• 제목/요약/키워드: MD&A

검색결과 2,642건 처리시간 0.037초

기존선 전차선로 상세설계 소프트웨어 개발 (A Development of Detail Design Software for Conventional Catenary System)

  • 이기원;권삼영;조용현;이태권;이경훈
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2008년도 춘계학술대회 논문집
    • /
    • pp.481-488
    • /
    • 2008
  • 전차선로 상세설계는 평면도(pegging plan) 작업과 장주도 작업으로 분류될 수 있다. 평면도 작업은 선로 방향으로 전주의 위치, 편위, 장력길이 등을 결정하여 설계하는 것이고, 장주도 작업은 전주 위치에서 선로에 직각방향의 도면을 그리는 작업으로, 장주도에서는 전주, 기초, 가동브래킷, 전차선 및 조가선을 포함한 모든 선 등의 위치 및 크기 등을 확인할 수 있고, 장주별 사용된 자재를 표시한다. 본 연구에서는 입력조건 및 선로조건 등에 따라 기존선 180km/h급 전차선로의 장주도를 자동으로 설계할 수 있는 프로그램을 개발하였다. 그리고, 본 프로그램을 통하여 사용한 자재를 장주별 / 섹션별로 관리할 수 있고, 드로퍼 길이를 자동으로 계산할 수 있도록 하였다. 본 프로그램의 입력 및 계산은 C#을 이용하여 MS Excel 2007 기반의 친숙한 구조의 GUI를 개발하였으며, 장주도 출력에는 C#(ObjectARX)를 이용하여 개발하였다.

  • PDF

멀티모드 단말기의 라디오 라이브러리를 위한 표준 기능 블록의 선정 및 구현 (Selection and implementation of Standard Functional Blocks for Radio Library in multi-mode mobile device)

  • 정일도;최승원
    • 디지털산업정보학회논문지
    • /
    • 제12권3호
    • /
    • pp.125-132
    • /
    • 2016
  • The European Telecommunication Standards Institute (ETSI) Technical Committee (TC) Reconfigurable Radio Systems (RRS) is standardizing the multi-mode Mobile Device (MD). The configuration of multi-mode MD is determined by the downloaded mobile communication standard software. In this paper, we introduce the Radio Library concept for multi-mode MD which is one of the key components of RRS standard. This paper also introduces the Standard Functional Block which is a part of Radio Library. A method for selecting efficiency SFBs for multi-mode MD is presented and a Radio Library is generated based on the selected SFBs. This paper also shows sample Standard Functional Block Set which included in Radio Library. In order to verify the compatibility of the generated Radio Library which was made by C language, we implement the LTE Rel-10 and Wi-Fi(802.11b) to show the efficiency of generating a mobile communication standard software based on the Radio Library. Then using the Prograph Visual Programming MartenTM 1.6.4, we compiled our LTE Rel-10 and Wi-Fi(802.11b) source code.

Development of Multiple Beam Optical Tweezers

  • Lee Dong-Jin;LeBrun Thomas W.;Balijepalli Arvind;Gorman JasonJ.;Gagnon Cedric;Hong Dae-Hie;Chang Esthe rH.
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2005년도 춘계학술대회 논문집
    • /
    • pp.1501-1506
    • /
    • 2005
  • This paper presents the design of a multiple beam optical tweezers instrument used for manipulating micro/nano-sized components. The basic equations used in designing the optical tweezers are derived and the stable and time-sharing multiple beam optical tweezers are constructed with scanning mirrors. The laser beam passes through a series of optical components such as lenses, mirrors, and scanning mirrors, and overfills the entrance aperture of microscope objective, which gives a stable trap. By rotating the laser beam with the scanning mirror, the focal positions are translated in the specimen plane and multiple micro/nano-sized objects can be moved. The constructed optical tweezers is used to manipulate cells and liposomes simultaneously and to trap multiple nano-wires. The experiments prove that the developed optical tweezers can be a very versatile manipulation tool for studying gene therapy and nano device fabrication.

