Wyniki wyszukiwania - Biblioteka Nauki

1

Modeling of Ionospheric Delay for SBAS Using Spherical Harmonics Functions

100%

Han D. , Yun H. , Kee C.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2013

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tom Vol. 7, no. 2

205--209

EN

In SBAS (satellite‐based augmentation system), it is important to estimate ionospheric delay accurately to guarantee userʹs accuracy and integrity. Grid based ionospheric models are generally used to estimate ionospheric delay for SBAS. In grid based model, SBAS broadcasts vertical ionospheric delays at the grid point, and users get their ionospheric delay by interpolating those values. Ionospheric model based on spherical harmonics function is another method to estimate ionospheric delay. This is a function based approach and spherical harmonics function is a 2‐D fourier series, containing the product of latitude dependent associated Legendre functions and the sum of the longitude dependent sine and cosine terms. Using ionospheric delay measurements, coefficients for each spherical harmonics functions are estimated. If these coefficients are known, user can reconstruct ionospheric delay. In this paper, we consider the spherical harmonics based model and propose a ionospheric delay estimation strategy for SBAS that can be used to mitigate ionospheric delay estimation error, especially in storm condition. First, coefficients are estimated under initial order and degree. Then residual errors for each measurement are modeled by higher order and degree terms, then coefficients for these terms are estimated. Because SBAS message capacity is limited, in normal condition, initial order terms are only used to estimate ionospheric delay. If ionospheric storm is detected and there is need to mitigate the error, higher order terms are also used and error can be decreased. To compare the accuracy of spherical harmonics based model with grid based model, some post‐processing test results are presented. Raw observation data is obtained from RINEX format and the root mean square(RMS) and max value of residual errors are presented.

2

Korean WA-DGNSS User Segment Software Design

88%

Shah S. T. , Choi W. S. , Han W. Y. , Yun H. , Kee C.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2013

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tom Vol. 7, no. 1

69--74

EN

Korean WA‐DGNSS is a large scale research project funded by Ministry of Land, Transport and Maritime Affairs Korea. It aims to augment the Global Navigation Satellite System by broadcasting additional signals from geostationary satellites and providing differential correction messages and integrity data for the GNSS satellites. The project is being carried out by a consortium of universities and research institutes. The research team at Electronics and Telecommunications Research Institute is involved in design and development of data processing softwares for wide area reference station and user segment. This paper focuses on user segment software design. Korean WA‐DGNSS user segment software is designed to perform several functions such as calculation of pseudorange, ionosphere and troposphere delays, application of fast and slow correction messages, and data verification. It is based on a layered architecture that provides a model to develop flexible and reusable software and is divided into several independent, interchangeable and reusable components to reduce complexity and maintenance cost. The current version is designed to collect and process GPS and WADGNSS data however it is flexible to accommodate future GNSS systems such as GLONASS and Galileo.

3

Czy obecność pokarmu oraz sposób dawkowania mogą wpływać na skuteczność cimikoksybu u psów?

75%

Lebkowska-Wieruszewska B. , Kowalski C. J. , Kim T. W. , Owen H. , Yun H. , Giorgi M.

Magazyn Weterynaryjny

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2016

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tom 25

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nr 03

4

Wpływ pokarmu oraz sposobu dawkowania na farmakokinetykę cymikoksybu u psów

75%

Lebkowska-Wieruszewska B. , Kowalski C. J. , Kim T. W. , Owen H. , Yun H. , Giorgi M.

Medycyna Weterynaryjna

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2015

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tom 71

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nr 10

EN

Cimicoxib (CX) is a new non-steroidal anti-inflammatory drug from the “coxib” family, designed for dogs. In the available literature there is little information on the pharmacokinetics of CX. The aim of this study was to evaluate the effect of food intake on the pharmacokinetic characteristics of cimicoxib. Additionally, the pharmacokinetic profile after the administration of precise doses of CX (2 mg/kg b.w.) and an approximate dose (i.e. 80 mg tablet for animals of about 40 kg) were estimated. CX concentrations were determined by a HPLC validated method. The results of pharmacokinetic analysis were similar in both studies, regardless of the dose and the degree of filling of the gastrointestinal tract (fasted, fed). In addition, we estimated the duration of the minimum effective concentration (MEC), which turned out to be similar for all the concentrations tested. The results show that neither small variations in dosage nor the presence of food in the gastrointestinal tract change the therapeutic efficacy of the analgesic in terms of its blood concentration.

5

Flexible Software Design for Korean WA-DGNSS Reference Station

75%

Choi W. S. , Chhattan S. S. , Kye J. E. , Han W. Y. , Yun H. , Kee C.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2013

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tom Vol. 7, no. 1

75--78

EN

In this paper, we describe the software design results of WA‐DGNSS reference station that will be constructed in Korea in the near future. Software design of the WRS (Wide area Reference Station) is carried out by applying object oriented software methodology in order to provide flexibilities: easy of model change (namely ionospheric delay model etc) and system addition (Galileo, GLONASS in addition to GPS etc). Software design results include the use case diagrams for the functions to be executed, the architecture diagram showing components and their relationships, the activity diagrams of behaviors and models among them, and class diagrams describing the attribute and operation.

6

Spatial and temporal changes of osteopontin in oxygen-glucose-deprived hippocampal slice cultures

63%

Lee J.-Y. , Choi J.-S. , Choi J.-Y. , Shin Y.-J. , Yun H. , Cha J.-H. , Chun M.-H. , Lee M.-Y.

Acta Neurobiologiae Experimentalis

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2010

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tom 70

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nr 1

EN

We have examined the temporal changes and cellular localization of osteopontin (OPN) mRNA and protein in organotypic hippocampal slice cultures subjected to ischemia-like oxygen–glucose deprivation (OGD). The sequential induction pattern of OPN expression occurred in a time- and cell-dependent manner in hippocampal slice cultures after OGD. The early response consisted of neuronal and microglial OPN upregulation, followed by a later extended phase of expression in reactive astrocytes. OPN immunoreactivity after OGD matched the mRNA induction patterns. Activated microglia revealed OPN staining in focal deposits, whereas neurons and reactive astrocytes showed perinuclear staining with a punctate cytosolic pattern of OPN, typical of secreted proteins. These data demonstrated that the temporal and cellular patterns of OPN induction in reactive glial cells in this in vitro model closely correlated with that in the in vivo model, suggesting that OPN has a multifunctional role in the pathogenesis of ischemic injury.