Sample records for bipm key comparison
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Goebel, R.; Power, O.; Fletcher, N.; Stock, M.
2012-01-01
This report describes the results obtained from a NML(Ireland)-BIPM bilateral comparison of 1 Ω resistance standards in 2010. The comparison was carried out in the framework of the BIPM ongoing key comparison BIPM.EM-K13.a. Two BIPM 1 Ω travelling standards of CSIRO type were calibrated first at the BIPM, then at the NMLI and again at the BIPM after their return. The stability of the transfer standard was such that the uncertainty associated with the transfer was significantly smaller than the uncertainty arising from the calibrations. The mean difference between the NMLI and the BIPM calibrations was found to be just within the expanded uncertainty (k = 2) of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Goebel, R.; Power, O.; Fletcher, N.; Stock, M.
2012-01-01
This report describes the results obtained from a NML(Ireland)-BIPM bilateral comparison of 10 kΩ resistance standards in 2010. The comparison was carried out in the framework of the BIPM ongoing key comparison BIPM.EM-K13.b. Two BIPM 10 kΩ travelling standards of SR104 type were calibrated first at the BIPM, then at the NMLI and again at the BIPM after their return. The stability of the transfer standards was such that the uncertainty associated with the transfer was significantly smaller than the uncertainty arising from the calibrations. The NMLI and the BIPM calibrations were found to be in agreement, with a mean difference smaller than the standard uncertainty of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Gournay, Pierre; Power, Oliver
2017-01-01
This report presents the results of a bilateral comparison of capacitance at 100 pF between the NSAI-NML (Ireland) and the BIPM carried out in 2016. This comparison forms part of the ongoing BIPM key comparison BIPM.EM-K14.b in which the BIPM is the pilot laboratory. Two 100 pF travelling standards belonging to the BIPM were used in this comparison carried out with an 'A-B-A' pattern of measurements. The standards were measured first at the BIPM for a period of about one month, then for a similar period at the NSAI-NML, and finally again at the BIPM. The measurand was the two terminal-pair capacitance at a frequency of 1000 Hz, for a measuring rms voltage of 15 V. The results from the NSAI-NML and the BIPM were found to be in relatively good agreement, with a difference smaller than the relative expanded uncertainty (95 % confidence, k = 2) of 0.85 × 10-6. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Power, O.; Moran, A.; Fletcher, N.; Goebel, R.; Stock, M.
2015-01-01
This report gives the result of a bilateral comparison of capacitance between the NSAI-NML (Ireland) and the BIPM carried out in 2011. Two 100 pF travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a similar period at the NSAI-NML, and finally again at the BIPM. The measurand was the two terminal-pair capacitance at a frequency of 1000 Hz, for a measuring voltage of 15 V. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparison BIPM.EM-K14.b. The results from the NSAI-NML and the BIPM were found to be in good agreement, with a difference smaller than the relative expanded uncertainty (95 % confidence, k = 2) of 0.66 × 10-6. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Power, O.; Moran, A.; Fletcher, N.; Goebel, R.; Stock, M.
2015-01-01
This report gives the result of a bilateral comparison of capacitance between the NSAI-NML (Ireland) and the BIPM carried out in 2011. Two 10 pF travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A—B—A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a similar period at the NSAI-NML, and finally again at the BIPM. The measurand was the two terminal-pair capacitance at a frequency of 1000 Hz for a measuring voltage of 15 V. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparison BIPM.EM-K14.a. The results from the NSAI-NML and the BIPM were found to be in good agreement, with a difference smaller than the relative expanded uncertainty (95 % confidence, k = 2) of 2.5 × 10-6. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Rolland, B.; Fletcher, N.; Power, O.
2017-01-01
This report gives the result of a bilateral comparison of resistance between the NSAI NML (Ireland) and the BIPM carried out in 2014-2015. Two 1 Ω and two 10 kΩ travelling standards belonging to the BIPM were used. The comparison was carried out with an 'A-B-A' pattern of measurements; the standards were measured first at the BIPM for a period of about one month, then for a similar period at the NSAI-NML, and finally again at the BIPM. The measurand was the 4 terminal dc resistance at low power. The BIPM was the pilot laboratory, and the comparison forms part of the ongoing BIPM key comparisons BIPM.EM-K13.a (for 1 Ω) and BIPM.EM-K13b (for 10 kΩ). The results from the NSAI NML and the BIPM were found to be in good agreement, with a difference smaller than the relative expanded uncertainties (95% confidence, k = 2) of 0.16 × 10-6 for 1 Ω and 0.42 × 10-6 for 10 kΩ. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Solve, S.; Chayramy, R.; Power, O.; Stock, M.
2014-01-01
As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out in February and March 2014. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_4 (Z4) and BIPM_5 (Z5), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the value assigned to DC voltage standard by NSAI-NML, at the level of 10 V, at NSAI-NML, UNML, and that assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 10 March 2014. UNML - UBIPM = -0.64 µV uc = 1.35 µV, at 10 V where uc is thecombined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML,based on KJ-90, and the uncertainty related to the comparison. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated standard uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to
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Solve, S.; Chayramy, R.; Power, O.; Stock, M.
2016-01-01
As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland - National Metrology Laboratory (NSAI - NML), Dublin, Ireland, was carried out in January and February 2016. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM7 (Z7) and BIPM9 (Z9), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NSAI - NML, at the level of 10 V, at NSAI - NML, UNML, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 31 of January 2016. UNML - UBIPM = + 0.22 μV uc = 1.35 μV , at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Power, O.; Solve, S.; Chayramy, R.; Stock, M.
2011-01-01
As a part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from March to April 2011. Two BIPM Zener diode-based travelling standards (Fluke 732B) were transported by freight to NSAI-NML. At NSAI-NML, the 10 V output EMF of each travelling standard was measured by direct comparison with a group of characterized Zener diode-based electronic voltage standards. At the BIPM, the travelling standards were calibrated before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages on internal temperature and ambient pressure. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated expanded uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Power, O.; Solve, S.; Chayramy, R.; Stock, M.
2010-01-01
As a part of the ongoing BIPM key comparisons BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and of the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from March to April 2010. Two BIPM Zener diode-based travelling standards were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage is maintained at the 10 V level by means of a group of characterized Zener diode-based electronic voltage standards. The output EMF of each travelling standard, at the 10 V output terminals, was measured by direct comparison with the group standard. Measurements of the output EMF of the travelling standards at the 1.018 V output terminals were made using a potentiometer, standardized against the local 10 V reference standard. At the BIPM, the travelling standards were calibrated at both voltages before and after the measurements at NSAI-NML, using the BIPM Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages on internal temperature and ambient pressure. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated expanded uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Solve, S.; Chayramy, R.; Stock, M.; Power, O.
2015-01-01
As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland - National Metrology Laboratory (NSAI - NML), Dublin, Ireland, was carried out in February and March 2015. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM6 (Z6) and BIPMC (ZC), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final resultof the comparison is presented as the difference between the values assigned to DC voltage standards by NSAI - NML, at the level of 10 V,at NSAI - NML, UNML, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 24 February 2015. UNML - UBIPM = - 0.82 mV; uc = 1.35 mV , at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Power, O.; Chayramy, R.; Solve, S.; Stock, M.
2014-01-01
As part of the ongoing BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from January to February 2013. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_8 (Z8) and BIPM_9 (Z9), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (electromotive force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the value assigned to DC voltage standard by NSAI-NML, at the level of 10 V, at NSAI-NML, UNML, and that assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 5 February 2013. UNML - UBIPM = -0.63 µV uc = 1.31 µV, at 10 V where uc is thecombined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML,based on KJ-90, and the uncertainty related to the comparison. The comparison results show that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated standard uncertainties, on the mean date of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according
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Power, O.; Solve, S.; Chayramy, R.; Stock, M.
2012-01-01
As part of the on-going BIPM key comparison BIPM.EM-K11.b, a comparison of the 10 V voltage reference standards of the BIPM and the National Standards Authority of Ireland-National Metrology Laboratory (NSAI-NML), Dublin, Ireland, was carried out from February to March 2012. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPM_C (ZC) and BIPM_D (ZD), were transported by freight to NSAI-NML. At NSAI-NML, the reference standard for DC voltage at the 10 V level consists of a group of characterized Zener diode-based electronic voltage standards. The output EMF (electromotive force) of each travelling standard was measured by direct comparison with the group standard. At the BIPM the travelling standards were calibrated, before and after the measurements at NSAI-NML, with the Josephson voltage standard. Results of all measurements were corrected for the dependence of the output voltages on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the value assigned to DC voltage standard by NSAI-NML, at the level of 10 V, at NSAI-NML, UNML, and that assigned by the BIPM, at the BIPM, UBIPM, at the reference date of 23 February 2012. UNML - UBIPM = +0.83 µV, uc = 1.35 µV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. The final result is impacted by the anomalous offset between the NSAI-NML results for the two transfer standards. The reason for this offset hasn't been determined. However, the difference remains within the total combined standard uncertainty. Therefore, the comparison result shows that the voltage standards maintained by NSAI-NML and the BIPM were equivalent, within their stated expanded uncertainties, on the mean date of the comparison. Main text. To reach the main text of
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Kessler, C.; Burns, D. T.; Alvarez Romero, J. T.; De la Cruz Hernández, D.; Cabrera Vertti, M. R.; Tovar-Muñoz, V. M.
2015-01-01
A direct comparison of the standards for air kerma of the Instituto Nacional de Investigaciones Nucleares (ININ), Mexico, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam of the BIPM in February 2015. The comparison result, evaluated as a ratio of the ININ and the BIPM standards for air kerma, is 1.0048 with a combined standard uncertainty of 2.0 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Kessler, C.; Burns, D.; Machula, G.
2018-01-01
A comparison of the standards for air kerma of the Hungarian Trade Licensing Office (MKEH), Hungary and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in March 2016. The comparison result, evaluated as a ratio of the MKEH and the BIPM standards for air kerma, is 1.0047 with a combined standard uncertainty of 1.9 × 10-3. The results for an indirect comparison made at the same time are consistent with the direct results at the level of 2.6 parts in 103. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Solve, S.; Chayramy, R.; Ben Salah, B.; Mallat, A.; Abene, L.; Stock, M.
2016-01-01
As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1 V and 10 V voltage reference standards of the BIPM and the Laboratoire de Métrologie Electrique, DEFNAT (Tunisia), was carried out from February to March 2016. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPMC (ZC) and BIPM6 (Z6), were transported by freight to DEFNAT and back to BIPM. In order to keep the Zeners powered during their transportation phase, a BIPM in-house voltage stabiliser was connected in parallel to the internal battery. The voltage stabiliser consists of a set of two batteries, electrically protected from surcharge-discharge, easy to recharge and is designed to power two transfer standards for 10 consecutive days. At DEFNAT, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at DEFNAT, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and ambient atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by DEFNAT, at the level of 1.018 V and 10 V, at DEFNAT, UDEFNAT, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference date of the 26th of February 2016. UDEFNAT - UBIPM = + 0.07 μV uc = 0.04 μV, at 1.018 V UDEFNAT - UBIPM = + 0.38 μV uc = 0.10 μV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NSAI-NML, based on KJ-90, and the uncertainty related to the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which
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Solve, S.; Chayramy, R.; Matlejoane, A. M.; Magagula, L.; Stock, M.
2018-01-01
As part of the ongoing BIPM key comparison BIPM.EM-K11.a and b, a comparison of the 1.018 V and 10 V voltage reference standards of the BIPM and the National Metrology Institute of South Africa, NMISA (South Africa), was carried out from April to June 2017. Two BIPM Zener diode-based travelling standards (Fluke 732B), BIPMA (ZA) and BIPMB (ZB), were transported by freight to NMISA and back to BIPM. In order to keep the Zeners powered during their transportation phase, a voltage stabilizer developed by BIPM was connected in parallel to the internal battery. It consists of a set of two batteries, electrically protected from surcharge-discharge, easy to recharge and is designed to power two transfer standards for ten consecutive days. At NMISA, the reference standard for DC voltage is a Josephson Voltage Standard. The output EMF (Electromotive Force) of each travelling standard was measured by direct comparison with the primary standard. At the BIPM, the travelling standards were calibrated, before and after the measurements at NMISA, with the Josephson Voltage Standard. Results of all measurements were corrected for the dependence of the output voltages of the Zener standards on internal temperature and atmospheric pressure. The final result of the comparison is presented as the difference between the values assigned to DC voltage standards by NMISA, at the level of 1.018 V and 10 V, at NMISA, UNMISA, and those assigned by the BIPM, at the BIPM, UBIPM, at the reference dates of the 19th and 18th of May 2017, respectively. UNMISA - UBIPM = + 0.07 μV uc = 0.02 μV, at 1.018 V UNMISA - UBIPM = + 0.001 μV uc = 0.34 μV, at 10 V where uc is the combined standard uncertainty associated with the measured difference, including the uncertainty of the representation of the volt at the BIPM and at NMISA, based on KJ-90, and the uncertainty related to the comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which
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Allisy-Roberts, P. J.; Kessler, C.; Burns, D. T.; Berlyand, V.; Berlyand, A.
2010-01-01
A new comparison of the standards for absorbed dose to water of the All-Russian Scientific Research Institute for Physical-Technical and Radiotechnical Measurements (VNIIFTRI), Russia and of the Bureau International des Poids et Mesures (BIPM) has been made in 60Co gamma radiation in 2009. The results show that the VNIIFTRI and the BIPM standards for absorbed dose to water are in agreement, yielding a mean ratio of 0.9976 for the calibration coefficients of the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0043) for this result. This result is consistent with the earlier 2001 comparison result of 0.9967 (43). The updated degrees of equivalence for the VNIIFTRI are compared with those of the other national metrology institutes as presented in the BIPM key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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International Nuclear Information System (INIS)
Michotte, C.; Ratel, G.; Courte, S.; Joseph, L.
2015-01-01
A new participation in the BIPM.RI(II)-K1.Zn-65 comparison has been added to the previous results. A link has been made to the CCRI(II)-K2.Zn-65 comparison held in 2003 through the measurement of all ampoules of the K2 comparison in the International Reference System (SIR) at the BIPM before despatch to the participants. This has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. Six NMIs used the K2 comparison to update their degree of equivalence. The degrees of equivalence between each equivalent activity measured in the International Reference System (SIR) and the KCRV have been calculated and the results are given in the form of a table for the remaining two NMIs in the BIPM.RI(II)-K1.Zn-65 comparison and the 17 other participants in the CCRI(II)-K2.Zn-65 comparison. A graphical presentation is also given. (authors)
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BIPM direct on-site Josephson voltage standard comparisons: 20 years of results
International Nuclear Information System (INIS)
Solve, Stephane; Stock, Michael
2012-01-01
The discovery of the Josephson effect has for the first time given national metrology institutes (NMIs) the possibility of maintaining voltage references which are stable in time. In addition, the introduction in 1990 of a conventional value for the Josephson constant, K J-90 , has greatly improved world-wide consistency among representations of the volt. For 20 years, the Bureau International des Poids et Mesures (BIPM) has conducted an ongoing, direct, on-site key comparison of Josephson voltage standards among NMIs under the denominations BIPM.EM-K10.a (1 V) and BIPM.EM-K10.b (10 V) in the framework of the mutual recognition arrangement (CIPM MRA). The results of 41 comparisons illustrate the consistency among primary voltage standards and have demonstrated that a relative total uncertainty of a few parts in 10 10 is achievable if a few precautions are taken with regard to the measurement set-up. Of particular importance are the grounding, efficient filters and high insulation resistance of the measurement leads, and clean microwave distribution along the propagation line to the Josephson array. This paper reviews the comparison scheme and technical issues that need to be taken into account to achieve a relative uncertainty at the level of a few parts in 10 10 or even a few parts in 10 11 in the best cases. (paper)
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International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Kessler, C.; Burns, D.T.; Berlyand, V.; Berlyand, A.
2010-01-01
A new comparison of the standards for absorbed dose to water of the All-Russian Scientific Research Institute for Physical-Technical and Radio-technical Measurements (VNIIFTRI), Russia and of the Bureau International des Poids et Mesures (BIPM) has been made in 60 Co gamma radiation in 2009. The results show that the VNIIFTRI and the BIPM standards for absorbed dose to water are in agreement, yielding a mean ratio of 0.9976 for the calibration coefficients of the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0043) for this result. This result is consistent with the earlier 2001 comparison result of 0.9967 (43). The updated degrees of equivalence for the VNIIFTRI are compared with those of the other national metrology institutes as presented in the BIPM key comparison database. (authors)
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Energy Technology Data Exchange (ETDEWEB)
Allisy-Roberts, P.J.; Kessler, C.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Berlyand, V.; Berlyand, A. [All-Russian Scientific Research Institute for Physical-Technical and Radiotechnical Measurements, Moscow (Russian Federation)
2010-02-15
A new comparison of the standards for absorbed dose to water of the All-Russian Scientific Research Institute for Physical-Technical and Radio-technical Measurements (VNIIFTRI), Russia and of the Bureau International des Poids et Mesures (BIPM) has been made in {sup 60}Co gamma radiation in 2009. The results show that the VNIIFTRI and the BIPM standards for absorbed dose to water are in agreement, yielding a mean ratio of 0.9976 for the calibration coefficients of the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0043) for this result. This result is consistent with the earlier 2001 comparison result of 0.9967 (43). The updated degrees of equivalence for the VNIIFTRI are compared with those of the other national metrology institutes as presented in the BIPM key comparison database. (authors)
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International Nuclear Information System (INIS)
Michotte, C.; Ratel, G.; Courte, S.; Kharitonov, I.A.; Zanevsky, A.V.; Terechtchenko, E.E.; Moune, M.; Aubineau-Laniece, I.; Bobin, C.; Arenillas, P.; Balpardo, C.
2014-01-01
Three new participants in the BIPM.RI(II)-K1.Eu-152 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the COOMET.RI(II)-K2.Eu-152 comparison held in 2010 through the VNIIM who participated in both comparisons. Three National Metrology Institutes (NMIs) used the K1 or K2 comparisons to update their degree of equivalence. The degrees of equivalence between each equivalent activity measured in the International Reference System (SIR) and the KCRV have been calculated and the results are given in the form of a table for four NMIs in the BIPM.RI(II)-K1.Eu-152 comparison, three participants in the COOMET.RI(II)-K2.Eu-152 comparison and the 18 other participants in the previous CCRI(II)-K2.Eu-152 comparison. A graphical presentation is also given. (authors)
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International Nuclear Information System (INIS)
Kessler, C.; Allisy-Roberts, P.J.; Selbach, H.J.
2015-01-01
An indirect comparison of the standards for reference air kerma rate (RAKR) for 192 Ir high dose rate (HDR) brachytherapy sources of the Physikalisch-Technische Bundesanstalt (PTB), Germany, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the PTB in September 2011. The comparison result, based on the calibration coefficients for a transfer standard and expressed as a ratio of the PTB and the BIPM standards for reference air kerma rate, is 1.0003 with a combined standard uncertainty of 0.0099. (authors)
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Allal, Djamel
2009-01-01
A bilateral comparison subsequent to key comparison CCEM.RF-K9 was decided between VNIIFTRI and PTB. It was registered into the BIPM KCDB under the identifier CCEM.RF-K9.1. The results of this comparison were gathered by the pilot laboratory of comparison CCEM.RF-K9, the LNE, and a very good agreement was found between the two participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Becerra, Luis Omar
2009-01-01
This SIM comparison on the calibration of high accuracy hydrometers was carried out within fourteen laboratories in the density range from 600 kg/m3 to 1300 kg/m3 in order to evaluate the degree of equivalence among participant laboratories. This key comparison anticipates the planned key comparison CCM.D-K4, and is intended to be linked with CCM.D-K4 when results are available. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Energy Technology Data Exchange (ETDEWEB)
Allisy-Roberts, P.J.; Kessler, C.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Delaunay, F.; Donois, M. [CEA Saclay, LNE-LNHB, Lab. National Henri Becquerel 91 - Gif-sur-Yvette (France)
2009-10-15
A direct comparison of the standards for air kerma of the Laboratoire National de Metrologie et d'Essais-Laboratoire National Henri Becquerel (LNE-LNHB), France and of the Bureau International des Poids et Mesures (BIPM) was carried out in the {sup 137}Cs radiation beam of the BIPM in November 2008. The result, expressed as a ratio of the LNE-LNHB and the BIPM standards for air kerma, is 0.9984 with a combined standard uncertainty of 2.6 * 10{sup -3}. The result of the earlier direct comparison in {sup 137}Cs {gamma} rays, made in 1995, was 1.0019(30); taking into account the changes made to the BIPM standard and using the present correction factors for the LNE-LNHB standard, the 1995 result becomes 0.9989(26), which is in agreement with the present comparison result. (authors)
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DEFF Research Database (Denmark)
Alvarez, J.T.; De Pooter, J.A.; Andersen, Claus E.
2014-01-01
An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate brachytherapy sources of the Dutch Metrology Institute (VSL), The Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the VSL in November 2009. The comparison resu...
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Energy Technology Data Exchange (ETDEWEB)
Michotte, C.; Courte, S.; Ratel, G. [Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, F-92312 Sevres cedex (France); Moune, M.; Bobin, C. [Laboratoire national de metrologie et d' essais-Laboratoire National Henri Becquerel (LNE-LNHB), Gif-sur-Yvette Cedex (France)
2011-06-15
In 2006, to update their previous result of 1992, the LNE-LNHB submitted a new sample of {sup 75}Se with an activity of about 2.2 MBq to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). This comparison has the identifier BIPM.RI(II)-K1.Se-75. The degree of equivalence between the equivalent activity measured in the SIR for the new LNE-LNHB sample and the updated key comparison reference value (KCRV) has been calculated, as have the degrees of equivalence with each of the other participants. The results are given in the form of a matrix and a graphical presentation is also given. (authors)
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Comparison of the standards of air kerma of the OMH and the BIPM for 60Co gamma radiation
International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Kessler, C.; Burns, D.T.; Roger, P.; Machula, G.; Csete, I.; Rabus, H.
2006-09-01
A direct comparison between the standards for air kerma of the Orszagos Meresugyi Hivatal (OMH) and of the Bureau International des Poids et Mesures (BIPM) has been carried out in the 60 Co radiation beams of the BIPM. The result, expressed as a ratio of the OMH and the BIPM standards for air kerma, indicates a relative difference of 10.9 x 10 -3 with a combined standard uncertainty of 2.2 x 10 -3 . This new result agrees at the level of 0.4 x 10 -3 with the earlier direct comparisons performed in 1986 and 1994, as modified in 2001 by the application of wall and axial non-uniformity correction factors, calculated for the OMH standards using the Monte Carlo method. (authors)
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Picard, S.; Nonis, M.; Solve, S.; Allisy-Roberts, P. J.; Renaot, E.; Martin, C.
2011-01-01
A comparison of standard platinum resistance thermometers (SPRTs) has been carried out between the BIPM and the Laboratoire commun de métrologie LNE-CNAM using the melting point of gallium and the triple point of water. The temperature difference at Ga between the BIPM and the LNE-CNAM was determined as 108 µK with an associated combined standard uncertainty of 223 µK. This outcome indicates a present temperature difference of the BIPM of -65 µK with respect to an Average Reference Value from an earlier comparison, with an associated uncertainty of uc = 262 µK. It should be noted that the present BIPM scale is not independent, but traceable to cells used in KC7. The comparison results validate the re-establishment of thermometer calibrations at the BIPM for internal use. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Comparison of the air-kerma standards of the PTB and the BIPM in the low-energy X-ray range
International Nuclear Information System (INIS)
Burns, D.T.; Bueermann, L.; Kramer, H.M.; Lange, B.
2001-09-01
A direct comparison has been made between the air-kerma standards of the Physikalisch-Technische Bundesanstalt (PTB), Germany, and the Bureau International des Poids et Mesures (BIPM) in the x-ray range from 10 kV to 50 kV. Additional measurements were made at 80 kV and 100 kV to provide information on the electron-loss correction for the BIPM standard at these qualities. The comparison took place at the BIPM in March 1999 using the reference conditions recommended by the CCRI. There is general agreement at the level of one standard uncertainty, although there is a significant trend in the results between 30 kV and 50 kVa. This is in part due to the treatment of fluorescence radiation. The effect of fluorescence for the BIPM standard has been calculated using the Monte Carlo code EGSnrc and the fluorescence correction calculated in this way and the effect of including these new values in the present comparison are given. It should be noted, however, that these new correction factors for the BIPM standard have not yet been adopted. The result at 10 kV is significantly different from the others. This is not uncommon and raises a number of possibilities, for example the large corrections for air attenuation and guard wire attenuation, or unexplained aperture effects that have arisen in certain comparisons. In this respect, it is possible that the uncertainties for the 10 kV quality are underestimated. The measurements at 80 kV and 100 kV were made principally to test the correction factors for the BIPM standard, making use of the fact that the large electrode separation of the PTB PK100 chamber results in very little electron loss. (authors)
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Heinonen, Martti
2010-01-01
The first humidity CIPM key comparison, CCT-K6, will be completed in 2010. The corresponding European regional key comparison, EUROMET.T-K6, was carried out in 2004 to 2008. National metrology institutes from 24 countries participated in the comparison. The comparison covered the dew-point temperature range from -50 °C to +20 °C. It was organized as three parallel loops with two specially manufactured precision chilled mirror hygrometers as transfer standards in each loop. The comparison scheme was designed to ensure high quality results with evenly spread workload for the participants. MIKES was coordinating the project. This report presents the results of the comparison and provides detailed information on the measurements performed by all participating laboratories and the analysis of the results. Conclusions on the equivalence of the dew-point temperature standards are drawn on the basis of calculated bilateral degrees of equivalence and deviations from EURAMET comparison reference values (ERV). Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Energy Technology Data Exchange (ETDEWEB)
Michotte, C.; Ratel, G.; Courte, S. [Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, 92 - Sevres (France); Verdeau, E.; Amiot, M.N. [Laboratoire national de metrologie et d' essais-Laboratoire National Henri Becquerel (LNE-LNHB), 91 - Gif-sur-Yvette (France)
2010-10-15
In 2006, the Laboratoire national de metrologie et d'essais - Laboratoire national Henri Becquerel (LNE-LNHB) submitted a sample of known activity of {sup 111}In to the International Reference System (SIR). The value of the activity submitted was about 14 MBq. This provides a new result for France in the matrix of degrees of equivalence in the key comparison database that enables them to maintain their degrees of equivalence for this radionuclide. The key comparison reference value has been re-evaluated and the comparison, identifier BIPM.RI(II)-K1.In-111, now contains five valid results. (authors)
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Campos, Sara; Filipski, Piotr; Izquierdo, Daniel; Afonso, Edson; Landim, Régis P.; Di Lillo, Lucas; Lipe, Thomas
2009-01-01
Three comparisons of ac-dc voltage transfer difference held from January to December 2004 are reported. Six NMIs in the SIM region took part: NRC (Canada), NIST (United States of America), CENAM (Mexico), INTI (Argentina), UTE (Uruguay) and INMETRO (Brazil). The comparisons were proposed to assess the measurement capabilities in ac-dc voltage transfer difference of the NMIs in the SIM region. The test points were selected to link the results with the equivalent CCEM Key Comparisons, through three NMIs participating in both SIM and CCEM key comparisons. Additionally, a SIM.EM-Supplementary comparison was proposed, in support of the SIM NMIs' power/energy meter calibration capabilities. One technical protocol and one travelling standard were used, to economize on time and resources. The report shows the degree of equivalence in the SIM region and also the degree of equivalence with the corresponding CCEM reference value. The results of all participants support the values and uncertainties of the applicable CMC entries for ac-dc voltage transfer difference in the Key Comparison Database held at the BIPM. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Final report on CCM key comparison CCM.D-K2: Comparison of liquid density standards
Bettin, Horst; Jacques, Claude; Zelenka, Zoltán; Fujii, Ken-ichi; Kuramoto, Naoki; Chang, Kyung-Ho; Lee, Yong Jae; Becerra, Luis Omar; Domostroeva, Natalia
2013-01-01
The results are presented of the key comparison CCM.D-K2 that covered the density measurements of four liquids: the density of water at 20 °C, of pentadecane at 15 °C, 20 °C, 40 °C and 60°C, of tetrachloroethlyene at 5 °C and 20 °C and of a viscous oil at 20 °C. Seven national metrology institutes measured the densities at atmospheric pressure by hydrostatic weighing of solid density standards in the time interval from 27 April 2004 to 28 June 2004. Since the participants were asked not to include components for a possible drift or inhomogeneity of the liquid in their uncertainty budget, these uncertainty contributions are investigated for the final evaluation of the data. For this purpose, results of stability and homogeneity measurements of the pilot laboratory are used. The participants decided not to include a possible drift of the liquid's density since no significant drift could be detected, and the influence of the drift and its uncertainty are negligible. Similarly, the inhomogeneity of the water and pentadecane samples is not significant and has no influence on the evaluation. Thus, it was neglected. Only the inhomogeneities of tetrachloroethylene and of the viscous oil were significant. Consequently, they were included in the evaluation. With one or two exceptions, the results show good agreement among the participants. Only in the case of water are the results clearly discrepant. The key comparison reference values were calculated by the weighted mean (taking into account a small correlation between two participants) in the case of consistent results. Otherwise the Procedure B of Cox was used. The expanded uncertainties of all reference densities are below 1 × 10-5 in relative terms. This satisfies the needs of all customers who wish to calibrate or check liquid density measuring instruments such as oscillation-type density meters. The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database
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Energy Technology Data Exchange (ETDEWEB)
Michotte, C.; Ratel, G. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Cassette, P. [Bureau International de Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Laboratoire national de metrologie et d' essais -Laboratoire national Henri Becquerel, 91191 Gif-sur-Yvette cedex (France)
2012-02-15
In 2007, the Laboratoire national de metrologie et d'essais - Laboratoire national Henri Becquerel (LNE-LNHB), France submitted a sample of known activity of {sup 222}Rn to the International Reference System (SIR) for comparison. The value of the activity submitted was about 90 kBq. This key comparison result joins that of Switzerland and Germany in the key comparison database that now contains three results, identifier BIPM.RI(II)-K1.Rn-222. Consequently, the KCRV has been updated and the degrees of equivalence with the KCRV have been evaluated. (authors)
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Final report on RMO Vickers key comparison COOMET M.H-K1
Aslanyan, E.; Menelao, F.; Herrmann, K.; Aslanyan, A.; Pivovarov, V.; Galat, E.; Dovzhenko, Y.; Zhamanbalin, M.
2013-01-01
This report describes a COOMET key comparison on Vickers hardness scales involving five National Metrology Institutes: PTB (Germany), BelGIM (Belarus), NSC IM (Ukraine), KazInMetr (Kazakhstan) and VNIIFTRI (Russia). The pilot laboratory was VNIIFTRI, and PTB acted as the linking institute to key comparisons CCM.H-K1.b and CCM.H-K1.c conducted for the Vickers hardness scales HV1 and HV30, respectively. The comparison was also conducted for the HV5 Vickers hardness scale, since this scale is most frequently used in practice in Russia and CIS countries that work according to GOST standards. In the key comparison, two sets of hardness reference blocks for the Vickers hardness scales HV1, HV5 and HV30 consisting each of three hardness reference blocks with hardness levels of 450 HV and 750 HV were used. The measurement results and uncertainty assessments for HV1 and HV30 hardness scales, as announced by BelGIM, NSC IM, KazInMetr and VNIIFTRI, are in good agreement with the key comparison reference values of CCM.H-K1.b and CCM.H-K1.c. The comparison results for the HV5 hardness scale are viewed as additional information, since up to today no CCM key comparisons on this scale have yet been carried out. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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CCM key comparison CCM.D-K4 'Hydrometer'
Lorefice, S.; Becerra, L. O.; Lenard, E.; Lee, Y. J.; Lee, W. G.; Madec, T.; Meury, P. A.; Caceres, J.; Santos, C.; Vamossy, C.; Man, J.; Fen, K.; Toda, K.; Wright, J.; Bettin, H.; Toth, H.
2016-01-01
added to this comparison so that all participants were engaged after the breakage of the 9340171 artefact. A particularly good agreement was found among the results provided by most of the participants, even if some systematic differences and either underestimated or overestimated uncertainties of the submitted results can be identified with respect to the KCRVs. In general the deviations of the laboratory results to the KCRVs are within of 1/3rd to 1/4th of a scale division and the uncertainty at 95% is usually within half a division. During the analysis of the submitted results, a systematic difference between the first and last immersed mark was also noted, possibly due to a temperature gradient along the stem and/or wetting of the stem around the tested mark, and therefore a corrected claimed uncertainty from each laboratory is expected. However this comparison may help the laboratories to solve some residual or marginal problems as well as to better understand the uncertainty components. The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database (KCDB). The results can be used to link regional comparisons to this CCM key comparison Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Energy Technology Data Exchange (ETDEWEB)
Ratel, G.; Michotte, C.; Kryeziu, D. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Moune, M. [CEA Saclay, Laboratoire National de Metrologie et d' Essais, Laboratoire National Henri Becquerel (LNE-LNHB), 91 - Gif-sur-Yvette (France); Iwahara, A. [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes (LNMRI), Rio de Janeiro (Brazil)
2009-04-15
In 2006, two national metrology institutes (NMI) submitted samples of known activity of {sup 51}Cr solution to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). Consequently, 28 samples have been submitted since 1977, from nine NMI and three other laboratories. The activities ranged from about 3 MBq to 90 MBq. The key comparison reference value (KCRV) has been updated and the degrees of equivalence between each equivalent activity measured in the SIR and the KCRV have been calculated. The results are given in the form of a matrix for eight laboratories to which the APMP.RI(II)-K2.Cr-51 results have been added. A graphical presentation is also given. (authors)
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Final report on COOMET Vickers PTB/VNIIFTRI key comparison (COOMET.M.H-K1.b and COOMET.M.H-K1.c)
Aslanyan, E.; Herrmann, K.
2013-01-01
This report describes a COOMET key comparison on Vickers hardness scales of two National Metrology Institutes—PTB and VNIIFTRI. The pilot laboratory was PTB, which was the linking institute with the key comparison reference values of CCM.H-K1. In the key comparison two sets of hardness reference blocks for the Vickers hardness scales HV1 and HV30, each consisting of three hardness reference blocks with the hardness levels 240 HV, 540 HV and 840 HV, are used. The same hardness reference blocks were used previously in the key comparison CCM.H-K1. The measurement results and uncertainty assessments, announced by VNIIFTRI, are in good agreement with the key comparison reference values of CCM.H-K1. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Burns, D.T.; Boas, J.F.; Huntley, R.B.; Wise, K.N.
2000-10-01
A comparison of the standards for absorbed dose to water of the Australian Radiation Protection and Nuclear Safety Agency and of the Bureau International des Poids et Mesures (BIPM) has been carried out in 60 Co gamma radiation. The Australian standard is based on a graphite calorimeter and the subsequent conversion from absorbed dose to graphite to absorbed dose to water using the photon fluence scaling theorem. The BIPM standard is ionometric using a graphite-walled cavity ionization chamber. The comparison result is 1.0024 (standard uncertainty 0.0029). (authors)
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Hung, Chen-Chuan; Jian, Wu; Changpan, Tawat
2009-01-01
This report describes the key comparison APMP.M.P-K6.1 among the three national metrology institutes, Center for Measurement Standards-ITRI (CMS-ITRI, Taiwan), SPRING Singapore and National Institute of Metrology (NIMT), in the pressure range from 20 kPa to 105 kPa in gas media and gauge mode executed during the period April 2003 to April 2004. This comparison was conducted by CMS-ITRI and was based on the calibration procedure of APMP pneumatic pressure comparison APMP.M.P-K6. We intended to link to the CCM.P-K6 key comparison through the APMP.M.P-K6 key comparison by using the proposed linkage method in the APMP.M.P-K6 key comparison to determine a linking factor that can transform the quantities measured in the APMP.M.P-K6.1 key comparison. All three participating institutes used pneumatic piston gauges as their pressure standards. The Ruska 2465 gas-operated piston-cylinder assembly TL-1409 used as transfer standard offered by CMS-ITRI was calibrated three times by the pilot institute during the comparison period and showed that it was very stable after evaluation. The comparison was conducted on the basis of cross-float experiments to determine the effective area of transfer standards from the national standards of three institutes. The comparison results (as shown in Table 6) were equivalent to the CCM.P-K6 comparison and the relative bilateral degrees of equivalence between two laboratories were smaller than 39.7 × 10-6 from 20 kPa to 105 kPa. These results showed all participating institutes measuring the same quantity in the whole pressure range lay within their expanded uncertainty with confidence level 95%. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Gavrilkin, V.; Prokopenko, L.; Bakovec, N.; Zolotorevich, E.; Suvorov, V.; Ovchinnikov, Yu; Pilishvili, T.; Buleishvili, M.; Zhasanbaeva, B.; Aytzhatova, G.; Ticona, G.; Vyskocil, L.
2015-01-01
The COOMET.QM-K36 key comparison 'Electrolytic conductivity: 0.5 S/m' is a comparison in the field of electrolytic conductivity measurements conducted by COOMET and carried out in 2012. It used a solution of KCl in water and the results are connected to those of the CCQM key comparison CCQM-K36.a through common participation of VNIIFTRI (Russia), SMU (Slovakia) and Ukrmetrteststandart (Ukraine). The purpose of this key comparison was to establish the equivalence of measurements of electrolytic conductivity performed at the National Metrology Institutes of COOMET member states for the value of 0.5 S/m. The results can be used to support the CMCs claims over the range of 0.1 S/m to 1.3 S/m. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Janik, Dieter; Inoue, T.; Michaud, A.
2006-01-01
This report summarizes the results and the measuring methods of an international key comparison between twelve national metrology institutes (NMIs) and is concerning the calibration factor of RF power sensors in the coaxial 3.5 mm line for frequencies up to 26 GHz. Two RF power travelling standards fitted with male PC 3.5 mm connectors were measured at seven frequencies. The following NMIs participated: NMIJ (Japan), NRC (Canada), NIST (USA), METAS (Switzerland), CSIR-NML (South Africa), NMIA (Australia), NPL (UK), SiQ (Slovenia), IEN (Italy), VNIIFTRI (Russian Federation), SPRING (Singapore) and PTB (Germany), as the pilot laboratory. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Goenaga Infante, Heidi; Sargent, Mike
2010-01-01
, illustrating their ability to obtain accurate results for such analytes in a complex food matrix containing approximately 17 mg kg-1 Se. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Allal, Djamel; Achkar, Joseph
2006-01-01
An international comparison of thermal noise-power measurements has been carried out among five national metrology institutes between 12.4 GHz and 18 GHz. Four transfer standards were measured. The following national institutes participated: BNM-LCIE (France), NPL (United Kingdom), PTB (Germany), NIST (United States of America) and VNIIFTRI (Russia). The Bureau National de Métrologie-Laboratoire Central des Industries Electriques (France) acted as the pilot laboratory for the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Energy Technology Data Exchange (ETDEWEB)
Michotte, C.; Ratel, G. [Bureau International des Poids et Mesures (BIPM), Pavillon de Breteuil, F-92312 Sevres Cedex, (France); Moune, M.; Bobin, C. [Laboratoire national de metrologie et d' essais-Laboratoire national Henri Becquerel, 91191 Gif-sur-Yvette cedex, (France)
2011-07-01
In 2007, the Laboratoire national de metrologie et d'essais-Laboratoire national Henri Becquerel (LNE-LNHB), France submitted a sample of known activity of {sup 124}Sb to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM). The activity was about 5.3 MBq. The key comparison reference value (KCRV) has been recalculated to include this new value and the degrees of equivalence between each equivalent activity for the three participants measured in the SIR and the KCRV are presented in a table and graphically. (authors)
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Energy Technology Data Exchange (ETDEWEB)
Michotte, C.; Ratel, G.; Courte, S. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Hino, Y.; Yunoki, A. [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Bobin, C.; Moune, M. [CEA Saclay, Laboratoire National de Metrologie et d' Essais, Laboratoire National Henri Becquerel (LNE-LNHB), 91 - Gif-sur-Yvette (France)
2009-04-15
In 2006 and 2007, the National Metrology Institute of Japan (NMIJ) and the Laboratoire national de metrologie et d'essais-Laboratoire national Henri Becquerel (LNE-LNHB) submitted samples of known activity of {sup 57}Co to the International Reference System (SIR). The values of the activity submitted were about 1.7 MBq and 3.7 MBq respectively. The new key comparison results have replaced the previous results for Japan and France. These new results have enabled a re-evaluation of the key comparison reference value. The matrix of degrees of equivalence in the key comparison database that now contains twelve results, identifier BIPM.RI(II)-K1.Co-57, has been updated with the new results. (authors)
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International Nuclear Information System (INIS)
Milton, M.; Los Arcos, J.M.; Burns, D.T.; Kessler, C.; Picard, S.; Roger, P.; Courte, S.; Michotte, C.; Nonis, M.; Ratel, G.
2014-03-01
This BIPM Director's Report describes the activity of the BIPM. In order to carry out its mission of ensuring and promoting the global comparability of measurements, the BIPM operates laboratories in the fields of mass, time, electricity, ionizing radiation and chemistry. All of the laboratory work addresses one or more of the agreed objectives for the BIPM, which are: - To establish and maintain appropriate reference standards for use as the basis of a limited number of key international comparisons at the highest level. - To coordinate international comparisons of national measurement standards through the Consultative Committees of the CIPM; taking the role of coordinating laboratory for selected comparisons of the highest priority and undertaking the scientific work necessary to enable this to be done. - To provide selected calibrations for Member States. In this document some highlights of the work carried out during 2013 are presented. Extended reports of the work of each department are available at http://www.bipm.org/en/publications/directors_report/. This document comprises the Director's report with its supplement describing the work of the Ionizing Radiation Department (X- and γ-rays, Radionuclides, Thermometry)
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International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Burns, D.T.; Buermann, L.; Kramer, H.M.
2005-11-01
Direct comparisons of the standards for air kerma of the Physikalisch-Technische Bundesanstalt (PTB, Germany) and of the Bureau International des Poids et Mesures (BIPM) were carried out in the 60 Co and 137 Cs radiation beams of the BIPM in 2000. The results, expressed as ratios of the PTB and the BIPM standards for air kerma, indicate a relative difference in 60 Co of 9.9 x 10 -3 with a combined standard uncertainty of 1.8 x 10 -3 , and in 137 Cs of 6.4 x 10 -3 with a combined standard uncertainty of 2.8 x 10 -3 . The earlier comparisons in 60 Co γ rays made in 1971 (direct) and 1989 (indirect) resulted in an agreement of the two standards within 2 x 10 -3 . The differences obtained now are due to the application of new correction factors for wall effects and point source non-uniformity of the beam, k wall and k pn , for the PTB standards, which were calculated using Monte Carlo methods. (authors)
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Comparison of the air-kerma standards of the VNIIM and the BIPM in the medium-energy X-ray range
International Nuclear Information System (INIS)
Burns, D.T.; Villevalde, N.D.; Oborin, A.V.; Yurjatin, E.N.
2001-09-01
An indirect comparison has been made between the air-kerma standards of the VNIIM and the BIPM in the medium-energy x-ray range. The results show the standards to be in agreement within the stated uncertainty. (authors)
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Comparison of the air-kerma standards of the BEV and the BIPM in the low-energy X-ray range
International Nuclear Information System (INIS)
Burns, D.T.; Witzani, J.
2002-09-01
A direct comparison has been made between the air-kerma standards of the BEV and the BIPM in the low-energy x-ray range. The results at the different radiation qualities show the standards to be in reasonable agreement with respect to the combined relative standard uncertainty of the comparison of 2.4 x 10 -3 . (authors)
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International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Burns, D.T.; Berlyand, V.; Bregadze, Y.; Korostin, S.
2003-09-01
A comparison of the standards of absorbed dose to water of the All-Russian Scientific Research Institute for Physical-Technical and Radio-technical Measurements (VNIIFTRI), Russia and of the Bureau International des Poids et Mesures (BIPM) has been made in 60 Co gamma radiation. The results show that the VNIIFTRI and the BIPM standards for absorbed dose to water are in agreement, yielding a mean ratio of 0.9967 for the calibration factors of the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0043) for this result. (authors)
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Energy Technology Data Exchange (ETDEWEB)
Allisy-Roberts, P.J.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Berlyand, V.; Bregadze, Y.; Korostin, S. [All-Russian Scientific Research Institute for Physical-Technical and Radiotechnical Measurements, Moscow (Russian Federation)
2003-09-15
A comparison of the standards of absorbed dose to water of the All-Russian Scientific Research Institute for Physical-Technical and Radio-technical Measurements (VNIIFTRI), Russia and of the Bureau International des Poids et Mesures (BIPM) has been made in {sup 60}Co gamma radiation. The results show that the VNIIFTRI and the BIPM standards for absorbed dose to water are in agreement, yielding a mean ratio of 0.9967 for the calibration factors of the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0043) for this result. (authors)
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Spitzer, Petra; Giera, Janine; Fraga, Isabel C.; Tønnes Jakobsen, Pia; Jensen, Hans D.; Hyllested, Peter; Karpov, Oleg; Kutovoy, Viatcheslav; Nakamura, Susumu; Vospelova, Alena; Zvezdina, Valentina
2008-01-01
CCQM-K9.2 was performed supplementary to the key comparison CCQM-K9 on the pH determination of a phosphate buffer with nominal pH ~ 6.9 (at 25 °C). The sample composition was very similar in both comparisons. Only the source of the starting material used for sample preparation was different. The comparison was restricted to the use of the primary method for pH (Harned cell measurement) as defined in the IUPAC Recommendations [2]. The measurement temperatures were 15 °C, 25 °C, 37 °C. CCQM-K9.2, CCQM-K.9 and the first supplementary comparison CCQM-K9.1 [5] are activities of the Electrochemical Working Group (EAWG) of the CCQM. All three comparisons were coordinated by the PTB, Germany. The Danish Primary Laboratory (DPL) successfully took part in the CCQM-K9. Meanwhile the primary set-up for pH in Denmark moved from DPL affiliated to Radiometer Medical to DFM, Denmark. The subsequent comparison allows assessing the degree of equivalence for the measurement of pH at DFM after the move. Due to the interest of other laboratories in demonstrating their progress in pH measurements on the primary level the CCQM-K9.2 supplementary comparison was extended to other participants than DFM, namely NMIJ, VNIIFTRI, INMETRO and CMI. The reported quantity for CCQM-K9.2 was not the pH of the sample but the acidity function at zero chloride molality (see chapter 12). To calculate the pH value from the acidity function it is necessary to know the ionic strength of the sample buffer solution, which was undisclosed by the coordinator. With the exception of the Czech Metrology Institute, CMI, good agreement in the determined acidity function is found between the participants. The results reported by DFM and by PTB agree within their measurement uncertainty at all measurement temperatures. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report
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Bettin, Horst; Heinonen, Martti; Gosset, André; Zelenka, Zoltán; Lorefice, Salvatore; Hellerud, Kristen; Durlik, Hanna; Jordaan, Werner; Field, Ireen
2016-01-01
The results of the key comparison EUROMET 627 (EUROMET.M.D-K2) are presented. This project covered the density measurements of three liquids: dodecane, water and an oil of high viscosity measured at 15 °C, 20 °C and 40 °C. Seven European metrology laboratories and the South African laboratory CSIR-NML (now: NMISA) measured the densities at atmospheric pressure by hydrostatic weighing of solid density standards between 04 October 2001 and 18 December 2001. The stability and homogeneity of the liquids were investigated by the pilot laboratory PTB. The results generally show good agreement among the participants. Only for the simple Mohr-Westphal balances do the uncertainties seem to be underestimated by the laboratories. Furthermore, the measurement of high-viscosity oil was difficult for some laboratories. Nevertheless, the five laboratories PTB/DE, BNM/FR (now: LNE/FR), OMH/HU (now: MKEH/HU), IMGC/IT (now: INRIM/IT) and GUM/PL agree with each other for stated uncertainties of 0.05 kg/m3 or less. This satisfies the current needs of customers who wish to calibrate or check liquid density measuring instruments such as oscillation-type density meters. No reference values were calculated since the subsequent CCM key comparison CCM.D-K2 had a different scope and the EUROMET 627 comparison was soon superseded by the EURAMET 1019 (EURAMET.M.D-K2) comparison. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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APMP/TCRI key comparison report of measurement of air kerma for medium-energy x-rays (APMP.RI(I)-K3)
International Nuclear Information System (INIS)
Lee, J.H.; Hwang, W.S.; Kotler, L.H.; Webb, D.V.; Buermann, L.; Burns, D.T.; Takeyeddin, M.; Shaha, V.V.; Srimanoroth, S.; Meghzifene, A.; Hah, S.H.; Chun, K.J.; Kadni, T.B.; Takata, N.; Msimang, Z.
2008-01-01
The APMP/TCRI Dosimetry Working Group performed the APMP.RI(I)-K3 key comparison of measurement of air kerma for medium-energy x-rays (100 kV to 250 kV) between 2000 and 2003. In total, 11 institutes took part in the comparison, among which 8 were APMP member laboratories. Two commercial cavity ionization chambers were used as transfer instruments and circulated among the participants. All the participants established the 100 kV, 135 kV, 180 kV and 250 kV x-ray beam qualities equivalent to those of the BIPM. The results showed that the maximum difference between the participants and the BIPM in the medium-energy x-ray range, evaluated using the comparison data of the linking laboratories ARPANSA and PTB, is less than 1.4%. The degrees of equivalence between the participants are presented and this comparison confirms the calibration capabilities of the participating laboratories. (authors)
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APMP/TCRI key comparison report of measurement of air kerma for medium-energy x-rays (APMP.RI(I)-K3)
Energy Technology Data Exchange (ETDEWEB)
Lee, J.H.; Hwang, W.S. [Institute of Nuclear Energy Research, Longtan, Taiwan (China); Kotler, L.H.; Webb, D.V. [Australian Radiation Protection and Nuclear Safety Agency, Yallambie (Australia); Buermann, L. [Physikalisch Technische Bundesanstalt, Braunschweig (Germany); Burns, D.T. [Bureau International de Poids et Mesures, 92 - Sevres (France); Takeyeddin, M. [Atomic Energy Commission, Damascus (Syrian Arab Republic); Shaha, V.V. [Bhabha Atomic Research Centre, Mumbai (India); Srimanoroth, S. [Department of Medical Sciences, Nonthaburi (Thailand); Meghzifene, A. [International Atomic Energy Agency, Vienna (Austria); Hah, S.H.; Chun, K.J. [Korea Research Institute of Standards and Science, Yusong (Korea, Republic of); Kadni, T.B. [Malaysian Nuclear Agency, Kajang (Malaysia); Takata, N. [National Metrology Institute of Japan, Tsukuba (Japan); Msimang, Z. [National Metrology Institute of South Africa, Pretoria (South Africa)
2008-10-15
The APMP/TCRI Dosimetry Working Group performed the APMP.RI(I)-K3 key comparison of measurement of air kerma for medium-energy x-rays (100 kV to 250 kV) between 2000 and 2003. In total, 11 institutes took part in the comparison, among which 8 were APMP member laboratories. Two commercial cavity ionization chambers were used as transfer instruments and circulated among the participants. All the participants established the 100 kV, 135 kV, 180 kV and 250 kV x-ray beam qualities equivalent to those of the BIPM. The results showed that the maximum difference between the participants and the BIPM in the medium-energy x-ray range, evaluated using the comparison data of the linking laboratories ARPANSA and PTB, is less than 1.4%. The degrees of equivalence between the participants are presented and this comparison confirms the calibration capabilities of the participating laboratories. (authors)
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Meyer, C.; Solano, A.
2016-01-01
A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the Laboratorio Costarricense de Metrología (LACOMET, Costa Rica) between February 2015 and August 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and LACOMET and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and LACOMET. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Huang, P. H.; Meyer, C. W.; Martines-López, E.; Dávila Pacheco, J. A.; Méndez-Lango, E.
2014-01-01
A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the Centro Nacional de Metrologia (CENAM, Mexico) between July 2008 and December 2008. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and CENAM and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and CENAM. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Final report on the key comparison CCPR-K5: Spectral diffuse reflectance
Nadal, Maria; Eckerle, Kenneth L.; Early, Edward A.; Ohno, Yoshi
2013-01-01
shows overall good agreement among all participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Nuclear Information System (INIS)
Ratel, G.; Michotte, C.; Janssen, H.; Kossert, K.; Lucas, L.; Karam, L.
2005-01-01
In 2004, the Physikalisch-Technische Bundesanstalt (PTB, Germany) and the National Institute of Standards and Technology (NIST, USA) each submitted one sample of known activity of 109 Cd to the International Reference System (SIR). The PTB result replaces their previous measurement of 1994 and the NIST result updates their 1986 CCRI(II) comparison result. The values of the activity submitted were about 15 MBq and 42 MBq. The new key comparison results have replaced the earlier values in the matrix of degrees of equivalence that now contains six results, identifier BIPM.RI(II)-K1.Cd-109, to which the remaining eleven results from the CCRI(II)-K2.Cd-109 held in 1986 are still linked. (authors)
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Meyer, C. W.; Hill, K. D.
2015-01-01
A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the National Research Council (NRC, Canada) between December 2014 and April 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and NRC and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and NRC. This paper is the final report of the comparison including analysis of the uncertainty of measurement results. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT WG-KC, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Huang, Peter; Meyer, Christopher; Brionizio, Julio D.
2015-01-01
A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO, Brazil) between October 2009 and March 2010. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and INMETRO and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and INMETRO. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Comparison of the air-kerma standards of the PTB and the BIPM in the medium-energy X-ray range
International Nuclear Information System (INIS)
Burns, D.T.; Bueermann, L.; Kramer, H.M.; Lange, B.
2002-06-01
An indirect comparison has been made between the air erma standards of the PTB and the BIPM in the medium-energy x-ray range. The results show the standards to be in general agreement at the level of the stated standard uncertainty, although the result for the 100 kV radiation quality differs significantly from that for the other qualities. (authors)
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International Nuclear Information System (INIS)
Burns, D.T.; Toni, M.P.; Bovi, M.
2000-08-01
An indirect comparison has been made between the air erma standards of the ENEA-INMRI and the BIPM in the medium-energy x-ray range. The results show the standards to be in general agreement within the stated uncertainty, although there is evidence of a trend in the results at different radiation qualities. (authors)
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KEY COMPARISON: CCEM.RF-K18.CL (GT-RF/00-1): Noise in 50 Ω coaxial line at frequencies up to 1 GHz
Eiø, Christopher; Adamson, David; Randa, James; Allal, Djamel; Uzdin, Rinadij
2006-01-01
A measurement comparison of noise temperature has been carried out between four national metrology laboratories in coaxial line at 30 MHz, 60 MHz and 1 GHz. The identification of this intercomparison is CCEM.RF-K18.CL. Two noise sources have been measured. The following four national laboratories participated in this intercomparison: NPL (United Kingdom), NIST (United States of America), BNM-LNE (France) and VNIIFTRI (Russia). The National Physical Laboratory (UK) acted as the pilot laboratory for the comparison. It can be seen that there is generally good agreement between the laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Comparison of the air-kerma standards of the VNIIM and the BIPM in the low-energy X-ray range
International Nuclear Information System (INIS)
Burns, D.T.; Villevalde, N.D.; Oborin, A.V.; Yurjatin, E.N.
