• 전기학회논문지
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• 제67권1호
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• pp.29-37
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• 2018

Inrush current and fault current in a transformer need to be distinguished from one another. In order to do this, KEPCO uses a 2nd harmonic restraint/block method. We use two setting values for 2nd harmonic restraint; 15% and 10%. We also apply per-phase blocking method among various harmonic restraint methods. If the transformer is located at the radial system, we adjust 10% in the 2nd harmonic restraint, but this method is not enough to prevent mal-operations of the current differential relay and let us spend more time to change setting value again as the power system changes. In this paper, a more reasonable setting value for a 2nd harmonic blocking scheme in KEPCO is proposed. To present a proposed method, the fault data of the current differential relays which have occurred since 2009 are analyzed. To evaluate the performance of the proposed method, the results of the RTDS test for the current differential relay of the transformer by KEPCO are analyzed.

• Journal of Acupuncture Research
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• 제20권3호
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• pp.177-193
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• 2003

Objective : The present studies investigated the effects of 120Hz high frequency electroacupunctue(EA) on the stress-induced stomach dysfunction in relation to its effect on the level of stress hormone and gastric mucosal damages. The gastric mucosal injury was induced by cold-restraint stress and two acupoints corresponding to Zusanli and Sanyinjiao in man were used. Methods: Cold-restraint stress produced typical gastric lesions in all rats of the stressed groups, but he number of ulcers as well as the mean ulcer diameter were reduced by 120 Hz EA pre-treatment. The cold-restraint stress also induced an increase in catecholamine response involving epinephrine, norepinephrine and dopamine, but an slight decline were observed in EA pre-treated rats compared with cold-restrained rats. Results: The degranulation value of gastric mast cell was significantly higher in cold-restrained rats than in control ones. However, with the significant reduction of degranulation values of gastric mast cells in EA pre-treated rats compared with cold-restrained ones, $PGE_2$ content in the gastric mucosa of EA pre-treated rats was also different from that observed in cold-restrained rats. Cold-restraint stress induced an elevated mRNA expression of pro-inflammatory gene such as cyclooxygenases-2 and tumor necrosis factor(TNF)-${\alpha}$, but these expression were down-regulated in EA pre-treated rats. Immunohistochemecal analysis showed that while the inhibitory-${\kappa}B{\alpha}$ an TNF-${\alpha}$ immunoreaction in the surface epithelium of the stomach tended to increase, both reactions in the EA pre-treated rats showed similar pattern as observed in controls. Conclusions : These results suggest that 120 Hz EA may act as a therapeutical means for gastric mucosal damages through a activation of pituitary adrenal system. it could be concluded that 120 hz high frequency electroacupuncture affords a good protective potential against stress-induce gastrointestinal dysfunction.

• Nuclear Engineering and Technology
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• 제33권3호
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• pp.298-306
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• 2001

As fuel burnup proceeds, thermal gradients, differential swelling, and inter-assembly loading may induce assembly duct bowing. Since duct bowing affects the reactivity, such as long or short term power-reactivity-decrement variations, handling problem, caused by top end deflection of the bowed assembly duct, and the integrity of the assembly duct itself. Assembly duct bowing were first observed at EBR-ll in 1965, and then several designs of assembly ducts and core restraint system were used to accommodate this problem. In this study, NUBOW-2D KMOD was used to analyze the bowing behavior of the assembly duct under the KALIMER(Korea Advanced Liquid MEtal Reactor) core restraint system conditions. The mechanical behavior of assembly ducts related to several design parameters are evaluated. ACLP(Above Core Load Pad) positions, the gap distance between the ducts, and the gap distance between the duct and restraint ring were selected as the sensitivity parameter for the evaluation of duct deflection.

