• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.809-822
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• 1998

Adequate root preparation in the treatment of periodontal disease often involves mechanical instrumentation to remove plaque, calculus perhaps contaminated cementum. Although meticulous scaling and root planing may remove some cementum, the use of aggressive root planing to remove cementum does not appear warranted. So ultrasonic device and rotary instrument appear to be replacing hand instrument. But it is not clear those instruments make smooth root surface as hand instrument. The roghness of the root surface were evaluate with SEM following instrumentation with Gracey curette, Perio Clean and piezo ultrasonic device(Setlec) with various tip. 20 extracted teeth were used in vitro experiment, and 9 teeth of a patient destined for extraction for periodontal reasons were utilized in vivo experiment. It was demonstrated that hand curette created the smoothest surface, while diamond tip tended to roughen the root surface. But the hand curette, Perio Clean, and piezo ultasonic device with scaler tip tend to remove cementum completely. Piezo ultrasonic device with curette-like tip made the desirable smooth surface with partial removal of cementum.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.659-669
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• 2004

The aim of this study was to evaluate the clinical efficacy of mouthrinses prepared by sterilized water-generating $device(Purister^{(R)})$ on the control of gingivitis and incipient periodontitis when it was used as a adjunctives to the mechanical plaque control. 40 healthy patients with gingivitis or incipient periodontitis were divided into two groups. Patients in the experimental group use mouthrinses prepared by sterilized water-generating $device(Purister^{(R)})$ after tooth brushing while patients in the control group do only tooth brushing for plaque control. All patients received scaling and tooth brushing instruction. 1 week after scaling was set as baseline. Probing pocket depth, clinical attachment level, and bleeding on probing were scored at baseline, 4 weeks. Gingival index and plaque index were scored at baseline, 2 weeks, and 4 weeks. The results were as follows: 1. In the experimental group, gingival index, plaque index, probing pocket depth, and clinical attachment level showed statistically significant decrease, but in the control group, significant increase(p<0.05). 2. There was no significant difference between the experimental and the control group in bleeding on probing, but significant decrease in the experimental group and Significant increase in the control group In a time-dependent manner(p <0.05). From these results, it can be concluded that regular use of mouthrinses prepared by sterilized water-generating $device(Purister^{(R)})$ as adjunctives of mechanical plaque control, may be effective to prevent and treat gingivitis and incipient periodontitis.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.107-112
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• 2011

This paper is for improving the RF frequency performance of a fabricated 100nm ${\Gamma}$-gate MHEMT, scaling down vertically for the epitaxy-structure layers of the device. Hydrodynamic simulation parameters are calibrated for the fabricated MHEMT with the modulation-doped $In_{0.52}Al_{0.48}As/In_{0.53}Ga_{0.47}$As heterostructure grown on the GaAs substrate. With these calibrated parameters, simulations for the vertically-scaled epitaxial layers of the device are performed and analyzed for DC/RF characteristics, including the quantization effect due to the thickness reduction of InGaAs channel layer. A newly designed epitaxy-structure device shows higher extrinsic transconductance, $g_m$ of 1.556 S/mm, and higher frequency performance, $f_T$ of 222.5 GHz and $f_{max}$ of 849.6 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.683-685
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• 2012

This paper have presented the analysis of the change for threshold voltage and drain induced barrier lowering among short channel effects occurred in subthreshold region for double gate(DG) MOSFET with two gates to be next-generation devices, based on scaling theory. To obtain the analytical solution of Poisson's equation, Gaussian function been used as carrier distribution to analyze closely for experimental results, and the threshold characteristics have been analyzed for device parameters such as channel thickness and doping concentration and projected range and standard projected deviation of Gaussian function. Since this potential model has been verified in the previous papers, we have used this model to analyze the threshold chatacteristics. As a result to apply scaling theory, we know the threshold voltage and drain induced barrier lowering is changed, and the deviation rate is changed for device parameters for DGMOSFET.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.1
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• pp.30-37
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• 2006

In this article, we evaluated the structural merits and the validity of a partially insulated MOSFET (PiFET) through the fabrication of prototype transistors and an 80 nm 512M DDR DRAM with partially-insulated cell array transistors (PiCATs). The PiFETs showed the outstanding short channel effect immunity and off-current characteristics over the conventional MOSFET, resulting from self-induced halo region, self-limiting SID shallow junction, and reduced junction area due to PiOX layer formation. The DRAM with PiCATs also showed excellent data retention time. Thus, the PiFET can be a promising alternative for ultimate scaling of planar MOSFET.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.193-203
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• 1998

