• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3B
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• pp.271-278
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• 2006

In design of groyne series, groyne spacing is a important factor and have an effect on not only the characteristics of backward and recirculation flow in groyne zone but also flow field in main channel. It is necessary study about flow pattern of recirculation zone and main channel that is a cause of bad change, local scour and bank erosion by groyne spacing. In this study, flow variation of groyne zone and main chanel for spacing of groynes were analyzed from the experiment results in order to offer a fundamental data that can be used to decide the proper groyne spacing. Experiments were conducted 12 cases for groyne spacing(L) by groyne length(l) rate and the velocity profile was measured using LSPIV and ADV. From the results, two vortex flows developed in recirculation zone for L/l=3~9 and three vortex flows developed over L/l=10. The velocity of backward flow in recirculation zone was decreased up to 20% over L/l=4. The velocity of main channel flow was increased from 1.3 to 2.0 times by groyne spacing and the rate of velocity increased by increasing groyne spacing. The maximum velocity occurred in 0.7~0.8 times of groyne spacing downstream of upper groyne.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.707-717
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• 2006

As an alternative to conventional prestressed concrete (PSC) girders, various types of PSC girders are either under development or have already been applied in bridge structures. Incrementally prestressed concrete girder is one of these newly developed girders. According to the design concept, these new types of PSC girders have the advantages of requiring less self-weight while having the capability of longer spans. However, the dynamic interaction between bridge superstructures and passing trains is one of the critical issues concerning these railway bridges designed with more flexibility. Therefore, it is very important to evaluate modal parameters of newly designed bridges before doing dynamic analyses. In the present paper, a 25 meters long full scale PSC girder was fabricated as a test specimen and modal testing was carried out to evaluate modal parameters including natural frequencies and modal damping ratios at every prestressing stage. During the modal testing, a digitally controlled vibration exciter as well as an impact hammer is applied, in order to obtain precise frequency response functions and the modal parameters are evaluated varying with construction stages. Prestressed force effects on changes of modal parameters are analyzed at every incremental prestressing stage. With the application of reliable properties from modal experiments, estimation of dynamic performances of PSC girder railway bridges can be obtained from various parametric studies on dynamic behavior under the passage of moving train. Dynamic displacements, impact factor, acceleration of the slab, end rotation of the girder, and other important dynamic performance parameters are checked with various speeds of the train.

• Journal of the Korean Society of Food Culture
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• v.22 no.5
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• pp.621-632
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• 2007

The purposes of this study were as follows. First is to compare the importance of operational factors to determine types of school breakfast program, and second is to do the preference analysis of operation-related people depending on the attributes and levels of the operation of school breakfast program. The questionnaires developed for this study were distributed to 134 school dietitians, 114 school foodservice officials at the educational board, 68 staff members of foodservice contractors and 493 parents. Statistical data analyses were performed using SPSS/WIN 12.0 for descriptive statistics and conjoint analysis. The conjoint design was applied to evaluate the hypothetical foodservice types. According to the analysis on the attributes and levels of the school breakfast operation, the relative importance of each attribute was as followsprice (36.30%), menu (29.60%), foodservice staff (22.54%), serving type (11.55%) to school dietitians, price (34.99%), menu (28.15%), foodservice staff (23.52%), serving type (13.35%) to school foodservice officials at the educational board, menu (30.55%), price (30.24%), foodservice staff (28.75%), serving type (10.47%) to staff members of foodservice contractors and price (36.34%), menu (29.73%), foodservice staff (21.01%), serving type (12.92%) to parents. The results of the conjoint analysis indicated that the school dietitians and school foodservice officials at the educational board preferred the school breakfast operation program with 3 traditional menus and 2 convenience menus per 5 day, $1{\sim}3$ foodservice staff, with a price range of $1501{\sim}2000won$, and tray serving. Staff members of foodservice contractors preferred the school breakfast operation program with 3 traditional menus and 2 convenience menus per 5 day, $1{\sim}3$ foodservice staff, with a price range of $2501{\sim}3000won$, and tray serving. Parents preferred the school breakfast operation with 5 traditional menus per 5 day, $6{\sim}7$ foodservice staff, with a price range of $2501{\sim}3000won$, and tray serving. About a half of school dietitians considered that elementary schools were appropriate for the suggested school breakfast operation program. But, 68.2% of school foodservice officials at the educational board, 69.1% of staff members of foodservice contractors, and 38.1% of parents considered high schools to be the suitable model. Therefore, it indicated the need to recognize the different opinions among breakfast operation-related people and take these factors into consideration in developing the school breakfast program.

