• Journal of the Korean Wood Science and Technology
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• v.23 no.3
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• pp.66-72
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• 1995

The rate of fixation of the components were evaluated in CCA-Type B and CCFZ-treated radiata pine sapwood by quantitative analysis of solution expressed from the treated wood. The leaching characteristics of radiata pine blocks treated with CCA-Type B and CCFZ were also evaluated by the AWPA standard leaching test. Both fixation and leaching charactersistics of CCA-Type B were compared with CCA-Type C treated wood samples. The rate of CCA-Type B fixation was a little faster than that of CCFZ. However, significant amounts of arsenic was unfixed in the CCA-Type B treated samples and consequently leached. These significant quantities of arsenic liberated from the CCA-Type B treated wood during service may pose some environmental concerns. Arsenic was no longer detectable from CCA-Type C treated samples when fixation was complete, even though the fixation of CCA-Type C was slower in some degree than CCA-Type B. In summary, it could be said that CCFZ was much safer preservative than CCA-Type B by the criterion based on the relative hazard assessed by absolute amount of unfixed element present in the treated wood. Also the decision that CCA preservative has to move from Type B to Type C should be made sooner or later for continuous use of CCA preservative in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.8
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• pp.1404-1422
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• 2011

In this paper, a new clear channel assessment (CCA) method: cascaded-CCA, is proposed. The primary motivation for the proposed approach is to integrate the respective advantages of two standard CCA mechanisms, energy detect and preamble detect, to arrive at a new dual threshold CCA family that can provide greater flexibility towards tuning MAC performance. Cascaded-CCA integrates energy efficiency of the energy detector (ED) and the reliability of the preamble detector (PD). The probability of detection/false alarm and power consumption of cascaded-CCA in the CCA modules of IEEE 802.11b are analyzed and compared with ED and PD as an example. The performance of cascaded-CCA is explored via MATLAB simulations that implement the CCA modules and medium access control (MAC) protocol for IEEE 802.11 and IEEE 802.15.4. Simulation results showed that cascaded-CCA improves the energy efficiency significantly compared to ED-only or PD-only CCA. In addition, ED, PD, and cascaded CCA are applied to a cognitive network scenario to validate the effectiveness of the proposed cascaded-CCA.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.2
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• pp.160-167
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• 2015

The purpose of this study was to investigate the correlation of Intima-Media Thickness of common carotid artery(CCA-IMT) and The Second Derivative of Photoplethysmogram Waveforms(SDPTG). 38 subjects with acute ischemic stroke were recruited from the patients admitted to Dong-Eui Medical Center from the June 2013 to January 2014. We assessed 38 patient's SDPTG data and CCA-IMT data by B Mode ultrasonography. then 38 subjects were divided into two groups by the CCA-IMT difference; CCA-IMT 〈 0.8 mm group(n=11), CCA-IMT $$\geq_-$$ 0.8 mm group(n=27). We analyzed their characteristics, risk factor, blood test result, life style by CCA-IMT difference. As a result, Age, Hypertension were significantly higher in the CCA-IMT $$\geq_-$$ 0.8 mm group then in the CCA-IMT < 0.8 mm group. Regular exercise were significantly higher in the CCA-IMT < 0.8 mm group then in the CCA-IMT $$\geq_-$$ 0.8 mm group. The result of Multiple regression analysis on the factors affecting the CCA-IMT was hypertension, total cholesterol, age. and The result of Pearson's Correlation analysis on CCA-IMT and SDPTG is that e/a ratio, SDPTG AI were respectively and significantly correlated with CCA-IMT. According to the analysis, the Relationship between CCA-IMT and SDPTG in Ischemic Stroke Patients were founded. We suggest that further investigation with larger and better controlled trials of the Relationship between CCA-IMT and SDPTG could contribute to better understand the effects of risk factors on atherosclerosis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.109-114
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• 2016

This paper relates with the performance improvement of CCA (Compact Constellation Algorithm) equalization algorithm by adding the adaptive step size control in order to the minimization of intersymbol interference and additive noise effects that is occurs in the channel for digital radio transmissionl. In general, the fixed step size was used in order to adaptation in equalizer algorithm. But in proposed algorithm, the variable step size were adapted that is proposional to the nonlinear function of error signal for equalization. In order to show the improved equalizatation performance, the output signal constellation of equalizer, residual isi, maximum distortion, MSE and SER were used, then it were compared with the present CCA algorithm. As a result of computer simulation, the adaptive step size CCA has more better performance in the every performance index compared to the fixed step size CCA after in the steay state.

• Journal of the Korean Wood Science and Technology
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• v.35 no.2
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• pp.79-84
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• 2007

Surface mold fungi growing on CCA-treated wood could be inhibited effectively by the incorporation of moldicide into treating solution. In this study, moldicides compatible with the CCA solutions from various commercial moldicides were screened, and then their optimum concentrations for controlling surface mold on CCA-treated radiata pine sapwood were examined through both the laboratory and the field trials. Among nine commercial moldicdes tested, two substituted isothiazolinones, moldicide A containing 2-n-octyl-4-isothiazoline-3-one and moldicide B containing 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one, were chemically compatible with CCA solution. The optimum concentration to be incorporated into 2% CCA treating solution was determined to be 0.001% for moldicide A and 0.003% for moldicide B.

