• Asian Journal of Turfgrass Science
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• v.23 no.1
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• pp.133-142
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• 2009

This study was initiated to evaluate the K leaching potential in the green soils and K uptake by the turfgrass in the golf course using the K fertilizers. The turfgrass, Floradwarf bermudagrass(Cynodon dactylon L. $P_{ERS}$.) was planted and grown in the mixture of sand and peat moss in this lysimeter study. Eight representative K fertilizers, such as, monopotassium phosphate (MKP), KCL, $K_2SO_4$, $KNO_3$, CKCl, $CK_2SO_4$, $CKNO_3$, and 0-20-20(liquid) were used in this study. Based on the total K quantity of leachate collected during the whole 12 weeks, 0-20-20 is the K fertilizers the most contributing to the leaching of K, then MKP, the second, KCL, the third, and finally $KNO_3$ are K fertilizers contributing to the K leaching. However, most amount of K applied and collected in the lysimeter were leached during the first period of two and four weeks, compared to that of K leached during the second period of six, eight, ten, and twelve weeks. Application of CKCL and $CK_2SO_4$ producted the largest amount of total dry matter, then MKP and KCL, $KNO_3$ and $CKNO_3$, 0-20-20 in second group. However, except $K_2SO_4$, most K fertilizer sources such as MKP, KCL, $KNO_3$, CKCL, $CK_2SO_4$, $CKNO_3$, 0-20-20 showed the largest amount of K uptake, except $K_2SO_4$. Therefore, based on the K leaching, dry matter production, and plant K uptake, it appears that the coated fertilizers, CKCL, $CKNO_3$, and $CK_2SO_4$ are the environmentally sound fertilizers recommended in the turfgrass green soil of golf course.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.453-467
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• 2016

Overall risks that can occur in a shield TBM tunnelling are studied in this paper. Both the potential risk events that may occur during tunnel construction and their causes are identified, and the causal relationship between causes and events is obtained in a systematic way. Risk impact analysis is performed for the potential risk events and ways to mitigate the risks are summarized. Literature surveys as well as interviews with experts were made for this purpose. The potential risk events are classified into eight categories: cuttability reduction, collapse of a tunnel face, ground surface settlement and upheaval, spurts of slurry on the ground, incapability of mucking and excavation, and water leakage. The causes of these risks are categorized into three areas: geological, design and construction management factors. Bayesian Networks (BN) were established to systematically assess a causal relationship between causes and events. The risk impact analysis was performed to evaluate a risk response level by adopting an Analytic Hierarchy Process (AHP) with the consideration of the downtime and cost of measures. Based on the result of the risk impact analysis, the risk events are divided into four risk response levels and these levels are verified by comparing with the actual occurrences of risk events. Measures to mitigate the potential risk events during the design and/or construction stages are also proposed. Result of this research will be of the help to the designers and contractors of TBM tunnelling projects in identifying the potential risks and for preparing a systematic risk management through the evaluation of the risk response level and the migration methods in the design and construction stage.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.3
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• pp.13-19
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• 2018

The soldering property of Pb-containing solder(Sn-Pb) and Pb-free solders(Sn-3.0Ag-0.5Cu and Sn-1.0Ag-0.7Cu-1.6Bi-0.2In) for solar combiner box module was compared. The solar combiner box module was composed of voltage and current detecting modules, diode modules, and other modules. In this study, solder paste printability, printing shape inspection, solder joint property, X-ray inspection, and shear force measurements were conducted. For optimization of Pb-free soldering process, step 1 and 2 were divided. In the step 1 process, the printability of Pb-containing and Pb-free solder alloys were estimated by using printing inspector. Then, the relationship between void percentages and shear force has been estimated. Overall, the property of Pb-containing solder was better than two Pb-free solders. In the step 2 process, the property of reflow soldering for the Pb-free solders was evaluated with different reflow peak temperatures. As the peak temperature of the reflow process gradually increased, the void percentage decreased by 2 to 4%, but the shear force did not significantly depend on the reflow peak temperature by a deviation of about 0.5 kgf. Among different surface finishes on PCB, ENIG surface finish was better than OSP and Pb-free solder surface finishes in terms of shear force. In the thermal shock reliability test of the solar combiner box module with a Pb-free solder and OSP surface finish, the change rate of electrical property of the module was almost unchanged within a 0.3% range and the module had a relatively good electrical property after 500 thermal shock cycles.

