• 펄프종이기술
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• 제33권3호
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• pp.9-17
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• 2001

The floc characteristics of base paper stock for coating by the retention aid system consisting of polyacrylamide (high molecular weight low charge density, HMLC) and PEI without and with anionic inorganic oxide (IO) were investigated under various shear conditions of MDDA (modified dynamic drainage analyzer). The floc size was increased with cationic electrolytes dosage whatever inorganic oxide is applied or not. The effect of inorganic oxide on the floc size showed the different result between PAM and PEI. The smaller floc was obtained by PAM without inorganic oxide, but larger floc was obtained by PAM with inorganic oxide. However, the effect of shear force was not observed. Floc formation index was decreased by the addition of cationic electrolytes with or without inorganic oxide. Floc formation index had better correlation format formation index than floc size. The relationships between wet web permeability and mat air permeability showed the significant linear correlation ($R^2$=0.97~0.98) for HML PAM and PEI. Floc formation index gave more useful information than the retention measurement when the performance of retention aids is evaluated at the laboratory before applying at the paper mill.

• Geomechanics and Engineering
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• 제22권4호
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• pp.329-337
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• 2020

Polyacrylamide (PAM) possesses high water absorption capacity and a unique pH-dependent behavior that confer large potential to enhance the engineering performance of clays. In this study, calcium bentonite was treated with a nonionic PAM. Flexible-wall permeability test and the consolidation test were performed at different pH values to evaluate the effects of PAM treatment on the hydraulic and consolidation properties. Test results demonstrate that index properties are affected by the adsorbed PAM on clay surface: a decrease in specific gravity, a decrease in net zeta potential, and an increase in liquid limit are observed due to the PAM treatment. At a given pH, the compressibility of the treated clay is greater than that of the untreated clay. However, the compression indices of untreated and treated clays can be expressed as a single function of the initial void ratio, regardless of pH. Hydraulic conductivity is reduced by PAM treatment about 5 times at both neutral and alkaline pH conditions under similar void ratios, because of the reduction in size of the water flow channel by PAM expansion. However, at acidic pH, the hydraulic conductivity of the treated clay is slightly higher than the untreated clay. This reflects that the treated bentonite with PAM can be beneficially used in barrier system for highly alkaline residues.

• 펄프종이기술
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• 제45권5호
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• pp.23-29
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• 2013

Various properties of cotton handsheet were measured to solve the problem of deformation while storing guar gum(natural polymer) and to improve strength and retention by synthetic polymers(A-PAM, C-PAM, CMC). The results of this study were summarized as follow. The cotton handsheet with 0.2% of A-PAM showed the best tensile index and folding endurance. Retention of fines and fillers in pulp slurry with 0.2% and 0.3% of A-PAM were more excellent than that with guar gum.

• Journal of the Korean Data and Information Science Society
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• 제22권4호
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• pp.741-753
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• 2011

마이크로어레이 유전자 발현데이터인 효모데이터를 이용하여 군집분석을 실시하였다. 모형기반 군집방법, K-평균법, 중앙값 중심분포 (PAM), 자기 조직화 지도 (SOM), 계층적 Ward 군집방법을 이용하여 군집화를 실시하고, 연결성 측도 (connectivity), Dunn지수, 실루엣 측도 (silhouette)를 이용하여 각 군집방법에 대한 유효성을 측정하고 군집분석 결과를 비교하고자한다.

• 한국응급구조학회지
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• 제9권1호
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• pp.79-87
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• 2005

Purpose: Investigates the results of CPR operation in visited patients with arrest state, and element to affect the results, and it is checks a problem, and it is made to promote. Methods: As for this study, analysis studied the results that operation CPR with the object arrest patients of 69 visited Jecheon Seoul hospital emergency center for during the period from January 2002 to February 2005. It was played writing partly changed In-hospital Utstein Style, and to stick a record in it. Paramedic which participated in CPR directly did the record of a variable, As for the data processing, use SPSS Version 12.0 for Windows. Results: It was male 68.1% female 31.9% for 69 people, and the sex ratio didn't affect return of spontaneous circulation, with female 8 people to male 16 people for ROSC(Return of spontaneous circulation) 24 people. with female 14 people to male 31 people for NROSC(Non-return of spontaneous circulation) 45 people(p>0.05). The initial EKG rhythm was asystole 34.8%, VF 31.9%, The case that initial EKG was VF compared it to a patient of asystole, and a survivor had a lot of VF and there were a lot of survivors(p<0.05). The wasn't relativity between VF and PEA(p>0.05), The CPR lead time was short in ROSC with NROSC $25.0{\pm}15.0$ minutes, ROSC $11.9{\pm}10.7$ minutes(p<0.01). Epinephrine administer time was NROSC $3.0{\pm}4.1$ minutes, ROSC $2.1{\pm}1.9$ minutes(p>0.05). It was survivor 18 people(21.1%) than 24 hours and the PAM Index affected in ROSC. with $9.0{\pm}1.2$ points NROSC, with $1.6{\pm}1.7$ points ROSC(p<0.01). A correlation was high between a CPR lead time and PAM Index(p<0.02), a correlation was examined by being high between ROSC and a CPR lead time, PAM Index(p<0.01).

