• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.107-112
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• 2011

FFV(Flexible Fuel Vehicle) is the vehicle that can be used liberally from gasoline to E100(Ethanol 100%) for fuel. Recently, interest in the bio-fuel is increased by the environmental factors like exhaustion of the fossil fuel and ruduction of greenhouse gases. For the reason, adopting of FFV is activated in the world including North and South America. In general, bio-ethanol has highly corrosive substance in compare with gasoline. In the part of fuel system, corrosion can make a safety problem in case of fuel leakage and engine starting problem. So the fuel system of FFV have to be made of high corrosion-resistant materials. This study examined the effect of bio-ethanol on the durability properties according to component materials in FFV fuel pump motor and regulator using the High Temperature Fuel Circulation Test.

• Journal of Biosystems Engineering
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• v.3 no.2
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• pp.126-132
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• 1978

This study was carried out through the survey questionaries in order to get the information for proper operating technique of the two-wheel tractors which are widely used in the farm, and investigated various accidents which occurred during the operation of two-wheel tractors for farm works in 7 Provinces of Korea. The summarized results are as follows ; 1. Annual accident frequency of the two-wheel tractor was 2.07 times, and the average rate of accident was 0.72 times per hour. Its value was the largest in the pre-operations , and the smallest in the threshing operation. 2. The accident distribution according to each month was nearly propertional to the operating hours of the two-wheel tractor. More than 60 % of total accident was concentrated during the rice transplanting and harvesting season. 3. The careless accident was more than 50% of total accident , and inevitable accident about 18% . The rate of careless accident showed the highest in pre-operation such as engine starting, check, and adjustment, and belt change. 4. The serious wounded operator was 7.1 % to total wounded operator , and about 50 % of accident of casualties to operators occurred during haruling operations. 5. The amount of casualties to property was range of 1,000 to 10,000 won, and annual total amount per unit tractor could be estimated to be 10 , 000 won.

• Journal of Korea Game Society
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• v.16 no.3
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• pp.35-44
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• 2016

The progress of the game engine make us easier to develop a game product and it is possible for one man to make a game. This means that if you have ideas about game, you can make a game as you thought only if you know how to design a game. Because the game designing is not the field that may not be used like tools and could not buy like graphical data. This study, based on the practice, presented to the understanding and guidance for people who want to know about game designing such as no experienced person and starting new game design. These contributions are supported by a detailed exploration of common understandings of game design methods so that I expect to help designing or managing the project.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.34-39
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• 2014

A study is analyzed on the design factor of center-body diffuser and performed on conceptual design of center-body diffuser with computational fluid dynamic. The flow field of center-body diffuser is calculated using axisymmetric two-dimensional Navier-Stokes equation with $k-{\epsilon}$ turbulencemodel. The center-body diffuser is compared with second throat exhaust diffuser in terms of starting pressure, the degree of vacuum pressure and the design factors. The counter flow jet on cone-tip of the center-body is applied for thermal protection system in the center-body diffuser.

• International journal of advanced smart convergence
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• v.7 no.3
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• pp.73-78
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• 2018

This study focuses on presenting the IT program module provided by BKLS measure in order to solve the problem of capital cost due to information asymmetry of external investors and corporate executives. Barron at al(1998) set up a BKLS measure to guide the market by intermediate analysts. The BKLS measure was measured by using the changes in the analyst forecast dispersion and analyst mean forecast error squared. This study suggests a model of the algorithm that the BKLS measure can be provided to all investors immediately by IT program in order to deliver the meaningful value in the domestic capital market as measured. This is a method of generating and analyzing real-time or non-real-time prediction models by transferring the predicted estimates delivered to the Big Data Log Analysis System through the statistical DB to the statistical forecasting engine. Because BKLS measure is not carried out in a concrete method, it is practically very difficult to estimate the BKLS measure. It is expected that the BKLS measure of Barron at al(1998) introduced in this study and the model of IT module provided in real time will be the starting point for the follow-up study for the introduction and realization of IT technology in the future.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.237-240
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• 2005

