• 유통과학연구
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• 제13권8호
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• pp.81-90
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• 2015

Purpose - To vitalize a market or develop a new one, companies frequently release new products into the market, often by shortening the time to market, called the release period. This research aims to investigate the purchase intention behavior of consumers in terms of buying new products at the time of product release based on the release speed. Research Design, Data, and Methodology - The research reviews the influence of relative advantage, complexity, and compatibility among innovative attributes of new products, as proposed by Rogers. Moreover, it examines the moderating effect of the innovative new product attributes in terms of speed of obsolescence of old products and how that influences consumer purchase behavior. Additionally, this study tests the research hypotheses using empirical analysis. Results - The analysis demonstrated that the relative predominance (H1) and suitability (H3) of new products had a statistically significant positive influence on new product purchase intention. However, the complexity (H2) of new products had a statistically significant positive influence on new product purchase intention in contrast to its predicted sign (-). The results of the moderating effect of the old product use period were as follows. H4-1 was not supported since the difference between the path coefficients of the group with the low level old product use period and the group with the high level, represented by the relationship of relative predominance and new product purchase intention, was not statistically significant. H5-1 was also not supported since the difference between the path coefficients of the group with the low level of old product use period and the group with the high level, represented by the relationship of complexity and new product purchase intention, was not statistically significant. However, H4-2 was supported since the difference between the path coefficients of the group with the low level of old product use frequency and the group with the high level, represented by the relationship of relative advantage and new product purchase intention was statistically significant. H5-2 was not supported since the difference between the path coefficients of the group with the low level of old product use frequency and the group with the high level, represented by the relationship of complexity and new product purchase intention, was not statistically significant. H6-2 was also not supported since the difference between the path coefficients of the group with the low level of old product use frequency and the group with the high level, represented by the relationship of compatibility and new product purchase intention, was not statistically significant. Conclusion - According to the results, only H4-2 among the hypotheses on the moderating effect of the old product use period and use frequency was statistically significant. Future research should focus on carrying out a detailed review of the hypothesis on the moderating effect of the old product usage period and frequency, find the cause, and connect this to potential new research.

• Journal of Preventive Medicine and Public Health
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• 제21권1호
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• pp.99-112
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• 1988

1개 의과대학 본과 제 1,2,3학년 279명을 대상으로 1987년 3월중순부터 4월초순에 걸쳐 프레밍헴 A형행동양상척도(FTA)의 신뢰도와 타당도 그리고 사회심리학적인 변수와 혈압과의 관계를 조사해서 다음의 결과를 얻었다. SCL-90-R과 FTA의 신뢰도는 $0.57{\sim}0.91$의 범위였고 FTA의 요인분석에서 정열적경쟁요인(hard-driving competitiveness factor)과 조급요인(impatience factor)이 추출되었다. FTA의 총점은 비교체중이 클수록, 농촌출신이면 높은 경향을 보였으나 유의성은 없었고 SCL90-R과는 우울, 불안, 적대감, 편집증, 정신증하위척도와 비교적 낮은 유의한 정상관관계를 보였다. 혈압과의 단일 변수 분석에서 수축기혈압은 남자에서 비교체중과 가족력이 유의했고 남녀 공히 경제상태에 따른 차이가 있었다. 확장기혈압은 남자에서 비교체중과 음주량이 유의했고 여자에서는 비교체중이 유의한 상관관계를 보였다. 비교 체중의 영향을 제거하고서는 남자에서 음주량이 확장기혈압과 경제상태가 수축기혈압과 유의한 관계를 보였다. 단계적추가분석법에 의한 중회귀분석 결과 남자에서는 수축기혈압에서 비교체중과 경제상태가 중요변수로 선정되었고 확장기혈압에서는 비교체중과 음주량이 선정되었다. Alpha가 0.1수준에서는 수축기혈압에 SCL-90-R의 우울증 하위척도가 추가 선정되었다. 여자에서 수축기혈압은 경제상태와 비교체중이 선정되었고 확장기혈압에서도 비교체중이 선정되었으나 대상자 수가 적어서 불안정했다. FTA와 혈압과는 남녀 공히 관련이 없었다.

