• 한국주조공학회지
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• 제34권4호
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• pp.136-142
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• 2014

Numerical solution of thermal stress by CAE analysis could be an effective method in product development stage of castings to predict and treat the problem of solidification cracking of castings. Quantitative stress-strain data are necessary, in this case. Tension type apparatus of a solidification crack test which can measure stress-strain relationship quantitatively was developed and the test procedure was established by this research. Solidification crack strength obtained from the following test procedure could be utilized to evaluate it in terms of effect factors on thermo-plastic characteristic of solidifying alloy such as grain size of solid, grain morphology, distribution of solid grain, etc. Proposed test procedure is as follow: Prediction of temperature at the failure site of solidification cracked specimen by computer simulation of solidification, Calculation of solid fraction of the failure site from thermodynamic solution of solidification under Scheil condition.

• 한국경영과학회지
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• 제17권2호
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• pp.45-54
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• 1992

It become increasingly important to design user interface to carry low complexity. The cognitive limitations of users severely restrict utility of highly intelligent but complex modern systems. Since humans are known to use schemas to reduce cognitive complexity, imposing good consistency to an interface design that may help that user form useful schemas will provide powerful control over the complexity. This present a research effort to develop a quantitative method for evaluating interface complexity that the user would experience planning his or her course of action. Taking into account the user's potential schemas, a quantitative measure based on information theory was develped to assess the navigational complexity. This approach does not rely on the subjective judgment of the researcher as most schemes dealing with user schemas do. The proposed method may benefit the rapid prototyping approach to design a better user interface by allowing handy assessment of the design.

• Molecules and Cells
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• 제26권1호
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• pp.87-92
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• 2008

We employed dual color Fluorescence Cross Correlation Spectroscopy (FCCS) to measure the interaction between PKA regulatory (RII) and catalytic subunits (CAT) in living cells. Elevation of intracellular cAMP with forskolin decreased the cross-correlation amplitude between RFP-fused RII (RII -mRFP) and GFP-fused CAT (CAT-EGFP) by 50%, indicating that cAMP elevation leads to dissociation of RII-CAT complexes. Moreover, diffusion coefficient analysis showed that the diffusion rate of CAT-EGFP was significantly increased, suggesting that the decreased RII-CAT association caused by cAMP generated free CAT subunits. Our study demonstrates that in vivo FCCS measurements and their quantitative analysis permit one not only to directly quantify protein-protein interactions but also to estimate changes in the intracellular cAMP concentration.

• 설비공학논문집
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• 제12권10호
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• pp.879-885
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• 2000

It is a serious subject for energy conservation to prevent the energy loss caused by mixing of heated and cooled air jets in a building which two types of air-conditioning systems are adopted in perimeter and interior zone. The purpose of this paper is to clarify the quantitative and qualitative mechanisms of the mixing loss and to propose preventive methods for it. In this paper, by using the dynamic heat load calculation method, heat extraction loads of a typical office building in Pusan are calculated. According to the results, numerical simulation based on the computational fluid dynamics were peformed in order to measure the mixing loss in physical size HVAC system. Then, the distributions of air temperature and velocity are analyzed in order to grasp the relations by setting temperature differences influence on the mixing loss.

• 한국시뮬레이션학회논문지
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• 제13권4호
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• pp.17-29
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• 2004

The focus of this study is to represent a methodology of analysis for integrated logistic system by means of the Evolution Strategies and Data Envelopment Analysis(DEA). The integrated logistic system is composed of AS/RS (Automated Storages and Retrieval System), AGVs(Automated Guided Vehicle System) and Conveyor System. We design the simulation alternatives with choosing the qualitative critical factors for the each subsystem. Evolution Strategies is used to optimize the quantitative critical factors and responses of each alternative. DEA is applied to measure the efficiency of the alternatives in order to select the optimal operation efficiency scheme. The method of analysis which combines Evolution Strategies with DEA can be used to analyze the qualitative and quantitative critical factors in the integrated logistic systems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.186-191
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• 2004

Whenever some new measure to promote safety is being considered, one major input into the decision making process is to be some formal assessment of the costs and benefits involved. What levels of safety do many stakeholders believe the railway should deliver? This paper is a contribution to the efforts to answer the question. In this study, under Willing-To-Pay(WTP) based value of preventing a fatality(VPF) approach, we will study how much people are willing to trade off safety against other desirable things, summarize accepted quantitative criteria for safety quantitative criteria for safety decision, describe differences between these criteria and some current risk control actions, and present an outline of work under way to address issues related to cost-benefit analysis(CBA).

• KDI Journal of Economic Policy
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• 제42권1호
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• pp.31-56
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• 2020

Does financial development contribute to economic growth? The literature finds that an expansion in financial resources is useful for economic growth if the degree of financial development is under a certain threshold; otherwise, the expansion is detrimental to growth. Almost every published study, however, considers country-panel data. Accordingly, the results are not directly applicable to the Korean economy. By examining Korean time-series data, this paper finds that there is an inverse U-shaped relationship between the per capita real GDP growth rate and private credit (as a percentage of nominal GDP)-a well-known measure of quantitative financial development, where the threshold is 171.5%. This paper also finds that private credit is positively associated with economic growth if the share of household credit out of private credit is less than 46.9%; otherwise, private credit is negatively associated with economic growth. As of 2016, the ratio of private credit to GDP and the ratio of household credit to private credit are both higher than the corresponding thresholds, which implies that policymakers should place more emphasis on qualitative financial development than on a quantitative expansion of financial resources.

• 한국안전학회지
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• 제5권3호
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• pp.8-26
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• 1990

It is important to have exact information about the contact pressure distribution in the design of connected parts of machines and structures. In previous works, stress analyses on a two body contact problem have been carried out in large numbers. Besides, the measurement of contact stress is important to confirm the adequateness of the theoretical analysis, to verify appropriateness of Hertzian contact theory and to know the practical pressure distribution, but an excellent measuring method con't be found at present. Therefore, a quantitative measurement of contact pressure by means of ultrasonic waves using a normal probe and an angle has been proposed to measure the contact pressure distribution between two rough flat surfaces. At first, in a new proposed calibration method, the relation between mean contact pressure and sound pressure of reflected waves is obtained by using calibration blocks with various surface roughnesses made of the same material as the rectangular section beams And then, this experimental results are compared with the analytical ones, and the utility of this method is discussed.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권1호
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• pp.1-9
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• 2000

In this paper, a design method of fault-tolerance is presented for the nuclear digital control systems composed of software and hardware. As a quantitative design method measure of fault-tolerance, we used Reliability, Availability and Safety. To implement the proposed fault-tolerance, a prototype system has been devised for the digital control systems and a quantitative method of 'Markovian Model' is applied. The results provide the appropriate degree of redundancy and diversity, and fail-safe.

• 전자공학회논문지A
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• 제30A권3호
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• pp.52-60
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• 1993

Fluttering ghost which is the most severs picture impairment in mobile TV reception under multipath fading environments can be detected by measuring the dynamic variation of the synchronizing pulse timing. And also, the occurrence-stucture of fluttering ghost are directly correlated with the multipath parameters. This paper describes the quantitative evaluating method of the mobile TV pictures impaired by multipath parameters by means of the spectral analysis of synchronizing timing fluctuation. The ghost-flutter curve derived from the spatial amplitue spectrum of synchronizing pulse timing fluctuation express well the spatial variation characteristic, and it has been found to be the quantitative evaluating measure of picture impairment in mobile reception. A correspondence between the ghost-flutter curve (and/or index) and picture quality opinion test results is established.