• 대한정형도수물리치료학회지
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• 제25권2호
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• pp.65-72
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• 2019

Background: The purpose of this study was to investigate into the effects of physical therapy intervention with local vibration on pain, ROM (range of motion) and psychological status in multiple trauma patients caused by traffic accident. Methods: A patient with multiple trauma were recruited. Before treatment, he was evaluated using numeric pain rating scale (NPRS), Korean-version impact of event scale-revised (IES-R-K), Beck Depression inventory (BDI), passive and active range of motion, and were reevaluated after 4 and 8 weeks of treatment. Results: As a result of comparing the participant before and after the experiment, the score of the IES-R-K and BDI decreased. And the passive and active ROM increased. Conclusion: According to the results above, physical intervention with local vibration by Blackroll Releazer can help improve pain, physical function and psychological status. Also, physical intervention with Blackroll's Releazer technique was able to select interventions depending on the patient's conditional and the desired goal.

• 한국디지털건축인테리어학회논문집
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• 제13권4호
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• pp.69-76
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• 2013

As the energy consumed in building area has occupied a lot when looking into energy usage weights in area over the world, energy reduction building, eco-friendly architecture comes to the fore in the modern architecture. Discussions on the eco-friendly architecture have various concept definitions and targets to be achieved.The architectural works of Norman Foster are expressed as high-tech buildings using iron, glass, etc. in appearance, but they appear as those buildings with low energy load by analyzing environmental conditions from initial design stage that each building has, utilizing natural energy with design of outer shell and applying proper technical system. Thus, this study aims at providing basic data of outer shell planning through eco-friendly element technologies by considering pattern and outer shell design of buildings, principles of eco-friendly building plan as an eco-friendly building planning technique of Norman Foster as an example of plans to utilize building pattern, outer shell design and natural environments, in order to utilize passive measures as much as possible to increase energy saving methods and increase comfort by analyzing element technologies in the eco-friendly architecture in line with the modern flow.

• 대한전자공학회논문지TE
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• 제42권4호
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• pp.1-6
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• 2005

최근 저항이나 캐패시터와 같은 수동소자를 PCB의 내층에 제조하는 임베디드 패시브 기술이 고성능의 IT 제품을 제조하는데 사용되고 있다. 그런데 임베디드 캐패시터는 정전용량 밀도가 낮아 회로소자로서의 전반적인 응용에 한계가 있다. 본 논문에서는 이러한 한계를 극복하기 위하여 wrinkle형의 전극과 유전체 층을 가진 새로운 임베디드 캐패시터를 제안하였다. FEM 기법을 사용하여 wrinkle형 임베디드 캐패시터의 정전용량 밀도를 평가하였다. Wrinkle형 임베디드 캐패시터는 기존의 평면형 임베디드 캐패시터에 비하여 25.6%$\sim$39.6% 정도 큰 정전용량 밀도를 나타내었다. 특히, thin film형 임베디드 캐패시터에 wrinkle 구조를 적용할 때 정전용량 밀도가 보다 많이 향상되었다.

• 한국건축시공학회지
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• 제4권2호
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• pp.105-112
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• 2004

The objective of this study is to observe today's situation and direction in relation with the natural air-conditioning and heating system to expand the architectural utilization of natural management for human comfort and energy conservation in architectural design. Also this study to provide the fundamental knowledge and. design-techniques on environment-friendly architecture in connection with 'natural idea in architecture'. In accordance with this intention, this thesis is composed of the following contents : 1) to understand the fundermental concepts about natural air-conditioning and heating system, 2) to review the traditional characteristics in Korean and Southeast Asian architecture related to natural air-conditioning and heating system, 3) to examine modern design-techniques in relation with natural air-conditioning and heating system in the selected area, 4) to attempt to synthesize the whole situation. Environment-friendly architecture using natural ideas and design-techniques in architecture is very important architectural aspect in a current architecture, also for the future. In spite of general considerations, it is expected that this study is use to understand the principle and practical application of natural air-conditioning and heating system in architectural design.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.59-63
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• 2011

Friction damping is one of the attractive vibration control technique for space structures due to its simplicity and large damping capacity. However, passive approaches for friction damping have a limitation because energy is no longer dissipated at sticking. In order to overcome this problem, semi-active control methods to adjust normal force at frictional interface have been studied in previous researches. In this paper, two semi-active friction control method is compared by simulating SDOF model of truss structure. The first approach is on-off control to maximize rate of energy dissipation, whereas the second concept is variable friction force control to minimize amplitude ratio for each half period. The maximum friction force, control variable in on-off control method, is obtained to minimize 1% settling time, and is different from optimal friction force in passive control. Simulation results show that performance of on-off control is better than that of variable friction force control in terms of settling time and controlled friction force.

