• The Journal of Advanced Prosthodontics
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• v.10 no.1
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• pp.8-17
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• 2018

PURPOSE. The study aimed to identify the accuracy and reproducibility of preparations made by gypsum materials of various colors using quantitative and semi-quantitative three-dimensional (3D) approach. MATERIALS AND METHODS. A titanium maxillary first molar preparation was created as reference dataset (REF). Silicone impressions were duplicated from REF and randomized into 6 groups (n=8). Gypsum preparations were formed and grouped according to the color of gypsum materials, and light-scanned to obtain prepared datasets (PRE). Then, in terms of accuracy, PRE were superimposed on REF using the best-fit-algorithm and PRE underwent intragroup pairwise best-fit alignment for assessing reproducibility. Root mean square deviation (RMSD) and degrees of similarity (DS) were computed and analyzed with SPSS 20.0 statistical software (${\alpha}=.05$). RESULTS. In terms of accuracy, PREs in 3D directions were increased in the 6 color groups (from 19.38 to $20.88{\mu}m$), of which the marginal and internal variations ranged $51.36-58.26{\mu}m$ and $18.33-20.04{\mu}m$, respectively. On the other hand, RMSD value and DS-scores did not show significant differences among groups. Regarding reproducibility, both RMSD and DS-scores showed statistically significant differences among groups, while RMSD values of the 6 color groups were less than $5{\mu}m$, of which blue color group was the smallest ($3.27{\pm}0.24{\mu}m$) and white color group was the largest ($4.24{\pm}0.36{\mu}m$). These results were consistent with the DS data. CONCLUSION. The 3D volume of the PREs was predisposed towards an increase during digitalization, which was unaffected by gypsum color. Furthermore, the reproducibility of digitalizing scanning differed negligibly among different gypsum colors, especially in comparison to clinically observed discrepancies.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.12
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• pp.1485-1492
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• 1999

대규모 시스템 명세의 올바름을 검증하기 위한 유한 상태 LTS에 기반을 둔 CTL논리 적용에 있어 가장 큰 문제점은, 시스템 내부의 병렬 프로세스간의 상호작용으로 인한 상태폭발이다. 그러나 Modal mu-calculus 논리를 시스템 안전성 및 필연성 특성 명세에 사용하면, 행위에 의한 순환적 정의가 가능하므로 상태폭발 문제가 해결 가능하다. 본 논문에서는 LTS로 명세화된 통신 프로토콜 시스템 모델의 안전성 및 필연성 특성을 모형 검사 기법에 의해 검증함에 있어, 시제 논리로 사용된 Modal mu-calculus 안전성 및 필연성 논리식과 CTL 의 안전성 및 필연성 논리식의 극한값이 동일함을 두 논리식을 만족하는 상태 집합이 같다는 것을 보임으로써 증명한다. 증명된 결과는 I/O FSM 모델로 표현된 통신 프로토콜의 안전성 및 필연성 검사를 위해 이론적인 기반으로서, 컴퓨터를 이용한 모형검사 기법에 효과적인 방법으로 응용이 가능하다.Abstract In applying CTL-based model checking approach to correctness verification of large state transition system specifications, the major obstacle is the combinational explosion of the state space arising due to interaction of many loosely coupled parallel processes. If, however, the modal mu-calculus viewed as a CTL-based logic with recursion, is used to specify the safety and liveness property of a given system, it is possible to resolve this problem. In this paper, we discuss the problem of verifying communication protocol system specified in LTS, and prove that a logic expression specifying safety and liveness in modal mu-calculus is semantically identical to the maximum value of the expression in CTL. This relation is verified by the proof that the sets of states satisfying the two logic expressions are equivalent. The proof can be used as a theoretical basis for verifying safety and liveness of communication protocols represented as I/O FSM model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.2
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• pp.323-329
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• 2002