2002-05-01
An indirect comparison has been made between the air erma standards of the VNIIM and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at the level of one to two standard uncertainties. The trend in the results at different radiation qualities is explained in terms of the photon-scatter correction applied to the VNIIM standard. (authors)
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COOMET.RI(I)-K1 comparison of national measurement standards of air kerma for 60Co γ radiation
International Nuclear Information System (INIS)
Buermann, L.; Oborin, A.V.; Dobrovosky, J.; Milevsky, V.S.; Walwyn Salas, G.; Lapenas, A.
2009-01-01
Results are presented of the COOMET key comparison of the national measurement standards of air kerma for 60 Co γ radiation. Participants of the comparison were PTB (Germany, pilot institute), VNIIM (Russia), SMU (Slovakia), BelGIM (Belarus), CPHR (Cuba) and RMTC (Latvia). PTB, VNIIM and SMU had previously taken part in a key comparison with the Bureau International de Poids et Mesures (BIPM) and operated as link laboratories in order to evaluate the degree of equivalence of the participants' results with the key comparison reference value. These data form the basis of the results entered into the BIPM key comparison database for comparison COOMET.RI(I)-K1. (authors)
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Huang, Xuebo
2009-01-01
In order to assess the performance of the standards and techniques used for calibration and measurement of UVA irradiance responsivity of photodetectors in NMISA, South Africa, a new comparison was decided as a follow-up to comparison APMP.PR-S1. It is registered in the Key Comparison Data Base (KCDB) of BIPM as a bilateral supplementary comparison, with the identifier APMP.PR-S1.1. The comparison was carried out following the same technical protocol as that of supplementary comparison APMP PR-S1. The principle, organization and method of the comparison, as well as the preliminary measurements at the pilot laboratory NMC-A*STAR Singapore, were described in the Final Report of the APMP.PR-S1 comparison. The results of this bilateral comparison show that the NMISA's results lie within ±2% against the comparison reference values of APMP.PR-S1, which is a great improvement. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the APMP, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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CCQM key comparison CCQM-K75: Determination of toxic metals in algae
Shakhashiro, A.; Toervenyi, A.; Gaudino, S.; Rosamilia, S.; Belli, M.; Turk, G. C.
2011-01-01
in algae matrix. In addition, the NMIs demonstrated a wide range of 'core-capabilities' applicable to other measurement applications. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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International Nuclear Information System (INIS)
Gibson, F.H.; Smith, L.V.; Rutledge, A.R.; Merritt, J.S.
1979-02-01
This report describes the equipment used and the results obtained by the Radioisotope Standardization Group in its participation in the international comparison of activity measurements of a 134 Cs solution that was sponsored by Bureau International des Poids et Mesures (BIPM). The 4π(PC)-γ coincidence method was used with the γ-channel gate set narrowly around photopeaks of approximately 800 keV. The results are compared with those from three other γ-channel gates. An assessment of known and suspected sources of uncertainty is included. (author)
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Woolford, Alison; Holden, Marcia; Salit, Marc; Burns, Malcolm; Ellison, Stephen L. R.
2009-01-01
Key comparison CCQM-K61 was performed to demonstrate and document the capability of interested national metrology institutes in the determination of the quantity of specific DNA target in an aqueous solution. The study provides support for the following measurement claim: "Quantitation of a linearised plasmid DNA, based on a matched standard in a matrix of non-target DNA". The comparison was an activity of the Bioanalysis Working Group (BAWG) of the Comité Consultatif pour la Quantité de Matière and was coordinated by NIST (Gaithersburg, USA) and LGC (Teddington, UK). The following laboratories (in alphabetical order) participated in this key comparison. DMSC (Thailand); IRMM (European Union); KRISS (Republic of Korea); LGC (UK); NIM (China); NIST (USA); NMIA (Australia); NMIJ (Japan); VNIIM (Russian Federation) Good agreement was observed between the reported results of all nine of the participants. Uncertainty estimates did not account fully for the dispersion of results even after allowance for possible inhomogeneity in calibration materials. Preliminary studies suggest that the effects of fluorescence threshold setting might contribute to the excess dispersion, and further study of this topic is suggested Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Hioki, Akiharu; Narukawa, Tomohiro; Inagaki, Kazumi; Miyashita, Shinichi; Kotzeva, Boriana; Kakoulides, Elias; Sxoina, Vasiliki; Fung, W. H.; Choi, Y. Y.; Yau, H. P.; Tsoi, Y. T.; Lee, C. L.; Kong, M. F.; Shin, Richard; Juan, Wang; Sin Yee, Ng; Uribe, Christian; Marques Rodrigues, Janaína; Caciano de Sena, Rodrigo; Silva Dutra, Emily; Bergamaschi, Luigi; Giordani, Laura; D'Agostino, Giancarlo; Valiente, Liliana; Horvat, Milena; Jacimovic, Radojko; Oduor Okumu, Tom; Kang'Iri, Jacqueline; Owiti Orwa, Tabitha; Chao, Wei; Jingbo, Chao; Taebunpakul, Sutthinun; Yafa, Charun; Kaewkhomdee, Nattikarn; Chailap, Benjamat; Pharat, Yanee; Phukphattanachai, Pranee; Turk, Gregory C.; Long, Stephen; Murphy, K. E.; Davis, Clay; Ellisor, Michael; Merrick, Jeffrey; White, Ian; Saxby, David; Linsky, S. M.; Barzev, A.; Botha, A.
2015-01-01
The CCQM-K108 key comparison was organised by the Inorganic Analysis Working Group (IAWG) of CCQM to test the abilities of national metrology institutes (NMIs) or designated institutes (DIs) to measure the mass fractions of arsenic species, total arsenic and cadmium in brown rice flour. The National Metrology Institute of Japan (NMIJ) acted as the coordinating laboratory. The participants used different measurement methods, though most of them used inductively coupled plasma mass spectrometry (ICP-MS) or isotope-dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) for Cd and ICP-MS for total arsenic. Regarding arsenic speciation, all participants used ICP-MS coupled with liquid chromatography (LC). Accounting for relative expanded uncertainty, comparability of measurement results for each of total arsenic and cadmium was successfully demonstrated by the participating NMIs or DIs for the measurement of the measurand at the level of less than 0.5 mg/kg. Regarding arsenic species (inorganic arsenic and dimethylarsinic acid (DMAA)), there was, however, a measurement problem still to be solved and that part of CCQM-K108 will be repeated. It is expected that arsenic, cadmium and other metals at mass fractions greater than approximately 0.1 mg/kg in rice flour can be determined by each participant using the same technique(s) employed for this key comparison to achieve similar uncertainties mentioned in the present report. Furthermore, the results of this key comparison can be utilised along with the IAWG core capability approach. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Hill, K. D.; Steele, A. G.; Dedikov, Y. A.; Shkraba, V. T.
2005-01-01
The Consultative Committee for Thermometry Key Comparison 2 (CCT-K2) results were published two years ago (2002 Metrologia 39 551-71). NRC served as the pilot laboratory for CCT-K2 and remains able to provide a scale and measurement system suitable for performing bilateral comparisons linked to the original key comparison results. In March 2003, measurements of two VNIIFTRI 100 Ω capsule-style platinum resistance thermometers (CSPRTs), S/N 356 and 476, were undertaken to relate their local calibration to the results from the CCT-K2 exercise. The NRC Leeds and Northrup (L&N) CSPRT S/N 1872174 provides the link to the CCT-K2 results. The three CSPRTs were compared at the eight defining cryogenic temperatures of the International Temperature Scale of 1990 (ITS-90) in the range from 13.8033 K to 273.16 K. The reader is referred to the full text of the CCT-K2 report for a detailed explanation of the methodology employed for the comparison. Only the details unique to the measurements reported here will be addressed in this article. The NRC/VNIIFTRI bilateral comparison of capsule-style platinum resistance thermometers over the range 13.8 K to 273.16 K has revealed calibrations at VNIIFTRI to be in agreement with the KCRV of CCT-K2 within the expanded uncertainty for all temperatures of the comparison with the exception of the triple point of hydrogen at 13.8033 K. One of the two CSPRTs supplied by VNIIFTRI was found to be discrepant as revealed by differences at the triple point of water and at the lowest temperatures of the comparison, and was therefore excluded from further analysis. The linkage to the CCT-K2 data supports the evaluation of the VNIIFTRI CMCs in Appendix C of the KCDB. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions
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Report of the key-comparison of spectral diffuse reflectance (EURAMET.PR-K5) (Ref. 619)
Andor, György; Gál, Péter
2018-01-01
This report details the final results of the EURAMET comparison on regular spectral transmittance carried out between 2006 and 2016. The aim of this comparison was to check the agreement of measurement of the spectral diffuse reflectance among participants, using the measurement geometry of d/0 or 0/d in the wavelength range of 360 nm to 780 nm at 20 nm increment. We used a star type comparison: first the participants sent their samples to the pilot, than the pilot measured all the samples of the participants and sent them back. The participants measured the samples and sent them to the pilot for control measurement. Six standards were used as reference standards in order to maintain the scale during the comparison. These were three samples of BCR-406 opal glasses (BCR 30506; BCR 30303; BCR 30704), an MC20 Russian opal glass (MC 4777) and two samples made of pressed halon (polytetrafluoroethylene) powder (halon 2007A; halon 2007C). These six samples were designated as the Comparison reference standards. The diffuse reflectance was initially measured on the OMH (BFKH) absolute reflectometer. The link to the CCPR-K5 results was BFKH, and the check on BFKH was the PTB results who also participated in the CCPR-K5 comparison. The participants were GUM, INM, LNE, METAS, BFKH, PTB, SP. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCPR, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Yoshida, H.; Arai, K.; Akimichi, H.; Hong, S. S.; Song, H. W.
2011-01-01
The results of a key comparison of ultra-high vacuum standards at two national metrology institutes (NMIJ/AIST and KRISS) are reported. This bilateral comparison was carried out from May 2010 to October 2010 within the framework of the Asia-Pacific Metrology Programme (APMP) to determine their degrees of equivalence at pressures in the range from 3 × 10-6 Pa to 9 × 10-4 Pa. The pilot institute was NMIJ/AIST. Two spinning rotor gauges and two hot cathode ionization gauges were used as the transfer standards. NMIJ/AIST used two calibration systems: the dynamic expansion system (NMIJ-DES) and two-stage flow-dividing system (NMIJ-TFS). KRISS used the dynamic expansion system. The transfer standards were sufficiently stable to meet the requirements of the comparison compared with those of previous international comparisons owing to some improvements of the protocol and the transfer standards. The ultra-high vacuum standards of NMIJ/AIST and KRISS were found to be equivalent within their claimed uncertainties in the range from 3 × 10-6 Pa to 9 × 10-5 Pa. The NMIJ-DES results, which have smaller uncertainty than NMIJ-TFS, were transferred to the corresponding CCM key comparison, CCM.P-K3, in the range from 3 × 10-6 Pa to 9 × 10-5 Pa and it is shown that the NMIJ values were equivalent to the CCM key comparison reference value within the claimed uncertainties. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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The mutual recognition arrangement and primary standard dosimetry laboratory comparisons
International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Burns, D.T.
2002-01-01
the measurement capabilities of each NMI in the KCDB maintained by the BIPM. This database is available on the web at http://www.bipm.org/kcdb. The degrees of equivalence of each NMI holding national standards for a given quantity are determined from the key comparisons. These are entered into Appendix B of the MRA that is maintained as part of the KCDB. (Note that Appendix A is the list of signatories to the MRA). The results of the comparisons are analysed and presented in two ways. A graph is used to present the degree of equivalence of each NMI with the key comparison reference value (KCRV) and, secondly, a matrix is used to show the inter-laboratory degrees of equivalence taking inter-laboratory correlations into account. A CIPM key comparison is executed either by a Consultative Committee of the CIPM, such as the Consultative Committee for Ionizing Radiation (CCRI), or by the BIPM and leads to a KCRV. In certain fields, such as ionizing radiation, the BIPM maintains international standards against which NMIs (for example, the primary standards dosimetry laboratories, PSDLs that are affiliated members of the IAEA/WHO Network of SSDLs) can compare their primary standards. These comparisons may be made at any mutually convenient time and these comparisons are identified as 'BIPM ongoing key comparisons'. However, although there are over 110 comparisons listed in the field of ionizing radiation, more than 77 of these comparisons are activity comparisons (rather than dosimetry comparisons) for the many different radionuclides, that are measured using the International Reference System (SIR). The BIPM currently operates four ongoing key comparisons for ionizing radiation dosimetry. These include dosimetry comparisons for air kerma in low- and medium-energy x-ray beams and for air kerma and absorbed dose to water in 60 Co gamma radiation. The comparison result is expressed as a ratio of the NMI value for the quantity to the BIPM value and the report of the comparison
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CSIR Research Space (South Africa)
Robinson, SP
2006-09-01
Full Text Available South African Develop- ment Community Cooperation in Measurement TraceabilityH20850, and SIM H20849Sistema Interamericano de MetrologiaH20850. Also listed in Table I are the country codes used to identify the results in the graphical representations... in the database on the BIPM web- site also include tabulated data on the bilateral degrees of equivalence between the countries along with associated uncertainties. The data generated by the comparison are available on the BIPM website at H20855http...
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Li, Wang; Takahashi, C.; Hussain, F.; Hong, Yi; Nham, H. S.; Chan, K. H.; Lee, L. T.; Chahine, K.
2007-01-01
This APMP key comparison of humidity measurements using a dew point meter as a transfer standard was carried out among eight national metrology institutes from February 1999 to January 2001. The NMC/SPRING, Singapore was the pilot laboratory and a chilled mirror dew point meter offered by NMIJ was used as a transfer standard. The transfer standard was calibrated by each participating institute against local humidity standards in terms of frost and dew point temperature. Each institute selected its frost/dew point temperature calibration points within the range from -70 °C to 20 °C frost/dew point with 5 °C step. The majority of participating institutes measured from -60 °C to 20 °C frost/dew point and a simple mean evaluation was performed in this range. The differences between the institute values and the simple means for all participating institutes are within two standard deviations from the mean values. Bilateral equivalence was analysed in terms of pair difference and single parameter Quantified Demonstrated Equivalence. The results are presented in the report. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Colín, C.; Viliesid, M.; Chaudhary, K. P.; Decker, J.; Dvorácek, F.; Franca, R.; Ilieff, S.; Rodríguez, J.; Stoup, J.
2012-01-01
reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Energy Technology Data Exchange (ETDEWEB)
Michotte, C.; Courte, S.; Ratel, G. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Moune, M. [LNE-LNHB, Laboratoire national de metrologie et d' essais-Laboratoire National Henri Becquerel, Gif sur Yvette (France); Johansson, L.; Keightley, J. [National Physical Laboratory (NPL), Middlesex (United Kingdom)
2010-12-15
In 2007 and 2008 respectively, the Laboratoire national de metrologie et d'essais -Laboratoire national Henri Becquerel (LNE-LNHB), France and the National Physical Laboratory (NPL), UK, submitted ampoules with between 10 MBq and 130 MBq activity of {sup 99m}Tc to the International Reference System (SIR), to update their results in the BIPM.RI(II)-K1.Tc-99m comparison. Together with the four other national metrology institutes (NMI) that are participants, thirteen samples have been submitted since 1983. The key comparison reference value (KCRV) has been recalculated to include the latest primary results of the PTB and the LNE-LNB as this makes the evaluation more robust. The degrees of equivalence between each equivalent activity measured in the SIR are given in the form of a matrix for all six NMIs. A graphical presentation is also given. (authors)
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Pokhodun, A. I.
2010-01-01
In the framework of the CIPM MRA, a first COOMET comparison "Comparison of the ITS-90 realizations in the range from 0.01 °C to 429.7485 °C (from the triple point of water to the freezing point of zinc)", registered in the KCDB under the identifier "COOMET.T-K3", was carried out in 2005-2007. Four national metrology institutes took part in this comparison: VNIIM (Russian Federation), SMU (Slovakia), BelGIM (Republic of Belarus) and NSC IM (Ukraine), and two of them (VNIIM and SMU) ensured the linkage with key comparisons CCT-K3 and CCT-K4, in order to disseminate the metrological equivalence to the measurement standards of NSC IM and BelGIM. NSC IM, however, had to withdraw its results, and at the meeting of Technical Committee T-10 of COOMET it was decided to carry out a supplementary bilateral comparison between VNIIM and the NSC IM for realization of the ITS-90 in the same range of temperature. This was registered in the KCDB under the identifier COOMET.T-S1 and measurements were performed in 2008-2009. From the results presented in this report, it is possible to draw the conclusion that the COOMET supplementary comparison COOMET.T-S1 demonstrates the CMC uncertainties claimed by the NSC IM for the melting point of gallium 0.236 mK (k = 2), and the freezing points of indium 1.040 mK (k = 2), tin 0.858 mK (k = 2) and zinc 0.944 mK (k = 2). In September 2012 the Working Group on key Comparisons (WG 7) of the CCT upgraded this comparison to a COOMET key comparison of the 'CCT-K3' type. It is now identified as COOMET.T-K3.1. In April 2013 this report was superseded by item 03006 in the Technical Supplement of 2013. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Pozdeeva, Valentina; Chalyy, Vladimir
2014-01-01
The supplementary comparison COOMET.AUV.A-S1 for secondary calibration methods using WS1 and WS2 measurement microphones was carried out from 2009 to 2010. The results were submitted to and approved by CCAUV in April 2014. Four National Metrology Institutes took part in this comparison and are as follows: BelGIM (Belarus), VNIIFTRI (Russia), SMU (Slovakia) and DP NDI 'Sistema' (Ukraine). Three of the above NMIs (VNIIFTRI, SMU and DP NDI 'Sistema') had earlier participated in COOMET key comparisons and one NMI (VNIIFTRI) had also participated in CCAUV key comparisons. The Comparison Reference Values were calculated as the weighted mean values from results obtained by three institutes. The comparison results show agreement for all participants in the frequency range from 20 Hz to 12.5 kHz for WS1 microphones, and in the frequency range from 20 Hz to 16 kHz for WS2 microphones. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Morales, Abed; Quiroga, Aldo; Daued, Arturo; Cantero, Diana; Sequeira, Francisco; Castro, Luis Carlos; Becerra, Luis Omar; Salazar, Manuel; Vega, Maria
2017-01-01
A supplementary comparison was made between SIM laboratories concerning the calibration of four hydrometers within the range of 600 kg/m3 to 2000 kg/m3. The main objectives of the comparison were to evaluate the degree of equivalences SIM NMIs in the calibration of hydrometers of high accuracy. The participant NMIs were: CENAM, IBMETRO, INEN, INDECOPI, INM, INTN and LACOMET. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Lorefice, Salvatore; Malta, Dalni; Julio Pinheiro, José; Marteleto, Paulo Roberto
2010-01-01
The results of the SIM.M.D-S2 bilateral comparison between INRIM-Italy and INMETRO-Brazil are summarized in this report. The aims of this comparison were to check the stated uncertainty levels and the degrees of equivalence between the two institutes on the calibration of hydrometers for liquid density in the range of 800 kg m-3 to 1000 kg m-3 at 20 ºC, by means of two transfer standards of excellent metrological characteristics. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Schantz, Michele M.; Duewer, David L.; Parris, Reenie M.; May, Willie E.; Archer, Marcellé; Mussell, Chris; Carter, David; Konopelko, Leonid A.; Kustikov, Yury A.; Krylov, Anatoli I.; Fatina, Olga V.
2005-01-01
Ethanol is important both forensically ('drunk driving' or driving while under the influence, 'DWI', regulations) and commercially (alcoholic beverages). Blood- and breath-alcohol testing can be imposed on individuals operating private vehicles such as cars, boats, or snowmobiles, or operators of commercial vehicles like trucks, planes, and ships. The various levels of blood alcohol that determine whether these operators are considered legally impaired vary depending on the circumstances and locality. Accurate calibration and validation of instrumentation is critical in areas of forensic testing where quantitative analysis directly affects the outcome of criminal prosecutions, as is the case with the determination of ethanol in blood and breath. Additionally, the accurate assessment of the alcoholic content of beverages is a commercially important commodity. In 2002, the CCQM conducted a Key Comparison (CCQM-K27) for the determination of ethanol in aqueous matrix with nine participants. A report on this project has been approved by the CCQM and can be found at the BIPM website and in this Technical Supplement. CCQM-K27 comprised three samples, one at low mass fraction of ethanol in water (nominal concentration of 0.8 mg/g), one at high level (nominal concentration of 120 mg/g), and one wine matrix (nominal concentration of 81 mg/g). Overall agreement among eight participants using gas chromatography with flame ionization detection (GC-FID), titrimetry, isotope dilution gas chromatography/mass spectrometry (GC-IDMS), and gas chromatography-combustion-isotope ratio mass spectrometry (ID-GC-C-IRMS) was good. The ninth participant used a headspace GC-FID method that had not been validated in an earlier pilot study (CCQM-P35). A follow-on Key Comparison, CCQM-K27-Subsequent, was initiated in 2003 to accommodate laboratories that had not been ready to benchmark their methods in the original CCQM-K27 study or that wished to benchmark a different method. Four levels of
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Becerra, Luis Omar; Lorefice, Salvatore
2009-01-01
Hydrometers are instruments usually made of glass which are widely used for different levels of precision to measure liquid density and related quantities to control different products and processes. This bilateral comparison on the calibration of hydrometers shows that results reported by CENAM-Mexico and INRIM-Italy are consistent within the claimed uncertainty in the range of 800 kg/m3 to 1200 kg/m3. This bilateral comparison is intended to link the two regional comparisons SIM.M.D-K4 and EURAMET.D-K4. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Results of the EURAMET.RI(II)-S6.I-129 supplementary comparison
García-Toraño, Eduardo; Altzitzoglou, Timotheos; Auerbach, Pavel; Bé, Marie-Martine; Lourenço, Valérie; Bobin, Christophe; Cassette, Philippe; Dersch, Rainer; Kossert, Karsten; Nähle, Ole; Peyrés, Virginia; Pommé, Stefaan; Rozkov, Andrej; Sanchez-Cabezudo, Anabel; Sochoro&vacute; , Jana
2015-01-01
An international comparison of the long-lived gamma-ray emitter 129I has been recently completed. A total of 5 laboratories measured a solution prepared by Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT). Aliquots of the master solution were standardized in terms of activity per mass unit by participant laboratories using 4 different techniques. The results of the comparison can be used as the basis for establishing the equivalence among the laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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SUPPLEMENTARY COMPARISON: COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison
Skliarov, V.; Röttger, A.; Honig, A.; Korostin, S.; Kuznetsov, S.; Lapenas, A.; Milevsky, V.; Ivaniukovich, A.; Kharitonov, I.; Sepman, S.
2009-01-01
According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5th meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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International comparison of AC-DC current transfer standards
Heine, G.; Garcocz, M.; Waldmann, W.
2017-01-01
The measurements of the international comparison of ac-dc current transfer standards identified as EURAMET.EM-K12 started in June 2012 and were completed in December 2014. Twenty NMIs in the EURAMET region and one NMI in the AFRIMET region took part: BEV (Austria), CMI (Czech Republic), PTB (Germany), METAS (Switzerland), JV (Norway), UME (Turkey), GUM (Poland), IPQ (Portugal), CEM (Spain), INRIM (Italy), SP (Sweden), DANIAmet-MI-Trescal (Denmark), BIM (Bulgaria), MKEH (Hungary), SIQ (Slovenia), LNE (France), NSAI NML (Ireland), VSL (The Netherlands), NPL (United Kingdom), Metrosert (Estonia), NIS (Egypt). The comparison was proposed to link the National Metrology Institutes organised in EURAMET to the key comparison CCEM-K12. The ac-dc current transfer difference of each travelling standard had been measured at its nominal current 10 mA and 5 A at the following frequencies: 10 Hz, 55 Hz, 1 kHz, 10 kHz, 20 kHz, 50 kHz, 100 kHz. The test points were selected to link the results with the equivalent CCEM Key Comparison (CCEM-K12), through five NMIs participating in both EURAMET and CCEM key comparisons (PTB, JV, NPL, SP and BEV). The report shows the degree of equivalence in the EURAMET region and also the degree of equivalence with the corresponding CCEM reference value. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Chalyy, V.
2011-01-01
A bilateral regional comparison of national microphone standards from 2 Hz to 250 Hz was carried out between the DP NDI 'Systema' (Ukraine) and the VNIIFTRI (Russia) from July to September 2009. The comparison, COOMET.AUV.A-K2, was based on the pressure calibration of laboratory standard microphones type LSIP. The comparison results have been linked to the established key comparison reference value (KCRV) of CCAUV.A-K2. The degrees of equivalence, expressed as the deviation from the established KCRV and its expanded uncertainty (k = 2), have been determined, and the comparison result is in agreement with the KCRV within the estimated uncertainties at all employed frequencies. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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International Nuclear Information System (INIS)
Iwahara, A.; Tauhata, L.; Silva, C.J. da
2014-01-01
The Radionuclide Metrology Laboratory (LMR) of LNMRI/IRD has been participating since 1984, in international key-comparisons of activity measurement of radioactive sources organized by BIPM and the Regional Metrology Organizations as EURAMET and APMP. The measured quantity is the activity of a radioactive solution, in becquerel (Bq), containing the radionuclide involved and the of measurement methods used are 4αβ-γ coincidence/anticoincidence, coincidence sum-peak and liquid scintillation. In this paper a summary of the methods used and a performance analysis of the results obtained are presented. (author)
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Comparison of measurement capability with 100 μmol/mol of carbon monoxide in nitrogen
Lee, Jeongsoon; Lee, JinBok; Lim, Jeongsik; Tarhan, Tanıl; Liu, Hsin-Wang; Aggarwal, Shankar G.
2018-01-01
Carbon monoxide (CO) in nitrogen was one of the first types of gas mixtures used in an international key comparison. The comparison dates back to 1998 (CCQMK1a) [1]. Since then, many National Metrology Institutes (NMIs) have developed calibration and measurement capabilities (CMCs) for these mixtures. Recently, NMIs in the APMP region have actively participated in international comparisons to provide domestic services. At the 2013 APMP meeting, several NMIs requested a CO comparison to establish CO/N2 certification for industrial applications, which was to be coordinated by KRISS. Consequently, this comparison provides an opportunity for APMP regional NMIs to develop CO/N2 CMC claims. The goal of this supplementary comparison is to support CMC claim for carbon monoxide in the N2 range of 50–2000 μmol/mol. An extended range may be supported as described in the GAWG strategy for comparisons and CMC claims. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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KEY COMPARISON: Final report on CCQM-K62: Nutrients in infant/adult formula—Vitamins
Sharpless, Katherine E.; Rimmer, Catherine A.; Phinney, Karen W.; Nelson, Bryant C.; Duewer, David L.; Wise, Stephen A.; Kim, Byungjoo; Liu, Jun; Huang, Ting; Zhang, Wei
2010-01-01
and vitamin A and one of the three results for folic acid was withdrawn, no strong conclusions as to the expected comparability of higher-order vitamin measurements can be established. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Angle comparison using an autocollimator
Geckeler, Ralf D.; Just, Andreas; Vasilev, Valentin; Prieto, Emilio; Dvorácek, František; Zelenika, Slobodan; Przybylska, Joanna; Duta, Alexandru; Victorov, Ilya; Pisani, Marco; Saraiva, Fernanda; Salgado, Jose-Antonio; Gao, Sitian; Anusorn, Tonmueanwai; Leng Tan, Siew; Cox, Peter; Watanabe, Tsukasa; Lewis, Andrew; Chaudhary, K. P.; Thalmann, Ruedi; Banreti, Edit; Nurul, Alfiyati; Fira, Roman; Yandayan, Tanfer; Chekirda, Konstantin; Bergmans, Rob; Lassila, Antti
2018-01-01
Autocollimators are versatile optical devices for the contactless measurement of the tilt angles of reflecting surfaces. An international key comparison (KC) on autocollimator calibration, EURAMET.L-K3.2009, was initiated by the European Association of National Metrology Institutes (EURAMET) to provide information on the capabilities in this field. The Physikalisch-Technische Bundesanstalt (PTB) acted as the pilot laboratory, with a total of 25 international participants from EURAMET and from the Asia Pacific Metrology Programme (APMP) providing measurements. This KC was the first one to utilise a high-resolution electronic autocollimator as a standard. In contrast to KCs in angle metrology which usually involve the full plane angle, it focused on relatively small angular ranges (+/-10 arcsec and +/-1000 arcsec) and step sizes (10 arcsec and 0.1 arcsec, respectively). This document represents the approved final report on the results of the KC. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International comparison CCQM-K119 liquefied petroleum gas
Brewer, P. J.; Downey, M. L.; Atkins, E.; Brown, R. J. C.; Brown, A. S.; Zalewska, E. T.; van der Veen, A. M. H.; Smeulders, D. E.; McCallum, J. B.; Satumba, R. T.; Kim, Y. D.; Kang, N.; Bae, H. K.; Woo, J. C.; Konopelko, L. A.; Popova, T. A.; Meshkov, A. V.; Efremova, O. V.; Kustikov, Y.
2018-01-01
Liquefied hydrocarbon mixtures with traceable composition are required in order to underpin measurements of the composition and other physical properties of LPG (liquefied petroleum gas), thus meeting the needs of an increasingly large industrial market. This comparison aims to assess the analytical capabilities of laboratories for measuring the composition of a Liquid Petroleum Gas (LPG) mixture when sampled in the liquid phase from a Constant Pressure Cylinder. Mixtures contained ethane, propane, propene, i-butane, n-butane, but-1-ene and i-pentane with nominal amount fractions of 2, 71, 9, 4, 10, 3 and 1 cmol mol-1 respectively. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Stone, Mark H; Stenner, A Jackson
2014-01-01
Several concepts from Georg Rasch's last papers are discussed. The key one is comparison because Rasch considered the method of comparison fundamental to science. From the role of comparison stems scientific inference made operational by a properly developed frame of reference producing specific objectivity. The exact specifications Rasch outlined for making comparisons are explicated from quotes, and the role of causality derived from making comparisons is also examined. Understanding causality has implications for what can and cannot be produced via Rasch measurement. His simple examples were instructive, but the implications are far reaching upon first establishing the key role of comparison.
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International Nuclear Information System (INIS)
Burns, D.T.
2002-01-01
Traditionally, the correction factor k wall for attenuation and scatter in the walls of cavity ionization chamber primary standards has been evaluated experimentally using an extrapolation method. During the past decade, there have been a number of Monte Carlo calculations of k wall indicating that for certain ionization chamber types the extrapolation method may not be valid. In particular, values for k wall have been proposed that, if adopted by each laboratory concerned, would have a significant effect on the results of international comparisons of air-kerma primary standards. The calculations have also proposed new values for the axial component k an of the point-source uniformity correction. Central to the results of international comparisons is the BIPM air-kerma standard. Unlike most others, the BIPM standard is of the parallel-plate design for which the extrapolation method for evaluating k wall should be valid. The value in use at present is k wall =1.0026 (standard uncertainty 0.0008). Rogers and Treurniet calculated the value k wall =1.0014 for the BIPM standard, which is in moderate agreement with the value in use (no overall uncertainty was given). However, they also calculated k an =1.0024 (statistical uncertainty 0.0003) which is very different from the value k an =0.9964 (0.0007) in use at present for the BIPM standard. A new 60 Co facility has recently been installed at the BIPM and the opportunity was taken to re-evaluate the correction factors for the BIPM standard in this new beam. Given that almost all of the Monte Carlo work to date has used the EGS Monte Carlo code, it was decided to use the code PENELOPE. The new source, container, head and collimating jaws were simulated in detail with more that fifty components being modelled, as shown. This model was used to create a phase-space file in the plane 90 cm from the source. The normalized distribution of photon number with energy is shown, where the various sources of scattered photons are
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Bell, S.; Stevens, M.; Abe, H.; Benyon, R.; Bosma, R.; Fernicola, V.; Heinonen, M.; Huang, P.; Kitano, H.; Li, Z.; Nielsen, J.; Ochi, N.; Podmurnaya, O. A.; Scace, G.; Smorgon, D.; Vicente, T.; Vinge, A. F.; Wang, L.; Yi, H.
2015-01-01
A key comparison in dew-point temperature was carried out among the national standards held by NPL (pilot), NMIJ, INTA, VSL, INRIM, MIKES, NIST, NIM, VNIIFTRI-ESB and NMC. A pair of condensation-principle dew-point hygrometers was circulated and used to compare the local realisations of dew point for participant humidity generators in the range -50 °C to +20 °C. The duration of the comparison was prolonged by numerous problems with the hygrometers, requiring some repairs, and several additional check measurements by the pilot. Despite the problems and the extended timescale, the comparison was effective in providing evidence of equivalence. Agreement with the key comparison reference value was achieved in the majority of cases, and bilateral degrees of equivalence are also reported. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Final report on international comparison CCQM-K83: Halocarbons in dry whole air
Rhoderick, George; Guenther, Franklin; Duewer, David; Lee, Jeongsoon; Moon, Dongmin; Lee, Jinbok; Lim, Jeongsik; Seog Kim, Jin
2014-01-01
The growing awareness of climate change/global warming and continuing concerns regarding stratospheric ozone depletion will require future measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track and control the emissions of these species globally in the atmosphere, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. This report describes the results of a key comparison for several of the more important halocarbons at atmospheric concentration levels. The comparison includes the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC 12), trichlorofluoromethane (CFC 11), and 1,1,2 trichlorotrifluoroethane (CFC 113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC 22) and 1-chloro-1,1-difluoroethane (HCFC 142b); and the hydrofluorocarbon (HFC) 1,1,1,2 tetrafluoroethane (HFC 134a), all in a dried whole air sample. The objective of this key comparison is to compare the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Mautjana, R. T.; Molefe, P. T.; Mayindu, N. F.; Armah, M. N.; Ramasawmy, V.; Albasini, G. L.; Matali, S.; Richmond, H.; Rusimbi, V.; Kiwanuka, J.; Mutale, D. M.; Mutsimba, F.
2018-01-01
This report summarizes the results of AFRIMETS.M.M-S6 mass standards comparison conducted between eleven participating laboratories/countries. Two sets of five weights with nominal values 100 mg, 100 g, 500 g, 1 kg and 5 kg were used as the traveling standards. These nominal values were decided from the needs of participating laboratories submitted to the pilot laboratory through a questionnaire and agreed upon by all participants. The traveling standards were hand carried between laboratories starting from February 2014 and were received from the last participants in October 2014. The programme was coordinated by National Metrology Institute of South Africa (NMISA), who provided the travelling standards and reference values for the comparison. The corrections to the BIPM as-maintained mass unit [5] have insignificant influence on the results of this comparison. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Report on NIM-NMC bilateral comparison: SPRT calibration comparison from -190°C to 420°C
Sun, Jianping; Ye, Shaochun; Wang, Li; Zhang, Jintao; Kho, Haoyuan
2016-01-01
A bilateral comparison of local realization of the International temperature scale of 1990 (ITS-90) between National Institute of Metrology (NIM) and National Metrology Centre (NMC) was carried out over the temperature range from -190°C to 420°C. It involved six fixed points including the argon triple point, the mercury triple point, the triple point of water, the melting point of gallium, the freezing point of tin and the freezing point of zinc. In 2009, NMC asked NIM to participate in a bilateral comparison to link the NMC results to the Consultative Committee for Thermometry Key comparison 3 (CCT-K3) and facilitate the NMC's Calibration and measurement capabilities (CMCs) submission. This comparison was agreed by NIM and Asia Pacific Metrology Programme (APMP) in 2009, and registered in the Key Comparison Database (KCDB) in 2010 as CCT-K3.2. NMC supplied two 25 Ω fused silica sheath standard platinum resistance thermometers (SPRTs) as traveling standards. One of them was used at the Ga, Sn and Zn fixed points, while the other one was used at the Ar and Hg fixed point. NMC measured them before and after NIM measurement. During the comparison, a criterion for the SPRT was set as the stability at the triple point of water to be less than 0.3 mK. The results for both laboratories are summarized. A proposal for linking the NMC's comparison results to CCT-K3 is presented. The difference between NMC and NIM and the difference between NMC and the CCT-K3 Average Reference Value (ARV) using NIM as a link are reported with expanded uncertainties at each measured fixed point. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Bell, David; Hopley, Chris; Ellison, Stephen L. R.; O'Connor, Gavin
2013-01-01
equivalence of participants in CCQM-K12. The range of participants' results in EURAMET.QM-K12 for both levels (2% and 3% respectively for materials A and B) was greater than the 1% achieved in CCQM-K12. However, it was concluded that this study was suitable to support CMCs for creatinine in serum for 1 µg/g to 100 µg/g with uncertainties at the 1% to 1.5% level. This was found to be fit for purpose and consistent with the majority of CMCs currently approved. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Lorefice, S.; Becerra, L. O.
2017-01-01
Evaluation of different types of comparisons to a common set of reference values of a CIPM key comparison is essential to satisfy the concept of the CIPM Mutual Recognition Arrangement (CIPM MRA), where the DoEs of any participant who took part in comparisons should be within the Calibration and Measurement Capability (CMC) section of the CIPM MRA Key Comparison Data Base. The subject of this supplementary report is therefore to present the equivalence of each National Metrological Institute (NMI) participant in the CCM.D-K4 'Hydrometer' key comparison, which was performed in the density range 600 kg/m3 to 2000 kg/m3 at the temperature of 20 °C, and the linkage of the European and Inter-American NMI results performed in the RMO.M.D-K4 comparisons as well as those of the supplementary SIM.M.D-S2 to the common set of KCRVs of the CCM.D-K4 'Hydrometer'. The linking procedure has been obtained by numerical simulation, based on the Monte Carlo method, in which the differences in the results of the different comparison between the intended laboratory and one or more linking laboratory/ies, which took part in both comparisons, are correlated with a continuous function describing the DoEs of the linking laboratory/ies with respect to the common set of KCRVs of the CCM.D-K4. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Final report on SIM.T-S2: Comparison of the calibration of 100 Ω platinum resistance thermometers
del Campo, D.; Chimenti Ruiz, V.; Méndez-Lango, E.; Córdova, L.; von Borries, E.; Sánchez, C. A.; Arévalo, A.; Aguilera, B.; Guillén, E.; Cabrera, C.; Quintana, L.
2013-01-01
An International Comparison on industrial platinum resistance thermometers (PRTs) among the National Metrology Institutes (NMIs) of Spain, Mexico and the Andean Countries (Bolivia, Colombia, Ecuador, Peru and Venezuela) began in 2004 and was successfully completed in 2005. Two PRTs were circulated (hand-carried) and compared from -40 °C up to 250 °C. The Centro Español de Metrología (Spanish NMI), CEM, was the pilot laboratory and the Centro Nacional de Metrología (Mexican NMI), CENAM, was the co-pilot laboratory. This report presents the results of this comparison and provides detailed information of the measurements performed by the participating laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Final report on bilateral comparison EURAMET.M.T-S3: Torque wrenches (10 N m - 1 kN m)
Röske, Dirk; Medina, Nieves
2011-01-01
A bilateral comparison from 10 N m up to 1000 N m has been carried out between Physikalisch-Technische Bundesanstalt (PTB) and Centro Español de Metrología (CEM) for reference torque wrenches calibrated according to DKD-R 3-7. The transfer standards have been two reference torque wrenches, 10 N m and 1000 N m respectively, that have been measured between November and December 2010. The results presented here demonstrate the metrological equivalence, within the quoted uncertainties, of both participant laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Recent progress on the BIPM watt balance
Directory of Open Access Journals (Sweden)
Fang Hao
2014-01-01
Full Text Available We present the recent progress on the BIPM (Bureau International des Poids et Mesures watt balance. The existing apparatus was transferred to the dedicated new laboratory with better thermal and vibrational conditions. The apparatus is fully operational in air. An improvement by a factor of three was achieved on the S/N ratio of both the voltage-to-velocity and force-to-current ratios. The fabrication of the parts of the new magnet is completed and its assembly is finished.
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Final report of the key comparison CCQM-K106: Pb, As and Hg measurements in cosmetic (cream)
Wang, Jun; Wang, Qian; Yamani, Randa Nasr Ahmed; Shehata, Adel B.; Jacimovic, Radojko; Pavlin, Majda; Horvat, Milena; Tsoi, Y. P.; Tsang, C. K.; Shin, Richard; Chailap, Benjamat; Yafa, Charun; Caciano de Sena, Rodrigo; de Almeida, Marcelo; Yim, Yong-Hyeon; Lee, Kyoung-Seok; Heun Kim, Sook; Konopelko, Leonid; Ari, Betül; Tokman, Nilgün; Rienitz, Olaf; Jaehrling, Reinhard; Pape, Carola
2015-01-01
which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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S-C Tai, Susan; Duewer, David L.
2010-01-01
/MS-based cortisol results is 100.4 ng/g with a relative standard deviation (%RSD) of 1.1%. The mean value for the seven ID/MS-based progesterone originally reported results is 2.83 with a %RSD of 1.8%. While a number of the reported results were not eligible to be used in establishing the KCRVs, the KCRVs as estimated from just the eligible results agree very well with these means. The excellent among-participant agreement indicates that ID/MS-based measurement procedures can provide precise and true results for steroid hormones at levels greater than about 1 ng/g. The progesterone result reported by a laboratory using a non-isotopically labelled internal standard was about 11% larger than the KCRV. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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Heinonen, Martti; Zvizdic, Davor; Sestan, Danijel
2013-01-01
As the European extension of the first CCT humidity key comparison, EUROMET.T-K6 was successfully completed in year 2008. After this comparison, a new low dew-point generator was introduced at LPM in Croatia as a result of progress in the EUROMET P912 project. With this new facility, the LPM uncertainties decreased significantly and the operating range became significantly wider. Therefore, it was decided to arrange a bilateral comparison between LPM and MIKES in Finland providing a link to EUROMET.T-K6 and CCT-K6. This comparison was carried out in a manner similar to other K6 comparisons but only one transfer standard was used instead of two units and the measurement point -70 °C was added to the measurement scheme. At all measurement points, the bilateral equivalence was well within the estimated expanded uncertainty at the approximately 95% confidence level. Also, the deviations of the LPM results from the EUROMET.T-K6 reference values were smaller than their expanded uncertainties. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Nuclear Information System (INIS)
Yamasaki, Shigemichi; Ishikura, Hiroyasu; Kamitani, Takanori
2011-01-01
Continuous regional arterial infusion (CRAI) therapy using both protease inhibitors and antibiotics are one of the specific therapeutic methods for severe acute pancreatitis (SAP). As for the administered antibiotics, imipenem/cilastatin sodium (IPM/CS) is generally chosen as a first step, but there are only a few reports comparing IPM/CS with other antibiotics. Therefore, we performed a prospective randomized controlled trial between biapenem (BIPM) and IPM/CS as CRAI antibiotics. Twelve patients with SAP were admitted to our institution during April, 2009 since August, 2006, and were randomized into two groups. They were treated with 120 mg/day of nafamostat mesilate and either 1.2 g/day of BIPM (n=6) or 2.0 g/day of IPM/CS (n=6) for CRAI therapy within 48 hours after the administration. The clinical data, inflammatory markers (WBC, CRP), serum pancreatic enzymes (lipase, tripsin, phospholipase A2, elastase 1 and pancreatic secretory trypsin inhibitor (PSTI) and contrast-enhanced abdominal Computed Tomography findings were compared between the two groups and the adverse effects were monitored. CRAI therapy was performed for seven days. The curative effect of this therapy was evaluated at the beginning of the treatment, the day 7 and the day 14. Our results suggested that BIPM was a non-recessive antibiotic which had an equal effect in CRAI therapy in comparison with IPM/CS. (author)
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Comparison of GPS and GLONASS Common-View Time Transfers
1992-12-01
interest as an excellent additional source. For the past three years VNIIFTRI (Mendeleevo, Moscow Region, Russian Federation) and some other Russian time...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 comparisons. Since June 1991, VNIIFTRI has operated a commercial GPS time receiver on...loan from the BIPM. Since February 1992, the BIPM has operated Russian GLONASS receiver on loan from the VNIIFTRI . Thii provides, for the first time
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Measuring conditions used for the calibration of ionization chambers at the BIPM
International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Burs, D.T.; Kessler, C.
2004-12-01
Information is presented on the experimental conditions used at the BIPM in the x- and γ-radiation beams for the calibration of secondary standards in terms of air kerma, absorbed dose in water and ambient dose equivalent, together with the uncertainties involved in the determination of these dosimetric quantities. (authors)
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EURAMET.M.P-S9: comparison in the negative gauge pressure range -950 to 0 hPa
Saxholm, S.; Otal, P.; AltintaS, A.; Bermanec, L. G.; Durgut, Y.; Hanrahan, R.; Kocas, I.; Lefkopoulos, A.; Pražák, D.; Sandu, I.; Åetina, J.; Spohr, I.; Steindl, D.; Tammik, K.; Testa, N.
2016-01-01
registered as EURAMET project no. 1170 and as a supplementary comparison EURAMET.M.P-S9 in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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CCQM-K90, formaldehyde in nitrogen, 2 μmol mol-1 Final report
Viallon, Joële; Flores, Edgar; Idrees, Faraz; Moussay, Philippe; Wielgosz, Robert Ian; Kim, D.; Kim, Y. D.; Lee, S.; Persijn, S.; Konopelko, L. A.; Kustikov, Y. A.; Malginov, A. V.; Chubchenko, I. K.; Klimov, A. Y.; Efremova, O. V.; Zhou, Z.; Possolo, A.; Shimosaka, T.; Brewer, P.; Macé, T.; Ferracci, Valerio; Brown, Richard J. C.; Aoki, Nobuyuki
2017-01-01
uncertainty of the trend parameters, as well as how the dispersion of the dates when measurements were made by the participants was taken into account. Upon decision of the participants, the Key Comparison Reference Values were assigned by the BIPM using the largest uncertainty for measurements performed at the BIPM, linear regression without weight to calculate the trend parameters, and not taking into account the dispersion of dates for measurements made by the participant. Each transfer standard was assigned its own reference value and associated expanded uncertainty. An expression for the degree of equivalence between each participating institute and the KCRV was calculated from the comparison results and measurement uncertainties submitted by participating laboratories. Results of the alternative mathematical treatment are presented in annex of this report. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Comparison of Methane-Stabilized He-Ne Lasers
Koshelyaevskii, N. B.; Oboukhov, A.; Tatarenkov, V. M.; Titov, A. N.; Chartier, J.-M.; Felder, R.
1981-01-01
Two portable methane-stabilized lasers designed at BIPM have been compared with a type a stationary Soviet device developed in VNIIFTRI1. This comparison is one of a series aimed at establishing the coherence of laser wavelength and frequency measurements throughout the world and took place in June 1979. The VNIIFTRI and BIPM lasers using different methods of stabilization, have different optical and mechanical designs and laser tubes. The results of previous measurements, made in VNIIFTRI, of the most important frequency shifts for Soviet lasers together with a method of reproducing their frequency which leads to a precision of 1.10-12 are also presented.
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Norranim, Uthai; Nguyen, Mong Kim; Ballico, Mark J.
2007-01-01
Industrial thermometers such as industrial platinum resistance thermometers (iprts) and liquid-in-glass thermometers (LIGTs) are widely used in industry. Because Key Comparisons are limited to direct realizations of ITS-90, and not all APMP NMIs have participated in them, the national metrology institutes (NMIs) of Thailand and Australia (NIMT and NIMA) organized an APMP supplementary comparison to support the approval of CMCs (calibration and measurement capabilities) for these laboratories. The comparison, performed in 2003, covered the range from -40.0 °C to 250.0 °C, using IPRTs (Hart Scientific 5626-12-S), total immersion (ASTM 62C, 120C) and partial immersion (ASTM 40C) LIGTs. Ten NMIs from the APMP: KIM-LIPI (Indonesia), ITDI (Philippines), MSL (New Zealand), NBSM (Nepal), NMIA (Australia), NIMT (Thailand), SCL (Hong Kong), SIRIM (Malaysia), SPRING (Singapore) and VMI (Vietnam) were divided into two loops to shorten the circulation time, and these were linked by the two pilot laboratories. This report describes details of the artifacts, the circulation schedule, the measurement procedures, the results submitted by participants, uncertainties and the analysis of the results. Reference values calculated using simple mean, median and weighted mean were consistent with each other, but as the Birge criterion was satisfied, the weighted mean with its lower uncertainty was adopted. The artifacts were found to be stable over the comparison and the results of the loop linking labs consistent, allowing an uncertainty of 2 mK to 4 mK to be achieved for the IPRT reference value and 10 mK to 20 mK for the LIGT reference values. These uncertainties allowed the comparison data to be used to adequately test the uncertainties of all the participant laboratories, and hence to directly support their CMC claims. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database
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Torres-Guzman, Jorge; Forastieri, Juan; Zúñiga, Sinuhé
2011-01-01
A differential pressure comparison was performed between CENAM (Mexico) and INTI (Argentina) by means of a liquid column manometer. The measuring range was 50 Pa to 500 Pa. CENAM calibrated the transfer standard at the beginning and at the end of the comparison. The transfer standard used was a Dwyer liquid column manometer model Microtector with an accuracy class of 0.013% of the reading. The compared pressure points were (50, 75, 125, 200, 250, 300, 350, 400, 450, 500) Pa. The uncertainty sources to be evaluated included at least the following: (a) uncertainty due to the standard used by the laboratory; (b) uncertainty due to repeatability; (c) uncertainty due to resolution; (d) uncertainty due to hysteresis; (e) uncertainty due to zero drift. The criteria used to compare the results obtained were the normalized error equation (En). The results obtained by the laboratories were compatible according to the criteria |En| <= 1. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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BIPM project: Intercomparison of water triple-point cells
Chattle, M. V.; Butler, J.
1994-12-01
The paper presents the results of an intercomparison between 3 triple point of water cells circulated by the Bureau International des Poids et Measures (BIPM), and a cell which is one of those used as a reference cell at the National Physical Laboratory (NPL). All 4 cells were prepared, stored and measured in the manner normally adopted at NPL. The results of the intercomparison show that over the course of about 6 weeks the temperatures of the 3 circulated cells generally agreed within 0.20 mK, with a maximum difference of 0.27(7) mK. Over the same period, the total variations of temperature measured in the 3 individual cells were 0.04 mK, 0.08 mK and 0.18 mK, respectively; the NPL cell varied by 0.10 mK. Gallium point measurements made over a similar period confirmed that these differences were partly due to small drifts in the thermometer resistance or in the measuring system.
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International Nuclear Information System (INIS)
Allisy-Roberts, P.J.; Thomas, C.; Shortt, K.R.; Meghzifene, A.
2003-01-01
This paper presents the background, history and current operation of the arrangement for the mutual recognition of national measurement standards and of calibration and measurement certificates issued by national metrology institutes (MRA). The organization of key comparisons and the operation of the BIPM key comparison database resulting from the MRA are described and the relevant roles of the International Committee, the regional metrology organizations and the IAEA are outlined. (author)
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Merlet, S.; Bodart, Q.; Malossi, N.; Landragin, A.; Pereira Dos Santos, F.; Gitlein, O.; Timmen, L.
2010-08-01
We report a comparison between two absolute gravimeters: the LNE-SYRTE cold atom gravimeter and FG5#220 of Leibniz Universität of Hannover. They rely on different principles of operation: atomic and optical interferometry. Both are movable which enabled them to participate in the last International Comparison of Absolute Gravimeters (ICAG'09) at BIPM. Immediately after, their bilateral comparison took place in the LNE watt balance laboratory and showed an agreement of (4.3 ± 6.4) µGal.
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Darnedde, H.; Rowley, W.R.C.; Bertinetto, F.; Millerioux, Y.; Haitjema, H.; Wetzels, S.F.C.L.; Piree, H.; Prieto, E.; Perez, M.Mar; Vaucher, B.; Chartier, A.; Chartier, J.M.
1999-01-01
This paper reports the fourth set of results of a series of grouped laser comparisons from national laboratories undertaken by the Bureau International des Poids et Mesures (BIPM) at the request of the Comite Consultatif pour la Definition du Metre (CCDM; now the Consultative Committee for Length,
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Mohns, Enrico; Sychev, Y.; Roeissle, G.
2014-01-01
A bilateral comparison of the measurement of current transformers was carried out between UNIIM (Russia) and PTB (Germany). For all of the current ratio error measurements and the phase displacement measurements there is a close agreement between PTB and UNIIM. Extensive measurements with the travelling standards were carried out at 18 different current ratios and at 5 different test points (1%, 5%, 20%, 100% and 120%) each. The range of tested primary currents was from 10 mA to 60 kA. It can therefore be concluded that the results of each laboratory agree very well within the calculated measurement uncertainties. No outliers were observed. Considering especially the En factors, the calculated uncertainties seem to be too conservative to some extent. Here there is the possibility to slightly improve the uncertainty budgets in the future if there is a need. The worst En factors are within ±0.6 at 1 kA/5 A and ±0.8 at 3 kA. The current comparator 'IW 32' from PTB may have caused that. This was subsequently confirmed. The primary current induced a small voltage in the compensation winding. This problem has now been solved. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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SUPPLEMENTARY COMPARISON: EUROMET.L-S10 Comparison of squareness measurements
Mokros, Jiri
2005-01-01
from the weighted mean of data from participating laboratories, while some of them were excluded on the basis of statistical evaluation. Graphical interpretations of all deviations are contained in the Final Report. In order to compare the individual deviations mutually (25 profiles for the granite square and 44 profiles for the cylinder), graphical illustrations of 'standard deviations' and both extreme values (max. and min.) of deviations were created. This regional supplementary comparison has provided independent information about the metrological properties of the measuring equipment and method used by the participating NMIs. The Final Report does not contain the En values. Participants could not estimate some contributions in the uncertainty budget on the basis of previous comparisons, since no comparison of this kind had ever been organized. Therefore the En value cannot reflect the actual state of the given NMI. Instead of En, an analysis has been performed by means of the Grubbs test according to ISO 5725-2. This comparison provided information about the state of provision of metrological services in the field of big squares measurement. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EUROMET, according to the provisions of the Mutual Recognition Arrangement (MRA).
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The international comparison of radioactivity measurements on a solution of cesium-139
International Nuclear Information System (INIS)
Steyn, J.; Botha, S.M.; Van Staden, J.C.
1976-03-01
The participation by the NPRL in an intercomparison of radioactivity measurements as organised by the BIPM is fully described. The radioisotope involved, cesium 139, was made available to the BIPM by the NPRL in carrier-free form. The NPRL used the 4π gamma coincidence counting method with an internal liquid scintillation counter as 4π detector. The preliminary results released by the BIPM show the presence of relatively large systematic errors [af
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DC resistance comparison between a current comparator bridge and the quantum Hall system at Inmetro
International Nuclear Information System (INIS)
Da Silva, M C; Vasconcellos, R T B; Carvalho, H R
2016-01-01
This paper presents a comparison results between the Quantum Hall System (QHS) under development at the Quantum Electrical Metrology Laboratory (Lameq) and the current comparator calibration system, traceable to the Bureau International des Poids et Mesures (BIPM), at the Electrical Standardization Metrology Laboratory (Lampe), both part of the Electrical Metrology Division, at Inmetro. Comparisons were performed with 1 Ω, 10 Ω, 100 Ω, 1 kΩ and 10 kΩ resistors. The results obtained over two years of work are presented here, showing that the comparison contributed to improve the calibration systems of both Lampe and Lameq. (paper)
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Final report on APMP.M.H-S3: Comparison on hardness measurement Rockwell scale A and B
Sanponpute, Tassanai; Meesaplak, Apichaya; Menelao, Febo; Chan, T. K.; Bahng, Gun-Woong; Titus, S. S. K.; Jain, S. K.
