Allocation Options Research Articles

Variable Sets and Fuzzy Rating Interval for Water Allocation Options Assessment

Optimal water allocation is an important means of improving water use efficiency. However, since water allocation options are usually characterized by multi-region, multi-principle and multi-criterion factors, decision-makers often have difficulty in making objective decisions using them because the many available water allocation options often make the ratings of the options so close to be ranked. This study present a hierarchy variable sets (VS) model, based on the single-layer variable sets model, for ranking the water allocation options of Jining City, China. The ratings of the options are evaluated using a fuzzy rating interval (FRI) that can overcome homogenization in the ratings. The structure of the model presented in this study is clear with a simple procedure of computation and the result is rational. The case study used illustrates that this model can help decision-makers know the rating of water allocation options partially and overall. The computed result from this model appears more convincing than a previous water allocation approach for the city based on the maximum entropy principle.

A mathematical technique for hybrid power system design with energy loss considerations

This paper presents a generic mathematical optimisation model for the design of hybrid power systems (HPSs). The model takes into account power losses during the allocation of power generated from renewables to appliance loads, and is formulated as a linear programme (LP) based on a superstructure including all possible power allocation options in a typical HPS. With given power source and demand data for an HPS, the minimum outsourced electricity supply and the minimum electricity storage capacity required can be determined through a two-step optimisation. Three literature case studies are solved to illustrate the proposed approach.

Assessing the impact of training sample selection on accuracy of an urban classification: a case study in Denver, Colorado

Understanding the factors that influence the performance of classifications over urban areas is of considerable importance to applications of remote-sensing-derived products in urban design and planning. We examined the impact of training sample selection on a binary classification of urban and nonurban for the Denver, Colorado, metropolitan area. Complete coverage reference data for urban and nonurban cover were available for the year 1997, which allowed us to examine variability in accuracy of the classification over multiple repetitions of the training sample selection and classification process. Four sampling designs for selecting training data were evaluated. These designs represented two options for stratification (spatial and class-specific) and two options for sample allocation (proportional to area and equal allocation). The binary urban and nonurban classification was obtained by employing a decision tree classifier with Landsat imagery. The decision tree classifier was applied to 1000 training samples selected by each of the four training data sampling designs, and accuracy for each classification was derived using the complete coverage reference data. The allocation of sample size to the two classes had a greater effect on classifier performance than the spatial distribution of the training data. The choice of proportional or equal allocation depends on which accuracy objectives have higher priority for a given application. For example, proportionally allocating the training sample to urban and nonurban classes favoured user’s accuracy of urban whereas equally allocating the training sample to the two classes favoured producer’s accuracy of urban. Although this study focused on urban and nonurban classes, the results and conclusions likely generalize to any binary classification in which the two classes represent disproportionate areas.

Bandwidth Reservation as a Coexistence Strategy in Opportunistic Spectrum Access Environments

We consider a scenario in which a licensed wireless operator or primary network (PN) coexists with an ad-hoc, cognitive, secondary network. To minimize harmful interference on the primary users (PUs), secondary users (SUs) sense the PU activity on the licensed spectrum band before transmitting in spectrum opportunities. We study a bandwidth reservation (BR) scheme by which the PN keeps a set of adjacent channels free of PU transmissions. These reserved channels only accommodate PU traffic when all the non-reserved channels are used, and the SUs only occupy available channels within the reserved spectrum. Intuitively, this strategy reduces collision probability and simplifies the design of opportunistic spectrum access (OSA) mechanisms. However, from the point of view of the PN, BR entails a tradeoff between the benefits of an improved coexistence with SUs, and the capacity reduction associated to having fewer options for PU channel allocation. The main objective of this paper is to determine when BR improves the overall PN performance under SU activity. The SUs are characterized by a hardware limited radio, imperfect spectrum sensing, bayesian estimation of PU activity and multichannel access. Because PU capacity is the central issue, we assume a PN capable of exploiting all the available bandwidth at every moment. By means of a Markov-reward model, we compute the expected PU capacity with and without BR, considering propagation effects, interference and random locations. The results show that, in a non-congested PN with SU activity, the interference reduction capability of BR increases the overall capacity of the PN compared to not using BR.

