• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2454-2459
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• 2008

The objective of this paper is to find out the most effective injection angle for the purpose of deicing through SC/Tetra, a commonly used CFD software. Nowadays, vehicles are developed giving priority to an improved interior which emphasizes a pleasant environment and thermal comfort without decreasing the basic performance. Clear visibility is one of the most important phenomenon. The primary factors which affect the efficiency of deicing are 3D geometry of Defrost Nozzle, the inlet velocity and temperature of the flow and the injection angle. However in this paper, all these parameters are optimized by changing the injection angle. A wide range of injection angle from 5 degree to 50 degree have been considered for analysis. A very good defrosting performance has been achieved with 45 degree injection angle which can satisfy the condition of NHTSA.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.711-717
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• 2017

This paper proposes an improved sensorless control to estimate the rotor position of an interior permanent magnet synchronous motor. A phase-locked loop (PLL) is used to obtain the phase angle of the grid. The rotor position can be estimated using a PLL based on extended electromotive force (EEMF) because the EEMF contains information about the rotor position. The proposed method can reduce the burden of calculation. Therefore, the control period is decreased. The simulation and experimental results confirm the effectiveness and performance of the proposed method.

• Computers and Concrete
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• v.16 no.1
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• pp.67-97
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• 2015

This article presents a computing procedure developed to predict the torsional strength of axially restrained reinforced concrete beams. This computing procedure is based on a modification of the Variable Angle Truss Model to account for the influence of the longitudinal compressive stress state due to the axial restraint conditions provided by the connections of the beams to other structural elements. Theoretical predictions from the proposed model are compared with some experimental results available in the literature and also with some numerical results from a three-dimensional nonlinear finite element analysis. It is shown that the proposed computing procedure gives reliable predictions for the ultimate behaviour, namely the torsional strength, of axially restrained reinforced concrete beams under torsion.

• Journal of Magnetics
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• v.16 no.4
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• pp.391-397
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• 2011

An inductance measurement method for interior permanent magnet synchronous machine (IPMSM) is proposed in this paper. In this method, the motor is measured at standstill condition, and only a 3-phase voltage source, an oscilloscope and a DC voltage source are required. Depending on the deductive dq-axis voltage equations in the stationary frame of reference, the dq-axis inductances at different current magnitude and vector angle can be calculated by the measured 3-phase voltages and currents. And hence, the saturation and cross-magnetizing effect of the inductances are measurable. This paper introduces the principle equations, experiment setup, data processing, and results comparison on the concentrated-winding and distributed-winding IPMSMs.

• Structural Engineering and Mechanics
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• v.55 no.1
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• pp.1-27
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• 2015

This article presents a theoretical parametric analysis on the ultimate torsional behaviour of axially restrained reinforced concrete (RC) beams. This analysis is performed by using a computing procedure based on a modification of the Variable Angle Truss Model. This computing procedure was previously developed to account for the influence of the longitudinal compressive stress state due to the axial restraint conditions provided by the connections of the beams to other structural members. The presented parametric study aims to check the influence of some important variable studies, namely: torsional reinforcement ratio, compressive concrete strength and axial restraint level. From the results of this parametric study, nonlinear regression analyses are performed and some design charts are proposed. Such charts allow to correct the resistance torque of RC beams (rectangular sections with small height to width ratios) to account for the favorable influence of the axial restraint.

• Korean Institute of Interior Design Journal
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• v.15 no.4 s.57
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• pp.123-128
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• 2006

The purpose of the research is to estimate the amount of a color image reaction variation by changing areas in order to design the method to reduce an error about the color sample when it is applied in the real situation. The summary of the results acquired in this research is as followed. (1) With fixed observing distance of 1m, we observed that the value and chroma of each color object became higher as sight angle was increased as $2^{\circ},\;10^{\circ},\;and\;30^{\circ}$, even though the variation ratio was different. (2) With fixed sight angle of 10, we observed that the value and chroma of each color object becane higher as observing distance was changed from 1m to 3.3m, even though the variation ratio was different. (3) With same area, we observed that the values and chromas of each color object in the conditions of $1m-30^{\circ}\;and\;3.3m-10^{\circ}$ were almost same. (4) When the area became larger, the subjects tended to feel that colors were bright and clear with the increase of tone. In all the colors, the variation of a color reaction in chroma is higher than those in value. In future, we can observe the limit in applying to colors in the architecture by identifying the tendency of the color change according to the area change qualitatively.

