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1

Calibration of very close range digital cameras

100%

Bujakiewicz A., Kowalczyk M., Podlasiak P., Zawieska D., Bujakiewicz A., Kowalczyk M., Podlasiak P., Zawieska D.

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vol. 55

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issue 2

2

Analysis of Calibration Coefficients of Plane-Parallel Markus Type Ionization Chambers Calibrated in Co-60 and Electron Beams

100%

Bulski W., Ulkowski P., Gwiazdowska B.

Polish Journal of Medical Physics And Engineering

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2007

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vol. 13

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issue 3

163-174

EN

The Polish Secondary Standard Dosimetry Laboratory is part of the IAEA/WHO network of such laboratories. The SSDLs are usually not equipped with accelerators generating high energy electron beams for calibration of dosimeters. The access to medical accelerators is seriously limited due to the heavy patient load. Therefore attempts are made to use Co-60 beams for calibration of plane parallel chambers and calculate the calibration coefficients for other radiation quality, the high energy electron beam.The Markus ionization chambers, most frequently used in Poland, were analyzed in this study. The material was composed of 36 plane parallel chambers, from 20 radiotherapy centers in Poland, calibrated at the Polish SSDL during the period of 2003-2006. Before actual calibration, a number of chamber parameters were tested: long term stability, dark current, chamber sensitivity, non-linearity of dosimeter readings. Each chamber was calibrated in two different radiation beams: a) Varian 2300 accelerator 22 MeV electron beams, beam output 1.2 cGy/MU at 300 MU/min; b) Co-60 Theratron 780/403 unit with a Cobalt-60 source of 155700 GBq (4208 Ci) activity as of 6.01.2006. A reference dosimeter Keithley Instruments Inc. 6517-A with cylindrical ionization chambers Nuclear Enterprises Technology Limited type 2571 was used as the reference standard. The methods of IAEA Code of Practice for Dosimetry TRS 398 were adopted. The long term stability was analyzed on basis of calibration coefficients of 23 Markus chambers calibrated several times during the period 1994-2002.Very small differences in calibration coefficients were detected between the two calibration methods used. They ranged between -0.3 to +0.5%, the mean value being 0.1%. A very good long term stability of calibration coefficients of Markus chambers, related to the mean value over the 7 year period, ranging between -0.5 to +0.3%, was recorded.Very small differences in the results for the two calibration methods, confirmed by small standard deviations observed, indicate that these two calibration methods in the case of Markus-type plane parallel chambers may be used alternatively.

88%

Gryś S.

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issue 1

9

Image-to-patient registration by natural anatomical surfaces of the head

88%

Marmulla R., Mühling J., Eggers G.

Open Medicine

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2007

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vol. 2

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issue 1

89-102

EN

The use of registration markers in computer-assisted surgery is combined with high logistic costs and efforts. During the preparation of image guided surgery, automated markerless patient-to-image registration based on anatomical surfaces allows a significant reduction of preoperative effort and of the radiation dose the patient is exposed to. Placement and measurement of radio-opaque fiducial markers becomes unnecessary. The usability of face, auricle, maxilla and mandible for surface-based registration to CT image data was investigated. The present study was performed to evaluate the clinical accuracy in finding defined target points within the surgical site after markerless patient registration in image-guided oral and maxillofacial surgery. Preoperatively, the spatial position of 20 patients was registered to CT image data using a 3D laser surface scanner. Indications for surgery were tumours, foreign bodies and skeletal malformations. The accuracy of this surface-based registration was verified using additionally placed fiducial markers. The study showed, that markerless surface-based registration was sufficiently accurate for clinical use when the surface used for matching was the upper jaw, the face, or - with reservations - the auricle. Surface-based registration using the mandible did not yield satisfying results. To conclude, image-to-patient registration based on laser surface scanning is a valuable method for surgery of the head. Multiple sites of the head were identified as appropriate for the method. Hence, dependent on the individual case and the intended surgery, the registration area can be selected with the necessary flexibility.

10

An analysis of calibration coefficients measured in water and in air for Farmer-type cylindrical ionization chambers

88%

Bulski W., Ulkowski P., Gwiazdowska B., Rostkowska J.

Polish Journal of Medical Physics And Engineering

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2008

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vol. 14

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issue 2

113-121

EN

A comparison of calibration coefficients of Farmer-type cylindrical ionization chambers calibrated in a Co-60 beam according to the IAEA Reports 277 and 398 formalisms.91 calibration coefficients measured in air and in water.The 398ND, W/277ND, W ratios were calculated, taking into account the wall material of the chambers. The correlation between 398ND, W and NK, ND, air277ND, W was made and the equations of the regression straight lines were determined.Calibration coefficients, determined according to the IAEA Report 398, are higher by about 1% than those determined according to the IAEA Report 277, and they depend slightly on the wall material of the chamber.The introduction of the IAEA dosimetry Report 398 resulted in an increase in the doses delivered to patients by about 1% as compared with the period of application of Report 277. The regression equations may assure increased accuracy in retrospective comparative calculation of doses according to both reports as compared with the correction based on mean percent values.