A Comparative Study of Flexibility in Water Allocation in the Context of Hydrologic Variability

River flow that is characterized by variability requires commensurate flexibility in allocating water so that water users are able to plan their activities and respond accordingly. An indicator-based assessment method is proposed in this study to evaluate the flexibility of water allocation, based on a concept that a flexible water allocation regime provides greater opportunity for users to freely decide individual water use and leads to more variability and diversity for water consumption among the users. This is demonstrated by using historical water-use data and applying the assessment method in three river basins with different water allocation regimes. These allocation regimes include the seasonal and volumetric water allocation system in the Yellow River of China, duration-based water allocation in Northwestern China, and capacity sharing in southern Queensland in the northern Murray Darling Basin of Australia. Historical water-use variability and diversity are defined and assessed. The result shows that water allocation flexibility varies across the different water entitlement regimes. Duration-based water allocation, a type of allocation that provides the highest degree of water-use autonomy, is ranked as the most flexible regime. Seasonal water allocation, which has the highest level of centralized regulation, shows the lowest flexibility. The proposed indicator based assessment method would be useful for evaluating the flexibility of policy options for water allocation. This could be helpful for improving the capability of water allocation regimes to cope with the changing environment and improving the effectiveness of water allocation systems.

Rewards, costs and flexibility in dynamic resource allocation

Various canonical forms of general resource allocation problemsarise naturally across a broad spectrum of computer systems andcommunication networks. As the complexities of these systemsand networks continue to grow, together with ubiquitous advancesin technology, new approaches and methods are required to effec-tively and efficiently solve these problems. Such environments of-ten consist of different types of resources that are allocated in com-bination to serve demand whose behavior over time is characterizedby different types of uncertainty and variability. Each type of re-source has a different reward and cost structure that ranges from thebest of a set of primary resource allocation options, having the high-est reward, highest cost and highest net-benefit, to a secondary re-source allocation option, having the lowest reward, lowest cost andlowest net-benefit. Each type of resource also has different struc-tures for the flexibility and cost of making changes to the allocationcapacity. The resource management optimization problem we con-sider consists of adaptively determining the primary and secondaryresource allocation capacities that serve the uncertain demand andthat maximize the expected net-benefit over a time horizon of in-terest based on the foregoing reward, cost and flexibility structuralproperties of the different types of resources.The general class of resource allocation problems studied in thispaper arises in a wide variety of application domains such as cloudcomputing and data center environments, computer and communi-cation networks, and energy-aware and smart power grid environ-ments, among many others. Across these and many other domain-specific resource allocation problems, there is a common need forthe dynamic adjustment of allocations among multiple types of re-sources, each with different structural properties, to satisfy time-varying and uncertain demand. Taking a financial mathematicsapproach that hedges against future risks associated with resourceallocation decisions and uncertain demand, we consider the under-lying fundamental stochastic optimal control problem where thedynamic control policy that allocates primary resource capacitiesto serve uncertain demand is a variational stochastic process withconditions on its derivative, which in turn determines the secondaryresource allocation capacity. The objective is to maximize the ex-pected discounted net-benefit over time based on the structural prop-

Network Routing of Snowplow Trucks with Resource Replenishment and Plowing Priorities

The routing of snowplow trucks in urban and regional areas encompasses a variety of complex decisions, especially for jurisdictions with heavy snowfall. The main activities involve dispatching a fleet of snowplow trucks from a central depot or satellite facility to clean and spread salt and chemicals on the network links (i.e., snow routes). In this paper, a mixed integer linear program model is proposed to minimize the total operation time of all snowplow trucks needed to complete a given set of snow routes with multiple plowing priorities and to reduce the longest individual truck operation time. Customized construction and local search solution algorithms are developed and used to design snow routes for an empirical application. The computational results show that the proposed solution approach is able to solve the problem effectively and the model result outperforms the current solution in practice. The proposed models and algorithms are also incorporated into the development of a state-of-the-art snowplow routing software that can help planners optimize snow routes and evaluate options for resource allocation.

An optimization model for water resources allocation risk analysis under uncertainty

In order to deal with the risk of low system stability and unbalanced allocation during water resources management under uncertainties, a risk-averse inexact two-stage stochastic programming model is developed for supporting regional water resources management. Methods of interval-parameter programming and conditional value-at-risk model are introduced into a two-stage stochastic programming framework, thus the developed model can tackle uncertainties described in terms of interval values and probability distributions. In addition, the risk-aversion method was incorporated into the objective function of the water allocation model to reflect the preference of decision makers, such that the trade-off between system economy and extreme expected loss under different water inflows could be analyzed. The proposed model was applied to handle a water resources allocation problem. Several scenarios corresponding to different river inflows and risk levels were examined. The results demonstrated that the model could effectively communicate the interval-format and random uncertainties, and risk aversion into optimization process, and generate inexact solutions that contain a spectrum of water resources allocation options. They could be helpful for seeking cost-effective management strategies under uncertainties. Moreover, it could reflect the decision maker's attitude toward risk aversion, and generate potential options for decision analysis in different system-reliability levels.

