• 산업공학
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• 제21권4호
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• pp.411-417
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• 2008

An impeller is a type of high-speed rotor that is used to compress or transfer fluid under high-speed and pressure at high temperatures. The impeller is composed of an axial hub and several blades attached along the hub. The weight and shape of an impeller must be balanced, because their imbalances can cause noise and vibration, which can lead to the breakage of the impeller blades during operation. Thus, the hub and blades of an impeller are commonly machined in a 5-axis NC machine to obtain qualified surfaces. The impeller machining strategy or process plan can not be easily obtained due to the complex, overlapped and twisted shapes of impeller blades. Skillful machining process planners may generate appropriate machining strategies based on their experiences and floor data. However, in practice most shop floor data for the impeller machining is not well-structured such that it does not effectively provide a process planner with information for machining strategies and/or process plans. This paper reports the development of a case-based machining strategy support system (CBMS) that employs case-based reasoning to obtain the machining strategy of an impeller by using the existing machining strategies of the shop floor. The CBMS generates impeller machining strategies through a stepwise reasoning process considering the similarity features between the blade shapes and machining regions. A case study is provided to demonstrate that CBMS can generate useful machining strategies facilitating process planners. The developed system can simulate the tool paths of impeller machining and runs on the web.

• 한국전자거래학회지
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• 제27권2호
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• pp.205-218
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• 2022

최근 제조업에서의 디지털 전환이 가속화되고 있다. 이에 따라 사물인터넷(internet of things: IoT) 기반으로 현장 데이터를 수집하는 기술의 중요성이 증대되고 있다. 이러한 접근법들은 주로 각종 센서와 통신 기술을 활용하여 특정 제조 데이터를 확보하는 것에 초점을 맞춘다. 현장 데이터 수집의 채널을 확장하기 위해 본 연구는 비전(vision) 인공지능 기반으로 제조 데이터를 자동 수집하는 방법을 제안한다. 이는 실시간 영상 정보를 객체 탐지 및 추적 기술로 분석하고, 필요한 제조 데이터를 확보하는 것이다. 연구진은 객체 탐지 및 추적 알고리즘으로 YOLO(You Only Look Once)와 딥소트(DeepSORT)를 적용하여 프레임별 객체의 움직임 정보를 수집한다. 이후, 움직임 정보는 후보정을 통해 두 가지 제조 데이터(생산 실적, 생산 시간)로 변환된다. 딥러닝을 위한 학습 데이터를 확보하기 위해 동적으로 움직이는 공장 모형이 제작되었다. 또한, 실시간 영상 정보가 제조 데이터로 자동 변환되어 데이터베이스에 저장되는 상황을 재현하기 위해 운영 시나리오를 수립하였다. 운영 시나리오는 6개의 설비로 구성된 흐름 생산 공정(flow-shop)을 가정한다. 운영 시나리오에 따른 제조 데이터를 수집한 결과 96.3%의 정확도를 보였다.

• 한국농촌건축학회논문집
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• 제16권1호
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• pp.63-70
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• 2014

This study is aimed to represent the streetscape in 1960s' focused on Seong-An street of Cheong-ju through the existing business types and buildings, literature, photo details, and interview of the longest-term householders. Results of this study are as follows : Firstly, the types of 1st-floor shops were diverse with general merchandise, apparel, medical, bank, restaurant, and etc in 1960s'. The present shops of them are 'Dong-kwang lasa', 'Jung-geum dang', 'Cheong-ju pharmacy' including the existing 'the Korea development', 'Korea first', and 'Woori' bank. Secondly, the streetscape around post office looks just as it did in the old 1960s'. In the other section the present typical buildings are 'Namseon pharmacy ', 'Kukje department', 'Samyang shop', 'Daeyang shop', 'Park shop', and etc. These old 3-4story buildings are reinforced concrete in contrasted with the former wooden and masonry in structure, and converted in use and appearance. Thirdly, the streetscape of Seong-An is ultimately represented by presuming the other buildings and equipments through aerial and street photograph in the old 1960s'.

