• Title/Summary/Keyword: PROPULSION

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A Study on the Finite Element Analysis and Management Criteria by Applying UPRS Method in the Subway Station (기존 지하철정거장 비개착공법 적용시 유한요소 해석과 관리기준에 관한 연구)

  • Cho, Byeong Joon
    • Journal of Korean Society of Disaster and Security
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    • v.12 no.4
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    • pp.43-52
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    • 2019
  • To analyze the influence on the stability, resulting from application of upgrade pipe roof structure (UPRS) method to the structure existed under subway Station, physical properties of a ground, elasticity and elasto-plastic theories, including displacement analysis of finite elements, stress analysis of finite elements, displacement caused by steel pipe propulsion and internal excavation, and stress change in a steel pipe, were introduced. Then, the influence on structural stability when applying the UPRS method was compared and reviewed based on the construction management standard of the Ministry Land, Infrastructure and Transport and foreign sources, using numerical analysis with a model which assumes that each microelement divided into a structurally stable point consists of the connection of finite points. As a result of the finite element analysis, 7.21 mm maximum displacement, 1/3,950 angular displacement, 70.28 MPa bending compressive stress of steel pipe structure constructed with UPRS (non-excavation) method and 477.38 MPa maximum shear strength were within their allowable standards (25.00 mm, 1/500, 210.00 MPa and 120.00 MPa, respectively), and therefore, the results showed that the design and construction are stable.

General Pharmacology of G009, a Polysaccharide Isolated from Ganoderma lucidum IY 009

  • Kim, Su-Ung;Lee, Seung-Yong;Lee, Seung-Mok;Jeong, Hoon;Hyun, Ik-Sang;Lee, June-Woo;Han, Man-Deuk;Lee, Eun-Bang;Cheon, Seon-Ah;Kim, Sang-Mee;Kim, Kyung-Ran
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.106-106
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    • 1995
  • A polysaccharide, G009, isolated from Ganoderma lucidum IY009 subjected to investigating on general pharmacology. This material at the large oral doses of 1000 and 2000mg/kg in mice did neither exhibit any abnormal behaviors nor effects on central nervous system. It also had no influences on hexobarbital-induced sleeping time, rotarod test and spontaneous activity test at each oral dose of 1000mg/kg in mice. No effects on the body temperature and on acetic acid induced writhing syndrome in mice were observed with its oral administration at 1000mg/kg, and the convulsions induced by strychnine and pentetrazole were not inhibited at its oral doses of 1000mg/kg in mice. The solution of G009 as given intravenously at the doses of 30 and 60mg/kg in rabbit had no influences on blood pressure and respiration rates and depth. In isolated organs of rat uterus and fundus muscles and guinea-pig ileum and trachea, it did not show any contraction or relaxation at the concentration of 2$\times$10$^{-3}$g/ml, and the contractive actions produced by oxytocin, acetylcholine, serotonin and histamine did not inhibited by the same doses. This material showed no effect on intestinal propulsion test in mice and gastric secretion in rats at the oral doses of 1000mg/kg. However, it is interesting that the material exhibited potent inhibition of acidified aspirin induced gastric damage at the doses of 500 and 1000mg/kg in rats.

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A Comparative Study of Korea and Japan Relating to the Welfare Business Operation of Pension Accumulation (연금적립금의 복지사업 운용에 관한 한.일 비교연구)

  • Chung, Ki-Ryong
    • Korean Journal of Social Welfare
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    • v.35
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    • pp.345-374
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    • 1998
  • The purpose of this study is to contribute the improvement of national welfare by presenting of pension welfare business of Korea and Japan. The reason why I take the management of Japan's pension accumulation as the object of comparative study is that the history of pension system of Japan is relatively longer than that of Korea. First of all, National Pension Fund comes into use for public sector, financial sector, and welfare sector, The scale of pension management for welfare sector is 50 small. Therefore, the study for welfare business investment reflecting the intentions of pension entries and pensioners is needs of times. This study defines the concept of welfare investment business and prospects welfare investment business of the future on the basis of Japanese experiences, and then suggests the direction of efficient propulsion of welfare investment business to the reasonable decision-makers. Especially this study redefine the concept of welfare investment business on the basis of pension entry's social benefits which are composed of pension entry's gains and pensioner's gain. Of course, welfare investment business has to be presupposed the stability of pension system and the continuous contribution to national economy. Thus, in order to efficiently perform welfare business, the policy-making for national welfare improvement has to be established after the good of business is set up like the results of this study.

