Application of Unavailability Analysis Method to Determining Periodic Test Procedure of Emergency Core Cooling System

The test interval and the test procedure are the main factors that are related to the reliability of the emergency core cooling system in a nuclear power plant. A method is proposed to specify the allowable ranges of the test intervals for the minimal cut sets in the emergency core cooling system; lower and upper limits of test intervals are selected to minimize unavailability and to assure the unavailability goal respectively. A method is also proposed to determine test procedure. All patterns of test procedure for the emergency core cooling system are generated in the allowable ranges of test intervals, and the test procedure is selected to maximize the index {minus log. of (unavailability over unavailability goal), all devided by man-hours} for the purpose of both reliability increase and man-hours decrease.     

Framed slotted ALOHA with grouping tactic and binary selection for anti-collision in RFID systems

9%-16.3% compared to other ALOHA-based tag anti-collision algorithms when the number of tags is 1 000.     

Identification and classification of dynamic event tree scenarios via possibilistic clustering: Application to a steam generator tube rupture event

This paper illustrates a method to identify and classify scenarios generated in a dynamic event tree (DET) analysis. Identification and classification are carried out by means of an evolutionary possibilistic fuzzy C-means clustering algorithm which takes into account not only the final system states but also the timing of the events and the process evolution. An application is considered with regards to the scenarios generated following a steam generator tube rupture in a nuclear power plant. The scenarios are generated by the accident dynamic simulator (ADS), coupled to a RELAP code that simulates the thermo-hydraulic behavior of the plant and to an operators’ crew model, which simulates their cognitive and procedures-guided responses.A set of 60 scenarios has been generated by the ADS DET tool. The classification approach has grouped the 60 scenarios into 4 classes of dominant scenarios, one of which was not anticipated a priori but was “discovered” by the classifier. The proposed approach may be considered as a first effort towards the application of identification and classification approaches to scenarios post-processing for real-scale dynamic safety assessments.     

Interaction analysis and geometric interconnection decoupling for networks of process systems

The effects of interactions between nonlinear subprocesses on the stabilizability of plantwide systems via the concept of dissipative systems are studied. Conditions for which controlled variables of each interconnected subprocess can be driven to and maintained at their desired values are established through the application of interconnection decoupling techniques. The resulting decoupling feedback law encodes the interaction effects between subprocesses and determines the required information structure for achieving desired control performance using distributed control laws. The proposed constructive approach leads to new criteria for the selection of manipulated and controlled variables that guarantee plantwide stability. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2795–2809, 2013     

Container loading with multi-drop constraints

In this paper, an algorithm for the container-loading problem (CLP) with multi-drop constraints is presented. When adding multi-drop constraints, we demand that the relevant boxes must be available, without rearranging others, when each drop-off point is reached. To make the solutions feasible in the real world, it is further demanded that all boxes are placed in a feasible manner with respect to load-bearing strength and with proper support from below. This makes it possible to load consignments originating from builder merchants. A heuristic based on a tree search framework is proposed. It uses greedy solutions to evaluate each choice taken. To make the framework more generic, a dynamic breadth is proposed. Based on problem characteristics and the time limit imposed, it will choose the breadth of the tree, making sure that the time is utilised most profitably. The algorithm is tested on new real-world data from a Danish company distributing construction products. For the solutions to these problems to be feasible in a real-world setting, both multi-drop and load-bearing strength constraints are essential. The obtained results show that the proposed model and algorithm are able to solve the new real-world problems in fractions of a second. Furthermore, results obtained on benchmark problems indicate that the algorithm performs comparably with other more specialised methods.     

A novel tree‐shaped antenna with wideband and end‐fire properties designed by competitive algorithm of simulating natural tree growth

This article presents a novel tree‐shaped antenna with wideband and end‐fire properties designed by the Competitive Algorithm of Simulating Natural Tree Growth. The antenna has an impedance bandwidth of 27.2% for S11 < ?10dB, maintains end‐fire radiation pattern and achieves a high gain over the entire frequency band from 5.4 GHz to 7.1 GHz. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.     

