• Journal of the Korean Society for Railway
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• v.12 no.5
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• pp.811-818
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• 2009

An estimation method of the fallout volume of a tunnel under construction is proposed based on an empirical method called bulking factor. For this, the main causes of the tunnel fallout are investigated and the scale of the fallout which is not accessible is considered. The calculated height of the fallout area is compared with borehole core data and the accuracy and efficiency of the proposed method is demonstrated. Another experimental approach on the detection of a progressive cracking around the tunnel fallout is provided based on an acoustic emission method. From the field tests near the tunnel fallout, it is shown that additional progressive cracking of the reinforced area is not foreseen and the effectiveness of the reinforcement is proven.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1643-1645
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• 2004

변압기는 판토그래프를 이용하여 가선으로부터 전력을 공급받아 전력변환장치, 견인전동기 등의 각종 장치에 필요한 전원을 공급해주는 중요한 역할을 한다. 또한 전장품에서 가장 무겁고 부피가 큰 변압기는 차량의 주행 속도에 큰 영향을 미치고 변압기를 설치할 수 있는 공간상의 제약이 따르므로 소형, 경량화가 매우 필수적이다. 본 논문에서는 변압기의 오일온도와 외함온도의 변화를 확인하기 위해 차량에 취부된 변압기에 온도 센서를 부착하였다. 또한 한국형 고속전철이 운행하는 동안 변압기의 온도가 기준 온도를 넘어갈 경우 차량의 치명적인 고장을 일으킬 수 있으므로 차량 내에 상시 계측시스템을 설치하여 변압기의 온도를 실시간으로 감시하고 측정하였다. 이를 통해서 변압기의 온도 변화와 열적 특성을 분석할 수 있었다.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.232-233
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• 2000

초단펄스를 생성하는 방법에는 이득 스위칭, 광 변조기, 모드록킹 레이저 등이 있다. 이중에서 모드록킹 광섬유 레이저를 이용한 초단펄스를 발생시키는 방법은 비용이 많이 들고 부피가 큰 단점을 갖고 있지만, 매우 짧은 펄스 폭 생성, 고 출력의 펄스생성, 그리고, 파장 및 주파수를 조절을 할 수 있다는 장점을 갖고 있다. 한편, 모드록킹 방법에는 수동형과 능동형이 있다. 수동형 방법은 아주 짧은 펄스 폭을 갖는 펄스를 발생할 수 있지만, 출력이 불안정하고 펄스의 발생주기를 조절하기 어려운 반면, 능동형 방법은 상대적으로 펄스폭은 넓지만, 안정된 출력과 펄스 발생주기를 짧게 할 수 있다. 따라서, 고 반복률의 안정된 펄스를 사용하는 초정밀 광 계측기나 광통신에 사용되는 광원으로 능동형 모드록킹 광섬유 레이저가 많이 사용되어지고 있다. (중략)

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.7
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• pp.984-993
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• 2000

Characteristics of carbon soot particles generated in diffusion flames were studied. Non-sooting and sooting normal diffusion flames using propane or ethylene as fuel were selected. In the flames, soot volume fraction was measured by a thermocouple, and primary particle diameter and cluster size were analyzed by TEM photographs. The characteristics of soot particles depended on flame(non-sooting or sooting) and fuel(propane or ethylene) type. Unlike the sooting diffusion flames, particle growth and oxidation processes were clearly observed in the non-sooting diffusion flames. In the sooting diffusion flames, soot particle size was slightly changed at the flame tip.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.7-8
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• 2014

본 논문은 다이폴 코일 공진방식(DCRS, Dipole Coil Resonant System)을 사용한 원격 무선전력전송 개발 사례를 소개한다. 제안된 다이폴 코일 공진방식은 기존의 자기결합 공진방식(CMRS, Coupled Magnetic Resonance System)에 비하여 송신, 수신코일로만 이루어진 간단한 코일 구조와 작은 부피를 가지며, 공진도 Q를 100이하로 설계하여 주변 환경 변화에 강인한 전력전달 특성을 가진다. 본 논문에서는 원전 중대사고 시 격납건물 필수계측기용 소형 비상전원으로 개발된 10W급 7m 원격 무선전력전송 장치의 구성 및 설계과정을 제시한다.

