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2005

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Articles 1471 - 1500 of 5573

Full-Text Articles in Physical Sciences and Mathematics

Geospatial Decision Support For Drought Risk Management, Steve Goddard, Sherri K. Harms, Stephen E. Reichenbach, Tsegaye Tadesse, William J. Waltman Jul 2005

Geospatial Decision Support For Drought Risk Management, Steve Goddard, Sherri K. Harms, Stephen E. Reichenbach, Tsegaye Tadesse, William J. Waltman

School of Computing: Faculty Publications

Drought affects virtually all regions of the world and results in significant economic, social, and environmental impacts. The Federal Emergency Management Agency estimates annual drought-related losses in the U.S. at $6–$8 billion, which is more than any other natural hazard. Congress enacted the Agricultural Risk Protection Act of 2000 to encourage the U.S. Department of Agriculture (USDA) Risk Management Agency (RMA) and farmers to be more proactive in managing drought risk. Through the NSF’s Digital Government Program, the USDA RMA is working with the University of Nebraska–Lincoln Computer Science and Engineering Department, National Drought Mitigation Center (NDMC), and High Plains …


Tris(Ethylenediamine)Cobalt(Iii) Nonaiododibismuthate, Andrea M. Goforth, Rachael E. Hipp, Mark D. Smith, Leroy Peterson Jr., Hans-Conrad Zur Loye Jul 2005

Tris(Ethylenediamine)Cobalt(Iii) Nonaiododibismuthate, Andrea M. Goforth, Rachael E. Hipp, Mark D. Smith, Leroy Peterson Jr., Hans-Conrad Zur Loye

Faculty Publications

The asymmetric unit of the title compound, [Co(C2H8N2)3][Bi2I9], crystallizes in the orthorhombic space group Cmc21. The asymmetric unit contains half of a [Co(en)3]3+ cation (en is ethylenediamine) and half of a [Bi2I9]3- anion. Both species are located on mirror planes, requiring the [Co(en)3]3+ cation to be present as a statistically disordered mixture of both enantiomeric forms. Crystals were grown solvothermally from an ethanol-water solvent mixture using rac-[Co(en)3]I3 and bismuth triiodide …


Mathematics, Meaning, And Identity : A Study Of The Practice Of Mathematics Education In A Rural High School, Rick Anderson Jul 2005

Mathematics, Meaning, And Identity : A Study Of The Practice Of Mathematics Education In A Rural High School, Rick Anderson

Dissertations and Theses

The purposes of this study were (1) to explore the relationship between mathematics education and the rural context and (2) to determine the usefulness of a social theory of learning (Wenger, 1998) to account for students' participation in advanced high school mathematics courses. Qualitative methods were used to gather data in a small, rural high school in the Pacific Northwest. Data gathered included a student survey, interviews with students and mathematics teachers, observations in mathematics classes, and documents related to the curriculum, the school, and the community.

The findings suggest that high school mathematics education is related to the rural …


Two-Dimensional Self-Assembly In Diblock Copolymers, Anette E. Hosoi, Dmitriy Kogan '03, Caitlin E. Devereaux '02, Andrew J. Bernoff, Shenda M. Baker Jul 2005

Two-Dimensional Self-Assembly In Diblock Copolymers, Anette E. Hosoi, Dmitriy Kogan '03, Caitlin E. Devereaux '02, Andrew J. Bernoff, Shenda M. Baker

All HMC Faculty Publications and Research

Diblock copolymers confined to a two-dimensional surface may produce uniform features of macromolecular dimensions (∼10–100  nm). We present a mathematical model for nanoscale pattern formation in such polymers that captures the dynamic evolution of a solution of poly(styrene)-b-poly(ethylene oxide), PS-b-PEO, in solvent at an air-water interface. The model has no fitting parameters and incorporates the effects of surface tension gradients, entanglement or vitrification, and diffusion. The resultant morphologies are quantitatively compared with experimental data.


