• Title/Summary/Keyword: jungsun

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Parameter Study of Buckling Behavior for Isogrid Structure (등방성격자 구조의 좌굴거동에 대한 매개변수 분석)

  • Kang, Kyunghan;Kim, Yongha;Park, Jinho;Kim, Hyunduk;Park, Jungsun
    • Journal of Aerospace System Engineering
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    • v.7 no.2
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    • pp.8-14
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    • 2013
  • When launch vehicles are manufactured, one of the key points is a design of lightweight structure for reducing costs. Isogrid structure was designed to solve this topic, and many researches were carried out about buckling load because compression load is mainly applied to them. Recently, many studies are also being carried out about FEM model geometry of isogrid structure. The reason is that isogrid structure depends on size of ribs so it is difficult to modify about small changes in rib pattern. In this study, 1/8 model of cylindrical isogrid structure model was developed to analyze buckling behavior. Through parameter study, buckling analysis were performed to analyze buckling load and buckling mode depending on size of ribs.

A Study on the Systematic Crashworthiness Design Concept (체계적인 헬리콥터 내추락성 설계개념 연구)

  • Hwang, Jungsun;Jung, Jae-Kwon;Hyun, Young-O
    • Journal of Aerospace System Engineering
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    • v.7 no.2
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    • pp.35-41
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    • 2013
  • Crashworthiness design concept in the helicopter development is still under evolutionary stage. Survivability in the event of a crash was remarkably improved and this fact can be recognized by the analysis results on the AH-64 Apache and UH-60 Black Hawk crash accidents. Those two models are the first ones in which the crashworthiness design concept was applied with a full-scale requirement. Here we need to notice that under-design of the system results in unexpected injuries and deaths while over-design of the crashworthy elements result in unnecessary weight and costs. If landing gear system would be verified to have enough energy absorption capability in the specified vertical velocity interval, then design requirements of the airframe, fuel system and seats could be modified positively. In this paper, the right and systematic crashworthiness design concept is reviewed on the assumption that design requirements of some crashworthy elements could be partially tailored.

Individual differences in the reduction degree of the Korean suffix 'nɨn'

  • Kim, Jungsun
    • Phonetics and Speech Sciences
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    • v.12 no.2
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    • pp.9-16
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    • 2020
  • The present study examines the degree of suffix reduction that occurs when the Korean suffix [-nɨn] was attached to the root in spontaneous Seoul Korean speech. Specifically, it focuses on the degrees of reduction produced by individual speakers. The degree of reduction was assessed as the duration of the suffix [-nɨn] to clarify the continuum between the full and reduced forms. The results revealed that, first, the reduced forms of the suffix [-nɨn] were significantly distinguished from the full forms in the suffixation processes. Second, regarding parts of speech, the differences among individual speakers on the degrees of reduction were clearer when the suffix [-nɨn] was attached to verbs, rather than nouns and pronouns. Finally, the length of a root played a critical role in determining the degree of reduction of the suffix [-nɨn]. The degrees of reduction for individual speakers significantly differed when the suffix [-nɨn] was attached to two-syllable roots than three- and four-syllable roots. In conclusion, individual differences in the degrees of reduction were likely to occur when the roots are verbs and when two-syllable roots.

Web Services-based Distributed Image Retrieval Framework Architecture Using Ontology (Ontology를 이용한 Web Services 기반 분산 이미지 검색 프레임워크 Architecture)

  • Yang Myoungmi;Jeong Byunghun;Son Youngsu;Kim Jungsun
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07b
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    • pp.688-690
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    • 2005
  • Ontology를 이용한 대부분의 이미지 검색 시스템들은 중앙 집중적(Centralization)으로 구성되어 있어, 단일 이미지 제공자의 특정 지식기반의 이미지 검색을 제공한다. 이에 반해 메타데이터 기반의 분산 이미지 검색 시스템들은 이미지 제공자들의 자율성을 보장하기 용의하지만, 지식기반 이미지 검색을 제공하지 못한다. 본 논문은 위 시스템들의 단정들을 극복하기 위해 Web Services를 이용하여 다양한 이미지 제공자들의 자율성을 보장하면서, 지식기반 이미지 검색을 지원하는 프레임워크의 Architecture를 제안한다.

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A Study on Proper Procedure for Helicopter Transmission Endurance Test (적절한 헬기 트랜스미션 내구도 시험절차 연구)

  • Lee, Sangmok;Hwang, Jungsun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.6
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    • pp.771-778
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    • 2013
  • Transmission is a core component of helicopter to transmit power from engine to rotor and must have a endurance to be able to show satisfactorily its performance required during its life time. When developing a new helicopter, both military and civil airworthiness authorities require a tie-down test to verify its endurance. Procedure for transmission endurance test is described in FAR part 29 or US military specification but its details are more or less ambiguous. In this paper, we have proposed a proper procedure for transmission endurance test by giving KUH transmission endurance test example including determination of applicable torque, load and test profile.

