• Journal of Institute of Control, Robotics and Systems
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• v.10 no.11
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• pp.1017-1021
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• 2004

In this paper, a cost-effective integrated 3D system for measuring and sizing foot is proposed. The proposed system employs two CCDs and a laser line projector which are capable of accurately measuring foot. The measurement is based upon the biologically motivated stereo vision principle providing ruggedness against minor system distortions. According to the tolerance, calibration between two different views are implicitly applied. Furthermore, the measurement system employs a measurement base, a frame grabber, a CCD moving cart, a stepping motor and computer. Analysis and design procedure is presented for the calculation of the 3D foot data and the proposed system. Experimental results on the proposed system would verify the concept and system operation.

• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.235-238
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• 1999

In a ceramic green body, some degree of nonuniformity in density always presents. These differences in green density will appear as nonuniform shrinkage after sintering takes place. For the complex ceramic bodies with various curves and angles, therefore, it is quite difficult to foresee the final dimensions precisely after sintering. This simulation study shows that, considering the sintering process as a thermal shrinkage phenomenon, the use of NASTRAN enables to predict the precise shape of a sintered body. Based on this result, 'the reverse engineering technique' has been developed that can unfold the exact dimensions of a green body to have the desired shape after sintering. This approach will provide a simple and useful tool for ceramic engineers to fabricate complicate bodies with tight dimensional tolerances.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.171-174
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• 2004

In order to improve the damage tolerance of the conventional laminated composites, three­dimensional fiber structures incorporated with stitching yams have been utilized in this study. From the newly developed process termed as TAPIS(TApe Placement Incorporated with Stitching), carbon/epoxy composites have been fabricated. Two-dimensional composites with the same stacking sequence as 3D counterparts have also been fabricated for the property comparison. To examine the damage resistance performance the low speed drop weight impact test has been adopted. For the assessment of damage after the impact loading, specimens were subjected to C-scan nondestructive inspection compression after impact(CAI) were also conducted to evaluate residual compressive strength. Although the damage area of 3D composites was greatly reduced$(30-40\%)$ compared with that of 2D composites, the CAI strength did not show drastic improvement.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.1018-1022
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• 2000

Enhancement of the accuracy of products and productivity are essential to survive in a global industrial competition. This trend requires tighter dimensional tolerance specifications. To actively cope with the rapid change of the workpiece material and cutter geometry, a general method that can predict and analyze the machined surface is needed. Surface generation model for the prediction of the topography of machined surfaces is developed based on cutting force model considering cutter deflection and runout. This paper presents the method that constructs the three-dimensional machined surface error following the movement of a cutter, irrespective of the variations of cutting conditions. In addition, the effects of the cutting forces and the kink shape on the machined surface are extensively investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.11
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• pp.2665-2671
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• 2000

Dimensional Synthesis, which is apart of kinematic synthesis, is to determine the dimensions of a mechanism of preconceived typer for a specified task and prescribed performance. In this paper, in an effort to provide designers with flexibility, a dimensional approximate synthesis method is presented for utilizing prescribed tolerance both the displacement and joint positions of a mechanism to be synthesized. For this, a constrained optimization problem is formulated with displacement parameters and joint positions as variables. The proposed method is applied to the synthesis of a 5-SS multi link suspension mechanism. The method discussed here, however, can be easily applied to any mechanism of which the kinematic constraint equations can be derived.

• Journal of Korean Society for Quality Management
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• v.22 no.4
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• pp.79-101
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• 1994

In modern manufacturing, a product consists of many components created by different processes. Variations in the individual component dimensions and in the processes may result in unacceptable final assemblies. Thus, engineers have increased pressure to properly set tolerance specifications for individual components and to control manufacturing processes. When a proper variation stack-up analysis is not performed for all of the components in a functional system, all component parts can be within specifications, but the final assembly may not be functional. Thus, in order to improve the performance of the final assembly, a proper variation stack-up analysis is essential for specifying dimensional tolerances and process control. This research provides a detailed case example of the use of variation stack-up analysis using a Monte Carlo simulation method to improve the defect rate of a complex process, which is the commutator brush track undercut process of an armature assembly of a small motor. Variations in individual component dimensions and process mean shifts cause high defect rate, Since some dimensional characteristics have non-normal distributions and the stack-up function is non-linear, the Monte Carlo simulation method is used.

