• International Journal of Precision Engineering and Manufacturing
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• v.8 no.4
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• pp.10-15
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• 2007

Taguchi methods have been used for a long time to improve the product quality and process performance of a manufacturing system, Few researchers have applied this methodology in laser beam cutting (LBC) of sheet metals and found the considerable improvement in cut qualities. In all experimental investigations of LBC so far, the objective was to optimize the single quality characteristic at a time. In this paper the simultaneous optimization of multiple quality characteristics such as Kerf width and material removal rate (MRR) during pulsed Nd:YAG LBC of thin sheet of magnetic material (high Silicon-steel) has been presented using Taguchi's quality loss function. The results show the considerable improvement in multiple S/N ratio as compared to initial cutting condition. Also, the comparison of results from single and multi-objective optimization have been presented and it was found that the loss in quality is always possible shifting from single quality to multiple quality optimization.

• Journal of Environmental Health Sciences
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• v.23 no.4
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• pp.57-66
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• 1997

Successful energy conservation and good indcfor air quality (IAQ) are highly dependent on ventilation system. Air filtration is a primary solution of indoor air control strategies in terms of reducing energy consumption and improving ihdoor air quality. A conventional system with bypass filter, as it is called variable-air-volume/bypass filtration system (VAV/BPFS), is a variation of the conventional variable air volume (VAV) systems, which is designed to eliminate indoor air pollutant and to save energy. Bypass filtration system equipped with a high-efficiency particulate filter and carbon absorbent provides additional cleaned air into indoor environments and maintain good IAQ for human health. The objectives of this research were to compare the relative total decay rate of indoor air pollutant concentrations, and to develop a mathematical model simulating the performance of VAV/BPFS. All experiments were performed in chamber under the controlled conditions. The specific conclusions of this research are: 1. The VAV/BPFS system is more efficient than the VAV system in removing indoor air pollutant concentration. The total decay rates of aerosol, and total volatile organic compound (TVOC) for the VAV/BPFS system were higher than those of the conventional VAV system. 2. IAQ model predictions of each pollutant agree closely with the measured values. 3. According to IAQ model evaluation, reduction of outdoor supply air results in decreased dilution removal rate and on increased bypass filtration removal rate with the VAV/BPFS. As a results, we recommends the VAV/BPFS as an alternative to conventional VAV systems.

• Quality Improvement in Health Care
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• v.4 no.1
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• pp.36-49
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• 1997

Background : Hypertension is one of the most important risk factors of the cerebrovascular accident and coronary artery disease which are the major causes of mortality in Korea. In Korea, the quality of care provided by office-based physicians has not been evaluated formally. The purpose of this study is to assess the quality of hypertension management of office-based physicians. Method : Self-administered questionnaires were mailed to the office-based physicians with the speciality of internal medicine, general surgery, family medicine, and general practitioners. Among 2,045 physicians, 981 doctors(48.0%) replied the questionnaires. Contents of questionnaires were based on the recommendation from the JNC-V report(the Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure), and included the criteria of diagnosis, treatment, follow-up interval, and other characteristics of physicians(age, sex, type of speciality, and location of practice). Results : Eighty four percent of the office-based physicians made diagnosis of hypertension with less than 3 times of blood pressure measurements. The performance rate of required examination for hypertensives was very low in most items. Rate of fundoscopic examination is the lowest one among them(5.9%). The performance rate of laboratory examination was also low in most items. Internists tended to order more frequent laboratory examinations than any other type of physicians. Only 11.4% of the physicians did appropriate treatments for the mild hypertension case. The antihypertensives selected by the physicians as a first line drug were in the order of beta blocker(26.4%), calcium channel blocker(23.4%), diuretics(23.1%), ACE inhibitors(14.3%). The visit interval for established hypertensives was very short. Proportion of physicians with follow-up interval longer than 4 weeks was only 4.3%. Conclusions : The overall quality of hypertension management of office-based physicians in Korea is very problematic in many aspects. So further investigations to find out the reasons of low quality arid quality of care should be initiated.

• Journal of Integrative Natural Science
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• v.12 no.1
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• pp.9-13
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• 2019

Recently, as the sleep disorder problem of modern people deepens, the interest towards quality of sleep is increasing. To increase the quality of modern people's sleep. This paper has suggested an LED lighting control system according to the sleep stage using PPG sensors of wearable devices. The pulse of the wrist radial artery was measured using a wearable device mounted with PPG sensor, which enables heart rate-measuring, and by using the point that heart rate lowers during stable sleep than non-sleeping, the LED lighting of indoors was controlled, which is the disturbing element when sleeping. For the performance evaluation, a 10-Fold cross analysis was conducted for performance evaluation, and a result of an average accuracy 87.02% was obtained as a result. Therefore, the LED lighting control system according to the sleep stage using a wearable device of this paper is expected to contribute to raise the quality of the user's life.

