scholarly journals Radiocarbon chronology of Andean khipus

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Alexander Cherkinsky ◽  
Gary Urton
Keyword(s):  
Three Dimensional ◽  
Calibration Data ◽  
Middle Horizon ◽  
Recording Technology ◽  
University Of Georgia ◽  
Inca Empire ◽  
Early Colonial ◽  
Late Horizon ◽  
The Usa ◽  
Radiocarbon Chronology

Unlike every other high civilisation of the ancient world, the Incas did not develop a system of writing based on graphic signs on twodimensional surfaces. Rather, Inca administrative records took the form of three-dimensional knotted-cords made of spun and plied fibers. It is widely believed that khipu technology associated with the rise and expansion of the Inca Empire, during the Late Horizon period (ca. 1400-1532 AD), developed out of an earlier cord recording technology associated with the Wari culture of the Middle Horizon period (ca. 600-1000 AD). There were good studies of the patterns of thread-wrapping on a few Middle Horizon samples and archaeological recovery of one sample from Middle Horizon context. Three Middle Horizon, Wari khipus have been dated between 780-1024 AD. The principal problem of khipu chronology arises with respect to the dating of Inca samples. Thirty-one samples of Inca khipus from museums in the USA, Latin America and Germany have been analysed. The samples were analysed by the accelerator mass spectrometry technique at three laboratories. About half of the samples analysed at the University of Georgia have been analysed twice to get a higher precision. Most of the samples have been dated from Late Horizon times to the early Colonial period, 1500-1600 AD. One of the samples was dated to the beginning of the Late Horizon 1390-1423 AD and another sample was even earlier, i.e. 1188-1282 AD. Unfortunately, the existing calibration data for Inca khipus do not allow high enough sensitivity for precise analysis, thereby requiring a reappraisal of the calibration curve for South America.

scholarly journals Comparing Locking Screw Direction Among Three Locking Plates for Lateral Clavicle Fractures: A Simulation Study

2020 ◽  
Author(s):  
Shingo Abe ◽  
Kota Koizumi ◽  
Toshiki Shimada ◽  
Tsuyoshi Murase ◽  
Kohji Kuriyama
Keyword(s):  
Sagittal Plane ◽  
Fragment Size ◽  
Three Dimensional ◽  
Locking Plates ◽  
Distal Clavicle ◽  
Inferior Surface ◽  
Locking Screws ◽  
Lateral Clavicle ◽  
The Usa ◽  
Clavicle Fractures

Abstract BackgroundThe current study aimed to measure screw angles of three locking plates for lateral clavicle fractures and to assess the numbers of screws that could be inserted per fragment size to elucidate the size limitation that could be fixed by locking plates.MethodsThe authors assessed three locking plates for lateral clavicle fractures: distal clavicle plate [Acumed, LLC, Oregon, the USA], LCP clavicle plate lateral extension [Depuy Synthes, LLC, MA, the USA], and HAI clavicle plate [HOMS Engineering, Inc., Nagano, Japan]. Using three-dimensional plate models, the angles between the most medial and lateral locking screws on the coronal plane and between the most anterior and posterior locking screws on the sagittal plane were measured. Two examiners independently performed computer simulation to position the plates as laterally as possible in the ten normal three-dimensional clavicle models. A lateral fragment size of 10, 15, 20, 25, and 30 mm was simulated in the acromioclavicular joint and the number of screws completely inserted in each size of the fragment in the simulation was assessed. Subsequently, the area covered by locking screws on the inferior surface of the clavicle was measured.ResultsThe distal clavicle plate had relatively large screw angles (20° on the coronal plane and 32° on the sagittal plane), and the LCP clavicle lateral extension had a large angle (38°) on the sagittal plane. However, the angle of the HAI clavicle plate was at maximum 13° on the coronal or sagittal plane. The distal clavicle plate indicated the largest numbers of screws that could be inserted in each size of the bone fragment. For all locking plates, all screws could be inserted within 25 mm fragments. Among all locking plates, the distal clavicle plate could cover the largest area on the inferior surface of the clavicle by the screws.ConclusionsScrew angles and the numbers of screws that could be inserted in the lateral fragment differed among products. Other augmented fixation procedures should be considered for fractures with fragment sizes <25 mm that could not be fixed with sufficient number of screws.

