• Restorative Dentistry and Endodontics
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• v.47 no.2
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• pp.20.1-20.14
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• 2022

Objectives: The study investigated the difficulties experienced by endodontics researchers around the world in conducting studies and writing papers. Materials and Methods: A survey consisting of 18 questions on the difficulties experienced by endodontics researchers in performing studies and writing papers was e-mailed to academics in the field of endodontics working at 202 universities. The independent risk factors were analyzed using binary logistic regression at a significance level of 0.05. Results: A total of 581 individuals (10.7%) agreed to participate in the study. Almost half the participants (48.2%) reported that they had received some type of training in conducting studies and writing papers. In response to the question, "Do you get help from a statistician to perform the statistical analyses of your studies?," 77.1% answered "yes." Around 40% of the participants stated that the need to obtain ethical approval negatively affected their desire to conduct studies. The participants' regions had no effect on the reported difficulties associated with writing papers in English or conducting statistical analyses (p > 0.05). Most participants (81.8%) reported difficulties in writing the Discussion section, regardless of their region, academic degrees, or years of experience. Conclusions: The participants stated they experienced difficulties in many areas, such as conducting statistical analyses, finding new ideas, and writing in English. Engaging in a detailed examination of ethics committee rules, expanding biostatistics education, increasing the number of institutions providing research funding, and increasing the number of endodontics journals can increase the enthusiasm of endodontics researchers to publish papers.

• Imaging Science in Dentistry
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• v.53 no.4
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• pp.365-373
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• 2023

Purpose: In the context of COVID-19, studies evaluating the adherence of dentists and dental students to infection control are relevant due to their high occupational exposure and risk, as well as their responsibility for disseminating information and good practices. This study evaluated the adherence of dentists and dental students to infection control in the oral radiology field in the setting of the COVID-19 pandemic on different continents. Materials and Methods: This cross-sectional observational study involved individuals who performed intraoral radiographic examinations during the COVID-19 pandemic. The Questionnaire on Infection Control in Oral Radiology was administered virtually using a Google Form. Participants from different continents(the Americas, Africa, Europe, Asia, and Oceania) were recruited. Data were subjected to descriptive analysis and simple and multiple binary regression (5%). Results: There were 582 valid answers, and 68.73% of the participants were from the Americas, 18.90% from Europe, and 12.37% from Asia. The median score for infection control protocols was 94 points for dental students and 104 points for dentists, and participants below the median were considered to have low adherence to infection control in oral radiology. Low access to infection control was found for 53.0% of dentists in the Americas, 34.0% from Europe, and 26.9% from Asia. Conclusion: The adherence to infection control protocols in oral radiology was low even in the face of the COVID-19 pandemic. The results may help improve the awareness of students and professionals, since oral radiology routines have the potential for transmitting COVID-19.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.51-59
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• 2024

Collecting a dataset with a corresponding labeled gaze vector requires a high cost in the gaze estimation field. In this paper, we suggest a data augmentation of manipulating the gaze of an original image, which improves the accuracy of the gaze estimation model when the number of given gaze labels is restricted. By conducting multi-class gaze bin classification as an auxiliary task and adjusting the latent variable of the diffusion model, the model semantically edits the gaze from the original image. We manipulate a non-binary attribute, pitch and yaw of gaze vector to a desired range and uses the edited image as an augmented train data. The improved gaze accuracy of the gaze estimation network in the semi-supervised learning validates the effectiveness of our data augmentation, especially when the number of gaze labels is 50k or less.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.1
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• pp.91-105
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• 2016

