Optimal resource allocation in random networks with transportation bandwidths
Yeung, C. H.; Wong, K. Y. Michael
2009-03-01
We apply statistical physics to study the task of resource allocation in random sparse networks with limited bandwidths for the transportation of resources along the links. Recursive relations from the Bethe approximation are converted into useful algorithms. Bottlenecks emerge when the bandwidths are small, causing an increase in the fraction of idle links. For a given total bandwidth per node, the efficiency of allocation increases with the network connectivity. In the high connectivity limit, we find a phase transition at a critical bandwidth, above which clusters of balanced nodes appear, characterized by a profile of homogenized resource allocation similar to the Maxwell construction.
Directory of Open Access Journals (Sweden)
Heng Wang
2014-01-01
Full Text Available Multi-spot-beam technique has been widely applied in modern satellite communication systems. However, the satellite power and bandwidth resources in a multi-spot-beam satellite communication system are scarce and expensive; it is urgent to utilize the resources efficiently. To this end, dynamically allocating the power and bandwidth is an available way. This paper initially formulates the problem of resource joint allocation as a convex optimization problem, taking into account a compromise between the maximum total system capacity and the fairness among the spot beams. A joint bandwidth and power allocation iterative algorithm based on duality theory is then proposed to obtain the optimal solution of this optimization problem. Compared with the existing separate bandwidth or power optimal allocation algorithms, it is shown that the joint allocation algorithm improves both the total system capacity and the fairness among spot beams. Moreover, it is easy to be implemented in practice, as the computational complexity of the proposed algorithm is linear with the number of spot beams.
Islam, Muhammad Nazmul; Kompella, Sastry
2011-01-01
In this paper, we investigate joint optimal relay selection and resource allocation that are fundamental to the understanding of bandwidth exchange (BE) and time exchange (TE) enabled incentivized cooperative forwarding in wireless networks. We consider a network where N nodes transmit data in the uplink to an access point (AP) or base station (BS). We first consider the scenario where each node gets an initial amount (equal, optimal or arbitrary) of resource in the form of bandwidth or time, and uses this resource as a flexible incentive for two hop relaying. We focus on ?-fair network utility maximization (NUM) and total power minimization in this environment. For both BE and TE, we show the concavity or convexity of the resource allocation problem for a fixed relay set. Defining the link weights of each relay pair as the utility gain due to cooperation (over noncooperation), we show that the optimal relay selection, often a combinatorially cumbersome problem, reduces to the maximum weighted matching (MWM) ...
Optimal bandwidth-aware VM allocation for Infrastructure-as-a-Service
Dutta, Debojyoti; Post, Ian; Shinde, Rajendra
2012-01-01
Infrastructure-as-a-Service (IaaS) providers need to offer richer services to be competitive while optimizing their resource usage to keep costs down. Richer service offerings include new resource request models involving bandwidth guarantees between virtual machines (VMs). Thus we consider the following problem: given a VM request graph (where nodes are VMs and edges represent virtual network connectivity between the VMs) and a real data center topology, find an allocation of VMs to servers that satisfies the bandwidth guarantees for every virtual network edge---which maps to a path in the physical network---and minimizes congestion of the network. Previous work has shown that for arbitrary networks and requests, finding the optimal embedding satisfying bandwidth requests is $\\mathcal{NP}$-hard. However, in most data center architectures, the routing protocols employed are based on a spanning tree of the physical network. In this paper, we prove that the problem remains $\\mathcal{NP}$-hard even when the phys...
Staged optimization algorithms based MAC dynamic bandwidth allocation for OFDMA-PON
Liu, Yafan; Qian, Chen; Cao, Bingyao; Dun, Han; Shi, Yan; Zou, Junni; Lin, Rujian; Wang, Min
2016-06-01
Orthogonal frequency division multiple access passive optical network (OFDMA-PON) has being considered as a promising solution for next generation PONs due to its high spectral efficiency and flexible bandwidth allocation scheme. In order to take full advantage of these merits of OFDMA-PON, a high-efficiency medium access control (MAC) dynamic bandwidth allocation (DBA) scheme is needed. In this paper, we propose two DBA algorithms which can act on two different stages of a resource allocation process. To achieve higher bandwidth utilization and ensure the equity of ONUs, we propose a DBA algorithm based on frame structure for the stage of physical layer mapping. Targeting the global quality of service (QoS) of OFDMA-PON, we propose a full-range DBA algorithm with service level agreement (SLA) and class of service (CoS) for the stage of bandwidth allocation arbitration. The performance of the proposed MAC DBA scheme containing these two algorithms is evaluated using numerical simulations. Simulations of a 15 Gbps network with 1024 sub-carriers and 32 ONUs demonstrate the maximum network throughput of 14.87 Gbps and the maximum packet delay of 1.45 ms for the highest priority CoS under high load condition.
modeling the effect of bandwidth allocation on network performance
African Journals Online (AJOL)
a control algorithm that regulates the amount of bandwidth allocated to each ... planning, development and optimization of their networks. PROBLEM ... Network bandwidth design, simulation, and management ...... A Dictionary of Mechanical.
An Adaptive Bandwidth Allocation for Energy Efficient Wireless Communication Systems
Institute of Scientific and Technical Information of China (English)
Yung-Fa Huang,Che-Hao Li; Chuan-Bi Lin; Chia-Chi Chang
2015-01-01
Abstract―In this paper, an energy efficient bandwidth allocation scheme is proposed for wireless communication systems. An optimal bandwidth expansion (OBE) scheme is proposed to assign the available system bandwidth for users. When the system bandwidth does not reach the full load, the remaining bandwidth can be energy-efficiently assigned to the other users. Simulation results show that the energy efficiency of the proposed OBE scheme outperforms the traditional same bandwidth expansion (SBE) scheme. Thus, the proposed OBE can effectively assign the system bandwidth and improve energy efficiency.
Dynamic bandwidth allocation in GPON networks
DEFF Research Database (Denmark)
Ozimkiewiez, J.; Ruepp, Sarah Renée; Dittmann, Lars
2009-01-01
Two Dynamic Bandwidth Allocation algorithms used for coordination of the available bandwidth between end users in a GPON network have been simulated using OPNET to determine and compare the performance, scalability and efficiency of status reporting and non status reporting dynamic bandwidth allo...
Utility-based bandwidth allocation algorithm for heterogeneous wireless networks
Institute of Scientific and Technical Information of China (English)
CHAI Rong; WANG XiuJuan; CHEN QianBin; SVENSSON Tommy
2013-01-01
In next generation wireless network （NGWN）, mobile users are capable of connecting to the core network through various heterogeneous wireless access networks, such as cellular network, wireless metropolitan area network （WMAN）, wireless local area network （WLAN）, and ad hoc network. NGWN is expected to provide high-bandwidth connectivity with guaranteed quality-of-service to mobile users in a seamless manner; however, this desired function demands seamless coordination of the heterogeneous radio access network （RAN） technologies. In recent years, some researches have been conducted to design radio resource management （RRM） architectures and algorithms for NGWN; however, few studies stress the problem of joint network performance optimization, which is an essential goal for a cooperative service providing scenario. Furthermore, while some authors consider the competition among the service providers, the QoS requirements of users and the resource competition within access networks are not fully considered. In this paper, we present an interworking integrated network architecture, which is responsible for monitoring the status information of different radio access technologies （RATs） and executing the resource allocation algorithm. Within this architecture, the problem of joint bandwidth allocation for heterogeneous integrated networks is formulated based on utility function theory and bankruptcy game theory. The proposed bandwidth allocation scheme comprises two successive stages, i.e., service bandwidth allocation and user bandwidth allocation. At the service bandwidth allocation stage, the optimal amount of bandwidth for different types of services in each network is allocated based on the criterion of joint utility maximization. At the user bandwidth allocation stage, the service bandwidth in each network is optimally allocated among users in the network according to bankruptcy game theory. Numerical results demonstrate the efficiency of
A Preliminary Evaluation of Bandwidth Allocation Model Dynamic Switching
Directory of Open Access Journals (Sweden)
Rafael F. Reale
2014-06-01
Full Text Available Bandwidth Allocation Models (BAMs are used in order to define Bandwidth Constraints (BCs in a per-class basis for MPLS/DS-TE networks and effectively define how network resources like bandwidth are obtained and shared by applications. The BAMs proposed (MAM – Maximum Allocation Model, RDM – Russian Dolls Model, G-RDM – Generic RDM and AllocTC-Sharing attempt to optimize the use of bandwidth resources on a per-link basis with different allocation and resource sharing characteristics. As such, the adoption of distinct BAMs and/or changes in network resource demands (network traffic profile may result in different network traffic allocation and operational behavior for distinct BAMs. This paper evaluates the resulting network characteristics (li nk utilization, preemption and flows blocking of using BAMs dynamically with different traffic scenarios. In brief, it is investigated the dynamics of BAM switching with distinct traffic scenarios. The paper presents initially the investigated BAMs in relation to their behavior and resource allocation characteristics. Then, distinct BAMs are compared using different traffic scenarios in order to investigate the impact of a dynamic change of the BAM configured in the network. Finally, the paper shows that the adoption of a dynamic BAM allocation strategy may result in benefits for network operation in terms of link utilization, preemption and flows blocking.
Adaptive broadcasting mechanism for bandwidth allocation in mobile services.
Horng, Gwo-Jiun; Wang, Chi-Hsuan; Chou, Chih-Lun
2014-01-01
This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel's bandwidth and the data channel's bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.
An Improved Dynamic Bandwidth Allocation Algorithm for Ethernet PON
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
This paper proposes an improved Dynamic Bandwidth Allocation (DBA) algorithm for EPON, which combines static and traditional dynamic allocation schemes. Simulation result shows that the proposed algorithm may effectively improve the performance of packet delay.
Wu, Yating; Kuang, Bin; Wang, Tao; Zhang, Qianwu; Wang, Min
2015-12-01
This paper presents a minimum cost maximum flow (MCMF) based upstream bandwidth allocation algorithm, which supports differentiated QoS for orthogonal frequency division multiple access passive optical networks (OFDMA-PONs). We define a utility function as the metric to characterize the satisfaction degree of an ONU on the obtained bandwidth. The bandwidth allocation problem is then formulated as maximizing the sum of the weighted total utility functions of all ONUs. By constructing a flow network graph, we obtain the optimized bandwidth allocation using the MCMF algorithm. Simulation results show that the proposed scheme improves the performance in terms of mean packet delay, packet loss ratio and throughput.
Average Bandwidth Allocation Model of WFQ
Directory of Open Access Journals (Sweden)
Tomáš Balogh
2012-01-01
Full Text Available We present a new iterative method for the calculation of average bandwidth assignment to traffic flows using a WFQ scheduler in IP based NGN networks. The bandwidth assignment calculation is based on the link speed, assigned weights, arrival rate, and average packet length or input rate of the traffic flows. We prove the model outcome with examples and simulation results using NS2 simulator.
Bandwidth allocation and pricing problem for a duopoly market
Directory of Open Access Journals (Sweden)
You Peng-Sheng
2011-01-01
Full Text Available This research discusses the Internet service provider (ISP bandwidth allocation and pricing problems for a duopoly bandwidth market with two competitive ISPs. According to the contracts between Internet subscribers and ISPs, Internet subscribers can enjoy their services up to their contracted bandwidth limits. However, in reality, many subscribers may experience the facts that their on-line requests are denied or their connection speeds are far below their contracted speed limits. One of the reasons is that ISPs accept too many subscribers as their subscribers. To avoid this problem, ISPs can set limits for their subscribers to enhance their service qualities. This paper develops constrained nonlinear programming to deal with this problem for two competitive ISPs. The condition for reaching the equilibrium between the two competitive firms is derived. The market equilibrium price and bandwidth resource allocations are derived as closed form solutions.
Available Bandwidth Estimation Strategy Based on the Network Allocation Vector
Directory of Open Access Journals (Sweden)
Hongtao Liu
2012-12-01
Full Text Available Available bandwidth is of great importance to network Quality of Service assurance, network load balancing, streaming media rate control, routing, and congestion control, etc.. In this paper, the available bandwidth estimation strategy based on the Network Allocation Vector for Wireless Sensor Networks is proposed. According to the size of the average contention window, network nodes predict the probability of collision in process of frame transmission, and then estimate the number of retransmission. Through the collection of Hello packets periodically sent by neighbors, nodes obtain their Network Allocation Vector, and then estimate the available bandwidth. The simulation results show that the strategy is simple and effective, can accurately estimate the collision of data frames as well as the available bandwidth of Wireless Sensor Networks.
Performance Investigation of Virtual Private Networks with Different Bandwidth Allocations
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Ramaswamy Muthiah
2010-01-01
Full Text Available A Virtual Private Network (VPN provides private network connections over a publicly accessible shared network. The effective allocation of bandwidth for VPNs assumes significance in the present scenario due to varied traffic. Each VPN endpoint specifies bounds on the total amount of traffic that it is likely to send or receive at any time. The network provider tailors the VPN so that there is sufficient bandwidth for any traffic matrix that is consistent with these bounds. The approach incorporates the use of Ad-hoc On demand Distance Vector (AODV protocol, with a view to accomplish an enhancement in the performance of the mobile networks. The NS2 based simulation results are evaluated in terms of its metrics for different bandwidth allocations, besides analyzing its performance in the event of exigencies such as link failures. The results highlight the suitability of the proposed strategy in the context of real time applications.
A novel dynamic wavelength bandwidth allocation scheme over OFDMA PONs
Yan, Bo; Guo, Wei; Jin, Yaohui; Hu, Weisheng
2011-12-01
With rapid growth of Internet applications, supporting differentiated service and enlarging system capacity have been new tasks for next generation access system. In recent years, research in OFDMA Passive Optical Networks (PON) has experienced extraordinary development as for its large capacity and flexibility in scheduling. Although much work has been done to solve hardware layer obstacles for OFDMA PON, scheduling algorithm on OFDMA PON system is still under primary discussion. In order to support QoS service on OFDMA PON system, a novel dynamic wavelength bandwidth allocation (DWBA) algorithm is proposed in this paper. Per-stream QoS service is supported in this algorithm. Through simulation, we proved our bandwidth allocation algorithm performs better in bandwidth utilization and differentiate service support.
Allocating Bandwidth in Datacenter Networks：A Survey
Institute of Scientific and Technical Information of China (English)
陈丽; 李葆春; 李波
2014-01-01
Datacenters have played an increasingly essential role as the underlying infrastructure in cloud computing. As implied by the essence of cloud computing, resources in these datacenters are shared by multiple competing entities, which can be either tenants that rent virtual machines (VMs) in a public cloud such as Amazon EC2, or applications that embrace data parallel frameworks like MapReduce in a private cloud maintained by Google. It has been generally observed that with traditional transport-layer protocols allocating link bandwidth in datacenters, network traffic from competing applications interferes with each other, resulting in a severe lack of predictability and fairness of application performance. Such a critical issue has drawn a substantial amount of recent research attention on bandwidth allocation in datacenter networks, with a number of new mechanisms proposed to efficiently and fairly share a datacenter network among competing entities. In this article, we present an extensive survey of existing bandwidth allocation mechanisms in the literature, covering the scenarios of both public and private clouds. We thoroughly investigate their underlying design principles, evaluate the trade-off involved in their design choices and summarize them in a unified design space, with the hope of conveying some meaningful insights for better designs in the future.
Dynamic and balanced capacity allocation scheme with uniform bandwidth for OFDM-PON systems
Lei, Cheng; Chen, Hongwei; Chen, Minghua; Yu, Ying; Guo, Qiang; Yang, Sigang; Xie, Shizhong
2015-03-01
As the bitrate of orthogonal frequency division multiplexing passive optical network (OFDM-PON) system is continuously increasing, how to effectively allocate the system bandwidth among the huge number of optical network units (ONUs) is one of the key problems before OFDM-PON can be practical deployed. Unlike traditional bandwidth allocation scheme, in this paper, the transmission performance of single ONU is for the first time taken into consideration and optimized. To reduce the manufacturing complexity and fully utilize the processing ability of the receivers, the system bandwidth is equally distributed to the ONUs. Bit loading is used to allocate the total transmission capacity, and power loading is used to guarantee the ONUs have balanced transmission performance even if they operate at different bitrate. In this way, a dynamic and balanced capacity allocation scheme with uniform bandwidth for OFDM-PON systems can be realized. At last, an experimental system is established to verify the feasibility of the proposed scheme, and the influence that the scheme brings to the whole system is also analyzed.
Bandwidth and power allocation for two-way relaying in overlay cognitive radio systems
Alsharoa, Ahmad M.
2014-12-01
In this paper, the problem of both bandwidth and power allocation for two-way multiple relay systems in overlay cognitive radio (CR) setup is investigated. In the CR overlay mode, primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In our framework, we propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as an amplify-and-forward two-way relays, they are used to support PUs to achieve their target data rates over the remaining bandwidth. More specifically, CUs acts as relays for the PUs and gain some spectrum as long as they respect a specific power budget and primary quality-of-service constraints. In this context, we first derive closed-form expressions for optimal transmit power allocated to PUs and CUs in order to maximize the cognitive objective. Then, we employ a strong optimization tool based on particle swarm optimization algorithm to find the optimal relay amplification gains and optimal cognitive released bandwidths as well. Our numerical results illustrate the performance of our proposed algorithm for different utility metrics and analyze the impact of some system parameters on the achieved performance.
Optimal Joint Multiple Resource Allocation Method for Cloud Computing Environments
Kuribayashi, Shin-ichi
2011-01-01
Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources. To provide cloud computing services economically, it is important to optimize resource allocation under the assumption that the required resource can be taken from a shared resource pool. In addition, to be able to provide processing ability and storage capacity, it is necessary to allocate bandwidth to access them at the same time. This paper proposes an optimal resource allocation method for cloud computing environments. First, this paper develops a resource allocation model of cloud computing environments, assuming both processing ability and bandwidth are allocated simultaneously to each service request and rented out on an hourly basis. The allocated resources are dedicated to each service request. Next, this paper proposes an optimal joint multiple resource allocation method, based on the above resource allocation model. It is demonstrated by simulation evaluation that the p...
UNIFORM—PRICE AUCTION FOR BANDWIDTH ALLOCATION IN THE INTERNET
Institute of Scientific and Technical Information of China (English)
WeiJiaolong; ZhangChi
2002-01-01
It has been widely accepted that auctioning which is the pricing approach with minimal information requirement is a proper tool to manage scare network resources.Previous works focus on vickrey auction which is incentive compatible in classic auction theory.In the beginning of this letter,the faults of the most representative auction-based mechanisms are discussed.And then a new method called Uniform-Price Auction(UPA),which has the simplest auctiopn rule is proposed and its incentive compatibility in the network environment is also proved.Finally,the basic mode is extended to support applications which require minimum bandwidth guarantees for a given time period by introducing derivative market.and a market mechanism for network resource allocation which is predictable,riskless,and simple for eng-users is completed.
Auction-based bandwidth allocation in the Internet
Wei, Jiaolong; Zhang, Chi
2002-07-01
It has been widely accepted that auctioning which is the pricing approach with minimal information requirement is a proper tool to manage scare network resources. Previous works focus on Vickrey auction which is incentive compatible in classic auction theory. In the beginning of this paper, the faults of the most representative auction-based mechanisms are discussed. And then a new method called uniform-price auction (UPA), which has the simplest auction rule is proposed and it's incentive compatibility in the network environment is also proved. Finally, the basic mode is extended to support applications which require minimum bandwidth guarantees for a given time period by introducing derivative market, and a market mechanism for network resource allocation which is predictable, riskless, and simple for end-users is completed.
UNIFORM-PRICE AUCTION FOR BANDWIDTH ALLOCATION IN THE INTERNET
Institute of Scientific and Technical Information of China (English)
Wei Jiaolong; Zhang Chi
2002-01-01
It has been widely accepted that auctioning which is the pricing approach with minimal information requirement is a proper tool to manage scare network resources. Previous works focus on Vickrey auction which is incentive compatible in classic auction theory. In the beginning of this letter, the faults of the most representative auction-based mechanisms are discussed. And then a new method called Uniform-Price Auction (UPA), which has the simplest auction rule is proposed and its incentive compatibility in the network environment is also proved. Finally, the basic mode is extended to support applications which require minimum bandwidth guarantees for a given time period by introducing derivative market, and a market mechanism for network resource allocation which is predictable, riskless, and simple for end-users is completed.
JOINT RESOURCE ALLOCATION FOR WLAN&WCDMA INTEGRATED NETWORKS BASED ON SPECTRAL BANDWIDTH MAPPING
Institute of Scientific and Technical Information of China (English)
Pan Su; Ye Qiang; Liu Shengmei; Zhou Dawei
2011-01-01
Next wireless network aims to integrate heterogeneous wireless access networks by sharing wireless resource.The spectral bandwidth mapping concept is proposed to uniformly describe the resource in heterogeneous wireless networks.The resources of codes and power levels in WCDMA system as well as statistical time slots in WLAN are mapped into equivalent bandwidth which can be allocated in different networks and layers.The equivalent bandwidth is jointly distributed in call admission and vertical handoff control process in an integrated WLAN/WCDMA system to optimize the network utility and guarantee the heterogeneous QoS required by calls.Numerical results show that,when the incoming traffic is moderate,the proposed scheme could receive 5％-10％ increase of system revenue compared to the MDP based algorithms.
A novel bandwidth allocation scheme for QoS routing in mobile ad hoc networks
Wu, Bin; Kuo, Geng-Sheng
2004-09-01
The main purpose of this paper is to propose a novel bandwidth allocation scheme for facilitating quality of service (QoS) routing in mobile ad hoc networks (MANETs). In a MANET using time division multiple access (TDMA), each node communicates with its neighbors in the same time slot. In general, finding a route with the maximum end-to-end bandwidth subject to the constraint of collision-free transmission is an NP-complete problem. This paper proposed a sub-optimal solution to this problem. The solution is based on a centrally controlled bandwidth allocation scheme to properly assign the available time slots to each intermediate link. The advantage of our proposed scheme is that the resource utilization of MANET is maximized and the end-to-end QoS is guaranteed during the route establishment period. Performance analyses show that when using the proposed scheme with AODV to perform QoS routing, it achieves about 25% throughput higher than its best-effort counterpart if the node is moving at 5mps speed.
Power allocation, bit loading and sub-carrier bandwidth sizing for OFDM-based cognitive radio
Directory of Open Access Journals (Sweden)
Desai Uday
2011-01-01
Full Text Available Abstract The function of the Radio Resource Management module of a Cognitive Radio (CR system is to evaluate the available resources and assign them to meet the Quality of Service (QoS objectives of the Secondary User (SU, within some constraints on factors which limit the performance of the Primary User (PU. While interference mitigation to the PU spectral band from the SU's transmission has received a lot of attention in recent literature; the novelty of our work is in considering a more realistic and effective approach of dividing the PU into sub-bands, and ensuring that the interference to each of them is below a specified threshold. With this objective, and within a power budget, we execute the tasks of power allocation, bit loading and sizing the sub-carrier bandwidth for an orthogonal frequency division multiplexing (OFDM-based SU. After extensively analyzing the solution form of the optimization problems posed for the resource allocation, we suggest iterative algorithms to meet the aforementioned objectives. The algorithm for sub-carrier bandwidth sizing is novel, and not previously presented in literature. A multiple SU scenario is also considered, which entails assigning sub-carriers to the users, besides the resource allocation. Simulation results are provided, for both single and multi-user cases, which indicate the effectiveness of the proposed algorithms in a CR environment.
Alsharoa, Ahmad
2015-10-08
This paper studies the achievable cognitive sum rate of an overlay cognitive radio (CR) system assisted with multiple antennas two-way relays in which primary users (PUs) cooperate with cognitive users (CUs) for mutual benefits. In this context, the problem of both bandwidth and power allocation is investigated. We propose that the CUs are allowed to allocate a part of the PUs spectrum to perform their cognitive transmission. In return, acting as amplify-and-forward two-way relays, they are exploited to support PUs to reach their target data rates over the remaining bandwidth. Power expressions for optimal transmit power allocated per PU and CU antenna are derived under primary quality-of-service constraint in addition to bandwidth and power budget constraints. More specifically, CUs act as relays for the PUs transmission and gain some spectrum as long as they respect these constraints. After deriving the optimal transmit powers, we employ a strong optimization tool based on swarm intelligence to optimize the full and complex relay amplification gain matrices in addition to the bandwidths released to primary and cognitive transmission. Furthermore, three different utility functions are considered in our optimization problems depending on the level of fairness among CUs.
Bandwidth Resource Dynamic Allocation in Differentiated Services Model%Diffserv中带宽代理BB的实现
Institute of Scientific and Technical Information of China (English)
邱瑜; 朱淼良
2003-01-01
To employ Differentiated Services, efficient and flexible resource allocation mechanism is needed. Static bandwidth resource allocation Is not suitable for the situations in which traffic varies greatly with times. If customers bought bandwidth according to their highest traffic demands, some resource will be wasted when traffic load is light. On the other hand, the static allocated bandwidth may not satisfy the growing traffic demands. So it is necessary to allocate bandwidth resource in dynamic way. We bring up a prototype of BB, discussing the necessary components to realize the dynamic bandwidth resource allocation and further more, our BB can provides advanced reservation for bandwidth resource. Simulation tests show our design is feasible.
PRIORITY BASED BANDWIDTH ALLOCATION IN WIRELESS SENSOR NETWORKS
Directory of Open Access Journals (Sweden)
Mary Cherian
2014-12-01
Full Text Available Most of the sensor network applications need real time communication and the need for deadline aware real time communication is becoming eminent in these applications. These applications have different dead line requirements also. The real time applications of wireless sensor networks are bandwidth sensitive and need higher share of bandwidth for higher priority data to meet the dead line requirements. In this paper we focus on the MAC layer modifications to meet the real time requirements of different priority data. Bandwidth partitioning among different priority transmissions is implemented through MAC layer modifications. The MAC layer implements a queuing model that supports lower transfer rate for lower priority packets and higher transfer rate for real time packets with higher priority, minimizing the end to end delay. The performance of the algorithm is evaluated with varying node distribution.
Assessing the efficiency of resource allocations in bandwidth-sharing networks
I.M. Verloop (Maaike); R. Núñez Queija (Rudesindo (Sindo))
2007-01-01
textabstractResource allocation in bandwidth-sharing networks is inherently complex: The distributed nature of resource allocation management prohibits global coordination for efficiency, i.e., aiming at full resource usage at all times. In addition, it is well recognized that resource efficiency
Assessing the efficiency of resource allocations in bandwidth-sharing networks
Verloop, I.M.; Núñez-Queija, R.
2009-01-01
Resource allocation in bandwidth-sharing networks is inherently complex: the distributed nature of resource allocation management prohibits global coordination for efficiency, i.e., aiming at full resource usage at all times. In addition, it is well recognized that resource efficiency may conflict
Directory of Open Access Journals (Sweden)
Ziyi Fu
2012-10-01
Full Text Available According to the upstream TDM in the system of Ethernet passive optical network (EPON, this paper proposes a novel dynamic bandwidth allocation algorithm which supports the mechanism with correction-based the multiple services estimation. To improve the real-time performance of the bandwidth allocation, this algorithm forecasts the traffic of high priority services, and then pre-allocate bandwidth for various priority services is corrected according to Gaussian distribution characteristics, which will make traffic prediction closer to the real traffic. The simulation results show that proposed algorithm is better than the existing DBA algorithm. Not only can it meet the delay requirement of high priority services, but also control the delay abnormity of low priority services. In addition, with rectification scheme, it obviously improves the bandwidth utilization.
Institute of Scientific and Technical Information of China (English)
ZhangLiangjie; LiYanda; 等
1997-01-01
In this paper,a dynamic bandwidth allocation technique based on fuzz neural networks(FNNs) and genetic algorithm(GA)is proposed for preventive congestion control in ATM network.The traffic model based on FNN does not need the descriptive traffic parameters in detail,which greatly depend on the user's terminal.Genetic algorithm is used to predict the equivalent bandwidth of the accepted traffic in real-time.Thus,the proposed scheme can estimate the dynamic bandwidth of the network in the time scale from the call arrival to the call admission/rejection due to the fuzzy-tech and GA hardware implementation.Simulation results show that the scheme can perform accurate dynamic bandwidth allocation to DN/OFF bursty traffic in accordance with the required quality of service(QOS),and the bandwidth utilization is improved from the overall point of view.
Bandwidth allocation for video under quality of service constraints
Anjum, Bushra
2014-01-01
We present queueing-based algorithms to calculate the bandwidth required for a video stream so that the three main Quality of Service constraints, i.e., end-to-end delay, jitter and packet loss, are ensured. Conversational and streaming video-based applications are becoming a major part of the everyday Internet usage. The quality of these applications (QoS), as experienced by the user, depends on three main metrics of the underlying network, namely, end-to-end delay, jitter and packet loss. These metrics are, in turn, directly related to the capacity of the links that the video traffic trave
A hybrid OFDM-TDM architecture with decentralized dynamic bandwidth allocation for PONs.
Cevik, Taner
2013-01-01
One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand.
A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs
Cevik, Taner
2013-01-01
One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand. PMID:24194684
Directory of Open Access Journals (Sweden)
Xiang Yan
2013-01-01
Full Text Available This paper addresses the optimal bandwidth scheduling problem for a double-layer networked learning control system (NLCS. To deal with this issue, auction mechanism is employed, and a dynamic bandwidth scheduling methodology is proposed to allocate the bandwidth for each subsystem. A noncooperative game fairness model is formulated, and the utility function of subsystems is designed. Under this framework, estimation of distribution algorithm (EDA is used to obtain Nash equilibrium for NLCS. Finally, simulation and experimental results are given to demonstrate the effectiveness of the proposed approach.
Effective Bandwidth Allocation for WiMAX Mesh Network
Directory of Open Access Journals (Sweden)
Hung-Chin Jang
2010-04-01
Full Text Available The aim of this paper is to reduce the media access delay in a WiMAX mesh network. We observe that as the number of subscriber stations (SS in a neighborhood increases, the processes of transmission opportunity (TO competition and 3- way handshake are easy to fail. This may degrade transmission efficiency and increase packet transmission delay. Besides, the minislot allocation defined in the WiMAX mesh mode may cause many lower priority services reserve earlier minislots than that of higher priority services like rtPS. This may cause great negative impact on delay-sensitive traffic. In this paper, we design a QoS classifier to enqueue packets according to different QoS service classes, present a dynamic holdoff exponent mechanism to reduce control subframe delay, and propose a Neighborhood-Based Minislot Allocation (NBMA mechanism to reduce data subframe delay. Simulations show that the proposed methodology outperforms that of IEEE 802.16 and Baye's DynExp in delay, jitter and throughput.
Institute of Scientific and Technical Information of China (English)
Zhengcheng Xie; Hui Li; Yuefeng Ji
2009-01-01
Cyclic polling-based dynamic wavelength and bandwidth allocation algorithm supporting differentiated classes of services in wavelength division multiplexing (WDM) passive optical networks (PONs) is proposed. In this algorithm, the optical line terminal (OLT) polls for optical network unit (ONU) requests to transmit data in a cyclic manner. Services are categorized into three classes: expedited forward (EF) priority, assured forwarding (AF) priority, and best effort (BE) priority. The OLT assigns bandwidth for different priorities with different strategies. Simulation results show that the proposed algorithm saves a lot of downstream bandwidth under low load and does not show the light-load penalty compared with the simultaneous and interleaved polling schemes.
Frequency Bandwidth Optimization of Left-Handed Metamaterial
Chevalier, Christine T.; Wilson, Jeffrey D.
2004-01-01
Recently, left-handed metamaterials (LHM s) have been demonstrated with an effective negative index of refraction and with antiparallel group and phase velocities for microwave radiation over a narrow frequency bandwidth. In order to take advantage of these characteristics for practical applications, it will be beneficial to develop LHM s with increased frequency bandwidth response and lower losses. In this paper a commercial three-dimensional electromagnetic simulation code is used to explore the effects of geometry parameter variations on the frequency bandwidth of a LHM at microwave frequencies. Utilizing an optimizing routine in the code, a geometry was generated with a bandwidth more than twice as large as the original geometry.
Efficient Bandwidth Allocation for Integrated Services in Broadband Wireless ATM Networks
DEFF Research Database (Denmark)
Liu, Hong; Dittmann, Lars; Gliese, Ulrik Bo
1999-01-01
An efficient bandwidth allocation scheme is proposed for supporting intergrated services in wireless ATM networks. These include CBR, VBR amd ABR types of traffic. The proposed scheme is based om A-PRMA for carrying ATM traffic in a dynamic TDMA type access system. It allows mobile users to adjust...
Optimal resource allocation for distributed video communication
He, Yifeng
2013-01-01
While most books on the subject focus on resource allocation in just one type of network, this book is the first to examine the common characteristics of multiple distributed video communication systems. Comprehensive and systematic, Optimal Resource Allocation for Distributed Video Communication presents a unified optimization framework for resource allocation across these systems. The book examines the techniques required for optimal resource allocation over Internet, wireless cellular networks, wireless ad hoc networks, and wireless sensor networks. It provides you with the required foundat
On the Ramified Optimal Allocation Problem
Xia, Qinglan
2011-01-01
This paper proposes an optimal allocation problem with ramified transport technology in a spatial economy. Ramified transportation is used to model the transport economy of scale in group transportation observed widely in both nature and efficiently designed transport systems of branching structures. The ramified allocation problem aims at finding an optimal allocation plan as well as an associated optimal allocation path to minimize overall cost of transporting commodity from factories to households. This problem differentiates itself from existing ramified transportation literature in that the distribution of production among factories is not fixed but endogenously determined as observed in many allocation practices. It's shown that due to the transport economy of scale in ramified transportation, each optimal allocation plan corresponds equivalently to an optimal assignment map from households to factories. This optimal assignment map provides a natural partition of both households and allocation paths. We...
A mechanism design approach to bandwidth allocation in tactical data networks
Mour, Ankur
The defense sector is undergoing a phase of rapid technological advancement, in the pursuit of its goal of information superiority. This goal depends on a large network of complex interconnected systems - sensors, weapons, soldiers - linked through a maze of heterogeneous networks. The sheer scale and size of these networks prompt behaviors that go beyond conglomerations of systems or `system-of-systems'. The lack of a central locus and disjointed, competing interests among large clusters of systems makes this characteristic of an Ultra Large Scale (ULS) system. These traits of ULS systems challenge and undermine the fundamental assumptions of today's software and system engineering approaches. In the absence of a centralized controller it is likely that system users may behave opportunistically to meet their local mission requirements, rather than the objectives of the system as a whole. In these settings, methods and tools based on economics and game theory (like Mechanism Design) are likely to play an important role in achieving globally optimal behavior, when the participants behave selfishly. Against this background, this thesis explores the potential of using computational mechanisms to govern the behavior of ultra-large-scale systems and achieve an optimal allocation of constrained computational resources Our research focusses on improving the quality and accuracy of the common operating picture through the efficient allocation of bandwidth in tactical data networks among self-interested actors, who may resort to strategic behavior dictated by self-interest. This research problem presents the kind of challenges we anticipate when we have to deal with ULS systems and, by addressing this problem, we hope to develop a methodology which will be applicable for ULS system of the future. We build upon the previous works which investigate the application of auction-based mechanism design to dynamic, performance-critical and resource-constrained systems of interest
Optimal filter bandwidth for pulse oximetry
Stuban, Norbert; Niwayama, Masatsugu
2012-10-01
Pulse oximeters contain one or more signal filtering stages between the photodiode and microcontroller. These filters are responsible for removing the noise while retaining the useful frequency components of the signal, thus improving the signal-to-noise ratio. The corner frequencies of these filters affect not only the noise level, but also the shape of the pulse signal. Narrow filter bandwidth effectively suppresses the noise; however, at the same time, it distorts the useful signal components by decreasing the harmonic content. In this paper, we investigated the influence of the filter bandwidth on the accuracy of pulse oximeters. We used a pulse oximeter tester device to produce stable, repetitive pulse waves with digitally adjustable R ratio and heart rate. We built a pulse oximeter and attached it to the tester device. The pulse oximeter digitized the current of its photodiode directly, without any analog signal conditioning. We varied the corner frequency of the low-pass filter in the pulse oximeter in the range of 0.66-15 Hz by software. For the tester device, the R ratio was set to R = 1.00, and the R ratio deviation measured by the pulse oximeter was monitored as a function of the corner frequency of the low-pass filter. The results revealed that lowering the corner frequency of the low-pass filter did not decrease the accuracy of the oxygen level measurements. The lowest possible value of the corner frequency of the low-pass filter is the fundamental frequency of the pulse signal. We concluded that the harmonics of the pulse signal do not contribute to the accuracy of pulse oximetry. The results achieved by the pulse oximeter tester were verified by human experiments, performed on five healthy subjects. The results of the human measurements confirmed that filtering out the harmonics of the pulse signal does not degrade the accuracy of pulse oximetry.
Directory of Open Access Journals (Sweden)
Kuda Nageswara Rao
2010-07-01
Full Text Available This paper deals with the performance evaluation of a two node communication network with dynamic bandwidth allocation and modified phase type transmission having bulk arrivals. The performance of the statistical multiplexing is measured by approximating with the compound Poisson process and the transmission completions with Poisson processes. It is further assumed that the transmission rate at each node are adjusted depending upon the content of the buffer which is connected to it. The packets transmitted through the first node may be forwarded to the buffer connected to the second node or get terminated with certain probabilities. The performance measures of the network like, mean content of the buffers, mean delays, throughput, transmitter utilization etc. are derived explicitly under transient conditions. Sensitivity analysis with respect to the parameters is also carried through numerical illustration. It is observed that the dynamic bandwidth allocation and batch size distribution of arrivals has a tremendous influence on the performance measures.
QoS-aware dynamic bandwidth allocation algorithm for Gigabit-capable PONS
Institute of Scientific and Technical Information of China (English)
WANG Xin; ZHAO Yang; GU Wanyi
2007-01-01
The Gigabit-capable passive optical network (GPON)technology is being considered as a promising solution for the next-generation broadband access network.Since the network topology of the GPON is point-to-multipoint,a media access control called dynamic bandwidth allocation(DBA)algorithm is an important factor for determining the performance of the GPON.In this paper,we propose a new DBA algorithm to effectively and fairly allocate bandwidths among end users.This DBA algorithm supports difierentiated services-a cmcial requirement for a converged broadband access network with heterogeneous traffic.In this article we first reviewed the signaling and configuration of the DBA,and then proposed a new DBA scheme that implemented QoS-based priority for this need to maximally satisfy the requirements of all optical network units(ONUs)and provide difierentiated services.Analyses and simulation results show that the new algorithm can improve the bandwidth utilization and realize the fairness for both different ONUs and services.
Dynamic Bandwidth Allocation Algorithm with Fairness in 1G/10G Coexistence EPON System
Tanaka, Masaki; Takemoto, Michiya; Takahashi, Akira; Shimokasa, Kiyoshi
Gigabit Ethernet Passive Optical Networks (GE-PON) systems have been deployed widely as a broadband access solution for the optical access network, the so-called FTTx networks. 10 Gigabit EPON (10G-EPON) is about to be standardizing by a task force (802.3av). To provide the next FTTx solution with 10G-EPON systems, one of the key technologies is how to migrate from 1G-based to 10G-based. In this paper, we present Dynamic Bandwidth Allocation (DBA) algorithm which considered a fair policy for 1G/10G coexistence EPON system to achieve a smooth migration.
Bandwidth Optimization in Centralized WLANs for Different Traffic Types
Directory of Open Access Journals (Sweden)
Haines RJ
2007-01-01
Full Text Available Allocating bandwidth between different forms of coexisting traffic (such as web-browsing, streaming, and telephony within a wireless LAN is a challenging and interesting problem. Centralized coordination functions in wireless LANs offer several advantages over distributed approaches, having the benefit of a system overview at the controller, but obtaining a stable configuration of bandwidth allocation for the system is nontrivial. We present, review, and compare different mechanisms to achieve this end, and a number of different means of obtaining the configurations themselves. We describe an analytical model of the system under consideration and present two mathematical approaches to derive solutions for any system configuration and deployment, along with an adaptive feedback-based solution. We also describe a comprehensive simulation-based model for the problem, and a prototype that allows comparison of these approaches. Our investigations demonstrate that a self-adaptive dynamic approach far outperforms any static scheme, and that using a mathematical model to produce the configurations themselves confers several advantages.
Quantum gates with optimal bandwidth in noisy environments
Low, Guang Hao; Theodore, Yoder; Chuang, Isaac
The traditional approach of open-loop quantum error correction suppresses certain systematic imperfections ɛ in quantum control to higher orders ɛ (L) by a well-designed sequence of L imperfect quantum gates. However, this philosophy of maximal flatness leads to an ɛ-bandwidth that scales poorly with length and a residual that is easily overwhelmed by unaccounted sources of noise. We advance the paradigm of equiripple compensated gates that directly optimize for bandwidth given the limitations imposed by noise of magnitude δ, leading to dramatically improved performance. Where ɛ represent amplitude errors, we provide a formalism that generalizes both approaches and is effective at finding such gates. With it, we provide in closed-form the phase angles for an optimal family of population inversion gates with an ɛ -bandwidth of (logδ-1/L) - a quadratic improvement over optimal maximally flat variants. We also construct optimal NOT gates and discuss extensions to other gates and error models.
Optimality versus stability in water resource allocation.
Read, Laura; Madani, Kaveh; Inanloo, Bahareh
2014-01-15
Water allocation is a growing concern in a developing world where limited resources like fresh water are in greater demand by more parties. Negotiations over allocations often involve multiple groups with disparate social, economic, and political status and needs, who are seeking a management solution for a wide range of demands. Optimization techniques for identifying the Pareto-optimal (social planner solution) to multi-criteria multi-participant problems are commonly implemented, although often reaching agreement for this solution is difficult. In negotiations with multiple-decision makers, parties who base decisions on individual rationality may find the social planner solution to be unfair, thus creating a need to evaluate the willingness to cooperate and practicality of a cooperative allocation solution, i.e., the solution's stability. This paper suggests seeking solutions for multi-participant resource allocation problems through an economics-based power index allocation method. This method can inform on allocation schemes that quantify a party's willingness to participate in a negotiation rather than opt for no agreement. Through comparison of the suggested method with a range of distance-based multi-criteria decision making rules, namely, least squares, MAXIMIN, MINIMAX, and compromise programming, this paper shows that optimality and stability can produce different allocation solutions. The mismatch between the socially-optimal alternative and the most stable alternative can potentially result in parties leaving the negotiation as they may be too dissatisfied with their resource share. This finding has important policy implications as it justifies why stakeholders may not accept the socially optimal solution in practice, and underlies the necessity of considering stability where it may be more appropriate to give up an unstable Pareto-optimal solution for an inferior stable one. Authors suggest assessing the stability of an allocation solution as an
Energy-saving EPON Bandwidth Allocation Algorithm Supporting ONU's Sleep Mode
Zhang, Yinfa; Ren, Shuai; Liao, Xiaomin; Fang, Yuanyuan
2014-09-01
A new bandwidth allocation algorithm was presented by combining merits of the IPACT algorithm and the cyclic DBA algorithm based on the DBA algorithm for ONU's sleep mode. Simulation results indicate that compared with the normal mode ONU, the ONU's sleep mode can save about 74% of energy. The new algorithm has a smaller average packet delay and queue length in the upstream direction. While in the downstream direction, the average packet delay of the new algorithm is less than polling cycle Tcycle and the average queue length is less than the product of Tcycle and the maximum link rate. The new algorithm achieves a better compromise between energy-saving and ensuring quality of service.
Luo, Yuanqiu; Ansari, Nirwan
2005-09-01
Feature Issue on Optical Access Networks (OAN) As an inexpensive, simple, and scalable solution for broadband access, Ethernet passive optical networks (EPONs) have the capability of delivering integrated broadband services to the end users. A critical issue of EPONs is the utility of a shared upstream channel among the local users, and thus an efficient bandwidth allocation mechanism is required to facilitate statistical multiplexing among the local network traffic. In this paper we propose a dynamic bandwidth allocation scheme, i.e., limited sharing with traffic prediction (LSTP), for upstream channel sharing over EPONs. LSTP enables dynamic bandwidth negotiation between the optical line terminal (OLT) and its associated optical network units (ONUs), alleviates data delay by predicting the traffic arrived during the waiting time and prereserving a portion of bandwidth for delivery, and avoids the aggressive bandwidth competition by upper bounding the allocated bandwidth to each ONU. Theoretical analysis and simulation results verify the feasibility of LSTP by showing that LSTP outperforms other existing schemes with respect to QoS metrics of data delay and data loss.
Optimization of bandwidth of communication channels of corporate networks
Directory of Open Access Journals (Sweden)
G. I. Bondarenko
2014-09-01
Full Text Available Introduction. This article contains overview of the organization of communication between applications on the corporate network. It is stated that the main digital channel (channel B - 64 kbit/s and the primary digital channel (channel E1 the digital stream - 2048 kbit/s are used as the main channels in corporate networks. Problem areas of the functioning of the corporate network are identified. There are the rent of communication channels, which is growing rapidly with increasing the quality and speed of data transmission, and optimal use of bandwidth of communication channels. Setting of task. Optimal use of transmission channels bandwidth and minimizing the rent cost of channels is possible in two ways - the use of compression techniques of voice and video information and the application of variable structure of channels by using various-speed transmission channels. Differential pulse code modulation, adaptive differential pulse code modulation are the modern methods of speech signals processing. Organization of various-speed channels is performed in the structure of the BCC (for speech signals or PCR (for video. Suggestions for optimizing the structure of the channel signals. Proposed method of various-speed channels formation by using the channel intervals appropriate BCC (octets in the structure of signals E1 as envelopes containing various-speed channels. Channels can be selected for synchronization procedure CRC to simplify recognition of channels in the structure of E1. In this case, the minimal speed in the channel is 4 kbit/s. Conclusions. The proposed structure of envelopes is based on octet channel intervals of standard group signal of the primary group plesiochronous hierarchy E1 when transferring various-speed digital signals maximum allows to use the bandwidth at a fixed structure of channel interval, it makes possible to agree on the structure of the various-speed signals with the existing in communication networks.
RAOPS: Resource Allocation Optimization Program for Safegurards
Energy Technology Data Exchange (ETDEWEB)
Zardecki, A.; Markin, J.T.
1994-03-01
RAOPS--Resource Allocation Optimization Program for Safeguards is extended to a multiobjective return function having the detection probability and expected detection time as criteria. The expected detection time is included as a constraint, based on the well-known Avenhaus model of the optimum number of inventory periods. Examples of computation are provided.
Institute of Scientific and Technical Information of China (English)
孟飞; 兰巨龙; 胡宇翔
2016-01-01
数据中心（data center ，DC）之间通过部署流量工程来提高连接各个数据中心骨干网的利用率，虽然效率提升显著，但对不同类型汇聚流的带宽分配的公平性没有考虑。将多个汇聚流对带宽分配的竞争行为建模为一个合作博弈，通过寻求此博弈的纳什谈判解（Nash bargaining solution ，NBS）来确定优化的带宽分配策略 CGBA（cooperation game based bandwidth allocation ），权衡各汇聚流的最小带宽保证与带宽分配的公平性。在 Mininet 平台上进行实验仿真并和典型的带宽分配策略对比，结果表明CGBA 不但可保证各汇聚流的最小带宽需求，还确保了各类流对带宽资源竞争的公平性。%Currently ,traffic engineering is typically deployed to improve the utilization of data centers (DC) backbone networks ,which usually belongs to the same online service providers .Although the efficiency is remarkable ,the bandwidth allocation fairness of different aggregate flow isn’t considered . Hence ,the QoS guarantee is restricted .Because the bandwidth resource is expensive and packet loss is typically thought unacceptable ,the bandwidth utilization should be maximized ,at the same time , the QoS guarantee of different flow should be improved .In this paper ,the problem of contending the share bandwidth is modeled as a cooperative game ,and different aggregate flow compets the share bandwidth and maximizes the overall bandwidth resource utilization simultaneously ,and the optimal bandwidth allocation policy ,called cooperation game based bandwidth allocation (CGBA) ,is obtained through searching the Nash bargaining solution (NBS) of the game and balancing the tradeoff between minimum bandwidth guarantee and bandwidth allocation fairness .Simulation on a Mininet testbed shows that the proposed policy can effectively guarantee minimum bandwidth of each aggregate flow while ensuring the allocation fairness , compared with three
Discussion of Optimal Allocation of Resources Theory for Communication Enterprises
Institute of Scientific and Technical Information of China (English)
JIN Xiao-lin; YU Hua; SU Hua-ying
2004-01-01
The theory on the resource optimal allocation is discussed in this article. On the base of the discussion, for the main problems existing in the resource allocation of communication enterprises, the reasonable allocating measures are put forward.
Cluster Formation and Joint Power-Bandwidth Allocation for Imperfect NOMA in DL-HetNets
Celik, Abdulkadir
2017-04-15
Non-orthogonal multiple access (NOMA) has recently drawn attentions on its ability to fairly serve multiple users on the same radio resource with a desirable performance. However, achievable NOMA gain is primarily limited by channel gain disparity and successive interference cancellation (SIC) receiver characteristics. Accordingly, we introduce an imperfect SIC receiver model considering the power disparity and sensitivity constraints, delay tolerance, and residual interference due to detection and estimation errors. Then, a generic cluster formation (CF) and Power-Bandwidth Allocation (PBA) is formulated as a mixed-integer non-linear programming (MINLP) problem for downlink (DL) heterogeneous networks (HetNets). After dividing the MINLP problem into mixed-integer and non-linear subprobems, we first transform CF into a multi-partite matching, which is solved sequentially using bi-partite matching techniques. For sumrate maximization, max-min fairness, and energy & spectrum efficiency objectives, we secondly put highly non-convex joint PBA into a convex form using geometric programming (GP). Extensive simulations unleash the potential of NOMA to handle large number of users, traffic offloading, and user fairness.
Dias, Maluge Pubuduni Imali; Wong, Elaine
2013-04-22
In this work, we present a comparative study of two just-in-time (JIT) dynamic bandwidth allocation algorithms (DBAs), designed to improve the energy-efficiency of the 10 Gbps Ethernet passive optical networks (10G-EPONs). The algorithms, termed just-in-time with varying polling cycle times (JIT) and just-in-time with fixed polling cycle times (J-FIT), are designed to achieve energy-savings when the idle time of an optical network unit (ONU) is less than the sleep-to-active transition time. This is made possible by a vertical-cavity surface-emitting laser (VCSEL) ONU that can transit into sleep or doze modes during its idle time. We evaluate the performance of the algorithms in terms of polling cycle time, power consumption, percentage of energy-savings, and average delay. The energy-efficiency of a VCSEL ONU that can transition into sleep or doze mode is compared to an always-ON distributed feedback (DFB) laser ONU. Simulation results indicate that both JIT and J-FIT DBA algorithms result in improved energy-efficiency whilst J-FIT performs better in terms of energy-savings at low network loads. The J-FIT DBA however, results in increased average delay in comparison to the JIT DBA. Nonetheless, this increase in average delay is within the acceptable range to support the quality of service (QoS) requirements of the next-generation access networks.
Directory of Open Access Journals (Sweden)
K. Srinivasa Rao
2011-01-01
Full Text Available A two node tandem communication network with dynamic bandwidth allocation (DBA having two stage direct bulk arrivals is developed and analyzed. The messages arriving to the source are packetized and stored in the buffers for forward transmission. Dynamic bandwidth allocation strategy is proposed by adjusting the transmission rate at every node just before transmission of each packet. The arrival and transmission processes at each node are characterized through compound Poisson and Poisson processes such that several of the statistical characteristics of communication networks identically matches. Using the difference - differential equations, the performance measures like the joint probability generating function of the content of two buffers, average buffer content, mean delays and throughput of nodes are derived and analyzed. It is observed that the bulk arrivals at two nodes and DBA have significant influence on performance measures. This network is much useful in Tele and Satellite communications.
Fair Adaptive Bandwidth and Subchannel Allocation in the WiMAX Uplink
Directory of Open Access Journals (Sweden)
Antoni Morell
2009-01-01
Full Text Available In some modern communication systems, as it is the case of WiMAX, it has been decided to implement Demand Assignment Multiple Access (DAMA solutions. End-users request transmission opportunities before accessing the system, which provides an efficient way to share system resources. In this paper, we briefly review the PHY and MAC layers of an OFDMA-based WiMAX system, and we propose to use a Network Utility Maximization (NUM framework to formulate the DAMA strategy foreseen in the uplink of IEEE 802.16. Utility functions are chosen to achieve fair solutions attaining different degrees of fairness and to further support the QoS requirements of the services in the system. Moreover, since the standard allocates resources in a terminal basis but each terminal may support several services, we develop a new decomposition technique, the coupled-decompositions method, that obtains the optimal service flow allocation with a small number of iterations (the improvement is significant when compared to other known solutions. Furthermore, since the PHY layer in mobile WiMAX has the means to adapt the transport capacities of the links between the Base Station (BS and the Subscriber Stations (SSs, the proposed PHY-MAC cross-layer design uses this extra degree of freedom in order to enhance the network utility.
Wei, Pei; Gu, Rentao; Ji, Yuefeng
2014-06-01
As an innovative and promising technology, network coding has been introduced to passive optical networks (PON) in recent years to support inter optical network unit (ONU) communication, yet the signaling process and dynamic bandwidth allocation (DBA) in PON with network coding (NC-PON) still need further study. Thus, we propose a joint signaling and DBA scheme for efficiently supporting differentiated services of inter ONU communication in NC-PON. In the proposed joint scheme, the signaling process lays the foundation to fulfill network coding in PON, and it can not only avoid the potential threat to downstream security in previous schemes but also be suitable for the proposed hybrid dynamic bandwidth allocation (HDBA) scheme. In HDBA, a DBA cycle is divided into two sub-cycles for applying different coding, scheduling and bandwidth allocation strategies to differentiated classes of services. Besides, as network traffic load varies, the entire upstream transmission window for all REPORT messages slides accordingly, leaving the transmission time of one or two sub-cycles to overlap with the bandwidth allocation calculation time at the optical line terminal (the OLT), so that the upstream idle time can be efficiently eliminated. Performance evaluation results validate that compared with the existing two DBA algorithms deployed in NC-PON, HDBA demonstrates the best quality of service (QoS) support in terms of delay for all classes of services, especially guarantees the end-to-end delay bound of high class services. Specifically, HDBA can eliminate queuing delay and scheduling delay of high class services, reduce those of lower class services by at least 20%, and reduce the average end-to-end delay of all services over 50%. Moreover, HDBA also achieves the maximum delay fairness between coded and uncoded lower class services, and medium delay fairness for high class services.
Optimal Bandwidth Selection in Observed-Score Kernel Equating
Häggström, Jenny; Wiberg, Marie
2014-01-01
The selection of bandwidth in kernel equating is important because it has a direct impact on the equated test scores. The aim of this article is to examine the use of double smoothing when selecting bandwidths in kernel equating and to compare double smoothing with the commonly used penalty method. This comparison was made using both an equivalent…
Optimal Bandwidth Scheduling for Resource-constrained Networks%资源约束网络的优化带宽调度
Institute of Scientific and Technical Information of China (English)
李祖欣; 王万良; 成新民
2009-01-01
In networked control systems (NCSs) with resource constraints, there is an unavoidable tradeoff between the con-trol performance and the quality of service. To address these problems, we present multi-objective programming with a set of constraints to optimize control performance and bandwidth consumption for the first time. Thanks to robust nonlinear ap-proximate function and computational cost, a feed-forward neu-ral network as optimal approximator is employed. The role of the neural network, which provides a good approximation to the optimal solution, dynamically allocates the bandwidth of each control loop so that the overall system performance is maxi-mized while bandwidth consumption is minimized. Preliminary simulation results show that the proposed optimal strategy is an effective tradeoff method between the control performance and bandwidth consumption in networked control applications.
Negotiating Socially Optimal Allocations of Resources
Endriss, U; Sadri, F; Toni, F; 10.1613/jair.1870
2011-01-01
A multiagent system may be thought of as an artificial society of autonomous software agents and we can apply concepts borrowed from welfare economics and social choice theory to assess the social welfare of such an agent society. In this paper, we study an abstract negotiation framework where agents can agree on multilateral deals to exchange bundles of indivisible resources. We then analyse how these deals affect social welfare for different instances of the basic framework and different interpretations of the concept of social welfare itself. In particular, we show how certain classes of deals are both sufficient and necessary to guarantee that a socially optimal allocation of resources will be reached eventually.
