• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.11
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• pp.922-931
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• 2017

This research paper describes design procedures and those verification with multi-body dynamic analysis and an experiment for the development of an unprecedented type of canister cover, named as the separating cover. In order to overcome drawbacks from the precious rupture type and actuator driven cover, the separating cover was suggested. It has the simplest structure composed of the previously developed explosive bolt and a spring-lever driven system. First of all, mechanical feasibility with proposed design parameters based on mathematical modeling was confirmed through dynamic analysis and then its results showed good agreement with the followed empirical results acquired from a high speed camera. On top of that, a parametric study was conducted to identify the effect of each design parameter on separating performance. It is highly expected that this research contributes to provide military industries with a brand new canister cover having simplicity and cost efficiency and thus it will be very useful in MLRS(Multiple Launch Rocket System).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.2
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• pp.53-69
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• 2000

For the case of the capacity increase of Masan-Changwon wastewater treatment plant, the changes of near-field dilution rates due to the increased discharges into Masan Bay from the submerged multipart-diffuser were predicted by using CORMIX model. As the increase of wastewater discharges from currently 280,000 m3f day to 720,000 m3fday by 2011, the dilution rates become much lower than the present rates. To enhance the reduced dilution rates, the engineering design changes of diffuser length and alignment were considered as an optimal engineering option. According to the results of the model simulations for these changes, the dilution rates were increased in the strong ambient current of spring tide, but they were not affected by these changes in the weak current of neap tide in Masan Bay. From the analysis of oceanographic survey data, new outfalls sites have been searched. A promising outfalls site is selected and proposed on the basis of maximum obtainable dilution rates predicted by the model simulations.

• Clean Technology
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• v.15 no.1
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• pp.16-22
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• 2009

In this study, a fiber reinforced plastic (FRP) pipe with superior wear resistance was developed to replace the fly ash pipe of cast iron. Wear test was performed with various combinations of SiC filler and resin materials of unsaturated polyester, vinylester, epoxy, and phenol. Test results of ASTM D4060 showed the optimal combinations of resin, filler size, and resin/filler ratios. Test results of comparison between FRP and cast iron showed the possibility to replace cast iron pipe with the FRP pipe. Field test executed to compare the wear resistance between cast iron pipe and developed FRP pipe showed the superiority of the FRP pipe.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.499-503
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• 2009

Y. R$\acute{e}$ball$\acute{e}$ [11] discussed the representation of necessity measure through the Choquet integral criterian. He also consider a decision maker who ranks necessity measures related with Choquet integral representation. In this paper, we consider a decision maker have an "ambiguity"(say, interval-valued) necessity measure according to their Choquet's expected utility. Furthermore, we prove two theorems which are weak Choquet integral representation of preferences with a monotone set function for interval-valued necessity measures and strong Choquet integral representation of preferences with an interval-valued utility function for necessity measures.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.271-277
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• 1975

한국재내산양(韓國在來山羊) 11두(頭)의 흉벽근(胸壁筋)을 절개하여 관찰하였던 바 다음과 같은 결과(結果)를 얻었다. 1. 산양(山羊)의 흉벽(胸壁)에는 횡격막을 포함하여 11개의 筋들을 확인할 수 있었다 : 전배거근(前背鋸筋) M. serratusdorsalis cranialis, 후배거근(後背鋸筋) M. serratus dorsalis caudalis, 사각근(斜角筋) M. scalenus, 늑횡근(肋橫筋) M. transversus costarum, 늑골거근(肋骨擧筋) Mm. levatores costarum, 외늑간근(外肋間筋) Mm. intercostales externi, 내늑간근(內肋間筋) Mm. intercostales interni, 늑연골간근(肋軟骨間筋) Mm. intercartilaginei, 늑골후인근(肋骨後引筋) M. retractor costae, 흉횡근(胸橫筋) M. transversus thoracis, 횡격막(橫隔膜) Diaphragma. 2. 전배거근(前背鋸筋)의 발달이 아주 미약하여 단지 1예(例)에서만 볼 수 있었다. 3. 사각근(斜角筋)은 천부(淺部)(M. scalenus supracostalis)와 심부(深部)(M. scalenus primal costae)로 구분되었으며 이들은 각각 배(背), 복(腹)으로 나누어졌고, 천부(淺部)는 제 1늑골 및 제 3~4늑골에서 기시(起始)하고 있었다. 4. 늑연골간근(肋軟骨間筋)은 제 7늑간에서는 양쪽 늑골이 서로 밀접하게 붙어있어 나타나지 않았으며, 제 1늑간 부터 제 6늑간 사이에서는 섬유방향이 거의 수평으로 향하고 있어 내늑간근(內肋間筋)의 연장으로 보이고 제 8늑간 부터 마지막 늑간사이에서는 거의 수직으로 향하고 있어 외늑간근(外肋間筋)의 연장으로 보인다.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.733-740
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• 2017

