• Journal of Periodontal and Implant Science
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• v.43 no.6
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• pp.301-307
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• 2013

Purpose: This in vitro study was performed to assess the adherence of Porphyromonas gingivalis to a resorbable blast media (RBM) titanium surface pretreated with an ultrasonic scaler or toothbrush and to evaluate the effects of the treatment of the RBM titanium discs on the bacterial removal efficiency of brushing by crystal violet assay and scanning electron microscopy. Methods: RBM titanium discs were pretreated with one of several ultrasonic scaler tips or cleaned with a toothbrush. Then the titanium discs were incubated with P. gingivalis and the quantity of adherent bacteria was compared. The disc surfaces incubated with bacteria were brushed with a toothbrush with dentifrice. Bacteria remaining on the disc surfaces were quantified. Results: A change in morphology of the surface of the RBM titanium discs after different treatments was noted. There were no significant differences in the adherence of bacteria on the pretreated discs according to the treatment modality. Pretreatment with various instruments did not produce significant differences in the bacterial removal efficiency of brushing with dentifrice. Conclusions: Within the limits of this study, various types of mechanical instrumentation were shown to cause mechanical changes on the RBM titanium surface but did not show a significant influence on the adherence of bacteria and removal efficiency of brushing.

• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.723-733
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• 2016

Intensive researches have been focused on the 3-dimensional packaging technology using through silicon via (TSV) to overcome the limitation in Cu interconnection scaling. Void-free filling of TSV by the Cu electrodeposition is required for the fabrication of reliable electronic devices. It is generally known that sufficient inhibition on the top and the sidewall of TSV, accompanying the selective Cu deposition on the bottom, enables the void-free bottom-up filling. Organic additives contained in the electrolyte locally determine the deposition rate of Cu inside the TSV. Investigation on the additive chemistry is essential for understanding the filling mechanisms of TSV based on the effects of additives in the Cu electrodeposition process. In this review, we introduce various filling mechanisms suggested by analyzing the additives effect, research on the three-additive system containing new levelers synthesized to increase efficiency of the filling process, and methods to improve the filling performance by modifying the functional groups of the additives or deposition mode.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.4
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• pp.15-24
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• 2008

In this paper, we propose a Cross-Layer Transmission Architecture (CLTA) to support power saving high-speed multimedia services in mobile ad-hoc wireless sensor networks(MAWSN). The main goals of this paper are in showing and proposing how the routing routes are decided on route stability based on mobility of mobile nodes to increase the operational lifetime of routes as well as how the transmit power can be saved in mobile ad-hoc wireless sensor networks. To obtain these goals, we propose a cross-layer architecture strategy which combines network layer technology with physical layer technology to get synergy effects in the view of transmission power saving. We consider a realistic approach, in the points of view of the MAWSN, based on mobile sensor nodes as well as fixed sensor nodes in sensor fields while the conventional research for sensor networks focus on mainly fixed sensor nodes. The performance evaluation of the proposed CLTA is performed via simulation and analysis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.7
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• pp.705-711
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• 2003

In this Paper, 2${\times}$100 $\mu\textrm{m}$ AlCaN/GaN HEMT's(on sapphire substrate) large signal model including thermal effect was extracted. An equation based empirical model was employed to make large signal model for convergence and high speed. Pulsed I-V measurement was performed to extract thermal resistance and capacitance. Power amplifiers with 9 mm and 15 mm AlCaN/GaN HEMTS were designed using scaled modeling results of 2${\times}$100 $\mu\textrm{m}$ device respectively. From comparisons between measured and simulated data, the model considering of thermal effects gave better agreement than without one. It demonstrates that thermal modeling must be performed for power amplifier that uses large size transistors.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.2
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• pp.99-108
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• 2020

In the field of aircraft icing prediction, surface roughness has been considered as critical factor because it enhances convective heat transfer and changes local collection efficiency. For this significance, experimental studies have been conducted to acquire the quantitative data of the formation process. Meanwhile, these experiments was conducted under low-speed condition due to the measurement difficulties. However, it has not been investigated that how the flow characteristic of low-speed will effects to the surface roughness. Therefore, the present study conducted experiment under low-speed icing condition, and analyzed the relation between surface roughness characteristics and icing condition. As an analysis method, the dominant parameters used in the previous high-speed experiments are employed, and roughness characteristics are compared. The size of roughness element was consistent with the previous known tendency, but not the smooth zone width.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.578-590
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• 2017

An agricultural waste, pomegranate (Punica granatum L.) peel is known to be rich in total phenolics, which are flavonoids having strong antioxidant effects. In this study, pomegranate peel sponge cakes were prepared with varying ratios of freeze dried pomegranate peel powder (0, 1, 3, 5, 7% (w/w)) to examine their effect on quality characteristics, retrogradation and antioxidant activities. The specific gravity and moisture contents of 3, 5, and 7% pomegranate peel powder showed higher values than the control and 1% group. Addition of pomegranate peel powder increased the batter yield, while there was a significant decrease in baking loss. Increasing pomegranate peel powder content significantly decreased the lightness (L) (from 75.03 to 57.04) and pH values, whereas redness (a), yellowness (b) and ${\Delta}E$ were increased. Increasing concentration of the peel powder also increased the hardness and chewiness, while the springiness and cohesiveness decreased. Considering the Avrami equation, Avrami exponene (n) decreased from 1.8055 (control) to 0.9199 (7% pomegranate peel powder). Time constant (1/k) was lowest in control (at 17.64) and highest in the 7% group (39.84). Total polyphenol, flavonoid content, DPPH and ABTS radical scavenging activities significantly increased with increments in the content of pomegranate peel powder. A sensory evaluation by the 7-point scaling method showed that the sponge cake containing 7% pomegranate peel powder had the highest scores in color, flavor, sweetness, chewiness and overall acceptability. Hence, it is considered that sponge cake supplemented with 7% pomegranate peel powder is the most appropriate for quality characteristics, retrogradation and antioxidant activities.

