• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.326-333
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• 2003

In the measurement using DMA and CPC in series, there is some time delay for particles classified in DMA to detect in CPC. During this time, the DMA time-response changes due to the velocity profile of sampling tube and the diffusion of particles in the volume that exists between the DMA exit and the detector of ultra-fine CPC. This is called mixing effect. In the accelerated measurement methods like the TSI -SMPS, the size distribution is obtained from the correlation between the time-varying electrical potential of the DMA and the corresponding particle concentrations sampled in DMA. If the DMA time -response changes during this delay time, this can cause the error of a size distribution measured by this accelerated technique. The kernel function considering this mixing effect using the residence time distribution is proposed by Russell et al. In this study, we obtained a size distribution using this kernel to compare to the result obtained by the commercial accelerated measurement system, TSI -SMPS for verification and considered the errors that result from the mixing effect with the geometric mean diameters of originally sampled particles, using virtually calculated responses obtained with this kernel as input data.

• Youth Facilities and Environment
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• v.16 no.2
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• pp.79-91
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• 2018

This study empirically examined the moderated mediation effect of volunteer time in the effect of school maladjustment on juvenile delinquency through depression as negative emotions. For empirical confirmation, 7,052 individuals were collected by stratified multi-stage cluster sampling among 4th to 6th grade elementary school, 1st to 3rd grade junior high school, and 1st to 3rd grade high school students in May 2015. This data was used for analysis. The results of the analysis are as follows. First, school maladjustment directly affects juvenile delinquency and indirectly influences juvenile delinquency through depression. In other words, the higher the school maladjustment, the higher the juvenile delinquency. Also, the higher the school maladjustment, the higher the depression, and the higher the depression, the higher the juvenile delinquency. Second, the volunteer time has a significant effect on juvenile delinquency through interaction with the depression. In other words, it was proved that the moderated mediation effect of volunteer time in the effect of school maladjustment on juvenile delinquency through depression as negative emotions. Based on this, policy implications were examined.

• Science of Emotion and Sensibility
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• v.16 no.1
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• pp.43-52
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• 2013

"Time versus money effect" refers to a favorable shift in consumers' responses activated by time(vs. money). In general, how people spend their time or money could reflect one's personal identity. Previous research indicates that drawing individuals' attention to time makes more effective in product satisfaction rather than money. Also, whereas because time is experienced as an experience, time activates more positive product satisfaction for experiential product rather than materialistic product, money has the reverse effect because money relates with possessions. Present study examined the effect of time and money on consumers' attitudes and decisions and the role of product type including smartphone. In experiment 1, participants evaluated their experiences or their own products(family restaurant, smartphone, premium jean). They satisfied more with their smartphones when activated by time than by money. In experiment 2, 3 image ads, a promotion image ad for each product(family restaurant, smartphone, premium jean), were offered to find the effect of time and money in promotion ads. The interaction effects between activating condition and product type were revealed on the product attitudes, product satisfaction, purchase intent, and personal connection reflecting the consistent time effect on smartphone. In addition, the main effect of the activating condition was significant which meant time activating ads were more effective than money activating ads.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.87-92
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• 2012

This study examines the relationship between R&D investment and subsequent outputs of the research activity. Usually, there is some time difference between the production of research outputs, such as academic papers and application or registration of patents, and the investment of R&D expenditure. The time lag for producing this kind of research outputs should be considered to evaluate the performance of research activity exactly. The purpose of this study is to identify time lag effect between the times of input and output of a R&D activity and to derive the degree of time lag using the data set of a long term R&D program supported by Korean government. A modified Almon model is suggested to identify the time lag effect between input and output of research activities performed by this program. Time-series cross-section data from 16 research centers between 2001 and 2009 are used to find time lag effect.

• Korean Journal of Pharmacognosy
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• v.14 no.4
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• pp.170-174
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• 1983

To explain the medical effect of 'Pyungwijiyu-Tang' which is mostly used in excremental blood caused by Eum-Gyul(陰結) in oriental medicine. The plasma prothrombin time on mouse dosed 'Pyungwijiyu-Tang', 'Gami-Pyungwjiyu-Tang and Schizonepetae Herba (parched) were revealed the shorten effect, but the plasma prothrombin time on mouse dosed Zingiberis Rhizoma (parched) was not revealed the shorten effect.

