전단변형 효과를 무시하는 경우에 보존력을 받는 박벽공간뼈대구조의 자유진동 및 안정성해석을 위한 일반이론을 유도한다. 이를 위하여 비대칭 박벽단면의 임의점을 통과하는 부재축과 이와 직각을 이루는 두 개의 좌표축을 도입하여 직각좌표계를 정의하고, 이 좌표축을 기준으로 semitangential 회전의 2차항을 고려하는 변위장을 도입하여 연속체에 대한 가상일의 원리로 부터 운동에너지, 탄성변형에너지, 그리고 초기응력에 의한 포텐셜에너지를 유도한다. 이를 이용하여 선형분포하중을 받는 박벽공간뼈대구조의 자유진동 및 안정성해석을 위한 운동방정식을 제시한다. 3차 Hermitian 다항식을 변위파라미터의 형상함수로 사용하여 박벽공간뼈대부재의 질량, 탄성강성 및 기하학적 강성행렬을 산정할 뿐만 아니라, 임의의 위치에 작용하는 분포하중에 대한 하중보정강성행렬(load-correction stiffness matrix)을 제시한다. 본 이론 및 방법의 타당성을 검증하기 위하여 수치해석을 수행하고 문헌의 결과와 비교하여 정당성을 입증한다.

To determine an operational condition of an adhesion-type oil skimmer, it is important to estimate the withdrawal rate for a given driving velocity of the skimmer and material properties of the oil. As a theoretical model for this problem the formation of an oil film on a vertically driven flat plate is investigated. The previous steady-state analysis made in the field of coating industry are reviewed. These studies have been made under the assumptions of small Reynolds and capillary number, which is adequate for coating process but not for oil skimming. An alternative analysis based on the linear stability theory is made. Comparisons with the experimental results reveal that the stability analysis gives a correct estimation of the withdrawal rate for high capillary number at which the previous theory losses its validity.

Diglycidyl ether of bisphenol A(DGEBA)/4,4'-methylene dianiline(MDA)/phenyl glycidyl ether(PGE)-acetamide(AcAm)/carboxyl-terminated acrylonitrile butadiene copolymer(CTBN) 계의 열적 안정성을 평가하기 위해 열중량 분석법(TG)을 사용하였다. 활성화 에너지를 구하기 위해 Freeman & Carrol, kissinger, Flynn & Wall 식을 사용하였다. Freeman & Wall 식을 이용하여 구한 활성화 에너지는 112.9 kJ/mol, Kissinger 식에 의한 값은 151.5kJ/mol 이었으며, Flynn & Wall식에 의해 구한 값은 168.3 kJ/mol 이었다.

With the 14 m radio telescope at DRAO and the 4 m at Nagoya University, we have made detailed maps of 12 C O and 13 C O emissions from two Barnard objects B133 and B134 in the J = 1 → O rotational transition lines. Usual LTE analyses of the CO observations led us to determine the distribution of column densities over an entire area encompassing both globules. Total gas masses estimated from the column density map are 90 M ⊙ and 20 M ⊙ for B133 and B134, respectively. The radial velocity of B133 is red shifted with respect to B134 by 0.8 k m s − 1 , which is too lagre to bind the two clouds as a binary system. We have shown that the usual stability analysis based on the simplified version of virial theorem with the second time-derivative of the moment of inertia term ¨ I being ignored could mislead us in determining whether a given cloud eventually collapses or not. The lull version of the scalar virial theorem with the ¨ I term is shown to be useful in following up the time-dependent variations of the cloud size R and its streaming velocity ˙ R as functions of time. Results of our stability analysis suggest that B133 will eventually collapse in ( 2 ∼ 4 ) × 10 6 years.

A slope stability analysis has been done on Daesungri area by a computer program using limit equilibrium (Sarma method,1979). For this study, the authors modified the iteration technique and menu system of the algorithm which has been suggested by Hoek(1986). Sarma method is known as a suitable tool for evaluation of slope failure taking into account the kinematics of sliding blocks, and can be used for analysis of slopes of complex profiles such as circular, non-circular, planar sliding surfaces or any combination of these. The insertion of iteration technique and hydrodynamics in this method is very efficient, and gives an accurate estimate of static factor of safety. The analysis allows to specify different shear strength for each slice side and base, and therefore the submergence of any part of slopes is automatically analysed by taking the coordinates of phreatic surface. This program in combination with those stereographic technique developed by Appfied Geology Division of KIER(Korea Institute of Energy and Resources) in 1988 can be expected to give a useful result into evaluation of slope stability

In the case of conventional soft robots, the basic stiffness is small due to the use of flexible materials. Therefore, there is a limitation that the load that can bear is limited. In order to overcome these limitations, a study on a variable stiffness method has been conducted. And it can be seen that the jamming mechanism is most effective in increasing the stiffness of the soft robot. However, the jamming mechanism as a method in which a large number of variable act together is not even theoretically analyzed, and there is no study on intrinsic principle. In this paper, a study was carried out to increase the stability of the force chain to increase the stiffness due to the jamming transition phenomenon. Particle size variables, backbone mechanisms were used to analyze the stability of the force chains. We choose a jamming mechanism as a variable stiffness method of a soft robot, and improve the effect of stiffness based on theoretical analysis, modeling FEM simulation, prototyping and experiment.

