Core Losses and Torque Ripple in IPM Machines: Dedicated Modeling and Design Trade Off

The proper combination of stator and rotor slot numbers is pursued in the design of interior permanent-magnet (IPM) motors with wide constant-power speed range. At high speed, in the flux-weakening region, the arising of stator and rotor iron losses due to magnetomotive-force (MMF) spatial harmonics limits the IPM motor performance. Torque ripple is another problem for this kind of machines, both at low and high speed. The numbers of stator slots and rotor equivalent slots have a major impact on both the loss and ripple aspects. A simplified model is proposed here in order to evaluate both problems with a general approach and point out the possible design tradeoff. With respect to previous models in the literature, both stator and rotor losses are included, and a more comprehensive approach is followed in the description of the rotor MMF harmonics. The model's effectiveness is tested through finite element analysis simulations and some experimental results. The proposed approach is useful for the selection of the IPM machine structure according to the specific requirements of the applicatio

Context constraint integration and validation in dynamic web service compositions

System architectures that cross organisational boundaries are usually implemented based on Web service technologies due to their inherent interoperability benets. With increasing exibility requirements, such as on-demand service provision, a dynamic approach to service architecture focussing on composition at runtime is needed. The possibility of technical faults, but also violations of functional and semantic constraints require a comprehensive notion of context that captures composition-relevant aspects. Context-aware techniques are consequently required to support constraint validation for dynamic service composition. We present techniques to respond to problems occurring during the execution of dynamically composed Web services implemented in WS-BPEL. A notion of context { covering physical and contractual faults and violations { is used to safeguard composed service executions dynamically. Our aim is to present an architectural framework from an application-oriented perspective, addressing practical considerations of a technical framework

Rural Alaska Corrections Plan (A Summary)

Efforts to improve correctional services in the rural, predominantly Native communities of Alaska have been going on since before statehood. Complete implementation of plans developed by the Alaska Criminal Justice Planning Agency during the 1970s have been hampered by a number of factors: (1) the scope of the planning has tended to be confined to correctional facilities; (2) the problems faced by corrections in Alaska are complicated by diversity of communities served; (3) financial requirements have exceeded available resources; (4) the authority and responsibility for achieving the plans' objectives were unclear. This document offers proposals for a rural corrections plan which offers a comprehensive, systemic — rather than purely correctional — approach for improving public safety and corrections in rural Alaska. It describes the existing situation, philosophy, coordination and planning, organizational proposals, financing, and implementation.Alaska Corrections Master Plan CommitteeTentative Recommendations / Introduction / Background / Philosophy / Coordination / Organization: Statewide Operations; Local Community Operations / Financing / Implementation / Ma

Toward collisions produced in requirements rankings: A qualitative approach and experimental study

Requirements prioritization is an important issue that determines the way requirements are selected and processed in software projects. There already exist specific methods to classify and prioritize requirements, most of them based on quantitative measures. However, most of existing approaches do not consider collisions, which are an important concern in large-scale requirements sets and, more specifically, in agile development processes where requirements have to be uniquely selected for each software increment. In this paper, we propose QMPSR (Qualitative Method for Prioritizing Software Requirements), an approach that features the prioritization of requirements by considering qualitative elements that are related to the project's priorities. Our approach highlights a prioritization method that has proven to reduce collisions in software requirements rankings. Furthermore, QMPSR improves accuracy in classification when facing large-scale requirements sets, featuring no scalability problems as the number of requirements increases. We formally introduce QMPSR and then define prioritization effort and collision metrics to carry out comprehensive experiments involving different sets of requirements, comparing our approach with well-known existing prioritization methods. The experiments have provided satisfactory results, overcoming existing approaches and ensuring scalabilityThis work was partially supported by the Spanish Government [grant number RTI2018-095255-B-I00 ] and the Madrid Research Council [grant number P2018/TCS-4314

Validation Of Quality Requirements Through Requirements-Based Testing With Semi-Formalised Model

