• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.803-811
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• 2014

The moment when Electrical Vehicle (EV) starts charging or discharging is one of the most important parameters in estimating the impact of EV load on the grid. In this paper, a decision-making problem of determining the start time of charging and discharging during allowed period is proposed and studied under the uncertainty of real-time price. Prospect theory is utilized in the decision-making problem of this paper for it describes a kind of decision making behaviors under uncertainty. The case study uses the parameters of Springo SGM7001EV and adopts the historical realtime locational marginal pricing (LMP) data of PJM market for scenario reduction. Prospect values are calculated for every possible start time in the allowed charging or discharging period. By comparing the calculated prospect values, the optimal decisions are obtained accordingly and the results are compared with those based on Expected Utility Theory. Results show that with different initial State-of-Charge ($SoC_0$) and different reference points, the optimal start time of charging can be the one between 12 a.m. to 3 a.m. and optimal discharging starts at 2 p.m. or 3p.m. Moreover, the decision results of Prospect Theory may differ from that of the Expected Utility Theory with the reference points changing.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1063-1067
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• 1991

In this paper, we present a supervision and coordination level monitoring the adaptive controller and taking appropriate ,actions if malfunctions are detected. Supervision and coordination level are consist of start-up part and run-time part. The start-up part involves tasks for the configuration and the implementation of controllers, and the run-time part involves tasks for the supervision and coordination of the controllers in closed-loop operation. Also, we show how a supervision level and a coordination level can be designed and what basic elements should be included. Finally, we show the robustness of this scheme by experimental results for task model.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.299-302
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• 1996

The purpose of this study is developing scheduling logic and program for machining scheduling of automobile part production line with unbalanced processing time. Three rules are developed to minimize slack and effect on other job. Fourth rule is suggested which considered weighted sum of three factors. schedule is generated totally 1, 000 times and then optimal weight parameter is selected. The program is developed to schedule situation to compare with the performance measure, total finish time of machine and total tardiness of part. As a result, the rule which considered weighted sum of three factors is effective for both measure.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.342-350
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• 2018

The purpose of this study was to identify the environmental factors that affect the beginning and end of calling by Hyalessa fuscata and Cryptotympana atrata, which are dominant cicada species in the central urban areas of Korea. The study area was Banpo Apartments in Seoul. The research period included two months, being from the end of July to the end of August 2015. We analyzed the start and end time of cicada calling, and on average H. fuscata started calling at 5:21 am and C. atrata started at 7:40 am. The average end time of calling was 6:31 pm for H. fuscata and 7:51 pm for C. atrata. From the scatter plot and box plot results, H. fuscata started calling at 05:00 am, whereas C. atrata consistently stopped calling at 20:00 pm compared to H. fuscata. Multiple regression analysis of the start and end time of cicada calling showed that sunrise time was a factor affecting the start of H. fuscata calling. The end time of H. fuscata calling was affected by sunset time and total cloud cover. The starting time of C. atrata calling was mostly affected by temperature and sunrise time. The effect of temperature was greater than that of sunrise time. The end time of C. atrata calling was strongly affected by sunset time, whereas peak temperature was also shown to affect the end time. From the above results, sunrise and sunset are thought to be the critical factor affecting the start and end time of H. fuscata calling. Therefore, H. fuscata started calling with sunrise, and the end time was also affected by sunset. Temperature was the factor most affecting the start of C. atrata calling and sunset was identified as the factor affecting the end time. Therefore, the start time of C. atrata calling shows variation with daily temperature changes, and C. atrata stop calling simultaneously with sunset.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.3
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• pp.87-103
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• 2021

The government is trying to create jobs by providing 160 billion won in 2021 to revitalize youth start-ups, but the number of youth unemployment and potential unemployment is hitting a record high of 1.2 million due to the shock of employment due to COVID-19. Although start-ups are encouraged as an alternative to revitalizing jobs, the success rate of young start-ups is low due to lack of start-up funds and experience. The purpose of this study is to understand the need to diversify start-up education and career education by understanding start-up policies through one-time funding and short-term education. The results of the study on the factors affecting the willingness to start a business were as follows, by sampling 344 students from specialized high schools preparing for employment and 344 young people in their 20s who are seeking jobs. First, among the entrepreneurship subvariables, innovation, autonomy of job value, and desire for economic achievement are significant, and the older the person surveyed, the more positive the perception of the entrepreneur was. Second, as you get older, your will to start a business decreases, and your experience in successful start-up models and start-up education has an impact on your will to start a business. Third, perception of entrepreneurs is a partial medium effect, which indirectly influences the willingness to start a business and directly or indirectly influences the willingness to start a business through the autonomy of job values, the desire to achieve economic and entrepreneurship.

