• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.1070-1088
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• 2017

Recently, the applications of Internet of Things (IoTs) are growing rapidly. Wireless Sensor Network (WSN) becomes an emerging technology to provide the low power wireless connectivity for IoTs. The IPv6 over low-power wireless personal area networks (6LoWPAN) has been proposed by IETF, which gives each WSN device an IPv6 address to connect with the Internet. The transmission congestion in IoTs could be a problem when a large numbers of sensors are deployed in the field. Therefore, it is important to consider whether the WSN devices have be completely integrated into the Internet with proper quality of service (QoS) requirements. The Software Defined Network (SDN) is a new architecture of network decoupling the data and control planes, and using the logical centralized control to manage the forwarding issues in large-scale networks. In this research, the SDN-based 6LoWPAN Border Router (6LBR) is proposed to integrate the transmission from WSNs to Internet. The proposed SDN-based 6LBR communicating between WSNs and the Internet will bring forward the requirements of end-to-end QoS with bandwidth guarantee. Based on our experimental results, we have observed that the selected 6LoWPAN traffic flows achieve lower packet loss rate in the Internet. Therefore, the 6LoWPAN traffic flows classified by SDN-based 6LBR can be reserved for the required bandwidth in the Internet to meet the QoS requirements.

• 한국군사과학기술학회지
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• 제19권5호
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• pp.645-653
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• 2016

The terrestrial wireless backbone network and satellite communications system have been independently developed depending on their own purposes and operational concepts, which results in different characteristics in terms of network architecture and routing protocol operation. In this paper, we propose a method for structurally integrating them in consideration of routing mechanism in an autonomous system. Our approach is that the routers of satellite network operate the OSPF in PTP mode on their interfaces connected to the routers of terrestrial wireless backbone network with grid connectivity, whereas the OSPF in satellite network whose topology is of hub-spoke type runs in NBMA mode. We perform some simulations to verify that the satellite communications system can be integrated and interwork with the terrestrial wireless backbone network by our proposed approach. From simulation results, it is also found that the increases of network convergence time and routing overhead are acceptable.

• ETRI Journal
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• 제42권5호
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• pp.643-657
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• 2020

Sixth generation will exploit satellite, aerial, and terrestrial platforms jointly to improve radio access capability and unlock the support of on-demand edge cloud services in three-dimensional (3D) space, by incorporating mobile edge computing (MEC) functionalities on aerial platforms and low-orbit satellites. This will extend the MEC support to devices and network elements in the sky and forge a space-borne MEC, enabling intelligent, personalized, and distributed on-demand services. End users will experience the impression of being surrounded by a distributed computer, fulfilling their requests with apparently zero latency. In this paper, we consider an architecture that provides communication, computation, and caching (C3) services on demand, anytime, and everywhere in 3D space, integrating conventional ground (terrestrial) base stations and flying (non-terrestrial) nodes. Given the complexity of the overall network, the C3 resources and management of aerial devices need to be jointly orchestrated via artificial intelligence-based algorithms, exploiting virtualized network functions dynamically deployed in a distributed manner across terrestrial and non-terrestrial nodes.

• 한국실내디자인학회논문집
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• 제16권6호
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• pp.250-257
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• 2007

Characteristics of color application indicated from Kirchsteigfeld is presented the various points of view to be preserved urban housing color. It had been handled as environmental color by view point of community and connectivity rather than color scheme of single housing. First, color to be consisted of basis for urban entirely as background color in urban housing complex has been indicated the bright and cheerful feelings and expressed to be introduced mostly from the single color system. Second, characteristics to be inhibited strongly from housing complex had been indicated by restricted four types of color, formulated the overall context and change through accent and the change from disposition of principal and the accessary of color scheme. In this case, it was not regular formulation, but as a whole category view, it could be provided by orderly regularity system strictly Particularly it had been applied as a whole for lightness change by single color, introduced the different color of building to be centered or remained by a visual point. This had been formed to introduction of color by stand points of housing group not introduction to color by sole concept of building. Third, emphasizing of morphologic feeling by using of difference of lightness, it could be indicated the mild and comfortable stereo-type sensibility from the overall types of housing, we could understand for formation of color code by lightness of slightly differences. Fourth, it had been taken the convenient adaptation method for maintenance of simple graphic system as a environmental color. It has considerable advantage for sustainability of color to indicate on finishing material, form and detail in architecture, as the sole separated color not to be complicated when to be painted over and again or managed continuously.

