• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.305-314
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• 2017

Most of the existing researches on systemwide optimization of generator maintenance scheduling do not consider the equivalent operating hours(EOHs) mainly due to the difficulties of calculating the EOHs of the CCGTs in the large scale system. In order to estimate the EOHs not only the operating hours but also the number of start-up/shutdown during the planning period should be estimated, which requires the mathematical model to incorporate the economic dispatch model and unit commitment model. The model is inherently modelled as a large scale mixed-integer nonlinear programming problem and the computation time increases exponentially and intractable as the system size grows. To make the problem tractable, this paper proposes an EOH calculation based on demand grouping by K-means clustering algorithm. Network congestion is also considered in order to improve the accuracy of EOH calculation. This proposed method is applied to the actual Korean electricity market and compared to other existing methods.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.193-200
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• 1995

A shop floor control system(SFCS), a central part of agile manufacturing, performs the production activities required to fill orders. In order to effectively control these activities, CSCW (computer supported cooperative work) is adopted where a supervisor does not exist. In this paper, we define functional perspective of CSCW-based shop floor control using planning, scheduling, and execution functions. In particular, we focus on an execution model that can coordinate the planning and scheduling functions. Execution can be defined informally as a function that downloads and performs a set of scheduled tasks. Execution is also responsible for identifying and resolving various errors whether they come from hardware or software. The purpose of this research is to identify all the execution activities and solving techniques under the assumptions of CSCW-based heterarchical control architecture. This paper also proposes a classification scheme for execution activities of CSCW-based heterarchical control architecture. Petri-nets are used as a unified framework for modeling and controlling execution activities. For solving the nonexistence of a supervisor, A negotiation-based solution technique is utilized.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.96-100
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• 2004

In the ship building industry various problems of erection is counterfeited due to formation of bottle necks in the block erection flow pattern This kind of problems cause accumulated problems in real-time erection right on the floor, When such a problem is approached, a support data of the entire erection sequence should be available, Here planning is done by reasoning about the future events in order to verify the existence of a reasonable series of actions to accomplish a goal. This technique helps in achieving benefits like handling search complications, in resolving goal conflicts and anticipation of bottleneck formation well in advance to take necessary countermeasures and boosts the decision support system, The data is being evaluated and an anticipatory function is to be developed This function is quite relevant in day to day planning operation. The system updates database with rearrangement of off-critical blocks in the erection sequence diagram, As a result of such a system, planners can foresee months ahead and can effectively make decisions regarding the control of loads on the man, machine and work flow pattern, culminating to an efficient load management. Such a foreseeing concept helps us in eliminating backtracking related adjustment which is less efficient compared to the look-ahead concept. An attempt is made to develop a computer program to update the database of block arrangement pattern based on heuristic formulation.

• International Journal of Computer Science & Network Security
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• v.23 no.9
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• pp.65-70
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• 2023

The "information roadway" will give us an impact of new PC based assignments and administrations, yet the unusualness of this new condition will ask for another style of human-PC association, where the PC transforms into a sharp, dynamic and customized partner. Interface administrators are PC programs that use Artificial Intelligence frameworks to give dynamic help to a customer with PC based errands. Operators drastically change the present client encounter, through the similitude that a specialist can go about as an individual collaborator. The operator procures its capability by gaining from the client and from specialists helping different clients. A couple of model administrators have been gathered using this methodology, including authorities that give customized help with meeting planning, electronic mail taking care of, Smart Personal Assistant and choice of diversion. Operators help clients in a scope of various ways: they perform assignments for the client's sake; they can prepare or educate the client, they enable diverse clients to work together and they screen occasions and methods.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.201-204
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• 1997

This study is focussed on optimization problems which require allocating the restricted inventory to demand points and assignment of vehicles to routes in order to deliver goods for demand sites with optimal decision. This study investigated an integrated model using three step-by-step approach based on relationship that exists between the inventory allocation and vehicle routing with restricted amount of inventory and transportations. we developed several sub-models such as; first, an inventory-allocation model, second a vehicle-routing model based on clustering and a heuristic algorithms, and last a vehicle routing scheduling model, a TSP-solver, based on genetic algorithm. Also, for each sub-models we have developed computer programs and by a sample run it was known that the proposed model to be a very acceptable model for the inventory-allocation and vehicle routing problems.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.255-264
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• 2021

In this paper, we propose operations and maintenance (O&M) planning approach for floating offshore wind farm using the mathematical optimization. To be specific, we present a MILP (Mixed Integer Linear Programming that suggests the composition of vessels, technicians, and maintenance works on a weekly basis. We reflect accessibility to wind turbines based on weather data and loss of power generation using the Jensen wake model to identify downtime cost that vary from time to time. This paper also includes a description of two-stage approach for maintenance planning & detailed scheduling and numeric analysis of the number of vessels and technicians on the O&M cost. Finally, the MILP model could be utilized in order to establish the suitable and effective maintenance planning reflecting domestic situation.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1991.10a
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• pp.67-76
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• 1991

