• 전자공학회논문지
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• 제50권1호
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• pp.239-245
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• 2013

발전소 내 고압 단자대 및 전력구 케이블 인입부에서 주변 전력기기들의 지속적인 진동 및 순간적인 충격의 발생으로 케이블 단자 또는 접속부 접촉점에 열화가 발생하는 사고가 일어난다. 접촉점에서의 열화 발생은 큰 사고로 이어질 수 있으며 안정적으로 전력을 공급해야 하는 발전소에서는 열화 발생을 예측하기 위한 다양한 연구가 시도되고 있다. 이에 비접촉식 적외선 센서를 이용하여 온도를 측정하는 방식이 있으며 이러한 방식의 궁극적인 목적은 측정하고자 하는 대상체를 최적의 거리에서 감시함으로 접촉점의 열화 발생뿐 아니라 센서 측정범위 내의 열화의 상태도 감시하는 데 있다. 연결부 온도를 측정하고 열화 상태를 실시간 감시하여 사용자에게 가시, 가청 알람을 주어 사용자가 열화사고를 인지하여 미연에 방지할 수 있게 한다. 그러나 이러한 시스템을 구축하기 위해서는 감시 장치를 설치, 운영해야 하는 어려움이 있다. 본 연구에서는 설치 용이성을 고려하여 소출력 배터리 동작모듈로 접속부의 온도를 측정하고 이를 감시할 수 있는 적외선센서를 이용한 무선감시시스템을 개발하였다.

• The Journal of Advanced Prosthodontics
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• 제7권1호
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• pp.21-26
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• 2015

PURPOSE. To evaluate the cytotoxicity of temporary luting cements on bovine dental pulp-derived cells (bDPCs). MATERIALS AND METHODS. Four different temporary cements were tested: Rely X Temp E (3M ESPE), Ultratemp (Ultradent), GC Fuji Temp (GC), and Rely X Temp NE (3M ESPE). The materials were prepared as discs and incubated in Dulbecco's modified eagle's culture medium (DMEM) for 72 hours according to ISO 10993-5. A real-time cell analyzer was used to determine cell vitality. After seeding $200{\mu}L$ of the cell suspensions into the wells of a 96-well plate, the bDPCs were cured with bioactive components released by the test materials and observed every 15 minutes for 98 hours. One-way ANOVA and Tukey-Kramer tests were used to analyze the results of the proliferation experiments. RESULTS. All tested temporary cements showed significant decreases in the bDPCs index. Rely X Temp E, GC Fuji Temp, and Rely X Temp NE were severely toxic at both time points (24 and 72 hours) (P<.001). When the cells were exposed to media by Ultratemp, the cell viability was similar to that of the control at 24 hours (P>.05); however, the cell viability was significantly reduced at 72 hours (P<.001). Light and scanning electron microscopy examination confirmed these results. CONCLUSION. The cytotoxic effects of temporary cements on pulpal tissue should be evaluated when choosing cement for luting provisional restorations.

• 한국게임학회 논문지
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• 제15권2호
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• pp.95-104
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• 2015

행맨, 크로스퍼즐, 매칭등과 같은 많은 영어 단어 학습용 게임들이 보드 형태 또는 컴퓨터 게임 형태로 개발되었다. 이들 컴퓨터 게임 대부분은 전략형 게임 플레이를 채택하기에 이런 스타일의 게임을 좋아하지 않는 학습자들에게는 게임의 고유 특성인 즐거움을 주는데 한계가 있다. 본 논문에서는 청소년 및 성인 대상의 1인용 자동차 주행 게임을 중심으로 새로운 영어 단어 암기를 위한 시스템을 제안한다. 본 시스템의 핵심인 자동차 주행 게임에서 학습자는 차를 운전하면서, 트랙 상에 아이템처럼 나타나는 영어 단어 텍스트와 충돌하여서 점수를 획득하게 된다. 학습자는 화면상에 노출된 영어 단어를 주행 중에 지속적으로 보면서, 영어 단어를 뇌리에 새기게 된다. 우리의 실험 결과, 우리의 게임을 통한 영어 단어의 기억 효과는 만족할 수준이고, 학습 도구로서의 본 시스템에 대한 만족도도 높았다. 또한 기본 영어 단어 학습용 게임들이 이미 알고 있는 단어 대한 기억 강화에 적합하지만 우리의 게임은 새로운 단어 암기에도 사용할 수 있다.

