, which simultaneously performs additional tasks such as data collecting or preprocessing based on an operating system. The platform architecture is designed, implemented and evaluated on the basis of two positioning systems: a field strength system and a time of arrival-based positioning system.

  9. The Value of Feedback in Decentralized Detection

    CERN Document Server

    Tay, Wee Peng

    2011-01-01

    We consider the decentralized binary hypothesis testing problem in networks with feedback, where some or all of the sensors have access to compressed summaries of other sensors' observations. We study certain two-message feedback architectures, in which every sensor sends two messages to a fusion center, with the second message based on full or partial knowledge of the first messages of the other sensors. We also study one-message feedback architectures, in which each sensor sends one message to a fusion center, with a group of sensors having full or partial knowledge of the messages from the sensors not in that group. Under either a Neyman-Pearson or a Bayesian formulation, we show that the asymptotically optimal (in the limit of a large number of sensors) detection performance (as quantified by error exponents) does not benefit from the feedback messages, if the fusion center remembers all sensor messages. However, feedback can improve the Bayesian detection performance in the one-message feedback architect...

  10. Decentralized adaptive fuzzy control of robot manipulators.

    Science.gov (United States)

    Jin, Y

    1998-01-01

    This paper develops a decentralized adaptive fuzzy control scheme for robot manipulators via a combination of genetic algorithm and gradient method. The controller for each link consists of a feedforward fuzzy torque-computing system and a feedback fuzzy PD system. The feedforward fuzzy system is trained and optimized off-line by an improved genetic algorithm, that is to say, not only the parameters but also the structure of the fuzzy system are self-organized. Because genetic algorithm can operate successfully without the system model, no exact inverse dynamics of the robot system are required. The feedback fuzzy PD system, on the other hand, is tuned on-line using gradient method. In this way, the proportional and derivative gains are adjusted properly to keep the closed-loop system stable. The proposed controller has the following merits: (1) it needs no exact dynamics of the robot systems and the computation is time-saving because of the simple structure of the fuzzy systems; and (2) the controller is insensitive to various dynamics and payload uncertainties in robot systems. These are demonstrated by analyses of the computational complexity and various computer simulations.

  11. mSCTP Based Decentralized Mobility Framework

    Directory of Open Access Journals (Sweden)

    Waqas A. Imtiaz

    2011-09-01

    Full Text Available To conceive the full potential of wireless IP services, Mobile Nodes (MNs must be able to roam seamlessly across different networks. Mobile Stream Control Transmission Protocol (mSCTP is a transport layer solution, which unlike Mobile IP (MIP, provides seamless mobility with minimum delay and negligible packet loss. However, mSCTP fails to locate the current IP address of the mobile node when Correspondent Node (CN wants to initiate a session. In this paper, we propose DHT Chord to provide the required location management. Chord is a P2P algorithm, which can efficiently provide the IP address of the called MN by using its key-value mapping. The proposed decentralized mobility framework collectively exploits the multihoming feature of mSCTP, and efficient key-value mapping of chord to provide seamless mobility. Suitability of the framework is analyzed by preliminary analysis of chord lookup efficiency, and mSCTP handover procedure using overlay weaver and NS-2. Performance analysis shows that mSCTP multihoming feature and Chord efficient key-value mapping can provide a non-delayed, reliable, and an efficient IP handover solution.

  12. Platform Architecture for Decentralized Positioning Systems.

    Science.gov (United States)

    Kasmi, Zakaria; Norrdine, Abdelmoumen; Blankenbach, Jörg

    2017-04-26

    A platform architecture for positioning systems is essential for the realization of a flexible localization system, which interacts with other systems and supports various positioning technologies and algorithms. The decentralized processing of a position enables pushing the application-level knowledge into a mobile station and avoids the communication with a central unit such as a server or a base station. In addition, the calculation of the position on low-cost and resource-constrained devices presents a challenge due to the limited computing, storage capacity, as well as power supply. Therefore, we propose a platform architecture that enables the design of a system with the reusability of the components, extensibility (e.g., with other positioning technologies) and interoperability. Furthermore, the position is computed on a low-cost device such as a microcontroller, which simultaneously performs additional tasks such as data collecting or preprocessing based on an operating system. The platform architecture is designed, implemented and evaluated on the basis of two positioning systems: a field strength system and a time of arrival-based positioning system.

  13. Using a Novel Wireless-Networked Decentralized Control Scheme under Unpredictable Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Chung-Liang Chang

    2015-11-01

    Full Text Available The direction of sunshine or the installation sites of environmental control facilities in the greenhouse result in different temperature and humidity levels in the various zones of the greenhouse, and thus, the production quality of crop is inconsistent. This study proposed a wireless-networked decentralized fuzzy control scheme to regulate the environmental parameters of various culture zones within a greenhouse. The proposed scheme can create different environmental conditions for cultivating different crops in various zones and achieve diversification or standardization of crop production. A star-type wireless sensor network is utilized to communicate with each sensing node, actuator node, and control node in various zones within the greenhouse. The fuzzy rule-based inference system is used to regulate the environmental parameters for temperature and humidity based on real-time data of plant growth response provided by a growth stage selector. The growth stage selector defines the control ranges of temperature and humidity of the various culture zones according to the leaf area of the plant, the number of leaves, and the cumulative amount of light. The experimental results show that the proposed scheme is stable and robust and provides basis for future greenhouse applications.

  14. Controlled reshaping of the front surface of the cornea through its full-area ablation outside of the optical zone with a Gaussian ArF excimer laser beam

    Science.gov (United States)

    Semchishen, A. V.; Semchishen, V. A.

    2014-01-01

    We studied in vitro the response of the topography of the cornea to its full-area laser ablation (the laser beam spot diameter is commensurable with the size of the interface) outside of the central zone with an excimer laser having a Gaussian fluence distribution across the beam. Subject to investigation were the topographically controlled surface changes of the anterior cornea in 60 porcine eyes with a 5 ± 1.25-diopter artificially induced astigmatism, the changes being caused by laser ablation of the stromal collagen in two 3.5-mm-dia. circular areas along the weaker astigmatism axis. Experimental relationships are presented between the actual astigmatism correction and the expected correction for the intact optical zones 1, 2, 3, and 4 mm in diameter. The data for each zone were approximated by the least-squares method with the function d = a + bx. The coefficient b is given with the root-mean-square error. The statistical processing of the data yielded the following results: d = (0.14 ± 0.037)x for the 1-mm-dia. optical zone, (1.10 ± 0.036)x for the 2-mm-dia. optical zone, (1.04 ± 0.020)x for the 3-mm-dia. optical zone, and (0.55 ± 0.04)x for the 4-mm-dia. optical zone. Full astigmatism correction was achieved with ablation effected outside of the 3-mm-dia. optical zone. The surface changes of the cornea are shown to be due not only to the removal of the corneal tissue, but also to the biomechanical topographic response of the cornea to its strain caused by the formation of a dense pseudomembrane in the ablation area.

  15. Hetero-seed and hetero-feed single crystal growth of SmxDy1-xFeO3 perovskites based on optical floating zone method

    Science.gov (United States)

    Xu, Kai; Zhao, Weiyao; Xing, Juanjuan; Gu, Hui; Ren, Wei; Zhang, Jincang; Cao, Shixun

    2017-06-01

    We studied samarium-dysprosium rare-earth orthoferrites SmxDy1-xFeO3 (SDFO, x = 0-1, interval 0.1) with 11 different x concentration values. All of the SDFO single crystals were successfully grown by a hetero-seed and hetero-feed optical-floating-zone technique in flowing air. The XRD powder patterns illustrate that the lattice mismatch of two samples with Δx = 0.1 is about 0.1-0.2% in ac plane, which is considered appropriate for our hetero-seed and hetero-feed crystal growth. Thus, we could successfully grow the series of SDFO single crystals continuously, for example, the x = 0.8 single crystal was grown on the x = 0.7 seed rod. X-ray back-reflection Laue photographs indicate good quality of all the as-grown SDFO single crystals. Composition analysis of SDFO single crystals were conducted by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), which demonstrate the accurate cation stoichiometry for each crystal. Moreover, we show that such crystal system possesses particular anisotropic magnetic property. The hetero-seed growth method and hetero-feed single crystal relay growth based on optical-floating-zone technique will be useful in high-throughput crystal materials growth.

  16. Medication as Infrastructure: Decentring Self-care

    Directory of Open Access Journals (Sweden)

    Peter Danholt

    2012-11-01

    Full Text Available Drawing on science and technology studies (STS, and specifically the concept of infrastructure as conceptualised by Bowker and Star (2000; Star 1999, this paper argues and empirically demonstrates that self-care may be considered a practice that is thoroughly sociotechnical, material, distributed and de-centred. Comparing the practices related to medication in the treatment of asthma, type 2 diabetes and haemophilia, we show that in practice there is no ‘self’ in self-care. More specifically, the ‘self’ in self-care is an actor who is highly dependent on, and intertwined with infrastructures of care, in order to be self-caring. Infrastructures of care are the more or less embedded ‘tracks’ along which care may ‘run’, shaping and being shaped by actors and settings along the way. Obtaining prescriptions, going to the pharmacy, bringing medication home and administering it as parts of daily life are commonplace activities embedded in the fabric of life, especially for those living with a chronic condition. However, this procurement and emplacement of medication involves the establishment and ongoing enactment of infrastructures of care, that is, the connections between various actors and locations that establish caring spaces and caring selves. Locations and actors are included as allies in treating chronic conditions outside the clinical setting, but these infrastructures may also be ambiguous, with respect to their effects; they may simultaneously contribute to the condition’s management and neglect. Particularly precarious is management at the fringes of healthcare infrastructure, where allies, routines and general predictability are scarce. We conclude by arguing that these insights may induce a greater sensitivity to existing infrastructures and practices, when seeking to introduce new infrastructures of care, such as those promoted under the headings of ‘telemedicine’ and ‘healthcare IT’.

  17. Centralization or decentralization of facial structures in Korean young adults.

    Science.gov (United States)

    Yoo, Ja-Young; Kim, Jeong-Nam; Shin, Kang-Jae; Kim, Soon-Heum; Choi, Hyun-Gon; Jeon, Hyun-Soo; Koh, Ki-Seok; Song, Wu-Chul

    2013-05-01

    It is well known that facial beauty is dictated by facial type, and harmony between the eyes, nose, and mouth. Furthermore, facial impression is judged according to the overall facial contour and the relationship between the facial structures. The aims of the present study were to determine the optimal criteria for the assessment of gathering or separation of the facial structures and to define standardized ratios for centralization or decentralization of the facial structures.Four different lengths were measured, and 2 indexes were calculated from standardized photographs of 551 volunteers. Centralization and decentralization were assessed using the width index (interpupillary distance / facial width) and height index (eyes-mouth distance / facial height). The mean ranges of the width index and height index were 42.0 to 45.0 and 36.0 to 39.0, respectively. The width index did not differ with sex, but males had more decentralized faces, and females had more centralized faces, vertically. The incidence rate of decentralized faces among the men was 30.3%, and that of centralized faces among the women was 25.2%.The mean ranges in width and height indexes have been determined in a Korean population. Faces with width and height index scores under and over the median ranges are determined to be "centralized" and "decentralized," respectively.

  18. Decentralizing conservation and diversifying livelihoods within Kanchenjunga Conservation Area, Nepal.

    Science.gov (United States)

    Parker, Pete; Thapa, Brijesh; Jacob, Aerin

    2015-12-01

    To alleviate poverty and enhance conservation in resource dependent communities, managers must identify existing livelihood strategies and the associated factors that impede household access to livelihood assets. Researchers increasingly advocate reallocating management power from exclusionary central institutions to a decentralized system of management based on local and inclusive participation. However, it is yet to be shown if decentralizing conservation leads to diversified livelihoods within a protected area. The purpose of this study was to identify and assess factors affecting household livelihood diversification within Nepal's Kanchenjunga Conservation Area Project, the first protected area in Asia to decentralize conservation. We randomly surveyed 25% of Kanchenjunga households to assess household socioeconomic and demographic characteristics and access to livelihood assets. We used a cluster analysis with the ten most common income generating activities (both on- and off-farm) to group the strategies households use to diversify livelihoods, and a multinomial logistic regression to identify predictors of livelihood diversification. We found four distinct groups of household livelihood strategies with a range of diversification that directly corresponded to household income. The predictors of livelihood diversification were more related to pre-existing socioeconomic and demographic factors (e.g., more landholdings and livestock, fewer dependents, receiving remittances) than activities sponsored by decentralizing conservation (e.g., microcredit, training, education, interaction with project staff). Taken together, our findings indicate that without direct policies to target marginalized groups, decentralized conservation in Kanchenjunga will continue to exclude marginalized groups, limiting a household's ability to diversify their livelihood and perpetuating their dependence on natural resources.

  19. Centralized versus decentralized decision-making for recycled material flows.

    Science.gov (United States)

    Hong, I-Hsuan; Ammons, Jane C; Realff, Matthew J

    2008-02-15

    A reverse logistics system is a network of transportation logistics and processing functions that collect, consolidate, refurbish, and demanufacture end-of-life products. This paper examines centralized and decentralized models of decision-making for material flows and associated transaction prices in reverse logistics networks. We compare the application of a centralized model for planning reverse production systems, where a single planner is acquainted with all of the system information and has the authority to determine decision variables for the entire system, to a decentralized approach. In the decentralized approach, the entities coordinate between tiers of the system using a parametrized flow function and compete within tiers based on reaching a price equilibrium. We numerically demonstrate the increase in the total net profit of the centralized system relative to the decentralized one. This implies that one may overestimate the system material flows and profit if the system planner utilizes a centralized viewto predict behaviors of independent entities in the system and that decentralized contract mechanisms will require careful design to avoid losses in the efficiency and scope of these systems.

  20. A Critical Look at Decentralized Personal Data Architectures

    CERN Document Server

    Narayanan, Arvind; Barocas, Solon; Nissenbaum, Helen; Boneh, Dan

    2012-01-01

    While the Internet was conceived as a decentralized network, the most widely used web applications today tend toward centralization. Control increasingly rests with centralized service providers who, as a consequence, have also amassed unprecedented amounts of data about the behaviors and personalities of individuals. Developers, regulators, and consumer advocates have looked to alternative decentralized architectures as the natural response to threats posed by these centralized services. The result has been a great variety of solutions that include personal data stores (PDS), infomediaries, Vendor Relationship Management (VRM) systems, and federated and distributed social networks. And yet, for all these efforts, decentralized personal data architectures have seen little adoption. This position paper attempts to account for these failures, challenging the accepted wisdom in the web community on the feasibility and desirability of these approaches. We start with a historical discussion of the development of v...

  1. Does Decentralized Leadership Influence the Performance of Czech Museums?

    Directory of Open Access Journals (Sweden)

    Plaček Michal

    2017-06-01

    Full Text Available This study tests whether decentralized leadership influences the efficiency of running selected cultural institutions, specifically museums in the Czech Republic. For the analysis, data from 2015 from 187 museums spread around the whole Czech Republic are used. The method for the evaluation of efficiency is data envelope analysis, and for identifying the influence of decentralized leadership, a regression analysis is used. Museums established by municipalities reach higher efficiency than museums established by regions and central government. The causes may be found in the ability to better estimate the local demand as well as in the rational behavior of municipalities that prefer a cost-minimization strategy. The benefits of decentralization cannot be seen only in the field of finance but also in reinforcing local traditions, trust and the effects of social capital that is generated by a strong regional cultural identity.

  2. The impulse influence function for de-centralized control

    Institute of Scientific and Technical Information of China (English)

    ZHONG Wanxie

    2004-01-01

    Impulse influence matrix function is introduced based on that the de-centralized control analysis is analogous to the sub-structural analysis in structural mechanics. The static sub-structural analysis is analogous to the usual de-centralized control, whereas the dynamic sub-structural analysis corresponds to the de-centralized control theory. The reciprocal symmetry for the impulse influence matrix function is proved, and is solved by the precise integration method for time invariant system, giving the results up to computer precision. Based on the impulse influence functions of subsystems, the combination of subsystems can lead to a set of integral equations and be solved numerically. Numerical example demonstrates the effectiveness of the method.

  3. Robust decentralized controller design for UPFC using μ-synthesis

    Science.gov (United States)

    Taher, Seyed Abbas; Akbari, Shahabeddin; Abdolalipour, Ali; Hematti, Reza

    2010-08-01

    In this paper a new method based on structured singular value ( μ-synthesis) is proposed for the robust decentralized unified power flow controller (UPFC) design. To achieve decentralization, using the Schauder fixed point theorem the synthesis and analysis of multi-input multi-output (MIMO) control system is transformed into a set of equivalent multi-input single-output (MISO) control system. To cope with power system uncertainties μ-synthesis technique is being used for designing of UPFC controllers. The proposed μ-based controller has a decentralized scheme which has the advantage of reduction in the controller complexity and suitability for practical implementation. The effectiveness of the proposed control strategy on damping low frequency oscillations is evaluated under different operating conditions and compared with the conventional controller to demonstrate its robust performance through nonlinear simulation and some performance indices.

  4. Smart panel with active damping units. Implementation of decentralized control.

    Science.gov (United States)

    Díaz, Cristóbal González; Paulitsch, Christoph; Gardonio, Paolo

    2008-08-01

    This paper contains the second part of a study on a smart panel with five decentralized velocity feedback control units using proof mass electrodynamic actuators [Gonzalez Diaz et al., J. Acoust. Soc. Am. 124, 886 (2008)]. The implementation of five decentralized control loops is analyzed, both theoretically and experimentally. The stability properties of the five decentralized control units have been assessed with the generalized Nyquist criterion by plotting the loci of the eigenvalues of the fully populated matrix of frequency response functions between the five error signals and five input signals to the amplifiers driving the actuators. The control performance properties have been assessed in terms of the spatially averaged response of the panel measured with a scanning laser vibrometer and the total sound power radiated measured in an anechoic room. The two analyses have shown that reductions of up to 10 dB in both vibration response and sound radiation are measured at low audio frequencies, below about 250 Hz.

  5. Decentralized Interleaving of Paralleled Dc-Dc Buck Converters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Brian B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    We present a decentralized control strategy that yields switch interleaving among parallel connected dc-dc buck converters without communication. The proposed method is based on the digital implementation of the dynamics of a nonlinear oscillator circuit as the controller. Each controller is fully decentralized, i.e., it only requires the locally measured output current to synthesize the pulse width modulation (PWM) carrier waveform. By virtue of the intrinsic electrical coupling between converters, the nonlinear oscillator-based controllers converge to an interleaved state with uniform phase-spacing across PWM carriers. To the knowledge of the authors, this work represents the first fully decentralized strategy for switch interleaving of paralleled dc-dc buck converters.

  6. Membrane bio-reactors for decentralized wastewater treatment and reuse.

    Science.gov (United States)

    Meuler, S; Paris, S; Hackner, T

    2008-01-01

    Decentralized wastewater treatment is the key to sustainable water management because it facilitates effluent (and nutrient) reuse for irrigation or as service water in households. Membrane bioreactors (MBR) can produce effluents of bathing water quality. Septic tanks can be retrofitted to MBR units. Package MBR plants for wastewater or grey water treatment are also available. Systems for decentralized treatment and reuse of domestic wastewater or grey water are also feasible for hotels, condominiums and apartment or office complexes. This paper presents the effluent qualities of different decentralized MBR applications. The high effluent quality allows infiltration even in sensitive areas or reuse for irrigation, toilet flushing and cleaning proposes in households. Due to the reusability of treated water and the possibility to design the systems for carbon reduction only, these systems can ideally and easily serve to close water and nutrient loops. IWA Publishing 2008.

  7. Decentralized Optimization for a Novel Control Structure of HVAC System

    Directory of Open Access Journals (Sweden)

    Shiqiang Wang

    2016-01-01

    Full Text Available A decentralized control structure is introduced into the heating, ventilation, and air conditioning (HVAC system to solve the high maintenance and labor cost problem in actual engineering. Based on this new control system, a decentralized optimization method is presented for sensor fault repair and optimal group control of HVAC equipment. Convergence property of the novel method is theoretically analyzed considering both convex and nonconvex systems with constraints. In this decentralized control system, traditional device is fitted with a control chip such that it becomes a smart device. The smart device can communicate and operate collaboratively with the other devices to accomplish some designated tasks. The effectiveness of the presented method is verified by simulations and hardware tests.

  8. Decentralization of multimedia content in a heterogeneous environment

    CERN Document Server

    Koskenvaara, Tuomo

    2002-01-01

    The aim of this study has been the decentralization of multimedia content in a heterogeneous environment. The environment consisted of the research networks connecting the European Organization for Nuclear Research and the Finnish University and Research Network. The European Organization for Nuclear Research produces multimedia content which can be used as studying material all over the world. The Web University pilot in the European Organization for Nuclear Research has been developing a multimedia content delivery service for years. Delivering the multimedia content requires plenty of capacity from the network infrastructure. Different content of the material can have different demands for the network. In a heterogeneous environment, like the Internet, fulfilling all the demands can be a problem. Several methods exist to improve the situation. Decentralization of the content is one of the most popular solutions. Mirroring and caching are the main methods for decentralization. Recently developed content del...

  9. The Bases of Federalism and Decentralization in Education

    Directory of Open Access Journals (Sweden)

    Carlos Ornelas

    2003-05-01

    Full Text Available This essay uses the Weberian-type ideal to define the conceptual bases of federalism and the decentralization of education. Classic federalism, ficticious federalism (corporativism, the origins and the indigenous version of the new federalism are discussed. We conclude that Mexican constitutional federalism is baroque and ambiguous. Based on theory and the experiences of various countries, bureaucratic centralism and its main characteristics are defined. As a contrast, a typology of educational decentralization is developed. Taken into account are its political, judicial and administrative definitions; a distinction is made between delegation and decentralization. It is argued that with the signing of the Agreement for the Modernization of Basic Education, the Mexican government sought to increase its legitimacy without losing control of education.

  10. Centralization but Decentralization of Computing Services: A Model for Schools of Teacher Education.

    Science.gov (United States)

    Mocciola, Michael R.

    1979-01-01

    The advantages of centralized and decentralized computing facilities within institutions of higher learning are discussed; arguments for the decentralized but not random distribution of computing facilities for schools of teacher education are presented; and the organizational structure of one "centralized but decentralized" computing…

  11. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  12. High quality (InNb)0.1Ti0.9O2 single crystal grown using optical floating zone method

    Science.gov (United States)

    Liu, Ziyi; Song, Yongli; Wang, Xianjie; Su, Yantao; Liu, Zhiguo; Sui, Yu

    2016-07-01

    A crack-free (InNb)0.1Ti0.9O2 single crystal of 4 mm in diameter and 30 mm in length was successfully grown by the optical floating zone method. The polycrystalline feed and seed rods for growing the (InNb)0.1Ti0.9O2 single crystal were prepared by solid-state reaction method. The oxygen partial pressure significantly affected the crystal quality of the material. As shown in reflecting polarizing microphotographs, crystals grown in air have fewer grain boundaries than those grown in pure oxygen; some air-grown crystals are completely free of grain boundaries. Compared to pure TiO2 crystal, the (Nb+In) co-doped TiO2 crystal required a lower growth rate of 5 mm/h to ensure high quality.

  13. An Evaluation of Decentralization in a Large School District.

    Science.gov (United States)

    Silberman, Harry F.

    In October 1975, the School Board of the Los Angeles Unified School District appointed a Citizen's Committee to conduct an appraisal of the management of the school district. This Citizen's Management Review Committee (CMRC) organized itself into five subcommittees: Management, Policy, Personnel, Budget, and Decentralization. The Decentralization…

  14. Centralized and decentralized control of structural vibration and sound radiation

    NARCIS (Netherlands)

    Engels, W.P.; Baumann, O.N.; Elliott, S.J.; Fraanje, P.R.

    2006-01-01

    This paper examines the performance of centralized and decentralized feedback controllers on a plate with multiple colocated velocity sensors and force actuators. The performance is measured by the reduction in either kinetic energy or sound radiation, when the plate is excited with a randomly distr

  15. Users' perspectives on decentralized rural water services in Tanzania

    NARCIS (Netherlands)

    Masanyiwa, Z.S.; Niehof, A.; Termeer, C.J.A.M.

    2015-01-01

    This article examines the impact of decentralization reforms on improving access to domestic water supply in the rural districts of Kondoa and Kongwa, Tanzania, using a users' and a gender perspective. The article addresses the question whether and to what extent the delivery of gender-sensitive wat

  16. Decentralized Receding Horizon Control and Coordination of Autonomous Vehicle Formations

    NARCIS (Netherlands)

    Keviczky, T.; Borelli, F.; Fregene, K.; Godbole, D.; Bals, G.J.

    2008-01-01

    This paper describes the application of a novel methodology for high-level control and coordination of autonomous vehicle teams and its demonstration on high-fidelity models of the organic air vehicle developed at Honeywell Laboratories. The scheme employs decentralized receding horizon controllers

  17. Reaction Diffusion and Chemotaxis for Decentralized Gathering on FPGAs

    Directory of Open Access Journals (Sweden)

    Bernard Girau

    2009-01-01

    and rapid simulations of the complex dynamics of this reaction-diffusion model. Then we describe the FPGA implementation of the environment together with the agents, to study the major challenges that must be solved when designing a fast embedded implementation of the decentralized gathering model. We analyze the results according to the different goals of these hardware implementations.

  18. A Decentralized Storage Strategy for Residential Feeders with Photovoltaics

    DEFF Research Database (Denmark)

    Marra, Francesco; Yang, Guangya; Træholt, Chresten

    2014-01-01

    This paper proposes a decentralized voltage support strategy for LV residential feeders with high roof-top PV capacity installed. The proposed strategy is capable of increasing the local consumption at private households with PV during high generation periods, by the use of locally controlled...

  19. Decentralization and Faculty Ownership: Keys to a Successful Assessment Strategy.

    Science.gov (United States)

    Foley, Terrence; And Others

    In an effort to prepare for a North Central Association accreditation visit, Henry Ford Community College (HFCC), in Michigan, developed and implemented a decentralized and faculty-driven assessment plan. First, a faculty member was assigned to begin the groundwork for the assessment plan and an Instructional Assessment Committee was formed to…

  20. Dynamical orders of decentralized H-infinity controllers

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.H.

    1999-01-01

    The problem of decentralized control is addressed, i.e. the problem of designing a controller where each control input is allowed to use only some of the measurements. It is shown that, for such problems, there does not always exist a sequence of controllers of bounded order which obtains near-op...

  1. Contesting sharia : state law, decentralization and Minangkabau custom

    NARCIS (Netherlands)

    Huda, Yasrul

    2013-01-01

    This book explains how Sharia, commonly called Perda Sharia (Sharia by-law) in Indonesia, was legislated on the provincial, regional and municipal level in West Sumatra. This process began after the government started a decentralization policy in 2000. Although the law of local autonomy prescribes

  2. Taming instabilities in power grid networks by decentralized control

    Science.gov (United States)

    Schäfer, B.; Grabow, C.; Auer, S.; Kurths, J.; Witthaut, D.; Timme, M.

    2016-05-01

    Renewables will soon dominate energy production in our electric power system. And yet, how to integrate renewable energy into the grid and the market is still a subject of major debate. Decentral Smart Grid Control (DSGC) was recently proposed as a robust and decentralized approach to balance supply and demand and to guarantee a grid operation that is both economically and dynamically feasible. Here, we analyze the impact of network topology by assessing the stability of essential network motifs using both linear stability analysis and basin volume for delay systems. Our results indicate that if frequency measurements are averaged over sufficiently large time intervals, DSGC enhances the stability of extended power grid systems. We further investigate whether DSGC supports centralized and/or decentralized power production and find it to be applicable to both. However, our results on cycle-like systems suggest that DSGC favors systems with decentralized production. Here, lower line capacities and lower averaging times are required compared to those with centralized production.

  3. Contesting sharia : state law, decentralization and Minangkabau custom

    NARCIS (Netherlands)

    Huda, Yasrul

    2013-01-01

    This book explains how Sharia, commonly called Perda Sharia (Sharia by-law) in Indonesia, was legislated on the provincial, regional and municipal level in West Sumatra. This process began after the government started a decentralization policy in 2000. Although the law of local autonomy prescribes t

  4. Agent-Based Decentralized Control Method for Islanded Microgrids

    DEFF Research Database (Denmark)

    Li, Qiang; Chen, Feixiong; Chen, Minyou;

    2016-01-01

    In this paper, an agent-based decentralized control model for islanded microgrids is proposed, which consists of a two-layer control structure. The bottom layer is the electrical distribution microgrid, while the top layer is the communication network composed of agents. An agent is regarded as a...

  5. Formula Funding of Schools, Decentralization and Corruption: A Comparative Analysis

    Science.gov (United States)

    Levacic, Rosalind; Downes, Peter

    2004-01-01

    This study sets out to examine the relationship, if any, between the decentralization of funding for schools and the prevalence of corruption and fraud. It is based upon work carried out in four countries: Australia (the State of Victoria), the United Kingdom (specifically England), Poland (with particular reference to two cities) and Brazil…

  6. Overview on Decentralized Establishment of Multi-lateral Collaborations

    NARCIS (Netherlands)

    Wombacher, A.; Hemmje, M.; Niedere, C.; Risse, T.

    2005-01-01

    Service oriented architectures facilitate loosely coupled collaborations, which are established in a decentralized way. One challenge for such collaborations is to guarantee consistency, that is, fulfillment of all constraints of individual services and deadlock-freeness. This paper presents an over

  7. Centralization and Decentralization of Schools' Physical Facilities Management in Nigeria

    Science.gov (United States)

    Ikoya, Peter O.

    2008-01-01

    Purpose: This research aims to examine the difference in the availability, adequacy and functionality of physical facilities in centralized and decentralized schools districts, with a view to making appropriate recommendations to stakeholders on the reform programmes in the Nigerian education sector. Design/methodology/approach: Principals,…

  8. Users' perspectives on decentralized rural water services in Tanzania

    NARCIS (Netherlands)

    Masanyiwa, Z.S.; Niehof, A.; Termeer, C.J.A.M.

    2015-01-01

    This article examines the impact of decentralization reforms on improving access to domestic water supply in the rural districts of Kondoa and Kongwa, Tanzania, using a users' and a gender perspective. The article addresses the question whether and to what extent the delivery of gender-sensitive wat

  9. Centralization versus Decentralization in Educational Administration: Regional Issues.

    Science.gov (United States)

    Bray, Mark

    1991-01-01

    Outlines strategies to reduce inequities in numerous counties, focusing on the distribution of financial and human resources. Also addresses issues of diversity and conformity in education systems. Reduction of regional imbalances does not necessarily require imposition of uniformity, but the diversity caused by decentralization is not always…

  10. Decentralized School vs. Centralized School. Investigation No. 3.

    Science.gov (United States)

    Paseur, C. Herbert

    A report is presented of a comparative investigation of a decentralized and a centralized school facility. Comparative data are provided regarding costs of the facilities, amount of educational area provided by the facilities, and types of educational areas provided. Evaluative comments are included regarding cost savings versus educational…

  11. Generalized Fibonacci zone plates

    CERN Document Server

    Ke, Jie; Zhu, Jianqiang

    2015-01-01

    We propose a family of zone plates which are produced by the generalized Fibonacci sequences and their axial focusing properties are analyzed in detail. Compared with traditional Fresnel zone plates, the generalized Fibonacci zone plates present two axial foci with equal intensity. Besides, we propose an approach to adjust the axial locations of the two foci by means of different optical path difference, and further give the deterministic ratio of the two focal distances which attributes to their own generalized Fibonacci sequences. The generalized Fibonacci zone plates may allow for new applications in micro and nanophotonics.

  12. Association between multifocal soft contact lens decentration and visual performance

    Directory of Open Access Journals (Sweden)

    Fedtke C

    2016-06-01

    Full Text Available Cathleen Fedtke,1 Klaus Ehrmann,1,2 Varghese Thomas,1 Ravi C Bakaraju1,2 1The Brien Holden Vision Institute, Clinical Trial Research Centre, 2School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW, Australia Purpose: The aim of this study was to assess the association between decentration of several commercial multifocal soft contact lenses (MFCLs and various objective and subjective visual performance variables in presbyopic and non-presbyopic participants. Materials and methods: All presbyopic (age >40 years, near add ≥+1.25 D and non-presbyopic (age ≥18 years, no near add requirements, spherical equivalent ≤-0.50 D participants were each fitted bilaterally with six and two MFCLs (test lens, respectively, and with one single vision lens (control lens. Lens decentration, ie, the x- and y-differences between the contact lens and pupil centers, was objectively determined. Third-order aberrations were measured and compared. Visual performance (high- and low-contrast acuities and several subjective variables was analyzed for any associations (Pearson’s correlation, r with MFCL decentration. Results: A total of 17 presbyopic (55.1±6.9 years and eight non-presbyopic (31.0±3.3 years participants completed the study. All lenses displayed a temporal–inferior decentration (x=-0.36±0.29 mm, y=-0.28±0.28 mm, mean ± SD. Compared to the control, a significant inferior decentration was found for the Proclear® MFCL Near lens in both groups (ypresbyopic =-0.26 mm, ynon-presbyopic =-0.70 mm and for the Proclear® MFCL Distance lens in the non-presbyopic group (ynon-presbyopic =-0.69 mm. In both groups, lens-induced vertical coma (C(3, -1 was, by at least tenfold, significantly more positive for the Proclear® MFCL Distance lens and significantly more negative for the Proclear® MFCL Near lens. In the presbyopic group, the correlation of total MFCL decentration with vision variables was weak (r<|0

  13. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  14. U-Form vs. M-Form: How to Understand Decision Autonomy Under Healthcare Decentralization?

    Science.gov (United States)

    Bustamante, Arturo Vargas

    2016-01-01

    For more than three decades healthcare decentralization has been promoted in developing countries as a way of improving the financing and delivery of public healthcare. Decision autonomy under healthcare decentralization would determine the role and scope of responsibility of local authorities. Jalal Mohammed, Nicola North, and Toni Ashton analyze decision autonomy within decentralized services in Fiji. They conclude that the narrow decision space allowed to local entities might have limited the benefits of decentralization on users and providers. To discuss the costs and benefits of healthcare decentralization this paper uses the U-form and M-form typology to further illustrate the role of decision autonomy under healthcare decentralization. This paper argues that when evaluating healthcare decentralization, it is important to determine whether the benefits from decentralization are greater than its costs. The U-form and M-form framework is proposed as a useful typology to evaluate different types of institutional arrangements under healthcare decentralization. Under this model, the more decentralized organizational form (M-form) is superior if the benefits from flexibility exceed the costs of duplication and the more centralized organizational form (U-form) is superior if the savings from economies of scale outweigh the costly decision-making process from the center to the regions. Budgetary and financial autonomy and effective mechanisms to maintain local governments accountable for their spending behavior are key decision autonomy variables that could sway the cost-benefit analysis of healthcare decentralization. PMID:27694684

  15. An impact assessment of sea ice on ocean optics observations in the marginal ice zone of the Arctic

    Institute of Scientific and Technical Information of China (English)

    LI Tao; ZHAO Jinping

    2014-01-01

    Diffuse attenuation coefficient (DAC) of sea water is an important parameter in ocean thermodynamics and biology, reflecting the absorption capability of sea water in different layers. In the Arctic Ocean, however, sea ice affects the radiance/irradiance measurements of upper ocean, which results in obvious errors in the DAC calculation. To better understand the impacts of sea ice on the ocean optics observations, a series ofin situ experiments were carried out in the summer of 2009 in the southern Beaufort Sea. Observational results show that the profiles of spectral diffuse attenuation coefficients of seawater near ice cover within upper surface of 50 m were not contaminated by the sea ice with a solar zenith angle of 55°, relative azimuth angle of 110°≤φ≤115° and horizontal distance between the sensors and ice edge of greater than 25 m. Based on geometric optics theory, the impact of ice cover could be avoided by adjusting the relative solar azimuth angle in a particular distance between the instrument and ice. Under an overcast sky, ice cover being 25 m away from sensors did not affect the profiles of spectral DACs within the upper 50 m either. Moreover, reli-able spectral DACs of seawater could be obtained with sensors completely covered by sea ice.