Cooling Rate Effects On Paleointensity Estimates In Submarine Basaltic Glass And Implications For Dating Young Flows, Julie A. Bowles, Jeffrey S. Gee, Dennis V. Kent, Eric Bergmanis, John Sinton Jul 2005

Cooling Rate Effects On Paleointensity Estimates In Submarine Basaltic Glass And Implications For Dating Young Flows, Julie A. Bowles, Jeffrey S. Gee, Dennis V. Kent, Eric Bergmanis, John Sinton

Geosciences Faculty Articles

Cooling rate effects on the intensity of thermoremanent magnetization (TRM) have been well documented in ceramics. In that case, laboratory cooling is generally more rapid than the initial cooling, leading to an overestimate of the paleofield by 5–10% in Thellier-type paleointensity experiments. The reverse scenario, however, has never been tested. We examine the effects of cooling rate on paleointensity estimates from rapidly quenched submarine basaltic glass (SBG) samples from 13 sites at 17°30′–18°30′S on the East Pacific Rise. Absolute cooling rates determined by relaxation geospeedometry at five of these sites range from ~10 to ~330°C min^-1 at the glass transition …


Concurrent Ohimager And Sodium Temperature/Wind Lidar Observation Of Localized Ripples Over Northern Colorado, L. Tao, C. Y. She, B. P. Williams, Tao Yuan, R. L. Collins, L. Kieffabar, A. Peterson Jul 2005

Concurrent Ohimager And Sodium Temperature/Wind Lidar Observation Of Localized Ripples Over Northern Colorado, L. Tao, C. Y. She, B. P. Williams, Tao Yuan, R. L. Collins, L. Kieffabar, A. Peterson

All Physics Faculty Publications

On 3 and 5 September 2002 the OH all-sky imager at Platteville, Colorado (40.2°N, 104.7°W), observed small-scale, wavelike patterns (known as ripples), with horizontal wavelengths of ∼9 km and ∼7 km and lifetimes of ∼9 min and ∼15 min, respectively. The Colorado State University sodium lidar at nearby Fort Collins, Colorado (40.6°N, 105°W), also made concurrent observations of temperature and zonal and meridional winds, which allowed us to determine the nature of the ripples observed. Our observations suggest that the 3 September ripple was induced by a convective instability located at 87.5 km and the 5 September ripple was induced …


Introducing Location-Based Services Into Information Technology Curriculum: Reflections On Practice, Katina Michael, Holly Tootell Jul 2005

Introducing Location-Based Services Into Information Technology Curriculum: Reflections On Practice, Katina Michael, Holly Tootell

Faculty of Informatics - Papers (Archive)

This paper describes how location-based services (LBS) was introduced into the information technology curriculum at the University of Wollongong in 2004. The inquiry is based on two academic reflections on practice. The results indicate that students found the course experience both intellectually challenging and rewarding. Academics linked to the project found the topic aligned well to their research interests and stimulated new ideas for grant applications. And industry representatives found the experience advantageous, a vehicle for collaboration, and subsequently a way to give something back to their local community. In summary the dynamic exchange of knowledge between staff, students, and …


The Pros And Cons Of Rfid In Supply Chain Management, Katina Michael, Luke Mccathie Jul 2005

The Pros And Cons Of Rfid In Supply Chain Management, Katina Michael, Luke Mccathie

Faculty of Informatics - Papers (Archive)

This paper presents the pros and cons of using radio-frequency identification (RFID) in supply chain management (SCM). While RFID has a greater number of benefits than its predecessor, the bar code, it currently comes at a price that many businesses still consider prohibitive. On the one hand, RFID is advantageous because it does not require line-of-sight scanning, it acts to reduce labor levels, enhances visibility, and improves inventory management. On the other hand, RFID is presently a costly solution, lacking standardization, it has a small number of suppliers developing end-to-end solutions, suffers from some adverse deployment issues, and is clouded …


Effects Of Hurricane Fault Architecture On Groundwater Flow In The Timpoweap Canyon Of Southwestern, Utah, Sarah J. Dutson Jul 2005

Effects Of Hurricane Fault Architecture On Groundwater Flow In The Timpoweap Canyon Of Southwestern, Utah, Sarah J. Dutson

