• Title/Summary/Keyword: Super-station

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A Study on the Channel Handover Method for Super Wi-Fi Service Continuity in TV White Spaces (Super Wi-Fi 환경에서 서비스 연속성을 위한 끊김없는 채널이동 방안 연구)

  • Kim, Myeongyu;Jeon, Youchan;Park, Sangwon;Park, Jinwoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37B no.11
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    • pp.1050-1057
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    • 2012
  • Super Wi-Fi is a newly emerging wireless Internet technology, which constitutes Wi-Fi networks using TV white space. A key technical challenge in the Super Wi-Fi applications is how to provide a seamless Internet service even when a Super WiFi user should give up the channel in use to the active incumbent user which is activated in the same service area, preventing from the service continuity in Super Wi-Fi. In this paper, we propose a channel handover method to support service continuity of Super Wi-Fi, in which an AP selects a new operational channel and provides the channel information for MSs. Therefore, the AP and the MSs can carry out seamless handover for Super Wi-Fi service. A performance evaluation shows that the proposed scheme is superior to the conventional Wi-Fi in channel mobility delay.

Some Nutritional Studies on Some Bulgarian Silkworm (Bombyx mori L.) Hybrids Reared in Northern Greece

  • Kipriotis, Evripidis;Grekov, Dimitar
    • International Journal of Industrial Entomology and Biomaterials
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    • v.1 no.2
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    • pp.155-159
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    • 2000
  • In the spring silkworm rearing period of year 1998, some nutritional aspects were studied in the Agricultural Research Station of the Komotini town in Greece, to investigate the feeding behaviour of some Bulgarian silkworm hybrids, suitable for spring rearing, during the fourth and fifth instal under the local climatic conditions. The silkworms were fed by locally cultivated Japanese Kinriu mulberry (Morus alba L.) variety leaves. Eight Bulgarian hybrids had been used, namely Vratza-53xVratza-52, Ukraine-20xVratza-53, Super 1xHessa 2, Merefa 2xVratza 35, as well as their reciprocal crosses. The studies showed out a remarkably higher feed intake and feed utilization by the hybrids Hessa 2xSuper-1, Merefa 2xVratza 35 and Vratza-52xVratza-53. The same hybrids showed an efficient food utilization by means of daily growths cocoon shell ratio and raw silk output. In terms of food to silk conversion efficiency Hessa 2xSuper-1 hybrid gave the best results. Larval stage duration for fourth and fifth instar was not affected by feed intake and utilization. All hybrids showed a good adaptation to the local environment and their feeding performance was equal to the international existing standards. All calculated parameters were found to be around the mean values of other up to date presented results and thus considered as acceptable for the needs of the local production.

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The Core Technical Trends of TESLA EV(Electric Vehicle) Motors (테슬라(TESLA) 전기자동차 핵심 기술동향)

  • Bae, Jin-Yong;Kim, Yong
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.5
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    • pp.414-422
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    • 2017
  • This paper reviews the core technical trends of TESLA EV Motors. The TESLA EV Motors is explosively popular with a considerable recharging infrastructure, a wide 17-[inch] touch display, 417 [HP], and 378 [km] going distance. The object of this study analyzes the body appearance, motor and, battery cooling system, battery arrangement, battery management system, super charging station, power electronics, and induction motor.

Effect of the building envelope on heating and cooling load in super tall building considering the meteorological changes with height (높이별 기상변화를 고려한 초고층 건축물의 외피종류별 냉난방 부하특성 분석)

  • Choi, Jong-Kyu;Kim, Yang-Soo;Song, Doo-Sam
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.337-344
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    • 2012
  • Today, the number of super tall buildings are under construction or being planed in Middle East and Asian Countries. For example the burj Khalifa, the tallest building in the world, is completed in 2008 and the height of that is about 800m. Also, Lotte World Tower is under construction in Korea. External environmental conditions such as wind speed, air temperature, humidity and solar radiation around the super tall building differs according to the building height due to the vertical micro climate change. However, the meteorological information used for AC design of building is obtained typically from standard surface meterological station data(~2m above the ground). In this paper the effect of the building envelope on heating and cooling load in super tall building considering the meteorological changes with height was analyzed with simulation method. As results of this research, the guideline to select the building envelop alternatives for super tall building will be suggested in this paper.

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Effects of Atmospheric Turbulence on the Optical Satcom Link between Stratospheric Sky Station and Earth Station (대기교란이 지구국과 성층권 위성간 광 위성통신시스템에 미치는 영향에 관한 연구)

  • Jung, Jin-Ho
    • Journal of IKEEE
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    • v.1 no.1 s.1
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    • pp.47-54
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    • 1997
  • Today's communication needs the super high-speed data transmission system to send many data rapidly, correctly, and simultaneously because of the increase of internet use, the demand of multimedia service and so on. Before long, the super high data service will be offered us by a satellite called platform which will be located at stratosphere of 20[km]over earth. It is possible to build the optical wireless communication networks which have the high data-tarrying capacity because this system use a laser. But, there are many problems to overcome because it make use of the atmospheric space as transmission channel. In this paper, therefore, we study up on the relations of data rates, bit error rates, and turbulent effects of atmosphere to present the effects of atmosphere to present the effects of atmospheric turbulence on the optical satcom link.

