• The Magazine of the IEIE
• /
• v.29 no.11
• /
• pp.1333-1342
• /
• 2002

최근 들어 컴퓨터 통신의 확산과 함께 인터넷의 사용이 전 세계적으로 급증함에 따라 인터넷의 용도는 지금까지의 학술 및 연구를 대상으로한 정보 공유의 목적에서 인터넷을 마케팅의 대상으로 보고 이를 상업적으로 이용하려는 시도가 증가하고 있다. 이미 선진 외국의 경우에는 Mon-dex, Visa cash, Proton 등의 다양한 전자화폐 상품이 개발되어 사용되고 있으나 국제 호환성의 측면에서는 아직 미미한 형편이며 국제간 통용이 가능한 개방형 전자화폐 시스템 개발은 매우 필요하다. 소액지불 시스템의 국제 표준규격으로 인정받고 있는 CEPS(Common Electronic Purse Specification) 기반의 개방형 전자화폐 teem 시스템은 EMV(Europay, Master, Visa) 규격을 준용하고, PKI 기반의 보안기능을 채택하여 지불거래시 반드시 확보되어야 할 거래 데이타의 비밀성, 무결성, 부인방지 기능과 PIN(Personal Identification Number)를 이용한 사용자 인증을 제공하며 구매거래시 IC카드와 가맹점의 구매 단말기(POS)와의 오프라인 동적데이타 인증 (Dynamic Data Authentication) 방식의 상호인증을 제공한다. 개방형 전자화폐 teem 시스템의 구성 모듈은 발급, 충전, 구매, 정산, 인증시스템으로 구성되어 있으며, 웹기반의 사용자 인터페이스를 제공하고 DES, 3-DES, SHA-1, RSA, SEED등 다양한 암호 모듈과 다양한 어플리케이션의 탐재가 가능한 Java Card를 기반으로 하고 있으며, VOP(Visa Open Platform) 2.0,1, Java Card API 2.1 지원하는 시스템이다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1366-1370
• /
• 2005

As the development of microprocessor technology, electric power steering (EPS) system which uses an electric motor came to use a few years ago. It can solve the problems associated with hydraulic power steering. The motor only operates when steering assistance is needed, so it can save fuel and can reduce weight and cost by eliminating hydraulic pump and piping. As one of performance criteria of EPS systems, the transmissibility from road wheel load to steering wheel torque is considered in the paper. The transmissibility can be studied by fixing the steering wheel and calculating the torque needed to hold the steering wheel from road wheel load. A proportion-plus-derivative control is needed for EPS systems to generate desired static torque boost and avoid transmissibility of fluctuation. A pure proportion control can't satisfy both requirements.

• Proceedings of the Korea Association of Information Systems Conference
• /
• 2001.12a
• /
• pp.377-386
• /
• 2001

최근 들어 일반인들을 대상으로 하는 인터넷 서비스가 보편화되면서 B2C 기반 전자상거래의 수요가 급속히 증가하고 있다. 뿐만 아니라 기업과 기업간(B2B) 혹은 기업과 정부간(B2G)의 전자상거래를 위한 포탈 사이트나 허브 사이트 등의 구축도 매우 활발히 이루어지고 있다. 이와 같은 인터넷 기반의 전자상거래 시스템은 사용자들에게 기존 상거래에서는 경험해 보지 못했던 다양하고 방대한 정보와 편리성 등을 제공하고 있다. 반면, 지불 정보나 구매 정보 혹은 개인 신상 정보 등의 유출과 같은 보안상의 문제점들을 해결해야 하는 어려움도 내재되어 있어 안전한 전자상거래를 보장하기 위한 일환으로 자바카드 기반의 사용자 인터페이스가 요구되고 있다. 여기서, 자바카드 상의 개방형 플랫폼 보안 서비스를 구현하는 것이 본 논문의 목적이다. 이러한 목적을 달성하기 위해 자바카드를 기반으로 하는 개방형 플랫폼상의 CEPS 보안 메커니즘을 분석하고, 개방형 플랫폼 구성요소인 보안 도메인(Security Domain)의 보안 요구사항에 근거한 자바카드 보안 서비스를 제공하는 기능을 구현한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2001.11a
• /
• pp.415-424
• /
• 2001