  • PDF

사용자 인증과 암호화를 위한 키 생성 알고리즘 구현 (Implementation of Key Generation Algorithm for User Authentication and Encryption)

  • 우찬일;전세길
    • 한국항행학회논문지
    • /
    • 제11권1호
    • /
    • pp.93-98
    • /
    • 2007
  • 통신망의 급속한 발전으로 정보보호의 중요성은 점점 더 증가하고 있다. 따라서, 이러한 문제들을 해결하기 위하여 암호시스템이 사용 되었으며 암호시스템의 안전성은 키에 의존하고 있다. 본 논문에서는 암호학적으로 안전한 MD5 해쉬 함수를 기반으로 한 키 생성 방법을 제안한다. MD5 해쉬 함수의 기본 구조는 유한 길이의 입력을 512 비트 블록 단위로 처리하고 128 비트의 고정된 출력을 생성하는 반복적인 구조이다. 제안 방법의 안전성은 해쉬 함수를 기반으로 하고 있으며, 제안 방법은 인증 알고리즘이나 데이터 암호화를 위해 유용하게 적용될 것으로 사료된다.

  • PDF

Very Early-Onset Inflammatory Bowel Disease: A Challenging Field for Pediatric Gastroenterologists

  • Arai, Katsuhiro
    • Pediatric Gastroenterology, Hepatology & Nutrition
    • /
    • 제23권5호
    • /
    • pp.411-422
    • /
    • 2020
  • With the increasing number of children with inflammatory bowel disease (IBD), very early-onset IBD (VEO-IBD), defined as IBD that is diagnosed or that develops before 6 years of age, has become a field of innovation among pediatric gastroenterologists. Advances in genetic testing have enabled the diagnosis of IBD caused by gene mutations, also known as monogenic or Mendelian disorder-associated IBD (MD-IBD), with approximately 60 causative genes reported to date. The diagnosis of VEO-IBD requires endoscopic and histological evaluations. However, satisfactory small bowel imaging studies may not be feasible in this small population. Both genetic and immunological approaches are necessary for the diagnosis of MD-IBD, which can differ among countries according to the available resources. As a result of the use of targeted gene panels covered by the national health insurance and the nationwide research project investigating inborn errors of immunity, an efficient approach for the diagnosis of MD-IBD has been developed in Japan. Proper management of VEO-IBD by pediatric gastroenterologists constitutes a challenge. Some MD-IBDs can be curable by allogenic hematopoietic stem cell transplantation. With an understanding of the affected gene functions, targeted therapies are being developed. Social and psychological support systems for both children and their families should also be provided to improve their quality of life. Multidisciplinary team care would contribute to early diagnosis, proper therapeutic interventions, and improved quality of life in patients and their families.

Clinical Features of Deep Neck Infections and Predisposing Factors for Mediastinal Extension

  • Kang, Shin-Kwang;Lee, Seok-Kee;Oh, Hyun-Kong;Kang, Min-Woong;Na, Myung-Hoon;Yu, Jae-Hyeon;Koo, Bon-Seok;Lim, Seung-Pyung
    • Journal of Chest Surgery
    • /
    • 제45권3호
    • /
    • pp.171-176
    • /
    • 2012
  • Background: Deep neck infections (DNI) can originate from infection in the potential spaces and fascial planes of the neck. DNI can be managed without surgery, but there are cases that need surgical treatment, especially in the case of mediastinal involvement. The aim of this study is to identify clinical features of DNI and analyze the predisposing factors for mediastinal extension. Materials and Methods: We reviewed medical records of 56 patients suffering from DNI who underwent cervical drainage only (CD group) and those who underwent cervical drainage combined with mediastinal drainage for descending necrotizing mediastinitis (MD group) from August 2003 to May 2009 and compared the clinical features of each group and the predisposing factors for mediastinal extension. Results: Forty-four out of the 56 patients underwent cervical drainage only (79%) and 12 patients needed both cervical and mediastinal drainage (21%). There were no differences between the two groups in gender (p=0.28), but the MD group was older than the CD group (CD group, $44.2{\pm}23.2$ years; MD group, $55.6{\pm}12.1$ years; p=0.03). The MD group had a higher rate of co-morbidity than the CD group (p=0.04). The CD group involved more than two spaces in 14 cases (32%) and retropharyngeal involvement in 12 cases (27%). The MD group involved more than two spaces in 11 cases (92%) and retropharyngeal involvement in 12 cases (100%). Organism identification took place in 28 cases (64%) of the CD group and 3 cases of (25%) the MD group (p=0.02). The mean hospital stay of the CD group was $21.5{\pm}15.9$ days and that of the MD group was $41.4{\pm}29.4$ days (p=0.04). Conclusion: The predisposing factors of mediastinal extension in DNI were older age, involvement of two or more spaces, especially including the retropharyngeal space, and more comorbidities. The MD group had a longer hospital stay, higher mortality, and more failure to identify causative organisms of causative organisms than the CD group.