  16. A hybrid OFDM-TDM architecture with decentralized dynamic bandwidth allocation for PONs.

    Science.gov (United States)

    Cevik, Taner

    2013-01-01

    One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand.

  17. A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs

    Science.gov (United States)

    Cevik, Taner

    2013-01-01

    One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand. PMID:24194684

  18. High-pressure optical floating-zone growth of Li(Mn,Fe)PO4 single crystals

    Science.gov (United States)

    Neef, Christoph; Wadepohl, Hubert; Meyer, Hans-Peter; Klingeler, Rüdiger

    2017-03-01

    Mm-sized LiMn1-xFexPO4 single crystals with 0 ⩽ x ⩽ 1 were grown by means of the traveling floating-zone technique at elevated Argon pressure of 30 bar. For the various doping levels, the growth process was optimized with respect to the composition-dependant effective light absorption and transparency of the materials. A convex crystal/melt interface, determined by the angle of incident light, was identified to be particularly crucial for a successful growth. The resulting large single crystalline grains are stoichiometric. Structure refinement shows that lattice parameters as well as the atomic positions and bond lengths linearly depend on the Mn:Fe-ratio. Oriented cuboidal samples with several mm3 of volume were used for magnetic studies which imply an antiferromagnetic ground state for all compositions. The Néel-temperature changes from TN = 32.5(5) K in LiMnPO4 to 49.5(5) K in LiFePO4 while the easy magnetic axis in the ordered phase flips from the crystallographic a- to the b-axis upon Fe-doping of x < 0.2 .

  19. Experimental quantification of solute transport through the vadose zone under dynamic boundary conditions with dye tracers and optical methods.

    Science.gov (United States)

    Cremer, Clemens; Neuweiler, Insa

    2017-04-01

    transport through the material interface which differs between the stationary (unilateral) and dynamic cases (bilateral). This qualitative observation is confirmed by breakthrough curves for dynamic experiments which generally show the trend of faster initial breakthrough and increased tailing when compared to stationary infiltration results. Literature Cremer, C.J.M., I. Neuweiler, M. Bechtold, J. Vanderborght (2016): Solute Transport in Heterogeneous Soil with Time-Dependent Boundary Conditions, Vadose Zone Journal 15 (6) DOI: 10.2136/vzj2015.11.0144

  20. Model-Based Design of Tree WSNs for Decentralized Detection.

    Science.gov (United States)

    Tantawy, Ashraf; Koutsoukos, Xenofon; Biswas, Gautam

    2015-08-20

    The classical decentralized detection problem of finding the optimal decision rules at the sensor and fusion center, as well as variants that introduce physical channel impairments have been studied extensively in the literature. The deployment of WSNs in decentralized detection applications brings new challenges to the field. Protocols for different communication layers have to be co-designed to optimize the detection performance. In this paper, we consider the communication network design problem for a tree WSN. We pursue a system-level approach where a complete model for the system is developed that captures the interactions between different layers, as well as different sensor quality measures. For network optimization, we propose a hierarchical optimization algorithm that lends itself to the tree structure, requiring only local network information. The proposed design approach shows superior performance over several contentionless and contention-based network design approaches.

  1. Model-Based Design of Tree WSNs for Decentralized Detection

    Directory of Open Access Journals (Sweden)

    Ashraf Tantawy

    2015-08-01

    Full Text Available The classical decentralized detection problem of finding the optimal decision rules at the sensor and fusion center, as well as variants that introduce physical channel impairments have been studied extensively in the literature. The deployment of WSNs in decentralized detection applications brings new challenges to the field. Protocols for different communication layers have to be co-designed to optimize the detection performance. In this paper, we consider the communication network design problem for a tree WSN. We pursue a system-level approach where a complete model for the system is developed that captures the interactions between different layers, as well as different sensor quality measures. For network optimization, we propose a hierarchical optimization algorithm that lends itself to the tree structure, requiring only local network information. The proposed design approach shows superior performance over several contentionless and contention-based network design approaches.

  2. THE ROLE OF DECENTRALIZATION FOR EFFICIENT PUBLIC ADMINISTRATION

    Directory of Open Access Journals (Sweden)

    Emilia Cornelia STOICA

    2011-12-01

    Full Text Available A modern public administration is focused on meeting the needs of citizens, provides comprehensive information on matters concerning their community with full cooperate with citizens and public control exercised carefully and neutral on the achievement of public services.Modern public administration seeks to determine how greater participation of civil society in decision-making process that local corporate and also provides administrative transparency and direct communication with citizens as possible. In this sense, decentralization of public administration, involving public services decentralization and strengthening local autonomy in administrative and financial point of view, realizing and working to enhance local involvement in management issues they face and to build policy own - in the context of overall national economic and social development - to increase economic performance and to improve the social life of local citizens by defining and local responsibilities regarding local services and financial performance, for their accomplishment.

  3. Delay-dependent decentralized H∞ filtering for uncertain interconnected systems

    Institute of Scientific and Technical Information of China (English)

    Chen Ning; Gui Weihua; Zhang Xiaofeng

    2008-01-01

    This article considers delay dependent decentralized H∞ filtering for a class of uncertain intercon nected systems,where the uncertainties are assumed to be time varying and satisfy the norm-bounded conditions.First,combining the Lyapunov-Krasovskii functional approach and the delay integral inequality of matrices,a sufficient condition of the existence of the robust decentralized H∞ filter is derived,which makes the error systems asymptotically stable and satisfies the H∞ norm of the transfer function from noise input to error output less than the specified up-bound on the basis of the form of uncertainties.Then,the above sufficient condition is transformed to a system of easily solvable LMIs via a series of equivalent transformation.Finally,the numerical simulation shows the efficiency of the main results.

  4. Decentralized Disturbance Accommodation with Limited Plant Model Information

    CERN Document Server

    Farokhi, F; Johansson, K H

    2011-01-01

    The design of optimal disturbance accommodation and servomechanism controllers with limited plant model information is considered in this paper. Their closed-loop performance are compared using a performance metric called competitive ratio which is the worst-case ratio of the cost of a given control design strategy to the cost of the optimal control design with full model information. It was recently shown that when it comes to designing optimal centralized or partially structured decentralized state-feedback controllers with limited model information, the best control design strategy in terms of competitive ratio is a static one. This is true even though the optimal structured decentralized state-feedback controller with full model information is dynamic. In this paper, we show that, in contrast, the best limited model information control design strategy for the disturbance accommodation problem gives a dynamic controller. We find an explicit minimizer of the competitive ratio and we show that it is undomina...

  5. Decentralized energy planning and consensus in energy policy

    Energy Technology Data Exchange (ETDEWEB)

    Wilbanks, T. J.

    1980-05-02

    This paper explores the following three propositions and their relationships: (1) that, in our pluralistic policymaking environment, we cannot solve our nation's energy problems unless we can reach agreement among a diverse group of interested parties about specific actions; (2) that, short of a manifest emergency, such a consensus is difficult to reach unless the scale of the decision-making unit is relatively small; and therefore (3) that one of the keys to an effective energy policy in the United states is to rely heavily on local and regional energy planning and decision-making. First, the paper reviews our problem of irresolution and its roots, and it summaries the policy options for resolving it. Then it explores one of those options, decentralized planning, in a little more detail. Finally, it offers some speculations about the viability of a decentralized approach to energy planninng.

  6. Constructed wetlands as sustainable ecotechnologies in decentralization practices: a review.

    Science.gov (United States)

    Valipour, Alireza; Ahn, Young-Ho

    2016-01-01

    Recently, a range of novel and cost-effective engineered wetland technologies for decentralization practices of domestic wastewater treatment have been developed with ecological process modification, the use of functionalized plants, and advanced biofilm formation. However, selecting the one that can be more appreciated for on-site sanitation is still uncertain. This paper reviews the role of plants, media materials, microorganisms, and oxygen transfer in domestic wastewater purification through constructed wetlands (CWs). The effectiveness of traditional and recently developed CWs and the necessity of an induced biofilm attachment surface (BAS) in these systems for the treatment of domestic sewage are presented. This review also elucidates the idea of CWs for domestic wastewater characteristics highly stressed by total dissolved solids and the adaptive strategies in mitigating the cold climate impacts on their efficiencies. Further research needed to enhance the stability and sustainability of CWs is highlighted. By a more advanced investigation, BAS CWs can be specified as an ideal treatment process in decentralization.

  7. Decentralized Neural Backstepping Control Applied to a Robot Manipulator

    Directory of Open Access Journals (Sweden)

    Ramon Garcia-Hernandez

    2013-01-01

    Full Text Available This paper presents a discrete‐time decentralized control scheme for trajectory tracking of a two degrees of freedom (DOF robot manipulator. A high order neural network (HONN is used to approximate a decentralized control law designed by the backstepping technique as applied to a block strict feedback form (BSFF. The weights for each neural network are adapted online by an extended Kalman filter training algorithm. The motion for each joint is controlled independently using only local angular position and velocity measurements. The stability analysis for the closed‐loop system via the Lyapunov approach is included. Finally, the real‐time results show the feasibility of the proposed control scheme using a robot manipulator.

  8. A Decentralized Architecture for Enforcing Privacy in Online Social Networks

    CERN Document Server

    Jahid, Sonia; Mittal, Prateek; Borisov, Nikita; Kapadia, Apu

    2011-01-01

    A multitude of privacy breaches, both accidental and malicious, have prompted users to distrust centralized providers of online social networks (OSNs) and investigate decentralized solutions. We examine the design of a fully decentralized (peer-to-peer) OSN, with a special focus on privacy and security. In particular, we wish to protect the confidentiality, integrity, and availability of user content and the privacy of user relationships. We propose DECENT, an architecture for OSNs that uses a distributed hash table to store user data, and features cryptographic protections for confidentiality and integrity, as well as support for flexible attribute policies and fast revocation. DECENT ensures that neither data nor social relationships are visible to unauthorized users and provides availability through replication and authentication of updates. We evaluate DECENT through simulation and experiments on the PlanetLab network and show that DECENT is able to replicate the main functionality of current centralized ...

  9. Learning Equilibria with Partial Information in Decentralized Wireless Networks

    CERN Document Server

    Rose, Luca; Lasaulce, Samson; Debbah, Mérouane

    2011-01-01

    In this article, a survey of several important equilibrium concepts for decentralized networks is presented. The term decentralized is used here to refer to scenarios where decisions (e.g., choosing a power allocation policy) are taken autonomously by devices interacting with each other (e.g., through mutual interference). The iterative long-term interaction is characterized by stable points of the wireless network called equilibria. The interest in these equilibria stems from the relevance of network stability and the fact that they can be achieved by letting radio devices to repeatedly interact over time. To achieve these equilibria, several learning techniques, namely, the best response dynamics, fictitious play, smoothed fictitious play, reinforcement learning algorithms, and regret matching, are discussed in terms of information requirements and convergence properties. Most of the notions introduced here, for both equilibria and learning schemes, are illustrated by a simple case study, namely, an interfe...

  10. Decentralized adaptive control designs and microstrip antennas for smart structures

    Science.gov (United States)

    Khorrami, Farshad; Jain, Sandeep; Das, Nirod K.

    1996-05-01

    Smart structures lend themselves naturally to a decentralized control design framework, especially with adaptation mechanisms. The main reason being that it is highly undesirable to connect all the sensors and actuators in a large structure to a central processor. It is rather desirable to have local decision-making at each smart patch. Furthermore, this local controllers should be easily `expandable' to `contractible.' This corresponds to the fact that addition/deletion of several smart patches should not require a total redesign of the control system. The decentralized control strategies advocated in this paper are of expandable/contractible type. On another front, we are considering utilization of micro-strip antennas for power transfer to and from smart structures. We have made preliminary contributions in this direction and further developments are underway. These approaches are being pursued for active vibration damping and noise cancellation via piezoelectric ceramics although the methodology is general enough to be applicable to other type of active structures.

  11. Decentralized ventilation systems; Flere aggregater billigere enn ett

    Energy Technology Data Exchange (ETDEWEB)

    Vidnes, Harald H.

    2000-07-01

    Decentralized ventilation systems may be the solution of the future. The article discusses how they can be economically attractive. They can also easily be designed to meet the needs of individual users. As an illustration, the article discusses a sixteen-floor office building with a canteen on the ground floor. Two cases are compared. In one case, four aggregates are installed in a technical room on the roof. These have rotary heat recovery, heating and refrigerating batteries, fans, dampers and filters. The cantina aggregate is placed in the basement, but of the same design as the other aggregates. The other case replaces the four aggregates of the first case with seventeen compact aggregates, one for each floor. They communicate through supervisory control. The decentralized system is found to be superior, although there are more aggregates to maintain.

  12. Analysis of Decentralized Control for Absorption Cycle Heat Pumps

    DEFF Research Database (Denmark)

    Vinther, Kasper; Just Nielsen, Rene; Nielsen, Kirsten Mølgaard

    2015-01-01

    Email Print Request Permissions This paper investigates decentralized control structures for absorption cycle heat pumps and a dynamic nonlinear model of a single-effect LiBr-water absorption system is used as case study. The model has four controllable inputs, which can be used to stabilize...... the operation of the heat pump under different load conditions. Different feasible input-output pairings are analyzed by computation of relative gain array matrices and scaled condition numbers, which indicate the best pairing choice and the potential of each input-output set. Further, it is possible...... to minimize the effect of cross couplings and improve stability with the right pairing of input and output. Simulation of selected candidate input-output pairings demonstrate that decentralized control can provide stable operation of the heat pump....

  13. Decentralized Economic Dispatch Scheme With Online Power Reserve for Microgrids

    DEFF Research Database (Denmark)

    Nutkani, I. U.; Loh, Poh Chiang; Wang, P.

    2017-01-01

    Decentralized economic operation schemes have several advantages when compared with the traditional centralized management system for microgrids. Specifically, decentralized schemes are more flexible, less computationally intensive, and easier to implement without relying on communication......-load generation costs. Although the prioritization works well with some generation costs saved, its reliance on only the DG no-load generation costs does not allow it to operate well under certain conditions. This paper thus presents a more comprehensive economic dispatch scheme, which considers the DG generation...... costs, their power ratings, and other necessary constraints, before deciding the DG dispatch priorities and droop characteristics. The proposed scheme also allows online power reserve to be set and regulated within the microgrid. This, together with the generation cost saved, has been verified...

  14. Combining centralization and decentralization in Danish Public Administration

    DEFF Research Database (Denmark)

    Chatzopoulou, Sevasti; Poulsen, Birgitte

    2016-01-01

    and the general principles of centralization and decentralization in the Danish Administrative system are presented. This is followed by the territorial division of the different levels of administrative structures, and their division of competences (decision and implementation). The Danish civil service and its......This chapter presents the structure and competences of the Danish administrative system and the significant changes that were introduced under the latest reform in 2007 and led to both centralization and decentralization. The chapter is divided in five sections. First, the recent history...... particular characteristics are explained, followed by the most recent reform that determines the coordination among the three levels of Danish Public Administration. The financial distribution of resources from the national budget among the different levels and how this is decided is then discussed...

  15. The effect of temperature and pressure on optical absorption spectra of transition zone minerals - Implications for the radiative conductivity of the Earth's interior

    Science.gov (United States)

    Thomas, S.; Jacobsen, S. D.; Bina, C. R.; Goncharov, A. F.; Frost, D. J.; McCammon, C. A.

    2010-12-01

    Optical absorption spectra of high-pressure minerals can be used as indirect tools to calculate radiative conductivities of the Earth’s interior [e.g., 1]. Recent high-pressure studies imply that e.g. ringwoodite, γ-(Mg,Fe)2SiO4, does not become opaque in the near infrared and visible region, as previously assumed, but remains transparent to 21.5 GPa [2]. Therefore, it has been concluded that radiative heat transfer does not necessarily become blocked at high pressures of the mantle and ferromagnesian minerals actually might contribute to the heat flow in the Earth’s interior [2]. However, experimental results on temperature effects on radiative heat transfer are not available. We studied the effect of both, pressure and temperature, on the optical absorption of hydrous Fe-bearing ringwoodite, γ-(Mg,Fe)2SiO4, and hydrous Fe-bearing wadsleyite, β-(Mg,Fe)2SiO4, which are the main components of the Earth’s transition zone. Gem-quality single-crystals were synthesized at 18 GPa and 1400 °C in a 5000t multianvil apparatus. Crystals were analyzed by Mössbauer and Raman spectroscopy, electron microprobe analysis and single-crystal X-ray diffraction. For optical absorption measurements in the IR - VIS - UV spectral range (400 - 50000 cm-1) 50 µm sized single-crystals of ringwoodite and wadsleyite were double polished to thicknesses of 13 µm and 18 µm, respectively, and loaded in resistively heated diamond-anvil cells with argon as pressure medium. After taking measurements at high pressure and room temperature, ringwoodite was studied at 26 GPa up to 650 °C and wadsleyite spectra were recorded at 16 GPa up to 450 °C. At ambient pressure the absorption spectrum of ringwoodite reveals a crystal field band (Fe2+) at 12075 cm-1, an intervalence charge transfer band (Fe2+ to Fe3+) at 16491 cm-1, and an absorption edge due to ligand-metal charge transfer close to 30000 cm-1. The wadsleyite spectrum is characterized by a similar absorption edge in the VIS-UV range

  16. An approach to decentralizing search, using stigmergic hyperlinks

    OpenAIRE

    Marques, Artur; Figueiredo,José

    2010-01-01

    A stigmergic hyperlink, or “stigh”, is an object that looks and behaves like a regular HTML hyperlink, but runs at the server side. A system of stighs displays interesting emergent behaviors, of some complexity, but a stigh alone is very simple: it has a life attribute, only reinforced when users click it, and methods to provide meta-information about its destination. We reason that stigmergic hyperlinks could support a more decentralized approach to the Web search problem, particularly for a...

  17. Logical Time for Decentralized Control of Material Handling Systems

    OpenAIRE

    Seibold, Zäzilia

    2016-01-01

    The fourth industrial revolution aims to transform production systems. In this work, Logical Time which is a control principle for distributed systems is transferred to material handling systems with decentralized control. The GridSorter, a modular sorter with grid-like structure, is chosen as showcase system. The system is proven to be deadlock-free and is robust against varying transport times. The time-window-based route reservation process is described as Iterative Deepening A*.

  18. Decentralization Policy and Effectiveness of Local Government Organization in Indonesia

    OpenAIRE

    Abdullah, Muh. Tang

    2014-01-01

    In the era of decentralization policy implementation, the local bureaucracy (Indonesian: Organisasi Perangkat Daerah) has strategic position in the local government system. It is so as the instruments and the fundamental base of the local government in implementing its affairs and as the media to realize the vision, mission, and the objectives of local government. The successful of local government is determined by the effectiveness of the local bureaucracy. This study aims to examine the eff...

  19. DECENTRALIZED THERMOPHILIC BIOHYDROGEN: A MORE EFFICIENT AND COST EFFECTIVE PROCESS

    OpenAIRE

    Sani, Rajesh.K.; Rajesh V. Shende; Sudhir Kumar; Aditya Bhalla

    2011-01-01

    Nonfood lignocellulosic biomass is an ideal substrate for biohydrogen production. By avoiding pretreatment steps (acid, alkali, or enzymatic), there is potential to make the process economical. Utilization of regional untreated lignocellulosic biomass by cellulolytic and fermentative thermophiles in a consolidated mode using a single reactor is one of the ways to achieve economical and sustainable biohydrogen production. Employing these potential microorganisms along with decentralized biohyd...

  20. Decentralized-feedback pole placement of linear systems

    Science.gov (United States)

    Wang, X.; Martin, C. F.; Gilliam, D.; Byrnes, C. I.

    1992-01-01

    A projectile product spaces model is used to analyze decentralized systems. The degree of the pole placement map is computed. The conditions under which the degree is odd are also given. Twin lift systems are studied. It is proved that the poles of a twin lift system can be assigned to any values by local static and local dynamic feedback laws if and only if the system is jointly controllable.

  1. Decentralized Bayesian reinforcement learning for online agent collaboration

    OpenAIRE

    Teacy, W.T.L.; G. Chalkiadakis; Farinelli, A.; Rogers, A.; Jennings, N.R.; McClean, S.; Parr, G.

    2012-01-01

    Solving complex but structured problems in a decentralized manner via multiagent collaboration has received much attention in recent years. This is natural, as on one hand, multiagent systems usually possess a structure that determines the allowable interactions among the agents; and on the other hand, the single most pressing need in a cooperative multiagent system is to coordinate the local policies of autonomous agents with restricted capabilities to serve a system-wide goal. The presence ...

  2. 基于区域扩展的绿色业务量疏导算法%Green traffic grooming in zone-based scalable optical networks

    Institute of Scientific and Technical Information of China (English)

    王汝言; 徐印; 吴大鹏; 彭海英

    2012-01-01

    In the view of high blocking probability of Traditional Green traffic grooming algorithm in optical networks, a Green traffic grooming in zone-based scalable optical networks is proposed and studied in this paper. On the basis of W + 5 Auxiliary Graph Model, generating an auxiliary graph which only contains parts of network nodes, it is possible to find a suitable and shorter route by flexibility to expand the auxiliary graph. Simulation results show that in comparison with the Traditional Green traffic grooming algorithm, the proposed algorithm can effectively reduce the blocking probability and achieve the lowest average power consumption when traffic load is relatively high.%针对全光网络中传统绿色业务量疏导算法阻塞率高的性能缺陷,提出一种全光网络中基于区域扩展的绿色业务量疏导算法.该算法基于W+5分层图模型,生成一个仅包含部分网络节点的区域性辅助图,通过灵活扩展辅助图的方式,寻找最佳路径,避免了形成过长路由.仿真结果表明,与传统绿色业务量疏导算法相比,基于区域扩展的绿色业务量疏导算法能够有效地降低业务阻塞率,并且在高负载的情况下,网络的平均功耗最低.

  3. Game-Based Virtual Worlds as Decentralized Virtual Activity Systems

    Science.gov (United States)

    Scacchi, Walt

    There is widespread interest in the development and use of decentralized systems and virtual world environments as possible new places for engaging in collaborative work activities. Similarly, there is widespread interest in stimulating new technological innovations that enable people to come together through social networking, file/media sharing, and networked multi-player computer game play. A decentralized virtual activity system (DVAS) is a networked computer supported work/play system whose elements and social activities can be both virtual and decentralized (Scacchi et al. 2008b). Massively multi-player online games (MMOGs) such as World of Warcraft and online virtual worlds such as Second Life are each popular examples of a DVAS. Furthermore, these systems are beginning to be used for research, deve-lopment, and education activities in different science, technology, and engineering domains (Bainbridge 2007, Bohannon et al. 2009; Rieber 2005; Scacchi and Adams 2007; Shaffer 2006), which are also of interest here. This chapter explores two case studies of DVASs developed at the University of California at Irvine that employ game-based virtual worlds to support collaborative work/play activities in different settings. The settings include those that model and simulate practical or imaginative physical worlds in different domains of science, technology, or engineering through alternative virtual worlds where players/workers engage in different kinds of quests or quest-like workflows (Jakobsson 2006).

  4. The Multi-faceted Debate on Decentralization and Collective Welfare

    Directory of Open Access Journals (Sweden)

    Sandra Gomes

    2010-12-01

    Full Text Available Studies on the relation between decentralization reforms and the performance of governments and their policies have presented a myriad of theoretical developments but inconclusive results on the empirically verifiable effects of these propositions. Many of the reviews carried out thus far in this field merely criticize these propositions without proposing alternatives for analysis. This article presents a review of this debate in a very specific way: it selects the propositions that points towards the causal factors explaining government’s responsiveness to its citizens. Four types of interpretations are discussed: 1 allocative efficiency theories of fiscal decentralization, 2 the multiple dimensions of decentralization, 3 the institutional design of reforms, and 4 the qualitative aspects of governance. Despite the observed divergences in the use of concepts, analytical preoccupations and in relation to the empirical operationalization of variables, this article points to a series of hypotheses that could be extracted from this debate and that could be the object of an empirical test.

  5. Evolutionary Concepts for Decentralized Air Traffic Flow Management

    Science.gov (United States)

    Adams, Milton; Kolitz, Stephan; Milner, Joseph; Odoni, Amedeo

    1997-01-01

    Alternative concepts for modifying the policies and procedures under which the air traffic flow management system operates are described, and an approach to the evaluation of those concepts is discussed. Here, air traffic flow management includes all activities related to the management of the flow of aircraft and related system resources from 'block to block.' The alternative concepts represent stages in the evolution from the current system, in which air traffic management decision making is largely centralized within the FAA, to a more decentralized approach wherein the airlines and other airspace users collaborate in air traffic management decision making with the FAA. The emphasis in the discussion is on a viable medium-term partially decentralized scenario representing a phase of this evolution that is consistent with the decision-making approaches embodied in proposed Free Flight concepts for air traffic management. System-level metrics for analyzing and evaluating the various alternatives are defined, and a simulation testbed developed to generate values for those metrics is described. The fundamental issue of modeling airline behavior in decentralized environments is also raised, and an example of such a model, which deals with the preservation of flight bank integrity in hub airports, is presented.

  6. Land use and environmental impacts of decentralized solar energy use

    Energy Technology Data Exchange (ETDEWEB)

    Twiss, R.H.; Smith, P.L.; Gatzke, A.E.; McCreary, S.T.

    1980-01-01

    The physical, spatial and land-use impacts of decentralized solar technologies applied at the community level by the year 2000 are examined. The results of the study are intended to provide a basis for evaluating the way in which a shift toward reliance on decentralized energy technologies may eventually alter community form. Six land-use types representative of those found in most US cities are analyzed according to solar penetration levels identified in the maximum solar scenario for the year 2000. The scenario is translated into shares of end use demand in the residential, commercial and industrial sectors. These proportions become the scenario goals to be met by the use of decentralized solar energy systems. The percentage of total energy demand is assumed to be 36.5 percent, 18.8 percent and 22.6 percent in the residential, commercial and industrial sectors respectively. The community level scenario stipulated that a certain percentage of the total demand be met by on-site solar collection, i.e. photovoltaic and thermal collectors, and by passive design. This on-site solar goal is 31.9 percent (residential), 16.8 percent (commercial) and 13.1 percent (industrial).

  7. The impact of fiscal decentralization on infant mortality rates: evidence from OECD countries.

    Science.gov (United States)

    Jiménez-Rubio, Dolores

    2011-11-01

    This study re-examines the hypothesis that shifts towards more decentralization would be accompanied by improvements in population health on a panel of 20 OECD countries over a thirty year period (1970-2001). Decentralization is proxied using a conventional indicator of revenue decentralization and a new measure of fiscal decentralization that reflects better than previous measures the existence of autonomy in the decision-making authority of lower tiers of government, a crucial issue in the decentralization process. The results show a considerable and positive effect of fiscal decentralization on infant mortality only if a substantial degree of autonomy in the sources of revenue is devolved to local governments. The proportion of health care expenditure on GDP and, in particular, education, were found to have a larger contribution to the reduction of infant mortality in the sample of OECD countries analysed over the period of study.

  8. ON DECENTRALIZED STABILIZATION OF LINEAR LARGE SCALE SYSTEMS WITH SYMMETRIC CIRCULANT STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    金朝永; 张湘伟

    2004-01-01

    The decentralized stabilization of continuous and discrete linear large scale systems with symmetric circulant structure was studied. A few sufficient conditions on decentralized stabilization of such systems were proposed. For the continuous systems, by introducing a concept called the magnitude of interconnected structure, a very important property that the decentralized stabilization of such systems is fully determined by the structure of each isolated subsystem that is obtained when the magnitude of interconnected structure of the overall system is given. So the decentralized stabilization of such systems can be got by only appropriately designing or modifying the structure of each isolated subsystem,no matter how complicated the interconnected structure of the overall system is. A algorithm for obtaining decentralized state feedback to stabilize the overall system is given. The discrete systems were also discussed. The results show that there is a great dfference on decentralized stabilization between continuous case and discrete case.

  9. First measurements of ambient aerosol over an ecologically sensitive zone in Central India: Relationships between PM2.5 mass, its optical properties, and meteorology.

    Science.gov (United States)

    Sunder Raman, Ramya; Kumar, Samresh

    2016-04-15

    PM2.5 mass and its optical properties were measured over an ecologically sensitive zone in Central India between January and December, 2012. Meteorological parameters including temperature, relative humidity, wind speed, wind direction, and barometric pressure were also monitored. During the study period, the PM2.5 (fine PM) concentration ranged between 3.2μgm(-3) and 193.9μgm(-3) with a median concentration of 31.4μgm(-3). The attenuation coefficients, βATN at 370nm, 550nm, and 880nm had median values of 104.5Mm(-1), 79.2Mm(-1), and 59.8Mm(-1), respectively. Further, the dry scattering coefficient, βSCAT at 550nm had a median value of 17.1Mm(-1) while the absorption coefficient βABS at 550nm had a median value of 61.2Mm(-1). The relationship between fine PM mass and attenuation coefficients showed pronounced seasonality. Scattering, absorption, and attenuation coefficient at different wavelengths were all well correlated with fine PM mass only during the post-monsoon season (October, November, and December). The highest correlation (r(2)=0.81) was between fine PM mass and βSCAT at 550nm during post-monsoon season. During this season, the mass scattering efficiency (σSCAT) was 1.44m(2)g(-1). Thus, monitoring optical properties all year round, as a surrogate for fine PM mass was found unsuitable for the study location. In order to assess the relationships between fine PM mass and its optical properties and meteorological parameters, multiple linear regression (MLR) models were fitted for each season, with fine PM mass as the dependent variable. Such a model fitted for the post-monsoon season explained over 88% of the variability in fine PM mass. However, the MLR models were able to explain only 31 and 32% of the variability in fine PM during pre-monsoon (March, April, and May) and monsoon (June, July, August, and September) seasons, respectively. During the winter (January and February) season, the MLR model explained 54% of the PM2.5 variability.

  10. Environmental Decentralization: Seeking the Proper Balance between National and State Authority

    OpenAIRE

    Blackman, Allen; Morgenstern, Richard; Laskowski, Stanley

    2005-01-01

    This paper examines the United States’ experience with environmental decentralization, focusing on the relationship between the U.S. Environmental Protection Agency (EPA) and the states. It outlines the factors that are considered in determining the appropriate degree of decentralization, the advantages and disadvantages of decentralization, how the EPA-state relationship has evolved over the years, and the structural mechanisms used to ensure that there is a high degree of performance by EPA...

  11. Fiscal Decentralization and Regional Disparity: A Panel Data Approach for OECD Countries

    OpenAIRE

    Leßmann, Christian

    2006-01-01

    The advantages and disadvantages of public sector decentralization are widely discussedin economics and political science. While some authors argue that decentralization leads to an optimal provision of public services and a promotion of economic growth, others emphasize the dangers of competition associated with decentralization between subnational governments especially for redistributive reasons. These authors argue that poorer regions could not compete for mobile factors with the richer o...

  12. The decentralization reform on educational administration in contemporary China : Focusing on the compulsory education

    OpenAIRE

    孟, 洪珠

    2002-01-01

    This paper tries to uncover the reality of the decentralization reform on educational administration in contemporary China through institutional approach and experimental study. This papaer is different from the conventional research in that, most of the conventional research took an institutional approach, the analytic focus was placed on the presentation of the advantages and disadvantages in decentralization reform. In order to uncover the reality of decentralization reform, this paper ana...

  13. On the supply of China's healthcare resources in a decentralized healthcare system

    OpenAIRE

    Zheng, Xinye; Wang, Jing; Li, Xilu; Yu, Yihua

    2013-01-01

    The structure of China’s current governance bears prominent features of fiscal decentralization. The supply of healthcare resources in China has clearly witnessed slower growth in the last two decades during which the fiscal decentralization process has taken place. Using China’s provincial panel data, we examine the determinants of healthcare resource supply while paying particular attention to the role of fiscal decentralization. We find that the supply of healthcare resources is inversely ...

  14. (De)centralization of public procurement at the local level in the EU

    OpenAIRE

    Boštjan BREZOVNIK; Oplotnik, Žan Jan; Borut VOJINOVIĆ

    2017-01-01

    The so-called decentralization of public procurement in EU Member States is accepted as the most suitable design of the public procurement system, often justifi ed by greater economic effi ciency and by the possibility of boosting the development of small and medium-sized enterprises, which act on the public procurement market as providers of goods, services and works. Despite the existence of highly decentralized public procurement systems which refl ect the decentralization of administrativ...

  15. From State Control to Governance: Decentralization and Higher Education in Guangdong, China

    Science.gov (United States)

    Mok, Joshua Ka-Ho

    2001-03-01

    In China there has been a strong trend to diversification and decentralization of education in the post-Mao period. This paper examines how the policy of decentralization has affected the governance of universities in Guangdong. More specifically, the paper focuses on reform of the financing and management structure, the merging of universities, and joint development programmes to enhance competitiveness. Despite these changes, the state's role as a regulator and overall service coordinator has been strengthened rather than weakened under the policy of decentralization. This paper not only examines the recent developments in Guangdong's higher education but also analyses such developments in light of the global trend towards decentralization in educational governance.

  16. Posterior capsular opacification and intraocular lens decentration. Part I: Comparison of various posterior chamber lens designs implanted in the rabbit model.

    Science.gov (United States)

    Hansen, S O; Solomon, K D; McKnight, G T; Wilbrandt, T H; Gwin, T D; O'Morchoe, D J; Tetz, M R; Apple, D J

    1988-11-01

    Experimental phacoemulsification procedures were performed in 54 Rex rabbits. In 96 eyes, posterior chamber intraocular lenses (IOLs) were implanted in the capsular sac, and 12 eyes served as controls with no lens implantation. The IOLs were divided into eight groups consisting of both one-piece and three-piece styles with various optic designs. Each lens was evaluated for the relative effect on posterior capsular opacification (PCO) and optic decentration, two of the most common complications of modern cataract surgery and IOL implantation. Optics with a convex-anterior, plano-posterior design (the type of IOL optic most frequently implanted today) had the highest incidence of PCO. With capsular fixated IOLs, the features that have a statistically significant impact on reducing PCO include (1) one-piece, all-polymethylmethacrylate (PMMA) IOL styles, (2) a biconvex or posterior convex optic design, and (3) angulated loops. Lens decentration was not affected by the optic design, but statistical analysis showed that one-piece, all-PMMA IOL construction provided the most consistent centration.

  17. THE DECENTRALIZATION PROCESS IN ROMANIA HAS BEEN AFFECTED BY THE FINANCIAL CRISIS OR NOT; ARGUMENTS IN FAVOR OR AGAINST DECENTRALIZATION IN THE MANAGEMENT OF THE FINANCIAL CRISIS

    Directory of Open Access Journals (Sweden)

    OLIVIA MANOLE

    2012-12-01

    Full Text Available Typically, the decentralization process is extremely complicated and involves many challenges, if we were to take into account local conflicts, the interests of the central government and the complexity of simultaneous decentralization in administrative, political and economic plan. The financial crisis has added another dimension to the complexity of this phenomenon, misbalancing the economy and creating a fiscal pressure both at central and local level. In this context it rises the problem whether the management of the financial crisis can be better realised within a decentralized system or whether it may lay pressure on the return to the centralized government form.

