• The Journal of the Korean dental association
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• v.53 no.10
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• pp.743-750
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• 2015

Objectives: This study compared the mechanical efficacy of sonic activated and passive ultrasonic irrigation for removing intracanal medicament from a simulated root canal under controlled conditions. Materials and Methods: Thirty simulated root canal in resin blocks were randomly divided into 3-groups. The canals were enlarged using ProTaper files and K3XF (#30/0.06). After cleaning and drying, canals were filled with Calcipex. Overfilled materials were wiped out and measured their weight to the unit of 1/10mg. After one week storage in 100% humidity $37^{\circ}C$ temperature, canals were irrigated using 20mL of saline with one of following methods according to the designated groups (n = 10). For group-NI, 30-gauge nickel-titanium irrigation needle was used. During irrigation with every 5mL, needle was moved in-and-out with 4-mm amplitudes. EndoActivator and ultrasonic tip were used for group-EA and group-UT respectively for 20 seconds after every 5mL irrigation using needle. Then the weight was measured again to calculate the weight of residual remnants. The data were analyzed by one-way ANOVA and Duncan's post-hoc test at a significance level of 95%. Results: The weight of the residual medicaments were $3.62{\pm}0.81mg$, $2.84{\pm}0.28mg$, and $2.73{\pm}0.90mg$ for group-NI, -EA, and -UT, respectively. Group-EA and group-UT had no significant differences to remove intracanal medicament and left significantly less amount of paste than group-NI (p < 0.05). Conclusions: Under the controlled conditions of this study, the sonic activation and PUI have similar mechanical efficacy for removing intracanal medicament.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.4
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• pp.553-562
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• 2010

This survey investigates the conditions of summer working uniforms for contracted foodservice workers. The data were obtained from 67 workers through in-depth interviews (July 2005~October 2005). The results of study are as follows: The working environment changed to menu and cooking method (air temperature $28\sim37^{\circ}C$, humidity 72~86 %RH, radiant temperature $27\sim37^{\circ}C$, air velocity 0.14~0.37m/sec). They answered that the working environment has high temperatures, humidity, excessive noise, and liability to slide. The typical accidents were burns, cuts, slide, and ligament injuries in the workplace. Work duties consisted of cooking, serving food, washing, and cleaning up leftover food. All the employees carried out multi tasks. The primary working postures and motions were standing, crouching, and lifting. The female workers usually wore underwear (panty and brassiere), upper and lower work wear, aprons, waterproof-aprons, cotton-gloves, rubber-gloves, socks, and rubber-boots. The satisfaction of the uniform was relatively low for trousers and waterproof-aprons. The answer about the fit was generally "comfortable." They answered "back," "chest," and "head" were wet with perspiration during work. The uncomfortable parts were the crotch and neck. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly for ventilation and absorbency. In case of the colors of the working uniform, workers preferred white color for the upper part, and black color for the lower part.

• Journal of Korean society of Dental Hygiene
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• v.20 no.1
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• pp.53-62
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• 2020

Objectives: The purpose of the study was to analyze the association between dyslipidemia and periodontitis in Korean adults aged 30 and older. Methods: We examined 3,992 subjects participating in the 2015 Korean National Health and Nutrition Examination Survey. Periodontal status was evaluated using the community periodontal index (CPI). People with 3 or 4 CPI codes were classified as the periodontitis group. For statistical analyses, chi-square test and logistic multiple regression were used. Results: The prevalence of periodontitis was higher in men, people aged 70 and over, people whose income status was among the lower 25%, and people whose educational level was high school or lower (p<0.001). The prevalence of periodontitis was higher in people who brushed their teeth twice or less, those who did not use interdental cleaning devices, those who did not have a dental checkup in the last 12 months, and those who had not drunk or smoked (p<0.05). The prevalence of periodontitis was increased with individuals whose BMI was ≥25 kg/㎡, those whose glycated hemoglobin was ≥6.5%, and whose lipid levels were higher or lower than the normal range. In the logistic regression model, an increase in triglyceride was found to increase the prevalence of periodontitis (p<0.05). Conclusions: The study suggests that dyslipidemia, especially hypertriglyceridemia, is a predictor of periodontitis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1277-1282
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• 2011

Recently, many car drivers were damaged by gas station which support similar oil product and not quantitative gas. It were expected to increase above-mentioned damages. By using similar oil products, caused damage are working of lubrication in the fuel line, elf-cleaning function, the part of the early deterioration, impure accumulation in the fuel line, toxicity material in exhaust emissions and unidentified chemical reaction. To prevent these damages, proposed system use in-vehicle state data with OBD-II protocol, measure quantitative gas and similar oil. In this paper, there have implemented similar oil identification and quantitative gas system through OBD-II scanner to provide WiFi communcation by using WinCe development Board.

