• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.142-142
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• 2017

High Flory-Huggins interaction parameter (${\chi}$)를 가지는 polystyrene-block-dimethylsiloxane (PS-b-PDMS)는 초미세 패턴 제작과 우수한 defect density, 우수한 edge roughness 특성으로 향상된 패턴을 제공한다는 점에서 반도체 분야에서 많은 연구가 되고 있다. 하지만, PS와 PDMS 사이에 존재하는 큰 surface tension의 차이로 인해 PDMS는 PS와 air 사이에서 segregate되기 때문에 수직배향에 불리하여 high aspect ratio (HAR)을 가지는 cylinder, lamellar 패턴 제작에 있어 큰 어려움을 가진다. 본 연구에서는 이러한 문제를 해결하기 위해, PS-b-PDMS BCP 패턴과 하부 실리콘 기판 사이에 amorphous carbon layer (ACL)를 삽입하여 효과적으로 pattern transfer하는 공정을 연구하였다. 플라즈마를 이용하여 무한대에 가까운 etch selectivity를 가지는 식각 공정을 개발함으로써 낮은 aspect ratio를 가지는 PS-b-PDMS BCP 패턴의 한계점을 극복하였다. Large-x value를 가지는 BCPs를 이용하여도 매우 높은 aspect ratio를 가지면서 동시에 pattern quality를 향상시킬 수 있는 plasma process를 제시하였다.

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.41-55
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• 1998

An analysis of 87 stroke Patients who were enrolled in 7 hospitals in cities of Pusan, Taegu, Kumi, and Andong from January 1 to May 31, 1998 was conducted using the modified Barthel Index(BI) and the adapted PULSES profile index(PS) to evaluate their function. Patients were examined at the following intervals : Initial assessment, one month after initial, at discharge, and ore month after discharge. The mean BI score of patients initial assessment was 26.32. and that of PS was 17.34. There were statistically significant between initial score and one month after initial (16.61 : p<0.001), at discharge(33.51 : p<0,001), one month after discharge(43,56 : p<0.001). PS scores were also improved significantly(-2.1, -3. 94, and -5.52(p<0.001), and BI score between discharge and one month after discharge wag significant improvement(10.06 : p <0.001) and in PS score(-1,57 : p<0.001). Age and BI scone were significantly associated with the improved in BI score between initial and discharge (T3-T1)(p<0.05). Below age forty and the lower initial BI score showed significantly higher improvement(T3-T1) after physical therapy(p<0.05). Initial BI score, BI score at discharge, and religion were significantly associated with the improvement of BI score between initial and one month after discharge(T4-T1)(p<0.05). The lower initial BI score, the high. BI score at discharge, and the religious showed significantly higher improvement(T4-T1)(p<0.05). BI score at discharge and religion were significantly associated with the improvement of BI score between at discharge and one month after discharge(T4-T3)(p<0.05). The lower BI score at discharge, the religious showed significantly higher improvement(T4-T3)(p<0.05) Initial PS score were significantly associated with the improved in PS score between initial and discharge(T3-T1)(p<0.05). The higher initial PS score showed significantly hier improvement(T3-T1)(p<0.05). Initial PS score, Bi score at discharge, and patient's attitude for physical therapy after discharge were significantly associated with the improvement of PS score between initial and one month after discharge(T4- T1)(p <0.05). The higher initial PS scorer the lower PS score at discharge, patient's positive attitude for physical therapy after discharge showed significantly higher improvement(T4-T1)(p<0.05). PS score at discharge, Patient's attitude for Physical therapy after discharge were significantly associated with the improvement of PS score between discharge and one month after discharge(T4-T3)(p<0.05). The higher PS score at discharge, patient's positive attitude for physical therapy after discharge showed significantly higher improvement(T4-T3)(p<0.05). In conclusion, Initial BI score, BI score at discharge, age, and religion were significantly associated with BI score improvement. initial PS score, BI score discharge, and patient's attitude for physical therapy after discharge were significantly associated with PS score improvement in stroke patients.

