• International Journal of Highway Engineering
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• v.14 no.5
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• pp.157-164
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• 2012

PURPOSES: Regional offices of the Ministry of Land, Transport and Maritime Affairs use a computerized system called KAMIS so as to manage road equipment systematically. Road agencies can record number of operating days by equipment, actual working hours, accumulated operating hours (or distance) by equipment, and operating cost. However, KAMIS does not provide critical information, although it is strongly related to efficient road management equipment operation. In other words, road agencies do not know whether they have sufficient equipment to handle their actual work. METHODS: Therefore, this study suggests a methodology to evaluate for operational efficiency of road management equipment using analytical hierarchy process(AHP). First of all, estimated weights related criteria can be produced by AHP, and then use operational history by pieces of equipment. RESULTS: Results show that importance of management work can differ from weather conditions through five areas. CONCLUSIONS: Commonly, this results can imply to help save money for the purchase and maintenance of road management equipment, and they would improve the functional performance of KAMIS.

• Korean journal of food and cookery science
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• v.11 no.3
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• pp.295-302
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• 1995

The purposes of the study were to identify the operational characteristics in employee feeding facilities, and to examine the correlations of productivity and these characteristics. A questionnaire was developed and mailed the 500 dietitians in employee feeding facilities in Seoul and Kyoungki Do. Usable questionnaires were received from 117 respondents for a response rate of 23.4％. The questionnaire was designed to determine the productivity index and to investigate the relationship between operational characteristics and productivity index. The questionnaire was contained 2 parts with a total of 16 statements. Data were analyzed for descriptive statistics and Pearson correlation analysis using SPSS/PC programs. The average productivity indices of 117 facilities were 6.91 meals/hr. Total meals served/week was significantly correlated to the productivity index (r=0.441, p < 0.001). No of average servings per meal, percentage of convenience food use, average minutes for service/day, and employment in professional practice of dietitian were also positively correlated, while food cost was negatively correlated to the productivity.

• Electronics and Telecommunications Trends
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• v.39 no.4
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• pp.32-41
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• 2024

Building energy management plays a crucial role in improving energy efficiency and optimizing energy usage. To achieve this, it is important to monitor and analyze energy-related data from buildings in real time using sensors to understand energy consumption patterns and establish optimal operational strategies. Because of the uncertainties in building energy-related data, there are challenges in analyzing these data and formulating operational strategies based on them. Artificial intelligence (AI) technology can help overcome these challenges. This paper investigates past and current research trends in AI technology and examines its future prospects for building energy management. By performing prediction and analysis based on energy consumption or supply data, the future energy demands of buildings can be forecasted and energy consumption can be optimized. Additionally, data related to the surrounding environment, occupancy, and other building energy-related factors can be collected and analyzed using sensors to establish operational strategies aimed at further reducing energy consumption and increasing efficiency. These technologies will contribute to cost savings and help minimize environmental impacts for building owners and operators, ultimately facilitating sustainable building operations.

• Journal of Korean Society of Forest Science
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• v.106 no.3
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• pp.300-309
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• 2017

The productivity, cost, and optimal forest road network density for tree-length yarding with K301-4 and HAM300 tower yarders were analyzed. The results showed that productivity decreased as the yarding distance increased. The productivity of the K301-4 was greater than that of the HAM300 as the maximum yarding distance was longer than 34 m. This difference increased as the load volume increased. As the K301-4 yarder had a higher purchase price and it took more time to set up compared to the HAM300, the HAM300 was cost effective. Therefore, in oder to introduce tower yarders to reduce operational cost, it is effective to increase the load volume during operations and to utilize the road network repeatedly for a long period.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.529-537
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• 2017

