• Tunnel and Underground Space
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• 제8권1호
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• pp.67-73
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• 1998

This paper presents the results of deformation measurement and numerical analysis carried out to study the behaviour of the rock mass around large underground oil storage caverns. Displacements during excavation have been monitored using borehole extensometers which had been installed before the excavation of caverns proceeded. Numerical analysis has been carried out to examine the three-dimensional behaviour of rock and the face advance effect. The input parameters for this analysis were determined from the results of laboratory and field tests. The deformation modulus of the rock mass was determined from plate loading test at the site and in-situ stresses were measured from the overcoring method with USBM deformation gauge. The results from this study gave a clear picture for three-dimensional behaviour of the rock mass, hence would be used for the optimum design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1535-1538
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• 2005

We present a mass productive and reproducible assembly technique of a single bundle of single-walled carbon nanotubes (sb-SWNTs) using dielectrophoresis (DEP). Gold electrodes with 10 gaps made via microlithography were used to align the carbon nanotubes (CNTs). The magnitude and type of applied electric field were investigated to verify their effects on CNT assembly. The optimum assembling conditions in which sb-SWNTs could be positioned at a desired site were experimentally identified, and the characteristics of the assembled sb-SWNTs were evaluated from AFM, Raman spectroscopy, and I-V curve. This assembly method has potential for applications such as gas sensors or electronic devices.

• Journal of the Korean Society of Marine Environment & Safety
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• 제8권1호
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• pp.127-137
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• 2002

This paper deals with developing a Web-based Solver NRO(Network Reliability Optimizer) for solving three classes of reliability redundancy optimization problems which are generated in series systems. parallel systems and complex systems. Inputs of NRO consisted in four parts. that is, user authentication. system selection. input data and confirmation. After processing of inputs through internet, NRO provides conveniently the optimal solutions for the given problems on the Web-site. To alleviate the risks of being trapped in a local optimum, HH(Hybrid-Heuristic) algorithm is incorporated in NRO for solving the given three classes of problems, and moderately combined GA(Genetic Algorithm) with the modified SA(Simulated Annealing) algorithm.

• Explosives and Blasting
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• 제20권3호
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• pp.59-71
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• 2002

The points of this design case are the planning and excavation method of a new double-tracked railroad tunnel which is approx. 11∼22 meters apart from existing single-tracked railroad tunnel. For the optimum excavation method some needs are required in design stage, such as the reduction of noise and vibration, public resentment, damage of buildings and construction costs. Hence the estimation and application of allowable noise and vibration criterion is important. The ground coefficient (K, n) of this site is determined by field trial blasting. The excavation method is chosen to satisfy the allowable noise and vibration criterion. In addition, in order to ensure the stability of existing single-tracked railroad tunnel, the instrumentation of maintenance level is accompanied during the construction stage. As a result of this design condition, central diaphragm excavation with line drilling and pre-large hole boring blasting is applied to the area within 15 meters apart from existing tunnel. And above 15 meters apart, pre-large hole boring blasting is designed.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.979-984
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• 2002

The mat foundation of Tower Palace III is designed as a massive structure which has a 3.5m depth. The purpose of this study is to determine the optimum mix design having good workability and to control the actual concrete quality in site. For this purpose, we select the Self Compacting Concrete. Recently, the Self Compacting Concrete has been applied to achieve workability improvement. As the result of actual application, we have finished placing the mass concrete of 8, 000m$^3$ during 14hours with good success and obtain the good quality concrete. All test results are satisfied with our specifications for mat foundation and cut cost as the reduction of placing hours.

• Journal of Korean Institute of Industrial Engineers
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• 제12권1호
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• pp.43-48
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• 1986

In this paper, the one period multi-item inventory model is considered in which it is required to determine the production quantity and selling price of each item which maximize the probability of realizing predetermined level of profit. The objective function of this model is the sum of weighted probabilities which represent the possibility of obtaining the predetermined level of profit for each item. Budget constraint, inventory site constraint and constraints of price are considered. Finally this paper shows a numerical example in which random demand of each item has exponential distribution.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.405-409
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• 2004

We chose the Kushiro wetland in Hokkaido, Japan, as a test site to monitor wetland areas. Synthetic aperture radar (SAR) can carry out continuous observation in any weather conditions, and can therefore be used to observe high humidity areas such as wetlands. We applied multi-parameter SAR data (dual-frequency, multi-polarization, and multi-incidence angle) to monitoring the wetland forest. To find the optimum incidence angle and polarization for monitoring the wetland biomass, a simple backscattering model of wetland vegetation was developed and applied to estimate backscattering coefficients for different biomass and surface conditions.

• Solar Energy
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• 제4권2호
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• pp.3-12
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• 1984

In this paper, how to design the wind power generation system is presented. It is shown that the wind system optimization can be achieved by consideration of the four factors; wind statistics, efficiency of conversion of wind energy to electrical energy, average annual energy extracted and load factor. The wind is characterized by a weibull probability function. The Weibull parameter is calculated for the characterizing wind and the primary design specification of ten different sites. Some graphs are presented, which can be used to design a wind system for maximum output of a specified load factor at given site. Two different systems, $V_c=0.4V_R$ and $V_c=0.5V_R$ are discussed, as samples, for investigation of the effects on the system through the variation of cut-in speed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.67-67
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• 2010

PV module has many power loss factor in the site. Among them, one thing is series resistance. Especially interconnection ribbon resistance is one of the power loss. In this paper, we study interconnection ribbon resistance of the PV module material. In the field, high temperature can pile ribbon resistance on the PV modules. We can do better choice in the optimum use of ribbon through checking relation of ribbon dimension and resistivity. From this point of view, different solder type and dimension was treated.

• Radiation Oncology Journal
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• 제2권1호
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• pp.49-58
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• 1984

53 patients of previously untreated Stage I&II Non-Hodgkin's Lymphoma in head and neck treated with irradiation at Yonsei Cancer Center from January, 1970 to December, 1978 were retrospectively analysed. 5 year survival rate and 5 year disease free survival rate were $51.5\%\;and\;42\%$. Local control rate by irradiation was $92.4\%$ with mainly $4,000\~6,000$ rads. 21 patients suffered relapses after radiotherapy, 4 cases recurred within irradiated area, 4 cases at contiguous site of irradiation field, and 13 cases recurred at distant area, more commonly below diaphragm. Most cases relapsed within 1 year 6 months after treatment. Optimum irradiation field for head and neck localized lymphoma, prognostic factors ana usefulness of chemotherapy are also discussed.