• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.655-662
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• 2003

Slope stability is an important issue ill civil engineering works or in open pit mines where both economy and efficiency is required. These are the long-term stability problems which depend on the change of physical properties under a certain weather condition. These can also result in progress of weathering which can change mechanical or hydro-geological properties of rock mass considerably. In this study, weathering in nature was simulated by freeze-thaw test and Soxhlet test which represent mechanical and chemical weathering respectively. Measured were elastic wave velocities, absorption rate, volume change. Uniaxial compression strengths before and after the weathering tests were also measured. The change in weight and volume of the specimens were not clearly related to the weathering process, but P, S wave velocities were clearly decreased as weathering progresses. For some class of rocks, P-wave velocity was increased probably because of the saturation due to improved connectivity of the pre-existing pores. Based on the test results, stability of the slopes were analyzed using FLAC$\^$2D/. Due to the reduced strength parameters, the factors of safety were decreased for the selected sites.

• 한국군사과학기술학회지
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• 제16권2호
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• pp.225-232
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• 2013

In this paper, the study was conducted on the subject of the hybrid electric vehicles used by the military, and optimized the propulsion system for fuel economy considering energy supply to the mission equipments. For the analysis of the vehicles, a method based on the geometry and some assumptions was applied with basic vehicle dynamics. The sources of energy supply in the military hybrid electric vehicles are an engine, a battery and an ultra-capacitor. The optimal operation point among an engine, a battery and an ultra-capacitor can be found by minimizing energy consumption of driving power train and mission equipments. In the study, it was possible to find the optimal propulsion system by comparing fuel efficiency of the vehicles during the driving cycle.

• 품질경영학회지
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• 제40권4호
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• pp.497-512
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• 2012

Purpose: Most major countries have their own set of qualifications called national quality awards to measure the quality of companies and organizations. This study analyzes 3 different national quality awards and compare with the result from Korean quality awards conducted by Ministry of knowledge and Economy and Korea institute for advancement of technology. Methods: We tested 17 technoparks out of 18 technoparks in Korea and see how different the results can be depends on the value weights. We closely looked at each qualifications and tables of different countries' awards and compared with one used in Korea. Finally we proposed some suggestions to use not only domestic model but also international ones to be objective and add efficiency to organizations. Results: Depend on similarity of qualifications and weights, there were countries with different results and these caused score and ranking changes. Nevertheless, there was a comparison that did not make any changes on both score and ranking. Conclusion: We recognized the limitation that a standardized quality variation cannot be enough sources to test and analyze technoparks with different size and criteria. Integrating global standards and flow would be the first step to help grow technoparks and organizations placed in Korea in days to come.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.151.1-151.1
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• 2010

Natural gas hydrates (NGH) provide 170 gas volumes per unit volume of the medium and are easier to make with moderate pressure and temperature (40 bar at 3 C). Once they form, their preservation temperature is 20 C at 1 bar, which is much milder than the LNG preservation. In case of using the NGH, The small and medium sized gas well has advantages for development because of NGH's these characteristics. According to the cost evaluation report of Gudmundsson in Norway and the research of MES in Japan, the gas well that uses the NGH has a cost saving effect about 10~20% compared LNG. The effect depends on distance and production. However, cost saving and efficiency of liquefaction process is increased by the development of LNG liquefaction technology. Therefore, these factors have to be reflected in economic analysis. The purpose of this research is to compare the cost of Gas Supply Chain according to the transport type, distance and gas reserves. Especially, we consider not only the cost of facility but also the total cost (production cost, transport cost, etc).

• Asian-Australasian Journal of Animal Sciences
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• 제24권11호
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• pp.1629-1636
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• 2011

Global pork markets are becoming more competitive, riding the wind of the bilateral free trade agreement. China is the world's largest pork producer with nearly 50% of the world's total production. China's fast growing economy has provided its people with higher purchasing power, resulting in a rapid expansion of the Chinese swine industry over the past decades. Worldwide, China consumes the greatest amount of pork and it is believed that this trend will continue. Japan is the world's largest pork importing country, even though it also produces a lot of pork. The Japanese swine industry encounters weighty obstacles in production costs and environmental limitations which result in reduced domestic supply and creates the situation in which Japan has to import a significant amount of pork for their consumption. South Korea is also a large buyer of pork, with a status greatly influenced by the struggle that the country has faced with Foot and Mouth Disease (FMD) which occurred in 2000, 2002 and 2010. High production costs, low production efficiency, and forced culling following the FMD outbreak resulted in the loss of many hog farming households in the country, reducing supply of domestic pork in the face of continued demand. Overall, pork production in these economically important countries can greatly impact the industry globally. The goal of this review paper is to describe pork production in China, Japan, and South Korea and discuss these countries' role in global pork export markets.

