• 해양환경안전학회지
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• 제19권2호
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• pp.213-218
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• 2013

본 연구에서는 자유낙하 하는 쐐기형 구조물의 슬래밍 충격압력 및 유동특성을 알아보고자 실험을 수행하였다. 유동장의 계측은 2-프레임 그레이레벨 상호상관 PIV 기법을 이용하였으며, 자유낙하 하는 구조물의 충격압력은 압력 계측장비인 Dewetron System을 이용하였다. 모델과 자유수면간 이루는 각도는 $15^{\circ}$, $25^{\circ}$, $35^{\circ}$ 및 $45^{\circ}$를 적용하였으며 중량과 자유낙하의 높이에 대해서 다양성을 주어 실험하였다. 속도장은 접수보다 이수에서 빠른 유동특성을 나타냈으며, 접수에서 보다 이수에서 시간이 더 소요됨을 보였으며, 모델 하부에서의 충격압력은 모델의 45도에서 보다, 입수각이 작은 15도와 P1 지점에서 높게 나타났다.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5403-5408
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• 2012

본 논문에서는 신체 성분 분석을 위한 다주파수 생체전기 임피던스 분석법에 대하여 소개하고 이를 기반으로 다주파수 생체전기 임피던스 분석 시스템을 구현하고 그 과정 및 결과를 제시하였다. 시스템의 구성요소들을 다주파수 교류 신호 발생부, 위상 신호 검출부, 전압 신호 검출부, 제어부, 입 출력부, 전극부, 전원부로 구분하여 설명하고, 구체적으로 구현 기법을 소개하였다. 체성분 데이터의 임상적 의의를 검토하고자 세계 최고 수준의 기술을 적용하여 높은 재현도와 고정밀도의 데이터를 제공하는 전문가용 체성분 분석기로 측정한 데이터와 비교 검토하고 두 측정치간의 상관관계를 구한 결과 시스템에 의한 체성분 분석은 상당히 높은 재현성을 나타낸다고 할 수 있다.

• 제어로봇시스템학회논문지
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• 제17권1호
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• pp.61-67
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• 2011

The GPS new civil signal is modulated on the L2 carrier at a frequency of 1227.6MHz. The L2C signal is composed of two multiplexed code signals, which include CM code with a 10,230 chip sequency repeating every 20ms, and CL code which has a 767,250 chip sequency repeating every 1.5 seconds. Thus, the new civil signal have much improved cross correlation properties so that the position fixing can be possible even with very weak signals. However, it requires very long acquisition time because of its long code length. This paper presents an efficient signal acquisition method for L2C AGPS receiver. Snapshot mode and coarse time assistance are assumed and total integration time is given by 1.5 sec. By SNR worksheet and computer simulation, it is proven that L2C signal can be acquired with very weak power less than -150dBm. Considering the acquisition time and the sensitivity, it is recommended that the highest power signal is acquired with CM code first to reduce TTFF. By the timing synchronization, at this time, search space of the code phase for other signals can be greatly reduced so that CL code can be used in signal acquisition to maximize sensitivity with small computation.

• 대한간호학회지
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• 제32권6호
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• pp.792-802
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• 2002

This cross-sectional study was designed to explore the relationship among social support, experienced stressful life events and health behaviors of Korean undergraduate students, and validate the mediator effect of social support. Method: One thousand four hundred fifty-three undergraduate students were randomly selected from five universities located in the middle area of Korea. Result: The health behaviors of Korean undergraduates tend to have unhealthy patterns. In the case of the students living without family, experiencing more stressful life events and perceiving lower social support, health behaviors are poor. The relationship between perceived social supports, the frequency of the experienced stressful life events and the score of health behavior patterns is statistically significant. After controlling the effect of social support, the correlation coefficient between the frequency of experienced stressful life events and the score of health behavior patterns was slightly lower. The score of health behaviors between the group with an extremely high score of social support and the group with an extremely low score were statistically significantly different. Conclusion: Future studies need to be pursued to develop various strategies such as a health education programs and counseling programs for health maintenance and health promotion of undergraduates.

• 대한치과교정학회지
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• 제47권6호
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• pp.365-374
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• 2017

Objective: The objective of this study is to investigate the eruption pattern and root resorption of the bovine anterior dentition in relation to growth-related parameters based on dental maturity. Methods: A cross-sectional study was conducted on 110 bovine anterior mandibles by using standard radiography, cone-beam computed tomography (CBCT), and actual measurements. We determined the relationships between the stages of dental maturity by using a modification of Demirjian's method and various growth-related parameters, such as the activity of the root-resorbing tissue and mobility of the deciduous teeth. The correlation of growth-related parameters with interdental spacing and distal unusual root resorption (DRR) of the deciduous fourth incisor was assessed. The cause of mesial unusual root resorption (MRR) of the deciduous fourth incisor was determined on the basis of the arrangement of the permanent third incisor. Results: An independent t-test and chi-square test indicated significant differences in growth-related parameters associated with dental arch length discrepancy and factors related to the shedding of deciduous teeth between the low and high dental maturity groups. The samples with interdental spacing and DRR showed a larger sum of mesiodistal permanent crown widths and higher dental maturity than did the respective controls. Samples with MRR tended to show a lingually rotated distal tip of the adjacent tooth crown. Conclusions: Dental maturity has relevance to the interdental spaces and unusual root resorption of mixed dentition. The position of the adjacent tooth crown on CBCT may be correlated with the occurrence of unusual root resorption of the incisor.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권10호
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• pp.4968-4986
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• 2017

