• 미생물학회지
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• 제19권4호
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• pp.192-198
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• 1981

Protoplasts from Trichoderma koningii were fractioned at varing digestion periods. There were distinct differences between the fractionated protoplasts in CMCase activity and protein content ; namely, protein contents and CMCase activities in the early-protoplasts were higher than the late-produced protoplasts. Reversion frequencies of the early-produced protoplasts. Reversion frequencies of the early-produced protoplasts (0-1hr.) and the late-produced protoplasts (1-2.5 hr.)were 1.25% and 0.56%, respectively. From these results it was assumed that the early-produced protoplasts were more active in physiological metabolism. Meanwhile, in osmotically stabilized liquid medium two distinct reversion patterns of these protoplasts were found. In the first, normal germ tube was developed from the opposite side of the protoplast after the production of an aberrent tube. In the second, reversion occurred through germination of protoplast, but this patterns was uncommon. It is suggested that the the physiological and morphological heterogeneities in protoplast reversion are related to the heterogeneous origins of protoplasts from highly differentiated mycelium.

• 신재생에너지
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• 제2권4호
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• pp.56-63
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• 2006

In this paper, heat and mass transfer characteristics through experimental and numerical study are extensively investigated in steam reforming reactor under given operating conditions. In order to get simulated data at outlet of the reformer, heterogeneous reactor model is incorporated. As the reaction also takes place in porous media, two medium approach is used to take into account thermally non-equilibrium phenomena between catalyst and bulk gas. From various parametric studies, significance of heat transfer is emphasized in steam reforming reaction.

• 한국정보처리학회논문지
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• 제7권5S호
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• pp.1629-1637
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• 2000

With wide spending the Internet and Web techniques, we have recognized the necessary and commercial-value of electronic commerce system. Electronic commerce(EC) means the whole economical activities based on electronic medium. Both scalability and flexibility are fundamental attributes of EC system and interoperability among heterogeneous systems must be supported. So, for successful a developing of EC system, it is necessary to apply the CBD (Component Based Development) based on component assembling and customization. In this paper, we propose the method for identifying and specifying the components to construct the component based electronic commerce system. To do, we define the component/system architecture specified on EC domain, identified and classified the EC components with hierarchy relationship. Also, we suggested the specification notation and some examples.

• ETRI Journal
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• 제28권3호
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• pp.311-319
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• 2006

This paper presents a terminal-assisted frame-based packet reservation multiple access (TAF-PRMA) protocol, which optimizes random access control between heterogeneous traffic aiming at more efficient voice/data integrated services in dynamic reservation TDMA-based broadband access networks. In order to achieve a differentiated quality-of-service (QoS) guarantee for individual service plus maximal system resource utilization, TAF-PRMA independently controls the random access parameters such as the lengths of the access regions dedicated to respective service traffic and the corresponding permission probabilities, on a frame-by-frame basis. In addition, we have adopted a terminal-assisted random access mechanism where the voice terminal readjusts a global permission probability from the central controller in order to handle the 'fair access' issue resulting from distributed queuing problems inherent in the access network. Our extensive simulation results indicate that TAF-PRMA achieves significant improvements in terms of voice capacity, delay, and fairness over most of the existing medium access control (MAC) schemes for integrated services.

• 미생물학회지
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• 제21권4호
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• pp.238-244
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• 1983

In order to obtain Ti plasmid which may be used in genetic engineering of higher plants, virulent Agrobacterium tumefaciens were isolated from soil with selective medium. For their identification, morphological and cultural characteristics were investigated in parallel with physiological and turnorigenesis test. 14 strains were isolated from various regions in Korea. 3 of them were identified as biotype 1 and the others were so heterogeneous that they are not yet conformed to any biotypes. However, Ti plasmid was isolated from A. tumefaciens KU 14 strain, one of the above mentioned 14 strains.

• 지식경영연구
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• 제19권4호
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• pp.149-170
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• 2018

Healthcare lifelog, a personal record relating to disease treatment and healthcare, plays an important role in healthcare paradigm shifts in which medical and information technology converge. Healthcare services based on various healthcare lifelogs are being launched domestically by both large corporations and small and medium enterprises, however, they are being built on an individual platform that is dependent on each company. Therefore, the terms of lifelog data are different as well as the measurement specifications are not uniform. This study proposes a reference model for minimum common data required for sharing and utilization of healthcare lifelog. Literature study and expert survey derived 3 domain, 17 essential items, and 51 sub-items. The model provides definition, measurement data format, measurement method, and precautions for each detailed measurement item, and provides necessary guidelines for data and service design and construction for healthcare service. This study has its significance as a basic research supporting the activation of ecosystem by ensuring interoperability of data between heterogeneous healthcare devices linked to digital healthcare platform.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.439-444
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• 2011

