• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.140.4-140
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• 2001

This paper presents the duplex controller operated as master slave for Self Excited Static Type excitation system and the results of operation for duplex digital excitation system. Software is made up duplex multi-tasking control algorithm which is based on VxWorks(real-time OS), preprocessing algorithm for input-output signal, BSP & Device Driver for interfacing hardware and software, and OIS(Operator Interface Station) program, HMI S/W. Master controller and slave controller intercommunicate dominant data to minimize bump when controller switchover from master to slave occurs. Communication between master controller and slave controller is duplicated and communication between OIS and controller is duplicated. Hardware is made up VMEBUS based controller which is designed with PPC & I/O board ...

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.3
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• pp.189-195
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• 2004

A 10 Gb/s limiting amplifier IC with the emitter area of $1.5{\times}10{\mu}m^2$ for optical transmission system was designed and fabricated with a AIGaAs/GaAs HBTs technology. In this stud)', we evaluated fine pitch bump using WL-CSP (Wafer Level-Chip Scale Packaging) instead of conventional wire bonding for interconnection. For this we developed WL-CSP process and formed fine pitch solder bump with the $40{\mu}m$ diameter and $100{\mu}m$ pitch on bonding pad. To study the effect of WL-CSP, electrical performance was measured and analyzed in wafer and package module using WL-CSP. In a package module, clear and wide eye diagram openings were observed and the riselfall times were about 100ps, and the output" oltage swing was limited to $600mV_{p-p}$ with input voltage ranging from 50 to 500m V. The Small signal gains in wafer and package module were 15.56dB and 14.99dB respectively. It was found that the difference of small signal gain in wafer and package module was less then 0.57dB up to 10GHz and the characteristics of return loss was improved by 5dB in package module. This is due to the short interconnection length by WL-CSP. So, WL-CSP process can be used for millimeter wave GaAs MMIC with the fine pitch pad.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.1 s.34
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• pp.9-16
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• 2005

This paper presents the development of new anisotropic conductive adhesives with enhanced thermal conductivity for the wide use of adhesive flip chip technology with improved reliability under high current density condition. The continuing downscaling of structural profiles and increase in inter-connection density in flip chip packaging using ACAs has given rise to reliability problem under high current density. In detail, as the bump size is reduced, the current density through bump is also increased. This increased current density also causes new failure mechanism such as interface degradation due to inter-metallic compound formation and adhesive swelling due to high current stressing, especially in high current density interconnection, in which high junction temperature enhances such failure mechanism. Therefore, it is necessary for the ACA to become thermal transfer medium to improve the lifetime of ACA flip chip joint under high current stressing condition. We developed thermally conductive ACA of 0.63 W/m$\cdot$K thermal conductivity using the formulation incorporating $5 {\mu}m$ Ni and $0.2{\mu}m$ SiC-filled epoxy-bated binder system to achieve acceptable viscosity, curing property, and other thermo-mechanical properties such as low CTE and high modulus. The current carrying capability of ACA flip chip joints was improved up to 6.7 A by use of thermally conductive ACA compared to conventional ACA. Electrical reliability of thermally conductive ACA flip chip joint under current stressing condition was also improved showing stable electrical conductivity of flip chip joints. The high current carrying capability and improved electrical reliability of thermally conductive ACA flip chip joint under current stressing test is mainly due to the effective heat dissipation by thermally conductive adhesive around Au stud bumps/ACA/PCB pads structure.

• Journal of the Microelectronics and Packaging Society
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• v.17 no.3
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• pp.65-69
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• 2010

In this study, we investigated the effects of UBM(Under Bump Metallization) and solder composition on the drop impact reliability of wafer level packaging. Fan-in type WLP chips were prepared with different solder ball composition (Sn3.0Ag0.5Cu, and Sn1.0Ag0.5Cu) and UBM (Cu 10 ${\mu}m$, Cu 5 ${\mu}m$\Ni 3 ${\mu}m$). Drop test was performed up to 200 cycles with 1500G acceleration according to JESD22-B111. Cu\Ni UBM showed better drop performance than Cu UBM, which could be attributed to suppression of IMC formation by Ni diffusion barrier. SAC105 was slightly better than SAC305 in terms of MTTF. Drop failure occurred at board side for Cu UBM and chip side for Cu\Ni UBM, independent of solder composition. Corner and center chip position on the board were found to have the shortest drop lifetime due to stress waves generated from impact.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.266-270
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• 2011

The advancement of technology enables smart phones or handheld devices to render complex 3D graphics. However, the processing power and memory of smart phones remain very limited to render high polygon and details 3D models especially on games which requires animation, physic engine, or augmented reality. In this paper, several techniques will be introduced to speed up the computation and reducing the number of vertices of the 3D meshes without losing much detail.

