In practice, both comprehensive hospital (e.g. AAA hospital) and primary hospital (e.g. community hospital) can exist in healthcare system, where the comprehensive hospital can provide a guaranteed service, but the waiting time of patients is relatively long. By contrast, the primary hospital is less congested, but the patients cannot be treated if the illness is found to be severe. Then the trade-off between efficiency (primary hospital) and quality (comprehensive hospital) should be considered. In this paper, we consider a resource allocation problem in a public service system with multi-type service providers and patients. To capture the interactions between the multi-type hospitals, a queueing-game-theoretical model is established. And we obtain the following results. First, the socially optimal reimbursement policy is obtained, and the sensitivities of parameters are examined, which indicate that, somewhat interestingly, both the optimal budget to primary hospital and the maximal social welfare are non-monotone in the effectiveness parameter or the joining probability of patients. Second, by comparing the socially optimal strategy with individually equilibrium strategy, we find that individual behaviour of patients does not necessarily lead to systems more congested than what is socially desirable. Third, we demonstrate the robustness of our model by extending it to a three-level system and a system with multiple parallel primary hospitals.

As one of the most important public transportation facilities in the city, urban rail transit facilities meet a large number of travel needs of the public, however, they are not the most important public transportation facilities in the city. Since most of the rail transit facilities are underground spaces, they are characterized by large flows of people and confined spaces, which can easily cause major disasters in the event of a disaster. Personnel injuries, therefore, are especially important for the study of passenger disaster evacuation in rail transit. The thesis proposes a theory of passenger evacuation in urban rail transit hubs based on system simulation, and studies the platform structure, platform structure, and platform structure of rail transit hubs. The influences of crowd size and crowd density on passenger evacuation, and the design of optimal evacuation scenarios for emergencies through simulation experiments. Evacuation paths and methods. Simulation results show that the evacuation strategy combining the three factors produces good results and can solve the bottleneck problem of emergency evacuation at the station. Reducing casualties, providing guidance for the design of emergency evacuation plans for urban rail stations, and providing guidance for disaster evacuation strategies in stations. Provide informative advice on design.

Text abstracting is widely used in search engine, text database, information filtering. In the text extraction method, the mathematical model is usually established first and extracted by the model, but this method is not effective in solving nonlinear problems. Support vector machine (SVM), based on statistical learning theory, converts a certain amount of text into vectorized training text data for extraction. This paper adopts support vector machine (SVM) to study text extraction in telecommunication field, and we obtained good results.

The paper investigates the initiation mechanism of debris flow through the survey with detailed analysis for several field debris flow events. The field investigation shows that the debris flow evolution includes distinct three stages: the soil structure changes and forms slide debris, slide debris mobilizes into debris flow, and the debris flow slips a long distance along the slope. In order to reappear and explain the aforementioned phenomenon existing in the initiation procedure of debris flow, the vane shear rheometer device is developed to test the shear rheology properties of debris source. Subsequently, the shear rheological tests with water drained out are performed utilizing the fine sand as tested material. A series of tests are performed and experimental data are obtained including the shear strain, negative pressure, water content, shear velocity, shear resistance, pore water pressure, and line displacements on the shear surface. Based on the changes of water content and negative pressure, the unsaturated permeability coefficients are obtained to explain the water-free infiltration process in the tests. According to the changes of shear velocity and experimental phenomena, the debris flow evolution is divided into three stages including the antecedent rainfall stage, accelerated initiation stage, and long-distance movement stage, which is similar to the three corresponding stages existing in the filed debris flow events. According to the analysis of test results, the mechanics of the debris flow initiation could be explained as the following: the debris source’s shear strength decreased to the value of yield shear strength, the peak shear strength available during undrained loading of a saturated, contractive, sandy soil, after a long period of antecedent rainfall infiltration. The tiny cracks expended to form connecting crack surfaces in the debris source interior, and then the debris source moves rapidly under the continuous rainfall, indicating the debris flow initiation. During the long-distance movement stage, the particles of debris source on the shear surface rearrange and form a smooth slide surface as the values of water content and pore water pressure increase. Therefore, the increase of water content and the decrease of negative pressure caused the soil shear strength decaying, and that is the major reasons of debris flow initiation. In addition, the other key reason is the particles rearranging on the initiation surfaces. The vane shear rheometer apparatus and corresponding test results have provided a more concrete and rational mechanism interpretation for debris flow initiation.