2012-01-01
The APMP.M.H-S3 Rockwell hardness intercomparison was initiated by NIMT, Thailand and the required protocol was prepared by NIMT and checked by Dr John Man, MNIA, Australia, in 2009. PTB, Germany, Standards and Calibration Laboratory (SCL), Hong Kong, National Physical Laboratory (NPLI), India, and Korea Research Institute of Standards and Science (KRISS), Korea, participated in this comparison. This comparison exercise was focused on the measurement range of 25 to 100 HRBW scale and 35 to 85 HRA scale. The round robin test was done during the period from April 2010 to October 2010. The participating laboratories have demonstrated the capability of the machine and the operating conditions according to ISO 6508 Part 3 to perform the measurements. However, SCL, Hong Kong, could demonstrate their capability to perform the measurements only according to ISO 6508 Part 2. The CMCs declared by the different laboratories lie in the range of 0.30 HRA to 0.40 HRA and 0.40 HRBW to 0.75 HRBW. The CMC declared by SCL for the Rockwell B scale is 1.5 HRBW for the reason described above. It is observed from the results that the measurement uncertainty is estimated not less than the CMCs declared by the laboratories. From the measurement results provided by all the participating laboratories, the En ratio was determined to establish the degrees of equivalence. The En ratio was calculated by including as well as by excluding the results of the laboratory which has performed the test according to ISO 6508 Part 2 in order to make sure that it does not affect the overall results. It is noticed that the En ratio was still found to remain less than 1. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the APMP, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Final report on CCQM-K27.2: Second Subsequent study: determination of ethanol in aqueous media
Schantz, Michele M.; Parris, Reenie M.; May, Willie E.; Rosso, Adriana; Puglisi, Celia; Marques Rodrigues Caixeiro, Janaína; Massiff, Gabriela; Camacho Frías, Evangelina; Pérez Urquiza, Melina; Archer, Marcellé; Visser, M. S.; deVos, Betty-Jayne
2013-01-01
Ethanol is important both forensically ('drunk driving' or driving while under the influence, 'DWI', regulations) and commercially (alcoholic beverages). Blood- and breath-alcohol testing can be imposed on individuals operating private vehicles such as cars, boats or snowmobiles, or operators of commercial vehicles like trucks, planes and ships. The various levels of blood alcohol that determine whether these operators are considered legally impaired vary depending on the circumstances and locality. Accurate calibration and validation of instrumentation is critical in areas of forensic testing where quantitative analysis directly affects the outcome of criminal prosecutions, as is the case with the determination of ethanol in blood and breath. Additionally, the accurate assessment of the alcoholic content of beverages is a commercially important commodity. In 2002, the CCQM conducted a key comparison (CCQM-K27) for the determination of ethanol in aqueous matrix with nine participants. A report on this project has been approved by the CCQM and can be found at the BIPM website. CCQM-K27 comprised three samples, one at low mass fraction of ethanol in water (nominal concentration of 0.8 mg/g), one at high level (nominal concentration of 120 mg/g) and one wine matrix (nominal concentration of 81 mg/g). Overall agreement among eight participants using gas chromatography with flame ionization detection (GC-FID), titrimetry, isotope dilution gas chromatography/mass spectrometry (GC-IDMS) and gas chromatography-combustion-isotope ratio mass spectrometry (ID-GC-C-IRMS) was good. The ninth participant used a headspace GC-FID method that had not been validated in an earlier pilot study (CCQM-P35). A follow-on key comparison, CCQM-K27-Subsequent, was initiated in 2003 to accommodate laboratories that had not been ready to benchmark their methods in the original CCQM-K27 study or that wished to benchmark a different method. Four levels of ethanol in water were used in the
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International Nuclear Information System (INIS)
1980-01-01
Section I (Rayons X et γ, electrons) of the Comite Consultatif pour les Etalons de Mesure des Rayonnements Ionisants held its fifth meeting in May 1979. The members of the Section presented the work in progress in their respective laboratories; then they studied two documents describing the exposure measurements at BIPM and the conditions in which the comparisons are made. They also reviewed the exposure and absorbed dose comparisons performed at BIPM and elsewhere since 1977. New conditions of measurement were defined for the comparison of calorimeters in the BIPM 60 Co beam. Three working groups were set up to investigate the following problems: conversion from absorbed dose in graphite to absorbed dose in water, conversion from exposure to absorbed dose in water, and organization of an international comparison of Fricke chemical dosimeter systems. The growing importance of the radiation processing industry was stressed. Finally, the recent research work carried out at BIPM was presented and plans for the coming years were discussed. A recommendation was made concerning the study of calibrations in terms of absorbed dose in water [fr
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Popescu, Gheorghe
2001-06-01
An international frequency comparison was carried out at the Bundesamt fuer Eich- und Vermessungswessen (BEV), Vienna, within the framework of the EUROMET Project #498 from August 29 to September 5, 1999. The frequency differences obtained when the RO.1 laser from the National Institute for Laser, Plasma and Radiation Physics (NILPRP), Romania, was compared with five lasers from Austria (BEV1), Czech Republic (PLD1), France (BIPM3), Poland (GUM1) and Hungary (OMH1) are reported. Frequency differences were computed by using the matrix determinations for the group d, e, f, g. Considering the frequency differences measured for a group of three lasers compared to each other, we call the closing frequency the difference between measured and expected frequency difference (resulting from the previous two measurements). For the RO1 laser, when the BIPM3 laser was the reference laser, the closing frequencies range from +8.1 kHz to - 3.8 kHz. The relative Allan standard deviation was used to express the frequency stability and resulted 3.8 parts in 1012 for 100 s sampling time and 14000 s duration of the measurements. The averaged offset frequency relative to the BIPM4 stationary laser was 5.6 kHz and the standard deviation was 9.9 kHz.
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TWSTFT Data Treatment for UTC Time Transfer
2009-11-01
BUREAU INTERNATIONAL DES POIDS ET MESURES ORGANISATION INTERGOUVERNEMENTALE DE LA CONVENTION DU METRE...in [UTC-UTC(k)],” Metrologia , 43, 278-286. [4] BIPM Circular T 244, Section 6, May 2008, http://www.bipm.org [5] D. Piester, A. Bauch, L... Metrologia , 45, 185-198. [6] F. Arias, Z. Jiang, G. Petit, and W. Lewandowski, 2005, “BIPM Comparison of Time Transfer Techniques,” in Proceedings
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Table of Radionuclides (Vol. 7 - A = 14 to 245) - Monograph BIPM-5
International Nuclear Information System (INIS)
Arinc, Arzu; Be, Marie-Martine; Chiste, Vanessa; Mougeot, Xavier; Chechev, Valery P.; Galan, Monica; Huang, Xialong; Kondev, Filip G.; Luca, Aurelian; Nichols, Alan L.
2013-02-01
This monograph is one of several published in a series by the Bureau International des Poids et Mesures (BIPM) on behalf of the Consultative Committee for Ionizing Radiation (Comite Consultatif des Rayonnements Ionisants, CCRI). The aim of this series of publications is to review topics that are of importance for the measurement of ionizing radiation and especially of radioactivity, in particular those techniques normally used by participants in international comparisons. The purpose of this monograph, number 5 in the series, is to present the recommended values of nuclear and decay data for a wide range of radionuclides. Activity measurements for more than sixty-three of these radionuclides have already been the subject of comparisons under the auspices of Section II (dedicated to the Measurement of radionuclides) of the CCRI. The material for this monograph is now covered in seven volumes. The first two volumes contain the primary recommended data relating to half-lives, decay modes, x-rays, gamma-rays, electron emissions; alpha- and beta-particle transitions and emissions, and their uncertainties for a set of sixty-eight radionuclides, Volume 1 for those radionuclides with mass number up to and including 150 and Volume 2 for those radionuclides with mass number over 150. Volume 3 contains the equivalent data for twenty-six additional radionuclides as listed and re-evaluations for 125 Sb and 153 Sm. Volume 4 contains the data for a further thirty-one radionuclides with a re-evaluation for 226 Ra and Volume 5 includes seventeen new radionuclide evaluations and eight re-evaluations of previous data as identified in the contents page. Volume 6 contains twenty-one new radionuclide evaluations and four re-evaluations, for 64 Cu, 236 Np, 37 Np and 239 U. The present Volume 7 contains twenty-four new radionuclide evaluations and five re-evaluations, for 67 Ga, 208 Tl, 228 Th, 242 Cm and 244 Cm. The data have been collated and evaluated by an international working group
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Final report of APMP.QM-S6: clenbuterol in porcine meat
Sin, D. W.-M.; Ho, C.; Yip, Y.-C.
2016-01-01
At the CCQM Organic Analysis Working Group (OAWG) Meeting held in April 2012 and the APMP TCQM Meeting held in November 2012, an APMP supplementary comparison (APMP.QM-S6) on the determination of clenbuterol in porcine meat was supported by the OAWG and APMP TCQM. This comparison was organized by the Government Laboratory, Hong Kong. In order to accommodate a wider participation, a pilot study (APMP.QM-P22) was run in parallel to APMP.QM-S6. This study provided the means for assessing the measurement capabilities for determination of low-polarity measurands in a procedure that requires extraction, clean-up, analytical separation, and selective detection in a food matrix. A total of 7 institutes registered for the supplementary comparison and 6 of them submitted their results. 4 results were included for SCRV calculation. All participating laboratories applied Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry (ID-LCMS/MS) technique with clenbuterol-d9 as internal standard spiked for quantitation in this programme. KEY WORDS FOR SEARCH APMP.QM-S6 and Clenbuterol Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Nuclear Information System (INIS)
Tauhata, Luiz; Elizabeth Couto Machado Vianna, Maria; Eduardo de Oliveira, Antonio; Cristina de Melo Ferreira, Ana; Julia Camara da Silva Braganca, Maura; Faria Clain, Almir
2006-01-01
To show the influence of measurement uncertainties in performance evaluation of laboratories, data from 42 comparison runs were evaluated using two statistical criteria. The normalized standard deviation, D, used by US EPA, that mainly takes into account the accuracy, and the normalized deviation, E, that includes the individual laboratory uncertainty used for performance evaluation in the key-comparisons by BIPM. The results show that data evaluated by the different criteria give a significant deviation of laboratory performance in each radionuclide assay when we analyse a large quantity of data
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EURAMET.T-K7 Key Comparison of Water Triple-Point Cells
Peruzzi, A.; Bosma, R.; Kerkhof, O.; Rosenkranz, P.; Del Campo Maldonado, M. D.; Strnad, R.; Nielsen, J.; Anagnostou, M.; Veliki, T.; Zvizdic, D.; Grudnewicz, E.; Nedea, M.; Neagu, D. M.; Steur, P.; Filipe, E.; Lobo, I.; Antonsen, I.; Renaot, E.; Heinonen, M.; Weckstrom, T.; Bojkovski, J.; Turzo-Andras, E.; Nemeth, S.; White, M.; Tegeler, E.; Dobre, M.; Duris, S.; Kartal Dogan, A.; Uytun, A.; Augevicius, V.; Pauzha, A.; Pokhodun, A.; Simic, S.
2011-12-01
The results of a EURAMET key comparison of water triple-point cells (EURAMET.T-K7) are reported. The equipment used, the measuring conditions applied, and the procedures adopted for the water triple-point measurement at the participating laboratories are synthetically presented. The definitions of the national reference for the water triple-point temperature adopted by each laboratory are disclosed. The multiplicity of degrees of equivalence arising for the linking laboratories with respect to the "mother" comparison CCT-K7 is discussed in detail.
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Standardization of a 89Sr solution from a BIPM intercomparison using a liquid scintillation method
International Nuclear Information System (INIS)
Cruz, P.A.L.; Loureiro, J.S.; Bernardes, E.M.O.
2002-01-01
A procedure to standardize 89 Sr (as strontium chloride) solutions, within the frame of a BIPM intercomparison, by the CIEMAT/NIST method was presented for Instagel Plus, HiSafe III and Ultima Gold liquid scintillation cocktails. The stability was studied for two types of samples: those obtained by direct addition of the 89 Sr solution and those by the extra addition of 0.5 ml of HCl (0.1 mol l -1 ) to the cocktails. The results only showed good stability with the three scintillants used when additional HCl was added to the cocktails. The activities per unit mass determined for 89 Sr were: 26.344 kBq g -1 for Instagel Plus; 26.335 kBq g -1 for HiSafe III; and 26.310 kBq g -1 for Ultima Gold (at a reference time of 2000.10.01, 00 h UT) with a total uncertainty of 0.5% in each case (k=1)
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KEY COMPARISON: Report on the Regional Comparison COOMET.AUV.A-K3
Barrera-Figueroa, Salvador; Nielsen, Lars; Rasmussen, Knud
2007-01-01
COOMET.AUV.A-K3 is a Regional Comparison that supplements the Key Comparison CCAUV.A-K3 organized by the CCAUV. The participating NMIs are GUM (Poland), INM (Romania), VNIIFTRI (Russia) and DP-NDI 'Systema' (Ukraine). The role of Pilot laboratory was undertaken by DPLADFM (Denmark). The measurements took place between May 2005 and February 2006. The time schedule was organized in a single star configuration. Initially, two LS2aP microphones were circulated. However, a sudden change of sensitivity of one of them forced the inclusion of an additional microphone. Nevertheless, the analysis was performed on all microphones involved. This report includes the measurement results from the participants, information about their calibration methods, and the analysis leading to the assignation of degrees of equivalence and the link to the CCAUV.A-K3. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCAUV, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
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International Nuclear Information System (INIS)
Csete, I.; Leiton, A.G.; Sochor, V.; Lapenas, A.; Grindborg, J.E.; Jokelainen, I.; Bjerke, H.; Dobrovodsky, J.; Megzifene, A.; Hourdakis, C.J.; Ivanov, R.; Vekic, B.; Kokocinski, J.; Cardoso, J.; Buermann, L.; Tiefenboeck, W.; Stucki, G.; Van Dijk, E.; Toni, M.P.; Minniti, R.; McCaffrey, J.P.; Silva, C.N.M.; Kharitonov, I.; Webb, D.; Saravi, M.; Delaunay, F.
2010-01-01
The results of an unprecedented international effort involving 26 countries are reported. The EUROMET.RI(I)-K1 and EUROMET.RI(I)-K4 key comparisons were conducted with the goal of supporting the relevant calibration and measurement capabilities (CMC) planned for publication by the participant laboratories. The measured quantities were the air kerma (K air ) and the absorbed dose to water (Dw) in 60 Co radiotherapy beams. The comparison was conducted by the pilot laboratory MKEH (Hungary), in a star-shaped arrangement from January 2005 to December 2008. The calibration coefficients of four transfer ionization chambers were measured using two electrometers. The largest deviation between any two calibration coefficients for the four chambers in terms of air kerma and absorbed dose to water was 2.7% and 3.3% respectively. An analysis of the participant uncertainty budgets enabled the calculation of degrees of equivalence (DoE), in terms of the deviations of the results and their associated uncertainties. As a result of this EUROMET project 813 comparison, the BIPM key comparison database (KCDB) will include eleven new Kair and fourteen new D w DoE values of European secondary standard dosimetry laboratories (SSDLs), and the KCDB will be updated with the new DoE values of the other participant laboratories. The pair-wise degrees of equivalence of participants were also calculated. In addition to assessing calibration techniques and uncertainty calculations of the participants, these comparisons enabled the experimental determinations of N Dw /N Kair ratios in the 60 Co gamma radiation beam for the four radiotherapy transfer chambers. (authors)
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DEFF Research Database (Denmark)
Cutanda Henríquez, Vicente; Rasmussen, Knud; Nielsen, Lars
2006-01-01
The CCAUV.A-K3 Key Comparison has involved 15 countries organized in two loops with two common laboratories, CENAM and DPLA. The measurements took place in 2003. This is the first CCAUV key comparison organized with more than one loop, and therefore the analysis of the results required a more ela...
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Consensus building for interlaboratory studies, key comparisons, and meta-analysis
Koepke, Amanda; Lafarge, Thomas; Possolo, Antonio; Toman, Blaza
2017-06-01
Interlaboratory studies in measurement science, including key comparisons, and meta-analyses in several fields, including medicine, serve to intercompare measurement results obtained independently, and typically produce a consensus value for the common measurand that blends the values measured by the participants. Since interlaboratory studies and meta-analyses reveal and quantify differences between measured values, regardless of the underlying causes for such differences, they also provide so-called ‘top-down’ evaluations of measurement uncertainty. Measured values are often substantially over-dispersed by comparison with their individual, stated uncertainties, thus suggesting the existence of yet unrecognized sources of uncertainty (dark uncertainty). We contrast two different approaches to take dark uncertainty into account both in the computation of consensus values and in the evaluation of the associated uncertainty, which have traditionally been preferred by different scientific communities. One inflates the stated uncertainties by a multiplicative factor. The other adds laboratory-specific ‘effects’ to the value of the measurand. After distinguishing what we call recipe-based and model-based approaches to data reductions in interlaboratory studies, we state six guiding principles that should inform such reductions. These principles favor model-based approaches that expose and facilitate the critical assessment of validating assumptions, and give preeminence to substantive criteria to determine which measurement results to include, and which to exclude, as opposed to purely statistical considerations, and also how to weigh them. Following an overview of maximum likelihood methods, three general purpose procedures for data reduction are described in detail, including explanations of how the consensus value and degrees of equivalence are computed, and the associated uncertainty evaluated: the DerSimonian-Laird procedure; a hierarchical Bayesian
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Daly, P.; Koshelyaevsky, N. B.; Lewandowski, Wlodzimierz; Petit, Gerard; Thomas, Claudine
1992-01-01
The University of Leeds built a Global Positioning System/Global Orbiting Navigation Satellite System (GPS/GLONASS) receiver about five years ago and since then has provided continuous information about GLONASS time and its comparison with GPS time. For the last two years, VNIIFTRI (All Union Institute for Physical, Technical and Radiotechnical Measurements) and some other Soviet time laboratories have used Soviet built GLONASS navigation receivers for time comparisons. Since June 1991, VNIIFTIR has been operating a GPS time receiver on loan from the BIPM (Bureau International des Poids et Mesures). This offered, for the first time, an opportunity for direct comparison of time transfers using GPS and GLONASS. This experiment shows that even with relatively imprecise data recording and processing, in terms of time metrology, GLONASS can provide continental time transfer at a level of several tens of nanoseconds.
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CCQM K6.2 determination of total cholesterol in human serum
Wise, Stephen A.; Phinney, Karen W.; Duewer, David L.; Sniegoski, Lorna T.; Welch, Michael J.; Pabello, Guiomar; Avila Caldero, Marco A.; Qinde, Liu; Kooi, Lee Tong; Rego, Eliane; Garrido, Bruno; Allegri, Gabriella; de La Cruz, Marcia; Barrabin, Juliana; Puglisi, Celia; Lopez, Eduardo; Lee, Hwashim; Kim, Byungjoo; Delatour, Vincent; Heuillet, Maud; Nammoonnoy, Jintana; Ceyhan Gören, Ahmet; Bilsel, Gokhan; Konopelko, L.; Krylov, A.; Lopushanskaya, E.
2018-01-01
in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Directory of Open Access Journals (Sweden)
Pryo Utomo
2017-06-01
Full Text Available One Time Pad (OTP is a cryptographic algorithm that is quite easy to be implemented. This algorithm works by converting plaintext and key into decimal then converting into binary number and calculating Exclusive-OR logic. In this paper, the authors try to make the comparison of OTP cryptography using KPI and KCT so that the ciphertext will be generated more difficult to be known. In the Key and Plaintext Insertion (KPI Method, we modify the OTP algorithm by adding the key insertion in the plaintext that has been splitted. Meanwhile in the Key Coloumnar Transposition (KCT Method, we modify the OTP algorithm by dividing the key into some parts in matrix of rows and coloumns. Implementation of the algorithms using PHP programming language.
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Elements in human serum—CCQM-K139
Shin, Richard; Dewi, Fransiska; Tong, Benny; Wah, Leung Ho; Saxby, David; Armishaw, Paul; Ivanova, Veronika; Feng, Liuxing; Wang, Jun; Estela del Castillo Busto, M.; Fisicaro, Paola; Rienitz, Olaf; Fung, Wai-Hong; Ho-pan Yau, Michael; Yim, Yong-Hyeon; Buzoianu, Mirella; Can, Suleyman Z.; Ari, Betul; Cankur, Oktay; Goenaga Infante, Heidi; Pérez-Zambra, Ramiro; Ferreira, Elizabeth; Long, Stephen
2018-01-01
Elements in human serum serve as important biomarkers and their levels reflect the well-being of an individual. Electrolytes such as sodium (Na) and chloride (Cl) are crucial in maintaining the normal distribution of water, osmotic pressure and electrical neutrality in the body. Trace element such as copper (Cu) plays a part in many oxidation-reduction reactions and metalloenzymes. The majority of selenium (Se) exists as selenoproteins which are cofactors in the glutathione peroxidase activity that protects the body against free radicals. Phosphorus (P) is required for strong bones and teeth. It is also indispensable for growth, maintenance and repair of tissues and cells. The key comparison CCQM-K139: elements in human serum was coordinated by the Health Sciences Authority, Singapore. This comparison aimed to enable participating National Metrology Institutes (NMIs) and Designated Institutes (DIs) to demonstrate their competence in the determination of elements (electrolytes and essential elements) in human serum. The five measurands (Na, Cl, Cu, Se and P) selected for this comparison were not covered in the last two comparisons in the clinical area (CCQM-K14 and CCQM-K107) and offered different analytical challenges. Their concentration levels were within the normal biological range. They were also within the range of existing calibration and measurement capability (CMC) claims in the International Bureau of Weights and Measures' Key Comparison Database (BIPM KCDB). Ten institutes participated in the comparison for Na, eight for Cl, eleven for Cu, six for Se and eight for P. For the analysis of Na, Cu, Se and P, most of the participating institutes employed microwave-assisted digestion and acid digestion (with or without heating) sample dissolution. For the analysis of Cl, in addition to the microwave-assisted digestion and acid digestion, a wider variety of techniques were employed. These included matrix separation, alkaline extraction and coulometric titration
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1993-06-01
additional source. For the past three years VNIIFTRI (Mendeleevo, Moscow Region, Russian Federation) and some other Russian time laboratories have used...Russian-built GLONASS navigation receivers for time 47 comparisons. Since June 1991, VNIIFTRI has operated a commercial CPS time receiver on loan from...the BIPM. Since February 1992, the BIPM has operated Russian GLONASS receiver on loan from the VNIIFTRI . This provides, for the first time, an
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International comparison of activity measurements of a solution of 75Se
Ratel, Guy
2002-04-01
Activity measurements of a solution of 75Se, supplied by the BIPM, have been carried out by 21 laboratories within the framework of an international comparison. Seven different methods were used. Details on source preparation, experimental facilities and counting data are reported. The measured activity-concentration values show a total spread of 6.62% before correction and 6.02% after correction for delayed events, with standard deviations of the unweighted means of 0.45% and 0.36%, respectively. The correction for delayed events was measured directly by four laboratories. Unfortunately no consensus on the activity value could be deduced from their results. The results of the comparison have been entered in the tables of the International Reference System (SIR) for γ-ray emitting radionuclides. The half-life of the metastable state was also determined by two laboratories and found to be in good agreement with the values found in the literature.
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Radionuclide metrology: traceability and response to a radiological accident
Energy Technology Data Exchange (ETDEWEB)
Tauhata, L.; Cruz, P.A.L. da; Silva, C.J. da; Delgado, J.U.; Oliveira, A.E. de; Oliveira, E.M. de; Poledna, R.; Loureiro, J. dos S.; Ferreira Filho, A.L.; Silva, R.L. da; Filho, O. L.T.; Santos, A.R.L. dos; Veras, E.V. de; Rangel, J. de A.; Quadros, A.L.L.; Araújo, M.T.F. de; Souza, P.S. de; Ruzzarim, A.; Conceição, D.A. da; Iwahara, A., E-mail: palcruz@ird.gov.br [Instituto de Radioproteção e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiações Ionizantes
2017-07-01
In the case of a radiological accident, there are characteristic phases: discovery and initial assistance with first aid; the triage and monitoring of the affected population; the release of the affected people; forward the victims to medical care; as well as the preparation of the report on the accident. In addition, studies and associated researches performed in the later period. Monitors, dosimeters and measuring systems should be calibrated by contaminating radionuclide standards. The radioactive sources used must be metrologically reliable. In Brazil, this function is performed by LNMRI/IRD/CNEN, designated by INMETRO, which Radionuclide Metrology Laboratory is responsible for the standardization and supply of radioactive sources in diverse geometries and matrices. This laboratory has a stock of radionuclide solutions with controlled environmental variables for the preparation of sources, which are calibrated and standardized by mean of primary and secondary systems. It is also responsible for the dissemination of standards and, in order to establish the metrological traceability of national standards, participates in international key-comparisons promoted by BIPM and regional metrology organizations. Internally, it promotes the National Comparison Programs for laboratories for the analysis of environmental samples and the traceability for producing centers of radiopharmaceuticals and Nuclear Medicine Services in the country. The paper presents the demand for {sup 137}Cs related to the radioactive accident in Goiania/Brazil and the significant results for the main radionuclides standardized by the Radionuclide Metrology Laboratory for international key-comparisons and national comparisons to provide metrological traceability. With the obtained results, the LNMRI of Brazil integrates the international metrology BIPM network and fulfills its function of supplying, with about a hundred of radioactive standards, the country's needs in different applications
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Radionuclide metrology: traceability and response to a radiological accident
International Nuclear Information System (INIS)
Tauhata, L.; Cruz, P.A.L. da; Silva, C.J. da; Delgado, J.U.; Oliveira, A.E. de; Oliveira, E.M. de; Poledna, R.; Loureiro, J. dos S.; Ferreira Filho, A.L.; Silva, R.L. da; Filho, O. L.T.; Santos, A.R.L. dos; Veras, E.V. de; Rangel, J. de A.; Quadros, A.L.L.; Araújo, M.T.F. de; Souza, P.S. de; Ruzzarim, A.; Conceição, D.A. da; Iwahara, A.
2017-01-01
In the case of a radiological accident, there are characteristic phases: discovery and initial assistance with first aid; the triage and monitoring of the affected population; the release of the affected people; forward the victims to medical care; as well as the preparation of the report on the accident. In addition, studies and associated researches performed in the later period. Monitors, dosimeters and measuring systems should be calibrated by contaminating radionuclide standards. The radioactive sources used must be metrologically reliable. In Brazil, this function is performed by LNMRI/IRD/CNEN, designated by INMETRO, which Radionuclide Metrology Laboratory is responsible for the standardization and supply of radioactive sources in diverse geometries and matrices. This laboratory has a stock of radionuclide solutions with controlled environmental variables for the preparation of sources, which are calibrated and standardized by mean of primary and secondary systems. It is also responsible for the dissemination of standards and, in order to establish the metrological traceability of national standards, participates in international key-comparisons promoted by BIPM and regional metrology organizations. Internally, it promotes the National Comparison Programs for laboratories for the analysis of environmental samples and the traceability for producing centers of radiopharmaceuticals and Nuclear Medicine Services in the country. The paper presents the demand for 137 Cs related to the radioactive accident in Goiania/Brazil and the significant results for the main radionuclides standardized by the Radionuclide Metrology Laboratory for international key-comparisons and national comparisons to provide metrological traceability. With the obtained results, the LNMRI of Brazil integrates the international metrology BIPM network and fulfills its function of supplying, with about a hundred of radioactive standards, the country's needs in different applications
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Energy Technology Data Exchange (ETDEWEB)
Csete, I. [National Office of Measures (OMH) - pilot laboratory and corresponding author (Hungary); Leiton, A.G. [Research Centre for Energy, Environment and Technology (CMRI-CIEMAT) (Spain); Sochor, V. [Czech Metrology Institute (CMI) (Czech Republic); Lapenas, A. [Latvian National Metrology Center (LNMC-RMTC) (Latvia); Grindborg, J.E. [Swedish Radiation Protection Authority (SSI) (Sweden); Jokelainen, I. [Radiation and Nuclear Safety Authority (STUK) (Finland); Bjerke, H. [Norwegian Radiation Protection Authority (NRPA) (Norway); Dobrovodsky, J. [Slovak Institute of Metrology (SMU) (Slovakia); Megzifene, A. [International Atomic Energy Agency, IAEA, Vienna (Austria); Hourdakis, C.J. [Hellenic Atomic Energy Committee (HAEC-HIRCL) (Greece); Ivanov, R. [National Centre of Metrology (NCM) (Bulgaria); Vekic, B. [Rudjer Boskovic Institute (IRB) (Croatia); Kokocinski, J. [Central Office of Measures (GUM) (Poland); Cardoso, J. [Institute for Nuclear Technology (ITN-LMRIR) (Portugal); Buermann, L. [Physikalisch Technische Bundesanstalt (PTB) (Germany); Tiefenboeck, W. [Bundesamt fur Eich und Vermesungswesen (BEV) (Austria); Stucki, G. [17 Bundesamt fur Metrologie (METAS) (Switzerland); Van Dijk, E. [NMi Van Swinden Laboratorium (NMi) (Netherlands); Toni, M.P. [ENEA-CR Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (ENEA) (Italy); Minniti, R. [20 National Institute of Standards and Technology (NIST) (United States); McCaffrey, J.P. [National Research Council Canada (NRC) (Canada); Silva, C.N.M. [National Metrology Laboratory of Ionizing Radiation (LNMRI-IRD) (Brazil); Kharitonov, I. [D I Mendeleyev Institute for Metrology (VNIIM) (RU); Webb, D. [Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) (Australia); Saravi, M. [National Atomic Energy Commission (CNEA-CAE) (Argentina); Delaunay, F. [Laboratoire National Henri Becquerel (LNE-LNHB) (France)
2010-06-15
The results of an unprecedented international effort involving 26 countries are reported. The EUROMET.RI(I)-K1 and EUROMET.RI(I)-K4 key comparisons were conducted with the goal of supporting the relevant calibration and measurement capabilities (CMC) planned for publication by the participant laboratories. The measured quantities were the air kerma (K{sub air}) and the absorbed dose to water (Dw) in {sup 60}Co radiotherapy beams. The comparison was conducted by the pilot laboratory MKEH (Hungary), in a star-shaped arrangement from January 2005 to December 2008. The calibration coefficients of four transfer ionization chambers were measured using two electrometers. The largest deviation between any two calibration coefficients for the four chambers in terms of air kerma and absorbed dose to water was 2.7% and 3.3% respectively. An analysis of the participant uncertainty budgets enabled the calculation of degrees of equivalence (DoE), in terms of the deviations of the results and their associated uncertainties. As a result of this EUROMET project 813 comparison, the BIPM key comparison database (KCDB) will include eleven new Kair and fourteen new D{sub w} DoE values of European secondary standard dosimetry laboratories (SSDLs), and the KCDB will be updated with the new DoE values of the other participant laboratories. The pair-wise degrees of equivalence of participants were also calculated. In addition to assessing calibration techniques and uncertainty calculations of the participants, these comparisons enabled the experimental determinations of N{sub Dw}/N{sub Kair} ratios in the {sup 60}Co gamma radiation beam for the four radiotherapy transfer chambers. (authors)
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Hein, Sebastian; Philipp, Rosemarie; Duewer, David L.; Gasca Aragon, Hugo; Lippa, Katrice A.; Toman, Blaza
2013-01-01
-weighted generalized distance regression was used to establish the key comparison reference function (KCRF) relating the assigned values to the repeatability measurements. On the basis of leave-one-out cross-validation, all of the assigned values for all 27 materials were deemed equivalent at the 95% level of confidence. These materials were used to define the KCRF. Parametric bootstrap Monte Carlo was used to estimate 95% level-of-confidence coverage intervals for the degrees of equivalence of materials, d +/- U95(d), and of the participating NMIs, D +/- U95(D). Because of the very wide range of ethanol mass fraction in the materials, these degrees of equivalence are expressed in percent relative form: %d +/- U95(%d) and %D +/- U95(%D). The median of the absolute values of the %D for the participating NMIs is less than 0.05% with a median U95(%D) of less than 1%. These results demonstrate that the participating NMIs have the ability to correctly value-assign CRMs and proficiency test materials for ethanol in aqueous media and similar measurands. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Nuclear Information System (INIS)
McEwen, Malcolm; Sharpe, Peter; Voros, Sandor
2015-01-01
When comparing absorbed dose standards from different laboratories (e.g. National Measurement Institutes, NMIs, for Key or Supplementary comparisons) it is rarely possible to carry out a direct comparison of primary standard instruments, and therefore some form of transfer detector is required. Historically, air-filled, unsealed ionization chambers have been used because of the long history of using these instruments, very good stability over many years, and ease of transport. However, the use of ion chambers for therapy-level comparisons is not without its problems. Findings from recent investigations suggest that ion chambers are prone to non-random variations, they are not completely robust to standard courier practices, and failure at any step in a comparison can render all measurements potentially useless. An alternative approach is to identify a transfer system that is insensitive to some of these concerns - effectively a dosimeter that is inexpensive, simple to use, robust, but with sufficient precision and of a size relevant to the disseminated quantity in question. The alanine dosimetry system has been successfully used in a number of situations as an audit dosimeter and therefore the purpose of this investigation was to determine whether alanine could also be used as the transfer detector for dosimetric comparisons, which require a lower value for the measurement uncertainty. A measurement protocol was developed for comparing primary standards of absorbed dose to water in high-energy electron beams using alanine pellets irradiated in a water-equivalent plastic phantom. A trial comparison has been carried out between three NMIs and has indicated that alanine is a suitable alternative to ion chambers, with the system used achieving a precision of 0.1%. Although the focus of the evaluation was on the performance of the dosimeter, the comparison results are encouraging, showing agreement at the level of the combined uncertainties (∼0.6%). Based on this
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International Nuclear Information System (INIS)
Simpson, B.R.S.; Meyer, B.R.
1989-01-01
The Bureau International des Poids et Mesures (BIPM) organized an international comparison of activity measurements of a solution of 125 I. The half-life value adopted was 59.5±0.4d. The large uncertainty took account of a recently published value (Schrader, 1986) which is considerably lower than the widely used value of 60.0±0.1d. The present work, which was undertaken at the suggestion of the BIPM, has yielded a value which confirms the lower measurement. (author)
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Directory of Open Access Journals (Sweden)
Ofelia Robatto
2011-05-01
Full Text Available El Laboratorio Tecnológico del Uruguay, LATU, es el Instituto Metrológico Nacional del Uruguay, miembro fi rmante del Acuerdo de Reconocimiento Mutuo (MRA entre Laboratorios Nacionales de Metrología del Comité Internacional de Pesas y Medidas (CIPM. Las capacidades de medida y calibración (CMCs del LATU fueron reconocidas en junio de 2004 y se encuentran publicadas en la BIPM- Key Comparison Data Base (BIPM, 2009. El LATU estuvo acreditado desde 2001 hasta junio de 2007 por el Deutscher Kalibrier Dienst (Servicio de Acreditación Alemán en las magnitudes Masa, Balanzas y Temperatura (Laboratorio DKD, DKD-K-25601. Se decidió a partir de ese momento probar el cumplimiento con los criterios establecidos por el CIPM MRA y los requisitos de la Norma ISO/IEC 17025 en el marco de una auditoría in situ llevada a cabo en el LATU en enero de 2008. Como parte de ese proceso de revisión de pares, se realizó una Intercomparación Bilateral entre el PTB y el LATU en los puntos fi jos de la Escala Internacional de Temperatura (ITS-90, desde el punto triple de Hg hasta el punto de congelación del Zn, con el PTB como laboratorio piloto. En este artículo los resultados son presentados y discutidos de manera de sostener ladeclaración de mejores capacidades de medida y calibración (CMCs en sustitución de las ya declaradas.AbstractLaboratorio Tecnológico del Uruguay, LATU, is the National Metrology Institute of Uruguay, signatory of the CIPM Mutual Recognition Arrangement (CIPM MRA, has Calibration and Measurement Capabilities (CMCs in temperature that were fi rst published in the BIPM Key Comparison Data Base (BIPM, 2009 in June 2004. LATU was a DKD Laboratory accredited in Mass, Balances and Temperature from 2001 until June 2007 when it was decided to adopt the CIPM criteria for proving compliance with ISO/IEC 17025 through a Peer Review process. The LATU on site Peer Review was carried out in January 2008, as part of the process. During the
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KEY COMPARISON: Final report of EUROMET Project 696: pH determination of a phthalate buffer
Spitzer, Petra; Charlet, Philippe; Eberhard, Ralf; Karpov, Oleg V.; Philippe, Rachel; Rivier, Cedric; Maximov, Igor; Sudmeier, Uwe
2005-01-01
The EUROMET project 696, a trilateral comparison between PTB, Germany, LNE, France and VNIIFTRI, Russia was performed in order to demonstrate and document the capability of the participants to measure the pH of a phthalate buffer by the primary measurement procedure for pH. Good agreement of the reported results was observed. The sample was very similar to the one used in the comparison CCQM-K17. PTB acts as pilot laboratory in CCQM-K17 and in EUROMET 696. This comparison allows one to link the results obtained by LNE to the CCQM-K17 key comparison through the degree of equivalence of PTB. On the other hand, the discrepancy between measured pH values at the VNIIFTRI and PTB for the same type of buffer solution decreased, as compared with a bilateral comparison in 1997. Main text. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the Mutual Recognition Arrangement (MRA).
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International Nuclear Information System (INIS)
1982-01-01
Section II (Mesure des radionucleides) of the Comite Consultatif pour les Etalons de Mesure des Rayonnements Ionisants held its sixth meeting in May 1981. The results of an international comparison of 55 Fe, organized by the National Physical Laboratory, and of a trial comparison of 133 Ba were discussed. A full-scale comparison of 137 Cs activity measurements and a repetition of the 133 Ba trial comparison are to take place within the next two years. A trial comparison of 109 Cd is also proposed. Recent work in radioactivity carried out at BIPM was reported. The usefulness of the international reference system for measuring the activity of gamma-ray emitters was generally acknowledged. The new ''selective sampling'' method which avoids measuring coincidences attracted much attention. The Working Party reports and a new monograph (BIPM-3) were presented. Finally, there was a broad exchange of information on work in progress at the various laboratories represented at the meeting [fr
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Wise, Stephen A.; Phinney, Karen W.; Duewer, David L.; Sniegoski, Lorna T.; Welch, Michael J.; Pritchett, Jeanita; Pabello, Guiomar; Avila Calderon, Marco A.; Balderas, Miryan; Qinde, Liu; Kooi, Lee Tong; Rego, Eliane; Garrido, Bruno; Allegri, Gabriella; de La Cruz, Marcia; Barrabin, Juliana; Monteiro, Tânia; Lee, Hwashim; Kim, Byungjoo; Delatour, Vincent; Peignaux, Maryline; Kawaguchi, Migaku; Bei, Xu; Can, Quan; Nammoonnoy, Jintana; Schild, Katrin; Ohlendorf, Rüdiger; Henrion, Andre; Ceyhan Gören, Ahmet; Yılmaz, Hasibe; Bilsel, Mine; Konopelko, L.; Krylov, A.; Lopushanskaya, E.
2018-01-01
biological matrices include sample preparation (protein precipitation, extraction, derivatization), gas chromatographic (GC) or liquid chromatographic (LC) separation, and quantification using an isotope dilution mass spectrometry (IDMS) approach. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Standardization of Pure Beta Emitters
International Nuclear Information System (INIS)
Los Arcos, Jose Maria; Rodriguez, Leonor
2006-01-01
The paper describes the traditional methods of standardization of Pure Beta Emitters, their principal characteristics, advantage and drawbacks. It does comparisons between two metrological LSC methods: Triple to double coincidence ratio (TDCR) method and the CIEMAT/NIST method and presents the result obtained with several Key Comparisons serving as practical test of both methods. Both of them represent the siferrit of methods of standardization of pure (and mixed decay) radionuclides. ESIR WG of CCRI(II) is to implement a reference exchange system for the permanent equivalence of β, α and electron capture nuclides, similar to traditional SIR gamma. ESIR project is currently testing a new XAN scintillator and operational tests of the whole system at BIPM are expected by the end of 2006 (test restricted to ESIR NMI members)
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Stock, Michael; Barat, Pauline; Davis, Richard S.; Picard, Alain; Milton, Martin J. T.
2015-04-01
This report presents the results of the first phase of the campaign of calibration carried out with respect to the international prototype of the kilogram (IPK) in anticipation of the redefinition of the kilogram (Extraordinary Calibrations). The definition of the kilogram was realized according to the procedure outlined in the 8th Edition of the SI Brochure. Thus the IPK and its six official copies have been cleaned and washed following the BIPM procedure. The mass comparisons carried out during this campaign showed a very good repeatability. The pooled standard deviation of repeated weighings of the prototypes was 0.4 µg. The effect of cleaning and washing of the IPK was to remove a mass of 16.8 µg. The effect of cleaning and washing of the six official copies was found to be very similar, giving an average mass removed from the seven prototypes of 15 µg with a standard deviation of 2 µg. The differences in mass between the IPK and the official copies have changed by an average of 1 µg since the 3rd Periodic Verification of National Prototypes of the Kilogram (1988-1992). These results do not confirm the trend for the masses of the six official copies to diverge from the mass of the IPK that was observed during the 2nd and 3rd Periodic Verifications. All BIPM working standards and the prototypes reserved for special use have been calibrated with respect to the IPK as part of this campaign. All of them were found to have lower masses than when they were calibrated during the 3rd Periodic Verification. As a consequence, the BIPM ‘as-maintained’ mass unit in 2014 has been found to be offset by 35 µg with respect to the IPK. This result will be analyzed in a further publication.
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Camara, Johanna E.; Duewer, David L.; Gasca Aragon, Hugo; Lippa, Katrice A.; Toman, Blaza
2013-01-01
regression was used to establish the key comparison reference function (KCRF) relating the assigned values to the repeatability measurements. Parametric bootstrap Monte Carlo was used to estimate 95% level-of-confidence coverage intervals for the degrees of equivalence of materials, d +/- U95(d), and of the participating NMIs, D +/- U95(D). Because of the wide range of creatinine mass fraction in the materials, these degrees of equivalence are expressed in percent relative form: %d +/- U95(%d) and %D +/- U95(%D). On the basis of leave-one-out cross-validation, the assigned values for 16 of the 17 materials were deemed equivalent at the 95% level of confidence. These materials were used to define the KCRF. The excluded material was identified as having a marginally underestimated assigned uncertainty, giving it large and potentially anomalous influence on the KCRF. However, this material's %d of 1.4 +/- 1.5 indicates that it is equivalent with the other materials at the 95% level of confidence. The median |%d| for all 17 of the materials is 0.3 with a median U95(%d) of 1.9. All of these higher-order CRMs for creatinine in human serum are equivalent within their assigned uncertainties. The median |%D| for the participating NMIs is 0.3 with a median U95(%D) of 2.1. These results demonstrate that all participating NMIs have the ability to correctly value-assign CRMs and proficiency test materials for creatinine in human serum and similar measurands. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Inter-RMO Key Comparison EUROMET.L-K5.2004: Calibration of a step gauge
DEFF Research Database (Denmark)
Prieto, Emilio; Brown, Nicholas; Lassila, Antti
2012-01-01
The results of the inter-RMO key comparison EUROMET.L-K5.2004 on the calibration of a step gauge are reported. Eighteen National Metrology Institutes and one Designated Institute from four different metrological regions all over the world participated in this comparison which lasted three years...... value. Due to the significant instability of the step it was also considered an artefact uncertainty. The reported uncertainties ranged from 0.045 µm to 1.2 µm (k = 1). The uncertainty of the artefact ranged from 0.018 µm (for the 20 mm face) to 0.176 µm (for the 400 mm face). The compatibility of all...... participants for measuring step gauges was demonstrated with the only exception of a participant showing very high systematic (both positive and negative) errors. Five participants communicated higher uncertainties than the corresponding approved CMCs. A set of Recommendations and Actions were agreed therefore...
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Contaminant and other elements in soil (CCQM-K127)
Rocio Arvizu Torres, M.; Manzano, J. Velina Lara; Valle Moya, Edith; Horvat, Milena; Jaćimović, Radojko; Zuliani, Tea; Vreča, Polona; Acosta, Osvaldo; Bennet, John; Snell, James; Almeida, Marcelo D.; de Sena, Rodrigo C.; Dutra, Emily S.; Yang, Lu; Li, Haifeng
2017-01-01
by their available analytical methods. This facilitated the investigation into the core capabilities of participants to measure the mass fraction of tested elements in soil and therefore to claim their CMCs as listed in appendix C of the key comparison database (KCDB) under the mutual recognition arrangement of the International Committee for Weights and Measures (CIPM MRA). In total 19 institutes (NMIs/Dis) participated in the key comparison and the reported results of the key comparison were from 18 institutes (NMIs/DIs); 151 measurements were reported for CCQM-K127. The analytical techniques selected by the participant institutes were ICP-MS, ICP-OES, FAAS, ET-AAS and INAA (k0-method of INAA); the sample preparation methods used were based on microwave assisted digestion, except when it was used INAA. After discussions it agreed to use the median as KCRV and the MMADe as u(xKCRV). Generally most of the results of the participants were found to be consistent for all measurements according to their equivalence statements, with the exception of some extreme values, which were identified with a value of di/U(di) higher than 1. This key comparison is a means of providing evidence for practical demonstration of a CCQM comparison calibration and measurement capabilities (CMCs) claims for contaminant and others elements, in low and medium content levels in non-contaminated and contaminated matrices described in category 13. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Nuclear Information System (INIS)
1991-01-01
Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included
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Results of the Sixth International Comparison of Absolute Gravimeters, ICAG-2001
Czech Academy of Sciences Publication Activity Database
Vitushkin, L.; Becker, M.; Jiang, Z.; Francis, O.; van Dam, T. M.; Faller, J.; Chartier, J.M.; Amalvict, M.; Bonvalot, S.; Debeglia, N.; Desogus, S.; Diament, M.; Dupont, F.; Falk, R.; Gabalda, G.; Gagnon, C. G. L.; Gattacceca, T.; Germak, A.; Hinderer, J.; Jamet, O.; Jeffries, G.; Käker, R.; Kopaev, A.; Liard, J.; Lindau, A.; Longuevergne, L.; Luck, B.; Maderal, E. N.; Mäkinen, J.; Meurers, B.; Mizushima, S.; Mrlina, Jan; Newell, D.; Origlia, C.; Pujol, E. R.; Reinhold, A.; Richard, P.; Robinson, I. A.; Ruess, D.; Thies, S.; Van Camp, M.; Van Ruymbeke, M.; de Villalta Compagni, M. F.; Williams, S.
2002-01-01
Roč. 39, č. 5 (2002), s. 407-424 ISSN 0026-1394 Institutional research plan: CEZ:AV0Z3012916 Keywords : absolute gravimeters * BIPM gravity network * measurement Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.842, year: 2002
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Quantum key distribution with finite resources: Secret key rates via Renyi entropies
Energy Technology Data Exchange (ETDEWEB)
Abruzzo, Silvestre; Kampermann, Hermann; Mertz, Markus; Bruss, Dagmar [Institute for Theoretical Physics III, Heinrich-Heine-universitaet Duesseldorf, D-40225 Duesseldorf (Germany)
2011-09-15
A realistic quantum key distribution (QKD) protocol necessarily deals with finite resources, such as the number of signals exchanged by the two parties. We derive a bound on the secret key rate which is expressed as an optimization problem over Renyi entropies. Under the assumption of collective attacks by an eavesdropper, a computable estimate of our bound for the six-state protocol is provided. This bound leads to improved key rates in comparison to previous results.
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Quantum key distribution with finite resources: Secret key rates via Renyi entropies
International Nuclear Information System (INIS)
Abruzzo, Silvestre; Kampermann, Hermann; Mertz, Markus; Bruss, Dagmar
2011-01-01
A realistic quantum key distribution (QKD) protocol necessarily deals with finite resources, such as the number of signals exchanged by the two parties. We derive a bound on the secret key rate which is expressed as an optimization problem over Renyi entropies. Under the assumption of collective attacks by an eavesdropper, a computable estimate of our bound for the six-state protocol is provided. This bound leads to improved key rates in comparison to previous results.
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Activity measurements of {sup 55}Fe by two different methods
Energy Technology Data Exchange (ETDEWEB)
Cruz, P.A.L. da; Iwahara, A.; Silva, C.J. da; Poledna, R.; Loureiro, J.S.; Silva, M.A.L. da, E-mail: palcruz@ird.gov.br [Instituto de Radioproteção e Dosimetria (LNMRI/IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiações Ionizantes; Ruzzarin, Anelise [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear
2017-07-01
A calibrated germanium detector and CIEMAT/NIST liquid scintillation method were used in the standardization of solution of {sup 55}Fe coming from a key-comparison BIPM. Commercial HISAFE'3 cocktails were used in source preparation for activity measurements in CIEMAT/NIST method. Measurements were performed in Liquid Scintillation Counter. In the germanium counting method standard point sources were prepared for obtaining atomic number versus efficiency curve of the detector in order to obtain the efficiency of 5.9 keV KX-ray of {sup 55}Fe by interpolation. The activity concentrations obtained were 508.2 ± 3.56 and 510.0 ± 16.20 kBq/g, respectively for CIEMAT/NIST and germanium methods. (author)
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Spitzer, Petra; Giera, Janine; Fraga, Isabel Cristina Serta; Jakobsen, Pia Tonnes; Jensen, Hans D.; Hyllested, Peter; Karpov, Oleg; Kutovoy, Viatcheslav; Nakamura, Susumu; Vospelova, Alena; Zvezdina, Valentina
2008-01-01
CCQM-K9.2 was performed supplementary to the key comparison CCQM-K9 [1] on the pH determination of a phosphate buffer with nominal pH ~ 6.9 (at 25 °C). The sample composition was very similar in both comparisons. Only the source of the starting material used for sample preparation was different. The comparison was restricted to the use of the primary method for pH (Harned cell measurement) as defined in the IUPAC Recommendations [2]. The measurement temperatures were15 °C, 25 °C , 37...
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Final report on AFRIMETS.QM-K27: Determination of ethanol in aqueous matrix
Archer, Marcellé; Fernandes-Whaley, Maria; Visser, Ria; de Vos, Jayne; Prins, Sara; Rosso, Adriana; Ruiz de Arechavaleta, Mariana; Tahoun, Ibrahim; Kakoulides, Elias; Luvonga, Caleb; Muriira, Geoffrey; Naujalis, Evaldas; Zakaria, Osman Bin; Buzoianu, Mirella; Bebic, Jelena; Achour Mounir, Ben; Thanh, Ngo Huy
2013-01-01
Level 1; four of the ten participating laboratories submitted mean results within 1.5% of the gravimetric reference value for Level 2. Two of the participating laboratories achieved mean results within 1.5% of the gravimetric reference value for both levels. Participants in the AFRIMETS-K27 study would therefore have benefited from a pilot study in which to test their measurement capability prior to participation in the key comparison. Several NMIs, however, will still be able to make new CMC claims based on their performance in this comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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International Nuclear Information System (INIS)
1980-01-01
Section III (Neutron measurements) of the Comite Consultatif pour les Etalons de Mesure des Rayonnements ionisants held its fourth meeting in April 1979. After discussing the final report on the fast neutron fluence rate intercomparison, it requested BIPM to submit it for publication in Metrologia. Section III studied the state-of-the-art of an international comparison of a 252 Cf (10 7 s -1 ) source which is in progress. A new fast neutron fluence rate intercomparison is scheduled for 1980; the energies and the methods to be used have been investigated. Finally, Section III studied carefully and rewrote a proposal for a 14-MeV neutron dosimetry facility at BIPM, and added a Recommendation for CCEMRI [fr
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Report of the 86. meeting of the International bureau of weights and measurements, September 1997
International Nuclear Information System (INIS)
1998-01-01
The task of the BIPM is to ensure world-wide unification of physical measurements; its function is thus to: establish fundamental standards and scales for the measurement of the principal physical quantities and maintain the international standards; carry out comparisons of national and international standards; ensure the coordination of corresponding measurement techniques; carry out and coordinate measurements of the fundamental physical constants relevant to these activities. The BIPM operates under the exclusive supervision of the Comite International des Poids et Mesures (CIPM) which itself comes under the authority of the Conference Generale des Poids et Mesures (CGPM) and reports to it on the work accomplished by the BIPM. Delegates from all Member States of the Metre Convention attend the General Conference which, at present, meets every four years. The function of these meetings is to: discuss and initiate the arrangements required to ensure the propagation and improvement of the International System of Units (SI), which is the modern form of the metric system; confirm the results of new fundamental metrological determinations and various scientific resolutions of international scope; take all major decisions concerning the finance, organization and development of the BIPM. The CIPM has eighteen members each from a different State: at present, it meets every year. The officers of this committee present an annual report on the administrative and financial position of the BIPM to the Governments of the Member States of the Metre Convention. The principal task of the CIPM is to ensure world-wide uniformity in units of measurement. It does this by direct action or by submitting proposals to the CGPM. The activities of the BIPM, which in the beginning were limited to measurements of length and mass, and to metrological studies in relation to these quantities, have been extended to standards of measurement of electricity (1927), photometry and radiometry (1937
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Standardisation of 125I using seven techniques for radioactivity measurement
International Nuclear Information System (INIS)
Pomme, S.; Altzitzoglou, T.; Van Ammel, R.; Sibbens, G.
2005-01-01
Seven methods of radioactivity measurement were used to standardise an 125 I solution within the frame of an international key comparison organised by BIPM: photon-photon coincidence counting with two NaI detectors, photon sum-peak counting in a NaI well detector and in a 4π CsI(Tl) sandwich spectrometer, total emission counting in a windowless 4π CsI(Tl) sandwich spectrometer, electron-X,γ coincidence counting and electron-X,γ sum counting in a pressurised proportional counter inside a NaI well detector and liquid scintillation counting with the CIEMAT/NIST method. The solid sources were prepared by quantitative drop deposition with addition of AgNO 3 . The measurement methods, the results and the applied corrections are described and discussed
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CCQM-K108.2014: determination of arsenic species and total arsenic in brown rice flour
Inagaki, K.; Narukawa, T.; Hioki, A.; Miyashita, S.; Long, S. E.; Ellisor, M. B.; Peng, S. L.; Dewi, F.; Shin, R.; Kapp, T.; Wai-hong, F.; Hei-shing, C.; Chao, W.; Kaewkhomdee, N.; Taebunpakul, S.; Thiengmanee, U.; Yafa, C.
