• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.3
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• pp.56-65
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• 2001

In interpreting stream water quality data, scientific or statistical mehtods should be employed. Classical parametric statistical methods may not be adopted in analyzing water quality data, due to the violation of normality. In this study, nonparametric statistical methods, such as Kruskal-Wallis test and Mann-Whitney test, were used in comparing water quality data from several monitoring stations. Water quality data used are those collected Bokha watershed, located in Ichon-city, Kyonggi province. Based on the test results, domestic sewage is the major pollution source. A couple of sub-watersheds with a large number of livestock do not show significant differences in water quality parameters. It should be noted that comparison of mean values of water quality parameters is difficult to relate water quality with watershed characteristics. The results also indicate that livestock farming does not significantly affect the water quality.

• Journal of Community Nutrition
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• v.8 no.3
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• pp.153-159
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• 2006

The current exploratory study investigates and compares the perceptions of the service quality of in-flight meals through the evaluation of recent consumers (within 2 weeks) of services provided by Korean and foreign-based airlines. Twenty (20) items for measuring service quality were categorized into three factor dimensions of 'food quality', 'employee service', and 'professionalism'. Among these, 'employee service' was rated highest by Korean and foreign-based airlines. When items representing each service quality dimension were analyzed and compared, only the 'food quality' dimension of Korean-based airlines was perceived higher than that of other foreign-based airlines. Findings also revealed a spectrum with some items with higher or lower mean values within each service quality dimension. Results of this study can expectedly be used to benefit both from a theoretical and practical point of view by providing empirical data that measure the service quality of in-flight meal service.

• Journal of the Semiconductor & Display Technology
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• v.22 no.1
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• pp.59-63
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• 2023

Various devices have been emerging as a means of measuring indoor air quality, and among them, there are devices that support real-time remote monitoring through IoT technology and a cloud environment. To improve indoor air quality, based on the results determined by measuring devices, air purifiers or ventilation systems may need to be operated, and temperature and humidity control may be required. In this paper, we propose a design of indoor air quality measuring devices required for indoor air quality evaluation, and of the system needed to control relevant devices to improve indoor air quality through the interaction with the measuring devices. Currently, the servers for the interaction of indoor air quality devices and IoT devices are divided into conventional server type and serverless type, comparing the differences in response time of IoT devices to changes of indoor air quality.

• Journal of Environmental Science International
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• v.25 no.1
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• pp.85-97
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• 2016

A comparison of ozone simulations in the seoul metropolitan region (SMR) using the community multiscale air quality (CMAQ) model with SAPRC99 and CB05 chemical mechanisms (i.e. EXP-SP99 and EXP-CB05) has been conducted during four seasons of 2012. The model results showed that the differences in average ozone concentrations between the EXP-SP99 and EXP-CB05 were found to be large in summer, but very small in the other seasons. This can be attributed that the SAPRC99 tends to produce more ozone than the CB05 in urban area like the SMR with low VOC/NOx ratio under high ozone conditions. Through quantitative comparison between two mechanisms for the summer, it was found that the average ozone concentrations from the EXP-SP99 were about 3 ppb higher than those from the EXP-CB05 and agreed well with the observations. Horizontal differences in ozone concentrations between SAPRC99 and CB05 showed that significant differences were found in southern part of the SMR and over the sea near the coast in summer.

• Korean Journal of Remote Sensing
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• v.15 no.2
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• pp.107-117
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• 1999

A comparison of a neural network approach with the conventional statistical methods, multiple regression and band ratio analyses, for the estimation of water quality parameters in presented in this paper. The Landsat TM image of Lake Daechung acquired on March 18, 1996 and the thirty in-situ sampling data sets measured during the satellite overpass were used for the comparison. We employed a three-layered and feedforward network trained by backpropagation algorithm. A cross validation was applied because of the small number of training pairs available for this study. The neural network showed much more successful performance than the conventional statistical analyses, although the results of the conventional statistical analyses were significant. The superiority of a neural network to statistical methods in estimating water quality parameters is strictly because the neural network modeled non-linear behaviors of data sets much better.

