• Journal of Fashion Business
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• v.15 no.4
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• pp.87-109
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• 2011

This study was to examined the relationship between goal setting, self improvement, social support of parents, friendship, school adaptation, drop out. In our research model, goal setting, self improvement, social support of parents, and friendship is exogenous variable and school adaption and drop out is endogenous variable. A total of 323 undergraduate student(254 female, 69 male) complete the questionnaires. Structural equation modelling showed that, as hypothesized, establishment of goals, social support of parent and friendship have effect on school adaptation, and friendship also have direct effect on drop out. School adaptation mediate path from goal setting, social support of parents, and friendship. This study provides empirical evidence for a model that show how to control the drop out of students.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.2
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• pp.75-83
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• 2015

Advanced countries in the aviation industry, especially the United States and European Union, develop and commercialize their own SBD system integrated with IT convergence technology, dominating the international market. Nevertheless, most of SBD technologies in domestic airports rely on other countries. It is imperative that internal airport operators introduce the Self Bag Drop system and produce, apply, and manage the most optimized SBD system for airports and airlines. Upon analyzing the tendency and operation of the SBD system utilized in leading international airports, this is conducted to address the possibility of the future implementation in domestic airports.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.228-233
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• 2004

The spray and acoustic characteristics by the self-oscillation of a swirl coaxial injector were experimentally studied. The self-oscillation of a swirl coaxial injector is defined as pressure and flowrate oscillations by a time-delayed feedback between liquid and gas phase and has strong influences on atomization and mixing processes. Hence the occurrence and effect of the self-oscillation are measured using shadow photography technique, acoustic test and PDPA. The occurrence of self-oscillation largely depends on the injection conditions, such as pressure drop of liquid phase and relative momentum ratio. From the experimental results, self-oscillation occurs when the momentum of gas phase is enough large and the smaller the pressure drop of liquid phase is, the better self-oscillation occurs at the same momentum ratio. The self-oscillation is also affected by injector geometries, increasing the recess length results in the expansion of self-oscillation region and the increase of sound pressure level. The self-oscillation of a swirl coaxial injector accompanies a high intensity scream and this scream may provide harmful disturbances to combustion processes. Self-oscillation leads to strong changes in the drop size distribution and smoothly varies the slope of radial SMD distribution.

• Industry Promotion Research
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• v.8 no.2
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• pp.81-91
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• 2023

This study aims to present basic data for preventing drop-out intention by identifying the mechanisms in which academic stress affects drop-out intention through self-esteem, peer relationships, and grit in high school students. The subjects of the study were 283 high school students purposively selected from three cities and counties in Chungcheongnam-do. The data were analysed using SPSS PC+ Win. ver. 25.0 and SPSS PROCESS macro ver. 4.2. The applied statistical techniques were descriptive statistics, reliability analysis, correlation analysis, and moderated mediation effect analysis. As a result of the study, first, academic stress showed a positive correlation with the drop-out intention, but a negative correlation with self-esteem, grit, and peer relationship. Second, grit not only played a moderating role in enhancing the relationship between self-esteem and peer relationship, but also played a moderated mediating role in the path of academic stress → self-esteem → peer relationship → drop-out intention. It was confirmed that the academic stress of high school students has a direct effect on the drop-out intention, and that self-esteem, peer relationships, and grit can be used as important factors to prevent the school drop-out.

• Journal of Advanced Navigation Technology
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• v.20 no.2
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• pp.107-115
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• 2016

The passenger who use airport spend a lot of time in check-in. They are also delayed in their readiness for departure. Therefore, for decrease in time that is waiting time for handling luggage, recently many airports are expanding self-service. Also internal development and manufacturing for production automation system and IT technology are world-class. So, for localization of self bag drop (SBD) system, I think that application this system in domestic technique and constructing competitive in customer reception system will be efficient airport management. To this end, for looking for optimal conditions when passengers use SBD, this thesis include development simulation of relevance to system. Also this thesis secures information for passenger's in foreign country airport and simulate this data. Finally, that analysis the best management passenger system when the passenger use SDB.