• 대한기계학회논문집A
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• 제29권11호
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• pp.1518-1526
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• 2005

With increasing need of transportation services for people with disabilities and the aged, wheelchairs are used as their assistive devices to participate in daily and recreational activities and as seats of motor vehicle. However, as wheelchairs are primarily designed fer mobility assistive devices, not for vehicle seats, wheelchair users may experience serious injury when they meet car crashes. To date, neither engineering guidance for a wheelchair mounting system on the vehicle floor nor safety assessment analysis by a car crash has been studied for the domestic users. In this paper, in accordance with the ANSVRESNA WC-19, a fixed vehicle mounted wheelchair occupant restraint system (FWORS), wheelchair integrated restraint system (WIRS), and wheelchair integrated x-bend restraint system (WIXRS) subjected to frontal impact (20 g, 48 U) were analyzed using compute. simulations for domestic users. We present surrogate wheelchair occupant safety by head injury criteria (HIC), motion criteria (MC), and combined injury criteria (CIC).

• International Journal of Concrete Structures and Materials
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• 제6권4호
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• pp.221-230
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• 2012

Cracking of repair material due to restraint of shrinkage could hinder the intended extension of serviceability of repaired concrete structure. The availability of model to predict shrinkage stress under restraint condition will be useful to assess whether repair material with particular deformation properties is resistance to cracking or not. The accuracy in the prediction will depend upon reliability of the model, input parameters, testing methods used to characterize the input parameters, etc. This paper reviews a variety of models to predict shrinkage stress in patch repair system. Effect of creep and composite action to release shrinkage stress in the patch repair system are quantified and discussed. Accuracy of the models is examined by comparing predicted and measured shrinkage stress. Simplified model to estimate shrinkage stress is proposed which requires only shrinkage property of repair material as an input parameter.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.826-827
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• 2013

• 한국항공운항학회지
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• 제26권3호
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• pp.93-104
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• 2018

It is mandatory to use car seats for infants and children in the private vehicles in accordance with the traffic law of Korea. Recently, legislation has also been proposed to expand the use car seats to express and intercity buses. This reflects a growing consensus that mandatory infant and child car seats, both for private and commercial vehicles, are essential. However, Korean laws concerning infants and children on board aircraft allow parents or guardians to hold children under two years of age on their laps without any restraint devices. It is not possible for a parent to physically restrain an infant or child, especially during a sudden acceleration or deceleration, unanticipated or severe turbulence, or impact. The use of CRS provides an equivalent level of safety to infants and children as that afforded to adult passengers wearing seat belts. But there is no regulation even about Child Restraint Systems on board aircraft in Korea. To enhance their safety, infants and children should be restrained in an approved child restraint system that is appropriate to their weight and height. It is necessary to examine whether infants and children in flight can achieve the same level of safety as an adult.

• 한국유통학회지:유통연구
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• 제15권5호
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• pp.217-235
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• 2010