• Fisheries and Aquatic Sciences
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• v.26 no.11
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• pp.660-668
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• 2023

This study aimed to investigate the growth performance of far eastern catfish (Silurus asotus) on outdoor fish farms to obtain basic data for the domestic eastern catfish aquaculture industry. An outdoor fish farm was directly monitored from June 2018 to October 2019 to determine the farming conditions, growth performance, and water quality. The growth performance in 2017 was analyzed using data from the same fish farm. Three years of monitoring showed that the fish farm required approximately 5-6 months between stocking, harvesting, and selling an S. asotus batch. The growth parameters, namely, the weight gain rate (WGR), specific growth rate (SGR) for culture periods, SGR for feeding periods, and feed coefficient rate (FCR), were 4,664.7%, 1.27%, 2.43%, and 1.25 in 2017; 6,452.0%, 1.52%, 2.79%, and 1.42 in 2018; and 3,270.0%, 1.11%, 2.12%, and 1.38 in 2019, respectively. Moreover, the WGR was two-fold higher in 2018 than 2019, whereas the FCR was more effective in 2019 than 2018, presumably because of the stocking density. No mass mortality was observed during the water quality analysis. The results of this study provide basic data for the development of the catfish industry.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.677-684
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• 2016

In order to improve the nighttime visibility of the lane, the need for the development of the automated line marking equipment is on the rise. The purpose of this study is to suggest performance assessment methodology that can be assessed from various aspects such as productivity, safety and quality performance of line marking equipment and to comprehensively analyze the performance of hand-operated and automated equipment based on field test. The following shows the results. It suggested a methodology capable of analyzing the performance of the line marking equipment in terms of productivity, safety and quality. Automated equipment for line marking was analyzed that can be obtained productivity achievement rate of 156.3% as compared with hand-operated equipment. On the basis of the expert advise and literature review, we derived twelve safety factors and ten quality factors of unit work in line marking. By utilizing the AHP technique, we estimated the importance of safety and quality factors. Automated equipment for line marking was analyzed to have been able to expect safety improvement rate of 49.8% and quality improvement rate of 47.2%. It is expected that the performance assessment methodology suggested in this study will be useful in analyzing objective and quantitative validity and expected effectiveness of the line marking equipment.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.810-813
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• 2007

Recently, mobile video communication is getting more and more popular. Visual quality and computational complexity are primary factors affecting performance of video communication. Frame rate up-conversion (FRC) is necessary for achieving high visual quality in mobile projection displays. In this paper, a FRC method using motion compensation based on block matching algorithm (BMA) with adaptive block size is proposed. In order to improve the accuracy of the estimated motion vectors, the motion vector refinement technique is proposed. Experiment results indicate that the proposed technique exhibits better performance with lower hardware complexity compared to the conventional methods.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.127-128
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• 2020

This research is part of the research for unifying the mass concrete and utilizing the rate of super retarding agent. We analyzed the performance of super retarding agent 20℃ conditions. It was found that there was no deterioration in fluidity and air quality due to the change in the super retarding agent mixing rate. It was found that when super retarding agent was mixed up to 0.5 %, it was delayed for 22.3 hours at 20℃. Therefore in order to ensure the performance required at the site, the super retarding agent mixing rate must be determined by fully considering the situation at the site. In addition it will be analyzed that super retarding agent performance analysis at high temperature will be required in subsequent studies.

• Journal of the Korea Safety Management & Science
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• v.7 no.5
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• pp.185-212
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• 2005

The ultimate objectives of the six sigma activities are to raise quality of products to the level where customers can be satisfied and to improve marketing efficiency through cost reduction. Recently, many businesses have been struggling to find out the most successful way to implement the six sigma to produce better results. This study is significant in a way that it provides readers with an actual evidence of efficiency and effectiveness of six sigma activities in marketing performance for the first time. The major data of this study can be divided into two categories ; First, secondary data research method was utilized to find out the effects of six sigma management on the quality and marketing performances, theoretically and empirically. Second, test of established hypotheses relevant to the effects of six sigma management on the quality and marketing performance based on the propositions drawn from existing literatures, and test hypotheses statistically. This study of six sigma looked into benefits in manufacturing industry in terms of improving quality, cutting cost and decreasing defection product-defect rate. In addition, the study has verified that how the quality performances can affect the marketing performances, such as enhancing corporate image, sales increase and customer satisfaction. The author believes that this study will help many businesses acquire best methods to increase sales and profits. And, business manager will be able to understand where to focus as they proceed with the six sigma project and improve corporate competitiveness.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.423-424
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• 2007

In this paper, we propose a scalable high-quality speech reconstruction method for distributed speech recognition (DSR). It is difficult to reconstruct speech of high quality with MFCCs at the DSR server. Depending on the bit-rate available by the DSR system, we can send additional information associated with speech coding to the DSR sorrel, where the bit-rate is variable from 4.8 kbit/s to 11.4 kbit/s. The experimental results show that the speech quality reproduced by the proposed method when the bit-rate is 11.4 kbit/s is comparable with that of ITU-T G.729 under both ideal channel and frame error channel conditions while the performance of DSR is maintained to that of wireline speech recognition.