Kunming Area Research Articles

Research on the Spatial-temporal Changes and Driving Forces of City Green Space in Kunming

To explore the spatial and temporal changes and driving forces of city green space in Kunming since 1950, and provide a reference for future city green space development planning. Through consulting a large number of documents, Kunming statistical yearbook and field investigation, the geospatial analysis method and comparative analysis method were used to analyze the spatial and temporal changes of the park green space above 5hm2 in the downtown area of Kunming, and its driving force was analyzed by qualitative analysis method. The results shows that (1) There are four development stages in the construction of city green space in the downtown of Kunming. (2) The city green space in Kunming city center> 5hm2 ranks in order as Chenggong District, Panlong District, Xishan District, Wuhua District, Guandu District. (3) There are four trends in the spatial distribution of city green space. (4) The driving force mainly includes geographical factors, economic factors, population factors, transportation factors, and policy factors. After the comprehensive effect of various aspects, the current city green space distribution pattern in Kunming is formed.

Cancer Screening Program in Urban Kunming of Yunnan: Evaluation of Lung Cancer Risk Assessment and Screening

背景与目的肺癌是最常见的恶性肿瘤，预后较差，5年生存率较低，早期筛查是肺癌防治的重要措施。目前，不同国家和地区发布了相应的肺癌筛查指南，但我国仍缺乏基于中国人群研究的指南。因此，国家癌症中心在全国启动了多中心的城市癌症早诊早治项目研究。本研究分析了城市癌症早诊早治项目中云南省单中心的肺癌高危人群评估模型及临床筛查应用效果，为探索适合我国国情的肺癌高危人群评估模型及制定和更新中国人群肺癌筛查指南提供一定的参考依据。方法采取整群抽样的方法，于2015年1月-2019年12月对云南省昆明市4个主城区36个街道办事处165, 337人进行问卷调查及肺癌风险评估，评估为高风险者进行胸部低剂量计算机断层扫描（low-dose computed tomography, LDCT）筛查。同时对所有参与者进行主动随访和被动随访，获得详细的临床结局，进行统计分析。结果整体人群5年间经病理确诊肺癌患者264例，总体肺癌发生率为0.16%（264/165, 337），高风险组（0.31%, 116/37, 914）高于非高风险组（0.12%, 148/127, 423），差异有统计学意义（P < 0.001）。不同性别和不同年龄的亚组分析显示高风险组肺癌发生率均高于非高风险组，均有统计学差异（P < 0.001），但在未进行LDCT筛查组无统计学差异（P=0.73）。肺癌高危人群评估模型的敏感性为43.94%（116/264），特异性为77.10%（127, 275/165, 073）。筛查组早诊率为72.97%（54/74），明显高于非筛查组的28.48%（43/151）。结论国家重大公共卫生服务项目城市癌症筛查项目肺癌高危人群评估模型能有效检出高风险人群，提高肺癌早诊率。

Psychometric evaluation of the Chinese version of the Person-Centred Care Assessment Tool

ObjectiveThis study aims to test a Chinese cross-cultural adaptation of the English version of the Person-Centred Care Assessment Tool (P-CAT) and evaluate its psychometric properties.DesignP-CAT was translated/back-translated using established procedures...

New occurrence of the Guanshan Lagerstätte (Cambrian Series 2, Stage 4) in the Kunming area, Yunnan, southwest China, with records of new taxa

As a classic Burgess-Shale-Type Konservat-Lagerstätte, the Guanshan biota is well known for its abundant soft-bodied fossils with high taxonomic diversity. Here, we report a new locality of the Guanshan biota in the Kunming area, Yunnan, South China with several new forms being first documented. In particular: a naraoiid euarthropod, the dorsal exoskeleton of which has characters of both naraoiids and Emucaris; and a discoidal animal, identified as a small eldonioid-like metazoan, which has a counterpart from the Emu Bay Shale Lagerstätte of South Australia, and which further strengths the biogeographic connection between the early Cambrian biotas of South China and Australia. Our new discoveries not only expand the palaeogeographic distribution of the Guanshan biota, but also reveal that its biodiversity is much higher than previously thought, and can be justifiably regarded as a community successor to the Chengjiang biota.Jun Zhao [zhaojunpaleo@126.com], Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming, Yunnan, 650091, China; Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, Kunming 650091, China; MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming, Yunnan, 650091, China; Yujing Li [yujingli@ynu.edu.cn], Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming, Yunnan, 650091, China; MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming, Yunnan, 650091, China; Paul A. Selden [selden@ku.edu], Department of Geology, University of Kansas, 1457 Jayhawk Boulevard, Lawrence, KS 66045, USA; Natural History Museum, Cromwell Road, London SW7 5BD, UK; Peiyun Cong [cong@ynu.edu.cn], Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming, Yunnan, 650091, China; MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Institute of Palaeontology, Yunnan University, Kunming, Yunnan, 650091, China.

