• 제목/요약/키워드: Link Flexibility

검색결과 103건 처리시간 0.024초

Fading 채널의 MANET에서의 라우팅 프로토콜 성능 분석 (Evaluation on Routing Protocols over MANETs with Fading Channel)

  • ;김병서
    • 한국인터넷방송통신학회논문지
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    • 제11권5호
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    • pp.41-46
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    • 2011
  • 이동성을 가진 무선 분산망은 다양한 응용환경의 발달로 많은 관심을 가지고 연구되어지고 있으며 이러한 환경에서의 트래픽은 이전의 단순한 데이터에서 벗어서나 음성과 비디오와 같은 멀티미디어 트래픽을 포함하게 되었다. 그러나 유선망과는 달리 무선망은 다양한 원인에 의하여 전송 경로가 끊어지는 일들이 자주 일어나게 되며, 이는 더욱 멀티미디어 트래픽의 전송을 어렵게 하고 있다. 다양한 무선 채널 환경에서의 멀티미디어 트래픽 전송에 대한 연구 결과 들이 있어왔으나 무선 페이딩 환경과 이동성을 포함한 채널 환경과 다양한 라우팅 프로토콜을 이용한 멀티미디어 트래픽의 성능 평가에 대한 연구는 진행된바 없기에 본 논문에서는 그러한 환경에서 멀티미디어 트래픽의 전송 성능에 심도 깊은 모의실험을 통하여 분석하고 멀티미디어 서비스의 우선순위에 따른 나은 라우팅 프로토콜을 권장한다.

시스템 가구의 특성에 관한 연구 (A Study on the Characteristics of System Furniture)

  • 신홍경
    • 한국실내디자인학회논문집
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    • 제6호
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    • pp.45-52
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    • 1995
  • The presentation of the method by which the furniture and the architecture can be unified in one category, and the study and the verification on the mutual relation in the shape and the function are having been consistently made till the late twenties. The change of the social structure such as increasing the unit dwelling space with the small scale comes to need the efficiency in using space and the open dwelling space by the systematic spa-cial formation. Therefore, the understanding of the mean-ing and the characteristics of system furnitures as the design method which can meet such needs will be made here in this study. The application of the systematic consideration as the method of interior design means the formation of the firm image on the spacial environment through the mix-ture and link of the heterogeneous factors, the organic connection of each surface, the establishment of the natu-ral relation by linking the heterogeneous materials mutu-ally. and the easiness of the entire plan in the end. This study aims at analyzing and studying the typical charac-teristics by understanding the historical background and methodical principle which enabled the appearance of this kind of thought, and the adapted cases of the wood and metal material system furniture. There may be difference between the structural sub-stance and formative consideration. Transformative furni-ture which consists of the factors is the concept for the encrease of the multi purpose value by mixing the unit cabinets. One system can be separated horizontally, verti-cally, and to the drawers, and it gives us the disengage-ment from the artificial environment, since all the heights and width can be transformed as per each situa-tion of the space. The factors which can not be found in the other existing furniture are as follows. 1. disengagement from the artificial environment. 2. establishing the new productiosn trend as freed from the customers' fashion trend. 3. presenting the producing condition which leads the exact technology. 4. flexibility of the furniture which enables the reduction and enlargement in each situation.

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Stochastic Channel Modeling for Railway Tunnel Scenarios at 25 GHz

  • He, Danping;Ai, Bo;Guan, Ke;Zhong, Zhangdui;Hui, Bing;Kim, Junhyeong;Chung, Heesang;Kim, Ilgyu
    • ETRI Journal
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    • 제40권1호
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    • pp.39-50
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    • 2018
  • More people prefer using rail traffic for travel or for commuting owing to its convenience and flexibility. The railway scenario has become an important communication scenario in the fifth generation era. The communication system should be designed to support high-data-rate demands with seamless connectivity at a high mobility. In this paper, the channel characteristics are studied and modeled for the railway tunnel scenario with straight and curved route shapes. On the basis of measurements using the "Mobile Hotspot Network" system, a three-dimensional ray tracer (RT) is calibrated and validated for the target scenarios. More channel characteristics are explored via RT simulations at 25.25 GHz with a 500-MHz bandwidth. The key channel parameters are extracted, provided, and incorporated into a 3rd-Generation-Partnership-Project-like stochastic channel generator. The necessary channel information can be practically realized, which can support the link-level and system-level design of the communication system in similar scenarios.