• 산업공학
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• 제10권2호
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• pp.57-67
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• 1997

This paper is a report of a simulation study that investigates a dynamic approach to scheduling jobs in a conventional shop floor, especially in an assemoly-type welding process. We consider both JIT arrival and JIT delivery. Various dispatching rules are tested for the following performance measures; mean flow time, rate of tardy jobs, mean tardiness, sum of mean tardiness and mean earliness. The results indicate that SPT rule is the best for the mean flow time. MSLACK that we suggest in this paper, is the best for the mean tardiness and the sum of mean tardiness and mean earliness. However, it is not clear that which rule is the best for the rate of tardy jobs.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.627-630
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• 1996

One of the most common communication mechanisms to describe a situation or a process is a story written as an ordered sequence of events or activities. For example, a shop floor supervisor may present the operations of his manufacturing system by describing the processes of manunfacturing a product in his shop. Although IDEF3 is one of the most commonly used methods for describing a business process, but it is not common for a manufacturing process. In this study, we tried to apply IDEF3 for describing a manufacturing process. Problems and suggestions such as selection probability, programmable process modeling, manufacturing resource model were presented.

• 한국국방경영분석학회지
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• 제22권2호
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• pp.153-165
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• 1996

This paper presents an order releasing algorithm for an AMS. Order release policy determine order releasing time to shop floor so as to improve order management and shop performance. The proposed order releasing algorithm can cope with the dynamic environment of orders(e.g. change or cancel of order) flexibly and fastly, by processing individual order and exchanging the information(e.g. compeletion time or lateness of order, etc) with customer. And the objective of the order releasing algorithm is the observance of the due-date, therefore, it can provide customer with a reliability of order. Computer simulation is used to obtain the makespan of order which is the input data of the order releasing algorithm. The eight candidate part dispatching rules are simulated to selected an effective part dispatching rule for the computer simulation. By using the best effective part dispatching rule, the computer simulation is conducted to determine order releasing time.

• 한국정밀공학회지
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• 제16권5호통권98호
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• pp.91-97
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• 1999

The background of appearing MMS is to cope with the difficulty that occurred in constructing CIM with multi-vendor production devices such as CNC, PLC and robot. But so far the popularized use of MMS service in machine shop is not generalized because of economical and environmental reason. In this paper to solve this problem the CNC_VMD gateway for 3 types of heterogeneous machine tools in which MMS support is not available is developed and its performance is evaluated in shop floor having CIM environment. The developed VMD has the functions such as MMS service, driver for CNC interface and supporting for network. Non-MMS compatible machine tool can be MMS-compatible by using the developed gateway with CNC_VMD.

• 대한산업공학회지
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• 제13권1호
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• pp.11-24
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• 1987

Automatic Guided Vehicle Systems feature battery powered driverless vehicles with programming capabilities for path selection and positoning. Vehicles serve the machines in shop, following a guide path system installed on the shop floor. The basic problem in the system is to determine a fixed set of vehicle routes of minimal total distance(time) while keeping capacity and distance(time) constraints. In this paper, a heuristic algorithm is presented for scheduling the automatic guided vehicles. The algorithm routes the machines based on their distances and polor coordinate angles, taking into account the structural feature of the system. Computational experiments are performed on several test problems in order to evaluate the proposed algorithm. Finally, a framework for dealing with the case where supplies from the machines are probabilistic is described.

• 대한안전경영과학회지
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• 제5권4호
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• pp.209-217
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• 2003

The traditional Kanban needs a lot of preconditions for fitting conditions of dynamic production processing environment. The traditional Kanban isn't suitable conditions of dynamic production processing environment. Therefore conditions of dynamic production processing environment is needed more stable system. This study is describe CONWIP system such as suitable in dynamic production processing environment. Most Pull system is a Kanban system than use Kanban cards or signal for production management and inventory control. The object of Kanban system is reducing inventory between shop-floor that can reduce inventiry cost. If the system reduce the number of Kanban cards would be reduce the working process WIP, can be reduced and can be found all potential problem of production between shop-floors. This study apply to CONWIP system model for Korean industrial companies.

• 품질경영학회지
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• 제31권1호
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• pp.1-10
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• 2003

In 1999, Six Sigma was introduced into Korea and after that it had general influence on company-wide management system. Quality Circles apply the various quality problem solving techniques such as QC 7 Tool, New QC 7 Tool, and statistical methods to rationalization, improvement in the shop floor. This paper empirically investigates the effects of Six Sigma on Quality Circles by analyzing the difference of problem solving technique's use. The number of teams employed in this study is 342, which participate in National Quality Circles Contest from 1997 to 2002 in Korea.