This paper describes an efficient error-compensation technique for designing a low-error truncated Booth multiplier which produces an N-bit output from a two's complement multiplication of two N bit inputs by eliminating the N least-significant bits. Applying the proposed method, a truncated Booth multiplier for area-efficient and low-power applications has been designed, and its performance(truncation error, area) was analyzed. Since the truncated Booth multiplier does not have about half the partial product generators and adders, it results an area reduction of about 35％, compared with no-truncated parallel multipliers. Error analysis shows that the proposed approach reduces the average truncation error by approximately 60％, compared with conventional methods. A 16-b$\times$16-b truncated Booth multiplier core is designed on full-custom style using 0.35-${\mu}{\textrm}{m}$ CMOS technology. It has 3,000 transistors on an area of 330-${\mu}{\textrm}{m}$$\times$262-${\mu}{\textrm}{m}$ and 20-㎽ power dissipation at 3.3-V supply with 200-MHz operating frequency.

• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.54-59
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• 2008

The most pivotal approach to improve subway indoor air quality (IAQ) is to examine the emission sources and particulate behavior. Therefore, the main objective of this study is to investigate the particulate behavior in the subway. In order to examine IAQ in the subway, a sampling and measurement campaign was carried out for 35 sites during the summer and winter seasons from May, 2005 to February, 2006. In case of 24 hour measurement, the mean concentrations ($PM_{10}$-24 hr) of platform and waiting room were $156.18{\pm}53.79{\mu}g/m^3$ and $111.00{\pm}53.31{\mu}g/ m^3$. Besides, as a result of 20 hour measurement, the mean concentrations ($PM_{10}$-20 hr) of platform and waiting room were $146.09{\pm}53.71{\mu}g/m^3$ and $99.08{\pm}42.77{\mu}g/m^3$, respectively. In general, $PM_{10}$-24 hr was higher than $PM_{10}$-20 hr, and both PM concentrations showed a high correlation coefficient (r=0.803). It was found that the $PM_{2.5}$ concentration ($l09.56{\pm}28.24{\mu}g/m^3$) in winter was higher than that ($83.66{\pm}57.82{\mu}g/m^3$) in summer.

• International Journal of Oral Biology
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• v.36 no.3
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• pp.143-148
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• 2011

The present study investigated the role of peripheral P2X receptors in inflammatory pain transmission in the orofacial area in rats. Experiments were carried out on male Sprague-Dawley rats weighing 220 to 280 g. Formalin (5%, 50 ${\mu}L$) and complete Freund's adjuvant (CFA, 25 ${\mu}L$) was applied subcutaneously to the vibrissa pad to produce inflammatory pain. TNP-ATP, a $P2X_{2,2/3,4}$ receptor antagonist, or OX-ATP, a $P2X_7$ receptor antagonist, was then injected subcutaneously at 20 minutes prior to formalin injection. One of the antagonists was administered subcutaneously at three days after CFA injection. The subcutaneous injection of formalin produced a biphasic nociceptive behavioral response. Subcutaneous pretreatment with TNP-ATP (80, 160 or 240 ${\mu}g$) significantly suppressed the number of scratches in the second phase produced by formalin injection. The subcutaneous injection of 50 ${\mu}g$ of OX-ATP also produced significant antinociceptive effects in the second phase. Subcutaneous injections of CFA produced increases in mechanical and thermal hypersensitivity. Both TNP-ATP (480 ${\mu}g$) and OX-ATP (100 ${\mu}g$) produced an attenuation of mechanical hypersensitivity. However, no change was observed in thermal hypersensitivity after the injection of either chemical. These results suggest that the blockade of peripheral P2X receptors is a potential therapeutic approach to the onset of inflammatory pain in the orofacial area.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.106-113
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• 2012

The present study was conducted to assess the dietary exposure to mercury and the associated risks for Koreans resulting from their food intake. The probabilistic approach in the Monte Carlo simulation was used to estimate dietary exposures. Based on several reports regarding heavy metals published by KFDA in the 2000s, 178 types of representative foods were selected and data were collected on the occurrence of mercury. The contents of mercury in foods ranged: agricultural products 0.1 (fruits)-45.4 ${\mu}g/kg$ (mushrooms), 3.7 ${\mu}g/kg$ (meat), and 9.3 (Echinodermata, chordata)-194.9 ${\mu}g/kg$ (fish). Others categories investigated were alcoholic beverages (0.7 ${\mu}g/kg$) and processed food (4.4 ${\mu}g/kg$). The mean and 95th percentile for exposure to dietary mercury were 4.29 and 12.48 ${\mu}g/day$, corresponding to 13.6% and 39.7% of PTWI (Provisional Tolerable Weekly Intake), respectively. Therefore, overall level of mercury exposure for Koreans through food intake is below levels recommended by JECFA, indicating the least possibility of risk, and is less than or similar to levels reported in other countries.

