• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.173-181
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• 2000

Depending upon the method of the surface generation and the quality of the boundary curves provided, the resulting surfaces may have global or local irregularities in many cases. Thus it would be necessary for the designer to evaluate the surface quality and to modify the surface. This capability is very important because the defect of the surface requires the rework of the dies that causes a big loss in cost and delivery time. To simulate the reflection line test in the actual production line, a faster generation algorithm is presented. Among., various surface interrogation methods using reflection lines, Blinn-Newell type of reflection mapping is applied to generate reflection lines on the trimmed NURBS surface. The generation of reflection lines is formulated as a surface-plane intersection problem, and solved by surface-contouring techniques. In addition, a modified reflection map is proposed to eliminate the discontinuity of reflection lines due to the configuration of the reflection map. A fast reflection line algorithm is developed utilizing an efficient traced contouring technique, and proved to be well suited for real-time quality-assessment task.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.2
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• pp.241-250
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• 2000

In this study, condensation heat transfer tests were conducted in flat aluminum multi-channel tubes using R-22. Two internal geometries were tested ; one with smooth inner surface and the other with micro-fins. Data are presented for the followin~ range of variables ; vapor quality($0.1{\sim}0.9$), mass flux($200{\sim}600kg/m^2s$) and heat flux($5{\sim}15kW/m^2$). The micro-fin tube showed higher heat transfer coefficients compared with those of the smooth tube. The difference increased as the vapor quality increased. Surface tension force acting on the micro-fin surface at the high vapor quality is believed to be responsible. Different from the trends of the smooth tube, where the heat transfer coefficient increased as the mass flux increased, the heat transfer coefficient of the micro-fin tube was independent of the mass flux at high vapor quality, which implies that the surface tension effect on the fin overwhelms the vapor shear effect at the high vapor quality. Present data(except those at low mass flux and high quality) were well correlated by equivalent Reynolds number, Existing correlations overpredicted the present data at high mass flux.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.379-383
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• 2015

Indicators of environmental conditions describe the state of the environment and the quantity and quality of natural resources. This study deduced the evaluation items to assess each sub-indicator for agricultural water quality and conducted the surveying using the Delphi method based on agricultural water quality experts. Considering its importance, environmental, state, and management indicators showed that state indicator such as COD concentration for surface water and $NO_3-N$ concentration for groundwater was ranked as first and followed by amount of fertilizer. Its indicators were correlated with state and environmental indicators in surface water and groundwater. The best management indicators were calculated to assess the agricultural surface water and ground water quality. The indicator could be used in established policies for management and conservation of water resources.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.1-5
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• 2019

This study has been focused on properties of surface technology for large diameter upper electrode using in high density plasma process as like semi-conductor manufacturing process. The experimental studies have been carried out to get mirror surface for upper electrode. For a formation of high surface quality upper electrode, single crystal silicon upper electrode has been mechanical and chemical machining worked. Mechanical machining work of the upper electrode is carried out with varying mesh type using diamond wheel. In case of chemical machining work, upper electrode surface roughness was observed to be strongly dependent upon the etchant. The different surface roughness characteristics were observed according to etchant. The machining result of the surface roughness and surface morphology have been analyzed by use of surface roughness tester, laser microscope and ICP-MS.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.3
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• pp.12-24
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• 1995

Various surface grinding experiments using resin bonded diamond abrasive wheels are carried out for tungsten carbide materials in order to minimize the damage on the ground surface and to purse the precise dimension compared to conventional grinding machine. When grinding quality is constant, theoretical grinding effect is changed according to the speed of workpiece. Accordingly, grinding forces, which are Fn, Ft, were analyzed for the machining processes of tungsten-carbide material to obtain optimum grinding conditions. Brief investigation is carried out to decrease the dressing efficiency of resinoid bonded diamond grinding wheel to grind tungsten-carbide. Truing is also carried out to provide a desired shape on a wheel or to correct a dulled profile. High quality in dimensional accuracy and surface are often required as a structural components, therefore 3-points bending test is carried out to check machining damage on the ground surface layer, which in one of sintered brittle material. From this experimental study, some useful machining data and information to determine proper machining condition for grinding of tungsten-carbide materials are obtained.