• International Journal of Control, Automation, and Systems
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• 제6권2호
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• pp.180-185
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• 2008

A new method for relative error continuous and discrete time model order reduction is proposed. The reduction technique is based on two recently developed methods, namely frequency domain balanced truncation within a frequency bound and inner-outer factorization techniques. The proposed method is of interest for practical model order reduction because in this context it shows to keep the accuracy of the approximation as high as possible without sacrificing the computational efficiency. Numerical results show the accuracy and efficiency enhancement of the method.

• Nutrition Research and Practice
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• 제4권2호
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• pp.142-148
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• 2010

The food frequency questionnaire (FFQ) has been used as an important dietary assessment tool in epidemiologic studies, but the usefulness of the FFQ has been debated in recent years. This study was performed to evaluate the relative validities of 3-day food records and the semi-quantitative FFQ. A total of 124 subjects finished 3-day food records (FRs) during each of the four seasons, as well as the FFQ from December 2002 to May 2004. The FFQ was a food based semi-quantitative FFQ including 103 items. Three-day FRs from each season and a randomly selected season were compared with the remaining 9-day FRs. The remaining 9-day FRs, as a reference measurement, were also compared with the FFQ. Pearson's correlation coefficients between the 3-day FRs and the 9-day FRs were between 0.14 and 0.56. Pearson's correlation coefficients between the FFQ and the 9-day FRs ranged between 0.07 and 0.41. Average proportions of classification into the same quartiles, adjacent quartiles, and distant quartiles between the 3-day FRs and the 9-day FRs were 35.8%, 40.5%, and 5.2%, respectively. On average, the proportions of classification into the same quartiles, adjacent quartiles, and distant quartiles between the FFQ and the 9-day FRs were 31.1%, 39.4%, and 6.9%, respectively. Three-day FRs showed higher correlations and higher agreement proportions of quartile classification with the 9-day FRs than did the FFQ, but both relative validities of 3-day FRs and the FFQ appear to be acceptable as dietary assessment tools. Further studies for validating food intake by reliable biomarkers are necessary.

• 혜화의학회지
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• 제22권2호
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• pp.81-92
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• 2014

Objective : The purpose of this study was to assess the effects of Cyperus rotundus L. essential oil on relaxation in highly stressed volunteers with heart rate variability(HRV) and electroencephalography(EEG). Methods : 11 highly stressed volunteers participated in this study. The volunteers were examined with HRV and EEG before and after inhalation of Cyperus rotundus L. essential oil. Results : After smelling Cyperus rotundus L. essential oil, mean RR(mean of RR intervals) was incresed significantly(p<0.01), mean HRV(mean of heart rate), HF(high frequency) were decreased significantly(p<0.01). norm LF(low frequency), LF/HF ratio were decreased significantly(p<0.05), norm HF(normalized high frequency) was increased significantly(p<0.05) on HRV. After smelling Cyperus rotundus L. essential oil, relative ${\theta}$ power was decreased significantly(p<0.05) at P3(left parietal) and relative ${\alpha}$ power was increased significantly(p<0.05) at Fp1(left prefrontal), Fp2(right prefrontal) and relative ${\beta}$ power was decreased significantly(p<0.05) at Fp1(left prefrontal) and relative ${\gamma}$ power was decreased significantly(p<0.05) at Fp1(left prefrontal) on EEG. Conclusions : This results show that inhalation of Cyperus rotundus L. essential oil effects on relaxation and decreasing stress.

• International Journal of Fluid Machinery and Systems
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• 제9권4호
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• pp.338-353
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• 2016

Information on the surge behaviors and stall stagnation boundaries for a nine-stage axial flow compressor are summarized on the basis of analytical data in comparison with those for a single-stage one, with attention to the pressure ratio effect. The general trends of the surge loop behaviors of the pressure-mass flow are similar for both compressors including the fact that the subharmonic surges tend to appear very near the stall stagnation boundaries. With respect to the nine-stage compressor, however, the mild loops in the subharmonic surges tend to be very small in size relative to the deep loops, and at the same time, insufficient surge recovery phenomenon, which is a kind of subharmonic surge, appears also far from the stagnation boundary for relatively short delivery flow-paths. The latter is found to be a rear-stage surge caused by unstalling and re-stalling of the rear stages with the front-stages kept in stall in the stalled condition of the whole compressor, which situation is caused by stage-wise mismatching in the bottom pressure levels of the in-stall multi-stage compressor. The fundamental information on the stall stagnation boundaries is given by a group of normalized geometrical parameters including relative delivery flow-path length, relative suction flow-path length, and sectional area-pressure ratio, and by another group of normalized frequency parameters including relative surge frequencies, modified reduced resonance frequencies, and modified reduced surge frequencies. Respective groups of the normalized parameters show very similar tendency of behaviors for the nine-stage compressor and the single-stage compressor. The modified reduced resonance frequency could be the more reasonable parameter suggesting the flow-induced oscillation nature of the surge phenomena. It could give the stall stagnation boundary in a more unified manner than the Greitzer's B parameter.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 춘계 학술발표회 논문집
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• pp.51-58
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• 2002