• Transactions of Materials Processing
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• v.25 no.2
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• pp.130-135
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• 2016

Rolled products often have residual stresses or strip waves that are beyond the customer’s tolerance. To resolve this problem, skin-pass rolling is widely used during post-processing of such products. Because a short contact length compared to the strip width is a characteristic of skin-pass rolling, several numerical analyses have been previously conducted based on a two-dimensional approach. In the current study, a series of simulations was conducted using numerical analysis of three-dimensional elastic-plastic finite element method.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1995.11a
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• pp.163-172
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• 1995

In this paper, the bit-level 1-dimensionl systolic array for modular multiplication are designed. First of all, the parallel algorithms and data dependence graphs from Walter's Iwamura's methods based on Montgomery Algorithm for modular multiplication are derived and compared. Since Walter's method has the smaller computational index points in data dependence graph than Iwamura's, it is selected as the base algorithm. By the systematic procedure for systolic array design, four 1-dimensional systolic arrays ale obtained and then are evaluated by various criteria. Modifying the array derived from 〔0,1〕 projection direction by adding a control logic and serializing the communication paths of data A, optimal 1-dimensional systolic array is designed. It has constant I/O channels for modular expandable and is good for fault tolerance due to unidirectional paths. And so, it is suitable for RSA Cryptosystem which deals with the large size and many consecutive message blocks.

• Journal of Technologic Dentistry
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• v.41 no.1
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• pp.1-7
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• 2019

Purpose: The objectives of this study was to evaluate clinical adaptation of dental prostheses printed by 3 dimensional(3D) printing technology. Methods: Ten study models were prepared. Ten specimens of experimental group were printed by 3D printing(3DP group). As a control group, 10 specimens were fabricated by casting method on the same models. Marginal gaps of all specimens were measured to evaluate clinical adaptation. Marginal adaptations were measured using silicone replica technique and measured at 8 sites per specimen. Wilcoxon's signed-ranks test was used for statistical analysis(${\alpha}=0.05$). Results: Means of marginal adaptations were $95.1{\mu}m$ for 3DP group and $75.9{\mu}m$ for CAST group(p < 0.000). Conclusion : However, the mean of the 3DP group was within the clinical tolerance suggested by the previous researchers. Based on this, dental prosthesis fabricated by 3D printing technology is considered to be clinically acceptable.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.130-130
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• 2017

Sorghum bicolor is considered as copper-tolerant species. The present study was conducted to understand the copper tolerance mechanism in Sorghum seedling roots. Morphological and effects of Cu on other interacting ions were observed prominently in the roots when the plants were subjected to different concentrations (0, 50, and $100{\mu}M$) of $CuSO_4$. However, the morphological characteristics were reduced by Cu stress, and the most significant growth inhibition was observed in plants treated with the highest concentration of $Cu^{2+}$ ions ($100{\mu}M$). In the proteome analysis, high-throughput two-dimensional polyacrylamide gel electrophoresis coupled with MALDI-TOF-TOF mass spectrometry was performed to explore the molecular responses of Cu-induced sorghum seedling roots. In two-dimensional silver-stained gels, a total of 422 differentially expressed proteins (${\geq}1.5-fold$) were identified using Progenesis SameSpot software. A total of 21 protein spots (${\geq}1.5-fold$) from Cu-induced sorghum roots were analyzed by mass spectrometry. Of the 21 differentially expressed protein spots from Cu-induced sorghum roots, a total of 10 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of the most identified protein species from the roots that function in stress response and metabolism was significantly enhanced, while protein species involved in transcription and regulation were severely reduced. The results obtained from the present study may provide insights into the tolerance mechanism of seedling roots in Sorghum.