• 한국노년학
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• v.29 no.3
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• pp.789-803
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• 2009

We investigated the influences of positive thought about social capital on social participation of the elderly Koreans. The study design was cross-sectional analysis of the National Statistic Office Study of Korean Society Statistics Survey 2003. Participants were total of 8,586 representative samples. Two types of social participation were investigated: meeting attendance and volunteer obligations. The base model included five thoughts about social capital that must be settled as a priority in Korea, i.e., reducing the differences between the rich and the poor, reducing the crime rate, reducing regulations and corruption, improving the moral level, eliminating environmental pollution. Social participation was influenced by positive thoughts about social capital, and different kinds of thoughts had different influences on different types of social participation. The elderly who responded positively to 'reducing the differences between the rich and the poor' attended all two types of social participation more. Along with education and health status, positive thought about social capital is another important factor that influences increased social participation. It may also compensate for deteriorating health with increasing age by promoting social participation. Encouraging social participation is a good way to improve the health of the elderly, as are efforts to change thought about social capital positively.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.45-52
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• 2019

This study focuses on analyzing rhythms revealed in music songs of Korean third-generation idol girl groups. The development of genre and development of rhythm continues and the rhythm of Third World music is strong worldwide. The development of genres and rhythms continues and the rhythms of the Third World music are winning big popularity world wide. In the past, Third World rhythms were used only in countries where rhythm originated and neighboring countries, and the rhythms between countries were combined to occur in various conersence composite forms. In the past, the Third World rhythms were used only in rhythm-oriented countries and neighboring countries, and the rhythms between countries were combined in various and composite forms The changes in the global music market and the structure of the Korean pop music market show the same pattern in the local pop music genre. This study analyzes the phenomenon in which the Dembow rhythm and the tresillo rhythm, one of the rhythms of the Third World music, are concentrated in third-generation idol music, and notes that a certain number of combinations appear in rhythms and melodies. Moreover, this study identifies and compares the origin, the structure and the application cases of the Dembow rhythm and the tresillo rhythm by analyzing 12 songs of Korean third-generation idol girl groups. A game, as a sort of media like a movie, may be subjected to an ambivalent evaluation in accordance with the quality of each content. In this regard, it is necessary to have an active discussion about which game has desirable contents. Emotion which is an influential factor on interaction among players in game design needs to be approached from a social perspective. Also, based on social emotions associated with players, a significant relationship between emotional vocabularies and game emotions should be understood in comparison with social emotions within the game. based on social emotions regarding players As a result, social emotions within the game exhibited differences from the meaning of the terms. It is supposed that this result was caused by the ethical standards and differences in the real world. Accordingly, for qualitative enhancement of games, it is required to utilize the contents of this study, since emotions within the game are based on social emotions regarding players.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.355-363
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• 2023

In safety assessment of a aged bridge, dynamic characteristics and displacement are directly related to the rigidity of the structural system, especially displacement is the most important factor as the physical quantity that the bridge user can directly detect. However, in order to measure the displacement of the bridge, it is difficult to install displacement sensors at the bottom of the bridge and conduct traffic blocking and loading tests, resulting in increased costs or impossible measurements depending on the bridge's environment. In this study, a method of measuring the displacement of a bridge using only accelerometers without installing displacement sensors and ambient vibration without a loading test was proposed. For the analysis of bridge dynamic characteristics and displacement using ambient vibration, the mode shape and natural frequency of the bridge were extracted using a TDD technique known to enable quick analysis with simple calculations, and the unit load displacement of the bridge was analyzed through flexibility analysis to calculate static displacement. To verify this proposed technology, an on-site test was conducted on C Bridge, and the results were compared with the measured values of the loading test and the structural analysis data. As a result, it was confirmed that the mode shape and natural frequency were 0.42 to 1.13 % error ratio, and the maximum displacement at the main span was 3.58 % error ratio. Therefore, the proposed technology can be used as a basis data for indirectly determine the safety of the bridge by comparing the amount of displacement compared to the design and analysis values by estimating the displacement of the bridge that could not be measured due to the difficulty of installing displacement sensors.

