• 한국철도학회논문집
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• 제10권6호
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• pp.717-722
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• 2007

본 논문에서는 직류 1500V 지하철 변전소의 가선전압과 피더별 전류량을 측정한 결과를 분석한다. 선릉과 양동시장 변전소들의 피더별 소비 및 회생전력을 측정하고, 피더별로 발생된 회생전력이 타 피더로 전달되는 전력량을 계산하였다. 전철변전소에서 회생전력이 교류될 수 있는 거리를 타 변전소와의 중간지점으로 가정하고, 전동차 1편성의 회생전력량을 기초로 변전소에서 발생되는 총 회생전력량을 근사식으로 계산하였다. 이렇게 얻어진 값과 측정된 피더간 교류된 회생전력량을 사용하여 변전소의 회생전력 실효전력량을 계산하고 회생인버터가 설치된 후 재활용할 수 있는 회생전력량을 근사적으로 얻었다.

• 한국식품조리과학회지
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• 제28권1호
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• pp.33-40
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• 2012

The purpose of the study is to examine the importance and performance degrees between Selection Attributes of American beef by IPA(Importance-Performance Analysis) for university students in Seoul and Gyeonggi Area. A total of 590 questionnaires were distributed, and 481 questionnaires were used in the study (81.5% of response rate). According to the IPA results of 12 selection attributes for American beef, the selection attributes with relatively low satisfaction but high importance(II quadrant) were 'country of origin', 'safety', 'cleanliness and hygiene'. The factor to be improved relatively through to the results of IPA was consumer confidence factor ('country of origin', 'safety', 'cleanliness and hygiene') and it was confirmed that university students had a low satisfaction in large degrees compared to the significance of American beef. Therefore, recovery of consumer confidence of American beef is urgent as well as the need to increase satisfaction of consumers. From now on, based on these results, it is considered that many efforts are necessary to increase the trust of consumers by planting awareness that American beef is safe by setting institutional conditions to vitalize purchase of American beef. Moreover, it is considered that these efforts would be significant for the vitalization of restaurants with beef as their main menu, and vitalization of consumption of Korean beef as well as American beef henceforth.

• The Journal of Advanced Prosthodontics
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• 제12권5호
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• pp.299-306
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• 2020

PURPOSE. The aim of this study was to evaluate the accuracy of six recently introduced intraoral scanners (IOSs) for single crown preparations isolated from the complete arch, and to determine the effect of scanning sequence on accuracy. MATERIALS AND METHODS. A complete arch with right and left canine preparations for single crowns was used as a study model. The reference dataset was obtained by scanning the complete arch using a highly accurate industrial scanner (ATOS Core 80, GOM GmbH). Six different IOSs (Trios, iTero, Planmeca Emerald, Cerec Omnicam, Primescan, and Virtuo Vivo) were used to scan the model ten times each. The scans performed with each IOS were divided into two groups, based on whether the scanning sequence started from the right or left quadrant (n=5). The accuracy of digital impression was evaluated using three-dimensional analyzing software (Geomagic Studio 12, 3D Systems). The Kruskal Wallis and Mann- Whitney U statistical tests for trueness analysis and the One-way ANOVA test for precision analysis were performed (α=.05). RESULTS. The trueness and precision values were the lowest with the Primescan (25 and 10 ㎛), followed by Trios (40.5 and 11 ㎛), Omnicam (41.5 ㎛ and 18 ㎛), Virtuo Vivo (52 and 37 ㎛), iTero (70 and 12 ㎛) and Emerald (73.5 and 60 ㎛). Regarding trueness, iTero showed more deviation when scanning started from the right (P=.009). CONCLUSION. The accuracy of digital impressions varied depending on the IOS and scanning sequence used. Primescan had the highest accuracy, while Emerald showed the most deviation in accuracy for single crown preparations.

• International Journal of Oral Biology
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• 제40권2호
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• pp.93-101
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• 2015

The efficacy of air-polishing on subgingival debridement, as compared to scaling and root planning (SRP), was evaluated clinically and microbiologically. Fifteen patients diagnosed as chronic periodontitis, and having single-root tooth over 5 mm of pocket depth symmetrically in the left and right quadrant, were investigated. Subgingival debridement was performed by SRP and air-polishing. The results were evaluated and compared clinically and microbiologically. Probing pocket depth (PPD), bleeding on probing (BOP), relative attachment level (RAL) and change of gingival crevicular fluid (GCF) were assessed before treatment, and at 14 and 60 days after treatment. Microbial analysis was done pre-treatment, post-treatment, and at 14 and 60 days after treatment. Results of air polishing showed that post treatment, the PPD and BOP decreased, and attachment gain was observed. There was no clinical difference when compared to SRP. The volume of GCF decreased at 14 days, and increased again at 60 days. Compared to SRP, there was a statistical significance of the volume of GCF at 60 days in air-polishing. In the microbial analysis, high-risk bacteria that cause periodontal disease were remarkably reduced. They decreased immediately after treatment, but increased again with the passage of time. Thus, our results show that subgingival debridement by air-polishing was effective for decrease of pocket depth, attachment gain, decrease of GCF and inhibition of pathogens. Further studies are required to compare air-polishing and SRP, considering factors such as degree of pocket depth and calculus existence.

