• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4372-4388
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• 2014

Robotic sensor network (RSN) contains mobile sensors and robots providing feasible solution for many multi-agent applications. One of the most critical issues in RSN and its application is how to effectively assign tasks. This paper presents a novel connectivity preserving hybrid task allocation strategy to answer the question particularly for RSN. Firstly, we model the task allocation in RSN to distinguish the discovering and allocating processes. Secondly, a fully distributed simple Task-oriented Unoccupied Neighbor Algorithm, named TUNA, is developed to allocate tasks with only partial view of the network topology. A connectivity controller is finally developed and integrated into the strategy to guarantee the global connectivity of entire RSN, which is critical to most RSN applications. The correctness, efficiency and scalability of TUNA are proved with both theoretical analysis and experimental simulations. The evaluation results show that TUNA can effectively assign tasks to mobile robots with the requirements of only a few messages and small movements of mobile agents.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2246-2255
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• 2023

Evacuation time estimation (ETE) is crucial for the effective implementation of resident protection measures as well as planning, owing to its applicability to nuclear emergencies. However, as confirmed in the Fukushima case, the ETE performed by nuclear operators does not reflect behavioral features, exposing thus, gaps that are likely to appear in real-world situations. Existing research methods including surveys and interviews have limitations in extracting highly feasible behavioral features. To overcome these limitations, we propose a VR-based immersive experiment system. The VR system realistically simulates nuclear emergencies by structuring existing disasters and human decision processes in response to the disasters. Evacuation behavioral features were quantitatively extracted through the proposed experiment system, and this system was systematically verified by statistical analysis and a comparative study of experimental results based on previous research. In addition, as part of future work, an application method that can simulate multi-level evacuation dynamics was proposed. The proposed experiment system is significant in presenting an innovative methodology for quantitatively extracting human behavioral features that have not been comprehensively studied in evacuation. It is expected that more realistic evacuation behavioral features can be collected through additional experiments and studies of various evacuation factors in the future.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.435-444
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• 2016

In Korea, approximately 48% of all households live in apartments, which are a form of multi-unit dwellings, and this figure increases up to 58%, when row houses and multiplex houses are included. As such, majority of the population reside in multi-unit dwellings where they are exposed to the problem of floor impact noise that can cause disputes and conflicts. Accordingly, this study was conducted to manufacture a high-weight, high-stiffness foamed concrete in order to develop a technology to reduce the floor impact noise. For the purpose of deriving the optimum mixing ratio for the foamed concrete that best reduces the floor impact noise, the amounts of the foaming agent, lightweight aggregate and binder were varied accordingly. Also, the target characteristics of the concrete to be developed included density of over $0.7t/m^3$, compressive strength of over $2.0N/mm^2$ and thermal conductivity of under 0.19 W/mK. The results of the experiment showed that the fluidity was very excellent at over 190 mm, regardless of the type and input amount of foaming agent and lightweight aggregate. The density and compressive strength measurements showed that the target density and compressive strength were satisfied in the specimen with 50% foam mixing ratio for foamed concrete and in all of the mixtures for the lightweight aggregate foamed concrete. In addition, the thermal conductivity measurements showed that the target thermal conductivity was satisfied in all of the foamed concrete specimens, except for VS50, in the 25% replacement ratio case for Type A aggregate, and all of the mixtures for Type B aggregate.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.238-243
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• 2004

High temperature air blown gasification is new concept to utilize the waste heat from gasifier that is called the multi-staged enthalpy extraction technology. This process was developed to solve the economic problem due to air separation cost for the oxygen-blown as a gasifiying agent. In this study, we have performed the construction of pebble bed gasifier and operated it by controlling the pebble size and bed height. As a result, we can produce the syngas with the calorific value of 700kcal/$Nm^3$ at the condition of air temperature 650$^{\circ}C$.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.254-257
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• 2009

유비쿼터스 시대가 도래하면서 사용자를 중심으로 하는 서비스에 대한 관심이 증가하고 있다. 더불어 사용자의 특성에 맞는 개인화 된 서비스를 요구하고 있다. 본 논문에서는 유비쿼터스 공간에서 소형화, 지능화되고 있는 개인형 이종 디바이스 간의 협업을 통해 사용자에게 보다 직관적이고 편리한 개인화된 서비스를 제공하기 위한 디바이스 협업 기반 에이전트 기술을 제안한다. 본 연구에서는 센서를 통해 사용자 환경에 대한 정보 및 사용자 정보를 수집하여 기본적인 서비스에 필요한 상황정보를 처리한다. 또한, 유비쿼터스 사용자에게 필요한 멀티모달 서비스를 제공한다. 따라서 일반적인 자동화 서비스 이상의 개인 특성에 맞는 고품질의 서비스를 제공할 수 있다.

