• 제목/요약/키워드: Data Heterogeneity

검색결과 613건 처리시간 0.025초

분산 웹 환경에서 이미지 검색을 위한 메타데이타 매핑 (Metadata Mapping for Image Retrieval in Distributed Web Environments)

  • 권은영;나연묵;안철범
    • 한국멀티미디어학회논문지
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    • 제9권7호
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    • pp.782-800
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    • 2006
  • 이미지 메타 데이타는 이미지 데이터의 내용, 구조, 특징 등을 기술하는 데이타를 말한다. 이러한 메타 데이타는 다양한 시스템 환경에서 서로 공유되며 다양한 표준이 존재한다. 이러한 환경에서 사용자가 요구하는 정확한 데이타를 검색하는 것은 매우 중요하다. 본 논문에서는 분산 환경에서 다양한 표준을 가지는 이질적인 이미지 메타데이타의 상호 운용 시스템 구조를 제안하고, 보다 정확하고 효율적인 검색을 위하여 메타데이타 매핑 방법을 이용한 질의 확장 방안을 제안한다. 제안한 매핑 방법에서 비표준 메타데이타를 사용하는 제공자는 MDR내의 기준 표준인 VRA 표준과 매핑된다. 또한, 불필요한 매핑 연산을 줄이고 MDR에 새로운 표준을 쉽게 추가하기 위해서 VRA 표준을 기준으로 표준안간의 매핑을 수행한다. 제안된 확장 질의 방법을 사용하면 다양한 메타데이타 스키마와 표준 간의 관계를 활용하여 검색의 정확도를 높일 수 있다. 본 논문에서 제안된 방법의 유용성을 보이기 위해 시스템 프로토타입을 구현하고 확장 질의 처리에 대한 검객 성능 평가를 수행하였다.

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CAD/CAE 통합을 위한 구조설계 최적화에 관한 연구 (A Study on the Structural Optimization for CAD/CAE Integration)

  • 박창규;양영순;류원선;장범선
    • 한국전산구조공학회논문집
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    • 제22권2호
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    • pp.127-134
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    • 2009
  • 개발단계에 있어서 필수적인 성계 프로세스인 CAD 및 CAE 시스템은 각각 개별적으로 발전되어 왔다. 더구나 제품개발에 있어서 부서나 기업간의 CAD 또는 CAE 시스템의 이질성이나 제품 데이터 표현방법의 차이로 인해 이를 통합하기 위한 부가적인 비용과 개발기간이 발생하기도 한다. 따라서 설계과정에서의 협업을 성공적으로 수행하기 위해서는 제품 개발 초기 단계에서부터 이질적인 CAD와 CAE 등의 관련 시스템을 유기적으로 통합 관리할 수 있어야 한다. 따라서 본 연구에서는 보다 효과적으로 통합관리하고 설계 및 해석도구들의 연계사용을 지원하기 위해 최적설계를 포함한 설계 및 해서시스템을 통합화하는 기법을 제안하고, 보강판 예제를 통해 CATIA를 이용한 CAD와 CAE간의 데이터 전환의 문제점을 극복하는 것을 보여줌으로서 이 기법의 타당성을 보여주고자 한다. 이와 아울러 최적화 과정을 수행함에 있어서 CAE 프로세스는 구조 최적화 과정에 있어서 하나의 필수적인 부분임을 확인할 수 있었다.

울릉분지 시추공 분석 자료를 이용한 가스하이드레이트 함유층의 3차원 공간 물성 분포 추정 (3D Spatial Distribution Modeling for Petrophysical Property of Gas Hydrate-Bearing Sediment using Well Data in Ulleung Basin)

