• 제목/요약/키워드: 4G architecture

검색결과 366건 처리시간 0.025초

국내 휴양시설의 장애인 편의시설 실태분석에 관한 연구 (An analysis of current Barrier-Free facilities in Leisure Building)

  • 성기창
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제16권4호
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    • pp.25-32
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    • 2010
  • Despite the growing interest in recreation as one of the ways to maintain physical and mental health in modern society, access to leisure facility is an issue for individuals with disabilities. This paper identifies inaccessible features to propose the ways to promote participation and usage of the leisure facilities for individuals with disabilities. A survey of individuals with disabilities is conducted to determine preferred leisure facilities depending on types of disabilities. The result of this survey is used to evaluate current condition of regulated National leisure facility and forest, which include barrier-free facilities (e.g. interconnecting zones, interior spaces, lavatories and other facilities), signage, approachable information kiosks, emergency egress, and detectable warnings. The common issues (e.g. guiding mechanism, accessible route, safety factors, and barrier-free facilities/services) in various types of recreational facilities (e.g. forest recreational center, spa and hot springs, Amusement Park, ski resort) were identified and analyzed.

바다 매립지 곰솔 이식후 생장특성(I) - 세근 공간적 분포를 중심으로 - (Growth Characteristics of Pinus thunbergii Parl. after Replanting in Reclaimed from the Sea( I ) - On the Spatial Distribution of Fine Root Phytomass -)

  • 김도균;곽영세
    • 한국조경학회지
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    • 제31권6호
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    • pp.77-84
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    • 2004
  • This study was carried out to analyze the vertical and horizontal distribution of fine root biomass of Pinus thunbergii transplanted in reclaimed land from the sea near Gwangyang Bay. The fine-root biomass according to 6 planting ground types were as follows: 98.5 g DM/$m^2$ for P2, 51.1 g DM/$m^2$ for P6, 47.8 g DM$m^2$ for P5, 44.6 g DM/$m^2$ for P3, 38.2 g DM/$m^2$ for P4, 31.8 g DM/$m^2$ for Pl, respectively. The vertical distribution of fine root biomass decreased at descending soil depths of the 6 mounding types. Fine root biomass was 31∼55% in the topsoil of 20cm depth. Fine root biomass that were related to the Spatial distance from the nearest tree were unevenly distributed horizontally in 6 stands. distribution patterns of fine root biomass were closely related to soil hardness and alkalic cation (Ca++, Mg++, Na+, K+) concentrations. Therefore, in order to have good condition for the growth of landscaping plants, we suggest that there is a need for the construction of planting grounds as well as a need for soil improvement in bad soil environments.

대학시설의 녹색건축인증 등급별 득점경향에 대한 조사연구 (Study on the Trend Analysis according to Grade of G-SEED for University Facilities)

  • 류수훈;김홍민
    • 교육시설 논문지
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    • 제25권6호
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    • pp.3-10
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    • 2018
  • This study analyzes the average acquisition ratio between the 1st and 4th grade and the distribution and characteristics of the acquisition between the assessment items based on the case of Green Building Certification System(GBCS) for the educational facilities on the university campus. By evaluating the difference between the best scored grade (Green 1st Grade) and the general grade (Green 4th Grade), we classified the cases where the difference between grades with little or big difference. By doing this, we were able to analyze the trend that were difficult to distinguish between difficult to score and an easy task. G-SEED should be used not only as a formal system for certifying certification, but also to provide environmentally-friendly technology for buildings as well as meeting market needs. To do this, it is necessary to further refine the evaluation criteria. In addition, it is necessary to establish a qualitative evaluation system by providing detailed criteria for items that are not distinguishable among grades. It is expected that this study will be used to improve the detailed evaluation items by analyzing trends in the average acquisition rate presented in this study.

3G LTE 및 SAE 네트워크에서 키 관리 방법에 관한 연구 (The Study on The Key Management Mechanism on 3G LTE and SAE)