Spatiotemporal Analysis of Air Pollutant Concentrations in Major Transportation Hubs of Kunming : A Case Study of Dongfeng East Road Station

The rapid development of industrialization and the continuous acceleration of the urbanization process have continuously improved the quality of life of the people, but at the same time brought important environmental problems such as air pollution and climate change that humans have to face today. In this paper, the meteorological data of Dongfeng East Road Station in Kunming is taken as the research object, and the Spark platform is used to quickly and effectively analyze the air pollution data of Dongfeng East Road Station. Through analysis and research on the air pollution-related conditions of major transportation hubs in Kunming in recent years, the results show that the concentration of air pollutants at Dongfeng East Road Station in Kunming has a relatively obvious downward trend, especially the significant decline in SO2 and CO. As far as air quality is concerned, the air quality in some areas of Kunming continues to improve.

Investigation of window-opening behaviour and indoor air quality in dwellings situated in the temperate zone in China

Indoor air quality (IAQ) is a key factor that could affect the indoor environment and people's health. In this study, we report a comprehensive study on IAQ in 30 dwellings in the temperate zone in China. Thirty naturally ventilated dwellings were selected in the urban area of Kunming, which is the largest city in temperate zone in China. In four seasons, short-term measurement of formaldehyde and benzene, toluene, xylenes-volatile organic compounds and air infiltration rate were conducted in these dwellings. A long-term 1-year monitoring of temperature, relative humidity, fine particulate matter (PM2.5), carbon dioxide (CO2), window-opening behaviour and night-time air change rate (ACR) were conducted in 13 of these dwellings by remote sensors. Short-term measurements showed the mean formaldehyde concentration in summer (100.76 μg/m3), benzene concentration in winter (8.46 µg/m3), PM2.5 concentration (80.4 µg/m3) in spring of 2017 exceeded the Chinese standard, the US Office of Environmental Health Hazard Assessment value and the World Health Organization guidelines. The night-time ACR was the highest in summer (2.1 h−1) and the lowest in winter (1.6 h−1) in bedrooms of 13 long-term monitored dwellings due to seasonal time variation in window opening in bedrooms, which was mainly driven by CO2 concentration, indoor temperature and outdoor PM10 concentration.

Evaluating the generalization ability of convolutional neural networks for built-up area extraction in different cities of China

The difficulty of build-up area extraction is due to complexity of remote sensing data in terms of heterogeneous appearance with large intra-class variations and lower inter-class variations. In order to extract the built-up area from Landsat 8-OLI images provided by Google earth engine (GEE), we propose a convolutional neural networks (CNN) utilizing spatial and spectral information synchronously, which is built in Google drive using Colaboratory-Keras. To train a CNN model with good generalization ability, we choose Beijing, Lanzhou, Chongqing, Suzhou and Guangzhou of China as the training sites, which are very different in term of natural environments. The ArcGIS-Model Builder is employed to automatically select 99 332 samples from the 38-m global built-up production of the European Space Agency (ESA) in 2014. The validate accuracy of the five experimental sites is higher than 90%. We compare the results with other existing building data products. The classification results of CNN can be very good for the details of the built-up areas, and greatly reduce the classification error and leakage error. We applied the well-trained CNN model to extract built-up areas of Chengdu, Xi’an, Zhengzhou, Harbin, Hefei, Wuhan, Kunming and Fuzhou, for the sake of evaluating the generalization ability of the CNN. The fine classification results of the eight sites indicate that the generalization ability of the well-trained CNN is pretty good. However, the extraction results of Xi’an, Zhengzhou and Hefei are poor. As for the training data, only Lanzhou is located in the northwest region, so the trained CNN has poor image classification ability in the northwest region of China.

