• Journal of the Korean Geotechnical Society
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• v.26 no.10
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• pp.61-68
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• 2010

A pilot-scale model test was performed to estimate the availability of new material, Fe-loaded zeolite, as the filling material in permeable reactive barrier (PRB) against the contaminated groundwater with both Cd and Cr(VI). Aquifer was simulated by filling up a large scale soil tank with sands, and mobilizing the water flow by the head difference of water level in both ends of the tank. Then, the mixture of concentrated Cd and Cr(VI) solution was injected into the aquifer to form a contaminant plume, and its behavior through Fe-loaded zeolite barrier was monitored. The test results showed that Fe-loaded zeolite barrier successfully treated the contaminant plume containing both Cd and Cr(VI) and that the immobilized contaminants in the barrier were not desorbed or released. The results indicated that the Fe-loaded zeolite could be a promising material in PRBs against the multiple contaminants with different ionic forms like Cr(VI) and Cd.

• The Korean Journal of Rehabilitation Nursing
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• v.6 no.2
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• pp.137-151
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• 2003

The purpose of this study was to develop a multidisciplinary team approach program for stroke survivors, and to identify its effects on their rehabilitation. The team was composed of 7 members: a rehabilitation nurse, a physician, a physical therapist, an occupational therapist, a therapeutic recreational therapist, a nutritionist, and a researcher. A quasi-experimental study was performed with 36 subjects: 18 in the experimental group and 18 in the control group, using a noneqivalent control group pretest-posttest design. The experimental group participated 4 times in rehabilitation programsfocused on information and emotional support provided by the rehabilation team-and received telephone counseling from the researcher. The control group did not receive any treatment. The selection criteria for the subjects in this study were: (a) patients who were diagnosed as having had an ischemic stroke within the last year, (b) patients free of any communication disorder, (c) and those having a primary caregiver who could assist in filling out the form assessing the level of ADL. The data were collected from patients who had been discharged from a tertiary hospital, between October 1st, 1999 and September 30th, 2000. The data were analysed by $X^2$ test, Fisher's exact test, ANCOVA, Wilcoxon's rank sum test, and Wilcoxon's signed rank test using an SAS program. The results were as follows: 1. In terms of physical variables (blood pressure, grasp power, and ADL) 1) There was a significant difference in blood pressure between the two groups (systolic pressure P= .012, diastolic pressure P= .050). 2) There was also a significant difference in grasp power between the two groups (affected side : P= .012, unaffected side : P= .010). 3) There was no significant change in the level of ADL between the two groups. 2. In terms of psychosocial variables (depression, self-efficacy, self-esteem, and social activities) 1) There were no significant differences between the two groups. However, all four psychosocial variables showed a tendency to improve in the experimental group, while only two variables (depression and self-efficacy) showed a simalar tendency in the control group. 2) The level of social activities in the control group decreased significantly after a month (P= .050). 3. The level of life satisfaction improved in both groups, but no significant difference was found. Stroke has high recurrence rate and requires considerable follow-up care. The program used in this study was developed and designed for stimulting the rehabilitation process of stroke survivors. Through the program period of one month (meetings were held weekly), a positive effect was detected in physical variables, although the psychosocial variables did not improve significantly. In retrospect, a one month period may not be an adequate length of time to improve the psychosocial variables, as the stroke survivors were complicated cases, and most of them were elderly. Further research is therefore recommended by increasing the length of program, so that its effect can be more noticeable.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.199-208
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• 2010

To investigate a comparison of rice yield and quality between organic and conventional cultivation, study for occurrence of rice diseases carried out in rice (Oryza sativa L.) field of Noahn and Bannam region. The results obtained as following: 1) Bactericide and insecticide were applied twice and four times at Noahn and Bannam region in conventional cultivation (C.C) of rice field, respectively, it was applied twice at two region in organic cultivation (O.C). Rice strip virus, leaf blast, neck blast, sheath blight, bacterial leaf blight, rice water weevil, rice leaf folder, and plant hoppers were occurred mainly in rice field. Leaf blast, neck blast, and rice leaf folder were occurred highly at O.C compared with C.C. 2) Growth level of rice in clum and panicle length was lower at O.C than C.C. Number of panicles per hill was by 0.6 higher at O.C than C.C. Number of panicles per hill was by 0.6 higher at O.C than C.C in Noahn region. Number of spikelets per panicle, grain filling ratio, brown/rough rice ratio, and weight of 1,000 grains was lower at O.C than C.C. Number of panicles per hill was by 0.8 lower at O.C than C.C in Bannam region. Number of spikelets per panicle and grain filling ratio was higher at O.C than C.C while brown/rough rice ratio was lower at O.C. Total yield percentage of rice in O.C was level of 84% at Noahn region and 94% at Bannam region compared with C.C. 3) Head rice percentage was lower at in O.C than C.C at two region. Protein and palatability (Toyo value) were lower at O.C than C.C in Bannam region causing occurrence of neck blast and rice leaf folder by oversupply of nitrogen fertilizer. Protein, whiteness, and palatability (Toyo value) were adequate level at O.C in Noahn region by lower nitrogen fertilizer.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.4
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• pp.365-373
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• 2016

