• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.144-152
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• 2009

This paper propose highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner for application to wireless communication system. The conventional passive $90^{\circ}C$ power divider and combiner cannot be integrated on MMIC because of their very large circuit size. Therefore, the highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner are required for a development of highly integrated MMIC. In this paper, the highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner employing InGaAs/GaAs HBT were designed, fabricated on GaAs substrate. According to the results, the circuit size of fabricated active $90^{\circ}C$ phase difference power divider and combiner were $1.67{\times}0.87$ mm and $2.42{\times}1.05$ mm, respectively, which were 31.6% and 2.2% of the size of conventional passive branch-line coupler. The output gain division characteristic of proposed divider circuit showed 8.4 dB and 7.9 dB respectively, and output phase difference characteristic showed $-89.3^{\circ}C$. The output gain coupling characteristic of proposed combiner circuit showed 9.4 dB and 10.5 dB respectively, and output phase difference characteristic showed $-92.6^{\circ}C$. The highly miniaturized active $90^{\circ}C$ phase difference power divider and combiner exhibited good RF performances compared with the conventional passive branch-line coupler.

• Journal of Information Technology Services
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• v.18 no.4
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• pp.39-53
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• 2019

This article analyzes the effects of regulation that restrict the conglomerate firms to participate in the public procurement of software. The regulation was implemented in 2013, and this article analyzes five years of firm performance before and after 2013 through DID (difference-in-difference method). In particular, this article analyzes how restrictions on conglomerate firms' participation in public software procurement affect middle and small firms performance. As a result, small-size firms achieve relatively positive results in private sector revenues compared to mid-size firms. However, there was no significant difference between the mid-size and small-size firms in profit margin. This study implies that the new policy is needed to improve the small and medium-size firms revenues on the private market by leveraging the public procurement market which restricted the conglomerate firms to participate. This can be done by complementing the regulation in line with servitization paradigm.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.77-82
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• 2007

This study was conducted to clarify the differences in egg-laying characters of Varied tit (Parus varius) as elevation in the Mt. Jirisan. We set up 144 artificial nest-boxes at three sites located in 300, 900, 1400m in elevation and checked egg size, clutch size and first date of egg-laying. At a result, There was no difference in egg size as elevation. But clutch size at high elevation was lower than at low elevation. Also, first date of egg-laying at high elevation was later than at other sites. In this research, we think that difference of clutch size at three sites result from 'individual adjustment hypothesis' and difference of first date of egg-laying have relation to sprouting date of leaves and distribution of insects.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1161-1167
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• 1999

To investigate the effect of diazepam on fetal development in pregnant rats, this experiment was performed in eighty Sprague-Dawley female rats which were 8 weeks old and grouped into two according to different diazepam treatment period during 5-9 days of gestation and 10-14 days of gestation. Both experimental groups were included by saline treated groups (control) and diazepam-treated groups (6mg, 12mg and 24mg), respectively. Diazepam was injected to pregnant rats subcutaneously, which were sacrified on 20 days of gestation and mean litter size, fetal body weight, fetal crown-rump length (CRL) and pathological findings were examined. 1. Concerning mean litter size, diazepam-treated groups showed lower mean litter size than control in both 5-9 days and 10-14 days of gestation groups(p < 0.05) without difference according to dosage of diazepam and day of gestation. 2. Concerning fetal body weight, diazepam-treated groups during 5-9 days of gestation showed lower fetal body weight than control and the other treated group during 10-14 days(p < 0.01) without difference according to dosage of diazepam. Diazepam-treated group during 10-14 days of gestation showed no difference among experimented groups. 3. Concerning fetal crown-rump length (CRL), diazepam-treated groups during 5-9 days of gestation showed shorter CRL than control and the other treated group during 10-14 days of gestation(p < 0.01) without difference according to dosage of diazepam. 4. Reduction of mean litter size, fetal body weight and CRL was shown from when treated by the dosage of 6mg/kg of diazepam. 5. Maternal mortality according to dosage of the 20mg/kg of diazepam were 30% and 20% in the treated group during 5-9 days and 10-14 days of gestation, respectively. These results indicated that diazepam treatment in pregnant rats caused considerable reduction of mean litter size, fetal body weight and fetal crown-rump length when treated during 5-9 days of gestation.