Optimal allocation of trend following strategies
Grebenkov, Denis S.; Serror, Jeremy
2015-09-01
We consider a portfolio allocation problem for trend following (TF) strategies on multiple correlated assets. Under simplifying assumptions of a Gaussian market and linear TF strategies, we derive analytical formulas for the mean and variance of the portfolio return. We construct then the optimal portfolio that maximizes risk-adjusted return by accounting for inter-asset correlations. The dynamic allocation problem for n assets is shown to be equivalent to the classical static allocation problem for n2 virtual assets that include lead-lag corrections in positions of TF strategies. The respective roles of asset auto-correlations and inter-asset correlations are investigated in depth for the two-asset case and a sector model. In contrast to the principle of diversification suggesting to treat uncorrelated assets, we show that inter-asset correlations allow one to estimate apparent trends more reliably and to adjust the TF positions more efficiently. If properly accounted for, inter-asset correlations are not deteriorative but beneficial for portfolio management that can open new profit opportunities for trend followers. These concepts are illustrated using daily returns of three highly correlated futures markets: the E-mini S&P 500, Euro Stoxx 50 index, and the US 10-year T-note futures.
MULTILAYER MICROSTRIP ANTENNA QUALITY FACTOR OPTIMIZATION FOR BANDWIDTH ENHANCEMENT
Directory of Open Access Journals (Sweden)
M.C. SRIVASTAVA
2012-12-01
Full Text Available The impedance bandwidth, one of the important characteristics of microstrip patch antennas, can be significantly improved by using a multilayer dielectric configuration. In this paper the focus is on bandwidth enhancement technique of a multilayer patch antenna for X-band applications. In order to enhance the bandwidth, antenna losses are contained by controlling those quality factors which can have a significant impact on the bandwidth for a given permittivity and thickness of the substrate. This has been achieved by conformal transformation of the multidielectric microstrip antenna. For the ease of analysis Wheelers transformation is used to map the complex permittivity of a multilayer substrate to a single layer. Method of Moments and Finite Difference Time Domain approaches are used for the computation of results.
Optimization of Gain, Impedance, and Bandwidth of Yagi-Uda Array Using Particle Swarm Optimization
Directory of Open Access Journals (Sweden)
Munish Rattan
2008-01-01
Full Text Available Particle swarm optimization (PSO is a new, high-performance evolutionary technique, which has recently been used for optimization problems in antennas and electromagnetics. It is a global optimization technique-like genetic algorithm (GA but has less computational cost compared to GA. In this paper, PSO has been used to optimize the gain, impedance, and bandwidth of Yagi-Uda array. To evaluate the performance of designs, a method of moments code NEC2 has been used. The results are comparable to those obtained using GA.
Institute of Scientific and Technical Information of China (English)
LU Yi-yi; GUO Yong; HE Chen
2009-01-01
Hybrid wavelength-division-multiplexing (WDM)/time-division-multiplexing (TDM) ethernet passive optical networks (EPONs) can achieve low per-subscriber cost and scalability to increase the number of subscribers. This paper discusses dynamic wavelength and bandwidth allocation (DWBA) algorithm in hybrid WDM/TDM EPONs. Based on the correlation structure of the variable bit rate (VBR) video traffic, we propose a quality-of-service (QoS) supported DWBA using adaptive linear traffic prediction. Wavelength and timeslot are allocated dynamically by optical line terminal (OLT) to all optical network units (ONUs) based on the bandwidth requests and the guaranteed service level agreements (SLA) of all ONUs. Mean square error of the predicted average arriv-ing rate of compound video traffic during waiting period is minimized through Wiener-Hopf equation. Simulation results show that the DWBA-adaptive-linear-prediction (DWBA-ALP) algorithm can significantly improve the QoS performances in terms of low delay and high bandwidth utilization.
Optimization of bandwidth in 60^o photonic crystal waveguide bends
DEFF Research Database (Denmark)
Xing, P. F.; Borel, Peter Ingo; Frandsen, Lars Hagedorn;
2005-01-01
A systematic scheme utilizing 2D and 3D finite-difference time-domain calculations to design 60^o photonic crystal waveguide bends is presented. The method results in an improved transmission bandwidth from 70 to 160 nm in 2D simulations, and from 50 to 100 nm in 3D simulations. The design...
Optimization of Quantum-Dot Molecular Beam Epitaxy for Broad Spectral Bandwidth Devices
Majid, M. A.
2012-12-01
The optimization of the key growth parameters for broad spectral bandwidth devices based on quantum dots is reported. A combination of atomic force microscopy, photoluminescence of test samples, and optoelectronic characterization of superluminescent diodes (SLDs) is used to optimize the growth conditions to obtain high-quality devices with large spectral bandwidth, radiative efficiency (due to a reduced defective-dot density), and thus output power. The defective-dot density is highlighted as being responsible for the degradation of device performance. An SLD device with 160 nm of bandwidth centered at 1230 nm is demonstrated.
Simplifying rules for optimal allocation of preventive care resources.
Gandjour, Afschin
2012-04-01
Given the limited resources for preventive care, policy-makers need to consider the efficiency/cost-effectiveness of preventive measures, such as drugs and vaccines, when allocating preventive care resources. However, in many settings only limited information on lifetime costs and effects of preventive measures exists. Therefore, it seems useful to provide policy-makers with some simplifying rules when allocating preventive care resources. The purpose of this article is to investigate the relevance of risk and severity of the disease to be prevented for the optimal allocation of preventive care resources. The report shows - based on a constrained optimization model - that optimal allocation of preventive care resources does, in fact, depend on both factors. Resources should be allocated to the prevention of diseases with a higher probability of occurrence or larger severity. This article also identifies situations where preventive care resources should be allocated to the prevention of less severe disease.
Institute of Scientific and Technical Information of China (English)
李征; 刘开华
2012-01-01
在物联网环境中,网络需要传输的数据和信息量急剧增加,从而造成带宽不足.为此,提出一种采用动态带宽资源分配算法的物联网远程机械控制方案,通过改变控制信号的采样速率,达到优化分配带宽资源的目的.仿真结果表明,在相同网络带宽条件下,该方案可降低重构信号的误差,并有效提高物联网系统智能分配带宽资源的能力.%According to the booming increase of network transmitted data or information and the corresponding network bandwidth insufficiency caused by the popularization of Internet of Things(IoT) key supporting technologies, such as cloud computing and data mining, this paper proposes an IoT remote machine control scheme based on a novel dynamic bandwidth resource allocation algorithm, which optimizes the bandwidth usage by scheduling the sampling rates of the control signals. Simulation results show under the same network bandwidth condition, this algorithm can reduce the reconstruction signal's error as well as enhance the intelligent bandwidth allocation capability in IoT system.
Xia, Weidong; Gan, Chaoqin; Chen, Bingqin; Xie, Weilun; Zhang, YuChao; Gou, Kaiyu
2016-09-01
In a metro-access optical network, a bandwidth-allocated algorithm is proposed for traffic-orientated multisubsystem-based virtual passive optical network (MS-VPON) that can implement the syncretism of multiple systems such as time division multiplexing-PON (TDM-PON), wavelength division multiplexing-PON (WDM-PON), and orthogonal frequency division multiplexing-PON (OFDM-PON). VPONs are constructed based on traffic and different VPONs are separated by different types of traffic. The bandwidth-allocated algorithm is modeled with a matrix theory to determine which VPON can be admitted and then a bandwidth is assigned to these VPONs. With the algorithm, the network value can be maximized. Two cases are investigated to demonstrate the effectiveness of the proposed algorithm in the bandwidth-utilized ratio and VPONs' admission probability.
Adaptive Slot Allocation And Bandwidth Sharing For Prioritized Handoff Calls In Mobile Netwoks
Malathy, S; Murugan, K; Lokesh, S
2010-01-01
Mobility management and bandwidth management are two major research issues in a cellular mobile network. Mobility management consists of two basic components: location management and handoff management. To Provide QoS to the users Handoff is a key element in wireless cellular networks. It is often initiated either by crossing a cell boundary or by deterioration in the quality of signal in the current channel. In this paper, a new admission control policy for cellular mobile network is being proposed. Two important QoS parameter in cellular networks are Call Dropping Probability (CDP) and Handoff Dropping Probability (HDP). CDP represents the probability that a call is dropped due to a handoff failure. HDP represents the probability of a handoff failure due to insufficient available resources in the target cell. Most of the algorithms try to limit the HDP to some target maximum but not CDP. In this paper, we show that when HDP is controlled, the CDP is also controlled to a minimum extent while maintaining lowe...
Energy-Efficient Bandwidth Allocation for Multiuser Scalable Video Streaming over WLAN
Directory of Open Access Journals (Sweden)
Lafruit Gauthier
2008-01-01
Full Text Available Abstract We consider the problem of packet scheduling for the transmission of multiple video streams over a wireless local area network (WLAN. A cross-layer optimization framework is proposed to minimize the wireless transceiver energy consumption while meeting the user required visual quality constraints. The framework relies on the IEEE 802.11 standard and on the embedded bitstream structure of the scalable video coding scheme. It integrates an application-level video quality metric as QoS constraint (instead of a communication layer quality metric with energy consumption optimization through link layer scaling and sleeping. Both energy minimization and min-max energy optimization strategies are discussed. Simulation results demonstrate significant energy gains compared to the state-of-the-art approaches.
ON OPTIMAL LOCAL BUFFER ALLOCATION IN FLEXIBLE MANUFACTURING SYSTEMS
Institute of Scientific and Technical Information of China (English)
1998-01-01
An optimal design problem of local buffer allocation in the FMS is discussed in order to maximize a reward earned from processed jobs at all workstations. Structural properties of the optimal design problem are analyzed for the model with two job routing policies. Based on these properties, approaches to optimal solutions are given.
Objective function of cost in optimal tolerance allocation
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
An objective function model is proposed for cost in optimizing and allocating tolerance with consideration of manufacturing conditions. With the fuzzy comprehensive evaluation method, a manufacturing difficulty coefficient is derived, which takes into account of several factors affecting the manufacturing cost, including the forming means of the blank, size, machining surface features, operator's skills and machinability of materials.The coefficient is then converted into a weight factor used in the inversed square model representing the relationship between the cost and tolerance, and, hence, an objective function for cost is established in optimizing and allocating tolerance. The higher is the manufacturing difficulty coefficient, the higher is the relative manufacturing cost and the higher is the weight factor of the tolerance allocation, which indicates the increase of the tolerance's effects on the total manufacturing cost and, therefore, a larger tolerance should be allocated. The computer-aided tolerance allocation utilizing this model makes it more convenient, accurate and practicable.
Power and Efficiency Optimized in Traveling-Wave Tubes Over a Broad Frequency Bandwidth
Wilson, Jeffrey D.
2001-01-01
A traveling-wave tube (TWT) is an electron beam device that is used to amplify electromagnetic communication waves at radio and microwave frequencies. TWT's are critical components in deep space probes, communication satellites, and high-power radar systems. Power conversion efficiency is of paramount importance for TWT's employed in deep space probes and communication satellites. A previous effort was very successful in increasing efficiency and power at a single frequency (ref. 1). Such an algorithm is sufficient for narrow bandwidth designs, but for optimal designs in applications that require high radiofrequency power over a wide bandwidth, such as high-density communications or high-resolution radar, the variation of the circuit response with respect to frequency must be considered. This work at the NASA Glenn Research Center is the first to develop techniques for optimizing TWT efficiency and output power over a broad frequency bandwidth (ref. 2). The techniques are based on simulated annealing, which has the advantage over conventional optimization techniques in that it enables the best possible solution to be obtained (ref. 3). Two new broadband simulated annealing algorithms were developed that optimize (1) minimum saturated power efficiency over a frequency bandwidth and (2) simultaneous bandwidth and minimum power efficiency over the frequency band with constant input power. The algorithms were incorporated into the NASA coupled-cavity TWT computer model (ref. 4) and used to design optimal phase velocity tapers using the 59- to 64-GHz Hughes 961HA coupled-cavity TWT as a baseline model. In comparison to the baseline design, the computational results of the first broad-band design algorithm show an improvement of 73.9 percent in minimum saturated efficiency (see the top graph). The second broadband design algorithm (see the bottom graph) improves minimum radiofrequency efficiency with constant input power drive by a factor of 2.7 at the high band edge (64
Zhang, Chongfu; Xiao, Nengwu; Chen, Chen; Yuan, Weicheng; Qiu, Kun
2016-02-01
We propose an energy-efficient orthogonal frequency division multiplexing-based passive optical network (OFDM-PON) using adaptive sleep-mode control and dynamic bandwidth allocation. In this scheme, a bidirectional-centralized algorithm named the receiver and transmitter accurate sleep control and dynamic bandwidth allocation (RTASC-DBA), which has an overall bandwidth scheduling policy, is employed to enhance the energy efficiency of the OFDM-PON. The RTASC-DBA algorithm is used in an optical line terminal (OLT) to control the sleep mode of an optical network unit (ONU) sleep and guarantee the quality of service of different services of the OFDM-PON. The obtained results show that, by using the proposed scheme, the average power consumption of the ONU is reduced by ˜40% when the normalized ONU load is less than 80%, compared with the average power consumption without using the proposed scheme.
Delay-Constrained Admission and Bandwidth Allocation for Long-Reach EPON
Directory of Open Access Journals (Sweden)
Burak Kantarci
2012-05-01
Full Text Available Next generation Passive Optical Network (PONtechnology has been evolving to consolidate the metro andaccess networks in order to offer enhanced capacity, highsplit ratio and reduced deployment cost per subscriber.However, transmission of the signals to long distances up to100km leads to increased propagation delay whereas highsplit ratio may lead to long cycle times resulting in largequeue occupancies and long packet delays. In this article, wepresent a delay-constrained admission control mechanismand adapt this scheme to our previously proposed bandwidthallocation technique, namely Periodic GATE Optimization(PGO. We call this new scheme Delay-Constrained PeriodicGATE Optimization (DC-PGO. DC-PGO is designed to runfor multiple service classes as it inherits the advantages ofPGO by periodically building and solving an ILP formulationat the OLT in order to obtain the appropriate creditvalues for the overloaded ONUs. At the ONU side, DCPGOruns an admission control scheme before pushing thearriving packets in the sub-queues. The admission controlscheme uses statistical information consisting of the localdata at the ONU and the previously received GATE messagesfrom the OLT. Through simulations, we show that DC-PGOenhances the performance of multi-threaded polling in longreachEthernet PON when packets of differentiated serviceclasses arrive with pre-specified delay requirements.
A heuristic to bandwidth allocation and sales limit setting for Internet service providers
You, Peng Sheng; Hsieh, Yi-Chih; Ikuta, Seizo
2012-11-01
When requesting on-line, many subscribers have experienced the situation in which their on-line requests are denied or their connection speeds are far below their contracted speed limits. This bad customer experience may result from the situation in which Internet service providers (ISPs) accept customers' subscriptions without setting sales limits. As subscribers are potential on-line users, controlling the number of subscribers can be considered as an approach to overcome this problem. The goal of this article is to develop decisions to maximise revenues of ISPs while guaranteeing the expected service quality for distinct service classes. The developed model was a resource constrained nonlinear integer problem, and a heuristic approach was provided to acquire a near-optimal solution. Limited numerical results showed that the proposed heuristic approach can solve this problem efficiently.
USMC Logistics Resource Allocation Optimization Tool
2015-12-01
Logistics, Supply Chain Management, Modeling and Optimization, Linear Program. 15. NUMBER OF PAGES 83 16. PRICE CODE 17. SECURITY CLASSIFICATION... Algebraic Modeling System GR Grounding Rod GUI Graphical User Interface HADR Humanitarian Assistance/Disaster Relief HL Headlight JHSV Joint High...many optimization methods which are applicable to a logistical transportation problem is elusive at best. The method presented through MARPOM is
Optimal Sensor Allocation for Fault Detection and Isolation
Azam, Mohammad; Pattipati, Krishna; Patterson-Hine, Ann
2004-01-01
Automatic fault diagnostic schemes rely on various types of sensors (e.g., temperature, pressure, vibration, etc) to measure the system parameters. Efficacy of a diagnostic scheme is largely dependent on the amount and quality of information available from these sensors. The reliability of sensors, as well as the weight, volume, power, and cost constraints, often makes it impractical to monitor a large number of system parameters. An optimized sensor allocation that maximizes the fault diagnosibility, subject to specified weight, volume, power, and cost constraints is required. Use of optimal sensor allocation strategies during the design phase can ensure better diagnostics at a reduced cost for a system incorporating a high degree of built-in testing. In this paper, we propose an approach that employs multiple fault diagnosis (MFD) and optimization techniques for optimal sensor placement for fault detection and isolation (FDI) in complex systems. Keywords: sensor allocation, multiple fault diagnosis, Lagrangian relaxation, approximate belief revision, multidimensional knapsack problem.
Country- and age-specific optimal allocation of dengue vaccines.
Ndeffo Mbah, Martial L; Durham, David P; Medlock, Jan; Galvani, Alison P
2014-02-07
Several dengue vaccines are under development, and some are expected to become available imminently. Concomitant with the anticipated release of these vaccines, vaccine allocation strategies for dengue-endemic countries in Southeast Asia and Latin America are currently under development. We developed a model of dengue transmission that incorporates the age-specific distributions of dengue burden corresponding to those in Thailand and Brazil, respectively, to determine vaccine allocations that minimize the incidence of dengue hemorrhagic fever, taking into account limited availability of vaccine doses in the initial phase of production. We showed that optimal vaccine allocation strategies vary significantly with the demographic burden of dengue hemorrhagic fever. Consequently, the strategy that is optimal for one country may be sub-optimal for another country. More specifically, we showed that, during the first years following introduction of a dengue vaccine, it is optimal to target children for dengue mass vaccination in Thailand, whereas young adults should be targeted in Brazil.
Optimal performance of networked control systems with bandwidth and coding constraints.
Zhan, Xi-Sheng; Sun, Xin-xiang; Li, Tao; Wu, Jie; Jiang, Xiao-Wei
2015-11-01
The optimal tracking performance of multiple-input multiple-output (MIMO) discrete-time networked control systems with bandwidth and coding constraints is studied in this paper. The optimal tracking performance of networked control system is obtained by using spectral factorization technique and partial fraction. The obtained results demonstrate that the optimal performance is influenced by the directions and locations of the nonminimum phase zeros and unstable poles of the given plant. In addition to that, the characters of the reference signal, encoding, the bandwidth and additive white Gaussian noise (AWGN) of the communication channel are also closely influenced by the optimal tracking performance. Some typical examples are given to illustrate the theoretical results.
Bandwidth optimization of a Planar Inverted-F Antenna using binary and real coded genetic algorithms
Institute of Scientific and Technical Information of China (English)
AMEERUDDEN Mohammad Riyad; RUGHOOPUTH Harry C S
2009-01-01
With the exponential development of mobile communications and the miniaturization of radio frequency transceivers, the need for small and low profile antennas at mobile frequencies is constantly growing. Therefore, new antennas should be developed to provide larger bandwidth and at the same time small dimensions. Although the gain in bandwidth performances of an antenna are directly related to its dimensions in relation to the wavelength, the aim is to keep the overall size of the antenna constant and from there, find the geometry and structure that give the best performance. The design and bandwidth optimization of a Planar Inverted-F Antenna (PIFA) were introduced in order to achieve a larger bandwidth in the 2 GHz band, using two optimization techniques based upon genetic algorithms (GA), namely the Binary Coded GA (BCGA) and Real-Coded GA (RCGA). During the optimization process, the different PIFA models were evaluated using the finite-difference time domain (FDTD) method-a technique belonging to the general class of differential time domain numerical modeling methods.
Institute of Scientific and Technical Information of China (English)
2013-01-01
基于对等网(P2P)技术的视频流媒体系统以其较低的服务器开销和良好的可扩展性被广泛应用。但由于在这类系统中普遍存在节点的资源及视频播放位置的异构性，使得节点负载不均衡的问题极易发生，进而严重影响到节点的视频播放质量。该文重点研究面向节点负载均衡的节点带宽请求分配策略，将服务请求节点竞争服务提供节点带宽的行为建模为一个非协作博弈，通过寻求该博弈问题的 Nash 均衡解的方法确定优化的带宽请求分配(GBRA)策略。通过和典型的带宽请求分配策略进行实验对比，数值结果表明该文提出的GBRA 策略能有效改善P2P流媒体网络节点负载不均的问题并降低节点获取所需视频数据的平均延迟。%Due to the merits of lower bandwidth consumption at streaming server and higher scalability, P2P streaming systems are widely adopted and deployed. However, the heterogeneity of bandwidth resource and playback position at peers may easily lead to load unbalancing problem. This may severely deteriorate video playback quality at peers. This paper focuses on the issue of bandwidth request allocation, aiming at substantially balancing the load at the peers in P2P streaming network. The problem of contending service from multiple neighboring peers is modeled as a non-cooperative game, and the optimal bandwidth request allocation policy, called Game based Bandwidth Request Allocation (GBRA), is obtained through searching the Nash equilibrium of this game. Numerical results show that the proposed policy can effectively improve the load balancing of the P2P streaming networks and decrease the latency of streaming data retrieval at peers when compared with the classical bandwidth request allocation policies.
Optimization of Single-Sensor Two-State Hot-Wire Anemometer Transmission Bandwidth.
Ligęza, Paweł
2008-10-28
Hot-wire anemometric measurements of non-isothermal flows require the use of thermal compensation or correction circuitry. One possible solution is a two-state hot-wire anemometer that uses the cyclically changing heating level of a single sensor. The area in which flow velocity and fluid temperature can be measured is limited by the dimensions of the sensor's active element. The system is designed to measure flows characterized by high velocity and temperature gradients, although its transmission bandwidth is very limited. In this study, we propose a method to optimize the two-state hot-wire anemometer transmission bandwidth. The method is based on the use of a specialized constanttemperature system together with variable dynamic parameters. It is also based on a suitable measurement cycle paradigm. Analysis of the method was undertaken using model testing. Our results reveal a possible significant broadening of the two-state hot-wire anemometer's transmission bandwidth.
Institute of Scientific and Technical Information of China (English)
XIONGHongkai; YUSongyu; YEWei
2003-01-01
Because real-time compression and high-speed digital processing circuitry are crucial for digital high definition television (HDTV) coding, parallel processing has become a feasible scheme in most applications as yet. This paper presents a novel bit-allocation strategy for an HDTV encoder system with parallel architecture, in which the original HDTV-picture is divided into six hor-izontal sub-pictures. It is shown that the MPEG-2 Test Model 5 (TMS) rate control scheme would not only give rise to non-consistent sub-pictures visual quality in a com-posite HDTV frame, but also make the coding quality de-grade abruptly and the buffer underfiow at scene changes.How to allocate bit-rates among sub-pictures becomes a great challenge in literatures. The proposed strategy is dedicated to a hierarchical joint optimized bit-allocation with sub-pictures' average complexity and average bits measure, and moreover, capable of alleviating serious pic-ture quality inconsistence at scene changes. The optimized bit-allocation and its complementary rate adaptive proce-dures are formulated and described. In the paper, the pro-posed strategy is compared with the independent coding,in which each sub-picture sequence is assigned the same proportion of the channel bandwidth. Experimental re-suits demonstrate the effectiveness of the proposed scheme not only alleviates the boundary effect but also promises the sub-pictures quality consistency.
Resource Allocation in Public Cluster with Extended Optimization Algorithm
Akbar, Z.; Handoko, L. T.
2007-01-01
We introduce an optimization algorithm for resource allocation in the LIPI Public Cluster to optimize its usage according to incoming requests from users. The tool is an extended and modified genetic algorithm developed to match specific natures of public cluster. We present a detail analysis of optimization, and compare the results with the exact calculation. We show that it would be very useful and could realize an automatic decision making system for public clusters.
Optimizing Earth Allocation for Rock-Fill Dam Construction
Institute of Scientific and Technical Information of China (English)
ZHONG Denghua; HU Chengshun; ZHANG Jing
2005-01-01
An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method.
Optimization of reliability allocation strategies through use of genetic algorithms
Energy Technology Data Exchange (ETDEWEB)
Campbell, J.E.; Painton, L.A.
1996-08-01
This paper examines a novel optimization technique called genetic algorithms and its application to the optimization of reliability allocation strategies. Reliability allocation should occur in the initial stages of design, when the objective is to determine an optimal breakdown or allocation of reliability to certain components or subassemblies in order to meet system specifications. The reliability allocation optimization is applied to the design of a cluster tool, a highly complex piece of equipment used in semiconductor manufacturing. The problem formulation is presented, including decision variables, performance measures and constraints, and genetic algorithm parameters. Piecewise ``effort curves`` specifying the amount of effort required to achieve a certain level of reliability for each component of subassembly are defined. The genetic algorithm evolves or picks those combinations of ``effort`` or reliability levels for each component which optimize the objective of maximizing Mean Time Between Failures while staying within a budget. The results show that the genetic algorithm is very efficient at finding a set of robust solutions. A time history of the optimization is presented, along with histograms or the solution space fitness, MTBF, and cost for comparative purposes.
Solving the optimal attention allocation problem in manual control
Kleinman, D. L.
1976-01-01
Within the context of the optimal control model of human response, analytic expressions for the gradients of closed-loop performance metrics with respect to human operator attention allocation are derived. These derivatives serve as the basis for a gradient algorithm that determines the optimal attention that a human should allocate among several display indicators in a steady-state manual control task. Application of the human modeling techniques are made to study the hover control task for a CH-46 VTOL flight tested by NASA.
OPTIMAL RESOURCE ALLOCATION IN GENERAL COURNOTCOMPETITIVE EQUILIBRIUM
Ervik, Inger Sommerfelt; Soegaard, Christian
2013-01-01
Conventional economic theory stipulates that output in Cournot competition is too low relative to that which is attained in perfect competition. We revisit this result in a General Cournot-competitive Equilibrium model with two industries that di er only in terms of productivity. We show that in general equilibrium, the more ecient industry produces too little and the less ecient industry produces too much compared to an optimal scenario with perfect competition.
A Theoretical Assessment on Optimal Asset Allocations in Insurance Industry
Directory of Open Access Journals (Sweden)
Bilel Jarraya
2013-10-01
Full Text Available In recent years the financial markets known a rapid development and become more and more complex. So, many regulatory requirements, focused on banks as well as insurance sector, have been developed. These regulatory are concentrated essentially on business risk control and required capital to cover risks. These requirements have influenced the asset allocation issue in insurance industry. These requirements have influenced the asset allocation issue in insurance industry. This section is interested by this issue. In first time it highlights some research works in this issue. Then we will investigate the relation between Solvency and optimal asset allocation. Finally we will explore the principal used methods in modeling asset and in choosing the optimal portfolio composition.
Rawat, Banmali
2000-01-01
The multimode fiber bandwidth enhancement techniques to meet the Gigabit Ethernet standards for local area networks (LAN) of the Kennedy Space Center and other NASA centers have been discussed. Connector with lateral offset coupling between single mode launch fiber cable and the multimode fiber cable has been thoroughly investigated. An optimization of connector position offset for 8 km long optical fiber link at 1300 nm with 9 micrometer diameter single mode fiber (SMF) and 50 micrometer diameter multimode fiber (MMF) coupling has been obtained. The optimization is done in terms of bandwidth, eye-pattern, and bit pattern measurements. It is simpler, is a highly practical approach and is cheaper as no additional cost to manufacture the offset type of connectors is involved.
MVB非周期信息的通信带宽分配策略研究%Study on bandwidth allocation strategy of MVB aperiodic communication
Institute of Scientific and Technical Information of China (English)
曾秋芬; 陈特放; 刘毅斌
2011-01-01
Both periodic and aperiodic messages are transmitted on multifunction vehicle bus (MVB). The transmission of periodic messages must comply with the strict real-time requirements and aperiodic messages are always made a random arrival. Bandwidth availability of MVB can be improved if the bandwidth is distributed reasonably. On analyzing the characteristics of every type of messages, two bandwidth allocation strategies of MVB aperiodic communication are proposed. In combination with the scheduling principles of aperiodic messages, the two bandwidth allocation strategies are researched and compared; the application scope of everystrategy is given.%多功能车辆总线MVB需要传送具有高实时性要求的周期信息和随机到达的非周期信息,合理分配相应信息带宽可以提高整个网络的通信带宽利用率.在分析各类信息特点的基础上,提出了非周期信息通信的两种带宽分配策略.结合MVB非周期信息的调度方法,对两种策略进行了分析研究和性能比较,给出了各种策略的适用范围.
optimization of water resources allocation in semi-arid region
African Journals Online (AJOL)
Eng Obi Ibeje
engineeribeje@yahoo.com,. 2Department of ... This study is aimed at achieving optimal water resources allocation in the semi-arid areas using Dadin-Nkowa dam in Gombe State as a case study. .... China applied this methodology in solving.
Winter wheat optimizes allocation in response to carbon limitation
Huang, Jianbei; Hammerbacher, Almuth; Trumbore, Susan; Hartmann, Henrik
2016-04-01
• Plant photosynthesis is not carbon-saturated at current atmospheric CO2 concentration ([CO2]) thus carbon allocation priority is of critical importance in determining plant response to environmental changes, including increasing [CO2]. • We quantified the percentage of daytime net assimilation (A) allocated to whole-plant nighttime respiration (R) and structural growth (SG), nonstructural carbohydrates (NSC) and secondary metabolites (SMs) during winter wheat (Triticum aestivum) vegetative growth (over 4 weeks) at glacial, ambient, and elevated [CO2] (170, 390 and 680 ppm). • We found that R/A remained relatively constant (11-14%) across [CO2] treatments, whereas plants allocated less C to growth and more C to export at low [CO2] than elevated [CO2]; low [CO2] grown plants tended to invest overall less C into NSC and SMs than to SG due to reduced NSC availability; while leaf SMs/NSC was greater at 170 ppm than at 680 ppm [CO2] this was the opposite for root SMs/NSC; biomass, especially NSC, were preferentially allocated to leaves instead of stems and roots, likely to relieve C limitation induced by low [CO2]. • We conclude that C limitation may force plants to reduce C allocation to long-term survival in order to secure short-term survival. Furthermore, they optimized allocation of the available resource by concentrating biomass and storage to those tissues responsible for assimilation.
Optimizing investment fund allocation using vehicle routing problem framework
Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita
2014-07-01
The objective of investment is to maximize total returns or minimize total risks. To determine the optimum order of investment, vehicle routing problem method is used. The method which is widely used in the field of resource distribution shares almost similar characteristics with the problem of investment fund allocation. In this paper we describe and elucidate the concept of using vehicle routing problem framework in optimizing the allocation of investment fund. To better illustrate these similarities, sectorial data from FTSE Bursa Malaysia is used. Results show that different values of utility for risk-averse investors generate the same investment routes.
Cross-Layer Optimal Rate Allocation for Heterogeneous Wireless Multicast
Directory of Open Access Journals (Sweden)
Amr Mohamed
2009-01-01
Full Text Available Heterogeneous multicast is an efficient communication scheme especially for multimedia applications running over multihop networks. The term heterogeneous refers to the phenomenon when multicast receivers in the same session require service at different rates commensurate with their capabilities. In this paper, we address the problem of resource allocation for a set of heterogeneous multicast sessions over multihop wireless networks. We propose an iterative algorithm that achieves the optimal rates for a set of heterogeneous multicast sessions such that the aggregate utility for all sessions is maximized. We present the formulation of the multicast resource allocation problem as a nonlinear optimization model and highlight the cross-layer framework that can solve this problem in a distributed ad hoc network environment with asynchronous computations. Our simulations show that the algorithm achieves optimal resource utilization, guarantees fairness among multicast sessions, provides flexibility in allocating rates over different parts of the multicast sessions, and adapts to changing conditions such as dynamic channel capacity and node mobility. Our results show that the proposed algorithm not only provides flexibility in allocating resources across multicast sessions, but also increases the aggregate system utility and improves the overall system throughput by almost 30% compared to homogeneous multicast.
Multiple-Agent Task Allocation Algorithm Utilizing Ant Colony Optimization
Directory of Open Access Journals (Sweden)
Kai Zhao
2013-11-01
Full Text Available Task allocation in multiple agent system has been widely applied many application fields, such as unmanned aerial vehicle, multi-robot system and manufacturing system et al. Therefore, it becomes one of the hot topics in distributed artificial intelligence research field for several years. Therefore, in this paper, we propose a novel task allocation algorithm in multiple agent systems utilizing ant colony optimization. Firstly, the basic structure of agent organization is described, which include context-aware module, information processing module, the executing module, decision-making and intelligent control module, knowledge base and task table. Based the above agent structure, these module utilize the knowledge in the external environment to process the information in agent communicating. Secondly, we point out that task allocation process in multiple agent systems can be implement by creating the space to the mapping of the multi-agent organization. Thirdly, a modified multiple agent system oriented ant colony optimization algorithm is given, which contain pre-processing steps and the task allocation results are obtained by executing the trust region sqp algorithm in local solver. Finally, performance evaluation is conducted by experiments comparing with Random strategy and Instant optimal strategy, and very positive results are obtained
Optimal Constrained Resource Allocation Strategies under Low Risk Circumstances
Andreica, Mugurel Ionut; Visan, Costel
2009-01-01
In this paper we consider multiple constrained resource allocation problems, where the constraints can be specified by formulating activity dependency restrictions or by using game-theoretic models. All the problems are focused on generic resources, with a few exceptions which consider financial resources in particular. The problems consider low-risk circumstances and the values of the uncertain variables which are used by the algorithms are the expected values of the variables. For each of the considered problems we propose novel algorithmic solutions for computing optimal resource allocation strategies. The presented solutions are optimal or near-optimal from the perspective of their time complexity. The considered problems have applications in a broad range of domains, like workflow scheduling in industry (e.g. in the mining and metallurgical industry) or the financial sector, motion planning, facility location and data transfer or job scheduling and resource management in Grids, clouds or other distribute...
Directory of Open Access Journals (Sweden)
Andrew J Shattock
2016-02-01
Full Text Available Introduction: International investment in the response to HIV and AIDS has plateaued and its future level is uncertain. With many countries committed to ending the epidemic, it is essential to allocate available resources efficiently over different response periods to maximize impact. The objective of this study is to propose a technique to determine the optimal allocation of funds over time across a set of HIV programmes to achieve desirable health outcomes. Methods: We developed a technique to determine the optimal time-varying allocation of funds (1 when the future annual HIV budget is pre-defined and (2 when the total budget over a period is pre-defined, but the year-on-year budget is to be optimally determined. We use this methodology with Optima, an HIV transmission model that uses non-linear relationships between programme spending and associated programmatic outcomes to quantify the expected epidemiological impact of spending. We apply these methods to data collected from Zambia to determine the optimal distribution of resources to fund the right programmes, for the right people, at the right time. Results and discussion: Considering realistic implementation and ethical constraints, we estimate that the optimal time-varying redistribution of the 2014 Zambian HIV budget between 2015 and 2025 will lead to a 7.6% (7.3% to 7.8% decrease in cumulative new HIV infections compared with a baseline scenario where programme allocations remain at 2014 levels. This compares to a 5.1% (4.6% to 5.6% reduction in new infections using an optimal allocation with constant programme spending that recommends unrealistic programmatic changes. Contrasting priorities for programme funding arise when assessing outcomes for a five-year funding period over 5-, 10- and 20-year time horizons. Conclusions: Countries increasingly face the need to do more with the resources available. The methodology presented here can aid decision-makers in planning as to when to
Directory of Open Access Journals (Sweden)
G. Chandra Sekhar
2013-01-01
Full Text Available In this paper, authors presented a price maximization scheme for optimal orthogonal frequency division for multiple access (OFDMA subcarrier allocation for wireless video unicast/multicast scenarios. They formulate a pricing based video utility function for H.264 based wireless scalable video streaming, thereby achieving a trade-off between price and QoS fairness. These parametric models for scalable video rate and quality characterization are derived from the standard JSVM reference codec for the SVC extension of the H.264/AVC, and hence are directly applicable in practical wireless scenarios. With the aid of these models, they proposed auction based framework for revenue maximization of the transmitted video streams in the unicast and multicast 4G scenario. A closed form expression is derived for the optimal scalable video quantization step-size subject to the constraints of the unicast/multicast users in 4G wireless systems. This yields the optimal OFDMA subcarrier allocation for multi-user scalable video multiplexing. The proposed scheme is cognizant of the user modulation and code rate, and is hence amenable to adaptive modulation and coding (AMC feature of 4G wireless networks. Further, they also consider a framework for optimal power allocation based on a novel revenue maximization scheme in OFDMA based wireless broadband 4G systems employing auction bidding models. This is formulated as a constrained convex optimization problem towards sum video utility maximization. We observe that as the demand for a video stream increases in broadcast/multicast scenarios, higher power is allocated to the corresponding video stream leading to a gain in the overall revenue/utility. We simulate a standard WiMAX based 4G video transmission scenario to validate the performance of the proposed optimal 4G scalable video resource allocation schemes. Simulations illustrate that the proposed optimal bandwidth and power allocation schemes result in a significant
DEFF Research Database (Denmark)
Jørgensen, Mette Marie; Petersen, Sidsel Rübner; Laurila, Marko;
2012-01-01
. Large preform tolerances are compensated during the fiber draw resulting in ultra low NA fibers with very large cores. In this paper, design optimization of the SM bandwidth of the DMF rod fiber is presented. Analysis of band gap properties results in a fourfold increase of the SM bandwidth compared......High-power fiber amplifiers for pulsed applications require large mode area (LMA) fibers having high pump absorption and near diffraction limited output. This improves the limiting factor of nonlinear effects, while maintaining good beam quality. Photonic crystal fibers allow realization of short...... to previous results, achieved by utilizing the first band of cladding modes. This covers of a large fraction of the Yb emission band, where wavelengths of 1030 nm and 1064 nm can be included....
CPU and memory allocation optimization using fuzzy logic
Zalevsky, Zeev; Gur, Eran; Mendlovic, David
2002-12-01
The allocation of CPU time and memory resources, are well known problems in organizations with a large number of users, and a single mainframe. Usually the amount of resources given to a single user is based on its own statistics, not on the entire statistics of the organization therefore patterns are not well identified and the allocation system is prodigal. In this work the authors suggest a fuzzy logic based algorithm to optimize the CPU and memory distribution between the users based on the history of the users. The algorithm works separately on heavy users and light users since they have different patterns to be observed. The result is a set of rules, generated by the fuzzy logic inference engine that will allow the system to use its computing ability in an optimized manner. Test results on data taken from the Faculty of Engineering in Tel Aviv University, demonstrate the abilities of the new algorithm.
Optimal and Fair Resource Allocation for Multiuser Wireless Multimedia Transmissions
Directory of Open Access Journals (Sweden)
Guan Zhangyu
2009-01-01
Full Text Available This paper presents an optimal and fair strategy for multiuser multimedia radio resource allocation (RRA based on coopetition, which suggests a judicious mixture of competition and cooperation. We formulate the co-opetition strategy as sum utility maximization at constraints from both Physical (PHY and Application (APP layers. We show that the maximization can be solved efficiently employing the well-defined Layering as Optimization Decomposition (LOD method. Moreover, the coopetition strategy is applied to power allocation among multiple video users, and evaluated through comparing with existing- competition based strategy. Numerical results indicate that, the co-opetition strategy adapts the best to the changes of network conditions, participating users, and so forth. It is also shown that the coopetition can lead to an improved number of satisfied users, and in the meanwhile provide more flexible tradeoff between system efficiency and fairness among users.
Optimization of Single-Sensor Two-State Hot-Wire Anemometer Transmission Bandwidth
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PaweÃ…Â‚ LigÃ„Â™za
2008-10-01
Full Text Available Hot-wire anemometric measurements of non-isothermal flows require the use of thermal compensation or correction circuitry. One possible solution is a two-state hot-wire anemometer that uses the cyclically changing heating level of a single sensor. The area in which flow velocity and fluid temperature can be measured is limited by the dimensions of the sensorÃ¢Â€Â™s active element. The system is designed to measure flows characterized by high velocity and temperature gradients, although its transmission bandwidth is very limited. In this study, we propose a method to optimize the two-state hot-wire anemometer transmission bandwidth. The method is based on the use of a specialized constanttemperature system together with variable dynamic parameters. It is also based on a suitable measurement cycle paradigm. Analysis of the method was undertaken using model testing. Our results reveal a possible significant broadening of the two-state hot-wire anemometer's transmission bandwidth.
DEFF Research Database (Denmark)
Kristensen, Martin; Borel, Peter Ingo; Frandsen, Lars Hagedorn;
2005-01-01
Topology optimization was used to design a planar photonic crystal waveguide 60o bend leading to a record-breaking transmission bandwidth of more than 200nm. The experimental results agree well with 3D finite-difference-time-domain simulations.......Topology optimization was used to design a planar photonic crystal waveguide 60o bend leading to a record-breaking transmission bandwidth of more than 200nm. The experimental results agree well with 3D finite-difference-time-domain simulations....
Optimal Energy Allocation for Wireless Communications with Energy Harvesting Constraints
Ho, Chin Keong
2011-01-01
We consider the use of energy harvesters, in place of conventional batteries with fixed energy storage, for point-to-point wireless communications. In addition to the challenge of transmitting in a channel with time selective fading, energy harvesters provide a perpetual but unreliable energy source. In this paper, we consider the problem of energy allocation over a finite horizon, taking into account channel conditions and energy sources that are time varying, so as to maximize the throughput. Two types of side information (SI) on the channel conditions and harvested energy are assumed to be available: causal SI (of the past and present slots) and full SI (of the past, present and future slots). We obtain structural results for the optimal energy allocation, via the use of dynamic programming and convex optimization techniques. In particular, if unlimited energy can be stored in the battery with harvested energy and full SI is available, we prove the optimality of a water-filling energy allocation solution w...
A Fair Bandwidth Allocation Mechanism with Preference to Short Flows%一种短流优先的公平带宽分配机制
Institute of Scientific and Technical Information of China (English)
张鹤颖; 蒋杰; 窦文华
2007-01-01
提出一种短流优先的公平带宽分配机制FPIP(fair PIP).通过区别处理短流和长流的报文,FPIP能够将带宽优先分配给短流,然后将剩余的带宽在长流之间公平分配.此外,FPIP采用主动队列管理机制AQM(active queue management)检测拥塞并控制队列长度.仿真结果表明,FPIP在保证公平性、控制队列长度、减小Web流的响应时间等方面具有良好的性能.%This paper proposes a fair bandwidth allocation mechanism FPIP(fair PIP). Dealing differently with the packets of long flows and short flows at routers,the mechanism can preferentially allocate the bandwidth of the router to short flows and allocate the remaining among the competing long flows. Furthermore,it can keep the queue length of the router at a reference value using a well-designed active queue management AQM(active queue management) algorithm. The simulation results show that this new mechanism can outperform CSFQ(core-stateless fair queueing) in terms of fairness,queue length and the response time of Web flows.
Optimal Allocation of Water Resources Based on Water Supply Security
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Jianhua Wang
2016-06-01
Full Text Available Under the combined impacts of climate change and human activities, a series of water issues, such as water shortages, have arisen all over the world. According to current studies in Science and Nature, water security has become a frontier critical topic. Water supply security (WSS, which is the state of water resources and their capacity and their capacity to meet the demand of water users by water supply systems, is an important part of water security. Currently, WSS is affected by the amount of water resources, water supply projects, water quality and water management. Water shortages have also led to water supply insecurity. WSS is now evaluated based on the balance of the supply and demand under a single water resources condition without considering the dynamics of the varying conditions of water resources each year. This paper developed an optimal allocation model for water resources that can realize the optimal allocation of regional water resources and comprehensively evaluate WSS. The objective of this model is to minimize the duration of water shortages in the long term, as characterized by the Water Supply Security Index (WSSI, which is the assessment value of WSS, a larger WSSI value indicates better results. In addition, the simulation results of the model can determine the change process and dynamic evolution of the WSS. Quanzhou, a city in China with serious water shortage problems, was selected as a case study. The allocation results of the current year and target year of planning demonstrated that the level of regional comprehensive WSS was significantly influenced by the capacity of water supply projects and the conditions of the natural water resources. The varying conditions of the water resources allocation results in the same year demonstrated that the allocation results and WSSI were significantly affected by reductions in precipitation, decreases in the water yield coefficient, and changes in the underlying surface.
Dynamic optimization model for allocating medical resources in epidemic controlling
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Ming Liu
2013-03-01
Full Text Available Purpose: The model proposed in this paper addresses a dynamic optimization model for allocating medical resources in epidemic controlling.Design/methodology/approach: In this work, a three-level and dynamic linear programming model for allocating medical resources based on epidemic diffusion model is proposed. The epidemic diffusion model is used to construct the forecasting mechanism for dynamic demand of medical resources. Heuristic algorithm coupled with MTLAB mathematical programming solver is adopted to solve the model. A numerical example is presented for testing the model’s practical applicability.Findings: The main contribution of the present study is that a discrete time-space network model to study the medical resources allocation problem when an epidemic outbreak is formulated. It takes consideration of the time evolution and dynamic nature of the demand, which is different from most existing researches on medical resources allocation.Practical implications: In our model, the medicine logistics operation problem has been decomposed into several mutually correlated sub-problems, and then be solved systematically in the same decision scheme. Thus, the result will be much more suitable for real operations.Originality/value: In our model, the rationale that the medical resources allocated in early periods will take effect in subduing the spread of the epidemic spread and thus impact the demand in later periods has been for the first time incorporated. A win-win emergency rescue effect is achieved by the integrated and dynamic optimization model. The total rescue cost is controlled effectively, and meanwhile, inventory level in each urban health departments is restored and raised gradually.
Institute of Scientific and Technical Information of China (English)
WANGJian-feng; SUNChun-Lin; CHENYong-qing
2004-01-01
Ordinal optimization concentrates on isolating a subset of good designs with high probability and reduces the required simulation time dramatically for discrete event simulation. To obtain the same probability level,we may optimally allocate our computing budget among different designs,instead of equally simulating all different designs. In this paper we present an effective approach to optimally allocate computing budget for discrete-event system simulation. While ordinal optimization can dramatically reduce the computation cost, our approach can further reduce the already-low cost.
[Optimal allocation of irrigation water resources based on systematical strategy].
Cheng, Shuai; Zhang, Shu-qing
2015-01-01
With the development of the society and economy, as well as the rapid increase of population, more and more water is needed by human, which intensified the shortage of water resources. The scarcity of water resources and growing competition of water in different water use sectors reduce water availability for irrigation, so it is significant to plan and manage irrigation water resources scientifically and reasonably for improving water use efficiency (WUE) and ensuring food security. Many investigations indicate that WUE can be increased by optimization of water use. However, present studies focused primarily on a particular aspect or scale, which lack systematic analysis on the problem of irrigation water allocation. By summarizing previous related studies, especially those based on intelligent algorithms, this article proposed a multi-level, multi-scale framework for allocating irrigation water, and illustrated the basic theory of each component of the framework. Systematical strategy of optimal irrigation water allocation can not only control the total volume of irrigation water on the time scale, but also reduce water loss on the spatial scale. It could provide scientific basis and technical support for improving the irrigation water management level and ensuring the food security.
Hybrid particle swarm optimization for multiobjective resource allocation
Institute of Scientific and Technical Information of China (English)
Yi Yang; Li Xiaoxing; Gu Chunqin
2008-01-01
Resource allocation (RA) is the problem of allocating resources among various artifacts or business units to meet one or more expected goals,such as maximizing the profits,minimizing the costs,or achieving the best qualities.A complex multiobjective RA is addressed,and a multiobjective mathematical model is used to find solutions efficiently.Then,an improved particle swarm algorithm (mO_PSO) is proposed combined with a new particle diversity controller policies and dissipation operation.Meanwhile,a modified Pareto methods used in PSO to deal with multiobjectives optimization is presented.The effectiveness of the provided algorithm is validated by its application to some illustrative example dealing with multiobjective RA problems and with the comparative experiment with other algorithm.
Optimal Register Allocation by Augmented Left-Edge Algorithm on Arbitrary Control-Flow Structures
DEFF Research Database (Denmark)
Ruvald Pedersen, Mark; Madsen, Jan
2012-01-01
A new algorithm for optimal register allocation in context of high-level synthesis is presented. In this paper we show how the greedy left-edge algorithm can be leveraged to obtain a globally optimal allocation, that is computed in polynomial time. By splitting variables at block boundaries, allows...... for allocation to be done using only quasi-local and local allocation - avoiding the complexity of true global allocation. As local allocation is much simpler than global allocation, this approach emphasizes efficiency and ease of implementation - at a cost of an increased number of register transfers compared...
Scheduling Patients’ Appointments: Allocation of Healthcare Service Using Simulation Optimization
Directory of Open Access Journals (Sweden)
Ping-Shun Chen
2015-01-01
Full Text Available In the service industry, scheduling medical procedures causes difficulties for both patients and management. Factors such as fluctuations in customer demand and service time affect the appointment scheduling systems’ performance in terms of, for example, patients’ waiting time, idle time of resources, and total cost/profits. This research implements four appointment scheduling policies, i.e., constant arrival, mixed patient arrival, three-section pattern arrival, and irregular arrival, in an ultrasound department of a hospital in Taiwan. By simulating the four implemented policies’ optimization procedures, optimal or near-optimal solutions can be obtained for patients per arrival, patients’ inter-arrival time, and the number of the time slots for arrived patients. Furthermore, three objective functions are tested, and the results are discussed. The managerial implications and discussions are summarized to demonstrate how outcomes can be useful for hospital managers seeking to allocate their healthcare service capacities.
Optimal Allocation of Replicates for Measurement Evaluation Studies
Institute of Scientific and Technical Information of China (English)
Stanislav O.Zakharkin; Kyoungmi Kim; Alfred A.Bartolucci; Grier P.Page; David B.Allison
2006-01-01
Optimal experimental design is important for the efficient use of modern highthroughput technologies such as microarrays and proteomics. Multiple factors including the reliability of measurement system, which itself must be estimated from prior experimental work, could influence design decisions. In this study, we describe how the optimal number of replicate measures (technical replicates) for each biological sample (biological replicate) can be determined. Different allocations of biological and technical replicates were evaluated by minimizing the variance of the ratio of technical variance (measurement error) to the total variance (sum of sampling error and measurement error). We demonstrate that if the number of biological replicates and the number of technical replicates per biological sample are variable, while the total number of available measures is fixed, then the optimal allocation of replicates for measurement evaluation experiments requires two technical replicates for each biological replicate. Therefore, it is recommended to use two technical replicates for each biological replicate if the goal is to evaluate the reproducibility of measurements.
Optimal resource allocation solutions for heterogeneous cognitive radio networks
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Babatunde Awoyemi
2017-05-01
Full Text Available Cognitive radio networks (CRN are currently gaining immense recognition as the most-likely next-generation wireless communication paradigm, because of their enticing promise of mitigating the spectrum scarcity and/or underutilisation challenge. Indisputably, for this promise to ever materialise, CRN must of necessity devise appropriate mechanisms to judiciously allocate their rather scarce or limited resources (spectrum and others among their numerous users. ‘Resource allocation (RA in CRN', which essentially describes mechanisms that can effectively and optimally carry out such allocation, so as to achieve the utmost for the network, has therefore recently become an important research focus. However, in most research works on RA in CRN, a highly significant factor that describes a more realistic and practical consideration of CRN has been ignored (or only partially explored, i.e., the aspect of the heterogeneity of CRN. To address this important aspect, in this paper, RA models that incorporate the most essential concepts of heterogeneity, as applicable to CRN, are developed and the imports of such inclusion in the overall networking are investigated. Furthermore, to fully explore the relevance and implications of the various heterogeneous classifications to the RA formulations, weights are attached to the different classes and their effects on the network performance are studied. In solving the developed complex RA problems for heterogeneous CRN, a solution approach that examines and exploits the structure of the problem in achieving a less-complex reformulation, is extensively employed. This approach, as the results presented show, makes it possible to obtain optimal solutions to the rather difficult RA problems of heterogeneous CRN.
Optimal Resource Allocation for Network Protection: A Geometric Programming Approach
Preciado, Victor M; Enyioha, Chinwendu; Jadbabaie, Ali; Pappas, George
2013-01-01
We study the problem of containing spreading processes in arbitrary directed networks by distributing protection resources throughout the nodes of the network. We consider two types of protection resources are available: (i) Preventive resources able to defend nodes against the spreading (such as vaccines in a viral infection process), and (ii) corrective resources able to neutralize the spreading after it has reached a node (such as antidotes). We assume that both preventive and corrective resources have an associated cost and study the problem of finding the cost-optimal distribution of resources throughout the nodes of the network. We analyze these questions in the context of viral spreading processes in directed networks. We study the following two problems: (i) Given a fixed budget, find the optimal allocation of preventive and corrective resources in the network to achieve the highest level of containment, and (ii) when a budget is not specified, find the minimum budget required to control the spreading...
Optimal land use allocation of urban fringe in Guangzhou
Institute of Scientific and Technical Information of China (English)
GONG Jianzhou; LIU Yansui; CHEN Wenli
2012-01-01
In response to the strong drive for social and economic development,local governments have implemented urban master plans,providing measures and timeframes to address the continuous demand for land and to alleviate urban problems.In this paper,a multi-objective model was constructed to discuss the problem,including economic benefits and ecological effectiveness,in terms of land use optimization.A genetic algorithm was then adopted to solve the model,and a performance evaluation and sensitivity analysis were conducted using Pareto optimality.Results showed that a set of tradeoffs could be acquired by the allocation of land use.In addition,the Pareto solutions proved the model to be efficient; for example,a limit of 13,500 ha of urban area conformed to plan recommendations.The reduction in crop land,orchard land,grassland,and unused land provided further efficiencies.These results implied that further potential regional land resources remain and that the urban master plan is able to support sustainable local development in the years to come,as well as verified that it is feasible to use land use allocation multi-objective modeling and genetic algorithms.
Optimal Rate Allocation in Cluster-Tree WSNs
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Jose Lopez Vicario
2011-03-01
Full Text Available In this paper, we propose a solution to the problem of guaranteed time slot allocation in cluster-tree WSNs. Our design uses the so-called Network Utility Maximization (NUM approach as far as we aim to provide a fair distribution of the available resources. From the point of view of implementation, we extend here the authors’ proposed Coupled-Decompositions Method (CDM in order to compute the NUM problem inside the cluster tree topology and we prove the optimality of this new extended version of the method. As a result, we obtain a distributed solution that reduces the total amount of signalling information in the network up to a factor of 500 with respect to the classical techniques, that is, primal and dual decomposition. This is possible because the CDM finds the optimal solution with a small number of iterations. Furthermore, when we compare our solution to the standard-proposed First Come First Serve (FCFS policy, we realize that FCFS becomes pretty unfair as the traffic load in the network increases and thus, a fair allocation of resources can be considered whenever the price to pay in terms of signalling and computational complexity is controlled.
Optimal allocation of watershed management cost among different water users
Institute of Scientific and Technical Information of China (English)
Wang Zanxin; Margaret M.Calderon
2006-01-01
The issue of water scarcity highlights the importance of watershed management. A sound watershed management should make all water users share the incurred cost. This study analyzes the optimal allocation of watershed management cost among different water users. As a consumable, water should be allocated to different users the amounts in which their marginal utilities (Mus) or marginal products (MPs) of water are equal. The value of Mus or MPs equals the water price that the watershed manager charges. When water is simultaneously used as consumable and non-consumable, the watershed manager produces the quantity of water in which the sum of Mus and/or MPs for the two types of uses equals the marginal cost of water production. Each water user should share the portion of watershed management cost in the percentage that his MU or MP accounts for the sum of Mus and/or MPs. Thus, the price of consumable water does not equal the marginal cost of water production even if there is no public good.
Ant Colony Optimization for Route Allocation in Transportation Networks
Zamfirescu, Constantin-Bǎlǎ; Negulescu, Sorin; Oprean, Constantin; Banciu, Dorin
2009-04-01
The paper introduces a bio-inspired approach to solve the route allocation problem (RAP) in the transportation networks. The approach extends a well-known meta-heuristics algorithm with the real life constraints that are dealt with in the scheduling process (i.e. the uniform distribution of routes diversity for vehicles, the average distance travelled in a month, the driver's rest between subsequent trips etc.). The paper is focusing on the engineering aspects of employing bio-inspired algorithms (which proved to have near-optimal results for toy-like problems) to a real-life application domain. The approach proved to be capable of preserving the software components (agents) to the complexity and dynamics of the situation when the RAP requires incremental extensions of constraints to reflect the traffic conditions in the transportation network.