  • 정영준;윤승환;이옥연;임종인
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2008년도 동계학술대회
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    • pp.99-102
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    • 2008
  • 차세대 이동 통신 서비스 4G는 이동 중 100Mbps, 정지 중 1Gbps급 전송 속도를 제공하는 미래 무선 통신 기술이다. 이것은 현재 상용서비스가 이뤄지고 있는 3G HSDPA(High Speed Packet Access)의 전송속도 14Mbps에 비해 10~100배까지 빠른 속도로 무선 인터넷이 가능함으로 유선으로 인터넷을 사용할 필요가 없어진다. 현재 4G 기술로 진화하기 위한 중간 단계로써 ITU-R, 3GPP, 3GPP2, IEEE 등 세계 각국의 표준 및 기술 단체에서 새로운 무선 이동 통신 기술을 제안하고 있다. 이 중에서 2G의 GSM과 3G의 비동기식 기술 WCDMA의 진화 기술인 3GPP LTE(Long Term Evolution) 및 SAE(System Architecture Evolution)가 유력한 4G 이동 통신 기술 후보로 평가 받고 있다. 본 논문에서는 4G 기술로 주목 받고 있는 3GPP LTE 및 SAE 네트워크에서 3G 시스템 보다 진화된 서비스를 제공하기 위한 목적으로 논의되고 있는 일반적인 요구사항과 이를 만족시키기 위한 기술에 대하여 알아본다. 또한 LTE 표준화와 병행하여 네트워크의 구조를 결정하는 SAE의 구성요소와 프로토콜 구조를 소개하고 LTE 및 SAE 네트워크의 보안위협과 안전한 통신을 위한 키 관리 방법에 대하여 논의한다.

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Key Challenges of Mobility Management and Handover Process In 5G HetNets

  • Alotaibi, Sultan
    • International Journal of Computer Science & Network Security
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    • 제22권4호
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    • pp.139-146
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    • 2022
  • Wireless access technologies are emerging to enable high data rates for mobile users and novel applications that encompass both human and machine-type interactions. An essential approach to meet the rising demands on network capacity and offer high coverage for wireless users on upcoming fifth generation (5G) networks is heterogeneous networks (HetNets), which are generated by combining the installation of macro cells with a large number of densely distributed small cells Deployment in 5G architecture has several issues because to the rising complexity of network topology in 5G HetNets with many distinct base station types. Aside from the numerous benefits that dense small cell deployment delivers, it also introduces key mobility management issues such as frequent handover (HO), failures, delays and pingpong HO. This article investigates 5G HetNet mobility management in terms of radio resource control. This article also discusses the key challenges for 5G mobility management.

Pre-deposition of iron-based adsorbents on the removal of humic acid using ultrafiltration and membrane fouling

  • Tian, Hailong;Sun, Lihua;Duan, Xi;Chen, Xueru;Yu, Tianmin;Feng, Cuimin
    • Membrane and Water Treatment
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    • 제9권6호
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    • pp.473-480
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    • 2018
  • The effect of three iron-based adsorbents pre-depositing on ultrafiltration membrane for humic acid (HA) removal and membrane fouling was investigated. The result showed that pre-depositing adsorbents on membrane could not only reduce membrane fouling but also enhance HA removal. The flux was related to the adsorbent dosage and the optimal dosage for pre-deposition was $35.0g/m^2$. The dissolved organic carbon (DOC) removal of HA was 38.3%, 67.3% and 41.1% respectively when pre-deposited $35.0g/m^2$ $FeO_xH_y$, $MnFe_2O_4$ and $Fe_3O_4$ on membrane. Different adsorption effect of adsorbents on HA contributed to increasing of the flux at different level. Zeta potential of three adsorbents all decreased after adsorbed HA. The adsorption capacity of the three adsorbents was $FeO_xH_y$ > $MnFe_2O_4$ > $Fe_3O_4$. Atomic Force Microscopy (AFM) measurement showed the thickness of pre-deposition layers formed by different adsorbents was different. The scanning electron microscope (SEM) detection showed the morphology and compactness of pre-deposition layers formed by different adsorbents was different.

Design and Implementation for Seamless Multimedia Messaging Service over WLAN and CDMA2000

  • kim, Su-Yong;Cho, Yong-Bum;Oh, Chang-Heon;Cho, Sung-Joon
    • Journal of information and communication convergence engineering
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    • 제2권4호
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    • pp.219-223
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    • 2004
  • MMS has been seen as the key application in its entry into the 3G mobile markets. Furthermore, the combination of WLAN and 3G wireless technologies will make MMS service more popular, bringing benefits to both service providers and their customers. To realize seamless MMS service over WLAN and CDMA2000 networks, we design and implement new platform architecture by reusing the existing standards and network elements at the same time. We employ loose coupling approach and Mobile IP approach to propose new platform architecture, interfacing MMSC with many existing components. Based on our platform architecture, we also present seamless MMS delivery implementations that can't be possible within the current MMS reference architecture. This paper will make a contribution for service providers to offer their customers with seamless MMS service over WLAN and CDMA2000 networks.

