Comparative Study of Energy Savings for Various Control Strategies in the Tunnel Lighting System

Tunnel lighting is the most significant component in total energy consumption in the whole infrastructure. Hence, various lighting control strategies based on light-emitting diode (LED) technology have been investigated to conserve energy by decreasing luminaires’ operating time. In this study, four kinds of tunnel lighting control strategies and the development of their associated technologies are evaluated: no-control low-consumption lamps (LCL), time-scheduling control strategy (TSCS), daylight adaptation control strategy (DACS), and intelligent control strategy (ICS). This work investigates the relationship between initial investment and electrical costs as a function of tunnel length (L) and daily traffic volume (N) for the four control strategies. The analysis was performed using 100-day data collected in eleven Chinese tunnels. The tunnel length (L) ranged from 600 m to 3300 m and the daily traffic volume (N) ranged from 700 to 2500. The results showed that initial investment costs increase with L for all control strategies. Also, the electricity costs for the LCL, TSCS, and DACS strategies increased linearly with L, whereas the electricity cost for the ICS strategy has an exponential growth with L and N. The results showed that for a lifetime equal to or shorter than 218 days, the LCL strategy offered the best economical solution; whereas for a lifetime longer than 955 days, the ICS strategy offered the best economical solution. For a lifetime between 218 and 955 days, the most suitable strategy varies with tunnel length and traffic volume. This study’s results can guide the decision-making process during the tunnel lighting system’s design stage.Zhejiang Provincial Natural Science Foundation of China - LQ21E080005National Natural Science Foundation of China - 61701069 and 61971248Major Science and Technology Special Project in Jiangbei District, Ningbo City - 201901A0

Well-balanced scheme for modeling open-channel and surcharged flows in steep-slope closed conduit systems

The model presented herein is the same as that of Leon et al. (2010b), except that it has been modified to preserve "lake at rest" conditions in sloped prismatic conduits. The results of the new model (present paper) are identical to those of Leon et al. (2010b) for non-rest conditions. These schemes are based on the two-governing equation model, where open channel flows are simulated using the Saint-Venant equations and pressurized flows using the compressible water hammer equations. The new model preserves "lake at rest" conditions (horizontal still water) regardless of the conduit slope, resolves moving jump discontinuities over dry-beds in sloped conduits, and resolves small perturbations from steady-states, even when adjacent to dry regions. The preserving steady-state capability of the new model is of particular importance in continuous long simulations when the conduits are relatively steep (|S₀|>∼0.5%). Two main contributions are presented here, namely: (1) a new method for water stage reconstruction that preserves "lake at rest" conditions regardless of the pipe slope, and (2) a horizontal system of coordinates, instead of the commonly used inclined coordinate system, is used for facilitating the implementation of the proposed well-balanced scheme to complex systems. In the horizontal coordinate system, the cross-section of a circular pipe becomes an ellipse. The hydraulic characteristics of an ellipse are presented. Good results are achieved in the test cases.Keywords: Transient flow, Unsteady flow, Surcharged flow, Well-balanced scheme, Open-channel flow, Storm water system, Finite-volume method, Combined sewer syste

Using A Concurrent Hybrid Method To Optimize Short-Term Operation Of A Multi-Reservoir System With Multiple Objectives

Combining local search method with evolutionary-based algorithm has been introduced recently to improve performance of optimization on complex multi-objective problems (MOPs). Evolutionary algorithms (EAs) are attractive alternatives for solving the MOPs due to its global scope and independence of problem representation. However, it has been criticized for its relative slow convergence. Studies showed using local search method (LSM) can help to enhance convergence speed of the EA. Incorporating the LSM into the EA can mainly follow two ways: serial and concurrent. Serial approach applied the LSM after complement of the EA by predefining a switching time [1, 2]. The approach guarantees a local optimum with improved speed of convergence. Nevertheless, it is difficult to fix a priori switch timing on most of practical problems. Recent studies reported a concurrent approach that embedding the LSM within the EA optimizer [3, 4]. Some or all of the intermediate solutions from the EA can be modified by the LSM during the process. The LSM is treated as another operator in the EA thus to avoid the problem switch timing

Dimension reduction of decision variables for multireservoir operation: A spectral optimization model

