• 전자공학회논문지SC
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• 제38권4호
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• pp.45-53
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• 2001

본 논문에서는 HDTV급 이상의 고해상도 AC PDP를 구동할 수 있는 새로운 구동방식을 제안하였다. 제안한 구동방식은 유지방전 펄스의 상승부와 하강부를 어드레스 방전에 이용하여 0.85${\mu}s$의 데이터 펄스 및 스캔 펄스 쪽으로 어드레스 방전이 가능하고 위상차이가 있는 유지방전 펄스를 인가하여 어드레스 방전의 횟수를 증가시켜 고해상도의 AC PDP패널을 고휘도로 구동할 수 있다. 유지 방전 주파수가 125kHz이고 4개의 위상차이를 줄 경우 최대 2080 수평해상도의 패널을 구동 할 수 있다. 이를 확인하기 위해 $30{\times}58$ 해상도의 4인치 칼라 AC PDP를 제한한 구동방식으로 구동하였으며 전압이 140V이고 주파수가 125kHz인 유지방전 펄스로 화면 잡음 없이 850 $cd/m^2$의 고휘도를 구현하였다.

• 한국항공우주학회지
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• 제34권6호
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• pp.83-91
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• 2006

현대의 고성능 전투기는 공력성능 및 조종성능의 향상을 위하여 대부분 세로축 방향으로 항공기를 불안정하게 설계하는 정안정성 완화 개념을 채택하고 있다. 비행제어법칙의 설계 작업은 불안정하게 설계된 항공기에 안정성을 부여하고, 주어진 비행임무에 대하여 만족스런 조종성능을 발휘할 수 있도록 비행성능을 조작하는 일련의 과정이다. 세로축 무게중심은 무장형상, 연료상태 및 착륙장치의 위치에 영향을 받으며 항공기 안정성에 많은 영향을 미친다. 따라서 무게중심의 이동은 세로축 안정도 여유에 영향을 미친다. 본 논문에서는 운용 시에 발생 가능한 최대 후방 무게중심에 대해 항공기 안정성을 해석하였고, 비행시험을 통해 최종적으로 검증하였다. 선형해석 항목은 세로축 단주기 모드 특성 및 안정도 여유에 관하여 행하였으며, 비선형 해석 항목은 단주기 모드를 해석하기 위해 세로축 가진 입력에 대한 항공기 응답특성을 분석하였다. 또한, 최대 후방 무게중심에서 수행된 고받음각 비행시험 자료를 제시함으로써 T-50 고등훈련기의 비행 안정성을 제시하였다.

• 한국산업보건학회지
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• 제27권3호
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• pp.221-230
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• 2017

Objectives: This study was conducted to investigate general characteristics, job characteristics, characteristics of hospitals, and hospital coordinators, and to investigate the factors affecting the job satisfaction of medical workers. Methods: The data was collected through a self-reported questionnaire among 435 workers in plastic surgery and dermatology clinics in metropolitan city G. We investigated general characteristics, job-related characteristics, characteristics of medical institutions and hospital coordinators, job performance of hospital coordinators, and job satisfaction of medical workers. T-tests, ANOVA, correlation, and multiple regression analyses were conducted to investigate the factors related with job satisfaction. Results: The job satisfaction of the medical workers and the perceived job performance of hospital coordinators were $3.55{\pm}0.40$ and $3.74{\pm}0.43$, respectively. In multiple regression analysis, drinking frequency, number of night shifts, number of work days, and hospital coordinator introduction years were associated with the job satisfaction of medical workers. The more the overall job performance of hospital coordinators increased, the higher was job satisfaction(B=0.458, p<0.001). In detail, the more job roles(B=0.218, p<0.001), core competency(B=0.145, p=0.005), and leadership(B=0.099, p=0.037) increased, the higher was the job satisfaction of medical workers. Conclusions: The job satisfaction of the medical institution workers was associated with the perceived job performance of the hospital coordinator. In order to increase the job satisfaction of medical institution workers, a hospital coordinator with specialized job performance will be able to improve job satisfaction by carrying out efficient work in the medical institution.

