J Andrés Christen
Biographic Data
| ID | 4129376 |
|---|---|
| NAME | J Andrés Christen |
| GIVEN NAMES | J Andrés |
| FAMILY NAME | Christen |
| SIGNATURE | CHRISTEN J A |
| AFFILIATIONS | Mathematics Research Center |
| ORCID | 0000-0002-5795-4345 |
| VERIFIED | Yes |
| TOTAL WORKS | 13 |
| TOTAL CITATIONS | 125 |
| AUTHOR COUNT | 13 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1994 |
| LATEST PUBLICATION YEAR | 2024 |
| H-INDEX | 7 |
Modelling chronologically ordered radiocarbon dates in R
Studies with multiple radiocarbon dates often contain useful information on the relative locations of the dated levels. Such information can be used to obtain robust, integrated site chronologies, with at times more precise ages than those of the individual dates, where outliers can be identified and downweighted, and where the ages of any undated levels can also be estimated. Examples include trees with radiocarbon dates separated by exactly kno…
Ams 14 C Dating of the Mayan Codex of Mexico Revisited
The Mayan Codex of Mexico (MCM), the only Mayan codex found in the 20th century, was unveiled in 1971 during the Ancient Maya Calligraphy exhibition at Club Grolier. The codex comprises 10 pages of bark paper in accordion format, coated with a layer of plaster on both sides. It illustrates the synodic cycles of Venus, with its four phases. Since its discovery, the MCM has been subject to controversy and discussions about its authenticity. In 2016…
Flexible paleoclimate age-depth models using an autoregressive gamma process
Radiocarbon dating is routinely used in paleoecology to build chronologies of lake and peat sediments, aiming at inferring a model that would relate the sediment depth with its age. We present a new approach for chronology building (called "Bacon") that has received enthusiastic attention by paleoecologists. Our methodology is based on controlling core accumulation rates using a gamma autoregressive semiparametric model with an arbitrary number o…
Random walk simulations of fossil proxy data
A wealth of palaeoecological studies (e.g. pollen, diatoms, chironomids and macrofossils from deposits such as lakes or bogs) have revealed major as well as more subtle ecosystem changes over decadal to multimillennial timescales. Such ecosystem changes are usually assumed to have been forced by specific environmental changes. Here, we test if the observed changes in palaeoecological records may be reproduced by random simulations, and we find th…
A New Robust Statistical Model for Radiocarbon Data
The general method currently used to analyze radiocarbon data ( y ) is conditional on the standard deviation (σ), reported by 14 C laboratories, which reflects the uncertainty in the dating process. This uncertainty is measured through a series of empirical as well as theoretical considerations about the dating process, chemical preprocessing, etc. Nevertheless, σ is assumed as known in the statistical model for 14 C data used since the dawn of t…
Testing the timing of radiocarbon-dated events between proxy archives
For interpreting past changes on a regional or global scale, the timings of proxy-inferred events are usually aligned with data from other locations. However, too often chronological uncertainties are ignored in proxy diagrams and multisite comparisons, making it possible for researchers to fall into the trap of sucking separate events into one illusionary event (or vice versa). Here we largely solve this ‘suck in and smear syndrome’ for radiocar…
A Bayesian Framework for Age Modeling of Radiocarbon-Dated Peat Deposits
Recently, Bayesian statistical software has been developed for age-depth modeling (“wiggle-match dating”) of sequences of densely spaced radiocarbon dates from peat cores. The method is described in non-statistical terms, and is compared with an alternative method of chronological ordering of 14 C dates. Case studies include the dating of the start of agriculture in the northeastern part of the Netherlands, and of a possible Hekla-3 tephra layer …
The Comparison of 14 C Wiggle-Matching Results for the ‘Floating’ Tree-Ring Chronology of the Ulandryk-4 Burial Ground (Altai Mountains, Siberia)
Two independent 14 C data sets of 10 tree-ring samples from the longest master chronology of the Pazyryk cultural complex were obtained and wiggle-matched to the absolute timescale. The results show very good agreement, within 10–15 calendar yr. The Ulandryk-4 burial ground (mound 1) was dated to about 320–310 cal BC, and this is consistent with wiggle-matching of the Pazyryk burial ground date series
Bwigg
The integrated calibration of radiocarbon determinations and contextual information based on Bayesian statistical inference is known as 'Bayesian calibration'. Bayesian calibration was developed in the 1990s and there is software available, or under development, to perform various different types of applications: BCal, OxCal, Cal25 or CalPal; see also BCal, in Internet Archaeology. However, no software is available for performing fully Bayesian w…
BCal
In this paper we describe newly launched software for on-line Bayesian calibration of archaeological radiocarbon determinations. The software is known as BCal and we invite members of the world-wide archaeological research community to use it should they so wish. All that is required to gain access to the software is a computer connected to the Internet with a modern World-wide Web browser (of the sort you are probably using to read this). BCal d…
A Novel Approach to Selecting Samples for Radiocarbon Dating
A bayesian approach to wiggle-matching
