• Annual Conference of KIPS
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• 2000.04a
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• pp.538-543
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• 2000

DS(Differentiated Service)에서는 RSVP와 같이 개별 flow에 대한 QoS제공이 아닌 flow들의 집합(aggregate)으로 차등적인 서비스를 제공하는 방법이다. 확장성을 고려한 이러한 방안은 광역백본망 에서와 같이 수천, 수만의 flow들에 대해 서비스를 제공하고자 할때 flow들을 집합(aggregate)화 하여 차등적인 서비스를 제공하고자 하는 것은 매우 큰 의미가 있다고 할 수 있다. 하지만 DS에서는 Token Bucket 방법을 사용하여 트래픽 스트림을 측정하는 이유로 불특정 flow에 대해 심각한 QoS손실을 야기할 수 있다. 본 논문에서는 자원공유의 공정성을 기여하기 위해 Traffic Conditioner에서 사전 모니터링 방법을 사용하고 이 모니터링 결과를 Weighted Fair Queuing의 파라메터로 사용하여 잉여 자원을 효율적으로 사용하는 방안을 제시한다.

• Annual Conference of KIPS
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• 2014.11a
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• pp.215-217
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• 2014

In Software Defined Network (SDN), data plane and control plane are decoupled. Dummy switches on the data plane simply forward packet based on the flow entries that are stored in its flow table. The flow entries are generated by a centralized controller that acts as a brain of the network. However, the size of flow table is limited and it can conduct a security issue related to Distributed Denial of Service (DDoS). Especially, it related to resource attack that consumes all flow table resource and consumes controller resources. In this paper, we will analyze the impact of flow table limitation to the controller. Then we propose an approach that is called Flow Table Management to handle flow table limitation.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.928-932
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• 1987

Successful operation of a computer network Is dependent on the adequate routing and flow control. Routing and flow control algorithms are studied together rather than as isolated mechanism. In this paper, we discuss the effect of the flow control and routing algorithms.

• Water for future
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• v.29 no.6
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• pp.141-154
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• 1996

A computer program is developed in order to investigate the fluid flow and heat ransfer of a water body in a 2-D vertical rectangular coordinate. The specific purpose of this study is to obtain a physical insight of several fluid flow problems which occur in a lake and the water and wastewater treatment facility like a primary clarifier. The performance of computer program developed is successfully evaluated by the comparison of other two experimental and computational data in open literature : the first comparison is made against the numerical data associated with the cooling water discharge and the other is numerical and experimental works for the primary clarifier of Sarina City at Ontario. Further, the computer program is applied to investigate the feature of lake flow, say lake turnover, and 2-D vertical channel flow in terms of temperature, wind velocity and flow rate, etc. The computational results appear to be physically acceptable and consistent. The computer program developed in this study shows the possibility of the viable tool to figure out the flow characteristics of water reservoir.

• The Journal of Korean Association of Computer Education
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• v.12 no.1
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• pp.15-22
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• 2009

Computer programming language learning has an educational effect on improving the high level abilities such as a logical thinking ability and a problem solving ability as well as on understanding a computer working process through the process of programming and debugging tasks. In this study, the Flow Theory is applied for the students to have inner learning motive and continue their learning in the programming language learning. For this, we developed teaching-learning strategies applied by Flow elements, and designed to the WBI. We also applied to the actual teaching-learning field designed WBI and verified the effects on the changes in the learner's Flow level and academic achievement. The result of verification, WBI learning applied by Flow Theory is effective on improving Flow level, making the students have the learning goal and spirit of challenging, forming feedbacks. Also Flow experiences have effect on improving academic achievement(programming ability) through the positive effects on the results of the learning.

