Statistical and Type II Error Assessment of a Runoff Predictive Model in Peninsula Malaysia

Flood related disasters continue to threaten mankind despite preventative efforts in technological advancement. Since 1954, the Soil Conservation Services (SCS) Curve Number (CN0.2) rainfall-runoff model has been widely used but reportedly produced inconsistent results in field studies worldwide. As such, this article presents methodology to reassess the validity of the model and perform model calibration with inferential statistics. A closed form equation was solved to narrow previous research gap with a derived 3D runoff difference model for type II error assessment. Under this study, the SCS runoff model is statistically insignificant (alpha = 0.01) without calibration. Curve Number CN0.2 = 72.58 for Peninsula Malaysia with a 99% confidence interval range of 67 to 76. Within these CN0.2 areas, SCS model underpredicts runoff amounts when the rainfall depth of a storm is < 70 mm. Its overprediction tendency worsens in cases involving larger storm events. For areas of 1 km2, it underpredicted runoff amount the most (2.4 million liters) at CN0.2 = 67 and the rainfall depth of 55 mm while it nearly overpredicted runoff amount by 25 million liters when the storm depth reached 430 mm in Peninsula Malaysia. The SCS model must be validated with rainfall-runoff datasets prior to its adoption for runoff prediction in any part of the world. SCS practitioners are encouraged to adopt the general formulae from this article to derive assessment models and equations for their studies.

Performance Limitations in Sensorimotor Control: Trade-Offs Between Neural Computation and Accuracy in Tracking Fast Movements

The ability to move fast and accurately track moving objects is fundamentally constrained by the biophysics of neurons and dynamics of the muscles involved. Yet the corresponding trade-offs between these factors and tracking motor commands have not been rigorously quantified. We use feedback control principles to quantify performance limitations of the sensorimotor control system (SCS) to track fast periodic movements. We show that (1) linear models of the SCS fail to predict known undesirable phenomena, including skipped cycles, overshoot and undershoot, produced when tracking signals in the “fast regime,” while nonlinear pulsatile control models can predict such undesirable phenomena, and (2) tools from nonlinear control theory allow us to characterize fundamental limitations in this fast regime. Using a validated and tractable nonlinear model of the SCS, we derive an analytical upper bound on frequencies that the SCS model can reliably track before producing such undesirable phenomena as a function of the neurons' biophysical constraints and muscle dynamics. The performance limitations derived here have important implications in sensorimotor control. For example, if the primary motor cortex is compromised due to disease or damage, the theory suggests ways to manipulate muscle dynamics by adding the necessary compensatory forces using an assistive neuroprosthetic device to restore motor performance and, more important, fast and agile movements. Just how one should compensate can be informed by our SCS model and the theory developed here.

Coupling the MULTI-VP model with EUHFORIA

&lt;p&gt;The EUropean Heliospheric FORecasting Information Asset (EUHFORIA) is a new 3D magnetohydrodynamic (MHD) space weather prediction tool (Pomoell and Poedts, 2018). EUHFORIA models solar wind and coronal mass ejections (CMEs) all the way from the Sun to 2 AU. It consists of two different domains; the coronal part, which extends from the solar surface to 0.1 AU and the heliospheric part, which covers the spatial domain from 0.1 AU onwards. For the reconstruction of the global solar corona, the empirical Wang-Sheeley-Arge (WSA, Arge, 2003) model is currently used, in combination with the potential field source surface (PFSS) model and the Schatten current sheet (SCS) model, in order to reconstruct the magnetic field up to 0.1 AU and produce the plasma boundary conditions required by the 3D MHD heliospheric part to initiate. In the framework of the ongoing validation of the solar wind modeling with EUHFORIA, we implemented and tested a different coronal model, the so-called MULTI-VP model (Pinto and Rouillard, 2017). First results and comparisons of EUHFORIA modeled output at Earth produced by employing the WSA and MULTI-VP coronal models, will be presented.&lt;/p&gt;

Tracking control of ship course system using new six-step zead (Zhang et al discretization) formula with high precision

In this paper, firstly, a new six-step Zhang et al discretization (SSZeaD) formula is proposed, which is with the truncation error proportional to the fourth power of sampling period. Then, the SSZeaD formula is used to discretize a ship course system (SCS) for tracking control, and thus the SSZeaD-type SCS model is developed. For comparison purposes, the classical Euler forward formula (EFF) with the truncation error proportional to the first power of sampling period is also used to discretize the SCS, and thus the EFF-type SCS model is obtained. Besides, there is an important parameter called stepsize, which is closely related to the stability and the precision of the above two discrete-time models. In view of the importance of the stepsize, the effective stepsize domains of these two discrete-time models are confirmed by theoretical analyses. Finally, numerical experimental results well verify the higher tracking precision of the SSZeaD-type SCS model as compared with the EFF-type SCS model.

