http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Study on Effect of Left-Truncated Data Rate on ML Estimation for Power Law Process
Alfonsus Julanto Endharta,김종운,최성수 한국철도학회 2019 한국철도학회논문집 Vol.22 No.9
This paper used parameter estimation to analyze left-truncated and right-censored failure time data frommultiple repairable systems. The systems were identical; the failure occurrence followed a Non-Homogeneous PoissonProcess (NHPP) and the intensity rate function followed a power law function. Maximum Likelihood (ML) method wasused to estimate the function parameters. Two scenarios were considered. In the first scenario, it was assumed that therewere no failures between the operation starting time and the observation starting time points. In the second one, lefttruncationwas considered and thus the possibility of failure occurrence existed between the operation starting time andthe observation starting time points. The parameters estimated from these scenarios were compared to the real inputparameters in the data generation to show the importance of the truncation information.
( Alfonsus Adrian Hadikusumo ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1
Background: Hepatitis B virus (HBV) and human immunodefi ciency virus (HIV) are among sexually transmitted viruses, which transgender persons are susceptible. Besides, Indonesia is a country with moderate to high endemicity of HBV infection, and with rapid epidemic growth of HIV. As a virus which can be co-infected with HBV and HIV, hepatitis C virus (HCV) was also detected. Aims: To know the prevalence of and molecular analyze HBV, HCV and HIV infections among transgender in Surabaya, Indonesia. Methods: A total of 107 sera were taken from transgender in a Health Center in port area of Surabaya. Sera were screened for antibody to HIV (anti-HIV) using ELISA and Chromatography, then for hepatitis B surface antigen (HBsAg) using reverse passive hemagglutination, hepatitis B core antibody (Anti-HBc) using passive hemagglutination, and hepatitis C antibody (Anti-HCV) using particle agglutination. Samples with HBsAg or Anti-HBc positive were then amplifi ed in part of S gene by PCR for HBV DNA detection. All of which were then sequenced and analyzed. Results: Six (5.6%) of 107 individuals were HBsAg positive, nineteen (18.8%) of 101 with HBsAg negative were anti-HBc positive. Seven (6.5%) of 107 were Anti-HCV positive, and none (0%) were HIV positive. The phylogenetic analysis of ten HBV DNA strains (six HBsAg positive and four anti-HBc positive) shows that four of which were genotype C, which is uncommon in Surabaya, while the other six were genotype B. Conclusions: We found a high, ten (9.3%) of 107, prevalence of HBV carriers with a prominent HBV genotype C in transgender in Surabaya - Indonesia. Interestingly, a high prevalence of HCV among transgender was also found. The possibility of the mechanism will be discussed.
Condition-based maintenance policy for linear consecutive-<i>k</i>-out-of-<i>n</i>: <i>F</i> system
Endharta, Alfonsus Julanto,Yun, Won Young Informa UK (TaylorFrancis) 2017 Communications in statistics Simulation and comput Vol.46 No.4
<P>In the article, a condition-based maintenance policy is proposed for a linear consecutive-k-out-of-n: F system. The failure times of components are assumed to be independent and identically distributed. It is assumed that the component states in the system can be known at any time and the system failure can be detected immediately. The preventive maintenance action is based on the number of working components in minimal cut sets of the system. If there is at least one minimal cut set consisting of only one working component, the system is maintained preventively after a certain time interval. The proposed policy is compared with corrective maintenance and age-based maintenance policies. As an extended case, it is assumed that the component states can only be known by inspection, but the system failure can be detected immediately. In this case, the system is inspected periodically and is also maintained preventively based on the system state at inspection. Numerical examples are studied to evaluate the performance of the proposed policy and investigate the effects of cost parameters on the expected cost rate.</P>
Endharta, Alfonsus Julanto,Yun, Won Young,Ko, Young Myoung Elsevier 2018 Reliability engineering & system safety Vol.180 No.-