Full-Endoscopic versus Minimally Invasive Lumbar Interbody Fusion for Lumbar Degenerative Diseases : A Systematic Review and Meta-Analysis

  • Son, Seong;Yoo, Byung Rhae;Lee, Sang Gu;Kim, Woo Kyung;Jung, Jong Myung
    • Journal of Korean Neurosurgical Society
    • /
    • 제65권4호
    • /
    • pp.539-548
    • /
    • 2022
  • Objective : Although full-endoscopic lumbar interbody fusion (Endo-LIF) has been tried as the latest alternative technique to minimally invasive transforaminal lumbar interobody fusion (MIS-TLIF) since mid-2010, the evidence is still lacking. We compared the clinical outcome and safety of Endo-LIF to MIS-TLIF for lumbar degenerative disease. Methods : We systematically searched electronic databases, including PubMed, EMBASE, and Cochrane Library to find literature comparing Endo-LIF to MIS-TLIF. The results retrieved were last updated on December 11, 2020. The perioperative outcome included the operation time, blood loss, complication, and hospital stay. The clinical outcomes included Visual analog scale (VAS) of low back pain and leg pain and Oswestry disability index (ODI), and the radiological outcome included pseudoarthosis rate with 12-month minimum follow-up. Results : Four retrospective observational studies and one prospective observational study comprising 423 patients (183 Endo-LIF and 241 MIS-TLIF) were included, and the pooled data analysis revealed low heterogeneity between studies in our review. Baseline characteristics including age and sex were not different between the two groups. Operation time was significantly longer in Endo-LIF (mean difference [MD], 23.220 minutes; 95% confidence interval [CI], 10.669-35.771; p=0.001). However, Endo-LIF resulted in less perioperative blood loss (MD, -144.710 mL; 95% CI, 247.941-41.478; p=0.023). Although VAS back pain at final (MD, -0.120; p=0.586), leg pain within 2 weeks (MD, 0.005; p=0.293), VAS leg pain at final (MD, 0.099; p=0.099), ODI at final (MD, 0.141; p=0.093) were not different, VAS back pain within 2 weeks was more favorable in the Endo-LIF (MD, -1.538; 95% CI, -2.044 to -1.032; p<0.001). On the other hand, no statistically significant group difference in complication rate (relative risk [RR], 0.709; p=0.774), hospital stay (MD, -2.399; p=0.151), and pseudoarthrosis rate (RR, 1.284; p=0.736) were found. Conclusion : Relative to MIS-TLIF, immediate outcomes were favorable in Endo-LIF in terms of blood loss and immediate VAS back pain, although complication rate, mid-term clinical outcomes, and fusion rate were not different. However, the challenges for Endo-LIF include longer operation time which means a difficult learning curve and limited surgical indication which means patient selection bias. Larger-scale, well-designed study with long-term follow-up and randomized controlled trials are needed to confirm and update the results of this systematic review.