'The facilities standards of water supply' issued by the Ministry of Environment in 2004 indicates that expansion joints cannot be used in welding water supply steel pipes. However, their reason is not clear and it is difficult to confirm the stability of the steel pipe for a water supply pipeline. The purpose of this study is to determine whether or not an expansion joint is necessary to improve the stability of water supply in steel pipe through a displacement analysis of the pipework. The test results are as follows. Firstly, it was found that expansion and contraction of the water supply steel pipe (D 2,400 mm) occur repeatedly in 4 cycles per year, and the maximum expansion and contraction amount of the pipe is 13.03 mm in 1.24 km pipelines. Secondly, the thermal stress caused by expansion and contraction of the steel pipe is $13.7{\sim}36.1kgf/cm^2$ according to the burial depth (0~4 m). The main comparison factors to determine the stability of the steel pipe (STWW 400) were the allowable tensile strength and the fatigue limit, which were computed to be $4,100kgf/cm^2$ and $1,840kgf/cm^2$, respectively. Finally, the thermal stress of the steel pipe is very small compared to the allowable tensile stress and fatigue stress. Therefore, thermal stress does not affect the stability of the steel pipe, although the expansion and contraction of the steel pipe occurs by temperature changes. In conclusion, the study demonstrated that expansion joints are not required in water supply steel pipelines.

• Korea and Global Affairs
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• v.2 no.2
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• pp.63-88
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• 2018

The purpose of the present paper is to examine the North Korean refugee protection system and its shortcomings. Based on the findings from the analysis of legal system and status of personal protection, this paper proposes the following measures to solve the problems and improve South Korea's existing system. First of all, personal protection for North Korean refugees should be carried out in an inclusive and humanitarian manner. Secondly, the collaborative governance operating system for protecting North Korean refugees should be established. Lastly, clear guidelines for personal protection procedures should be developed to ensure personal protection officers'accountability.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.139-145
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• 1992

A planning method of optimum forest road was tested in the compartment II of Kangweon National University Forests by using a digital terrain model under four evaluation factors, i. e., minimum road length, average skidding distance, exploitative index, and ratio of inaccessible points. The results of the study were as follows : 1. Optimum forest road design based on the minimum road length was shown as 6035.6m, 12.73m/ha, 279.9m, 1.43, and 15.7% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 2. Optimum forest road design based on the average skidding distance was shown as 7828.5m, 16.52m/ha, 198.4m, 1.31, and 4.0% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 3. Optimum forest road design based on the exploitative index was shown as 7410.6m, 15.64m/ha, 210.9m, 1.26, and 5.0% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively. 4. Optimum forest road design based on the ratio of inaccessible points was shown as 8307.1m, 17.53 m/ha, 184.9m, 1.29, and 2.5% for total road length, forest road density, average skidding distance, exploitative index, and ratio of inaccessible points, respectively.

• Korean Journal of Food Science and Technology
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• v.8 no.3
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• pp.161-171
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• 1976

The meat samples of carp (Cyprinus carpio, Linne) and rainbow trout (Salmo gairdnerii) packaged in aluminum pouches with polyethylene adjuvant were exposed to gamma radiation of doses up to 1.5 Mrad for the purpose of determining optimum dose range required to bring about a significant storage-life extension at refrigerated temperatures. The maximum permissible dose for carp was determined to be 1.5 Mrad and that for rainbow trout 0.2 Mrad, while the optimum dose was 0.25 Mard and 0.05 Mrad, respectively. By irradiating them at each optimum dose, the practical storage-life of carp could be extended from one week to five at both $0^{\circ}\;and\;5^{\circ}C$ and that of rainbow trout from one week to 3-4 weeks at $0^{\circ}C$ and from 3 days to 14 days at $5^{\circ}C$. The carp meat suffered from extensive drip loss during the post-irradiation storage and it could be reduced effectively by dipping the samples into 10% polyphosphate solution prior to the radurization treatment. The rainbow trout was highly radiosensitive, while carp appeard to one of promising species to be radurization treated for the purpose of extending storage-life at refrigerated temperatures.

• Journal of Life Science
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• v.8 no.5
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• pp.582-588
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• 1998

The male reproductive system of Macrobrachium nipponense consists of a pair of lobulate testes enveloped within a mesenteric sheath extending the length of the carapace. The paired vasa deferentia originated from the mid-lateral region of each testis and extended to the genital pores at the base of the fifth walking legs. The vas deferens has four morphologically distinct regions, i.e., a short and slender proximal region, a long convoluted region, an elongate distal region and an ejaculatory duct that terminates at the genital pore. The sperm mass produced in the testes is surrounded by a basophilic matrix adjacent to the high columnar epithelium and an eosinophilic matrix adjacent to the simple columnar epithelium. The sperm cord is stored in the ejaculatory duct until it is ejaculated. Androgenic gland is found near the subterminal region of the ejaculatory duct between the muscles of the coxopodite of the last thoracic leg. The cell of the androgenic gland is about 6~8 $\mu$m in length, characterized by with extended chromatin in the large nucleus that stained weakly with hematoxylin and there is a large quantity of cytoplasm. The sperm of M. nipponense are typical of the palaemonid type, having a convex, cup shaped head and an elongated spike extending from the centre of the convex head. The spermatophore consisted of an eosinophilic matrix, a basophilic matrix and paired sperm masses which was surrounded by the basophilic matrix. It generally shows a bilaterally symmetrical structure.