• ETRI Journal
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• 제30권2호
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• pp.315-325
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• 2008

In this paper, we first investigate the side channel analysis attack resistance of various FPGA hardware implementations of the ARIA block cipher. The analysis is performed on an FPGA test board dedicated to side channel attacks. Our results show that an unprotected implementation of ARIA allows one to recover the secret key with a low number of power or electromagnetic measurements. We also present a masking countermeasure and analyze its second-order side channel resistance by using various suitable preprocessing functions. Our experimental results clearly confirm that second-order differential side channel analysis attacks also remain a practical threat for masked hardware implementations of ARIA.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.333-341
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• 1998

The general method of structural analysis for building structures has been based upon the assumption that all dead loads are imposed on a building simultaneously throughout the entire structure. In reality, buildings are built floor by floor or a few floors at a time. The construction dead load is applied gradually onto the structure as the structure is being erected. The prevailing commercial software for structural analysis used to date have resulted in the representation of inaccurate structural behaviors. The actual construction sequence and the loading of the structure ere not properly represented in the analysis. This paper identifies the source of the errors and develops the algorithm to account for the differential column shortening due to construction dead load based upon a given construction sequence

• 대한전기학회논문지:전력기술부문A
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• 제52권1호
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• pp.50-57
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• 2003

In this paper, the protective relay setting rules of Korean electric power system are studied by analysis of errors to be considered. An accurate operation of protective relays with accurate settings are important in power system reliability. The setting rules are used from the first establishment in 1982 and revision in 1990 Therefore, it needs revise and analysis of the setting rules because of environmental changes such as voltage raise or applied new technology of power system. Two major setting rules are studied. One is the rule for Zones of distance relay for transmission lines. The other is the one of differential current in a differential relay for power transformers. The range of errors in the setting rules accepted in the field experience is studied in simulation of case study. Also some guide lines for the range of errors in the setting rules are presented from the case study using Matlab simulation.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권1호
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• pp.9-15
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• 2003

This Paper deals with the design of Moving Magnet type Linear Oscillatory Actuator(MM-LOA) using spring damper based on the design procedure and the characteristic analysis. MM-LOA is applied to variable load such as vaccum pump and compressor, The structure of piston type is selected to reduce a noise. MM-LOA has over-displacement in starting state because of the low inertia of mover To improve the starting characteristic, spring damper is used. The optimum spring constant of spring damper is detected and in consideration of spring damper, MM-LOA redesigned. The parameter is calculated by Finite Element Method(FEM). For the dynamic characteristic analysis, time differential method composed of voltage and kinetic equation is used. The propriety of the improved model is verified through the experimental results.

• 한국조경학회지
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• 제23권3호
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• pp.155-166
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• 1995

The aim of this paper was to investigate images of neighborhood parks and pergola facilities. 280 individuals responded to the 19 semantic differential pollar terms for all four parks. A 7-point semantic differential scale was used. Results from the data analysis suggest several important findings; 1. Mean scores were significantly different in most of S.D.scales according to park and pergola facilities types. As compared with park, S.D.scales values of pergola varied with its visual identity in the spatial composition of park. 2. Data from the factor analysis revealed that four dimensions appeared for all park and pergola types : "Evaluation ", "Potentiality", "Variety", and "Familiarity". 3. In terms of the "Familiarity" dimension, Omok park and its pergola were viewed a ssignificantly more familiar than any of the other three areas. 4. Parks were perceived more positive than pergolas images in the dimensions of "Evaluation ", "Variety", and "Familiarity". 5. Regression analysis showed that "Evaluation "and "Variety" dimensions were mainly related to visual preference.

• 한국항해항만학회지
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• 제33권10호
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• pp.691-697
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• 2009

현재 운영되고 있는 해양용 DGPS 시스템은 하드웨어 RSIM 방식으로서 DGPS 구조개선시 고려해야 할 위성항법시스템의 다원화와 미래 해양 사용자의 최소 요구성능을 만족시킬 수 있는 기술 적용에 효율적이지 못하다는 문제가 있다. 본 논문에서는 이러한 문제를 해결하기 위하여 소프트웨어 RSIM 방식으로 해양용 DGPS 시스템을 구조개선하는 방안을 연구한다. 이를 위해 본 논문은 해양용 DGPS 시스템에 적합한 소프트웨어 RSIM 방식을 제안하고, 제안한 방법의 기술적 타당성 분석을 위하여 광대역폭, 높은 표본화 주파수, 데이터 고속전송 사양을 갖는 RF 모듈과 DSP 모듈을 제작하며, 이를 이용하여 제안한 방법을 적용한 해양용 DGPS 시스템을 구현한다. 그리고 신호처리 소요시간 분석을 통하여 개인용 컴퓨터 환경에서 제안한 소프트웨어 RSIM 방식이 실시간으로 운영됨에 문제가 없음을 보인다. 마지막으로 본 논문은 제안한 방법으로 설계된 DGPS 시스템의 보정정보 정확도가 RTCM 221-2006-SC104-STD을 통해 규정된 국제기구 요구성능을 만족시키고 있음을 확인한다.

