• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.134-145
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• 2023

Currently, the floodplains of major rivers are transforming into various types of waterfront spaces according to the increase in leisure activities and improved accessibility. In general, waterfront activities in river channels tend to be concentrated in summer, and the waterfront activities during this period directly affect water quality. Accordingly, it is necessary to accurately compare and evaluate the characteristics and water quality of waterfront activities during the period when waterfront activities are concentrated. In this study, the following research was conducted to compare and analyze the current status of waterfront activities of users of waterfront areas and the water quality of waterfront areas. First, three waterfront areas were selected for investigation using the information from the Ministry of Environment's water quality measurement network. Second, a survey was conducted on the satisfaction and types of waterfront activities targeting users of waterfront areas. Third, water quality grades were calculated based on monthly water quality measurement factors and compared. Fourth, statistical analysis (one-way analysis of variance) was conducted to see if there was a significant difference in water quality characteristics between periods of high waterfront activity and periods of low waterfront activity using water quality measurement data for the last 5 years. As a result of this analysis, the following conclusions were drawn in this study. First, the use of waterfront activities was investigated in the order of camping, water skiing, fishing, swimming, and rafting. Second, satisfaction factors for waterfront activities were investigated in the order of activity convenience, water quality, waterlandscape, transportation access convenience, and temperature. Third, it was found that satisfaction with water quality in waterfront areas was generally unsatisfactory regardless of the water quality grade presented by the competent authority. Fourth, as a result of comparing the water quality measurement network data of the Ministry of Environment by water quality grade, generally good grades were found, and in particular, there was a difference in grade frequency by season in the BOD category. Fifth, as a result of statistical analysis (one-way ANOVA) of water quality monitoring network data by season, there were statistically significant differences in COD, BOD, TP, and TOC except for DO. Considering the results of these studies, it is judged that it is necessary to prepare a comprehensive management system for water quality improvement in the waterfront zone and to improve water quality during periods of high waterfront activity, and to prepare a water quality forecasting system for waterfront areas in the future.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1690-1696
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• 2006

The purpose of this study is to provide the basic data useful in designing apparel patterns for aged abdominal obese women. The body measurements of 318 women were taken at random, whose ages were over 60 and fields of action were colleges, sports centers, or business sites in Seoul and the neighboring districts. A total of 33 features in the upper body and lower body were used fer the anthropometric measurement and analysis using anthropometry. The collected measurement data were processed statistically using the SPSS 12.0 program for technical statistical analysis, t-test, frequency analysis, correlation analysis. The results of the study are as follows. 1. Subjects were classified into two groups as a result of analysis for measurement data. It was revealed that 251(about 79 percent) women of total subjects(n=318) have a characteristic of abdominal obese body type and elderly women of these group usually had big abdomen rather than hip. The criteria of abdominal obesity based on waist-hip ratio, WHR(=0.85). 2. Aged abdominal obese women have shown much larger size in most body measurements except items of some vertical length, such as bust ponit-bust point, font interscye, back interscye with circumference and depth of armscye, bust, waist, abdomen and hip while showing no difference in height, biacrominal breadth, hip width, neck shoulder point to breast point, crotch length. 3. Vervaeck index(=100.1) and Rohrer index(=1.7) indicated that the abdominal obese women were fat in overall body. And aspect ratio of waist(=0.86), abdomen(=0.92) and hip(=0.75) also appeared high that the shape of cross sections in those regions was similar to a figure of circle 4. In view of the correlation coefficient between hip circumference and the rest measurement items, and between hip circumference inclusively of the abdomen protrusion and the rest measurement items, there were found some differences for each group. In case of Group (abdominal obese group), the former is smaller than the other. 5. In case of Abdominal obese women, hip circumference inclusively of the abdomen protrusion is more mutually related to the rest items related to make apparel pattern as waist circumference, depth of armscye and so on than what hip circumference is. This result indicated which must be considered hip circumference inclusively of the abdomen protrusion to make apparel patterns for abdominal obese women unlike women of common body types.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.123-158
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• 2009

An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.818-831
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• 2008

