42 research outputs found
Water Rights Analysis Package (WRAP) Modeling System Reference Manual
The Texas Water Resources Institute (TWRI), and many other agencies and organizations, have worked with Ralph Wurbs over the years to develop WRAP (the Water Rights Analysis Package). The WRAP model simulates management of the water resources of a river basin, or multiple-basin region, under a priority-based water allocation system. The model facilitates assessment of hydrologic and institutional water availability/reliability for existing and proposed requirements for water use and management. Basin-wide impacts of water resources development projects and management strategies may be evaluated. The software package is generalized for application to any river/reservoir/use system, with input files being developed for the particular river basin of concern. The model is documented by reference and users manuals that may be downloaded from this site along with the software. WRAP is incorporated in the Texas Commission on Environmental Quality (TCEQ) Water Availability Modeling (WAM) System
NASA SBIR abstracts of 1991 phase 1 projects
The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included
Feature Papers of Water Resources Management, Policy and Governance
Water resource management includes the consideration of all disciplines of hydrology and water sources. Water supplies are allocated and diverted to cover the water needs of a range of agricultural, municipal, industrial, hydro-electrical, and ecological water uses. These water uses are, usually, very competitive, as the available water resources are limited and it is not possible to cover the total water needs in a basin, requiring the setting of water use priorities to best serve societal and ecological needs. To manage the water resources and waterworks may, sometimes, lead to confrontational deliberations and negotiations. As a result, water resource management is one of the world’s greatest challenges due to competition for limited resources, regional disparities in water supply and affluence, mounting global water demand, aquifer depletion, and pollution- and climate-change-induced water stress. Proper policy and governance for sustainable water resource management is essential and require new fresh ideas, innovation, and international cooperation. This book includes seven papers by invited renowned researchers and engineers to cover issues of water resource management, governance, and policy. These issues include the following topics: Integrated water resource management; Water resource systems and water availability; National and international water policy, institutional arrangements, and water law; Water conflict resolution, public participation, and decision making; Water resource management, policy and governance in socially and environmentally sensitive areas and regions
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Logic, parallelism and semantic networks : the binary predicate execution model
This thesis develops the Binary Predicate Execution Model; a distributed, massively-parallel system for semantic networks and knowledge bases that is built on a subset of first-order predicate logic. The use of logic gives the model an easily-understood programming paradigm and a well-defined semantics of execution. When expressed in binary predicates, a simple graphical interpretation can be used. All program facts are represented in an assertion graph. Each vertex is associated with a term appearing in a fact and the edges are labeled with the predicate names. Similar graphs are also associated with each rule body and the query. Finding all possible solutions corresponds to finding all possible matches between the query graph and the assertion graph. Invoking a rule corresponds to substituting the graph of its body constrained by the dependencies between its arguments. This can be implemented in a parallel, message-passing fashion where the assertion graph vertices are active processing elements which asynchronously exchange messages identifying different parts of the query that remain to be matched and containing any binding information from previous matching required to accomplish this. The model is data-driven since every message can be immediately processed without the need for any centralized control or centralized memory. By restricting how functional terms can occur, distributed data structures and remote data look-ups for unification are eliminated. Thus, the model's performance on increasingly larger problems scales-up given increasingly larger machines in most cases. Architectural support for the model is investigated and simulation results of a relatively simple software implementation are reported. This suggests performance on the order of 10^5 logical inferences per second for 256 processing elements in an n-cube configuration. Further research directions, including that of increasing efficiency, are discussed
Implementation of New Multiple Access Technique Encoder for 5G Wireless Telecomunication Networks
RÉSUMÉ Les exigences de la connectivité mobile massive de différents appareils et de diverses applications déterminent les besoins des prochaines générations de technologies mobiles (5G) afin de surmonter les demandes futures. L'expansion significative de la connectivité et de la densité du trafic caractérisent les besoins de la cinquième génération de réseaux mobiles. Par conséquent, pour la 5G, il est nécessaire d'avoir une densité de connectivité beaucoup plus élevée et une plus grande
portée de mobilité, un débit beaucoup plus élevé et une latence beaucoup plus faible. En raison de l'exigence d'une connectivité massive, de nombreuses nouvelles technologies