  18. Decentralized Formation Flying Control in a Multiple-Team Hierarchy

    Science.gov (United States)

    Mueller, Joseph .; Thomas, Stephanie J.

    2005-01-01

    This paper presents the prototype of a system that addresses these objectives-a decentralized guidance and control system that is distributed across spacecraft using a multiple-team framework. The objective is to divide large clusters into teams of manageable size, so that the communication and computational demands driven by N decentralized units are related to the number of satellites in a team rather than the entire cluster. The system is designed to provide a high-level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The distributed guidance and control system will be implemented in an object-oriented style using MANTA (Messaging Architecture for Networking and Threaded Applications). In this architecture, tasks may be remotely added, removed or replaced post-launch to increase mission flexibility and robustness. This built-in adaptability will allow software modifications to be made on-orbit in a robust manner. The prototype system, which is implemented in MATLAB, emulates the object-oriented and message-passing features of the MANTA software. In this paper, the multiple-team organization of the cluster is described, and the modular software architecture is presented. The relative dynamics in eccentric reference orbits is reviewed, and families of periodic, relative trajectories are identified, expressed as sets of static geometric parameters. The guidance law design is presented, and an example reconfiguration scenario is used to illustrate the distributed process of assigning geometric goals to the cluster. Next, a decentralized maneuver planning approach is presented that utilizes linear-programming methods to enact reconfiguration and coarse formation keeping maneuvers. Finally, a method for performing online collision avoidance is discussed, and an example is provided to gauge its performance.

  19. Centralization and decentralization in energy systems and associated risks

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, W.; Schinner, F.; Kromp, W. [Vienna Univ., Institute of Risk Research, IRR (Austria)

    1998-07-01

    Full text of publication follows: the concept of centralization/decentralization is - considering its widespread use - surprisingly ill-defined. Within the SERF-program (Socio Economic Research on Fusion) an attempt is made to clarify the complex issue of centralization/decentralization and to analyze its expected interaction with electricity production system in the case of nuclear fusion. Fusion research at the time is a multinational, highly centralized undertaking. As a result of this, and due to the expected large energy production units, it is generally expected that fusion will be embedded in a highly centralized, international energy supply system. The degree of centralization of an energy supply system, however, is believed to have for reaching consequences on the stability of the system, and beyond that, on decision making processes in energy policy, as well as democratic structures on the national or even international level. Internationalization might require control instruments that do not exist so far. Amongst other reservations, it is the possibly unwanted consequences of such a highly centralized, international energy supply system that limit acceptance of the fusion technology in the public. Therefore, centralization and decentralization trends of energy supply systems over the years are being looked at, to study their influence on the political and social systems (and vice-versa). In a first step, an attempt is made to classify centralization. Careful analyses and evaluation of available literature revealed a broad spectrum of different forms and degrees of centralization. Various parameters describing energy production and distribution are used. A differentiation of centralization on a technical and on an organizational level seems necessary, although they are not fully independent of each other. Beyond this, the choice of parameters must depend on the questions to be addressed. A new approach defining different levels and degrees of

  20. Effects of health decentralization, financing and governance in Mexico

    Directory of Open Access Journals (Sweden)

    Armando Arredondo

    2006-02-01

    Full Text Available OBJECTIVE: To identify the effects of decentralization on health financing and governance policies in Mexico from the perspective of users and providers. METHODS: A cross-sectional study was carried out in four states that were selected according to geopolitical and administrative criteria. Four indicators were assessed: changes and effects on governance, financing sources and funds, the final destination of resources, and fund allocation mechanisms. Data collection was performed using in-depth interviews with health system key personnel and community leaders, consensus techniques and document analyses. The interviews were transcribed and analyzed by thematic segmentation. RESULTS: The results show different effectiveness levels for the four states regarding changes in financing policies and community participation. Effects on health financing after decentralization were identified in each state, including: greater participation of municipal and state governments in health expenditure, increased financial participation of households, greater community participation in low-income states, duality and confusion in the new mechanisms for coordination among the three government levels, absence of an accountability system, lack of human resources and technical skills to implement, monitor and evaluate changes in financing. CONCLUSIONS: In general, positive and negative effects of decentralization on health financing and governance were identified. The effects mentioned by health service providers and users were related to a diversification of financing sources, a greater margin for decisions around the use and final destination of financial resources and normative development for the use of resources. At the community level, direct financial contributions were mentioned, as well as in-kind contributions, particularly in the form of community work.

  1. Actively heated high-resolution fiber-optic-distributed temperature sensing to quantify streambed flow dynamics in zones of strong groundwater upwelling

    Science.gov (United States)

    Briggs, Martin A.; Buckley, Sean F.; Bagtzoglou, Amvrossios C.; Werkema, Dale D.; Lane, John W.

    2016-07-01

    Zones of strong groundwater upwelling to streams enhance thermal stability and moderate thermal extremes, which is particularly important to aquatic ecosystems in a warming climate. Passive thermal tracer methods used to quantify vertical upwelling rates rely on downward conduction of surface temperature signals. However, moderate to high groundwater flux rates (>-1.5 m d-1) restrict downward propagation of diurnal temperature signals, and therefore the applicability of several passive thermal methods. Active streambed heating from within high-resolution fiber-optic temperature sensors (A-HRTS) has the potential to define multidimensional fluid-flux patterns below the extinction depth of surface thermal signals, allowing better quantification and separation of local and regional groundwater discharge. To demonstrate this concept, nine A-HRTS were emplaced vertically into the streambed in a grid with ˜0.40 m lateral spacing at a stream with strong upward vertical flux in Mashpee, Massachusetts, USA. Long-term (8-9 h) heating events were performed to confirm the dominance of vertical flow to the 0.6 m depth, well below the extinction of ambient diurnal signals. To quantify vertical flux, short-term heating events (28 min) were performed at each A-HRTS, and heat-pulse decay over vertical profiles was numerically modeled in radial two dimension (2-D) using SUTRA. Modeled flux values are similar to those obtained with seepage meters, Darcy methods, and analytical modeling of shallow diurnal signals. We also observed repeatable differential heating patterns along the length of vertically oriented sensors that may indicate sediment layering and hyporheic exchange superimposed on regional groundwater discharge.

  2. Investigation of magnetic property of GdFeO{sub 3} single crystal grown in air by optical floating zone technique

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh Babu, P. [Centre for Crystal Growth, School Advance Sciences, VIT University, Vellore, Tamil Nadu (India); Bhaumik, Indranil [Crystal Growth Laboratory, Laser Materials Development and Devices Division, Raja Ramanna Centre for Advanced Technology, Indore (India); Ganesamoorthy, S. [X-ray Scattering and Crystal Growth Section, CMPD, Material Science Group, IGCAR, Kalpakkam, Tamil Nadu (India); Kalainathan, S., E-mail: kalainathan@yahoo.com [Centre for Crystal Growth, School Advance Sciences, VIT University, Vellore, Tamil Nadu (India); Bhatt, R.; Karnal, A.K.; Gupta, P.K. [Crystal Growth Laboratory, Laser Materials Development and Devices Division, Raja Ramanna Centre for Advanced Technology, Indore (India)

    2015-05-15

    Highlights: • GdFeO{sub 3} single crystals have been grown by OFZ technique in air. • Sample exhibits one order lower coercive field than crystal grown in oxygen. • Bloch 3/2-law holds good for GdFeO{sub 3} (B-parameter as 2.69 × 10{sup −5} K{sup −3/2}). • The coercivity exhibited sharp dip at 200 and 550 K. • At 550 K pinning of the direction of weak ferromagnetism by AFM ordering vanishes. - Abstract: Single phase Gadolinium orthoferrite (GdFeO{sub 3}) with orthorhombic perovskite structure was synthesized without any garnet impurities by solid state reaction and subsequently GdFeO{sub 3} single crystals were grown by the optical floating zone technique. The temperature dependent magnetization measurement revealed the magnetic phase transition from anti-ferromagnetic ordering to paramagnetic ordering at 670 K. The overlapping of the magnetization measured under zero-field and field cooling condition in the range of 300–20 K signifies that there is no magnetic transition in this temperature range. The hysteresis loop measurements revealed that in comparison to the values reported for the crystal grown in oxygen, the air grown sample exhibits one order lower coercive field (∼75 Oe). The Bloch 3/2-law was found to hold good for GdFeO{sub 3} with the value of B-parameter as 2.69 × 10{sup −5} K{sup −3/2}. The coercivity exhibited sharp dip at 200 and 550 K. At and above 550 K the ability of the antiferromagnetic ordering to pin the direction of magnetization related to the weak ferromagnetism present in the material vanishes leading to the lowering in the coercivity.

  3. Genetic Algorithm based Decentralized PI Type Controller: Load Frequency Control

    Science.gov (United States)

    Dwivedi, Atul; Ray, Goshaidas; Sharma, Arun Kumar

    2016-12-01

    This work presents a design of decentralized PI type Linear Quadratic (LQ) controller based on genetic algorithm (GA). The proposed design technique allows considerable flexibility in defining the control objectives and it does not consider any knowledge of the system matrices and moreover it avoids the solution of algebraic Riccati equation. To illustrate the results of this work, a load-frequency control problem is considered. Simulation results reveal that the proposed scheme based on GA is an alternative and attractive approach to solve load-frequency control problem from both performance and design point of views.

  4. Semi-decentralized Strategies in Structural Vibration Control

    Directory of Open Access Journals (Sweden)

    F. Palacios-Quiñonero

    2011-04-01

    Full Text Available In this work, the main ideas involved in the design of overlapping and multi-overlapping controllers via the Inclusion Principle are discussed and illustrated in the context of the Structural Vibration Control of tall buildings under seismic excitation. A detailed theoretical background on the Inclusion Principle and the design of overlapping controllers is provided. Overlapping and multi-overlapping LQR controllers are designed for a simplified five-story building model. Numerical simulations are conducted to asses the performance of the proposed semi-decentralized controllers with positive results.

  5. Optimal decentralized feedback control for a truss structure

    Science.gov (United States)

    Cagle, A.; Ozguner, U.

    1989-01-01

    One approach to the decentralized control of large flexible space structures involves the design of controllers for the substructures of large systems and their subsequent application to the entire coupled system. This approach is presently developed for the case of active vibration damping on an experimental large struss structure. The isolated boundary loading method is used to define component models by FEM; component controllers are designed using an interlocking control concept which minimizes the motion of the boundary nodes, thereby reducing the exchange of mechanical disturbances among components.

  6. DECENTRALIZED THERMOPHILIC BIOHYDROGEN: A MORE EFFICIENT AND COST EFFECTIVE PROCESS

    Directory of Open Access Journals (Sweden)

    Rajesh K. Sani

    2011-11-01

    Full Text Available Nonfood lignocellulosic biomass is an ideal substrate for biohydrogen production. By avoiding pretreatment steps (acid, alkali, or enzymatic, there is potential to make the process economical. Utilization of regional untreated lignocellulosic biomass by cellulolytic and fermentative thermophiles in a consolidated mode using a single reactor is one of the ways to achieve economical and sustainable biohydrogen production. Employing these potential microorganisms along with decentralized biohydrogen energy production will lead us towards regional and national independence having a positive influence on the bioenergy sector.

  7. Decentralized impulsive control for a class of uncertain interconnected systems

    Institute of Scientific and Technical Information of China (English)

    成新明; 关治洪; 刘新芝

    2004-01-01

    A great deal of stabilization criteria has been obtained from study of stabilizing interconnected systems. The results obtained are usually based on continuous systems by state feedback. In this paper, decentralized impulsive control is presented to stabilize a class of uncertain interconnected systems based on Lyapunov theory. The system under consideration involves parameter uncertainties and unknown nonlinear interactions among subsystems. Some new criteria of stabilization under impulsive control are established. Two numerical examples are offered to prove the effectiveness and practicality of the proposed method.

  8. Decentralized adaptive generalized predictive control for structural vibration

    Institute of Scientific and Technical Information of China (English)

    LU Minyue; GU Zhongquan

    2005-01-01

    A decentralized generalized predictive control (GPC) algorithm is developed for strongly coupled multi-input multi-output systems with parallel computation. The algorithm is applied to adaptive control of structural vibration. The key steps in this algorithm are to group the actuators and the sensors and then to pair these groups into subsystems. It is important that the on-line identification and the control law design can be a parallel process for all these subsystems. It avoids the high computation cost in ordinary predictive control,and is of great advantage especially for large-scale systems.

  9. Decentralized control and filtering in interconnected dynamical systems

    CERN Document Server

    Mahmoud, Magdi S

    2011-01-01

    Based on the many approaches available for dealing with large-scale systems (LSS), Decentralized Control and Filtering in Interconnected Dynamical Systems supplies a rigorous framework for studying the analysis, stability, and control problems of LSS. Providing an overall assessment of LSS theories, it addresses model order reduction, parametric uncertainties, time delays, and control estimator gain perturbations. Taking readers on a guided tour through LSS, the book examines recent trends and approaches and reviews past methods and results from a contemporary perspective. It traces the progre

  10. Robust decentralized adaptive stabilization for a class of interconnected systems

    Institute of Scientific and Technical Information of China (English)

    Zhaojing WU; Xuejun XIE; Siying ZHANG

    2004-01-01

    The robust decentralized adaptive output-feedback stabilization for a class of interconnected systems with static and dynamic interconnections by using the MT-filters and backstepping design method is studied. By introducing a new filtered tramformation, the adaptive laws were derived for measurement. Under the assumption of the nonlinear growth conditions imposed on the nonlinear interconnections and by constructing the error system and using a new proof method, the global stability of the closed-loop system was effectively analyzed, and the exponential convergence of all the signals except for parameter estimates were guaranteed.

  11. A semi-decentralized control strategy for urban traffic

    OpenAIRE

    Farhi, Nadir; Nguyen Van Phu, Cyril; AMIR, Mouna; Haj Salem, Habib; LEBACQUE, Jean Patrick

    2015-01-01

    EWGT - Euro Working Group on Transportation, Delft, PAYS-BAS, 14-/07/2015 - 16/07/2015; We present in this article a semi-decentralized approach for urban traffic control, based on the TUC (Traffic responsive Urban Control) strategy. We assume that the control is centralized as in the TUC strategy, but we introduce a contention time window inside the cycle time, where antagonistic stages alternate a priority rule. The priority rule is set by applying green colours for given stages and yellow ...

  12. The Effect of Fiscal Decentralization on Under-five Mortality in Iran: A Panel Data Analysis.

    Science.gov (United States)

    Samadi, Ali Hussein; Keshtkaran, Ali; Kavosi, Zahra; Vahedi, Sajad

    2013-11-01

    Fiscal Decentralization (FD) in many cases is encouraged as a strong means of improving the efficiency and equity in the provision of public goods, such as healthcare services. This issue has urged the researchers to experimentally examine the relationship between fiscal decentralization indicators and health outcomes. In this study we examine the effect of Fiscal Decentralization in Medical Universities (FDMU) and Fiscal Decentralization in Provincial Revenues (FDPR) on Under-Five Mortality Rate (U5M) in provinces of Iran over the period between 2007 and 2010. We employed panel data methods in this article. The results of the Pesaran CD test demonstrated that most of the variables used in the analysis were cross-sectionally dependent. The Hausman test results suggested that fixed-effects were more appropriate to estimate our model. We estimated the fixed-effect model by using Driscoll-Kraay standard errors as a remedy for cross-sectional dependency. According to the findings of this research, fiscal decentralization in the health sector had a negative impact on U5M. On the other hand, fiscal decentralization in provincial revenues had a positive impact on U5M. In addition, U5M had a negative association with the density of physicians, hospital beds, and provincial GDP per capita, but a positive relationship with Gini coefficient and unemployment. The findings of our study indicated that fiscal decentralization should be emphasized in the health sector. The results suggest the need for caution in the implementation of fiscal decentralization in provincial revenues.

  13. High Expectations, Varying Outcomes: Decentralization and Participation in Brazil, Japan, Russia and Sweden

    NARCIS (Netherlands)

    Andrews, C.W.; Vries, M.S. de

    2007-01-01

    In the past 20 years, decentralization has been proposed as a strategy for enhancing public participation. Aid-providing organizations, such as the World Bank, stimulated decentralization processes in several countries in the hope that this would promote civic empowerment, diminish corruption, enhan

  14. Decentralized substations for low-temperature district heating with no Legionella risk, and low return temperatures

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

    2016-01-01

    with domestic hot water (DHW) circulation. In this study, a system with decentralized substations was analysed as a solution to this problem. Furthermore, a modification for the decentralized substation system were proposed in order to reduce the average return temperature. Models of conventional system...

  15. Nutrient removal by NF and RO membranes in a decentralized sanitation system

    NARCIS (Netherlands)

    Voorthuizen, van Ellen M.; Zwijnenburg, Arie; Wessling, Matthias

    2005-01-01

    Decentralized treatment of domestic wastewater offers the possibility of water and nutrient reuse. In a decentralized sanitation system the household wastewater streams are separated in a large diluted stream (gray water) and a small and concentrated stream (black water) containing important nutrien

  16. The impact of corporate and national cultures on decentralization in multinational corporations

    NARCIS (Netherlands)

    Williams, C.; van Triest, S.

    2009-01-01

    We develop and test a model of multinational corporation (MNC) decentralization in which the allocation of decision rights to subsidiaries is explained by aspects of both internal corporate culture as well as external national cultures. We extend the literature on MNC decentralization by testing the

  17. Street-Level Governments: Assessing Decentralization and Urban Services (Executive Summary).

    Science.gov (United States)

    Yin, Robert K.; Yates, Douglas

    The purpose of the study reported here was to assess the various decentralization efforts as they occurred in different services and in different cities. The study reviewed decentralization's record in terms of five outcomes: (1) Increases in the flow of information between servers and served; (2) Improvements in service officials attitudes; (3)…

  18. The impact of corporate and national cultures on decentralization in multinational corporations

    NARCIS (Netherlands)

    C. Williams; S. van Triest

    2009-01-01

    We develop and test a model of multinational corporation (MNC) decentralization in which the allocation of decision rights to subsidiaries is explained by aspects of both internal corporate culture as well as external national cultures. We extend the literature on MNC decentralization by testing the

  19. Reliable Control of Decentralized Systems: An ARE-Based H-Infinity Approach

    Science.gov (United States)

    1990-07-01

    IEEE Transactions on Automatic Control , 34(3):293...systems. Auto- matica, 12:479-495, 1976. [7] E. J. Davison. The robust decentralized control of a general servomechanism problem. IEEE Transactions on Automatic Control , AC...connections. IEEE Transactions on Automatic Control , AC-23(2):325-327, April 1979. [9] E. J. Davison. The decentralized control of large

  20. [Analysis of the healthcare service decentralization process in Côte d'Ivoire].

    Science.gov (United States)

    Soura, B D; Coulibaly, S S

    2014-01-01

    The decentralization of healthcare services is becoming increasingly important in strategies of public sector management. This concept is analyzed from various points of view, including legal, economic, political, and sociological. Several typologies have been proposed in the literature to analyze this decentralization process, which can take different forms ranging from simple deconcentration to more elaborate devolution. In some instances, decentralization can be analyzed by the degree of autonomy given to local authorities. This article applies these typologies to analyze the healthcare system decentralization process in Cote d'Ivoire. Special attention is paid to the new forms of community healthcare organizations. These decentralized structures enjoy a kind of autonomy, with characteristics closer to those of devolution. The model might serve as an example for population involvement in defining and managing healthcare problems in Cote d'Ivoire. We end with proposals for the improvement of the process.

  1. ABS-NET: Fully Decentralized Runtime Adaptation for Distributed Objects

    Directory of Open Access Journals (Sweden)

    Karl Palmskog

    2013-10-01

    Full Text Available We present a formalized, fully decentralized runtime semantics for a core subset of ABS, a language and framework for modelling distributed object-oriented systems. The semantics incorporates an abstract graph representation of a network infrastructure, with network endpoints represented as graph nodes, and links as arcs with buffers, corresponding to OSI layer 2 interconnects. The key problem we wish to address is how to allocate computational tasks to nodes so that certain performance objectives are met. To this end, we use the semantics as a foundation for performing network-adaptive task execution via object migration between nodes. Adaptability is analyzed in terms of three Quality of Service objectives: node load, arc load and message latency. We have implemented the key parts of our semantics in a simulator and evaluated how well objectives are achieved for some application-relevant choices of network topology, migration procedure and ABS program. The evaluation suggests that it is feasible in a decentralized setting to continually meet both the objective of a node-balanced task allocation and make headway towards minimizing communication, and thus arc load and message latency.

  2. A Decentralized Heuristic Approach towards Resource Allocation in Femtocell Networks

    Directory of Open Access Journals (Sweden)

    Kyung-Geun Lee

    2013-06-01

    Full Text Available Femtocells represent a novel configuration for existing cellular communication, contributing towards the improvement of coverage and throughput. The dense deployment of these femtocells causes significant femto-macro and femto-femto interference, consequently deteriorating the throughput of femtocells. In this study, we compare two heuristic approaches, i.e., particle swarm optimization (PSO and genetic algorithm (GA, for joint power assignment and resource allocation, within the context of the femtocell environment. The supposition made in this joint optimization is that the discrete power levels are available for the assignment. Furthermore, we have employed two variants of each PSO and GA: inertia weight and constriction factor model for PSO, and twopoint and uniform crossover for GA. The two proposed algorithms are in a decentralized manner, with no involvement of any centralized entity. The comparison is carried out between the two proposed algorithms for the aforementioned joint optimization problem. The contrast includes the performance metrics: including average objective function, min–max throughput of the femtocells, average throughput of the femto users, outage rate and time complexity. The results demonstrate that the decentralized PSO constriction factor outperforms the others in terms of the aforementioned performance metrics.

  3. Large-scale experimental design for decentralized SLAM

    Science.gov (United States)

    Cunningham, Alex; Dellaert, Frank

    2012-06-01

    This paper presents an analysis of large scale decentralized SLAM under a variety of experimental conditions to illustrate design trade-offs relevant to multi-robot mapping in challenging environments. As a part of work through the MAST CTA, the focus of these robot teams is on the use of small-scale robots with limited sensing, communication and computational resources. To evaluate mapping algorithms with large numbers (50+) of robots, we developed a simulation incorporating sensing of unlabeled landmarks, line-of-sight blocking obstacles, and communication modeling. Scenarios are randomly generated with variable models for sensing, communication, and robot behavior. The underlying Decentralized Data Fusion (DDF) algorithm in these experiments enables robots to construct a map of their surroundings by fusing local sensor measurements with condensed map information from neighboring robots. Each robot maintains a cache of previously collected condensed maps from neighboring robots, and actively distributes these maps throughout the network to ensure resilience to communication and node failures. We bound the size of the robot neighborhoods to control the growth of the size of neighborhood maps. We present the results of experiments conducted in these simulated scenarios under varying measurement models and conditions while measuring mapping performance. We discuss the trade-offs between mapping performance and scenario design, including robot teams separating and joining, multi-robot data association, exploration bounding, and neighborhood sizes.

  4. The material politics of waste disposal - decentralization and integrated systems

    Directory of Open Access Journals (Sweden)

    Penelope Harvey

    2012-12-01

    Full Text Available This article and the previous «Convergence and divergence between the local and regional state around solid waste management. An unresolved problem in the Sacred Valley» from Teresa Tupayachi are published as complementary accounts on the management of solid waste in the Vilcanota Valley in Cusco. Penelope Harvey and Teresa Tupayachi worked together on this theme. The present article explores how discontinuities across diverse instances of the state are experienced and understood. Drawing from an ethnographic study of the Vilcanota Valley in Cusco, the article looks at the material politics of waste disposal in neoliberal times. Faced with the problem of how to dispose of solid waste, people from Cusco experience a lack of institutional responsibility and call for a stronger state presence. The article describes the efforts by technical experts to design integrated waste management systems that maximise the potential for re-cycling, minimise toxic contamination, and turn ‘rubbish’ into the altogether more economically lively category of ‘solid waste’. However while the financialization of waste might appear to offer an indisputable public good, efforts to instigate a viable waste disposal business in a decentralizing political space elicit deep social tensions and contradictions. The social discontinuities that decentralization supports disrupt ambitions for integrated solutions as local actors resist top-down models and look not just for alternative solutions, but alternative ways of framing the problem of urban waste, and by extension their relationship to the state.

  5. From centralization to decentralization in Chinese higher education

    Directory of Open Access Journals (Sweden)

    Xiaohong Qian

    2004-12-01

    Full Text Available Since the late 1970’s, the Chinese government has been gradually changing its traditional policy for providing higher education and has begun to emphasize the comprehensiveness of the universities. Interdisciplinary cooperation and the synergization of resources are being promoted, and institutional autonomy is gradually increasing. Schools and faculties have been restored in universities, and new research institutions, research schools, research centers and the like have been established. From a unitary three-level model— university/department/ teaching and research group—before the reform, the organizational structures of the universities have developed a new organizational structure that is more flexible and more open. This more adaptable structure is intended to meet the developmental demands of modern universities with close links being created between their work and regional economic and social development. China has moved from a very centralized educational system in which the main decisions were taken by the central government to a decentralized educational system. This reform is also taking place within the institutions of higher education, and their internal organizational structure has also become more decentralized.

  6. Energy conservation and energy decentralization: issues and prospects

    Energy Technology Data Exchange (ETDEWEB)

    Levine, M.D.; Craig, P.P.

    1980-01-01

    Views are presented of the seemingly paradoxical nature and irrationality of the energy system and the decisions that determine its evolution. An economic approach to energy decisions, while widely espoused and generally believed to be the underpinning of our system, appears not to be functioning in very-important areas. The result is enormous waste of economic and intangible resources to produce energy that could be effectively replaced by energy conservation at low costs. This inefficiency in the economic system is, in the author's judgment, far greater than is recognized either by the public or by experts. They feel it has led to an over-investment in centralized energy systems and has discouraged the use of decentralized systems that could contribute significantly in the near term to a lessening of our energy problems. There are some signs that the situation is changing, albeit rather slowly. High prices and the widespread recognition of the seriousness of our energy problems have contributed to an increasing involvement of individuals in energy decisions profoundly affecting their future. To achieve an evolution of the energy system in which decentralized technologies (and, in the near term, particularly technologies that improve the efficiency of energy use) play an important role, the government must act forcefully. This action needs to recognize and be responsive to the powerful discriminatory effect of the economic system, as it is presently constituted, against investments in energy conservation.

  7. The indicators of energy security of decentralized heating

    Directory of Open Access Journals (Sweden)

    Elena Vitalyevna Bykova

    2013-06-01

    Full Text Available In the paper, the new additional indicators of energy security with the purpose to include decentralized heating sector is developed in the work. The structure of the housing stock of the country is analyzed, which includes different types of central heating boilers and CHP, individual gas or electric heating and stove heating.The analysis of the existing thermal supply (per unit area and per capita living for each sector is carried out. It is found that heat consumed in the residential sector with central heating from CHP and boilers is significantly higher of heat consumed in other sectors. The missing amount of heat energy, which can be produced in two ways, is calculated. Part of the deficit heat can be produced at existing sources that are not loaded enough to the nominal parameters at the moment. The second part can be obtained from small new sources (for inhabited localities that do not have a centralized heat supply infrastructure. New indicators complement the system of indicators to be used to analyze and monitoring the level of Moldova's energy security. They allowed including decentralized heat supply sector, which is not reflected in the official statistics. At the same, the calculation methodology has been improved and the overall integral indicator of the energy security level, which was even more crisis than previously thought.

  8. Decentralized Optimal Dispatch of Photovoltaic Inverters in Residential Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Anese, Emiliano; Dhople, Sairaj V.; Johnson, Brian B.; Giannakis, Georgios B.

    2015-10-05

    Summary form only given. Decentralized methods for computing optimal real and reactive power setpoints for residential photovoltaic (PV) inverters are developed in this paper. It is known that conventional PV inverter controllers, which are designed to extract maximum power at unity power factor, cannot address secondary performance objectives such as voltage regulation and network loss minimization. Optimal power flow techniques can be utilized to select which inverters will provide ancillary services, and to compute their optimal real and reactive power setpoints according to well-defined performance criteria and economic objectives. Leveraging advances in sparsity-promoting regularization techniques and semidefinite relaxation, this paper shows how such problems can be solved with reduced computational burden and optimality guarantees. To enable large-scale implementation, a novel algorithmic framework is introduced - based on the so-called alternating direction method of multipliers - by which optimal power flow-type problems in this setting can be systematically decomposed into sub-problems that can be solved in a decentralized fashion by the utility and customer-owned PV systems with limited exchanges of information. Since the computational burden is shared among multiple devices and the requirement of all-to-all communication can be circumvented, the proposed optimization approach scales favorably to large distribution networks.

  9. Convergent Double Auction Mechanism for a Prosumers’ Decentralized Smart Grid

    Directory of Open Access Journals (Sweden)

    Tadahiro Taniguchi

    2015-10-01

    Full Text Available In this paper, we propose a novel automated double auction mechanism called convergent linear function submission-based double-auction (CLFS-DA for a prosumers’ decentralized smart grid. The target decentralized smart grid is a regional electricity network that consists of many prosumers that have a battery and a renewable energy-based generator, such as photovoltaic cells. In the proposed double-auction mechanism, each intelligent software agent representing each prosumer submits linear demand and supply functions to an automated regional electricity market where they are registered. It is proven that the CLFS-DA mechanism is guaranteed to obtain one of the global optimal price profiles in addition to it achieving an exact balance between demand and supply, even through the learning period. The proof of convergence is provided on the basis of the theory of LFS-DA, which gives a clear bridge between a function submission-based double auction and a dual decomposition (DD-based real-time pricing procedure. The performance of the proposed mechanism is demonstrated numerically through a simulation experiment.

  10. Centralization and Decentralization of Public Policy in a Complex Framework

    Directory of Open Access Journals (Sweden)

    Maria ROSARIA ALFANO

    2009-05-01

    Full Text Available The public economic literature of the past century is characterized by a traditional paradigm that ascribes little attention to the spatial dimension. However, contemporary globalization requires that researchers and economists expand their perspectives to consider space conceptualization. What is required in the 21st century is a richer and more realistic framework that broadens existing concepts of socio-economic analysis while overcoming narrow national borders. Although national governments will remain prominent performers in the global market, regional and local governments cannot be ignored because citizens worldwide are exerting greater self-determination in influencing governmental decisions. This paper is focused on the opportunity to analyze the governance of decentralization by the new optimizing procedures provided by complex system theory. The first section of the paper explores the positive and normative issues related to centralization and decentralization in a globalized framework as well as the increased interdependence in power sharing among different jurisdictional level. In the second section, Kauffman’s (1993 contributions are examined as a means of determining if the fitness landscape allows combining the institutional evolution. Finally, this paper concludes highlighting that complex system theory is one of the possible tools useful to redesign the map of institutional sharing power in an era of globalization, considering that it allows catching Pareto improving in the level of welfare.

  11. Outdoor flocking of quadcopter drones with decentralized model predictive control.

    Science.gov (United States)

    Yuan, Quan; Zhan, Jingyuan; Li, Xiang

    2017-07-11

    In this paper, we present a multi-drone system featured with a decentralized model predictive control (DMPC) flocking algorithm. The drones gather localized information from neighbors and update their velocities using the DMPC flocking algorithm. In the multi-drone system, data packages are transmitted through XBee(®) wireless modules in broadcast mode, yielding such an anonymous and decentralized system where all the calculations and controls are completed on an onboard minicomputer of each drone. Each drone is a double-layered agent system with the coordination layer running multi-drone flocking algorithms and the flight control layer navigating the drone, and the final formation of the flock relies on both the communication range and the desired inter-drone distance. We give both numerical simulations and field tests with a flock of five drones, showing that the DMPC flocking algorithm performs well on the presented multi-drone system in both the convergence rate and the ability of tracking a desired path. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  12. Decentralized Hypothesis Testing in Energy Harvesting Wireless Sensor Networks

    Science.gov (United States)

    Tarighati, Alla; Gross, James; Jalden, Joakim

    2017-09-01

    We consider the problem of decentralized hypothesis testing in a network of energy harvesting sensors, where sensors make noisy observations of a phenomenon and send quantized information about the phenomenon towards a fusion center. The fusion center makes a decision about the present hypothesis using the aggregate received data during a time interval. We explicitly consider a scenario under which the messages are sent through parallel access channels towards the fusion center. To avoid limited lifetime issues, we assume each sensor is capable of harvesting all the energy it needs for the communication from the environment. Each sensor has an energy buffer (battery) to save its harvested energy for use in other time intervals. Our key contribution is to formulate the problem of decentralized detection in a sensor network with energy harvesting devices. Our analysis is based on a queuing-theoretic model for the battery and we propose a sensor decision design method by considering long term energy management at the sensors. We show how the performance of the system changes for different battery capacities. We then numerically show how our findings can be used in the design of sensor networks with energy harvesting sensors.

  13. Decentralized enforcement, sequential bargaining, and the clean development mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Hovi, Jon

    2001-07-01

    While there is a vast literature both on international bargaining and on how international agreements can be enforced, very little work has been done on how bargaining and enforcement interact. An important exception is Fearon (1998), who models international cooperation as a two-stage process in which the bargaining process is constrained by a need for decentralized enforcement (meaning that the agreement must be enforced by the parties themselves rather than a third party, such as a court). Using the Clean Development Mechanism as an example, the present paper proposes a different model of this kind of interaction. The model follows Fearon's in so far as we both use the infinitely repeated Prisoners' Dilemma to capture the enforcement phase of the game. However, while Fearon depicts the bargaining stage as a War of Attrition, the present model sees that stage as a sequential bargaining game of the Staahl-Rubinstein type. The implications of the present model are compared both to those of the Staahl-Rubinstein model and to those of the Fearon model. A surprising conclusion is that a need for decentralized enforcement tends to make the bargaining outcome more symmetrical than otherwise. Thus, the impact of bargaining power is actually smaller when the resulting agreement must be enforced by the parties themselves than it is if enforcement is taken care of by a third party. (author)

  14. Engineering Optics

    CERN Document Server

    Iizuka, Keigo

    2008-01-01

    Engineering Optics is a book for students who want to apply their knowledge of optics to engineering problems, as well as for engineering students who want to acquire the basic principles of optics. It covers such important topics as optical signal processing, holography, tomography, holographic radars, fiber optical communication, electro- and acousto-optic devices, and integrated optics (including optical bistability). As a basis for understanding these topics, the first few chapters give easy-to-follow explanations of diffraction theory, Fourier transforms, and geometrical optics. Practical examples, such as the video disk, the Fresnel zone plate, and many more, appear throughout the text, together with numerous solved exercises. There is an entirely new section in this updated edition on 3-D imaging.