The usage of software system and applications has increased massively to fulfill various kind of purpose for organization,business and individual.In this case, high quality software system and application are required to ensure it provides the intended functionalities.To achieve quality software system and application,a good quality of requirements needs to be defined and validated.However,it is difficult to accomplish due to the flexibility of natural language requirements that can be confusing and easily misinterpreted.This can lead to requirements-related problems such as incorrectness, incompleteness and inconsistency.These errors in requirements will produce defective software that can lead to undesirable and non-acceptance by stakeholders. Therefore,it is crucial for the software requirements to fulfill basic quality attributes such as correctness, completeness,and consistency (3Cs).Motivated from these problems,the main objective of this studyis to develop an automated approach to validate the quality of requirements through Requirements-Based Testing methodology with semi-formalized model.This studyproposes a new automated approach to assist the requirements engineer and client-stakeholders to validate the quality of requirements.For this,we generate abstract tests by integratingRequirements-based Testing (RBT) methodology and rapid prototyping with semi-formalized models:Essential Use Cases (EUCs) and Essential User Interface (EUI).Next,we have developed pattern libraries to support the automatic extraction of abstract tests from the EUC model.They are test requirements pattern library and testcase pattern library.Here,an automated tool support called TestMEReq is also developed to realize the approach.The test-authoring template to assist requirements engineer to write accurate tests is also developed.Then,a real-time collaborative approachis also integrated with the tool to encourage users’ involvement in the validation process as well as to support better communication and collaboration among stakeholders.Finally,a comprehensive evaluation of the approach,comprising experiments of correctness test and usability test were conducted.In summary,the findings of the evaluations show that our approach can contribute to the body of knowledge of requirements engineering especially in enhancing the quality of requirements at the earliest stage.It is found that the approach is able to enhance the correctness level of the elicited requirements compared to the manual approach and produce correct generation of test.The results of the usability tests show that the approach is useful and helpful in validating the quality of requirements at the early stage of software development and able to ease the requirements validation process

Federated Learning for 6G: Applications, Challenges, and Opportunities

Standard machine-learning approaches involve the centralization of training data in a data center, where centralized machine-learning algorithms can be applied for data analysis and inference. However, due to privacy restrictions and limited communication resources in wireless networks, it is often undesirable or impractical for the devices to transmit data to parameter sever. One approach to mitigate these problems is federated learning (FL), which enables the devices to train a common machine learning model without data sharing and transmission. This paper provides a comprehensive overview of FL applications for envisioned sixth generation (6G) wireless networks. In particular, the essential requirements for applying FL to wireless communications are first described. Then potential FL applications in wireless communications are detailed. The main problems and challenges associated with such applications are discussed. Finally, a comprehensive FL implementation for wireless communications is described

A computational evaluation of constructive and improvement heuristics for the blocking flow shop to minimize total flowtime

This paper focuses on the blocking flow shop scheduling problem with the objective of total flowtime minimisation. This problem assumes that there are no buffers between machines and, due to its application to many manufacturing sectors, it is receiving a growing attention by researchers during the last years. Since the problem is NP-hard, a large number of heuristics have been proposed to provide good solutions with reasonable computational times. In this paper, we conduct a comprehensive evaluation of the available heuristics for the problem and for related problems, resulting in the implementation and testing of a total of 35 heuristics. Furthermore, we propose an efficient constructive heuristic which successfully combines a pool of partial sequences in parallel, using a beam-search-based approach. The computational experiments show the excellent performance of the proposed heuristic as compared to the best-so-far algorithms for the problem, both in terms of quality of the solutions and of computational requirements. In fact, despite being a relative fast constructive heuristic, new best upper bounds have been found for more than 27% of Taillard’s instances.Ministerio de Ciencia e Innovación DPI2013-44461-P/DP

A Multi-Agent based Configuration Process for Mass Customization

Large product variety in mass customization involves a high internal complexity level inside a companyís operations, as well as a high external complexity level from a customerís perspective. In order to reach a competitive advantage through mass customization, it is necessary to cope with both problems. This is done within the scope of variety formation and variety steering tasks: Variety formation supports customers during the configuration task according to their preferences and knowledge, variety steering tasks internally deal with finding the customizerís optimal offer. Driven by this economic background, we present a comprehensive multi-agent based design for a configuration process in this paper. It is identified as a suitable solution approach integrating both perspectives. The mass customized products are assumed to be based on a modular architecture and each module variant is associated with an autonomous rational agent. Agents must compete with each other in order to join product variants which suit real customersí requirements. The negotiation process is based on a market mechanism supported by the target costing concept and a Dutch auction.Multi-agent systems; Configuration process; Market mechanism; Mass Customization