• Restorative Dentistry and Endodontics
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• 제41권3호
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• pp.189-195
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• 2016

Objectives: A variety of root canal sealers were recently launched to the market. This study evaluated physicochemical properties, biocompatibility, and sealing ability of a newly launched resin-based sealer (Dia-Proseal, Diadent) compared to the existing root canal sealers (AHplus, Dentsply DeTrey and ADseal, Metabiomed). Materials and Methods: The physicochemical properties of the tested sealers including pH, solubility, dimensional change, and radiopacity were evaluated. Biocompatibility was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. For microleakage test, single-rooted teeth were instrumented, and obturated with gutta-percha and one of the sealers (n = 10). After immersion in 1% methylene blue solution for 2 weeks, the specimens were split longitudinally. Then, the maximum length of staining was measured. Statistical analysis was performed by one-way analysis of variance followed by Tukey test (p = 0.05). Results: Dia-Proseal showed the highest pH value among the tested sealers (p < 0.05). ADseal showed higher dimensional change compared to AHplus and Dia-Proseal (p < 0.05). The solubility values of AHplus and Dia-Proseal were similar, whereas ADseal had the lowest solubility value (p < 0.05). The flow values of sealer in increasing order were AHplus, DiaProseal, and ADseal (p < 0.05). The radiopacity of AHplus was higher than those of ADseal and Dia-Proseal (p < 0.05). The cell viability of the tested materials was statistically similar throughout the experimental period. There were no significant differences in microleakage values among the tested samples. Conclusions: The present study indicates that Dia-Proseal has acceptable physicochemical properties, biocompatibility, and sealing ability.

• 화약ㆍ발파
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• 제24권1호
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• pp.49-56
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• 2006

도심지에서 폭약을 사용한 굴착공법은 진동 소음 비산 등으로 인한 안전상의 문제로 사용상 많은 제약이 따르고 있다 이러한 이유로 암파쇄굴착공법 (건교부, 2003)에 주로 쓰이는 FINECKER Plus(미진동파쇄기)의 사용이 점차 늘어나고 있다. 따라서 본 사례연구에서는 도심지 현장에서 진동을 제어하기 위해 FINECKER Plus를 적용하고, 신제품 360g 1본(本)과 기존제품 180g 2본(本)의 비교시험과 함께 무진동공법과 병행하여 시공성을 비교하였다. 신제품 360g의 파쇄효율 및 소음 진동수준에서는 대등한 정도로, 작업시간이 32% 감소하여 시공성 면에서는 뛰어난 결과를 얻었다 또한, FINECKER Plus의 굴착량은 $64.2m^3/$일로 무진동공법에 비해 7.7배 정도의 뛰어난 시공성을 나타내었다

• 성인간호학회지
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• 제14권4호
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• pp.543-553
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• 2002

Purpose: The purpose of the study was to compare symptoms, medical therapies, and nursing interventions with terminal cancer patients during the last four weeks of their lives in a hospice unit and general units. Method: For the descriptive survey study, data were collected by reviewing the medical records of 243 patients who died of terminal cancer at K hospital in Seoul. The data was analyzed by using Chi-square test and t-test. Result: The study findings are summarized as follows: There were higher frequencies in physical symptoms of constipation, itching sensation, pain, sleeping disturbance, soreness and dysuria for those patients in the hospice unit than those patient in general units. All emotional symptoms were recorded significantly higher for those patients in the hospice unit than those in general units. Regarding the major medical interventions, pain management was used more significantly for those patients in the hospice unit, but antibiotic therapy and resuscitation were used more significantly for those patients in general units. Conclusion: The hospice unit provided more comprehensive nursing interventions including psychological, spiritual, and family cares as well as physiological care for terminal cancer patients. The facts showed that those patients who would need hospice care in general units should be referred to the hospice unit at an appropriate time.