  • 이동건;신효진;임종세
    • 에너지공학
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    • 제22권2호
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    • pp.156-168
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    • 2013
  • 이 연구에서는 2007년, 2010년에 수행한 울릉분지 1, 2차 시추 지역의 시추공(UBGH1-1, UBGH1-4, UBGH1-9, UBGH1-10, UBGH1-14, UBGH2-2-1, UBGH2-2-2, UBGH2-6, UBGH2-9, UBGH2-10, UBGH2-11)에서 취득한 물리검층 및 코어분석 자료로 추정한 가스하이드레이트 함유층 주요 물성 자료를 활용하여 불균질성을 반영할 격자 수준의 3차원 공간 분포 모델링을 수행하였다. 가스하이드레이트 함유층 내 퇴적상의 공간 분포 추정을 위하여 퇴적상 추정 자료를 각 시추공별로 3차원 격자셀에 입력하고 순차지표시뮬레이션으로 3차원 분포를 모델링하였다. 가스하이드레이트 함유층의 공극률과 가스하이드레이트포화율은 퇴적상 분포 모델을 기반으로 순차가우스시뮬레이션을 통해 3차원 공간 물성 분포를 추정하였다.

The Impact of International Integration on the Inequality of Income between Rural and Urban Areas in Vietnam

  • NGUYEN, Thi Thanh Huyen;NGUYEN, Thi Thu Hien;NGUYEN, Thi Le Hang;NGUYEN, Van Cong
    • The Journal of Asian Finance, Economics and Business
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    • 제7권3호
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    • pp.277-287
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    • 2020
  • The study examines the impact of international integration on Vietnam's rural and urban income inequalities using the regression model. The data used for this study is based on the results of the Vietnam Household Living Standards survey from 2008 to 2016 of the General Statistics Office. These surveys conducted nationwide with a sample size of 46,995 households in 3,133 communes/wards which were representative at national, regional, urban, rural and provincial levels. The level of international economic integration used in the study is the proportion of import and export turnover of GDP, the proportion of FDI and GDP by province. Due to the heterogeneity and unobservableness of the single observant in the data set, we selected the models of random and fixed effects. The research results show that during the economic integration process, the Export/GDP factor is negatively related to income inequality. The remaining factors (GDP per capita, FDI/GDP, Educational level of households, Percentage of internet users, Aggregation of foreign cash inflow and GDP of the province) are all positively related to income inequality. The findings help assess the impact of international integration on rural-urban income inequality, but also provides a concrete basis to help policymakers address income inequality in the integration process.

Helicobacter pylori Infection and the Risk of Colorectal Adenoma and Adenocarcinoma: an Updated Meta-analysis of Different Testing Methods

  • Chen, Yao-Sheng;Xu, Song-Xin;Ding, Yan-Bing;Huang, Xin-En;Deng, Bin
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7613-7619
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    • 2013
  • Background and Aims: Helicobacter pylori infection may be associated with an increased risk of colorectal carcinoma. However, as most studies on this subject were relatively small in size and differed at least partially in their designs, their results remain controversial. In this study, we aimed to carry out a meta-analysis to evaluate the potential association of H. pylori infection with colorectal adenoma and adenocarcinoma risk, covering all of the different testing methods. Methods: We conducted a search in PubMed, Medline, EBSCO, High Wire Press, OVID, and EMBASE covering all published papers up to March 2013. According to the established inclusion criteria, essential data were then extracted from the included studies and further analyzed by a systematic meta-analysis. Odds ratios were employed to evaluate the relationship between H. pylori infection and the risk of colorectal neoplasms. Results: Twenty-two studies were included, and the odds ratio for the association between H. pylori infection and colorectal cancer was 1.49 (95% confidence interval 1.30-1.72). No statistically significant heterogeneity was observed. Publication bias was ruled out. Conclusion: The pooled data suggest H. pylori infection indeed increases the risk of colorectal adenoma and adenocarcinoma.

단백질 상호작용 네트워크를 통한 유전체 단위반복변이와 트랜스유전자 발현과의 연관성 분석 (Genome-Wide Association Study between Copy Number Variation and Trans-Gene Expression by Protein-Protein Interaction-Network)

