• 제목/요약/키워드: H-domain

검색결과 1,353건 처리시간 0.028초

추천시스템의 효과적 도입을 위한 소셜네트워크 분석 (Social Network Analysis for the Effective Adoption of Recommender Systems)

  • 박종학;조윤호
    • 지능정보연구
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    • 제17권4호
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    • pp.305-316
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    • 2011
  • 협업필터링은 다양한 분야에서 널리 활용되고 있지만 협업필터링의 추천 성능은 적용하는 기업의 비즈니스 형태나 발생하는 거래 데이터의 특성에 따라 다르게 나타나고 있다. 기업에서 협업필터링 추천시스템을 구축하려면 상당한 시간과 비용이 소요되기 때문에 구축된 추천시스템의 성과가 높지 않다면 기업 자원의 낭비를 초래할 뿐만 아니라 부정확한 추천서비스를 받는 고객들의 불만을 살 수 있다. 따라서 추천시스템 도입을 검토할 때 기업이 갖고 있는 데이터의 특성을 파악하고 이를 통해 추천시스템을 도입하는 것이 타당한지 사전에 예측할 수 있다면 불필요한 도입으로 인한 경제적 손실과 고객 만족도 저하를 막을 수 있을 것이다. 기존 연구에서는 협업필터링 추천 성과에 희박성, 우연성, 커버리지 등이 영향을 미칠 수 있다고 설명하고 있지만 이러한 요인들이 어떻게 얼마나 추천 성과에 영향을 미치는지, 요인들 간에 어떠한 상관관계가 있는지는 현재까지 구체적으로 밝혀진 바가 없다. 본 연구에서는 구매 트랜잭션으로부터 생성된 소셜네트워크로부터 밀도, 군집화계수, 집중도 등의 구조적 지표를 측정한 후 이들이 추천성과에 어떻게 영향을 미치는지 통계적 분석을 통해 실증적으로 규명한다. 이를 통해 협업필터링 추천시스템에 대한 도입 여부를 결정하고자 할 때 유용하게 사용될 수 있는 지침을 제공하고자 한다.

메탄올 자화효모 Hansenula polymorpha에서의 재조합 단백질 분비발현을 위한 인체 혈청 알부민 융합단편의 활용 (Use of Human Serum Albumin Fusion Tags for Recombinant Protein Secretory Expression in the Methylotrophic Yeast Hansenula polymorpha)

  • 송지혜;황동현;오두병;이상기;권오석
    • 한국미생물·생명공학회지
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    • 제41권1호
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    • pp.17-25
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    • 2013
  • 메탄올 자화효모 Hansenula polymorpha에서 분비 발현이 잘 된다고 보고된 인체 혈청 알부민(human serum albumin, HSA)을 융합단편으로 사용하여 외래 재조합 단백질을 효과적으로 분비 발현할 수 있는 발현시스템을 개발하고자 하였다. 이때 조작의 용이성 및 발현 효율 제고를 위하여 전장의 HSA 뿐만 아니라 세 종류의 각기 다른 크기의 HSA 단편을 설계하여 융합단편으로 사용하였다. 즉 HSA의 N-말단으로 부터 각기 137, 172, 320, 608개 아미노산을 갖는 융합단편 HSAft (1-4)를 제작하였다. 아울러 발현되는 HSA 단편의 검출 및 분리정제를 위한 His8-tag, HSA 융합단편과 외래 단백질간의 유연성을 부여하기 위한 2조의 $Gly_4Ser_1$ linker, 융합 발현된 타겟 단백질을 HSA 단편으로부터 용이하게 분리하기 위한 담배식각바이러스 단백질분해효소(tobacco etch virus protease, Tev) 인지 서열, 타겟 단백질 유전자를 클로닝하기 위한 멀티 클로닝 사이트(multiple cloning site, MCS)서열, 그리고 타겟 재조합 단백질의 발현 검출 및 정제를 위한 Strep-tag을 포함하는 작용기 도메인을 발현카세트 기본 골격에 포함시켰다. 이렇게 구축된 4종의 HSA 융합단편 분비발현 벡터를 H. polymorpha에 형질전환한 후 각 융합단편의 발현을 조사한 결과 HSAft 단편 3, 4의 발현을 확인할 수 있었다. 녹색형광단백질 유전자 ($GFP_{uv}$)를 상기 벡터에 클로닝한 후 H. polymorpha에 도입한 결과 형질 전환체 모두에서 녹색형광단백질의 발현을 관찰 할 수 있었다. 해당 세포로부터 분비되거나 세포내에 발현되는 HSA 단편 융합 형광단백질의 발현양을 비교한 결과 HSAft 단편 4에 융합된 경우를 제외하고 나머지 경우 모두에서 세포 파쇄액과 세포 배양액 양쪽에서 해당 HSA 단편 융합 형광단백질의 발현을 확인 할 수 있었다. 한편 HSA 융합단편의 크기에 따라 자체 혹은 타겟 단백질과 융합된 형태의 단백질 분비 발현 정도가 달라지는 것은 해당 단백질의 접힘이나 단백질 분해효소에 대한 민감성 등 여러 변수에 의한 것으로 사료되며 따라서 본 연구에서 개발한 H. polymorpha용 HSA 융합단편 분비발현 시스템은 특정 외래 재조합 단백질의 효율적인 분비발현 융합단편의 선별 및 과발현 시스템 구축에 유용하게 활용될 수 있을 것으로 기대된다.

