• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.60-67
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• 2017

A baggage handling system (BHS) in airport is an unified system for moving the passengers' baggage in designated time. Input baggage from the check-in counter travels to the baggage claim area or cargo handling terminal through this system. In particular, entryway BHS consists of conveyors, X-ray and sorters such as tilt-tray to send the baggage to departing airplane and it could have various problems for handling certain amount of baggage in restricted time such as baggage jamming at certain merge point. This causes systemic error such as delay of the time, omissions of the baggage and even breakdown of the equipment and inefficiency. Also the increasing maximum time of the baggage passing through the BHS could delay the flight schedule and finally decrease the service level. Thus, the algorithm for controlling the flow of the merge is essential to the system. The window reservation algorithm is the one of the most frequently used methods to control the merge configuration. Above all, the reserve location, so called reserve ahead point, that allocates the window is important for the performance of the algorithm. We propose the modified window reservation algorithm and the best reserve locations by changing the reserve ahead point in the induction conveyors. The effect of various reserve ahead points such as the capacity and utility of the system were analyzed and the most effective reserve ahead point combination was found. The total baggage processing time and the utilization of the tilt-tray are properly considered when choosing the optimal Reserve ahead point combination. In the layout of this study, the configuration of four conveyors merged into one tilt-tray is studied and simulation analysis is done by AutoMod(R), 3D simulation software. Through the simulation, the window reservation algorithm is effectively operated with the best combination of reserve ahead point which reduces the maximum baggage travel time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.9
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• pp.822-830
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• 2012

The most representative research network in Korea, KREONET has developed the NSI based NSA (Network Service Agent) technology. The developed NSA supports web service and provides services for reservation, provision, release and termination of network resource, whenever users want to utilize them. In this paper, the system blocks of the developed NSA and flows of NSI interface massage are presented firstly, Also, service test results for NSI connection reservation is given through internet communication of the web portal system to operate as the RA NSA and the NSA, Finally, it is confirmed that reservation, provision, release and termination of network resource can be established through NSI messages based on reservation information from user, between the web portal and the NSA.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.1
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• pp.32-43
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• 2000

In this paper, we investigate the existing medium access control (MAC) protocols to integrate the voice and data services in packet-based CDMA networks and furthermore, propose a new approach to circumvent the operational limits inherent in them. We propose the $P^2R$-CDMA (Prioritized Packet Reservation Code Division Multiple Access) protocol for the uplink in the synchronous multi-code CDMA system, which employs the centralized frame-based slot reservation along with the dynamic slot assignment in the base station using the QoS-oriented dynamic priority of individual terminal. The simulation results show that, as compared with the existing scheme based on the adaptive permission probability control (APC), the proposed approach can significantly improve the system capacity while guaranteeing the real-time requirement of voice service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.766-774
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• 2004

The future mobile communication system can support not only voice but also multimedia applications such as data, image and video. It requires greater resources than the voice-oriented mobile system. Efficient resource reservation and hand-over schemes are necessary to maintain the same QoS of transmitted multimedia traffic because the QoS may be defected by some delay and information loss during hand-over. This paper proposes a resource reservation scheme to accommodate multimedia traffics in mobile multimedia networks. In our scheme the position of mobile is estimated in two steps, that is, sector estimation and zone estimation. With this position information, the moving direction is determined. According to simulation results, our scheme provides a better performance than conventional methods.

• Journal of Internet Computing and Services
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• v.4 no.5
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• pp.61-68
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• 2003

In this paper, we propose a wireless MAC protocol named APRMA, which is capable of supporting the ABR type data service and Maximizing channel utilization. Data terminals with random data packets are not provided slot reservation with PRMA protocol. That is, slot reservation is applicable to the time constraint voice packet exclusively. But the reservation scheme have to be performed for loss sensitive data packet, and contended their quality of service, Therefore, in wireless MAC, reservation technique has to be used for both voice and data services. So the terminal which wants to request for ABR type service, is allocated a minimum bandwidth from system for the first time, If the system have some extra available bandwidth, ABR terminals would acquire additional bandwidth slot by slot, As a result, APRMA protocol can support the data service with loss sensitivity and maintain their channel utilization high.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1B
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• pp.7-16
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• 2005