Carbon Nanotube Field-Effect Transistors (CNTFETs) have been studied as candidates for post Si CMOS owing to the better electrostatic control and high mobility. To enhance the immunity against short - channel effects (SCEs), the novel channel and gate engineered architectures have been proposed to improve CNTFETs performance. This work presents a comprehensive study of the influence of channel and gate engineering on the CNTFET switching, high frequency and circuit level performance of carbon nanotube field-effect transistors (CNTFETs). At device level, the effects of channel and gate engineering on the switching and high frequency characteristics for CNTFET have been theoretically investigated by using a quantum kinetic model. This model is based on two-dimensional non-equilibrium Green's functions (NEGF) solved self - consistently with Poisson's equations. It is revealed that hetero - material - gate and lightly doped drain and source CNTFET (HMG - LDDS - CNTFET) structure can significantly reduce leakage current, enhance control ability of the gate on channel, improve the switching speed, and is more suitable for use in low power, high frequency circuits. At circuit level, using the HSPICE with look - up table(LUT) based Verilog - A models, the impact of the channel and gate engineering on basic digital circuits (inverter, static random access memory cell) have been investigated systematically. The performance parameters of circuits have been calculated and the optimum metal gate workfunction combinations of ${\Phi}_{M1}/{\Phi}_{M2}$ have been concluded in terms of power consumption, average delay, stability, energy consumption and power - delay product (PDP). In addition, we discuss and compare the CNTFET-based circuit designs of various logic gates, including ternary and binary logic. Simulation results indicate that LDDS - HMG - CNTFET circuits with ternary logic gate design have significantly better performance in comparison with other structures.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.347-353
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• 2009

The qualitative factors influencing the ingress of chloride ion into concrete are water-binder (W/B) ratio, cement type, age, chloride ion concentration of given environment, wet and dry conditions, etc. Thus, an objective of this experimental research is to investigate the effects of cement types and environmental conditions on the chloride ion diffusion characteristics in concrete through the chloride ion diffusion test. For this purpose, the diffusion coefficients for chloride ion in concrete with three types of cement such as ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC), were measured for the concrete specimens with W/B ratios of 32%, 38%, and 43%, respectively. The diffusion coefficients for chloride ion were also measured for the concrete specimens with W/B ratio of 43%, which were subjected to standard curing and field exposure conditions. It was observed from the test results that the resistance against chloride ion penetration increased with decreasing W/B ratio and those of BBC and TBC concretes were greater than that of OPC concrete. Therefore, it was revealed that the use of these cements containing mineral admixtures is required to extend the service life of RC structures exposed to chloride environment. On the other hand, it was noted that the resistance against chloride ion penetration of field exposure test specimens was slightly lower than that of standard curing test specimens due to the penetration of chloride ion under the irregular ambient temperature, splash of wave, and cycle of wet and dry.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.4
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• pp.72-85
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• 2009

This study attempts to examine the principles of landscape composition for a 'Suhwon(書院)' and the meaning and value of its traditional landscape architecture, in order to apply the results to the design of modern landscape architecture. A 'Suhwon' is a vital space containing the form and meaning of human activity. This study analyzes the characteristics of landscape composition in the construction of the Namgea Suhwon, located in Hamyang, by examining the form and meaning of its area and composition. The Namgea Suhwon was constructed with a suitable configuration and harmony in a good location, neither field nor mountain, and which encompasses transcendence and a return after passage through a period of birth and abundance. Its appearance means 'life existence and hidden death(生居死幽)'. Its spatial system is a reflection of the idea of Samshinoje(三神五帝: The three abilities of Providence and its five subjects) connected with Ilsangje -Samshin -Ohje. It was built based on the idea of Biryebudong(非禮不動) meaning that one should follow only good decorum and avoid discourtesy, complying with "the frame of decorum" developed by the family rites of Chu Hsi. The environmental design of the Namgea Suhwon was interrupted by the material confrontation between mountains and water and a binary code system, such as front to rear, length to breadth, and movement to stillness. The design did not adhere to stiff axes, but pursued the harmonic principles of asymmetric balance in the building and the yard, which are very naturalistic. The name 'Namgea Suhwon' is closely related with the view of placement(置) and harmony(和), which are unified with the function and meaning formed by connecting Sung Confucianism with the Pungsu-Sasinsa structure in the layout of the grounds. When examining the D/H ratio of the building and yard, it can be seen that the spaces of Ganghak, Yusang and Jehyang were built appropriately, according to the natural characteristics of each space, such as a sense of openness, enclosure, tension, relief, enhancement, and hierarchical order. The spaces also reflect human scale concepts that take advantage of auditory features. The transition process after the construction of 'Namgea Suhwon' reveals the intentions of the builder to create an ecological landscape composition based on Placement and Harmony. Placement embodies' a purposeful space in which nature and the building are connected naturally, 'incomplete open space pursuing completion', and 'potential beauty in which tension and relaxation are repeated'. Harmony embodies 'order and continuity having a sense of unity with the natural environment' and the 'sharing of daily life and memory'. 'Namgea Suhwon' contains many ideas for landscape planning, land use and the design of a campus environment.

