• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.639-648
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• 2015

Some materials of fatty acids in the biodiesel affect the physical/chemical properties like density, kinematic viscosity, total acid number and oxidation stability by forming an organic fatty acid in combination with oxygen in the air. To solve the problem of the oxidative stability of biodiesel, various kinds of antioxidant has added and analyze the characteristics of the physical/chemical property changes by the addition of antioxidant. Oxidation stability increased by the increase of additives content. The TBHQ among the seven kinds of the additives showed the best performance. Also, 4 kinds of additives like propyl gallate, butyl-amine and pyrogallo has showed above 10 hr of oxidation stability at the addition of 500 ppm. In case of pyrogallo, this is not appropriate as an additive to suitable quality standards of total acid number. TBHA, DTBHQ of hydroquinone was satisfied with the quality standard of oxidation stability but the target of this research(above 10 hr) did not satisfied with oxidation stability. Propyl gallate is also a suitable at the quality standards of total acid number but it was shown not to be an appropriate to the additives due to increasing the total acid number by increasing of the content of additives at the addition of 500 ppm.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.262-272
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• 2007

SAD (Sum of Absolute Difference) algorithm is the most frequently executing routine in motion estimation, which is the most demanding process in motion picture encoding. To enhance the performance of motion picture encoding on a VLIW processor, an optimal implementation of SAD algorithm on VLIW processor should be accomplished. In this paper, we propose an implementation of optimal scheduling of SAD algorithm with conditional branch on a VLIW-based high performance DSP. We first transform the nested loop with conditional branch of SAD algorithm into a single loop with conditional branch which has a large enough loop body to utilize fully the ILP capability of VLIW DSP and has a conditional branch to make the escape from loop to be achieved as soon as possible. And then we apply a modulo scheduling technique to the transformed single loop. We test the proposed implementation on TMS320C6713, and analyze the code size and performance with respect to processing time. Through experiments, it is shown that the SAD implementation proposed in this paper has small code size appropriate for embedded applications, and the H.263 encoder with the proposed SAD implementation performs better than other H.263 encoder with other SAD implementations.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.179-194
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• 2016

The purpose of this study is to find out how the reconstructed textbook for vocational high school students influences on students' scholastic achievement and affective domain when it is used in the class of vocational high school. To tackle the study problems, the researcher chose two classes of the first grade in G commercial high school and gave lessons to each of the two classes; one class, as an experimental group, was taught with the reconstructed textbook and the other, as a comparative group, was taught with the original textbook. The following results are derived from the study. First, it turned out in the post academic achievement test result, there is no significant difference between the experimental group and the comparison group, by significant level; .05. However, the prior academic achievement test result shows that the average of the comparison group is 0.44 points higher than the average of the experimental group, while the post test result shows that the average of the experimental group is 1.96 points higher than the average of the comparison group. Second, it turned out by the post affective domain test result, there is no significant difference between the experimental group and the comparison group, by significant level; .05, and any significant difference did not occur in all five areas. However, the whole point of the affective domain and the points of each area of experimental group are higher than those of the comparison group, and the degree of improvement in experimental group is also greater than that of the comparison group. In conclusion, the effectiveness of utilizing a reconstructed textbook in vocational high school math class can be expected in the long term.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.51-59
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• 2019

In this study, the influence of anaerobic digested sludge and 50 mM PBS (phosphate buffer solution) mixing ratio (1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7) on hydrogen production and inoculation period were examined. MECs were operated in fed-batch mode with an applied voltage of 0.9 V. As a result, in the 1:1 mixing ratio reactor, 9.8-20.9 mL of hydrogen was produced with the highest hydrogen content of 66.8-79.6%. Hydrogen gas production and power density increased from after 12 days of inoculation for the 1:1 mixing ratio reactor. In case of 1:2, 1:3 and 1:4 mixing ratio reactor, the hydrogen gas production was 3.7-7.1 mL and the hydrogen gas content was 5.8-65.8%. The hydrogen gas yield in 1:5, 1:6 and 1:7 ratio reactors, was 0.50-0.69 mL and hydrogen content range was 1.8-7.1%. The mixing ratio was found to be suitable for hydrogen production and inoculation period by mixing ratio up to 1:4.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.359-369
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• 2013

In this study, the relationship between social support and adolescent mental health was examined. A primary aim was to investigate how family, school, and friends affect adolescent mental health including depression, stress, and anger issues. This study also intended to investigate the indirect effect of these factors through the mediator, problem drinking. The study used survey data collected from the "2010 The Study on Mental Health of Korean Adolescents" conducted by National Youth Policy Institute, and 942 subjects were selected for this study. The study hypotheses were tested using SEM (Structural Equation Modeling) analysis. Analyses revealed that the appropriate functions and roles of the family members had the effect of promoting mental health of adolescents. Inappropriate functions and roles of the family members induced problem drinking, and this eventually had a negative impact on mental health causing depression, stress, and angel problems. Results also showed that having more friends who drink alcohol or smoke cigarette had no direct effect on the mental health of adolescents; however, there was an indirect effect through the mediator variable, problem drinking. The finding of this study revealed the need and importance of appropriate social support system and environment in order to promote mental health of adolescents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.641-648
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• 2020