• Electronics and Telecommunications Trends
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• v.19 no.3 s.87
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• pp.107-116
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• 2004

지금까지의 정보통신 서비스는 사용자에게 필요한 정보를 제공하거나 사용자와 사용자를 연결해주는 통로로서의 서비스를 제공하여 왔으나, 유비쿼터스 컴퓨팅과 유비쿼터스 네트워크 기술을 기반으로 한 유비쿼터스 서비스는 사용자가 처한 상황에 기반하여 정보 제공은 물론 필요한 행위까지도 제공하여 사용자의 욕구에 가장 근접한 서비스 제공에 초점을 두는 컨시어지형 서비스가 될 것이다. 이러한 서비스는 사용자의 기호 및 상태, 또는 상황 등의 다양한 정보에 근거하여 서비스를 제공할 수 있어야 하며, 이를 위한 효과적인 접근 방법으로는 사용자의 다양한 정보를 각각의 대리자에게 처리를 하게 하는 멀티 에이전트 기술일 것이다. 본 연구에서는 음악이나 그림을 활용하여 신체적, 정신적 질환을 치료하는 음악 치료나 그림 치료인 Art-Therapy를 유비쿼터스 서비스의 구현 사례로 기술한다. 사용자의 신체적 또는 정신적 상태 및 환경 정보를 센서를 활용하여 측정하고 그 측정된 데이터에 근거하여 사용자의 상태를 판단하고 이에 따라 음악 및 미술 작품을 시청각으로 제공함으로써 치료 효과를 얻는다. 본 연구에서의 Art-Therapy 서비스는 FIPA에서 제안한 멀티 에이전트 기반 구조인 에이전트 플랫폼을 기반으로 구현하였다.

• Carbon letters
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• v.13 no.1
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• pp.29-33
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• 2012

A novel strategy for the simultaneous reduction and functionalization of graphene oxide (G-O) was developed using polyallylamine hydrochloride (PAAH) as a multi-functional agent. The G-O functionalization by PAAH was carried out under basic conditions to catalyze the epoxide ring opening reaction of G-O with abundant amine groups of PAAH. We found that G-O was not only functionalized with PAAH but also reduced under the reaction condition. Moreover, the synthesized PAAH-functionalized G-O sheets were soluble in water and applicable to the synthesis of nanocomposites with gold nanoparticles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.500-501
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• 2007

Automation systems for higher performance and efficiency in railway electrification systems are driving ever more demanding needs for new condition monitering systems which can consist of sensors connected to the substation and catenary systems. This paper reviews the recently developed condition monitering system, based on a IP network-based multi-agent system, wireless communications and sensor networks for railway electrification system. A new concept for information management, condition monitoring and control of power transmission are considered as railway automation in electrification system.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.129-131
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• 2004

The advanced technology called Telematics appeared with the development of automobile industries and IT technologies. In Telematics it is important to offer good quality information to the car which loads the terminal, so in this paper, for this, we propose the intelligent information service method using artificial intelligence(A. I.). In this paper, through the concept of multi-agent, we represent Telematics system and show the interaction between information service center and a terminal for smooth information service. Finally, we mention the way that Telematics should persue for the enhancement of information service.

• Bulletin of the Korean Chemical Society
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• v.14 no.6
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• pp.732-739
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• 1993

Good yields were usually obtained in Pd(O)-catalyzed Suzuki aryl-aryl coupling reaction, even when both coupling partners had an ortho tertiary benzamide functional group. The direct ortho functionalization of oligomeric tertiary benzamides at Snieckus condition is dependent on the chain length. Tertiary benzamide 1 can be o,o-dilithiated only by metal-halogen exchange of the 2,6-dihalo-compound. Bis-tertiary benzamide 9 can be o,o'-dilithiated with excess(4.1 equivalents) s-butyllithium/TMEDA as the lithiating agent. Tris-tertiary benzamide 21 is hard to o,o"-difunctionalize due to steric interactions among the tertiary benzamide functional groups, and due to steric interactions between these functional groups and others (if present) on the termini of the terphenyl unit.