• The Korean Journal of Applied Statistics
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• v.23 no.6
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• pp.1103-1113
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• 2010

An extensively used approach for family based association test(FBAT) is compared with the sib transmission/disequilibrium test(S-TDT), and in particular the adjusted S-TDT, in which the covariance among related siblings is taken into consideration, can provide a more sensitive test statistic for association. A simulation study comparing the three test statistics demonstrates that the type I error rates of all three tests are larger than the prespecified significance level and the power of the FBAT is lower than those of the other two tests. More detailed studies are required in order to assess the influence of the assumed conditions in FBAT on the efficiency of the test.

• The Korean Journal of Applied Statistics
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• v.23 no.3
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• pp.457-469
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• 2010

The government real estate policy has repeatedly relaxed and reinforced controls under the mutually contradictory targets. Switching over the supporting policy after the IMF crisis to the regulating policy from 2003, the government housing policy began to generate ill effects due to various regulations. This stud carefully investigates and statistically tests the transmissions of variations in the housing prices between the metropolitan areas in the early stage of the preceding administration, under the effect of the supporting scheme, and those in the late stage, under the effect of the restricting scheme. The distinctive feature between the two periods is found to be much simplified interrelationships of the price variations in the latter period. Consolidated leading role of capital sphere, by concentrated economic strength, suggest the obvious imbalance between variations in the metropolis housing prices.

• The Korean Journal of Financial Management
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• v.11 no.2
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• pp.41-64
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• 1994

1988년 초부터 1994년 5월 1일까지 합병된 135개 등록 및 상장기업중 충분한 자료가 확보되어 있는 83개 기업을 표본으로 하여 합병기업의 재무적 특성과 이를 바탕으로 하여 합병대상기업에 대한 예측력을 검증하였다. 피합병기업의 재무적 특성 중 통계적인 유의성이 뒷받침된 것들은 다음과 같았다. 피합병기업은 상대적으로 비효율적으로 운영되고 있었으며, 레버리지가 높고, 장기 채무지급능력이 낮았으며, 기업의 성장성과 자원간의 불균형이 있는 것으로 나타났다. 예측력검증은 선형판별식을 이용하여 예측에 이용될 재무비율을 선정하였으며, 3개의 모형에 적용한 결과 최저 42.4%에서 최고 62.4%까지의 분류정확도를 얻을 수 있었다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.9
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• pp.828-833
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• 2011

A reaction wheel assembly(RWA) is the largest disturbance source that can induce high frequency micro-vibration on an optical payload of satellites. To ensure a tight pointing-stability budget of satellites, the RWA disturbance effect on spacecraft should be accurately analyzed and evaluated for whole design phases. For this purpose, the micro-vibration disturbance of RWA should be precisely measured. In the present study, two measurement methods on RWA micro-vibration disturbances are compared and investigated. One is a free run-down speed test and the other is a constant speed test. The micro-vibration data measured by the two methods are analyzed in terms of spectrum characteristics, static and dynamic imbalance values, and root sum square(RSS) values. The analysis results show that both methods can measure very similar results in time and frequency domains and that the free run-down speed method is more adequate in respects to wheel friction modeling, noise rejection of imbalance and RSS peak evaluation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.8 no.1
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• pp.21-24
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• 1979

A study was made to investigate the effect of L-lysine fortification on the quality of rice protein by albino rat-feeding trials. Five subjects fed diets providing 1) rice protein only, 2) rice protein+0.25% L-lysin HCI, 3) rice protein+0.5% L-lysin HCI, 4) rice protein+0.75% L-lysin HCI and 5) rice protein+1.0% L-lysin HCI for 28 days respectively. Protein efficiency ratio(PER) indicated that 0.25% lysine fortified diet had highest value. Lower PER values were shown in the higher fortified diets(0.5% through 1.0% L-lysine) comparing to 0.25% fortified diet. However, there was no adverse effect on the protein quality by the given fortificaton level($0{\sim}1.0%$ L-lysin HCI addition).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2785-2792
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• 2013

