• 대한인간공학회지
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• 제34권6호
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• pp.563-581
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• 2015

Objective: This study was conducted to investigate the potential of sematic network analysis for design research. Background: As HCD (Human-Centered Design) was emphasized, lots of design research methodologies were developed and used in order to find user needs. However, it is still difficult to discover users' latent needs. This study suggests the semantic network analysis as a complementary means for design research, and proved its potential through the practical application, which compares multi-screen purchase and usage behaviors between America and China. Method: We conducted an in-depth interview with 32 consumers from USA and China, and analyzed interview texts through semantic network analysis. Cross cultural differences in purchase and usage behaviors were investigated, based on measuring centrality and community modularity of devices, functions, key buying factors and brands. Results: Americans use more services and functions in the multi-screen environment, compared to Chinese. As a device substitutes other devices, traditional boundaries of the devices are disappearing in the USA. Americans consider function to recall Apple, but Chinese consider function, design and brand to recall Apple, Sony and Samsung as an important brand at the time of their purchase. Conclusion: This study shows the potential of semantic network analysis for design research through the practical application. Semantic network analysis presents how the concepts regarding a theme are structured in the cognitive map of users with visual images and quantitative data. Therefore, it can complement the qualitative analysis of the existing design research. Application: As the design environment becomes more and more complicated like multi-screen environment, semantic network analysis, which is able to provide design insights in the intuitive and holistic perspective, will be acknowledged as an effective tool for further design research.

• 한국주조공학회지
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• 제43권1호
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• pp.43-49
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• 2023

• 대한전자공학회논문지
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• 제23권1호
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• pp.10-19
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• 1986

This is the last part of the four-part describing the development of a packet-switched computer communication network named the KORNET. In this paper we describe the design and implementation of the packet assembler/dissassembler (PAD) protocol for the asynchronous channel service, and of the network management softwares. The line processing module-B(LPMB) system supporting the asynchronous line includes a PAD protocol, a packet mode DTE/DCE protocol converting to the X.25 protocol, and the asynchronous receiver/transmitter(ART) software. The network management software is operated in master central processing module(MCPM) which includes virtual circuit management (VCM) managing the user channel, the routing management and the high level protocol for communication between the network management center (NMC) and the network node processor(NNP). In this paper, the design, implementation and operation of the softwares for the above service functions will be described in detail.

• 산업공학
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• 제25권4호
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• pp.458-471
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• 2012

In this study, we investigate the cooperative relationships between researchers who have co-authorship in the logistics-related journals in Korea by using social network analysis (SNA). We analyzed the co-authorship data of 781 articles published from 2005 to 2011 in four journals of 'Logistics Study', 'Journal of Korean Society of SCM', 'Korea Logistics Review' and 'Journal of Shipping and Logistics.' We examined the trend of cooperative research in the field of logistics with basic data of the co-authorship network. Then, we analyzed structural properties of the network and the sub-networks of research groups having co-authorship. We could verify the authors who play important roles within the network by using SNA indicators. In addition, we constructed the keyword networks based on the keyword data of all articles by research groups in order to understand the research topics of each group, and thereby we could draw several implications on the cooperative researches in the field of logistics.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.841-844
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• 2005

다양한 이동 기술, 센서, 원격 제어 및 인프라가 발달하고 생활의 질에 대한 기대치가 높아짐에 따라 홈 네트워크에 관한 다양한 기술과 서비스에 관한 연구과 개발이 진행되고 있다. 현재까지는 사용자에게 높은 수준의 홈 네트워크 서비스 개발에 중점을 둔 반면에, 이의 안전성을 보장하는 홈 네트워크 보안에 관해서는 많은 연구가 이루어지지 않고 있는 실정이다. 따라서 본 논문에서는 다양한 사용자가 각자의 특성과 취향에 맞는 홈 네트워크 서비스를 제공받을 수 있고, 외부의 불법 접근이나 침입으로부터 홈 네트워크 시스템을 안전하게 보호하기 위한 홈 네트워크 접근 모델을 제안하고자 한다.

