• Journal of the Korean Society of Radiology
• /
• v.15 no.5
• /
• pp.621-628
• /
• 2021

Prior studies on frequency-related image quality analysis of intravascular ultrasound catheters are lacking both in Korea and abroad. Therefore, this study was conducted to prepare a standard for measuring the image quality using the program and to suggest a measuring method to researchers related to the quality analysis of intravascular ultrasound images. For the target, the vessel lumen size is 3.0 - 4.0 mm. Before using intravascular ultrasound, thoroughly clean the ultrasound catheter so that no air or foreign substances enter it. Normal vascular images and lesion vascular images of sufficiently dilated images were used. As a standard image acquisition method, the image of the end-systolic section, which has the best evaluation of vascular lesions when using intravascular ultrasound, was acquired retrospectively through the DCAS PACS program to set the standard. When setting the measurement method criteria, we proposed a standard setting method that corresponds to the concentric and eccentric circles of normal and lesion vessels. By applying this criterion, we proposed a method for measuring the lumen and lateral cavities of normal and lesion vessels of interest and background area. In conclusion, if the image quality of intravascular ultrasonography is measured through the method devised by these researchers, consistent quality measurement is possible regardless of the type of intravascular ultrasound catheter. Therefore, it is thought that it can be applied as a guideline for the actual image quality measurement method in the study related to intravascular ultrasound image quality.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.10 no.2
• /
• pp.133-142
• /
• 2022

The purpose of this study is to develop an impact crusher with a radial rotating plate installed at the bottom, which is a shock absorber that can produce high-quality recycled coarse aggregate for concrete and to verify the effect of improving the quality performance of recycled coarse aggregate and its applicability through concrete tests. As a result, it showed improved quality in all items such as absolute dry density, absorption rate, abrasion resistance, Particle shape judgment rate, amount lost in the 0.08 mm sieve passing test, alkali aggregate reaction, clay mass, stability, and impurity content, and it was found to meet the criteria of recycled aggregate quality standards. In addition, the air volume and slump of concrete to which recycled coarse aggregate is applied meet all domestic standards. According to the test results of the compressive strength characteristics by age of concrete according to the mixing ratio of the recycled coarse aggregate, it was confirmed that the mixing ratio of the recycled coarse aggregate was applicable up to 60 %.

• Journal of the Korean Institute of Gas
• /
• v.26 no.6
• /
• pp.24-29
• /
• 2022

This paper is a purpose to Analyze and study the failure examples for a engine oil leakage of camshaft bearing seal, poor contact by computer connector fin damage and vaporizer inferiority on LPG automotive. The first example, when the researcher disassembled the cylinder head of engine to establish the cause for oil leakage, he confirmed the engine oil leakage by damaged between the engine intake camshaft bearing and seal part. The second example, the connector fin of power source line that control the starting of a car supplied with engine computer. As a result, it found the fact that the engine operation stopped because of cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phe cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phenomenon as thd gas didn't flow the vaporizer by foreign substance deposit. Finally, it supplied a small quantity gas from vaporizer to mix. As the computer controlling mix opening condition supplied a air as opening signal, the air and fuel became rarefied state. it knew that the engine didn't produce prpper power. Therefore, a car have to throughtly inspect not in order to arise the failure symptoms.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.3
• /
• pp.91-98
• /
• 2017

The purpose of this study is to provide a design and operation technical guideline for meeting the appropriate design criteria to bio-gasification facilities treating organic wastes. 9 anaerobic digestion facilities which is normally operated during the field survey and 14 livestock manure farms were selected for precision investigation. the physicochemical analysis was performed on the moisture and organic contents, nutrients composition (carbohydrate, fat, protein), volatile fatty acids (VFAs), and nitrogen, etc. Volatile solids (VS) of organic wastes brought into the bio-gasification facilities were 2.81 % (animal manure only) and 5.92 % (animal manure+food waste), respectively. Total solids (TS) reults of samples from livestock farms were 5.6 % in piglets and 11~13 % in other kinds of breeding pigs. The actual methane yield based on nutrients contents was estimated to $0.36Sm^3CH_4/kgVS$ which is equivalent to 72 % of theoretical methane yield value. The optimum mixing ratio depending on the effect of the combined bio-gasification was obtained through the continuous stirred-tank reactor (CSTR) which is operated at different mixing ratio of swine manure and food waste leachate. The range of swine manure and food waste leachate from 60:40 to 40:60 were adequate to the appropriate conditions of anaerobic digestion; less than 100 gTS/, more than alkalinity of 1 gCaCO3/L, C/N ratio 12.0~30.0, etc.

