• Journal of Korean Society for Quality Management
• /
• v.18 no.2
• /
• pp.18-24
• /
• 1990

The location of inspection stations is a significant component of production systems. In this paper, a prototype expert system is designed for deciding the optimal location of inspection stations. The production system is defined as a single channel of n serial operation stations. The potential inspection station can be located after any of the operation stations. Nonconforming units are generated from a compound binomial distribution with known parameters at any given operation station. Traditionally Dynamic programming, Zero-one integer programming, or Non-linear programming techniques are used to solve this problem. However a problem with these techniques is that the computation time becomes prohibitively large when t be number of potential inspection stations are fifteen or more. An expert system has the potential to solve this problem using a rule-based system to determine the near optimal location of inspection stations. This prototype expert system is divided into a static database, a dynamic database and a knowledge base. Based on defined production systems, the sophisticated rules are generated by the simulator as a part of the knowledge base. A generate-and-test inference mechanism is utilized to search the solution space by applying appropriate symbolic and quantitative rules based on input data. The goal of the system is to determine the location of inspection stations while minimizing total cost.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.5
• /
• pp.1951-1972
• /
• 2018

Wi-Fi Access Point (AP) optimization approaches are used in indoor positioning systems for signal coverage enhancement, as well as positioning precision improvement. Although the huge power consumption of the AP optimization forms a serious problem due to the signal coverage requirement for large-scale indoor environment, the conventional approaches treat the problem of power consumption independent from the design of indoor positioning systems. This paper proposes a new Fast Water-filling algorithm Group Power Constraint (FWA-GPC) based Wi-Fi AP optimization approach for indoor positioning in which the power consumed by the AP optimization is significantly considered. This paper has three contributions. First, it is not restricted to conventional concept of one AP for one candidate AP location, but considered spare APs once the active APs break off. Second, it utilizes the concept of water-filling model from adaptive channel power allocation to calculate the number of APs for each candidate AP location by maximizing the location fingerprint discrimination. Third, it uses a fast version, namely Fast Water-filling algorithm, to search for the optimal solution efficiently. The experimental results conducted in two typical indoor Wi-Fi environments prove that the proposed FWA-GPC performs better than the conventional AP optimization approaches.

• Journal of Korean Society of Transportation
• /
• v.29 no.2
• /
• pp.91-100
• /
• 2011

Hub network design for freight transportation is a decision process that determines hub locations together with freight transportation routes among shippers so as to ultimately minimize total logistics cost. This study presents the optimal location of hubs by strict hub network design policy with single allocation, which overcomes the limitation of Kim et al. (2008) that does not allow direct transportation among shippers. The greedy-interchange algorithm is employed for hub location decision process, and EMME/2 is adopted for the route searching process. Application of the processes to the nationwide highway network shows that the best hub locations in order are Seoul metropolitan, GyeongNam, Chung-nam, Jeon-Nam, Gyeong-Buk, Chung-Buk, and the locations are concentrated on the Seoul-Busan corridor. The strict hubnetwork design policy with single allocation increases the transportation distance but decreases the transportation cost by passing through the hubs instead of direct transportation. The reduction in total transportation cost can be achieved as the number of hubs increases, but the amount of the reduction gradually decreases because the cost reduction from the decrease in detour transportation distance between non-hubs and hubs becomes less than the discount reduction from dispersion of inter-hubs transportation volumes.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.2
• /
• pp.443-449
• /
• 2015

In this paper, we proposed Channel allocation scheme according to the user's location with IR. In VLC System, LED can generate various colors of light by controlling the mixing ratio of each individual RGB color element. Thus, each RGB channel will have a different signal power, and each channel will have different performance. This proposed system using Visible light(RGB) as way to transmit signals, it depends on the mixture RGB, which decided the color of light, moreover, each things determined their performance. However, if the signal were fixed allocated RGB to transmit such as the original system, the importance of the each signals a different occur the limit on the quality of signals. To solve this problem in this paper, according to the RGB mixture ratios analyze the performance for the LED, which analyzed based on allocating the signal by transmitting to improve the quality was about how researched. In addition, our proposed system is able to improve the performance of BER and satisfied the Qos to desire users.

