• Title/Summary/Keyword: CBRS

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Frequency Sharing with FSS Earth Stations for CBRS Services (CBRS 서비스를 위한 FSS 지구국 주파수 공동사용)

  • Kang, Young-Heung
    • Journal of Advanced Navigation Technology
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    • v.23 no.6
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    • pp.507-514
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    • 2019
  • Federal communications commissions (FCC) has announced the first set of rules for 3.5 GHz (3,550 - 3,700 MHz) band used Navy radar and fixed satellite service (FSS) earth stations as primary service to sharing for citizen broadband radio service (CBRS) enable development of relatively low powered network technologies like small cells. Since CBRS sharing technique based on the 3-tiered spectrum access system (SAS) is able to protect the higher tiered users from harmful interference from lower tiered users, it has been considered actively to be introduced in Korea. However, 3.5 GHz band had been already allocated to the 5G services in Korea, the sharing studies have been carried out for 3,700 - 5,000 MHz, As the result, the 3.8 GHz (3,800 - 3,900 MHz) band used for only FSS system is able to be sharing, and an introduction of CBRS has been proposed in Korea by analyzing the interference to the FSS earth stations.

Mother-Child Interactions in Preschool Children Who Stutter (학령전기 말더듬아동의 어머니-아동 상호작용 행동특성)

  • Kim, Jeong-Mee;Sim, Hyun-Sub;Lee, Eun-Ju
    • Speech Sciences
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    • v.12 no.3
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    • pp.35-48
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    • 2005
  • This study was to examine the relationship between maternal interactive behaviors and stuttering behaviors in preschool children who stutter. Participants were twenty-four children who stutter and their mothers. For the purpose of the current study, 5$\sim$10 minutes of 50 minutes videotaped scenes originally collected to develop fluency assessment instrument were re-videotaped. They included mother-child interactions during playing with toys and reading book situations. Mothers-children interactive behaviors were assessed with Maternal Behavior Rating Sroles(MBRS) and Child Behavior Rating Scales (CBRS). And children's stuttering were assessed with Paradise-Fluency Assessment(P-FA). The results were as follows: 1) the maternal interactive behavior did not significantly differ depending on situations, but scores of maternal responsive factor were higher in the play situation than in the reading situation. 2) Maternal responsiveness might influence on promoting the children's pivotal behavior with children who stutter. And 3) the level of maternal responsiveness was the predictor of children's stuttering behaviors. The therapeutic implication of the results were discussed.

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Spectrum Policy and Standardization Trends on Frequency Sharing (주파수 공동사용 정책 및 표준화 동향)

  • Kang, K.M.;Park, J.C.;Choi, S.N.;You, S.J.;Hwang, S.H.;Byun, W.J.
    • Electronics and Telecommunications Trends
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    • v.33 no.3
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    • pp.1-10
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    • 2018
  • This article presents spectrum sharing policy trends both overseas and domestically. The Federal Communications Commission recently adopted rules for the commercial use of a 150 MHz bandwidth at 3.55 to 3.7 GHz, which has been utilized for defense and satellite services. This frequency band for spectrum sharing is called the citizens broadband radio service (CBRS) band. In Europe, the related regimes for licensed shared access application at 2.3 to 2.4 GHz has been organized, and interface standardization for sharing frequency information has been completed. In Korea, efforts are being made to establish spectrum-sharing policies to improve the efficiency of the frequency utilization. This article also introduces both the IEEE 802 local area network/metropolitan area network and 3GPP standardization activities with regard to frequency sharing technologies. To effectively solve the spectrum-sharing problem in IEEE 802, standardization activities on the CBRS and the mid-band (3.7-24 GHz) are underway. 3GPP is currently developing the standardization of a licensed assisted access technology, which extends mobile communication services provided in the licensed band to unlicensed bands.

Active Adjustment: An Approach for Improving the Search Performance of the TPR*-tree (능동적 재조정: TPR*-트리의 검색 성능 개선 방안)

