• 경영과학
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• 제12권1호
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• pp.111-124
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• 1995

With the increasing interest of reducing process variation, statistical process control has served the pivotal tool in most industrial quality programs. In this study, system analyses have been performed associated with a cost incorporated version of a process control, a quadratic loss-based X over bar control chart model. Specifically, two issues, the capital/research investments for improvement of a system and the precision of a parameter estimation, have been addressed and discussed. Through the analysis of experimental results, we show that process variability is seen to be one of the most important sources of loss and quality improvement efforts should be directed to reduce this variability. We further derive the results that, even if the optimal designs may be sensitive, the model appears to be robust with regard to misspecification of parameters. The approach and discussion taken in this study provide a meaningful guide for proper process control. We conclude this study with providing general comments.

• 중소기업융합학회논문지
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• 제2권1호
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• pp.1-9
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• 2012

본 논문은 기존 고객 클레임 응대를 간소화, 향상시키기 위하여 QR코드를 활용하는 방법을 제안한다. 기존 고객 클레임 프로세스를 설명하고 1차원 바코드, RFID 및 QR코드를 비교하여 QR코드가 가지는 장점을 활용하여 클레임 업무에 적용한다. 제안한 클레임처리 프로세스를 실제 M사에 적용하여 그 효율성을 검증하였고 그 효율성을 검증하기 위하여 설문을 통하여 효과를 평가하였다.

• Journal of Welding and Joining
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• 제14권2호
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• pp.57-64
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• 1996

In this paper, authors are trying to find optimum spot weldig conditions to minimize indentation of the plate surface which is crucial to quality of stainless rolling stocks. At first, to derive a simple equation to estimate the depth of indentation, a simplified one-dimensional bar model is proposed and validity of the model is confirmed by experiments. And also, to find proper welding conditions giving satisfied tensile strength of the welded joint, a simple formula is derived referring to the standard spot welding conditions by AWS. Optimization problem is formulated to find welding conditions such as welding current, time and applied force which give minimum indentation and proper tensile strength of joint, and solutions are found out. According to the results, the depth of indentation can be expressed by applied electrode froces and it can be shown that an optimum applied force exists.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.713-718
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• 2003

Decubitus ulcer is a pressure-induced ulceration of the skin occurring in persons confined to bed for long periods of time. In order to prevent decubitus ulcer, the medical bed mechanism to minimize pressure, friction, and shear forces acting between bed and patient had been developed. Air mattress also can be effective for reducing pressure over bony prominence. In this study, motion analysis was performed to examine whether this bed mechanism functioned properly in case of using air mattress, which was much thicker than common hospital mattress. We found that the patient on the air mattress above the medical bed for preventing decubitus ulcer slipped upward and downward excessively as the general motored-bed. New bed mechanisms were synthesized kinematically using simple 4-bar and 6-bar linkages so as to reduce sliding between the bed and the patient on the air mattress for preventing decubitus ulcer.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.47-54
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• 2003

The rotating of rotatory unit with its structural unbalance mass and laundry is making the main vibration problem in a vertical axis washing machine. For reducing vibration problem total washing system hung on the case by its suspension system which is constitute of spring, damper and suspension bar and hydraulic balancer is attached at the upper rim of spin basket. In this paper, we make the dynamic model of washing system of its rigid body motions by 6 degree of freedoms. Hydraulic balancer is modeled by one degree of freedom like auto ball balancer. Elastic motions of washing system have found by method of analytic, experimental and FEM. And we consider first bending mode of each suspension bar and first circumferential mode of assy tub. So, the total washing system is modeled by 12 degree of freedoms. Equations of motion for total washing system have derived, and we perform the dynamic simulation tests.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.21-24
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• 2004

Structural performance of the seismic devices made by steel bar and high performance fiber reinforced cement composites(HPFRCCs) was experimentally observed. These dampers will be applied for reducing damage as well as seismic response. The advantages of the HPFRCCs damper is selective structural performance, strength, stiffness, and ductility by changing configuration, bar arrangements and type of materials used. The experimental results indicate that elemental ductility is much increased with decreasing damage when the HPFRCCs are applied to the damper. It means cementitious damper for structural control is available which has much merit in performance and cost.

