• Journal of Korean Elementary Science Education
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• v.43 no.1
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• pp.35-47
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• 2024

Thirty-five elementary schools in Gwangju and Jeollanam-do were surveyed on the installation status of plant labels. As a result of a comprehensive evaluation of the installation and condition of the plant labels, 12 out of 35 elementary schools were evaluated as "excellent," 13 as "good," and 8 as "insufficient." In some cases, various types of plant labels were installed on various types of plants and were updated continuously, indicating that the school members recognize the plant labels as an important educational tool. Meanwhile, some schools did not have a single plant label. Although plant labels were installed, instances occurred where they were neglected without continuous maintenance and management. Some plant labels were produced and installed by specialized companies, leading to errors in content or inadequate post-installation management, thereby compromising the school landscape. Therefore, we propose an alternative-allowing schools to independently produce and install plant labels. This approach preserves the school's uniqueness, and the process of producing and installing sustainable plant labels becomes an active educational tool.

• Journal of the Korean Society of Food Culture
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• v.15 no.1
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• pp.59-68
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• 2000

This survey investigated on the degree of acknowledgment, intake frequency and using methods of wild grasses of the residents in Kyeonggi, Kangwon, Chunnam, Chungbook, Kyeongnam & Cheju area. The results were as follows: 1. An answer that impression of wild grasses is 'nature food' was the highest(42.6%). It was founded that interest of nature food has been increasing. 2. It has been shown that the most common method for elimination of astringent taste is to blanch and then wash several times with water.(62.9%) 3. The most common obtaining routes was traditional market. It has been shown that rate of gathering in the fields is higher in rural community and the group of over 60 years old than that of urban community and the other groups. 4. In rural area, people(28.7%) ate wild grasses more frequently than in urban area. Family with the old and the group of over 40 years old eat wild grass often. 5. More than 95% of answerers were familiar with the names of wild grasses, codonopsis lanceolata, chinese bellflower, braken, mugwort, wild rocambole and edible shoots of a fatsia & Korean lettuce are known to them with over 88.6%, 85.1% respectively. Frequently eaten wild grasses were braken, chinese bellflower, wild tocambole, codonopsis lanceolata, mugwort and korean lettuce orderly. But in Chunnam & Kyeongnam, they were braken, chinese bellflower, mugwort, wild rocambole and Korean lettuce orderly. 6. Wild grasses eaten with rice were total 25 species, and mugwort had the highest usage rate with 41.9%. Mugwort was used for $D'{\breve{o}}k$(rice cake)(77.8%), T'wigim $J{\breve{o}}n$(deep fat fried dish swallow fat fried dish)(50.1%) and liquor(4.6%). In the cooking of Guk(soup), Chigae(stew), Sengch'ae(raw vegetable) and kinds of wild grasses for Namul(cooked seasonal vegetable) & Bokkum(saute) are the most various with 58 species, especially braken was most commonly used for saute. Sedum & Korean lettuce were the common ingredients of Kimch and codonopsis lanceolata was used in liquer & Jangachis(pickle) with 40%, 46% each. Chinese bellflower was used with the most variable cooking method. 7. 43 species of wild grasses were stored by blanching and drying, and braken had the highest rate(32.3%) then aster scaber, flowering fern, Pimpinella brachycarpa, mugwort and ligularia orderly.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.28-46
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• 2001