2017-01-01
of less than 0.1 mg/kg. These are expected that total arsenic and i-As at mass fractions greater than 0.1 mg/kg and DMAA at mass fractions greater than 0.005 mg/kg in rice flour can be determined by each participant using the same technique(s) employed for this key comparison to achieve similar uncertainties mentioned in the present report. Furthermore, the results of this key comparison can be utilised along with the IAWG core capability approach. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Shortt, K R; Huntley, R B; Kotler, L H; Boas, J F; Webb, D V
2006-06-01
Australian and Canadian calibration coefficients for air kerma and absorbed dose to water for 60Co gamma radiation have been compared using transfer standard ionization chambers of types NE 2561 and NE 2611A. Whilst the primary standards of air kerma are similar, both being thick-walled graphite cavity chambers but employing different methods to evaluate the Awall correction, the primary standards of absorbed dose to water are quite different. The Australian standard is based on measurements made with a graphite calorimeter, whereas the Canadian standard uses a sealed water calorimeter. The comparison result, expressed as a ratio of calibration coefficients R=N(ARPANSA)/N(NRC), is 1.0006 with a combined standard uncertainty of 0.35% for the air kerma standards and 1.0052 with a combined standard uncertainty of 0.47% for the absorbed dose to water standards. This demonstrates the agreement of the Australian and Canadian radiation dosimetry standards. The results are also consistent with independent comparisons of each laboratory with the BIPM reference standards. A 'trilateral' analysis confirms the present determination of the relationship between the standards, within the 0.09% random component of the combined standard uncertainty for the three comparisons.
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Energy Technology Data Exchange (ETDEWEB)
Chen, J.; Wang, Z.; Rong, C. [China Institute of Atomic Energy (CIAE), Beijing, People' s Republic of China (China); Lovestam, G.; Plompen, A.; Puglisi, N. [EC-JRC-Institute for Reference Materials and Measurements (IRMM), Geel (Belgium); Gilliam, D.M.; Eisenhauer, C.M.; Nico, J.S.; Dewey, M.S. [National Institute of Standards and Technology (NIST), Gaithersburg (United States); Kudo, K.; Uritani, A.; Harano, H.; Takeda, N. [National Metrology Institute of Japan (NMIJ), Tsukuba (Japan); Thomas, D.J.; Roberts, N.J.; Bennett, A.; Kolkowski, P. [National Physical Laboratory (NPL), Teddington (United Kingdom); Moisseev, N.N.; Kharitonov, I.A. [Mendeleyev Institute for Metrology (VNIIM), St Petersburg (Russian Federation); Guldbakke, S.; Klein, H.; Nolte, R.; Schlegel, D. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany)
2007-12-15
C.C.R.I. Section III (neutron measurements) conducted a unique key comparison of neutron fluence measurements in mono-energetic neutron fields. In contrast to former comparisons, here the fluence measurements were performed with the participants' instruments in the same neutron fields at the P.T.B. accelerator facility. Seven laboratories- the C.I.A.E. (China), I.R.M.M. (E.C.), N.M.I.J. (Japan), N.I.S.T. (USA), N.P.L. (UK), P.T.B. (Germany) and the V.N.I.I.M. (Russia)-employed their primary standard reference methods or transfer instruments carefully calibrated against their primary standards, to determine the fluence of 0.144 MeV, 1.2 MeV, 5.0 MeV and 14.8 MeV neutrons and reported calibration coefficients for a selected neutron monitor and each neutron energy with a detailed uncertainty budget for the measurements. The key comparison reference values (K.C.R.V.) were finally evaluated as the weighted mean values of the neutron fluence at 1 m distance from the target in vacuum per neutron monitor count. The uncertainties of each K.C.R.V. amounted to about 1%. The degree of equivalence (D.o.E.), defined as the deviation of the result reported by the laboratories for each energy from the corresponding K.C.R.V., and the associated expanded uncertainty are also reported. The deviations between the results of two laboratories each with the corresponding expanded uncertainties complete the documentation of the degrees of equivalence. (authors)
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Correlation determination for the free air chamber volume
International Nuclear Information System (INIS)
Cardoso, R.S.; Peixoto, J.G.P.
2017-01-01
Ionization chambers are, in principle, the simplest gaseous detectors. Its normal operation is based on the all charges collection created by gas volume direct ionization, through the application of an electric field. In order to guarantee the measurements’ traceability obtained during the comparison with the BIPM, new tests were performed. (author)
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Energy Technology Data Exchange (ETDEWEB)
Cardoso, R.S.; Peixoto, J.G.P., E-mail: ricardo@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)
2017-07-01
Ionization chambers are, in principle, the simplest gaseous detectors. Its normal operation is based on the all charges collection created by gas volume direct ionization, through the application of an electric field. In order to guarantee the measurements’ traceability obtained during the comparison with the BIPM, new tests were performed. (author)
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International Nuclear Information System (INIS)
Kharitonov, I.A.; Villevalde, N.D.; Oborin, A.V.; Fominykh, V.I.
2002-01-01
Primary standard of unities air kerma and air kerma rate X-ray and gamma radiation, placed at VNIIM, consists of: plate-parallel free-air ionization chamber IK 10-60 for low-energy X-ray in the generating potential range from 10 to 50 kV; plate-parallel free-air ionization chamber IK 50-400 for medium-energy X-ray in the generating potential range from 50 to 300 kV; cavity cylindrical graphite chambers C1 and C30 with volumes 1 cm 3 and 30 cm 3 for reproduction and transmission the dimensions gamma radiation unities using Cs-137 and Co-60 sources. The next irradiation facilities are used at VNIIM: in low-energy X-ray range: a constant-potential high-voltage generator and a tungsten-anode Xray tube with inherent filtration of around 1 mm Be; in medium-energy X-ray range: set on the basis of an industrial X-ray apparatus Isovolt-400 and a tungsten-anode X-ray tube with inherent filtration of around 3,5 mm Al; in gamma radiations field: units with a radioactive sources Cs-137 with activity 140 and 1200 GBq and Co-60 with activity 120 GBq and irradiation set with a source from Co-60 (activity 3200 GBq). The last one belongs to Central Research Institute for Radiology and Roentgenology (CNIRRI). For measuring currents and charges of standard chambers we use electrometers such as Keithley of model 6517A and B7-45 manufactured by 'Belvar' (Republic Belarus). The reference radiation qualities L, N, H series according to ISO 4037 and the radiation qualities RQR, RQA and RQF according to IEC 61267 for calibration and verification of the therapeutic, diagnostic measurement means are realized in the low-energy and medium-energy X-ray standards. The VNIIM air kerma primary standard of has been participated in the international comparisons: key comparison BIPM.R1(I)-K1 for gamma radiation of Co-60 in 1997; supplementary comparisons BIPM.R1(I)-S10 for gamma radiation of Cs-137 in 1997; key comparison BIPM.R1(I)-K2 for low-energy X-ray range in 1998; key comparison BIPM.R1(I)-K3
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Energy Technology Data Exchange (ETDEWEB)
Cooper, Oliver J.; Mills, David P.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [School of Chemistry, University of Nottingham (United Kingdom); Tuna, Floriana; McInnes, Eric J.L. [EPSRC National UK EPR Facility, School of Chemistry and Photon Science Institute, The University of Manchester (United Kingdom)
2013-05-27
Treatment of [K(BIPM{sup Mes}H)] (BIPM{sup Mes}={C(PPh_2NMes)_2}{sup 2-}; Mes=C{sub 6}H{sub 2}-2,4,6-Me{sub 3}) with [UCl{sub 4}(thf){sub 3}] (1 equiv) afforded [U(BIPM{sup Mes}H)(Cl){sub 3}(thf)] (1), which generated [U(BIPM{sup Mes})(Cl){sub 2}(thf){sub 2}] (2), following treatment with benzyl potassium. Attempts to oxidise 2 resulted in intractable mixtures, ligand scrambling to give [U(BIPM{sup Mes}){sub 2}] or the formation of [U(BIPM{sup Mes}H)(O){sub 2}(Cl)(thf)] (3). The complex [U(BIPM{sup Dipp})(μ-Cl){sub 4}(Li){sub 2}(OEt{sub 2})(tmeda)] (4) (BIPM{sup Dipp}={C(PPh_2NDipp)_2}{sup 2-}; Dipp=C{sub 6}H{sub 3}-2,6-iPr{sub 2}; tmeda=N,N,N',N'-tetramethylethylenediamine) was prepared from [Li{sub 2}(BIPM{sup Dipp})(tmeda)] and [UCl{sub 4}(thf){sub 3}] and, following reflux in toluene, could be isolated as [U(BIPM{sup Dipp})(Cl){sub 2}(thf){sub 2}] (5). Treatment of 4 with iodine (0.5 equiv) afforded [U(BIPM{sup Dipp})(Cl){sub 2}(μ-Cl){sub 2}(Li)(thf){sub 2}] (6). Complex 6 resists oxidation, and treating 4 or 5 with N-oxides gives [U(BIPM {sup Dipp}H)(O){sub 2}-(μ-Cl){sub 2}Li(tmeda)] (7) and [{U(BIPM"D"i"p"pH)(O)_2(μ-Cl)}{sub 2}] (8). Treatment of 4 with tBuOLi (3 equiv) and I{sub 2} (1 equiv) gives [U(BIPM{sup Dipp})(OtBu){sub 3}(I)] (9), which represents an exceptionally rare example of a crystallographically authenticated uranium(VI)-carbon σ bond. Although 9 appears sterically saturated, it decomposes over time to give [U(BIPM{sup Dipp})(OtBu){sub 3}]. Complex 4 reacts with PhCOtBu and Ph{sub 2}CO to form [U(BIPM{sup Dipp})(μ-Cl){sub 4}(Li){sub 2}(tmeda)(OCPhtBu)] (10) and [U(BIPM{sup Dipp})(Cl)(μ-Cl){sub 2}(Li)(tmeda)(OCPh{sub 2})] (11). In contrast, complex 5 does not react with PhCOtBu and Ph{sub 2}CO, which we attribute to steric blocking. However, complexes 5 and 6 react with PhCHO to afford (DippNPPh{sub 2}){sub 2}C=C(H)Ph (12). Complex 9 does not react with PhCOtBu, Ph{sub 2}CO or PhCHO; this is attributed to steric blocking
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International Nuclear Information System (INIS)
Li Chunjuan; Liu Yi'na; Zhang Weihua; Wang Zhiqiang
2014-01-01
The manganese bath method for measuring the neutron emission rate of radionuclide sources requires corrections to be made for emitted neutrons which are not captured by manganese nuclei. The Monte Carlo particle transport code MCNP was used to simulate the manganese bath system of the standards for the measurement of neutron source intensity. The correction factors were calculated and the reliability of the model was demonstrated through the key comparison for the radionuclide neutron source emission rate measurements organized by BIPM. The uncertainties in the calculated values were evaluated by considering the sensitivities to the solution density, the density of the radioactive material, the positioning of the source, the radius of the bath, and the interaction cross-sections. A new method for the evaluation of the uncertainties in Monte Carlo calculation was given. (authors)
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Westwood, S.; Josephs, R.; Daireaux, A.; Wielgosz, R.; Davies, S.; Kang, M.; Ting, H.; Phillip, R.; Malz, F.; Shimizu, Y.; Frias, E.; Pérez, M.; Apps, P.; Fernandes-Whaley, M.; DeVos, B.; Wiangnon, K.; Ruangrittinon, N.; Wood, S.; Duewer, D.; Schantz, M.; Bedner, M.; Hancock, D.; Esker, J.
2009-01-01
Under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a laboratory comparison, CCQM-P20.e, was coordinated by the Bureau International de Poids et Mesures (BIPM) in 2006/2007. Nine national measurement institutes, two expert laboratories and the BIPM participated in the comparison. Participants were required to assign the mass fraction of theophylline present as the main component in two separate study samples (CCQM-P20.e.1 and CCQM-P20.e.2). CCQM-P20.e.1 consisted of a high-purity theophylline material obtained from a commercial supplier. CCQM-P20.e.2 consisted of theophylline to which known amounts of the related structure compounds theobromine and caffeine were added in a homogenous, gravimetrically controlled fashion. For the CCQM-P20.e.2 sample it was possible to estimate gravimetric reference values both for the main component and for the two spiked impurities. In addition to assigning the mass fraction content of theophylline for both materials, participants were requested but not obliged to provide mass fraction estimates for the minor components they identified in each sample. The results reported by the study participants for the mass fraction content of theophylline in both materials showed good levels of agreement both with each other and with the gravimetric reference value assigned to the CCQM-P20.e.2 material. There was also satisfactory agreement overall, albeit at higher levels of uncertainty, in the quantification data reported for the minor components present in both samples. In the few cases where a significant deviation was observed from the consensus values reported by the comparison participants or gravimetric reference values where these where available, they appeared to arise from the use of non-optimal chromatographic separation conditions. The results demonstrate the feasibility for laboratories to assign mass fraction content with associated absolute expanded
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Key parameters controlling radiology departments
International Nuclear Information System (INIS)
Busch, Hans-Peter
2011-01-01
For radiology departments and outstanding practises control and optimization of processes demand an efficient management based on key data. Systems of key data deliver indicators for control of medical quality, service quality and economics. For practices effectiveness (productivity), for hospitals effectiveness and efficiency are in the focus of economical optimization strategies. Task of daily key data is continuous monitoring of activities and workflow, task of weekly/monthly key data is control of data quality, process quality and achievement of objectives, task of yearly key data is determination of long term strategies (marketing) and comparison with competitors (benchmarking). Key parameters have to be defined clearly and have to be available directly. For generation, evaluation and control of key parameters suitable forms of organization and processes are necessary. Strategies for the future will be directed more to the total processes of treatment. To think in total processes and to steer and optimize with suitable parameters is the challenge for participants in the healthcare market of the future. (orig.)
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Clairon, A.; Dahmani, B.; Acef, O.; Granveaud, M.; Domnin, Yu S.; Pouchkine, S. B.; Tatarenkov, V. M.; Felder, R.
1988-01-01
Comparison of the VNIIFTRI and LPTF frequency multiplication chains has been carried out through the measurement of the frequency of a portable VNIIFTRI (He-Ne)/CH4 laser. Agreement is within 100 Hz (1.1 parts in 1012) and is secured by the very good medium-term frequency repeatability of the (He-Ne)/CH4 VNIIFTRI portable laser (a few parts in 1013). On the same occasion a measurement of the frequency of the BIPM (He-Ne)/CH4 reference laser (B.3) has been performed at LPTF. Other experiments carried out on the BIPM laser show that the reproducibility of the (He-Ne)/CH4 system could be improved by a systematic study and then by a better control of the various perturbing factors which influence the shape of the methane-saturated absorption peak.
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Advisory Committee for the Calibration Standards of Ionizing Radiation Measurement
International Nuclear Information System (INIS)
1982-01-01
An account of the activity during the past two years and of the plans for future work is given for the three Sections of the Comite Consultatif pour les Etalons de Mesure des Rayonnements Ionisants. Section I (Rayons X et #betta#, electrons) studied in detail the results of an intercomparison of Frike dosimeters. A recommendation was made concerning the possibility of expressing calibrations made in terms of exposure in terms of air kerma or water kerma. Section II (Mesure des radionucleides) studied the results of recent international comparisons ( 55 Fe, 133 Ba and 134 Cs) and made plans for new ones. Section III (Mesures neutroniques) presented the status of the international comparisons of neutron fluence rate in progress and decided to organize new ones. The reports of the Section chairmen are followed by the presentation of the work carried out at BIPM by the corresponding groups. The status of the proposal by Section III for a 14 MeV neutron dosimetry facility at BIPM is discussed in detail and a proposal is made for a neutron dosimetry intercomparison [fr
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Research of user key management mechanisms in the cloud
Directory of Open Access Journals (Sweden)
Іван Федорович Аулов
2016-06-01
Full Text Available The results of comparison and recommendations on the use of existing user key management mechanisms in the cloud environment are given. New generation and installing mechanism of a private key pair between the N-means of key management in the cloud by using a modified Diffie-Hellman protocol is proposed
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Energy Technology Data Exchange (ETDEWEB)
Roberts, N.J.; Jones, L.N. [National Physical Laboratory (NPL), Teddington, (United Kingdom); Wang, Z.; Liu, Y.; Wang, Q.; Chen, X.; Luo, H.; Rong, C. [China Institute of Atomic Energy (CIAE), Beijing (China); Kralik, M. [Czech Metrology Institute (CMI), Praha, (Czech Republic); Park, H.; Choi, K.O. [Korea Research Institute of Standards and Science (KRISS), Daejeon, (Korea, Republic of); Pereira, W.W.; Da Fonseca, E.S. [National Laboratory of Metrology of Ionizing Radiation (LNMRI), Rio de Janeiro, (Brazil); Cassette, P. [Laboratoire National Henri Becquerel (LNE-LNHB), Paris, (France); Dewey, M.S. [National Institute of Standards and Technology (NIST), Gaithersburg, MD, (United States); Moiseev, N.N.; Kharitonov, I.A. [D I Mendeleyev Institute for Metrology (VNIIM), St Petersburg, (Russian Federation)
2011-07-01
Section III (neutron measurements) of the Comite Consultatif des Rayonnements Ionisants, CCRI, conducted a key comparison of primary measurements of the neutron emission rate of an {sup 241}Am-Be({alpha},n) radionuclide source. A single {sup 241}Am-Be({alpha},n) source was circulated to all the participants between 1999 and 2005. Eight laboratories participated - the CIAE (China), CMI (Czech Republic), KRISS (Republic of Korea), LNMRI (Brazil), LNE-LNHB (France), NIST (USA), NPL (UK) and the VNIIM (Russian Federation) - with the NPL making their measurements at the start and repeating them near the end of the exercise to verify the stability of the source. Each laboratory reported the emission rate into 4{pi} sr together with a detailed uncertainty budget. All participants used the manganese bath technique, with the VNIIM also making measurements using an associated particle technique. The CMI, KRISS, VNIIM, and later the NPL, also measured the anisotropy of the source although this was not a formal part of the comparison. The first draft report was released in May 2006 and having been discussed and modified by the participants and subsequently reviewed by the CCRI(III), the present paper is now the final report of the comparison. (authors)
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International Nuclear Information System (INIS)
1982-01-01
Section III (Mesures neutroniques) of the Comite Consultatif pour les Etalons de Mesure des Rayonnements Ionisants held its fifth meeting in May 1981. Recent work carried out at BIPM in the field of neutron measurements was reported. The status of a full-scale 252 Cf neutron source intercomparison (10 7 s - 1 ) and of several restricted comparisons was discussed. Intercomparisons of fast neutron fluence rates are in progress ( 115 In(n,n') 115 Insup(m); NB/Zr) or will take place in the near future ( 115 n(n,#betta#) 116 Insup(m); 235 U and 238 U fission chambers). An intercomparison of neutron dosimetry standards by circulating tissue-equivalent ion chambers will be prepared and organized by BIPM. Finally, there was a broad exchange of information on work in progress at the various laboratories represented at the meeting [fr
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ClinicalKey: a point-of-care search engine.
Vardell, Emily
2013-01-01
ClinicalKey is a new point-of-care resource for health care professionals. Through controlled vocabulary, ClinicalKey offers a cross section of resources on diseases and procedures, from journals to e-books and practice guidelines to patient education. A sample search was conducted to demonstrate the features of the database, and a comparison with similar tools is presented.
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Meyer, C.W.; Hill, K.D.
2015-01-01
A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures was carried out by the National Institute of Standards and Technology (NIST, USA) and the National Research Council (NRC, Canada) between December 2014 and April, 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and NRC and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining degree of equivalence between the dew/frost-point standards of NIST and NRC. PMID:26663952
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Meyer, C W; Solano, A
2016-01-01
A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures over the range -30 °C TO +20 °C was carried out by the National Institute of Standards and Technology (NIST, USA) and the Laboratorio Costarricense de Metrología (LACOMET, Costa Rica), between February 2015 and August 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and LACOMET and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining the degree of equivalence between the dew/frost-point standards of NIST and LACOMET.
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SSDL newsletter. No. 53, January 2007
International Nuclear Information System (INIS)
2007-01-01
This issue of the SSDL Newsletter contains three contributions. The first contribution is a presentation of the SSDL of South Africa (a member of the IAEA/WHO Network since 2001), which has also been nominated as a Regionally Designed Centre for calibration activities in Africa. The second contribution is a brief note on a recently published IAEA guidance document, Technical Reports Series No. 454, on 'Quality Assurance for Radioactivity Measurement in Nuclear Medicine'. The document is currently available on-line at the IAEA Publications Website and in hardcopy. The third contribution is a brief note on the IAEA calibration and Measurement Capabilities (CMCs) and related Quality Management System (QMS). The IAEA CMCs were published in Appendix C of the BIPM Key Comparison Database in June 2002. The IAEA QMS, which is based on ISO/IEC 17025, was peer-reviewed by a panel of four independent experts in 2004. At the invitation of the International Committee of Weights and Measures (CIPM), the IAEA QMS was presented for review by a panel of experts identified by the Regional Metrology Organizations (RMOs). The Joint Committee of the Regional Metrology Organizations and the BIPM JCRB approved the IAEA QMS on 6 October 2006. The IAEA QMS is reviewed every four years by a panel of independent experts, and every two years by selected external members of the IAEA/WHO Standing Advisory Committee. The IAEA will, whenever possible and if resources permit, support SSDL members in the establishment of a QMS based on ISO/IEC 17025
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Meyer, C.W.; Solano, A.
2016-01-01
A Regional Metrology Organization (RMO) Key Comparison of dew/frost point temperatures over the range −30 °C TO +20 °C was carried out by the National Institute of Standards and Technology (NIST, USA) and the Laboratorio Costarricense de Metrología (LACOMET, Costa Rica), between February 2015 and August 2015. The results of this comparison are reported here, along with descriptions of the humidity laboratory standards for NIST and LACOMET and the uncertainty budget for these standards. This report also describes the protocol for the comparison and presents the data acquired. The results are analyzed, determining the degree of equivalence between the dew/frost-point standards of NIST and LACOMET. PMID:28066029
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Key Management in Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Ismail Mansour
2015-09-01
Full Text Available Wireless sensor networks are a challenging field of research when it comes to security issues. Using low cost sensor nodes with limited resources makes it difficult for cryptographic algorithms to function without impacting energy consumption and latency. In this paper, we focus on key management issues in multi-hop wireless sensor networks. These networks are easy to attack due to the open nature of the wireless medium. Intruders could try to penetrate the network, capture nodes or take control over particular nodes. In this context, it is important to revoke and renew keys that might be learned by malicious nodes. We propose several secure protocols for key revocation and key renewal based on symmetric encryption and elliptic curve cryptography. All protocols are secure, but have different security levels. Each proposed protocol is formally proven and analyzed using Scyther, an automatic verification tool for cryptographic protocols. For efficiency comparison sake, we implemented all protocols on real testbeds using TelosB motes and discussed their performances.
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Quality Management and Key Performance Indicators in Oncologic Esophageal Surgery.
Gockel, Ines; Ahlbrand, Constantin Johannes; Arras, Michael; Schreiber, Elke Maria; Lang, Hauke
2015-12-01
Ranking systems and comparisons of quality and performance indicators will be of increasing relevance for complex "high-risk" procedures such as esophageal cancer surgery. The identification of evidence-based standards relevant for key performance indicators in esophageal surgery is essential for establishing monitoring systems and furthermore a requirement to enhance treatment quality. In the course of this review, we analyze the key performance indicators case volume, radicality of resection, and postoperative morbidity and mortality, leading to continuous quality improvement. Ranking systems established on this basis will gain increased relevance in highly complex procedures within the national and international comparison and furthermore improve the treatment of patients with esophageal carcinoma.
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Feistel, R.; Wielgosz, R.; Bell, S. A.; Camões, M. F.; Cooper, J. R.; Dexter, P.; Dickson, A. G.; Fisicaro, P.; Harvey, A. H.; Heinonen, M.; Hellmuth, O.; Kretzschmar, H.-J.; Lovell-Smith, J. W.; McDougall, T. J.; Pawlowicz, R.; Ridout, P.; Seitz, S.; Spitzer, P.; Stoica, D.; Wolf, H.
2016-02-01
Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest ‘greenhouse’ gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organizations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology.
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The dosimetry programme of the IAEA
International Nuclear Information System (INIS)
1987-01-01
Describes the activities of the IAEA's Dosimetry Laboratory which provides calibration and comparison services for secondary standard dosimetry laboratories (SSDLs) of Member States. In addition, a joint IAEA/WHO postal dosimetry service has been established for radiotherapy centers. The International Measurement System and the calibration ''chain'' from measurement standard instruments of the International Bureau of Weights and Measurements (BIPM) through the primary and secondary standards to the dosimeters of the users are presented as well
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Quantum key distribution without alternative measurements
Cabello, A
2000-01-01
Entanglement swapping between Einstein-Podolsky-Rosen (EPR) pairs can be used to generate the same sequence of random bits in two remote places. A quantum key distribution protocol based on this idea is described. The scheme exhibits the following features. (a) It does not require that Alice and Bob choose between alternative measurements, therefore improving the rate of generated bits by transmitted qubit. (b) It allows Alice and Bob to generate a key of arbitrary length using a single quantum system (three EPR pairs), instead of a long sequence of them. (c) Detecting Eve requires the comparison of fewer bits. (d) Entanglement is an essential ingredient. The scheme assumes reliable measurements of the Bell operator. (20 refs).
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Activity standardisation of 18F and ionisation chamber calibration for nuclear medicine
International Nuclear Information System (INIS)
Schrader, H.; Klein, R.; Kossert, K.
2007-01-01
Primary activity standardisations were performed on solutions of 18 F using 4πβ-γ coincidence counting and liquid scintillation counting (LSC) according to the CIEMAT/NIST method. A β + -emission probability of 96.86% was used for both methods. The various standardised 18 F solutions were measured in ionisation chambers of the Physikalisch-Technische Bundesanstalt (PTB) and compared by determining radionuclide calibration factors. Already in 2001 an 18 F solution had been standardised at the PTB and compared with the results of nine national metrology institutes (NMIs), using the ISOCAL IV secondary radionuclide calibrators of the National Physical Laboratory (NPL) as transfer instruments and a 68 Ge check source solution. These results were linked to the International Reference System (SIR) at the Bureau International des Poids et Mesures (BIPM) by aliquots of solutions sent by the Laboratoire National Henri Becquerel (BNM-LNHB) and the NPL. Further on, in 2005, PTB sent an aliquot of an 18 F solution to the SIR for ionisation chamber measurements. A value of the equivalent activity was determined and included in the key comparison database (KCDB). The recent PTB value of the equivalent activity of the SIR is in good agreement with the key comparison reference value determined from five NMIs. These results confirm that the standardisation of 18 F solutions can be achieved with the accuracy required for use in nuclear medicine and, in particular, for applications in positron emission tomography (PET)
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DecreaseKeys are Expensive for External Memory Priority Queues
Eenberg, Kasper; Larsen, Kasper Green; Yu, Huacheng
2016-01-01
One of the biggest open problems in external memory data structures is the priority queue problem with DecreaseKey operations. If only Insert and ExtractMin operations need to be supported, one can design a comparison-based priority queue performing $O((N/B)\\lg_{M/B} N)$ I/Os over a sequence of $N$ operations, where $B$ is the disk block size in number of words and $M$ is the main memory size in number of words. This matches the lower bound for comparison-based sorting and is hence optimal fo...
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Teo, Tang Lin; Gui, Ee Mei; Lu, Ting; Sze Cheow, Pui; Giannikopoulou, Panagiota; Kakoulides, Elias; Lampi, Evgenia; Choi, Sik-man; Yip, Yiu-chung; Chan, Pui-kwan; Hui, Sin-kam; Wollinger, Wagner; Carvalho, Lucas J.; Garrido, Bruno C.; Rego, Eliane C. P.; Ahn, Seonghee; Kim, Byungjoo; Li, Xiuqin; Guo, Zhen; Styarini, Dyah; Aristiawan, Yosi; Putri Ramadhaningtyas, Dillani; Aryana, Nurhani; Ebarvia, Benilda S.; Dacuaya, Aaron; Tongson, Alleni; Aganda, Kim Christopher; Junvee Fortune, Thippaya; Tangtrirat, Pradthana; Mungmeechai, Thanarak; Ceyhan Gören, Ahmet; Gündüz, Simay; Yilmaz, Hasibe
2017-01-01
/kg with a combined standard uncertainty of 1.36 mg/kg. The k-factors for the estimation of the expanded uncertainties of the SCRVs were 2.26, 2.57 and 2.57, respectively. The degree of equivalence (with the SCRV) and its uncertainty were calculated for each result. All the participating institutes (except in one case for benzoic acid) were able to demonstrate or confirm their capabilities in the determination of polar food preservatives in water or aqueous-based beverages/condiments. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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THE EFFECT OF TEACHING WITHIN-TEXT KEY WORDS ON STUDENTS’ PERFORMANCE IN READING COMPREHENSION
Directory of Open Access Journals (Sweden)
Mohammad Reza Khodasenas
2013-07-01
Full Text Available Abstract: The present study was conducted to investigate the effects of teaching within-text key word synonyms, opposites and related words on students’ performance on reading comprehension of TOEFL among Iranian EFL learners. To carry out the research, 60 Iranian EFL learners, who participated in a TOEFL preparation course, were selected as the participants of the study. Afterward they were randomly assigned into experimental and comparison groups. The experimental group was given a treatment including within-text key word synonyms, opposites and their translations, while the comparison group was given a placebo. To collect the required data, two instruments (a pre-test, and a post-test were administered to both groups during the experimentation. Subsequently, students’ scores were collected through the administration of different tests and the results were statistically analyzed. The results of these analyses revealed that the experimental group outperformed the comparison group and thus, it was concluded that teaching within-text key word synonyms, opposites and related words can improve the reading comprehension ability and general proficiency of EFL language learners.
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Counet, Christine; Callemien, Delphine; Ouwerx, Caroline; Collin, Sonia
2002-04-10
After vacuum distillation and liquid-liquid extraction, the volatile fractions of dark chocolates were analyzed by gas chromatography-olfactometry and gas chromatography-mass spectrometry. Aroma extract dilution analysis revealed the presence of 33 potent odorants in the neutral/basic fraction. Three of these had a strong chocolate flavor: 2-methylpropanal, 2-methylbutanal, and 3-methylbutanal. Many others were characterized by cocoa/praline-flavored/nutty/coffee notes: 2,3-dimethylpyrazine, trimethylpyrazine, tetramethylpyrazine, 3(or 2),5-dimethyl-2(or 3)-ethylpyrazine, 3,5(or 6)-diethyl-2-methylpyrazine, and furfurylpyrrole. Comparisons carried out before and after conching indicate that although no new key odorant is synthesized during the heating process, levels of 2-phenyl-5-methyl-2-hexenal, Furaneol, and branched pyrazines are significantly increased while most Strecker aldehydes are lost by evaporation.
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Dynamic test of the ITER blanket key and ceramic insulated pad
International Nuclear Information System (INIS)
Khomyakov, S.; Sysoev, G.; Strebkov, Yu.; Kucherov, A.; Ioki, K.
2010-01-01
The dynamic testing of the blanket module's key integrated into ITER vacuum vessel portion has been performed in 2008 to investigate its capability to react the electro-magnetic (EM) loads. The preliminary analysis showed the large dynamic amplification factor (DAF) of the reactions because of technological gaps between the blanket module and key. Shock load may yield the bronze pads, which protect the blanket electrical insulation from damage. However the dynamic analysis of such particularly non-linear system needs an experimental ground and confirmation. Toward this end, as well as demonstration of the key reliability, the special test facility has been made, and the full-scale mock-up of the inboard intermodular key was tested. So as not to scale non-linear dynamic parameters, 1-ton mass was built on the single flexible support. The key was welded in a 60-mm thick steel plate modeled with a fragment of the VV. The different gaps were set in between the bronze pad of the key and the mass shock worker. This system (supplemented with some additional constraints) has natural oscillations like as the 4-ton module built on four flexible supports. Thus the most critical radial torque might be modeled with a straight force. The objectives of the test were as follows: dynamic response, DAF and damping factor determination; measurement of the strain oscillations in the key's base and in the weld seam; comparison of the measured data with computation results. The paper will present the analytical grounds of the testing conditions, test facility description, analytical adaptation of the facility, experimental results, its comparison with analysis and discussion, and guidelines for the next experimental phase.
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Thomas, Claudine
1994-01-01
The Global Positioning System is an outstanding tool for the dissemination of time. Using mono-channel C/A-code GPS time receivers, the restitution of GPS time through the satellite constellation presents a peak-to-peak discrepancy of several tens of nanoseconds without SA but may be as high as several hundreds of nanoseconds with SA. As a consequence, civil users are more and more interested in implementing hardware and software methods for efficient restitution of GPS time, especially in the framework of the project of a real-time prediction of UTC (UTCp) which could be available in the form of time differences (UTCp - GPS time). Previous work, for improving the real-time restitution of GPS time with SA, to the level obtained without SA, focused on the implementation of a Kalman filter based on past data and updated at each new observation. An alternative solution relies upon the statistical features of the noise brought about by SA; it has already been shown that the SA noise is efficiently reduced by averaging data from numerous satellites observed simultaneously over a sufficiently long time. This method was successfully applied to data from a GPS time receiver, model AOA TTR-4P, connected to the cesium clock kept at the BIPM. This device, a multi-channel, dual frequency, P-code GPS time receiver, is one of the first TTR-4P units in operation in a civil laboratory. Preliminary comparative studies of this new equipment with conventional GPS time receivers are described in this paper. The results of an experimental restitution of GPS time, obtained in June 1993, are also detailed: 3 to 6 satellites were observed simultaneously with a sample interval of 15 s, an efficient smoothing of SA noise was realized by averaging data on all observed satellites over more than 1 hour. When the GPS system is complete in 1994, 8 satellites will be observable continuously from anywhere in the world and the same level of uncertainty will be obtained using a shorter averaging
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Improved two-way six-state protocol for quantum key distribution
International Nuclear Information System (INIS)
Shaari, J.S.; Bahari, Asma' Ahmad
2012-01-01
A generalized version for a qubit based two-way quantum key distribution scheme was first proposed in the paper [Phys. Lett. A 358 (2006) 85] capitalizing on the six quantum states derived from three mutually unbiased bases. While boasting of a higher level of security, the protocol was not designed for ease of practical implementation. In this work, we propose modifications to the protocol, resulting not only in improved security but also in a more efficient and practical setup. We provide comparisons for calculated secure key rates for the protocols in noisy and lossy channels. -- Highlights: ► Modification for efficient generalized two-way QKD is proposed. ► Calculations include secure key rates in noisy and lossy channels for selected attack scenario. ► Resulting proposal provides for higher secure key rate in selected attack scheme.
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Improved two-way six-state protocol for quantum key distribution
Energy Technology Data Exchange (ETDEWEB)
Shaari, J.S., E-mail: jesni_shamsul@yahoo.com [Faculty of Science, International Islamic University Malaysia (IIUM), Jalan Sultan Ahmad Shah, Bandar Indera Mahkota, 25200 Kuantan, Pahang (Malaysia); Bahari, Asma' Ahmad [Faculty of Science, International Islamic University Malaysia (IIUM), Jalan Sultan Ahmad Shah, Bandar Indera Mahkota, 25200 Kuantan, Pahang (Malaysia)
2012-10-01
A generalized version for a qubit based two-way quantum key distribution scheme was first proposed in the paper [Phys. Lett. A 358 (2006) 85] capitalizing on the six quantum states derived from three mutually unbiased bases. While boasting of a higher level of security, the protocol was not designed for ease of practical implementation. In this work, we propose modifications to the protocol, resulting not only in improved security but also in a more efficient and practical setup. We provide comparisons for calculated secure key rates for the protocols in noisy and lossy channels. -- Highlights: ► Modification for efficient generalized two-way QKD is proposed. ► Calculations include secure key rates in noisy and lossy channels for selected attack scenario. ► Resulting proposal provides for higher secure key rate in selected attack scheme.
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Recommendations of the first meeting of the SSDL Scientific Committee. Vienna, 12-15 May 1986
International Nuclear Information System (INIS)
1986-01-01
The Advisory Group on Secondary Standard Dosimetry Laboratories, convened 19-23 November 1984, recommended the utilization of the ionometric method for comparison of standards within the SSDL Network. The SSDL Scientific Committee has noted that the principles and the first recommendations laid down by the Advisory Group at its 1984 meeting have been implemented. The Committee is confident that a continued improvement of the SSDL Network is possible. The Committee has examined the SSDL Reports for 1985 during its current meeting and has noted that 37 out of 49 SSDLs submitted a report. The Committee was impressed by the work reported by a number of SSDLs. However, no report has been received from 12 SSDLs and some of the laboratories were minimally active. For these reasons the Committee recommends that a programme be initiated that could evaluate and increase the efficiency of the Network. The Committee considers it necessary that direct traceability to the International Bureau of Weights nd Measures (BIPM) be maintained with adequate accuracy. Such traceability already exists between the IAEA Dosimetry Laboratory and the BIPM. Although the BIPM cannot deal directly with all of the members of the Network, the IAEA Laboratory can provide such traceability without essential loss in accuracy. As a first step in achieving the proposed programme, the Committee recommends that the SSDLs be officially informed that membership in the Network is dependent upon periodic successful participation in performance evaluations that demonstrate adequate consistency with the international system of measurements. If, in a given country, an SSDL organization exists, then this organization must choose one of its member laboratories to take part in such a performance evaluation. The Committee recommends that the first performance evaluation be completed for all current SSDLs before July 1988. The Committee proposes two methods that may be used to perform such evaluations. The IAEA
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Means to form key competencies by teaching „Chemistry and environmental protection” in grade 8
International Nuclear Information System (INIS)
Manev, Stefan; Dimitrova, Velichka; Gushterova, Pavlina
2011-01-01
Abstract: A comparison was made of expected results set in grade 8 „Chemistry and environment preservation” curriculum and requirements to form one of eight key competencies „Mathematical literacy and basic knowledge in science and technologies”. The results obtained allow to make some recommendations towards improvement of teaching through a more effective use of science content to form key competencies. Keywords: teaching, science, chemistry, key competencies, curriculum
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Key Elements of a Good Mathematics Lesson as Seen by Japanese Junior High School Teachers
Ebaeguin, Marlon; Stephens, Max
2016-01-01
This study makes a comparison between what literature on Japanese Lesson Study suggests are key elements of a good mathematics lesson and what junior high school mathematics teachers in Japan value in planning their lessons. The teachers' strong consensus in their endorsements of these key elements explains why Japanese teachers strongly support…
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Newell, D. B.
2012-12-01
key standards are being performed and similar components used in the operation of the watt balances are being jointly verified. To this end, a comparison between the gravitational measurement systems used in conjunction with the NIST and NRC watt balances was carried out in early 2012. The results of the comparison provide verification of the gravity values used in the recently published Planck constant determinations that play a vital role in the redefinition effort of the SI. [1] Resolution 1 of the 24th Meeting of the General Conference on Weights and Measures (CGPM) 2011 On the possible future revision of the International System of Units, Bureau International des Poids et Mesures, Paris, http://www.bipm.org/en/si/new_si/ [2] Steiner R L, Williams E R, Liu R, and Newell D B 2007 Uncertainty Improvements of the NIST Electronic Kilogram, IEEE Trans. Instrum. Meas., 56 2 592-596 [3] Steele A G, Meija J, Sanchez C A, Yang L, Wood B M, Sturgeon R E, Mester Z and Inglis A D 2012 Reconciling Planck constant determinations via watt balance and enriched-silicon measurements at NRC Canada Metrologia 49 1 L8-L10
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Application of the Value Optimization Model of Key Factors Based on DSEM
Directory of Open Access Journals (Sweden)
Chao Su
2016-01-01
Full Text Available The key factors of the damping solvent extraction method (DSEM for the analysis of the unbounded medium are the size of bounded domain, the artificial damping ratio, and the finite element mesh density. To control the simulation accuracy and computational efficiency of the soil-structure interaction, this study establishes a value optimization model of key factors that is composed of the design variables, the objective function, and the constraint function system. Then the optimum solutions of key factors are obtained by the optimization model. According to some comparisons of the results provided by the different initial conditions, the value optimization model of key factors is feasible to govern the simulation accuracy and computational efficiency and to analyze the practical unbounded medium-structure interaction.
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International Nuclear Information System (INIS)
Mattsson, Olof
1988-01-01
In 1985 a comparison of different revised protocols for the dosimetry of high-energy photon and electron beams was published (Mattsson, 1985). The conclusions were that the agreement in absorbed dose to water determined using the different protocols is very good and that the agreement between ionization chamber and ferrous sulphate dosimetry is generally good. For electron beams the differences obtained with the ionization chamber and ferrous sulphate dosimeters were up to about 2%. The influence of the energy and angular distribution of the electron beams on the ionization chamber dosimetry is not fully considered in the dosimetry protocols. The basis for the ionization chamber dosimetry has recently been changed when the Bureau International des Poids et Mesures (BIPM) in 1986 changed the air-kerma standard. The reason was the adaption of the new stopping-power values reported in the ICRU Report No. 37. To achieve consistency in the ionization chamber dosimetry the interaction coefficients and correction factors given in the dosimetry protocols should also be based on the same set of stopping-power values. This is not the case with the protocols included in the comparison made by Mattsson. However, in the international code of practice by the International Atomic Energy Agency (IAEA, 1987) the new stopping-power values have been used. The formalism is the same as in most of the previous protocols. Mattsson et al. (1989) have shown that the differences in the various steps cancel out for the protocols published by NACP (1980) and by IAEA (1987) for cobalt-60 gamma quality. However, it is also of interest to investigate the influence of the new air-kerma standard and the new values on coefficients and factors given in the IAEA protocol for other beam qualities. Therefore, the data given by Mattsson (1985) have been recalculated using the new air-kerma standard and the IAEA protocol
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Tomographic Approach in Three-Orthogonal-Basis Quantum Key Distribution
International Nuclear Information System (INIS)
Liang Wen-Ye; Yin Zhen-Qiang; Chen Hua; Li Hong-Wei; Chen Wei; Han Zheng-Fu; Wen Hao
2015-01-01
At present, there is an increasing awareness of some three-orthogonal-basis quantum key distribution protocols, such as, the reference-frame-independent (RFI) protocol and the six-state protocol. For secure key rate estimations of these protocols, there are two methods: one is the conventional approach, and another is the tomographic approach. However, a comparison between these two methods has not been given yet. In this work, with the general model of rotation channel, we estimate the key rate using conventional and tomographic methods respectively. Results show that conventional estimation approach in RFI protocol is equivalent to tomographic approach only in the case of that one of three orthogonal bases is always aligned. In other cases, tomographic approach performs much better than the respective conventional approaches of the RFI protocol and the six-state protocol. Furthermore, based on the experimental data, we illustrate the deep connections between tomography and conventional RFI approach representations. (paper)
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Final report for CCQM-K107: total elements and selenomethionine in human serum
Goenaga Infante, Heidi
2016-01-01
and solids) at a similar level of performance using the same measurement technique applied in CCQM-K107 provided that there are no additional factors (e.g. blank or dissolution issues). CMC claims based on SeMet measurements in this study may be applied to other biological matrices (e.g., tissues) provided that the concentration range is similar and due diligence is taken to ensure an appropriate extraction process is achieved and species specific spikes are available for quantitation by isotope dilution. Indeed, having accepted such conditions, application to quantitation of other organometallic species and other elements in similar matrices should be possible with the same level of performance. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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Key-value store with internal key-value storage interface
Bent, John M.; Faibish, Sorin; Ting, Dennis P. J.; Tzelnic, Percy; Gupta, Uday; Grider, Gary; Bonnie, David J.
2018-01-16
A key-value store is provided having one or more key-value storage interfaces. A key-value store on at least one compute node comprises a memory for storing a plurality of key-value pairs; and an abstract storage interface comprising a software interface module that communicates with at least one persistent storage device providing a key-value interface for persistent storage of one or more of the plurality of key-value pairs, wherein the software interface module provides the one or more key-value pairs to the at least one persistent storage device in a key-value format. The abstract storage interface optionally processes one or more batch operations on the plurality of key-value pairs. A distributed embodiment for a partitioned key-value store is also provided.
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2009-11-01
VNIIFTRI and the PTB [7]. GPS time transfer represents today about 85% of the time links for TAI; in this technique, we make use of different types...campaign visited the PTB, the VNIIFTRI , and the AOS [8]. Already in 1996, the use of GLONASS in standard CGGTTS Common-View mode was proposed, but...are compared on regular basis to GPS and TWSTFT methods [16]. Also, with the agreement of the CCTF (2009), the link between the PTB and VNIIFTRI
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Directory of Open Access Journals (Sweden)
Tieyu Zhao
2015-01-01
Full Text Available The optical image encryption has attracted more and more researchers’ attention, and the various encryption schemes have been proposed. In existing optical cryptosystem, the phase functions or images are usually used as the encryption keys, and it is difficult that the traditional public-key algorithm (such as RSA, ECC, etc. is used to complete large numerical key transfer. In this paper, we propose a key distribution scheme based on the phase retrieval algorithm and the RSA public-key algorithm, which solves the problem for the key distribution in optical image encryption system. Furthermore, we also propose a novel image encryption system based on the key distribution principle. In the system, the different keys can be used in every encryption process, which greatly improves the security of the system.
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Advisory Committee for the calibration standards of ionizing radiation measurement
International Nuclear Information System (INIS)
1979-01-01
The meeting consisted exceptionally of two sessions (in May and December 1977). The members discussed the comparisons of absorbed dose standards and exposure standards which had taken place since 1975 and suggested improvements for future comparisons. A recommendation was made concerning the humidity correction factor to be applied when using cavity chambers and free-air chambers. Further studies were requested concerning the effective point of measurement of ionization chambers. No method was recommended for the statement of uncertainty in calibration certificates. The exposure standards and calibrations in terms of exposure were maintained but it was agreed that other possibilities should be explored. Finally, progress reports of the national laboratories and a description of the recent work carried out at BIPM were presented and appear as appendices to the report [fr
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Key Management for Secure Multicast over IPv6 Wireless Networks
Directory of Open Access Journals (Sweden)
Siddiqi Mohammad Umar
2006-01-01
Full Text Available Multicasting is an efficient method for transmission and routing of packets to multiple destinations using fewer network resources. Along with widespread deployment of wireless networks, secure multicast over wireless networks is an important and challenging goal. In this paper, we extend the scope of a recent new key distribution scheme to a security framework that offers a novel solution for secure multicast over IPv6 wireless networks. Our key management framework includes two scenarios for securely distributing the group key and rekey messages for joining and leaving a mobile host in secure multicast group. In addition, we perform the security analysis and provide performance comparisons between our approach and two recently published scenarios. The benefits of our proposed techniques are that they minimize the number of transmissions required to rekey the multicast group and impose minimal storage requirements on the multicast group. In addition, our proposed schemes are also very desirable from the viewpoint of transmission bandwidth savings since an efficient rekeying mechanism is provided for membership changes and they significantly reduce the required bandwidth due to key updating in mobile networks. Moreover, they achieve the security and scalability requirements in wireless networks.
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International Nuclear Information System (INIS)
2006-01-01
This document summarizes in a series of tables the key data of the petroleum industry and of the other energies for the year 2006. Data of the two previous years are given for comparison: 1 - petroleum, France: exploration, reserves, production, transports (tankers, pipelines, crude and refined products), storage capacities, status of resources and uses, foreign trade (imports, prices, exports), refining (capacities, facilities), evolution of supplies, automotive fuels consumption; 2 - energies, France: production, consumption and trade data for coal, natural gas, electricity; total production and consumption of primary energy; consumption per sector of use; 3 - petroleum, world: crude production and reserves per geographical area, OPEC production, imports/exports and refining/consumption per geographical area, international quotation for crudes and refined products; 4 - energies, world: reserves, production and consumption data for coal, natural gas and electricity; uranium production and resources; total primary energy production and consumption per energy source and geographical area. (J.S.)
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International Nuclear Information System (INIS)
2005-01-01
This document summarizes in a series of tables the key data of the petroleum industry and of the other energies for the year 2005. Data of the two previous years are given for comparison: 1 - petroleum, France: exploration, reserves, production, transports (tankers, pipelines, crude and refined products), storage capacities, status of resources and uses, foreign trade (imports, prices, exports), refining (capacities, facilities), evolution of supplies, automotive fuels consumption; 2 - energies, France: production, consumption and trade data for coal, natural gas, electricity; total production and consumption of primary energy; consumption per sector of use; 3 - petroleum, world: crude production and reserves per geographical area, OPEC production, imports/exports and refining/consumption per geographical area, international quotation for crudes and refined products; 4 - energies, world: reserves, production and consumption data for coal, natural gas and electricity; uranium production and resources; total primary energy production and consumption per energy source and geographical area. (J.S.)
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Attigala, Lakshmi; De Silva, Nuwan I; Clark, Lynn G
2016-04-01
Programs that are user-friendly and freely available for developing Web-based interactive keys are scarce and most of the well-structured applications are relatively expensive. WEBiKEY was developed to enable researchers to easily develop their own Web-based interactive keys with fewer resources. A Web-based multiaccess identification tool (WEBiKEY) was developed that uses freely available Microsoft ASP.NET technologies and an SQL Server database for Windows-based hosting environments. WEBiKEY was tested for its usability with a sample data set, the temperate woody bamboo genus Kuruna (Poaceae). WEBiKEY is freely available to the public and can be used to develop Web-based interactive keys for any group of species. The interactive key we developed for Kuruna using WEBiKEY enables users to visually inspect characteristics of Kuruna and identify an unknown specimen as one of seven possible species in the genus.
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Decision Trajectories in Dementia Care Networks: Decisions and Related Key Events.
Groen-van de Ven, Leontine; Smits, Carolien; Oldewarris, Karen; Span, Marijke; Jukema, Jan; Eefsting, Jan; Vernooij-Dassen, Myrra
2017-10-01
This prospective multiperspective study provides insight into the decision trajectories of people with dementia by studying the decisions made and related key events. This study includes three waves of interviews, conducted between July 2010 and July 2012, with 113 purposefully selected respondents (people with beginning to advanced stages of dementia and their informal and professional caregivers) completed in 12 months (285 interviews). Our multilayered qualitative analysis consists of content analysis, timeline methods, and constant comparison. Four decision themes emerged-managing daily life, arranging support, community living, and preparing for the future. Eight key events delineate the decision trajectories of people with dementia. Decisions and key events differ between people with dementia living alone and living with a caregiver. Our study clarifies that decisions relate not only to the disease but to living with the dementia. Individual differences in decision content and sequence may effect shared decision-making and advance care planning.
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Manet key management via Mobile Ficlke Key protocol (MFK ...
African Journals Online (AJOL)
Manet key management via Mobile Ficlke Key protocol (MFK) ... Journal of Fundamental and Applied Sciences. Journal Home · ABOUT THIS JOURNAL ... No Abstract. Keywords: MANET; key management scheme; simulation environment ...
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Implementation of the Brazilian primary standard for x-rays
International Nuclear Information System (INIS)
Peixoto, J.G.P.; Almeida, C.E.V. de
2002-01-01
In the field of ionizing radiation metrology, a primary standard of a given physical quantity is essentially an experimental set-up which allows one to attribute a numerical value to a particular sample of that quantity in terms of a unit given by an abstract definition. The absolute measurement of the radiation quantity air kerma, is performed with a free-air ionization chamber. A great deal of research to determine the absolute measurement resulted in different designs for primary standard free-air ionization chambers such as cilindrics or plane parallel chambers. The implementation of primary standard dosimetry with free-air ionization chambers is limited to the National Metrology Institutes - NMIs. Since 1975, the Bureau International des Poids et Mesures - BIPM has been conducting comparisons of NMIs primary free-air standard chambers in the medium energy x-rays range. These comparisons are carried out indirectly through the calibration at both the BIPM and at the NMI of one or more transfer ionization chambers at a series of four reference radiation qualities. The scientific work programme of the National Laboratory for Ionizing Radiation Metrology - LNMRI of the Institute of Radioprotection and Dosimetry - IRD, which belongs to the National Commission of Nuclear Energy - CNEN, includes the establishment of a primary standard for x-rays of medium energy x-ray range. This activity is justified by the demand to calibrate periodically Brazilian network of the secondary standards without losing quality of the measurement. The LNMRI decided to implement four reference radiation qualities establishing the use of a transfer chamber calibrated at BIPM. The LNMRI decided to implement the primary standard dosimetry using a free-air ionization chamber with variable volume, made by Victoreen, model 480. Parameters related to the measurement of the quantity air kerma were evaluated, such as: air absorption, scattering inside the ionization chamber, saturation, beam
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International Nuclear Information System (INIS)
Wang Yang; Bao Wan-Su; Li Hong-Wei; Zhou Chun; Li Yuan
2014-01-01
Similar to device-independent quantum key distribution (DI-QKD), semi-device-independent quantum key distribution (SDI-QKD) provides secure key distribution without any assumptions about the internal workings of the QKD devices. The only assumption is that the dimension of the Hilbert space is bounded. But SDI-QKD can be implemented in a one-way prepare-and-measure configuration without entanglement compared with DI-QKD. We propose a practical SDI-QKD protocol with four preparation states and three measurement bases by considering the maximal violation of dimension witnesses and specific processes of a QKD protocol. Moreover, we prove the security of the SDI-QKD protocol against collective attacks based on the min-entropy and dimension witnesses. We also show a comparison of the secret key rate between the SDI-QKD protocol and the standard QKD. (general)
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The Language of Comparisons: Communicating about Percentages
Directory of Open Access Journals (Sweden)
Jessica Polito
2014-01-01
Full Text Available While comparisons between percentages or rates appear frequently in journalism and advertising, and are an essential component of quantitative writing, many students fail to understand precisely what percentages mean, and lack fluency with the language used for comparisons. After reviewing evidence demonstrating this weakness, this experience-based perspective lays out a framework for teaching the language of comparisons in a structured way, and illustrates it with several authentic examples that exemplify mistaken or misleading uses of such numbers. The framework includes three common types of erroneous or misleading quantitative writing: the missing comparison, where a key number is omitted; the apples-to-pineapples comparison, where two subtly incomparable rates are presented; and the implied fallacy, where an invalid quantitative conclusion is left to the reader to infer.
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Absolute 22Na radioactivity measurement by gamma efficiency variation of 4πβ-γ coincidence method
International Nuclear Information System (INIS)
Hino, Yoshio; Kawada, Yasusi.
1994-01-01
The absolute radioactivity of 22 Na was obtained by gamma efficiency variation of 4πβ-γ coincidence method. Some other previous techniques, such as sum peak gate method based on the positron emission rate, relative measurement with calibrated ionization chambers, and gamma spectrometry with a HPGe detector, were also tried to ensure the present result. The results of these methods were in reasonable agreement with the present absolute measurement. The assayed source solution of this experiment was transferred to NBS type ampoules, and sealed ampoules were sent to the SIR (International Reference System) in BIPM, Taiwan and Indonesia for the international comparison. (author)
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Synthesis, characterization, and reactivity of a uranium(VI) carbene imido oxo complex
Energy Technology Data Exchange (ETDEWEB)
Lu, Erli; Cooper, Oliver J.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [Nottingham Univ. (United Kingdom). School of Chemistry; Tuna, Floriana; McInnes, Eric J.L. [Manchester Univ. (United Kingdom). School of Chemistry and Photon Science Inst.
2014-06-23
We report the uranium(VI) carbene imido oxo complex [U(BIPM{sup TMS})(NMes)(O)(DMAP){sub 2}] (5, BIPM{sup TMS}=C(PPh{sub 2}NSiMe{sub 3}){sub 2}; Mes=2,4,6-Me{sub 3}C{sub 6}H{sub 2}; DMAP=4-(dimethylamino)pyridine) which exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups. This complex was prepared by incorporation of carbene, imido, and then oxo groups at the uranium center by salt elimination, protonolysis, and two-electron oxidation, respectively. The oxo and imido groups adopt axial positions in a T-shaped motif with respect to the carbene, which is consistent with an inverse trans-influence. Complex 5 reacts with tert-butylisocyanate at the imido rather than carbene group to afford the uranyl(VI) carbene complex [U(BIPM{sup TMS})(O){sub 2}(DMAP){sub 2}] (6).