• 정보교육학회논문지
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• 제20권5호
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• pp.527-534
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• 2016

본 연구는 소프트웨어에 대해 초등학생들이 가진 이미지를 의미분별법을 이용하여 분석하였다. 검사의 항목은 총 35쌍의 소프트웨어 이미지 형용사를 선정하여 요인분석을 통해 7개의 주요인으로 구분하고 초등학생을 대상으로 조사하였다. 성별 간 SW이미지를 분석한 결과 남학생보다는 여학생이 소프트웨어를 어렵고 복잡하게 여기며 느리고 갖고 싶지 않다는 인식을 보였다. 또한 소프트웨어에 대한 자기 인식의 분석 결과 소프트웨어에 대해 잘 안다고 인식할 경우 소프트웨어에 대한 긍정적인 용어를 선호하고 있었다. 학년간 분석에서 고학년이 될수록 소프트웨어를 어렵고 복잡하며 소프트웨어의 객관적인 특징에 대한 답변을 하였다. 본 연구를 통해 소프트웨어 교육이 정규교과로 안착되는데 필요한 방향을 안내하였다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2001년도 제2회 생물정보학 국제심포지엄
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• pp.77-102
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• 2001

Different high-throughput chip technologies are available for genome-wide gene expression studies. Quality control and prescreening analysis are important for rigorous analysis on each type of gene expression data. Statistical significance evaluation of differential expression patterns is needed. Major genome institutes develop database and analysis systems for information sharing of precious expression data.

• 대한수학교육학회지:수학교육학연구
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• 제23권2호
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• pp.75-94
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• 2013

본 연구는 2011년 수학과 국가수준 학업성취도 평가에서 다문화 탈북가정 학생들에게 차별기능을 하는 문항이 있는지를 분석하였다. 이를 위하여 먼저 Simultaneous Item Bias Test(SIBTEST) 방법과 MantelHaenszel(MH) 방법으로 다문화 탈북가정 학생들에 대한 차별기능문항을 추출한 결과, 초 중 고등 세 학교급에서 8개의 문항이 추출되었다. 이 문항들은 다문화 탈북가정 학생들의 학업성취 정도와 특성을 나타내는 객관적인 자료로서 기능할 것이다. 또한 추출된 각 문항을 질적으로 분석한 결과 다문화 탈북가정 학생들에게 차별기능을 한 잠재적인 원인을 탐색한 결과 언어 능력, 계산 및 문제 해결 과정의 복잡성, 교육과정의 일치 여부, 문제 상황 등이 영향을 미치는 것으로 나타났다. 본 논문은 다문화 탈북가정 학생들을 위한 교육 정책을 수립하고 교수 학습 방법을 구안하는 데 시사점을 제공할 수 있을 것이다.

• Journal of Preventive Medicine and Public Health
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• 제50권6호
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• pp.393-400
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• 2017

Objectives: To relieve the financial burden faced by households, the Korean National Health Insurance (NHI) system introduced a "copayment ceiling," which evolved into a differential ceiling in 2009, with the copayment ceiling depending on patients' income. This study aimed to examine the effect of the differential copayment ceiling on financial protection and healthcare utilization, particularly focusing on whether its effects varied across different income groups. Methods: This study obtained data from the Korea Health Panel. The number of households included in the analysis was 6555 in 2008, 5859 in 2009, 5539 in 2010, and 5372 in 2011. To assess the effects of the differential copayment ceiling on utilization, out-of-pocket (OOP) payments, and catastrophic payments, various random-effects models were applied. Utilization was measured as treatment days, while catastrophic payments were defined as OOP payments exceeding 10% of household income. Among the right-hand side variables were the interaction terms of the new policy with income levels, as well as a set of household characteristics. Results: The differential copayment ceiling contributed to increased utilization regardless of income levels both in all patients and in cancer patients. However, the new policy did not seem to reduce significantly the incidence of catastrophic payments among cancer patients, and even increased the incidence among all patients. Conclusions: The limited effect of the differential ceiling can be attributed to a high proportion of direct payments for services not covered by the NHI, as well as the relatively small number of households benefiting from the differential ceilings; these considerations warrant a better policy design.