• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.202-209
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• 1998

A three-dimensional numerical method based on the Green's integral equation is developed to predict the motion response and drift force in waves for the ocean monitoring facilities. In this method, we use source and doublet distribution, and triangular and rectangular eliments. To eliminate the irregular frequency phenomenon, the method of improved integral equation is applied and the time-mean drift force is calculated by the method of direct pressure integration over the body surface. To conform the validity of the present numerical method, some calculations for the floating sphere are performed and it is shown that the present method provides sufficiently reliable results. As a calculation example for the real facilities, the motion response and the drift force of the vertical cylinder type ocean monitoring buoy with 2.6 m diameter and 3,77 m draft are calculated and discussed. The obtained results of motion response can be used to determine the shape and dimension of the buoy to reduce the motion response, and other data such as the effect of motion reduction due to a damper can be predictable through these motion calculations. Also, the calculation results of drift force can be used in the design procedure of mooring system to predict the maximum wave load acting on the mooring system. The present method has, in principle, no restriction in the application to the arbitrary shape facilities. So, this method can be a robust tool for the design, installation, and operation of various kinds of the floating-type ocean monitoring facilities.

• Nuclear Engineering and Technology
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• v.13 no.4
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• pp.264-276
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• 1981

A simulation procedure which can represent time-dependent nuclear characteristics of TRIGA Mark-III reactor is developed. CITATION, a multi-group diffusion-depletion program, has been utilized as calculational tool. The group structure employed in this study consists of 7 groups: -3-fast and 4-thermal-which is conventionally utilized in TRIGA type reactor analysis. Three-dimensional nuclear characteristics are synthesized by combining results from two-dimensional plane calculation and two-dimensional cylinder calculation, since direct three-dimensional approach is not yet possible. An effort ia made to develope a method which can extract effective zone and group dependent bucklings by neutron diffusion theory rather than conventional zone and/or group independent Ducklings by neutron transport theory, since neutron leakage is quite high for small core such as research reactors. It is turned out that the method developed in this study gives satisfactory results. The calculation is performed under assumptions that all control rods are fully withdrawn, that no samples are inserted in the irradiation holes and that the core is located in the center of the reactor pool. Burnup-dependent variation of core excess reactivity, time dependent change of Xe-135 poisoning and reactivity worth of rotary specimen rack are calculated and compared with operation records. Neutron flux and power distribution as well as neutron spectrum in each irradiation .facility are presented.

• Progress in Medical Physics
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• v.16 no.4
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• pp.176-182
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• 2005

Stereotactic radiosurgery (SRS) is a technique to deliver a high dose to a target region and a low dose to a critical organ through only one or a few irradiation. The SRS must be planned exactly. Currently the surgery plan is peformed by trial and error method. There are many questions about the reliability and reproducibility of the plan result. This study Improve each step of the Oh's method based on heuristic target shaping to obtain the better result. The target was reconstructed using cylinders with same height and the neighbored cylinders were combined according to the difference of each center and diameter. Then, spheres were packed within each cylinders by the packing rules. Two virtual targets were used to compare this method with Oh's method. As a result, the numbers of isocenter were successfully reduced - more than $35\%$ and $26\%$ - without serious differences of proscription isodose to tumour volume ratio (PITV) and maximum dose to proscription dose ratio (MDPD). This technique using cylinder piling and sphere packing will be a helpful tool to planner in stereotactic radiosurgery.

• Journal of the Korean Institute of Gas
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• v.19 no.4
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• pp.29-34
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• 2015

Accidents in laboratory dealing with chemicals have constantly occurred. In the case of a gas explosion or an accident related to leakage of chemical materials, the damage is much greater, thereby leading to a serious accident. Especially, the safety of laboratory in University is important because students build up knowledge and skills and accumulate experience as the main researchers. In this paper, 5 gases(CO, $NH_3$, $H_2$, $CH_4$, $N_2$) are selected to model since they are often used in university laboratories. From the scenarios where the gases are released, the diffusion process is estimated and analyzed to predict damage degree by PHAST v.6.7. Internal diffusion process is modeled through FLUENT which is Computational Fluid Dynamics(CFD) tool. Also, we compare indoor damage with outdoor one when discharged to the outside through the laboratory's window. In the modeling results, the outdoor damages for accident scenarios in the results are far less than then of real plants since the vessel usually used in laboratory(i.e. the capacity of the cylinder; 47 L or less) is significantly less than workplace's one(using ton measure). However as shown in the results small amount can have high consequences for indoor accidents.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.3
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• pp.113-120
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• 2014

Packaging has played important function on marketing as a silent salesman. As an interface of consumer and products, packaging fulfills several functions such as protection, sales promotion, communication and convenience during the distribution process. For the appearance of self-service sales method, packaging could be regarded as important salesman influencing consumers' preference on shelf in the shop. In this study, Vitamin water was selected as the proper target product for lower impact of prices and brands. With previous studies, Vitamin water packaging elements were classified as 'packaging material', 'packaging shape', 'label color', 'logo layout', then each packaging element was consist of details. To measure the influence of each packaging element on consumers' preference quantitatively and to minimize respondent's subjective judgment, Analytic Hierarchy Process (AHP) was used as a tool. Through AHP result, packaging element of the most influence on consumers' preference is 'label color (0.370)', and 'container shape (0.246)', 'container material (0.230)', 'logo layout (0.154)' was in order. Among the detail packaging element, 'plastic (0.405)' has the greatest influence in 'container material' and 'cylinder (0.423)' in 'container shape', 'magenta (0.329)' in 'label color', 'vertical layout (0.572)' in 'logo layout'.