  15. Optical Properties of Parallax Barrier and It's Influence on View Zone%狭缝光栅分光特性及其对视区的影响

    Institute of Scientific and Technical Information of China (English)

    王涛; 张涛; 张春光; 翟思洪; 杨新军

    2013-01-01

    应用光栅等分光元件对视差图进行空间分离是实现立体显示的重要方法之一,介绍了狭缝光栅作为分光元件实现立体显示的原理,建立了子像素发光经过多个周期狭缝光栅的数学模型,分析狭缝光栅参数及子像素发光宽度对视区及立体显示器亮度的影响.结果表明,在对狭缝光栅参数设计过程中需要综合考虑视区特性与显示器亮度,狭缝的透光比应控制在0.2~0.3,在样机生产过程中将透光比定为0.25,采用高亮背光模式以补偿立体显示器亮度,取得了较好效果.结果对狭缝光栅的参数设计具有指导意义.%Redistributing parallax images by light directing element such as grating is one of the most important methods to achieve 3D display. This paper gives an introduction of how parallax barrier works to realize 3D display. The mathematical model of beams out of multi-period of barrier has been built to explore the roles played by barrier and width of sub pixel. Software to simulate the optical field in front of the 3D display has been developed. Both property of view zone and brightness of the display should be considered in order to get better 3D result. This study shows that the slit ratio for parallax barrier should between 0. 2 and 0. 3. In the process of prototype making the scale was set to 0. 25. Particular bright backlight module was applied to compensating the lower brightness caused by lower scale and the display got a satisfactory result. The result has directive meaning for design of 3D display based on parallax barrier.

  16. Decentralized formation flying control in a multiple-team hierarchy.

    Science.gov (United States)

    Mueller, Joseph B; Thomas, Stephanie J

    2005-12-01

    In recent years, formation flying has been recognized as an enabling technology for a variety of mission concepts in both the scientific and defense arenas. Examples of developing missions at NASA include magnetospheric multiscale (MMS), solar imaging radio array (SIRA), and terrestrial planet finder (TPF). For each of these missions, a multiple satellite approach is required in order to accomplish the large-scale geometries imposed by the science objectives. In addition, the paradigm shift of using a multiple satellite cluster rather than a large, monolithic spacecraft has also been motivated by the expected benefits of increased robustness, greater flexibility, and reduced cost. However, the operational costs of monitoring and commanding a fleet of close-orbiting satellites is likely to be unreasonable unless the onboard software is sufficiently autonomous, robust, and scalable to large clusters. This paper presents the prototype of a system that addresses these objectives-a decentralized guidance and control system that is distributed across spacecraft using a multiple team framework. The objective is to divide large clusters into teams of "manageable" size, so that the communication and computation demands driven by N decentralized units are related to the number of satellites in a team rather than the entire cluster. The system is designed to provide a high level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The distributed guidance and control system will be implemented in an object-oriented style using a messaging architecture for networking and threaded applications (MANTA). In this architecture, tasks may be remotely added, removed, or replaced post launch to increase mission flexibility and robustness. This built-in adaptability will allow software modifications to be made on-orbit in a robust manner. The

  17. Nurse staffing in a decentralized organization: part II.

    Science.gov (United States)

    Althaus, J N; Hardyck, N M; Pierce, P B; Rodgers, M S

    1982-04-01

    It must be emphasized that none of the steps described in this planning process emerged overnight. Rather, they were achieved through a process of evolution, sometimes through trial and error, and always with consultation and participation by many members of the hospital nursing staff. Participation by many in the process of planning for a workable staffing system has been essential to its success. Indeed, creative scheduling by the head nurse is possible because of the way in which the system has been organized. The fact that head nurses are responsible for staffing their own units makes it infinitely easier for them to see what they need to make their units operate effectively and efficiently. Creative scheduling includes the possibility of arranging nurses' hours outside the rigid three-shift schedule used by so many hospitals. Many El Camino nurses now report for work at different hours. In addition, the use of flexible work weeks has proven valuable. Some head nurses now allow for a ten-hour, four-day work week; in emergency staffing situations there have, on occasion, been twelve-hour days. Even as this system evolves, it faces change. Just as the requirements for staff cannot be rigid, so must problem solving be flexible and constantly under review. The fact that El Camino believes in constant monitoring of its system is essential to its success. A key philosophical foundation of decentralization is that it must be subject to change. This is no less true in staffing than in other parts of the decentralization structure. By agreeing that change is constant and necessary and that participation is required at all levels of the staffing planning process, we have constructed the outlines of a system that will work in the future as well as it does in the present. Our system centers around the head nurses. It involves their planning; thus it also involves the support of those members of the nursing staff who can provide essential information. But the decisions

  18. Regional Development and Decentralization – two Options to Overcome Lack of Funding

    Directory of Open Access Journals (Sweden)

    Dubravka JURLINA ALIBEGOVIC

    2014-11-01

    Full Text Available Decentralization can be generally described as a process in which selected functions are assigned to sub-national units. The literature identifies a number of positive consequences of decentralization which all lead to a better satisfaction of citizens’ needs for public services. Although the decentralization process in Croatia started more than ten years ago, it has not yet been completed. While leading to a new allocation of authorities and responsibilities to local government units, the level of fiscal decentralization remained lower than in the EU countries.In this paper we analyze the fiscal capacity of local government units to provide an insight into the main problems of decentralization in Croatia. We show that most local government units have very low fiscal capacity, which is insufficient for financing basic public functions with their own resources. The paper presents the results of a survey relating to the decentralization process conducted among local councilors at the regional level in Croatia. We explore how local councilors at the regional level evaluate different goals of decentralization. With the lack of fiscal capacity in mind, we identify two possible solutions for an optimal provision of public functions. The first one is the level of political will for a joint provision of public functions by different local units, and the second one is a change in the territorial organization of the country. We measure the difference in the attitudes toward these questions across counties.

  19. The tradeoff between centralized and decentralized health services: evidence from rural areas in Mexico.

    Science.gov (United States)

    Vargas Bustamante, Arturo

    2010-09-01

    This study investigates the effectiveness of centralized and decentralized health care providers in rural Mexico. It compares provider performance since both centralized and decentralized providers co-exist in rural areas of the country. The data are drawn from the 2003 household survey of Oportunidades, a comprehensive study of rural families from seven states in Mexico. The analyses compare out-of-pocket health care expenditures and utilization of preventive care among rural households with access to either centralized or decentralized health care providers. This study benefits from differences in timing of health care decentralization and from a quasi-random distribution of providers. Results show that overall centralized providers perform better. Households served by this organization report less regressive out-of-pocket health care expenditures (32% lower), and observe higher utilization of preventive services (3.6% more). Decentralized providers that were devolved to state governments in the early 1980s observe a slightly better performance than providers that were decentralized in the mid-1990s. These findings are robust to decentralization timing, heterogeneity in per capita government health expenditures, state and health infrastructure effects, and other confounders. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  20. Driving up Standards: Civil Service Management and Decentralization: Case Study of Uganda

    Directory of Open Access Journals (Sweden)

    Lazarus Nabaho

    2012-12-01

    Full Text Available There is a consensus that decentralization by devolution leads to improved service delivery, but debate on the appropriate type of personnel arrangements for delivering decentralized services is far from over. Put differently, the discourse on whether civil service management should be decentralized or devolved still rages on. Little wonder that countries which started off with decentralized civil service management models in the 1990s are currently centralizing some aspects of personnel management while others are having centralized and decentralized personnel arrangements operating side by side in sub-national governments. The paper argues that civil service management should be decentralized whenever a country chooses the path of decentralization by devolution. Using Uganda’s example, the paper highlights two major challenges of managing the civil service under separate personnel arrangements: civil service appointments devoid of merit, and the perennial failure to attract and retain qualified human resource. The paper presents proposals on how to ensure meritocracy in appointments and how to bolster attraction and retention of human capital in local governments.

  1. Primary extranodal marginal zone lymphoma of the uvea associated with massive diffuse epibulbar extension and focal infiltration of the optic nerve and meninges, clinically presented as uveitis masquerade syndrome: a case report.

    Science.gov (United States)

    Rasić, D M; Stanković, Z; Terzić, T; Kovacević, D; Koturović, Z; Marković, V

    2010-09-01

    To report a clinical, histopathological and immunohistochemical findings in a case of primary extranodal marginal zone lymphoma of the uvea associated with massive diffuse extraocular episcleral extension and focal infiltration of the optic nerve and meninges, clinically presented as longstanding uveitis masquerade syndrome. Interventional case reports with histopathological correlation. We describe a 80-year-old male patient with a 3-year history of chronic recurrent hypertensive (pan) uveitis associated with ocular pain, unresponsive to topical and systemic anti-inflammatory, immunosuppressive, antibiotic/antiviral and antiglaucomatous therapy. Because the eye was not salvageable with conservative treatment, enucleation of blind and painful eye was performed. Findings from histopathological and immunohistochemistry examination of the enucleated eye showed an extranodal marginal zone lymphoma of the uveal tract with massive epibulbar extension and optic nerve and meningeal penetration. During almost 3 years of clinical course and 6 months after the enucleation, there were no systemic manifestations of lymphoma, and patient has not required subsequent treatment. Primary lymphoproliferative lesions of the uvea, comprising the iris, ciliary body and choroid are very rare, associated with epibulbar extension extremely and with optic nerve and menigeal penetration exceptionally. Despite its rarity, primary lymphoma of the uvea should be included in the differential diagnosis particularly in older patients with longstanding recurrent uveitis.

  2. Is decentralization good for logistics systems? Evidence on essential medicine logistics in Ghana and Guatemala.

    Science.gov (United States)

    Bossert, Thomas J; Bowser, Diana M; Amenyah, Johnnie K

    2007-03-01

    Efficient logistics systems move essential medicines down the supply chain to the service delivery point, and then to the end user. Experts on logistics systems tend to see the supply chain as requiring centralized control to be most effective. However, many health reforms have involved decentralization, which experts fear has disrupted the supply chain and made systems less effective. There is no consensus on an appropriate methodology for assessing the effectiveness of decentralization in general, and only a few studies have attempted to address decentralization of logistics systems. This paper sets out a framework and methodology of a pioneering exploratory study that examines the experiences of decentralization in two countries, Guatemala and Ghana, and presents suggestive results of how decentralization affected the performance of their logistics systems. The analytical approach assessed decentralization using the principal author's 'decision space' approach, which defines decentralization as the degree of choice that local officials have over different health system functions. In this case the approach focused on 15 different logistics functions and measured the relationship between the degree of choice and indicators of performance for each of the functions. The results of both studies indicate that less choice (i.e. more centralized) was associated with better performance for two key functions (inventory control and information systems), while more choice (i.e. more decentralized) over planning and budgeting was associated with better performance. With different systems of procurement in Ghana and Guatemala, we found that a system with some elements of procurement that are centralized (selection of firms and prices fixed by national tender) was positively related in Guatemala but negatively related in Ghana, where a system of 'cash and carry' cost recovery allowed more local choice. The authors conclude that logistics systems can be effectively

  3. Capacity investment and competition in decentralized electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    Fehr, Nils-Henrik von der; Harbord, David Cameron

    1997-11-01

    With particular reference to the recently deregulated and market-based electricity industries in Norway, the UK and elsewhere the report analyses oligopoly entry and capacity investment decisions as a non-cooperative game in a decentralized electricity market. A two-stage game is considered, with multiple capacity types and uncertain demand, in which capacity decisions are made prior to spot-market, or price competition. Equilibrium outcomes for different pricing mechanisms or regulatory regimes are analysed. The following questions are dealt with in particular: Will industry capacity be sufficient to ensure adequate supply security? Does imperfect competition in the spot-market lead to an inefficient mix of base-load and peak-load technologies? How do different regulatory policies affect the market outcomes? 24 refs., 2 figs., 1 tab.

  4. Decentralization of Decision Authority in Complex Task Structures DRUID

    DEFF Research Database (Denmark)

    Dobrajska, Magdalena; Billinger, Stephan; Karim, Samina

    We investigate tradeoffs associated with delegating authority over multiple interrelated decisions in a complex task structure. The empirical setting is a business process of a global Fortune 50 firm. The firm decentralized its organization and redefined decision authority across organizational......-relevant knowledge, the matching of required knowledge and manager?s expertise, and information processing intensity affect (a) the occurrence of delegation, and (b), if delegation occurs, how far down the organizational hierarchy authority is delegated. We discuss how these findings complement existing theories...... hierarchies between 2008 and 2011. We employ regression analysis of micro-level data on the organization design of 761 decision tasks and we investigate the allocation of decision authority at the level of all observable individual decision tasks. Our findings show how the specialization of decision...

  5. DECENTRALIZED MULTI-ROBOT PLANNING TO EXPLORE AND PERCEIVE

    Directory of Open Access Journals (Sweden)

    Laetitia Matignon

    2015-06-01

    Full Text Available In a recent French robotic contest, the objective was to develop a multi-robot system able to autonomously map and explore an unknown area while also detecting and localizing objects. As a participant in this challenge, we proposed a new decentralized Markov decision process (Dec-MDP resolution based on distributed value functions (DVF to compute multi-robot exploration strategies. The idea is to take advantage of sparse interactions by allowing each robot to calculate locally a strategy that maximizes the explored space while minimizing robots interactions. In this paper, we propose an adaptation of this method to improve also object recognition by integrating into the DVF the interest in covering explored areas with photos. The robots will then act to maximize the explored space and the photo coverage, ensuring better perception and object recognition.

  6. Decentralized estimation of sensor systematic error andtarget state vector

    Institute of Scientific and Technical Information of China (English)

    贺明科; 王正明; 朱炬波

    2003-01-01

    An accurate estimation of the sensor systematic error is significant for improving the performance of target tracking system. The existing methods usually append the bias states directly to the variable states to form augmented state vectors and utilize the conventional Kalman estimator to achieve state vectors estimate. So doing is expensive in computation, and much work is devoted to decoupling variable states and systematic error. But the decentralied estimation of systematic errors and reduction of the amount of computation as well as decentralied track fusion are far from being realized. This paper addresses distributed track fusion problem in multi-sensor tracking system in the presence of sensor bias. By this method, variable states and systematic error is decoupled. Decentralized systematic error estimation and track fusion are achieved. Simulation results verify that this method can get accurate estimation of systematic error and state vector.

  7. Centralization or decentralization of technology information: future cooperation or competition

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, E.

    1982-01-01

    Although advocates of decentralization cite the values of individual privacy, human dimensions, and potential for creativity and innovation, the advent of microcomputer technology during the past five years brought the first real reversal of the trend toward centralization. Both systems have their economic, social, and technical consequences. Centralization, for example, has the advantages of scale economy, coordination, and the control of lower-level activities to meet higher-level goals. At issue are the problems of sharing and data distribution. A hybridism of systems will take place in the next five years along with a conversion to smaller, more-flexible and personal systems as microprocessors come down in price. Application will determine the extent of centralization for each system. The shift will affect education, international forums, the type of work conducted in the service sector, and life styles, and will introduce legal, political, and organizational problems. 7 references. (DCK)

  8. Techno-economic analysis of decentralized biomass processing depots.

    Science.gov (United States)

    Lamers, Patrick; Roni, Mohammad S; Tumuluru, Jaya S; Jacobson, Jacob J; Cafferty, Kara G; Hansen, Jason K; Kenney, Kevin; Teymouri, Farzaneh; Bals, Bryan

    2015-10-01

    Decentralized biomass processing facilities, known as biomass depots, may be necessary to achieve feedstock cost, quantity, and quality required to grow the future U.S. bioeconomy. In this paper, we assess three distinct depot configurations for technical difference and economic performance. The depot designs were chosen to compare and contrast a suite of capabilities that a depot could perform ranging from conventional pelleting to sophisticated pretreatment technologies. Our economic analyses indicate that depot processing costs are likely to range from ∼US$30 to US$63 per dry metric tonne (Mg), depending upon the specific technology implemented and the energy consumption for processing equipment such as grinders and dryers. We conclude that the benefits of integrating depots into the overall biomass feedstock supply chain will outweigh depot processing costs and that incorporation of this technology should be aggressively pursued.

  9. Linear decentralized systems with special structure. [for twin lift helicopters

    Science.gov (United States)

    Martin, C. F.

    1982-01-01

    Certain fundamental structures associated with linear systems having internal symmetries are outlined. It is shown that the theory of finite-dimensional algebras and their representations are closely related to such systems. It is also demonstrated that certain problems in the decentralized control of symmetric systems are equivalent to long-standing problems of linear systems theory. Even though the structure imposed arose in considering the problems of twin-lift helicopters, any large system composed of several identical intercoupled control systems can be modeled by a linear system that satisfies the constraints imposed. Internal symmetry can be exploited to yield new system-theoretic invariants and a better understanding of the way in which the underlying structure affects overall system performance.

  10. Mitigation of Remedial Action Schemes by Decentralized Robust Governor Control

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo, Marcelo A.; Marinovici, Laurentiu D.; Lian, Jianming; Kalsi, Karanjit; Du, Pengwei

    2014-04-15

    This paper presents transient stability improvement by a new distributed hierarchical control architecture (DHC). The integration of remedial action schemes (RAS) to the distributed hierarchical control architecture is studied. RAS in power systems are designed to maintain stability and avoid undesired system conditions by rapidly switching equipment and/or changing operating points according to predetermined rules. The acceleration trend relay currently in use in the US western interconnection is an example of RAS that trips generators to maintain transient stability. The link between RAS and DHC is through fast acting robust turbine/governor control that can also improve transient stability. In this paper, the influence of the decentralized robust turbine/governor control on the design of RAS is studied. Benefits of combining these two schemes are increasing power transfer capability and mitigation of RAS generator tripping actions; the later benefit is shown through simulations.

  11. Integration of Decentralized Thermal Storages Within District Heating (DH Networks

    Directory of Open Access Journals (Sweden)

    Schuchardt Georg K.

    2016-12-01

    Full Text Available Thermal Storages and Thermal Accumulators are an important component within District Heating (DH systems, adding flexibility and offering additional business opportunities for these systems. Furthermore, these components have a major impact on the energy and exergy efficiency as well as the heat losses of the heat distribution system. Especially the integration of Thermal Storages within ill-conditioned parts of the overall DH system enhances the efficiency of the heat distribution. Regarding an illustrative and simplified example for a DH system, the interactions of different heat storage concepts (centralized and decentralized and the heat losses, energy and exergy efficiencies will be examined by considering the thermal state of the heat distribution network.

  12. Decentralized Control of Dynamic Routing with a Neural Network Algorithm

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A state-dependent routing algorithm based on the neural network model, which takes advantage of other dynamic routing algorithm for circuit-switched network, is given in [1]. But, the Algorithm in [1] is a centralized control model with complex O (N7), therefore, is difficult to realize by hardware. A simplified algorithm is put forward in this paper, in which routing can be controlled decentralizedly, and its complexity is reduced to O (10N3). Computer simulations are made in a fully connected test network with eight nodes. The results show that the centralized control model has very effective performance that can match RTNR, and the centralized control model is not as good as the centralized one but better than DAR-1.

  13. A Novel Decentralized Economic Operation in Islanded AC Microgrids

    Directory of Open Access Journals (Sweden)

    Hua Han

    2017-06-01

    Full Text Available Droop schemes are usually applied to the control of distributed generators (DGs in microgrids (MGs to realize proportional power sharing. The objective might, however, not suit MGs well for economic reasons. Addressing that issue, this paper proposes an alternative droop scheme for reducing the total active generation costs (TAGC. Optimal economic operation, DGs’ capacity limitations and system stability are fully considered basing on DGs’ generation costs. The proposed scheme utilizes the frequency as a carrier to realize the decentralized economic operation of MGs without communication links. Moreover, a fitting method is applied to balance DGs’ synchronous operation and economy. The effectiveness and performance of the proposed scheme are verified through simulations and experiments.

  14. DARC: Next generation decentralized control framework for robot applications

    DEFF Research Database (Denmark)

    Kjærgaard, Morten; Andersen, Nils Axel; Ravn, Ole

    2013-01-01

    This paper presents DARC, a next generation control framework for robot applications. It is designed to be equally powerful in prototyping research projects and for building serious commercial robots running on low powered embedded hardware, thus closing the gab between research and industry. It ....... It incorporates several new techniques such as a decentralized peer-to-peer architecture, transparent network distribution of the control system, and automatic run-time supervision to guarantee robustness.......This paper presents DARC, a next generation control framework for robot applications. It is designed to be equally powerful in prototyping research projects and for building serious commercial robots running on low powered embedded hardware, thus closing the gab between research and industry...

  15. Decentralized adaptive synchronization of an uncertain complex delayed dynamical network

    Institute of Scientific and Technical Information of China (English)

    Weisong ZHONG; Jun ZHAO; Georgi M.DIMIROVSKI

    2009-01-01

    In this paper,we investigate the locally and globally adaptive synchronization problem for an uncertain complex dynamical network with time-varying coupling delays based on the decentralized control.The coupling terms here are bounded by high-order polynomials with known gains that are ubiquitous in a large class of complex dynamical networks.We generalize the usual technology of searching for an appropriate coordinates transformation to change the network dynamics into a series of decoupled lower-dimensional systems.Several adaptive synchronization criteria are derived by constructing the Lyapunov-Krasovskii functional and Barbalat lemma,and the proposed criteria are simple in form and convenient for the practical engineering design.Numerical simulations illustrated by a nearest-neighbor coupling network verify the effectiveness of the proposed synchronization scheme.

  16. DEPAS: A Decentralized Probabilistic Algorithm for Auto-Scaling

    CERN Document Server

    Calcavecchia, Nicolo M; Di Nitto, Elisabetta; Dubois, Daniel J; Petcu, Dana

    2012-01-01

    The dynamic provisioning of virtualized resources offered by cloud computing infrastructures allows applications deployed in a cloud environment to automatically increase and decrease the amount of used resources. This capability is called auto-scaling and its main purpose is to automatically adjust the scale of the system that is running the application to satisfy the varying workload with minimum resource utilization. The need for auto-scaling is particularly important during workload peaks, in which applications may need to scale up to extremely large-scale systems. Both the research community and the main cloud providers have already developed auto-scaling solutions. However, most research solutions are centralized and not suitable for managing large-scale systems, moreover cloud providers' solutions are bound to the limitations of a specific provider in terms of resource prices, availability, reliability, and connectivity. In this paper we propose DEPAS, a decentralized probabilistic auto-scaling algorit...

  17. Transnationalism and the Decentralization of the Global Film Industry

    Directory of Open Access Journals (Sweden)

    Jordi Codó Martínez

    2015-03-01

    Full Text Available As in other aspects of society (politics, economics, the film industry appears to be undergoing a process of decentralization (still in its infancy by which Asia is, if not overtaking, at least matching its level of influence with that of European and American powers. Much of the impetus shifting this balance corresponds to China. The spectacular growth of China‟s domestic market is concentrating a substantial part of the global film business within this Asian giant, resulting in the still sector leader, the United States, conditioning its production in order to maximize profits in that territory. Resolute internationalization policies are also helping Chinese companies gain a foothold in Western countries conditioning film content there, although paradoxically their audiences remain unwilling to consume cinema that is culturally foreign. This essay will attempt to explain how all this has occurred.

  18. Numerical analysis of residual stresses in preforms of stress applying part for PANDA-type polarization maintaining optical fibers in view of technological imperfections of the doped zone geometry

    Science.gov (United States)

    Trufanov, Aleksandr N.; Trufanov, Nikolay A.; Semenov, Nikita V.

    2016-09-01

    The experimental data analysis of the stress applying rod section geometry for the PANDA-type polarization maintaining optical fiber has been performed. The dependencies of the change in the radial dimensions of the preform and the doping boundary on the angular coordinate have been obtained. The original algorithm of experimental data statistic analysis, which enables determination of the specimens' characteristic form of section, has been described. The influence of actual doped zone geometry on the residual stress fields formed during the stress rod preform fabrication has been investigated. It has been established that the deviation of the boundary between pure silica and the doped zone from the circular shape results in dissymmetry and local concentrations of the residual stress fields along the section, which can cause preforms destruction at high degrees of doping. The observed geometry deviations of up to 10% lead to the increase of the maximum stress intensity value by over 20%.

  19. Decentred Centre in John Fowles’s The Magus

    Directory of Open Access Journals (Sweden)

    Aleks Matosoğlu

    2015-12-01

    Full Text Available Decentred Centre in John Fowles’sThe Magus Abstract John Fowles’ The Magus (1966 has been the focus of criticism for many years. This study regards the character of Conchis as a decentred “centre” in the structure of the novel and as in the experience of the contemporary humanity. Conchis becomes in the eyes of Nicholas an all-knowing figure, an accumulation of Western thought since the Greek civilization. He produces signs to be read as he himself becomes a body of various signs that construct him as the metaphysical centre that Western thinkers have relied upon. His narration becomes superior to Nicholas’ and he himself becomes only a narrative voice. The voice from the times of Plato has been considered as a direct expression of the thoughts in one’s mind and thus superior to writing that is permeated with the undecidability of meaning in the absence of the speaker and the addressee. In the novel, words as an endless play of metaphors take the place of voice. There is no knowable reality outside the play words or metaphors which is an endless chain of signifiers that lead to other signifiers. Every time Nicholas turns to Conchis to find the centre outside the play of the language, he finds other signifiers. Thus, Conchis as a meaning-making centre is dethroned. He is not the sole operator of the masks that divert from their presumed original target when they are read. Nicholas is just another production of the literary tradition who reads the signs only to produce other signs. Conchis in the beginning of the novel renounces fiction for science but along the course of the novel, we see that words are never reliable whether in fiction or in science.

  20. Towards a personalized Internet: a case for a full decentralization.

    Science.gov (United States)

    Kermarrec, Anne-Marie

    2013-03-28

    The Web has become a user-centric platform where users post, share, annotate, comment and forward content be it text, videos, pictures, URLs, etc. This social dimension creates tremendous new opportunities for information exchange over the Internet, as exemplified by the surprising and exponential growth of social networks and collaborative platforms. Yet, niche content is sometimes difficult to retrieve using traditional search engines because they target the mass rather than the individual. Likewise, relieving users from useless notification is tricky in a world where there is so much information and so little of interest for each and every one of us. We argue that ultra-specific content could be retrieved and disseminated should search and notification be personalized to fit this new setting. We also argue that users' interests should be implicitly captured by the system rather than relying on explicit classifications simply because the world is by nature unstructured, dynamic and users do not want to be hampered in their actions by a tight and static framework. In this paper, we review some existing personalization approaches, most of which are centralized. We then advocate the need for fully decentralized systems because personalization raises two main issues. Firstly, personalization requires information to be stored and maintained at a user granularity which can significantly hurt the scalability of a centralized solution. Secondly, at a time when the 'big brother is watching you' attitude is prominent, users may be more and more reluctant to give away their personal data to the few large companies that can afford such personalization. We start by showing how to achieve personalization in decentralized systems and conclude with the research agenda ahead.

  1. Generic, scalable and decentralized fault detection for robot swarms

    Science.gov (United States)

    Christensen, Anders Lyhne; Timmis, Jon

    2017-01-01

    Robot swarms are large-scale multirobot systems with decentralized control which means that each robot acts based only on local perception and on local coordination with neighboring robots. The decentralized approach to control confers number of potential benefits. In particular, inherent scalability and robustness are often highlighted as key distinguishing features of robot swarms compared with systems that rely on traditional approaches to multirobot coordination. It has, however, been shown that swarm robotics systems are not always fault tolerant. To realize the robustness potential of robot swarms, it is thus essential to give systems the capacity to actively detect and accommodate faults. In this paper, we present a generic fault-detection system for robot swarms. We show how robots with limited and imperfect sensing capabilities are able to observe and classify the behavior of one another. In order to achieve this, the underlying classifier is an immune system-inspired algorithm that learns to distinguish between normal behavior and abnormal behavior online. Through a series of experiments, we systematically assess the performance of our approach in a detailed simulation environment. In particular, we analyze our system’s capacity to correctly detect robots with faults, false positive rates, performance in a foraging task in which each robot exhibits a composite behavior, and performance under perturbations of the task environment. Results show that our generic fault-detection system is robust, that it is able to detect faults in a timely manner, and that it achieves a low false positive rate. The developed fault-detection system has the potential to enable long-term autonomy for robust multirobot systems, thus increasing the usefulness of robots for a diverse repertoire of upcoming applications in the area of distributed intelligent automation. PMID:28806756

  2. Comment on ‘Energy and air emission implications of a decentralized wastewater system’

    Science.gov (United States)

    Vedachalam, Sridhar; Riha, Susan J.

    2013-03-01

    In the article ‘Energy and air emission implications of a decentralized wastewater system’ published in Environmental Research Letters (2012 Environ. Res. Lett. 7 024007), Shehabi et al compared a decentralized and a centralized system on the basis of energy use, greenhouse gas emissions and air pollutants, and claimed that economies of scale lower the environmental impacts from a centralized system on a per-volume basis. In this comment, we present literature and data from New York State, USA to argue that the authors’ comparison between a small decentralized system (0.015 MGD) and a large centralized system (66.5 MGD) is unconventional and inappropriate.

  3. Decentralized energy: technology assessment and systems description. [Potential for implementation for years 2000 and 2025

    Energy Technology Data Exchange (ETDEWEB)

    Reckard, M K

    1979-06-01

    Decentralized energy systems and their characteristic features are examined in the report. These systems have been divided into six groups for the purpose of analysis: solar, wind, hydro, biomass, geothermal, and coproduction (total energy). The technical and economic potential for the implementation of these systems is discussed for the years 2000 and 2025. The results of a comparison of base-case and decentralized scenarios for the year 2000, using a computer systems model, are presented. Social and institutional factors are also addressed, both as motivations for and results of energy system decentralization. Appendices are included with more detailed technical information on each of the systems groups.

  4. Decentralized H∞ state feedback control for large-scale interconnected uncertain systems with multiple delays

    Institute of Scientific and Technical Information of China (English)

    陈宁; 桂卫华; 谢永芳

    2004-01-01

    Decentralized H∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition which makes the closed--loop system decentralized asymptotically stable with H∞ performance was derived based on Lyapunov stability theorem. This condition is expressed as the solvability problem of linear matrix inequalities. The method overcomes the limitations of the existing algebraic Riccati equation method. Finally, a numerical example was given to demonstrate the design procedure for the decentralized H∞ state feedback controller.

  5. Targeting heat recovery and reuse in industrial zone

    Directory of Open Access Journals (Sweden)

    Zarić Milana M.

    2017-01-01

    Full Text Available In order to reduce the usage of fossil fuels in industrial sectors by meeting the requirements of production processes, new heat integration and heat recovery approaches are developed. The goal of this study is to develop an approach to increase energy efficiency of an industrial zone by recovering and reusing waste heat via indirect heat integration. Industrial zones usually consist of multiple independent plants, where each plant is supplied by an independent utility system, as a decentralized system. In this study, a new approach is developed to target minimum energy requirements where an industrial zone would be supplied by a centralized utility system instead of decentralized utility system. The approach assumes that all process plants in an industrial zone are linked through the central utility system. This method is formulated as a linear programming problem (LP. Moreover, the proposed method may be used for decision making related to energy integration strategy of an industrial zone. In addition, the proposed method was applied on a case study. The results revealed that saving of fossil fuel could be achieved. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. OI172063

  6. Parapapillary atrophy: histological gamma zone and delta zone.

    Directory of Open Access Journals (Sweden)

    Jost B Jonas

    Full Text Available BACKGROUND: To examine histomorphometrically the parapapillary region in human eyes. METHODOLOGY/PRINCIPAL FINDINGS: The histomorphometric study included 65 human globes (axial length:21-37 mm. On anterior-posterior histological sections, we measured the distance Bruch's membrane end (BME-optic nerve margin ("Gamma zone", BME-retinal pigment epithelium (RPE ("Beta zone", BME-beginning of non-occluded choriocapillaris, and BME-beginning of photoreceptor layer. "Delta zone" was defined as part of gamma zone in which blood vessels of at least 50 µm diameter were not present over a length of >300 µm. Beta zone (mean length:0.35±0.52 mm was significantly (P = 0.01 larger in the glaucoma group than in the non-glaucomatous group. It was not significantly (P = 0.28 associated with axial length. Beta zone was significantly (P = 0.004 larger than the region with occluded choriocapillaris. Gamma zone (mean length:0.63±1.25 mm was associated with axial length (P50 µm diameter within gamma zone was present only in highly axially elongated globes and was not related with glaucoma. Beta zone (Bruch's membrane without RPE was correlated with glaucoma but not with globe elongation. Since the region with occluded choriocapillaris was smaller than beta zone, complete loss of RPE may have occurred before complete choriocapillaris closure.

  7. Decentralized adaptive neural network sliding mode position/force control of constrained reconfigurable manipulators

    Institute of Scientific and Technical Information of China (English)

    李元春; 丁贵彬; 赵博

    2016-01-01

    A decentralized adaptive neural network sliding mode position/force control scheme is proposed for constrained reconfigurable manipulators. Different from the decentralized control strategy in multi-manipulator cooperation, the proposed decentralized position/force control scheme can be applied to series constrained reconfigurable manipulators. By multiplying each row of Jacobian matrix in the dynamics by contact force vector, the converted joint torque is obtained. Furthermore, using desired information of other joints instead of their actual values, the dynamics can be represented as a set of interconnected subsystems by model decomposition technique. An adaptive neural network controller is introduced to approximate the unknown dynamics of subsystem. The interconnection and the whole error term are removed by employing an adaptive sliding mode term. And then, the Lyapunov stability theory guarantees the stability of the closed-loop system. Finally, two reconfigurable manipulators with different configurations are employed to show the effectiveness of the proposed decentralized position/force control scheme.

  8. Endogenous System Microbes as Treatment Process Indicators for Decentralized Non-potable Water Reuse

    Science.gov (United States)

    Monitoring the efficacy of treatment strategies to remove pathogens in decentralized systems remains a challenge. Evaluating log reduction targets by measuring pathogen levels is hampered by their sporadic and low occurrence rates. Fecal indicator bacteria are used in centraliz...

  9. Decentralized system identification for electric power system; Denryoku keito no bunsan system dotei

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, S.; Kanetaka, I. [University of Osaka Prefecture, Osaka (Japan)

    1995-12-20

    The research on decentralized control of electric power system, which has become more complex, is an important subject for tile stabilizing control. In particular since electric power system is a large scale nonlinear control ones, decentralized (not divided) systems with cooperation should be constructed. The purpose of this paper is to present an approach for constructing decentralized systems of electric ponder system. In Chapter 2, swing datas of a three-machine model system are obtained, and in Chapter 3, coefficient parameters of tile model equation based on one-machine infinite bus system with AVR and GOV are estimated by tile least square method. In Chapter 4, the equivalence calculated by using tile estimated values is discussed and also the effect of conditions for the fault is considered. Finally Chapter 5 is devoted to summarizing tile result for the decentralized system identification. 14 refs., 5 figs., 2 tabs.

  10. Engaging Social Capital for Decentralized Urban Stormwater Management (Paper in Non-EPA Proceedings)

    Science.gov (United States)

    Decentralized approaches to urban stormwater management, whereby installations of green infrastructure (e.g., rain gardens, bioswales, constructed wetlands) are dispersed throughout a management area, are cost-effective solutions with co-benefits beyond just water abatement. Inst...

  11. Decentralized Nonlinear Controller Based SiC Parallel DC-DC Converter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is aimed at demonstrating the feasibility of a Decentralized Control based SiC Parallel DC-DC Converter Unit (DDCU) with targeted application for...

  12. The recent process of decentralization and democratic management of education in Brazil

    Science.gov (United States)

    Santos Filho, José Camilo Dos

    1993-09-01

    Brazilian society is beginning a new historical period in which the principle of decentralization is beginning to predominate over centralization, which held sway during the last 25 years. In contrast to recent Brazilian history, there is now a search for political, democratic and participatory decentralization more consonant with grass-roots aspirations. The first section of this article presents a brief analysis of some decentralization policies implemented by the military regime of 1964, and discusses relevant facts related to the resistance of civil society to state authoritarianism, and to the struggle for the democratization and organization of civil society up to the end of the 1970s. The second section analyzes some new experiences of democratic public school administration initiated in the 1970s and 1980s. The final section discusses the move toward decentralization and democratization of public school administration in the new Federal and State Constitutions, and in the draft of the new Law of National Education.

