• Journal of Korean Society of Transportation
• /
• v.23 no.7 s.85
• /
• pp.111-123
• /
• 2005

A network design model has been proposed. which represents a transportation facility investment decision problem. The model takes the discrete hi-level programming form in which two types of decision makers, government and travelers, are involved. The model is characterized by its ability to address the total social costs occurring in transportation networks and to estimate the equilibrium link volumes in multi-modal networks. Travel time and volume for each link in the multi-modal network are predicted by a joint modal split/traffic assignment model. An efficient solution algorithm has been developed and an illustrative example has been presented.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.263-266
• /
• 1995

Comtputer Aided Process Planning(CAPP) has been emerged as playing a key role in Computer Integrated Manufactunng(CIM) as the most critical link to integrate CAD and CAM. A modified variant CAPP system based on process planning rule base is developed in this paper. This CAPP system generates process plans automatically according to the GT code data provided as input. In order to execute process planning, various process planning rules are constructed in the form of decision tree and the inference engine that extracts the process plan based on the tree-structured rules are implemented.

• Journal of Korea Multimedia Society
• /
• v.19 no.11
• /
• pp.1829-1836
• /
• 2016

Today, the application area and scope of FANET(Flying Ad Hoc Network) has been extended. As a result, FANET related research are actively conducted, but there is no decision yet as the routing protocol for FANET. In this paper, we propose the OLSR-Pds (Prediction with direction and speed) which is added a method to predict status of link for OLSR protocol. The mobility of nodes are modeled using Gauss-Markov algorithm, and relative speed between nodes were calculated by derive equation of movement, and thereby we can predict link status. An experiment for comparing AODV, OLSR and, OLSR-Pds was conducted by three factors such as packet delivery ratio, end to end delay, and routing overhead. In experiment result, we were confirm that OLSR-Pds performance are superior in these three factors. OLSR-Pds has the disadvantage that requires time-consuming calculations for link state and required for computing resources, but we were confirm that OLSR-Pds is suitable for routing to the FANET environment because it has all the characteristics of proactive protocol and reactive protocol.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.5
• /
• pp.1075-1082
• /
• 1997

In this paper, we propose a channel assignment scheme for reducing call blocking rate in a base station(BS) of DS-CDMA cellular systems. The proposed scheme can e applied to the case where the capacity of reverse radio link is enough, but not are the available traffic channels performing the digital modulation and demodulation functions between a mobile station and the base station. The proposed scheme takes advantage of the feature of soft handoff in which a mobile station keeps its communication link even if one of the two communication links is released. The scheme estimates the mean and variance of the received power level measured at the base station before assigning a traffic channel for a new call request. The BS makes decision based on the estimated balues whether the new call request will be accepted or not. If it is decided that the capacity of reverse radio link is enough, but all traffic channels are not available, then the BS increases the soft handoff parameter T_DROP to release the traffic channels of mobile stations loactedin soft handoff area. The BS assigns the released traffic channel to anew call or a handoff call. The performance of the proposed channel assignment scheme is evaluated by computer simulation. The results show that the call blocking rate for new calls and handoff calls is reduced.

• Korean Management Science Review
• /
• v.19 no.2
• /
• pp.221-235
• /
• 2002

Many people are getting more and more interested in the value of information sharing in a supply chain in proportion to the development of information technology in these days. In spite of much interest in the value of shared information, the related studies concluded that the effect of only sharing information strategy between upper and lower level is not large However, many related companies want to link each channel members in the supply chain with on-line to expect to reduce the cost by means of information sharing. This study wants to evaluate the alternative strategy to reduce more related costs than only sharing information strategy. This paper analyzed that how much the total supply chain cost is to change in the case of a transfer of decision rights from the lower (retailers) to the upper level (depot, vendor) in a supply chain. The decision rights mean the rights of being able to decide when to order, how much to order, where to order, and what mode to transport or distribute, etc. in a supply chain. By the experimental simulation study to the simple case, the strategy to share only information took the low effect of 1～2%, but the strategy to transfer the decision lights from the lower to the upper member had larger effect of about 5%. However. for the strategies to work well, it needs to cooperate closely among each supply chain members, and the fruits from the transfer of decision rights in a supply chain are allocated to each chain members reasonably Therefore, there needs to study in the future not only the exact transfer effect of decision rights, but the reasonable allocation method of the fruits among the chain members.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.10
• /
• pp.2620-2631
• /
• 2012

In this paper, a rerouting-controlled ISL (Inter-Satellite link) handover protocol for LEO satellite networks (RCIHP) is proposed. Through topological dynamics and periodic characterization of LEO satellite constellation, the protocol firstly derives the ISL related information such as the moments of ISL handovers and the intervals during which ISLs are closed and cannot be used to forward packet. The information, combined with satellite link load status, is then been utilized during packet forwarding process. The protocol makes a forwarding decision on a per packet basis and only routes packets to living and non-congested satellite links. Thus RCIHP avoids periodic rerouting that occurs in traditional routing protocols and makes it totally unnecessary. Simulation studies show that RCIHP has a good performance in terms of packet dropped possibility and end-to-end delay.

