• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.229-229
• /
• 2007

In this study, HEMA-based hydrophilic copolymers were synthesized and dielectric constant (K) of the polymer thin films were investigated by change hydroxyl group (-OH) ratio in the polymer chain. The different hydroxyl group ratios were characterized by FT-IR and its thin films were obtained by spin coating. As a result, due to the moisture absorption of the hydrophilic thin film, the dielectric constant has been increased as was expected. The highest dielectric constant (K=4.19, @1MHz) was observed at 40% hydroxyl group ratio among the several polymers.

• Polymer(Korea)
• /
• v.31 no.6
• /
• pp.474-478
• /
• 2007

Polymer substrate materials with low dielectric loss were obtained by fabricating the composite using dicyclopentadienyl bisphenol cyanate ester oligomer and polyphenylene ether (PPE). From the analysis of the curing reaction of oligomer and catalyst, it was observed that the optimum amount of catalyst was 0.02 phr of Zn content. It was applied to the fabrication of polymer composite. By changing oligomer/PPE weight ratio, the peel strength and the gel content of the fabricated composites were measured, and then, the dielectric constant and the dissipation factor were measured in the GHz frequency range. The amount of PPE affected the peel strength and the dielectric properties of composites. However, the amount of catalyst did not affect them at all. Resulting from all experiments, we obtained polymer composite laminates haying the peel strength of above 1 kN/m and the low dissipation factor of 0.004 at 1 GHz.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.1
• /
• pp.129-135
• /
• 2013

There is not enough absorption space in the side of a vehicle so injuries to a passenger are higher compared to frontal impact injuries. For the protection of the passenger in the event of a side impact, vehicle regulations and new car assessment program(NCAP) are implemented all over the world. However, passive safety such as absorption technology of vehicle body itself is limited due to the narrow space of the side part. At the present time, it is well known that a side airbag including a curtain airbag is the most effective system to protect the passenger during a side impact. In this study, optimum design of the curtain airbag is carried out to reduce Head Injury Criterion(HIC) of the passenger. Based on crashworthiness simulation, an orthogonal array is selected based on the defined design variables, the response surfaces are generated from the orthogonal array and optimization is conducted with the surfaces.

• Journal of the Korea Society for Simulation
• /
• v.33 no.1
• /
• pp.27-34
• /
• 2024

This study aims to propose an optimal asset allocation that minimizes the risk of insufficient realized replacement rates compared to the OECD average replacement rate. To do this, we set the shortfall risk of replacement rates and calculates an asset allocation plan to minimize this risk based on the period of enrollment, the income level and additional contribution. We consider stocks and deposits as investment assets, using Monte Carlo simulation with a GBM model to generate return distributions for stocks. Our result show that, for individuals with a enrollment period of less than 30 years, participants should invest a minimum of 70-80% of their funds in risky assets to minimize the shortfall risk. However, the proportion of funds that need to be invested in risky assets declines significantly when participants contribute an additional premiums. This effect is particularly pronounced among low-income individuals. Therefore, to achieve OECD average replacement rates, the government needs to incentivize participants to invest more in risky assets, while also providing policies to encourage additional contributions, especially for the low-income population.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.17 no.2
• /
• pp.115-128
• /
• 2022

This research aims to analyze of the Effect of Army Start-up Support Program (hereinafter, ASSP) on the level of discharged or scheduled to be discharged soldier's satisfaction of their military service. In addition, this paper also seeks to elaborate on how those Army-supported programs, such as Start-up competitions, mentoring, camp, and school, can increase the level of military service satisfaction. By participating in those programs, service members can leverage their time in the military to make opportunity for their future career rather than consider it as a career break, increasing their military service satisfaction. Finally, on the basis of findings, this paper advocates for expanding Service Members startup Support Program of government agencies and municipalities and enhancing younger population's individual capabilities through ASSP. This research used ASSPs, such as Army Start-up competitions, mentoring, camp, and school, as independent variables. For controlled variables, this paper takes demographic elements such as status and career path of the participants. Our empirical analysis reveals that ASSP has a direct impact on the military service satisfaction, supported by the statistics from the hierarchical regression analysis. However, the research also suggests that individual' military service satisfaction from ASSP may differ from one another in accordance with the controlled variables such as status and career of the participants. This paper proves that ASSP can play a substantial role in enhancing service members' capabilities during their time in military and that Army fosters talent and connects itself to the nation and society. In addition, this research could contribute to increasing employment rate of and expanding Start-up support program of government agencies and municipalities for younger population by providing empirical results which advocates the latter's necessity.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.1
• /
• pp.36-45
• /
• 2014