• 한국정밀공학회지
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• 제23권8호
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• pp.72-79
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• 2006

We measured grating pitch standards using optical diffractometry and analyzed measurement uncertainty. Grating pitch standards have been used widely as a magnification standard for a scanning electron microscope (SEM) and a scanning probe microscope (SPM). Thus, to establish the meter-traceability in nano-metrology using SPM and SEM, it is important to certify grating pitch standards accurately. The optical diffractometer consists of two laser sources, argon ion laser (488 nm) and He-Cd laser (325 nm), optics to make an incident beam, a precision rotary table and a quadrant photo-diode to detect the position of diffraction beam. The precision rotary table incorporates a calibrated angle encoder, enabling the precise and accurate measurement of diffraction angle. Applying the measured diffraction angle to the grating equation, the mean pitch of grating specimen can be obtained very accurately. The pitch and orthogonality of two-dimensional grating pitch standards were measured, and the measurement uncertainty was analyzed according to the Guide to the Expression of Uncertainty in Measurement. The expanded uncertainties (k = 2) in pitch measurement were less than 0.015 nm and 0.03 nm for the specimen with the nominal pitch of 300 nm and 1000 nm. In the case of orthogonality measurement, the expanded uncertainties were less than $0.006^{\circ}$. In the pitch measurement, the main uncertainty source was the variation of measured pitch values according to the diffraction order. The measurement results show that the optical diffractometry can be used as an effective calibration tool for grating pitch standards.

• 융합정보논문지
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• 제9권2호
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• pp.155-164
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• 2019

이 연구에서는 발달장애인 가족 284명을 대상으로 가족지원 서비스에 대한 중요도와 만족도 인식 수준을 알아보았는데, 그 결과는 다음과 같다. 첫째, 발달장애인 가족의 가족지원 서비스에 대한 중요도-만족도 인식 수준은 전반적으로 그리고 하위유형별로 모두 통계적 유의차가 있는 것으로 나타났다. 둘째, 발달장애인 가족의 가족지원 서비스에 대한 중요도 인식 수준은 양육활동 지원, 신체적 물질적 안녕 지원, 가족 상호작용 지원의 순으로 나타났다. 셋째, 발달장애인 가족의 가족지원 서비스에 대한 만족도는 양육활동 지원, 가족 상호작용 지원, 정서적 안녕 지원의 순으로 나타났다. 넷째, 중요도-만족도 사분면의 특성을 분석하여 현상 유지, 개선 노력, 중장기 전략 필요 등을 제안하였다. 이 연구의 결과는 발달장애인 가족지원 서비스의 개선을 위한 기초자료로 활용할 수 있을 것으로 기대된다.

• 대한치과교정학회지
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• 제51권2호
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• pp.95-104
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• 2021

Objective: To evaluate the trueness and precision of full-arch scans acquired using five intraoral scanners and investigate the factors associated with the dimensional accuracy of the intraoral scan data. Methods: Nine adult participants (mean age, 34.3 ± 8.3 years) were recruited. Four zirconium spheres (Ø 6 mm) were bonded to the canines and the molars. Following acquisition of reference scans using an industrial-grade scanner, five intraoral scanners, namely i500, CS3600, Trios 3, iTero, and CEREC Omnicam, were used to scan the arches. Linear distances between the four reference spheres were automatically calculated, and linear mixed model analysis was performed to compare the trueness and precision of the intraoral scan data among the different scanners. Results: The absolute mean trueness and precision values for all intraoral scanners were 76.6 ± 79.3 and 56.6 ± 52.4 ㎛, respectively. The type of scanner and the measured linear distances had significant effects on the accuracy of the intraoral scan data. With regard to trueness, errors in the intermolar dimension and the distance from the canine to the contralateral molar were greater with Omnicam than with the other scanners. With regard to precision, the error in the linear distance from the canine to the molar in the same quadrant was greater with Omnicam and CS3600 than with the other scanners. Conclusions: The dimensional accuracy of intraoral scan data may differ significantly according to the type of scanner, with the amount of error in terms of trueness being clinically significant.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.281-281
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• 2022

