• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.392-396
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• 2003

Purpose : The purpose of this study was to find the predictors for successful arthrocentesis for anterior disc displacement without reduction(ADD without Reduction) of the temporomandibular joint (TMJ). Patients and Methods : Arthrocentesis and lavage was carried out in 25TMJs of 22patients whose MRI findings were all anterior disc displacement without reduction. The effectiveness of the treatment was evaluated in terms of the postoperative range of maximal mouth opening (MMO) and the degree of postoperative pain score. Predectors which was analyzed were age, duration of painful locking, MMO, the degree of pain, perioperative clicking and the amounts of irrigation fluid. Results: 18cases (72%) was included to criteria for success. There were no significant differences in age, duration of locking, MMO and the degree of pain statistically. But In 15cases(83%) of successful cases, amouts of irrigated solution recovered to normal MMO were less than 150ml. And In 8cases (44%) of successful cases, perioperative clicking was appeared. Conclusion : Amounts of irrigated solution recovered to normal MMO and the appeareance of perioperative clkicking may be predictors of the successful results of arthrocenetesis of ADD without reduction of TMJ.

• Corrosion Science and Technology
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• v.21 no.5
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• pp.340-347
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• 2022

In this research, mixed metal oxide (TiO₂, RuO₂) coating was applied to grade 1 titanium as a bipolar plate for polymer electrolyte membrane fuel cell (PEMFC). Electrochemical experiments were carried out in an aqueous solution of pH 3 (H₂SO₄ + 0.1 ppm HF, 80 ℃) determined by DoE. The air was bubbled to simulate a cathode environment. Potentiodynamic polarization test revealed that corrosion current densities of the titanium substrate and MMO-coated specimen were 0.180 µA/cm² and 4.381 µA/cm², respectively. There was no active peak. After potentiostatic experiment, current densities of the titanium substrate and the MMO-coated specimen were 0.19 µA/cm² and 1.05 µA/cm², respectively. As a result of observing the surface before and after the potentiostatic experiment, cracked dried clay structures were observed without corrosion damage. Both the titanium substrate and the MMO-coated specimen could not satisfy the interfacial contact resistance suggested by the DoE. Thus, further research is needed before they could be applied as bipolar plates.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.4
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• pp.243-250
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• 2000

Selection of oat variety according to cultivation period is an important to increase productivity of forage crop. To investigate the growth characters and dry matter productivity of oats according to cultivation period, early-maturing oat(EM0) and medium-maturing oat(MM0) variety were sown in spring and autumn at central district of Korea. When oats were cultivated in spring, MMO variety was longer 8 cm in leaf length and wider 5 mm in leaf width than 25 cm and 12 mm of EM0 variety, rexpectively. but in autumn, those were not different between maturities of oat varieties. Plant length of MMO variety was longer 7 cm than that of EM0 Variety in spring cultivation, but in autumn, plant length of EM0 variety was longer 14 cm than that of MMO variety. Heading dates were 20th to 22th May in EM0 variety, and 30th May to 10th June in MMO variety in spring cultivation, and ear of EM0 variety emerged 30th Oct. to loth Nov. but that of MMO variety did not emerge at harvesting day in autumn cultivation. In Spring cultivation, dry matter(DM) yield of EM0 variety was 7,349 kg/ha that was less 56% than 11,466 kg/ha of MMO variety, but In Autumn, was more 15% than 6,575 kg/ha of MMO variety. In conclusion, selection of oat variety in spring and autumn cultivation can be different with cropping system of forage crop, and this trial is suggesting that oat variety could be sown MMO variety in spring and EM0 variety in autumn at central district of Korea. (Key words : Oat variety, Productivity, Cultivation season)

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.139-139
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• 2004

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.653-657
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• 2009

Nitrous oxide is a typical greenhouse gas which is produced from various organic or fossil fuel combustion processes as well as chemicals producing plants. $N_2O$ has a global worming potential of 310 times that of $CO_2$ on per molecule basis, and also acts as an ozone depleting material in the stratosphere. However, its removal is not easy for its chemical stability characteristics. Most SCR processes with several effective reducing agents generally require the operation temperature higher than $450^{\circ}C$, and the catalytic conversion becomes decreased significantly when NOx is present in the stream. Present experiments have been performed to obtain basic design data of actual application concerning the effects of $SO_2$ and $NH_3$ on the interim and long term activities of $N_2O$ reduction with CO over the mixed metal oxide (MMO) catalyst derived from a hydrotalcite-like compound precursor. The MMO catalysts used in the experiments, have shown prominent activities displaying full conversions of $N_2O$ near $200^{\circ}C$ when CO is introduced. The presence of $SO_2$ is considered to show no critical behavior as can be met in the $NH_3$ SCR DeNOx systems and the effect of $NH_3$ is considered to play as mere an impurity to share the active sites of the catalysts.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1652-1660
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• 2009

The main objective of this research is to build a behavior prediction model of gameplay for MMO (Massively Multiplayer Online) game using the GOMS analysis method. GOMS analysis is an observational approach to HCI(Human Computer Interaction) to model and predict behaviors of a human operator in a highly interactive task. In this research, a pilot experiment was previously conducted with three skilled gamers. The gamers were provided with the goals and operators through the user's guide book, and they found methods and selection rules while being observed. Based on the results obtained from the pilot study, this research was expanded and the model was further tested with 30 subjects (game experts). The new outcomes revealed that the relevance of GOMS analysis for predicting selection rules is 96.25% according to the degree of abstraction and 77.35% based on the degree of complexity. This research will provide game designers with a new testing mechanism in the early development stages, in order to improve the quality of the game product.

