• 한국산학기술학회논문지
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• 제10권11호
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• pp.3104-3109
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• 2009

정보수집용 ELINT 장비에서 전파의 방위를 정확하게 찾는 기술은 매우 중요하다. 신호도착 시간차(TDOA)를 이용하는 방위탐지 장치는 수신용 배열 안테나와 시간차 측정장치로 구성된다. TDOA 기술은 에미터 신호가 수신용 배열 안테나 시스템의 각각의 안테나에 도달하는 시간차를 계산하여 에미터의 방위를 산출하는 방법이다. TDOA 방식은 광대역 주파수에서 사용 가능하며 위상변별기나 주파수 측정기와 같은 복잡한 장치가 필요하지 않기 때문에 구성이 간단하다. 그러나 방위 탐지정확도를 높이기 위해서는 시간 측정 분해능이 좋아야하고 수신 안테나 배열간격이 길어야 한다. 본 논문에서는 실제 환경과 유사한 잡음을 고려한 환경에서 방위탐지 정확도를 모사하고 그 결과를 분석하였다.

• 산업융합연구
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• 제7권1호
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• pp.45-61
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• 2009

This research is aimed at grouping for the extent to which the workers' job satisfaction influences productivity with a view to improving theirs, shedding light on the difference between the workers' concepts of job satisfaction and those of the executives of the matter in terms of the statistic characteristics of individuals and coming up with efficient measures to put the Korean tax accounting offices into smooth operation. The paper is suggesting a total of eight hypotheses, and the researcher tested those with the help of difference analyses and a regression analysis. The findings reveal that there was a difference in productivity in accordance with academic background, positions and total number years of work, etc. but tat there was no difference in gender. And superiors and pay among the factors of job satisfaction influenced productivity, whereas promotion and coworkers didn't. The worker subjects and the executive subjects turned out to differ in terms of pay levels, the welfare of the works, and the level of their ability to carry out their business in regard to the actual situation of tax accounting offices in Korea.

• 산업경영시스템학회지
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• 제35권4호
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• pp.227-234
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• 2012

In this study, the masking effect of olfactory stimulus on the awakening state due to sound stimuli while driving using Graphic Driving Simulator was observed through the response of autonomic nervous system. The test was conducted for 11 males in their twenties. The siren of ambulance car was presented to them as auditory stimulus for 30 secs while driving in a situation of high way in the condition of both peppermint and control, respectively, and LF/HF ratio of HRV (Heart Rate Variability), the activity index of sympathetic nerve, and GSR (Galvanic Skin Response) response were examined. The test was proceeded in the order of three stages, that is, sound stimuli (test 1), driving performance, and sound stimuli (test 2), and fragrance stimulus, driving performance, and sound stimuli (test 3), and the physiological signal of GSR, HRV was measured in the whole stages. As a result of test, comparing the results of before and after auditory stimulus test (1) (p < 0.01), test (2) (p < 0.05), and test (3) (p < 0.01), driving performance test (2) (p < 0.01), test (3) (p < 0.01), and olfactory stimulus test (3) (p < 0.05), respectively, GSR response increased, showing significant difference in all the tests. It indicates that when auditory stimulus was presented to the subjects, they were in the awakening state as sympathetic nervous system got activated. As a result of comparing auditory stimulus while driving before and after presenting olfactory stimulus, there was no significant difference in GSR response. The LF/HF ratio of HRV increased, showing a significant difference only in test (2) (p < 0.05), and in driving performance test (2) (p < 0.05) in auditory stimulus, however, it showed no significant difference in olfactory stimulus. As a result of comparing auditory stimulus while driving before and after presenting olfactory stimulus, there was a decrease, showing significant difference (p < 0.05) in LF/HF ratio of HRV. That is, it means that the activation of sympathetic nervous system decreased, and that parasympathetic nervous system got activated. From these results, it was observed that while driving, the awakening level due to auditory stimulus was settled with olfactory stimulus. In conclusion, it was drawn that while driving, olfactory stimulus could have the masking effect on auditory stimulus.

• 대한산업공학회지
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• 제38권2호
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• pp.133-143
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• 2012

The study on social robots has been actively conducted in the robot research community. In the area of robot design, however, there are few studies regarding robot motions that are one of the methods for interaction between humans and robots. This is a preliminary study to find preferred human motions that can be applied to social robots. We conducted a two-phased empirical study about preferred human motions. In the first phase, four representative human motions, such as 'greeting', 'I don't know', 'positive answer', and 'giving', were captured through 28 body makers and video recording. 10 young and 6 elderly Singaporeans participated in the motion capture process. In the second phase, the communication efficiency, emotion, and satisfaction of the human motions recorded in the first phase were measured by a questionnaire and 31 young Koreans, 35 young Singaporeans participated to investigate cultural differences. We drew the conclusion that motions used in the same culture are efficient in communication and also give friendliness and satisfaction. In addition, regardless of user's culture, young people's motions and female motions were preferred in terms of communication efficiency, emotional aspect, satisfaction.

• Advances in aircraft and spacecraft science
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• 제4권6호
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• pp.613-637
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• 2017

The development systems for the Structural Health Monitoring has attracted considerable interest from several engineering fields during the last decades and more specifically in the aerospace one. In fact, the introduction of those systems could allow the transition of the maintenance strategy from a scheduled basis to a condition-based approach providing cost benefits for the companies. The research presented in this paper consists of a definition and next comparison of four methods applied to numerical measurements for the extraction of damage features. The first method is based on the determination of the Structural Intensity field at the on-resonance condition in order to acquire information about the dissipation of vibrational energy throughout the structure. The Damage Quantification Indicator and the Average Integrated Global Amplitude Criterion methods need the evaluation of the Frequency Response Function for a healthy plate and a damaged one. The main difference between these two parameters is their mathematical definition and therefore the accuracy of the scalar values provided as output. The fourth and last method is based on the Mode-shape Curvature, a FRF-based technique which requires the application of particular finite-difference schemes for the derivation of the curvature of the plate. All the methods have been assessed for several damage conditions (the shape, the extension and the intensity of the damage) on two test plates: an isotropic (steel) plate and a 4-plies composite plate.

