• Journal of Korean Elementary Science Education
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• v.33 no.3
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• pp.439-452
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• 2014

The purpose of this study is to find out the effect of STEAM program on the scientific communication skills and the learning flow of elementary gifted students. The main findings of this study are as follows: First, STEAM program that mathematical, technical, engineering and art factors were combined based on basic concepts of science were developed. Seconds, the change in the scientific communication skills of experimental group applying STEAM program had statistically meaningful difference (p<.05). Third, the flow of experimental class improved, but it had no meaningful difference statistically (p>.05). But it is expected that continuing level adjusted STEAM program might have positive effect on improving the flow with the following three reasons: 1) The gifted students' flow level on learning before experiment was rather too high to expect short term effect. 2) It was hard for them to achieve flow experience because topic difficulties and students' capacities were not balanced. 3) topic commitments and autotelic behaviors of gifted students were observed during classes. Fourth, by the result of the student satisfaction questionnaire survey on this program, students actively participated in the STEAM program with interest and curiosity. As achieved self-directed problem solving, versatile communication activities and success experiences, their class satisfaction was high. Based on such results, it was expected that the gifted class applied of STEAM program could enhance scientific communication capacity of the elementary gifted students and would further positively influence flow of learning as well. In addition, it was considered to have integrated approach value to elementary gifted and talented education in the aspect that it could satisfy various educational demands of gifted students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.459-468
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• 2016

The purpose of this study was to examine the relationship among flow, satisfaction, service quality, and revisiting intention of college ski class participants. By analyzing a total of 106 college students from a university in G city, this study found the following. First, the flow of ski classes had a positive influence on the satisfaction with the ski class. Second, the satisfaction with the ski classes had a positive influence on the service quality of the ski resort. Third, the service quality of the ski resort had a positive influence on the revisit intention. Fourth, the flow of the ski class had a positive influence on the service quality of the ski resort mediated by the satisfaction of the ski class. Fifth, the satisfaction of the ski class had a positive influence on the revisiting intention mediated by the service quality of the ski resort.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.9
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• pp.39-48
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• 2008

Recently, many multimedia services have emerged in Internet such as real-time and non- real time services. However, in this Internet environment, we have some limitations to satisfy each service feature. To guarantee the service features in Measurement-Based Admission Control(MBAC) based system on the flow-aware network, there is the method applying Dynamic Priority Scheduling(DPS) algorithm that gives a higher priority to an earlier incoming flow in all of the link bandwidth. This paper classifies all flows under several groups according to flow characteristics on per-flow MBAC algorithm based system. In each flow group, DPS algorithm is applied. This paper proposes two methods that are a DPS based bandwidth borrowing method and a bandwidth dynamic allocation method. The former is that if low priority class has available bandwidths, the flow of high priority class borrows the bandwidth of low priority class when high priority flow has insufficient bandwidth to connect a flow call. The later is that the each group has a minimum bandwidth and is allocated the bandwidth dynamically according to the excess rate for available bandwidth. We compare and analyze the characteristics of the two proposed methods through the simulation experiments. As the results of the experiment, the proposed methods are more effective than existing DPS based method on the packet loss and delay characteristics. Consequently the proposed two methods are very useful in various multimedia network environments.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.6
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• pp.1271-1280
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• 2017

The android packer service using runtime execution compression technology switches to the original application using DexClassLoader. However the API interface of the DexClassLoader receives the path of the loaded DEX(Dalvik EXcutable) and the path of the compiled file. So there is a problem that the original file is exposed to the file system. Therefore, it is not safe to use the API for the packer service. In this paper, we solve this problem by changing the compile and load flow of the DexClassLoader API. Due to this changed execution flow, the complied file can be encrypted and stored in the file system or only in the memory and it can be decrypted or substituted at the time of subsequent loading to enable the original application conversion. we expected that the stability of the packer will increase beacause the proposed method does not expose the original file to the file system.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.941-948
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• 2021

