• The Transactions of the Korea Information Processing Society
• /
• v.6 no.3
• /
• pp.710-721
• /
• 1999

In this paper, we have designed and implemented a parameter extraction system for analyzing Internet using SNMP. The extraction system has two modules; one is collection request module, and the other is analysis request module. The collection request module generates a polling script, which is used to collect management information from the managed system periodically. With this collected data, analysis request module extracts analysis parameters. These parameters are traffic flow analysis, interface traffic analysis, packet traffic analysis, and management traffic analysis parameter. For management activity, we have introduced two-step-analysis-view. One is Summary-View, which is used find out malfunction of a system among the entire managed systems. The Other is Specific-View. With this view we can analyze the specific system with all our analysis parameters. To show available data as indicators for line capacity planning, network redesigning decision making of performance upgrade for a network device and things like that.

• Journal of Korea Multimedia Society
• /
• v.16 no.8
• /
• pp.954-961
• /
• 2013

To enhance the efficiency of network, content-centric networking (CCN), one of future Internet architectures, allows network nodes to temporally cache transmitted contents and then to directly respond to request messages which are relevant to previously cached contents. Also, since CCN uses a hierarchical content-name, not a host identity like source/destination IP address, for request/response packet routing and CCN request message does not include requester's information for privacy protection, contents-providers/ network nodes can not identify practical requesters sending request messages. So to send back relevant contents, network nodes in CCN records both a request message and its incoming interfaces on Pending Interest Table (PIT). Then the devices refer PIT to return back a response message. If PIT is exhausted, the device can not normally handle request/response messages anymore. Hence, it is needed to detect/react attack to exhaust PIT. Hence, in this paper, we propose improved detection/reaction schemes against attacks to exhaust PIT. In practice, for fine-grained control, this proposal is applied to each incoming interface. Also, we propose the message framework to control attack traffic and evaluate the performance of our proposal.

• The Transactions of the Korea Information Processing Society
• /
• v.7 no.8S
• /
• pp.2608-2619
• /
• 2000

This paper proposes the Handover Scheme for the mobile and describes the result of the performance analysis. In the conventional scheme of handover request, the withdrawal of terminal may occur because handover request is performed based on fixed signal level without considering network load and terminal mobility. The proposed scheme offers the minimization of withdrawal and handover blocking probability by means of the handover request of terminal based on the network load and terminal mobility. Conventional handover scheme has the sequential procedure that network performs resource check and path rerouting on the handover by MT(Mobile Terminal). Proposed handover scheme pre-processes the resource check before the handover request by predicting the handover request timo so that handover latency can be reduced. Moreover, path optimization is executed after the completion of handover in order to reduce handover latency. The rdduction of handover latency prevents the dropping of service by minimizing backward handover blocking. In summary, we propose the prediction of handover request time and decision method based on terminal, validating the performance of proposed scheme considering various cases of simulation.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.57-60
• /
• 2003

IEEE 802.16 Wireless MAN standard specifies the air interface of fixed point-to-multipoint broadband wireless access systems providing multiple service. Among the service classes supported by the wireless MAN, the BE class is ranked on the lowest position in priority and is usually deployed by multicast and broadcast polling MAC scheme. In provisioning such BE service, the delay performance is influenced by a number of components including restrictions on resource request per SS, the number of request opportunities in upward frame, scheduling requests at BS, and contention resolution method. As candidate components of MAC function for BE service, we propose single and multiple request schemes (for controling the number of requests per SS), exhaustive and limited request schemes (for regulating the amount of grant per request) and FCFS, H-SMF, pure SMF, SS-wise Round Robin, and pure Round Robin (for scheduling requests at BS). Then, we construct MAC schemes by combining the above components and evaluate the delay performance exhibited by each MAC scheme using a simulation method. From numerical results, we investigate the effect of MAC components on average delay and delay variation and observe the dissonance on collision reduction in a resource - limited environment.