• 산업공학
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• 제13권2호
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• pp.253-257
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• 2000

This study was conducted to test the significance of differences in the tactual difference thresholds and perception time for tactual direction type and finger type and radius size based on small circular button. The results show that difference threshold of vertical tactual perception is significantly greater than horizontal perception, but there are no significant differences in difference thresholds among finger types and radius sizes. Also, there are no significant differences in tactual perception time among tactual direction types, finger types, and radius types. These findings are applicable for tactual user interface design.

• The Korean Journal of Ecology
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• 제15권3호
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• pp.231-246
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• 1992

In order to estimate effects of air pollution for pinus thunbergii forests arounding onsan industrial complex, structure of forest vegrtation was surveyed. In the survey of forest vegetation, pinus densiflora have been died or being withered, and importance value(I.V) of rhododendron mucromulatum and lespedeza spp. were low at the vicinity of industrial complex. Especially lespedeza maximowiczii and l. maritima were not entirely appeared at the vicinity of industrial complex. I.V. of quercus serrata, robinia pseudoacacia and alnus firma were preferably high at the vicinity of industrial complex, and those of smilax china, rubus crataegifolius and rhus trichocarpa were similar at every site and it could be guessed that those had a tolerance. Number of species had a difference over 10 species at the vicinity of industrial complex as compared with those of remote sites, and species diversity showed highly at the farther sites of industrial complex, and also at the low layer, number of species, species diversity and evennes were low at the vicinity of industrialcomplex and species weakened to air pollution were disappearing. It was possible that forest vegetation would be changed from pinus spp. to community of a. firma and r. pseudoacacia.

• 한국산업정보학회논문지
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• 제14권1호
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• pp.90-94
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• 2009

본 연구에서는 산업현장에서 직접적으로 활용할 수 있는 시스템에 중심을 둔다. 따라서 본 논문은 산업 실내 환경에 적합한 무선 기반의 원격 측정 시스템 설계에 관한 기초 연구로서 비교적 간단한 실내 온도 측정 시스템을 설계하고 제작하였다. 또한 실내 환경에서의 응용 가능성을 검토하기 위해 측정거리에 따른 특성 분석과 안테나 변경에 따른 성능 차이에 대해 논한다.

• 산업경영시스템학회지
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• 제28권3호
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• pp.75-86
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• 2005

To investigate the fatigue characteristic of upper limbs, this study analyzed RMS(root mean square) and MPF(mean power frequency) value between initial and terminal stages of each experiment condition. And the effect of intermittent endurance time was evaluated using the Borg's CR10 value that was measured for the parts of upper limb. According to the results of ANOVA on RMS value, there were significant difference on the %MVC about push, pull, and down force exertion. Particularly the ANOVA of up force exertion was significant difference on shoulder flexion, elbow flexion and rest time as well as %MVC. The results of ANOVA for MPF value were significant difference on the %MVC in regard of the push and up force exertion. In case of up force exertion, MPF value tended to shift low frequency at all of the experiment conditions. According to the analysis of duty cycle, RMS value considerably increased over 50% duty cycle and as the %MVC increased, the duty cycle affected the increase of RMS value. MPF value for up and down force exertion decreased at 33%, 50% and 67% duty cycle for all of %MVC. Borg CR10 value of hand and forearm were below the 3-point to the 40% of endurance time at 30%MVC and to the 20% of endurance time at 50%MVC with the exception of up force exertion. But Borg CR10 values of upper arm and shoulder at up force exertion were more than 3-point to the 20% of endurance time at 30%MVC and in the start point of endurance time at 50%MVC.

• 대한공업교육학회지
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• 제36권2호
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• pp.181-199
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• 2011

이 연구는 예비 공업교사들의 직업기초능력과 교사효능감이 개인적 배경변인과 관련지어 어느 정도인지 파악하고, 직업기초능력과 교사효능감과의 상관관계를 분석하는데 목적이 있다. 이는 예비 공업교사들의 직업기초능력 이해도와 교사효능감을 신장시키기 위한 예비 교원 양성 프로그램에 기초자료를 제공할 수 있을 것이다. 연구결과는 다음과 같다. 첫째, 예비 공업교사의 교사효능감은 모두 보통(M=3.0)이상으로 나타났으며, 교수효능감(M=3.41)이 개인효능감(M=3.28)보다 다소 높게 나타났다. 배경변인에 따른 교사효능감의 유의한 차이를 분석한 결과, 성별과 전공은 차이가 없는 것으로 나타났으며 학년별에 따른 교사효능감의 교수효능감은 통계적으로 유의미한 차이가 있는 것으로 나타났다. 둘째, 예비 공업교사의 직업기초능력 하위영역은 모두가 평균 3점대로 나타났다. 성별과 학년별은 유의미한 차이는 없는 것으로 나타났으며, 직업기초능력의 글로벌 역량만 유의미한 차이가 있는 것으로 나타났다. 셋째, 예비 공업교사의 성별과 전공은 교사효능감과 직업기초능력 모두가 상관관계가 없는 것으로 나타났으며 학년 변인은 교사효능감(r=.274) 및 직업기초능력(r=.168)과 유의한 정적 상관관계를 보였다. 마지막으로 예비 공업교사의 직업기초능력과 교사효능감은 r=.475로 정적 상관관계가 있는 것으로 나타났다.