• 한국인쇄학회지
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• 제26권2호
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• pp.15-30
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• 2008

Studies were carried out the phenomenal observation on the effect of corona treated hotmelt laminating film in process of manufacture by 2 kinds of experiments. These are as follow: 1) In order to verify the treatment reducing value of dynes and dynes durability with the lapse of time, it was checked dynes of a pair of 4 bar discharge electrode with 9 one for 144 hr., and it show results that 9 bar discharge electrode has higher initial dynes as well as keep up 48 dynes durability long than 4 one. 2) Drawn an inference from 3 actions -Chemical-Physical-Mechanical, on laminating film in terms of SEM's observation that are the adhesive status in boundary of corona treated base film, extrusion coating hotmelt layer, and configuration of hotmelt surface after corona treated. In tandem system, EVA layers adhesion keep its stability without corona discharge treatment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.27-29
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• 2001

In this paper, we study in magnetizing the NdFeB magnet which is inserted in a squirrel cage rotor. The inserted NdFeB magnet need much more magnetizing flux than that of ferrite magnet. Also the eddy current flowing in rotor bar disturbs the magnetizer in magnetizing the NdFeB magnet. The existing magnetizing yoke is designed by increasing the coil turn. But we recognize that only by increasing the coil turn it is impossible to make NdFeB magnet magnetized fully. Hence, in this paper we propose the method of increasing magnetizing flux by reducing the rotor bar area.

• 한국기계가공학회지
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• 제18권5호
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• pp.103-109
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• 2019

The pressure reducing valve for water is controlled by the load of the compression spring and the force of the fluid acting on the diaphragm of the stem. Repeated upward and downward reciprocation of the pressure-reducing valve stem damages the diaphragm, resulting in leakage. In this study, we designed a stem without a diaphragm and adjusted the stiffness of the compressing spring. In order to select the spring stiffness, springs offering a stiffness of -20%, -10%, 0%, and 10% with respect to the stiffness of the compression spring attached to the existing pressure reducing valve stiffness. A prototype for the pressure reducing valve was fabricated and the pressure change was evaluated for the target static pressure (6 bar) by testing the pressure characteristics after mounting the modified stem and each compression spring. Evaluation of the pressure characteristics was carried out using ASSE 1003 and KS B 6153. In addition, the flow rates were compared by internal flow analysis of the conventional pressure reducing valve and the pressure reducing valve using the modified stems, and the flow analysis was performed using Solidworks flow simulation 2018. The spring stiffness was constantly discharged at the target static pressure of 3.793 kgf/mm, and the flow rate was increased by about 15% compared with the conventional pressure reducing valve.

• 생물환경조절학회지
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• 제15권4호
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• pp.377-384
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• 2006

오이묘가 저온피해를 입기 전, 후 토양수분조건과 몇 가지의 화학물질처리가 오이묘의 냉해 경감에 미치는 영향을 연구한 결과 토양수분 -0.3bar 적습상태에서 07:00시에 $2^{\circ}C$로 저온처리를 했을 때, 생존율은 28.3%이었으나 -5.5bar에서는 83.3%로 높아져 토양수분이 건조하면 저온피해가 감소되었다. 그러나 18:00시에 저온처리하면 -0.3bar에서도 생존율은 87% 이상이었다. 토양수분이 건조하면 엽신의 ABA함량은 크게 증가되었다. 저온처리 전, 후 ABA의 토양 및 엽면처리는 오이묘의 생존율을 유의하게 증가시켰고 세포의 전해질 누출량도 현저하게 감소시켰으며, 수량의 감소를 경감시켰다. 또한 ABA 처리는 저온처리 후보다는 저온처리 전에, 엽면처리보다는 토양에 처리하는 것이 보다 효과적이었다. ABA($10^{-5}M$)와 더불어 요소(0.2%)와 $KH_2PO_4$의 엽면살포는 오이의 생장과 수량에 미치는 저온피해를 경감시키는데 효과적이었다.