How Users Search the Mobile Web:A Model for Understanding the Impact of Motivation and Context on Search Behaviors

Purpose： This study explores how search motivation and context influence mobile Web search behaviors. Design/methodology/approach： We studied 30 experienced mobile Web users via questionnaires, semi-structured interviews, and an online diary tool that participants used to record their daily search activities. SQLite Developer was used to extract data from the users＇ phone logs for correlation analysis in Statistical Product and Service Solutions （SPSS）. Findings： One quarter of mobile search sessions were driven by two or more search motivations. It was especially difficult to distinguish curiosity from time killing in particular user reporting. Multi-dimensional contexts and motivations influenced mobile search behaviors, and among the context dimensions, gender, place, activities they engaged in while searching, task importance, portal, and interpersonal relations （whether accompanied or alone when searching） correlated with each other. Research limitations： The sample was comprised entirely of college students, so our findings may not generalize to other populations. More participants and longer experimental duration will improve the accuracy and objectivity of the research. Practical implications： Motivation analysis and search context recognition can help mobile service providers design applications and services for particular mobile contexts and usages. Originality/value： Most current research focuses on specific contexts, such as studies on place, or other contextual influences on mobile search, and lacks a systematic analysis of mobile search context. Based on analysis of the impact of mobile search motivations and search context on search behaviors, we built a multi-dimensional model of mobile search behaviors.

Key Technologies in Mobile Visual Search and MPEG Standardization Activities

Visual search has been a long-standing problem in applications such as location recognition and product search. Much research has been done on image representation, matching, indexing, and retrieval. Key component technologies for visual search have been developed, and numerous real-world applications are emerging. To ensure application interoperability, the Moving Picture Experts Group （MPEG） has begun standardizing visuaJ search technologies and is developing the compact descriptors for visua） search （CDVS） standard. MPEG seeks to develop a collaborative platform for evaluating existing visual search technologies. Peking University has participated in this standardization since the 94th MPEG meeting, and significant progress has been made with the various proposals. A test model （TM） has been selected to determine the basic pipeline and key components of visual search. However, the first-version TM has high computational complexity and imperfect retrieval and matching. Core experiments have therefore been set up to improve TM. In this article, we summarize key technologies for visual search and report the progress of MPEG CDVS. We discuss Peking University＇ s efforts in CDVS and also discuss unresolved issues.

Similar physical entity matching strategy for mobile edge search

In recent years,a large number of intelligent sensing devices have been deployed in the physical world,which brings great difficulties to the existing entity search.With the increase of the number of intelligent sensing devices,the accuracy of the search system in querying the entities to match the user’s request is reduced,and the delay of entity search is increased.We use the mobile edge technology to alleviate this problem by processing user requests on the edge side and propose a similar physical entity matching strategy for the mobile edge search.First,the raw data collected by the sensor is lightly weighted and expressed to reduce the storage overhead of the observed data.Furthermore,a physical entity matching degree estimation method is proposed,in which the similarity between the sensor and the given sensor in the network is estimated,and the matching search of the user request is performed according to the similarity.Simulation results show that the proposed method can effectively reduce the data storage overhead and improve the precision of the sensor search system.

ALGORITHM AND IMPLEMENTATION OF AUTO-SEARCHING WELD LINE FOR WELDING MOBILE ROBOT

An algorithm of auto-searching weld line for welding mobile robot is presented. Auto-searching weld line is that the robot can automatically recognize a weld groove according to the characteristics of the weld groove before welding, and then adjust itself posture to the desired status preparing for welding, namely, it is a process that the robot autonomously aligns itself to the center of welding seam. Firstly, the configuration of welding mobile robot with the function of auto-searching weld line is introduced, then the algorithm and implementation of auto-searching weld line are presented on the basis of kinematics model of the robot, at last trajectory planning among auto-searching weld line is investigated in detail. The experiment result shows that the developed welding mobile robot can successfully implement the task of auto-searching weld line before welding, tracking error precision can be controlled to approximate ±1.5 mm, and satisfy the requirement of practical welding project.

Analytical Comparison of Resource Search Algorithms in Non-DHT Mobile Peer-to-Peer Networks

One of the key challenges in ad-hoc networks is the resource discovery problem.How efciently&quickly the queried resource/object can be resolved in such a highly dynamic self-evolving network is the underlying question?Broadcasting is a basic technique in the Mobile Ad-hoc Networks(MANETs),and it refers to sending a packet from one node to every other node within the transmission range.Flooding is a type of broadcast where the received packet is retransmitted once by every node.The naive ooding technique oods the network with query messages,while the random walk scheme operates by contacting subsets of each node’s neighbors at every step,thereby restricting the search space.Many earlier works have mainly focused on the simulation-based analysis of ooding technique,and its variants,in a wired network scenario.Although,there have been some empirical studies in peer-to-peer(P2P)networks,the analytical results are still lacking,especially in the context of mobile P2P networks.In this article,we mathematically model different widely used existing search techniques,and compare with the proposed improved random walk method,a simple lightweight approach suitable for the non-DHT architecture.We provide analytical expressions to measure the performance of the different ooding-based search techniques,and our proposed technique.We analytically derive 3 relevant key performance measures,i.e.,the avg.number of steps needed to nd a resource,the probability of locating a resource,and the avg.number of messages generated during the entire search process.

