• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2119-2125
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• 1992

An air-fuel ratio control method is studied to keep the air-fuel ratio of the exhaust gas in the neighborhood of the stoichiometric air-fuel ratio to maximize the conversion efficiency of the three-way catalytic converter. Estimators, which estimate the air-fuel ratio of the exhaust gas, are proposed using neural networks to overcome the limit of the presently used bang-bang type exhaust gas oxygen sensor. Using these estimators, PI controller for air-fuel ratio control is designed and is experimented for an automobile engine. The proposed controller reduces the variation of air-fuel ratio of the exhaust gas from the stoichiometric air-fuel ratio by 50%-75% when compared to the existing controller.

• Journal of ILASS-Korea
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• v.5 no.3
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• pp.9-16
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• 2000

In a SI engine, three-way catalyst converter has the best efficiency when A/F ratio is near the stoichiometry. The feedback control using oxygen sensors in the commercial engine has limits caused by the system delays. So it is necessary to control fuel quantity in accordance with intake air amount in order to reduce exhaust emission and improve the specific fuel consumption. Precise A/F ratio control requires measurement of air amount with respect to the cylinder and injection fuel according to the air amount In this paper, we applied nonlinear fuel injection model and developed the algorithm of A/F ratio control. This algorithm includes the methods of measurement of transient air mass flowing into each cylinder, of calculation of injection pulse width for measured air mass, and the method of feedback and engine control by using lambda sensor. Also we developed control program for IBM-PC by using C++ Builder, and tested it in the commercial engine.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.458-466
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• 2011

JeJu Island is famous for beautiful scenery but relatively little attention was paid to social cultural attractions. My aim is to provide an alternative attraction for JeJu destination. Two main goals of this paper are to apply to the Pine and Gilmore Experience Economy Theory framework on performance arts experiences and identify causal relations among experience factor, experience satisfaction and performance loyalty. To accomplish the study object, theoretical review and empirical analysis were jointly carried out. Using samples of 280 participations in nonverbal comic performance 'Nanta' who were required to rate performance experiences, experiences satisfaction, and performance loyalty. Results of SEM(Structured Equation Model) was showed that only Entertainment factor of 4 experiences factors(aesthetics, entertainment, education, escapist) affected experiences satisfaction. While experiences satisfaction affected performance loyalty. These results support the concept of experiential Economy framework suggested by Pine and Gilmore on culture-arts products consumption.

• Journal of Service Research and Studies
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• v.13 no.4
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• pp.47-69
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• 2023

The main purpose of this study is to examine the mediating effects of performance satisfaction and audience loyalty through the motivation and community satisfaction of non-profit performance attendees in the local community. Motivations were examined by distinguishing between intrinsic and extrinsic factors to understand the profound desires of the audience. A survey was conducted targeting attendees who had experienced non-profit performances in the Jeju area over the past year to gather data. Ultimately, the survey responses from 363 participants were used as the basis for analysis. The results of the analysis indicated that higher levels of intrinsic and extrinsic motivations generally led to greater satisfaction and loyalty towards performances (H1, H2, H3). However, extrinsic motivation did not directly influence loyalty (H4). Nevertheless, both types of motivations were found to positively influence loyalty through performance satisfaction (H5, H8). While satisfaction with performances did not have a direct impact on community satisfaction (H6), audience loyalty was found to have a positive influence on community satisfaction (H7). Regarding motivations, performance satisfaction did not mediate the relationship between motivations and community satisfaction (H9). In the case of audience loyalty, intrinsic motivation showed mediating effects, while extrinsic motivation did not (H10). The process of motivation-satisfaction-loyalty-community satisfaction demonstrated a sequential pathway (H11). In conclusion, if local residents show interest and participate in non-profit performances, they develop a positive perception of the respective community. Therefore, performances provided at the local level should be recognized as crucial elements for the development of the community.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.23-30
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• 2016

