• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.25-33
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• 1998

In this paper, we describe a single-gate MESFET mixer at PCS(Personal Communication Service) frequency band. The PCS frequency band is 1965~2025 MHz in FR and 140 MHz in IF irrespectly. The design of the mixer was executed by microwave simulator, EEsof Libra. The matching network is consisted of rectangular inductor, MIM capacitor and open stub. The ma- nufacture work was accomplished by the micro-pen and wedge-bonder. The mixer showed $6.69\pm0.65$ dB of conversion gain, $-14.9\pm3.5$dB of RF reflection coefficient and 57.83 dB of LO/IF isolation at 10 dBm of LO power when LO frequency is 1855 MHz. When this mixer is used at PCS terminal, IF-amplifier which compensates the conversion loss of diode mixer may be omitted.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.272-279
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• 2018

The high pressure processing (HPP) is a technology which can preserve the quality of foods, such as the fresh taste, incense, texture, vitamin content, and so on, by minimizing the heating process. It does so by applying an instantaneous and uniform pressure that is the same as the water pressure that is 60 km deep in the sea. HPP is a technology that can inhibit food poisoning and spoilage caused by microorganisms and is currently an actively studied area. In this study, we investigated the effects of a high pressure treatment (0, 4, 6 min) on sliced ham, which is a typical meat product, at 600 MP a were tested for their effect on freshness. Moisture contents varied from 48 to 69%, salinity varied from 1.07 to 1.11%, and the pH decreased from 6.4~6.5 to 6.1~5.15. However, there was no difference between the control and treatment groups. General bacteria stored at $20^{\circ}C$ after hyper-pressure treatment were found to have no significant microorganisms in all groups until 4 weeks. but exceeded $10^5$ in control group and HPP 6 min treatment group from 5 weeks, At week 7, it was found to exceed $10^6$. The results indicate it was not possible to ingest food in the 4-and 6 minute treatment groups. Coliform was not observed in all groups despite observing for a total of 7 weeks at $20^{\circ}C$ weight test. VBN, a method used to determine the protein freshness of meat, showed a VBN value of less than 1 mg% until the fourth week and a value of 1 to 2 mg% after 5 weeks. The TBA was used as an index of the degree of fat acidosis in the meat tissues. The results showed it was below 0.18 mgMA / kg until the end of 7 weeks; this value was within the range for fresh meat, and there was no difference in treatment group. In this experiment, deformation of the packaging material did not occur and no swelling occurred due to the generation of gas. It is believed that the basic preservation effect was achieved only by blocking with the air due to the close contact of the packaging material.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.E2
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• pp.69-77
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• 2006

Combined gas and aerosol measurements at a downwind area of the volcanic plume would be essential for helping to access the impact of the volcanic eruption on the local ecosystem and residents. An intensive and the fine time resolution measurement of $SO_2$, sulfate and PM2.5 was made to estimate their distribution in the Kanto area of Japan during the Miyakejima volcanic eruption period. In Tokyo, the 1 hr average $SO_2$ concentration observed before the eruption was 23.9 ppbv, while that of after eruption was 140.4 ppbv. In the Saitama Prefecture, the average concentration of $SO_2$ marked in the present study was two times higher than the average before the volcanic eruption. The PM2.5 mass concentrations in Sitama ranged from 3.8 to $136{\mu}g\;m^{-3}$. Sulfate accounts for $4.4{\sim}39.6%$ of PM2.5 in Sitama. The good correlationship between the concentrations of $SO_2$ and sulfate was obtained. The results of the VAFTAD and HYSPLIT models indicate that $SO_2$, sulfate, and PM2.5 measured in the present study would be expected to be significantly affected by the Miyakejima volcanic plume.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.1-5
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• 2012

This study was conducted to elucidate the cause of micro-cracking in the exocarp of 'Jinmi' peach (Prunus persica). through the microscopic observation of fruit skin development in 4 varieties such as 'Jinmi', 'Kanoiwa Hakuto', 'Kawanakajima Hakuto', and 'Yumyeong'. Micro-cracking was noted in 59.1% of 'Jinmi', 30.6% of 'Kanoiwa Hakuto', 21.5% 'Kawanakajima Hakuto' and 6.4% of 'Yumyeong', respectively. The development of intercellular spaces, which increased rapidly with the fruit development, was easily observed at 69 days after full bloom. Histological studies revealed that the number of outer epiderm cell layers of 'Jinmi' was smaller than that of the other three cultivars, and thinner than the 'Kawanakajima Hakuto' and 'Yumyeong'. Moreover, 'Jinmi' exhibited smaller and flatter shapes in the sub-epidermal cell layer than those of the 'Kawanakajima Hakuto' and 'Yumyeong' at harvest season. Therefore, these results suggest that micro-cracking of 'Jinmi' fruit skin was due to poor-developed outer epidermis and well-developed intercellular spaces just under exocarp as compared with other varieties.