• Journal of agricultural medicine and community health
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• v.27 no.1
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• pp.165-181
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• 2002

The purpose of this survey was to assess the nutritional status of preschool children a county of Jeju Island. This study used health examinations results for preschool aged children, performed by the public health center of Pukjeju-gun in Jeju-do for over three years from 1999 to 2001, of children in kindergartens and children homes. The target children totaled 5,990 from the ages three to six. For a control group, 316 children from the nearby Jeju-city areas were included as well. The items of this research included height, weight, and hemoglobin values. 1. The average height of boys from ages three to six were 96.35cm, 102.14cm, 109.94cm, 111.00cm respectively, and girls were 94.96cm, 100.93cm, 108.33cm, 110.54cm respectively. The average weights of boys from ages three to six were 15.42kg, 16.93kg, 19.65kg, 19.67kg respectively, and the weight of girls were 14.90kg, 16.45kg, 18.88kg, 19.50kg respectively. 2. The percentages of children who did not reach 90% of the Korean standard height were 4.3% in boys 4.1% in girls. The percentages of children with less than 80% of the Korean standard weight were 7.6% in boys and 6.8% girls. The percentages of children over 120% of Korean standard weight were 10.4% in boys and 11.4% in girls. 3. As for the obesity level, the percentage of boys under-weighed(under 10% for standard weight for height) were 11.6% and girls, 9.5%, and the percentages of boys and girls with obesity($\geq$20%) were 3.6% and 4.4% respectively. 4. The mean hemoglobin value of boys were 11.83g/$d\ell$ and girls, 11.83g/$d\ell$. These were lower than the value of average normal Korean children (12.5g/$d\ell$). The mena hemoglobin values of the children in Pukjeju-gun were considerably lower than that of the children living in Jeju-city(12.3g/$d\ell$) as well. Anemia of Children of Pukjeju-gun were estimated at 38.1%(male) and 37.2%(female), by using Hemoglobin level(<11.5g/$d\ell$ 5. The rates of children included within the normal range of obesity level in Jeju-city and Pukjeju- gun were boys 80.2%, 71.6% in boys, and 77.4%, 72.4% in girls. The percentage of children living in PukJeju-gun included within the normal range were considerably low. 6. There were no changes in the Body Mass Index (BMI) during the three years from 1999 to 2001, but the percentage of children with anemia significantly increased. Health care for preschool aged children, especially in the rural areas, is very important. Centering on public health centers, it is necessary to systematically promote health care in the rural areas.

• Journal of agricultural medicine and community health
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• v.25 no.2
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• pp.275-292
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• 2000

The purpose of this study was to analyze the relationship between knowledge, self-efficacy and quality of life of patients suffering from rheumatic arthritis. The data were collected from 100 rheumatic arthritis patients 1 university hospital, K rheumatic clinic in kwang-ju city for 20 days from March 2 to March 22, 1999, by means of questionnaires. The instruments used in this study were the knowledge scale developed by Kim, the self-efficacy scale developed by Long et al and the quality of life scale developed by Rho. The data were analyzed by t-test, ANOVA, Pearson's Correlation Coefficient, and Stepwise Multiple Regression by using the SAS program. The results of this study were summarized as follows : 1. The total mean score of knowledge was 15.01(SD${\pm}$3.08), In self-efficacy, the total mean score was 1030.40(SD${\pm}$233.42), In quality of life, the total mean score was 135.19(SD${\pm}$11.07). 2. The relationship between general characteristics and knowledge were significant difference in sex(t=19.03, p=.00), occupation(F=2.34, p=.03), types of exercise (F=2.95, p=.0.3), and time of exercise(F=3.20, p.=02). 3. The relationship between general characteristics and self-efficacy were significant difference in religion(F=2.75, p=.04), in monthly salary(F=3.64, p=.01), in occupation(F=2.30, p=.03), in period of rheumatic arthritis(F=2.70, F=.03), in time of exercise(F=3.77, P=.01), and in effectiveness of exercise (F=4.56, p= .02). 4. The relationship between general characteristics and quality of life were significant difference in age(F=3.36, p=.01), monthly income(F=3.11, p=.02), types of housing(t=4.93, p=.02), arid time of exercise(F=3.03, p=.03). 5. There was not significant correlation between the subjects knowledge and quality of life. 6. There was significant correlation between the self-efficacy and quality of life(r=462, p<.011). 7. The main factor influencing on quality of life was self-efficacy(21.4%).

