• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.299-304
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• 2012

Purpose: The aim of this study is to investigate the effect of different experience level and different light source on shade selection ability comparing prosthodontist group and dental student group under 4,000 K and 5,500 K light. Materials and methods: After color difference of Vitapan 3D-master shade guides was measured, 3 sets of 5 shade tabs were selected with similar value but have different chroma (set a, b, c). Also 3 sets of 5 shade tabs were selected with similar chroma but have different values (set d, e, f). Under 4,000 K and 5,500 K light sources, ten prosthodontists and ten dental students were allowed to match in one set of 5 tabs the same shade tab with the tab which was originally selected in the other set of 5 tabs. Color differences of original tab and matched tab were measured by spectrophotometer and the shade selection ability was evaluated with those data. Evaluation of color difference value was performed in regard to different light conditions and different level of experience, followed by t-test with 95% confidence interval. Results: Color difference values under 4,000 K and 5,500 K light source were $1.62{\pm}2.0$, and $1.33{\pm}1.7$ respectively. In addition, color difference values of prosthodontist group and dental student group were $1.34{\pm}1.7$, and $1.61{\pm}2.0$ respectively. Difference of shade selection ability was not found under either different light sources (P=.398), or different experience level (P=.221). Conclusion: Level of experience did not affect on the shade selection ability when prosthodontists and dental students matched the shades with the same shade tab under the same light source.

• Journal of Food Hygiene and Safety
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• v.37 no.6
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• pp.400-410
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• 2022

This study was performed to analyze the microbial contamination levels of three non-heated rice cake manufacturers in terms of seasonal manufacturing process and to investigate the effects of summertime soaking on contamination levels and temperature-controlled soaking in water on reduction in microbial levels. The total aerobic bacteria (TAB) ranged from 2.69 log CFU/g to 5.08 log CFU/g in the produce, but the microbial contamination increased sharply during soaking. The levels of TAB and coliforms during summer soaking were 7.01 and 3.96 log CFU/g, respectively, and this was significantly higher than those in other seasons. The contamination level was high in the subsequent freezing, with the TAB level (6.24 log CFU/g) exceeding the legal standard. The temperature of soaking water in summer increased from 19.1℃ to 26.8℃ after 12 h of soaking. The microbial contamination was significantly high commensurate with increased soaking time, and the TAB level in the frozen process exceeded the legal standard from 9 h of soaking. The use of ice packs to prevent the increase in temperature of the soaking water in summer resulted in maintenance of temperature at 20.1℃ for up to 12 h. The average TAB value in the freezing process was 4.42 log CFU/g after 12 h of soaking, and this is 1.77 log CFU/g lower than that before. Based on these results, it was determined that controlling the soaking time and water temperature are essential for the production of a safe unheated frozen rice cake. The safety of the HACCP system could be established by applying these preventive management standards.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.682-691
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• 2020

Careful cleaning and disinfection of pigpens is essential to prevent disease spread and avoid the resultant economic losses. Hygiene in pigpens is generally evaluated by visual monitoring supplemented with bacteriological monitoring, which includes counting the total aerobic bacteria (TAB) and/or fecal indicator bacteria (FIB). However, these methods present drawbacks such as time and labor requirements. As adenosine triphosphate (ATP) is ubiquitous in all living organisms including microorganisms, this study aimed to directly compare the results of microbial assessment and ATP quantification, and to suggest possible detailed application methods of the ATP test for hygiene evaluation in pigpens of a farrowing unit. Before and after standard cleaning procedures, samples were collected from the floor corner, floor center, and feeding trough of four pigpens at different time points. No FIB were detected and both the TAB and ATP levels were significantly decreased in the floor center area after cleaning. FIB were continuously detected after cleaning and disinfection of the floor corners, and there was no significant ATP level reduction. The feeding trough did not show any significant difference in these values before and after cleaning, indicating insufficient cleaning of this area. The levels of TAB and ATP after cleaning were significantly correlated and the average ATP value was significantly lower in the absence of FIB than in their presence. In the absence of standard references, a more thorough hygiene management could be achieved evenly by supplementing cleaning or disinfection based on the lowest ATP results obtained at the cleanest test site, which in the present study was the floor center. Overall, these results indicate that the on-farm ATP test can be used to determine the cleanliness status, in addition to visual inspection, as an alternative to laboratory culture-based testing for the presence of microorganisms.

• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.309-314
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• 2015

The purpose of this study is to monitor the microbial contamination of ice collected from food stores or restaurants from all over the country. From the ice collected on a regional basis, it was observed that the average number of total aerobic bacteria (TAB) of samples from Seoul was the highest, showing 2.31 log CFU/g, while that of samples from Jeolla-do was the lowest, showing 1.83 log CFU/g. The food-borne pathogens (Staphylococcus aureus, Listeria monocytogenes) were not detected from the ice. Also the average number of TAB of packaged ice (commercial ice) was 0.45 log CFU/g lower than that of ice from ice-making machine. Among three types of stores (the bakery, the dessert store and the beverage store), ice from dessert store showed the highest number of TAB (2.37 log CFU/g). This study suggests that the hygienic management of the ice from the stores is necessary. Therefore, to ensure the hygienic management of ice, not only the ice-making machine should be sanitized on a regular basis but also a thorough individual hygiene is required from food manufacturing workers.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.4
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• pp.36-47
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• 2009

