• Korean Journal of Agricultural Science
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• v.39 no.2
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• pp.183-187
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• 2012

Specimens of five softwood species were heat-treated at three temperature levels of $170^{\circ}C$, $190^{\circ}C$ and $210^{\circ}C$. Their FSP's were measured by the volumetric Swelling Method. Within a species the FSP decreases as the temperature of heat treatment increases. The FSP's of the controls range from 21.0% to 32.5%, while those of the specimens heat-treated at $210^{\circ}C$ from 18.7% to 35.3%. There was no difference of basic density between the heat-treated and control specimens.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.19-25
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• 2005

Empirical experiments have been undertaken to investigate the effects of Intake Pulsating Flow on volumetric efficiency in a diesel engine. Waves occurs in the manifolds of engine owing to the periodic nature of the induction and exhaust processes caused by piston motion. During induction process, as waves travel both directions, they are reflected and interacted each other and pressure waves are transmitted through it. Hence, the flow become more complex and unsteady flow. These pressure waves act upon intake pulsating flow and affects on volumetric efficiency. In this paper the effects of change in length of induction pipes and wide range of engine speed on volumetric efficiency was examined and evaluated. It was found that volumetric efficiency was affected by intake pulsating flow with engine speed and the pipe length. The results obtained were considered by adopting a theory of wave action.

• Structural Engineering and Mechanics
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• v.26 no.2
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• pp.127-150
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• 2007

The objective of this paper is to develop a finite element procedure for predicting the compressive strength and ultimate axial strain of Carbon Fiber Reinforced Plastics (CFRP) confined circular concrete columns and to study the effective parameters of confinement efficiency for helping design of CFRP retrofit technology. The behavior of concrete confined with CFRP is studied using the nonlinear finite element method. In this paper, effects of column size, CFRP volumetric ratio and plain concrete strength are studied. The confined concrete nonlinear constitutive relation, concrete failure criterion and stiffness reduction methodology after concrete cracking or crushing are adopted. First, the finite element model is verified by comparing the numerical solutions of confined concrete with experimental results. Then the effects of column size, CFRP volumetric ratio and plain concrete strength on the peak strength and ductility of the confined concrete are considered. The results of parametric study indicate that the normalized column axial strength increases with increasing CFRP volumetric ratio, but without size effect for columns with the same CFRP volumetric ratio. As the same, the increase in column ductility depends on CFRP volumetric ratio but without size effect for columns with the same CFRP volumetric ratio.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.515-520
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• 2016

Volumetric image system has many applications recently in education, 3D movie, medical images but these applications have several problems that need to be overcome. Volumetric display may process a amount of visual data and design the high efficient vision system for realtime display. In case of stereo system for volumetric display motion vectors, disparity vectors from the stereoscopic sequences and residual images with the reference images has been transmitted, and the stereoscopic sequences have been reconstructed at the receiver for volumetric display. So central issue for the design of efficient volumetric image system lies in selecting an appropriate stereo matching and robust vision system. In this paper, we proposed high efficient vision system, which design vision stage with rotating and moving horizontally, and match the successive stereo image efficiently. In experimental results with volumetric image system, the proposed method represents high efficiency with minimizing error and low computational load for volumetric display.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.81-82
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.429-430
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• 2012

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.223-228
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• 2011

The volumetric solar receiver is a key element of solar power plants using air. The solar flux distribution inside the receiver should be a priori known for its heat transfer modeling. Previous works have not considered characteristics of the solar flux although they change with radiative properties of receiver materials and receiver geometries. A numerical method, which is based on the Monte Carlo ray-tracing method, was developed in the current work. The solar flux distributions inside multi-channeled volumetric solar receivers were calculated when light is concentrated at the KIER solar furnace. It turned out that 99 percentage of the concentrated solar energy is absorbed within 15 mm charmel length for the charmel radius smaller than 1.5 mm. If the concentrated light is assumed to be diffuse, the absorbed solar energy at the charmel entrance region is overpredicted while the light penetrates more deeply into the charmel. The developed method will help understand the solar flux when only a part of concentrated light is of interest. Furthermore, if the presented results are applied for heat transfer modeling of multi-channeled volumetric solar receivers, one could examine effects of receiver charmel properties and shape on air temperature profiles.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.3
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• pp.39-47
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• 1995

This paper suggests generalize mathematica mode for the benefit of volumetric error analysis of a multi-axis machine tool machining a sculptured surfaces. The volumetric error, in this paper, is defined as a three dimensional error at the cutting point, which is caused by the geometric errors and the kinematic errors of each axis and alignment errors of the cutting tool. The actual cutting position is analyzed based on the form shaping model including a geometric error of the moving carriage, where a form shaping model is derived from the homogeneous transformation matrix. Then the volumetric error is obtained by calculating the position difference between the actual cutting position and the ideal one calculated from a Nonuniform Rational B-Spline named as NURES. The simulation study shows the effectiveness for predicting the behavior of machining error and for the method of error compensation.

• Journal of the Korean Society of Safety
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• v.8 no.3
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• pp.3-12
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• 1993

In reciprocating internal combustion engine, engine performance Is greatly affected by volumetric efficiency. For gas flow, the dynamic effects caused by the pressure pulsation have influence on the volumetric efficiency and correlate to the configuration and pipe length of intake-exhaust system. In this study, the analytic investigation of the unstudy flow In exhaust pipe has been carried out by using the method of characteristics to predict volumetric efficiency. In conculusion, it is possible to take account of the exhaust pipe tuning effect in predicting the engine performance, by the analytic solution of the unsteady flow in the pipes, and comparision of prediction with experimental datas show a good agreement on the pressure varision in the exhaust pipe which has Influence on the volumetric efficiency and performance of engine.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.12
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• pp.2899-2908
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• 2000

Methodology of volumetric error identification is presented to improve the accuracy of NC machine tools by using a reference artifact and a touch trigger probe. Homogeneous transformation matrix and kinematic chain are used for modeling the geometric and thermal errors of a three-axis vertical machining center. The reference artifact is designed and fabricated to identify the model parameters by machine tool metrology. Parameters in the error model are able to be identified and updated by direct measurement of the reference artifact on the machine tool under the actual conditions which include the thermal interactions of error sources. The proposed method can speed up and simplify volumetric error identification processes.