• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1071-1074
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• 2008

In this study, the behavior of dredged soil was measured by repeated tide and analyzed the change of settlements and cone penetration resistance by centrifuge model about dredged soil of Kunsan-Janghang site that maximum tidal range is 7.4m. Consequently the settlements of dredged soil by repeated tide in the 2nd month was 0.489 m. After 12th month, the total settlements was 0.524 m in the model. It meaned the settlements of dredged soil by repeated tide in the 2th month was 80% of the settlements. Also, with the lapse of time, cone penetration resistance increased centrifuge model test for catching the strength change of dredged soil by repeated tide. After 10th month, there were not almost changes. cone penetration resistance in 10th month was measured more 3.5~5.6 times than that in its early stages. Also, with the lapse of time, cone penetration resistance increased almost linearly. And, when we surveyed the relation between cone penetration resistance and time, as depth increased, cone penetration resistance rose.

• 천문학회보
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• 제39권1호
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• pp.72.2-72.2
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• 2014

We have made a comparison of three cone models (an asymmetric cone model, an ice-cream cone model, and an elliptical cone model) in terms of space weather application. We found that CME angular widths obtained by three cone models are quite different one another even though their radial velocities are comparable with one another. In this study, we investigate which cone model is proper for halo CME morphology and whether cone model parameters are similar to observations. For this, we look for CMEs which are identified as halo CMEs by one spacecraft and as limb CMEs by the other ones. For this we use SOHO/LASCO and STEREO/SECCHI data during the period from 2010 December to 2011 June when two spacecraft were separated by $90{\pm}10$ degrees. From geometrical parameters of these CMEs such as their front curvature, we classify them into two groups: shallow cone (5 events) and near full-cone (28 events). Noting that the previous cone models are based on flat cone or shallow cone shapes, our results imply that a cone model based on full cone shape should be developed. For further analysis, we are estimating the angular widths of these CMEs near the limb to compare them with those from the cone models. This result shows that the angular widths of the ice-cream cone model are well correlated (CC = 0.81) with those of observations.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2534-2539
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• 2007

Launch vehicles are exposed to aerodynamic heating conditions while flying at high Mach numbers in the atmosphere. In this study aerodynamic heating test for fairing nose-cone was done using ATSF(Aerodynamic Thermal Simulation Facility) and Engineering Model for fairing. ATSF is a facility that can simulate given temperature profile using about 4,000 halogen heaters on fairing model. Aerodynamic heating profile is got from result of thermal analysis using MINIVER, Thermal Desktop and SINDA/FLUINT. After aerodynamic heat test, it is found that initial temperature of fairing inner surface and thickness of BMS has important effects on temperature of fairing inner surface. Also it is confirmed that maximum temperature of fairing nose-cone inner surface during flight is lower than allowable temperature limit. Later, thermal correlation between thermal analysis and experimental results will be done using aerodynamic heating test result

• 항공우주시스템공학회지
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• 제7권3호
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• pp.33-38
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• 2013

The air data measured from the static pressure, the dynamic pressure and etc. of an airplane is used for calculation of many flight parameters(altitude and airspeed and so on) and these values applied to flight safety and navigation flight. The pitot-static system of the development airplane is calibrated by finding of pitot-static system's error using tower fly-by, trailing cone method and etc. This paper is describing for the introduction of the trailing cone method and major items for test planning, preparation, operation and results for air data calibration flight test performed, considering efficiency and safety during KC-100 development project.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.206-212
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• 2009

Chemical behaviors of each surface material for interior facilities affect to fire initiation and growth in general fire situation. These chemical behaviors were characterized by thermal properties (Heat release rate, Pyrolysis rate, specific heat, etc) which could be derived from experimental test. Especially, Heat release rate which indicates aspect of fire size is one of the most important property to asses fire hazard and protection needs. The cone calorimeter test (ISO 5660) has recently assumed to a dominant role in bench scale fire testing to obtain the Heat release rate of materials. This value could be calculated by the 'Oxygen Consumption Method' under various producing irradiances to each surface of materials. In this study, Process of the cone calorimeter test was simulated by Pyrolysis model of FDS (Fire Dynamics Simulator by NIST) base on the ISO 5660 international standard. Then, we could estimate the simulation method of FDS in case of single materials through the comparative study with test results.

• 한국안전학회지
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• 제26권6호
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• pp.20-25
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• 2011

This study presents on the fire hazard analysis of communication cable in buildings. In order to analyze fire hazards for communication cable IEC 60332-1, UL 94 and cone calorimeter test are conducted. The number of cable used to experiment is 10 communication cable which are generally applied to data communication in buildings. The results show that 9 cables do meet the performance requirement of IEC 60332-1 and 8 cables are V-0 classification. IEC 60332-1 and UL 94 test are inadequate for fire hazard classification. The various parameters obtained by cone calorimeter test such as HRR, peak HRR, smoke production rate and so on. Also it is able to evaluate multiply fire hazard for communication cable with cone calorimeter test results.

