• Journal of the Microelectronics and Packaging Society
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• v.25 no.2
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• pp.41-48
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• 2018

The quantitative interfacial adhesion energy measurement method of copper redistribution layer and WPR dielectric interface were investigated using $90^{\circ}$ peel test, 4-point bending test, double cantilever beam (DCB) measurement for FOWLP Applications. Measured interfacial adhesion energy values of all three methods were higher than $5J/m^2$, which is considered as a minimum criterion for reliable Cu/low-k integration with CMP processes without delamination. Measured energy values increase with increasing phase angle, that is, in order of DCB, 4-point bending test, and $90^{\circ}$ peel test due to increasing roughness-related shielding and plastic energy dissipation effects, which match well interfacial fracture mechanics theory. Considering adhesion specimen preparation process, phase angle, measurement accuracy and bonding energy levels, both DCB and 4-point bending test methods are recommended for quantitative adhesion energy measurement of RDL interface depending on the real application situations.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.12
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• pp.140-145
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• 2004

In this study, the design and analysis of a butterfly valve disk was performed to minimize the rubbing between the disk and the seat at opening and closing. The butterfly valve has double eccentric structure and the contact surface between the disk and the seat is a conical surface. At the instant of opening and closing the valve by the rotation of disk, the positions of zero contact point are changed. Also, if the cone surface is cut in the perpendicular direction to the rotation axis of the valve, the contour of cutting section is hyperbolic. Therefore minimum distance between the origin of the eccentric axis and the hyperbolic curve goes to the position of zero contact point. In order to consider the interferences between the disk and the seat, the thermal-structure coupled field analysis was performed by ANSYS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1332-1344
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• 1996

This paper presents a pipelined floating point multiplier(FMUL) for superscalar microprocessors that conbines radix-16 recoding scheme based on signed-digit(SD) number system and new rouding and normalization scheme. The new rounding and normalization scheme enable the FMUL to compute sticky bit in parallel with multiple operation and elminate timing delay due to post-normalization. By expoliting SD radix-16 recoding scheme, we can achieves further reduction of silicon area and computation time. The FMUL can execute signle-precision or double-precision floating-point multiply operation through three-stage pipelined datapath and support IEEE standard 754. The algorithm andstructure of the designed multiplier have been successfully verified through Verilog HOL modeling and simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1345-1359
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• 1996

This paper presents a floating point arithmetic unit (FPAU) for supescalar microprocessor that executes fifteen operations such as addition, subtraction, data format converting, and compare operation using two pipelined arithmetic paths and new rounding and normalization scheme. By using two pipelined arithmetic paths, each aritchmetic operation can be assigned into appropriate arithmetic path which high speed operation is possible. The proposed normalization an rouding scheme enables the FPAU to execute roundig operation in parallel with normalization and to reduce timing delay of post-normalization. And by predicting leading one position of results using input operands, leading one detection(LOD) operation to normalize results in the conventional arithmetic unit can be eliminated. Because the FPAU can execuate fifteen single-precision or double-precision floating-point arithmetic operations through three-stage pipelined datapath and support IEEE standard 754, it has appropriate structure which can be ingegrated into superscalar microprocessor.

• ETRI Journal
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• v.19 no.3
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• pp.242-258
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• 1997

The Qualcomm code excited linear prediction (QCELP) speech coder was adopted to increase the capacity of the CDMA Mobile System (CMS). In this paper, we implemented the QCELP speech coding algorithm by using TMS320C50 fixed point DSP chip. Also the fixed point simulation was done with C language. The computation complexity of QCELP on TMS320C50 was 10k words and data memory was 4k words. In the normal call test on the CMS, where mobile to mobile call test was done in the bypass mode without double vocoding, mean opinion score for the speech quality was he Qualcomm code excited linear prediction (QCELP) speech quality was 3.11.

• Bulletin of the Korean Mathematical Society
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• v.49 no.1
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• pp.175-195
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• 2012

Representing planar Pythagorean hodograph (PH) curves by the complex roots of their hodographs, we standardize Farouki's double cubic method to become the undetermined junction point (UJP) method, and then prove the generic existence of solutions for general $C^1$ Hermite interpolation problems. We also extend the UJP method to solve $C^2$ Hermite interpolation problems with multiple PH cubics, and also prove the generic existence of solutions which consist of triple PH cubics with $C^1$ junction points. Further generalizing the UJP method, we go on to solve $C^2$ Hermite interpolation problems using two PH quintics with a $C^1$ junction point, and we also show the possibility of applying the modi e UJP method to $G^2[C^1]$ Hermite interpolation.