• Korean Institute of Interior Design Journal
• /
• v.19 no.6
• /
• pp.206-213
• /
• 2010

This study, for church architectural amenities for the aged, with a base of 'laws on securing promotion of convenience for the disabled, aged, and pregnant women,' would like to propose improvement program after figuring out church worker (priest)'s willingness for amenities improvement, request of the aged church members, and level of request by different ages of the aged church members and total number of church members. The scope of geographical range for the study is limited to Northern side of Han River in Seoul and the churches with its own building having 500 to 3,000 people attending services, and implementation range, with a base of laws on promotion of convenience, separates specific items into mediation facility, interior facility, sanitary facility, and other facilities. The study selected 40 workers in church and 339 aged church members as subjects. As analysis method for the study, we have measured reliance level of questions by performing reliance test on each question, and performed frequency analysis in order to observe church worker's willingness to improve and request level of the aged church members. And, in order to find out the difference on opinion by the aged church members and total number of church members, we have performed "One way ANOVA," that verifies average difference. For evidence analysis we have verified all of them in attention level of p<.05, and for statistics analysis we have analyzed them using SPSSWIN 12.0 program. We are proposing improvement program based on study and analysis as next: First, since most of church workers have strong willingness to improve amenities we have learned that it is very optimistic to see improvements on church's amenities in the future. Second, since the aged church members' level of request was high on 3 of mediation facilities, elevators, and restrooms, it is desirable to improve mainly with these facilities. Third, the result on level of request for facilities based on the total number of church members revealed that the churches with 1,000-2,000 members have the highest level of request. Thus, we feel that the churches with 1,000-2,000 members should try harder to improve compared with churches with different number of members. Fourth, since the level of request on church amenities by different age group showed that the age group with 65-70 had the highest level of request on all facilities, except elevators, there are needs to apply the opinions of this age group more in depth based on this result.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.1-6
• /
• 2014

This paper proposes a mobile content curation service to collect various online/offline publications. The company publishes one-time topic information to a broker server in advance and customer curates topic information on a mobile device by requesting it. The main characteristics of the proposed service are: it is based on request/response model rather than existing publish/subscribe model, can easily specify topic information by input string without QR code or audio recognition, and retrieves all of topic information anywhere anytime by storing it on mobile device. This service can be used for second screen campaign for TV and various online/offline events.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.69-72
• /
• 2007

DOCSIS 3.0 Protocol is proposed to make the advance of HFC network. In the DOCSIS based network, the upstream frame is divided into contention section reservation section. CMs to have packets send request messages through the contention section. That two or more CMs sends Request message at the same contention slot makes collison. In this paper, are propose the contention section establlish at algorithm considering of channel-bonding mechanism that is the primary technique of DOCSIS 3.0. Results of simulation display better performance int the number of contention slots and the utilization of contention section.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.3B
• /
• pp.105-113
• /
• 2005

In this paper, through the implementation of the application service, we evaluated the feasibility and availability of the staged application service platform, which is based on the sharing of the PVM cluster. Application service platform provides three managers for dividing the request processing steps into two stages, such as a request processing stage and a service providing stage. Three managers and its relation to the divided stages are as follows, service manager and load manager to distribute the request in front-end server for a request processing stage, job manager in clustered(back-end) servers for a service providing stage. The experiment shows that the staged application service platform provides more stable and scalable characteristics and better performance improvement on the dynamic load changes than the single server system. And also it shows that real application service system can be implemented easily without modification of the proposed service platform.

• The KIPS Transactions:PartB
• /
• v.10B no.7
• /
• pp.847-852
• /
• 2003

This paper implements MOD system using multicast delivery. Conventional system provide server-based system in multicast delivery but implemented system provides on-demand client-based multicast system. The scheduler aggregates clients' request and it generate multcast group addresses and port numbers according to requested video items and service request time. Then it transmits immediately multicast address to MOD server and client who request service. And then MOD server transmits requested streams with a multicast group address and the client joins the group automatically. The scheduler assigns the same multicast group address when other clients request an identical video within the same scheduling duration. The system can reduce load of server and support many clients at the same time.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.11
• /
• pp.1229-1234
• /
• 2010

High quality and high speed multimedia services will be required in the next generation mobile communications. To satisfy these services, powerful error correction techniques are used. ARQ(Auto Repeat Request) techniques, aspects of the throughput, and FEC(Forward Error Correct) techniques have disadvantages in terms of reliability. H-ARQ(Hybrid Auto Repeat Request) systems have been studied extensively as a solution of these disadvantages. In this paper introduce double layer coding and H-ARQ type, proposed H-ARQ system using double layer coding methods. Simulate BER performance and throughput. And we suggest that according to channel condition suitable H-ARQ type.