Mobile IP 핸드오프를 위한 효율적인 TCP 방식 (An Efficient TCP Mechanism for Mobile IP Handoffs)

  • 권재우;박희동;조유제
    • 한국정보과학회논문지:정보통신
    • /
    • 제29권5호
    • /
    • pp.501-509
    • /
    • 2002
  • 기존 TCP가 이동 환경에 그대로 적용될 경우, 빈번하게 발생하는 핸드오프에 의한 패킷 손실에 대해 불필요한 폭주 제어 알고리즘을 수행함으로 인해 TCP의 성능 저하를 초래한다. 본 논문에서는 이동호스트의 핸드오프 발생 사실을 최대한 빨리 감지하기 위한 TCP-MD 방식과 핸드오프 시 등록 과정동안 송신측에서 전송을 중지하여 패킷 손실을 최소화하는 TCP-R 방식을 제안한다. 제안된 방식은 종단간 TCP 연결을 유지하며 이로 인해 기존망과 호환이 가능하도록 한다. 또한, 유선 구간에서는 기존 TCP의 수정없이 사용하고, 핸드오프 발생 사실을 알리기 위해 별도의 메시지 정의 없이, 단지 이동 호스트 내 TCP에서 Mobile IP 핸드오프 시 등록 관련 메시지를 이용함으로써 TCP 성능을 향상시킬 수 있고 구현이 단순하다는 장점이 있다. 다양한 환경에 대한 시뮬레이션을 수행하여 각 제안된 방식들을 적용할 경우 TCP의 성능을 크게 향상시킬 수 있음을 보였다.

DV-Xα분자궤도법을 이용한 Zn alloy의 기계적 성질 예측 (A study on the prediction of the mechanical properties of Zinc alloys using DV-Xα Molecular Orbital Method)

  • 나혜성;공종판;김양수;강정윤
    • 한국재료학회지
    • /
    • 제17권5호
    • /
    • pp.250-255
    • /
    • 2007
  • The alloying effects on the electronic structures of Zinc are investigated using the relativistic $DV-X{\alpha}molecular$ orbital method in order to obtain useful information for alloy design. A new parameter which is the d obital energy level(Md) and the bonder order(Bo) of alloying elements in Zinc was introduced and used for prediction of the mechanical properties. The Md correlated with the atomic radius and the electronegativity of elements. The Bo is a measure of the strength of the covalent bond between M and X atoms. First-principles calculations of electronic structures were performed with a series of models composed of a MZn18 cluster and the electronic states were calculated by the discrete variational- $X{\alpha}method$ by using the program code SCAT. The central Zinc atom(M) in the cluster was replaced by various alloying elements. In this study energy level structures of pure Zinc and alloyed Zinc were calculated. From calculated results of energy level structures in MZn18 cluster, We found Md and Bo values for various elements of Zn. In this work, Md and Bo values correlated to the tensile strength for the Zn. These results will give some guide to design of zinc based alloys for high temperature applications and it is possible the excellent alloys design.

MBR technology for textile wastewater treatment: First experience in Bangladesh

  • Saha, Pradip;Hossain, Md. Zakir;Mozumder, Md. Salatul I.;Uddin, Md. Tamez;Islam, Md. Akhtarul;Hoinkis, Jan;Deowan, Shamim A.;Drioli, Enrico;Figoli, Alberto
    • Membrane and Water Treatment
    • /
    • 제5권3호
    • /
    • pp.197-205
    • /
    • 2014
  • For the first time in Bangladesh, a bench scale membrane bioreactor (MBR) unit was tested in treating a textile wastewater in the industry premises of EOS Textile Mills LTD, Dhaka for three months. The performance of the unit was compared with that of the conventional activated sludge treatment plant, which is in operation in the same premises. The COD and BOD removal efficiency of the MBR unit reached to around 90% and 80% respectively in 20 days whereas the removal efficiency of the conventional treatment plant was as low as 40-50% and 38-40% respectively. The outlet COD and the BOD level for the MBR unit remained stable in spite of the fluctuation in the feed value, while the conventional effluent treatment plant (ETP) failed to keep any stabilized level. The performance of the MBR unit was much superior to that of the functional ETP and the water treated by the MBR system can meet disposal standard.