• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.683-688
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• 2012

Driver's feeling is variously affected by lots of components such as engine, frame, wheels, and seats during the operation of automobiles. The main objective of this research is to identify the correlation between subjective evaluation and vibration metrics that was set by ISO to investigate development of the car vibration quality index using multiple linear regressions (MLR). A previous research related with automotive vibration quality used the method of calculating acceleration values of the point of a seat, a seat back, foot as RMS for objective evaluation. The automotive comfort is determined by RMS values. In comparison with the previous research, this study includes not only the vibration metrics, but also subjective values by jury evaluation. By indentifying the correlation between subjective evaluation and vibration metrics, the automotive vibration quality index is developed through MLR. Based on the results of this study, the proposed the automotive vibration quality index which developed through MLR will be helpful to obtain objective and reliable automotive comfort values.

• Journal of Power Electronics
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• v.9 no.4
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• pp.553-566
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• 2009

In-phase control and energy-optimized control are the two major control strategies proposed for series power quality controllers (SPQC). However quantitative analysis and comparison between these two control strategies is quite limited in previous publications. In this paper, an extensive quantitative analysis is carried out on these two control strategies through phasor diagram approach, and a detailed quantitative comparison is conducted accordingly. The load current is used as the reference phasor, and this leads to a simpler and clearer phasor diagram for the quantitative relationship. Subsequently detailed analysis of SPQC using in-phase control and energy-optimized control are provided respectively, under different modes both for under voltage/voltage sag and for over voltage/voltage swell. The closed form analytic expressions and the curves describing SPQC compensation characteristics are obtained. The detailed system power flow is figured out for each mode, and the detailed quantitative comparison between the two control strategies is then carried out. The comparison covers several aspects of SPQC, such as required compensating voltage magnitude, required capacity of energy storage component, and maximal ride-through time. In the end, computer simulation and prototype experimental results are shown to verify the validity of all the analysis and the result of the comparison.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.6
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• pp.633-641
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• 2015

The ROM (roll over mitigation) system is a next-generation suspension system that can improve vehicle-driving stability and ride comfort. Currently, mass-produced safety systems, such as ESC (electronic stability control) and ECS (electronic control suspension), enable measurements of longitudinal and lateral acceleration as well as yaw rate through inertial sensor clusters, but they lack direct measurements of the roll angle. Therefore, in this paper, a roll angle estimation algorithm from ESC system sensors and tire normal force has been proposed. Furthermore, this study presents a method for roll over mitigation force distribution between the front and rear of a ROM system. Performance and reliability of the roll angle estimation and roll over mitigation force distribution were investigated through simulations. The simulation results showed that the proposed control algorithm and strategy are reliable during vehicle rollovers.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.854-863
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• 2008

A high attention has been paid on the running safety of Korean high-speed train, KTX. In running of KTX on bridge, the running unsafety problem issued from a resonance phenomenon of bridge, which was usually caused by the periodic wheel-loads of train. Therefore, many researches on this running safety of train on bridge have been conducted by domestic or foreign researchers. In this paper, for PSC box-girder bridge which is the representative high-speed railway bridge type, some numerical analyses on the dynamic characteristics of bridge with the non-periodic wheel-loads through vehicle size adjustment were performed. These numerical analyses shows the fact that the resonance phenomenon on bridge was mitigated through vehicle size adjustment. Additional numerical analyses on the vibration reduction of bridge in accordance with the location of size-adjusted vehicle were performed. From these results, it was represented that the adjustment of vehicle size has an effect on the running safety of train as well as the ride comfort.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.26-37
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• 2019

Recently, standardization of installation progress and technology of site acceptance test(SAT) for energy storage system(ESS) are being required due to performance of ESS depending on working condition and environment even though the quality and safety of each component of ESS　is guaranteed. And also, it has been required to perform not only performance testing by H/W equipments but also performance verification by S/W tool, in order to more accurately and reliably validate the performance of the ESS in advanced countries. Therefore, this paper proposes evaluation algorithm for SAT to evaluate performance of ESS and presents modeling of SAT test equipment for ESS by using PSCAD/EMTDC. Furthermore, 30[kW] scaled portable test equipments is implemented based on the proposed algorithm and modeling. From the various simulation and test results, it is confirmed that performance of ESS related to characteristics of capacity and Round-trip efficiency, Duty-cycle efficiency, low voltage ride through(LVRT) and Anti-islanding can be accurately evaluated and that the simulation results of PSCAD/EMTDC are identical to test results of 30[kW] test equipment.

• The Research Journal of the Costume Culture
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• v.21 no.1
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• pp.66-80
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• 2013

Nomadism means 'divide share' and 'drift where allocated'. The word to express a variety of modern people without being tied to a fixed time and place, constantly moving to new areas and explore the possibility. The progress of this study, first, to research on the conceptual study of Nomadism through Deleuze's theory of art and to organize Nomadism patterns and design paradigms in modern society. Second is to analyze and investigate cases of Nomadism based on the theoretical background in a way to reinterpret to the contemporary fashion, and to suggest the formative characteristics and inherent expressiveness of Nomadism expressed in modern fashion. Theoretical considerations made through the collection data were select from ready-to-wear women's collections 2005 S/S~2013 S/S presented in 'Style.com'. The results of the analysis of the formative characteristics of Nomadism in the $21^{st}$ century fashion are 'mixed expressions of time space and gender', 'pursuit of diversity through self-dismantling', 'clothing systemization of mobile and deformable' and 'temporary amusement, lightness, an expression of the ride rules'. The inherent expressiveness of Nomadism through these types of figurative representation are 'unbounded fashion', 'multi-center, multi-functional' and 'emotional directivity'. As such, philosophy and artistic trends started Nomadism is harmoniously expressed in terms of the design transcending the boundaries of existing stereotypes.