• 한국환경복원기술학회지
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• 제12권3호
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• pp.142-163
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• 2009

Taebaek city is located in the mountainous plateau area therefore the major industry was coal industry. According to dramatically declining of the major industry, Taebaek city is need to alternative industry which associated with considering the geographical characteristics of natural tourism resources for increasing the local economy. On the basis of these reasons, this study can be suggested ecological planning and mitigation of deterioration technique about the these study site. That is the reserved area for mountainous experience theme park. As the results of environmental ecology assessment are following as; The natural ecosystem areas, multi-layer structure forest such as forest of Pinus densiflora, forest of Quercus mongolica and deciduous forest have a high value of nature, diversity and potential. In addition, wild bird habitats were important area as a inhabitation, breeding, feeding and hiding. Therefore, on these areas should be preserved. Also, it needs to conserve on there such as more than three types of wild bird inhabitate areas, the fringe of high biological diversity, the wetland that have got good vegetation condition and the function of amphibia, reptiles crossing. In addition, inhabitation, the waterway of wetland form that have got wide waterside width needs to conserve. In conclusion, on the basis of analysis results such as conditions of plan, environment, ecological assessments, survey informations are able to suggest the connectivity of the axis of forest and management plan. Moreover, in the part of forest restoration plan, we suggest the plan of transplant for a compensation of damaged forest by land use.

• 한국정보통신학회논문지
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• 제19권11호
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• pp.2671-2676
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• 2015

오늘날, 모바일 장치는 현재 응용 프로그램의 넓은 범위를 지원 할 수 있습니다. 불행히도, 일부 응용 프로그램은 늘어나는 계산 능력을 필요로 하고 모바일 장치는 이러한 낮은 처리 능력, 제한된 메모리, 예측할 수없는 연결 및 제한된 배터리 수명으로 제약에 자원이 한정되어 있습니다. 모바일 장치의 한계를 극복하기 위해 연구자들은 강력한 컴퓨팅 인프라 모바일 장치에서의 작업 부하를 이동하기 위해 가상화 기술을 사용하여 모바일 장치에 클라우드 컴퓨팅 서비스를 확장하는 상상합니다. 이러한 기술은 인프라 자원이 풍부한 클라우드 또는 서버에 모바일 장치에서 자원을 많이 소비하는 계산의 이행으로 구성되어 있습니다. 본 논문에서 클라우드 아키텍처 기능에 클라우드과 모바일 장치 사이의 거리의 영향을 분석합니다.

• 한국컴퓨터산업학회논문지
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• 제2권7호
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• pp.983-996
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• 2001

MANET은 기존의 이동 통신망과는 달리 백본망이 없고, 동적으로 분산된 이동 호스트들로 구성되어 전시나 천재지변과 같은 긴급사태 및 기존의 이동 통신 기반 구조가 존재하지 않는 지역에서 사용되는 통신 구조이다. 따라서 MANET에 기존의 라우팅 알고리즘을 적용할 수 없으며, 새로운 라우팅 알고리즘의 연구가 활발히 이루어지고 있다. 본 논문은 기존에 제안된 라우팅 알고리즘 중 클러스터에 헤더(주헤더)를 두어 관리하는 클러스터 기반의 한 라우팅 프로토콜(CBRP)에 주헤더 뿐만 아니라 보조헤더를 추가한다. 보조헤더의 역할은 주헤더가 비정상적으로 되어 노드들 간의 송수신에 더 이상 참가할 수 없을 경우, 별도의 주헤더 재선출 과정 없이 보조헤더가 즉시 주헤더로 교체되어 기존의 주헤더 역할을 담당한다. 따라서 본 논문은 기존의 CBRP에 비해 효율적인 라우팅 알고리즘 CBRP-SH를 제안한다. 또한 본 논문의 우수성을 입증하기 위해 기존의 CBRP와 비교 평가한다.

