• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.660-667
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• 2000

This paper aims at analyzing the traffic of CDMA base station. RTD(Round Trip Delay) method, used for the study, is one of the developed tool for calculating the call setup time between the BTS(Base Station TransceiverSubsystem) and mobile station.We compare the calculated call setup time in air with the field experiments.And we suggest the RTD method for dividing the traffic of the connected repeater from that of the BTS, andwe can testify it by the experiment which analyze the difference of the received time between the base stationand the repeater including the forced delay elements.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.174-179
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• 2005

In the SONET/SDH based ASON, one VC3 connection contains 21 VC12 calls. Hence, it can serve up to 21 VC12 calls. When a new VC12 call arrives, if there exists at least one available VC3 connection in the network, that VC12 call is severed immediately. However, if there is no available VC3 connection, that VC12 call has to wait a certain time, called setup latency, for the a new VC3 connection to be established. This is inconvenient for the customers. On the other hand, if there are more VC3 connections than the network requires, this can waste network resources. In this paper, we proposed the solution for these problems. In order to reduce the number of VC12 calls which have to wait, we setup a new VC3 before all VC12 time slots are occupied. Furthermore, to avoid the waste of the network resources, we do not establish all VC3 connections at the same time, but do establish step by step.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.2
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• pp.169-175
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• 2021

The lot sizing problem(LSP) is a hard problem that classified as non-deterministic(NP)-complete because of the polynomial-time optimal solution algorithm is unknown yet. The well-known W-W algorithm can be obtain the solution within polynomial-time, but this algorithm is a very complex, therefore the heuristic approximated S-M algorithm is suggested. This paper suggests O(n) linear-time complexity algorithm that can be find not the approximated but optimal solution. This algorithm determines the lot size Xt∗ in period t to the sum of the demands of interval [t,t+k], the period t+k is determined by the holding cost will not exceed setup cost of t+k period. As a result of various experimental data, this algorithm finds the optimal solution about whole data.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.6
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• pp.117-125
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• 2004

This paper describes the test technique for the full-scale airframe durability test according to the military handbook(MIL-HDBK-1530) and ASIP(Aircraft Structure Integrity Program) to evaluate structural integrity and to obtain basic data for IPA(Initial Production Approval) of the Korean advanced trainer(T-50). This paper covers the full-scale airframe floating setup technique, the optimized test load simulation method, test rig design technique, test setup design and installation techniques, test safety device design and operation technique, and durability test results. As 1st life durability test was successfully performed, it was confirmed that this method is available in a full-scale airframe structural test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.929-935
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• 2008

As internet telephony services based on Session initiation Protocol (SIP) enter the spotlight as marketable technology, many products based on SIPs have been developed and utilized for home and office telephony services. The call connection of an internet phone is classified into specific call connections and group call connections. Group call connections have a forking function which delivers the message to all of the group members. This function requires excessive message control for a call connection and creates heavy traffic in the network. In the internet cail system model. most of the call-setup messages are directed to the proxy server during a short time period. This heavy message load brings an unwanted delay in message processing and. as a result, call setup can not be made. To solve the delay problem, we simplified the analysis of the call-setup message in the proxy server, and processed the forking function distributed for the group call-setup message. In this thesis, a new system model to minimize the load is proposed and the subsequent implementation of this model demonstrates the performance improvement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.1
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• pp.41-47
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• 2002

Path setup considering QoS is one of the main problems to solve in Internet traffic engineering. In network restoration that is one of the traffic engineering components, to establish a backup path or backup path for a working path to be protected is the main task. The backup path should have enough bandwidth to guarantee the working paths. Thus this work requires the QoS routing solution that is to set up a backup path as well as a working path at the same time provisioning enough bandwidth. In this paper, we propose an algorithm to setup a backup path that shares the bandwidth of other backup paths whose working path does not pass along the same link with the working path we are considering. In this way we can reduce much bandwidth consumption caused by setting up backup paths. We also analyze the disjoint path computation algorithms. Finally we show simulation results how the algorithm can reduce the bandwidth consumption and how it will affect blocking when we setup paths.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.117-126
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• 2015

This paper is to analyze an integrated production and inventory model in a single-vendor multi-buyer supply chain. The vendor is defined as the manufacturer and the buyers as the retailers. The product that the manufacturer produces is supplied to the retailers with constant periodic time interval. The production rate of the manufacturer is constant for the time. The demand of the retailers is constant for the time. The cycle time of the vendor is defined as the elapsed time from the start of the production to the start of the next production, while the cycle times of the buyer as the elapsed time between the adjacent supply times from the vendor to the buyer. The cycle times of the vendor and the buyers that minimizes the total cost in a supply chain are analyzed. The cost factors are the production setup cost and the inventory holding cost of the manufacturer, the ordering cost and the inventory holding cost of the retailers. The cycle time of the vendor is investigated through the cycle time that satisfies economic production quantity with the production setup cost and the inventory holding cost of the manufacturer. An integrated production and inventory model is formulated, and an algorithm is developed. An numerical example is presented to explain the algorithm. The solution of the algorithm for the numerical examples is compared with that of genetic algorithm. Numerical example shows that the vendor and the buyers can save cost by integrated decision making.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.35-39
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• 2008

This paper considers the sequencing of products in mixed model assembly lines. The sequence which minimizes overall utility work in car assembly lines reduce the cycle time, the number of utility workers, and the risk of conveyor stopping. The sequencing problem is solved using Tabu Search. Tabu Search is a heuristic method which can provide a near optimal solution in real time. Various examples are presented and experimental results are reported to demonstrate the efficiency of the technique.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.204-207
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• 2000

Verification is one of the most critical and time-consuming tasks in today's design process. This paper describes the basic idea of Co-verification and the environment setup for the design of DVD Servo with TeakLite DSP core by using Seamless CVE, Hardware/software Co-verification too1.

• IE interfaces
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• v.22 no.1
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• pp.73-84
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• 2009

In this paper, we propose a dispatching algorithm for constructing a Factory Operating System (FOS) which can operate semiconductor fabrication factories more efficiently and effectively. We first define ten dispatching criteria and propose two methods to apply the defined dispatching criteria sequentially and simultaneously (i.e. fixed dispatching architecture). However the fixed type methods cannot apply the criteria adaptively by considering changes in the semiconductor fabrication factories. To overcome this type of weakness, an adaptive dispatching architecture is proposed for applying the dispatching criteria dynamically based on the factory status. The status can be determined by combining evaluation results from the following three status criteria; target movement, workload balance, and utilization rate. Results from the shop floor in past few periods showed that the proposed methodology gives a good performance with respect to the productivity, workload balance, and machine utilization. We can expect that the proposed adaptive dispatching architecture will be used as a useful tool for operating semiconductor fabrication factories more efficiently and effectively.