This paper is concentrated on the service provider's optimal risky decision making problems in a quality-based make-to-order/service system. Different from a traditional operational management, consumers in our model have their own willingness to wait or leave when procuring service. We derive the risking pricing strategies under the interactions between service quality and consumers' intensity. Making the quality and service speed trade-off, the optimal pricing strategies and optimal service rate are obtained for the monopoly provider and the social planner respectively. We also find how the service provider's risk coefficient affect its optimal strategies as well as the consumers' equilibrium strategies through numerical examples.

This article investigates joining strategies and admission control policy for secondary users (SUs) with retrial behavior in a cognitive radio (CR) system where a single primary user (PU) coexists with multiple SUs. Under a certain reward-cost structure, SUs opportunistically access the PU band when it is not occupied by the PU. If the band is available upon arrival, an SU decides with a probability either to use the band immediately or to balk the system. If the band is occupied, the SU must decide whether to enter the system as a retrial customer or to leave the system. Once the PU requests for service, the service of SU being served, if any, will be interrupted, and the interrupted SU leaves the band and retries for service after a random amount of time. In this article, we study the equilibrium behavior of non-cooperative SUs who want to maximize their benefit in a selfish, distributed manner with delay-sensitive utility function. The socially optimal strategies of SUs are also derived. To utilize the PU band more efficiently and rationally, an admission control policy is proposed to regulate SUs who enter the system in order to eliminate the gap between the individually and socially optimal strategies.

This paper is concerned with a single server retrial queue with a finite number of sources with second optional service. This queueing system assumes that each source can generate a primary call to request service when it is free. After the first phase service, the customer will choose the second phase service with probability p. Our analysis extends previous work on this topic and we can use method of discrete transformation to get some more general results on the length of the queue, busy period and waiting time. Numerical examples show the influence of key parameters on the performance of the system.

This paper conducts the game-theoretic analysis of the behavior of secondary users (SUs) in a cognitive radio (CR) system with a single primary user (PU) band and sensing failures. It is assumed that the sensing errors occur only when an SU is being served by the PU band. It may incorrectly detect there is no PU accessing to the band (called misdetection), or it may wrongly sense that there is an incoming PU but in fact it is not true (called false alarm). When a misdetection occurs, the PU will be blocked and the ongoing SU will drop into a retrial pool called orbit in which it can retry for service after some random time. When a false alarm occurs, the ongoing SU will drop into the retrial orbit. That is, both errors will degrade the quality of service of the system. First, we investigate how the arriving SUs make decisions on whether to join or balk the system which can be studied as a non-cooperative game. We obtain the equilibrium behavior of SUs who want to maximize their benefit in a selfish distributed manner. Second, we derive the socially optimal strategies of SUs from the perspective of the social planner. To use the PU band more efficiently, an appropriate admission fee imposed on each joining SU is proposed based on the gap between the equilibrium strategy and the socially optimal strategy. Finally, theoretic results are validated by numerical analysis and the effect of various parameters on the behavior of SUs is illustrated.

This paper is concerned with a double-ended queueing system which is motivated by the passenger-taxi problem under a gated policy. This policy makes taxis start to balk when the taxi queue length reaches an upper limit and to join again when the taxi queue length is reduced to a lower limit. In our model, we focus on the strategic behavior and social optimal strategies of arriving passengers under three information scenarios: (a) unobservable case; (b) almost unobservable case; and (c) observable case. In the unobservable and the almost unobservable cases, we derive the equilibrium joining strategies for arriving passengers and analyze the social welfare optimization problems. In the observable case, we consider the pure threshold-type policies from the perspectives of individual's strategic behavior and the social welfare optimization, respectively. Then, we present some numerical examples to show how the gated policy plays an important role from the social planner's point of view. Some comparisons between our policy with those studied in the literature have been made and some advantages of our policy are demonstrated.

