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Fuzzy-based risk prioritization for a hydrogen refueling facility in Malaysia

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第8期14卷 834-834页

作者： Hue-yee Chong Mahidzal Dahari Hwa-jen Yap Ying-tai Loong Department of Mechanical Engineering Faculty of Engineering University Malaya Kuala Lumpur Malaysia

Hydrogen is starting to be mentioned as an alternative fuel to replace the fossil fuel in future transportation applications due to its characteristics of zero greenhouse gas emission and high energy efficiency. Before hydrogen fuel and its facilities can be introduced to the public, relevant safety issues and its hazards must be assessed in order to avoid any chance of injury or loss. While a traditional risk assessment has difficulty in prioritizing the risk of failure modes, this paper proposes a new fuzzy-based risk evaluation technique which uses fuzzy value to prioritize the risk of various scenarios. In this study, the final risk of each failure modes was prioritized by using the MATLAB fuzzy logic tool box with a combination of two assessments. The first assessment was concerned with the criteria which affected the actual probability of *** assessment considered the availability of the standard that was applied to prevent the likelihood of the scenario occurring. On the other hand, the second assessment was focused on evaluating the consequence of the failure by taking into account the availability of detection and the complexity of the failure rather than only the severity of the scenarios. A total of 87 failure scenarios were identified using failure modes and effect analysis(FMEA) procedures on hydrogen refueling station models. Fuzzy-based assessments were performed through risk prioritizing various failure scenarios with a fuzzy value(0 to 1) and risk level(low, medium, and high)while a traditional risk assessment approach presented the risks only in forms of level(low, medium, and/or high). Availability of the fuzzy value enabled further prioritizing on the risk results that fell in the same level of risk. This study concluded that fuzzy-based risk evaluation is able to further prioritize the decisions when compared with a traditional risk assessment method.

关键词：风险评估方法模糊值加氢站马来西亚设施优先级模糊逻辑工具箱故障模式

Associating liver partition and portal vein ligation for staged hepatectomy： the current role and development

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Hepatobiliary & Pancreatic Diseases International 2017年第1期16卷 17-26页

作者： Wan yee Lau Eric CH Lai Stephanie HY Lau Faculty of Medicine The Chinese University of Hong Kong Shatin New Territories Department of Surgery Pamela Youde Nethersole Eastern Hospital Department of Surgery Queen Elizabeth Hospital Hong Kong China

BACKGROUND： Associating liver partition and portal vein ligation for staged hepatectomy （ALPPS） has recently been developed to induce rapid liver hypertrophy and reduce posthepatectomy liver failure in patients with insufficient future liver remnant （FLR）. ALPPS is still considered to be in an early developmental phase because surgical indications and techniques have not been standardized. This article aimed to review the current role and future developments of ALPPS. DATA SOURCES： Studies were identified by searching MED- LINE and PubMed for articles from January 2007 to October 2016 using the keywords ＂associating liver partition and portal vein ligation for staged hepatectomy＂ and ＂ALPPS＂ Addi- tional papers were identified by a manual search of references from key articles. RESULTS： ALPPS induces more hypertrophy of the FLR in less time than portal vein embolization or portal vein ligation. The benefits of ALPPS include rapid hypertrophy 47%-110% of the liver over a median of 6-16.4 days, and 95%-100% com- pletion rate of the second stage of ALPPS. The main criticisms of ALPPS are centered on its high morbidity and mortality rates. Morbidity rates after ALPPS have been reported to be 15.3%-100%, with ≥ the Clavien-Dindo grade III morbidity of 13.6%-44%. Mortality rates have been reported to be 0%-29%. The important questions to ask even if oncologic long-term results are acceptable are： whether the gain in quality and quantity of life can be off balance by the substantial risks of morbidity and mortality, and whether stimulation of rapid liver hypertrophy also accelerates rapid tumor progression and spread. Up till now, the documentations of the ALPPS procedure come mainly from case series, and most of these series include heterogeneous groups of malignancies. The numbers are also too small to separately evaluate survival for different tumor etiologies. CONCLUSIONS： Currently, knowledge on ALPPS is limited, and prospective randomized studies are lacking. From th

关键词： associating liver partition and portal vein ligation for staged hepatectomy portal vein embolization laparoscopy colorectal liver metastases hepatocellular carcinoma