A critical comparison of ten disposable cup LCAs

Disposable cups can be made from conventional petro-plastics, bioplastics, or paperboard (coated with petro-plastics or bioplastics). This study compared ten life cycle assessment (LCA) studies of disposable cups with the aim to evaluate the robustness of their results. The selected studies have only one impact category in common, namely climate change with global warming potential (GWP) as its category indicator. Quantitative GWP results of the studies were closer examined. GWPs within and across each study show none of the cup materials to be consistently better than the others. Comparison of the absolute GWPs (after correction for the cup volume) also shows no consistent better or worse cup material. An evaluation of the methodological choices and the data sets used in the studies revealed their influence on the GWP. The differences in GWP can be attributed to a multitude of factors, i.e., cup material and weight, production processes, waste processes, allocation options, and data used. These factors basically represent different types of uncertainty. Sensitivity and scenario analyses provided only the influence of one factor at once. A systematic and simultaneous use of sensitivity and scenario analyses could, in a next research, result in more robust outcomes.

Collision-Aware Routing and Spectrum Assignment in GMPLS-Enabled Flexible-Bandwidth Optical Network

In a flexible-bandwidth optical network (FBON) with a generalized multiprotocol label switching control plane, the resource reservation protocol with traffic engineering extensions (RSVP-TE) is employed to establish end-to-end bandwidth variable lightpaths. The resource reservation can be blocked due to spectrum contention of different concurrent RSVP instances (called backward blocking), and it is the predominant blocking contribution when traffic load is low and arrival highly dynamic. Also, due to its flexible traffic granularity in FBON, the backward collision would happen more frequently and the collision scenario would be more complicated than that in wavelength-routed networking; thus the need for a collision evaluation and avoiding method. So, a collision-avoiding routing with maximum available spectrum allocation (SA) options and an SA scheme to search the spectrum segment with minimum collision possibility are proposed for backward blocking reduction, as well as an extension to the RSVP-TE. Simulation results show that the proposed algorithm could achieve better blocking performance through significantly reducing the backward reservation collision but with acceptable forward blocking deterioration. At the same time, with the proposed algorithm, different granularity traffic could be served more fairly in FBON.

UNCERTAINTY AND THE DECISION MAKER: ASSESSING AND MANAGING THE RISK OF UNDESIRABLE OUTCOMES

We present an approach to rank order new programs in ways that accommodate uncertainty of different outcomes occurring, on the basis of the size and nature ('bad' or 'good') of those outcomes. This represents an improvement on the way uncertainty has been accommodated in existing approaches (e.g., threshold approach to cost-effectiveness analysis). We illustrate the approach using the decision making plane, which explicitly incorporates opportunity costs and relaxes the assumptions of perfect divisibility and constant returns to scale of the cost-effectiveness plane. The nature of the bad (or good) outcome is determined by the quadrant that it falls into (i.e., a 'quadrant effect') and its magnitude by its location within the quadrant (i.e., 'within quadrant effect'). By explicitly defining the loss function, the process of accepting (or rejecting) a new program becomes transparent. We illustrate the approach using a loss function and a net gain function. We show that by recognizing that, not all bad (or good) outcomes are equal and the choice of a loss or a net gain function can result in different ranking of resource allocation options. Further implications of the proposed approach are discussed.

Young children are more generous when others are aware of their actions.

Adults frequently employ reputation-enhancing strategies when engaging in prosocial acts, behaving more generously when their actions are likely to be witnessed by others and even more so when the extent of their generosity is made public. This study examined the developmental origins of sensitivity to cues associated with reputationally motivated prosociality by presenting five-year-olds with the option to provide one or four stickers to a familiar peer recipient at no cost to themselves. We systematically manipulated the recipient’s knowledge of the actor’s choices in two different ways: (1) occluding the recipient’s view of both the actor and the allocation options and (2) presenting allocations in opaque containers whose contents were visible only to the actor. Children were consistently generous only when the recipient was fully aware of the donation options; in all cases in which the recipient was not aware of the donation options, children were strikingly ungenerous. These results demonstrate that five-year-olds exhibit “strategic prosociality,” behaving differentially generous as a function of the amount of information available to the recipient about their actions. These findings suggest that long before they develop a rich understanding of the social significance of reputation or are conscious of complex strategic reasoning, children behave more generously when the details of their prosocial actions are available to others.

