• The Journal of the Convergence on Culture Technology
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• v.6 no.1
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• pp.279-288
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• 2020

In this paper, we try to criticize a bias that liberal arts are not practical. First, I introduce holistic models of knowledge and constructivism in education. Second, I suggest 'linguistic turn' as another noticeable phenomenon. Language is an element of culture, but a priviledged one because culture, in itself, is linguistic. So culture is a sort of a text. We can see that liberal arts or humanities to deal with texts, contexts and languages can have an important role to read, understand and construct a world. So the rediscovery of the traditional model of the education of liberal arts like processes of graduating studies of liberal arts or humanities, is relevant to a new 'practical' model of reading and leading recent social transformations. An important point is academic contribution. And current situation called 'Knowledge-Based Society' also supports my point in another way. The situation of rapidly changing knowledge requires an education of problem-solving ability by unifying and reconstructing knowledge supporting with constructivism in education rather than the cramming system of education.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.8
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• pp.1-8
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• 2004

Experimental results are presented for gate oxide degradation, such as SILC and soft breakdown, and its effect on device parameters under negative and positive bias stress conditions using n-MOSFET's with 3 nm gate oxide. The degradation mechanisms are highly dependent on stress conditions. For negative gate voltage, both interface and oxide bulk traps are found to dominate the reliability of gate oxide. However, for positive gate voltage, the degradation becomes dominated mainly by interface trap. It was also found the trap generation in the gate oxide film is related to the breakage of Si-H bonds through the deuterium anneal and additional hydrogen anneal experiments. Statistical parameter variations as well as the “OFF” leakage current depend on both electron- and hole-trapping. Our results therefore show that Si or O bond breakage by tunneling electron and hole can be another origin of the investigated gate oxide degradation. This plausible physical explanation is based on both Anode-Hole Injection and Hydrogen-Released model.

• Journal of the Korean Ceramic Society
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• v.43 no.11 s.294
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• pp.715-723
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• 2006

Perovskite oxide materials are very important for the electronics industry, because they exhibit promising properties. With an interest in the obvious applications, significant effort has been invested in the growth of highly crystalline epitaxial perovskite oxide thin films in our laboratory. And the desired structure of films was formed to achieve excellent properties. $Y_1Ba_2Cu_3O_{7-x}$ (YBCO) superconducting thin films were simultaneously deposited on both sides of 3 inch wafer by inverted cylindrical sputtering. Values of microwave surface resistance R$_2$ (75 K, 145 GHz, 0 T) smaller than 100 m$\Omega$ were reached over the whole area of YBCO thin films by pre-seeded a self-template layer. For implementation of voltage tunable high-quality varactor, A tri-layer structured SrTiO$_3$ (STO) thin films with different tetragonal distortion degree was prepared in order to simultaneously achieve a large relative capacitance change and a small dielectric loss. Highly a-axis textured $Ba_{0.65}Sr_{0.35}TiO_3$ (BST65/35) thin films was grown on Pt/Ti/SiO$_2$/Si substrate for monolithic bolometers by introducing $Ba_{0.65}Sr_{0.35}RuO_3$ (BSR65/35) thin films as buffer layer. With the buffer layer, the leakage current density of BST65/35 thin films were greatly reduced, and the pyroelectric coefficient of $7.6\times10_{-7}$ C $cm^{-2}$ $K^{-1}$ was achieved at 6 V/$\mu$m bias and room temperature.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.3
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• pp.267-276
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• 2020

Manufacturing workers are easily exposed to the risk of musculoskeletal disorders caused by repetitive tasks in their working environment. This is due to problems with occupational characteristics that repeatedly use the body. However, the current lack of monitoring systems for monitoring and prevention has led to an increase in workers' exposure to risks each year. This paper presents how to solve these problems in real working environment by producing wearable devices using IMU sensors. After wearing a wearable type device, the user's movement is judged through data analysis by receiving the rotation value according to musculoskeletal movement. At this time, the risk is determined by measuring the number of rotations of the user by eliminating bias and eliminating cumulative error, acquiring sophisticated data, and analyzing it in the form of dynamic threshold values. Using the wearable device proposed in this paper, the effect of this method could be checked through a web page measuring the number of rotations for elbow musculoskeletal disorders.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.215-220
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• 2002

In this paper, the 100 watt unit ower amplifier using temperature independent biasing for DTV (Digital Television) repeater application is designed and fabricated. The DC operation point of this unit power amplifier at temperature variation from $20^{\circ}C$ to $100^{\circ}C$ is fixed by active bias circuit. The variation of current consumption in the 100 watt unit power amplifier has an excellent characteristics of less than 0.6A. The implemented unit power amplifier has the gain over 12dB, the gain flatness of less than 0.5dB and input and output return, loss of than 15dB over the DTV repeater frequency range (470~806MHz). This unit power amplifier yields intermodulation distortion(IMD) of more than 32dBc at 2MHz offset, which satisfies the IMD at output power of 100 watt (50dBm).

