• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.55-60
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• 2004

We have peformed an investigation about the present geodetic VLBI observation problems and a study about the trend of technical development in the future. Especially, I will present the research results about the present status of the technical development and the feasibility for e-VLBI which is recently highlighted.

• 대한가정학회지
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• 제36권11호
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• pp.43-59
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• 1998

The purpose of this study was to analyze the residential preferences, the type of house, the size of living space, and the region for later life and contributing factors to their housing plan. The sample in this study consisted of 572 aged couple living in Korea. Statistics employed for the analysis were frequencies, means, X2test, logit analysis and multiple regression. The results could be summarized as follows. They preferred 31.2 pyung as living space, the single detacted house(81.1%) and living in middle-small cities or rural area. The present living space, present living area, satisfaction of economic status had significant effects on the living space in later life. Those who had a plan to live in the single detached house were affected by husband's educational attaintment, the type of present house, present and future living region. And the factors affecting furture living region were present living region, household income, household expenditure, total asset and preferred housing type. The affecting factors were different from future residential preferences by occupation and health status.

• 한국주거학회논문집
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• 제7권2호
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• pp.29-44
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• 1996

This study investigated the Present traditional Korean farmhousing and Past housing (from 1928~1956) based on a survey of 23 Korean women from Kyongki Province. It was primarily concerned with a Comparison of the present and past housing ; the size and plan of the house and finishing materials of Anbang(The masters bedroom : ondol) and the kind of furniture. lighting and heating in the Anbang. I was also interested in identifying the socio-demographic and physical variables that influenced the housing, past and Present. Bibliographical studios. cultural approaches and field surveys with tape recordings and questionnaires were used to collect the data. The results showed that the former Housing(averag ; 54 years ago) was very poor. Most homes lacked sufficient space. furniture and experienced a shortage of fuel. The most decisive difference from the present was the large family size. It would be beneficial to make a similar study in both the southern and northern regions of Korea.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.290-295
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• 1993

The purpose of the present study is to propose a realistic method to analyze the prestressed concrete members subjected to pure torsion. The present study device a method to realistically take into account the tensile stiffness of concrete after cracking. The effect of biaxial compressive and tensile loading on the compressive and tensile strength of concrete is also taken into account in the present model. The present model can predict not only the service load behavior, but also up to the behavior of ultimate load stages. The comparison of the present theory with experimental data indicates that the proposed model dipicts reasonably well the actual behavior of prestressed concrete members.

• 대한산업공학회지
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• 제24권1호
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• pp.51-59
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• 1998

This paper presents a new present value measure, the dynamic present value, or DPV. DPV takes into account not only the value of the realized cash flow but also that of potential cash flow. The DPV approach enables the analyst to observe differences in the present value of the alternatives every period over the whole time period of interest. This is the most fundamental advantage of the DPV approach over the traditional present value approach in which the present value of the alternatives is evaluated only one particular point of time. The concepts of the realized and potential cash flows are also developed in this paper. These new concepts are found to be useful elements in evaluating economic alternatives.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(1)
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• pp.415-420
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• 1996

The main objective of the present study is to propose a new measure of uncertainty importance based on distributional sensitivity analysis. The new measure is developed to utilize a metric distance obtained from cumulative distribution functions (cdfs). The measure is evaluated for two cases: one is a cdf given by a known analytical distribution and the other given by an empirical distribution generated by a crude Monte Carlo simulation. To study its applicability, the present measure has been applied to two different cases. The results are compared with those of existing three methods. The present approach is a useful measure of uncertainty importance which is based on cdfs. This method is simple and easy to calculate uncertainty importance without any complex process. On the basis of the results obtained in the present work, the present method is recommended to be used as a tool for the analysis of uncertainty importance.

• Structural Engineering and Mechanics
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• 제61권1호
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• pp.49-63
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• 2017

This paper presents an original hyperbolic (first present model) and parabolic (second present model) shear and normal deformation theory for the bending analysis to account for the effect of thickness stretching in functionally graded sandwich plates. Indeed, the number of unknown functions involved in these presents theories is only five, as opposed to six or even greater numbers in the case of other shear and normal deformation theories. The present theory accounts for both shear deformation and thickness stretching effects by a hyperbolic variation of ail displacements across the thickness and satisfies the stress-free boundary conditions on the upper and lower surfaces of the plate without requiring any shear correction factor. It is evident from the present analyses; the thickness stretching effect is more pronounced for thick plates and it needs to be taken into consideration in more physically realistic simulations. The numerical results are compared with 3D exact solution, quasi-3-dimensional solutions and with other higher-order shear deformation theories, and the superiority of the present theory can be noticed.

• Nuclear Engineering and Technology
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• 제36권1호
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• pp.12-23
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• 2004

In the present study a new measurement technique has been developed, which uses an ultrasonic transmission signal in order to identify the vertical two phase flow pattern. The ultrasonic measurement system developed in the present study not only provides the information required for the identification of vertical two phase flow patterns but also makes real time identification possible. Various vertical two phase flow patterns such as bubbly, slug, churn, annular flow etc. have been accurately identified with the present ultrasonic measurement system under atmospheric condition. In addition, the present test apparatus can practically simulate the ultrasonic propagation characteristics under high temperature and high pressure systems. Therefore, it is expected that the present ultrasonic flow pattern identification technique could be applicable to the vertical two phase flow systems under high temperature and high pressure conditions.

• 한국경영과학회지
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• 제13권2호
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• pp.66-71
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• 1988

Let B be present value of some sequence. This paper concerns the maximization of the expected utility of the present value B when the utility function is exponential.

• 한국정보통신학회논문지
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• 제20권6호
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• pp.1163-1170
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• 2016

본 논문은 ISO/IEC 29192-2 경량 암호 표준으로 지정된 초경량 블록암호 알고리듬 PRESENT의 하드웨어 구현에 대해 기술한다. PRESENT 암호 프로세서는 80, 128비트의 마스터키 길이와 ECB, CBC, OFB, CTR의 4가지 운영모드를 지원하도록 설계되었다. 마스터키 레지스터를 갖는 on-the-fly 키 스케줄러가 포함되어 있으며, 저장된 마스터키를 사용하여 평문/암호문 블록의 연속적인 암호/복호화 처리가 가능하다. 경량화 구현을 위해 80, 128 비트의 키 스케줄링 회로가 공유되도록 최적화하였다. 라운드 블록을 64 비트의 데이터 패스로 설계하여 암호/복호화의 라운드 변환이 한 클록 사이클에 처리되도록 하였다. PRESENT 암호 프로세서를 Virtex5 FPGA로 구현하여 정상 동작함을 확인하였다. $0.18{\mu}m$ 공정의 CMOS 셀 라이브러리로 합성을 한 결과, 8,100 gate equivalents(GE)로 구현되었으며, 최대 454 MHz의 클록 주파수로 동작하여 908 Mbps의 처리율을 갖는 것으로 평가되었다.