  13. The Politics of Fiscal Decentralization Revisited: a Typology and Comparative Evidence

    Directory of Open Access Journals (Sweden)

    Jorge P. Gordin

    2009-06-01

    Full Text Available Although the practice of fiscal decentralization is worldwide and its implementation and effects vary from country to country, its political significance has been often neglected, or worse, treated as implicit to decentralization. This study considers the sources of politicization of fiscal decentralization, focusing on the determination and manipulation of intergovernmental transfers. It develops a new index of fiscal politicization and proposes an explanatory typology that takes into account subnational transfer dependency and the extent to which transfers are politically determined. This analysis renders a conceptual tool that captures nuanced facts about the intergovernmental level of conflict to a larger extent than conventional measures of fiscal decentralization do. We found that the effects of fiscal dependency are intertwined with political asymmetries derived from legislative overrepresentation of territorial units and intergovernmental bargaining strategies.

  14. Engaging Social Capital for Decentralized Urban Stormwater Management (Paper in Non-EPA Proceedings)

    Science.gov (United States)

    Decentralized approaches to urban stormwater management, whereby installations of green infrastructure (e.g., rain gardens, bioswales, constructed wetlands) are dispersed throughout a management area, are cost-effective solutions with co-benefits beyond just water abatement. Inst...

  15. Multisensor Fault Identification Scheme Based on Decentralized Sliding Mode Observers Applied to Reconfigurable Manipulators

    Directory of Open Access Journals (Sweden)

    Bo Zhao

    2013-01-01

    Full Text Available This paper concerns with a fault identification scheme in a class of nonlinear interconnected systems. The decentralized sliding mode observer is recruited for the investigation of position sensor fault or velocity sensor fault. First, a decentralized neural network controller is proposed for the system under fault-free state. The diffeomorphism theory is utilized to construct a nonlinear transformation for subsystem structure. A simple filter is implemented to convert the sensor fault into pseudo-actuator fault scenario. The decentralized sliding mode observer is then presented for multisensor fault identification of reconfigurable manipulators based on Lyapunov stable theory. Finally, two 2-DOF reconfigurable manipulators with different configurations are employed to verify the effectiveness of the proposed scheme in numerical simulation. The results demonstrate that one joint’s fault does not affect other joints and the sensor fault can be identified precisely by the proposed decentralized sliding mode observer.

  16. The social control of energy: A case for the promise of decentralized solar technologies

    Science.gov (United States)

    Gilmer, R. W.

    1980-05-01

    Decentralized solar technology and centralized electric utilities were contrasted in the ways they assign property rights in capital and energy output; in the assignment of operational control; and in the means of monitoring, policing, and enforcing property rights. An analogy was drawn between the decision of an energy consumer to use decentralized solar and the decision of a firm to vertically integrate, that is, to extend the boundary of a the firm to vertically integrate, that is, to extend the boundary of the firm by making inputs or further processing output. Decentralized solar energy production offers the small energy consumer the chance to cut ties to outside suppliers--to vertically integrate energy production into the home or business. The development of this analogy provides insight into important noneconomic aspects of solar energy, and it points clearly to the lighter burdens of social management offered by decentralized solar technology.

  17. [Decentralization of the health sector in Mexico. Scope and limitations of local health systems].

    Science.gov (United States)

    González-Block, M A

    1992-01-01

    This paper is a product of the reflection on the decentralization and sectorization experiences in Mexico since 1917 with particular emphasis on the 1980s. The historical analysis included the creation of an analytical model designed to identify the relationship between the distinct sanitary policies implemented in Mexico and the tendencies towards decentralization and integration. This analysis is combined with a critical review of the recent decentralization experiences undertaken in the states of Guerrero, Oaxaca and Nuevo León. While comparing Guerrero and Oaxaca, restitution and deconcentration under similar socio-economic conditions were discussed. The comparison between Guerrero and Nuevo Leon allowed the discussion of the benefits and limits of restitution under different socio-economic conditions. In addition, with this model the author discusses a few generalizations regarding the possible future of decentralization.

  18. A Call for Different Styles of Data Management and Institutional Research: Centralized versus Decentralized Planning.

    Science.gov (United States)

    Bryson, Charles H.; Howard, Richard D.

    1979-01-01

    The planning processes at two universities are contrasted as they relate to styles of data management and institutional research required to support two different planning philosophies--centralized planning and decentralized planning. (Author/BH)

  19. Decentralized Output-Feedback Stabilization of Linear Time-invariant Interconnected Systems with Delays

    Energy Technology Data Exchange (ETDEWEB)

    Shim, D.S. [Chung-Ang University, Seoul (Korea, Republic of)

    1998-04-01

    We study the decentralized stabilization problem of linear time-invariant large-scale interconnected systems with delays without any system structure. We obtain sufficient stability conditions for interconnected systems which are equivalent to disturbance attenuation of some scaled system. A decentralized output-feedback controller is obtained using standard H{infinity} control theory. The obtained controller is delay-independent. We also obtain an observer for the interconnected system. (author). 9 refs.

  20. Decentralization's impact on the health workforce: Perspectives of managers, workers and national leaders

    Directory of Open Access Journals (Sweden)

    Kolehmainen-Aitken Riitta-Liisa

    2004-05-01

    Full Text Available Abstract Designers and implementers of decentralization and other reform measures have focused much attention on financial and structural reform measures, but ignored their human resource implications. Concern is mounting about the impact that the reallocation of roles and responsibilities has had on the health workforce and its management, but the experiences and lessons of different countries have not been widely shared. This paper examines evidence from published literature on decentralization's impact on the demand side of the human resource equation, as well as the factors that have contributed to the impact. The elements that make such an impact analysis exceptionally complex are identified. They include the mode of decentralization that a country is implementing, the level of responsibility for the salary budget and pay determination, and the civil service status of transferred health workers. The main body of the paper is devoted to examining decentralization's impact on human resource issues from three different perspectives: that of local health managers, health workers themselves, and national health leaders. These three groups have different concerns in the human resource realm, and consequently, have been differently affected by decentralization processes. The paper concludes with recommendations regarding three key concerns that national authorities and international agencies should give prompt attention to. They are (1 defining the essential human resource policy, planning and management skills for national human resource managers who work in decentralized countries, and developing training programs to equip them with such skills; (2 supporting research that focuses on improving the knowledge base of how different modes of decentralization impact on staffing equity; and (3 identifying factors that most critically influence health worker motivation and performance under decentralization, and documenting the most cost-effective best

  1. Fiscal decentralization and regional disparity: evidence from cross-section and panel data

    OpenAIRE

    Lessmann, Christian

    2009-01-01

    The advantages and disadvantages of public sector decentralization are widely discussed in economics and political science. Some authors argue that decentralization leads to an optimal provision of public services and promotes economic growth, while others emphasize the dangers of competition between subnational governments, especially those associated with interregional redistribution. Using cross-section and panel data for twenty-three OECD countries, from 1982 to 2000, this paper empirical...

  2. Centralized versus Decentralized Provision of Local Public Goods: a Political Economy Analysis

    OpenAIRE

    Besley, Timothy J.; Coate, Stephen

    2000-01-01

    This paper takes a fresh look at the trade-off between centralized and decentralized provision of local public goods. The point of departure is to model a centralized system as one in which public spending is financed by general taxation, but districts can receive different levels of local public goods. In a world of benevolent governments, the disadvantages of centralization stressed in the existing literature disappear, suggesting that the case for decentralization must be driven by politic...

  3. The impact of information and communication technology on decentralization: The role of organizational culture

    OpenAIRE

    Janićijević, Nebojša; Milovanović, Miloš

    2015-01-01

    The paper explores the impact of organizational culture on the effects that the implementation of information and communication technology has on decentralization of organization. The starting assumption is that the implementation of information and communication technology does not have a predetermined and unique impact on centralization or decentralization of organization, but this impact rather depends on the context in which the implementation is performed. Organizational culture has a co...

  4. Organizational precedents for ownership and management of decentralized renewable-energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Meunier, R.; Silversmith, J.A.

    1981-03-01

    Three existing organizational types that meet the decentralization criteria of local consumer ownership and control - cooperatives, Rural Electric Cooperatives, and municipal utilities - are examined. These three organizational precedents are analyzed in terms of their histories, structures, legal powers, sources of capital, and social and political aspects. Examples of related experiments with renewable energy technologies are given, and inferences are drawn regarding the organizations' suitability as vehicles for future implementation of decentralized renewable energy systems.

  5. Decentralized Algorithms for 3D Symmetric Formations in Robotic Networks: a Contraction Theory Approach

    OpenAIRE

    Singh, Sumeet; Schmerling, Edward; Pavone, Marco

    2015-01-01

    This paper presents decentralized algorithms for formation control of multiple robots in three dimensions. Specifically, we leverage the mathematical properties of cyclic pursuit along with results from contraction and partial contraction theory to design decentralized control algorithms that ensure global convergence to symmetric formations. We first consider regular polygon formations as a base case, and then extend the results to Johnson solid and other polygonal mesh formations. The algor...

  6. Key Technologies for Decentralized Control Platform with Dynamic Evolution for Railway Transportation System

    Institute of Scientific and Technical Information of China (English)

    Tan Yongdong; GuiXun; Qian Qingquan

    2006-01-01

    Key technologies as well as their principles were discussed for a decentralized control platform capable of dynamic evolution.The primary content includes the automatic decision-making mechanism and the algorithm of the control center migration, the principle and technology of system self-monitoring, the principle and technology of the switch-mode of remote control station, the information transmission technology, and the data consistency technology. These key technologies have shown a series of advanced characteristics for decentralized control platform.

  7. Guidelines on the Implementation of the Decentralization Principle in Local Public Administration Management

    OpenAIRE

    Bilouseac Irina; Zaharia Petronela

    2012-01-01

    Are of recent date the multiple attempts of reformation and modernization of the public administration. An important objective of the process of reformation oversees the implementation of the decentralization measures to make the public administration in general more efficient. The current article brings to the attention of the readers the pros but also the cons that the application of the principle of decentralization may bring. As a basic rule in the organizing function of the local adminis...

  8. Decentralized Event-Based Communication Strategy on Leader-Follower Consensus Control

    OpenAIRE

    Duosi Xie; Xiaochun Yin; Jianquan Xie

    2016-01-01

    This paper addresses the leader-follower consensus problem of networked systems by using a decentralized event-based control strategy. The event-based control strategy makes the controllers of agents update at aperiodic event instants. Two decentralized event functions are designed to generate these event instants. In particular, the second event function only uses its own information and the neighbors’ states at their latest event instants. By using this event function, no continuous communi...

  9. Attitudes of pharmacists and nurses toward interprofessional relations and decentralized pharmaceutical services.

    Science.gov (United States)

    Thompson, D F; Kaczmarek, E R; Hutchinson, R A

    1988-02-01

    Pharmacists' and nurses' attitudes toward pharmacist-nurse relations and pharmaceutical services were surveyed before and after the implementation of satellite pharmacies at a 600-bed teaching hospital. The same questionnaire was distributed two months before decentralization (phase 1) and nine months after decentralization was completed (phase 2). Sixty questions about the pharmacy services and the drug treatment process were to be answered using a seven-point, Likert-type scale. Overall response rates for the two phases were 62% and 45%, respectively. Pharmacists' satisfaction with all measured aspects of pharmaceutical services increased after decentralization of services; nurses' satisfaction increased for all measures except pharmacist-conducted medication histories. Pharmacists' satisfaction with the nursing department was greater after decentralized services were implemented. Most aspects of role conflict, one of four measured antecedents to interdepartmental conflict, improved subsequent to decentralization of services. Because of changes in personnel between the two phases of the study, the results may represent the opinions of different people, rather than actual changes in satisfaction. The attitudes of nurses and pharmacists toward overall distributive pharmaceutical services and toward certain aspects of interprofessional relations improved after pharmaceutical services were decentralized.

  10. Economic Inequalities and the Level of Decentralization in European Countries: Cluster Analysis

    Directory of Open Access Journals (Sweden)

    Laboutková Šárka

    2016-12-01

    Full Text Available This submitted article identifies relations between the degree of decentralization and economic imbalances on the basis of a cluster (exploratory analysis. Two indicators have been chosen for measuring economic inequalities: an indicator of dispersion of regional GDP per capita as representative of the performance imbalances within countries (it measures the economic development gap among regions in European countries; and a multidimensional inequality-adjusted human development index as representative of inequalities in the distribution of wealth in the countries. Decentralization is measured by means of a decentralization index, which contains both quantitative and qualitative components. Although groups of countries characterised by a high degree of decentralization do not necessarily show the lowest degrees of economic imbalances, it is however possible to conclude that the countries in groups with a higher degree of decentralization are among those countries with more favourable values of the economic imbalances indicators monitored. As a part of the research, two clusters of countries were identified which are identical in their degree of decentralization, but differ in the results connected with economic imbalances. The differences are caused by different institutional qualities in the two groups.

  11. [Optimisation of the visualisation technique for optical paths through intraocular lenses for characterisation of multifocal imaging properties of Fresnel-zone plates].

    Science.gov (United States)

    Reiß, S; Forbrig, J; Guthoff, R F; Terwee, T; Stolz, H; Siewert, S; El-Tamer, A; Hinze, U; Chichkov, B N; Stachs, O

    2014-12-01

    The utilisation of the diffractive properties of Fresnel zone plates offers the possibility of intraocular lens designs with multiple foci. Such intraocular lenses can be manufactured by two-photon polymerisation (2PP). This paper explains the underlying concept and shows the principles for visualisation of the focus properties of such implants.

  12. Agricultural and forestry residues for decentralized energy generation in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Missagia, Bruna

    2011-10-11

    Regular electricity access is a key element for the economic development and social welfare of rural areas. Decentralized energy generation has the advantage of using local resources, increasing employment and reducing transmission and distribution losses. Brazil is a tropical country, endowed with vast arable land, plentiful precipitation levels, and a large supply of human labour. Furthermore, it has strong regional distinctions with geographical, cultural and economical differences. Forestry and agriculture, important activities in the Brazilian economy, are dependent on local people and are deeply connected to traditions, nature and culture. Furthermore, these activities generate a significant amount of residues that could be used in conversion technologies for biomass, based on type, availability and market demand. When biomass were used to generate energy locally, community members could have business opportunities, improving local economy and life quality of individuals while diversifying the Brazilian energy matrix, which is mostly based on hydropower. Alternatives for implementing small-scale decentralized biomass schemes are dependent on the screening of the existing biomass supply chains, the implementation of adapted technologies for local conditions and the exploration of local resources. The present research carried out a detailed field work in order to evaluate the potential of Brazilian biomass in different regions. The author identified crucial needs, usual constraints and possible challenges of rural electrification and economic development in Brazil. Several case studies and social groups were investigated in the Federal States of Minas Gerais, Sao Paulo and Para to identify different resource management strategies, which biomass technology was applied and the needs of the local population. It was concluded that the compaction of biomass to generate solid biofuels with uniform properties could be a cost-effective alternative for communities

  13. Decentralized Monitoring and Control of Electric Power Distribution System with a use case of Community Energy Storage System

    Science.gov (United States)

    Huq, Kazi Mohammad Moyeenull

    This work focuses on the platform and framework required for developing decentralized monitoring and control applications for a distribution system. Decentralized control of Community Energy Storage (CES) devices has been considered as a use case. The first chapter gives an overview of energy management system and applications. Then the development of centralized and decentralized CES control applications are discussed. The next chapters discusses the software architecture of a typical centralized SCADAEMS platform and outlines the architecture required for a decentralized platform. Then, suitability of IEC 61850 standard for decentralized monitoring and control is investigated and an approach to developing decentralized applications in IEC 61850 enabled environment is proposed and demonstrated. Finally, CIM standard is reviewed for exchanging power system topology information for distributed control.

  14. Integrating Decentralized Indoor Evacuation with Information Depositories in the Field

    Directory of Open Access Journals (Sweden)

    Haifeng Zhao

    2017-07-01

    Full Text Available The lonelier evacuees find themselves, the riskier become their wayfinding decisions. This research supports single evacuees in a dynamically changing environment with risk-aware guidance. It deploys the concept of decentralized evacuation, where evacuees are guided by smartphones acquiring environmental knowledge and risk information via exploration and knowledge sharing by peer-to-peer communication. Peer-to-peer communication, however, relies on the chance that people come into communication range with each other. This chance can be low. To bridge between people being not at the same time at the same places, this paper suggests information depositories at strategic locations to improve information sharing. Information depositories collect the knowledge acquired by the smartphones of evacuees passing by, maintain this information, and convey it to other passing-by evacuees. Multi-agent simulation implementing these depositories in an indoor environment shows that integrating depositories improves evacuation performance: It enhances the risk awareness and consequently increases the chance that people survive and reduces their evacuation time. For evacuating dynamic events, deploying depositories at staircases has been shown more effective than deploying them in corridors.

  15. Decentring the Human? Towards a Post- Anthropocentric Standpoint Theory

    Directory of Open Access Journals (Sweden)

    AnaLouise Keating

    2013-01-01

    Full Text Available Drawing on recent developments in virology and the work of Chicana queer-feminist Gloria Anzaldúa, this article explores the possibility of shifting from anthropocentric epistemologies (including feminist standpoint theories into more expansive, decentralized modes of knowledge production which are neither entirely human-centered nor fully post-human. We explore this shift through several parts: (1 A brief overview of recent critiques of anthropocentrism and the limitations in mainstream feminist standpoint theory’s ability to overcome this anthropocentrism; (2 an exploration of recent developments in virology’s promising alternatives to anthropocentrism’s narrow definition of the human; and (3 an analysis of Anzaldúa’s innovative nepantlera subjectivity and onto-epistemology as seen in her theory of conocimiento. Because scholars have yet to examine the post-anthropocentric (and posthumanist dimensions of Anzaldúa’s thought, but instead generally categorize her epistemology as an ethnic-specific feminist standpoint theory, her work offers a unique point of entry into these investigations.

  16. Decentralized control of multi-agent aerial transportation system

    KAUST Repository

    Toumi, Noureddine

    2017-04-01

    Autonomous aerial transportation has multiple potential applications including emergency cases and rescue missions where ground intervention may be difficult. In this context, the following work will address the control of multi-agent Vertical Take-off and Landing aircraft (VTOL) transportation system. We develop a decentralized method. The advantage of such a solution is that it can provide better maneuverability and lifting capabilities compared to existing systems. First, we consider a cooperative group of VTOLs transporting one payload. The main idea is that each agent perceive the interaction with other agents as a disturbance while assuming a negotiated motion model and imposing certain magnitude bounds on each agent. The theoretical model will be then validated using a numerical simulation illustrating the interesting features of the presented control method. Results show that under specified disturbances, the algorithm is able to guarantee the tracking with a minimal error. We describe a toolbox that has been developed for this purpose. Then, a system of multiple VTOLs lifting payloads will be studied. The algorithm assures that the VTOLs are coordinated with minimal communication. Additionally, a novel gripper design for ferrous objects is presented that enables the transportation of ferrous objects without a cable. Finally, we discuss potential connections to human in the loop transportation systems.

  17. THE IMPACTS OF PRICING SCHEMES ON DECENTRALIZED ASSEMBLY SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Li JIANG

    2008-01-01

    We study an assembly system where one assembler produces a final product to satisfy the price sensitive and uncertain demands.One unit of final product needs inputs from n complementary components each provided from a distinct supplier.The assembler orders from the suppliers and their relationships are governed by price-only contracts.The assembler practices two alternative pricing schemes:a fixed pricing scheme by which she fixes a retail price in all market situations.and a responsive pricing scheme by which she adjusts retail prices after observing actual demand curves.We find that,when the assembler practices the two pricing schemes,the suppliers charge the same wholesale prices,channel profit is allocated among the firms according to the same proportions,and the relative performances of the system under decentralized decision makings with respect to those under centralized decision makings are the same.Furthermore,responsive pricing improves the assembler's absolute performance,and the gains pass over to the suppliers in terms of higher profits and to the customers in terms of enhanced product availability and lowered market price.

  18. Decentralized real-time simulation of forest machines

    Science.gov (United States)

    Freund, Eckhard; Adam, Frank; Hoffmann, Katharina; Rossmann, Juergen; Kraemer, Michael; Schluse, Michael

    2000-10-01

    To develop realistic forest machine simulators is a demanding task. A useful simulator has to provide a close- to-reality simulation of the forest environment as well as the simulation of the physics of the vehicle. Customers demand a highly realistic three dimensional forestry landscape and the realistic simulation of the complex motion of the vehicle even in rough terrain in order to be able to use the simulator for operator training under close-to- reality conditions. The realistic simulation of the vehicle, especially with the driver's seat mounted on a motion platform, greatly improves the effect of immersion into the virtual reality of a simulated forest and the achievable level of education of the driver. Thus, the connection of the real control devices of forest machines to the simulation system has to be supported, i.e. the real control devices like the joysticks or the board computer system to control the crane, the aggregate etc. Beyond, the fusion of the board computer system and the simulation system is realized by means of sensors, i.e. digital and analog signals. The decentralized system structure allows several virtual reality systems to evaluate and visualize the information of the control devices and the sensors. So, while the driver is practicing, the instructor can immerse into the same virtual forest to monitor the session from his own viewpoint. In this paper, we are describing the realized structure as well as the necessary software and hardware components and application experiences.

  19. Randomized vs. orthogonal spectrum allocation in decentralized networks: Outage Analysis

    CERN Document Server

    Moshksar, Kamyar; Khandani, Amir K

    2009-01-01

    We address a decentralized wireless communication network with a fixed number $u$ of frequency sub-bands to be shared among $N$ transmitter-receiver pairs. It is assumed that the number of users $N$ is a random variable with a given distribution and the channel gains are quasi-static Rayleigh fading. The transmitters are assumed to be unaware of the number of active users in the network as well as the channel gains and not capable of detecting the presence of other users in a given frequency sub-band. Moreover, the users are unaware of each other's codebooks and hence, no multiuser detection is possible. We consider a randomized Frequency Hopping (FH) scheme in which each transmitter randomly hops over a subset of the $u$ sub-bands from transmission to transmission. Developing a new upper bound on the differential entropy of a mixed Gaussian random vector and using entropy power inequality, we offer a series of lower bounds on the achievable rate of each user. Thereafter, we obtain lower bounds on the maximum...

  20. A robust decentralized load frequency controller for interconnected power systems.

    Science.gov (United States)

    Dong, Lili; Zhang, Yao; Gao, Zhiqiang

    2012-05-01

    A novel design of a robust decentralized load frequency control (LFC) algorithm is proposed for an inter-connected three-area power system, for the purpose of regulating area control error (ACE) in the presence of system uncertainties and external disturbances. The design is based on the concept of active disturbance rejection control (ADRC). Estimating and mitigating the total effect of various uncertainties in real time, ADRC is particularly effective against a wide range of parameter variations, model uncertainties, and large disturbances. Furthermore, with only two tuning parameters, the controller provides a simple and easy-to-use solution to complex engineering problems in practice. Here, an ADRC-based LFC solution is developed for systems with turbines of various types, such as non-reheat, reheat, and hydraulic. The simulation results verified the effectiveness of the ADRC, in comparison with an existing PI-type controller tuned via genetic algorithm linear matrix inequalities (GALMIs). The comparison results show the superiority of the proposed solution. Moreover, the stability and robustness of the closed-loop system is studied using frequency-domain analysis.

  1. Decentralized autonomous planning of cluster reconfiguration for fractionated spacecraft

    Science.gov (United States)

    Chu, Jing; Guo, Jian; Gill, Eberhard

    2016-06-01

    Autonomous cluster operation such as cluster reconfiguration is one of the enabling technologies for fractionated spacecraft. By virtue of the multi-agent system theory, this paper presents an organizational architecture for fractionated spacecraft, which not only enables autonomous cluster operations but also facilitates its non-traditional attributes. Within this organizational architecture, a decentralized framework is proposed to solve cluster reconfiguration problems based on primal and dual decomposition, where subgradient methods are adopted to include reconfiguration cases with non-differentiable objectives. Two typical constraints are considered: final configuration constraints representing coupling variables and collision avoidance constraints representing coupling constraints, both of which are non-convex. General schemes are proposed to convexify those constraints via the linearization and convex restriction technology. Then final configuration constraints are tackled by primal decomposition, while collision avoidance constraints by dual decomposition. To the end, multi-level primal and dual decompositions are employed to solve reconfiguration problems with both coupling variables and coupling constraints. For illustration an example of in-plane cluster reconfiguration is solved and compared with the centralized approach the solution is optimal.

  2. Decentralized Cooperative Localization Approach for Autonomous Multirobot Systems

    Directory of Open Access Journals (Sweden)

    Thumeera R. Wanasinghe

    2016-01-01

    Full Text Available This study proposes the use of a split covariance intersection algorithm (Split-CI for decentralized multirobot cooperative localization. In the proposed method, each robot maintains a local cubature Kalman filter to estimate its own pose in a predefined coordinate frame. When a robot receives pose information from neighbouring robots, it employs a Split-CI based approach to fuse this received measurement with its local belief. The computational and communicative complexities of the proposed algorithm increase linearly with the number of robots in the multirobot systems (MRS. The proposed method does not require fully connected synchronous communication channels between robots; in fact, it is applicable for MRS with asynchronous and partially connected communication networks. The pose estimation error of the proposed method is bounded. As the proposed method is capable of handling independent and interdependent information of the estimations separately, it does not generate overconfidence state estimations. The performance of the proposed method is compared with several multirobot localization approaches. The simulation and experiment results demonstrate that the proposed algorithm outperforms the single-robot localization algorithms and achieves approximately the same estimation accuracy as the centralized cooperative localization approach, but with reduced computational and communicative cost.

  3. An Enterprise Information Architecture: A Case Study for Decentralized Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R.W.

    1999-06-15

    As enterprises become increasingly information based, making improvements in their information activities is a top priority to assure their continuing competitiveness. A key to achieving these improvements is developing an Enterprise Information Architecture (EIA). An EIA can be viewed as a structured set of multidimensional interrelated elements that support all information processes. The current ad hoc EIAs in place within many enterprises can not meet their future needs because of a lack of a coherent framework, incompatibilities, missing elements, few and poorly understood standards, uneven quality and unnecessary duplications. This paper discusses the EIA developed at Lawrence Livermore National Laboratory as a case study, for other information based enterprises, particularly those with decentralized and autonomous organization structures and cultures. While the architecture is important, the process by which it is developed and sustained over time is equally important. This paper outlines the motivation for an EIA and discusses each of the interacting elements identified. It also presents an organizational structure and processes for building a sustainable EIA activity.

  4. An Enterprise Information Architecture: A Case Study for Decentralized Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R.W.

    1999-09-28

    As enterprises become increasingly information based, making improvements in their information activities is a top priority to assure their continuing competitiveness. A key to achieving these improvements is developing an Enterprise Information Architecture (EIA). An EIA can be viewed as a structured set of multidimensional interrelated elements that support all information processes. The current ad hoc EIAs in place within many enterprises can not meet their future needs because of a lack of a coherent framework, incompatibilities, missing elements, few and poorly understood standards, uneven quality and unnecessary duplications. This paper discusses the EIA developed at Lawrence Livermore National Laboratory as a case study, for other information based enterprises, particularly those with decentralized and autonomous organization structures and cultures. While the architecture is important, the process by which it is developed and sustained over time is equally important. This paper outlines the motivation for an EIA and discusses each of the interacting elements identified. It also presents an organizational structure and processes for building a sustainable EIA activity.

  5. Cross-layer design for decentralized detection in WSNs

    Science.gov (United States)

    Tantawy, Ashraf; Koutsoukos, Xenofon; Biswas, Gautam

    2014-12-01

    A wireless sensor network (WSN) deployed for detection applications has the distinguishing feature that the sensors cooperate to perform the detection task. Therefore, the decoupled and maximum throughput design approaches typically used to design communication networks do not lead to the desired optimal detection performance. Recent work on decentralized detection has addressed the design of media access control (MAC) and routing protocols for detection applications by considering independently the quality of information (QoI), channel state information (CSI), and residual energy information (REI) for each sensor. However, little attention has been given to integrate the three quality measures (QoI, CSI, and REI) in the system design. In this work, we present a cross-layer approach to design a QoI, CSI, and REI-aware transmission control policy (XCP) that coordinates communication between local sensors and the fusion center, in order to maximize the detection performance. We formulate and solve a constrained non-linear optimization problem to find the optimal XCP design variables, for both ALOHA and time-division multiple access (TDMA) sensor networks. We show the detection performance gain compared to the typical decoupled and maximum throughput design approaches, without utilizing additional network resources. We compare ALOHA and TDMA MAC schemes and show the conditions under which each transmission scheme outperforms.

  6. An information-based approach to decentralized multiplatform sensor management

    Science.gov (United States)

    Kreucher, Christopher M.; Kastella, Keith D.; Wegrzyn, John W.; Rickenbach, Brent L.

    2006-05-01

    This paper describes a decentralized low communication approach to multi-platform sensor management. The method is based on a physicomimetic relaxation to a joint information theoretic optimization, which inherits the benefits of information theoretic scheduling while maintaining tractability. The method uses only limited message passing, only neighboring nodes communicate, and each node makes its own sensor management decisions. We show by simulation that the method allows a network of sensor nodes to automatically self organize and perform a global task. In the model problem, a group of unmanned aerial vehicles (UAVs) hover above a ground surveillance region. An initially unknown number of moving ground targets inhabit the region. Each UAV is capable of making noisy measurements of the patch of ground directly below, which provide evidence as to the presence or absence of targets in that sub-region. The goal of the network is to determine the number of targets and their individual states (positions and velocities) in the entire surveillance region through repeated interrogation by the individual nodes. As the individual nodes can only see a small portion of the ground, they must move in a manner that is both responsive to measurements and coordinated with other nodes.

  7. Design and Operation of Decentralized Reservoirs in Urban Drainage Systems

    Directory of Open Access Journals (Sweden)

    Eui Hoon Lee

    2017-03-01

    Full Text Available Poor drainage of urban storm water can lead to urban inundation which presents a risk to people and property. Previous research has presented various measures to prevent and reduce urban flooding and these measures can be classified into costly but effective structural measures, and economical but less effective non-structural measures. This study suggests a new approach to reduce urban flooding by combining structural and non-structural measures in a target watershed in Seoul, South Korea. Inlet design modification in a detention reservoir (Decentralized Reservoir, DR is examined in conjunction with combined inlet/outlet management for the DR. Monitoring nodes used to control DR inlet/outlet operations are selected by locating the first flooding node, maximum flooding node and DR inlet node. This new approach demonstrates outstanding flood volume reduction for historical flooding events that occurred in Seoul during 2010 and 2011. Flood volumes during the 2010 event using the combined inlet/outlet operation in the DR were between 1656 m3 and 1815 m3 compared to a flood volume of 6617 m3 using current DR operation. Finally, the suggested operating level for the DR based on the best hydraulic section, system resilience index, and local regulations is 1.2 m.

  8. Optimizing selection of decentralized stormwater management strategies in urbanized regions

    Science.gov (United States)

    Yu, Z.; Montalto, F.

    2011-12-01

    A variety of decentralized stormwater options are available for implementation in urbanized regions. These strategies, which include bio-retention, porous pavement, green roof etc., vary in terms of cost, ability to reduce runoff, and site applicability. This paper explores the tradeoffs between different types of stormwater control meastures that could be applied in a typical urban study area. A nested optimization strategy first identifies the most cost-effective (e.g. runoff reduction / life cycle cost invested ) options for individual land parcel typologies, and then scales up the results with detailed attention paid to uncertainty in adoption rates, life cycle costs, and hydrologic performance. The study is performed with a custom built stochastic rainfall-runoff model (Monte Carlo techniques are used to quantify uncertainties associated with phased implementation of different strategies and different land parcel typologies under synthetic precipitation ensembles). The results are presented as a comparison of cost-effectiveness over the time span of 30 years, and state an optimized strategy on the cumulative cost-effectiveness over the period.

  9. Optimal and Approximate Q-value Functions for Decentralized POMDPs

    CERN Document Server

    Oliehoek, Frans A; Vlassis, Nikos; 10.1613/jair.2447

    2011-01-01

    Decision-theoretic planning is a popular approach to sequential decision making problems, because it treats uncertainty in sensing and acting in a principled way. In single-agent frameworks like MDPs and POMDPs, planning can be carried out by resorting to Q-value functions: an optimal Q-value function Q* is computed in a recursive manner by dynamic programming, and then an optimal policy is extracted from Q*. In this paper we study whether similar Q-value functions can be defined for decentralized POMDP models (Dec-POMDPs), and how policies can be extracted from such value functions. We define two forms of the optimal Q-value function for Dec-POMDPs: one that gives a normative description as the Q-value function of an optimal pure joint policy and another one that is sequentially rational and thus gives a recipe for computation. This computation, however, is infeasible for all but the smallest problems. Therefore, we analyze various approximate Q-value functions that allow for efficient computation. We descri...

  10. A decentralized software bus based on IP multicas ting

    Science.gov (United States)

    Callahan, John R.; Montgomery, Todd

    1995-01-01

    We describe decentralized reconfigurable implementation of a conference management system based on the low-level Internet Protocol (IP) multicasting protocol. IP multicasting allows low-cost, world-wide, two-way transmission of data between large numbers of conferencing participants through the Multicasting Backbone (MBone). Each conference is structured as a software bus -- a messaging system that provides a run-time interconnection model that acts as a separate agent (i.e., the bus) for routing, queuing, and delivering messages between distributed programs. Unlike the client-server interconnection model, the software bus model provides a level of indirection that enhances the flexibility and reconfigurability of a distributed system. Current software bus implementations like POLYLITH, however, rely on a centralized bus process and point-to-point protocols (i.e., TCP/IP) to route, queue, and deliver messages. We implement a software bus called the MULTIBUS that relies on a separate process only for routing and uses a reliable IP multicasting protocol for delivery of messages. The use of multicasting means that interconnections are independent of IP machine addresses. This approach allows reconfiguration of bus participants during system execution without notifying other participants of new IP addresses. The use of IP multicasting also permits an economy of scale in the number of participants. We describe the MULITIBUS protocol elements and show how our implementation performs better than centralized bus implementations.

  11. Fractal zone plates with variable lacunarity.

    Science.gov (United States)

    Monsoriu, Juan; Saavedra, Genaro; Furlan, Walter

    2004-09-06

    Fractal zone plates (FZPs), i.e., zone plates with fractal structure, have been recently introduced in optics. These zone plates are distinguished by the fractal focusing structure they provide along the optical axis. In this paper we study the effects on this axial response of an important descriptor of fractals: the lacunarity. It is shown that this parameter drastically affects the profile of the irradiance response along the optical axis. In spite of this fact, the axial behavior always has the self-similarity characteristics of the FZP itself.

  12. Patient Experiences of Decentralized HIV Treatment and Care in Plateau State, North Central Nigeria: A Qualitative Study

    Science.gov (United States)

    Kolawole, Grace O.; Gilbert, Hannah N.; Dadem, Nancin Y.; Genberg, Becky L.; Agbaji, Oche O.