프랜차이즈 산업에서 지역제한(territorial restraint, 가맹점 상권보호조건)은 가맹본부가 가맹점에게 일정한 지역 내 영업권리을 보장하여 가맹점주들의 안정적인 영업활동을 보장해 주는 제도이다. 이러한 지역제한의 의미는 가맹점주의 초기 투자에 대한 지역 내 독점이윤을 보장하고 차후에 가맹본부는 기존 가맹점의 상권을 보호하여 동일 브랜드를 출점시키지 않겠다는 약속을 담고 있다. 지역제한은 이와 같이 가맹본부의 사후 기회주의(postcontractual opportunism)를 사전에 방지할 수 있는 제도이다. 본 연구는 실제 외식프랜차이즈 기업들을 대상으로 지역제한의 여부에 따른 브랜드 수와 계약해지정도를 살펴보고자 한다. 우선 브랜드 수를 분석하는 목적은 브랜드 수에 따른 프랜차이즈본사의 기회주의를 살펴볼 수 있기 때문이다. 지역제한이 계약서에 반영된 상태에서는 가맹본사가 동일한 이름의 브랜드 입점이 불가능하기 때문에 새로운 브랜드를 만들고자 할 것이다. 즉 계약서에서 언급한 동일한 브랜드 조건을 피해가면서 해당 상권에 또 다른 가맹점을 출점시키려고 할 것이다. 따라서 가맹본사의 기회주의가 존재한다면 계약서의 지역제한 명기에 따라서 보유하는 브랜드수가 달라질 것이다. 또한 지역제한이 계약서에 명기된 경우, 기존 가맹점들에 대한 계약해지 사유 발생 시 즉각적인 실행에 대한 동기가 높아질 것이다. 가맹본사는 새로운 점포를 개설할 때마다 추가비용(인테리어비용, 개설비, 초기 집기 비용 등)을 매출로 인식하기 때문에 지역제한 때문에 출점에 제한을 받아오던 본사입장에서 가맹점의 계약해지 상황에 대해서 적극적으로 실행할 수밖에 없다. 따라서 지역제한이 존재할 경우, 기존 가맹점에 대한 계약해지 가능성이 그 만큼 높아지는 것이다. 분석 결과, 브랜드 숫자와 계약해지 정도는 지역제한에 따라서 차이가 있어 가맹본사는 지역제한이 있는 경우, 더 적극적으로 새로운 브랜드를 시장에 출시하려고 하며 계약해지 사유에 대해서도 적극적으로 반응하는 것을 알 수 있었다.

• 대한의용생체공학회:의공학회지
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• 제37권3호
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• pp.105-111
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• 2016

Introduction: Surgical robot is the alternative instrument that substitutes the difficult and precise surgical operation; should have intuitiveness operationally to transfer natural motions. There are limitations of hand motion derived from contacting mechanical handle in the surgical robot master interface such as mechanical singularity, isotropy, coupling problems. In this paper, we will confirm and verify the feasibility of intuitive Non-restraint master interface which tracking the hand motion using infra-red camera and only 3 reflective markers without the hardware handle for the surgical robot master interface. Materials & methods: We configured S/W and H/W system; arranged 6 infra-red cameras and attached 3 reflective markers on hands for measuring 3 dimensional coordinate then we find the 7 motions of grasp, yaw, pitch, roll, px, py, pz. And we connected Virtual-Master to the slave surgical robot(Laparobot) and observed the feasibility. To verify the result of motion, we compare the result of Non-restraint master and that of clinometer (and protractor) through measuring 0~180 degree, 10degree interval, 1000 samples and recorded standard deviation stands for error rate of the value. Results: We confirmed that the average angle values of Non-restraint master interface is accurately corresponds to the result of clinometer (and protractor) and have low error rates during motion. Investigation & Conclusion: In this paper, we confirmed the feasibility and accuracy of 3D Non-restraint master interface that can offer the intuitive motion of non-contact hardware handle. As a result, we can expect the high intuitiveness, dexterousness of surgical robot.

• International Journal of Automotive Technology
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• 제8권2호
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• pp.185-191
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• 2007

The new FMVSS 208, 213, 225 regulations include automatic suppression of airbags to prevent low-risk airbag deployment and the use of child seats with a rigid-bar anchor system. The regulations mean that children must sit in the rear seat, but do not include other specific safety measures for their protection. In the rear, restraint equipment consists of three-point shoulder/lap belts for the outside seats and a static two-point lap belt in the middle, with no additional devices such as pretensioners or load limiters; this is far from optimal for children. This study investigated injury rates using a 3-year-old-child dummy. ECE R44 sled tests used a booster, a speed of 48 km/h, and a 26- to 32-g rectangular deceleration pulse. While seated on a booster, the dummies were restrained by an adult shoulder/lap three-point belt. HIC_15 msec, Chest G and Nij were somewhat lower with an emergency locking retractor (ELR)+pretensioner+load limiter than with only an ELR or with ELR+pretensioner. However, the current seat-belt system results in injury rates that exceed the limit for OOP performance under the new FMVSS 208 regulations.