• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.6
• /
• pp.693-699
• /
• 2011

In this study, a hydraulic system of a mini-loader is modeled, and the model is validated by comparing the simulation results to the experimental results. A load force acting on the structure of the mini-loader is obtained from the simulation of the hydraulic system, and the structural analysis via finite element method is performed using the obtained load force to evaluate the structural safety of the loader. For the mainframe that requires additional strengthening according to the structural analysis, the optimum design parameters are proposed using the design of experiments to improve strength without additional mass.

• Health Policy and Management
• /
• v.15 no.2
• /
• pp.53-69
• /
• 2005

This study has two different objectives. First of all is to comparing results of size efficiency scoring on Public Corporation Medical Center(PCMC) by years of 1993, 1997 and 2003 using Data Envelopment Analysis (DEA). The second is to explore the relationship between revenue and PCMCs' efficiency score, and the relationship between expenses and the efficiency score in 2003. The average efficiency scores were significantly decreased by years of 1993, 1997 and 2003. The revenue per bed(revenue) in 2003 was smaller than the expenses per bed(expenses) in 2003, therefore PCMCs had deficits in 2003. The expenses was negatively related to the efficiency score. Therefore its means was that improving efficiency score decreased expenses. Contrarily, the revenue had any significant relation to the efficiency score. PCMC needs to various endeavors to improve their productivity and efficiency. One of the alternatives is reduce of work load through integration of PCMC and development of new performance index reflecting their situation and future direction.

• Journal of the Korean Applied Science and Technology
• /
• v.16 no.1
• /
• pp.75-81
• /
• 1999

HF purification performance of an ion exchange membrane(IEM) was evaluated with 0.5% HF spiked with 10ppb of Fe, Ni and Cu nitrates. The result show that after less than five turnovers through an IEM, the metallic impurity concentration drops below 1ppb. The decrease rate can be fitted to a model assuming the experimental tanks to be continuously stirred tank reaction and that the metallic impurity concentration after the IEM is a function of the single-pass purification efficiency of the membrane, the concentration before purification and the metals desorbed form the IEM. The Concentration after purification was investigated up to a cumulative Fe loading of 300ppb in the 23 liter recirculated loop. It increases linearly vs. cumulative loading and can be explained by the Langmuir theory resulting in a purification efficiency at the equilibrium of close to 99.5% in this loading regime.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.10
• /
• pp.283-293
• /
• 2020

This study examines the effect of service quality and perceived value on customer loyalty with the intervening role of customers' satisfaction in the e-commerce industry. The research method uses a quantitative research design with a survey model. The sample used in this study is Tokopedia consumers who live in DKI Jakarta and have done online shopping at Tokopedia at least twice in the last six months. All variables used were reliable and valid and met the research requirements. The object of this research were the 200 customer respondents who had made purchases on the largest e-commerce platform of Indonesia, Tokopedia. Data analysis was done by using SPSS and Structural Equation Modeling (SEM). The results show that: first, the service quality and perceived value affect customer satisfaction positively. Second, there is a mediating effect of customer satisfaction on the relationship between service quality and perceived value on customer loyalty. Third, service quality and perceived value directly affect customer loyalty positively but insignificantly. The result implies that the role of customer satisfaction is significant in creating loyalty. In the e-commerce industry, good quality and perception could positively influence customers but not necessarily form loyalty. For that, e-commerce players should pay a lot of attention on customer satisfaction.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.5
• /
• pp.145-154
• /
• 2007

Analyzed about a matter and requirements to intimidate security of ubiquitous and home network threatening various security for personal information protection in ubiquitous home networks at this paper, and studied. Got authentication procedures and verification procedures acid user approach to be reasonable through designs to the home security gateway which strengthened a security function in the outsides, and strengthened protection of a home network. Also, execute a DoS. DDoS, IP Spoofing attack protective at home network security gateways proved, and security regarding against the Hacker's attack was performed, and confirmed. Strengthen appliances and security regarding a user, and confirm a defense regarding an external attack and present a home network security model of this paper to the plans that can strengthen personal information protection in ubiquitous home networks in ubiquitous home networks through experiment.

