Normalised availability importance measures for complex systems

Once the performance characteristics of a system have been determined, engineers are often faced with the task of identifying the critical components. The objective of this identification is to prioritise improvements in the systems and the efforts to bring these about in the areas that will have the most effect on the system’s performance. Availability is an important metric, used to assess the performance of complex systems. Having the availability importance measure (AIM), which determines the importance of items regarding the availability of the system, can help designers and managers to improve performance and minimise the life cost of the system. This paper has developed an AIM for complex systems. Thereafter, the application of the developed importance measure is illustrated by a case study.     

HSDN‐GRA: A hybrid software‐defined networking‐based geographic routing protocol with multi‐agent approach

We propose in this paper a Hybrid Software‐Defined Networking‐based Geographical Routing Protocol (HSDN‐GRA) with a clustering approach. It takes into account three different criteria to select the best relay to send data: (1) the contact duration between vehicles, (2) the available load of each vehicle, (3) and the log of encountered communication errors embedded in each cluster head. The multi‐criteria strategy allows the selection of the most reliable vehicles by avoiding communication problems and ensuring connection availability. Once the hybrid control plane has found out the next eligible neighbor, the data plane will be in charge of dividing and sending data. To validate our approach, HSDN‐GRA has been modeled and implemented in JADE, a multi‐agent platform, to be compared to other multi‐agent based protocols. Simulation results show that HSDN‐GRA achieves good performance with respect to the average routing overhead, the packet drop rate, and the throughput.     

A method of assessing essential amino acid availability from microbial and ruminally undegraded protein in lactating dairy cows

The objective of this study was to extend a stable isotope-based assessment of AA absorption from rumen-degradable protein (RDP) sources to include determination of essential AA (EAA) availability from microbial protein (MCP). To demonstrate the technique, a study using a 2 × 2 factorial arrangement of treatments applied in a repeated 4 × 4 Latin square design was undertaken. Factors were high and low rumen-degradable protein and high and low starch. Twelve lactating cows were blocked into 3 groups according to days in milk and randomly assigned to the 4 treatment sequences. Each period was 14 d in length with 10 d of adaption followed by 4 d of ruminal infusions of ¹⁵N-labeled ammonium sulfate. On the last day of each period, a ¹³C-labeled AA mixture was infused into the jugular vein over a 6-h period to assess total AA entry. Rumen, blood, urine, and milk samples were collected during the infusions. Ruminal bacteria and blood samples were assessed for AA enrichment. Total plasma AA absorption rates were derived for 6 EAA from plasma ¹³C AA enrichment. Absorption of 6 EAA from MCP was calculated from total AA absorption based on ¹⁵N enrichment in blood and rumen bacteria. Essential AA absorption rates from total protein, MCP, and rumen-undegradable protein were derived with standard errors of the mean of 6, 14, and 14%, respectively. An average of 45% of absorbed EAA were from MCP, which varied among 6 EAA and was interactively affected by starch and RDP in diets. Microbial AA availability measured by isotope dilution method increased with the high RDP diets and was unaffected by starch level, except for Met, which decreased with high starch. Microbial protein outflow, estimated from urinary purine derivatives, increased with RDP and was not significantly affected by starch. This was consistent with measurements from the isotope dilution method. Total AA absorption rates measured from isotope dilution were similar to estimates from CNCPS (v. 6.55), but a lower proportion of absorbed AA was derived from MCP for the former method. Compared with the isotope and CNCPS estimates, the Fleming model underestimated microbial EAA and total EAA availability. An average of 58% of the absorbed EAA was converted into milk, which varied among individual AA and was interactively affected by starch and RDP in diets. The isotope dilution approach is advantageous because it provides estimates of EAA availability for individual EAA from rumen-undegradable protein and MCP directly with fewer errors of measurement than can be achieved with intestinal disappearance methods.     

GIS method for characterizing fire flow capacity

There are numerous methods currently used to calculate required water flow rates for sprinklered and non-sprinklered buildings. The aim of this study is provide a flexible automated procedure for indentifying locations lacking adequate fire flow. To accomplish this objective, this research uses a GIS procedure to determine the spatial relationships between fire hydrants and historical fire incidences, and integrates the recommended hydrant spacing and building type specifications from the International Fire Code. This method was tested in two communities in eastcentral Michigan, USA. The results indicate an ability to define clusters of fires, determine the availability of hydrants, and assess the suitability of the available fire flow, including areas of potential extra capacity. Using these same data, additional GIS analyses can optimize hydrant location, ascertain the frequencies of different categories of fires, and identify the patterns of building types prone to fires.     

Physicochemical and environmental properties of arsenic sulfide sludge from copper and lead−zinc smelter

Physicochemical properties of arsenic sulfide sludge (ASS) from copper smelter (ASS-I) and lead−zinc smelter (ASS-II) were examined by XRD, Raman spectroscopy, SEM−EDS, TG−DTA, XPS and chemical phase analysis method. The toxicity characteristic leaching procedure (TCLP), Chinese standard leaching tests (CSLT), three-stage sequential extraction procedure (BCR) and batch leaching experiments (BLE) were used to investigate the environmental stability. The ASSs from different smelters had obviously different physicochemical and environmental properties. The phase composition and micrograph analysis indicate that ASS-I mainly consists of super refined flocculent particles including amorphous arsenic sulfide adhered with amorphous sulfur and that ASS-II mainly consists of amorphous arsenic sulfide. The valence state of arsenic in both sludges is trivalent, but the valence composition of sulfur is quite different. The ASSs have thermal instability properties. The results of TCLP and CSLT indicate that the concentrations of As and Pd in the leaching solution exceed the standard limits. More than 5% and 90% of arsenic are in the form of acid soluble and oxidizable fractions, respectively, which explains the high arsenic leaching toxicity and environmental activity of ASS. This research provides comprehensive information for the disposal of ASS from copper and lead−zinc smelter.     

基于内隐测量的APP交互流程可用性评估方法

目的 研究内隐测量用于交互流程评估的普遍方法，选取适合的参考指标建立评估标准，旨在提出一套完整且通用的评估策略。方法 以带有拍摄功能的宠物社交类APP为载体，提出两种不同的交互流程，建立交互原型，并提取两套原型中差异较大的流程进行对比实验，采用眼动仪收集被测的无意识行为，依据首次注视时间、兴趣区域注视率，注视点图等指标分析实验数据，并与外显测量结果相结合，衡量用户操作情况以及APP的交互性能。结果 根据实验和数据分析，得出以拍摄界面为主页是更适合宠物社交APP的交互方式。结论 内隐测量评估作为一种新兴的产品可用性评估方式，不仅在交互界面设计评估上得到了广泛的应用，还可作为产品交互流程的评估方法，并具有深度挖掘的意义。     

Availability growth models and verification of power equipment

The general availability growth models for large scale complicated repairable system such as electric generating units, power station auxiliaries, and transmission and distribution installations are presented. The calculation formulas for the maintenance coefficient, mathematical expressions for general availability growth models, ways for estimating, and fitting on checking the parameters of the model are introduced. Availability growth models for electric generating units, power station auxiliaries, and transmission and distribution installations are given together with verification examples for availability growth models of 320–1000 MW nuclear power units and 1000 MW thermal power units, 200–1000 MW power station auxiliaries, and 220–500 kV transmission and distribution installations. The verification results for operation availability data show that the maintenance coefficients for electric generating units, power station auxiliaries, transmission and distribution installations conform to the power function, and general availability growth models conform to rules of availability growth tendency of power equipment.