• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.183-183
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• 2017

Pan evaporation (Epan) is an important indicator of water and energy balance. Despite global warming, decreasing annual Epan has been reported across different continents over last decades, which is claimed as pan evaporation paradox. However, such trend is not necessarily found in seasonal data because the level of contributions on Epan vary among meteorological components. This study investigates long-term trend in seasonal pan evaporation from 1908 to 2016 across South Korea. Meteorological variables including air temperature (Tair), wind speed (U), vapor pressure deficit (VPD), and solar radiation (Rs) are selected to quantify the effects of individual contributing factor to Epan. We found overall decreasing trend in Epan, which agrees with earlier studies. However, mixed tendencies between seasons due to variation of dominant factor contributing Epan were found. We also evaluated the reference evapotranspiration based on Penman-Monteith method and compared this with Epan to better understand the physics behind the evaporation paradox.

• International Journal of Contents
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• 제17권1호
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• pp.18-26
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• 2021

The obesity leads to be the result of the weakening of anatomical structure as well as the gravity effect. And, the obesity interferes with normal sagittal balance and fails to maintain a straight posture with minimal energy. Therefore, the obesity can be an important factor in causing back pain by changing the lumbar lordosis. In this study, we will present an appropriate angle of incidence for obese people to reduce the image distortion of L4, L5 during a general anteroposterior radiography examination. To reduce image distortion according to the change of lordosis, the angle of incidence was applied 9 ° and 21 ° to L4 and L5 vertebra body when obesity and low back pain (LBP) perform the general anteroposterior radiography examination.

• 대한전기학회논문지:시스템및제어부문D
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• 제50권7호
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• pp.339-349
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• 2001

This paper suggests an optimal identification method for complex and nonlinear system modeling that is based on Fuzzy-Neural Networks(FNN). The proposed Hybrid Identification Algorithm is based on Yamakawa's FNN and uses the simplified inference as fuzzy inference method and Error Back Propagation Algorithm as learning rule. In this paper, the FNN modeling implements parameter identification using HCM algorithm and hybrid structure combined with two types of optimization theories for nonlinear systems. We use a HCM(Hard C-Means) clustering algorithm to find initial apexes of membership function. The parameters such as apexes of membership functions, learning rates, and momentum coefficients are adjusted using hybrid algorithm. The proposed hybrid identification algorithm is carried out using both a genetic algorithm and the improved complex method. Also, an aggregated objective function(performance index) with weighting factor is introduced to achieve a sound balance between approximation and generalization abilities of the model. According to the selection and adjustment of a weighting factor of an aggregate objective function which depends on the number of data and a certain degree of nonlinearity(distribution of I/O data), we show that it is available and effective to design an optimal FNN model structure with mutual balance and dependency between approximation and generalization abilities. To evaluate the performance of the proposed model, we use the time series data for gas furnace, the data of sewage treatment process and traffic route choice process.

• 한국환경보건학회지
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• 제33권4호
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• pp.255-263
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• 2007

Indoor air quality is the dominant contributor to total personal exposure because most people spend a majority of their time indoors. The purposes of this study were to evaluate the alternative method for improvement of indoor air quality in house after coating titanium dioxide ($TiO_2$) photocatalyst for interior part of the house using nitrogen dioxide ($NO_2$) multiple measurements. To evaluate the alternative method in indoor environment, daily indoor and outdoor $NO_2$ concentrations of an apartment and a detached house were daily measured for consecutive 21 days in winter and summer, respectively, Another daily 21 measurements were carried out after $TiO_2$ coating on wall paper of interior part in houses. All $NO_2$ concentrations were measured by passive filter badges. Indoor air quality models using mass balance are useful tool to quantify the relationship between indoor air pollution levels, ambient concentrations, and explanatory variables. Using a mass balance model and linear regression analysis, penetration factor (ventilation rate divided by sum of ventilation rate and decay rate) and source strength factor (emission rate divided by sum of ventilation rate and decay rate) were calculated. Subsequently, the decay constants were estimated. In this study. magnitude of improvement of indoor air quality could be evaluated by decay constant.