We consider the strategic behavior of secondary users (SUs) in a cognitive radio system where SUs opportunistically share a single primary user (PU) band over a coverage area. The service of an SU can be interrupted by a PU in a preemptive manner, and the interrupted SU may abandon the system or wait until the PU band is sensed available. In the latter case, if spectrum sensing errors occur, they will cause misdetections and false alarms which impact the system’s performance heavily. In this paper, we model this problem as a retrial queueing system with server breakdowns and recoveries in which the interrupted SUs are treated as retrial customers. They will retry for using the PU band after some period of time due to interruptions or misdetections. The arrival of a PU during service of an SU is modeled as a server breakdown, and the recovery time is equivalent to the service time of this PU. We focus on the behavior of arriving SUs who can make decisions on whether to join the system or to balk based on a natural cost structure and the delays caused by PUs’ interruptions, which can be studied as a non-cooperative game. The equilibrium and optimal strategies of SUs are both derived. Furthermore, to bridge the gap between the individually and socially optimal strategies, a novel strategy of imposing an admission fee on SUs to join the retrial group is proposed. Finally, some numerical examples are presented to show the effect of several key parameters on the system performance.

An unobservable retrial queueing system with complementary services is studied, in which customers are risk neutral and they have no information of the system upon arrival, but have to make the decision to join the system or not to maximize their expected benefits. In our model, one server provides an instantaneous service while the other offers a service with delayed customers, which is modeled as an M/M/1 retrial queue. The two services are complementary and the customer has no benefit from obtaining just one of them. Under various pricing schemes, we investigate the customers' reward-cost situations and the servers' price strategies in equilibrium. In each pricing scheme three scenarios are studied according to the different ownership of the two servers: (1) they are owned and operated by two different private agents; (2) they are owned and operated by a common private agent; or (3) one is owned and operated by a private agent, and the other by a public agent. Some numerical experiments of the equilibrium solutions are presented. (C) 2016 Elsevier Inc. All rights reserved.

Nowadays the distributed heterogeneous resources of networks, like the computational grid, start to have a greater part of interest so, the investigations of such systems are vital.Because of the more efficient utilization of the resources, the job scheduling becomes more challenging for the system administrators.The allocation of the arriving jobs has a great impact on the efficiency and the energy consumption of the system.In this paper, we present a finite source generalized model for the performance evaluation of scheduling computeintensive jobs based on the infinite model of Tien Van Do.The available computers are classified into three groups.This classification is based on two aspects: high performance priority (HP) and energy efficiency priority (EE).We investigate three schemes (separate queue, class queue and common queue) for buffering the jobs in a computational cluster that is built from Commercial Off-The-Shelf (COTS) servers.Our main interest is to calculate performance measures and energy consumption of the system using the different buffering schemes and classifications.

It is an effective approach to enlarge a large-diameter shield tunnel using the Pile-Beam-Arch (PBA) method to construct a metro station, especially when traditional excavation methods cannot be used because of the narrow roads and dense buildings. Based on the structural characteristics of a metro station, FLAC(3D) is used to build a three-dimensional model and to analyse the mechanical performance of structurally critical joints and their effect on the settlement of the ground surface. The critical joints include segment joints, connections between blocks of key segments, connections between longitudinal beams and segments, and connections between primary linings and segments. The results show that the calculated stress in the structure does not exceed the strength during the enlarging process. A control standard for the project is also presented based on a comparison between the results of the numerical simulation and the control reference of a Beijing metro station. The numerical analysis result is used to guide the construction. Based on the in-situ monitoring data, the feasibility of the expansion method is verified, as is the accuracy of the numerical simulation. (C) 2015 Elsevier Ltd. All rights reserved.

We consider the system with no waiting space in which primary customers arrive according to a Poisson process. The arriving customer receives service immediately as the server is idle, otherwise, he will enter a retrial orbit asking for repeated requests. When a negative customer comes, the customer being served is deleted immediately and it also causes the server's breakdown. Whenever the server breaks down, it is sent for repair immediately. If no customer arrives after every service completion, the server selects the first customer of the orbit to serve. The time required to find the first customer is assumed exponentially distributed with a constant rate referred as constant retrial rate. Based on a natural reward-cost structure, we study the equilibrium behavior of the customers and derive the corresponding Nash equilibrium joining strategies and social net benefit maximization problem with respect to the levels of information available to customers upon arrival.

