• Journal of Korean Society of Environmental Engineers
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• v.39 no.1
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• pp.9-18
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• 2017

Arsenic (As) has been considered as the most toxic one among various hazardous materials and As contamination can be caused naturally and anthropogenically. Major forms of arsenic in groundwater are arsenite [(As(III)] and/or arsenate [(As(V)], depending on redox condition: arsenite and arsenate are predominant in reduced and oxidized environments, respectively. Because arsenite is much more toxic and mobile than arsenate, there have been a number of studies on the reduction of its toxicity through oxidation of As(III) to As(V). This study was initiated to develop photocatalytic oxidation process for treatment of groundwater contaminated with arsenite. The performance of two types of light sources (UV lamp and UV LED) was compared and the feasibility of goethite as a photocatalyst was evaluated. The highest removal efficiency of the process was achieved at a goethite dose of 0.05 g/L. Based on the comparison of oxidation efficiencies of arsenite between two light sources, the apparent performance of UV LED was inferior to that of UV lamp. However, when the results were appraised on the basis of their emitting UV irradiation, the higher performance was achieved by UV LED than by UV lamp. This study demonstrates that environmentally friendly process of goethite-catalytic photo-oxidation without any addition of foreign catalyst is feasible for the reduction of arsenite in groundwater containing naturally-occurring goethite. In addition, this study confirms that UV LED can be used in the photo-oxidation of arsenite as an alternative light source of UV lamp to remedy the drawbacks of UV lamp, such as long stabilization time, high electrical power consumption, short lifespan, and high heat output requiring large cooling facilities.

• Journal of Korean Society of Forest Science
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• v.80 no.1
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• pp.42-53
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• 1991

1. The forest vegetation of the Mt. Baek-Hwa situated in the northwestern Kyungsangpookdo of Korea, on $36^{\circ}16^{\prime}00^{{\prime}{\prime}}{\sim}36^{\circ}19^{\prime}20^{{\prime}{\prime}}N$ and 127 53'20"~127 56'30"E was studied by the method of Zurich-Montpellier School. In the present time, the original vegetation have almost been dominated by substitutional communities such as secondary forests of Pinus, Quercus, Zelkova, Acer or Fraxinus and Pinus rzgida plantations. Some secondary forests developing along the ravine and in northwestern part of slope are, however, maintained in natural condition, and contain some species of the original climax vegetation. They are classified as follows : I. Quercus mongolica-Fraxinus siebol diana community(Mountain forests), I-A. Acer pseudo-sieboldianum -Carex okamotoi group, I-B. Pinus densiflora group, I-B-a. Typical subgroup, I-B-b. Rhododendron schlippenbachii subgroup, II. Fraxinus rhynclzophylla-Acer mono community(Valley Forests), II-A. Acer pseudo-sieboldianum group, II-B. Zelkova serrata group, II-B-a. Typical subgroup, II-B-b. Lindera erythrocarpa subgroup, II-C. Querczrs serrata-Platycarya strobilacea group, II-C-a. Typical subgroup, II-C-b. Lindera erythrocarpa subgroup. 2. Judging from the coincidence method, the structure and distribution of the forest communities was more related to topography than altitude. 3. Considering the actual vegetation, relict species, occurrence of natural seedlings and saplings, climate, successional trends of trees and topographic or edaphic climax conditions, it seems that potential natural vegetation of the area mainly composed of Quercus mongolica, Carpinus laxiflora, Zelkova serrata, Fraxinus rhynchophylla. 4. The flora of the vascular plants collected from this area consists of 108 families, 371 genera, 613 species, 2 subspecies, 88 varieties, 6 forms and 709 taxa in total.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1293-1300
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• 2001