• Analytical Science and Technology
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• v.12 no.5
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• pp.428-435
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• 1999

A method for measuring Rn-222 and Ra-226 in aqueous sample using liquid scintillation counting technique has been studied. The Rn-222 was extracted easily from the water sample (10 mL) by 12 mL of xylene based organic scintillant. After radioactive equilibrium between Rn-222 and its alpha emitting decay products for three hours, the alpha activity from Rn-222 and its decay products were measured in a scintillation vial using the Wallae $1220^{TM}$ Quantulus liquid scintillation counter. Ra-226 concentration in aqueous sample was determined, after isolation of Ra-226 from the sample matrix, by extraction the ingrowth of the Rn-222 and its alpha emitting decay products with xylene based organic scintillant. The optimum pulse-shape analysis (PSA) value was evaluated by the figure of merit (FM) criterion. Minimum detectable activity (MDA) is about 0.14 Bq/L (3.78 pCi) for the region of Rn-222 and its alpha emitting decay products and 0.06 Bq/L (1.63 pCi) for the region of Po-214 respectively, with 200 min, counting time at PSA level 100 in the low-diffusion polyethylene vial and xylene based cocktail solution. Experiment on the optimum sample-cocktail volume ratio, the influence of agitation and the diffusion of radon from vial were carried out.

• Journal of Sasang Constitutional Medicine
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• v.10 no.1
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• pp.143-160
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• 1998

PURPOSE This studied the biomechanical body segment parameters of Korean adults with reference to Sasang Constitutional Medicine(SCM). We anlyzed the characteristics of Sasang constitution through Body Measurement, Immersion Method, and Reaction Board Method. SUBJECT Subjects were 72 persons. There were made 49 and Female 23. Mean age was . And There were Taeumin 30, Soyangin 17, and Soeumin 25. METHOD The items of Body Measurement were 51. Limbs were measured right side. Volume was gained with Immersion Method and Weight was calculated with the density equation for limbs from Drills and Contini. Center of Mass was gained with Reaction Board Method. RESULT 1. In Body Measurement there were the significant differences with each constitution of man's circumference. 2. In Volume there were the significant differences between Taeumin and Soeumin in mand. And the volume rate of head and neck, hand, and foot was the lowest in Taeumin, but the highest in Soeumin. 3. In center of mass Soyangin was higher than others.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.3
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• pp.130-137
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• 2021

Purpose: The various suture techniques can be utilized in order to maximize the keratinized tissue healing around dental implants. The aim of this study is to compare the soft tissue healing pattern between two different suture techniques after implant placement. Materials and Methods: 15 patients with 18 implants were enrolled in this study. Simple implant placement without any additional bone graft was performed. Two different suture techniques were used to tug in the mobilized flap near the healing abutment after paramarginal flap design. Digital intraoral scan was performed at baseline, post-operation, stitch out, and 3 months after operation. The scan data were aligned using multiple points such as cusp, fossa of adjacent teeth, and/or healing abutment. After subtracting scan data at baseline with other time-point results, closed space indicating volume increment of peri-implant mucosa was selected. The volume of the close space was measured in mm³. The volume between two suture techniques at three time-points was compared using nonparametric rank-based analysis. Results: Healing was uneventful in both groups. Both suture technique groups showed increased soft tissue volume immediately after surgery. The amount of volume increment significantly decreased after 3 months (P < 0.001). Flap folding suture group showed higher median of volume increment than interrupted suture group after 3 months without any statistical significance (P > 0.05). Conclusion: After paramarginal flap reflection, the raised flaps stabilized by flap folding suture showed relatively higher volume maintenance after 3-month healing period. However, further studies are warranted.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.4
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• pp.280-286
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• 2011

In this research, the oil detection method and the characteristic of sensor using the selective reaction of silicone rubber in response to hydrocarbon oil will be described. As a sensing principle, the swelling property of silicone rubber in response to hydrocarbon fuel is used, also a strain gauge is used to transduce the volume change to an electrical signal. The sensor core is manufactured with a strain gauge embedded in silicone rubber by the curing process and experiments for characteristics of sensor core with various oils were carried out. It is shown that the sensor core can be used as an oil spill detection sensor. Also, for the application to the sea area, a buoy type sensor platform is integrated with a sensor core and a strain amplifier and it is tested in the simulated oil spill condition. In this study, it is proven that the integrated sensor can be used for the detection of various oils.

• Journal of the Korean GEO-environmental Society
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• v.11 no.12
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• pp.5-11
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• 2010

If the groundwater in rock joint is changed into ice, it induces the stress increment by volume increase. Also, if the ice is changed into groundwater again, the stress in joint decreases by volume decrease. The accumulated displacement and fatigues of joints are increased by the stress-hysterisis, induced from the continuous frost-thawing. Also the shear strength is decreased by them continuously. The stress-hysterisis is affected by the atmospheric temperature changes, whose behavior is visco-elasticity, usually. Therefore, Kelvin model could be used to analyze the frost-thawing behavior in winter. The measured data of total 5 points are examined, which are composed of 3 points of shallow joints and 2 points of deep joints. Because shallow weathered rocks have many joints, a lot of Kelvin model are connected and the behaviors are complicated. In case of deep joints, simple Kelvin model is applied and the behaviors are also simple.