• Journal of Mechanical Science and Technology
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• v.15 no.2
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• pp.160-171
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• 2001

Depending upon the method of the surface generation and the quality of the designed boundary curves, the resulting surfaces may have global or local irregularities in many cases. Thus, it would be necessary for the designer to evaluate the surface quality and to modify the surface. This is very important because the defect of the surface causes the rework of the dies, increasing cost and delivery time significantly. To simulate the reflection line test in the actual production line, a faster algorithm for generating reflection lines is presented. In this paper, among various surface interrogation methods using reflection lines, Blinn-Newell type of reflection mapping is applied to generate the reflection lines on the trimmed NURBS surfaces. The derivation of reflection lines is formulated as a surface-plane intersection problem (Jung 1994) and is solved by surface-contouring techniques. Also, for eliminating the discontinuity of reflection lines due to the configuration of reflection map, a modified reflection map is proposed. An efficient traced contouring technique is utilized for the computational efficiency and proves to be well suited for the real-time quality-assessment task.

• Journal of the Korean institute of surface engineering
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• v.48 no.3
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• pp.93-99
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• 2015

This test focuses on the correlations between joining axial force at non-room temperature and at room temperature according to the surface treatment (Geomet, Dacro, Green Kote, Armore Galv.). The quality characteristics of the fastening axial force required by the KSB 2819 and EN14399-10 standards were discussed. Surface treatment was implemented to S10T and 10.9HRC sets of bolts under the same environmental factors. Development for the stabilization of the fastening axial force required by each standard should continually be enforced, and the fastening and storage in the field should be maintained at room temperature. Managing stabilization of torque enumerated data is required after application of surface treatment. It is concluded that, by conducting the test of applying surface treatment to effectively manage, each lot-specific rate of axial force at room temperature conditions should be maintained below the maximum 4.47%. The decline rate of axial force should be maintained under 2.15% maximum, and the standard deviation of the room temperature condition should be maintained below 0.5.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.404-408
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• 2006

Feasibility of surface plasmon resonance (SPR) method to evaluate soybean frying oil quality was evaluated. Free fatty acid value, p-anisidine value, conjugated dienoic acid content, conjugated trienoic acid content, peroxide value, iodine value, total polar compound (TPC), ratio of unsaturated fatty acid to saturated fatty acid, refractive index, dielectric constant, smoking point, and L, a, and b of Hunter color system were selected as parameters related to conventional evaluation of soybean frying oil quality. SPR scale mapped with conventional quality parameters well described free fatty acid value, conjugated dienoic acid content, dielectric constant, TPC, and b of Hunter color system, as shown by correlation and linear regression analyses.

• Journal of the Korean Institute of Navigation
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• v.12 no.3
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• pp.23-37
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• 1988

This paper deals with the method of determining the drag of hull surface which has any quality of roughness. The method consists mainly of the theoretical point of view, then the theory enables the drag coefficient to be calculated at full scale. The hydrodynamical roughness function of hull surface ${\triangle}U_+$, affected by the hull roughness are considered as to two cases, smooth surface and rough surface case separately. The inadequacy of a single parameter to define hull roughness is discussed and thus an as additional texture parameter is proposed.

• Journal of Korean Society for Quality Management
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• v.25 no.2
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• pp.102-111
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• 1997

In this paper I discuss a method of constructing the confidence region for the logistic response surface model. The construction involves a, pp.ication of a general fitting procedure because the log odds is linear in its parameters. Estimation of parameters of the logistic response surface model can be accomplished by maximum likelihood, although this requires iterative computational method. Using the asymptotic results, asymptotic covariance of the estimators can be obtained. This can be used in the construction of confidence regions for the parameters and for the logistic response surface model.