• Title/Summary/Keyword: RAW data

Search Result 2,582, Processing Time 0.031 seconds

Ocean Surface Current Retrieval Using Doppler Centroid of ERS-1 Raw SAR Data

  • Kim Ji-Eun;Kim Duk-jin;Moon Wooil M.
    • Proceedings of the KSRS Conference
    • /
    • 2004.10a
    • /
    • pp.590-593
    • /
    • 2004
  • Extraction of ocean surface current velocity offers important physical oceanographic parameters especially on understanding ocean environment. Although Remote Sensing techniques were highly developed, the investigation of ocean surface current using Synthetic Aperture Radar (SAR) is not an easy task. This paper presents the results of ocean surface current observation using Doppler Centroid of ERS-1 SAR data obtained off the coast of Korea peninsula. We employed the concept, in which Doppler frequency shift and the ocean surface current are closely related, to evaluate ocean surface current. Moving targets cause Doppler frequency shift of the back scattered radar waves of SAR, thus the line-of-sight velocity component of the scatters can be evaluated. The Doppler frequency shift can be measured by estimating the difference between Doppler Centroid of raw SAR data and reference Doppler Centroid. Theoretically, the Doppler Centroid is zero; however, squinted antenna which is affected by several physical factors causes Doppler Centroid to be nonzero. The reference Doppler Centroid can be obtained from measurements of sensor trajectory, attitude and Earth model. The estimated Doppler Centroid was compensated by considering the accurate attitude estimation of ERS-1 SAR. We could verify the correspondence between the estimated ocean surface current and observed in-situ data in the error bound.

  • PDF

Cloud Cover Analysis from the GMS/S-VISSR Imagery Using Bispectral Thresholds Technique (GMS/S-VISSR 자료로부터 Bispectral Thresholds 기법을 이용한 운량 분석에 관하여)

  • 서명석;박경윤
    • Korean Journal of Remote Sensing
    • /
    • v.9 no.1
    • /
    • pp.1-19
    • /
    • 1993
  • A simple bispectral threshold technique which reflects the temporal and spatial characteristics of the analysis area has been developed to classify the cloud type and estimate the cloud cover from GMS/S-VISSR(Stretched Visible and Infrared Spin Scan Radiometer) imagery. In this research, we divided the analysis area into land and sea to consider their different optical properties and used the same time observation data to exclude the solar zenith angle effects included in the raw data. Statistical clear sky radiance(CSRs) was constructed using maximum brightness temperature and minimum albedo from the S-VISSR imagery data during consecutive two weeks. The CSR used in the cloud anaysis was updated on the daily basis by using CSRs, the standard deviation of CSRs and present raw data to reflect the daily variation of temperature. Thresholds were applied to classify the cloud type and estimate the cloud cover from GMS/S-VISST imagery. We used a different thresholds according to the earth surface type and the thresholds were enough to resolve the spatial variation of brightness temperature and the noise in raw data. To classify the ambiguous pixels, we used the time series of 2-D histogram and local standard deviation, and the results showed a little improvements. Visual comparisons among the present research results, KMA's manual analysis and observed sea level charts showed a good agreement in quality.

Blockchain Based Data-Preserving AI Learning Environment Model for Cyber Security System (AI 사이버보안 체계를 위한 블록체인 기반의 Data-Preserving AI 학습환경 모델)

  • Kim, Inkyung;Park, Namje
    • The Journal of Korean Institute of Information Technology
    • /
    • v.17 no.12
    • /
    • pp.125-134
    • /
    • 2019
  • As the limitations of the passive recognition domain, which is not guaranteed transparency of the operation process, AI technology has a vulnerability that depends on the data. Human error is inherent because raw data for artificial intelligence learning must be processed and inspected manually to secure data quality for the advancement of AI learning. In this study, we examine the necessity of learning data management before machine learning by analyzing inaccurate cases of AI learning data and cyber security attack method through the approach from cyber security perspective. In order to verify the learning data integrity, this paper presents the direction of data-preserving artificial intelligence system, a blockchain-based learning data environment model. The proposed method is expected to prevent the threats such as cyber attack and data corruption in providing and using data in the open network for data processing and raw data collection.

