• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.305-314
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• 1989

Effect of pH variation in starting solution for the making of hydroxyapatite powder was studied in relation to the sinterability of the powder and their mechanical properties of the sintered hydroxyapatite ceramics. The sinterability of hydroxyapatite powder prepared at different pH was found to be improved with increase in pH value of the starting solutions. Thus the powders prepared from the higher pH solutions including 10.5, 11.0 and 11.5 could be well densified almost upto theoretical density by firing for 1 hr at 1,00$0^{\circ}C$. But the powder based on pH 10 exhibited less sinterability even being fired at much higher temperature of 1,10$0^{\circ}C$, it gave only 90-95% of theoretical density. On the other hand the powder prepared on the lowest pH value 9.5 could not be well densified and it could obtain only 78% of theoretical density even by firing at 1,30$0^{\circ}C$ for 1hr. It was found that prismatic crystals of whitlockite were always included in the sintered bodies based on the lower pH values as a minority crystalline phase together with the major crystalline phase of hydroxyapatite and its inclusion might impair the sinterability of powder. However in the case of the higher pH, the powder contained only hydroxyapatite as a crystalline phase on sintering without any minorities. The sphere shape of crystals might help effectively the densification of the bodies. The best mechanical properties could be obtained from the body of pH 11 sintered at 1,10$0^{\circ}C$, which gave 99.5% of theoretical density, 662Kg/$\textrm{mm}^2$ of vickers hardness and 1,352Kg/$\textrm{cm}^2$ of diameteral compression strength.

• The KIPS Transactions:PartC
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• v.16C no.6
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• pp.773-782
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• 2009

A DHT(Distributed Hash Table) based P2P is a method to overcome disadvantages of the existing unstructured P2P method. If a DHT algorithm is used, it can do a fast data search and maintain search efficiency independent of the number of peer. The peers in the DHT method send messages periodically to keep the routing table updated. In a mobile environment, the peers in the DHT method should send messages more frequently to keep the routing table updated and reduce the failure of a request. Therefore, this results in increase of network traffic. In our previous research, we proposed a method to reduce the update load of the routing table in the existing Chord by updating it in a reactive way, but the reactive method had a disadvantage to generate more traffic than the existing Chord if the number of requests per second becomes large. In this paper, we propose an adaptive method of routing table update to reduce the network traffic. In the proposed method, we apply different routing table update method according to the number of request message per second. If the number of request message per second is smaller than some threshold, we apply the reactive method. Otherwsie, we apply the existing Chord method. We perform experiments using Chord simulator (I3) made by UC Berkeley. The experimental results show the performance improvement of the proposed method compared to the existing methods.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.56-60
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• 1974

A survey of the available methods for the determination of piperine was made, and a new method, developed based upon alkaline hydrolysis at about $140^{\circ}C$ followed by colorimetric determination of the liberated piperidine. Piperidine on treatment with p-nitrophenyl diazonium fluoborate reagent gives a red colored complex which has an adsorption maximum at 530nm. The method measures the total pungency in pepper and applicaple to piperine of black pepper and oleoresin of black pepper. The advantage of the present method is that the pungent compounds can be determined in micro samples.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.184-190
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• 1999

The use of the polymerase chain reaction (PCR) method was described using two sets of primers based on the ceuN gene (JEJ 1 and JEJ 2) which encodes a protein involved in siderophore transport and 16S rRNA gene (pA and pB) for the sensitive and specific detection of enteropathogen Campylobacter jejuni. Six oligonucleotides were utilized in an amplification experiment and PCR products of predicted sizes were generated from whole cells and boiled cell lysates at the same intensity. Two sets of the primer pairs, JEJ and pAB, were specific enough for all C. jejuni strains tested for the direct use of whole cells without DNA extraction or lysis steps. In the PCR using the pAB primer pair, the detection limit, as determined by the ethidium bromide staining of the amplification products on agarose gels, was at the level of $10^1$ bacteria cells or less in both the pure culture and artificially inoculated milk and chicken enrichment samples, whereas the detection limit with the JEJ primer pair was relatively low, i.e. $10^3$ cells or more in the same PCR samples. The PCR method using either a primer JEJ or pAB was both repeatable and specific for the detection of C. jejuni in food. This method is simply completed within 4 h.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.725-729
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• 2016

A novel genome-engineering tool in Clostridium acetobutylicum was developed based on single-crossover homologous recombination. A small-sized non-replicable plasmid, pHKO1, was designed for efficient integration into the C. acetobutylicum genome. The integrated pHKO1 plasmid backbone, which included an antibiotic resistance gene, can be excised in vivo by Flp recombinase, leaving a single flippase recognition target sequence in the middle of the targeted gene. Since the pSHL-FLP plasmid, the carrier of the Flp recombinase gene, employed the segregationally unstable pAMβ1 replicon, the plasmid was rapidly cured from the mutant C. acetobutylicum. Consequently, our method makes it easier to engineer C. acetobutylicum.

