• Journal of the Korean earth science society
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• v.22 no.5
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• pp.360-376
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• 2001

This qualitative research investigated in-service science teachers' perceptions about cooperative learning and their perceived barriers in implementing cooperative learning in their classrooms. The underlying premise for cooperative learning is founded in constructivist epistemology. Cooperative learning (CL) is presented as an alternative frame to the current educational system which emphasizes content memorization and individual student performance through competition. An in-depth interview was conducted with 18 in-service science teachers who enrolled in the first-class teacher certification program during 2001 summer vacation. These secondary school teachers's interview data were analyzed and categorized into three areas: teachers' definition of cooperative learning, issues with implementing cooperative learning in classrooms, and teachers' and students' responses towards cooperative learning. Each of these areas are further subdivided into 10 themes: teachers' perceived meaning of cooperative learning, the importance of talk in learning, when to use cooperative learning, how to end a cooperative class, how to group students for cooperative learning, obstacles to implementing cooperative learning, students' reactions to cooperative learning, teachers' reasons for choosing (not choosing) student-centered approaches to learning/teaching, characteristics of teachers who use cooperative learning methods, and teachers' reasons for resisting cooperative learning. Detailed descriptions of the teachers' responses and discussion on each category are provided. For the development and implementation of CL in more classrooms, there should be changes and supports in the following five areas: (1) teachers have to examine their pedagogical beliefs toward constructivist perspectives, (2) teacher (re)education programs have to provide teachers with cooperative learning opportunities in methods courses, (3) students' understanding of their changed roles (4) supports in light of curriculum materials and instructional resources, (5) supports in terms of facilities and administrators. It's important to remember that cooperative learning is not a panacea for all instructional problems. It's only one way of teaching and learning, useful for specific kinds of teaching goals and especially relevant for classrooms with a wide mix of student academic skills. Suggestions for further research are also provided.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.247-261
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• 1999

Purpose: The aim of this study was to evaluate the normal values of regional cerebral blood flow (rCBF) and cerebrovascular reserve (CVR) in normal children to aged volunteers using Tc-99m HMPAO, Materials and Methods: Thirty four right-handed normal volunteers (20 males, 14 females, mean age $40.3{\pm}24.9$ years, range 4 to 82 years) were underwent rost/acetazolamide (ACZ) brain SPECT using Tc-99m HMPAO and the sequential injection and subtraction method. rCBF was estimated on the basis of a semiquantitative approach by means of right/left ratio, region/cerebellum and region to whole brain ratios in (rental, parietal, temporal, and occipital lobes, basal ganglia, thalami, and cerebellum. CVR was measured by means of % perfusion increase calculated as % mean count change compared to rest rCBF in each regions. Results: Mean values of right to left ratios range from 1.004 to 1.018, rCBF was highest in cerebellum and lowest in basal ganglia and thalami. Frontal and temporal rCBF decreased while occipital and thalamic rCBF increased according to age. No sexual difference of rCBF was noted. Mean CVR was $29.9{\pm}12.9%$. Mean CVR significantly increased to late teens, and declined thereafter. After 6th decade, CVR in both frontal lobes, left parietal lobe and right basal ganglia decreased significantly with advancing age. There was no sexual difference of CVR. Conclusion: Quantitative assessment of CVR was possible by ACZ Tc-99m HMPAO brain SPECT. It revealed that rCBF and CVR changed according to age in normal Korean volunteers. There was no sexual difference.