scholarly journals Transparent Object Shape Measurement Based on Deflectometry

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 548
Author(s):  
Zhichao Hao ◽  
Yuankun Liu
Keyword(s):  
Data Acquisition ◽  
Phase Measurement ◽  
Focal Length ◽  
Three Dimensional ◽  
Normal Direction ◽  
Calibration Data ◽  
Actual Measurement ◽  
Temporal Phase ◽  
Convex Lens ◽  
Normal Orientation

This paper proposes a method for obtaining surface normal orientation and 3-D shape of plano-convex lens using refraction stereo. We show that two viewpoints are sufficient to solve this problem under the condition that the refractive index of the object is known. What we need to know is that (1) an accurate function that maps each pixel to the refraction point caused by the refraction of the object. (2) light is refracted only once. In the simulation, the actual measurement process is simplified: light is refracted only once; and the accurate one-to-one correspondence between incident ray and refractive ray is realized by known object points. The deformed grating caused by refraction point is also constructed in the process of simulation. A plano-convex lens with a focal length of 242.8571 mm is used for stereo data acquisition, normal direction acquisition, and the judgment of normal direction consistency. Finally, restoring the three-dimensional information of the plano-convex lens by computer simulation. Simulation results suggest that our method is feasibility. In the actual experiment, considering the case of light is refracted more than once, combining the calibration data acquisition based on phase measurement, phase-shifting and temporal phase-unwrapping techniques to complete (1) calibrating the corresponding position relationship between the monitor and the camera (2) matching incident ray and refractive ray.

scholarly journals Spray Structure and Characteristics of a Pressure-Swirl Dust Suppression Nozzle Using a Phase Doppler Particle Analyze

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1127
Author(s):  
Junpeng Wang ◽  
Cuicui Xu ◽  
Gang Zhou ◽  
Yansong Zhang
Keyword(s):  
Particle Size ◽  
Velocity Distribution ◽  
Droplet Size ◽  
Three Dimensional ◽  
Calibration Data ◽  
Dust Suppression ◽  
Dust Fall ◽  
Spray Structure ◽  
Spray Field ◽  
Pressure Swirl

In order to understand the characteristics of the spray field of a dust suppression nozzle and provide a reference for dust nozzle selection according to dust characteristics, a three-dimensional phase Doppler particle analyzer (PDPA) spray measurement system is used to analyze the droplet size and velocity characteristics in a spray field, particularly the joint particle size–velocity distribution. According to the results, after the ejection of the jet from the nozzle, the droplets initially maintained some velocity; however, the distribution of particles with different sizes was not uniform. As the spray distance increased, the droplet velocity decreased significantly, and the particle size distribution changed very little. As the distance increased further, the large droplets separated into smaller droplets, and their velocity decreased rapidly. The distributions of the particle size and velocity of the droplets then became stable. Based on the particle size-velocity distribution characteristics, the spray structure of pressure-swirl nozzles can be divided into five regions, i.e., the mixing, expansion, stabilization, decay, and rarefied regions. The expansion, stabilization, and decay regions are the effective dust fall areas. In addition, the droplet size in the stabilization region is the most uniform, indicating that this region is the best dust fall region. The conclusions can provide abundant calibration data for spray dust fall nozzles.

Accelerating the Calibration of Multihole Pressure Probes by Applying Advanced Computational Methods

2005 ◽  
Vol 127 (3) ◽  
pp. 425-430 ◽  
Author(s):  
Arnoud R. C. Franken ◽  
Paul C. Ivey
Keyword(s):  
Computational Methods ◽  
Three Dimensional ◽  
Field Measurements ◽  
Cost Effective ◽  
Accurate Method ◽  
Pressure Probe ◽  
Calibration Data ◽  
Essential Information ◽  
Individual Probe ◽  
Probe Calibration

The miniature multihole pneumatic pressure probe is widely regarded as a cost-effective, easy-to-use, and accurate method for performing two- or three-dimensional flow field measurements in turbomachinery. The major downside to the use of these probes is that the influence of fabrication imperfections on probe characteristics necessitates an extensive and highly time-intensive and, therefore, costly calibration of each individual probe. Unless these probes can be fabricated to such standards that make individual probe calibrations superfluous, the only way to significantly reduce the time and costs associated with probe calibration is to shorten the calibration process. The latter is only possible if all essential information can be obtained from less calibration data. This paper describes an approach to the calibration of a series of multihole pressure probes in which advanced computational methods are used to make this possible. By exploiting the key features of a probe’s characteristic this approach requires only a fraction of the size of a conventional calibration database for the accurate modeling of the relationships between port pressures and flow conditions. As a result, calibration time and costs can be reduced without the sacrifice of quality.