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Energy Technology Data Exchange (ETDEWEB)
Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth
2016-11-29
Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.
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Comparison as a Universal Learning Action
Merkulova, T. V.
2016-01-01
This article explores "comparison" as a universal metasubject learning action, a key curricular element envisaged by the Russian Federal State Educational Standards. Representing the modern learner's fundamental pragmatic skill embedding such core capacities as information processing, critical thinking, robust decision-making, and…
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International Nuclear Information System (INIS)
1982-01-01
Section I (Rayons X et #betta#, electrons) of the Comite Consultatif pour les Etalons de Mesure des Rayonnements Ionisants held its sixth meeting in June 1981. The work carried out recently in various laboratories represented at the meeting is contained in a series of Progress Reports. Several international comparisons of exposure standards performed at BIPM between 5 keV and 1.2 MeV were presented and the question of exposure measurements at protection-level exposure rates was raised. The work of the three existing Working Parties was discussed at length: comparison of Fricke chemical dosimetry systems, conversion of exposure to absorbed dose in water, conversion of graphite absorbed dose into water absorbed dose. A recommendation was made concerning the possibility of expressing in terms of air kerma or water kerma calibrations made in terms of exposure [fr
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La progettazione di nuovi spazi educativi per l’infanzia: da Ellen Key a Maria Montessori
Directory of Open Access Journals (Sweden)
Tiziana Pironi
2011-11-01
Full Text Available The essay presents a comparison between the thought of Ellen Key and that of Maria Montessori. Changes that involved the role of women, caught in its interdependence with the development of new educational practices, were the center of the theoretical contribution of Ellen Key. Maria Montessori believed that only women work outside the home would guarantee the economic independence necessary to form a union on sentiment rather than on utilitarian calculations and therefore she did not seem to share the concerns of the Key on an increasingly massive female entry into the world of work. The paper offers an updated reflection on the work of two scholars of education.
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A new approach to the determination of air kerma using primary-standard cavity ionization chambers
International Nuclear Information System (INIS)
Burns, D T
2006-01-01
A consistent formalism is presented using Monte Carlo calculations to determine the reference air kerma from the measured energy deposition in a primary-standard cavity ionization chamber. A global approach avoiding the use of cavity ionization theory is discussed and its limitations shown in relation to the use of the recommended value for W. The role of charged-particle equilibrium is outlined and the consequent requirements placed on the calculations are detailed. Values for correction factors are presented for the BIPM air-kerma standard for 60 Co, making use of the Monte Carlo code PENELOPE, a detailed geometrical model of the BIPM 60 Co source and event-by-event electron transport. While the wall correction factor k wall = 1.0012(2) is somewhat lower than the existing value, the axial non-uniformity correction k an = 1.0027(3) is significantly higher. The use of a point source in the evaluation of k an is discussed. A comparison is made of the calculated dose ratio with the Bragg-Gray and Spencer-Attix stopping-power ratios, the results indicating a preference for the Bragg-Gray approach in this particular case. A change to the recommended value for W of up to 2 parts in 10 3 is discussed. The uncertainties arising from the geometrical models, the use of phase-space files, the radiation transport algorithms and the underlying radiation interaction coefficients are estimated
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Designing key-dependent chaotic S-box with larger key space
International Nuclear Information System (INIS)
Yin Ruming; Yuan Jian; Wang Jian; Shan Xiuming; Wang Xiqin
2009-01-01
The construction of cryptographically strong substitution boxes (S-boxes) is an important concern in designing secure cryptosystems. The key-dependent S-boxes designed using chaotic maps have received increasing attention in recent years. However, the key space of such S-boxes does not seem to be sufficiently large due to the limited parameter range of discretized chaotic maps. In this paper, we propose a new key-dependent S-box based on the iteration of continuous chaotic maps. We explore the continuous-valued state space of chaotic systems, and devise the discrete mapping between the input and the output of the S-box. A key-dependent S-box is constructed with the logistic map in this paper. We show that its key space could be much larger than the current key-dependent chaotic S-boxes.
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Energy Technology Data Exchange (ETDEWEB)
Dunigan, T.; Cao, C.
1997-08-01
This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.
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MoKey: A versatile exergame creator for everyday usage.
Eckert, Martina; López, Marcos; Lázaro, Carlos; Meneses, Juan
2017-11-27
Currently, virtual applications for physical exercises are highly appreciated as rehabilitation instruments. This article presents a middleware called "MoKey" (Motion Keyboard), which converts standard off-the-shelf software into exergames (exercise games). A configurable set of gestures, captured by a motion capture camera, is translated into the key strokes required by the chosen software. The present study assesses the tool regarding usability and viability on a heterogeneous group of 11 participants, aged 5 to 51, with moderate to severe disabilities, and mostly bound to a wheelchair. In comparison with FAAST (The Flexible Action and Articulated Skeleton Toolkit), MoKey achieved better results in terms of ease of use and computational load. The viability as an exergame creator tool was proven with help of four applications (PowerPoint®, e-book reader, Skype®, and Tetris). Success rates of up to 91% have been achieved, subjective perception was rated with 4.5 points (from 0-5). The middleware provides increased motivation due to the use of favorite software and the advantage of exploiting it for exercise. Used together with communication software or online games, social inclusion can be stimulated. The therapists can employ the tool to monitor the correctness and progress of the exercises.
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Robust Public Key Cryptography — A New Cryptosystem Surviving Private Key Compromise
Shaik, Cheman
A weakness of the present-day public key cryptosystems is that these cryptosystems do not survive private-key compromise attacks resulting from an internal breach of trust. In a competitive business environment, private key compromise is a common incident that voids the strength of public key cryptosystems such as RSA and ECC. Bribing corporate employees to disclose their secret keys and inadvertently disclosing secret information are among a plethora of practical attacks that occur at the implementation level. Once a breach of trust takes place and subsequently the private key is revealed, any public key cryptosystem fails to secure electronic data in Internet communications. The revealed key may be used by an attacker to decipher the intercepted data at an intermediary router. This weakness of public key cryptography calls for an additional security measure that enables encryptions to survive private key compromise attacks.
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Conceptualizing childhood health problems using survey data: a comparison of key indicators
Directory of Open Access Journals (Sweden)
Miller Anton R
2007-12-01
Full Text Available Abstract Background Many definitions are being used to conceptualize child health problems. With survey data, commonly used indicators for identifying children with health problems have included chronic condition checklists, measures of activity limitations, elevated service use, and health utility thresholds. This study compares these different indicators in terms of the prevalence rates elicited, and in terms of how the subgroups identified differ. Methods Secondary data analyses used data from the National Longitudinal Survey of Children and Youth, which surveyed a nationally representative sample of Canadian children (n = 13,790. Descriptive analyses compared healthy children to those with health problems, as classified by any of the key indicators. Additional analyses examined differences between subgroups of children captured by a single indicator and those described as having health problems by multiple indicators. Results This study demonstrates that children captured by any of the indicators had poorer health than healthy children, despite the fact that over half the sample (52.2% was characterized as having a health problem by at least one indicator. Rates of child ill health differed by indicator; 5.6% had an activity limitation, 9.2% exhibited a severe health difficulty, 31.7% reported a chronic condition, and 36.6% had elevated service use. Further, the four key indicators captured different types of children. Indicator groupings differed on child and socio-demographic factors. Compared to children identified by more than one indicator, those identified only by the severe health difficulty indicator displayed more cognitive problems (p Conclusion We provide information useful to researchers when selecting indicators from survey data to identify children with health problems. Researchers and policy makers need to be aware of the impact of such definitions on prevalence rates as well as on the composition of children classified as
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Final report on RMO key comparison EURAMET.L-K6: CMM 2-D artifact: ball plate
DEFF Research Database (Denmark)
Jusko, O.; Banreti, E.; Bergmans, R.
2013-01-01
An industrial standard steel ball plate of dimension 420 mm with 25 ceramic balls in a 5 × 5 arrangement was circulated among 12 European NMIs. The measurement task was the calibration of the centres of the 25 balls. The measurements were conducted between 2004 and 2006. One NMI withdrew from...... the comparison. The other 11 NMIs measured the ball plate and delivered data. The artifact was found to be stable during the duration of the comparison. For the analysis both the deviations from the KCRV and the En numbers were calculated. Most results agreed very well within the claimed uncertainty. A few...... for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA)....
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Arshad, Hamed; Nikooghadam, Morteza
2014-12-01
Nowadays, with comprehensive employment of the internet, healthcare delivery services is provided remotely by telecare medicine information systems (TMISs). A secure mechanism for authentication and key agreement is one of the most important security requirements for TMISs. Recently, Tan proposed a user anonymity preserving three-factor authentication scheme for TMIS. The present paper shows that Tan's scheme is vulnerable to replay attacks and Denial-of-Service attacks. In order to overcome these security flaws, a new and efficient three-factor anonymous authentication and key agreement scheme for TMIS is proposed. Security and performance analysis shows superiority of the proposed scheme in comparison with previously proposed schemes that are related to security of TMISs.
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Synthesis, characterization, and reactivity of a uranium(VI) carbene imido oxo complex
Energy Technology Data Exchange (ETDEWEB)
Lu, Erli; Cooper, Oliver J.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [School of Chemistry, University of Nottingham (United Kingdom); Tuna, Floriana; McInnes, Eric J.L. [School of Chemistry and Photon Science Institute, University of Manchester (United Kingdom)
2014-06-23
We report the uranium(VI) carbene imido oxo complex [U(BIPM{sup TMS})(NMes)(O)(DMAP){sub 2}] (5, BIPM{sup TMS}=C(PPh{sub 2}NSiMe{sub 3}){sub 2}; Mes=2,4,6-Me{sub 3}C{sub 6}H{sub 2}; DMAP=4-(dimethylamino)pyridine) which exhibits the unprecedented arrangement of three formal multiply bonded ligands to one metal center where the coordinated heteroatoms derive from different element groups. This complex was prepared by incorporation of carbene, imido, and then oxo groups at the uranium center by salt elimination, protonolysis, and two-electron oxidation, respectively. The oxo and imido groups adopt axial positions in a T-shaped motif with respect to the carbene, which is consistent with an inverse trans-influence. Complex 5 reacts with tert-butylisocyanate at the imido rather than carbene group to afford the uranyl(VI) carbene complex [U(BIPM{sup TMS})(O){sub 2}(DMAP){sub 2}] (6). (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
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Key indicators for organizational performance measurement
Directory of Open Access Journals (Sweden)
Firoozeh Haddadi
2014-09-01
Full Text Available Each organization for assessing the amount of utility and desirability of their activities, especially in complex and dynamic environments, requires determining and ranking the vital performance indicators. Indicators provide essential links among strategy, execution and ultimate value creation. The aim of this paper is to develop a framework, which identifies and prioritizes Key Performance Indicators (KPIs that a company should focus on them to define and measure progress towards organizational objectives. For this purpose, an applied research was conducted in 2013 in an Iranian telecommunication company. We first determined the objectives of the company with respect to four perspectives of BSC (Balanced Scorecard framework. Next, performance indicators were listed and paired wise comparisons were accomplished by company's high-ranked employees through standard Analytic Hierarchy Process (AHP questionnaires. This helped us establish the weight of each indicator and to rank them, accordingly.
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Two-Dimensional Key Table-Based Group Key Distribution in Advanced Metering Infrastructure
Directory of Open Access Journals (Sweden)
Woong Go
2014-01-01
Full Text Available A smart grid provides two-way communication by using the information and communication technology. In order to establish two-way communication, the advanced metering infrastructure (AMI is used in the smart grid as the core infrastructure. This infrastructure consists of smart meters, data collection units, maintenance data management systems, and so on. However, potential security problems of the AMI increase owing to the application of the public network. This is because the transmitted information is electricity consumption data for charging. Thus, in order to establish a secure connection to transmit electricity consumption data, encryption is necessary, for which key distribution is required. Further, a group key is more efficient than a pairwise key in the hierarchical structure of the AMI. Therefore, we propose a group key distribution scheme using a two-dimensional key table through the analysis result of the sensor network group key distribution scheme. The proposed scheme has three phases: group key predistribution, selection of group key generation element, and generation of group key.
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Key management of the double random-phase-encoding method using public-key encryption
Saini, Nirmala; Sinha, Aloka
2010-03-01
Public-key encryption has been used to encode the key of the encryption process. In the proposed technique, an input image has been encrypted by using the double random-phase-encoding method using extended fractional Fourier transform. The key of the encryption process have been encoded by using the Rivest-Shamir-Adelman (RSA) public-key encryption algorithm. The encoded key has then been transmitted to the receiver side along with the encrypted image. In the decryption process, first the encoded key has been decrypted using the secret key and then the encrypted image has been decrypted by using the retrieved key parameters. The proposed technique has advantage over double random-phase-encoding method because the problem associated with the transmission of the key has been eliminated by using public-key encryption. Computer simulation has been carried out to validate the proposed technique.
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Security of Color Image Data Designed by Public-Key Cryptosystem Associated with 2D-DWT
Mishra, D. C.; Sharma, R. K.; Kumar, Manish; Kumar, Kuldeep
2014-08-01
In present times the security of image data is a major issue. So, we have proposed a novel technique for security of color image data by public-key cryptosystem or asymmetric cryptosystem. In this technique, we have developed security of color image data using RSA (Rivest-Shamir-Adleman) cryptosystem with two-dimensional discrete wavelet transform (2D-DWT). Earlier proposed schemes for security of color images designed on the basis of keys, but this approach provides security of color images with the help of keys and correct arrangement of RSA parameters. If the attacker knows about exact keys, but has no information of exact arrangement of RSA parameters, then the original information cannot be recovered from the encrypted data. Computer simulation based on standard example is critically examining the behavior of the proposed technique. Security analysis and a detailed comparison between earlier developed schemes for security of color images and proposed technique are also mentioned for the robustness of the cryptosystem.
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Antennae hold a key to Varroa-sensitive hygiene behaviour in honey bees
Mondet, Fanny; Alaux, C?dric; Severac, Dany; Rohmer, Marine; Mercer, Alison R.; Le Conte, Yves
2015-01-01
In honey bees, Varroa sensitive hygiene (VSH) behaviour, which involves the detection and removal of brood parasitised by the mite Varroa destructor, can actively participate in the survival of colonies facing Varroa outbreaks. This study investigated the mechanisms of VSH behaviour, by comparing the antennal transcriptomes of bees that do and do not perform VSH behaviour. Results indicate that antennae likely play a key role in the expression of VSH behaviour. Comparisons with the antennal t...
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Breaking chaotic shift key communication via adaptive key identification
International Nuclear Information System (INIS)
Ren Haipeng; Han Chongzhao; Liu Ding
2008-01-01
This paper proposes an adaptive parameter identification method for breaking chaotic shift key communication from the transmitted signal in public channel. The sensitive dependence property of chaos on parameter mismatch is used for chaos adaptive synchronization and parameter identification. An index function about the synchronization error is defined and conjugate gradient method is used to minimize the index function and to search the transmitter's parameter (key). By using proposed method, secure key is recovered from transmitted signal generated by low dimensional chaos and hyper chaos switching communication. Multi-parameters can also be identified from the transmitted signal with noise
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Modular Connector Keying Concept
Ishman, Scott; Dukes, Scott; Warnica, Gary; Conrad, Guy; Senigla, Steven
2013-01-01
For panel-mount-type connectors, keying is usually "built-in" to the connector body, necessitating different part numbers for each key arrangement. This is costly for jobs that require small quantities. This invention was driven to provide a cost savings and to reduce documentation of individual parts. The keys are removable and configurable in up to 16 combinations. Since the key parts are separate from the connector body, a common design can be used for the plug, receptacle, and key parts. The keying can then be set at the next higher assembly.
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Achieving organizational alignment - key to survival
International Nuclear Information System (INIS)
Allison, J.T.
1997-01-01
The restructuring of the gas and electric industry and the impact of the restructuring on organizational survival was discussed. The forces driving the trend to restructuring are commoditization of energy, demanding, fragmented customer needs, diverse, transforming technologies, and intense competition. Realigning a company to the changing marketplace is the key to survival with customers, financial markets, and with competition. This paper presented a reality-based, results oriented approach to strategy consulting. Four case studies - Telco, Natural gas holding company, Combined utility, and Duke/Louis Dreyfus - were used for illustrating different problems and different approaches to restructuring. In each case a comparison was made between the company's old organization in the early 1990's, the driving forces responsible for the change and the company's new organization in the mid 1990's. In all cases the predominance of the customer focus is quite apparent, as is the clear lines of demarcation between regulated and unregulated activities. The underlying theme in all restructuring is agility and striving for flexibility
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Flow hydrodynamics near inlet key of Piano Key Weir (PKW)
Indian Academy of Sciences (India)
Department of Water Resources Development and Management, Indian Institute ... on the hydrodynamic performance near inlet key of Piano Key Weir (PKW). ... nature of flows is clearly understood with the help of advanced instrumentation.
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Key to good fit: body measurement problems specific to key ...
African Journals Online (AJOL)
Key to good fit: body measurement problems specific to key dimensions. ... to explore and describe the problems that the South African Clothing Industry currently ... A postal survey was conducted among South African apparel and footwear ...
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Operating Reserves and Wind Power Integration: An International Comparison; Preprint
Energy Technology Data Exchange (ETDEWEB)
Milligan, M.; Donohoo, P.; Lew, D.; Ela, E.; Kirby, B.; Holttinen, H.; Lannoye, E.; Flynn, D.; O' Malley, M.; Miller, N.; Eriksen, P. B.; Gottig, A.; Rawn, B.; Gibescu, M.; Lazaro, E. G.; Robitaille, A.; Kamwa, I.
2010-10-01
This paper provides a high-level international comparison of methods and key results from both operating practice and integration analysis, based on an informal International Energy Agency Task 25: Large-scale Wind Integration.
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AUDIO CRYPTANALYSIS- AN APPLICATION OF SYMMETRIC KEY CRYPTOGRAPHY AND AUDIO STEGANOGRAPHY
Directory of Open Access Journals (Sweden)
Smita Paira
2016-09-01
Full Text Available In the recent trend of network and technology, “Cryptography” and “Steganography” have emerged out as the essential elements of providing network security. Although Cryptography plays a major role in the fabrication and modification of the secret message into an encrypted version yet it has certain drawbacks. Steganography is the art that meets one of the basic limitations of Cryptography. In this paper, a new algorithm has been proposed based on both Symmetric Key Cryptography and Audio Steganography. The combination of a randomly generated Symmetric Key along with LSB technique of Audio Steganography sends a secret message unrecognizable through an insecure medium. The Stego File generated is almost lossless giving a 100 percent recovery of the original message. This paper also presents a detailed experimental analysis of the algorithm with a brief comparison with other existing algorithms and a future scope. The experimental verification and security issues are promising.
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Experimental investigation of quantum key distribution with position and momentum of photon pairs
International Nuclear Information System (INIS)
Almeida, M.P.; Walborn, S.P.; Souto Ribeiro, P.H.
2005-01-01
We investigate the utility of Einstein-Podolsky-Rosen correlations of the position and momentum of photon pairs from parametric down-conversion in the implementation of a secure quantum key distribution protocol. We show that security is guaranteed by the entanglement between down-converted pairs, and can be checked by either direct comparison of Alice and Bob's measurement results or evaluation of an inequality of the sort proposed by Mancini et al. [Phys. Rev. Lett. 88, 120401 (2002)
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Federal Laboratory Consortium — FUNCTION: Provides a secure environment to research and develop advanced electronic key management and networked key distribution technologies for the Navy and DoD....
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Locks and Keys Service
2002-01-01
The Locks and Keys service (ST/FM) will move from building 55 to building 570 from the 2nd August to the 9th August 2002 included. During this period the service will be closed. Only in case of extreme urgency please call the 164550. Starting from Monday, 12th August, the Locks and Keys Service will continue to follow the activities related to office keys (keys and locks) and will provide the keys for furniture. The service is open from 8h30 to 12h00 and from 13h00 to 17h30. We remind you that your divisional correspondents can help you in the execution of the procedures. We thank you for your comprehension and we remain at your service to help you in solving all the matters related to keys for offices and furniture. Locks and Keys Service - ST Division - FM Group
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Intake of Key Chronic Disease–Related Nutrients among Baby Boomers
King, Dana E.; Xiang, Jun; Brown, Alexander
2014-01-01
Objectives The dietary habits of baby boomers (people born between 1946 and 1964) undoubtedly will have a substantial impact on their future health; however, dietary information regarding the intake of key chronic disease–related nutrients is lacking for this generation. The objective of this study was to compare the dietary intake of key chronic disease–related nutrients of the baby boomer generation with the previous generation of middle-aged adults. Methods National cross-sectional study comparison analyzing data from the National Health and Nutrition Examination Survey (NHANES) including NHANES III (1988–1994) and the NHANES for 2007–2010, focused on adult respondents ages 46 to 64 years who were not institutionalized at the time of each survey. The two cohorts were compared with regard to dietary intake of key nutritional components. The main outcome measures were intake of total calories, sodium, cholesterol, fat, fruits, vegetables, vitamin C, water, and fiber. Results The baby boomers’ average daily intake of nutrients exceeded that of the previous generation of middle-aged adults for total calories (2118/1999), total fat (82/76 g), sodium (3513/3291 mg), and cholesterol (294/262 g; all P generation (P baby boomers compared with the previous generation of middle-aged adults. These findings are indicative of a diet that may contribute to increased rates of chronic disease among individuals in this age group. PMID:24945165
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Intake of key chronic disease-related nutrients among baby boomers.
King, Dana E; Xiang, Jun; Brown, Alexander
2014-06-01
The dietary habits of baby boomers (people born between 1946 and 1964) undoubtedly will have a substantial impact on their future health; however, dietary information regarding the intake of key chronic disease-related nutrients is lacking for this generation. The objective of this study was to compare the dietary intake of key chronic disease-related nutrients of the baby boomer generation with the previous generation of middle-aged adults. National cross-sectional study comparison analyzing data from the National Health and Nutrition Examination Survey (NHANES) including NHANES III (1988-1994) and the NHANES for 2007-2010, focused on adult respondents ages 46 to 64 years who were not institutionalized at the time of each survey. The two cohorts were compared with regard to dietary intake of key nutritional components. The main outcome measures were intake of total calories, sodium, cholesterol, fat, fruits, vegetables, vitamin C, water, and fiber. The baby boomers' average daily intake of nutrients exceeded that of the previous generation of middle-aged adults for total calories (2118/1999), total fat (82/76 g), sodium (3513/3291 mg), and cholesterol (294/262 g; all P generation (P baby boomers compared with the previous generation of middle-aged adults. These findings are indicative of a diet that may contribute to increased rates of chronic disease among individuals in this age group.
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Comparison of strategies for model predictive control for home heating in future energy systems
DEFF Research Database (Denmark)
Vogler-Finck, Pierre Jacques Camille; Popovski, Petar; Wisniewski, Rafal
2017-01-01
Model predictive control is seen as one of the key future enabler in increasing energy efficiency in buildings. This paper presents a comparison of the performance of the control for different formulations of the objective function. This comparison is made in a simulation study on a single buildi...
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International Nuclear Information System (INIS)
Diamanti, Eleni; Takesue, Hiroki; Honjo, Toshimori; Inoue, Kyo; Yamamoto, Yoshihisa
2005-01-01
We compare the performance of various quantum-key-distribution (QKD) systems using a single-photon detector, which combines frequency up-conversion in a periodically poled lithium niobate waveguide and a silicon avalanche photodiode (APD). The comparison is based on the secure communication rate as a function of distance for three QKD protocols: the Bennett-Brassard 1984, the Bennett-Brassard-Mermin 1992, and the coherent differential-phase-shift keying protocols. We show that the up-conversion detector allows for higher communication rates and longer communication distances than the commonly used InGaAs/InP APD for all three QKD protocols
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International Nuclear Information System (INIS)
1997-01-01
In this book can be found all the useful information on the French industry key technologies of the years 2000-2005. 136 technologies at the junction of the science advances and of the markets expectations are divided into 9 sectors. Among them, only 4 are interesting here: the environment, the transports, the materials and the energy. In 1995, the secretary's office of State for industry has published a first synthesis book on these key technologies. This 1997 new key technologies book extends and completes the initial study. For each key technology, an encyclopedic sheet is given. Each sheet combines thus some exact and practical information on: advance state of the technology, market characteristics, development forecasts, occupation and involved sectors, technology acquisition cost, research programs but also contacts of the main concerned efficiency poles. (O.M.)
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Morphological Comparison of U3O8 Ore Concentrates from Canada Key Lake and Namibia Sources
Energy Technology Data Exchange (ETDEWEB)
Schwartz, Daniel S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Patrick Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-03-11
Uranium ore concentrates from two different sources were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The ore powders are referred to as Namibia (id. no. 90036, LIMS id. no. 18775) and Canada Key Lake (id. no. 90019, LIMS id. no. 18774). Earlier work identified the ores as the U₃O₈ phase of uranium oxide using x-ray diffraction. Both sets of powders were in the form of dark brown to black powder fines. However, the Canada Key Lake concentrates contained larger chunks of material on the millimeter scale that were easily visible to the unaided eye. The powders were mounted for SEM examination by hand dispersing a small amount onto conductive sticky tape. Two types of applicators were used and compared: a fine-tipped spatula and a foam-tipped applicator. The sticky tape was on a standard SEM “tee” mount, which was tapped to remove loose contamination before being inserted into the SEM.
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A Key Pre-Distribution Scheme Based on µ-PBIBD for Enhancing Resilience in Wireless Sensor Networks.
Yuan, Qi; Ma, Chunguang; Yu, Haitao; Bian, Xuefen
2018-05-12
Many key pre-distribution (KPD) schemes based on combinatorial design were proposed for secure communication of wireless sensor networks (WSNs). Due to complexity of constructing the combinatorial design, it is infeasible to generate key rings using the corresponding combinatorial design in large scale deployment of WSNs. In this paper, we present a definition of new combinatorial design, termed “µ-partially balanced incomplete block design (µ-PBIBD)”, which is a refinement of partially balanced incomplete block design (PBIBD), and then describe a 2-D construction of µ-PBIBD which is mapped to KPD in WSNs. Our approach is of simple construction which provides a strong key connectivity and a poor network resilience. To improve the network resilience of KPD based on 2-D µ-PBIBD, we propose a KPD scheme based on 3-D Ex-µ-PBIBD which is a construction of µ-PBIBD from 2-D space to 3-D space. Ex-µ-PBIBD KPD scheme improves network scalability and resilience while has better key connectivity. Theoretical analysis and comparison with the related schemes show that key pre-distribution scheme based on Ex-µ-PBIBD provides high network resilience and better key scalability, while it achieves a trade-off between network resilience and network connectivity.
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Tapson, Frank
1996-01-01
Describes public key cryptography, also known as RSA, which is a system using two keys, one used to put a message into cipher and another used to decipher the message. Presents examples using small prime numbers. (MKR)
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DEFF Research Database (Denmark)
Dellson, P; Nilbert, M; Bendahl, P-O
2011-01-01
for improvements, 21 key issues were defined and validated through a questionnaire in an independent group of breast cancer patient advocates. Clear messages, emotionally neutral expressions, careful descriptions of side effects, clear comparisons between different treatment alternatives and information about......Clinical trials are crucial to improve cancer treatment but recruitment is difficult. Optimised patient information has been recognised as a key issue. In line with the increasing focus on patients' perspectives in health care, we aimed to study patients' opinions about the written information used...... the possibility to discontinue treatment were perceived as the most important issues. Patients' views of the information in clinical trials provide new insights and identify key issues to consider in optimising future written information and may improve recruitment to clinical cancer trials....
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Lin, Tsung-Hung; Tsung, Chen-Kun; Lee, Tian-Fu; Wang, Zeng-Bo
2017-12-03
The security is a critical issue for business purposes. For example, the cloud meeting must consider strong security to maintain the communication privacy. Considering the scenario with cloud meeting, we apply extended chaotic map to present passwordless group authentication key agreement, termed as Passwordless Group Authentication Key Agreement (PL-GAKA). PL-GAKA improves the computation efficiency for the simple group password-based authenticated key agreement (SGPAKE) proposed by Lee et al. in terms of computing the session key. Since the extended chaotic map has equivalent security level to the Diffie-Hellman key exchange scheme applied by SGPAKE, the security of PL-GAKA is not sacrificed when improving the computation efficiency. Moreover, PL-GAKA is a passwordless scheme, so the password maintenance is not necessary. Short-term authentication is considered, hence the communication security is stronger than other protocols by dynamically generating session key in each cloud meeting. In our analysis, we first prove that each meeting member can get the correct information during the meeting. We analyze common security issues for the proposed PL-GAKA in terms of session key security, mutual authentication, perfect forward security, and data integrity. Moreover, we also demonstrate that communicating in PL-GAKA is secure when suffering replay attacks, impersonation attacks, privileged insider attacks, and stolen-verifier attacks. Eventually, an overall comparison is given to show the performance between PL-GAKA, SGPAKE and related solutions.
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Tănase Alin-Eliodor
2014-01-01
This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.
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Emergency medical services key performance measurement in Asian cities.
Rahman, Nik Hisamuddin; Tanaka, Hideharu; Shin, Sang Do; Ng, Yih Yng; Piyasuwankul, Thammapad; Lin, Chih-Hao; Ong, Marcus Eng Hock
2015-01-01
One of the key principles in the recommended standards is that emergency medical service (EMS) providers should continuously monitor the quality and safety of their services. This requires service providers to implement performance monitoring using appropriate and relevant measures including key performance indicators. In Asia, EMS systems are at different developmental phases and maturity. This will create difficultly in benchmarking or assessing the quality of EMS performance across the region. An attempt was made to compare the EMS performance index based on the structure, process, and outcome analysis. The data was collected from the Pan-Asian Resuscitation Outcome Study (PAROS) data among few Asian cities, namely, Tokyo, Osaka, Singapore, Bangkok, Kuala Lumpur, Taipei, and Seoul. The parameters of inclusions were broadly divided into structure, process, and outcome measurements. The data was collected by the site investigators from each city and keyed into the electronic web-based data form which is secured strictly by username and passwords. Generally, there seems to be a more uniformity for EMS performance parameters among the more developed EMS systems. The major problem with the EMS agencies in the cities of developing countries like Bangkok and Kuala Lumpur is inadequate or unavailable data pertaining to EMS performance. There is non-uniformity in the EMS performance measurement across the Asian cities. This creates difficulty for EMS performance index comparison and benchmarking. Hopefully, in the future, collaborative efforts such as the PAROS networking group will further enhance the standardization in EMS performance reporting across the region.
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A Survey of Public Key Infrastructure-Based Security for Mobile Communication Systems
Directory of Open Access Journals (Sweden)
Mohammed Ramadan
2016-08-01
Full Text Available Mobile communication security techniques are employed to guard the communication between the network entities. Mobile communication cellular systems have become one of the most important communication systems in recent times and are used by millions of people around the world. Since the 1990s, considerable efforts have been taken to improve both the communication and security features of the mobile communications systems. However, these improvements divide the mobile communications field into different generations according to the communication and security techniques such as A3, A5 and A8 algorithms for 2G-GSM cellular system, 3G-authentication and key agreement (AKA, evolved packet system-authentication and key agreement (EPS-AKA, and long term evolution-authentication and key agreement (LTE-AKA algorithms for 3rd generation partnership project (3GPP systems. Furthermore, these generations have many vulnerabilities, and huge security work is involved to solve such problems. Some of them are in the field of the public key cryptography (PKC which requires a high computational cost and more network flexibility to be achieved. As such, the public key infrastructure (PKI is more compatible with the modern generations due to the superior communications features. This paper surveys the latest proposed works on the security of GSM, CDMA, and LTE cellular systems using PKI. Firstly, we present the security issues for each generation of mobile communication systems, then we study and analyze the latest proposed schemes and give some comparisons. Finally, we introduce some new directions for the future scope. This paper classifies the mobile communication security schemes according to the techniques used for each cellular system and covers some of the PKI-based security techniques such as authentication, key agreement, and privacy preserving.
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Nonmarket economic user values of the Florida Keys/Key West
Vernon R. Leeworthy; J. Michael Bowker
1997-01-01
This report provides estimates of the nonmarket economic user values for recreating visitors to the Florida Keys/Key West that participated in natural resource-based activities. Results from estimated travel cost models are presented, including visitorâs responses to prices and estimated per person-trip user values. Annual user values are also calculated and presented...
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75 FR 17463 - Key West Bank, Key West, Florida; Notice of Appointment of Receiver
2010-04-06
... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Key West Bank, Key West, Florida; Notice... section 5(d)(2) of the Home Owners' Loan Act, the Office of Thrift Supervision has duly appointed the Federal Deposit Insurance Corporation as sole Receiver for Key West Bank, Key West, Florida, (OTS No...
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Fundamental study on the size and inter-key spacing of numeric keys for touch screen.
Harada, H; Katsuura, T; Kikuchi, Y
1996-12-01
The purpose of this study was to reveal the optimum size and inter-key spacing of numeric square keys for touch screens. Six male students (22-25 years old) and three female students (21-24 years old) volunteered as subjects for this experiment. Each subject took part in data entry tasks using numeric square keys of touch devices. The sizes of keys were 6, 12, 21, 30 and 39 mm and each the inter-key spacing was 0, 3, 6, 12 and 21 mm. Response times with key sizes of 6 and 12 mm were significantly slower than with key sizes of 21 and 30 mm (p touch screens should be more than 21 mm and optimum inter-key spacing should be from 3 to 6 mm. Optimum key size, however, must be selected with regard to the limitation of screen size.
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A New Quantum Key Distribution Scheme Based on Frequency and Time Coding
International Nuclear Information System (INIS)
Chang-Hua, Zhu; Chang-Xing, Pei; Dong-Xiao, Quan; Jing-Liang, Gao; Nan, Chen; Yun-Hui, Yi
2010-01-01
A new scheme of quantum key distribution (QKD) using frequency and time coding is proposed, in which the security is based on the frequency-time uncertainty relation. In this scheme, the binary information sequence is encoded randomly on either the central frequency or the time delay of the optical pulse at the sender. The central frequency of the single photon pulse is set as ω 1 for bit 0 and set as ω 2 for bit 1 when frequency coding is selected. However, the single photon pulse is not delayed for bit 0 and is delayed in τ for 1 when time coding is selected. At the receiver, either the frequency or the time delay of the pulse is measured randomly, and the final key is obtained after basis comparison, data reconciliation and privacy amplification. With the proposed method, the effect of the noise in the fiber channel and environment on the QKD system can be reduced effectively
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International Nuclear Information System (INIS)
Loureiro, Jamir dos Santos
2000-02-01
In this work is reported a methodology a methodology for pure beta and electron capture radionuclides standardization, suing liquid scintillation technique. In this sense the CIEMAT/NIST method, recently utilized by international laboratories, was implemented and the lack in the Laboratorio Nacional das Radiacoes Ionizantes - LNMRI, of the Comissao Nacional de Energia Nuclear - CNEN, for adequate methodology to standardize this kind if radionuclides was filled, fact that was not present with alpha and gamma radionuclides. The implementation procedure evaluation was provided by concentration activity determination of the following radionuclides: 14 C and 90 Sr, pure beta emitters; 55 Fe, electron capture decay; 204 Tl, electron capture and beta decay and 60 Co, beta-gamma emitter. In this way, a careful analysis of the implementation procedure with these radionuclides types, ranging on a broad energy spectral, was possible. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. Besides this intercomparisons, one was provided with a 204 Tl solution, utilized in the international comparison recently promoted by BIPM, and another one with a 60 C solution calibrated in LNMRI/CNEN previously by a relative calibration system, with a well type pressurized ionization chamber, and an absolute beta-gamma coincidence system, with a pill-box type proportional counter 4 π geometry, coupled with a scintillator system with a sodium iodide cristal of 4x4 inches. The comparisons among LNMRI/CNEN results and the reference values, showed a small deviation of 1,32% for 14 C, 0,40% for 60 Co, 1,12% for 55 Fe, 0,10% for 90 Sr and 0,73% for 204 Tl. For the BIPM solution the deviation was 0,46% and for 60 Co
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Energy Technology Data Exchange (ETDEWEB)
Loureiro, Jamir dos Santos
2000-02-01
In this work is reported a methodology a methodology for pure beta and electron capture radionuclides standardization, suing liquid scintillation technique. In this sense the CIEMAT/NIST method, recently utilized by international laboratories, was implemented and the lack in the Laboratorio Nacional das Radiacoes Ionizantes - LNMRI, of the Comissao Nacional de Energia Nuclear - CNEN, for adequate methodology to standardize this kind if radionuclides was filled, fact that was not present with alpha and gamma radionuclides. The implementation procedure evaluation was provided by concentration activity determination of the following radionuclides: {sup 14} C and {sup 90} Sr, pure beta emitters; {sup 55} Fe, electron capture decay; {sup 204} Tl, electron capture and beta decay and {sup 60} Co, beta-gamma emitter. In this way, a careful analysis of the implementation procedure with these radionuclides types, ranging on a broad energy spectral, was possible. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. Besides this intercomparisons, one was provided with a {sup 204} Tl solution, utilized in the international comparison recently promoted by BIPM, and another one with a {sup 60} C solution calibrated in LNMRI/CNEN previously by a relative calibration system, with a well type pressurized ionization chamber, and an absolute beta-gamma coincidence system, with a pill-box type proportional counter 4 {pi} geometry, coupled with a scintillator system with a sodium iodide cristal of 4x4 inches. The comparisons among LNMRI/CNEN results and the reference values, showed a small deviation of 1,32% for {sup 14} C, 0,40% for {sup 60} Co, 1,12% for {sup 55} Fe, 0,10% for {sup 90} Sr and 0,73% for {sup
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Three state quantum key distribution for small keys
International Nuclear Information System (INIS)
Batuwantudawe, J.; Boileau, J.-C.
2005-01-01
Full text: Quantum key distribution (QKD) protocols allow two parties, Alice and Bob, to establish secure keys. The most well-known protocol is BB84, using four distinct states. Recently, Phoenix et al. proposed a three state protocol. We explain the protocol and discuss its security proof. The three state protocol also has an interesting structure that allows for errors estimation from the inconclusive results (i.e.. where Alice and Bob choose different bases). This eliminates the need for sampling, potentially useful when qubits are limited. We discuss the effectiveness of this approach compared to BB84 for the case where a good error estimate is required. (author)
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Enabling interspecies epigenomic comparison with CEpBrowser.
Cao, Xiaoyi; Zhong, Sheng
2013-05-01
We developed the Comparative Epigenome Browser (CEpBrowser) to allow the public to perform multi-species epigenomic analysis. The web-based CEpBrowser integrates, manages and visualizes sequencing-based epigenomic datasets. Five key features were developed to maximize the efficiency of interspecies epigenomic comparisons. CEpBrowser is a web application implemented with PHP, MySQL, C and Apache. URL: http://www.cepbrowser.org/.
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Energy use and carbon dioxide emissions in the steel sector in key developing countries
Energy Technology Data Exchange (ETDEWEB)
Price, L.K.; Phylipsen, G.J.M.; Worrell, E.
2001-04-01
Iron and steel production consumes enormous quantities of energy, especially in developing countries where outdated, inefficient technologies are still used to produce iron and steel. Carbon dioxide emissions from steel production, which range between 5 and 15% of total country emissions in key developing countries (Brazil, China, India, Mexico, and South Africa), will continue to grow as these countries develop and as demand for steel products such as materials, automobiles, and appliances increases. In this report, we describe the key steel processes, discuss typical energy-intensity values for these processes, review historical trends in iron and steel production by process in five key developing countries, describe the steel industry in each of the five key developing countries, present international comparisons of energy use and carbon dioxide emissions among these countries, and provide our assessment of the technical potential to reduce these emissions based on best-practice benchmarking. Using a best practice benchmark, we find that significant savings, in the range of 33% to 49% of total primary energy used to produce steel, are technically possible in these countries. Similarly, we find that the technical potential for reducing intensities of carbon dioxide emissions ranges between 26% and 49% of total carbon dioxide emissions from steel production in these countries.
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Life cycle assessment in green chemistry: overview of key parameters and methodological concerns
DEFF Research Database (Denmark)
Tufvesson, Linda M.; Tufvesson, Pär; Woodley, John
2013-01-01
assessment (LCA) is a valuable methodology. However, on the planning stage, a full-scale LCA is considered to be too time consuming and complicated. Two reasons for this have been recognised, the method is too comprehensive and it is hard to find inventory data. In this review, key parameters are presented...... with the purpose to reduce the time-consuming steps in LCA.In this review, several LCAs of so-called ‘green chemicals’ are analysed and key parameters and methodological concerns are identified. Further, some conclusions on the environmental performance of chemicals were drawn.For fossil-based platform chemicals...... chemicals was identified. The environmental performance of bulk chemicals are closely connected to the production of the raw material and thereby different land use aspects. Here, a lot can be learnt from biofuel LCAs. In many of the reviewed articles focusing on bulk chemicals a comparison regarding fossil...
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Directory of Open Access Journals (Sweden)
Tsung-Hung Lin
2017-12-01
Full Text Available The security is a critical issue for business purposes. For example, the cloud meeting must consider strong security to maintain the communication privacy. Considering the scenario with cloud meeting, we apply extended chaotic map to present passwordless group authentication key agreement, termed as Passwordless Group Authentication Key Agreement (PL-GAKA. PL-GAKA improves the computation efficiency for the simple group password-based authenticated key agreement (SGPAKE proposed by Lee et al. in terms of computing the session key. Since the extended chaotic map has equivalent security level to the Diffie–Hellman key exchange scheme applied by SGPAKE, the security of PL-GAKA is not sacrificed when improving the computation efficiency. Moreover, PL-GAKA is a passwordless scheme, so the password maintenance is not necessary. Short-term authentication is considered, hence the communication security is stronger than other protocols by dynamically generating session key in each cloud meeting. In our analysis, we first prove that each meeting member can get the correct information during the meeting. We analyze common security issues for the proposed PL-GAKA in terms of session key security, mutual authentication, perfect forward security, and data integrity. Moreover, we also demonstrate that communicating in PL-GAKA is secure when suffering replay attacks, impersonation attacks, privileged insider attacks, and stolen-verifier attacks. Eventually, an overall comparison is given to show the performance between PL-GAKA, SGPAKE and related solutions.
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Quantum dense key distribution
International Nuclear Information System (INIS)
Degiovanni, I.P.; Ruo Berchera, I.; Castelletto, S.; Rastello, M.L.; Bovino, F.A.; Colla, A.M.; Castagnoli, G.
2004-01-01
This paper proposes a protocol for quantum dense key distribution. This protocol embeds the benefits of a quantum dense coding and a quantum key distribution and is able to generate shared secret keys four times more efficiently than the Bennet-Brassard 1984 protocol. We hereinafter prove the security of this scheme against individual eavesdropping attacks, and we present preliminary experimental results, showing its feasibility
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International Nuclear Information System (INIS)
Walenta, N; Gisin, N; Guinnard, O; Houlmann, R; Korzh, B; Lim, C W; Lunghi, T; Portmann, C; Thew, R T; Burg, A; Constantin, J; Caselunghe, D; Kulesza, N; Legré, M; Monat, L; Soucarros, M; Trinkler, P; Junod, P; Trolliet, G; Vannel, F
2014-01-01
We present a compactly integrated, 625 MHz clocked coherent one-way quantum key distribution system which continuously distributes secret keys over an optical fibre link. To support high secret key rates, we implemented a fast hardware key distillation engine which allows for key distillation rates up to 4 Mbps in real time. The system employs wavelength multiplexing in order to run over only a single optical fibre. Using fast gated InGaAs single photon detectors, we reliably distribute secret keys with a rate above 21 kbps over 25 km of optical fibre. We optimized the system considering a security analysis that respects finite-key-size effects, authentication costs and system errors for a security parameter of ε QKD = 4 × 10 −9 . (paper)
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Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing
2015-09-01
In this paper, a novel image encryption system with fingerprint used as a secret key is proposed based on the phase retrieval algorithm and RSA public key algorithm. In the system, the encryption keys include the fingerprint and the public key of RSA algorithm, while the decryption keys are the fingerprint and the private key of RSA algorithm. If the users share the fingerprint, then the system will meet the basic agreement of asymmetric cryptography. The system is also applicable for the information authentication. The fingerprint as secret key is used in both the encryption and decryption processes so that the receiver can identify the authenticity of the ciphertext by using the fingerprint in decryption process. Finally, the simulation results show the validity of the encryption scheme and the high robustness against attacks based on the phase retrieval technique.
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User-Centric Key Entropy: Study of Biometric Key Derivation Subject to Spoofing Attacks
Directory of Open Access Journals (Sweden)
Lavinia Mihaela Dinca
2017-02-01
Full Text Available Biometric data can be used as input for PKI key pair generation. The concept of not saving the private key is very appealing, but the implementation of such a system shouldn’t be rushed because it might prove less secure then current PKI infrastructure. One biometric characteristic can be easily spoofed, so it was believed that multi-modal biometrics would offer more security, because spoofing two or more biometrics would be very hard. This notion, of increased security of multi-modal biometric systems, was disproved for authentication and matching, studies showing that not only multi-modal biometric systems are not more secure, but they introduce additional vulnerabilities. This paper is a study on the implications of spoofing biometric data for retrieving the derived key. We demonstrate that spoofed biometrics can yield the same key, which in turn will lead an attacker to obtain the private key. A practical implementation is proposed using fingerprint and iris as biometrics and the fuzzy extractor for biometric key extraction. Our experiments show what happens when the biometric data is spoofed for both uni-modal systems and multi-modal. In case of multi-modal system tests were performed when spoofing one biometric or both. We provide detailed analysis of every scenario in regard to successful tests and overall key entropy. Our paper defines a biometric PKI scenario and an in depth security analysis for it. The analysis can be viewed as a blueprint for implementations of future similar systems, because it highlights the main security vulnerabilities for bioPKI. The analysis is not constrained to the biometric part of the system, but covers CA security, sensor security, communication interception, RSA encryption vulnerabilities regarding key entropy, and much more.
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Identifying tier one key suppliers.
Wicks, Steve
2013-01-01
In today's global marketplace, businesses are becoming increasingly reliant on suppliers for the provision of key processes, activities, products and services in support of their strategic business goals. The result is that now, more than ever, the failure of a key supplier has potential to damage reputation, productivity, compliance and financial performance seriously. Yet despite this, there is no recognised standard or guidance for identifying a tier one key supplier base and, up to now, there has been little or no research on how to do so effectively. This paper outlines the key findings of a BCI-sponsored research project to investigate good practice in identifying tier one key suppliers, and suggests a scalable framework process model and risk matrix tool to help businesses effectively identify their tier one key supplier base.
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ECTA/DaSy Framework Self-Assessment Comparison Tool
Center for IDEA Early Childhood Data Systems (DaSy), 2016
2016-01-01
The Self-Assessment Comparison (SAC) Tool is for state Part C and Section 619/Preschool programs to use to assess changes in the implementation of one or more components of the ECTA System Framework and/or subcomponenets of the DaSy Data System Framework. It is a companion to the ECTA/DaSy Framework Self-Assessment. Key features of the SAC are…
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Identification of the Key Fields and Their Key Technical Points of Oncology by Patent Analysis.
Zhang, Ting; Chen, Juan; Jia, Xiaofeng
2015-01-01
This paper aims to identify the key fields and their key technical points of oncology by patent analysis. Patents of oncology applied from 2006 to 2012 were searched in the Thomson Innovation database. The key fields and their key technical points were determined by analyzing the Derwent Classification (DC) and the International Patent Classification (IPC), respectively. Patent applications in the top ten DC occupied 80% of all the patent applications of oncology, which were the ten fields of oncology to be analyzed. The number of patent applications in these ten fields of oncology was standardized based on patent applications of oncology from 2006 to 2012. For each field, standardization was conducted separately for each of the seven years (2006-2012) and the mean of the seven standardized values was calculated to reflect the relative amount of patent applications in that field; meanwhile, regression analysis using time (year) and the standardized values of patent applications in seven years (2006-2012) was conducted so as to evaluate the trend of patent applications in each field. Two-dimensional quadrant analysis, together with the professional knowledge of oncology, was taken into consideration in determining the key fields of oncology. The fields located in the quadrant with high relative amount or increasing trend of patent applications are identified as key ones. By using the same method, the key technical points in each key field were identified. Altogether 116,820 patents of oncology applied from 2006 to 2012 were retrieved, and four key fields with twenty-nine key technical points were identified, including "natural products and polymers" with nine key technical points, "fermentation industry" with twelve ones, "electrical medical equipment" with four ones, and "diagnosis, surgery" with four ones. The results of this study could provide guidance on the development direction of oncology, and also help researchers broaden innovative ideas and discover new
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International Nuclear Information System (INIS)
Kessler, C.; Roger, P.
2005-07-01
The air kerma and ambient dose equivalent standards for the protection-level 60 Co beam have been re-established following the repositioning of the irradiator and modifications to the beam. Details concerning the standards and the new uncertainty budgets are described in this report with their implications for dosimetry comparisons and calibrations. (authors)
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Public Key Infrastructure Study
National Research Council Canada - National Science Library
Berkovits, Shimshon
1994-01-01
The National Institute of Standards and Technology (NIST) has tasked The MITRE Corporation to study the alternatives for automated management of public keys and of the associated public key certificates for the Federal Government...
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Comparison of two culture media for breaking seed dormancy and ...
African Journals Online (AJOL)
... the percentage germination and days to germination in each of the four species were higher and faster in water with agar medium in comparison to MS growth medium. These results suggest that the Linum seeds have exogenous and endogenous dormancy. Key words: Dormancy, germination, MS media, Linum species, ...
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Key Performance Indicators in the Evaluation of the Quality of Radiation Safety Programs.
Schultz, Cheryl Culver; Shaffer, Sheila; Fink-Bennett, Darlene; Winokur, Kay
2016-08-01
Beaumont is a multiple hospital health care system with a centralized radiation safety department. The health system operates under a broad scope Nuclear Regulatory Commission license but also maintains several other limited use NRC licenses in off-site facilities and clinics. The hospital-based program is expansive including diagnostic radiology and nuclear medicine (molecular imaging), interventional radiology, a comprehensive cardiovascular program, multiple forms of radiation therapy (low dose rate brachytherapy, high dose rate brachytherapy, external beam radiotherapy, and gamma knife), and the Research Institute (including basic bench top, human and animal). Each year, in the annual report, data is analyzed and then tracked and trended. While any summary report will, by nature, include items such as the number of pieces of equipment, inspections performed, staff monitored and educated and other similar parameters, not all include an objective review of the quality and effectiveness of the program. Through objective numerical data Beaumont adopted seven key performance indicators. The assertion made is that key performance indicators can be used to establish benchmarks for evaluation and comparison of the effectiveness and quality of radiation safety programs. Based on over a decade of data collection, and adoption of key performance indicators, this paper demonstrates one way to establish objective benchmarking for radiation safety programs in the health care environment.
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Key figures. Year 2006; Chiffres cles. Annee 2006
Energy Technology Data Exchange (ETDEWEB)
NONE
2006-07-01
This document summarizes in a series of tables the key data of the petroleum industry and of the other energies for the year 2006. Data of the two previous years are given for comparison: 1 - petroleum, France: exploration, reserves, production, transports (tankers, pipelines, crude and refined products), storage capacities, status of resources and uses, foreign trade (imports, prices, exports), refining (capacities, facilities), evolution of supplies, automotive fuels consumption; 2 - energies, France: production, consumption and trade data for coal, natural gas, electricity; total production and consumption of primary energy; consumption per sector of use; 3 - petroleum, world: crude production and reserves per geographical area, OPEC production, imports/exports and refining/consumption per geographical area, international quotation for crudes and refined products; 4 - energies, world: reserves, production and consumption data for coal, natural gas and electricity; uranium production and resources; total primary energy production and consumption per energy source and geographical area. (J.S.)
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Key figures. Year 2005; Chiffres cles. Annee 2005
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-07-01
This document summarizes in a series of tables the key data of the petroleum industry and of the other energies for the year 2005. Data of the two previous years are given for comparison: 1 - petroleum, France: exploration, reserves, production, transports (tankers, pipelines, crude and refined products), storage capacities, status of resources and uses, foreign trade (imports, prices, exports), refining (capacities, facilities), evolution of supplies, automotive fuels consumption; 2 - energies, France: production, consumption and trade data for coal, natural gas, electricity; total production and consumption of primary energy; consumption per sector of use; 3 - petroleum, world: crude production and reserves per geographical area, OPEC production, imports/exports and refining/consumption per geographical area, international quotation for crudes and refined products; 4 - energies, world: reserves, production and consumption data for coal, natural gas and electricity; uranium production and resources; total primary energy production and consumption per energy source and geographical area. (J.S.)
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Directory of Open Access Journals (Sweden)
María Fraile-Hurtado
2010-12-01
Full Text Available Biometry is the next step in authentication, why do not we take this stepforward in our communication security systems? Keys are the main disadvantage in the cryptography, what if we were our own key?
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de Oña, Juan; de Oña, Rocio; Eboli, Laura; Forciniti, Carmen; Mazzulla, Gabriella
2014-12-01
Road crashes can be caused by different factors, including infrastructure, vehicles, and human variables. Many research studies have focused solely on identifying the key factors that cause road crashes. From these studies, it emerged that human factors have the most relevant impact on accident severity. More specifically, accident severity depends on several factors related directly to the driver, i.e., driving experience, driver's socio-economic characteristics, and driving behavior and attitudes. In this paper, we investigate driver behaviors and attitudes while driving and specifically focus on different methods for identifying the factors that most affect the driver's perception of accident risk. To this end, we designed and conducted a survey in two different European contexts: the city of Cosenza, which is located in the south of Italy, and the city of Granada, which is located in the south of Spain. Samples of drivers were contacted for their opinions on certain aspects of driving rules and attitudes while driving, and different types of questions were addressed to the drivers to assess their judgments of these aspects. Consequently, different methods of data analysis were applied to determine the aspects that heavily influence driver perception of accident risk. An experiment based on the stated preferences (SP) was carried out with the drivers, and the SP data were analyzed using an ordered probit (OP) model. Interesting findings emerged from different analyses of the data and from the comparisons among the data collected in the two different territorial contexts. We found that both Italian and Spanish drivers consider driving in an altered psychophysical state and violating the overtaking rules to be the most risky behaviors. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Secret key rates in quantum key distribution using Renyi entropies
Energy Technology Data Exchange (ETDEWEB)
Abruzzo, Silvestre; Kampermann, Hermann; Mertz, Markus; Bratzik, Sylvia; Bruss, Dagmar [Institut fuer Theoretische Physik III, Heinrich-Heine-Universitaet Duesseldorf (Germany)
2010-07-01
The secret key rate r of a quantum key distribution protocol depends on the involved number of signals and the accepted ''failure probability''. We reconsider a method to calculate r focusing on the analysis of the privacy amplification given by R. Renner and R. Koenig (2005). This approach involves an optimization problem with an objective function depending on the Renyi entropy of the density operator describing the classical outcomes and the eavesdropper system. This problem is analyzed for a generic class of QKD protocols and the current research status is presented.