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In-construction vibration monitoring of a super-tall structure using a long-range wireless sensing system

  • Ni, Y.Q.;Li, B.;Lam, K.H.;Zhu, D.P.;Wang, Y.;Lynch, J.P.;Law, K.H.
    • Smart Structures and Systems
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    • v.7 no.2
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    • pp.83-102
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    • 2011
  • As a testbed for various structural health monitoring (SHM) technologies, a super-tall structure - the 610 m-tall Guangzhou Television and Sightseeing Tower (GTST) in southern China - is currently under construction. This study aims to explore state-of-the-art wireless sensing technologies for monitoring the ambient vibration of such a super-tall structure during construction. The very nature of wireless sensing frees the system from the need for extensive cabling and renders the system suitable for use on construction sites where conditions continuously change. On the other hand, unique technical hurdles exist when deploying wireless sensors in real-life structural monitoring applications. For example, the low-frequency and low-amplitude ambient vibration of the GTST poses significant challenges to sensor signal conditioning and digitization. Reliable wireless transmission over long distances is another technical challenge when utilized in such a super-tall structure. In this study, wireless sensing measurements are conducted at multiple heights of the GTST tower. Data transmission between a wireless sensing device installed at the upper levels of the tower and a base station located at the ground level (a distance that exceeds 443 m) is implemented. To verify the quality of the wireless measurements, the wireless data is compared with data collected by a conventional cable-based monitoring system. This preliminary study demonstrates that wireless sensing technologies have the capability of monitoring the low-amplitude and low-frequency ambient vibration of a super-tall and slender structure like the GTST.

A Multithreaded Architecture for the Efficient Execution of Vector Computations (벡타 연산을 효율적으로 수행하기 위한 다중 스레드 구조)

  • Yun, Seong-Dae;Jeong, Gi-Dong
    • The Transactions of the Korea Information Processing Society
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    • v.2 no.6
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    • pp.974-984
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    • 1995
  • This paper presents a design of a high performance MULVEC (MULtithreaded architecture for the VEctor Computations), as a building block of massively parallel Processing systems. The MULVEC comes from the synthesis of the dataflow model and the extant super sclar RISC microprocesso r. The MULVEC reduces, using status fields, the number of synchronizations in the case of repeated vector computations within the same thread segment, and also reduces the amount of the context switching, network traffic, etc. After be nchmark programs are simulated on the SPARC station 20(super scalar RISC microprocessor)the performance (execution time of programs and the utilization of processors) of MULVEC and the performance(execution time of a program) of *Taccording the different numbers of node are analyzed. We observed that the execution time of the program in MULVEC is faster than that in * T about 1-2 times according the number of nodes and the number of the repetitions of the loop.

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Optimal Design of Urban MICROGRID using Economical Analysis Program (경제성분석 프로그램을 이용한 도심형 마이크로그리드 최적 설계)

  • Seung-Duck, Yu;SungWoo, Yim;Youseok, Lim;SungWook, Hwang;JuHak, Lee
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.2
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    • pp.69-72
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    • 2022
  • This paper actually investigates the load on major large-scale buildings in the downtown area, examines the economic feasibility of installing PV and ESS in a microgrid target building, and evaluates whether an electric vehicle capable of V2G through two buildings is effective as an economical analysis program (HOMER) was analyzed using. It is economical to install a mixture of ESS rather than using the whole PV, and it is shown that if there is an electric vehicle using the V2G function of EV, there is an economic effect to replace the PV. So that Incentives and policies are needed to replace a large area of PV and utilize the existing parking lot to lead EV as a resource of the microgrid. Currently, P2X technology that stores power as ESS or converts it to other energy to control when surplus renewable energy occurs in large-capacity solar power plants and wind farms, etc. This is being applied, and efforts are being made to maintain the stability of the system through the management of surplus power, such as replacing thermal energy through a heat pump. Due to the increase in electric vehicles, which were recognized only as a means of transportation, technologies for using electric vehicles are developing. Accordingly, existing gas stations do not only supply traditional chemical fuels, but electricity, and super stations that also produce electricity have appeared. Super Station is a new concept power plant that can produce and store electricity using solar power, ESS, V2G, and P2G. To take advantage of this, research on an urban microgrid that forms an independent system by tying a large building and several buildings together and supplies power through a super station around the microgrid is in full swing.

TC & R Communication Link Performance Analysis of Geostationary Satellite Employing PCM/PSK/PM on Super Synchronous Transfer Orbit (PCM/PSK/PM 방식을 사용하는 정지궤도 위성의 슈퍼 천이 궤도에서 S-Band TC & R 통신 링크 성능 분석)

  • Lee, Sun-Ik;Yeom, Kyung-Whan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.11
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    • pp.1142-1155
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    • 2014
  • The classical PCM/PSK/PM scheme has been commonly used for TC & R applications between satellites and ground stations in the S-band. We analyzed TC & R link performance between ground station and the geostationary satellite which employs PCM/PSK/PM, when the satellite are particularly on the Super Synchronous Transfer Orbit(SSTO). The satellite parameters on SSTO are assumed to be those operating on the geostationary orbit, considering heritage aspect. In the uplink, the results shown indicate that sufficient margins over 3 dB are obtained when the EIRP of ground station is greater than 65 dBW. The down link performance is of great interest. By adjusting the telemetry modulation index and ranging modulation index, we could obtain the required margin of 3.0 dB in the down link, and find out the minimum G/T of ground station. In conclusion, the previously operated ground stations during LEOP at COMS launch, can be operational when GEO injection is made using SSTO(65,000 km and 70,000 km).