Theses and Dissertations

Hydrogeologically important features of fault zones include undamaged country rock, the damage zone, and the core zone. Fault cores generally have low porosity and permeability, and often act as a barrier to groundwater flow. The damage zone, by contrast, consists of small faults and fracture networks, which can act as conduits. Timpoweap Canyon near Hurricane, Utah has superb exposures of the fault core and damage zone of the Hurricane Fault. Also within the canyon, springs discharge from the damage zone into the Virgin River, providing an ideal natural laboratory for the study of groundwater discharge from a fault zone. The …


Establishing Public Confidence In The Viability Of Fingerprint Biometric Technology, Nathan Alan Green Jul 2005

Establishing Public Confidence In The Viability Of Fingerprint Biometric Technology, Nathan Alan Green

Theses and Dissertations

The most common personal authentication techniques used for identity management employ a secret PIN or password that must be remembered. The challenge, for a given user, is that a multitude of such codes must be recalled over the course of the day for transactions involving distinct computer applications. Password mania prevails. Fingerprint biometric technology is an ideal alternate solution to this password recall problem. In spite of their availability for nearly thirty years, fingerprint biometric systems still remain uncommon in public sectors of industry such as education, government, and technology. Technology has improved sufficiently that false acceptance and rejection rates …


Pulsar Timing And The Detection Of Black Hole Binary Systems In Globular Clusters, Fredrick A. Jenet, Teviet Creighton, Andrea Lommen Jul 2005

Pulsar Timing And The Detection Of Black Hole Binary Systems In Globular Clusters, Fredrick A. Jenet, Teviet Creighton, Andrea Lommen

Physics and Astronomy Faculty Publications and Presentations

The possible existence of intermediate-mass binary black holes (IMBBHs) in globular clusters (GCs) offers us a unique geometry in which to detect spacetime oscillations. For certain pulsar-IMBBH configurations possible within a GC, the usual far-field plane wave approximation for the IMBBH metric perturbation severely underestimates the induced pulse time-of-arrival (TOA) fluctuations. In this Letter, the expected TOA fluctuations induced by an IMBBH lying close to the line of sight between a pulsar and the Earth are calculated for the first time. For an IMBBH consisting of 10 and 103 M⊙ components, a 10 yr orbital period, and located 0.1 lt-yr …


Search For Anomalous Kinematics In Tt̅ Dilepton Events At Cdf Ii, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Jul 2005

Search For Anomalous Kinematics In Tt̅ Dilepton Events At Cdf Ii, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report on a search for anomalous kinematics of tt̅ dilepton events in pp̅ collisions at √s =1.96 TeV using 193 pb-1 of data collected with the CDF II detector. We developed a new a priori technique designed to isolate the subset in a data sample revealing the largest deviation from standard model (SM) expectations and to quantify the significance of this departure. In the four-variable space considered, no particular subset shows a significant discrepancy, and we find that the probability of obtaining a data sample less consistent with the SM than what is observed is 1.0%–4.5%.


Positive Solutions For The Beam Equation Under Certain Boundary Conditions, Bo Yang Jul 2005

Positive Solutions For The Beam Equation Under Certain Boundary Conditions, Bo Yang

Faculty Articles

We consider a boundary-value problem for the beam equation, in which the boundary conditions mean that the beam is embedded at one end and fastened with a sliding clamp at the other end. Some priori estimates to the positive solutions for the boundary-value problem are obtained. Sufficient conditions for the existence and nonexistence of positive solutions for the boundary-value problem are established


A Mathematical Model Of Adhesion Interactions Between Living Cells, Casey P. Johnson Jul 2005

A Mathematical Model Of Adhesion Interactions Between Living Cells, Casey P. Johnson

Theses and Dissertations

This thesis presents a simple force-based model of moving and interacting cells that incorporates a realistic description of cell adhesion and applies it to a system of spherical cells. In addition, several results in matrix theory are proved with the end of showing that the equations produced by the model uniquely determine the motion of the system or cells.