Membrane filtration process is an advanced water treatment technology that has excellently removes turbidity and microorganisms. However, it is known that it has problems such as low economic efficiency and the operating stability. Therefore, this study was to evaluate on the economical feasibility and operational stability comparison of membrane and sand filtration process in Im-sil drinking water treatment plant. For the economic analysis of each process, the electricity cost and chemical consumption were compared. In the case of electric power consumption, electricity cost is $68.67KRW/m^3$ for sand filtration and $79.98KRW/m^3$ for membrane filtration, respectively. Therefore, membrane filtration process was about 16% higher than sand filtration process of electricity cost. While, the coagulant usage in the membrane filtration process was 43% lower than the sand filtration process. Thus, comparing the operation costs of the two processes, there is no significant difference in the operating cost of the membrane filtration process and the sand filtration process as $85.94KRW/m^3$ and $79.71KRW/m^3$ respectively (the sum of electricity and chemical cost). As a result of operating the membrane filtration process for 3 years including the winter season and the high turbidity period, the filtrated water turbidity was stable to less than 0.025 NTU irrespective of changes in the turbidity of raw water. And the CIP(Clean In Place) cycle turned out to be more than 1 year. Based on the results of this study, the membrane filtration process showed high performance of water quality, and it was also determined to have the economics and operation stability.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1694-1714
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• 2007

This study is to estimate economic benefits of Standardization R&D of Urban Rail System. Benefit was to be realized through standardization of main areas such as train vehicle, railway, power system, and signal system. To derive and calculate the quantitative benefit, the sources of economic impact was divided into three dimensions -operational cost savings, import substitution, and safety effects. Economic effect of the standardization was categorized based on a modified BSC model. Economic benefits from time and labor savings are converted into cost savings. Import substitution and investment multiplier effect have a positive impact in addition to cost savings. The estimation of the standardization R&D of Urban Rail System was conservatively estimated 370 billion Won. Cost effectiveness of standardized safety system was conservatively translated into economic benefit in this analysis. This study provides a practical guide to economic evaluation of the various railway R&D projects.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.13 no.4
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• pp.324-335
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• 2013

This article presents the design, control, and implementation of a small quad-rotor system under the practical limitation of being cost effective for private use, such as in the cases of control education or hobbies involving radio-controlled systems. Several practical problems associated with implementing a small quad-rotor system had to be taken into account to satisfy this cost constraint. First, the size was reduced to attain better maneuverability. Second, the main control hardware was limited to an 8-bit processor such as an AVR to reduce cost. Third, the algorithms related to the control and sensing tasks were optimized to be within the computational capabilities of the available processor within one sampling time. A small quad-rotor system was ultimately implemented after satisfying all of the above practical limitations. Experimental studies were conducted to confirm the control performance and the operational abilities of the system.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.434-438
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• 2000

In this paper the low cost sensorless control circuit for a PM synchronous motor without the mechanical rotor position sensors is presented. The sensorless control algorithm and position detection circuit for the sinusoidal current wave drive is more complex than that of the rectangular current wave drive. The proposed position sensing circuit is composed of an operational amplifier and several passive elements. The design procedures for getting the optimal parameters for the position sensing circuit are presented. The performance of the proposed algorithm is verified through the simulations and experiments.

• Korean Management Science Review
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• v.10 no.2
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• pp.111-120
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• 1993

The most important factors for a product to survive in the market are cost and quality. In recent years, quality proceeds to cost. There are many techniques of use to improve the quality of a product. One of the techniques is applying statistical methods (especially Taguchi method) to real operational conditions for a continuous manufacturing process in P company. There are 91 factors to control in the process. So, we predetermined 7 main effect factors and 6 interactive effect factors by statistical methods and advices of engineers. With these 13 factors, we determined the optimal level of operations for the process.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.347-349
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• 2000

Under an open transmission access, the generation dispatch is determined by the bidding process of market participants. Congestion occurs when the dispatch would result in the violation of operational constraints. Congestion problem is formulated and solved by OPF(optimal power flow) calculation. The objective functions in OPF are given as quadratic cost functions or piecewise linear functions of bidding functions. In this study, the optimization technique of generation dispatch is presented for the combination of two types of quadratic and linear cost functions.