• Title/Summary/Keyword: Coexistence

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A Coexistence Mitigation Scheme in IEEE 802.15.4-based WBAN (IEEE 802.15.4 기반 WBAN의 공존 문제 완화 기법)

  • Choi, Jong-hyeon;Kim, Byoung-seon;Cho, Jin-sung
    • Journal of Internet Computing and Services
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    • v.16 no.3
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    • pp.1-11
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    • 2015
  • WBAN(Wireless Body Area Network) operating around the human body aims at medical and non-medical service at the same time. and it is the short-range communication technology requiring low-power, various data rate and high reliability. Various studies is performing for IEEE 802.15.4, because IEEE 802.15.4 can provide high compatibility for operate WBAN among communication standard satisfiable these requirements. Meanwhile, in the case of coexisting many IEEE 802.15.4-based WBAN, signal interference and collision are the main cause that is decreasing data reliability. but IEEE 802.15.4 Standard does not consider about coexistence of many networks. so it needs improvement. In this paper, To solve about this problem, identify coexistence problem of IEEE 802.15.4-based WBAN by preliminary experiments. and propose a scheme to mitigate the reliability decrease at multiple coexistence WBAN. The proposed scheme can be classified in two steps. The first step is avoidance to collision on the CFP through improving data transmission. The second step is mitigation collision through converting channel access method. Proposed scheme is verified the performance by performing comparison experiment with Standard-based WBAN.

Outage Probability and Throughput Management Using CoMP under the Coexistence of PS-LTE and LTE-R Networks (안전망과 철도망 공존환경에서 협력통신을 이용한 아웃티지 및 수율 관리)

  • Lim, WonHo;Jeong, HyoungChan;Ahmad, Ishtiaq;Chang, KyungHi
    • Journal of Advanced Navigation Technology
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    • v.20 no.6
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    • pp.595-603
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    • 2016
  • In the Republic of Korea, the LTE-based public safety (PS-LTE) network is being built for the 700 MHz frequency band. However, the same bands are also assigned to the LTE-based high-speed railway (LTE-R) network. Therefore, it is essential to utilize the co-channel interference management schemes for the coexistence of two LTE networks in order to increase the system throughput and to reduce the user outage probability. In this paper, we focus on the downlink (DL) system for the coexistence of PS-LTE and LTE-R networks by considering non radio access network (RAN) sharing and LTE-R RAN sharing by PS-LTE users (UEs) to analyze the UE throughput. Moreover, we also utilize the cooperative communications schemes, such as coordinated multipoint (CoMP) for the coexistence of PS-LTE and LTE-R networks in order to reduce the UE outage probability. We categorize the coexistence of PS-LTE and LTE-R networks into four different scenarios, and evaluate the performance of each scenario by the important performance indexes, such as UE average throughput and UE outage probability.

Analysis on the Effects of Interference Mitigation for Ultra-wideband Coexistence with BWA

  • Yoon Young-Keun;Jin Hong-Heon;Choi Ik-Guen
    • Journal of electromagnetic engineering and science
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    • v.6 no.2
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    • pp.117-122
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    • 2006
  • This paper presents the impacts of Ultra-wideband(UWB) applied in the communication applications using frequency band from 3.1 GHz to 10.6 GHz on Broadband Wireless Access(BWA) based on orthogonal frequency division multiplexing(OFDM) using frequency band of 3.5 GHz. It proposes low duty cycle(LDC) for enabling UWB to mitigate strong interference to BWA. The effects of interference mitigation are evaluated and analyzed in the environment of UWB coexistence with BWA. UWB with LDC scheme will be given to bring higher transmit power level corresponding to Federal Communications Commission(FCC) provisional limit for enabling UWB operation at 3.5 GHz bands.

Principles and Directions for Urban-Rural Living Community Movement (도농공동체 운동의 추진방향)

  • Kim, Ho
    • Korean Journal of Organic Agriculture
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    • v.12 no.1
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    • pp.67-80
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    • 2004
  • Farm economy is getting worse because of the free trade trends in agriculture sector and unreasonable application of market economy principles to agricultural products. And The worldwide issues of environmental pollution as well as want of food, water and energy make human future be anxious. In addition, consumers raise questions in argument about safety of foods produced by traditional farming or imported. So I propose the urban-rural living community movement(URLCM) as an alternative plan for sustainable domestic agriculture. URLCM based on environmentally friendly agriculture and community consciousness will be able to solve many of present issues on agriculture and rural society through incessant interchanges between urban and rural community. This URLCM has to be basically founded on principles of symbiosis-coexistence and life circulation. So those that have to be driven forward arc organizing producers and consumer cooperatives, making environmentally friendly rural region and products, combining with consumer cooperatives, training the participants and so forth.

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Spinal Subdural Hematoma Following Cranial Subdural Hematoma : A Case Report with a Literature Review

  • Ji, Gyu Yeul;Oh, Chang Hyun;Chung, Daeyeong;Shin, Dong Ah
    • Journal of Korean Neurosurgical Society
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    • v.54 no.6
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    • pp.515-517
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    • 2013
  • Coexistence of cranial and spinal subdural hematomas is rare and only a few cases have been reported in the literature. Herein, we report a case of cranial and spinal subdural hematomas after previous head trauma. As the pathogenesis of simultaneous intracranial and spinal subdural hematoma yet remains unclear, we developed an alternative theory to those proposed in the literature for their coexistence, the migration of blood through the subdural space.

A Case of Extraadrenal Pheochromocytoma Showed a Transient Oral Captopril Test Positive Result (Captopril 검사 양성반응을 보인 부신외 갈색세포종 (Extraadrenal Pheochromocytoma) 1예)

  • Lee, In-Bum;Lee, Du-Ha;Oh, Tae-Hi;Park, Jong-Seon
    • Journal of Yeungnam Medical Science
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    • v.14 no.2
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    • pp.474-482
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    • 1997
  • There have been some case reports of the coexistence of extraadrenal pheochromocytoma and renal artery stenosis. Some reporters proposed that their coexistence may be associated through a common pathophysiological mechanism mediated by catecholamine secretion. Also some noted that trasient renal artery stenosis due to a spasm was induced by the catecholamines released from pheochromacytoma. We report a case of left paraaortic extraadrenal pheochromacytoma that had a transient oral captopril test positive result. After 5 days ${\alpha}$-antagonist reduced the vasospastic response of catecholamines. After surgical removal of the tumor, plasma catecholamines and urinary vanillyhnandelic acid concentrations as well as the blood pressure level, were restored to normal.

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