  • Kim, Sang-Wook;Jang, Min-Hee;Lim, Sung-Chae
    • The KIPS Transactions:PartD
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    • v.15D no.4
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    • pp.451-462
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    • 2008
  • Recently, with the advent of applications using locations of moving objects, it becomes crucial to develop efficient index schemes for spatio-temporal databases. The $TPR^*$-tree is most popularly accepted as an index structure for processing future-time queries. In the $TPR^*$-tree, the future locations of moving objects are predicted based on the CBR(Conservative Bounding Rectangle). Since the areas predicted from CBRs tend to grow rapidly over time, CBRs thus enlarged lead to serious performance degradation in query processing. Against the problem, we propose a new method to adjust CBRs to be tight, thereby improving the performance of query processing. Our method examines whether the adjustment of a CBR is necessary when accessing a leaf node for processing a user query. Thus, it does not incur extra disk I/Os in this examination. Also, in order to make a correct decision, we devise a cost model that considers both the I/O overhead for the CBR adjustment and the performance gain in the future-time owing to the CBR adjustment. With the cost model, we can prevent unusual expansions of BRs even when updates on nodes are infrequent and also avoid unnecessary execution of the CBR adjustment. For performance evaluation, we conducted a variety of experiments. The results show that our method improves the performance of the original $TPR^*$-tree significantly.

Study on the Introduction of Spectrum Policy to Revitalize the Domestic Spectrum Sharing (국내 주파수 공동사용 활성화를 위한 정책 도입방안 연구)

  • Choi, Joo-Pyoung;Lee, Won-Cheol
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.3
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    • pp.200-213
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    • 2018
  • Herein, we survey the current state of the recent legal revision of the Citizens Broadband Radio Service, a type of city spectrum-sharing service used in the United States of America, and the introduction of spectrum sharing in the frequency ranging from 3.8~4.2 GHz, based on the United Kingdom framework for spectrum sharing. Specifically, the subjects of topical interest, including the radio station licensing of the spectrum-sharing service system face-to-face multitier user structure, regional frequency allocation, and applicable service types, are discussed. Furthermore, factors to be considered while selecting candidate channels for joint use are suggested, emphasizing their importance for introducing spectrum sharing in Korea and revitalizing the related industrial sectors. In addition, methods of introducing a radio station license system for spectrum sharing, techniques of introducing incentive auctions, and the types of services where spectrum sharing is applicable are discussed.

A direction of warfighting experiments for a scientific combat Development (과학적 전투발전을 위한 전투실험 발전 방향)

  • Chung, Choon-Il;Lee, Myeong-Woo
    • Journal of National Security and Military Science
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    • s.5
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    • pp.351-392
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    • 2007
  • Combat Development is process of studying and developing concept, doctrine, weapon systems, organization and training for the improvement of combat capability to be ready present and future warfare. The combat development domain consists of 6 fields Doctrine, Organization, Material, Training, Personnel, and Facilities. The cornerstones of combat development are "How to prepare" and "How to fight" in the future warfare. ROK- TRADOC(Republic of Korea Army Training and Doctrine Command) has implemented combat development that applies CBRS (Concept-Based Requirements System) and "Vision - Capstone concept - operating and functional concept - FOC(Future Operational Capabilities) Requirements". To prepare for the possibility or new types or wars in the future, the creation of new concept and system is essential. Though verification with various instruments, combat power can be secured and exhibited. Combat development by empirical mind estimation means that is no longer relevant.To prepare combat development based on scientific analysis, there is a need for powerful engineering analysis and verification, in order to prepare for uncertain and diverse future battlefield environments. In this thesis, warfighting experiment is essential ways and means to pursue the scientific combat development ; investigated tendency of combat development environment, and analyzed diversification aspects of possible future warfare. In conclusion, concept of campaign experiment and role is the conerstone of scientific combat development; and lays out the roadmap of all affecting components to its development.

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Comparison of Physicochemical Properties of Korean and Chinese Red Bean Starches (한국산 및 중국산 팥 전분의 이화학적 특성 비교)

  • Kim, Choong-Ki;Oh, Byung-Hyun;Na, Jong-Min;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.35 no.4
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    • pp.551-555
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    • 2003
  • The physicochemical properties of starches from Korean and Chinese red bean were investigated. Korean red bean starch (KRBS) contained lower water content, but higher crude fat and carbohydrate content than those of Chinese red bean starch (CRBS). The round shape of starch granules from Korean and Chinese red bean was observed. The granule size of KRBS was smaller than that of CRBS. The whiteness of KRBS (87.22%) was significantly higher than that (86.16%) of CBRS. X-ray diffraction patterns between KRBS and CRBS were not significantly different, resulting in showing C type. There was significant difference in amylose content between KRBS and CRBS. The blue value of KRBS was 1.02, which was higher than that of CRBS. Swelling power of KRBS was higher up to $75^{\circ}C$ than that of CRBS, but then decreased. Solubility showed the same pattern as the swelling power. Our findings suggest that Korean red bean has better quality than Chinese red bean in terms of the physicochemical properties.