Abstract 228: Epidemiology and Outcome of Out-Of-Hospital Cardiac Arrests in Kunming, Yunnan, China

Objective: The purpose of this study was to better understand the epidemiological features and outcomes of emergency medical service(EMS)-assessed out-of-hospital cardiac arrests(OHCAs) in Kunming,Yunnan,China. Methods: In this prospective study,datas were collected according to the Utstein style on all cases of OHCAs from January 2010 to December 2014 in urban areas covered by Kunming EMS system.The outcomes were analysed at four time points of survival: no return of spontaneous circulation (no-ROSC),return of spontaneous circulation (ROSC),survival to hospital admission, and survival to hospital discharge.The adjusted odds ratios(ORs) and 95% confidence intervals(CIs) for survival were calculated and adjusted for potential risk factors using stratified multivariable logistic regression analysis. Results: There were 3387 EMS-assessed OHCAs with cardiac aetiology from 2010 to 2014. The incidence of EMS-assessed OHCA with cardiac aetiology was 20.7 per 100,000 inhabitants per year. Of the 3387 EMS-assessed OHCAs with cardiac aetiology,the rates of ROSC,survival to admission and survival to discharge were 12.4%,3.5% and 0.9% respectively. There were only 73(2.2%)patients with initial rhythm of ventricular fibrillation(VF) or pulseless ventricular tachycardia(VT) observed in the EMS-assessed OHCAs with cardiac aetiology.There was no statistical difference among the five years in outcomes of OHCAs with cardiac aetiology.Younger age, bystander CPR,witnessed by EMS, OHCA with initial rhythm of VF/pulseless VT,shorter medication interval,and shorter response interval were associated with a higher rate of survival to discharge respectively. Conclusion: In the urban areas of Kunming covered by EMS system, survival outcome of OHCA was unsatisfactory.Improvements are required in every link of the chain of survival.

Analysis of colorectal cancer screening results in Kunming from 2014 to 2017

This study analyzed the distribution of high-risk population, the compliance and detected lesions of colorectal cancer screening from the Cancer Screening Program in urban areas of Kunming,Yunnan Province from 2014 to 2017. A total of 127 960 residents were included,of which 14 791 (11.70%) cases were diagnosed with high risk of colorectal cancer by the National Cancer Center High Risk Population Assessment System. A total of 3 484 cases completed colonoscopy clinical screening and the rate of participation was 23.55%. The screening results showed that 592 positive cases were detected, and the positive rate was 17.17%. The detection rates of polyps,adenomas,advanced adenomas,precancerous lesions and colorectal cancer were 16.27%,13.12%,7.18%,7.63% and 0.26%, with 567, 457, 250, 266 and 9 cases, respectively.

Breastfeeding rates of children under two years old in nine cities of China from 1985 to 2015:a comparison between urban and suburban areas

Objective To analyze the breastfeeding rate of children under two years of age in nine cities of in 2015 and variations in breastfeeding patterns from 1985 to 2015. Methods All data were collected from a series of national cross-sectional surveys National Growth Survey of Children under Seven Years Old in Nine Cities of China (urban and suburban areas of Beijing, Haerbin, Xi'an, Wuhan, Nanjing, Shanghai, Guangzhou, Fuzhou and Kunming) conducted from each May to October in 1985, 1995, 2005 and 2015. Stratified cluster sampling was used to select healthy children at least 150 in each subpopulation. Feeding patterns within 24 h prior to investigation were analyzed through face-to-face interviews using a self-made questionnaire. The rates of exclusive breastfeeding, mixed feeding and formula feeding were described as composition ratios. The difference between urban and suburban areas was analyzed by Chi-square test and the weaning age was calculated with a Probit model. Results (1) In 2015, the exclusive breastfeeding rate for infants under six months of age was 48.8% (9 143/18 722) in urban areas and 48.4% (8 652/17 878) in suburban areas, and the breastfeeding rates at one and two years old were 36.1% (1 351/3 746) and 5.8% (211/3 668) in urban areas and 29.9% (1 128/3 776) and 4.3% (157/3 683) in suburbs. The differences of breastfeeding patterns in ≥1-<2, ≥2-<3, ≥3-<4, ≥5-<6, ≥10-<12, ≥12-<15, ≥18-<21 and ≥21-<24 months of age were all significantly between suburbs and urban areas (χ2=8.575-36.299, all P<0.01). The age at weaning age was 9.4 months and 9.3 months in urban and suburban areas, respectively. (2) From 1985 to 2005, breastfeeding rates showed a decreasing trend, especially in suburban areas where the exclusive breastfeeding rate for infants under six months of age decreased from 60.2% (8 898/14 780) to 42.5% (6 487/15 261) and the continuous breastfeeding rate decreased from 60.1% (2 164/3 600) to 27.6% (783/2 838) at the age of one and from 8.9% (320/3 600) (in 1995) to 3.0% (85/2 850) in 2015 at the age of two. However, from 2005 to 2015, breastfeeding rates were on the rise, especially in urban areas in which the exclusive breastfeeding rate for infants under six months of age increased from 32.8% (5 176/15 782) to 48.8% (9 143/18 722) and the continuous breastfeeding rates at one and two years old respectively increased from 17.0% (499/2 940) to 36.1% (1 351/3 746) and from 1.2% (34/2 856) to 5.8% (211/3 668). Conclusions There are great changes in breastfeeding patterns for Chinese children in the nine cities from 1985 to 2015. In the first two decades, breastfeeding rates decreased and the duration of breastfeeding was shortened, while the last decade have seen increased breastfeeding rates and longer breastfeeding duration. The exclusive breastfeeding rate for infants under six months of age is similar in urban and suburban areas and both have reached about to 50% in 2015, which indicates fruitful results have achieved through the implementation of infant feeding strategies and related measures in China. Key words: Breast feeding; Infant

