• Journal of KIISE:Computer Systems and Theory
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• v.30 no.12
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• pp.724-735
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• 2003

In recent high-performance superscalar processors, the result value of an instruction is predicted to improve instruction-level parallelism by breaking data dependencies. Using those predicted values, instructions are speculatively executed and substantial performance can be gained. It, however, requires additional power consumption due to the frequent access and update of the value prediction table. In this paper, first, the trade-off between the performance improvement and the increased power consumption for value prediction is measured and analyzed. And, in order to reduce additional power consumption without performance loss, the technique of controlling speculative execution with confidence counter and predicting useful instructions is developed. Also, in order to prove the validity, a tool is developed that can simulate processor behavior at cycle-level and measure total energy consumption and power consumption per cycle.

• The KIPS Transactions:PartD
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• v.17D no.5
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• pp.327-336
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• 2010

This paper proposed software equation that is relation with effort and duration based on function point (FP) software size. Existent software equation based on lines of code (LOC). LOC sees big difference according to development language and there are a lot of difficulties in software size estimation. First, considered method that change LOC to FP. But, this method is not decided definitely conversion ratio between LOC and FP by development language. Also, failed though the conversion ratio motives software formula because was not presented about specification development language. Therefore, we derived software formula directly to large project data that was developed by FP. Firstly, datas that reasonable development period is set among development projects. Secondly, FP through regression analysis about this data and effort, motived relation with FP and duration. Finally, software equation was derived from these relation. Proposed model solves application problems that LOC-based model has and has advantage that application is possible easily in business.

• Journal of Distribution Science
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• v.14 no.10
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• pp.147-152
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• 2016

Purpose - High quality films are affected by both the production stage and various variables such as the size of the movie investment and marketing that changes consumers' perceptions. Consumer preferences should be recognized first to ensure that the movie is successful. If a film is produced without pre-investigation and analysis of consumer demand and taste, the probability of success will be low. This study investigates the balance of production costs, marketing costs, and profits using game theory, suggesting an optimization strategy using the simplex method of linear programming. Research design, data, and methodology - Before the release of the movie, initial demand is assumed to be driven largely by marketing costs. In the next phase, demand is assumed to be driven purely by a movie's production cost and quality, which might also further determine consumer demand. Thus, it is essential to determine how to distribute pure production costs and other costs (marketing) in a limited movie production budget. Moreover, it should be taken into account how to optimally distribute under the assumption that the audience and production company's input resources are limited. This research simplifies the assumptions for large-scale and relatively small-scale movie investments and examines how movie distribution participant profits differ when each cost is invested differently. Results - When first movers or market leaders have to choose both quality and marketing, it has been proven that pursuing a strategy choosing only one is more likely than choosing both. In this situation, market leaders should maximize marketing costs under the premise that market leaders will not lag their quality behind the quality of second movers. Additionally, focusing on movie marketing that produces a quick effect while ceding creative activity to increase movie quality is a natural outcome in the movie distribution environment since a cooperative strategy between market competitors is not feasible. Conclusions - Government film development policy should ignore quality competition between movie production companies and focus on preventing marketing competition. If movie production companies focus on movie production quality improvement then a creative competition would ensue.

• Journal of the Korean Electrochemical Society
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• v.9 no.4
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• pp.170-177
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• 2006

Optimum design of flow channel in the separation plate of Proton Exchange Membrane Fuel Cell is very prerequisite to reduce concentration over potential at high current region and remove the water generated in cathode effectively. In this paper, fully 3 dimensional computational model which solves anode and cathode flow fields simultaneously is developed in order to compare the performance of fuel cell with parallel and interdigitated flow channels. Oxygen and water concentration and pressure drop are calculated and i-V performance characteristics are compared between flows with two flow channels. Results show that performance of fuel cell with interdigitated flow channel is hi민or than that with parallel flow channel at high current region because hydrogen and oxygen in interdigitated flow channel are transported to catalyst layer effectively due to strong convective transport through gas diffusion layer but pressure drop is larger than that in parallel flow channel. Therefore Trade-off between power gain and pressure loss should be considered in design of fuel cell with interdigitated flow channel.

• Analytical Science and Technology
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• v.8 no.1
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• pp.69-77
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• 1995

The instrumentation and operating characteristics of a gas-jet assisted radio frequency glow discharge atomic absorption spectrometry(RF-GDAAS) are studied. The roles of discharge power, pressure as well as gas flow rate on the sample loss rate and absorbance are described in this paper. Results show that the optimum discharge conditions depend on pressure and discharge power as well as on the gas flow rate. The gas flow rate plays as an important parameter in RF-GDAAS. Absorbance increases as the gas flow rate increase up to 600ml/min., and the optimum absorbance is obtained at the pressure of 3 mbar. The absorbance increases when the discharge power increases as expected, however, the instability of the system due to the heat might be the trade off factor. The linear calibration curves of Ni and Cr in stainless steel(BAS 461-468) and brass (KSS 1121-1126) are obtained with RF-GDAAS.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.183-193
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• 2007