    2017-01-01

    Background. Decentralization of care and treatment for HIV infection in Africa makes services available in local health facilities. Decentralization has been associated with improved retention and comparable or superior treatment outcomes, but patient experiences are not well understood. Methods. We conducted a qualitative study of patient experiences in decentralized HIV care in Plateau State, north central Nigeria. Five decentralized care sites in the Plateau State Decentralization Initiative were purposefully selected. Ninety-three patients and 16 providers at these sites participated in individual interviews and focus groups. Data collection activities were audio-recorded and transcribed. Transcripts were inductively content analyzed to derive descriptive categories representing patient experiences of decentralized care. Results. Patient participants in this study experienced the transition to decentralized care as a series of “trade-offs.” Advantages cited included saving time and money on travel to clinic visits, avoiding dangers on the road, and the “family-like atmosphere” found in some decentralized clinics. Disadvantages were loss of access to ancillary services, reduced opportunities for interaction with providers, and increased risk of disclosure. Participants preferred decentralized services overall. Conclusion. Difficulty and cost of travel remain a fundamental barrier to accessing HIV care outside urban centers, suggesting increased availability of community-based services will be enthusiastically received. PMID:28331636

  13. Fiscal decentralization of public mental health care and the Robert Wood Johnson Foundation program on chronic mental illness.

    Science.gov (United States)

    Frank, R G; Gaynor, M

    1994-01-01

    Organizational change for local mental health systems has been advanced as an important aspect of improving the performance of public mental health systems. Fiscal decentralization is a central element of many proposals for organizational change. We employ data from the states of Ohio and Texas to examine some of the consequences of fiscal decentralization of public mental health care. The data analysis shows that local mental health systems respond to financial incentives, even when they are modest; that fiscal decentralization leads to increased fiscal effort by localities; and that decentralization also results in greater inequality in service between poorer and wealthier localities.

  14. Intraocular lens alignment from an en face optical coherence tomography image Purkinje-like method

    Science.gov (United States)

    Sun, Mengchan; de Castro, Alberto; Ortiz, Sergio; Perez-Merino, Pablo; Birkenfeld, Judith; Marcos, Susana

    2014-06-01

    Measurement of intraocular lens (IOL) alignment implanted in patients in cataract surgery is important to understand their optical performance. We present a method to estimate tilt and decentration of IOLs based on optical coherence tomography (OCT) images. En face OCT images show Purkinje-like images that correspond to the specular reflections from the corneal and IOL surfaces. Unlike in standard Purkinje-imaging, the tomographic nature of OCT allows unequivocal association of the reflection with the corresponding surface. The locations of the Purkinje-like images are linear combinations of IOL tilt, IOL decentration, and eye rotation. The weighting coefficients depend on the individual anterior segment geometry, obtained from the same OCT datasets. The methodology was demonstrated on an artificial model eye with set amounts of lens tilt and decentration and five pseudophakic eyes. Measured tilt and decentration in the artificial eye differed by 3.7% and 0.9%, respectively, from nominal values. In patients, average IOL tilt and decentration from Purkinje were 3.30±4.68 deg and 0.16±0.16 mm, respectively, and differed on average by 0.5 deg and 0.09 mm, respectively, from direct measurements on distortion-corrected OCT images. Purkinje-based methodology from anterior segment en face OCT imaging provided, therefore, reliable measurements of IOL tilt and decentration.

  15. An Efficient Distributed Compressed Sensing Algorithm for Decentralized Sensor Network.

    Science.gov (United States)

    Liu, Jing; Huang, Kaiyu; Zhang, Guoxian

    2017-04-20

    We consider the joint sparsity Model 1 (JSM-1) in a decentralized scenario, where a number of sensors are connected through a network and there is no fusion center. A novel algorithm, named distributed compact sensing matrix pursuit (DCSMP), is proposed to exploit the computational and communication capabilities of the sensor nodes. In contrast to the conventional distributed compressed sensing algorithms adopting a random sensing matrix, the proposed algorithm focuses on the deterministic sensing matrices built directly on the real acquisition systems. The proposed DCSMP algorithm can be divided into two independent parts, the common and innovation support set estimation processes. The goal of the common support set estimation process is to obtain an estimated common support set by fusing the candidate support set information from an individual node and its neighboring nodes. In the following innovation support set estimation process, the measurement vector is projected into a subspace that is perpendicular to the subspace spanned by the columns indexed by the estimated common support set, to remove the impact of the estimated common support set. We can then search the innovation support set using an orthogonal matching pursuit (OMP) algorithm based on the projected measurement vector and projected sensing matrix. In the proposed DCSMP algorithm, the process of estimating the common component/support set is decoupled with that of estimating the innovation component/support set. Thus, the inaccurately estimated common support set will have no impact on estimating the innovation support set. It is proven that under the condition the estimated common support set contains the true common support set, the proposed algorithm can find the true innovation set correctly. Moreover, since the innovation support set estimation process is independent of the common support set estimation process, there is no requirement for the cardinality of both sets; thus, the proposed DCSMP

  16. Providing Support Services in Selected Decentral¬ized Hospital

    Directory of Open Access Journals (Sweden)

    R Hafezi

    2009-03-01

    Full Text Available "nBackground: Upon the implementation of the plans of the selected hospitals in Paragraph (C Article [88] of the Law of the Fourth Development Plan, the amount of assessment relative to the execution of each of the Paragraphs related to the direc­tives or guidelines of the mode of managing these hospitals is compulsory. The present article has made efforts to assess the imple­mentation basis of Paragraph [9] of the above-mentioned directives and a survey of conditions as to the performance of the support services in these hospitals."nMethods: This study rested on the performance of 14 supporting activities of 18 selected decentralized hospitals that took place in 2007. Data were collected from questionnaire that had 6 parts about support services and how they were done in each hospital. Then the data were analyzed with Excel software."nResults: In hospitals 35. 60 % of the activities are performed by the contractor. The materials utilized in activities are 10. 34 per­cent, equipping is 26. 48% and equipment repair is 31. 47% of the cases are secured by the contractor. Results pertaining to the survey of manpower engaged in activities show that 62. 71% of the manpower engaged has an intermediate level of educa­tion and the relative average of manpower active in such work as of functional beds can be stated as 0.64, likewise, the average satisfaction rate of the services rendered was 71%."nConclusion: A strategy leading to a decrease of incumbency and an elevation in the support service quality can bring about an increment in the quality of support services being presently rendered in hospitals which could prove effective.

  17. Competition in decentralized electricity markets: Three papers on electricity auctions

    Science.gov (United States)

    Harbord, David William Cameron

    This thesis consists of three self-contained papers on the analysis of electricity auctions written over a period of twelve years. The first paper models price competition in a decentralized wholesale market for electricity as a first-price, sealed-bid, multi-unit auction. In both the pure and mixed-strategy equilibria of the model, above marginal cost pricing and inefficient despatch of generating units occur. An alternative regulatory pricing rule is considered and it is shown that offering to supply at marginal cost can be induced as a dominant strategy for all firms. The second paper analyses strategic interaction between long-term contracts and price competition in the British electricity wholesale market, and confirms that forward contracts will tend to put downward pressure on spot market prices. A 'strategic commitment' motive for selling forward contracts is also identified: a generator may commit itself to bidding lower prices into the spot market in order to ensure that it will be despatched with its full capacity. The third paper characterizes bidding behavior and market outcomes in uniform and discriminatory electricity auctions. Uniform auctions result in higher average prices than discriminatory auctions, but the ranking in terms of productive efficiency is ambiguous. The comparative effects of other market design features, such as the number of steps in suppliers' bid functions, the duration of bids and the elasticity of demand are analyzed. The paper also clarifies some methodological issues in the analysis of electricity auctions. In particular we show that analogies with continuous share auctions are misplaced so long as firms are restricted to a finite number of bids.

  18. Financial management systems under decentralization and their effect on malaria control in Uganda.

    Science.gov (United States)

    Kivumbi, George W; Nangendo, Florence; Ndyabahika, Boniface Rutagira

    2004-01-01

    A descriptive case study with multiple sites and a single level of analysis was carried out in four purposefully selected administrative districts of Uganda to investigate the effect of financial management systems under decentralization on malaria control. Data were primarily collected from 36 interviews with district managers, staff at health units and local leaders. A review of records and documents related to decentralization at the central and district level was also used to generate data for the study. We found that a long, tedious, and bureaucratic process combined with lack of knowledge in working with new financial systems by several actors characterized financial flow under decentralization. This affected the timely use of financial resources for malaria control in that there were funds in the system that could not be accessed for use. We were also told that sometimes these funds were returned to the central government because of non-use due to difficulties in accessing them and/or stringent conditions not to divert them to other uses. Our data showed that a cocktail of bureaucratic control systems, corruption and incompetence make the financial management system under decentralization counter-productive for malaria control. The main conclusion is that good governance through appropriate and efficient financial management systems is very important for effective malaria control under decentralization.

  19. DISCOURSE ANALYSIS OF DECENTRALIZATION POLICY MAKING PROCESS OF PROTECTED FOREST MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Sulistya Ekawati

    2013-10-01

    Full Text Available ”Decentralization of protected forest management from central to district government has not yet been implemented effectively. This effectiveness depends on many factors that include policy contents and political process or discourse in the policy making process. This study aimsto: 1 analyze the discourse in policy making process of decentralization in the management of protected forests, 2 analyze the actors/networks and their interests and 3 find out policy space for future policy reform. Both quantitative and qualitative approaches were used in the study. The results show that there are three discourses in the policy-making process of decentralized management of protected forests, namely: i democratic discourse (with story line of externality and accountability, supported by an association forum of Indonesian district government and  decentralization experts; ii economic discourse (with story line of efficiency, supported by businessmen, Association of Indonesian Provincial Government and World Bank; and iii democratic and economic discourses. The House of Representatives (DPR and Ministry of Home Affairs have authorities and capacities to integrate two discourses. Redefining of externality and interdependency can be used as narratives of new policies to improve the policy of decentralized protected forest management.

  20. Centralization and decentralization reform in school education in Nepal: Tracing the swing of the pendulum

    Directory of Open Access Journals (Sweden)

    Peshal Khanal

    2013-03-01

    Full Text Available This article revisits the school policies in Nepal focusing on the dynamics of centralization and decentralization of school management. It is argued that the policies in a large part of the country’s history remained under the strong influence of national politics and domestic agendas, but after 1990, the government’s commitment to the global campaign of universal primary education and its overreliance on the donor-driven agenda have combined to exert an ‘external’ influence on the school policy. The rise and fall of a democratic polity in different historical periods led to a swing in school policy from centralization to decentralization. This article concludes that the current school decentralization reform has been a result of confluence of three forces – historical, democratic and international. As the country now is embarking on a large-scale political reform – a federal constitution and many ethnic and political groups are lobbying for their own agendas of power sharing, the school decentralization policy is likely to be further affected by the outcomes of this macro-political process. Based on the reflection of centralization and decentralization of school management at various historical times, this article suggests for a bottom-up process in the making of public policy.

  1. Decentralized harmonic active vibration control of a flexible plate using piezoelectric actuator-sensor pairs.

    Science.gov (United States)

    Baudry, Matthieu; Micheau, Philippe; Berry, Alain

    2006-01-01

    We have investigated decentralized active control of periodic panel vibration using multiple pairs combining PZT actuators and PVDF sensors distributed on the panel. By contrast with centralized MIMO controllers used to actively control the vibrations or the sound radiation of extended structures, decentralized control using independent local control loops only requires identification of the diagonal terms in the plant matrix. However, it is difficult to a priori predict the global stability of such decentralized control. In this study, the general situation of noncollocated actuator-sensor pairs was considered. Frequency domain gradient and Newton-Raphson adaptation of decentralized control were analyzed, both in terms of performance and stability conditions. The stability conditions are especially derived in terms of the adaptation coefficient and a control effort weighting coefficient. Simulations and experimental results are presented in the case of a simply supported panel with four PZT-PVDF pairs distributed on it. Decentralized vibration control is shown to be highly dependent on the frequency, but can be as effective as a fully centralized control even when the plant matrix is not diagonal-dominant or is not strictly positive real (not dissipative).

  2. The Impact of Decentralization on Large Scale Irrigation: Evidence from the Philippines

    Directory of Open Access Journals (Sweden)

    Eduardo K. Araral, Jr.

    2011-06-01

    Full Text Available Decentralization has often been prescribed as an institutional panacea for a wide range of problems facing developing countries. This study investigates the impacts of decentralization on the ability of individuals to solve collective action problems in a large-scale common pool resource. Using econometric analyses of a data set from the largest (83,000 hectares [ha] irrigation system in the Philippines, the study finds that decentralized subsystems are more likely to solve collective action problems such as free-riding, conflict resolution and rule enforcement. These findings are consistent with the theoretical and empirical literature but they highlight the importance of credible enforcement. These preliminary findings offer insights for the design of institutions for collective action in situations of large-scale collective action.

  3. Agent-based Decentralization of Applications in Distributed Smart Grid Systems

    DEFF Research Database (Denmark)

    Kienesberger, Georg; Xypolytou, Evangelia; Marchgraber, Jurgen

    2015-01-01

    dezentralized concepts in order to adapt to the distributed nature of smart grids. Multi-agent systems (MAS) are a very promising approach for designing distributed, decentralized systems, naturally also in the field of smart grids. This work introduces the notion of decentralized multi-agent-based control......Smart grid technology promises to prepare today’s power systems for the challenges of the future by extensive integration of information and communication technology (ICT). One key aspect is the control paradigm which will have to be shifted from completely centralized control systems to more...... systems (DMACS) and aims to give an overview on the different requirements and challenges on the way from current centralized control systems to DMACS. Therefore, different ICT scenarios and MAS topologies are employed to discuss the decentralization of three exemplary smart grid applications: voltage...

  4. MODAL SYNTHESIS METHOD FOR NORM COMPUTATION OF H∞ DECENTRALIZED CONTROL SYSTEMS (Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    ZHONG Wan-xie(钟万勰); WU Zhi-gang(吴志刚); GAO Qiang(高强); A.Y.T.Leung(梁以德); F.W.Williams

    2004-01-01

    When using H ∞ techniques to design decentralized controllers for large systems,the whole system is divided into subsystems, which are analysed using H∞ control theory before being recombined. An analogy was established with substructural analysis in structural mechanics, in which H ∞ decentralized control theory corresponds to substructural modal synthesis theory so that the optimal H ∞ norm of the whole system corresponds to the fundamental vibration frequency of the whole structure. Hence, modal synthesis methodology and the extended Wittrick-Williams algorithm were transplanted from structural mechanics to compute the optimal H∞ norm of the control system. The orthogonality and the expansion theorem of eigenfunctions of the subsystems H∞ control are presented in part (Ⅰ)of the paper. The modal synthesis method for computation of the optimal H ∞ norm of decentralized control systems and numerical examples are presented in part (Ⅱ).

  5. MODAL SYNTHESIS METHOD FOR NORM COMPUTATION OF H ∞ DECENTRALIZED CONTROL SYSTEMS ( Ⅰ )

    Institute of Scientific and Technical Information of China (English)

    ZHONG Wan-xie(钟万勰); WU Zhi-gang(吴志刚); GAO Qiang(高强); A.Y.T.Leung(梁以德); F.W.Williams

    2004-01-01

    When using H ∞ techniques to design decentralized controllers for large systems,the whole system is divided into subsystems, which are analysed using H ∞ control theory before being recombined. An analogy was established with substructural analysis in structural mechanics, in which H∞ decentralized control theory corresponds to substructural modal synthesis theory so that the optimal H∞ norm of the whole system corresponds to the fundamental vibration frequency of the whole structure. Hence, modal synthesis methodology and the extended Wittrick-Williams algorithm were transplanted from structural mechanics to compute the optimal H ∞ norm of the control system. The orthogonality and the expansion theorem of eigenfunctions of the subsystems H∞ control are presented in part ( Ⅰ ) of the paper. The modal synthesis method for computation of the optimal H∞ norm of decentralized control systems and numerical examples are presented in part ( Ⅱ ).

  6. A Supply Chain Architecture Based on Multi-agent Systems to Support Decentralized Collaborative Processes

    Science.gov (United States)

    Hernández, Jorge E.; Poler, Raúl; Mula, Josefa

    In a supply chain management context, the enterprise architecture concept to efficiently support the collaborative processes among the supply chain members involved has been evolving. Each supply chain has an organizational structure that describes the hierarchical relationships among its members, ranging from centralized to decentralized organizations. From a decentralized perspective, each supply chain member is able to identify collaborative and non collaborative partners and the kind of information to be exchanged to support negotiation processes. The same concepts of organizational structure and negotiation rules can be applied to a multi-agent system. This paper proposes a novel supply chain architecture to support decentralized collaborative processes in supply chains by considering a multi-agent-based system modeling approach.

  7. Experimental Verification of Fully Decentralized Control Inspired by Plasmodium of True Slime Mold

    Science.gov (United States)

    Umedachi, Takuya; Takeda, Koichi; Nakagaki, Toshiyuki; Kobayashi, Ryo; Ishiguro, Akio

    This paper presents a fully decentralized control inspired by plasmodium of true slime mold and its validity using a soft-bodied amoeboid robot. The notable features of this paper are twofold: (1) the robot has truly soft and deformable body stemming from real-time tunable springs and a balloon, the former is utilized as an outer skin of the body and the latter serves as protoplasm; and (2) a fully decentralized control using coupled oscillators with completely local sensory feedback mechanism is realized by exploiting the long-distance physical interaction between the body parts induced by the law of conservation of protoplasmic mass. Experimental results show that this robot exhibits truly supple locomotion without relying on any hierarchical structure. The results obtained are expected to shed new light on design scheme for autonomous decentralized control system.

  8. Resource allocation and budgetary mechanisms for decentralized health systems: experiences from Balochistan, Pakistan.

    Science.gov (United States)

    Green, A; Ali, B; Naeem, A; Ross, D

    2000-01-01

    This paper identifies key political and technical issues involved in the development of an appropriate resource allocation and budgetary system for the public health sector, using experience gained in the Province of Balochistan, Pakistan. The resource allocation and budgetary system is a critical, yet often neglected, component of any decentralization policy. Current systems are often based on historical incrementalism that is neither efficient nor equitable. This article describes technical work carried out in Balochistan to develop a system of resource allocation and budgeting that is needs-based, in line with policies of decentralization, and implementable within existing technical constraints. However, the development of technical systems, while necessary, is not a sufficient condition for the implementation of a resource allocation and decentralized budgeting system. This is illustrated by analysing the constraints that have been encountered in the development of such a system in Balochistan.

  9. Fiscal Decentralization and Disparity of Access to Primary Education in Indonesia

    Directory of Open Access Journals (Sweden)

    Shinta Doriza

    2013-12-01

    Full Text Available In education, one crusial issue of development is the disparity of primary education access. Using 440 regions database from 2005-2009, this study is aim to analize the impact of fiscal decentralization in reducing the enrolement of primary education in Indonesia. Three factors were included, i.e fiscal decentralization, socioeconomic factors and regional characteristics. The result of panel data estimation using fixed-effect approach on this study is that DAK for Education, DAK Non Education, and PAD have significant impact in reducing education acess disparity along with poverty and regional characteristic such as Java-non Java regions. For education level, another variable was also found significant including education of the society and regional characteristic such as proliferated-non proliferated regions. In general there is a facts and proves that fiscal decentralization improve education access equality, but several effort need to done to optimalize the equalization of primary education access in Indonesia.

  10. Decentralized Robust Adaptive Output Feedback Stabilization for Interconnected Nonlinear Systems with Uncertainties

    Directory of Open Access Journals (Sweden)

    Qiang Yang

    2016-01-01

    Full Text Available Based on adaptive nonlinear damping, a novel decentralized robust adaptive output feedback stabilization comprising a decentralized robust adaptive output feedback controller and a decentralized robust adaptive observer is proposed for a large-scale interconnected nonlinear system with general uncertainties, such as unknown nonlinear parameters, bounded disturbances, unknown nonlinearities, unmodeled dynamics, and unknown interconnections, which are nonlinear function of not only states and outputs but also unmodeled dynamics coming from other subsystems. In each subsystem, the proposed stabilization only has two adaptive parameters, and it is not needed to generate an additional dynamic signal or estimate the unknown parameters. Under certain assumptions, the proposed scheme guarantees that all the dynamic signals in the interconnected nonlinear system are bounded. Furthermore, the system states and estimate errors can approach arbitrarily small values by choosing the design parameters appropriately large. Finally, simulation results illustrated the effectiveness of the proposed scheme.

  11. Agent-based Decentralization of Applications in Distributed Smart Grid Systems

    DEFF Research Database (Denmark)

    Kienesberger, Georg; Xypolytou, Evangelia; Marchgraber, Jurgen

    2015-01-01

    Smart grid technology promises to prepare today’s power systems for the challenges of the future by extensive integration of information and communication technology (ICT). One key aspect is the control paradigm which will have to be shifted from completely centralized control systems to more...... dezentralized concepts in order to adapt to the distributed nature of smart grids. Multi-agent systems (MAS) are a very promising approach for designing distributed, decentralized systems, naturally also in the field of smart grids. This work introduces the notion of decentralized multi-agent-based control...... systems (DMACS) and aims to give an overview on the different requirements and challenges on the way from current centralized control systems to DMACS. Therefore, different ICT scenarios and MAS topologies are employed to discuss the decentralization of three exemplary smart grid applications: voltage...

  12. The Role of Delay and Connectivity in Throughput Reduction of Cooperative Decentralized Wireless Networks

    Directory of Open Access Journals (Sweden)

    Ahmed Alkhayyat

    2015-01-01

    Full Text Available We proposed a multiple relay selection protocol for decentralized wireless networks. The proposed relays selection protocol aims to address three issues: (1 selecting relays within the coverage area of the source and destination to ensure that the relays are positioned one hop away from the destination, (2 ensuring that the best node (best relays with less distance and attenuation from the destination access the channel first, and (3 ensuring that the proposed relays selection is collision-free. Our analysis also considers three important characteristics of decentralized wireless networks that are directly affected by cooperation: delay, connectivity, and throughput. The main goal of this paper is to demonstrate that improving connectivity and increasing number of relays reduce the throughput of cooperative decentralized wireless networks; consequently, a trade-off equation has been derived.

  13. Decentralized Control of Unmanned Aerial Robots for Wireless Airborne Communication Networks

    Directory of Open Access Journals (Sweden)

    Deok-Jin Lee

    2010-09-01

    Full Text Available This paper presents a cooperative control strategy for a team of aerial robotic vehicles to establish wireless airborne communication networks between distributed heterogeneous vehicles. Each aerial robot serves as a flying mobile sensor performing a reconfigurable communication relay node which enabls communication networks with static or slow-moving nodes on gorund or ocean. For distributed optimal deployment of the aerial vehicles for communication networks, an adaptive hill-climbing type decentralized control algorithm is developed to seek out local extremum for optimal localization of the vehicles. The sensor networks estabilished by the decentralized cooperative control approach can adopt its configuraiton in response to signal strength as the function of the relative distance between the autonomous aerial robots and distributed sensor nodes in the sensed environment. Simulation studies are conducted to evaluate the effectiveness of the proposed decentralized cooperative control technique for robust communication networks.

  14. A Feasibility Analysis Methodology for Decentralized Wastewater Systems - Energy-Efficiency and Cost.

    Science.gov (United States)

    Naik, Kartiki S; Stenstrom, Michael K

    2016-03-01

    Centralized wastewater treatment, widely practiced in developed areas, involves transporting wastewater from large urban areas to a large capacity plant using a single network of sewers, whereas decentralization is the concept of wastewater collection, treatment and reuse at or near its point of generation. Smaller decentralized plants can achieve extensive reclamation and wastewater management with energy-efficient reclaimed water pumping, modularized expansion and lower capital investment. We devised a methodology to preliminarily assess these alternatives using local constraints and conducted a feasibility analysis for each option. It addressed various scenarios using the pump-back energy consumption, sewer and treatment plant construction and capacity expansion cost. We demonstrated this methodology by applying it to the Hollywood vicinity (California). In this study, the decentralized configuration was more economical and energy-efficient than the centralized system. The pump-back energy consumption was about 50% of the aeration energy consumption for the centralized option.

  15. Decentralized Delay Optimal Control for Interference Networks with Limited Renewable Energy Storage

    CERN Document Server

    Huang, Huang

    2012-01-01

    In this paper, we consider delay minimization for interference networks with renewable energy source, where the transmission power of a node comes from both the conventional utility power (AC power) and the renewable energy source. We assume the transmission power of each node is a function of the local channel state, local data queue state and local energy queue state only. In turn, we consider two delay optimization formulations, namely the decentralized partially observable Markov decision process (DEC-POMDP) and Non-cooperative partially observable stochastic game (POSG). In DEC-POMDP formulation, we derive a decentralized online learning algorithm to determine the control actions and Lagrangian multipliers (LMs) simultaneously, based on the policy gradient approach. Under some mild technical conditions, the proposed decentralized policy gradient algorithm converges almost surely to a local optimal solution. On the other hand, in the non-cooperative POSG formulation, the transmitter nodes are non-cooperat...

  16. Impact of Fiscal Decentralization on Non-Oil Economic Growth in a ResourceRich Economy

    Directory of Open Access Journals (Sweden)

    Fakhri HASANOV

    2016-05-01

    Full Text Available The paper investigates effects of fiscal decentralization on non-oil sector development in case of Azerbaijan for the quarterly period of 2002 through 2013. Results obtained from Autoregressive Distributed Lag Bounds Testing approach show that share of local expenditures and revenues in total, measures of fiscal decentralization, have negative impact on non-oil GDP. This finding is consistent with other studies outcomes and can be considered adequate for the Azerbaijani economy due to the number of institutional constraints. The results of the research would provide a good insight for policy makers in implementing economic reforms to develop institutional aspects of decentralization and thus make it supportive for non-oil economic growth

  17. A Decentralized Eigenvalue Computation Method for Spectrum Sensing Based on Average Consensus

    Science.gov (United States)

    Mohammadi, Jafar; Limmer, Steffen; Stańczak, Sławomir

    2016-07-01

    This paper considers eigenvalue estimation for the decentralized inference problem for spectrum sensing. We propose a decentralized eigenvalue computation algorithm based on the power method, which is referred to as generalized power method GPM; it is capable of estimating the eigenvalues of a given covariance matrix under certain conditions. Furthermore, we have developed a decentralized implementation of GPM by splitting the iterative operations into local and global computation tasks. The global tasks require data exchange to be performed among the nodes. For this task, we apply an average consensus algorithm to efficiently perform the global computations. As a special case, we consider a structured graph that is a tree with clusters of nodes at its leaves. For an accelerated distributed implementation, we propose to use computation over multiple access channel (CoMAC) as a building block of the algorithm. Numerical simulations are provided to illustrate the performance of the two algorithms.

  18. Zone refining of cadmium and related characterization

    Indian Academy of Sciences (India)

    N R Munirathnam; D S Prasad; Ch Sudheer; J V Rao; T L Prakash

    2005-06-01

    We present the zone refining results of cadmium using horizontal resistive zone refiner under constant flow of moisture free hydrogen gas. The boron impurity in cadmium can be avoided using quartz (GE 214 grade) boat in lieu of high pure graphite boat. The analytical results using inductively coupled plasma optical emission spectrometry (ICPOES) show that majority of the impurities are less than the detection limits. Comparatively, zinc is the most difficult impurity element to remove in cadmium matrix by zone refining.

  19. Growth of YbFe2O4 single crystals exhibiting long-range charge order via the optical floating zone method

    Science.gov (United States)

    Williamson, H. L.; Mueller, T.; Angst, M.; Balakrishnan, G.

    2017-10-01

    We report the growth of YbFe2O4 single crystals via the floating zone technique, in four different oxygen partial pressures ranging from CO:CO2 = 1:5 to 1:2.5, for a cross comparison of stoichiometry effects. We obtained highly stoichiometric single crystals with sharp magnetic transitions as well as off-stoichiometric samples with smeared transitions. We also provide for the first time clear evidence of 3D long-range charge order correlations at room temperature in YbFe2O4 through high energy X-ray diffraction, identical to the analogous LuFe2O4. The correlation length obtained for YbFe2O4 in the c → direction is at least a factor of 5 larger than that observed in LuFe2O4.

  20. Optical, scintillation properties and defect study of Gd2Si2O7:Ce single crystal grown by floating zone method

    Science.gov (United States)

    Feng, He; Xu, Wusheng; Ren, Guohao; Yang, Qiuhong; Xie, Jianjun; Xu, Jun; Xu, Jiayue

    2013-02-01

    Single crystal of Gd2Si2O7:Ce (GPS) presenting attractive scintillation performance was grown by the floating zone method. The vacuum ultra-violet (VUV) excitation and emission, ultra-violet (UV) excitation and emission spectra and fluorescent decay time at 77 K and RT were measured and discussed. Relative energy levels of 5d sublevels of Ce3+ in GPS:Ce are detected by the VUV excitation spectrum. The UV emission curve of GPS:1%Ce peaks around 382 nm at 77 K and moves towards longer wavelength direction as temperature increases. Thermally stimulated luminescence (TSL) was employed to investigate the defects in GPS:1%Ce. Energy depths of two traps detected in GPS:1%Ce are 0.64 and 1.00 eV.

  1. Crystal growth and optical properties of Ce:(La,Gd)2Ge2O7 grown by the floating zone method

    Science.gov (United States)

    Kurosawa, Shunsuke; Shishido, Toetsu; Sugawara, Takamasa; Yubuta, Kunio; Jan, Pejchal; Suzuki, Akira; Yokota, Yuui; Shoji, Yasuhiro; Kamada, Kei; Yoshikawa, Akira

    2014-05-01

    Some pyrosilicate scintillators such as Ce:Gd2Si2O7 and Ce:Lu2Si2O7 have a good light output, and especially Ce:(Gd,La)2Si2O7 has an excellent light output of over 36,000 ph/MeV. In order to search novel scintilators, we have developed a pyrogermanate-based scintillation material (Ce0.01,Gd0.90,La0.09)2Ge2O7 using the floating zone method. Although the light output was decreased due to quenching, 5d-4f transition of Ce3+ was observed around 480 nm in photo- and radio-luminescence spectra. This emission wavelength was longer than that of (Ce0.01,Gd0.90,La0.09)2Si2O7 with an emission wavelength of 390 nm.

  2. A Novel Offset Fresnel Zone Plate Antenna

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel offset Fresnel Zone Plate reflector Antenna (FZPA) is proposed, the phase correcting zone of this FZPA is elliptic. Based on Physical Optics Method, the focusing characteristics of the reflector are analyzed. The comparison of this new FZPA with the circular FZPA and Mawzones FZPA is made.

  3. Final Report of the "advisory Committee on Decentralization, Submitted to the Board of Education of the City of New York.

    Science.gov (United States)

    Advisory Committee on Decentralization, New York, NY.

    This report of the Advisory Committee on Decentralization examines the status of school decentralization in New York City, particularly the progress of three demonstration projects, IS 201 in East Harlem, Two-Bridges in the Lower East Side, and JHS 271 and IS 55 in the Ocean Hill-Brownsville section of Brooklyn. Because it is felt that the degree…

  4. Decentralization for High-Quality Education: Elements and Issues of Design. RTI Research Report Series. Occasional Paper

    Science.gov (United States)

    Healey, F. Henry, III; Crouch, Luis

    2012-01-01

    The impact of education decentralization on high-quality education has been mixed at best. This can be attributed to a variety of factors including decentralization itself, ineffectual implementation, political-economic friction, and poor design. This paper focuses largely on the issue of design, contending that if governments or donors aim to…

  5. Control of current inverters in decentral power systems as active filters; Regelung von Netzstromrichtern in dezentralen Energiesystemen als aktive Filter

    Energy Technology Data Exchange (ETDEWEB)

    Merfert, Igor; Lindemann, Andreas [Magdeburg Univ. (Germany). Lehrstuhl fuer Leistungselektronik

    2007-07-01

    Besides their main task, decentralized power generators can combine electric power generation with system services if the inverter has current capability to spare. This paper deals with the system services, power quality improvement and a reactive power compensation, in a fuel cell based decentralized electrical power generator. A control strategy and a practical realization are introduced. (orig.)

  6. A study on the health evaluation in spot welded zone by using optical pulse and lock-in phase infrared thermography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Sang; Choi, Mang Yog; Kwon, Koo Ahn; Park, Jeong Hak [Safety Measurement Center, Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Kim, Ki Tae [School of Mechanical and Automotive Engineering, Kongju National University, Kongju (Korea, Republic of); Lee, Bo Young [School of Aerospace and Mechanical Engineering, Korea Aerospace University, Goyang (Korea, Republic of)

    2013-08-15

    The non-destructive testing using infrared thermography is extended to a variety of industries and non-destructive testing of welds using infrared thermography is also in progress in various ways. Currently, a non-destructive testing of electrical resistance spot welds which is mainly used is Radiography Testing. This study detected area of spot welds nugget using optical-infrared thermography. In the results, it is possible for detecting defects of nugget in a short period of time using pulse-infrared thermography.

  7. Decentralized control of continuous time interconnected stochastic systems based on successive pole assignment

    Science.gov (United States)

    Ray, G.; Yadaiah, N.

    1992-12-01

    A simple decentralized Kalman filter based regulator problem is proposed to achieve sub-system closed-loop eigenvalues at desired locations and subsequently to minimize the local quadratic performance index of each decoupled sub-system. The proposed scheme reduces the information exchange, telemetry and instrumentation costs and computational burden compared to a centralized control scheme. A consideration of the stability of the global decentralized control system is included. The effectiveness of the proposed control scheme is tested by considering a load-frequency control problem of a two-area power system.

  8. Sourcing and pricing strategies for two retailers in a decentralized supply chain system under supply disruption

    Directory of Open Access Journals (Sweden)

    M.A. Azarmehr

    2012-01-01

    Full Text Available This paper presents the decentralized supply chain with two suppliers and two competing retailers. It also investigates the sourcing and pricing strategies of two retailers in a decentralized supply chain system under a supply disruption environment. These retailers face their individual stochastic demand markets; however, they compete with each other through a two-stage price and service operation. The interactive dynamics among retailers is characterized, including the existence and uniqueness of the Nash Equilibrium in service and price games demonstrated.

  9. Decentralized Adaptive Control of Systems with Uncertain Interconnections, Plant-Model Mismatch and Actuator Failures

    Science.gov (United States)

    Patre, Parag; Joshi, Suresh M.

    2011-01-01

    Decentralized adaptive control is considered for systems consisting of multiple interconnected subsystems. It is assumed that each subsystem s parameters are uncertain and the interconnection parameters are not known. In addition, mismatch can exist between each subsystem and its reference model. A strictly decentralized adaptive control scheme is developed, wherein each subsystem has access only to its own state but has the knowledge of all reference model states. The mismatch is estimated online for each subsystem and the mismatch estimates are used to adaptively modify the corresponding reference models. The adaptive control scheme is extended to the case with actuator failures in addition to mismatch.

