Service level management with agent technology

This paper outlines a generic evaluation methodology for multimedia and real time applications. It concentrates on the application layer and the service aspect. Principles of software evaluation for quality assessment and measurement for networked services and distributed applications are used to present a specific method for measuring important characteristics. The method and the measurement procedure allow comparison of the actual characteristics of service quality with the required characteristics and thresholds. The proof of concepts will be made by the implementation of quality measurement agents following the approach outlined in this paper. Our approach of performing service level management (SLM) with agent technology is distributed, slim, minimizable to the maximum, independent in its methodology and offers comparable, objective results.     

On the number of term orders

By an admissible order on a finite subsetQ of ⁿ we mean the restriction toQ of a linear order on ⁿ compatible with the group structure of ⁿ and such that ⁿ is contained in the positive cone of the order. We first derive upper and lower bounds on the number of admissible orders on a given setQ in terms of the dimensionn and the cardinality ofQ. Better estimates are possible if the setQ enjoys symmetry properties and in the case whereQ is a discrete hyperbox of the form In the latter case, we also give asymptotic results as d _k for fixedn. We finally present algorithms which compute the set of admissible orders that extend a given binary relation onQ and their number. The algorithms are useful in connection with the construction of universal Gröbner bases.AMS Classification: primary 06F20 secondary 06-04, 11N25     

Modeling broad-scale patterns of avian species richness across the Midwestern United States with measures of satellite image texture

Avian biodiversity is threatened, and in order to prioritize limited conservation resources and conduct effective conservation planning a better understanding of avian species richness patterns is needed. The use of image texture measures, as a proxy for the spatial structure of land cover and vegetation, has proven useful in explaining patterns of avian abundance and species richness. However, prior studies that modeled habitat with texture measures were conducted over small geographical extents and typically focused on a single habitat type. Our goal was to evaluate the performance of texture measures over broad spatial extents and across multiple habitat types with varying levels of vertical habitat structure. We calculated a suite of texture measures from 114 Landsat images over a study area of 1,498,000 km² in the Midwestern United States, which included habitats ranging from grassland to forest. Avian species richness was modeled for several functional guilds as a function of image texture. We subsequently compared the explanatory power of texture-only models with models fitted using landscape composition metrics derived from the National Land Cover Dataset, as well as models fitted using both texture and composition metrics. Measures of image texture were effective in modeling spatial patterns of avian species richness in multiple habitat types, explaining up to 51% of the variability in species richness of permanent resident birds. In comparison, landscape composition metrics explained up to 56% of the variability in permanent resident species richness. In the most heavily forested ecoregion, texture-measures outperformed landscape metrics, and the two types of measurements were complementary in multivariate models. However, in two out of three ecoregions examined, landscape composition metrics consistently performed slightly better than texture measures, and the variance explained by the two types of measures overlapped considerably. These results show that image texture measures derived from satellite imagery can be an important tool for modeling patterns of avian species richness at broad spatial extents, and thus assist in conservation planning. However, texture measures were slightly inferior to landscape composition metrics in about three-fourths of our models. Therefore texture measures are best considered in conjunction with landscape metrics (if available) and are best used when they show explanatory ability that is complementarity to landscape metrics.     

Vc: A C++ library for explicit vectorization

It is an established trend that CPU development takes advantage of Moore's Law to improve in parallelism much more than in scalar execution speed. This results in higher hardware thread counts (MIMD) and improved vector units (SIMD), of which the MIMD developments have received the focus of library research and development in recent years. To make use of the latest hardware improvements, SIMD must receive a stronger focus of API research and development because the computational power can no longer be neglected and often auto‐vectorizing compilers cannot generate the necessary SIMD code, as will be shown in this paper. Nowadays, the SIMD capabilities are sufficiently significant to warrant vectorization of algorithms requiring more conditional execution than was originally expected for Streaming SIMD Extension to handle. The Vc library ( http://compeng.uni‐frankfurt.de/?vc ) was designed to support developers in the creation of portable vectorized code. Its capabilities and performance have been thoroughly tested. Vc provides portability of the source code, allowing full utilization of the hardware's SIMD capabilities, without introducing any overhead. Copyright © 2011 John Wiley & Sons, Ltd.     