• Journal of Chest Surgery
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• v.30 no.10
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• pp.991-1000
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• 1997

Closed thoracostomy with UWSD* which is the most utilized procedure in chest surgery applies general thoracic disorders, trauma and after-thoracic surgery. The University hospital was involved on operating 2341 cases of closed thoracostomy with UWSD except chest tubing after-thoracic surgery for a full six years from January, 1991 to December, 1996. The rate of men and women out of the total 2341 cases was 3.5 : 1, the distribution by age showed that men were 36.6 $\pm21.0$ years old, women were $47.0\pm20.2$ years old and so that the total were 40.0 $\pm$ 20.5 years old. As for indication, spontaneous, secondary and traumatic pneumothorax were the most common, in addition to hemothorax hemopneumothorax, hydrothorax, hydropneumothorax, empyema, chylothorax. The most indwelling period of chest tubing is between eight and fourteen days for 974 cases and the average is 13.7 $\pm$ 6.3 days, The average drainage amount immediately after thoracostomy was 537 $\pm$ 88m1, and in 694 cases(46.0%), the drain amount was 201 ~ 500 ml. The rate of right and left tubing was 52.4 47.6, in 2071 cases(88.5%), the thoracostomy was the first chance and 2210 cases(94.4%) were treated with a single tube drainage. Almost all the patients complained of tube site pain, besides tube site infection, intercostal neuralgia, loss of tube function by the pleural adhesion, intrathoracic infection, incomplete reexpansion of defective lung, hemorrhage caused by the rupture of a blood vessel, subcutaneous emphysema, lung parenchymal rupture, diaphragmatic and intraabdominal trauma, reexpansionary pulmonary edema of one side lung and cellulitis were relapsed. 84.6% of all patients recovered with only clo ed thoracostomy and the rest of patient needed additional some necessary managements and so on to have successful results. There were two deaths(0.1%), caused by reexpansionary pulmonary edema, the cellulitis were complicated by thoracostomy with UWSD on an empyema patients to come to death(due to sepsis). t UWSD = under water seal drainage

• Journal of Nutrition and Health
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• v.14 no.2
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• pp.97-104
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• 1981

In order to study the changes of components and enzyme activities during Chungkookjang-Koji preparation, the Kojies were prepared with Bacillus Natto, Bacillus subtilis and traditional method. The temperature of Koji materials during Koji preparation was very different according to the experimental group. The content of ethyl alcohol, reducing sugar, amino nitrogen and water soluble nitrogen were changed by the Koji preparing stage and experimental group. Amylase and protease activities showed on irregular change on standing and their activities were not remarkably different among the groups and appeared weakly.

• Journal of the Korea Convergence Society
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• v.1 no.1
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• pp.41-47
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• 2010

This study was conducted to investigate determinent factors of the internet addiction that have influenced on middle school students. We randomly selected each one middle school in urban and rural areas, and conducted survey in 862 students of 2nd and 3rd grade from September 1 to 15, 2005. By using a statistical program called SPSS10.0, the data collected thereby were analyzed through a series of statistical methods including $x^2$-test, logistic regression analysis. The result of logistic regression analysis showed that the significant variables in urban area were resting time and using time a day. In rural area, sex, economic level, resting time and using time a day were significant variables. Higher status of internet addiction showed significant relationship with physical problems, anxiety, maladjustment to school, insufficient sleep time, fatigue in eyes, headache, pain in neck or shoulder, chronic fatigue, reduced vision, weight reduction, indigestion, xeroderma and adjustment to school. Especially, resting time and using time a day have dominant influence on internet addiction. And in case that the groups who showed high addiction tendency, there were negative health problem by physical, mental and social problem. To prevent internet addiction health education programs of right internet use and time, importance of rest, and health problems must be considered in internet addiction prevention policy.

• The Journal of Korean Academy of Sensory Integration
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• v.7 no.2
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• pp.23-35
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• 2009