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Alternatives for Establishing Green Logistics System in Ulsan Port (울산항의 녹색물류체계 구축 방안)

  • Jo, Jin-Haeng
    • Journal of Korea Port Economic Association
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    • v.35 no.4
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    • pp.187-206
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    • 2019
  • After reviewing the concept and previous studies related to green ports, this study analyzes the implications of green port policy of advanced ports in foreign countries and analyzes problems in terms of environmentally-friendly green port policy for Ulsan port, and to present sustainable green logistics establishment measures. The literature survey and Benchmarking methods are adopted as research methodology and the results are as follows. First, the pan-government climate change response management system, legislation of relevant laws, implementation of fiscal support policies, and roadmaps should be established. Second, the foundation for eco-friendly green growth should be established through the discovery of business models in conjunction with leading industries in the Southeastern Metropolitan Economic Area. Third, the Ulsan Port Greenport, such as AMP, in-port LNG propulsion ship, and ESI vessel incentive, should be built. Fourth, a low-carbon, high-efficiency sea-shuttle service shall be established through the introduction of the sea-shuttle service along the sea route. Fifth, energy self-reliant ports, including all institutions in the metropolitan Ulsan port area that have exceeded the level of Ulsan port Authority, should be built. Finally, water-type ports need to be built through the creation of coastal forests, the purification of marine water quality, and the introduction of colors to port.

A Study on the Configuration of Two-Dimensional Waterjet Inlet (이차원 물분사 추진장치 입구면 형상에 관한 연구)

  • J.M. Lew;S.K. Hong;Y.G. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.2
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    • pp.9-21
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    • 1999
  • The waterjet is very widely used today in propulsion system of high speed vessel but manufacturer is limited because of an efficiency and a difficulty of a manufacture on the inlet configuration of the waterjet. The importancy in designing the inlet configuration of the waterjet lies on the minimization of the cavitation which is largely affecting the efficiency. In this paper, the configuration analysis is carried out to find a optimum shape which is minimizing the cavitation using a two dimensional potential-based panel method with an inlet configuration of a flush type. Also, it is developed a direct design method finding an inlet configuration by a given pressure distributions. The numerically obtained optimum shape using this configuration analysis method show a good agreement compared to the Kashiwadani's results. It is carried out a direct design method over a lip and a ramp of an inlet configuration wish pressure distributions obtained a result of the configuration analysis and the results show a good agreement compared to original configuration.

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Determination of Interaction Parameter χ of the 1,2,3-Triazole Crosslinked Polymer (1,2,3-트리아졸 폴리머의 상호계수 χ의 결정)

  • Lee, Dong-Hoon;Lee, Sookyeong;Kim, Kyoung Tae;Paik, Hyun-Jong;Jeon, Heung Bae;Min, Byoung Sun;Kim, Wonho
    • Elastomers and Composites
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    • v.48 no.2
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    • pp.148-155
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    • 2013
  • The crosslinking density of polymer can be quantitatively calculated by the Flory-Rehner equation using the swelling experimental data and the lattice constant ${\beta}_1$ of interaction parameter (${\chi}$) in this equation should be chosen have used cautiously. This ${\beta}_1$ is the experimental data by rule of thumb, and researchers have used little different values respectively. Generally, the average molecular weight between crosslink points $M_c$ in the Flory-Rehner equation and the Mooney-Rivlin equation have the same value, and ${\beta}_1$ can be calculated when the $M_c$ in the Flory-Rehner equation is given. Therefore, in this research, firstly we calculated the $M_c$ using the selected ${\beta}_1$ (=0.34) and the swelling experimental data of 1,2,3-triazole polymer from the Flory-Rehner equation, secondly the $M_c$ from the Mooney-Rivlin equation is calculated by the tensile experimental data, and finally two $M_c$ were compared. As a result, two $M_c$ values were almost the same, and it was proved that the ${\beta}_1$ (=0.34) was selected properly.

A Study on the Improvement of Multi-Agency R&D Program for Strategic Budget Allocation and Enhance Effectiveness (전략적 예산배분 및 실효성 강화를 위한 다부처R&D사업의 개선방안에 관한 연구)

  • Moon, Kwansik;Kim, Eun Jeong
    • Journal of Digital Convergence
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    • v.14 no.6
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    • pp.9-19
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    • 2016
  • Since continuous expand in governmental R&D investments and growth number of research institutions, model of multi-agency program has been planned and pushed ahead to settle the inefficiency of investment by the scattered and competitive R&D Programs. However, it was often pointed out that new model's effect has been fall because the institutional inertia of cooperative system between agencies. In this study, we analyze the current state of multi-agency program and suggest the optimal R&D governance model to improve a better direction. Afterward, several problems were turned up and that allocation and execution of the R&D budget separately, less coordination and cooperation among agencies, and absence of typical evaluation system of multi-agency program. Therefore, we suggest some of improvements by analyzing each steps.

