• Journal of the Korean earth science society
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• v.30 no.1
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• pp.141-151
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• 2009

Inquiry has been emphasized in science classrooms, but the problems shown in the inquiry are somewhat different with ones that students usually meet and experience in everyday life. The purpose of this study is to investigate how attitudes toward the task and thinking skills affect students' problem solving process, especially, the way of creating a problem space and elaborating problem solving strategies when they have little schema. The difference in students' problem solving strategies of Lego Robotics class, one of the summer programs for $4^{th}-6^{th}$ grade gifted students, which is new to them, was investigated. The results are as follows: (1) The difference in attitudes toward the task, or selection and identification of the missions, and the perception of operators, affected creating a different problem space. (2) Different level of thinking skills, or analytical and flexible thinking, efficient elaborative skill, and application of schema affected a different level of elaboration of the problem space and resulted in asuccess rate of problem solving. (3) Different initial problem space resulted in different problem solving strategies. But without thinking skills, students could not elaborate problem solving strategies efficiently. Several instructional recommendations to promote scientific inquiry were suggested based on the results.

• Tuberculosis and Respiratory Diseases
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• v.43 no.5
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• pp.683-692
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• 1996

Background: Although most of the patients with tuberculous pleural effusions completely reabsorbed their effusions and became asymptomatic within 2 to 4 months, later surgical procedures such as decortication is needed in some patients because of dyspnea caused by pleural loculations and thickening despite anti-tuberculous chemotherapy. It is obligatory to secure adequate drainage to prevent the development of complications. But, the best methods for treating loculated tuberculous pleural effusions remain debatable. Recent several reports revealed that intrapleural instillation of fibrinolytic agents is an effective adjunct in the management of complicated empyema and may reduce the need of surgery. Purpose : The effects of catheterization with intrapleural urokinase instillation were prospectively evaluated in the patients with septated tuberculous pleural effusion, and compared with other therapeutic effects of different modalities of therapy such as repeated thoracentesis and small-bored catheterization. Methods : Forty-eight patients diagnosed with tuberculous pleurisy were randomly separated into three groups; control group(n=13), catheter group(n=12), urokinase group(n=22). In urokinase group, dose of 100.000U urokinase was instilled into the pleural cavity via a percutaneous drainage catheter for complete drainage or total dose of 700,000U of urokinase. After two hours clamping, the catheter was opened and intermittently irrigated. The early and late effectiveness of therapies was assessed by radiographically and by measuring the volume of fluid drained from the catheter. Results : There was statistically significantly better result in the urokinase group in respect of frequency of catheterization, frequency of catheter obstruction and the duration of catheterization in early effectiveness(p < 0.05). There were no difference in radiologic improvement of follow-up in later phase chest X-ray between urokinase group and catheter group in later phase(p > 0.05). But there were more failure rates in control group especially honeycomb septa in pleural effusion sonographically than former two groups. And there were no complications of urokinase such as fever or hemorrhage. Conclusion : In the treatment of septated tuberculous pleurisy, there were better results in urokinase than those of catheterization alone in early effectiveness. And there was no difference in radiographic improvement between urokinase group and catheter group. Intrapleural instillation of urokinase is an effective and safe mode of treatment for septated tuberculous pleural effusions and alleviates the need for thoracotomy.

• Clinical and Experimental Pediatrics
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• v.45 no.7
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• pp.884-890
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• 2002

Purpose : Henoch-Schonlein purpura(HSP) nephritis has been reported to vary from 25 to 50% among HSP patients and is a common cause of chronic glomerulonephritis in children. In our study, we evaluated the distribution and the association of the Insertion/Deletion(I/D) polymorphism of angiotensin converting enzyme(ACE) gene with clinical manifestations, particularly proteinuria in children with HSP nephritis, compared with that in HSP. Methods : ACE gene polymorphism was determined in children with HSP nephritis(n=33) and HSP(n=28) who were diagnosed in Busan Paik hospital from January 1996 to June 2001. The I/D polymorphism of ACE gene was determined by PCR amplication of genomic DNA. Results : The ACE I/D genotype frequency was DD : 25%, ID : 50%, II : 25% in HSP and DD : 24 %, ID : 46%, II : 30% in HSP nephritis, there was no significant difference in the genotype and allele frequencies between two groups. When statistical analysis was done according to the presence of D allele, the amount of 24-hour urinary protein excretion and the incidence of moderate to heavy proteinuria(>$500mg/m^2/day$) at onset and last follow-up were higher in DD/ID genotype than in those in II genotype, but these differences were not statistically significant. Conclusion : We suggest a lack of association between I/D polymorphism of ACE gene and clinical manifestations in children with HSP nephritis. However, further follow-up studies based on a sufficient number of patients and long term follow up periods are necessary to confirm the role of I/D polymorphism of ACE gene in children with HSP nephritis.

