• Title/Summary/Keyword: Korean Republic

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Wind Tunnel Test for the Inflation Characteristics of the Korean Low Cost Low Altitude Aerial Delivery System (한국형 저비용 저고도 공중보급 체계용 낙하산 전개 특성 풍동시험)

  • Kim, Seung Pil;Jung, Insik;Kwon, Kybeom;Choi, Younseok;Chung, Hyoungseog
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.3
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    • pp.345-351
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    • 2017
  • A wind tunnel test for the scaled parachute models was performed to verify aerodynamic characteristics for practical usage of Korean low cost low altitude aerial delivery system. The cruciform shaped cargo parachute models for heavy and light weight were ejected into wind tunnel test section; and the drag forces acting on the models in steady condition were measured in accordance with velocity. Also, the maximum opening forces during inflation were obtained and captured by a high speed camera to analyze the inflation characteristics and evaluate the design of the low cost aerial delivery system. The results showed a reliable stability and met the design requirement of delivery operation system for R.O.K Air Force.

An Historical Reconsideration of Korean Presidential Security Service during the 1st and 2nd Republic: Focused on the Chief of the Presidential Security, the Law of Presidential Security Special Order, Presidential Security Organization (제1⋅2공화국 대통령 경호의 역사적 재조명: 경호책임자, 대통령경호특별수칙, 대통령경호대를 중심으로)

  • Kim, Eun-Jung
    • Korean Security Journal
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    • no.47
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    • pp.37-59
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    • 2016
  • The purpose of this study is to investigate about security service history during the 1st and 2nd Republic. The 3rd Republic, one of the important periods, deserves special emphasis until now. But Compared with 1st and 2nd Republic, the 3rd Republic is inferior. Although security service history excluded the 1st and 2nd Republic. This research focused on the two points about the chief of the presidential security and the law of presidential security special order. Firstly, the chiefs of the presidential security in 1st Republic were Kim, Jang-Heung Seo, Jung-Hak Kim, Kuk-Jin Kwak, Young-Joo. Secondly, The law of presidential security special order be specified in Korean presidential security for the first time. Before the 1st Republic already recognized the importance of security services when they adopted the first security service regulations on December 29, 1949, which comprised 25 articles. But this law was only focused on presidential security and promulgated the law more than 10 years ago than law of the office of the Presidential Security in 1963. Deplorable in this law was declared by statute on July 7, 1953 from the 1st Republic, but repealed in 1960 after the 2nd Republic. Thirdly, 2nd Republic established the presidential security organization with the new government has been formed. In spite of this organization can not be kept for a long time, 2nd Republic attempted to professional forms of presidential security organization. The research of secret service history must continue to advance for academical learning.

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Tensile stress regulation of NGF and NT3 in human dermal fibroblast

  • Kim, Mi-Na;Hong, Jung-Woo;Nho, Min-Soo;Na, Yong-Joo;Shin, Jennifer Hyun-Jong
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1585-1587
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    • 2008
  • Fibroblast is constantly subjected to mechanical loads in connective tissues where mechanical signals are converted to intercellular biochemical events. The aim of this study is to understand the effects of tensile stress on the neurotrophin (NT) and transforming growth factor (TGF) expression of fibroblast in vitro. Nerve growth factor (NGF) stimulates fibroblast migration, and TGF is related to tissue repair. In this study, at the uniaxial stretch of 10% strain and frequency of 0.5 Hz, different resting times of 0, 20, and 60 min are placed in between 10 min stimulations periods. Results show increase in NGF mRNA levels and a substantial decrease in NT3 mRNA after 1 hr of stimulation, indicating that the tensile stress may regulate NGF and NT3, key factors for the neurocosmetic applications. The mRNA level for TGF-${\alpha}$ and TGF-${\beta}2$ had increased up to two-folds after 1 hr of stimulation, showing that the tensile stress may control TGF, an important part of wound healing.

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Store Separation Analysis of a Fighter Aircraft's External Fuel Tank

  • Cho, Hwan-Kee;Kang, Chi-Hang;Jang, Young-Il;Lee, Sang-Hyun;Kim, Kwang-Yeon
    • International Journal of Aeronautical and Space Sciences
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    • v.11 no.4
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    • pp.345-350
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    • 2010
  • The repetitive vibrating action of an aerodynamic load causes an external fuel tank's horizontal fin to experience a shorter life cycle than its originally predicted one. Store separation analysis is needed to redesign the fin of an external fuel tank. In this research, free-drop tests were conducted using 15% scaled models in a subsonic wind tunnel in order to analyze the store separation characteristics of an external fuel tank. The store separation trajectory based on grid tests was also obtained to verify the results of the free-drop tests. The results acquired from the free-drop tests correlated well with the grid tests in regards to the trajectories and behavior of the stores separated from the aircraft. This agreement was especially noted in the early stages of the store separation.

First record of four bee (Hymenoptera: Apidae) associated mite species (Acari) from Democratic People's Republic of Korea

  • Kontschan, Jeno;Jeon, Mi Jeong;Hwang, Jeong Mi;Seo, Hong Yul
    • Journal of Species Research
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    • v.5 no.1
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    • pp.27-30
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    • 2016
  • Four mite species (Acari: Scutacaridae: Scutacarus acarorum (Goeze, 1780), Chaetodactylidae: Sennertia alfkeni (Oudemans, 1900); Ascidae: Proctolaelaps longanalis (Westerboer, 1963), Laelapidae: Hypoaspis (Pneumolaelaps) marginepilosa (Sellnick, 1938) are found on the body of bees deposited in the Hungarian Natural History Museum, Budapest. The host bee species were collect in Democratic People's Republic of Korea; the found four species are collected at first time in Democratic People's Republic of Korea.

Case study on the utilization of women in the Ukrainian military

  • Jong-Hoon Kim;Sang-Keun Cho;Eui-Chul Shin;In-Chan Kim;Myung-Sook Hong;Sung-Hu Kang;Sang-Hyuk Park
    • International Journal of Advanced Culture Technology
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    • v.11 no.1
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    • pp.153-158
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    • 2023
  • Experts are concerned about the lack of troops and security vacuum due to the low birth rate in the Republic of Korea. They consider policies to expand the proportion and role of female soldiers to address these issues. In this regard, We would like to introduce the successful use of female personnel in the Ukrainian military and draw implications for the Korean military. This will provide a clue to offset the shortage of troops in the Republic of Korea.

Observations of the Mating Behavior and Larvae Habitat of Polyphylla laticollis manchurica in the Republic of Korea (Coleoptera: Scarabaeidae: Melolonthinae)

  • Jaeha Lee;Sang-Bong Son;Sang Woo Jung;Yoon-Ho Kim
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.3
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    • pp.131-133
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    • 2023
  • Polyphylla laticollis manchurica Semenov, 1900, is a critically endangered species in the Republic of Korea and is strictly protected as a Class I endangered species. Although this beetle species faces a threat of extinction, its ecological understanding is limited. Previous studies conducted on this species in the Republic of Korea have focused only on its taxonomy and mitochondrial genome sequences. Herein, we report an observation of the mating of adults of P. l. manchurica in June 2021, during an ongoing study on Korean beetles. This incidence was reported around light sources from newly constructed townhouses near Geumgang River. Larval habitats were observed along the river between April 2022 and March 2023. Particularly, two larvae were found inside the plant debris, and three were found under the roots of reeds. This study provides key information on the mating ecology of P. l. manchurica that can assist conservation efforts of this critically endangered species.