• Journal of dental hygiene science
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• v.17 no.3
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• pp.202-208
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• 2017

Korea has been running the community oral health program for the elderly, including topical fluoride application and scaling. The aim of this study was to compare the subjective and objective oral health status of 345 participants according to the number of participants in the program and of 37 participants before and after the 5-year program. The survey consisted of an interview questionnaire and oral examinations. Analysis of variance was used to compare the variables of the 345 participants according to the numbers of participants. Paired t-test was used to compare the oral health statuses before and after the 5-year program in 37 subjects. There was no difference in subjective oral health status according to the number of participants in the oral health program in the elderly, including subjective health status, subjective oral health status, satisfaction with oral health, concern about oral health, need of dental treatment, oral pain, tooth sensitivity, subjective periodontal health, and subjective symptoms of periodontitis. The community periodontal index (CPI) of the 1 time participants was significantly higher than that of 3 times, 4 times or 5 times participants in the upper center, lower left, lower center, and lower right areas. There was a significant improvement in CPI from $2.59{\pm}1.14$ to $1.41{\pm}1.54$ (p<0.001) and positive oral behavioral change (daily tooth brushing frequency from $2.27{\pm}0.73$ to $2.54{\pm}0.90$) before and 5 years after the program. However, the program did not prevent tooth loss as the numbers of the remaining teeth significantly reduced from $23.77{\pm}1.84$ to $21.95{\pm}2.03$ over 5 years. We showed that running the community oral health program for the elderly for more than three years might have positive effects on the periodontal health of participants.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.25-31
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• 2010

It is known from consumer surveys that the interior design of cars greatly influences on consumers' affection. Most notably, the instrument panel which occupies the driver's attention while driving would be one of the main components that affect consumer's affection, but the designer does not often put due importance to this design component. The purpose of this study is to define consumers' affection on the instrument cluster panel in terms of its design factors: color of panel lighting and layout of meters as independent factors. Semantic differentials or affective adjectives that are related to the instrument panel were first derived from surveys, existing studies and the available literature. Then, representative affective factors were drawn using factor analysis and multi-dimensional scaling (MDS). Evaluation of the instrument panel was performed and analyzed by Taguchi's robust design to provide more robust results under various noise factors which are color and material of car interior. Experiment revealed that consumers had five affective factors on the instrument panel and luxurious, charming, and visible affections are grouped into a factor and unique and dynamic affections in another factor. Evaluation of the instrument panel by Taguchi's robust design found that the white color of panel lighting and the panel with four meters was the most preferred design in terms of both the affection of luxury and uniqueness.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.368-378
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• 2019

Logic trees for probabilistic tsunami hazard assessment include numerous variables to take various uncertainty on earthquake generation into consideration. Results from the hazard assessment vary in different way as more variables are considered in the logic tree. This study is conducted to estimate the effects of various scaling laws and fault parameters on tsunami hazard at the nearshore of Busan. Active fault parameters, such as strike angle, dip angle and asperity, are adjusted in the modelling of tsunami propagation, and the numerical results are used in the sensitivity analysis. The influence of strike angle to tsunami hazard is not as much significant as it is expected, instead, dip angle and asperity show a considerable impact to tsunami hazard assessment. It is shown that the dip angle and the asperity which determine the initial wave form are more important than the strike angle for the assessment of tsunami hazard in the East Sea.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.847-853
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• 2016

Applications of Si have been increasingly exploited and extended to More-Moore, More-than-Moore, and beyond-CMOS approaches. Ge is regarded as one of the supplements for Si owing to its higher carrier mobilities and peculiar band structure, facilitating both advanced and optical applications. As an emerging metal-oxide device, the junctionless field-effect transistor (JLFET) has drawn considerable attention because of its simple process, less performance fluctuation, and stronger immunity against short-channel effects due to the absence of anisotype junctions. In this study, we investigated lateral field scalability, which is equivalent to channel-length scaling, in Si and Ge JLFETs. Through this, we can determine the usability of Si CMOS and hypothesize its replacement by Ge. For simulations with high accuracy, we performed rigorous modeling for ${\mu}_n$ and ${\mu}_p$ of Ge, which has seldom been reported. Although Ge has much higher ${\mu}_n$ and ${\mu}_p$ than Si, its saturation velocity ($v_{sat}$) is a more determining factor for maximum $I_{on}$. Thus, there is still room for pushing More-Moore technology because Si and Ge have a slight difference in $v_{sat}$. We compared both p- and n-type JLFETs in terms of $I_{on}$, $I_{off}$, $I_{on}/I_{off}$, and swing with the same channel doping and channel length/thickness. $I_{on}/I_{off}$ is inherently low for Ge but is invariant with $V_{DS}$. It is estimated that More-Moore approach can be further driven if Si is mounted on a JLFET until Ge has a strong possibility to replace Si for both p- and n-type devices for ultra-low-power applications.