• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1445-1451
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• 2011

Pneumatic valves are widely used parts that have the ability to control the air supplied to automation systems. However, if failure occurs in a pneumatic valve, it may affect the entire system and could lead to huge losses, depending on the characteristics of the system at the time of failure. Because of this significant risk and the level of consumer demand for reliability, there has been much study on ensuring the reliability of products by predicting valve lifetime distributions and degradation characteristics. In this paper, in order to determine the main factors useful for predicting the lifetime of a pneumatic valve, the scale parameter and $B_{10}$ life time value of the widely used plug-in-type pneumatic manifold valves were measured using complete observational data on the valve lifetimes. And also the property of life distribution has been distribution-suitabilityreviewed by correlation coefficients, the degradation characteristics of valve has been presented by the result of analysis through dynamic response time test and leakage test.

• Journal of Power System Engineering
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• v.17 no.1
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• pp.27-35
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• 2013

SCR (Selective Catalytic Reduction) on DPF (Diesel Particulate Filter) is a multi-functional after-treatment device which integrates soot filtration and DeNOx function into a single can. Because of its advantage in package and cost, the SCR on DPF is considered as a potential candidate for future application. It inherently employes wall flow type monolithic reactor so ash included in exhaust gas may deposit inside the inlet channel of this device. This study is intended to identify the impact of ash deposit on SCR reaction under wall flow type monolithic reactor. Simulation approach is used so relevant species transport equations for wall flow type monolith is derived. These equations can be solved together with momentum conservation equations and give solution for conversion performance. Both ash deposit and clean catalyst case are simulated and comparison of these two cases gives an insight for the impact of ash deposit on conversion performance. Ash deposit can be classified as ash layer and ash plug. and impact of ash deposit is described along with different morphology of ash deposit.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.535-538
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• 2022

For Plug & Play of IoT devices, we develop a module that recognizes the type of USB, which is a typical wired interface of IoT devices, through image recognition. In order to drive an IoT device, a driver for communication and device hardware is required. The wired interface for connecting to the IoT device is recognized by using the image obtained through the camera of smartphone shooting to recognize the corresponding communication interface. For USB, which is a most popular wired interface, types of USB are classified through artificial neural network-based machine learning. In order to secure sufficient data set of artificial neural networks, USB images are collected through the Internet, and additional image data sets are secured through image processing. In addition to the convolution neural networks, recognizers are implemented with various deep artificial neural networks, and their performance is compared and evaluated.

• Tuberculosis and Respiratory Diseases
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• v.76 no.6
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• pp.295-298
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• 2014

Pulmonary systemic arterialization to normal basal lung without sequestration is a rare congenital anomaly. In this rare abnormality, arterialization of the left lower lobe is the most common type. In general, surgical treatments have been performed. Recently, for reducing the complications and risks of surgery, embolization is mainly attempted by using coils. We report a case of 22-year-old male patient with a 10 mm anomalous arterial supply to his normal lung, which is being successfully treated by transcatheter embolization when using the Amplatzer Vascular Plug that has been adapted for the treatment of high-flows and large artery occlusions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.1
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• pp.42-47
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• 2016

This paper presents the development of a floating outboard type of compact water jet propulsion system. The planning case of the water jet system is developed by performing precision processing after manufacturing FRP (Fiber Reinforced Plastics) from plug mold casting. This system is composed of an intake, impeller, diffuser, reverse bucket, and main shaft. In addition, a rebuilt engine was applied through marine engineering. The water jet propulsion system performance was verified to discharge a maximum $0.29m^3/s$ of flow rate and 37 m/s of flow velocity in a test pool on land. A field test was performed by installing the water jet propulsion device on board a ship that was tested off the coast of Korea. The weight of the hull, engine, and other equipment was approximately 1.2 tons, and the sailing speed was a maximum 22 knots at 3,600 rpm.