• Journal of agricultural medicine and community health
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• v.25 no.2
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• pp.265-273
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• 2000

Benign prostatic hyperplasia (BPH) is a highly prevalent, age-related disorder in men which place a considerable burden on health care resources worldwide. While BPH and hypertension are apparently diverse disease processes, they have some features in common(e.g. underlying etiology of the sympathetic nervous system). The purpose of this study is to estimate the prevalence of lower urinary tract symptoms using I-PSS(international prostate symptom score) and to investigate the association of hypertension with I-PSS. This study was carried out to 390 men(40~86 year old) at 3 Myun in Chungju City from July to August, 1997. Subjects answered on questionnaire for I-PSS and were checked age, education, marital status, annual income, blood pressure. The mean age of subjects was 59.8 year old. The mean of I-PSS were increased by age decades(40~49, 50~59, 60~69, 70~86) and it's scores were 4.4, 7.0, 8.2, 12.3 respectively. Strong correlations were observed between the I-PSS and the QUL(quality of life)(P=0.0001). I-PSS(mean-value) were 7.85 in hypertensive group and 8.39 in normotensive group but there was no statistically significance between the two groups(P>0.05). The proportion of mean scoring greater than 8 was 42.5%. There have been reports of association between lower urinary tract symptoms and hypertension, but there was no consistent suggestion that such an association could be casual. The need for high-quality epidemiological information and consequent increased prospects for prevention is obvious.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.14 no.2
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• pp.197-208
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• 2003

Objective：In this study, we hypothesized that deficit in processing rapid linguistic stimuli is at the heart of Reading Disability(RD) and deficit in response inhibition is at the heart of Attention Deficit/Hyperactivity(ADHD). We conducted experiments to identify the core cognitive characteristics of children either with RD or with ADHD or with both, using attentional tasks and phoneme differential tests. Method：In the study 1, 28 children with ADHD, 16 children with RD+ADHD were individually administered visual/auditory performance tests. Then, the differences of performance on attentional tasks between two groups were compared while IQs of two groups were controlled. In the study 2, 13 children with RD+ADHD/RD, 13 children with ADHD, and 13 normal children were administered computerized phoneme differential tests. Result：Visual attentional tasks did not distinguish an ADHD group from a RD+ADHD group. With auditory attentional tasks, however, the comorbid group showed significantly more difficulties, causing a large variance in reaction time. RD, RD+ADHD, and ADHD groups showed more errors in phoneme differential tests than a normal control group, and each group showed distinctive performance patterns. Discussion：An ADHD group had difficulty in response inhibition and sustained attention, and children who also had RD along with ADHD magnified the auditory attentional difficulties. Even though children with RD had more trouble with responding correctly to target stimuli, their responses were not significantly different from those of children with ADHD.

• Spatial Information Research
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• v.22 no.1
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• pp.55-63
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• 2014