네트워크 기업의 정보기술 아키텍처 프레임워크 연구 (A Study on ITA(Information Technology Architecture) Framework for Networked Enterprises)

  • 김덕현
    • 한국IT서비스학회지
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    • 제7권4호
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    • pp.45-60
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    • 2008
  • Networked enterprise (NE) is an organization of independent companies that collaborate with each other temporary or permanently for accomplishing common goals. The USA and EU have been developing principal concepts, techniques, and solutions to enhance the competitiveness of traditional industries including small-and-medium enterprises (SMEs). In Korea, however, implementation as well as R&D of NE is very few, which we believe comes from lack of understanding on Its meaning and lack of effective information systems for it. This paper is to suggest an Enterprise Architecture (EA) framework or reference model of NE and an Information Technology Architecture (ITA) of NE. The EA framework will help stakeholder of NE (e,g., policy makers, members of NE, IT solution providers, and researchers) understand structural and behavioral characteristics of NE. The ITA will be used as a guideline of developing information systems for NE that is essential for spreading networked business models, The focus of this paper is not on logical-level design but on conceptual-level modeling of NE. As verification of the suggested framework and architecture is still required, so we'll apply them to various manifestations of NE, e.g., dynamic supply chain, vertical integration of extended enterprises, and P2P-style virtual enterprises.

중금속류 오염 토양 처리를 위한 복합 고화제(lime, DAP, 래들 슬래그) 성능 평가 (Evaluation of the Performance of Multi-binders (lime, DAP and ladle slag) in Treating Metal(loid)s-contaminated Soils)

  • 최지연;신원식
    • 한국환경과학회지
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    • 제26권8호
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    • pp.955-966
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    • 2017
  • Amendment of multi-binders was employed for the immobilization of metal(loid)s in field-contaminated soils to reduce the leaching potential. The effect of different types of multi-binders (lime/diammonium phosphate, diammonium phosphate/ladle slag and lime/ladle slag) on the solidification/stabilization of metal(loid)s (Pb, Zn, Cu and As) from the smelter soil and mine tailing soil were investigated. The amended soils were evaluated by measuring Toxicity Characterization Leaching Procedure (TCLP) leaching concentration of metal(loid)s. The results show that the leaching concentration of metal(loid)s decreased with the immobilization using multi-binders. In terms of TCLP extraction, the mixed binder was effective in the order of lime/ladle slag > diammonium phosphate/ladle slag > lime/diammonium phosphate. When the mixed binder amendment (0.15 g lime+0.15 g ladle slag for 1g smelter soil and 0.05 g lime+0.1 g ladle slag for 1 g mine tailing soil, respectively) was used, the leaching concentration of metal(loid)s decreased by 90%. However, As leaching concentration increased with diammonium phosphate/lime and diammonium phosphate/ladle slag amendment competitive anion exchange between arsenic ion and phosphate ion from diammonium phosphate. The Standard, Measurements and Testing programme (SM&T) analysis indicated that fraction 1 (F1, exchangeable fraction) decreased, while fraction 4 (F4, residual fraction) increased. The increased immobilization efficiency was attributed to the increase in the F4 of the SM&T extraction. From this work, it was possible to suggest that both arsenic and heavy metals can be simultaneously immobilized by the amendment of multi-binder such as lime/ladle slag.

청주시 토양 중 다이옥신 농도 및 특성 (Concentration and Characteristics of PCDDs/DFs in Soil at Cheongju City)

  • 김경수;김교근
    • 대한환경공학회지
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    • 제31권5호
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    • pp.346-351
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    • 2009
  • 청주시 토양을 대상으로 다이옥신의 오염수준 및 특성에 대해 조사하였다. 채취된 28개 지점의 토양 중 17개 다이옥신 이성질체의 농도범위는 2.30${\sim}$630.40(평균 55.42) pg/g-dry으로 검출되었으며 TEQ 농도범위는 0.002${\sim}$9.79(평균 1.13) pg I-TEQ/g-dry로 조사되었다. 이들 농도는 우리나라 소각시설 주변의 농도(불검출${\sim}$153.23, 평균 7.36 pg I-TEQ/g-dry)보다 매우 낮은 수준을 나타내었다. 총농도와 TEQ 농도와는 99% 신뢰구간에서 서로 상관성을 나타냈다(p값<0.001). 토지이용별 농도는 공단>녹지>주거 및 상업지>농경지의 순으로 높게 나타났다. 이성질체 조성에 있어서는 일반적으로 토양 중에서 높게 검출되는 OCDD의 비율이 22${\sim}$100%(평균 59%)로 채취지점에 따라 편차가 심하였으며, PCDF/PCDD의 비율 또한 0.1${\sim}$2.4(평균 0.8)로 지점에 따라 편차를 보였다.