• 응용통계연구
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• 제24권6호
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• pp.1077-1094
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• 2011

마이크로어레이 유전자 발현 데이터인 yeast cdc15에 대해 시계열 데이터의 특성을 반영한 푸리에 계수를 이용한 검정통계량과 FDR 다중비교법을 이용하여 차별화된 유전자를 선별한 후 선별된 유전자들에 대해 모형기반 군집방법, K-평균법, PAM, SOM, 계층적 Ward 군집방법과 Fuzzy 군집방법을 실시하였다. 군집방법에 따른 특성을 알아보고 군집화 결과와 내부유효성 측도로 연결성 측도, Dunn 지수와 실루엣 값을 살펴본다. 또한 GO분석을 통한 생물학적 의미도 파악해본다.

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.235-239
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• 2000

A polysaccharide with antithrombin activity in Manda$^{(R)}& (PAM) was purified via procedures comprising three major steps, i.e. fractional precipitation with ethanol, anion exchange chromatography, and gel permeation chromatography. PAM showed a symmetrical peak on size exclusion HPLC, as assessed by refractive index, and behaved as a single band on cellulose acetate electrophoresis. The average molecular mass was estimated to be 222 kDa by gel filtration. PAM was found to be a sulfated heteropolysaccharide that contains sulfate group (20.5%, w/w) and uronic acid moiety (7.1 %, w/w) in addition to neutral sugar consisting of fucose, xylose, mannose, galactose, and glucose in a molar ratio of 1.00 : 0.35 : 0.28: 0.22 : 0.15. This polysaccharide appeared to inhibit blood coagulation via the intrinsic pathway in a dose-dependent pattern. The clotting of fibrinogen by thrombin was also significantly mitigated by the presence of PAM.

• 펄프종이기술
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• 제46권1호
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• pp.29-38
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• 2014

Guar gum is added to the pulp suspension at the suction side of the fan pump just before the sheet is formed on either a fourdrinier or cylinder machine. Guar gum replaced and supplements these hemicelluloses in paper bonding with many advantages, which include improved sheet formation with a more random distribution of pulp fibers. But, guar gum has serious storage problem. This material has easily decayed after High-temperature conditions such as summer. In this study, various properties of cotton handsheet were measured to solve the problem of deformation while storing guar gum and to improve the durability. After aging, which is one of the durability tests, cotton handsheet with 0.2% and 0.3% of A-PAM showed improved mechanical properties and bursting index and folding endurance of cotton handsheet with 0.3% of A-PAM were similar to those with guar gum. The yellowness loss of cotton handsheet with synthetic polymers was lower than those with guar gum.

• Journal of Power Electronics
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• 제10권5호
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• pp.477-484
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• 2010

A pulse width modulation-voltage source inverter (PWM-VSI) is used for variable speed permanent magnet synchronous motor (PMSM) drives. The PWM-VSI fed PMSM has two major disadvantages. Firstly, the PWM-VSI DC-link voltage limits the magnitude of the PMSM terminal voltage. As a result, the motor speed is restricted. Secondly, in a low speed range, the PWM-VSI modulation index declines. This is caused by a high DC-link voltage and a low terminal voltage ratio. As a result, the distortion of the voltage command and the stator current are increased. This paper proposes an optimal pulse amplitude modulation (PAM) control which can adjust the inverter DC-link voltage by using a buck-boost DC-DC converter. At a low speed range, the proposed system can reduce the distortion of the voltage command, which improves the stator current waveform. Also, the allowable speed range is extended. In order to verify the proposed method, experimental results are provided to confirm the simulation results.

• 펄프종이기술
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• 제46권1호
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• pp.39-45
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• 2014

Various approaches have been tried to reduce the emission of carbon dioxide in paper industry. One of important approaches is to use PCC manufactured from emission gas as a filler. However, it was recognized that PCC is inferior to other fillers in the paper strength properties of view. Therefore, pretreatment of PCC with pulp powder was tried to mitigate the strength reduction of paper. Pretreatment of PCC with pulp powder improved the bulk(7.4~12.9%) and air permeability(24.8~42.98%), but there is no significant change in opacity. Tensile index, burst index and stiffness were decreased by the use of pretreated PCC with pulp powder. Anionic and cationic PAM were used as a additive for PCC pretreatment in order to improve strength properties. There was no significant change in bulk in all kinds of PAM used in this study. Most strength properties were improved by the pretreatment of PCC with the anionic and cationic PAM and pulp powder, although the opacity and stiffness were more or less decreased.