Realistic Anatomically Detailed Open-Source Spinal Cord Stimulation (RADO-SCS) Model

ObjectiveComputational current flow models of spinal cord stimulation (SCS) are widely used in device development, clinical trial design, and patient programming. Proprietary models of varied sophistication have been developed. An open-source model with state-of-the-art precision would serve as a standard for SCS simulation.ApproachWe developed a sophisticated SCS modeling platform, named Realistic Anatomically Detailed Open-Source Spinal Cord Stimulation (RADO-SCS) model. This platform consists of realistic and detailed spinal cord and ancillary tissues anatomy derived based on prior imaging and cadaveric studies. Represented tissues within the T9-T11 spine levels include vertebrae, intravertebral discs, epidural space, dura, CSF, white-matter, gray-matter, dorsal and ventral roots and rootlets, dorsal root ganglion, sympathetic chain, thoracic aorta, epidural space vasculature, white-matter vasculature, and thorax. As an exemplary, a bipolar SCS montage was simulated to illustrate the model workflow from the electric field calculated from a finite element model (FEM) to activation thresholds predicted for individual axons populating the spinal cord.Main ResultsCompared to prior models, RADO-SCS meets or exceeds detail for every tissue compartment. The resulting electric fields in white and gray-matter, and axon model activation thresholds are broadly consistent with prior stimulations.SignificanceThe RADO-SCS can be used to simulate any SCS approach with both unprecedented resolution (precision) and transparency (reproducibility). Freely available online, the RADO-SCS will be updated continuously with version control.

PREDIKSI DEBIT PUNCAK BANJIR DAERAH ALIRAN SUNGAI PADOLO DENGAN METODE SCS (SOIL CONSERVATION SERVICE)

Abstrak: Pada tahun 2016 di DAS Padolo Kota Bima telah terjadi banjir yang menggenangi 13 desa di 5 kecamatan. Penelitian ini bertujuan memprediksi berapa besar debit puncak banjir di DAS Padolo. Penelitian ini diharapkan dapat menjadi masukan dan sumber informasi terhadap solusi yang akan diambil dalam penanganan banjir. Prediksi debit puncak banjir menggunakan program HEC-HMS model SCS. Model hidrograf satuan sintesis SCS merupakan unit hidrograf berdimensi, dimana dapat mencapai puncak tunggal unit hidrograf. Metode SCS (SOIL CONSERVATION SERVICE) dihitung dengan kala ulang tahun 2, 10, 25, 50, dan 100 tahunan. Data hujan yang digunakan bersumber dari 2 stasiun hujan yaitu stasiun hujan Rasanae Timur dan Salahuddin. Hasil komputasi HEC-HMS model SCS untuk debit puncak banjir masing masing kala ulang 2 tahun sebesar 119,4 m3/s, 10 tahun sebesar 191 m3/s, 25 tahun sebesar 226,1 m3/s, 50 tahun sebesar 249,8 m3/s, dan 100 tahun sebesar 277,3 m3/s.Kata-kata kunci: banjir, DAS Padolo, metode SCS.

Analytical Solution for Solid Cylindrical Heat Source Model With Convective Boundary Condition

The energy pile technology has been widely used, and the solid cylindrical heat source (SCS) model is usually adopted to describe the heat transfer process between the energy pile and the surrounding soil. This paper investigates the SCS model with a convective boundary condition (SCS-3 model), and realistic conditions such as transversely isotropic ground and groundwater flow are all included in the model. An analytical solution for the problem is established using Green's function method and the theory of moving heat sources. Solutions for the SCS model with a boundary condition of the first kind (SCS-1 model) and for the line source (LS) model with a convective boundary condition (LS-3 model) are recovered as special cases of the solution in this paper. Computational examples are presented, and comparisons between different models are made. First, the SCS-1 model is compared with the SCS-3 model, showing the error caused by neglecting the surface convective effect. Second, the LS-3 model is compared with the SCS-3 model, showing the error associated with neglecting the size of heat source. The effects of groundwater flow velocity and convective heat transfer coefficient on the temporal and spatial variations of these errors are also investigated.

Evaluation of SCS - unit hydrograph model to estimate peak flows in watersheds of Norte de Santander

In several studies it is necessary to determine the magnitude of extreme flows in a river. Having an adequate register of observed discharge it is possible to adjust a probability density function (fdp) that allows estimating events associated with a high return period (i.e. 100 years). In ungauged basins, such as the majority of basins in the world are, other methodologies are used, such as the Synthetic Unity Hydrograph proposed by the United State Soil Conservation Service (UH-SCS). The UH-SCS model was evaluated in watersheds of the Norte de Santander department (COL), in its capacity to estimate extreme flows, and to explore its possible regionalization. The evaluation is done by comparing estimates of Q100, using the Frequency Factors method and the UH-SCS model. Discharge and precipitation time series were obtained from the IDEAM network, selecting 19 basins based on their drainage area, climatological stations density and records length. Geomorphology was characterized using ArcMap™ on the ASTER-GDEM digital elevation model. Using information available on geology, soils, vegetation cover, and assuming a wet antecedent moisture condition (AMC-III), values of the median of relative Q100 error (ε-Q100) of + 507% and + 406% were obtained for the fdp Gumbel and Log-Pearson. Using dry antecedent moisture condition (AMC-I) ε-Q100 low to + 36% and + 17%. It was possible to minimize ε-Q100 by calibrating the Curve Number (CN) parameter. A satisfactory regionalization function for CN was not found. Applying SCS-HU under AMC-III condition, Q100 is greatly overestimated. It is possible to minimize the error by considering AMC-I and reduce CN, a counter-intuitive situation since extreme flows are associated with wet weather conditions (i.e. Año Niña). Improvements in the characterization of rainfall and soils in Norte de Santander should be investigated.