• Title/Summary/Keyword: Technical Issue

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Content aware Internet Application Traffic Measurement and Analysis for Precise Accounting and Billing (정밀 과금을 위한 컨텐츠기반 인터넷 응용 트래픽 측정 및 분석)

  • 최태상;박정숙;윤승현;김형환;김창훈;정형석;이병준;정태수
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.10
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    • pp.138-149
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    • 2003
  • As the Internet is quickly evolving from best-effort networks to business quality networks, billing based on the precise traffic measurement becomes an important issue for Internet Service Providers (ISPs). Billing settlement is necessary not only between ISP and customers but also between ISPs. Currently, most ISPs use a flat rate charging policy. Besides the degree of difficulty in deriving appropriate charging policies agreeable by a concerned party, there are substantial technical challenges to come up with a good usage-based accounting system. Usage-based accounting depending on IP packet header information only is not sufficient anymore due to highly dynamic nature of the development and the use of the Internet applications such as peer-to-peer and network games. They are using port numbers dynamically and even several applications can use the same port number. Thus, more precise means of classifying them and accounting their traffic usages are required. In this paper, we propose a high performance, adaptable, configurable, and scalable content-aware application traffic measurement and analysis system which can achieve very accurate usage-based accounting.

Operation and Maintenance of Spent Fuel Storage and Transport Casks (사용후핵연료 수송저장 용기의 운전 및 유지보수)

  • 구정회;서기석;정원명;유길성;박성원
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.345-345
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    • 2004
  • The spent fuel transportation casks have used as one of the most essential component in the nuclear industry. And, the number of the cask has been significantly increased in recent years. While the bulk amount of spent fuel in the world is still kept in the storage pool, the number of countries which have chosen the advantages of dual purpose cask for transportation and storage is rapidly increasing. The technical experience in the area of spent fuel transportation cask operation and maintenance for long period is also available and will be well utilized also in storage casks. The increasing use of casks for dual and multiple purposes raises an issue of long term consideration by international standardization. Accordingly IAEA is providing a regulatory requirements and guidelines as an effort for this standardization.

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A Empirical Research for Subcontractor Selection Model in the International Construction Project (해외건설 전문건설기업 선정모델 개선을 위한 실증 연구)

  • Lee, Changjun;Seok, Hochan;Lee, Sangjun;Jang, Woosik;Han, Seung-Heon
    • Korean Journal of Construction Engineering and Management
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    • v.17 no.2
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    • pp.118-126
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    • 2016
  • International construction market have quantitatively increased and have reached up to 700 Bil. US$ through active effort of construction firms and government. In spite of this increase, substantiality issue has been constantly disputed due to qualitative problems such as lack of capability and technical shortage. To overcome these problems, many methods in performing quantitative growth and qualitative substantiality of overseas construction are being researched which showed that selection of subcontractors in general contractor is regarded as a very important success factor. However, it is difficult to make a reasonable decision for selecting the subcontractors due to the lack of evaluation standards and reliability. This study proposes an improved evaluation system through adjustment of the evaluation indicators using correlations analysis and multiple regression analysis with pre-qualification and performance evaluation of 121 firms in 6 countries.

A NUMERICAL STUDY ON THERMAL DESIGN OF A LARGE-AREA HOT PLATE FOR THERMAL NANOIMPRINT LITHOGRAPHY (나노임프린트 장비용 대면적 열판 열설계를 위한 수치 연구)

  • Park, G.J.;Lee, J.J.;Kwak, H.S.
    • Journal of computational fluids engineering
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    • v.21 no.2
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    • pp.90-98
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    • 2016
  • A numerical study is conducted on thermal performance of a large-area hot plate specially designed as a heating and cooling tool for thermal nanoimprint lithography process. The hot plate has a dimension of $240mm{\times}240mm{\times}20mm$, in which a series of cartridge heaters and cooling holes are installed. The material is stainless steel selected for enduring the high molding pressure. A numerical model based on the ANSYS Fluent is employed to predict the thermal behavior of the hot plate both in heating and cooling phases. The PID thermal control of the device is modeled by adding user defined functions. The results of numerical computation demonstrate that the use of cartridge heaters provides sufficient heat-up performance and the active liquid cooling in the cooling holes provides the required cool-down performance. However, a crucial technical issue is raised that the proposed design poses a large temperature non-uniformity in the steady heating phase and in the transient cooling phase. As a remedy, a new hot plate in which heat pipes are installed in the cooling holes is considered. The numerical results show that the installation of heat pipes could enhance the temperature uniformity both in the heating and cooling phases.

