• International Journal of Aeronautical and Space Sciences
• /
• 제13권2호
• /
• pp.199-209
• /
• 2012

An advanced aeroelastic formulation for flutter analyses is presented in this paper. Refined 1D structural models were coupled with the doublet lattice method, and the g-method was used for flutter analyses. Structural models were developed in the framework of the Carrera Unified Formulation (CUF). Higher-order 1D structural models were obtained by using Taylor-like expansions of the cross-section displacement field of the structure. The order (N) of the expansion was considered as a free parameter since it can be arbitrarily chosen as an input of the analysis. Convergence studies on the order of the structural model can be straightforwardly conducted in order to establish the proper 1D structural model for a given problem. Flutter analyses were conducted on several wing configurations and the results were compared to those from literature. Results show the enhanced capabilities of CUF 1D in dealing with the flutter analysis of typical wing structures with high accuracy and low computational costs.

• International Journal of Precision Engineering and Manufacturing
• /
• 제9권2호
• /
• pp.50-53
• /
• 2008

A design approach using a one-dimensional (1D) lumped model was studied and applied to an industrial inkjet printing head design for micro patterning on printed circuit boards. For an accurate analysis, a three-dimensional piezoelectric-driven actuator model was analyzed and its jetting characteristics were applied to 1Danalysis model. The performance of the 1D lumped model was verified by comparing measured and simulated results. The developed 1D model helped to optimize the design and configuration of the inkjet head and could be implemented in the design of multi-nozzle inkjet printing heads to improve the jetting frequency and minimize crosstalk.

• 대한시과학회지
• /
• 제20권4호
• /
• pp.413-420
• /
• 2018

목적 : MR8 로 제조된 안경렌즈에서 굴절력별로 나누어 투과율을 측정하여 광학적 시험 및 청광 영역을 David L.의 분석법을 적용하여 분석하였다. 방법 : 시중에서 판매되고 있는 MR8 로 제조된 -8.00D, -7.00D, -6.00D, -5.00D, -4.00D, -3.00D, 0.00D의 렌즈를 선정하여 UV-VIS Spectrophotometers(SolidSpec 3700)로 200~1000nm까지 5nm 간격으로 투과율을 측정하고, 청광영역(380~500nm)을 David L.의 청광분석 방법을 적용하여 분석하였다. 결과 : 연구에 선정한 MR8렌즈들 모두 UV영역을 거의 모두 차단하였다. -8.00D의 렌즈가 청광영역에서 투과율 59.56%로 가장 낮게 측정되었고 또한, David L. 분석에 따른 청광영역1과 2에서 낮은 값이 측정되었다. 적외선 영역에서는 모든 렌즈의 투과율이 점진적으로 감소하였다. 그리고 시감투과율에서 평균 23.67%~26.33%의 계산값을 얻었고 -4.00D부터 점진적으로 감소하였다. 결론 : David L.의 분석법을 적용하면, 청광 1영역에서는 최소 41.28%, 최대 46.60%가 측정되었으며, 청광 2영역에서는 최소 87.30%, 최대 97.55%가 측정되었다. 그리고 청광 3영역에서는 최소 86.83%, 최대 96.55%가 측정되었으며 평균 94%였다. 시감투과율에서는 측정된 렌즈 중 -3.00D렌즈가 26.33%으로 가장 높은 값이 계산되었으며, -8.00D렌즈가 23.67%으로 가장 낮은 계산 값을 얻었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제39권4호
• /
• pp.168-174
• /
• 2013

Objectives: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. Materials and Methods: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. Results: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). Conclusion: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.

• Animal cells and systems
• /
• 제4권1호
• /
• pp.1-7
• /
• 2000

The genus Dendronephthya, generally known as soft corals, is reported as an abundant and variable taxon. They mostly distribute in warmer waters of the Undo-Pacific Ocean region including Korea. In spite of their abundance and ecological importance as habitats of marine organisms, there are difficulties in the study of their identification and systematics because they have morphological variabilities and limited taxonomec characters. To resolve the problems, we attempted to elucidate the genetic relationships in the genus Dendronephthya by using random amplified polymorphic DNA (RAPD) analysis. This study was based on eight dendronephthian species and one Alcyoniidae species, Alcyonium gracillimum, as an outgroup. The results from all analysis suggest that they could be classified into four groups by the growth form and the anthocodial grades as follows: the first one,D. putteri and D. suensoni with the divaricate form and VI grade; the second one,D. sp.1 and D. sp.2 with the divaricate form and III or IV grade; the third one, D. gigantea and D. aurea being closer than D. spinifera with the glomerate form and III grade; the last one, D. castanea related to D. gigantea rather than D. putteri with the umbellate form and IV grade. Moreover, the divaricate form was separated from the group of the glomerate and umbellate form. At the intraspecies level, the types of the D. castanea, D. gigantea and D. spinifera were separated depending on the feature of spicules in the polyp head, and the coloration could not influence genetic variation. From this study, we can confirm that their morphological characters are compatible with the genetic variation, also RAPD analysis is a very useful method for resolving the systematic relationships of den-deonephthians.