• The Journal of Advanced Prosthodontics
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• 제7권5호
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• pp.386-391
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• 2015

PURPOSE. The purpose of this preliminary study was to investigate the effects of adding 4,4'-bis(N,N-diethylamino) benzophenone (DEABP) as a co-initiator to a binary photoinitiating system (camphorquinone-amine) to analyze on the degree of conversion (DC) of a light-cured resin for dental 3D printing. MATERIALS AND METHODS. Cylindrical specimens (N=60, n=30 per group, ${\phi}5mm{\times}1mm$) were fabricated using bisphenol A glycerolate dimethacrylate (BisGMA) both with and without DEABP. The freshly mixed resins were exposed to light in a custom-made closed chamber with nine light-emitting diode lamps (wavelength: 405 nm; power: $840mW/cm^2$) for polymerization at each incidence of light-irradiation at 10, 30, 60, 180, and 300 seconds, while five specimens at a time were evaluated at each given irradiation point. Fourier-transform infrared (FTIR) spectroscopy was used to measure the DC values of the resins. Two-way analysis of variance and the Duncan post hoc test were used to analyze statistically significant differences between the groups and given times (${\alpha}$=.05). RESULTS. In the DEABP-containing resin, the DC values were significantly higher at all points in time (P<.001), and also the initial polymerization velocity was faster than in the DEABP-free resin. CONCLUSION. The addition of DEABP significantly enhanced the DC values and, thus, could potentially become an efficient photoinitiator when combined with a camphorquinone-amine system and may be utilized as a more advanced photopolymerization system for dental 3D printing.

• 경영정보학연구
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• 제14권3호
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• pp.131-141
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• 2012

IT 고도화에 따라 정보 유출 및 침해 사고가 날로 증가하고 있다. 이에 따라 대다수의 기업들은 보안 위한 투자를 확대하고 있지만, 여전히 정보 유출의 취약점에 노출되어 있다. 소규모 IT 서비스 기업은 대기업에 비하여 상대적으로 한정된 자원과 인력으로 기업 활동을 수행하고 있으며, 실제 가치를 창출하는 방법에 따라 SI/SM, DB, IR, IP 업종으로 분류되고 있다. 그러나 현재까지 소규모 IT 서비스 기업을 위한 보안관리에 관한 연구는 소규모라는 기업규모와 IT 서비스라는 비즈니스 특성을 고려한 핵심 정보자산식별에 머물러 있는 상황이다. 따라서 본 연구에서는 소규모 IT 서비스 기업의 보안대책 수립을 위한 보안관리 모델을 설계하였다. 그리고 설계된 보안관리 모델에 대해 비즈니스 특성을 고려한 소규모 IT 서비스 기업을 대상으로 실증분석을 수행하고 분석된 결과를 바탕으로 추진전략을 제시하였다.

• Computers and Concrete
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• 제22권1호
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• pp.123-132
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• 2018

Reinforced concrete (RC) columns which are the main vertical structural members are exposed to several static and dynamic effects such as earthquake and wind. However, impact loading that is sudden impulsive dynamic one is the most effective loading type acting on the RC columns. Impact load is a kind of impulsive dynamic load which is ignored in the design process of RC columns like other structural members. The behavior of reinforced concrete columns under impact loading is an area of research that is still not well understood; however, work in this area continues to be motivated by a broad range of applications. Examples include reinforced concrete structures designed to resist accidental loading scenarios such as falling rock impact; vehicle or ship collisions with buildings, bridges, or offshore facilities; and structures that are used in high-threat or high-hazard applications, such as military fortification structures or nuclear facilities. In this study, free weight falling test setup is developed to investigate the behavior effects on RC columns under impact loading. For this purpose, eight RC column test specimens with 1/3 scale are manufactured. While drop height and mass of the striker are constant, application point of impact loading, stirrup spacing and concrete compression strength are the experimental variables. The time-history of the impact force, the accelerations of two points and the displacement of columns were measured. The crack patterns of RC columns are also observed. In the light of experimental results, low-velocity impact behavior of RC columns were determined and interpreted. Besides, the finite element models of RC columns are generated using ABAQUS software. It is found out that proposed finite element model could be used for evaluation of dynamic responses of RC columns subjected to low-velocity impact load.

• 수산해양교육연구
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• 제28권1호
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• pp.1-13
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• 2016

Physiological response of fish and bivalve was estimated to identify the physiological changes of test species by lowering water temperature due to the abrupt stop of cooling water discharge from power plant. The experiment was conducted by two conditions; fall and winter by decreasing water temperature ($2^{\circ}C$/2 days) from $26^{\circ}C$ to $17^{\circ}C$ for fall scenario and from $15^{\circ}C$ to $9^{\circ}C$ for winter scenario, respectively. Test organisms were parrot fish (Oplegnathus fasciantus) and bivalve (Gomphina melanaegis), and end points were mortality for both species, hematocrit and cortisol for fish, and hemolymph and superoxide dismutase(SOD) for bivalve. 48/96hr mortality test revealed no mortality for fish and 47% mortality for bivalve at 96hr/$26^{\circ}C$ only. Significant increases of hematocrit and cortisol were found at fishes exposed to $26^{\circ}C$ (high temperature) and lower temperature ($9{\sim}13^{\circ}C$), respectively. Hemolymph and SOD for bivalve tended to decrease by lowering water temperature from 15 to $9^{\circ}C$ (winter scenario) and no changes from 26 to $17^{\circ}C$ (fall scenario). Fall scenario (from 15 to $9^{\circ}C$) showed more significant changes of physiological response than winter cases (26 to $17^{\circ}C$).

