• Journal of Life Science
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• v.19 no.6
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• pp.787-792
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• 2009

In this study, protease-producing bacteria were isolated from the marine sedimentary layer in coastal Jeju. We isolated 2 protease producing strains (SK-2 and SK-125) and tested their protesase producing activities. Gram staining and BIOLOG of isolated strains revealed that strains SK-2 and SK-125 belong to Bacillus and Pseudoalteromonas families, respectively. The 16S rDNA nucleotide sequences analyses of the isolated strains showed 99% sequence homology with those of Bacillus sp. and Pseudoalteromonas sp.; therefore, the isolated strains SK-2 and SK-125 were named Bacillus sp. SK-2 and Pseudoalteromonas sp. SK-125, respectively. The optimum conditions for the cell growth of protease activities were obtained when the both isolates were cultured at $30^{\circ}C$, 96 hrs and pH $7{\sim}8$.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2087-2097
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• 2016

Most cold-adapted enzymes possess higher $K_m$ and $k_{cat}$ values than those of their mesophilic counterparts to maximize the reaction rate. This characteristic is often ascribed to a high structural flexibility and improved dynamics in the active site. However, this may be less convincing to cold-adapted metabolic enzymes, which work at substrate concentrations near $K_m$. In this respect, cold adaptation of a shikimate kinase (SK) in the shikimate pathway from psychrophilic Colwellia psychrerythraea (CpSK) was characterized by comparing it with a mesophilic Escherichia coli homolog (EcSK). The optimum temperatures for CpSK and EcSK activity were approximately $30^{\circ}C$ and $40^{\circ}C$, respectively. The melting points were $33^{\circ}C$ and $45^{\circ}C$ for CpSK and EcSK, respectively. The ${\Delta}G_{H_2O}$ (denaturation in the absence of denaturing agent) values were 3.94 and 5.74 kcal/mol for CpSK and EcSK, respectively. These results indicated that CpSK was a cold-adapted enzyme. However, contrary to typical kinetic data, CpSK had a lower $K_m$ for its substrate shikimate than most mesophilic SKs, and the $k_{cat}$ was not increased. This observation suggested that CpSK may have evolved to exhibit increased substrate affinity at low intracellular concentrations of shikimate in the cold environment. Sequence analysis and homology modeling also showed that some important salt bridges were lost in CpSK, and higher Arg residues around critical Arg 140 seemed to increase flexibility for catalysis. Taken together, these data demonstrate that CpSK exhibits characteristics of cold adaptation with unusual kinetic parameters, which may provide important insights into the cold adaptation of metabolic enzymes.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.499-502
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• 2012

빅 데이터 분석의 시대가 도래하면서 대용량 데이터의 특성과 계산 집약적 연산의 특성을 동시에 가지는 문제 해결에 대한 요구가 늘어나고 있다. 대용량 데이터 처리의 경우 각종 분산 파일 시스템과 분산/병렬 컴퓨팅 기술들이 이미 많이 사용되고 있으며, 계산 집약적 연산 처리의 경우에도 GPGPU 활용 기술의 발달로 보편화되는 추세에 있다. 하지만 대용량 데이터와 계산 집약적 연산 이 두 가지 특성을 모두 가지는 문제를 처리하기 위해서는 많은 제약 사항들을 해결해야 하는데, 본 논문에서는 이에 대한 대안으로 분산 컴퓨팅 프레임워크인 Hadoop MapReduce와 Nvidia의 GPU 병렬 컴퓨팅 아키텍처인 CUDA 흘 연동하는 방안을 제시하고, 이를 밀집행렬(dense matrix) 연산에 적용했을 때 얻을 수 있는 성능 개선 효과에 대해 소개하고자 한다.

