• 무역상무연구
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• 제50권
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• pp.187-212
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• 2011

Third party logistics research is searching for increasing its logistics efficiency of organization. Perspective of resource-based theory, this study is to reveal the exploratory relation between integrated capabilities, organzaiton knowledge, and service performance. To develop the relational model, this study conducted a theoretical survey on Shang(2009)'s 3PL service providers research model and Synder & Cumming(1998)'s learning of organization knowledge. According to the result of correlation analysis, Integrated organization knowledge is positively correlated with service diversity advantage (correlation coefficient= .670, p-value= .000) and service quality advantage (correlation coefficient= .575, p-value= .000). The thesis argued that Korean companies try to apply integrated organization abilities and service performance for cutting their export expense.

• 지식경영연구
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• 제10권2호
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• pp.35-48
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• 2009

The paper proposes a quantitative causal ordering map (QCOM) to combine qualitative and quantitative methods in a framework. The procedures for developing QCOM consist of three phases. The first phase is to collect partially known causal dependencies from experts and to convert them into relations and causal nodes of a model graph. The second phase is to find the global causal structure by tracing causality among relation and causal nodes and to represent it in causal ordering graph with signed coefficient. Causal ordering graph is converted into QCOM by assigning regression coefficient estimated from path analysis in the third phase. Experiments with the prediction model of Korea stock price show results as following; First, the QCOM can support the design of qualitative and quantitative model by finding the global causal structure from partially known causal dependencies. Second, the QCOM can be used as an integration tool of qualitative and quantitative model to offerhigher explanatory capability and quantitative measurability. The QCOM with static and dynamic analysis is applied to investigate the changes in factors involved in the model at present as well discrete times in the future.

• Tribology and Lubricants
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• 제6권2호
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• pp.94-98
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• 1990

The size and concentration of wear debris in lubricating oil often reveal the operating condition of the rotating machinery. To evaluate the possible application of light attenuation measurement for the estimation of wear debris concentration in the lubricating oil, the light transmittance through the lubricating oil cell contaminated with various concentrations of diatomire particles was measured, the attenuation coefficient was estimated from the transmittance measurement and the coefficients were compared with those obtained from the scattering theory. The comparision showed good agreements between them. It is also noted that the experimentally determined attenuation coefficient showed almost linear relation with particle weight coucentrations for the concentrations within the range of 2000 ppm. For the case of 0 ppm weight concentration of diatomire particles in the lubricating oil cell, the thickness of the cell required to give $100 \muW$ light attenuation is 7.75 mm. This result indicates that the light attenuation method will be one of the possible candidates of machine failure diagnostic sensors for the estimation of wear debris concentration in the lubricating oil.

• Tribology and Lubricants
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• 제29권4호
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• pp.242-247
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• 2013

This study aims to establish the fundamental basis for the design of materials used in high-speed trains, by using a lab-scale dynamometer to evaluate the characteristic behavior of metallic sintered friction materials in relation to the shape of graphite. The test results clearly demonstrate that when flake graphite and granular graphite are added equivalently, the average coefficient of friction is much lower, and it is less influenced by speed variation; moreover, friction wear is observed to be insignificantly low. Adding flake graphite increases the coefficient of friction, which leads to higher friction wear. In addition, the roughness of the disc surface was equivalent regardless of the shape of the graphite.

• 한국전자파학회논문지
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• 제17권12호
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• pp.1181-1188
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• 2006

본 논문에서는 토양 표면의 레이더 후방 산란 계수와 표면 거칠기의 관계를 계산해 보고, 측정 길이에 따른 표면 거칠기 변화를 알아본 후에, 측정 길이에 따른 표면 거칠기와 레이더 후방 산란 계수의 관계를 보여준다. 이 연구 결과에 따르면, 측정 길이가 짧아져서 표면 거칠기 값의 변화가 심하다하더라도 계산된 레이더 후방 산란 계수에는 적은 영향밖에 주지 않는다는 것을 보여준다.

• 오토저널
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• 제2권1호
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• pp.32-38
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• 1980

In the case of a automobile marking skid on road for a period of braking, in general, the automobile velocity just before rapid braking can be obtained by evaluating the coefficient of friction between tires and road. Up to now, the coefficient of friction has been derived from mean velocity measured by a time watch, but the automobile velocity obtained in this manner would be deviated from actual value considerably, due to errors arising from not only measuring time but other various factors. In this paper the presumption method of automobile velocity by accelerometer is presented so as to improve the accuracy of measurement, and to determine the velocity readily. The results obtained in this experiment show that the frictional coefficients between tires and road under the given experimental conditions are considered to take linear relation over the fixed velocity limits 30km/h to 50km/h while for the same limits of velocities the coefficients of friction by the time watch method are not valid ar low velocity range. It will be seen that the former is simple and reliable whilst the latter is cumbersome and unreliable.

• 동굴
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• 제15권16호
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• pp.38-60
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• 1987

There are BOD(Biochemical Oxygen Demand) and COD(Chemical Oxygen Demand) in the date of the water pollution in the pollution analysis, BOD and COD analysis the result of the analysis. The computer developed the program in the analysis. Went by BOD, the relation conversion equation type of COD, the control chart, the standard deviation, and the coefficient of correlation etc.. for the purpose of the development of the program. There is a purpose by which it is what coefficient of correlation in the development of this program or not if the value (X and Y) of unknow is understood. In the future, if this program is applied the utilization to not only the data is analyzed about the water pollution but also a lot of fields is proposed.

• Korean Membrane Journal
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• 제6권1호
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• pp.30-36
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• 2004

The gas permeation performance of commercially available polyetherimide (Ultem$\^$/) is simulated by means of molecular dynamics methods. By the observation of trajectory, long distance hopping of gas molecules is needed to transverse from top to bottom of membrane. Two possibilities mechanism of diffusion phenomena through glassy polymers can be issued. Diffusion coefficients were calculated by Einstein relation equation. In solubility simulation, the value of the constants C'$\_$H/ and b for O$_2$ at 300 K were calculated. The diffusion and solubility coefficient of He for PEI were simulated in this simulation work. the permeability coefficient is 9.88 Barrer. This value is closed to experimental value of 9.4 Barrer.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.325-332
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• 2003

The tube structures act like cantilevered box beams and effectively resist lateral loads. In result, they are adopted as a high-rise buildings system. However, the shear lag in tube system prevents the idealized tube behavior such as a cantilevered box beam. Therefore, the studies on shear lag phenomena are necessarily requested. The presented papers are almost studied on framed tube structures and tube in tube structures. However, the study on the shear lag in the tube structure with core wall is lack. Thus, in this paper, the shear lag of the structure is studied. The shear lag coefficient is defined to investigate shear lag phenomena. However, existing shear lag coefficients are not adequate for understanding them. Therefore, on this study, new shear lag coefficient is suggested. In addition, the shear lag in the tube structure with core wall is analyzed by changing the five structural parameters of stiffness factor in frame, stiffness factor in wall, stiffness ratio, the number of stories and the number of bays.

• Journal of the Korean Data and Information Science Society
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• 제17권3호
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• pp.775-784
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• 2006

This study is to investigate the effect of the number of co-rated users to the MAE. User based collaborative algorithm generally uses similarity weight to compute the relation of active user and other users. The original estimation algorithm of the GroupLens used the Pearson's correlation coefficient, soon after other researchers used various weighting. The Pearson’s correlation coefficient and Vector similarity, which is used in the field of information retrieval, are commonly used to the estimation algorithm. In prediction, we analyze the effect of the number of co-rated users on the user based recommender system.