Comparison of agent-based scheduling to look-ahead heuristics for real-time transportation problems

We consider the real-time scheduling of full truckload transportation orders with time windows that arrive during schedule execution. Because a fast scheduling method is required, look-ahead heuristics are traditionally used to solve these kinds of problems. As an alternative, we introduce an agent-based approach where intelligent vehicle agents schedule their own routes. They interact with job agents, who strive for minimum transportation costs, using a Vickrey auction for each incoming order. This approach offers several advantages: it is fast, requires relatively little information and facilitates easy schedule adjustments in reaction to information updates. We compare the agent-based approach to more traditional hierarchical heuristics in an extensive simulation experiment. We find that a properly designed multi-agent approach performs as good as or even better than traditional methods. Particularly, the multi-agent approach yields less empty miles and a more stable service level.     

基于树型结构的采购组合拍卖获胜概率计算方法研究

在基于树型结构的采购组合拍卖模型的研究基础上,建立了这一类采购组合拍卖的投标获胜概率的数学模型,给出了投标获胜概率的求解方法.通过算例,详细分析了具体计算方法的规律性和可行性.投标获胜概率的计算方法本身具有重要意义,同时能够为投标者提供决策依据和行为参考;也为进一步研究采购组合拍卖的投标期望收益、均衡策略和机制设计奠定了必要的理论基础.     

Robust strategic bidding in auction-based markets

In this paper, we propose an alternative methodology for devising revenue-maximizing strategic bids under uncertainty in the competitors’ bidding strategy. We focus on markets endowed with a sealed-bid uniform-price auction with multiple divisible products. On recognizing that the bids of competitors may deviate from equilibrium and are of difficult statistical characterization, we proposed a two-stage robust optimization model with equilibrium constraints aiming to devise risk-averse strategic bids. The proposed model is a trilevel optimization problem that can be recast as a particular instance of a bilevel program with equilibrium constraints. Reformulation procedures are proposed to find a single-level equivalent formulation suitable for column-and-constraint generation (CCG) algorithm. Results show that even for the case in which an imprecision of 1% is observed on the rivals’ bids in the equilibrium point, the robust solution provides a significant risk reduction (of 79.9%) in out-of-sample tests. They also indicate that the best strategy against high levels of uncertainty on competitors’ bid approaches to a price-taker offer, i.e., bid maximum capacity at marginal cost.     

最低价评标法若干问题探析

从我国建设工程招投标评标方法入手，论述了最低价评标法的优缺点，分析了应用最低价评标法应把握几个问题，最后提出了实际最低价评标法的几项保障措施。     

基于多Agent的车间任务招投标粗模糊集建模研究

首先通过相识集、招标集、投标集和任务集的概念 ,描述制造执行系统中的调度 Agent与资源 A-gent间任务招投标过程模型 ;基于任务的属性和资源 Agent完成任务的成本、质量、负荷和时间等属性 ,定义论域上的模糊集 ,将模糊集中的隶属度函数作为粗集的属性 ,在模糊集上作截集 ,从而获得系统的分类知识 ;收集样本数据 ,构造并分析决策表 ,进而获得调度 Agent调度决策知识 ;应用调度知识进行推理 ,从争取获得招标任务的若干个资源 Agent中 ,选出最适合招标任务的中标者 .     

网络竞价系统中负载均衡技术优化

在网络系统正常运行中,如何确保数据准确实时高效的传输变得越来越重要,在一些高并发、高吞吐的服务中,确保每个事务功能正常运转越来越重要;系统的负载是否均衡是确保整个系统能否完整工作的关键,现在有很多负载均衡算法旨在使得每个服务器的负载趋于相等,可以归纳为静态均衡方法和动态均衡方法;考虑到影响服务器的负载有多重因数,结合贪心算法作出相对合理的负载均衡策略,应用到本次竞价系统中对比以前的平衡策略,通过比较可以得出多衡量指标的综合考虑会提高负载均衡的性能,对网络竞价系统能够起到更优化的作用。     

On bidding for a fixed number of items in a sequence of auctions

We consider the problem of a firm (“the buyer”) that must acquire a fixed number (L) of items. The buyer can acquire these items either at a fixed buy-it-now price in the open market or by participating in a sequence of N > L auctions. The objective of the buyer is to minimize his expected total cost for acquiring all L items. We model this problem as a Markov Decision Process and establish monotonicity properties for the optimal value function and the optimal bidding strategies.     

未确知有理数在投标方案择优中的应用

评标是工程项目招投标的中心环节,许多评价因素易于定性分析而难于定量分析.根据评标中的主要评价因素,建立起量化评价指标体系,以各量化指标为变量,根据评标实践条件,构建出考虑招标单位相对收益的评标择优决策模型,利用未确知有理数理论,给出对投标方案的综合情况进行量化并进行选择的一个数学模型方法.     

基于Fuzzy-Rough-TOPSIS的工程项目投标风险评价模型研究

在工程项目招投标阶段,项目风险评价是建筑施工企业进行投标决策和作出项目选择的重要依据.基于理想化与主客观相结合的思想,提出了一种确定风险评价指标综合权重的方法;采用梯形模糊数处理模糊性信息,并将其与粗集理论和TOPSIS(a technique for order preference by similarity to ideal solution)方法相融合,建立了工程项目风险评价的Fuzzy-Rough-TOPSIS模型.实例运行表明,模型可操作性强,适用于多个项目的风险分析和比较,并能够在一定程度上克服以往模型存在的主观性强、应用条件限制严格等不足.     

工程招投标中的激励机制分析

本文试图利用博弈理论 ,对工程招投标过程中存在的现象进行分析 ,并建立了相应的对策模型 .目的是通过所建模型讨论工程招投标过程中招投标双方的对策及博弈 ,力图达到一种均衡