基于改进指纹聚类的WLAN定位优化方法

将K-means聚类算法应用到无线局域网（WLAN）位置指纹定位中，虽然可以缩短定位时间，但是容易降低定位精度。为了解决此问题，提出了基于改进指纹聚类的WLAN定位优化方法。首先根据接收信号强度标准差来优化初始聚类中心的选取,然后对指纹数据进行聚类处理,最后进行在线定位。实验结果表明，与传统的WLAN位置指纹定位方法和K-means聚类定位方法相比，基于改进指纹聚类的定位优化方法不仅缩短了定位时间，还能有效提高定位精度。     

一种改进的CPFSK信号频率估计方法

针对突发信号解调中多普勒频偏大的问题，提出了一种改进的连续相位移频键控信号(CPFSK)频率估计方法。首先接收信号平方运算使信号的调制指数加倍，再通过一次离散傅里叶变换(DFT)，用搜索信号平方谱谱峰的方法实现突发信号频率估计。仿真实验表明，在低信噪比条件下，该算法的频率估计精度比经典的相位差频率估计算法提高了20%；该算法与广泛用于高动态突发信号的频率插值估计算法相比，同道干扰信道下信干比改善可达4 dB，DFT长度缩短约1/3。     

甘肃省耕地质量等别特征与空间分布研究

[目的]摸清甘肃省耕地质量空间分布地区差异,整体把握全省耕地质量状况,以期为耕地保护策略制定提供参考依据。[方法]文章基于Arc GIS 10.0软件,以2015年耕地质量等别更新评价县级数据和省级汇总数据为主,采用克里格空间插值法研究了省域范围内耕地质量的空间格局,采用对比研究法、分类统计法分析了全省、各市州及各区域的耕地质量状况。[结果](1)甘肃省存在4个中等质量耕地分布区域。自然质量等别、利用等别和经济等别下的中等质量等值区逐渐缩小:在陇南逐步向东南方向缩进,在河西走廊逐步由张掖向西北缩进,在兰州白银一带由带状区域缩小至零星区块;(2)全省耕地质量分布在8~15等,平均为13.1等,比全国耕地平均等别低3.1等;(3)各市(州)和各二级区耕地质量等别差异明显,中等地主要分布在河西走廊地区,低等地集中在陇东和陇中地区。[结论]甘肃省耕地质量等别总体偏低,基于耕地质量的耕地保护策略值得决策部门进一步关注,应持续研究耕地质量随时间的变化态势并在评价过程中考虑"土壤污染"因素。     

US small retail businesses’ perception of competition: Looking through a lens of fear,confidence, or cooperation

The U.S. retail industry has undergone dramatic changes, leading to the closing of brick-and-mortar retail stores on a large scale. Understanding perceived market competition among small retail businesses may help explain why certain businesses survive or fail in the altered retail environment. This study investigates small retail businesses' perceptions of competition within/outside the community, underlying reasons for their perceptions, and variations in perceptions by different business characteristics. Contrary to common expectations, we found that more than half of businesses interviewed were optimistic in the face of competition. Our data reveal two salient underlying reasons for pessimism and five for optimism. These perceptions tended to differ by operational locality (urban clusters vs. urban areas), business revenues, and innovativeness. Based on the findings, we developed propositions and a framework of small businesses' perceived competition and sustainable competitive advantage. We discussed theoretical and practical implications for small retail businesses’ sustainable growth in the challenging retail environment.     

Using segmentation to compete in the age of the sharing economy: Testing a core-periphery framework

Airbnb has emerged as a credible competitive threat to the hotel industry. Consequently, hotel brands are having to rethink the experiences they provide to customer in an increasingly competitive environment. Despite these trends in the industry, experience-related research that examines and informs these developments remains under-represented in the hospitality and tourism literature. The present study offers a systematic approach to examine the potential differences in experiential consumption in the accommodations industry. Using a multiple-group analysis approach, it examines the moderating effects of individual characteristics and situational factors on the nature and dynamics of experiential consumption in the accommodations industry. The findings of the study culminate in the core-periphery framework of the hospitality consumption experience that can provide a relevant theoretical lens for future research into the different sectors and types of experiences within the hospitality and tourism industry. The study also outlines important implications for the hotel industry’s strategic experience design initiatives, from the standpoint of product development, the segmentation, targeting and positioning (STP) process, and marketing communications.     

