• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권4호
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• pp.237-246
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• 2004

The advantages of the Magnetic Fluid Linear Pump(MFLP) is that this device could Pump the non-conductive. non-magnetic liquid such as Insulin or blood because of the segregation structure of the magnetic fluid and pumping liquid. In this device. the sequential currents are needed to Produce pumping forces so that Pumping Forces and Pumping speed mainly depend on the current Patterns. The excessive forces at Pumping moment could cause the medical shock, and weak forces at intermediate moment could cause the back flow or the pumping liquid. So the ripples of the pumping forces need to be reduced for the medical application. In this research, the driving characteristics in the MFLP by operating current is analysed. The change of magnetic fluid surface according to the driving currents could be obtained be magneto-hydrodynamic analysis so that Pumping fortes could be computed by integration of the surface moving to the pumping direction at each moment. The actual MFLP with 13mm diameter was made and tested for experiments. The effects of driving current and frequency on the pumping forces and pumping speed were analyzed and compared with experimental measurements.

• 한국화재소방학회논문지
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• 제30권4호
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• pp.82-87
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• 2016

초고층 건물의 환기계획에서 설비의 효율적인 운영을 위해 환기설비는 제연설비 겸용으로 사용되고 있다. 본 연구에서는 지하 4층 지상 59층의 초고층 건물을 분석모델로 선정하고 수치해석을 통해 연기이동력에 의한 층별 압력분포를 검토하였으며, 분석모델 건물에서의 연기이동력이 환기 및 제연에 미치는 영향을 규명하였다. 또한 이들 결과를 바탕으로 분석모델 건물의 환기계획에서 주방용 환기댐퍼를 환기-제연 겸용으로 설계할 때 연기이동의 복합력과 요구되는 댐퍼의 개폐력과의 관계를 운동해석 시뮬레이션을 통해 결정하였고, 그 결과로부터 적합한 댐퍼의 구동장치를 선정하였다.

• Journal of Mechanical Science and Technology
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• 제14권1호
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• pp.30-38
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• 2000

This paper presents a framework how to estimate crack driving forces in terms of crack-tip opening displacement and J-integral for mismatched dissimilar joints with interface cracks. The mismatch in elastic, thermal, and plastic hardening properties is not considered, but the mismatch in plastic yield strengths is emphasized here. The main outcome of the present work is that the existing methods to estimate crack driving forces for homogeneous materials can be used with slight modification. Such modification includes (i) mismatch- corrected limit load solutions, and (ii) evaluating the contribution of each material in dissimilar joints to the total crack driving force, which depends on the strength mismatch of the dissimilar joints.

• 대한기계학회논문집A
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• 제21권6호
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• pp.871-883
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• 1997

Kinetodynamics of a cam driving slider mechanism consists of kinematic analysis and force analysis. The kinematic analysis is to determine the kinematic characteristics of a cam driving mechanism and a slider mechanism. The force analysis is to determine the joint forces of links, the contact forces of the cam and follower, and the driving torque of a main shaft. This paper proposes a close loop method and a tangent substitution method to formulate the relationships of kinematic chains and to calculate the displacement, velocity and acceleration of the cam driving slider mechanism. Also, and instant velocity center method is proposed to determine the cam shape from the geometric relationships of the cam and the roller follower. For dynamic analysis, the contact force and the driving torque of the cam driving slider mechanism are calculated from the required sliding forces, sliding motion and weight of the slider.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.184-190
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• 2004

Over the last few years, there has been a growing interest in quantitative representation of the weld pools in order to relate the processing conditions to the driving forces of the weldment produced and to use this information for the optimization of the welding process. A theoretical model offers a powerful alternative to check the physical concepts of the welding process and the effects of driving forces. To solve this problem, a 2-D thermo-fluid model were eve loped for determining temperature and velocity distribution for the GMA welding process.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.398-401
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• 2003