Anti-inflammatory Effects of Complex Extract including Eucommia ulmoides in LPS-induced RAW 264.7 Cells

  • Ryu, Hwa Yeon;Lee, Hyun;Kong, Hae Jin;Kang, Jae Hui
    • Journal of Acupuncture Research
    • /
    • v.36 no.4
    • /
    • pp.256-263
    • /
    • 2019
  • Background: The purpose of this study was to investigate the anti-inflammatory response of lipopolysaccharide (LPS) activated macrophages (RAW 264.7 murine cell line) to JCE003 which is an extract including Eucommia ulmoides, Juglans regia, Eleutherococcus senticosus, and Zingiber officinale. Methods: An MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide] assay was performed to analyze the survival rate of RAW 264.7 cells. The production of nitric oxide and pro-inflammatory cytokines (IFN-${\gamma}$, TNF-${\alpha}$, IL-$1{\beta}$, IL-6) in LPS-induced RAW 264.7 cells was measured by enzyme-linked immunosorbent assay. mRNA expression levels of pro-inflammatory cytokines (IFN-${\gamma}$, TNF-${\alpha}$, IL-$1{\beta}$, and IL-6) were analyzed by quantitative polymerase chain reaction analysis. Results: Exposure of LPS-activated RAW 264.7 cells to JCE003 was not cytotoxic up to $400{\mu}g/mL$, but cell survival was statistically significantly decreased at $800{\mu}g/mL$ (p < 0.001). Nitric oxide production was not markedly lowered in LPS-activated RAW 264.7 cells by exposure to JCE003 (10, 50, 100, 200, 400, $800{\mu}l/mL$) compared with the Control group. In addition, JCE003 reduced the production of TNF-${\alpha}$ in LPS-induced RAW 264.7 cells at $400{\mu}g/mL$ (p < 0.05), but IFN-${\gamma}$ and TNF-${\alpha}$ mRNA expression in LPS-induced RAW 264.7 cells was decreased at 100, 200, and $400{\mu}g/mL$ JCE003 (p < 0.01). Conclusion: These results suggest that JCE003 inhibited the expression and production of pro-inflammatory cytokines in LPS-activated RAW 264.7 cells. The findings of this study provide basic data for the development of new Korean medicine anti-inflammatory drugs.

XML Based Heterogeneous Sensory Data Management System (XML 기반의이기종 센서 데이터 관리 시스템)

  • Nawaz, Waqas;Fahim, Muhammad;Lee, Sung-Young;Lee, Young-Koo
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2011.06b
    • /
    • pp.305-306
    • /
    • 2011
  • The Wireless sensor networks (WSN) continuously generates large volumes of raw data which own natural heterogeneity. These networks are normally application specific with no sharing or reusability of sensor data among applications. In order for applications and services to be developed independently of particular network, sensor data need to be available in more standardized form. In this paper, we propose Architecture for Sensory data management. This Extensible Markup Language (XML) oriented architecture allows the sensor data to be understood and processed in a meaningful way by a variety of applications with different purposes. We developed a middle layer which performs transformation on raw sensory data to XML and vice versa.

Application of Wavelet Transform for Correlation Analysis between Water Quality and Rainfall Data (수질 및 강우자료의 상관분석을 위한 웨이블렛 변환의 적용)

  • Jin, Young Hoon;Oh, Chang Ryol;Park, Sung Chun
    • Journal of Korean Society on Water Environment
    • /
    • v.22 no.5
    • /
    • pp.831-837
    • /
    • 2006
  • The present study applies wavelet transform for the extraction of various periodicities which are included in TOC and pH time series of water quality and rainfall data. The primary objective of the present study is to detect the relationships between the respective data through the correlation analysis using the approximation components which are decomposed by wavelet transform. The results reveal the approximation components of TOC and pH in the 5th level of wavelet transform can explain more than 99% of the whole energy for the raw data respectively and there are considerably high correlation between the approximation components of the respective data used for the study even through no significant correlation between the raw data has been detected.

Method for Eliminating Spurious Signal from Deramped SAR Raw Data (Deramped SAR 원시데이터에서 효율적인 Spurious 신호 제거 기법)

  • Lim, Byoung-Gyun;Ryu, Sang-Bum
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.27 no.3
    • /
    • pp.239-245
    • /
    • 2016
  • Deramping technique has been widely used to acquire high resolution SAR(Synthetic Aperture Radar) images for the advantage of the data size and the processing time. However, unwanted spurious signals caused by SAR hardware can be leaked in the process of converting into a digital signal through the ADC(Analog-Digital Converter) and added in a echo signal. These tones make image quality degrade significantly. In order to solve this problem, the unwanted tones need to be detected by analysing the characteristic of the noise tone and then effectively removed from raw data. In this paper, we propose a method for efficiently removing noise tone on the raw data based on the characteristic of spurious signals.