• Korean Journal of Agricultural Science
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• v.20 no.2
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• pp.109-116
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• 1993

This experiment was carried out to investigate the competition in mono-and binary-associations of four forage species; ochardgrass (Dactylis glomerata L. cv. Potomac), tallfescue (Festuca arundinacea Scnreb, cv. Fawn), white clover (Trifolium repns L. cv. California), and red clover (Trifolium pratense L. cv. Kenland) as affected by different sowing rate. Each species was grown in interspecific stands in field. And samplings of shoot were taken at first cliping stages. The interspecific competition was evaluated by calculating traditional methods: aggressivity, relative yield total (RYT), relative crowding coefficient (RCC), and compensation index (CI) with shoot dry matter production and calories of nutrient ingredient of each species in mono-and binary-mixture. Compared mixture with monoculture. RYT based on dry weight was lucrative in mixture except for orchardgrass-redcover (1:0.1,1:1). RYT of calculated calories with produced nutrients was in inlucrative in mixture of orchardgrass-redclover's 1:0.1 mixture by RYT<1.0. Generally, RYT was the highest in mixture of 1:0.5 sowing rate. Aggressivity of grass was poor competition tendency that raised up legume's sowing rate, particularly, with whiteclover. In grasses, tallfescue was stronger competitor than orchardgrass with legume in mixture, RCC of grasses against legume's growth was depressed in higher sowing rate with legume. Grass's growth depression was severer with whiteclover than redclover in mixture.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.822-828
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• 1998

Binary system of water and polyoxyethylene dodecyl ether, $C_{12}H_{25}(OCH_2CH_2)nOH$, have been studied by $^1H$ NMR techniques. For n=5($C_{12}EO_5$) and n=8($C_{12}EO_8$), the self-diffusion coefficients of nonionic surfactants in the isotropic phase($L_1$) have been measured by using pulsed field gradient technique for a range of temperature and concentrations. In addition the line widths of the different proton signals have been monitored, and samples of some liquid crystalline characteristic were also studied. Dramatic Broadening of the methylene signals of the alkyl($C_{12}H_{25}$) chain is observed as the hexagonal liquid crystalline phase is approached in the $C_{12}EO_5-$water system, while only small broadening is observed in the $C_{12}EO_8-$water system. It was shown that there was a growth of $C_{12}EO_5$ micelles to rods with increasing concentrations, while the $C_{12}EO_8-$ micelles at low temperature remain small in the concentration range. The self-diffusion coefficients of the surfactants decrease rapidly with increasing concentration until a minimum is reached after which there is slow increase. The location of the minimum point occurs at lower concentrations the temperature is close to the cloud point, where the system separate into two isotropic phase. In the line width studies, broadening is found at a certain temperature interval when the concentration is increased in the $C_{12}EO_5$ system. The results indicate that the surfactant aggregates grow in size at the cloud point is approached. The aggregates seem to be flexible and probably not to be of a definite shape close to the cloud point. In the $C_{12}EO_8$ system, the micelles are much less affected by an increase in temperature and micellar growth can't be unambiguously established. The methylene signals of the ethylene oxide moieties consistantly show narrower $^1H$ signals, showing that in the aggregates they are less ordered than the chain methylenes. The various changes in aggregate size and shape are correlated with the stability ranges of the isotropic and liquid crystalline phases according to phase diagrams from the literature. Both aggregate size and phase structure are in qualitative agreement with concentration based on the effective shape of the molecules at different temperature and concentration.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.275-282
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• 2018