Profiling selected phytochemicals and nutrients in different tissues of the multipurpose tree Moringa oleifera L., grown in Ghana

The purpose of this new study was to determine the types and levels of major phytochemicals (non-nutrients) and nutrients in the different tissues from vegetative and flowering Moringa oleifera L. an important multipurpose crop. Rhamnose and acetyl-rhamnose-substituted glucosinolates were found in all of the M. oleifera tissues with different profiles depending on the tissue. In addition the tissues of M. oleifera had a relatively complex flavonoid profile consisting of glucosides, rutinosides, malonylglucosides and traces of acetylglucosides of kaempferol, quercetin and isorhamnetin. Fatty acid profiling of the different tissues showed that leaves were rich in palmitic (16:0) and linolenic (18:3) acid whereas seeds were predominated by oleic acid (18:1). Roots were rich in palmitic and oleic acid, whereas stems and twigs predominately contained palmitic acid. Potassium, magnesium and calcium were the predominant minerals in all of the tissues. Low levels of selenium were detected only in whole seeds.     

Japan Flavour and Fragrance Materials Association’s (JFFMA) safety assessment of food-flavouring substances uniquely used in Japan that belong to the class of aliphatic primary alcohols,aldehydes, carboxylic acids,acetals and esters containing additional oxygenated functional groups

ABSTRACT

We performed a safety evaluation using the procedure devised by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) of the following four flavouring substances that belong to the class of ‘aliphatic primary alcohols, aldehydes, carboxylic acids, acetals, and esters containing additional oxygenated functional groups’ and are uniquely used in Japan: butyl butyrylacetate, ethyl 2-hydroxy-4-methylpentanoate, 3-hydroxyhexanoic acid and methyl hydroxyacetate. Although no genotoxicity study data were found in the published literature, none of the four substances had chemical structural alerts predicting genotoxicity. All four substances were categorised as class I by using Cramer’s classification. The estimated daily intake of each of the four substances was determined to be 0.007–2.9 μg/person/day by using the maximised survey-derived intake method and based on the annual production data in Japan in 2001, 2005 and 2010, and was determined to be 0.250–600.0 μg/person/day by using the single-portion exposure technique and based on average-use levels in standard portion sizes of flavoured foods. Both of these estimated daily intake ranges were below the threshold of toxicological concern for class I substances, which is 1800 μg/person/day. Although no information from in vitro and in vivo toxicity studies for the four substances was available, these substances were judged to raise no safety concerns at the current levels of intake.     

空气洁净度测试中的若干问题

分析空气洁净度测试中最小采样量的理论，给出最小采样量计算公式的推演过程，以及讨论在检测粒径的选取、空气洁净度级别的确定中存在的问题。     

The structural and radiative consistency of three-dimensional tree reconstructions from terrestrial lidar

A novel methodology is proposed to reconstruct 3D tree architectures from terrestrial LiDAR (TLiDAR) scans. The methodology is robust and relatively insensitive to wind- and occlusion-induced artefacts in the 3D TLiDAR point clouds. A quantitative evaluation of structural attributes, like the vertical foliage and wood area profiles, as well as the shoot orientation distribution, was performed. Due to the difficulties of acquiring reliable and accurate estimates of these parameters in the field, an original evaluation approach was chosen that reproduces the TLiDAR scanning and subsequent tree reconstruction process in a virtual environment. In a second step the reconstructed tree models were ingested in a validated 3D radiative transfer model to simulate both their reflectance signatures (observable by space borne instruments) and directional transmission properties (measurable during field campaigns) under various spectral, illumination and tree density scenarios. The results of these evaluations confirm the appropriateness of the proposed tree reconstruction model for the generation of structurally and radiatively faithful copies of existing plant and canopy architectures.