The Accuracy and Thoroughness of a Federated Search Engine in the Health Sciences

SUMMARY

Research studies show that researchers need to access multiple resources to ensure a comprehensive search. In the health care field, health professionals' time is very limited, and they would benefit from being able to access multiple resources simultaneously. Health professionals must retrieve the most relevant and accurate information possible when applying clinical information to patient care. While a federated search engine may offer speedy search capabilities, do they offer the same accuracy and relevancy as directly searching the core health sciences databases? The purpose of this study is to describe, evaluate, and compare searching health sciences topics using a federated search engine versus searching five core health sciences databases directly. The following databases were selected for this study: WebFeat (federated search engine), MEDLINE, CINAHL, Science Citation Index, Biological Abstracts, and EMBASE. While WebFeat is convenient for searching multiple databases simultaneously, it does not offer the advanced search limits offered by directly searching some of the health sciences databases. The lack of limits available in the federated search engine means increased results that may not be relevant to the busy health care professional.     

Exploring the fitness landscape and the run-time behaviour of an iterated local search algorithm for cost-based abduction

Cost-based abduction (CBA) is an important problem in reasoning under uncertainty, and can be considered a generalization of belief revision. CBA is known to be NP-hard and has been a subject of considerable research over the past decade. In this paper, we investigate the fitness landscape for CBA, by looking at fitness–distance correlation for local minima and at landscape ruggedness. Our results indicate that stochastic local search techniques would be promising on this problem. We go on to present an iterated local search algorithm based on hill-climbing, tabu search, and simulated annealing. We compare the performance of our algorithm to simulated annealing, and to Santos' integer linear programming method for CBA.     

Accelerating search in function induction

Abstract

Inducing functions from examples is an important requirement in many learning systems. Blind search is the most general approach, but is vastly less efficient than specialized problem-solving methods. This paper presents a new strategy to accelerate search without sacrificing generality. Experiments with numeric functions show several orders of magnitude performance increase over the standard search technique. Two factors account for this improvement. First, the new strategy manipulates functions in groups instead of singly, so that many can be selected or discarded with only one comparison. Second, functional equivalence is handled automatically by the internal organization of search space.     

A multiobjective hybrid ant colony optimization approach applied to the assignment and scheduling problem

The assignment and scheduling problem is inherently multiobjective. It generally involves multiple conflicting objectives and large and highly complex search spaces. The problem allows the determination of an efficient allocation of a set of limited and shared resources to perform tasks, and an efficient arrangement scheme of a set of tasks over time, while fulfilling spatiotemporal constraints. The main objective is to minimize the project makespan as well as the total cost. Finding a good approximation set is the result of trade‐offs between diversity of solutions and convergence toward the Pareto‐optimal front. It is difficult to achieve such a balance with NP‐hard problems. In this respect, and in order to efficiently explore the search space, a hybrid bidirectional ant‐based approach is proposed in this paper, which is an improvement of a bi‐colony ant‐based approach. Its main characteristic is that it combines a solution construction developed for a more complicated problem with a Pareto‐guided local search engine.     

一种多策略改进的麻雀搜索算法

针对麻雀搜索算法在求解复杂优化问题时存在收敛速度慢、种群趋同性严重、易于陷入局部最优等不足,提出一种多策略改进的麻雀搜索算法（multi-strategy improved sparrow search algorithm,MISSA）。通过混沌映射和反向学习机制提高算法初始种群的质量;借鉴粒子群算法的学习策略来提升种群的信息交流能力和兼顾全局勘探与局部开发之间的平衡;融合差分进化算法的变异交叉操作提升算法跳出局部最优值的能力。通过对8个基准测试函数的寻优实验,结果表明改进算法具有更好的优化性能和收敛效率;进一步地,将改进算法应用于优化支持向量回归（support vector regression,SVR）模型的参数,并通过在选定的5个UCI数据集上的实验验证了改进算法的有效性。     

Enhanced user performance in an image gallery application with a mobile autostereoscopic touch display

In this study, we explored how stereoscopic depth affects performance and user experience in a mobile device with an autostereoscopic touch display. Participants conducted a visual search task with an image gallery application on three layouts with different depth ranges. The task completion times were recorded, and the participants were asked to rate their experiences. The results revealed that the image search times were facilitated by a mild depth effect and that too great a depth slowed search times and decreased user-experience ratings.     

单调矩阵搜索算法设计与应用

本文提出了单调矩阵搜索问题一个统一的算法框架和实现策略，使得可在线性时间内求得矩阵搜索问题的解，并将此算法框架应用于设计凸多边形所有顶点最远邻点问题的高效算法。     

一种十字形运动搜索算法

近几年,虽然运动估计算法有了很多种的快速算法,但是,运动搜索巨大的计算量依然是视频压缩速率的瓶颈,本文针对运动矢量的分布特点,提出了一种新的运动搜索算法,算法不仅结构简单,而且测试结果表明,该算法比原有DS9(dia-mondsearch)算法在搜索点数和图像质量方面有较大的提高,最好时的搜索点数只有DS算法的3/4。     

Reducing conflict resolution time for solving graph problems in broadcast communications

In this paper, we propose some algorithms to solve the topological ordering problem, the breadth-first search problem and the connected component problem under the broadcast communication model. The basic idea of our algorithms is to divide a graph into several layers. Only after all vertices in one layer are processed, we begin to process the vertices in another layer. Thus, the number of broadcast conflicts is reduced. We also propose a randomized conflict resolution scheme to resolve conflicts. We show that the average time complexity of our algorithms is Θ(n), where n is the number of available processors and also the number of vertices in the graph.