• Korean Journal of Microbiology
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• v.19 no.4
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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.

• New & Renewable Energy
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• v.2 no.4 s.8
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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.

• The Transactions of the Korea Information Processing Society
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• v.7 no.5S
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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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• v.28 no.3
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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.

• Korean Journal of Microbiology
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• v.21 no.4
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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.

• Knowledge Management Research
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• v.19 no.4
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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.

• International conference on construction engineering and project management
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• 2011.02a
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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.

• Journal of Advanced Navigation Technology
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• v.11 no.1
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• pp.24-30
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• 2007

The integration of WLAN and beyond 3G mobile networks offers the possibility of achieving anytime and anywhere Internet access. Moreover the requests for seamless multimedia services and the Quality of Service (QoS) support have been one of key issues in wireless networks. Therefore the researches relative to seamless multimedia service and QoS over heterogeneous wireless networks have been progressing rapidly. In this paper, we propose inter-working architecture for supporting seamless multimedia service and QoS over WLAN and WiBro networks. Based on the proposed inter-working architecture, we also provide both the seamless handover architecture such an inter-network vertical handover and the QoS-aware wireless Medium Access Control (MAC) scheme. In addition, we evaluate and compare the performance by Network Simulator-2 (NS-2) simulations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.275-281
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• 2012

Community network is a communication environment where heterogeneous devices can access and communicate with each other at any time and at any space to share information. To do so, mobile devices are required to be self-configured even in absence of communication infrastructures. Semi-infrastructured wireless ad-hoc network is a promising solution to meet with such a requirement. This paper proposes the VTC(virtual topology coordinator) system as an evaluation tool for examining network protocols that are intended to be deployed in the semi-infrastructured ad-hoc networks. VTC emulates multi-hops wireless network topology virtually using a mechanism of selective receiving MAC frame in a small area, where only a single hop communication is available. VTC system cannot consider all properties introduced in real wireless network, but do more wireless properties than verification through simulation.