• Laser Solutions
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• v.3 no.2
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• pp.53-61
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• 2000

On the laser weld production line, a slight alteration of the welding condition produces many defects. The defects are monitored in real time, in order to prevent continuous occurrence of defects, reduce the loss of material, and guarantee good quality. The measurement system is produced by using three photo-diodes for detection of the plasma and spatter signal in CO$_2$ laser welding. For high speed CO$_2$ laser welding, laser tailored welded blanks for example, on-line weld quality monitoring system was developed by using fuzzy multi-feature pattern recognition. Weld qualities were classified optimal heat input, a little low heat input, low heat input, and focus misalignment, and final weld quality were classified good and bad.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.499-499
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• 2008

High voltage transformer of Diagnostic X-ray system has been contributed to wiping out disease to get a good quality images from patients. High voltage transformer of diagnostic X-ray system has been usefully used for diagnostic purpose but if high voltage transformer performances are deteriorated, low quality image will be archived. In this case, operator has to exposure to get a more good quality images. In this case, unexpected radiation could be exposed to patient and it is very harmful to the patient. And I would like to design and make equipment to checkable high voltage transformer performance after that I wish to test and study what it is most influences in radiation output quality.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.6
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• pp.55-62
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• 1982

Mechanical characteristics of nodular graphite cast iron has found to tan higher utilization to the gray cast iron. So, Nodular graphite cast iron is used as a basic material in mechanical industry. Great demand of Nodular graphite cast iron is expected to increase due to the sharp development in mechanical and automobile industry. Therefore, Nodular graphite cast iron requires not only good quality product but experienced skills in manufacturing process. But there exist a lot of difficulties to manufacture nodular graphite cast iron than gray cast iron in manufacturing process. In this study, the following topics are studied for good quality product of nodular graphite cast iron. $\circled1$ Activities of managerial staff. $\circled2$ Qualite control method in manufacturing process. $\circled3$ Manufacturing process system. As a result of the study, a intensive Quality control activities should be applied and reinforced at each stage of manufacturing process rather that at the last stage of final product.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.7 s.100
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• pp.821-828
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• 2005

In our life, we have used many digital appliances. They help us to improve the quality of life but sometimes give us unsatisfactory result. Because they produce specific noise. Especially vacuum cleaner produce much noise that is very annoying. So we need to study what sound metrics affect human sensibility. In this paper, we develop sound quality index for vacuum cleaner using the sound quality metrics defined in psychoacoustics. First, we carry out the subjective evaluation of vacuum cleaner sound to verify what vacuum sound feels good to human. And then artificial neural network estimated the complexity and the nonlinear characteristics of the relations between subjective evaluation and sound metrics. Finally the ANN is trained repeatedly to have a good performance for sound qualify index of the vacuum cleaner. As a result, the sound quality index of vacuum cleaner has a correlation of $93.5\%$ between the subjective evaluation and ANN. So, there exist three factors that Is loudness, sharpness, roughness which affect the sound quality of vacuum cleaner.

• Journal of Korean Society for Quality Management
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• v.46 no.4
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• pp.785-796
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• 2018

Purpose: Currently, the morale of Quality People and Quality Department in Korea is low, so it is not doing enough work. This is one of the reasons why there is no theoretical support for the role of Role of Quality People and Quality Department. In this paper propose Role of Quality People and Quality Department in Korea. Methods: We reviewed 'Quality History' of Juran and other literature Role of Quality People and future Quality. In addition, We surveyed the actual condition of Role of Quality People and Role of Quality Department in Korean. We propose Role of Quality People and Quality Department in Korea. Results: We propose the Definition, Mission, Characteristic and Quality People Knowledge for the Role of Quality People and Role of Quality Department in Korean. Conclusion: There is still work Role of Quality People and Role of Quality Department in Korean. We expect continuously to improve Quality Competitiveness by Quality Management with good Role of Quality People and Quality Department.

• Korean Journal of Community Nutrition
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• v.24 no.5
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• pp.395-407
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• 2019

Objectives: This study examined the association of the sleep quality and patterns with the dietary behavior, including snack and beverage consumption, taste preferences, as well as lifestyle of university students. Methods: The subjects were 406 university students in Cheongju, Korea, and the data were collected using a self-administered questionnaire. They were divided into two groups according to the Pittsburgh Sleep Quality Index (PSQI): good-quality sleepers (PSQI score ≤ 5) and poor-quality sleepers (PSQI score > 5). The data were analyzed using a χ²-test, independent t-test, and analysis of covariance using the SPSS 25.0 program. Results: Fifty-two percent of university students were categorized as poor-quality sleepers by the PSQI. Students classified as poor-quality sleepers had delayed bedtimes, and a shorter duration in bed and total sleep hours than the good-quality sleepers did. Poor-quality sleepers were more prevalent among those who were female, having irregular mealtimes, or frequent late night meals. They also consumed fast food frequently, such as fried chicken and hamburgers, and noodles when adjusted for gender. In addition, drinks with caffeine over milk were dominant among poor-quality sleepers. Furthermore, the preferences for spicy and salty tastes and longer smartphone usage were more prevalent in those with poor-sleep quality. Conclusions: These results showed that more than 50% of university students reported disturbed sleep and poor quality sleep was associated with less desirable snack consumption and taste preference, more smartphone usage, and others. Therefore, nutrition education program along with lifestyle changes promoting sufficient sleep are encouraged to provide for university students, particularly those who have poor sleep quality.