  10. Photovoltaic energy for rural decentralized electrification; L`energie photovoltaique pour l`electrification rurale decentralisee

    Energy Technology Data Exchange (ETDEWEB)

    Diet, A.; Schmitt, A.; Soler, R. [Electricite de France (EDF), 92 - Clamart (France). Dept. Postes et Lignes; Marboeuf, G. [Electricite de France, 92 - Paris la Defense (France). Service International Distribution; Klein, B.; Pages, A. [Electricite de France (EDF), 75 - Paris (France). Direction International

    1999-04-01

    What is at stake for the new coming century is to supply electricity and modernity to two billion of people in the rural areas of developing countries. To reach this goal it is necessary to organize the electrification of these countries. It means building electrification master plans and creating decentralized Services Companies. It is also necessary to ensure the quality of electrification systems using renewable energies. It is what the DRE Specifications written by EDF, ADEME and the French photovoltaic industry, are designed for. If these conditions are fulfilled, renewable energies seem to have a promising future in rural decentralized electrification. (authors)

  11. Decentralized Control for a Class of Similar Composite Systems with Interconnections with Unsatisfying Interconnection Condition

    Institute of Scientific and Technical Information of China (English)

    WANG Zheng; LI Zhong-hai; ZHANG Si-ying; HOU Xue-zhang

    2001-01-01

    In this paper, a class of similar composite systems is discussed, whose interconnections areasymmetrical and mismatched. The interconnection condition is proposed. Based on it, the interconnectionsare divided into two parts. One satisfies the interconnection condition, by means of the two--step method,the decentralized controllers are designed. The other does not satisfy the interconnection condition, but thisis offsetted by good quality of the system itself. Based on these, a sufficient condition is given by some linearmatrix inequalities, which makes the studied systems quadratic stabile via linear decentralized controllers bymaking use of the information of interconnections better.

  12. Decentralized PD Control for Non-uniform Motion of a Hamiltonian Hybrid System

    Institute of Scientific and Technical Information of China (English)

    Mingcong Deng; Hongnian Yu; Akira Inoue

    2008-01-01

    In this paper, a decentralized proportional-derivative (PD) controller design for non-uniform motion of a Hamiltonian hybrid system is considered. A Hamiltonian hybrid system with the capability of producing a non-uniform motion is developed. The structural properties of the system are investigated by means of the theory of Hamiltonian systems. A relationship between the parameters of the system and the parameters of the proposed decentralized PD controller is shown to ensure local stability and tracking performance. Simulation results are included to show the obtained non-uniform motion.

  13. Synchronization analysis of coloured delayed networks under decentralized pinning intermittent control

    Indian Academy of Sciences (India)

    JIANG SHENGQIN; LU XIAOBO

    2016-06-01

    This paper investigates synchronization of coloured delayed networks under decentralized pinning intermittent control. To begin with, the time delays are taken into account in the coloured networks. In addition, we propose a decentralized pinning intermittent control for coloured delayed networks, which is different from that most of pinning intermittent controls are only appliedto the nodes from 1 to l or centralized nodes. Moreover, sufficient conditions are derived to guarantee the synchronization of coloured delayed networks based on Lyapunov stability theorem. Finally, numerical simulations are provided to verify the validity of the obtained results.

  14. Parallel Decentralized Network for the Detection of Unknown Signals Through Wireless Nakagami Fading Channels

    Science.gov (United States)

    El-Bahaie, Ebtehal H.; Al-Hussaini, Emad K.

    2010-12-01

    In this paper analytical and simulation results for the decentralized detection of unknown signals are introduced. Parallel sensor network scheme is assumed. Additive White Gaussian Noise (AWGN) and Nakagami fading are assumed in both links, that is, from the source to the decentralized local sensors and from the sensors to the fusion center. Furthermore, diversity employing Square Law Combining (SLC) or Square Law Selection (SLS) is considered at each sensor, for both independent and correlated branches. Appreciable improvements are obtained with the increase of the number of sensors and the diversity employment.

  15. Sustainable energy and social development. A decentralized and participatory approach to energy development

    Energy Technology Data Exchange (ETDEWEB)

    Karottki, R. [Forum for Energy and Development, Executive Secretary, Copenhagen (Denmark)

    1994-12-01

    Decentralized and sustainable energy development is now taking off in many corners of the world. 150,000 battery charging windmills operating among nomads in Inner Mongolia (China), hundreds of thousands family biogas plants providing energy and fertilizer for rural people in India, 1,000,000 efficient charcoal stoves manufactured and sold by small local companies in Kenya, 500 MW of wind power installed by rural cooperatives in Denmark are just a few examples. Because of the social and environmental benefits and of the possibilities for substitution of oil, such decentralized systems can be highly relevant to small island states. (au)

  16. Institutions and government efficiency: decentralized Irrigation management in China

    Directory of Open Access Journals (Sweden)

    Ying Chai

    2016-02-01

    Full Text Available In order to improve the efficiency of government spending, it is necessary for the decentralized irrigation management to gain support from local institutions. Efficient institutions take on several distinct configurations in different irrigation districts. In this research, we upgrade Tang’s (1992 framework focusing on incentives, to a framework that includes institutional incentives and coordination. Within the framework, we then classify 5 institutional variables: water pricing reform (P, government funding (F, coordination by administration (C, having formal monitors (M and self-organized management (S. This article processes the data obtained through a field survey (2009–2011 in 20 of China’s southern counties, where they implement the “Small-scale Irrigation and Water Conservancy Key Counties Construction (Key Counties Construction”, a national project supported by the central government. Next, it applies Data Envelopment Analysis (DEA to measure the efficiency of government spending and uses Qualitative Comparative Analysis (QCA to extract efficient institutional configurations. It concludes that there are generally three types of institutional configurations able to improve the efficiency of government spending, which are respectively: “government funding combined with coordination by administration”, “water pricing reform combined with self-organized management and coordination by administration or water pricing reform combined with self-organized management and government funding and formal monitors” and “self-organized management”. Among these, the second configuration is a mixed governance structure with multiple institutions coexisting, and this configuration occurs in the most efficient key counties. For that reason, it is viewed as the mainstream irrigation management approach, and we expect it to be the development trend in the future. Although Chinese irrigation policies are formalizing effective local

  17. Hot water supply in ''Smart Home''. Decentralized supply, decentralized control; Warmwasserversorgung im 'Smart Home'. Dezentral versorgen, dezentral steuern

    Energy Technology Data Exchange (ETDEWEB)

    Wiechers, Olaf

    2013-10-01

    The separation of the heating system and domestic hot water is already established in commercial and residential construction. The decentralized hot water supply offers environmental and economic benefits. In this paper it is shown that one can also do this in a detached house. [German] Die Trennung von Heizsystem und Warmwasserbereitung ist im Gewerbe- und Wohnungsbau bereits etabliert. Die dezentrale Warmwasserversorgung bietet oekologische und oekonomische Vorteile. In diesem Beitrag wird gezeigt, dass man dies auch bei einem Einfamilienhaus durchfuehren kann.

  18. Governing decentralization in health care under tough budget constraint: what can we learn from the Italian experience?

    Science.gov (United States)

    Tediosi, Fabrizio; Gabriele, Stefania; Longo, Francesco

    2009-05-01

    In many European countries, since the World War II, there has been a trend towards decentralization of health policy to lower levels of governments, while more recently there have been re-centralization processes. Whether re-centralization will be the new paradigm of European health policy or not is difficult to say. In the Italian National Health Service (SSN) decentralization raised two related questions that might be interesting for the international debate on decentralization in health care: (a) what sort of regulatory framework and institutional balances are required to govern decentralization in health care in a heterogeneous country under tough budget constraints? (b) how can it be ensured that the most advanced parts of the country remain committed to solidarity, supporting the weakest ones? To address these questions this article describes the recent trends in SSN funding and expenditure, it reviews the strategy adopted by the Italian government for governing the decentralization process and discusses the findings to draw policy conclusions. The main lessons emerging from this experience are that: (1) when the differences in administrative and policy skills, in socio-economic standards and social capital are wide, decentralization may lead to undesirable divergent evolution paths; (2) even in decentralized systems, the role of the Central government can be very important to contain health expenditure; (3) a strong governance of the Central government may help and not hinder the enforcement of decentralization; and (4) supporting the weakest Regions and maintaining inter-regional solidarity is hard but possible. In Italy, despite an increasing role of the Central government in steering the SSN, the pattern of regional decentralization of health sector decision making does not seem at risk. Nevertheless, the Italian case confirms the complexity of decentralization and re-centralization processes that sometimes can be paradoxically reinforcing each other.

  19. Prognosis of flow conditions for de-centralized seepage of rainwater from roads

    Science.gov (United States)

    Meyer, Martin; Hasan, Issa; Sallwey, Jana; Graeber, Peter-Wolfgang

    2013-04-01

    Urbanization programs that include the construction of new settlements or roads lead to an increase in surface sealing. Conventional road drainage is being carried out by a rainwater sewage system coupled with collection and detention basins. This leads to local decreases in evaporation and groundwater recharge, disturbing the natural local water balance. The increased number of climate changed induced extreme precipitation events leads to a higher risk of road floodings as a result of a failure of these systems. Furthermore, the treatment of the discharge loaded with contaminants (such as heavy metals and MTBE) is resolved neither ecologically nor technologically. By using a natural, effective and sustainable evaporation and drainage strategy it is possible to reduce the probability of road floodings, to restore the natural local water balance and to establish ecologically and economically more beneficial rainwater drainage. By using PCSiWaPro®, a simulation tool for unsaturated soil zone processes developed at the Institute of Waste Management and the Technical University of Dresden, the effects of different atmospheric, hydrological and hydrogeological parameters and system conditions on the subsurface drainage flow conditions in the vicinity of a typical German highway road were studied. Special attention was given to the influence of extreme precipitation events on the drainage time at differently tilted parts of the surface, on surface drainages from lateral noise-protection barriers and on the probability of road surface underwashing. Differently constructed upper soil stratifications were tested for their ability to quickly drain water into the ground, which, besides the reduced risk of road flooding, also influence the duration time for the drainage water in each soil layer. Individual rainwater infiltration rates were applied for different regions of the model. The behaviours of three different types of soil (coarse sand, slightly silty sand and medium

  20. Bidirectional decentralized energy management in the low voltage grid based on centralized and decentralized informations; Bidirektionales dezentrales Energiemanagement im Niederspannungsnetz auf Basis zentraler und dezentraler Informationen

    Energy Technology Data Exchange (ETDEWEB)

    Bendel, C.; Nestle, D.; Ringelstein, J. [Inst. fuer Solare Energieversorgungstechnik e.V., Verein an der Univ. Kassel (Germany)

    2006-07-01

    Decentralized electrical generation units (DG units) are connected to the network in Europe with an increasing number and generation capacity. This includes renewable energy sources with fluctuating generation characteristics as well as more controllable generation from biomass and co-generation. Severe problems with grid operation are expected among experts when the share of DG without controllability exceeds approx. 20 to 25% of the total generation within the power system, so a new strategy for the integration of DG into grid operation will be required. This strategy will include energy management with controllable generators as well as controllable loads. Today, however, this potential in most cases cannot be activated due to lack of standards and missing economical incentives. In the concept presented in this work the grid connection point is extended by intelligent components to a Bidirectional Energy Management Interface (BEMI). This allows a technically efficienct design of an energy management system and avoids fundamental organizational changes to the current grid regime. The concept of decentralized decision based on information from a central control station covers the requirements of the system operators as well as the local customer. Using the same concept the management of a pool of devices, containing BEMI-equipped households as well as other decentralized resources is possible. This is expected to bring additional benefits for both system operators and local customers. Therefore an approach for upscaling the existing BEMI technology is outlined as an outlook. (orig.)

  1. Anharmonicity of Zone-Center Optical Phonons: Raman Scattering Spectra of GaSe0.5S0.5 Layered Crystal

    Science.gov (United States)

    Gasanly, N. M.; Aydinli, A.; Aydinli, A.; Kocabaş, C.; Özkan, H.

    The temperature dependencies (10-300 K) of the eight Raman-active mode frequencies and linewidths in GaSe0.5S0.5 layered crystal have been measured in the frequency range from 10 to 320 cm-1. We observed softening and broadening of the optical phonon lines with increasing temperature. Comparison of the experimental data with the theories of the shift and broadening of the interlayer and intralayer phonon lines showed that the temperature dependencies can be explained by the contributions from thermal expansion, lattice anharmonicity and crystal disorder. The purely anharmonic contribution (phonon-phonon coupling) is found to be due to three-phonon processes. It was established that the effect of crystal disorder on the broadening of phonon lines is greater for GaSe0.5S0.5 than for binary compounds GaSe and GaS.

  2. Does fiscal decentralization improve health outcomes? Evidence from infant mortality in Italy.

    Science.gov (United States)

    Cavalieri, Marina; Ferrante, Livio

    2016-09-01

    Despite financial and decision-making responsibilities having been increasingly devolved to lower levels of government worldwide, the potential impact of these reforms remains largely controversial. This paper investigates the hypothesis that a shift towards a higher degree of fiscal autonomy of sub-national governments could improve health outcomes, as measured by infant mortality rates. Italy is used as a case study since responsibilities for healthcare have been decentralized to regions, though the central government still retains a key role in ensuring all citizens uniform access to health services throughout the country. A linear fixed-effects regression model with robust standard errors is employed for a panel of 20 regions over the period 1996-2012 (340 observations in the full sample). Decentralization is proxied by two different indicators, capturing the degree of decision-making autonomy in the allocation of tax revenues and the extent to which regions rely on fiscal transfers from the central government. The results show that a higher proportion of tax revenues raised and/or controlled locally as well as a lower transfer dependency from the central government are consistently associated with lower infant mortality rates, ceteris paribus. The marginal benefit from fiscal decentralization, however, is not constant but depends on the level of regional wealth, favouring poorest regions. In terms of policy implications, this study outlines how the effectiveness of decentralization in improving health outcomes is contingent on the characteristics of the context in which the process takes place.

  3. Research Challenges: Implementing Standardized Outcome Measures in a Decentralized, Community-Based Residential Treatment Program

    Science.gov (United States)

    Butler, Linda S.; Little, Liza; Grimard, Andre R.

    2009-01-01

    With residential treatment services under pressure to produce outcome data, the process of executing research in such settings presents considerable challenges. This paper describes how a large, decentralized, community-based residential treatment program in southern and central Maine designed and implemented a research outcome process study using…

  4. Financial and economic feasibility of decentralized wastewater reuse systems in Beijing

    NARCIS (Netherlands)

    X. Liang (Xiao); M.P. van Dijk (Meine Pieter)

    2010-01-01

    textabstractMany decentralized wastewater reuse systems have been constructed in Beijing. However their performance is not as good as expected. The total amount of reclaimed water used in Beijing is much less than the designed capacity. In order to understand the reasons causing such poor performanc

  5. Decentralized water resources management in Mozambique: Challenges of implementation at the river basin level

    Science.gov (United States)

    Inguane, Ronaldo; Gallego-Ayala, Jordi; Juízo, Dinis

    In the context of integrated water resources management implementation, the decentralization of water resources management (DWRM) at the river basin level is a crucial aspect for its success. However, decentralization requires the creation of new institutions on the ground, to stimulate an environment enabling stakeholder participation and integration into the water management decision-making process. In 1991, Mozambique began restructuring its water sector toward operational decentralized water resources management. Within this context of decentralization, new legal and institutional frameworks have been created, e.g., Regional Water Administrations (RWAs) and River Basin Committees. This paper identifies and analyzes the key institutional challenges and opportunities of DWRM implementation in Mozambique. The paper uses a critical social science research methodology for in-depth analysis of the roots of the constraining factors for the implementation of DWRM. The results obtained suggest that RWAs should be designed considering the specific geographic and infrastructural conditions of their jurisdictional areas and that priorities should be selected in their institutional capacity building strategies that match local realities. Furthermore, the results also indicate that RWAs have enjoyed limited support from basin stakeholders, mainly in basins with less hydraulic infrastructure, in securing water availability for their users and minimizing the effect of climate variability.

  6. Standard for decentralized power supply to the public grid; Norm fuer dezentrale Netzeinspeisung

    Energy Technology Data Exchange (ETDEWEB)

    Seltmann, T. [SolarAgentur, Nuernberg (Germany); Kremer, P. [Siemens AG, Fuerth (Germany); Lappe, U. [Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Koeln (Germany). Abt. Sicherheitsfragen der Elektrotechnik

    1999-08-01

    Photovoltaic energy conversion has finally been acknowledged in technical specifications. The new DIN VDE 0126 regulates decentralized power supply to the publc grid and improves protection of working staff. [German] Die photovoltaische Stromerzeugung haelt jetzt auch Einzug in technische Regelwerke. Die kuerzlich in Kraft getretene DIN VDE 0126 macht den Weg frei fuer die flaechendeckende dezentrale Netzeinspeisung. Ausserdem verbessert diese Norm den Personenschutz. (orig.)

  7. Street-Level Governments: Assessing Decentralization and Urban Services (An Evaluation of Policy Related Research).

    Science.gov (United States)

    Yin, Robert K.; Yates, Douglas

    Urban decentralization is an attempt to reorganize local services through some combination of: (1) giving service recipients or clients greater responsibility over service policies (the client dimension) and (2) increasing service resources at the level of specific, geographically defined neighborhoods (the territorial dimension). The…

  8. A Formally Verified Decentralized Key Management Architecture for Wireless Sensor Networks

    NARCIS (Netherlands)

    Law, Yee Wei; Corin, Ricardo; Etalle, Sandro; Hartel, Pieter H.; Conti, Marco; Giordano, Silvia; Gregori, Enrico; Olariu, Stephan

    2003-01-01

    We present a decentralized key management architecture for wireless sensor networks (WSNs), covering the aspects of key deployment, key refreshment and key establishment. Our architecture is based on a clear set of assumptions and guidelines. Key deployment uses minimal key storage while key refresh

  9. Decentralized reputation-based trust for assessing agent reliability under aggregate feedback

    NARCIS (Netherlands)

    T.B. Klos (Tomas); J.A. La Poutré (Han)

    2005-01-01

    htmlabstractReputation mechanisms allow agents to establish trust in other agents’ intentions and capabilities in the absence of direct interactions. In this paper, we are concerned with establishing trust on the basis of reputation information in open, decentralized systems of interdependent

  10. Decentralized reputation-based trust for assessing agent reliability under aggregate feedback

    NARCIS (Netherlands)

    T.B. Klos (Tomas); J.A. La Poutré (Han)

    2005-01-01

    htmlabstract Reputation mechanisms allow agents to establish trust in other agents’ intentions and capabilities in the absence of direct interactions. In this paper, we are concerned with establishing trust on the basis of reputation information in open, decentralized systems of interdependent

  11. Analysis of power and frequency control requirements in view of increased decentralized production and market liberalization

    NARCIS (Netherlands)

    Roffel, B; de Boer, WW

    2003-01-01

    This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed. Fi

  12. School Decentralization and Community Control: Policy in Search of a Research Agenda.

    Science.gov (United States)

    Spivak, Harriet

    The relationship between research and educational policy in the areas of school system decentralization and community control is analyzed in this dissertation. The literature on decentraliztion and community control is reviewed. It is contended that existing empirical research on these subjects has not systematically tested the assumptions…

  13. Decision making under the tree: gender perspectives on decentralization reforms in service delivery in rural Tanzania

    NARCIS (Netherlands)

    Masanyiwa, Z.S.

    2014-01-01

    In recent decades, decentralization has been upheld by governments, donors and policy makers in many developing countries as a means of improving people’s participation and public services delivery. In 1996, the government of Tanzania embarked on major local government reforms reflecting the g

  14. Decision making under the tree: gender perspectives on decentralization reforms in service delivery in rural Tanzania

    NARCIS (Netherlands)

    Masanyiwa, Z.S.

    2014-01-01

    In recent decades, decentralization has been upheld by governments, donors and policy makers in many developing countries as a means of improving people’s participation and public services delivery. In 1996, the government of Tanzania embarked on major local government reforms reflecting the

  15. Decision making under the tree: gender perspectives on decentralization reforms in service delivery in rural Tanzania

    NARCIS (Netherlands)

    Masanyiwa, Z.S.

    2014-01-01

    In recent decades, decentralization has been upheld by governments, donors and policy makers in many developing countries as a means of improving people’s participation and public services delivery. In 1996, the government of Tanzania embarked on major local government reforms reflecting the g

  16. Analysis of power and frequency control requirements in view of increased decentralized production and market liberization

    NARCIS (Netherlands)

    Roffel, B.; de Boer, Wouter W.

    2003-01-01

    This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed.

  17. Analysis of power and frequency control requirements in view of increased decentralized production and market liberalization

    NARCIS (Netherlands)

    Roffel, B; de Boer, WW

    This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed.

  18. Localizing Land Governance, Strengthening the State: Decentralization and Land Tenure Security in Uganda

    NARCIS (Netherlands)

    Leeuwen, M. van

    2017-01-01

    Decentralization of land governance is expected to significantly improve land tenure security of small-scale farmers in Africa, through ensuring better protection of their assets and reducing land-related conflicts. This paper, however, cautions not to have too high expectations of transferring

  19. From State Control to Governance: Decentralization and Higher Education in Guangdong, China.

    Science.gov (United States)

    Mok, Joshua Ka-Ho

    2001-01-01

    Examines how the policy of decentralization has affected the governance of universities in Guangdong, China. Focuses on the reform of the financing and management structure, the merging of universities, and joint development programs to enhance competitiveness. Asserts that the state role as a regulator has actually been strengthened. (Contains 79…

  20. Decentralized Fault Tolerant Control for a Class of Interconnected Nonlinear Systems.

    Science.gov (United States)

    Shao, Shuai; Yang, Hao; Jiang, Bin; Cheng, Shuyao

    2016-11-22

    This paper proposes a decentralized fault tolerant methodology for a class of interconnected nonlinear systems. The key novelty of our proposed method is that fault tolerant control can be achieved without necessarily exchanging the state information between the subsystems and the couplings' effect can be dealt with utilizing the cyclic-small-gain methodology. Simulation results demonstrate effectively the validity of our proposed approach.

  1. Decentralized Single-beacon Acoustic Navigation: Combined Communication and Navigation for Underwater Vehicles

    Science.gov (United States)

    2010-06-01

    OMB control number. 1. REPORT DATE JUN 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Decentralized...Fly Subsea Mission Corrections . . . . . . . . . . . . . . . 49 3.5 Chapter Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 4...System Models 52 4.1 State Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4.2 Vehicle Process Model

  2. Integration of capacity, pricing, and lead-time decisions in a decentralized supply chain

    NARCIS (Netherlands)

    Zhu, Stuart X.

    We consider a decentralized supply chain consisting of a supplier and a retailer facing price- and lead-time-sensitive demand. The decision process is modelled by a Stackelberg game where the supplier, as a leader, determines the capacity and the wholesale price, and the retailer, as a follower,

  3. Analysis of power and frequency control requirements in view of increased decentralized production and market liberalization

    NARCIS (Netherlands)

    Roffel, B; de Boer, WW

    2003-01-01

    This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed. Fi

  4. Near Optimal Decentralized H-infinity Control: Bounded vs. Unbounded Controller Order

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.H.

    1997-01-01

    It is shown that for a class of decentralized control problems there does not exist a sequence of controllers of bounded order which obtains near optimal control. Neither does there exist an infinite dimensional optimal controller. Using the insight of the line of proof of these results, a heuris...

  5. Membrane-based air conditioning. Decentral desiccant cooling; Membranbasierte Raumklimatisierung. Dezentrale sorptionsgestuetzte Klimatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbaum, Hannes [Institut fuer Luft- und Kaeltetechnik gGmbH, Dresden (Germany)

    2012-04-15

    Semipermeable membranes have a considerable potential use in air conditioning systems due to their properties. As water resistant but water vapor permeable functional separation layers, they allow desiccant air-conditioning processes in decentral air conditioning systems and a condensate-free air dehumidification at cooling ceiling elements. (orig.)

  6. Integration of capacity, pricing, and lead-time decisions in a decentralized supply chain

    NARCIS (Netherlands)

    Zhu, Stuart X.

    2015-01-01

    We consider a decentralized supply chain consisting of a supplier and a retailer facing price- and lead-time-sensitive demand. The decision process is modelled by a Stackelberg game where the supplier, as a leader, determines the capacity and the wholesale price, and the retailer, as a follower, det

  7. Decentralization, participation and deliberation in water governance: a case study of the implications for Guarulhos, Brazil

    NARCIS (Netherlands)

    F. van den Brandeler; M. Hordijk; K. von Schönfeld; J. Sydenstricker-Neto

    2014-01-01

    After the return to democracy in the late 1980s, Brazil developed a new system of water governance with a decentralization of responsibilities and the formation of participatory, deliberative institutions that characterized the governance reforms in general. Tripartite "water basin committees", with

  8. Overview on Decentralized Establishment of Consistent Multi-lateral Collaborations based on Asynchronous Communication

    NARCIS (Netherlands)

    Wombacher, Andreas; Fankhauser, Peter; Aberer, Karl; Cheung, W.; Hsu, J.

    2005-01-01

    Service oriented architectures facilitate loosely coupled collaborations, which are established in a decentralized way. One challenge for such collaborations is to guarantee consistency, that is, fulfillment of all constraints of individual services and deadlock-freeness. This paper introduces a dec

  9. Challenges to the implementation of health sector decentralization in Tanzania: experiences from Kongwa district council

    Science.gov (United States)

    Frumence, Gasto; Nyamhanga, Tumaini; Mwangu, Mughwira; Hurtig, Anna-Karin

    2013-01-01

    Background During the 1990s, the government of Tanzania introduced the decentralization by devolution (D by D) approach involving the transfer of functions, power and authority from the centre to the local government authorities (LGAs) to improve the delivery of public goods and services, including health services. Objective This article examines and documents the experiences facing the implementation of decentralization of health services from the perspective of national and district officials. Design The study adopted a qualitative approach, and data were collected using semi-structured interviews and were analysed for themes and patterns. Results The results showed several benefits of decentralization, including increased autonomy in local resource mobilization and utilization, an enhanced bottom-up planning approach, increased health workers’ accountability and reduction of bureaucratic procedures in decision making. The findings also revealed several challenges which hinder the effective functioning of decentralization. These include inadequate funding, untimely disbursement of funds from the central government, insufficient and unqualified personnel, lack of community participation in planning and political interference. Conclusion The article concludes that the central government needs to adhere to the principles that established the local authorities and grant more autonomy to them, offer special incentives to staff working in the rural areas and create the capacity for local key actors to participate effectively in the planning process. PMID:23993021

  10. China’s Development Modeli:the Costs and Benefits of the Decentralization Approach to Transition

    Institute of Scientific and Technical Information of China (English)

    张晏; 王永钦; 章元; 陈钊; 陆铭

    2007-01-01

    This article provides a coherent framework within which to understand China’s development model,as well as the successes and the failures of China’s decentralization approach to reform.The combination of political centralization and economic decentralization provide local government with enough incentives to develop local economies,in particular incentives to promote market privatisation locally.However,the relative evaluation-based incentive schemes lead to inter- regional market segmentation,increasing inter-regional development gaps and the unequal provision of certain public goods.The success of early-stage reform can be attributed to the benefits of the decentralization approach.The next stage reform should however focus on minimizing the associated costs.China’s gradualist reform can be seen as a mechanism design issue under the control of central government.Therefore,it is essential to take both the costs and benefits of the decentralization approach into account in the design of the next-stage reform package.

  11. Progress and challenges in utilization of palm oil biomass as fuel for decentralized electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Bazmi, Aqeel Ahmed [Process Systems Engineering Centre (PROSPECT), Department of Chemical Engineering, Faculty of Chemical and Natural Resources Engineering, University Technology Malaysia, Skudai 81310, Johor Bahru, JB (Malaysia); Biomass Conversion Research Center (BCRC), Department of Chemical Engineering, COMSATS Institute of Information Technology, Lahore (Pakistan); Zahedi, Gholamreza; Hashim, Haslenda [Process Systems Engineering Centre (PROSPECT), Department of Chemical Engineering, Faculty of Chemical and Natural Resources Engineering, University Technology Malaysia, Skudai 81310, Johor Bahru, JB (Malaysia)

    2011-01-15

    It has been broadly accepted worldwide that global warming, indeed, is the greatest threat of the time to the environment. Renewable energy (RE) is expected as a perfect solution to reduce global warming and to endorse sustainable development. Progressive release of greenhouse gases (GHG) from increasing energy-intensive industries has eventually caused human civilization to suffer. Realizing the exigency of reducing emissions and simultaneously catering to needs of industries, researchers foresee the RE as the perfect entrant to overcome these challenges. RE provides an effective option for the provision of energy services from the technical point of view while biomass, a major source of energy in the world until before industrialization when fossil fuels become dominant, appears an important renewable source of energy and researches have proven from time to time its viability for large-scale production. Being a widely spread source, biomass offers the execution of decentralized electricity generation gaining importance in liberalized electricity markets. The decentralized power is characterized by generation of electricity nearer to the demand centers, meeting the local energy needs. Researchers envisaged an increasing decentralization of power supply, expected to make a particular contribution to climate protection. This article investigates the progress and challenges for decentralized electricity generation by palm oil biomass according to the overall concept of sustainable development. (author)

  12. Local Government Systems and Decentralization: Evidence from Pakistan’s Devolution Plan

    Directory of Open Access Journals (Sweden)

    Muhammad Shakil Ahmad

    2013-03-01

    Full Text Available The discourse of governance and development practitioners continues to embrace community participation and community empowerment as an elementary means of building local capacity for poverty reduction, development and change at the local level. This article is a review of the decentralization initiatives of local government systems after the announcement of the devolution plan in Pakistan. It evaluates the initiatives’ participatory methods to ascertain the extent to which they have improved the process of community development at the local level. This article also measures the impact of community empowerment on the sustainability of community-driven projects implemented under the decentralization initiative through community-based organizations known as Citizen Community Boards (CCBs. Document analysis and literature review methodologies were employed to gain further insight into the decentralization phenomenon in Pakistan. The results describe human development, improvements in community empowerment and the sustainability of local projects; however, the sense of community has yet to be translated into shared benefits for rural communities. The fundamental goal of decentralization seems to be elusive because only power was transferred to the local level, whereas there is little support for community capacity building and community access to resources and the elites still control the electoral process. It is argued that community development initiatives in Pakistan require continuous support from local governments to boost local rural economies. Likewise, community-local government participatory development strategies can lead to strong local ownership and empowerment in rural communities.

  13. Decentralized Governance and Environmental Change: Local Institutional Moderation of Deforestation in Bolivia

    Science.gov (United States)

    Andersson, Krister; Gibson, Clark C.

    2007-01-01

    Dozens of countries have decentralized at least part of their natural resource policies over the last two decades. Despite the length of time that these policy experiments have been in force, there is little agreement about their effectiveness. We argue that part of this ambivalence stems from three limitations of extant studies, suggesting that…

  14. School Decentralization and Community Control: Policy in Search of a Research Agenda.

    Science.gov (United States)

    Spivak, Harriet

    The relationship between research and educational policy in the areas of school system decentralization and community control is analyzed in this dissertation. The literature on decentraliztion and community control is reviewed. It is contended that existing empirical research on these subjects has not systematically tested the assumptions…

  15. Centralization versus decentralization as a risk-return trade-off

    NARCIS (Netherlands)

    Arcuri, A.; Dari-Mattiacci, G.

    2010-01-01

    This paper characterizes the choice between centralization and decentralization as a risk‐return trade‐off and examines it in a model that integrates ideas from committee decision‐making and portfolio theories. Centralization, by pooling expertise, rarely yields erroneous decisions; however, when it

  16. Optimizing Natural Gas Networks through Dynamic Manifold Theory and a Decentralized Algorithm: Belgium Case Study

    Science.gov (United States)

    Koch, Caleb; Winfrey, Leigh

    2014-10-01

    Natural Gas is a major energy source in Europe, yet political instabilities have the potential to disrupt access and supply. Energy resilience is an increasingly essential construct and begins with transmission network design. This study proposes a new way of thinking about modelling natural gas flow. Rather than relying on classical economic models, this problem is cast into a time-dependent Hamiltonian dynamics discussion. Traditional Natural Gas constraints, including inelastic demand and maximum/minimum pipe flows, are portrayed as energy functions and built into the dynamics of each pipe flow. Doing so allows the constraints to be built into the dynamics of each pipeline. As time progresses in the model, natural gas flow rates find the minimum energy, thus the optimal gas flow rates. The most important result of this study is using dynamical principles to ensure the output of natural gas at demand nodes remains constant, which is important for country to country natural gas transmission. Another important step in this study is building the dynamics of each flow in a decentralized algorithm format. Decentralized regulation has solved congestion problems for internet data flow, traffic flow, epidemiology, and as demonstrated in this study can solve the problem of Natural Gas congestion. A mathematical description is provided for how decentralized regulation leads to globally optimized network flow. Furthermore, the dynamical principles and decentralized algorithm are applied to a case study of the Fluxys Belgium Natural Gas Network.

  17. A decentralized scalable approach to voltage control of DC islanded microgrids

    DEFF Research Database (Denmark)

    Tucci, Michele; Riverso, Stefano; Quintero, Juan Carlos Vasquez

    2016-01-01

    We propose a new decentralized control scheme for DC Islanded microGrids (ImGs) composed by several Distributed Generation Units (DGUs) with a general interconnection topology. Each local controller regulates to a reference value the voltage of the point of common coupling of the corresponding DGU...

  18. 中国式经济分权--财政金融集分权的嬗变与绩效%Chinese-style Economic Decentralization-Evolution and Performance of Fiscal & Financial Centralization and Decentralization

    Institute of Scientific and Technical Information of China (English)

    乔梦怡

    2014-01-01

    The reform of decentralization accompanies the entire economic boom process of China. The reform of decentralization can be considered as an important institutional arrangement for the production of economic development.Researches on economic decentralization always emphasize fiscal decentralization.However,fiscal and financial measures are complementary and interactive in China.The Chinese-style economic decentralization results from the evolution and combination of fiscal and financial centralization and decentralization.It is inappropriate to analyze Chinese-style economic decentralization only from fiscal or financial perspectives.From the perspective of the institutional frontier,fiscal decentralization and financial decentralization can be integrated in-to a uniform logical framework,so as to analyze the performance and existing rationality of each economic decentralization pattern.Each decentralization mode has both advantages and disadvan-tages.The mode selected according to obj ective institutional backgrounds and financial require-ments is the optimal decentralization mode.%分权化改革是促进经济发展的重要制度安排。研究经济分权的重点往往被放在财政分权上,然而在中国,财政金融有着高度的互补性和互动性,中国式经济分权是财政金融集分权的嬗变组合,仅仅从财政或金融单一方面分析中国式经济分权都有失偏颇。从制度边界的视角出发,可以将财政分权、金融分权纳入统一逻辑框架中,进而分析各种经济分权模式的绩效以及存在的合理性。每种分权模式各有优劣,根据客观的制度背景和金融需求选择的分权模式才是最优的。

  19. Application of Cosine Zone Plates to Image Encryption

    Institute of Scientific and Technical Information of China (English)

    GE Fan; CHEN Lin-Fei; ZHAO Dao-Mu

    2008-01-01

    @@ We analyse the diffraction result of optical field after Cosine zone plate, and theoretically deduce its transform matrix. Under some conditions, its diffraction distribution is a mixture of fractional Fourier spectra. Then we use Cosine zone plate and its diffraction result to image encryption. Possible optical image encryption and decryption implementations are proposed, and some numerical simulation results are also provided.

  20. [Fundamental problems and decentralization in the Sahel. At the basis of desertification and demographic pressure].