• Journal of Technology Innovation
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• v.22 no.1
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• pp.1-22
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• 2014

R&D investment also has a gestation period similar to other investments in economics. The gestation period originates from time lag effect of input and output. Thus it is necessary to consider time lag effects when analyzing the relationship between firms' R&D investment and R&D performance. The main objective of this research is to estimate the length of time lag effect of R&D investment. The Almon distribution lag model was applied to estimate the time lag effect. The firm level panel dataset was established from 2002 to 2009. The net value of R&D investment and the number of patent applications were used to measure R&D input and output, respectively. This method found the estimated time lag to be 1~2 years across all datasets. The same analyses were applied to chemical, metal, electronic, exact science, and machinery industries' data. And we found there were differences among sectors in regard to the time lag effect.

• Journal of Family Resource Management and Policy Review
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• v.16 no.4
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• pp.195-211
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• 2012

The purpose of this study is to investigate the relationship between leisure time and time pressure based on time availability perspective and gender perspective. For this purpose, this study examined the use of leisure time and the level of time pressure according to gender and gender role attitudes and investigated the relationship between leisure time and time pressure focusing on gender differences in the moderating effect of gender role attitudes. The sample for the study was drawn from the Time Use Survey data collected by Korean National Statistical Office in 2009. Two cases were gathered from each of the samples who are married, aged over 20, presently working and raising preschoolers, which makes 3,150 cases in the total. The major findings are as follows. First, the differences of leisure time between groups according to gender role attitude are not significant, but gender differences are significant. Men's leisure time is more than women's leisure time. Secondly, people with progressive gender role attitudes have higher time pressure than people with conservative gender role attitudes. By the gender groups, women's time pressure is higher than men's time pressure. Thirdly, men's time pressure is decreasing as leisure time increases, but effect of leisure time on women's time pressure is not significant. Women with progressive gender role attitudes have higher time pressure than women with conservative gender role attitudes. On the other hand, influence of gender role attitudes on men's time pressure is not significant. Fourthly, only male group has a significant moderating effect of gender role attitudes in the relationship between leisure time and time pressure. In other words, time pressure of men with conservative gender role attitudes is decreasing more sharply than men with progressive gender role attitudes as leisure time increases. In contrast, increased leisure time does not relieve women's time pressure even though they have conservative gender role attitudes. These results show that men's time pressure can be interpreted in the time availability perspective, while women's time pressure can be described in gender perspective.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.1 s.106
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• pp.34-39
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• 2006

For the evaluation of the normalized impact sound pressure level, the reverberation time of the receiving room should be measured. This paper deals with the effect of the time constant of FFT analyzer and the measuring points on reverberation time. It is found that the time constant should be in the range between 10 ms and 35 ms. While the effect of measuring points on the reverberation time is significant when the bandwidth is narrow it is negligible in the evaluation of the normalized impact sound pressure level.

• Journal of Power Electronics
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• v.15 no.2
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• pp.431-442
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• 2015

Dead-time element must be set into space vector pulsed width modulation signals to avoid short circuits of the inverter. However, the dead-time element distorts the output voltage vector, which deteriorates the performance of electrical machine drive system. In this paper, dead-time effect and its compensation control strategy are analyzed. Based on the analysis, the voltage distortion caused by dead-time is regarded as two disturbances imposed on dq axes in the rotor reference frame, which degenerates the current tracking performance. To inhibit the adverse effect caused by the dead-time, a control scheme using two linear extended state observers is proposed. This method provides a strong ability to suppress dead-time effects. Simulations and experiments are conducted on a permanent magnet synchronous motor drive system to demonstrate the effectiveness of the proposed method.

• Journal of Family Resource Management and Policy Review
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• v.23 no.3
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• pp.89-107
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• 2019

This study aimed to examine the impact of academic background on full-time employment and on other important issues concerning job security and care faced by single-parent youths. The study alse aimed to verify the effect of related support on full-time employment. The analysis targeted 262 single parents under 24 years of age who were raising their children, and the main results were as follows: First, the ratio of adulthood was high for those who were employed, and the academic achievement of full-time workers was also significantly high. However, the rate of discontinuities in school was also high among those who were employed, especially those seeking full-time employment, whose desire to stay in school was higher than that of other difficulties of single, teenage parents. Second, the vocational education experience of single, teenage parents was 32 percent overall, and the rate of those seeking full-time employment was also relatively high, reaching 44 percent. However, the results of this study did not verify the direct effect of vocational education experience on full-time employment nor the interaction effect of the academic background. Therefore, a thorough review of the effectiveness of a vocational education program for young, single parents wishing to gain employment is necessary. Third, the overall rate of those who received a public nanny service was 31 percent, while the rate of full-time workers who experienced this service was significantly higher reaching 59 percent. In the research model verification, single parents who received a public nanny service were 3.8 times more likely to get a full-time job than those who did not, and receiving a public nanny service showed a regulatory effect between academic studies and full-time employment. The higher the academic level of the parents, the higher their possibility of full-time employment.