• Journal of Technology Innovation
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• v.31 no.2
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• pp.111-133
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• 2023

Innopolis start-up has become a representative model and path for commercialization of public technology. Along with the quantitative growth of innopolis start-up, the importance of innopolis start-up in national policies and institutional strategies related to public technology commercialization has also increased. However, over the past 16 years, innopolis start-up's establishment and growth have taken place in different ways at different times. This study aims to compare and analyze changes in innopolis start-up over the past 16 years, focusing on comparisons before and after 2014, when the establishment of innopolis start-up began to increase rapidly. Main findings are as follows. First, in the early stage of the quantitative expansion period, policy changes related to innopolis start-up were the main factors for the increase in innopolis start-ups. In addition, the rapid increase in the establishment of innopolis start-up after 2016 was largely influenced by changes in the start-up environment and institutional changes related to innopolis start-up. Second, the time of registration and size of the capital of innopolis start-up had a statistically significant effect on the sales for 3 years after registration. This result shows that with the rapid increase in innopolis start-ups, the need to build a customized support system for innopolis start-ups by size or growth stage has increased.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.169-179
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• 2005

In the 500m short track speed skating, the matter of who reaches the first corner first can important factor since each competitor races with all speed from the start to the first line. A filed study was attempted to kinematical estimation six female foreign skaters, who participated in the 500m female final round competition, and two Korea skates during the World Short track Skating Championship. The three dimensional motion analysis with DLT method was executed using four video cameras for analyzing the actual competition situation. In point of analyzing the actual competition situation, it is expected that skaters and coaches the effective informations, and the following conclusions are drawn; The elapsed time by phase in start motion of the foreign skaters appeared shorter those of Korea skaters, so the start training of Korea skaters should be strengthed. Also the displacement of C.G in the foreign skaters appeared shorter displacement than those of Korea skaters. Especially in the starting position, the foreign skaters are superior to Korea skaters in displacement of first(left) and next following stroke(right). The velocity of C.G and maximum velocity of skate blade of foreign skaters art faster than those of Korea skaters. And the foreign skaters show the superior early velocity change. Both of leaning body angle, and left and knee angle of the foreign skaters lead to positive point of having the propulsive force in the early starting position. Observing in the most prominent feature of foreign and Korea skaters in start phase, foreign skaters skate quickly the third stroke. These features of Korea skaters would appear disadvantage of location selection in entering the coner course.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.9-16
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• 2004

Close-coupled catalyst (CCC) can reduce the engine cold-start emissions by utilizing the energy in the exhaust gas. However, in case the engine is operated at high engine speed and load condition, the catalytic converter may be damaged and eventually deactivated by thermal aging. Excess fuel is sometimes supplied intentionally to lower the exhaust gas temperature avoiding the thermal aging. This sacrifices the fuel economy and exhaust emissions. This paper describes the results of an exhaust heat exchanger to lower the exhaust gas temperature mainly under high load conditions. The heat exchanger was installed between the exhaust manifold and the inlet of close-coupled catalytic converter. The exhaust heat exchanger successfully decreased the exhaust gas temperature, which eliminated the requirement of fuel enrichment under high load conditions. However, the cooling of the exhaust gas through the heat exchanger may cause the deterioration of exhaust emissions at cold start due to the increment of catalyst light-off time.

• Journal of ILASS-Korea
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• v.10 no.1
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• pp.17-23
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• 2005

Even though a relatively complete knowledge base has been established for diesel sprays, much of the knowledge cannot be directly translated to correlate the characteristics of gasoline spray. The macroscopic characteristics of gasoline impingement spray was investigated with photographic and image processing technique by Particle Motion Analysis System. The injector with single hole nozzle diameter of 0.28 mm was used in this experiment and the injection duration was selected as 10 msec. The injection pressure with 0.3, 0.35, and 0.4 MPa, impingement distance or 70, 100 and 130m, impingement angle or 0.15, 30 and $45^{\circ}$ were employed for the variables to affect the spray characteristics of impinging spray. It is clear that there is the analogy on the spray tip penetration between the gasoline impinging jet and diesel free jet. The spray tip penetration of impinging gasoline spray is proportional to the quarter power of the time after start of injection. The maximum height of impinging gasoline spray is also proportional to the quarter power of the time regardless of impingement distance, impingement angle and injection pressure. In addition, the effect of impingement angle on the spray tip penetration is significant according to the time after start of injection, even though there is minor effect in the initial stage of time after start of injection. Moreover, there is no remarkable effect of injection pressure on the spray tip Penetration under the experimental condition used in this study.

• Journal of Welding and Joining
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• v.15 no.6
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• pp.41-48
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• 1997

For analyzing the characteristics of arc welding processes, an algorithm is necessary to determine the metal transfer mode, arc stability and weld quality. In this study, the weight of spatter during welding was selected for determining the arc stability, which is very relevant to the occurrence of spatter. Weld spatter occurs mainly at the moment when the short circuit is formed and also when it is broken causing the arc to restrike. Based on this fact, the arc stability can be determined by finding the suitable parameters of welding current and arc voltage which influence the weight of spatter. Through various welding experiments, the peak current, the arcing time, the short circuit time, the current and its slope at the start of short circuit were found mainly to influence the weight of spatter. For the convenient usage, an index was proposed by combining all these parameters. It was found that the index is very effective for determining the arc stability.