• Journal of Acupuncture Research
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• v.22 no.6
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• pp.135-140
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• 2005

Objectives : There have been several studies about the quality of acupuncture needle tip recently. We have investigated the condition of the tip of the acupuncture needles in the last studies. In the former studies, we discovered the metallic scuff, lumps and irregularities of the acupuncture needle tips under the microscope. But, no information was available on those foreign materials' identity. Methods : We have selected 200 needles of 1000 pieces from several companies by randomized methods. And we observed the tip of the 6 needles selected finally at ${\times}1000\;or\;{\times}3000$ magnification and analyzed the components of the metallic scuff, lumps and irregularities of the needle tips with a SEM-EDX analyser. Results : We found that the identity of the metallic scuff, lumps and irregularities of the needle tips were metallic materials and silicon. For example, A point was composed of Fe(69.78%), Cr(17.71%), Ni(8.11%), Zn(2.04%), Si(1.23%), Mn(1.12%), and B point was composed of Si(66.40%), Fe(26.76%), Cr(6.84%). Conclusion : The results of this study confirm that there is a real possibility of the remaining of metallic materials and silicon in body of patient, after acupuncture treatment. Therefore, it is necessary to intensify our efforts to make needles of good quality and to concentrate on manufacturing process of acupuncture needles completely to be free from danger in acupuncture treatment.

• Journal of Environmental Health Sciences
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• v.31 no.6
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• pp.475-482
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• 2005

This study aimed to determine the fluoride intakes in 120 preschool children aged 3 to 6 residing in Jumunjin (community water fluoridation area) and Gangneung (non-fluoridation area). The parents were asked to collect 24-hour urine samples and to duplicate the samples of all the diets that their children ingested in the day of urine collection. The acid-diffusible fluoride in the food and non-carbonate beverages were isolated by the acid-diffusion technique and then measured with a fluoride electrode. The fluoride in carbonate beverages, drinking waters and urine samples were measured directly with a fluoride electrode. The geometric mean (geometric standard deviation) of daily fluoride intakes from all kinds of diet was 5.99 (2.27) $\mu$g/kg/day in the children in Gangneung and that of the children in Jumunjin was 18.36 (2.69). The amount of fluoride intake by food and drinking water in fluoridation area were significantly larger than that in non-fluoridation area but the statistical difference of fluoride intake by beverages between two areas was not observed. The GMs (GSDs) of daily fluoride excretion by urine of children in non-fluoridation area and in fluoridation area were 8.39 (1.73) and 18.62 (1.77) $\mu$g/kg/day, respectively. The correlation between fluoride intake from diet excluding beverage and urinary excretion was statistically significant. It is concluded that the amount of fluoride intake of children living in fluoridation area did not exceed the upper intake level to avoid the risk of dental fluorosis (2.2 mg/day in 4- to 8-year-olds) and urinary excretion of fluoride was good indicator of fluoride intake from diets.

• Journal of Korean society of Dental Hygiene
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• v.11 no.6
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• pp.1027-1038
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• 2011

Objectives : This study carried out the agreement of old people who visited senior citizens' centers in section area from January 5to 15, 2010. This study aimed to arrange basic data for the development in oral health and for the elderly oral health program, by surveying on regular level and food habit in the eating habits of the elderly. Methods : The regular level of dietary life, meal volume, meal time, kinds of meal preference, the appearance of snack intake, and kinds in snack preference were analyzed by using the statistical processing SPSS WIN 18 targeting totally 140 subjects, by preparing 1:1 questionnaire through direct interview. Results : The regular level of dietary life in the elderly was surveyed to be regular in 76.4% of the whole and to be irregular in 23.6%. As for the daily meal volume of the elderly, it was indicated to be 36.4% for 'eating proper volume' and to be 51.4% for 'eating a little.' As for the meal time of the elderly, it was indicated to be 52.1% for under 10 minutes and to be 25% for having a meal for 16~20 minutes. In the results of having surveyed on kinds of meal preference in the elderly, it was indicated to be 57.7% for having a meal 'centering on vegetables.' In the survey on snack intake of the elderly, it was indicated to be 62.1% for 'enjoying eating snack.' As for snack kinds of being preferred, 69.3% of the elderly were indicated to be the highest in 'fruits.' Conclusions : The elderly meals on a regular basis as needed by vegetarian diet, however showed thar eating a very short time. I consider it is necessary that study on connection between old people meal time, eating habits and oral physical condition.