• Current Optics and Photonics
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• v.2 no.1
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• pp.23-26
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• 2018

Optical-layer restoration has been demonstrated with a wavelength-blocker (WB) -based reconfigurable optical add/drop multiplexer (ROADM). Two $2{\times}2$ optical switches with a control circuit were placed before and after a WB-based ROADM to provide automatic path restoration under fiber-failure conditions. Using the proposed node configuration, a 3-node self-healing ring (SHR) network has been implemented to demonstrate the feasibility of the automatic optical-layer restoration. From the results, the restoration time was measured to be ~4 ms under fiber-failure conditions, without any additional power penalty in receiver sensitivity.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.6
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• pp.457-462
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• 2022

Recently, a variety of cultural life using drones as an entertainment tool has been created, and in order to realize this, more and more users are using drones with good performance enough to invade the no-flight zone. Drones for satisfying entertainment activities must have long flight times and be able to fly long distances, which can often cause great damage by invading no-flight zones or causing unwanted flight crashes. In this study, in order to solve this problem, a no-flight zone is set with GCS(Ground Control System), and when flying at a critical speed of 10km/h or less, the drone is safely operated by not entering the critical distance 10m away from the no-flight zone, and the critical speed A method was proposed to prevent the drone from entering the no-flight zone by allowing the drone to self-drop by GCS control when it flies beyond the threshold and enters the critical distance. As a result of a total of 44 repeated experiments in a specific experimental area with the proposed method, the drone safely self-dropped except for the case where it crossed the restricted area once or twice. It was found to be an appropriate way to prevent this.

• Korean Journal of Social Welfare
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• v.61 no.4
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• pp.191-215
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• 2009

The purposes of this study were to investigate the factors that influence the school drop-out of North Korean refugee youth and to generate recommendations for social work practice and the resettlement policies of the government to ameliorate the high school drop-out rate among North Korean refugee youth. This study examined the effects of the environmental factors such as the quality of parenting practice, peer attachment and the kind of school a youngster attends, and personal characteristics such as self-respect and acculturation stress level, and academic efficacy on the school drop-out intention. Gender, duration of stay in Korea, family economic status were established as control variables. The drop-out intention was used as a proxy for drop-out behavior. The study findings indicate that the personal characteristics such as gender, self-respect and acculturation stress, academic efficacy were the significant influencing factors, whereas environmental factors such as quality of parenting, peer attachment did not exert any statistically significant effect on the drop-out intention. At the conclusion, the implications of the study findings for research, social work practice and the government policies were discussed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.3
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• pp.55-65
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• 2018

The SBD systems have made it possible that all boarding procedures are completed by passengers. With the SBD, air tickets can be issued and baggage can be consigned without the help of airline officers. This way, the SBD can improve the passenger circulation speed as well as decrease the time for passengers to wait for check-in, which is connected to the reduction of airlines' operaitonal costs. However, given that the SBD is a new technology, it has potentials to be used as a tool for air terrorism. This study purposes to determine methods to enhance the security and operation of SBD systems. With the aim, this paper investigated the existing literature on SBDs, self-check-in, airport security, air terrorism, risk management, aviation accidents, and information security. In order to compile real-time information about the SBD operations, twelve airports in North America, Europe, and Asia were analyzed based on existing studies on international SBD trends.

• Journal of ILASS-Korea
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• v.10 no.3
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• pp.29-37
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• 2005

The spray and acoustic characteristics of a gas/liquid swirl coaxial injector are studied experimentally. The self-pulsation is defined as a pressure and flow rate oscillations by a time-delayed feedback between liquid and gas phase. Self-pulsation has strong influences on atomization and mixing processes and accompanies painful screams. So. the spray and acoustic characteristics are investigated. Spray patterns are observed by shadow photography technique in order to determine the onset of self-pulsation. And self-pulsation boundary with Injection conditions and recess length is get. To measure the frequency of the spray oscillation. oscillation of the laser intensity which passes through spray is analyzed by Fast Fourier Transform. For acoustic tests, a PULSE System was used. Acoustic characteristics of a swirl coaxial injector are investigated according to the injection conditions. such as the pressure drop or the liquid and gas phase. and injector geometries. such as recess length and gap size between the inner and outer injector. Front the experimental results. the increase of recess length leads to the rapid increase of the sound pressure level. And as the pressure drop of the liquid phase increases. the frequency of the self?pulsation shifts to the higher frequency. The frequency of spray oscillations is the same as that of the acoustic fields by self-pulsation.