Development of Search System Used for Material Processing by Mobile Internet

A wireless search system was integrated on Windows 2000 server.Based on the communication principle between wireless data and Internet,the object expression of search file,the automatic query of document information,the segment browsing of result information,and the receiving and sending of user information were realized by using Active Server Page 3.0,VB Script,WML Script insert languages and object orient database technology.The requirement querying information of material processing through Internet by GPRS,WAP mobile handset and so on was accomplished.

A Case for Cloud-Based Mobile Search

Mobile search is beset with problems because of mobile terminal constraints and also because its characteristics are different from the traditional Internet search model. This paper analyzes cloud computing technologies--especially mass data storage, parallel computing, and virtualization--in an attempt to solve technical problems in mobile search. The broad prospects of cloud computing are also discussed.

Study on intelligent welding mobile robot with the function of auto-searching weld line

The development of welding robots suitable for specially unstructured working enviroments has been become an important development direction of industrial robot application because large-scale welding structures have been used more and more widely in modern industry. In this paper, an intelligent mobile robot for welding of ship deck with the function of autosearching weld line was presented. A wheeled motion mechanism and a cross adjustment slider are used for the welding robot body. A sensing system based on laser-PSD （position sensitive detector） displacement sensor was developed to obtain two dimensional deviation signals during seam tracking. A full-digital control system based on DSP and CPLD has also been realized to implement complex and high-performance control algorithms. Furthermore, the system has still the function of auto-searching weld line according to the characteristics information of weld groove and adjusting posture itself to the desired status preparing for welding. The experiment of auto-searching welding line shows that the robot has high tracing accuracy, and can satisfy the requirement of practical welding project.

基于Mobile Agent的搜索引擎关键技术研究

论述了如何将Ｍｏｂｉｌｅ Ａｇｅｎｄｅ术应用到搜索引擎中，并针对基于Ｍｏｂｉｌｅ Ａｇｅｎｔ的新型搜索引擎的关键技术，进行了深入的研究，提出一些解决方案，包括Ｍｏｂｉｌｅ Ａｇｅｎｔ的智能路由、智能克隆、基于文档价值的搜索等。同时把这些关键技术应用到基于Ｍｏｂｉｌｅ Ａｇｅｎｔ的搜索引擎Ｆｉｎｄｅｒ的实现中。最后介绍了Ｆｉｎｄｅｒ的体系结构和工作流程，展现了新一代搜索引擎的架构。

局域网中利用MobileAgent技术实现信息的检索

提出了一个应用于局域网中的基于MobileAgent技术的信息检索系统的模型 ,并给出了实现该系统的关键技术。整个模型是建立在已有网络协议的基础上 ,并且采用了概念分层结构。关键技术涉及Agent的基本结构、Agent的管理和通信。

基于Mobile Agent技术的搜索引擎IRAS

介绍了基于Mobile Agent的软件技术,利用该技术设计了一个搜索引擎IRAS,描述了其设计思想、组成和工作流程。此外,通过与传统Robot搜索方式进行对比,分析了IRAS搜索引擎系统的性能优势。

基于Mobile Agent的信息搜索技术

本文在分析传统搜索引擎弱点的基础上,将Mobile Agent技术引入信息搜索领域,以期实现搜索的高精度、高速度、低开销以及智能化.给出了基于Mobile Agent的信息搜索系统模型-ISSMA,详细介绍了它的组成、功能及关键技术.

Mobile Agent技术在局域网中的信息检索的实现

论述了一个应用于局域网中的基于Mobile Agent技术的信息检索系统的模型结构和关键技术的实现方法。整个 模型是建立在已有网络协议的基础上并且采用了分层结构,共分为四层:网络层、平台层、代理层、应用层。关键技术涉及 Agent的基本结构、Agent的管理和通信、Agent的回调生成算法和安全问题。

Mobile Agent及其在Internet中的应用

移动Agent技术已成为计算机网络和分布式系统最具活力的发展方向 ,文中对移动Agent的概念、移动Agent的特点、用移动Agent实现Internet信息搜索与传统技术的比较、实现移动Agent面临的技术障碍与社会障碍及移动Agent的应用等方面内容进行了讨论。

Web搜索引擎中Mobile Agent动态路由问题研究

随着Internet的发展,Web上大量、分布、动态的信息导致了"信息过载",传统搜索引擎面临严峻的挑战。目前对MobileAgent系统的理论与应用研究已成为一个热点前沿课题。本文对Web搜索引擎中MobileAgent动态路由问题进行了研究。