    Science.gov (United States)

    Offisome, S

    1994-12-01

    In June 1994, a regional conference on deep-seated problems and decentralization was held in Praia, Cape Verde. Deep-seated problems and decentralization have become fashionable words, after those of devaluation and democratization, which have profoundly marked first political life then economic life in several Sahelian states. Most member states of the Permanent Committee of the Interstate Fight Against Desertification in the Sahel have undertaken fundamental reforms and have implemented national structures to bring about decentralization. The conference was an opportunity for participants to reflect on the fundamental problems and decentralization as well as to discuss ways to solve many existing problems. Participants included civil servants from national administrations, representatives of women's groups, elected officials, economic operators from the private sector, bank representatives, and communication professionals. The conference stressed the need for different players involved in development to share powers as well as the importance of recognizing the legitimacy of basic organizations. It also emphasized access to natural resources for marginalized groups (e.g., women). It insisted on legislative and institutional equality. Participants adopted a declaration which asks member states to help with the materialization of the recommendations issued at the conference. Priority questions of the declaration ranged from "what options are there to build laws and sustainable institutions in the Sahel?" to "what future is there for the Sahel in terms of population, environment, and management of natural resources?". Participants insisted on four basic principals: recognition of the legitimacy of local structures, development of a definition framework; the return to confidence in public institutions and other associated organizations; and implementation of decentralized structures.

  1. ZONING DESIGN FOR HAND­WRITTEN NUMERAL RECOGNITION

    NARCIS (Netherlands)

    Lecce Di, V.; Dimauro, G.; Guerriero, A.; Impedovo, S.; Pirlo, G.; Salzo, A.

    2004-01-01

    In the field of Optical Character Recognition (OCR), zoning is used to extract topological information from patterns. In this paper zoning is considered as the result of an optimisation problem and a new technique is presented for automatic zoning. More precisely, local analysis of feature distribut

  2. Generating chaos in the sense of Devaney via decentralized feedback control from a stable Takagi-Sugeno fuzzy system

    Institute of Scientific and Technical Information of China (English)

    Lu Jun-Guo

    2005-01-01

    The problem of making a stable Takagi-Sugeno (TS) fuzzy system chaotic in the sense of Devaney by using decentralized state feedback control is studied. The proposed decentralized feedback controller is a decentralized linear feedback controller composed of the overflow nonlinear function of the 2's complement arithmetic. The overflow nonlinearity of the 2's complement arithmetic results in a rather complex dynamics. We apply the Shi-Chen theorem to mathematically prove that the controlled system is indeed chaotic in the sense of Devaney. In particular, an explicit formula for the computation of chaotification parameters is also obtained. A numerical example is used to visualize and illustrate the theoretical results.

  3. Of decentralization of public power Ukrainian land that belonged to Lithuanian (XIII – the early XVII century

    Directory of Open Access Journals (Sweden)

    C. V. Manuilova

    2016-06-01

    Full Text Available A comprehensive crisis in Ukraine and continued military confrontation in the Donbass demonstrated the urgent need to establish effective governance, which would imply decentralization of public power. Note that in implementing the decentralization of power in Ukraine insists the International Monetary Fund; United Nations Development Program; the transfer of authority to the field and decentralization of power in Ukraine is one of the points of the Minsk agreements and obligations of Ukraine to the EU. The article deals with the Ukrainian lands topical issue features the decentralization of public power in the XIII - the beginning of XVII century. The importance of the topic due to the need to study the historical experience of the implementation of decentralization. It was, emphasized that the success of the reforms depends largely because of the historical experience and features of the decentralization of public power in the past. Characterized by the development of local government in the Ukrainian lands was part of the Lithuanian state. The purpose of the article is to clarify the characteristics of decentralization of public authority on Ukrainian lands were part of the Lithuanian state during the XVII century XIII. To address this goal, outline decentralization of public power in the state; analyze, competence of local government in the Ukrainian lands that belonged to the Lith uanian State; determine how close to the power of the people. The level of decentralization of public power in the Grand Duchy of Lithuania in the XIII - the beginning of XVII century was high. It was, found that Lithuania had not established a centralized state. It is, noted that the Board of the nobility limited the princely power. The effect of delegated deputies from different parts of the Lithuanian statehood solutions nobility Council.Clarified the facts that confirm the existence of decentralization of public power in Lithuania: the functioning of local

  4. Decentralized Identification and Control in Real-Time of a Robot Manipulator via Recurrent Wavelet First-Order Neural Network

    Directory of Open Access Journals (Sweden)

    Luis A. Vázquez

    2015-01-01

    Full Text Available A decentralized recurrent wavelet first-order neural network (RWFONN structure is presented. The use of a wavelet Morlet activation function allows proposing a neural structure in continuous time of a single layer and a single neuron in order to identify online in a series-parallel configuration, using the filtered error (FE training algorithm, the dynamics behavior of each joint for a two-degree-of-freedom (DOF vertical robot manipulator, whose parameters such as friction and inertia are unknown. Based on the RWFONN subsystem, a decentralized neural controller is designed via backstepping approach. The performance of the decentralized wavelet neural controller is validated via real-time results.

  5. Decentralized robust stabilization of discrete-time fuzzy large-scale systems with parametric uncertainties: a LMI method

    Institute of Scientific and Technical Information of China (English)

    Zhang Yougang; Xu Bugong

    2006-01-01

    Decentralized robust stabilization problem of discrete-time fuzzy large-scale systems with parametric uncertainties is considered. This uncertain fuzzy large-scale system consists of N interconnected T-S fuzzy subsystems, and the parametric uncertainties are unknown but norm-bounded. Based on Lyapunov stability theory and decentralized control theory of large-scale system, the design schema of decentralized parallel distributed compensation (DPDC) fuzzy controllers to ensure the asymptotic stability of the whole fuzzy large-scale system is proposed. The existence conditions for these controllers take the forms of LMIs. Finally a numerical simulation example is given to show the utility of the method proposed.

  6. AB318. SPR-45 Decentralization reduces nicotinic receptor-mediated canine bladder contractions in vitro

    Science.gov (United States)

    Salvadeo, Danielle M.; Frara, Nagat; Braverman, Alan S.; Barbe, Mary F.; Ruggieri, Michael R.

    2016-01-01

    Objective Bladder function depends upon several complex signaling pathways that induce either contraction or relaxation. We performed nerve re-routing surgery on bladder of decentralized dogs (reinnervated) as a model with the goal of restoring bladder function in spinal cord injured patients. The neuromuscular nicotinic receptor blocker, succinylcholine blocks spinal root-stimulated bladder contraction in vivo in reinnervated dogs, but not in sham-operated dogs. Our lab explored the function and location of nicotinic receptors involved in bladder contraction, with emphasis on their possible role in the release of other neurotransmitters such as acetylcholine or ATP in sham-operated, 12-month-decentralized and immediate-reinnervated bladders. Methods Smooth muscle strips (mucosa denuded) were isolated from the region just rostral to the trigone and suspended in muscle baths. Strips were ranked based on their contractile response to a 3-min exposure to 120 mM KCl and sorted so that the average response in each group was equal. Strips were incubated with either 1 µM atropine (ATR), 1 µM tetrodotoxin (TTX), 10 µM alpha, beta-methylene ATP (α,β-ATP) or vehicle (water) and then induced to contract with the nicotinic receptor agonists 1,1 dimethyl-4-phenyl-piperazinium iodide (DMPP, 100 µM), TC2559 (100 µM) or epibatidine (10 µM) or 1 mM nicotine itself. Results The DMPP-induced contraction was not different between sham, reinnervated or decentralized bladders (11%, 3.3%, and 3.6% of KCl contraction respectively). While the epibatidine-induced contraction in shams was not different relative to that in the reinnervated (41% vs. 27% KCl respectively), it was significantly greater than that in decentralized bladders (13% of KCl). TC2559 did not induce bladder contractions. Nicotine-induced contractions in sham-operated controls were 16% of KCl. ATR completely blocked nicotine-induced contraction while α,β-ATP had no statistically significant effect in shams. TTX

  7. Zoning Districts, Zoning, Published in 2002, Freelance.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Zoning Districts dataset, was produced all or in part from Hardcopy Maps information as of 2002. It is described as 'Zoning'. Data by this publisher are often...

  8. ROBUST SLIDING MODE DECENTRALIZED CONTROL FOR A CLASS OF NONLINEAR INTERCONNECTED LARGE-SCALE SYSTEM WITH NEURAL NETWORKS

    Institute of Scientific and Technical Information of China (English)

    CHENMou; JIANGChang-sheng; CHENWen-hua

    2004-01-01

    A new decentralized robust control method is discussed for a class of nonlinear interconnected largescale system with unknown bounded disturbance and unknown nonlinear function term. A decentralized control law is proposed which combines the approximation method of neural network with sliding mode control. The decentralized controller consists of an equivalent controller and an adaptive sliding mode controller. The sliding mode controller is a robust controller used to reduce the track error of the control system. The neural networks are used to approximate the unknown nonlinear functions, meanwhile the approximation errors of the neural networks are applied to the weight value updated law to improve performance of the system. Finally, an example demonstrates the availability of the decentralized control method.

  9. Modernization of the Public Administration System in Ukraine: Preliminary Results and Problematic Issues of the Decentralization Reform

    Directory of Open Access Journals (Sweden)

    Yaroshenko Igor V.

    2016-05-01

    Full Text Available The article is concerned with a crude summary of results of the decentralization reform in Ukraine, identification of the problematic issues that arise in the process of its implementation, and providing recommendations on how to address them. An ongoing monitoring of the implementation of the decentralization reform in Ukraine has been conducted, the level of its implementation has been evaluated. The existing problematic issues and risks of the decentralization reform have been analyzed, recommendations for dealing with them have been provided. A number of conclusions has been made, in particular, that establishing a legal framework, which is a necessity for the decentralization reform, should take place in parallel for all industry areas and not in fragmentary manner. This will provide an opportunity to not declaratively, but actually start the process of the profound transformation to ensure the improvement of quality of life of citizens, effective management of territorial development, formation and operation of the substantively selfsufficient united territorial communities.

  10. Extension of district cooling at Vienna. Central and decentral solutions; Ausbau der Kaelteversorgung in Wien. Zentrale und dezentrale Loesungen

    Energy Technology Data Exchange (ETDEWEB)

    Wallisch, Alexander [Fernwaerme Wien GmbH, Planung und Bau von Fernkaelte (Austria). Energieprojekte; Fachverband Gas und Waerme, Wien (Austria). Ausschuss Umwelt und Infrastruktur

    2009-04-15

    The extension of the district cooling system by refrigerating absorbers is very important for Fernwaerme Wien, the Vienna municipal utility. Both central and decentral solutions are employed. The author presents various concrete projects to illustrate the different concepts. (orig.)

  11. The complexities of managing forest resources in post-decentralization Indonesia: a case study from Sintang District, West Kalimantan

    NARCIS (Netherlands)

    Yasmi, Y.; Anshari, Gusti Z.; Alqadrie, S.; Budiarto, T.; Ngusmanto,; Abidin, E.; Komarudin, H.; McGrath, S.; Zulkifli,; Afifudin,

    2005-01-01

    The study attempted to understand the dynamics and complexities of forest resources management following decentralization, the interactions among stakeholders in forest resources management, and the impacts of the new legislation on local community livelihoods in Sintang District, West Kalimantan.

  12. Optimal Rescheduling of Generators for Congestion Management and Benefit Maximization in a Decentralized Bilateral Multi-transactions Power Network

    Science.gov (United States)

    Singh, Brijesh; Mahanty, Ranjit; Singh, S. P.

    2013-05-01

    This paper presents a framework to achieve an optimal power flow solution in a decentralized bilateral multitransaction-based market. An independent optimal dispatch solution has been used for each market. The interior point (IP)-based optimization technique has been used for finding a global economic optimal solution of the whole system. In this method, all the participants try to maximize their own profits with the help of system information announced by the operator. In the present work, a parallel algorithm has been used to find out a global optimum solution in decentralized market model. The study has been carried out on a modified IEEE-30 bus system. The results show that the suggested decentralized approach can provide a better optimal solution. The obtained results show the effectiveness of IP optimization-based optimal generator schedule and congestion management in the decentralized market.

  13. Eccentricity in Zone Routing Protocol for MANET

    Directory of Open Access Journals (Sweden)

    Mrs Komal Nair

    2012-06-01

    Full Text Available A Mobile Ad-Hoc Network (MANET is a decentralized network of autonomous mobile nodes, able to communicate with each other over wireless links. Due to the mobility of the nodes, the topology ofthe network changes spontaneously, therefore use of conventional routing tables maintained at fixed points (routers is not suggested. Such a network may operate in a standalone fashion. There are variousrouting protocols available for MANETs. The most popular ones are DSR, DSDV and ZRP .The zone routing protocol (ZRP is a hybrid routing protocol that proactively maintains routes within a localregion of the network. ZRP can be configured for a particular network through adjustment of a single parameter, the routing zone radius. In this paper, we address the issue of configuring the ZRP to providethe best performance for a particular network at any time with the concept of eccentricity. The results illustrate the important characteristics of different protocols based on their performance and thus suggest some improvements in the respective protocol. The tools used for the simulation are NS2 which is the main simulator, NAM (Network Animator and Tracegraph which is used for preparing the graphs from the trace files.

  14. RE-ENGINEERING GOVERNANCE; E-GOVERNMENT AS A TOOL FOR DECENTRALIZATION; GHANA AS A CASE STUDY

    OpenAIRE

    Gyaase, Patrick Ohemeng Kwadwo

    2014-01-01

    This research was undertaken to study the diffusion of E-government as a tool for decentralization, using Ghana as a case study. E-governance has been credited with the potency of facilitating good governance in countries with appreciable level of E-government maturity. Much attention is being given to E-governance by international and inter-governmental institutions. Decentralization has hitherto been the approach adopted to make government and its services accessible to the citizens, facili...

  15. Regional Decentralization, Fiscal Incentives and Privatization of Public-Owned Enterprises

    Institute of Scientific and Technical Information of China (English)

    HengpengZhu

    2004-01-01

    The tax-sharing system reform since 1994 has hardened budgetary constraints on local governments, but has not derailed the fiscal decentralization trend since China started the reform and opening up. This fiscal decentralization has provided a strong impetus to local finance, so that local governments have become quite enthusiastic in pursuing local economic development and improving local economic efficiency. As market competition intensifies, the public-owned enterprises have gradually become a financial burden on local finance. Meanwhile, the non-state sector has made an increasing contribution to the local economy and to local coffers. Therefore, it has become the optimal choice for local governments, in pursuit of their own interests, to reform the ownership structure of public-owned enterprises.

  16. Decentralized model reference adaptive sliding mode control based on fuzzy model

    Institute of Scientific and Technical Information of China (English)

    Gu Haijun; Zhang Tianping; Shen Qikun

    2006-01-01

    A new design scheme of decentralized model reference adaptive sliding mode controller for a class of MIMO nonlinear systems with the high-order interconnections is proposed. The design is based on the universal approximation capability of the Takagi - Seguno (T-S) fuzzy systems. Motivated by the principle of certainty equivalentcontrol, a decentralized adaptive controller is designed to achieve the tracking objective without computation of the T-S fuzz ymodel. The approach does not require the upper bound of the uncertainty term to be known through some adaptive estimation. By theoretical analysis, the closed-loop fuzzy control system is proven to be globally stable in the sense that all signalsinvolved are bounded, with tracking errors converging to zero. Simulation results demonstrate the effectiveness of the approach.

  17. Contextual determinants of decentralization of epidemiological surveillance for the family health team

    Directory of Open Access Journals (Sweden)

    Silvone Santa Barbara da Silva Santos

    2015-09-01

    Full Text Available This study examines the contextual determinants of implementing decentralization of epidemiological surveillance for the family health team, in a municipality in the state of Bahia, Brazil. This was an evaluative study using the political model of implementation analysis. Data were obtained through document analysis and semi-structured interviews with managers and healthcare workers. Five themes emerged: planning; training of human resources; organization of the work process; linkage within institutions; and organization of family healthcare units. The results revealed that there are difficulties such as poor infrastructure of healthcare units, creation of flexibility in labor relations and healthcare worker turnover. The study shows that there is a need for stakeholder participation in the process of implementing the policy of decentralization of epidemiological surveillance for the micro-area of intervention that comprises the family health program.

  18. Local Power -- Global Connections: linking the world to a sustainable future through decentralized energy technology

    Energy Technology Data Exchange (ETDEWEB)

    Brent, Richard; Sweet, David

    2007-07-01

    Various international dynamics are converging to increase the attractiveness of decentralized energy as a complement to existing centralized energy infrastructures. Decentralized energy (DE) technologies, including onsite renewables, high efficiency cogeneration and industrial energy recycling, offer considerable benefits to those seeking working alternatives to emerging challenges in the energy sector. DE is ideally suited to provide clean affordable energy to areas where modern energy services are currently lacking. Having smaller generators close to where energy is required ensures a safe, reliable and secure energy supply when the energy is required. Furthermore, because DE is a much cleaner alternative than conventional central power plants and the energy provided comes at a much smaller price tag DE is an increasingly acceptable alternative both in the developed and developing world. DE is sure to play a key role in any plan to build a sustainable energy future. (auth)

  19. Optimal Precoding Design and Power Allocation for Decentralized Detection of Deterministic Signals

    CERN Document Server

    Fang, Jun; Chen, Zhi; Li, Shaoqian

    2011-01-01

    We consider a decentralized detection problem in a power-constrained wireless sensor networks (WSNs), in which a number of sensor nodes collaborate to detect the presence of a deterministic vector signal. The signal to be detected is assumed known \\emph{a priori}. Given a constraint on the total amount of transmit power, we investigate the optimal linear precoding design for each sensor node. More specifically, in order to achieve the best detection performance, shall sensor nodes transmit their raw data to the fusion center (FC), or transmit compressed versions of their original data? The optimal power allocation among sensors is studied as well. Also, assuming a fixed total transmit power, we examine how the detection performance behaves with the number of sensors in the network. A new concept "detection outage" is proposed to quantify the reliability of the overall detection system. Finally, decentralized detection with unknown signals is studied. Numerical results are conducted to corroborate our theoreti...

  20. Decentralized adaptive robust controller design for complex system based on partition of unity

    Institute of Scientific and Technical Information of China (English)

    WANG Wenqing; HAN Chongzhao

    2007-01-01

    A new method for designing decentralized adaptive robust controllers was proposed which focuses on a class of more general uncertain complex systems,using the concept of the partition of unity in differential geometry to deal with system uncertainties.In this method the uncertainty of the system to be controlled was normalized firstly,and then the partition of unity that was subordinated to an open covering of state variables compact set was constructed.Subsequently the approximation was realized by using its property that can approximate nonlinear continuous function with arbitrary precision,and then the decentralized adaptive robust controller of complex systems and adaptive laws of approximate parameter estimation were designed.Compared to existing methods,the proposed algorithm requires simpler assumed conditions and no complicated computations.Simulation result shows that the method is valid.

  1. ENGINE SENSOR FAULT DIAGNOSIS USING MAIN AND DECENTRALIZED NEURAL NET WORKS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    This Paper presents a methodology for solving the sensor failure detection, isolation and accommodation of aeroengine control systems using on-line learning neural networks(NN), which has one main NN and a set of decentralized NNs. Changes in the system dynamics are monitored by the on-line learning NN. When a failure occurs in some sensor, the sensor failure detection can be accomplished with high precision, and the sensor failure accommodation can be achieved by replacing the value from the failed sensor with its estimate from the decentralized NN. By integrating the optimal estimation and failure logic, this method can detect soft failures. Simulation of one kind of turboshaft engine control system with this multiple neural network architecture shows that the ANN developed can detect and isolate hard and soft sensor failures timely and provide accurate accommodation.

  2. Decentralized vibration control of a multi-link flexible robotic manipulator using smart piezoelectric transducers

    Science.gov (United States)

    Halim, Dunant; Luo, Xi; Trivailo, Pavel M.

    2014-11-01

    The work in this paper is aimed to investigate the use of a decentralized control system for suppressing vibration of a multi-link flexible robotic manipulator using embedded smart piezoelectric transducers. To achieve this, a non-linear dynamic model of a flexible robotic manipulator with smart piezoelectric actuators/sensors, is developed based on the co-rotational finite element method. The method incorporates multiple co-ordinate (co-rotational) systems which rotate and translate with each element, so that the geometric non-linearity present in rotating manipulator system can be dealt with efficiently. The placement of piezoelectric actuators and sensors over the flexible links are considered for the application of decentralized control system. A numerical study shows that the developed co-rotational finite element method can be utilized to investigate the piezoelectric actuator/sensor placement and vibration control performances for a multi-link flexible manipulator undertaking complicated motion.

  3. Decentralized identification for multivariable integrating processes with time delays from closed-loop step tests.

    Science.gov (United States)

    Mei, Hua; Li, Shaoyuan

    2007-04-01

    In order to identify those multivariable processes with integrating factors in their transfer function matrices, a simple yet robust decentralized identification method from closed-loop step tests is proposed. By the frequency response matrix computed from the closed-loop system data and the knowledge of the decentralized controller, the structural information of the multivariable integrating process is determined firstly and then the continuous parametric model with dead times is approximated similarly with the parameterization of the open-loop stable process. Computer simulations and an application to a 3 x 3 integrating multiple-tank water level system verify the validation of the proposed method even if the closed-loop system is affected by some stochastic noise sources.

  4. Decentralized Orchestration of Composite Ogc Web Processing Services in the Cloud

    Science.gov (United States)

    Xiao, F.; Shea, G. Y. K.; Cao, J.

    2016-09-01

    Current web-based GIS or RS applications generally rely on centralized structure, which has inherent drawbacks such as single points of failure, network congestion, and data inconsistency, etc. The inherent disadvantages of traditional GISs need to be solved for new applications on Internet or Web. Decentralized orchestration offers performance improvements in terms of increased throughput and scalability and lower response time. This paper investigates build time and runtime issues related to decentralized orchestration of composite geospatial processing services based on OGC WPS standard specification. A case study of dust storm detection was demonstrated to evaluate the proposed method and the experimental results indicate that the method proposed in this study is effective for its ability to produce the high quality solution at a low cost of communications for geospatial processing service composition problem.

  5. Transformations of the Political Communication in Social Media Era – from Mediatization to Decentralization

    Directory of Open Access Journals (Sweden)

    Tănase Tasente

    2014-06-01

    Full Text Available The political communication in media era performs on two dimensions: the horizontal dimension – between political actors and journalists – and on vertical dimension – the media product is decentralized to the consumer public. In Social Media Era, the horizontal dimension completely disappears and the communication is routed by the online opinion leaders in the social groups. Thus, in the new public space, the main communication actors are not journalists and politicians, but publicreceptor, which plays the role of opinion leaders. In Social Media, we can talk a lot about “the power of the receptor”, that is decentralizing, without intermediaries, the political message to discuss it in the social groups to which they belong.

  6. Decentralized system identification using stochastic subspace identification for wireless sensor networks.

    Science.gov (United States)

    Cho, Soojin; Park, Jong-Woong; Sim, Sung-Han

    2015-04-08

    Wireless sensor networks (WSNs) facilitate a new paradigm to structural identification and monitoring for civil infrastructure. Conventional structural monitoring systems based on wired sensors and centralized data acquisition systems are costly for installation as well as maintenance. WSNs have emerged as a technology that can overcome such difficulties, making deployment of a dense array of sensors on large civil structures both feasible and economical. However, as opposed to wired sensor networks in which centralized data acquisition and processing is common practice, WSNs require decentralized computing algorithms to reduce data transmission due to the limitation associated with wireless communication. In this paper, the stochastic subspace identification (SSI) technique is selected for system identification, and SSI-based decentralized system identification (SDSI) is proposed to be implemented in a WSN composed of Imote2 wireless sensors that measure acceleration. The SDSI is tightly scheduled in the hierarchical WSN, and its performance is experimentally verified in a laboratory test using a 5-story shear building model.

  7. [Mes differ by positioning: empirical testing of decentralized dynamics of the self].

    Science.gov (United States)

    Mizokami, Shinichi

    2013-10-01

    The present study empirically tested the conceptualization of the decentralized dynamics of the self proposed by Hermans & Kempen (1993), which they developed theoretically and from clinical cases, not from large samples of empirical data. They posited that worldviews and images of the self could vary by positioning even in the same individual, and denied that the ego was an omniscient entity that knew and controlled all aspects of the self (centralized ego). Study 1 tested their conceptualization empirically with 47 university students in an experimental group and 17 as a control group. The results showed that the scores on the Rosenberg's self-esteem scale and images of the Mes in the experimental group significantly varied by positioning, but those in the control group did not. Similar results were found in Study 2 with a sample of 120 university students. These results empirically supported the conceptualization of the decentralized dynamics of the self.

  8. Decentralized control of ecological and biological networks through Evolutionary Network Control

    Directory of Open Access Journals (Sweden)

    Alessandro Ferrarini

    2016-09-01

    Full Text Available Evolutionary Network Control (ENC has been recently introduced to allow the control of any kind of ecological and biological networks, with an arbitrary number of nodes and links, acting from inside and/or outside. To date, ENC has been applied using a centralized approach where an arbitrary number of network nodes and links could be tamed. This approach has shown to be effective in the control of ecological and biological networks. However a decentralized control, where only one node and the correspondent input/output links are controlled, could be more economic from a computational viewpoint, in particular when the network is very large (i.e. big data. In this view, ENC is upgraded here to realize the decentralized control of ecological and biological nets.

  9. A Decentralized VPN Service over Generalized Mobile Ad-Hoc Networks

    Science.gov (United States)

    Fujita, Sho; Shima, Keiichi; Uo, Yojiro; Esaki, Hiroshi

    We present a decentralized VPN service that can be built over generalized mobile ad-hoc networks (Generalized MANETs), in which topologies can be represented as a time-varying directed multigraph. We address wireless ad-hoc networks and overlay ad-hoc networks as instances of Generalized MANETs. We first propose an architecture to operate on various kinds of networks through a single set of operations. Then, we design and implement a decentralized VPN service on the proposed architecture. Through the development and operation of a prototype system we implemented, we found that the proposed architecture makes the VPN service applicable to each instance of Generalized MANETs, and that the VPN service makes it possible for unmodified applications to operate on the networks.

  10. Controllability analysis and decentralized control of a wet limestone flue gas desulfurization plant

    Energy Technology Data Exchange (ETDEWEB)

    Perales, A.L.V.; Ortiz, F.J.G.; Ollero, P.; Gil, F.M. [University of Seville, Seville (Spain)

    2008-12-15

    Presently, decentralized feedback control is the only control strategy used in wet limestone flue gas desulfurization (WLFGD) plants. Proper tuning of this control strategy is becoming an important issue in WLFGD plants because more stringent SO{sub 2} regulations have come into force recently. Controllability analysis is a highly valuable tool for proper design of control systems, but it has not been applied to WLFGD plants so far. In this paper a decentralized control strategy is designed and applied to a WLFGD pilot plant taking into account the conclusions of a controllability analysis. The results reveal that good SO{sub 2} control in WLFGD plants can be achieved mainly because the main disturbance of the process is well-aligned with the plant and interactions between control loops are beneficial to SO{sub 2} control.

  11. Decentralized control of transmission rates in energy-critical wireless networks

    KAUST Repository

    Xia, Li

    2013-06-01

    In this paper, we discuss the decentralized optimization of delay and energy consumption in a multi-hop wireless network. The goal is to minimize the energy consumption of energy-critical nodes and the overall packet transmission delay of the network. The transmission rates of energy-critical nodes are adjustable according to the local information of nodes, i.e., the length of packets queued. The multi-hop network is modeled as a queueing network.We prove that the system performance is monotone w.r.t. (with respect to) the transmission rate, thus the “bang-bang” control is an optimal control. We also prove that there exists a threshold type control policy which is optimal. We propose a decentralized algorithm to control transmission rates of these energy-critical nodes. Some simulation experiments are conducted to demonstrate the effectiveness of our approach.

  12. Potentiometric strip cell based on carbon nanotubes as transducer layer: toward low-cost decentralized measurements.

    Science.gov (United States)

    Rius-Ruiz, F Xavier; Crespo, Gastón A; Bejarano-Nosas, Diego; Blondeau, Pascal; Riu, Jordi; Rius, F Xavier

    2011-11-15

    In this study, we developed a potentiometric planar strip cell based on single-walled carbon nanotubes that aims to exploit the attributes of solid-contact ion-selective electrodes for decentralized measurements. That is, the ion-selective and reference electrodes have been simultaneously miniaturized onto a plastic planar substrate by screen-printing and drop-casting techniques, obtaining disposable strip cells with satisfactory performance characteristics (i.e., the sensitivity is 57.4 ± 1.3 mV/dec, the response time is ≤30 s within the linear range from log a(K+) = -5 to -2, and the limit of detection is -6.5), no need of maintenance during long dry storage, quick signal stabilization, and light insensitivity in short-term measurements. We also show how the new potentiometric strip cell makes it possible to perform decentralized and rapid determinations of ions in real samples, such as saliva or beverages.

  13. A Repeated Game Formulation of Energy-Efficient Decentralized Power Control

    CERN Document Server

    Treust, Mael Le

    2010-01-01

    Decentralized multiple access channels where each transmitter wants to selfishly maximize his transmission energy-efficiency are considered. Transmitters are assumed to choose freely their power control policy and interact (through multiuser interference) several times. It is shown that the corresponding conflict of interest can have a predictable outcome, namely a finitely or discounted repeated game equilibrium. Remarkably, it is shown that this equilibrium is Pareto-efficient under reasonable sufficient conditions and the corresponding decentralized power control policies can be implemented under realistic information assumptions: only individual channel state information and a public signal are required to implement the equilibrium strategies. Explicit equilibrium conditions are derived in terms of minimum number of game stages or maximum discount factor. Both analytical and simulation results are provided to compare the performance of the proposed power control policies with those already existing and ex...

  14. Impact of heterogeneity and socioeconomic factors on individual behavior in decentralized sharing ecosystems.

    Science.gov (United States)

    Gavaldà-Miralles, Arnau; Choffnes, David R; Otto, John S; Sánchez, Mario A; Bustamante, Fabián E; Amaral, Luís A N; Duch, Jordi; Guimerà, Roger

    2014-10-28

    Tens of millions of individuals around the world use decentralized content distribution systems, a fact of growing social, economic, and technological importance. These sharing systems are poorly understood because, unlike in other technosocial systems, it is difficult to gather large-scale data about user behavior. Here, we investigate user activity patterns and the socioeconomic factors that could explain the behavior. Our analysis reveals that (i) the ecosystem is heterogeneous at several levels: content types are heterogeneous, users specialize in a few content types, and countries are heterogeneous in user profiles; and (ii) there is a strong correlation between socioeconomic indicators of a country and users behavior. Our findings open a research area on the dynamics of decentralized sharing ecosystems and the socioeconomic factors affecting them, and may have implications for the design of algorithms and for policymaking.

  15. FBC utilization prospects in decentralized cogeneration units in Caucasus region countries

    Directory of Open Access Journals (Sweden)

    Skodras George

    2003-01-01

    Full Text Available Great differences are encountered among Caucasus region countries with respect to energy resources reserves and economic conditions. Thermal power plants consist of obsolete and inefficient units, while the Soviet-type large heating systems in the area collapsed after 1992 and their reconstruction is considered uneconomic. Renovation needs of the power and heat sector, and the potential of Fluidised Bed Combustion implementations in decentralized cogeneration units were investigated, since operating oil and gas power plants exhibit high fuel consumption, low efficiency and poor environmental performance. Results showed significant prospects of Fluidised Bed Combustion utilization in decentralized cogeneration units in the Caucausus region heat and power sector. Their introduction constitutes an economically attractive way to cover power and heat demands and promotes utilization of domestic energy resources in all of three countries, provided that financial difficulties could be confronted.

  16. DECENTRALIZED ORCHESTRATION OF COMPOSITE OGC WEB PROCESSING SERVICES IN THE CLOUD

    Directory of Open Access Journals (Sweden)

    F. Xiao

    2016-09-01

    Full Text Available Current web-based GIS or RS applications generally rely on centralized structure, which has inherent drawbacks such as single points of failure, network congestion, and data inconsistency, etc. The inherent disadvantages of traditional GISs need to be solved for new applications on Internet or Web. Decentralized orchestration offers performance improvements in terms of increased throughput and scalability and lower response time. This paper investigates build time and runtime issues related to decentralized orchestration of composite geospatial processing services based on OGC WPS standard specification. A case study of dust storm detection was demonstrated to evaluate the proposed method and the experimental results indicate that the method proposed in this study is effective for its ability to produce the high quality solution at a low cost of communications for geospatial processing service composition problem.

  17. Cooperative Energy Management of Hybrid DC Renewable Grid Using Decentralized Control Strategies

    Directory of Open Access Journals (Sweden)

    Mehrdad Beykverdi

    2016-10-01

    Full Text Available This paper attempted to control a hybrid DC microgrid in islanded operation mode using decentralized power management strategies. Proposed adaptive I/V characteristic for hybrid photovoltaic (PV and battery energy storage system (BESS and wind turbine generator (WTG adapts the distributed energy resources (DER behavior independently in accordance with the load demand. Hence, the PV module can spend its maximum power on load demand and spend the extra power for charging the BESS, which will regulate DC bus voltage and maintain the power balance within the microgrid. When load demand is beyond the maximum generation power of PV unit, WTG will supply the energy shortage. The proposed control system was applied on the DC microgrid in order to achieve control objectives through a decentralized procedure, without telecommunication links. In order to validate the proposed strategies, the control system was implemented on a DC microgrid within MATLAB/SIMULINK, where the simulation results were analyzed and validated.

  18. A scalable, locality aware, fault-tolerant, and decentralized location scheme for distributed networks

    Institute of Scientific and Technical Information of China (English)

    BAI Hai-huan; JIANG Jun-jie; ZOU Fu-tai; WANG Wei-nong

    2005-01-01

    This paper presents Isotope, an efficient, locality aware, fault-tolerant, and decentralized scheme for data location in distributed networks. This scheme is designed based on the mathematical model of decentralized location services and thus has provable correctness and performance. In Isotope, each node needs to only maintain linkage information with about O( log n) other nodes and any node can be reached within O( log n) routing hops. Compared with other related schemes, Isotope' s average locating path length is only half that of Chord,and its locating performance and locality-awareness are sinilar to that of Pastry and Tapestry. In addition, Isotope is more suitable for constantly changing networks because it needs to exchange only O(log n) O(log n)messages to update the routing information for nodes arrival, departure and failure.

  19. Non-fragile decentralized H∞ controller design for uncertain linear systems

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhihua; Chen Yuepeng; Zhang Qingling

    2008-01-01

    Considering the design problem of non-fragile decentralized H∞ controller with gain variations, the dynamic feedback controller by measurement feedback for uncertain linear systems is constructed and studied. The parameter uncertainties are considered to be unknown but norm bounded. The design procedures are investigated in terms of positive definite solutions to modify algebraic Riccati inequalities. Using information exchange among local controllers, the designed non-fragile decentralized H∞ controllers guarantee that the uncertain closed-loop linear systems are stable and with H∞ -norm bound on disturbance attenuation. A sufficient condition that there are such non-fragile H∞ controllers is obtained by algebraic Riccati inequalities. The approaches to solve modified algebraic Riccati inequalities are carried out preliminarily. Finally, a numerical example to show the validity of the proposed approach is given.

  20. [The decentralization and municipalization of health services in Säo Paulo, Brazil].

    Science.gov (United States)

    Mercadante, O A; Yunes, J; Chorny, A H

    1994-05-01

    The health system in Brazil has undergone profound changes since the 1980s. In the state of São Paulo, the processes of decentralization to the municipio and regional levels, as well as integration of health services, began in 1983. This study describes the strategies adopted by the Ministry of Health of the state of São Paulo to implement these processes and create 65 regional health offices, and discusses the role of these offices in the new unified health system. It is concluded that decentralization has resulted in increased local government participation in financing the health system, that production of medical and community health services has grown, and that health indicators have improved.