• 자원환경지질
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• 제50권2호
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• pp.145-157
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• 2017

최근 집중강우로 인하여 전국적으로 산사태 및 사면붕괴 현상이 빈번히 발생하고 있다. 이러한 산지 및 비탈면에서 발생하는 자연재해에 대한 대책안 마련 및 설계 입력자료로서 지반의 강도정수(전단강도)를 도출해야만 한다. 그러나 현재 산지 및 비탈면에 접근하여 지반조사를 하기 위해서는 과다한 산림훼손과 많은 경제적인 비용 등이 요구되어진다. 따라서 본 연구에서는 현장에서 인력운반이 가능한 경량화된 소형동적콘관입시험기를 제작하여 다수의 지역에 대한 지반의 특성 및 강도정수를 산출하였다. 그리고 국내 및 외국의 소형동적콘관입시험 방법에 대해서 연구 분석하여 국내에 적합한 콘 재료와 시험방법을 제안하였으며, 대표적인 지역을 대상으로 현장에서 콘관입시험 Nc값과 표준관입시험 N값과 비교 분석하였다. 이와 더불어 직접전단시험 및 공내전단시험을 실시하여 토층심도별, 기반암별, 흙의 분류별 그리고 #200번체 통과량별로 Nc값과 전단강도와의 상관관계를 분석하였다. 특히 본 연구에서는 산지조건에서 가장 많이 분포하는 사질토를 대상으로 Nc값에 대응하는 전단강도(점착력 및 내부마찰각)와의 상관식을 제안하여 산지 토층에 대한 효율적인 지반강도정수를 산출하도록 하였다.

• 한국지반공학회논문집
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• 제26권8호
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• pp.15-25
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• 2010

점토층 사이에 존재하는 모래 협재층은 연약지반 거동에 중요한 영향을 미친다. 협재층은 주로 표준 콘(단면적: $10cm^2$)에서 측정된 지반의 저항력과 간극수압 값을 이용하여 평가하고 있지만, 높은 해상도를 위하여 소형 콘이 널리 활용되고 있다. 본 논문의 목적은 연약지반에 얇게 분포된 협재층을 선단저항력, 주면마찰력 그리고 전기비저항을 이용하여 평가할 수 있는 전기비저항 콘(Cone Resistivity Penetrometer, CRP)을 개발하고 적용하는 것이다. CRP는 각각 실내실험(단면적: $0.78cm^2$, 직경: 1.0cm)과 현장실험(단면적: $1.76cm^2$, 직경: 1.5cm)에 활용되도록 제작하였으며, 길이는 표준 콘(단면적: $10cm^2$, 직경: 3.57cm)의 단면적과 마찰부의 면적비를 고려하여 제작하였다. 실내실험은 모래와 점토가 반복적으로 조성된 다층의 층상탐지 셀을 사용하여 각 지층의 경계면을 탐사하였으며, 현장실험은 광양지역에서 심도 6m부터 15m까지 관입실험을 수행하였다. CRP는 실내실험에서 측정된 선단저항력과 전기비저항으로 조성된 시료의 각 지층 경계면을 뚜렷하게 평가하였으며, 현장실험에서는 3개의 협재층을 탐지하였다. 본 연구에서 개발된 CRP는 실내 및 현장결과 적용성이 뛰어나 추후 유용하게 사용될 것으로 판단된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.180-183
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• 2004

Superplastic formability depends on flow parameters such as temperature, strain rate, strain and stress, microstructures. Usually, superplastic properties of materials are characterized with using a uni-axial tension testing. However, superplastic sheet is formed under mutiaxial loading condition in most forming practices. In the present study, superplastic characteristics of A15083 alloys were determined with using both a uni-axial and biaxial bulging tests. Specially, cone-type die was used to achieve constant strain rate under constant pressure condition. Even though constant strain rate under a certain pressure was achieved only approximately, a cone-type bulging test was found to be quite beneficial to get a multiaxial formability of superplastic materials.

• 한국산림과학회지
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• 제97권5호
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• pp.516-524
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• 2008

We investigated on the distribution of nutrient contents (N. P and K) in current and one-year old needles of Korean pine, Pinus koraiensis, to understand the physiological effects of alternate bearing. One experimental set was designed with three types of cone number (one, three and five) under natural state and cone number of another one was controlled by thinning. Test samples were separated to collect into three fractions; current needles on the shoot and one-year old needles above and under the cone. On the branch without cone, N, P and K concentrations in needles on the shoot were higher than those in needles of one-year old branch. At natural state, needle P concentration was the lowest in needles on the five-cone branch in August. Macronutrient concentrations were the lowest in needles above the cone, which was remarkably observed in needle K concentration. Under cone thinning, N. P and K concentrations were the highest in needles on one-cone branch and the lowest in needles on five-cone branch. Needle nutrient concentrations were the lowest in needles above the cone, which was remarkably observed in the needle on five-cone branch. In conclusion, the current needles of the shoot and cones are a strong sink of nutrient like N. P and K, and the increase of cone number influences nutrient removal from needles.