Path Planning of the Multiple Mobile Robot System Applied in Chinese Chess Game

The article presents the path planning algorithm to be applied in the Chinese chess game, and uses multiple mobile robots to present the experimental scenario. Users play the Chinese chess game using the mouse on the supervised computer. The supervised computer programs the motion paths using A＊ searching algorithm, and controls mobile robots moving on the grid based chessboard platform via wireless radio frequency （RF） interface. The A＊ searching algorithm solves shortest path problems of mobile robots from the start point to the target point, and avoids the obstacles on the chessboard platform. The supervised computer calculates the total time to play the game, and computes the residual time to play chess in the step for each player. The simulation results can fired out the shortest motion paths of the mobile robots （chesses） moving to target points from start points in the monitor, and decides the motion path to be existence or not. The eaten chess can moves to the assigned position, and uses the A＊ searching algorithm to program the motion path, too. Finally, the authors implement the simulation results on the chessboard platform using mobile robots. Users can play the Chinese chess game on the supervised computer according to the Chinese chess game rule, and play each step of the game in the assigned time. The supervised computer can suggests which player don＇t obey the rules of the game, and decides which player to be a winner. The scenario of the Chinese chess game feedback to the user interface using the image system.

Video Image Block-matching Motion Estimation Algorithm Based on Two-step Search

Aiming at the shortcoming that certain existing blockingmatching algorithrns, such as full search, three-step search, and dia- mond search algorithms, usually can not keep a good balance between high acoaracy and low computational complexity, a block-maching motion estimation algorithm based on two-step search is proposed in this paper. According to the fact that the gray values of adjacent pixels will not vary fast, the algorithm employs an interlaced search pattem in the search window to estimate the motion vector of the objectblock. Simulation and actual experiments demanstrate that the proposed algmithm greatly outperforms the well-known three-step search and dianond search algoritlam, no matter the motion vector is large or small. Comparedc with the full search algorithm, the proposed one achieves similar peffomance but requires much less computation, therefore, the algorithm is well qualified for real-time video image processing.

Optimal Stop Points for Data Gathering in Sensor Networks with Mobile Sinks

Given a wireless sensor network (WSN) in which a mobile sink is used to collect data from the sensor nodes, this paper addresses the problem of selecting a set of stop points that results in low energy usage by the sensor nodes. This paper assumes an approach in which a mobile sink travels along a fixed path and uses a stop-and-collect protocol since this has previously been shown to be an efficient WSN data collection method. The problem of selecting an optimal set of stop points is shown to be an NP-hard problem. Then, an Integer Linear Programming (ILP) formulation is used to derive an optimal algorithm that can be used for small problem instances. Next, a polynomial-time Tabu-search-based heuristic algorithm is proposed. Simulations are used to compare the energy consumption values, computation times and expected network lifetimes when using the optimal ILP algorithm, the proposed heuristic algorithm and several other possible heuristic algorithms. The results show that the proposed heuristic algorithm results in near-optimal energy usage values with low computation times, thereby making it suitable for large-sized WSNs.

基于改进两步移动搜索法的南京市养老机构空间可达性研究

空间可达性是评价一个城市养老服务设施配置科学性的关键指标之一,精准衡量城市养老机构的空间异质性、合理规划养老公共空间,是实现城市稳定健康发展的重要保障。以南京市为例,基于多源数据构建随机森林模型将南京市2022年常住人口格网化,结合改进的两步移动搜索法进行养老服务设施的可达性分级测算,通过构建养老机构空间自相关探究其空间分异特征。结果表明:南京市养老机构空间可达性整体较好,但区域配置差异明显;主城区和副中心城区的可达性高,城乡结合部和边缘农村区域可达性较差。

基于自适应启发函数和逆向寻优策略的改进A^(*)移动机器人路径规划算法

移动机器人大多数情况都是在室外和室内障碍物环境下进行移动;因此,在这些障碍物环境中,高效率、短路径和少转折点的路径规划算法对移动机器人导航至关重要;针对在室外和室内障碍物环境下A^(*)算法无法同时保持高效率、短路径和少转折点的问题,提出了一种基于自适应启发函数和逆向寻优策略的改进A^(*)算法;通过增加自适应权重系数、引入父节点的影响力并对搜索方向进行筛选,减少了搜索面积,提高了搜索效率;采用逆向寻优策略对路径进行进一步优化,缩短了路径长度,减少了转折点数量;为了评估改进A^(*)算法的性能,在仿真实验中设置常见的室外和室内障碍物环境并与A^(*)算法对比;仿真实验结果表明,改进A^(*)算法在效率、路径长度和转折点数量方面具有显著优势,能够有效地应用于移动机器人的导航中。