• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.163-165
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• 2018

GF(p)상 타원곡선 암호(ECC)와 RSA를 단일 하드웨어로 통합하여 구현한 공개키 암호 프로세서를 설계하였다. 설계된 EC-RSA 공개키 암호 프로세서는 NIST 표준에 정의된 소수체 상의 224-비트 타원 곡선 P-224와 2048-비트 키 길이의 RSA를 지원한다. ECC와 RSA가 갖는 연산의 공통점을 기반으로 워드기반 몽고메리 곱셈기와 메모리 블록을 효율적으로 결합하여 최적화된 데이터 패스 구조를 적용하였다. EC-RSA 공개키 암호 프로세서는 Modelsim을 이용한 기능검증을 통하여 정상동작을 확인하였으며, $0.18{\mu}m$ CMOS 셀 라이브러리로 합성한 결과 11,779 GEs와 14-Kbit RAM의 경량 하드웨어로 구현되었다. EC-RSA 공개키 암호 프로세서는 최대 동작주파수 133 MHz이며, ECC 연산에는 867,746 클록주기가 소요되며, RSA 복호화 연산에는 26,149,013 클록주기가 소요된다.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.205-207
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• 2005

In this paper, the Point of Common Coupling (PCC) is selected to analyze harmonic characteristic of distribution system by IEC 61000 - 3 - 6 in Electromagnetic Compatibility(EMC). Harmonic voltage and current were measured at the PCC of real distribution system. Harmonic distribution, nonlinear load component and Total Harmonic Distortion(THD) were verified by measurement. The effective and accurate modelling of real distribution system were proved through a analysis of harmonic impedance, voltage and current in steady-state. Harmonic transfer characteristic in distribution system were summarized and investigated through a analysis of harmonic voltage and harmonic current in harmonic current source.

• Communications for Statistical Applications and Methods
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• v.18 no.1
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• pp.13-21
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• 2011

This paper studies the analysis of multivariate nonstationary time series with seasonality. Three types of multivariate time series models are considered: seasonal cointegration model, nonseasonal cointegration model with seasonal dummies, and vector autoregressive model in seasonal differences that are compared for forecasting performances using Korean macro-economic time series data. The cointegration models produce smaller forecast errors in short horizons; however, when longer forecasting periods are considered the vector autoregressive model appears preferable.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.476-477
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• 2008

초전도 소자만을 이용한 한류기는 여러 가지 해결해야할 비용적, 기술적 문제를 안고 있다. 이런 문제들에 대한 해결과 동시에 초전도 한류기의 실용화를 위해 하이브리드 방식의 한류기가 고안되었으며 이는 초전도 소자만을 이용한 한류기가 갖고 있는 많은 문제점들을 해결할 수 있다고 판단되는 한류 방식이다. 본 논문은 기존의 하이브리드 방식의 한류기를 바탕으로 하여 Phase Locked Loop(PLL, 위상동기회로)를 이용한 하이브리드 방식의 초전도 한류기를 제시하였다. 일정한 선로 임피던스를 갖는 계통에서 사고가 발생할 경우 고장전류와 정상 상태의 전류 사이에 위상차가 발생하게 되는데, 이 위상차를 PLL의 위상 검출 능력을 통해 검출함으로써 한류기로서 동작할 수 있도록 하였다. 제시된 하이브리드 한류기의 성능은 PSCAD/EMTDC를 이용한 시뮬레이션을 통해 일기무한모선 시스템에 대한 적용을 통해 평가하였다.

• Korean Journal of Adult Nursing
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• v.25 no.1
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• pp.83-94
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• 2013

Purpose: The purpose of the study was to examine the sexual behavior and awareness of sexually transmitted diseases (STD) among the elderly. Methods: Subjects were 599 elderly living in a metropolitan area who completed a structured questionnaire. Data collection was from September 6, 2011 to January 17, 2012. The data were analyzed by using percentage and ${\chi}^2$-test. Results: Approximately 25% of the subjects reported a sexual life. Age, gender, education, family type, presence and health of spouse, health state of the subject, past occupation, dwelling pattern, and economic state made statistically significant difference in sexual behavior. Fifty five percent of the respondents reported no knowledge of STD. Factors such as age, gender, education, presence of spouse, and past occupation were statistically significant in terms of awareness of STD. Conclusion: Age, education, and presence of spouse should be factored in to understand the sexuality of the elderly as well as to develop sexuality counseling programs that provide adequate information for each individual.

• Journal of Korean Society for Quality Management
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• v.27 no.2
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• pp.277-290
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• 1999

In this paper we compare several statistical packages and propose basic requirements of the package for the efficient education of statistics. We develop a statistical software, KESS, based on Excel. KESS provides all the input menus and output results in Korean.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2004.05a
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• pp.219-224
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• 2004

The present study was to investigate the heat transfer enhancement effect of coil wire fins in an ice storage system. For the two cases of tubes with internal brine flows, a finned tube with coil wires on its outer surface and a smooth tube, the rates of ice layer were tested and compared for both the icing processes. The coil fins were made of a stainless steel wire with a dia. of 2.0(mm), and the coil had an outer dia. of 10(mm) and a helix angle of 60($^{\circ}$). The experimental results showed that the coil fins could substantially reduce the thermal resistance of the ice layer, and enhance the heat flow rates between the water in the storage tank and the brine. The ice storing time was found to be shortened by 13(%) for the coil fins to get the same amount of ice layer that was built on the smooth tube wall for 10 hours of operation when the same thermal conditions were provided.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.2
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• pp.49-52
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• 2001

conditions for callus induction and plant regeneratin from seeds of lawngrass (Zoysia japonica Steud.) were confirmed in this study. MS (Murashige and Skoog) medium containg 2,4-D 3 or 5mg/l was used for callus induction, and MS medium with different volumes of BA, NAA and kinetin hormones was used to regenerate the plants from induced calli. MS basic medium containing agar with no hormones or kinetin 1.0mg/l and MS basic medium containing gelite and NAA 1.0mg/l were higher for green callus induction. MS medium containing agar and kinetin 1.0mg/l ws highest degree of efficiency for plant regeneration.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.1043-1051
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• 2013

We use a structural vector error correction model of the labor market to investigate the effect of shocks to Korean unemployment. We associate technology, labor demand, labor supply, and wage-setting shocks with equations for productivity, employment, unemployment, and real wages, respectively. Subsequently, labor demand and supply shocks have significant long-run and contemporaneous effects on unemployment, respectively.

• Journal of Fisheries and Marine Sciences Education
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• v.19 no.2
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• pp.310-322
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• 2007

This study is to find ways of support for beginning teacher induction in elementary school with constructing model of professional development. To achieve this purpose, this study reviewed significance of beginning teacher induction program, the bridge to life learning, and constructed the model of professional development for beginning. The final conclusion about ways of support as support intensity are orientation based on demanding of beginning teacher, bridge connection with veteran teacher, coordination of working conditions, collaboration among peer teacher, and strengthening computer network at week intensity level. At strong intensity level, the ways of support for beginning teacher are institutionalization on election and training of mentor, institutionalization on compulsory induction for 1 year, development and operation of teacher education center, and furtherance of school learning organization.