Near surface air temperature data which are one of the essential factors in hydrology, meteorology and climatology, have drawn a substantial amount of attention from various academic domains and societies. Meteorological observations, however, have high spatio-temporal constraints with the limits in the number and distribution over the earth surface. To overcome such limits, many studies have sought to estimate the near surface air temperature from satellite image data at a regional or continental scale with simple regression methods. Alternatively, we applied various Kriging methods such as ordinary Kriging, universal Kriging, Cokriging, Regression Kriging in search of an optimal estimation method based on near surface air temperature data observed from automatic weather stations (AWS) in South Korea throughout 2010 (365 days) and MODIS land surface temperature (LST) data (MOD11A1, 365 images). Due to high spatial heterogeneity, auxiliary data have been also analyzed such as land cover, DEM (digital elevation model) to consider factors that can affect near surface air temperature. Prior to the main estimation, we calculated root mean square error (RMSE) of temperature differences from the 365-days LST and AWS data by season and landcover. The results show that the coefficient of variation (CV) of RMSE by season is 0.86, but the equivalent value of CV by landcover is 0.00746. Seasonal differences between LST and AWS data were greater than that those by landcover. Seasonal RMSE was the lowest in winter (3.72). The results from a linear regression analysis for examining the relationship among AWS, LST, and auxiliary data show that the coefficient of determination was the highest in winter (0.818) but the lowest in summer (0.078), thereby indicating a significant level of seasonal variation. Based on these results, we utilized a variety of Kriging techniques to estimate the surface temperature. The results of cross-validation in each Kriging model show that the measure of model accuracy was 1.71, 1.71, 1.848, and 1.630 for universal Kriging, ordinary Kriging, cokriging, and regression Kriging, respectively. The estimates from regression Kriging thus proved to be the most accurate among the Kriging methods compared.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.4
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• pp.41-54
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• 2002

In this study, we have analyzed the effects of the membrane layer and the bragg reflector layers on the resonance characteristics through comparing the characteristics of the membrane type FBAR (Film Bulk Acoustic Wave Resonator) and the one type bragg reflector layers with those of the ideal FBAR with top and bottom electrode contacting air by using equivalent circuit technique. It is assumed that ZnO is used for piezoelectric film, $SiO_2$ are used for membrane layer and low acoustic impedance layer, W are used for the high acoustic reflector layer and Al is used for the electrode. Each layer is considered to have a acoustic propagation loss. ABCD parameters are picked out and input impedance is calculated by converting 1-port equivalent circuit to simplified equivalent circuit that ABCD parameters are picked out possible. From the variation of resonance frequency due to the change of thickness of electrode layers, reflector layers and membrane layer it is confirmed that membrane layer and the reflector layer just under the electrode have the greatest effect on the variation of resonance frequency. From the variation of resonance properties, K and electrical Q with the number of layers, K is not much affected by the number of layers but electrical Q increases with the number of layers when the number of layers is less than seven. The electrical Q is saturated when the number of layers is large than six. The electrical Q is dependent of mechanical Q of reflector layers and membrane layer. Both ladder filter and SCF (Stacked Crystal Filters) show higher insertion loss and out-of-band rejection with the increase of the number of resonators. The insertion loss decreases with the increase of the number of reflector layers but the bandwidth is not much affected by the number of reflector layers. Ladder Filter and SCF with membrane layer show the spurious response due to spurious resonance properties. Ladder filter shows better skirt-selectivity characteristics in bandwidth but SCF shows better characteristics in insertion loss.

• Clean Technology
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• v.22 no.1
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• pp.16-28
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• 2016

Textile industry is considered as one of the most polluting sectors in terms of effluent composition and volume of discharge. It is well known that the effluents from textile dying industry contain not only chromatic substances but also large amounts of organic compounds and insolubles. The azo dyes generate huge amount of pollutions among many types of pigments. In general, the electrochemical treatments, separating colors and organic materials by oxidation and reduction on electrode surfaces, are regarded as simpler and faster processes for removal of pollutants compared to other wastewater treatments. In this paper the electrochemical degradation characteristics of dye wastewater containing CI Direct Blue 15 were analyzed. The experiments were performed with various anode materials, such as RuO₂/Ti, PtO₂/Ti, IrO₂/Ti and graphite, with stainless steel for cathode. The optimal anode material was located by changing operating conditions like electrolyte concentration, current density, reaction temperature and initial pH. The degradation efficiency of dye wastewater increased in proportion to the electrolyte concentration and the current density for all anode materials, while the temperature effect was dependent on the kind. The performance orders of anode materials were RuO₂/Ti > PtO₂/Ti > IrO₂/Ti > graphite in acid condition and RuO₂/Ti > IrO₂/Ti > PtO₂/Ti > graphite in neutral and basic conditions. As a result, RuO₂/Ti demonstrated the best performance as an anode material for the electrochemical treatment of dye wastewater.