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Improved Anonymity for Key-trees
Veugen, P.J.M.; Beye, M.
2013-01-01
Randomized hash-lock protocols for Radio Frequency IDentification (RFID) tags offer forward untraceability, but incur heavy search on the server. Key trees have been proposed as a way to reduce search times, but because partial keys in such trees are shared, key compromise affects several tags.
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Smooth Phase Interpolated Keying
Borah, Deva K.
2007-01-01
Smooth phase interpolated keying (SPIK) is an improved method of computing smooth phase-modulation waveforms for radio communication systems that convey digital information. SPIK is applicable to a variety of phase-shift-keying (PSK) modulation schemes, including quaternary PSK (QPSK), octonary PSK (8PSK), and 16PSK. In comparison with a related prior method, SPIK offers advantages of better performance and less complexity of implementation. In a PSK scheme, the underlying information waveform that one seeks to convey consists of discrete rectangular steps, but the spectral width of such a waveform is excessive for practical radio communication. Therefore, the problem is to smooth the step phase waveform in such a manner as to maintain power and bandwidth efficiency without incurring an unacceptably large error rate and without introducing undesired variations in the amplitude of the affected radio signal. Although the ideal constellation of PSK phasor points does not cause amplitude variations, filtering of the modulation waveform (in which, typically, a rectangular pulse is converted to a square-root raised cosine pulse) causes amplitude fluctuations. If a power-efficient nonlinear amplifier is used in the radio communication system, the fluctuating-amplitude signal can undergo significant spectral regrowth, thus compromising the bandwidth efficiency of the system. In the related prior method, one seeks to solve the problem in a procedure that comprises two major steps: phase-value generation and phase interpolation. SPIK follows the two-step approach of the related prior method, but the details of the steps are different. In the phase-value-generation step, the phase values of symbols in the PSK constellation are determined by a phase function that is said to be maximally smooth and that is chosen to minimize the spectral spread of the modulated signal. In this step, the constellation is divided into two groups by assigning, to information symbols, phase values
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Gonzalez, Elias; Kish, Laszlo B.
2016-03-01
As the utilization of sensor networks continue to increase, the importance of security becomes more profound. Many industries depend on sensor networks for critical tasks, and a malicious entity can potentially cause catastrophic damage. We propose a new key exchange trust evaluation for peer-to-peer sensor networks, where part of the network has unconditionally secure key exchange. For a given sensor, the higher the portion of channels with unconditionally secure key exchange the higher the trust value. We give a brief introduction to unconditionally secured key exchange concepts and mention current trust measures in sensor networks. We demonstrate the new key exchange trust measure on a hypothetical sensor network using both wired and wireless communication channels.
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Whissel, R; Whissel, C
2000-12-01
Lyrics from 155 songs written by the Lennon-McCartney team were scored using the Dictionary of Affect in Language. Resultant scores (pleasantness, activation, and imagery of words) were compared across key signatures using one way analyses of variance. Words from songs written in minor keys were less pleasant and less active than those from songs written in major keys. Words from songs written in the key of F scored extremely low on all three measures. Lyrics from the keys of C, D, and G were relatively active in tone. Results from Dictionary scoring were compared with assignments of character to keys made more than one century ago and with current musicians' opinions.
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Key on demand (KoD) for software-defined optical networks secured by quantum key distribution (QKD).
Cao, Yuan; Zhao, Yongli; Colman-Meixner, Carlos; Yu, Xiaosong; Zhang, Jie
2017-10-30
Software-defined optical networking (SDON) will become the next generation optical network architecture. However, the optical layer and control layer of SDON are vulnerable to cyberattacks. While, data encryption is an effective method to minimize the negative effects of cyberattacks, secure key interchange is its major challenge which can be addressed by the quantum key distribution (QKD) technique. Hence, in this paper we discuss the integration of QKD with WDM optical networks to secure the SDON architecture by introducing a novel key on demand (KoD) scheme which is enabled by a novel routing, wavelength and key assignment (RWKA) algorithm. The QKD over SDON with KoD model follows two steps to provide security: i) quantum key pools (QKPs) construction for securing the control channels (CChs) and data channels (DChs); ii) the KoD scheme uses RWKA algorithm to allocate and update secret keys for different security requirements. To test our model, we define a security probability index which measures the security gain in CChs and DChs. Simulation results indicate that the security performance of CChs and DChs can be enhanced by provisioning sufficient secret keys in QKPs and performing key-updating considering potential cyberattacks. Also, KoD is beneficial to achieve a positive balance between security requirements and key resource usage.
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Is the Green Key standard the golden key for sustainability measurement in the hospitality sector?
Rietbergen, M.G.; Van Rheede, A.
2014-01-01
The Green Key is an eco-rating program that aims at promoting sustainable business practices in the hospitality sector. The Green Key assesses amongst others the sustainable management of energy, water and waste within hotels and other hospitality firms. The Green Key standard awards points if
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Key-Phenomenon and Religious Meaning
Directory of Open Access Journals (Sweden)
Lomuscio Vincenzo
2017-09-01
Full Text Available In this paper I develop a phenomenology of religious experience through the notion of keyphenomenon. My analysis moves from a general phenomenology of situation, in which we have to relate different phenomena according to a sense. What does “according to a sense” mean? My suggestion is that we should look for a relationship among these data when we find a key-phenomenon (among a series of phenomena that would enlighten all the others. This key-phenomenon would show a non-phenomenal meaning which would make all the others understandable. Each other datum, therefore, becomes the witness of invisible meaning through a key-witness. The key-phenomenon we choose determines the role (i.e., the truth of each datum within its situation. This phenomenological relationship belongs to both the sense of day-life situations, and that one of possible religious situations. If the religious interpretation of a situation depends on our choice of key-phenomenon, or key-witness, we have to define what kind of keyphenomenon constitutes a religious intuition.
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A permanent magnet system for Kibble balances
Li, Shisong; Bielsa, Franck; Stock, Michael; Kiss, Adrien; Fang, Hao
2017-10-01
The magnet is one of the fundamental elements in Kibble balances. The Kibble balance group at the Bureau International des Poids et Mesures (BIPM) proposed a permanent magnet with a radial field, which has been widely employed in other Kibble balance experiments. In this paper, we discuss a different method of operation for the BIPM-type magnet, i.e. only the lower half of the magnetic circuit is closed. The merit of such a magnet is its convenience for opening the air gap and adjusting the coil. A disadvantage is that it can yield a lower and sloped magnetic field profile with less shielding. In the approach described, high permeability yokes are used to flatten the magnetic profile, which has proven to be a novel and convenient approach for removing the nonuniformity of the magnetic profile due to magnet magnetization asymmetries. The performance of the half-closed BIPM magnet is evaluated using experimental measurements. The results show that the half-closed magnetic circuit retains most of the main features of the fully-closed magnet and is a good option for the early stages of Kibble balance operations. In addition, the profile change due to the coil current is predicted and experimentally verified with a bifilar coil. Related systematic effects are discussed for the Planck constant measurement.
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Deng, Zongyi
2001-05-01
The distinction between key ideas in teaching a high school science and key ideas in the corresponding discipline of science has been largely ignored in scholarly discourse about what science teachers should teach and about what they should know. This article clarifies this distinction through exploring how and why key ideas in teaching high school physics differ from key ideas in the discipline of physics. Its theoretical underpinnings include Dewey's (1902/1990) distinction between the psychological and the logical and Harré's (1986) epistemology of science. It analyzes how and why the key ideas in teaching color, the speed of light, and light interference at the high school level differ from the key ideas at the disciplinary level. The thesis is that key ideas in teaching high school physics can differ from key ideas in the discipline in some significant ways, and that the differences manifest Dewey's distinction. As a result, the article challenges the assumption of equating key ideas in teaching a high school science with key ideas in the corresponding discipline of science, and the assumption that having a college degree in science is sufficient to teach high school science. Furthermore, the article expands the concept of pedagogical content knowledge by arguing that key ideas in teaching high school physics constitute an essential component.
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Key personality traits of sales managers.
Lounsbury, John W; Foster, Nancy A; Levy, Jacob J; Gibson, Lucy W
2014-01-01
Sales managers are crucial for producing positive sales outcomes for companies. However, there has been a relative dearth of scholarly investigations into the personal attributes of sales managers. Such information could prove important in the recruitment, selection, training needs identification, career planning, counseling, and development of sales managers. Drawing on Holland's vocational theory, we sought to identify key personality traits that distinguish sales managers from other occupations and are related to their career satisfaction. The main sample was comprised of a total of 978 sales managers employed in a large number of companies across the United States (along with a comparison sample drawn from 79,512 individuals from other professional occupations). Participants completed an online version of Resource Associates' Personal Style Inventory as well a measure of career satisfaction. Our sample of 978 sales managers had higher levels of Assertiveness, Customer Service Orientation, Extraversion, Image Management, Optimism, and Visionary Style; and lower levels of Conscientiousness, Agreeableness, Intrinsic Motivation, Openness, and Tough-Mindedness than a sample of 79,512 individuals in a variety of other occupations. Nine of these traits were significantly correlated with sales managers' career satisfaction. Based on the results, a psychological profile of sales managers was presented as were implications for their recruitment, selection, training, development, and mentoring.
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A Distributed Shared Key Generation Procedure Using Fractional Keys
National Research Council Canada - National Science Library
Poovendran, Radha; Corson, M. S; Baras, J. S
1998-01-01
We present a new class of distributed key generation and recovery algorithms suitable for group communication systems where the group membership is either static or slowly time-varying, and must be tightly controlled...
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Lenstra, A.K.; Verheul, E.R.; Okamoto, T.
2000-01-01
This paper describes improved methods for XTR key representation and parameter generation (cf. [4]). If the field characteristic is properly chosen, the size of the XTR public key for signature applications can be reduced by a factor of three at the cost of a small one time computation for the
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Importance of the nature of comparison conditions for testing theory-based interventions: reply.
Michie, Susan; Prestwich, Andrew; de Bruin, Marijn
2010-09-01
The nature of comparison conditions is a much overlooked feature of designing and interpreting the results of randomized controlled trials, as outlined by Williams (see record 2010-18776-001). We agree that understanding the components and mechanisms of the comparison condition is necessary for making inferences about both intervention effectiveness (whether the intervention worked and which components may have contributed to such an effect) and about theoretical mediators (how it worked). The extent to which one can draw strong inferences regarding the efficacy and mechanisms of an intervention over the comparison is conditional upon a number of key points. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
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Shukla, Chitra; Thapliyal, Kishore; Pathak, Anirban
2017-12-01
Semi-quantum protocols that allow some of the users to remain classical are proposed for a large class of problems associated with secure communication and secure multiparty computation. Specifically, first-time semi-quantum protocols are proposed for key agreement, controlled deterministic secure communication and dialogue, and it is shown that the semi-quantum protocols for controlled deterministic secure communication and dialogue can be reduced to semi-quantum protocols for e-commerce and private comparison (socialist millionaire problem), respectively. Complementing with the earlier proposed semi-quantum schemes for key distribution, secret sharing and deterministic secure communication, set of schemes proposed here and subsequent discussions have established that almost every secure communication and computation tasks that can be performed using fully quantum protocols can also be performed in semi-quantum manner. Some of the proposed schemes are completely orthogonal-state-based, and thus, fundamentally different from the existing semi-quantum schemes that are conjugate coding-based. Security, efficiency and applicability of the proposed schemes have been discussed with appropriate importance.
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Key characteristics for tool choice in indicator-based sustainability assessment at farm level
Directory of Open Access Journals (Sweden)
Fleur Marchand
2014-09-01
Full Text Available Although the literature on sustainability assessment tools to support decision making in agriculture is rapidly growing, little attention has been paid to the actual tool choice. We focused on the choice of more complex integrated indicator-based tools at the farm level. The objective was to determine key characteristics as criteria for tool choice. This was done with an in-depth comparison of 2 cases: the Monitoring Tool for Integrated Farm Sustainability and the Public Goods Tool. They differ in characteristics that may influence tool choice: data, time, and budgetary requirements. With an enhanced framework, we derived 11 key characteristics to describe differences between the case tools. Based on the key characteristics, we defined 2 types of indicator-based tools: full sustainability assessment (FSA and rapid sustainability assessment (RSA. RSA tools are more oriented toward communicating and learning. They are therefore more suitable for use by a larger group of farmers, can help to raise awareness, trigger farmers to become interested in sustainable farming, and highlight areas of good or bad performance. If and when farmers increase their commitment to on-farm sustainability, they can gain additional insight by using an FSA tool. Based on complementary and modular use of the tools, practical recommendations for the different end users, i.e., researchers, farmers, advisers, and so forth, have been suggested.
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New weak keys in simplified IDEA
Hafman, Sari Agustini; Muhafidzah, Arini
2016-02-01
Simplified IDEA (S-IDEA) is simplified version of International Data Encryption Algorithm (IDEA) and useful teaching tool to help students to understand IDEA. In 2012, Muryanto and Hafman have found a weak key class in the S-IDEA by used differential characteristics in one-round (0, ν, 0, ν) → (0,0, ν, ν) on the first round to produce input difference (0,0, ν, ν) on the fifth round. Because Muryanto and Hafman only use three differential characteristics in one-round, we conducted a research to find new differential characteristics in one-round and used it to produce new weak key classes of S-IDEA. To find new differential characteristics in one-round of S-IDEA, we applied a multiplication mod 216+1 on input difference and combination of active sub key Z1, Z4, Z5, Z6. New classes of weak keys are obtained by combining all of these characteristics and use them to construct two new differential characteristics in full-round of S-IDEA with or without the 4th round sub key. In this research, we found six new differential characteristics in one round and combined them to construct two new differential characteristics in full-round of S-IDEA. When two new differential characteristics in full-round of S-IDEA are used and the 4th round sub key required, we obtain 2 new classes of weak keys, 213 and 28. When two new differential characteristics in full-round of S-IDEA are used, yet the 4th round sub key is not required, the weak key class of 213 will be 221 and 28 will be 210. Membership test can not be applied to recover the key bits in those weak key classes. The recovery of those unknown key bits can only be done by using brute force attack. The simulation result indicates that the bit of the key can be recovered by the longest computation time of 0,031 ms.
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2010-04-01
... 25 Indians 2 2010-04-01 2010-04-01 false Key employee. 502.14 Section 502.14 Indians NATIONAL....14 Key employee. Key employee means: (a) A person who performs one or more of the following functions... gaming operation. (d) Any other person designated by the tribe as a key employee. [57 FR 12392, Apr. 9...
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Directory of Open Access Journals (Sweden)
Zev bar-Lev
2016-12-01
Full Text Available Semantic Keys are elements (word-parts of written language that give an iconic, general representation of the whole word’s meaning. In written Sino-Japanese the “radical” or semantic components play this role. For example, the character meaning ‘woman, female’ is the Semantic Key of the character for Ma ‘Mama’ (alongside the phonetic component Ma, which means ‘horse’ as a separate character. The theory of semantic Keys in both graphic and phonemic aspects is called qTheory or nanosemantics. The most innovative aspect of the present article is the hypothesis that, in languages using alphabetic writing systems, the role of Semantic Key is played by consonants, more specifically the first consonant. Thus, L meaning ‘LIFT’ is the Semantic Key of English Lift, Ladle, Lofty, aLps, eLevator, oLympus; Spanish Leva, Lecantarse, aLto, Lengua; Arabic aLLah, and Hebrew① ªeL-ºaL ‘upto-above’ (the Israeli airline, Polish Lot ‘flight’ (the Polish airline; Hebrew ªeL, ªeLohim ‘God’, and haLLeluyah ‘praise-ye God’ (using Parallels, ‘Lift up God’. Evidence for the universality of the theory is shown by many examples drawn from various languages, including Indo-European Semitic, Chinese and Japanese. The theory reveals hundreds of relationships within and between languages, related and unrelated, that have been “Hiding in Plain Sight”, to mention just one example: the Parallel between Spanish Pan ‘bread’ and Mandarin Fan ‘rice’.
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Quantum key distribution via quantum encryption
Yong Sheng Zhang; Guang Can Guo
2001-01-01
A quantum key distribution protocol based on quantum encryption is presented in this Brief Report. In this protocol, the previously shared Einstein-Podolsky-Rosen pairs act as the quantum key to encode and decode the classical cryptography key. The quantum key is reusable and the eavesdropper cannot elicit any information from the particle Alice sends to Bob. The concept of quantum encryption is also discussed. (21 refs).
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Security for Key Management Interfaces
Kremer , Steve; Steel , Graham; Warinschi , Bogdan
2011-01-01
International audience; We propose a much-needed formal definition of security for cryptographic key management APIs. The advantages of our definition are that it is general, intuitive, and applicable to security proofs in both symbolic and computational models of cryptography. Our definition relies on an idealized API which allows only the most essential functions for generating, exporting and importing keys, and takes into account dynamic corruption of keys. Based on this we can define the ...
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Finite key analysis in quantum cryptography
International Nuclear Information System (INIS)
Meyer, T.
2007-01-01
In view of experimental realization of quantum key distribution schemes, the study of their efficiency becomes as important as the proof of their security. The latter is the subject of most of the theoretical work about quantum key distribution, and many important results such as the proof of unconditional security have been obtained. The efficiency and also the robustness of quantum key distribution protocols against noise can be measured by figures of merit such as the secret key rate (the fraction of input signals that make it into the key) and the threshold quantum bit error rate (the maximal error rate such that one can still create a secret key). It is important to determine these quantities because they tell us whether a certain quantum key distribution scheme can be used at all in a given situation and if so, how many secret key bits it can generate in a given time. However, these figures of merit are usually derived under the ''infinite key limit'' assumption, that is, one assumes that an infinite number of quantum states are send and that all sub-protocols of the scheme (in particular privacy amplification) are carried out on these infinitely large blocks. Such an assumption usually eases the analysis, but also leads to (potentially) too optimistic values for the quantities in question. In this thesis, we are explicitly avoiding the infinite key limit for the analysis of the privacy amplification step, which plays the most important role in a quantum key distribution scheme. We still assume that an optimal error correction code is applied and we do not take into account any statistical errors that might occur in the parameter estimation step. Renner and coworkers derived an explicit formula for the obtainable key rate in terms of Renyi entropies of the quantum states describing Alice's, Bob's, and Eve's systems. This results serves as a starting point for our analysis, and we derive an algorithm that efficiently computes the obtainable key rate for any
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Finite key analysis in quantum cryptography
Energy Technology Data Exchange (ETDEWEB)
Meyer, T.
2007-10-31
In view of experimental realization of quantum key distribution schemes, the study of their efficiency becomes as important as the proof of their security. The latter is the subject of most of the theoretical work about quantum key distribution, and many important results such as the proof of unconditional security have been obtained. The efficiency and also the robustness of quantum key distribution protocols against noise can be measured by figures of merit such as the secret key rate (the fraction of input signals that make it into the key) and the threshold quantum bit error rate (the maximal error rate such that one can still create a secret key). It is important to determine these quantities because they tell us whether a certain quantum key distribution scheme can be used at all in a given situation and if so, how many secret key bits it can generate in a given time. However, these figures of merit are usually derived under the ''infinite key limit'' assumption, that is, one assumes that an infinite number of quantum states are send and that all sub-protocols of the scheme (in particular privacy amplification) are carried out on these infinitely large blocks. Such an assumption usually eases the analysis, but also leads to (potentially) too optimistic values for the quantities in question. In this thesis, we are explicitly avoiding the infinite key limit for the analysis of the privacy amplification step, which plays the most important role in a quantum key distribution scheme. We still assume that an optimal error correction code is applied and we do not take into account any statistical errors that might occur in the parameter estimation step. Renner and coworkers derived an explicit formula for the obtainable key rate in terms of Renyi entropies of the quantum states describing Alice's, Bob's, and Eve's systems. This results serves as a starting point for our analysis, and we derive an algorithm that efficiently computes
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Key rate of quantum key distribution with hashed two-way classical communication
International Nuclear Information System (INIS)
Watanabe, Shun; Matsumoto, Ryutaroh; Uyematsu, Tomohiko; Kawano, Yasuhito
2007-01-01
We propose an information reconciliation protocol that uses two-way classical communication. The key rates of quantum key distribution (QKD) protocols that use our protocol are higher than those using previously known protocols for a wide range of error rates for the Bennett-Brassard 1984 and six-state protocols. We also clarify the relation between the proposed and known QKD protocols, and the relation between the proposed protocol and entanglement distillation protocols
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Frison, Eline; Eggermont, Steven
2016-03-01
Social networking sites, such as Facebook, offer adolescent users an ideal platform for negative comparison (i.e., experiencing negative feelings from social comparison). Although such negative comparison on Facebook has been associated with users' well-being, the reciprocal relations between the two remain unclear, particularly in an adolescent sample. To examine this reciprocal process, a two-wave study among a representative sample of Flemish adolescents was set up (N Time1 = 1,840). Data were analyzed using structural equation modeling. Cross-lagged analyses indicated that negative comparison on Facebook predicted decreases in life satisfaction over time. Conversely, lower scores on life satisfaction predicted increases in negative comparison on Facebook. The discussion focuses on the understanding of these findings, key limitations, directions for future research, and implications for prevention and intervention strategies.
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One-way quantum key distribution: Simple upper bound on the secret key rate
International Nuclear Information System (INIS)
Moroder, Tobias; Luetkenhaus, Norbert; Curty, Marcos
2006-01-01
We present a simple method to obtain an upper bound on the achievable secret key rate in quantum key distribution (QKD) protocols that use only unidirectional classical communication during the public-discussion phase. This method is based on a necessary precondition for one-way secret key distillation; the legitimate users need to prove that there exists no quantum state having a symmetric extension that is compatible with the available measurements results. The main advantage of the obtained upper bound is that it can be formulated as a semidefinite program, which can be efficiently solved. We illustrate our results by analyzing two well-known qubit-based QKD protocols: the four-state protocol and the six-state protocol
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Quantum key distribution network for multiple applications
Tajima, A.; Kondoh, T.; Ochi, T.; Fujiwara, M.; Yoshino, K.; Iizuka, H.; Sakamoto, T.; Tomita, A.; Shimamura, E.; Asami, S.; Sasaki, M.
2017-09-01
The fundamental architecture and functions of secure key management in a quantum key distribution (QKD) network with enhanced universal interfaces for smooth key sharing between arbitrary two nodes and enabling multiple secure communication applications are proposed. The proposed architecture consists of three layers: a quantum layer, key management layer and key supply layer. We explain the functions of each layer, the key formats in each layer and the key lifecycle for enabling a practical QKD network. A quantum key distribution-advanced encryption standard (QKD-AES) hybrid system and an encrypted smartphone system were developed as secure communication applications on our QKD network. The validity and usefulness of these systems were demonstrated on the Tokyo QKD Network testbed.
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Algorithms for Lightweight Key Exchange.
Alvarez, Rafael; Caballero-Gil, Cándido; Santonja, Juan; Zamora, Antonio
2017-06-27
Public-key cryptography is too slow for general purpose encryption, with most applications limiting its use as much as possible. Some secure protocols, especially those that enable forward secrecy, make a much heavier use of public-key cryptography, increasing the demand for lightweight cryptosystems that can be implemented in low powered or mobile devices. This performance requirements are even more significant in critical infrastructure and emergency scenarios where peer-to-peer networks are deployed for increased availability and resiliency. We benchmark several public-key key-exchange algorithms, determining those that are better for the requirements of critical infrastructure and emergency applications and propose a security framework based on these algorithms and study its application to decentralized node or sensor networks.
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Decoy State Quantum Key Distribution
Lo, Hoi-Kwong
2005-10-01
Quantum key distribution (QKD) allows two parties to communicate in absolute security based on the fundamental laws of physics. Up till now, it is widely believed that unconditionally secure QKD based on standard Bennett-Brassard (BB84) protocol is limited in both key generation rate and distance because of imperfect devices. Here, we solve these two problems directly by presenting new protocols that are feasible with only current technology. Surprisingly, our new protocols can make fiber-based QKD unconditionally secure at distances over 100km (for some experiments, such as GYS) and increase the key generation rate from O(η2) in prior art to O(η) where η is the overall transmittance. Our method is to develop the decoy state idea (first proposed by W.-Y. Hwang in "Quantum Key Distribution with High Loss: Toward Global Secure Communication", Phys. Rev. Lett. 91, 057901 (2003)) and consider simple extensions of the BB84 protocol. This part of work is published in "Decoy State Quantum Key Distribution", . We present a general theory of the decoy state protocol and propose a decoy method based on only one signal state and two decoy states. We perform optimization on the choice of intensities of the signal state and the two decoy states. Our result shows that a decoy state protocol with only two types of decoy states--a vacuum and a weak decoy state--asymptotically approaches the theoretical limit of the most general type of decoy state protocols (with an infinite number of decoy states). We also present a one-decoy-state protocol as a special case of Vacuum+Weak decoy method. Moreover, we provide estimations on the effects of statistical fluctuations and suggest that, even for long distance (larger than 100km) QKD, our two-decoy-state protocol can be implemented with only a few hours of experimental data. In conclusion, decoy state quantum key distribution is highly practical. This part of work is published in "Practical Decoy State for Quantum Key Distribution
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International Nuclear Information System (INIS)
Wätjen, U.; Altzitzoglou, T.; Ceccatelli, A.; Dikmen, H.; Emteborg, H.; Ferreux, L.; Frechou, C.; La Rosa, J.; Luca, A.; Moreno, Y.; Oropesa, P.; Pierre, S.; Schmiedel, M.
2012-01-01
Radioactivity found in wild food products has assumed greater importance when assessing the total exposure of the population. For this reason, IRMM has been developing a reference material for the activity concentration of three radionuclides in bilberry samples. In order to characterise this new material, a CCRI(II) supplementary comparison was organised. The difficulties encountered in this comparison are discussed, in particular the efficiency calibration for volume sources of gamma-ray emitters, and comparison reference values for 137 Cs and 40 K are calculated. - Highlights: ► CCRI(II) supplementary comparison for Cs-137 and K-40 in bilberry matrix completed. ► Fundamentally different methods used to establish link to SI traceable standards and SIR. ► Variation of results higher than in CCRI(II) key comparisons. ► Comparison reference values will be robust property values of IRMM reference material. ► Certified reference material for radioactivity in food developed.
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Kawakami, Shun; Sasaki, Toshihiko; Koashi, Masato
2017-07-01
An essential step in quantum key distribution is the estimation of parameters related to the leaked amount of information, which is usually done by sampling of the communication data. When the data size is finite, the final key rate depends on how the estimation process handles statistical fluctuations. Many of the present security analyses are based on the method with simple random sampling, where hypergeometric distribution or its known bounds are used for the estimation. Here we propose a concise method based on Bernoulli sampling, which is related to binomial distribution. Our method is suitable for the Bennett-Brassard 1984 (BB84) protocol with weak coherent pulses [C. H. Bennett and G. Brassard, Proceedings of the IEEE Conference on Computers, Systems and Signal Processing (IEEE, New York, 1984), Vol. 175], reducing the number of estimated parameters to achieve a higher key generation rate compared to the method with simple random sampling. We also apply the method to prove the security of the differential-quadrature-phase-shift (DQPS) protocol in the finite-key regime. The result indicates that the advantage of the DQPS protocol over the phase-encoding BB84 protocol in terms of the key rate, which was previously confirmed in the asymptotic regime, persists in the finite-key regime.
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Simon, M. K.
1975-01-01
Much has been said in the literature regarding the problem of establishing symbol synchronization in binary baseband digital communication systems. By comparison, the literature contains little information relating to the extraction of symbol sync from multilevel baseband data. With the recent interest in multilevel amplitude-shift keying (MASK) and quadrature amplitude-shift keying (QASK) as signaling techniques for multilevel digital communications systems, the problem of providing symbol synchronization in the receivers of such systems becomes paramount. This paper presents a technique for extracting symbol sync from a MASK or QASK signal which has been transmitted over an infinite-bandwidth white Gaussian noise channel. The scheme is essentially a generalization of the data transition tracking loop (DTTL) which has heretofore been used in PSK systems. The performance of the loop is analyzed in terms of its mean-squared symbol sync jitter and its effects on the data detection process in MASK and QASK systems.
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Cryptographic Key Management System
Energy Technology Data Exchange (ETDEWEB)
No, author
2014-02-21
This report summarizes the outcome of U.S. Department of Energy (DOE) contract DE-OE0000543, requesting the design of a Cryptographic Key Management System (CKMS) for the secure management of cryptographic keys for the energy sector infrastructure. Prime contractor Sypris Electronics, in collaboration with Oak Ridge National Laboratories (ORNL), Electric Power Research Institute (EPRI), Valicore Technologies, and Purdue University's Center for Education and Research in Information Assurance and Security (CERIAS) and Smart Meter Integration Laboratory (SMIL), has designed, developed and evaluated the CKMS solution. We provide an overview of the project in Section 3, review the core contributions of all contractors in Section 4, and discuss bene ts to the DOE in Section 5. In Section 6 we describe the technical construction of the CKMS solution, and review its key contributions in Section 6.9. Section 7 describes the evaluation and demonstration of the CKMS solution in different environments. We summarize the key project objectives in Section 8, list publications resulting from the project in Section 9, and conclude with a discussion on commercialization in Section 10 and future work in Section 11.
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VerSi. A method for the quantitative comparison of repository systems
Energy Technology Data Exchange (ETDEWEB)
Kaempfer, T.U.; Ruebel, A.; Resele, G. [AF-Consult Switzerland Ltd, Baden (Switzerland); Moenig, J. [GRS Braunschweig (Germany)
2015-07-01
Decision making and design processes for radioactive waste repositories are guided by safety goals that need to be achieved. In this context, the comparison of different disposal concepts can provide relevant support to better understand the performance of the repository systems. Such a task requires a method for a traceable comparison that is as objective as possible. We present a versatile method that allows for the comparison of different disposal concepts in potentially different host rocks. The condition for the method to work is that the repository systems are defined to a comparable level including designed repository structures, disposal concepts, and engineered and geological barriers which are all based on site-specific safety requirements. The method is primarily based on quantitative analyses and probabilistic model calculations regarding the long-term safety of the repository systems under consideration. The crucial evaluation criteria for the comparison are statistical key figures of indicators that characterize the radiotoxicity flux out of the so called containment-providing rock zone (einschlusswirksamer Gebirgsbereich). The key figures account for existing uncertainties with respect to the actual site properties, the safety relevant processes, and the potential future impact of external processes on the repository system, i.e., they include scenario-, process-, and parameter-uncertainties. The method (1) leads to an evaluation of the retention and containment capacity of the repository systems and its robustness with respect to existing uncertainties as well as to potential external influences; (2) specifies the procedures for the system analyses and the calculation of the statistical key figures as well as for the comparative interpretation of the key figures; and (3) also gives recommendations and sets benchmarks for the comparative assessment of the repository systems under consideration based on the key figures and additional qualitative
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Analysis of the differential-phase-shift-keying protocol in the quantum-key-distribution system
International Nuclear Information System (INIS)
Rong-Zhen, Jiao; Chen-Xu, Feng; Hai-Qiang, Ma
2009-01-01
The analysis is based on the error rate and the secure communication rate as functions of distance for three quantum-key-distribution (QKD) protocols: the Bennett–Brassard 1984, the Bennett–Brassard–Mermin 1992, and the coherent differential-phase-shift keying (DPSK) protocols. We consider the secure communication rate of the DPSK protocol against an arbitrary individual attack, including the most commonly considered intercept-resend and photon-number splitting attacks, and concluded that the simple and efficient differential-phase-shift-keying protocol allows for more than 200 km of secure communication distance with high communication rates. (general)
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DEFF Research Database (Denmark)
List, Markus; Alcaraz, Nicolas; Dissing-Hansen, Martin
2016-01-01
, for instance), KeyPathwayMiner extracts connected sub-networks containing a high number of active or differentially regulated genes (proteins, metabolites) in the molecular profiles. The web interface at (http://keypathwayminer.compbio.sdu.dk) implements all core functionalities of the KeyPathwayMiner tool set......We present KeyPathwayMinerWeb, the first online platform for de novo pathway enrichment analysis directly in the browser. Given a biological interaction network (e.g. protein-protein interactions) and a series of molecular profiles derived from one or multiple OMICS studies (gene expression...... such as data integration, input of background knowledge, batch runs for parameter optimization and visualization of extracted pathways. In addition to an intuitive web interface, we also implemented a RESTful API that now enables other online developers to integrate network enrichment as a web service...
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Corban, Robert
The systems engineering process for the concept definition phase of the program involves requirements definition, system definition, and consistent concept definition. The requirements definition process involves obtaining a complete understanding of the system requirements based on customer needs, mission scenarios, and nuclear thermal propulsion (NTP) operating characteristics. A system functional analysis is performed to provide a comprehensive traceability and verification of top-level requirements down to detailed system specifications and provides significant insight into the measures of system effectiveness to be utilized in system evaluation. The second key element in the process is the definition of system concepts to meet the requirements. This part of the process involves engine system and reactor contractor teams to develop alternative NTP system concepts that can be evaluated against specific attributes, as well as a reference configuration against which to compare system benefits and merits. Quality function deployment (QFD), as an excellent tool within Total Quality Management (TQM) techniques, can provide the required structure and provide a link to the voice of the customer in establishing critical system qualities and their relationships. The third element of the process is the consistent performance comparison. The comparison process involves validating developed concept data and quantifying system merits through analysis, computer modeling, simulation, and rapid prototyping of the proposed high risk NTP subsystems. The maximum amount possible of quantitative data will be developed and/or validated to be utilized in the QFD evaluation matrix. If upon evaluation of a new concept or its associated subsystems determine to have substantial merit, those features will be incorporated into the reference configuration for subsequent system definition and comparison efforts.
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SUPPLY CHAIN MANAGEMENT – KEY FACTORS
Magdalena Daniela DINU
2014-01-01
This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of bot...
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Key handling in wireless sensor networks
International Nuclear Information System (INIS)
Li, Y; Newe, T
2007-01-01
With the rapid growth of Wireless Sensor Networks (WSNs), many advanced application areas have received significant attention. However, security will be an important factor for their full adoption. Wireless sensor nodes pose unique challenges and as such traditional security protocols, used in traditional networks cannot be applied directly. Some new protocols have been published recently with the goal of providing both privacy of data and authentication of sensor nodes for WSNs. Such protocols can employ private-key and/or public key cryptographic algorithms. Public key algorithms hold the promise of simplifying the network infrastructure required to provide security services such as: privacy, authentication and non-repudiation, while symmetric algorithms require less processing power on the lower power wireless node. In this paper a selection of key establishment/agreement protocols are reviewed and they are broadly divided into two categories: group key agreement protocols and pair-wise key establishment protocols. A summary of the capabilities and security related services provided by each protocol is provided
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Key handling in wireless sensor networks
Energy Technology Data Exchange (ETDEWEB)
Li, Y; Newe, T [Optical Fibre Sensors Research Centre, Department of Electronic and Computer Engineering, University of Limerick, Limerick (Ireland)
2007-07-15
With the rapid growth of Wireless Sensor Networks (WSNs), many advanced application areas have received significant attention. However, security will be an important factor for their full adoption. Wireless sensor nodes pose unique challenges and as such traditional security protocols, used in traditional networks cannot be applied directly. Some new protocols have been published recently with the goal of providing both privacy of data and authentication of sensor nodes for WSNs. Such protocols can employ private-key and/or public key cryptographic algorithms. Public key algorithms hold the promise of simplifying the network infrastructure required to provide security services such as: privacy, authentication and non-repudiation, while symmetric algorithms require less processing power on the lower power wireless node. In this paper a selection of key establishment/agreement protocols are reviewed and they are broadly divided into two categories: group key agreement protocols and pair-wise key establishment protocols. A summary of the capabilities and security related services provided by each protocol is provided.
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Secret-key expansion from covert communication
Arrazola, Juan Miguel; Amiri, Ryan
2018-02-01
Covert communication allows the transmission of messages in such a way that it is not possible for adversaries to detect that the communication is occurring. This provides protection in situations where knowledge that two parties are talking to each other may be incriminating to them. In this work, we study how covert communication can be used for a different purpose: secret key expansion. First, we show that any message transmitted in a secure covert protocol is also secret and therefore unknown to an adversary. We then propose a covert communication protocol where the amount of key consumed in the protocol is smaller than the transmitted key, thus leading to secure secret key expansion. We derive precise conditions for secret key expansion to occur, showing that it is possible when there are sufficiently low levels of noise for a given security level. We conclude by examining how secret key expansion from covert communication can be performed in a computational security model.
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High-efficiency Gaussian key reconciliation in continuous variable quantum key distribution
Bai, ZengLiang; Wang, XuYang; Yang, ShenShen; Li, YongMin
2016-01-01
Efficient reconciliation is a crucial step in continuous variable quantum key distribution. The progressive-edge-growth (PEG) algorithm is an efficient method to construct relatively short block length low-density parity-check (LDPC) codes. The qua-sicyclic construction method can extend short block length codes and further eliminate the shortest cycle. In this paper, by combining the PEG algorithm and qua-si-cyclic construction method, we design long block length irregular LDPC codes with high error-correcting capacity. Based on these LDPC codes, we achieve high-efficiency Gaussian key reconciliation with slice recon-ciliation based on multilevel coding/multistage decoding with an efficiency of 93.7%.
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Dellson, P; Nilbert, M; Bendahl, P-O; Malmström, P; Carlsson, C
2011-07-01
Clinical trials are crucial to improve cancer treatment but recruitment is difficult. Optimised patient information has been recognised as a key issue. In line with the increasing focus on patients' perspectives in health care, we aimed to study patients' opinions about the written information used in three clinical trials for breast cancer. Primary data collection was done in focus group interviews with breast cancer patient advocates. Content analysis identified three major themes: comprehensibility, emotions and associations, and decision making. Based on the advocates' suggestions for improvements, 21 key issues were defined and validated through a questionnaire in an independent group of breast cancer patient advocates. Clear messages, emotionally neutral expressions, careful descriptions of side effects, clear comparisons between different treatment alternatives and information about the possibility to discontinue treatment were perceived as the most important issues. Patients' views of the information in clinical trials provide new insights and identify key issues to consider in optimising future written information and may improve recruitment to clinical cancer trials. © 2010 Blackwell Publishing Ltd.
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FPGA BASED HARDWARE KEY FOR TEMPORAL ENCRYPTION
Directory of Open Access Journals (Sweden)
B. Lakshmi
2010-09-01
Full Text Available In this paper, a novel encryption scheme with time based key technique on an FPGA is presented. Time based key technique ensures right key to be entered at right time and hence, vulnerability of encryption through brute force attack is eliminated. Presently available encryption systems, suffer from Brute force attack and in such a case, the time taken for breaking a code depends on the system used for cryptanalysis. The proposed scheme provides an effective method in which the time is taken as the second dimension of the key so that the same system can defend against brute force attack more vigorously. In the proposed scheme, the key is rotated continuously and four bits are drawn from the key with their concatenated value representing the delay the system has to wait. This forms the time based key concept. Also the key based function selection from a pool of functions enhances the confusion and diffusion to defend against linear and differential attacks while the time factor inclusion makes the brute force attack nearly impossible. In the proposed scheme, the key scheduler is implemented on FPGA that generates the right key at right time intervals which is then connected to a NIOS – II processor (a virtual microcontroller which is brought out from Altera FPGA that communicates with the keys to the personal computer through JTAG (Joint Test Action Group communication and the computer is used to perform encryption (or decryption. In this case the FPGA serves as hardware key (dongle for data encryption (or decryption.
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Key Management Strategies for Safeguards Authentication and Encryption
International Nuclear Information System (INIS)
Coram, M.; Hymel, R.; McDaniel, M.; Brotz, J.
2015-01-01
Management of cryptographic keys for the authentication and encryption of safeguards data can be the critical weak link in the practical implementation of information security. Within the safeguards community, there is the need to validate that data has not been modified at any point since generation and that it was generated by the monitoring node and not an imposter. In addition, there is the need for that data to be transmitted securely between the monitoring node and the monitoring party such that it cannot be intercepted and read while in transit. Encryption and digital signatures support the required confidentiality and authenticity but challenges exist in managing the cryptographic keys they require. Technologies developed at Sandia National Laboratories have evolved in their use of an associated key management strategy. The first generation system utilized a shared secret key for digital signatures. While fast and efficient, it required that a list of keys be maintained and protected. If control of the key was lost, fraudulent data could be made to look authentic. The second generation changed to support public key / private key cryptography. The key pair is generated by the system, the public key shared, and the private key held internally. This approach eliminated the need to maintain the list of keys. It also allows the public key to be provided to anyone needing to authenticate the data without allowing them to spoof data. A third generation system, currently under development, improves upon the public key / private key approach to address a potential man-in-the-middle attack related to the sharing of the public key. In a planned fourth generation system, secure key exchange protocols will distribute session keys for encryption, eliminating another fixed set of keys utilized by the technology and allowing for periodic renegotiation of keys for enhanced security. (author)
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Identifying Key Drivers of Return Reversal with Dynamical Bayesian Factor Graph.
Directory of Open Access Journals (Sweden)
Shuai Zhao
Full Text Available In the stock market, return reversal occurs when investors sell overbought stocks and buy oversold stocks, reversing the stocks' price trends. In this paper, we develop a new method to identify key drivers of return reversal by incorporating a comprehensive set of factors derived from different economic theories into one unified dynamical Bayesian factor graph. We then use the model to depict factor relationships and their dynamics, from which we make some interesting discoveries about the mechanism behind return reversals. Through extensive experiments on the US stock market, we conclude that among the various factors, the liquidity factors consistently emerge as key drivers of return reversal, which is in support of the theory of liquidity effect. Specifically, we find that stocks with high turnover rates or high Amihud illiquidity measures have a greater probability of experiencing return reversals. Apart from the consistent drivers, we find other drivers of return reversal that generally change from year to year, and they serve as important characteristics for evaluating the trends of stock returns. Besides, we also identify some seldom discussed yet enlightening inter-factor relationships, one of which shows that stocks in Finance and Insurance industry are more likely to have high Amihud illiquidity measures in comparison with those in other industries. These conclusions are robust for return reversals under different thresholds.
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Key performance indicators to benchmark hospital information systems - a delphi study.
Hübner-Bloder, G; Ammenwerth, E
2009-01-01
To identify the key performance indicators for hospital information systems (HIS) that can be used for HIS benchmarking. A Delphi survey with one qualitative and two quantitative rounds. Forty-four HIS experts from health care IT practice and academia participated in all three rounds. Seventy-seven performance indicators were identified and organized into eight categories: technical quality, software quality, architecture and interface quality, IT vendor quality, IT support and IT department quality, workflow support quality, IT outcome quality, and IT costs. The highest ranked indicators are related to clinical workflow support and user satisfaction. Isolated technical indicators or cost indicators were not seen as useful. The experts favored an interdisciplinary group of all the stakeholders, led by hospital management, to conduct the HIS benchmarking. They proposed benchmarking activities both in regular (annual) intervals as well as at defined events (for example after IT introduction). Most of the experts stated that in their institutions no HIS benchmarking activities are being performed at the moment. In the context of IT governance, IT benchmarking is gaining importance in the healthcare area. The found indicators reflect the view of health care IT professionals and researchers. Research is needed to further validate and operationalize key performance indicators, to provide an IT benchmarking framework, and to provide open repositories for a comparison of the HIS benchmarks of different hospitals.
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Harry Potter and the Dichotomous Key
Crowther, David T.
2003-01-01
In this lesson, students use Bertie Bott's Every Flavor Beans--a "wild" candy written about in the Harry Potter books and now available in stores--to learn about classification and dichotomous keys. In these activities, students sort jelly beans according to a key and then construct a key for a "new" flavor of beans. Students then build on their…
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124Sb - Activity measurement and determination of photon emission intensities
International Nuclear Information System (INIS)
Be, M.M.; Chauvenet, B.
2009-07-01
The international traceability of antimony 124, in term of activity, is very limited. The results of 124 Sb activity measurements sent to the SIR (BIPM - International System of Reference, BIPM.RI(II)-K1.Sb-124.) are scarce. Up to now, only three laboratories have contributed. Two of them carried out measurements using the 4πβ-γ coincidence counting technique and the third one using the 4πγ method with a well-type crystal detector. The first two results are in agreement but the last one differs significantly from them, by 2 %. The decay scheme consistency cannot be excluded when trying to explain those discrepancies. In other respects, this nuclide emits high-energy gamma rays, and then could be selected as a valuable standard radionuclide for the calibration of gamma-ray detectors in that energy range, given well known photon intensities. Those considerations led to the proposal of an international exercise and to the realisation of this Euromet project, registered as project no. 907, coordinated by CEA-List-LNE/LNHB. The first part of this exercise was dedicated to activity measurements and to their comparison. For this purpose, participants were asked to make use of all the direct measurement techniques available in their laboratory in order to confirm or not the existence of possible biases specific to some measuring methods. In addition, this exercise offered the opportunity of improving the uncertainties of the gamma-ray intensities. Then, participants were asked, in the second part of the exercise, to carry out X-ray and gamma-ray intensity measurements. These results have been compared to previous published values and new decay scheme data are proposed. Eight international laboratories participated in this exercise. (authors)
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VICKEY: Mining Conditional Keys on Knowledge Bases
Symeonidou , Danai; Galárraga , Luis; Pernelle , Nathalie; Saïs , Fatiha; Suchanek , Fabian
2017-01-01
International audience; A conditional key is a key constraint that is valid in only a part of the data. In this paper, we show how such keys can be mined automatically on large knowledge bases (KBs). For this, we combine techniques from key mining with techniques from rule mining. We show that our method can scale to KBs of millions of facts. We also show that the conditional keys we mine can improve the quality of entity linking by up to 47 percentage points.
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Multiple Information Fusion Face Ｒecognition Using Key Feature Points
Directory of Open Access Journals (Sweden)
LIN Kezheng
2017-06-01
Full Text Available After years of face recognition research，due to the effect of illumination，noise and other conditions have led to the recognition rate is relatively low，2 d face recognition technology has couldn’t keep up with the pace of The Times the forefront，Although 3 d face recognition technology is developing step by step，but it has a higher complexity. In order to solve this problem，based on the traditional depth information positioning method and local characteristic analysis methods LFA，puts forward an improved 3 d face key feature points localization algorithm， and on the basis of the trained sample which obtained by complete cluster，further put forward the global and local feature extraction algorithm of weighted fusion. Through FＲGC and BU-3DFE experiment data comparison and analysis of the two face library，the method in terms of 3 d face recognition effect has a higher robustness.
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VICKEY: Mining Conditional Keys on Knowledge Bases
DEFF Research Database (Denmark)
Symeonidou, Danai; Prado, Luis Antonio Galarraga Del; Pernelle, Nathalie
2017-01-01
A conditional key is a key constraint that is valid in only a part of the data. In this paper, we show how such keys can be mined automatically on large knowledge bases (KBs). For this, we combine techniques from key mining with techniques from rule mining. We show that our method can scale to KBs...
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Key distillation in quantum cryptography
Slutsky, Boris Aron
1998-11-01
Quantum cryptography is a technique which permits two parties to communicate over an open channel and establish a shared sequence of bits known only to themselves. This task, provably impossible in classical cryptography, is accomplished by encoding the data on quantum particles and harnessing their unique properties. It is believed that no eavesdropping attack consistent with the laws of quantum theory can compromise the secret data unknowingly to the legitimate users of the channel. Any attempt by a hostile actor to monitor the data carrying particles while in transit reveals itself through transmission errors it must inevitably introduce. Unfortunately, in practice a communication is not free of errors even when no eavesdropping is present. Key distillation is a technique that permits the parties to overcome this difficulty and establish a secret key despite channel defects, under the assumption that every particle is handled independently from other particles by the enemy. In the present work, key distillation is described and its various aspects are studied. A relationship is derived between the average error rate resulting from an eavesdropping attack and the amount of information obtained by the attacker. Formal definition is developed of the security of the final key. The net throughput of secret bits in a quantum cryptosystem employing key distillation is assessed. An overview of quantum cryptographic protocols and related information theoretical results is also given.
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Dynamic Session-Key Generation for Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Chen Chin-Ling
2008-01-01
Full Text Available Abstract Recently, wireless sensor networks have been used extensively in different domains. For example, if the wireless sensor node of a wireless sensor network is distributed in an insecure area, a secret key must be used to protect the transmission between the sensor nodes. Most of the existing methods consist of preselecting keys from a key pool and forming a key chain. Then, the sensor nodes make use of the key chain to encrypt the data. However, while the secret key is being transmitted, it can easily be exposed during transmission. We propose a dynamic key management protocol, which can improve the security of the key juxtaposed to existing methods. Additionally, the dynamic update of the key can lower the probability of the key to being guessed correctly. In addition, with the new protocol, attacks on the wireless sensor network can be avoided.
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Dynamic Session-Key Generation for Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Cheng-Ta Li
2008-09-01
Full Text Available Recently, wireless sensor networks have been used extensively in different domains. For example, if the wireless sensor node of a wireless sensor network is distributed in an insecure area, a secret key must be used to protect the transmission between the sensor nodes. Most of the existing methods consist of preselecting m keys from a key pool and forming a key chain. Then, the sensor nodes make use of the key chain to encrypt the data. However, while the secret key is being transmitted, it can easily be exposed during transmission. We propose a dynamic key management protocol, which can improve the security of the key juxtaposed to existing methods. Additionally, the dynamic update of the key can lower the probability of the key to being guessed correctly. In addition, with the new protocol, attacks on the wireless sensor network can be avoided.
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DEFF Research Database (Denmark)
Hussain, M. Azhar; Siersbæk, Nikolaj; Østerdal, Lars Peter
How did the financial crisis affect population welfare in EU member states in key dimensions such as income, health, and education? Using EU-SILC data, we seek to answer this question by way of first order dominance comparisons between countries and over time. The novel feature of our study...... is that we perform welfare comparisons on the basis of multi-level multidimensional ordinal data. We find that the countries most often dominated are southern and eastern European member states, and the dominant countries are mostly northern and western European member states. However, for most country...
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Securing information using optically generated biometric keys
Verma, Gaurav; Sinha, Aloka
2016-11-01
In this paper, we present a new technique to obtain biometric keys by using the fingerprint of a person for an optical image encryption system. The key generation scheme uses the fingerprint biometric information in terms of the amplitude mask (AM) and the phase mask (PM) of the reconstructed fingerprint image that is implemented using the digital holographic technique. Statistical tests have been conducted to check the randomness of the fingerprint PM key that enables its usage as an image encryption key. To explore the utility of the generated biometric keys, an optical image encryption system has been further demonstrated based on the phase retrieval algorithm and the double random phase encoding scheme in which keys for the encryption are used as the AM and the PM key. The advantage associated with the proposed scheme is that the biometric keys’ retrieval requires the simultaneous presence of the fingerprint hologram and the correct knowledge of the reconstruction parameters at the decryption stage, which not only verifies the authenticity of the person but also protects the valuable fingerprint biometric features of the keys. Numerical results are carried out to prove the feasibility and the effectiveness of the proposed encryption system.
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On the Security of a Simple Three-Party Key Exchange Protocol without Server’s Public Keys
Directory of Open Access Journals (Sweden)
Junghyun Nam
2014-01-01
Full Text Available Authenticated key exchange protocols are of fundamental importance in securing communications and are now extensively deployed for use in various real-world network applications. In this work, we reveal major previously unpublished security vulnerabilities in the password-based authenticated three-party key exchange protocol according to Lee and Hwang (2010: (1 the Lee-Hwang protocol is susceptible to a man-in-the-middle attack and thus fails to achieve implicit key authentication; (2 the protocol cannot protect clients’ passwords against an offline dictionary attack; and (3 the indistinguishability-based security of the protocol can be easily broken even in the presence of a passive adversary. We also propose an improved password-based authenticated three-party key exchange protocol that addresses the security vulnerabilities identified in the Lee-Hwang protocol.
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SUPPLY CHAIN MANAGEMENT – KEY FACTORS
Directory of Open Access Journals (Sweden)
Magdalena Daniela DINU
2014-06-01
Full Text Available This paper exposes Supply Chain Management by its key factors. Briefly, where the Supply Chain Management is treated as strategic part of a company then maintaining both control and influence throughout the entire supply chain are key factors and critical to success. On the other hand, finding the right partner to manage the non-strategic Supply Chains would be another key factor too. To define the most important key factors within Supply Chain Management means a deeply understanding of both Supply Chain’ s components, procedures, workflow, processes and the importance of Supply Chain Management into maximizing company's value. SCORE model able to provide solid information about measuring performance and identifying priorities within Supply Chain Management will help us to understand the key factors by analyzing its elements: Plan, Source, Make, Deliver,Return, Enable. These elements covers all the challenging areas from first to third tier of Supply Chain Management.
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Model plant Key Measurement Points
International Nuclear Information System (INIS)
Schneider, R.A.
1984-01-01
For IAEA safeguards a Key Measurement Point is defined as the location where nuclear material appears in such a form that it may be measured to determine material flow or inventory. This presentation describes in an introductory manner the key measurement points and associated measurements for the model plant used in this training course
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Bilateral Comparison Between NIM and NMC Over the Temperature Range from 83.8058 K to 692.677 K
Sun, Jianping; Ye, Shaochun; Kho, Haoyuan; Zhang, Jintao; Wang, Li
2015-08-01
A bilateral comparison of local realization of the International Temperature Scale of 1990 between the National Institute of Metrology (NIM) and National Metrology Centre (NMC) was carried out over the temperature range from 83.8058 K to 692.677 K. It involved six fixed points including the argon triple point, the mercury triple point, the triple point of water, the melting point of gallium, the freezing point of tin, and the freezing point of zinc. In 2009, NMC asked NIM to participate in a bilateral comparison to link the NMC results to the Consultative Committee for Thermometry Key Comparison 3 (CCT-K3) and facilitate the NMC's calibration and measurement capabilities submission. This comparison was agreed by NIM and Asia Pacific Metrology Programme in 2009, and registered in the Key Comparison Database in 2010 as CCT-K3.2. NMC supplied two fused silica sheath standard platinum resistance thermometers (SPRTs) as traveling standards. One of them was used at the Ga, Sn, and Zn fixed points, while the other one was used at the Ar and Hg fixed points. NMC measured them before and after NIM measured them. During the comparison, a criterion for the SPRT was set as the stability at the triple point of water to be less than 0.3 mK. The results for both laboratories are summarized. A proposal for linking the NMC's comparison results to CCT-K3 is presented. The difference between NMC and NIM and the difference between NMC and the CCT-K3 average reference value using NIM as a link are reported with expanded uncertainties at each measured fixed point.
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Competency Assessment Using Key Performance Indicators
Elena Alexandra Toader; Laura Brad
2015-01-01
The paper proposes a method for computing the scores of the key performance indicators resulted in the competency assessment process. The key performance indicators are estimated considering four performance levels that an IT professional can obtain at the end of the assessment process. We suggest as the best approach for estimating the performance key indicators an online questionnaire filled by 60 employees that work in IT Romanian companies. The results provide evidence that the difference...
