• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.918-925
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• 2017

This paper presents a path planning problem for multi-robot system in the environment with dynamic obstacles. In order to guide the robots move along a collision-free path efficiently and reach the goal position quickly, a navigation method based on fuzzy logic controllers has been developed by using proximity sensors. There are two kinds of fuzzy controllers developed in this work, one is used for obstacle avoidance and the other is used for orientation to the target. Both static and dynamic obstacles are included in the environment and the dynamic obstacles are defined with no type of restriction of direction and velocity. Here, the environment is unknown for all the robots and the robots should detect the surrounding information only by the sensors installed on their bodies. The simulation results show that the proposed method has a positive effectiveness for the path planning problem.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.32-38
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• 1999

An autonomous mobile vehicle for transport system must plan optimal path in work envimnrent without human supervision and obstacle collision. This is to reach a destination without getting lost. In this paper, a genetic algorithm for globaI and local path planning and collision avoidance is proposed. The genetic algorithm searches for a path in the entire and continuous free space and unifies global path planning and local path planning. The sinmulation shows the proposed method is an efficient and effective method when compared with the traditional collision avoidance algorithms.rithms.

• Journal of Electrical Engineering and information Science
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• v.2 no.3
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• pp.51-60
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• 1997

A practically applicable collision free trajectory planning technique for tow robot systems is proposed. The robot trajectories considered in this work are composed of many segments, an at the intersection points between segments robots stop to assemble, weld, ordo other jobs by the attached a end-effectors. The proposed method is based on the Planning-Coordination Decomposition where planning is to find a trajectory of each robot independently according to their tasks and coordination is to find a velocity modification profile to avoid collision with each other. To fully utilize the independently planned trajectories and to ensure no geometrical path deviation after coordination, we develop a simple technique added the minimal delay time to avoid collision just before moving along path segments. We determine the least delay time by the graphical method in the Coordination space where collisions and coordinations are easily visualized. We classify all possible cases into 3 group and derive the optimal solution for each group.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.164-164
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• 1999

An autonomous mobile vehicle for transport system must plan optimal path in work environment without human supervision and obstacle collision. This is to reach a destination without getting lost. In this paper, a genetic algorithm for global and local path planning and collision avoidance is proposed. The genetic algorithm searches for a path in the entire and continuous free space and unifies global path planning and local path planning. The simulation shows the proposed method is an efficient and effective method when compared with the traditional collision avoidance algorithms.

• Journal of the military operations research society of Korea
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• v.16 no.2
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• pp.151-167
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• 1990

Considerable research has concentrated on medium-range production planning model in that it can contain long and short-term decision making in contents. Since medium-range production planning deals in situations with setup time or/and costs, solution methodology is classified by (1) optimization method using a sort of integer programming approach and network formulation (2) heuristic method offering an computationally easy, approximate solution. But, solution methodology is different in type of demand generation, existence of capacity and dependant demand. Therefore this paper reviewed the medium range production planning according to above mentioned three factors, and suggested for further work direction.

• Journal of Construction Engineering and Project Management
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• v.2 no.3
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• pp.40-47
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• 2012

Construction management is essential for a achieving any pre-determined objective. It is however seen that in spite of construction management, majority of the project do not keep up their original time schedule and their completion cost is also higher as compared with the estimated cost The main reason for overrun in time and cost is that the planning at the outset of the project was not adequate or method of planning was not a refined one. In this research work, I showed the overall conditions of construction work and management in Sylhet city of Bangladesh and found many drawbacks in the construction management after completing my research. I found several factors affecting proper construction management and I have provided brief results. I have also provided some recommendations after my research work.

• Journal of Fashion Business
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• v.19 no.4
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• pp.183-199
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• 2015

This study aimed to systematize the apparel vendor work processes and provide useful information to future employees of clothing export units by analyzing the processes of vendors' manufacturing tasks. A survey of 20 apparel vendors servicing mainly U.S. buyers was conducted on employees of overseas business departments working for more than five years. buyers. Based on the results, vendors mainly manufactured cut-and-sew knit products. Regarding the production method, OEM was used more frequently than ODM. Fourteen (70%) companies used the ODM method. This suggests that vendors are expanding their production method from OEM to ODM. In order to summarize the work of each business based on the clothing production process research results, buyers were in charge of planning products and the vendors were in charge of sampling. Production of materials and the approval of material tests were out sourced. Overseas factories of vendors were in charge of bulk (mass) production and garment finishing, as well as packaging and shipping the completed products. Even though the vendors' head offices do not directly produce clothes, they play a pivotal role in ensuring planning and management progress in clothing production. As buyers prefer direct contracts for cost reduction, the vendor additionally performs the role of an agent. Also, with the increase in ODM production ratio, the work area of the vendor is expanding. If Korean clothing exporters improve their global competitiveness by investing in the R&D of materials and design to enhance the ODM method, the development of Korea's clothing and export industry will benefit significantly.

• Korean Journal of Construction Engineering and Management
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• v.23 no.4
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• pp.65-77
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• 2022

Schedule management is one of pivotal project success factors during construction projects. However, there are many difficulties in rapid scheduling and controlling since the existing planning techniques require considerable amount of manual work and manager's judgment in a construction project. This research aims to propose a new scheduling method and algorithm for automating and visualizing the planning process, which is called Countable-grid scheduling method. In this method, if the scope of work is defined via a visualized tool, the schedule plan is created automatically according to the productivity and workable conditions of each activity. The location of the work for each date can be visualized in grid-based approach. Moreover, the work schedule can be updated automatically according to the progress. The industrial applicability of the proposed method was verified in construction projects via case study with sample data. This research can contribute to the construction industry by automating the construction schedule management process.

• Korean Journal of Construction Engineering and Management
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• v.6 no.6 s.28
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• pp.90-97
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• 2005

Poor usage of work-continuity for planning and management is one of the leading causes of decreased productivity in high-rise and complexity construction projects. For efficient finish work, tact scheduling method needs to be implemented according to tact time. But there are the studies about zoning of work area, daily construction information and tact planning and management, there are not the studies about tact time yet. The purpose of this study is to help implementation of tact scheduling by tact time and adjusted work-plan. The main contents of this study are as follow; (1)Tact time has been calculated as coordination of work-plan between a general contractor and specialties. (2)Project-plan can be without delay by tact time calculation method.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.709-712
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• 1996

Generating a project network of a specific construction project is very time consuming and difficult task in the field. To effectiviely automate and support the planning process, we design a case-based project planning expert system inspired by the fact a human expert project planner uses previous cases for planning a new project. A construction project case consist of its specific characteristics and the corresponding project network (i.e. project plan). Using frame based representation. we represent the project features affecting the progress network and the entities composing the project plan such as the buildings, construction methods, WBS (work breakdown structure), activities, and resources. The project planning process runs through most similar case retrieval, case adaptation, and user requirement satisfaction. We represent the construction domain knowledge for each procedure using constraints and rules. We develop the methodology for constraint-based case adaption. Case adaptation process mainly consist of activity generation/deletion and predecence constraint satisfaction, for which we develop the dynamic constraint generation method and connect user-level requirement representation the system-level network modification knowledge. The methodology is being applied to the prototype for apartment construction project planning.