An elevator is driven by the friction between the pulley and wire rope. A balancing counter weight is connected to the elevator car with a wire rope. This structure is essential to drive elevators while it always has weight unbalance problems on each side. The overbalance-ratio of elevators may be an important factor for safety and structural efficiency; however, it is not yet clearly defined in the Requirements of Korea Elevator Inspection. This paper describes these "weight unbalance ratio" for control of elevators to reduce the number of accidents. It includes the analysis of current elevator maintenance situations and also proposes some fundamental improvement schemes for safety.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.513-518
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• 2007

Loss of multiple teeth by multiple dental caries, traumatic influence or hereditable disease can cause many problem in children. Using removable appliance can be used for treatment of this problem. But conventional removable appliance has limits of retention by wire-clasp, non esthetic appearance, difficulty in pronunciation by its volume. Flexible denture using $Valplast^{(R)}$ system could be a excellent partial denture for restorarion in child because of various advantage such as retention from soft tissue, natural esthetic aspect, biocompatibility, durability to compare with conventional acrylic appliance. The present case report describe properties and consideration of flexible denture using Valplast $system^{(R)}$ in comparison with conventional acrylic appliance and report successful restoration of child using Valplast $system^{(R)}$.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.4 no.1
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• pp.98-105
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• 1993

Objective ' The purpose of this study was to investigate the behavioral characteristics of children with allergic disease Method : In a population of 80 children who were registered at a pediatric allergic clinic in Kangnam St Mary's hospital, parents completed a standardized child behavior checklist (CBCL) to evaluate their children Clinical factors associated with allergy were examined in relation to the rated scores of CBCL Results : Allergic children were rated significantly more aggressive and delinquent, and less withdrawned on the CBCL rating when compared to the age- and sex-matched normal control children. Within the allergic population, children who had family history of allergic disease had higher scores of CBCL in hyperactivity and aggressive behavior than the children without family history. Conclusion : The results were discussed with the respect to familial traits of allergy and temperament as risk factors for the emergence of behavior problems in childhood allergy

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1991.04a
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• pp.47-52
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• 1991

주거환경을 침해하는 소음의 주된 요인은 가전제품으로서, 대부분의 가전제 품은 전기모터에 의해 구동된다. 가전제품을 작동시키는 전기모터는 가전제 품에 기진력을 주는 한편 공기중으로 소음을 방사함으로서 조용한 주거환경 을 해치게 된다. 따라서 조용하고 쾌적한 주거환경 확보를 위해서는 가전제 품용 구동모터의 소음을 효과적으로 차단 또는 감소해야 한다. 모터의 소음 원은 그 모터의 종류와 형태에 따라 약간씩은 다를 수 있으나 일반적으로 크게 기계적 소음, 공기 역학적 소음, 전자기 소음, 열/전기 화학적 소음 등 으로 분류된다. 이들 중 모터의 소음에 큰 영향을 주는 것은 기계적 소음, 공기 역학적 소음, 전자기 소음이며 열/전기 화학적 소음은 매우 작은 편이 다. 또한 공기 역학적 소음은 모터에 팬이 부착될 경우에만 큰 문제가 될 뿐 이며, 팬이 부착되지 않을 경우에는 기계적 소음과 전자기 소음이 주된 소음 원이 된다. 기계적 소음과 전자기 소음은 어느 것이 주된 소음원인지는 일반 적으로 잘 알 수 없기 때문에, 개별적인 연구와 실험을 통하여 파악해야 한 다. 기계적 소음은 주로 회전자의 불균형 회전에 의한 진동 및 그로 인한 외 부 프레임의 진동으로 대별되며, 전자기 소음은 주로 공급(Air-Gap)에서의 투과파(permeance wave)와 기자력(magneto-motive force)에 의한 반지름 방향의 힘에 의해 주로 발생된다. 본 연구에서는 기계적 소음과 전자기 소음 중 모터 소음에 영향이 큰 소음원을 판별해 내고 모델 실험을 통하여 감소 방안을 검토하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.7
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• pp.640-646
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• 2007

Actuator-induced disturbance is one of the crucial factors of spacecraft attitude pointing and stability in fine attitude control problems. The control moment gyros (CMGs) are known as very attractive actuators from the point of high power and low weight. In order to develop a CMG as an actuator for fine controls, CMG-induced disturbances should be analyzed. Therefore, this paper aims to develop an analytic model and predict the effect of disturbances of CMGs by assuming static and dynamic imbalances. The proposed model is induced by the Lagrangian method on the basis of the small signal assumption.