Considerations for Using 3D Pneumatic Probes in High Speed Axial Compressors

2002 ◽  
Author(s):  
Simon Coldrick ◽  
Paul Ivey ◽  
Roger Wells
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Pressure Probe ◽  
Probe Type ◽  
Calibration Data ◽  
Axial Compressors ◽  
Close Proximity ◽  
Multistage Axial Compressor ◽  
Preparatory Work

This paper describes preparatory work towards three dimensional flowfield measurements downstream of the rotor in an industrial, multistage, axial compressor, using a pneumatic pressure probe. The probe is of the steady state four hole cobra probe type. The design manufacture and calibration of the probe is described. CFD calculations have been undertaken in order to assess the feasability of using such a probe in the high speed compressor environment where space is limited. This includes effects of mounting the probe in close proximity to the downstream stator blades and whether it is necessary to adjust the calibration data to compensate for these effects.

Industrial Democracy Under Liberal Capitalism: A Comparison of Trends in Australia, France and the USA

1978 ◽  
Vol 20 (4) ◽  
pp. 431-445 ◽  
Author(s):  
Russell D. Lansbury
Keyword(s):  
United States ◽  
Three Dimensional ◽  
The United States ◽  
Industrial Democracy ◽  
Labour Movement ◽  
The Usa ◽  
Enterprise Level ◽  
Liberal Capitalism ◽  
Degree Of Control

An examination is made of the trends toward new forms of industrial democracy in three liberal capitalist societies: France, the United States and Australia. A three-dimensional framework is introduced which uses the ideology of the labour movement, the degree of control which is sought by employees at the enterprise level and the level at which participation occurs, to compare developments in each country. It is argued that a convergence of approaches is occurring in these countries towards the participatory enterprise, albeit with some variations, within the framework of liberal capitalism.

scholarly journals Three Dimensional Brain Reconstruction Optimizes Surgical Approaches and Medical Education in Minimally Invasive Neurosurgery for Refractory Epilepsy

2021 ◽  
Vol 8 ◽  
Author(s):  
Arun Swaminathan
Keyword(s):  
Minimally Invasive ◽  
Refractory Epilepsy ◽  
Three Dimensional ◽  
Brain Structures ◽  
Surgical Approaches ◽  
Electrical Networks ◽  
Surgical Morbidity ◽  
Accurate Localization ◽  
Anatomical Correlation ◽  
The Usa

Epilepsy is a prevalent condition that affects 1–3% of the population or about 50–65 million people worldwide (WHO estimates) and about 3.5 million people in the USA alone (CDC estimates). Refractory epilepsy refers to patients that respond inadequately to medical management alone (at least two anti-seizure medications at appropriate doses) and are appropriate candidates for other interventions such as brain surgery or the use of neurostimulators for their epilepsy. Minimally invasive techniques like stereotactic EEG electrodes offer excellent investigational abilities to study the diagnostic attributes of the seizure networks, while therapies like laser ablations and neurostimulators permit intervention and modulation of these networks to offer seizure control with minimal cognitive compromise and surgical morbidity. The accuracy of these techniques is highly contingent on precise anatomical correlation between the location of the electrodes and their proximity to relevant structures of the brain. Ensuring good anatomical correlation using 3-dimensional (3D) reconstructions would permit precise localization and accurate understanding of the seizure networks. Accurate localization of stereotactic electrodes would enable precise understanding of the electrical networks and identify vital nodes in the seizure network. These reconstructions would also permit better understanding of the proximity of these electrodes to each other and help confirm arrangement of neurostimulators to maximize modulatory effects on the networks. Such reconstructions would enable better understanding of neuroanatomy and connectivity to improve knowledge of brain structures and relations in neurological conditions. These methods would enable medical students and doctors-in-training to better their understanding of neurological disease and the necessary interventions.

scholarly journals The FARM (Flexible Array of Radars and Mesonets)

2021 ◽  
pp. 1-88
Author(s):  
Joshua Wurman ◽  
Karen Kosiba ◽  
Brian Pereira ◽  
Paul Robinson ◽  
Andrew Frambach ◽  
...  
Keyword(s):  
Doppler Radar ◽  
Three Dimensional ◽  
Hazardous Substances ◽  
Dual Frequency ◽  
Weather Modification ◽  
Light Power ◽  
Wide Range ◽  
Precipitation Boundary ◽  
The Usa ◽  
Weather Stations