• Asian Journal of Turfgrass Science
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• v.10 no.2
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• pp.105-115
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• 1996

To find out the mineral cycles of calcium, magnesium and sodium in dynamic grassland cosystems in a steady state condition, this investigation was conducted along the northwest side on Mt. Kwanak. The experimental results may he suromarized on the communities of a Zoysia japonica and a Miscanthus sinesis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, cal- cium (Ca) was greater quantity in a Zoysia japonica, whereas, in a Miscanthus sicensis, sodium (Na)and magnesium (Mg) were greater in Mt. Kwanak. For the case of steady production and release, the ratio of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants of Ca, Mg and Na of the litter were 0.42, 0.25 and 0.29 in the Zoysia japonica grassland, and were 0.41, 0.54 arid 0.62 in the Miscanthus sinensis grassland, respect- ively. The half times of Ca, Mg and Na required for the release or accumulation of the litter on the grassland were 1.65, 2.77 and 2.39 in the Zoysia japonica, and were 1.69, 1.28 and 1.12 in the Miscauthus sinensis, respectively. The increasing order of the turnover parameters of the elements was Ca, Na and Mg in the Zoysia japonica grassland, and was Na, Mg and Ca in the Miscanthus Si nens is grassland. The amounts of annual cycles for Ca, Mg, Na in the grassland ecosystem under the steady-state conditions were 1.29, 0.20 and 0.12 g /m$^2$ in the Zoysia japonica grassland and 3.91, 1.04 and 0.61 g /m$^2$ in the Miscanthus sinensis grassland.

• Korean Journal of Community Nutrition
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• v.18 no.6
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• pp.611-625
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• 2013

The purpose of this study was to investigate dietary behaviors and health-related lifestyles of adult visitors at a public health center in Gyeonggi urban area. A survey using questionnaire was conducted with 949 visitors at Seongnam public health centers from June to August, 2012. The data from 905 respondents were analyzed by gender, consisting of 322 males and 583 females, and age group, consisting of 243 low-age group (LA), 312 middle-age group (MA), 350 high-age group (HA), aged 20 to 30 years, 31 to 50 years, and 51 to 69 years, respectively. Average Body Mass Index was 23.0, which increased with age, and education level was high in LA. 59.0 percent of the subjects had various diseases, and the incidence of hypertension was the highest, followed by allergy, hyperlipidemia, diabetes mellitus, joint rheumatism. Incidence rates of chronic disease increased with age, which were lower than those from 2011 Korea National Health and Nutrition Examination Survey (KNHANES). Weekly drinking frequency rate and smoking rate decreased with age, and exercise performing rate was high at male and HA, which showed the same tendency as KNHANES. Female and HA showed more healthy dietary behaviors such as restricting salt, sugar, oily foods, foods containing food additives, calorie, caring for balanced diet, and referring to nutrition label. Subjects chose stress as the first factor, followed by diet, exercise, etc., among 13 suggested factors which strongly influence on human's life-span. In general, public health center visitors, especially female and HA, showed better dietary behaviors and health-related lifestyles compared with KNHANES.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.37 no.1
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• pp.69-85
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• 2024

Objectives : By analyzing articles on xerostomia and burning mouth syndrome, two representative diseases that cause various symptoms in oral cavity. Methods : We analyzed articles by dividing them into review articles, original articles, case reports. The subjects were 11 articles on xerostomia and 13 articles on burning mouth syndrome published in Korean medical journals. Results : 1. The subjects were 11 articles on xerostomia and 13 articles on burning mouth syndrome published in Korean medical journals. 2. The first article was published in 2007 and the most published articles were three each in 2013, 2018 and 2022. 3. Classification by type of article was as follows: 2 review articles(8.3%), 16 original articles(66.7%) and 6 case reports(25.0%). 4. The journal with the most published articles was journal of internal Korean medicine and the topics were xerostomia(72.7%), burning mouth syndrome(76.9%). 5. For both diseases, the number of female patients was higher than that of male patients. 6. The main symptom of xerostomia is dryness in the mouth and the main symptom of burning mouth syndrome is pain in the oral cavity. 7. Questionnaires, diagnosis based on dialectics and diagnostic devices were used to diagnose xerostomia and burning mouth syndrome. Conclusion : Diagnosis of xerostomia and burning mouth syndrome require overall consideration the entire hum an body along with the oral cavity. Since there are many different diagnostic methods, appropriate methods must be carefully selected and used.