APPLICATION OF FIRE RESEARCH TO BUILDING FIRE SAFETY DESIGN - CURRENT BENEFITS AND FUTURE NEEDS

  • Bressington, Peter;Johnson, Peter
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.392-403
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    • 1997
  • There is a strong international move towards performance based fire regulations for buildings with New Zealand and Australia at the forefront of research in this fold. The reform of regulations is thought to offer more innovation and flexibility in building design and greater cost effectiveness in construction. An important part of the research in this area is related to the development of agreed approaches to fire safety design, such as the Fire Code Reform Centre's "Fire Engineering Guidelines" or New Zealand's "Fire Engineering Design Guide". Such design process documents have incorporated or referenced much of the latest research in areas such as: tenability criteria fire compartment models egress models risk assessment. Use of such design guidelines or equivalents in major projects in countries such as Hong Kong and Australia have highlighted where fro engineering can offer real benefits to building designers and ultimately building owners and operators. However, there is still much research to be done and use of a systematic, logical design approach clearly identifies where design data or modelling techniques are still urgently required. Such areas are: fire growth rates and peak heat release rates for non-residential occupancies pre-movement times related to egress experimental validation and limits of applicability of CFD and other compartment Ire models probability/reliability data on fire protection systems for risk based analysis. Examples from case studies will be shown where lack of such research and poor judgement can lead to inferior design solutions or where unnecessarily conservative designs can lead to cost excesses. In summary, the link between Ire engineering designers and the research community is very important to highlight areas of fire research that will have the most benefit to the building and construction industry.nstruction industry.

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OFDM-TDMA 메쉬 네트워크를 위한 다중경로 QoS 라우팅 프로토콜 (A Multi-path QoS Routing Protocol for the OFDM-TDMA Mesh Networks)

  • 최정욱;이혁준
    • 한국ITS학회 논문지
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    • 제14권1호
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    • pp.57-67
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    • 2015
  • 무선 메쉬 네트워크에서 다중경로 라우팅 프로토콜은 QoS 충족 또는 링크 단절에 대한 강건성 확보를 위한 해결책으로 자주 사용되어 왔으며, 무선 전술통신 및 재난구조 통신에서는 QoS와 강건성을 동시에 충족시키는 방법에 대한 필요성이 강조되고 있다. 본 논문에서 제안하는 라우팅 프로토콜은 OFDM-TDMA collision-free MAC을 기반으로 on-demand 방식으로 대역폭 및 지연시간 제한을 포함하는 사용자의 세션별 QoS 요구사항을 충족시켜 줄 수 있는 다중경로들을 탐색 및 관리하고, 전송실패가 발생할 경우 경로 재탐색 이전에 대체경로를 선택하여 데이터를 재전송하도록 함으로써 지연 및 수용능력 간 트레이드오프를 완화하는 동시에 강건성을 증가시킨다. 본 논문에서는 시뮬레이션을 통해 제안하는 프로토콜의 성능을 분석하여 제안하는 프로토콜이 QoS 보장 측면과 데이터의 전송성공률 측면에서 우수을 보인다.

Incorporation preference for rubber-steel bearing isolation in retrofitting existing multi storied building