We surveyed dietitians'perception on usage of cook/chill vegetables, The questionnaires were distributed to 245 dietitians working in elementary schools and other institutions in Busan area. According to the survey, 75.9% of the dietitians perceived that minimally processed ready -to-use vegetal)toes would be helpful for the institutional foodservice They answered that problems of vegetable usage in the foodservice mainly come from long preparation time (45.4%), a large quantity of leftover (13.1%), and a high ratio of disuse (16.0%). Degree of preparedness from raw vegetables was highest for garlic, and was in tile order of platicodcm, onions, carrots, Potatoes, Korean cabbage and radish.40.9% of the dietitians answered that it was necessary Ic develop cook/chill vegetables in their institute restaurants. The high career group ( >6 yrs.) was, however, significantly (p<0.05) negative against the use of cooHchill vegetables. The dietitians were expecting that developing cook/chill vegetables would save cooking time and processes (4.43/5.00), and reduce waste (4.53/5.00) greatly. They also estimated that focal hygiene and quality would be improved, and labor cast be reduced moderately. On the other hand, they thought that the cost of flood would not be reduced.

• Journal of Korean Home Economics Education Association
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• v.18 no.3 s.41
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• pp.97-117
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• 2006

The purpose of this study was to investigate the teachers' recognition on the optimization of the educational contents of Clothing & Textiles in subjects of :he Practical Arts or the Technology & Home Economics in the course of elementary, middle and high schools. The statistical data for this research were collected from 203 questionnaires of teachers who work on elementary, middle and high schools. Mean. standard deviation, percentage were calculated using SPSS/WIN 12.0 program. Also. these materials were verified by t-test, One-way ANOVA and post verification Duncan. The results were as follows; First, The equipment ratio of practice laboratory were about 24% and very poor in elementary schools but those of middle and high school were 97% and 78% each and higher than elementary schools. Second, More than 50% of teachers recognized the amount of learning 'proper'. The elementary school teachers recognized the mount of learning in 'operating sewing machines' too heavy especially, the same as middle school teachers in 'making shorts': the same as high school teachers in 'making tablecloth and curtain' and 'making pillow cover or bag'. Third, All of the elementary, middle and high school teachers recognized the levels of total contents of clothing and textiles 'common'. The 80% of elementary school teachers recognized 'operating sewing machines' and 'making cushions' difficult especially. The same as middle school teachers in 'hand knitting handbag by crochet hoop needle', 'the various kinds of cloth' and 'making short pants'. The same as high school teachers in 'making tablecloth or curtain'. Fourth, Elementary school teachers recognized 'practicing basic hand needlework' and 'making pouch using hand needlework' important in the degree of educational contents importance. Middle school teachers recognized 'making short pants unimportant. High school teachers considered the contents focusing on practice such as 'making tablecloth and curtain' and 'making pillow cover or bags' unimportant. My suggestions were as follows; Both laboratories and facilities for practice should be established for making clothing and textiles lessons effective in Practical Arts in elementary schools. The 'operating sewing machines' which were considered difficult should be dealt in upper grade, re-conditioning to easier or omitted. The practical contents should be changed to student-activity-oriented and should be recomposed in order to familiar with students' living. It was needed to various and sufficient supports for increasing the teachers' practical abilities.

• Progress in Medical Physics
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• v.23 no.4
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• pp.309-316
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• 2012

Multimodal-imaging technique has been rapidly developed for improvement of diagnosis and evaluation of therapeutic effects. In despite of integrated hardware, registration accuracy was decreased due to a discrepancy between multimodal image and insufficiency of count in accordance with different acquisition method of each modality. The purpose of this study was to improve the PET image by event data resampling through analysis of data format, noise and statistical properties of small animal PET list data. Inveon PET listmode data was acquired as static data for 10 min after 60 min of 37 MBq/0.1 ml $^{18}F$-FDG injection via tail vein. Listmode data format was consist of packet containing 48 bit in which divided 8 bit header and 40 bit payload space. Realigned sinogram was generated from resampled event data of original listmode by using adjustment of LOR location, simple event magnification and nonparametric bootstrap. Sinogram was reconstructed for imaging using OSEM 2D algorithm with 16 subset and 4 iterations. Prompt coincidence was 13,940,707 count measured from PET data header and 13,936,687 count measured from analysis of list-event data. In simple event magnification of PET data, maximum was improved from 1.336 to 1.743, but noise was also increased. Resampling efficiency of PET data was assessed from de-noised and improved image by shift operation of payload value of sequential packet. Bootstrap resampling technique provides the PET image which noise and statistical properties was improved. List-event data resampling method would be aid to improve registration accuracy and early diagnosis efficiency.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.65-72
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• 2010

