• Journal of Navigation and Port Research
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• v.41 no.1
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• pp.1-8
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• 2017

The estimation of non-linear ship motion is one of the most important issues in recent studies of ship stability. In this paper, bispectral analysis and bicoherence analysis were introduced in order to analyze the non-linear ship motion. In addition to the previously observed non-linear pitching motion in following seas, this study observed the non-linear phase coupling of pitching motion in following & quartering seas, and starboard beam seas. By comparing phase coupling between each frequency quantitatively via the bicoherence analysis, it was confirmed that non-linear phase coupling was much stronger in frequency regions other than the peak frequencies of a power spectrum. Furthermore, it was found out that the results of bicoherence calculation were analagous to each other, although the different normalization methods were applied.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.7-12
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• 2007

Swirl injector with multi-stage tangential entry was analyzed to suppress high-frequency combustion instability in Liquid Rocket Engines. In order to analyze the effect of swirl injector as an acoustic absorber, swirl injector was regarded as a quarter-wave resonator and it's damping capacity is verified in atmospheric temperature. It has a finite mode of vibration and natural frequencies which can be tuned to the natural frequencies of a model combustion chamber. When the targeted injector for each modes is located at anti-node point, the amplitude of modes was decreased. And when the injector of large diameter is mounted, the split of mode which accompanies the decrease of amplitude appeared. From the experimental data, it is proved that if the location of injector mounted is located at an anti-node position of the targeted modes with proper volume, the amplitude of modes is decreased and the split of modes occurs at anti-node point.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.325-330
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• 2006

Integrating processes are frequently encountered in process industries. Generally they are most commonly associated with level control problems. In this paper, tuning formulae of PID controllers for set-point tracking and load disturbance rejection are presented on integrating processes with time delay. In particular, the controller parameters are determined such that performance criteria(IAE, ISE and ITSE) are minimized. Optimal PID parameter sets are obtained by means of a real-coded genetic algorithm(RCGA) and then tuning rules are addressed using obtained PID parameter sets and another RCGA. The performances of the proposed tuning rules are tested on two processes.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.637-643
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• 2019

To verify internal movements of the body, a DICOM file obtained from CT and a Geant4 code were used to simulate lung cancer patients. In addition, the method is applied to measure the movement of tumor when the movement of t he tumor is located inhale and exhale by creating a virtual tumor in the self-produced moving phantom, and to check the distribution of dose in the treatment plan and the accuracy of tumor in PTV for respiratory and lung cancer patients. It was confirmed that 97% or more respiratory control radiation therapy was effective even if the moving area was more than 3cm, in the 40% to 70% range. Dose distribution with respiratory radiation therapy applied to moving targets, measured by film in the actuation phantom, was shown to be within a 3mm margin of error for dose distribution containing 90%. It was confirmed that for actual patient breathing curves, the treatment time may be shorter than that due to the longer expiratory time.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.61-66
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• 2023

In the past, purchasing limited products was nothing more than purchasing expensive luxury goods. However, the current 'Limited product purchase' is not just pay to ability, but the information to purchase the product are important factors. Therefore, this study aims to find out 1) the motivation to purchase limited edition products and 2) the effect of the motivation on the consumer's experience(price, intention to purchase). As a result, five major purchase motives(Conformity, Interest, Scarcity, Finance technology, Desire to concede) were found. Among them 'Interest' had a positive effect on the product purchase price, and 'Conformity' had a negative effect on the product price. Next, 'Interest' and 'Scarcity' had a positively significant effect on intention to purchase. Through this study, we were able to reveal in depth the actual purchase motives of consumers who are currently emerging as the main age group of the new consumption culture, and expect these purchase motives to be actively used in the new market such as resell markets.

• Korea Petroleum Association Journal
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• no.9 s.67
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• pp.9-22
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• 1986

일본 통산성 ㆍ자원에너지청은 금년초 1985년도 석유유통합리화조사 등의 일환으로서 「석유가스개발가능성조사보고서 」를 작성하였다. 유입LPG의 공급원다양화 방안의 하나로 추진되어 온 동조사는 1982년의 동남아시아를 시작으로, 1983년 중남미, 1984년 북미, 카나다지역을 대상으로 실시되었다. 1985년에는 대일본수출이 기대되고 있는 호주와 뉴질랜드를 대상으로 통산성으로부터 조사위탁을 받은 일본LPG협회가 「석유가스개발가능성조사단 」을 결성, 11월 11일부터 27일까지 현지조사를 실시했다. 이 자료는 일본 「석유정책 」지(86.8.5 및 15)에 실린 동보고서를 번역한 것이다. <편집자 주>

