In order to identify changes in the nature of the particles due to changes in the inflow rate of the raw material solution, the present study was intended to prepare nano-sized cobalt oxide (Co3O4) powder with an average particle size of 50 nm or less by spray pyrolysis reaction using raw cobalt chloride solution. As the inflow rate of the raw material solution increased, droplets formed by the pyrolysis reaction showed more divided form and the particle size distribution was more uneven. As the inflow rate of the solution increased from 2 to 10 ml/min, the average particle size of the formed particles increased from about 25 nm to 40 nm, while the average particle size did not show significant changes when the inflow rate increased from 10 to 50 ml/min. XRD analysis showed that the intensity of the XRD peaks increased remarkably when the inflow rate of the solution increased from 2 to 10 ml/min. On the other hand, the peak intensity stayed almost constant when the inflow rate increased from 10 to 50 ml/min. With the increase in the inflow rate from 2 to 10 ml/min, the specific surface area of the particles decreased by approximately 20 %. On the contrary, the specific surface area stayed constant when the inflow rate increased from 10 to 50 ml/min.

When weapon system is designed and developed, a reliability is one of important factors to determine the development goal. The reliability analysis of the weapon system and equipment is based on MIL Specification, MIL-HDBK-217F and MIL-HDBK-338B. And the weapon system is operated on various environments by operating concept of the military using the weapon system. This study, at first, present failure rate by PSA comparing with failure rates by PCM, the different reliability analysis method, for same CCA(Circuit Card Assembly). And the study present change of reliability analysis results for CCA on various operation environment condition..

Background: Functional capacity evaluations (FCEs) are designed to systematically assess the capacity to perform work-related tasks and to determine worker’s ability to return to the previous job following work-related injuries. These evaluations may be rated either by clinician or worker. There has been a lack of consensus between the two scoring methods. Objects: This study aimed: 1) to confirm if the data are fit to the Rasch rating scale model and 2) to investigate the item-level concordance rate between the ratings of clinician and injured worker of the FCE. Methods: A cross-sectional study was conducted with a sample (n=124) of a rehabilitation program with the Occupational Rehabilitation Data Base for workers with low back pain. The functional capacity evaluation at admission and discharge was administered to clinicians and workers. The data were analyzed using both classical test theory-based Pearson’s r and intra-class coefficient followed by item-level analysis with Rasch rating scale model. Results: All items of the FCE, except sitting items rated by clinician at admission and handling items rated by both clinician and worker throughout admission and discharge, were acceptable fit statistics with minor out of ranges for a misfit criterion. This may indicate that the items of the FCE overall fit to the Rasch rating scale model. Few problematic items responding differently to clinician and worker both at admission and discharge were detected with the differential item functioning analysis despite the excellent concordance rate using the two conventional statistics-sitting and handling items at admission and handling item at discharge. Conclusion: The item-level speculations using Rasch analysis of the FCE demonstrate that the ratings of clinician and self ratings of worker were psychometrically acceptable though there was an apparent discrepancy between the raters both at admission and discharge.

Recently, graphene oxide (GO) has been extensively investigated for gas and liquid separation because thin-film GO membranes show quite interesting separation performance. However, even GO membranes exhibit relatively low gas permeability due to high tortuosity caused by high aspect ratio of GO. Normally, the size of GO is in the range from a few hundred nanometers to a few micrometers, so inherent gas permeability would be very varied. For practical applications of GO membranes, the gas permeability should be improved. As such, in this study, we have modified the pristine GO sheets to reduce the gas permeation pathway, with maintaining GO’s excellent gas separation properties. This study will provide a further insight on how such two-dimensional nanosheets can be used for membrane applications, competing with existing membrane materials.

Differences in sugar and salt diffusion rates of cabbage depending on size and part were examined. Whole, 3x3 and 5×5 cube sliced cabbage examined indifferent pickling condition (salt 2, 4, 6, 8% and sugar 5, 10, 15, 20% brix). After 12hr storage, salt absorption depending on part was determined to be higher in leaf, followed by stem in all salt solution. Sugar distribution was also determined to be higher in leaf, followed by stem, showing same trend with salt diffusion. Salt diffusion was found to be highest in 3×3 sliced cabbage. Where as 5×5 sliced cabbage and then whole cabbage showed lower diffusion rate in all brix sugar solution. Size dependent sugar diffusion showed same tendency with size dependent salt diffusion. Also, increase in salt and sugar concentration led to increase in salt and sugar permeation rate.