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Diffie-Hellman Key Exchange through Steganographied Images
Directory of Open Access Journals (Sweden)
Amine Khaldi
2018-05-01
Full Text Available Purpose – In a private key system, the major problem is the exchange of the key between the two parties. Diffie and Hellman have set up a way to share the key. However, this technique is not protected against a man-in-the-middle attack as the settings are not authenticated. The Diffie-Hellman key exchange requires the use of digital signature or creating a secure channel for data exchanging to avoid the man-in-the-middle attack. Methodology/approach/design – We present a Diffie-Hellman key exchange implementation using steganographied images. Using steganography made invisible the data exchange to a potential attacker. So, we will not need a digital signature or creating a secure channel to do our key exchange since only the two concerned parts are aware of this exchange. Findings – We generate a symmetric 128-bit key between two users without use of digital signature or secure channel. However, it works only on bitmap images, heavy images and sensitive to compression.
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A Novel Key Distribution Solution for Combined Public/Secret Key ...
African Journals Online (AJOL)
Moreover, an implementation over the new IPv6 Internet protocol is presented such that the system can be ported to both wired and wireless networking environments. Keywords: cryptography, key distribution, security server. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...
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Comparison of source-term calculations using the AREST and SYVAC-Vault models: [Final report
International Nuclear Information System (INIS)
Apted, M.J.; Engel, D.W.; Garisto, N.C.; LeNeveu, D.M.
1988-07-01
A comparison of the calculated radionuclide release from a waste package in a geologic repository has been performed using the verified SYVAC-Vault Model and AREST Model. the purpose of this comparison is to further establish the credibility of these codes for predictive performance assessment and to identify improvements that may be required. A reference case for a Canadian conceptual design with spent fuel as the waste form was chosen to make an initial comparison. The results from the two models were in good agreement, including peak release rates, time to reach peak release, and long term release rates. Differences in results from the two models are attributed to differences in computational approaches. Studies of the effects of sorption, convective flow, distributed containment failure, and precipitation are identified as key areas for further comparisons and are currently in progress. 11 refs., 3 figs., 5 tabs
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Enciphered Data Steganography Using Secret Key
Directory of Open Access Journals (Sweden)
BANGALORE G.Tilak
2010-10-01
Full Text Available A new method is proposed to maintain thesecrecy of data by enciphering and embedding using asecret key. There is no restriction on the length of thekey used to encipher and embed the data. Since the keyis not stored for validation, it prevents unauthorizedaccess to the key, even if decoding procedure is known.The correct message can be recovered only with thespecific key used in encipherment and embedding. Thismethod can also be used for multiple levelsteganography.
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Fully device-independent conference key agreement
Ribeiro, Jérémy; Murta, Gláucia; Wehner, Stephanie
2018-02-01
We present a security analysis of conference key agreement (CKA) in the most adversarial model of device independence (DI). Our protocol can be implemented by any experimental setup that is capable of performing Bell tests [specifically, the Mermin-Ardehali-Belinskii-Klyshko (MABK) inequality], and security can in principle be obtained for any violation of the MABK inequality that detects genuine multipartite entanglement among the N parties involved in the protocol. As our main tool, we derive a direct physical connection between the N -partite MABK inequality and the Clauser-Horne-Shimony-Holt (CHSH) inequality, showing that certain violations of the MABK inequality correspond to a violation of the CHSH inequality between one of the parties and the other N -1 . We compare the asymptotic key rate for device-independent conference key agreement (DICKA) to the case where the parties use N -1 device-independent quantum key distribution protocols in order to generate a common key. We show that for some regime of noise the DICKA protocol leads to better rates.
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Energy Technology Data Exchange (ETDEWEB)
NONE
2010-07-01
The IEA produced its first handy, pocket-sized summary of key energy data in 1997. This new edition responds to the enormously positive reaction to the book since then. Key World Energy Statistics produced by the IEA contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts. It exists in different formats to suit our readers' requirements.
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What are the key drivers of MAC curves? A partial-equilibrium modelling approach for the UK
International Nuclear Information System (INIS)
Kesicki, Fabian
2013-01-01
Marginal abatement cost (MAC) curves are widely used for the assessment of costs related to CO 2 emissions reduction in environmental economics, as well as domestic and international climate policy. Several meta-analyses and model comparisons have previously been performed that aim to identify the causes for the wide range of MAC curves. Most of these concentrate on general equilibrium models with a focus on aspects such as specific model type and technology learning, while other important aspects remain almost unconsidered, including the availability of abatement technologies and level of discount rates. This paper addresses the influence of several key parameters on MAC curves for the United Kingdom and the year 2030. A technology-rich energy system model, UK MARKAL, is used to derive the MAC curves. The results of this study show that MAC curves are robust even to extreme fossil fuel price changes, while uncertainty around the choice of the discount rate, the availability of key abatement technologies and the demand level were singled out as the most important influencing factors. By using a different model type and studying a wider range of influencing factors, this paper contributes to the debate on the sensitivity of MAC curves. - Highlights: ► A partial-equilibrium model is employed to test key sensitivities of MAC curves. ► MAC curves are found to be robust to wide-ranging changes in fossil fuel prices. ► Most influencing factors are the discount rate, availability of key technologies. ► Further important uncertainty in MAC curves is related to demand changes
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International Nuclear Information System (INIS)
1994-01-01
The key numbers of energy give statistical data related to production, consumption, and to foreign trade of each energy in the World and in France. A chapter is dedicated to environment and brings quantitative elements on pollutant emissions connected to energy uses
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Omerbashich, Mensur
2015-01-01
World oldest authority for scientific constants and the keeper of the original metre standard, the International Bureau of Weights and Measures (BIPM) in Paris, France has accomplished a historic confirmation of the Omerbashich's (first-ever) scientific prediction of value of the Newtonian gravitational constant G.
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Rael, Christine T; Davis, Alissa
2017-04-01
Little is known about the mental health of female sex workers and women living with HIV/AIDS in the Dominican Republic, which impedes HIV prevention, testing, and treatment. This project estimates the prevalence of depression and identifies key contributing factors to this outcome in female sex workers, women living with HIV/AIDS, and a comparison group. Participants were female sex workers (N = 349), women living with HIV/AIDS (N = 213), and a comparison group of HIV-negative women who were not sex workers (N = 314) from the Dominican Republic. Participants completed questionnaires assessing demographic characteristics and depression. Female sex workers and women living with HIV/AIDS completed additional questionnaires ascertaining HIV or sex work-related internalized stigma. Depression was prevalent among female sex workers (70.2%), women living with HIV/AIDS (81.1%), and the comparison group (52.2%). Adjusted logistic regressions showed that internalized stigma was associated with depression for female sex workers (OR = 2.73; 95% CI = 1.95-3.84) and women living with HIV/AIDS (OR = 3.06; 95% CI = 1.86-5.05). Permanent income was associated with this outcome for female sex workers (OR = 0.08; 95% CI = 0.01-0.80) and the comparison group (OR = 0.04; 95% CI = 0.00-0.45).
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Multiparty quantum key agreement with single particles
Liu, Bin; Gao, Fei; Huang, Wei; Wen, Qiao-yan
2013-04-01
Two conditions must be satisfied in a secure quantum key agreement (QKA) protocol: (1) outside eavesdroppers cannot gain the generated key without introducing any error; (2) the generated key cannot be determined by any non-trivial subset of the participants. That is, a secure QKA protocol can not only prevent the outside attackers from stealing the key, but also resist the attack from inside participants, i.e. some dishonest participants determine the key alone by illegal means. How to resist participant attack is an aporia in the design of QKA protocols, especially the multi-party ones. In this paper we present the first secure multiparty QKA protocol against both outside and participant attacks. Further more, we have proved its security in detail.
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Directory of Open Access Journals (Sweden)
E. M. Griffin
2004-03-01
Full Text Available Thermospheric neutral winds at Kiruna, Sweden (67.4°N, 20.4°E are compared using both direct optical Fabry-Perot Interferometer (FPI measurements and those derived from European incoherent scatter radar (EISCAT measurements. This combination of experimental data sets, both covering well over a solar cycle of data, allows for a unique comparison of the thermospheric meridional component of the neutral wind as observed by different experimental techniques. Uniquely in this study the EISCAT measurements are used to provide winds for comparison using two separate techniques: the most popular method based on the work of Salah and Holt (1974 and the Meridional Wind Model (MWM (Miller et al., 1997 application of servo theory. The balance of forces at this location that produces the observed diurnal pattern are investigated using output from the Coupled Thermosphere and Ionosphere (CTIM numerical model. Along with detailed comparisons from short periods the climatological behaviour of the winds have been investigated for seasonal and solar cycle dependence using the experimental techniques. While there are features which are consistent between the 3 techniques, such as the evidence of the equinoctial asymmetry, there are also significant differences between the techniques both in terms of trends and absolute values. It is clear from this and previous studies that the high-latitude representation of the thermospheric neutral winds from the empirical Horizontal Wind Model (HWM, though improved from earlier versions, lacks accuracy in many conditions. The relative merits of each technique are discussed and while none of the techniques provides the perfect data set to address model performance at high-latitude, one or more needs to be included in future HWM reformulations.
Key words. Meteorology and atmospheric dynamics (thermospheric dynamics, Ionosphere (ionosphere-atmosphere interactions, auroral ionosphere
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Directory of Open Access Journals (Sweden)
E. M. Griffin
2004-03-01
Full Text Available Thermospheric neutral winds at Kiruna, Sweden (67.4°N, 20.4°E are compared using both direct optical Fabry-Perot Interferometer (FPI measurements and those derived from European incoherent scatter radar (EISCAT measurements. This combination of experimental data sets, both covering well over a solar cycle of data, allows for a unique comparison of the thermospheric meridional component of the neutral wind as observed by different experimental techniques. Uniquely in this study the EISCAT measurements are used to provide winds for comparison using two separate techniques: the most popular method based on the work of Salah and Holt (1974 and the Meridional Wind Model (MWM (Miller et al., 1997 application of servo theory. The balance of forces at this location that produces the observed diurnal pattern are investigated using output from the Coupled Thermosphere and Ionosphere (CTIM numerical model. Along with detailed comparisons from short periods the climatological behaviour of the winds have been investigated for seasonal and solar cycle dependence using the experimental techniques. While there are features which are consistent between the 3 techniques, such as the evidence of the equinoctial asymmetry, there are also significant differences between the techniques both in terms of trends and absolute values. It is clear from this and previous studies that the high-latitude representation of the thermospheric neutral winds from the empirical Horizontal Wind Model (HWM, though improved from earlier versions, lacks accuracy in many conditions. The relative merits of each technique are discussed and while none of the techniques provides the perfect data set to address model performance at high-latitude, one or more needs to be included in future HWM reformulations. Key words. Meteorology and atmospheric dynamics (thermospheric dynamics, Ionosphere (ionosphere-atmosphere interactions, auroral ionosphere
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Zwetsloot, G.I.J.M.
2014-01-01
This paper addresses how organisations can use OSH performance indicators. This is an important way to mainstream OSH into business management. Key performance indicators (KPIs) should provide objective data on the OSH situation. It is often said that ‘what gets measured gets managed’. Without
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Differential phase-shift keying and channel equalization in free space optical communication system
Zhang, Dai; Hao, Shiqi; Zhao, Qingsong; Wan, Xiongfeng; Xu, Chenlu
2018-01-01
We present the performance benefits of differential phase-shift keying (DPSK) modulation in eliminating influence from atmospheric turbulence, especially for coherent free space optical (FSO) communication with a high communication rate. Analytic expression of detected signal is derived, based on which, homodyne detection efficiency is calculated to indicate the performance of wavefront compensation. Considered laser pulses always suffer from atmospheric scattering effect by clouds, intersymbol interference (ISI) in high-speed FSO communication link is analyzed. Correspondingly, the channel equalization method of a binormalized modified constant modulus algorithm based on set-membership filtering (SM-BNMCMA) is proposed to solve the ISI problem. Finally, through the comparison with existing channel equalization methods, its performance benefits of both ISI elimination and convergence speed are verified. The research findings have theoretical significance in a high-speed FSO communication system.
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Privacy for Key-Trees with Adaptive Adversaries
Beye, M.; Veugen, P.J.M.
2011-01-01
Hash-lock authentication protocols for Radio Frequency IDentification (RFID) tags incur heavy search on the server. Key-trees have been proposed as a way to reduce search times, but because partial keys in such trees are shared, key compromise affects several tags. Butty´an [3] and Beye and Veugen
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Anonymity for key-trees with adaptive adversaries
Beye, M.; Veugen, P.J.M.
2012-01-01
Hash-lock authentication protocols for Radio Frequency IDentification (RFID) tags incur heavy search on the server. Key-trees have been proposed as a way to reduce search times, but because partial keys in such trees are shared, key compromise affects several tags. Buttyán [4] and Beye and Veugen
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Secure image retrieval with multiple keys
Liang, Haihua; Zhang, Xinpeng; Wei, Qiuhan; Cheng, Hang
2018-03-01
This article proposes a secure image retrieval scheme under a multiuser scenario. In this scheme, the owner first encrypts and uploads images and their corresponding features to the cloud; then, the user submits the encrypted feature of the query image to the cloud; next, the cloud compares the encrypted features and returns encrypted images with similar content to the user. To find the nearest neighbor in the encrypted features, an encryption with multiple keys is proposed, in which the query feature of each user is encrypted by his/her own key. To improve the key security and space utilization, global optimization and Gaussian distribution are, respectively, employed to generate multiple keys. The experiments show that the proposed encryption can provide effective and secure image retrieval for each user and ensure confidentiality of the query feature of each user.
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Efficient key management for cryptographically enforced access control
Zych, Anna; Petkovic, Milan; Jonker, Willem
Cryptographic enforcement of access control mechanisms relies on encrypting protected data with the keys stored by authorized users. This approach poses the problem of the distribution of secret keys. In this paper, a key management scheme is presented where each user stores a single key and is
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An SSH key management system: easing the pain of managing key/user/account associations
Arkhipkin, D.; Betts, W.; Lauret, J.; Shiryaev, A.
2008-07-01
Cyber security requirements for secure access to computing facilities often call for access controls via gatekeepers and the use of two-factor authentication. Using SSH keys to satisfy the two factor authentication requirement has introduced a potentially challenging task of managing the keys and their associations with individual users and user accounts. Approaches for a facility with the simple model of one remote user corresponding to one local user would not work at facilities that require a many-to-many mapping between users and accounts on multiple systems. We will present an SSH key management system we developed, tested and deployed to address the many-to-many dilemma in the environment of the STAR experiment. We will explain its use in an online computing context and explain how it makes possible the management and tracing of group account access spread over many sub-system components (data acquisition, slow controls, trigger, detector instrumentation, etc.) without the use of shared passwords for remote logins.
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An SSH key management system: easing the pain of managing key/user/account associations
International Nuclear Information System (INIS)
Arkhipkin, D; Shiryaev, A; Betts, W; Lauret, J
2008-01-01
Cyber security requirements for secure access to computing facilities often call for access controls via gatekeepers and the use of two-factor authentication. Using SSH keys to satisfy the two factor authentication requirement has introduced a potentially challenging task of managing the keys and their associations with individual users and user accounts. Approaches for a facility with the simple model of one remote user corresponding to one local user would not work at facilities that require a many-to-many mapping between users and accounts on multiple systems. We will present an SSH key management system we developed, tested and deployed to address the many-to-many dilemma in the environment of the STAR experiment. We will explain its use in an online computing context and explain how it makes possible the management and tracing of group account access spread over many sub-system components (data acquisition, slow controls, trigger, detector instrumentation, etc.) without the use of shared passwords for remote logins
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Nickel exposure from keys: alternatives for protection and prevention.
Hamann, Dathan; Scheman, Andrew J; Jacob, Sharon E
2013-01-01
Keys are an important exposure source of metal allergens to consumers and confer a significant problem for nickel-allergic individuals because of repeated daily use. The aims of this study were to investigate the frequency of nickel and cobalt release in keys and to consider the effectiveness of coatings for preventing metallic allergen release from common metal allergen-releasing keys. Keys from a variety of common stores were nickel and cobalt spot tested. Nickel-releasing keys were coated with enamel sprays, subjected to a use test, and retested to assess for metal allergen release. Of 55 tested keys, 80% showed a strong positive result to the nickel spot test. None of the tested keys exhibited cobalt release. No keys initially released nickel after enamel coatings. Key coatings chipped at the portion inserted into a lock after 30 insertions, and keys were found to release nickel. The handle of the key was not found to release nickel after 60 insertions. Nickel release from keys is very common; nickel-allergic consumers should consider purchasing keys that do not release nickel (eg, brass, anodized). Enamel coating may be useful in protecting nickel-sensitive individuals from their keys but cannot consistently prevent nickel-release from portions used frequently.
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Zhao, Tieyu; Ran, Qiwen; Yuan, Lin; Chi, Yingying; Ma, Jing
2016-08-01
A novel image encryption system based on double random phase encoding (DRPE) and RSA public-key algorithm is proposed. The main characteristic of the system is that each encryption process produces a new decryption key (even for the same plaintext), thus the encryption system conforms to the feature of the one-time pad (OTP) cryptography. The other characteristic of the system is the use of fingerprint key. Only with the rightful authorization will the true decryption be obtained, otherwise the decryption will result in noisy images. So the proposed system can be used to determine whether the ciphertext is falsified by attackers. In addition, the system conforms to the basic agreement of asymmetric cryptosystem (ACS) due to the combination with the RSA public-key algorithm. The simulation results show that the encryption scheme has high robustness against the existing attacks.
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Formal Analysis of Key Integrity in PKCS#11
Falcone, Andrea; Focardi, Riccardo
PKCS#11 is a standard API to cryptographic devices such as smarcards, hardware security modules and usb crypto-tokens. Though widely adopted, this API has been shown to be prone to attacks in which a malicious user gains access to the sensitive keys stored in the devices. In 2008, Delaune, Kremer and Steel proposed a model to formally reason on this kind of attacks. We extend this model to also describe flaws that are based on integrity violations of the stored keys. In particular, we consider scenarios in which a malicious overwriting of keys might fool honest users into using attacker's own keys, while performing sensitive operations. We further enrich the model with a trusted key mechanism ensuring that only controlled, non-tampered keys are used in cryptographic operations, and we show how this modified API prevents the above mentioned key-replacement attacks.
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DEFF Research Database (Denmark)
Hansen, Klaus
This report gives a summary of the present information on the behaviour of vertical keyed shear joints in large panel structures. An attemp is made to outline the implications which this information might have on the analysis and design of a complete wall. The publications also gives a short...
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Exploration of the Future – a Key to Sustainable Development
Directory of Open Access Journals (Sweden)
Vatroslav Zovko
2013-01-01
Full Text Available Throughout the history people were fascinated and curious about the future. The future was, and still is seen as a key for prosperous development in all aspects of the society. As such, new discipline is developed – future studies.This paper discusses the discipline of future studies and its role in the society and science. Future studies are analyzed in the context of sustainable development. It is argued that future studies and sustainable development are complementary in nature. Based on analysis of most developed countries in the world, that spend the greatest portion of their budget on research, development and science in comparison to the rest of the world, there is a conclusive link between investments in research, development and science, and the recognition of the importance of thinking about the future. Those countries started to formalize their future orientation in many respected research centres and universities through their educational programs and research. That situation poses the need for other, less well off countries, to follow up.
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Directory of Open Access Journals (Sweden)
Hong-Ying Jian
2018-02-01
Full Text Available Rosa chinensis var. spontanea, an endemic and endangered plant of China, is one of the key ancestors of modern roses and a source for famous traditional Chinese medicines against female diseases, such as irregular menses and dysmenorrhea. In this study, the complete chloroplast (cp genome of R. chinensis var. spontanea was sequenced, analyzed, and compared to congeneric species. The cp genome of R. chinensis var. spontanea is a typical quadripartite circular molecule of 156,590 bp in length, including one large single copy (LSC region of 85,910 bp and one small single copy (SSC region of 18,762 bp, separated by two inverted repeat (IR regions of 25,959 bp. The GC content of the whole genome is 37.2%, while that of LSC, SSC, and IR is 42.8%, 35.2% and 31.2%, respectively. The genome encodes 129 genes, including 84 protein-coding genes (PCGs, 37 transfer RNA (tRNA genes, and eight ribosomal RNA (rRNA genes. Seventeen genes in the IR regions were found to be duplicated. Thirty-three forward and five inverted repeats were detected in the cp genome of R. chinensis var. spontanea. The genome is rich in SSRs. In total, 85 SSRs were detected. A genome comparison revealed that IR contraction might be the reason for the relatively smaller cp genome size of R. chinensis var. spontanea compared to other congeneric species. Sequence analysis revealed that the LSC and SSC regions were more divergent than the IR regions within the genus Rosa and that a higher divergence occurred in non-coding regions than in coding regions. A phylogenetic analysis showed that the sampled species of the genus Rosa formed a monophyletic clade and that R. chinensis var. spontanea shared a more recent ancestor with R. lichiangensis of the section Synstylae than with R. odorata var. gigantea of the section Chinenses. This information will be useful for the conservation genetics of R. chinensis var. spontanea and for the phylogenetic study of the genus Rosa, and it might also
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Jian, Hong-Ying; Zhang, Yong-Hong; Yan, Hui-Jun; Qiu, Xian-Qin; Wang, Qi-Gang; Li, Shu-Bin; Zhang, Shu-Dong
2018-02-12
Rosa chinensis var. spontanea , an endemic and endangered plant of China, is one of the key ancestors of modern roses and a source for famous traditional Chinese medicines against female diseases, such as irregular menses and dysmenorrhea. In this study, the complete chloroplast (cp) genome of R. chinensis var. spontanea was sequenced, analyzed, and compared to congeneric species. The cp genome of R. chinensis var. spontanea is a typical quadripartite circular molecule of 156,590 bp in length, including one large single copy (LSC) region of 85,910 bp and one small single copy (SSC) region of 18,762 bp, separated by two inverted repeat (IR) regions of 25,959 bp. The GC content of the whole genome is 37.2%, while that of LSC, SSC, and IR is 42.8%, 35.2% and 31.2%, respectively. The genome encodes 129 genes, including 84 protein-coding genes (PCGs), 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes. Seventeen genes in the IR regions were found to be duplicated. Thirty-three forward and five inverted repeats were detected in the cp genome of R. chinensis var. spontanea. The genome is rich in SSRs. In total, 85 SSRs were detected. A genome comparison revealed that IR contraction might be the reason for the relatively smaller cp genome size of R. chinensis var. spontanea compared to other congeneric species. Sequence analysis revealed that the LSC and SSC regions were more divergent than the IR regions within the genus Rosa and that a higher divergence occurred in non-coding regions than in coding regions. A phylogenetic analysis showed that the sampled species of the genus Rosa formed a monophyletic clade and that R. chinensis var. s pontanea shared a more recent ancestor with R. lichiangensis of the section Synstylae than with R. odorata var. gigantea of the section Chinenses . This information will be useful for the conservation genetics of R. chinensis var. spontanea and for the phylogenetic study of the genus Rosa , and it might also facilitate the
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Nickel exposure from keys: a Brazilian issue.
Suzuki, Nathalie Mie; Duarte, Ida Alzira Gomes; Hafner, Mariana de Figueiredo Silva; Lazzarini, Rosana
2017-01-01
Keys are a significant source of exposure to metal allergens and can be a relevant problem for nickel-allergic individuals. This study aimed to perform nickel and cobalt spot testing among the 5 most common Brazilian brands of keys. Among the tested keys, 100% showed positive result to nickel spot test, 83,3% presented strong positive reaction. 50% exhibited cobalt release as well. Nickel release from keys is very common in our country and may cause a negative impact on sensitized individual's quality of life. Study's results highlight the importance of establishing directives to regulate nickel release in Brazil.
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Enhanced diffie-hellman algorithm for reliable key exchange
Aryan; Kumar, Chaithanya; Vincent, P. M. Durai Raj
2017-11-01
The Diffie -Hellman is one of the first public-key procedure and is a certain way of exchanging the cryptographic keys securely. This concept was introduced by Ralph Markel and it is named after Whitfield Diffie and Martin Hellman. Sender and Receiver make a common secret key in Diffie-Hellman algorithm and then they start communicating with each other over the public channel which is known to everyone. A number of internet services are secured by Diffie -Hellman. In Public key cryptosystem, the sender has to trust while receiving the public key of the receiver and vice-versa and this is the challenge of public key cryptosystem. Man-in-the-Middle attack is very much possible on the existing Diffie-Hellman algorithm. In man-in-the-middle attack, the attacker exists in the public channel, the attacker receives the public key of both sender and receiver and sends public keys to sender and receiver which is generated by his own. This is how man-in-the-middle attack is possible on Diffie-Hellman algorithm. Denial of service attack is another attack which is found common on Diffie-Hellman. In this attack, the attacker tries to stop the communication happening between sender and receiver and attacker can do this by deleting messages or by confusing the parties with miscommunication. Some more attacks like Insider attack, Outsider attack, etc are possible on Diffie-Hellman. To reduce the possibility of attacks on Diffie-Hellman algorithm, we have enhanced the Diffie-Hellman algorithm to a next level. In this paper, we are extending the Diffie -Hellman algorithm by using the concept of the Diffie -Hellman algorithm to get a stronger secret key and that secret key is further exchanged between the sender and the receiver so that for each message, a new secret shared key would be generated. The second secret key will be generated by taking primitive root of the first secret key.
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Selecting numerical scales for pairwise comparisons
International Nuclear Information System (INIS)
Elliott, Michael A.
2010-01-01
It is often desirable in decision analysis problems to elicit from an individual the rankings of a population of attributes according to the individual's preference and to understand the degree to which each attribute is preferred to the others. A common method for obtaining this information involves the use of pairwise comparisons, which allows an analyst to convert subjective expressions of preference between two attributes into numerical values indicating preferences across the entire population of attributes. Key to the use of pairwise comparisons is the underlying numerical scale that is used to convert subjective linguistic expressions of preference into numerical values. This scale represents the psychological manner in which individuals perceive increments of preference among abstract attributes and it has important implications about the distribution and consistency of an individual's preferences. Three popular scale types, the traditional integer scales, balanced scales and power scales are examined. Results of a study of 64 individuals responding to a hypothetical decision problem show that none of these scales can accurately capture the preferences of all individuals. A study of three individuals working on an actual engineering decision problem involving the design of a decay heat removal system for a nuclear fission reactor show that the choice of scale can affect the preferred decision. It is concluded that applications of pairwise comparisons would benefit from permitting participants to choose the scale that best models their own particular way of thinking about the relative preference of attributes.
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Optimizing Key Updates in Sensor Networks
DEFF Research Database (Denmark)
Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming
2011-01-01
Sensor networks offer the advantages of simple and low–resource communication. Nevertheless, security is of particular importance in many cases such as when sensitive data is communicated or tamper-resistance is required. Updating the security keys is one of the key points in security, which...
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Subcarrier multiplexing optical quantum key distribution
International Nuclear Information System (INIS)
Ortigosa-Blanch, A.; Capmany, J.
2006-01-01
We present the physical principles of a quantum key distribution system that opens the possibility of parallel quantum key distribution and, therefore, of a substantial improvement in the bit rate of such systems. Quantum mechanics allows for multiple measurements at different frequencies and thus we exploit this concept by extending the concept of frequency coding to the case where more than one radio-frequency subcarrier is used for independently encoding the bits onto an optical carrier. Taking advantage of subcarrier multiplexing techniques we demonstrate that the bit rate can be greatly improved as parallel key distribution is enabled
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Setting objectives for managing Key deer
Diefenbach, Duane R.; Wagner, Tyler; Stauffer, Glenn E.
2014-01-01
The U.S. Fish and Wildlife Service (FWS) is responsible for the protection and management of Key deer (Odocoileus virginianus clavium) because the species is listed as Endangered under the Endangered Species Act (ESA). The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend. There are a host of actions that could possibly be undertaken to recover the Key deer population, but without a clearly defined problem and stated objectives it can be difficult to compare and evaluate alternative actions. In addition, management goals and the acceptability of alternative management actions are inherently linked to stakeholders, who should be engaged throughout the process of developing a decision framework. The purpose of this project was to engage a representative group of stakeholders to develop a problem statement that captured the management problem the FWS must address with Key deer and identify objectives that, if met, would help solve the problem. In addition, the objectives were organized in a hierarchical manner (i.e., an objectives network) to show how they are linked, and measurable attributes were identified for each objective. We organized a group of people who represented stakeholders interested in and potentially affected by the management of Key deer. These stakeholders included individuals who represented local, state, and federal governments, non-governmental organizations, the general public, and local businesses. This stakeholder group met five full days over the course of an eight-week period to identify objectives that would address the following problem:“As recovery and removal from the Endangered Species list is the purpose of the Endangered Species Act, the U.S. Fish and Wildlife Service needs a management approach that will ensure a sustainable, viable, and healthy Key deer population. Urbanization has affected the behavior and population dynamics of the Key deer and the amount and characteristics
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Comparative analysis as a basic research orientation: Key methodological problems
Directory of Open Access Journals (Sweden)
N P Narbut
2015-12-01
Full Text Available To date, the Sociological Laboratory of the Peoples’ Friendship University of Russia has accumulated a vast experience in the field of cross-cultural studies reflected in the publications based on the results of mass surveys conducted in Moscow, Maikop, Beijing, Guangzhou, Prague, Belgrade, and Pristina. However, these publications mainly focus on the comparisons of the empirical data rather than methodological and technical issues, that is why the aim of this article is to identify key problems of the comparative analysis in cross-cultural studies that become evident only if you conduct an empirical research yourself - from the first step of setting the problem and approving it by all the sides (countries involved to the last step of interpreting and comparing the data obtained. The authors are sure that no sociologist would ever doubt the necessity and importance of comparative analysis in the broadest sense of the word, but at the same time very few are ready to discuss its key methodological challenges and prefer to ignore them completely. We summarize problems of the comparative analysis in sociology as follows: (1 applying research techniques to the sample in another country - both in translating and adapting them to different social realities and worldview (in particular, the problematic status of standardization and qualitative approach; (2 choosing “right” respondents to question and relevant cases (cultures to study; (3 designing the research scheme, i.e. justifying the sequence of steps (what should go first - methodology or techniques; (4 accepting the procedures that are correct within one country for cross-cultural work (whether or not that is an appropriate choice.
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Wang, Shuang; Yin, Zhen-Qiang; Chau, H. F.; Chen, Wei; Wang, Chao; Guo, Guang-Can; Han, Zheng-Fu
2018-04-01
In comparison to qubit-based protocols, qudit-based quantum key distribution ones generally allow two cooperative parties to share unconditionally secure keys under a higher channel noise. However, it is very hard to prepare and measure the required quantum states in qudit-based protocols in general. One exception is the recently proposed highly error tolerant qudit-based protocol known as the Chau15 (Chau 2015 Phys. Rev. A 92 062324). Remarkably, the state preparation and measurement in this protocol can be done relatively easily since the required states are phase encoded almost like the diagonal basis states of a qubit. Here we report the first proof-of-principle demonstration of the Chau15 protocol. One highlight of our experiment is that its post-processing is based on practical one-way manner, while the original proposal in Chau (2015 Phys. Rev. A 92 062324) relies on complicated two-way post-processing, which is a great challenge in experiment. In addition, by manipulating time-bin qudit and measurement with a variable delay interferometer, our realization is extensible to qudit with high-dimensionality and confirms the experimental feasibility of the Chau15 protocol.
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The LOFAR Transients Key Science Project
Stappers, B.; Fender, R.; Wijers, R.
2009-01-01
The Transients Key Science Project (TKP) is one of six Key Science Projects of the next generation radio telescope LOFAR. Its aim is the study of transient and variable low-frequency radio sources with an extremely broad science case ranging from relativistic jet sources to pulsars, exoplanets,
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Ten Key Steps to Developing a Programme of University Mentoring for Newly Enrolled Students
Directory of Open Access Journals (Sweden)
Raquel Casado-Muñoz
2015-05-01
Full Text Available Peer mentoring or tutoring is an educational guidance method that is growing in universities around the world. Directed at the integration of students over the first year of university studies, it is based on the support and guidance that a more experienced student offers to a recently enrolled fellow student. It is a recent process in Spain which started a little over a decade ago, but each course brings more experiences. This article, derived from research, seeks to identify a series of key steps and ideas to implement this type of programme. The summary of the proposals stems from three main sources: a the experience and assessment of the Mentoring Programme at the University of Burgos; b the review of the peer mentoring programs implemented at 35 Spanish universities; and c the review, comparison and adaptation of formal mentoring to the university according to Perrone (2003. The outcomes may be especially useful for those universities that wish to start mentoring programmes, and as a source of reflection and comparison for those with greater experience. We believe that special attention should be given on increasing and improving participation in the mentoring of newly enrolled students and on monitoring and assessing the whole process.
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Coherent one-way quantum key distribution
Stucki, Damien; Fasel, Sylvain; Gisin, Nicolas; Thoma, Yann; Zbinden, Hugo
2007-05-01
Quantum Key Distribution (QKD) consists in the exchange of a secrete key between two distant points [1]. Even if quantum key distribution systems exist and commercial systems are reaching the market [2], there are still improvements to be made: simplify the construction of the system; increase the secret key rate. To this end, we present a new protocol for QKD tailored to work with weak coherent pulses and at high bit rates [3]. The advantages of this system are that the setup is experimentally simple and it is tolerant to reduced interference visibility and to photon number splitting attacks, thus resulting in a high efficiency in terms of distilled secret bits per qubit. After having successfully tested the feasibility of the system [3], we are currently developing a fully integrated and automated prototype within the SECOQC project [4]. We present the latest results using the prototype. We also discuss the issue of the photon detection, which still remains the bottleneck for QKD.
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Development of a primary method for the determination of iron in serum
International Nuclear Information System (INIS)
Palos, Marie; Del Castillo Busto, Maria Estela; Fisicaro, Paola; Vaslin-Reimann, Sophie; Hattchouel, Jean-Marc; Pannier, Florence
2015-01-01
This work presents the development of a reference method by ICP-MS for the determination of iron in serum. To ensure the metrological traceability of the results, isotope dilution associated with ICP-MS (ID-ICP-MS) has been applied, which has the potential to be a primary measurement procedure. Method validation has been demonstrated through the use of a certified reference material (SRM 1598a) and the participation in an international comparison between National Metrology Institutes (BIPM-CCQM K107). The validated method is now available to support clinical laboratories in the evaluation of their measurement capabilities and for quality assurance and quality control programs. In fact, this ID-ICP-MS method can be used to certify reference materials or to assign reference values to samples used in proficiency testing schemes. The feasibility has been tested on two unknown samples, i.e. BCR"R -637, IRMM sample and an ANSM B17 sample (a material distributed during a National Quality Control program). (authors)
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International Nuclear Information System (INIS)
Hilario, Katia Aparecida Fonseca
2002-01-01
In the present work alternative procedures have been developed for standardization of radionuclides with double decay, β - β + / electron capture using the 4πβ-γ coincidence technique, applying different systems. Two 4πβ-γ coincidence systems were used: one with a 4π gas-flow proportional counter coupled to a pair of NaI(Tl) scintillators and the other one with the same type of proportional counter coupled to HPGe detector. The radionuclides selected for this standardization, due to great interest in nuclear medicine, detector calibration and industrial radiography, were 192 Ir, 152 Eu and 186 Re. The first and the second were part of international comparisons sponsored by the Bureau International des Poids et Mesures (BIPM), France, who supplied the radioactive solution. For 186 Re, the gamma-ray emission probability per decay was measured by means REGe spectrometer system, previously calibrated with standard ampoules. All the uncertainties involved were treated rigorously, by means of covariance analysis. (author)
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The Brazilian National Intercomparison Program (PNI/IRD/CNEN): evaluation of 15 years of data
International Nuclear Information System (INIS)
Tauhata, Luiz; Vianna, Maria Elizabeth Couto M.; Oliveira, Antonio Eduardo de; Ferreira, Ana Cristina; Braganca, Maura Julia C.; Clain, Almir Faria; Quelvia de Faria, Rute
2006-01-01
The Instituto de Radioprotecao e Dosimetria has been coordinating the National Intercomparison Program (PNI) for 15 years, from 1991 to 2005. The objective is to evaluate the analytical performance of the laboratories in low-level activity concentration radionuclide assays in environmental samples. This work presents an evaluation of PNI data from 42 intercomparison runs, which distributed to 22 Brazilian laboratories 2511 samples evaluating 5768 radionuclide assays involving 32 radionuclides in the period from 1991 to 2004. The laboratory performance was evaluated using the Normalized Standard Deviation used by the U.S. EPA. For comparison aims, the Normalized Deviation, used by BIPM was also applied. Laboratory performance were grouped and evaluated in three periods of 5 years each. The first period shows, an average value of good performance of 71.2%, the second shows an average of 78.6% and the last an average of 82.3%. Performance for each kind of radionuclide is also presented
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Multicomponent reactions provide key molecules for secret communication.
Boukis, Andreas C; Reiter, Kevin; Frölich, Maximiliane; Hofheinz, Dennis; Meier, Michael A R
2018-04-12
A convenient and inherently more secure communication channel for encoding messages via specifically designed molecular keys is introduced by combining advanced encryption standard cryptography with molecular steganography. The necessary molecular keys require large structural diversity, thus suggesting the application of multicomponent reactions. Herein, the Ugi four-component reaction of perfluorinated acids is utilized to establish an exemplary database consisting of 130 commercially available components. Considering all permutations, this combinatorial approach can unambiguously provide 500,000 molecular keys in only one synthetic procedure per key. The molecular keys are transferred nondigitally and concealed by either adsorption onto paper, coffee, tea or sugar as well as by dissolution in a perfume or in blood. Re-isolation and purification from these disguises is simplified by the perfluorinated sidechains of the molecular keys. High resolution tandem mass spectrometry can unequivocally determine the molecular structure and thus the identity of the key for a subsequent decryption of an encoded message.
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Partitioned key-value store with atomic memory operations
Energy Technology Data Exchange (ETDEWEB)
Bent, John M.; Faibish, Sorin; Grider, Gary
2017-02-07
A partitioned key-value store is provided that supports atomic memory operations. A server performs a memory operation in a partitioned key-value store by receiving a request from an application for at least one atomic memory operation, the atomic memory operation comprising a memory address identifier; and, in response to the atomic memory operation, performing one or more of (i) reading a client-side memory location identified by the memory address identifier and storing one or more key-value pairs from the client-side memory location in a local key-value store of the server; and (ii) obtaining one or more key-value pairs from the local key-value store of the server and writing the obtained one or more key-value pairs into the client-side memory location identified by the memory address identifier. The server can perform functions obtained from a client-side memory location and return a result to the client using one or more of the atomic memory operations.
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Secret key distillation from shielded two-qubit states
International Nuclear Information System (INIS)
Bae, Joonwoo
2010-01-01
The quantum states corresponding to a secret key are characterized using the so-called private states, where the key part consisting of a secret key is shielded by the additional systems. Based on the construction, it was shown that a secret key can be distilled from bound entangled states. In this work, I consider the shielded two-qubit states in a key-distillation scenario and derive the conditions under which a secret key can be distilled using the recurrence protocol or the two-way classical distillation, advantage distillation together with one-way postprocessing. From the security conditions, it is shown that a secret key can be distilled from bound entangled states in a much wider range. In addition, I consider the case that in which white noise is added to quantum states and show that the classical distillation protocol still works despite a certain amount of noise although the recurrence protocol does not.
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Key to marine arthropod larvae
Directory of Open Access Journals (Sweden)
John A. Fornshell
2012-03-01
Full Text Available The scope of this key is restricted to the larvae of marine arthropods. The key is based solely on their morphology, patterns of body segmentation, numbers of appendages, and mode of locomotion. An effort has been made to treat all traditionally named larval forms, both planktonic and benthic. It is intended that this key be useful for a researcher working with archived museum specimens and therefore, does not include habitat information as a identifying trait, even though this information is usually available in the archived records. Within the phylum Arthropoda there are two sub-phyla and eleven classes having larval stages in the marineenvironment. Where feasible the original names of the various larval types have been used. Because this nomenclature is less commonly used today compared to the past, the more recent taxonomic affinities are included in parentheses after the original larval name. The key includes the following thirty-four larvae: Branchhiopoda nauplii; Cephalocarida nauplii; Mystacocarida nauplii; trilobite larva; protonymphon; hexapod larvae; Remipedia nauplii; nauplius - Y larvae; Cirripedia nauplii; Ascothoracida nauplii; Ostracoda nauplii; Euphausiacea nauplii; Penaeidea nauplii; Cyclopoida nauplii; Calanoida nauplii; Harpacticoida nauplii;Polyarthra nauplii; cypris larva; eryonecius larva; cypris-Y larva; elapthocaris larvae; mysis larvae; lucifer zoea; acetes zoea; acanthosoma larva; phyllosoma; antizoea larva; anomuran zoea; brachyuran zoea; calyptopis larvae; furcilia larva; crytopia larva; puerulus larva; alima larva.
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[Key informers. When and How?].
Martín González, R
2009-03-01
When information obtained through duly designed and developed studies is not available, the solution to certain problems that affect the population or that respond to certain questions may be approached by using the information and experience provided by the so-called key informer. The key informer is defined as a person who is in contact with the community or with the problem to be studied, who is considered to have good knowledge of the situation and therefore who is considered an expert. The search for consensus is the basis to obtain information through the key informers. The techniques used have different characteristics based on whether the experts chosen meet together or not, whether they are guided or not, whether they interact with each other or not. These techniques include the survey, the Delphi technique, the nominal group technique, brainwriting, brainstorming, the Phillips 66 technique, the 6-3-5 technique, the community forum and the community impressions technique. Information provided by key informers through the search for consensus is relevant when this is not available or cannot be obtained by other methods. It has permitted the analysis of the existing neurological care model, elaboration of recommendations on visit times for the out-patient neurological care, and the elaboration of guidelines and recommendations for the management of prevalent neurological problems.
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a Performance Comparison of Feature Detectors for Planetary Rover Mapping and Localization
Wan, W.; Peng, M.; Xing, Y.; Wang, Y.; Liu, Z.; Di, K.; Teng, B.; Mao, X.; Zhao, Q.; Xin, X.; Jia, M.
2017-07-01
Feature detection and matching are key techniques in computer vision and robotics, and have been successfully implemented in many fields. So far there is no performance comparison of feature detectors and matching methods for planetary mapping and rover localization using rover stereo images. In this research, we present a comprehensive evaluation and comparison of six feature detectors, including Moravec, Förstner, Harris, FAST, SIFT and SURF, aiming for optimal implementation of feature-based matching in planetary surface environment. To facilitate quantitative analysis, a series of evaluation criteria, including distribution evenness of matched points, coverage of detected points, and feature matching accuracy, are developed in the research. In order to perform exhaustive evaluation, stereo images, simulated under different baseline, pitch angle, and interval of adjacent rover locations, are taken as experimental data source. The comparison results show that SIFT offers the best overall performance, especially it is less sensitive to changes of image taken at adjacent locations.
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A PERFORMANCE COMPARISON OF FEATURE DETECTORS FOR PLANETARY ROVER MAPPING AND LOCALIZATION
Directory of Open Access Journals (Sweden)
W. Wan
2017-07-01
Full Text Available Feature detection and matching are key techniques in computer vision and robotics, and have been successfully implemented in many fields. So far there is no performance comparison of feature detectors and matching methods for planetary mapping and rover localization using rover stereo images. In this research, we present a comprehensive evaluation and comparison of six feature detectors, including Moravec, Förstner, Harris, FAST, SIFT and SURF, aiming for optimal implementation of feature-based matching in planetary surface environment. To facilitate quantitative analysis, a series of evaluation criteria, including distribution evenness of matched points, coverage of detected points, and feature matching accuracy, are developed in the research. In order to perform exhaustive evaluation, stereo images, simulated under different baseline, pitch angle, and interval of adjacent rover locations, are taken as experimental data source. The comparison results show that SIFT offers the best overall performance, especially it is less sensitive to changes of image taken at adjacent locations.
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Workplace Mental Health Training in Health Care: Key Ingredients of Implementation.
Moll, Sandra E; VandenBussche, Jessica; Brooks, Katelyn; Kirsh, Bonnie; Stuart, Heather; Patten, Scott; MacDermid, Joy C
2018-01-01
Despite growing awareness of the importance of workplace mental health training and an increasing number of educational resources, there is a gap in knowledge regarding what shapes training effectiveness. The purpose of this study was to compare and describe the active ingredients of 2 workplace mental health education programs for health care workers. Within the context of a randomized clinical trial, a multimethod process evaluation was conducted to explore key process elements shaping implementation outcomes: the innovation, service recipients, service providers, and the organizational context. Data collection included descriptive statistics regarding program participation, postprogram interviews with a purposive sample of 18 service recipients, 182 responses to open-ended questions on postgroup and follow-up surveys, and field journal reflections on the process of implementation. Data analysis was informed by an interpretive description approach, using a process evaluation framework to categorize responses from all data sources, followed by within and cross-case comparison of data from both programs. Five key forces shaped the implementation and perceived outcomes of both programs: a contact-based education approach, information tailored to the workplace context, varied stakeholder perspectives, sufficient time to integrate and apply learning, and organizational support. The Beyond Silence program provided more opportunity for contact-based education, health care-specific content, and in-depth discussion of diverse perspectives. To increase mental health literacy and reduce stigma, workplace training should be based on best practice principles of contact-based education, with contextually relevant examples and support from all levels of the organization.
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Key Working for Families with Young Disabled Children
Directory of Open Access Journals (Sweden)
Bernie Carter
2011-01-01
Full Text Available For families with a disabled child, the usual challenges of family life can be further complicated by the need to access a wide range of services provided by a plethora of professionals and agencies. Key working aims to support children and their families in navigating these complexities ensuring easy access to relevant, high quality, and coordinated care. The aim of this paper is to explore the key worker role in relation to “being a key worker” and “having a key worker”. The data within this paper draw on a larger evaluation study of the Blackpool Early Support Pilot Programme. The qualitative study used an appreciative and narrative approach and utilised mixed methods (interviews, surveys and a nominal group workshop. Data were collected from 43 participants (parents, key workers, and other stakeholders. All stakeholders who had been involved with the service were invited to participate. In the paper we present and discuss the ways in which key working made a difference to the lives of children and their families. We also consider how key working transformed the perspectives of the key workers creating a deeper and richer understanding of family lives and the ways in which other disciplines and agencies worked. Key working contributed to the shift to a much more family-centred approach, and enhanced communication and information sharing between professionals and agencies improved. This resulted in families feeling more informed. Key workers acted in an entrepreneurial fashion, forging new relationships with families and between families and other stakeholders. Parents of young disabled children and their service providers benefited from key working. Much of the benefit accrued came from strong, relational, and social-professional networking which facilitated the embedding of new ways of working into everyday practice. Using an appreciative inquiry approach provided an effective and relevant way of engaging with parents, professionals
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Once again on Interregional, International and Cross-age Comparison of Unemployment
Gennadi Kazakevitch
2003-01-01
Any discussion on unemployment is never restricted with the data on unemployment only. Unemployment is linked to several key indicators such as number of employed, active population and participation rate. As we often see, increase in unemployment occurs simultaneously with increase in the number of jobs, if participation rate increases at the same time. This makes doubtful any simplistic interregional, international, inter-temporal or cross-age comparison of unemployment data taken in isolat...
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Key World Energy Statistics 2013
Energy Technology Data Exchange (ETDEWEB)
NONE
2013-08-01
The IEA produced its first handy, pocket-sized summary of key energy data in 1997 and every year since then it has been more and more successful. Key World Energy Statistics contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts.
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International Nuclear Information System (INIS)
1984-03-01
On January 5, 1984 contaminated water overflowed a storage reservoir at the Key Lake uranium mill onto the ice on a neighboring lake, into a muskeg area and onto a road. Outflow continued for two days, partially undercutting a retaining dyke. This report concludes the spill was the result of poor operation by the Key Lake Mining Corp.. The environmental impact will be minimal after cleanup. Improvements can be made in the regulatory process, and it is necessary to prepare for possible future mishaps
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Towards understanding the known-key security of block ciphers
DEFF Research Database (Denmark)
Andreeva, Elena; Bogdanov, Andrey; Mennink, Bart
2014-01-01
ciphers based on ideal components such as random permutations and random functions as well as propose new generic known-key attacks on generalized Feistel ciphers. We introduce the notion of known-key indifferentiability to capture the security of such block ciphers under a known key. To show its...... meaningfulness, we prove that the known-key attacks on block ciphers with ideal primitives to date violate security under known-key indifferentiability. On the other hand, to demonstrate its constructiveness, we prove the balanced Feistel cipher with random functions and the multiple Even-Mansour cipher...... with random permutations known-key indifferentiable for a sufficient number of rounds. We note that known-key indifferentiability is more quickly and tightly attained by multiple Even-Mansour which puts it forward as a construction provably secure against known-key attacks....
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Establishing Key Performance Indicators : Case company X
Singh, Jatinder
2015-01-01
The key performance indicators serve as the navigational tools for a business organization to monitor its performance. They enable the management team to take real time decisions to keep organization’s resources aligned to its business strategy to accomplish its strategic objec-tives. This research was conducted to analyse the process of establishing successful key per-formance indicators for a business organization. The research was conducted to recommend key performance indicators developme...
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International Nuclear Information System (INIS)
Mueller, W.H.; Schneider, B.; Staeuble, J.
1984-01-01
This reference manual provides users of the NAGRADATA system with comprehensive keys to the coding/decoding of geological and technical information to be stored in or retreaved from the databank. Emphasis has been placed on input data coding. When data is retreaved the translation into plain language of stored coded information is done automatically by computer. Three keys each, list the complete set of currently defined codes for the NAGRADATA system, namely codes with appropriate definitions, arranged: 1. according to subject matter (thematically) 2. the codes listed alphabetically and 3. the definitions listed alphabetically. Additional explanation is provided for the proper application of the codes and the logic behind the creation of new codes to be used within the NAGRADATA system. NAGRADATA makes use of codes instead of plain language for data storage; this offers the following advantages: speed of data processing, mainly data retrieval, economies of storage memory requirements, the standardisation of terminology. The nature of this thesaurian type 'key to codes' makes it impossible to either establish a final form or to cover the entire spectrum of requirements. Therefore, this first issue of codes to NAGRADATA must be considered to represent the current state of progress of a living system and future editions will be issued in a loose leave ringbook system which can be updated by an organised (updating) service. (author)
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Perna, Simone; Peroni, Gabriella; Faliva, Milena Anna; Bartolo, Arianna; Naso, Maurizio; Miccono, Alessandra; Rondanelli, Mariangela
2017-12-01
The aim of this study is to identify the prevalence, assess the metabolic profile, and key differences (versus healthy) in a cohort of subjects with sarcopenia (S) and in sarcopenic obesity (SO) hospitalized elderly. A standardized comprehensive geriatric assessment was performed. We enrolled 639 elderly subjects (196 men, 443 women) with a mean age of 80.90 ± 7.77 years. Analysis of variance and a multinomial logistic regression analysis adjusting for covariates were used to assess the differences between groups. The prevalence of (S) was 12.42% in women and 23.47% in men. (SO) was 8.13% in women and 22.45% in men. Data showed that either groups had a functional impairment (Barthel index 15 mm/h), CPR (>0.50 mg/dl) homocysteine (>12 micromol/l), and hemoglobin (145 mcg/dl) was detected in either cohort (due to inflammation). (SO) had glycemia (>110 mg/dl). Key differences in (S) cohort (versus healthy) were a reduction in functional impairment (p Sarcopenia is closely linked to an increase in the risk of hip-femur fractures, inflammation, edema, and malnutrition. The (SO) subjects seem to benefit from the "obesity paradox."
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Electronic Nicotine Delivery Systems Key Facts Infographic
U.S. Department of Health & Human Services — Explore the Electronic Nicotine Delivery Systems Key Facts Infographic which outlines key facts related to electronic nicotine delivery systems (ENDS), including...
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Directory of Open Access Journals (Sweden)
Zhonge Hou
2018-03-01
Full Text Available Four new species of the genus Gammarus are described and illustrated from Tibetan Plateau. Gammarus altus sp. n. and G. limosus sp. n. are characterized by pereopods III–IV with a few short setae and uropod III with marginal spines accompanied by short setae. Gammarus kangdingensis sp. n. and G. gonggaensis sp. n. are characterized by pereopods III–IV with long straight setae on posterior margins and inner ramus of uropod III 0.4 times as long as outer ramus. Detailed morphological comparisons with related species are discussed. A key to 15 Gammarus species from the Tibetan Plateau and a map of their distributions are provided.
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2010-04-19
... GENERAL SERVICES ADMINISTRATION [Wildlife Order 187; 4-D-FL-1218] Public Buildings Service; Key Largo Beacon Annex Site; Key Largo, FL; Transfer of Property Pursuant to section 2 of Public Law 537, 80th Congress, approved May 19, 1948 (16 U.S.C. 667c), notice is hereby given that: 1. The General...
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DEFF Research Database (Denmark)
Hussain, M. Azhar; Siersbæk, Nikolaj; Østerdal, Lars Peter
How did the financial crisis affect population welfare in EU member states in key dimensions such as income, health, and education? Using EU-SILC data, we seek to answer this question by way of first order dominance comparisons between countries and over time. The novel feature of our study...... is that we perform welfare comparisons on the basis of multi-level multidimensional ordinal data. We nd that the countries most often dominated are southern and eastern European member states, and the dominant countries are mostly northern and western European member states. However, for most country...
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... Submit What's this? Submit Button Key Facts About Tularemia Recommend on Facebook Tweet Share Compartir This fact ... and Prevention (CDC) Tularemia Web site . What is Tularemia? Tularemia is a potentially serious illness that occurs ...
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International Nuclear Information System (INIS)
Glattes, G.
1985-01-01
Aspects of project financing for the share of the Canadian subsidiary of Uranerzbergbau-GmbH, Bonn, in the uranium mining and milling facility at Key Lake, Saskatchewan, by a Canadian bank syndicate. (orig.) [de
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Synchronization in Quantum Key Distribution Systems
Directory of Open Access Journals (Sweden)
Anton Pljonkin
2017-10-01
Full Text Available In the description of quantum key distribution systems, much attention is paid to the operation of quantum cryptography protocols. The main problem is the insufficient study of the synchronization process of quantum key distribution systems. This paper contains a general description of quantum cryptography principles. A two-line fiber-optic quantum key distribution system with phase coding of photon states in transceiver and coding station synchronization mode was examined. A quantum key distribution system was built on the basis of the scheme with automatic compensation of polarization mode distortions. Single-photon avalanche diodes were used as optical radiation detecting devices. It was estimated how the parameters used in quantum key distribution systems of optical detectors affect the detection of the time frame with attenuated optical pulse in synchronization mode with respect to its probabilistic and time-domain characteristics. A design method was given for the process that detects the time frame that includes an optical pulse during synchronization. This paper describes the main quantum communication channel attack methods by removing a portion of optical emission. This paper describes the developed synchronization algorithm that takes into account the time required to restore the photodetector’s operation state after the photon has been registered during synchronization. The computer simulation results of the developed synchronization algorithm were analyzed. The efficiency of the developed algorithm with respect to synchronization process protection from unauthorized gathering of optical emission is demonstrated herein.