• Korea Trade Review
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• v.48 no.1
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• pp.263-285
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• 2023

The purpose of this study is to examine the business model, growth process, and success factors of the successful super app Gojek in the Southeast Asian and Indonesian markets. Gojek's business model analysis focused on the business canvas (9 blocks) that many companies have used to establish business models. Gojek's growth process was analyzed based on timeline. Gojek 1.0 is from the start of the ride hailing service. Gojek 2.0 is a leap forward into a life-friendly platform. Gojek 3.0 is a process of expanding and diversifying domestic and foreign businesses. Gojek 4.0 is a stage of changing to GoTo through mergers with Tokopedia, and setting a higher leap forward. Based on this, the success factors of Gojek are ① Hyperlocalization ② First mobile ③ A company that is loved through mission execution ④ Provide financial inclusion ⑤ Business expansion and diversification through mergers and acquisitions and partnerships ⑥ Entry into overseas markets ⑦ Attracting various partners and investment ⑧ Lock-in effect and hyperpersonalization. The implications obtained through this study and the limitations and direction of the study were discussed.

• Journal of the Korean Society of School Health
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• v.21 no.1
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• pp.33-41
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• 2008

Purpose : The purpose of this study was to provide the basic data for p lanning oral health education in elementary schol. Methods conducted using a postal, self-administered questionnaire. A questionnaire containing 19 questions about oral health education which was provided by health teachers in elementary schol was used for data colle ction. Total response rate was 64.3% (119 out of 185). Results : Oral health education except one through textbooks was conduc of which taught oral health themselves. The contents of oral he alth education through special clas was mainly focusing on the tothbrushing method, dental caries, and the use of fluo ride. Acording to the grades clasified by the level of education, the order was the 3rd, 1st, and 2nd grade, which mea ns that the lower grades got more training than the h was acquired through the internet (72.2%), health-related organizations or academies (51.5%). Also, materi als for oral health education were obtained from health-related organizations or academies (67%), self-productio n (49.5%). According to the data during the past 5 years it was found that 13.4% health teachers had oral health-related that more traing neded to be conducted from 89.7% health tea chers. The most dificult problem in oral health education were insufficient time (56.7%). Conclusion : For effective oral health education, there needs a developmen t of targeted goal to achieve a systemic oral health education for each grades as wel as a ned for as health teachers to eficiently acquire knowledge and materials for oral health education, it is necessary to hold regular workshops for health teachers, and develop and distribute appro priate educational materials.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2250-2255
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• 2011

There has been a growing interest toward railroad conjunction with opening of high-speed rail in 2004 and concurrent implementation of nation's green growth policies. Meanwhile, users' expectation on service of public transportation, especially railroad has been growing than since ever due to heightened quality of life, entering aging society, voice of equity for minorities, and greater interest in environments of communities. In order to come up with the expectations, actual improvements for user's convenience/comfort and its assessment strategies in terms of service quality level are necessary. This study defines the index of this aspect of service level as 'Sensitivity Quality'. This is conceived as one of the important factors to define travel cost as do the travel time and fare, but hardly taken into consideration when assessing a transportation system or policy-making for a transportation project. The elements included for the assessment of the sensitivity quality in this study are feeling of a ride, conformability and convenience what users feel and recognize using a train. This paper suggests that establishing sensitivity quality elements would contribute in foundation of assessing service quality and provide improved public transportation services through their scientific and objective development and management.

• Journal of the Korean Home Economics Association
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• v.36 no.9
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• pp.13-33
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• 1998

The purpose of this study is to examine the styles of street fashion in youth sub-culture which has the leading power of 1990's Korean fashion flow. This topic has been explored in documentary studies about the youth sub-culture and the background of street fashion. Then, it also continued to classify street fashion styles in order to grasp the meaning as a young fashion. The results of this study are as follows. Street fashio of Korean youth are composed of four styles. ; The first is a hip-hop style. The hip-hop of Korea is started by 'Taiji Boys' and their representative apperances are the big-baggy pants, the reversed cap, the thrown backpack. The second is a reggae style. It is formed by the singer 'Kim Gun Mo'. It features the primary color and the use of ethnic fabrics. The third is a kitch style. The kitch is definitely represented by the old, the childish and the satire appearances. It came up with the rock band 'pipiband'. The forth is a sporty style. It comes from 'basketball' and 'skateboarding' which the young people prefer. Its designs are applied from the back-number of players, the names of the teams, the stripes of active-feeling. Based on this study, I designed cloths with 3 concepts to present a new design direction of Street Fashion. Work 1, 「JOY-RIDE」 represented the freedom and the release which are shown by pop music and dance. Work 2, 「GAMMA ENERGY」 represented the dynamic energy through sports games. Work 3, 「AROUND THE CORNER」 represented the form of street including comers, walls, roads etc.