The purpose of this study was to investigate the dietary behavior, health-related lifestyles and nutrient intake status of college students according to physical activity levels. The physical activity levels were measured using the Korean version of the International Physical Activity Questionnaire (IPAQ) short form. The subjects of this study were 438 college students (243 males and 195 females) in Incheon area and were divided by gender and by physical activity levels, which included low, moderate and high physical activity groups. The average age of male and female students were 23.7 and 21.0 years old, respectively. The prevalence of the low physical activity group was 11.5% for males and 30.8% for females and that of the high physical activity group was 38.7% for males and 22.6% for females. According to the criteria for obesity in Asia-Pacific region, 39.1% of the males and 64.1% of the female students investigated were in the normal range of BMI and 30.9% of the males and 4.6% of the female students were in the obesity category. However, percent of body fat in the female students was significantly higher than that of the male students. The soft lean mass of the high physical activity group was higher compared to the other groups. In the low physical activity group, frequency of “eating out” was lower compared to the other groups. The average consumption of energy was 74.4% for males and 80.1% for females of the estimated energy requirement (EER). The mean intakes of vitamin C, vitamin B2, folic acid and Ca were 67.3%, 84%, 52.7% and 36.7% for males and 64.8%, 99.9%, 51.1% and 40.1% for females of recommended intake (RI), respectively. Therefore, it was necessary for obesity prevention as well as health promotion to increase physical activity and to eat an adequate, balanced diet in female college students.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.450-459
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• 2009

The aim of this study was to measure the initial dynamic modulus changes of light cured composites using a custom made rheometer. The custom made rheometer consisted of 3 parts: (1) a measurement unit of parallel plates made of glass rods, (2) an oscillating shear strain generator with a DC motor and a crank mechanism, (3) a stress measurement device using an electromagnetic torque sensor. This instrument could measure a maximum torque of 2Ncm, and the switch of the light-curing unit was synchronized with the rheometer. Six commercial composite resins [Z-100 (Z1), Z-250 (Z2), Z-350 (Z3), DenFil (DF), Tetric Ceram (TC), and Clearfil AP-X (CF)] were investigated. A dynamic oscillating shear test was undertaken with the rheometer. A certain volume ($14.2\;mm^3$) of composite was loaded between the parallel plates, which were made of glass rods (3 mm in diameter). An oscillating shear strain with a frequency of 6 Hz and amplitude of 0.00579 rad was applied to the specimen and the resultant stress was measured. Data acquisition started simultaneously with light curing, and the changes in visco-elasticity of composites were recorded for 10 seconds. The measurements were repeated 5 times for each composite at $25{\pm}0.5^{\circ}C$. Complex shear modulus G*, storage shear modulus G', loss shear modulus G" were calculated from the measured strain-stress curves. Time to reach the complex modulus G* of 10 MPa was determined. The G* and time to reach the G* of 10 MPa of composites were analyzed with One-way ANOVA and Tukey's test ($\alpha$ = 0.05). The results were as follows. 1. The custom made rheometer in this study reliably measured the initial visco-elastic modulus changes of composites during 10 seconds of light curing. 2. In all composites, the development of complex shear modulus G* had a latent period for $1{\sim}2$ seconds immediately after the start of light curing, and then increased rapidly during 10 seconds. 3. In all composites, the storage shear modulus G" increased steeper than the loss shear modulus G" during 10 seconds of light curing. 4. The complex shear modulus of Z1 was the highest, followed by CF, Z2, Z3, TC and DF the lowest. 5. Z1 was the fastest and DF was the slowest in the time to reach the complex shear modulus of 10 MPa.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.862-877
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• 2008