• Korean Institute of Interior Design Journal
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• v.27 no.1
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• pp.156-164
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• 2018

This study analyzed the characteristics of Physical Environment of existing free shuttle bus Interior centered on elderly people who frequently use free shuttle buses. The purpose of this study is to provide basic data that can be used for improvement of existing free shuttle buses. In the case of the old type, in terms of accessible design, the middle entrance is not normally opened except the wheelchair occupant, so that the entrance of the front wheel is always used. Therefore, most elderly people go to the back seat and travel distance is twice longer. In addition, many stairs caused frequent inconveniences for boarding. In the case of the new type, it is planned to be a low-floor type, and various types of safety rods and handles, pictograms for enhancing the information convenience are well-equipped, and the measured value of the overall design characteristic is high. However, in the case of mental stability, it was confirmed that the seat of the bus is colored with a cold color system and is in a different relationship with the warm color which can feel mental stability. Overall, both old and new shuttle buses lack audiovisual feedback on bus routes and route guidance in terms of Supportive design. Also, since the cleaning tools and other miscellaneous items were left in the room, it became an obstacle to space utilization in terms of adaptable design. In terms of safety, both shuttle buses did not come into view with fire extinguishers shaded by miscellaneous items. Therefore, immediate action is unlikely in case of emergency. This problem should be resolved quickly.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.173.1-173.1
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• 2011

The high fuel flexibility of gas turbine power system has boosted their use in a wide variety of applications. Recently, the demand for biogas generated from the digestion of organic wastes and sewage waste water as a fuel for gas turbines has increased. We investigated the performance of high pressure biogas compression system and operating conditions for supplying biogas. The total flow per minute of biogas from food waste water digestion tank is $54Nm^3$. The main type of biogas compression system is the reciprocating system and screw type system. The target of biogas mechanical data is the as belows; inlet pressure 0.045bar, supplying biogas temperature is $30{\sim}60^{\circ}C$, and final pressure is above the 25 bar. Also, inlet conditions of biogas consist of CH4 48.5%~83%, $H_2S$ Max. 500ppm, $NH_3$ Max. 1,500ppm and Siloxane 2.7~4.6ppm. The boosting Blower system raises a pressure from 0.045bar to 1bar before main compressor. The main system lay out of reciprocating consisits of compressor driver, filter, cooling system, blowdown vessel, control system and ESD(Emergency Shut Down) system. And an enclosure package needs to be installed for reducing noise up to 75dB. The system driver is the electronic motor of explosion proof type. Forthe compressor system reliable operation, the cleaning system something like particulate filter needs to be set up in the inlet of compressor and Coalescing Filter in the outlet of compressor. Particulate Filter has to be removed above $10{\mu}m$ size of the particles in biogas. The coalescing filter(Micofine Borosilicate Glass Fibers Filter treated phenol acid) also removes moisture and oil of above $0.3{\mu}m$ to be involved in high pressure biogas up to 90%~98%.

• The Plant Pathology Journal
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• v.36 no.5
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• pp.468-475
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• 2020

Malva vein clearing virus (MVCV) is a member of the Potyvirus species, and has a negative impact on the aesthetic development of Alcea rosea. It was first reported in Germany in 1957, but its complete genome sequence data are still scarce. In the present work, A. rosea leaves with vein-clearing and mosaic symptoms were sampled and analyzed with small RNA deep sequencing. By denovo assembly the raw sequences of virus-derived small interfering RNAs (vsiRs) and whole genome amplification of malva vein cleaning virus SX strain (MVCV-SX) by specific primers targeting identified contig gaps, the full-length genome sequences (9,645 nucleotides) of MVCV-SX were characterized, constituting of an open reading frame that is long enough to encode 3,096 amino acids. Phylogenetic analysis showed that MVCV-SX was clustered with euphorbia ringspot virus and yam mosaic virus. Further analyses of the vsiR profiles revealed that the most abundant MVCV-vsiRs were between 21 and 22 nucleotides in length and a strong bias was found for "A" and "U" at the 5′-terminal residue. The results of polarity assessment indicated that the amount of sense strand was almost equal to that of the antisense strand in MVCV-vsiRs, and the main hot-spot region in MVCV-SX genome was found at cylindrical inclusion. In conclusion, our findings could provide new insights into the RNA silencing-mediated host defence mechanism in A. rosea infected with MVCV-SX, and offer a basis for the prevention and treatment of this virus disease.