Objective : The purpose of this study is to understand whether group Sensory Integration(SI) therapy has the effect on improvement of motor skill and social function for children with developmental disorder. Method : The subjects were recruited among children received sensory integration therapy at a Children's Development Institute in Dae-Jeon, experimental group is total 5 participating in group sensory integration therapy and control group is also 5 participating in individual sensory integration therapy. The program was constructed for 90 minutes and all children either in the experimental or in the control group went through intervention for 20 weeks. Bruininks-Oseretsky test of Motor Proficiency II, Korean-Scales of Independent Behavior-Revised and Social Maturity Scale were used in order to evaluate the degree of improvement in motor skill and social function. Results : Most children in the experimental group showed improvement in overall aspects of motor skill and the social function comparing pre-intervention with post-intervention, but they did not show any statistically significant differences. However, comparing experimental group with control group, children in the experimental group showed improvement in motor skill and social function. Furthermore, there is statistically significant improvement especially in manual coordination, manual dexterity, and social age and social quotient in Behavior-Revised and Social Maturity Scale. Conclusions : It is found that a group Sensory Integration therapy program has effect on motor skill and social function for children with developmental disorder in this study. In the future study, group SI therapy should be applied for children with diverse diagnosis in order to generalize the effectiveness of therapy.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.247-257
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• 2014

The construction of eight large weirs in the Nakdong River, Korea, caused a decrease in the water flow velocity and several physical changes to the water environment. Here, changes in phyto- and zooplankton communities and water quality in the areas near the eight weirs were investigated from 2011 to 2013, and relationships between phytoplankton abundances and environmental factors were analyzed. Special emphasis was given to the succession patterns in algal abundance based on temperature fluctuations. At the eight weirs, 24 dominant species were found. The most abundant phytoplankton species was Stephanodiscus sp. (39.4% of dominant frequency). Cyanobacteria of the genus Microcystis dominated during the summer, with an dominant frequency of 8.5% and cell abundance ratio of 36.6%. Significant correlations were observed between temperature and abundance of eight of the main dominant species; seven species showed positive correlations with temperature. Stephanodiscus sp., however, showed a negative correlation with temperature (r=-0.26, p<0.01). In addition, this species showed a significant negative correlation with the dominant algal species-Aulacoseira granulata and Aphanizomenon flos-aquae, with the zooplankton Copepoda and with Cladocera. On the contrary, seven other dominant species of algae showed significant positive correlations with zooplankton. Thus, we showed that the seasonal succession of plankton communities in the Nakdong River was related to the water temperature changes.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.10.3-11
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• 1982

Recently through the advancement of medical and surgical managements and the development of low pressure cuffed endotracheal tube, incidence of tracheal stenosis was decreased significantly. Though its incidence was decreased markedly, stenosis was developted unfortunately in the situations such as long term use of respirator, heavy infection, trauma of the trachea and long term intubation etc. Tracheal stenosis had been handled with various methods such as mechanical dilatation, tissue graft techniques, luminal augumentation and end to end anastomosis due to their individual advantages but their effects were not satisfactory. In 1959 Lester had been found the regenerated cartilage from the perichondrium of the rib incidentaly. Since then Skoog, Sohn and Ohlsen were reported chondrogenic potential of perichondrium through the animal experiments. Though many different materials have been tried to rebuild stenosis and gaping defect of trachea, tracheal reconstruction has been a perplexing clinical problems. We choose the perichondrium as the graft material because cartilage is the normal supporting matrix of that structure and it will be an obvious advantage to be able to position perichondrium over a defect and obtain new cartilage there. The young rabbits, which were selected as our experimental animals, were sacrified from two to eight weeks after surgery. The results of our experiment were as follows; 1) In control group, the defect site of trachea was covered with fibrosis and vessels but graft site was covered with hypertrophied perichondrium and vessels. 2) Respiratory mucosa was completely regenerated in defect sites both control and grafted groups. 3) The histologic changes of the grafted sites were as follows: 2 weeks- microvessel dilatation, inflammatory reaction, initiation of fibrosis 4 weeks- decreased microvessel engorgement, submucosal fibrosis, decreased inflammatory reaction immatured cartilage island was noted in the grafted perichondrium (one specimen) 6 weeks- mild degree vascular engorgement submucosal fibrosis. chronic inflamatory reaction cartilage island and endochondrial ossification was noted in the grafted perichondrium (Two specimens) 8 weeks- minute vascular engorgement dense submucosal fibrosis. loss of inflammatory reaction. cartilage island was noted in the grafted perichondrium (two specimens) 4) There was no significant differences in regeneration between active surface in and out groups. 5) We observed immatured cartilage islands and endochondrial ossification in the perichondrial grafted groups where as such findings were not noted in control groups except fibrosis. We concluded that perichondrium was the adequate material for the reconstruction of defected trachea but our results was not sufficient in the aspect of chondrogenic potential of perichondrium. So further research has indicated possibility of chondrogenic potential of perichondrium.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.17.1-17
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• 1982