SALAK法提升华裔小学生马来语书写教学质量的研究

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SALAK法提升华裔小学生马来语书写教学质量的研究

作者： CHAI yee ling（蔡依玲）华中师范大学

学位级别：硕士

马来语既是马来西亚的国语,也是官方语言,无论是中学还是小学,马来语都是学生必学的科目。然而,不管是眼前的考试,还是未来的升学或就业,学习马来语一直是华裔小学生面对的难题。本研究主要分成三个部分。第一部将解释并探讨SALAK教学... 详细信息

马来语既是马来西亚的国语,也是官方语言,无论是中学还是小学,马来语都是学生必学的科目。然而,不管是眼前的考试,还是未来的升学或就业,学习马来语一直是华裔小学生面对的难题。本研究主要分成三个部分。第一部将解释并探讨SALAK教学法如何提升华裔小学生在马来语书写方面的能力。在现有制度下,马来西亚并没有太多关于如何提升马来语书写能力教学的华语版论文、研究报告甚至是参考资料。而笔者选择此研究题目主要是希望能通过此研究而提升自身的教学质量,从而让其他执教中的导师们受惠。在文献综述里,笔者主要将国内外与如何提高书写能力书写有关的论文和期刊等做一个综述。研究方面,则选择了行动研究方法,这包括了文献探讨、资料收集来作为研究的根据,并对尚任职的华小校长、老师、补习老师进行访问,以从不同的层面,不同的角度,用更客观的观点来分析现在的华裔小学生所面对的马来语书写问题,进而想出适当的方法来提升他们的马来语书写能力。第二个部分则是对华裔小学生的马来语书写教学的问题和所存在的问题的归因做一个现状分析。再从华裔小学生的书写表现以及教师教学表现方面来展现出SALAK法的实践成效。第三部分为提升华裔小学生马来语书写教学质量的四个建议。其一,加强书写课的内容与现实生活的联系;其二,教学内容方式要更加灵活多变;其三,善于借助阅读提升书写的能力及技巧;其四,激活华裔小学生对马来语书写的兴趣。虽然马来西亚的马来语书写教学法的研究不少,但是仍以马来语为媒介语的居多,而以华语为媒介语的几乎为零。此研究除了更针对性,更深入的对华裔小学生所面对的问题提出建议,甚而也包括将现有最新的课程纲框架的问题和难题也纳入此研究的范围,并提出合时宜的建议,务确所总结的论点是于时并进的。

关键词： SALAK法马来语书写教学质量

Effects of root morphology and anatomy on cadmium uptake and translocation in rice(Oryza sativa L.)

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Journal of Environmental Sciences 2019年第1期31卷 296-306页

作者： Lu Huang Wai Chin Li Nora Fung yee Tam Zhihong Ye School of Life Sciences Sun Yat-sen University Department of Science and Environmental Studies The Education University of Hong Kong State Key Laboratory in Marine Pollution and Department of Chemistry City University of Hong Kong

A clear description of the certain mechanisms of cadmium(Cd) uptake and translocation in rice(Oryza sativa L.) may help to reduce Cd accumulation in rice grain. Hydroponic experiments were carried out to determine the effects of cultivation conditions(aerated and stagnant) on the uptake, translocation and subcellular distribution of Cd in relation to the morphology and anatomy of roots in two rice genotypes with different Cd accumulations in grains. Marked differences in morphology and anatomy were observed between these two genotypes under different cultivation conditions. Genotypes with low Cd accumulation in grains tended to develop fewer root tips per root surface area, larger root porosity and more mature apoplastic barriers. The stagnant cultivation condition decreased the number of root tips per root surface area but increased root porosity and accelerated apoplastic barrier formation in root *** Cd uptake studies revealed that rice plants with fewer number of root tips per root surface area reduced root Cd uptake ability, while mature apoplastic barriers increased root Cd retention in cell walls and the symplast. Thus, the fewer number of root tips per root surface area and the earlier formation of mature apoplastic barriers led to lower Cd uptake and translocation. The results indicated that the morphology and anatomy of roots could play important roles in Cd uptake and translocation in rice, and could be influenced by both genotype and cultivation conditions. The present results would be useful in screening and planting rice plants with low Cd accumulation.