• Biotechnology and Bioprocess Engineering:BBE
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• v.1 no.1
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• pp.26-31
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• 1996

Since biosynthesis of lignin peroxidase from Phanerochaete chrysosporium was known to be sensitive to shear, it is interesting to understand the effects of the shear sensitivity for the overproduction of lignin peroxidase. In stirred-tank fermentor, the shear-sensitivity in lignin peroxidase biosynthesis was quantified by using Kolmogorov length scale. It was found that agitation at 80$\mu$m Kolmogorov length scale is advantageous for the production of lignin peroxidase from P. chrysosporium. To overcome the shear sensitivity in lignin peroxidase biosynthesis caused by the agitation,P. chrysosporium was immobilized on various solid carriers. The nylon-immobilized P. chrysosporium was chosen in the present study as a way to overcome the shear sensitivity at the ranges of above 50$\mu$m Kolmogorov length scale. The adhesion force between immobilized cell and carrier can be predicted by thermodynamic approach and used as a criteria to select an adequate carrier materials for immobilization.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.3058-3060
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• 2005

In this paper, the CMOS four-quadrant analog multipliers for low-voltage low-power applications are presented. The circuit approach is based on the characteristic of the LV (Low-Voltage) composite transistor which is one of the useful analog building blocks. SPICE simulations are carried out to examine the performances of the designed multipliers. Simulation results are obtained by $0.25{\mu}m$ CMOS parameters with 2V power supply. The LV composite transistor can easily be extended to perform a four-quadrant multiplication. The multiplier has a linear input range up to ${\pm}0.5V$ with a linearity error of less than 1%. The measured -3dB bandwidth is 290MHz and the power dissipation is $37{\mu}W$. The proposed multiplier is expected to be suitable for analog signal processing applications such as portable communication equipment, radio receivers, and hand-held movie cameras.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.4
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• pp.18-22
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• 2006

Although many efforts have been made in making nanometer-sized holes, there is still a major challenge in fabricating individual single-digit nanometer holes in a more controllable way for different materials, size distribution and hole shapes. In this paper we describe our efforts to use a top down approach in nanofabrication method to make single-digit nanoholes. There are three major steps towards the fabrication of a single-digit nanohole. 1) Preparing the freestanding thin film by epitaxial deposition and electrochemical etching. 2) Making sub-micro holes ($0.2{\mu}\;to\;0.02{\mu}$) by focused ion beam (FIB), electron beam (EB), atomic force microscope (AFM), and others methods. 3) Reducing the hole size to less than 10 nm by epitaxial deposition, FIB or EB induced deposition and micro coating. Preliminary work has been done on thin films (30 nm in thickness) preparation, sub-micron hole fabrication, and E-beam induced deposition. The results are very promising.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.123-128
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• 2014

In this study, we have investigated the flow rate effects of Ag nanoparticle (NP) suspensions on the progress of the cell cycle by using a microfluidic image cytometry (${\mu}FIC$)-based approach. Compared with the conventional "static" exposure conditions, enhancements in G2 phase arrest were observed for the cells under continuously flowing "dynamic" exposure conditions. The "dynamic" exposure conditions, which mimic in vivo systems, induced an enhanced cytotoxicity by accelerating G2 phase arrest and subsequent apoptosis processes. Moreover, we have also shown that the increases in delivered NP dose due to the continuous supply of Ag NPs contributed dominantly to the enhanced cytotoxicity observed under the "dynamic" exposure conditions, while the shear stress caused by these slowly flowing fluids (i.e., flow rates of 6 and $30{\mu}L/h$) had only a minor influence on the observed enhancement in cytotoxicity.