区域创新网络的系统“区位”研究

区域创新网络不仅是国内外经济界、地理界、产业界共同关注的理论前沿,而且还是一种解决现实问题的制度框架,是缩小区域差距、实现统筹发展的一揽子方案。本文通过对比区域创新网络与区域创新环境、区域创新系统、发展极、产业集群、高科技园区、全球网络之间的关系,对区域创新网络作出了多维视角中的系统“定位”,以使区域创新网络的构建活动始终在正确的方向上推进。

安康地区区域区位系统转化及经济开发

以区位系统转化为背景，分析了安康地区区位系统转化后新的发展条件，就安康地区未来发展的城市建设、工业结构。

Study of Interval Type-2 Fuzzy Controller for the Twin-tank Water Level System

For dealing with large static error due to poor immunity of the traditional fuzzy control, a novel interval type-2 fuzzy control system is proposed. By extending the typical membership functions to interval type-2 membership functions, the proposed control system can efficiently reduce the uncertain disturbance from real environment without increasing the design complexity. The simulation results on the water tank level control system showed that the proposed method succeeded in better static and dynamic control with stronger robust performance than the traditional fuzzy control method.

Monitoring Land Use Dynamics in Chanthaburi Province of Thailand Using Digital Remotely Sensed Images

A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning System) and ancillary data were combined by the method which adopts the main idea of classifying images by steps from decision tree method and the hybridized supervised and unsupervised classification. An integration of automatic image interpretation, ancillary materials and expert knowledge was realized. Two subscenes of Landsat 5 Thematic Mapper (TM) images of bands 3, 4 and 5 obtained on December 15, 1992, and January 17, 1999, were used for image processing and spatial data analysis in the study. The overall accuracy of the results of classification reached 90%, which was verified by field check.Results showed that shrimp farm land, urban and traffic land, barren land, bush and agricultural developing area increased in area, mangrove, paddy field, swamp and marsh land, orchard and plantation, and tropical grass land decreased, and the forest land kept almost stable. Ecological analysis on the land use changes showed that more attentions should be paid on the effect of land development on ecological environment in the future land planning and management.

A Position-Based Handoff Scheme in WAVE Systems

IEEE 802.11p has been proposed to extend the application of IEEE 802.11 to Wireless Access fast fading Vehicular Environments (WAVE).Due to the high velocities of vehicles and thus the inconstant topology of networks,it is extremely difficult to maintain communications without handoff in an Internet of Vehicles (IoV).Hence,fast handoff from one roadside unit (RSU) to another is necessary.Although some solutions have been given in IEEE 802.11r and 802.11f standards,the handoff latency is still as high as about 50 ms when adopting them.To address this issue in WAVE systems,a novel position-based handoff (PHO) scheme is proposed in this paper.In PHO scheme,the triggering of the handoff is accomplished by the location information of a vehicle instead of the power level of the received signal.Both the handoff process and latency of PHO scheme are analyzed.Finally,to verify the analytical results,simulations were conducted to date the effectiveness of the proposed PHO scheme.

Human Settlement Evaluation in Mountain Areas Based on Remote Sensing,GIS and Ecological Niche Modeling

The Qinghai-Tibet Plateau is the word＇s highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling （ENM） for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method （Maxent）, an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial auto- correlation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold- independent model performance was reasonable according to lO times model running, with the area under the curve （AUC） values being 0.917± 0.01, and 0.923±0.002 for test data. Cohen＇s kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas aceounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area.The decisive environmental factors were slope and two climate variables： mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management.

ANALYSIS ON STRUCTURE OF TYPHOON LONGWANG BASED ON GPS DROPWINSONDE DATA

As one of the most severe typhoons in the year 2005,Typhoon Longwang is chosen as a case study in this article.Throughout its life,two surveillance flights are carried out on it.Different from previous studies,GPS(global positioning system)Dropwinsonde data collected from the Dropwinsonde Observations for Typhoon Surveillance near the Taiwan Region is chosen to present the thermodynamic and kinetic structure at its two different stages of development.This study suggests that not only kinetic structure but also thermodynamic structure of Longwang are more robust in the second surveillance than the first surveillance,with stronger and larger circulation and a warmer core.Further research shows that the environmental vertical wind shear mainly contributes to the asymmetric structure of the typhoon.The strong vertical wind shear not only results in the distinct asymmetric structure,but also restrains the development of the typhoon.