• Journal of Food Hygiene and Safety
• /
• v.30 no.2
• /
• pp.159-165
• /
• 2015

The aim of this study was to investigate microbiological contamination levels in the manufacturing company of ginseng products (white and red ginseng). Firstly, the contamination level for ginseng and each stage ginseng were 1.8~4.9 log CFU/g (total bacteria), 1.2~3.0 log CFU/g (coliform), 0.8~4.1 log CFU/g (fungi). However, only Bacillus cereus among pathogenic bacteria was detected from a few sample. The contamination of total bacteria tended to decrease as ginseng was being processing. Therefore, that of finished products (white and red ginseng) showed the lowest contamination level among each stage ginseng sample. That of fungi decreased steadily, although the contamination of fungi has tended to increase right after ginseng was steamed. Secondly, the contamination level for working tools and facilities were $1.7{\sim}4.7log\;CFU/cm^2$ (total bacteria), $0.4{\sim}4.0log\;CFU/cm^2$ (coliform), $0.9{\sim}4.2log\;CFU/cm^2$ (fungi). Especially, washing and peeling machines were higher contamination level. Finally, the contamination level of worker who washed and steamed ginseng was higher than worker who shaped, sorted and stored ginseng. Also, Staphylococus aureus was detected at 0.2~0.7 log CFU/hand on some wokers' hands. These results showed proper heating condition (temperature and time) and tidy manufacturing facility are the most important to avoid developing any microbiological problem of Ginseng Products.

• Journal of Life Science
• /
• v.23 no.3
• /
• pp.426-431
• /
• 2013

With the objective of developing a functional food source, we established optimal processing conditions for the larvae of Allomyrina dichotoma, which have been used in traditional medicine to treat hepatic disorders in Korea. Without suitable processing, the larvae are difficult to consume as a food because of their disgusting taste and smell; moreover, in this form they might be a potential microbial hazard. In this study, we investigated the effect of feeding material, sterilization, and powdering after freeze-drying on the food quality of the larvae of A. dichotoma and on cytotoxicity against Raw 264.7 cells. Three to five days feeding with the sawdust from discarded oak-trees is sufficient for the breeding process. The sawdust was sterilized by vapor for five minutes. Sterilization of the larvae at a high temperature ($115^{\circ}C$ for 5 min, 0.9 $kgf/cm^2$) is necessary to eliminate pathogenic bacteria and fungi. The results of the cytotoxicity assay showed no toxicity in the prepared extract from larvae of A. dichotoma. In addition, to prepare the larvae for human consumption, various feeds were used and the smell, color, and taste were evaluated. Our results suggested that larvae of A. dichotoma could be developed as food source when a suitable processing method is established.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.37 no.1
• /
• pp.1-11
• /
• 2019

This study was conducted to analyze the conservation status by diagnostical methology for the front wall of Jungjeongdang area of Dodong-Seowon. The study was carried out as photogrammetry and mapping - investigation of materials and conservation status - analysis and evaluation of conservation status. The results are as follows. First, in the case of photogrammetry, each photograph was took in superposition, and the distortions of the photographs were corrected and synthesized. Based on this, actual survey drawings of the wall were prepared. Second, in case of material and conservation status, the wall is in the form of Wapyeondam and the material of the head part are tile, mud and lime, and the material of the body part are mud and tile. The mud was mixed with gravel, sand and straw. At the base part, amorphous natural stones and mud were used. The remarkable damage that appears on the wall is erosion of the base part, and some disintegration appears in the body part. There is a biological patina on the head and the base, and vegetation such as lichen is concentrated on the partial body. There was superficial deposit in the head part, and some tiles were broken or lost. Deep fissures are intensively located in some part of the eastern wall. Third, in the case of analysis and evaluation of the conservation status, it is considered that by the erosion of the foundation part and the disintegration of the body part, there is a possibility that physical damage will continue to be applied to the wall, so immediate action is necessary. The distribution of biological patina and vegetation does not appear to cause great problems in the wall, but it is necessary to reduce it in view of aesthetic problems. A cracked or missing tile would need to be replaced, and deep cracks in the eastern wall appear to have been caused by subsidence, and reinforcement of the underground is necessary to prevent further damage.