A Study on the Historical Trend Analysis of Korean Home Furniture Design (Focused on After 1980s) (한국 가정용 가구디자인의 시대적 경향분석에 관한 연구 (80년대 이후 중심으로))

  • In mi-ae
    • Journal of the Korea Furniture Society
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    • v.16 no.1
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    • pp.53-69
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    • 2005
  • This research has a significant meaning to observe and understand the historical condition of a furniture industry and the characteristics of Korean home furniture's formation, ability, skill and materials from 1980s when there were an economic growth and a historical development of Korean home furniture occurred to present days. During 1980s, there was an automatic system available and has enforced and settled the standards on its quality and price in a furniture industry. Also, there was a big trend of black furniture as well as an entrance of corporation and high glossy furniture due to technical cooperation from Europe. In 1990s, there was an entrance of furniture which various techniques was applied due to a high development of the materials and skills, and also various sizes of height and weight and enlargement of acceptance function using highly-technological hardware. After 2000 and now, pro-environmental products is embossed in the Korean home furniture where they added a public issue which is the concept of well being, and A.I and sub material has been pro-environment. There also was a natural unity between nature and technology because of increased usage of trees with its natural patterns, metals, and glasses. For the future development of home furniture design, This problem should be promptly recognized that current home furniture designs are now on the verge of being lack of originality and are just following the market demand and recent trend as it is. Then, there should be a development of its specialized, detailed, unique design as well as a development of advanced materials, production management, distribution, and so on, and carrying out a diversified research continuously. There also should be a systematic education, which is necessary for training specialists to lead the Korean home furniture design industry as well as preparing a basic level for the future without a negligence.

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An Investigation of Icing Effects on the Aerodynamic Characteristics of KC-100 Aircraft (KC-100 항공기의 표면발생 Icing 형상 및 공력 영향성 연구)

  • Jung, Sung-Ki;Lee, Chang-Hoon;Shin, Sung-Min;Myong, Rho-Shin;Cho, Tae-Hwan;Jeong, Hoon-Hwa;Jung, Jae-Hong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.6
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    • pp.530-536
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    • 2010
  • In-flight icing is a critical technical issue for aircraft safety and, in particular, ice accretions on aircraft surfaces can drastically impair aerodynamic performances and control authority. In order to investigate icing effects on the aerodynamic characteristics of KC-100 aircraft, a state-of-the-art CFD code, FENSAP-ICE, was used. A main wing section and full configuration of KC-100 aircraft were considered for the icing analysis. Also, shapes of iced area were calculated for the design of anti-/de-icing devices. The iced areas around leading edge of main wing and horizontal tail wing were observed maximum 7.07% and 11.2% of the chord length of wing section, respectively. In case of wind shield, 16.7% of its area turned out to be covered by ice. The lift of KC-100 aircraft were decreased to 64.3%, while the drag was increased to 55.2%.