• 한국항해항만학회지
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• 제38권6호
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• pp.577-583
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• 2014

A ship-to-ship (STS) lightering operation takes place in order to transfer cargo (e.g. crude oil or petroleum products) between an ocean-going ship and a service ship alongside it. Instrumental measurements to accurately determine the relative speeds and distances during the approach between the vessels would benefit the operational safety and efficiency. A velocity information GPS (VI-GPS) system, which uses the instantaneous velocity measures from carrier-phase Doppler measurement, has been applied in a field observation onboard a service ship (Aframax tanker) approaching a ship-to-be-lightered (VLCC) in open waters. This article proposes to apply VI-GPS as the input sensor to a guidance and decision-support system aiming to provide accurate velocity information to the officer in charge of an STS operation. A method for precise velocity measurement using VI-GPS was described and the measurement results were compared each other with the results of Voyage Data Recorder (VDR) and VI-GPS that showed the concept of a guidance and decision-support system applying VI-GPS with the field test results during STS operations. Also, it turned out that VI-GPS has sufficient accuracy to serve as an input sensor from the field test results.

• Restorative Dentistry and Endodontics
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• 제35권4호
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• pp.246-256
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• 2010

수종의 근관치료용 전기모터들의 반복사용과 시간에 따른 회전속도의 변화를 비교하여 근관치료용 전기모터의 회전 안정성을 평가하고자 하였다. 시간에 따라 변화하는 실제회전속도 및 전압과 전류를 측정하고, Student t-test를 통한 실제회전속도와, 반복측정분석을 통한 상관관계를 비교분석 하였다. 동일 종류의 전기모터들 사이의 모든 측정 결과들은 차이를 보이지 않았다. 모든 전기모터에서 반복사용과 시간의 흐름에 따른 회전속도의 변화는 차이를 보이지 않았다. 이상의 결과로, 본 실험에 사용된 모든 전기모터는 일정한 회전속도를 유지해야 하는 회전 안정성의 조건에 충족됨을 알 수 있으며, 반복사용과 시간에 따른 신뢰성 있는 회전속도와 안정적인 전압 및 전류의 유지가 가능하리라 생각된다.

• 한국치위생학회지
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• 제17권4호
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• pp.577-588
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• 2017

Objectives: This study investigated the perception on the effects of malocclusion on employment, and aimed to provide information to those who are seeking employment. Methods: The study examined 306 subjects aged 19 to 39 in Seoul and Gyeonggi-do during the month of December, 2016. The data obtained were analyzed using frequency analysis, t-test, one-way ANOVA, chi-square test and multiple regression analysis among others. Results: The most important factors in job success were education (35.9%), followed by appearance (23.8%), and major (22.1%). On whether there is a correlation between social life and malocclusion, 49.0% and 51.0% of the subjects answered 'Yes' and 'No', respectively. When the factors influencing the perception of the effects of malocclusion on employment were reviewed, it was found that for female(p<0.01) subjects, the perceived effect of malocclusion on life and on employment (p<.001), and the perceived effect of malocclusion on employment were lower in 20-24 year olds and 25-29 year - olds (p<0.01). Conclusions: Many people believe that malocclusion affects employment and that it is necessary to provide information on orthodontic treatment to those who are preparing for employment and ordinary. However, it is important to provide correct information about orthodontic treatments, including functional improvement, rather than simply focusing too much on aesthetic effects alone.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.305-324
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• 1997