Representations For Understanding The Stern-Gerlach Effect, Jared R. Stenson Jul 2005

Representations For Understanding The Stern-Gerlach Effect, Jared R. Stenson

Theses and Dissertations

The traditional explanation of the Stern-Gerlach effect carries with it several very subtle assumptions and approximations. We point out the degree to which this fact has affected the way we practice and interpret modern physics. In order to gain a more complete understanding of the Stern-Gerlach effect beyond the standard approximations and assumptions it typically carries, we introduce the inhomogeneous Stern-Gerlach effect in which the strong uniform field component is removed. This change allows us to easily identify precession as a critical concept. It also provides us with a means by which to study precession and analyze it critically. By …


Holocene Hydrologic Variation At Lake Titicaca, Bolivia/Peru, And Its Relationship To North Atlantic Climate Variation, P. A. Baker, Sherilyn C. Fritz, J. Garland, E. Ekdahl Jul 2005

Holocene Hydrologic Variation At Lake Titicaca, Bolivia/Peru, And Its Relationship To North Atlantic Climate Variation, P. A. Baker, Sherilyn C. Fritz, J. Garland, E. Ekdahl

Department of Earth and Atmospheric Sciences: Faculty Publications

A growing number of sites in the Northern Hemisphere show centennial- to millennial-scale climate variation that has been correlated with change in solar variability or with change in North Atlantic circulation. However, it is unclear how (or whether) these oscillations in the climate system are manifest in the Southern Hemisphere because of a lack of sites with suitably high sampling resolution. In this paper, we reconstruct the lake-level history of Lake Titicaca, using the carbon isotopic content of sedimentary organic matter, to evaluate centennial-to millennial-scale precipitation variation and its phasing relative to sites in the Northern Hemisphere. The pattern and …


Measurement Of The Cross Section For Prompt Diphoton Production In Pp̅ Collisions At √S =1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Jul 2005

Measurement Of The Cross Section For Prompt Diphoton Production In Pp̅ Collisions At √S =1.96 Tev, Darin Acosta, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report a measurement of the rate of prompt diphoton production in pp̅ collisions at √s =1.96 TeV using a data sample of 207 pb-1 collected with the upgraded Collider Detector at Fermilab. The background from nonprompt sources is determined using a statistical method based on differences in the electromagnetic showers. The cross section is measured as a function of the diphoton mass, the transverse momentum of the diphoton system, and the azimuthal angle between the two photons and is found to be consistent with perturbative QCD predictions.


Black Spaghetti: A Numerical Model Of Gravitational Collapse In 4 + 1 Spacetime, Michael P. Christenson Jul 2005

Black Spaghetti: A Numerical Model Of Gravitational Collapse In 4 + 1 Spacetime, Michael P. Christenson

Theses and Dissertations

We investigate spherically-symmetric gravitational collapse in the presence of a single "large" extra dimension through the use of analytical and numerical techniques. This has bearing on higher-dimensional ideas concerning hypothetical objects called "black strings," or black holes extending into an extra circular dimension, which dimension we hereinafter label zeta. These putative objects were first seriously considered as elements of string theory but have relevance in simpler, higher-dimensional generalization of Einstein's general relativity. We assume a universe topologically consisting of a two-dimensional Lorentzian manifold crossed with the sphere, crossed again with the circle. We model the formation of a uniform black …


An Improved Flexible Neutron Detector For Powder Diffraction Experiments, Thomas Kevin Mcknight Jul 2005

An Improved Flexible Neutron Detector For Powder Diffraction Experiments, Thomas Kevin Mcknight

Theses and Dissertations

Large amounts of money are being applied to the construction of the next generation of spallation sources for neutron scattering. Neutron powder diffraction instruments will be an important element of these facilities and the incorporation of detectors into these instruments with a high neutron capture efficiency is desirable. A new detector design named the Flexible Embedded Fiber Detector (FEFD) has been developed and tested for this thesis. This detector is based on wavelength shifting fibers embedded in a zinc-sulfide lithium-fluoride based scintillator. The virtue of this design is that the detecting surface can be curved around the Debye-Scherrer rings. This …


Accelerated Ray Traced Animations Exploiting Temporal Coherence, Darwin Tarry Baines Jul 2005

Accelerated Ray Traced Animations Exploiting Temporal Coherence, Darwin Tarry Baines

