• 한국지반공학회논문집
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• 제23권11호
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• pp.15-26
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• 2007

L. A. 마모율 시험은 건설용 골재의 강도를 확인하기 위한 방법으로 주로 석산의 모암을 대상으로 시행하여 왔다. 본 연구는 경상분지 퇴적암이 집중 분포되어 있는 25 지점에서 지질학적 특성을 대표할 수 있는 324 브록의 시료를 채취하여 L. A. 마모율시험으로 각종 공학지수(일축 압축강도, 압열 인장강도, 탄성계수, 점하중 강도지수, Schmidt 해머 반발지수)를 추정하기 위한 실험을 시행하여 회귀 분석법으로 서로간의 상관성을 확인한 결과, 상호간 좋은 상관관계가 있음을 확인하였다. 이 방법이 다른 공학지수를 추정함에 손색이 없으므로 이후에도 많은 활용이 있기를 기대한다.

• Journal of KIEE
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• 제11권1호
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• pp.51-54
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• 2001

In this paper, a MW-Mvar investment technique focused on minimizing the system loss is presented. An optimization technique, in which the system loss is defined as the objective function and the power flow equations as the constraints, is introduced to obtain the Lagrangian multipliers λP and λQ. The Lagrangian multipliers imply the variation of the system loss with respect to incremental bus power and are used as MW-Mvar investment indices for minimizing the system loss. ΔP MW and ΔQ Mvar are invested, step by step, by the priority of λP and λQ index given for each bus. Derivation of the index uses the information from normal power flow calculation.

• Journal of Nutrition and Health
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• 제42권5호
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• pp.453-463
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• 2009

This study was to evaluate the effectiveness of the weight control program for female college students. The program was composed of diet and behavioral modifications for 8 weeks. A total of 78 participants enrolled the weight control program. Upon completion of the program, 53 participants experienced weight loss and 25 did not. The intakes of carbohydrate and fat were significantly decreased in both groups. However, the total diet quality index-international (DQII) scores as well as individual scores such as variety scores for protein source and adequacy scores for vegetable, fiber, calcium and vitamin C and moderation scores for empty calorie food were increased significantly in weight loss group only. In the weight loss group, weight, BMI, body fat, percent body fat and waist-hip ratio were decreased significantly. In addition, compared to the weight gain group, the weight loss group had higher changes in weight (weight loss group: -2.6% vs weight gain group: 1.5%, p < 0.001), body fat (-6.0% vs 0.0%, p < 0.001), percent body fat (-3.1% vs -0.3%, p < 0.001), waist-hip ratio (-1.0% vs 0.5%, p < 0.001) and BMI (-2.6% vs 1.3%, p < 0.01). There was no difference in blood profiles between the two groups. The changes in DQI-I scores were significantly correlated with the changes in body weight (r = -0.239, p < 0.05) and BMI (r = -0.224, p < 0.05), indicating that effective nutrition education could help improve diet quality leading to successful weight management among female college students.

• 한국산학기술학회논문지
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• 제14권11호
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• pp.5956-5963
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• 2013

친환경 하천사업의 활성화로 식생매트의 사용은 증가하고 있으나 수리적 안정성에 대한 평가기법은 제시되지 않은 실정이다. 본 연구는 호안용 식생매트 제품의 객관적인 수리안정성 시험 기법 개발을 위해 수행하였다. 이를 위해서 식생매트 2종에 대한 실규모 실험을 수행하여 수리량을 측정하고 분석하여 작용 소류력을 계산하였다. 작용 소류력에 대한 토양손실평가를 위하여 지상라이다에 의한 측량을 수행하고 실험 전후의 하상고 변화를 평가하여 토양손실지수(CSLI)를 산정하였으며, 작용 소류력과 함께 도시하여 허용 소류력을 정량적으로 평가하였다. 하상고에 대한 정밀 측량 결과 분석에 의해서 식생매트가 안정한 경우에는 하상 변동이 국부적으로 제한되나, 불안정으로 판정되는 경우에는 식생매트 하부에서 비교적 큰 규모의 하상 변동이 발생하며 이는 자연 하상의 거동과 유사함을 확인하였다. 이상의 연구를 통해서 ASTM D 6040에 의한 식생매트의 허용 소류력 평가가 파괴 메카니즘 및 토양손실판정 기준에서 유효함을 확인할 수 있었다.