In this paper, we primarily address the difficulty of automatic generation of a plausible depth map from a single image in an unstructured environment. The aim is to extrapolate a depth map with a more correct, rich, and distinct depth order, which is both quantitatively accurate as well as visually pleasing. Our technique, which is fundamentally based on a preexisting DepthTransfer algorithm, transfers depth information at the level of superpixels. This occurs within a framework that replaces a pixel basis with one of instance-based learning. A vital superpixels feature enhancing matching precision is posterior incorporation of predictive semantic labels into the depth extraction procedure. Finally, a modified Cross Bilateral Filter is leveraged to augment the final depth field. For training and evaluation, experiments were conducted using the Make3D Range Image Dataset and vividly demonstrate that this depth estimation method outperforms state-of-the-art methods for the correlation coefficient metric, mean log10 error and root mean squared error, and achieves comparable performance for the average relative error metric in both efficacy and computational efficiency. This approach can be utilized to automatically convert 2D images into stereo for 3D visualization, producing anaglyph images that are visually superior in realism and simultaneously more immersive.

• Journal of Welding and Joining
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• 제32권6호
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• pp.8-13
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• 2014

One of the main challenges of the automatic arc welding process which has been widely used in various constructions such as steel structures, bridges, autos, motorcycles, construction machinery, ships, offshore structures, pressure vessels, and pipelines is to create specific welding knowledge and techniques with high quality and productivity of the production-based industry. Commercially available automated arc welding systems use simple control techniques that focus on linear system models with a small subset of the larger set of welding parameters, thereby limiting the number of applications that can be automated. However, the correlations of welding parameters and bead geometry as welding quality have mostly been linked by a trial and error method to adjust the welding parameters. In addition, the systematic correlation between these parameters have not been identified yet. To solve such problems, a new or modified models to determine the welding parameters for tandem GMA (Gas Metal Arc) welding process is required. In this study, A new predictive model called STACO model, has been proposed. Based on the experimental results, STACO model was developed with the help of a standard statistical package program, MINITAB software and MATLAB software. Cross-comparative analysis has been applied to verify the reliability of the developed model.

• International Journal of Advanced Culture Technology
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• 제6권2호
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• pp.72-79
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• 2018

The purpose of this study was to analyze general characteristics and empathy factors of nursing student's major satisfaction. Participants in this study were 235 students from both located in J do and C do Universities. The research method was a cross-sectional survey and the survey period was from September 1 to 10, 2017. The questionnaire was used to investigate general characteristics, empathy, and major satisfaction. The analysis was based on frequency analysis, p value of t or F value, Pearson correlation, regression analysis, and hierarchical regression analysis using SPSS 18.0. The result of this study were as follows: (1) The C University showed higher satisfaction than J University(3.44), (2) the factors affecting major satisfaction were school location, grade, religion, cognitive empathy, and emotional empathy correlated, Regression analysis was used to examine factors that correlated with major satisfaction, followed by hierarchical regression analysis to identify the most influential factors. (3) The result of the analysis showed that the greatest influence factors on major satisfaction were the University location(${\beta}=.325$, p<.01), the cognitive empathy (${\beta}=.287$, p<.01), and the next order was negative grade(${\beta}=-.230$, p<.01). Based on the results of this stud, the following conclusions can be drawn. The most influential factor in the major satisfaction was the school location, but this was an irreversible factor. Therefore, if the cognitive empathy factor and grades are corrected, it can be said that it can increase the satisfaction of major in nursing University students. In this study, it was emphasized that cognitive empathy contained in the course of nursing education program and suggested guidance on major satisfaction in lower grades.

• 한국해안·해양공학회논문집
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• 제21권1호
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• pp.54-62
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• 2009

본 연구에서는 소파블록피복 케이슨 방파제 후면으로 떨어지는 월파의 거동을 분석하기 위하여 수리모형실험을 수행하였다. 방파제 후면으로 낙하하는 월파는 배후사면으로 내습하며 배후사면의 안정성에 직접적인 영향을 준다. 본 연구에서는 배후면에서의 월파거동을 검토하기 위해 월파의 전면유속, 파형 및 관입거리를 측정하였으며, 다양한 파랑조건에 대한 월파의 특성변화를 비교 분석하였다. 수리모형실험은 파랑조건과의 상관성에 초점을 두기 위해 규칙파를 대상으로 하였으며, 월파수괴의 전면유속, 파형, 관입거리를 측정하기 위하여 그림자기법과 교차상관기법을 응용한 화상유속기법을 이용하여 측정하였다. 실험결과에 의하면 배후면에서 월파의 관입거리와 유속은 입사파의 주기와 파고가 커짐에 따라 증가함을 알 수 있었으며, 무차원변수 사이의 상사관계로부터 유속 및 거리분포에 대한 경험식을 유도하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2010년도 춘계학술대회
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• pp.389-391
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• 2010

자유수면에 접한 원형실린더는 후류유동에 변화를 초래한다. 이를 위해 희류수조의 수면하 깊이를 변화시키며 $Re=1.0\times10^3$에서 순간유동장을 계측하여 실험을 통하여 그 영향을 조사하였다. 계측된 결과는 상호상관 PIV기법을 이용하여 원형실린더의 2차원 유동특성을 알아보기 위하여 상호 비교하였다. 자유수면에 의한 원형실린더 주변유동은 후류에 영향을 미친다. 특히 d=l.0D의 경우에 있어서 경계층은 전체 영역에 걸쳐 분포하였다. 원형실린더의 박리점과 경계층은 수심의 깊이에 따라 제어가 가능하였다.