• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.281-282
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• 2012

Construction performance and productivity improvement are key focus areas in construction industry for any nation. There have been frequent delays and cost overruns in construction projects and poor productivity is one of the major contributions. For this reasons, there have been many research studies performed on the improvement of construction productivity for several decades. However, measuring productivity on a construction job site is still not an easy work. Because collecting reliable data consistently from the job site requires a lot of personnel efforts causing extra time and cost. This paper provides a basic study on the application of image processing technology for measuring unit productivity. It presented the possibility of unit productivity measurement by image processing technology through case study.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.201-211
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• 1998

The fundamental object of work measurement is to precisely establish the time standards, which are the indices of labor productivity. This study discussed the development of robot work measurement method that could establish the time standard effectively. In manufacturing industries the various robot tasks are generally classified and standardized by the unit motions. The Robot Modularization of the Unit Motion (ROMUM) was realized by the module of two steps GET and PUT unit motions. This method reduced time and effort of analysis, and could be done with ease. Therefore, ROMUM will increase the convenience of use for the unskilled worker and decrease the time required, cost and errors. And, it will contribute to reduce the unnecessary motion by robot motion analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.925-928
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• 1995

Recently, the system of the industry demands quick and accurate measurement for the mass production and high quality. Also, we need to improve the accuracy to decrease the failure rate in automatic assembly processing and improve the confidence, durability and the compatibility of parts. To answer this tendency and requirement, we have developed many accrate measuring instruments and methods. In this paper, we develop the whidows program using the DSP board(TMS320C25) which is used the data acquisition and the Visual C $^{++}$ , a windows programming language. We perform the measurement, analysis and output process in GUI(Graphic User Interface)environment. By using system, we will save the time required for the hand-worked measurement and avoid the useless iterative measurement. Furthermore, we expect to improve the productivity through automotive quality control in manufacturing process.s.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.2
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• pp.51-58
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• 2015

In this study, we developed an automated non-contact thickness measurement machine that continuously and precisely measures the thickness and warp of a PCB product using a laser sensor. The system contains a measurement part to measure the thickness in real time automatically according to the set conditions with an alignment supply unit and unloading unit to separate OK and NG products. The measurement machine was utilized to evaluate the performance at each step to minimize measurement error. At the zero setting for the initial setup, the standard deviation of the 216 samples was determined to be $5.52{\mu}m$. A measurement error of 0.5mm and 1.0mm as a standard sample in the measurement accuracy assessment was found to be 2.48% and 2.28%, respectively. In the factory acceptance test, the standard deviation of 1.461mm PCB was measured as $28.99{\mu}m$, with a $C_{pk}$ of 1.2. The automatic thickness measurement machine developed in this study can contribute to productivity and quality improvement in the mass production process.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.120-128
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• 2000

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric errors, thermally-induced errors, and the deterioration of the machine tools. Geometric and thermal errors of machine tools should be measured and compensated to manufacture high quality products. In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. This paper models of the thermal errors for error analysis and develops on-the-machine measurement system by which the volumetric error are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses and a designed spherical ball artifact (SBA). Experiments, performed with the developed measurement system, show that the system provides a high measuring accuracy, with repeatability of $\pm$2${\mu}{\textrm}{m}$ in X, Y and Z directions. It is believed that the developed measurement system can be also applied to the machine tools with CNC controller. In addition, machining accuracy and product quality can be improved by using the developed measurement system when the spherical ball artifact is mounted on the modular fixture.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.111-117
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• 2000

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric errors, thermally-induced errors, and the deterioration of the machine tools. Geometric and thermal errors of machine tools should be measured and compensated to manufacture high quality products. In metal cutting, the machining accuracy is more affected by thermal errors than by geometric errors. This paper models the thermal errors for error analysis and develops an on-the-machine measurement system by which the volumetric errors are measured and compensated. The thermal error is modeled by means of angularity errors of a column and thermal drift error of the spindle unit which are measured by the touch probe unit with a star type styluses and a designed spherical ball artifact (SBA). Experiments show that the developed system provides a high measuring accuracy, with repeatability of $\pm$2$\mu\textrm{m}$ in X, Y and Z directions. It is believed that the developed measurement system can be also applied to the machine tools with CNC controller. In addition, machining accuracy and product quality can be also improved by using the developed measurement system when the spherical ball artifact is mounted on a modular fixture.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.363-368
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• 2002

