• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1998.04a
• /
• pp.432-437
• /
• 1998

This paper presents modal characteristics of bowl parts feeder featuring piezoelectric actuators. As wellknown, the piezoelectric materials develop an electric charge proportional to a mechanical stress and vice versa. This generic phenomenon allows us to use the piezoelectric materials as sensors and actuators. Using the actuating property, we can device effective bowl parts feeder. The parts feeder activated by the piezoceramic actuators provides a large degree of freedom of controlling excitation magnitude and frequency, and thus accurate and fast feeding of various parts. As a first phase to demonstrate these advantages, a finite clement model of the bowl parts feeder is constructed and analyzed using commercial software packages. In addition, the simulated modal characteristics are compared with the measured ones to validate the proposed model.

• Journal of the Korea Safety Management & Science
• /
• v.11 no.1
• /
• pp.93-101
• /
• 2009

The use of the gas turbine for power supply is increasing recently. Accordingly, the operation and maintenance cost of the gas turbine is gradually increasing and the various efforts to cut the cost are needed. For an operation and maintenance cost saving of the gas turbine, reductions of the new purchasing charge and the reproduction repair cost of the hot gas parts are required through more effective operation and life management methods for the hot gas parts. The hot gas parts are the main parts of the gas turbine and they are replaced with the periodic. In this research, efficient operation and life management methods for the hot gas parts were presented with the cases. The methods were analyzed and verified based on real data and the cases for improving a lifetime were utilized in the field.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.1 no.2
• /
• pp.103-116
• /
• 1993

Recently, engineering ceramics called as the 3 material have been concerned significantly with some excellent mechanical properties and many functions as new materials for high precision mechanical components and engineering parts for at large. Then, for designing engineering parts using engineering ceramics, bending strength value data with high reliability is more essential than any other mechanical properties. But, because of brittleness and structural characteristic, it is very hard to grind with conventional tools, and the generation of cracks and various defects of engineering ceramics parts during grinding machining process are serious problems. Thus, in present study, surface grinding experiments with various machining conditions using resin bond diamond wheels are carried out to obtain the most excellent guality of testpiece surface and optimum step of grinding process for the high efficient stock removal rate to save running time. As the results from grinding experiments and 3-points bending strength test of ground Al2O3 ceramics parts on Korean Standard, manufactured in our country and Japan, basic technology and know-how to develop the optimum grinding machining conditions and also high bending strength values with high reliability are obtained.

• Plant Resources
• /
• v.8 no.3
• /
• pp.188-193
• /
• 2005

In order to discern the possibility of functional food product or ingredient of a new medicine, the leaf parts and fruit parts of Prunus mume was partitioned with various solvents and their antioxidative activity was measured. When the antioxidative activity of MeOH extracts of leaf parts and fruit parts of Korea and China was compared, all of them showed the highest antioxidative activity in EtOAc fraction. In case of Korean Prunus mume leaf parts showed that quantity required for $RC_{50}$ to be $27.04{\mu}g$ in EtOAc fraction and in case of China Prunus mume leaf parts, it was $23.31\;{\mu}g$ which is similar to that of ${\alpha}$-tocopherol ($22.14\;{\mu}g$) and showed the highest activation. In case of Prunus mume fruit parts MeOH extract, Korean fruit showed $29.16\;{\mu}g$, and Chinese fruit showed $31.21\;{\mu}g$ in EtOAc fraction and thus Korean fruit extract showed a higher activity of antioxidant than the Chines fruit extract. When the antioxidative activity between the fruit parts and leaf parts of Prunus mume was compared, the leaf parts showed a higher antioxidative activity.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.2
• /
• pp.59-69
• /
• 2007

The main objective of this study is to suggest the new sizing system proper to the boys in the high school students by classifying their somatotype for the development of educational environment and uniform. The sample for this work was chosen from data which were collected and measured by Size Korea during two years $(2003\sim2004)$. In order to analyze feature of the somatotype of boys in the high school students, analysis was performed about 479 subjects on 37 body parts such as height (9 parts), width (5 parts), thickness (6 parts), circumference (7 parts), length (8 parts), body weight and $R\ddot{o}hrer$ Index. The result of this study can be utilized in various fields such as design of classroom, student uniforms, facilities and equipments for education at high school and university, etc.