doivent être améliorées: le codage des canaux, la technique d'accès multiple, la modulation et la diversité, etc. Par conséquent, compte tenu de l'environnement 5G, surcoût de signalisation et de la latence devrait être pris en compte [1]. En outre, l'application de la virtualisation des accès sans fil (WAV) devrait également être considérée et, par conséquent, il est également nécessaire de concevoir la plate-forme matérielle prenant en charge les nouvelles normes pour la mise en œuvre des émetteurs-récepteurs virtuels. L'une des nouvelles technologies possibles pour la 5G est l'accès multiple pour améliorer
le débit. Par conséquent, au lieu d'OFDMA utilisé dans la norme LTE (4G), l'application d'une nouvelle technique d'accès multiple appelée Sparse Code Multiple Access (SCMA) est investiguée dans cette dissertation. SCMA est une nouvelle technique d'accès multiple non orthogonale du
domaine fréquentiel proposée pour améliorer l'efficacité spectrale de l'accès radio sans fil [2]. L'encodage SCMA est l'un des algorithmes les plus simples dans les techniques d'accès multiple qui offre l'opportunité d'expérimenter des méthodes génériques de mise en oeuvre. En outre, la nouvelle méthode d'accès multiple est supposée fournir un débit plus élevé. Le choix du codage
SCMA avec moins de complexité pourrait être une approche appropriée. La cible fixée pour cette recherche était d'atteindre un débit d’encodage de plus de 1 Gbps pour le codeur SCMA. Les implémentations de codage SCMA ont été effectuées à la fois en logiciel et en matériel
pour permettre de les comparer. Les implémentations logicielles ont été développées avec le langage de programmation C. Parmi plusieurs conceptions, la performance a été améliorée en utilisant différentes méthodes pour augmenter le parallélisme, diminuer la complexité de calcul et par conséquent le temps de traitement.----------ABSTRACT The demands of massive mobile connectivity of different devices and diverse applications
at the same time set requirments for next generations of mobile technology (5G). The significant expansion of connectivity and traffic density characterize the requirements of fifth generation mobile. Therefore, in 5G, there is a need to have much higher connectivity density, higher mobility ranges, much higher throughput, and much lower latency. In pursuance of the requirement of massive connectivity, numerous technologies must be
improved: channel coding, multiple access technique, modulation and diversity, etc. For instance,
with 5G, the cost of signaling overhead and latency should be taken into account [1]. Besides, applying wireless access virtualization (WAV) should be considered and there is also a need to have effective implementations supporting novel virtual transceiver. One of the possible new technologies for 5G is exploiting multiple access techniques to improve throughput. Therefore, instead of OFDMA in LTE (4G), applying a new multiple access
technique called Sparse Code Multiple Access (SCMA) is an approach considered in this dissertation. SCMA is a new frequency domain non-orthogonal multiple access technique proposed to improve spectral efficiency of wireless radio access [2]. SCMA encoding is one of the simplest
multiple access technique that offers an opportunity to experiment generic implementation methods. In addition, the new multiple access method is supposed to provide higher throughput, thus choosing SCMA encoding with less complexity could be an appropriate approach. The target
with SCMA was to achieve an encoding throughput of more that 1Gbps. SCMA encoding implementations were done both in software and hardware to allow comparing them. The software implementations were developed with the C programing language. Among several designs, the performance was improved by using different methods to increase
parallelism, decrease the computational complexity and consequently the processing time. The best achieved results with software implementations offer a 3.59 Gbps throughput, which is 3.5 times more that the target. For hardware implementation, high level synthesis was experimented. In order to do that, the C based functions and testbenches which were developed for software implementations, were
used as inputs to Vivado HLS
Mecanismos de suporte à execução concorrente de programas em lógica
Dissertacção apresentada para a obtenção do
Grau de Mestre em Engenharia Informática pela
Universidade Nova de Lisboa, Faculdade de
Ciências e Tecnologia.A evolução do hardware dos computadores para arquitecturas paralelas, incentivou a concepção de
novos modelos de programação e o desenvolvimento dos sistemas de suporte à execução correspondentes,
de forma a conseguir uma melhor exploração do paralelismo. A linguagem de programação
Prolog, pelas suas características declarativas e operacionais, tem vindo a ser objecto de estudo nesta área, através de adaptações da linguagem e/ou da sua máquina de inferência.
Este trabalho incide sobre os aspectos de concepção e implementação de um modelo de um sistema
de suporte à execução de programas em Prolog, em arquitecturas de múltiplos processadores,
com unidades de memória fisicamente distribuídas.
O modelo propõe extensões a um executor de Prolog convencional, de forma a disponibilizar
funcionalidades que permitam o controlo do paralelismo e da distribuição. Estas funcionalidades
podem ser utilizadas para a implementação de modelos de linguagens lógicas concorrentes de mais
alto nível, ou então serem utilizadas directamente para a programação de sistemas distribuídos, em
que múltiplos executores Prolog cooperam na resolução de um golo, comunicando com base em
mensagens. Para avaliar a funcionalidade do modelo proposto, concebeu-se e implementou-se um sistema de distribuição de golos Prolog, que permite recorrer a diversas estratégias para composição sequencial e paralela de golos, escondendo os aspectos de gestão˜ao explícita dos recursos efectivos.
A dissertação inclui uma discussão dos aspectos mais relevantes da realização do protótipo do modelo proposto sobre uma arquitectura baseada em Transputers