• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.525-531
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• 2018

This paper proposes a bi-component dye, including the unripe fruit of Diospyros kaki THUNB and Ecklonia cava, to substitute for traditional persimmon dyeing because fabrics dyed with persimmon juice become stiffer and natural persimmon is insufficient for dyeing. This study examined the color difference and fabric stiffness depending on the ratio of Ecklonia cava for in a one-bath dye solution with Diospyros kaki THUNB and showed that 6% of Ecklonia cava in the bi-component dye was the optimum for decreasing the fabric stiffness. Based on these results, a bi-component dye constituting of 94% Diospyros kaki THUNB and 6% Ecklonia cava was prepared. The particle size was found to be smaller than both single dyes and it maintained a similar amount of Catechin to Diospyros kaki THUNB dye. Finally, cotton fabric dyed with a bi-component dye was much improved in terms of the fabric hand and the surface color was similar to that of the traditional persimmon-dyed fabric. These results could help to develop the natural persimmon dyeing industry.

• Journal of the Korean Ceramic Society
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• v.36 no.3
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• pp.319-324
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• 1999

기존의 고상 반응법에 의해 합성된 YNbO4 : Bi 형광체의 발광특성을 개선하기 위하여 B2O3 융체 첨가법으로 형광체를 합성하고, 빛발광(PL) 및 저전압 음극선발광(CL)을 측정하였다. PL 및 CL 모두 415~440 nm 영역에서 강한 청색 발광 스펙트럼을 나타냈으며, 고상 반응의 경우와 마찬가지로 Y/Nb 비율이 화학 양론상의 1:1인 경우보다 결함구조를 인위적으로 조절한 51/49나 54/46에서 최대의 발광강도를 보였다. 한편, 고상 반응에서는 125$0^{\circ}C$에서 4시간 열처리하는 것이 최대의 발광효과를 나타냈으나, B2O3융제를 첨가하고 110$0^{\circ}C$에서 열처리한 시료가 결정성이 좋고 입자의 크기 및 형태가 균일하여 PL뿐만 아니라 CL에서도 우수한 발광특성을 보였다. B2O3융제를 첨가하는 방법으로 열처리 온도를 낮추고 입자크기와 형태를 조절하여 형광체의 휘도를 개선할 수 있었다.

• Resources Recycling
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• v.21 no.5
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• pp.65-71
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• 2012

The equilibrium distribution of bismuth and lead between molten PbO-$SiO_2$ slag and bismuth phase was studied in the temperature range of $775^{\circ}C$ to $850^{\circ}C$ in a MgO crucible. The oxygen partial pressure of atmosphere was controlled by $P_{CO2}/P_{CO}$ ratio. The value of $(%PbO)_{slag}/[%Pb]_{metal}$ increased with increasing $SiO_2$ content of slag, and the value of $(%Bi_2O_3)_{slag}/[%Bi]_{metal}$ decreased with increasing $SiO_2$ content of slag. The concentration of Pb in metal increased with increasing temperature. These experimental results agreed well with the thermodynamic prediction.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.615-619
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• 2009

A real-time, continuous-scale image interpolation method is proposed based on bi-linear interpolation with directionally adaptive low-pass filtering. The proposed algorithm has been optimized for hardware implementation. The original bi-linear interpolation method has blocking artifact. The proposed algorithm solves this problem using directionally adaptive low-pass filtering. It can also solve the severely problem by selection choosing low-pass filter coefficients. Therefore the proposed interpolation algorithm can realize a high-quality image scaler for various imaging systems, such as digital camera, CCTV and digital flat panel display, to name a few.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.479-485
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• 2011

Pt-Bi/C catalysts supported on carbon black with various Pt/Bi ratios were synthesized by a reduction method. Chloroplatinic acid hydrate ($H_2PtCl_6{\cdot}xH_2O$) and bismuth (III) nitrate pentahydrate ($Bi(NO_3)_3{\cdot}5H_2O$) were used as precursors for Pt and Bi, respectively. Before loading metal on carbon, heat treatment and pretreatment of carbon black in an acidic solution was conducted to enhance the degree of dispersion. The physical property of the synthesized catalysts was investigated by X-ray diffraction and X-ray photoelectron spectroscopy. The XRD pattern of untreated Pt-Bi/C catalyst showed BiPt and $Bi_2Pt$ peaks in addition to Pt peaks. These results imply that Bi atoms were incorporated into the Pt crystal lattice by Pt-Bi alloy formation. The catalytic activity for methanol oxidation was measured using cyclic voltammetry in a mixture of 0.5 M $H_2SO_4$ and 0.5 M $CH_3OH$ aqueous solution. The addition of proper amount of Bi was found to significantly improve catalytic activity for methanol oxidation. The catalytic activity for methanol oxidation was closely related to the stability between electrode and electrolyte. In order to investigate the stability of catalysts, chronoamperometry analysis was carried out in the same solution at 0.6 V.