바닥에서 생성되는 난류는 순간적으로 강한 모멘텀을 바닥에 전달함과 동시에 바닥에 있는 입자를 움직이게 한다. 경계층 내 난류 운동에 대한 분석은 다양한 유사 이송 문제를 이해하기 위해 필수적이며 이에 따라 많은 선행 연구들은 실험실 실험을 통해 해당 연구를 수행하였다. 본 연구에서는 선행 연구에서 사용하지 못했던 진보된 실험 방법을 활용하여 바닥 경계층 내의 난류 운동에 대해 확인하고 해당 운동에 의해 관성 입자의 움직임이 어떻게 발생하는지에 대하여 물리적으로 설명하고자 한다. 다양한 흐름 조건에서 3가지의 입경 크기를 가지는 모래 입자를 가지고 실험을 수행하였으며, 실험 조건별 고해상도 유속장 및 관성 입자의 움직임은 3차원 입자 영상 유속계 (Particle Image Velocimetry; 이하 PIV)와 입자 추적 유속계 (Particle Tracking Velocimetry; 이하 PTV)를 동시에 적용하여 파악하였다. 취득된 3차원 유속장과 입자 궤적을 기반으로 실험 조건별 흐름 및 입자 거동 특성에 대해 분석하였으며, 관성 입자의 움직임을 발생시키는 3차원 난류 운동은 측정된 유속장에서 산정한 Q-criterion 값을 기반으로 도식화하였다. 측정값 내에는 난류 운동에 대한 정보와 더불어 잡음이 포함되어 있으므로 이를 제거하고자 적합 직교 분해 (Proper Orthogonal Decomposition; 이하 POD) 방법을 적용하였다. 그리고 POD로 추출한 유속장을 통해 바닥면 부근에 존재하는 헤어핀 와류 운동 혹은 와류 묶음과 같은 난류 고유 구조를 파악하였다. 해당 와류 운동들의 3차원 난류 특성을 확인하고자 비등방성 불변 지도(anisotropy invariant map)를 활용하였으며 경계층 내부에서 난류의 형태가 흐름 방향으로 늘어진 럭비공 형태임을 확인하였다. 마지막으로, 입자의 움직임을 발생시키는 난류 이벤트를 결정하고자 사방구 분석 (Quadrant analysis) 기법을 적용하였으며 흐름 조건별로 입자를 움직이게 하는 난류 이벤트는 달라짐을 확인하였다.

• 한국간호교육학회지
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• 제30권2호
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• pp.170-181
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• 2024

Purpose: This study aims to assess the importance and performance of patient safety activities for inpatients in small- and medium-sized hospitals. The objective is to identify the need for patient safety education by analyzing differences in importance and performance ratings. Methods: The study involved 300 patients hospitalized in three small- and medium-sized hospitals. Data collection took place in October 2023, focusing on investigating the importance and performance of patient safety activities. Descriptive statistics and an Importance-Performance Analysis (IPA) were conducted using the IBM SPSS statistics 25.0 program. Results: The average importance of patient safety activities was 3.51±0.41, and the average performance was 3.37±0.43, indicating that the importance of patient safety activities was higher than their performance. According to the IPA, the components of patient safety activities that fell into the second quadrant of high importance but low performance included three medication-related items and one test/procedure/surgery-related item. Conclusion: In this study, it was found that inpatients in small- and medium-sized hospitals had a higher importance on patient safety activities than performance and needed ways to increase their performance. Therefore, it is necessary to develop a customized educational program that can increase the practical performance of inpatients' patient safety activities based on the contents that were determined to need improvement.

• 해양환경안전학회지
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• 제29권6호
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• pp.587-597
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• 2023

조류의 이상증식을 일으키는 새만금호 부영양화를 평가하기 위해 Carlson 지수를 적용하였다. 연구를 위해 2021년 월별로 새만금호내 총 7개 정점에서 수질조사를 실시하였다. Chl.a의 농도는 동계에는 만경수계가 약간 높았고, 춘계와 하계에는 동진수계가 약간 높게 나타났으나, 일부 시기를 제외하고는 전체적으로 호소 수질환경기준 3등급과 비슷하거나 낮은 농도를 나타내었다. COD는 만경수계와 동진수계 모두 하계와 추계에 호소 수질환경기준 4등급과 유사하거나 상회하는 수질을 나타내었다. TOC는 모든 지점에서 3등급 이내의 수질을 보였다. 총인 농도는 호수 수질환경기준 4등급을 초과하였고, 월별로는 1월과 강우 후 8월에 높게 나타났다. 수질인자간의 상관성 분석에서 염분 농도에 대한 유기물, 총인, 총질소의 상관성이 상대적으로 높게 나타나 배수갑문을 통한 해수유입과 상류 하천을 통한 담수 유입에 의한 담수역, 기수역, 해수역의 수질 특징을 반영하고 있었다. 영양상태지수에 의한 새만금호의 부영양화 변동 특성을 보면, Chl.a와 SD, TN의 지수에서 부영양화 초기 단계의 수질을 보였으며, TP 지수의 경우 심각한 부영양화 상태를 나타내고 있었다. 수질인자간 부영양화 지수의 크기는 모든 수계에서 TSI(TP) > TSI(TN) > TSI(SD) > TSI(CHL)의 순으로 나타났다. TSI(CHL)에 대한 TSI(TP) 및 TSI(SD)와의 편차를 2차원 평면으로 나타낸 사분면 분석 결과를 보면, 조류 성장에 대한 총인이 영향에서는 모든 수계에서 대부분의 총인(TP)에 의한 제한적 영향은 나타나지 않았으며, 빛 감쇠에 영향을 미치는 인자는 외부로부터 유입되는 적은 입자상 물질에 의한 영향이 크게 나타나는 것으로 평가할 수 있다.