Pedestrian to vehicle traffic accidents show a very high mortality rate compared to the frequency of occurrence. In order to improve the pedestrian protection performance of the vehicle, the korean government added a "pedestrian safety" entry from the year 2007. The performance for pedestrian protection of current vehicles gradually improved compared to the past, but it is still insufficient. It was found that the pedestrian protection performance was very weak, such as the top of the bonnet, the A-pillar and under the front windshield. A application of an active hood and pedestrian protection airbags can be countermeasures for these weak points of pedestrian safety. The active hood and pedestrian protection airbags are designed and manufactured to apply to the top of the hood and to the bottom of the windshield. The manufactured system is equipped in a test vehicle and evaluated based on the Korea New Car Assessment Program(KNCAP) test procedures for the performance of pedestrian safety. As a result, the outstanding effect of pedestrian protection has been achieved by the active hood and the pedestrian protection airbag. The rates of pedestrian injury are reduced by 82.2% and 95.4%, respectively.

• Journal of the Korean Arthroscopy Society
• /
• v.14 no.1
• /
• pp.36-40
• /
• 2010

Autologous chondrocyte implantation is a widely used technique for treating cartilage defect or osteochondral lesion, which is the method of transplantation of self chondrocytes after cultivation in the laboratory. We experienced the rare case of heterotophic ossification in the recipient site of the knee after autologous chondrocyte implantation. So we want to report this case with review of the relevant literatures.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.54 no.3
• /
• pp.265-269
• /
• 2009

Technology development for sufficient dry matter production of Chinese milk vetch (CMV) is most important in CMV-rice cultivation system in order to provide sufficient nutrients to rice plants. However, when the CMV plants are dominated by the weed, especially Alopecurus aequalis, the CMV growth could be reduced due to light and nutrient competition. In addition, A. aequalis is potential host of the rice dwarf virus disease. Therefore, control of A. aequalis is necessary to enhance the biomass production of CMV plants when CMV stands are insufficient. The use of chemical like sethoxydim (20%, ai) showed the highest control rate of 84% at early stage and was reduced as application was delayed. A. aequalis control did not change the CMV seedling stand before and after herbicide treatment and the reseeding stand in fall was rather increased 2.2 to 2.6 times. On the other hand, in untreated control, the CMV stand at May 15 and reseeding stand in fall was significantly reduced as compared with the before herbicide treatment. Control of A. aequalis increased the CMV dry matter production by 164% for 50% CMV coverage rate and 63% for 25% CMV coverage rate. This is equivalent to $12.3{\sim}16.4\;kgN$/10a which is greater than the recommended nitrogen rate of 9kg/10a. The result indicates that the control of A. aequalis is an efficient way to enhance dry matter production in CMV-rice cultivation system especially when CMV stand is poor.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.6B
• /
• pp.342-349
• /
• 2007

Clustering protocol of Wireless sensor networks(WSNs) not only reducing the volume of inter-node communication by the nodes's data aggreation but also extending the nodes's sleep times by cluster head's TDMA-schedule coordination. In order to extend network lifetime of WSNs, we propose ECS algorithm to select cluster-head using three variables. It consists of initial and current energy of nodes, round information and total numbers which have been selected as cluster head until current round.

• The Journal of the Korea Contents Association
• /
• v.4 no.3
• /
• pp.1-11
• /
• 2004

This study alms to perform Business Process Reengineering and to develop tourism statistics information system through the development of tourism statistics process design supporting tool. With this tool, we can manage tourism statistics systematic and integrated. Also it offers a tourism decision making supporting tool. Tourism statistics process design supporting tool consists of information provider, information maker, and information user. This tool can improve bossiness process, and rationalize system architecture. 49 business processes were designed and a database which connected with outside system was designed by this supporting tool. By these means, this tool provide more reasonable and effective decision making tool, when it comes to plan tourism development.