• Journal of Technologic Dentistry
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• v.22 no.1
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• pp.89-112
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• 2000

Although dental laboratory technicians are prone to be exposed to various work-related health hazardous materials such as dusts, chemicals, etc., the prevalence and nature of work-related health problems of them have not been a matter of great concern in the field of occupational health service in Korea. The purpose of the present investigation was to describe a collected profile of subjective health symptoms and their attributable factors in Korean dental laboratory technicians. A questionnaire listing five groups of health symptoms and five health symptom-related factors was mailed to randomly selected 1,900 dental laboratory technicians. Among them, 1,344 dental laboratory technicians filled out the questionnaires and returnde them. Five groups of health symptoms included musculoskeletal symptom, dermal symptoms, respiratory symptoms, eys symptoms, and ear symptoms. Five health symptom-related factors were occupational environment-related health risk factors, work history, health related habits and status, use of personal protective equipment and general characteristics. Detailed parameters of health risk factors were work posture, vibration, and chemical or physical hazards such as dust, fume, vapor, solvent, light, and noise for occupational environment-related factors; work place, area, number of employees, work hours, career, work part, and work load for work history; Broca's index, hours of sleep, eating, smoking, alcohol, exercise, health examination, and self assessed health status for health habits and status; face masks, goggles, and so on for use of personal protective equipment, and; age, sex, marital status, and education for general characteristics. Before the start of main survey, a pilot survey was carried out for validity and reliability tests of the questionnaire. All the data obtained were coded and analyzed with PC/SAS 6.12 program. The prevalence of health symptoms was the highest in musculoskelton (87.3%), and followde by eyes (78.9%), respiratory organs (64.3%), ears (57.8%), and skin (52.2%) in descending order. Statistically significant risk factors by multiple logistic regression analyses were sex, health examination, self assessed health status, and hand/finger posture in musculoskeletal symptoms; sex, self assessed health status, career, acid gas, and hand contact with resin mixture in deraml symptoms; Broka's smoking, exercise, self assessed health status, and face mask in respiratory symptoms; sex, hours of sleep, self assessed health status, work hours, work load, plaster dust, inadequate lighting, and goggle in eys symptoms, and eating, smoking, self assessed health status, and work load in ear symptoms. With the above considerations in mind, prevalence of subjective symptoms among Korean dental laboratory technicians was relatively high, and they were attributable to most of the occupational environment-related factors, work history, use of personal protective equipment, health habits and status, and general characteristics. Particularly, it is suggested that health promotion programs for promoting self- assessed health status and smoking cessation, preventive measures for protection of the female technicians’health, and reducing work load be necessary, since those factors were associated with more than one subjective symptom.

• 한국해양학회지
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• v.30 no.4
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• pp.237-249
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• 1995

To understand the cross-sectional structures of temperature, salinity and current across the Korea Strait, field measurements were carried out for the period of May 2 to 20, 1994. Using the R/V Tam Yang, detailed CTD profiles and ADCP records were obtained and used to examine the mean and variability field on two time scales (15 days and 25 hours). A sharp coastal front in the middle of the Korea Strait exists across which two different water masses, i.e., warm and saline water in the eastern side and cold and less saline water in the western side are neighboring. We observed highly variable field of T and S apparently caused by the westward movement of warm and saline water mass. Short-term fluctuations of T and S in the middle layer are remarkable and their importance was analysed as the first Eigen mode accounting for more than 50% of total variances. The currents in th Korea Strait are strongly influenced by tidal currents with spring and neap variation whose maximum speed ranges 80-90 and 60-70 cm/s respectively near the central portion of the channel. Strong southward tidal current could even mask the Tsushima Current completely. Results of harmonic analysis show that the magnitudes of semidiurnal, diurnal and mean components of currents are comparable to each other at spring and neap tide conditions. The volume transport across the western channel of the Korea Strait were estimated to be 2.1 Sv at neap tide condition and 3.4 Sv at spring tide condition.

• Korean Journal of Veterinary Service
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• v.38 no.4
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• pp.241-248
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• 2015