Ichnology, palaeoenvironment, and ecosystem dynamics of the Early Cambrian (Stage 4, Series 2) Guanshan Biota, South China

The Guanshan Biota of the Wulongqing Formation (Cambrian Series 2, Stage 4) is a typical Burgess Shale‐type Lagerstätte, containing not only a diverse assemblage of exceptionally preserved body fossils but also abundant, sophisticated trace fossils. Detailed ichnological study of the lower part of the Wulongqing Formation from the Longbaoshan and Xinglongcun sections in the Kunming area, Yunnan, South China, reveals the presence of 17 ichnospecies, including Aggregatella isp., Cruziana isp., Didymaulichnus lyelli, Diplichnites isp., Guanshanichnus glockerichnoides, Monomorphichnus isp., Palaeophycus isp., Planolites beverleyensis, Planolites montanus, Planolites isp., Psammichnites isp., Phycodes isp., Skolithos verticalis, Thalassinoides isp., Treptichnus pedum, and two types of non‐specific coprolites. These trace fossils represent burrowing or locomotion behaviours of arthropods and vermes, and belong to the Cruziana and Skolithos ichnofacies. As the outcrop at the Xinglongcun section is not well exposed, a systematic sedimentary study was conducted at the Longbaoshan section. The Guanshan ichnofauna in the lower Wulongqing Formation at the Longbaoshan section occur in fine‐grained siliciclastic rocks with wavy bedding, lenticular bedding, and wrinkle structures, reflecting a tidal flat environment. The abundance of diverse trace fossils in the tidal flat facies indicate that many taxa, mostly arthropods, were able to colonize the very shallow marine environments, supporting the landward expansion of the Early Cambrian ecosystems.

Retrieval of Land Surface Temperature from Landsat 8 for the Main Urban Area of Kunming

Based on Landsat 8 TIRS 10 data, using the radiative transfer equation (RTE) and the improved mono-window algorithm (TIRS_SC) to retrieve the land surface temperature (LST) for the main urban area of Kunming, and compare the accuracy of the two methods. Then use the high precision method to retrieve LST of the main urban area of Kunming in 2013-2015. Results showed that RTE is more suitable for retrieval LST in the main urban area of Kunming. The LST of most area in Wuhua District and Guandu District is higher, and the low LST is mainly the Dian Lake and other region where there is water.

New observations on Vetulicola longbaoshanensis from the Lower Cambrian Guanshan Biota (Series 2, Stage 4), South China

Cambrian vetulicolians are enigmatic metazoans which play an important role in understanding the early animal evolution. Vetulicola longbaoshanensi s Yang et al., 2010 is a unique species reported from the Guanshan Biota, Cambrian Series 2, Stage 4 at eastern Yunnan, South China, which expands our understanding of vetulicolians. Here, new exceptionally preserved materials of V. longbaoshanensis from the Lower Cambrian Wulongqing Formation (which yields the so-called Guanshan Biota) in both Wuding and Kunming areas are described, in which the gill structures of V. longbaoshanensis are well preserved. The gill structures of our fossils are more complicated than those in the type species: the gill sac is gourd-shaped and can be divided into a smaller anterior part and a larger posterior part, prominent gill silt and dense gill filaments present in the joint of the two parts. Comparative analyses indicate that vetulicolians from the Guanshan Biota are similar to the Vetulicola rectangulata Luo et Hu, 1999 from the Chengjiang Biota in gross morphology. However, compared with the V. rectangulata , the Guanshan forms possess a larger body size, a higher length/ height ratio of anterior body, and a higher ratio of gill sac width to anterior body height, probably typifying the derive characters anticipated of vetulicolians. These new materials, therefore, shed new light on our understanding of vetulicolians morphology and the early evolution of the gill structures.