煤矿上山掘进轨道双提升系统的设计及应用

本文介绍了煤矿长斜巷正头掘进与斜巷中段联巷掘进同时施工的新型运输方式。     

Discretionary effort of regional hospitality small business employees: Impact of non-monetary work factors

This research examines the impact of non-monetary work environment factors on employee discretionary effort within the hospitality sector in the South West Region of Western Australia. Limited qualitative research has previously examined the factors that drive employee discretionary effort especially in the regional hospitality sector. Semi-structured interviews were conducted with 20 hospitality employees using purposive sampling. While the findings are preliminary, they do highlight important aspects of discretionary effort within a regional context. Critically, two previously un-identified factors, employees’ professional identity and perception of the hospitality sector have been found to have important implications for employees’ discretionary effort and need to be further explored. Additionally, the findings support the direct influence of organisational culture, job design, interpersonal relationships, on discretionary effort. Finally, the research confirms that a paternalistic leadership approach has a significant influence on hospitality employees’ discretionary effort. Theoretical and practical implications and directions for future research are outlined.     

我国中小企业三维差异化特征比较研究

作为推动国民经济增长和促进社会稳定的基础力量,中小企业在市场中扮演着最活跃的经济主体。与大企业相比,中小企业有其鲜明的成长特征,从动态演进视角选取体量规模、生命周期、要素需求三个维度,系统探讨了中小企业的差异化特征。结论显示:体量规模特征反映在个体与群体以及经济板块之间;生命周期特征体现在死亡陷阱和空间格局演变上;要素需求特征会根据阶段创新内容的不同做出适时调整。     

全域旅游示范区空间分布特征及影响因素分析

［目的］全域旅游示范区的确立为旅游业增添了新的旅游吸引模式，成为新时期我国旅游产业转型升级的重要途径之一。［方法］文章利用ArcGIS102，运用最邻近距离法、不均衡指数、核密度分析、等方法，对标记在地图上的500个全域旅游示范区的空间分布特征进行分析，并探究其空间分布差异的影响因素。［结果］（1）示范区空间分布不均衡，呈典型的聚集型分布，从区域角度来看，西部地区示范区数量多于东部地区，中部地区相对较少，与传统认知上的示范区分布格局存在一定错位； （2）示范区空间分布密度存在明显差异，其中江浙皖、湘赣交界、晋豫交界、陕渝交界等地区示范区聚集最多，形成显著的高密度区； （3）示范区规模度差距较大，上海、北京、江苏、天津等省市规模度较大，其他省市规模度较小； （4）示范区空间分布受到资源禀赋、区位交通、社会经济、政策环境等因素影响较大，呈现“傍景”“环路”的分布格局。［结论］全域旅游示范区空间分布不均衡，各省市既要挖掘自身核心竞争力，也要加强区域协调发展，突出示范区模范带头作用，达到辐射周边市县的效果，实现全域旅游资源优化配置。     

Financial analyst coverage for U.S. firms facing foreign competition: Evidence from trade liberalization

This study examines financial analyst coverage for U.S. firms following an increase in foreign product market competition. To capture exogenous shocks to domestic firms' competitive environments, we exploit a quasi‐natural experiment from large import tariff reductions over the 1984 to 2005 period in the manufacturing sector. Using data for the years before and after large tariff reductions, our difference‐in‐differences analysis shows evidence of a significant decrease in analyst coverage for incumbent U.S. firms when they face greater entry threat from foreign competitors. We also find that analysts with less firm‐specific experience and less accurate prior‐period forecasts are more likely to stop following the domestic firm when foreign competition intensifies. Overall, the findings suggest that foreign product market competition from global trade liberalization is an important determinant of financial analysts' coverage decisions.