General anesthesia has been researched and developed in dentistry as on type of management technique to sedate patients who may be uncontrollable or require medical consideration. There has been continuous research into this area, but analysis of large set of patients over a sustained period of time is lacking. Thus, this study analyzes the records of patients who received general anesthesia at the Yonsei University Dental Hospital Department of Pediatric and Clinic for the Disabled. 1. Patient's age ranged from 1 to 66, with under 5 being the largest group with 410 members(38.5%). The study included more men than women, with 695 male members(65.3%). 2. Type of dental procedure performed were as follows(per person) : 5.6 Dental restoration; 2.3 Endodontic treatment of deciduous and primary teeth; 2.5 preformed crowning; and 1.6 extractions. Procedures took an average of 100 minutes. 3. 1022 patients(95.9%) received dental care under general anesthesia once and 43 patients(4.1%) received dental care under general anesthesia two or more times. Dentistry under general anesthesia has the many benefit. However, without appropriate post-treatment care, it is difficult to maintain good oral health. Therefore, it is important to improve the efficiency and safety of general anesthesia through future research.

• Korean Journal of Optics and Photonics
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• v.20 no.5
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• pp.266-271
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• 2009

We designed a thermo-optic switch based on a directional coupler with not only a high extinction ratio but also significantly low power consumption. The switch operates by using the thermo-optic effect of the polymer which the refractive index changes by heating the electrode. If the electrode is not powered (OFF), the input light will be coupled completely to the other waveguide. When the electrode is powered at a certain level (ON), input light launched into the input waveguide will remain in that waveguide due to the lower index adjusted in the other waveguide. The switch based on the directional coupler was designed using the generalized extinction ratio curve and the lateral shift of the input waveguide. The coupling length is 1,610 ${\mu}m$ and the extinction ratios are -28 and -30 dB for ON and OFF states, respectively. The electrode structures were optimized by thermal analysis. The transported heat into the waveguide is increased, as the electrode width (w) is increased and the center distance between the electrode and the waveguide (d) is decreased. Also, because the heat generated in the electrode affects the other waveguide, the temperature difference between two waveguides is varied as the given w and d. There are specific conditions which have the maximum of the temperature difference. That of the temperature difference is increased as the width and the temperature of the electrode are increased. Especially, when the switch is designed using the condition with the maximum of the temperature difference for switching, the temperature of the electrode can be decreased. We expect this condition will be the novel method for the reduction of the power consumption in a thermo-optic switch.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.377-384
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• 2007

Present tooth bonding system can be categorized into total etching bonding system (TE) and self-etching boding system (SE) based on their way of smear layer treatment. The purposes of this study were to compare the effectiveness between these two systems and to evaluate the effect of number of themocycling on microleakage of class V composite resin restorations. Total forty class V cavities were prepared on the single-rooted bovine teeth and were randomly divided into four experimental groups: two kinds of bonding system and another two kinds of thermocycling groups. Half of the cavities were filed with Z250 following the use of TE system, Single Bond and another twenty cavities were filled with Metafil and AQ Bond, SE system. All composite restoratives were cured using light curing unit (XL2500, 3M ESPE, St. Paul, MN, USA) for 40 seconds with a light intensity of $600mW/cm^2$. Teeth were stored in distilled water for one day at room temperature and were finished and polished with Sof-Lex system. Half of teeth were thermocycled 500 times and the other half were thermocycled 5,000 times between $5^{\circ}C$ and $55^{\circ}C$ for 30 second at each temperature. Teeth were isolated with two layers of nail varnish except the restoration surface and 1 mm surrounding margins. Electrical conductivity (${\mu}A$) was recorded in distilled water by electrochemical method. Microleakage scores were compared and analyzed using two-way ANOVA at 95% level. From this study, following results were obtained: There was no interaction between variables of bonding system and number of thermocycling (p = 0.485). Microleakage was not affected by the number of thermocycling either (p = 0.814). However, Composite restoration of Metafil and AQ Bond, SE bond system showed less microleakage than composite restoration of Z250 and Single Bond, TE bond system (p = 0.005).

