• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.17 no.5
• /
• pp.376-381
• /
• 2024

This study is about technology convergence analysis of patents related to artificial intelligence technology. After defining the IPC code 'section-class' of the patent literature as one technology, the relationship between core technologies was analyzed and visualized using the social network analysis(SNA). As a result of the analysis, the core technology of artificial intelligence-related patents is G06, which has a mutual relationship with a total of 52 other technologies. Technologies with many interconnections between technologies include G06, H02, G01, G08, H04, G10, G16, and A61. Additionally, the combination with the most correlation between technologies is G06⇄H04, with G06 being a more central technology than H04. The convergence of e-commerce-related business models(G06) and communication technologies(H04) is making an important contribution to creating innovative services and products. As a result, we can confirm that artificial intelligence technology is promoting innovation and convergence in various industries, and can contribute to understanding technological trends and the direction of technological convergence.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.5
• /
• pp.852-858
• /
• 2013

In numerical control (NC) machining, a machining error in equipment generally occurs for a variety of reasons. If there is a change in direction in the NC code, the characteristics of the automatic acceleration or deceleration function cause an overlap of each axis of the acceleration and deceleration zones, which in turn causes a shift in the actual processing path. Many studies have been conducted for error calibration of the edge as caused by automatic acceleration or deceleration in NC machining. This paper describes a geometric interpretation of the shape and processing characteristics of the operating NC device. The paper then describes a way to determine a feedrate that achieves the desired tolerance by using linear and parabolic profiles. Experiments were conducted by the validate equations using a three-axis NC machine. The results show that the machining errors were smaller than the machine resolution. The results also clearly demonstrate that the NC machine with the developed system can successfully predict machining errors induced with a change in direction.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.30 no.7 s.250
• /
• pp.707-714
• /
• 2006

A numerical analysis study has performed in terms of fluid dynamics to identify the wall thinning generated in the main feedwater isolation valve body of a nuclear power plant. To review the relations between flow characteristics and the wall thinning induced by flow accelerated corrosion (FAC), numerical analysis using FLUENT code and ultrasonic tests (UT) were performed. The local velocities according to the analysis results were compared with the distribution of the measured wall thickness by ultrasonic tests. The comparison results show that the local velocity in the x-direction had no correlation with the wall thinning but the local velocity in the y-direction and turbulence intensity had a great influence on that. These results provide a good match to those of the previous studies - locations colliding vertically against components undergo severe wall thinning. These results may be utilized to the design modification and the wall thinning management for main feedwater isolation valves for preventing the wall thinning degradation.

• International Journal of Fluid Machinery and Systems
• /
• v.2 no.1
• /
• pp.55-60
• /
• 2009

The present study investigated temperature and thermal stress distributions in a film cooling system with normal injection cooling flow. 3D-numerical simulations using the FEM commercial code ANSYS were conducted to calculate distributions of temperature and thermal stresses. In the simulations, the surface boundary conditions used the surface heat transfer coefficients and adiabatic wall temperature which were converted from the Sherwood numbers and impermeable wall effectiveness obtained from previous mass transfer experiments. As a result, the temperature gradients, in contrast to the adiabatic wall temperature, were generated by conduction between the hot and cold regions in the film cooling system. The gradient magnitudes were about 10~20K in the y-axis (spanwise) direction and about 50~60K in the x-axis (streamwise) direction. The high thermal stresses resulting from this temperature distribution appeared in the side regions of holes. These locations were similar to those of thermal cracks in actual gas turbines. Thus, this thermal analysis can apply to a thermal design of film cooling holes to prevent or reduce thermal stresses.

• Journal of the Society of Naval Architects of Korea
• /
• v.47 no.3
• /
• pp.430-437
• /
• 2010

In this paper, we develop a shape design optimization method for thermo-elastoplasticity problems that is applicable to the welding or thermal deformation problems of ship structures. Shell elements and a programming language APDL in a commercial finite element analysis code, ANSYS, are employed in the shape optimization. The point of developed method is to determine the design parameters such that the deformed shape after welding fits very well to a desired design. The geometric parameters of surfaces are selected as the design parameters. The modified method of feasible direction (MMFD) and finite difference sensitivity are used for the optimization algorithm. Two numerical examples demonstrate that the developed shape design method is applicable to existing hull structures and effective for the structural design of ships.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.1 s.244
• /
• pp.32-41
• /
• 2006