This paper is concerned with the equilibrium balking strategies of customers in a Geo/Geo/1 queue with single working vacation. Instead of completely stopping service, the server works with a small probability during the working vacation period. As soon as no customers exist in the system, the server takes a single vacation. The customers decide for themselves whether to enter the system or balk based on a natural reward-cost structure, the information available about the status of the server, and the queue length on hand upon arrival. We obtain the equilibrium balking strategies in two cases: fully observable and fully unobservable cases, which depend on whether the customers know both the queue length and the state of the server or none of them. Finally, we present several numerical experiments that demonstrate the effect of some parameters on the equilibrium behavior.

Guarantee conditions and external auditing are both key parts of debt contracts. Understanding the relationship between guarantee conditions and external auditing is crucial for the improvement of debt contract efficiency and maximization of enterprise value. With non-listed enterprises in the Chinese bond market from 2008 to 2013 as the study sample, this paper investigates the relationship between different types of guarantee and external auditing. The empirical result indicates that: a related-party guarantee is significantly positively correlated with high-quality external auditing, while a local-government guarantee (in which the guarantor and bond issuer belong to the same local government) is significantly negatively correlated with high-quality external auditing. The research also shows that high-quality external auditing is significantly negatively related to bond issuance cost only if companies use a related-party guarantee. The reason is that a local-government guarantee implies the credit and security of local government, which reduces debt agency conflict and the demand for high-quality external auditing, while a related-party guarantee does not reduce information asymmetry, but increases the credit risk of bonds. This risk can be recognized by investors in the Chinese bond market which is dominated by institutional investors, thus causing stronger demand for high-quality external auditing. The result shows that a guarantee substitutes for external auditing when the guarantee is positive, otherwise external auditing is a supplement to a guarantee.

When evaluating geological strength index(GSI),there are great randomness and fuzziness to confirm the value of its basic elements. As a consequence,it is difficult to accurately measure the impact of each influential factor. The fuzziness of the parameter of rock mass characteristics reflects its inherent uncertainty. The fuzzy mathematics theory provides strong measures to depict these characteristics. This article introduces the number of joint sets(Jn),joint spacing(l) and the integrity coefficient of rock mass(Kv) to describe the structure features of rock mass and introduces large-scale waviness(Jw),small-scale smoothness(Js) and joint altered coefficient(Ja) to describe the conditions of structural planes. Then multifactor fuzzy-synthetical evaluation is applied to the system of GSI. Meanwhile,analytic hierarchy process is adopted in determining the weight of each factor. As a result,the model of fuzzy-synthetical evaluation of GSI is established. Project applications prove that this evaluation method has strong pertinence and high accuracy and it can organically combine geological surveys,experiment data, statistics and expert opinions,so this evaluation method can decrease the subjectivity of researchers′decisions. The method of fuzzy-synthetical evaluation of GSI does provide a new approach to quantizing GSI system.

The section tunnel from Dongfengbeiqiao Station to Futongdong Station of Beijing Metro Line 14was constructed by earth pressure balance shield,and the shield tunnel will be enlarged in small-scale by PBA(Pile-Beam-Arch)method to form small metro station.The critical joints of station structure during the enlarging process have four categories.They are segment joints,blocks connection of key segment,connection between longitudinal beams and segments as well as the joints of main arch primary supports and key segments.According to the structural styles of critical joints,the three-dimensional discontinuous contact model is used to simulate the construction process,and the deformation and internal force of critical joints are studied.The results show that the deformation of segment joints and blocks connection of key segment meets the requirement.The construction process greatly influences the redistribution of structural internal force so some bolts exceed tensile strength.The connection of top longitudinal beam and top segment doesnt slip relatively but separates slightly in the case of symmetrical excavation.The resisting shear bolts of top longitudinal beam exceed tensile strength.The connection of bottom longitudinal beam and bottom segment doesnt slip and separate relatively,and the weld seams of joints of main arch primary supports and key segments meet requirement.Thus the station structure is basically steady in this project,only parts need to be strengthened.