This study was aimed to investigate factors that affected the status of wearing personal protective equipment (PPE) for handling poultry carcasses with potential exposure to virulent avian infectious agents. A large outbreak of high pathogenic avian influenza (HPAI) occurred in South Korea in 2014. Many public officers participated for euthanizing and handling livestock carcass. However, several safety issues with using PPE were revealed. Therefore, a questionnaire survey was conducted for 340 people who participated euthanasia and carcass disposal in the place where HPAI mainly occurred in 2014. It was found that 31.8% of the respondents had ever taken off their protective equipment during operations because of its inconvenience. The most inconvenient PPE was goggles (54.6%), followed by mask (20.2%), latex gloves (11.6%), shoe covers (5.9%) and protective clothing (5.3%). The main complaints about this individual PPE was unclear sight, damp emitted toward eye, sweating, tearing easily and sweating, respectively. Considering such problems of PPE, new possible directions for improvement of gloves and goggles were suggested. With newly developed rubber coating fabric gloves and conventionally using latex and fabric gloves, H3N2 influenza virus transmission experiment was conducted. Rubber coating fabric gloves showed similar efficiency for blocking virus transmission with latex laboratory gloves and were not easily torn by sharp claws of chicken. In addition, air flow control safety eyewear was suggested to minimize moisture formation. The air flow control system efficiently suppressed moisture formation inside the goggles. Therefore our study will provide more specific directions about new PPE development for safety protection of actual wearers.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.63-68
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• 2010

The use of deodorizing plant products such as persimmon leaves, pine needles and fennel seeds to mask the characteristic odor of kimchi has been proposed. Therefore, in this study, the effect of deodorizing plants on kimchi fermentation and the profile of volatile flavor compounds was investigated. During sensory evaluation tests of sour and fermentation odors of kimchi, plant extract-added kimchi showed higher sensory scores than chopped plant-added kimchi. Additionally, kimchi containing pine needle extracts (0.3-0.6%) and fennel seed extracts (0.05-0.1%) showed higher sensory scores than untreated kimchi. In addition, pine needle extract and fennel seed extract had a significant influence on kimchi fermentation characteristics such as pH, total acidity and the concentration of lactic acid bacteria. The volatile flavor compounds of kimchi and deodorizing plant extracts were also analyzed using GC/MS and the correlation of volatile flavor compounds in kimchi, plant extracts and plant-added kimchi was examined. The results revealed that the sour and fermentation odors of kimchi were reduced using deodorizing plant extracts by changing the kimchi fermentation characteristics.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.280-282
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• 1999

A new disease on mask melon grown under plastic film houses was found in Namhae area in May of 1999. Gray to dark brown mold were grown on the surface of matured fruits and infected inside tissues were discolored and rotten. Basal part of the fruit and blossom-end were frequently infected and colonized by fungi. About 2.2% of matured fruits were infected in the surveyed plastic film houses. The causal organism was isolated from the lesion and identified as Botrytis cinerea. The conidia in mass were hyaline or gray, 1-celled, mostly ellipsoid or ovoid and sized $8.8{\sim}21.2{\times}6.5{\sim}13.1\;{\mu}m$. Hyaline or pigmented conidiophores were tall, slender and determinated and, sometimes branched irregularly in upper part. Enlarged or rounded apical cells bear conidial cluster and sized $18.4{\sim}81.1{\times}4.3{\sim}11.4\;{\mu}m$. Optimum temperature for mycelial growth was recorded at $15{\sim}25^{\circ}C$. This is the first report on gray mold of melon caused by Botrytis cineria in Korea.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.199-209
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• 2010

The purpose of this paper is to suggest fundamental data for finding problems and ways to improve Korean dental infection control studies through the classification of literature on dental infection control which have been conducted in Korea. The collection of literature was done via seven online database programs only for domestic literature. The date of first search was September 16-17th, 2009, and the final search was completed on December 20th, 2009. (1) From the examination of the frequency of research according to the publishing form by year, it is revealed that after 2006, dental infection control is being performed most vigorously, compared with 1980's when the studied on this area started. (2) According to the classification of research method by research design of original article among the literature, original articles were 45 studies, and the others were 20 studies. It was also found that in 45 studies of original article, there were 37 studies of survey research, and there were 8 studies which include microbiology examination. (3) On the analysis of the subject of each study, glob and mask using rate have gradually increased, and the frequency of pierced with sharp implement or needle have gradually decreased. Through this research, it can be observed roughly how the results depended on subject of each studies change. However, it may be restricted to generalize the results of this research, because there are lack of clear standard and literature evidence to assess the interrelationship between each study. Also, since there are shortage of research and studies in dental infection control, the research to examine the effects should be tried actively after the standards and precaution of dental infection control developed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.247-255
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• 2016

In order to select a strain that forms a Biocellulose (BC), strain producing acetic acid was selected from commercially available kombucha. Through SM broth it was confirmed that the strain is a gram negative bacteria in the form of rods having no motility through a phase contrast microscope. The result of phylogenetic inference analysis based on 16S rDNA sequence analysis for the identification of strains was most closely related to Gluconobacter uchimurae (G. uchimurae) and was named G. uchimurae GYS15 strain. The strain showed the highest degree of growth when cultured for 14 days under the conditions of pH 5 and $25^{\circ}C$. Moreover, it showed the highest degree of growth in a Glucose addition disaccharide as the optimum carbon source sucrose and fructose. Also, 0.5% NaCl, upon the addition of Malto extract, showed the highest degree of growth. Based on investigation by the optimum growth conditions to confirm the physical properties of BC obtained by culturing G. uchimurae GYS15 strains. The surface structure was observed through an scanning electron microscope (SEM) showed a high networks structure. It until $8.6{\pm}0.38$ times when the water holding capacity is re-absorbed and re-absorbed holding oil up to $6.6{\pm}0.51$ times confirmed. In conclusion, using these material properties, it was possible to confirm the possibility of a variety of cosmetic materials and mask pack materials.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.599-604
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• 2020