Theses and Dissertations

Ray tracing is a well-know technique for producing realistic graphics. However, the time necessary to generate images is unacceptably long. When producing the many frames that are necessary for animations, the time is magnified. Many methods have been proposed to reduce the calculations necessary in ray tracing. Much of the effort has attempted to reduce the number of rays cast or to reduce the number of intersection calculations. Both of these techniques exploit spatial coherence. These acceleration techniques are expanded not only to exploit spatial coherence but also to exploit temporal coherence in order to reduce calculations by treating animation …


Novel Neutron Detector For N-N Scattering Length Measurement, Eva Wilcox Jul 2005

Novel Neutron Detector For N-N Scattering Length Measurement, Eva Wilcox

Theses and Dissertations

The neutron-neutron (n-n) scattering length is a fundamental parameter in nuclear physics; however, measurements are plagued with large uncertainties caused by neutron detector cross talk. Many experimentalists also rely upon computer code to calibrate their neutron detectors. Experiments give one of two different numbers but there is still no adequate explanation for this discrepancy. We have developed a new neutron detector expressly for the purpose of improving the n-n scattering length measurement. It offers two important advantages: 1) minimal cross talk and 2) high counting efficiency. We calibrated the detector from 1 MeV to 6 MeV at 1 MeV increments. …


Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements: Quarterly Progress Report (March – May 2005), Ajit K. Roy Jul 2005

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements: Quarterly Progress Report (March – May 2005), Ajit K. Roy

Transmutation Sciences Materials (TRP)

Accomplishments:

● Analyses of defects (dislocations) in martensitic Alloy EP-823, cold-reduced to different levels, have been performed by using transmission electron microscopy. The dislocation density has been related to the degree of cold-reduction and residual stress in terms of a line-shape parameter determined by the positron annihilation spectroscopy (PAS).

● Additional PAS measurements are ongoing on tensile, welded and cold-worked specimens of Alloys EP-823 and HT-9 at the Idaho Accelerator Center of ISU. Both Subhra and Silpa are involved in these measurements.

● Silpa is performing neutron diffraction (ND) measurements at the Atomic Energy of Canada Limited (AECL), Chalk River …


Task Localization, Similarity, And Transfer; Towards A Reinforcement Learning Task Library System, James Lamond Carroll Jul 2005

Task Localization, Similarity, And Transfer; Towards A Reinforcement Learning Task Library System, James Lamond Carroll

Theses and Dissertations

This thesis develops methods of task localization, task similarity discovery, and task transfer for eventual use in a reinforcement learning task library system, which can effectively “learn to learn,” improving its performance as it encounters various tasks over the lifetime of the learning system.


Library World Wide Web Sites At Medium-Sized Universities : A Re-Examination, Bradley P. Tolppanen, Joan Miller, Martha H. Wooden, Lori M. Tolppanen Jul 2005

Library World Wide Web Sites At Medium-Sized Universities : A Re-Examination, Bradley P. Tolppanen, Joan Miller, Martha H. Wooden, Lori M. Tolppanen

Bradley P. Tolppanen

No abstract provided.


Development Of A Web Based Inventory Management System For A Small Retail Business, Chiranjib Sanyal Jul 2005

Development Of A Web Based Inventory Management System For A Small Retail Business, Chiranjib Sanyal

Regis University Student Publications (comprehensive collection)

This project proposes a technical solution that will improve the inventory management for a small business company. The project envisions a situation where a company currently uses a client server based inventory management system in each store. The current system depends upon the store managers for inventory control functions like purchase order creation and inventory usage recording. Currently, each store sends the inventory consumption and ordering information to the corporate office on a weekly basis. As a result, the corporate office doesn't get up-to-date information on inventory level in the stores on a daily basis. Also, there is no established …


Suitability Of The Nist Shop Data Model As A Neutral File Format For Simulation, Gregory Brent Harward Jul 2005

Suitability Of The Nist Shop Data Model As A Neutral File Format For Simulation, Gregory Brent Harward

Theses and Dissertations

Due to the successful application in internet related fields, Extensible Markup Language (XML) and its related technologies are being explored as a revolutionary software file format technology used to provide increased interoperability in the discrete-event simulation (DES) arena. The National Institute of Standards and Technology (NIST) has developed an XML-based information model (XSD) called the Shop Data Model (SDM), which is used to describe the contents of a neutral file format (NFF) that is being promoted as a means to make manufacturing simulation technology more accessible to a larger group of potential customers. Using a two step process, this thesis …


