The freight allocation problem with all-units quantity-based discount: A heuristic algorithm

This paper studies a problem encountered by a buying office for one of the largest retail distributors in the world. An important task for the buying office is to plan the distribution of goods from Asia to various destinations across Europe. The goods are transported along shipping lanes by shipping companies, which offer different discount rates depending on the freight quantity. To increase the reliability of transportation, the shipper imposes a quantity limit on each shipping company on each shipping lane. To guarantee a minimum business volume, each shipping company requests a minimum total freight quantity over all lanes if it is contracted. The task involves allocating projected demand of each shipping lane to shipping companies subject to the above conditions such that the total cost is minimized.Existing work on this and related problems employs commercial linear programming software to solve their models. However, since the problem is NP−hard in the strong sense, it is unlikely to be solvable optimally in reasonable time for large cases. Hence, we propose the first heuristic-based algorithm for the problem, which combines a filter-and-fan search scheme with a tabu search mechanism. Experiments on randomly generated test instances show that as the size of the problem increases, our algorithm produces superior solutions in less time compared to a leading mixed-integer programming solver.     

对哈尔滨市依兰县自然与民族历史旅游资源开发利用的综合思考

本文简要介绍了依兰县最有潜力的旅游项目 ,并对依兰县发展旅游业提出了对策和建议。     

唐太宗北巡塞垣纪行诗并未亡佚

唐太宗于贞观二十年 (646年 )曾进行过一次北巡塞垣的边事活动 ,并写有一篇“序其事”的纪行诗。笔者通过考证 ,基本上弄清了这一千余年来尘封不显的历史事件 ,从而显示了唐太宗励精图治、安邦治国的创业精神。     

林鹏侠和她的《西北行》

《西北行》是民国西北开发热潮时期众多西北行记中惟一一本由女性撰写的著作。作者林鹏侠是一位颇具豪侠之气的知识女性,有感于“一·二八事变”后国难当头的时局,在母命之下毅然踏上考察西北之路。其女性视角细腻而犀利,对西北社会问题的记录和分析独到而深刻,不仅起到了让国人了解西北宣传西北的效果,且为后人研究20世纪30年代的西北留下了珍贵的第一手资料。     

论市场社会主义对邓小平南方谈话的佐证

20世纪90年代,世界社会主义运动遭受重大挫折,我国的社会主义改革也步入关键时期,邓小平的南方谈话及时回答了苏东剧变所带来的理论困惑和改革中遇到的一些重大问题,进一步厘清和指明了我国社会主义改革的方向。南方谈话的论断经过实践检验是正确的,而且在世界范围内,西方的市场社会主义也从理论上佐证了其科学性:市场是实现社会主义目的的手段,私有制经济是社会主义经济的重要组成部分,共同富裕是社会主义市场经济的旨归,社会主义社会仍然值得期待等。     

Simulation-Based Inspection Policies for a One-Shot System in Storage Over a Finite Time Span

In this paper, we consider an inspection policy problem for a one-shot system with two types of units over a finite time span and want to determine inspection intervals optimally with given replacement points of Type 2 units. The interval availability and life cycle cost are used as optimization criteria and estimated by simulation. Two optimization models are proposed to find the optimal inspection intervals for the exponential and general distributions. A heuristic method and a genetic algorithm are proposed to find the near-optimal inspection intervals, to satisfy the target interval availability and minimize the life-cycle cost. We study numerical examples to compare the heuristic method with the genetic algorithm and investigate the effect of model parameters to the optimal solutions.     

Randomized heuristic algorithms for orthogonal projection of a point onto a set

Abstract

The problem of orthogonal projection of a point onto a set is an essential problem of computational geometry. This problem has many practical applications in different areas such as robotics, computer graphics and so on. In the present paper three algorithms for solving this problem are proposed. This algorithms are based on the idea of heuristic random search. Numerical experiments illustrating the work of the proposed methods are presented.     

A heuristic to minimize total flow time in permutation flow shop

In this paper, we address an n-job, m-machine permutation flow shop scheduling problem for the objective of minimizing the total flow time. We propose a modification of the best-known method of Framinan and Leisten [An efficient constructive heuristic for flowtime minimization in permutation flow shops. Omega 2003;31:311–7] for this problem. We show, through computational experimentation, that this modification significantly improves its performance while not affecting its time-complexity.     

“产婆术”新解

关注青年大学生的健康成长,是大学教育出发点与最终归宿.笔者就自己从事大学英语教学的实践经验出发,分析了"产婆术"这种历久弥新的教育思想.在教学中,我们对传统的"注入武"教学加以摒弃,恰当运用现代"产婆术"(启发性教学)对学生进行"启发"教育,以求得"产婆术"真正的新解.     

旅游中零负团费的法律规制

文章运用案例分析、规范分析、政策价值的研究方法,研究了旅游中零负团费表现的隐性化、更不易于法律适用这一现象的法律制度成因。法学零负团费本质是旅游服务合同中约定的服务价格等于或低于旅游服务成本,旅行社在旅游服务合同履行过程中,通过各种隐性形式收取回扣来弥补损失的非正常盈利模式。零负团费损害了旅游消费者的公平交易权益和对旅游产品的选择权,破坏了旅游市场秩序。现行法律制度下,对零负团费的规制有其制度困境,主要在于《旅游法》中认定标准不明确,表现在《旅游法》的第35条明确禁止了零负团费情形,但是实效却不太理想,主要是因为对“不合理低价”、诱骗、强迫、“具体购物场所”范围等认定不清。对于规制旅游中零负团费,建议可以从完善立法、加强监管、自律和他律方面入手,建立起综合协调机制。