机器学习辅助的WiFi位置指纹算法研究

随着室内定位市场的不断扩大,人们对室内定位技术的要求越来越高。现有的WiFi位置指纹定位技术容易受到外部环境变化的影响,导致在中空楼宇进行平面定位时,存在将待定位点定位到中空区域的问题,不利于后续的导航规划。为了弥补这一不足,提出了一种基于机器学习辅助的WiFi位置指纹算法,通过机器学习将定位区域分割为不同的子区域,有效地避免了中空区域的误定位问题。实验结果表明,所提出的定位算法可以解决中空区域的误定位问题,具有较高的定位精度。

Spatial Spillover and the Factors Influencing Public Service Supply in Sichuan Province, China

This article examines the spatial characteristics of public service supply and the factors influencing such supply in cities of Sichuan Province, China using spatial-autocorrelation and spatial econometric models with statistical data in 2012. The results demonstrate that expenditures on different types of public services present different spatial autocorrelation patterns. Although the spatial differences in basic public service expenditures are relatively small, a clear fan-shaped spillover to the east can be seen in Chengdu City. Chengdu also shows high clustering of advanced public service expenditures, being a typical core-periphery pattern. Post-earthquake reconstruction expenditures are clustered in the "5.12 Wenchuan earthquake" region and spill over toward cities to the east. The efficiency of public services in the mountainous areas in western Sichuan is low and exhibits a pattern of low-low spatial autocorrelation. The efficiency of public service supply is affected by economic, social, political and geographical factors. Based on the results of this analysis, we recommend a supply strategy that incorporates different types of public services and a specialized public service supply strategy for mountainous areas. Overall public service efficiency should be enhanced by focusing on narrowing the gap in farmers' income among regions and accelerating urbanization. Decision-makers should consider moresupportive policies with regard to providing basic public services in mountainous areas to ensure an equalized supply of basic public services. To enhance the efficiency of advanced public service supply, additional growth pole should be encouraged and incentivized; however, investments are required to drive the development of the peripheral regions through regional economic integration. Both software and hardware types of infrastructure are required to supply services efficiently during post-disaster reconstruction.

Evolution Stages of Oasis Economy and Its Dependence on Natural Resources in Tarim River Basin

This paper examines spatio-temporal characteristics of an oasis economy and its relationship with water and mineral resources in the Tarim River Basin from 1965 to 2005. A spatial autocorrelation model, the center of gravity model, and index system of the regional central city are used to probe the evolution laws of spatial structure of oasis economy. The study finds that: 1) The economic centre of gravity, whose variation track during this period follows linear rate law, was moving from headstream to middle reaches of the Tarim River. 2) Positive spatial autocorrelation which showed a waving and ascending trend of regional economy was significant and the neighbor effect of regional economic growth was strengthened continuously. 3) The regional economic centre was located in Hotan City before 1980, moved to Aksu City during the 1980s and to Korla City after 1990. We conclude that above all, during the recent four decades the evolution of the oasis economy in this region has gone through three stages: a traditional agriculture stage (before 1980), oasis agriculture and agricultural product processing stage (1980–1990) and oasis energy industry stage (after 1990). Furthermore, the dependence degree of the oasis economy on natural resources in different stages are studied by using dominance index, regression model, and grey relation method, which shows that an oasis econ- omy highly depends on water resources in the oasis agriculture and agricultural product processing stage while it de- pends more on mineral resources such as oil and natural gas during the oasis energy industry stage.