For several years, graduate students and faculty of the Engineering Systems Research Center at U.C., Berkeley have been studying new methods of planning and scheduling in a computer integrated manufacturing environment, with particular emphasis on large scale integrated circuit fabrication. One part of this work, focusing on short interval scheduling, uses simulation models as a primary research tool. We have built two versions of the same basic model (programmed in C) to study two different problems (one deals with machine down time and the other with setup times). These have proven to be efficient for studying particular problems, but are difficult and time consuming to modify. We are convinced that our research will be more effective: (1) if it were easier to build special purpose models tailored to the research question at hand; and (2) if we had better interfaces to graphics output. Commercially available factory simulators are inadequate for this research for a variety of reasons. Existing packages such as SIMKIT, SLAM, SIMAN and EXCELL have their own weaknesses. Typically, they are hard to develop and to modify. They do not allow for adding new dispatching decisions or release decision. Also, it is hard to add more machines to existing environment or change the route the product flows. For these various reasons, we had developed a new simulation package having flexibility and modularity. In this paper, based on experiences gained in the application of object oriented programming, we discuss unique features of the simulator developed in OOPS and ways to take advantage of features in developing and using manufacturing simulation software written in the OOPS

• Journal of Intelligence and Information Systems
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• v.7 no.1
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• pp.1-15
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• 2001

Recently, Internet based Electronic Commerce is recognized as one of the alternatives for strengthening sales power of small and medium companies. However, small and medium manufacturers can't adjust properly to the new environment because they are in short of money, personnel, and technology. To cope with this problem, this paper deals with the development of virtual manufacturing agent to support sales agent. The sales activity of most of parts manufacturing companies is based on orders of buyers. The process of promotion, receipt and selection of orders of the parts manufacturing is closely coupled with the load status of the production lines. On deciding whether to accept an order or not, as well as negotiating with buyers, sales person needs information such as load and schedule of production lines, manufacturability of the order. Therefore, the functions of virtual manufacturing agents manufacturability analysis, process planning, and scheduling are key features in developing an agent of sales activity for the parts manufacturing business. While most of research on virtual manufacturing system so far is focused on the simulation of each product, this paper deals with the development of agent assisting internet-based product sales by supporting production information promptly. The pilot system of virtual manufacturing agent is implemented using KQML-based agent template and Java-based expert system shell for a small molding company.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.176-184
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• 2023

Points of interest (POIs) are widely used in tourism recommendations and to provide information about areas of interest. Currently, situation judgement using POI and GPS data is mainly rule-based. However, this approach has the limitation that inferences can only be made using predefined POI information. In this study, we propose an algorithm that uses POI data, GPS data, and schedule information to calculate the current speed, location, schedule matching, movement trajectory, and POI coverage, and uses machine learning to determine whether to stay or go. Based on the input data, the clustered information is labelled by k-means algorithm as unsupervised learning. This result is trained as the input vector of the SVM model to calculate the probability of moving and staying. Therefore, in this study, we implemented an algorithm that can adjust the schedule using the travel schedule, POI data, and GPS information. The results show that the algorithm does not rely on predefined information, but can make judgements using GPS data and POI data in real time, which is more flexible and reliable than traditional rule-based approaches. Therefore, this study can optimize tourism scheduling. Therefore, the stay detection algorithm using GPS movement trajectories and POIs developed in this study provides important information for tourism schedule planning and is expected to provide much value for tourism services.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.373-378
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• 2006

Recently the technical advances and complexities have generated much of the difficulties in managing the project resources, for both scheduling and costing to accomplish the project in the most efficient manner. The project manager is frequently required to render judgments concerning the schedule and resource adjustments. This research develops an analytical model for a schedule-cost and risk analysis based on visual PERT/CPM. We used a three-step approach: 1) in the first step, a deterministic PERT/CPM model for the critical path and estimating the project time schedule and related resource planning and we developed a heuristic model for crash and stretch out analysis based upon a time-cost trade-off associated with the crash and stretch out of the project. 2) In second step, we developed web-based risk evaluation model for project analysis. Major technologies used for this step are AHP (analytic hierarchy process, fuzzy-AHP, multi-attribute analysis, stochastic network simulation, and web based decision support system. Also we have developed computer programs and have shown the results of sample runs for an R&D project risk analysis. 3) We developed an optimization model for project resource allocation. We used AHP weighted values and optimization methods. Computer implementation for this model is provided based on GUI-Type objective-oriented programming for the users and provided displays of all the inputs and outputs in the form of GUI-Type. The results of this research will provide the project managers with efficient management tools.