11

A Statistical Approach To Prediction Of The CMM Drift Behaviour Using A Calibrated Mechanical Artefact

88%

Cuesta E., Alvarez B., Sanchez-Lasheras F., Gonzalez-Madruga D.

Metrology and Measurement Systems

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2015

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vol. 22

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issue 3

12

Hardware Techniques for Improving the Calibration Performance of Direct Resistive Sensor-to-Microcontroller Interface

88%

Kokolanski Z., Gavrovski C., Dimcev V., Makraduli M.

Metrology and Measurement Systems

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2013

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issue 4

13

The Influence of the Load on the Hardness

75%

Petrík J., Palfy P.

Metrology and Measurement Systems

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2011

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issue 2

14

Investigation of the lithuanian national standard of electric resistance

75%

Bartašiunas A., Miškinis R., Smirnov D., Urba E., Bartašiunas A., Miškinis R., Smirnov D., Urba E.

Metrology and Measurement Systems

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2020

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vol. 27

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issue 4

15

Performance evaluation of HEC-HMS model for continuous runoff simulation of Gilgel Gibe watershed, Southwest Ethiopia

75%

Fanta S. S., Feyissa T. A., Fanta S. S., Feyissa T. A.

Journal of Water and Land Development

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2021

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issue 50

16

Hydrological modelling using the SWAT model based on two types of data from the watershed of Beni Haroun dam, Algeria

75%

Kateb Z., Bouchelkia H., Benmansour A., Belarbi F.

Journal of Water and Land Development

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2019

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issue 43

17

Dual manipulator system calibration based on virtual constraints

75%

Zhu Q., Xie X., Li C.

Bulletin of the Polish Academy of Sciences: Technical Sciences

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2019

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issue 6

18

Performance evaluation of solar radiation equations for estimating reference evapotranspiration (ETo) in a humid tropical environment

75%

Ndulue E., Onyekwelu I., Ogbu K. N., Ogwo V.

Journal of Water and Land Development

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2019

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issue 42

19

Metrological equipment for verification and calibration of non-automatic weighing instruments – axle and crane weighting instrument

75%

Gajdosik T., Kucera L., Gajdac I., Fric A., Markovic J., Gajdosik T., Kucera L., Gajdac I., Fric A., Markovic J.

Metrology and Measurement Systems

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2021

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vol. 28

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issue 2

20

Directional Solidification of AlSi Alloys with Fe Intermetallic Phases

75%

Mikołajczak P., Ratke L.

Archives of Foundry Engineering

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2014

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issue 1

Refine search results

Calibration of very close range digital cameras

Analysis of Calibration Coefficients of Plane-Parallel Markus Type Ionization Chambers Calibrated in Co-60 and Electron Beams

Automated calibration of the simulation mode lof irrigation projects by harmony search optimization

3D Acoustic Field Intensity Probe Design and Measurements

Inertial Navigation Static Calibration

Characterization of a static expansion standard for calibrating medium and high vacuum pressure gauges

An investigation on using the falling mass technique for dynamic force calibrations

An Experimental Test Bench for the Tire Pressure Monitoring System – Discussion of Measurement and Communication Issues

Image-to-patient registration by natural anatomical surfaces of the head

An analysis of calibration coefficients measured in water and in air for Farmer-type cylindrical ionization chambers

A Statistical Approach To Prediction Of The CMM Drift Behaviour Using A Calibrated Mechanical Artefact

Hardware Techniques for Improving the Calibration Performance of Direct Resistive Sensor-to-Microcontroller Interface

The Influence of the Load on the Hardness

Investigation of the lithuanian national standard of electric resistance

Performance evaluation of HEC-HMS model for continuous runoff simulation of Gilgel Gibe watershed, Southwest Ethiopia

Hydrological modelling using the SWAT model based on two types of data from the watershed of Beni Haroun dam, Algeria

Dual manipulator system calibration based on virtual constraints

Performance evaluation of solar radiation equations for estimating reference evapotranspiration (ETo) in a humid tropical environment

Metrological equipment for verification and calibration of non-automatic weighing instruments – axle and crane weighting instrument

Directional Solidification of AlSi Alloys with Fe Intermetallic Phases