• Journal of Surface Science and Engineering
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• v.52 no.6
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• pp.298-305
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• 2019

We investigated a correlation between morphology and photoelectrochemical properties of TiO₂ nanotubes fabricated by well-controlled anodization processes. Anodization in an ethylene-glycol-based electrolyte solution accelerated the rapid grow rate of TiO₂ nanotubes, but also cause problems such as delamination at the interface between TiO₂ nanotubes and a Ti substrate, and debris on the top of the nanotube. The applied voltages for the anodization of TiO₂ were adjusted to avoid the interface delamination. The heat treatment and the anodizing time were also controlled to enhance the crystallinity of the as-prepared TiO₂ nanotubes and to increase the surface area with the varied length of the anodized TiO₂ nanotubes. Additionally, a 2-step anodization process was utilized to remove the debris on the tube top. The photoelectrochemical properties of TiO₂ nanotubes prepared with the carefully tailored conditions were investigated. By removing the debris on TiO₂ nanotubes, applied bias photon-to-current efficiency (ABPE) of TiO₂ nanotubes increased up to 0.33%.

• Journal of Korean society of Dental Hygiene
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• v.20 no.3
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• pp.269-279
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• 2020

Objectives: Previous studies have reported inconsistent findings in the association between dental diagnostic X-ray exposure and thyroid cancer. This study was a meta-analysis of case-control studies evaluating the association between exposure to dental radiation and the thyroid cancer risk. Methods: We searched the PubMed and EMBASE databases to identify studies on dental radiation and thyroid cancer risks that were published up to September 2018. Quality of studies was assessed using the Newcastle-Ottawa scale. A fixed-effects model was used to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs) using STATA 14.0. Potential publication biases were evaluated using Egger's test and Begg's funnel plot. Results: From the literature search, we included six case-control studies in this meta-analysis. The meta-analysis using the fixed-effects model found that dental X-ray exposure was associated with 2.34 times increased risk for thyroid cancer (OR=2.34, 95% CI=1.79-3.21). There was no heterogeneity in the data (p=0.662, I² =0%). Egger's test showed that there was no publication bias (p=0.532). Conclusions: This meta-analysis confirmed the association of dental X-ray exposure and thyroid cancer risk. The current results underscore the importance of applying safety regulations at dental clinics to protect thyroid glands during dental radiography examinations.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.97-106
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• 2006

Site index is an essential tool to estimate forest productivity. Generally, a site index equation is developed and used from the relationship between stand age and dominant tree heights. However, there is a limit to the use of the site index equation in the application of variable ages, environmental influence, and estimation of site index for the unstocked forest. Therefore, it has been attempted to develop a new site index equation based on various environmental factors including site, climate, and topographical variables. This study was conducted to develop a site index equation based on the relationship between site index and environmental factors for the species of Pinus koraiensis in Yangpyung-Gun, Gyunggi Province. The influence of climatic factors (temperature and solar irradiation ratio), topographical factors (elevation, slope, ratio of slope to valley and aspect) and soil profiles (soil depth by layer and soil consistency) on site index were evaluated by multiple regression analysis. Five environmental factors were selected in the final site index equation for Pinus koraiensis. The site index equation developed in this study was also verified by three evaluation statistics: model's estimation bias, model's precision, and mean square error of measurement. Based on the site index equation, the number of productive areas for Pinus koraiensis were estimated by applying GIS technique to digitized forest maps. In addition, the distribution of productive areas was compared with the areas of current distribution of Pinus koraiensis. It is expected that the results obtained in this study could provide valuable information about the amount and distribution of productive areas for Pinus koraiensis reforestation.

• Journal of Surface Science and Engineering
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• v.49 no.3
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• pp.307-315
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• 2016

The properties of AlTiN films by a cathodic arc deposition process have been studied. Oblique angle deposition has been applied to deposit AlTiN films. AlTiN films have been deposited on stainless steel (SUS304) and cemented carbide (WC) at a substrate temperature of $500^{\circ}C$. AlTiN films were analyzed by scanning electron microscopy, glow-discharge light spectroscopy, micro-vickers hardness, and nanoindenter. When applying a current of 50 A to the cathodic arc source, it showed that the density of macroparticle of AlTiN films was 5 lower than other deposition conditions. With the increase of the bias voltage applied to the substrate up to -150 V, the density of macroparticle was decreased. The change of the $N_2$ flow rate during coating process made no influence on the film properties. For the multi-layered films, the film prepared at oblique angle of $60^{\circ}$ showed the highest hardness of 28 GPa and $H^3/E^2$ index of 0.18. AlTiN films have been shown a good oxidation resistance up to $800^{\circ}C$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1379-1385
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• 2009

We propose a low-power and high-speed client receiver for a mobile display digital interface (MDDI) newly in this paper. The low-power receiver is designed such that bias currents, sink and source currents, are insensitive to variations of power supply, process, temperature, and common-mode input voltage (VCM) and is able to operate at a rate of 450Mbps or above under the conditions of a power supply range of 3.0 to 3.6Vand a temperature range of -40 to 85$^{\circ}$C. And it is confirmed by a simulation result that the current dissipation is less than 500${\mu}$A. A test chip is manufactured with the Magna chip 0.35${\mu}$m CMOS process. When a test was done, the data receiver and data recovery circuits are functioning normally.