Microbial and related biochemical mass of composts are important for optimization of its process and end-products. This study was carried out to assess the specific microbial and related biochemical mass which could be used as an indicator for compost maturity during composting stages. The samples from five compost plants were collected at three stages (Initial, Thermophilic and Mature) and analyzed for total aerobic bacteria (TAB), Coliforms, Escherichia coli, Actinomycetes and fungi. Significantly, the coliforms and E.coli counts decreased during the thermophilic stage and were completely eliminated during mature stage. However, the other microbial mass were completely eliminated during mature stage. Which disclosed that Coliforms and E.coli communities can be used as compost maturity indicator. Interestingly, the microbial biomass carbon and nitrogen ratio (MBC/MBN) were decreased a little during the thermophilic stage due to the decreasing number of coliforms, Ecoli and fungi, while the ratio increased during the mature stage due to increasing fungal and aerobic bacterial counts. In addition the heavy metals were shown strong negative correlation with Actenomycetes. This study provides insight to the evaluation of compost maturity as well as the quality by the metal-microbial interactions.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.60-67
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• 2020

This study determined the microbial contamination levels of hot pepper at harvest, sorting, and distribution stages to suggest a way of reducing the microbial contamination of hot peppers by changing work gloves used throughout these processes. According to the monitoring results, the contamination levels of total aerobic bacteria (TAB) were found in the following order: soil (5.3±0.9 log CFU/g), hot pepper (4.2±0.9 log CFU/g), gloves (4.2±0.6 log CFU/g), baskets (4.1±0.7 log CFU/ g), clippers (3.9±0.6 log CFU/ g) and water (3.2±1.1 log CFU/g) at harvest stage. The contamination level of coliforms were found in the following order: soil (2.2±0.9 log CFU/g), hot pepper (2.2±0.3 log CFU/g), gloves (2.1±0.6 log CFU/g), clippers (2.0±0.21 log CFU/ g) and baskets (1.9±1.1 log CFU/ g) at harvest stage. TAB on hot pepper at the harvest stage was reduced from 4.2±0.9 log CFU/g to cold storage 3.8±0.2 log CFU/g and room temperature storage 2.6±0.3 log CFU/g, respectively. By the replacement of work gloves and lower distribution temperature, TAB levels of the peppers were significantly reduced compared to those without replacement and distributed at room temperature. In addition, the utilization of plasma was effective on reducing microbial contamination of hot pepper. These results demonstrated that appropriate replacement of gloves at the harvest stages, using plasma in the distribution stage, and refrigerated distribution conditions, which are simple and easy to practice in the field, are effective to reduce microbial contamination on hot peppers.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.99-109
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• 2009

This study was performed to evaluate the effect of increasing instream flow at Nonsancheon stream of Nonsan city by securing water storages in upstream reservoirs; Ge-ryong, Gyoung-cheon, Dae-dun, and Tab-jeong. The paralleled and cascaded upstream reservoir operations for 8 storage securing scenarios were considered to simulate daily streamflows at Nonsan station. Using Tab-jeong reservoir water storage, the DAWAST model's parameters were determined, and the verified result showed Nash-Schcliffe's coefficient of 0.666. Instream flows were analyzed to supply maximum $59.85Mm^3$ on an annually average from upstream reservoir storage securing scenarios. The storage securing set of 2 m heightened Ge-ryong, 5 m Dae-dun, and 1 m Tab-jeong showed that the additional secured water storages were $17.132Mm^3$ and instream flow at Nonsan station was increased to $2.183m^3/s$, 2 times of present condition.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.6
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• pp.686-695
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• 1988

An algorithm and a computer program were developed for the operational simulation of office building cooling system. Using this computer program, the following results were obtained. ${\bullet}$ There is a critical number of coil rows in AHU with which the cooling system can be operated in maximum efficiency. ${\bullet}$ Energy conservation can be achieved in an office building through TAB(Testing Adjusting and Balancing) of zone air volumes.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.84.5-84
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• 2002

In order to be a stand-alone structure, a biped robot should be designed of the effective mechanic structure and the smaller hardware system. This paper shows the design methodology of a biped robot controller using FPGA(Field Programmable Gate Array). A hardware system consists of DSP(Digital Signal Processor) as the main CPU and FPGA as the motor controller...

• Electronics and Telecommunications Trends
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• v.4 no.1
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• pp.16-34
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• 1989

반도체 산업에서 패키지는 반도체 재료 및 공정 분야와 같은 거대한 시장을 형성하는 중요한 분야이다. 소자가 다양해짐에따라 패키지의 형태도 다양해졌고 이에 따르는 패키지 재료 및 공정 분야가 특히 중요한 연구과제로 부상하고 있다. 현재 패키지 형태는 DIP형이 주류를 이루고 있으나 점차 CC형으로 변화 될 전망이며 탑재 기술면에서는 TAB 형태로 발전되는 추세를 보이고 있다. 국내 기술은 자체기술 개발 및 기술제휴를 통하여 시장이 점차 복잡화 다양화 하는 상황에서 기술개발에 전력을 쏟아 리드 프레임의 단일화, 도금기술의 향상으로 가격 절감을 통한 경쟁력 향상을 꾀하고 있다.