The conventional natural gas engine realized lean combustion for the improved efficiency. However, in order to cope with exhaust gas regulations enforced gradually, the interest has shifted at the stoichiometric mixture combustion system. The stoichiometric mixture combustion method has the advantage of a three-way catalyst utilization whose purification efficiency is high, but the problem of thermal durability and the fuel economy remains as a challenge. Hydrogen-natural gas blend fuel (HCNG) can increase the rate of exhaust gas recirculation (EGR) because the hydrogen increases burning speed and lean flammability limit. The increase in the EGR rate can have a positive impact on heat resistance of the engine due to the decreased combustion temperature, and further can increase the compression ratio for efficient combustion. In this study, to minimize the exhaust emission developed HCNG engine with stoichiometric combustion method, developed three-way catalyst was applied to evaluate the conversion characteristics. The tests were carried out during the steady state and transient operating conditions, and the results were compared for both the conventional and proto-three-way catalyst of HCNG engine for city buses.

• (The) Research of the performance art and culture
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• no.40
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• pp.5-35
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• 2020

Affect is intensity and quality that are generated as the physical body senses the outside world. Of experienced affect, notions that are granted meaning and interpretation are emotions. Affect theory distinguishes emotion and affect and by focusing on affect, it provides methods with which to analyze physical body responses and changes and it presents new possibilities to performing arts research that uses the physical body as a medium. Nong-ak is art that concentrates mainly on the occurrence of affect rather than 'representation'. Nong-ak is a performance type in which sound, color, texture, and physical movement overlap and exist in a synesthetic way. Here, physical things such as instruments, props, costumes, and stage devices are gathered together with non-physical things such as rhythm, mood, and atmosphere around human bodies. The physical body is stimulated by these things, displays tendencies that suit performances, and becomes 'the body without an image' as it immerses itself into the performance, acting while displaying 'quasi-corporeality'. The body, which moves automatically as if without consciousness, appears more easily within groups. To transition individuals of everyday life to 'the body without an image', Nong-ak executes the group physical exercise of 'Jinpuri'. Such physical exercise builds up affect by increasing nonverbal communion and communication and brings out the creativity of individuals within mutual trust and a sense of belonging. Affect and emotion stirred up by Nong-ak act as confirmation and affirmation of the existence, vitality, and ability of one's self and groups. Such affirmation recalls Nong-ak as a meaningful and important value from group dimensions and perceives it as a performance form that should be preserved and passed on.

• Journal of the Korean Institute of Gas
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• v.12 no.3
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• pp.13-19
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• 2008

Among the various prime movers for combined heat and power (CHP) system, the CNG engine is the most commonly used power generation equipment of which power is less than 1MW. The 300 kW class CNG engine for CHP can meet stringent emission regulations with the adoption of stoichiometric air-fuel ratio control and three way catalyst. As the thermal efficiency of the stoichiometric ratio engine is lower than that of lean burn engine, it is necessary to operate the stoichiometric engine at its minimum spark advance for the best torque (MBT). However, knock control should be introduced for the engine under high intake air temperature conditions because MBT operating conditions are generally very close to those of knock occurrence. In this study, engine performances and knocking characteristics were experimentally investigated for the CNG engine that needs to be operated at higher intake air temperature conditions than normal conditions.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.40-46
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• 2015

Stoichiometric combustion engine with Three-way catalyst had an advantage that can reduce the harmful emissions effectively. Fuel equivalence ratio controlled from engine is very important because Fuel equivalence ratio with high conversion efficiency was narrow. This study analyzed the conversion efficiency under whole range of operating area for to evaluate the performance of three-way catalyst. In order to identify the Optimum conversion efficiency, the conversion efficiency due to change the control value of fuel equivalence ratio was investigated. The result show that conversion efficiency of emissions(more than 95%) has discovered by means of fuel equivalence ratio control at each test condition. As engine power increases, optimal fuel equivalence ratio tended to increase linearly under operating conditions of similar exhaust gas temperature.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.587-592
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• 2010

