• Electronics and Telecommunications Trends
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• v.16 no.6 s.72
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• pp.49-55
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• 2001

정보통신 기술의 발전과 인터넷 이용 확산 등으로 사용자 인증이 중요한 문제로 대두되면서 타인에게 노출되거나 잊어버리는 등의 문제점이 있는 패스워드 또는 PIN을 이용한 사용자 인증 방법을 대체하거나 보완하기 위한 방법으로 개인의 고유한 생체정보를 이용한 사용자 인증 방법에 관한 연구가 진행되고 있다. 또한 컴퓨터 관련 기술의 발달로 32비트 CPU와 메모리 등을 내장한 IC 카드가 개발되면서 최근에는 생체정보를 이용한 사용자 인증 기술과 IC 카드와의 접목이 시도되고 있다. 즉, IC 카드를 이용한 생체인식 기술은 각 개인의 중요한 정보인 생체정보가 중앙컴퓨터에 저장되지 않고 개인이 소지하고 있는 IC 카드에 저장되고 사용자 인증도 IC 카드에서 수행하는 것이다. 본 고에서는 생체인증과 IC 카드에 관하여 알아보고 IC 카드를 이용한 생체인증 기술과 개발 현황에 대하여 설명한다.

• Journal of Applied Reliability
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• v.7 no.1
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• pp.23-29
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• 2007

Probe card is a test component which is to classify the known good die with electrical contact before the packaging in the ATE (automatic testing equipment). Conventional probe tip was mostly needle type, it has been difficult to meet with conventional type, because of decreasing chip size, pad to pad pitch and pads size increasingly. For that reason, probe cards using MEMS (micro electro mechanical system) technology have been developed for various semiconductor chips. In this paper, Area Array type MEMS Probe tip was designed,, fabricated, and characterized its mechanical and electrical properties. The authors found that good electrical characteristics under $1{\Omega}$ were acquired with gold (Au) and aluminium (Al) pad contact test over 0.5gf and 4gf respectively. And, contact resistance variation under $0.1{\Omega}$ were achieved with 100,000 times of repetition test. And, insertion loss (IS) for high frequency operation was ascertained over 300MHz at -3dB loss.

• Journal of Korean Elementary Science Education
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• v.27 no.3
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• pp.287-295
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• 2008

Elementary students' behaviors classifying leaves have been analyzed according to the material types provided for the classification class. 199 sixth grade students were participated in the task classifying the leaves of various plants for the research. The three types of materials provided to them for the class were real leaves, photos of the leaves and explanation cards including the photos of leaves. One of the research findings was that the only material made students handle in the observed behaviors was the real leave of the material types given as classifying. Three were differences between groups in the time required and the number of using criteria for the class. The numbers of criteria had been applied to analyzing their behaviors as classifying the real leaves which were less than those with photo materials. The amount of taken time to classify the real leaves and photo materials were less than those of another material. Finally, the contents of criteria did not differ between groups except appearing properties presented to the task with photo and explanation materials. It is expected that the research can be contributed for elementary school teachers and for curriculum developers to choose appropriate instructional materials as constructing curriculum contents for elementary science to make elementary school students acquire classifying skill in science classes.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.2
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• pp.35-54
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• 2009

The recent economic crisis not only reduces the profit of department stores but also incurs the significance losses caused by the increasing late-payment rate of credit cards. Under this pressure, the scope of credit prediction needs to be broadened from the simple prediction of whether this customer has a good credit or not to the accurate prediction of how much profit can be gained from this customer. This study classifies the delinquent customers of credit card in a Korean department store into homogeneous clusters. Using this information, this study analyzes the repayment patterns for each cluster and develops the credit prediction system to manage the delinquent customers. The model presented by this study uses Kohonen network, which is one of artificial neural networks of data mining technique, to cluster the credit delinquent customers into clusters. Cox proportional hazard model is also used, which is one of survival analysis used in medical statistics, to analyze the repayment patterns of the delinquent customers in each cluster. The presented model estimates the repayment period of delinquent customers for each cluster and introduces the influencing variables on the repayment pattern prediction. Although there are some differences among clusters, the variables about the purchasing frequency in a month and the average number of installment repayment are the most predictive variables for the repayment pattern. The accuracy of the presented system leaches 97.5%.

