• 대한치과보철학회지
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• 제46권6호
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• pp.561-568
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• 2008

STATEMENT OF PROBLEM: Currently, many implant systems are developed and divided into two types according to their joint connection: external or internal connection. Regardless of the connection type, screw loosening is the biggest problem in implant-supported restoration. PURPOSE: The purpose of this study is to assess the difference in stability of abutment screws between the external and internal hexagonal connection types under cyclic loading. MATERIAL AND METHODS: Each of the 15 samples of external implants and internal abutments were tightened to 30 N/cm with a digital torque gauge, and cemented with a hemispherical metal cap. Each unit was then mounted in a $30^{\circ}$ inclined jig. Then each group was divided into 2 sub-groups based on different periods of cyclic loading with the loading machine (30 N/ cm - 300 N/cm,14 Hz: first group $1{\times}10^6$, $5{\times}10^6$ cyclic loading; second group $3{\times}10^6$, $3{\times}10^6$ for a total cyclic loading of $6{\times}10^6$) The removal torque value of the screw before and after cyclic loading was checked. SPSS statistical software for Windows was used for statistical analysis. Group means were calculated and compared by ANOVA, independent t-test, and paired t-test with ${\alpha}$=0.05. RESULTS: In the external hexagonal connection, the difference between the removal torque value of the abutment screw before loading, the value after $1{\tims}10^6$ cyclic loading, and the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was not significant. The difference between the removal torque value after $3{\times}10^6$ cyclic loading and after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. In the internal hexagonal connection, the difference between the removal torque value before loading and the value after $1{\times}10^6$ cyclic loading was not significant, but the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was reduced and the difference was significant (P < .05). In addition, in the internal hexagonal connection, the difference between the removal torque value after $3{\times}10^6$ cyclic loading and the value after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. CONCLUSION: The external hexagonal connection was more stable than the internal hexagonal connection after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading (t = 10.834, P < .001). There was no significant difference between the two systems after $3{\times}10^6$, and additional $3{\times}10^6$ cycles.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권4호
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• pp.229-238
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• 2017

Objectives: The primary purpose of this study was to investigate the factors related with additional administration of sedative agent during intravenous conscious sedation (IVS) using midazolam (MDZ). The secondary purpose was to analyze the factors affecting patient satisfaction. Materials and Methods: Clinical data for 124 patients who had undergone surgical extraction of mandibular third molar under IVS using MDZ were retrospectively investigated in this case-control study. The initial dose of MDZ was determined by body mass index (BMI) and weight. In the case of insufficient sedation at the beginning of surgery, additional doses were injected. During surgery, peripheral oxygen saturation, bispectral index score (BIS), heart rate, and blood pressure were monitored and recorded. The predictor variables were sex, age, BMI, sleeping time ratio, dental anxiety, Pederson scale, and initial dose of MDZ. The outcome variables were additional administration of MDZ, observer's assessment of alertness/sedation, intraoperative amnesia, and patient satisfaction. Descriptive statistics were computed, and the P-value was set at 0.05. Results: Most patients had an adequate level of sedation with only the initial dose of MDZ and were satisfied with the treatment under sedation; however, 19 patients needed additional administration, and 13 patients were unsatisfied. In multivariable logistic analysis, lower age (odds ratio [OR], 0.825; P=0.005) and higher dental anxiety (OR, 5.744; P=0.003) were related to additional administration; lower intraoperative amnesia (OR, 0.228; P=0.002) and higher BIS right before MDZ administration (OR, 1.379; P=0.029) had relevance to patient dissatisfaction. Conclusion: The preoperative consideration of age and dental anxiety is necessary for appropriate dose determination of MDZ in the minor oral surgery under IVS. The amnesia about the procedure affects patient satisfaction positively.

• 대한전자공학회논문지SP
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• 제49권4호
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• pp.40-48
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• 2012

본 논문은 추가적인 화이트 채널을 사용한 프로젝터와 사용하지 않은 프로젝터간의 매칭 실험을 통하여 색상이동 현상을 모델링하였고, 색상을 수정하는 방법을 제안하였다. 전체 색상 값에 대해 색상이동현상을 정량화하기 위하여, 동일한 밝기와 채도 값을 유지하여 24개의 색상 패치 값을 생성하여 이를 화이트를 추가한 상태와 추가하지 않은 상태에서 투영하였다. 다음으로 각각의 패치에 대해 화이트를 추가 하지 않은 상태와 동일한 색상으로 인지되도록 화이트를 추가한 상태의 색상 값을 변경하였다. 색상 매칭 실험을 통하여 얻은 색상 이동 값을 6개의 구간으로 나누어 4차 방정식을 이용하여 수식화하여 임의의 색상 값에 대한 색상 이동 값을 추정하였고, 색상 값을 수정하는 위하여 사용하였다. 실제로, 입력 RGB 영상은 각각의 픽셀에 대해 CIELAB LCH 색 공간으로 변경하여 각각의 픽셀의 색상 값을 계산하였다. 이 색상 값은 추정된 색상이동량을 이용하여 수정하게 된다. 최종적으로 결과 RGB 영상은 역 과정으로 변환하였다. 제안한 방법을 평가하기 위하여 여러 가지 테스트 영상을 이용하여 매칭 실험을 수행하였고 이를 z-scores를 이용하여 비교하였다.