  • 박치현;안재균;윤영미;박상현
    • 정보처리학회논문지D
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    • 제18D권2호
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    • pp.89-100
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    • 2011
  • 인간 유전체에 존재하는 유전적 구조 변이(genetic structural variation) 중 하나인 유전체 단위반복변이(Copy Number Variation, CNV)은 유전자의 기능 발현과 밀접한 관련이 있다. 특히 특정 유전 질병이 있는 사람들을 대상으로 CNV와 유전자발현의 관계를 밝히는 연구가 계속 진행되고 있지만, 정상인 유전체에 대한 CNV의 기능적 분석은 아직 활발히 이루어지고 있지 않다. 본 논문에서는 다수의 정상인 샘플에서 찾아낸 공통된 CNV에 대하여 유전자들과의 기능적 관계를 유전자의 분자적 위치와 상관없이 밝힐 수 있는 분석 방법을 제시한다. 이를 위해 서로 다른 이질적인 생물학데이터를 통합하는 방법을 제시하고 공통된 CNV와 유전자와의 연관성을 분자적 위치와 상관없이 계산할 수 있는 새로운 방법을 제시한다. 제안된 방법의 유의성을 보이기 위해서 유전자 온톨로지 (Gene Ontology) 데이터베이스를 이용한 다양한 검증 실험들을 수행하였다. 실험결과 새롭게 제안된 연관성 측정방법은 유의성이 있으며 공통된 CNV와 강한 연관성을 갖는 유전적 기능의 후보들을 시스템적으로 제시할 수 있는 것으로 나타났다.

Functional PstI/RsaI Polymorphisms in the CYP2E1 Gene among South Indian Populations

  • Lakkakula, Saikrishna;Maram, Rajasekhar;Munirajan, Arasambattu Kannan;Pathapati, Ram Mohan;Visweswara, Subrahmanyam Bhattaram;Lakkakula, Bhaskar V.K.S.
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권1호
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    • pp.179-182
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    • 2013
  • Human cytochrome P4502E1 (CYP2E1) is a well-conserved xenobiotic-metabolizing enzyme expressed in liver, kidney, nasal mucosa, brain, lung, and other tissues. CYP2E1 is inducible by ethanol, acetone, and other low-molecular weight substrates and may mediate development of chemically-mediated cancers. CYP2E1 polymorphisms alter the transcriptional activity of the gene. This study was conducted in order to investigate the allele frequency variation in different populations of Andhra Pradesh. Two hundred and twelve subjects belonging to six populations were studied. Genotype and allele frequency were assessed through TaqMan allelic discrimination (rs6413419) and polymerase chain reaction-sequencing (-1295G>C and -1055C>T) after DNA isolation from peripheral leukocytes. The data were compared with other available world populations. The SNP rs6413419 is monomorphic in the present study, -1295G>C and -1055C>T are less polymorphic and followed Hardy-Weinberg equilibrium in all the populations studied. The -1295G>C and -1055C>T frequencies were similar and acted as surrogates in all the populations. Analysis of HapMap populations data revealed no significant LD between these markers in all the populations. Low frequency of $CYP2E1^*c2$ could be useful in the understanding of south Indian population gene composition, alcohol metabolism, and alcoholic liver disease development. However, screening of additional populations and further association studies are necessary. The heterogeneity of Indian population as evidenced by the different distribution of $CYP2E1^*c2$ may help in understanding the population genetic and evolutionary aspects of this gene.

Robotic versus Laparoscopic Gastrectomy for Gastric Carcinoma: a Meta-Analysis of Efficacy and Safety

  • Hu, Li-Dong;Li, Xiao-Fei;Wang, Xiu-Yue;Guo, Tian-Kang
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권9호
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    • pp.4327-4333
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    • 2016
  • Purpose: To systematically review efficacyand safety of robotic gastrectomy (RG) compared with conventional laparoscopic gastrectomy (LG) for gastric carcinoma. Materials and Methods: A systematic literature search was carried out using PubMed, Cochrane Library, CBM, CNKI, WanFang, VIP and other sources like relevant references to obtain comparative studies assessing the effectiveness and safety between RG and LG published between 2013 and 2016. Then the literature was screened and the data were extracted by 2 independent reviewers. The quality of the literature was assessed, and the data analyzed using Stata/SE 14 software. Fixed effects or random effects models wereapplied according to heterogeneity. Results: A total of 12 non-randomized observational clinical studies involving 3,580 patients were included, of which 1,096 had undergone RG and 2,484 had received LG. The results of the meta-analysis showed in terms of effectiveness, RG was associated with less blood loss, less time to first flatus and greater number of harvested lymph nodes, but there were no significant differences in proximal and distal resection margins, compared with LG. In terms of efficiency, RG was associated with shorter hospital stay, but longer operative time. In terms of safety, there were no statistically significant differences in complications, mortality and conversions between RG and LG. Conclusions: RG can achieve comparable or better short-term and radical effects than LG, with respect to effectiveness, efficiency and safety in treatment of gastric carcinoma. Future studies involving RG should focus on decreasing operative time and reducing cost. Moreover, there is a need for randomized controlled trials comparing the two techniques with long-term follow-up.