• Science of Emotion and Sensibility
• /
• v.23 no.4
• /
• pp.3-20
• /
• 2020

The purpose of this study was to investigate the effect of aging on visuo-spatial attention allocation ability and emotional perception bias. We used the useful field of view (UFOV) task to measure the visuo-spatial attention allocation ability and the emotional perception task to measure positive and negative emotional perception bias. A total of 48 participants took part in this study with 23 participants in the senior group and 25 in the junior group. The senior group showed slower response time and lower accuracy than the junior group in the UFOV task, indicating that the senior group had lower visuo-spatial attention allocation ability than the junior group. In the emotional perception task, the senior group showed both positive and negative emotional perception bias more than the junior group. The correlation analysis showed that the negative emotional perception bias for accuracy in the emotional perception task showed a positive correlation with the response time to the stimuli presented in the visual angle 30° in the UFOV task (r=.289). In addition, positive emotional perception bias for the accuracy in the emotional perception task showed a positive correlation with the accuracy of the stimuli presented in the visual angles 10°, 20°, and 30° in the UFOV task (r=.305, r=.322, and r=.299, respectively). However, it showed a negative correlation with the response time of the stimuli presented in the same location in the UFOV task (r=-.345, r=-.295, r=-.308). These results suggest that aging is associated with a decrease in the visuo-spatial attention allocation ability and perceptual bias toward positive and negative emotions. In addition, the positive and negative emotional perception biases associated with aging are potentially related to the reduced visuo-spatial attention allocation ability.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.1
• /
• pp.43-50
• /
• 2013

This paper aims to determine the optimal location of expressway patrol vehicle stations that minimizes additional troubles caused by the delay of crash treatments. To do this, we formulate a maximum covering problem and a p-center problem weighted by crash frequency, using the shortest distance as the criteria for allocating service district, and we employ the Lagrangian relaxation algorithm to solve the former and Daskin's heuristic algorithm to solve the latter, respectively. Based on crash data of Korean expressways, the results from the proposed models are compared with the current location of patrol vehicle stations by using several indices as the level of service for crash treatment, such as maximum crash-weighted distance, average crash-weighted distance, and average access distance. The results show that the proposed models improve average access distance and time by about 10km and 10min, respectively. When allocation for service district is changed only with the fixed current location, the level of service can be also improved. The models and results proposed in this paper can contribute to improving the level of service for crash treatment on expressways. They can also provide the theoretical basis on the location decision for other various emergency facilities, and the allocation decision for floating service districts according to time-period crash data.

• Proceedings of the KIEE Conference
• /
• 1999.07c
• /
• pp.1026-1028
• /
• 1999

In recent deregulation and competitive power market environment, electric utilities plan and operate their systems for economic benefit with secure system condition. Therefore, implementation of Flexible AC Transmission Systems (FACTS) devices can be planned for the efficient utilization of the present system facility. This paper presents a technique to solve the problem about optimal allocation of FACTS devices far the purpose of enhanced system operation.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.31 no.3
• /
• pp.11-25
• /
• 2006

Space may be a scarce resource in manufacturing shops, warehouses, freight terminals, and container terminals. This Paper discusses how to locate temporary storage Inventories In limited storage areas. A typical inventory is delivered from the location of the preceding process to the storage area and stored In the storage area during the certain period of time. And it may be relocated from the storage position to another. Finally. it is delivered from the final storage area to the location of the next process. Because this logistic process for an inventory requires handling activities, transportation activities, and storage spaces, the limitation in capacities of handling equipment, transportation equipment, and storage space must be considered when allocating spaces to the inventory. This problem Is modeled as a multicommodity minimal cost flow problem. And a heuristic algorithm for the Problem is proposed. Numerical experiments are presented to validate the mathematical model and the heuristic algorithm.

• Journal of Korean Institute of Industrial Engineers
• /
• v.34 no.2
• /
• pp.205-215
• /
• 2008

convergence networks (BcN). The problem seeks to minimize the total cost of switch and cable while satisfying the requirement of demand and quality of service (QoS). We develop mixed integer programming models to obtain the optimal switch location of the access network. We develop a Tabu Search (TS) heuristic algorithm for finding a good feasible solution within a reasonable time limit. We propose real networks with up to 25 nodes and 180 demands. In order to demonstrate the effectiveness of the proposed algorithm, we generate lower bounds from nonlinear QoS relaxation problem. Computational results show that the proposed heuristic algorithm provides upper bounds within 5% optimality gap in 10 seconds.

• Journal of the Korean Data and Information Science Society
• /
• v.20 no.5
• /
• pp.919-924
• /
• 2009

Geographical location carries information such as demography, local economy, environment, and life styles, which could be the sources of cancer occurrence. Analyzing geographical location associated with cancer occurrence can be instructive to physicians, patients, and health administrators regarding resource allocation, expenditures, prophylaxis and treatments. In this paper, we explored the correspondence relationship between geographical locations and mortality rates of the cancers using correspondence analysis and illustrated the approach with the mortality rates of the top 10 cancers in the 75 counties in Arkansas from 2001 to 2005. Geographical variations with respect to the mortality rates of cancers are evaluated across Arkansas counties. Based on the contingency table, correspondence analysis model is developed and the simple indices which indicate the degree to which the regions and the cancers affect each other are calculated. Quantitative results are visualized and mapped in two-dimensional graphs.