• 제목/요약/키워드: computer-assisted

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Efficient Peer-to-Peer File Sharing Using Network Coding in MANET

  • Lee, Uichin;Park, Joon-Sang;Lee, Seung-Hoon;Ro, Won-W.;Pau, Giovanni;Gerla, Mario
    • Journal of Communications and Networks
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    • 제10권4호
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    • pp.422-429
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    • 2008
  • Mobile peer-to-peer (P2P) systems have recently got in the limelight of the research community that is striving to build efficient and effective mobile content addressable networks. Along this line of research, we propose a new peer-to-peer file sharing protocol suited to mobile ad hoc networks (MANET). The main ingredients of our protocol are network coding and mobility assisted data propagation, i.e., single-hop communication. We argue that network coding in combination with single-hop communication allows P2P file sharing systems in MANET to operate in a more efficient manner and helps the systems to deal with typical MANET issues such as dynamic topology and intermittent connectivity as well as various other issues that have been disregarded in previous MANET P2P researches such as addressing, node/user density, non-cooperativeness, and unreliable channel. Via simulation, we show that our P2P protocol based on network coding and single-hop communication allows shorter file downloading delays compared to an existing MANET P2P protocol.

PC용 그래픽스 가속기의 쉐이더 기능을 이용한 볼륨 렌더링 (Exploiting Programmable Shaders in Hardware-Assisted Volume Rendering)

  • 임인성;강병권
    • 한국컴퓨터그래픽스학회논문지
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    • 제8권2호
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    • pp.23-29
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    • 2002
  • 컴퓨터 그래픽스 분야에 있어서 하드웨어의 활용은 렌더링 속도를 높이고 높은 수준의 결과를 얻기 위한 중요한 요소이다. 최근의 급속한 하드웨어의 발달은 기존에 불가능했던 다양한 여러 가지 효과들을 가능하게 해 주었으며, 쉐이더 기능을 이용하여 고급의 렌더링 기법들을 실시간에 구현할 수 있게 되었다. 본 논문에서는 이러한 하드웨어를 이용하여 최대 4가지의 물질에 대한 직접 볼륨 렌더링(direct volume rendering)을 수행할 수 있는 기법을 제안한다. 이 기법에서는 다양한 물질에 대한 렌더링 기능 이외에 그라디언트 값에 의한 물질 표면의 강조 효과, 광원의 거리에 의한 빛의 감소효과(Light Attenuation)와 Depth cueing, 복수의 광원에 의한 조명 효과 등의 다양한 고급 렌더링 기법들을 볼륨 렌더링에 적용할 수 있다.

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광음향효과를 이용한 게르마늄 나노구조 기반의 초음파 발생 소자 연구 (Optoacoustic Ultrasound Generator Based on Nanostructured Germanium)

  • 윤상혁;허준석
    • 한국광학회지
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    • 제26권5호
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    • pp.255-260
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    • 2015
  • 본 논문에서는 MAC(metal-assisted chemical) 에칭을 이용하여 Ge(Germanium) 표면에 나노구조를 형성하고, 그 위에 열팽창계수가 높은 PDMS를 적용하여 광음향효과를 이용한 초음파 발생 소자를 제작하였다. Ge 나노구조 위에 PDMS를 스핀 코팅하여 만든 초음파 발생 소자는 100 nm Cr(Chromium) 대비 약 3배의 초음파를 발생시켰다. 또한, Ge 나노구조를 PDMS 중앙에 위치시 킬 경우 쿼츠 기판을 통한 열손실이 줄어들어 100 nm Cr 대비 8.5배의 강한 초음파를 얻을 수 있었다.

조기 위암의 최신 치료 방법 : 복강경 원위부 위절제술, Hand-Assisted 복강경 원위부 위절제술과 소개복 원위부 위절제술의 비교 (Modern Treatment of Early Gastric Cancer: Comparison between Laparoscope Assisted vs Hand-Assisted Laparoscopic Distal Gastrectomy vs Open Distal Gastrectomy)

  • 윤기영;;이상호
    • Journal of Gastric Cancer
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    • 제4권2호
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    • pp.75-81
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    • 2004
  • Recently detection of early gastric cancer (EGC) has been increasing and the treatment strategies for gastric cancer have been changing. The purpose of this study was to compare clinical outcomes between laparoscopically assisted (LADG) and hand-assisted laparoscopic gastrectomy (HALDG) and open distal gastrectomy for early gastric cancer. This review is directed toward providing gastric surgeons with recent advances in the treatment of EGC. We investigated the English language literature for the past 12 years through computer searches which focused on : 1) Patient demographics, 2) Operation time, 3) Intra-operative blood loss, 4) Depth of invasion, 5) CBC, 6)Weight loss, 7) Analgesic requirement, 8)Time NPO, 9) Length of hospital stay, 10) Tumor stage, 11) Lymph node (LN) dissection, 12) Position of LN resected, 13) Complications. Improved operative techniques and surgical instrumentation have facilitated the development of minimally invasive gastric cancer surgery. The short-term benefits of laparoscopic gastrectomy included less surgical trauma, less pain, rapid return of gastrointestinal function, and shorter hospital stay, with no change in operative outcome. Laparoscopic gastrectomy was better accepted by the patients as a good procedure and promptly brought the patients back to their previous lifestyle and activities of daily living. But the advantages of HALDG for gastric cancer, extended lymph node dissection and intracorporeal anastomosis are feasible and easier with the presence of the internal hand. The hand-assisted laparoscopic (HALDG) method reported the best results in lymph node dissection.This method is an alternative to total laparoscopic radical gastrectomy. LADG and HALDG, when compared with conventional open gastrectomy, have several advantages. When performed by a skilled surgeon, LADG and HALDG are safe and useful techniques for patients with early-stage gastric cancer. Their appropriateness for gastric cancer surgery require further study.