최근 들어 일반인들을 대상으로 하는 인터넷 서비스가 보편화되면서 B2C 기반 전자상거래의 수요가 급속히 증가하고 있다. 뿐만 아니라 기업과 기업간(B2B) 혹은 기업과 정부간(B2G)의 전자상거래를 위한 포탈 사이트나 허브 사이트 등의 구축도 매우 활발히 이루어지고 있다. 이와 같은 인터넷 기반의 전자상거래 시스템은 사용자들에게 기존 상거래에서는 경험해 보지 못했던 다양하고 방대한 정보와 편리성 등을 제공하고 있다. 반면, 지불 정보나 구매 정보 혹은 개인 신상 정보 등의 유출과 같은 보안상의 문제점들을 해결해야 하는 어려움도 내재되어 있어 안전한 전자상거래를 보장하기 위한 일환으로 자바카드 기반의 사용자 인터페이스가 요구되고 있다. 여기서, 자바카드 상의 개방형 플랫폼 보안 서비스를 구현하는 것이 본 논문의 목적이다. 이러한 목적을 달성하기 위해 자바카드를 기반으로 하는 개방형 플랫폼상의 CEPS 보안 메커니즘을 분석하고, 개방형 플랫폼 구성요소인 보안 도메인(Security Domain)의 보안 요구사항에 근거한 자바카드 보안 서비스를 제공하는 기능을 설계 및 구현한다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.25 no.1
• /
• pp.28-36
• /
• 2013

The aim of this study is to evaluate the performance of the GHP system with 45 cast-in-place energy piles(CEP) for a commercial building. In order to demonstrate the feasibility of a sustainable performance of the system, transient simulations were conducted over 1-year and 20-year periods, respectively. The 1-year simulation results showed that the maximum and minimum temperatures of brine returning from the CEPs were $23.91^{\circ}C$ and $6.66^{\circ}C$, which were in a range of design target temperatures. In addition, after 20 years' operation, these returning temperatures decreased to $21.24^{\circ}C$ and $3.68^{\circ}C$, and finally reached to stable state. Annual average extraction heat of cast-in-place energy piles was 94.3 MWh and injection heat was 65.7 MWh from the 20 years of simulation results. Finally, it is expected this GHP system can operate with average heating SPF of more than 3.45 for long-term.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.10
• /
• pp.2682-2700
• /
• 2023

To cope with the risks of climate change and promote the realization of carbon peaking and carbon neutrality, this paper first comprehensively considers the policy background, technical trends and carbon reduction paths of energy conservation and emission reduction in data center server industry. Second, we propose a computing power carbon efficiency of data center server, and constructs the carbon emission per performance of server (CEPS) model. According to the model, this paper selects the mainstream data center servers for testing. The result shows that with the improvement of server performance, the total carbon emissions are rising. However, the speed of performance improvement is faster than that of carbon emission, hence the relative carbon emission per unit computing power shows a continuous decreasing trend. Moreover, there are some differences between different products, and it is calculated that the carbon emission per unit performance is 20-60KG when the service life of the server is five years.