Optimal Time Allocation in Backscatter Assisted Wireless Powered Communication Networks
Lyu, Bin; Yang, Zhen; Gui, Guan; Sari, Hikmet
2017-01-01
This paper proposes a wireless powered communication network (WPCN) assisted by backscatter communication (BackCom). This model consists of a power station, an information receiver and multiple users that can work in either BackCom mode or harvest-then-transmit (HTT) mode. The time block is mainly divided into two parts corresponding to the data backscattering and transmission periods, respectively. The users first backscatter data to the information receiver in time division multiple access (TDMA) during the data backscattering period. When one user works in the BackCom mode, the other users harvest energy from the power station. During the data transmission period, two schemes, i.e., non-orthogonal multiple access (NOMA) and TDMA, are considered. To maximize the system throughput, the optimal time allocation policies are obtained. Simulation results demonstrate the superiority of the proposed model. PMID:28587171
Biometric Quantization through Detection Rate Optimized Bit Allocation
Chen, C.; Veldhuis, R. N. J.; Kevenaar, T. A. M.; Akkermans, A. H. M.
2009-12-01
Extracting binary strings from real-valued biometric templates is a fundamental step in many biometric template protection systems, such as fuzzy commitment, fuzzy extractor, secure sketch, and helper data systems. Previous work has been focusing on the design of optimal quantization and coding for each single feature component, yet the binary string—concatenation of all coded feature components—is not optimal. In this paper, we present a detection rate optimized bit allocation (DROBA) principle, which assigns more bits to discriminative features and fewer bits to nondiscriminative features. We further propose a dynamic programming (DP) approach and a greedy search (GS) approach to achieve DROBA. Experiments of DROBA on the FVC2000 fingerprint database and the FRGC face database show good performances. As a universal method, DROBA is applicable to arbitrary biometric modalities, such as fingerprint texture, iris, signature, and face. DROBA will bring significant benefits not only to the template protection systems but also to the systems with fast matching requirements or constrained storage capability.
Biometric Quantization through Detection Rate Optimized Bit Allocation
Directory of Open Access Journals (Sweden)
C. Chen
2009-01-01
Full Text Available Extracting binary strings from real-valued biometric templates is a fundamental step in many biometric template protection systems, such as fuzzy commitment, fuzzy extractor, secure sketch, and helper data systems. Previous work has been focusing on the design of optimal quantization and coding for each single feature component, yet the binary string—concatenation of all coded feature components—is not optimal. In this paper, we present a detection rate optimized bit allocation (DROBA principle, which assigns more bits to discriminative features and fewer bits to nondiscriminative features. We further propose a dynamic programming (DP approach and a greedy search (GS approach to achieve DROBA. Experiments of DROBA on the FVC2000 fingerprint database and the FRGC face database show good performances. As a universal method, DROBA is applicable to arbitrary biometric modalities, such as fingerprint texture, iris, signature, and face. DROBA will bring significant benefits not only to the template protection systems but also to the systems with fast matching requirements or constrained storage capability.
Strategy of Dynamic Bandwidth Allocation and Its Performance Analysis%一种动态带宽分配策略及其性能分析
Institute of Scientific and Technical Information of China (English)
金顺福; 吕倩; 王朋; 李小良
2012-01-01
针对当前网络中不同业务的服务质量需求,综合考虑业务优先级及业务负载,提出一种动态带宽分配策略—E-DBA.建立具有多重工作休假机制的Geom/G/1排队模型,使用嵌入式马尔可夫链导出排队模型的稳态指标.给出E-DBA的平均响应时间和信道利用率等系统性能指标表达式,并通过实验分析了第Ⅱ类业务的保障带宽对系统性能的影响.%Aiming at Quality of Service(QoS) requirements of different traffics in the current network, a dynamic bandwidth allocation strategy named E-DBA is proposed by taking into account both the traffic priority and system load. Geom/G/1 queuing model with multiple working vacations mechanism is established. By using the method of embedded Markov chain, the steady-state measures of the queueing model are derived. The performance measures in terms of the average response time and system utility of E-DBA are given. With experiments, the influence of the guaranteed bandwidth of class II traffic on the system performance is illustrated.
OPTIMAL POWER ALLOCATION WITH AF AND SDF STRATEGIES IN DUAL-HOP COOPERATIVE MIMO NETWORKS
Institute of Scientific and Technical Information of China (English)
Xu Xiaorong; Zheng Baoyu; Zhang Jianwu
2010-01-01
Dual-hop cooperative Multiple-Input Multiple-Output (MIMO) network with multi-relay cooperative communication is introduced. Power allocation problem with Amplify-and-Forward (AF) and Selective Decode-and-Forward (SDF) strategies in multi-node scenario are formulated and solved respectively. Optimal power allocation schemes that maximize system capacity with AF strategy are presented. In addition,optimal power allocation methods that minimize asymptotic Symbol Error Rate (SER) with SDF cooperative protocol in multi-node scenario are also proposed. Furthermore,performance comparisons are provided in terms of system capacity and approximate SER. Numerical and simulation results confirm our theoretical analysis. It is revealed that,maximum system capacity could be obtained when powers are allocated optimally with AF protocol,while minimization of system's SER could also be achieved with optimum power allocation in SDF strategy. In multi-node scenario,those optimal power allocation algorithms are superior to conventional equal power allocation schemes.
Directory of Open Access Journals (Sweden)
Hong-an Yang
2014-01-01
Full Text Available We focus on solving Stochastic Job Shop Scheduling Problem (SJSSP with random processing time to minimize the expected sum of earliness and tardiness costs of all jobs. To further enhance the efficiency of the simulation optimization technique of embedding Evolutionary Strategy in Ordinal Optimization (ESOO which is based on Monte Carlo simulation, we embed Optimal Computing Budget Allocation (OCBA technique into the exploration stage of ESOO to optimize the performance evaluation process by controlling the allocation of simulation times. However, while pursuing a good set of schedules, “super individuals,” which can absorb most of the given computation while others hardly get any simulation budget, may emerge according to the allocating equation of OCBA. Consequently, the schedules cannot be evaluated exactly, and thus the probability of correct selection (PCS tends to be low. Therefore, we modify OCBA to balance the computation allocation: (1 set a threshold of simulation times to detect “super individuals” and (2 follow an exclusion mechanism to marginalize them. Finally, the proposed approach is applied to an SJSSP comprising 8 jobs on 8 machines with random processing time in truncated normal, uniform, and exponential distributions, respectively. The results demonstrate that our method outperforms the ESOO method by achieving better solutions.
Bandwidth auction for SVC streaming in dynamic multi-overlay
Xiong, Yanting; Zou, Junni; Xiong, Hongkai
2010-07-01
In this paper, we study the optimal bandwidth allocation for scalable video coding (SVC) streaming in multiple overlays. We model the whole bandwidth request and distribution process as a set of decentralized auction games between the competing peers. For the upstream peer, a bandwidth allocation mechanism is introduced to maximize the aggregate revenue. For the downstream peer, a dynamic bidding strategy is proposed. It achieves maximum utility and efficient resource usage by collaborating with a content-aware layer dropping/adding strategy. Also, the convergence of the proposed auction games is theoretically proved. Experimental results show that the auction strategies can adapt to dynamic join of competing peers and video layers.
Institute of Scientific and Technical Information of China (English)
宋军; 甘育裕; 吴资玉
2003-01-01
The request/transmit based upstream bandwidth resource allocation policy of DOCSIS introduces a trouble to the quality of the data service provided in the I-IFC networks. In this paper, the mechanism of the upstream data transrmitting and the process of data service transmitting in the HFC networks are described in detail, and the perfor- mance of the data service in HFC networks is analyzed. An advanced upstream bandwidth resource allocation policy is proposed to improve the quality of the data service in the HFC networks.
Energy Technology Data Exchange (ETDEWEB)
Ramamurthy, Byravamurthy [University of Nebraska-Lincoln
2014-05-05
In this project, developed scheduling frameworks for dynamic bandwidth demands for large-scale science applications. In particular, we developed scheduling algorithms for dynamic bandwidth demands in this project. Apart from theoretical approaches such as Integer Linear Programming, Tabu Search and Genetic Algorithm heuristics, we have utilized practical data from ESnet OSCARS project (from our DOE lab partners) to conduct realistic simulations of our approaches. We have disseminated our work through conference paper presentations and journal papers and a book chapter. In this project we addressed the problem of scheduling of lightpaths over optical wavelength division multiplexed (WDM) networks. We published several conference papers and journal papers on this topic. We also addressed the problems of joint allocation of computing, storage and networking resources in Grid/Cloud networks and proposed energy-efficient mechanisms for operatin optical WDM networks.
Optimal Relay Assignment and Power Allocation for Cooperative Communications
Institute of Scientific and Technical Information of China (English)
Kun Xie; Jian-Nong Cao; Ji-Gang Wen
2013-01-01
Cooperative communication for wireless networks has gained a lot of recent interest due to its ability to mitigate fading with exploration of spatial diversity.In this paper,we study a joint optimization problem of jointly considering transmission mode selection,relay assignment and power allocation to maximize the capacity of the network through cooperative wireless communications.This problem is much more challenging than relay assignment considered in literature work which simply targets to maximize the transmission capacity for a single transmission pair.We formulate the problem as a variation of the maximum weight matching problem where the weight is a function over power values which must meet power constraints (VMWMC).Although VMWMC is a non-convex problem whose complexity increases exponentially with the number of relay nodes,we show that the duality gap of VMWMC is virtual zero.Based on this result,we propose a solution using Lagrange dual decomposition to reduce the computation complexity.We do simulations to evaluate the performance of the proposed solution.The results show that our solution can achieve maximum network capacity with much less computation time compared with exhaustive search,and our solution outperforms existing sub-optimal solutions that can only achieve much lower network capacity.
Optimal pandemic influenza vaccine allocation strategies for the Canadian population.
Directory of Open Access Journals (Sweden)
Ashleigh R Tuite
Full Text Available BACKGROUND: The world is currently confronting the first influenza pandemic of the 21(st century. Influenza vaccination is an effective preventive measure, but the unique epidemiological features of swine-origin influenza A (H1N1 (pH1N1 introduce uncertainty as to the best strategy for prioritization of vaccine allocation. We sought to determine optimal prioritization of vaccine distribution among different age and risk groups within the Canadian population, to minimize influenza-attributable morbidity and mortality. METHODOLOGY/PRINCIPAL FINDINGS: We developed a deterministic, age-structured compartmental model of influenza transmission, with key parameter values estimated from data collected during the initial phase of the epidemic in Ontario, Canada. We examined the effect of different vaccination strategies on attack rates, hospitalizations, intensive care unit admissions, and mortality. In all scenarios, prioritization of high-risk individuals (those with underlying chronic conditions and pregnant women, regardless of age, markedly decreased the frequency of severe outcomes. When individuals with underlying medical conditions were not prioritized and an age group-based approach was used, preferential vaccination of age groups at increased risk of severe outcomes following infection generally resulted in decreased mortality compared to targeting vaccine to age groups with higher transmission, at a cost of higher population-level attack rates. All simulations were sensitive to the timing of the epidemic peak in relation to vaccine availability, with vaccination having the greatest impact when it was implemented well in advance of the epidemic peak. CONCLUSIONS/SIGNIFICANCE: Our model simulations suggest that vaccine should be allocated to high-risk groups, regardless of age, followed by age groups at increased risk of severe outcomes. Vaccination may significantly reduce influenza-attributable morbidity and mortality, but the benefits are
Institute of Scientific and Technical Information of China (English)
YAO Xin-feng; YAO Xia; TIAN Yong-chao; NI Jun; LIU Xiao-jun; CAO Wei-xing; ZHU Yan
2013-01-01
Plant nitrogen (N) uptake is a good indicator of cropNstatus. In this study, a new method was designed to determine the central wavelength, optimal bandwidth and vegetation indices for predicting plantNuptake (gNm-2) in winter wheat (Triticum aestivum L.). The data were collected from the ground-based hyperspectral reflectance measurements in eight field experiments on winter wheat of different years, eco-sites, varieties,Nrates, sowing dates, and densities. The plantNuptake index (PNUI) based on NDVI of 807 nm combined with 736 nm was selected as the optimal vegetation index, and a linear model was developed with R2 of 0.870 and RMSE of 1.546 gNm-2 for calibration, and R2 of 0.834, RMSE of 1.316 gNm-2, slope of 0.934, and intercept of 0.001 for validation. Then, the effect of the bandwidth of central wavelengths on model performance was determined based on the interaction between central wavelength and bandwidth expansion. The results indicated that the optimal bandwidth varies with the changes of the central wavelength and with the interaction between the two bands in one vegetation index. These findings are important for prediction and diagnosis of plantNuptake more precise and accurate in crop management.
An Indirect Simulation-Optimization Model for Determining Optimal TMDL Allocation under Uncertainty
Directory of Open Access Journals (Sweden)
Feng Zhou
2015-11-01
Full Text Available An indirect simulation-optimization model framework with enhanced computational efficiency and risk-based decision-making capability was developed to determine optimal total maximum daily load (TMDL allocation under uncertainty. To convert the traditional direct simulation-optimization model into our indirect equivalent model framework, we proposed a two-step strategy: (1 application of interval regression equations derived by a Bayesian recursive regression tree (BRRT v2 algorithm, which approximates the original hydrodynamic and water-quality simulation models and accurately quantifies the inherent nonlinear relationship between nutrient load reductions and the credible interval of algal biomass with a given confidence interval; and (2 incorporation of the calibrated interval regression equations into an uncertain optimization framework, which is further converted to our indirect equivalent framework by the enhanced-interval linear programming (EILP method and provides approximate-optimal solutions at various risk levels. The proposed strategy was applied to the Swift Creek Reservoir’s nutrient TMDL allocation (Chesterfield County, VA to identify the minimum nutrient load allocations required from eight sub-watersheds to ensure compliance with user-specified chlorophyll criteria. Our results indicated that the BRRT-EILP model could identify critical sub-watersheds faster than the traditional one and requires lower reduction of nutrient loadings compared to traditional stochastic simulation and trial-and-error (TAE approaches. This suggests that our proposed framework performs better in optimal TMDL development compared to the traditional simulation-optimization models and provides extreme and non-extreme tradeoff analysis under uncertainty for risk-based decision making.
A Novel Algorithm for Optimizing Multiple Services Resource Allocation
Directory of Open Access Journals (Sweden)
Amjad Gawanmeh
2016-06-01
Full Text Available Resource provisioning becomes more and more challenging problem in cloud computing environment since cloudbased services become more numerous and dynamic. The problem of scheduling multiple tasks for multiple users on a given number of resources is considered NP-Complete problem, and therefore, several heuristic based research methods were proposed, yet, there are still many improvements can be done, since the problem has several optimization parameters. In addition, most proposed solutions are built on top of several assumptions and simplifications by applying computational methods such as game theory, fuzzy logic, or evolutionary computing. This paper presents an algorithm to address the problem of resource allocation across a cloud-based network, where several resources are available, and the cost of computational service depends on the amount of computation. The algorithm is applicable without restrictions on cost vector or compaction time matrix as opposed to methods in the literature. In addition, the execution of the algorithm shows better utility compared to methods applied on similar problems.
Directory of Open Access Journals (Sweden)
Ahmed Nabih Zaki Rashed
2012-06-01
Full Text Available The effects of temperature, and operating signal wavelength on high frequency radio frequency transmission characteristics are deeply investigated against various materials based electro optic modulator devices such as lithium Niobate (LiNbO3, polymer, and semiconductor materials. On the other hand, we have developed the optimization of the electro optic modulator parameters where the effective index plays an essential role in the evaluation of the bandwidth structure. The effects of design parameters on the modulating voltage and optical bandwidth are also investigated for different materials based electro optic modulators by using rigorous transmission modeling techniques. The low loss wide bandwidth capability of optoelectronic systems makes them attractive for the transmission and processing of microwave signals, while the development of high capacity optical communication systems has required the use of modulation techniques in optical transmitters and receivers. This paper has presented the low loss wide bandwidth for different electrooptic modulators based on design of optimization parameters for high speed transmission performance.
Optimizing Bandwidth Limited Problems Using One-SidedCommunication and Overlap
Energy Technology Data Exchange (ETDEWEB)
Bell, Christian; Bonachea, Dan; Nishtala, Rajesh; Yelick, Katherine
2005-10-14
Partitioned Global Address Space languages like Unified Parallel C (UPC) are typically valued for their expressiveness, especially for computations with fine-grained random accesses. In this paper we show that the one-sided communication model used in these languages also has a significant performance advantage for bandwidth-limited applications. We demonstrate this benefit through communication microbenchmarks and a case-study that compares UPC and MPI implementations of the NAS Fourier Transform (FT) benchmark. Our optimizations rely on aggressively overlapping communication with computation but spreading communication events throughout the course of the local computation. This alleviates the potential communication bottleneck that occurs when the communication is packed into a single phase (e.g., the large all-to-all in a multidimensional FFT). Even though the new algorithms require more messages for the same total volume of data, the resulting overlap leads to speedups of over 1.75x and 1.9x for the two-sided and one-sided implementations, respectively, when compared to the default NAS Fortran/MPI release. Our best one-sided implementations show an average improvement of 15 percent over our best two-sided implementations. We attribute this difference to the lower software overhead of one-sided communication, which is partly fundamental to the semantic difference between one-sided and two-sided communication. Our UPC results use the Berkeley UPC compiler with the GASNet communication system, and demonstrate the portability and scalability of that language and implementation, with performance approaching 0.5TFlop/s on the FT benchmark running on 512 processors.
Optimization of Power Allocation for Multiusers in Multi-Spot-Beam Satellite Communication Systems
Directory of Open Access Journals (Sweden)
Heng Wang
2014-01-01
Full Text Available In recent years, multi-spot-beam satellite communication systems have played a key role in global seamless communication. However, satellite power resources are scarce and expensive, due to the limitations of satellite platform. Therefore, this paper proposes optimizing the power allocation of each user in order to improve the power utilization efficiency. Initially the capacity allocated to each user is calculated according to the satellite link budget equations, which can be achieved in the practical satellite communication systems. The problem of power allocation is then formulated as a convex optimization, taking account of a trade-off between the maximization of the total system capacity and the fairness of power allocation amongst the users. Finally, an iterative algorithm based on the duality theory is proposed to obtain the optimal solution to the optimization. Compared with the traditional uniform resource allocation or proportional resource allocation algorithms, the proposed optimal power allocation algorithm improves the fairness of power allocation amongst the users. Moreover, the computational complexity of the proposed algorithm is linear with both the numbers of the spot beams and users. As a result, the proposed power allocation algorithm is easy to be implemented in practice.
Optimizing the Allocation of Material Flow in a Logistics System
Tanka Milkova
2013-01-01
The article is devoted to the issue of the optimum allocation of material flow in a logistics system, the author’s proposition being that the allocation and movement of the material flow in a logistics system can be rationalized, based on the use of special approaches and techniques. There is presented the economic formulation of the problem and is constructed the economic and mathematical model ensuring the movement of the material flow in a logistics system at minimum cost of its transporta...
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
For an advanced aircraft, the amount of its effectors is much more than that for a traditional one, the functions of effectors are more complex and the coupling between each other is more severe. Based on the current control allocation research, this paper puts forward the concept and framework of the control allocation and management system for aircrafts with redundancy con-trol effectors. A new optimal control allocation method, bases sequenced optimal (BSO) method, is then presented. By analyz-ing the physical meaning of the allocation process of BSO method, four types of management strategies are adopted by the system, which act on the control allocation process under different flight conditions, mission requirements and effectors work-ing conditions. Simulation results show that functions of the control allocation system are extended and the system adaptability to flight status, mission requirements and effector failure conditions is improved.
Optimum Power and Rate Allocation for Coded V-BLAST: Average Optimization
Kostina, Victoria
2010-01-01
An analytical framework for performance analysis and optimization of coded V-BLAST is developed. Average power and/or rate allocations to minimize the outage probability as well as their robustness and dual problems are investigated. Compact, closed-form expressions for the optimum allocations and corresponding system performance are given. The uniform power allocation is shown to be near optimum in the low outage regime in combination with the optimum rate allocation. The average rate allocation provides the largest performance improvement (extra diversity gain), and the average power allocation offers a modest SNR gain limited by the number of transmit antennas but does not increase the diversity gain. The dual problems are shown to have the same solutions as the primal ones. All these allocation strategies are shown to be robust. The reported results also apply to coded multiuser detection and channel equalization systems relying on successive interference cancelation.
On the Optimal Radiation Bandwidth of Printed Slot Antennas Surrounded by EBGs
Neto, A.; Llombart, N.; Gerini, G.; Maagt, P. de
2006-01-01
This paper describes a design strategy to achieve the maximum bandwidth and efficiency for a printed slot antenna surrounded by EBGs. First the dielectric constant and the thickness of the dielectric slab that guarantees an acceptable front to back radiation ratio is identified. Then electromagnetic
Zeng,Y.; Huang, W.; Jin, W.; Li, S
2016-01-01
The optimization of land-use allocation is one of important approaches to achieve regional sustainable development. This study selects Chang-Zhu-Tan agglomeration as study area and proposed a new land use optimization allocation model. Using multi-agent based simulation model, the future urban land use optimization allocation was simulated in 2020 and 2030 under three different scenarios. This kind of quantitative information about urban land use optimization allocation and urban expansions i...
Optimal Rate Allocation Algorithm for Multiple Source Video Streaming
Institute of Scientific and Technical Information of China (English)
戢彦泓; 郭常杰; 钟玉琢; 孙立峰
2004-01-01
Video streaming is one of the most important applications used in the best-effort Internet.This paper presents a new scheme for multiple source video streaming in which the traditional fine granular scalable coding was rebuilt into a multiple sub-streams based transmission model.A peak signal to noise ratio based stream rate allocation algorithm was then developed based on the transmission model.In tests,the algorithm performance is about 1 dB higher than that of a uniform rate allocation algorithm.Therefore,this scheme can overcome bottlenecks along a single link and smooth jitter to achieve high quality and stable video.
Bandwidth optimization of compact microstrip antenna for PCS/DCS/bluetooth application
Singh, Vinod; Ali, Zakir; Ayub, Shahanaz; Singh, Ashutosh
2014-09-01
A novel compact broadband microstrip patch antenna is presented for various wireless applications. The proposed antenna has been fabricated and the impedance bandwidth and radiation pattern are measured. The simulated and measured antenna characteristics along with radiation pattern and gain are presented. It is stated that the proposed designed antenna can completely cover the required band widths of Digital communication system (DCS 1.71-1.88 GHz), Personal communication system (PCS 1.85-1.88 GHz) and IEEE 802.11b/g (2.4-2.485 GHz) with satisfactory radiation characteristics. The Experimental result shows that the proposed antenna presents a bandwidth 60.25% covering the range of 1.431-2.665 GHz with the maximum radiation efficiency 90%.
Anytime coding on the infinite bandwidth AWGN channel: A sequential semi-orthogonal optimal code
Sahai, Anant
2006-01-01
It is well known that orthogonal coding can be used to approach the Shannon capacity of the power-constrained AWGN channel without a bandwidth constraint. This correspondence describes a semi-orthogonal variation of pulse position modulation that is sequential in nature -- bits can be ``streamed across'' without having to buffer up blocks of bits at the transmitter. ML decoding results in an exponentially small probability of error as a function of tolerated receiver delay and thus eventually...
Delegated Portfolio Management and Optimal Allocation of Portfolio Managers
DEFF Research Database (Denmark)
Christensen, Michael; Vangsgaard Christensen, Michael; Gamskjaer, Ken
2015-01-01
In this article, we investigate whether the application of the mean-variance framework on portfolio manager allocation offers any out-of-sample benefits compared to a naïve strategy of equal weighting. Based on an exclusive data-set of high-net-worth (HNW) investors, we utilize a wide variety...
Electricity Portfolio Management: Optimal Peak / Off-Peak Allocations
R. Huisman (Ronald); R.J. Mahieu (Ronald); F. Schlichter (Felix)
2007-01-01
textabstractElectricity purchasers manage a portfolio of contracts in order to purchase the expected future electricity consumption profile of a company or a pool of clients. This paper proposes a mean-variance framework to address the concept of structuring the portfolio and focuses on how to alloc
Regional allocation of investment as a hierarchical optimization problem
Bagchi, Arunabha; Olsder, G.J.; Strijbos, R.C.W.
1981-01-01
A new formulation is given for the well-known problem of investment allocation between regions in the framework of a planning model. The case of a dual economy with a Cobb-Douglas production function is worked out in detail with an illustrative numerical example. The corresponding problem for an
Directory of Open Access Journals (Sweden)
Anna Michalak
2014-01-01
Full Text Available In this paper we examine the concept of Pareto optimality in a simplified Gale economic model without assuming continuity of the utility functions. We apply some existing results on higher-order optimality conditions to get necessary and sufficient conditions for a locally Pareto optimal allocation.
Sample-Path Optimization of Buffer Allocations in a Tandem Queue - Part I : Theoretical Issues
Gürkan, G.; Ozge, A.Y.
1996-01-01
This is the first of two papers dealing with the optimal bu er allocation problem in tandem manufacturing lines with unreliable machines.We address the theoretical issues that arise when using sample-path optimization, a simulation-based optimization method, to solve this problem.Sample-path optimiz
An Improved Genetic Algorithm for Allocation Optimization of Distribution Centers
Institute of Scientific and Technical Information of China (English)
钱晶; 庞小红; 吴智铭
2004-01-01
This paper introduced an integrated allocation model for distribution centers (DCs). The facility cost, inventory cost, transportation cost and service quality were considered in the model. An improved genetic algorithm (IGA) was proposed to solve the problem. The improvement of IGA is based on the idea of adjusting crossover probability and mutation probability. The IGA is supplied by heuristic rules too. The simulation results show that the IGA is better than the standard GA(SGA) in search efficiency and equality.
On optimal allocation in binary response trials; is adaptive design really necessary?
Azriel, David; Rinott, Yosef
2011-01-01
We consider the classical problem of selecting the best of two treatments in clinical trials with binary response. The target is to find the design that maximizes the power of the relevant test. Many papers use a normal approximation to the power function and claim that \\textit{Neyman allocation} that assigns subjects to treatment groups according to the ratio of the responses' standard deviations, should be used. As the standard deviations are unknown, an adaptive design is often recommended. The asymptotic justification of this approach is arguable, since it uses the normal approximation in tails where the error in the approximation is larger than the estimated quantity. We consider two different approaches for optimality of designs that are related to Pitman and Bahadur definitions of relative efficiency of tests. We prove that the optimal allocation according to the Pitman criterion is the balanced allocation and that the optimal allocation according to the Bahadur approach depends on the unknown paramete...
Wang, Zhiteng; Zhang, Hongjun; Zhang, Rui; Li, Yong; Zhang, Xuliang
2014-01-01
Service oriented modeling and simulation are hot issues in the field of modeling and simulation, and there is need to call service resources when simulation task workflow is running. How to optimize the service resource allocation to ensure that the task is complete effectively is an important issue in this area. In military modeling and simulation field, it is important to improve the probability of success and timeliness in simulation task workflow. Therefore, this paper proposes an optimization algorithm for multipath service resource parallel allocation, in which multipath service resource parallel allocation model is built and multiple chains coding scheme quantum optimization algorithm is used for optimization and solution. The multiple chains coding scheme quantum optimization algorithm is to extend parallel search space to improve search efficiency. Through the simulation experiment, this paper investigates the effect for the probability of success in simulation task workflow from different optimization algorithm, service allocation strategy, and path number, and the simulation result shows that the optimization algorithm for multipath service resource parallel allocation is an effective method to improve the probability of success and timeliness in simulation task workflow.
Directory of Open Access Journals (Sweden)
Zhiteng Wang
2014-01-01
Full Text Available Service oriented modeling and simulation are hot issues in the field of modeling and simulation, and there is need to call service resources when simulation task workflow is running. How to optimize the service resource allocation to ensure that the task is complete effectively is an important issue in this area. In military modeling and simulation field, it is important to improve the probability of success and timeliness in simulation task workflow. Therefore, this paper proposes an optimization algorithm for multipath service resource parallel allocation, in which multipath service resource parallel allocation model is built and multiple chains coding scheme quantum optimization algorithm is used for optimization and solution. The multiple chains coding scheme quantum optimization algorithm is to extend parallel search space to improve search efficiency. Through the simulation experiment, this paper investigates the effect for the probability of success in simulation task workflow from different optimization algorithm, service allocation strategy, and path number, and the simulation result shows that the optimization algorithm for multipath service resource parallel allocation is an effective method to improve the probability of success and timeliness in simulation task workflow.
Bandwidth optimization design of a multi degree of freedom MEMS gyroscope.
Si, Chaowei; Han, Guowei; Ning, Jin; Yang, Fuhua
2013-08-14
A new robust multi-degree of freedom (multi-DOF) MEMS gyroscope is presented in this paper. The designed gyroscope has its bandwidth and amplification factor of the sense mode adjusted more easily than the previous reported multi-DOF MEMS gyroscopes. Besides, a novel spring system with very small coupling stiffness is proposed, which helps achieve a narrow bandwidth and a high amplification factor for a 2-DOF vibration system. A multi-DOF gyroscope with the proposed weak spring system is designed, and simulations indicate that when the operating frequency is set at 12.59 kHz, the flat frequency response region of the sense mode can be designed as narrow as 80 Hz, and the amplification factor of the sense mode at the operating frequency is up to 91, which not only protects the amplification factor from instability against process and temperature variations, but also sacrifices less performance. An experiment is also carried out to demonstrate the validity of the design. The multi-DOF gyroscope with the proposed weak coupling spring system is capable of achieving a good tradeoff between robustness and the performance.
Bandwidth Optimization Design of a Multi Degree of Freedom MEMS Gyroscope
Directory of Open Access Journals (Sweden)
Fuhua Yang
2013-08-01
Full Text Available A new robust multi-degree of freedom (multi-DOF MEMS gyroscope is presented in this paper. The designed gyroscope has its bandwidth and amplification factor of the sense mode adjusted more easily than the previous reported multi-DOF MEMS gyroscopes. Besides, a novel spring system with very small coupling stiffness is proposed, which helps achieve a narrow bandwidth and a high amplification factor for a 2-DOF vibration system. A multi-DOF gyroscope with the proposed weak spring system is designed, and simulations indicate that when the operating frequency is set at 12.59 kHz, the flat frequency response region of the sense mode can be designed as narrow as 80 Hz, and the amplification factor of the sense mode at the operating frequency is up to 91, which not only protects the amplification factor from instability against process and temperature variations, but also sacrifices less performance. An experiment is also carried out to demonstrate the validity of the design. The multi-DOF gyroscope with the proposed weak coupling spring system is capable of achieving a good tradeoff between robustness and the performance.
Optimal redundancy allocation for reliability systems with imperfect switching
Institute of Scientific and Technical Information of China (English)
Lun Ran; Jinlin Li; Xujie Jia; Hongrui Chu
2014-01-01
The problem of stochastical y al ocating redundant com-ponents to increase the system lifetime is an important topic of reliability. An optimal redundancy al ocation is proposed, which maximizes the expected lifetime of a reliability system with sub-systems consisting of components in paral el. The constraints are minimizing the total resources and the sizes of subsystems. In this system, each switching is independent with each other and works with probability p. Two optimization problems are studied by an incremental algorithm and dynamic programming technique respectively. The incremental algorithm proposed could obtain an approximate optimal solution, and the dynamic programming method could generate the optimal solution.
Directory of Open Access Journals (Sweden)
T.P. Shabeera
2017-04-01
Full Text Available Nowadays data-intensive applications for processing big data are being hosted in the cloud. Since the cloud environment provides virtualized resources for computation, and data-intensive applications require communication between the computing nodes, the placement of Virtual Machines (VMs and location of data affect the overall computation time. Majority of the research work reported in the current literature consider the selection of physical nodes for placing data and VMs as independent problems. This paper proposes an approach which considers VM placement and data placement hand in hand. The primary objective is to reduce cross network traffic and bandwidth usage, by placing required number of VMs and data in Physical Machines (PMs which are physically closer. The VM and data placement problem (referred as MinDistVMDataPlacement problem is defined in this paper and has been proved to be NP- Hard. This paper presents and evaluates a metaheuristic algorithm based on Ant Colony Optimization (ACO, which selects a set of adjacent PMs for placing data and VMs. Data is distributed in the physical storage devices of the selected PMs. According to the processing capacity of each PM, a set of VMs are placed on these PMs to process data stored in them. We use simulation to evaluate our algorithm. The results show that the proposed algorithm selects PMs in close proximity and the jobs executed in the VMs allocated by the proposed scheme outperforms other allocation schemes.
Impact-Based Area Allocation for Yield Optimization in Integrated Circuits
Abraham, Billion; Widodo, Arif; Chen, Poki
2016-06-01
In analog integrated circuit (IC) layout, area allocation is a very important issue for achieving good mismatch cancellation. However, most IC layout papers focus only on layout strategy to reduce systematic mismatch. In 2006, an outstanding paper presenting area allocation strategy was published to introduce technique for random mismatch reduction. Instead of using general theoretical study to prove the strategy, this research presented close-to-optimum simulations only on case-bycase basis. The impact-based area allocation for yield optimization in integrated circuits is proposed in this chapter. To demonstrate the corresponding strategy, not only a theoretical analysis but also an integral nonlinearity-based yield simulation will be given to derive optimum area allocation for binary weighted current steering digital-to-analog converter (DAC). The result will be concluded to convince IC designers how to allocate area for critical devices in an optimum way.
Kapur, P. K.; Pham, Hoang; Chanda, Udayan; Kumar, Vijay
2013-09-01
Allocation of efforts to a software development project during the testing phase is a multifaceted task for software managers. The challenges become stiffer when the nature of the development process is considered in the dynamic environment. Many software reliability growth models have been proposed in last decade to minimise the total testing-effort expenditures, but mostly under static assumption. The main purpose of this article is to investigate an optimal resource allocation plan to minimise the cost of software during the testing and operational phase under dynamic condition. An elaborate optimisation policy based on the optimal control theory is proposed and numerical examples are illustrated. This article also studies the optimal resource allocation problems for various conditions by examining the behaviour of the model parameters and also suggests policy for the optimal release time of the software. The experimental results greatly help us to identify the contribution of each selected parameter and its weight.
Game theory approach to optimal capital cost allocation in pollution control
Institute of Scientific and Technical Information of China (English)
1998-01-01
This paper tries to integrate game theory, a very usefultool to resolve conflict phenomena, with optimal capital costallocation issue in total emission control. First the necessity ofallocating optimal capital costs fairly and reasonably amongpolluters in total emission control is analyzed. Then thepossibility of applying game theory to the issue of the optimalcapital cost allocation is expounded. Next the cooperative N-person game model of the optimal capital cost allocation and itssolution ways including method based on Shapley value, least coremethod, weak least core methods, proportional least core method,CGA method, MCRS method and so on are delineated. Finally throughapplication of these methods it is concluded that to apply gamethory in the optimal capital cost allocation issue is helpful toimplement the total emission control planning schemes successfully,to control pollution effectively, and to ensure sustainable development.
A Comparative Study between Optimization and Market-Based Approaches to Multi-Robot Task Allocation
Directory of Open Access Journals (Sweden)
Mohamed Badreldin
2013-01-01
Full Text Available This paper presents a comparative study between optimization-based and market-based approaches used for solving the Multirobot task allocation (MRTA problem that arises in the context of multirobot systems (MRS. The two proposed approaches are used to find the optimal allocation of a number of heterogeneous robots to a number of heterogeneous tasks. The two approaches were extensively tested over a number of test scenarios in order to test their capability of handling complex heavily constrained MRS applications that include extended number of tasks and robots. Finally, a comparative study is implemented between the two approaches and the results show that the optimization-based approach outperforms the market-based approach in terms of optimal allocation and computational time.
Nonlinear optimization of load allocation in a manufacturing system
Institute of Scientific and Technical Information of China (English)
GUO Cai-fen; WANG Ning-sheng
2006-01-01
Based on the queuing theory, a nonlinear optimization model is proposed in this paper. A novel transformation of optimization variables is devised and the constraints are properly combined so as to make this model into a convex one, from which the Lagrangian function and the KKT conditions are derived. The interiorpoint method for convex optimization is presented here as a computationally efficient tool. Finally, this model is evaluated on a real example, from which such conclusions are drawn that the optimum result can ensure the full utilization of machines and the least amount of WIP in manufacturing systems; the interior-point method for convex optimization needs fewer iterations with significant computational savings. It appears that many non-linear optimization problems in the industrial engineering field would be amenable to this method of solution.
Directory of Open Access Journals (Sweden)
B. Sathish Kumar
2015-07-01
Full Text Available Rapid development of wireless services, leads to ubiquitous personal connectivity in the world. The demand for multimedia interactivity is higher in the world which leads to the requirement of high data transmission rate. Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM is a future wireless service which is used to overcome the existing service problems such as development of subscriber pool and higher throughput per user. Although it overcomes the problems in existing services, resource allocation becomes one of the major issues in the MIMO-OFDM systems. Resource allocation in MIMO-OFDM is the optimization of subcarrier and power allocation for the user. The overall performance of the system can be improved only with the efficient resource allocation approach. The user data rate is increased by efficient allocation of the subcarrier and power allocation for each user at the base station, which is subject to constraints on total power and bit error rate. In this study, the problem of resource allocation in MIMO-OFDM system is tackled using hybrid artificial bee colony optimization algorithm based on a crossover operation along with Poisson-Jensen in equation. The experimental results show that the proposed methodology is better than the existing techniques.
A Study on Optimal Resource Allocation of Taxis
Directory of Open Access Journals (Sweden)
Lv Xiao Peng
2016-01-01
Full Text Available As taxis play an increasingly important role in urban traffic system, the research on the supply and demand of taxis and the design of an optimal model of taxis supply has an importantly practical significance. In this paper, we used the traffic bureau data of Guangzhou, and determined the rate of empty driving as the index to establish the model. Nonlinear programming method was uesd to establish the optimal model of taxis quantity to meet the maximum income and maximum passenger satisfaction. Finally we got the optimal number of taxis was 37537.59
Playing games against nature: optimal policies for renewable resource allocation
Ermon, Stefano; Gomes, Carla P; Selman, Bart
2012-01-01
In this paper we introduce a class of Markov decision processes that arise as a natural model for many renewable resource allocation problems. Upon extending results from the inventory control literature, we prove that they admit a closed form solution and we show how to exploit this structure to speed up its computation. We consider the application of the proposed framework to several problems arising in very different domains, and as part of the ongoing effort in the emerging field of Computational Sustainability we discuss in detail its application to the Northern Pacific Halibut marine fishery. Our approach is applied to a model based on real world data, obtaining a policy with a guaranteed lower bound on the utility function that is structurally very different from the one currently employed.
Cognitive radio based optimal channel sensing and resources allocation
Vijayasarveswari, V.; Khatun, S.; Fakir, M. M.; Nayeem, M. N.; Kamarudin, L. M.; Jakaria, A.
2017-03-01
Cognitive radio (CR) is the latest type of wireless technoloy that is proposed to mitigate spectrum saturation problem. İn cognitve radio, secondary user will use primary user's spectrum during primary user's absence without interupting primary user's transmission. This paper focuses on practical cognitive radio network development process using Android based smart phone for the data transmission. Energy detector based sensing method was proposed and used here because it doesnot require primary user's information. Bluetooth and Wi-fi are the two available types of spectrum that was sensed for CR detection. Simulation showed cognitive radio network can be developed using Android based smart phones. So, a complete application was developed using Java based Android Eclipse program. Finally, the application was uploaded and run on Android based smart phone to form and verify CR network for channel sensing and resource allocation. The observed efficiency of the application was around 81%.
Allocation of optimal distributed generation using GA for minimum ...
African Journals Online (AJOL)
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Keywords: distributed generation, line loss reduction, optimal location, radial .... performance depend on system operating conditions and the characteristics of the ..... Z matrix ij α , ij β are the loss coefficients represented as ji j i ji ij. VV r. /) cos(.
Optimal allocation of point-count sampling effort
Barker, R.J.; Sauer, J.R.; Link, W.A.
1993-01-01
Both unlimited and fixedradius point counts only provide indices to population size. Because longer count durations lead to counting a higher proportion of individuals at the point, proper design of these surveys must incorporate both count duration and sampling characteristics of population size. Using information about the relationship between proportion of individuals detected at a point and count duration, we present a method of optimizing a pointcount survey given a fixed total time for surveying and travelling between count points. The optimization can be based on several quantities that measure precision, accuracy, or power of tests based on counts, including (1) meansquare error of estimated population change; (2) mean-square error of average count; (3) maximum expected total count; or (4) power of a test for differences in average counts. Optimal solutions depend on a function that relates count duration at a point to the proportion of animals detected. We model this function using exponential and Weibull distributions, and use numerical techniques to conduct the optimization. We provide an example of the procedure in which the function is estimated from data of cumulative number of individual birds seen for different count durations for three species of Hawaiian forest birds. In the example, optimal count duration at a point can differ greatly depending on the quantities that are optimized. Optimization of the mean-square error or of tests based on average counts generally requires longer count durations than does estimation of population change. A clear formulation of the goals of the study is a critical step in the optimization process.
Institute of Scientific and Technical Information of China (English)
郭小雪; 秦勇
2012-01-01
传统的基于带宽请求的固定资源预留链路接入控制算法（BRLAC）不能适应网络状态和业务需求的变化，针对该类算法接入成功率和系统带宽利用率不高的问题，基于概率分析了系统预留带宽的大小，并提出一种动态带宽资源预留分配链路接入控制算法（DBRRA），该算法通过判断业务流优先级允许动态地从其他业务流调整预留带宽。仿真实验证明，DBRRA算法有较高的接入成功率、系统带宽利用率和较好的时延特性。%The traditional static resource reservation link access control algorithm based on bandwidth request can not adapt to the network state and business requirements, aiming at problems of low access success rate and low utilization ratio of bandwidth resource, the paper analyses the probability of bandwidth reservation, and proposes a link access control algorithm based on dynamic bandwidth resource reservation allocation. The algorithm allows adjusting bandwidth from other low level business traffic dynamically by judging the priority of business traffic. The experimental results demonstrate that the algorithm can improve the link access success proportion, system bandwidth utilization and have better delay character.
Directory of Open Access Journals (Sweden)
Xiangang Peng
2015-12-01
Full Text Available Distributed generation (DG systems are integral parts in future distribution networks. In this paper, a novel approach integrating crisscross optimization algorithm and Monte Carlo simulation (CSO-MCS is implemented to solve the optimal DG allocation (ODGA problem. The feature of applying CSO to address the ODGA problem lies in three interacting operators, namely horizontal crossover, vertical crossover and competitive operator. The horizontal crossover can search new solutions in a hypercube space with a larger probability while in the periphery of each hypercube with a decreasing probability. The vertical crossover can effectively facilitate those stagnant dimensions of a population to escape from premature convergence. The competitive operator allows the crisscross search to always maintain in a historical best position to quicken the converge rate. It is the combination of the double search strategies and competitive mechanism that enables CSO significant advantage in convergence speed and accuracy. Moreover, to deal with system uncertainties such as the output power of wind turbine and photovoltaic generators, an MCS-based method is adopted to solve the probabilistic power flow. The effectiveness of the CSO-MCS method is validated on the typical 33-bus and 69-bus test system, and results substantiate the suitability of CSO-MCS for multi-objective ODGA problem.
Institute of Scientific and Technical Information of China (English)
CAOJun; ZHANGYi-zhuo; YUEQi
2003-01-01
This paper introduced the Genetic Algorithms (GAs) and Artificial Neural Networks(ANNs),which have been widely used in optimization of allocating.The combinationg way of the two optimizing algorithms was used in board allocating of fumiture production.In the experiment,the rectangular flake board of 3650mm×1850mm was used as raw material to allocate 100 sets of Table Bucked.The utilizing rate of the board reached 94.14% and the calculating time was only 35s.The experiment result proofed that the method by using the GA for optimizing the weights of the ANN can raise the utilizing rate of the board and can shorten the time of the design.At the same time,this method can simultaneously searched in many directions,thus greatly increasing the probability of finding a global optimum.
Optimal power allocation for homogeneous and heterogeneous CA-MIMO systems
Institute of Scientific and Technical Information of China (English)
CUI QiMei; KANG PeiChuan; HUANG XueQing; VALKAMA Mikko; NIEMELA Jarno
2013-01-01
Carrier aggregation （CA） technique has been adopted by 3GPP LTE-Advanced due to its ability of enhancing the spectrum efficiency and peak data rates through aggregating multiple component carriers （CCs）. Two main factors make power control optimization very essential for CA-MIMO radio link： the different channel characteristics in multiple CCs, and multiple power constraint conditions （per-CC, per-antenna and pertransmitter power constraints） in the actual CA system deployment. This paper firstly derives the degenerate conditions of optimal power allocation for a single-transmitter CA-MIMO system. Stemming from the derived degenerate conditions, we propose a modified hybrid gradient optimal power allocation（MHGOPA） algorithm to maximize the system performance. Simulation results verify the validity of the proposed resource allocation approach by comparing with baseline average power allocation algorithm. Finally, we extend the MHGOPA algorithm into a heterogeneous CA network with multiple transmitters working simultaneously.
A Heuristic Optimal Discrete Bit Allocation Algorithm for Margin Maximization in DMT Systems
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Dong Shi-Wei
2007-01-01
Full Text Available A heuristic optimal discrete bit allocation algorithm is proposed for solving the margin maximization problem in discrete multitone (DMT systems. Starting from an initial equal power assignment bit distribution, the proposed algorithm employs a multistaged bit rate allocation scheme to meet the target rate. If the total bit rate is far from the target rate, a multiple-bits loading procedure is used to obtain a bit allocation close to the target rate. When close to the target rate, a parallel bit-loading procedure is used to achieve the target rate and this is computationally more efficient than conventional greedy bit-loading algorithm. Finally, the target bit rate distribution is checked, if it is efficient, then it is also the optimal solution; else, optimal bit distribution can be obtained only by few bit swaps. Simulation results using the standard asymmetric digital subscriber line (ADSL test loops show that the proposed algorithm is efficient for practical DMT transmissions.
Optimal relay selection and power allocation for cognitive two-way relaying networks
Pandarakkottilil, Ubaidulla
2012-06-01
In this paper, we present an optimal scheme for power allocation and relay selection in a cognitive radio network where a pair of cognitive (or secondary) transceiver nodes communicate with each other assisted by a set of cognitive two-way relays. The secondary nodes share the spectrum with a licensed primary user (PU), and each node is assumed to be equipped with a single transmit/receive antenna. The interference to the PU resulting from the transmission from the cognitive nodes is kept below a specified limit. We propose joint relay selection and optimal power allocation among the secondary user (SU) nodes achieving maximum throughput under transmit power and PU interference constraints. A closed-form solution for optimal allocation of transmit power among the SU transceivers and the SU relay is presented. Furthermore, numerical simulations and comparisons are presented to illustrate the performance of the proposed scheme. © 2012 IEEE.
Optimal allocation of building blocks between nutrient uptake systems in a microbe.
van den Berg, Hugo A; Kiselev, Yuri N; Orlov, Michael V
2002-03-01
A bacterial cell must distribute its molecular building blocks among various types of nutrient uptake systems. If the microbe is to maximize its average growth rate, this allocation of building blocks must be adjusted to the environmental availabilities of the various nutrients. The adjustments can be found from growth balancing considerations. We give a full proof of optimality and uniqueness of the optimal allocation regime for a simple model of microbial growth and internal stores kinetics. This proof suggests likely candidates for optimal control regimes in the case of a more realistic model. These candidate regimes differ with respect to the information that the cell's control system must have access to. We pay particular attention to one of the three candidates, a feedback regime based on a cellular control system that monitors only internal reserve densities. We show that allocation converges rapidly to balanced growth under this control regime.
A Methodology to Exploit Profit Allocation in Logistics Joint Distribution Network Optimization
Directory of Open Access Journals (Sweden)
Yong Wang
2015-01-01
Full Text Available Logistics joint distribution network (LJDN optimization involves vehicle routes scheduling and profit allocation for multiple distribution centers. This is essentially a combinational and cooperative game optimization problem seeking to serve a number of customers with a fleet of vehicles and allocate profit among multiple centers. LJDN routing optimization based on customer clustering units can alleviate the computational complexity and improve the calculation accuracy. In addition, the profit allocation mechanism can be realized based on cooperative game theory through a negotiation procedure by the Logistics Service Provider (LSP. This paper establishes a model to minimize the total cost of the multiple centers joint distribution network when each distribution center is assigned to serve a series of distribution units. An improved particle swarm optimization (PSO algorithm is presented to tackle the model formulation by assigning distribution centers (DCs to distribution units. Improved PSO algorithm combines merits of PSO algorithm and genetic algorithm (GA with global and local search capabilities. Finally, a Shapley value model based on cooperative game theory is proposed to obtain the optimal profit allocation strategy among distribution centers from nonempty coalitions. The computational results from a case study in Guiyang city, China, suggest the optimal sequential coalition of distribution centers can be achieved according to Strictly Monotonic Path (SMP.
Biometric Quantization through Detection Rate Optimized Bit Allocation
Chen, C.; Veldhuis, R.N.J.; Kevenaar, T.A.M.; Akkermans, A.H.M.
2009-01-01
Extracting binary strings from real-valued biometric templates is a fundamental step in many biometric template protection systems, such as fuzzy commitment, fuzzy extractor, secure sketch, and helper data systems. Previous work has been focusing on the design of optimal quantization and coding for
On the Optimal Allocation of R&D Resources for Climate Change Technology Development
Energy Technology Data Exchange (ETDEWEB)
Blanford, G J; Clarke, L E
2003-11-03
While technology studies and integrated assessment models incorporating endogenous technological change have demonstrated that advancing technology is a crucial component of an optimal greenhouse gas abatement strategy, the R&D process itself has received little analytical attention. This paper presents a conceptual framework for considering and exploring the optimal allocation of R&D resources for climate change technology development. The framework is then applied to a stylized application that considers the allocation between R&D focused on resolving uncertainties about the retention of sequestration and R&D focused on improving the performance of renewable energy technologies.
Directory of Open Access Journals (Sweden)
Ning Zhao
2015-01-01
Full Text Available Storage allocation of outbound containers is a key factor of the performance of container handling system in automated container terminals. Improper storage plans of outbound containers make QC waiting inevitable; hence, the vessel handling time will be lengthened. A simulation-based optimization method is proposed in this paper for the storage allocation problem of outbound containers in automated container terminals (SAPOBA. A simulation model is built up by Timed-Colored-Petri-Net (TCPN, used to evaluate the QC waiting time of storage plans. Two optimization approaches, based on Particle Swarm Optimization (PSO and Genetic Algorithm (GA, are proposed to form the complete simulation-based optimization method. Effectiveness of this method is verified by experiment, as the comparison of the two optimization approaches.
An improved model for the oPtImal Measurement Probes Allocation tool
Energy Technology Data Exchange (ETDEWEB)
Sterle, C., E-mail: claudio.sterle@unina.it [Consorzio CREATE/Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Neto, A.C. [Fusion for Energy, 08019 Barcelona (Spain); De Tommasi, G. [Consorzio CREATE/Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy)
2015-10-15
Highlights: • The problem of optimally allocating the probes of a diagnostic system is tackled. • The problem is decomposed in two consecutive optimization problems. • Two original ILP models are proposed and sequentially solved to optimality. • The proposed ILP models improve and extend the previous work present in literature. • Real size instances have been optimally solved with very low computation time. - Abstract: The oPtImal Measurement Probes Allocation (PIMPA) tool has been recently proposed in [1] to maximize the reliability of a tokamak diagnostic system against the failure of one or more of the processing nodes. PIMPA is based on the solution of integer linear programming (ILP) problems, and it minimizes the effect of the failure of a data acquisition component. The first formulation of the PIMPA model did not support the concept of individual slots. This work presents an improved ILP model that addresses the above mentioned problem, by taking into account all the individual probes.
Optimal reserve capacity allocation with consideration of customer reliability requirements
Energy Technology Data Exchange (ETDEWEB)
Najafi, M. [Department of Engineering, Islamic Azad University, Science and Research Branch, Tehran (Iran); Ehsan, M.; Fotuhi-Firuzabad, M. [Department of Electrical Engineering, Sharif University of Technology, Tehran (Iran); Akhavein, A. [Department of Engineering, Islamic Azad University, Tehran South Branch (Iran); Afshar, K. [Department of Electrical Engineering, Imam Khomeini International University, Qazvin (Iran)
2010-09-15
An algorithm for determining optimal reserve capacity in a power market is presented in this paper. Optimization process in the proposed algorithm is based on the cost-benefit trade off. Market clearance is executed with consideration of uncertainties of power system components in an aggregated environment. It is assumed that both generating units and interruptible loads participate in the reserve market. In addition, customers' reliability requirements are considered as constraints for decision making process of ISO. The rendered method considers random outages of generating units and transmission lines and determined outage of interruptible loads and employs Monte Carlo Simulation (MCS) for scenarios generation. Unlike previous methods in which a constant value is assumed for cost of the energy not supplied, a flexible value for this parameter is applied which shows an important effect in the evaluation results. The performance of the proposed method has been examined on the IEEE-Reliability Test System (IEEE-RTS). (author)
On measuring the sensitivity of the optimal portfolio allocation
Iwona Konarzewska
2008-01-01
In this paper we consider the sensitivity problem connected with portfolio optimization results when different measures of risk such as portfolio rates of return standard deviation, portfolio VaR, CVaR are minimized. Conditioning the data (represented by spectral condition index of the rates of return correlation matrix) plays, as it is shown, a crucial role in describing the properties of the models. We report on the research conducted for 13 largest firms on Warsaw Stock Exchange.
Optimal resource allocation in General Cournot-competitive equilibrium
Sommerfelt Ervik, Inger; Soegaard, Christian
2013-01-01
Conventional economic theory stipulates that output in Cournot competition is too low relative to that which is attained in perfect competition. We revisit this result in a General Cournot-competitive Equilibrium model with two industries that differ only in terms of productivity. We show that in general equilibrium, the more efficient industry produces too little and the less efficient industry produces too much compared to an optimal scenario with perfect competition.
Optimal allocation of resources in a biomarker setting.
Rosner, Bernard; Hendrickson, Sara; Willett, Walter
2015-01-30
Nutrient intake is often measured with substantial error both in commonly used surrogate instruments such as a food frequency questionnaire (FFQ) and in gold standard-type instruments such as a diet record (DR). If there is a correlated error between the FFQ and DR, then standard measurement error correction methods based on regression calibration can produce biased estimates of the regression coefficient (λ) of true intake on surrogate intake. However, if a biomarker exists and the error in the biomarker is independent of the error in the FFQ and DR, then the method of triads can be used to obtain unbiased estimates of λ, provided that there are replicate biomarker data on at least a subsample of validation study subjects. Because biomarker measurements are expensive, for a fixed budget, one can use a either design where a large number of subjects have one biomarker measure and only a small subsample is replicated or a design that has a smaller number of subjects and has most or all subjects validated. The purpose of this paper is to optimize the proportion of subjects with replicated biomarker measures, where optimization is with respect to minimizing the variance of ln(λ̂). The methodology is illustrated using vitamin C intake data from the European Prospective Investigation into Cancer and Nutrition study where plasma vitamin C is the biomarker. In this example, the optimal validation study design is to have 21% of subjects with replicated biomarker measures.
Directory of Open Access Journals (Sweden)
Y. Zeng
2016-06-01
Full Text Available The optimization of land-use allocation is one of important approaches to achieve regional sustainable development. This study selects Chang-Zhu-Tan agglomeration as study area and proposed a new land use optimization allocation model. Using multi-agent based simulation model, the future urban land use optimization allocation was simulated in 2020 and 2030 under three different scenarios. This kind of quantitative information about urban land use optimization allocation and urban expansions in future would be of great interest to urban planning, water and land resource management, and climate change research.
Zeng, Y.; Huang, W.; Jin, W.; Li, S.
2016-06-01
The optimization of land-use allocation is one of important approaches to achieve regional sustainable development. This study selects Chang-Zhu-Tan agglomeration as study area and proposed a new land use optimization allocation model. Using multi-agent based simulation model, the future urban land use optimization allocation was simulated in 2020 and 2030 under three different scenarios. This kind of quantitative information about urban land use optimization allocation and urban expansions in future would be of great interest to urban planning, water and land resource management, and climate change research.
Optimization Analysis of Supply Chain Resource Allocation in Customized Online Shopping Service Mode
Directory of Open Access Journals (Sweden)
Jianming Yao
2015-01-01
Full Text Available For an online-shopping company, whether it can provide its customers with customized service is the key to enhance its customers’ experience value and its own competence. A good customized service requires effective integration and reasonable allocation of the company’s supply chain resources running in the background. Based on the analysis of the allocation of supply chain resources in the customized online shopping service mode and its operational characteristics, this paper puts forward an optimization model for the resource allocation and builds an improved ant algorithm to solve it. Finally, the effectiveness and feasibility of the optimization method and algorithm are demonstrated by a numerical simulation. This paper finds that the special online shopping environments lead to many dynamic and uncertain characters of the service demands. Different customized service patterns and their combination patterns should match with different supply chain resource allocations. The optimization model not only reflects the required service cost and delivery time in the objective function, but also considers the service scale effect optimization and the relations of integration benefits and risks. The improved ant algorithm has obvious advantages in flexibly balancing the multiobjective optimizations, adjusting the convergence speed, and adjusting the operation parameters.
