• Journal of Information Technology Applications and Management
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• 제25권1호
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• pp.67-85
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• 2018

We propose a noise reduced risk aversion index for measuring risk aversion through a laboratory experiment to overcome disadvantages of the multiple pricing list format developed by Holt and Laury (2002). We use randomized multiple list choices with coarser classification and reward weighting, supplement the rank of risk aversion with extra individual characteristics of risk attitude, and construct an index of risk aversion by standardizing the risk aversion ranking with quantile normalization. Our method reduces multiple switching problems that noisy decision makers mistakenly commit in experimental approaches, so that it is free of the framing effect which severely occurred in the HL. Furthermore, the index doesn't utilize any specific utility function or probability weighting, which allows researcher to hold the independence axiom. Since our noise reduced index of risk aversion has many good traits, it is widely used and applied to reveal fundamental characteristics of risk-related behaviors in economics and finance regardless of experimental environment.

• PNF and Movement
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• 제4권1호
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• pp.9-18
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• 2006

Purpose: The purpose of this study was to investigate the effect of Proprioceptive Neuromuscular Facilitation (PNF) applied to the unilateral upper extremity on the muscle activation of contralateral lower extremity. Twenty-two healthy subjects (mean age of 23.7 years) participated in this study. Method : PNF patterns applied on the unilateral upper extremity in all subjects were the flexion/abduction/external rotation and lifting pattern. The hold and appoximation techniques for the irradiation were applied to end range of both patterns. Muscle activations in four patterns were measured in vastus medialis, tibialis anterior, rectus femoris, and gastrocnemius medial muscles of contralateral lower extremity using surface EMG system. Each EMG value in individual muscle was normalized for maximal voluntary contraction. The data were analyzed by one factor analysis of variance with repeated measure test. Result : There were significant differences in the between-subject effect (muscles) and within-subject effect (patterns) in comparison of muscle activation by application of PNF patterns (p<.05). The irradiation led to higher activation in the flexion/abduction/external rotation pattern than that of lifting pattern in all muscles (p<.05). The approximation techniques revealed more activations than these of hold technique in all muscles (p<.05). Conclusion : These results suggest that the application of PNF patterns to the unilateral upper extremity affect on the muscle activation of contralateral lower extremity and increase according to the intensity of resistance. This mechanism of contralateral effect might provide a help to the development of treatment method for the affected side and functional improvement for the patients who have damages of central nervous system or musculoskeletal problems by orthopedic injury.

• 한국통신학회논문지
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• 제34권10A호
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• pp.776-783
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• 2009

본 논문에서는 OFDM과 같은 대용량 무선 전송방식의 베이스밴드단(Baseband) 신호처리 방식 중 직병렬/병직렬 변환기(Serial-to-Parallel/Parallel-to-Serial Converter)를 전류모드(Current-mode) 회로로 구현했을 경우 유효한 설계 기법을 제안한다. 전류모드를 이용한 OFDM(Orthogonal Frequency Division Multiplexing: 직교주파수분할다중)용 아날로그 프리에 변환(FFT) LSI의 병렬 입출력을 담당하는 전류모드 직병렬병직렬 변환기의 홀드모드(Hold mode)의 불필요한 전류를 제거할 수 있다. 이를 통해 전류모드로 구성한 아날로그 신호처리 시스템의 저소비전력을 실현하기 위해 필수적인 새로운 전류모드 직병렬/병직렬 변환기를 제시하고 설계된 칩의 측정결과가 시뮬레이션 결과와 일치하는 것을 확인하였다. 이를 통해 저전력형 대용량 무선통신 시스템의 베이스밴드단 구축이 가능한 전류모드 아날로그 시스템의 구현 가능성을 제시하였다.