Traditionally, a congestion charge based on first-best congestion pricing theory, namely, the theory of marginal cost pricing theory, is equal to the difference between marginal social cost and marginal private cost. It is charged on each link so as to derive a user equilibrium flow pattern to a system optimal one. Based on this theory this paper investigates on the characteristics of first-best congestion pricing of multiple user class on road with variable demand, and presents two methods for analysis of social and spatial equity. For these purposes, we study on the characteristics of first-best congestion pricing derived from system optimal in time and in monetary unit, and analyze equity from this congestion pricing with an example network.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.3
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• pp.18-28
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• 2007

Three diesel engines were fueled with BDF 20, a blend of 80% diesel fuel and 20% biodiesel fuel by volume, and run in excess of 200 h to evaluate their combustion characteristics and durability. The engines used for this study were a 4-cylinder 2476-cc displacement IDI diesel engine(Engine 1), a 4-cylinder l732-cc displacement IDI diesel engine(Engine 2), and a single cylinder 673-cc displacement DI diesel engine(Engine 3). Engine dynamometer testing was performed on each engine at regularly scheduled intervals to monitor the performance and exhaust emissions, which were sampled at 1h intervals for analysis, The peak combustion pressure with BDF 20 increased in Engines 1 and 3 over that measured when burning pure diesel fuel, but that in Engine 2 remained constant. Combustion parameters, such as the maximum combustion pressure and corresponding crank angle, did not change over the long-term dynamometer testing. The BSFC with BDF 20 in Engine 1 was less than that measured with pure diesel fuel. The amount of smoke produced with BDF 20 was less for all engines ; the greatest reduction was observed for Engine 3. The NOx emissions were lower in the IDI engines than the DI engine. The traditional trade-off between smoke and NOx emissions was maintained for BDF 20 fuel for Engines 1 and 3. There was not a big difference in the $CO_2\;and\;O_2$ emissions for BDF 20, as compared to pure diesel fuel, but more $CO_2$ was exhausted by Engine 1 than by Engines 2 or 3 and less $O_2$ was exhausted by Engine 1 than by Engines 2 or 3. The engine parts remained clean, except for some carbon attached to the area surrounding the nozzle hole of the DI diesel engine.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.4
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• pp.234-244
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• 2014

Recently it has been focused that the automobile engine has developed in a strong upward tendency for the use of the high viscosity and poorer quality fuels in achieving the high performance, fuel economy, and emission reduction. Therefore it is not easy to solve the problems between low specific fuel consumption and exhaust emission control at motor cars. In this study, it is designed and used the engine test bed which is installed with turbocharger and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters, and they were engine speeds(rpm), injection timing(bTDC), and engine load(%). From the result of an experimental analysis, peak cylinder pressure and the rate of pressure rise were increased, and the location of it was closer toward top dead center according to the increasing of engine speed and load, and with advancing injection timing. The combustion characteristics are effected by fuel injection timing due to be enhanced the mass burned fraction. Using the engine dynamometer for analyzing the engine performance, the engine torque and power have been enhanced according to advancing the fuel injection timing. In analyzing of exhaust emission, there has been a trade-off between PM and NOx with increasing of engine speed and load, and with advanced injection timing. The experimental data are shown that the formation of NOx has increased and PM, vice versa.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.8
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• pp.809-815
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• 2003

It is very important to get very high switching speed as well as low phase noise of frequency synthesizer in the OFDM/FH communication system. In this paper we compare the phase noises and switching speeds of the conventional PLL and digital hybrid PLL(DH-PLL) frequency synthesizer, also, we investigate the effect of phase noise on the performance of OFDM/FH communication system. DH-PLL has high switching speed property at the cost of circuit complexity and more power consumption. Unlike the conventional PLL in which the phase noise and switching speed have the trade off relationship in respect of loop filter bandwidth, DH-PLL frequency synthesizer can perform fast switching speed and low phase noise simultaneously. Under the condition of same hopping speed requirement, DH-PLL can achieve faster switching speed and lower SNR penalty compared with conventional PLL in the OFDM/FH communication system.

• Korean Journal of Agricultural Science
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• v.25 no.2
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• pp.293-309
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• 1998

This study is aimed at identifying the decision making criteria as B/C ratio, IRR and NPV based on the expected benefits and costs of the land utilization and promotion projects which have implemented to improve agricultural structure under WTO system. To carry out the objectives of the study, Sinseok project area located at Dangjin district, Chungnam province was selected. Sinseok project area has 306.2 ha of paddy area with 172 farm households. The project area will be operated by the 33 specialized farm households after completion of the project which will have 20 years of economic life. After completion of the project, farm size will be increased from 1.8ha to 9.3ha. Land intensity of the project area will be increased by 10%. Increase of land productivity and cost saving due to the labor saving technology as farm mechanization will be expected. According to the survey results, the annual amount of production cost savings per farm was estimated 3.884million won and increased total farm income was expected about 43.8million won per year. The total expexted project benefits was expected 174million won per year. The project costs to promote land utilization and structural change consisted of handling charges, and direct payment for land movility. The decision making criteria representing economic feasibility of the project such as B/C ratio, NPV and IRR were estimated 2.49, 483million won and 30% respectively when the cut-off rate was taken into account 10%. In conclusion, the land utilization and promotion project proppeled by the Korean Government under the agricultural land law is considered economically feasible from the view points of expected project benefits and costs. Accordingly the project have to be implemented more strongly under the G't financial support considering WTO and UR negociation which were aimed at achieving the free trade and improvement of international competitiveness of farm products.