As construction projects have been getting larger and more complex, a single individual or organization cannot have complete knowledge or the abilities to handle all matters. Collaborative practices among heterogeneous individuals, which are temporarily congregated to carry out a project, are required in order to accomplish project objectives. These organizational knowledge creation processes of project teams should be understood from the active and dynamic viewpoint of how they create information and knowledge rather than from the passive and static input-process-output sequence. To this end, agent-based modeling and simulation which is built from the ground-up perspective can provide the most appropriate way to systematically investigate them. In this paper, agent-based modeling and simulation as a research method and a medium for representing theory is introduced. To illustrate, an agent-based simulation of the evolution of collaboration in large-scale project teams from a game theory and social network perspective is presented.

• 한국항행학회논문지
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• 제11권1호
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• pp.24-30
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• 2007

최근 WLAN과 차세대 이동통신의 결합 서비스와 관련하여 이종 네트워크의 연동에 대한 요구가 증대되고 있다. 또한 무선 네트워크에서 원활한 밀티미디어 서비스와 QoS 보장의 중요성이 대두되고 있다. 따라서 무선 이종 네트워크에서 원활한 멀티미디어 서비스와 QoS 보장에 관련된 연구가 활발히 진행되고 있다. 본 논문에서는 WLAN과 WiBro 이종 네트워크에서 멀티미디어 서비스 및 QoS의 연속성을 제공하기 위해서 새로운 연동 방안을 제안한다. 그리고 제안한 연동 방안을 바탕으로 inter-network vertical handover 알고리즘과 QoS-aware MAC 알고리즘을 제공한다. 또한 NS-2 시뮬레이션을 사용하여 성능을 비교, 분석 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.5835-5854
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• 2017

The implementation of IEEE 802.15.6 in Wireless Body Area Network (WBAN) is contention based. Meanwhile, IEEE 802.15.4 MAC provides limited 16 channels in the Superframe structure, making it unfit for N heterogeneous nature of patient's data. Also, the Beacon-enabled Carrier-Sense Multiple Access/Collision-Avoidance (CSMA/CA) scheduling access scheme in WBAN, allocates Contention-free Period (CAP) channels to emergency and non-emergency Biomedical Sensors (BMSs) using contention mechanism, increasing repetition in rounds. This reduces performance of the MAC protocol causing higher data collisions and delay, low data reliability, BMSs packet retransmissions and increased energy consumption. Moreover, it has no traffic differentiation method. This paper proposes a Low-delay Traffic-Aware Medium Access Control (LTA-MAC) protocol to provide sufficient channels with a higher bandwidth, and allocates them individually to non-emergency and emergency data. Also, a Contention Differentiated Adaptive Slot Allocation CSMA-CA (CDASA-CSMA/CA) for scheduling access scheme is proposed to reduce repetition in rounds, and assists in channels allocation to BMSs. Furthermore, an On-demand (OD) slot in the LTA-MAC to resolve the patient's data drops in the CSMA/CA scheme due to exceeding of threshold values in contentions is introduced. Simulation results demonstrate advantages of the proposed schemes over the IEEE 802.15.4 MAC and CSMA/CA scheme in terms of success rate, packet delivery delay, and energy consumption.

• 한국인터넷방송통신학회논문지
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• 제12권1호
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• pp.275-281
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• 2012

커뮤니티 네트워크는 이기종(heterogeneous) 노드들이 시간과 장소에 구애받지 않고 정보를 공유할 수 있는 통신 환경을 말한다. 이를 위해 이동 노드들은 사전에 구성된 통신 인프라 시설에 의존하지 않고 자가 구성될 수 있어야 하고 노드의 이동성으로 인해 변경되는 네트워크 토폴로지에 적응할 수 있어야 한다. 준-인프라 기반 무선 애드-혹 네트워크는 이러한 요구사항을 지원하기에 적합한 통신 기술이다. 본 논문에서는 준-인프라기반 애드-혹 네트워크 프로토콜의 실험에 용이한 평가 도구인 VTC(virtual topology coordinator) 시스템을 제안한다. VTC는 모든 통신장비간 단일 홉 통신만이 가능한 작은 공간에서도 선택적 MAC(Medium Access Control) 프레임 수신 메커니즘을 이용하여 다중 홉 네트워크 토폴로지를 가상으로 구성하도록 해준다. VTC 시스템은 실제의 무선 특성을 모두 반영하기는 어려우나 시뮬레이션을 통한 검증보다는 실 특성을 보다 다양하게 반영시킬 수 있다.