Effects of Rainfall in Kunming on the Growth and Alkaline Phosphatase Activity of the Cyanobacterium Microcystis aeruginosa

The effects of rainwater on freshwater ecosystems have received increasing attention worldwide. Alkaline phosphatase activity (APA) affects the biochemical cycles of phosphorus in the water, thereby affecting the proliferation and outbreak of cyanobacteria blooms. However, it is still unclear whether the complex composition of rainwater has a significant effect on the alkaline phosphatase activity. In this study, the effects of rainfall on Microcystis aeruginosa in Kunming were evaluated based upon changes in alkaline phosphatase activity, algal growth, and chlorophyll a. The results showed that the addition of rainwater brought about different changes in alkaline phosphatase activity, algal growth, and chlorophyll a. The general trend showed that a certain amount of rainwater (equivalent to light, moderate rain, and heavy levels) had a positive effect on the alkaline phosphatase activity, algal growth, and chlorophyll a in the cultivation system. Therefore, the following preliminary inference can be drawn: in the Kunming area, a certain amount of rainwater may promote the growth of blue-green algae, exacerbating an outbreak of cyanobacteria blooms.

Sediment Characteristics of Sewer in Different Functional Areas of Kunming

The problem of sediment deposition in urban sewer network in different levels, will not only reduce the sewer flow ability, but also release pollutants and generate secondary pollution. The impact of secondary pollution is more serious in the study area, Kunming, because of the combined sewer overflow in rainy season. In order to obtain the characteristics of the sewer sediments in Kunming, the sewer sediments from residential area, service area, cultural district, and business district were investigated and collected. The particle size, density, organic matter (VSS/TSS) and pollutant content of the sediments were analyzed in this study. The results showed that there were different characteristics for the sediments from different areas. The size of the sediments exhibited business district >cultural district >residential area >service area, and the D50 was concentrated in the 20 to 100 μm except the business district. As for VSS/TSS, the order was residential area >cultural district >business district >service area. It was negatively correlated with the dry density with the correlation index of R2=0.9827 and positively correlated with the water content. The contents of sediments showed significant differences in different functional areas. The size of COD presented residential area >cultural district >service area >business district, and the size of TN followed residential area >cultural district >business district >service area. As for TP, it exhibited residential area >service area >cultural district >business district. The COD, TN and TP were proportional to the population density of the area and TP was greatly influenced by sediment particle size. From the branch into the Sub-main sewer, COD and TN were irregular, and TP decreased slightly. TP mainly existed as particulate and was more likely to deposit onto the small particle. As for TN, there was no obvious rule about its distribution in different particle size sections. The pollution load was generally on the high side in Kunming. The content of heavy metals in business district was the highest among all functional areas, and the concentrations of Cu, Zn, Pb, Cd were 284.6, 786.4, 201.2, 2.54 mg·kg-1 respectively. The average contents of Cu, Zn, Pb, Cd in urban area were 2.2, 4.4, 2.5, 8.6 times than the background values. It is suggested to control Cd and Zn with priority.

Relationship among allergic rhinitis, regional pollens and meteorological conditions in Kunming area

To evaluate the species, quantity and diffusion of allergenic pollens as well as the relationship among allergic rhinitis (AR), pollen species and meteorological conditions in Kunming area. The exposure film was used to investigate the species of airborne pollen, the total number of these pollens during December 2009 to November 2010 by means of gravitational sedimentation, at the same time, AR patients were registered. The species of allergic pollen in Kunming area during the same period, and the statistic analysis was made with the meteorological elements, using the correlation analysis methods of Excel for data analysis. From December 2009 to November 2010, a total of 60 exposure films of pollen species was found, including 26 147 pollens. The annual airborne pollen showed two scattering peak, respectively: February to April and September to October; the number of advantage pollen was 17 species. The number of year-round drifting pollen was 13 species while 2 species showed two peaks on spring and autumn. There was another 26 new species added to the results of 2009-2010, compared with 1987-1989, while the original 12 species were not seen. The drifting peak was the same. The number of allergen intradermal tests (AIT) positive AR patients was positively correlated with 16 pollen species, respectively, oleaceae, alnus nepalensis, walnut, palm, pig weed, fennel, Amaranthaceae, artemisia, rosa, Albizia julibrissin Durazz, gramineae, castor, Fraxinus L, populus, Morus alba L, hemp humulus, (r value were 0.689 7, 0.550 1, 0.742 1, 0.755 2, 0.771 2, 0.663 3, 0.556 1, 0.568 3, 0.659 8, 0.607 4, 0.834 7, 0.664 3, 0.745 9, 0.634 7, 0.718 3, 0.777 2, all P < 0.05). The population of AIT positive AR patients was positively correlated with average temperature, average wind speed and other meteorological factors (r values were 0.552 0, 0.883 5, both P < 0.05), and was negatively correlated with average relative humidity (r = -0.714 7, P < 0.05). Kunming had a large number of airborne pollen species which showed two peaks annually, respectively, spring and autumn. The relationship among the number of AIT positive AR patients, the meteorological factors and the number of airborne pollen were close.