Resource Reservation Protocol(RSVP) can provide Quality-of-Service(QoS) guarantees for real-time services in wired networks. However, RSVP suffers from mobility problem in the mobile Internet. Therefore, to provide seamless QoS services, it is needed that a mobile node makes a reservation everywhere it visits. Recently, many protocols have been proposed to provide QoS guarantees through advance resource reservation. But, these proposals have problems with a waste of bandwidth and the signaling overhead due to advance resource reservation. In this paper, we propose new advance resevation protocol, Proportional Aggregate RSVP(PA-RSVP) to minimize the resource reservation bandwidth and the signaling overhead in the mobile Intemet while providing QoS guarantees. Based on the performance evaluation, we show that the proposed protocol provides an improved performance over existing protocols under various system conditions.

• Journal of Korea Multimedia Society
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• v.15 no.12
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• pp.1464-1474
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• 2012

In this paper, we propose a QoS (Quality of Service)-aware and cooperative resource reservation scheme using cross-layer link adaptation for wireless high definition video transmission through UWB (Ultra Wide Band) network with D-MAC (Distributed Medium Access Control). A wireless high definition video transmission system usually requires stable high throughput even without line-of-sight, e.g., a destination device in another room separated by a wall. Since the WiMedia D-MAC supporting DRP (Distributed Reservation Protocol) scheme causes lots of DRP resource reservation conflicts due to failure of beacon detection in wireless channel environment, overall performances of the WiMedia D-MAC can be deteriorated. And the current WiMedia MAC standard has not considered QoS provisioning even though QoS parameters such as a range of service rates are provided to each traffic stream. Therefore, we propose Relay DRP protocol with QoS-based relay node selection criterion, which makes a relay path to avoid DRP resource reservation conflicts and guarantee QoS more stably through cross-layer link adaptation of cooperative relay transmission scheme and is compliant with the current WiMedia D-MAC protocol. Simulation results demonstrate performance improvements of the proposed method for throughput and QoS provisioning.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.50-59
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• 2014

In this paper, we develop an efficient approach to solve a multiple-item budget-constraint newsboy problem with a reservation policy. A conventional approach for solving such problem utilizes an approximation for the evaluation of an inverse of a Gaussian cumulative density function when the argument of the function is small, and a heuristic method for finding an optimal Lagrangian multiplier. In contrast to the conventional approach, this paper proposes more accurate method of evaluating the function by using the normalization and an effective numerical integration method. We also propose an efficient way to find an optimal Lagrangian multiplier by proving that the equation for the budget-constraint is in fact a monotonically increasing function in the Lagrangian multiplier. Numerical examples are tested to show the performance of the proposed approach with emphases on the behaviors of the inverse of a Gaussian cumulative density function and the Lagrangian multiplier. By using sensitivity analysis of different budget constraints, we show that the reservation policy indeed provides greater expected profit than the classical model of not having the reservation policy.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.4
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• pp.574-579
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• 2014

A lysozyme gene from breast of Tibetan sheep was successfully expressed by secretion using a-factor signal sequence in the methylotrophic yeast, Pichia pastoris GS115. An expression yield and specific activity greater than 500 mg/L and 4,000 U/mg was obtained. Results at optimal pH and temperature showed recombinant lysozyme has higher lytic activity at pH 6.5 and $45^{\circ}C$. This study demonstrates the successful expression of recombinant lysozyme using the eukaryotic host organism P. pastoris paving the way for protein engineering. Additionally, this study shows the feasibility of subsequent industrial manufacture of the enzyme with this expression system together with a high purity scheme for easy high-yield purification.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.2
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• pp.105-115
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• 2005

By committing to a long-term replenishment contract, buyers can purchase a product at a lower price from a supplier who is less pressured to find new customers due to the long-term contract and can charge a discounted price. We develop an analytical model from the buyer's perspective to investigate a capacity reservation contract. We are considering the system with a single supplier and a buyer. The buyer can purchases any desired amount from a spot market at a higher price in addition to the contracted amount. For such a system, we propose an algorithm to derive the optimal contract terms. The result of computational experiments shows that the algorithm finds the global optimum solution in a resonable amount of time.