Effect Of Silicon Content On The Corrosion Resistance And Radiation-Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems: Quarterly Progress Report (February – April 2005), Ajit K. Roy Jul 2005

Effect Of Silicon Content On The Corrosion Resistance And Radiation-Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems: Quarterly Progress Report (February – April 2005), Ajit K. Roy

Transmutation Sciences Materials (TRP)

This proposal is intended to study the effect of Si content not only on the corrosion resistance but also on the radiation-induced embrittlement of martensitic stainless steels. The susceptibility of these alloys with different Si content to stress corrosion cracking, general corrosion and localized corrosion will be evaluated in the molten LBE and aqueous environments of different pH values using state-of-the-art testing techniques. Testing in the aqueous media is intended to develop baseline data for comparison purpose. Radiation-induced embrittlement of these alloys will initially be studied by irradiating the test specimens with bremmstrahlung gamma radiation from 20-40 MeV electron beams …


Gps Velocity Field In The Transition From Subduction To Collision Of The Eastern Sunda And Banda Arcs, Indonesia, Hendro Nugroho Jul 2005

Gps Velocity Field In The Transition From Subduction To Collision Of The Eastern Sunda And Banda Arcs, Indonesia, Hendro Nugroho

Theses and Dissertations

Campaign GPS measurements during 2001-2003 in the transition between subduction and collision of the Banda arc reveal how strain is partitioned away from the trench and distributed to other parts of the arc-trench system. Genrich, et. al. (1996) conducted a GPS campaign (1992-1994) throughout the Eastern Sunda and Banda arcs that demonstrated partial accretion of the arc to the Australian plate. We reoccupied many of the sites from this earlier study and 7 additional stations, 3 of which are new benchmarks. Our study shortened many baselines and extended the observation epoch to ten years for many key stations. The resulting …


Long-Term Surface Uplift History Of The Active Banda Arc-Continent Collision: Depth And Age Analysis Of Foraminifera From Rote And Savu Islands, Indonesia, Nova Roosmawati Jul 2005

Long-Term Surface Uplift History Of The Active Banda Arc-Continent Collision: Depth And Age Analysis Of Foraminifera From Rote And Savu Islands, Indonesia, Nova Roosmawati

Theses and Dissertations

Analysis of foraminifera for synorogenic pelagic units of Rote and Savu Islands, Indonesia, reveals high rates of surface uplift in the past 1.5 Ma of the incipient Banda arc-continent collision. Paleodepth estimates are derived from benthonic forams and ages from planktonic forams. But estimates are complicated, however, by abundant reworking; yet several distinctive species have been found. Synorogenic deposits in western Rote yield forams of biozone Neogene (N) 18 and depths from 5000-5700 meters at the base of the section, and 3600 meters at the top of the section. Eastern Rote yields forams of N 19/20 - N 22 and …


Real-Time Power Aware Routing In Wireless Sensor Networks, Octav Chipara, Zhimin He, Guoliang Xing, Qin Chen, Xiaorui Wang, Chenyang Lu, John Stankovic, Tarek Abdelzaher Jul 2005

Real-Time Power Aware Routing In Wireless Sensor Networks, Octav Chipara, Zhimin He, Guoliang Xing, Qin Chen, Xiaorui Wang, Chenyang Lu, John Stankovic, Tarek Abdelzaher

All Computer Science and Engineering Research

Many mission-critical wireless sensor network applications must resolve the inherent conflict between the tight resource constraints on each sensor node, particularly in terms of energy, with the need to achieve desired quality of service such as end-to-end real-time performance. To address this challenge we propose the Real-time Power-Aware Routing (RPAR) protocol. RPAR achieves required communication delays at minimum energy cost by dynamically adapting the transmission power and routing decisions based on packet deadlines. RPAR integrates a geographic forwarding policy cognizant of deadlines, power, and link quality with new algorithms for on-demand power adaptation and efficient neighborhood discovery. Simulations based on …