• Title/Summary/Keyword: 선도표

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Evaluation of Fatigue Life of Electro-Mechanical Actuator for Front Wheel Steering (전륜 조향용 전기식 작동기 피로수명 평가)

  • Young-Cheol Kim;Hyun-gi Kim;Dong-Hyeop Kim;Sang-Woo Kim
    • Journal of Aerospace System Engineering
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    • v.17 no.4
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    • pp.126-132
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    • 2023
  • Recently, the consideration of eco-friendly technology to reduce greenhouse gas is being emphasized in the aviation field. Various studies for applying electro-mechanical actuators that control mechanical linear and rotational movements using electricity as the primary power source are in progress. In this study, the fatigue analysis of the electro-mechanical actuator for the front wheel steering of a single aisle aircraft was carried out. A unit load stress table was constructed for the vulnerable part selected through structural analysis, and the representative stress for each load profile was calculated using the unit load stress table constructed for the vulnerable part. Then, individual profiles of representative stress group were extracted from continuous load profiles by applying the rainflow counting method. The damage of each profile was calculated by applying the S-N diagram. Finally, the total damage in the vulnerable parts was calculated by the linear cumulative damage law, and the fatigue life of the electro-mechanical actuator for the front wheel steering of a single aisle aircraft was evaluated.

Achievement of Excavation of Gwiam(Turtle Rock) and Nakseojae Restoration in Bogil-do Yun,Seondo Wonlim (보길도 윤선도원림(명승 제34호) 낙서재지역 원형복원과 귀암(龜巖) 발굴의 성과)

  • Lee, Won-Ho
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.30 no.3
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    • pp.111-120
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    • 2012
  • This study regards a series of achievement on Wonlim(Garden) Cultural Properties Excavation Project, led by field of landscape architecture. It will mainly describe excavation results of Gwiam(龜巖: Turtle rock) and historical value of it in terms of Nakseojae(樂書齋) restoration in Bogil-do Yun,Seondo Wonlim(Scenic Sites, No.34). Gwiam(Turtle rock) was found 14.6m apart from the north of Nakseojae, and it covered with 10~15m topsoil tilted toward Nakseojae, The size of Gwiam, which was Granite, was 360cm length, 270cm width, 95cm high. The Edge of Gwiam's North west part was of triangular shape forming Turtle head. The back of the Turtle head was form of Tortoise-shell because of wide backboard with both side groove. The southeast part of Gwiam projected was Turtle's tail. This Granite was obvious Turtle shape artificially made, and there are less likely to relocate from place to place. This Turtle-shaped Gwiam is important landmark for Nakseojae, which is one of the four spiritual creatures written in Bogildoji(甫吉島識) and Gosanyugo(孤山遺稿) by Yunwi. According to Bogildoji, it is estimated that Gwiam were on the axis with Soeunbyung(小隱屛), Nakseojae and was buried when Yiguan(Gosan's grandson) reconstructed a building. Also, it was place for enjoying the moon. But, Even after three times excavation in Nakseojae, there was no way to identify further information regarding Gwiam, so it was a matter of mystification. As a result of this study, Gwiam is laid bare to light in at least 260 years, so it is good example for boosting importance of landscape architecture field and restoring Nakseojae. Furthermore, firm base-soil was discovered in 135m high Rock Mass below, so natural ground of Nakseojae can be estimated by this basis. To be conclusion, Preservation Process for Gwiam and Estimation Space through interpretation of four spiritual creatures(四靈) in Gosan's Poetry should be continue.

Development of a Site Productivity Index and Yield Prediction Model for a Tilia amurensis Stand (피나무의 임지생산력지수 및 임분수확모델 개발)

