• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.3
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• pp.63-70
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• 2016

The pyrotechnic separation devices are widely used in space systems and guided weapons during the launching and operations, however, they generate intensive pyroshock and fragments that can cause critical damages or the malfunction of electric devices onboard. There have been proposed many types of alternative devices to avoid pyro-induced problems since 1960's. A ball-type separation bolt is the one of alternative Pyrotechnic Mechanical Devices (PMD). In this study, the detail separation behavior of the ball-type separation bolt is analyzed using ANSYS AUTODYN. A simplified one-dimensional mathematical model, consisting of a combustion model and 5-stages of differential equation of motions, is also established to effectively describe the entire separation process.

• Convergence Security Journal
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• v.24 no.1
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• pp.27-34
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• 2024

Network separation is an important policy that Cyber Incident prevent cyber and protect data. Recently, the IT environment is changing in software development, such as remote work, using the cloud, and using open sources. Due to these changes, fintech companies' development productivity and efficiency are lowering due to network separation regulations, and the demand for easing network separation continued. The government revised the regulations electronic financial supervision(hereafter EFS) in response to needs for mitigation of network separation in the IT environment and fintech companies. Some amendments to the EFS, which took effect on 01/01/2023, mitigate network separation only for research and development purposes in cloud environments. If software developed in a cloud development environment is applied to an operating system through a distribution system the existing perimeter-based security model will not satisfaction the network separation conditions. In this Study, we would like to propose a way to maintain the DevOps system in a network separation environment by Using the zero trust security system.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.2
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• pp.211-219
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• 2016

To develop an ash separator for the solid fuel chemical looping combustion system, effects of operating variables such as solid injection nozzle velocity, diameter of solid injection nozzle, gap between solid injection line and vent line, vent line inside diameter, and solid intake height on solid separation rate and solid separation efficiency were measured and discussed using heavy and coarse particle and light and fine particles mixture as bed material in an acrylic fluidized bed apparatus. The solid separation rate increased as the solid injection nozzle velocity and the diameter of solid injection nozzle increased. However, the solid separation rate decreased as the gap between solid injection line and vent line, the vent line inside diameter, and the solid intake height increased. The solid separation efficiency was in inverse proportion to the solid separation rate. In this study, we could get high solid separation rate up to 2.39 kg/hr with 91.6% of solid separation efficiency.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.311-320
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• 2014

A magnetic separation study was conducted for a soil sampled from a landfill site where steel slag had been dumped for a long time. Heavy metal concentrating effect was evaluated by analyzing heavy metal content of magnetically separated soil and passed through soil. The effect was compared between soil after soil-washing process and original landfill soil and the effect was also tested between wet condition-magnetic separation and dry condition-magnetic separation. Separated ratio was relatively higher in non-soil washed sample. The water content has no significant effect on the separation rate. The concentrating effect of Fe, Pb, Cu, and Cd were 3.2, 2.1, 12.1, 2.5, 1.5 and 17.4, 7.0, 15.7, 9.6, 7.0 respectively for non-soil washed sample and soil washed sample. We can expect a bigger volume reduction effect from soil-washed samples. The volume reduction effect was obtained from the separation in dry condition. However, when the separation ratio is too high the volume reduction effect decreases. The magnetic separation leads to a volume reduction and concentration of heavy metals into a portion of soil in case of paramagnetic particles contained soil.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.5
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• pp.517-524
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• 2011

A vortex tube is a device that can separate small particles from a compressed gas or separate a compressed gas into hot and cold flows. We experimentally analyzed the energy-separation characteristics of a vortex tube with a diameter of 10 mm. We measured the energy-separation characteristics of the vortex tube for different inlet air pressures, orifice diameters, and tube lengths. The orifice diameter and inlet pressure are important for the vortex tube design and operation. The tube length has a small effect on the energy-separation performance. Maximum energy separation occurs for a vortex tube with Dc = 0.7 D and L = 16 D.

• Journal of Aerospace System Engineering
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• v.12 no.5
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• pp.69-75
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• 2018

In this study, we proposed a nylon wire cutting-type solar panel separation mechanism for CubeSat applications using spring-loaded pogo-pins, which has been widely used as temporary electrical interface between two separate electronics. The mechanism proposed in this study has great advantages of higher holding capability, ability to constrain along in-plane and out-of-plane directions of solar panels, simplicity in tightening of nylon wire and synchronous separation of multiple panels. In addition, the pogo-pins used for the proposed mechanism act as electrical power interface, separation status switch and separation spring. In this study, the functionality of the proposed mechanism was validated through the separation tests with various number of nylon wire windings.

• KSBB Journal
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• v.11 no.1
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• pp.46-51
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• 1996

Cell separation by means of continuous foam separation of Saccharomyes formosensis without additive was investigated. The yeast separation ratio was improved at low feed rates, high nitrogen rates, optimum pH and temperature for ethanol production, dilution of cultivation medium and addition of 0.5g/$\ell$ $CaCl_2$. Percentage of yeast removal and yeast separation ratio were more than 85 when continuous foam separation was operated in optimum condition..

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.8
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• pp.767-773
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• 2010

This paper describes development of a non-explosive separation device which can be equipped on small satellites. The spur geared micro DC motor, which has high reliability and advantage of price, is adopted as an actuator. The proposed separation device has resettability and it does not need extra jig to reload. In addition, the simple structure makes it easy to fabricate and assemble. To verify the performance of the proposed device, the response time tests, maximum preload tests and maximum shock level tests were performed. Also, through the vibration tests and thermal vacuum tests, feasibility of the proposed separation device was shown in launching and space environments. Therefore, we expect that the proposed separation device can replace the imported separation devices in near future.

• Journal of Animal Environmental Science
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• v.17 no.1
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• pp.33-38
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• 2011

Economic development involves increase in life expectancy as well as human health care. Consequently, demand for fish meal and fish oil is rapidly growing. In particular, Krill (Eupausia superba) oil product is in high demand due to its rich unsaturated-fatty acid, and thus stable supplies are necessary in the krill oil market. It is required for captured krills to be immediately frozen and stored during ship transport, since proteins of the krill are quickly denatured in natural temperature condition. However, the transportation cost has been sharply increased, which encourages researchers to involve in studies for development of efficient oil extraction process. In this study, a solid/liquid separation technique on boat for the krill oil was developed through triple separation tests using only a separator or using either brush or crusher prior to the separator. The separation tests revealed that the efficiency were 46.2, 60.2 and 60.4 % by the separator, combination with brush, and combination with crusher, respectively. In addition, it was found that byproduct, extracted cake, derived from the separation process could be used as a feed stuff. These results suggest that smashing using the brush or crusher prior to the separator is more efficient than using only the separator.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.409-416
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• 2022

This paper relates to the blind noise separation method of time-delayed convolutive mixed signals. Since the mixed model of acoustic signals in a closed space is multi-channel, a convolutive blind signal separation method is applied and time-delayed data samples of the two microphone input signals is used. For signal separation, the mixing coefficient is calculated using an inverse model rather than directly calculating the separation coefficient, and the coefficient update is performed by repeated calculations based on secondary statistical properties to estimate the speech signal. Many simulations were performed to verify the performance of the proposed blind signal separation. As a result of the simulation, noise separation using this method operates safely regardless of convolutive mixing, and PESQ is improved by 0.3 points compared to the general adaptive FIR filter structure.