• Corrosion Science and Technology
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• v.14 no.4
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• pp.177-183
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• 2015

Prestressed Concrete steel Cylinder Pipe (PCCP) is extensively used as seawater pipes for cooling in nuclear power plants. The internal surface of PCCP is exposed to seawater, while the external surface is in direct contact with underground soil. Therefore, materials and strategies that would reduce the corrosion of its cylindrical steel body and external steel wiring need to be employed. To prevent against the failure of PCCP, operators provided a cathodic protection to the pre-stressing wires. The efficiency of cathodic protection is governed by the anodic performance of the system. A mixed metal oxide (MMO) electrode was developed to meet criteria of low over potential and high corrosion resistance. Increasing coating cycles improved the performance of the anode, but cycling should be minimized due to high materials cost. In this work, the effects of $RuCl_3$ concentration on the electrochemical properties and lifespan of MMO anode were evaluated. With increasing concentration of $RuCl_3$, the oxygen evolution potential lowered and polarization resistance were also reduced but demonstrated an increase in passive current density and oxygen evolution current density. To improve the electrochemical properties of the MMO anode, $RuCl_3$ concentration was increased. As a result, the number of required coating cycles were reduced substantially and the MMO anode achieved an excellent lifespan of over 80 years. Thus, we concluded that the relationship between $RuCl_3$ concentration and coating cycles can be summarized as follows: No. of coating cycle = 0.48*[$RuCl_3$ concentration, $M]^{-0.97}$.

• Archives of design research
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• v.19 no.2 s.64
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• pp.195-206
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• 2006

The computer game industry has managed to become the fastest growing segment of the entertainment industry nowadays. However, only a very low number of computer game products manage to cover the costs of production and generate earnings. According to traditional marketing wisdom, customers' preferences are a core issue in creating successful products, and the design process in game is crucial for guaranteeing garners' satisfaction. This research aimed to explore key design factors for the game design based on the new framework of the usability evaluation. We examined the usability in Massively Multi-player Online Role-playing Games (MMORPGs) and reviewed literatures related to games simultaneously. We identified eighteen usability issues in MMORPG and presented its recommendation relevant to the issues. Moreover, the results of the study showed fifty four key design factors composed of game interface, game play, game narrative, and game mechanics for the game design. The research is concluded with key implications to support the early stage of the design process in game.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.1
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• pp.15-20
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• 2019

Objectives: The aim of this study was to use four sets of success criteria to evaluate the outcomes of arthrocentesis treatment with hyaluronic acid injection in patients with internal derangement (ID) of the temporomandibular joint (TMJ). Materials and Methods: The study included 40 patients diagnosed with unilateral Wilkes stage III TMJ dysfunction. Clinical parameters, including maximum mouth opening (MMO) and pain during function, were evaluated preoperatively, 6 months, and 1 year after TMJ arthrocentesis. Outcomes were assessed and compared using four sets of success criteria from the following: the American Association of Oral and Maxillofacial Surgeons (AAOMS; MMO ${\geq}35mm$ and visual analogue scale [VAS] score ${\leq}3$), Murakami et al.'s criteria (MMO >38 mm and VAS score <2), Emshoff and Rudisch criteria (MMO ${\geq}35mm$ and >50% pain reduction), and patient self-reports (self-evaluation of treatment as successful or unsuccessful). Results: Significant improvements in MMO and pain reduction during function were observed between the preoperative period and 6 months and 1 year postoperatively (P<0.01). The success rates of treatment determined using AAOMS (52.5%), Emshoff and Rudisch criteria (57.5%), and self-reported patient criteria (40.0%) were similar. Application of the Murakami et al. criteria reported the lowest success rate (12.5%). Conclusion: The AAOMS and Emshoff and Rudisch criteria are consistent with patient expectations and can be used to assess treatment efficacy.

• Journal of Korea Game Society
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• v.20 no.5
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• pp.89-98
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• 2020

In MMO game servers, NUMA (Non-Uniform Memory Access) architecture is generally used to achieve high performance. Furthermore, such servers normally use hash tables as internal data structure which have constant time complexity for insert, delete, and search operations. In this study, we proposed a concurrent hash table optimized for NUMA system to make MMO game servers improve their performance. We tested our hash table on 4 socket NUMA system, and the hash table shows at most 100% speedup over another high-performance hash table.