• Korean Journal of Heritage: History & Science
• /
• v.55 no.1
• /
• pp.305-321
• /
• 2022

The stone chamber tomb in Eungpyeong-ri, Buyeo, is a joint tomb that contains the bodies of two individuals. This paper investigates the relationship between the buried persons and the characteristics of the stone chamber tomb. Based on the geographical location, relics, and the excavated human bones, it was determined that the tomb was built during the Sabi Period of the Baekje Dynasty and that the buried individuals were most probably residents of high stature or government officials. To study the excavated bones, the remains were carefully collected and conservation was carried out. Before collecting samples from the human bones for the analytical research, the results of near-infrared analysis were used to collect the samples for the isotope analysis and DNA analysis. The most important issue when handling the excavation site was the reinforcing agent and the concentration of the agent used. In situations like this, Paraloid B-72 is the most suitable agent. When the shape of human bones was difficult to distinguish from the soil, conservation was performed using X-ray and CT imaging data. The same chemical used for the reinforcement of the site was used to complete a minimum level of conservation to the surface areas where the conservation treatment of removing foreign substances, the reinforcement areas, and bonded areas were carried out. The collagen yield from the sample obtained at selected position was 3.8% to 6.1%. The results of analyzing the stable isotopes of carbon and nitrogen found in the extracted collagen showed that the stable isotope ratios came out to δ¹³C -18.3‰±0.1‰, -19.0‰±0.1‰ for EBW and δ¹⁵N 10.7‰±0.5‰, 10.6‰±0.1‰ for EBE. It is believed the two individuals consumed small amounts of minor cereals, mainly from C₃ plants, and protein was obtained from eating terrestrial animals. What's more, the deviations in data obtained from the two individuals were so small that it could be inferred that the individuals ate similar foods. Considering the preservation state of the sample, amplifying DNA for the DNA analysis would have been very difficult since the amount of surviving DNA was so deficient. For DNA analysis, it is anticipated that the results could be derived by applying improved extraction methods that will be developed in the future. In this research, any association between scientific analysis(DNA and stable isotope ratio) and near-infrared spectroscopy was difficult to establish. Further research is needed on the utilization of near-infrared analysis for gathering samples from human bones.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.11
• /
• pp.1757-1765
• /
• 2014

The objective of this study was to explore hygiene issues by analyzing the importance and performance of personal and school hygiene in school foodservices. Questionnaires were administered to 634 students (10 high schools) in the Busan area. Exactly 29% of respondents had received hygiene education. The average score of importance of students' personal foodservice hygiene was 3.81/5.00, and the performance score was 3.48/5.00. The same scores for school foodservice hygiene were 4.37/5.00 and 3.67/5.00, respectively. Regarding importance and performance of personal foodservice hygiene, students who had received hygiene education showed significantly (P<0.01) higher scores than those without prior education. In terms of importance of school foodservice hygiene, students who had received hygiene education showed significantly higher scores for environment hygiene (P<0.05) and equipment hygiene (P<0.05). Additionally, among grid analysis in personal foodservice hygiene, the areas of high importance and low performance included 'washing hands before the meal', 'using a designated cup for the water purifier', and 'keeping clean around the leftover container'. As for school foodservice hygiene, the same area was 'cleanliness of tray'. These findings suggest that hygiene education needs to be extended to more students, and for school foodservice hygiene, a cleaner environment should be created using equipment hygiene management, including emphasis on ensuring cleanliness of tray.

• Journal of dental hygiene science
• /
• v.7 no.1
• /
• pp.13-20
• /
• 2007

This study is aimed at providing basic data for measures to prevent dental hygienists who are highly exposed to hepatitis-B virus due to their characteristic working conditions from being infected of it. In order to determine their perception and the extent of their exposure to the risk of infection with hepatitis-B virus, a survey was conducted with questionnaires distributed to 354 dental hygienists who are working at dental offices in Seoul. Gyeongi and Jeolla provincial areas. From the survey, following conclusions could be drawn: 1. Sixty three point seven to 100 percent of them are found to have been vaccinated against hepatitis-B virus as is generally expected from their working environment. 2. Their general characters are found to be statistically significant in terms of vaccinating point of time among those who have been vaccinated. Most respondents are either vaccinated one year or 5 years ago. The completion of 3 requested vaccinations lies in the level of 64.3%~100% depending on the general characters. By age, the best result comes from the age group of 25~29, followed by the groups older than 30 and 20-24 in order (p < 0.05). Formation of antibody belongs to the level of 45%~100% generally. But statistically significant of them is the extremely unhealthy state with 100%, followed by normal, generally healthy, very healthy and not healthy in sequence (p < 0.05). 3. In terms of family's clinical history, it is known that the older (p < 0.01), the more unhealthy (p < 0.01) and the married (p < 0.01), the more possibility of having anamnesis of hepatitis-B virus infection. 4. The level of knowledge about Hepatitis-B virus is shown to be in the extent of 4.39~5.01 out of maximum 8 points in general terms. 5. It is revealed that there are high chances for dental hygienists to get spattered with body matters of patients like blood or sputum on their faces in general characters (87.%~100%). 6. A high rate (75%~100%) of respondents has experienced being shot by needles. The older(p < 0.05) and the longer(p < 0.05) their career, the higher the rate becomes.