• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.2
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• pp.91-99
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• 2023

Background: Extrusion of debris is a major factor that results in postoperative pain during root canal treatment with various instruments and instrumentation techniques. Therefore, instrumentation techniques that extrude minimal debris into the periapical area while reducing pain are desirable. This study aimed to compare the incidence of postoperative pain and intake of analgesic medication (frequency and quantity) after endodontic treatment of mandibular posterior teeth using two single files and full-sequence continuous rotary systems with different kinematic motions. Methods: Thirty-five of 105 patients were assigned equally to three groups according to the instrumentation system used: ProTaper Next (PN) X2, 25/06 (Dentsply, Maillefer, Ballaigues, Switzerland), One Shape (OS), #0.25/06 (Micro Mega, Besancon, France), and Wave One Gold (WG), Red - #0.25, 0.07 (Dentsply, Maillefer, Ballaigues, Switzerland). Five specialists were included in this study design; each professional prepared 21 teeth, and randomly selected 7 per instrument system. The VAS sheet ranging from 0 to 10 was used to record the initial and postoperative pains at 24, 48, and 72 h, and 7^th day after single visit endodontic treatment in mandibular premolars and molars with a diagnosis of asymptomatic irreversible pulpitis with or without apical periodontitis. Postoperatively, an analgesic, ibuprofen 400 mg was administered for intolerable pain at a dose of 1 tablet for 6 h. The patients were asked over the telephone regarding postoperative pain at intervals of 24, 48, and 72 h, and 7^th day using a visual analogue scale. Result: There were no statistically significant differences among the PN, OS, and WG systems (P > 0.05) with regard to the incidence of postoperative pain at any of the four time points assessed. Conclusion: The intensity of postoperative pain, frequency, and analgesic intake were similar across all three types of instrument systems; however, the reciprocating single file (WG) was associated with less postoperative pain than the full sequence continuous rotary file.

• Land and Housing Review
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• v.2 no.4
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• pp.415-427
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• 2011

This study is aiming at estimating the demolition cost of deterioration housing by the rational method in order to provide for the demolition and new build project of the rental multi-family housing of LH. We investigated the actual state of demolition construction and work process of small size housing, and analysed an actual condition of estimation for the demolition cost through an advice by the expert of construction cost estimate. Furthermore, the 'estimation standard for the predetermined amount', 'estimation standard for the disposal cost of construction wastes' and precedent studies in public construction work were considered. As one of results in this study, cost accounting system, breakdown system and construction cost for the demolition work based on the standard of estimate were proposed and the predetermined amount of demolition construction for the multi-family housing with 2 or 3 floors could be produced by them. Eventually, It is estimated that the demolition cost per a multi-family housing is about 18,331,000(won) and 104,000(won) per floorage($m^2$). To the details, the result indicated that the direct demolition cost needs about 14,339,000(won) per a multi-family housing and the consignment disposal cost of wastes needs 3,992,000(won) per one. The results of the study will be used as the fundamental data to estimate the project cost in the phase of budget establishment for demolition and new build project of the deteriorated rental multi-family housings, and also cost accounting system of demolition construction and breakdown system are expect to be used effectively at the ordering of public construction work.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.763-769
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• 2018

In this research, in order to improve the heat retention of greenhouse, comparative analysis of the heat flux of the marketed multi-later insulating curtain was carried out. Experiments is conducted by fabricating a test apparatus for investigating the heat flux characteristics. The multi-later insulating curtain used for the experiment was compared using the P, N, S, U and T company, which are commercially available, and the heat flux due to temperature difference between the experimental apparatus and the outside was compared and analyzed. When the internal temperature of the experimental result is the maximum temperature $60^{\circ}C$, the heat flux of multi-later insulating curtain is T Co.($73.1W/m^2$) > S Co.($119.5W/m^2$) > U Co.($155W/m^2$) > N Co.($163.1W/m^2$) > P Co.($177.7W/m^2$). The heat flux means the quantity of heat passing through the unit time per unit area, and the higher the numerical value, the higher the quantity of heat passing through the multi-layer insulating curtain. This can be determined that high heat fluxes produce low heat resistance. Further, it has been found that the weight of the insulating curtain is largely unrelated to the heat insulating property, and the heat insulating curtain having a thickness containing a high internal air layer is excellent in the heat insulating property. In the future when manufacturing a heat insulating curtain, It is judged that it is desirable to manufacture a combination of heat insulating materials that contain a high internal air layer content and that can maintain the air layer even for long-term use while minimizing the volume.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.183-191
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• 2011

