• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.474-477
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• 2010

최근 디지털 장비의 발전에 발맞추어 고속, 고화질의 컬러 문서가 요구됨에 따라 레이저 프린터의 보급 또한 급속도로 성장하고 있는 실정이다. 토너는 고속, 고화질의 컬러 문서 인쇄에 가장 중요한 역할을 하는 것으로, 크게 분쇄법과 중합법에 의해 제조 되고 있다. 그러나 그 중 분쇄법 토너는 근본적으로 해결되지 않는 문제점들이 있다. 즉, 중합된 수지를 사용함으로 인한 단가상승과 수지와 내첨제를 용융혼합하는 과정에서의 분산의 한계성, 그리고 인쇄 품질의 좋지 않은 것이 그 대표적인 예이다. 이에 본 실험에서는 고속, 고화질의 컬러 프린터에 적합한 중합법에 의한 토너 제조시 하이드록시아파타이트가 토너 제조에 미치는 영향에 대해서 연구하였다. Ca/P의 몰비에 따라 제조된 하이드록시아파타이트가 토너의 입자형성에 크게 영향을 주었으며, 이에 따라 토너의 물성에도 영향을 주는 것으로 나타났다. 또한 pH에 따라서도 토너중합에 많은 영향을 주는 것으로 나타났다. 토너 입자 형성에 적절한 Ca/P의 몰비 및 pH가 존재 하며, 이를 최적으로 조절하면 양질의 토너를 제조 할 수 있을 것으로 판단된다.

• Journal of Life Science
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• v.17 no.12
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• pp.1616-1621
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• 2007

Off-flavors and odors in fermented cucumbers result from the growth of undesirable microorganisms during the secondary fermentation. Under laboratory conditions using a sterile fermented cucumber slurry medium, the spoilage fermentations were reproduced. Using this system the salt and pH conditions that allow the spoilage to occur were determined by varying the NaCl concentration and pH of the slurry medium. At pH 3, no spoilage was observed, regardless of the salt concentration, while at pH 3.5, pH 4, and pH 4.5, spoilage occurred in the 0 and 2% NaCl samples. For pH 5.0 samples, spoilage products were seen for all NaCl treatments. Based on these results the Preservation Prediction Chart was developed. The Chart may be used for selection of proper pH value and salt concentration for long term storage of fermented cucumber.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.183-191
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• 2010

In this study, we isolated 179 bacterial strains using benzene, phenol, ethylbenzene, aniline, cumene, toluene as growth substrate from TCE contaminated soils and wastewaters. All the 179 strains were screened for TCE (30 mg/L) removal (growth substrate 0.2 g/L, $30^{\circ}C$, pH 7, cell biomass 1.0 g/L (w/v)) under aerobic condition for 21 days. EK2 strain using aniline showed the highest removal efficiency (74.4%) for TCE degradation. This strain was identified as Delftia acidovorans as the results of API kit, 16S rDNA sequence and fatty acid assay. In the batch culture, D. acidovorans EK2 showed the bio-degradation for TCE in the various TCE concentration (10 mg/L to 200 mg/L). However, D. acidovorans EK2 did not show the bio-degradation in the TCE 250 mg/L. D. acidovorans EK2 also show the removal efficiency (99.9%) for 12 days in the low concentration (1.0 mg/L). Optimal conditions to degrade TCE 200 mg/L were cell biomass 1.0 g/L (w/v), aniline 0.5 g/L, pH 7 and $30^{\circ}C$. Removal efficiency and removal rate by D. acidovorans EK2 strain was 71.0% and 94.7 nmol/h for 21 days under optimal conditions. Conclusion, we expect that D. acidovorans EK2 may contribute on the biological treatment in the contaminated soil or industrio us wastewater.

• KSBB Journal
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• v.11 no.6
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• pp.649-653
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• 1996

Imnmobilization characteristics of Thiobacillus sp. IW which oxidizes sulfur compound was studied to use the bacterium in odor controlling equipment for the future. The optimum growth conditions for Thiobacillus sp. IW were pH7, $30^{\circ}C$ and the generation time was 38min, which was extremely fast compared with other sulfur oxidizing bacteria. Optimum growth conditions in activated carbon as a carrier was pH5, $35^{\circ}C$ and those in bioceramics was pH 7∼8, $35^{\circ}C$. Cell growth immobilized in bioceramics was more stable in pH, temperature change than that immobilized in activated carbon and total number of cells in bioceramics were also higher. Based on these results, the bioceramics is thought to be better carrier in immobilization of Thiobacillus sp. IW.