Urban-rural gradients of ecosystem services and the linkages with socioeconomics

The principle of urban-rural gradients can reveal the spatial variations of ecosystem services and socioeconomic dimensions. The interrelations between ecosystem services and socioeconomics have scarcely been considered in the context of urban-rural areas. We investigated the spatial gradients and the mutual linkages of several ecosystem services and socioeconomic variables in the urban-rural areas of Leipzig, Germany, and Kunming, China. The results showed some regularities in the spatial patterns of ecosystem services and socioeconomic dimensions in both study areas. Habitat quality and f-evapotranspiration of Leipzig and habitat quality of Kunming demonstrated apparent increasing trends along all gradient patterns. However, the other ecosystem services presented divergent spatial variabilities in different gradient patterns. Road density, urban fabric and population density showed identical declining trends in both case study areas. Differently, household size, housing area as well as unemployment rate in Leipzig presented inconsistent spatial dynamics with considerable fluctuations. With regard to the gradient interrelations, road density, urban fabric and population density were strongly correlated with most ecosystem services in both case study areas. In contrast, the gradients of household size, housing area and unemployment rate of Leipzig showed inconsistent correlations with the ecosystem services gradients. Our study provides evidence to the argument that typical patterns of ecosystem service gradients do not exist in different urban-rural areas.

Correlation between hepatitis C genotype, viral load, and peripheral blood T lymphocyte subsets in patients from the Kunming area

Correlation between hepatitis C genotype, viral load, and peripheral blood T lymphocyte subsets in patients from the Kunming area

Understanding Factors Affecting Frequency of Traffic Conflicts between Electric Bicycles and Motorized Vehicles at Signalized Intersections

The primary objective of this study was to identify factors influencing traffic conflicts between electric bicycles and motorized vehicles at signalized intersections. Data were collected at 20 sites in the Kunming area in China. Three predominant types of traffic conflicts, which accounted for more than 75% of the total conflicts at the selected sites, were identified. Conflict models were developed to relate the frequency of traffic conflicts to various explanatory variables. Three types of models were compared: the fixed-effect, the random-effect, and the random-parameter generalized linear regression models. It was found that the random-parameter models provided the best goodness of fit to field data. With analysis of the elasticity of the explanatory variables, it was concluded that motorized vehicles played a more important role in conflict occurrences at signalized intersections than did two-wheeled vehicles. The presence of scooter-style electric bicycles had a considerably negative influence on the safety of signalized intersections, whereas the presence of bicycle-style electric bicycles had a minor effect. The current traffic channelization and barrier between motorized vehicles and bicycle lanes significantly reduce traffic conflicts between two-wheeled and motorized vehicles at signalized intersections.

A Segmentation Algorithm for Remote Sensing Imaging Based on Edge and Heterogeneity of Objects

Image segmentation is the fundamental technology used in object-oriented remote sensing image analysis. To improve on the approach of object-oriented image analysis for the extraction of ground objects of interest, a segmentation algorithm for remote sensing images based on edge and heterogeneity of objects has been proposed in this paper. Canny algorithm combined with a mathematical morphology operator is used first to detect the edge information of a remote sensing image. Then, based on edge and heterogeneity of images, homogenous regions are obtained by Fractal Net Evolution approach. Finally, the edge information is used as a constrain in region merging, the final segmentation results are acquired. In this paper, QuickBird data from a certain area of Kunming have been tested and compared with a multi-resolution segmentation algorithm in the eCognition platform. The experiment results show that the method can segment the remote sensing images effectively and precisely.