The objective of this study is 10 investigate the method to produce urban climate map so as to cope with climate change and efficiently control greenhouse gas in the city by using GIS. To produce urban climate map by using GIS, statistical data and spatial data of greenhouse gases related to climate change were collected and analyzed and the correlation between the type of urban climatop and urban climate change was analyzed by establishing GIS framework data construction method to prepare urban climate map and preparing and analyzing urban climate map related to the demonstration area. It was found that exact greenhouse gases emission quantity and absorption quantity can be calculated for each type of urban climatop by preparing urban climate map and the temperature is high in residential area, commercial area and industrial area and the emission quantity per unit area is high in the traffic area and industrial area. It seems that the influence of climate change can be presented for urban development by suggesting urban climate change for type of urban climatop and they can be utilized to save energy in urban area and to establish greenhouse gases reducing policy.

• Korean Journal of Construction Engineering and Management
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• v.11 no.3
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• pp.125-133
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• 2010

Although work-efficiency of construction machinery is a critical factor for estimating its workable-quantity perunit time, the efficiency figure table presented in the Poom-Sam that is used for Construction Cost Estimation of public sectors in Korea is very subjective for practical usage. In order to suggest objective work-efficiency table for a Pump-Dredger, domestic and overseas documentary records were investigated and on-going construction sites were also visited. Moreover, actual work quantities collected from the site visits were compared with the ones calculated based on the Standard Measurement Methods used in Japan. The research found that the table can be revised by means of detailing down by several factors, namely project type, depth of soil, undersea-site shape, and condition on the sea for better estimation of its workable-quantity. The research will be the foundation for applying the rapid development of Construction Equipment and technology to the appropriate cost estimations and the ground work of related studies.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.25-25
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• 2023

As the demand for processing potatoes increases, imports of raw potatoes and potato products are increasing, so it is necessary to expand potato production as raw materials for processing in Korea. Potato varieties for processing that can be grown in fall have been developed, but research on cultivation technology and processing quality management technology to improve chip processing quality is very insufficient. Therefore, this study was conducted to investigate the optimal harvest time by investigating the quantity and chipping characteristics of potato chips during autumn cultivation. As the test varieties, the chip processing varieties "Saebong", "Eunsun", and "Geumnaru" were used, and the potato cultivation site was the Seocheon-gun Test field (214 Gaeya-ri) of the Chungcheongnam-do. The test treatment was at harvest time after spring cultivation, and the potatoes were harvested at 70, 80, 90, and 100 days after sowing based on the sowing time. The investigation items were potato productivity (total yield, yield of standard processing, and number of tubers) and chip-processing characteristics (chip color, dry matter content, glucose content, etc.). As a result of examining the yield characteristics according to the harvest time, statistical significance was not found according to the treatment. The total yield (ton/ha) was 27.5 to 30.5, and there was no significant difference depending on the time of 70 to 100 days after harvest. The standard quantity for processing (yield of 81-250g potatoes per unit) also showed a similar trend. In chipping characteristics according to harvest time, statistical significance was high in specific gravity and glucose content. The specific gravity was highest at 1.077 at 70 days after harvest, and the glucose (mg/dL) content was the lowest at 37.5 at 80 days after harvest. Statistical significance was not recognized, but chip color (L value) was the highest at 64.4 at 70 days after harvest. Therefore, it is judged that the optimal harvesting time for chip processing is 70 to 80 days after sowing.

• Fire Science and Engineering
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• v.34 no.1
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• pp.11-17
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• 2020

As performance-based design (PBD) has a direct impact on evacuation safety assessments, designing fire scenarios based on real fire tests is essential. To improve the reliability of the PBD for fire safety in multiplexes, information on fire behavior, such as heat release rate (HRR) and fire spread rate, are provided in this study by conducting a standard fabric flammability test. To this end, several chairs were arranged in a pattern that resembled a theater-style seating. The peak HRR and heating value per unit mass for each chair ranged from 415 kW to 988 kW and 15.2 MJ/kg to 23.8 MJ/kg, respectively. The heating values per unit mass of the new and old chairs were 23.6 MJ/kg and 16.7 MJ/kg, respectively. As the quantity of plastic and cushioning materials in the new chairs was more than that of the old ones, the new chairs were more vulnerable to fire hazards. Furthermore, when the chairs were arranged in a line, the fire spread rate was observed to be 0.39-0.42 m/min, regardless of the ignition location. Finally, a fire growth curve showing the peak HRR and fire spread rate was also demonstrated.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.91-98
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• 1999