We analyzed the non-Newtonian and non-isothermal flow in the melt conveying zone in co-rotating and counter-rotating screw extruder system with the commercial code, STAR-CD, and compared the mixing performance with respect to screw speed and rotating direction. The viscosity of fluid was described by power-law model. The dynamics of mixing was studied numerically by tracking the motion of particles in a twin screw extruder system. The extent of mixing was characterized in terms of the residence time distribution and average strain. The results showed that high screw speed decreases the residence time but increases the shear rate. Therefore higher screw speed increases the strain and has better mixing performance. Counter-rotating screw extruder system and co-rotating screw extruder has the similar shear rate with the same screw speed in spite of different rotating direction. However, the counter-rotating screw has good mixing performance, which is resulted from longer residence time than that of co-rotating screw extruder.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.12
• /
• pp.127-132
• /
• 2004

It is very important to find out causes of strip pinching for the high quality of products and fer the stable operation of rolling system. We have examined the strip pinching from three points of view to find out the causes of strip pinching in rolling system: strip shape, rolling operation conditions, and behavior of strip. Wedge, off center, and difference of rolling force through CMD(Cross machine direction) are found to possibly provide major initial causes of strip pinching. Generally strip pinching occurred in the tail of strip. Thus, computer simulations by using a FEM code were also carried out to find out the initial mechanism of strip pinching depending upon the force and geometric boundary conditions at the time of strip tail rolling. The strong compression force effect due to the sudden release of strip tail from the work roll and non-uniform strip tail shape (ex. Fish tail) across the CMD were found to provide possible major causes of strip pinching.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.3
• /
• pp.453-461
• /
• 2020

In this study, we conducted technology monitoring to search for the current technology level and new technologies targeting the core technologies selected as "convergence technologies based on advanced ICT". This technology group, selected by the National Research Foundation(NRF) as one of the future-emerging technologies in 2018, consists of 'next-generation millimeter wave wireless communication technology', 'data-centric computing technology', and 'immersive media interface' that can be seen as important technologies in the fourth industrial revolution. It is possible to provide strategic research direction to the R&D-related stakeholders of countries or enterprises by providing information on newly emerged technologies through quantitative analysis based on patent data on these technologies. Therefore, in this study, we proposed a new technology for the convergence technologies based on advaned ICT group through patent data based on the newly emerged IPC code, and also suggested that it can suggest a strategic direction in planning R&D on related technologies.

• Proceedings of the KOSOMBE Conference
• /
• v.1990 no.05
• /
• pp.43-46
• /
• 1990

Modern society is prevailed a lot of allergies. So, the allergy test is very important. There are many kinds of allergy test. A doctor usually uses skin allergy test among many allergy tests. However, little standadization and objectivity of grading-standard has been established in the skin allergy test. A measurement of the reaction area has been a major objective to perform skin allergy test. Recently, a doctor's method is to measure the reaction area after drawing a line that represents the reaction area on the skin. But this method differs slightly from the real reaction area and individual doctor's measurement is different, because the edge of the reaction area is obscure. In this paper, we propose a algorithm which is able to detect vague edges using the fuzzy set. The algorithm that detects the line and curve is proposed first. Here, the maximum value is calculated by comparing the membership function of the line and curve seperately. We also encode the direction of the line and curve by using 8-direction code. Then, we calculate the reaction area by measuring the pixels which are inside the reaction area. And finally the Allergy grade is decided by grading-standard, and we accomplish faster, the 80re accurate and objective allergy grade decision.

• Journal of Korean Association for Spatial Structures
• /
• v.20 no.1
• /
• pp.49-59
• /
• 2020

This study investigates the wind pressure characteristics of elliptical plan retractable dome roof. Wind tunnel experiments were performed on spherical dome roofs with varying wall height-span ratios (0.1~0.5) and opening ratios (0%, 10%, 30% and 50%), similar to previous studies of cirular dome roofs. In previous study, wind pressure coefficients for open dome roofs have been proposed since there are no wind load criteria for open roofs. However, in the case of Eeliptical plan retractable dome roof, the wind pressure coefficient may be largely different due to the presence of the longitudinal direction and transverse direction. The analysis results leads to the exceeding of maximum and minimum wind pressure coefficients KBC2016 code.