• The Korean Journal of Health Service Management
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• v.6 no.4
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• pp.111-120
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• 2012

This research analyzes on the factors and difference of the management performance in general hospital. In details, we provide that personnel expenses, materials costs and administrative expenses have impact on management performance in general hospital and these factors have differences by region and sickbed size. The meaningful results of this study as follow. In the first, personnel expenses ratio influence management performance but materials costs ratio and administrative expenses ratio are only partially impact for the management performance. Secondly, in the management performance by region, there are no significant differences between the two groups of the big city and small and medium-sized cities. In personnel expenses ratio, materials costs ratio and administrative expenses ratio, The materials costs ratio is significant difference but ersonne expenses ratio and administrative expenses ratio have no significant difference. Finally, there's no significant difference between the hospital size and management performance. But this study provide that there is partially a difference between personnel expenses ratio, materials costs ratio and administrative expenses ratio and the hospital size.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.128-136
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• 2017

The purpose of this research is to analyze the effects of smart learning in both general education and fisheries & marine education through meta-analysis. To find the effects size, we had collected 112 studies from graduation theses and journal articles. Followings are the results of the research: (a) Smart learning turns out to be more statistically effective comparing to traditional education. The total effect size of smart learning is .768 and the value of U3 is 61.50%. (b) There is no significant difference between general education and fisheries & marine education in the view of effect size. (c) There is a significant difference in subjects, type of publication, and size of members in experimental group. High school student group has the most effect size of smart learning.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.645-650
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• 2007

According to most studies, assessment of aging structure is trend to detect flaw size by sensor than using existing subjective evaluation by expert for objective evaluation. But Uncertainties existing in the sensor make difference between measured flaw size and actual flaw size, In this paper, Probability of Detection(POD) have been used to quantify the uncertainties and POD is updated by relationship measured flaw size and actual flaw size (Heasler, 1990), also we proposed probabilistic updating approach method to improve measurement accuracy(the difference of measured PDF and actual PDF) by using updated POD.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.302-312
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• 2020

This study examined whether there is a difference in cost asymmetry between a corporate listed on KOSDAQ and a corporate listed on KOSPI, and whether there is a difference in cost asymmetry depending on the size of the listed corporate. In the previous study, cost asymmetry was examined only for listed corporate, but the difference in size between KOSDAQ-listed corporate and KOSPI-listed corporate was not examined. However, according to many studies, since the characteristics of corporate and firm risks are different between corporate listed on KOSPI and corporate listed on KOSDAQ, or even for listed corporate, such an impact may affect the decision-making of internal resource allocation. The analysis was conducted that there would be a difference in the impact. For this study, the results of analyzing the KOSPI and KOSDAQ markets from 2011 to 2019 using the cost behavior model of Anderson et al. (2003), There was a difference in cost behavior in the KOSPI and KOSDAQ markets. Overall, as in previous studies, Cost Stickiness was appeared. but in the case of the KOSPI market, Cost Stickiness was mitigated.It was found that corporate with large corporate size made the decision to dispose of idle resources more clearly when sales decreased. In addition, it was observed that the higher the foreign investor's ownership ratio, the KOSPI market, and the larger the corporate size, the more clearly the Stickiness of cost was mitigated. This study expands research on cost asymmetry and reveals that there is a difference between the KOSPI market and the KOSDAQ market, and between the size of the corporate, and has a differentiation from previous studies.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.47-53
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• 2007

The laminar combustion characteristics of interacting coal particles in a convective flow are numerically investigated at particle arrangement and size difference. The numerical simulations, which use the two-step global reaction model to account for the surrounding gas effect, show the detailed interaction among the inter-space particles, undergoing devolatilization and subsequent char burning. Several parametric studies, which include the effect of the gas temperature (1700 K), high pressure(10 atm) and variation in geometrical arrangement of the particle diameter on the volatile release rate and the char combustion rate, have been carried out. The comparison indicates that the shift to the multiple particle arrangement resulted in the substantial change of the combustion characteristics and that the volatile release rate of the interacting coal particles exhibits a strong dependency on the particle spacing and size difference.

• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.64-71
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• 2003

The purpose of this study was to compare the initial apical file(IAF) first Ole that fits to the apex in each canal before and after early flaring to analyze if the size of file to fit to the apex would increase after flaring. Eighty anterior teeth with complete apical formation and patent foramens were selected. The samples were randomly divided into 4 groups(GG, OS, GT, PT Group) of 20 teeth each. A file was fit to the apex in each canal and that size recorded. Radicular flaring were completed using different types of instruments. After flaring a file was again fit to the apex in the same manner as before and its size recorded. The results of this study were as follows : 1. The mean diameter of IAF before flaring(file diameters in $mm{\times}10^{-2}$) was $19.81{\pm}8.32$ before and $25.94{\pm}9.21$ after(p<0.05). 2. The increase in diameter of IAF was approximately one file size for all groups. 3. Ranking of increasing diameter of IAF were GG>CT>OS>PT group. There was a statistically significant difference between before and after flaring(p<0.05). 4 Ranking of the time for flaring were GG>GT>OS>PT group. There was a statistically significant difference between GG group and other groups(p<0.05). 5. In the case without change of IAF diameter, they showed decrease in force after flaring when IAF was pulled out from root canal(p<0.05). This study suggested that early radicular flaring increases the file size that is snug at the apex, and awareness of that difference gives the clinician a better sense of canal size. Early flaring of the canal provides better apical size information and with this awareness, a better decision can be made concerning the appropriate final diameter needed for complete apical shaping.