Miscanthus species are known as a genus of eco-friendly and low-maintenance cost ornamental grasses. Plug and cutting methods were tested for multi-propagation of most promising ornamental Miscanthus species in greenhouse and field plot. The plug formation period with three different cell sizes with four cultivars (M. sinensis 'Andersson', 'Strictus', 'Gracillimus', 'Variegatus') were evaluated the seedling development stages with two irrigation types of the over-head and the bottom watering in greenhouse and field plot afterward during 2015-2016 season. In seedling plug test, the size of tray cell affected the plug formation. Bottom irrigation resulted positively on plant height, weight, root and tiller development compared with the over-head irrigation. Plug cell size affected the plant growth in the field after transplanting. All of the 3 Miscanthus species showed higher rates of successful propagation at the lower nodes before inflorescence formation (vegetative growth stage). To analyze the survival factors of M. xgiganteus cutting, the cutting time, node part, and culm diameter were tested as independent variables with the binary logistic model. The survival probability was influenced by node part and culm diameter significantly. The third and fifth node parts showed 0.12 (8X higher failure probability) and 0.02 (50X higher failure probability) times less survival probability. It means the survival probability will be increased by using older and lower part of cuttings during a vegetative growth stage before inflorescences of M. xgiganteus.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.251-252
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• 2012

Recently, the growing interest in organic microelectronic devices including OLEDs has led to an increasing amount of research into their many potential applications in the area of flexible electronic devices based on plastic substrates. However, these organic devices require a gas barrier coating to prevent the permeation of water and oxygen because organic materials are highly susceptible to water and oxygen. In particular, high efficiency OLEDs require an extremely low Water Vapor Transition Rate (WVTR) of $1{\times}10^{-6}g/m^2$/day. The Key factor in high quality inorganic gas barrier formation for achieving the very low WVTR required ($1{\times}10^{-6}g/m^2$/day) is the suppression of defect sites and gas diffusion pathways between grain boundaries. In this study, we developed an $Al_2O_3$ nano-crystal structure single gas barrier layer using a Neutral Beam Assisted Sputtering (NBAS) process. The NBAS system is based on the conventional RF magnetron sputtering and neutral beam source. The neutral beam source consists of an electron cyclotron Resonance (ECR) plasma source and metal reflector. The Ar+ ions in the ECR plasma are accelerated in the plasma sheath between the plasma and reflector, which are then neutralized by Auger neutralization. The neutral beam energies were possible to estimate indirectly through previous experiments and binary collision model. The accelerating potential is the sum of the plasma potential and reflector bias. In previous experiments, while adjusting the reflector bias, changes in the plasma density and the plasma potential were not observed. The neutral beam energy is controlled by the metal reflector bias. The NBAS process can continuously change crystalline structures from an amorphous phase to nano-crystal phase of various grain sizes within a single inorganic thin film. These NBAS process effects can lead to the formation of a nano-crystal structure barrier layer which effectively limits gas diffusion through the pathways between grain boundaries. Our results verify the nano-crystal structure of the NBAS processed $Al_2O_3$ single gas barrier layer through dielectric constant measurement, break down field measurement, and TEM analysis. Finally, the WVTR of $Al_2O_3$ nano-crystal structure single gas barrier layer was measured to be under $5{\times}10^{-6}g/m^2$/day therefore we can confirm that NBAS processed $Al_2O_3$ nano-crystal structure single gas barrier layer is suitable for OLED application.