• Korean Journal of Microbiology
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• v.19 no.4
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• pp.179-185
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• 1981

Facultative psychrophilic bacteria utilizing SDBS (Sodium Dodecyl Benzene Sulfonate) as their carbon source were isolated in the Han River. All of these isolated faculatative psychrophilic bacteria were identified as Pseudomonas spp. The growth and biodegradation rates of Ps.fluorescens LP6, Ps. fluorescens LS6 and Ps. putida LC1 among 8 identified facultative psychrophilic bacteria were investigated with spectrophotometer. The specific growth rates of these three facultative psychrophilic bacteria at $25^{\circ}C$ were higher than those at any other temperatures. However, the final cell yields were the highest for cells grown at $5^{\circ}C$. The biodegradation of SDBS by Ps. fluorescens LP 6 was started at the stationary phase of cells. The biodegradation rate of SDBS by Ps. fluorescens LP6 was the highest when the cells were cultured at $25^{\circ}C$.

• Journal of Korea Multimedia Society
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• v.2 no.3
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• pp.329-338
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• 1999

In this paper we propose a WATM MAC protocol called DTDD/PS (Dynamic Time Division Duplex using Poll/Select scheme). The idea of the DTDD/PS protocol is based that a radio cell is considered as queueing system. The MAC controller in base station is charged in coordinating terminals for the QoS requirement from each terminal. For that reason, terminals send it's own dynamic parameter represented its status, and controller controls the access of terminals and assigns time slots dynamically using received parameters. Therefore this system can satisfy the QoS of real-time service in wireless environments. To evaluate DTDD/PS protocol simulations are executed. In 25Mbps channel capacity, the voice and data coexist traffic situation, as the total number of terminal is increased, the delay of data terminals is increased rapidly. But the case of only increasing data terminals, the number of supported voice terminals is not varying. Therefore we can expect that DTDD/PS protocol can applied to multimedia traffic effectively.

• Korean Journal of Breeding Science
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• v.40 no.1
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• pp.48-53
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• 2008

This study presents a case study designed to compare the selection efficiency between phenotypic selection (PS) and marker-assisted selection (MAS) in breeding of resistance lines to brown planthopper (BPH). The efficiency between PS and MAS were compared with four population such as the $F_2$, RILs ($F_6$), DH, and backcrosse ($BC_6F_5$) population, derived from a cross 'Samgang / Nagdong'. The resistance lines were selected using two markers, RM28493 and BpE18-3, related to BPH resistance were screened as resistance lines over 95% in PS. The costs required for BPH screening in the MAS system account for approximately 32% of the total costs of PS. The period needed to select the resistance plants was 30 days in PS and 7 days in MAS. Based on the results, we could establish the breeding system for selection of BPH resistance lines by MAS.

• Membrane Journal
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• v.6 no.4
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• pp.273-283
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• 1996

A cation-exchange membranes were prepared by polystyrene and poly(sodium 4-styrene sulfonate). The degree of crosslinking of polystyrene membranes was controlled by DVB. At the same time, the structure of PS membranes was changed from RO to MF by varying the concentration of PSS in the casting solution. Water flux increased with PS-PSS membranes due to the sulfonate groups, and final membrane cast from the solution containing 5% of DVB and 3% of PSS showed MF structure.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.94.3-95
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• 2003

Familial form of Alzheimer's disease (FAD) is caused by mutations in presenilin-l (PS-1) and presenilin-2 (PS-2). PS1 and PS2 mutation are known to similar effects on the production of amyloid peptide (A ) and cause of neuronal cell dath in the brain of patient of Alzheimer's disease. The importance of the alternation of cellular calcium homeostasis in the neuronal cell death by PS1 mutation in a variety of experimental systems has been demonstrated. However, no studies on the effect of PS2 of mutant PS2 on cellular calcium homeostasis, and relevance of its change to neuronal cell vulnerability against neurotoxins have been reported. (omitted)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.306-307
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• 2015