• Smart Structures and Systems
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• 제15권4호
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• pp.1159-1175
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• 2015

In this study, the effect of temperature variation on the wireless impedance monitoring is analyzed for the tendon-anchorage connection of the prestressed concrete girder. Firstly, three impedance features, which are peak frequency, root mean square deviation (RMSD) index, and correlation coefficient (CC) index, are selected to estimate the effects of temperature variation and prestress-loss on impedance signatures. Secondly, wireless impedance tests are performed on the tendon-anchorage connection for which a series of temperature variation and prestress-loss events are simulated. Thirdly, the effect of temperature variation on impedance signatures measured from the tendon-anchorage connection is estimated by the three impedance features. Finally, the effect of prestress-loss on impedance signatures is also estimated by the three impedance features. The relative effects of temperature variation and prestress-loss are comparatively examined.

• 대한물리의학회지
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• 제8권4호
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• pp.573-582
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• 2013

PURPOSE: The purpose of this study was to establish the reliability and validity of the Wheelchair User's Shoulder Pain Index (WUSPI), which was translated into Korean for long-term wheelchair users. This index measured 15 functional activities, including transfer, self-care, wheelchair mobility and general activities. METHODS: To assess test-retest reliability, 23 long-term wheelchair users completed this self-administered index twice within the same day. Reliability was determined by the intraclass correlation coefficient (ICC), and Cronbach's alpha was used to measure internal consistency. To examine concurrent validity, 21 long-term wheelchair users completed the questionnaire, and we examined the correlation between the index score and the shoulder range of motion measurements. RESULT: The results showed that the intraclass correlation for test-retest reliability of the total index score ranging from .88 to .99 was good to excellent. Additionally, Cronbach's alpha was .96. The internal consistency indicated excellent. Concurrent validity showed negative correlations of total index score to range of motion measurements of shoulder flexion (rho=-.58), extension (rho=-.09), abduction (rho=-.59), external rotation (rho=-.07) and internal rotation (rho=-.3), suggesting a relationship of total index score to loss of shoulder range of motion. CONCLUSION: The Korean WUSPI shows not only high reliability and internal consistency, but also concurrent validity with loss of shoulder flexion and abduction.

• 한국광학회지
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• 제10권2호
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• pp.174-177
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• 1999

FHD (Falme Hydrolysis Deposition) 공정으로 실리카 슬렙도파로를 제작하고 전송손실을 측정하였다. 전송손실 측정에는 프리즘커플링으로 빛을 입사시키고 굴절률 정합액으로 출사시키는 장치를 제작 사용하였다. 측정된 전송손실은 1300 nm 및 633 nm에서 각각 0.04 dB/cm 및 0.09 dB/cm의 값을 보였다.

• KIEE International Transactions on Power Engineering
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• 제4A권2호
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• pp.58-68
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• 2004

This paper presents an optimal routing algorithm (ORA) for maximizing voltage stability as well as for minimizing power loss in radial power systems. In the proposed ORA, a novel voltage stability index (VSI) for real-time assessment is newly introduced based on the conventional critical transmission path framework. In addition, the suggested algorithm can automatically detect the critical transmission paths resulting in voltage collapse when additional real or reactive loads are added. To implement an effective ORA, we have developed an improved branch exchange (IBE) method based on a loss calculation index and tie-branch power flow equations, which are suggested for real-time applications. The proposed algorithm has been tested with IEEE test systems as well as a large-scale power system in Korea to demonstrate its effectiveness and efficiency.

• 한국전기전자재료학회논문지
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• 제28권8호
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• pp.513-517
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• 2015

We proposed and demonstrated a simultaneous measurement method to detect the refractive index and temperature of a medium using a side-polished fiber involving FBG (fiber Bragg grating). The temperature of a medium was obtained by using the Bragg wavelength shift of FBG, while the refractive index of medium were calculated by using the transmission loss. The Bragg wavelength is independent on the refractive index of the covering medium placed on surface of side-polished fiber, while the transmission loss at off-Bragg wavelength highly depends on the environmental temperature because of thermo-optic effect of the medium.

• 한국염색가공학회지
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• 제16권2호
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• pp.47-51
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• 2004

A differential refractive index detector was used for monitoring glucose contents in textile processing solutions. The sensitivity of the device was high enough to measure 0.05％ aqueous glucose solution that could not be measured by normal refractive index measurement. The device was set to monitor glucose concentration continuously in real time by measuring differential refractive index and calibrated by standard glucose solutions in a range of 0.1 to 1.0%. The possibility of industrial application of the device was demonstrated by real-time monitoring of glucose concentration in textile processing solutions such as desizing bath and cellulase treatment bath. Both of solutions contained glucose as a major degraded product. The device would be able to control the weight loss of cellulosic fiber during cellulase treatment since the amount of degraded products in a processing bath is proportional to its weight loss.