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Multi-country comparisons of energy performance: The index decomposition analysis approach
International Nuclear Information System (INIS)
Ang, B.W.; Xu, X.Y.; Su, Bin
2015-01-01
Index decomposition analysis (IDA) is a popular tool for studying changes in energy consumption over time in a country or region. This specific application of IDA, which may be called temporal decomposition analysis, has been extended by researchers and analysts to study variations in energy consumption or energy efficiency between countries or regions, i.e. spatial decomposition analysis. In spatial decomposition analysis, the main objective is often to understand the relative contributions of overall activity level, activity structure, and energy intensity in explaining differences in total energy consumption between two countries or regions. We review the literature of spatial decomposition analysis, investigate the methodological issues, and propose a spatial decomposition analysis framework for multi-region comparisons. A key feature of the proposed framework is that it passes the circularity test and provides consistent results for multi-region comparisons. A case study in which 30 regions in China are compared and ranked based on their performance in energy consumption is presented. - Highlights: • We conducted cross-regional comparisons of energy consumption using IDA. • We proposed two criteria for IDA method selection in spatial decomposition analysis. • We proposed a new model for regional comparison that passes the circularity test. • Features of the new model are illustrated using the data of 30 regions in China
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Regional metrology organisations and the JCRB
International Nuclear Information System (INIS)
Hetherington, Paul
2004-01-01
In 1999, National Metrology Institutes (NMIs) from some 39 countries signed the International Committee of Weights and Measures (CIPM) Mutual Recognition Arrangement (MRA) in Paris. The MRA, drawn up by the CIPM, under the authority given to it in the Metre Convention, was in response to requirements of Governments and Regulators to provide a sound technical foundation for trade agreements. Core objectives of the MRA are to allow for the establishment of the degree of equivalence of national measurement standards and to provide for mutual recognition of calibration certificates issued by NMIs. This presentation will detail the evolution of the MRA. Globally, NMIs are affiliated to Regional Metrology Organisations (RMOs). The key role of the RMOs in the MRA process will be discussed along with the structure and objectives of the various RMOs worldwide. The Joint Committee of the RMOs and the BIPM (JCRB) plays a central part in the effective operation of the MRA. Its tasks, membership and output will also be described
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Economic contribution of recreating visitors to the Florida Keys/Key West
Donald B.K. English; Warren Kriesel; Vernon R Leeworthy; Peter C. Wiley
1996-01-01
This report provides estimates of the economic impact that visitors to the Florida Keys have on both the Monroe County and larger South Florida regional economies. Estimates are made for output/sales, income, and employment and include both direct and secondary economic impacts. This report provides the basis for demonstrating the income-producing asset value of the...
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International price comparisons for pharmaceuticals. Measurement and policy issues.
Danzon, P M; Kim, J D
1998-01-01
dropped. When such an approach is taken to the comparison of international drug prices, quite different results from those obtained from less comprehensive comparisons may be obtained. Indeed, a major conclusion of this analysis is that international drug price comparisons are extremely sensitive to choices made about certain key methodological issues, such as sample selection, unit of measurement for price and volume, the relative weight given to consumption patterns in the countries being compared, and the use of exchange rates or purchasing power parities for currency conversion. In particular, the results of this analysis indicate that recent reports suggesting that manufacturer prices in the US are 32% higher than in Canada and 60% higher than in the UK are in fact overstatements which arise from limitations of the sample and methods used to calculate these price differentials.
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International Nuclear Information System (INIS)
Feretic, D.
1975-01-01
The aim of this summary is to point out some specific areas which have to be covered in a turn-key contract and which are of primarily interest to the buyer of a nuclear plant. It will be assumed that the buyer is utility company in a developing country and a plant supplier a company in an industrial country. (orig./FW) [de
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Entangled quantum key distribution with a biased basis choice
International Nuclear Information System (INIS)
Erven, Chris; Ma Xiongfeng; Laflamme, Raymond; Weihs, Gregor
2009-01-01
We investigate a quantum key distribution (QKD) scheme that utilizes a biased basis choice in order to increase the efficiency of the scheme. The optimal bias between the two measurement bases, a more refined error analysis and finite key size effects are all studied in order to assure the security of the final key generated with the system. We then implement the scheme in a local entangled QKD system that uses polarization entangled photon pairs to securely distribute the key. A 50/50 non-polarizing beamsplitter (BS) with different optical attenuators is used to simulate a variable BS in order to allow us to study the operation of the system for different biases. Over 6 h of continuous operation with a total bias of 0.9837/0.0163 (Z/X), we were able to generate 0.4567 secure key bits per raw key bit as compared to 0.2550 secure key bits per raw key bit for the unbiased case. This represents an increase in the efficiency of the key generation rate by 79%.
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Enhanced Key Management Protocols for Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Baojiang Cui
2015-01-01
Full Text Available With rapid development and extensive use of wireless sensor networks (WSNs, it is urgent to enhance the security for WSNs, in which key management is an effective way to protect WSNs from various attacks. However, different types of messages exchanged in WSNs typically have different security requirements which cannot be satisfied by a single keying mechanism. In this study, a basic key management protocol is described for WSNs based on four kinds of keys, which can be derived from an initial master key, and an enhanced protocol is proposed based on Diffie-Hellman algorithm. The proposed scheme restricts the adverse security impact of a captured node to the rest of WSNs and meets the requirement of energy efficiency by supporting in-network processing. The master key protection, key revocation mechanism, and the authentication mechanism based on one-way hash function are, respectively, discussed. Finally, the performance of the proposed scheme is analyzed from the aspects of computational efficiency, storage requirement and communication cost, and its antiattack capability in protecting WSNs is discussed under various attack models. In this paper, promising research directions are also discussed.
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Key figures for the regional- and distribution grid
International Nuclear Information System (INIS)
Vikingstad, S.
1996-02-01
In Norway, improving the efficiency of the hydroelectric grid operation is a stated goal of the Energy Act. Several studies have identified potential profits of such improvement. This publication focuses on costs and improvement potentials. Publication of key figures may stimulate grid owners, boards and administrations to improve the operating efficiency of their grids. The publication shows key figures for the regional- and distribution grid and is based on accounting data for 1994. The key figures are divided into: (1) Cost structure: The key figures express the relative contributions of each cost component to the total income of the grid, (2) Costs and physical quantities: The key figures show the cost of delivering the transport services, (3) Physical quantities: The key figures describe the working conditions of the energy utility. It appears that the cost structure of the sector varies considerably. The same is true of the cost related to the delivery of grid services. 30 figs., 6 tabs
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Comparison analysis for classification algorithm in data mining and the study of model use
Chen, Junde; Zhang, Defu
2018-04-01
As a key technique in data mining, classification algorithm was received extensive attention. Through an experiment of classification algorithm in UCI data set, we gave a comparison analysis method for the different algorithms and the statistical test was used here. Than that, an adaptive diagnosis model for preventive electricity stealing and leakage was given as a specific case in the paper.
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Foundations of the International System of Units (SI).
Nelson, Robert A.
1981-01-01
Traces the events leading to the creation of the International Bureau of Weights and Measures (BIPM). Discusses how the units have been represented by their standards, and investigates how the original metric system evolved into the International System of Units (SI), focusing on the meter, second, kilogram, and electrical units. (SK)
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Extended KCI attack against two-party key establishment protocols
Tang, Qiang; Chen, Liqun
2011-01-01
We introduce an extended Key Compromise Impersonation (KCI) attack against two-party key establishment protocols, where an adversary has access to both long-term and ephemeral secrets of a victim. Such an attack poses serious threats to both key authentication and key confirmation properties of a
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A Key Management Method for Cryptographically Enforced Access Control
Zych, Anna; Petkovic, Milan; Jonker, Willem; Fernández-Medina, Eduardo; Yagüe, Mariemma I.
Cryptographic enforcement of access control mechanisms relies on encrypting protected data with the keys stored by authorized users. This approach poses the problem of the distribution of secret keys. In this paper, a key management scheme is presented where each user stores a single key and is
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Finding faults: analogical comparison supports spatial concept learning in geoscience.
Jee, Benjamin D; Uttal, David H; Gentner, Dedre; Manduca, Cathy; Shipley, Thomas F; Sageman, Bradley
2013-05-01
A central issue in education is how to support the spatial thinking involved in learning science, technology, engineering, and mathematics (STEM). We investigated whether and how the cognitive process of analogical comparison supports learning of a basic spatial concept in geoscience, fault. Because of the high variability in the appearance of faults, it may be difficult for students to learn the category-relevant spatial structure. There is abundant evidence that comparing analogous examples can help students gain insight into important category-defining features (Gentner in Cogn Sci 34(5):752-775, 2010). Further, comparing high-similarity pairs can be especially effective at revealing key differences (Sagi et al. 2012). Across three experiments, we tested whether comparison of visually similar contrasting examples would help students learn the fault concept. Our main findings were that participants performed better at identifying faults when they (1) compared contrasting (fault/no fault) cases versus viewing each case separately (Experiment 1), (2) compared similar as opposed to dissimilar contrasting cases early in learning (Experiment 2), and (3) viewed a contrasting pair of schematic block diagrams as opposed to a single block diagram of a fault as part of an instructional text (Experiment 3). These results suggest that comparison of visually similar contrasting cases helped distinguish category-relevant from category-irrelevant features for participants. When such comparisons occurred early in learning, participants were more likely to form an accurate conceptual representation. Thus, analogical comparison of images may provide one powerful way to enhance spatial learning in geoscience and other STEM disciplines.
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Accelerating foreign-key joins using asymmetric memory channels
Pirk, H.; Manegold, S.; Kersten, M.
2011-01-01
Indexed Foreign-Key Joins expose a very asymmetric access pattern: the Foreign-Key Index is sequentially scanned whilst the Primary-Key table is target of many quasi-random lookups which is the dominant cost factor. To reduce the costs of the random lookups the fact-table can be (re-) partitioned at
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Directory of Open Access Journals (Sweden)
VanItallie Theodore B
2005-02-01
Full Text Available Abstract Ancel Keys, Ph.D., who died in November, 2004, at the age of 100, was among the first scientists to recognize that human atherosclerosis is not an inevitable consequence of aging, and that a high-fat diet can be a major risk factor for coronary heart disease. During World War II, he and a group of talented co-workers at the University of Minnesota conducted a large-scale study of experimentally-induced human starvation. The data generated by this study – which was immediately recognized to be a classic – continue to be of inestimable value to nutrition scientists. In his later years, Keys spent more time at his home in Naples, Italy, where he had the opportunity to continue his personal study of the beneficial effects on health and longevity of a Mediterranean diet.
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DEFF Research Database (Denmark)
Alcaraz, Nicolas; Pauling, Josch; Batra, Richa
2014-01-01
release of KeyPathwayMiner (version 4.0) that is not limited to analyses of single omics data sets, e.g. gene expression, but is able to directly combine several different omics data types. Version 4.0 can further integrate existing knowledge by adding a search bias towards sub-networks that contain...... (avoid) genes provided in a positive (negative) list. Finally the new release now also provides a set of novel visualization features and has been implemented as an app for the standard bioinformatics network analysis tool: Cytoscape. CONCLUSION: With KeyPathwayMiner 4.0, we publish a Cytoscape app...
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Key China Energy Statistics 2012
Energy Technology Data Exchange (ETDEWEB)
Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2012-05-01
The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). The Group has published seven editions to date of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.
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Key China Energy Statistics 2011
Energy Technology Data Exchange (ETDEWEB)
Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2012-01-15
The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). In 2008 the Group published the Seventh Edition of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.
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Stellar neutron capture rates – key data for the s process
Directory of Open Access Journals (Sweden)
Käppeler F.
2013-12-01
Full Text Available Neutron reactions are responsible for the formation of the elements heavier than iron. The corresponding scenarios relate to the He- and C- burning phases of stellar evolution (s process and to supernova explosions (r and p processes. The s process, which is characterized by low neutron densities, operates in or near the valley of β stability and has produced about half of the elemental abundances between Fe and Bi in the solar system and in the Universe. Because the s abundances are essentially determined by the (n, γ cross sections along the reaction path, accurate neutron data constitute the key input for s process studies. Important constraints for the physical conditions at the stellar sites can be inferred by comparison of the abundance patterns from current s-process models with solar system material or presolar grains. The experimental methods for the determination of stellar (n, γ rates are outlined at the example of recent cross section measurements and remaining quests will be discussed with respect to existing laboratory neutron sources and new developments.
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GuiaTreeKey, a multi-access electronic key to identify tree genera in French Guiana.
Engel, Julien; Brousseau, Louise; Baraloto, Christopher
2016-01-01
The tropical rainforest of Amazonia is one of the most species-rich ecosystems on earth, with an estimated 16000 tree species. Due to this high diversity, botanical identification of trees in the Amazon is difficult, even to genus, often requiring the assistance of parataxonomists or taxonomic specialists. Advances in informatics tools offer a promising opportunity to develop user-friendly electronic keys to improve Amazonian tree identification. Here, we introduce an original multi-access electronic key for the identification of 389 tree genera occurring in French Guiana terra-firme forests, based on a set of 79 morphological characters related to vegetative, floral and fruit characters. Its purpose is to help Amazonian tree identification and to support the dissemination of botanical knowledge to non-specialists, including forest workers, students and researchers from other scientific disciplines. The electronic key is accessible with the free access software Xper ², and the database is publicly available on figshare: https://figshare.com/s/75d890b7d707e0ffc9bf (doi: 10.6084/m9.figshare.2682550).
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Basic study on the rectangular numeric keys for touch screen.
Harada, H; Katsuura, T; Kikuchi, Y
1997-06-01
The present study was conducted to examine the optimum inter-key spacing of numeric rectangular keys for touch screens. Six male students (22-25 years old) and three female students (21-24 years old) participated in the experiment. Each subject performed the data entry task using rectangular keys of touch devices. These keys were arranged in both horizontal and vertical layouts. The sizes of the rectangular keys in both layouts were 12 x 21 mm and 15 x 39 mm, and each of the inter-key spacing of each key was 0, 3, 6, 12 and 21 mm. The response time with inter-key spacing of 3 mm was significantly faster than with the inter-key spacing of 0, 12 and 21 mm (p < 0.05). Keys of vertical position produced faster response time than that of horizontal position. The subjective ratings showed that the inter-key spacing of 6 mm was significantly better than the inter-key spacing of 0, 3, 12 and 21 mm (p < 0.05).
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Secret-key rates and privacy leakage in biometric systems
Ignatenko, T.
2009-01-01
In this thesis both the generation of secret keys from biometric data and the binding of secret keys to biometric data are investigated. These secret keys can be used to regulate access to sensitive data, services, and environments. In a biometric secrecy system a secret key is generated or chosen
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Sergio Beretta; Saverio Bozzolan
2013-01-01
The recent paper issued by COSO ["Developing Key Risk Indicators to Strengthen Enterprise Risk Management" (Coso, 2010)] is the starting point of this article whose aim is to discuss the relevance of the business process dimension in the design and implementation of Key Risk Indicators. The Authors analyze the reasons of the systematic underestimation of the business process dimension in the COSO papers and debate the implications that the explicit consideration of the business process dimens...
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Fundamental quantitative security in quantum key generation
International Nuclear Information System (INIS)
Yuen, Horace P.
2010-01-01
We analyze the fundamental security significance of the quantitative criteria on the final generated key K in quantum key generation including the quantum criterion d, the attacker's mutual information on K, and the statistical distance between her distribution on K and the uniform distribution. For operational significance a criterion has to produce a guarantee on the attacker's probability of correctly estimating some portions of K from her measurement, in particular her maximum probability of identifying the whole K. We distinguish between the raw security of K when the attacker just gets at K before it is used in a cryptographic context and its composition security when the attacker may gain further information during its actual use to help get at K. We compare both of these securities of K to those obtainable from conventional key expansion with a symmetric key cipher. It is pointed out that a common belief in the superior security of a quantum generated K is based on an incorrect interpretation of d which cannot be true, and the security significance of d is uncertain. Generally, the quantum key distribution key K has no composition security guarantee and its raw security guarantee from concrete protocols is worse than that of conventional ciphers. Furthermore, for both raw and composition security there is an exponential catch-up problem that would make it difficult to quantitatively improve the security of K in a realistic protocol. Some possible ways to deal with the situation are suggested.
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Key Frame Extraction in the Summary Space.
Li, Xuelong; Zhao, Bin; Lu, Xiaoqiang; Xuelong Li; Bin Zhao; Xiaoqiang Lu; Lu, Xiaoqiang; Li, Xuelong; Zhao, Bin
2018-06-01
Key frame extraction is an efficient way to create the video summary which helps users obtain a quick comprehension of the video content. Generally, the key frames should be representative of the video content, meanwhile, diverse to reduce the redundancy. Based on the assumption that the video data are near a subspace of a high-dimensional space, a new approach, named as key frame extraction in the summary space, is proposed for key frame extraction in this paper. The proposed approach aims to find the representative frames of the video and filter out similar frames from the representative frame set. First of all, the video data are mapped to a high-dimensional space, named as summary space. Then, a new representation is learned for each frame by analyzing the intrinsic structure of the summary space. Specifically, the learned representation can reflect the representativeness of the frame, and is utilized to select representative frames. Next, the perceptual hash algorithm is employed to measure the similarity of representative frames. As a result, the key frame set is obtained after filtering out similar frames from the representative frame set. Finally, the video summary is constructed by assigning the key frames in temporal order. Additionally, the ground truth, created by filtering out similar frames from human-created summaries, is utilized to evaluate the quality of the video summary. Compared with several traditional approaches, the experimental results on 80 videos from two datasets indicate the superior performance of our approach.
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Exploiting Support Vector Machine Algorithm to Break the Secret Key
Directory of Open Access Journals (Sweden)
S. Hou
2018-04-01
Full Text Available Template attacks (TA and support vector machine (SVM are two effective methods in side channel attacks (SCAs. Almost all studies on SVM in SCAs assume the required power traces are sufficient, which also implies the number of profiling traces belonging to each class is equivalent. Indeed, in the real attack scenario, there may not be enough power traces due to various restrictions. More specifically, the Hamming Weight of the S-Box output results in 9 binomial distributed classes, which significantly reduces the performance of SVM compared with the uniformly distributed classes. In this paper, the impact of the distribution of profiling traces on the performance of SVM is first explored in detail. And also, we conduct Synthetic Minority Oversampling TEchnique (SMOTE to solve the problem caused by the binomial distributed classes. By using SMOTE, the success rate of SVM is improved in the testing phase, and SVM requires fewer power traces to recover the key. Besides, TA is selected as a comparison. In contrast to what is perceived as common knowledge in unrestricted scenarios, our results indicate that SVM with proper parameters can significantly outperform TA.
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Jacak, Monika; Jacak, Janusz; Jóźwiak, Piotr; Jóźwiak, Ireneusz
2016-06-01
The overview of the current status of quantum cryptography is given in regard to quantum key distribution (QKD) protocols, implemented both on nonentangled and entangled flying qubits. Two commercial R&D platforms of QKD systems are described (the Clavis II platform by idQuantique implemented on nonentangled photons and the EPR S405 Quelle platform by AIT based on entangled photons) and tested for feasibility of their usage in commercial TELECOM fiber metropolitan networks. The comparison of systems efficiency, stability and resistivity against noise and hacker attacks is given with some suggestion toward system improvement, along with assessment of two models of QKD.
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A Secure Three-Factor User Authentication and Key Agreement Protocol for TMIS With User Anonymity.
Amin, Ruhul; Biswas, G P
2015-08-01
Telecare medical information system (TMIS) makes an efficient and convenient connection between patient(s)/user(s) and doctor(s) over the insecure internet. Therefore, data security, privacy and user authentication are enormously important for accessing important medical data over insecure communication. Recently, many user authentication protocols for TMIS have been proposed in the literature and it has been observed that most of the protocols cannot achieve complete security requirements. In this paper, we have scrutinized two (Mishra et al., Xu et al.) remote user authentication protocols using smart card and explained that both the protocols are suffering against several security weaknesses. We have then presented three-factor user authentication and key agreement protocol usable for TMIS, which fix the security pitfalls of the above mentioned schemes. The informal cryptanalysis makes certain that the proposed protocol provides well security protection on the relevant security attacks. Furthermore, the simulator AVISPA tool confirms that the protocol is secure against active and passive attacks including replay and man-in-the-middle attacks. The security functionalities and performance comparison analysis confirm that our protocol not only provide strong protection on security attacks, but it also achieves better complexities along with efficient login and password change phase as well as session key verification property.
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Novel secret key generation techniques using memristor devices
Abunahla, Heba; Shehada, Dina; Yeun, Chan Yeob; Mohammad, Baker; Jaoude, Maguy Abi
2016-02-01
This paper proposes novel secret key generation techniques using memristor devices. The approach depends on using the initial profile of a memristor as a master key. In addition, session keys are generated using the master key and other specified parameters. In contrast to existing memristor-based security approaches, the proposed development is cost effective and power efficient since the operation can be achieved with a single device rather than a crossbar structure. An algorithm is suggested and demonstrated using physics based Matlab model. It is shown that the generated keys can have dynamic size which provides perfect security. Moreover, the proposed encryption and decryption technique using the memristor based generated keys outperforms Triple Data Encryption Standard (3DES) and Advanced Encryption Standard (AES) in terms of processing time. This paper is enriched by providing characterization results of a fabricated microscale Al/TiO2/Al memristor prototype in order to prove the concept of the proposed approach and study the impacts of process variations. The work proposed in this paper is a milestone towards System On Chip (SOC) memristor based security.
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Secure key distribution by swapping quantum entanglement
International Nuclear Information System (INIS)
Song, Daegene
2004-01-01
We report two key distribution schemes achieved by swapping quantum entanglement. Using two Bell states, two bits of secret key can be shared between two distant parties that play symmetric and equal roles. We also address eavesdropping attacks against the schemes
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Calculation of key reduction for B92 QKD protocol
Mehic, Miralem; Partila, Pavol; Tovarek, Jaromir; Voznak, Miroslav
2015-05-01
It is well known that Quantum Key Distribution (QKD) can be used with the highest level of security for distribution of the secret key, which is further used for symmetrical encryption. B92 is one of the oldest QKD protocols. It uses only two non-orthogonal states, each one coding for one bit-value. It is much faster and simpler when compared to its predecessors, but with the idealized maximum efficiencies of 25% over the quantum channel. B92 consists of several phases in which initial key is significantly reduced: secret key exchange, extraction of the raw key (sifting), error rate estimation, key reconciliation and privacy amplification. QKD communication is performed over two channels: the quantum channel and the classical public channel. In order to prevent a man-in-the-middle attack and modification of messages on the public channel, authentication of exchanged values must be performed. We used Wegman-Carter authentication because it describes an upper bound for needed symmetric authentication key. We explained the reduction of the initial key in each of QKD phases.
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A secure key agreement protocol based on chaotic maps
International Nuclear Information System (INIS)
Wang Xing-Yuan; Luan Da-Peng
2013-01-01
To guarantee the security of communication in the public channel, many key agreement protocols have been proposed. Recently, Gong et al. proposed a key agreement protocol based on chaotic maps with password sharing. In this paper, Gong et al.'s protocol is analyzed, and we find that this protocol exhibits key management issues and potential security problems. Furthermore, the paper presents a new key agreement protocol based on enhanced Chebyshev polynomials to overcome these problems. Through our analysis, our key agreement protocol not only provides mutual authentication and the ability to resist a variety of common attacks, but also solve the problems of key management and security issues existing in Gong et al.'s protocol
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Extensible router for a quantum key distribution network
International Nuclear Information System (INIS)
Zhang Tao; Mo Xiaofan; Han Zhengfu; Guo Guangcan
2008-01-01
Building a quantum key distribution network is crucial for practical quantum cryptography. We present a scheme to build a star topology quantum key distribution network based on wavelength division multiplexing which, with current technology, can connect at least a hundred users. With the scheme, a 4-user demonstration network was built up and key exchanges were performed
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Key Concepts in Microbial Oceanography
Bruno, B. C.; Achilles, K.; Walker, G.; Weersing, K.; Team, A
2008-12-01
The Center for Microbial Oceanography: Research and Education (C-MORE) is a multi-institution Science and Technology Center, established by the National Science Foundation in 2006. C-MORE's research mission is to facilitate a more comprehensive understanding of the diverse assemblages of microorganisms in the sea, ranging from the genetic basis of marine microbial biogeochemistry including the metabolic regulation and environmental controls of gene expression, to the processes that underpin the fluxes of carbon, related bioelements, and energy in the marine environment. The C-MORE education and outreach program is focused on increasing scientific literacy in microbial oceanography among students, educators, and the general public. A first step toward this goal is defining the key concepts that constitute microbial oceanography. After lengthy discussions with scientists and educators, both within and outside C-MORE, we have arrived at six key concepts: 1) Marine microbes are very small and have been around for a long time; 2) Life on Earth could not exist without microbes; 3) Most marine microbes are beneficial; 4) Microbes are everywhere: they are extremely abundant and diverse; 5) Microbes significantly impact our global climate; and 6) There are new discoveries every day in the field of microbial oceanography. A C-MORE-produced brochure on these six key concepts will be distributed at the meeting. Advanced copies may be requested by email or downloaded from the C-MORE web site(http://cmore.soest.hawaii.edu/downloads/MO_key_concepts_hi-res.pdf). This brochure also includes information on career pathways in microbial oceanography, with the aim of broadening participation in the field. C-MORE is eager to work in partnership to incorporate these key concepts into other science literacy publications, particularly those involving ocean and climate literacy. We thank the following contributors and reviewers: P Chisholm, A Dolberry, and A Thompson (MIT); N Lawrence
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International Nuclear Information System (INIS)
Ma Hongchang; Lu Hanlin; Rong Chaofan
1988-01-01
The methods for absolute measurement of 0.1-18MeV monoenergetic neutron fluence rate are described. Which include proton recoil telescope, semicoducetor telescope, hydrogen filled proportional counter and associated particale method. A long counter used as secondary recent international intercomparison of neutron fluence rate organized by BIPM, and the results were given
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Key-space analysis of double random phase encryption technique
Monaghan, David S.; Gopinathan, Unnikrishnan; Naughton, Thomas J.; Sheridan, John T.
2007-09-01
We perform a numerical analysis on the double random phase encryption/decryption technique. The key-space of an encryption technique is the set of possible keys that can be used to encode data using that technique. In the case of a strong encryption scheme, many keys must be tried in any brute-force attack on that technique. Traditionally, designers of optical image encryption systems demonstrate only how a small number of arbitrary keys cannot decrypt a chosen encrypted image in their system. However, this type of demonstration does not discuss the properties of the key-space nor refute the feasibility of an efficient brute-force attack. To clarify these issues we present a key-space analysis of the technique. For a range of problem instances we plot the distribution of decryption errors in the key-space indicating the lack of feasibility of a simple brute-force attack.
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Certificateless Key-Insulated Generalized Signcryption Scheme without Bilinear Pairings
Directory of Open Access Journals (Sweden)
Caixue Zhou
2017-01-01
Full Text Available Generalized signcryption (GSC can be applied as an encryption scheme, a signature scheme, or a signcryption scheme with only one algorithm and one key pair. A key-insulated mechanism can resolve the private key exposure problem. To ensure the security of cloud storage, we introduce the key-insulated mechanism into GSC and propose a concrete scheme without bilinear pairings in the certificateless cryptosystem setting. We provide a formal definition and a security model of certificateless key-insulated GSC. Then, we prove that our scheme is confidential under the computational Diffie-Hellman (CDH assumption and unforgeable under the elliptic curve discrete logarithm (EC-DL assumption. Our scheme also supports both random-access key update and secure key update. Finally, we evaluate the efficiency of our scheme and demonstrate that it is highly efficient. Thus, our scheme is more suitable for users who communicate with the cloud using mobile devices.
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Lin, Chien-Yu; Chang, Yu-Ming
2014-09-01
In this study, we employed Flash- and Scratch-based multimedia by using a MaKey-MaKey-based task system to increase the motivation level of children with cerebral palsy to perform physical activities. MaKey MaKey is a circuit board that converts physical touch to a digital signal, which is interpreted by a computer as a keyboard message. In this study, we used conductive materials to control this interaction. This study followed single-case design using ABAB models in which A indicated the baseline and B indicated the intervention. The experiment period comprised 1 month and a half. The experimental results demonstrated that in the case of two kindergarten children with cerebral palsy, their scores were considerably increased during the intervention phrases. The developmental applications of the results are also discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Low carbon development. Key issues
Energy Technology Data Exchange (ETDEWEB)
Urban, Frauke; Nordensvaard, Johan (eds.)
2013-03-07
This comprehensive textbook addresses the interface between international development and climate change in a carbon constrained world. It discusses the key conceptual, empirical and policy-related issues of low carbon development and takes an international and interdisciplinary approach to the subject by drawing on insights from across the natural sciences and social sciences whilst embedding the discussion in a global context. The first part explores the concept of low carbon development and explains the need for low carbon development in a carbon constrained world. The book then discusses the key issues of socio-economic, political and technological nature for low carbon development, exploring topics such as the political economy, social justice, financing and carbon markets, and technologies and innovation for low carbon development. This is followed by key issues for low carbon development in policy and practice, which is presented based on cross-cutting issues such as low carbon energy, forestry, agriculture and transportation. Afterwards, practical case studies are discussed from low carbon development in low income countries in Africa, middle income countries in Asia and Latin America and high income countries in Europe and North America.
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Autoshaping of key pecking in pigeons with negative reinforcement.
Rachlin, H
1969-07-01
Pigeons exposed to gradually increasing intensities of pulsing electric shock pecked a key and thereby reduced the intensity of shock to zero for 2 min. Acquisition of key pecking was brought about through an autoshaping process in which periodic brief keylight presentations immediately preceded automatic reduction of the shock. On the occasions of such automatic reduction of shock preceding the first measured key peck, little or no orientation to the key was observed. Observations of pigeons with autoshaping of positive reinforcement also revealed little evidence of orientation toward the key.
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Small private key MQPKS on an embedded microprocessor.
Seo, Hwajeong; Kim, Jihyun; Choi, Jongseok; Park, Taehwan; Liu, Zhe; Kim, Howon
2014-03-19
Multivariate quadratic (MQ) cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to MQ cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011), a small public key MQ scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key MQ scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing MQ on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key MQ scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES) accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012.
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Small Private Key PKS on an Embedded Microprocessor
Seo, Hwajeong; Kim, Jihyun; Choi, Jongseok; Park, Taehwan; Liu, Zhe; Kim, Howon
2014-01-01
Multivariate quadratic ( ) cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011), a small public key scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES) accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012. PMID:24651722
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Key-lock colloids in a nematic liquid crystal.
Silvestre, Nuno M; Tasinkevych, M
2017-01-01
The Landau-de Gennes free energy is used to study theoretically the effective interaction of spherical "key" and anisotropic "lock" colloidal particles. We assume identical anchoring properties of the surfaces of the key and of the lock particles, and we consider planar degenerate and perpendicular anchoring conditions separately. The lock particle is modeled as a spherical particle with a spherical dimple. When such a particle is introduced into a nematic liquid crystal, it orients its dimple at an oblique angle θ_{eq} with respect to the far field director n_{∞}. This angle depends on the depth of the dimple. Minimization results show that the free energy of a pair of key and lock particles exhibits a global minimum for the configuration when the key particle is facing the dimple of the lock colloidal particle. The preferred orientation ϕ_{eq} of the key-lock composite doublet relative to n_{∞} is robust against thermal fluctuations. The preferred orientation θ_{eq}^{(2)} of the dimple particle in the doublet is different from the isolated situation. This is related to the "direct" interaction of defects accompanying the key particle with the edge of the dimple. We propose that this nematic-amplified key-lock interaction can play an important role in self-organization and clustering of mixtures of colloidal particles with dimple colloids present.
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Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min
2016-01-01
Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information.
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Yang, Yu-Guang; Xu, Peng; Yang, Rui; Zhou, Yi-Hua; Shi, Wei-Min
2016-01-01
Quantum information and quantum computation have achieved a huge success during the last years. In this paper, we investigate the capability of quantum Hash function, which can be constructed by subtly modifying quantum walks, a famous quantum computation model. It is found that quantum Hash function can act as a hash function for the privacy amplification process of quantum key distribution systems with higher security. As a byproduct, quantum Hash function can also be used for pseudo-random number generation due to its inherent chaotic dynamics. Further we discuss the application of quantum Hash function to image encryption and propose a novel image encryption algorithm. Numerical simulations and performance comparisons show that quantum Hash function is eligible for privacy amplification in quantum key distribution, pseudo-random number generation and image encryption in terms of various hash tests and randomness tests. It extends the scope of application of quantum computation and quantum information. PMID:26823196
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Mathematical Background of Public Key Cryptography
DEFF Research Database (Denmark)
Frey, Gerhard; Lange, Tanja
2005-01-01
The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material.......The two main systems used for public key cryptography are RSA and protocols based on the discrete logarithm problem in some cyclic group. We focus on the latter problem and state cryptographic protocols and mathematical background material....
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Renyi information gain on quantum key
International Nuclear Information System (INIS)
Brandt, Howard E
2007-01-01
The concept of maximum Renyi information gain from quantum key is important in eavesdropping and security analyses of quantum key distribution. It is particularly useful in the design optimization of eavesdropping probes. The present work reviews the quantitative measure of Renyi information gain, its optimization, and application to the design of eavesdropping probes in which single-photon probe states become optimally entangled with the signal states on their way between the legitimate transmitter and receiver
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Authenticated group Diffie-Hellman key exchange: theory and practice
Energy Technology Data Exchange (ETDEWEB)
Chevassut, Olivier [Catholic Univ. of Louvain, Louvain-la-Neuve (Belgium)
2002-10-01
Authenticated two-party Diffie-Hellman key exchange allows two principals A and B, communicating over a public network, and each holding a pair of matching public/private keys to agree on a session key. Protocols designed to deal with this problem ensure A (B resp.)that no other principals aside from B (A resp.) can learn any information about this value. These protocols additionally often ensure A and B that their respective partner has actually computed the shared secret value. A natural extension to the above cryptographic protocol problem is to consider a pool of principals agreeing on a session key. Over the years several papers have extended the two-party Diffie-Hellman key exchange to the multi-party setting but no formal treatments were carried out till recently. In light of recent developments in the formalization of the authenticated two-party Diffie-Hellman key exchange we have in this thesis laid out the authenticated group Diffie-Hellman key exchange on firmer foundations.
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Novel secret key generation techniques using memristor devices
Directory of Open Access Journals (Sweden)
Heba Abunahla
2016-02-01
Full Text Available This paper proposes novel secret key generation techniques using memristor devices. The approach depends on using the initial profile of a memristor as a master key. In addition, session keys are generated using the master key and other specified parameters. In contrast to existing memristor-based security approaches, the proposed development is cost effective and power efficient since the operation can be achieved with a single device rather than a crossbar structure. An algorithm is suggested and demonstrated using physics based Matlab model. It is shown that the generated keys can have dynamic size which provides perfect security. Moreover, the proposed encryption and decryption technique using the memristor based generated keys outperforms Triple Data Encryption Standard (3DES and Advanced Encryption Standard (AES in terms of processing time. This paper is enriched by providing characterization results of a fabricated microscale Al/TiO2/Al memristor prototype in order to prove the concept of the proposed approach and study the impacts of process variations. The work proposed in this paper is a milestone towards System On Chip (SOC memristor based security.
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Practical quantum key distribution with polarization-entangled photons
International Nuclear Information System (INIS)
Poppe, A.; Fedrizzi, A.; Boehm, H.; Ursin, R.; Loruenser, T.; Peev, M.; Maurhardt, O.; Suda, M.; Kurtsiefer, C.; Weinfurter, H.; Jennewein, T.; Zeilinger, A.
2005-01-01
Full text: We present an entangled-state quantum cryptography system that operated for the first time in a real-world application scenario. The full key generation protocol was performed in real-time between two distributed embedded hardware devices, which were connected by 1.45 km of optical fiber, installed for this experiment in the Vienna sewage system. A source for polarization-entangled photons delivered about 8200 entangled photon pairs per second. After transmission to the distant receivers, a mean value of 468 pairs per second remained for the generation of a raw key, which showed an average qubit error rate of 6.4 %. The raw key was sifted and subsequently processed by a classical protocol which included error correction and privacy amplification. The final secure key bit rate was about 76 bits per second. The generated quantum key was then handed over and used by a secure communication application. (author)
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Optimal grazing management strategies: evaluating key concepts ...
African Journals Online (AJOL)
Finally, overstocking will override key management initiatives, such as effective recovery periods, leading to rangeland degradation. Thus, in variable climates, stocking rate should be set conservatively to allow easier adaptation of animal numbers to rainfall variability from year to year. We suggest several key concepts that ...
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Key Update Assistant for Resource-Constrained Networks
DEFF Research Database (Denmark)
Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming
2012-01-01
developed a push-button solution - powered by stochastic model checking - that network designers can easily benefit from, and it paves the way for consumers to set up key update related security parameters. Key Update Assistant, as we named it, runs necessary model checking operations and determines...
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Hubert, Antoine; Dadonau, Maksim; Dembele, Siaka; Denissenko, Petr; Wen, Jennifer
2017-11-01
Growing demand for the LNG fosters growth of the number of production sites with varying composition and density. Combining different sources of LNG may result in a stably stratified system, in which heat and mass transfer between the layers is limited. Heating of the LNG due to wall thermal conductivity leads to formation of convection cells confined within the layers. While the upper layer can release the extra energy via preferential methane boil-off, the bottom layer cannot and hence becomes superheated. Gradual density equilibration reduces stratification and may eventually lead to a sudden mixing event called ``rollover'', accompanied by violent evaporation of the superheated LNG. Three phenomena are potentially responsible for density equilibration. The first is the growing difference in thermal expansion of the layers due to the reduced ability of the bottom layer to reject heat. The second is the penetration of the heated near-wall boundary layer into the upper layer. The third is the ``entrainment mixing'' occurring at the contact surface between the two layers. The present study uses CFD to compare these mechanisms. Boussinesq approximation and an extended version of the k- ɛ model is used. The code is validated by comparison with a large-scale LNG rollover experiment.
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Using USB Keys to Promote Mobile Learning
Directory of Open Access Journals (Sweden)
Marilyne Rosselle
2009-07-01
Full Text Available M-learning (i.e. mobile learning is a field of e-learning that provides learners learning environments using mobile technology. In this context, learning can take place anywhere and anytime, in open and distance learning. Depending on the type of technology it may be done through software called nomadic (i.e. prepared to mobility. Among these technologies, there are those composed of digital interfaces and with autonomy of treatment: Smartphone, PDA, calculator and even mp3 key. In this article we propose to take into account storage devices as mobile technologies. Our focus was on the USB key. We present a procedure to test whether a learning environment embarked on a USB key can be described as nomadic or not. This procedure has been tested on a sample of three ILE (Interactive Learning Environment. This approach has allowed us to define criteria of nomadism, criteria which were then included in the design of a synchronous Weblog on USB key.
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International Nuclear Information System (INIS)
Pierce, R.H.; Henry, M.S.; Blum, T.C.
2005-01-01
This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS). The study monitored the distribution and persistente of two mosquito adulticides, permethrin and dibrom (naled), during three separate routine applications by the Florida Keys Mosquito Control District. The approach was to determine if toxic concentrations of the pesticides entered the FKNMS by aerial drift or tidal transport. The amount of pesticide entering the FKNMS by way of aerial drift was monitored by collection on glass fiber filter pads, set on floats in a grid pattern on either side of the FKNMS. Permethrin was recovered from filter pads on the leeward side for each of the three applications, ranging from 0.5 to 50.1 μg/m2 throughout the study. Tidal current transport was monitored by collection of surface and subsurface water samples at each grid site. Tidal transport of naled and dichlorvos (naled degradation product) was apparent in the adjacent waters of the FKNMS. These compounds were detected in subsurface, offshore water at 0.1 to 0.6 gg/l, 14 hr after application. Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 μg/1 were found in surface water from the canal system adjacent to the application route. Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50, 96 hr for Mysidopsis bahia = 0.02 μg/1) indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas [es
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Password-based authenticated key exchange scheme using smart card
Liu, Hui; Zhong, Shaojun
2013-03-01
A protocol that allows any two entities to negotiate a shared session key is commonly called a key exchange protocol. If the protocol provides a function to authenticate each other, we call the protocol authenticated key exchange protocol (AKE). Password authentication key exchange (PAKE) is the AKE protocol in which the two entities share a humanmemorable password. Most of current PAKE relies on the existence of a public key infrastructure, which sometime is impossible for a certain environments such as low computational device due to the computation overhead. In this paper, we propose password-based authenticated key exchange using smart card. Compared to previous PAKE, our protocol is more efficient because our protocol is based on ECC. Thereby, the proposed protocol can be well applied to low computation device.
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Secured Session-key Distribution using control Vector Encryption / Decryption Process
International Nuclear Information System (INIS)
Ismail Jabiullah, M.; Abdullah Al-Shamim; Khaleqdad Khan, ANM; Lutfar Rahman, M.
2006-01-01
Frequent key changes are very much desirable for the secret communications and are thus in high demand. A session-key distribution technique has been designed and implemented using the programming language C on which the communication between the end-users is encrypted is used for the duration of a logical connection. Each session-key is obtained from the key distribution center (KDC) over the same networking facilities used for end-user communication. The control vector is cryptographically coupled with the session-key at the time of key generation in the KDC. For this, the generated hash function, master key and the session-key are used for producing the encrypted session-key, which has to be transferred. All the operations have been performed using the C programming language. This process can be widely applicable to all sorts of electronic transactions online or offline; commercially and academically.(authors)
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Physician Appraisals: Key Challenges
Directory of Open Access Journals (Sweden)
Klich Jacek
2017-06-01
Full Text Available The main purpose of the article is to identify key criteria being used for physician appraisals and to find how communication skills of physicians are valued in those appraisals. ScienceDirect and EBSCOhost databases were used for this search. The results show that a physician appraisal is underestimated both theoretically and empirically. The particular gap exists with respect to the communication skills of physicians, which are rarely present in medical training syllabi and physician assessments. The article contributes to the theoretical discourse on physician appraisals and points out at the inconsistency between the high status of physicians as a key hospital resource on the one hand and, on the other hand, at inadequate and poorly researched assessment of their performance with a special emphasis on communication skills. The article may inspire health managers to develop and implement up-to-date assessment forms for physicians and good managerial practices in this respect in hospitals and other health care units.
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Small Private Key MQPKS on an Embedded Microprocessor
Directory of Open Access Journals (Sweden)
Hwajeong Seo
2014-03-01
Full Text Available Multivariate quadratic (MQ cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to MQ cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011, a small public key MQ scheme, was proposed, and its feasible implementation on an embedded microprocessor was reported at CHES2012. However, the implementation of a small private key MQ scheme was not reported. For efficient implementation, random number generators can contribute to reduce the key size, but the cost of using a random number generator is much more complex than computing MQ on modern microprocessors. Therefore, no feasible results have been reported on embedded microprocessors. In this paper, we propose a feasible implementation on embedded microprocessors for a small private key MQ scheme using a pseudo-random number generator and hash function based on a block-cipher exploiting a hardware Advanced Encryption Standard (AES accelerator. To speed up the performance, we apply various implementation methods, including parallel computation, on-the-fly computation, optimized logarithm representation, vinegar monomials and assembly programming. The proposed method reduces the private key size by about 99.9% and boosts signature generation and verification by 5.78% and 12.19% than previous results in CHES2012.
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DEFF Research Database (Denmark)
de Bikuna Salinas, Koldo Saez; Hamelin, Lorie; Hauschild, Michael Zwicky
2018-01-01
Five currently used methods to account for the global warming (GW) impact of the induced land-use change (LUC) greenhouse gas (GHG) emissions have been applied to four biofuel case studies. Two of the investigated methods attempt to avoid the need of considering a definite occupation -thus...... amortization period by considering ongoing LUC trends as a dynamic baseline. This leads to the accounting of a small fraction (0.8%) of the related emissions from the assessed LUC, thus their validity is disputed. The comparison of methods and contrasting case studies illustrated the need of clearly...... distinguishing between the different time horizons involved in life cycle assessments (LCA) of land-demanding products like biofuels. Absent in ISO standards, and giving rise to several confusions, definitions for the following time horizons have been proposed: technological scope, inventory model, impact...
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Eight Key Facets of Small Business Management.
Scott, James Calvert
1980-01-01
Identifies eight key facets of small business management and suggests activities that may be used to assist in their development. The key facets are (1) product or service, (2) competition, (3) marketing strategies, (4) personnel needs, (5) equipment and facility needs, (6) finances, (7) planning, and (8) entrepreneurship. (JOW)
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Public key infrastructure for DOE security research
Energy Technology Data Exchange (ETDEWEB)
Aiken, R.; Foster, I.; Johnston, W.E. [and others
1997-06-01
This document summarizes the Department of Energy`s Second Joint Energy Research/Defence Programs Security Research Workshop. The workshop, built on the results of the first Joint Workshop which reviewed security requirements represented in a range of mission-critical ER and DP applications, discussed commonalties and differences in ER/DP requirements and approaches, and identified an integrated common set of security research priorities. One significant conclusion of the first workshop was that progress in a broad spectrum of DOE-relevant security problems and applications could best be addressed through public-key cryptography based systems, and therefore depended upon the existence of a robust, broadly deployed public-key infrastructure. Hence, public-key infrastructure ({open_quotes}PKI{close_quotes}) was adopted as a primary focus for the second workshop. The Second Joint Workshop covered a range of DOE security research and deployment efforts, as well as summaries of the state of the art in various areas relating to public-key technologies. Key findings were that a broad range of DOE applications can benefit from security architectures and technologies built on a robust, flexible, widely deployed public-key infrastructure; that there exists a collection of specific requirements for missing or undeveloped PKI functionality, together with a preliminary assessment of how these requirements can be met; that, while commercial developments can be expected to provide many relevant security technologies, there are important capabilities that commercial developments will not address, due to the unique scale, performance, diversity, distributed nature, and sensitivity of DOE applications; that DOE should encourage and support research activities intended to increase understanding of security technology requirements, and to develop critical components not forthcoming from other sources in a timely manner.
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Dyjack, D T; Levine, S P; Holtshouser, J L; Schork, M A
1998-06-01
Numerous manufacturing and service organizations have integrated or are considering integration of their respective occupational health and safety management and audit systems into the International Organization for Standardization-based (ISO) audit-driven Quality Management Systems (ISO 9000) or Environmental Management Systems (ISO 14000) models. Companies considering one of these options will likely need to identify and evaluate several key factors before embarking on such efforts. The purpose of this article is to identify and address the key factors through a case study approach. Qualitative and quantitative comparisons of the key features of the American Industrial Hygiene Association ISO-9001 harmonized Occupational Health and Safety Management System with The Goodyear Tire & Rubber Co. management and audit system were conducted. The comparisons showed that the two management systems and their respective audit protocols, although structured differently, were not substantially statistically dissimilar in content. The authors recommend that future studies continue to evaluate the advantages and disadvantages of various audit protocols. Ideally, these studies would identify those audit outcome measures that can be reliably correlated with health and safety performance.
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Measurement of the specific heat capacity of graphite
Energy Technology Data Exchange (ETDEWEB)
Picard, S.; Burns, D.T.; Roger, P
2006-01-15
With the objective of implementing graphite calorimetry at the BIPM to measure absorbed dose, an experimental assembly has recently been constructed to measure the specific heat capacity of graphite. A status description of the apparatus and results from the first measurements are given. The outcome is discussed and the experimental uncertainty is reviewed. (authors)
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Measurement of the specific heat capacity of graphite
International Nuclear Information System (INIS)
Picard, S.; Burns, D.T.; Roger, P.
2006-01-01
With the objective of implementing graphite calorimetry at the BIPM to measure absorbed dose, an experimental assembly has recently been constructed to measure the specific heat capacity of graphite. A status description of the apparatus and results from the first measurements are given. The outcome is discussed and the experimental uncertainty is reviewed. (authors)
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Claude Ducastel
The GS-LS-SEM section is pleased to inform you that as from Monday 30 November 2009, the opening hours of the Locks and Keys service will be the following: 08h30 - 12h30 / 13h30 - 16:30, Mondays to Fridays. GS-SEM-LS 73333
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Quantum key distribution using three basis states
Indian Academy of Sciences (India)
Home; Journals; Pramana – Journal of Physics; Volume 54; Issue 5. Quantum key distribution using three ... This note presents a method of public key distribution using quantum communication of photons that simultaneously provides a high probability that the bits have not been tampered. It is a variant of the quantum ...
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Mitigation of Control Channel Jamming via Combinatorial Key Distribution
Falahati, Abolfazl; Azarafrooz, Mahdi
The problem of countering control channel jamming against internal adversaries in wireless ad hoc networks is addressed. Using combinatorial key distribution, a new method to secure the control channel access is introduced. This method, utilizes the established keys in the key establishment phase to hide the location of control channels without the need for a secure BS. This is in obtained by combination of a collision free one-way function and a combinatorial key establishment method. The proposed scheme can be considered as a special case of the ALOHA random access schemes which uses the common established keys as its seeds to generate the pattern of transmission.
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Experimental aspects of deterministic secure quantum key distribution
Energy Technology Data Exchange (ETDEWEB)
Walenta, Nino; Korn, Dietmar; Puhlmann, Dirk; Felbinger, Timo; Hoffmann, Holger; Ostermeyer, Martin [Universitaet Potsdam (Germany). Institut fuer Physik; Bostroem, Kim [Universitaet Muenster (Germany)
2008-07-01
Most common protocols for quantum key distribution (QKD) use non-deterministic algorithms to establish a shared key. But deterministic implementations can allow for higher net key transfer rates and eavesdropping detection rates. The Ping-Pong coding scheme by Bostroem and Felbinger[1] employs deterministic information encoding in entangled states with its characteristic quantum channel from Bob to Alice and back to Bob. Based on a table-top implementation of this protocol with polarization-entangled photons fundamental advantages as well as practical issues like transmission losses, photon storage and requirements for progress towards longer transmission distances are discussed and compared to non-deterministic protocols. Modifications of common protocols towards a deterministic quantum key distribution are addressed.
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Detector decoy quantum key distribution
International Nuclear Information System (INIS)
Moroder, Tobias; Luetkenhaus, Norbert; Curty, Marcos
2009-01-01
Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum key distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum key distribution protocols.
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International Nuclear Information System (INIS)
Lu, Erli; Tuna, Floriana; Kaltsoyannis, Nikolas; Liddle, Stephen T.; Lewis, William
2016-01-01
We report uranium(IV)-carbene-imido-amide metalla-allene complexes [U(BIPM"T"M"S)(NCPh_3)(NHCPh_3)(M)] (BIPM"T"M"S=C(PPh_2NSiMe_3)_2; M=Li or K) that can be described as R_2C=U=NR' push-pull metalla-allene units, as organometallic counterparts of the well-known push-pull organic allenes. The solid-state structures reveal that the R_2C=U=NR' units adopt highly unusual cis-arrangements, which are also reproduced by gas-phase theoretical studies conducted without the alkali metals to remove their potential structure-directing roles. Computational studies confirm the double-bond nature of the U=NR' and U=CR_2 interactions, the latter increasingly attenuated by potassium then lithium when compared to the hypothetical alkali-metal-free anion. Combined experimental and theoretical data show that the push-pull effect induced by the alkali metal cations and amide auxiliary gives a fundamental and tunable structural influence over the C=U"I"V=N units. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
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Secret Key Agreement: Fundamental Limits and Practical Challenges
Rezki, Zouheir
2017-02-15
Despite the tremendous progress made toward establishing PLS as a new paradigm to guarantee security of communication systems at the physical layerthere is a common belief among researchers and industrials that there are many practical challenges that prevent PLS from flourishing at the industrial scale. Most secure message transmission constructions available to date are tied to strong assumptions on CSI, consider simple channel models and undermine eavesdropping capabilities; thus compromising their practical interest to a big extent. Perhaps arguably, the most likely reasonable way to leverage PLS potential in securing modern wireless communication systems is via secret-key agreement. In the latter setting, the legitimate parties try to agree on a key exploiting availability of a public channel with high capacity which is also accessible to the eavesdropper. Once a key is shared by the legitimate parties, they may use it in a one-time pad encryption, for instance. In this article, we investigate two performance limits of secret-key agreement communications; namely, the secret-key diversity-multiplexing trade-off and the effect of transmit correlation on the secretkey capacity. We show via examples how secretkey agreement offers more flexibility than secure message transmissions. Finally, we explore a few challenges of secret-key agreement concept and propose a few guidelines to overturn them.
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The Public-Key-Infrastructure of the Radiological Society of Germany
International Nuclear Information System (INIS)
Schuetze, B.; Kaemmerer, M.; Klos, G.; Mildenberger, P.
2006-01-01
Pretty Good Privacy (PGP) encoding is based on the Public-Key-Procedure and permits the safe transmission of medical data. Furthermore it allows the use of an electronic signature provided that keys used belong to the key owner and that the key owner's identity is guaranteed by a trusted third party. Under the auspices of the Radiological Society of Germany (Deutsche Roentgengesellschaft, DRG) its IT-Working Group (Arbeitsgemeinschaft fuer Informationstechnik, GIT) built up an appropriate Certification Authority including the required Public-Key-Infrastructure. These GIT certified PGP keys allow the legal use of telemedicine in Germany. Digital signatures based to those certified keys correspond to the advanced signature according to the German Signature Law
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The Public-Key-Infrastructure of the Radiological Society of Germany
Energy Technology Data Exchange (ETDEWEB)
Schuetze, B. [Johannes Gutenberg-University of Mainz, Department of Radiology, Langenbeckstr. 1, 55131 Mainz (Germany)]. E-mail: schuetze@medizin-informatik.org; Kaemmerer, M. [Johannes Gutenberg-University of Mainz, Department of Radiology, Langenbeckstr. 1, 55131 Mainz (Germany); Klos, G. [Johannes Gutenberg-University of Mainz, Department of Radiology, Langenbeckstr. 1, 55131 Mainz (Germany); Mildenberger, P. [Johannes Gutenberg-University of Mainz, Department of Radiology, Langenbeckstr. 1, 55131 Mainz (Germany)
2006-03-15
Pretty Good Privacy (PGP) encoding is based on the Public-Key-Procedure and permits the safe transmission of medical data. Furthermore it allows the use of an electronic signature provided that keys used belong to the key owner and that the key owner's identity is guaranteed by a trusted third party. Under the auspices of the Radiological Society of Germany (Deutsche Roentgengesellschaft, DRG) its IT-Working Group (Arbeitsgemeinschaft fuer Informationstechnik, GIT) built up an appropriate Certification Authority including the required Public-Key-Infrastructure. These GIT certified PGP keys allow the legal use of telemedicine in Germany. Digital signatures based to those certified keys correspond to the advanced signature according to the German Signature Law.
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Strategy Keys as Tools for Problem Solving
Herold-Blasius, Raja
2017-01-01
Problem solving is one of the main competences we seek to teach students at school for use in their future lives. However, when dealing with mathematical problems, teachers encounter a wide variety of difficulties. To foster students' problem-solving skills, the authors developed "strategy keys." Strategy keys can serve as material to…
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Small Private Key PKS on an Embedded Microprocessor
Seo, Hwajeong; Kim, Jihyun; Choi, Jongseok; Park, Taehwan; Liu, Zhe; Kim, Howon
2014-01-01
Multivariate quadratic (MQ) cryptography requires the use of long public and private keys to ensure a sufficient security level, but this is not favorable to embedded systems, which have limited system resources. Recently, various approaches to MQ cryptography using reduced public keys have been studied. As a result of this, at CHES2011 (Cryptographic Hardware and Embedded Systems, 2011), a small public key MQ scheme, was proposed, and its feasible implementation on an embedded microprocessor...