• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.174-177
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• 2003

The automatic temperature control valve is used to control the flow rate of heating water in the large apartment complex and buildings. It is important to have simillar heating flow rate in the apartments, even though the apartment is top or bottom floors. To achieve those purposes, the automatic flow-temperature control valve was developed. The perfromance of this control valve is effected by the catridge shape and spring length. The flow capacity of this control valve is obtained with the different shape of catridges and with change of spring length.

• Journal of the Korean Society of Safety
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• v.13 no.2
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• pp.76-87
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• 1998

This study was carried out to investigate the effect of on temperature control from actuating method, recycling ratio and the position (top, middle and bottom) of set and controlled temperature within the reactor in adiabatic ebullated recycling condition, when the disturbance was occurred. Estimation of the solution were performed numerically using the finite difference method. It was assumed that the reaction is in constant with heat of reaction and the physical properties(density, heat capacity and viscosity, etc) of the reactants are same condition within the reactor.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.704-709
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• 1990

This study presents the structure and the gate control algorithm of KAMOBOT (KAIST Mobile Robot). The mobile robot has a six-legged, cylindrical configuration, each leg of which is equiped with a wheel at the bottom. The robot can go up and down stairs, go over obstacles, move along curvilinear paths and rotate around it's geometric center. Such maneuverability can be achieved by using only three electric motors.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.198-207
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• 1996

Electro sensitive traffic system can't consider passenger car unit, so, it causes start up delay time and passenger waiting time. In this paper, it antecedently creates optimal traffic cycle of passenger car unit at the bottom traffic intersection. But, sometimes it can make mistakes due to changes in car weight, car speed, and control of feed-back data. Moreover, to prevent spillback, it can adapt control even though upper traffic intersection has a different saturation rate, road length, road slope and road width.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.77-78
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• 2009

We report numerical simulations to investigate of the dependence of the on/off current ratio and channel charge distributions in silicon nanowire (SiNW) field-effect transistors (FETs) on the channel width and thicknesses. In order to investigate the transport behavior in devices with different channel geometries, we have performed detailed two-dimensional simulations of SiNWFETs and control FETs with a fixed channel length L of 10um, but varying the channel width W from 5nm to 5um, and thickness t from 10nm to 30nm. We have shown that $Q_{ON}/Q_{OFF}$ drastically decreases (from ${\sim}2.9{\times}10^4$ to ${\sim}9.8{\times}10^3$) as the channel thickness increases (from 10nm to 30nm). As a result of the simulation using a quantum model, even higher charge density in the bottom of SiNW channel was observed than that in the bottom of control channel.

• Steel and Composite Structures
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• v.28 no.3
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• pp.267-278
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• 2018

Structures may need retrofitting as a result of design and calculation errors, lack of proper implementation, post-construction change in use, damages due to accidental loads, corrosion and changes introduced in new editions of construction codes. Retrofitting helps to compensate weakness and increase the service life. Fiber Reinforced Polymer (FRP) is a modern material for retrofitting steel elements. This study aims to investigate the effect of deficiency location on the axial behavior of compressive elements of Circular Hollow Section (CHS) steel short columns. The deficiencies located vertically or horizontally at the middle or bottom of the element. A total of 43 control column and those with deficiencies were investigated in the ABAQUS software. Only 9 of them tested in the laboratory. The results indicated that the deficiencies had a significant effect on the increase in axial deformation, rupture in deficiency zone (local buckling), and decrease in ductility and bearing capacity. The damages of steel columns were responsible for resistance and stiffness drop at deficiency zone. Horizontal deficiency at the middle and vertical deficiency at the bottom of the steel columns were found to be the most critical. Using Carbon Fiber Reinforced Polymer (CFRP) as the most effective material in retrofitting the damaged columns, significantly helped the increase in resistance and rupture control around the deficiency zone.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.9
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• pp.1272-1280
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• 2001

An experimental study has been conducted to elucidate the resonance of natural convection in a side-heated square enclosure having a mechanically oscillating bottom wall. Under consideration is the impact of the imposed oscillating frequency, amplitude and the system Rayleigh number on the fluctuation of air temperatures. The experimental results show that the magnitude of the fluctuation of air temperature is substantially augmented at a specific forcing frequency of the oscillating bottom wall. The resonant frequency is increased with the increase of the Rayleigh number and it is little affected by the amplitude of the oscillating wall. It is also found that the resonant frequency is relevant to the Brunt- V$\"{a}$iS$\"{a}$l$\"{a}$ frequency which represents the stratification degree of the system.

• ETRI Journal
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• v.23 no.3
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• pp.111-120
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• 2001

For scalable multicast transport, one of the promising approaches is to employ a control tree known as acknowledgement (ACK) tree which can be used to convey information on reliability and session status from receivers to a root sender. The existing tree configuration has focused on a 'bottom-up' scheme in which ACK trees grow from leaf receivers toward a root sender. This paper proposes an alternative 'top-down' configuration where an ACK tree begins at the root sender and gradually expands by including non-tree nodes into the tree in a stepwise manner. The proposed scheme is simple and practical to implement along with multicast transport protocols. It is also employed as a tree configuration in the Enhanced Communications Transport Protocol, which has been standardized in the ITU-T and ISO/IEC JTC1. From experimental simulations, we see that the top-down scheme provides advantages over the existing bottom-up one in terms of the number of control messages required for tree configuration and the number of tree levels.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.728-731
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• 2009

We report numerical simulations to investigate of the dependendce of the on/off current ratio and channel charge distributions in silicon nanowire (SiNW) field-effect transistors (FETs) on the channel width and thicknesses. In order to investigate the transport behavior in devices with different channel geometries, we have performed detailed two-dimensional simulations of SiNWFETs and control FETs with a fixed channel length L of $10\;{\mu}m$, but varying the channel width W from 5 nm to $5\;{\mu}m$, and thickness t from 10 nm to 30 nm. We have show that $Q_{ON}/Q_{OFF}$ drastically decreases (from $^{\sim}2.9{\times}10^4$ to $^{\sim}9.8{\times}10^3$) as the channel thickness increases (from 10 nm to 30 nm). As a result of the simulation using a quantum model, even higher charge density in the bottom of SiNW channel was observed then in the bottom of control channel.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.825-832
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• 2008

The ice slurry maker which can produce the ice slurry well for the ice particle in-flowing condition was revised. We removed the stagnant region at the top of the ice slurry maker, and IPF 40% could be realized. The IPF controller with 6 mm diameter holes at the bottom was designed. But the IPF controller with only 6 mm diameter holes could not control IPF in a pipe. This is because the ice particles at ice slurry flow exist homogeneously not only at the upper part but also at the bottom part. We changed the hole size of IPF controller surface using fine meshes and then, IPF in a pipe was increased by 70% when the hole size was $80{\mu}m$ and less.