• 콘크리트학회논문집
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• 제18권5호
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• pp.639-648
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• 2006

전단 경간비를 실험 변수로 하여 철근콘크리트 보에 대한 1방향 단조재하의 전단실험을 실시하였다. 실험에 병행하여 실시한 유한요소 해석과 실험결과를 기초로 전단 경간비가 작은 보의 전단내력을 구하는 해석 방법과 주근의 부착작용의 효과를 고려한 crooked main strut과 sub strut으로 구성되는 새로운 매크로 모델을 제안하였다. 그 결과 전단 경간비가 0.75 이하에서 본 연구에서 제안한 매크로 모델이 형성 가능하다는 것과 콘크리트 압축강도의 유효계수를 0.75로 하였을 때 실험 결과와 해석 결과가 가장 잘 일치함을 확인하였다.

• 동력기계공학회지
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• 제20권3호
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• pp.57-63
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• 2016

This paper presents the experimental result and theoretical analysis result to investigate the correlation between the operating force, angle and locking torque for vehicle hood frame. Also, we derived the experimental equation that using the results for experiment and theory. The hood frame is switching-devices used for opening and closing the vehicle hood. It needs the correlation data between locking torques of each joint, operating force and angle of hood frame. The correlation data for torque and reaction force of hood frame obtained through experiment and theory analysis. Finally, the experimental equation of the locking torque prediction for the hood frame is derived.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 1997년도 제8회 학술강연회논문집
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• pp.43-51
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• 1997

Steady and unsteady numerical simulations are conducted for the experiments performed to investigate the ram accelerator flow field by using the expansion tube facility in Stanford University. Navier-Stokes equations for chemically reacting flows are analyzed by fully implicit and time accurate numerical methods with Jachimowski's detailed chemistry model for hydrogen-air combustion involving 9 species and 19 reaction steps. Although the steady state assumption shows a good agreement with the experimental schlieren and OH PLIF images for the case of $2H_2$+$O_2$+$17N_2$, it fails in reproducing the combustion region behind the shock intersection point shown in the case of $2H_2$+$O_2$+$12N_2$, mixture. Therefore, an unsteady numerical simulation is conducted for this case and the result shows all the detailed flow stabilization process. The experimental result is revealed to be an instantaneous result during the flow stabilization process. The combustion behind the shock intersection point is the result of a normal detonation formed by the intersection of strong oblique shocks that exist at early stage of the stabilization process. At final stage, the combustion region behind the shock intersection point disappears and the steady state result is retained. The time required for stabilization of the reacting flow in the model ram accelerator is found to be very long in comparison with the experimental test time.

• 한국과학교육학회지
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• 제16권3호
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• pp.227-238
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• 1996

This study primary aim is to investigate students' responses to experimental results which conflict with their preconceptions regarding electrical circuits. Eighty-eight students of both sexes were randomly selected from a science high school in Korea. They were questioned about their preconceptions regarding an electric circuit, and sixty-eight students with relevant misconceptions were selected. These students were presented with experimental results obtained by some other experimenter, and asked to interpret these results. The second aim of this study is to explore how students' responses vary according to the type of inquiry-skills required to obtain the result. To do this, two type of experimental results were developed: one obtained by observation and the other obtained by controlling variables. We found that many students doubted results for the simple reason that they conflicted with their preconceptions. They rejected results by mentioning other factors which could have affected the result, or simply by reiterating their preconceptions. This behaviour varied considerably by inquiry-skill type. 41% of students rejected conflictual result obtained by observation, but only 6% of students rejected results obtained by controlling variables.

• 설비공학논문집
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• 제12권10호
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• pp.894-900
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• 2000

The experimental study for performance improvement of aluminum/freon22 grooved heat pipe was carried out. Arterial wick was used for performance improvement of heat pipe. The experimental result was compared with screen covered grooved wick heat pipe. And also, performance test of grooved wick thermosyphon inserted straight wire in the center of grooved pipe was carried out. This result was compared with the performance test result of grooved wick thermosyphon. The operation limit of artery inserted grooved heat pipe was slightly extended, but thermal resistance of this heat pipe was twice as large as that of screen covered grooved heat pipe. In case of thermosyphon, the operation limit of grooved thermosyphon inserted straight wire in the center of grooved pipe was slightly extended, but thermal resistance was increased, comparing with that of the grooved thermosyphon.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.815-817
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• 2004

This paper deals with the characteristics analysis and experiments of operating actuator for automatic door operated by fire detecting sensor. The dynamic characteristics of operating actuator system are analyzed on the structure of the operating actuator model. Simulation and experimental result have been performed for the verification of the proposed system and dynamic characteristics applied to a actuator by electromechanical energy conversion theory. The experimental result have been compared with proposed theoretical predictions. In this experimental result represented the temperature T1 and T2 which remarks T1 is a circumstance of operating actuator system, and T2 is a fire detecting sensor part.

