Object-Oriented Approach to the Enhancement of Energy Management Systems Software Engineering

This paper presents the idea of an operational model of a power system as the background for Energy Management Systems (EMS) software. Due to the Object Oriented Approach, with use of the proposed model, all kinds of standard power system analyses can be provided. The objects and their hierarchy is organized in such a way that all inconveniences well known in practical applications (multiwinding transformers, mutually coupled lines, busbar couplers, tapped lines, dummy nodes, control systems, FACTS devices, etc.) are taken into account and included in consistent data structures. Possibilities for a clear connection between operational models and numerical models of power systems are indicated.     

Five decades of Computer-Aided Ship Design

This article will present a synoptical review of key developments in Computer-Aided Ship Design since its inception about five decades ago. Milestone events and major innovations will be identified in several categories of ship design application with the principal emphasis on the methodologies, the modeling and the integration of the ship design process. The discussion will address many specific subtasks of ship design on the common platform of a human-guided, computer-based decision process.     

Graph theory augmented math programming approach to identify minimal reaction sets in metabolic networks

Bioprocesses are of growing importance as an avenue to produce chemicals. Microorganisms containing only desired catalytic and replication capabilities in their metabolic pathways are expected to offer efficient processes for chemical production. Realizing such minimal cells is the holy grail of metabolic engineering. In this paper, we propose a new method that combines graph-theoretic approaches with mixed-integer liner programming (MILP) to design metabolic networks with minimal reactions. Existing MILP based computational approaches are computationally complex especially for large networks. The proposed graph-theoretic approach offers an efficient divide-and-conquer strategy using the MILP formulation on sub-networks rather than considering the whole network monolithically. In addition to the resulting improvement in computational complexity, the proposed method also aids in identifying the key reactions to be knocked-out in order to achieve the minimal cell. The efficacy of the proposed approach is demonstrated using three case studies from two organisms, Escherichia coli and Saccharomyces cerevisiae.     

网络竞赛系统框架设计与功能模块实现

随着办公自动化和远程教育的快速发展,网络竞赛系统被越来越多的学校、企事业单位使用。主要针对网络竞赛系统开发过程中,开发平台选择、系统架构设计以及各主要功能模块及其实现方法进行介绍。     

Systems-based modeling of generation variability under alternate geographic configurations of photovoltaic (PV) installations in Virginia

With increased focus on renewable energy in our modern era, it is increasingly important to understand the impact of policies on the performance and reliability of regional energy systems. This research develops a model to understand how geographic dispersion of PV installations impacts the reliability of electricity generated from the total PV network, measured by the variance of the distribution of generated electricity. Using NREL data, beta probability distributions of sunlight (kWh/m²/day) in various regions of Virginia are estimated using a fitting method that minimizes the Kolmogorov–Smirnov test statistic. A Monte Carlo simulation model is developed to measure PV electricity generation from multiple centralized and dispersed configurations over 100,000 days of probabilistic sunlight.     

Metal Core Recession and Head Stain Studies of MIG Heads Sliding against Cobalt-Doped Gamma Iron Oxide and Metal Particle Tapes

Metal-in-gap (MIG) heads are commonly used for high-density magnetic recording. Metal core recession and head stains increase the gap between the tape and the head, resulting in signal loss. In this study, accelerated sliding wear tests of Co-γFe₂O₃, and metal particle (MP) tapes against MIC heads made of three different amorphous and, nanocrystalline metals were conducted under various operating conditions. Metal core recess and propensity for head staining were measured. The degree of tape contact with a recessed core was also measured by pressing the tape against a glass slide with Cr grids and using an optical interference technique. The authors found that the core recess was about the same for all three core metals. Core recess by MP tape was larger than that, by oxide tape. The tape speed appeared to have little effect on the recess value. The authors also found that significant recess may occur during initial contouring of the head surface; however, after sliding for about 250 km, core recess reaches a steady-stale value which may be either higher or lower than the initial values. The mechanism of core recession was studied. The authors believe that core recession occurs as a consequence of the debris trapped, between the tape and the core, in addition to that caused by some tape contact. Formation of head stains was observed in all combinations. The stains fanned on the metal cores were heaviest for CoNbZr metal, followed by CoTaZr and FeTaC. Co-γFe₂O₃ tape produced a more severe stain than the MP tape. The apparent roughening of head rubbing surface observed for CoNbZr heads sliding against Co-γFe₂O₃, tape was due to the formation of stains.     

Measuring the global construction industry: improving the quality of data

In the context of a truly global market for construction, an international strategy is required to ensure that national and international statistical systems are able to provide accurate and valid information. In many parts of the world the collection of reliable national information on construction activity is not an easy task, and the measurement of comparable, cross-national data can be problematic. This paper considers possible strategies for the improvement of data collection systems in the context of user needs.     

An assessment of systems and software engineering scholars and institutions (2002-2006)

This paper summarizes a survey of publications in the field of systems and software engineering from 2002 to 2006. The survey is an ongoing, annual event that identifies the top 15 scholars and institutions over a 5-year period. The rankings are calculated based on the number of papers published in TSE, TOSEM, JSS, SPE, EMSE, IST, and Software. The top-ranked institution is Korea Advanced Institute of Science and Technology, Korea, and the top-ranked scholar is Magne Jørgensen of Simula Research Laboratory, Norway.     

辐射生物学研究发展的趋势——系统辐射生物学

辐射生物学研究已有80余年,虽然我们对辐射诱导各种生物学效应发生的基础、过程、结果以及各种影响因素已经有了较深入和广泛的认识,但随着研究的深入和应用的广泛,出现了许多用过去的辐射生物学理论和模型无法说明和解释的问题。要研究和阐明这些问题,需考虑生物系统的复杂性、反应的多样性、效应发生的时效性和生物调节反馈的多样性,从多维的角度用系统的方法进行研究。本文介绍了系统辐射生物学,研究系统辐射生物学需要考虑的主要方面,以及研究的方法和影响因素。     

Chemical stimulation techniques for geothermal wells: experiments on the three-well EGS system at Soultz-sous-Forêts,France

Rock matrix stimulation is a method of enhancing well production or injection within a broad range of challenging environments, varying from naturally fractured limestones to sandstones with complex mineralogy. A common and often successful stimulation option, matrix acidizing, utilizes acids that react and remove mineral phases restricting fluid flow. Reviewed is the technology of chemical treatments available for oil, gas and geothermal wells and the key elements and results of the chemical reservoir stimulation program at the Soultz-sous-Forêts, France, Enhanced Geothermal System Project.