• Journal of Surface Science and Engineering
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• v.45 no.6
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• pp.248-256
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• 2012

A Pd-based hydrogen membranes for hydrogen purification and separation need high hydrogen perm-selectivity. The surface roughness of the support is important to coat the pinholes free and thin-film membrane over it. Also, The pinholes drastically decreased the hydrogen perm-selectivity of the Pd-based composite membrane. In order to remove the pinholes, we introduced various surface pre-treatment such as alumina powder packing, nickel electro-plating and micro-polishing pre-treatment. Especially, the micro-polishing pretreatment was very effective in roughness leveling off the surface of the porous nickel support, and it almost completely plugged the pores. Fine Ni particles filled surface pinholes with could form open structure at the interface of Pd alloy coating and Ni support by their diffusion to the membrane and resintering. In this study, a $4{\mu}m$ surface pore-free Pd-Cu-Ni ternary alloy membrane on a porous nickel substrate was successfully prepared by micro-polishing, high temperature sputtering and Cu-reflow process. And $H_2$ permeation and $N_2$ leak tests showed that the Pd-Cu-Ni ternary alloy hydrogen membrane achieved both high permeability of $13.2ml{\cdot}cm^{-2}{\cdot}min^{-1}{\cdot}atm^{-1}$ permation flux and infinite selectivity.

• Journal of Korean Elementary Science Education
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• v.27 no.3
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• pp.273-286
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• 2008

The purpose of this study was to develop an instrument for assessing the attitude and the knowledge level of elementary school in-service and pre-service teachers' on the modem environmental issues, and to implement it. The results of this study could be summarized as following. First, the instrument for attitude was developed as a Likert-type scale, it was constituted of 30 items through the item-chosen processes to improve the validity and reliability. The Cronbach's Alpha coefficient of the attitude instrument was .899. Second, The instrument for knowledge was developed as a multiple-choice form with 와 distracts, and the final version was constituted of 35 items. The average discrimination, difficulty, and Cronbach's Alpha coefficient of the items were .367, .629, .899, respectively. Third, in-service elementary teachers have been thinking about the modern environmental problems more seriously than pre-service teachers. However, in-service teachers 'knowledge level was lower than pre-service teachers'. Fourth, women have been thinking about the modern environmental problems more seriously than men. However, there was no difference significantly between men and women on knowledge level. Fifth, This process of developing the instrument could be provided as a model for future research which will try to develop instruments for assessing attitude or knowledge of any new areas with constructs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.907-912
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• 2006

Pre-emphasizing the speech compensates for falloff at high frequencies. The most common form of pre-emphasis is y(n)=s(n)-A${\cdot}$s(n-1), where A typically lies between 0.9 and 1.0 in voiced signal. And, this value reflects the degree of pre-emphasis and equals R(1)/R(0) in conventional method. This paper proposes a new flattening method to compensate the weaked high frequency components that occur by vocal cord characteristic. We used QMF(Quardrature Mirror Filter) to minimize the output signal distortion. After using the QMF to compensate high frequency components, flattening process is followed by R(1)/R(0) at each frame. Experimental results show that the proposed method flattened the weaked high frequency components effectively than auto correlation method. Therefore, the flattening algorithm will apply in speech signal processing like speech recognition, speech analysis and synthesis.

• Geomechanics and Engineering
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• v.24 no.6
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• pp.573-588
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• 2021

The interaction of cracks and water significantly affects the fracture mechanism of rocks. In this study, laboratory tests were conducted using sandstone samples containing a single fissure to explore the hydro-mechanical behaviors in the failure process of pre-cracked rocks. The internal crack characteristics were also analyzed using X-ray CT scanning. The results show that the confining pressure has the greatest effect on the mechanical properties (e.g., strengths, elastic modulus, and Poisson's ratio), followed by the fissure inclination and water pressure. At a lower fissure inclination, the confining pressure may control the type main cracks that form, and an increase in the water pressure increases the number of anti-wing cracks and the length of wing cracks and branch cracks. However, the fracture behaviors of samples with a higher fissure inclination are only slightly affected by the confining pressures and water pressures. The effect of fissure inclination on the internal crack area is reduced with the propagation from the fissure tips to the sample ends. The fissure inclination mainly affects the value of permeability but not affect the trend. The impact of pre-existing fissure on permeability is smaller than that of confining pressure and water pressure.

• Journal of the Korea Society of Computer and Information
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• v.28 no.9
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• pp.35-46
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• 2023

In this study, we propose a Dual Approach methodology to enhance the accuracy of document classifiers by utilizing both contextual and keyword information. Firstly, contextual information is extracted using Google's BERT, a pre-trained language model known for its outstanding performance in various natural language understanding tasks. Specifically, we employ KoBERT, a pre-trained model on the Korean corpus, to extract contextual information in the form of the CLS token. Secondly, keyword information is generated for each document by encoding the set of keywords into a single vector using an Autoencoder. We applied the proposed approach to 40,130 documents related to healthcare and medicine from the National R&D Projects database of the National Science and Technology Information Service (NTIS). The experimental results demonstrate that the proposed methodology outperforms existing methods that rely solely on document or word information in terms of accuracy for document classification.