• 한국환경과학회지
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• 제13권7호
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• pp.645-653
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• 2004

Indoor air quality is affected by source strength of pollutants, ventilation rate, decay rate, outdoor level, and so on. Although technologies measuring these factors exist directly, direct measurements of all factors are not always practical in most field studies. The purpose of this study was to develop an alternative method to estimate these factors by application of multiple measurements. For the total duration of 30 days, daily indoor and outdoor $NO_2$ concentrations were measured in 30 houses in Brisbane, Australia, and for 21 days in 40 houses in Seoul, Korea, respectively. Using a box model by mass balance and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor (emission rate divided by sum of air exchange rate and deposition constant) were calculated, Sub-sequently, the ventilation and source strength were estimated. In Brisbane, the penetration factors were $0.59\pm0.14$ and they were unaffected by the presence of a gas range. During sampling period, geometric mean of natural ventilation was estimated to be $l.l0\pm1.5l$ ACH, assuming a residential $NO_2$ decay rate of 0.8 hr^{-1}$ in Brisbane. In Seoul, natural ventilation was $1.15\pm1.73$ ACH with residential $NO_2$ decay rate of 0.94 hr^{-1}$ Source strength of $NO_2$ in the houses with gas range $(12.7\pm9.8$ ppb/hr) were significantly higher than those in houses with an electric range $(2.8\pm2,6$ ppb/hr) in Brisbane. In Seoul, source strength in the houses with gas range were $l6.8\pm8.2$ ppb/hr. Conclusively, indoor air quality using box model by mass balance was effectively characterized.

• 대한영양사협회학술지
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• 제21권2호
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• pp.110-122
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• 2015

The purpose of this study was to investigate the correlation between food behavior and Attention Deficit Hyperactivity Disorder (ADHD) score in elementary students in Suwon-si, Gyeonggi-do. Two hundreds and thirty two students (113 male and 119 female) in grades 4~6 participated. We assessed food behavior by using Nutrition Quotient (NQ). NQ was examined by an NQ questionnaire, which consisted of 19 food behavior checklist items. Their items were grouped into five categories: balance, diversity, moderation, regularity, and practice. All data were statistically analyzed by SPSS 18.0. Among the five factors, NQ for food behavior and balance factor showed the lowest score, whereas that of diversity factor showed the highest score. The final Nutrition Quotient (NQ) score weighted on such five factors was 62.59 points. The average level of ADHD by Conners-Wells Adolescent Self-Report Scale (Short Form) [CASS(S)] was 17.02 points out of a total of 81 points. Six students (2.2%) who scored more than 41 points were classified as ADHD risk. By gender, male students (19.76 points) showed a higher CASS(S) score than female students (14.41 points) did. There was a significant negative correlation between NQ and CASS(S) score (r=-0.445, P<0.001). Multiple regression determined the effects of moderation ($Exp({\beta})=-0.193$, P<0.01) and practice ($Exp({\beta})=-0.345$, P<0.001) on CASS(S) score. In conclusion, distinctive nutritional education is needed for students with a high level of ADHD to help their understanding considering their different levels of attention.

• 한국환경보건학회지
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• 제23권3호
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• pp.56-65
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• 1997

Chemical analysis, statistical analysis and geochemical study were carried out to investigate the influence of the geology on the chemical characferistics of the mineral water in Taegu area. A simple comparision between the chemical components of the mineral water and their bedrocks indicates that the bedrock types in the catchmerit area control the chemical characteristics of the surface water. However more objective evidences for the mineral water-bedrock relationship come from the statistical analyses(cluster analysis and factor analysis). The results of the statistical analyses suggest that the bedrock type factor explains the data variation seven times as much as pollution does, which evidently indicates that the bedrock in the study area mainly control the mineral water chemistries. The results of comparision of the statistical analyses results with the mineral weathering reactions and mineral stability diagrams can be summarized as follows: 1. Plagioclase weathering to kaolinite provides SiO$_2$ , Ca$^{2+}$ and Na$^+$, and muscovite weathering to kaolinite provides K$^+$, and amphibole and mica minerals weathering to kaolinite provides F to the mineral water. Most of Ca$^{2+}$ and Mg$^{2+}$ in the mineral water are the products of carbonate mineral dissolution. SO$_4^{2-}$ may be the byproduct of sulfide oxidation. 2. The weatering of silicate mineral produces Ca-rich smectite and kaolinite, but Ca-rich smectite is unstable and will be transformed to more stable kaolinite because of the continuous dilution of the mineral water by precipitation. By Hashimoto's Mineral Balance Index, S-10 and S-12 mineral spring water were evaluated tasty and healthy water, S-9 and S-11 mineral spring water were evaluated tasty water and S-7, S-8 and S-13 mineral spring water were evaluated healthy water.