AbstractThe Flexible Array of Radars and Mesonets (FARM) Facility is an extensive mobile/quickly-deployable (MQD) multiple-Doppler radar and in-situ instrumentation network.The FARM includes four radars: two 3-cm dual-polarization, dual-frequency (DPDF), Doppler On Wheels DOW6/DOW7, the Rapid-Scan DOW (RSDOW), and a quickly-deployable (QD) DPDF 5-cm COW C-band On Wheels (COW).The FARM includes 3 mobile mesonet (MM) vehicles with 3.5-m masts, an array of rugged QD weather stations (PODNET), QD weather stations deployed on infrastructure such as light/power poles (POLENET), four disdrometers, six MQD upper air sounding systems and a Mobile Operations and Repair Center (MORC).The FARM serves a wide variety of research/educational uses. Components have deployed to >30 projects during 1995-2020 in the USA, Europe, and South America, obtaining pioneering observations of a myriad of small spatial and temporal scale phenomena including tornadoes, hurricanes, lake-effect snow storms, aircraft-affecting turbulence, convection initiation, microbursts, intense precipitation, boundary-layer structures and evolution, airborne hazardous substances, coastal storms, wildfires and wildfire suppression efforts, weather modification effects, and mountain/alpine winds and precipitation. The radars and other FARM systems support innovative educational efforts, deploying >40 times to universities/colleges, providing hands-on access to cutting-edge instrumentation for their students.The FARM provides integrated multiple radar, mesonet, sounding, and related capabilities enabling diverse and robust coordinated sampling of three-dimensional vector winds, precipitation, and thermodynamics increasingly central to a wide range of mesoscale research.Planned innovations include S-band On Wheels NETwork (SOWNET) and Bistatic Adaptable Radar Network (BARN), offering more qualitative improvements to the field project observational paradigm, providing broad, flexible, and inexpensive 10-cm radar coverage and vector windfield measurements.

The Inca State and Local Ritual Landscapes

2018 ◽  
Author(s):  
Zachary James Chase
Keyword(s):  
Local Elite ◽  
Inca Empire ◽  
Emergent Phenomena ◽  
Late Horizon ◽  
Imperial Expansion ◽  
State And Local ◽  
Over Time

Ritual landscapes were integral to Inca imperial expansion, both as a medium for and as a product of the interaction between the Inca state and regional and local polities. The incorporation of peoples and lands into the Inca Empire entailed complex dealings with local and regional huacas, together with the co-optation and modification of local elite lineages, corporate origins, and histories. Late Horizon ritual landscapes were thus emergent phenomena, constructed over time through processes of negotiation and reconfiguration between the Inca and other peoples. I refer to these negotiated landscapes as “local-imperial,” and explore these interactive processes through archaeological and ethnohistorical data from Cuzco, Pachacamac, Huamachuco, and Huarochirí. Inasmuch as local-imperial ritual landscapes were composite entities described in this article, viewing these different forms of evidence together clarifies our image of the Inca expansion as the work of physical, social, and symbolic-semiotic mastery.

Measurement of Large Flow Angles With Non-Nulling Multi-Hole Pressure Probes

2017 ◽  
Author(s):  
Martin J. Conlon ◽  
Alexander Wright ◽  
Hamza M. Abo El Ella
Keyword(s):  
Three Dimensional ◽  
Pressure Probe ◽  
Experimental Setup ◽  
Calibration Data ◽  
Complex Flow ◽  
Flow Disturbance ◽  
Hole Pressure ◽  
Analysis Strategy ◽  
Manufacturing Tolerances ◽  
Large Flow

In complex flow fields, the steady-state, three-dimensional attributes can be measured intrusively using a multi-hole pressure probe. These probes are built to be as small as possible to minimize flow disturbance, but the small size makes them susceptible to both manufacturing tolerances and fouling. As such, each probe must be calibrated on a regular basis and care must be taken to ensure that the geometry is not disturbed. The probes are operated in either “nulling” or “non-nulling” modes, the latter being the simpler of the two in terms of experimental setup and mechanical fixturing. This has made non-nulling mode the preferred choice for many years; however, non-nulling mode necessitates complete three-dimensional calibration data. Sector-based calibration strategies have become nearly universal, although improvement efforts continue. This paper presents a new calibration and data analysis strategy that gives shorter calibration times and more robust data reduction.

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