• 제목/요약/키워드: Data missing region

검색결과 51건 처리시간 0.028초

인공신경망기법에 상관계수를 고려한 서울 강우관측 지점 간의 강우보완 및 예측 (Rainfall Adjust and Forecasting in Seoul Using a Artificial Neural Network Technique Including a Correlation Coefficient)

  • 안정환;정희선;박인찬;조원철
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.101-104
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    • 2008
  • In this study, rainfall adjust and forecasting using artificial neural network(ANN) which includes a correlation coefficient is application in Seoul region. It analyzed one-hour rainfall data which has been reported in 25 region in seoul during from 2000 to 2006 at rainfall observatory by AWS. The ANN learning algorithm apply for input data that each region using cross-correlation will use the highest correlation coefficient region. In addition, rainfall adjust analyzed the minimum error based on correlation coefficient and determination coefficient related to the input region. ANN model used back-propagation algorithm for learning algorithm. In case of the back-propagation algorithm, many attempts and efforts are required to find the optimum neural network structure as applied model. This is calculated similar to the observed rainfall that the correlation coefficient was 0.98 in missing rainfall adjust at 10 region. As a result, ANN model has been for suitable for rainfall adjust. It is considered that the result will be more accurate when it includes climate data affecting rainfall.

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텍스쳐 감지를 이용한 화소값 기울기 필터 및 중간값 필터 기반의 비디오 시퀀스 디인터레이싱 (Intensity Gradient filter and Median Filter based Video Sequence Deinterlacing Using Texture Detection)

  • 강근화;구수일;정제창
    • 한국통신학회논문지
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    • 제34권4C호
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    • pp.371-379
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    • 2009
  • 본 논문에서는 텍스쳐 감지를 이용한 화소값 기울기 필터 및 중간값 필터 기반의 비디오 시퀀스 디인터레이싱 알고리듬을 제안한다. 먼저 보간 할 픽셀의 주변 픽셀들을 이용하여 현재 보간 할 영역이 텍스쳐가 존재하는 영역인지 아니면 평탄한 영역인지를 판단한다. 제안하는 알고리듬에서는 보간 할 영역이 평탄한 영역으로 판단되면 중간값 필터를 이용하여 보간을 하고, 텍스쳐 영역으로 판단되면 화소값 기울기 필터를 이용하여 보간을 하게 된다. 그러므로 현재의 보간 할 영역은 두 개의 카테고리로 분류 할 수 있다. 제안하는 알고리듬은 상황에 맞게 적응적으로 보간을 수행하므로 좀 더 선명하고 정확한 영상을 얻을 수 있다. 그리고 여러 가지 CIF 동영상에 대한 실험 결과는 제안하는 알고리듬이 기존의 알고리듬 보다 객관적, 주관적으로 우수함을 보여준다.

Comparing the Performance of 17 Machine Learning Models in Predicting Human Population Growth of Countries

  • Otoom, Mohammad Mahmood
    • International Journal of Computer Science & Network Security
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    • 제21권1호
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    • pp.220-225
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    • 2021
  • Human population growth rate is an important parameter for real-world planning. Common approaches rely upon fixed parameters like human population, mortality rate, fertility rate, which is collected historically to determine the region's population growth rate. Literature does not provide a solution for areas with no historical knowledge. In such areas, machine learning can solve the problem, but a multitude of machine learning algorithm makes it difficult to determine the best approach. Further, the missing feature is a common real-world problem. Thus, it is essential to compare and select the machine learning techniques which provide the best and most robust in the presence of missing features. This study compares 17 machine learning techniques (base learners and ensemble learners) performance in predicting the human population growth rate of the country. Among the 17 machine learning techniques, random forest outperformed all the other techniques both in predictive performance and robustness towards missing features. Thus, the study successfully demonstrates and compares machine learning techniques to predict the human population growth rate in settings where historical data and feature information is not available. Further, the study provides the best machine learning algorithm for performing population growth rate prediction.