Network Optimization Models for Resource Allocation in Developing Military Countermeasures
2011-06-07
authors including [1], [4], [10] and [13]. In particular, RCSP problems of limited size can be solved through special-purpose algorithms such as those...developed in [3] and [7], or through efficient general-purpose algorithms available in commercial optimization software packages. 2 To demonstrate the...a3)3(d2,a2) (a2,0) 4 (an,0) 2n-1 2n (0,0) (dn,an) 2(n-1)…. ÷ ø ö ç è æ 0,2 s a ÷ ø ö ç è æ 0,3 s a ÷ ø ö ç è æ 0,4 s a ( ) i ii i i i stt s a
Node ordinal encoded genetic algorithm for the optimal allocation of water resources
Institute of Scientific and Technical Information of China (English)
YANG Xiaohua; YANG Zhifeng; SHEN Zhenyao; LI Jianqiang
2005-01-01
A new method, node ordinal encoded genetic algorithm (NOEGA), is proposed for solving water resources optimal allocation problems, in which the capacity of water resources is split into a number of smaller parts so that successive operations can be overlapped. Our objective is to maximize the whole benefit function. To overcome the "dimensionality and algorithm complexity curse" while searching for solutions and looking for an optimal solution, the operations of one-point crossover operator, gene exchange operator, gene random operator, gene shift operator and node ordinal strings are established. It is proved to be an effective optimal method in searching for global solutions. The NOEGA does not need a diversity of initial population, and it does not have the problem of immature convergence. The results of two cases show that using NOEGA to solve the optimal allocation model is very efficient and robust. In addition, the algorithm complexity of NOEGA is discussed.
Grafton, R. Quentin; Chu, Hoang Long; Stewardson, Michael; Kompas, Tom
2011-12-01
A key challenge in managing semiarid basins, such as in the Murray-Darling in Australia, is to balance the trade-offs between the net benefits of allocating water for irrigated agriculture, and other uses, versus the costs of reduced surface flows for the environment. Typically, water planners do not have the tools to optimally and dynamically allocate water among competing uses. We address this problem by developing a general stochastic, dynamic programming model with four state variables (the drought status, the current weather, weather correlation, and current storage) and two controls (environmental release and irrigation allocation) to optimally allocate water between extractions and in situ uses. The model is calibrated to Australia's Murray River that generates: (1) a robust qualitative result that "pulse" or artificial flood events are an optimal way to deliver environmental flows over and above conveyance of base flows; (2) from 2001 to 2009 a water reallocation that would have given less to irrigated agriculture and more to environmental flows would have generated between half a billion and over 3 billion U.S. dollars in overall economic benefits; and (3) water markets increase optimal environmental releases by reducing the losses associated with reduced water diversions.
J. Daníelsson (Jón); B.N. Jorgensen (Bjørn); C.G. de Vries (Casper); X. Yang (Xiaoguang)
2001-01-01
textabstractWe derive, in a complete markets environment, an investor's optimal portfolio allocation subject to both a budget constraint and a probabilistic risk constraint. We demonstrate that the set of feasible portfolios need not be connected or convex, while the number of local optima increases
Optimally Joint Subcarrier Matching and Power Allocation in OFDM Multihop System
Directory of Open Access Journals (Sweden)
Shuyuan Yang
2008-04-01
Full Text Available Orthogonal frequency division multiplexing (OFDM multihop system is a promising way to increase capacity and coverage. In this paper, we propose an optimally joint subcarrier matching and power allocation scheme to further maximize the total channel capacity with the constrained total system power. First, the problem is formulated as a mixed binary integer programming problem, which is prohibitive to find the global optimum in terms of complexity. Second, by making use of the equivalent channel power gain for any matched subcarrier pair, a low complexity scheme is proposed. The optimal subcarrier matching is to match subcarriers by the order of the channel power gains. The optimal power allocation among the matched subcarrier pairs is water-filling. An analytical argument is given to prove that the two steps achieve the optimally joint subcarrier matching and power allocation. The simulation results show that the proposed scheme achieves the largest total channel capacity as compared to the other schemes, where there is no subcarrier matching or no power allocation.
Optimally Joint Subcarrier Matching and Power Allocation in OFDM Multihop System
Directory of Open Access Journals (Sweden)
Wang Wenyi
2008-01-01
Full Text Available Orthogonal frequency division multiplexing (OFDM multihop system is a promising way to increase capacity and coverage. In this paper, we propose an optimally joint subcarrier matching and power allocation scheme to further maximize the total channel capacity with the constrained total system power. First, the problem is formulated as a mixed binary integer programming problem, which is prohibitive to find the global optimum in terms of complexity. Second, by making use of the equivalent channel power gain for any matched subcarrier pair, a low complexity scheme is proposed. The optimal subcarrier matching is to match subcarriers by the order of the channel power gains. The optimal power allocation among the matched subcarrier pairs is water-filling. An analytical argument is given to prove that the two steps achieve the optimally joint subcarrier matching and power allocation. The simulation results show that the proposed scheme achieves the largest total channel capacity as compared to the other schemes, where there is no subcarrier matching or no power allocation.
J. Danielsson; B.N. Jorgensen (Bjørn); C.G. de Vries (Casper); X. Yang (Xiaoguang)
2001-01-01
textabstractWe derive, in a complete markets environment, an investor's optimal portfolio allocation subject to both a budget constraint and a probabilistic risk constraint. We demonstrate that the set of feasible portfolios need not be connected or convex, while the number of local optima increases
Optimizing Irrigation Water Allocation under Multiple Sources of Uncertainty in an Arid River Basin
Wei, Y.; Tang, D.; Gao, H.; Ding, Y.
2015-12-01
Population growth and climate change add additional pressures affecting water resources management strategies for meeting demands from different economic sectors. It is especially challenging in arid regions where fresh water is limited. For instance, in the Tailanhe River Basin (Xinjiang, China), a compromise must be made between water suppliers and users during drought years. This study presents a multi-objective irrigation water allocation model to cope with water scarcity in arid river basins. To deal with the uncertainties from multiple sources in the water allocation system (e.g., variations of available water amount, crop yield, crop prices, and water price), the model employs a interval linear programming approach. The multi-objective optimization model developed from this study is characterized by integrating eco-system service theory into water-saving measures. For evaluation purposes, the model is used to construct an optimal allocation system for irrigation areas fed by the Tailan River (Xinjiang Province, China). The objective functions to be optimized are formulated based on these irrigation areas' economic, social, and ecological benefits. The optimal irrigation water allocation plans are made under different hydroclimate conditions (wet year, normal year, and dry year), with multiple sources of uncertainty represented. The modeling tool and results are valuable for advising decision making by the local water authority—and the agricultural community—especially on measures for coping with water scarcity (by incorporating uncertain factors associated with crop production planning).
Optimized Switch Allocation to Improve the Restoration Energy in Distribution Systems
Dezaki, Hamed H.; Abyaneh, Hossein A.; Agheli, Ali; Mazlumi, Kazem
2012-01-01
In distribution networks switching devices play critical role in energy restoration and improving reliability indices. This paper presents a novel objective function to optimally allocate switches in electric power distribution systems. Identifying the optimized location of the switches is a nonlinear programming problem (NLP). In the proposed objective function a new auxiliary function is used to simplify the calculation of the objective function. The output of the auxiliary function is binary. The genetic algorithm (GA) optimization method is used to solve this optimization problem. The proposed method is applied to a real distribution network and the results reveal that the method is successful.
Directory of Open Access Journals (Sweden)
Bo Yang, Lingen Chen, Fengrui Sun
2011-03-01
Full Text Available Finite time exergoeconomic performance of an endoreversible intercooled regenerative Brayton cogeneration plant is optimized based on the model which is established using finite time thermodynamic in Part 1 of this paper. It is found that the optimal heat conductance allocation of the regenerator is zero. When the total pressure ratio and the heat conductance allocation of the regenerator are fixed, it is shown that there exist an optimal intercooling pressure ratio, and a group of optimal heat conductance allocations among the hot-, cold- and consumer-side heat exchangers and the intercooler, which correspond to a maximum dimensionless profit rate. When the total pressure ratio is variable, there exists an optimal total pressure ratio which corresponds to a double-maximum dimensionless profit rate, and the corresponding exergetic efficiency is obtained. The effects of the total heat exchanger conductance, price ratios and the consumer-side temperature on the double-maximum dimensionless profit rate and the corresponding exergetic efficiency are discussed. It is found that there exists an optimal consumer-side temperature which corresponds to a thrice-maximum dimensionless profit rate.
Optimizing MPBSM Resource Allocation Based on Revenue Management: A China Mobile Sichuan Case
Directory of Open Access Journals (Sweden)
Xu Chen
2015-01-01
Full Text Available The key to determining the network service level of telecom operators is resource allocation for mobile phone base station maintenance (MPBSM. Given intense market competition and higher consumer requirements for network service levels, an increasing proportion of resources have been allocated to MPBSM. Maintenance costs account for the rising fraction of direct costs, and the management of MPBSM resource allocation presents special challenges to telecom operators. China Mobile is the largest telecom operator in the world. Its subsidiary, China Mobile Sichuan, is the first in China to use revenue management in improving MPBSM resource allocation. On the basis of comprehensive revenue (including both economic revenue and social revenue, the subsidiary established a classification model of its base stations. The model scientifically classifies more than 25,000 base stations according to comprehensive revenue. China Mobile Sichuan also conducted differentiation allocation of MPBSM resources on the basis of the classification results. Furthermore, it optimized the assessment system of the telecom base stations to establish an assurance system for the use of MPBSM resources. After half-year implementation, the cell availability of both VIP base stations and total base stations significantly improved. The optimization also reduced economic losses to RMB 10.134 million, and enhanced customer satisfaction with network service by 3.2%.
Lu, Mengqian; Lall, Upmanu; Robertson, Andrew W.; Cook, Edward
2017-03-01
Streamflow forecasts at multiple time scales provide a new opportunity for reservoir management to address competing objectives. Market instruments such as forward contracts with specified reliability are considered as a tool that may help address the perceived risk associated with the use of such forecasts in lieu of traditional operation and allocation strategies. A water allocation process that enables multiple contracts for water supply and hydropower production with different durations, while maintaining a prescribed level of flood risk reduction, is presented. The allocation process is supported by an optimization model that considers multitime scale ensemble forecasts of monthly streamflow and flood volume over the upcoming season and year, the desired reliability and pricing of proposed contracts for hydropower and water supply. It solves for the size of contracts at each reliability level that can be allocated for each future period, while meeting target end of period reservoir storage with a prescribed reliability. The contracts may be insurable, given that their reliability is verified through retrospective modeling. The process can allow reservoir operators to overcome their concerns as to the appropriate skill of probabilistic forecasts, while providing water users with short-term and long-term guarantees as to how much water or energy they may be allocated. An application of the optimization model to the Bhakra Dam, India, provides an illustration of the process. The issues of forecast skill and contract performance are examined. A field engagement of the idea is useful to develop a real-world perspective and needs a suitable institutional environment.
Directory of Open Access Journals (Sweden)
Xiao-feng Xu
2017-01-01
Full Text Available Collaborative logistics network resource allocation can effectively meet the needs of customers. It can realize the overall benefit maximization of the logistics network and ensure that collaborative logistics network runs orderly at the time of creating value. Therefore, this article is based on the relationship of collaborative logistics network supplier, the transit warehouse, and sellers, and we consider the uncertainty of time to establish a bilevel programming model with random constraints and propose a genetic simulated annealing hybrid intelligent algorithm to solve it. Numerical example shows that the method has stronger robustness and convergence; it can achieve collaborative logistics network resource allocation rationalization and optimization.
Artificial intelligent techniques for optimizing water allocation in a reservoir watershed
Chang, Fi-John; Chang, Li-Chiu; Wang, Yu-Chung
2014-05-01
This study proposes a systematical water allocation scheme that integrates system analysis with artificial intelligence techniques for reservoir operation in consideration of the great uncertainty upon hydrometeorology for mitigating droughts impacts on public and irrigation sectors. The AI techniques mainly include a genetic algorithm and adaptive-network based fuzzy inference system (ANFIS). We first derive evaluation diagrams through systematic interactive evaluations on long-term hydrological data to provide a clear simulation perspective of all possible drought conditions tagged with their corresponding water shortages; then search the optimal reservoir operating histogram using genetic algorithm (GA) based on given demands and hydrological conditions that can be recognized as the optimal base of input-output training patterns for modelling; and finally build a suitable water allocation scheme through constructing an adaptive neuro-fuzzy inference system (ANFIS) model with a learning of the mechanism between designed inputs (water discount rates and hydrological conditions) and outputs (two scenarios: simulated and optimized water deficiency levels). The effectiveness of the proposed approach is tested on the operation of the Shihmen Reservoir in northern Taiwan for the first paddy crop in the study area to assess the water allocation mechanism during drought periods. We demonstrate that the proposed water allocation scheme significantly and substantially avails water managers of reliably determining a suitable discount rate on water supply for both irrigation and public sectors, and thus can reduce the drought risk and the compensation amount induced by making restrictions on agricultural use water.
Directory of Open Access Journals (Sweden)
Rong Chai
2017-01-01
Full Text Available In recent years, heterogeneous radio access technologies have experienced rapid development and gradually achieved effective coordination and integration, resulting in heterogeneous networks (HetNets. In this paper, we consider the downlink secure transmission of HetNets where the information transmission from base stations (BSs to legitimate users is subject to the interception of eavesdroppers. In particular, we stress the problem of joint user association and power allocation of the BSs. To achieve data transmission in a secure and energy efficient manner, we introduce the concept of secrecy energy efficiency which is defined as the ratio of the secrecy transmission rate and power consumption of the BSs and formulate the problem of joint user association and power allocation as an optimization problem which maximizes the joint secrecy energy efficiency of all the BSs under the power constraint of the BSs and the minimum data rate constraint of user equipment (UE. By equivalently transforming the optimization problem into two subproblems, that is, power allocation subproblem and user association subproblem of the BSs, and applying iterative method and Kuhn-Munkres (K-M algorithm to solve the two subproblems, respectively, the optimal user association and power allocation strategies can be obtained. Numerical results demonstrate that the proposed algorithm outperforms previously proposed algorithms.
Rate distortion optimal bit allocation methods for volumetric data using JPEG 2000.
Kosheleva, Olga M; Usevitch, Bryan E; Cabrera, Sergio D; Vidal, Edward
2006-08-01
Computer modeling programs that generate three-dimensional (3-D) data on fine grids are capable of generating very large amounts of information. These data sets, as well as 3-D sensor/measured data sets, are prime candidates for the application of data compression algorithms. A very flexible and powerful compression algorithm for imagery data is the newly released JPEG 2000 standard. JPEG 2000 also has the capability to compress volumetric data, as described in Part 2 of the standard, by treating the 3-D data as separate slices. As a decoder standard, JPEG 2000 does not describe any specific method to allocate bits among the separate slices. This paper proposes two new bit allocation algorithms for accomplishing this task. The first procedure is rate distortion optimal (for mean squared error), and is conceptually similar to postcompression rate distortion optimization used for coding codeblocks within JPEG 2000. The disadvantage of this approach is its high computational complexity. The second bit allocation algorithm, here called the mixed model (MM) approach, mathematically models each slice's rate distortion curve using two distinct regions to get more accurate modeling at low bit rates. These two bit allocation algorithms are applied to a 3-D Meteorological data set. Test results show that the MM approach gives distortion results that are nearly identical to the optimal approach, while significantly reducing computational complexity.
Institute of Scientific and Technical Information of China (English)
张云鹤; 朱艳琴; 纪其进
2013-01-01
Unreasonable allocation of originally scarce bandwidth was a severe problem in the P2P content distribution networks. To solve the problem and suppress the node’s selfishness, an auction-based bandwidth allocation mechanism for P2P networks was proposed. Through the effective bandwidth payment scheme, the selfish nodes had no incentives to lie and provided the real bandwidth requirements. Also the “tragedy of the commons” could be avoided by the nodes’ healthy bandwidth competition. To adapt to the distributed nature of the P2P networks, the algorithm was implemented in parallel at resource providing nodes and request nodes. Simulation results show that the scheme not only suppresses free riding nodes efficiently in the system, but also shortens the average completion time for content distribution and decreas-es the ratio of data uploaded by the source server.% 为了解决 P2P 内容分发网络中带宽资源稀缺且分配不合理这一突出问题，抑制节点的自私性行为，设计了一种基于拍卖的带宽分配机制。该机制通过上载带宽支付方式，迫使自私请求节点选择合适的带宽需求，使得整个 P2P 网络中的节点良性竞争带宽资源，避免了“公共地悲剧”的发生；且带宽分配算法在资源节点和请求节点并行执行，能很好适应 P2P 网络的分布式特性。仿真结果表明，该机制能够有效遏制搭便车行为，从而缩短P2P 内容分发的平均完成时间，降低内容源服务器的上传数据比例。
Directory of Open Access Journals (Sweden)
Luman Zhao
2015-01-01
Full Text Available A thrust allocation method was proposed based on a hybrid optimization algorithm to efficiently and dynamically position a semisubmersible drilling rig. That is, the thrust allocation was optimized to produce the generalized forces and moment required while at the same time minimizing the total power consumption under the premise that forbidden zones should be taken into account. An optimization problem was mathematically formulated to provide the optimal thrust allocation by introducing the corresponding design variables, objective function, and constraints. A hybrid optimization algorithm consisting of a genetic algorithm and a sequential quadratic programming (SQP algorithm was selected and used to solve this problem. The proposed method was evaluated by applying it to a thrust allocation problem for a semisubmersible drilling rig. The results indicate that the proposed method can be used as part of a cost-effective strategy for thrust allocation of the rig.
Optimal Resource Allocation under Fair QoS in Multi-tier Server Systems
Akai, Hirokazu; Ushio, Toshimitsu; Hayashi, Naoki
Recent development of network technology realizes multi-tier server systems, where several tiers perform functionally different processing requested by clients. It is an important issue to allocate resources of the systems to clients dynamically based on their current requests. On the other hand, Q-RAM has been proposed for resource allocation in real-time systems. In the server systems, it is important that execution results of all applications requested by clients are the same QoS(quality of service) level. In this paper, we extend Q-RAM to multi-tier server systems and propose a method for optimal resource allocation with fairness of the QoS levels of clients’ requests. We also consider an assignment problem of physical machines to be sleep in each tier sothat the energy consumption is minimized.
DEFF Research Database (Denmark)
Mazziotta, Adriano; Montesino Pouzols, Federico; Mönkkönen, Mikko
2016-01-01
that in boreal forest set-aside followed by protection of clear-cuts can become a winning cost-effective strategy when accounting for habitat requirements of multiple species, long planning horizon, and limited budget. It is particularly effective when adopting a long-term sustainability perspective......, and accounting for present revenues from timber harvesting. The present analysis assesses the cost-effective conditions to allocate resources into an inexpensive conservation strategy that nevertheless has potential to produce high ecological values in the future.......Resource allocation to multiple alternative conservation actions is a complex task. A common trade-off occurs between protection of smaller, expensive, high-quality areas versus larger, cheaper, partially degraded areas. We investigate optimal allocation into three actions in boreal forest: current...
Distributive Stochastic Learning for Delay-Optimal OFDMA Power and Subband Allocation
Cui, Ying
2010-01-01
In this paper, we consider the distributive queue-aware power and subband allocation design for a delay-optimal OFDMA uplink system with one base station, $K$ users and $N_F$ independent subbands. Each mobile has an uplink queue with heterogeneous packet arrivals and delay requirements. We model the problem as an infinite horizon average reward Markov Decision Problem (MDP) where the control actions are functions of the instantaneous Channel State Information (CSI) as well as the joint Queue State Information (QSI). To address the distributive requirement and the issue of exponential memory requirement and computational complexity, we approximate the subband allocation Q-factor by the sum of the per-user subband allocation Q-factor and derive a distributive online stochastic learning algorithm to estimate the per-user Q-factor and the Lagrange multipliers (LM) simultaneously and determine the control actions using an auction mechanism. We show that under the proposed auction mechanism, the distributive online...
Eyono Obono, S. D.; Basak, Sujit Kumar
2011-12-01
The general formulation of the assignment problem consists in the optimal allocation of a given set of tasks to a workforce. This problem is covered by existing literature for different domains such as distributed databases, distributed systems, transportation, packets radio networks, IT outsourcing, and teaching allocation. This paper presents a new version of the assignment problem for the allocation of academic tasks to staff members in departments with long leave opportunities. It presents the description of a workload allocation scheme and its algorithm, for the allocation of an equitable number of tasks in academic departments where long leaves are necessary.
Optimal allocation of the limited oral cholera vaccine supply between endemic and epidemic settings.
Moore, Sean M; Lessler, Justin
2015-10-06
The World Health Organization (WHO) recently established a global stockpile of oral cholera vaccine (OCV) to be preferentially used in epidemic response (reactive campaigns) with any vaccine remaining after 1 year allocated to endemic settings. Hence, the number of cholera cases or deaths prevented in an endemic setting represents the minimum utility of these doses, and the optimal risk-averse response to any reactive vaccination request (i.e. the minimax strategy) is one that allocates the remaining doses between the requested epidemic response and endemic use in order to ensure that at least this minimum utility is achieved. Using mathematical models, we find that the best minimax strategy is to allocate the majority of doses to reactive campaigns, unless the request came late in the targeted epidemic. As vaccine supplies dwindle, the case for reactive use of the remaining doses grows stronger. Our analysis provides a lower bound for the amount of OCV to keep in reserve when responding to any request. These results provide a strategic context for the fulfilment of requests to the stockpile, and define allocation strategies that minimize the number of OCV doses that are allocated to suboptimal situations. © 2015 The Authors.
Optimal allocation of the limited oral cholera vaccine supply between endemic and epidemic settings
Moore, Sean M.; Lessler, Justin
2015-01-01
The World Health Organization (WHO) recently established a global stockpile of oral cholera vaccine (OCV) to be preferentially used in epidemic response (reactive campaigns) with any vaccine remaining after 1 year allocated to endemic settings. Hence, the number of cholera cases or deaths prevented in an endemic setting represents the minimum utility of these doses, and the optimal risk-averse response to any reactive vaccination request (i.e. the minimax strategy) is one that allocates the remaining doses between the requested epidemic response and endemic use in order to ensure that at least this minimum utility is achieved. Using mathematical models, we find that the best minimax strategy is to allocate the majority of doses to reactive campaigns, unless the request came late in the targeted epidemic. As vaccine supplies dwindle, the case for reactive use of the remaining doses grows stronger. Our analysis provides a lower bound for the amount of OCV to keep in reserve when responding to any request. These results provide a strategic context for the fulfilment of requests to the stockpile, and define allocation strategies that minimize the number of OCV doses that are allocated to suboptimal situations. PMID:26423441
Chauvenet, Aliénor L M; Baxter, Peter W J; McDonald-Madden, Eve; Possingham, Hugh P
2010-04-01
Money is often a limiting factor in conservation, and attempting to conserve endangered species can be costly. Consequently, a framework for optimizing fiscally constrained conservation decisions for a single species is needed. In this paper we find the optimal budget allocation among isolated subpopulations of a threatened species to minimize local extinction probability. We solve the problem using stochastic dynamic programming, derive a useful and simple alternative guideline for allocating funds, and test its performance using forward simulation. The model considers subpopulations that persist in habitat patches of differing quality, which in our model is reflected in different relationships between money invested and extinction risk. We discover that, in most cases, subpopulations that are less efficient to manage should receive more money than those that are more efficient to manage, due to higher investment needed to reduce extinction risk. Our simple investment guideline performs almost as well as the exact optimal strategy. We illustrate our approach with a case study of the management of the Sumatran tiger, Panthera tigris sumatrae, in Kerinci Seblat National Park (KSNP), Indonesia. We find that different budgets should be allocated to the separate tiger subpopulations in KSNP. The subpopulation that is not at risk of extinction does not require any management investment. Based on the combination of risks of extinction and habitat quality, the optimal allocation for these particular tiger subpopulations is an unusual case: subpopulations that occur in higher-quality habitat (more efficient to manage) should receive more funds than the remaining subpopulation that is in lower-quality habitat. Because the yearly budget allocated to the KSNP for tiger conservation is small, to guarantee the persistence of all the subpopulations that are currently under threat we need to prioritize those that are easier to save. When allocating resources among subpopulations
Directory of Open Access Journals (Sweden)
Rodrigo Palma-Behnke
2013-01-01
Full Text Available A novel optimization methodology consisting of finding the near optimal location of wind turbines (WTs on a planned transmission network in a secure and cost-effective way is presented on this paper. While minimizing the investment costs of WTs, the algorithm allocates the turbines so that a desired wind power energy-penetration level is reached. The optimization considers both transmission security and power system stability constraints. The results of the optimization provide regulators with a support instrument to give proper signals to WT investors, in order to achieve secure and cost effective wind power network integration. The proposal is especially aimed at countries in the initial stage of wind power development, where the WT network integration process can still be influenced by policy-makers. The proposed methodology is validated with a real power system. Obtained results are compared with those generated from a business-as-usual (BAU scenario, in which the WT network allocation is made according to existing WT projects. The proposed WT network allocation scheme not only reduces the total investment costs associated with a determined wind power energy target, but also improves power system stability.
Optimal irrigation water allocation for a center pivot using remotely sensed data
Hassan Esfahani, L.; McKee, M.
2013-12-01
Efficient irrigation can help avoid crop water stress, undesirable leaching of nutrients, and yield reduction due to water shortage, and runoff and soil erosion due to over irrigation. Gains in water use efficiency can be achieved when water application is precisely matched to the spatially distributed crop water demand. This is important to produce high quality crops and otherwise conserve water for greatest efficiency of use. Irrigation efficiency is a term which defines irrigation performance based on indicators such as irrigation uniformity, crop production, economic return and water resources sustainability. The present paper introduces a modeling approach for optimal water allocation to a center pivot irrigation unit in consideration of these types of indicators. Landsat images, weather data and field measurements were used to develop a soil water balance model using Artificial Neural Networks (ANN). The model includes two main modules, one for soil water forecasting and one for optimization of water allocation. The optimization module uses Genetic Algorithms (GA) to identify optimal crop water application rates based on the crop type, growing stage and sensitivity to water stress. The forecasting module allocates water through time across the area covered by the center pivot considering the results from the previous period of irrigation and the operational limitations of the center pivot irrigation system. The model was tested for a farm equipped with a modern sprinkler irrigation system in Scipio, Utah. The solution obtained from the model used up to 30 percent less water without reducing the benefits realized by the irrigator than traditional operating procedures.
Institute of Scientific and Technical Information of China (English)
Wei WANG; Hua-yong YANG; Jun ZOU; Xiao-dong RUAN; Xin FU
2009-01-01
We proposed an optimal design method to expand the bandwidth for the control of large hydraulic Stewart platform. The method is based on generalized natural frequency and takes hydraulic oil into consideration. A Lagrangian formulation which considers the whole leg inertia is presented to obtain the accurate equivalent mass matrix. Using the model, the effect of leg inertia and the influence of design parameters on the generalized natural frequency are investigated. Finally, numerical examples are presented to validate and confirm the efficiency of the mathematical model. The results show that the leg inertia, especially the piston part plays an important role in the dynamics. The optimum diameter ratio of the base to the moving platform is between 2 and 3, and the optimum joint angle ratio of the base to the moving platform is about 1. The smaller joint angles and a longer leg stroke are favorable for raising system frequencies. The system oil should be preprocessed for large platforms with a requirement for good dynamic performance.
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
An optimal power allocation (OPA) method with mean channel gains is proposed for a multinode amplify-and-forward cooperative communication system. By making use of M-PSK modulation, a closed-form symbol-error-rate (SER) formulation and corresponding upper bound are first derived. Subsequently the OPA method is utilized to minimize the SER. Comparison of the SER of the proposed OPA method with that of the equal power allocation (EPA) method, shows that the SER of both methods, which is approximately optimal performance, is almost the same when relays are near the source. OPA outperforms the EPA when the relays are near the middle between the source and destination or near the destination. The proposed OPA method depends only on the ratio of mean channel gains of the source-to-relay to those of the relay-to-destination. Extensive simulations are performed to validate the theoretical results.
A Grooming Nodes Optimal Allocation Method for Multicast in WDM Networks
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Chengying Wei
2016-01-01
Full Text Available The grooming node has the capability of grooming multicast traffic with the small granularity into established light at high cost of complexity and node architecture. In the paper, a grooming nodes optimal allocation (GNOA method is proposed to optimize the allocation of the grooming nodes constraint by the blocking probability for multicast traffic in sparse WDM networks. In the proposed GNOA method, the location of each grooming node is determined by the SCLD strategy. The improved smallest cost largest degree (SCLD strategy is designed to select the nongrooming nodes in the proposed GNOA method. The simulation results show that the proposed GNOA method can reduce the required number of grooming nodes and decrease the cost of constructing a network to guarantee a certain request blocking probability when the wavelengths per fiber and transmitter/receiver ports per node are sufficient for the optical multicast in WDM networks.
Jaramillo, Juan Jose
2009-01-01
This paper studies the problem of congestion control and scheduling in ad hoc wireless networks that have to support a mixture of best-effort and real-time traffic. Optimization and stochastic network theory have been successful in designing architectures for fair resource allocation to meet long-term throughput demands. However, to the best of our knowledge, strict packet delay deadlines were not considered in this framework previously. In this paper, we propose for the first time a model for incorporating the quality of service (QoS) requirements of packets with deadlines in the optimization framework. The solution to the problem results in a joint congestion control and scheduling algorithm which fairly allocates resources to meet the fairness objectives of both elastic and inelastic flows, and per-packet delay requirements of inelastic flows.
Optimal allocation of solar based distributed generators in distribution system using Bat algorithm
Directory of Open Access Journals (Sweden)
Suresh Kumar Sudabattula
2016-09-01
Full Text Available With increased demand of electrical energy, limited availability of fossil fuels and environmental concerns, it is necessary to consider renewable energy based generation in a power system network. Optimal allocation of renewable based distributed generators in the distribution system is a challenging task in the recent years. In this paper an effective technique is proposed for optimal allocation of solar based distributed generators in the distribution network using a Bat algorithm (BA is presented. The objective is to minimize power loss of radial distribution system. Different operating constraints related to the distribution network are considered. The stochastic nature of solar irradiance is modeled by using suitable probability distribution function (PDF. The proposed method is tested and validated on IEEE 33 bus test system.
Zhou, Yanlai; Guo, Shenglian; Xu, Chong-Yu; Liu, Dedi; Chen, Lu; Wang, Dong
2015-12-01
Climate change, rapid economic development and increase of the human population are considered as the major triggers of increasing challenges for water resources management. This proposed integrated optimal allocation model (IOAM) for complex adaptive system of water resources management is applied in Dongjiang River basin located in the Guangdong Province of China. The IOAM is calibrated and validated under baseline period 2010 year and future period 2011-2030 year, respectively. The simulation results indicate that the proposed model can make a trade-off between demand and supply for sustainable development of society, economy, ecology and environment and achieve adaptive management of water resources allocation. The optimal scheme derived by multi-objective evaluation is recommended for decision-makers in order to maximize the comprehensive benefits of water resources management.
DEFF Research Database (Denmark)
Larsen, Christian
2005-01-01
for the service but there is no waiting time, hence no waiting costs. Under the premises that the subcontractor prices his services in order to maximize his profit, we study two work allocation rules, which given the price of subcontractor seek to allocate work such that the costs of the customers are minimized......We study a service system modelled as a single server queuing system where request for service either can be processed at the service system or by a subcontractor. In the former case the customer is incurred waiting costs but the service is free, while in the latter case the customer must pay...... also show that from the customers point view, any of the two work allocation rules are to be preferred compared to the base case where there are no subcontractor. Udgivelsesdato: MAR...
Optimal power allocation of a sensor node under different rate constraints
Ayala Solares, Jose Roberto
2012-06-01
The optimal transmit power of a sensor node while satisfying different rate constraints is derived. First, an optimization problem with an instantaneous transmission rate constraint is addressed. Next, the optimal power is analyzed, but now with an average transmission rate constraint. The optimal solution for a class of fading channels, in terms of system parameters, is presented and a suboptimal solution is also proposed for an easier, yet efficient, implementation. Insightful asymptotical analysis for both schemes, considering a Rayleigh fading channel, are shown. Finally, the optimal power allocation for a sensor node in a cognitive radio environment is analyzed where an optimum solution for a class of fading channels is again derived. In all cases, numerical results are provided for either Rayleigh or Nakagami-m fading channels. © 2012 IEEE.
Reliability Allocation of Underwater Experiment System Based on Particle Swarm Optimization
Directory of Open Access Journals (Sweden)
Lu Xiong
2013-06-01
Full Text Available The problem of system reliability allocation is often solved by direct search method. The shortage, which affects the application of this method, is the large calculation amount of complex system architecture. Particle Swarm Optimization (PSO is a popular and bionic algorithm based on the social behavior associated with bird flocking for optimization problems. The particle swarm optimization, which attracted the interest of researchers. In this paper, a kind of PSO algorithm is proposed to solve underwater experimental system reliability problems. In addition, the reliability of the system model is established as well, the model is numerically simulated by PSO algorithm and examples are provided. The results show that compared to other algorithms, PSO has a better adaptability and can solve the optimal solution more stably without the precocious weakness, which is more suitable for reliability optimization of a system underwater with a more complex structure.
Cook, Darcy; Ferens, Ken; Kinsner, Witold
Simulated Annealing (SA) has shown to be a successful technique in optimization problems. It has been applied to both continuous function optimization problems, and combinatorial optimization problems. There has been some work in modifying the SA algorithm to apply properties of chaotic processes with the goal of reducing the time to converge to an optimal or a good solution. There are several variations of these chaotic simulated annealing (CSA) algorithms. In this paper a new variation of chaotic simulated annealing is proposed and is applied in solving a combinatorial optimization problem in multiprocessor task allocation. The experiments show the CSA algorithms reach a good solution faster than traditional SA algorithms in many cases because of a wider initial solution search.
Haruvy, Nava; Shalhevet, Sarit
2006-01-01
Regional planning should consider the impact of agricultural crops on housing value and leisure, as well as on the local environment. We designed an optimization model for allocating agricultural crops based on farmers profits as well as the impact on these three factors. Each crop creates a different landscape, as well as a different effect on shading and noise reduction. These in turn influence the value of nearby housing and the regional leisure opportunities. Each crop also has a positive...
Optimal Capacity Allocation of Large-Scale Wind-PV-Battery Units
Kehe Wu; Huan Zhou; Jizhen Liu
2014-01-01
An optimal capacity allocation of large-scale wind-photovoltaic- (PV-) battery units was proposed. First, an output power model was established according to meteorological conditions. Then, a wind-PV-battery unit was connected to the power grid as a power-generation unit with a rated capacity under a fixed coordinated operation strategy. Second, the utilization rate of renewable energy sources and maximum wind-PV complementation was considered and the objective function of full life cycle-net...
A Model of Optimal Allocations of Physical Capital and Human Capital in Three Sectors
Institute of Scientific and Technical Information of China (English)
ZHOU Shaobo; XUE Minggao
2007-01-01
The paper develops an endogenous economic growth model about allcation of physical and human capital in three sectors. Optimal allocation of physical capital and human capital in three sectors is derived, the fraction of physical and human capital in each sector is positively related. The balanced values and the growth rates at steady state are given under certain conditions.Finally relations between the fractions of human capital and parameters are analyzed elaborately.
Optimal Storage Allocation for Wireless Cloud Caching Systems with a Limited Sum Storage Capacity
Hong, Bi; Choi, Wan
2016-01-01
In wireless cloud storage systems, the recovery failure probability depends on not only wireless channel conditions but also storage size of each distributed storage node. For an efficient utilization of limited storage capacity and the performance characterization of allocation strategies, we asymptotically analyze the recovery failure probability of a wireless cloud storage system with a sum storage capacity constraint for both high SNR regime and low SNR regime. Then, we find the optimal s...
Zhiteng Wang; Hongjun Zhang; Rui Zhang; Yong Li; Xuliang Zhang
2014-01-01
Service oriented modeling and simulation are hot issues in the field of modeling and simulation, and there is need to call service resources when simulation task workflow is running. How to optimize the service resource allocation to ensure that the task is complete effectively is an important issue in this area. In military modeling and simulation field, it is important to improve the probability of success and timeliness in simulation task workflow. Therefore, this paper proposes an optimiz...
A Hybrid Inexact Optimization Model for Land-use Allocation of China
Institute of Scientific and Technical Information of China (English)
ZHOU Min; CAI Yunlong; GUAN Xingliang; TAN Shukui; LU Shasha
2015-01-01
Land scarcity has become the prominent obstacle on the way to sustainable development for China.Under the constraints of land shortage,how to allocate the finite land resources to the multiple land users in China considering various political,environmental,ecological and economic conditions have become research topics with great significance.In this study,an interval fuzzy national-scale land-use model (IFNLM) was developed for optimizing land systems of China.IFNLM is based on an integration of existing interval linear programming (ILP),and fuzzy flexible programming (FFP) techniques.IFNLM allows uncertainties expressed as discrete interval values and fuzzy sets to be incorporated within a general optimization framework.It can also facilitate national-scale land-use planning under various environmental,ecological,social conditions within a multi-period and multi-option context.Then,IFNLM was applied to a real case study of land-use planning in China.The satisfaction degree of environmental constraints is between 0.69 and 0.97,the system benefit will between 198.25 × 1012 USD and 229.67 × 1012 USD.The results indicated that the hybrid model can help generate desired policies for land-use allocation with a maximized economic benefit and minimized environmental violation risk.Optimized land-use allocation pattems can be generated from the proposed IFNLM.
Cellular trade-offs and optimal resource allocation during cyanobacterial diurnal growth.
Reimers, Alexandra-M; Knoop, Henning; Bockmayr, Alexander; Steuer, Ralf
2017-07-18
Cyanobacteria are an integral part of Earth's biogeochemical cycles and a promising resource for the synthesis of renewable bioproducts from atmospheric CO2 Growth and metabolism of cyanobacteria are inherently tied to the diurnal rhythm of light availability. As yet, however, insight into the stoichiometric and energetic constraints of cyanobacterial diurnal growth is limited. Here, we develop a computational framework to investigate the optimal allocation of cellular resources during diurnal phototrophic growth using a genome-scale metabolic reconstruction of the cyanobacterium Synechococcus elongatus PCC 7942. We formulate phototrophic growth as an autocatalytic process and solve the resulting time-dependent resource allocation problem using constraint-based analysis. Based on a narrow and well-defined set of parameters, our approach results in an ab initio prediction of growth properties over a full diurnal cycle. The computational model allows us to study the optimality of metabolite partitioning during diurnal growth. The cyclic pattern of glycogen accumulation, an emergent property of the model, has timing characteristics that are in qualitative agreement with experimental findings. The approach presented here provides insight into the time-dependent resource allocation problem of phototrophic diurnal growth and may serve as a general framework to assess the optimality of metabolic strategies that evolved in phototrophic organisms under diurnal conditions.
Allocating HIV prevention funds in the United States: recommendations from an optimization model.
Directory of Open Access Journals (Sweden)
Arielle Lasry
Full Text Available The Centers for Disease Control and Prevention (CDC had an annual budget of approximately $327 million to fund health departments and community-based organizations for core HIV testing and prevention programs domestically between 2001 and 2006. Annual HIV incidence has been relatively stable since the year 2000 and was estimated at 48,600 cases in 2006 and 48,100 in 2009. Using estimates on HIV incidence, prevalence, prevention program costs and benefits, and current spending, we created an HIV resource allocation model that can generate a mathematically optimal allocation of the Division of HIV/AIDS Prevention's extramural budget for HIV testing, and counseling and education programs. The model's data inputs and methods were reviewed by subject matter experts internal and external to the CDC via an extensive validation process. The model projects the HIV epidemic for the United States under different allocation strategies under a fixed budget. Our objective is to support national HIV prevention planning efforts and inform the decision-making process for HIV resource allocation. Model results can be summarized into three main recommendations. First, more funds should be allocated to testing and these should further target men who have sex with men and injecting drug users. Second, counseling and education interventions ought to provide a greater focus on HIV positive persons who are aware of their status. And lastly, interventions should target those at high risk for transmitting or acquiring HIV, rather than lower-risk members of the general population. The main conclusions of the HIV resource allocation model have played a role in the introduction of new programs and provide valuable guidance to target resources and improve the impact of HIV prevention efforts in the United States.
Converse, Sarah J.; Shelley, Kevin J.; Morey, Steve; Chan, Jeffrey; LaTier, Andrea; Scafidi, Carolyn; Crouse, Deborah T.; Runge, Michael C.
2011-01-01
The resources available to support conservation work, whether time or money, are limited. Decision makers need methods to help them identify the optimal allocation of limited resources to meet conservation goals, and decision analysis is uniquely suited to assist with the development of such methods. In recent years, a number of case studies have been described that examine optimal conservation decisions under fiscal constraints; here we develop methods to look at other types of constraints, including limited staff and regulatory deadlines. In the US, Section Seven consultation, an important component of protection under the federal Endangered Species Act, requires that federal agencies overseeing projects consult with federal biologists to avoid jeopardizing species. A benefit of consultation is negotiation of project modifications that lessen impacts on species, so staff time allocated to consultation supports conservation. However, some offices have experienced declining staff, potentially reducing the efficacy of consultation. This is true of the US Fish and Wildlife Service's Washington Fish and Wildlife Office (WFWO) and its consultation work on federally-threatened bull trout (Salvelinus confluentus). To improve effectiveness, WFWO managers needed a tool to help allocate this work to maximize conservation benefits. We used a decision-analytic approach to score projects based on the value of staff time investment, and then identified an optimal decision rule for how scored projects would be allocated across bins, where projects in different bins received different time investments. We found that, given current staff, the optimal decision rule placed 80% of informal consultations (those where expected effects are beneficial, insignificant, or discountable) in a short bin where they would be completed without negotiating changes. The remaining 20% would be placed in a long bin, warranting an investment of seven days, including time for negotiation. For formal
Optimal reconfiguration and DG allocation in balanced and unbalanced distribution systems
Directory of Open Access Journals (Sweden)
Seyed Abbas Taher
2014-09-01
Full Text Available This paper investigates feeder reconfiguration in balanced and unbalanced networks and presents an efficient method to optimize practical distribution systems by means of simultaneous reconfiguration and distributed generation (DG allocation. A precise and robust load flow algorithm is applied and a composite multi-objective function is formulated to solve the problem which includes: 1. power loss saving, 2. voltage profile, 3. voltage unbalance, and 4. current unbalance of the system. The genetic algorithm (GA is utilized to search for optimal solution. Results show significant reduction in power loss and number of voltage violations. Moreover, in unbalanced cases, ability of proposed method in three-phase balancing is demonstrated.
Institute of Scientific and Technical Information of China (English)
刘鑫; 仲伟志; 陈琨奇
2015-01-01
In order to improve the throughput of cognitive radio (CR), optimization of sensing time and cooperative user allocation for OR-rule cooperative spectrum sensing was investigated in a CR network that includes multiple users and one fusion center. The frame structure of cooperative spectrum sensing was divided into multiple transmission time slots and one sensing time slot consisting of local energy detection and cooperative overhead. An optimization problem was formulated to maximize the throughput of CR network, subject to the constraints of both false alarm probability and detection probability. A joint optimization algorithm of sensing time and number of users was proposed to solve this optimization problem with low time complexity. An allocation algorithm of cooperative users was proposed to preferentially allocate the users to the channels with high utilization probability. The simulation results show that the significant improvement on the throughput can be achieved through the proposed joint optimization and allocation algorithms.
Multiobjective Optimization of Allocated Exchange Portfolio: Model and Solution—A Case Study in Iran
Directory of Open Access Journals (Sweden)
Mostafa Ekhtiari
2014-01-01
Full Text Available This paper presents a triobjective model for optimization of allocated exchange portfolio. The objectives of this model are minimizing risk and investment initial cost (by adopting two synchronic policies of buying and selling assets and maximizing return, to optimize allocated portfolios (APs. In an AP, an investor by considering previous investment experiences and market conditions selects the within portfolio assets. Then, considering proposed model, the assets proportion of AP is optimized for a limited time horizon. In optimizing a multiobjective problem of an AP, risk and return objectives are measured on the basis of standard deviation of assets dairy return and dairy return mean within AP assets, respectively. We present a set of interobjectives trade-offs along with an analysis of Iran Melli bank investment in an exchange AP, using Weighted Global Criterion (WGC method with assumption p=1, 2, and ∞ to optimize the proposed model. Results of WGC model (in all p=1, 2 and ∞ represent that US dollar exchange in comparison with other exchanges, was rather the fewest exchange proportion in Iran Melli bank exchange AP which this is consistent with Iran exchange investment policy of more concentration on other exchanges.
Optimizing rice plant photosynthate allocation reduces N2O emissions from paddy fields
Jiang, Yu; Huang, Xiaomin; Zhang, Xin; Zhang, Xingyue; Zhang, Yi; Zheng, Chengyan; Deng, Aixing; Zhang, Jun; Wu, Lianhai; Hu, Shuijin; Zhang, Weijian
2016-07-01
Rice paddies are a major source of anthropogenic nitrous oxide (N2O) emissions, especially under alternate wetting-drying irrigation and high N input. Increasing photosynthate allocation to the grain in rice (Oryza sativa L.) has been identified as an effective strategy of genetic and agronomic innovation for yield enhancement; however, its impacts on N2O emissions are still unknown. We conducted three independent but complementary experiments (variety, mutant study, and spikelet clipping) to examine the impacts of rice plant photosynthate allocation on paddy N2O emissions. The three experiments showed that N2O fluxes were significantly and negatively correlated with the ratio of grain yield to total aboveground biomass, known as the harvest index (HI) in agronomy (P < 0.01). Biomass accumulation and N uptake after anthesis were significantly and positively correlated with HI (P < 0.05). Reducing photosynthate allocation to the grain by spikelet clipping significantly increased white root biomass and soil dissolved organic C and reduced plant N uptake, resulting in high soil denitrification potential (P < 0.05). Our findings demonstrate that optimizing photosynthate allocation to the grain can reduce paddy N2O emissions through decreasing belowground C input and increasing plant N uptake, suggesting the potential for genetic and agronomic efforts to produce more rice with less N2O emissions.
Directory of Open Access Journals (Sweden)
Li Ran
2017-01-01
Full Text Available Optimal allocation of generalized power sources in distribution network is researched. A simple index of voltage stability is put forward. Considering the investment and operation benefit, the stability of voltage and the pollution emissions of generalized power sources in distribution network, a multi-objective optimization planning model is established. A multi-objective particle swarm optimization algorithm is proposed to solve the optimal model. In order to improve the global search ability, the strategies of fast non-dominated sorting, elitism and crowding distance are adopted in this algorithm. Finally, tested the model and algorithm by IEEE-33 node system to find the best configuration of GP, the computed result shows that with the generalized power reasonable access to the active distribution network, the investment benefit and the voltage stability of the system is improved, and the proposed algorithm has better global search capability.
Optimal processor allocation for sort-last compositing under BSP-tree ordering
Ramakrishnan, C. R.; Silva, Claudio T.
1999-03-01
In this paper, we consider a parallel rendering model that exploits the fundamental distinction between rendering and compositing operations, by assigning processors from specialized pools for each of these operations. Our motivation is to support the parallelization of general scan-line rendering algorithms with minimal effort, basically by supporting a compositing back-end (i.e., a sort-last architecture) that is able to perform user-controlled image composition. Our computational model is based on organizing rendering as well as compositing processors on a BSP-tree, whose internal nodes we call the compositing tree. Many known rendering algorithms, such as volumetric ray casting and polygon rendering can be easily parallelized based on the structure of the BSP-tree. In such a framework, it is paramount to minimize the processing power devoted to compositing, by minimizing the number of processors allocated for composition as well as optimizing the individual compositing operations. In this paper, we address the problems related to the static allocation of processor resources to the compositing tree. In particular, we present an optimal algorithm to allocate compositing operations to compositing processors. We also present techniques to evaluate the compositing operations within each processor using minimum memory while promoting concurrency between computation and communication. We describe the implementation details and provide experimental evidence of the validity of our techniques in practice.
Shi, Shengchao; Li, Guangxia; An, Kang; Gao, Bin; Zheng, Gan
2017-09-04
This paper proposes novel satellite-based wireless sensor networks (WSNs), which integrate the WSN with the cognitive satellite terrestrial network. Having the ability to provide seamless network access and alleviate the spectrum scarcity, cognitive satellite terrestrial networks are considered as a promising candidate for future wireless networks with emerging requirements of ubiquitous broadband applications and increasing demand for spectral resources. With the emerging environmental and energy cost concerns in communication systems, explicit concerns on energy efficient resource allocation in satellite networks have also recently received considerable attention. In this regard, this paper proposes energy-efficient optimal power allocation schemes in the cognitive satellite terrestrial networks for non-real-time and real-time applications, respectively, which maximize the energy efficiency (EE) of the cognitive satellite user while guaranteeing the interference at the primary terrestrial user below an acceptable level. Specifically, average interference power (AIP) constraint is employed to protect the communication quality of the primary terrestrial user while average transmit power (ATP) or peak transmit power (PTP) constraint is adopted to regulate the transmit power of the satellite user. Since the energy-efficient power allocation optimization problem belongs to the nonlinear concave fractional programming problem, we solve it by combining Dinkelbach's method with Lagrange duality method. Simulation results demonstrate that the fading severity of the terrestrial interference link is favorable to the satellite user who can achieve EE gain under the ATP constraint comparing to the PTP constraint.
Nearly Optimal Resource Allocation for Downlink OFDMA in 2-D Cellular Networks
Ksairi, Nassar; Ciblat, Philippe
2010-01-01
In this paper, we propose a resource allocation algorithm for the downlink of sectorized two-dimensional (2-D) OFDMA cellular networks assuming statistical Channel State Information (CSI) and fractional frequency reuse. The proposed algorithm can be implemented in a distributed fashion without the need to any central controlling units. Its performance is analyzed assuming fast fading Rayleigh channels and Gaussian distributed multicell interference. We show that the transmit power of this simple algorithm tends, as the number of users grows to infinity, to the same limit as the minimal power required to satisfy all users' rate requirements i.e., the proposed resource allocation algorithm is asymptotically optimal. As a byproduct of this asymptotic analysis, we characterize a relevant value of the reuse factor that only depends on an average state of the network.
Abdelhady, Amr, M.
2016-01-06
Multi-teir hetrogeneous networks have become an essential constituent for next generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-teir architecture known as Phantom cellular networks. The optimization framework includes both EE and SE, where we propose an algorithm that computes the SE and EE resource allocation for Phantom cellular networks. Then, we compare the performance of both design strategies versus the number of users, and the ration of Phantom cellresource blocks to the total number or resource blocks. We aim to investigate the effect of some system parameters to acheive improved SE or EE performance at a non-significant loss in EE or SE performance, respectively. It was found that the system parameters can be tuned so that the EE solution does not yield a significant loss in the SE performance.
Zhu, Wenlong; Ma, Shoufeng; Tian, Junfang
2017-01-01
This paper investigates the revenue-neutral tradable credit charge and reward scheme without initial credit allocations that can reassign network traffic flow patterns to optimize congestion and emissions. First, we prove the existence of the proposed schemes and further decentralize the minimum emission flow pattern to user equilibrium. Moreover, we design the solving method of the proposed credit scheme for minimum emission problem. Second, we investigate the revenue-neutral tradable credit charge and reward scheme without initial credit allocations for bi-objectives to obtain the Pareto system optimum flow patterns of congestion and emissions; and present the corresponding solutions are located in the polyhedron constituted by some inequalities and equalities system. Last, numerical example based on a simple traffic network is adopted to obtain the proposed credit schemes and verify they are revenue-neutral.
Zhu, Hongjian
2016-12-12
Seamless phase II/III clinical trials have attracted increasing attention recently. They mainly use Bayesian response adaptive randomization (RAR) designs. There has been little research into seamless clinical trials using frequentist RAR designs because of the difficulty in performing valid statistical inference following this procedure. The well-designed frequentist RAR designs can target theoretically optimal allocation proportions, and they have explicit asymptotic results. In this paper, we study the asymptotic properties of frequentist RAR designs with adjusted target allocation proportions, and investigate statistical inference for this procedure. The properties of the proposed design provide an important theoretical foundation for advanced seamless clinical trials. Our numerical studies demonstrate that the design is ethical and efficient.
Stowage Plan Based Slot Optimal Allocation in Rail-Water Container Terminal
Directory of Open Access Journals (Sweden)
Yanjing Li
2017-01-01
Full Text Available To obtain an efficient and reasonable solution for slot allocation in rail-water container terminals, this paper develops storage optimal allocation model 1 to improve the yard space utilization, which is solved by a heuristic algorithm based on Tabu search. Model 2 is then built to reduce the relocation movements. A concept of fall-down problem in shunting operation plan is thus proposed to solve model 2. Models 1 and 2 are tested with numerical experiments. The results show that the yard space utilization increases by 50% approximately compared to the strategy of one train piling onto a fixed area called a subblock. Meanwhile the number of container relocation movements is less than five when using the fall-down problem strategy. Accordingly, the models and algorithms developed in this paper are effective to improve the yard space utilization and reduce the number of container relocation movements.
Alsharoa, Ahmad M.
2014-06-01
In this paper, the problem of power allocation for a multiple-input multiple-output two-way system is investigated in underlay Cognitive Radio (CR) set-up. In the CR underlay mode, secondary users are allowed to exploit the spectrum allocated to primary users in an opportunistic manner by respecting a tolerated temperature limit. The secondary networks employ an amplify-and-forward two-way relaying technique in order to maximize the sum rate under power budget and interference constraints. In this context, we formulate an optimization problem that is solved in two steps. First, we derive a closed-form expression of the optimal power allocated to terminals. Then, we employ a strong optimization tool based on particle swarm optimization algorithm to find the power allocated to secondary relays. Simulation results demonstrate the efficiency of the proposed solution and analyze the impact of some system parameters on the achieved performance. © 2014 IEEE.
Zhang, Chao; Ren, Pinyi; Peng, Jingbo; Wei, Guo; Du, Qinghe; Wang, Yichen
2011-01-01
In this paper, we propose an optimal relay power allocation of an Amplify-and-Forward relay networks with non-linear power amplifiers. Based on Bussgang Linearization Theory, we depict the non-linear amplifying process into a linear system, which lets analyzing system performance easier. To obtain spatial diversity, we design a complete practical framework of a non-linear distortion aware receiver. Consider a total relay power constraint, we propose an optimal power allocation scheme to maxim...
Hillier, FS; So, KC; Boling, RW
1993-01-01
This investigation considers certain issues regarding the optimal design of unpaced production lines with variable processing times. Under certain assumptions, including an equal allocation of buffer storage space between the respective pairs of stations, it is known that the optimal allocation of work is characterized by the "bowl phenomenon" whereby the interior stations (especially the center ones) are given preferential treatment (less work) over the end stations. The key question now bei...
Scheduling for Optimal Rate Allocation in Ad Hoc Networks With Heterogeneous Delay Constraints
Jaramillo, Juan Jose; Ying, Lei
2010-01-01
This paper studies the problem of scheduling in single-hop wireless networks with real-time traffic, where every packet arrival has an associated deadline and a minimum fraction of packets must be transmitted before the end of the deadline. Using optimization and stochastic network theory we propose a framework to model the quality of service (QoS) requirements under delay constraints. The model allows for fairly general arrival models with heterogeneous constraints. The framework results in an optimal scheduling algorithm which fairly allocates data rates to all flows while meeting long-term delay demands. We also prove that under a simplified scenario our solution translates into a greedy strategy that makes optimal decisions with low complexity.
An Optimal Allocation Model of Public Transit Mode Proportion for the Low-Carbon Transportation
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Linjun Lu
2015-01-01
Full Text Available Public transit has been widely recognized as a potential way to develop low-carbon transportation. In this paper, an optimal allocation model of public transit mode proportion (MPMP has been built to achieve the low-carbon public transit. Optimal ratios of passenger traffic for rail, bus, and taxi are derived by running the model using typical data. With different values of traffic demand, construction cost, travel time, and accessibilities, MPMP can generate corresponding optimal ratios, benefiting decision impacts analysis and decision makers. Instead of considering public transit as a united system, it is separated into units in this paper. And Shanghai is used to test model validity and practicality.