As a part of the effort for improving the durability design based on a set of the deem-to-satisfy specifications, it is important and primary to quantitatively identify the environmental impact to a target reinforced concrete structure. In this work, an effort is made to quantitatively calculate the environmental affecting factor with using a fuzzy inference that it indicates the severity of environmental impact to the exposed reinforced concrete structure or member. This system is composed of input region, output region and rule base. For developing the fuzzy inference system surface chloride concentration{chloride), cyclic degree of wet and dry(CWD), relative humidity(RH) and temperature (TEMP) were selected as the input parameter to environmental affecting factor(EAF) of output parameter. The Rules in inference engine are generated from the engineering knowledge and intuition based on some international code of practises as well as various researcher's experimental data. The devised fuzzy inference system was verified comparing the inferred value with the investigation data, and proved to be validated. Thus it is anticipated that this system for quantifying EAF is certain to be considered into the starting point to develop the performance-based durability design considering the service life of structure.

• International Journal of Automotive Technology
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• v.7 no.3
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• pp.277-282
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• 2006

With the aim of achieving half the regulated value of EURO-3 Emission Regulations, an ultra low emission motorcycle has been developed based on a motorcycle with an 1800 $cm^3$, horizontal opposed 6-cylinder engine. For the fuel supply system, an electronically controlled fuel injection system was applied. For the emission purification system, three-way catalysts, a feedback control system with a LAF(Linear Air-Fuel ratio) sensor, and a secondary air induction system were applied. To reduce CO and HC emissions during cold starting, an early catalyst activation method combining RACV(Rotary Air Control Valve) and retarded ignition timing was applied. After the catalyst activation, air-fuel ratio was controlled to maximize the purification ratio of the catalyst according to vehicle speed. For the air-fuel ratio control system, the LAF sensor was used. Furthermore, fine adjustment by the LAF feedback control reduced torque fluctuation due to the air-fuel ratio change. As a result, smooth ride feeling was maintained. Owing to these technologies, half the regulated value of EURO-3 has been achieved without any negative impact to the large-scaled motorcycles' drivability. This paper presents the developed ultra low emission technologies including the control method using an LAF sensor.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.331-334
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• 2011

The performance of ramjet engine is closely associated with a supersonic intake. In this study, experiments and computational simulations were conducted to observe the internal flow characteristics of the supersonic intake. The supersonic intake which have self-starting characteristics was designed and manufactured. The flow characteristics was analyzed from the experimental results using the supersonic wind tunnel testing and computational results using RANS equation and Menter's SST turbulence model. The detailed visualization results were suggested for the pseudo-shock wave of stable operations and for the inlet buzz phenomenon of unstable operations.

• Asia Pacific Journal of Business Review
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• v.3 no.2
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• pp.43-66
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• 2019

Home-based business (HBB) is one of the fastest growing form of business start-ups where the business is conducted from home. In develop economies, the HBB industry is an engine for economic growth that has proven its viability through significant contribution to the national GDP. In view of its importance, the Saudi Ministry of Commerce and Industry encourage local women to start and develop their own HBB as it gives them the flexibility while still contributing to the national economy. Although various initiatives have been taken place, little information is available about Saudi HBB. This study therefore aims to determine the factors that contribute to the growth as well as the challenges of female HBB in Saudi Arabia. The study was based on qualitative approach which adopted an in-depth interview with eleven Saudi females who run HBB. The findings revealed that HBB contributing factors comprised of access to funding, sufficiency of savings and the influence of the intrinsic and extrinsic motivation in starting the business. Meanwhile, the obstacles are government regulations and policies, culture, and home design. The study recommendations include improving banks and service institution policy and procedures to enable HBB to have access to funding and services and to develop legal policies to protect the right of the HBB operator and customers. Finally, the study also suggests future research on managerial factors that can contribute to HBB female success, the stress coping mechanism of HBB and the factors contributing to the difference between HBB in growth strategies.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.981-984
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• 2011

A high-resolution numerical study is carried out to investigate the transient process of the combustion and the shock-train developments in an ethylene-fueled direct-connect dual-mode scramjet combustor. Following the fuel injection, air-throttling is applied at the expansion part of the combustor to provide mass addition to block the flow to subsonic speed. The ignition occurs several ms later when the fuel and air are mixed sufficiently. The pressure build up by the combustion leads to the shock train formation in the isolator section that advances to the exit of the intake nozzle. Then, the air-throttling is deactivated and the exhaust process begins and the situation before the air-throttling is restored. Present simulation shows the detailed processes in the dual-mode scramjet combustor for better understanding of the operation regimes and characteristics.