2,722 research outputs found
A forecasting of stock trading price using time series information based on big data
Big data is a large set of structured or unstructured data that can collect, store, manage, and analyze data with existing database management tools. And it means the technique of extracting value from these data and interpreting the results. Big data has three characteristics: The size of existing data and other data (volume), the speed of data generation (velocity), and the variety of information forms (variety). The time series data are obtained by collecting and recording the data generated in accordance with the flow of time. If the analysis of these time series data, found the characteristics of the data implies that feature helps to understand and analyze time series data. The concept of distance is the simplest and the most obvious in dealing with the similarities between objects. The commonly used and widely known method for measuring distance is the Euclidean distance. This study is the result of analyzing the similarity of stock price flow using 793,800 closing prices of 1,323 companies in Korea. Visual studio and Excel presented calculate the Euclidean distance using an analysis tool. We selected “000100” as a target domestic company and prepared for big data analysis. As a result of the analysis, the shortest Euclidean distance is the code “143860” company, and the calculated value is “11.147”. Therefore, based on the results of the analysis, the limitations of the study and theoretical implications are suggested
Programmable spectral shaping to improve the measurement precision of frequency comb mode-resolved spectral interferometric ranging
Comb-mode resolved spectral domain interferometry (CORE-SDI), which is
capable of measuring length of kilometers or more with precision on the order
of nanometers, is considered to be a promising technology for next-generation
length standards, replacing laser displacement interferometers. In this study,
we aim to improve the measurement precision of CORE-SDI using programmable
spectral shaping. We report the generation of effectively broad and symmetric
light sources through the programmable spectral shaping. The light source used
here was generated by the spectrally-broadened electro-optic comb with a
repetition rate of 17.5 GHz. Through the programmable spectral shaping, the
optical spectrum was flattened within 1 dB, resulting in a square-shaped
optical spectrum. As a result, the 3-dB spectral width was extended from 1.15
THz to 6.7 THz. We performed a comparison between the measurement results of
various spectrum shapes. We confirmed an improvement in the measurement
precision from 69 nm to 6 nm, which was also corroborated by numerical
simulations. We believe that this study on enhancing the measurement precision
of CORE-SDI through the proposed spectral shaping will make a significant
contribution to reducing the measurement uncertainty of future CORE-SDI
systems, thereby advancing the development of next-generation length standards.Comment: 22 pages, 10 figure
Lightweight HDR Camera ISP for Robust Perception in Dynamic Illumination Conditions via Fourier Adversarial Networks
The limited dynamic range of commercial compact camera sensors results in an
inaccurate representation of scenes with varying illumination conditions,
adversely affecting image quality and subsequently limiting the performance of
underlying image processing algorithms. Current state-of-the-art (SoTA)
convolutional neural networks (CNN) are developed as post-processing techniques
to independently recover under-/over-exposed images. However, when applied to
images containing real-world degradations such as glare, high-beam, color
bleeding with varying noise intensity, these algorithms amplify the
degradations, further degrading image quality. We propose a lightweight
two-stage image enhancement algorithm sequentially balancing illumination and
noise removal using frequency priors for structural guidance to overcome these
limitations. Furthermore, to ensure realistic image quality, we leverage the
relationship between frequency and spatial domain properties of an image and
propose a Fourier spectrum-based adversarial framework (AFNet) for consistent
image enhancement under varying illumination conditions. While current
formulations of image enhancement are envisioned as post-processing techniques,
we examine if such an algorithm could be extended to integrate the
functionality of the Image Signal Processing (ISP) pipeline within the camera
sensor benefiting from RAW sensor data and lightweight CNN architecture. Based
on quantitative and qualitative evaluations, we also examine the practicality
and effects of image enhancement techniques on the performance of common
perception tasks such as object detection and semantic segmentation in varying
illumination conditions.Comment: Accepted in BMVC 202
Cosimulation of MBD (Multi Body Dynamics) and DEM of many spheres using GPU technology
In this paper, dynamic simulation model which have many sphere particles and MBD (Multi Body Dynamics) entities, i.e. bodies, joints, forces, is built and simulated. Many sphere particles are solved with DEM (Discrete Element Method) and simulated with GPU technology. Fast algorithm is applied to calculate hertzian contact forces between many sphere particles (from 100,000 to 1,000,000) and NVIDIA’s CUDA is used to accelerate the calculation. Explicit integration method is applied to solve the many spheres. MBD (Multi Body Dynamics) entities are simulated with recursive formulation. Constraints are reduced by recursive formulation and implicit generalized alpha method is applied to solve dynamic model. Many sphere particles and MBD (Multi Body Dynamics) entities are co-simulated within commercial software RecurDyn. The interaction forces between many sphere particles and rigid body mesh are calculated and applied to each body to simulate two parts simultaneously. These models are built and simulated; fork lifter with sand model, oil in oil tank model, oil filled engine system and water filled washing machine model. All models are simulated with NVIDIA’s GPU and the result is shown
The diameter of the world wide web
Despite its increasing role in communication, the world wide web remains the
least controlled medium: any individual or institution can create websites with
unrestricted number of documents and links. While great efforts are made to map
and characterize the Internet's infrastructure, little is known about the
topology of the web. Here we take a first step to fill this gap: we use local
connectivity measurements to construct a topological model of the world wide
web, allowing us to explore and characterize its large scale properties.Comment: 5 pages, 1 figure, updated with most recent results on the size of
the ww
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