• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.181-184
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• 2002

This paper describes remote control RS232 communication using internet service, safety of exchange data and internet traffic by Denial of Service Attacks. In case of Denial of service Attacks, it makes connection of internet service failed. So in this Paper, this solution was examined and implemented for receiving data in safety against Denial of Service Attacks by LabVIEW program of National Instruments.

• Journal of Korea Multimedia Society
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• v.4 no.4
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• pp.339-348
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• 2001

In this paper, a cell scheduling algorithm which can be applied to all of the service class in ATM network is proposed. The proposed algorithm classifies the order of priority in each service class into 4 categories and generates the weight of each class service based on the traffic parameters which are negotiated in connection contract. The proposed algorithm guarantees QoS(Quality of Service) to the traffic which is sensitive to delay carrying out CBR and rt_VBR service. As it effectively manages the connection which has small bandwidth, it minimizes the cell delay in the queue. For verifying the effectiveness of the proposed algorithm the proposed algorithm is simulated with existing cell scheduling algorithm and the result is showed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.2 s.332
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• pp.1-8
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• 2005

We have implemented a Jini-Agent system which enables resource-limited mobile devices to utilize the Jini connection service. The Jini-Agent system supports Jini connection technologies to mobile devices without additional client program installation in it. It also supports a dynamic service list which helps the mobile devices to search and to utilize the services through web browser in real time. A couple of examples such as a file search service and a print service with mobile devices have been demonstrated by using the Jini-Agent system.

• Spatial Information Research
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• v.17 no.4
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• pp.463-468
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• 2009

Geospatial interoperability has been pursued by propagating international standards and OGC standards. The NGIC, GeoConnection and other catalogue services are reviewed with aspect to metadata and search functions. Detailed metadata could be driven to users after finding what they want to have. Criteria for search were not fully overlapped with metadata, as simple and typical searches are prevailing. OGC catalogue service standards were made but catalogue services in Korea have been implemented in their own ways, not fully compliance-tested. Different domain technologies have been developed regardless of geospatial service, the relationship and integration methods between catalogue services and other core technologies are reviewed in the form of a pair table. Other issues in geospatial service were discussed in the level of raising issues.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.1
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• pp.39-51
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• 1998

In this paper, we propose signaling procedures amon network elements for a connection rerouting method which can reduce inter-switch handoff processing delay reduces the delay in the connection re-routing by reserving VPI/VCIs for possible inter-switch handoff calls in advance. Additionally, we mathematically analyze the signaling procedures and then suggest solutions to the relations with cluser size, network topoloty, handoff-request rete and handoff delay. With simulation, the solutions are validated. From numerical examples, we concluded taht handoff delay, one of the handoff QoSs, can be satisfied by adjusting the cluster size and network topology according to the handoff -request rate of service area. With our proposed signaling and analytic methods, we concluded that the connection rerouting method using cluster-sectoring effectively reduces the delay of inter-switch handoff processing than dynamic connection rerouting method. Our solutions are useful in guaranteeing the requested handoff delay (especially, inter-switch handoff delay) when the connection rerouting method is applied to ATM-based wireless/wired integrated network.

• Journal of KIISE:Information Networking
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• v.35 no.3
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• pp.183-191
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• 2008

In this paper, we propose Stream Control Transmission Protocol(SCTP) proxy which supports making an SCTP connection from a Corresponding Node(CN) to a Mobile Node(MN). Recently, mobility support in transport layer is proposed, which provides mobility in end-to-end way using the extension of SCTP. Mobile SCTP can provide handover to all applications that use SCTP as a transport protocol. However, current SCTP does not include independent location management service and can not make connection from a CN to a MN without assistance of other mobile protocols. To solve this problem, Proposed SCTP proxy interoperates with generic location management service and performs an address transformation to forward connection set up messages to the MN. Using the proposed proxy, SCTP can provide a complete mobility support including a connection setup to the MN and maintaining an existing connection.

• Fire Science and Engineering
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• v.32 no.5
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• pp.67-76
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• 2018

Among the firefighting facilities, the fire department connection during firefighting is more important than any other facilities at the firefighting site to supply fire water. This study examined the water supply port of a fire department connection installed at an apartment building based on the Standard for Fire Safety (NFSC 502). The time of discovery was measured by fire fighters who knew or did not know of the water supply port installed in the apartment building, and by separating day and night. To maximize the use of the fire department connection which is the full fire extinguisher facility used by the fire brigade based on the results of the experiment, the author suggests improvement proposals that can clarify the installation location and install the location sign of the fire department connection for the Standard for Fire Safety (NFSC 502).

• ETRI Journal
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• v.39 no.3
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• pp.345-352
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• 2017

Traffic management is a highly beneficial mechanism for satisfying quality-of-service requirements and overcoming the resource scarcity problems in networks. This paper introduces an optimal connection admission control mechanism to decrease the packet loss ratio and end-to-end delay in cognitive radio sensor networks (CRSNs). This mechanism admits data flows based on the value of information sent by the sensor nodes, the network state, and the estimated required resources of the data flows. The number of required channels of each data flow is estimated using a proposed formula that is inspired by a graph coloring approach. The proposed admission control mechanism is formulated as a semi-Markov decision process and a linear programming problem is derived to obtain the optimal admission control policy for obtaining the maximum reward. Simulation results demonstrate that the proposed mechanism outperforms a recently proposed admission control mechanism in CRSNs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.325-333
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• 1998

In this paper, conventional STM(Synchronous Transfer Mode) supports another traffics by using idle channels. Proposed mobile terminals are distributed independently at the BSA(Basic Service Area). So, MAC(Medium Access Control) specified on the wireless ATM networks, which is managing statistics multiplewing functions, idle channel's ultilization is maximized and multimedia service characteristic for conventional wired networks based fixed assignment scheme(connection-oriented) and random assignment scheme(connection-oriented) improving on dynamic reservation based MAC protocol.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.726-747
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• 2013

In order to support a large number of mobile stations (MSs) with statistical multiplexing in cellular networks, a random access scheme is widely used for uplink (UL) bandwidth request (BR). In the design of a random access based BR scheme, there are two important requirements: short connection delay and diverse Quality of Services (QoSs) support. Such requirements are crucial for IMT-Advanced systems like IEEE 802.16m to provide various types of fourth generation (4G) data services. IEEE 802.16m provides advanced UL BR schemes for non-real time polling service (nrtPS) and best-effort (BE) service to meet the requirements of short connection time and multiple QoS level support. In order to provide short connection time and multiple QoS support, three-step and differentiated BR procedures are adopted. In this paper, a novel modelling of IEEE 802.16m contention based BR scheme is proposed that uses a 2-dimensional discrete time Markov chain. Both the short access delay three-step BR procedures and normal five-step BR procedure are considered in the model. Our proposed model also incorporates the IEEE 802.16m differentiated BR procedure. With the proposed model, we extensively evaluate the performance of IEEE 802.16m BR for two different service classes by changing QoS parameters, such as backoff window size and BR timer. Computer simulations are performed to corroborate the accuracy of the proposed model for various operation scenarios. With the proposed model, accurate QoS parameter values can be derived for the IEEE 802.16m contention-based BR scheme.