• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.85-85
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• 2011

화학적 혹은 생물학적인 방법으로 합성된 생분해성 고분자(biodegradable polymers)는 환경 문제와 인간의 생명 유지와 같은 인간 생활과 밀접한 관계가 있는 적용 분야로 인해 많은 관심을 받고 있으며, 국내 플라스틱의 폐기량만 해도 2003년을 기준으로 연간 4,000톤을 쉽게 넘고 있고 재활용되는 양은 전체의 1/3 수준이며, 나머지 2/3는 소각되거나 매립되고 있다. 폴리에스테르계 생분해성 섬유는 "미생물이 분비하는 효소로, 분해 가능한 화학합성 섬유"로서, 미생물이 분비하는 가수분해 효소에 의해 고분자 쇄가 절단, 저분자량 화합물이 돼 미생물의 체내로 흡수되며, 이것이 미생물의 체내에서 효소작용에 의해 산화탄소와 물로 분해되는 섬유로 정의된다. 생분해성 고분자 중 화학합성 고분자인 지방족 폴리에스테르계 생분해성 고분자는 특히 환경 산업으로부터 많은 관심을 받고 있으며, 이러한 결정성 폴리에스테르계 고분자의 물성은 고분자의 결정화도 뿐만 아니라, 압력, 온도 등에 의해서 변할 수 있는 결정 구조에 의해 크게 영향을 받는다. 생분해성 섬유는 실용화가 이미 시작됐고, 다용도화와 수요 확대를 위해 많은 연구소와 대학, 기업들이 연구개발을 진행하고 있으며, 향후 석유자원이 고갈된다는 것은 명백한 사실이므로 이에 따라 화석자원의 절약과 유효 이용을 위해서라도 바이오 베이스 폴리머를 주원료로 한생분해성 섬유의 개발은 매우 중요한 의미를 갖는다. 본 연구에서는 합성섬유 중에서 75%의 비중을 차지하는 폴리에스테르를 대체 가능한 고내열생분해성 폴리에스테르계 직물을 제조하여 범용 폴리에스테르와 염색온도에 대한 염색성을 고찰하였다. 염색온도($100^{\circ}C$, $110^{\circ}C$, $120^{\circ}C$, $130^{\circ}C$)별, 3종의 분산염료의 농도(0.25,0.5,1.0,2.0%o.w.f)별 Build-up성 및 균염성을 비교하였으며, 염색 시료의 견뢰도를 평가하였다.

• Journal of the Korean Chemical Society
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• v.30 no.1
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• pp.3-8
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• 1986

The investigation of the effect of solvent structure on the first-order solvolysis of cis-$[Co(en)_2ClNO_2]^+$ion has been extended to water + co-solvent mixtures where the co-solvents are glycerol, ethylene glycol, isopropyl alcohol and t-butyl alcohol. Rates of solvolysis have been evaluated by spectrophotometric method at temperature 25∼30$^{\circ}$C. The polarity of solvent has influence on the variation of rate constant. The non-linear plot of the rate constant in log scale versus $\frac{D-1}{2D+1}$ implies that change in solvent structure with composition plays an important role in determining the variation of rate constant. The linearity of the plot of the rate constant in log scale versus the Grundwald-Winstein Y factor confirms that the solvolysis is an Id-type process with considerable extension of the metal chloride bond in the transition state. In the Kivinen equation the slope of the plot of log k versus $log(H_2O)$ suggests that the solvolysis is also an Id-type process. The application of free energy cycle shows that the effect of solvent structure is greater in the transition state than in the initial state.

• Resources Recycling
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• v.4 no.4
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• pp.16-21
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• 1995

When waste t~re/~vastmz otor oil is pyrolyzed. most of them hecome gaseous produds. and thc remaining onc, whascwelght is ahout in% oi the waste Ore, is pyrolyced residue mnstly composcd oi ca~bnn black A rescsrcll was canicrl nut loutilize lhe pyralyred residue of waste tnelwuste lnotol 011 us retnin~cing agent of asphall concrete, bescd on iolelg~r lesearchrepurl. This shows thal the properlies ol asphall concrele ~nclud~cd~ugl ah~l~tyre, sistance to Tear. temperature-v~scusilysusceptil,ilily u e g reatly improved when lhe pellellrcd hrln aI carlmn hlack usmg petroleum o ~als a hinder Iar ihe pellels isused with asphalt. The surface of the pyralyred resirh~ei s covned by ocl film and thla lnakes good comllatibllity with asphallIn order lo ulilk pyrolyzed residue as a reinforcing agenl oi lhe itsphalt concrete, various tests such as Marshnll tcsi, wheeltracking, and revelhng test has been carried out a1 KLER, Ko~ea I-lighway Coo~poration, and TCMO. Tcst lcsults satirry KSslandard, show "npmvements an the dynam~cs tab~l~lzym, d incrcase reslslance to wear at cold telnpelatule Invrsligadon wascarlied oul to sludg the possibility of soil pallul~on when pyrolyzed residue is used as a tzmioicing agenl. E~pcrimentalresulls show the rcsidue contained in thc asphall docs not cause cnv~ranma~lparlo blems.e cnv~ranma~lparlo blems.

