Optimizing Safe Yield Policy Implementation

The presented method enhances groundwater-mandated safe yield management. It is useful for settings that prevent sustained yield or integrated management. To protect hydraulically connected surface water rights, the Utah government’s Cache Valley groundwater management plan proposes that total pumping increase not exceed 84,431 m³/day. To determine how best to spatially distribute additional allowable pumping, stakeholders quantified limits defining acceptable impacts on selected water resource indicators. A new simulation–optimization (S–O) algorithm used these limits while computing optimal spatially distributed perennial yield or safe yield groundwater pumping extraction strategies. The limits prevent unacceptable decreases in: head and net flow between aquifer and surface waters (rivers, surface/subsurface drains, springs, lakes). The optimization objective function maximizes weighted pumping to provide water for 18 growing municipalities. For 16 perennial yield scenarios, computed optimal pumping increases differ in protectiveness toward senior water rights, and range from 16% to 103% of the state plan-proposed increase. Implementing a protective strategy would achieve 90% of the storage changes needed to reach equilibrium within 23 years. Indicator potentiometric heads would reach equilibrium within 10–40 years. At equilibrium, an optimal Cache Valley perennial yield strategy acceptably minimizes net annual non-pumping discharges. By comparison, multi-period 20-year transient groundwater mining optimizations allow more pumping in early years. Pumping then must decline to satisfy seepage and head constraints through year 20. Adverse seepage impact would increase for years thereafter. For situations governed by safe or perennial yield policy, equilibrium-based (steady-state) optimization is very useful. It effectively develops optimal perennial yield strategies.     

Multi-objective optimization in wire-electro-discharge machining of TiC reinforced composite through Neuro-Genetic technique

This paper proposed a Neuro-Genetic technique to optimize the multi-response of wire electro-discharge machining (WEDM) process. The technique was developed through hybridization of a radial basis function network (RBFN) and non-dominated sorting genetic algorithm (NSGA-II). The machining was done on 5 vol% titanium carbide (TiC) reinforced austenitic manganese steel metal matrix composite (MMC). The proposed Neuro-Genetic technique was found to be potential in finding several optimal input machining conditions which can satisfy wide requirements of a process engineer and help in efficient utilization of WEDM in industry.     

Critical Density for Coverage and Connectivity in Three-Dimensional Wireless Sensor Networks Using Continuum Percolation

Although most of the studies on coverage and connectivity in wireless sensor networks (WSNs) considered two-dimensional (2D) settings, such networks can in reality be accurately modeled in a three-dimensional (3D) space. The concepts of continuum percolation theory best fit the problem of connectivity in WSNs to find out whether the network provides long-distance multihop communication. In this paper, we focus on percolation in coverage and connectivity in 3D WSNs. We say that the network exhibits a coverage percolation (respectively, connectivity percolation) when a giant covered region (respectively, giant connected component) almost surely spans the entire network for the first time. Because of the dependency between coverage and connectivity, the problem is not only a continuum percolation problem but also an integrated continuum percolation problem. Thus, we propose an integrated-concentric-sphere model to address coverage and connectivity in 3D WSNs in an integrated way. First, we compute the critical density lambda_C ^con above which coverage percolation in 3D WSNs will almost surely occur. Second, we compute the critical density lambda_c ^con above which connectivity percolation in 3D WSNs will almost surely occur. Third, we compute the critical density lambda_c ^cov-con above which both coverage and connectivity percolation in 3D WSNs will almost surely occur. For each of these three problems, we also compute their corresponding critical network degree. Our results can be helpful in the design of energy-efficient topology control protocols for 3D WSNs in terms of coverage and connectivity.     

An electromyographic investigation of asymmetric lifting and moving of a load: III. Models for determining muscle activity based on anthropometric characteristics

Regression models for six muscles, the left and right iliocostalis, the left and right erector spinae, and the left and right external oblique, were developed for asymmetry and height effects for floor and knuckle lifts. The models were based on participant anthropometric and other measures. Stepwise regression was performed for developing the prediction models. The models developed were discrete in terms of specific height and asymmetry. © 2009 Wiley Periodicals, Inc.     

Developmental stages in experimental liver metastases: relation to invasiveness

We have previously reported that an invasive morphotype can be evoked in a rat colon carcinoma by transplanting it into pre-induced subcutaneous granulation tissue. We have now studied the interaction of the same tumor with liver tissue, which is extremely poor in connective tissue in comparison with the subcutaneous site. Tumor cells were injected into the portal system and the resulting experimental liver metastases were examined by electron microscopy and immunohistochemistry. Early metastases consisted of well-differentiated acini, fully surrounded by connective tissue that was derived from the periportal stroma. In a later stage, this connective tissue was overgrown by tumor cells and, almost immediately, acinar differentiation was lost. Most metastases eventually reached the liver capsule, which reacted by forming a layer of granulation tissue. Only in this layer, we observed invasion by thin tumor cell strands, which were often intimately associated with fibroblasts or with blood capillaries. The tumor cells remained smooth and rounded during this process. After fully penetrating the granulation tissue, the tumor cell strands reached the liver surface, where they formed poorly structured papillary masses that were nearly devoid of stroma. Our observations indicate that, even in a relatively homogeneous organ like the liver, the tumor-host interaction is highly complex and dynamic. They also confirm the notion that granulation tissue stimulates tumor invasiveness. Finally, they show that tumor cells can actively invade host tissues without exhibiting a "fibroblastic" morphology.     