RH装置的多种设计概念

西马克美马克公司近些年来不断致力于改进RH装置的装备水平和冶金技术并取得了丰富的经验,其处理的钢水可以满足用户对在最短的处理周期及最小的工艺成本下获得极低碳或极低氢含量的要求.RH装置的形式可从单真空室到双工位双真空室快速更换等多种.本文以冶金和经济的角度详细地阐述了西马克美马克公司RH装置的概念和应用实践.西马克美马克公司在中国攀枝花钢铁集团公司最新投产的LF和RH装置就是我们二次精炼现代化工艺概念的代表.与西马克美马克公司的工艺自动化2级相似,其可以得到精确的成分,纯净的和最低的氢含量.工艺模型在线的修改方式也将有所介绍.     

Streamlining the Development Approval Process in a Post–Level of Service Los Angeles

Problem, research strategy, and findings: Local governments across the United States have for decades relied on the autocentric level of service (LOS) metric to analyze and impose exactions for the transportation impacts of land use developments. In California, LOS has dominated transportation impact analysis under the state’s project-level environmental review law. In that role, LOS has exacerbated the state’s notoriously tortuous development approval processes, particularly in urban areas. But LOS is on its way out. The state recently replaced LOS with vehicle miles traveled (VMT) as the primary measure—and basis for mitigation—of transportation impacts under the California Environmental Quality Act. Local governments must make the switch by July 1, 2020. We use a historical counterfactual approach to assess how replacing LOS with VMT could have affected the approval process for 153 land development projects over 16?years in the city of Los Angeles. We find that most projects could have benefited from at least some environmental review streamlining under the VMT-based framework recommended by the state, including more than 75% of residential-containing projects.

Takeaway for practice: Our results suggest that swapping LOS for VMT could reduce the environmental review burden for development in low-VMT urban areas and provide at least some of the approval process streamlining necessary to increase housing production in California. Similar impacts from an LOS-to-VMT switch could also potentially accrue outside of California under the right conditions, but more research is needed.     

Looking out to look in: inspiration from social sciences for construction management research

In reaction to the recent call for critical debate in the field of construction management research, I argue that we should embrace the richness of adjacent fields of study in order to dynamically develop our own and face the plethora of contemporary societal challenges that exist in our industry. I introduce the concepts of other-than-rational thinking in decision-making and multiplicity in management responses as examples of inspirational sources from social sciences that would contribute to truly understanding the driving forces of construction management processes. I connect these concepts to contemporary studies in construction management and share my experiences with several positive collaborative approaches in conducting construction management research.     

Effect of Post-weld Heat Treatment on Microstructure and Mechanical Properties of Laser Beam Welded TiAl-based Alloy

Post-weld heat treatment is carried out on the laser beam welded γ-TiAl-based alloy Ti-48Al-1Cr-1.5Nb-1Mn-0.2Si-0.5B (at. pct). The macro/microstructure and mechanical properties of both as-welded and heat-treated specimens are investigated by radiography, SEM, and tensile tests. Moreover, high energy synchrotron X-ray diffraction is performed to measure the residual stresses and evaluate the microstructure evolution. It is found that the residual stresses are distributed in a three-peak shape in the region of the weld zone and heat-affected zone of the as-welded specimen due to the microstructural transformation and heat softening. The residual stresses are largely relieved after the heat treatment. The heat-treated specimens have a near fully lamellar microstructure and show balanced mechanical properties of strength and ductility. The diffraction shows that the phase transformation from α ₂ to γ takes place under tensile load at 1023 K (750 °C), and the grain size and lamellar spacing are refined in the weld zone. Finally, the fracture mechanisms are found to be controlled by the local stress concentration-induced strain misfit between α ₂ and γ phases in the near γ grains and delamination and debonding in the lamellae. Boride ribbons of 5 μm in the near fully lamellar microstructure are found not to be detrimental to the tensile properties.     

On the importance of specific interface area in clay nanocomposites of PMMA filled with synthetic nano-mica

In clay nanocomposites, the specific interface area is the key factor determining potential improvements of properties. Nevertheless, in most systematic studies of nanocomposites little emphasis is put on assuring and characterizing dispersion quality. To probe the influence of dispersion quality, we compare nanocomposites filled with two layered silicates which were made by melt compounding and solution blending, respectively. Poly(methyl methacrylate) (PMMA) is chosen here as a thermoplastic model matrix which was compounded with a synthetic nano-mica (O-hect) and commercial Bentone with typical diameters of 5–7 μm and <300 nm, respectively.     

Surge arresters for insulation coordination in UHV power systems—related problems and solutions

Surge arresters play an important role in the insulation coordination of ultra high-voltage (UHV) electric power systems. In this contribution the requirements on the surge arresters are discussed in comparison with those in conventional applications, and how surge arrester standards are being changed to cover these special requirements.