The higher grain production, the more social deprivation? A case study of Henan province in traditional agricultural areas of China

This paper examines the spatial-temporal dynamics of inequality from the perspective of social deprivation in the context of continuous growth of grain production using national census data from 2000 and 2010 for Henan province,China.Our analytical results show an overall level of social deprivation that is high and a widening social deprivation gap at the county level.The social deprivation shows great spatiotemporal heterogeneity,the higher deprived counties are mainly distributed in central and eastern Henan province,while counties with lower social deprivation are clustered in northwestern regions,formed a belt-shape spatial differential between the south(higher deprived counties clustered)and northwest(low deprived counties clustered)Henan in 2000,and changed toward a core-periphery semi annular spatial structure in 2010,the low deprived counties surrounded by high deprived counties.The social deprivation shows a"west low and east high"spatial pattern,similar to the grain production in Henan province.Socioeconomic development level was low in most counties in Yudong plain despite of keeping the continuous increase of grain production,meaning the higher grain output did not result in the more social development expected in Chinese traditional agricultural areas,and the regional disparity is expected to increase in the near future if development conditions are not changed,which could inspire more targeted rural governance options.

Spatial Autocorrelation Analysis on Regional Economic Disparity of Northeast Economic Region in China

Popular regional inequality indexes such as variation coefficient and Gini coefficient can only reveal overall inequality, and have limited ability in revealing spatial dependence or spatial agglomeration. Recently some methods of exploratory spatial data analysis such as spatial autocorrelation have provided effective tools to analyze spatial agglomeration and cluster, which can reveal the pattern of regional inequality. This article attempts to use spatial autocorrelation at county level to get refined spatial pattern of regional disparity in Chinese northeast economic region over 2000-2006 (2001 absent). The result indicates that the basic trend of regional economy is an increasing concentration of growth among counties in northeast economic region, and there are two geographical clusters of poorer counties including the counties in western Liaoning Province and adjacent counties in Inner Mongolia, poorer counties of Heihe, Qiqihar and Suihua in Heilongjiang Province. This article also reveals that we can use the methods of exploratory spatial data analysis as the supplementary analysis methods in regional economic analysis.

Study on Potential Strong Earthquake Risks Around the Mabian Area,Southern Sichuan

Based on seismic data from the regional network for the last 34 years, we analyzed the present fault behavior of major fault zones around the Mabian area, southern Sichuan, and identified the risky fault-segments for potential future. The method of analysis is a combination of activity background of historical strong earthquakes mainly show ~ （ 1 ） The spatial distribution of b-values strong and large earthquakes in the spatial distribution of b-values with and current seismicity. Our results indicates significant heterogeneity in the studied area, which reflects the spatial difference of cumulative stress levels along various fault zones and segments. （2） Three anomalously low b-value areas with different dimensions were identified along the Mabian-Yanjin fault zone. These anomalies can be asperities under relatively high cumulated stress levels. Two asperities are located in the north of Mabian county, in Lidian town in western Muchuan county, and near Yanjin at the south end of the fault zone. These two areas represent potential large earthquake seismogenic sites around the Mabian area in the near future. Besides them, the third relatively smaller asperity is identified at southern Suijiang, as another potential strong- earthquake source. （3） An asperity along the southwestern segment of the Longquanshan fault zone indicates the site of potential moderate-to-strong earthquakes. （4） The asperity along the segment between Huangmu town in Hanyuan county and Longchi town in Emeishan city on Jinkouhe-Meigu fault has potential for a moderate-strong earthquake.

Discrete Wavelet Multi-scale Decomposition of the Temporal Gravity Variations in North China

On the basis of the absolute and relative gravity observations in North China,spatial dynamic variation of regional gravity fields is obtained. A multi-scale decomposition technique is used to separate anomalies at different depths,and give some explanation to gravity variation at different time space scales. Gravity variation trends in North China are improved. Based on this result and the analysis of wavelet power spectrum,the images of the depth of wavelet approximation and detail are obtained. The results obtained are of scientific significance for the deep understanding of potential seismic risk in North China from gravity variations in different time space scales.