• Journal of Power Electronics
• /
• v.16 no.3
• /
• pp.1012-1024
• /
• 2016

This study deals with an on-line software fault detection, localization, and system reconfiguration method for electrical system drives composed of three-phase AC/DC/AC converters and three-phase permanent magnet synchronous machine (PMSM) drives. Current sensor failure (outage), speed/position sensor loss (disconnection), and damaged DC-link voltage sensor are considered faults. The occurrence of these faults in PMSM drive systems degrades system performance and affects the safety, maintenance, and service continuity of the electrical system drives. The proposed method is based on the monitoring signals of "abc" currents, DC-link voltage, and rotor speed/position using a measurement chain. The listed signals are analyzed and evaluated with the generated residuals and threshold values obtained from a Sliding Mode Current-Speed-DC-link Voltage Observer (SMCSVO) to acquire an on-line fault decision. The novelty of the method is the faults diagnosis algorithm that combines the use of SMCSVO and adaptive thresholds; thus, the number of false alarms is reduced, and the reliability and robustness of the fault detection system are guaranteed. Furthermore, the proposed algorithm's performance is experimentally analyzed and tested in real time using a dSPACE DS 1104 digital signal processor board.

• Journal of Convergence for Information Technology
• /
• v.11 no.11
• /
• pp.10-16
• /
• 2021

As the implementation of smart factories spreads widely, the need for research to improve data efficiency is raised by prioritizing massive amounts of big data using IoT devices in terms of relevance and quality. The purpose of this study is to investigate whether prioritizing big data in management accounting decisions such as cost volatility estimation and recipe optimization can improve smart solution performance and decision-making effectiveness. Based on the survey answers of 84 decision makers at domestic small and medium-sized manufacturers who operate smart solutions such as ERP and MES that link manufacturing data in real time, empirical research was conducted. As a result, it was analyzed that setting prioritization of big data has a positive effect on decision-making in management accounting. became In addition, it was found that big data prioritization has a mediating effect that indirectly affects smart solution performance by using big data in management accounting decision making. Through the research results, it will be possible to contribute as a prior research to develop a scale to evaluate the correlation between big data in the process of business decision making.

• Journal of Communications and Networks
• /
• v.18 no.3
• /
• pp.311-319
• /
• 2016

In this paper, we analyze the spectrum-sensing performance of a cooperative cognitive radio (CR) network consisting of a number of CR nodes and a fusion center (FC). We introduce the "log-average-SNR ratio" that relates the average SNR of the CR-node-FC link and that of the primary-user-CR-node link. Assuming that the FC utilizes the K-out-of-N rule as its decision rule, we derive exact expressions for the sensing gain and the coding gain - parameters used to characterize the CR network performance at the high SNR region. Based on these results, we determine ways to optimize the performance of the CR network.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.13 no.2
• /
• pp.13-25
• /
• 2017

Recently, the high performance of tactical situation display console and tactical data links are used to integrate the operational situations in accordance with information age and NCW (Network Centric Warfare). The tendency to maximize the efficiency of task execution has been developed by sharing information and the state of the battle quickly through complex and diverse information exchange. Tactical data link is a communication system that shares the platform with core components of weapons systems and battlefield situation between the command and control systems to perform a Network Centric Warfare and provides a wide range of tactical data required for decision-making and implementation.It provides the tactical information such as tactical information such as operational information, the identification of the peer, and the target location in real time or near real time in the battlefield situation, and it is operated for the exchange of mass tactical information between the intellectuals by providing common situation recognition and cooperation with joint operations. In this study, still image management, audio file management, tactical screen recording and playback using the storage and playback, NITF (National Imagery Transmission Format) message received from the displayer integrates the tactical situation in three dimensions according to multiple data link operation to suggest ways to ensure data integrity between the data link processor during the entire operation time.