• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.91-91
• /
• 2018

해안 및 도서지역의 경우 다양한 목적으로 지하수를 개발하게 된다. 이러한 지역은 내륙의 담수와 해안의 바닷물이 대수층에서 만나게 되는데, 비중차이에 의해 섞이지 않고 해수-담수 경계면을 가지는 일정한 형태를 유지하게 된다. 하지만, 담수영역에 위치한 지하수개발관정의 과잉양수와 해수면 상승 등으로 인해 해수침투 길이가 길어지게 되어 기존 해안지역 지하수개발관정이 해수로 오염되는 경우가 발생한다. 해수침투로 오염된 대수층의 경우 회복까지는 오랜 시간이 소요되어 취수원으로 사용이 어렵게 된다. 국내외에서는 해수침투저감 방법에 대한 다양한 연구가 진행되고 있다. 대표적 해수침투 저감방법으로는 해수양수로 내륙으로 침투하는 해수를 제거하거나 담수 주입으로 침투 하는 해수를 밀어내게 된다. 또는 지하 차수벽 설치로 해수침투를 조절하기도 한다. 이러한 해수침투 저감방법들은 장단점을 가지고 있어, 적용지역에 적절한 해수침투 방법을 선정하는 것이 중요하다. 하지만 기존 해수침투 저감 방법의 경우 공통적으로 해수양수, 담수 주입을 위한 동력조달 혹은 차수벽 설치비용과 같이 경제적인 측면에 대한 고려가 부족하였다. 본 연구에서는 조위를 이용한 무동력 해수침투 저감 방법을 실험을 통해 연구하였다. 본 연구에서 제안한 방법은 기존 해수침투 저감방법과 비교해서 설치 및 운영비측면에서 장점이 있을 것으로 예상된다.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2019.01a
• /
• pp.409-410
• /
• 2019

본 논문에서는 국내 갑상선암의 연구 동향을 파악하기 위해 텍스트 중심의 접근법을 제안한다. 국내 갑상선암은 2000년대에 들어서며 발생이 급증하여 과잉진단의 논란을 불러일으켰으나, 다양한 분야의 자정 노력으로 수술 환자수가 크게 줄었다. 본 연구에서는 텍스트 마이닝 기술을 사용하여 디비피아에 등록되어 있는 갑상선암 관련 논문의 키워드와 초록을 수집하여 분석하였다. 1980년대는 대부분의 사례보고가 있었고 1990년대에 들어서면서 검진을 통한 조기 진단의 내용이 자주 나타났다. 2000년대에는 여러 장비들을 활용한 검사방법과 미세한 암의 발견에 대한 논의가 증가하였음을 확인 할 수 있었다. 2010년대에 들어서는 환자의 삶의 질에 대한 연구가 많이 이루어졌다. 지난 수십 년 동안 갑상선 암 연구 주제에 대해 뚜렷한 변화가 나타났으며, 향후 연구의 기초자료로 활용될 수 있으리라 기대된다.

• Korean Journal of Psychosomatic Medicine
• /
• v.19 no.2
• /
• pp.101-108
• /
• 2011

Objectives:We conduct this study to investigate the common features between Attention Deficit Hyperactivity Disorder(ADHD) and epileptic patients compared to normal control. Methods:Epileptic patients were recruited from the department of pediatic in Jesus Hospital. ADHD patients were recruited from the department of neuropsychiatry in Jesus Hospital. We excluded mental retardation or brain organic pathology. We use ADHD Diagnostic System and Korean-Child Behavior Checklist(K-CBCL) to assess features of ADHD. Electroencephalogram(EEG) of ADHD, epileptic patients and normal control were analyzed and compared. Results:Compared to normal control group, inattention, reaction time deviation were increased in both ADHD and epilepsy group. EEG abnormalities(control 13.8%, epilepsy 97.1%, ADHD 40%) in three groups were reported. Conclusion:There are common features of ADHD and epileptic patients.

