• Journal of Ocean Engineering and Technology
• /
• v.24 no.4
• /
• pp.72-77
• /
• 2010

This paper presents a method for measuring the shaft power of a marine main engine. Usually, in traditional systems for measuring shaft power, a strain gauge is used even though it has several disadvantages. First, it is difficult to set up the strain gauge on the shaft and acquire the correct signal for analysis. Second, it is very expensive and complicated. For these reasons, we investigated alternative approaches for measuring shaft power and proposed a new method that uses a vision-based measurement system. For this study, templates for image processing and CCD cameras were installed at the both ends of the shaft. Then, in order for the cameras to capture the images synchronously, we used a trigger mark and a optical sensor. The position of each template between the first and the second camera images were compared to calculate the torsion angle. The proposed measurement system can be installed more easily than traditional measurement systems and is suitable for any shaft because it does not contact the shaft. With this approach, it is possible to measure the shaft power while a ship is operating.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.55-58
• /
• 2002

Parallel finite element code has been recently developed for the analysis of the incompressible Wavier-Stokes equations using domain decomposition method. Metis and MPI libraries are used for the domain partitioning of an unstructured mesh and the data communication between sub-domains, respectively. For unsteady computation of the incompressible Navier-Stokes equations, 4-step splitting method is combined with P1P1 finite element formulation. Smagorinsky and dynamic model are implemented for the simulation of turbulent flows. For the validation performance-estimation of the developed parallel code, three-dimensional Laplace equation has been solved. It has been found that the speed-up of 40 has been obtained from the present parallel code fir the bench mark problem. Lastly, the turbulent flows around the MIRA model and Tiburon model have been solved using 32 processors on IBM SMP cluster and unstructured mesh. The computed drag coefficient agrees better with the existing experiment as the mesh resolution of the region increases, where the variation of pressure is severe.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.7
• /
• pp.961-969
• /
• 2004

Most manufacturing companies are trying to develop a competitive product by increasing the quality, shortening time to market and reducing the cost of a product. Collaborators related to the development of a new product want to confirm geometric forms and dimensions during the design process, as well as to verify dimensional errors of a product during the fabrication process. Objective of this paper is the development of a collaborative design and dimension verification system on the Internet. STEP files obtained from the design process are used for the design and dimension verification. Functions of the design and dimension verification modules are constructed over the ActiveX control using the visual C/sup ++/ and OpenGL. By using mark up functions over the Internet, collaborators check geometries, interferences, dimensional errors, human factors and form errors, as well as share their design ideas and opinions with XML rapidly and remotely. The usefulness of the developed system is confirmed through case studies.

• Journal of Korea Spatial Information System Society
• /
• v.9 no.2
• /
• pp.35-53
• /
• 2007

GML is a mark-up language which is suggested by OGC(Open GIS Consortium) for use of encoding standard concerning with storing and transferring Geographic information. For general spatial network database, researches supporting GML documents can be classified into three categories : parsing, storing, and retrieval of GML documents. Among them, the 'Storing of GML document' is essential for efficient GML document retrieval. However, There is little research on schema for storing GML documents. In addition, the existing schema for storing XML documents can't be used for GML documents due to geographic information. Therefore, In this paper, we propose efficient schema for storing GML documents In addition, we do performance evaluation of the GML schema.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.168-169
• /
• 2000

We have tried to enhance the density of the near-field optical memory and to improve the recording/readout speed. The current optical memory has the limitation in both density and speed. This barrier due to the far-field nature can be overcome by the use of the near-field$^{(1)}$ . The optical data storage density can be increased by reducing the size of the nanometric aperture where the near-field is obtained. To fabricate the aperture in precise dimension, we applied the orientation-dependent / anisotropic etching property of crystal Si often employed in the field of MEMS$^{(2)}$ . And so we fabricated the 10$\times$10 aperture array. This array will be also the indispensable part for speeding up. One will see the possibility of the multi-tracking pickup in the phase changing type memory through this array$^{(3)}$ . This aperture array will be expected to write the bit-mark whose size is about 100nm. We will show the recent result obtained. (omitted)

• Radiation Oncology Journal
• /
• v.34 no.3
• /
• pp.209-215
• /
• 2016

Purpose: We sought to determine if organ preservation (OP) with neoadjuvant chemoradiation (CRT) was feasible in patients with sinonasal cancer determined to require exenteration. Materials and Methods: Twenty patients were determined to require exenteration for definitive treatment from 2005 to 2014. Fourteen patients underwent OP and 6 patients received exenteration with adjuvant CRT. Exenteration free survival (EFS), locoregional control (LRC), progression-free survival (PFS), and overall survival (OS) were estimated. Results: Five patients (36%) receiving OP had complete disease response at time of surgery. With a median follow-up of 18.8 months, EFS was 62% at 2 years for patients undergoing OP. At 2 years, there were no significant differences in LRC, PFS or OS (all all p > 0.050) between the groups. Less grade 3 or greater toxicity was seen in patients undergoing OP (p = 0.003). Visual function was preserved in all patients undergoing OP. Conclusion: For patients with sinonasal cancer, OP may avoid exenteration, offering similar disease control and improved toxicity.

• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.2
• /
• pp.146-151
• /
• 2016

This study concentrates on the design of floater for 15kW-class wave energy converter that extracts the ocean energy by oscillating vertically along the wave motion. The floater connects to a arm structure that connects to a hydraulic cylinder, which drives a hydraulic generator. The study mainly focuses on the structural analysis of the floater. Previous studies have been conducted using a miniature model; however, this study focuses on the size selection of the floater for a full scale model. Static structural analysis is conducted using fine numerical grids. Due to the complexity of the whole model, it is analyzed as a separate component. There are several load cases for each floater size, and they are analyzed thoroughly for stress (von-mises, shear, and normal) and deformation. The initial design was conducted by scaling up from the miniature model of the previous study, and the final design has been redesigned by changing the thickness and internal support structure shape.

• Journal of Korea Multimedia Society
• /
• v.11 no.8
• /
• pp.1169-1178
• /
• 2008

Most of information in Web2.0 is constructed by users and can be classified by tags which are also constructed and added by users. However, as we known, referring by the related works such as automatic tagging techniques and tag cloud's construction techniques, the research to be classified information and resources by tags effectively is to be given users which is still up to the mark. In this paper, we propose and implement a clustering system that does mapping each other according to relationships of the resource's tags collected from Web and then makes the mapping result into clusters to retrieve images. Tn addition, we analyze our system's efficiency by comparing our proposed system's image retrieval result with the image retrieval results searched by Flickr website.

• International Commerce and Information Review
• /
• v.12 no.4
• /
• pp.3-24
• /
• 2010

This study aims to identify the determinants on the implementation level of e-Trade of Chinese exporters in Shandong Province, China. From the review of previous studies, a research model and six hypotheses were set up and tested by the multiple regression analysis with total 127 effective survey data. Among the company characteristics, the company size was statistically significant to the utilization range and the utilization level. But unlike former studies in Korea, the utilization range showed the (-) mark. On the other hand, the innovative attitude of CEO didn't show statistical significance to both the utilization range and the utilization level. Among the information characteristics, the IT infrastructure was not statistically significant to both the utilization range and the utilization level. On the other hand, the education and training of technical personnel didn't have a significant effect on the utilization range, but it had a statistically significant effect on the utilization level. Among the external environment, the intensity of competition had a statistically significant effect on both the utilization range and the utilization level. In summary, the implementation level of e-Trade of Chinese exporters in Shandong Province, China is still behind that of Korea. But the fact that the small and medium-sized Chinese exporters are using Internet more actively than large companies suggests some implications for those of Korea.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2012.11a
• /
• pp.256-258
• /
• 2012

최근 LED를 이용한 IT 기술이 많은 관심을 받고 있으며, 특히 무인시설물에서는 효율적으로 LED를 관리해야하기 때문에 통신 및 조명 제어기술에 대한 연구가 활발히 진행 중에 있다. 그러나 LED 특성상 FOI(Filed of Illumination)의 제약이 따르기 때문에 서비스의 범위와 커버리지가 제한적이라는 한계를 가지며, LED 제어의 경우 최근 스마트단말을 이용한 기술이 많이 보급되고 있으나 수많은 스마트단말의 OS 플랫폼에 종속적으로 프로그램을해야만 하는 번거로움이 있기 때문에 개발 비용적인 측면에서도 매우 비효율적이다. 따라서 본 논문에서는 LED 기반 IT기술의 서비스 이용범위를 유연하게 넓힐 수 있는 LED 지향각의 원격제어 기술을 제안하고, 단말환경에 독립적으로 효과적인 LED제어를 가능하게 하는 차세대 웹표준인 HTML5(Hypertext Mark-up Language 5)기반의 시스템을 제안하였으며, 제안 기술의 핵심 프로그램을 제시하고 시뮬레이션을 수행함으로써 유용성을 입증하였다.