• Membrane Journal
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• v.33 no.6
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• pp.352-361
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• 2023

Steam methane reforming is currently the most widely used technology for producing hydrogen, a clean fuel. Hydrogen produced by steam methane reforming contains impurities such as carbon monoxide, and it is essential to undergo an appropriate post-purification step for commercial usage, such as fuel cells. Recently, membrane separation technology has been gaining great attention as an effective purification method; in this study, we evaluated the feasibility of using commercial polysulfone membranes for biogas upgrading to separate and recover hydrogen from a hydrogen/carbon monoxide gas mixture. Initially, we examined the physicochemical properties of the commercial membrane used. We then conducted performance evaluations of the commercial membrane module under various conditions using mixed gas, considering factors such as stage-cut and operating pressure. Finally, based on the evaluation results, we carried out simulations for process design. The maximum H₂ permeability and H₂/CO separation factor for the commercial membrane process were recorded at 361 GPU and 20.6, respectively. Additionally, the CO removal efficiency reached up to 94%, and the produced hydrogen concentration achieved a maximum of 99.1%.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.102-110
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• 2023

This paper introduces scarf welding process of thin substrates using flexible laser transmission welding (f-LTW) technology. We examined the behavior of tensile strength relative to the scarf angle for flexible applications. Thin plastic substrates with the thickness of less than 100 ㎛ were bonded and a jig to form a slope at the edge of the substrate was developed. By developing the scarf welding process, we successfully created a flexible bonding technology that maintains joint's thickness after the process. The tensile strength of the joint was assessed through uniaxial test, and we found that the tensile strength increases as the slope of bonding interface decreases. By conducting stress analysis at the bonding interface with respect to the slope angle, design factor of bonding structure was investigated. These findings suggest that the tensile strength depends on the geometry of the joint, even under the same process conditions, and highlights the significance of considering the geometry of the joint in welding processes.

• Korean Journal of Culture and Social Issue
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• v.14 no.1
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• pp.47-75
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• 2008

Research on moral judgment has been dominated by rational factor or moral emotion, in which moral judgment is thought to be caused by moral reasoning or moral intuitions. This research demonstrates that offender' anger can influence moral judgment. The study examined the role of offender's anger (control group versus anger group) on moral domain ( life, interpersonal ethic, traffic regulation: 6 case) : 2(groups) ×6(cases) mixed design. Participants were asked to judge the offender, case, sympathy and one's anger about the him or her who offended against the law or convention. Participants who perceived the offender's anger tended to assess questionnaire generous. In interpersonal ethic domain, participants have not been affected by anger. There was not significantly differences between two groups in interpersonal ethic domain. The results of experiment confirmed hypotheses that influence of anger varies with the moral domains affected a value system of culture. These findings indicate functional emotion for moral judgment and suggest people may be decide how much emotion is considered on moral judgment performance according to moral domains.

• Korean Journal of Culture and Social Issue
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• v.11 no.4
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• pp.45-66
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• 2005

This study verified the effects of violent PC games and aggressive personality on aggressive behavior and aggressive intention as predicted by GAM in Anderson and Bushman (2002), and a correlational study and experimental research were carried out to corroborate a differences of the effects of the two variables according to the developmental levels. The correlational study showed that aggressive personality was an explanatory variable for aggressive behavior; however, exposure to violent PC games was not a significant factor, contrary to the predictions by GAM. It has been clarified that the effects of the two variables influenced aggressive behavior in a different way according to the developmental levels. Further, no positive relation existed between repetitive (chronic) violent PC game plays and aggressive personality. The experimental research analyzed the differences of aggressive intention in each of the experimental conditions designed with a 2(PC games types: violent vs. non-violent) x 2(aggressive personality: high vs. low) x 2 (developmental levels: middle school boys and college students) between-subjects factorial design. As a result, violent PC games had an effect on aggressive intention for the middle school boy group, while it was supported that aggressive personality had an effect on aggressive intention for both middle school and college students. Noticeably, the primary hypothesis in the study has been supported that the effects of violent PC games and aggressive personality on aggressive intention vary according to different age groups. In conclusion, the effects of violent PC games and aggressive personality as predicted by GAM have been confirmed in parts; however, future studies on GAM must be necessarily supplemented with the developmental perspectives, as it has been ascertained that the effects of the variables vary according to the developmental levels.