A $G_{4}$ Sequence within PHR1 Promoter Acts as a Gate for Cross-Talks between Damage-Signaling Pathway and Multi-Stress Response

  • Jang, Yeun-Kyu;Kim, Eun-Mi;Park, Sang-Dai
    • Animal cells and systems
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    • 제6권3호
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    • pp.271-275
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    • 2002
  • Rph1 and Gisl are damage-responsive repressors involved in PHR1 expression. They have two $C_{2}$H/ sub 2/ zinc finger motifs as putative DNA binding domains and N-terminal conserved domain with unknown function. They are also found in the human retinoblastoma binding protein 2 and the mouse jumonji- encoded protein. The repressors are able to bind to A $G_{4}$ sequence within a 39-bp sequence called upstream repressing sequence of PHR1 promoter (UR $S_{PHR1}$) responsible for the damage-response of PHR1. We report here that Rph1 is predominantly localized in the nucleus as examined by fluorescence microscopic analysis with GFP-Rph1 fusion protein. On the basis of the fact that the A $G_{4}$ sequence that is recognized by Rph1 and Gisl is also recognized by Msn2 and Msn4 in a process of stress response, we a1so tried to examine the in vivo function of A $G_{4}$ and the role of Msn2 and Msn4 in PHR1 expression. Our results demonstrate that Msn2 and Msn4 are actually required for the basal transcription of PHR1 expression but not for its damage induction. When A $G_{4}$ sequence was inserted into the minimal promoter of the cyc1-LacZ reporter, the increased LacZ expression was observed indicating its involvement in transcriptional activation. The data suggest that the A $G_{4}$ is primarily required for basal transcriptional activation of PHR1 or CYC1 promoter through the possible involvement of Msn2 and Msn4. However, since the A $G_{4}$ is also involved in the repression of PHR1 via Rphl and Gisl, it is proposed that A $G_{4}$ functions as either URS or upstream activating sequence (UAS) depending on the promoter context.t.

Co-Ni 합금위에서 수직방향으로 정렬된 탄소나노튜브의 성장 (Growth of vertically aligned carbon nanotubes on Co-Ni alloy metal)

  • 이철진;김대운;이태재;박정훈;손권희;류승철;송홍기;최영철;이영희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1504-1507
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    • 1999
  • We have grown vertically aligned carbon nanotubes in a large area of Co-Ni codeposited Si substrates by the thermal CVD using $C_2H_2$ gas. Since the discovery of carbon nanotubes, Synthesis of carbon nanotubes for mass production has been achieved by several methods such as laser vaporization arc discharge, and pyrolysis. In particular, growth of vertically aligned nanotubes is of technological importance for applications to FED. Recently, vertically aligned carbon nanotubes have been grown on glass by PECVD Aligned carbon nanotubes can be also grown on mesoporous silica and Fe patterned porous silicon using CVD. Despite such breakthroughs in the growth, the growth mechanism of the alignment are still far from being clearly understood. Furthermore, FED has not been clearly demonstrated yet at a practical level. Here, we demonstrate that carbon nanotubes can be vertically aligned on catalyzed Si substrate when the domain density reaches a certain value. We suggest that steric hindrance between nanotubes at an initial stage of the growth forces nanotubes to align vertically and then nanotubes are further grown by the cap growth mechanism.