• Korean Journal of Community Nutrition
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• v.7 no.3
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• pp.361-372
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• 2002

The purpose of this study was to investigate the operation and management systems of the school food services in Korea and to provide useful data for improving the quality of the school food services. This study was conducted in school food service operations nationwide using a written questionnaire. The questionnaires were mailed to the dieticians of three types of school food service systems-conventional, commissary, and joint-management. Of the 660 schools that participated in this study, the responses from 212 conventional system, 212 commissary system and 200 joint-management system services were selected for analysis. Statistical analysis was performed utilizing the SAS/Win 6.12 program so as the provide a descriptive statistics. The main results of this study can be summarized as follows: The average number of meals served per day was 1014, 738 and 695 in the conventional food service, the commissary food service and the joint-management flood service systems, respectively. Over half (58.9%) of food service facilities were utilizing computer programs for their operations. Most of the commissary flood service systems (52.4%) had a satellite school and served a maximum of 2000 meals per day. In most of the joint-management food service systems (87.1%), the number of food service schools managed was two and a maximum of 3330 meals were sewed. Only one dietician was posted irrespective of the school food service system. The mean hours of work by the dietician per day was 8.9, 8.6 and 8.6 in the conventional food service, the commissary flood service and the joint-management food service systems, respectively. The principal work functions of cook personnel were cooking and cleaning.

• Korean Journal of Human Ecology
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• v.20 no.3
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• pp.637-649
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• 2011

The purpose of this study was to analyze employees' practice levels and knowledge of sanitation at school foodservice operations, to examine the sanitation conditions of current school foodservice, and to suggest an effective sanitary training program. A questionnaire survey was conducted on a total of 578 subjects and 501 reponses were made available for this study. The collected data was analyzed using SPSS of windows. The main results can be summarized as follows: Training through handouts was the most effective (53.2%) and lack of time caused by overwork (57.1%) made the practice of sanitation training difficult. The degree of employees' perceptions of the necessity of sanitary training programs was marked at 4.18 points. According to the foodservice employees' evaluation about the knowledge of sanitation concerning the sanitary training program contents, the area of environmental sanitation (96.3%) was the highest while food poisoning control (72.9%) was lowest. Foodservice employees' practice levels was ranked above 4 points (out of 5 points) in 9 areas. Practice levels of cleaning and disinfection management were highest while that of safety management was lowest. About the food service employees' practice levels of sanitation, the degree of practice and the application of knowledge was 4.39 points. There was a significantly positive correlation between the practice level of sanitation and sanitation knowledge(p<.01). Thus, educational material needs to be standardized in order to improve employees' sanitation practice level.

• Membrane and Water Treatment
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• v.8 no.3
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• pp.279-292
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• 2017

This study was aimed at ultrafiltration (UF) as a pretreatment before reverse osmosis (RO) within the scheme of hybrid reverse osmosis-multistage flush (RO-MSF) desalination. Seawater at elevated temperature (after MSF heat-exchangers) was used as a feed in this process. The pretreatment system was represented as a set of functionally-linked technological segments such as: UF filtration, backwashing, chemical- enhanced backwashing, cleaning, waste disposal, etc. The process represents the sequences of operating cycles. The cycle, in turn, consists of the following unit operations: filtration, backwashing and chemical-enhanced backwashing (CEB). Quantitative assessment was based on the following indicators: normalized permeability, transmembrane pressure, specific energy and water consumption, specific waste generation. UF pre-treatment is accompanied by the following waste streams: $W1=1.19{\times}10$ power of $-2m^3$ (disposed NaOCl with 0.0044% wt.)/$m^3$ (filtrate); $W2=5.95{\times}10$ power of $-3m^3$ (disposed $H_2SO_4$ with 0.052% wt.)/$m^3$(filtrate); $W3=7.26{\times}10$ power of $-2m^3$ (disposed sea water)/$m^3$ (filtrate). Specific energy consumption is $1.11{\times}10$ power of $-1kWh/m^3$ (filtrate). The indicators evaluated over the cycles with conventional (non-chemical) backwashing were compared with the cycles accompanied by CEB. A positive impact of CEB on performance indicators was demonstrated namely: normalized UF resistance remains unchanged within the regime accompanied by CEB, whereas the lack of CEB results in 30% of its growth. Those quantitative indicators can be incorporated into the target function for solving different optimization problems. They can be used in the software for optimisation of operating regimes or in the synthesis of optimal flow- diagram. The cycle characteristics, process parameters and water quality data are attached.