• Journal of the Korean Professional Engineers Association
• /
• v.21 no.2
• /
• pp.13-18
• /
• 1988

A Study for ethanol fermentation with immobilized yeast that is entrapped to Ca-alginate beads and batch system was carried out using molasses as substrate. The results are as follows. 1. The yield of alcohol fermentation is more efficacious then that of conventional fermentation process. The beads were used 15times and got a result of fermentation yield rate 89. 57％∼92.35％f, which is comparable with the rate of 86.3％ gained from the conventional fermentation process. 2. The concentration of Ca-alginate was 1∼5％ For long run use (2520 hours) it is necessary 2％ or more concentration of Ca-alginate. 3. The amount of the yeast cells for entrap to Ca-alginate beads was required 1.0g (indried material) or more for 200g Ca-alginate beads.

• Journal of the Korean Society for information Management
• /
• v.10 no.1
• /
• pp.97-124
• /
• 1993

This study was undertaken in order to develop practical automatic indexing techniques suitable for Korean natural language texts. It has taken a modest step toward this goal by developing an automatic syntactico-statistical indexing method and evaluating the method by comparing the resutls with manual indexing. For this experimental study, the Korean text database was constructed manually based on 300 abstracts covering business subject. The experimental results showed that the performance of the automatic syntactico-statistical indexing system was comparable to that of other studies which have compared automatic indexing with manual indexing.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.2 no.2
• /
• pp.107-112
• /
• 2009

Ultrasonographic examination for the rotator cuff disease is dynamic noninvasive study and the results is comparable to MRI on the behalf of recent development. It also can be used as a tool for guided injection and follow up study after rotator cuff repair. The development of equipment, learning curve and knowledge for the disease are the three most important factors for the critical role of the ultrasonography in the diagnosis and treatment of the rotator cuff disease.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.4
• /
• pp.271-287
• /
• 2001

This paper has been made to investigate the thermal performance characteristics for the several types of layered aluminum heat sinks with offset-strip fin. Heat sinks with different fin height, fin length, number of fin layer and slanted fin are prepared and tested for natural convection as well as forced convection. The experimental results for layered heat sink(LHS) are compared to those for advanced pin fin heat sink (PHS) so that the appropriate heat sink can be designed or chosen according to the heating conditions. The overall heat transfer performances for LHS are almost comparable to those of PHS under natural convection, and become 1.2∼1.5 times as high as those of PHS under forced convection situation. This study shows that fin height and number of fin layer re important parameters, which have a serious influence on thermal performance for layered heat sinks.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.05a
• /
• pp.186-189
• /
• 2004

Although magnesium has high potential for structural material due to the lightweight and high specific strength, the structural application has been limited by the low ductility at room temperature. The reason of the poor ductility is few activated slip systems of magnesium (HCP structure) during deformation. As temperature increases, however, additional non-basal slip systems are incorporated to exhibit higher ductility comparable to aluminum. In the present study, a series of tensile tests of Mg-Al alloy has been carried out to study deformation behavior with temperature variation. Analysis of load relaxation test results based on internal variable approach gave information about relationship between the micromechanical character and corresponding deformation behavior of magnesium. Especially, the material parameter, p representing dislocation permeability through barriers was altered from 0.1 to 0.15 as the non-basal slip systems were activated at high temperature.

• Journal of computational fluids engineering
• /
• v.6 no.3
• /
• pp.10-18
• /
• 2001

Genetic Algorithm(GA) is applied to aerodynamic shape optimization and demonstrated its merits in global searching ability and the independency of differentiability. However, applications of GA are limited due to slow convergence rate, premature termination, and high computing costs. The present aerodynamic designs such as wing shape optimizations using GA have seldom been applied because of high computing costs. This paper has two objects; improvement of the efficiency of GA and application of GA into aerodynamic shape optimization for 2D and 3D wings. The study indicates that GA can be applied to aerodynamic design and its performance is comparable to traditional design methods.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2006.04a
• /
• pp.437-444
• /
• 2006

Recently, as large structures become lighter and more flexible, the necessity of structural control for reducing excessive displacement and acceleration due to seismic excitation is increased. As a means to minimize seismic damages, various base isolation systems are adopted or considered for adoption. In this study, a base isolation system using Magneto-Sensitive(MS) rubbers is proposed and shown to effectively protect structures against earthquakes. The MS Rubber is a class of smart controllable materials whose mechanical properties change instantly by the application of a magnetic field To demonstrate the advantages of this approach, the MS Rubber isolation system is compared to Lead-Rubber Bearing(LRB) isolation systems and judged based on computed responses to several historical earthquakes. The MS Rubber isolation system is shown to achieve notable decreases in base drifts over comparable passive systems with no accompanying increase in base shears or in accelerations imparted to the superstructure.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2005.03a
• /
• pp.203-210
• /
• 2005

This paper summarizes full-scale test results on CFT column to flat plate connections subjected to gravity loading. CFT construction has gained wide acceptance in a relatively short time in domestic building practice due to its various structural and construction advantages. Constructing the floor as flat plate is often regarded as being essential for both cost savings and rapid construction. However, efficient details for CFT column to flat plate connections have not been proposed yet, and their development is urgently needed. Based on some strategies that include maximizing economical field construction, several connecting schemes were proposed and tested in this study. Test results showed the proposed connection details can exhibit strength and stiffness comparable to or greater than those of R/C flat plate counterpart.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.522-528
• /
• 2001

This study was conducted to determine the sound paths and transmitted sound level in house. An air-conditioner system was selected a typical sound source. The measured transmission loss data shows that the apertures have an significant effect on the transmitted noise and comparable with the existing theoretical data. Therefore the complex aperture was substitute to quantitative apertures approximately. An effective simulation method, ray tracing and mirror image source method, was employed in the prediction of transmitted sound level. The measured results were reflected on the simulated results.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1996.04a
• /
• pp.376-381
• /
• 1996

In this study, the quality contral of high strength reacy-mixed concrete with design compressive strength of 420 kgf/$\textrm{cm}^2$ placed at a tail building for a long period is statistically investigated. The amount of cast-in-place high strength concrete is by about $15000\textrm{m}^3$. The required average compressive striength is 500 kgf/$\textrm{cm}^2$ according to KS F 4009 with assumed coefficient of variation of 11%. Since there are many concrete members in this construction, fly ash is used to reduce the heat of hydration of concrete. As the results of this study, the average actual 28-day compressive strength is 498 kgf/$\textrm{cm}^2$ and the coefficient of variation is 6.7%. The placing speed is comparable to normal strength concrete, however, the pump pressure is higher than that of normal strength concrete.