• Journal of Dental Anesthesia and Pain Medicine
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• v.24 no.2
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• pp.91-99
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• 2024

Background: Palatal injections are often painful. We aimed to compare topical ice and 20% benzocaine gel for pre-injection anesthesia before greater palatine nerve block (GPNB) injections. Methods: A randomized split-mouth clinical trial was conducted among patients aged 15-60-years needing bilateral GPNB injections. A total of 120 palatal sites from 60 patients were randomly allocated to Group A (topical ice) or Group B (20% benzocaine gel). Pain was evaluated using sound, eye, motor (SEM), and the visual analog scale (VAS) in both groups. Inferential analysis was performed using the Mann-Whitney U test. Results: The mean age of the participants was 20.5 ± 3.9 years. The median VAS score for group A was 11 (Q1 - Q3: 5.25 - 21.75), which was slightly higher than the 10 (Q1 - Q3: 4.0 - 26.75) reported in group B. However, the difference was not statistically significant (P = 0.955). The median SEM score for group A and group B was 3.5 (Q1 - Q3: 3.0 - 4.0) and 4.0 (Q1 - Q3: 3.0 - 4.0), respectively, which was statistically insignificant (P = 0.869). Conclusion: Using ice as a form of topical anesthetic for achieving pre-injection anesthesia before GPNB was as effective as 20% benzocaine gel.

• Journal of Platform Technology
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• v.12 no.1
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• pp.151-163
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• 2024

The Privacy Impact Assessment, PIPA in Korea refers to the process of analyzing risk factors and identifying improvements that must be carried out by organizations that operate personal information files as stipulated in Article 33 of the Personal Information Protection Act, PIPA and Article 35 of the Enforcement Decree of the PIPA. There are two main limitations of the PIA in Korea. The first limitation is that the targets of the PIA are limited to public institutions and organizations that are legally equivalent to public institutions, and the second limitation is that only organizations with adequate manpower, facilities, and other necessary requirements which are regulated upon the Enforcement Decree of the PIPA can conduct a PIA. This paper proposes to develop a preliminary diagnostic tool that can be performed by private companies, small and medium-sized venture companies, and small businesses in the era of rapidly developing data in recent years and presents an analysis of specific assessment factors. The results of this study are provided in the form of a self-checklist, which is expected to serve as a pre-diagnostic tool for the PIA that can be easily accessed by the general public. It is also expected to contribute to strengthening privacy protection and achieving legal compliance at the national level.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.483-492
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• 2020

Considering the fact that many students and parents spend a considerable amount of time and economic power on prior learning and that the environments of internet-based society change rapidly, it is worth examining the status and effectiveness of prior learning. In response, the study surveyed 186 first-year students of A high school in Changwon on the basic status of science prior learning. By the analysis results for the status, 39.8% of the students surveyed said they had experience in prior learning in science. Among the students experienced, 56 students who started science prior learning after the start of winter vacation in the third grade of middle school were analyzed the specific status of science prior learning and the impact of science prior learning on science achievements. The semi-subject form of pre-learning in science showed the highest response rate with 50.0 percent, and the motivation for pre-learning in science was the highest with 33.9 percent improvement in test scores. The confidence and learning intention were positive when conducting prior learning in a semi-subject form, and interest and value were positive when conducting prior learning in a self-directed form. As a result of the survey on the effect of science prior learning, 71.4% of the students who experienced science prior learning showed positive scientific achievement.

• Journal of Families and Better Life
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• v.25 no.6
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• pp.95-109
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• 2007

The purpose of this research was to evaluate the effect of ceramic activities on elderly depression and life satisfaction. The research design was based on one group, with a pre and post-test study design. The subjects of this study included twelve elderly from anelderly daytime care center in Yang-san. Instruments used in this research were KGDS (Korea Form of Geriatric Depression Scale) developed by Jung et al., and a form of life satisfaction developed by Youn. A one-hour ceramic activity was offered to participants weekly, for five weeks. The results showed that depression and life satisfaction changed after the ceramic activities. The participants produced results of emotional aspects for demented old people. More specifically and significantly, positive emotions such as pleasure, in-terest, and tranquility were increased, while negative emotions such as anger or depression were significantly decreased through the ceramic activities. Thus, this study's ceramic activities program appeared to have beneficial effects on elderly depression and life satisfaction.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.869-881
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• 1999

Inchon International Airport Elevated Road Way is located between the Passenger Terminal Building and Transportaion Center which are Inchon International Airport core construction projects. The deck of the bridge is consists of 5-span or 6-span continuous pre-stressed concrete slab. Steel form has been used to enhance the quality of texture on concrete slab. Steel form has been used to enhance the quality of texture on concrete surface, lower surface of deck slab with the two way arch has been manufactured by highly professional manner in order to get an beautiful exterior architectural looks. The prestressed concrete deck slab is mass concrete structures with a high-specified concrete strength and a varying section in the range of 0.95-2.8m thickness. Therefore high risks of thermal cracking occurrence by heat of hydration highly are expected. To resolve such problem, we adopted type 1 cement and pipe cooking method at construction site through mass concrete specimen test and 3-dimensional analysis. For Pipe cooling we used 25mm diameter stainless pipes with wrinkles. Cooling pipe with spacing 50-60cm has been installed. And continuous pipe cooling with cooling water of 15$^{\circ}C$ was conducted for 2days. In present 8 span of all 29 spans construction has been completed. No thermal cracking heat hydration has been observed yet.