• Journal of Korean Society for Quality Management
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• v.32 no.3
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• pp.126-140
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• 2004

The AS 9100 aerospace standard has become the aerospace quality management system standard agreed to, instead of ISO 9001 and MIL-Q-9858A by international aerospace manufacturing companies. In this paper correlative requirements of each of the standards are compared and analyzed. Then the evolutionary concept and its direction is proposed as a guide to participate in the preparation and establishment of current aerospace quality management systems. This study is applicable to the future as well as present aerospace manufacturing activities throughout the world.

• Journal of Korean Society for Quality Management
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• v.28 no.3
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• pp.31-43
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• 2000

The Service sector has increased dramatically in importance over the last decade, both internationally and in the Korea. Deregulation of services, growing competition, fluctuations in high quality demand, and the application of the Information Technologies are presenting a considerable challenge to service companies. In gas or oil companies are exposed to foreign competitions, price and promotion competition with other companies. Usually Service Quality includes five dimensions: Reliability, Responsiveness, Assurance, Empathy, and Tangibles. Customers use these five dimensions to form their judgements of service quality, which are based on a comparison between expected and perceived service. The intention of this thesis is to study on the effect of Service Quality upon the Customer Satisfaction in gas or oil station, based on SERVQUAL.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.245-253
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• 2008

Quality for civil aviation is very important to maintain the safety of aircraft and public, and strict quality requirements are prescribed in aviation regulations to ensure that each article produced conforms to the type design and is a condition for safe operation. In this study, the quality system requirements for aircraft and parts will be reviewed a concept of FAA's ACSEP(Aircraft Certification System Evaluation Program) and policy for aviation quality system evaluation in comparison with AS9100 for aviation quality management system.

• 한국전산유체공학회:학술대회논문집
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• 2002.05a
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• pp.134-139
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• 2002

This study is focused on investigating the characteristics of internal flow of the polymer reactor and its effect on the polymer quality. Four types of polymer reactor which have different kind of impeller, baffle and operation condition were calculated by CFD. Fluent 6 have been used to simulate mixing phenomena of reactor. According to the comparison of computational results and SEM photographs of polymer particle, distribution of turbulent dissipation rate greatly influences on the quality of polymer. So, distribution of turbulent dissipation rate to be important criterion to predict polymer quality.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.13-18
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• 2008

Purpose: The image processing method due to the algorism which is various portion nuclear medical image decision is important it makes holds. The purpose of this study is it applies hereupon new image processing method SIEMENS (made by Pixon co.) Onco. flash processing reconstruction and the comparison which use the image control technique of existing the clinical usefulness it analyzes with it evaluates. Materials & Methods: 1. Whole body bone scan-scan speed 20 cm/min, 30 cm/min & 40 cm/min blinding test 2. Bone static spot scan-regional view 200 kcts, 400 kcts for chest, pelvis, foot blinding test 3. 4 quadrant-bar phantom-20000 kcts visual evaluation 4. LSF-FWHM resolution comparison ananysis. Results: 1. Raw data (20 cm/min) & processing data (30 cm/min)-similar level image quality 2. Low count static image-image quality clearly improved at visual evaluation result. 3. Visual evaluation by quadrant bar phantom-rising image quality level 4. Resolution comparison evaluation (FWHM)-same difference from resolution comparison evaluation Conclusion: The study which applies a new method Onco. flash processing reconstruction, it will be able to confirm the image quality improvement which until high level is clearer the case which applies the method of existing better than. The new reconstruction improves the resolution & reduces the noise. This enhances the diagnostic capabilities of such imagery for radiologists and physicians and allows a reduction in radiation dosage for the same image quality. Like this fact, rising of equipment availability & shortening the patient waiting move & from viewpoint of the active defense against radiation currently becomes feed with the fact that it will be the useful result propriety which is sufficient in clinical NM.