• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.69-78
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• 2006

The client request scheduling techniques for web server can classified into the scheduling techniques considering a document size to be requested and not. The scheduling techniques considering a document site to be requested provides a better average response time than another As the size-based SRPT(Shortest Remaining Processing Time first) is typical, and the most of scheduling techniques considering a web document size are based on SRPT. Most of existing researches, however, have not considered the feature of HTTP/1.1 which enable the clients to request concurrent multiple inlined-contents in a HTML document via each connection. In this paper we propose a connection scheduling technique with the scheduling window which provides a better response time in HTTP/1.1. The experimental results show that the performance with the proposed approach is improved about $10\%$ more than the connection scheduling with SRPT.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.1
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• pp.135-139
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• 2014

In a connection-oriented packet switching network, the data communication starts after a virtual circuit is established between source and destination. The virtual circuit establishment time includes the queue waiting times in the direction from source to destination and the other way around. We use this two-way queueing delay to evaluate scheduling policies of a packet switching processor through simulation studies. In this letter, we also suggest user testing functions for the packet switching processor to manage virtual circuits. By detecting error causes, the user testing helps the packet switching processor provide reliable connection-oriented services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10B
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• pp.1665-1674
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• 2000

This paper treats the interworking of LAN-based networks like TCP over the ATM protocol stack in an ATM multicast session. Multicast connection will cause CIP since multicast group members form a connection tree by some tree methods and share the connected tree. The paper solve the CIP problem through a block-by-block transmission using ABT/IT method. ABT/IT RM cell is modified and block scheduling algorithm considering the traffic types is applied to each ATM switch using the enhanced RM cell. Block scheduling algorithm will avoid the indiscriminate discard of UBR traffic when congestion occurs and it can provide an efficient and fair service. The paper builds a block scheduler system and suggests the block scheduling algorithm for a multicast session in an ATM switch. UBR traffics arriving at the switch trough each VC is classified by the traffic type and stored at class buffer and thereafter indisciminately transmitted. When block scheduling algorithm is applied it will improve the UBR traffic performance such as end-to-end delay cell block loss ration etc. This paper evaluated the performance of block scheduling algorithm through the simulation using the C language and data structure.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.7_8
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• pp.352-358
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• 2003

A cluster of servers is the most promising solution to provide highly scalable and highly available network services with low implementation cost. One of popular solutions is using dispatcher as a request distributor. However this solution has the problem that is can be the bottleneck or single-point of failure point of itself. ONE-IP, the previous work, solves this serious problem by using broadcast message for distributing the request packet in LAN. Using simple scheduling technique, in addition, the overhead due to dispatching the request becomes minimal. However, as ONE-IP using very simple static scheduling algorithm, it would spread the request among servers unevenly and downgrades the cluster performance consequently. In this paper, we propose an improved TCP connection scheduling technique solving this unbalanced distributing problem. Using Round-Robin(RR) scheduling instead of hashing clients IP address, proposed technique can more evenly distribute incoming service requests among the servers. Experiments show average 3.8% improved performance in throughput compared to original ONE-IP technique.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.161-162
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• 2008

본 연구는 무선 통신 시스템에서 다수의 가입자 또는 connection이 존재할 때 트래픽 패킷의 전송 우선순위를 결정하는 방법에 관한 것으로, 특히 시스템 상에 QoS를 만족해야하는 실시간 트래픽 전송을 요구하는 connection과 비실시간 트래픽 전송을 요구하는 connection이 동시에 존재하는 경우에 대한 것이다. 패킷 기반의 시스템에서 각 frame에 할당하는 트래픽 패킷의 우선순위를 결정하는 방법이 반드시 존재해야 한다. 가입자 당 전송하는 트래픽 패킷은 실시간 트래픽과 비실시간 트래픽으로 구분할 수 있다. 실시간 트래픽 전송의 경우 허용전송지연시간 내에 전송하지 못하는 패킷이 발생할 확률을 일정 수준 이하로 유지하는 것이 중요하기 때문에, 일반적으로 비실시간 트래픽에 비해 우선순위를 가진다. 본 연구에서는 실시간 트래픽에 대해 허용전송지연시간 초과 패킷 확률을 일정 수준 이하로 유지하면서 미레적인 방법을 통해 비실시간 트래픽 패킷에 대한 실시간 트래픽 패킷의 우선순위를 제한하여 시스템의 평균 throughput을 향상시키는 것을 목적으로 한다. 시뮬레이션을 통해 분석한 결과 비례적인 방법을 통해 실시간 트래픽 패킷을 보다 효율적으로 전송할 수 있다는 것을 검증할 수 있었다.