3차원 스캔한 인체 샅부위의 결측부위 복원 방법 비교 (Comparison of the Editing Method of Missing Area in 3D Scanned Image of Men's Crotch)

  • 김소영;홍경희
    • 한국의류학회지
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    • 제33권3호
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    • pp.401-409
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    • 2009
  • The shape of crotch area is very important to develop functional clothing as well as other ergonomic goods such as chair or saddle etc. However, it is inevitable that 3D scanned image of crotch would have missing part due to its folded shape including overlapping legs nearby. Therefore, the objectives of this research was to compare reconstruction methods of missing parts at crotch using seven dummies of real men's replicas. Two reconstruction methods adopted were kinds of 'fill- hole' in Rapidform 2004, one was 'smooth' and the other was 'curvature'. Each restored image was compared with the original shape of the dummies. As results, the average distance was 0.66mm between original and 'smooth' treated images and 0.59mm between original and 'curvature' treated, which was not statistically different. Average area of restored crotch region was $8740.04cm^2$ by 'smooth' method and $8405.02cm^2$ by 'curvature' method which is close to the original area of $8413.76cm^2$. Statistical difference was found between images of original and 'smooth' ones$(p=0.04^*)$. However, there was no difference between original and 'curvature' treated images, which indicates that 'curvature' method is more useful to fill the hole compared with 'smooth' method.

INFRASTRUCTURE RISK MANAGEMENT IN PREPAREDNESS OF EXTREME EVENTS

  • Eun Ho Oh;Abhijeet Deshmukh;Makarand Hastak
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.83-90
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    • 2009
  • Natural disasters, such as the recent floods in the Midwest, Hurricane Ike in the Gulf coast region (U.S.), and the earthquake in Sichuan (China), cause severe damage to the infrastructure as well as the associated industries and communities that rely on the infrastructure. The estimated damages due to Hurricane Ike in 2008 were a staggering $27 billion, the third worst in U.S. history. In addition, the worst earthquake in three decades in Sichuan resulted in about 90,000 people dead or missing and $20 billion of the estimated loss. A common observation in the analyses of these natural disaster events is the inadequacy of critical infrastructure to withstand the forces of natural calamities and the lack of mitigation strategies when they occur on the part of emergency-related organizations, industries, and communities. If the emergency-related agencies could identify and fortify the vulnerable critical infrastructure in the preparedness stage, the damage and impacts can be significantly reduced. Therefore, it is important to develop a decision support system (DSS) for identifying region-specific mitigation strategies based on the inter-relationships between the infrastructure and associated industries and communities in the affected region. To establish effective mitigation strategies, relevant data were collected from the affected areas with respect to the technical, social, and economic impact levels. The data analysis facilitated identifying the major factors, such as vulnerability, criticality, and severity, for developing a DSS. Customized mitigation strategies that will help agencies prepare, respond, and recover according to the disaster response were suggested.

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GOSAT 기반의 동북아시아 CO2 분포도에 적용된 크리깅 기법의 비교평가 (Comparative Evaluation among Different Kriging Techniques applied to GOSAT CO2 Map for North East Asia)

  • 최진호;엄정섭
    • 환경영향평가
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    • 제20권6호
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    • pp.879-890
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    • 2011
  • The GOSAT (Greenhouse gases Observing SATellite) data provide new opportunities the most regionally complete and up-to-date assessment of $CO_2$. However, in practice, GOSAT records often suffer from missing data values mainly due to unfavorable meteorological condition in specific time periods of data acquisition. The aim of this research was to identify optimal spatial interpolation techniques to ensure the continuity of $CO_2$ from samples taken in the North East Asia. The accuracy among ordinary kriging (OK), universal kriging (UK) and simple kriging (SK) was compared based on the combined consideration of $R^2$ values, Root Mean Square Error (RMSE), Mean Error (ME) for variogram models. Cross validation for 1312 random sampling points indicate that the (UK) kriging is the best geostatistical method for spatial predictions of $CO_2$ in the East Asia region. The results from this study can be useful for selecting optimal kriging algorithm to produce $CO_2$ map of various landscapes. Also, data users may benefit from a statistical approach that would allow them to better understand the uncertainty and limitations of the GOSAT sample data.

Combination of Brain Cancer with Hybrid K-NN Algorithm using Statistical of Cerebrospinal Fluid (CSF) Surgery

  • Saeed, Soobia;Abdullah, Afnizanfaizal;Jhanjhi, NZ
    • International Journal of Computer Science & Network Security
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    • 제21권2호
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    • pp.120-130
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    • 2021
  • The spinal cord or CSF surgery is a very complex process. It requires continuous pre and post-surgery evaluation to have a better ability to diagnose the disease. To detect automatically the suspected areas of tumors and symptoms of CSF leakage during the development of the tumor inside of the brain. We propose a new method based on using computer software that generates statistical results through data gathered during surgeries and operations. We performed statistical computation and data collection through the Google Source for the UK National Cancer Database. The purpose of this study is to address the above problems related to the accuracy of missing hybrid KNN values and finding the distance of tumor in terms of brain cancer or CSF images. This research aims to create a framework that can classify the damaged area of cancer or tumors using high-dimensional image segmentation and Laplace transformation method. A high-dimensional image segmentation method is implemented by software modelling techniques with measures the width, percentage, and size of cells within the brain, as well as enhance the efficiency of the hybrid KNN algorithm and Laplace transformation make it deal the non-zero values in terms of missing values form with the using of Frobenius Matrix for deal the space into non-zero values. Our proposed algorithm takes the longest values of KNN (K = 1-100), which is successfully demonstrated in a 4-dimensional modulation method that monitors the lighting field that can be used in the field of light emission. Conclusion: This approach dramatically improves the efficiency of hybrid KNN method and the detection of tumor region using 4-D segmentation method. The simulation results verified the performance of the proposed method is improved by 92% sensitivity of 60% specificity and 70.50% accuracy respectively.