• Journal of Information Processing Systems
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• 제5권3호
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• pp.117-130
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• 2009

By providing ubiquitous Internet connectivity, wireless networks offer more convenient ways for users to surf the Internet. However, wireless networks encounter more technological challenges than wired networks, such as bandwidth, security problems, and handoff latency. Thus, this paper proposes new technologies to solve these problems. First, a Security Access Gateway (SAG) is proposed to solve the security issue. Originally, mobile terminals were unable to process high security calculations because of their low calculating power. SAG not only offers high calculating power to encrypt the encryption demand of SAG's domain, but also helps mobile terminals to establish a multiple safety tunnel to maintain a secure domain. Second, Robust Header Compression (RoHC) technology is adopted to increase the utilization of bandwidth. Instead of Access Point (AP), Access Gateway (AG) is used to deal with the packet header compression and de-compression from the wireless end. AG's high calculating power is able to reduce the load on AP. In the original architecture, AP has to deal with a large number of demands by header compression/de-compression from mobile terminals. Eventually, wireless networks must offer users "Mobility" and "Roaming". For wireless networks to achieve "Mobility" and "Roaming," we can use Mobile IPv6 (MIPv6) technology. Nevertheless, such technology might cause latency. Furthermore, how the security tunnel and header compression established before the handoff can be used by mobile terminals handoff will be another great challenge. Thus, this paper proposes to solve the problem by using Early Binding Updates (EBU) and Security Access Gateway (SAG) to offer a complete mechanism with low latency, low handoff mechanism calculation, and high security.

• 대한건축학회논문집:계획계
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• 제35권9호
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• pp.65-75
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• 2019

This study aims at analyzing the therapeutic design characteristics implemented in the indoor atriums of the outpatient areas in four children's hospitals in London and San Francisco. A mixed-method approach was used to examine the spatial configurations and design elements in the atriums, while a literature review was conducted to understand the therapeutic design characteristics relevant to atrium spaces and children's healthcare facilities. The spatial design and the pattern of use of the atrium in each hospital were studied during field visits and interviews with the hospital management staff. Based on the literature review and the observations from the field study, a Visibility Graphic Analysis was chosen to examine the visibility, accessibility, and intelligibility of the spatial configurations in the atriums of each hospital. In addition, the openness, restfulness, and vibrant ambience of the design elements in the atriums of each hospital were investigated by surveying fifty-two design professionals on the quality of the design elements in the atriums. A spatial configuration analysis, confirmed that all the atrium spaces had high visibility, accessibility, and intelligibility due to their high connectivity, integration, intelligibility, and because the atriums were laid out in the open lobby space, along the major circulation axis, or in the circulation intersection. In the survey of the design element evaluation, all atriums proved to be appropriate in terms of openness, while the adequacy of restfulness and vibrant ambience differed depending on the hospitals. Notably, location and orientation, access, natural light, outdoor view, and play facilities were found significant environmental design elements determining the successful implementation of the therapeutic design in the atriums. The observations from the aforementioned are further discussed to enhance the therapeutic design quality of atrium spaces in children's hospitals.

• 인간식물환경학회지
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• 제22권6호
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• pp.665-676
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• 2019

The Korean society is currently showing a decrease in the child population and a rapid increase in the elderly population due to low birth rates and aging, but the current park system does not reflect the changing population structure. This study aimed to find ways to plan and promote use of senior-friendly parks for the aging society. The results are as follows. First, the elderly mostly gathered in Tapgol Park and Jongmyo Park which were accessible to subways and close to amenities and traditional markets. The elders usually gathered around buffer zones or green spaces set up to protect cultural heritages. Second, many elderly users were observed in Osolgil Silver Park and Sinteuri Park which were renovated with senior-friendly concept. These parks were recognized as places that the elderly people could visit without minding users of other generations because the elderly users were ensured by words such as 'seniors only' or 'senior-friendly'. Third, the importance of the locational conditions for the senior-friendly parks should be mentioned. A senior-friendly park must be located in an urban center to have convenient access to transportation, secure large green spaces, and make elderly users feel at ease with social connectivity when they use the amenities there. Fourth, the survey results showed that elderly people visited parks to exerciseand take a walk (track),by age, older age groups visited the park to socialize with other elders around their age. Fifth, the most desired facilities for constructing senior-friendly parks were fitness equipment, and sports facilities like a trail, track, and gateball field, and in some cases, vegetable gardens and indoor rest area to avoid wind in cold weather.