유기태양전지의 대표적 Hole Transporting Layer(HTL)로는 전도성 고분자인 PEDOT:PSS이다. PEDOT:PSS는 약산성의 물질로 전극을 부식시켜 디바이스의 효율을 감소시키기 때문에 PEDOT:PSS를 대체하기 위한 Buffer층에 대한 연구가 활발히 진행되어지고 있다. PEDOT:PSS를 대체할 수 있는 Nickel Oxide(NiO) Buffer 층은 wide band-gab으로 Hole Transporting Layer와 Electron Blocking Layer 역할을 동시에 하여 디바이스의 효율을 향상시킬 수 있으며, 디바이스의 수명을 향상시킬 수 있다는 장점이 있다. NiO는 용액공정과 Sputter 증착 방법으로 형성할 수 있는데, 용액공정은 고온공정이 요구되어지고 Sputter 증착방법은 산화되기 쉬운 전극위에서는 전극의 손상을 발생한다. 본 연구에서는 이러한 단점을 해결하기 위해서 Ni을 Magnetron Sputter로 증착한 후 Ion Beam 처리를 통해 산화시켜 NiO 층을 형성하는 방법을 연구하였다. 본 연구에서 제안한 NiO형성 방법으로 유기태양전지를 제작하여 PEDOT:PSS를 Buffer층으로 사용한 태양전지와 Voc가 0.72 V로 유사하게 나와 NiO가 Buffer층으로 잘 형성된 것을 확인하였다.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.40-44
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• 2018

An isolate capable of inhibiting the growth of gram-positive bacteria was obtained from the soil of Mushim stream, Cheongju. The isolate was identified as Pseudomonas otitidis PS by 16S rRNA gene sequence analysis. P. otitidis PS produced antibiotics as a secondary metabolite when cultured in 1% soybean meal with 0.5% glucose. The maximum yield was about 0.1%. The antibiotic substance of P. otitidis PS extracted using ethyl acetate displayed a minimum inhibitory concentration of $2{\mu}g/ml$ for Staphylococcus aureus KCTC 1261. The antibiotic substance produced an orange halo on chrome azurol S agar due to siderophore activity. Growth inhibition was decreased when the iron was depleted. Since the antibiotic activity was lost upon the addition of the reducing agent ascorbic acid or during anaerobic culture, it was considered that antibiotic of P. otitidis PS strain exerts its bactericidal effect by the generation of reactive oxygen species.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1482-1489
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• 2009

In this study, we investigated the anti-proliferative effect of polysaccharides from Salicornia herbacea on HT-29 human colon cancer cells. Crude polysaccharides from S. herbacea (CS) were prepared by extraction with hot steam water, and fine polysaccharides from S. herbacea (PS) were obtained through further size exclusion chromatography. The anti-proliferative effect of CS and PS were measured using the MTS assay, apoptosis analysis, cell cycle analysis, and RT-PCR. HT-29 cells were treated with CS or PS at different dosages (0.5, 1, 2, 4 mg $ml^{-1}$) for 24 or 48 h. CS and PS inhibited proliferation and stimulated apoptosis of cells in a dose-dependent manner. Flow cytometric analysis after Annexin V-FITC and PI staining revealed that treatment with CS or PS increased total apoptotic death of cells to 24.99% or 91.59%, respectively, in comparison with the control (13.51 %). PS increased early apoptotic death substantially - up to 12 times more than the control. Treatment with CS or PS resulted in a concentration-dependent increase of the G2/M cell population of the cell cycle as determined by flow cytometry. G2/M arrest was induced significantly with the highest concentration (4 mg $ml^{-1}$) of PS. RT-PCR was performed to study the correlation between G2/M arrest and transcription of cell cycle control genes. The anti-proliferative activity of CS and PS was accompanied by inhibition of cyclin B1, and Cdc 2 mRNA. Moreover, both CS and PS induced expression of the p53 tumor suppressor gene and the Cdk inhibitor p21. These results suggest that polysaccharides from S. herbacea have anti-cancer activity in human colon cancer cells.