• 한국생활과학회지
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• 제23권6호
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• pp.1035-1048
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• 2014

The purpose of this research is to verify the effect of a 3-year-old's green growth education knowledge of environmental conservation and eco-friendly attitude. This study conducted a survey of 2 classes of 3-years-old children (totaling 45 children) located in Gyeonggi Province Shiheung. The experimental group consisted of 23 children while the comparison group was comprised of 22 children. Experimental treatment period was 5 primarily by the classroom teacher in the experimental group and 12 sessions going green growth program was compared to a group, the basic curriculum was operate as usual. The results of this research are summarized as follows. First, the result of the experimental group, which participated in green growth and did not participate in the control group, show that the early childhood of the experimental group has been improved about knowledge of environmental conservation and showed a statistically significant difference. Second, the result of the experimental group which participated in green growth show that the attitude of the experimental group improved an infant's environment-friendly conscience.

• 복식문화연구
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• 제17권4호
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• pp.616-625
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• 2009

With suffering financial crisis in 1997, Korea's fashion market has grown in the direction that satisfies the reasonable price and diverse consumer's sensitivity and needs. The aim of this study is to examine whether the cutting portion in the waist line is surely necessary for designing the jacket pattern in men's wear, by closely examining the effects of the cutting portion in the waist line on the external appearance and functionality given designing the jacket pattern in men's wear for the standard body type in 20s. The results of the study are as follows. As a result of evaluating the external appearance, when having evaluated by dividing into 14 items such as the whole surface, the side, and the back side, the experimental clothing, which wasn't cut the waist line, obtained the highest mark in 13 items and, the significant difference was indicated in 10 items except 4 items. As a result of evaluating performance, the experimental clothing, which wasn't cut the waist line, obtained the highest mark in 13 items among 25 items in the total. Next, the cutting portion in the waist line obtained the highest mark in 10 items for the experimental clothing with opening in 1.0cm. The next was indicated to be in order of the experimental clothing with 1.5cm and the experimental clothing with 0.5cm. Given seeing the above result, the cutting portion in the waist line given designing the jacket pattern for the standard body type in 20s could be known that the experimental clothing with the most excellent mark in the evaluation of performance was all the experimental clothing with 0.0cm whose waist line wasn't cut.

• 한국정밀공학회지
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• 제16권4호통권97호
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• pp.57-63
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• 1999

A thin metal plate such as detent spring has the shape deformation due to the phenomenon of spring back after press machining and heat treatment process. This requires the correction of spring shape and force in final inspection process. To do correction of the shape deformation the impact force is manually applied to the bended part of detent spring after measuring the shape deformation and spring force. To develop the automatic spring force correction system, applied force of occurring plastic deformation must be derived from the experimental method. But frequent change of spring shape and material makes it difficult to accomplish the experimental method to be applied. This paper describes the analytical method for detent spring force correction system is to be substituted for the experimental method. FEM(Finite Element Method) is used to find the boundary value between elastic and plastic deformation in the analytical method. To confirm the validity of the analytical method, the result of two methods is compared each other at various applied force conditions. It shows that the simulation result of the analytical method is consistent with the result of the experimental method within the error bound ${\pm}$5%. The result of this paper is useful for development of the automatic spring correction system and reduction of the complicated and tedious processes involved in experimental method.

• Steel and Composite Structures
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• 제19권2호
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• pp.417-439
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• 2015

Many methods are developed for strengthening of reinforced concrete structural members against the effects of shear. One of the commonly used methods in recent years is turned out to be bonding of fiber reinforced polymers (FRP). Impact loading is one of the important external effects on the reinforced concrete structural members during service period among the others. The determination of magnitude, the excitation time, deformations and stress due to impact loadings are complicated and rarely known. In recent year impact behavior of reinforced concrete members have been researched with experimental studies by using drop-weight method and numerical simulations are done by using finite element method. However the studies on the strengthening of structural members against impact loading are very seldom in the literature. For this reason, in this study impact behavior of shear deficient reinforced concrete beams that are strengthened with carbon fiber reinforced polymers (CFRP) strips are investigated experimentally. Compressive strength of concrete, CFRP strips spacing and impact velocities are taken as the variables in this experimental study. The acceleration due to impact loading is measured from the specimens, while velocities and displacements are calculated from these measured accelerations. RC beams are modeled with ANSYS software. Experimental result and simulations result are compared. Experimental result showed that impact behaviors of shear deficient RC beams are positively affected from the strengthening with CFRP strip. The decrease in the spacing of CFRP strips reduced the acceleration, velocity and displacement values measured from the test specimens.