• Journal of Ocean Engineering and Technology
• /
• v.27 no.5
• /
• pp.28-35
• /
• 2013

In this paper, a research on the composition of the nesting algorithm fitness function is carried out by performing various numerical experiments to inspect how it affects the scrap efficiency, allocation characteristics, and time consumption, targeting the nesting results of ship parts. This paper specifically concentrates on a method to minimize the scrap ratio and efficiently use the well-defined remnants of a raw plate after the nesting process for the remnant nesting. Therefore, experiments for various ship parts are carried out with the weighting factor method, one of the multi-objective optimum design methods. Using various weighting factor sets, the nesting results are evaluated in accordance with the above purposes and compared with each set for each ship part groups. Consequently, it is suggested that the nesting algorithm fitness function should be constructed differently depending on the characteristics of the parts and the needs of the users.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.17 no.4
• /
• pp.103-108
• /
• 2021

Knowledge graph is a technology that improves search results by using semantic information based on various resources. Therefore, due to these advantages, the knowledge graph is being defined as one of the core research technologies to provide AI-based services recently. However, in the case of the knowledge graph, since the form of knowledge collected from various service domains is defined as plain text, it is very important to be able to analyze the text and understand its meaning. Recently, various lexical dictionaries have been proposed together with the knowledge graph, but since most lexical dictionaries are defined in a language other than Korean, there is a problem in that the corresponding language dictionary cannot be used when providing a Korean knowledge service. To solve this problem, this paper proposes an ontology based on the parts of speech of Korean. The proposed ontology uses 9 parts of speech in Korean to enable the interpretation of words and their semantic meaning through a semantic connection between word class and word class. We also studied various scenarios to apply the proposed ontology to vehicle services.

• Advances in Traditional Medicine
• /
• v.9 no.4
• /
• pp.335-338
• /
• 2009

Aerial parts of Sida rhombifolia Linn. (Malvaceae) were extracted successively using various solvents and screened for various parameters of antiarthritic activity such as adjuvant-induced arthritis, motor performance, and histopathological study. The ethanol and the aqueous extracts showed potent activity; further these extracts were fractionated by using column chromatography. The fraction ET1 isolated from ethanol extract showed the most potent antiarthritic activity.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.409-417
• /
• 2021

The standardization of weapon system parts is one of the elements of parts management and is an important factor for reducing the cost of acquiring and maintaining a weapon system, enhancing its reliability, improving interoperability, alleviating parts obsolescence problems, improving logistics efficiency, and strengthening the military's combat readiness. This study examined how to manage parts of domestic R&D weapon systems, overseas imports weapon system parts, and various commercial parts from a standardization perspective, and to study parts management methods for standardizing parts in the future. This system was used to achieve systematic part standardization in a military weapon system. To this end, this study investigated what elements are used to standardize weapon system parts. The importance and weight of each element were calculated using the AHP (Analytic Hierarchy Process), one of the decision-making techniques, and the design stage standards using the part selection method were studied. Through this, the selection process of standard parts, which has been made according to the experience and subjective judgment of designers and personnel, was improved to propose a systematic and objective method of standardizing weapons parts.

• Journal of Sensor Science and Technology
• /
• v.26 no.1
• /
• pp.39-43
• /
• 2017

Development of vision system as a nondestructive evaluation system can be very useful in screening the defective mechanical parts before they are assembled into the final product. Since the tens of thousands of the mechanical parts are used in an automobile carefully inspecting the quality of the mechanical parts is very important to maximize the performance of the automobile. To sort out the defective mechanical parts before they are assembled, auto parts fabrication companies employ various inspection systems. Nondestructive evaluation systems are getting rapidly popular among various inspection systems. In this study, we have developed a vision system to inspect the inside of the brake caliper, a part that is used to compose a brake which is the most important to the safety of the drivers and the passengers. In a brake caliper, a piston is pushed against the brake disk by oil pressure, causing a friction to damp the rotation of the wheel. Inside the caliper, a groove is positioned to adopt an oil seal to prevent the oil leaks. Inspecting the groove with our vision system, we could examine the existence of the contaminants which are normally the residual tiny pieces from the machining process. We used a high resolution GigE camera, 360 degree lens to look in the inside view of the caliper at once, and a special illumination system in this vision system. We used the edge detection technique to successfully detect the contaminants which were in the form of small metal chips. Labview graphical program was used to process the digital data from the camera and to display the vision and the statistics of the contaminants. We were very successful in detecting the contaminants from the various size calipers. We think we are ready to employ this vision system to the caliper production factories.