In 1965, Rosenberg reported that platinum compounds not only inhibit growth and cell division of E. coli but also has anti-tumor activity. Since then, through animal and clinical experiments by Welsch(1971), Speer(1972), Rossof(1972), Hill(1974), and Wittes(1975), it was proved that Cis-platinum has excellent supressive effects on malignant tumor, especially on head and neck cancer. Accordingly, Cis-platinum is now widely used, sometimes without any other durg, or sometimes with Bleomycin and Methotrexate etc. Inspite of the strong anticancer effect, the use of Cis-platinum is quite often discouraged because of the reports that Cis-platinum causes auditory impairment at high frequencies above the speech range due to inner ear damage and irreversible change in the renal tubules. Since Kohonen et al(1965), Standnicki et al(1974) reported that Cisplatinum has toxic effects at the basal turn of the cochlea using guinea pig, many studies on ototoxicity after infusion of Cis-platinum have been carried out using animals. But the studies on ototoxicity in human beings can hardly be found except in reports by Piel et al(1974) and Hong et al (1979). So the authors did a study which tried to clarify the ototoxic effect by comparing the hearing level after infusion of Cis-plastinum with the hearing level before infusion of Cis-plastinum in 30 patients who was treated with Cis-platinum and admitted to the dept. of otolaryngology of Yonsei University Hospital during 2 years and a half from July. 1979 to March. 1982 and the following results were obtained. 1) The results of auditory evaluation, using the pure tone average, hearing loss of 4kHz and 8kHz, Speech Reception Threshold, PB score, SISI showed that the difference of dosage does not change the hearing level after infusion of Cis-platinum and before infusion of Cis-platinum. 2) Cis-platinum had no effect on the hearing level of patients with conductive hearing loss, or with sensorineural hearing loss, as well as with normal hearing level. 3) The infusion of Cis-platinum did not cause any change in creatinine clearance, creatinine, uric acid, but only one case showed that Cis-platinum caused severe nephrotoxicity. 4) The infusion of Cis-plastinum did not cause any change in hemoglobin, leukocyte count, platelet count and there was no correlation with the amount of infusion. 5) To see the side effect of hydration practiced with the infusion of Cis-platinum, the electrolytes, particularly the K level in the serum was measured. But the results did not show any change. 6) Judging from the results of this study mentioned above, ototoxicity caused by infusion of Cis-platinum can be prevented by sufficient hydration. Also the results might say that the appropriate method of infusion of Cis-platinum might be effective in the patients with head and neck cancer who had sensorineural hearing loss for whom the infusion of Cis-platinum has been absolutely cotraindicated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.167-173
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• 2002

This experiment was conducted to figure out the change of soil physical properties, rice growth and yield with the years of continuous cultivation in direct dry-seeding and no-tillage machine transplanting. Experiments were conducted at NHAES(National Honam Agricultural Experiment Station, RDA, Iksan, Cheon Buk Province, South Korea) with a rice variety "Dongjinbyeo" from 1995 to 2000. In no-tillage machine transplanting cultivation, organic matter in soil was higher than that on direct dry-seeding and was significantly high in topsoil. Problematic weed species were E. crus-galli B., A. keisak H., and L. japonica M. Plant height and tiller number m-2 were higher in common-tillage during the total growth duration. The highest weedy rice occurrence of 27.5% was observed in live years' continuous direct dry-seeding and followed by 6.2%, in four years', and 3.7%, in three years'. The highest yield reduction of 38% was observed in five years' continuous direct dry-seeding. The reduction may resulted from the competition between weedy rice and cultivated rice.