Queueing models for full-flexible multi-class call centers with real-time anticipated delays

In this paper, we consider two basic multi-class call center models, with and without reneging. Customer classes have different priorities. The content of different types of calls is assumed to be similar allowing their service times to be identical. We study the problem of announcing delays to customers upon their arrival. For the simplest model without reneging, we give a method to estimate virtual delays that is used within the announcement step. For the second model, we first build the call center model incorporating reneging. The model takes into account the change in customer behavior that may occur when delay information is communicated to them. In particular, it is assumed that customer reneging is replaced by balking that depends on the state of the system in this case. We develop a method based on Markov chains in order to estimate virtual delays of new arrivals for this model. Finally, some practical issues concerning delay announcement are discussed.     

软交换技术在呼叫中心系统中的应用

世纪之交,我国实施的西部大开发,为改革开放和社会主义现代化建设做出了巨大的理论贡献。开发西部,是毛泽东“合理布局”思想的继承和发展,是邓小平“两个大局”思想的进一步深化,是江泽民“三个代表”思想的具体体现,是可持续发展战略的必然要求,是区域经济协调发展的战略选择,同时,也是社会主义市场经济发展的必然要求。     

搭建数字化校园的CT接口

信息时代的到来，不仅改变着人们的生产方式和生活方式，而且改变着人们思维方式和学习方式，这是对教育的严峻挑战，也为教育的改革和发展提供了千载难逢的机遇，使得数字化校园在国内外快速发展。但是，现代电信技术和计算机技术的高速发展，使得数字化校园原有的技术接口已经不再满足需求。CT接口将传统的电话语音网络发展成为用户获得各种信息的接人手段，成为数字化校园的重要组成接口之一。从数字化校园的发展、接口组成，CT接口的由来、优势和设计实现等方面，对搭建数字化校园的CT接口进行了详细的阐述。     

大规模通信网络带宽分配的快速分解优化

本文对大规模通信网络带宽分配的计算过程进行了研究，发现现有分解优化计算的方法中限制计算速度的瓶颈在于主节点上的等效流量的计算，在此基础上提出一种用近似公式代替递推公式计算呼叫损失概率的方法，将它运用于带宽分配算法中，计算速度大力提高，而计算相对误差为10％左右。     

Closing call auctions and liquidity

The present paper examines the impact of closing call auctions on liquidity. It exploits the natural experiment offered by the introduction of a closing call auction on the Australian Stock Exchange on 10 February 1997. The introduction of the closing call auction is associated with a reduction in trading volume at the close of continuous trading. However, bid‐ask spreads during continuous trading are largely unaffected by the introduction of the closing call auction. Therefore, closing call auctions consolidate liquidity at a single point in time without having any adverse effect on the cost of trading.     

The impact of offshored and outsourced call service centers on customer appraisals

Firms are increasingly relying upon offshored and/or outsourced call centers to provide post-sales assistance to their customers. Although the motivation to engage in these practices is efficiency gains, the possibility exists that offshored and outsourced call centers may have a detrimental impact on customer appraisals. The aim of this research is to posit the conceptual reasons as to why differences may arise in customer evaluations from these practices. To this end, we rely on the homophily principle and hybrid organization theory to provide conceptual grounding, and utilize a company dataset of customer post-call evaluations to offer an initial test of the hypotheses.

期权定价理论在高科技企业权益资本价值评估中的应用

在经济发展过程中,企业价值评估逐渐成为企业财务管理的一项经常性工作。企业价值评估结果的准确性直接影响着企业的未来经营情况,近年来期权定价理论在西方金融领域比较盛行,本文把这一理论引入到高科技企业的权益价值评估中来,为高科技企业的价值评估提供了一种新的思路。     

The buyers’ perspective on security design: Hedge funds and convertible bond call provisions

We provide evidence that security design reflects the interplay of capital supplier and security issuer preferences. While call provisions have historically been the default option in convertible security design, only a minority of post-2005 issues are callable. Because hedge funds dominate the market for new convertibles today and because convertible arbitrage is less risky without callability, the recent diminution in the frequency of call provisions in new convertible bond issues illustrates the importance of the preferences of the suppliers of capital in security design.     

Modeling mobile health service delivery to Syrian migrant farm workers using call record data

A significant number of Syrian refugees under temporary protection in Turkey work in agriculture seasonally in various rural areas during several months a year. These migrant farm workers and their families are deprived of access to the regular health care system and preventive services due to their remote locations. The government supports the delivery of different types of mobile health care services, such as vaccination for children, reproductive health and screening services. While planning the mobile health care service delivery, it is critical to know where the refugees will work during what time frame; hence the demand for the services. By analyzing the call record data of a major mobile network operator in Turkey, we quantify the increase in the volume of calls made by Syrian refugees in various agricultural areas during the harvesting season of local crops. This information helps us to forecast spatial and temporal distribution of demand for mobile health care services at a fine granularity. Taking demand over multiple periods as input into a mathematical programming model, we optimize the routing of mobile clinics that visit locations close to where refugees are concentrated over the given planning horizon. We consider three hierarchical objectives. Given the availability of a number of mobile clinics at community health centers in the districts, the first objective aims to maximize the percentage of refugees that can benefit from each service type within pre-defined close distances. The second objective minimizes the number of clinics needed while covering the maximum percentage of refugees. The third objective minimizes the total travel distance of the clinics, while keeping the maximum coverage level using a minimum number of clinics to achieve this level. We quantify the benefits of centralized planning (by the province directorate) over decentralized planning (by each district separately). We also show the trade-off between the required number of clinics and coverage of potential patients.     

Clearing price distributions in call auctions

We propose a model for price formation in financial markets based on the clearing of a standard call auction with random orders, and verify its validity for prediction of the daily closing price distribution statistically. The model considers random buy and sell orders, placed employing demand- and supply-side valuation distributions; an equilibrium equation then leads to a distribution for clearing price and transacted volume. Bid and ask volumes are left as free parameters, permitting possibly heavy-tailed or very skewed order flow conditions. In highly liquid auctions, the clearing price distribution converges to an asymptotically normal central limit, with mean and variance in terms of supply/demand-valuation distributions and order flow imbalance. By means of simulations, we illustrate the influence of variations in order flow and valuation distributions on price/volume, noting a distinction between high- and low-volume auction price variance. To verify the validity of the model statistically, we predict a year's worth of daily closing price distributions for five constituents of the Eurostoxx 50 index; Kolmogorov–Smirnov statistics and QQ-plots demonstrate with ample statistical significance that the model predicts closing price distributions accurately, and compares favourably with alternative methods of prediction.