• Korean Journal of Ecology and Environment
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• v.41 no.spc
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• pp.35-41
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• 2008

Nutrient Enrichment Bioassays (NEBs) were conducted in the laboratory during June $22{\sim}28$, 2006 in order to determine primary limiting factor on the phytoplankton growth. For the NEBs, the water was sampled using a 10L polyethylene-lined container and dispensed into 2.5L container in the laboratory. The algal growths response in the control (C) and three treatments of phosphorus (P), 2-fold phosphorus (2P), and nitrate nitrogen $(NO_3-N)$ were monitored during 7 days. In the cubitainers which were spiked as P (T1) and 2P (T2) Chl-${\alpha}$ concentrations were decreased during the test period and the final concentrations was low than initial values. However, Chl-${\alpha}$ in the cubitainers which were spiked as $NO_3$(T3) and $P+NO_3$(T4) showed significant increases compared to the initial values, indicating that in the short-term experiments, nitrogen seemed to be a primary limiting nutrient during the periods of NEBs experiment. Long-term ambient nutrient data of TP and TN, and TN:TP mass ratios, however, showed a potential phosphorus limitation on phytoplankton growth and previous other researchers showed a variations of limiting nutrients by nitrogen or phosphorus depending on the seasons sampled and locations. In this study nitrogen as primary limiting nutrient in the NEBs seem to be an seasonal effect rather than the consistent nitrogen limitation.

• Journal of Korean Home Economics Education Association
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• v.20 no.3
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• pp.145-161
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• 2008

The purpose of this paper is to find out the needs of housing contents in highschool Home Economics among students. The 105 housing contents and topics were chosen from the 3 textbooks and related references. The number of 516 questionnaire from 8 areas were used to analyze. Analyses indicated that respondents were more likely to favor Home Economics subject and one out of five wanted to select it. Average needs of the housing contents was above middle(3.4) and these was a little difference among 3 middle units in housing. The most needed unit was housing design. There was a more wide difference in 19 small units than in middle ones, ranged $3.00\sim3.91$. Individual contents showed the most variousness in needs from 2.89 to 4.30 in the middle unit of housing and environments, 3.00 to 4.01 in housing design, and 2.68 to 3.91 in housing management. The needs of additional contents were about the same as those textbook contents and it indicated that new textbook needs to adopt the newly demanded housing contents. Some of individual, family, and environmental characteristics were significantly related to the students needs. The higher positive attitude such as favor, interest, and selecting of the subject was related to the higher needs of housing contents. Residential areas and neighboring were also related to most of the needs of individual housing contents.

• Korean Journal of Remote Sensing
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• v.35 no.3
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• pp.457-470
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• 2019

Automatic Target Recognition (ATR) using Synthetic Aperture Radar (SAR) has been attracted attention in the fields of surveillance, reconnaissance, and national security due to its advantage of all-weather and day-and-night imaging capabilities. However, there have been some difficulties in automatically identifying targets in real situation due to various observational and environmental conditions. In this paper, ATR problems in Extended Operating Conditions (EOC) were investigated. In particular, we considered partial occlusions of the target (10% to 50%) and differences in the depression angle between training ($17^{\circ}$) and test data ($30^{\circ}$ and $45^{\circ}$). To simulate various occlusion conditions, SARBake algorithm was applied to Moving and Stationary Target Acquisition and Recognition (MSTAR) images. The ATR accuracies were evaluated by using the template matching and Adaboost algorithms. Experimental results on the depression angle showed that the target identification rate of the two algorithms decreased by more than 30% from the depression angle of $45^{\circ}$ to $30^{\circ}$. The accuracy of template matching was about 75.88% while Adaboost showed better results with an accuracy of about 86.80%. In the case of partial occlusion, the accuracy of template matching decreased significantly even in the slight occlusion (from 95.77% under no occlusion to 52.69% under 10% occlusion). The Adaboost algorithm showed better performance with an accuracy of 85.16% in no occlusion condition and 68.48% in 10% occlusion condition. Even in the 50% occlusion condition, the Adaboost provided an accuracy of 52.48%, which was much higher than the template matching (less than 30% under 50% occlusion).

• Journal of Nutrition and Health
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• v.57 no.1
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• pp.136-152
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• 2024

Purpose: A comprehensive evaluation item was developed to assess adolescent dietary habits and nutritional practices, considering food intake, eating behaviors, and food culture, such as social support and food environment. Methods: The 59 candidate items of the evaluation checklist were obtained based on the results of the eighth Korea National Health and Nutrition Examination Survey data, Korea Dietary Reference Intakes, dietary guidelines for adolescents, Youth Risk Behavior Survey data, national nutrition policies and dietary guidelines, and literature reviews. Four hundred and three middle and high school students residing in metropolitan areas participated in a survey using the 58-item checklist, which was selected through expert evaluation and content validity ratio analysis. The construct validity of the assessment tool for the quality of adolescent diets was assessed by exploratory factor analyses to determine if the checklist items were organized properly and whether the responses to each item were distributed adequately. Results: The Bartlett sphericity test was significant for each area (p <0.001), and the eigen values were greater than one. The Kaiser-Meyer-Olkin and cumulative proportions by areas were food intake (0.765 and 56.8%, respectively), eating behaviors (0.544 and 64.8%, respectively), and food environment (0.699 and 62.4%, respectively). Twenty-two checklists were determined for the final evaluation items for the adolescents' dietary habits and nutritional practices and were categorized into three distinct factors: food intake (10 items), eating behaviors (4 items), and food environment (8 items). Conclusion: The evaluation items for adolescent dietary habits and nutritional practices is a useful checklist for easily and quickly assessing the dietary qualities and reflecting Korean adolescents and their food environmental factors related to a sustainable diet.