• The Korean Journal of Applied Statistics
• /
• v.29 no.7
• /
• pp.1295-1309
• /
• 2016

This paper is to reproduce the result of Kim et al. (2014) by deriving a benchmark dose lower bound (BMDL) of lead based on the 2005 cohort data set of Children's Health and Environmental Research (CHEER) data set. The ADHD rating scales in the 2005 cohort were not consistent along the three follow-ups since two different ADHD rating scales were used in the cohort. We first unified the ADHD rating scales in the 2005 cohort by deriving a conversion formula using a penalized linear spline. We then constructed two linear mixed models for the 2005 cohort which reflected the longitudinal characteristics of the data set. The first model introduced the random intercept and the random slope terms and the second model assumed the first order autoregressive structure of the error term. Using these two models, we derived the BMDLs of lead and reconfirmed the "regression to the mean" nature of the ADHD score discovered by Kim et al. (2014). We also noticed that there was a definite difference between the sampling distributions of the two cohorts. As a result, taking this difference into account, we were able to obtain the consistent result with Kim et al. (2014).

• Journal of the Korean Geotechnical Society
• /
• v.31 no.1
• /
• pp.5-14
• /
• 2015

Seabed may undergo large excess pore water pressure in the case of long duration of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. Thus, it is necessary to develop a numerical technique which can precisely evaluate the dynamic response of seabed due to wave action. In this study, a new numerical technique named mixed model (2D NIT & FLIP models) was proposed. The dynamic wave pressure and water flow velocity acting on the boundary between seabed and the wave field was estimated using 2D-NIT model. This result was used as input data in FLIP program for investigation of dynamic response of seabed. To secure the reliability of the mixed model, the numerical analysis results of the mixed model were compared with Yamamoto's solution and Chang's experiment results. The comparison results indicated that there were some differences between them, but the general trend of the effective stress increment and the excess pore water pressure along the depth of seabed was similar to each other. Thus, this study clearly supports the plausibility of the numerical analysis of the mixed model.

• Journal of Nutrition and Health
• /
• v.48 no.5
• /
• pp.390-397
• /
• 2015

Purpose: In this study, we investigated the effects of chronic alcohol and excessive iron intake on mitochondrial DNA (mtDNA) damage and the progression of alcoholic liver injury in rats. Methods: Twenty-four Sprague-Dawley male rats were divided into four groups (Control, EtOH, Fe, and EtOH + Fe), and fed either control or ethanol (36% of total calories) liquid diet with or without 0.6% carbonyl iron for eight weeks. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, liver malondialdehyde concentrations were measured by colorimetric assays. Liver histopathology was examined by Hematoxylin-eosin staining of the fixed liver tissues. The integrity of the hepatic mtDNA and nuclear DNA was measured by long-range PCR. The gene expression levels of cytochrome c oxidase subunit 1 (Cox1) and NADH dehydrogenase subunit 4 (Nd4) were examined by real-time PCR. Results: Serum ALT and AST activities were significantly higher in the EtOH+Fe group, as compared to the Control group. Similarly, among four groups, liver histology showed the most severe lipid accumulation, inflammation, and necrosis in the EtOH + Fe group. PCR amplification of near-full-length (15.9 kb) mtDNA showed more than 50% loss of full-length product in the liver of the EtOH + Fe group, whereas amounts of PCR products of a nuclear DNA were unaffected. In addition, the changes in the mtDNA integrity showed correlation with reductions in the mRNA levels of mitochondrial gene Cox1 and Nd4. Conclusion: Our data suggested that the liver injury associated with excessive iron and alcohol intake involved mtDNA damage and corresponding mitochondrial dysfunction.