• ALGAE
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• v.33 no.1
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• pp.85-99
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• 2018

Crustose calcareous algae (CCA) constitute one of the main reef builders on the Abrolhos Bank, Brazil. Once CCA taxonomy is locally understood, differences in growth-forms may be useful for the delimitation of taxa using characteristics such as the presence or absence of surface protuberances. Here, growth-forms were used to identify and quantify the most common CCA taxa on the shallow reefs (3-10 m) of the Abrolhos Bank to determine possible changes in the CCA community over a period of 10 years, and the ecological significance of CCA to local reefs was interpreted. The CCA assemblages were surveyed from 2006-2015 by using fixed photoquadrats at four sites in the inner (10-20 km from the mainland) and mid-shelf reefs (40-75 km from the mainland). The five most common CCA taxa were Pneophyllum conicum, the Lithophyllum kaiserii / Lithophyllum sp. complex, Melyvonnea erubescens, the Hydrolithon boergesenii / Porolithon onkodes complex and Peyssonelia sp. The overall mean CCA cover on the reefs was 20%. A comparison with a previous monitoring study in the same region indicated that the CCA cover nearly doubled from 2003-2008 to 2006-2015. This study reveals that the coral-killing species P. conicum dominated CCA flora on the shallow Abrolhos reefs in the last decade, and the local specific abundance of CCA slightly fluctuated over time and was species- and site-specific. The information obtained in this study contributes to the understanding of the ecology of the key calcifying components of the Abrolhos reefs and provides a useful baseline for exploring the responses of CCA to future environmental changes.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.60-66
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• 1995

The treatability of Japanese larch heartwood was assessed by pressure treatment of non-incised dimension material with CCA or CCFZ. The effectiveness of incising(conventional, high density, and needle incising) for improving CCA treatability on refractory Japanese larch heartwood was also investigated. Preservative retention and penetration were somewhat greater with CCFZ treatment, although those was generally poor in both preservatives. The retention gradients for both CCA and CCFZ-treated stock were essentially the same shape. Treatment of non-incised material with CCA acheived the recommended treatability for using treated wood at the regions of hazard class H2 in the Japanese Agricultural Standards. However, Japanese larch heartwood would require incising as a pretreatment for enhancing treatability, if CCA-treated larch is intended to be used at the regions of hazard class H3 and H4. As expected, incising resulted in a considerable improvement of preservative treatability, particularly penetration, and the effect of incising on the improvement of treatability was excellent at the sequence of needle incising, high density incising, and conventional incising. Among incising techniques investigated in this study, high density and needle incising enhanced CCA treatability beyond the point where it did meet a minimum requirements specified by the Japanese Agricultural Standards for using CCA-treated Japanese larch at the regions of hazard class H3 and even H4.

• Journal of Korea Foresty Energy
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• v.23 no.2
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• pp.29-33
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• 2004

This study was carried out to find out safety disposal methods of waste CCA treated wood. The heavy metals of remnant were analyzed after combustion of CCA treated wood at different temperatures. Arsenic volatilized temperature was detected. The removal rate of heavy metals by acid in the ash were examined. Through this study, we could conclude that in order to protect volatilize arsenic, combustion of CCA treated wood should be do under the $300^{\circ}C$. But when CCA treated wood combustion under $300^{\circ}C$, it's weight-loss rate was $55\%$, so land reclamation dependence will be increased. When CCA treated wood combustion at high temperature, the land reclamation dependence could be reduced, but the arsenic that volatilize into the atmosphere should be captured. When it bums with high temperature, the ash contains lots of copper and chromium, so removal of heavy metals should be conducted.

• Resources Recycling
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• v.30 no.6
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• pp.68-75
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• 2021

This study aims to investigate the manufacturing process of calcium chloride-based special cement, i.e., CCA (calcium chloro aluminate, C₁₁A₇·CaCl₂), which uses limestone, by using one type of random industrial by-product, domestic coal ash, cement kiln dust. The manufacturing process of was examined in detail, and the results suggested that the amount of CCA synthesized increased with an increase in the firing temperature. The manufacturing process of CCA was investigated at 1200℃, which was determined as the optimum firing temperature. The results showed that in general, the amount of CCA synthesized tended to increase with an increase in the firing time; however, the clinker melted when the firing time was more than 30 min, thereby suggesting that a firing time of less than 20 min would be suitable for the clinkering process. The optimal firing conditions for manufacturing CCA were obtained as follows: heating rate of 10 ℃/min, firing temperature of 1200 ℃, and holding time of 20 min. The results also suggest that manufacturing CCA will be easier when high chlorine-containing cement kiln dust is used.

• Journal of the Korea Society of Computer and Information
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• v.25 no.2
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• pp.123-131
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• 2020

The text ranking algorithm is a representative method for keyword extraction, and its importance is emphasized highly. In this paper, we compare the performance of recent research and experiments with TF-IDF, SMART, INQUERY and CCA algorithms, which are used in text ranking algorithm.. After explaining each algorithm, we compare the performance of each algorithm based on the data collected from news and Twitter. Experimental results show that all of four algorithms can extract specific words from news data equally. However, in the case of Twitter, CCA has the best performance to extract specific words, and INQUERY shows the worst performance. We also analyze the accuracy of the algorithm through six comparison metrics. The experimental results present that CCA shows the best accuracy in the news data. In case of Twitter, TF-IDF and CCA show similar performance and demonstrate good performance.