세계시장의 환경 변화에 대응하며 선진 기술력을 지닌 국가가 국제경쟁에 있어서 경쟁력을 확보하게 될 것이다. 최근 정부는 이러한 변화에 대한 대응과 국내 산업들의 국제 경쟁력 증가 및 국내 경제 활성화를 위해 "차세대 성장동력 산업 추진계획"을 제시하였으나 건설산업은 이에 대한 논의에서 제외되어 일음을 발견한 수 일다. 본 연구는 "건설산업이 미래지향적인 성장엔진과는 무관한 산업인가?"라는 문제의식과 "건설산업의 성장엔진을 발굴함에 있어서 어떤 요건이 고려되어야 하는가?"라는 연구질문(research question)을 바탕으로 착수되었다. 본 연구의 목적은 최근 6T 산업분야에서 제시되고 입는 성장엔진에 대한 조사 분석을 통해 이들 성장엔진이 지니는 공통적인 특성을 도출하고 이러한 특성을 바탕으로 건설산업의 성장엔진 발굴을 위한 방향성을 제시하는데 있다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제26회 추계학술대회
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• pp.76-85
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• 1997

Recently, bent-axis-type axial piston pumps drived by rod being in extensively used in the world, because of simple design, lightweight, effective cost. So, to guarantee the quality of bent-axis-type axial piston pumps drived by rods, it is necessary to know chracteristics of the forces applied to rods and the driving mechanism of rods. But, as they perform both reciprocating and spinning motions, it is difficult to understand driving mechanism. In this paper, I explained the theoretical driving mechanisms of cylinder block drived by rods through geometric method and the characteristics of the forces applied to them.

• Journal of Mechanical Science and Technology
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• 제17권2호
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• pp.181-186
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• 2003

In order to assure the quality of the bent axis design axial piston pumps driven by tapered pistons, it is necessary to know the characteristics of force applied to tapered pistons and the mechanism for driving the tapered pistons. Since they are able to perform both reciprocating and spinning motions in cylinder block, it is difficult to understand the driving mechanismand-tomeasure the forces applied to tapered pistons experimentally In the present study, the theoretical mechanism for driving the tapered pistons is studied by use of the geometric method. The driving area of the tapered pistons is measured by measuring the strain of a cylinder forced against a tapered piston using an electric strain gauge and a slip ring. The forces applied to tapered pistons is also investigated with the change of discharge pressure and the rotational speed. As a results of this investigation, it is concluded that the cylinder block is driven by one tapered piston in a limited area and the driving area is changed due to space angle of the tapered pistons and the swivel angle of the cylinder block. It is also observed that the force applied to tapered pistons increases as the discharge pressure and the rotational speed increase.

• 열처리공학회지
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• 제9권4호
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• pp.243-251
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• 1996

Dilatometric experiment and thermodynamic calculation have been performed to determine $M_s$, $A_s$ and driving forces for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation of Fe-Mn alloys. The transformation temperatures($M_s$, $A_s$, $T_o) were decreased with increasing manganese content and were newly formulated as a function of manganese content. Driving force for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation was increased from -75J/mole to -105J/mole with increasing manganese content from 15wt.% to 25wt.%. Transformation temperature hysteresis($A_s-M_s$) was also increased from 50K to 80K with increasing mangenese content from 15wt.% to 25wt.%. The small driving force(-75J/mole~-105J/mole) and small ${\Delta}T$(50K~80K) for ${\gamma}{\rightarrow}{\varepsilon}$ martensitic transformation indicated that Fe-Mn alloys behave like thermoelastic martensitic alloys : We would like to call them semi-thermoelastic martensitic alloys.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.1-10
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• 1996

The objective of this paper is to develop a motion base for the vehicle driving simulator. Kinematic analysis are carried out to obtain maximum strokes and velocities of hydraulic actuators. Hydraulic control forces of the actuators are estimated by inverse dynamic analysis. Finally, an optimal design is performed to find attachment points of the actuators so that control forces are minimized. A control logic for the motion base is developed to make the motion base follow the given reference signals. The control logic is implemented on a digital signal processor(DSP) board.