• Journal of Korean Society for Quality Management
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• v.38 no.3
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• pp.439-448
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• 2010

Since the six sigma strategy was first introduced to Motorola in 1987, it has been taken as an important business strategy to strengthen the competitiveness of leading companies in the global competitiveness environm ent. This paper presents a six sigma project to reduce the cycle time of assembly line in a medium size automotive part company. The project follows a structured methodology of DMAIC cycle which consists of Define, Measure, Analyze, Improve, and Control. A CTQ is determined based on COPQ analysis, and a process map is utilized for identifying process input variables. As a result of the project, two assembly lines are converted to cell line production lines. The cycle times become 55 sec./unit and 64 sec./unit from 64 sec./unit and 83 sec./unit at the beginning of the project, respectively.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.10
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• pp.53-58
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• 1999

Even I the Electronic Speckle Pattern Interferometry(ESPI) method that measure the strain of object within wavelength of light is less visibility than Holographic Interferometry(HI) method, the merits of application, convenience and time-save have made the method practical in industry. However, the existing ESPI methods that are based on dual-exposure, real-time and time-average method have difficulties for accurate measurement, due to irregular intensity and shake of phase. Recently, in order to solve this problem, phase shifting method have been proposed. In this method, the path of reference light in interference is shifted to make improvement in distinction and precision. But this method includes too many noise, caused by the problem of relationship between object and phase. Therefore, a method to reduce noise muse be introduced. In this paper, least square fitting method is proposed. As results, the phase-map is influenced by precise phase shifting and current of notes and speckle pattern obtained by phase shifting method is improved on the existing method driven from time-average method.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.355-360
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• 1998

A small package of plasma instruments, Space Physics Sensor, will monitor the space environment and its effects on microelectronics in the low altitude region as it operates on board the KOMPSAT-1 from 1999 over the maximum of the solar cycle 23. The Space Physics Sensor (SPS) consists of two parts: the Ionospheric Measurement Sensor (IMS) and the High Energy Particle Detector (HEPD). IMS will make in situ Measurements of the thermal electron density and temperature, and is expected to provide a global map of the thermal electron characteristics and the variability according to the solar and geomagnetic activity in the high altitude ionosphere of the KOMPSAT-t orbit. HEPD will measure the fluxes of high energy protons and electrons, monitor the single event upsets caused by these energetic charged particles, and give the information of the total radiation dose received by the spacecraft. The continuous operation of these sensors, along with the ground measurements such as incoherent scatter radars, digital ionosondes and other spacecraft measurements, will enhance our understanding of this important region of practical use for the low earth orbit satellites.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.742-749
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• 2006

For the purpose of finding if aircraft noise annoyance response is affected to variables when noise survey is performed, the questionnaire survey is conducted around the Gimpo International Airport in Seoul, Republic of Korea. This residential area is exposed to the aircraft noise and road traffic noise, simultaneously. Research areas are classified according to three different aircraft noise exposure levels expressed in WECPNL, under 75, between 75 and 80, and above 80 WECPNL, on aircraft noise map. The 7-step numerical magnitude with verbal category scales is used to measure the annoyance level. This surrey suggests that aircraft noise annoyance is not affected to an important extent by other noise sources (road traffic noise, community noise) and demographic variables (sex, age, education, occupation, dwelling type, length of residence). Aircraft noise annoyance would be related to complaint activity which is one of attitudinal variables.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.08a
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• pp.75-87
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• 2005

Remote sensing(RS)- and geographic information system(GIS)-based information management to measure and assess agri-environment schemes, and to quantify and map environment indicators for nature and land use, climate change, air, water and energy balance, waste and material flow is in high demand because it is very helpful in assisting decision making activities of farmers, government, researchers, and consumers. The versatility and ability of RS and GIS containing huge soil database to assess agricultural environment spatially and temporally at various spatial scales were investigated. Spectral and microwave observations were carried out to characterize crop variables and soil properties. Multiple sources RS data from ground sensors, airborne sensors, and also satellite sensors were collected and analyzed to extract features and land cover/use for soils, crops, and vegetation for support precision agriculture, soil/land suitability, soil property estimation, crop growth estimation, runoff potential estimation, irrigated and the estimation of flooded areas in paddy rice fields. RS and GIS play essential roles in a management and monitoring information system. Biosphere-atmosphere interection should also be further studied to improve synergistic modeling for environment and sustainability in agri-environment schemes.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.243-248
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• 2007