Composites are the most useful restorative material. However, composites have some disadvantages such as polymerization shrinkage, long working time, and susceptibility to water and contamination, which are stood out more especially when treating children. To solve these problems, bulk-fill composites have been developed. The aim of this study is to compare mechanical properties of bulk-fill and conventional composites. Bulk-fill composites (SureFil SDR flow (SDR), Tetric N-Ceram bulk fill (TBF)) and conventional composites (Filtek Z-350 (Z-350), Unifil Flow (UF), Unifil Loflo Plus (UL)) were used. The Vickers hardness tester was used to measure the microhardness of materials, and Fourier transform infrared spectroscopy was used to measure the degree of conversion. Polymerization shrinkage was measured by using a linometer. Flexural and compressive properties were measured by using the universal testing machine. Data were statistically analyzed by ANOVA and Scheffe's post hoc test. The level of significance was set to p < 0.05. Most conventional composites showed higher microhardness than bulk-fill composites. However, bulk-fill composites showed a higher top/bottom microhardness ratio than conventional composites. Bulk-fill composites showed a higher top/bottom degree of conversion ratio than conventional composites. The polymerization shrinkage was highest in UL and lowest in Z-350. The polymerization shrinkage of flowable composites was higher than that of non flowable composites. The compressive properties were highest in Z-350 and lowest in SDR and UL. In terms of flexural properties, Z-350 was the highest. However, none of the bulk-fill composites exhibited mechanical properties as good as those of conventional composites. Nonetheless, the ratio of microhardness and degree of conversion, which are important properties of bulk filling, were higher in bulk-fill composites. Therefore, the bulk-fill composites might be considered suitable restorative materials in pediatric dentistry.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.307-327
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• 2008

Geochemical study on the rocks and minerals of the Gyeongju low and intermediate level waste repository was carried out in order to provide geochemical data for the safety assessment and geochemical modeling. Polarized microscopy, X-ray diffraction method, chemical analysis for the major and trace elements, scanning electron microscopy(SEM), and stable isotope analysis were applied. Fracture zones are locally developed with various degrees of alteration in the study area. The study area is mainly composed of granodiorite and diorite and their relation is gradational in the field. However, they could be easily distinguished by their chemical property. The granodiorite showed higher $SiO_2$ content and lower MgO and $Fe_2O_3$ contents than the diorite. Variation trends of the major elements of the granodiorite and diorite were plotted on the same line according to the increase of $SiO_2$ content suggesting that they were differentiated from the same magma. Spatial distribution of the various elements showed that the diorite region had lower $SiO_2,\;Al_2O_3,\;Na_2O\;and\;K_2O$ contents, and higher CaO, $Fe_2O_3$ contents than the granodiorite region. Especially, because the differences in the CaO and $Na_2O$ distribution were most distinct and their trends were reciprocal, the chemical variation of the plagioclase of the granitic rocks was the main parameter of the chemical variation of the host rocks in the study area. Identified fracture-filling minerals from the drill core were montmorillonite, zeolite minerals, chlorite, illite, calcite and pyrite. Especially pyrite and laumontite, which are known as indicating minerals of hydrothermal alteration, were widely distributed in the study area indicating that the study area was affected by mineralization and/or hydrothermal alteration. Sulfur isotope analysis for the pyrite and oxygen-hydrogen stable isotope analysis for the clay minerals indicated that they were originated from the magma. Therefore, it is considered that the fracture-filling minerals from the study area were affected by the hydrothermal solution as well as the simply water-rock interaction.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.3
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• pp.227-239
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• 2008

Processing LiDAR (Light Detection And Ranging) data obtained from ALS (Airborne Laser Scanning) systems mainly involves organization and segmentation of the data for 3D object modeling and mapping purposes. The ALS systems are viable and becoming more mature technology in various applications. ALS technology requires complex integration of optics, opto-mechanics and electronics in the multi-sensor components, Le. data captured from GPS, INS and laser scanner. In this study, digital image processing techniques mainly were implemented to gray level coded image of the LiDAR data for building extraction and superstructures segmentation. One of the advantages to use gray level image is easy to apply various existing digital image processing algorithms. Gridding and quantization of the raw LiDAR data into limited gray level might introduce smoothing effect and loss of the detail information. However, smoothed surface data that are more suitable for surface patch segmentation and modeling could be obtained by the quantization of the height values. The building boundaries were precisely extracted by the robust edge detection operator and regularized with shape constraints. As for segmentation of the roof structures, basically region growing based and gap filling segmentation methods were implemented. The results present that various image processing methods are applicable to extract buildings and to segment surface patches of the superstructures on the roofs. Finally, conceptual methodology for extracting characteristic information to reconstruct roof shapes was proposed. Statistical and geometric properties were utilized to segment and model superstructures. The simulation results show that segmentation of the roof surface patches and modeling were possible with the proposed method.