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Mehdi Mohammad khani
2017-06-01
Full Text Available Introduction: Evaluations show the necessity of using optimization models in order to determine optimal allocation of water in different water conditions. Its use can be proposed according to developed model abilities in this study in order to optimize water productivity and provide sustainable management and development of water resources over irrigation and drainage networks. Basic needs of the earth growing population and limitation of water and soil resources remindnecessity of optimal use of resources. World’s more than 280 million hectare lands are covered by irrigation networks (Khalkhali et al., 2006. The efficiency of most projects is between 30-50 percent and studies show that performance of most irrigation and drainage networks is not desirable and they have not achieved their aims. Hirich et al. (2014 Used deficit irrigation to improve crop water productivity of sweet corn, chickpea, faba bean and quinoa. For all crops, the highest water productivity and yield were obtained when deficit irrigation was applied during the vegetative growth stage. During the second season 2011 two cultivars of quinoa, faba bean and sweet corn have been cultivated applying 6 deficit irrigation treatments (rainfed, 0, 25, 50, 75 and 100% of full irrigation only during the vegetative growth stage, while in the rest of a crop cycle full irrigation was provided except for rainfed treatment. For quinoa and faba bean, treatment receiving 50% of the full irrigation during the vegetative growth stage recorded the highest yield and water productivity, while for sweet corn applying 75% of full irrigation was the optimal treatment in terms of yield and water productivity. Moghaddasi et al. (2010 worked examines and compares this approach with that based on the optimization method to manage agricultural water demand during drought to minimize damage. The results show that the optimization method resulted in 42% more income for the agricultural sector using the
DEFF Research Database (Denmark)
Larsen, Christian
2003-01-01
We study a service system modelled as a single server queueing system where request for service either can be processed at the service system or by a subcontractor. In the former case the customer is incurred waiting costs but the service is free, while in the latter case the customer must pay...... are minimized. The two work allocation rules are characterized by one being centralized and randomized while the other is decentralized and deterministic. Form the subcontractors point of view the latter is preferred and under this rule he receives lesser requests but can charge a higher price compared...
DEFF Research Database (Denmark)
Larsen, Christian
We study a service system modelled as a single server queueing system where requests for service either can be processed at the service system or by a subcontractor. In the former case the subcontractor is incurred waiting costs but the service is free, while in the latter case the customer must...... of the customers are minimized. The two work allocation rules are characterized by one being centralized and randomized while the other is decentralized and deterministic. From the subcontractors point of view the latter is preferred and under this rule he receives lesser requests but can charge a higher price...
DEFF Research Database (Denmark)
Larsen, Christian
2005-01-01
We study a service system modelled as a single server queuing system where request for service either can be processed at the service system or by a subcontractor. In the former case the customer is incurred waiting costs but the service is free, while in the latter case the customer must pay....... The two work allocation rules are characterized by one being centralized and randomized while the other is decentralized and deterministic. From the subcontractors point of view the latter is preferred and under this rule he receives lesser requests but can charge a higher price compared to the former. We...
Directory of Open Access Journals (Sweden)
Álvaro Gutiérrez
2011-11-01
Full Text Available Swarms of robots can use their sensing abilities to explore unknown environments and deploy on sites of interest. In this task, a large number of robots is more effective than a single unit because of their ability to quickly cover the area. However, the coordination of large teams of robots is not an easy problem, especially when the resources for the deployment are limited. In this paper, the Distributed Bees Algorithm (DBA, previously proposed by the authors, is optimized and applied to distributed target allocation in swarms of robots. Improved target allocation in terms of deployment cost efficiency is achieved through optimization of the DBA’s control parameters by means of a Genetic Algorithm. Experimental results show that with the optimized set of parameters, the deployment cost measured as the average distance traveled by the robots is reduced. The cost-efficient deployment is in some cases achieved at the expense of increased robots’ distribution error. Nevertheless, the proposed approach allows the swarm to adapt to the operating conditions when available resources are scarce.
Power and time slot allocation in cognitive relay networks using particle swarm optimization.
Derakhshan-Barjoei, Pouya; Dadashzadeh, Gholamreza; Razzazi, Farbod; Razavizadeh, S Mohammad
2013-01-01
The two main problems in cognitive radio networks are power and time slot allocation problems which require a precise analysis and guarantee the quality of service in both the primary and secondary users. In this paper, these two problems are considered and a method is proposed to solve the resulting optimization problem. Our proposed method provides an improved performance in solving the constrained nonlinear multiobject optimization for the power control and beamforming in order to reach the maximum capacity and proper adaption of time slots, and as a result a new scheme for joint power and time slot allocation in cognitive relay networks is proposed. We adopt space diversity access as the secondary users access scheme and divide the time between multiple secondary users according to their contribution to primary user's transmission. Helping primary users provides more opportunities for secondary users to access the channel since the primary users can release the channel sooner. In contrast, primary network leases portion of channel access time to the secondary users for their transmission using particle swarm optimization (PSO). Numerical studies show good performance of the proposed scheme with a dynamic cost function in a nonstationary environment.
Directory of Open Access Journals (Sweden)
Yishu Zhu
2016-10-01
Full Text Available Trauma is considered a “modern civilized sickness”, and its occurrence substantially affects all of society, as well as individuals. The implementation of trauma emergency systems in cities with young, prosperous, and highly mobile populations is necessary and significant. A complete trauma emergency system includes both low-level trauma centers that offer basic emergency services and high-level trauma centers that offer comprehensive services. GIS and operational research methods were used to solve the location problem associated with these centers. This study analyzed the spatial distribution characteristics of trauma demands and the candidate locations of trauma centers based on a spatial analysis and presented a hierarchical location-allocation model for low- and high-level trauma centers in Shenzhen. The response, coverage, treatment and cost capacities of the trauma center locations were considered, and an ant colony optimization was used to calculate the optimal solution. The objectives of this study were to optimize trauma center locations, improve the allocation of medical trauma resources and reduce the rate of deaths and disabilities due to trauma.
Jevtić, Aleksandar; Gutiérrez, Alvaro
2011-01-01
Swarms of robots can use their sensing abilities to explore unknown environments and deploy on sites of interest. In this task, a large number of robots is more effective than a single unit because of their ability to quickly cover the area. However, the coordination of large teams of robots is not an easy problem, especially when the resources for the deployment are limited. In this paper, the distributed bees algorithm (DBA), previously proposed by the authors, is optimized and applied to distributed target allocation in swarms of robots. Improved target allocation in terms of deployment cost efficiency is achieved through optimization of the DBA's control parameters by means of a genetic algorithm. Experimental results show that with the optimized set of parameters, the deployment cost measured as the average distance traveled by the robots is reduced. The cost-efficient deployment is in some cases achieved at the expense of increased robots' distribution error. Nevertheless, the proposed approach allows the swarm to adapt to the operating conditions when available resources are scarce.
Optimal Traffic Allocation for Multi-Stream Aggregation in Heterogeneous Networks
DEFF Research Database (Denmark)
Popovska Avramova, Andrijana; Iversen, Villy Bæk
2015-01-01
This paper investigates an optimal traffic rate allocation method for multi-stream aggregation over heterogeneous networks that deals with effective integration of two or more heterogeneous links for improved data throughput and enhanced quality of experience. The heterogeneity and the dynamic...... nature of radio access networks are considered as important factors for performance improvement by multi-stream aggregation. Therefore, in our model, the networks are represented by different queueing systems in order to indicate networks with opposite quality of service provisioning, capacity and delay...
DEFF Research Database (Denmark)
Sun, Lei; You, Shi; Hu, Junjie;
2016-01-01
One of the major functions of a smart substation (SS) is to restore power supply to interrupted customers as quickly as possible after an outage. The high cost of a smart substation limits its widespread utilization. In this paper, a smart substation allocation model (SSAM) to determine the optimal...... is simplified into a mixed integer linear programming problem which could be solved efficiently with commercial solvers. Finally, the performance of the proposed methodology is demonstrated by the standard RBTS-BUS 4 test system and a medium voltage power distribution system in Denmark....
Optimizing Manpower Allocation for Ground Handling Tasks in Airports using Column Generation
DEFF Research Database (Denmark)
Hansen, Anders Dohn; Kolind, Esben
2008-01-01
teams/workers, possibly with different skills, is required. This study focuses on the scheduling of ground handling tasks in some of Europe's major airports. Any daily schedule must comply with the time windows and skill requirements of tasks, transportation time between locations, the working hours...... algorithm. 12 authentic data sets from two of Europe's major airports are used for testing. Optimal solutions are found for 11 of the test instances. Keywords: Manpower allocation, crew scheduling, vehicle routing with time windows, synchronization, column generation, Branch-and-Price, time window branching...
An optimization model for the costs allocation in spare parts collaborative networks
Ronzoni, Chiara; Ferrara, Andrea; Grassi, Andrea
2017-07-01
The paper focuses on the aftermarket spare parts in the automotive industry. In particular, only products with infrequent and low quantity demand are considered. This work is an extention of a previuos work by the same authors in which a stochastic model for the optimal inventory policy of spare parts has been presented. In this paper the authors improved what has been called "the second layer" in the previous model, that is the products allocation among a collaborative network of distributors. The improvement is related to the basic model and to the introducion of new products in the network.
Multi-Objective Spatial Optimization: Sustainable Land Use Allocation at Sub-Regional Scale
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Guadalupe Azuara García
2017-06-01
Full Text Available The rational use of territorial resources is a key factor in achieving sustainability. Spatial planning is an important tool that helps decision makers to achieve sustainability in the long term. This work proposes a multi-objective model for sustainable land use allocation known as MAUSS (Spanish acronym for “Modelo de Asignación de Uso Sostenible de Suelo” The model was applied to the Plains of San Juan, Puebla, Mexico, which is currently undergoing a rapid industrialization process. The main objective of the model is to generate land use allocations that lead to a territorial balance within regions in three main ways by maximizing income, minimizing negative environmental pressure on water and air through specific evaluations of water use and CO2 emissions, and minimizing food deficit. The non-sorting genetic algorithm II (NSGA-II is the evolutionary optimization algorithm of MAUSS. NSGA-II has been widely modified through a novel and efficient random initializing operator that enables spatial rationale from the initial solutions, a crossover operator designed to streamline the best genetic information transmission as well as diversity, and two geometric operators, geographic dispersion (GDO and the proportion (PO, which strengthen spatial rationality. MAUSS provided a more sustainable land use allocation compared to the current land use distribution in terms of higher income, 9% lower global negative pressure on the environment and 5.2% lower food deficit simultaneously.
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M. N. M. Nasir
2014-05-01
Full Text Available This paper presents three stages of methodology. The first stage is to identify the switching operation for radial network configuration while observe the power losses and the voltage profile without Distributed Generation (DG. The second stage is based on previous paper which is feeder reconfiguration for loss reduction with DGs. The last stage is sizing and allocation DGs at buses with low voltage profile resulted from the first stage to improve the power losses and voltage profile also comparing the result with the second stage. The objective of this method proposed is to show that allocation of DGs simultaneously based on low voltage profile can improve network power losses and improvement of voltage profile. The result shows that improvement on network power losses is 54.92% from Distribution Network Reconfiguration (DNR method. All three stages were tested on standards IEEE 33 bus system by using Particle Swarm Optimization (PSO technique in MATLAB software. This method proved that improvement of power losses and voltage profile by switching and DGs allocation method.
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Zhanqi Wang
2015-02-01
Full Text Available In recent years, water scarcity and irrational utilization have become the pivotal issues for the sustainable development of river basins in China. This paper attempts to propose a new perspective for the optimization of water resources allocation in a typical river basin. In order to conduct an accurate and feasible program for water resources allocation in the water-deficient river basin, a multi-objective and multi-constraint programming model was developed by embedding land use effect as a constraint on water allocation, which was currently solely decided by water resources demand in different water use sectors. The program includes two layers, namely water allocation among different counties located in the middle reaches of the Heihe River Basin and among domestic, industrial, agricultural and ecological uses within one county. Empirical analysis shows that the structural change of land use has an important influence and restriction on the water resources allocation in the river basin. The least cultivated areas that ensure food security and the constraint of construction land quota have great impact on agricultural and industrial water allocation. Moreover, the quantitative change of ecological land greatly affects ecological water allocation. The results demonstrate that the optimal program calculated from land use embedded model can well predicate the actual situation of water allocation in the future. To ensure regional sustainable development, it is vital that reasonable water-saving measures in each water use sector and ecological protection policies be taken.
Institute of Scientific and Technical Information of China (English)
ZHANG Ying; ZHANG Hongqi; NI Dongying; SONG Wei
2012-01-01
In developing countries,land productivity involves little market,where the agricultural land use is mainly determined by the food demands as well as the land suitability.The land use pattern will not ensure everywhere enough land for certain cropping if spatial allocation just according to land use suitability.To solve this problem,a subzone and a pre-allocation for each land use are added in spatial allocation module,and land use suitability and area optimization module are incorporated to constitute a whole agricultural land use optimal allocation (ALUOA) system.The system is developed on the platform.Net 2005 using ArcGIS Engine (version 9.2) and C# language,and is tested and validated in Yili watershed of Xinjiang Region on the newly reclaimed area.In the case study,with the help of soil data obtained from 69 points sampled in the fieldwork in 2008,main river data supplied by the Department of Water Resources of Xinjiang Uygur Autonomous Region in China,and temperature data provided by Data Center for Resources and Environmental Sciences,Chinese Academy of Sciences,land use suitability on eight common crops are evaluated one by one using linear weighted summation method in the land use suitability model.The linear programming (LP) model in area optimization model succeeds to give out land area target of each crop under three scenarios.At last,the land use targets are allotted in space both with a six subzone file and without a subzone file.The results show that the land use maps with a subzone not only ensure every part has enough land for every crop,but also gives a more fragmental land use pattern,with about 87.99％ and 135.92％ more patches than the one without,while at the expense of loss between 15.30％ and 19.53％ in the overall suitability at the same time.
Optimal Precoding Design and Power Allocation for Decentralized Detection of Deterministic Signals
Fang, Jun; Chen, Zhi; Li, Shaoqian
2011-01-01
We consider a decentralized detection problem in a power-constrained wireless sensor networks (WSNs), in which a number of sensor nodes collaborate to detect the presence of a deterministic vector signal. The signal to be detected is assumed known \\emph{a priori}. Given a constraint on the total amount of transmit power, we investigate the optimal linear precoding design for each sensor node. More specifically, in order to achieve the best detection performance, shall sensor nodes transmit their raw data to the fusion center (FC), or transmit compressed versions of their original data? The optimal power allocation among sensors is studied as well. Also, assuming a fixed total transmit power, we examine how the detection performance behaves with the number of sensors in the network. A new concept "detection outage" is proposed to quantify the reliability of the overall detection system. Finally, decentralized detection with unknown signals is studied. Numerical results are conducted to corroborate our theoreti...
Structural patterns of land types and optimal allocation of land use in Qinling Mountains
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward three structural patterns of land types in mountainous areas, namely, spatial, quantitative and qualitative structures of mountainous land types. Furthermore, it has been noticed that the analysis of structural patterns can disclose the heterogeneity and orderliness of combination of land types, which can lay the theoretic foundation for comprehensively recognizing ecological characteristics and succession law of structure and function of land types. After the all-around comparative analysis, an optimal allocation of land use in Qinling Mountains has been put forward according to the principle of sustainable development and landscape ecology, which can lay the scientific foundation in practice for the structural adjustment and distribution optimization from the macro level to micro level.
Ikki, Salama Said
2013-02-01
A study of the effects of co-channel interference on a multirelay system with decode-and-forward (DF) protocol is presented. Orthogonal relaying is considered, and all relays that correctly decode the message in the broadcasting phase participate in the adaptive relaying phase. First, the effective signal-to-interference-plus-noise ratio (SINR) at the receiver is derived. Then, considering outage as the performance metric, we obtain exact closed-form expression for the outage probability. Simple and general asymptotic expressions for the outage probability, which explicitly show the coding and the diversity gains, are also derived and discussed. Furthermore, we present optimal energy-allocation schemes for minimizing outage under different resource constraints. Monte Carlo simulations are further provided to confirm the analytical results and illustrate the outage performance for different interference conditions and optimization schemes. © 1967-2012 IEEE.
Dynamic Allocation of SPM Based on Time-Slotted Cache Conflict Graph for System Optimization
Wu, Jianping; Ling, Ming; Zhang, Yang; Mei, Chen; Wang, Huan
This paper proposes a novel dynamic Scratch-pad Memory allocation strategy to optimize the energy consumption of the memory sub-system. Firstly, the whole program execution process is sliced into several time slots according to the temporal dimension; thereafter, a Time-Slotted Cache Conflict Graph (TSCCG) is introduced to model the behavior of Data Cache (D-Cache) conflicts within each time slot. Then, Integer Nonlinear Programming (INP) is implemented, which can avoid time-consuming linearization process, to select the most profitable data pages. Virtual Memory System (VMS) is adopted to remap those data pages, which will cause severe Cache conflicts within a time slot, to SPM. In order to minimize the swapping overhead of dynamic SPM allocation, a novel SPM controller with a tightly coupled DMA is introduced to issue the swapping operations without CPU's intervention. Last but not the least, this paper discusses the fluctuation of system energy profit based on different MMU page size as well as the Time Slot duration quantitatively. According to our design space exploration, the proposed method can optimize all of the data segments, including global data, heap and stack data in general, and reduce the total energy consumption by 27.28% on average, up to 55.22% with a marginal performance promotion. And comparing to the conventional static CCG (Cache Conflicts Graph), our approach can obtain 24.7% energy profit on average, up to 30.5% with a sight boost in performance.
Optimal distributed resource allocation in a wireless sensor network for control systems
Institute of Scientific and Technical Information of China (English)
MAO Jian-lin; WU Zhi-ming
2007-01-01
Wireless technology is applied increasingly in networked control systems. A new form of wireless network called wireless sensor network can bring control systems some advantages, such as flexibility and feasibility of network deployment at low costs, while it also raises some new challenges. First, the communication resources shared by all the control loops are limited.Second, the wireless and multi-hop character of sensor network makes the resources scheduling more difficult. Thus, how to effectively allocate the limited communication resources for those control loops is an important problem. In this paper, this problem is formulated as an optimal sampling frequency assignment problem, where the objective function is to maximize the utility of control systems, subject to channel capacity constraints. Then an iterative distributed algorithm based on local buffer information is proposed. Finally, the simulation results show that the proposed algorithm can effectively allocate the limited communication resource in a distributed way. It can achieve the optimal quality of the control system and adapt to the network load changes.
Optimal Power Allocation of a Wireless Sensor Node under Different Rate Constraints
Solares, Jose
2011-07-01
Wireless sensor networks consist of the placement of sensors over a broad area in order to acquire data. Depending on the application, different design criteria should be considered in the construction of the sensors but among all of them, the battery life-cycle is of crucial interest. Power minimization is a problem that has been addressed from different approaches which include an analysis from an architectural perspective and with bit error rate and/or discrete instantaneous transmission rate constraints, among others. In this work, the optimal transmit power of a sensor node while satisfying different rate constraints is derived. First, an optimization problem with an instantaneous transmission rate constraint is addressed. Next, the optimal power is analyzed, but now with an average transmission rate constraint. The optimal solution for a class of fading channels, in terms of system parameters, is presented and a suboptimal solution is also proposed for an easier, yet efficient, implementation. Insightful asymptotical analysis for both schemes, considering a Rayleigh fading channel, are shown. Furthermore, the optimal power allocation for a sensor node in a cognitive radio environment is analyzed where an optimum solution for a class of fading channels is again derived. In all cases, numerical results are provided for either Rayleigh or Nakagami-m fading channels. The results obtained are extended to scenarios where we have either one transmitter-multiple receivers or multiple transmitters-one receiver.
Institute of Scientific and Technical Information of China (English)
孙毅; 骆书剑; 吴润泽; 唐良瑞
2012-01-01
Based on the characteristics of the Ethernet Passive Optical Network (EPON) and the requirements of smart distribution grid, a novel dynamic bandwidth allocation (DBA) scheme of EPON in distribution communication network is proposed. Using the high-order moving average model, the novel scheme predicts the amount of high-priority traffic arriving during the waiting period, so as to ensure the performance of high priority services and prevent the lower priority traffic from being delayed for multiple cycle times. After that, the Round-Robin scheduling algorithm, which balances the fairness and efficiency of bandwidth allocation, is applied to authorize the ONUs of high loads in advance. Simulation results show that the scheme proposed in this paper can improve the performance on average delay, increase the network throughput and decrease the rate of packet loss.%结合以太无源光网络( EPON)的技术特点及智能配电网对通信系统的需求,设计了一种可用于配电通信网的EPON带宽分配方案.利用高阶移动平均模型,对高优先级业务在等待时隙中额外收到的流量进行预测并分配授权带宽,保证了高优先级业务性能,杜绝了较低优先级业务分配的时隙被挤占的现象.采用Round-Robin调度算法对处于高负载下的ONU进行提前发送,显著提高了系统整体性能并兼顾了分配的公平性.理论分析和仿真结果表明,所提出的动态带宽分配方案能够显著提高业务延时性能,增加网络吞吐量,并降低网络丢包率.
Maser, Adam Charles
work losses over the time history of the mission. The characterization of the thermodynamic irreversibility distribution helps give the propulsion systems designer an absolute and consistent view of the tradeoffs associated with the design of the entire integrated system. Consequently, this leads directly to the question of the proper allocation of irreversibility across each of the components. The process of searching for the most favorable allocation of this irreversibility is the central theme of the research and must take into account production cost and vehicle mission performance. The production cost element is accomplished by including an engine component weight and cost prediction capability within the system model. The vehicle mission performance is obtained by directly linking the propulsion and thermal management model to a vehicle performance model and flying it through a mission profile. A canonical propulsion and thermal management systems architecture is then presented to experimentally test each element of the methodology separately: first the integrated modeling and simulation, then the irreversibility, cost, and mission performance considerations, and then finally the proper technique to perform the optimal allocation. A goal of this research is the description of the optimal allocation of system irreversibility to enable an engine cycle design with improved performance and cost at the vehicle-level. To do this, a numerical optimization was first used to minimize system-level production and operating costs by fixing the performance requirements and identifying the best settings for all of the design variables. There are two major drawbacks to this approach: It does not allow the designer to directly trade off the performance requirements and it does not allow the individual component losses to directly factor into the optimization. An irreversibility allocation approach based on the economic concept of resource allocation is then compared to the
Directory of Open Access Journals (Sweden)
Neeraj Kanwar
2015-01-01
Full Text Available This paper addresses a new methodology for the simultaneous optimal allocation of DSTATCOM and DG in radial distribution systems to maximize power loss reduction while maintaining better node voltage profiles under multilevel load profile. Cat Swarm Optimization (CSO is one of the recently developed powerful swarm intelligence-based optimization techniques that mimics the natural behavior of cats but usually suffers from poor convergence and accuracy while subjected to large dimension problem. Therefore, an Improved CSO (ICSO technique is proposed to efficiently solve the problem where the seeking mode of CSO is modified to enhance its exploitation potential. In addition, the problem search space is virtually squeezed by suggesting an intelligent search approach which smartly scans the problem search space. Further, the effect of network reconfiguration has also been investigated after optimally placing DSTATCOMs and DGs in the distribution network. The suggested measures enhance the convergence and accuracy of the algorithm without loss of diversity. The proposed method is investigated on 69-bus test distribution system and the application results are very promising for the operation of smart distribution systems.
CONGESTION MANAGEMENT BY OPTIMAL ALLOCATION OF FACTS CONTROLLERS USING HYBRID FISH BEE OPTIMIZATION
Directory of Open Access Journals (Sweden)
S. Thangalakshmi
2014-01-01
Full Text Available The role of Independent System Operator (ISO in the restructured power industry includes system control, capacity planning, transmission tariff and congestion management; the challenging task being minimizing the congestion. One of the popular techniques used to alleviate congestion is using Flexible AC Transmission Systems (FACTS devices. The power system generally operates near its rated capacity in deregulated market because of intensive usage of transmission grids. So, the major issues that need to be addressed are improving the voltage profile and reducing the power loss in the electrical network. Motivation: The location of FACTS devices can improve the power flow in the line, maintain the bus profile and reduce the losses. However locating the ideal location is a NP problem. This study presents a novel heuristic method to determine the types of FACTS devices and its optimal location in a power system without violating the thermal and voltage limits. Power flow sensitivity index to find the optimal location of UPFC is suggested in this study. A hybrid fish bee swarm optimization is proposed which is based on Artificial Bee Colony (ABC and Fish School Search (FSS methods. This proposed algorithm is tested based on IEEE 30 bus system and line performances are studied.
Kang, Xin; Nallanathan, Arumugam; Garg, Hari Krishna; Zhang, Rui
2008-01-01
A cognitive radio network (CRN) is formed by either allowing the secondary users (SUs) in a secondary communication network (SCN) to opportunistically operate in the frequency bands originally allocated to a primary communication network (PCN) or by allowing SCN to coexist with the primary users (PUs) in PCN as long as the interference caused by SCN to each PU is properly regulated. In this paper, we consider the latter case, known as spectrum sharing, and study the optimal power allocation strategies to achieve the ergodic capacity and the outage capacity of the SU fading channel under different types of power constraints and fading channel models. In particular, besides the interference power constraint at PU, the transmit power constraint of SU is also considered. Since the transmit power and the interference power can be limited either by a peak or an average constraint, various combinations of power constraints are studied. It is shown that there is a capacity gain for SU under the average over the peak ...
Optimal rate allocation for joint compression and classification in JPEG 2000
Tabesh, Ali; Marcellin, Michael W.; Neifeld, Mark A.
2004-11-01
We present a framework for optimal rate allocation to image subbands to minimize the distortion in the joint compression and classification of JPEG2000-compressed images. The distortion due to compression is defined as a weighted linear combination of the mean-square error (MSE) and the loss in the Bhattacharyya distance (BD) between the class-conditional distributions of the classes. Lossy compression with JPEG2000 is accomplished via deadzone uniform quantization of wavelet subbands. Neglecting the effect of the deadzone, expressions are derived for the distortion in the case of two classes with generalized Gaussian distributions (GGDs), based on the high-rate analysis of Poor. In this regime, the distortion function takes the form of a weighted MSE (WMSE) function, which can be minimized using reverse water-filling. We present experimental results based on synthetic data to evaluate the efficacy of the proposed rate allocation scheme. The results indicate that by varying the weight factor balancing the MSE and the Bhattacharyya distance, we can control the trade-off between these two terms in the distortion function.
Two interactive and practical methods for optimization of tracker allocation in a given land
Araki, Kenji
2012-10-01
The purpose of this paper is proposals of two interactive methods of tracker allocation effective to relatively smaller installation. Interaction helps designers to consider every detail of the limitation and possibly more accurate approach to the project of narrow land space rather than blindly relying mathematical optimum calculation. One is Overlay of skewed rectangular mesh method. This is a simple implementation of classical optimization calculation to interactive environment. Another is Butterfly method. The idea of using butterfly pattern was first invented by Spanish engineer, Dobon, and often called Dobon's butterfly in European regions. The original definition is the contour plot on the influence shading from a single tracker. We have improved this method for interactive design tool.
Near optimal power allocation algorithm for OFDM-based cognitive using adaptive relaying strategy
Soury, Hamza
2012-01-01
Relayed transmission increases the coverage and achievable capacity of communication systems. Adaptive relaying scheme is a relaying technique by which the benefits of the amplifying or decode and forward techniques can be achieved by switching the forwarding technique according to the quality of the signal. A cognitive Orthogonal Frequency-Division Multiplexing (OFDM) based adaptive relaying protocol is considered in this paper. The objective is to maximize the capacity of the cognitive radio system while ensuring that the interference introduced to the primary user is below the tolerated limit. A Near optimal power allocation in the source and the relay is presented for two pairing techniques such that the matching and random pairing. The simulation results confirm the efficiency of the proposed adaptive relaying protocol, and the consequence of choice of pairing technique. © 2012 ICST.
Optimal Power Allocation for GSVD-Based Beamforming in the MIMO Wiretap Channel
Fakoorian, S Ali A
2010-01-01
This paper considers a multiple-input multiple-output (MIMO) Gaussian wiretap channel model, where there exists a transmitter, a legitimate receiver and an eavesdropper, each equipped with multiple antennas. Perfect secrecy is achieved when the transmitter and the legitimate receiver can communicate at some positive rate, while ensuring that the eavesdropper gets zero bits of information. In this paper, the perfect secrecy capacity of the multiple antenna MIMO wiretap channel is found for aribtrary numbers of antennas under the assumption that the transmitter performs beamforming based on the generalized singular value decomposition (GSVD). More precisely, the optimal allocation of power for the GSVD-based precoder that achieves the secrecy capacity is derived. This solution is shown to have several advantages over prior work that considered secrecy capacity for the general MIMO Gaussian wiretap channel under a high SNR assumption. Numerical results are presented to illustrate the proposed theoretical finding...
Iterative receiver for ADO-OFDM with near-optimal optical power allocation
Bai, Ruowen; Jiang, Rui; Mao, Tianqi; Lei, Weilong; Wang, Zhaocheng
2017-03-01
Visible light communication (VLC) systems using orthogonal frequency division multiplexing (OFDM) are attracting increasing interests due to its inherent benefits such as high spectral efficiency, resistance to frequency-selective channels and so on. In this paper, a novel iterative receiver is proposed for asymmetrically clipped DC biased optical OFDM (ADO-OFDM), where asymmetrically clipped optical OFDM (ACO-OFDM) and DC biased OFDM (DCO-OFDM) signals are transmitted simultaneously. In our proposed iterative receiver, ACO-OFDM and DCO-OFDM time-domain signals are distinguished firstly. Then pairwise clipping, negative clipping and pairwise averaging are utilized in the iterative receiver to reduce the effect of noise and interference. In addition, an optimal solution to the optical power allocation factor for ACO-OFDM and DCO-OFDM signals is derived. Furthermore, to reduce the computational complexity, an approximation of the optimal solution is obtained. Both theoretical analysis and simulation results indicate that the approximate solution is near-optimal, and only a few detection iterations are required for the iterative receiver.
Optimal Capacity Allocation of Large-Scale Wind-PV-Battery Units
Directory of Open Access Journals (Sweden)
Kehe Wu
2014-01-01
Full Text Available An optimal capacity allocation of large-scale wind-photovoltaic- (PV- battery units was proposed. First, an output power model was established according to meteorological conditions. Then, a wind-PV-battery unit was connected to the power grid as a power-generation unit with a rated capacity under a fixed coordinated operation strategy. Second, the utilization rate of renewable energy sources and maximum wind-PV complementation was considered and the objective function of full life cycle-net present cost (NPC was calculated through hybrid iteration/adaptive hybrid genetic algorithm (HIAGA. The optimal capacity ratio among wind generator, PV array, and battery device also was calculated simultaneously. A simulation was conducted based on the wind-PV-battery unit in Zhangbei, China. Results showed that a wind-PV-battery unit could effectively minimize the NPC of power-generation units under a stable grid-connected operation. Finally, the sensitivity analysis of the wind-PV-battery unit demonstrated that the optimization result was closely related to potential wind-solar resources and government support. Regions with rich wind resources and a reasonable government energy policy could improve the economic efficiency of their power-generation units.
Giordano, Nils; Mairet, Francis; Gouzé, Jean-Luc
2016-01-01
Microbial physiology exhibits growth laws that relate the macromolecular composition of the cell to the growth rate. Recent work has shown that these empirical regularities can be derived from coarse-grained models of resource allocation. While these studies focus on steady-state growth, such conditions are rarely found in natural habitats, where microorganisms are continually challenged by environmental fluctuations. The aim of this paper is to extend the study of microbial growth strategies to dynamical environments, using a self-replicator model. We formulate dynamical growth maximization as an optimal control problem that can be solved using Pontryagin’s Maximum Principle. We compare this theoretical gold standard with different possible implementations of growth control in bacterial cells. We find that simple control strategies enabling growth-rate maximization at steady state are suboptimal for transitions from one growth regime to another, for example when shifting bacterial cells to a medium supporting a higher growth rate. A near-optimal control strategy in dynamical conditions is shown to require information on several, rather than a single physiological variable. Interestingly, this strategy has structural analogies with the regulation of ribosomal protein synthesis by ppGpp in the enterobacterium Escherichia coli. It involves sensing a mismatch between precursor and ribosome concentrations, as well as the adjustment of ribosome synthesis in a switch-like manner. Our results show how the capability of regulatory systems to integrate information about several physiological variables is critical for optimizing growth in a changing environment. PMID:26958858
Optimal DG Source Allocation for Grid Connected Distributed Generation with Energy Storage System
Directory of Open Access Journals (Sweden)
S. Ezhilarasan
2015-05-01
Full Text Available This study proposes an Energy Management System (EMS for allocation of DG source in a grid connected hybrid power system. Modeling and simulation for EMS is implemented using MATLAB/SIMULINK package. The objective of proposed EMS for micro grid is to optimize the fuel cost, improving the energy utilization efficiency and to manage the peak load demand by scheduling the generation according to the availability of the fuel. The proposed intelligent energy management system is designed to optimize the availability of energy to the load according to the level of priority and to manage the power flow. The developed management system performance was assessed using a hybrid system having PV panels, Wind Turbine (WT, battery and biomass gasifier. Real time field test has been conducted and the parameters i.e., solar irradiance, temperature, wind speed are gathered from 4.05 KW off grid and 2.0 KW On grid Solar Photovoltaic systems (SPV system and wind turbine. The dynamic behavior of the proposed model is examined under different operating conditions. The simulation results of proposed EMS using fuzzy logic expert system shows the minimization on the operating cost and emission level of micro grid by optimal scheduling of power generation and maintains the State of Charge (SOC of batteries in desired value which improves the battery life. The proposed multi objective intelligent energy management system aims to minimize the operational cost and the environmental impact of a micro grid.
Maximally Distant Codes Allocation Using Chemical Reaction Optimization with Enhanced Exploration
Directory of Open Access Journals (Sweden)
Taisir Eldos
2016-01-01
Full Text Available Error correcting codes, also known as error controlling codes, are sets of codes with redundancy that provides for error detection and correction, for fault tolerant operations like data transmission over noisy channels or data retention using storage media with possible physical defects. The challenge is to find a set of m codes out of 2n available n-bit combinations, such that the aggregate hamming distance among those codewords and/or the minimum distance is maximized. Due to the prohibitively large solution spaces of practically sized problems, greedy algorithms are used to generate quick and dirty solutions. However, modern evolutionary search techniques like genetic algorithms, swarm particles, gravitational search, and others, offer more feasible solutions, yielding near optimal solutions in exchange for some computational time. The Chemical Reaction Optimization (CRO, which is inspired by the molecular reactions towards a minimal energy state, emerged recently as an efficient optimization technique. However, like the other techniques, its internal dynamics are hard to control towards convergence, yielding poor performance in many situations. In this research, we proposed an enhanced exploration strategy to overcome this problem, and compared it with the standard threshold based exploration strategy in solving the maximally distant codes allocation problem. Test results showed that the enhancement provided better performance on most metrics.
Directory of Open Access Journals (Sweden)
Nils Giordano
2016-03-01
Full Text Available Microbial physiology exhibits growth laws that relate the macromolecular composition of the cell to the growth rate. Recent work has shown that these empirical regularities can be derived from coarse-grained models of resource allocation. While these studies focus on steady-state growth, such conditions are rarely found in natural habitats, where microorganisms are continually challenged by environmental fluctuations. The aim of this paper is to extend the study of microbial growth strategies to dynamical environments, using a self-replicator model. We formulate dynamical growth maximization as an optimal control problem that can be solved using Pontryagin's Maximum Principle. We compare this theoretical gold standard with different possible implementations of growth control in bacterial cells. We find that simple control strategies enabling growth-rate maximization at steady state are suboptimal for transitions from one growth regime to another, for example when shifting bacterial cells to a medium supporting a higher growth rate. A near-optimal control strategy in dynamical conditions is shown to require information on several, rather than a single physiological variable. Interestingly, this strategy has structural analogies with the regulation of ribosomal protein synthesis by ppGpp in the enterobacterium Escherichia coli. It involves sensing a mismatch between precursor and ribosome concentrations, as well as the adjustment of ribosome synthesis in a switch-like manner. Our results show how the capability of regulatory systems to integrate information about several physiological variables is critical for optimizing growth in a changing environment.
Multi-objective hierarchical genetic algorithms for multilevel redundancy allocation optimization
Energy Technology Data Exchange (ETDEWEB)
Kumar, Ranjan [Department of Aeronautics and Astronautics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)], E-mail: ranjan.k@ks3.ecs.kyoto-u.ac.jp; Izui, Kazuhiro [Department of Aeronautics and Astronautics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)], E-mail: izui@prec.kyoto-u.ac.jp; Yoshimura, Masataka [Department of Aeronautics and Astronautics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)], E-mail: yoshimura@prec.kyoto-u.ac.jp; Nishiwaki, Shinji [Department of Aeronautics and Astronautics, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)], E-mail: shinji@prec.kyoto-u.ac.jp
2009-04-15
Multilevel redundancy allocation optimization problems (MRAOPs) occur frequently when attempting to maximize the system reliability of a hierarchical system, and almost all complex engineering systems are hierarchical. Despite their practical significance, limited research has been done concerning the solving of simple MRAOPs. These problems are not only NP hard but also involve hierarchical design variables. Genetic algorithms (GAs) have been applied in solving MRAOPs, since they are computationally efficient in solving such problems, unlike exact methods, but their applications has been confined to single-objective formulation of MRAOPs. This paper proposes a multi-objective formulation of MRAOPs and a methodology for solving such problems. In this methodology, a hierarchical GA framework for multi-objective optimization is proposed by introducing hierarchical genotype encoding for design variables. In addition, we implement the proposed approach by integrating the hierarchical genotype encoding scheme with two popular multi-objective genetic algorithms (MOGAs)-the strength Pareto evolutionary genetic algorithm (SPEA2) and the non-dominated sorting genetic algorithm (NSGA-II). In the provided numerical examples, the proposed multi-objective hierarchical approach is applied to solve two hierarchical MRAOPs, a 4- and a 3-level problems. The proposed method is compared with a single-objective optimization method that uses a hierarchical genetic algorithm (HGA), also applied to solve the 3- and 4-level problems. The results show that a multi-objective hierarchical GA (MOHGA) that includes elitism and mechanism for diversity preserving performed better than a single-objective GA that only uses elitism, when solving large-scale MRAOPs. Additionally, the experimental results show that the proposed method with NSGA-II outperformed the proposed method with SPEA2 in finding useful Pareto optimal solution sets.
Cogoni, Marco; Busonera, Giovanni; Anedda, Paolo; Zanetti, Gianluigi
2015-01-01
We generalize previous studies on critical phenomena in communication networks [1,2] by adding computational capabilities to the nodes. In our model, a set of tasks with random origin, destination and computational structure is distributed on a computational network, modeled as a graph. By varying the temperature of a Metropolis Montecarlo, we explore the global latency for an optimal to suboptimal resource assignment at a given time instant. By computing the two-point correlation function for the local overload, we study the behavior of the correlation distance (both for links and nodes) while approaching the congested phase: a transition from peaked to spread g(r) is seen above a critical (Montecarlo) temperature Tc. The average latency trend of the system is predicted by averaging over several network traffic realizations while maintaining a spatially detailed information for each node: a sharp decrease of performance is found over Tc independently of the workload. The globally optimized computational resource allocation and network routing defines a baseline for a future comparison of the transition behavior with respect to existing routing strategies [3,4] for different network topologies.
Gao, Yuan; Zhou, Weigui; Ao, Hong; Chu, Jian; Zhou, Quan; Zhou, Bo; Wang, Kang; Li, Yi; Xue, Peng
2016-01-01
With the increasing demands for better transmission speed and robust quality of service (QoS), the capacity constrained backhaul gradually becomes a bottleneck in cooperative wireless networks, e.g., in the Internet of Things (IoT) scenario in joint processing mode of LTE-Advanced Pro. This paper focuses on resource allocation within capacity constrained backhaul in uplink cooperative wireless networks, where two base stations (BSs) equipped with single antennae serve multiple single-antennae users via multi-carrier transmission mode. In this work, we propose a novel cooperative transmission scheme based on compress-and-forward with user pairing to solve the joint mixed integer programming problem. To maximize the system capacity under the limited backhaul, we formulate the joint optimization problem of user sorting, subcarrier mapping and backhaul resource sharing among different pairs (subcarriers for users). A novel robust and efficient centralized algorithm based on alternating optimization strategy and perfect mapping is proposed. Simulations show that our novel method can improve the system capacity significantly under the constraint of the backhaul resource compared with the blind alternatives. PMID:27077865
Gao, Yuan; Zhou, Weigui; Ao, Hong; Chu, Jian; Zhou, Quan; Zhou, Bo; Wang, Kang; Li, Yi; Xue, Peng
2016-04-12
With the increasing demands for better transmission speed and robust quality of service (QoS), the capacity constrained backhaul gradually becomes a bottleneck in cooperative wireless networks, e.g., in the Internet of Things (IoT) scenario in joint processing mode of LTE-Advanced Pro. This paper focuses on resource allocation within capacity constrained backhaul in uplink cooperative wireless networks, where two base stations (BSs) equipped with single antennae serve multiple single-antennae users via multi-carrier transmission mode. In this work, we propose a novel cooperative transmission scheme based on compress-and-forward with user pairing to solve the joint mixed integer programming problem. To maximize the system capacity under the limited backhaul, we formulate the joint optimization problem of user sorting, subcarrier mapping and backhaul resource sharing among different pairs (subcarriers for users). A novel robust and efficient centralized algorithm based on alternating optimization strategy and perfect mapping is proposed. Simulations show that our novel method can improve the system capacity significantly under the constraint of the backhaul resource compared with the blind alternatives.
Directory of Open Access Journals (Sweden)
Xin Wu
2010-01-01
Full Text Available In cellular networks, it is important to determine an optimal channel assignment scheme so that the available channels, which are considered as “limited” resources in cellular networks, are used as efficiently as possible. The objective of the channel assignment scheme is to minimize the call-blocking and the call-dropping probabilities. In this paper, we present two efficient integer linear programming (ILP formulations, for optimally allocating a channel (from a pool of available channels to an incoming call such that both “hard” and “soft” constraints are satisfied. Our first formulation, ILP1, does not allow channel reassignment of the existing calls, while our second formulation, ILP2, allows such reassignment. Both formulations can handle hard constraints, which includes co-site and adjacent channel constraints, in addition to the standard co-channel constraints. The simplified problem (with only co-channel constraints can be treated as a special case of our formulation. In addition to the hard constraints, we also consider soft constraints, such as, the packing condition, resonance condition, and limiting rearrangements, to further improve the network performance. We present the simulation results on a benchmark 49 cell environment with 70 channels that validate the performance of our approach.
Optimizing the location-allocation problem of pharmacy warehouses: A case study in Gaziantep
Directory of Open Access Journals (Sweden)
Eren Özceylan
2017-01-01
Full Text Available It is a known fact that basic health care services cannot reach the majority of the population due to poor geographical accessibility. Unless quantitative location-allocation models and geographic information systems (GIS are used, the final decision may be made on pragmatic considerations which can result far from optimal. In this paper, current and possible (or potential new locations of pharmacy warehouses in Gaziantep are investigated to provide optimal distribution of hospitals and pharmacies. To do so, first of all, geographic information of 10 current and 10 potential pharmacy warehouses, 231 pharmacies and 29 hospitals are gathered using GIS. Second, a set covering mathematical model is handled to determine coverage capability of current and potential pharmacy warehouses and minimize the number of warehouses to be opened. Finally, P-center and P-median mathematical models are applied to open potential warehouses and to assign pharmacies & hospitals to the opened warehouses so that the total distance and the demand’s longest distance to the source are minimized. Developed integer programming (IP models and GIS software are compared with on a case study. Computational experiments prove that our approach can find new potential pharmacy warehouses which cover wider areas than current warehouses to service pharmacies and hospitals in the city.
Wajnberg, Eric; Coquillard, Patrick; Vet, Louise E M; Hoffmeister, Thomas
2012-01-01
Expansion and intensification of human land use represents the major cause of habitat fragmentation. Such fragmentation can have dramatic consequences on species richness and trophic interactions within food webs. Although the associated ecological consequences have been studied by several authors, the evolutionary effects on interacting species have received little research attention. Using a genetic algorithm, we quantified how habitat fragmentation and environmental variability affect the optimal reproductive strategies of parasitic wasps foraging for hosts. As observed in real animal species, the model is based on the existence of a negative trade-off between survival and reproduction resulting from competitive allocation of resources to either somatic maintenance or egg production. We also asked to what degree plasticity along this trade-off would be optimal, when plasticity is costly. We found that habitat fragmentation can indeed have strong effects on the reproductive strategies adopted by parasitoids. With increasing habitat fragmentation animals should invest in greater longevity with lower fecundity; yet, especially in unpredictable environments, some level of phenotypic plasticity should be selected for. Other consequences in terms of learning ability of foraging animals were also observed. The evolutionary consequences of these results are discussed.
Directory of Open Access Journals (Sweden)
Eric Wajnberg
Full Text Available Expansion and intensification of human land use represents the major cause of habitat fragmentation. Such fragmentation can have dramatic consequences on species richness and trophic interactions within food webs. Although the associated ecological consequences have been studied by several authors, the evolutionary effects on interacting species have received little research attention. Using a genetic algorithm, we quantified how habitat fragmentation and environmental variability affect the optimal reproductive strategies of parasitic wasps foraging for hosts. As observed in real animal species, the model is based on the existence of a negative trade-off between survival and reproduction resulting from competitive allocation of resources to either somatic maintenance or egg production. We also asked to what degree plasticity along this trade-off would be optimal, when plasticity is costly. We found that habitat fragmentation can indeed have strong effects on the reproductive strategies adopted by parasitoids. With increasing habitat fragmentation animals should invest in greater longevity with lower fecundity; yet, especially in unpredictable environments, some level of phenotypic plasticity should be selected for. Other consequences in terms of learning ability of foraging animals were also observed. The evolutionary consequences of these results are discussed.
Optimal Plant Carbon Allocation Implies a Biological Control on Nitrogen Availability
Prentice, I. C.; Stocker, B. D.
2015-12-01
The degree to which nitrogen availability limits the terrestrial C sink under rising CO2 is a key uncertainty in carbon cycle and climate change projections. Results from ecosystem manipulation studies and meta-analyses suggest that plant C allocation to roots adjusts dynamically under varying degrees of nitrogen availability and other soil fertility parameters. In addition, the ratio of biomass production to GPP appears to decline under nutrient scarcity. This reflects increasing plant C exudation into the soil (Cex) with decreasing nutrient availability. Cex is consumed by an array of soil organisms and may imply an improvement of nutrient availability to the plant. Thus, N availability is under biological control, but incurs a C cost. In spite of clear observational support, this concept is left unaccounted for in Earth system models. We develop a model for the coupled cycles of C and N in terrestrial ecosystems to explore optimal plant C allocation under rising CO2 and its implications for the ecosystem C balance. The model follows a balanced growth approach, accounting for the trade-offs between leaf versus root growth and Cex in balancing C fixation and N uptake. We assume that Cex is proportional to root mass, and that the ratio of N uptake (Nup) to Cex is proportional to inorganic N concentration in the soil solution. We further assume that Cex is consumed by N2-fixing processes if the ratio of Nup:Cex falls below the inverse of the C cost of N2-fixation. Our analysis thereby accounts for the feedbacks between ecosystem C and N cycling and stoichiometry. We address the question of how the plant C economy will adjust under rising atmospheric CO2 and what this implies for the ecosystem C balance and the degree of N limitation.
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G. Chandra Sekhar
2013-01-01
Full Text Available In this paper, authors presented a price maximization scheme for optimal orthogonal frequency division for multiple access (OFDMA subcarrier allocation for wireless video unicast/multicast scenarios. They formulate a pricing based video utility function for H.264 based wireless scalable video streaming, thereby achieving a trade-off between price and QoS fairness. These parametric models for scalable video rate and quality characterization arederived from the standard JSVM reference codec for the SVC extension of the H.264/AVC, and hence are directly applicable in practical wireless scenarios. With the aid of these models, they proposed auction based framework for revenue maximization of the transmitted video streams in the unicast and multicast 4G scenario. A closedform expression is derived for the optimal scalable video quantization step-size subject to the constraints of theunicast/multicast users in 4G wireless systems. This yields the optimal OFDMA subcarrier allocation for multi-userscalable video multiplexing. The proposed scheme is cognizant of the user modulation and code rate, and is henceamenable to adaptive modulation and coding (AMC feature of 4G wireless networks. Further, they also consider aframework for optimal power allocation based on a novel revenue maximization scheme in OFDMA based wireless broadband 4G systems employing auction bidding models. This is formulated as a constrained convex optimization problem towards sum video utility maximization. We observe that as the demand for a video stream increases inbroadcast/multicast scenarios, higher power is allocated to the corresponding video stream leading to a gain in the overall revenue/utility. We simulate a standard WiMAX based 4G video transmission scenario to validate the performance of the proposed optimal 4G scalable video resource allocation schemes. Simulations illustrate that the proposed optimal band width and power allocation schemes result in a significant
Topology optimization of photonic crystal structures: a high-bandwidth low-loss T-junction waveguide
DEFF Research Database (Denmark)
Jensen, Jakob Søndergaard; Sigmund, Ole
2005-01-01
A T junction in a photonic crystal waveguide is designed with the topology-optimization method. The gradientbased optimization tool is used to modify the material distribution in the junction area so that the power transmission in the output ports is maximized. To obtain high transmission...
DEFF Research Database (Denmark)
Steiner, Uli; Pfeiffer, Thomas
2007-01-01
Prey organisms are confronted with time and resource allocation trade-offs. Time allocation trade-offs partition time, for example, between foraging effort to acquire resources and behavioral defense. Resource allocation trade-offs partition the acquired resources between multiple traits, such as...... for and augment each other depending on predator densities and the effectiveness of the defense mechanisms. In the presence of time constraints, the model shows peak investment into morphological and behavioral defense at intermediate resource levels....
Xu, Ding; Li, Qun
2017-01-01
This paper addresses the power allocation problem for cognitive radio (CR) based on hybrid-automatic-repeat-request (HARQ) with chase combining (CC) in Nakagamimslow fading channels. We assume that, instead of the perfect instantaneous channel state information (CSI), only the statistical CSI is available at the secondary user (SU) transmitter. The aim is to minimize the SU outage probability under the primary user (PU) interference outage constraint. Using the Lagrange multiplier method, an iterative and recursive algorithm is derived to obtain the optimal power allocation for each transmission round. Extensive numerical results are presented to illustrate the performance of the proposed algorithm.
Delay-Optimal Power and Subcarrier Allocation for OFDMA Systems via Stochastic Approximation
Lau, Vincent K N
2009-01-01
In this paper, we consider delay-optimal power and subcarrier allocation design for OFDMA systems with $N_F$ subcarriers, $K$ mobiles and one base station. There are $K$ queues at the base station for the downlink traffic to the $K$ mobiles with heterogeneous packet arrivals and delay requirements. We shall model the problem as a $K$-dimensional infinite horizon average reward Markov Decision Problem (MDP) where the control actions are assumed to be a function of the instantaneous Channel State Information (CSI) as well as the joint Queue State Information (QSI). This problem is challenging because it corresponds to a stochastic Network Utility Maximization (NUM) problem where general solution is still unknown. We propose an {\\em online stochastic value iteration} solution using {\\em stochastic approximation}. The proposed power control algorithm, which is a function of both the CSI and the QSI, takes the form of multi-level water-filling. We prove that under two mild conditions in Theorem 1 (One is the steps...
Directory of Open Access Journals (Sweden)
K. Rajeswari
2015-04-01
Full Text Available A novel hybrid channel estimator is proposed for multiple-input multiple-output orthogonal frequency- division multiplexing (MIMO-OFDM system with per-subcarrier transmit antenna selection having optimal power allocation among subcarriers. In practice, antenna selection information is transmitted through a binary symmetric control channel with a crossover probability. Linear minimum mean-square error (LMMSE technique is optimal technique for channel estimation in MIMO-OFDM system. Though LMMSE estimator performs well at low signal to noise ratio (SNR, in the presence of antenna-to-subcarrier-assignment error (ATSA, it introduces irreducible error at high SNR. We have proved that relaxed MMSE (RMMSE estimator overcomes the performance degradation at high SNR. The proposed hybrid estimator combines the benefits of LMMSE at low SNR and RMMSE estimator at high SNR. The vector mean square error (MSE expression is modified as scalar expression so that an optimal power allocation can be performed. The convex optimization problem is formulated and solved to allocate optimal power to subcarriers minimizing the MSE, subject to transmit sum power constraint. Further, an analytical expression for SNR threshold at which the hybrid estimator is to be switched from LMMSE to RMMSE is derived. The simulation results show that the proposed hybrid estimator gives robust performance, irrespective of ATSA error.
Quebbeman, J. A.; Ramirez, J. A.
2016-09-01
The maximum rate of carboxylation, Vcmax, and the maximum rate of electron transport, Jmax, describe leaf-level capacities of the photosynthetic system and are critical in determining the net fluxes of carbon dioxide and water vapor in the terrestrial biosphere. Although both Vcmax and Jmax exhibit high spatial and temporal variability, most descriptions of photosynthesis in terrestrial biosphere models assume constant values for Vcmax and Jmax at a reference temperature ignoring intraseasonal, interannual, and water stress-induced variations. Although general patterns of variation of Vcmax and Jmax have been correlated across groups of species, climates, and nitrogen concentrations, scant theoretical support has been provided to explain these variations. We present a new approach to determine Vcmax and Jmax based on the assumption that a limited amount of leaf nitrogen is allocated optimally among the various components of the photosynthetic system in such a way that expected carbon assimilation is maximized. The optimal allocation is constrained by available nitrogen and responds dynamically to the near-term environmental conditions of light and water supply and to their variability. The resulting optimal allocations of a finite supply of nitrogen replicate observed relationships in nature, including the ratio of Jmax/Vcmax, the relationship of leaf nitrogen to Vcmax, and the changes in nitrogen allocation under varying water availability and light environments. This optimal allocation approach provides a mechanism to describe the response of leaf-level photosynthetic capacity to varying environmental and resource supply conditions that can be incorporated into terrestrial biosphere models providing improved estimates of carbon and water fluxes in the soil-plant-atmosphere continuum.
Hu, Zhineng; Wei, Changting; Yao, Liming; Li, Ling; Li, Chaozhi
2016-11-01
Water scarcity is a global problem which causes economic and political conflicts as well as degradation of ecosystems. Moreover, the uncertainty caused by extreme weather increases the risk of economic inefficiency, an essential consideration for water users. In this study, a multi-objective model involving water allocation equality and economic efficiency risk control is developed to help water managers mitigate these problems. Gini coefficient is introduced to optimize water allocation equality in water use sectors (agricultural, domestic, and industrial sectors), and CVaR is integrated into the model constraints to control the economic efficiency loss risk corresponding to variations in water availability. The case study demonstrates the practicability and rationality of the developed model, allowing the river basin authority to determine water allocation strategies for a single river basin.
Climate, Agriculture, Energy and the Optimal Allocation of Global Land Use
Steinbuks, J.; Hertel, T. W.
2011-12-01
The allocation of the world's land resources over the course of the next century has become a pressing research question. Continuing population increases, improving, land-intensive diets amongst the poorest populations in the world, increasing production of biofuels and rapid urbanization in developing countries are all competing for land even as the world looks to land resources to supply more environmental services. The latter include biodiversity and natural lands, as well as forests and grasslands devoted to carbon sequestration. And all of this is taking place in the context of faster than expected climate change which is altering the biophysical environment for land-related activities. The goal of the paper is to determine the optimal profile for global land use in the context of growing commercial demands for food and forest products, increasing non-market demands for ecosystem services, and more stringent GHG mitigation targets. We then seek to assess how the uncertainty associated with the underlying biophysical and economic processes influences this optimal profile of land use, in light of potential irreversibility in these decisions. We develop a dynamic long-run, forward-looking partial equilibrium framework in which the societal objective function being maximized places value on food production, liquid fuels (including biofuels), timber production, forest carbon and biodiversity. Given the importance of land-based emissions to any GHG mitigation strategy, as well as the potential impacts of climate change itself on the productivity of land in agriculture, forestry and ecosystem services, we aim to identify the optimal allocation of the world's land resources, over the course of the next century, in the face of alternative GHG constraints. The forestry sector is characterized by multiple forest vintages which add considerable computational complexity in the context of this dynamic analysis. In order to solve this model efficiently, we have employed the
van Boxtel, A.