Natural gas is a mixture of hydrocarbon gases and impurities such as nitrogen, hydrogen sulfide, and carbon dioxide and a clean energy producing no pollution materials for combustion. Currently, the demand of the natural gas is rapidly increasing due to worldwide environmental problems. According to Hubbert's study in the past, the natural gas was predicted as rapidly depleted resources, and then the results led to high gas price and limitation of usage during 1980s. Afterward, the study of natural gas resources based on geology identified the additional natural gas resources that were not considered in Hubbert's study. They are unconventional gas, additional resources in the existed reservoirs, and natural gas in deep subsurface areas. Such additional resouces made the future of natural gas bright and pormised low and stable gas price in the future. Deep natural gas is defined as the gas existing at or below 15,000ft$(4,752{\cal}m)$ in depth from the surface. According to the study from the U.S. Geological Survey(USGS) in 1995, 1,412 TCF of technically recoverable natural gas was remained to be discovered or developed in the onshore of United States. A significant part of that resource base, 114 TCF, exists at deep sedimentary basins, and it shows wide distribution with various geological environments. In 1995, the deep gas contributed to $6.7\% of total supply amount of natural gas in the United States and is expected to be $18.7\% by 201.5. However, the development of the deep gas is a high risky business due to expensive investment and high portion of dry holes, although it is developed. Thus, for developing the deep gas economically, it is necessary to overcome many technical challenges. In this paper, for increasing success rate of the deep gas, 1) geologic and compositional characteristics, and production cost have been analyzed according to depth, 2) technical problems related to deep gas production have been summarized, and 3) finally future study areas for increasing application of the deep gas have been suggested. For reference, this paper was written based on the study results from USGS and Gas Research Institute(GRI), for the United States is doing the most active R&D in the deep gas area, and thus, has many reliable data.

• Economic and Environmental Geology
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• v.46 no.4
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• pp.291-300
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• 2013

The potential mineral resources in North Korea are magnesite, limestone, coal, graphite, iron, gold, silver, lead, and zinc. North Korea is mainly exporting coal and iron to China(70%) and EU countries. Gold ore reserves(or resources) in North Korea are about 2,000 tons and annual production is 2 tons based on metal. Major gold mines are Sooan, Holdong, and Daeyoodong mines and six smelters are operating. Fe ore reserves (or resources) are 4.3 billion tons and annual production is about 5 million tons based on 63.5% Fe. Major iron mines are Moosan, Leewon, Eunryul, Shinwon, and Jaeryong and 7 smelters are operating. Pb and Zn ore reserves(or resources) are Pb 470,000 tons and Zn 15 million tons, and annual productions are about Pb 26,000 tons and Zn 50,000 tons based on metal respectively. Major Pb-Zn mines are Gumdock and Seongcheon mines. Magnesite ore reserves(or resources) are 2.8 billion tons (95% MgO) and annual production is about 150,000 tons. Major magnesite mines are Ryongyang, Daeheung Youth and Ssangryong mines, and 5 magnesium refractory factories are operating. Apatite ore reserves(or resources) are 340 million tons(30% $P_2O_5$) and annual production is about 300,000 tons(crude ore). Major apatite mines are Daedaeri, Dongam and Poongnyen mines. Coal is established as an important strategic fuel mineral resources and is a major energy source in North Korea. Coal ore reserves(or resources) are 18.6 billion tons and annual production is about 20 million tons. The main coal fields is located in southern Pyongan and the Jigdong mine is the biggest in North Korea.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.565-578
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• 2000

The aim of this study was development of the Straight-Wire Appliance(SWA) suitable lot the treatment or Korean. To accomplish the object of this study, Korean adult with normal occlusion were selected with following criteria : 1) no functional abnormality in the craniofacial area, 2) good dental arch form and posterior occlusal relationship, 3) Angle Class I occlusal relationship, 4) no experience of orthodontic, nor prosthodontic treatment, especially, no dental treatment on labial and buccal surfaces of teeth, 5) good racial profile. Impression were taken for upper and lower dental arches or the selected normal occlusion samples and the orthodontic dental stone models were fabricated. 5 well-trained orthodontists had examined the acquired dental stone models to select study samples which satisfy the Six keys to optimal occlusion of Andrews. 155 pairs of dental stone models (92 pairs of Male, 63 of Female) were finally selected. 3 dimensional digitization were performed with the Coordinate Measuring Machine(CMM, MPC802, WEGU-Messtechnik, Germany) and measuring of Angulation, Inclination, In-and-Out, Molar offset angle and Arch form were accomplished with a measuring software to achieve data for the development of SWA. Before the measurement, error study was performed on the 3 dimensional digitization with CMM, and the analysis of reliability of computerized measuring method adapted in this study and conventional manual method Presented by Andrews was performed. Results of this study were as to)lows : 1. Equi-distance digitization with mesh size 0.25 mm, 0.5 mm and 1.0 mm were acceptable in 3 dimensional digitization of dental stone model with the CMM, and the digitization with 1.0 mm mesh size was recommendable in terms of efficiency. 2. Computerized measuring method with 3 dimensional digitization was more reliable than manual measuring method of Andrews. 3. Data were collected for the development of SWA suitable for the morphological characteristics of Korean with the computerized measuring method with 3 dimensional digitization.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.226-233
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• 2016