• 한국건설순환자원학회논문집
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• 제2권4호
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• pp.297-306
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• 2014

Recently nano-materials are gaining more importance in the construction industry due to its enhanced energy efficiency, durability, economy, and sustainability. Nano-silica addition to cement based materials can control the degradation of the fundamental calcium-silicate-hydrate reaction of concrete caused by calcium leaching in water as well as block water penetration and therefore lead to improvements in durability. In this paper, the influence of synthesized nano silica from locally available rice husk on the mechanical properties and corrosion resistant properties of OPC (Ordinary Portland Cement) has been studied by conducting various experimental investigations. Micro structural properties have been assessed by conducting Scanning Electron Microscopy, Thermo gravimetry and Differential Thermal Analysis, X-Ray Diffraction analysis, and FTIR studies. The experimental results revealed that NS reacted with calcium hydroxide crystals in the cement paste and produces Calcium Silicate Hydrate gel which enhanced the strength and acts as a filler which filled the nano pores present in concrete. Hence the strength and corrosion resistant properties were enhanced than the control.

• 대한산업공학회지
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• 제40권6호
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• pp.555-567
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• 2014

Over 40 years, the domestic manufacturing industry of Korea played the vital role in creating national wealth, employment and innovation in its economy. In 2011, industrial products made up 99.7 percent of exports, and formed 31.2 percent of GDP. Given those facts, the research of manufacturing systems engineering for higher manufacturing efficiency and its industrial applications have been essential for Korea's economic growth. In this paper, for celebrating the 40th anniversary of the foundation of Korea institute of industrial engineers (KIIE), the research results and its industrial applications of KIIE are reviewed and summarized in the area of manufacturing systems engineering over past 40 years. Directions of future manufacturing system and the role of industrial engineers for our continuous economic growth are also mentioned.

• 대한기계학회논문집
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• 제18권3호
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• pp.751-767
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• 1994

Recent developments of S.I. engine, aiming to higher power, better fuel economy, lower air pollution and better driveability, have much focused on the importance of the role of computer simulation in engine research and development. In this point of view, improving engine performance requires finding some means to improve volumetric efficiency. Up to now there have been several attempts to optimize the intake and exhaust system of internal system of S.I. engine by computer simulation. There appear to be few studies available, however, of such simulation & experimental studies applied to the optimization of exhaust manifold configuration. In this study, gas exchange & power process of 4 cylinder S.I. Engine was studies numerically & experimentally, and governing equation of a one-dimensional unsteady compressible flow and combustion process were respectively solved by a characteristics method and 2-zone model. The aim of this study is to predict and investigate the influence of pressure wave interaction at the exhaust systems on engine performance with widely differing exhaust manifold configuration.

• 한국자동차공학회논문집
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• 제20권3호
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• pp.98-105
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• 2012

Recently, most of the countries started to regulate the emission of vehicle because of the global warming. The engine scooter is also one of the factor which cause the pollution. The hybrid system of a vehicle has many advantages such as fuel saving and emission reduction. The purpose of this study is to choose optimal size of engine, motor and battery for hybrid scooter system using Dynamic programming. The dynamic programming is an effective method to find an optimal solution for the complicated nonlinear system, which contains various constraints of control variables. The power source size of hybrid scooter was chosen through the backward simulator using dynamic programming. From the analysis, we choose the optimal size of each power source. To verify the optimal size of the power source, the Forward simulation was carried out. As a result, the fuel efficiency of hybrid scooter has significantly increased in comparison with that of engine scooter.

• 한국산업정보학회논문지
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• 제4권4호
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• pp.15-24
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• 1999

급변하는 시장 경제체제에서 많은 기업들은 경쟁력 유지를 위하여 ERP시스템을 도입 구축하고 있다. 그러나 이들이 구축하여 활용하고 있는 ERP 정보는 그 활용범위가 기업 내에 국한되어 효율성이 떨어진다. 본 논문에서는 클라이언트/서버 환경에서 개발 운용되고 있는 ERP 시스템 구성과 인터넷 적용을 위한 구성요소 및 플랫폼에 대해 비교하고 인터넷환경에서 기업의 판매정보 및 고객정보, 생산능력정보, 재무구조 등을 활용함으로써 영업력 강화와 고객에 대한 신뢰도 향상의 새로운 부가가치 창출을 위한 인터넷활용의 전략적 방안을 제안하였다.