Numerous materials such as amalgam, IRM, SuperEBA, dessicated ZOE, and Ketac-Silver have been used as a root-end filling material or to repair furcation perforations. But so far no material has been found to satisfy all of the requirements of an ideal restorative material. Recently, mineral trioxide aggregate (MTA) has been suggested for use as a root end filling material and for the repair of furcation perforations. The purpose of this study was to compare the effect of MTA on the proliferation of MC3T3/E1 osteoblastic cell, formation of bone nodule, alkaline phosphatase activity, and finally the tissue reaction of bone with those of amalgam, IRM, SuperEBA, dessicated ZOE, and Ketac-Silver. The following conclusions were drawn within the limits of the experimental results : 1. MTA showed a excellent proliferation of osteoblastic cell and Ketac-Silver showed moderate proliferation of osteoblastic cell. The rest of test materials showed no proliferation of osteoblastic cell. 2. Many of definite bone nodules were found in the MTA group. In contrast, Ketac-Silver group showed no definite bone formation but only showed mild sign of bone formation. 3. Alkaline phosphatase activity of Ketac-Silver and MTA showed similar results. But both of them showed higher activity than that of other materials (p<0.005). 4. The tissue reaction to implanted MTA in the calbarium of mouse was milder than that observed with other materials. The tissue reaction of dessicated ZOE showed the worst results among the test materials.

• 한국게임학회 논문지
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• 제18권1호
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• pp.19-26
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• 2018

본 연구는 하드코어 게임유저는 기(旣)경험된 게임 조작처리 훈련으로 사용자 조작에 차이를 가지는 VR게임 플레이 시 조작 딜레이 검증하였다. HCI 기반 실험적 연구접근으로 사용자 조작 주기 가설이 적용된 2D 3D VR 형식 프로토타입 게임을 제작하였다. 이를 바탕으로 총 121명을 대상 2D 3D VR 형식 인터페이스 사용자 조작 실험 실시하였다. 실험으로 추출된 평균 사용자 조작 주기는 비교 검증하기 위하여 독립표본 T검정을 실시하였다. 검정 결과 2D VR 형식에 따른 사용자조작 주기 평균시간의 차이는 검증되었다. 3D VR 형식에 따른 사용자 조작주기 평균시간의 차이는 유의미의 귀무가설이 채택되어 차이가 없다 판명 되었다.

• 융합신호처리학회논문지
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• 제10권4호
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• pp.214-219
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• 2009

본 논문에서는 해금 사운드 콘텐츠의 저작권 보호를 위해 해금의 주파수 특성을 고려한 워터마킹 알고리듬을 제안한다. 해금 음은 1500Hz~2000Hz 대역과 2800Hz~3500Hz 대역에서 배음 성분의 크기가 공통적으로 크게 나타나는데 이 대역을 워터마크 삽입대역으로 결정하였다. 제안한 방법은 원 신호에 푸리에 변환을 하여 주파수 영역으로 변환하고 삽입대역에 속한 배음 성분에 PN 시퀀스를 통해 생성한 워터마크 비트를 삽입하였다. 또한 저역통과 필터, 대역통과 필터, 잘라내기, 노이즈 추가, MP3 압축과 같은 공격에서 최대 1.41%의 BER을 보였고, 클래식, 팝, 가야금 등의 연주곡과 비교 실험 결과 해금에서 가장 뛰어난 성능을 보였다. 주관 청취 테스트인 MUSHRA 테스트 결과 해금 음에 대해서는 평균 98점 이상을 보였고 국악연주곡에서는 96.67점을 보여 모두 Excellent의 평가 결과를 보였다.

• 한국융합학회논문지
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• 제12권10호
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• pp.113-120
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• 2021

본 연구는 치위생(학)과 학생의 전공만족도, 회복탄력성 및 임상실습만족도 정도를 알아보고, 임상실습만족도에 영향을 미치는 요인을 확인하기 위하여 시행되었다. 임상실습 경험이 있는 치위생(학)과 학생을 대상으로 설문조사를 시행하여 총 256부를 최종 분석하였다. 자료분석은 연구 목적에 따라 기술통계, t-test, ANOVA, 다중회귀분석을 실시하였다. 연구결과 임상실습만족도에 영향을 미치는 변인은 전공만족도의 관계만족이 유의한 정적영향을 주는 것으로 나타났다. 이러한 결과를 토대로 임상실습만족도를 향상시키기 위해서는 전공만족도 중 관계만족을 높이는 것이 중요하며, 학생에 대한 교수자의 지지, 라포 형성 등 관계만족을 높이기 위한 다양한 노력이 필요하다.