• The Korean Journal of Soil Zoology
• /
• v.5 no.2
• /
• pp.125-131
• /
• 2000

Disposing technique for dairy cattle manure using earthworms and the possibility of utilizing earthworms in poultry feed were investigated. In addition, chemical properties of manure and cast of earthworms were investigated. Temperature in the vinyl-house for earthworm nursery was able to be maintained above 0$\^{C}$ in winter and 25-28$\^{C}$ in summer. In closed-covering method, the number of escaped earthworms was the highest among three covering methods. The time was longer after manure excretion, the numbers of escaped earthworm were higher. There were some incidences of mortality of earthworm in closed-covering site. The amount of manure ingested by earthworm was increased in order of non-covering, closed-covering and gap-covering method. Fresh manure was more ingested than old one by earthworm. Earthworms reduced manure about 50% on the dry weight base and reduced total amounts of N, P$_2$O$\_$5/ and K$_2$O of manure by 41, 50 and 60%, respectively. Earthworm could be utilized by adult poultry (>60 g) for feeding. However, adverse effect of live earthworm was observed with young poultry (<450 g).

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.17 no.1
• /
• pp.51-59
• /
• 2006

Objectives : Present study compared the characteristics in Rorschach responses and Sandplay between ADHD and normal children group. Method : ADHD (excluded inattention type & emotional problem) group and normal group was composed of 10 children respectively. All of them were controlled by Intelligence Quotation. Rorschach responses were scored by Exner system and compared by t-test. For sandplay work, the time was measured and photo was taken. Results : 1) ADHD group showed that the reaction time in Rorschach was significantly fast and they easily failed to recall the responses. The statical significances are 3r+ (2)/R, X-%, Xu%, (2), AG, Afr, SCZI, Wsum 6, FD, Zd, Blends, a. 2) ADHD group showed that the reaction time in Sandplay was significantly fast, they used low materials (total numbers of toy, vehicles) and the work was less coordinated. Conclusion : This results suggest that ADHD children are apt to react, think and coordinate impulsively. Also, Sandplay could be used fur diagnostic method as Rorschach test.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.3
• /
• pp.493-504
• /
• 2017

We often observe count data that exhibit over-dispersion, originating from too many zeros, and under-dispersion, originating from too few zeros. To handle this types of problems, the zero-altered distribution model is designed by Ghosh and Kim in 2007. Their model can control both over-dispersion and under-dispersion with a single parameter, which had been impossible ever. The dispersion type depends on the sign of the parameter ${\delta}$ in zero-altered distribution. In this study, we demonstrate the role of the dispersion type parameter ${\delta}$ through the data of the number of births in Korea. Employing both the chi-square statistic and the Kolmogorov statistic for goodness-of-fit, we also explained any difference between the theoretical distribution and the observed one that exhibits either over-dispersion or under-dispersion. Finally this study shows whether the test statistics for goodness-of-fit show any similarity with the role of the dispersion type parameter ${\delta}$ or not.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.2 no.4
• /
• pp.39-47
• /
• 1982

Geotextile effects as reinforcement and vertical drain materials are studied through the laboratory model embankments on weak clays. The experiments are carried out in four stages; no woven fabrics between clay-crushed stone boundary, fabrics between boundary with no initial pretensioning of fabrics, and fabrics between boundary with two different initial pretensionings of fabrics. In all stages, vertical drains utilizing non-woven fabrics are installed in the clay layer in square pattern to accelarate the consolidation. The experimental model has plane dimensions of $32cm{\times}330cm$. The height for the clay container is 60 cm. The 47 cm height of crushed stone embankment is constructed over the 50 cm deep clay layer. The time dependent pore pressures are measured utilizing the 8 piezometers installed symmetrically on both sides of the wall at different heights. The time dependent deformations are measured utilizing the LED indicating lamp matrix inserted in the crushed stone embankment and the dialgauges put on top of the clay layer where the crushed stones are not laid. The measurements are carried out for 10 days which is equivalent to the time required for the primary consolidation. Through the experimental study, an analytical procedure is developed to predict the time dependent embankment settlement even if the top of the clay layer is reinforced with woven fabrics. This can be done through measuring the maximum pore pressures developed in the clay layer and comparing with the theoretical maximum pore pressures when no reinforcing fabrics are employed.