• Smart Structures and Systems
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• 제17권1호
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• pp.91-105
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• 2016

One of the most commonly used techniques to strengthen steel reinforced concrete structures is the application of externally bonded patches in the form of carbon fiber reinforced polymers (CFRP) or recently, textile reinforced cements (TRC). These external patches undertake the tensile stress of bending constraining concrete cracking. Development of full-field inspection methodologies for fracture monitoring are important since the reinforcing layers are not transparent, hindering visual observation of the material condition underneath. In the present study acoustic emission (AE) and digital image correlation (DIC) are applied during four-point bending tests of large beams to follow the damage accumulation. AE helps to determine the onset of fracture as well as the different damage mechanisms through the registered shifts in AE rate, location of active sources and change in waveform parameters. The effect of wave propagation distance, which in large components and in-situ can well mask the original information as emitted by the fracture incidents is also discussed. Simultaneously, crucial information is supplied by DIC concerning the moments of stress release of the patches due to debonding, benchmarking the trends monitored by AE. From the point of view of mechanics, conclusions on the reinforcing contribution of the different repair methodologies are also drawn.

• Safety and Health at Work
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• 제7권1호
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• pp.72-77
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• 2016

Background: This study aimed to determine the prevalence and factors related to needle stick injuries (NSIs) and to assess related safety measures among a sample of Iranian nurses. Methods: In this cross-sectional study, a random sample of 168 registered active nurses was selected from different wards of one of the hospitals of Shiraz University of Medical Sciences (SUMS). Data were collected by an anonymous questionnaire and a checklist based observational method among the 168 registered active nurses. Results: The prevalence of NSIs in the total of work experience and the last year was 76% and 54%, respectively. Hollow-bore needles were the most common devices involved in the injuries (85.5%). The majority of NSIs occurred in the morning shift (57.8%) and the most common activity leading to NSIs was recapping needles (41.4%). The rate of underreporting NSIs was 60.2% and the major reasons for not reporting the NSIs were heavy clinical schedule (46.7%) and perception of low risk of infection (37.7%). A statistically significant relationship was found between the occurrence of NSIs and sex, hours worked/week, and frequency of shifts/month. Conclusion: The study showed a high prevalence of NSIs among nurses. Supportive measures such as improving injection practices, modification of working schedule, planning training programs targeted at using personal protective equipment, and providing an adequate number of safety facilities such as puncture resistant disposal containers and engineered safe devices are essential for the effective prevention of NSI incidents among the studied nurses.

• 한국정보통신학회논문지
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• 제12권7호
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• pp.1173-1179
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• 2008

비교적 낮은 고도에서의 기상위험 탐지를 위한 지상 및 항공기용 기상 레이다의 경우 강력한 지표면 반사파가 존재하게 되며 이러한 강력한 클러터의 제거 없이는 미약한 도플러 신호로부터 신뢰성 있는 기상자료의 추출이 불가능하다. 그러나 이동 클러터 뿐만 아니라 고정 클러터의 경우에도 안테나 회전 및 운영환경에 따른 도플러 변이가 일어나게 되며 이러한 클러터들을 도플러 주파수 영역에서 제거하기는 매우 어려운 문제이다. 따라서 본 논문에서는 도플러 기상 레이다 시스템에 간단한 구조를 갖는 배열 안테나를 활용하여 클러터 들을 공간상에서 효율적으로 제거할 수 있음을 보였다. 적응적으로 동작하는 배열 안테나 시스템의 성능을 검증하기 위하여 다양한 이동 및 고정 클러터, 기상신호들을 모델링 하고 이러한 모의 데이터들을 이용하여 기상 레이다에서의 펄스페어 추정치의 정확성 정도를 비교, 분석하였다.

• 한국음향학회지
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• 제40권2호
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• pp.161-168
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• 2021

본 논문에서는 발성하고 있는 입 주변에 40 kHz의 주파수를 갖는 초음파 신호를 방사하고 되돌아오는 신호의 도플러 변이를 검출하여 발성음을 합성하는 무 음성 대화기술을 제안하였다. 무음성 대화 기술에서는 비 음성 신호로 부터 추출된 특징변수와 해당 음성 신호의 파라메터 간 대응 규칙을 생성하고 이를 이용하여 음성신호를 합성하게 된다. 기존의 무 음성 대화기술에서는 추정된 음성 파라메터와 실제 음성 파라메터간의 오차가 최소화되도록 대응규칙을 생성한다. 본 연구에서는 추정 음성 파라메터가 실제 음성 파라메터의 분포와 유사하도록 생성적 적대 신경망을 도입하여 대응 규칙을 생성하도록 하였다. 60개 한국어 음성을 대상으로 한 실험에서 제안된 기법은 객관적, 주관적 지표상 으로 기존의 신경망 기반 기법보다 우수한 성능을 나타내었다.