The aim of this study was to compare the appearance rate of vaginal cytology during estrous cycle in small pet bitches. A characteristic features of vaginal cytology during the estrous cycle were the high proportion of superficial cell in proestrus, anuclear cell in estrus, small intermediate cell in diestrus, and small intermediate cell in anestrus, respectively. There were no statistically significant differences of appearance rate of vaginal cytology among small pet bitches in the each phase of estrous cycle. These results indicated that the vaginal cytology was useful method for estimating estrous cycle and optimal breeding time in small pet bitches.

본 논문은 깊이 카메라(Creative Senz3D)를 이용하여 호흡률을 측정하는 것에 대한 정확도와 영향을 미치는 요인들 을 분석하였다. 영향 요인 분석에서는 깊이 카메라가 가지는 깊이 값에 대한 오차와 노이즈 그리고 주위 조도의 영향에 대하여 실험 연구를 진행하였다. 그 결과 깊이 카메라와 측정 대상의 거리가 증가함에 따라 깊이 값의 오차가 증가하였 고 깊이 영상의 오른쪽은 실제 거리보다 깊이 값이 크게 측정되고 왼쪽은 실제 거리보다 깊이 값이 작게 측정되었다. 이에 따라 깊이 값이 영상의 영역에 따라 비대칭성을 가지고 있음을 알 수 있었다. 깊이 카메라와 측정 대상의 각도가 틀어짐에 따라서도 깊이 값의 차의 오차가 증가하였으며 깊이 카메라의 노이즈는 측정 거리가 멀어짐에 따라 점점 증가하였고 노이즈를 측정하는 윈도우의 크기가 증가함에 따라 감소하였다. 주위 조도는 깊이 값에 영향을 주지 않았다. 또한 실제 상황에서 사람을 대상으로 20회 호흡을 하게 하여 깊이 카메라를 이용해 호흡률을 측정하였고 호흡률이 제대로 측정됨을 확인하였다.

The regulation for industrial accident rate level assessment of construction companies was introduced to the construction industry in the Republic of Korea since 1993 and has brought positive outcome on industrial accidents reduction at construction work sites. There were considerable decrease of industrial accident ratio and enforcing of contrators' safety organizations from the beginning of the regulation for industrial accident rate level assessment. In spite of these positive outcomes, there were some negative effects such as contractors' shrinking accident reports to keep good accident ratios since these figures had a great impact on pre-qualification stage of bidding when general contractors were competing for new construction projects. In addition, Comprehensive evaluation bid system, which replaces the lowest price bid system is applied to government-ordered construction projects since 2016. Comprehensive evaluation bid system includes construction company's accident rate as one of the evaluation items and carries out with the industrial accident rate level assessment of construction companies at the same time. The regulations of two systems have been called for improvement to unify these different procedures and standards which have led business stakeholders to confusion for several years. This study aims to devote on lessening shrinking accident reports and to reduce the waste of business stakeholders through changing the regulation for industrial accident rate level assessment.

본 연구는 울산항의 정박지 규모의 적정성을 평가하기 위한 방법을 제시하고, 이를 통해 현재 뿐만 아니라 항만개발에 따른 미래의 정박지 규모의 적정성을 분석하는데 그 목적이 있다. 이를 위해 울산항의 정박지 적정성 평가를 위한 정박지 가동률 개념을 제시하였다. 그리고 이 가동률 개념을 울산항의 2014년 정박지에 적용하여 가동률을 계산한 결과 모든 정박지에서 가동률이 100 %를 넘지 않는 것으로 도출되어, 추가 정박지 지정이 필요하지 않은 것으로 분석되었다. 또한 울산항의 2020년 가동률을 추정한 결과 E1정박지가 168.3 %로 가장 높았으며, E3정박지가 131.1 %, E2정박지가 118.5 %, 그리고 M정박지가 108.7 %인 것으로 계산되어, 2020년에는 정박지가 부족할 것으로 판단된다. 따라서 울산항의 항만개발에 따른 정박지 가동률을 100 % 수준으로 낮추기 위해서는 E1정박지는 11척, E2정박지는 1척, E3정박지는 2척, M정박지는 1척이 추가적으로 정박할 수 있는 수역이 필요할 것으로 분석되었다.

In order to guarantee reliability of the environmental testing on defense systems, it is important to use test equipment that meets requirements of the related test standards. Especially with regard to the rain test method in MIL-STD-810G w/change 1, the latest standard, it has been highly needed to introduce a novel technique and system to provide droplet-size and precipitation-rate conditions. In this study, droplet-diameter spectra of various nozzles were measured by a high-speed camera. Then, a pair of nozzles were selected based on the experimental results showing the spectra lie within the range from 0.5 mm to 4.5 mm, as suggested in the rain test method. Also, the flow-precipitation rate calibration system was developed to precisely correlate the precipitation rate measured in the chamber and the flow rate into the nozzle bank. In conclusion, the rain test equipment has been successfully developed fulfilling the requirements of the test standard.