• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권6호
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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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• 제21권5호
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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.

• 한국초지조사료학회지
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• 제20권4호
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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)

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
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• pp.139-139
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• 2004

• 공업화학
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• 제20권6호
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• pp.653-657
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• 2009

아산화질소($N_2O$)는 각종 화학산업의 제조공정은 물론 유기 및 화석연료의 각종 연소공정으로부터 배출되는 대표적 온실가스이다. 온난화 효과는 $CO_2$의 310배에 달하고 성층권에 도달해서는 오존층을 파괴하는 물질이지만 화학적으로 매우 안정하여 분해처리가 쉽지 않다. 각종 환원제를 이용한 SCR 반응도 대부분 $450^{\circ}C$ 이상의 높은 온도를 요구하며 NOx 존재시에는 활성이 현저하게 떨어지는 문제점을 가지고 있다. 본 연구는 $N_2O$ 분해촉매의 실용화를 위한 기초연구로 진행되었으며, hydrotalcite형 화합물 전구체로부터 얻어진 혼합금속산화물촉매(MMO)와 CO 환원제를 이용한 $N_2O$ 분해에서 $SO_2$ 및 $NH_3$ 등 성분이 촉매의 반응성과 내구성에 미치는 영향을 실험적으로 분석하여 실용화에 대비한 기본 자료로 삼고자 하였다. 본 실험에 사용된 MMO 촉매는 CO 환원제와 같이 사용할 경우 $N_2O$ 분해 성능이 크게 향상되어 $200^{\circ}C$ 근처에서도 완전히 분해되는 것으로 나타났다. 또한 $NH_3$ SCR에 의한 NOx 분해반응의 경우와 달리 $SO_2$ 영향이 치명적으로 나타나지 않았고, $NH_3$에 의한 효과도 미미하여 촉매의 활성점을 공유하는 불순물 성분 정도의 영향에 불과한 것으로 판단되었다.

• 한국멀티미디어학회논문지
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• 제12권11호
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• pp.1652-1660
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• 2009

본 연구는 대규모 다중 사용자 온라인 게임에 관한 게임플레이 과정을 GOMS(Goal Operator Method Selection Rule)로 모형화 하는데 목적이 있다. GOMS 분석은 HCI(Human Computer Interaction)의 연구방법으로서 전문가의 행동을 모형화 하고 그들의 행동을 예측하는 것이다. 초보자 가이드와 온라인 게임 매뉴얼을 이용하여 GOMS의 목표, 작용소를 찾고 3명의 전문가를 대상으로 예비실험을 실시하여 GOMS의 방법과 선택규칙을 도출하였다. 예비실험결과를 토대로 30명의 전문 게이머들을 대상으로 본 실험을 실시하였다. 그 결과 게임 법칙에 대한 추상도 수준에 따른 법칙선택의 예측력은 96.25%, 제한사항의 복잡도에 따른 법칙선택의 예측력은 77.35%의 GOMS 모델 적합도가 산출 되었다. 본 연구에서 제안한 GOMS 모형은 게임을 설계하는 초기 단계에 새로운 평가 모형을 제시하며 게임의 품질을 향상할 수 있을 것으로 기대된다.

• Corrosion Science and Technology
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• 제14권4호
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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, $M]^{-0.97}$.

• 디자인학연구
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• 제19권2호
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• pp.195-206
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• 2006

컴퓨터 게임 산업의 급속한 성장에도 불구하고 대부분의 게임 타이틀들이 현격한 수익을 내지 못하는 실정이다. 기존마케팅 이론에 의하면 제품의 성공과 실패는 고객의 선호도, 필요, 기대에 대한 만족도에 의존한다고 한다. 역시 게임에서도 사용자의 만족을 극대화하기 위해서는 사용자들이 무엇을 원하고, 좋아할지를 파악하여 이를 게임에 반영할 필요가 있다 본 연구의 목표는 컴퓨터 게임의 사용성 평가를 위한 핵심 디자인 요인을 고찰하는데 있다. 본 연구는 기존의 게임 관련 문헌 고찰을 통하여 사용성 평가 핵심 디자인 요인을 도출하고 게임 플레이 과제와 사후 설문결과를 통하여 MMO (Massively Multi-player Online) 게임 사용성 평가를 실시하여 18가지 사용성 문제점과 그 권장사항을 제시하였다. 그 결과 게임 인터페이스, 게임 플레이, 게임 서사, 게임메커니즘으로 구성된 54 개의 사용성 평가 핵심 디자인 요인을 도출하고 MMO 게임을 위한 새로운 사용성 평가 체계를 개발하였다. 본 연구 결과는 MMO게임 디자인 프로세스의 초기 단계에서 효과적인 디자인 의사결정을 지원하고 게이머의 행동을 이해하는데 중요한 시사점을 제공 할 것으로 기대 된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권1호
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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.

• 한국게임학회 논문지
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• 제20권5호
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• pp.89-98
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• 2020

MMO 게임 서버에서는 성능을 높이기 위해 NUMA(Non-Uniform Memory Access) 구조를 사용해 하드웨어를 구성하는 경우가 많다. 또한 내부 자료구조로 삽입, 삭제와 탐색에 소요되는 시간이 짧은 해시 테이블과 같은 자료구조를 많이 사용한다. 본 논문은 NUMA 구조에 최적화된 해시 테이블을 제안하여, NUMA 시스템을 사용하는 게임 서버의 성능을 더 높일 수 있도록 한다. 제안된 해시 테이블을 4 소켓 NUMA 시스템에서 실험한 결과, 기존의 고성능 해시 테이블에 비해 최대 2배의 성능 향상을 확인할 수 있었다.