3D Graphic Interface Design for TV using Behavior and Attribute Analysis (행위와 속성 분석을 통한 TV 의 3D 그래픽 인터페이스 디자인 연구 -실생활과 접목된 필연적인 인터페이스 구현을 위한 방법론)

  • Shim, Jae-Hee;Kim, Uni-Young;Kim, Ji-Hea;Lee, Hyung-Nam;Jang, Sae-Hun
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.996-1000
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    • 2009
  • There can be three objectives why we apply 3D graphics in TV interface. First, inevitable usability. 3D space is the most inevitable way for product-user interaction deviating from the current aesthetic or technical purpose of use. Second, enhance emotional satisfaction by merging interface into real life. Beyond digilog(analog+digital), we wanted users to naturally use the interface as if they are using everyday objects. And in order to do this properly, we analyzed the behaviors of users how they use their everyday objects and then analyzed the attributes beyond each behavior. Third, capaticy for enourmous contents of the incorporated TV. The most efficient way to display enormous amounts of contents in a limited screen is 3D. And that 3D space gives us almost unlimited capacity in accepting contents. Now to conclude, using 3D graphics for TV interface has significance in many ways but the issue is how we can maintain the 3D effects while customizing them into real products.

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Control of the Bidirectional DC/DC Converter for a DC Distribution Power System in Electric Vehicles (전기 자동차의 DC 배전 시스템을 위한 양방향 DC/DC 컨버터의 제어)

  • Chang, Han-Sol;Lee, Joon-Min;Kim, Choon-Tack;La, Jae-Du;Kim, Young-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.7
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    • pp.943-949
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    • 2013
  • Recently, an electric vehicle (EV) has been become a huge issue in the automotive industry. The EV has many electrical units: electric motors, batteries, converters, etc. The DC distribution power system (DPS) is essential for the EV. The DC DPS offers many advantages. However, multiple loads in the DC DPS may affect the severe instability on the DC bus voltage. Therefore, a voltage bus conditioner (VBC) may use the DC DPS. The VBC is used to mitigate the voltage transient on the bus. Thus, a suitable control technique should be selected for the VBC. In this research, Current controller with fixed switching frequency is designed and applied for the VBC. The DC DPS consist of both a resistor load and a boost converter load. The load variations cause the instability of the DC DPS. This instability is mitigated by the VBC. The simulation results by Matlab simulink and experimental results are presented for validating the proposed VBC and designed control technique.

Trend on the Recycling Technologies for Used Fat and Vegetable Oil as Monomers by the Patent and Paper Analysis (특허(特許)와 논문(論文)으로 본 동식물폐유지(動植物廢油脂) 모노머화 재활용(再活用) 기술(技術) 동향(動向))

  • Kim, Young-Wun;Yoon, Byung-Tae;Cho, Bong-Gyoo;Cho, Young-Ju
    • Resources Recycling
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    • v.22 no.1
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    • pp.72-79
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    • 2013
  • There is increasing interest to the development of environmental friendly products related global environment and health issue and it is very important technology for recycling contained hazardous substance that occur due to oxidation during used oils and fats of vegetable and animal to eco-friendly products. In this study, papers and patents for recycling technologies of used fat and vegetable oil as monomers were analyzed. The range of search was limited in the open patents of USA (US), European Union (EP), Japan (JP), Korea (KR) and SCI journals from 1976 to 2012. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals were analyzed by the years, countries, companies, and technologies. Such pretreatment purification, polymerization for monomer, and polymer manufacturing technology were ahead of the United States.

The Distributed Transport Platform for Real-Time Multimedia Stream (실시간 멀티미디어 스트림을 위한 분산 전송 플랫폼)

  • 송병훈;정광수;정형석
    • Journal of KIISE:Information Networking
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    • v.30 no.2
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    • pp.260-269
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    • 2003
  • The traditional distributed object middleware platform is not suitable for the transmission of stream data, because RPC(Remote Procedure Call)-based message transmission have a great overhead. Therefore, the OMG(Object Management Group) proposes the AV(Audio and Video) stream reference model for streaming on the distributed object middleware platform. But, this reference model has not a detail of implementation. Particularly it also has not congestion control scheme for improvement of network efficiency on the real network environment. It is a very important and difficult technical issue to provide the stream transmission platform with advanced congestion control scheme. In this paper, we propose an architecture of a distributed stream transport platform and deal with the design and implementation concept of our proposed platform. Also, we present a mechanism to improve streaming utilization by SRTP(Smart RTP). SRTP is our proposed TCP-Friendly scheme.