Estimating the Duration of Archaeological Activity Using 14 C Determinations
One of the questions that archaeologists have always hoped to be able to answer using radiocarbon dating is: ‘How long did this activity last?'. It has for some time been accepted that this question cannot adequately be addressed by simply calibrating single radiocarbon determinations. Rather, it is necessary to find means for coherently relating such determinations to one another and to the archaeology from which they came. In addition, most arc…
A bayesian approach to wiggle-matching
BCal
In this paper we describe newly launched software for on-line Bayesian calibration of archaeological radiocarbon determinations. The software is known as BCal and we invite members of the world-wide archaeological research community to use it should they so wish. All that is required to gain access to the software is a computer connected to the Internet with a modern World-wide Web browser (of the sort you are probably using to read this). BCal d…
Estimating the Duration of Archaeological Activity Using 14 C Determinations
One of the questions that archaeologists have always hoped to be able to answer using radiocarbon dating is: ‘How long did this activity last?'. It has for some time been accepted that this question cannot adequately be addressed by simply calibrating single radiocarbon determinations. Rather, it is necessary to find means for coherently relating such determinations to one another and to the archaeology from which they came. In addition, most arc…
Testing the timing of radiocarbon-dated events between proxy archives
For interpreting past changes on a regional or global scale, the timings of proxy-inferred events are usually aligned with data from other locations. However, too often chronological uncertainties are ignored in proxy diagrams and multisite comparisons, making it possible for researchers to fall into the trap of sucking separate events into one illusionary event (or vice versa). Here we largely solve this ‘suck in and smear syndrome’ for radiocar…
A New Robust Statistical Model for Radiocarbon Data
The general method currently used to analyze radiocarbon data ( y ) is conditional on the standard deviation (σ), reported by 14 C laboratories, which reflects the uncertainty in the dating process. This uncertainty is measured through a series of empirical as well as theoretical considerations about the dating process, chemical preprocessing, etc. Nevertheless, σ is assumed as known in the statistical model for 14 C data used since the dawn of t…
A Novel Approach to Selecting Samples for Radiocarbon Dating
A Bayesian Framework for Age Modeling of Radiocarbon-Dated Peat Deposits
Recently, Bayesian statistical software has been developed for age-depth modeling (“wiggle-match dating”) of sequences of densely spaced radiocarbon dates from peat cores. The method is described in non-statistical terms, and is compared with an alternative method of chronological ordering of 14 C dates. Case studies include the dating of the start of agriculture in the northeastern part of the Netherlands, and of a possible Hekla-3 tephra layer …
The Comparison of 14 C Wiggle-Matching Results for the ‘Floating’ Tree-Ring Chronology of the Ulandryk-4 Burial Ground (Altai Mountains, Siberia)
Two independent 14 C data sets of 10 tree-ring samples from the longest master chronology of the Pazyryk cultural complex were obtained and wiggle-matched to the absolute timescale. The results show very good agreement, within 10–15 calendar yr. The Ulandryk-4 burial ground (mound 1) was dated to about 320–310 cal BC, and this is consistent with wiggle-matching of the Pazyryk burial ground date series
Bwigg
The integrated calibration of radiocarbon determinations and contextual information based on Bayesian statistical inference is known as 'Bayesian calibration'. Bayesian calibration was developed in the 1990s and there is software available, or under development, to perform various different types of applications: BCal, OxCal, Cal25 or CalPal; see also BCal, in Internet Archaeology. However, no software is available for performing fully Bayesian w…
Ams 14 C Dating of the Mayan Codex of Mexico Revisited
The Mayan Codex of Mexico (MCM), the only Mayan codex found in the 20th century, was unveiled in 1971 during the Ancient Maya Calligraphy exhibition at Club Grolier. The codex comprises 10 pages of bark paper in accordion format, coated with a layer of plaster on both sides. It illustrates the synodic cycles of Venus, with its four phases. Since its discovery, the MCM has been subject to controversy and discussions about its authenticity. In 2016…
Random walk simulations of fossil proxy data
A wealth of palaeoecological studies (e.g. pollen, diatoms, chironomids and macrofossils from deposits such as lakes or bogs) have revealed major as well as more subtle ecosystem changes over decadal to multimillennial timescales. Such ecosystem changes are usually assumed to have been forced by specific environmental changes. Here, we test if the observed changes in palaeoecological records may be reproduced by random simulations, and we find th…
Estimating the Duration of Archaeological Activity Using 14 C Determinations
One of the questions that archaeologists have always hoped to be able to answer using radiocarbon dating is: ‘How long did this activity last?'. It has for some time been accepted that this question cannot adequately be addressed by simply calibrating single radiocarbon determinations. Rather, it is necessary to find means for coherently relating such determinations to one another and to the archaeology from which they came. In addition, most arc…