• Computers and Concrete
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• v.23 no.3
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• pp.171-188
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• 2019

This study proposed a new and efficient 2D damage-plasticity model within the framework of Isogeometric analysis (IGA) for the geometrically nonlinear damage analysis of concrete. Since concrete exhibits complicated material properties, two internal variables are introduced to measure the hardening/softening behavior of concrete in tension and compression, and an implicit gradient-enhanced formulation is adopted to restore the well-posedness of the boundary value problem. The numerical results calculated by the model is compared with the experimental data of three benchmark problems of plain concrete (three-point and four-point bending single-notched beams and four-point bending double-notched beam) to illustrate the geometrical flexibility, accuracy, and robustness of the proposed approach. In addition, the influence of the characteristic length on the numerical results of each problem is investigated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.49-52
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• 2004

Scalar multiplication is the back-bone operation in the elliptic curve cryptosystem. Quad-and-add algorithm replaced the traditional double-and-add algorithm to compute the scalar multiplication. In this paper, we introduce the method of utilizing the point quadruple scalar operation in the elliptic curve cryptosystem. Induced expressions were applied to real cryptosystem and proven at C language level. Point quadruple operation can be utilized to fast and efficient computation in the elliptic curve cryptosystem.

• The Korean Journal of Pain
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• v.14 no.2
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• pp.218-224
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• 2001

Background: Response to diagnostic blocks does not consistently predict the outcome of interventional facet denervation. We investigated the relationship between pain relief by the percutaneous radiofrequency denervation of the lumbar zygapophysial joints with the result of facet joint diagnostic local anesthetic injection in patients with back pain originating from the lumbar zygapophysial joint. Methods: There were 35 patients enrolled, with ranging in age from 25 to 76 years ($52.6{\pm}12.7$ years, mean ${\pm}$ SD). We studied 7 men (20%) and 28 women (80%). All patients underwent double diagnostic block of $L_{3/4}$, $L_{4/5}$ and $L_5-S_1$ facet joint with 0.5% bupivacaine. The 35 patients fell into the following group. (1) Group A (n = 16): those who felt clear relief (pain free with Likert scale) from the double diagnostic block (2) Group B (n = 19): 11 patients who were always equivocal in their response to the double diagnostic block and 8 patients who were either pain free or equivocal in their response to the double diagnostic block. All 11 patients were done the facet joint denervation. The effect on the pain was evaluated with 4 point Likert scale 1, 6 and 12 weeks after the procedure. We evaluated the relationship between the pain response to diagnostic block and the pain relief with facet joint denervation. Results: Significant correlation was observed between the response to diagnostic block and pain relief with facet denervation (P < 0.05). We found no correlation between the categories of spinal operation and pain response to facet denervation (P value > 0.05). Conclusions: A satisfactory result of lumbar facet joint denervation can be obtained in many patients, especillay in patients whose pain were relieved by the diagnostic double facet joint block. It may be said that facet joint denervation for mechanical low back pain using radiofrequency thermocoagulation is a safe, easy, and repeatable technique.

• Journal of Drive and Control
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• v.13 no.3
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• pp.24-31
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• 2016

The performance characteristics of a dynamic control system are evaluated according to the transient and steady-state responses. The transient performance is the controllability of the output for the tracking of the reference or the ability to reduce or reject the effects of unwanted disturbances; alternatively, the steady-state performance is represented by the magnitude of the control error at the steady state. As the effects of the two performances on each other are reciprocal, a controller design that shows a zero steady-state error for the ramp input is uncommon because of the challenge regarding the achievement of an acceptable transient response. This paper proposes a PI+double-integral controller for the elimination of the steady-state error for the ramp input while a sound transient performance is maintained. The control-gain design procedure is described by the second-order response for the step input and the response of the error dynamics for the ramp input. The PI+double-integral controller is designed for the first-order transfer function that is derived from a system identification with the open-loop experiment data of the dc-motor. The simple structure of the proposed controller enables the adoption of a low-end microcontroller for the implementation of a real-time control. The experiment results show that the control performance is as effective as that of the simulation analysis for the operating point of linear system; furthermore, the PI+double-integral controller can be conveniently applied to the control system, which is desirable for the improvement of the steady-state error.