  • Islam, A.B.M. Saiful;Jumaat, Mohd Zamin;Hussain, Raja Rizwan;Hosen, Md. Akter;Huda, Md. Nazmul
    • Computers and Concrete
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    • 제16권4호
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    • pp.503-529
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    • 2015
  • Traditionally, multi-story buildings are designed to provide stiffer structural support to withstand lateral earthquake loading. Introducing flexible elements at the base of a structure and providing sufficient damping is an alternative way to mitigate seismic hazards. These features can be achieved with a device known as an isolator. This paper covers the design of base isolators for multi-story buildings in medium-risk seismicity regions and evaluates the structural responses of such isolators. The well-known tower building for police personnel built in Dhaka, Bangladesh by the Public Works Department (PWD) has been used as a case study to justify the viability of incorporating base isolators. The objective of this research was to establish a simplified model of the building that can be effectively used for dynamic analysis, to evaluate the structural status, and to suggest an alternative option to handle the lateral seismic load. A finite element model was incorporated to understand the structural responses. Rubber-steel bearing (RSB) isolators such as Lead rubber bearing (LRB) and high damping rubber bearing (HDRB) were used in the model to insert an isolator link element in the structural base. The nonlinearities of rubber-steel bearings were considered in detail. Linear static, linear dynamic, and nonlinear dynamic analyses were performed for both fixed-based (FB) and base isolated (BI) buildings considering the earthquake accelerograms, histories, and response spectra of the geological sites. Both the time-domain and frequency-domain approaches were used for dynamic solutions. The results indicated that for existing multi-story buildings, RSB diminishes the muscular amount of structural response compared to conventional non-isolated structures. The device also allows for higher horizontal displacement and greater structural flexibility. The suggested isolation technique is able to mitigate the structural hazard under even strong earthquake vulnerability.

생활무용 참가가 여성의 신체이미지 및 자아존중감에 미치는 영향 (Relationship of Leisure Dance Participation, Physical Image and Self-Esteem among Women)

  • 곽한병;구경자
    • 한국콘텐츠학회논문지
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    • 제10권8호
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    • pp.407-416
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    • 2010
  • 이 연구의 목적은 생활무용 참가가 여성의 신체이미지 및 자아존중감의 관계를 규명하는데 있다. 이를 위하여 2009년 서울 경기도지역에 있는 스포츠센터, 일반동호회, 지역동호회, 댄스학원, 일반인을 대상으로 생활무용에 참여하고 있는 20~50대 성인여성을 모집단으로 설정한 다음, 유의표집법을 이용하여 300명을 추출 하였다. 설문지의 신뢰도는 분석결과 Cronbach's $\alpha$ 값이 .70이상으로 나타났다. 이 연구에서 사용한 주요통계기법은 빈도분석, 신뢰도 요인분석, 공변량분석, 회귀분석 및 경로분석이다. 이상과 같은 연구방법 및 절차를 통해 도출된 결론은 다음과 같다. 첫째, 생활무용 참가여성은 비참가여성에 비해 신체이미지 및 자아존중감을 더 긍정적으로 평가한다. 둘째, 생활무용 참가기간은 체형, 만족, 유연성요인에 영향을 미치고 있으며, 참가강도는 체형과 근력요인에 영향을 미친다. 셋째, 생활무용참가기간은 자아존중감에 영향을 미치며, 참가빈도는 부적 영향을 미치는 것으로 나타났다. 넷째, 여성의 생활무용 참가정도는 신체 이미지 그리고 자아존중감에 인과적 영향을 미친다. 즉 생활무용 활동 정도는 자아존중감에 직접적인 영향을 미칠 뿐만 아니라, 신체이미지 변수를 통하여 자아존중감에 간접적인 영향을 미친다. 이러한 결과에서 보듯이 신체이미지는 생활무용 참가와 자아존중감을 연결해주는 중요한 매개변수 역할을 한다.

복합환승역사 통행자 기반 통합 모빌리티 평가 기법 개발 (Methodology for Assessing an Integrated Mobility of the Passenger Passing through Intermodal Transit Center)