• KSCI Review
• /
• v.15 no.1
• /
• pp.65-75
• /
• 2007

Analyzed about a matter and requirements to intimidate security of ubiquitous and home network threatening various security for personal information protection in ubiquitous home networks at these papers, and studied. Got authentication procedures and verification procedures acid user approach to be reasonable through designs to the home security gateway which strengthened a security function in the outsides, and strengthened protection of a home network. Also, execute a DoS, DDoS, IP Spoofing attack protective at home network security gateways proved, and security regarding an external denial of service attack was performed, and confirmed. Strengthen appliances and security regarding a user, and confirm a defense regarding an external attack like DoS, DDoS, IP Spoofing, and present a home network security model of this paper to the plans that can strengthen personal information protection in ubiquitous home networks in ubiquitous home networks through experiment.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.9
• /
• pp.1346-1350
• /
• 2004

Pseudo-first order rate constants $(k_{obs})$ are reported for the following solvolyses in approximately isodielectric mixtures: 3- and 4-methoxybenzyl chloride, bromo- and chlorodiphenylmethane, and 4-chloro-, 4,4'-dichloro and 4-methyl-chlorodiphenylmethane in 0-80% v/v nitromethane-methanol mixtures; and bromo- and chlorodiphenylmethane and 4-methyl-chlorodiphenylmethane in various acetonitrile-methanol mixtures (in the range 0-50% v/v) at$25^{\circ}C.$ These data, and literature data for t-butyl halides (Cl, Br, and I), and for p-methoxybenzoyl chloride, show rate maxima in solvent compositions of ca. 30% aprotic cosolvent, explained by a stoichiometric solvent effect on electrophilic solvation. Linear relationships are observed between $(k_{obs})/[MeOH]^2$ and [AP]/[MeOH], where [AP] refers to the molar concentration of aprotic cosolvent. The results are consistent with competing third order contributions to $k_{obs}$, $k_{MM}[MeOH]^2$ with hydrogen-bonded methanol as electrophile, and $k_{MAP}[MeOH][AP]$ with hydrogen-bonding disrupted by the aprotic solvent.

• Journal of Navigation and Port Research
• /
• v.26 no.2
• /
• pp.161-166
• /
• 2002

In view of the great disparity between forecasts of Shanghai port container handling capacity and its real results, we choose a dynamic forecast method by the causality model dynamic compensation to predict Shanghai port container handling capacity. And we forecast Shanghai port container handling capacity by using this method. We have made a satisfactory achievement, which provides a more reliable and practical way to forecast container handling capacity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.307-310
• /
• 2011

본 논문은 공공자격 온라인 처리시스템의 예외사항 및 오류처리에 대한 관리 효율성을 극대화하기 위한 연구로 다양한 이론에 근거한 IT 거버넌스 체계를 적용하여 실제 운영시스템에 적용한다. IT거버넌스에 기반 한 예외사항 및 오류처리에 관하여 공공자격 온라인 처리시스템의 개발 전략과 목표를 기준으로 구축, 운영, 지원, 모니터링 등에 대하여 각각의 처리모듈에서 발생 가능한 예외사항과 오류처리에 대하여 시스템 관리자와 함께 일반 행정처리 중심의 사용자를 바탕으로 한 처리 지침의 세부적 사항을 기술적으로 적용하는 개발 방법론을 도입한다. 개발자와 관리자 및 행정사용자가 중심체계가 되는 방법론을 적용하여 예외사항 및 오류처리에 대한 지침서를 모델링하는 본 논문은 공공자격처리시스템 프로젝트를 일반 및 실무분야에 대한 2개의 대규모 개발 시스템으로 분류하고 세부사항을 도출하고 운영책임 관리자와 일반 행정처리 사용자에게 적용하여 결과를 평가한다. 국가정보화 IT거버넌스 혁신을 통하여 8가지 영역의 표준 지침서 제작의 필요성이 대두되어지는 관점에서 본 연구가 국가가 시행하는 공공자격 처리시스템의 특수 분야에서 확장되어진 기술적 공유를 추구할 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05a
• /
• pp.36-37
• /
• 2004

$\alpha$-Chloromethylnaphthalene is a valuable compound for obtaining of the plant growing stimulator - $\alpha$-napthylacetic acid. Chloromethylation of naphthalene by paraformaldehyde in the presence of glacial acetic acid, phosphoric and hydrochloric acids at temperature 80-85$^{\circ}C$ and duration - 6 hours the $\alpha$-chloromethyl-naphthalene yield was 55-57%. Using Box-Wilson method for mathematical planning of experiment carried out optimization of its synthesis for purpose increasing $\alpha$-chloromethylnaphthalene yield. Preliminary, one - factor experiments were carried out for selecting independence main parameters influencing on the synthesis. A full factor experiment of 2$^3$with extended matrix of planning was used for optimization. Aiming to increase the $\alpha$-chloromethylnaphthalene yield, the obtained mathematical model was used for program of sharp raising on the reply surface. The received optimal conditions for the $\alpha$-chloromethylnaphthalene synthesis were selected as following: molar ratio of naphthalene - parapfsormaldehyde of 1 : 2; temperature -105$^{\circ}C$; duration of the reaction -3 hours. The yield of $\alpha$-chloromethylnaphthalene under these optimal conditions was 75 %.