• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2135-2140
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• 2004

This study represented experimental research on the flat plate solar collector. For the flat plate Solar system, it is sensitive of the Global radiation. In Actually, it suppose to be dependent on the direct radiation. Also, the existing method's factors are depend upon Global radiation in the flat plate collector system. therefore it needs which is depend upon direct radiation. In this experiment, the flat plate collector is used for obtaining the method's factors of the direct radiation. As a result, the correct $({\tau}{\alpha})_e$ is found out for practical value.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1054-1057
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• 1993

A direct method of fuzzy inference and a fuzzy algorithm with learning function are applied to the steam generator level control of nuclear power plant. The fuzzy controller by use of direct inference can control the steam generator in the entire range of power level. There is a little long response time of fuzzy direct inference controller at low power level. The rule base of fuzzy controller with learning function is divided into two parts. One part of the rule base is provided to level control of steam generator at low power level (0%∼30% of full power). Response time of steam generator level control at low power level with this rule base is shown generator level control at low power level with this rule base is shown to be shorter than that of fuzzy controller with direct inference.

• Kyungpook Mathematical Journal
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• 제60권4호
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• pp.673-682
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• 2020

For the recently defined notion of strongly lifting modules, it has been shown that a direct sum is not, in general, strongly lifting. In this paper we investigate the question: When are the direct sums of strongly lifting modules, also strongly lifting? We introduce the notion of a relatively strongly projective module and use it to show if M = M1 ⊕ M2 is amply supplemented, then M is strongly lifting if and only if M1 and M2 are relatively strongly projective and strongly lifting. Also, we consider when an arbitrary direct sum of hollow (resp. local) modules is strongly lifting.

• 무역학회지
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• 제44권1호
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• pp.143-158
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• 2019

As the overseas direct purchase market grows rapidly, firms are setting up various strategic directions to attract consumers. However, many previous researches on this issue have focused on consumption behavior based on consumers' motivation and demographic factors, so there is a certain limit to suggest practical implications for firms. Therefore, this study proposed modeling to understand how firm's strategic direction influences consumers' acceptance behavior in order to overcome these limitations. For this purpose, this study conducted a survey on 357 domestic consumers and conducted empirical analysis through structural equation model analysis. As a result, the effort expectancy of overseas direct purchase site has a strong influence on consumer intention as much as performance expectancy. We also found that product variety had the strongest impact on performance expectancy and that web site reputation directly affected consumers' behavioral intention as well as purchasing behavior.

• Archives of Metallurgy and Materials
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• 제64권3호
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• pp.841-844
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• 2019

Poppet valves made from high-frequency heat-treated SUH3 steel have insufficient durability, and scratches appear on the valve face in prolonged use. It is necessary to develop surface treatment technology with excellent durability to prevent the deterioration of engine performance. Therefore, a surface treatment technology with higher abrasion resistance than existing processes was developed by direct metal deposition to the face where the cylinder and valve are closed. In this study, heat pretreatment and deposition tests were performed on three materials to find suitable powders. In the performance evaluation, the hardness, friction coefficient, and wear rate were measured. Direct metal deposition using Inconel 738 and Stellite 6 powders without heat pretreatment were experimentally verified to have excellent durability.

• 한국유기농업학회지
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• 제21권4호
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• pp.523-538
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• 2013

To help improve the current government practice of direct damage-compensation policies, resulting from the loss of profit, sustained by Hanwoo farmers, as a result of the recent Korea-U. S. Free Trade Agreement (FTA), this research aims to examine any problems or issues caused by said policies. To accomplish this task, we have established Hanwoo-SIMO model and estimated the damage of Hanwoo farmers, one without the implementation of the FTA and another with the FTA, to compare and contrast the two. We then analyzed the efficacy of the current government policies. According to our analysis, the current direct compensation policies for the loss of profit on the part of Hanwoo farmers are insufficient. To address this problem, we recommend the government enact a new direct damagecompensation law to address the following issues. First, as the base formula of damage-compensation, the government should use current price of the beef rather than the annually changing flexible price. Second, the flexible control index should remain fixed at 1.0 rate while the government prepares the adequate amount of the damage compensating direct payment resulting from the FTA. Third, the direct government compensation policy should extend beyond the current 15 years (2013-2026) as the profit loss is expected to increase after the midpoint of the FTA.