• International Area Studies Review
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• v.21 no.4
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• pp.159-172
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• 2017

In a typical trend-cycle decomposition of GDP, the trend component is usually assumed to follow a random walk process. This paper considers an ARIMA trend and assesses the validity of the ARIMA trend model. I construct univariate and bivariate unobserved-components(UC) models, allowing the ARIMA trend. Estimation results using U.S. data are favorable to the ARIMA trend models. I, also, compare the forecasting performance of the UC models. Dynamic pseudo-out-of-sample forecasting exercises are implemented with recursive estimations. I find that the bivariate model outperforms the univariate model, the smoothed estimates of trend and cycle components deliver smaller forecasting errors compared to the filtered estimates, and, most importantly, allowing for the ARIMA trend can lead to statistically significant gains in forecast accuracy, providing support for the ARIMA trend model. It is worthy of notice that trend shocks play the main source of the output fluctuation if the ARIMA trend is allowed in the UC model.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.3
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• pp.159-167
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• 2021

The need for biodegradable plastic continues to increase, improvement of physical properties is necessary for actual use in the market. In this study, composite film was produced by adding peroxide additives to bioplastic according to concentration to investigate changes in the melt index, elongation, morphology, and TGA of the composite film. The addition of peroxide compatibilizer showed superior elongation of film and TGA compared to those of control. The added amount of compatibilizer affected the extrusion process, and it was revealed that adding an appropriate amount of peroxidizer is important. Analysis of the composite film's morphology revealed a heterogeneous dispersion sequence due to different rates of crystallization depending on the resin, and surface physical properties were best in the group added with 4% peroxide. The results above showed that the test group added with 4% peroxide compatibilizer was superior in the production of composite biodegradable film.

• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.51-56
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• 2023

Composite membranes consisting of TiO₂ nanoparticles (NPs) and porous polymers have been widely utilized in photocatalytic water treatment because the composite membranes can allow an easy recovery of NPs after the photocatalytic reaction as well as the reduction of fouling in the membrane. However, the photocatalytic efficiency of the immobilized TiO₂ NPs in the composite membranes has been discussed to a limited degree. In this study, we prepared polyethersulfone (PES)/TiO₂ composite membranes to study the photocatalytic decomposition of organic dyes under light illumination. The decomposition kinetics of dye molecules by the PES/TiO₂ composite membranes and colloidal TiO₂ NPs have been compared to discuss the photocatalytic efficiency of NPs before and after their immobilization on the polymer membrane.

• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.559-570
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• 2003

In this paper, we investigate a problem with Web-based learing contents and introduce the solving method of the problem. To be more accurate, existing Web-based learning contents were one fixd and uniformed courseware file with a large size and HTML format. Also, They were written files with authoring tools of which depended upon providing a multimedia vender. These learning contents were difficult to reuse among cyber education systems and change the applicable contents to the learner for learning experiences in time. So in this paper, we produced reusable and interopreable learning contents among instruction designers and education systems. They were deconstructed into smaller chunks and added to its properties. For the purpose of this producing method, we used the pedagogical designs for units of reuse. These are just turorial link-more and tell-more and was implemented with CBD method. As a result, The problem of existing Web-based learning contents system was resolved and then the power of understanding about objectified learning content was increased for the learner and instruction designers.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.401-412
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• 2011

This study uses a vector error correction model to analyze the daily time series data of the spot price of EUA (European Union Allowance). As endogenous variables, five variables are considered for the analysis, including prices of crude oil, natural gas, electricity and coal in addition to carbon price. Data period is Phase 2 period (April 21, 2008 to March 31, 2010) to avoid Phase 1 period (2005-2007) where the EUA prices were distorted. Unit-root and cointegration test results reveal that all variables have a unit root and cointegration vectors exist, so a vector error correction model is adopted instead of a vector autoregressive model.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.99-108
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• 2020

Although the relationship between income and income inequality has previously been discussed, the present study applies a dynamic approach to analyze the specific relationship between forest household income and income inequality. For this analysis, a unit root test and a cointegration test were conducted to characterize the nature of income time-series data. After converting unstable time-series data into stable time-series data, a VAR model was estimated. Based on this model, an impulse-response was generated and variance-decomposition analysis was performed. These analyses showed that the effect of forest household income was relatively larger than that of the Gini coefficient, and that the impact of forest household income not only caused income to increase but also caused the Gini coefficient to decrease. In addition, the impact of the Gini coefficient had an impact on reducing forest household income and further increasing income inequality. We conclude that, with the aim of alleviating the inequality of forest household income, an income growth policy would be more effective than an income distribution policy.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.1
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• pp.160-170
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• 2010

This paper proposes a Haar Wavelet Feature Detector (HWFD) based on the Haar wavelet transform and average box filter. By decomposing the original image using the Haar wavelet transform, the proposed detector obtains the variance information of the image, making it possible to extract more distinctive features from the original image. For detection of interest points that represent the regions whose variance is the highest among their neighbor regions, we apply the average box filter to evaluate the local variance information and use the integral image technique for fast computation. Due to utilization of the Haar wavelet transform and the average box filter, the proposed detector is robust to illumination change, scale change, and rotation of the image. Experimental results show that even though the proposed method detects fewer interest points, it achieves higher repeatability, higher efficiency and higher matching accuracy compared with the DoG detector and Harris corner detector.