关键词： Apoplastic barriers Cadmium Rice Root morphology

Size prediction of κ-carrageenan droplets formed in co-flowing immiscible liquid

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Particuology 2011年第6期9卷 637-643页

作者： Jun-yee Leong Tek-Kaun Lim Ravindra Pogaku Eng-Seng Chan Centre of Materials and Minerals School of Engineering and Information Technology Universiti Malaysia Sabah School of Engineering Monash University

The formation of K-carrageenan droplets in channel emulsification was experimentally investigated. The dispersed phase was vertically injected into co-flowing immiscible palm oil in the direction of gravity. This study focused on predicting K-carrageenan drop size using force balance analysis. The force balance model considers the interracial tension to be the solitary attaching force, while a combination of the drag force from the co-flowing palm oil and the body force of the extruding K-carrageenan liquid act as the detaching forces. The conventional model gave poor predictions for droplet size, with an average relative deviation of 23%. This large deviation could be attributed to necking phenomena and an underestimation of the drag force generated on the shear-thinning K-carrageenan solution. By incorporating correction factors, the average relative deviation of the force balance model dronned to 4%.

关键词： K-Carrageenan Droplet Channel emulsification Co-flowing Dripping Bioencapsulation

Polyvinylpyrrolidone-based bioink:influence of bioink properties on printing performance and cell proliferation during inkjet-based bioprinting

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Bio-Design and Manufacturing 2023年第6期6卷 676-690页

作者： Wei Long Ng Xi Huang Viktor Shkolnikov Ratima Suntornnond Wai yee Yeong HP-NTU Digital Manufacturing Corporate Lab Nanyang Technological University(NTU)Singapore 637460Singapore Singapore Centre for 3D Printing(SC3DP) School of Mechanical and Aerospace EngineeringNanyang Technological University(NTU)Singapore 639798Singapore HP Inc. Palo AltoCA 94304USA

Among the different bioprinting techniques,the drop-on-demand(DOD)jetting-based bioprinting approach facilitates contactless deposition of pico/nanoliter droplets ofmaterials and cells for optimal cell–matrix and cell–cell *** bioinks play a critical role in the bioprinting process,there is a poor understanding of the influence of bioink properties on printing performance(such as filament elongation,formation of satellite droplets,and droplet splashing)and cell health(cell viability and proliferation)during the DOD jetting-based bioprinting *** inert polyvinylpyrrolidone(PVP360,molecular weight=360 kDa)polymerwas used in this study to manipulate the physical properties of the bioinks and investigate the influence of bioink properties on printing performance and cell *** experimental results showed that a higher bioink viscoelasticity helps to stabilize droplet filaments before rupturing from the nozzle *** highly stretched droplet filament resulted in the formation of highly aligned“satellite droplets,”which minimized the displacement of the satellite droplets away from the predefined ***,a significant increase in the bioink viscosity facilitated droplet deposition on the wetted substrate surface in the absence of splashing and significantly improved the accuracy of the deposited main *** analysis showed that cell-laden bioinks with higher viscosity exhibited higher measured average cell viability(%),as the presence of polymer within the printed droplets provides an additional cushioning effect(higher energy dissipation)for the encapsulated cells during droplet impact on the substrate surface,improves the measured average cell viability even at higher droplet impact velocity and retains the proliferation capability of the printed *** the influence of bioink properties(e.g.,bioink viscoelasticity and viscosity)on printing performance and cell proliferation is important for the formulation

关键词： Biofabrication 3D bioprinting Drop-on-demand bioprinting Bioink properties Polyvinylpyrrolidone

Graphical password： prevent shoulder-surfing attack using digraph substitution rules

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Frontiers of Computer Science 2017年第6期11卷 1098-1108页

作者： Lip yee POR Chin Soon KU Amanul ISLAM Tan Fong ANG Department of Computer Science and Information Technology University of Malaya Kuala Lumpur 50603 Malaysia Department of Computer Science Universiti Tunku Abdul Rahman (Jalan Universiti) Kampar 31900 Malaysia

In this paper, a new scheme that uses digraph substitution rules to conceal the mechanism or activity re- quired to derive password-images is proposed. In the pro- posed method, a user is only required to click on one of the pass-image instead of both pass-images shown in each chal- lenge set for three consecutive sets. While this activity is sim- ple enough to reduce login time, the images clicked appear to be random and can only be obtained with complete knowl- edge of the registered password along with the activity rules. Thus, it becomes impossible for shoulder-surfing attackers to obtain the information about which password images and pass-images are used by the user. Although the attackers may know about the digraph substitution rules used in the pro- posed method, the scenario information used in each chal- lenge set remains. User study results reveal an average login process of less than half a minute. In addition, the proposed method is resistant to shoulder-surfing attacks.

