• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.97-98
• /
• 2023

In this study, comparison of the quality standard of chemical admixtures between Korea and China is conducted. It is classified into three types of water reducing agents: standard, delayed, and accelerated according to the sensitivity and strength improvement of the sensitivity and strength of the agent. However, Chinese standards classify reducing agents only as standard, high efficiency, and high performance, and do not add AE agents into water reducing agent. On the other hand, that of Korea has a classification regulation for reducing agents added with AE agents.

• International Journal of Contents
• /
• v.11 no.2
• /
• pp.20-30
• /
• 2015

We propose a new method that specifies objective image quality factors by evaluating an image quality measurement model using random images. In other words, No-Reference variables are used to evaluate the quality of an original image without using any reference for comparison. 1000 portrait images were collected from a web gallery with votes constituting over 30 recommendation values. The bottom-up data collecting process was used to calculate the following image quality factors: total range, average, standard deviation, normalized distribution, z-score, preference percentage. A final grade is awarded out of 100 points, and this method ranks and grades the final estimated image quality preference in terms of total image quality factors. The results of the proposed image quality evaluation model consist of the specific dynamic range, skin tone R, G, B, L, A, B, and RSC contrast. We can present the total for the expected preference points as the average of the objective image qualities. Our proposed image quality evaluation model can measure the preferences for an actual image using a statistical analysis. The results indicate that this is a practical image quality measurement model that can extract a subject's preferred image quality.

• Proceedings of the KSMRM Conference
• /
• 1999.11a
• /
• pp.36-36
• /
• 1999

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2001.04a
• /
• pp.71-72
• /
• 2001

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1998.04a
• /
• pp.94-101
• /
• 1998

This paper presents the psychoacoustic analyses on the vehicle interior, noise generated when accelerating. Following the objective quantification for vehicle noises of different classes, the subjective decision process by the jury test is adopted to interrelate these results based on two different approaches. In particular, the paired comparison method is employed in assessing the sound quality in terms of the quietness, the powerfulness, and the pleasantness of the human auditory sensation. Special attention is paid to the physical interpretation of psychoacoutic parameters and their interrelation to the subjective assessment scores. In order to ensure the integrity of statistics of the survey, various tests are performed. The results show that the consistency of the "quiet" sensation is far higher than that of the "powerful" and the "pleasant" sensations. Also, it is found that the most significant parameter determining these feelings turns out to be the inherent loudness of the noise instead of the conventional indicators such as the weighted sound pressure level. It may be concluded that the psychoacoustic analysis offers more realistic evaluation for vehicle noise and assists the improvement of NVH more efficiently.ement of NVH more efficiently.

• Journal of Haehwa Medicine
• /
• v.22 no.2
• /
• pp.119-141
• /
• 2014

Objective : This study was designed to health-Care services recognition comparison of patient between Korean Medicine 00 Hospital and Seoul 00 Health Center. Methods : 277 subjects were participated in this study. After a treatment, we analyzed a patient type by using a questionnaire. After all treatment, we conducted a survey about Medical Trust Scale, Medical Happiness Index Scale, Service Quality Scale. To evaluate a satisfaction degree, we analyzed results of survey statistically. Results : The results of the analysis, Korean Medicine 00 Hospital group got a higher score than Seoul 00 Health Center group statistical significantly on Medical Trust Scale, Medical Happiness Index Scale, Service Quality Scale. Conclusion : Korean Medicine 00 Hospital group got a higher score than Seoul 00 Health Center group. It was more effective in Korean Medicine 00 Hospital group than Seoul 00 Health Center group.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.26 no.5
• /
• pp.578-583
• /
• 2016

In order to provide a basis data for design of small arms and their silencer, an experimental study on firing noise of small arms was performed around the muzzle of a gun. For this experimental comparison analysis, the target small arms were included most operating small arms in our country. The sound pressure levels were measured at a certain distance which was predetermined according to US army firing test procedure, TOP 3-2-045. By this experimental study, the sound pressure levels of 5.56 mm caliber small arms are 143 dB ~ 145.4 dB and 7.62 mm caliber small arms are 144 dB ~ 145.2 dB. Between the heavy machine gun K12 and M60, the sound pressure level of K12 is slightly lower than M60.Also silencer for K14 snifer rifle was tested. Using this result, it has been found that the reduction effect of the silencer is 15.4 dB but the improvements of silencer performance in the high frequency range have to be studied later on.

• Journal of the Korean Society of Food Culture
• /
• v.27 no.5
• /
• pp.481-489
• /
• 2012

This study examines the effects of restaurant attributes on customers' perceptions of price and brand reputation. Four restaurant attributes were used to represent restaurant quality. Multiple regression was conducted to measure the relationships between the four restaurant attributes and price and brand reputation. Further, an independent T-test was used to compare differences between perceptions of locals and tourists with regard to restaurant quality under two categories (price and brand reputation) after they selected a restaurant. Results of this study revealed that residency did not have a significant impact on customers' perceptions of price or brand reputation, whereas restaurant attributes did have an impact. Taste was a predictor of perceived price, whereas service and atmosphere were predictors of brand reputation. In addition, comparison of restaurant attributes between locals and tourists showed that sanitation and service were significantly different in accordance with price and atmosphere, whereas taste and service were significantly different in accordance with brand reputation. Locals showed higher means for each restaurant attribute compared to tourists.

• Applied Chemistry for Engineering
• /
• v.25 no.6
• /
• pp.639-644
• /
• 2014

Domestic vehicle companies have been selling genuine engine oils with higher price than that of the same grade of regular engine oils. In this study, our group investigated the properties of engine oils for 14 kinds of the genuine and equivalent regular engine oil (KS product) species under a fresh as well as used condition recovered after 10,000 km driving. From analytic results, genuine engine oils had similar physical properties to regular engine oils under the fresh condition. But recovered regular engine oils had better properties in lubricity, kinematic viscosity and acid number change than those of recovered genuine engine oils.

• Imaging Science in Dentistry
• /
• v.34 no.3
• /
• pp.117-122
• /
• 2004

Purpose : To determine the proper image compression method and ratio without image quality degradation in intraoral digital radiographic images, comparing the discrete cosine transform (DCT)-based JPEG with the wavelet-based JPEG 2000 algorithm. Materials and Methods : Thirty extracted sound teeth and thirty extracted teeth with occlusal caries were used for this study. Twenty plaster blocks were made with three teeth each. They were radiographically exposed using CDR sensors (Schick Inc., Long Island, USA). Digital images were compressed to JPEG format, using Adobe Photoshop v.7.0 and JPEG 2000 format using Jasper program with compression ratios of 5 : 1,9 : 1, 14 : 1,28 : 1 each. To evaluate the lesion detectability, receiver operating characteristic (ROC) analysis was performed by the three oral and maxillofacial radiologists. To evaluate the image quality, all the compressed images were assessed subjectively using 5 grades, in comparison to the original uncompressed images. Results: Compressed images up to compression ratio of 14 : 1 in JPEG and 28 : 1 in JPEG 2000 showed nearly the same the lesion detectability as the original images. In the subjective assessment of image quality, images up to compression ratio of 9 : 1 in JPEG and 14 : 1 in JPEG 2000 showed minute mean paired differences from the original Images. Conclusion : The results showed that the clinically acceptable compression ratios were up to 9 : 1 for JPEG and 14 : 1 for JPEG 2000. The wavelet-based JPEG 2000 is a better compression method, comparing to DCT-based JPEG for intraoral digital radiographic images.