• The KIPS Transactions:PartA
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• v.17A no.5
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• pp.237-248
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• 2010

UPnP(Universal Plug and Play) is a middleware of DLNA (Digital Living Network Alliance) services a home network. UPnP supports the connections between each other devices in networks and also provides service discovery and advertisement with SSDP(Simple Service Discovery Protocol), which is generally designed for wired networks. SSDP operates on multicasting discovery request and advertisement and unicasting a reply in networks. It is a challenge issue for service discovery protocol such as SSDP to provide a stable and effective service in wireless ad-hoc networks. Wired based service discovery protocol does not consider the dynamics of wireless ad-hoc network. In that case, the nodes are freely in or out. Therefore, this paper proposes a flexible SSDP(fSSDP) which is a peer-to-peer(P2P) discovery protocol adopted for wireless ad-hoc Networks. It is implemented on the extension of SSDP. fSSDP supports a functionality that the broadcast area of service discovery dynamically changes with the periodically updated area of advertisement. It is good for reducing messaging overhead caused from the broadcast flooding of service discovery in wireless ad-hoc network.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.631-632
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• 2008

In this paper, we propose service discovery mechanism, using CALM agent platform to guarantee scalability of scope of available services without modifying existing service discovery protocols. The proposed service discovery mechanism provides users with a wider selection of services, and convenient search methods.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.439-441
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• 2003

사용자의 인터넷 환경이 점차 무선 접속을 통한 인터넷의 사용과 실시간 응용 데이터의 사용이 늘어가는 추세에 따라. 이동 인터넷 서비스를 하기 위한 방안으로 Mobile If와 Mobile IPv6가 제시되었다. 본 논문에서는 Mobile IPv6 환경에서 Neighbor Discovery 중 Router Solicitation과 Router Advertisement가 호스트의 이동성 지원에 미치는 영향을 분석하였다. Neighbor Discovery 메시지들의 주기를 변경하여, 실제 구현, 측정하여 Handoff의 효율성과 전송 대역폭 overhead의 상관관계를 알아보았다.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.51-63
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• 2013

Recently with base apply MANET with the application for the service discovery and delivery which are various techniques are being proposed the result of such MANET base research techniques from actual inside. This dissertation proposes T-Chord(Trustworthy-based Chord) Ring system for MANET to guarantees from such requirements. T-Chord Ring system in order to manage Efficiently the services which the mobile nodes provide is the service discovery system which uses P2P overlay network Technique in mobile environment. The system which is proposed MANET communications in order to accomplish a service discovery operation with physical network class and logical network class will be able to minimize problems from about MANET service discoveries, and uses the dispersive hash table technique for a service discovery and effectiveness of service discovery improves and will be able to guarantee the expandability of network size. The mobile nodes(mobile device) have a mobility from MANET and operate with service request node, service provide node and service transmit node. The mobile nodes will be able to elect cluster header using Trustworthy that was evaluated service request, provision and delivery in each other. The system which is proposed a service discovery and a delivery efficiently will compose the cluster head which will grow of P2P overlay networks and will be able to accomplish. The system which proposes from dissertation is composed of Trustworthy evaluations of MANET mobile nodes, service information collection which is dispersed and P2P overlay networks that composed of Chord algorithm modules which provide O(Log N) efficiencies. The system comparison evaluation analyzes an efficiency from the expandability side of effectiveness and the network of service discovery technique and the service discovery message over head, service discovery and delivery of former times and service discovery and delivery is excellent gives proof from MANET.

• Natural Product Sciences
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• v.15 no.4
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• pp.203-207
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• 2009

A homoisoflavanone, 7,4'-dihydroxyhomoisoflavanone (1) and a flavanone, (2S)-7,4'-dihydroxy-5-methoxyflavanone (2), were isolated from the rhizomes of Anemarrhena asphodeloides, together with 4,4'-dihydroxychalcon (3), 2'-O-methylphlorethin (4), 1,3-bis-di-p-hydroxyphenyl-4-penten-1-one (5), and 2,4'-dihydroxy-4-methoxybenzophenone (6) on the basis of spectroscopic and physicochemical analyses including 1Dand 2D- NMR techniques as well as by comparison of their data with the published values. Compounds 1 - 4 were isolated for the first time from this plant source. Among isolates, compound 2 exhibited moderate inhibitory effect on the differentiation of pre-adipocyte 3T3-L1 cells.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.295-301
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• 2008

Phenylformamidines are well known as insecticides for their specific activity against the insects. It has now been established that they show insecticidal activity as agonists on the octopamine receptor which is located in the synapse membrane. In this study we tried to test the effect of fluorine substituted aromatic formamidines and 1,3,5-triazapenta-1,4-dienes. Among the compounds, 2h, 2k, 21, 3g, 3h, 3k showed good activity against mite and aphid and 4f and 4g showed high activity against mite.

• Journal of KIISE:Information Networking
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• v.32 no.2
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• pp.123-133
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• 2005

In recent years, service discovery is one of the major technologies of home networks which head for a pervasive computing environment. However, existing service discovery techniques are difficult to understand semantics, and they only provide syntactic level service matching. To solve these problems, we have designed and developed ontology for semantic service discovery. Our ontology could enrich the amount of devices and services representations with semantics, and the relation of devices and service could be efficiently described through primitive service. For representing context information of devices, we describe attributes of device including location information, device status and etc. To determine whether the developed ontology can be applied to service discovery systems, we have implemented a semantic service discovery system by extension of the existing Jini lookup service. Also, we have evaluated our ontology with associated software environment according to some experiment scenarios, and have proved the usefulness of our ontology-based semantic service discovery system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.10
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• pp.908-917
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• 2013

In this paper, we propose a discovery protocol for finding nearby mobile applications and services in a device-to-device communications system. The device-to-device communication technology enables proximity-based services such as mobile social networks and mobile marketing. For realizing these proximity-based services, it is essential to design a discovery protocol which pinpoints the devices with mobile applications of interest among hundreds and thousands of devices in proximity. In the infrastructure-less networks such as ad hoc networks, we can design the discovery protocol that periodically broadcasts a short discovery code containing the compressed information of the mobile applications. In this paper, we design the discovery protocol with the discovery code generated by using a hash function and a Bloom filter. We also mathematically analyze the performance of the proposed protocol.

• 한국ITS학회:학술대회논문집
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• 2004.11a
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• pp.106-110
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• 2004

• Journal of The Korean Association For Science Education
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• v.25 no.7
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• pp.711-720
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• 2005

The purpose of this study was to understand mechanisms of scientific discovery and how this can help students, as young scientists, to understand scientific ideas in the science classroom. To unravel this mechanism, this study employed the notion of chaos. This phenomena was rediscovered by Edward Lorenz. In this paper, the general concept of chaos was briefly discussed in relation with previous scientific theories such as Newtonian physics and quantum mechanics. Following this, discovery constraints in terms of available technology at the time was described. In addition, Lorenz's psychological processes during the discovery was also discussed. Based on analysis, major implications for the field of science education were the provision of relevant schemata, the use of cognitive tools, the presentation of problems with various representational forms, and the sharing of ideas with others.