• 제목/요약/키워드: 대학원

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전송률 제어 채널에서 비대칭 무선 링크 네트워크를 이용한 트래픽 성능 분석 (Traffic Performance Analysis using Asymmetry Wireless Link Network in Transmission Rate Controlled Channels)

  • 정유선;윤영지;신보경;김혜민;박동석;나상동
    • 한국정보통신학회논문지
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    • 제12권8호
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    • pp.1434-1440
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    • 2008
  • 전송률 기반의 흐름 제어 및 정체 제어 메커니즘을 사용하는 무선 네트워크에서 양방향 TCP/IP 연결의 성능을 연구한다. 전송률 기반의 흐름 제어를 이용하여 데이터의 흐름을 원활하게 유지함으로써, TCP 윈도우 흐름 제어에서 나타났던 다양한 유형의 버스트 현상을 제거하거나 완화시키는데 논하고, 대기열에서 전송률 제어 채널을 통해 실행되는 동안 버스트 반응에 의해 TCP ACK 압축 문제가 발생한다. 소스 IP 대기열의 주기적인 버스트 반응을 분석하여, 양방향 트래픽으로 인해 쓰루풋 저하됨으로써 향상된 퍼포먼스와 상황에 적용 가능한 쓰루풋 저하 예측을 나타내어 대기열의 최대값을 성능분석 한다.

학령기 과체중, 비만 아동 중재에 관한 통합적 문헌고찰 (An Integrative Literature Review of Interventions for School-aged Overweight and Obese Children)

  • 조주현;장상윤;금다정;임지희;김정은
    • Perspectives in Nursing Science
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    • 제16권2호
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    • pp.75-83
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    • 2019
  • Purpose: This study aimed to identify the characteristics of an intervention program for school-aged overweight and obese children through an integrated literature review. Methods: We used five databases (MEDLINE [PubMed], CINAHL, Embase, DBpia, and RISS) to search for studies published between January 1, 2013, and April 18, 2018. The studies were reviewed according to specific inclusion and exclusion criteria. Results: Finally, nine studies were selected and classified into three types: school-based, community-based, and home-based. Specific intervention methods were identified, including exercise, diet, exercise and diet, and cognitive behavioral therapy. Conclusion: Most studies have shown the effectiveness of obesity intervention programs. However, the variables, tools, and methods of measuring the effectiveness of intervention varied, making it difficult to compare the intervention studies. Therefore, future studies should develop objective and integrated measurement tools and evaluate the effects with long-term follow-up.

치주염 조직에서 발현이 증가하는 CTGF에 의한 파골세포 생존 증가 (Increased Expression of CTGF in Periodontitis Tissue and Its Role for Enhanced Mature Osteoclast Survival)

  • 한혜연;박종철;유미현;배문경;김형준
    • 대한구강악안면병리학회지
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    • 제41권4호
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    • pp.155-162
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    • 2017
  • Connective tissue growth factor (CTGF, CCN2) is one of the multi-functional secreted proteins which belong to CCN family of cysteine-rich growth factors. CTGF is known to have pivotal roles in embryonic endochondral ossification but its role in relevance to periodontitis is never been determined. To identify new molecular mediators associated with periodontitis-induced bone resorption, we have analyzed publicly available GEO database and found the markedly augmented CTGF mRNA expression in periodontitis gingival tissues. The existence of CTGF significantly enhanced mature osteoclasts survival which accompanied by reduction in TUNEL-positive nuclei and PARP cleavage. These results may provide another line of evidence the CTGF mediated prolonged osteoclast survival and subsequent increased bone resorption in the periodontitis patients.