Since Corona 19, awareness about antibacterial bacteria has changed. Hand washing after going out became a necessity. Also, fogging occurs a lot on the glasses depending on the wearing of the mask. This problem has caused a lot of discomfort in our daily life and changed our perception of antibacterial and anti-fogging. Therefore, in this study, we studied whether mugwort extract is effective in preventing antibacterial and fogging. To obtain the mugwort extract, mugwort was dried, alcohol extracted, and freeze-dried. An antibacterial test was performed using a mixture of mugwort extract, zinc oxide and natural zeolite mixed in 3:7, and a fogging test was performed using mugwort extract and other mixtures. As a result, in the case of E. coli and K. pneumoniae, which were used as test strains in the antibacterial test, the bacteria were not cultured from the medium added with 1% mugwort extract, and the antibacterial activity against representative Gram-negative bacteria was confirmed. In the anti-fog test, a 10 wt% mixture of mugwort extract showed very good results in both the hot and cold parts. We expect the mugwort extract to be effective in antibacterial and anti-fogging, thus helping to overcome Corona 19.

• Journal of Korean society of Dental Hygiene
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• v.11 no.3
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• pp.301-311
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• 2011

Objectives : In order to identify the awareness of influenza A (H1N1) having currently high frequency and risk as an infectious disease, to find problems and to reflect them on curriculum improvements from students before/after clinical practices. Methods : The data was collected from 279 dental hygiene students of 1st and 2nd years at G health college university from December 6th 2010 to December 10th 2010. The questionnaire were consisted of awareness of influenza A (H1N1), preventive attitude, sociodemographic characteristics. Results : 1. 1st year was 51.6%, the case having dental experience was 51.2%, in the infection control training experience 'had' was 46.6%. In the route acquiring the information, the mass media was 70.6%, in obtained information, personal hygiene was 82.1%. In the impact on human body, 'great impact' was 58.1%. In terms of the most need for response and preparedness, vaccination was the highest, 67.4%. People who experienced influenza A (H1N1) were 10.7%. 2. Awareness of influenza A (H1N1) was 0.71 points, and treatment and spreading mechanism was 0.78 points, prevention was 0.63 points, causes and definition was 0.53 points. 3. In the attitude for infection prevention of influenza A (H1N1), 'washing hands before practice' was the highest, 0.99 points and 'wear the mask only in case of contact with patient within 1~2 meters upon occurrence of no aerosol' was the lowest, 0.72 points. 4. Awareness of influenza A (H1N1) according to sociodemographic characteristics showed the significant differences upon the impacts on systemic health (p<0.05). Preventive attitude didn't show a significant difference in grade, clinical experience, experience in infection control training, acquiring rmation routes, the possibility for occurrence, impact on systemic health, the most need for prevention, experience in influenza A (H1N1) (p>0.05). 5. The significantly correlated between awareness of influenza A (H1N1) and preventive attitude(p<0.01). Conclusions : Information and preventive attitude for influenza A (H1N1) as well as systematic training programs to identify actual affecting factors and to improve the practice are needed. Also government's institutional support is needed.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.48-57
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• 2020

MCU used in applications such as wireless chargers and USB type-C require MTP memory with a small cell size and a small additional process mask. Conventional double poly EEPROM cells are small in size, but additional processing masks of about 3 to 5 sheets are required, and FN tunneling type single poly EEPROM cells have a large cell size. In this paper, a 110nm MTP cell using a vertical PIP capacitor is proposed. The erase operation of the proposed MTP cell uses FN tunneling between FG and EG, and the program operation uses CHEI injection method, which reduces the MTP cell size to 1.09㎛2 by sharing the PW of the MTP cell array. Meanwhile, MTP memory IP required for applications such as USB type-C needs to operate over a wide voltage range of 2.5V to 5.5V. However, the pumping current of the VPP charge pump is the lowest when the VCC voltage is the minimum 2.5V, while the ripple voltage is large when the VCC voltage is 5.5V. Therefore, in this paper, the VPP ripple voltage is reduced to within 0.19V through SPICE simulation because the pumping current is suppressed to 474.6㎂ even when VCC is increased by controlling the number of charge pumps turned on by using the VCC detector circuit.