20 Subjects with clinical diagnosis of adult periodontitis with sites having average pocket depth of 4mm were selected for the study. After scaling and root planing of those sites, 30% minocycline-HCI contained in biodegradable device were inserted in one group, scaling and root planing was carried out in another group and the last group was without any periodontal treatment. the difference between the group was detemined by pocket dept, bleeding on prbing, attachment level, distribution of subgingval plaque bacteria. Conclusion was made for the comparisons between baseline and 4 week and the groups. 1. In analysis of pocket depth, there was significant sifference in scaling and root planing group only. 2. Both the scaling and root planing group and minocycline group showed significant decrease in bleeding on probing. 3. There was significant increase in the attachment level in scaling and root planing group, but no difference was foundbetween the groups. 4. There was significant decrease in the total number of subgingival bacteria in all groups and the number of motile bacteria decreased significantly in the minocycline group. These result indicate that insertion of Minocycline-HCI at the base of periodntal pocket was useful as an additional aid of mechanical trarment at the point of periodontal pocket, bleeding on probing, attachment level, microbial distribution.

• Korean Journal of Dental Materials
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• v.43 no.1
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• pp.17-28
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• 2016

The aim of this study was to evaluate the changes in dentinal permeability after application of dentin desensitizer on exposed dentin immediately after ultrasonic scaling to teeth with non-carious cervical lesions. Thirty caries-free extracted molars were fixed to slide glasses after horizontally being sectioned at 5 mm below the cemento- enamel junction (CEJ). The prepared specimen was connected to a fluid flow measuring device (nano-Flow), and a V-shaped cavity was formed at the CEJ to imitate the non-carious cervical lesion. After no fluid leakage was confirmed in the connected system with specimen, tooth surface was treated ultrasonic cleaning with piezoelectric ultrasonic scalers until dentinal tubules were exposed. And 6 different desensitizers were applied on exposed dentin. Real-time measurements of dentinal fluid flow were performed during ultrasonic scaling and application of dentin desensitizer. To evaluate the occlusion of exposed dentinal tubules, tooth surface was examined by SEM. Following results were observed. After ultrasonic scaling, more dentinal tubules were exposed on the tooth with non-carious cervical lesions compared to tooth without lesions. The rate of fluid flow measured with nano-Flow system had correlation with the degree of dentin occlusion observed with SEM after application of desensitizers on exposed dentin. Desensitizers with glutaraldehyde and HEMA did not decrease the rate of fluid flow and did not show dentin occlusion. Desensitizers with oxalate showed the limited effects on the rate of fluid flow and dentinal tubule occlusion. Desensitizer with resin monomer showed the significant effect on the rate of fluid flow and dentin occlusion.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.573-579
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• 2001

The technology for characteristic analysis of device for high integration is changing rapidly. Therefore to understand characteristics of high -integrated device by computer simulation and fabricate the device having such characteristics became one of very important subjects. As devices become smaller from submicron to nanometer, we have investigated MOSFET built on an epitaxial layer(EPI) of a heavily-doped ground plane by TCAD(Technology Computer Aided Design) to develop optimum device structure. We analyzed and compared the EPI device characteristics such as impact ionization, electric field and I-V curve with those of lightly doped drain(LDD) MOSFET. Also, we presented that TCAD simulator is suitable for device simulation and the scaling theory is suitable at nano structure device.

• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.186-196
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• 2013

Since its introduction (e.g., [4, 6]), virtual coupling technique has been de facto way to connect a haptic device with a virtual proxy for haptic rendering and control. However, because of the single dependence on spring-damper feedback action, this virtual coupling suffers from the degraded transparency particularly during contact tasks when large device/proxy-forces are involved. In this paper, we propose a novel virtual coupling technique, which, by utilizing passive decomposition, reduces device-proxy position deviation even during the contact tasks while also scaling down (or up) the apparent inertia of the coordinated device-proxy. By doing so, we can significantly improve transparency between multiple degree of freedom (possibly nonlinear) haptic device and virtual proxy. In other to use passive decomposition, disturbance observer of [3] is adopted to estimate human force with some dead-zone modification to avoid "winding-up" force estimation in the presence of device torque saturation. Some preliminary experimental results are also given to illustrate efficacy of the proposed technique.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.2
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• pp.68-73
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• 2006

We propose a damascene gate FinFET with Si nanocrystals implemented on bulk silicon wafer for low voltage flash memory device. The use of optimized SRON (Silicon-Rich Oxynitride) process allows a high degree of control of the Si excess in the oxide. The FinFET with Si nanocrystals shows high program/erase (P/E) speed, large $V_{TH}$ shifts over 2.5V at 12V/$10{\mu}s$ for program and -12V/1ms for erase, good retention time, and acceptable endurance characteristics. Si nanocrystal memory with damascene gate FinFET is a solution of gate stack and voltage scaling for future generations of flash memory device. Index Terms-FinFET, Si-nanocrystal, SRON(Si-Rich Oxynitride), flash memory device.