• Journal of the Korean Electrochemical Society
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• v.18 no.2
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• pp.51-57
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• 2015

We report the effect of the impurities including water and bromide in the propylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PMPyr-TFSI) on the electrochemical performance of lithium ion batteries. The several kinds of PMPyr-TFSI electrolytes with different amount of impurities are applied as the electrolyte to the cell with the high potential electrode, $LiNi_{0.5}Mn_{1.5}O_4$ spinel. It is found that the impurities in the electrolytes cause the detrimental effect on the cell performance by tracing the cycleability, voltage profile and Coulombic efficiency. Especially, the polarization and Coulombic efficiency go to worse by both impurities of water and bromide, but the cycleability was not highly influenced by bromide impurity unlike the water impurity.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.255-261
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• 1977

Using tracer technique of Zn-65, a pot experiment has been carried out in order to evaluate the efficiency of zinc fertilization on two paddy soils; an acidic from Kimpo and an alkaline from Yeongweol. The sources of zinc were zinc sulfate, zinc carbonate, zinc chloride and zinc oxide. Two rates of zinc were applied to the soils and control treatment was also included for this study. The methods of zinc application were uniform mixing throughout the soil, applying to the soil surface and irrigation water, and root dipping with zinc oxide at transplanting. In general, Yeongweol soil had higher efficiency of zinc fertilizers than Kimpo soil. The results showed that zinc fertilizer application should be required to improve the rice growing conditions in Yeongweol soil especially at early stage of growth after transplanting. As to the application method of zinc fertilizers, mixing treatment appeared to be most superior to any other methods in both soils. In addition, it is found that root dipping in the zinc oxide suspension would be a rather effective method of zinc application. In aspect of fertilizer efficiency there was no superiority or inferiority among the zinc sources used in this experiment.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.148-148
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• 2020

산업의 고도화가 진행됨에 따라 화학원료의 사용이 증가하고 있고 독성을 가진 화학물질이 하천으로 유입되는 사고가 빈번하게 발생하고 있다. 수환경으로 유입되는 유해화학물질은 주로 무색무취의 물질들로 사고가 발생하더라도 초기 발견이 어려워 어류폐사를 유발하거나 취수시설에서 용수로 취수되는 경우가 발생하기 때문에 이에 대한 대응책 마련이 필수적이다. 하천에 유입된 오염물질의 거동을 신속하게 예측하기 위해 1차원 오염물질 추적 모형이 활용되는데, Fickian 이송-분산 모형(Fickian Advection-dispersion equation model; FADE)이 주로 사용되고 있다. 하지만 FADE는 오염물질이 하천 저장대에서 지체되는 현상을 반영하지 못하기 때문에 농도곡선의 왜곡도를 구현하지 못하는 단점을 가지고 있다. 따라서 본 연구에서는 하천저장대모형(River Storage Model; RSM)을 개발하고 이를 국가하천인 감천에 적용하였다. 본 연구에서 개발한 RSM은 분산계수, 본류대 면적, 저장대 면적, 저장대 교환계수의 네 가지 매개변수를 통해서 하천의 물질 저장 및 교환 특성를 구현한 non-Fickian 모형으로서, 생화학반응, 휘발, 흡·탈착항을 추가하여 유해화학물질의 혼합 거동을 정확하게 모의할 수 있도록 개발하였다. 저장대 모형의 매개변수를 산정하기 위해서 하천 유량과 지형자료를 기반으로 HEC-RAS를 모의하여 계산된 수리특성을 입력변수로 사용하였다. 저수기, 평수기, 풍수기 유량을 기준으로 세 경우의 시나리오 모의를 수행하였는데, 5ton의 톨루엔이 김천산업단지에서 감천으로 유입된 경우 약 20km 하류에 위치한 취수장에서 톨루엔의 농도변화를 예측했다. 보존성 물질에 대한 모의 결과, 풍수기의 경우 저수기에 비해 유속이 크기 때문에 취수장에서 20.56시간 먼저 기준농도에 도달하고, 7.21시간 더 짧게 머무는 것으로 나타났다. 유해화학물질의 반응특성에 대한 민감도 분석을 시행한 결과, 생화학적 반감기가 18.98시간보다 길고, 옥탄올-물 분배계수가 2.267 이하인 물질은 생분해 및 흡·탈착 반응에 둔감한 것으로 나타났다. 1m 수심 기준 0.114m/s 이하 유속에서의 하천 수리조건에서는 화학물질의 휘발성을 무시할 수 있는 것으로 밝혀졌다.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.278-283
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• 2003