关键词： graphical password authentication shoulder-surfing data and computer security digraph substitution rules

Development of a system configuration for a solar powered hydrogen facility using fuzzy logic control

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第11期14卷 822-834页

作者： Ying-tai LOONG Mahidzal DAHARI Hwa-jen YAP Hue-yee CHONG Department of Mechanical Engineering Faculty of Engineering University MalayaKuala Lumpur 50603 Malaysia

Solar energy is a natural resource which can be harnessed to provide clean electricity for hydrogen production ***, this technology is not widely used because of control issues, particularly for hydrogen refuelling stations. At present,direct or DC-DC converter couplings are the most common system configurations for hydrogen refuelling stations. However, these system configurations are costly and suffer from gas shortage at hydrogen refuelling stations. Furthermore, the hydrogen produced by such system configurations varies considerably depending on the levels of solar radiation. In order to address these issues, a new system configuration is proposed, incorporating the feedback signal of the storage level in the control system. The photovoltaic(PV) system, electrolyzer, and storage tank are integrated with a fuzzy logic controller(FLC) to determine the backup current compensation for electrolyzer operation in order to obtain the minimum power required for hydrogen production. The proposed FLC is constructed with three input variables which are the PV current, hydrogen storage level, and the battery state of charge. The rules-based fuzzy inference process is based on the proposed configuration which combines the advantages of direct and DC-DC converter coupling configurations. The simulation results show that the proposed configuration offers better adaptability to variable radiation conditions compared to other methods. This gives a more promising option for ensuring the adequacy of hydrogen supply at hydrogen refuelling stations.

关键词： Hydrogen energy Solar energy Hydrogen refueling facility Fuzzy logic

Construction of Conservative Numerical Fluxes for the Entropy Split Method

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Communications on Applied Mathematics and Computation 2023年第2期5卷 653-678页

作者： Björn Sjögreen H.C.yee Multid Analyses AB GothenburgSweden NASA Ames Research Center Moffett FieldCA 94035USA

The entropy split method is based on the physical entropies of the thermally perfect gas Euler *** Euler flux derivatives are approximated as a sum of a conservative portion and a non-conservative portion in conjunction with summation-by-parts(SBP)difference boundary closure of(Gerritsen and Olsson in J Comput Phys 129:245-262,1996;Olsson and Oliger in RIACS Tech Rep 94.01,1994;yee et *** J Comp Phys 162:33-81,2000).Sj?green and yee(J Sci Comput)recently proved that the entropy split method is entropy conservative and ***-ard high-order spatial central differencing as well as high order central spatial dispersion relation preserving(DRP)spatial differencing is part of the entropy stable split methodol-ogy *** current work is our first attempt to derive a high order conservative numerical flux for the non-conservative portion of the entropy splitting of the Euler flux *** to the construction,this conservative numerical flux requires higher oper-ations count and is less stable than the original semi-conservative split ***,the Tadmor entropy conservative(EC)method(Tadmor in Acta Numerica 12:451-512,2003)of the same order requires more operations count than the new *** the entropy split method is a semi-conservative skew-symmetric splitting of the Euler flux derivative,a modified nonlinear filter approach of(yee et *** J Comput Phys 150:199-238,1999,J Comp Phys 162:3381,2000;yee and Sj?green in J Comput Phys 225:910934,2007,High Order Filter Methods for Wide Range of Compressible flow *** of the ICOSAHOM09,June 22-26,Trondheim,Norway,2009)is proposed in conjunction with the entropy split method as the base method for problems containing shock ***-time integration of 2D and 3D test cases is included to show the com-parison of these new approaches.

关键词： Finite-difference method Entropy conservation Entropy splitting Shock capturing