• Korean Medical Education Review
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• v.23 no.2
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• pp.108-117
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• 2021

This study investigated medical students' perceptions of good jobs. We classified medical students' perceptions of good jobs and analyzed the characteristics of each type. The Q methodology was used to extract medical students' subjective thoughts. After extracting statements based on previous studies, 46 Q samples were selected. The P sample consisted of 40 medical students divided evenly by gender and grade. They performed a Q sort of the 46 Q sample questionnaire and the results were analyzed using the QUANL ver. 1.2 program. Very few consensus statements were found in the replies. We divided answers into four types, each of which was clearly distinguished: (1) quality of life-oriented jobs, (2) reward-oriented jobs, (3) service-oriented jobs, and (4) self-realization-oriented jobs. Medical students in type 1 prioritized quality of life equally at work and at home. Medical students in type 2 preferred high-paying jobs. Medical students in type 3 placed importance on serving others. Finally, medical students in type 4 viewed good jobs as involving learning and development. The types of jobs sought were classified according to individual students' values and subjectivity. Medical schools may use the results of this study as a basis for career guidance.

• International Journal of Automotive Technology
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• v.6 no.1
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• pp.53-63
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• 2005

We propose a fuzzy neural network (FNN) theory capable of deciding the quality of a road image prior to extracting lane-related information. The accuracy of lane-related information obtained by image processing depends on the quality of the raw images, which can be classified as good or bad according to how visible the lane marks on the images are. Enhancing the accuracy of the information by an image-processing algorithm is limited due to noise corruption which makes image processing difficult. The FNN, on the other hand, decides whether road images are good or bad with respect to the degree of noise corruption. A cumulative distribution function (CDF), a function of edge histogram, is utilized to extract input parameters from the FNN according to the fact that the shape of the CDF is deeply correlated to the road image quality. A suitability analysis shows that this deep correlation exists between the parameters and the image quality. The input pattern vector of the FNN consists of nine parameters in which eight parameters are from the CDF and one is from the intensity distribution of raw images. Experimental results showed that the proposed FNN system was quite successful. We carried out simulations with real images taken in various lighting and weather conditions, and obtained successful decision-making about $99\%$ of the time.

• Journal of Korean Society for Quality Management
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• v.35 no.2
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• pp.45-52
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• 2007

The danger of self-ignition of single base propellants will increase with time. Therefore, a good prediction of the safe storage time is very important. In order to determine the remaining shelf-life of the propellants, the content of stabilizer is determined. The propellants stored under normal storage conditions about 10 to 18 years were investigated and accelerated aging test was carried out by storing propellant sample at higher temperature. Finally, we analyzed the results by various methods in order to show the best way to predict the realistic shelf-life. The safe storage life of the propellants will be 24 years, at least 15 years. In case of applying Arrhenius's law, using the reaction rate constant at 28$^{\circ}C$ to 30$^{\circ}C$ to predict the shelf-life by accelerated aging test is reasonable for a good prediction.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.2
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• pp.113-123
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• 1997

This study was initiated to build runoff plots, install soil and water quality monitoring systems and collect background data from the plots and neighboring soils as the 1st year study of a 5 year project to assess soil quality and develop the management practices for environmentally sound agriculture in mountainous soils. Eleven $3{\times}15m$ runoff plots and monitoring systems were installed at a field of National Alpine Agricultural Experiment Station to monitor soil quality and discharge of nonpoint source pollutants. Corn and potato were cultivated under different fertilizer, tillage and residue cover treatments. The soil has a single-layered cluster structure that has a relatively good hydrologic properties and can adsorb a large amount of nutrient. Concentrations of T-N, $NH_4$-N, and $NO_3$-N of surface soil sampled in the winter were relatively high. Runoff quality in the winter and thawing season in the spring was largely dependent on surface freezing, snow accumulation, temperature, surface thawing depth and so on. Runoff during the thawing season caused serious soil erosion but runoff quality during the winter was relatively good. Serious wind erosion from unprotected fields after the fall harvest were obserbed and best management practices to reduce the erosion need to be developed.