Experimental In-Vivo Models Used in Fat Grafting Research for Volume Augmentation in Soft Tissue Reconstruction

  • Lujan-Hernandez, Jorge;Appasani, Raghu;Sullivan, Kylee;Siegel-Reamer, Leah;Lalikos, Janice F.
    • Archives of Plastic Surgery
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    • 제44권5호
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    • pp.361-369
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    • 2017
  • As the popularity of fat grafting research increases, animal models are being used as the source of pre-clinical experimental information for discovery and to enhance techniques. To date, animal models used in this research have not been compared to provide a standardized model. We analyzed publications from 1968-2015 to compare published accounts of animal models in fat grafting research. Data collected included: species used, graft characteristics (donor tissue, recipient area, amount injected, injection technique), time of sacrifice and quantification methods. Mice were most commonly used (56% of studies), with the "athymic nude" strain utilized most frequently (44%). Autologous fat was the most common source of grafted tissue (52%). Subcutaneous dorsum was the most common recipient site (51%). On average, $0.80{\pm}0.60mL$ of fat was grafted. A single bolus technique was used in 57% of studies. Fat volume assessment was typically completed at the end of the study, occurring at less than 1 week to one year. Graft volume was quantified by weight (63%), usually in conjunction with another analysis. The results demonstrate the current heterogeneity of animal models in this research. We propose that the research community reach a consensus to allow better comparison of techniques and results. One example is the model used in our laboratory and others; this model is described in detail. Eventually, larger animal models may better translate to the human condition but, given increased financial costs and animal facility capability, should be explored when data obtained from small animal studies is exhausted or inconclusive.

Comparing Plant Species Diversity of Mountainous Deserts - Successes and Pitfalls

  • Van Etten, Eddie J.B.
    • The Korean Journal of Ecology
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    • 제27권2호
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    • pp.79-86
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    • 2004
  • An extensive study of the vegetation characteristics of the Hamersley Ranges, a mountainous desert area of north-west Australia, facilitated the comparison of plant species diversity measures with mountainous deserts of other parts of the world. Alpha diversity was defined as the number of species co-existing at local scales and was found to average 18 species per 0.1 ha for the Hamersley Ranges. This was found to be similar to seven other mountainous deserts in North and South America, and southern Africa. Variation in alpha diversity between these deserts was found to considerably lower than within deserts, suggesting that local processes control species richness at local scales. Beta diversity, defined here as turnover in species composition at various spatial scales, can be measured in many ways. For the Hamersley Ranges, Wilson's β ranged from 1.2 to 1.6 for five sites along a topographic gradient, whereas Whittaker's β between different plant communities was found to average 0.93. Comparable data was not found for other desert areas, but comparisons to non-desert areas suggest beta diversity within landscapes is relatively high and is likely to reflect the considerable landform heterogeneity of the Hamersley Ranges. 55∼70% of species were shared between different landscapes of the Hamersley Ranges; comparisons to other regions suggest beta diversity at this scale is relatively low. Gamma diversity, the number of species over large spatial extents, was successfully compared using regression analysis of the log-log species - area relationship. This revealed that the northern Sonoran desert has significantly less species than the Nama (inland) Karoo and Hamersley Ranges over medium spatial extents, but species numbers were similar at a regional scale. Several constraints to the valid comparison of species diversity were identified, including lack of standardisation of sampling techniques, the wide range of measures employed, general lack of published data, and the influence of the various components of spatial scale on most diversity measures. Recommendations on how to improve future comparative work are provided.