This study investigated the differences between active and inactive TV watching groups, in terms of residential characteristics, of class-oriented drama viewing rate. We compared Flow and Social Comparison Theories to explain the relationship between class-oriented contents in the drama and viewing rate. We collected 110,000 TV viewers data of 4 class-oriented and the other 4 dramas, aired between Feb. 2016 and March 2019, through D-Live local cable service provider. Controlling gender ratio and income level which may affect viewing rate, we found that class-oriented content significantly and positively affects viewing rate in active watching group while the same content significantly and negatively affects viewing rate in inactive watching group. These results imply that Flow and Social Comparison Theories may apply in opposite directions in different watching groups.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.26-37
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• 2011

A 75-tonf-class LRE(liquid rocket engine) thrust chamber with ablative material for technology demonstration was manufactured on the basis of development technologies of 30-tonf-class LRE. Hydraulic characteristics of the thrust chamber were examined through cold flow test and ignition test of low flow condition. Test result showed that hydraulic function was good. Side ignition method with igniter ring also showed a fine function of ignition in operating ways of static condition. But a close review is required to understand the phenomena of generation and extinction of specific frequencies showed in dynamic characteristics ways. To achieve these, a large combustion test facility which is capable of performing combustion test at design condition of the 75-tonf-class thrust chamber should be constructed as soon as possible.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.233-243
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• 2015

The bimodal flocculation of cohesive sediments in water environments describes the aggregation and breakage process developing a bimodal floc size distribution with dense flocculi and floppy flocs. A two class population balance equation (TCPBE) was tested for simulating the bimodal flocculation by a model-data fitting analysis with two sets of experimental data (low and high turbulent flows) from 1-D flocculation-settling column tests. In contrast to the Single-Class PBE (SCPBE), the TCPBE could simulate interactions between flocculi and flocs and the flocculation mechanism by differential settling in a low turbulent flow. Also, the TCPBE could perform the same quality of simulation as the elaborate Multi-Class PBE (MCPBE), with a small number of floc size classes and differential equations. Thus, the TCPBE was proven to be the simplest model that is capable of simulating the bimodal flocculation of cohesive sediments in water environments and water, wastewater treatment systems.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.5
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• pp.703-710
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• 2010

Recently, small hydropower attracts attention because of its clean, renewable and abundant energy resources to develop. However, suitable turbine type is not determined yet in the range of small hydropower and it is necessary to study for the effective turbine type. Therefore, a 80kW-Class cross-flow turbine is adopted in this study because of its simple structure and high possibility of applying to small hydropower. The result shows that as effective head increases, tangential and radial flow velocities increase and thus, the increased tangential velocity contributes to the increase of angular momentum and output torque.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.735-749
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• 2021

There is true that the evaluation of non-face-to-face swimming classes currently offered by universities due to the COVID-19 outbreak is generally negative. For this reason, the quality of non-face-to-face swimming classes at universities is bound to depend on the expertise of the instructor. However, whether or not of students who lack of practices of swimming could experience exercise flow and could continuously last the swimming exercise after semester or even graduation is difficult to confirm. This is considered to be a significant threat in the future not only for swimming, but also for all liberal arts and lifestyle sports. This study aimed at 281 non-athletic college students with experience of taking both swimming classes, and the need for a study on the structural relationship between exercise flow and participation intention by university swimming class leaders' expertise in non-sports majoring college students. And the results were empirically analyzed. The research results derived in this process are summarized as follows. First, the effect of swimming class leader's expertise (personality, lecture skills, student management, practical skills, basic knowledge) perceived by non-athletic college students on exercise flow (cognitive flow, behavior flow) affects cognitive flow. As a factor influencing, it was found that lecture skills had a statistically positive (+) effect, and as factors influencing behavioral commitment, the positive (+) effect was statistically significant in personality, lecture skills, student management, and basic knowledge. Second, as for the effect of exercise commitment (cognitive commitment, behavior commitment) perceived by non-athletic college students on continuous participation intention, the behavioral commitment factor was found to have a statistically positive (+) effect.

• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.5-11
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• 2012

This study is to develop a 1kW-class horizontal axis wind turbine(HAWT) rotor blade which will be applicable to relatively low wind speed regions in southwest islands in Korea. Shape design of 1kW-class small wind turbine rotor blade is carried out using a blade profile with relatively high lift to drag ratio by blade element momentum theory(BEMT). Aerodynamic analysis on the newly designed rotor blade is performed with the variation of tip speed ratio. Power coefficient and pressure coefficient of the designed rotor blade are investigated according to tip speed ratio.