2001-01-01
Spontaneous pericranial electromyographic (EMG) activity is generally small and is contaminated by strong low-frequency artifacts. High-pass filtering should suppress artifacts but affect EMG signal power only minimally. In 24 subjects who performed a warned simple reaction time task, the optimal hi
Optimization of selection contribution and mate allocations in monoecious tree breeding populations
Directory of Open Access Journals (Sweden)
Waldmann Patrik
2009-11-01
Full Text Available Abstract Background The combination of optimized contribution dynamic selection and various mating schemes was investigated over seven generations for a typical tree breeding scenario. The allocation of mates was optimized using a simulated annealing algorithm for various object functions including random mating (RM, positive assortative mating (PAM and minimization of pair-wise coancestry between mates (MCM all combined with minimization of variance in family size and coancestry. The present study considered two levels of heritability (0.05 and 0.25, two restrictions on relatedness (group coancestry; 1 and 2% and two maximum permissible numbers of crosses in each generation (100 and 400. The infinitesimal genetic model was used to simulate the genetic architecture of the trait that was the subject of selection. A framework of the long term genetic contribution of ancestors was used to examine the impacts of the mating schemes on population parameters. Results MCM schemes produced on average, an increased rate of genetic gain in the breeding population, although the difference between schemes was small but significant after seven generations (up to 7.1% more than obtained with RM. In addition, MCM reduced the level of inbreeding by as much as 37% compared with RM, although the rate of inbreeding was similar after three generations of selection. PAM schemes yielded levels of genetic gain similar to those produced by RM, but the increase in the level of inbreeding was substantial (up to 43%. Conclusion The main reason why MCM schemes yielded higher genetic gains was the improvement in managing the long term genetic contribution of founders in the population; this was achieved by connecting unrelated families. In addition, the accumulation of inbreeding was reduced by MCM schemes since the variance in long term genetic contributions of founders was smaller than in the other schemes. Consequently, by combining an MCM scheme with an algorithm that
Zhang, Chenglong; Guo, Ping
2017-10-01
The vague and fuzzy parametric information is a challenging issue in irrigation water management problems. In response to this problem, a generalized fuzzy credibility-constrained linear fractional programming (GFCCFP) model is developed for optimal irrigation water allocation under uncertainty. The model can be derived from integrating generalized fuzzy credibility-constrained programming (GFCCP) into a linear fractional programming (LFP) optimization framework. Therefore, it can solve ratio optimization problems associated with fuzzy parameters, and examine the variation of results under different credibility levels and weight coefficients of possibility and necessary. It has advantages in: (1) balancing the economic and resources objectives directly; (2) analyzing system efficiency; (3) generating more flexible decision solutions by giving different credibility levels and weight coefficients of possibility and (4) supporting in-depth analysis of the interrelationships among system efficiency, credibility level and weight coefficient. The model is applied to a case study of irrigation water allocation in the middle reaches of Heihe River Basin, northwest China. Therefore, optimal irrigation water allocation solutions from the GFCCFP model can be obtained. Moreover, factorial analysis on the two parameters (i.e. λ and γ) indicates that the weight coefficient is a main factor compared with credibility level for system efficiency. These results can be effective for support reasonable irrigation water resources management and agricultural production.
Wang, Kezhi
2014-10-01
Bit error rate (BER) and outage probability for amplify-and-forward (AF) relaying systems with two different channel estimation methods, disintegrated channel estimation and cascaded channel estimation, using pilot-aided maximum likelihood method in slowly fading Rayleigh channels are derived. Based on the BERs, the optimal values of pilot power under the total transmitting power constraints at the source and the optimal values of pilot power under the total transmitting power constraints at the relay are obtained, separately. Moreover, the optimal power allocation between the pilot power at the source, the pilot power at the relay, the data power at the source and the data power at the relay are obtained when their total transmitting power is fixed. Numerical results show that the derived BER expressions match with the simulation results. They also show that the proposed systems with optimal power allocation outperform the conventional systems without power allocation under the same other conditions. In some cases, the gain could be as large as several dB\\'s in effective signal-to-noise ratio.
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A. Ayyasamy
2014-07-01
Full Text Available Large variations in network Quality of Service (QoS in terms of bandwidth, latency and jitter may occur during media transfer over mobile ad-hoc networks. Applications need to adapt their functionality according to dynamic change of their QoS update. This paper proposes an enhanced service based platform to provide adaptive network management services to higher level application layer components. The Context Aware Adaptive Service (COAAS is a middleware architecture for service adaptation based on ad hoc network and service awareness. COAAS is structured in such a way that it can provide QoS awareness to streaming applications as well manage dynamic ad hoc network resources using an adaptive channel allocation approach. The overall architecture of COAAS framework includes core components to connection establishment, connection monitor, connection controller and policy manager. Adaptive channel allocation defined as object based component helps in dynamic binding during run time implemented using JXTA and J2ME using CDC [15] toolkit to demonstrate the performance of a mobile setup as a conference application.
Cost Optimization Technique of Task Allocation in Heterogeneous Distributed Computing System
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Faizul Navi Khan
2013-11-01
Full Text Available A Distributed Computing System (DCS is a network of workstations, personal computer and /or other computing systems. Such system may be heterogeneous in the sense that the computing nodes may have different speeds and memory capacities. A DCS accepts tasks from users and executes different modules of these tasks on various nodes of the system. Task allocation in a DCS is a common problem and a good number of task allocation algorithms have been proposed in the literature. In such environment an application runs in a DCS can be accessible on every node present within the DCS. In such cases if number of tasks is less than or equal to available processors in the DCS, we can assign these task without any trouble. But this allocation becomes complicated when numbers of tasks are greater than the numbers of processors. The problem of task allocation for processing of ‘m’ tasks to ‘n’ processors (m>n in a DCS is addressed here through a new modified tasks allocation technique. The model, presented in this paper allocates the tasks to the processor of different processing capacity to increase the performance of the DCS. The technique presented in this paper is based on the consideration of processing cost of the task to the processors. We have tried a new technique to assign all the tasks as per the required availability of processors and their processing capacity so that all the tasks of application get execute in the DCS.
Agueh, Max; Diouris, Jean-François; Diop, Magaye; Devaux, François-Olivier; De Vleeschouwer, Christophe; Macq, Benoit
2008-12-01
Based on the analysis of real mobile ad hoc network (MANET) traces, we derive in this paper an optimal wireless JPEG 2000 compliant forward error correction (FEC) rate allocation scheme for a robust streaming of images and videos over MANET. The packet-based proposed scheme has a low complexity and is compliant to JPWL, the 11th part of the JPEG 2000 standard. The effectiveness of the proposed method is evaluated using a wireless Motion JPEG 2000 client/server application; and the ability of the optimal scheme to guarantee quality of service (QoS) to wireless clients is demonstrated.
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Benoit Macq
2008-07-01
Full Text Available Based on the analysis of real mobile ad hoc network (MANET traces, we derive in this paper an optimal wireless JPEG 2000 compliant forward error correction (FEC rate allocation scheme for a robust streaming of images and videos over MANET. The packet-based proposed scheme has a low complexity and is compliant to JPWL, the 11th part of the JPEG 2000 standard. The effectiveness of the proposed method is evaluated using a wireless Motion JPEG 2000 client/server application; and the ability of the optimal scheme to guarantee quality of service (QoS to wireless clients is demonstrated.
Institute of Scientific and Technical Information of China (English)
刘金山; 李楚霖; 胡适耕
2002-01-01
In this paper, the balanced economic growth path was considered in a new growth model with endogenous technical progress. It is not only obtained the optimal allocation about capital and labor between a goods-producing sector and a R&D Sector,but also the optimal value of saving rates. By discussing the effect of parameters, it are also got the following results: When the rate of time preference (discount factor) rising, the fractions of Capital and labor in the goods-producing sector will increase , the fractions in R&D sector and the saving rates will decrease; When the population grows rapidly, the result will be contrary.
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Pietro Rubino
2012-03-01
Full Text Available The potential effect of climate change on the optimal allocation of irrigation water was investigated for a Southern Italy district. The study was carried out on 5 representative crops (grapevine, olive, sugar beet, processing tomato, asparagus, considering six simulated climate change conditions, corresponding to three 30-year periods (2011-2040; 2041-2070; 2071-2100 for two greenhouse gas emission schemes proposed by IPCC (A2 and B1, plus the current climatic condition. The framework adopted was based on: i the modeling of crop yield response for increasing levels of water supply, under current and future climatic conditions, through a non-linear regression equation and ii the definition of the best water allocation by means of a mathematical optimization model written in GAMS. Total irrigation water (TIW volume was allowed to vary from a low total supply 10000 m3 to 7000000 m3, whilst a fixed surface, corresponding to that currently occupied in the studied district, was assigned to each crop. The economic return was studied in terms of Value of Production less the fixed and variable irrigation costs (VPlic. The TIW volume that maximized the VPlic of the whole district surface under the current climatic condition was 5697861 m3. The total volume was partitioned among the five crops as a function of the surface occupied: grapevine>olive>processing tomato>asparagus>sugar beet. Nevertheless, grapevine and olive received seasonal volumes corresponding only to 59 and 50% of total irrigation water requirements. On the contrary, processing tomato and asparagus received seasonal water volumes close to those fully satisfying irrigation water requirements (100% and 85% ETc. Future climatic conditions slightly differed from the current one for the expected optimal allocation. Under water shortage conditions (160000 m3 the whole irrigation water was allocated to the horticultural crops. Forecasted growing season features varied to a different extent in
Energy Technology Data Exchange (ETDEWEB)
Jebaraj, S.; Iniyan, S. [Anna University, Chennai (India). Dept. of Mechanical Engineering
2007-07-01
Development of an energy allocation model will help in the proper allocation of the energy sources in meeting the future energy demand in India. In this paper, an attempt has been made to develop a fuzzy-based linear programming optimal energy model that minimises the cost and determines the optimum allocation of different energy sources for the centralised and decentralised power generation in India. The potential, energy demand, efficiency, emission and carbon tax are used as constraints in the model. The model allocates the energy distribution pattern for the year 2020 in India. The results indicate that the energy distribution pattern would be 15,800 GWh (4%) from the coal-based plants, 85,400 GWh (20%) from the nuclear plants, 191,100 GWh (44%) from the hydro plants, 22,400 GWh (5%) from the wind turbine generators, 45,520 GWh (11%) from the biomass gasifier plants, 14,112 GWh (3%) from the biogas plants, 8400 GWh (2%) from the solid waste, 33,600 GWh (8%) from the cogeneration plants and 11,970 GWh (3%) from the mini-hydel plants, for the year 2020. A sensitivity analysis has been done to validate the OEAM model. This study will help in the formation of strategies for the effective utilisation of energy sources in India.
Energy Technology Data Exchange (ETDEWEB)
Jebaraj, S.; Iniyan, S. [Anna University, Chennai (India). Department of Mechanical Engineering
2004-08-15
Development of an energy allocation model will help in the proper allocation of the energy sources in meeting the future energy demand in India. In this paper, an attempt has been made to develop a fuzzy-based linear programming optimal energy model that minimises the cost and determines the optimum allocation of different energy sources for the centralised and decentralised power generation in India. The potential, energy demand, efficiency, emission and carbon tax are used as constraints in the model. The model allocates the energy distribution pattern for the year 2020 in India. The results indicate that the energy distribution pattern would be 15,800 GWh (4%) from the coal-based plants, 85 400 GWh (20%) from the nuclear plants, 191,100 GWh (44%) from the hydro plants, 22 400 GWh (5%) from the wind turbine generators, 45,520 GWh (11%) from the biomass gasifier plants, 14,112 GWh (3%) from the biogas plants, 8400 GWh (2%) from the solid waste, 33,600 GWh (8%) from the cogeneration plants and 11,970 GWh (3%) from the mini-hydel plants, for the year 2020. A sensitivity analysis has been done to validate the OEAM model. This study will help in the formation of strategies for the effective utilisation of energy sources in India.
Razurel, Pierre; Niayifar, Amin; Perona, Paolo
2017-04-01
Hydropower plays an important role in supplying worldwide energy demand where it contributes to approximately 16% of global electricity production. Although hydropower, as an emission-free renewable energy, is a reliable source of energy to mitigate climate change, its development will increase river exploitation. The environmental impacts associated with both small hydropower plants (SHP) and traditional dammed systems have been found to the consequence of changing natural flow regime with other release policies, e.g. the minimal flow. Nowadays, in some countries, proportional allocation rules are also applied aiming to mimic the natural flow variability. For example, these dynamic rules are part of the environmental guidance in the United Kingdom and constitute an improvement in comparison to static rules. In a context in which the full hydropower potential might be reached in a close future, a solution to optimize the water allocation seems essential. In this work, we present a model that enables to simulate a wide range of water allocation rules (static and dynamic) for a specific hydropower plant and to evaluate their associated economic and ecological benefits. It is developed in the form of a graphical user interface (GUI) where, depending on the specific type of hydropower plant (i.e., SHP or traditional dammed system), the user is able to specify the different characteristics (e.g., hydrological data and turbine characteristics) of the studied system. As an alternative to commonly used policies, a new class of dynamic allocation functions (non-proportional repartition rules) is introduced (e.g., Razurel et al., 2016). The efficiency plot resulting from the simulations shows the environmental indicator and the energy produced for each allocation policies. The optimal water distribution rules can be identified on the Pareto's frontier, which is obtained by stochastic optimization in the case of storage systems (e.g., Niayifar and Perona, submitted) and by
de Boer, Hugo Jan; Price, Charles A.; Wagner-Cremer, Friederike; Dekker, Stefan C.; Franks, Peter J.; Veneklaas, Erik J.
2015-04-01
Stomata on plant leaves are key traits in the regulation of terrestrial fluxes of water and carbon. The basic morphology of stomata consists of a diffusion pore and two guard cells that regulate the exchange of CO2 and water vapour between the leaf interior and the atmosphere. This morphology is common to nearly all land plants, yet stomatal size (defined as the area of the guard cell pair) and stomatal density (the number of stomata per unit area) range over three orders of magnitude across species. Evolution of stomatal sizes and densities is driven by selection pressure on the anatomical maximum stomatal conductance (gsmax), which determines the operational range of leaf gas exchange. Despite the importance of stomata traits for regulating leaf gas exchange, a quantitative understanding of the relation between adaptation of gsmax and the underlying co-evolution of stomatal sizes and densities is still lacking. Here we develop a theoretical framework for a scaling relationship between stomatal sizes and densities within the constraints set by the allocation of epidermal space and stomatal gas exchange. Our theory predicts an optimal scaling relationship that maximizes gsmax and minimizes epidermal space allocation to stomata. We test whether stomatal sizes and densities reflect this optimal scaling with a global compilation of stomatal trait data on 923 species reflecting most major clades. Our results show optimal scaling between stomatal sizes and densities across all species in the compiled data set. Our results also show optimal stomatal scaling across angiosperm species, but not across gymnosperm and fern species. We propose that the evolutionary flexibility of angiosperms to adjust stomatal sizes underlies their optimal allocation of leaf epidermal space to gas exchange.
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Shuang Rong
2015-12-01
Full Text Available Aiming to relieve the large amount of wind power curtailment during the heating period in the North China region, a thermal-electric decoupling (TED approach is proposed to both bring down the constraint of forced power output of combined heat and power plants and increase the electric load level during valley load times that assist the power grid in consuming more wind power. The operating principles of the thermal-electric decoupling approach is described, the mathematical model of its profits is developed, the constraint conditions of its operation are listed, also, an improved parallel conjugate gradient is utilized to bypass the saddle problem and accelerate the optimal speed. Numerical simulations are implemented and reveal an optimal allocation of TED which with a rated power of 280 MW and 185 MWh heat storage capacity are possible. This allocation of TED could bring approximately 16.9 billion Yuan of economic profit and consume more than 80% of the surplus wind energy which would be curtailed without the participation of TED. The results in this article verify the effectiveness of this method that could provide a referential guidance for thermal-electric decoupling system allocation in practice.
Hwang, E.; Kim, K.J.; Roijers, F.; Choi, B.D.
2009-01-01
In the centralized polling mode in IEEE 802.16e, a base station (BS) polls mobile stations (MSs) for bandwidth reservation in one of three polling modes; unicast, multicast, or broadcast pollings. In unicast polling, the BS polls each individual MS to allow to transmit a bandwidth request packet. Th
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Shima MohammadZadeh Dogahe
2015-01-01
Full Text Available A novel integrated model is proposed to optimize the redundancy allocation problem (RAP and the reliability-centered maintenance (RCM simultaneously. A system of both repairable and nonrepairable components has been considered. In this system, electronic components are nonrepairable while mechanical components are mostly repairable. For nonrepairable components, a redundancy allocation problem is dealt with to determine optimal redundancy strategy and number of redundant components to be implemented in each subsystem. In addition, a maintenance scheduling problem is considered for repairable components in order to identify the best maintenance policy and optimize system reliability. Both active and cold standby redundancy strategies have been taken into account for electronic components. Also, net present value of the secondary cost including operational and maintenance costs has been calculated. The problem is formulated as a biobjective mathematical programming model aiming to reach a tradeoff between system reliability and cost. Three metaheuristic algorithms are employed to solve the proposed model: Nondominated Sorting Genetic Algorithm (NSGA-II, Multiobjective Particle Swarm Optimization (MOPSO, and Multiobjective Firefly Algorithm (MOFA. Several test problems are solved using the mentioned algorithms to test efficiency and effectiveness of the solution approaches and obtained results are analyzed.
An application of data mining classification and bi-level programming for optimal credit allocation
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Seyed Mahdi Sadatrasou
2015-01-01
Full Text Available This paper investigates credit allocation policy making and its effect on economic development using bi-level programming. There are two challenging problems in bi-level credit allocation; at the first level government/public related institutes must allocate the credit strategically concerning sustainable development to regions and industrial sectors. At the second level, there are agent banks, which should allocate the credit tactically to individual applicants based on their own profitability and risk using their credit scoring models. There is a conflict of interest between these two stakeholders but the cooperation is inevitable. In this paper, a new bi-level programming formulation of the leader-follower game in association with sustainable development theory in the first level and data mining classifier at the second level is used to mathematically model the problem. The model is applied to a national development fund (NDF as a government related organization and one of its agent banks. A new algorithm called Bi-level Genetic fuzzy apriori Algorithm (BGFAA is introduced to solve the bilateral model. Experimental results are presented and compared with a unilateral policy making scenario by the leader. Findings show that although the objective functions of the leader are worse in the bilateral scenario but agent banks collaboration is attracted and guaranteed.
An Optimization Model for the Allocation of University Based Merit Aid
Sugrue, Paul K.
2010-01-01
The allocation of merit-based financial aid during the college admissions process presents postsecondary institutions with complex and financially expensive decisions. This article describes the application of linear programming as a decision tool in merit based financial aid decisions at a medium size private university. The objective defined for…
Optimal Allocation of Pandemic Influenza Vaccine Depends on Age, Risk and Timing
Mylius, S.D.; Hagenaars, T.H.J.; Lugner, A.K.; Wallinga, J.
2008-01-01
The limited production capacity for vaccines raises the question what the best strategy is for allocating the vaccine to mitigate an influenza pandemic. We developed an age-structured model for spread of an influenza pandemic and validated it against observations from the Asian flu pandemic. Two str
Kuiper, B.R.; Visser, H.G.; Heblij, S.
2011-01-01
This paper presents the development of a runway allocation planning tool that seeks to maximize the permissible number of flight operations into and out of an airport within a given annual noise budget. Although the model that underlies the planning tool is generic in nature, the tool has been custo
DEFF Research Database (Denmark)
Chen, Peiyuan; Siano, Pierluigi; Chen, Zhe;
2010-01-01
limit requirements. The method combines the Genetic Algorithm (GA), gradient-based constrained nonlinear optimization algorithm and sequential Monte Carlo simulation (MCS). The GA searches for the optimal locations and capacities of WTs. The gradient-based optimization finds the optimal power factor...
DEFF Research Database (Denmark)
Chen, Peiyuan; Siano, Pierluigi; Chen, Zhe
2010-01-01
limit requirements. The method combines the Genetic Algorithm (GA), gradient-based constrained nonlinear optimization algorithm and sequential Monte Carlo simulation (MCS). The GA searches for the optimal locations and capacities of WTs. The gradient-based optimization finds the optimal power factor...
Optimal Bandwidth Design and Performance Analysis of INS-aided PLL%INS辅助的PLL最优带宽设计及性能分析
Institute of Scientific and Technical Information of China (English)
汤霞清; 程旭维; 武萌; 高军强
2015-01-01
In order to steadily track carrier signal under high dynamic or low C/N0 (Carrier to Noise Power Ratio)environments,during tracking loop of Global Navigation Satellite System (GNSS)receivers’de-sign stage,the Inertial Navigation System (INS)-aided Phase Lock Loop (PLL)structure is adopted. The error sources of the INS-aided PLL is built and the influence of inertial device’s accuracy on the tracking error is analyzed.Then,an optimal loop bandwidth design method is proposed based on the principle of minimizing the tracking error,and PLL bandwidth can be adjusted adaptively according to C/N0 of carrier signals to make the loop work all the time in minimum error state.The results show that the PLL tracking error is significantly decreased by aiding of INS,and the tracking accuracy is improved un-der challenged environments.%为实现对高动态和低载噪比信号的稳定跟踪，在全球导航卫星系统（Global Navigation Satellite System， GNSS）接收机的跟踪环路设计中采用惯性导航系统（Inertial Navigation System，INS）辅助锁相环（Phase Lock Loop，PLL）的环路结构。对 INS 辅助环路的各误差源进行了建模与分析，并分析了惯性器件精度对跟踪误差的影响。基于跟踪误差最小的原则设计了最优环路带宽，根据载波信号的载噪比和环路动态实时自适应地调整 PLL 带宽，使环路始终工作在最小误差状态。结果表明：所设计 INS 辅助的自适应带宽调节方法能有效减小环路跟踪误差，并提高复杂环境下信号的跟踪精度。
Leonard, Michael W.
2013-01-01
Integration of the Control Allocation technique to recover from Pilot Induced Oscillations (CAPIO) System into the control system of a Short Takeoff and Landing Mobility Concept Vehicle simulation presents a challenge because the CAPIO formulation requires that constrained optimization problems be solved at the controller operating frequency. We present a solution that utilizes a modified version of the well-known L-BFGS-B solver. Despite the iterative nature of the solver, the method is seen to converge in real time with sufficient reliability to support three weeks of piloted runs at the NASA Ames Vertical Motion Simulator (VMS) facility. The results of the optimization are seen to be excellent in the vast majority of real-time frames. Deficiencies in the quality of the results in some frames are shown to be improvable with simple termination criteria adjustments, though more real-time optimization iterations would be required.
Directory of Open Access Journals (Sweden)
Xiaoya Ma
2015-11-01
Full Text Available As the main feature of land use planning, land use allocation (LUA optimization is an important means of creating a balance between the land-use supply and demand in a region and promoting the sustainable utilization of land resources. In essence, LUA optimization is a multi-objective optimization problem under the land use supply and demand constraints in a region. In order to obtain a better sustainable multi-objective LUA optimization solution, the present study proposes a LUA model based on the multi-objective artificial immune optimization algorithm (MOAIM-LUA model. The main achievements of the present study are as follows: (a the land-use supply and demand factors are analyzed and the constraint conditions of LUA optimization problems are constructed based on the analysis framework of the balance between the land use supply and demand; (b the optimization objectives of LUA optimization problems are defined and modeled using ecosystem service value theory and land rent and price theory; and (c a multi-objective optimization algorithm is designed for solving multi-objective LUA optimization problems based on the novel immune clonal algorithm (NICA. On the basis of the aforementioned achievements, MOAIM-LUA was applied to a real case study of land-use planning in Anlu County, China. Compared to the current land use situation in Anlu County, optimized LUA solutions offer improvements in the social and ecological objective areas. Compared to the existing models, such as the non-dominated sorting genetic algorithm-II, experimental results demonstrate that the model designed in the present study can obtain better non-dominated solution sets and is superior in terms of algorithm stability.
Xuan, Y.; Mahinthakumar, K.; Arumugam, S.; DeCarolis, J.
2015-12-01
Owing to the lack of a consistent approach to assimilate probabilistic forecasts for water and energy systems, utilization of climate forecasts for conjunctive management of these two systems is very limited. Prognostic management of these two systems presents a stochastic co-optimization problem that seeks to determine reservoir releases and power allocation strategies while minimizing the expected operational costs subject to probabilistic climate forecast constraints. To address these issues, we propose a high performance computing (HPC) enabled computational framework for stochastic co-optimization of water and energy resource allocations under climate uncertainty. The computational framework embodies a new paradigm shift in which attributes of climate (e.g., precipitation, temperature) and its forecasted probability distribution are employed conjointly to inform seasonal water availability and electricity demand. The HPC enabled cyberinfrastructure framework is developed to perform detailed stochastic analyses, and to better quantify and reduce the uncertainties associated with water and power systems management by utilizing improved hydro-climatic forecasts. In this presentation, our stochastic multi-objective solver extended from Optimus (Optimization Methods for Universal Simulators), is introduced. The solver uses parallel cooperative multi-swarm method to solve for efficient solution of large-scale simulation-optimization problems on parallel supercomputers. The cyberinfrastructure harnesses HPC resources to perform intensive computations using ensemble forecast models of streamflow and power demand. The stochastic multi-objective particle swarm optimizer we developed is used to co-optimize water and power system models under constraints over a large number of ensembles. The framework sheds light on the application of climate forecasts and cyber-innovation framework to improve management and promote the sustainability of water and energy systems.
Weak-quasi-bandwidth and forward-bandwidth of graphs
Institute of Scientific and Technical Information of China (English)
原晋江
1996-01-01
Concepts of weak-quasi-bandwidth and forward-bandwidth of graphs are introduced. They are used to studythe following problems in graph theory: bandwidth, topological bandwidth, fill-in, profile, path-width, tree-width.
Haidine, Abdelfatteh; Lehnert, Ralf
The planning process of the Broadband Powerline communications access networks contains two main problem parts: theGeneralized Base Station Placement (GBSP) problem and the PLC Channel Allocation Problem (P-CAP). The GBSP is investigated/solved in our previous works. In this paper, we focus on the P-CAP. The task of the P-CAP consists in allocating a sub-set of channels from an available set of PLC channels to each base station in the B-PLC site. Two optimization objectives are considered for the solution of this problem; namely the maximization of the resource reuse and the minimization of the generated interferences in the site. These objectives are conflicting, since the optimization of one of them results in the deterioration of the other. Therefore, this problem is modeled as a Multi-objective (or multi-criteria) Optimization Problem (MOP). Three variants of Pareto-based multi-objective algorithms, using evolutionary search, are used to solve it. Their performances are evaluated on four problem instances.
Directory of Open Access Journals (Sweden)
Sang-Seon Byun
2014-01-01
Full Text Available This paper considers the problem of centralized spectrum allocations in wireless sensor networks towards the following goals: (1 maximizing fairness, (2 reflecting the priority among sensor data, and (3 avoiding unnecessary spectrum handoff. We cast this problem into a multiobjective mixed integer nonconvex nonlinear programming that is definitely difficult to solve at least globally without any aid of conversion or approximation. To tackle this intractability, we first convexify the original problem using arithmetic-geometric mean approximation and logarithmic change of the decision variables and then deploy weighted Chebyshev norm-based scalarization method in order to collapse the multiobjective problem into a single objective one. Finally, we apply simple rounding method in order to obtain approximate integer solutions. The results obtained from the numerical experiments show that, by adjusting the weight on each objective function, the proposed algorithm allocates spectrum bands fairly with well observing each sensor’s priority and reduced spectrum handoffs.
Yagan, Osman; Zhang, Junshan; Cochran, Douglas
2012-01-01
We consider a cyber-physical system consisting of two interacting networks, i.e., a cyber-network overlaying a physical-network. It is envisioned that these systems are more vulnerable to attacks since node failures in one network may result in (due to the interdependence) failures in the other network, causing a cascade of failures that would potentially lead to the collapse of the entire infrastructure. The robustness of interdependent systems against this sort of catastrophic failure hinges heavily on the allocation of the (interconnecting) links that connect nodes in one network to nodes in the other network. In this paper, we characterize the optimum inter-link allocation strategy against random attacks in the case where the topology of each individual network is unknown. In particular, we analyze the "regular" allocation strategy that allots exactly the same number of bi-directional inter-network links to all nodes in the system. We show, both analytically and experimentally, that this strategy yields b...
The Optimization of Budget Outcome to Create Trust in Public Expenditure Allocation on Local Budget
Directory of Open Access Journals (Sweden)
Hendri Koeswara
2016-11-01
Full Text Available Planning and budgeting process is the most crucial process in the administration of local government. Results of previous studies in Solok, the increase in the total budget is not accompanied by spending management capabilities. Expenditure of public service has always fluctuated, but ideally should always increasing. This study aimed to analyze the outcome of the budget in the allocation of public spending in an effort to realize the presence of trust on the budget in Solok West Sumatra Province. This study uses qualitative research methods with the type of research that is selected using descriptive type. While the techniques of data collection are done through an interview, observation and documentation study. This study further highlights the emic perspective, is the voice of the informant, not the personal opinion of the researchers (etic. Then, the data analysis is done categorically and chronologically, viewed repeatedly, and will continue to be encoded. To test the verification of data, triangulation is done by comparing the results of interviews with documents obtained in the field and testing of concepts used by researchers with the information given by the informant. The results showed that the pathology was found that budget allocations reflect inefficiencies as a failure of the link between policy, planning, and budgeting as a fragmented system. But on the other hand, it must be admitted there has been “trust” among policymaking actors in allocating public expenditure budget in playing the role in the budget policy.
The evolution of optimal resource allocation and mating systems in hermaphroditic perennial plants
Wang, Ya-Qiang; Li, Yao-Tang; Wang, Rui-Wu
2016-01-01
By incorporating the effects of inbreeding depression (ID) on both juveniles and adults survivorship, we developed a new theoretical model for hermaphroditic perennial plants. Our model showed that the effect of the selfing rate on the evolutionarily stable strategy (ESS) reproductive allocation depends on three parameters: (1) the self-fertilized juvenile relative survivorship (SFJRS), (2) the self-fertilized adult relative survivorship (SFARS) and (3) the growth rate of self-fertilized adult, where the SFJRS is the survivorship of self-fertilized juveniles divided by the survivorship of outcrossed juveniles, and likewise for the SFARS. However, the ESS sex allocation decreases as the selfing rate increases. This relationship seems independent of the SFJRS, the SFARS, and the growth rate of self-fertilized adults. Additionally, our model showed that the complete outcrossing is an ESS when the fraction of juvenile inbreeding depression (FJID) is less than 1/2 − τ, where τ is the self-fertilized adults mortality rate caused by ID. In contrast, the complete selfing also acts as an ESS when the FJID is greater than 1/2 − τ. These results could explain the diversity of mating strategies and related resource allocations for plants. PMID:27681446
Optimal reliability allocation for large software projects through soft computing techniques
DEFF Research Database (Denmark)
Madsen, Henrik; Albeanu, Grigore; Albu, Razvan-Daniel
2012-01-01
or maximizing the system reliability subject to budget constraints. These kinds of optimization problems were considered both in deterministic and stochastic frameworks in literature. Recently, the intuitionistic-fuzzy optimization approach was considered as a soft computing successful modelling approach....... Firstly, a review on existing soft computing approaches to optimization is given. The main section extends the results considering self-organizing migrating algorithms for solving intuitionistic-fuzzy optimization problems attached to complex fault-tolerant software architectures which proved...
Stocker, Benjamin; Prentice, I. Colin
2016-04-01
The degree to which nitrogen availability limits the terrestrial C sink under rising CO2 is a key uncertainty in carbon cycle and climate change projections. Results from ecosystem manipulation studies and meta-analyses suggest that plant C allocation to roots adjusts dynamically under varying degrees of nitrogen availability and other soil fertility parameters. In addition, the ratio of biomass production to GPP appears to decline under nutrient scarcity. This reflects increasing plant C export into the soil and to symbionts (Cex) with decreasing nutrient availability. Cex is consumed by an array of soil organisms and may imply an improvement of nutrient availability to the plant. These concepts are left unaccounted for in Earth system models. We present a model for the coupled cycles of C and N in grassland ecosystems to explore optimal plant C allocation under rising CO2 and its implications for the ecosystem C balance. The model follows a balanced growth approach, accounting for the trade-offs between leaf versus root growth and Cex in balancing C fixation and N uptake. We further model a plant-controlled rate of biological N fixation (BNF) by assuming that Cex is consumed by N2-fixing processes if the ratio of Nup:Cex falls below the inverse of the C cost of N2-fixation. The model is applied at two temperate grassland sites (SwissFACE and BioCON), subjected to factorial treatments of elevated CO2 (FACE) and N fertilization. Preliminary simulation results indicate initially increased N limitation, evident by increased relative allocation to roots and Cex. Depending on the initial state of N availability, this implies a varying degree of aboveground growth enhancement, generally consistent with observed responses. On a longer time scale, ecosystems are progressively released from N limitation due tighter N cycling. Allowing for plant-controlled BNF implies a quicker release from N limitation and an adjustment to more open N cycling. In both cases, optimal plant
Media-specific rate allocation in heterogeneous wireless networks
Institute of Scientific and Technical Information of China (English)
JURCA Dan; FROSSARD Pascal
2006-01-01
We address the problem of joint path selection and rate allocation in multipath wireless streaming, in order to optimize a media specific quality of service. We leverage on the existence of multiple parallel wireless services, in order to enhance the received video quality at a wireless client. An optimization problem is proposed, aimed at minimizing a video distortion metric based on sequence-dependent parameters, and transmission channel characteristics, for a given wireless network infrastructure.Even if joint optimal path selection and rate allocation is in general an NP complete problem, an in-depth analysis of the media distortion evolution allows defining a low complexity optimal streaming strategy, under reasonable network assumptions. In particular, we show that a greedy allocation of rates along paths with increasing error probability leads to an optimal solution. We argue that a network path should not be chosen for transmission, unless all other available paths with lower error probability have been chosen. Moreover, the chosen paths should be used at their maximum end-to-end bandwidth. These results are demonstrated for both independent network paths, and non-disjoint channel segments, in generic network topologies. Simulation results showed that the optimal rate allocation carefully trades off total encoding/transmission rate, with the end-to-end transmission error probability and the number of chosen paths. In many cases, the optimal rate allocation provides more than 20% improvement in received video quality, compared to heuristic-based algorithms.
Directory of Open Access Journals (Sweden)
Tsai Chia-Tai
2011-01-01
Full Text Available Abstract With the rapid development of wireless communication technology and the rapid increase in demand for network bandwidth, IEEE 802.16e is an emerging network technique that has been deployed in many metropolises. In addition to the features of high data rate and large coverage, it also enables scalable video multicasting, which is a potentially promising application, over an IEEE 802.16e network. How to optimally assign the modulation and coding scheme (MCS of the scalable video stream for the mobile subscriber stations to improve spectral efficiency and maximize utility is a crucial task. We formulate this MCS assignment problem as an optimization problem, called the total utility maximization problem (TUMP. This article transforms the TUMP into a precedence constraint knapsack problem, which is a NP-complete problem. Then, a branch and bound method, which is based on two dominance rules and a lower bound, is presented to solve the TUMP. The simulation results show that the proposed branch and bound method can find the optimal solution efficiently.
Gorahava, Kaushik K; Rosenberger, Jay M; Mubayi, Anuj
2015-07-01
Visceral leishmaniasis (VL) is the most deadly form of the leishmaniasis family of diseases, which affects numerous developing countries. The Indian state of Bihar has the highest prevalence and mortality rate of VL in the world. Insecticide spraying is believed to be an effective vector control program for controlling the spread of VL in Bihar; however, it is expensive and less effective if not implemented systematically. This study develops and analyzes a novel optimization model for VL control in Bihar that identifies an optimal (best possible) allocation of chosen insecticide (dichlorodiphenyltrichloroethane [DDT] or deltamethrin) based on the sizes of human and cattle populations in the region. The model maximizes the insecticide-induced sandfly death rate in human and cattle dwellings while staying within the current state budget for VL vector control efforts. The model results suggest that deltamethrin might not be a good replacement for DDT because the insecticide-induced sandfly deaths are 3.72 times more in case of DDT even after 90 days post spray. Different insecticide allocation strategies between the two types of sites (houses and cattle sheds) are suggested based on the state VL-control budget and have a direct implication on VL elimination efforts in a resource-limited region.
DEFF Research Database (Denmark)
Zakrzewska, Anna; Ruepp, Sarah Renée; Berger, Michael Stübert
2013-01-01
The paper addresses the problem of optimal selection of Radio Access Technology (RAT) and assignment of resources in a multistandard wireless network scenario. It is shown how OPNET Modeler can be used to perform optimization studies using Integer Linear Programming (ILP) solvers. In this way...... an ongoing simulation is continuously fed with optimal assignment results. The setup allows the bounds of performance indicators to be defined and enables analysis and comparison with heuristic approaches and such results are given for the considered scenario....
Energy Technology Data Exchange (ETDEWEB)
Yamasaki, H. [Yokokawa Electric Corp., Tokyo (Japan). Research and Development Lab.
1996-08-10
Bearing reliability and safety of automatic systems in mind, man-machine roll allocation in the operation of facilities is examined, and the optimal roll allocation is proposed. The outline of the method for man-machine roll allocation is given in process instrumentation system, robotized assembly plant, railroad operation control system, and passenger airplane operation control system. The types of man-machine roll allocation in automatic system is divided into normal and emergency cases. Improvement in the total reliability of man-machine system can be expected by man-machine mutual complementary roll allocation. The core of the intelligent support system for emergency is the growing knowledge base, and the system performs intelligent support automatically or with the support of human in an emergency. For smooth man-machine information interchange at man`s own will, logical difference between man and machine must be adjusted in the man-machine interface. 8 refs., 2 tabs.
Divakar, L.; Babel, M. S.; Perret, S. R.; Gupta, A. Das
2011-04-01
SummaryThe study develops a model for optimal bulk allocations of limited available water based on an economic criterion to competing use sectors such as agriculture, domestic, industry and hydropower. The model comprises a reservoir operation module (ROM) and a water allocation module (WAM). ROM determines the amount of water available for allocation, which is used as an input to WAM with an objective function to maximize the net economic benefits of bulk allocations to different use sectors. The total net benefit functions for agriculture and hydropower sectors and the marginal net benefit from domestic and industrial sectors are established and are categorically taken as fixed in the present study. The developed model is applied to the Chao Phraya basin in Thailand. The case study results indicate that the WAM can improve net economic returns compared to the current water allocation practices.
DEFF Research Database (Denmark)
Siano, P.; Chen, Peiyuan; Chen, Zhe
2012-01-01
a hybrid optimization method that aims of maximizing the Net Present Value related to the Investment made by Wind Turbines developers in an active distribution network. The proposed network combines a Genetic Algorithm with a multi-period optimal power flow. The method, integrating active management...
DEFF Research Database (Denmark)
Siano, P.; Chen, Peiyuan; Chen, Zhe
2012-01-01
a hybrid optimization method that aims of maximizing the Net Present Value related to the Investment made by Wind Turbines developers in an active distribution network. The proposed network combines a Genetic Algorithm with a multi-period optimal power flow. The method, integrating active management...
DEFF Research Database (Denmark)
Zakrzewska, Anna; Ruepp, Sarah Renée; Berger, Michael Stübert
2013-01-01
The paper addresses the problem of optimal selection of Radio Access Technology (RAT) and assignment of resources in a multistandard wireless network scenario. It is shown how OPNET Modeler can be used to perform optimization studies using Integer Linear Programming (ILP) solvers. In this way...
Method for optimizing resource allocation in a government organization. Ph.D. Thesis
Afarin, James
1994-01-01
The managers in Federal agencies are challenged to control the extensive activities in government and still provide high-quality products and services to the American taxpayers. Considering today's complex social and economic environment and the $3.8 billion daily cost of operating the Federal Government, it is evident that there is a need to develop decision-making tools for accurate resource allocation and total quality management. The goal of this thesis is to provide a methodical process that will aid managers in Federal Government to make budgetary decisions based on the cost of services, the agency's objectives, and the customers' perception of the agency's product. A general resource allocation procedure was developed in this study that can be applied to any government organization. A government organization, hereafter the 'organization,' is assumed to be a multidivision enterprise. This procedure was applied to a small organization for the proof of the concept. This organization is the Technical Services Directorate (TSD) at the NASA Lewis Research Center in Cleveland, Ohio. As part of the procedure, a nonlinear programming model was developed to account for the resources of the organization, the outputs produced by the organization, the decision-maker's views, and the customers' satisfaction with the organization. The information on the resources of the organization was acquired from current budget levels of the organization and the human resources assigned to the divisions. The outputs of the organization were defined and measured by identifying metrics that assess the outputs, the most challenging task in this study. The decision-maker's views are represented in the model as weights assigned to the various outputs and were quantified by using the analytic hierarchy process. The customer's opinions regarding the outputs of the organization were collected through questionnaires that were designed for each division individually. Following the philosophy of
Optimal asset allocation for aggregated defined benefit pension funds with stochastic interest rates
Rincón-Zapatero, Juan Pablo; Josa-Fombellida, Ricardo
2008-01-01
In this paper we study the optimal management of an aggregated pension fund of defined benefit type, in the presence of a stochastic interest rate. We suppose that the sponsor can invest in a savings account, in a risky stock and in a bond with the aim of minimizing deviations of the unfunded actuarial liability from zero along a finite time horizon. We solve the problem by means of optimal stochastic control techniques and analyze the influence on the optimal solution of some of the paramete...
The multi-port berth allocation problem with speed optimization and emission considerations
DEFF Research Database (Denmark)
Venturini, Giada; Iris, Cagatay; Kontovas, Christos A.
2017-01-01
achieve a sustainable supply chain, and on the other side, the optimization of operations and sailing times leads to reductions in bunker consumption and, thus, to fuel cost and air emissions reductions. To that effect, there is an increasing need to address the integration opportunities and environmental...... to cover multiple ports in a shipping network under the assumption of strong cooperation between shipping lines and terminals. Speed is optimized on all sailing legs between ports, demonstrating the effect of speed optimization in reducing the total time of the operation, as well as total fuel consumption...
DEFF Research Database (Denmark)
Baldin, Andrea; Bille, Trine; Ellero, Andrea
The implementation of Revenue Management (RM) techniques in non profit performing arts organizations presents new challenges compared to other sectors, such as transportion or hospitality industries, in which these techniques are more consolidated. Indeed, performing arts organizations are charac......The implementation of Revenue Management (RM) techniques in non profit performing arts organizations presents new challenges compared to other sectors, such as transportion or hospitality industries, in which these techniques are more consolidated. Indeed, performing arts organizations...... is to incentive the customers to discriminate among themselves according to their reservation price, offering a schedule of different prices corresponding to different seats in the venue. In this context, price and allocation of the theatre seating area are decision variables that allow theatre managers to manage...... of heterogeneity among customer categories in both choice and demand. The proposed model is validated with booking data referring to the Royal Danish Theatre during the period 2010-2015....
Optimizing Manpower Allocation for Ground Handling Tasks in Airports using Column Generation
DEFF Research Database (Denmark)
Hansen, Anders Dohn; Kolind, Esben
2008-01-01
of the staff, synchronization requirements between teams, and union regulations. The problem is solved using column generation in a Branch-and-Price framework. Synchronization between teams is enforced by branching on time windows. The resource constrained shortest path subproblem is solved by a label setting......The Manpower Allocation Problem with Time Windows, Job-Teaming Constraints and a limited number of teams (m-MAPTWTC) is the problem of assigning m teams to a number of tasks, where both teams and tasks are restricted by time windows outside which operation is not possible. Tasks may require several...... individual teams to cooperate. Cooperating teams have to be synchronized with each other. Due to the limited number of teams, some tasks may have to be left unassigned. The objective is to maximize the number of assigned tasks. The problem arises in various crew scheduling contexts where cooperation between...
DEFF Research Database (Denmark)
Baldin, Andrea; Bille, Trine; Ellero, Andrea
The implementation of Revenue Management (RM) techniques in non profit performing arts organizations presents new challenges compared to other sectors, such as transportion or hospitality industries, in which these techniques are more consolidated. Indeed, performing arts organizations...... are characterized by a multi-objective function that is not solely limited to revenue. On the one hand, theatres aim to increase revenue from box office as a consequence of the systematic reduction of public funds; on the other hand they pursue the objective to increase its attendance. A common practice by theatres...... is to incentive the customers to discriminate among themselves according to their reservation price, offering a schedule of different prices corresponding to different seats in the venue. In this context, price and allocation of the theatre seating area are decision variables that allow theatre managers to manage...
A system-level bandwidth design method for wormhole network-on-chip
Wang, Jian; Li, Yubai; Liao, Changjun
2016-11-01
To improve the Network-on-Chip (NoC) performance, we propose a system-level bandwidth design method customising the bandwidths of the NoC links. In details, we first built a mathematical model to catch the relationship between the NoC commutation latency and the NoC link bandwidth, and then develop a bandwidth allocation algorithm to automatically optimise the bandwidth for each NoC link. The experimental results show that our bandwidth-customising method improves the NoC performance compared to the traditional uniform bandwidth allocation method. Besides, it can also make our NoC to achieve the same communication performance level as the uniform bandwidth NoC but using fewer bandwidth resources, which is beneficial to save the NoC area and power.
Multi- Path Routing and Resource Allocation in Active Network
Institute of Scientific and Technical Information of China (English)
XU Wu-ping; YAN Pu-liu; WU Ming
2005-01-01
An algorithm of traffic distribution called active multi-path routing (AMR) in active network is proposed.AMR adopts multi-path routing and applies nonlinear optimize approximate method to distribute network traffic amongmultiple paths. It is combined to bandwidth resource allocation and the congestion restraint mechanism to avoid congestion happening and worsen. So network performance can be improved greatly. The frame of AMR includes adaptive trafficallocation model, the conception of supply bandwidth and its'allocation model, the principle of congestion restraint and its'model, and the implement of AMR based on multi-agents system in active network. Through simulations, AMR has distinct effects on network performance. The results show AMR is a valid traffic regulation algorithm.
Directory of Open Access Journals (Sweden)
Pei-Yu Chen
2013-01-01
Full Text Available With more and more mobile device users, an increasingly important and critical issue is how to efficiently evaluate mobile network survivability. In this paper, a novel metric called Average Degree of Disconnectivity (Average DOD is proposed, in which the concept of probability is calculated by the contest success function. The DOD metric is used to evaluate the damage degree of the network, where the larger the value of the Average DOD, the more the damage degree of the network. A multiround network attack-defense scenario as a mathematical model is used to support network operators to predict all the strategies both cyber attacker and network defender would likely take. In addition, the Average DOD would be used to evaluate the damage degree of the network. In each round, the attacker could use the attack resources to launch attacks on the nodes of the target network. Meanwhile, the network defender could reallocate its existing resources to recover compromised nodes and allocate defense resources to protect the survival nodes of the network. In the approach to solving this problem, the “gradient method” and “game theory” are adopted to find the optimal resource allocation strategies for both the cyber attacker and mobile network defender.
Directory of Open Access Journals (Sweden)
Noradin Ghadimi
2012-01-01
Full Text Available The concern about the limitation of fossil fuels and also rising consciousness of environmental protection, cause the installation of DGs increase annually. This study develops an optimal placement method in order to sizing and sitting of distributed generation and capacitor banks in IEEE 33 bus test system that reconfigured. The algorithm for optimization in this paper is simulated annealing. The proposed objective function considers active power losses of the system and the voltage profile in nominal load of system. High performance of the proposed algorithm in mention system is verified by simulations in MATLAB software and in order to illustrate of feasibility of proposed method this optimization will accomplish in two cases.
DEFF Research Database (Denmark)
Kordheili, Reza Ahmadi; Pourmousavi, Ali; Pillai, Jayakrishnan Radhakrishna
2014-01-01
Tremendous penetration of renewable energy in electric networks, despite its valuable opportunities, such as balancing reserve and ancillary service, has raised concerns for network operators. Such concern stems from grid operating conditions. Such huge penetration can lead to violation in the grid...... requirements, such as voltage and current limits. This paper proposes an optimization method for determining the number of photovoltaic (PV) panels together with their arrangement in the grid in order to maximize ancillary service, without violating grid operation limits. The proposed optimization method...... the grid requirements within standard operating limits....
Alsharoa, Ahmad M.
2014-02-01
In this letter, we consider a multiple-input multiple-output two-way cognitive radio system under a spectrum sharing scenario, where primary and secondary users operate on the same frequency band. The secondary terminals aims to exchange different messages with each other using multiple relays where each relay employs an amplify-and-forward strategy. The main objective of our work is to maximize the secondary sum rate allowed to share the spectrum with the primary users by respecting a primary user tolerated interference threshold. In this context, we derive an analytical expression of the optimal power allocated to each antenna of the terminals. We then discuss the impact of some system parameters on the performance in the numerical result section. © 2012 IEEE.
Setting Optimal Bounds on Risk in Asset Allocation - a Convex Program
Directory of Open Access Journals (Sweden)
James E. Falk
2002-10-01
Full Text Available The 'Portfolio Selection Problem' is traditionally viewed as selecting a mix of investment opportunities that maximizes the expected return subject to a bound on risk. However, in reality, portfolios are made up of a few 'asset classes' that consist of similar opportunities. The asset classes are managed by individual `sub-managers', under guidelines set by an overall portfolio manager. Once a benchmark (the `strategic' allocation has been set, an overall manager may choose to allow the sub-managers some latitude in which opportunities make up the classes. He may choose some overall bound on risk (as measured by the variance and wish to set bounds that constrain the submanagers. Mathematically we show that the problem is equivalent to finding a hyper-rectangle of maximal volume within an ellipsoid. It is a convex program, albeit with potentially a large number of constraints. We suggest a cutting plane algorithm to solve the problem and include computational results on a set of randomly generated problems as well as a real-world problem taken from the literature.
OPTIMAL ALLOCATION OF LANDFILL DISPOSAL SITE: A FUZZY MULTI-CRITERIA APPROACH
Directory of Open Access Journals (Sweden)
Ajit P. Singh, A. K. Vidyarthi
2008-01-01
Full Text Available The arbitrary disposal through land-fill sites and also the unscientific management of solid wastes generated by domestic, commercial and industrial activities leading to serious problems of health, sanitation and environmental degradation in India demand an immediate proper solid waste disposal planning otherwise it may cause a serious problem, especially in small and medium-sized cities/towns if proper steps are not initiated now. The present paper aims to develop decision support systems to allocate the best landfill disposal site among the given alternative sites for Vidya Vihar, Pilani, Rajasthan, India. The technique is applied to determine the overall strategy for planning of solid waste disposal and management, while taking into account its environmental impact, as well as economical, technical and sustainable development issues. The model effectively reflects dynamic, interactive, and uncertain characteristics of the solid waste management system and provides decision-makers with a decision tool to make a better decision while choosing a municipal solid waste management strategy.
Workload-Aware and CPU Frequency Scaling for Optimal Energy Consumption in VM Allocation
Directory of Open Access Journals (Sweden)
Zhen Liu
2014-01-01
Full Text Available In the problem of VMs consolidation for cloud energy saving, different workloads will ask for different resources. Thus, considering workload characteristic, the VM placement solution will be more reasonable. In the real world, different workload works in a varied CPU utilization during its work time according to its task characteristics. That means energy consumption related to both the CPU utilization and CPU frequency. Therefore, only using the model of CPU frequency to evaluate energy consumption is insufficient. This paper theoretically verified that there will be a CPU frequency best suit for a certain CPU utilization in order to obtain the minimum energy consumption. According to this deduction, we put forward a heuristic CPU frequency scaling algorithm VP-FS (virtual machine placement with frequency scaling. In order to carry the experiments, we realized three typical greedy algorithms for VMs placement and simulate three groups of VM tasks. Our efforts show that different workloads will affect VMs allocation results. Each group of workload has its most suitable algorithm when considering the minimum used physical machines. And because of the CPU frequency scaling, VP-FS has the best results on the total energy consumption compared with the other three algorithms under any of the three groups of workloads.
DEFF Research Database (Denmark)
Zakrzewska, Anna; D’Andreagiovanni, Fabio; Ruepp, Sarah Renée
2013-01-01
We propose a novel optimization model for resource assignment in heterogeneous wireless network. The model adopts two objective functions maximizing the number of served users and the minimum granted utility at once. A distinctive feature of our new model is to consider two consecutive time slots...
Kumar, Rakesh; Chandrawat, Rajesh Kumar; Garg, B. P.; Joshi, Varun
2017-07-01
Opening the new firm or branch with desired execution is very relevant to facility location problem. Along the lines to locate the new ambulances and firehouses, the government desires to minimize average response time for emergencies from all residents of cities. So finding the best location is biggest challenge in day to day life. These type of problems were named as facility location problems. A lot of algorithms have been developed to handle these problems. In this paper, we review five algorithms that were applied to facility location problems. The significance of clustering in facility location problems is also presented. First we compare Fuzzy c-means clustering (FCM) algorithm with alternating heuristic (AH) algorithm, then with Particle Swarm Optimization (PSO) algorithms using different type of distance function. The data was clustered with the help of FCM and then we apply median model and min-max problem model on that data. After finding optimized locations using these algorithms we find the distance from optimized location point to the demanded point with different distance techniques and compare the results. At last, we design a general example to validate the feasibility of the five algorithms for facilities location optimization, and authenticate the advantages and drawbacks of them.
Optimal resource allocation and load scheduling for a multi-commodity smart energy system
Blaauwbroek, N.; Nguyen, P.H.; Shi, H.; Kamphuis, I.G.; Kling, W.L.; Konsman, M.J.
2015-01-01
The increasing introduction of district heating systems together with hybrid energy appliances as heat pumps and micro-combined heat and power installations, results in new opportunities for optimizing the available resources in multi-commodity smart energy systems, including electricity, heat and
Traffic resource allocation for complex networks
Institute of Scientific and Technical Information of China (English)
Ling Xiang; Hu Mao-Bin; Long Jian-Cheng; Ding Jian-Xun; Shi Qin
2013-01-01
In this paper,an optimal resource allocation strategy is proposed to enhance traffic dynamics in complex networks.The network resources are the total node packet-delivering capacity and the total link bandwidth.An analytical method is developed to estimate the overall network capacity by using the concept of efficient betweenness (ratio of algorithmic betweenness and local processing capacity).Three network structures (scale-free,small-world,and random networks) and two typical routing protocols (shortest path protocol and efficient routing protocol) are adopted to demonstrate the performance of the proposed strategy.Our results show that the network capacity is reversely proportional to the average path length for a particular routing protocol and the shortest path protocol can achieve the largest network capacity when the proposed resource allocation strategy is adopted.
Chemical Industry Bandwidth Study
Energy Technology Data Exchange (ETDEWEB)
none,
2006-12-01
The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.
Anderson, John B
2017-01-01
Bandwidth Efficient Coding addresses the major challenge in communication engineering today: how to communicate more bits of information in the same radio spectrum. Energy and bandwidth are needed to transmit bits, and bandwidth affects capacity the most. Methods have been developed that are ten times as energy efficient at a given bandwidth consumption as simple methods. These employ signals with very complex patterns and are called "coding" solutions. The book begins with classical theory before introducing new techniques that combine older methods of error correction coding and radio transmission in order to create narrowband methods that are as efficient in both spectrum and energy as nature allows. Other topics covered include modulation techniques such as CPM, coded QAM and pulse design.
Thompson, Jennifer A; Fielding, Katherine; Hargreaves, James; Copas, Andrew
2017-08-01
Background/Aims We sought to optimise the design of stepped wedge trials with an equal allocation of clusters to sequences and explored sample size comparisons with alternative trial designs. Methods We developed a new expression for the design effect for a stepped wedge trial, assuming that observations are equally correlated within clusters and an equal number of observations in each period between sequences switching to the intervention. We minimised the design effect with respect to (1) the fraction of observations before the first and after the final sequence switches (the periods with all clusters in the control or intervention condition, respectively) and (2) the number of sequences. We compared the design effect of this optimised stepped wedge trial to the design effects of a parallel cluster-randomised trial, a cluster-randomised trial with baseline observations, and a hybrid trial design (a mixture of cluster-randomised trial and stepped wedge trial) with the same total cluster size for all designs. Results We found that a stepped wedge trial with an equal allocation to sequences is optimised by obtaining all observations after the first sequence switches and before the final sequence switches to the intervention; this means that the first sequence remains in the control condition and the last sequence remains in the intervention condition for the duration of the trial. With this design, the optimal number of sequences is [Formula: see text], where [Formula: see text] is the cluster-mean correlation, [Formula: see text] is the intracluster correlation coefficient, and m is the total cluster size. The optimal number of sequences is small when the intracluster correlation coefficient and cluster size are small and large when the intracluster correlation coefficient or cluster size is large. A cluster-randomised trial remains more efficient than the optimised stepped wedge trial when the intracluster correlation coefficient or cluster size is small. A
Miller, Christopher J.; Goodrick, Dan
2017-01-01
The problem of control command and maneuver induced structural loads is an important aspect of any control system design. The aircraft structure and the control architecture must be designed to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to utilize high structural margins, restrict control surface commands to a limited set of analyzed combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage. An optimal control technique has been explored and shown to achieve desirable vehicle control performance while limiting sensed structural loads. The subject of this paper is the design of the optimal control architecture, and provides the reader with some techniques for tailoring the architecture, along with detailed simulation results.
