• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.279-285
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• 2021

The materials, parts, and equipment industries are the backbone of the manufacturing industry and a key element of competitiveness. However, in the case of Korea, as it relies on foreign countries for core materials, parts, and equipment, it is in danger of not only industrial competitiveness, but also security. This study first looked at the outline and current address of the materials, parts, and equipment industries, identified problems and improvements, and examined the efforts and achievements so far for the localization of materials, parts, and equipment in Korea. In addition, after looking at the improvement measures for the government's material, parts, and equipment industry at the institutional level or at the ecological level, the current status and actual condition of localization of local materials, parts and equipment were investigated, and problems and improvements were analyzed. Lastly, this study presented a technology development plan for localization of parts and materials in the region and various institutional improvement plans related to commercialization.

• Industrial Engineering and Management Systems
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• v.10 no.2
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• pp.161-169
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• 2011

In seeking further efficiency in production preparation, it is common to examine assembly sequences using digital manufacturing. The assembly sequences affect the product evaluation, so it is necessary to test several assembly sequences before actual production. However, because selection and testing of assembly sequences depends on the operator's personal experience and intuition, only a small number of assembly sequences are actually tested. Nevertheless, there is a systematic method for generating assembly sequences using a contact-related figure. However, the larger the number of parts, the larger the number of assembly sequences geometric becomes. The purpose of this study is to establish a systematic method of generating efficient assembly sequences regardless of the number of parts. To generate such assembly sequences selectively, a "Tournament Tree," which shows the structure of an assembly sequence, is formulated. Applying the method to assembly sequences of a water valve, good assembly sequences with the same structure as the Tournament Tree are identified. The structure of such a Tournament Tree tends to have fewer steps than the others. As a test, the structure is then applied for a drum cartridge with 38 parts. In all the assembly sequences generated from the contact-related figures, the best assembly sequence is generated by using the Tournament Tree.

• IE interfaces
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• v.18 no.1
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• pp.73-81
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• 2005

Injection molding has been widely used in producing plastic parts in large quantities. However, its productivity mainly depends on the expertise and experience of skilled workers because of the difficulty and complexity to determine a robust injection molding condition which is not influenced by the minor operational variation of an injection molding machine and produces good parts continuously. This study analyzes the defect types of the parts and proposes a support system to assist users in determining the robust process condition. The support system calculates the start condition from the information of an injection mold, the injection molding machine, the resin used, and the part. Through the iterative step which updates the condition using the defect information of the part tested, users can obtain the initial condition which produces the part without any problem for the first time. The support system also assists users in obtaining the robust condition from the initial condition using the technique of experimental design. To prove the validity of the support system, this study implements it in the control panel of the injection molding machine.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.194-199
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• 2003

Developed m this research is a production information system for marie propellers. The paper deals with surface modeling and tool path generation modules of the system. Since the input point data may have some errors, the data is examined using the 2nd divided difference. The point data is interpolated to a $G^2$ chord-length spline surface with some end-conditions. The effects of the various end-conditions on the interpolated surface are discussed in the paper. The tool paths for blade, fillet, and boss of the propeller are generated. Some illustrative examples from an industry are presented.

• Journal of Powder Materials
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• v.27 no.3
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• pp.256-267
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• 2020

Metal additive manufacturing (AM) technologies are classified into two groups according to the consolidation mechanisms and densification degrees of the as-built parts. Densified parts are obtained via a single-step process such as powder bed fusion, directed energy deposition, and sheet lamination AM technologies. Conversely, green bodies are consolidated with the aid of binder phases in multi-step processes such as binder jetting and material extrusion AM. Green-body part shapes are sustained by binder phases, which are removed for the debinding process. Chemical and/or thermal debinding processes are usually devised to enhance debinding kinetics. The pathways to final densification of the green parts are sintering and/or molten metal infiltration. With respect to innovation types, the multi-step metal AM process allows conventional powder metallurgy manufacturing to be innovated continuously. Eliminating cost/time-consuming molds, enlarged 3D design freedom, and wide material selectivity create opportunities for the industrial adoption of multi-step AM technologies. In addition, knowledge of powders and powder metallurgy fuel advances of multi-step AM technologies. In the present study, multi-step AM technologies are briefly introduced from the viewpoint of the entire manufacturing lifecycle.

• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.66-71
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• 2009

This study proposes a new framework for designing disassembly methods. In recent years, environmental problems have become global issues. Recycling of used products or resources is recognized as a matter of significance since it may help reduce the risk of exhausting natural resources. Considering possible exhaustion of limited natural resources in the near future, reuse of products would gain more environmental significance. As yet, it relies hugely on manual disassembly, which labor cost places burden on the total recycling cost. The purpose of this study is to propose a methodology designing for manual disassembly works, and a creation method of a jig. By focusing on parts' connection and attachment relationship, parts are categorized in 5 categories (parent part, joint key part, attaching key part, child part, and independent part) according to the features that parts possess, and 3 kinds of connection relationships (parent part-joint key part connection, parent part-independent part connection and child part-child part connection) are clarified. Connection relationship and attachment relationship charts have also been created, and utilizing them, disassembly orders are settled, and a disassembly jig is devised. The proposed methodology is also applied to a real product and its work time is improved 42% form 31 to 13 seconds.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.82-88
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• 2011

A typical job sequencing problem is studied in this research to improve productivities in manufacturing companies. The problem consists of two-stage parts and assembly processes. Two parts are provided independently each other and then two sequential assembly processes are followed. A new heuristic is developed to solve the new type of sequencing problem. Initial solution is developed in the first stage and then the initial solution is improved in the second stage. In the first stage, a longer part manufacturing time for each job is selected between two, and then a sequence is determined by descending order of the times. This initial sequence is compared with Johnson's sequence obtained from 2-machine assembly times. Any mismatches are tried to switch as one possible alternative and completion time is calculated to determine whether to accept the new sequence or not to replace the current sequence. Searching process stops if no more improvement can be made.

• Journal of Drive and Control
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• v.19 no.1
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• pp.34-42
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• 2022

Hydrostatic transmission (HST) comprises rotary parts, shafts, valve plate, swashplate, and servo pistons. Ensuring structural stability of each part of an HST has a significant impact on product safety. In this study, the structural stability of HST in agricultural machinery and industrial vehicles was analyzed using ANSYS software. For conservative evaluation, high-pressure conditions (35.5 MPa and 2 MPa pilot pressure) were applied as load conditions. The number of grids used in the calculations ranged from 0.4 to 0.8 million depending on modeling requirements. Structural analysis was performed for essential parts and safety factor was analyzed. All major parts of HST had a safety factor of ≥ 1.5. Thus, they were judged to be structurally safe. This study provides important information for designing an HST system.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.41-42
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• 2007

본 논문은 연자성체(Iron powder)를 적용한 단상 BLDCM의 설계 및 해석에 관한 연구이다. 특히 본 연구에서는 청소기용 36000RPM급 고속 단상 BLDCM에 관한 것으로써 연자성체를 적용시 모터 특성에 영향을 미치는 인자와 설계 특성에 대하여 기술하였다. 아울러 밀도 분포를 고려한 설계 방법을 제안하여 연자성체를 이용한 모터 설계 방법의 기준을 제시하였다.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.269-273
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• 2010

Remanufacturing is an industrial manufacturing process. The merits of remanufacturing are to reuse old products to perform like a new product and to save energy, natural resources, landfill space and to reduce air pollution by less re-smelting. This paper proposes a systemic approach for activating the domestic remanufacturing industry. The approach is based on inside and outside regulations to apply remanufacturing companies. And, we analyzed the state and problems of remanufacturing industry for automobile parts.