The relative site amplification factors in southern Korea were determined from coda waves using coda normalization method. The seismograms of 15 events at 79 stations were used in this study. Seismogram envelopes were obtained by the Hilbert transform of bandpass-filtered velocity seismograms with frequency bands at 1-2Hz, 2-4Hz, 4-8Hz, 8-l6Hz and 16-32Hz. The envelopes were stabilized by application of moving-average scheme with time window of 1 second. The relative amplitudes of seismogram envelope were computed by dividing the amplitude of seismogram envelope at one site by the amplitude of seismogram envelope at reference site. The relative site amplification factors were obtained by taking averages of the relative amplitude. Values of relative site amplification factors in southern Korea are generally low in western area and high in eastern area.

• 한국통신학회논문지
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• 제29권8C호
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• pp.1104-1112
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• 2004

본 논문에서는 레이저와 고속 CCD 카메라를 이용하여 대형 구조물의 3차원 거동 계측을 위해 진동 주파수 계측 방식을 확립하였다. 구조물에 부착한 대상판에 변동(fluctuation)이 작은 다이오드 레이저를 투사하고, 고속 CCD 카메라로 촬영한 영상에 고정도 상대측정 알고리즘을 적용하여 구조물의 변위를 측정하였다. 초당 120 프레임의 고속 카메라를 이용하고 변위에 FFT를 취해 진동주파수를 구한 경우, 0에서 40Hz까지 $\pm$0.5% 이내의 진동주파수의 정확도를 얻을 수 있다. 이를 이용하면 대형 구조물에 대해 보다 저렴하고 간단하게 고유진동수의 측정이 가능하다. 또한 GPS를 이용한 상대측위 기법과의 비교를 통해 레이저를 이용한 변위측정의 정확도를 입증함으로써, 제안한 진동주파수 측정 방법의 신뢰도와 경제성을 검증하였다.

• 한국자동차공학회논문집
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• 제15권6호
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• pp.108-113
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• 2007

This study aims to find equivalent comfort contours, reciprocal of frequency weighting curves, for vertical steering wheel vibration. Psychophysical responses were measured from twelve male subjects by using magnitude estimation of relative discomfort due to vertical steering wheel vibrations of magnitude of 0.1 to 1.58 $m/s^2$ in the frequency range of 4 to 250 Hz. Relative discomfort were estimated with a reference vibration of 0.4 $m/s^2$ at 31.5 Hz. Equivalent comfort contours were produced from the median of sensation magnitudes judged by twelve subjects, which showed variation in the shapes with increase of vibration magnitude. A shape of the contour came close to the perception threshold curve with decrease of vibration magnitude. When the vibration magnitude increases, the shape changed close to those in the references of Hong and et al (2003). It is also recommended frequency weighting curves for vertical steering wheel vibration must be expressed as a function of vibration magnitude as well as frequency.

• 한국콘텐츠학회논문지
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• 제4권4호
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• pp.171-178
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• 2004

라디오 주파수 마이크로파는 시료에서 포도당 농도를 측정하기 위해 사용될 수 있다. 본 논문에서는 포도당을 포함하는 증류수, 샐라인, 인체 씨럼, 인체 혈액 용액에 대해서 상대 유전율을 측정함으로써 포도당 농도 측정의 예비 실험 결과를 보고한다. 근육과 같은 인체 조직의 포도당 농도 측정에서 마이크로파 방법은 NIR방법보다 투과 깊이가 약 100배 더 컸으며, 이것은 인체의 포도당을 비침습적인 검출에 더 유용한 장점이 된다. 실험에서 인체 혈액 용액에서 포도당 농도를 검출하기 위한 측정 감도는 5.8GHz부근에서 약 57mg/dl를 보였다.