In this paper, two types of wideband 3-dB ring hybrids are compared and discussed to show the ring hybrid with a set of coupled-line sections better. However, the better one still has a realization problem that perfect matching can be achieved only with -3 dB coupling power. To solve the problem, a set of coupled-line sections with two shorts is synthesized using one- and two-port equivalent circuits and design equations are derived to have perfect matching, regardless of the coupling power. Based on the design equations, a modified ${\Pi}-type$ of transmission-line equivalent circuit is newly suggested. It consists of coupled-line sections with two shorts and two open stubs and can be used to reduce a transmission-line section, especially when its electrical length is greater than ${\pi}$. Therefore, the $3\;{\lambda}/4$ transmission-line section of a conventional ring hybrid can be reduced to less than ${\pi}/2$. To verify the modified ${\Pi}-type$ of transmission- line equivalent circuit, two kinds of simulations are carried out; one is fixing the electrical length of the coupled-line sections and the other fixing its coupling coefficient. The simulation results show that the bandwidths of resulting small transmission lines are strongly dependent on the coupling power. Using modified and conventional ${\Pi}-types$ of transmission-line equivalent circuits, a small ring hybrid is built and named a compact wideband coupled-line ring hybrid, due to the fact that a set of coupled-line sections is included. One of compact ring hybrids is compared with a conventional ring hybrid and the compared results demonstrate that the bandwidth of a proposed compact ring hybrid is much wider, in spite of being more than three times smaller in size. To test the compact ring hybrids, a microstrip compact ring hybrid, whose total transmission-line length is $220^{\circ}$, is fabricated and measured. The measured power divisions($S_{21}$, $S_{41}$, $S_{23}$ and $S_{43}$) are -2.78 dB, -3.34 dB, -2.8 dB and -3.2 dB, respectively at a design center frequency of 2 GHz, matching and isolation less than -20 dB in more than 20 % fractional bandwidth.

• The Journal of Korean Medicine
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• v.28 no.2 s.70
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• pp.66-79
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• 2007

Objectives : To explore the type and frequency of short term reactions, de Qi associated with acupuncture treatment and to determine the incidence of adverse events following acupuncture in Korea. Subjects and methods : This study is a retrospective and cross-sectional survey of patient reports. 1095 subjects, 585 of out-patients of the Oriental Medicine of Stroke & Neurological Disorders Center, East-West NEO Medical Center of Kyunghee University and 510 of out-patients of the Department of Cardiovascular & Neurologic Diseases (Stoke Center), Hospital of Oriental Medicine, Kyunghee Medical Center, from June through November of 2006, who had acupuncture, gave informed consent and completed one survey form. On this form, patients were asked to report short term acupuncture reactions, de Qi, patient satisfaction measurement (using VAS), and adverse events relating to acupuncture treatment. The acupuncturists of this study are Korean Medicine Doctors (KMD) who had worked as practitioners for 3-30 years or more. Results : The average age of the 1095 subjects was 58 years old. Positive short term acupuncture reactions after treatment were reported by 878 (80.2%), negative short term acupuncture reactions by 75 (6.8%) and no reactions were reported by 142 (13.0%). The most common positive short term acupuncture reactions were feeling 'relaxed', 472 (43.1%), followed by feeling 'less pain' 90 (8.2%), 'energized' 16 ( 1.5%), 'tingling' 16 (1.5%), 'heat feeling or Cold feeling' 10 (0.9%), and others 274 (25.0%), respectively. Negative short term acupuncture reactions were feeling 'pain' 37 (3.4%), tiredness 24 (2.2%), dizziness 9 (0.8%), and others 5 (0.2%), respectively. Traditionally described needling sensations of de Qi refer to a patient's response to distention, pulling, soreness, heaviness, numbness. 39.7% of subjects reported de Qi during needling, experiencing 'distention' 333 (30.4%), 'soreness' 52 (4.7%), 'pulling' 22 (2.0%), 'heaviness' 18 (1.6%), and 'numbness' 10 (0.9%) respectively. Positive short term acupuncture reactions and de Qi rate were the highest in the less than 40 years group (83/96 86.5%, 50/96 52.1%). No acupuncture reactions were highly seen in the over 70 years old group (31/187, 16.6%). Patient satisfaction level using VAS was a comparatively high $72.9{\pm}19.9$. Adverse events were only bleeding in 92 (8.4%) of the total subjects. High sensitive acupoints were 95 points as GV26 (54 times), LI4 (54 times), ST36 (53 times), GB20 (37 times), HT8(34 times), LV3 (29 times), SI3 (29 times), and LI11 (27 times) in order. Main impressions were stroke patients 430 (16.9%), headache 185 (16.9%), hypertension 97 (8.9%), and dizziness 85 (7.8%). Conclusions : Although 8 different Korean Medicine Doctors participated in this research, we obtained similar results from each. There were no significantly different results between the two hospitals. Short term acupuncture reactions and de Qi were most related to age. Except for bleeding there were no adverse events relating to acupuncture treatment in this study. We consider acupuncture treatment as very safe depending on practitioners. Positive short term acupuncture reactions after treatment were 12 times higher than negative short term acupuncture reactions. Subjects were comparatively satisfied with acupuncture treatment.