A numerical analysis of reactive flow in a MILD(Moderate and Intense Low oxygen Dilution) combustor is accomplished to elucidate the characteristics of combustion phenomena in the furnace with the variation of air fuel ratio. For the smaller magnitude of air injection velocity(10 m/s), the air flow could not penetrate toward upper part of furnace. On the other hand, the air flow suppresses the fuel flow for the case of air injection velocity 30 m/s. The air velocity 18 m/s is corresponding to the stoichiometric air flow velocity, and for that case, the air flows to relatively more upper part of the furnace when compared with the case of air injection velocity 10 m/s. The reaction zone is produced with the previous flow pattern, so that the reaction zone of the air injection velocity 10 m/s is biased to the air nozzle side and for the case of air injection velocity 30 m/s, the reaction zone is inclined to the fuel nozzle side. For the cases with the air injection velocities 16, 18, 20 m/s, the reaction zone is nearly located at the center between air nozzle and fuel nozzle. The maximum temperatures and NOx concentrations for the cases of air injection velocity 16, 18, 20 m/s are lower than the cases with air injection velocity 10, 30 m/s. From the present study, the stoichiometric air fuel ratio is considered as the most optimal operating condition for the NOx reduction.

• (The) Research of the performance art and culture
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• no.35
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• pp.61-92
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• 2017

During the Japanese colonial era, traditional music performances were gradually diminishing and weakening in the particular condition of colonization. Meanwhile, from the time of enlightenment, Western genre performances were becoming vitalized with the influence of Western civilization that began to be spread steadily throughout the society. In that situation, traditional music performances tended to be mixed performances accompanied by Western ones, not independent performances. Mostly, they were accompanied by Western music, and also, they were performed along with other genres like plays, lectures, movies, dances, or magic, too. Such form of mixed performances accompanied by Western genres became even more vitalized in the 1920's and came to be positioned as a form of traditional music performances. Therefore, research on the forms of mixed performances between Western genres and traditional music is meaningful in examining the forms of traditional music performances that have not been studied in the history of Korean modern music and understanding the trends of traditional music performances which were generally found in the Japanese colonial era. However, such research has hardly been conducted concretely yet. Accordingly, concerning the forms of mixed performances between Western genres and traditional music in the 1920's, this author considered the background of vitalizing mixed performances between Western genres and traditional music mainly with newspaper articles of the time and their formal characteristics. Regarding the background of vitalizing the forms of mixed performances between Western genres and traditional music, from the 1920's, the forms of mixed performances between Western genres and traditional music became more vitalized than before. The causes of that may include the increase of groups hosting or sponsoring such performances from the 1920's and also the dramatic increase of such performances in general. Moreover, the increased performances were conducted in the forms of mixed performances mainly in order to satisfy the people's needs becoming diversified with the distribution of Western civilization. Concerning the formal characteristics of mixed performances between Western genres and traditional music, this researcher classified western genres performed with traditional music and examined what characteristics were found in such mixed performances of tradition music by the types of Western genres respectively. First, in the mixed performances type of western-type genre and traditional music, the number of programs for the western music had significant portion in general, and there were certain ensemble of the western music and traditional musical instrument that was rare at this period of time, and it also had the characteristics of classifying two genres to perform for each title or date. Second, in the mixed performances type of the drama and traditional music, the traditional music is directly participated in the drama with the similar type to the theater, or performed independently from the drama with the role of interlude performance for the stage conversion of the drama to have the characteristics of performing in audience publicity or entertainment. Third, in the mixed performances type of the lecture and traditional music, the traditional music is played before or after the lecture to play the role to set the atmosphere and entertainment for the lecture as displaying the feature to perform for the audience attraction. And, fourth, in the mixed performances type of the movie and traditional music, the traditional music sometimes directly participated in the movie or had the features of independent performance, and there was a characteristic to perform for the entertainment after showing a movie.