• Asia Marketing Journal
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• v.16 no.1
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• pp.195-214
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• 2014

Many oil refinery companies have been proactively carried out marketing activities to survive in highly intensified service station industry. In 2012, SK Energy ranked number one in three customer satisfaction surveys (NCSI, KCSI, and KS-SQI). SK Energy's success is in its differentiated customer satisfaction business strategy. SK Energy has been implementing various marketing activities. As a part of the activities, it issued an affinity credit card with on spot discount privilege for the first time in the oil refinery industry. SK Energy also issued EnClean bonus card for OK Cashbag points that can be used for discounts at the service stations. On top of all, SK Energy generated point value-up with '3K Exclusive Privilege' program. In addition, team 'CS 119' was formed to noticeably improve the service. 'CS 119' visited each service station, diagnosed its CS service level then provided customized field training for improvement. Long-termimplementation of 'ACE Program', a field-base CS monitoring system, regularly checked customer satisfaction level. 'ACE Program' has significantly contributed improving SK Service Station's service quality and customer satisfaction. This case reviews customer satisfaction marketing activities SK Energy carried out. The focus is on distinctive factors that distinguish SK Energy's customer satisfaction marketing activities from competitors.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.318.1-318.1
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• 2001

• Toxicological Research
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• v.19 no.2
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• pp.147-152
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• 2003

We investigated antitumor activities of the ethanol extract from mushroom Phellinus linteus and Phellinus baumii on mulberry, oak and elm. in vitro test, the ethanol extract of mushroom cultivated on oak of Phellinus linteus showed highest activities about SK-OV-3, HCT15, XF498, SK-MEL-2 and A549. SK-OV-3 cell line showed 100% cytotoxicity in 100 $\mu\textrm{g}$/ml and HCT15 (98.39%), XF498 (89.62%), SK-MEL-2 (84.07%) and A549 (79.92%) cytotoxicity respectively. Also $IC_{50}$ showed 3.99 $\mu\textrm{g}$/ml to SK-OV-3 cell line and HCT15 (4.37 $\mu\textrm{g}$/ml), A549 (5.48 $\mu\textrm{g}$/ml), SK-MEL-2 (6.72 $\mu\textrm{g}$/ml), XF 498 (6.88 $\mu\textrm{g}$/ml). As those results, cultivated oak of Phellinus linteus showed a very low $IC_{50}$ value against SK-OV-3, HCT15, XF498, SK-MEL-2 and A549 cancer cell lines.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.146.1-146.1
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• 2003

Joins (SKI 306X) is now clinically used for the treatment of osteoarthritis (OA). In previous reports, Joins, a natural herbal product extracted from three herbs Clematis Radix, Trichosanthes Radix and Prunella Flos, was shown to have good analgesic and anti-inflammatory effects and cartilage protective effects in several experimental models. In this study we characterized the effects of Joins on the gastric mucosa and compared to that of diclofenac. (omitted)

• Annual Conference on Human and Language Technology
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• 2022.10a
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• pp.53-58
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• 2022

인공지능 기술이 발전하며, 다양한 산업군에 사람의 업무를 보조하는 인공지능 시스템이 적용되고 있다. 그 중 콜센터 상담사의 상담 업무를 보조하는 자연어 처리 기술 역시 활발히 연구되고 있는 분야 중 하나이다. 콜센터 상담사 보조 시스템은 상담사를 보조하기에 앞서 고객과 상담사의 대화로 진행되는 상담이 어떤 내용인지 정확히 인식해야 한다. 이때, 시스템이 상담의 목적을 대표할 수 있는 발화를 판별한다면 상담 내용을 보다 명확히 인식할 수 있다. 본 논문은 구어체로 진행되는 상담 스크립트의 특징을 주목하여, 실시간으로 상담 내용을 분석하고, 중요한 의미를 가지는 발화를 인지하여 추출하는 모델을 제안한다. 실험 결과, 제안한 모델이 기존 추출 요약과 비교하여, 우수한 성능을 보였다. 본 논문에 제안한 모델을 적용하여, 주요 상담 발화를 추출하고, 관련된 상담 문서 검색, 상담 내용 분류 등에 적용할 수 있다.

• TTA Journal
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• s.94
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• pp.57-64
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• 2004

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2000.11a
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• pp.49-53
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• 2000