• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.360-363
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• 2007

센서 네트워크에서 신뢰성 높은 데이터 전송에 대한 중요성이 증가하고 있다. 노드와 싱크로 구성된 센서 네트워크에서, 노드에서 싱크로의 통신은 어느 정도 에러 발생에 민감하지 않으나 싱크에서 노드로의 통신은 관리 및 제어에 대한 메시지 전송이기 때문에 에러 발생에 아주 민감하다. 본 논문에서는 에러에 민감한 전송 영역인 싱크에서 노드로의 통신에 중점을 두고 에러 복구에 대한 기법을 제시한다. 신뢰구간을 end-to-end가 아닌 hop-by-hop으로 형성하여 에러가 발생하거나 데이터 손실이 일어나는 경우 고정 윈도우를 사용하는 선택적 응답으로 에러 복구를 한다. 추가로, 각 노드의 버퍼 상태에 따른 트래픽 혼잡 제어를 지원한다. 시뮬레이션을 통해, 제시하는 기법이 센서 네트워크에서 에러 복구에 우수한 성능을 가짐을 보인다.

• 한국정보통신학회논문지
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• 제11권6호
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• pp.1190-1194
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• 2007

센서 네트워크에서 신뢰성 높은 데이터 전송에 대한 중요성이 증가하고 있다. 노드와 싱크로 구성된 센서 네트워크에서, 노드에서 싱크로의 통신은 어느 정도 에러 발생에 민감하지 않으나 싱크에서 노드로의 통신은 관리 및 제어에 대한 메시지 전송이기 때문에 에러 발생에 아주 민감하다. 본 논문에서는 에러에 민감한 전송 영역인 싱크에서 노드로의 통신에 중점을 두고 에러 복구에 대한 기법을 제시한다. 신뢰구간을 end-to-end가 아닌 hop-by-hop으로 형성하여 에러가 발생하거나 데이터 손실이 일어나는 경우 고정 윈도우를 사용하는 선택적 응답으로 에러 복구를 한다. 추가로, 각 노드의 버퍼 상태에 따른 트래픽 혼잡 제어를 지원한다. 시뮬레이션을 통해, 제시하는 기법이 센서 네트워크에서 에러 복구에 우수한 성능을 가짐을 보인다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1702-1707
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• 2007

The reduction of pipe-thickness induced by flow accelerated corrosion (FAC) is one of the most serious problems on the maintenance of piping system in nuclear power plants (NNP). If the thickness of a pipe component is reduced below the critical level, it cannot sustain pressure and consequently results in leakage or rupture. For this reason, wall thinning by FAC has been inspected in secondary side piping systems in NPPs. In this research Round Robin Test (RRT) was conducted to verify confidence of wall thinning measurement system in NPP. 12 inspectors from 3 companies participated and 23 specimens were used according to standard practice in RRT. The gage R&R analysis was introduced in regard to repeatability and reproducibility that are affected to measurement system errors. Confidence intervals of thickness measurement system were obtained.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1898-1904
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• 2001

Measurement uncertainty should be evaluated according to ISO/IEC 17025. In Flow measurement area, uncertainty evaluation scheme was applied to the reference flow meter, sonic nozzle. Uncertainty was calculated by evaluating various uncertainty factors affected in flow measurement. The expanded uncertainty(U) of the sonic nozzle was 2.1$\times$ 10$^{-3}$ (confidence level of 95 %). This evaluation example will be useful in flow measurement uncertainty determination of other flow meters.

• 디지털융복합연구
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• 제17권6호
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• pp.381-388
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• 2019

본 연구는 자신감의 뜻을 정의하고 디자이너에게의 창의력의 중요성을 알아본 후 두 요소 사이에 상관관계가 있는지를 찾는 것을 목표로 하였다. 좋은 디자인에는 새로운 발상이 요구되므로 창의력은 디자인 프로세스에 중요한 요소이이며, 많은 이들이 자신감이 창의력을 키워준다고 믿는다. 설문조사와 창의력 테스트를 동반한 실험결과 두 요소 사이에 뚜렷한 상관관계가 없는 것으로 나타났다. 하지만 두 요소가 누군가의 동기부여에 결정적인 역할을 해 디자이너로서의 성공에 관여한다는 것은 변함없는 사실이다.