• 대한기계학회논문집A
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• 제21권1호
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• pp.144-153
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• 1997

The determination of the direct kinematics of the parallel mechanism is a difficult problem but has to be solved for any practical use. This paper presents the efficient formulation of the direct kinematics for double parallel robot arm. The robot arm consists of two parallel mechanism, which generate positional and orientational motions, respectively. These motions are decoupled by a passive central axis which is composed of four revolute joints and one prismatic joint. For a set of given lengths of linear actuators, the direct kinematics will find the joint displacements of th central axis from geometric constraints in each parallel mechanism. Then the joint displacements will be converted into the position and the orientation of the end effector of the robot arm. The proposed formulation is decoupled and compacted so that it will be implemented as a real-time direct kinematics. With the proposed formulation, we analyze the motion of the double parallel robot and show its characteristics. Specially, we investigate the workspace in terms of positional space as well as orientational space.

• Computers and Concrete
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• 제18권1호
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• pp.39-51
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• 2016

This paper considers the tensile strength of concrete samples in direct, CTT, modified tension, splitting and ring tests using both of the experimental tests and numerical simulation (particle flow code 2D). It determined that which one of indirect tensile strength is close to direct tensile strength. Initially calibration of PFC was undertaken with respect to the data obtained from Brazilian laboratory tests to ensure the conformity of the simulated numerical models response. Furthermore, validation of the simulated models in four introduced tests was also cross checked with the results from experimental tests. By using numerical testing, the failure process was visually observed and failure patterns were watched to be reasonable in accordance with experimental results. Discrete element simulations demonstrated that the macro fractures in models are caused by microscopic tensile breakages on large numbers of bonded discs. Tensile strength of concrete in direct test was less than other tests results. Tensile strength resulted from modified tension test was close to direct test results. So modified tension test can be a proper test for determination of tensile strength of concrete in absence of direct test. Other advantages shown by modified tension tests are: (1) sample preparation is easy and (2) the use of a simple conventional compression press controlled by displacement compared with complicate device in other tests.

• 한국염색가공학회지
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• 제14권2호
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• pp.94-94
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• 2002

A number of studies have been introduced on the use of quaternary cationic agents having various reactive groups, which can improve the substantivity of anionic dyes, specially direct dyes, towards cotton. In the case of direct dyes, it is well known that they are widely used due to their convenience to apply and low cost, whilst they display poor levels of fastness properties to washing. Thus many applications using direct dyes in the textile fields have been still enjoyed in the areas where a higher level of wet fastness is specially not required. This work herein comprises that in order to improve the substantivity of direct dyes towards cotton, cellulose-reactive allylamine polymer namely, triazinyl N,N′-dimethyl-N,N′-diallyl ammonium chloride was prepared and treated onto cotton to provide cationic properties within substrates. This application showed that even low concentration of electrolytes being present, the direct dyes were exhausted well on the cationized cotton and that the rate of dye uptake by treated cotton was faster than that of untreated sample. Furthermore the antimicrobial properties were observed from the cationized samples.

• 보건행정학회지
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• 제8권2호
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• pp.88-109
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• 1998

The main purpose of this study is to compare the traditional cost system and ABC(Activity Based Cost) system of clinical laboratory department in a hospital. The study subject was 296 services in clinical laboratory from March, 1997 to August, 1997. In a new costing system, cost for a lab test consist of direct cost element, activity based cost element, and allocated common cost element. In a traditional cost system, cost elements included direct cost element and indirect cost allocated based on test volumes The major findings of this research were as follows. 1. In the application of ABC system, total cost was analyzed as follows. Direct cost was 39.3% of total cost. Activity cost and allocation were 20.9% and 39.8%, respectively. The results of analysis to use traditional cost system were as follows. Direct cost was 39.3% and it was as same as the result of direct cost of ABC system. Indirect cost was 60.7%. 2. Activities of clinical laboratory of subject hospital were registration, pre-test operation, test, test result handling, delivery, culture, post-test operation, technical support, management support, and educational support. 3. The differences of the case of higher number of test case being carried out, the cost of ABC system was lower than the cost of traditional cost system. Otherwise in the case of lower number of test case being carried out, the rests have not been appropriately evaluated, and effective management were needed in clinical laboratory.