• 아태비즈니스연구
• /
• 제10권2호
• /
• pp.1-12
• /
• 2019

Collaborative research and development (R&D) has been encouraged based on the belief that knowledge spill-over is mutually beneficial for partners. Although the benefits are supported by science and technology policy research, the risk of R&D collaboration has not been extensively discussed. Two independent studies suggest that there are risks associated with the overuse of collaborative research frameworks. Two sets of R&D collaboration data were analyzed: between the national bio-technology research program and 1) Data Envelop Analysis (DEA), and 2) between Stochastic Frontier Analysis (SFA). In the case of SFA, output measures were integrated into a single output, with weights extracted from research programme managers' responses to the questionnaire. While the DEA result demonstrated the inefficiency of collaborative research, SFA did not. Unlike previous research highlighting risks associated with disclosing proprietary R&D and potential conflict of interest, our study indicates that the transaction's social cost affects collaborative research efficiency. Therefore, governments promoting R&D collaborations should be carefully managed, and policy makers must reconsider the strict conditions governing compulsory collaborative R&D programs.

• 사상체질의학회지
• /
• 제20권1호
• /
• pp.42-47
• /
• 2008

1. Objectives The Body Shape and Feature is one of the important standard for classification of Sasang Constitutions. In order to evaluate one's Body Shape and Feature objectively we have been developing the Body Measuring Machine. Now we develop the 3D Automatic Body Measuring Machine(3D-ABMM). So we make an analysis of the 3D-ABMM's Accuracy. 2. Methods By using the 3D-ABMM and Vivid 9i(3D laser scanner, Konica Minolta) we have a surface scan of the three objects which are the upper body of the female and male Manikin and a male model. We overlap each scan data using the RapidForm2006 (3D scan data solution, INUS Technology) and calculate the average distance and standard deviation between the same point of each scan data. 3. Results and Conclusions In the female Manikin, the average distance is 0.84mm and the standard deviation is 1.16mm and the maximum distance is 10.68mm. In the male Manikin, the average distance is 1.12mm and the standard deviation is 1.19mm and the maximum distance is 12.00mm. In the male model, the average distance is 3.26mm and the standard deviation is 2.59mm and the maximum distance is 12.75mm. From the results, 3D-ABMM has good accuracy for scanning body and will be a usable hardware of the 3D Automatic Body Analysis Machine.

• ETRI Journal
• /
• 제31권1호
• /
• pp.1-9
• /
• 2009

Frequency domain analysis is a fundamental procedure for understanding the characteristics of visual data. Several studies have been conducted with 2D videos, but analysis of stereoscopic 3D videos is rarely carried out. In this paper, we derive the Fourier transform of a simplified 3D video signal and analyze how a 3D video is influenced by disparity and motion in terms of temporal aliasing. It is already known that object motion affects temporal frequency characteristics of a time-varying image sequence. In our analysis, we show that a 3D video is influenced not only by motion but also by disparity. Based on this conclusion, we present a temporal anti-aliasing filter for a 3D video. Since the human process of depth perception mainly determines the quality of a reproduced 3D image, 2D image processing techniques are not directly applicable to 3D images. The analysis presented in this paper will be useful for reducing undesirable visual artifacts in 3D video as well as for assisting the development of relevant technologies.

• 전기전자학회논문지
• /
• 제2권1호
• /
• pp.160-165
• /
• 1998

본 연구에서는 2차원 자계 해석 프로그램을 이용하여 평판형 브러시레스 직류 전동기의 자계 해석을 위한 방법을 제시하였다. 정확한 자계 해석을 위해서는 3차원 자계 해석이 필요하지만 많은 시간 및 비용이 요구되는 단점이 있다. 따라서 본 연구에서는 자계 해석을 위하여 3차원 문제를 해당 자석의 평균 반지름에 대한 원통방향의 단면으로 해석하여 2차원 경계치 문제로 축소시켰다. 본 방법을 이용할 경우 시스템의 크기 및 형태에 관계없이 정확한 2차원 자계해석 결과가 합리적으로 얻어지게 된다.

• 한국해양공학회지
• /
• 제34권6호
• /
• pp.461-468
• /
• 2020

This study examined how national research and development (R&D) in the domain of logistics has changed recently in the Republic of Korea. We conducted basic statistical analysis and social network analysis on 5,327 logistics-related R&D projects undertaken during 2005-2019. Data for performing these analyses were collected from the R&D database of the National Science and Technology Information Service (NTIS). By constructing a co-occurrence matrix with keywords, we conducted degree and betweenness centrality analysis and visualized the network matrix to display a cluster map. This study presents our observations related to the following findings: (1) the chronical trends of logistics R&D, (2) focused fields of logistics R&D, (3) the relations among keywords, and (4) the characteristics of logistics R&D. Finally, we suggest policy implications to boost and diversify logistics R&D.