• 대한기계학회논문집A
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• 제31권2호
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• pp.152-159
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• 2007

A study on the control of free vibration and stability characteristics of rotating hollow circular shafts subjected to compressive axial forces is presented in this paper. Both passive structural tailoring technique and active control scheme via collocated piezoelectric sensing and actuation are used in the study Gyroscopic and centrifugal forces combined with the compressive axial force contribute to the occurrence of divergence and flutter instabilities of the rotating shaft. The dual methodology based on the passive and active control schemes shows a high degree of efficiency toward postponement of these instabilities and expansion of the domain of stability of the system. The structural model of the shaft is based on an advanced thin-walled beam structure that includes the non-classical effects of transverse shear, anisotropy of constituent materials and rotatory inertia.

• 대한전자공학회논문지TC
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• 제45권12호
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• pp.128-132
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• 2008

본 논문에서는 LTCC(low temperature co-fired ceramic) 공정을 이용한 삽입된 수동 소자들을 갖는 필터 설계를 하였다. 우수한 성능과 소형화를 위해서 제안된 적층 구조의 기생 성분들은 제안된 회로 변환 과정을 통해 전체 필터 회로에서 긍정적인 효과를 갖도록 하였다. 그 결과 소형화된 저역 통과 필터는 다른 논문들의 소형화된 구조들에 비해 50프로 이상의 적은 두께를 갖을 뿐만 아니라 0.5 GHz와 5 GHz 사이에서 이상적인 저역 통과 필터의 응답을 보였다.

• Corrosion Science and Technology
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• 제19권3호
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• pp.156-162
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• 2020

The objective of this study was to investigate delayed oxygen evolution and localized corrosion resistance of titanium alloys by performing potentiodynamic polarization, potentiostatic polarization, and Mott-Schottky measurements. Delayed oxygen evolution was compared among titanium alloys, 316 stainless steel, and platinum. Difference in delayed oxygen evolution between titanium alloys and other metals was attributed to specific surface characteristic of each metal. Delayed oxygen evolution of titanium alloys resulted from the predominant process of ionic conduction over electronic conduction. The effect of oxygen evolution on localized corrosion of titanium alloys was investigated using electrochemical critical localized corrosion temperature (E-CLCT) technique. Mott-Schottky measurement was performed to clarify the difference in film properties between titanium alloys and stainless steels. Titanium alloys were found to have much lower donor density than stainless steels by 1/28. These results indicate that delayed oxygen evolution has little influence on the concreteness of passive film and the resistance to localized corrosion of titanium alloys.

• Earthquakes and Structures
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• 제13권1호
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• pp.51-58
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• 2017

Passive dynamic vibration absorbers (DVAs) are often used to suppress the excessive vibration of a large structure due to their simple construction and low maintenance cost compared to other vibration control techniques. A new type of passive DVA consists of two pendulums connected with spring and dashpot element is investigated. This research evaluated the performance of the DVA in reducing the vibration response of a two degree of freedom shear structure. A model for the two DOF vibration system with the absorber is developed. The nominal absorber parameters are calculated using a Genetic Algorithm(GA) procedure. A parametric study is performed to evaluate the effect of each absorber parameter on performance. The simulation results show that the optimum condition for the absorber frequencies and damping ratios is mainly affected by pendulum length, mass, and the damping coefficient of the pendulum's hinge joint. An experimental model validates the theoretical results. The simulation and experimental results show that the proposed technique is able be used as an effective alternative solution for reducing the vibration response of a multi degree of freedom vibration system.

• Journal of Electrical Engineering and Technology
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• 제3권2호
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• pp.152-161
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• 2008

This paper deals with a new wave shaping technique for cost effective harmonic mitigation in ac-dc converter feeding Vector Controlled Induction Motor Drives(VCIMD's) for improving power quality at the point of common coupling(PCC). The proposed harmonic mitigator consists of a polygon connected autotransformer based twelve-pulse ac-dc converter and a small rating passive shunt filter tuned for $11^{th}$ harmonic frequency. This ac-dc converter eliminates the most dominant $5^{th},\;7^{th},\;and\;11^{th}$ harmonics and imposes the reduction of other higher order harmonics from the ac main current, thereby improving the power quality at ac mains. The design of autotransformer is carried out for the proposed ac-dc converter to make it suitable for retrofit applications, where presently a 6-pulse ac-dc converter is used. The effect of load variation on VCIMD is also studied to demonstrate the effectiveness of the proposed ac-dc converter in a wide operating range of the drive. Experimental results obtained on the developed laboratory prototype of the proposed harmonic mitigator are used to validate the model and design of the ac-dc converter.