• Korean Institute of Interior Design Journal
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• v.25 no.1
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• pp.151-162
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• 2016

Various mixed-use buildings have been developed in the process of resolving the issue of 'urban regeneration' in the modern city. In this urban regeneration process, the size of the mixed-use buildings and the level of their functional complexity have been increased. It requires a quantitative and systematic approach in order to analyze the internal circulation flow within the large-scale commercial mixed-use buildings. Circulation system and environmental factors, respectively, have been vital criteria for the effectiveness of a Wayfinding design within the mixed-use buildings. The circulation system in this paper consists of 1) the number of the incoming paths at each node, and 2) the angle of directional transition from the incoming paths at the node. The environmental factors include 1) color tone, 2) materials, 3) lighting, and 4) pattern of the interior design of the mixed-use buildings. In this paper, the author develops a method of investigating the influence of the correlation between the circulation system and the environmental factors on the design of Wayfinding on the view of the remodeled COEX MALL interior design.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.2
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• pp.55-62
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• 2012

In this paper we propose a control system to preserve the interior angle between back section and upper leg section to be larger than 90 degrees using a single limit switch. To design the control system we analyze the kinematics of actuation mechanisms for the back section and the upper leg section, and find out an optimal solution for the controller design. Using a prototype control system we perform experiments to test the controller performance, and show that the interior angle between the back section and the upper leg section is always preserved larger than 90 degree. From the experimental results, we show the proposed control system is feasible to keep the body posture stability.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.236-248
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• 2017

A direct stator flux vector control scheme in discrete-time domain is proposed in this paper for the interior permanent magnet synchronous motor (IPMSM) drive to remove the proportional-integral (PI) controller from the direct torque control (DTC) scheme applied to IPMSM and to obtain faster dynamic response and lower torque ripple output. The output of speed outer loop is used as the desired torque angle instead of the desired torque in the proposed scheme. The desired stator flux vector in dq coordinate is calculated with a given amplitude. The state-space equations in discrete-time for IPMSM are established, the actual stator flux vector is estimated in deadbeat manner by a full-order state observer, and then the closed-loop control is achieved by the pole placement. The stator flux error vector is utilized to calculate the reference stator voltage vector. Extracting the angle position and amplitude from the estimated stator flux vector and estimating the output torque are eliminated for the direct feedback control of the stator flux vector. The proposed scheme is comparatively investigated with a PI-SVM DTC scheme by experiment results. Experimental results show the feasibility and advantages of the proposed control scheme.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.64-71
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• 2015

This study aims to disclose the dynamics of Daniel Libeskind Museums by the principles of counterbalance. Balance as a dynamic concept is the settlement of instability and tension and to draw overall sense of balance by controlling new perception elements that may cope with the unbalance elements. This is based on balancing compensation and can be explained as a counterbalance. Daniel Libeskind, a representative architect of deconstructivism, creates dynamic space by using oblique lines on the plane. The study was carried out under the assumption that this space would be designed under the certain principles rather than the result of momentary feelings and the analysis was conducted by the counterpoint of music and counterbalance. As a result, Daniel Libeskind balances in a way of forming the mutual right angle by using oblique lines which cancel out the unbalance in plane composition or making the same angle based on vertical / horizontal axis. Counterbalance has been achieved in the section and elevation as well as plane and complex and diverse oblique lines were worked under the constant principle not accidental results. The axes of Daniel Libeskind's architecture have been known to follow contextualism with symbolism and historicity but it was found that a design technique considering counterbalance was used in the overall control.