Optimizing the operation of a multireservoir system is challenging due to the high dimension of the decision variables that lead to a large and complex search space. A spectral optimization model (SOM), which transforms the decision variables from time domain to frequency domain, is proposed to reduce the dimensionality. The SOM couples a spectral dimensionality-reduction method called Karhunen-Loeve (KL) expansion within the routine of Nondominated Sorting Genetic Algorithm (NSGA-II). The KL expansion is used to represent the decision variables as a series of terms that are deterministic orthogonal functions with undetermined coefficients. The KL expansion can be truncated into fewer significant terms, and consequently, fewer coefficients by a predetermined number. During optimization, operators of the NSGA-II (e.g., crossover) are conducted only on the coefficients of the KL expansion rather than the large number of decision variables, significantly reducing the search space. The SOM is applied to the short-term operation of a 10-reservoir system in the Columbia River of the United States. Two scenarios are considered herein, the first with 140 decision variables and the second with 3360 decision variables. The hypervolume index is used to evaluate the optimization performance in terms of convergence and diversity. The evaluation of optimization performance is conducted for both conventional optimization model (i.e., NSGA-II without KL) and the SOM with different number of KL terms. The results show that the number of decision variables can be greatly reduced in the SOM to achieve a similar or better performance compared to the conventional optimization model. For the scenario with 140 decision variables, the optimal performance of the SOM model is found with six KL terms. For the scenario with 3360 decision variables, the optimal performance of the SOM model is obtained with 11 KL terms

Fast approach for unsteady flow routing in complex river networks based on performance graphs

We present a new model for unsteady flow routing through dendritic and looped river networks based on performance graphs. The model builds upon the application of Hydraulic Performance Graph (HPG) to unsteady flow routing introduced by Gonzalez-Castro (2000) and adopts the Volume Performance Graph (VPG) introduced by Hoy and Schmidt (2006). The HPG of a channel reach graphically summarizes the dynamic relation between the flow through and the stages at the ends of the reach under gradually varied flow (GVF) conditions, while the VPG summarizes the corresponding storage. Both, the HPG and VPG are unique to a channel reach with a given geometry and roughness, and can be computed decoupled from unsteady boundary conditions by solving the GVF equation for all feasible conditions in the reach. Hence, in the proposed approach, the performance graphs can be used for different boundary conditions without the need to recompute them. Previous models based on the performance graph concept were formulated for routing through single channels or channels in series. The new approach expands on the use of HPG/VPGs and adds the use of rating performance graphs for unsteady flow routing in dentritic and looped networks. We exemplify the applicability of the proposed model to subcritical unsteady flow routing through a looped network and contrast its simulation results with those from the well-known unsteady HEC-RAS model. Our results show that the present extension of application of the HPG/VPGs appears to inherit the robustness of the HPG routing approach in Gonzalez-Castro (2000). The unsteady flow model based on performance graphs presented here can be extended to include supercritical flows.Keywords: Looped network, Hydraulic routing, Modeling, Simulation, Unsteady flow, Dendritic network, River hydraulics, Flooding, Flow routingKeywords: Looped network, Hydraulic routing, Modeling, Simulation, Unsteady flow, Dendritic network, River hydraulics, Flooding, Flow routin

The intertidal hydraulics of tide-dominated reef platforms

A 2 week field experiment investigated the hydrodynamics of a strongly tidally forced tropical intertidal reef platform in the Kimberley region of northwestern Australia, where the spring tidal range exceeds 8 m. At this site, the flat and wide (∼1.4 km) reef platform is located slightly above mean sea level, such that during low tide the offshore water level can fall 4 m below the platform. While the reef always remained submerged over each tidal cycle, there were dramatic asymmetries in both the water levels and velocities on the reef, i.e., the flood duration lasted only ∼2 h versus ∼10 h for the ebb. These dynamics were investigated using a one-dimensional numerical model (SWASH) to solve the nonlinear shallow water equations with rapid (sub to supercritical) flow transitions. The numerical model revealed that as water drains off the reef, a critical flow point was established near the reef edge prior to the water discharging down the steep forereef. Despite this hydraulic control, bottom friction on the reef was still found to make a far greater contribution to elevating water levels on the reef platform and keeping it submerged over each tidal cycle. Finally, a simple analytical model more broadly shows how water levels on intertidal reef platforms functionally depend on properties of reef morphology, bottom roughness, and tidal conditions, revealing a set of parameters (a reef draining time-scale and friction parameter) that can be used to quantify how the water depth will fall on a reef during ebb tide.This is the publisher’s final pdf. The article is copyrighted by American Geophysical Union and published by John Wiley & Sons, Inc.. It can be found at: http://agupubs.onlinelibrary.wiley.com/agu/jgr/journal/10.1002/%28ISSN%292169-9291