• The Journal of Asian Finance, Economics and Business
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• 제7권5호
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• pp.19-29
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• 2020

The paper examines the impact of information about cash flow from operating activities of firms listed on Vietnam's stock market to the decision making of individual investors. Data were collected from interviews with 160 individual investors about their investment decisions based on information on profit growth and cash flow growth from operating activities. T-test was conducted to research on Vietnam's stock market - a market considered as information that is not really public, transparent and ineffective. The research results show that: (1) investors do not care about cash flow from operating activities when making investment decisions if the company's profits grow positively, (2) information about cash flow from operating activities only affects the decisions of individual investors once profit growth is negative, and (3) conflicting information between profit growth and cash flow growth from business activities significantly affects the confidence and comfort of investors in Vietnam's stock market when they make investment decisions. Then, the study points out the mistake of investors when making investment decisions, and offers recommendations to investors when making investment decisions, not only concerned with profit growth, but also paying special attention to cash flow growth, especially cash flow from the company's business operations.

• The Journal of Asian Finance, Economics and Business
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• 제7권6호
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• pp.85-93
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• 2020

The paper investigates the impact of the statement of cash flows of listed companies on lending decisions of commercial banks in the context of Vietnam. Survey data for the research were collected from 160 credit officers of Vietnamese commercial banks for short-term and long-term lending decisions, whether the cash flow statement includes complete information or has a lack of information. The cash flow statement, in which the information on the cash flow is completely contrary to the profit information on the income statement is examined. This paper employed T-tests to address the research issues in a market considered to be ineffective, like Vietnam. The research results show: (1) the information on the cash flow statement affects both the short-term and long-term lending decisions of credit officers, and (2) the lack of information on the cash flow statement in both cases of positive and negative profits affects the comfort and confidence of credit officers in making decisions. The research findings also indicate that cash flow statements are important for lending decisions of credit institutions in Vietnam. Therefore, this paper provides a new insight to managers on how to improve the quality of cash flow statement to meet the needs of lenders.

• 한국유체기계학회 논문집
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• 제6권2호
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• pp.47-53
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• 2003

The piston prover was developed and the flow measurement uncertainty of this piston prover was evaluated according to ISO/IEC 17025. The laser interferometer, instead of the optical sensors used in the typical provers, was employed in this prover to measure accurately the testing time and the moved distance of the piston. Uncertainty was calculated with evaluation of various uncertainty factors affecting flow measurement. The expanded uncertainty (U) of the piston prover was $1.3{\times}10^{-3}$ (at the confidence level of $95\%$). This evaluation example will be useful in the flow measurement uncertainty determination of other gas flow measurement system.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제11권2호
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• pp.63-71
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• 2005

The purpose of this study is to find the complementary idea of the psychological elements in aesthetic expression of architectural space in the sense of healing. Marks $L\ddot{u}scher$, the swiss psychologist suggested reasonable categories of emotional character according to the couple combinations among Content, Self-Esteem, Confidence, and Liberty. His theory on healing is not only the concept but the practical method to understand and control the conflict between contrary elements of emotion. Compared to the Freud's objective theory of cause and consequence, his idea is focused on the subjective and autonomous harmony. This theory based on complementary idea is applied to psychological attitude of architects on Spatial Expression in this study. Refuge, Prospect, Flow and Void are assumed as equivalent spatial elements to the four major emotional conditions suggested by $M.L\ddot{u}scher$. The couple combinations among them also characterize the architectural characters definitely and it is expected to be the reasonable criteria in analysing aesthetic value and motive of creating human space.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.735-739
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• 2005

This paper presents a new system to estimate the head pose of human in interactive indoor environment that has dynamic illumination change and large working space. The main idea of this system is to suggest a new morphological feature for estimating head angle from stereo disparity map. When a disparity map is obtained from stereo camera, the matching confidence value can be derived by measurements of correlation of the stereo images. Applying a threshold to the confidence value, we also obtain the specific morphology of the disparity map. Therefore, we can obtain the morphological shape of disparity map. Through the analysis of this morphological property, the head pose can be estimated. It is simple and fast algorithm in comparison with other algorithm which apply facial template, 2D, 3D models and optical flow method. Our system can automatically segment and estimate head pose in a wide range of head motion without manual initialization like other optical flow system. As the result of experiments, we obtained the reliable head orientation data under the real-time performance.