Spatial expansion and potential of construction land use in the Yangtze River Delta

Based on remote sensing data of the Yangtze River Delta(YRD) in the years of 1991, 2001 and 2008, the paper built an index system of land use potential restraint factors in YRD, according to geological condition, terrain condition, water area, natural reserve area and basic farmland, and evaluated construction land potential based on the platform of GIS spatial analysis model. The results showed that:(1) the construction land increased rapidly since 1991 and reached 24,951.21 km2 in 2008, or 21.27% of the total area. Among all the cities in the YRD, Shanghai took the greatest percentage, followed by Jiangsu and Zhejiang. Spatially, areas where government departments are located became the growth center of construction land. Prefecture-level cities were the fastest growth region and the changing trend showed circle layered characteristics and significant increase with Shanghai and Suzhou as the core.(2) The higher the quality of construction land potentials(CLP), the smaller the number of CLP units. High sensitive area accounted for the largest percentage(40.14%) among all types of constraint regions and this was followed by medium sensitive region(31.53%) of the whole region.(3) The comprehensive CLP in the YRD was 24,989.65 km2, or 21.76% of the total YRD. The land use potential showed spatial distribution imbalance. CLP of Zhejiang was obviously larger than that of Jiangsu. CLP was insufficient in regional central city. Moreover, CLP in the YRD formed a circle layered spatial pattern that increasingly expanded centered in prefecture-level cities. Low potential area expanded from north to south. High potential area was mainly located in south YRD. Areas with zero potential in the YRD formed a northwest-southeast "Y-shaped" spatial pattern in north Hangzhou Bay.(4) CLP per capita in YRD was 0.045 ha/person and also unevenly distributed. Some 25.57% of the study units at county level nearly had no construction land and 8.24% of the units had CLP per capita below the national average level. CLP per capita in less than 25% of the county-level units was larger than the YRD average level, which were mainly located in Zhejiang. Therefore, research on the construction potential area in YRD was favorable for analysis of the development status and potential space of this region under the background of rapid urbanization and industrialization.

Regional differences of border geo-cities in China and the surrounding countries

As the improvement of international status and the implementation of China's neighboring diplomacy, the development of border regions and the security of border cities, as well as their spatial structure and regional differences are gaining more attention from academic circle. Based on the interdisciplinary perspectives of urban geography, regional economics and geopolitics, this paper explores the regional differences of border geo-cities in China and the surrounding countries with the help of remote sensing information acquisition and Arc GIS spatial analysis. Three primary results are found as follows:(1) The border geo-cities in China and surrounding countries are divided into five geographical regions: geo-cities in South China Sea, geo-cities in Southeast Asia, geo-cities in South Asia, geo-cities in Central Asia and geo-cities in Northeast Asia.(2) In the spatial structure system of China's border geo-cities, the importance of geo-cities in five major regions is fairly different. In terms of the security and economic development, the rank of priority is geo-cities in Northeast Asia, geo-cities in South China Sea, geo-cities in Central Asia, geo-cities in South Asia, geo-cities in Southeast Asia.(3) Considering China's geo-setting for the development of border geo-cities, the east region is significantly better than the west, and the north region is slightly better than the south.

Evolutionary model of the central place hierarchical system

Central place theory is one of the two theoretical cornerstones of geography, yet it cannot be connected with other spatial structure models, fails to provide definite time-space parameter conditions, lacks an evolutionary process model, and does not easily enable construction of a complete theoretical system of regional spatial structure. This paper gives an in-depth analysis of the process and mechanism for production and evolution of central places of different grades, and constructs an evolutionary model of the central place hierarchical system. The results of deduction, analysis and simulation show that production and evolution of the central place hierarchical system may be divided into five stages. These stages are the embryonic, formative, improvement, maturation, and advancement stages. Affected by spatial location and centricity, central places have obvious differences in scale and functional structures. There are great differences in the scale of same-grade central places. However, low-grade central places could have larger scales than high-grade central places, and the central places of a central location may form the agglomeration area of central places. Based on the hypothesis condition of an isotropic plain, the research shows that it is possible not only to form proportional functional structures of central places, but also to produce non-proportional scale structures of central places, and thus to complete the transformation from rationalistic deduction of spatial equilibrium mode to an explanation and demonstration of an unbalanced practical model.