Progress on the boundary element method to study the disturbance fields of bodies moving in an unbounded medium

For studying flow problems involved with complex physics it is now common to use numerical field methods for solving Navier-Stokes or Euler equations. However, for a large class of fluid mechanics problems, which can be dealt with linearized potential equations, the boundary element method proves to be quite useful, especially for its easy application and relatively less computational effort compared to the field methods. The boundary element method has undergone some significant advancements in the last decade with respect to the study of steady and unsteady flow problems concerning wing aerodynamics in compressible medium, flow fields of propellers and rotors and acoustical disturbance propagation from moving bodies. In this paper a few recent contributions which evolved in the DLR as research projects and as doctoral and diploma thesis of the Technical University Braunschweig are concisely described.List of symbols a Sound velocity - b Span of a wing - c _p Coefficient of static pressure - c _dp Coefficient of profile drag - c ₁, c _d, c_m Coefficient of lift, drag and moment per unit span width - c _L, c_D, c_M Total lift, drag and moment-coefficients - c _T, c_P Thrust and power-coefficient of a propeller - d Distance - D Doublet strength - e Specific heat energy - E Total energy in a moving medium element - f Frequency - F Field point - g Gravitational acceleration - h Radial distance in cylinder coordinates - I ₁, I ₂ Inducing functions - i, j, k Unit vectors in cartesian coordinates - k Wave number [/a ] - l Local wing-chord - l ₀, l _v Length of singularity element at t _oand t _v - m Notation for Fourier-component - M, M ^* Mach number based on local and critical sound speed - n Number of rotation per second - n Unit normal vector to a surface     

Sliding mode controller design via delay-dependent H∞ stabilization criterion for load frequency regulation

This work presents a control approach based on sliding-mode-control (SMC) to design robust H∞ state feedback controllers for load frequency regulation of delayed interconnected power system (IPS) with parametric uncertainties. Considering both state feedback control strategy and delayed feedback control strategy, two SMC laws are proposed. The proposed control laws are designed to improve the stability and disturbance rejection performance of delayed IPS, while stabilization criteria in the form of linear matrix inequality are derived by choosing a Lyapunov–Krasovskii functional. An artifcial time-delay is incorporated in the control law design of the delayed feedback control structure to enhance the controller performance. A numerical example is considered to study the control performance of the proposed controllers and simulation results are provided to observe the dynamic response of the IPS.     

A performance evaluation framework of public health distribution network for essential medicines: lessons from the select Indian states

The present work has been carried out to develop a performance evaluation framework of distribution network design in public health with specific reference to essential medicines based on six different types of public health distribution networks (PHDNs) prevalent across six Indian states. We evaluated the performance of PHDNs on the criteria of cost and service and also on the sub-criteria of cost and service by following the analytic hierarchy process. We utilized the pairwise comparison method in determining the relative importance of criteria and sub-criteria by seeking responses from several experts and subsequently evaluated the PHDNs on all sub-criteria in a 7-point Likert scale by seeking views from the same experts. Finally, we developed the “cost–service matrix,” in which cost and service have been depicted in the horizontal and vertical axes, respectively. We demonstrated the performance of six PHDNs in this matrix in terms of cost and service by plotting scores obtained by them on cost and service, respectively. The findings of the study provide rich insights to the policy planners of public health.     

A matching game framework for users clustering and resource allocation with wireless power transfer in a CR-NOMA network

This paper investigates the resource allocation in a massively deployed user cognitive radio enabled non-orthogonal multiple access (CR-NOMA) network considering the downlink scenario. The system performance deteriorates with the number of users who are experiencing similar channel characteristics from the base station (BS) in NOMA. To address this challenge, we propose a framework for maximizing the system throughput that is based on one-to-one matching game theory integrated with the machine learning technique. The proposed approach is decomposed to solve users clustering and power allocation subproblems. The selection of optimal cluster heads (CHs) and their associated cluster members is based on Gale-Shapley matching game theoretical model with the application of Hungarian method. The CHs can harvest energy from the BS and transfer their surplus power to the primary user (PU) through wireless power transfer. In return, they are allowed to access the licensed band for secondary transmission. The power allocation to the users intended for power conservation at CHs is formulated as a probabilistic constraint, which is then solved by employing the support vector machine (SVM) algorithm. The simulation results demonstrate the efficacy of our proposed schemes that enable the CHs to transfer the residual power while ensuring maximum system throughput. The effects of different parameters on the performance are also studied.