  • Sora Kim;Jongsu Yim;Sunjung Lee;Jungeun Song;Hyelim Lee;Yeongmo Son
    • Journal of Korean Society of Forest Science
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    • v.112 no.2
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    • pp.209-216
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    • 2023
  • This study aimed to use national forest inventory data to develop a forest productivity index and yield prediction model of a Tilia amurensis stand. The site index displaying the forest productivity of the Tilia amurensis stand was developed as a Schumacher model, and the site index classification curve was generated from the model results; its distribution growth in Korea ranged from 8-16. The growth model using age as an independent variable for breast height and height diameter estimation was derived from the Chapman-Richards and Weibull model. The Fitness Indices of the estimation models were 0.32 and 0.11, respectively, which were generally low values, but the estimation-equation residuals were evenly distributed around 0, so we judged that there would be no issue in applying the equation. The stand basal area and site index of the Tilia amurensis stand had the greatest effect on the stand-volume change. These two factors were used to derive the Tilia amurensis stand yield model, and the model's determination coefficient was approximately 94%. After verifying the residual normality of the equation and autocorrelation of the growth factors in the yield model, no particular problems were observed. Finally, the growth and yield models of the Tilia amurensis stand were used to produce the makeshift stand yield table. According to this table, when the Tilia amurensis stand is 70 years old, the estimated stand-volume per hectare would be approximately 208 m3 . It is expected that these study results will be helpful for decision-making of Tilia amurensis stands management, which have high value as a forest resource for honey and timber.

Research Trends of Articles in the Journal of Korean Home Economics Education Association during the Last Decade (2009. 3~2018. 12) (한국가정과교육학회지 게재 논문의 연구동향: 최근 10년간(2009. 3~2018. 12)을 중심으로)

  • Lee, Jeong Gye;Kim, Eun Kyung;Cho, Jaesoon
    • Journal of Korean Home Economics Education Association
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    • v.31 no.2
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    • pp.95-111
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    • 2019
  • The purpose of this study is to analyze the structure and contents of the articles in the Journal of Korean Home Economics Education Association to review the research trends during the last decade since 2009. In total, 354 articles from 10 volumes, 40 journal books, were analyzed. This amount to 42.3% of total articles in the JKHEEA for the past 30 years. The results showed that the number of articles in the journal continuously decreased by approximately 5 articles each year. More than half of articles were co-authored as a joint-research between professors and teachers or graduate students. The numbers of pages, tables, figures, and references vary greatly among of the articles published in the JKHEEA. The reviewers and authors would need to check if the pages, tables/figures, or references are indispensable, especially in case there are extremely large number of them. Even though survey research with students as participants is still the most common types of research among recent articles, its percentage is decreasing and diverse research methods such as the analysis of textbook or curriculum literature are being used. Also, research integrating the pedagogy and educational content, and in turn developing and evaluating educational programs is increasing, which indicates that the journal identity has become better-defined. It is advisable that authors select the key words that are more relevant to the title, purpose, and research questions. It is expected that the journal revises the publication regulations so that the issues discussed in this study may be reflected.

A Study on the Records Management for the National Assembly Members (국회의원 기록관리 방안 연구)

  • Kim, Jang-hwan
    • The Korean Journal of Archival Studies
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    • no.55
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    • pp.39-71
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    • 2018
  • The purpose of this study is to examine the reality of the records management of the National Assembly members and suggest a desirable alternative. Until the Public Records Management Act was enacted in 1999, the level of the records management in the National Assembly was not beyond that of the document management in both the administration and the legislature. Rather, the National Assembly has maintained a records management tradition that systematically manages the minutes and bills since the Constitutional Assembly. After the Act was legislated in 2000, the National Assembly Records Management Regulation was enacted and enforced, and the Archives was established in the form of a subsidiary organ of the Secretariat of the National Assembly, even though its establishment is not obligatory. In addition, for the first time, an archivist was assigned as a records and archives researcher in Korea, whose role is to respond quickly in accordance with the records schedule of the National Assembly, making its service faster than that of the administration. However, the power of the records management of the National Assembly Archives at the time of the Secretariat of the National Assembly was greatly reduced, so the revision of the regulations in accordance with the revised Act in 2007 was not completed until 2011. In the case of the National Assembly, the direct influence of the executive branch was insignificant. As the National Assembly had little direct influence on the administration, it had little positive influence on records management innovation under Roh Moo-Hyun Administration. Even within the National Assembly, the records management observed by its members is insignificant both in practice and in theory. As the National Assembly members are excluded from the Act, there is no legal basis to enforce a records management method upon them. In this study, we analyze the records management problem of the National Assembly members, which mainly concerns the National Assembly records management plan established in the National Archives. Moreover, this study proposes three kinds of records management methods for the National Assembly members, namely, the legislation and revision of regulations, the records management consulting of the National Assembly members, and the transfer of the dataset of administrative information systems and websites.