Integration of advanced methods and models to study drug absorption and related processes : An UNGAP perspective

Funding Information: AI acknowledges the support of projects icp009 (ALKOOL) of PRACE-ICEI (grant agreement 800858) for awarding access to Piz Daint, at the Swiss National Supercomputing Centre (CSCS), Switzerland and BG05M2OP001–1.001–0004 (UNITe) of the Bulgarian Ministry of Education and Science. For further details on points raised in this article, please contact [email protected]. Funding Information: Acknowledgements. JAGH is supported by the Biocenter Finland, the Helsinki Institute of Life Sciences, and the Faculty of Pharmacy, University of Helsinki. Publisher Copyright: © 2021 The AuthorsThis collection of contributions from the European Network on Understanding Gastrointestinal Absorption-related Processes (UNGAP) community assembly aims to provide information on some of the current and newer methods employed to study the behaviour of medicines. It is the product of interactions in the immediate pre-Covid period when UNGAP members were able to meet and set up workshops and to discuss progress across the disciplines. UNGAP activities are divided into work packages that cover special treatment populations, absorption processes in different regions of the gut, the development of advanced formulations and the integration of food and pharmaceutical scientists in the food-drug interface. This involves both new and established technical approaches in which we have attempted to define best practice and highlight areas where further research is needed. Over the last months we have been able to reflect on some of the key innovative approaches which we were tasked with mapping, including theoretical, in silico, in vitro, in vivo and ex vivo, preclinical and clinical approaches. This is the product of some of us in a snapshot of where UNGAP has travelled and what aspects of innovative technologies are important. It is not a comprehensive review of all methods used in research to study drug dissolution and absorption, but provides an ample panorama of current and advanced methods generally and potentially useful in this area. This collection starts from a consideration of advances in a priori approaches: an understanding of the molecular properties of the compound to predict biological characteristics relevant to absorption. The next four sections discuss a major activity in the UNGAP initiative, the pursuit of more representative conditions to study lumenal dissolution of drug formulations developed independently by academic teams. They are important because they illustrate examples of in vitro simulation systems that have begun to provide a useful understanding of formulation behaviour in the upper GI tract for industry. The Leuven team highlights the importance of the physiology of the digestive tract, as they describe the relevance of gastric and intestinal fluids on the behaviour of drugs along the tract. This provides the introduction to microdosing as an early tool to study drug disposition. Microdosing in oncology is starting to use gamma-emitting tracers, which provides a link through SPECT to the next section on nuclear medicine. The last two papers link the modelling approaches used by the pharmaceutical industry, in silico to Pop-PK linking to Darwich and Aarons, who provide discussion on pharmacometric modelling, completing the loop of molecule to man.Peer reviewe

The role of maternal age & birth order on the development of unilateral and bilateral retinoblastoma: a multicentre study

BACKGROUND/OBJECTIVES: Retinoblastoma is a common childhood intraocular malignancy, the bilateral form of which most commonly results from a de novo germline pathogenic variant in the RB1 gene. Both advanced maternal age and decreasing birth order are known to increase the risk of de novo germline pathogenic variants, while the influence of national wealth is understudied. This cohort study aimed to retrospectively observe whether these factors influence the ratio of bilateral retinoblastoma cases compared to unilateral retinoblastoma, thereby inferring an influence on the development of de novo germline pathogenic variants in RB1. SUBJECTS/METHODS: Data from 688 patients from 11 centres in 10 countries were analysed using a series of statistical methods. RESULTS: No associations were found between advanced maternal age, birth order or GDP per capita and the ratio of bilateral to unilateral retinoblastoma cases (p values = 0.534, 0.201, 0.067, respectively), indicating that these factors do not contribute to the development of a de novo pathogenic variant. CONCLUSIONS: Despite a lack of a definitive control group and genetic testing, this study demonstrates that advanced maternal age, birth order or GDP per capita do not influence the risk of developing a bilateral retinoblastoma