The content of taxol and related compounds in needle and stem tissues of exotic yews growing in the Chollipo Arboretum which located in the West Sea of Korea were determined by HPLC. A considerable variation in contents of taxol and the related compounds within species and among cultivars were observed. The content of taxol was much higher in the needles than those in the young stem tissues except T. X media cv. Vermuleun, T. baccata cv. Washingtonii, and T. X cuspidata cv. Nana, and the content of 10-deacetyl baccatin III(10-DAB III) was also slightly higher in the needle. The needle of T. cuspidata cv. Nigra collected from April was contained the high amount of taxol(1,027 ${\mu}g$ per g dry weight) and also contained high quantity in 10-DAB III(267 ${\mu}g$ per g dry weight). Concentration of taxol in needle was significantly greater than those of meristemic and ovary tissues, Exotic yews growing at the Chollipo Arboretum containing T. cuspidata cv. Nigra could be suitable materials as a source for the tissue and cell cultures for production of taxol.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.3
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• pp.184-193
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• 2008

For environment-friendly fishery, the lead sinkers of octopus drift line were developed with the environmentfriendly sinker, and their characteristics and performance were investigated. To make the environmentfriendly sinker, the hydrate ceramic material was developed, and to increase the weight and strength, the iron power was added to it. The fishing hook was machine-made, and standardized, by using 60cm iron wire. For the manufacture of the sinker, the first, the mold was made, and then, hydrate ceramic material and water were quantitatively mixed. The mixture was poured into the mold prepared with a fishing hook already inserted, and had hardened for several hour, before it was taken out of the mold as a complete sinker. The sinkers were made in the 8 types ranging in weight from 150 to 500g, and their specific gravities were diverse from 2.871 to 6.637, which was 0.19 to 0.44 times lower than that of lead. The movement of the environment-friendly sinker by flume tank was possible in the weaker current speed than the similar lead sinker. In the coastal fishing grounds of Gangwon province, the comparison of catching efficiency was made between the improved fishing gears composed of the environment-friendly sinkers and artificial baits, and the current used fishing gears of lead sinkers and pig-fat baits. The result showed the tendency in which the improved fishing gears caught the bigger octopuses than the current used fishing gears. In the quantity and number of the fish catch per unit fishing gear, the improved fishing gear showed a little more catch than the current used fishing gear, regardless of the fishing area. However, the number of the improved fishing gears lost during fishing operation was similar to that of the current used fishing gears.

• Journal of Pharmaceutical Investigation
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• v.17 no.3
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• pp.111-126
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• 1987

Methyl methacrylate-butyl methacrylate copolymer (MMBM)-dibutyl phthalate (DBP) films were investigated as a potential topical drug delivery system for the controlled release of nitrofurazone. The kinetic analysis of release data indicated that drug release followed a diffusion-controlled granular matrix model, where the quantity released per unit area is proportional to the square root of time. DBP of several hydrophobic plasticizers selected was found to give the highest release of nitrofurazone. However, hydrophilic plasticizers such as propylene glycol and polyethylene glycol 400 had no controlled release properties and acceptable film formation. The effects of changes in film composition, drug concentration, film thickness, pH of release medium, and temperature on the in vitro release of nitrofurazone were analyzed both theoretically and experimentally. The release rate constant (k') was found to be proportional to DBP content, pH, and the temperature of release medium, but independent of film thickness, and drug concentration in a range of 0.1-0.4% by weight. The linear relationship was found to exist between the log k' and DBP content. The release of nitrofurazone from MMBM-DBP (8:2) films was found to be an energy-linked process. Two energy terms were calculated ; the activation energy for matrix diffusion was 13.45 kcal/mole, and the heat of drug crystal solvation was 27.26-29.34 kcal/mole. Observation of scanning electron micrographs and microscopic photographs showed that the incorporation of DBP in films increased markedly the particle size of nitrofurazone dispersed in the film matrix, comparing with the fine dispersion of nitrofurazone in pure MMBM film alone.