• Title/Summary/Keyword: 탈출

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Low Thrust, Fuel Optimal Earth Escape Trajectories Design (저추력기를 이용한 연료 최적의 지구탈출 궤적 설계 연구)

  • Lee, Dong-Hun;Bang, Hyo-Choong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.7
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    • pp.647-654
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    • 2007
  • A Discrete continuation Method/homotopy approaches are studied for energy/fuel optimal low thrust Earth escape trajectory by solving a two point boundary value problem(TPBVP). Recently, maneuvers using low thrust propulsion system have been identified as emerging technologies. The low thruster is considered as the main actuator for orbit maneuvers. The cost function consists of a energy/fuel consumption function, and constraints are position and velocity vectors at the terminal escape point. Solving the minimum energy/fuel problem directly is not an easy task, so we adopt the homotopy analysis. Using a solution of the minimum energy, which is solved by discrete continuation method, we obtain the solution of the minimum fuel problem.

실직근로자의 직업탐색과 재취업-광주지역 근로자를 중심으로-

  • 홍성우;양채열
    • Journal of Labour Economics
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    • v.22 no.1
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    • pp.1-29
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    • 1999
  • 한국은 지난 1960년대 이후 실업률이 추세적으로 하락하여왔기 때문에 실업구조, 직업탐색에 대한 관심이 비교적 적었으나 최근의 고 실업률은 이에 대한 연구의 필요성을 제고시키고 있다. 기존의 연구들은 저 실업률 시기의 자료를 사용한 것이므로 1998년의 고 실업률 자료를 활용한 연구는 다른 연구결과를 가져올 것이다. 이 글은 고 실업률 시기로 진입한 지 1년이 되는 98년 11월말 광주광역시에서 실시된 상시고 실직자에 대한 설문조사자료를 이용하여 고 실업률 시기의 실직자의 직업탐색과 실업기간을 분석하였다. 본 연구결과는 기존의 연구결과와 많은 부분에서 일치하지만 한국에서 대량실업은 처음 겪는 상황이므로 이전의 연구결과와 다르거나 새로 확인된 사실들도 몇 가지 있다. 연구결과를 요약 정리하면 다음과 같다. 첫째, 비자발적 이유에 의한 실직자가 약 70%를 차지하고 구인배율이 아주 낮아 최근의 실업은 수요부족에서 발생한 것이라고 할 수 있다. 따라서 임금을 낮추고 희망하지 않는 직종 산업 종사상 지위로 하향 구직을 하고 있었다. 둘째, 고실업률이 장기화되면서 나타난 현상으로는 구직경로가 다양해졌고, 유보 임금 및 수락임금이 전직임금보다 약 20% 하락함으로써 임금이 신축적임을 보여 주었다. 그러나 고실업 사태를 급작스럽게 맞이하면서 이전임금에 대한 집착이 강하여 하락폭은 충분히 신축적이었다고 보기는 어렵다. 셋째, 실업보험수급자는 유보임금 하락률이 높았고 실업 탈출률도 높았다. 이것은 직업탐색이론과 상반된 결과로 노동수요부족사태를 처음 겪으면서 노동시장에 대한 정보가 모든 실업자에게 동일하지 않고, 실업보험수급자가 보다 완전한 정보를 가지고 있으며, 실업보험지급에 따른 구직독려 때문인 것으로 생각된다. 넷째, 기존 연구들과 마찬가지로 유보임금은 전직 임금에 크게 의존하였으며 실업기간에 대한 해자드 분석에 의하면 유보임금의 대리변수인 전직임금이 낮을수록, 구직을 적극적으로 할수록 탈출률일 높았다. 인적속성으로는 인적자본축적이 많고 다양한 취업정보를 접할 수 있는 고학력자의 탈출률이 높았다. 다른 나라에 대한 기존 연구의 근속기간이 긴 남성 실업자는 실업기간이 길었지만 여기서는 반대의 결과가 나왔다. 그것은 기업의 도산 등에 따른 실직자의 경우 유용한 인적자본 보유자가 많고 축적된 자산으로 자영업으로 탈출할 확률이 높기 때문인 것으로 해석된다.

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Arthroscopic Evaluation of Graft Extrusion after Lateral Meniscal Allograft Transplantation - A Case Report - (외측 반월상 연골 이식술 후 이식물 탈출의 관절경적 평가 -증례 보고-)

  • Kim, Hee-Chun;Kim, Taik-Sun;Kim, Young-Bae;Yang, Jai-Hyuk;Kim, Jin-Kak;Yoon, Jung-Ro
    • Journal of the Korean Arthroscopy Society
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    • v.17 no.1
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    • pp.76-78
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    • 2013
  • The meniscus is considered "extruded" when it extends beyond the tibial margins more than 3 mm in a coronal view of magnetic resonance imaging (MRI). However, identifying the meniscal extrusion intraoperatively may be difficult because of the simple fact that most of the arthroscopic procedures are done in knee flexion position while follow up MRI studies area taken at knee extension position. Here, we demonstrate the arthroscopic technique for evaluating the meniscal extrusion.

