Robust model for optimization of forming process for metallic bipolar plates of cleaner energy production system

Energy production systems such as proton-exchange membrane fuel cell (PEMFC) has a promising future in the cleaner energy market due to zero emissions. Rubber pad forming (RPF) process of metallic bipolar plates of PEMFCs is gaining attention among the researchers. Studies based on design of experiments have been conducted to find the crucial parameters of the forming process. These methods are based on the assumptions of the model structure, correlated residuals, etc., which can cause uncertainty in estimation ability of the model on unseen data. Therefore, the present study focuses on the design of robust models of these parameters for PEMFCs using an optimization approach of genetic programming (GP). The inputs from the experiments considered in GP are radius, the friction coefficient, the filling factor and the minimum thickness. Experiments on PEMFCs validates the performance of the GP models. Further, the relationships between the two inputs and the three outputs for PEMFCs are generated as well as the contributions of each input to each of the output. Optimization of the models generated by GP can further determine the forming quality of metallic bipolar plates of PEMFCs by an appropriate setting of the two inputs.     

Experimental and optimization of material synthesis process parameters for improving capacity of lithium‐ion battery

New methods for synthesis of active materials have been developed to improve capacity and cycle life performance of lithium‐ion batteries. Past studies have focused on routes of development of materials and new processes, which might not be economical for large‐scale production. In this regard, this study examines a widely employed carbothermal reduction technology for the synthesis of lithium‐iron phosphate (LiFePO₄/C) and investigates effects of process conditions during this synthesis on final battery performance. An experimental combined genetic programming approach is used to model the effects of crucial process conditions (sintering time, the carbon content, and the sintering temperature) on the discharge capacity of the assembled battery. Experiments are conducted to collect the discharge capacity data based on varying LiFePO₄/C synthesis conditions, and genetic programming is employed to develop a suitable functional relationship between them. The results show that the battery discharge capacity is controlled significantly by adjusting sintering temperature and carbon content, while the effect of sintering time is found to be insignificant. Further, the interaction effect of the sintering time and carbon content is much more obvious than that of the sintering time and the sintering temperature. The findings from the study pave the way for the optimum design of the synthesis process of LiFePO₄/C for a higher battery performance.     

浅谈越南三岛国家公园森林资源的影响研究

越南太原省大慈县文安乡位于三岛国家公园管理处,社区居民生活困难,收入低,所以目前森林资源侵害状况依然存在。其中,25-50岁的群人对森林资源的影响最大,50岁以上和16岁以下的群人对森林资源的影响较小。人们对森林资源的影响是:伐木,狩猎动物,收集柴火,收集蔬菜,收集竹笋、药用植物。统计结果表明,天然林中具有18种树木经常被开发利用,常用木柴12种,药用29种,食用17种。7种动物经常被猎食。这些影响使得森林结构相当大改变,生物多样性减少,森林结构破坏。造成这种情况的主要原因是人们意识不高,缺乏工作机会,缺乏耕种土地,农业生产没有满足用户的需求。因此,必要有有关部门的协调在违法森林法的处理,为人民改善物质和精神生活,教育宣传和提高执法的认识     

Secure Multi-hop Data Transmission in Cognitive Radio Networks Under Attack in the Physical Layer

Wireless Personal Communications - Cognitive radio networks (CRNs) have a shortcoming in that attackers can increase their ability to disturb secondary users (SUs). This paper focuses on jamming...     

Machine learning techniques for anti-money laundering (AML) solutions in suspicious transaction detection: a review

Money laundering has been affecting the global economy for many years. Large sums of money are laundered every year, posing a threat to the global economy and its security. Money laundering encompasses illegal activities that are used to make illegally acquired funds appear legal and legitimate. This paper aims to provide a comprehensive survey of machine learning algorithms and methods applied to detect suspicious transactions. In particular, solutions of anti-money laundering typologies, link analysis, behavioural modelling, risk scoring, anomaly detection, and geographic capability have been identified and analysed. Key steps of data preparation, data transformation, and data analytics techniques have been discussed; existing machine learning algorithms and methods described in the literature have been categorised, summarised, and compared. Finally, what techniques were lacking or under-addressed in the existing research has been elaborated with the purpose of pinpointing future research directions.     

基于时间常数的核电厂主循环泵惰转模型开发与验证

在核电厂初步设计阶段,针对反应堆进行的工况设计和安全分析均需要泵的惰转模型提供输入。现有泵的惰转模型几乎都需要已知泵的设计参数和管路系统阻力特性,但在电厂初步设计阶段,泵的详细结构设计尚未开展,管路阻力特性也难以获取。针对上述问题,提出了两种基于时间常数的主泵惰转特性曲线计算模型,并采用核电厂主循环泵的惰转试验数据进行了对比验证。分析结果表明,模型A在高转速时与试验值吻合较好,低转速时偏差较大,而模型B在整个惰转过程中与试验值均较接近,可用于核电厂的工况设计和安全分析。     

Interval functional observers for time-delay systems with additive disturbances

This article considers the design of interval functional observers to estimate a linear function of the state vector of time-delay systems subject to both input and output additive disturbances. Two novel functional observers are proposed and designed such that they bound the set of all admissible values of a linear function of the state vector at each instant of time. By contrast to interval observers currently available in the literature, both observers proposed in this article utilize multiple delayed output measurement and have a more general structure. This trade-off feature overcomes some drawbacks in previous work and enables interval functional observers to be designed for a wider class of time-delay systems. Conditions for the existence of interval functional observers are derived and an effective design algorithm for computing unknown observer matrices is provided. Two illustrative examples are given to show the advantages and effectiveness of our design method.     

Design response to rising sea levels in the Maldives: A study into aquatic architecture

Climate change and rising sea levels present immediate threats to humanity. However, the global catastrophe fails to generate sufficient action. Subject to total submergence within 80 years, this study undertakes an iterative design process seeking sustainable adaptation strategies for the coastal island nation of the Maldives, specifically, Malé, its capital, which exists under a “state of alert” by order of government. Research methods include literature reviews, site analysis, mapping, and iterative design processes to develop an implementation framework strategy. Infrastructure concepts are presented as speculative images with context-specific spatial relationships and functions. Concepts do not intend to represent a conclusive prototype, rather, an ideation—a solution-based discourse among key audiences highlighting the need to act decisively and adaptively.     

Live-Cell Copper-Induced Fluorescence Quenching of the Flavin-Binding Fluorescent Protein CreiLOV

CreiLOV is a flavin-binding fluorescent protein derived from the blue-light photoreceptor protein family that contains light-oxygen-voltage (LOV) sensing domains. Flavin-binding fluorescent proteins represent a promising foundation for new fluorescent reporters and biosensors that can address limitations of the well-established green fluorescent protein (GFP) family. Flavin-binding fluorescent proteins are smaller than GFPs, are stable over a wider pH range, offer rapid chromophore incorporation, and are oxygen-independent so can be applied to live anaerobic organisms. Among the flavin-binding fluorescent proteins, CreiLOV has a high quantum yield and excellent photophysical properties, making it promising for cellular applications. Here, we investigated the suitability of CreiLOV as an intensity- and fluorescence-lifetime-based metal sensor. CreiLOV selectively binds copper(II) over other biologically relevant metals with low-micromolar affinity, resulting in fluorescence quenching and a decrease in the fluorescence lifetime that can be observed in cuvettes and live bacterial cells.