移动自组织网络中基于QoE的跨层多波束信道接入机制

引入数字多波束技术可以使移动自组织网络的信道容量得到有效提升，然而，时间、频率、空间、用户、功率等多维度资源域的统一调度与跨层联合优化使得信道接入机制的分析与设计变得更加复杂。为此，结合多波束的特性，将波束宽度限制、收发限制、通道限制、功率限制等多种约束条件抽象图论问题，并建立分析模型。基于分析模型，进一步提出了MB-MAC（Multi-beam Medium Access Control）信道接入机制，结合物理层的预编码技术，建立定向链路的队列模型，度量用户的满意度(Quality of Experience,QoE)，设计了适用于自组织网络中多用户并发并收的信道接入机制，兼顾了网络容量和用户满意度。仿真结果表明，MB-MAC机制能在保证各个用户满意度的情况下，有效提升网络吞吐率。     

Updates management in mobile applications: iTunes versus Google Play

This paper focuses on a specific strategy that developers of mobile applications may use to stimulate demand: The release of updates. We develop a theoretical analysis that shows that developers have incentives to release updates when experiencing a drop in performance. The predictions of the model are then tested using an unbalanced panel of top 1,000 apps in iTunes and Google Play for five European countries. We estimate that while in iTunes the release of an update stimulates a 26% increase in download growth, in Google Play updates play a less significant role. This difference is partly due to systematic differences in apps and in developers operating in the two stores (“selection effect”), and partly to a lack of quality control on apps and updates in Google Play (“quality check effect”). These findings highlight the crucial importance of an appropriate management of updates as well as the relevance of institutional characteristics of the app stores.     

Following the story: narrative mapping as a mobile method for tracking and interrogating spatial narratives

Museums and heritage tourism sites are highly curated places of memory work whose function is the assembling and ordering of space and narrative to contour visitors’ experiences of the past. Variations in such experiences within and between sites, however, necessitates a method that: (1) captures how guides, visitors, and exhibits interact within spaces when representing and performing history and (2) allows researchers to document those variations. We developed narrative mapping, a mobile and geographically sensitive form of participant observation, to enable museum scholars and professionals to systematically capture, visualize, and interpret tendencies and variations in the content, affective qualities, and spatial arrangements of museum narratives over multiple sites and across multiple tours at the same site. Two antebellum plantation museum case studies, Laura Plantation in Louisiana and Virginia’s Berkeley Plantation, demonstrate the method’s utility in documenting how stories are spatially configured and materially enlivened in order to analyze the ways enslaved persons are placed within these narratives.     

Accessing leisure in an unfamiliar society via mobile instant messaging: A case study of academic sojourners visiting South Korea

ABSTRACT

This paper explores how academic sojourners, unfamiliar with the local language and culture, accessed casual leisure through mobile instant messaging during a short stay of one or two semesters in South Korea. Ninety-six English-speaking academic sojourners on Korean government scholarships covering tuition, room and board in exchange for contact with local university students seeking informal English language practice took part in this study. They represent a shift in academic sojourner mobility from outbound Asian students seeking language study in English-speaking countries to inbound English-speakers providing language support within Asia. Qualitative analysis revealed how casual leisure, the features of South Korea’s advanced digital environment and mobile instant messaging chat rooms coalesced. The findings show how local digital practices complement casual leisure access and how digital practices can become casual leisure despite limits in language ability and cultural understanding. It recommends further exploration of links between leisure, digital environments and mobile instant messaging in other research settings that are experiencing flows of globally mobile populations.     

基于同轴电缆的移动信号室内深度覆盖系统设计与实现

针对移动信号室内深度覆盖需求和现有覆盖方案存在的问题，提出了一种以有线电视同轴电缆为入户通道的射频系统。分析了系统原理和几个关键问题，计算了系统各项设计参数，阐述了合路器、跨路器和智能终端三个主要部分的结构及阻抗匹配滤波、同步、放大等关键模块的实现方法。实地测试结果表明，系统各项指标符合设计和应用要求，实现了160 m2高层住宅的信号覆盖，提高了小区测量报告（MR）覆盖率，同时对移动室分系统性能也无影响。所提方案与现有方案相比具有低成本、施工快速、协调简单等优势，是一种新颖实用的室内深度覆盖实现方式。     

Being passionate about the mobile while travelling

People interpret the availability of their mobile phone similar to their personal (social) relationships (friends, family, and pets). Hence, mobile phones are appliances that provide continuous functional and emotional support. Also, in the field of tourism, the integrated use of mobile phones is indicated by words such as ‘catalyst’ and ‘travel buddies’, enhancing tourists’ experiences. This study goes one step further by incorporating the concept of passion and affective outcomes of using the mobile phone while travelling. Perceived socialness of the mobile phone significantly effects passionate behaviour and affective outcomes. For practitioners aiming for digital innovation in the field of tourism, these findings provide insight into the development of tailor-made travel-related applications. Furthermore, affective feelings derived from mobile phone usage will be enhanced by effective travel-related applications encouraging the modern tourists while travelling.     

Measuring user similarity using check-ins from LBSN: a mobile recommendation approach for e-commerce and security services

ABSTRACT

Social friendship and geographical position information often reflects individuals’ personal preferences and other types of knowledge that can be used to extract their similarity for recommendation systems. This paper finds that users are more likely to move around some specific centres or check in at some hotspots; a few individuals check in frequently, whereas most locations are rarely visited. Based on these findings, we propose a multi-centre clustering algorithm to capture users’ mobile patterns and develop a user similarity measurement method. Complexity analysis shows the method’s efficiency in handling large datasets and experimental results demonstrate its good applicability.     

WiMAX技术及其市场应用刍论

文章阐述了WiMAX技术的优势和组网方式,通过案例分析了WiMAX技术提供的多种应用方案和演进路线,认为WiMAX与3G等现有及其演进技术是相辅相成的,提出了要解决WIMAX在推广应用过程中存在的技术问题,抓住技术转化的市场机遇。     

基于IP架构的cdma2000 1x系统TrFO特性的设计与实现

本文介绍了基于IP架构的分组语音核心网的TrFO特性,并结合自行开发的cdma20001x系统,讨论了TrFO特性在基于IP架构的cdma20001x移动通信中的具体实现方案,详细讨论了多种声码器的灵活配置策略,并对各种策略进行了模拟比较,模拟结果对实际工程实现具有重要意义。