• Journal of the Korean Institute of Gas
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• v.16 no.2
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• pp.25-30
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• 2012

This paper presents a stress safety of a composite pressure cylinder in which is composed of an aluminum liner and composite layers with carbon fiber/epoxy and glass fiber/epoxy resigns. The composite pressure cylinder for a hydrogen gas vehicle contains 9.2 liter hydrogen gas, and hydrogen gases are compressed by a filling pressure of 35MPa. The FEM computed results are analyzed based on the US DOT-CFFC basic requirement for a hydrogen gas cylinder and KS B ISO specification. The FEM results indicate that the stress, 247MPa of an aluminum liner is sufficiently low compared with that of 272MPa, which is 95% level of a yield stress for aluminum. And, the carbon fiber composite layers in which are wound on the surface of an aluminum cylinder are safe because the maximum carbon fiber stresses from 29.43% to 28.87% in hoop and helical directions are below 30% for a given minimum required burst pressure level, respectively. The carbon fiber composite layers are also safe because the stress ratios from 3.40 to 3.46 in hoop and helical directions are above 2.4 for a minimum safety level, respectively.

• Journal of the Korean Geotechnical Society
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• v.37 no.4
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• pp.19-26
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• 2021

The high-level radioactive waste (HLW) produced from nuclear power plants is disposed in a rock-mass at a depth of hundreds meters below the ground level. Since HLW is very dangerous to human being, it must be disposed of safely by the engineered barrier system (EBS). The EBS consists of a disposal canister, backfill material, buffer material, and so on. When the components of EBS are installed, gaps inevitably exist not only between the rock-mass and buffer material but also between the canister and buffer material. The gap can reduce water-retarding capacity and heat release efficiency of the buffer material, so it is necessary to investigate properties of gap-filling materials and to analyze gap spacing effect. Furthermore, there has been few researches considering domestic disposal system compared to overseas researches. In this reason, this research derived the peak temperature of the bentonite buffer material considering domestic disposal system based on the numerical analysis. The gap between the canister and buffer material had a minor effect on the peak temperature of the bentonite buffer material, but there was 40% difference of the peak temperature of the bentonite buffer material because of the gap existence between the buffer material and rock mass.

• Journal of Chest Surgery
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• v.13 no.3
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• pp.243-249
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• 1980

Truncus ateriosus is one of the cyanotic congenital heart disease. The incidence is relatively uncommon, as 0.4% of totoal congenital heart disease. Embryologically the defect is due to a lack of partitioning of the embryonic truncus and conus during the first few weeks of fetal life. The ventricular septal defect is invariable present. A single arterial vessel arises from the heart and supplies blood to the aorta, the lung, and the coronary arteries. In 1949, collett and Edwards classified this defect according to anatomic variation to four major types, such as type I, II, III, and IV. Type IV is defined that pulmonary arteries are absent, and the pulmonary arterial supply arises from the descending thoracic aorta. This patients often have a continuous murmur head particularly well in the interscapular area. No effective surgical treatment is available. We have experienced one case of truncus arteriosus, type IV of Collett and Edwards in the Department of Thoracic and Cardiovascular Surgery, Kyungbook National University Hospital. This patient was 10 year-old girl. The chief complaints were cyanosis and dyspnea on exertion since birth. She was admitted at this hospital on April 16, 1980. The continous machinery murmur was heard loudest at the interscapular area. The chest X-ray films revealed cardiomegaly with an increase in pulmonaryvascular markings. The pulmonary secotr was significantly concave. No filling of pulmonary arteries noticed by the right ventriculogram. There was possible biventricular hypertrophy in EKG. The echocardiogram showed that the demension of the aortic root was larger than normal and minimal increase of the left ventricular internal dimension. The cardiac catheterization data was obtained by use of the great saphenus vein approach. The systolic pressure of the right ventricular outflow tract was 80 mmHg and was similar to that of the aorta. The oxygen saturation data revealed the evidence of the left to right shunt at the level of ventricular septum. The patient was operated and the diagnosis was confirmed as trucus arteriosus, type IV. No effective surgical interventins were performed.

• Journal of the Korean Chemical Society
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• v.45 no.1
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• pp.83-89
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• 2001

This study was to examine middle school students' understanding of dissolution. More than 75% students understood that dissolution was caused by small particles' filling the space between large particles due to the difference of size among particles. Some other students responded that solute disappeared or was absorbed in a solvent as the result of dissolution. Besides, they didn't know that space between particles was the reason of the volume's decreasing after the process of dissolution. Instead, they explained that space between particles caused dissolution. And they hardly understood the fact that solutes affect solubility. Students'misunderstanding about the concept of dissolution resulted from the lack of the explanation on the right concept of dissolution in science textbooks and the inappropriate use of the dissolution model by teachers. In conclusion, we need the appropriate explanation in middle school science textbooks that consider the students'level and the development of the appropriate model that demonstrates dissolution in the perspective of particles.