• Journal of Periodontal and Implant Science
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• 제23권2호
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• pp.203-218
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• 1993

This study was designed to examine the effect of tetracycline application to the planed periodontal surgery of the experimentally induced periodontal disease in dogs. Modified Widman flap surgery was done and aqueous tetracycline (1%) was applied to the root surface for 5min, after which the wound was rinsed with saline, and flaps were coronally repositioned. Root surface ntoches were used as reference points. The animals were sacrificed 1 week, 2 weeks, 4 weeks, and 8 weeks after surgery, and block sections of tooth and surround tissue were processed for conventional light and electron microscopy. The results were as follows : 1. A more coronal position of junctional epithelium was observed in the area treated with tetracycline. 2. In the most of the tetracycline - treated teeth, the new collagen fibrils of connective tissue were oriented vertical/or oblique and parallel to the root surface. The vertical or oblique fibers were inserted into the denuded dentin matrix and contacted with exposed dentin collagen fibrils. 3. In the tetracycline - treated root, new cementum apposition, most of acellular extrinsic fiber cementum, was seen with bundles of oriented collagen fibrils incoporating into the cementum. 4. In the control and tetracyclin - treated teeth, bone resorption was observed at the alveolar crest in the 1 week groups.

• Parasites, Hosts and Diseases
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• 제53권4호
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• pp.385-394
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• 2015

Leishmaniasis is a worldwide uncontrolled parasitic disease due to the lack of effective drug and vaccine. To speed up effective drug development, we need powerful methods to rapidly assess drug effectiveness against the intracellular form of Leishmania in high throughput assays. Reporter gene technology has proven to be an excellent tool for drug screening in vitro. The effects of reporter proteins on parasite infectivity should be identified both in vitro and in vivo. In this research, we initially compared the infectivity rate of recombinant Leishmania major expressing stably enhanced green fluorescent protein (EGFP) alone or EGFP-luciferase (EGFP-LUC) with the wild-type strain. Next, we evaluated the sensitivity of these parasites to amphotericin B (AmB) as a standard drug in 2 parasitic phases, promastigote and amastigote. This comparison was made by MTT and nitric oxide (NO) assay and by quantifying the specific signals derived from reporter genes like EGFP intensity and luciferase activity. To study the amastigote form, both B10R and THP-1 macrophage cell lines were infected in the stationary phase and were exposed to AmB at different time points. Our results clearly revealed that the 3 parasite lines had similar in vitro infectivity rates with comparable parasite-induced levels of NO following interferon-${\gamma}$/lipopolysaccharide induction. Based on our results we proposed the more reporter gene, the faster and more sensitive evaluation of the drug efficiency.

• 한국의류학회지
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• 제34권2호
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• pp.357-370
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• 2010

This study presents the basic resources for the enhancement of the competitiveness of the Korean fashion brands in the Chinese fashion market. They are composed of the differences and common points of clothing styles in Seoul, Beijing, and Shanghai, by analyzing the style comparatively. The research was performed by taking pictures of the Summer 2009 street fashions, from July $1^{st}$ to July $15^{th}$ 1999 (10 am to 5 pm). Among the data about the three cities, 200 photos were selected of women in their twenties and thirties, respectively. The disparity of regional preferences were noted in the fields of easy casual, romantic casual, sports casual, character casual, classic style, and feminine style. There were no specific differences in style among the three cities in the easy casual and classic style. The romantic casual after the easy casual were more prevalent in Seoul, as compared to the two cities in China. The neat style was more prevalent in Seoul. In Beijing the feminine style after the easy casual were preferred. The conservative style was more preferred in Seoul, while the body exposed style was preferred in Beijing and Shanghai. In Shanghai, the character casual was preferred and shows the similarity to the fashion style of Seoul, rather than Beijing. The high exposure of the body in romantic casual and feminine styles was more remarkable in Beijing and Shanghai. The frequency of the character casual that emphasized individuality with a unique style was relatively high in Shanghai. Seoul, Shanghai, and Beijing showed a similarity in the acceptance of fashion trends and preferences in clothing style. However, the fashion coordination in Shanghai and Beijing was different from Seoul.