• 한국컴퓨터산업학회논문지
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• 제7권4호
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• pp.299-308
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• 2006

최근에 이동 컴퓨팅환경에서 사용자가 이동중에도 정보를 손실없이 빠르게 얻기 위해, 서버에 정보를 복제하여 사용하는 방법이 연구되고 있다. 지금까지는 이동 호스트가 복제 서버에 데이터를 복제하는 방법인 정적 복제 기법(Static Replica Allocation : SRA)기법을 사용하고 있다. 이 기법은 이동 호스트가 셀에 이동하고나서, 복제서버에 데이터를 복제하는 방법이다. <중략>그리고 정적 복제기법을 사용하였을 때와 본 논문에서 제안된 기법을 비교하여, 데이터 접근 비율을 이동성과 셀의 수에 따른 성능을 분석하였다. 그래서 그 결과, 이동 호스트들의 이동성이 낮을 때에는 접근 비용에서, 제시된 기법이 정적 복제 기법보다 5% 낮게 나타났다. 그리고 이동률에 따른 접근비용은 $2%\sim2.5%$ 감소되었음을 알 수 있다. 마지막으로 셀의 수에 따라서, 선택복제기법의 확장성은 1.7%정도 떨어짐을 알 수 있다.

• 한국인구학
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• 제12권1호
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• pp.19-29
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• 1989

It is well known that vital statistics is of great importance as basic data for establishing various range of national policies. Especially, vital statistics is important among demographic information for monitoring and evaluating the population policy, for constructing life table, for making population projection, and for studying various aspects of the society. In principle, the production of vital statistics is based on the registration system. It is, however, still observed that there are some limitations in utilizing fully the registration system due to the inherent problems such as problems in its coverage, accuracies and timeliness. Thus, as an alternative, many countries conduct survey on vital statistics in order to supplement the registration system and obtain in-depth data. Korea is no exception in this aspect. The National Bureau of Statistics carries out the so-called Continuous Demographic Survey. This is a kind of multi-round retrospective survey, covering 32, 000 households and having reference period of one month. The survey has also characteristics of multi-subject sample. Thus, surveys on economic activity status of population, house-hold income & expenditure, and social indicators are together conducted with the same sample. It is, however, found that the survey itself tends to have some quality problems. Especially, the quality problems connected with field data collection are summarized as coverage error, non-response error and response error. Although it is inevitable not to be free from these errors, we should make all our efforts to reduce the errors. The probable schemes pointed out in this paper are as follows : 1) the strengthening formal quality control activities, 2) the review of the survey method, i. e., the combining interview method with mail-sending and mail-back method or pick-up method, 3) well documentation for various cases found in every stage of data collection, and 4) the strengthening the analytical activities. It is, also, emphasized that sincerity of planners and interviewers is the most important factor among other things.

• 대한의생명과학회지
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• 제10권4호
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• pp.495-499
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• 2004

Because the education system that based on objective data is needed for the beginning technologists in the department of medicine laboratory, development of the CAI system based on Gram-Stain images is needed in clinical microbiology field. So, in this study, we implemented CAI system based on Gram-Stain images for medical technologists under Web using multimedia toolbook. Because this system is implemented under Web, more and more beginning technologists can have a remote-education beyond time and space, can save human power and time that needed due to hold in common of educational information, and cannot learn mistaken microbiology images because of learning execution based on objective data. Also, implemented system brings a higher interest and a learning effect to medical technologies because of hyper-media method that offered from toolbook. In the future, it will be needed a continuous acceptance of changing knowledge and it will be useful system for technologist in case of applying various examinations based Gram-Stain method of this study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2528-2530
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• 2000

In general, Diode makes a major role in electronic circuit. For example, switching of rectifier, cross current of switching rectifier, energy transfer of electronic element and reverse charge of capacitor, voltage insulation, energy feedback from load to power supply, and such as recovery of storaged energy. Generally, We regard power diode as ideal element, but it has a certain boundary actually, specially, We use diode for detecting circuit peak hold voltage signal. It has cut in voltage. It occurs error of measurement value namely. This error, below in region diode voltage drop (0.7v) measurement value is wholesome signal, Specially, We can not get precision data. Therefore, precision level is low between theoretical and measurement data because of error in actual circuit. Conclusionally, In this paper, We define the error concerning to the power diode characteristics which is used detecting of the minute signal, and recommend the method that minimize measurement error.