Remote Sensing of Sea Surface Wind of Hurricane Michael by GPS Reflected Signals

In this paper, the propagating geometry and the w av eform of the GPS reflected signals are expatiated in detail. Furthermore, the pr inciple and the method of retrieving sea surface wind are presented. In order to test the feasibility of retrieval, the experiment data obtained by NASA in Hurr icane Michael are used. The result shows that the retrieval accuracy of wind spe ed is about 2 m/s.

Autonomous map query:robust visual localization in urban environments using Multilayer Feature Graph

When a vehicle travels in urban areas, onboard global positioning system （GPS） signals may be obstructed by high-rise buildings and thereby cannot provide accurate positions. It is proposed to perform localization by registering ground images to a 2D building boundary map which is generated from aerial images. Multilayer feature graphs （MFG） is employed to model building facades from the ground images. MFG was reported in the previous work to facilitate the robot scene understand- ing in urhan areas. By constructing MFG, the 2D/3D positions of features can be obtained, inclu- cling line segments, ideal lines, and all primary vertical planes. Finally, a voting-based feature weighted localization method is developed based on MFGs and the 2D building boundary map. The proposed method has been implemented and validated in physical experiments. In the proposed ex- periments, the algorithm has achieved an overall localization accuracy of 2.2m, which is better than commercial GPS working in open environments.

Preliminary assessment of the navigation and positioning performance of BeiDou regional navigation satellite system

BeiDou regional navigation satellite system （BDS） also called BeiDou-2 has been in full operation since December 27, 2012. It consists of 14 satellites, including 5 satellites in Geostationary Orbit （GEO）, 5 satellites in Inclined Geosynchronous Orbit （IGSO）, and 4 satellites in Medium Earth Orbit （MEO）. In this paper, its basic navigation and positioning performance are evaluated preliminarily by the real data collected in Beijing, including satellite visibility, Position Dilution of Precision （PDOP） value, the precision of code and carrier phase measurements, the accuracy of single point positioning and differential position- ing and ambiguity resolution （AR） performance, which are also compared with those of GPS. It is shown that the precision of BDS code and carrier phase measurements are about 33 cm and 2 mm, respectively, which are comparable to those of GPS, and the accuracy of BDS single point positioning has satisfied the design requirement. The real-time kinematic positioning is also feasible by BDS alolae in the opening condition, since its fixed rate and reliability of single-epoch dual-frequency AR is comparable to those of GPS. The accuracy of BDS carrier phase differential positioning is better than 1 cm for a very short baseline of 4.2 m and 3 cm for a short baseline of 8.2 km, which is on the same level with that of GPS. For the combined BDS and GPS, the fixed rate and reliability of single-epoch AR and the positioning accuracy are improved significantly. The accu- racy of BDS/GPS carrier phase differential positioning is about 35 and 20 % better than that of GPS for two short baseline tests in this study. The accuracy of BDS code differential positioning is better than 2.5 m. However it is worse than that of GPS, which may result from large code multipath errors of BDS GEO satellite measurements.

Land use in semi-free ranging Tonkean macaques Macaca tonkeana depends on environmental conditions： A geographical information system approach

Wild animals use their habitat according to ecological pressures such as predation, resource availability or tempera- ture, yet little is known about how individuals use their environment in semi free-ranging conditions. We assessed whether a semi-free ranging group of Tonkean macaques Macaca tonkeana used its wooded parkland in a heterogeneous way. GIS and GPS were used to determine whether individuals adjusted their behaviors according to variation in environmental constraints over time of day and the course of a year. We demonstrated that social and resting activities occurred in high altitude areas and areas with a high density of bushes, whereas the group foraged in areas where the density of bushes and grass was low. In general, the animals used areas exposed to the sun that were not on a slope. Semi-free ranging Tonkean macaques seemed to behave like their wild counterparts in terms of activity budget, land use per activity and thermoregulation