• Proceedings of the Korean Fiber Society Conference
• /
• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
• /
• pp.100-100
• /
• 2003

An image processing algorithm has been developed in order to analyze the nanofiber web images obtained from a high magnification microscope. It has been known that precise pore detection on thick webs is extremely difficult mainly due to lack of light uniformity, difficulty of fine focusing and translucency of nanofiber web. The pore detection algorithm developed has been found to show excellent performance in characterizing the porous structure, thus being a promising tool for on-line quality control system under mass production. Since the images obtained from an optical microscope represent only web surface, a scale factor has been introduced to estimate the web structure as a whole. Resulting web structures have been compared to those by mercury porosimetry, especially in pore size distribution. It has been shown that those two structures have a strong correlation, indicating that scaling of a single layer web structure can be an effective way of estimating the structure of thick fiber webs.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 한국공작기계학회 2002년도 춘계학술대회 논문집
• /
• pp.245-250
• /
• 2002

A successful on-line monitoring system for conventional machining operations has the potential to reduce cost, guarantee consistency of product quality, improve productivity and provide a safer environment for the operator. In fee-shape machining, typical signs of tool problems such as vibration, noise, chip flow characteristics and visual signs are almost unnoticeable without the use of special equipment. These characteristics increase the importance of automatic monitoring in fine-shape machining; however, sensing and interpretation of signals are more complex. In addition, the shafts of the micro-tools break before the typical extensive cutting edge of the tool gets damaged. In this study, the existence of a relationship between the characteristics of the cutting force and tool usage was investigated, and tool breakage detection algorithm was developed and the fellowing results are obtained. In data analysis, didn't use a relative error compare which mainly used in established experiment and investigated tool breakage detection algorithm in time domain which can detect AE and cutting force signals more effective and accurate.

• Laser Solutions
• /
• 제16권3호
• /
• pp.22-26
• /
• 2013

Fiber laser welding was performed on SUS Materials metal bellows. The results can be summarized as follows: When we tried to change welding focus location. we get the best welding line when focus location placed 0mm. In product welding, We could make a satisfactory product in constant area by applying optimized conditions and show a table that is able to help producer easily to apply it to manufacturing. In comparison with existing TIG and plasma welding, welded bellows by fiber laser has faster processing speed, smaller thermal effect, very narrow welding area and fine surface.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 한국산업정보학회 1999년도 추계공동학술대회 논문집:21세기지식경영과 정보기술
• /
• pp.493-505
• /
• 1999

Zoom lens camera calibration is an important and difficult problem for two reason at least. First, the intrinsic parameters of such a camera change over time, it is difficult to calibration them on-line. Secondly, the pin-hole model for single lens system can not be applied directly to a zoom lens system. In this paper, We address some aspects of this problem.

• Nuclear Engineering and Technology
• /
• 제38권5호
• /
• pp.405-410
• /
• 2006

Microstructural features and their related mechanical property changes in the 309L cladding and the heat affected zone (HAZ) of SA508 cl.3 steel were investigated through the use of TEM, tensile and small punch (SP) tests. The specimens were irradiated at 563 K up to the neutron fluences of $5.79{\times}10^{19}n/cm^2$ (>1MeV). The microstructure of the clad was mainly composed of a fcc ${\gamma}-phase$, a low percentage of bcc ${\delta}-ferrite$, and a brittle ${\sigma}-phase$. Along the weld fusion line there formed a heavy carbide precipitation with a width of $20{\sim}40{\mu}m$, showing preferential cracking during plastic deformation. The yield stress and ductile-to-brittle transition temperature (DBTT) of the irradiated clads increased. The origin of the hardening and the shift of the DBTT are discussed in terms of the irradiation-produced defect clusters of a fine size and brittle ${\sigma}-phase$.

• Journal of Advanced Research in Ocean Engineering
• /
• 제2권1호
• /
• pp.40-47
• /
• 2016

This paper describes the design and performance of a hovering AUV constructed at KMOU (Korea Maritime and Ocean University). Before the field test, we analyzed the dynamic performance of the AUV using a simulation program made by Matlab & Simulink. Also, a PID controller was designed to control the thrusters. Using 4 thrusters (2 vertical and 2 horizontal), the AUV could be controlled using dynamic motion with 4-DOF. A simulation and field test were conducted with way-point tracking, maintaining the desired depth. To perform way-point tracking, the AUV can be fine-tuned to the desired heading angle through the LOS (Line Of Sight) method. This paper shows the results of simulation and field tests.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 한국정밀공학회 1995년도 추계학술대회 논문집
• /
• pp.1165-1168
• /
• 1995

This paper describes the evaluation of a robot based filament winding cell consisting of an industrial robot (ASEA IRB 6/2) and an in-house fabricated mandrel drive mechanism, both being coordinated by a personal computer. As in many manufacturing processes, tradeoffs exist between accuracy and speed. The accuracy versus speed relationships of the robotic winding cell were experimentally determined for discrete, fine and medium movement modes while traversing a segmented delivery eye path for a cylindrical mandrel in three configurations (in-line, offset and angled with respect to the axis of rotation). the results show that the robot winding cell is appropriate for very accurate winding of fibre strands if the mandrel axis is concentric with the mandrel drive axis and the discrete mode(i.e. low speed) of the robot is used.

• Journal of Sericultural and Entomological Science
• /
• 제16권2호
• /
• pp.111-117
• /
• 1974

The electron micrographs of the larval brain of the silkworm. Bembyx mori. show that median neurosecretory cell of diapause-egg producer may participate in the production of lipo-granules and that of non-diapause egg producer may do in the production of electron-translucent vesicles. It was found that ribosome-like particles of diapause-egg producer gradually developed into highly dense particles and came into line along the smooth-surfaced endoplasmic reticulum. They finally became lipo-granules.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
• /
• pp.2077-2078
• /
• 2006

This paper describes the development or a closed-loop Strapdown Attitude Reference System (SARS) algorithm integrated filtering estimator for determining attitude reference for railway and aviation system using fuzzy inference. The SARS consists of 3 single-axis rate gyms in conjunction with 2 single-axis accelerometers. For optimal values of fuzzy systems, we utilize on-line scheduling method for initial values and then use genetic algorithms for fine tuning. Implementation using experimental test data of unmanned aerial vehicle has been performed in order to verify the estimation. The proposed fuzzy inference based SARS demonstrate that more accurate performance can be achieved in comparison with conventional one. The estimation results were compared with the on-board vertical gyro as the reference standard.

• 보존과학연구
• /
• 통권21호
• /
• pp.207-231
• /
• 2000

Examples for application of cultural properties using Infrared Reflectography System as method of investigation on mural paintings and letters are given. This work is carried out according to asking of examination on inner layer paintings and letters in order to conserve the mural paintings discovered in the course of repairing ancient architectures. It is difficult to find the inner layer paintings and fine decorative line, but we can be observed by using Infrared Reflectography System and thus these results can be used as original rebuilding and drawings of mural paintings. Also building-repairing year, building participant though the investigation of letters written on the roof wood can be known.