• Environmental and Resource Economics Review
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• v.22 no.3
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• pp.521-545
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• 2013

This study applied choice experiment(CE) method(which is included in the stated preference method) to estimate values of some important attributes(i.e. type of estuary, water quality of river in estuary, water quality of sea in estuary, biodiversity level of estuary) of 4 major river(Hangang, Guemgang, Yeongsangang, Nakdonggang) estuaries in Korea. Although the multinomial logit model(MNL) is generally applied to analyse the CE data, testing for IIA assumption with the Hausman and McFadden test in MNL model shows that the IIA assumption in our data is rejected. Therefore, the heteroscedastic extreme value model(HEV) and the multinomial probit model(MNP) which are not based on the IIA assumption are used to analyse our CE data. As results, the coefficients and the elicited economic values of MNL model are seriously distorted if the IIA assumption is not satisfied in MNL model. The estimation results of MNP model show that the economic values are elicited as 352.3 billion won(95% C.I. 261.1 - 477.8 billion won) for natural estuary, 411.5 billion won(95% C.I. 338.5 - 525.5 billion won) for one grade improvement of river water quality in estuary, 358.9 billion won(95% C.I. 292.5 - 457.0 billion won) for one grade improvement of sea water quality in estuary, and 151.9 billion won(95% C.I. 99.0 - 218.6 billion won) for one grade improvement of biodiversity level of estuary. Therefore, the value of estuary is reached to 2,197.0 billion won(95% C.I. 1,721.0 - 2,879.9 billion won) if any natural estuary in 4 major rivers has good water quality of river in estuary(i.e. 2nd grade), good water quality of sea in estuary(i.e. 1st grade), and good biodiversity level of estuary.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.406-413
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• 2019

The purpose of this research was to analyze the effect of different sowing times on the flowering and maturing of major soybean cultivars by varying day length and temperature in the central plain region. The average of growth period and cumulative temperature in five test cultivars by sowing times were 121 days and 2,972℃ on June 1, respectively and gradually decreased to 85 days, 2,042℃, respectively on July 20. Analysis of the flowering response according to the sowing times showed that flowering was greatly influenced by the decrease of photoperiod until the sowing on July 10, and the minimum number of days for flowering were 27 days, 36 days, respectively in early and mid-rate maturing type in the central plain region. Daepung 2 is classified to the same ecotype with Daewonkong, the total number of growing days was not different between two cultivars, but ripening period (R2-R6) was longer by 5 days and yield was higher by 11% in Daepung 2. The maturity rate was also high and safe enough to maintain more than 90% through the entire sowing times. This ecological characteristic can be usefully applied as a section index for breeding environmental stress resistant and high yielding soybean varieties. The yield of 4 domestic cultivars (except TI196944) sowing on July 20 were 85~92% levels compared to sowing on June 20.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.2
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• pp.199-210
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• 2005

Objective : Attention deficit hyperactivity disorder(ADHD) affects $5-10\%$ of children in Korea, with more boys and girls being diagnosed. Despite seriousness of ADHD, little is known about its causes. From the current genetic epidemiologic studies, ADHD is known as a heritable disorder. Till now, however, there have been very few genetic studies about ADHD in Korea. The aim of the this study is to examine the association between dopamine transporter gone type 1 and ADHD using case-control design in Korean ADHD probands and normal controls. Materials and Method : Child Psychiatric Genetic research team in Seoul National University Hospital, Clinical Research Institute recruited the ADHD probands using clinical interview/observation, diverse rating scales, and neuropsychological tests. For eliminating phenocopy or ADHD, diagnosis of ADHD was based upon clinical data, psychometric data, and parent/teacher reports. Total 85 ADHD-probands were recruited as final study subjects and independent 100 normal adults participated in this study as control group. For all the ADHD probands, and controls, the 3'-UTR-VNTR polymorphism of DAT1 was analyzed. Based on the DAT1 allele and genotype informations, Chi-square test based on case-control design was performed. Results : As for genetic study, total of 85 probands and 100 controls were included for the genetic analysis. Four different alleles, 350bp (7repeat), 440bp (9repeat), 480bp (10repeat) and 520bp (11repeat) were found in DAT1 gene of study subjects. In case-control analysis, ADHD probands and parents have significantly more 9 repeat allele and 9/10 genotype. Also, The probands with 9repeat allele have more commission errors in ADS. Conclusion : The positive association between ADHD and DAT1 gene was replicated in this report like other previous results for caucasian children and Korean children with ADHD. There are ongoing studies on other candidate genes such as DRD4 and DRD5 and it would be required to explore the association of these candidate genes in Korean children with ADHD. These ongoing genetic research will contribute to the understanding of heterogenous genetic and environmental etiologies of ADHD phenotype, which will lead to the development of more comprehensive treatment and preventive interventions for ADHD.