A bayesian approach to wiggle-matching
A Novel Approach to Selecting Samples for Radiocarbon Dating
BCal
In this paper we describe newly launched software for on-line Bayesian calibration of archaeological radiocarbon determinations. The software is known as BCal and we invite members of the world-wide archaeological research community to use it should they so wish. All that is required to gain access to the software is a computer connected to the Internet with a modern World-wide Web browser (of the sort you are probably using to read this). BCal d…
Bwigg
The integrated calibration of radiocarbon determinations and contextual information based on Bayesian statistical inference is known as 'Bayesian calibration'. Bayesian calibration was developed in the 1990s and there is software available, or under development, to perform various different types of applications: BCal, OxCal, Cal25 or CalPal; see also BCal, in Internet Archaeology. However, no software is available for performing fully Bayesian w…
The Comparison of 14 C Wiggle-Matching Results for the ‘Floating’ Tree-Ring Chronology of the Ulandryk-4 Burial Ground (Altai Mountains, Siberia)
Two independent 14 C data sets of 10 tree-ring samples from the longest master chronology of the Pazyryk cultural complex were obtained and wiggle-matched to the absolute timescale. The results show very good agreement, within 10–15 calendar yr. The Ulandryk-4 burial ground (mound 1) was dated to about 320–310 cal BC, and this is consistent with wiggle-matching of the Pazyryk burial ground date series
Testing the timing of radiocarbon-dated events between proxy archives
For interpreting past changes on a regional or global scale, the timings of proxy-inferred events are usually aligned with data from other locations. However, too often chronological uncertainties are ignored in proxy diagrams and multisite comparisons, making it possible for researchers to fall into the trap of sucking separate events into one illusionary event (or vice versa). Here we largely solve this ‘suck in and smear syndrome’ for radiocar…
A Bayesian Framework for Age Modeling of Radiocarbon-Dated Peat Deposits
Recently, Bayesian statistical software has been developed for age-depth modeling (“wiggle-match dating”) of sequences of densely spaced radiocarbon dates from peat cores. The method is described in non-statistical terms, and is compared with an alternative method of chronological ordering of 14 C dates. Case studies include the dating of the start of agriculture in the northeastern part of the Netherlands, and of a possible Hekla-3 tephra layer …
A New Robust Statistical Model for Radiocarbon Data
The general method currently used to analyze radiocarbon data ( y ) is conditional on the standard deviation (σ), reported by 14 C laboratories, which reflects the uncertainty in the dating process. This uncertainty is measured through a series of empirical as well as theoretical considerations about the dating process, chemical preprocessing, etc. Nevertheless, σ is assumed as known in the statistical model for 14 C data used since the dawn of t…
Random walk simulations of fossil proxy data
A wealth of palaeoecological studies (e.g. pollen, diatoms, chironomids and macrofossils from deposits such as lakes or bogs) have revealed major as well as more subtle ecosystem changes over decadal to multimillennial timescales. Such ecosystem changes are usually assumed to have been forced by specific environmental changes. Here, we test if the observed changes in palaeoecological records may be reproduced by random simulations, and we find th…
Flexible paleoclimate age-depth models using an autoregressive gamma process
Radiocarbon dating is routinely used in paleoecology to build chronologies of lake and peat sediments, aiming at inferring a model that would relate the sediment depth with its age. We present a new approach for chronology building (called "Bacon") that has received enthusiastic attention by paleoecologists. Our methodology is based on controlling core accumulation rates using a gamma autoregressive semiparametric model with an arbitrary number o…
Ams 14 C Dating of the Mayan Codex of Mexico Revisited
The Mayan Codex of Mexico (MCM), the only Mayan codex found in the 20th century, was unveiled in 1971 during the Ancient Maya Calligraphy exhibition at Club Grolier. The codex comprises 10 pages of bark paper in accordion format, coated with a layer of plaster on both sides. It illustrates the synodic cycles of Venus, with its four phases. Since its discovery, the MCM has been subject to controversy and discussions about its authenticity. In 2016…
Modelling chronologically ordered radiocarbon dates in R
Studies with multiple radiocarbon dates often contain useful information on the relative locations of the dated levels. Such information can be used to obtain robust, integrated site chronologies, with at times more precise ages than those of the individual dates, where outliers can be identified and downweighted, and where the ages of any undated levels can also be estimated. Examples include trees with radiocarbon dates separated by exactly kno…
Radiocarbon dating (11 works) · Archaeology and ancient environmental studies (10 works) · Archaeology (8 works) · Geology (8 works) · Mathematics (8 works) · Statistics (8 works) · Bayesian probability (7 works) · Computer Science (7 works) · Image Processing and 3D Reconstruction (7 works) · Paleontology (7 works)