OSGi 기반의 스마트 홈 시스템 아키텍처 설계 (Design of a Smart Home System Architecture based on OSGi)

  • 손민우;임철호;박병철;신동일;신동규
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2004년도 춘계학술발표대회
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    • pp.857-860
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    • 2004
  • 인터넷 사용인구가 전 국민의 3분의 2가 넘었고, 초고속 인터넷 설치가구가 벌써 1,100만 이상에 이르게 되었다. 점점 더 사람들은 디지털 생활에 익숙해져 가고 있고, 디지털을 떠나서 살아갈 수 없게 되고 있다. 이러한 분위기에 더하여 가정내의 가전기기들도 디지털화 되고 있고, 이것들을 네트워크로 연결하여 원격지에서 제어하는 홈 네트워크 관련 기술들이 현실화 되고 있다. 그러나, 여러 가전회사들이 각자의 미들웨어를 만들고 이것을 이용해서 제품들을 만들고 있다. 따라서 스마트 홈(Smart Home)[1]을 구성하기 위한 여러 가지 미들웨어 제안들이 나오게 되었고, 이것들은 계속 혼재할 것으로 예상되어 실제로 홈 네트워크를 구성하는데 많은 혼란이 예상되고 있다. 본 논문에서는 여러 가지 미들웨어를 통합하는 OSGi(Open Service Gateway Initiative)[2,3]를 기반으로 구성된 스마트 홈 시스템 아키텍처를 제안하여 홈 네트워크 구성에 대한 위험 부담이 적고 신뢰할 수 있는 방법을 제시하고자 한다.

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상피하 종양으로 발견된 십이지장 신경절신경종 1예 (A Case of Duodenal Ganglioneuroma Manifesting as a Subepithelial Tumor)

  • 주동찬;김광하;채철병;이소정;박도윤
    • 대한상부위장관⦁헬리코박터학회지
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    • 제18권4호
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    • pp.271-274
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    • 2018
  • Ganglioneuroma of the gastrointestinal tract is a rare tumor that consists of ganglion cells, nerve fibers, and supporting cells of the enteric nervous system. Ganglioneuromas are usually associated with genetic disorders such as the multiple endocrine neoplasia syndrome or neurofibromatosis. Ganglioneuromas of the gastrointestinal tract predominantly involve the colon and rectum, and reports about duodenal ganglioneuromas are few. Herein, we report a case of duodenal ganglioneuroma treated with endoscopic resection. A 56-year-old female patient visited our hospital because of a subepithelial tumor in the second portion of the duodenum. She had no remarkable medical or family history and revealed no history of genetic disorders. Endoscopic ultrasonography and abdominal computed tomography revealed a tumor located mainly in the submucosal layer, without any regional lymph node involvement. Endoscopic resection of the lesion was performed, and the pathological examination confirmed a duodenal ganglioneuroma.

전완부의 골도분촌법에 관한 연구 (A Study on Bone Proportional Measurement of the Forearm)

  • 민원홍;양제윤;양기영;채한;이병렬
    • Korean Journal of Acupuncture
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    • 제35권4호
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    • pp.226-233
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    • 2018
  • Objectives : The purpose of this study was to establish an accurate and effective method of locating acupoints of the forearm by studying bone proportional measurement. Methods : A total of 60 volunteers, 30 men and 30 women, participated in this study. 7 parts of the body were measured by a soft ruler or digital vernier calipers. The cun of the upper limb was calculated and analyzed. And the results were compared with the standard cun. Results : The bone proportional cun of the forearm based on height and femur was close to 11. It was different from the standard 12.5, 12 or 10. The cun of the forearm by thumb or finger width measurement was different from the standard too. Conclusions : We suggest that locating acupoints of the forearm needs to be done based on 11 cun. The confusion on locating acupoints of the forearm will be reduced by reflecting the result of the actual measurement.