• Journal of Preventive Medicine and Public Health
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• v.32 no.2
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• pp.177-182
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• 1999

Objectives: To reexamine the association between air pollution and daily mortality in Seoul, Korea using a method of meta-analysis with the data filed for 1991 through 1995. Methods: A separate Poisson regression analysis on each district within the metropolitan area of Seoul was conducted to regress daily death counts on levels of each ambient air pollutant, such as total suspended particulates (TSP), sulfur dioxide $(SO_2)$, and ozone $(O_3)$, controlling for variability in the weather condition. We calculated a weighted mean as a meta-analysis summary of the estimates and its standard error. Results: We found that the p value from each pollutant model to test the homogeneity assumption was small (p<0.01) because of the large disparity among district-specific estimates. Therefore, all results reported here were estimated from the random effect model. Using the weighted mean that we calculated, the mortality at a $100{\mu}g/m^3$ increment in a 3-day moving average of TSP levels was 1.034 (95% Cl 1.009-1.059). The mortality was estimated to increase 6% (95% Cl 3-10%) and 3% (95% Cl 0-6%) with each 50 ppb increase for 9-day moving average of SO2 and 1-hr maximum O3, respectively. Conclusions: Like most of air pollution epidemiologic studies, this meta-analysis cannot avoid fleeing from measurement misclassification since no personal measurement was taken. However, we can expect that a measurement bias be reduced in a district-specific estimate since a monitoring station is hefter representative cf air quality of the matched district. The similar results to those from the previous studios indicated existence of health effect of air pollution at current levels in many industrialized countries, including Korea.

• Journal of Appropriate Technology
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• v.7 no.2
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• pp.127-135
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• 2021

To respond to the threat of global warming, countries around the world are promoting the spread of renewable energy and reduction of carbon emissions. In accordance with the United Nation's Sustainable Development Goal to combat climate change and its impacts, global automakers are pushing for a full transition to electric vehicles within the next 10 years. Electric vehicles can be a useful means for reducing carbon emissions, but in order to reduce carbon generated in the stage of producing electricity for charging, a power generation system using eco-friendly renewable energy is required. In this study, we propose a smart electric mobility operating system integrated with off-grid solar power plants established in Tanzania, Africa. By applying smart monitoring and communication functions based on Arduino-based computing devices, information such as remaining battery capacity, battery status, location, speed, altitude, and road conditions of an electric vehicle or electric motorcycle is monitored. In addition, we present a scenario that communicates with the surrounding independent solar power plant infrastructure to predict the drivable distance and optimize the charging schedule and route to the destination. The feasibility of the proposed system was verified through test runs of electric motorcycles. In considering local environmental characteristics in Tanzania for the operation of the electric mobility system, factors such as eco-friendliness, economic feasibility, ease of operation, and compatibility should be weighed. The smart electric mobility operating system proposed in this study can be an important basis for implementing the SDGs' climate change response.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.87-95
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• 2002

The slow degradation rate of sludge in anaerobic digestion is due to rate-limiting step of sludge hydrolysis. To upgrading of sludge hydrolysis and biodegradabiliry, the pre-treatment had been carried out using acidlc (pH 1.5, 3, 4, 5) and alkaline (pH 9, 10, 13), thermal (50, 100, 150, $200^{\circ}C$), and ultrasonic treatment (400W, 20kHz, 15, 20, 25, 30, 40, 50, 60, 90min). In the best conditions of each treatment, the Soluble SCOD Ratio(%)of treated/untreated sample were increased 102% in acid (pH5), 986% in alkali (pH 13), 595% in thermal ($200^{\circ}C$) and 1123% in ultrasonic (35min) treatment. As the result, the ultrasonic treatment was most effective, followed by alkali, thermal, acid treatment. In the effects of total gas productivity in vial test, the thermal ($200^{\circ}C$) pre-treatment was the highest, followed by thermal ($150^{\circ}C$), ultrasonic (90min), alkaline (pH 9), and ultrasonic (50min). We compared untreated samples and the most efficient pre-treatment samples(at $200^{\circ}C$, for 30min) on gas productivity with changes of HRT in continuous experiments IN thermal treated samples were 2.5 times in SCOD, 2 times in soluble protein and 3.3 times high in soluble carbohydrate than untreated ones. In gas productivity, the thermal treated samples were average 2 times high than untreated ones. And HRT 7 days was most effective. followed by HRT 10, HRT 15 days. But The gas productiviry of HRT 2.5 days was less than untreated, the reason of low gas productivity was come from high organic acids accumulation within reactor.