• Human Ecology Research
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• v.54 no.1
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• pp.45-56
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• 2016

This study investigates: (1) children's proactive aggression according to age and the emotional condition of the counterpart child, (2) if children's intention attribution, emotional attribution (victim and perpetrator) and language ability influences proactive aggression according to age and the emotional condition of the counterpart child. The subjects were 68 3-year-old and 70 5-year-old children. Each child was individually interviewed with picture cards. Collected data were coded and analyzed in SPSS with frequencies, percentiles, means, standard deviations, repeated measures analysis of variance (ANOVA), t -tests, Pearson correlations and multiple linear regression. The results showed that 3-year-old children showed more proactive aggression and physical aggression than 5-year-old children. They showed more proactive aggression when counterpart child was in a happy condition than in a fear condition. Intention attribution, emotional attribution, and language ability partially affected a children's proactive aggression according to age and the emotional condition of the counterpart child. This study has practical implications for teachers in regards to children's proactive aggressive behavior at child care centers. Teachers use specific to develop advantages as the basis for developing aggression prevention programs that consider emotional and cognitive factors.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.7
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• pp.389-398
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• 2000

The popular methods to check the identity of individuals include passwords and ID cards. These conventional method for user identification and authentication are not altogether reliable because they can be stolen and forgotten. As an alternative of the existing methods, biometric technology has been paid much attention for the last few decades. In this paper, we propose an efficient system for recognizing the identity of a living person by analyzing iris patterns which have a high level of stability and distinctiveness than other biometric measurements. The proposed system is based on wavelet transform and a competitive neural network with the improved mechanisms. After preprocessing the iris data acquired through a CCD camera, feature vectors are extracted by using Haar wavelet transform. LVQ(Learning Vector Quantization) is exploited to classify these feature vectors. We improve the overall performance of the proposed system by optimizing the size of feature vectors and by introducing an efficient initialization of the weight vectors and a new method for determining the winner in order to increase the recognition accuracy of LVQ. From the experiments, we confirmed that the proposed system has a great potential of being applied to real applications in an efficient and effective way.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.86.2-86.2
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• 2014

We present a new ray-tracing code, "Odyssey", for the Kerr spacetime accelerated by the Graphics Processing Unit (GPU). Taking advantage of the ability of nVidia graphic cards to evaluate trajectories of a large amount of photon simultaneously, the code is two orders of magnitude as fast as the previous CPU-based code corresponding to the speed of few nanoseconds per photon per time step. In the light of the Graphic User Interface (GUI) powered by the GPU-enhanced 2D/3D displaying technique, DirectX, it is feasible for users to manipulate diverse results such as rotating and zooming in/out the trajectories of photon instantly near the black hole. Thus the Odyssey can serve as a tool not only for scientific but also for the educational purpose. We discuss possible applications in detail in light of several results such as the shape of the silhouette of a black hole, the shape of a hot spot orbiting a black hole, and 3D photon trajectories.

• Journal of the Korean Home Economics Association
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• v.44 no.2 s.216
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• pp.61-69
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• 2006

The purposes of this study were,1) to examine the clothing purchase behaviors of the elderly, and 2) to investigate the relationships of clothing purchase behaviors, information source, service quality and clothing buying motive, which may provide insights related to the silver market. Data were obtained for women in their 50's and 60's women living in Busan (N=285), and analyzed using to factor analysis, Cronbach's alpha, ANOVA and Duncan test. The research findings of the research wereare asan follows. The elderlys women bought clothes with their her friends, used credit cards, and usually shopped at the department stores. There were partly significant (Ed- it cannot be 'partly' either it was significant or it was not) differences in clothing purchase behaviors, information source, and service quality by clothing buying motive types. The ostentation group considered more massmideamass mediainformation sources and experience/salespersons/observation information sources, more was higher than the economic group and utility groups. The ostentation group and economical groups attached more importance to Facilities Service and Policy Service in service quality, was higher than the utility group. The Iimplications and drawn from the study results for the information will be useful to consumer behavior researchers and retailers of the silver market.

• Journal of the Korean Operations Research and Management Science Society
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• v.27 no.4
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• pp.185-205
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• 2002

In this study, we consider infinite supply of raw materials and backlogged demands as given two boundary conditions. And we need not make any specific assumptions about the inter-arrival of external demand and service time distributions. Under these situations, the ultimate objective of this study is to prove the variability propagation principle in a pull serial line and is to measure it in terms of the first two moments of the inter-departure process subject to number of cards in each cell. Two preparations are required to achieve this objective : The one is to derive a true lower bound of variance of the inter-departure process. The other is to establish a constrained discrete minimax problem for the no backorder (backlogging) probabilities in each cell. We may get some fundamental results necessary to a completion for the proof through the necessary and sufficient conditions for existence of optimal solution of a constrained discrete minimax problem and the implicit function theorem. finally, we propose a numeric model to measure the variability propagation principle. Numeric examples show the validity and applicability of our study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.275-277
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• 2015

This paper proposed have been the business card information to the computer when creating business card printing agency saved to a file, there is always the risk of personal information leakage. Application file organization information into the card, the name, phone number, email address information, such as is capable of easily accessible because it is not encrypted. This paper proposed it encrypts the information entered on the Business Card application file to automate the process of the card application and simplifying the business card application process minimizes the work of staff and linked directly to the print shop how to automatically delete the print file after the completion of business card printing and research.