• Convergence Security Journal
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• v.21 no.3
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• pp.3-11
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• 2021

Most of the internet security protocols rely on classical algorithms based on the mathematical complexity of the integer factorization problem, which becomes vulnerable to a quantum computer. Recent progresses of quantum computing technologies have highlighted the need for applying quantum key distribution (QKD) on existing network protocols. We report the development and integration of a plug & play QKD device with a commercial IPSec device by replacing the session keys used in IPSec protocol with the quantum ones. We expect that this work paves the way for enhancing security of the star-type networks by implementing QKD with the end-to-end IP communication.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.39-45
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• 2012

Today gasoline engines for vehicular application are not only faced with stringent emission regulation but also with increasing requirements to better fuel economy, while guaranteeing power density. The spray-guided type gasoline direct injection (GDI) engine has an advantage of improved thermal efficiency and lower harmful emissions. Centrally mounted high pressure injector and adjacent spark plug allow stable lean combustion due to the flexible mixture stratification. In the present study, the performance and emissions characteristics of developed spray-guided type GDI combustion system were evaluated at various excess air ratio conditions. The specific fuel consumption and nitrogen oxides ($NO_x$) emissions were reduced due to the achievement of stable lean combustion under flammability limit. Multiple injection strategy was not helpful to improve fuel consumption while further reduction of $NO_x$ emissions was possible.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.167-173
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• 2002

The VMSS(Virtual Makeup Simulation System) is a virtual simulation system which can apply makeup, hair style, accessory to user's own face image through internee connection. The simulation result can be stored to server side DB and also can be printed out on client side printer. It is implemented using Java so, clients don't need any other client program to run the VMSS except Web browser and Java Plug-in installed on browser. IIS (Internet Information Server) Web server of Window 2000 and MS-SQL 7 are used to develop the overall system. Commercial JDBC Driver Type 4 is used to connect the applet and DB. It suggests a new direction of Web-based contents service development and can be applied to many other areas.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.34-41
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• 2012

The study was conducted in a glasshouse to examine the possibility of producing paprika plug seedlings in a newly developed inert phenolic foam growing medium. Plug seedlings of 'Fascinato' paprika were grown in five media, Grodan rockwool (Grodan Co. Ltd., Denmark), UR rockwool (UR Co. Ltd., Korea), phenolic foam LC (Smithers Oasis Korea Co. Ltd., Korea), phenolic foam RC, and phenolic foam 3813-4 all in a pellet type. Seeds were germinated in a growth chamber ($25^{\circ}C$, 90% RH, dark) for 4-5 days and then seedlings were grown in a glasshouse with nutrient solution supplied by an overhead irrigation system. Seedling growths were measured 20 days after sowing. The medium pH was the highest in the Grodan rockwool, and medium EC was the highest in phenolic foam 3813-4, although no nutritional excess disorders were observed. Germination rates of paprika were higher than 90% in all the media. Plant height, stem diameter, T/R ratio, leaf area, and chlorophyll showed a similar to those in the rockwool medium. Number of leaves, length of the longest root and dry weights of shoot were not significantly different among treatments. Overall, phenolic foam LC and RC produced seedlings with a similar growth as the rockwool medium. The results obtained suggest that rockwool can be replaced with a new material such as phenolic foam in the commercial scale production of plug seedlings of 'Fascinato' paprika.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.134-142
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• 2019

This study was conducted to evaluate the growth characteristics of lettuce (Lactuca sativa L.) as affected by artificial light sources and different growing media in a closed-type plant production system (CPPS). The lettuce seeds were sown in the 128-cell plug tray filled with 5 different growing media such as urethane sponge (US), rock-wool (RW), Q-plug (QP), TP-S2 (TP) and PU-7B (PU). The germination rate of lettuce seeds was examined during 12 days after sowing. On the 13 days after sowing, the lettuce seedlings were transplanted in a CPPS with temperature $25{\pm}1^{\circ}C$ and nutrient solution (EC $2.0dS{\cdot}m^{-1}$, pH 6.5) using recirculating deep floating technique system. The light sources were set with FL (fluorescent lamps) and combined RB LEDs (red : blue = 7 : 3) with $150{\pm}10{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and a photoperiod of 14/10 hours (light/dark). The initial germination rate of lettuce was the highest in TP. The final germination and mean daily germination were the significantly highest in RW, QP and TP. The plant height, leaf length, leaf width, leaf area, and fresh and dry weights of shoot were the greatest in QP irradiated with RB LED. The number of leaves, fresh and dry weights of root and SPAD were the greatest in QP and TP irradiated with RB LED. The root length was the longest in TP irradiated with RB LED. Therefore, these results indicate that RB LED was effective for the growth of lettuce and it was also found that the QP and TP were effective for the germination and growth of lettuce in a CPPS. In addition, we confirmed the applicability of the newly developed growing medium TP for the lettuce production in a CPPS.