3,362 research outputs found
A model-based approach to correcting spectral irradiance data using an upward-looking airborne sensor (CASI ILS)
A number of aircraft sensors have the facility to measure spectral downwelling irradiance using a sensor mounted on the roof of the aircraft, but these data are rarely used for atmospheric correction. Part of the problem is that the attitude of the airborne platform is always changing during flight, even in stable conditions, so that direct use of data from an incident light sensor (ILS) can introduce errors into atmospheric correction methods. The continual motion of the ILS is used here to advantage, as a means to fit a sky radiance distribution model developed by Brunger and Hooper (1993) to data from the Itres Instruments CASI ILS. The inclination of the ILS sensor, due to changing aircraft attitude, is considered as
the slope plane in the model. The selected model coefficients correspond to parameterised atmospheric conditions and represent atmospheric transmission and the proportion of direct:diffuse flux. The method was used to correct CASI ILS data acquired over a site in southern England. Comparison with spectral irradiance measured simultaneously on the ground shows that the method reduced the variability of the ILS data and also compensated for the effect of different flight directions. The sky radiance distribution at sensor level is also calculated by
the model, and shows the characteristics of the sky conditions at the time of each flight
Retrieval of at-sensor irradiance using Incident Light Sensor (ILS)
A number of aircraft sensors have the facility to measure spectral downwelling irradiance using a sensor mounted on the roof of the aircraft, but these data are rarely used for atmospheric correction.
Part of the problem is that the attitude of the airborne platform is always changing during flight, even in stable conditions, so that direct use of data from an incident light sensor (ILS) can introduce errors into atmospheric correction methods.
The continual motion of the ILS is used here to advantage, as a means to fit a sky radiance distribution model developed by Brunger and Hooper (1993) to data from the Itres Instruments CASI ILS. The inclination of the ILS sensor, due to changing aircraft attitude, is considered as the slope plane in the model. The selected model coefficients correspond to parameterised atmospheric conditions, i.e. clearness index and diffuse ratio. The ILS data corrected by the model are wellmatched
to variations of irradiance measured at ground level during three flights. The radiance distribution at sensor level is also calculated by the model, and shows the characteristics of the sky conditions at the time of each flight
Non-thermal WIMP baryogenesis
We propose a WIMP baryogensis achieved by the annihilation of non-thermally
produced WIMPs from decay of heavy particles, which can result in low reheating
temerature. Dark matter (DM) can be produced non-thermally during a reheating
period created by the decay of long-lived heavy particle, and subsequently
re-annihilate to lighter particles even after the thermal freeze-out. The
re-annihilation of DM provides the observed baryon asymmetry as well as the
correct relic density of DM. We investigate how wahout effects can affect the
generation of the baryon asymmetry and study a model suppressing them. In this
scenario, we find that DM can be heavy enough and its annihilation cross
section can also be larger than that adopted in the usual thermal WIMP
baryogenesis.Comment: 5 pages, 6 figure
Probing the messenger of supersymmetry breaking by the muon anomalous magnetic moment
Motivated by the recently measured muon's anomalous magnetic moment
, we examine the supersymmetry contribution to in various
mediation models of supersymmetry breaking which lead to predictive flavor
conserving soft parameters at high energy scale. The studied models include
dilaton/modulus-mediated models in heterotic string/ theory, gauge-mediated
model, no-scale or gaugino-mediated model, and also the minimal and deflected
anomaly-mediated models. For each model, the range of allowed
by other experimental constraints, e.g. b --> s\gamma and the collider bounds
on superparticle masses, is obtained together with the corresponding parameter
region of the model. Gauge-mediated models with low messenger scale can give
any within the bound. In many other models, b -->
s\gamma favors smaller than either the value
() or the central value ().Comment: RevTeX, 29 pages, 14 eps figures, figure for deflected anomaly
mediation is corrected, reference adde
Recommended from our members
Performance Debugging Frameworks for FPGA High-Level Synthesis
Using high-level synthesis (HLS) tools for field-programmable gate array (FPGA) design is becoming an increasingly popular choice because HLS tools can generate a high-quality design in a short development time. However, current HLS tools still cannot adequately support users in understanding and fixing the performance issues of the current design. That is, current HLS tools lack in performance debugging capability. Previous work on performance debugging automates the process of inserting hardware monitors in low-level register-transfer level (RTL) languages which limits the comprehensibility of the obtained result. Instead, our HLS-based flows offer analysis on a function or loop level and provide more intuitive feedback that can be used to pinpoint the performance bottleneck of a design. In this dissertation, we present a collection of HLS-based debugging frameworks for various purposes and characteristics of the design. First, we address the problem in the HLS synthesis step, where an inaccurate cycle estimation is provided if the program has input-dependent behavior. We propose a new performance estimator that automatically instruments code that models the hardware execution behavior and interprets the information from the HLS software simulation. However, the performance estimation result of this flow may not be accurate for a type of designs that cannot be simulated correctly by existing HLS software simulators. To handle such cases, we propose a new software simulator that provides cycle-accurate result based on the HLS scheduling information. If the input dataset is not available for software simulation or high-level models do not exist for all components of the FPGA design, we also present an on-board monitoring flow for automated cycle extraction and stall analysis. Finally, we address the needs of HLS programmers to automatically find the best set of directives for FPGA designs. We propose a design space exploration (DSE) framework to optimize applications with variable loop bounds in Polybench benchmark. A quantitative comparison among the proposed frameworks is shown using the sparse matrix-vector multiplication benchmark
Gas-Filled Phospholipid Nanoparticles Conjugated with Gadolinium Play a Role as a Potential Theragnostics for MR-Guided HIFU Ablation
To develop a long-circulating theragnostics, meaning therapeutics and diagnostics for MR-guided HIFU ablation, we designed and prepared Gd-C5F12-phospholipid nanobubbles (PLNs) 30–100 nm in diameter. The biochemical and physical characterization of Gd-C5F12-PLNs were performed. Since Gd-C5F12-PLN-50 (Φ = 50 nm) and Gd-C5F12-PLN-100 (Φ = 100 nm) enhanced the hyperthermal effect of HIFU size- and concentration-dependently in a tissue-mimicking phantom, its circulation, distribution, tumor accumulation and tumor ablation were examined in tumor-bearing mice. The plasma-half life of Gd-C5F12-PLNs was longer than 1.5 hrs. Gd-C5F12-PLNs mainly accumulated in the liver and the spleen, suggesting that they are slowly secreted through the hepatobiliary pathway. Monitored by the T1 signal intensity of MR, Gd-C5F12-PLNs accumulated in tumor tissues for 8 hours in mice. HIFU with Gd-C5F12-PLN-100 showed the increased tumor ablation area as compared with HIFU alone. The results suggest that Gd-C5F12-PLNs exhibit a potential theragnostics for MR-guided HIFU ablation
- …