Raw Fish Consuming Behavior Related to Liver Fluke Infection among Populations at Risk of Cholangiocarcinoma in Nakhon Ratchasima Province, Thailand

  • Chavengkun, Wasugree;Kompor, Pontip;Norkaew, Jun;Kujapun, Jirawoot;Pothipim, Mali;Ponphimai, Sukanya;Kaewpitoon, Soraya J;Padchasuwan, Natnapa;Kaewpitoon, Natthawut
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.6
    • /
    • pp.2761-2765
    • /
    • 2016
  • Opisthorchiasis is a health problem in rural communities of Thailand, particularly in the northeast and north regions. Therefore, this study aimed to investigate raw fish consuming behavior related to liver fluke infection among the population at risk for opisthorchiasis and cholangiocarcinoma (CCA). A cross-sectional descriptive study was conducted in Meuang Yang district, Nakhon Ratchasima province, northeast Thailand, between June and October 2015. Participants were screened for CCA, and samples who had a high score of CCA risk were purposively selected. A predesigned questionnaire was utilized to collect the data from all participants. $X^2-test$ was used for analysis of associations between demographic data and raw fish consumption. The results revealed that participants had past histories of stool examination (33.0%), liver fluke infection (21.0%), praziquantel use (24.0%), raw fish consumption (78.0%), relatives family consuming raw fish (73.0%), and relatives family with CCA (3.0%). Participants consumed several dished related to liver fluke infection, mainly raw fermented fish (13.0%), under smoked catfish (5.00%), raw pickled fish (4.00%), and raw spicy minced fish salad (3.00%). The most common types of cyprinoid fish were Barbodes gonionotus (39%), Hampala dispar (38%), Puntius brevis (37%), Cyclocheilichthys armatus (33%), Puntioplites proctozysron (32%), and Luciosoma bleekeri (30%), respectively. Participants had a low level of knowledge (mean=3.79, SD=0.74), moderate attitude (mean=7.31, SD=7.31) and practice (mean=38.64, SD=6.95) regarding liver fluke prevention and control. Demographic variables like age (>36 years old; $X^2-test=17.794$, p-value=0.001), education (primary school; $X^2-test=18.952$, p-value=0.001), marital status (married; $X^2-test=12.399$, p-value=0.002), and income (<5,000 baht; $X^2-test=27.757$, p-value=0.015) were significantly associated with raw fish consumption. This result indicates that the population had risk consumption for liver fluke infection particularly of various cyprinoid fishes that are $2^{nd}$ intermediate hosts. Therefore, health education is required to improve their behavior.

REDUCING X-ray BRIGHT GALAXY GROUPS IMAGES WITH THELI PIPELINE

  • NIKAKHTAR, FARNIK
    • Publications of The Korean Astronomical Society
    • /
    • v.30 no.2
    • /
    • pp.671-673
    • /
    • 2015
  • Before analyzing the images taken with a Mosaic CCD imager, the images have to reach a state which can be used for further scientific analysis. The transformation of raw images into calibrated images is called data reduction. Transforming HEavely Light into Images (THELI) is a nearly fully automated reduction pipeline software (Erben et al., 2005). This pipeline works on raw images to remove instrumental signatures, mask unwanted signals, and perform photometric and astrometric calibration. Finally THELI constructs a deep co-added mosaic image and a weight map. In this poster, THELI data reduction procedures will be reviewed and the reduction process for raw images of seven X-ray bright groups, extracted from GEMS groups (Osmond & Ponman, 2004) obtained by the Wide Field Imager (WFI) mounted on MPG/ESO telescope at La Silla in March 2006 will be discussed.

Traffic Extraction and Verification for Attack Detection Experimentation (공격탐지 실험을 위한 네트워크 트래픽 추출 및 검증)

  • Park, In-Sung;Lee, Eun-Young;Oh, Hyung-Geun;Lee, Do-Hoon
    • Convergence Security Journal
    • /
    • v.6 no.4
    • /
    • pp.49-57
    • /
    • 2006
  • Firewall to block a network access of unauthorized IP system and IDS (Intrusion Detection System) to detect malicious code pattern to be known consisted the main current of the information security system at the past. But, with rapid growth the diffusion speed and damage of malicious code like the worm, study of the unknown attack traffic is processed actively. One of such method is detection technique using traffic statistics information on the network viewpoint not to be an individual system. But, it is very difficult but to reserve traffic raw data or statistics information. Therefore, we present extraction technique of a network traffic Raw data and a statistics information like the time series. Also, We confirm the validity of a mixing traffic and show the evidence which is suitable to the experiment.

  • PDF