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Passenger Ship Evacuation Simulation using Algorithm for Determination of Evacuating Direction based on Walking Direction Potential Function (보행 방향 포텐셜 함수 기반의 탈출 경로 결정 알고리즘을 이용한 여객선 승객 탈출 시뮬레이션)

  • Ha, Sol;Cho, Yoon-Ok;Ku, Namkug;Park, Kwangphil;Lee, Kyu-Yeul;Roh, Myung-Il
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.5
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    • pp.307-313
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    • 2013
  • This paper presents a simulation for passenger ship evacuation considering determination of evacuating direction based on walking direction potential function. In order to determine walking direction of a passenger, his/her position in two dimensional plane was adopted as a design variable, and fixed boundaries such as walls and obstacles were adopted as constraints. To solve this optimum problem, a walking direction potential function was adopted as an objective function. This potential function was configured as a kind of penalty function and it contained two components. One is a potential function concerned with the distance to the destination, and other is a potential function based on the effect of walls and obstacles. To determine evacuating direction, this problem was solved by minimizing the walking direction potential function every unit time during the simulation. The crowd behavior of the passenger consisted of the flock behavior, a form of collective behavior of a large number of interacting passengers with a common group. With the proposed algorithm, the test problems in International Maritime Organization, Maritime Safety Committee/Circulation 1238(IMO MSC/Circ.1238) were implemented and the direction of passengers and total evacuation time was analyzed.

Effect of whole body cryotherapy with spinal decompression on lumbar disc herniation by functional assessment measures (기능적 평가 측정을 통하여 전신냉기치료와 척추 감압기 적용이 요추 추간판 탈출증 환자에게 미치는 효과)

  • Ma, Sang-Yeol
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.6
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    • pp.1101-1108
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    • 2010
  • This study was conducted to investigate whether whole body cryotherapy and spinal decompression have effectiveness on the pain, lumbar flexion range of motion, and global perceived effect scale in patients with lumbar disc herniation. Thirty subjects were participated in this study. And they were all randomly divided into whole body cryotherapy and spinal decompression group. To evaluate the effects of whole body cryotherapy and spinal decompression, subjects were evaluated by using visual analogue scale, lumbar flexion range of motion, and global perceived effect scale. The assessment parameters were evaluated before, after 2 weeks treatments. And we received a consent form whole body cryotherapy subjects. The results of paired t-test, independent t-test, and ANCOVA analysis of variance showed that pain, lumbar flexion range of motion, global perceived effect scale were significantly improved after than before therapy in whole body cryotherapy group. So we conclude that whole body cryotherapy has effectiveness on the pain, lumbar flexion range of motion, and global perceived effect scale in patients with lumbar disc herniation.

Development of Escape and Rescue Path-taking Method for Plant Accident Response Training (플랜트 사고 대응 훈련을 위한 탈출 및 조치 경로 설계 기법 개발)

  • Kim, Hyoung Jean;Park, Chan-Cook;Lee, Jae Yong;Lee, Chun Sik
    • Journal of the Korean Institute of Gas
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    • v.21 no.6
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    • pp.61-69
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    • 2017
  • In case of plant accident, the most important measures that field operators, control-room operators and fire fighters must take are the escape from and going into the accident sites. These two different actions are reverse directional moving actions. By training operators and fire fighters with counter-accident path taking measurements, we can prevent the small accidents from becoming large-scale accidents, and can take efficient measurements in case of actual plant accidents. Out of necessities of path-taking training, in this research, we developed the escape and rescue path-taking method for plant accident response training. We can calculate the escape and rescue routes from a operator or fire fighter's current location as of accident happening and provide route data which in turn can be used as the safety training scenario. We expect this path-taking method can enhance the effectiveness and reality of escape and rescue training scenarios.

Hemilaminectomy for Herniated Discs at the Cervicothoracic Junction in a Beagle Dog (편측추궁절제술을 이용한 비글견의 경흉연접부 추간판 탈출증의 치료)

  • Kang, Byung-Jae;Kweon, Oh-Kyeong
    • Journal of Veterinary Clinics
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    • v.31 no.6
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    • pp.511-514
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    • 2014
  • A 7-year-old, female Beagle dog presented with a primary complaint of severe neck pain and paretic gait. A lesion was suspected between C6 and T2 on the basis of neurological examinations. Magnetic resonance imaging of the cervicothoracic spine revealed herniation of disc material from the C7-T1 intervertebral space resulting in marked spinal cord compression. Hemilaminectomy was performed to treat the intervertebral disc disease at C7-T1. Treatment was effective and the clinical condition of the dog was remarkably improved. This result suggests that hemilaminectomy is an effective option for surgical treatment of intervertebral disc disease at the cervicothoracic junction in dogs.

Left Diaphragmatic Eventration Diagnosed as Congenital Diaphragmatic Hernia by Prenatal Sonography (선천성 횡격막 헤르니아로 오인된 좌측 횡격막 내장탈출 2예)

  • Yeom, Jung-Sook;Park, Ji-Sook;Park, Eun-Sil;Seo, Ji-Hyun;Lim, Jae-Young;Park, Chan-Hoo;Woo, Hyang-Ok;Jung, Eun-Jung;Jo, Jae-Min;Youn, Hee-Shang
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.9 no.1
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    • pp.92-97
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    • 2006
  • Congenital diaphragmatic eventration is the abnormal elevation of the diaphragm into the thoracic cavity. Sometimes, it is not easy to differentiate congenital diaphragmatic eventration from diaphragmatic hernia by either prenatal sonography or postnatal chest radiography. However, differential diagnosis of both diseases is practical because of different prognosis and surgical approaches. Careful interpretation of postnatal serial chest X-rays is mandatory to differentiate between both diseases. We report two neonates with congenital diaphragmatic eventration of left diaphragm that initially misdiagnosed as diaphragmatic hernia by prenatal sonography and postnatal chest radiography.

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