Purpose: The purpose of this study was to evaluate the adaptation of lithium disilicate crowns fabricated by CAD-CAM (computer aided design-computer aided manufacturing) and heat-press technique to compare two different measurement methods in assessing fit of the ceramic crowns: micro CT and cross-section technique. Materials and methods: A prepared typodont mandibular molar for ceramic crown was duplicated and ten dies were produced by milling the PMMA (polymethylmethacrylate) resin. Ten vinyl polysiloxane impressions were made and stone casts were produced. Five dies were used for IPS e.max Press crowns with heat-press technique. The other five dies were used for IPS e.max CAD crowns with CAD-CAM technique. Ten lithium disilicate crowns were cemented on the resin dies using zinc phosphate cement with finger pressure. The marginal and internal fits in central buccolingual plane were evaluated using a micro CT. Then the specimens were embedded and cross-sectioned and the marginal and internal fits were measured using scanning electronic microscope. The two measurement methods and two manufacturing methods were compared using Mann-Whitney U test (SPSS 22.0). Results: The marginal and internal fit values using micro CT and cross-section technique were similar, showing no significant differences. There were no significant differences in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique. Conclusion: Both micro CT and cross-section technique were acceptable methods in the evaluation of marginal and internal fit of lithium disilicate crown. There was no difference in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique except occlusal fit.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.19-25
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• 2015

Nowadays, CAD/CAM is broadly used in dentistry for inlays, crowns, implant abutments and its spectrum is expanding to complete dentures. Utilizing CAD/CAM to fabricate complete dentures is expected to decrease chair time and the number of visits, thus decreasing total fabrication time, expenses and errors caused during fabrication processes. One of the systems using CAD/CAM, DENTCA$^{TM}$ CAD/CAM denture (DENTCA Inc. Los Angeles, USA) scans edentulous impressions, designs dentures digitally, fabricates try-in dentures by 3D printing and converts them into final dentures. Patients can wear final dentures after only 2 - 3 visits with satisfying adaptation. This case report introduces a 71-year-old male patient who visited to consult remaking of existing old dentures. Residual teeth with bad prognosis and root remnants were extracted and the patient used reformed existing mandibular denture for 2 months. And then DENTCA system started. One-step border molding was done using conventional tray of adequate size provided by DENTCA system and wash impression was taken. Gothic arch tracing was completed based on the vertical dimension of existing dentures. Both maxillary and mandibular trays were placed to the resultant centric relation and bite registration was taken. Then DENTCA scanned the bite registration, arranged the teeth, completed the festooning and fabricated the try-in dentures by 3D printing. The try-in dentures were positioned, occlusal plane and occlusal relations were evaluated. The try-in dentures were converted to final dentures. To create bilateral balanced occlusion, occlusal adjustment was done after clinical remounting using facebow transfer. The result was satisfactory and it was confirmed by patient and operator.