헬리콥터 조종사 양성과정 비행훈련요소와 학습성취도의 상관관계 (The Correlation between Flight Training Factors in Helicopter Pilot Training Course and Learning Achievement)

  • 박철;김상철;탁희석;신승문;최연철
    • 한국항공운항학회지
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    • 제27권3호
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    • pp.45-53
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    • 2019
  • The purpose of this study is to provide a brief overview of the helicopter pilot training system applied to the Army, and to examine what factors positively affect the successful flight training of helicopter pilots. For this purpose, we analyzed the correlations between various factors such as individual characteristics, selection factors, flight aptitude evaluation, theoretical subjects test, and self-life evaluation. As a result, it was found that only the flight experience was influential on the individual characteristics at the beginning of the training course, and the learning achievement represented by the test of theoretical subjects was positively influenced throughout the flight training course. This reaffirms the fact that an individual's high level of motivation or effort influences his flight training performance. These results are expected to be useful indicators for future development of pilot selection system and pilot training system.

2.45GHz 산업용 마그네트론 구동을 위한 2.5kW DC 전원장치 설계 (Design of 2.5kW DC power supply for 2.45GHz industrial magnetron)

  • 김태현;배정수;김신;김도균;김형석;유찬훈;한성태;장성록
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2019년도 전력전자학술대회
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    • pp.251-253
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    • 2019
  • 본 논문은 1.8kW (4.5kV, 450mA)출력의 마그네트론을 구동하기 위한 2.5kW (5kV, 0.5A) 고전압 DC 전원장치 설계에 대해 기술한다. 무선 전력 전송을 위한 위상배열 시스템에 이용되는 마그네트론의 경우 인가되는 전압의 리플 최소화는 필수적이다. 본 논문에서는 소프트 스위칭을 기반으로한 400kHz 이상의 스위칭 주파수로 컨버터를 설계함으로써 출력리플을 저감하고 필터성분을 최소화 하여 전력밀도를 높일 수 있도록 한다. 변압기의 누설인덕턴스 만을 이용하여 공진 인덕터를 구현하고 변압기의 기생 커패시터 성분과 직렬로 스택킹 된 출력 정류 다이오드의 전압 밸런싱을 위한 커패시터를 병렬 공진 커패시터로 활용한 LCC 공진형 컨버터 고밀도 설계에 대하여 기술한다. 또한, 공진전류의 Trapezoidal 해석 및 설계를 통해 도전 손실을 줄일 수 있는 LCC공진형 컨버터 기반의 마그네트론 구동전원 설계에 대하여 상세 기술하고 PSpice를 이용한 Simulation 및 실험 결과를 통하여 개발된 전원의 우수성을 검증한다.

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실용적인 디지털 임플란트 치료 프로토콜 제안 : 증례보고 (Proposal of practical digital implant treatment protocol : A case report)

  • 양홍서;박상원;임현필;윤귀덕;박찬;이도연
    • 대한치과의사협회지
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    • 제57권9호
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    • pp.529-533
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    • 2019
  • Recently, an advanced workflow has been introduced to finish implant surgery and prosthetic treatment in one-day. However, Because of 1. Patient's physical condition, 2. Surgical technique, 3. Digital technical limitations, the complete completion of one-day implant treatment is practically difficult. Therefore, this paper proposes a "two-days implant digital workflow" that short-time implant surgery and restores prosthetics the next day. Even though it takes more than one day, this workflow is a realistic implant treatment protocol that can reduce the chair time in the clinic.

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압전 에너지 하베스팅을 이용한 신발용 발열 시스템 개발 (Development of Shoe-heating System based on Piezoelectric Energy Harvesting)

  • 이승진;이상웅;신희근;김기만;최성대
    • 한국기계가공학회지
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    • 제18권7호
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    • pp.48-55
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    • 2019
  • Soldiers have been exposed to the risk of chilblains in cold winters. Recent studies have described sensors and IOT devices that use independent power sources based on piezoelectric energy harvesting. Therefore, the heated shoes with an independent power source have been developed. For the application of energy harvesting to shoes, it is necessary to develop a unique harvester by considering human gait characteristics. Energy harvesters and ceramics were designed and fabricated in this study. The performances of these harvesters and ceramics were evaluated experimentally. Then, the harvesters and ceramics with superior performance were selected and applied to the system. Thereafter, the heating and charging performance of the system was tested under real walking conditions. The results show that the developed system can generate adequate energy to charge the battery and heat the shoes.