• Journal of Chest Surgery
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• v.29 no.12
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• pp.1316-1322
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• 1996

From May 1977 to December 1994, 1.060 cases of open heart surge y for congenital heart disease were performed under cardiopulmonary bypass in Chonnam University Hospital They were divided into two groups; group A(677 cases, from May 1977 lo December 1989), group B(38B cases, from January 1990 to December 1994), to be compared and analized. Of the 1, 060 cases, there were 889 acyanotic (83.9%) and 171 cyanotic(16.1%). The operative mortality was 7.8% in group A and 5.7% in group B (total : 6.6%). The operative mortality for group A was 25% in cyanotic disease and 3.7% in acyanotic disease, respectively in group B, it was 23.8%, 3.2%. There were 19 patients (3.8%) and 78 patients(20.4%) with body weight under 10kg in group A and group B respectively. The operative mortality for these patients were 31.6% in A group and 16.1% in B group. In result, increasing trend in congenital heart disease in patients under 10 kg of body weight has been noted, whereas mortality has decreased. The operative mortality of tetralogy of Fallot has decreased in group B t an group A. These results suggest that the operative result have improved in recent years.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.481-489
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• 2005

Lonicerae Flos has antibacterial effects against Staphylococcus aureus, streptococci, pneumococci, Bacillus dysenterii, Salmonella typhi, and paratyphoid. It is an antiviral agent. The herb has a cytoprotective effect against $CCl_{4}-induced$ hepatic injury. It has antilipemic action, interfering with lipid absorption from the gut. Nowadays this herb is used mainly in the treatment of upper respiratory infections, such as tonsillitis and acute laryngitis. It is also used in the treatment of skin suppurations, such as carbuncles, and to treat viral conjunctivitis, influenza, pneumonia, and mastitis. Lonicerae Flos is dried flower buds of Lonicera japonica, L. hypoglauca, L. confusa, or L. dasystyla. But, for the most part, we use whole plant of Lonicera japonica, as a flower bud of it. And, little is known of the original copy of effects of whole plant, except for the 'Bon-Cho-Gang-Mok', which is written the effects of flower of Lonicera japonica are equal to effects of leaves and branch of it. The present study was conducted to evaluate the effect of flower and whole plant of Lonicera japonica on the regulatory mechanism of cytokines, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) for the immunological activities in Raw 264.7 cells. In Raw 264.7 cells stimulated with lipopolysaccharide (LPS) to mimic inflammation, flower and whole plant of Lonicera japonica water extracts inhibited nitric oxide production in a dose-dependent manner and abrogated iNOS and COX-2. Flower and whole plant of Lonicera japonica water extract did not affect on cell viability. To investigate the mechanism by which flower and whole plant of Lonicera japonica water extract inhibits iNOS and COX-2 gene expression, we examined the on phosphorylation of inhibitor ${\kappa}B{\alpha}$ and assessed production of $TNF-{\alpha}$, $interleukin-1{\beta}$ $(IL-1{\beta})$ and interleukin-6 (IL-6). Results provided evidence that flower and whole plant of Lonicera japonica inhibited the production of $IL-1{\beta}$, IL-6 and activated the phosphorylation of inhibitor ${\kappa}B{\alpha}$ in Raw 264.7 cells activated with LPS. These findings suggest that flower and whole plant of Lonicera japonica can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections, respectively.