In this study, the KS A ISO Guide 35 was applied to develop analytical standards for heavy metal cadmium using the Korean mussel (Mytilus coruscus) and to evaluate the homogeneity and stability of the sample. Some of the crucial characteristics that reference materials must consist include homogeneity and stability of both intra- and inter-bottles. We tested homogeneity using ANOVA analysis and short-term stability using regression analysis. The variations of cadmium concentrations did not significantly differ between intra- and inter-bottles (F=0.41, p=0.90). For short-term stability verification, cadmium analysis results were not statistically significant as a result of the regression analysis (significance F=0.51, p=0.53). This suggests that we can not dismiss the null hypothesis that there is no significant variation in concentrations of cadmium over time. These results indicated that the cryogenic-milling process has statistically proven the short-term stability for materials from mussels in the chemical analysis of cadmium. Therefore, we propose that the Korean mussel’s reference material developed for the proficiency test could be used as a tool to evaluate reliability and consistency in laboratories.

The National Environmental Specimen Bank (NESB) has set up a plan to develop reference materials in the facility for assuring analytical quality and validating analytical methods for its monitoring samples. Some of the crucial characteristics that reference materials must consist of are homogeneity and stability of both intra and inter-bottles. In this study, we examined the homogeneity and stability of cryogenically-milled muscle samples, from Common Carp (Cyprinus carpio) for total mercury. Homogeneity was tested using ANOVA analysis and regression analysis was used to test short-term stability. The variations of total mercury concentration did not significantly differ between the intra and the inter-bottle (F=0.8, p=0.37). Additionally, relative standard deviation of the total mercury concentration showed low values (2.28%). For the short-term stability test, total mercury variations were not statistically significant as demonstrated by the result of the regression analysis (F ratio = 3.11, p = 0.18). This suggests that the cryogenic-milling process has statistically proven the degree of homogeneity and short-term stability for samples of carp muscles in the chemical analysis for total mercury.

In this investigation, the reservoir stability was reviewed using hydrological and physical examination. The results of the review showed that, Both sites were analyzed to lack embankment height and sidewall height in the event of flooding, and it was considered that measures to increase stability should be established in the future by adding more dam cest and increasing side wall of a spill way. In addition, analysis and research will be necessary for other reservoir deteriorated in the future.

원양어선 제501 오룡호는 황천 중인 베링해에서 조업 후 피항하던 중 개구부를 통한 침수로 인하여 침몰하였으며 많은 선원들이 사망하고 실종되었다. 본 연구에서는 사고선박 침몰사고의 진행상황 별 유동수 영향과 어획물 배치 등을 고려한 선박복원성 계산을 KST-SHIP (선박안전기술공단 선박계산시스템)을 사용하여 수행하고 사고선박의 침몰사고 시의 침수 후 선박복원성을 분석하였다. 먼저 만재출항상태 (Full Load Departure Condition)에서의 사고선박의 비손상 복원성 계산서와 KST-SHIP을 사용한 비손상 선박복원성 계산 결과를 비교하여 검증하고, 사고선박의 출항 시부터 사고 직전까지의 배수량에 따른 비손상 복원성 계산을 수행하여 비손상 복원성을 분석하였다. 또한 사고선박 침몰사고 시의 진행상황 별 침수 후 선박복원성 계산을 수행하여 침수 후 복원성도 분석하였다.

본 논문에서는 수중운동체 중 하나인 잠수함의 코닝타워(Conning tower) 위치 및 제어판 형태에 따라 4가지 타입별로 나누어 회 전팔 시험(Rotating arm test)을 실시하였다. 또한 본 RA 시험을 통하여 유체력 미계수를 추정하였으며 수평면 운동에 대한 동적 안정성 (Dynamic stability)을 평가하였다. 특히, 자유수면의 영향으로부터 자유로운 심도비(Depth ratio) 6.0에서 힘과 모멘트를 측정한 후, 다중회귀 분석을 이용하여 유체력 미계수를 추정하였다. 최종적으로 선형유체력 미계수를 이용한 수평면 동적 안정성 지수를 산정함으로써 잠수함 타 입별 특성이 동적 안정성에 미치는 영향을 분석하였다.