A New Approach for Optimal Allocation of DG in Distribution Systems Using GA Method
Directory of Open Access Journals (Sweden)
Seyed Abbas Taher
2011-11-01
Full Text Available In placing Distributed Generation (DG sources in distribution networks, a wide range of operational and security issues needs to be considered. Many indices are employed to evaluate the optimum DG placement. Aggregation of indices to obtain a multi-objective index capable of optimizing several weighting factors is a common practice in industry. In this paper, Genetic Algorithm (GA is successfully used to identify the weighting factors in multi-objective performance index for both IEEE 33-bus and IEEE 69-bus test systems, where DG is extensively located and sized. The multi-objective performance index is computed for each configuration, yielding encouraging simulation results for application of the proposed method in power system optimal placement and sizing of DG.
Optimal Allocation of Changing Station for Electric Vehicle Based on Queuing Theory
Directory of Open Access Journals (Sweden)
Yagang Zhang
2016-11-01
Full Text Available Electric vehicle as the main development direction of the future automotive industry, has gained attention worldwide. The rationality of the planning and construction of the power station, as the foundation of energy supply, is an important premise for the development of electric vehicles. In full consideration of the electric demand and electricity consumption, this paper proposes a new construction mode in which charging station and centralized charging station are appropriately combined and presents a location optimization model. Not only can this model be applied to determine the appropriate location for the power station, but it can use the queuing theory to determine the optimal number of power equipment, with which we can achieve the minimum costs. Finally, taking a certain city as an example, the optimum plan for power station is calculated by using this model, which provides an important reference for the study of electric vehicle infrastructure planning.
Industrial Glass Bandwidth Analysis
Energy Technology Data Exchange (ETDEWEB)
Rue, David M. [Gas Technology Inst., Des Plaines, IL (United States); Servaites, James [Gas Technology Inst., Des Plaines, IL (United States); Wolf, Warren [Gas Technology Inst., Des Plaines, IL (United States)
2007-08-01
This is a study on energy use and potential savings, or "bandwidth" study, for several glassmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results.
Glass Industry Bandwidth Analysis
Energy Technology Data Exchange (ETDEWEB)
Rue, David M. [Gas Technology Inst., Des Plaines, IL (United States)
2006-07-01
This is a study on energy use and potential savings, or "bandwidth" study, for several glassmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results.
Industrial Glass Bandwidth Analysis
Energy Technology Data Exchange (ETDEWEB)
Rue, David M. [Gas Technology Inst., Des Plaines, IL (United States); Servaites, James [Gas Technology Inst., Des Plaines, IL (United States); Wolf, Warren [Gas Technology Inst., Des Plaines, IL (United States)
2007-08-01
This is a study on energy use and potential savings, or "bandwidth" study, for several glassmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results.
Glass Industry Bandwidth Analysis
Energy Technology Data Exchange (ETDEWEB)
Rue, David M. [Gas Technology Inst., Des Plaines, IL (United States)
2006-07-01
This is a study on energy use and potential savings, or "bandwidth" study, for several glassmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results.
Ayala Solares, Jose Roberto
2012-08-01
The optimal transmit power of a wireless sensor network with one transmitter and multiple receivers in a cognitive radio environment while satisfying independent peak, independent average, sum of peak and sum of average transmission rate constraints is derived. A suboptimal scheme is proposed to overcome the frequency of outages for the independent peak transmission rate constraint. In all cases, numerical results are provided for Rayleigh fading channels. © 2012 IEEE.
Optimal cost and allocation for UPFC using HRGAPSO to improve power system security and loadability
Energy Technology Data Exchange (ETDEWEB)
Marouani, I.; Guesmi, T.; Hadj Abdallah, H.; Ouali, A. [Sfax Engineering National School, Electrical Department, BP: W, 3038 Sfax (Tunisia)
2011-07-01
With the electricity market deregulation, the number of unplanned power exchanges increases. Some lines located on particular paths may become overload. It is advisable for the transmission system operator to have another way of controlling power flows in order to permit a more efficient and secure use of transmission lines. The FACTS devices (Flexible AC Transmission Systems) could be a mean to carry out this function. In this paper, unified power flow controller (UPFC) is located in order to maximize the system loadability and index security. The optimization problem is solved using a new evolutionary learning algorithm based on a hybrid of real genetic algorithm (RGA) and particle swarm optimization (PSO) called HRGAPSO. The Newton-Raphson load flow algorithm is modified to consider the insertion of the UPFC devices in the network. Simulations results validate the efficiency of this approach to improvement in security, reduction in losses of power system, minimizing the installation cost of UPFC and increasing power transfer capability of the existing power transmission lines. The optimization results was performed on 14-bus test system and implemented using MATLAB.
Optimal Multi-Server Allocation to Parallel Queues With Independent Random Queue-Server Connectivity
Al-Zubaidy, Hussein; Viniotis, Yannis
2011-01-01
We investigate an optimal scheduling problem in a discrete-time system of L parallel queues that are served by K identical, randomly connected servers. Each queue may be connected to a subset of the K servers during any given time slot. This model has been widely used in studies of emerging 3G/4G wireless systems. We introduce the class of Most Balancing (MB) policies and provide their mathematical characterization. We prove that MB policies are optimal; we de?ne optimality as minimization, in stochastic ordering sense, of a range of cost functions of the queue lengths, including the process of total number of packets in the system. We use stochastic coupling arguments for our proof. We introduce the Least Connected Server First/Longest Connected Queue (LCSF/LCQ) policy as an easy-to-implement approximation of MB policies. We conduct a simulation study to compare the performance of several policies. The simulation results show that: (a) in all cases, LCSF/LCQ approximations to the MB policies outperform the o...
Optimal cost and allocation for UPFC using HRGAPSO to improve power system security and loadability
Directory of Open Access Journals (Sweden)
Marouani I., Guesmi T., Hadj Abdallah H., Ouali A.
2011-09-01
Full Text Available With the electricity market deregulation, the number of unplanned power exchanges increases. Some lines located on particular paths may become overload. It is advisable for the transmission system operator to have another way of controlling power flows in order to permit a more efficient and secure use of transmission lines. The FACTS devices (Flexible AC Transmission Systems could be a mean to carry out this function. In this paper, unified power flow controller (UPFC is located in order to maximize the system loadability and index security. The optimization problem is solved using a new evolutionary learning algorithm based on a hybrid of real genetic algorithm (RGA and particle swarm optimization (PSO called HRGAPSO. The Newton-Raphson load flow algorithm is modified to consider the insertion of the UPFC devices in the network. Simulations results validate the efficiency of this approach to improvement in security, reduction in losses of power system, minimizing the installation cost of UPFC and increasing power transfer capability of the existing power transmission lines. The optimization results was performed on 14-bus test system and implemented using MATLAB.
Self-organized Balanced Resources in Random Networks with Transportation Bandwidths
Yeung, Chi Ho; Wong, K. Y. Michael
We apply statistical physics to study the task of resource allocation in random networks with limited bandwidths for the transportation of resources along the links. We derive algorithms which searches the optimal solution without the need of a global optimizer. For networks with uniformly high connectivity, the resource shortage of a node becomes a well-defined function of its capacity. An efficient profile of the allocated resources is found, with clusters of node interconnected by an extensive fraction of unsaturated links, enabling the resource shortages among the nodes to remain balanced. The capacity-shortage relation exhibits features similar to the Maxwell’s construction. For scale-free networks, such an efficient profile is observed even for nodes of low connectivity.
Bandwidth and Noise in Spatiotemporally Modulated Mueller Matrix Polarimeters
Vaughn, Israel Jacob
Polarimetric systems design has seen recent utilization of linear systems theory for system descriptions. Although noise optimal systems have been shown, bandwidth performance has not been addressed in depth generally and is particularly lacking for Mueller matrix (active) polarimetric systems. Bandwidth must be considered in a systematic way for remote sensing polarimetric systems design. The systematic approach facilitates both understanding of fundamental constraints and design of higher bandwidth polarimetric systems. Fundamental bandwidth constraints result in production of polarimetric "artifacts" due to channel crosstalk upon Mueller matrix reconstruction. This dissertation analyzes bandwidth trade-offs in spatio-temporal channeled Mueller matrix polarimetric systems. Bandwidth is directly related to the geometric positioning of channels in the Fourier (channel) space, however channel positioning for polarimetric systems is constrained both physically and by design parameters like domain separability. We present the physical channel constraints and the constraints imposed when the carriers are separable between space and time. Polarimetric systems are also constrained by noise performance, and there is a trade-off between noise performance and bandwidth. I develop cost functions which account for the trade-off between noise and bandwidth for spatio-temporal polarimetric systems. The cost functions allow a systems designer to jointly optimize systems with good bandwidth and noise performance. Optimization is implemented for a candidate spatio-temporal system design, and high temporal bandwidth systems resulting from the optimization are presented. Systematic errors which impact the bandwidth performance and mitigation strategies for these systematic errors are also presented. Finally, a portable imaging Mueller matrix system is built and analyzed based on the theoretical bandwidth analysis and system bandwidth optimization. Temporal bandwidth performance is
Optimal Tax-Timing and Asset Allocation when Tax Rebates on Capital Losses are Limited
DEFF Research Database (Denmark)
Marekwica, Marcel
2012-01-01
This article studies the portfolio problem with realization-based capital gain taxation when limited amounts of losses qualify for tax rebate payments, as is the case under current US tax law. When the tax rate applicable to realized losses exceeds that on realized capital gains, it can be optimal...... to realize capital gains immediately and pay capital gain taxes to regain the option to use potential future losses against a higher tax rate. This incentive adds an entirely new and as yet unstudied dimension to the portfolio problem. It causes risk averse investors to hold more equity and attain higher...
Directory of Open Access Journals (Sweden)
Haijing Tang
2013-01-01
Full Text Available Clustering has become a common trend in very long instruction words (VLIW architecture to solve the problem of area, energy consumption, and design complexity. Register-file-connected clustered (RFCC VLIW architecture uses the mechanism of global register file to accomplish the inter-cluster data communications, thus eliminating the performance and energy consumption penalty caused by explicit inter-cluster data move operations in traditional bus-connected clustered (BCC VLIW architecture. However, the limit number of access ports to the global register file has become an issue which must be well addressed; otherwise the performance and energy consumption would be harmed. In this paper, we presented compiler optimization techniques for an RFCC VLIW architecture called Lily, which is designed for encryption systems. These techniques aim at optimizing performance and energy consumption for Lily architecture, through appropriate manipulation of the code generation process to maintain a better management of the accesses to the global register file. All the techniques have been implemented and evaluated. The result shows that our techniques can significantly reduce the penalty of performance and energy consumption due to access port limitation of global register file.
Institute of Scientific and Technical Information of China (English)
Mena Rodrigo; Zio Enrico; Kristjanpoller Fredy; Arata Adolfo
2013-01-01
We present a novel system productivity simulation and optimization modeling framework in which equipment availability is a variable in the expected productivity function of the system.The framework is used for allocating trucks by route according to their operating performances in a truck-shovel system of an open-pit mine,so as to maximize the overall productivity of the fleet.We implement the framework in an originally designed and specifically developed simulator-optimizer software tool.We make an application on a real open-pit mine case study taking into account the stochasticity of the equipment behavior and environment.The total system production values obtained with and without considering the equipment reliability,availability and maintainability (RAM) characteristics are compared.We show that by taking into account the truck and shovel RAM aspects,we can maximize the total production of the system and obtain specific information on the production availability and productivity of its components.
Directory of Open Access Journals (Sweden)
Kai Kang
2017-01-01
Full Text Available Recycling waste products is an environmental-friendly activity that can result in manufacturing cost saving and economic efficiency improving. In the beer industry, recycling bottles can reduce manufacturing cost and the industry’s carbon footprint. This paper presents a model for a collection-distribution center location and allocation problem in a closed-loop supply chain for the beer industry under a fuzzy random environment, in which the objectives are to minimize total costs and transportation pollution. Both random and fuzzy uncertainties, for which return rate and disposal rate are considered fuzzy random variables, are jointly handled in this paper to ensure a more practical problem solution. A heuristic algorithm based on priority-based global-local-neighbor particle swarm optimization (pb-glnPSO is applied to ensure reliable solutions for this NP-hard problem. A beer company case study is given to illustrate the application of the proposed model and to demonstrate the priority-based global-local-neighbor particle swarm optimization.
Analysis of Optimal Allocation of Health Resources%卫生资源配置优化浅析
Institute of Scientific and Technical Information of China (English)
王永波; 孙景泰
2012-01-01
The optimal allocation of health resources is the demand for fully satisfying our country's increasingly expanded and abundant medical treatment, is the important work of tallying with medical health reform and development, is the good guarantee to create harmonious society and increase public health level of body and mind. This paper carried out discussion on how to optimize configuration of health resources in China, and the existent problems in practice management, which has important practical significance for creating the health resources service system of tallying with national conditions, improving health service development level and creating significant benefits.%优化配置卫生资源是充分满足我国日益扩充、丰富的医疗救治需求,契合医疗卫生改革发展的重要工作,是创建和谐社会、提升大众身心健康水平的良好保证.因此本文就我国卫生资源如何优化配置,实践管理中包含的问题展开探讨,对创建契合国情的卫生资源服务体系,提升医疗卫生服务发展水平,创设显著效益有重要的实践意义.
Institute of Scientific and Technical Information of China (English)
TIAN Yi-mei; CHI Hai-yan; LI Hong; SHAN Jin-lin; ZHAI Chun-nian
2005-01-01
The concentration of Residual Chlorine (RC) frequently violates the standard in situations of urban water distribution system with large water supply area and long time of distribution.If chlorine dosage increases within water treatment plant, although RC in distribution system could meet water quality standard, Disinfection By-Products (DBPs) such as hydrocarbon halide rises.In the paper, a mathematical model of chlorine allocation optimization was presented based on reaction kinetics mechanism and optimization theory to solve the problem.The model includes the objective function of minimizing annual operation cost and constraints of RC standard and rational chlorination station distribution, and solving by 0-1 Integer Programming (IP).The model had been applied to a real water distribution system.The simulation results of the model showed that adding chlorine in water distribution system remarkably improved water quality and reduced the operation cost by 49.3% per year less than chlorine dosed only in water treatment plant to meet RC standard.The results prove adding chlorine in water distribution system based on the model can bring both technological and economic advancement.
Directory of Open Access Journals (Sweden)
Hao Xu
2013-02-01
Full Text Available In this paper, novel enhanced Cognitive Radio Network (CRN is considered by using power controlwhere secondary users (SUs are allowed to use wireless resources of the primary users (PUs when PUsare deactivated, but also allow SUs to coexist with PUs while PUs are activated by managinginterference caused from SUs to PUs. Therefore, a novel finite horizon adaptive optimal distributedpower allocation (FH-AODPA scheme is proposed by incorporating the effect of channel uncertaintiesfor enhanced CRN in the presence of wireless channel uncertainties under two cases. In Case 1,proposed scheme can force the Signal-to-interference (SIRof the SUs to converge to a higher targetvalue for increasing network throughput when PU’s are not communicating within finite horizon. OncePUs are activated as in the Case 2, proposed scheme cannot only force the SIR’s of PUs to converge to ahigher target SIR, but also force the SIR’s of SUs to converge to a lower value for regulating theirinterference to Pus during finite time period. In order to mitigate the attenuation of SIR’s due to channeluncertainties the proposed novel FH-AODPA allows the SIR’s of both PUs’ and SUs’ to converge to adesired target SIR while minimizing the energy consumption within finite horizon. Simulation resultsillustrate that this novel FH-AODPA scheme can converge much faster and cost less energy than othersby adapting to the channel variations optimally.
Directory of Open Access Journals (Sweden)
Yong Li
2012-05-01
Full Text Available Wind power parallel operation is an effective way to realize the large scale use of wind power, but the fluctuations of power output from wind power units may have great influence on power quality, hence a new method of power smoothing and capacity optimized allocation based on hybrid energy storage technology is proposed in terms of the uncontrollable and unexpected characteristics of wind speed in wind farms. First, power smoothing based on a traditional Inertial Filter is introduced and the relationship between the time constant, its smoothing effect and capacity allocation are analyzed and combined with Proportional Integral Differential (PID control to realize power smoothing control of wind power. Then wavelet theory is adopted to realize a multi-layer decomposition of power output in some wind farms, a power smoothing model based on hybrid energy storage technology is constructed combining the characteristics of the Super Capacitor (SC and Battery Energy Storage System (BESS technologies. The hybrid energy storage system is available for power fluctuations with high frequency-low energy and low frequency-high energy to achieve good smoothing effects compared with a single energy storage system. The power fluctuations filtered by the Wavelet Transform is regarded as the target value of BESS, the charging and discharging control for battery is completed quickly by Model Algorithm Control (MAC. Because of the influence of the inertia and the response speed of the battery, its actual output is not completely equal to the target value which mainly reflects in high-frequency part, the difference part uses SC to compensate and makes the output of battery and SC closer to the target value on the whole. Compared with the traditional Inertial Filter and PID control method, the validity of the model was verified by simulation results. Finally under the premise of power grid standards, the corresponding capacity design had been given to reduce the
Holmes, Morgan; Bodie, Kelly; Porter, Geoffrey; Sullivan, Victoria; Tarasuk, Joy; Trembley, Jodie; Trudeau, Maureen
2010-01-01
Optimizing human and physical resources is a major concern for cancer care decision-makers and practitioners. This issue is particularly acute in the context of ambulatory out patient chemotherapy clinics, especially when - as is the case almost everywhere in the industrialized world - the number of people requiring systemic therapy is increasing while budgets, staffing and physical space remain static. Recent initiatives at three hospital-based chemotherapy units - in Halifax, Toronto and Kingston - shed light on the value of process analysis and reorganization for using existing human and physical resources to their full potential, improving patient flow and enhancing patient satisfaction. The steps taken in these settings are broadly applicable to other healthcare settings and would likely result in similar benefits in those environments.
Institute of Scientific and Technical Information of China (English)
Aijun Liu; Michele Pfund; John Fowler
2016-01-01
How to deal with the colaboration between task decomposition and task scheduling is the key problem of the integrated manufacturing system for complex products. With the development of manufacturing technology, we can probe a new way to solve this problem. Firstly, a new method for task granularity quantitative analysis is put forward, which can precisely evaluate the task granularity of complex product cooperation workflow in the integrated manufacturing system, on the above basis; this method is used to guide the coarse-grained task decomposition and recombine the sub-tasks with low cohesion coefficient. Then, a multi-objective optimieation model and an algorithm are set up for the scheduling optimization of task scheduling. Finaly, the appli-cation feasibility of the model and algorithm is ultimately vali-dated through an application case study.
Bandwidth Reconfigurable Metamaterial Arrays
Directory of Open Access Journals (Sweden)
Nathanael J. Smith
2014-01-01
Full Text Available Metamaterial structures provide innovative ways to manipulate electromagnetic wave responses to realize new applications. This paper presents a conformal wideband metamaterial array that achieves as much as 10 : 1 continuous bandwidth. This was done by using interelement coupling to concurrently achieve significant wave slow-down and cancel the inductance stemming from the ground plane. The corresponding equivalent circuit of the resulting array is the same as that of classic metamaterial structures. In this paper, we present a wideband Marchand-type balun with validation measurements demonstrating the metamaterial (MTM array’s bandwidth from 280 MHz to 2800 MHz. Bandwidth reconfiguration of this class of array is then demonstrated achieving a variety of band-pass or band-rejection responses within its original bandwidth. In contrast with previous bandwidth and frequency response reconfigurations, our approach does not change the aperture’s or ground plane’s geometry, nor does it introduce external filtering structures. Instead, the new responses are realized by making simple circuit changes into the balanced feed integrated with the wideband MTM array. A variety of circuit changes can be employed using MEMS switches or variable lumped loads within the feed and 5 example band-pass and band-rejection responses are presented. These demonstrate the potential of the MTM array’s reconfiguration to address a variety of responses.
Miller, Christopher J.; Goodrick, Dan
2017-01-01
The problem of control command and maneuver induced structural loads is an important aspect of any control system design. The aircraft structure and the control architecture must be designed to achieve desired piloted control responses while limiting the imparted structural loads. The classical approach is to utilize high structural margins, restrict control surface commands to a limited set of analyzed combinations, and train pilots to follow procedural maneuvering limitations. With recent advances in structural sensing and the continued desire to improve safety and vehicle fuel efficiency, it is both possible and desirable to develop control architectures that enable lighter vehicle weights while maintaining and improving protection against structural damage. An optimal control technique has been explored and shown to achieve desirable vehicle control performance while limiting sensed structural loads to specified values. This technique has been implemented and flown on the National Aeronautics and Space Administration Full-scale Advanced Systems Testbed aircraft. The flight tests illustrate that the approach achieves the desired performance and show promising potential benefits. The flights also uncovered some important issues that will need to be addressed for production application.
Directory of Open Access Journals (Sweden)
Maryam Nikouei Mehr
2017-01-01
Full Text Available Consider the problem faced by a purchaser of solid waste management services, who needs to identify waste collection points, the assignment of waste generation points to waste collection points, and the type and number of receptacles utilized at each collection point. Receptacles whose collection schedule is specified in advance are charged a fixed fee according to the number of times the receptacle is serviced (emptied per week. For other receptacles, the purchaser pays a fee comprised of a fixed service charge, plus a variable cost that is assessed on a per-ton-removed basis. We develop a mathematical programming model to minimize the costs that the purchaser pays to the waste management provider, subject to a level of service that is sufficient to collect all of the purchaser’s required waste. Examining historical data from the University of Missouri, we observed significant variability in the amount of waste serviced for nonscheduled receptacles. Because this variability has a significant impact on cost, we modified our model using robust optimization techniques to address the observed uncertainty. Our model’s highly robust solution, while slightly more expensive than the nonrobust solution in the most-optimistic scenario, significantly outperforms the nonrobust solution for all other potential scenarios.
Optimal Bi-Objective Redundancy Allocation for Systems Reliability and Risk Management.
Govindan, Kannan; Jafarian, Ahmad; Azbari, Mostafa E; Choi, Tsan-Ming
2016-08-01
In the big data era, systems reliability is critical to effective systems risk management. In this paper, a novel multiobjective approach, with hybridization of a known algorithm called NSGA-II and an adaptive population-based simulated annealing (APBSA) method is developed to solve the systems reliability optimization problems. In the first step, to create a good algorithm, we use a coevolutionary strategy. Since the proposed algorithm is very sensitive to parameter values, the response surface method is employed to estimate the appropriate parameters of the algorithm. Moreover, to examine the performance of our proposed approach, several test problems are generated, and the proposed hybrid algorithm and other commonly known approaches (i.e., MOGA, NRGA, and NSGA-II) are compared with respect to four performance measures: 1) mean ideal distance; 2) diversification metric; 3) percentage of domination; and 4) data envelopment analysis. The computational studies have shown that the proposed algorithm is an effective approach for systems reliability and risk management.
Optimal crop selection and water allocation under limited water supply in irrigation
Stange, Peter; Grießbach, Ulrike; Schütze, Niels
2015-04-01
Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with limited water resources in irrigation systems, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand at the same time. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from optimized agronomic response on farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF). These functions take into account different soil types, crops and stochastically generated climate scenarios. The SCWPF's are used to compute the water demand considering different conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed which helps to evaluate combined water supply and demand management policies.
Directory of Open Access Journals (Sweden)
Leppänen V
2009-01-01
Full Text Available Abstract Consider a processor organization consisting of a number of client modules and server modules (jointly called devices, like memory units and arithmetic-logic processing units. Suppose that these devices are interconnected with a bus which is segmented in such a way that devices connected to a particular segment can communicate in parallel to the data transfer operations going on in the other segments. This is achieved by a control logic which is able to reserve a continuous subsequence of the segments necessary to establish a path from the source to the target device. Given the frequency of data transfer operations between the devices, our task is to determine an efficient segmentation and segment-to-device assignment of this on-chip architecture. This task is formulated as an optimization problem which considers the amount of data transfer operations performed via the bus segments. The problem turns out to be NP hard but we propose efficient local search-based heuristics for it. The heuristics are applied to sample cases, and the outcome is an improved performance in terms of a shorter execution time.
Directory of Open Access Journals (Sweden)
T. Seceleanu
2009-01-01
Full Text Available Consider a processor organization consisting of a number of client modules and server modules (jointly called devices, like memory units and arithmetic-logic processing units. Suppose that these devices are interconnected with a bus which is segmented in such a way that devices connected to a particular segment can communicate in parallel to the data transfer operations going on in the other segments. This is achieved by a control logic which is able to reserve a continuous subsequence of the segments necessary to establish a path from the source to the target device. Given the frequency of data transfer operations between the devices, our task is to determine an efficient segmentation and segment-to-device assignment of this on-chip architecture. This task is formulated as an optimization problem which considers the amount of data transfer operations performed via the bus segments. The problem turns out to be NP hard but we propose efficient local search-based heuristics for it. The heuristics are applied to sample cases, and the outcome is an improved performance in terms of a shorter execution time.
Institute of Scientific and Technical Information of China (English)
刘中金; 卓子寒; 何跃鹰; 李勇; 苏厉; 金德鹏; 曾烈光
2016-01-01
Network virtualization is widely deployed in network experiment platforms and data center networks. As a key networking equipment in virtualized environment, the virtual router can build many virtual router instances to run different virtual networks. The key problem for a virtual router lies in how to schedule the packets into different virtual instances according to the virtual networks’ bandwidth requirement. In this article, a model is given to the scheduling problem and a dynamical weighted scheduling algorithm is proposed. The experimental results show that the proposed algorithm has superiority over miDRR algorithm in terms of the efficiency and the fairness.%网络虚拟化被广泛用于网络实验平台和数据中心等场景中。作为虚拟化网络中的核心组网设备，虚拟路由器可以在同一物理底层上构建多个虚拟路由器实例来承载多个虚拟网。其核心调度问题在于如何根据不同虚拟网对带宽的不同需求，将网络数据包调度到不同的实例中。该文针对该问题对虚拟化场景下的队列调度问题进行建模，提出了基于动态配额的队列调度算法，与miDRR等算法相比，该文算法在虚拟网带宽分配的有效性和公平性上有明显优势。
Energy Technology Data Exchange (ETDEWEB)
Donnelly, Patrick Joseph; McIver, Lauren; Gaines, Brian R.; Anderson, Erik; Collins, Michael Joseph; Thomas,Kurt Adam; McDaniel, Austin
2007-09-01
Remotely-fielded unattended sensor networks generally must operate at very low power--in the milliwatt or microwatt range--and thus have extremely limited communications bandwidth. Such sensors might be asleep most of the time to conserve power, waking only occasionally to transmit a few bits. RFID tags for tracking or material control have similarly tight bandwidth constraints, and emerging nanotechnology devices will be even more limited. Since transmitted data is subject to spoofing, and since sensors might be located in uncontrolled environments vulnerable to physical tampering, the high-consequence data generated by such systems must be protected by cryptographically sound authentication mechanisms; but such mechanisms are often lacking in current sensor networks. One reason for this undesirable situation is that standard authentication methods become impractical or impossible when bandwidth is severely constrained; if messages are small, a standard digital signature or HMAC will be many times larger than the message itself, yet it might be possible to spare only a few extra bits per message for security. Furthermore, the authentication tags themselves are only one part of cryptographic overhead, as key management functions (distributing, changing, and revoking keys) consume still more bandwidth. To address this problem, we have developed algorithms that provide secure authentication while adding very little communication overhead. Such techniques will make it possible to add strong cryptographic guarantees of data integrity to a much wider range of systems.
Energy Technology Data Exchange (ETDEWEB)
Donnelly, Patrick Joseph; McIver, Lauren; Gaines, Brian R.; Anderson, Erik; Collins, Michael Joseph; Thomas,Kurt Adam; McDaniel, Austin
2007-09-01
Remotely-fielded unattended sensor networks generally must operate at very low power--in the milliwatt or microwatt range--and thus have extremely limited communications bandwidth. Such sensors might be asleep most of the time to conserve power, waking only occasionally to transmit a few bits. RFID tags for tracking or material control have similarly tight bandwidth constraints, and emerging nanotechnology devices will be even more limited. Since transmitted data is subject to spoofing, and since sensors might be located in uncontrolled environments vulnerable to physical tampering, the high-consequence data generated by such systems must be protected by cryptographically sound authentication mechanisms; but such mechanisms are often lacking in current sensor networks. One reason for this undesirable situation is that standard authentication methods become impractical or impossible when bandwidth is severely constrained; if messages are small, a standard digital signature or HMAC will be many times larger than the message itself, yet it might be possible to spare only a few extra bits per message for security. Furthermore, the authentication tags themselves are only one part of cryptographic overhead, as key management functions (distributing, changing, and revoking keys) consume still more bandwidth. To address this problem, we have developed algorithms that provide secure authentication while adding very little communication overhead. Such techniques will make it possible to add strong cryptographic guarantees of data integrity to a much wider range of systems.
Bandwidth in bolometric interferometry
Charlassier, R.; Bunn, E. F.; Hamilton, J.-Ch.; Kaplan, J.; Malu, S.
2010-05-01
Context. Bolometric interferometry is a promising new technology with potential applications to the detection of B-mode polarization fluctuations of the cosmic microwave background (CMB). A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers to be competitive with imaging experiments. A crucial concern is that interferometers are assumed to be significantly affected by a spoiling effect known as bandwidth smearing. Aims: We investigate how the bandwidth modifies the work principle of a bolometric interferometer and affects its sensitivity to the CMB angular power spectra. Methods: We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. If the phase shifters produce shifts that are constant with respect to frequency, the instrument works like its monochromatic version (the modulation matrix is not modified), while if they vary (linearly or otherwise) with respect to frequency, one has to perform a special reconstruction scheme, which allows the visibilities to be reconstructed in frequency subbands. Using an angular power spectrum estimator that accounts for the bandwidth, we finally calculate the sensitivity of a broadband bolometric interferometer. A numerical simulation is performed that confirms the analytical results. Results: We conclude that (i) broadband bolometric interferometers allow broadband visibilities to be reconstructed regardless of the type of phase shifters used and (ii) for dedicated B-mode bolometric interferometers, the sensitivity loss caused by bandwidth smearing is quite acceptable, even for wideband instruments (a factor of 2 loss for a typical 20% bandwidth experiment).
Energy efficiency in elastic-bandwidth optical networks
DEFF Research Database (Denmark)
Vizcaino, Jorge Lopez; Ye, Yabin; Tafur Monroy, Idelfonso
2011-01-01
The forecasted growth in the Internet traffic has made the operators and industry to be concerned about the power consumption of the networks, and to become interested in alternatives to plan and operate the networks in a more energy efficient manner. The introduction of OFDM, and its property...... of elastic bandwidth allocation, opens new horizons in the operation of optical networks. In this paper, we compare the network planning problem in an elastic bandwidth CO-OFDM-based network and a fixed-grid WDM network. We highlight the benefits that bandwidth elasticity and the selection of different...
Brochero, D.; Anctil, F.; Gagné, C.
2012-04-01
Today, the availability of the Meteorological Ensemble Prediction Systems (MEPS) and its subsequent coupling with multiple hydrological models offer the possibility of building Hydrological Ensemble Prediction Systems (HEPS) consisting of a large number of members. However, this task is complex both in terms of the coupling of information and of the computational time, which may create an operational barrier. The evaluation of the prominence of each hydrological members can be seen as a non-parametric post-processing stage that seeks finding the optimal participation of the hydrological models (in a fashion similar to the Bayesian model averaging technique), maintaining or improving the quality of a probabilistic forecasts based on only x members drawn from a super ensemble of d members, thus allowing the reduction of the task required to issue the probabilistic forecast. The main objective of the current work consists in assessing the degree of simplification (reduction of the number of hydrological members) that can be achieved with a HEPS configured using 16 lumped hydrological models driven by the 50 weather ensemble forecasts from the European Centre for Medium-range Weather Forecasts (ECMWF), i.e. an 800-member HEPS. In a previous work (Brochero et al., 2011a, b), we demonstrated that the proportion of members allocated to each hydrological model is a sufficient criterion to reduce the number of hydrological members while improving the balance of the scores, taking into account interchangeability of the ECMWF MEPS. Here, we compare the proportion of members allocated to each hydrological model derived from three non-parametric techniques: correlation analysis of hydrological members, Backward Greedy Selection (BGS) and Nondominated Sorting Genetic Algorithm (NSGA II). The last two techniques allude to techniques developed in machine learning, in a multicriteria framework exploiting the relationship between bias, reliability, and the number of members of the
浅谈商业银行人力资源的优化配置%Discussion on the optimal allocation of human resources in commercial banks
Institute of Scientific and Technical Information of China (English)
麦嘉华
2016-01-01
通过分析商业银行人力资源配置存在的问题，提出了优化商业银行人力资源配置的目标体系、建立人力资源配置的调整机制、优化人力资源内部管理结构、调整人力资源的优化配置、优化人力资源的组合配置方式和完善人力资源配置的保障体系等优化人力资源配置的措施和建议。%By analyzing the existing problems in human resource allocation of commercial banks, this paper puts forward the measures of optimizing objective system of human resources allocation of commercial banks, establishing adjustment mechanism, optimizing internal management structure of human resources, optimizing human resources allocation, optimizing combination configuration mode of human resources and improving security system of human resources.
分布式MIMO系统最优功率分配容量分析%Capacity Analysis of Optimal Power Allocation in Distributed MIMO Systems
Institute of Scientific and Technical Information of China (English)
王树坤; 高向川; 王忠勇; 路新华; 董素鸽
2015-01-01
大规模分布式MIMO( Distributed Multiple-Input Multiple-Output,D-MIMO)系统的性能不仅受到小尺度瑞利衰落的影响,而且还受到路径损耗的影响,系统的容量分析存在一定的困难。目前容量分析多以天线等功率分配为主。基于信道统计信息,结合线性排列天线的结构特点,针对大规模分布式MIMO功率优化后的容量性能进行分析,提出一种最优功率分配方案。与传统的等功率分配方案相比,最优功率分配方案可以使分布式MIMO系统的容量获得较大提升。%The performance of D-MIMO ( Massive Distribute Multiple-Input Multiple-Output) systems is affected not only by small-scale Rayleigh fading but also by path loss. There exist certain difficulties in an-alyzing the capacity of Massive D-MIMO systems. At present, plenty of system capacity analysis focuses on equal power allocation of each transmission antenna. Based on CSI (Channel Statistics Information), the structure of linear antennas, and the capacity analysis of the system with optimal power allocation, an optimal power allocation scheme is proposed. Comparison with the traditional equal power allocation indi-cates that the optimal power allocation scheme could evidently increase the capacity of D-MIMO system.
Bandwidth in bolometric interferometry
Charlassier, R; Hamilton, J -Ch; Kaplan, J; Malu, S
2009-01-01
Bolometric Interferometry is a technology currently under development that will be first dedicated to the detection of B-mode polarization fluctuations in the Cosmic Microwave Background. A bolometric interferometer will have to take advantage of the wide spectral detection band of its bolometers in order to be competitive with imaging experiments. A crucial concern is that interferometers are presumed to be importantly affected by a spoiling effect known as bandwidth smearing. In this paper, we investigate how the bandwidth modifies the work principle of a bolometric interferometer and how it affects its sensitivity to the CMB angular power spectra. We obtain analytical expressions for the broadband visibilities measured by broadband heterodyne and bolometric interferometers. We investigate how the visibilities must be reconstructed in a broadband bolometric interferometer and show that this critically depends on hardware properties of the modulation phase shifters. Using an angular power spectrum estimator ...
Bandwidth Trading as Incentive
Eger, Kolja; Killat, Ulrich
In P2P networks with multi-source download the file of interest is fragmented into pieces and peers exchange pieces with each other although they did not finish the download of the complete file. Peers can adopt different strategies to trade upload for download bandwidth. These trading schemes should give peers an incentive to contribute bandwidth to the P2P network. This chapter studies different trading schemes analytically and by simulations. A mathematical framework for bandwidth trading is introduced and two distributed algorithms, which are denoted as Resource Pricing and Reciprocal Rate Control, are derived. The algorithms are compared to the tit-for-tat principle in BitTorrent. Nash Equilibria and results from simulations of static and dynamic networks are presented. Additionally, we discuss how trading schemes can be combined with a piece selection algorithm to increase the availability of a full copy of the file. The chapter closes with an extension of the mathematical model which takes also the underlying IP network into account. This results in a TCP variant optimised for P2P content distribution.
Distributed Storage Allocation Problems
Leong, Derek; Dimakis, Alexandros G.; Ho, Tracey
2009-01-01
We investigate the problem of using several storage nodes to store a data object, subject to an aggregate storage budget or redundancy constraint. It is challenging to find the optimal allocation that maximizes the probability of successful recovery by the data collector because of the large space of possible symmetric and nonsymmetric allocations, and the nonconvexity of the problem. For the special case of probability-l recovery, we show that the optimal allocatio...
Mehrotra, Sanjay; Kim, Kibaek
2011-12-01
We consider the problem of outcomes based budget allocations to chronic disease prevention programs across the United States (US) to achieve greater geographical healthcare equity. We use Diabetes Prevention and Control Programs (DPCP) by the Center for Disease Control and Prevention (CDC) as an example. We present a multi-criteria robust weighted sum model for such multi-criteria decision making in a group decision setting. The principal component analysis and an inverse linear programming techniques are presented and used to study the actual 2009 budget allocation by CDC. Our results show that the CDC budget allocation process for the DPCPs is not likely model based. In our empirical study, the relative weights for different prevalence and comorbidity factors and the corresponding budgets obtained under different weight regions are discussed. Parametric analysis suggests that money should be allocated to states to promote diabetes education and to increase patient-healthcare provider interactions to reduce disparity across the US.
Institute of Scientific and Technical Information of China (English)
Su Yang; Xu Zhanqi; Zhao Ruiqin; Liu Zengji
2008-01-01
A layered network model for optical transport networks is proposed in this paper, which involves Internet Protocol (IP), Synchronous Digital Hierarchy (SDH) and Wavelength Division Multiplexing (WDM) layers. The strategy of Dynamic Joint Routing and Resource Allocation (DJRRA) and its algorithm description are also presented for the proposed layered network model. DJRRA optimizes the bandwidth usage of interface links between different layers and the logic links inside all layers. The simulation results show that DJRRA can reduce the blocking probability and increase network throughput effectively, which is in contrast to the classical separate sequential routing and resource allocation solutions.
Optimal Allocation of Public Sports Resources Viewed from Law%法学视域下体育公共资源的优化配置
Institute of Scientific and Technical Information of China (English)
张涛
2012-01-01
Based on the explanation of public resources and public sports resources,the paper represents the legal value orientation and controling principles of optimal allocation of public sports resources.The paper proposes the countermeasures for the optimal allocation of the public sports resources,such as prefecting the government licensed management system,standardizing the administrative charging,promoting the public sports financial system reform and improving the decision mechanism of the citizens participating in the optimal allocation of public sports resources%在对公共资源与体育公共资源进行释义的基础上,阐述了体育公共资源优化配置的法律价值取向和法律控制原则,并提出法律视域下体育公共资源优化配置的对策：完善政府特许经营制度;规范行政收费行为;推进体育公共财政体制改革;健全与完善公民参与体育公共资源优化配置的决策机制。
DEFF Research Database (Denmark)
Sugimoto, Y; Watanabe, Y; Ikeda, N
2006-01-01
Numerical and experimental studies on the photonic crystal waveguide intersection based on the topology optimization design method are reported and the effectiveness is shown by achieving high transmission spectra with low crosstalk for the straightforward beam-propagation line....
Institute of Scientific and Technical Information of China (English)
殷德聪; 许跃进; 吴昊; 杨建
2012-01-01
It is very important to select distribution transformer capacity for power grid. It can optimize the allocation of transformer capacity and enhance the economical efficiency of distribution power grid. Using the idea of economic current density during the choice of wire, a new approach was proposed based on optimum allocated load rate to select distribution transformer capacity. First, a model of transformer capacity optimum allocation was established by using the new method, it not only contained investment, operation and maintenance fees and lost expenses, but also included the economic losses caused by transformer outage. Then, each cost model was constructed scientifically. All these were to achieve the target of minimum annual integrated cost. After optimization and calculation, recommended values of optimum allocated load rate for selecting one, two and three distribution transformers were obtained. Using the recommended values to select distribution transformer capacity is simple and feasible, economical and reasonable. Also, a technical support is provided for selecting distribution transformer capacity in power grid construction.%为实现配电变压器容量的最佳配置以及配电网的经济运行,配电变压器的容量选择研究具有重要意义.该文借鉴选择导线时经济电流密度的思想,提出了基于最佳配置负载率的配电变压器容量优化配置方法.利用该方法对变压器容量的优化配置进行建模,并以年综合费用最小为目标,模型中不仅考虑投资、运行维护费和损耗费用,还计入了变压器停运造成的经济损失.经优化计算,得出选择1台、2台及3台配电变压器时的最佳配置负载率推荐值.利用此推荐值选择配电变压器容量简便可行、可为电网建设中配电变压器容量的选择提供技术支持.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
This paper presents a detail analysis of two bandwidth packing algorithms, used for processing connection requests in the centralized wireless network. Each call comes with a specific bandwidth request. A request can be satisfied only if there is sufficient bandwidth available during resource scheduling and allocation. Unsatisfied requests were held in a queue. The metric of bandwidth utilization ratio was used to quantify the performance of our algorithms. By theoretical analysis, our algorithms can improve the average bandwidth usage ratio significantly,about 8%～ 10% without adding much computation complexity. Moreover, our algorithms outperform next fit with fragmentation (NFF) algorithm when the bandwidth resource is scarce. In this paper, the contributions follows: Introducing bandwidth packing problem into wireless network; Proposing two new bandwidth packing algorithms for wireless network where the complicate scheduling algorithms are prohibited; Studying the average performance of our algorithms mathematically, which agree well with the simulation results.
Improvement of CBQ for bandwidth reclamation of RPR
Huang, Benxiong; Wang, Xiaoling; Xu, Ming; Shi, Lili
2004-04-01
The Resilient Packet Ring (RPR) IEEE 802.17 standard is under development as a new high-speed backbone technology for metropolitan area networks (MAN) [1]. Bandwidth reclamation has been concerned in RPR specifications from draft 0.1 to draft 2.4. According to specifications, allocated bandwidth can be reused, or reclaimed, by a lower priority service class whenever the reclamation does not effect the service guarantees of any equal or higher priority classes on the local station or on any other station on the ring [2]. The class-based queuing (CBQ) algorithm is proposed to implement link-sharing [3]. A hierarchical link-sharing structure can be used to specify guidelines for the distribution of 'excess" bandwidth [4] and it can rate-limit all classes to their allocated bandwidth. There is some sameness between the link-sharing of CBQ and bandwidth reclamation of RPR. The CBQ is a mature technology while RPR is a new technology. Given CBQ improvement and full use so as to make its thought suitable for bandwidth reclamation of RPR is the focus of our work. In this paper, we present the solution that can solve the reclamation problem, which proves to be effective by simulation.
基于效用函数的CGF协同任务分配优化研究%Utility Based Task Allocation Optimized for CGF Collaboration
Institute of Scientific and Technical Information of China (English)
宦婧; 周伟祝; 李季颖; 侯立平
2012-01-01
Aiming at the question of optimizing CGF colaboration, in order to avoid only part optimized in allocation scheme and consume long time using bidding results, first, utility function mathematical model based on CGFs ability vector and the ability vector foundation of mission requirement are constructed, Second, using the suiting function with maximized overall utility, then apply inheritance algorithm to overall optimization for the tender matrix of CGF based on favoritism, the simulation indicates the CGF colaboration allocation model can realize that CGF colaboration control and decision-making optimized, and the application of inheritance algorithm can convergent to overall optimization very fast. At last, this method solve effectively in task allocation of colaboration antisubmarine submarine searching is indicated.%针对CGF协同控制优化问题,为解决仅凭招投标结果确定任务分配方案时只能获得局部最优且耗时较长的问题,首先构建了CGF能力向量和子任务要求的能力向量.在此基础上建立了效用函数数学模型.然后以全局效用最大为适应度函数,以反潜直升机协同搜素为背景.应用遗传算法对基于CGF偏好的投标矩阵进行任务分配全局优化.仿真验证表明,所建协同任务分配模型能够实现CGF协同决策优化.而且遗传算法能够很快收敛到全局最优解,有效地解决了舰空协同反潜中对潜搜索的协同任务分配问题.
Ezenwaji, Emma E.; Anyadike, Raymond N. C.; Igu, Nnaemeka I.
2014-03-01
Recent studies in water supply in Enugu urban area have observed that there is a persistent water supply shortage relative to demand. One of the strategies for achieving a good water supply under the circumstance is through efficient water allocation to consumers. The existing allocation system by the Enugu State Water Corporation is not achieving the desired goal, because it is not based on any scientific criteria. In this study, we have employed the linear programming modelling technique to optimise the allocation of 35,000,000 L of water produced daily by the State Water Corporation and supplied to the four sectors of the town. The result shows that the model allocated 27,470,000 L to the residential sector, 3,360,000 L to commercial, 3,120,000 L to industrial and 882,000 L to public institutions sectors leaving a balance of 168,000 L to be utilised in emergency situations. This allocation pattern departs sharply from the present management technique adopted by the corporation. It is then suggested that for urban water supply to be sustainable in the town, the corporation should rely on this technique for water supply.
Decomposition method for zonal resource allocation problems in telecommunication networks
Konnov, I. V.; Kashuba, A. Yu
2016-11-01
We consider problems of optimal resource allocation in telecommunication networks. We first give an optimization formulation for the case where the network manager aims to distribute some homogeneous resource (bandwidth) among users of one region with quadratic charge and fee functions and present simple and efficient solution methods. Next, we consider a more general problem for a provider of a wireless communication network divided into zones (clusters) with common capacity constraints. We obtain a convex quadratic optimization problem involving capacity and balance constraints. By using the dual Lagrangian method with respect to the capacity constraint, we suggest to reduce the initial problem to a single-dimensional optimization problem, but calculation of the cost function value leads to independent solution of zonal problems, which coincide with the above single region problem. Some results of computational experiments confirm the applicability of the new methods.
Amiri, Maghsoud; Khajeh, Mostafa
2016-11-01
Bi-objective optimization of the availability allocation problem in a series-parallel system with repairable components is aimed in this paper. The two objectives of the problem are the availability of the system and the total cost of the system. Regarding the previous studies in series-parallel systems, the main contribution of this study is to expand the redundancy allocation problems to systems that have repairable components. Therefore, the considered systems in this paper are the systems that have repairable components in their configurations and subsystems. Due to the complexity of the model, a meta-heuristic method called as non-dominated sorting genetic algorithm is applied to find Pareto front. After finding the Pareto front, a procedure is used to select the best solution from the Pareto front.
[Estimation of rice LAI by using NDVI at different spectral bandwidths].
Wang, Fu-min; Huang, Jing-feng; Tang, Yan-lin; Wang, Xiu-zhen
2007-11-01
The canopy hyperspectral reflectance data of rice at its different development stages were collected from field measurement, and the corresponding NDVIs as well as the correlation coefficients of NDVIs and LAI were computed at extending bandwidth of TM red and near-infrared (NIR) spectra. According to the variation characteristics of best fitted R2 with spectral bandwidth, the optimal bandwidth was determined. The results showed that the correlation coefficients of LAI and ND-VI and the maximum R2 of the best fitted functions at different spectral bandwidths had the same variation trend, i.e., decreased with increasing bandwidth when the bandwidth was less than 60 nm. However, when the bandwidth was beyond 60 nm, the maximum R2 somewhat fluctuated due to the effect of NIR. The analysis of R2 variation with bandwidth indicated that 15 nm was the optimal bandwidth for the estimation of rice LAI by using NDVI.
Joint Uplink Resource Allocation Algorithm with Proportional-Fair in Heterogeneous Wireless Networks
Directory of Open Access Journals (Sweden)
Juan Fan
2013-10-01
Full Text Available In this paper, we exploit the uplink radio resource allocation considering proportional fairness among users in heterogeneous wireless networks. Meanwhile, multi-mode user terminals are assumed to have the capability of using multiple radio access technologies simultaneously. To this end, a joint optimization problem is formulated for power and bandwidth allocation for uplink transmission. Since the formulated primal problem is difficult to solve directly, we make continuous relaxation and obtain a near-optimal solution using Karush-Kuhn-Tucker conditions, and then propose a joint resource allocation algorithm. Simulation results show the proposed algorithm work, and the algorithm provides superior system throughput and much better fairness among users comparing to a heuristic algorithm
2014-01-22
mental /behavioral health , and prescriptions. TRICARE Prime enrollees are guaranteed access within time limits. Drive time to the primary care site...efficiency: concept, measurement techniques and review of hospital efficiency studies. Malaysian Journal of Public Health Medicine, 10(2), 35-43...for Resource Allocation Decision Making in the Military Health System Bastian, Nathaniel D. Center for Integrated Healthcare Delivery Systems
Ultrahigh bandwidth signal processing
DEFF Research Database (Denmark)
Oxenløwe, Leif Katsuo
2016-01-01
Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, an hence useful for all types of data signals including coherent multi......-level modulation founats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signa In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral...... regeneratio These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platform like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described....
Frequency allocations for a new satellite service - Digital audio broadcasting
Reinhart, Edward E.
1992-03-01
The allocation in the range 500-3000 MHz for digital audio broadcasting (DAB) is described in terms of key issues such as the transmission-system architectures. Attention is given to the optimal amount of spectrum for allocation and the technological considerations relevant to downlink bands for satellite and terrestrial transmissions. Proposals for DAB allocations are compared, and reference is made to factors impinging on the provision of ground/satellite feeder links. The allocation proposals describe the implementation of 50-60-MHz bandwidths for broadcasting in the ranges near 800 MHz, below 1525 MHz, near 2350 MHz, and near 2600 MHz. Three specific proposals are examined in terms of characteristics such as service areas, coverage/beam, channels/satellite beam, and FCC license status. Several existing problems are identified including existing services crowded with systems, the need for new bands in the 1000-3000-MHz range, and variations in the nature and intensity of implementations of existing allocations that vary from country to country.
Directory of Open Access Journals (Sweden)
Hamed Piarehzadeh
2012-08-01
Full Text Available In this study is tried to optimal distributed generation allocation for stability improvement in radial distribution systems. Voltage instability implies an uncontrolled decrease in voltage triggered by a disturbance, leading to voltage collapse and is primarily caused by dynamics connected with the load. The instability is divided into steady state and transient voltage instability Based on the time spectrum of the incident of the phenomena. The analysis is accomplished using a steady state voltage stability index which can be evaluated at each node of the distribution system. Several optimal capacities and locations are used to check these results. The location of DG has the main effect voltage stability on the system. Effects of location and capacity on incrementing steady state voltage stability in radial distribution systems are examined through Harmony Search Algorithm (HSA and finally the results are compared to Particle Swarm Optimization (PSO on the terms of speed, convergence and accuracy.
Energy Technology Data Exchange (ETDEWEB)
Aime, M.
2003-11-15
Thanks to the technological progress achieved in the field of power electronics, the use of static converters has spread to new applications. In particular, some applications such as active filtering or the supply of special AC machines require power converters having good dynamic performances. The subject of this thesis is to evaluate systematically the dynamic performances of multi-cell converters, and then to optimize these performances. This document is organized in four chapters. The first one summarizes the main multilevel converter structures, and some control strategies dedicated to these structures. The second chapter presents the evaluation criteria chosen to quantify the dynamic performances of static converters. These criteria are then used to compare the performances obtained with two different PWM strategies. An optimized strategy which results from a trade-off between the two former strategies is then introduced. The third chapter shows a new control strategy of multi-cell voltage source converters. This new strategy enables to control the peak current at a fixed switching frequency. The operation of this controller is explained, and the results obtained by digital simulations are presented and discussed. The fourth chapter deals with the experimental achievement of the peak current control. In particular, the implementation of the control algorithm within a FPGA is demonstrated. Finally, the conclusion of this thesis presents some orientations for further developments, in order to improve the current control strategy and to widen its field of applications. (author)
Directory of Open Access Journals (Sweden)
Feilong Tang
2010-01-01
Full Text Available Mobile and wireless networks are the integrant infrastructure of mobile and pervasive computing that aims at providing transparent and preferred information and services for people anytime anywhere. In such environments, end-to-end network bandwidth is crucial to improve user's transparent experience when providing on-demand services such as mobile video playing. As a result, powerful computing power is required for networked nodes, especially for routers. General-purpose processors cannot meet such requirements due to their limited processing ability, and poor programmability and scalability. Intel's network processor IXP is specially designed for fast packet processing to achieve a broad bandwidth. IXP provides a large number of registers to reduce the number of memory accesses. Registers in an IXP are physically partitioned as two banks so that two source operands in an instruction have to come from the two banks respectively, which makes the IXP register allocation tricky and different from conventional ones. In this paper, we investigate an approach for efficiently generating balanced bipartite graph and register allocation algorithms for the dual-bank register allocation in IXPs. The paper presents a graph uniform 2-way partition algorithm (FPT, which provides an optimal solution to the graph partition, and a heuristic algorithm for generating balanced bipartite graph. Finally, we design a framework for IXP register allocation. Experimental results demonstrate the framework and the algorithms are efficient in register allocation for IXP network processors.
Dynamic Subcarrier Allocation for Real-Time Traffic over Multiuser OFDM Systems
Directory of Open Access Journals (Sweden)
Li VictorOK
2009-01-01
Full Text Available A dynamic resource allocation algorithm to satisfy the packet delay requirements for real-time services, while maximizing the system capacity in multiuser orthogonal frequency division multiplexing (OFDM systems is introduced. Our proposed cross-layer algorithm, called Dynamic Subcarrier Allocation algorithm for Real-time Traffic (DSA-RT, consists of two interactive components. In the medium access control (MAC layer, the users' expected transmission rates in terms of the number of subcarriers per symbol and their corresponding transmission priorities are evaluated. With the above MAC-layer information and the detected subcarriers' channel gains, in the physical (PHY layer, a modified Kuhn-Munkres algorithm is developed to minimize the system power for a certain subcarrier allocation, then a PHY-layer resource allocation scheme is proposed to optimally allocate the subcarriers under the system signal-to-noise ratio (SNR and power constraints. In a system where the number of mobile users changes dynamically, our developed MAC-layer access control and removal schemes can guarantee the quality of service (QoS of the existing users in the system and fully utilize the bandwidth resource. The numerical results show that DSA-RT significantly improves the system performance in terms of the bandwidth efficiency and delay performance for real-time services.
Institute of Scientific and Technical Information of China (English)
王一杰; 赵舫; 丁颖; 李丰伟; 蔡振华
2011-01-01
为有效寻找电网无功补偿配置的薄弱点,提出了一种新的无功补偿设备优化配置的方法.该方法根据110 kV变电站全年的无功负荷情况统计出无功负荷概率分布曲线,采用最优覆盖法建立无功补偿配置优化模型,并通过全局搜索寻求优化配置方案.通过对优化配置方案与实际补偿容量配置的比较,给出了无功补偿配置相对薄弱的变电站,为电力系统规划人员提供决策依据.%To find the weak points of power system reactive power compensation allocation, this paper presents an optimized configuration of the method, which gathers reactive power loads of 110 kV substation throughout the year to get the optimal probability curve, adopts optimal cover method to establish the optimized configuration model, and uses global search to find the optimal solution. Through the comparison between the optimized configuation scheme and the actual compensation capacity, this paper presents the substation with insufficient reactive power compensation allocation, which supplies effective recommendations for the power system planners.
Digital demodulator for wide bandwidth SAR
DEFF Research Database (Denmark)
Jørgensen, Jørn Hjelm
2000-01-01
A novel approach to the design of efficient digital quadrature demodulators for wide bandwidth SAR systems is described. Efficiency is obtained by setting the intermediate frequency to 1/4 the ADC sampling frequency. One channel is made filter-free by synchronizing the local oscillator...... with the output decimator. The filter required by the other channel is optimized through global search using the system level performance metrics integrated sidelobe level ratio (ISLR) and peak sidelobe level ratio (PSLR)....
Terêncio, D. P. S.; Sanches Fernandes, L. F.; Cortes, R. M. V.; Pacheco, F. A. L.