• Korean Journal of Veterinary Research
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• v.62 no.4
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• pp.28.1-28.4
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• 2022

Splenic myelolipoma is a rare tumor in dogs with an unclear origin. A male 13-year-old Schnauzer dog was presented because of a bump on the left side of the abdomen. Clinical examination and abdominal ultrasound revealed a mass in the spleen. A total splenectomy was carried out, and histopathology revealed a splenic myelolipoma. Before surgery, the patient showed high serum alanine aminotransferase levels, which returned to normal eight months after the resection. Unfortunately, the postoperative follow-up showed increased serum cholesterol and triglyceride levels, suggesting liver compromise. This is the first report of a splenic myelolipoma in Colombia.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.146-150
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• 2001

Microwave model and high-frequency measurement of the ACF flip-chip interconnection was investigated using a microwave network analysis. S-parameters of on-chip and substrate were separately measured in the frequency range of 200 MHz to 20 GHz using a microwave network analyzer HP8510 and cascade probe. And the cascade transmission matrix conversion was performed. The same measurements and conversion techniques were conducted on the assembled test chip and substrate at the same frequency range. Then impedance values in ACF flip-chip interconnection were extracted from cascade transmission matrix. ACF flip chip interconnection has only below 0.1nH, and very stable up to 13 GHz. Over the 13 GHz, there was significant loss because of epoxy capacitance of ACF. However, the addition of SiO$_2$filler to the ACF lowered the dielectric constant of the ACF materials resulting in an increase of resonance frequency up to 15 GHz. High frequency behavior of metal Au stud bumps was investigated. The resonance frequency of the metal stud bump interconnects is higher than that of ACF flip-chip interconnects and is not observed at the microwave frequency band. The extracted model parameters of adhesive flip chip interconnects were analyzed with the considerations of the characteristics of material and the design guideline of ACA flip chip for high frequency applications was provided.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.337-349
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• 2007

Yearly, it seems the fact that the numbers of tunnels with wide sections are on the rise as the length of tunnel and number of lanes continues increasing. According to these trends, well-schemed plans of design, construction and management related with tunnel safety has become to be crucial. It is a high possibility to be observed by the fact that the direct effects of casualties and property damages are caused by the situations of car collisions, bump to solid structures by careless driving and the outbreak on vehicles by mechanical fault. Therefore, in order to prevent these types of accidents, we would make issues md adopt appropriate mechanical and management plans of emergency exits and disaster prevention equipments inside of tunnel, based on up-to dated experiences and study of foreign cases, to structural design technology. The objectives of this study are to recognize related actual problems and suggest improvement plans.

• The Korea Journal of Herbology
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• v.31 no.4
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• pp.61-69
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• 2016

Objectives : This study is to propose discriminative keys with stereoscope for minute seed herbs easily mixed up, but hard to discriminate by naked eyes: Alli Tuberosi Semen(ATS)✳Alli Fistulosi Semen(AFS), Malvae Semen(MS)✳ Abutili Semen(AS), Plantaginis Semen(PS)✳Schizonepetae Semen(SS).Objectives : We reviewed the description of original plants and medicinal herbs from literature. The specimen of original plant were collected, determinated and compared to samples in the market. Primary classification was performed with naked eyes. and we found out other discrimination keys for non-distinctive herbs with stereoscope. Discrimination keys were set as the morphological criteria of authentic herbs, percentage of adulteration, and standards for discriminating genuine herbs from adulteration.Results : 1) ATS is bigger, has reticulate pattern on protuberant side and unique garlic chives taste. AFS which is usually mixed up, is smaller, has 1~2 ridges and unique welsh onion taste. 2) MS is smaller, has no villus, but its length of bumps are similar. AS easily mixed up, is bigger and has white villus. Its upper side bump is longer and more sharp. 3) PS has dent at middle of the back side. It becomes very sticky when it is put or boiled in water. SS which can be mixed up has no dent and low viscosity compared to PS.Conclusions : With this result, we propose discriminative keys which can identify the original plants and processed herbal state of six herbs. Because minute medicinal herbs are hardly distinguishable by sensory test, It is essential to differentiate by using stereoscope.

• ETRI Journal
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• v.26 no.6
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• pp.583-588
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• 2004

In this paper we investigate the effect of a shield metal line inserted between adjacent bit lines on the refresh time and noise margin in a planar DRAM cell. The DRAM cell consists of an access transistor, which is biased to 2.5V during operation, and an NMOS capacitor having the capacitance of 10fF per unit cell and a cell size of $3.63{\mu}m^2$. We designed a 1Mb DRAM with an open bit-line structure. It appears that the refresh time is increased from 4.5 ms to 12 ms when the shield metal line is inserted. Also, it appears that no failure occurs when $V_{cc}$ is increased from 2.2 V to 3 V during a bump up test, while it fails at 2.8 V without a shield metal line. Raphael simulation reveals that the coupling noise between adjacent bit lines is reduced to 1/24 when a shield metal line is inserted, while total capacitance per bit line is increased only by 10%.