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한국인 인면역결핍 바이러스의 V3 Loop 염기서열 분석 및 계통발생학적 분석 (Sequence and Phylogenetic Analysis of V3 Region of Human Immunodeficiency Virus Type 1 Strains Isolated from Korean Patients)

  • 김영봉;조영걸;이희정;정구헌;김정우;김유겸;양재명
    • 대한바이러스학회지
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    • 제26권2호
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    • pp.251-258
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    • 1996
  • The V3 loop, a hypervariable domain of envelope glycoprotein, has an essential role in viral infectivity and has a major epitope for type-specific neutralizing antibody. In order to investigate genetic diversity of V3 region of gp120 of human immunodeficiency virus type 1 (HIV-1) isolated from Korean patients, DNA sequences encoding the C2 to V3 region were amplified by nested polymerase chain reaction (PCR) from uncultured peripheral blood mononuclear cells obtained from 15 HIV-1 seropositive patients and nucleotide sequences were determined. All nucleotide sequences from fifteen patients were compared with 8 distinctive subtypes (A-H) and another subtype O. Phylogenetic analysis was carried out with PHYLIP ver 3.5 (Dnapars) program. Of the 15 isolates, 14 HIV-1 subjects were clustered with subtype B, while one was clustered with subtype C. Intra-subtype B distance at the nucleotide and deduced amino acid level were maximum 17.7% and 37.0%, respectively. Intra-patient distance at the nucleotide and deduced amino acid level were maximum 7.3% and 17.8%, respectively. Analysis of the nucleotide sequences revealed that Korean types have relatively well conserved sequences. These findings could be useful for assessing the source of infection and developing an AIDS vaccine.

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Buffeting response control of a long span cable-stayed bridge during construction using semi-active tuned liquid column dampers

  • Shum, K.M.;Xu, Y.L.;Guo, W.H.
    • Wind and Structures
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    • 제9권4호
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    • pp.271-296
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    • 2006
  • The frequency of a traditional tuned liquid column damper (TLCD) depends solely on the length of liquid column, which imposes certain restrictions on its application to long span cable-stayed bridges during construction. The configuration of a cable-stayed bridge varies from different construction stages and so do its natural frequencies. It is thus difficult to apply TLCD with a fixed configuration to the bridge during construction or it is not economical to design a series of TLCD with different liquid lengths to suit for various construction stages. Semi-active tuned liquid column damper (SATLCD) with adaptive frequency tuning capacity is studied in this paper for buffeting response control of a long span cable-stayed bridge during construction. The frequency of SATLCD can be adjusted by active control of air pressures inside the air chamber at the two ends of the container. The performance of SATLCD for suppressing combined lateral and torsional vibration of a real long span cable-stayed bridge during construction stage is numerically investigated using a finite element-based approach. The finite element model of SATLCD is also developed and incorporated into the finite element model of the bridge for predicting buffeting response of the coupled SATLCD-bridge system in the time domain. The investigations show that with a fixed container configuration, the SATLCD with adaptive frequency tuning can effectively reduce buffeting response of the bridge during various construction stages.

An integrated model for pore pressure accumulations in marine sediment under combined wave and current loading

  • Zhang, Y.;Jeng, D.-S.;Zha, H.-Y.;Zhang, J.-S.
    • Geomechanics and Engineering
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    • 제10권4호
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    • pp.387-403
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    • 2016
  • In this paper, an integrated model for the wave (current)-induced seabed response is presented. The present model consists of two parts: hydrodynamic model for wave-current interactions and poro-elastic seabed model for pore accumulations. In the wave-current model, based on the fifth-order wave theory, ocean waves were generated by adding a source function into the mass conservation equation. Then, currents were simulated through imposing a steady inlet velocity on one domain and pressure outlet on the other side. In addition, both of the Reynolds-Averaged Navier-Stokers (RANS) Equations and $k-{\varepsilon}$ turbulence model would be applied in the fluid field. Once the wave pressures on the seabed calculated through the wave-current interaction model, it would be applied to be boundary conditions on the seabed model. In the seabed model, the poro-elastic theory would be imposed to simulate the seabed soil response. After comparing with the experimental data, the effect of currents on the seabed response would be examined by emphasize on the residual mechanisms of the pore pressure inside the soil. The build-up of the pore water pressure and the resulted liquefaction phenomenon will be fully investigated. A parametric study will also be conducted to examine the effects of waves and currents as well as soil properties on the pore pressure accumulation.