• ICROS
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• v.3 no.5
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• pp.58-64
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• 1997

pH 공정은 비선형이며, 입력흐름의 성분과 농도가 바뀜에 따라 비선형성이 급격히 바뀌는 적응제어가 요구되는 공정이다. 최근 이 공정에 대한 모델링 기법이 확립되고, 매우 작은 수의 변수를 갖는 parameterization이 제안되어 간단한 형태의 우수한 적응제어법이 구성되어 있다. 그러나 estimation의 windup은 선형 시스템의 적응제어법에서와 마찬가지로 큰 문제점으로 남아있다. 본 고에서는 pH 공정의 적응제어법을 간략히 살펴보았으며 좀 더 견실하고 우수한 성능을 주는 방법을 위하여 두 가지 제안을 하였다. 한 제안은 기존의 변수 estimation의 목적함수가 제어기 성능에 직접적이지 못한 것을 바로 잡으려는 것이다. 새로 제안한 것을 적응제어에 바로 이용하는데 아직 걸림돌이 몇몇 남아 있어 연구가 요구되고 있다. 또 한 제안은 estimation windup을 해결하려는 것으로 pH 공정 특성상 나타나는 것으로 바로 pH 공정 적응제어에 이용될 수 있다.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.33-38
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• 1983

As flocculent strains are likely to have considerable potential for internal cell recycle, kinetic studies on glucose medium with flocculent Saccharomyces uvarum were carried out in batch and continuous culture. Using a mathematical model, the kinetic parameters at each temperature and pH were estimated in order to establish optimal conditions. It was found that an overall optimum temperature for growth and ethanol production in the range 33-35$^{\circ}C$ was desirable. With regard to the effect of pH, ethanol production by S. uvarum was found to be relatively insensitive to pH value between 4 and 6, with an optimum pH of around 5. At these optimal conditions a maximum ethanol productivity of 12 g/$\ell$/h was determined using semi-batch process together with 5. uvarum.

• Journal of the Korean Chemical Society
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• v.11 no.4
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• pp.179-184
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• 1967

The polarograms of Cd(II) in 0.15M tartrate solution were investigated in the range of pH values from 6.0 to 12.6 at 20$^{\circ}and 25$^{\circ}C. Up to pH value of 7.8, the limiting current and the halfwave potential were found to be constant, and when compared with the nitrate solution of the same $Cd^{++}$ concentration at the same ionic strength, the limiting current decreased by 28% and the halfwave potential shifted by -0.05 volt. The values of limiting current sharply decreased as the pH value exceeded 8.2 and the minimum values appeared at the pH values of 11.2~11.4. The values of halfwave potential gradually decreased as the pH value increased over 8.2 and the value of -0.78 volt was obtained at the pH value of 12.6. Possible mechanisms of electrode reaction were suggested and the anomalous behavior of reduction waves of Cd(II) in tartrate solution up to pH value of 9.4 was discussed.

• Journal of the Korean GEO-environmental Society
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• v.9 no.2
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• pp.23-29
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• 2008

It has been mentioned that CSTR (Completely Stirred Tank Reactor) and UASB (Upflow Anaerobic Sludge Blanket) processes, the existing anaerobic processes, have problems in the treatment of highly concentrated particulate organic wastewater (HCPOW). Therefore, this paper discusses the treatment possibility of distillery wastewater which is a typical HCPOW using ADEPT (anaerobic Digestion Elutriated Phased Treatment) process. In the comparison of CSTR and ADEPT, ADEPT produced much higher gas than that of CSTR removing more organic matters and suspended solids in ADEPT process, ADEPT had no effect on the decrease in pH by volatile fatty acids and showed steady pH in spite of relatively short HRT. In the results of removal rate according to recycle ratios between 6Qin and 2Qin in ADEPT, 6Qin showed high removal rate during the operation time. Therefore it appears that ADEPT had an applicability for the treatment of distillery wastewater. ADEPT could be a economical process, due to the short HRT, the energy recovery by the methane production, and the utilization for carbon source of produced organic acid from the ADEPT-acid reactor.

• Electronics and Telecommunications Trends
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• v.22 no.1 s.103
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• pp.11-23
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• 2007

초기에 P2P가 등장할 때만 해도 저작권, 보안 등의 문제 등으로 인해 ‘문제아’ 정도로 인식되었던 것은 사실이다, 그러나 최근 들어서는 P2P를 응용 인프라 구축을 위한 하나의 통신계층으로 보는 시각이 등장할 정도로 인터넷에서 매우 대중화된 서비스가 되어 버렸으며, 실제로 VoIP, video streaming, game 등 매우 다양한 응용의 인프라로 P2P가 사용되고 있다. 본 고에서는 이러한 P2P에 대한 표준화 및 기술 동향, 보안 취약성 및 대응 기술 등을 살펴본다.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.289-294
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• 2018

A test study was conducted to identify the effects of diathermy through therapist's hand on patients with chronic lumbar pain. The study assessed the effectiveness of Winback High Frequency TECAR Therapy on 21 patients suffering from chronic lumbar pain and the testing was held at H Hospital and began in April 2016 and concluded in September 2016. Assessment of pain relief was through a Visual Analogue Scale (VAS) and the Oswestry Disability Questionnaire (ODQ). The results showed a VAS score decrease from $6.67{\pm}1.76$ to $5.52{\pm}2.03$ (p<0.05) and the ODQ results also showed an decrease from $41.19{\pm}2.56$ to $35.14{\pm}5.11$ (p<0.05). Both of these results are indicative of the positive effects that diathermy through therapist's hand has in the treatment of chronic pain, and the necessity for further studies in this field.