• Journal of the Korean Mathematical Society
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• v.46 no.1
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• pp.1-12
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• 2009

Motivated by XTR cryptosystem which is based on an irreducible polynomial $x^3-cx^2+c^px-1$ over $F_{p^2}$, we study polynomials of the form $F(c,x)=x^3-cx^2+c^qx-1$ over $F_{p^2}$ with $q=p^m$. In this paper, we establish a one to one correspondence between the set of such polynomials and a certain set of cubic polynomials over $F_q$. Our approach is rather theoretical and provides an efficient method to generate irreducible polynomials over $F_{p^2}$.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.60-67
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• 2018

The purpose of this study was to examine the effects of internet-use Anatomy class, as one of the Flipped learning method, on critical thinking disposition. The class for this study was conducted from March 1 to April 10, 2018. The study involved a total of 180 people in the first year of a University located in C province. Data collection was carried out before and after the Flipped learning method application. Frequency analysis, Paired t-test, Pearson correlation, and Regression analysis were used for the analysis. According to the analysis, 28.3% of men and 71.1% of women and before applying the program analysis of correlation between Flipped learning perception and critical thinking disposition showed a significant correlation between confidence(sub-component of critical thinking) only (p<.005). Comparing the scores of critical thinking before and after the program, it was found that Truth seeking (p<.001), Open-mindness (p<.005), Confidence (p<.001), Systematicity (p<.005), Analyticity (p<.001), and Inquisitiveness (p<.001) scores had increased significantly except Maturity (p>.005). And the regression analysis of Flipped learning method applying influence on critical thinking disposition were significantly affected (p<.001). Based on the results of this study, it was possible to determine that Flipped learning method had a positive effect on critical thinking disposition.

• Journal of the Korean Ceramic Society
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• v.31 no.6
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• pp.685-693
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• 1994

Sublimation vapour pressures and sublimation enthalpy of anhydrous bismuth trifluoride have been measured by the continuous gravimetric Cnudsen-effusion method from 639-7 to 782.8 K. Additional effusion measurements have also been made from 750.6 to 863.1 K by the torsion-effusion method. Based on a correlation of subHo298.15 and subSo298.15, a recommended P(T) equation has been obtained for BiF3(s); logP= -C/T+5.2375logT-3.205$\times$10-3+4.661$\times$104/T2+1.348 where P is in Pa, T in Kelvin, subHo298.15 in kJ mol-1 and C=( subHo298.15-13.5149)/1.9146$\times$10-2. Condensation coefficients and their temperature dependence have been derived from the effusion measurements.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.209-209
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• 2004

This cDNAs were cloned with the method of the polymerase chain reaction (PCR) by sequences based on cloned rat LH/CG and FSH receptor cDNAs. A cDNAs of LHR and FSHR were transfected into the CHO cells. Several clonal cell lines were obtained expressing different numbers of cell surface receptors. (omitted)

• Journal of the Korean Ceramic Society
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• v.28 no.2
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• pp.109-118
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• 1991

Steady-state sublimation vapour pressures of anhydrous bismuth triiodide have been measured by the torsion-effusion method from 488.8 to 570.5 K and equilibrium sublimation pressures were obtained from the steady-state data. The standard sublimation enthalpy changes derived by both second(modified sigma function) and third(average enthalpy method) law methods were 159.316${\pm}$0.055, 137.67${\pm}$1.43 kJ$.$mol-1 respectively. The standard sublmation entropy change derived by modified sigma function was 232.88${\pm}$0.10 J$.$K-1$.$mol-1. The reliable standard sublimation enthalpy change based on a correlation of {{{{ { TRIANGLE }`_{cr } ^{g } }} H{{{{ { 0} atop {m } }}(298.15K) and {{{{ { TRIANGLE }`_{cr } ^{g } }} S{{{{ { 0} atop {m } }}(298.15K), a recommended p(T) equation has been obtained for BiI3(cr) ; lg(p/Pa)=-(C$.$K/T)+5.071lg(T/K)-2.838${\times}$10-3(T/K)-7.758${\times}$103(K/T)2+1.4519 where C={{{{{ { TRIANGLE }`_{cr } ^{g } }} H{{{{ { 0} atop {m } }}(298.15K)/0.019146 kJ$.$mol-1}-456.27.