The potato tuber is known as a rich source of essential nutrients, used throughout the world. Although potatobreeding programs share some priorities, the major objective is to increase the genetic potential for yield through breeding or to eliminate hazards that reduce yield. Glycoalkaloids, which are considered a serious hazard to human health, accumulate naturally in potatoes during growth, harvesting, transportation, and storage. Here, we used the AMMI (additive main effects and multiplicative interaction) and GGE (Genotype main effect and genotype by environment interaction) biplot model, to evaluate tuber yield stability and glycoalkaloid content in six potato cultivars across three locations during 2012/2013. The environment on tuber yield had the greatest effect and accounted for 33.0% of the total sum squares; genotypes accounted for 3.8% and G×E interaction accounted for 11.1% which is the nest highest contribution. Conversely, the genotype on glycoalkaloid had the greatest effect and accounted for 82.4% of the total sum squares), whereas environment and G×E effects on this trait accounted for only 0.4% and 3.7%, respectively. Furthermore, potato genotype ‘Superior’, which covers most of the cultivated area, exhibited high yield performance with stability. ‘Goun’, which showed lower glycoalkaloid content, was the most suitable and desirable genotype. Results showed that, while tuber yield was more affected by the environment, glycoalkaloid content was more dependent on genotype. Further, the use of the AMMI and GGE biplot model generated more interactive visuals, facilitated the identification of superior genotypes, and suggested decisions on a variety of recommendations for specific environments.

This study suggests a general process of analyzing the mooring and cargo handling limit waves, which is an incident to the new energy port under long wave agitation. To reduce damages of ships and harbor structures due to strong wave responses, it is necessary to predict the change of wave field in the mooring berth to make the proper decision by dock master. The berthing area at a new LNG port in the east coast of Korea in this study is frequently affected by oscillations from waves of 8.5~13s periods in the wintertime. The long period waves give difficulties on port operation by lowering the annual berthing ratio. It needs to find the event waves from the real time offshore wave records, which cause over the mooring limits. For that purpose, the wave records from field measurement and offshore wave buoy were analyzed. From numerical simulation, the response characteristics of long period waves in the berthing area were deduced with or without breakwater expansion plan, analyzing the offshore field wave data collected for two years. Some event wave cases caused over the cargo handling and mooring limits as per the standard Korean port design guideline, and those were used for the decision of port operation by dock master, comparing with the real time offshore wave observations.

We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.

Stability of labor market in rural areas was analyzed in this paper with categories of industrial group, employment scale, surviving period, and founder group. The stability of each classified labor market was compared with each other to figure out the stable business class and the unstable class in rural areas. The results of rural areas were compared with those of urban areas. The stability was analyzed with average and coefficient of variation (C.V.) of annual total employees’ change rates. It was revealed that labor market of ‘primary industry’, including agriculture, is unstable. Especially, labor market of ‘mid-size’ and ‘primary industry’ businesses founded as ‘incorporated company’ in rural areas is vulnerable. While labor market of ‘large-size’ is proved to be unstable, it is confirmed that ‘small-size’ or ‘mid-size’, and ‘over-ten-year survived’ businesses have positive contribution to the stable labor market in rural and urban areas. The results show that the stability of labor market is different in each category of business and in each region of rural or urban area. It is expected that the results can be utilized for the regional development policies, of labor and industry part.

We have studied the optimum location of the sensor to evaluate the condition of the structure by performing the structural analysis on the landing pier. It is judged that it is appropriate to place the strain sensor of the landing pier at the upper part, the middle part and the upper part of the pile at 30% below the pile.

Recently, it is a critical issue for Korea that Metropolitan Landfill site life extension was in crisis contrast for localresidents and local governments. In Europe and Japan, the generation of waste and landfills were suppressed and theyintroduced the MBT facility in order to increase the recycling and energy recovery. In this study, the process of domesticMBT facilities were evaluated by the physical and chemical composition, calorific value and biomass content, the aerobicbiodegradation of biodegradable waste by comparing and analyzing each step through the evaluation. Both organic residuesand inorganic residues carbon content discharged from the MBT analysis, moisture content, calorific value of residues didnot meet solid refuse fuels quality standards. While the biomass content and aerobic biodegradation higher than standardbiodegradable waste landfill in Europe. Biodegradable organic residue selected from domestic solid fuel manufacturingfacility is expected to be able to manage through the biomass content and biological stability analysis. Based on the resultsof future research it is needed to review the criteria and additional landfill energy recovery by incineration residues.

In this study, stability analysis was conducted for improved open-cut tunnel ground by preloading. The result of this study, vertical and unequal settlement was within the acceptable range. However, the field of soft ground can cause greater settlement than predicted. Therefore, the structure must be constructed in preparation for the differential settlement.