상악 선천성 결손과 하악 골격성 제3급 부정교합 경향성을 보이는 환자에게서 CAD-CAM 기법을 이용한 진단과 고정성 보철 수복 증례 보고 (CAD-CAM technique based digital diagnosis and fixed partial denture treatment on maxillary congenital missing teeth with skeletal class III tendency patient: A case report)

  • 오세은;박영범;박재한
    • 대한치과보철학회지
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    • 제60권4호
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    • pp.354-361
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    • 2022
  • 디지털 기술의 발달은 치의학의 큰 변화를 일으키고 있고, 이러한 디지털 워크플로는 보철 치료 영역에서도 다양한 3D 데이터들을 하나로 중첩시켜, 진단과 보철물 제작에 활용되고 있다. 디지털 데이터를 종합하여 형성된 가상 환자에게서 계획된 진단과 보철물의 형성은 기존 통상적인 방법에 비해 보다 더 직관적으로 보철 치료의 결과를 시뮬레이션 할 수 있고, 이로 인해 심미적인 보철 치료의 예측성을 높일 수 있다. 본 증례에서는 디지털 워크플로를 통해 상악 전치부 선천성 결손 부위를 고정성 보철물로 제작하여 기능적, 심미적으로 만족할 만한 임상적 결과를 얻었으므로 이를 보고하는 바이다.

Phylogeography and Population Genetic Structure of Amur Grayling Thymallus grubii in the Amur Basin

  • Ma, Bo;Lui, Tingting;Zhang, Ying;Chen, Jinping
    • Asian-Australasian Journal of Animal Sciences
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    • 제25권7호
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    • pp.935-944
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    • 2012
  • Amur grayling, Thymallus grubii, is an important economic cold freshwater fish originally found in the Amur basin. Currently, suffering from loss of habitat and shrinking population size, T. grubii is restricted to the mountain river branches of the Amur basin. In order to assess the genetic diversity, population genetic structure and infer the evolutionary history within the species, we analysised the whole mitochondrial DNA control region (CR) of 95 individuals from 10 rivers in China, as well as 12 individuals from Ingoda/Onon and Bureya River throughout its distribution area. A total of 64 variable sites were observed and 45 haplotypes were identified excluding sites with gaps/missing data. Phylogenetic analysis was able to confidently predict two subclade topologies well supported by maximum-parsimony and Bayesian methods. However, basal branching patterns cannot be unambiguously estimated. Haplotypes from the mitochondrial clades displayed local homogeneity, implying a strong population structure within T. grubii. Analysis of molecular variance detected significant differences among the different geographical rivers, suggesting that T. grubii in each river should be managed and conserved separately.

ALGEBRAIC CORRECTION FOR METAL ARTIFACT REDUCTION IN COMPUTED TOMOGRAPHY

  • Jeon, Kiwan;Kang, Sung-Ho;Ahn, Chi Young;Kim, Sungwhan
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제18권2호
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    • pp.157-166
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    • 2014
  • If there are metals located in the X-ray scanned object, a point outside the metals has its range of projection angle at which projections passing through the point are disturbed by the metals. Roughly speaking, this implies that attenuation information at the point is missing in the blocked projection range. So conventional projection completion MAR algorithms to use the undisturbed projection data on the boundary of the metaltrace is less efficient in reconstructing the attenuation coefficient in detailed parts, in particular, near the metal region. In order to overcome this problem, we propose the algebraic correction technique (ACT) to utilize a pre-reconstructed interim image of the attenuation coefficient outside the metal region which is obtained by solving a linear system designed to reduce computational costs. The reconstructed interim image of the attenuation coefficient is used as prior information for MAR. Numerical simulations support that the proposed correction technique shows better performance than conventional inpainting techniques such as the total variation and the harmonic inpainting.