• KEPCO Journal on Electric Power and Energy
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• 제6권4호
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• pp.419-425
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• 2020

DC distribution system has been evaluated as an excellent one in comparison with existing AC distribution network because it needs fewer power conversion stages and the full capacity of the equipment can be used without consideration for power factor. Recently, research and development on the implementation of DC distribution networks have been progressed globally based on the rapid advancement in power-electronics technology, and the technological developments from the viewpoint of infrastructure are also in progress. However, to configure a distribution network which is a distribution line for DC, more accurate and rapid introduction of analysis technology is needed for the monitoring, control and operation of the system, which ensure the system run flexible and efficiently. However, in case of a bipolar DC distribution network, there are two buses acting as slack buses, so the Jacobian matrix cannot be configured. Without solving this problem, DC distribution network cannot be operated when the network is unbalanced. Therefore, this paper presented a comprehensive method of analysis with consideration of operating elements which are directly connected between neutral electric potential caused by the unbalanced of load in DC distribution network with bipolar structure.

• The Korean Journal of Physiology and Pharmacology
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• 제15권6호
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• pp.339-344
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• 2011

Ulmus davidiana var. japonica Rehder (Urticales: Ulmaceae) (UD) is a tree widespread in northeast Asia. It is traditionally used for anticancer and anti-inflammatory therapy. The present study investigated the effect of an ethanol extract of UD on vascular tension and its underlying mechanism in rats. The dried root bark of UD was ground and extracted with 80% ethanol. The prepared UD extract was used in further analysis. The effect of UD on the cell viability, vasoreactivity and hemodynamics were investigated using propidium iodide staining in cultured cells, isometric tension recording and blood pressure analysis, respectively. Low dose of UD ($10{\sim}100{\mu}g/ml)$ did not affect endothelial cell viability, but high dose of UD reduced cell viability. UD induced vasorelaxation in the range of $0.1{\sim}10{\mu}g/ml$ with an $ED_{50}$ value of $2{\mu}g/ml$. UD-induced vasorelaxation was completely abolished by removal of the endothelium or by pre-treatment with L-NAME, an inhibitor of nitric oxide synthase. UD inhibited calcium influx induced by phenylephrine and high $K^+$ and also completely abolished the effect of L-NAME. Intravenous injection of UD extracts (10~100 mg/kg) decreased arterial and ventricular pressure in a dose-dependent manner. Moreover, UD extracts reduced the ventricular contractility (+dP/dt) in anesthetized rats. However, UD-induced hypotensive actions were minimized in L-NAME-treated rats. Taken together, out results showed that UD induced vasorelaxation and has antihypertensive properties, which may be due the activation of nitric oxide synthase in endothelium.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1575-1579
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• 2003

This paper present the control of an intelligent home robot based on home network. The existing research is almost research of independent robot. home network will be a way that equipments in home exchange information. As robot combine home network, robot will be more intelligent and more powerful. We benefit for that load is divided in home network environment. The robot which has ultrasonic sensors performs obstacle avoidance with the Fuzzy Algorithm. Ethernet serial converter transmit the measuring data of home to a home server and the home server accumulates data. The home server controls the robot and manages home according to the acquired data. This paper supposed the home network system that consist of home server, embedded robot and intelligent home robot.

• ETRI Journal
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• 제26권1호
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• pp.27-37
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• 2004

The architecture in a differentiated services (DiffServ) network is based on a simple model that applies a per-class service in the core node of the network. However, because the network behavior is simple, the network structure and provisioning is complicated. If a service provider wants dynamic provisioning or a better bandwidth guarantee, the differentiated services network must use a signaling protocol with QoS parameters or an admission control method. Unfortunately, these methods increase the complexity. To overcome the problems with complexity, we investigated scalable dynamic provisioning for admission control in DiffServ networks. We propose a new scalable $qDPM^2$ mechanism based on a centralized bandwidth broker and distributed measurement-based admission control and movable boundary bandwidth management to support heterogeneous QoS requirements in DiffServ networks.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1562-1564
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• 2005

The study for ubiquitous computing infra is proceeding actively, it make possible to use service and access network anywhere, anytime because of wire/wireless communication technology and progress of hardware. Domestically, study for the network mobility support technology which is the key technology for future ubiquitous computing realization have progressed, but that is insufficient. Especially, there is no study for independent mobility support study about railway wireless network. So, this study propose network mobility management technology for mobile network infra in railway and proper network model in train.