Science-Policy Dialogues for Water Security: Addressing Vulnerability and Adaptation to Global Change in the Arid Americas

www.EnvironmEntmagazinE.org voLUmE 54 nUmBEr 3 Climate change and watersupply uncertainty coupled with mounting human demands for water are straining the availability and quality of freshwater in much of the world. These twin forces cause a palpable rise in societal vulnerability, here considered as susceptibility to adverse effects of global environmental change.1 The vulnerability of water supplies (or, water vulnerability) places human communities at risk for exposure,2 or change,3 and thereby creates huge adaptation challenges. The actions being taken to reduce risks and capitalize on opportunities are considered adaptation or adaptive strategies.4 The most sensitive and vulnerable communities are those that face the greatest exposure and are most limited in their capacity to adapt. Rapidly growing and ever wealthier urban populations, expanding agribusinesses, diverse industries, extensive mining, power generation, and tourism often deprive water from or degrade its quality for use by marginalized populations of smallholder farmers and the urban poor, as well as for ecosystems along streams, lakes, and coasts recognized as biodiversity hotspots in the arid landscape. The arid5 Americas—as characterized by the southwestern United States, northwestern Mexico, north-central Chile and Argentina, and northeastern Brazil—manifest the just-described challenges especially well.6 This article focuses on two areas where our research team has been developing science-policy adaptation strategies: (1) the Sonora-Arizona drylands shared by Mexico and the United States (See map at right), and (2) the drylands east and west of the Central Andes in Chile and Argentina (see map, page 32). In these areas water remains acutely limited even as drought and flood extremes increase, ecosystems are under growing pressure, and economic globalization drives water demand. These global-change conditions threaten the security of access to water. Yet the foregoing conditions prevail—with little regard for constraints to supply, insufficient understanding of vulnerability, and inadequate attention to adaptive measures.7 To the extent that such problems are attributable to human agency,8 there is evidence that effective policies and actions can alleviate some of the harm.9 Our article describes two interactive Science-Policy Dialogues for Water Security:

Asset Allocation Options for Wealth Accumulation

What is the best asset allocation scheme for retirement investing and wealth accumulation? The authors examine seven schemes, including the “110 minus age” rule of thumb and strategies employed by popular retirement mutual funds. Historically, the 100% equity portfolio has offered the highest returns with little extra risk. However, if the authors lower equity premiums or bootstrap historical results, then retirement mutual funds and the “110 minus age“ rule of thumb perform somewhat better than 100% equity portfolios in adverse circumstances. But overall, a 100% equity portfolio provides the highest wealth accumulation.

Asset Allocation Options for Wealth Accumulation

Asset Allocation Options for Wealth Accumulation

A water balance modelling approach to optimising the use of water resources in ephemeral sand rivers

AbstractAlluvial aquifers present a possibility for conjunctive use with surface reservoirs for the storage of water in ephemeral sand rivers such as the Mzingwane River in the Limpopo Basin, Zimbabwe. The Lower Mzingwane valley is a semi‐arid region with high water stress, where livelihoods have revolved around the large rivers for thousands of years. However, current water allocation favours the commercial user: of the 2600 ha irrigated in the 5960 km2 (596 000 ha) region, only 410 ha are for smallholder farmers. A water balance approach was used to model the surface water resources and groundwater resources to determine the potential for expanding irrigation and to explore water allocation options. Using a combination of field and laboratory investigations, remote sensing and existing data, the Lower Mzingwane valley was modelled successfully using the spreadsheet‐based model WAFLEX, with a new module incorporated to compute the water balance of alluvial aquifer blocks.Results showed that the Lower Mzingwane alluvial aquifers can store 38 × 106 m3 of water, most of that storage being beyond the reach of evaporation. Current water usage can be more than tripled: the catchment could supply water for currently‐planned irrigation schemes (an additional 1250 ha), and the further irrigation of two strips of land along each bank of the Mzingwane River (an extra 3630 ha)—without construction of any new reservoirs. The system of irrigating strips of land along each bank of the Mzingwane River would be decentralized, farmer or family owned and operated and the benefits would have the potential to reach a much larger proportion of the population than is currently served. However, there could be substantial downstream impact, with around nearly one‐third of inflows not being released to the Limpopo River.The approach developed in this paper can be applied to evaluate the potential of alluvial aquifers, which are widespread in many parts of semi‐arid Africa, for providing distributed access to shallow groundwater in an efficient way. This can enhance local livelihoods and regional food security. Copyright © 2010 John Wiley & Sons, Ltd.