• Toxicological Research
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• 제24권2호
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• pp.101-107
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• 2008

Studies on hypoxia-signaling pathways have revealed novel Fe(II) and $\alpha$-ketoglutarate-dependent dioxygenases that hydroxylate prolyl or asparaginyl residues of a transactivator, Hypoxia-Inducible $Factor-\alpha(HIF-\alpha)$ protein. The recognition of these unprecedented dioxygenases has led to open a new paradigm that the hydroxylation mediates an instant post-translational modification of a protein in response to the changes in cellular concentrations of oxygen, reducing agents, or $\alpha$-ketoglutarate. Activity of $HIF-\alpha$ is repressed by two hydroxylases. One is $HIF-\alpha$ specific prolyl-hydroxylases, referred as prolyl-hydroxylase domain(PHD). The other is $HIF-\alpha$ specific asparaginyl-hydroxylase, referred as factor-inhibiting HIF-1(FIH-1). The facts (i) that many dioxygenases commonly use molecular oxygen and reducing agents during detoxification of xenobiotics, (ii) that detoxification reaction produces radicals and reactive oxygen species, and (iii) that activities of both PHD and FIH-1 are regulated by the changes in the balance between oxygen species and reducing agents, imply the possibility that the activity of $HIF-\alpha$ can be increased during detoxification process. The importance of $HIF-\alpha$ in cancer and ischemic diseases has been emphasized since its target genes mediate various hypoxic responses including angiogenesis, erythropoiesis, glycolysis, pH balance, metastasis, invasion and cell survival. Therefore, activators of PHDs and FIH-1 can be potential anticancer drugs which could reduce the activity of HIF, whereas inhibitors, for preventing ischemic diseases. This review highlights these novel dioxygenases, PHDs and FIH-1 as specific target against not only cancers but also ischemic diseases.

• 응용통계연구
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• 제29권5호
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• pp.987-998
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• 2016

자동차 보험은 치열한 시장경쟁과 금융당국의 요율 규제로 가격 조정에 합리적인 적용 방식이 요구되는 대표적인 보험상품이다. 특히 고령화 사회로 인한 인구변화와 가격경쟁으로 인한 요율 세분화는 보험료 결정에 주요한 요인으로 작용하게 된다. 따라서 본 논문에서는 여러 가지 요율 요소 중 연령에 대한 분포 추정을 통해 가격 최적화 방안을 제시하고자 한다. 미래 분포를 추정하는 방식으로 고객의 연령이동, 신규유입, 고객이탈 3가지 요인에 대한 최적화 방안을 적용함으로써 합리적인 연령 분포를 추정하여 가격 조정 과정에 반영하고자 한다. 기존 연령 분포를 적용한 보험료와 미래 연령 분포를 추정하여 적용한 보험료를 수지 불균등 원칙에 적용하여 위험도 추정에 대한 적정성을 비교 분석하는 것이 목적이다. 보험료 인상 또는 인하 문제와는 별개로 인구변화에 대한 적정 분포를 추정함으로써 가입자의 분포 변화로 인한 결손 또는 초과 이득이 발생하지 않는 적정 보험료 추정 방식을 제안하고자 한다.

• 한국유기농업학회지
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• 제20권1호
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• pp.21-36
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• 2012

In this study, the assessment of livestock manure nitrogen loading for recycling farming in Yeoju-Gun carried out comparing manure units based on the cultivation areas and the N-amount of manure that are generated from livestock manure. Manure units (MU) are used in the permitting, registration, because they allow equal standards for all animals based on manure nutrient production. An MU is calculated by multiplying the number of animals by manure unit factor for the specific type of animal. The manure unit factor for MU determination was determined by dividing amounts of manure N produced 80kg N/year. In this study, manure unit by nitrogen concentration and amount of animal manure was calculated as follows: Hanwoo multiplied by 0.36, dairy cows multiplied by 0.8. swine multiplied by 0.105. The laying hens and broilers multiplied by 0.0079, 0.0049, respectively. The analysis of liquid manure unit per ha shows that the N loading by LMU is quite different by region. When it comes to nitrogen loading, the LMU per ha of cultivated land in excess of the N-amount was the highest in the Bukne-myeon province with 2.76 MU/ha, which is higher than the appropriate level. The Ganam-myeon province came next with 2.53 LMU. To be utilized as a valid program to build the environmentally friendly agricultural system, diverse measures shall be mapped out to properly determine manure units, evaluate N-loading and to properly manage their nutrient balance of each region.