Rice is a facultative short-day plant that flowers in response to reduced day lengths. This study was conducted to identify quantitative trait loci(QTL) for the early heading date(EHD) using H143 line showing extreme EHD compared to other regular cultivars in rice. The japonica H143 was crossed with a japonica cultivar 'Dongjinbyeo' as well as a tongil cultivar 'Milyang23' to measure the inheritance mode of EHD and identify major QTL conferring EHD, respectively. Pooling test revealed that segregation distortion occurred on chromosome 7 and subsequent linkage map was constructed using 10 SSR markers. QTL analysis using Q-gene 3.06 revealed that the EHD trait in H143 was largely controlled by two major QTL, EH7-1 and EH7-2, accounting for more than 40% of genetic variation that were closely related to the previously reported QTL, Hd4 and Hd2, respectively. This result suggests that these two QTL markers may be a useful source for the control of heading date in rice breeding programs.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.8
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• pp.1365-1375
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• 1997

Jacket is the basic formal dress for working women, and one of the most frequently worn by them. It has, however, some problems caused by movement, depending on how well it fits. To improve fitness of jacket, this study compared and evaluated the state of fitness objectively by employing a numerical system in relation with clothing and body. We made three experimental jackets based on the previous jacket patterns and used Moire Photo-graphy to measure the amounts of space between clothes and body from the overlap cross section map. The results obtained from this study were summarized as follows; 1. According to the measurement result of the pattern by using the One-dimension measurement, the amount of ease in girth item for pattern B was larger than the other two patterns. The amounts of space of each part showed the difference of the positions of princess lines, and the different sizes of the darts. 2. From the result of Moire Photography, the wearing shapes of the experimental jackets were influenced by the characteristics of somatotype. In addition, we could analyze the differences of the patterns with Moire Photography. 3. The amounts of space for waist part was larger than those for other parts. Pattern B scored the largest amount of space for all parts compared with pattern A and C. 4. For only waist part, there existed a significant difference in the average amount of space for the three patterns.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.58-65
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• 2004

A cylindrical constant volume combustion chamber was used to investigate the combustion characteristics of stratified methane-air mixture under several initial charge conditions in the author's previous reports. The results showed that the improvement of thermal efficiency and reduction of heat loss was realized simultaneously by using 2-stage injection method. This paper deals with the reason why the stratified combustion has showed better combustion rate through the measurement and analysis of chemiluminescence of C $H^{*}$ and $C_{2}$$^{*}$ radicals. An optic fiber bundle is used to measure the local emission of C $H^{*}$ and $C_{2}$$^{*}$ radicals to map the relationship between the excess air ratio and local radical intensity ratio in the combustion vessel at 5 mm apart form the geometric center. The results show that there exist a relationship between the intensity ratio and the air-fuel ratio. It is revealed that the improvement of combustion rate in a lean-stratified mixture is realized through the 2-stage injection method. method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.2
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• pp.103-111
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• 2015

In general, no particularly well-established standards have been in place so far, for the method of evaluating the deteriorated level of pipes and ducts of industrial facilities. For that reason, the evaluation depends upon various studies which are based on the analysis of the residual life, thickness thinning, closure rate, and scale thickness that measure a few specific positions of pipes. It also depends upon the expertise in business operation and the specific techniques conducted by the inspection companies and institutions. This research introduces the concept of measuring units per section and the selection method of measurement points per section. Furthermore, specific methodologies were developed to plan and analyze deterioration level of industrial pipes and ducts by engineers and managers using a section map. Consequently, applying the outcomes from this study to the plant equipment of the incineration facility resulted in saving 42% of the repairing and remodeling cost.

• Korean Journal of Computational Design and Engineering
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• v.12 no.4
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• pp.255-262
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• 2007

In the finite element analysis of forming process, objects are described with a finite number of elements and nodes and the approximated solutions can be obtained by the variational principle. One of the shortcomings of a finite element analysis is that the structure of mesh has become inefficient and unusable because discretization error increases as deformation proceeds due to severe distortion of elements. If the state of current mesh satisfies a certain remeshing criterion, analysis is stopped instantly and resumed with a reconstructed mesh. In the study, a new remeshing algorithm using tetrahedral elements has been developed, which is adapted to the desired mesh density. In order to reduce the discretization error, desired mesh sizes in each lesion of the workpiece are calculated using the Zinkiewicz and Zhu's a-posteriori error estimation scheme. The pre-constructed mesh is constructed based on the modified point insertion technique which is adapted to the density function. The object domain is divided into uniformly-sized sub-domains and the numbers of nodes in each sub-domain are redistributed, respectively. After finishing the redistribution process of nodes, a tetrahedral mesh is reconstructed with the redistributed nodes, which is adapted to the density map and resulting in good mesh quality. A goodness and adaptability of the constructed mesh is verified with a testing measure. The proposed remeshing technique is applied to the finite element analyses of forging processes.