• The korean journal of orthodontics
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• v.29 no.6 s.77
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• pp.649-661
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• 1999

The goals of this study were 1) to present pre-surgical naso-alveolar molding (PNAM) appliance for bilateral cleft lip and palate treatment and 2) to evaluate the effects of the PNAM appliance on the alveolar molding of the premaxilla and the lateral segments. Subjects consisted of 8 bilateral cleft lip and palate infants (7 males and 1 female, mean age at first visit = 61.6 days after birth) who were treated with PNAM appliances in Department of Orthodontics, Seoul National University Dental Hospital. Average alveolar cleft gap between the premaxilla and the lateral segment was $8.09{\pm}5.03mm$ and average duration of alveolar molding treatment was $8.8{\pm}3.1$ weeks. These patients' models were obtained at initial visit (T0) and after alveolar molding (T1). 20 linear and 14 angular variables were measured by using photometry and digital caliper, All statistical analyses were performed by Microsoft Excel 97 program. Paired t-test was used to discriminate the effect of alveolar molding by PNAM appliance. 1. Closure of the alveolar cleft gap in bilateral cleft cases by molding therapy was completed successfully, 2. Alveolar molding inhibited outward growth of lateral segments and produced inward bending of lateral segments. 3. By bending the anterior part of the vomer, the premaxilla could be rotated and moved. posteriorly via alveolar molding. Conclusion This appliance can be applied to bilateral cleft lip and palate infants with satisfactory results before cheiloplasty.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.327-333
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• 2009

In Korea chicken meat price is not determined in the auction markets, but it is artificially calculated using the live chicken price of one day before, transporting cost, converting rate of live chicken into carcass, and slaughtering cost. This calculated price is published through the mass media and used as the base for chicken meat transaction. By the way, since 85% of the Korean broiler industry is composed by the integrated system, the live chicken price is nothing to do with ex-factory price of chicken meat produced by the integrators. Under this pricing system, when we estimate the margin of the chicken meat through the marketing process, the margin of the integrator is fluctuated by the live chicken price of one day before, which is nothing to do with integrators; When the live chicken price is low, the margin of the integrators is low, but the margin of the selling agencies' is relatively high. On the contrast, when the live chicken price is high, the margin of the integrators is high, but the selling agencies' margin will be relatively low, because consumer's price could not be increased in parallel with increase of the live chicken price. Accordingly, the ex-factory price of chicken meat determined using the production cost of live chicken and slaughtering cost of the integrator by adding resonable margin of the integrator should be determined and published, so that it could be used for chicken meat transaction. In Japan the Zen-Noh Chicken Foods Corporation announce the ideal piece of chicken every morning, and all the transactions of the chicken meat will be determined based on this price. In Korea, it will be desirable to make bench marking from Japanese case, in other words the NH could announce the ideal price of chicken meat every morning, so that it would be the base price of chicken meat transaction. Even though the market share of the NH is less than 5%, its publicity should be accepted, since it is a subsidiary of the National Agricultural Cooperative Federation of Korea.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.73-82
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• 1989

The development of eggs and larvae, and minute scale-like tubercles on the skin surface of the larval Acanthorthodeus asmussi from Korea were observed in the laboratory. The egg was nearly ovoid-shaped. The number of egg averaged 195 per an oviposition. The morphological character of larval development was relatively similar to those of Acheilognathus tabira tabira, A. tabira subsp. (a), A. yamatsutae, A. moriokae, A. cyanostigma and A. rhombeus. The larvae of this species had many scale-like tubercles ellipsoided in a diagonal cross section on the skin surface of the body. And also this species moved like incessant wiggly movement pattern as that of fly maggot duing the larval development. As regards the tubercles and larval movement pattern, the larvae of A. asmussi shared similar characters with those of Acheilognathus rhombeus, A. longipinnis and Pseudoperilampus typos. Hence A. asmussi may be closely related to these species. The latter three species are autumn-spawning bitterlings and the larval development always retard in a certain stage, while A. asmussi is a spring-summer spawning species and the larval development never retards. Judging from these facts, it should be considered that there are close relations in evolutionary trend between the two spawning species.