• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.398-399
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• 2006

The procurement of generation and transmission/Distribution capacity in vertically-integrated electric industry is sufficient by facility construction in suitable time. However, the introduction of competitive electricity market increase the efficiency of availability for facilities and fuels. As a result, long-term capacity procurement is required for stable demand-supply balance since it is expected to maintain their generation capacity at a minimum for profit maximization. In this paper, a new long-term capacity procurement mechanism is proposed, which is able to assure supplemental contribution in competitive electricity market.

• 한국공간구조학회논문집
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• 제15권3호
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• pp.103-110
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• 2015

Various hybrid dampers have been developed as increasing tall buildings in Korea. To minimize the installment space and cost, the new hybrid friction damper was developed using friction components. It is composed of two one-nodal rotary frictional components and a slotted bolted frictional connection. Because of these components, hybrid friction damper can be activated by building movements due to lateral forces such as a wind and earthquake. In this paper, displacement amplitude dependency tests were carried out to evaluate on the structural performance and the multi-slip mechanism of the hybrid damper. Test results show that the multi-slip mechanism is verified and friction coefficients are increasing as displacement amplitudes are increasing.

• Journal of Mechanical Science and Technology
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• 제17권2호
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• pp.230-238
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• 2003

In this paper, a three-fingered anthropomorphic robot hand, called SKK Robot Hand 1, is presented. By employing a two-DOF joint mechanism, called Double Active Universal Joint (abbreviated as DAUJ from now on) as its metacarpal joint, the hand makes it possible to mimic humanlike motions. We begin with addressing the motivation of the design and mention how the anthropomorphic feature of a human is realized in the design of SKK Hand I Also, the mechanism of the hand is explained in detail, and advantages in its modular design are discussed. The proposed hand is developed for use as a testbed for dextrous manipulation. It is expected to resolve the increasing demand for robotic applications in unstructured environments. We describe its hardware construction as well as the controller structure including the preliminary results of experiments.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.77-86
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• 2005

In urban areas, new tunnel construction work is often taking place adjacent to existing piled foundations. In this case, careful assessment for the pile-soil-tunnel interaction is required. However, research on this topic has not been much reported, and currently only limited information is available. In this study, the complex pile-soil-tunnel interaction is investigated using the upper and lower bound methods based on kinematically possible failure mechanism and statically admissible stress field respectively. It is believed that the limit theorem is useful in understanding the complicated interaction behaviour mechanism and applicable to the pile-soil-tunnel interaction problem. The results are compared with numerical analysis. The material deformation patterns and strain data from the FE output are shown to compare well with the equivalent physical model tests. Admissible stress fields and the failure mechanisms are presented and used to develop upper and lower bound solutions to assess minimum support pressures within the tunnel.

• 한국안전학회지
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• 제10권4호
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• pp.81-86
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• 1995

In order to apply to analysis methods of mechanism and cross tabulation methods for the influence factors by the accident types to the object of accidents which occurred in R.C and P.C methods among the accidents in construction work sites, the latent hazards in P.C method are evaluated from the data of accidents in H Company from Jan. 1, 1993 to Dec. 31, 1993. The relationship between accident types and unsafe acts, unsafe conditions are recognized and the hazards of R.C method and P.C method are compared from the data acquired by the analysis of causes for a kind of occurrence mechanism. In conclusions, the items such as causes of accidents, accidents types, occurrence time, and the characteristics, are concentrated on one side in the P.C method, which is quite different from R.C method. Therefore the control method for the accident causes is easily established with a lot of effective advantages. The frequency and severity of accidents in P.C method are so low in comparison with R.C method.

• 한국기계가공학회지
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• 제8권4호
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• pp.90-96
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• 2009

The loading condition of actual construction works is complex. The shear effect of mixed-mode load component are crack propagation mechanism in step larger than the crack initial mechanism. Therefore, in this study received a mixed-mode loading on fatigue crack stress ratio on crack propagation path and speed of progress to learn whether stress affects crack propagation. ${\Delta}$ P a constant state of fatigue tests in Mode I, II give the same stress ratio, frequency 10Hz, sinusoidal waveform was used. A lower stress ratio fatigue crack propagation angle is small. This is less affected by the Mode II. Therefore, a mixed-mode fatigue crack propagation is to progress by the Mode. Stress ratio in a mixed mode crack in the path of progress and found a lot of impact.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.115-116
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• 2005

Si nanowires (NWs) were fabricated in vacuum furnace by using a Nd:YAG pulsed laser with the wavelength of 325 nm. Commercial p-type Si wafer is used for target, and any catalytic materials are not used. Scanning electron microscopy (SEM) images indicate that the diameters of Si NWs ranged from 10 to 150 nm. Si NWs have various size and shape with a substrate position inside a furnace, and their morphologic construction is reproducible. The formation mechanism of the NWs is discussed.

• 드라이브 ㆍ 컨트롤
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• 제12권2호
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• pp.14-20
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• 2015

This paper focuses on the issue of force synchronizing control for the injection servomechanism of injection molding machines. Prior to the controller design, a virtual design model was developed for the injection mechanism with an AC servomotor-ball screw. A synchronizing controller is designed and combined with the PID control to accommodate the mismatches between the real plant and the linear model plant used. Due to the plant uncertainty, the stiffness and the damping of the mechanism were considered. From the tracking control simulations based on the virtual design model, it is shown that a significant reduction in force synchronizing error is achieved through the use of a proposed control scheme.

• 한국공간구조학회논문집
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• 제15권4호
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• pp.73-80
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• 2015

The new rotary friction damper was developed using several two-nodal rotary frictional components with different clamping forces. Because of these components, the rotary friction damper can be activated by building movements due to lateral forces such as a wind and earthquake. In this paper, various dependency tests such as displacement amplitude, forcing frequency and long term cyclic loading were carried out to evaluate on the structural performance and the multi-slip mechanism of the new damper. Test results show that the multi-slip mechanism is verified and friction coefficients are dependent on displacement amplitute and forcing frequency except long term cyclic loading.

• Journal of Advanced Marine Engineering and Technology
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• 제23권5호
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• pp.686-692
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• 1999

For the purpose of increasing compressed air pressure higher than 30bar lightening weight and decreasing installation area of air compressor used for shipboard and industrial power plant it is necessary to arrange its cylinders as a w-type or v-type construction multi-stage compression pro-cess more than two stages and to increase its operation speed higher than 1200rpm In this recip-rocating type air compressor operated in high speed having a crank mechanism and complicate cylinder arrangement there is a vibration problems which can be solved by balancing its recipro-cating parts with balance weight and approriate arranging of cylinder's arrangement angles.