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.159-163
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• 2008

현재 우리나라 국토공간자료의 이용은 자료에 대한 낮은 접근성, 분석방법의 일관성 유지의 곤란, 결과의 미공유에 따른 중복작업, 자료의 분산에 따른 즉각적인 의사결정의 지연 등의 문제를 지니고 있다. 이를 위하여 다양한 국토모니터링 정보를 통합, 처리하여 효율적으로 제공하는 시스템 개발이 요구되고 있다. 이 연구에서는 현재까지 구축된 국토모니터링과 관련된 공간정보시스템의 사례를 조사하고, 특성을 정리하여 국토모니터링을 위한 통합된 공간정보시스템이 갖추어야할 내용과 설계전략을 제시하였다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.203-206
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• 2010

운전원 수동조치는 원자력발전소 화재시 발전소 안전정지를 달성하고 유지하기 위하여 절차에 따라 주제어실 이외의 장소에서 취하는 운전원의 행위를 말한다. 화재시 운전원 수동조치는 발전소 정상운전 동안의 조치에 비해 더 긴장된 상태에서 정해진 시간내에 임무를 완수하여야 한다는 점 때문에 조치성공 가능성을 확인하기 위하여는 행위의 타당성과 신뢰성이 입증되어야 한다. 운전원 수동조치의 타당성과 신뢰성은 조치의 가용시간, 환경조건 등 10가지의 인자를 고려한 시간분석, 절차 및 훈련, 이행, 입증의 과정을 거쳐서 검증될 수 있다.

• Journal of Teachers' Pension
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• v.3
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• pp.255-278
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• 2018

본 연구는 사학연금에서 연기연금재도의 도입 필요성을 검토하고 특히 도입 시 적용할 가산율 설정 등 구체적인 도입방안을 제시하고자 하였다. 사학연금에서 연기연금제도는 수급자의 근로유인과 활동적 노년의 진작을 위해서 필요하다. 이는 또한 국민연금과 직역연금이 동조화되고 있는 현 추세와도 일치한다. 이 연구는 또한 국민연금의 연기연금제도를 참고하여 보험수리적 중립성에 입각한 공정가산율을 산출하였다. 이 방식에 따르면 사학연금 연기연금제도의 핵심제도인 공정가산율은 6.2%로 나타났다.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.23-43
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• 2009

This study examined the relativity between school uniform behavior(especially attitude toward school uniform, school uniform satisfaction, school uniform alteration) and attitude toward appearance in the adolescence. From November to December in 2007, 898 middle school and high school students from four schools in Jeollabuk-do Province were analyzed and the influence of relevant variables was understood to gather basic information about the fashion life in the adolescence. This study used SPSS 11.5 for Windows Program to conduct frequency analysis, factor analysis, reliability analysis, ${\chi}^2$-test, t-test, One-way ANOVA, Duncan's multiple comparison test, and Pearson's correlation. The following summarizes the findings of this study: The results of analysing the factors to the response attitude toward uniforms and attitude toward appearance and clothing attitude emerged four dimensions(fashion, symbolism, cleanliness, alternation), three dimensions(needs value conformity toward appearance). In attitude toward uniform, female students were more actively altering their uniforms than male students and middle school students were more sensitive to trends than high school students. However, high school students were more aware of the cleanliness and alteration of uniforms. Overall, most students were not very satisfied with their uniforms (design, color, texture). When students' attitude toward appearance and demographical characteristics were examined, it was found that female students were more aware of desire, value, and conformity in appearances than male students. By age, it was found that high school students were more aware than middle school students. Also, students receiving KRW 30,000 or more for monthly allowance were more aware than others who receive a lower amount between KRW 10,000 and KRW 20,000. Therefore, most students(62.1%) have experiences in altering uniforms. Especially, more female students and more high school students had such experiences. Uniform alteration is more related to attitude to appearance. In other words, students who choose to alter their uniforms are highly aware of desire, value, and conformity toward appearance. Students who are satisfied with all factors regarding attitude toward uniform, except for alteration, did not alter their uniforms that much. In addition, when the relativity between students' attitude toward appearance with uniform was considered, students that are not very satisfied with their uniforms were more aware of desire, value, and conformity toward appearance. In conclusion, it was found that students' attitude toward appearance and school uniform behavior are closely related and their interests in appearance lead to alteration of uniforms, the clothing in which they spend most time of the day. From now on, students' opinions shall be considered when selecting or designing school uniforms.