Study on the Concept of Per Capita Cumulative Emissions and Allocation Options

Global long-term emission reduction targets need well defined options for equitable allocation of greenhouse gas emissions. Scholars from developing countries put forward the concept of equitable per capita cumulative emission rights. There are four possible operational definitions resulting from this concept. These potential options for allocation of emission rights are expressed with mathematical equations. Through simple simulation, this paper reveals the advantages, disadvantages and characteristics of each option. CitationYu, S., X. Gao, C. Ma, et al., 2011: Study on the concept of per capita cumulative emissions and allocation options. Adv. Clim. Change Res., 2(2), doi: 10.3724/SP.J.1248.2011.00079.

A survey on 3GPP heterogeneous networks

As the spectral efficiency of a point-to-point link in cellular networks approaches its theoretical limits, with the forecasted explosion of data traffic, there is a need for an increase in the node density to further improve network capacity. However, in already dense deployments in today's networks, cell splitting gains can be severely limited by high inter-cell interference. Moreover, high capital expenditure cost associated with high power macro nodes further limits viability of such an approach. This article discusses the need for an alternative strategy, where low power nodes are overlaid within a macro network, creating what is referred to as a heterogeneous network. We survey current state of the art in heterogeneous deployments and focus on 3GPP LTE air interface to describe future trends. A high-level overview of the 3GPP LTE air interface, network nodes, and spectrum allocation options is provided, along with the enabling mechanisms for heterogeneous deployments. Interference management techniques that are critical for LTE heterogeneous deployments are discussed in greater detail. Cell range expansion, enabled through cell biasing and adaptive resource partitioning, is seen as an effective method to balance the load among the nodes in the network and improve overall trunking efficiency. An interference cancellation receiver plays a crucial role in ensuring acquisition of weak cells and reliability of control and data reception in the presence of legacy signals.

Accounting for carbon dioxide emissions from international shipping: Burden sharing under different UNFCCC allocation options and regime scenarios

CO 2 emissions from international shipping, which are currently unregulated, are predicted to rise dramatically if no regulations are implemented. International bunker fuel emissions have been excluded from the Kyoto Protocol ; the UNFCCC conference in Copenhagen also failed to bring about clear directions on how to proceed with these emissions. In this paper, the various options suggested by the Subsidiary Body for Scientific and Technological Advice of the UNFCCC for allocating CO 2 emissions from international shipping to individual countries are investigated. This is followed by a discussion of the economic and regulatory issues related to these options and the consequences of applying them. Then, the various options are evaluated on the basis of environmental effectiveness, possibility of legal implementation, and fairness of burden sharing. The evaluation shows that there is no single allocation option that can be regarded as environmentally effective, legally effective and allowing for fair burden sharing. Nevertheless, it is concluded that an allocation of international shipping emissions should be conducted on the basis of the operating company.

Risk‐based multiobjective resource allocation in hierarchical systems with multiple decisionmakers. Part I: Theory and methodology

AbstractThis paper sets forth a resource allocation process for mitigating the risks that natural disasters, accidents, or willful attacks pose to large‐scale hierarchical systems. Such systems are typically comprised of plural decisionmakers at each organizational level, each with multiple risk management objectives. In this paper, we propose a Multiobjective Multi‐Decisionmaker Resource Allocation (MOMDRA) framework to model this process; we also offer a discussion of risk modeling methods under the MOMDRA framework. Furthermore, using a Hierarchical Multiobjective (HMO) approach, this paper derives strategies for generating Pareto optimal resource allocation options for different cases of decisionmakers. An illustrative example demonstrates the effectiveness of the MOMDRA framework in risk‐based modeling and decisionmaking within large‐scale hierarchical systems. © 2010 Wiley Periodicals, Inc. Syst Eng 14: 1–16, 2011