• Journal of Mechanical Science and Technology
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• 제19권11호
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• pp.1975-1987
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• 2005

An input time delay always exists in practical systems. Analysis of the delay phenomenon in a continuous-time domain is sophisticated. It is appropriate to obtain its corresponding discrete-time model for implementation via digital computers. In this paper a new scheme for the discretization of nonlinear systems using Taylor series expansion and the zero-order hold assumption is proposed. The mathematical structure of the new discretization method is analyzed. On the basis of this structure the sampled-data representation of nonlinear systems with time-delayed multi-input is presented. The delayed multi-input general equation has been derived. In particular, the effect of the time-discretization method on key properties of nonlinear control systems, such as equilibrium properties and asymptotic stability, is examined. Additionally, hybrid discretization schemes that result from a combination of the scaling and squaring technique (SST) with the Taylor series expansion are also proposed, especially under conditions of very low sampling rates. Practical issues associated with the selection of the method's parameters to meet CPU time and accuracy requirements, are examined as well. A performance of the proposed method is evaluated using a nonlinear system with time delay maneuvering an automobile.

• 한국조사연구학회지:조사연구
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• 제10권1호
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• pp.113-139
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• 2009

건설경기의 순환적 현상을 분석하기 위해서는 연간조사 통계자료의 속성까지 포함된 월별 벤치마킹 건설지표를 사용하는 것이 바람직할 것이다. 왜냐하면 벤치마킹된 지표는 정확성, 일치성, 비교성, 완전성 등의 측면에서 통계품질이 향상된 것으로 기대되기 때문이다. 이 논문에서는 보다 정확한 것으로 간주되는 연간 단위의 통계자료와 단기변동 특성을 보유한 월간 속보지표를 활용하여 월별 건설지표를 추정하는 벤치마킹 방법들을 연구하였다. 벤치마킹이란 연간통계와 월간통계의 일치성을 보장하면서 두 통계의 단기적 및 순환적 현상과 장기추세를 모두 보유하도록 월간통계를 조정하는 방법이다. 벤치마킹 기법으로는 수치조정 접근방법인 비례배분법, 비례덴톤법, BFL BI 비율법, HP - filter BI 비율법과 모형기반 접근방법인 Chow & Lin 방법, $Fem{\acute{a}}ndez$ 방법을 고려하였다. 또한 실제 통계자료를 가지고 벤치마킹된 건설지표를 추정하였으며, 이러한 벤치마킹 방법들을 실증적으로 비교 평가하였다. 계절적 변동 및 불규칙 변동이 심한 건설지표의 경우에 모형기반 접근방법보다는 수치조정 접근방법이 보다 우수한 것으로 평가되었다. 수치조정 접근방법으로는 가장 널리 쓰이고 있는 비례덴톤법이 무난하지만, 연간통계의 조사오차 또는 측정오차를 감안하면 HP - filter BI 비율법도 고려해 볼 수 있을 것이다.

• 한국기계연구소 소보
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• 통권14호
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• pp.157-168
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• 1985

In cargo vessels, hatch covers are used to prevent sea water from penetrating into the cargo hold and to keep the vessels buoyant. And also they can be used as cargo loading devices as in container ships. In this paper, hatch covers are classified according to their operation method and their characteristics are briefly demonstrated. Systematic description on the scantling of the hatch cover panel and how to determine the capacity of the hydraulic power system fir folding hatch cover panels are also presented. The hydraulic power system is selected from the result of dynamic analysis of the movements of the hatch cover panels when stored on the upper deck. The hatch coaming height is determined as shortly as the hydraulic cylinders can be installed. This study deals with the hatch cover system of the medium sized multi-purpose cargo vessel, but the results of this study can be applied to large-sized cargo vessels with a slight change of the input data in the calculations. Further research on the high pressure pump, hydraulic cleating system and hydraulic piping will realize domestic production of the whole hatch cover system which have been supplied from foreign makers until now