  • 유소영;김경태;정은비;이준
    • 한국ITS학회 논문지
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    • 제16권5호
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    • pp.12-28
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    • 2017
  • Mobility 4.0으로 일컬어지는 교통서비스의 핵심은 유연성 있는 모빌리티 구현이며, 이를 위해 수요-공급을 실시간, 유기적으로 이어줄 수 있는 플랫폼 구축이 요구되고 있다. 즉, 교통 정보 혹은 통합 모빌리티를 빅데이터 기반의 표준화 및 상시 업데이트가 가능한 DB로 구축하고 이를 분석할 수 있는 객관적이고 과학적인 분석 체계를 제시하는 것이다. 이러한 측면에서, 보행 통행을 포함하는 복합환승역사와 이를 기반으로 통행 전주기로 확장하여 분석하는 연구는 미흡한 실정이다. 이에 본 연구는 복합환승역사를 이용하는 통행자 중심의 통합 모빌리티 분석 체계를 3단계로 구성하여, Data Repository 생성 모듈, 통합 모빌리티 분석 모듈, 공간 정보를 융합한 결과해석 모듈로 정의하였다. 철도 및 광역버스 환승역사(사당, 신도림, 교대, 광화문, 삼성, 강남, 잠실) 7개 역사를 분석 대상 역사로 지정하여 사례 분석을 수행하였다. 분석 대상 역사는 통계적 유의성에 근거하여 3개 그룹으로 구분되었으며, 자료 기반으로 한 통행 전주기 분석과 해석을 통해 보다 다양하고 체계적인 복합환승역사 분석이 가능함을 제시하였다.

콘크리트 및 복합재료용 멀티스케일 가상 시험기계에 관한 소고 (Multiscale Virtual Testing Machines of Concrete and Other Composite Materials: A Review)

  • ;박솔뫼;양범주;이행기
    • 한국전산구조공학회논문집
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    • 제31권4호
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    • pp.173-181
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    • 2018
  • 최근 복합재료는 향상된 성능, 내구성 및 여러 특정 요구성능에 대한 설계 유연성으로 인해 다양한 분야에서 활발히 활용되고 있다. 컴퓨터 성능이 발달함에 따라, 복합재료의 복잡한 거동에 대한 정확도 높은 모델 역시 함께 연구되고 있으며, 이로 인해 가상시험이 복합재료 거동에 대한 실험을 대체하거나 보충하는데 중요한 역할을 하고 있다. 본 논문에서는 나노수준부터 구조물 단위까지 이르는 다양한 length scale의 homogenization을 통한 멀티스케일 모델링에 대한 문헌을 분석하였다. 또한, 콘크리트 거동 연구에 대한 통합모델의 특징을 다루었으며, 가상 시험기계에 대한 최근 연구동향 및 전망에 대하여 다루었다.

Use of Multimedia Technologies in Extra-Curricular Works in Order to Improve the Quality of Training of Future Specialists

  • Tverezovska, Nina;Kovbasa, Tetiana;Pryhalinska, Tetiana;Mykhniuk, Serhii;Lopushan, Tetiana;Radionova, Olena;Kuchai, Tetiana
    • International Journal of Computer Science & Network Security
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    • 제22권9호
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    • pp.35-42
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    • 2022
  • The article deals with the role of extra-curricular work by means of multimedia technologies in order to improve the quality of training of future specialists. An important condition for achieving high results in training specialists is the optimal combination of classroom and independent extra-curricular work of students by means of multimedia technologies. Very significant is the development of student independence, the formation of skills of independent search activity, the ability to take responsibility, independently solve a problem, find constructive solutions, a way out of a crisis situation, and so on. Extra-curricular work forms students' ability to master the techniques of analysis, synthesis, generalization, comparison; develops flexibility of thinking; opens up opportunities for the development and stabilization of positive learning motives to activate the process of mastering knowledge by means of multimedia technologies as a means of forming the personality of a highly qualified specialist. The concept of multimedia as one of the priority areas of Information Technology, which plays a particularly important role in the process of informatization of education, is revealed, and its advantages in education are shown. The advent of multimedia systems optimizes transformations in education, in many areas of professional activity, science, art, etc. The necessity of distance learning to improve the quality of training of future specialists using multimedia technologies in extra-curricular work is justified. The effectiveness of pedagogical support in the process of distance learning is achieved by the following conditions, which is revealed in the article. Various forms and types of extra-curricular work of students that are used in the modern practice of the educational environment of a higher education institution are described. Scientific and informational activity is considered a key area of information activity. The analysis of scientific and information activities in the field of education allows us to identify its main functions, which emphasize the growing role of scientific information in the education system, in particular, extra-curricular work using multimedia technologies. Operational, complete, accurate, targeted information that meets objective and subjective needs becomes an important link between the field of management, science and practice.