• Journal of Korean Home Economics Education Association
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• v.31 no.3
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• pp.179-192
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• 2019

This study was performed to analyze the contents of food intake in middle school Home Economics textbook and the trends of food intake of middle school students in Korea to figure out the education direction of food intake. The contents of food intake were analyzed in major three kinds of middle school Home Economics textbook according to 2015 curriculum and the trends of food and nutrient intake were analyzed in 2,543 subjects aged 13 to 15 years using 2007~2015 Korea National Health and Nutrition Examination survey by logistic regression analysis or Pearson correlation coefficient. As a result, contents of food intake of textbook included food source of nutrient, food group name, necessity of eating diverse foods, recommended daily eating frequency of food group and menu planning according to meal composition guideline, however food intake trends were not included. Consumption of grains and grain products was increased until 2007 to 2010 year and was decreased after 2011 year(p=0.0012). Sugars and sweets, beverages and alcohols, and fish and shellfish consumption were increased during 2007~2015 year(p<0.0001). Carbohydrate, fat, vitamin A, thiamin and iron intakes were increased(p=0.0052), and energy ratio by carbohydrate was decreased(p=0.0009) and energy ratio by fat was increased(p<0.0001) during 2007~2015 year. Mean ratios of nutrient intake compared to the dietary reference intakes for Koreans were very low in dietary fiber(19-27%) and calcium(46-56%), but was higher in sodium(221-289%)(p<0.0001) regardless of year. There was a significant positive correlation between most food group intakes except sugars and sweets, bean and bean products, nuts and seeds, seaweeds, and beverages and alcohols and energy, protein, dietary fiber, vitamin A, riboflavin, calcium and iron intakes(p=0.0375). In the above, during the period from 2007 to 2015 year, intakes of sugars and sweets, beverages and alcohols, and fish and shellfish were increased, and intakes of dietary fiber and calcium were low and energy ratio by fat was increased, thus these trends are concerned to threaten nutritional balance and health of subjects. Therefore, Home Economics textbook of middle school needs to include food intake trends of adolescents with basic concepts to help them maintain balanced diet in the rapid change of food intake patterns for maintaining optimal nutrition and health.

• Progress in Medical Physics
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• v.23 no.3
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• pp.154-161
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• 2012

Digital Radiography (DR) has rapidly developed in megavoltage X-ray imaging (MVI). Thus, a very simple and general quality assurance (QA) method is required. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS) and the detective quantum efficiency (DQE) for MVI using general QA method and computed radiography (CR) device. We used tungsten edge block with $19{\times}10{\times}1cm^3$ thickness and 6MV energy. For detector, CR-IP (image plate), CR-IP-lead, the CR-IP-back (lanex TM fast back screen), CR-IP-front (lanex TM fast front screen) were used and pre-sampling MTF was calculated. The MTF of CR-IP-front showed the highest value with 1.10 lp/mm although the CR-IP showed the only 0.70 lp/mm. The best NPS was observed in CR-IP front screen. According to the increase in spatial frequency, our results showed that DQE was approximately 1.0 cycles/mm. The present study demonstrates that the QA method with our home-made edge block can be used to evaluate MTF, NPS and DQE for MVI.

• Investigative Magnetic Resonance Imaging
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• v.10 no.2
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• pp.98-107
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• 2006

Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.