<P><B>Abstract</B></P> <P>This paper studies a circular <I>k</I>-out-of-<I>n</I>: G balanced systems with identical and independent spatially distributed units. The system consists of an even number of units <I>n</I> which have constant survival probability <I>r</I> and failure probability 1 – <I>r</I>. The system is operating if at least <I>k</I> units are operating and it is balanced. A new balance definition is proposed for this system and the system reliability is calculated when the existing and the proposed system balance conditions are considered. The minimal path sets of the system are considered in the evaluation of the system reliability. The difference between the system reliability values reinforces the need to carefully select the system balance definition, depending on the system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Reliability of circular <I>k</I>-out-of-<I>n</I>: G balanced system is evaluated. </LI> <LI> New balance condition is defined. </LI> <LI> New method to evaluate the system balance is proposed. </LI> <LI> Procedure to enumerate the minimal path sets is built. </LI> <LI> System reliability increases for certain cases. </LI> </UL> </P>
Industrial robustness linked to the gluconolactonase from Zymomonas mobilis
Alvin, Alfonsus,Kim, Junhyun,Jeong, Gwi-Taek,Tsang, Yiu Fai,Kwon, Eilhann E.,Neilan, Brett A.,Jeon, Young Jae Springer-Verlag 2017 Applied microbiology and biotechnology Vol.101 No.12
<P>The physiological characteristics and the potential gluconolactone production of the gluconolactonase-deficient strain, Zymomonas mobilis ZM4 gnl Delta, were investigated via growth inhibitory assay and biotransformation of glucose and fructose into gluconolactone and sorbitol, respectively. The results of ethanol fermentation studies performed in the presence of high concentration of glucose (> 200 g l(-1)) under fermentative or aerobic conditions indicated that a significant reduction of volumetric ethanol productivity from the strain of ZM4 gnl Delta was noticeable due to the reduced rates of specific growth, sugar uptake, and biomass yield as compared with those of the parental strain ZM4. The biotransformation prepared at pH 6.0 using the permeabilized cell indicated that gluconic acid from ZM4 gnl Delta was still produced as a major product (67 g l(-1)) together with sorbitol (65 g l(-1)) rather than gluconolactone after 24 h. Only small amount of gluconolactone was transiently overproduced up to 9 g l(-1), but at the end of biotransformation, all gluconolactone were oxidized into gluconic acid. This indicated that autolysis of gluconolactone at the pH led to such results despite under gluconolactonase inactivation conditions. The physiological characteristics of ZM4 gnl Delta was further investigated under various stress conditions, including suboptimal pH (3.5 +/- 6.0), temperature (25 +/- 40 A degrees C), and presence of growth inhibitory molecules including hydrogen peroxide, ethanol, acetic acid, furfural, and so forth. The results indicated that ZM4 gnl Delta was more susceptible at high glucose concentration, low pH of 3.5, and high temperature of 40 A degrees C and in the presence of 4 mM H2O2 comparing with ZM4. Therefore, the results were evident that gluconolactonase in Z. mobilis contributed to industrial robustness and anti-stress regulation.</P>
RAM-C 분석을 통해 무기체계에 CBM+ 적용 효과도에 관한 연구
엔드하르타 알폰수스 주란토(Alfonsus Julanto Endharta),김영선(Young-Seon Kim),김종운(Jongwoon Kim),조일훈(Il-Hoon Cho),박연경(Yun-Kyung Park) 한국산학기술학회 2023 한국산학기술학회논문지 Vol.24 No.9
본 논문은 RAM-C(신뢰성 기반 비용 관리) 분석을 통해 무기체계에서 상태기반정비(Condition-Based Maintenance, CBM+) 적용의 효과에 대한 연구를 제시한다. 연구의 목적은 RAM-C 지표에 대한 CBM+ 적용 효과를 평가하고 CBM+적용에 의한 잠재적인 장점을 식별하는 것이다. 고려하는 주요 지표는 운용 가용도와 같은 핵심성능지표(Key Performance Parameter, KPA)와 O&S(운용 및 지원) 비용과 같은 핵심시스템속성(Key System Attribute, KSA)이다. 무기체계의 성능, 신뢰성, 가용성, 유지보수 비용을 평가하기 위해 모델링 및 시뮬레이션(Modelling and Simulation, M&S) 접근 방식을 사용한다. 레이더 시스템이 사례 연구로 사용한다. 본 연구에서 제시된 결과는 CBM+ 적용을 통해 무기체계의 유지보수 프로세스를 최적화하는 데 관련된 방위 산업 전문가, 시스템 설계자 및 의사 결정자에게 실질적인 시사점을 제공할 수 있다. This paper presents a study on the effectiveness of condition-based maintenance plus (CBM+) implementation in weapon systems through RAM-C (reliability, availability, maintainability, and cost) analysis. The aim of this study was to assess the effect of CBM+ application on RAM-C parameters and identify the potential benefits and challenges associated with its adoption. The key parameters considered in the study are key performance parameters, such as operational availability, and key system attributes, such as operating and support cost. The study employed modeling and simulation to assess the performance, reliability, availability, and maintenance cost of weapon systems. A radar system was used as a case study. The results presented in this study have practical implications for defense industry professionals, system designers, and decision-makers involved in optimizing the maintenance processes of weapon systems through CBM+ adoption.