This study was undertaken to provide basic data for the development of a mental health promotion intervention program, by confirming the mediating effects of social support in relation to the effect on the life stress and meaning of life in middle-aged women. The subjects of this study were 201 middle-aged women from D and K cities. The data were analyzed with descriptive statistics and Pearson's correlations using a statistical program for structural equation modeling (SEM); fitness of the final model was RMSEA 0.03, CFI 0.98, and NFI 0.95. The major learning from this study was that life stress has a direct effect on meaning of life and social support. Life stress (β=0.05, p< 0.001), meaning of life (β=0.05, p< 0.001), and social support (β=0.05, p< 0.001) have a significant and direct effect on depression. The findings also suggest that life stress indirectly affects the mediating effect between meaning of life and social support, and also depression of middle-aged women. We believe that results of this study encompass basic data that will aid in developing a program to promote the mental health of middle-aged women.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.569-579
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• 2017

The purpose of this study was to test the mediation effects of adolescents' ego-resilience on the relation between neglect, abuse and life satisfaction. The 6-year longitudinal data from the Korean Children & Youth Panel Survey (KCYPS) were collected from 1st grade middle school students. The data were analyzed by structural equation modeling and Sobel testing.The results of this study were as follows. First, the results revealed that the path from neglect and abuse to life satisfaction was partially mediated by family relations. The relations between trauma(neglect) and ego-resilience are negative(${\beta}=-.258$, p<.001). The relations between ego-resilience and life satisfaction are positive(${\beta}=.843$, p<.001). Second, the verification of the mediation effect of ego-resilience showed that ego-resilience was a full mediator between trauma(neglect) and life satisfaction for 1st grade middle school students(Z=-.169, t(CR)=-.012 (p<.05). Based on these results, the practical implications were discussed.

• Journal of KIISE:Software and Applications
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• v.37 no.12
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• pp.892-908
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• 2010

Services in SOA are typically perceived as black-box to service consumers, and can be dynamically evolved at runtime, and run on a number of unknown and heterogeneous environments. Because of these characteristics of the services, effective and efficient monitoring of various aspects on services is an essential functionality for autonomous management of service. But the problem with or limitation in conventional or existing approaches is, that they focus on services themselves, ignoring the effects by business processes. Consequently, there is a room for service monitoring which provides more useful information of business level by acquisition of only external monitoring data that depend on specific BPEL engine and middleware. Moreover, there is a strong demand to present effective methods to reduce monitoring overhead which can degrade quality of services. EDA can cope with such limitations in SOA by collecting and analyzing events efficiently. In this paper, we first describe EDA benefits in service monitoring, and classify monitorring target, and present an appropriate monitoring method for each monitoring target. Also to provide the applicability of our approach, an event meta-model is defined, and event processing model and architecture based on the meta-model are proposed. And, with the proposed architecture and method, we implement a prototype of an event-driven dynamic monitoring framework which can collect and process internal and external data at runtime. Finally, we present the result of a case study to demonstrate the effectiveness and applicability of the proposed approach.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.379-385
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• 2020

This paper presents a design for preventing coolant leaks in the core part of a heater mounted in a combat vehicle. The heater is a device that makes heated coolant flow through the heater core in the crew room. A problem with coolant leaks in the heater core area during the operation of a combat vehicle was identified. This problem is caused mainly by high pressure at the junction of the tank and tube due to the vulnerability of this area. To solve this problem, an improved core was made by improving the welding method and changing the end region of the heater core to a structure that can withstand high pressure. When pressure was applied sequentially to the existing core and improved core, a leak occurred at 7.0 kgf/㎠ in the existing core while the improved core maintained its structure up to 17.0 kgf/㎠, highlighting the improvement. Finally, performance tests and environment tests were conducted to demonstrate the suitability of the improved structure. The improved heater will be applied to combat vehicles. This paper is expected to serve as a reference for improving defense capabilities by securing reliability as well as the design and analysis of failures of similar equipment.nse capabilities through securing reliability as well as the design and analysis of failures of similar equipment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.40-47
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• 2020

Various technologies, systems, and legal systems are applied to prevent and quickly respond to fire disaster; nevertheless, the damages to life and property caused by fires are not reduced every year. For managing fire disaster, generating spatial information-based safety status map and procuring suitability of attribute information for each position information are essential. The safety status map is generated by deriving the fire safety status assessment factors, indexing, and locating the surveying results through various methods. In this paper, we deal with derivation of building fire safety assessment factors for 3D safety status map. At first, we survey the foreign and domestic fire assessment model cases and its factors, and analyze the applicability of Korean 3D fire safety status map. Next, assessment factors for fire safety assessment model are derived. Assessment factors are derived and categorized by their information collecting activity; factors that can be accessed through basic building information and factors that can be accessed through field survey. As a derivation result, 14 assessment factors were derived over five categories(Industry Risk, Structural Risk, Fire Fighting Facility, Fire Dangerousness, Fire Response Status).