• Journal of Electrical Engineering and information Science
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• v.3 no.1
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• pp.1-7
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• 1998

High-Level synthesis of digital circuits calls for automatic translation of a behavioral description to a structural design entity represented in terms of components and connection. One of the critical steps in high-level synthesis is to determine a particular scheduling algorithm that will assign behavioral operations to control states. A new scheduling algorithm called Data Availability Scheduling (DAS) for high-level synthesis is presented. It can determine an appropriate scheduling algorithm and minimize the number of states required using data availability and dependency conditions extracted from the behavioral code, taking into account of states required using data availability and dependency conditions extracted from the behavioral code, taking into account resource constraint in each control state. The DAS algorithm is efficient because data availability conditions, and conditional and wait statements break the behavioral code into manageable pieces which are analyzed independently. The output is the number of states in a finite state machine and shows better results than those of previous algorithms.

• Journal of KIISE:Information Networking
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• v.28 no.3
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• pp.447-453
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• 2001

In this paper, we consider the scheduling of SE(switching element)-disjoint multicasting in photonic Banyan-type switching networks constructed with directional couplers. This ensures that at most, one connection holds each SE in a given time thus, neither crosstalk nor blocking will arise in the network. Such multicasting usually takes several routing rounds hence, it is desirable to keep the number of rounds(i.e., scheduling length) to a minimum. We first present the necessary and sufficient condition for connections to pass through a common SE(i.e., make crosstalk) in the photonic Banyan-type networks capable of supporting one-to-many connections. With definition of uniquely splitting a multicast connection into distinct subconnections, the crosstalk relationship of a set of connections is represented by a graph model. In order to analyze the worst case crosstalk we characterize the upper bound on the degree of the graph. The successor paper(Part II)[14] is devoted to the scheduling algorithm and the upper bound on the scheduling length. Comparison with related results is made in detail.

• The Journal of Korean Association of Computer Education
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• v.11 no.3
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• pp.91-99
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• 2008

In recent years, wireless networks have been widely deployed and the use of mobile devices has been popularized. As a result, mobile devices are increasingly considered as a resource of the Grid However, there are some problems such as unstable wireless communication and disconnection of mobile devices caused by movement in Mobile Grid Therefore, a scheduling method allocating jobs to the mobile devices should progressively deal with this problem The existing scheduling methods in Mobile Grid have mainly focused on the connection time of mobile devices. The connection time of mobile devices shows typically a regular pattern according to a user's living environments such as vacation/class in school, weekday/weekend in work, and so on. In this paper, we analyze statistics information for the utilization patterns of mobile devices and propose global and local scheduling methods for Mobile Grid, based on the analyzed utilization patterns.

• 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 Platform Technology
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• v.9 no.4
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• pp.51-59
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• 2021

In this paper, we propose a location-based service that the user's location is known by connection history to WI-FI AP installed in a facility known its location previously. The location-based service proposed in this paper manages job processing states of technicians who inspect and maintain the facility like elevator by using worker's location and arrival time information. The job scheduling management method proposed in this paper is based on previously scheduled arrival time and actual arrival time to a target facility. And we experimentally implemented the inspection and maintenance system of an elevator to show the feasibility of job schedule management based on location and arrival time information acquired from Wi-Fi AP connection history. Our experimental implementation shows that our proposed method is usefulness in the field of the inspection and maintenance of a facility.