• Survey Research
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• v.10 no.1
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• pp.113-139
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• 2009

It is desirable to use a monthly benchmarked construction indicator which contains the characteristics of statistical data in an annual survey in order to analyze the cyclical phenomenon of the construction activity. The benchmarked indicator is expected to improve the data quality in terms of accuracy, consistency, comparability, and completeness. In this paper, benchmarking methodologies of compiling monthly construction indicators arc researched by using a monthly prompt data holding short - term fluctuations and an annual survey data regarded as more accurate statistics than monthly data. The benchmarking is the methodology by which a high frequency data should he adjusted in order to hold the short-term and cyclical phenomena, and the long - term trend of two data groups with ensuring the consistency of an annual summation between a high frequency data and a low frequency data. This paper considered the numerical approach like pro rata distribution method, proportional Denton method, EFL or HP filter Benchmark - to - Indicator ratio method, and the model - based approach such as Chow and Lin method, $Fem{\acute{a}}ndez$ method. Also, the benchmarked construction indicators were estimated by early mentioned benchmarking methods with practical data, and these methods were empirically reviewed and compared. In case of construction indicators with severe seasonal fluctuations and irregulars, the numerical approach seemed to be performed more correctly than the model- based approach. Among numerical methods, the proportional Denton method used in general was a little nice. The HP filter Benchmark - to - Indicator ratio method may be considered with survey errors or measurement errors in an annual survey data.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.103-107
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• 2021

Temperature dependences of electronic and thermal transport properties of narrow band gap thermoelectric materials are dependent on the transport behavior of minority carriers as well as majority carriers. Thus, weighted mobility ratio, which is defined the ratio of weighted mobility for majority carriers to that for minority carriers, must be one of the important parameters to enhance the performance of thermoelectric materials. Herein, we provided a practical guide for the development of high-performance Bi-Te-based thermoelectric materials based on the weighted mobility ratio control by considering theoretical backgrounds related to the electronic transport phenomena in semiconductors.

• Annual Conference on Human and Language Technology
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• 2017.10a
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• pp.71-75
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• 2017

외래어란 외국어로부터 들어와 한국어에 동화되고 한국어로서 사용되는 언어이다. 나날이 우리의 언어사용 문화에서 외래어의 사용 비율은 높아져가는 추세로, 전문분야에서는 특히 두드러진다. 그러므로 더 효율적이고 효과적인 자연언어처리를 위해서 문서 내 외래어 인식은 중요한 전처리 과정이다. 따라서 본 논문에서는 bidirectional LSTM(이하 bi-LSTM)-CRF 모형의 심층학습을 이용한 음절태깅 기반의 외래어 인식 시스템을 제안한다. 제안하는 시스템의 외래어 인식 학습 과정은 다음과 같다. 첫째, 학습용 말뭉치 자료의 한글 음절들과 공백, 마침표(.)를 토대로 word2vec을 통해 학습용 피쳐(feature) 자료를 생성한다. 둘째, 학습용 말뭉치 자료와 학습용 피쳐 자료를 결합하여 bi-LSTM 모형 학습 자료를 구축한다. 셋째, bi-LSTM 모형을 거쳐 학습된 결과물을 CRF 모형에서 로그 가능도(log likelyhood)와 비터비(Viterbi) 알고리즘을 통해 학습 결과물을 내놓는다. 넷째, 학습용 말뭉치 자료의 정답과 비교한 뒤 모형 내부의 수치들을 조정한다. 다섯째, 학습을 마칠 때까지 반복한다. 본 논문에서 제안하는 시스템을 이용하여 자체적인 뉴스 수집 자료에 대해서 높은 정확도와 재현율을 기록하였다.

• 한국어정보학회:학술대회논문집
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• 2017.10a
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• pp.71-75
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• 2017

외래어란 외국어로부터 들어와 한국어에 동화되고 한국어로서 사용되는 언어이다. 나날이 우리의 언어사용 문화에서 외래어의 사용 비율은 높아져가는 추세로, 전문분야에서는 특히 두드러진다. 그러므로 더 효율적이고 효과적인 자연언어처리를 위해서 문서 내 외래어 인식은 중요한 전처리 과정이다. 따라서 본 논문에서는 bidirectional LSTM(이하 bi-LSTM)-CRF 모형의 심층학습을 이용한 음절태깅 기반의 외래어 인식 시스템을 제안한다. 제안하는 시스템의 외래어 인식 학습 과정은 다음과 같다. 첫째, 학습용 말뭉치 자료의 한글 음절들과 공백, 마침표(.)를 토대로 word2vec을 통해 학습용 피쳐(feature) 자료를 생성한다. 둘째, 학습용 말뭉치 자료와 학습용 피쳐 자료를 결합하여 bi-LSTM 모형 학습 자료를 구축한다. 셋째, bi-LSTM 모형을 거쳐 학습된 결과물을 CRF 모형에서 로그 가능도(log likelyhood)와 비터비(Viterbi) 알고리즘을 통해 학습 결과물을 내놓는다. 넷째, 학습용 말뭉치 자료의 정답과 비교한 뒤 모형 내부의 수치들을 조정한다. 다섯째, 학습을 마칠 때까지 반복한다. 본 논문에서 제안하는 시스템을 이용하여 자체적인 뉴스 수집 자료에 대해서 높은 정확도와 재현율을 기록하였다.

• Journal of Educational Research in Mathematics
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• v.25 no.3
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• pp.431-448
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• 2015

This study is conducted to understand the real shape of confusion surrounding mathematical terminologies, 'ratio' and 'rate' in both the US and Korea and to get some implications for Korean education. For this, various materials including textbooks and materials for kids and teachers, dictionaries, educational internet web sites, the past Korean elementary mathematics curriculums and etc are reviewed with respect to the terminologies related to 'ratio' and 'rate'. As a result, the findings are as follows. Firstly, the US and Korea have different views with ratio and rate. Secondly, Korean terminologies related to ratio and rate are not enough to treat the essentials of the concept of ratio and rate.