This study was carried out to examine the nitrogen removal rate of a subsurface-flow treatment wetland system which was constructed on floodplain of the Kwangju River from May to June 2001. Its dimensions were 29m in length, 9m in width and 0.65m in depth. A bottom layer of 45cm in depth was filled with crushed granite with about $15{\sim}30\;mm$ in diameter and a middle layer of 10cm in depth had pea pebbles with about 10 mm in diameter. An upper layer of 5 cm in depth contained course sand. Reeds (Phragmites australis) were transplanted on the surface of the system. They were dug out of natural wetlands and stems were cut at about 40 cm height from their bottom ends. Water of the Kwangju River flowed into it via a pipe by gravity flow and its effluent was funneled back into the river. The height of reed stems was 44.2 cm in July 2001 and 75.3cm in September 2001. The number of stems was increased from $80\;stems/m^2$ in July 2001 to $136\;stems/m^2$ in September 2001. Volume and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged 40.0 and $39.2\;m^3/day$, respectively. Hydraulic detention time was about 1.5 days. Average nitrogen uptake by reeds was $69.31\;N\;mg/m^2/day$. Removal rate of $NO_3-N$, $NH_3-N$, T-N averaged 195.58, 53.65, and $628.44\;mg/m^2/day$, respectively. Changes of $NO_3-N$ and $NH_3-N$ abatement rates were closely related to those of wetland temperatures. The lower removal rate of nitrogen species compared with that of subsurface-flow wetlands operating in North America could be attributed to the initial stage of the system and inclusion of two cold months into the six-month monitoring period. Increase of standing density of reeds within a few years will develop both root zones suitable for the nitrification of ammonia and surface layer substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increment in the nitrogen retention rate.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.40-48
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• 2009

Leading of the computer, IT technology has make great strides. As a information-industry-community was highly developed, user's needs to convenience about intelligence and humanization of interface is being increase today. Nowadays, researches with are related to BCI are progress put the application-technology development first in importance eliminating research about fountainhead technology with DB construction. These problems are due to a BCI-related research studies have not overcome the initial level, and not toward a systematic study. Brain wave are collected from subjects is a signal that the signal is appropriate and necessary in the experiment is difficult to distinguish. In addition, brain wave that it's not necessary to collect the experiment, serious eyes flicker, facial and body movements of an EMG and electrodes attached to the state, noise, vibration, etc. It is hard to collect accurate brain wave was caused by mixing disturbance wave in experiment on the environment. This movement, and the experiment of subject impact on the environment due to the mixing disturbance wave can cause that lowering cognitive and decline of efficiency when embodied BCI system. Therefore, in this paper, we propose an accurate and efficient brain-wave DB building system that more exactness and cognitive basis studies when embodied BCI system with brain-wave. For the minimize about brain wave DB with mixing disturbance, we propose a DB building method using an automatic control and prevent unnecessary action, put to use the subjects face tracking.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.56-68
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• 1997

This study was carried out to evaluate the capacity of environment purification of forest and to reveal formation processes of stream water quality by evaluating water quality variations in forest hydrological processes. Water quantity, pH, electric conductivity(EC), dissolved oxygen(DO), and dissolved matter concentrations were monitored in open rainfall, throughfall, stemflow, litter flow and short-term stream flow for one unit storm, and also for those were monitored in long-term stream flow in Palgong, Yongsung, and Daedong catchments. The results were summarized as follows; 1. pH and DO values of stream flow were increased as the flux increased but EC values were decreased. 2. pH values of stemflow and throughfall were decreased with the lapse of rainfall time with lower values than open rainfall. Arid EC values were higher in initial rainfall period but lower gradually with the lapse of time than open rainfall. In litter flow, pH values were lower than open rainfall but EC values were higher. In stream flow, pH values of stream flow showed a high level in initial rainfall period and decreased remarkably with the lapse of time, but it recovered after the rainfall stopped. And however, the values of EC showed almost reverse tendency. DO values of litter flow and stream flow were decreased gradually with the lapse of time in litter flow and stream flow but there were no any tendency in open rainfall, stemflow and throughfall. 3. pH values of stemflow and throughfall in Quercus acutissima were higher than in Pinus densiflora, but EC values were lower. Total amount of canons in stemflow was higher in Pinus densiflora than in Quercus acutissima. 4. pH, DO, EC and total amount of cation values in hydrological processes were in the order of; litter flow

• Korean Journal of Biological Psychiatry
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• v.15 no.1
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• pp.14-22
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• 2008

Objectives : The authors purposed to present data for explaining gene-environmental interaction causing depressive disorder by examining the effects of genetic factors related to the serotonin system and environmental factors such as stressful life events in early adulthood. Methods : The subjects were 150 young adults(mean age 25.0${\pm}$0.54), a part of 534 freshmen who had completed the previous study of genotyping of TPH1 gene. We assessed characteristics of life events, depression and anxiety scale and checked if they had a depressive disorder with DSM-IV SCID interview. Along with TPH1 A218C genotype confirmed in previous study, TPH2 -1463G/A and 5HTR2A -1438A/G genes were genotyped using the SNaPshot$^{TM}$ method. Results : In comparison with the group without C allele of TPH1 gene, the number of life events had a significant effect on the probability of depressive disorder in the group with C allele. Other alleles or genotypes did not have a significant effect on the causality of life events and depressive disorder. Conclusion : The results of this study suggest that TPH1 C allele is a significant predictor of onset of depressive disorder following environmental stress. It means that the TPH1 gene may affect the gene-environmental interaction of depressive disorder.