• 한국세라믹학회지
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• 제31권6호
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• pp.685-693
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• 1994

Sublimation vapour pressures and sublimation enthalpy of anhydrous bismuth trifluoride have been measured by the continuous gravimetric Cnudsen-effusion method from 639-7 to 782.8 K. Additional effusion measurements have also been made from 750.6 to 863.1 K by the torsion-effusion method. Based on a correlation of subHo298.15 and subSo298.15, a recommended P(T) equation has been obtained for BiF3(s); logP= -C/T+5.2375logT-3.205$\times$10-3+4.661$\times$104/T2+1.348 where P is in Pa, T in Kelvin, subHo298.15 in kJ mol-1 and C=( subHo298.15-13.5149)/1.9146$\times$10-2. Condensation coefficients and their temperature dependence have been derived from the effusion measurements.

• International Journal of Internet, Broadcasting and Communication
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• 제7권1호
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• pp.1-5
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• 2015

In this study, we consider the transportation problem in port container terminals. It aims to determine positions in yards to place the containers at the adequate times. The containers on ship must be unloaded one by one from top to bottom, and placed in the main yard in order to reduce additional cost required for unnecessary unloading when getting out by customer with given timetable. The cost for transportation at container terminals could be reduced by a new approach in scheduling: move the containers from ship and stack them onto main yard that minimizes cost of yard crane operation when unloading for customer.

• The Journal of Asian Finance, Economics and Business
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• 제8권7호
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• pp.91-101
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• 2021

The paper examines the impact of the COVID-19 pandemic on the stock market prices. The vector autoregression model (VAR) has been used in this analysis to survey 341 stocks on the Ho Chi Minh City Stock Exchange (HOSE) for the period from January 23, 2020 to December 31, 2020. The empirical results obtained from the analysis of 11 economic sectors suggest that there is a statistically significant impact relationship between COVID-19 and the healthcare and utility industries. Additional findings show a statistically significant negative impact of COVID-19 on the utility share price at lag 1. Analysis of impulse response function (IRF) and forecast error variance decomposition (FEVD) show an inverse reaction of utility stock prices to the impact of COVID-19 and a gradual disappearing shock after two steps. Major findings show that there is a clear negative effect of the COVID-19 pandemic on share prices, and the daily increase in the number of confirmed cases, indicate that, in future disease outbreaks, early containment measures and positive responses are necessary conditions for governments and nations to protect stock markets from excessive depreciation. Utility stocks are among the most severely impacted shares on financial exchanges during a pandemic due to the high risk of immediate or irreversible closure of manufacturing lines and poor demand for basic amenities.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2546-2550
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• 2003

We propose a new method of robot manipulator modeling. Different from existing modelers, our modeler provides a convenient robot modeling configured from modules from module library or module modeling. In addition, a way of using D-H parameters to configure a robot is proposed. These additional functions of robot modeling can be a powerful and flexible tool for various needs of robot modeling. We show an example of modeling with our approach.

• 한국응용곤충학회:학술대회논문집
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• 한국응용곤충학회 2001년도 추계 합동 심포지엄 및 학술발표대회
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• pp.121-121
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• 2001

• 펄프종이기술
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• 제31권5호
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• pp.95-100
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• 1999

In order to find fungi having high treatment activity of kraft pulp bleaching (E1) effluent without any additional nutrietns, 124 strains of white-rot fungi were isolated from decayed wood samples. The author isolated five fungi(KS-62, MZ-400 , YK-719, YK-472 and Phanerochaete sordida YK-624) having high-decolorization activity of the E1 effluent. Particularly, the fugus KS-62 show the high effect of the decolorization and the degradation of the chlorinated lignin in the E1 , effluent compared with Coriolus versicolor and Phanerochaete chrysosporium.

• 대한수학회보
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• 제39권2호
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• pp.283-287
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• 2002

In this paper, we will investigate the set of linear operators on real square matrices that strongly preserve multivariate majorisation without any additional conditions on the operator. This answers earlier conjecture on nonnegative matrices in [3] .