• International Journal of Computer Science & Network Security
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• 제23권7호
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• pp.1-8
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• 2023

An Orthogonal Frequency Division Multiplexing (OFDM) based wireless communication system has drawn wide attention for its high transmission rate and high spectrum efficiency in not only radio but also Underwater Acoustic (UWA) applications. Because of the narrow sub-carrier spacing of OFDM, orthogonality between sub-carriers is easily affected by Doppler effect caused by the movement of transmitter or receiver. Previously, Doppler compensation signal processing algorithm for Desired propagation path was proposed. However, other Doppler shifts caused by delayed Undesired signal arriving from different directions cannot be perfectly compensated. Then Receiver Bit Error Rate (BER) is degraded by Inter-Carrier-Interference (ICI) caused in the case of Multi-path Doppler channel. To mitigate the ICI effect, a modified Delay and Doppler Profiler (mDDP), which estimates not only attenuation, relative delay and Doppler shift but also sampling clock shift of each multi-path component, is proposed. Based on the outputs of mDDP, an ICI canceling multi-tap equalizer is also proposed. Computer simulated performances of one-tap equalizer with the conventional Time domain linear interpolated Channel Transfer Function (CTF) estimator, multi-tap equalizer based on mDDP are compared. According to the simulation results, BER improvement has been observed. Especially, in the condition of 16QAM modulation, transmitting vessel speed of 6m/s, two-path multipath channel with direct path and ocean surface reflection path; more than one order of magnitude BER reduction has been observed at CNR=30dB.

• 한국건축시공학회지
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• 제23권6호
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• pp.797-807
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• 2023

본 연구의 목적은 기후변화로 인한 태풍 변화에 대해 알아보고, 이로 인한 주거시설의 피해위험을 정량화하는 것이다. 전 세계적으로 지구온난화로 인한 기후이상과 악기상이 급증하고 있으며, 이로 인한 피해가 급증하고 있다. 특히, 많은 국가에서는 태풍의 패턴 변화로 인해 극심한 피해를 경험하고 있다. 그러나 기후변화에 따른 태풍의 변화와 변화한 위험으로 인한 건물 피해에 대한 실증적 정량화 연구는 부족하다. 따라서, 본 연구에서는 태풍의 변화를 알아보기 위해 우리나라에 영향을 미친 태풍의 빈도와 강도를 분석해 보고, 주거시설의 한국형 태풍 취약도 함수를 활용하여 태풍의 위험변화를 정량화하였다. 본 연구를 통해 민간에서는 기후변화로 인한 태풍 위험의 증가에 따른 다양한 태풍 피해 시나리오 도출 및 비즈니스 모델 도출이 가능하며, 정부에서는 다양한 태풍 대비 위험 관리 전략을 수립할 수 있을 것이다.

• 간호행정학회지
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• 제12권1호
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• pp.63-75
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• 2006

Purpose: This study was aimed to specify roles of nurses from the anesthesia and recovery room by analyzing nursing activities as well as anesthesia nursing during surgery. Method: The objects were 12 RNs working in the recovery room of a university hospital located in Incheon. Self-report was performed by measuring stop-watch for five days from May 17th to May 21st in 2004. Research method was designed to record the time and frequency of the nursing activity from anesthesia and recovery room based on nurses' statement and other references for five days. The data were analyzed with descriptive statistics, ANOVA, and t-test via SPSS Win 10.0 program. Result: Nursing activities in anesthesia recovery room were classified into two different characteristics such as direct and indirect nursing activity. The activities consisted of 11 direct nursing areas and 39 nursing activities in anesthesia preparation room. The indirect nursing was classified into 8 nursing areas and 32 nursing activities. The direct nursing was classified into 12 nursing areas and 55 nursing activity. Also, the indirect nursing was classified into 7 nursing areas and 21 nursing activities in recovery room. In terms of prevalence of nursing activities in the anesthesia preparation room, observation and cooperation of anesthesia was the most prevalent activity, drug and eqipment management the second prevalent, and drug administration the third. On the other hand, in the recovery room, the most prevalent activity was vital sign checking and observation, the second most prevalent activity informative activity, and the third body temperature control. Nursing activity time was recorded according to the nursing characteristics. In the anesthesia preparation room, the direct nursing spent for 8092.20 minutes was larger than the indirect nursing spent for 7198.50 minutes. Also, in the recovery room, the direct nursing spent for 2361.16 minutes was larger than the indirect nursing spent for 1134.13 minutes. 4. Nursing activity time was compared to duty shifts. In the anesthesia preparation room, the direct nursing was more prevalent on day shift and the indirect nursing was prevalent on evening shift. However, in the recovery room, both direct and indirect nursing activities were prevalent on day shift. Conclusion: The role of anesthesia and recovery room nurses was analysed according to the time, frequency, and its characteristics.