Effect of Discharge Systems on the Transport of Suspended Sediment Particles (방류형태에 따른 부유사 거동 특성)

  • Oh, Jungsun;Choi, Sung-Uk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.59-62
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    • 2015
  • 하천에서 유사이동 분석이 중요한 이유는, 지속가능한 하천관리의 관점에서 하도, 구조물, 생물 서식처와 수질에 이르기까지 하천 내 유사이동이 미치는 영향이 광범위하기 때문이다. 특히, 유사가 어느 지점에서 유실되며 어느 지점에 쌓이는지와 같은 이슈는 하천 지속가능한 관리를 위한 핵심이라 해도 과언이 아니다. 상대적으로 크기가 작은 부유사 입자의 이동은 일상적인 하천의 흐름에서도 대부분 관찰되기 때문에, 그 이동패턴을 파악하는 것이 하천의 효율적 관리에 밑바탕이 된다. 기존연구들에서 주로 연구되었던 부유사 농도 또는 플럭스 산정은 유사에 의한 영향을 파악하기 위한 좋은 지표임은 분명하지만, 유사 입자가 움직이기 시작하는 지점이나 침전하는 지점 등 공간적 분석을 위해서는 입자의 움직임에 초점을 맞춘 분석이 필요하다. 따라서 본 연구에서는 부유사 입자를 추적하는 모의 방법을 이용하여, 개수로에서 부유사 입자를 방류하는 형태가 바뀌었을 때, 입자의 공간적 분포가 어떤 식으로 영향을 받는지에 대하여 분석하였다. 모의결과와 실험결과를 비교하여 연구의 접근방법이 부유사 이동의 공간적 분석을 위한 타당한 방법을 검증하였으며, 나아가 실험으로 측정하기 어려운 부유사 이동 패턴을 제시하였다. 입자의 방류 위치나 방류 간격 등 부유사 입자의 분산에 영향을 미치는 요인들 또한 함께 분석하였다.

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The relationship between mothers' knowledge and practice level of cough etiquette and their children's practice level in South Korea

  • Kim, Jungsun;Oh, Sangeun
    • Child Health Nursing Research
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    • v.27 no.4
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    • pp.385-394
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    • 2021
  • Purpose: This study investigated the relationships between mothers' knowledge and practice level of cough etiquette and their children's practice level of cough etiquette as perceived by their mothers. Methods: This study was a descriptive correlational study. The data were collected from 160 mothers with preschoolers attending daycare centers and kindergartens in Gwangju, South Korea using self-reported questionnaires. Results: The correct answer rate for cough etiquette knowledge in mothers was 86.0%, mothers' average practice score was 33.65±4.14, and their children's average practice score was 28.39±4.85 out of 48. The correlation between mothers' cough etiquette knowledge and practice level was not statistically significant. However, mothers' cough etiquette practice was positively correlated with children's cough etiquette level as perceived by mothers (r=.35, p<.001). Conclusion: The development of a systematic cough etiquette education program and measurements for both mothers and children according to their developmental stages is important to effectively prevent respiratory infections.

The imitation patterns of adults and children on f0 intervals in North Kyungsang Korean

  • Kim, Jungsun
    • Phonetics and Speech Sciences
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    • v.11 no.2
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    • pp.23-31
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    • 2019
  • The present study examines whether pitch range variation in North Kyunsang Korean shows a categorical or continuous function. Specifically, the study is focused on the data imitated by adults and children in the North Kyungsang region. To investigate pitch range variation, the log-produced f0 intervals were measured and statistically analyzed. The results of the study are as follows. First, both the adults' and children's imitations were more categorical than continuous, especially for the HL-LH patterns. For the other pitch accent patterns, such as HH-HL and HH-LH, the curves were continuous or flat for most of the speakers. Second, the children's imitations were poorer than those of the adults. That is, the children's imitative responses were shown as more continuous or flat curves than categorical. For the children, the HL-LH pattern showed a categorical function at the midpoint of the curves, though the shifts were not as distinctive as the adults' data. This implies that the imitative responses of children follow the perceptual and productive trace of adults' speech behavior.

Effects of gender, age, and individual speakers on articulation rate in Seoul Korean spontaneous speech

  • Kim, Jungsun
    • Phonetics and Speech Sciences
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    • v.10 no.4
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    • pp.19-29
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    • 2018
  • The present study investigated whether there are differences in articulation rate by gender, age, and individual speakers in a spontaneous speech corpus produced by 40 Seoul Korean speakers. This study measured their articulation rates using a second-per-syllable metric and a syllable-per-second metric. The findings are as follows. First, in spontaneous Seoul Korean speech, there was a gender difference in articulation rates only in age group 10-19, among whom men tended to speak faster than women. Second, individual speakers showed variability in their rates of articulation. The tendency for some speakers to speak faster than others was variable. Finally, there were metric differences in articulation rate. That is, regarding the coefficients of variation, the values of the second-per-syllable metric were much higher than those for the syllable-per-second metric. The articulation rate for the syllable-per-second metric tended to be more distinct among individual speakers. The present results imply that data gathered in a corpus of Seoul Korean spontaneous speech may reflect speaker-specific differences in articulatory movements.