Study on Development Method for Galileo/SAR Ground System in Korea (국내의 갈릴레오 탐색구조 지상시스템 개발 방안에 관한 연구)

  • Ju, In-Won;Lee, Sang-Uk;Kim, Jae-Hun
    • Journal of Satellite, Information and Communications
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    • v.2 no.1
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    • pp.35-40
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    • 2007
  • COSPAS-SARSAT is the search and rescue system for providing a distress alarm and a position identification using an international satellite and ground facilities. Aviators, mariners and land users worldwide are equipped with COSPAS-SARSAT distress beacons, which could help save their in emergency situations anywhere in the world. As the existing COSPAS-SARSAT system is generally operated by LEO(Low-altitude Earth Orbit) Satellite System, the time from the distress beacon to the rescue is more than 1 hour with average and the accuracy of the distress location is about 5 Km. Therefore, in order to overcome this problem, the development for the next generation SAR(search and rescue) system which uses the MEO(middle-altitude Earth Orbit) satellites is going on the Galileo project. EU is developing this project for the full operation capability in 2011, and this project will have SAR payloads and support to the Search and Rescue service-herein called SAR/Galileo. SAR/Galileo will have the performance of a few meter accuracy, within 10 minutes to rescue from reception of distress messages, and Return Link Service(from the SAR operator to the distress emitting beacon), thereby facilitating more efficient rescue operations and helping to reduce the rate of false alerts. As the disaster is larger every year, the ground station, MEOLUT for next generation ASR/Galileo is urgently needed for the lifesaving for the larger disaster, the research for beacon and the ground station such as MEOLUT for introducing the next generation SAR/Galileo in Korea is very timely and is important. This paper presents the procedures and the strategies for the participation, the area to develop reasonably, and the propulsion organization for developing the SAR/Galileo ground system in Korea.

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Quasi-Static Equilibrium of a Propeller Shaft in a Hydrodynamic Oil-Lubricated Stern Tube Bearing (윤활유(潤滑油) 선미관(船尾管) 베어링 축계(軸系)의 준정적(準靜的) 평형상태(平衡狀態)에 관한 연구(硏究))

  • S.Y.,Ahn;S.S.,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.26 no.3
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    • pp.51-61
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    • 1989
  • Recently, the growth in the propulsion power and propeller size of typical energy saving ships has resulted in severe damages of the oil-lubricated stern tube bearing. Consequently, a more rational analytical method for the design of the shafting system is required. In this paper an analytical method applicable to the design of the oil-lubricated stern tube bearing and shafting system is presented. The method consists of the finite element analysis of the shafting system and the oil film hydrodynamics. The shafting system is modeled as a three-dimensional problem using beam elements taking account for the steady components of thrust, lateral forces and moments of the propeller as well as the elastic foundation effects. The oil film hydrodynamics is modeled as a two-dimensional problem. Equal and retangular elements employing hourglass control method are used for the construction of the oil film fluidity matrix. To search the quasi-static equilibrium position between the propeller shaft and the oil film, an optimization technique is employed. Some numerical results based on the proposed method are compared with some measured and numerical data available. They show acceptable agreements with the data.

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Study on the Calculation of Towing Force for LNG Bunkering Barge (LNG 벙커링 바지의 예인력 계산에 관한 연구)

  • Oh, Seung-Hoon;Jung, Jae-Hwan;Hwang, Sung-Chul;Jung, Hyun-Woo;Cho, Seok-Kyu;Jung, Dong-Ho
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.11a
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    • pp.158-161
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    • 2018
  • In this paper, the towing force is calculated for the LNG bunker barge. LNG bunkering barge is being developed as an infrastructure for the bunkering of LNG(Liquefied Natural Gas), an eco-friendly energy source. In the case of the LNG bunker barge, a self-propulsion is considered through retrofit from an operating point. Therefore, the LNG bunker barge is similar to the shape of the ship as compared to a towed barge, so a rule of the towed barge overestimates the towing force. In order to improve accuracy, the calm water resistance is calculated according to the ITTC 1978 method considering the wave resistance by the Rankine source method. The added resistance in waves is calculated using the modified radiated energy method considering the shortwave correction method of NMRI. The performance of the towing resistances through the calm water resistance and the added resistance in waves was compared with rules of the towed barge.

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