• The Transactions of the Korea Information Processing Society
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• v.6 no.3
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• pp.750-757
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• 1999

The protocol conformance testing is to check whether an implementation of a protocol conforms to its specification. And it is important to improve the interoperability of protocol and the efficiency of cost. In general, protocol is composed of the control flow representing observable behaviors and the data flow representing internally used variables. Until now, research for generation of test suite has been realized only consideration the control flow of protocol or separation control flow from data flow. Case of considering control flow, contents of test was simple and definite. Length of test was short. But it was of little application, and it didn't manage each kind errors in data flow. Therefore, we must generate test case that can manage control and data flow. So, anomaly of variable must be removed for efficient conformance testing. Therefore in this dissertation, we proposed algorithm which can remove anomaly of variable for efficient conformance testing. And it showed that anomaly of variable was got rid of applying this algorithm to real protocol.

• Annual Conference of KIPS
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• 2002.04b
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• pp.1555-1558
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• 2002

SIP는 간단한 텍스트 기반의 응용계층 프로토콜로서, H.323을 대체할 수 있는 프로토콜이다. SIP는 인터넷 환경에 그대로 접목 할 수 있고, 새로운 기능 및 부가서비스의 제공이 용이하다는 장점을 가지고 있다. SIP 프로토콜은 요청메시지와 그에 대한 응답으로 구성되는 Request-Response방식이다. SIP의 장점은 유일한 개인 ID를 이용하여 장소와 단말기에 구애를 받지 않고 SIP서비스를 제공받을 수 있는 Personal Mobility Service에 있다. 본 논문에서는 User Agent와 프록시 서버(Proxy Server) 사이에 이루어지는 SIP 트랜잭션(Transaction)을 Call-Flow를 통해서 살펴보고자 한다.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.413-423
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• 2022

The NHIS provides free or highly subsidized healthcare to all people by providing financial fortification. However, the financial sustainability of the scheme is threatened by numerous factors. Therefore, this work sought to provide a solution to process claims intelligently. The provided Petri net model demonstrated successful data flow among the various participant. For efficiency, scalability, and performance two main subsystems were modelled and integrated - data input and claims processing subsystems. We provided smart claims processing algorithm that has a simple and efficient error detection method. The complexity of the main algorithm is good but that of the error detection is excellent when compared to literature. Performance indicates that the model output is reachable from input and the token delivery rate is promising.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4887-4907
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• 2017

Accurate traffic flow forecasting is critical to the development and implementation of city intelligent transportation systems. Therefore, it is one of the most important components in the research of urban traffic scheduling. However, traffic flow forecasting involves a rather complex nonlinear data pattern, particularly during workday peak periods, and a lot of research has shown that traffic flow data reveals a seasonal trend. This paper proposes a new traffic flow forecasting model that combines seasonal relevance vector regression with the hybrid chaotic simulated annealing method (SRVRCSA). Additionally, a numerical example of traffic flow data from The Transportation Data Research Laboratory is used to elucidate the forecasting performance of the proposed SRVRCSA model. The forecasting results indicate that the proposed model yields more accurate forecasting results than the seasonal auto regressive integrated moving average (SARIMA), the double seasonal Holt-Winters exponential smoothing (DSHWES), and the relevance vector regression with hybrid Chaotic Simulated Annealing method (RVRCSA) models. The forecasting performance of RVRCSA with different kernel functions is also studied.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1295-1299
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• 2003

The Mass Flow Controller(MFC) has become crucial in semiconductor manufacturing equipments. It is an important element because the quality and the yield of a semiconductor process are decided by the accurate flow control of gas. Therefore, the demand for the high speed and the highly accurate control of MFCs has been requested. It is hard to find an article of the control algorithm applied to MFCs. But, it is known that commercially available MFCs have PID control algorithms. Particularly, when the system detects the flow by way of heat transfer, MFC control problem contains the time delay and the nonlinearity. In this presentation, MFC control algorithm with the superior performance to the conventional PID algorithm is discussed and the superiority is demonstrated through the experiment. Fuzzy controller was utilized in order to compensate the nonlinearity and the time delay, and the performance is compared with that of a product currently available in the market. The control system, in this presentation, consists of a personal computer, the data acquisition board and the control algorithm carried out by LabWindows/CVI program on the PC. In addition, the method of estimating an actual flow from sensor output containing the time delay and the nonlinearity is presented. In conclusion, according to the result of the experiment, the proposed algorithm shows better accuracy and is faster than the conventional controller.