2017-07-01
This study introduces an improved rainwater harvesting (RWH) suitability model to help the implementation of agro-forestry projects (irrigation, wildfire combat) in catchments. The model combines a planning workflow to define suitability of catchments based on physical, socio-economic and ecologic variables, with an allocation workflow to constrain suitable RWH sites as function of project specific features (e.g., distance from rainfall collection to application area). The planning workflow comprises a Multi Criteria Analysis (MCA) implemented on a Geographic Information System (GIS), whereas the allocation workflow is based on a multiple-parameter ranking analysis. When compared to other similar models, improvement comes with the flexible weights of MCA and the entire allocation workflow. The method is tested in a contaminated watershed (the Ave River basin) located in Portugal. The pilot project encompasses the irrigation of a 400 ha crop land that consumes 2.69 Mm3 of water per year. The application of harvested water in the irrigation replaces the use of stream water with excessive anthropogenic nutrients that may raise nitrosamines in the food and accumulation in the food chain, with severe consequences to human health (cancer). The selected rainfall collection catchment is capable to harvest 12 Mm3·yr-1 (≈ 4.5 × the requirement) and is roughly 3 km far from the application area assuring crop irrigation by gravity flow with modest transport costs. The RWH system is an 8-meter high that can be built in earth with reduced costs.
Ultrahigh bandwidth signal processing
Oxenløwe, Leif Katsuo
2016-04-01
Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, and hence useful for all types of data signals including coherent multi-level modulation formats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signals. In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral magnification of the OFDM signal. Utilising such telescopic arrangements, it has become possible to perform a number of interesting functionalities, which will be described in the presentation. This includes conversion from OFDM to Nyquist WDM, compression of WDM channels to a single Nyquist channel and WDM regeneration. These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platforms like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described.
Error-resilient video communications over CDMA networks with a bandwidth constraint.
Shen, Yushi; Cosman, Pamela C; Milstein, Laurence B
2006-11-01
We present an adaptive video transmission scheme for use in a code-division multiple-access network, which incorporates efficient bandwidth allocation among source coding, channel coding, and spreading under a fixed total bandwidth constraint. We derive the statistics of the received signal, as well as a theoretical bound on the packet drop rate at the receiver. Based on these results, a bandwidth allocation algorithm is proposed at the packet level, which incorporates the effects of both the changing channel conditions and the dynamics of the source content. Detailed simulations are done to evaluate the performance of the system, and the sensitivity of the system to estimation error is presented.
Theoretical Calculation of MMF's Bandwidth
Institute of Scientific and Technical Information of China (English)
LI Xiao-fu; JIANG De-sheng; YU Hai-hu
2004-01-01
The difference between over-filled launch bandwidth (OFL BW) and restricted mode launch bandwidth (RML BW) is described. A theoretical model is founded to calculate the OFL BW of grade index multimode fiber (GI-MMF),and the result is useful to guide the modification of the manufacturing method.
Estimating Bottleneck Bandwidth using TCP
Allman, Mark
1998-01-01
Various issues associated with estimating bottleneck bandwidth using TCP are presented in viewgraph form. Specific topics include: 1) Why TCP is wanted to estimate the bottleneck bandwidth; 2) Setting ssthresh to an appropriate value to reduce loss; 3) Possible packet-pair solutions; and 4) Preliminary results: ACTS and the Internet.
Bandwidth of Gaussian weighted Chirp
DEFF Research Database (Denmark)
Wilhjelm, Jens E.
1993-01-01
Four major time duration and bandwidth expressions are calculated for a linearly frequency modulated sinusoid with Gaussian shaped envelope. This includes a Gaussian tone pulse. The bandwidth is found to be a nonlinear function of nominal time duration and nominal frequency excursion of the chirp...
Improved-Bandwidth Transimpedance Amplifier
Chapsky, Jacob
2009-01-01
The widest available operational amplifier, with the best voltage and current noise characteristics, is considered for transimpedance amplifier (TIA) applications where wide bandwidth is required to handle fast rising input signals (as for time-of-flight measurement cases). The added amplifier inside the TIA feedback loop can be configured to have slightly lower voltage gain than the bandwidth reduction factor.
Programmable bandwidth management in software-defined EPON architecture
Li, Chengjun; Guo, Wei; Wang, Wei; Hu, Weisheng; Xia, Ming
2016-07-01
This paper proposes a software-defined EPON architecture which replaces the hardware-implemented DBA module with reprogrammable DBA module. The DBA module allows pluggable bandwidth allocation algorithms among multiple ONUs adaptive to traffic profiles and network states. We also introduce a bandwidth management scheme executed at the controller to manage the customized DBA algorithms for all date queues of ONUs. Our performance investigation verifies the effectiveness of this new EPON architecture, and numerical results show that software-defined EPONs can achieve less traffic delay and provide better support to service differentiation in comparison with traditional EPONs.
GAMS在灌区水资源优化分配中的应用%The Application of GAMS Software in Water Resource Optimal Allocation
Institute of Scientific and Technical Information of China (English)
布海力切木·阿布都热哈克尔; 吾买尔·吐尔逊
2013-01-01
水资源的短缺是全球性问题,水资源优化分配是重要的农业节水措施,是目前农业节水研究的重大课题之一.当水资源优化分配中未知量较多时,传统的手工计算方法已不能满足需要,必须用计算机模型来计算.GAMS是国外应用较广的计算机语言,能通过很简单的计算程序迅速求解线性规划、非线性规划、整数规划问题.通过GAMS语言,建立了简单的灌区水资源分配模型,求解了不同水库泄水条件下的各用户最优水量分配方式.%Water resource scarcity is a global issue.Water resource optimal allocation is one of the agricultural water saving measurement,is the important topic of the current irrigation water resource saving research.It is extremely hard or even impossible to calculate the optimal water allocation by hand when the problem includes many variables,so computer modeling is the only way to solve the problem.The GAMS is a very popular model at aboard,and suits for solving the linear,non-linear,and integer problems.Through a simple water allocation issue to introduce the GAMS model and its main characteristics,and don' t modifying the entire model but only changing the amount of water released from reservoir to calculate the net benefit response to the different reservoir release.
Zafar, Ammar
2013-12-01
This paper investigates the energy-efficiency enhancement of a variable-gain dual-hop amplify-and-forward (AF) relay network utilizing selective relaying. The objective is to minimize the total consumed power while keeping the end-to-end signal-to-noise-ratio (SNR) above a certain peak value and satisfying the peak power constraints at the source and relay nodes. To achieve this objective, an optimal relay selection and power allocation strategy is derived by solving the power minimization problem. Numerical results show that the derived optimal strategy enhances the energy-efficiency as compared to a benchmark scheme in which both the source and the selected relay transmit at peak power. © 2013 IEEE.
赋权控制分配策略的空间优化设计%The Design of Space Optimization for Weighted Control Allocation Scheme
Institute of Scientific and Technical Information of China (English)
陈勇; 董新民; 王发威; 赵丽
2012-01-01
To increase the using rate of attainable virtual instruction set in static weighted control allocation, a design scheme of space optimization for determining the best weights of instructions offline is proposed based on the improved particle swarm optimization. The mathematical models of weighted pseudo-inverse and mixed optimization methods are built respectively whose uniform control law is deducted and attainable set constructing algorithm is presented. By introducing the quantum and genetic factors, the diversity of particle swarm is enhanced through cross operation to obtain the global optimal weights of control instructions quickly. The simulation results show that the designed scheme can achieve the maximal attainable set space of weighted control allocation.%为提高静态赋权控制分配策略虚拟指令可达集的使用率,基于改进粒子群算法提出了一种离线确定控制指令最优化权值的空间优化设计方案.分别建立了加权伪逆法和混合优化法的数学模型,推导出统一的控制律形式,并给出了构造可达集空间的算法:引入量子和遗传因了,通过粒子的交叉操作增强粒子群的多样性,以快速求解控制指令权值的全局最优点.仿真结果表明,设计的方案可以实现赋权控制分配策略可达集空间的最大化.
Channel Resource Allocation for VoIP Applications in Collaborative IEEE 802.11/802.16 Networks
Directory of Open Access Journals (Sweden)
Foh ChuanHeng
2010-01-01
Full Text Available Collaborations between the IEEE 802.11 and the IEEE 802.16 networks operating in a common spectrum offers dynamic allocate bandwidth resources to achieve improved performance for network applications. This paper studies the bandwidth resource allocation of collaborative IEEE 802.11 and IEEE 802.16 networks. Consider delivering data packets between mobile stations and Internet users through an access point (AP of the IEEE 802.11 network and a base station (BS of the IEEE 802.16 network operating on a common frequency band, we analyze their medium access control (MAC protocols, frame structures, and design a cooperation mechanism for the IEEE 802.11 and the IEEE 802.16 networks to share the same medium with adaptive resource allocation. Based on the mechanism, an optimized resource allocation scheme is proposed for VoIP applications. An analytical model is developed for the study to show significant improvements in voice capacity for our optimized resource allocation scheme.
Spectrum Assignment with Non-Deterministic Bandwidth of Spectrum Holein Cognitive Radio Networks
Directory of Open Access Journals (Sweden)
Huang Jie
2016-01-01
Full Text Available The spectrum allocation for cognitive radio networks (CRNs has received considerable studies under the assumption that the bandwidth of spectrum holes is static. However, in practice, the bandwidth of spectrum holes is time-varied due to primary user/secondary user (PU/SU activity and mobility, which result in non-determinacy. This paper studies the spectrum allocation for CRNs with non-deterministic bandwidth of spectrum holes. We present a novel probability density function (PDF model through order statistic to describe the non-deterministic bandwidth of spectrum holes and provide a bound to approximate it. After that, a statistical spectrum allocation model based on stochastic multiple knapsack problem (MKP is established for spectrum allocation with non-deterministic bandwidth of spectrum holes. To reduce the computational complexity, we transform this stochastic programming probleminto a constant MKP though exploiting the properties of cumulative distribution function (CDF, which can be solved via MTHG algorithm by using auxiliary variable. Simulation results illustrate that the proposed statistical spectrum allocation algorithm can achieve better performances compared to the existing algorithms when the bandwidth of spectrum holes istime-varied.
Agent based Bandwidth Reservation Routing Technique in Mobile Ad Hoc Networks
Directory of Open Access Journals (Sweden)
Vishnu Kumar Sharma,
2011-12-01
Full Text Available In mobile ad hoc networks (MANETs, inefficient resource allocation causes heavy losses to the service providers and results in inadequate user proficiency. For improving and automating the quality of service of MANETs, efficient resource allocation techniques are required. In this paper, we propose an agent based bandwidth reservation technique for MANET. The mobile agent from the source starts forwarding the data packets through the path which has minimum cost, congestion and bandwidth. The status of every node is collected which includes the bottleneck bandwidth field and the intermediate node computes the available bandwidth on the link. At the destination, after updating the new bottleneck bandwidth field, the data packet is feedback to the source. In resource reservation technique, if the available bandwidth is greater than bottleneck bandwidth, then bandwidth reservation for the flow is done. Using rate monitoring and adjustment methodologies, rate control is performed for the congested flows. By simulation results, we show that the resource allocation technique reduces the losses and improves the network performance.
Adaptive Resource Allocation and Internet Traffic Engineering on Data Network
Directory of Open Access Journals (Sweden)
Hatim Hussein
2015-02-01
Full Text Available This research paper describes the issues of bandwid th allocation, optimum capacity allocation, network operational cost reduction, and improve Int ernet user experience. Traffic engineering (TE is used to manipulate network traffic to achie ve certain requirements and meets certain needs. TE becomes one of the most important buildin g blocks in the design of the Internet backbone infrastructure. Research objective: effici ent allocation of bandwidth across multiple paths. Optimum path selection. Minimize network tra ffic delays and maximize bandwidth utilization over multiple network paths. The bandwi dth allocation is performed proportionally over multiple paths based on the path capacity.
Upgrade trigger: Bandwidth strategy proposal
Fitzpatrick, Conor; Meloni, Simone; Boettcher, Thomas Julian; Whitehead, Mark Peter; Dziurda, Agnieszka; Vesterinen, Mika Anton
2017-01-01
This document describes a selection strategy for the upgrade trigger using charm signals as a benchmark. The Upgrade trigger uses a 'Run 2-like' sequence consisting of a first and second stage, in between which the calibration and alignment is performed. The first stage, HLT1, uses an inclusive strategy to select beauty and charm decays, while the second stage uses offline-quality exclusive selections. A novel genetic algorithm-based bandwidth division is performed at the second stage to distribute the output bandwidth among different physics channels, maximising the efficiency for useful physics events. The performance is then studied as a function of the available output bandwidth.
Directory of Open Access Journals (Sweden)
Bingkui Qiu
2015-04-01
Full Text Available In this study, an inexact stochastic fuzzy programming (ISFP model is proposed for land-use allocation (LUA and environmental/ecological planning at a watershed level, where uncertainties associated with land-use parameters, benefit functions, and environmental/ecological requirements are described as discrete intervals, probabilities and fuzzy sets. In this model, an interval stochastic fuzzy programming model is used to support quantitative optimization under uncertainty. Complexities in land-use planning systems can be systematically reflected, thus applicability of the modeling process can be highly enhanced. The proposed method is applied to planning land use/ecological balance in Poyang Lake watershed, China. The objective of the ISFP is maximizing net benefit from the LUA system and the constraints including economic constraints, social constraints, land suitability constraints, environmental constraints, ecological constraints and technical constraints. Modeling results indicate that the desired system benefit will be between [15.17, 18.29] × 1012 yuan under the minimum violating probabilities; the optimized areas of commercial land, industrial land, agricultural land, transportation land, residential land, water land, green land, landfill land and unused land will be optimized cultivated land, forest land, grass land, water land, urban land, unused land and landfill will be [228234, 237844] ha, [47228, 58451] ha, [20982, 23718] ha, [33897, 35280] ha, [15215, 15907] ha, [528, 879] ha and [1023, 1260] ha. These data can be used for generating decision alternatives under different scenarios and thus help decision makers identify desired policies under various system-reliability constraints of ecological requirement and environmental capacity. Tradeoffs between system benefits and constraint-violation risks can be tackled. They are helpful for supporting (a decision of land-use allocation and government investment; (b formulation of local
Department of Housing and Urban Development — This report displays the Emergency Solutions Grants (ESG), formerly Emergency Shelter Grants, allocation by jurisdiction. The website allows users to look at...
Directory of Open Access Journals (Sweden)
A. Elmitwally
2015-12-01
Full Text Available This paper addresses the problem of overcurrent relays (OCRs coordination in the presence of DGs. OCRs are optimally set to work in a coordinated manner to isolate faults with minimal impacts on customers. The penetration of DGs into the power system changes the fault current levels seen by the OCRs. This can deteriorate the coordinated operation of OCRs. Operation time difference between backup and main relays can be below the standard limit or even the backup OCR can incorrectly work before the main OCR. Though resetting of OCRs is tedious especially in large systems, it cannot alone restore the original coordinated operation in the presence of DGs. The paper investigates the optimal utilization of fault current limiters (FCLs to maintain the directional OCRs coordinated operation without any need to OCRs resetting irrespective of DGs status. It is required to maintain the OCRs coordination at minimum cost of prospective FCLs. Hence, the FCLs location and sizing problem is formulated as a constrained multi-objective optimization problem. Multi-objective particle swarm optimization is adopted for solving the optimization problem to determine the optimal locations and sizes of FCLs. The proposed algorithm is applied to meshed and radial power systems at different DGs arrangements using different types of FCLs. Moreover, the OCRs coordination problem is studied when the system includes both directional and non-directional OCRs. Comparative analysis of results is provided.
Nord, Eric A.; Shea, Katriona; Lynch, Jonathan P.
2011-01-01
Background and Aims Timing of reproduction is a key life-history trait that is regulated by resource availability. Delayed reproduction in soils with low phosphorus availability is common among annuals, in contrast to the accelerated reproduction typical of other low-nutrient environments. It is hypothesized that this anomalous response arises from the high marginal value of additional allocation to root growth caused by the low mobility of phosphorus in soils. Methods To better understand the benefits and costs of such delayed reproduction, a two-resource dynamic allocation model of plant growth and reproduction is presented. The model incorporates growth, respiration, and carbon and phosphorus acquisition of both root and shoot tissue, and considers the reallocation of resources from senescent leaves. The model is parameterized with data from Arabidopsis and the optimal reproductive phenology is explored in a range of environments. Key Results The model predicts delayed reproduction in low-phosphorus environments. Reproductive timing in low-phosphorus environments is quite sensitive to phosphorus mobility, but is less sensitive to the temporal distribution of mortality risks. In low-phosphorus environments, the relative metabolic cost of roots was greater, and reproductive allocation reduced, compared with high-phosphorus conditions. The model suggests that delayed reproduction in response to low phosphorus availability may be reduced in plants adapted to environments where phosphorus mobility is greater. Conclusions Delayed reproduction in low-phosphorus soils can be a beneficial response allowing for increased acquisition and utilization of phosphorus. This finding has implications both for efforts to breed crops for low-phosphorus soils, and for efforts to understand how climate change may impact plant growth and productivity in low-phosphorus environments. PMID:21712299
Bandwidth sharing networks with multiscale traffic
Directory of Open Access Journals (Sweden)
Mathieu Feuillet
2015-03-01
Full Text Available In multi-class communication networks, traffic surges due to one class of users can significantly degrade the performance for other classes. During these transient periods, it is thus of crucial importance to implement priority mechanisms that conserve the quality of service experienced by the affected classes, while ensuring that the temporarily unstable class is not entirely neglected. In this paper, we examine the complex interaction occurring between several classes of traffic when classes obtain bandwidth proportionally to their incoming traffic. We characterize the evolution of the performance measures of the network from the moment the initial surge takes place until the system reaches its equilibrium. Using a time-space-transition-scaling, we show that the trajectories of the temporarily unstable class can be described by a differential equation, while those of the stable classes retain their stochastic nature. In particular, we show that the temporarily unstable class evolves at a time-scale which is much slower than that of the stable classes. Although the time-scales decouple, the dynamics of the temporarily unstable and the stable classes continue to influence one another. We further proceed to characterize the obtained differential equations for several simple network examples. In particular, the macroscopic asymptotic behavior of the unstable class allows us to gain important qualitative insights on how the bandwidth allocation affects performance. We illustrate these results on several toy examples and we finally build a penalization rule using these results for a network integrating streaming and surging elastic traffic.
Optimization allocation of energy storage for microgrid based on economic dispatch%基于经济调度的微网储能优化配置
Institute of Scientific and Technical Information of China (English)
杨秀; 陈洁; 朱兰; 张美霞; 王海波
2013-01-01
For the uncertainties of renewable energy generation and load, energy storage device plays an important role in ensuring the safe and reliable operation of microgrid system. To accurately analyze the scheme of optimal allocation of energy storage for microgrid which contains various distributed generations, optimization allocation model of energy storage for CHP microgrid based on economic dispatch and heating income is established. A quantitative analysis method for allocating the minimum storage capacity in grid-connected and islanded modes is presented. A microgrid consisting of a wind turbine, photovoltaic cells, a storage battery, a micro turbine, a fuel cell, heating and electric loads is selected as the research object. The improved genetic algorithm is chosen to optimize the output of microsources, and electricity purchases and sales between external network and microgrid. The storage capacities for achieving the minimum comprehensive cost are determined in two operation modes. The validity of the proposed model, dispatch strategy and algorithm is proved by the examples.% 由于可再生能源发电和负荷具有不确定性，蓄电池作为储能装置是保证微网系统安全可靠运行的重要组成部分。为了准确分析含多种分布式电源的微网储能优化配置方案，建立了基于经济调度并计及制热收益的热电联产型微网储能优化配置模型。提出了并网和孤网运行方式下所需配置最小储能容量的定量分析方法，以一个包含风、光、储、微型燃气轮机、燃料电池以及热电负荷的微网为例，运用改进遗传算法优化了不同储能容量下各微源的出力及微网向外网的购售电量，并确定了两种运行方式下实现综合成本最低所需配置的储能容量。通过算例验证了所提模型、策略和算法的有效性。
An ECN-Based Bandwidth Sharing Algorithm for Unicast and Multicast Flows%基于ECN的单播流与多播流间带宽共享算法
Institute of Scientific and Technical Information of China (English)
杨明; 张福炎
2003-01-01
An ECN-based implementing bandwidth-sharing algorithm for unicast and multicast flows is presented.The algorithm uses a bandwidth allocation strategy to give an incentive to multicast flows in bandwidth allocation according to algorithm of the number of receivers, and to assure the unicast flows get their bandwidth shares fairly.Provided best-effort networks, an ECN-based congestion control algorithm is used to implement differentiated service in bandwidth allocation between unicast flows and multicast flows. In implementation, we solve the problems such asreceiver's number estimation, the RTT estimation and compromise between convergence and stability.The simulation results show that the algorithm can implement bandwidth sharing for TCP flows and multicast flows. Atthe same time, the algorithm not only allocates more bandwidth to multicast flows, but promises TCP flows to get their fair bandwidth share.
Phenotypically flexible sex allocation in a simultaneous hermaphrodite
Brauer, Verena S.; Schaerer, Lukas; Michiels, Nico K.
2007-01-01
Previous studies on sex allocation in simultaneous hermaphrodites have typically focused either on evolutionary or one-time, ontogenetic optimization of sex allocation, ignoring variation within an individual's lifetime. Here, we study whether hermaphrodites also possess facultative sex allocation,
Optimized Energy Harvesting, Cluster-Head Selection and Channel Allocation for IoTs in Smart Cities
Directory of Open Access Journals (Sweden)
Saleem Aslam
2016-12-01
Full Text Available This paper highlights three critical aspects of the internet of things (IoTs, namely (1 energy efficiency, (2 energy balancing and (3 quality of service (QoS and presents three novel schemes for addressing these aspects. For energy efficiency, a novel radio frequency (RF energy-harvesting scheme is presented in which each IoT device is associated with the best possible RF source in order to maximize the overall energy that the IoT devices harvest. For energy balancing, the IoT devices in close proximity are clustered together and then an IoT device with the highest residual energy is selected as a cluster head (CH on a rotational basis. Once the CH is selected, it assigns channels to the IoT devices to report their data using a novel integer linear program (ILP-based channel allocation scheme by satisfying their desired QoS. To evaluate the presented schemes, exhaustive simulations are carried out by varying different parameters, including the number of IoT devices, the number of harvesting sources, the distance between RF sources and IoT devices and the primary user (PU activity of different channels. The simulation results demonstrate that our proposed schemes perform better than the existing ones.
Optimized Energy Harvesting, Cluster-Head Selection and Channel Allocation for IoTs in Smart Cities.
Aslam, Saleem; Hasan, Najam Ul; Jang, Ju Wook; Lee, Kyung-Geun
2016-12-02
This paper highlights three critical aspects of the internet of things (IoTs), namely (1) energy efficiency, (2) energy balancing and (3) quality of service (QoS) and presents three novel schemes for addressing these aspects. For energy efficiency, a novel radio frequency (RF) energy-harvesting scheme is presented in which each IoT device is associated with the best possible RF source in order to maximize the overall energy that the IoT devices harvest. For energy balancing, the IoT devices in close proximity are clustered together and then an IoT device with the highest residual energy is selected as a cluster head (CH) on a rotational basis. Once the CH is selected, it assigns channels to the IoT devices to report their data using a novel integer linear program (ILP)-based channel allocation scheme by satisfying their desired QoS. To evaluate the presented schemes, exhaustive simulations are carried out by varying different parameters, including the number of IoT devices, the number of harvesting sources, the distance between RF sources and IoT devices and the primary user (PU) activity of different channels. The simulation results demonstrate that our proposed schemes perform better than the existing ones.
Model and Algorithm for Optimal Allocation of Mix-loading Goods%混装货物优化配置模型及算法
Institute of Scientific and Technical Information of China (English)
俞武扬
2012-01-01
This paper presents an optimal allocation model of mix-loading goods to minimize the total freight. Mix-loading of different goods with different transportation rate, gross weight and volume is the basis of this optimal allocation model. By using two relative lemmas, it proposes a heuristic algorithm to solve this model. Numerical examples are presented to demonstrate the efficiencies of the heuristic algorithm by comparing with a basic Genetic Algorithm(GA). Giving 10 groups random data of 50 piece goods, experimental results show that the average runtime of GA is 2 325 times as much as that of heuristic algorithm, and give 10 groups random data of 200 piece goods, the average runtime of heuristic algorithm is only 4.009 4 s.%为最小化总运费,提出一种混装货物的优化配置模型.根据不同货物的运输费率、实际重量和体积重量完成混装搭配,在证明2个相关引理的基础上设计启发式算法,将其与基本遗传算法进行多组随机计算比较.实验结果表明,对于50件货物的10组随机数据,遗传算法所用平均计算时间是启发式算法的2 325倍,对于200件物品的10组随机数据,启发式算法所用的平均计算时间仅为4.0094s.
Network Bandwidth Utilization Forecast Model on High Bandwidth Network
Energy Technology Data Exchange (ETDEWEB)
Yoo, Wucherl; Sim, Alex
2014-07-07
With the increasing number of geographically distributed scientific collaborations and the scale of the data size growth, it has become more challenging for users to achieve the best possible network performance on a shared network. We have developed a forecast model to predict expected bandwidth utilization for high-bandwidth wide area network. The forecast model can improve the efficiency of resource utilization and scheduling data movements on high-bandwidth network to accommodate ever increasing data volume for large-scale scientific data applications. Univariate model is developed with STL and ARIMA on SNMP path utilization data. Compared with traditional approach such as Box-Jenkins methodology, our forecast model reduces computation time by 83.2percent. It also shows resilience against abrupt network usage change. The accuracy of the forecast model is within the standard deviation of the monitored measurements.
Directory of Open Access Journals (Sweden)
Hai Lan
2015-10-01
Full Text Available This study optimizes the tilt angle of photovoltaic (PV panels on a large oil tanker ship system and considers the impact of partial shading to improve the performance of the PV system. This work presents a novel method that considers the difference between the expected and real outputs of PV modules to optimize the size of energy storage system (ESS. The method also takes into account the cost of wasted power, the capital cost of the system, fuel cost and the CO2 emissions. Unlike on land, power generation using a PV on a ship depends on the date, latitude and longitude of the navigation. Accordingly, this work considers a route from Dalian in China to Aden in Yemen, accounting for the seasonal and geographical variations of solar irradiation. This proposed method adopts five conditions associated with the navigation route to model the total shipload. Various cases are discussed in detail to demonstrate the effectiveness of the proposed algorithm.
Institute of Scientific and Technical Information of China (English)
宋耀莲; 酆广增
2013-01-01
In this paper,we investigate the power allocation schemes of cognitive multi-node relay networks. A simple optimal power allocation (OPA) method is proposed, and the optimal solution is given. We simulate the outage performance of different location of cognitive relay and investigate spectrum sensing and cognitive multi-node relay cooperative transmission. The numerical results show that the outage performance of optimal power allocation is superior to that of equal power allocation ( EPA). Furthermore, there exists an optimal spectrum sensing time to optimize the outage performance of cognitive multi-node relay networks.%研究了认知多中继网络的功率分配方案,提出了简单的最优功率分配(OPA)方法,并给出最优解.仿真了不同的认知中继位置对认知系统中断性能的影响,并联合考虑频谱感知和认知多中继协作传输两个过程.仿真结果表明,文中提出的最佳功率分配方案的中断性能优于等功率分配(EPA)方案,且存在最佳的感知时间使认知多中继网络的中断性能最优.
Black Holes, Bandwidths and Beethoven
Kempf, A
2000-01-01
It is usually believed that a function whose Fourier spectrum is bounded can vary at most as fast as its highest frequency component. This is in fact not the case, as Aharonov, Berry and others drastically demonstrated with explicit counter examples, so-called superoscillations. The claim is that even the recording of an entire Beethoven symphony can occur as part of a signal with 1Hz bandwidth. Superoscillations have been suggested to account e.g. for transplanckian frequencies of black hole radiation. Here, we give an exact proof for generic superoscillations. Namely, we show that for every fixed bandwidth there exist functions which pass through any finite number of arbitrarily prespecified points. Further, we show that the behavior of bandlimited functions can be reliably characterized through an uncertainty relation for the standard deviation of the signals' samples taken at the Nyquist rate. This uncertainty relation generalizes to time-varying bandwidths.
Castaño Moraga, C. A.; Suárez Santana, E.; Sabbagh Rodríguez, I.; Nebot Medina, R.; Suárez García, S.; Rodríguez Alvarado, J.; Piernavieja Izquierdo, G.; Ruiz Alzola, J.
2010-09-01
Wind farms authorization and power allocations to private investors promoting wind energy projects requires some planification strategies. This issue is even more important under land restrictions, as it is the case of Canary Islands, where numerous specially protected areas are present for environmental reasons and land is a scarce resource. Aware of this limitation, the Regional Government of Canary Islands designed the requirements of a public tender to grant licences to install new wind farms trying to maximize the energy produced in terms of occupied land. In this paper, we detail the methodology developed by the Canary Islands Institute of Technology (ITC, S.A.) to support the work of the technical staff of the Regional Ministry of Industry, responsible for the evaluation of a competitive tender process for awarding power lincenses to private investors. The maximization of wind energy production per unit of area requires an exhaustive wind profile characterization. To that end, wind speed was statistically characterized by means of a Weibull probability density function, which mainly depends on two parameters: the shape parameter K, which determines the slope of the curve, and the average wind speed v , which is a scale parameter. These two parameters have been evaluated at three different heights (40,60,80 m) over the whole canarian archipelago, as well as the main wind speed direction. These parameters are available from the public data source Wind Energy Map of the Canary Islands [1]. The proposed methodology is based on the calculation of an initially defined Energy Efficiency Basic Index (EEBI), which is a performance criteria that weighs the annual energy production of a wind farm per unit of area. The calculation of this parameter considers wind conditions, windturbine characteristics, geometry of windturbine distribution in the wind farm (position within the row and column of machines), and involves four steps: Estimation of the energy produced by
Bandwidth-sharing in LHCONE, an analysis of the problem
Wildish, T.
2015-12-01
The LHC experiments have traditionally regarded the network as an unreliable resource, one which was expected to be a major source of errors and inefficiency at the time their original computing models were derived. Now, however, the network is seen as much more capable and reliable. Data are routinely transferred with high efficiency and low latency to wherever computing or storage resources are available to use or manage them. Although there was sufficient network bandwidth for the experiments’ needs during Run-1, they cannot rely on ever-increasing bandwidth as a solution to their data-transfer needs in the future. Sooner or later they need to consider the network as a finite resource that they interact with to manage their traffic, in much the same way as they manage their use of disk and CPU resources. There are several possible ways for the experiments to integrate management of the network in their software stacks, such as the use of virtual circuits with hard bandwidth guarantees or soft real-time flow-control, with somewhat less firm guarantees. Abstractly, these can all be considered as the users (the experiments, or groups of users within the experiment) expressing a request for a given bandwidth between two points for a given duration of time. The network fabric then grants some allocation to each user, dependent on the sum of all requests and the sum of available resources, and attempts to ensure the requirements are met (either deterministically or statistically). An unresolved question at this time is how to convert the users’ requests into an allocation. Simply put, how do we decide what fraction of a network's bandwidth to allocate to each user when the sum of requests exceeds the available bandwidth? The usual problems of any resourcescheduling system arise here, namely how to ensure the resource is used efficiently and fairly, while still satisfying the needs of the users. Simply fixing quotas on network paths for each user is likely to lead
Efficient Bandwidth Management for Ethernet Passive Optical Networks
Elrasad, Amr Elsayed M.
2016-05-15
The increasing bandwidth demands in access networks motivates network operators, networking devices manufacturers, and standardization institutions to search for new approaches for access networks. These approaches should support higher bandwidth, longer distance between end user and network operator, and less energy consumption. Ethernet Passive Optical Network (EPON) is a favorable choice for broadband access networks. EPONs support transmission rates up to 10 Gbps. EPONs also support distance between end users and central office up to 20 Km. Moreover, optical networks have the least energy consumption among all types of networks. In this dissertation, we focus on reducing delay and saving energy in EPONs. Reducing delay is essential for delay-sensitive traffic, while minimizing energy consumption is an environmental necessity and also reduces the network operating costs. We identify five challenges, namely excess bandwidth allocation, frame delineation, congestion resolution, large round trip time delay in long-reach EPONs (LR-EPONs), and energy saving. We provide a Dynamic Bandwidth Allocation (DBA) approach for each challenge. We also propose a novel scheme that combines the features of the proposed approaches in one highly performing scheme. Our approach is to design novel DBA protocols that can further reduce the delay and be simultaneously simple and fair. We also present a dynamic bandwidth allocation scheme for Green EPONs taking into consideration maximizing energy saving under target delay constraints. Regarding excess bandwidth allocation, we develop an effective DBA scheme called Delayed Excess Scheduling (DES). DES achieves significant delay and jitter reduction and is more suitable for industrial deployment due to its simplicity. Utilizing DES in hybrid TDM/WDM EPONs (TWDM-EPONs) is also investigated. We also study eliminating the wasted bandwidth due to frame delineation. We develop an interactive DBA scheme, Efficient Grant Sizing Interleaved
Upgrade trigger: Bandwidth strategy proposal
Boettcher, Thomas Julian; Meloni, Simone; Whitehead, Mark Peter; Williams, Mark Richard James
2017-01-01
This document describes a proposed selection strategy for the upgrade trigger using charm signals as a benchmark. The Upgrade trigger uses a 'Run2-like' sequence consisting of a first and second stage, in between which the calibration and alignment is performed. The first stage, HLT1, uses an inclusive strategy to select beauty and charm, while the second stage uses offline-quality exclusive selections. A novel genetic algorithm-based bandwidth division is performed at the second stage to maximise the output of useful physics events, and a range of possible signal efficiencies are presented as a function of the available bandwidth.
Mining Industry Energy Bandwidth Study
Energy Technology Data Exchange (ETDEWEB)
none,
2007-07-01
The Industrial Technologies Program (ITP) relies on analytical studies to identify large energy reduction opportunities in energy-intensive industries and uses these results to guide its R&D portfolio. The energy bandwidth illustrates the total energy-saving opportunity that exists in the industry if the current processes are improved by implementing more energy-efficient practices and by using advanced technologies. This bandwidth analysis report was conducted to assist the ITP Mining R&D program in identifying energy-saving opportunities in coal, metals, and mineral mining. These opportunities were analyzed in key mining processes of blasting, dewatering, drilling, digging, ventilation, materials handling, crushing, grinding, and separations.
最适化逆向运筹服务产能配置%Optimizing Service Capacity Allocation in Reverse Logistics Chain
Institute of Scientific and Technical Information of China (English)
廖明癸
2012-01-01
逆向运筹的规划与管理对产业的营运绩效有着相当显著的重要性.文章旨在建立服务策略与成本分析数学模式,在最小化整体服务成本的考虑下,设计最适化区域策略伙伴的选定与服务产能配置,由于前后不同等级服务点的选定会彼此牵制服务成本,影响最终整体成本.因此,以非线性规划求解服务策略分析问题,范例说明在设定服务点选择与无产能限制条件下,最大与最小整体服务成本为5.54％及3.11％销售额,相差近78.1％,约2.43％销售额,严重影响公司最后营运绩效与公司竞争力.后续研究可依本文数学模式,加入不同产业特性与限制条件,或增加环境冲击与客户满意度成本考虑,找出最适化不同服务等级服务点选定与产能配置.%The strategy and management of reverse logistics significantly affects business performance. A mathematical model is presented here to optimize service strategy for third-party logistics partners (3PLs) selection and capacity allocation in balance of the consideration of customer satisfaction and total warranty claims. This service strategy analysis is a nonlinear programming problem owing to each service level warranty claims will depend on previous and following service level arrangement. Example shows the gap of warranty claim may up to 2. 43% of revenues, 78. 1% difference between optimal solution 3. 11% and worst scenario 5. 54% of revenues. It seriously impacts overall business performance and company competitiveness. To add extra service cost element into the presented mathematical model here, environment impact or customer satisfaction, is interesting for research following based on different industrial constraints, trying to optimize 3PLs location and capacity allocation.
Novel Robust Optimization and Power Allocation of Time Reversal-MIMO-UWB Systems in an Imperfect CSI
Directory of Open Access Journals (Sweden)
Sajjad Alizadeh
2013-03-01
Full Text Available Time Reversal (TR technique is an attractive solution for a scenario where the transmission system employs low complexity receivers with multiple antennas at both transmitter and receiver sides. The TR technique can be combined with a high data rate MIMO-UWB system as TR-MIMO-UWB system. In spite of TR's good performance in MIMO-UWB systems, it suffers from performance degradation in an imperfect Channel State Information (CSI case. In this paper, at first a robust TR pre-filter is designed together with a MMSE equalizer in TR-MIMO-UWB system where is robust against channel imperfection conditions. We show that the robust pre-filter optimization technique, considerably improves the BER performance of TR-MIMO-UWB system in imperfect CSI, where temporal focusing of the TR technique is kept, especially for high SNR values. Then, in order to improve the system performance more than ever, a power loading scheme is developed by minimizing the average symbol error rate in an imperfect CSI. Numerical and simulation results are presented to confirm the performance advantage attained by the proposed robust optimization and power loading in an imperfect CSI scenario.
Directory of Open Access Journals (Sweden)
Basil eWahn
2016-03-01
Full Text Available Humans constantly process and integrate sensory input from multiple sensory modalities. However, the amount of input that can be processed is constrained by limited attentional resources. A matter of ongoing debate is whether attentional resources are shared across sensory modalities, and whether multisensory integration is dependent on attentional resources. Previous research suggested that the distribution of attentional resources across sensory modalities depends on the the type of tasks. Here, we tested a novel task combination in a dual task paradigm: Participants performed a self-terminated visual search task and a localization task in either separate sensory modalities (i.e., haptics and vision or both within the visual modality. Tasks considerably interfered. However, participants performed the visual search task faster when the localization task was performed in the tactile modality in comparison to performing both tasks within the visual modality. This finding indicates that tasks performed in separate sensory modalities rely in part on distinct attentional resources. Nevertheless, participants integrated visuotactile information optimally in the localization task even when attentional resources were diverted to the visual search task. Overall, our findings suggest that visual search and tactile localization partly rely on distinct attentional resources, and that optimal visuotactile integration is not dependent on attentional resources.
Wind speed spatial correlation and optimal wind power allocation%风速空间相关性和最优风电分配
Institute of Scientific and Technical Information of China (English)
简金宝; 刘思东
2013-01-01
Geographic diversification of wind farms can smooth out the variability of wind power. The paper applies copula function and mean-variance model to study the wind speed spatial correlation and optimal wind power allocation. The maximum likelihood method is utilized to choose appropriate copula function to describe the correlation of wind speeds, and the pairwise rank correlation coefficients of wind speeds are calculated by copula, while the relationship between rank correlation and wind farms distance is fitted by least squares method. A new mean-variance model is constructed to optimize wind power allocation, where return is defined as the capacity factor, and risk is defined as the standard deviation of hourly wind power variation, and linear correlation is replaced by rank correlation. Taking Holland 40 wind farms as an example, the results show that Gumbel copula and t copula present a better fit for wind speeds correlation, and the rank correlation tends to decrease by 0.1 with a increasing distance of 100 km. By solving the mean-variance model, the optimal combination of wind power is obtained, and wind power variability drops by a maximum of 70%comparing with the single wind farm, where off-shore wind farms play a more important role. Under the guidance of this model, an optimal wind power allocation strategy can be used to reduce the system risk and cost due to wind power variability.%风电场分布的地域多元化能够平滑风电波动。提出基于copula函数和均值-方差模型研究分布在不同位置风电场风速空间相关性和最优风电分配。利用极大似然法选取合适的copula函数描述风速间的相关关系，计算出风速间基于copula的秩相关系数，并借助最小二乘法拟合秩相关系数和风电场距离的关系。构造适合风电场的均值-方差模型优化风电的分配，其中风场的容量因子表示收益，风电前后时刻出力变化的标准差表示风险，线性相关系数用
LTE Dynamic Resource Allocation Algorithm based on QoS Optimization%基于QoS优化的LTE动态资源分配算法
Institute of Scientific and Technical Information of China (English)
郑智华
2014-01-01
文中对下一代移动通信系统LTE的动态资源分配算法进行研究，通过分析不同业务类型的QoS需求，设定用户使用业务类型的QoS参数，确定优先级大小，通过QOS 来表示不同业务的时间延迟；同时对小区切换用户的优先等级分析，设置了切换因子，提出了基于QoS优化的改进算法，并进行系统仿真计算分析，结果表明和传统算法相比，系统性能得到有效改进，进一步提高了系统公平性并增加小区吞吐量。%LTE dynamic resource allocation algorithm for the next generation mobile communication systems is discussed. Through the analysis on different types of traffic QoS requirements, the QoS parameters of us-er service types are determined and priority levels also established, and QoS is used to display different service time-delays. Meanwhile, the handoff factor is also set up through priority analysis of the cell hand-off users. Thus the modified dynamic resource allocation algorithm based on QoS optimization is further proposed and simulated. Simulation results show that the system performance is effectively improved, mo-reover,the system fairness and cell throughput also increased as compared with traditional algorithms.
Global path and bandwidth scheduling in inter-data-center IP/optical transport network
Zhao, Yang; Wang, Lei; Chen, Xue; Yang, Futao; Shi, Sheping; Wang, Huitao
2016-07-01
We propose a flow-oriented global path and bandwidth scheduling scheme for inter-data-center IP/optical network. To improve the throughput of network and reduce the mutual impact between flows, we allow each flow to be carried by a multi-path optical channel data unit (ODU) channel. In addition bandwidth is allocated to flows fairly according to weight. Simulation results reveal that compared to high-priority-first mechanism, the method proposed improves average bandwidth allocation ratio by about 15% and allocation fairness between flows by 30%. Furthermore, compared to pure IP network, router ports are significantly saved and network cost can be reduced by up to 40% with scheme proposed in unified controlled IP/optical network.
Energy-Efficient Power Allocation of Cognitive Radio Systems without CSI at the Transmitter
Sboui, Lokman
2015-01-07
Two major issues are facing today’s wireless communications evolution: -Spectrum scarcity: Need for more bandwidth. As a solution, the Cognitive Radio (CR) paradigm, where secondary users (unlicensed) share the spectrum with licensed users, was introduced. -Energy consumption and CO2 emission: The ICT produce 2% of global CO2 emission (equivalent to the aviation industry emission). The cellular networks produces 0.2%. As solution energy efficient systems should be designed rather than traditional spectral efficient systems. In this work, we aim to determine the optimal energy efficient power allocation of CR when the channel state information at the transmitter CSI-T is not available.
DEFF Research Database (Denmark)
Delikaraoglou, Stefanos; Pinson, Pierre; Eriksson, Robert
2015-01-01
of the power system depends both on the technical parameters of its components, i.e., generators and transmission infrastructure, as well as on the operational practices that make optimal use of the available assets. This work focuses on alternative market designs that enable sharing of cross-border balancing...... and the uncertainty arising from their partial predictability. Considering that the existing setup of the European electricity markets promotes the spatial coordination of neighbouring power systems only on the day-ahead market stage, regional system operators have to rely mainly on their internal balancing resources...... resources between adjacent power systems through High Voltage Direct Current (HVDC) interconnections which provide increased controllability. In this context, we formulate a stochastic market-clearing algorithm that attains full spatio-temporal integration of reserve capacity, day-ahead and balancing...
Institute of Scientific and Technical Information of China (English)
沈启霞; 吴德宇
2015-01-01
Through the investigation to the universities teachers and students status resources in Henan Province, we find out the basic situation of university teacher resources and student status in Henan province. In view of the specific problem of teacher resources optimization disposition in Henan province, we put forward some reasonable suggestions of college teacher resources optimization allocation in Henan province.%Through the investigation to the universities teachers and students status resources in Henan Province, we find out the basic situation of university teacher resources and student status in Henan province. In view of the specific problem of teacher resources optimization disposition in Henan province, we put forward some reasonable suggestions of college teacher resources optimization allocation in Henan province.
A Novel Bandwidth Efficient Transmit Diversity Scheme Based on Water-filling
Institute of Scientific and Technical Information of China (English)
SHENCong; DAILin; ZHOUShidong; YAOYan
2004-01-01
In this paper we propose a novel bandwidth efficient transmit diversity scheme based on layered space-time architecture, in which Channel state information (CSI) is fully utilized to maximize channel capacity according to water-filling principle. It is shown that compared with V-BLAST, this new scheme can maintain the same high bandwidth efficiency, but achieve much better performance thanks to more effective transmission power allocation and diversity gain.
Bandwidth Partitioning in Decentralized Wireless Networks
Jindal, Nihar; Weber, Steven
2007-01-01
This paper addresses the following question, which is of interest in the design of a multiuser decentralized network. Given a total system bandwidth of W Hz and a fixed data rate constraint of R bps for each transmission, how many frequency slots N of size W/N should the band be partitioned into in order to maximize the number of simultaneous links in the network? Dividing the available spectrum results in two competing effects. On the positive side, a larger N allows for more parallel, non-interfering communications to take place in the same area. On the negative side, a larger N increases the SINR requirement for each link because the same information rate must be achieved over less bandwidth, which in turn increases the area consumed by each transmission. Exploring this tradeoff and determining the optimum value of N in terms of the system parameters is the focus of the paper. Using stochastic geometry, the optimal SINR threshold - which directly corresponds to the optimal spectral efficiency - is derived ...
Black holes, bandwidths and Beethoven
Kempf, Achim
2000-04-01
It is usually believed that a function φ(t) whose Fourier spectrum is bounded can vary at most as fast as its highest frequency component ωmax. This is, in fact, not the case, as Aharonov, Berry, and others drastically demonstrated with explicit counterexamples, so-called superoscillations. It has been claimed that even the recording of an entire Beethoven symphony can occur as part of a signal with a 1 Hz bandwidth. Bandlimited functions also occur as ultraviolet regularized fields. Their superoscillations have been suggested, for example, to resolve the trans-Planckian frequencies problem of black hole radiation. Here, we give an exact proof for generic superoscillations. Namely, we show that for every fixed bandwidth there exist functions that pass through any finite number of arbitrarily prespecified points. Further, we show that, in spite of the presence of superoscillations, the behavior of bandlimited functions can be characterized reliably, namely through an uncertainty relation: The standard deviation ΔT of samples φ(tn) taken at the Nyquist rate obeys ΔT>=1/4ωmax. This uncertainty relation generalizes to variable bandwidths. For ultraviolet regularized fields we identify the bandwidth as the in general spatially variable finite local density of degrees of freedom.
计及低碳效益的分布式发电优化配置%Optimal Allocation of Distributed Generation Considering Low-Carbon Effect
Institute of Scientific and Technical Information of China (English)
邓晶; 周任军; 郑思; 任俞霖
2012-01-01
The low carbon analysis of all aspects of power system was made. According to the optimal allocation of distributed generation (DG) in distribution network, three important indexes of low-carbon expense, voltage security and active power loss were introduced to evaluate distributed generation profits, and on this basis, the model of DG multi-objective optimization was established. The multi-objective program was turned into a single objective program by the maximum satisfaction method. An artificial intelligent algorithm named plant growth simulation algorithm (PGSA) was used to solve the optimal planning problem of DG. The example shows that the location and capacity of DG determined by proposed model in distribution network can effectively decrease the carton emission, improve the system voltage and reduce the active power loss.%首先对电力系统各个环节进行低碳分析,针对配电网分布式发电DG(distributed generation)优化配置问题,提出了低碳费用、电压安全、有功网损这三个评估配电网效益的重要指标,在此基础上建立分布式发电多目标优化配置模型,应用最大满意度法将多目标规划转化成单目标规划问题,并用模拟植物生长算法PG-SA(plant growth simulation algorithm)对上述模型进行求解.算例表明该模型确定的分布式电源在配电网的位置和容量可有效减少碳排放、提高系统运行电压,降低有功网损.
Energy-efficient routing, modulation and spectrum allocation in elastic optical networks
Tan, Yanxia; Gu, Rentao; Ji, Yuefeng
2017-07-01
With tremendous growth in bandwidth demand, energy consumption problem in elastic optical networks (EONs) becomes a hot topic with wide concern. The sliceable bandwidth-variable transponder in EON, which can transmit/receive multiple optical flows, was recently proposed to improve a transponder's flexibility and save energy. In this paper, energy-efficient routing, modulation and spectrum allocation (EE-RMSA) in EONs with sliceable bandwidth-variable transponder is studied. To decrease the energy consumption, we develop a Mixed Integer Linear Programming (MILP) model with corresponding EE-RMSA algorithm for EONs. The MILP model jointly considers the modulation format and optical grooming in the process of routing and spectrum allocation with the objective of minimizing the energy consumption. With the help of genetic operators, the EE-RMSA algorithm iteratively optimizes the feasible routing path, modulation format and spectrum resources solutions by explore the whole search space. In order to save energy, the optical-layer grooming strategy is designed to transmit the lightpath requests. Finally, simulation results verify that the proposed scheme is able to reduce the energy consumption of the network while maintaining the blocking probability (BP) performance compare with the existing First-Fit-KSP algorithm, Iterative Flipping algorithm and EAMGSP algorithm especially in large network topology. Our results also demonstrate that the proposed EE-RMSA algorithm achieves almost the same performance as MILP on an 8-node network.
基于分段迭代法的 PMU 的优化配置研究%Research on optimal PMU allocation based on section iterative method
Institute of Scientific and Technical Information of China (English)
赵辉; 赵少华; 王红君; 岳有军
2016-01-01
对电力系统中有限个数目PMU的优化配置进行研究。采用分段迭代法对PMU的优化配置进行研究。该法假设最初每个节点均安装有PMU。第一阶段和第二阶段的迭代算法用来去除那些不太重要的节点的PMU配置，并保留节点位置重要的PMU的配置。第三阶段的迭代算法则对前两阶段的PMU数目进行进一步的最小化，并且充分考虑电力系统全网的可观性，使得该法达到PMU的最优配置。通过在IEEE 14和IEEE 30节点上进行仿真验证，并与现有的优先算法在计算时间上进行对比，证明该法在计算时间上的优越性，及该法的有效性。%This paper conduct the research on the optimal allocation of a limited number of PMU in power system de-vice.A three-stage method will be adopted to study theoptimal allocation of PMU.The method assumes that each bus is installed with PMU initially.The first stage and the second stage of iterative algorithmis are used to remove those less important buses of the PMU configuration, and keep the important position of the buses PMU configuration.The third stage of iterative algorithm makes a further minimize of the first stage and the second stage, and considering the observability of power system, to ensure the optimal configuration of PMU.According to the simulation verification on IEEE 14 bus and IEEE 30 bus system, and compare with the existing priority algorithm in computation time, the re-sults show that the proposed method has superiority in computation time, and the validity of this method.
Directory of Open Access Journals (Sweden)
Kranti Suresh Vora
Full Text Available Gujarat, a western state of India, has seen a steep rise in the proportion of institutional deliveries over the last decade. However, there has been a limited access to cesarean section (C-Section deliveries for complicated obstetric cases especially for poor rural women. C-section is a lifesaving intervention that can prevent both maternal and perinatal mortality. Poor women bear a disproportionate burden of maternal mortality, and lack of access to C-section, especially for these women, is an important contributor for high maternal and perinatal mortality in resource limited settings. To improve access for this underserved population in the context of inadequate public provision of emergency obstetric services, the state government of Gujarat initiated a public private partnership program called "Chiranjeevi Yojana" (CY in 2005 to increase the number of facilities providing free C-section services. This study aimed to analyze the current availability of these services in three districts of Gujarat and to identify the best locations for additional service centres to optimize access to free C-section services using Geographic Information System technology.Supply and demand for obstetric care were calculated using secondary data from sources such as Census and primary data from cross-sectional facility survey. The study is unique in using primary data from facilities, which was collected in 2012-13. Information on obstetric beds and functionality of facilities to calculate supply was collected using pretested questionnaire by trained researchers after obtaining written consent from the participating facilities. Census data of population and birth rates for the study districts was used for demand calculations. Location-allocation model of ArcGIS 10 was used for analyses.Currently, about 50 to 84% of populations in all three study districts have access to free C-section facilities within a 20km radius. The model suggests that about 80-96% of the
Energy Technology Data Exchange (ETDEWEB)
Dayem, H.A.; Ostenak, C.A.; Gutmacher, R.G.; Kern, E.A.; Markin, J.T.; Martinez, D.P.; Thomas, C.C. Jr.
1982-07-01
This report describes the conceptual design of a materials accounting system for the feed preparation and chemical separations processes of a fast breeder reactor spent-fuel reprocessing facility. For the proposed accounting system, optimization techniques are used to calculate instrument measurement uncertainties that meet four different accounting performance goals while minimizing the total development cost of instrument systems. We identify instruments that require development to meet performance goals and measurement uncertainty components that dominate the materials balance variance. Materials accounting in the feed preparation process is complicated by large in-process inventories and spent-fuel assembly inputs that are difficult to measure. To meet 8 kg of plutonium abrupt and 40 kg of plutonium protracted loss-detection goals, materials accounting in the chemical separations process requires: process tank volume and concentration measurements having a precision less than or equal to 1%; accountability and plutonium sample tank volume measurements having a precision less than or equal to 0.3%, a shortterm correlated error less than or equal to 0.04%, and a long-term correlated error less than or equal to 0.04%; and accountability and plutonium sample tank concentration measurements having a precision less than or equal to 0.4%, a short-term correlated error less than or equal to 0.1%, and a long-term correlated error less than or equal to 0.05%. The effects of process design on materials accounting are identified. Major areas of concern include the voloxidizer, the continuous dissolver, and the accountability tank.
Energy Technology Data Exchange (ETDEWEB)
Dayem, H.A.; Ostenak, C.A.; Gutmacher, R.G.; Kern, E.A.; Markin, J.T.; Martinez, D.P.; Thomas, C.C. Jr.
1982-07-01
This report describes the conceptual design of a materials accounting system for the feed preparation and chemical separations processes of a fast breeder reactor spent-fuel reprocessing facility. For the proposed accounting system, optimization techniques are used to calculate instrument measurement uncertainties that meet four different accounting performance goals while minimizing the total development cost of instrument systems. We identify instruments that require development to meet performance goals and measurement uncertainty components that dominate the materials balance variance. Materials accounting in the feed preparation process is complicated by large in-process inventories and spent-fuel assembly inputs that are difficult to measure. To meet 8 kg of plutonium abrupt and 40 kg of plutonium protracted loss-detection goals, materials accounting in the chemical separations process requires: process tank volume and concentration measurements having a precision less than or equal to 1%; accountability and plutonium sample tank volume measurements having a precision less than or equal to 0.3%, a shortterm correlated error less than or equal to 0.04%, and a long-term correlated error less than or equal to 0.04%; and accountability and plutonium sample tank concentration measurements having a precision less than or equal to 0.4%, a short-term correlated error less than or equal to 0.1%, and a long-term correlated error less than or equal to 0.05%. The effects of process design on materials accounting are identified. Major areas of concern include the voloxidizer, the continuous dissolver, and the accountability tank.
Study of Water Resources Optimal Allocation Based on Particle Swarm Optimization%基于粒子群算法的水资源优化配置研究
Institute of Scientific and Technical Information of China (English)
沙金霞; 刘彬; 谢新民; 鹿海员
2012-01-01
为了合理分配引大济湟工程从大通河调出的7.5×108 m3水量,以满足引大济湟工程受水区的生活、生产及生态用水需求,通过建立以供水净效益最大、供水系统总缺水量最小为目标函数的水资源优化配置模型,运用粒子群算法得到了受水区4类水源、5类用水户在2015、2020、2030三个规划水平年的多年平均情况下的水资源优化配置方案.结果表明,2015、2020、2030年净外调水量分别为3.10×108、6.05×108、7.34×10 8 m3,缺水量分别为0.69×108、0.64×108、2.15×108 m3,部分区域农业用水存在缺口,仍需采取必要的节水措施.%In order to allocate reasonably the 7. 5 X 108m3 water resources transfer from Datong river to Huangshui river and satisfy the demand of domestic water, production water and ecological water of Yindajihuang benefited regions, water resources optimal allocation model is established by taking maximization water supply net benefits and minimization water shortage of water supply system as the objective function. And water resources optimal allocation program of four kinds of water sources and five kinds of water sectors in yearly average at the 2015, 2020, 2030 target level year is ob tained with particle swarm optimization. The results show that in 2015, 2020, 2030, the net diversion water is 3. 10× 108m3 , 6. 05×108m3 , 7. 34×108m3, respectively; the shortage water is 0. 69×108m3 , 0. 64×108m3, 2. 15×108m3, re spectively; there is still a gap of agriculture irrigation in some areas; so it is important to take necessary water saving measures.
National Research Council Canada - National Science Library
Zhao, Xiujuan; Xu, Wei; Ma, Yunjia; Hu, Fuyu
2015-01-01
The correct location of earthquake emergency shelters and their allocation to residents can effectively reduce the number of casualties by providing safe havens and efficient evacuation routes during...