An automobile hub is composed of a hollow cylindrical part with inner and outer diameters. These hub diameters must be precise, as any irregularities in them (diameters) can influence/degrade the motion of an automobile with this problem. Highly accurate and reliable hub inner and outer diameters measurement systems are therefore required for inspection of the diameters. In this research, an automobile hub inner and outer diameters measurement system has been developed and tested. The system consists of measuring heads with LVDT sensors, and associated software for automatic measurement and calibration of the diameters and the sensors respectively. The system has been evaluated in comparison with an existing measurement system, and the following outcomes have been achieved; .Improved and guaranteed quality and reliability .Increased productivity and cost reduction. These results prove the system developed in this research to be suitable for automobile hub inspection.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.15.2-15.2
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• 2009

Manufacturing of printed electronics using printing technology has begun to get into the hot issue in many ways due to the low cost effectiveness to existing semi-conductor process. This technology with both low cost and high productivity, can be applied in the production of organic thin film transistor (OTFT), solar cell, radio frequency identification (RFID) tag, printed battery, E-paper, touch screen panel, black matrix for liquid crystal display (LCD), flexible display, and so forth. The emerging technology to manufacture the products in mass production is roll-to-roll printing technology which is a manufacturing method by printings of multi-layered patterns composed of semi-conductive, dielectric and conductive layers. In contrary to the conventional printing machines in which printing precision is about $50~100{\mu}m$, the printing machines for printed electronics should have a precision under $30{\mu}m$. In general, in order to implement printed electronics, narrow width and gap printing, register of multi-layer printing by several printing units, and printing accuracy of under $30{\mu}m$ are all required. We developed the roll-to-roll printing equipment used for printed electronics, which is composed of un-winder, re-winder, tension measurement system, feeding units, dancer systems, guide unit, printing unit, vision system, dryer units, and various auxiliary devices. The equipment is designed based on cantilever type in which all rollers except printing ones have cantilever types, which could give more accurate machine precision as well as convenience for changing rollers and observing the process.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.201-210
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• 1999

One of the major limitations of productivity and quality in metal cutting is the machining accuracy of machine tools. The machining accuracy is affected by geometric and thermal errors of the machine tools. Therefore, a key requirement for improving te machining accuracy and product quality is to reduce the geometric and thermal errors of machine tools. This study models geometric error for error analysis and develops on-machine measurement system by which the volumetric erors are measured. The geometric error is modeled using form shaping function(FSF) which is defined as the mathematical relationship between form shaping motion of machine tool and machined surface. The constant terms included in the error model are found from the measurement results of on-machine measurement system. The developed on-machine measurement system consists of the spherical ball artifact (SBA), the touch probe unit with a star type stylus, the thermal data logger and the personal computer. Experiments, performed with the developed measurement system, show that the system provides a high measuring accuracy, with repeatability of ${\pm}2{\mu}m$ in X, Y and Z directions.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.95-100
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• 2004

본 논문은 도로 건설 공사 프로젝트들의 전 공정에 걸쳐 수행되는 모든 작업들을 대상으로 총 프로젝트 생산성 (Total Project Productivity)을 측정하고 분석하기 위한 방법을 소개한다. 측정 방법의 주안점은 복합적으로 병행되는 작업들의 생산량을 통합하여, 프로젝트 전체에 대한 포괄적인 생산성 값들을 구하는 방법을 개발하는데 두고 있다. 이 방법을 통해 Florida Department of Transportation (FDOT)로부터 발주된 세 개의 실제 고속도로 건설 공사 프로젝트들로부터 수천 개의 총 프로젝트 생산성 데이터 값들이 얻어졌으며. 이를 바탕으로 프로젝트 생산성을 분석하기 위한 방법의 타당성 검증이 이루어졌다. 그 결과로, 프로젝트 레벨에서의 총 생산성은 건설 작업들에 관한 현장 자료를 바탕으로 측정과 분석이 이루어질 수 있음이 입증되었다.