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병원 급식시설의 미생물적 품질관리를 위한 전산 프로그램개발에 관한 연구 (Development of a Computer-Assisted Microbiological Quality Assurance Program for Hosipital Foodservice Operations)

  • 곽동경;장혜자;주세영
    • 한국식품조리과학회지
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    • 제8권2호
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    • pp.137-145
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    • 1992
  • A computer-assisted microbiological quality assurance program was developed based on HACCP data obtained from a 500 bed general hospital by assessing time and temperature conditions and microbiological qualities of six categories of menu items according to the process of food product flow. The purpose of the study was to develop a computer-assisted microbiological quality assurance program in order to simplify the assessment procedures and to provide a maximum assurance to foodservice personnel and the public. A 16-Bit personnel computer compatible with IBM-PC/AT was used. The data base files and processing programs were created using dBASE III plus packages. The contents of the computerized system are summarized as knows: 1. When the input program for hazard analysis runs, a series of questions are asked to determine hazards and assess their severity and risks. Critical control points and monitoring methods for CCPs are identified and saved in Master file. 2. Output and search programs for hazard analysis are composed of 6 categories of recipe data file list, code identification list, and HACCP identification of the specific menu item. 3. When the user selects a specific category of recipe from 6 categories presented on the screen and runs data file list, a series of menu item list, CCP list, monitoring methods list are generated. When the code search program runs, menu names, ingredients, amounts and a series of codes are generated. 4. When the user types in a menu item and an identification code, critical control points and monitoring methods are generated for each menu item.

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Black box-assisted fine-grained hierarchical access control scheme for epidemiological survey data

  • Xueyan Liu;Ruirui Sun;Linpeng Li;Wenjing Li;Tao Liu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권9호
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    • pp.2550-2572
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    • 2023
  • Epidemiological survey is an important means for the prevention and control of infectious diseases. Due to the particularity of the epidemic survey, 1) epidemiological survey in epidemic prevention and control has a wide range of people involved, a large number of data collected, strong requirements for information disclosure and high timeliness of data processing; 2) the epidemiological survey data need to be disclosed at different institutions and the use of data has different permission requirements. As a result, it easily causes personal privacy disclosure. Therefore, traditional access control technologies are unsuitable for the privacy protection of epidemiological survey data. In view of these situations, we propose a black box-assisted fine-grained hierarchical access control scheme for epidemiological survey data. Firstly, a black box-assisted multi-attribute authority management mechanism without a trusted center is established to avoid authority deception. Meanwhile, the establishment of a master key-free system not only reduces the storage load but also prevents the risk of master key disclosure. Secondly, a sensitivity classification method is proposed according to the confidentiality degree of the institution to which the data belong and the importance of the data properties to set fine-grained access permission. Thirdly, a hierarchical authorization algorithm combined with data sensitivity and hierarchical attribute-based encryption (ABE) technology is proposed to achieve hierarchical access control of epidemiological survey data. Efficiency analysis and experiments show that the scheme meets the security requirements of privacy protection and key management in epidemiological survey.

A Practical Digital Video Database based on Language and Image Analysis

  • Liang, Yiqing
    • 한국데이타베이스학회:학술대회논문집
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    • 한국데이타베이스학회 1997년도 International Conference MULTIMEDIA DATABASES on INTERNET
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    • pp.24-48
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    • 1997
  • . Supported byㆍDARPA′s image Understanding (IU) program under "Video Retrieval Based on Language and image Analysis" project.DARPA′s Computer Assisted Education and Training Initiative program (CAETI)ㆍObjective: Develop practical systems for automatic understanding and indexing of video sequences using both audio and video tracks(omitted)

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개념 기반의 코스웨어 표현 방법과 이를 이용한 인터넷 기반의 코스웨어 저작 도구의 구현 (An Implementation of an Courseware Authoring Tool Using a Concept based Courseware Representation Method)

  • 김만석;김창화
    • 컴퓨터교육학회논문지
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    • 제5권2호
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    • pp.39-48
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    • 2002
  • 지능형 컴퓨터 보조교육(ICAI : Intelligent Computer Assisted Instruction) 시스템은 전문가 모듈, 교사 모듈, 학습자 모듈, 정숙 모듈 등의 4가지 모듈로 구성하는 것이 일반적이다. 각 모듈 구성에 있어 교과 내용과 평가 문제, 평가 결과와 진단, 진단 결과에 따른 처방 등의 관련 전략을 효율적이고 체계적으로 제어하기 위한 규칙이 필요하다. 이를 위해 교과 과정을 일정한 단위로 구분하는 방법을 제시하였다. 또한 구분 된 단위간에 연관성을 부여하고 이를 참고로 학습 진행과 평가, 진단, 처방의 모든 과정에 적용할 수 있도록 하였다. 구분된 단위(개념)와 연관성(관계)을 그래프 형식으로 나타내는 방법을 제안하였다. 또한, 이 개념을 적용하여 인터넷 상에서 여러 전문가가 협력하여 동시에 코스웨어를 구축할 수 있는 환경을 지원하는 인터넷 기반의 코스웨어 저작 도구를 구현하였다.

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