유기화합물의 승화열 예측을 위한 QSPR분석 (QSPR analysis for predicting heat of sublimation of organic compounds)

  • 박유선;이종혁;박한웅;이성광
    • 분석과학
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    • 제28권3호
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    • pp.187-195
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    • 2015
  • 승화열은 대기 유기 오염물질의 확산에 관련된 환경적인 문제를 해결하거나, 위험한 화학 물질의 위해성을 평가하는 데에 중요한 변수이다. 하지만 실험적으로 승화열을 측정하려면 많은 시간과 비용이 소모 되며, 그 실험자체도 복잡하고 위험하다. 따라서 본 연구에서는 유기화합물의 승화열을 간단하게 예측하는 모델을 개발하기 위하여 정량적 구조-물성 상관관계 연구를 이용하였다. 군기반 전진선택방법을 적용하여 다중선형회귀방법과 서포트 벡터 머신과 같은 학습방법에 적합한 분자표현자들을 선택하도록 하였다. 개별 모델과 복합모델들은 부스트래핑 방법과 y-임의추출법에 의해 내부검증이 되었다. 외부 테스트 데이터의 예측 성능은 적용범위를 고려하므로서 개선되었다. 다중선형회귀모델에 따르면, 승화열은 분자간의 분산력, 수소결합, 정전기적 상호작용, 쌍극자-쌍극자 상호작용과 관련이 있는 것을 나타낼 수 있었다.

Ectopic Overexpression of COTE1 Promotes Cellular Invasion of Hepatocellular Carcinoma

  • Zhang, Hai;Huang, Chang-Jun;Tian, Yuan;Wang, Yu-Ping;Han, Ze-Guang;Li, Xiang-Cheng
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권11호
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    • pp.5799-5804
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    • 2012
  • Family with sequence similarity 189, member B (FAM189B), alias COTE1, a putative oncogene selected by microarray, for the first time was here found to be significantly up-regulated in hepatocellular carcinoma (HCC) specimens and HCC cell lines. mRNA expression of COTE1 in HCC samples and cell lines was detected by reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR, while protein expression of COTE1 in HCC tissues was assessed by immunohistochemistry. In addition, invasion of HCC cells was observed after overexpressing or silencing COTE1. In the total of 48 paired HCC specimens, compared with the adjacent non-cancer tissues, the expression of COTE1 was up-regulated in 31 (p<0.01). In HCC cell lines, COTE1 expression was significantly higher than in normal human adult liver (p<0.01). Overexpression of COTE1 enhanced HCC-derived LM6 and MHCC-L cellular invasion in vitro. In contrast, COTE1 knockdown via RNAi markedly suppressed these phenotypes, as documented in LM3 and MHCC-H HCC cells. Mechanistic analyses indicated that COTE1 could physically associate with WW domain oxidoreductase (WWOX), a tumor suppressor. COTE1 may be closely correlated with invasion of hepatocellular carcinoma (HCC) cells and thus may serve as an effective target for gene therapy.

Cloning and Functional Characterization of Ptpcd2 as a Novel Cell Cycle Related Protein Tyrosine Phosphatase that Regulates Mitotic Exit

  • Zineldeen, Doaa H.;Wagih, Ayman A.;Nakanishi, Makoto
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권6호
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    • pp.3669-3676
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    • 2013
  • Faithful transmission of genetic information depends on accurate chromosome segregation as cells exit from mitosis, and errors in chromosomal segregation are catastrophic and may lead to aneuploidy which is the hallmark of cancer. In eukaryotes, an elaborate molecular control system ensures proper orchestration of events at mitotic exit. Phosphorylation of specific tyrosyl residues is a major control mechanism for cellular proliferation and the activities of protein tyrosine kinases and phosphatases must be integrated. Although mitotic kinases are well characterized, phosphatases involved in mitosis remain largely elusive. Here we identify a novel variant of mouse protein tyrosine phosphatase containing domain 1 (Ptpcd1), that we named Ptpcd2. Ptpcd1 is a Cdc14 related centrosomal phosphatase. Our newly identified Ptpcd2 shared a significant homology to yeast Cdc14p (34.1%) and other Cdc14 family of phosphatases. By subcellular fractionation Ptpcd2 was found to be enriched in the cytoplasm and nuclear pellets with catalytic phosphatase activity. By means of immunofluorescence, Ptpcd2 was spatiotemporally regulated in a cell cycle dependent manner with cytoplasmic abundance during mitosis, followed by nuclear localization during interphase. Overexpression of Ptpcd2 induced mitotic exit with decreased levels of some mitotic markers. Moreover, Ptpcd2 failed to colocalize with the centrosomal marker ${\gamma}$-tubulin, suggesting it as a non-centrosomal protein. Taken together, Ptpcd2 phosphatase appears a non-centrosomal variant of Ptpcd1 with probable mitotic functions. The identification of this new phosphatase suggests the existence of an interacting phosphatase network that controls mammalian mitosis and provides new drug targets for anticancer modalities.