• Korean Journal of Ichthyology
• /
• v.27 no.4
• /
• pp.293-299
• /
• 2015

The feeding experiment was conducted to investigate the effects of one experimental diet (EDP) and five different commercial diets (CEPs) on growth and body composition for juvenile parrot fish, Oplegnathus fasciatus. An EDP was formulated to contain 50% crude protein (CP) from fishmeal, casein, zein and wheat flour and 15% crude lipid (CL) from squid liver oil. Five CEPs for seawater fish were two domestic E commercial diet (DECD) and C commercial diet (DCCD), three imported H commercial diet (IHCD), L commercial diet (ILCD) and O commercial diet (IOCD) containing 53.1~66.6% CP and 10.7~14.6% CL, respectively. Each diet was fed to triplicate groups of juvenile parrot fish initially weighing $1.14{\pm}.01g/fish$ (mean${\pm}$SD) in a flow-through seawater system with a water temperature of $19.0{\sim}25.0^{\circ}C$. Weight gain (WG) and feed efficiency (FE) were significantly greatest in fish fed the DCCD and IOCD; intermediate responses were observed for fish fed the ILCD, while the IECD, IHCD, and the EDP produced the lowest WG and FE values. Survival with no significant difference approached 100% for fish fed the all six diets in this experiment. Whole-body moisture, protein, lipid and ash contents were not affected by the different type of diets. Therefore, type of diets appeared to be important factor in influencing WG and FE of juvenile parrot fish; the best diets for juvenile parrot fish was determined to be the domestic commercial C and the imported commercial O diets containing high protein (61.3, 66.6%) and lipid (14.6, 13.0%) in natural seawater based on highest WG, and FE, respectively. This study indicates that the two commercially formulated diets containing two highest proteins and lipids used in this experiment could be practical diets for juvenile parrot fish; these differences of growth performance between experimental diet and commercial diets may be reason for different dietary protein and lipid levels.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.45 no.2
• /
• pp.139-145
• /
• 2012

Two feeding trials were conducted to evaluate the effects of experimental extruded pellets (EEPs) and commercial EPs (CEPs) on Far Eastern catfish $Silurus$ $asotus$ in pilot- (experiment I) and commercial-scale (experiment II) tanks. Four diets were prepared: three EEPs (EEP1, EEP2 and EEP3) that contained different amounts of tuna fish meal, soybean meal, and squid liver oil, and one CEP diet. In experiment I, three replicate groups of juveniles were fed one of the four EPs in pilot-scale tanks for 19 weeks. The weight gains (WGs) of fish fed EEP1 and CEP were significantly higher than those of fish fed EEP2 or EEP3. The highest feed efficiency (FE) was observed in fish fed the CEP diet ($P$<0.05), and the FE of fish fed EEP1 and EEP3 were significantly higher than that with EEP2 ($P$<0.05). In experiment II, juveniles were fed one of four EPs in commercial-scale tanks for 19 weeks. WG and FE values of fish fed EEP1 and CEP were higher than those of fish fed EEP2 and EEP3. The results of this study indicate that the dietary formulation used in EEP1 could be used as a practical feed for Far Eastern catfish.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.1 no.1
• /
• pp.107-114
• /
• 1998

Purpose: The purpose of our study is to provide useful information for me-asurement methods of childhood obesity and to provide clinical significance of bioelectrical impedance analysis. Methods: We measured height, weight, waist to hip ratio, skinfold thickness and bioelectrical impedance from 206 elementary students in Kwangju from May to July 1997. Results: In males; 1) There were statistically high correlations between tri-ceps skinfold thickness and body mass index (BMI), percentage of body fat (%BF), weight, Rohler index (RI), total fat weight (TFW), waist to hip (W/H) ratio, height, lean body mass (LBM) (all, p<0.001). 2) There were statistically high correlations between subscapular skinfold thickness and BMI, RI, weig-ht, %BF, TBW (all, p<0.001). 3) There were statistically high correlations between %BF and BMI, triceps skinfold thickness, RI, TFW, subscapular skinfold thickness, weight (all, p<0.001). In females; 4) There were statistically high correlations between triceps skinfold thickness and BMI, weight, LBM, height, %BF (all, p<0.001). 5) There were statistically significant correlations between subscapular skinfold thickness and BMI, weight, LBM, RI, height. 6) There were statistically high correlations between percentage of body fat and BMI, RI, triceps skinfold thickness. The percentage of body fat according to the bioelectrical impedance analysis highly correlated with that calculated by skinfold thickness in males (r＝0.57, p<0.01) and in females (r＝0.30, p<0.01). Conclusion: The results of our study suggests that bioelectrical impedance analysis is a useful method of estimating body fat in the childhood obesity.