Various Methods for Queue Length and Traffic Volume Estimation Using Probe Vehicle Trajectories

Probe vehicles, like mobile sensors, can provide rich information about traffic conditions in transportation networks. The rapid development of connected vehicle technology and the emergence of ride-hailing services have enabled the collection of a huge amount of trajectory data of the probe vehicles. Attribute to the scale and the accessibility, the trajectory data have become a potential substitute for the widely used fixed-location sensors in terms of the performance measures of the transportation networks. There has been some literature estimating traffic volume and queue length at signalized intersections using the trajectory data. However, some of the existing methods require the prior information about the distribution of queue lengths and the penetration rate of the probe vehicles, which might vary a lot both spatially and temporally and usually are not known in real life. Some other methods can only work when the penetration rate of the probe vehicles is sufficiently high. To overcome the limitations of the existing literature, this paper proposes a series of novel methods for queue length and traffic volume estimation. The validation results show that the methods are accurate enough for mid-term and long-term performance measures and traffic signal control, even when the penetration rate is very low. Therefore, the methods are ready for large-scale real-field applications.Comment: Transportation network sensing using probe vehicle trajectorie

Incidental terrestrial imagery for post disaster spatial data capture of debris flows

Consumer-grade digital imagery captured by non-experts has a great potential for DEM extraction. The portability of the equipment creates opportunities for data collection in difficult and inaccessible mountainous terrain. In this context it provides an important tool enabling rapid response post-disaster planning in regions affected by large scale natural hazard events. The potential of this methodology is illustrated by a case study of the large scale debris flow that killed several thousand people in the town of Zhouqu, China in August 2010. The case study briefly introduces the pertinent details of the debris flow event. Data collection, processing and representations are highlighted. It is concluded that the methodology can be beneficial for post-disaster planning, and that the relatively cheap instrument requirements and simple methodologies also provide an opportunity to involve local residents and municipal authorities for landscape monitoring in active terrains

Investigating slow-moving landslides in the Zhouqu region of China using InSAR time series

In the Zhouqu region (Gansu, China), landslide distribution and activity exploits geological weaknesses in the fault-controlled belt of low-grade metamorphic rocks of the Bailong valley and severely impacts lives and livelihoods in this region. Landslides reactivated by the Wenchuan 2008 earthquake and debris flows triggered by rainfall, such as the 2010 Zhouqu debris flow, have caused more than 1700 casualties and estimated economic losses of some US$0.4 billion. Earthflows presently cover some 79% of the total landslide area and have exerted a strong influence on landscape dynamics and evolution in this region. In this study, we use multi-temporal Advanced Land Observing Satellite and Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR) data and time series interferometric synthetic aperture radar to investigate slow-moving landslides in a mountainous region with steep topography for the period December 2007–August 2010 using the Small Baseline Subsets (SBAS) technique. This enabled the identification of 11 active earthflows, 19 active landslides with deformation rates exceeding 100 mm/year and 20 new instabilities added into the pre-existing landslide inventory map. The activity of these earthflows and landslides exhibits seasonal variations and accelerated deformation following the Wenchuan earthquake. Time series analysis of the Suoertou earthflow reveals that seasonal velocity changes are characterized by comparatively rapid acceleration and gradual deceleration with distinct kinematic zones with different mean velocities, although velocity changes appear to occur synchronously along the landslide body over seasonal timescales. The observations suggest that the post-seismic effects (acceleration period) on landslide deformation last some 6–7 months

Landslide research in China

On 9 April 2000, a 91 Mm3 rock avalanche occurred in Linzhi Prefecture, Tibet. The event was accompanied by a deafening noise, with the rock mass travelling from a maximum elevation of 5132 m and coming to a rest at an elevation of 2163 m. It formed a landslide dam in the Yigong Zangbo River of some 55 m height, impounding a reservoir of some 2 Gm3 for a period of 62 days after which it emptied in less than 12 h. This event was a forewarning of a period of frequent geological disasters in China during the start of the 21st century. The ensuing Wenchuan earthquake (surface-wave magnitude Ms 8.0; May 2008), Zhouqu debris flow (August 2010) and Ludian earthquake (Ms 6.7; August 2014) led to the Chinese Government renewing its campaign against geological disasters and it has since invested heavily in scientific research to guide efforts to mitigate the impact of such natural disasters. This thematic set on Landslide Research in China was initiated to highlight this research. This paper provides a brief review of three of the featured subjects and accompanies the five papers published in the thematic set. Large earthquakes severely affect the geological environment and also result in the potential for secondary disasters in the days, months and years that follow. There is continued debate on how quickly landscapes recover following a high-magnitude disturbance. Lin et al. (2006, 2009) studied the ChiChi earthquake of 1999 and found that 5 years after the earthquake the area experienced a relatively high number of landslides (including debris flows) followed by a trend of gradual decline. Hovius et al. (2011) concluded that it took c. 6 years for the landslide signal to return to pre-1999 levels. Other examples of long-term landscape recovery have been discussed by, for example, Nakamura et al. (2000) for the 1923 Ms 7.9 Kanto earthquake in Japan, and by Huang (2011) for the 2008 Ms 8.0 Wenchuan earthquake, China. The Wenchuan earthquake took place on 12 May 2008 in Sichuan Province, resulting in some 200 000 landslide events (Xu et al. 2013), and in the following years the province frequently experienced further landslide activity. According to the first author's statistics, the province experienced 668, 934, 2161, 1997 and 3147 geohazard events between 2008 and 2012. The enhanced landslide and debris-flow activity after the 2008 Wenchuan earthquake was highlighted in the Special Issue of Engineering Geology ‘The long-term geologic hazards in areas struck by large-magnitude earthquakes’ (2014, Volume 182, Part B)

Characterization of a neurotoxigenic Clostridium butyricum strain isolated from the food implicated in an outbreak of food-borne type E botulism

金沢大学大学院医学系研究科病態検査学Neurotoxigenic Clostridium butyricum was isolated from the food implicated in an outbreak of clinically diagnosed type E botulism in China. PCR assay showed that the isolate (LCL 155) contained the type E botulinum toxin gene. This appears to be the first report of neurotoxigenic C. butyricum causing food-borne botulism

Co-evolution of soil and water conservation policy and human–environment linkages in the Yellow River Basin since 1949

Policy plays a very important role in natural resource management as it lays out a government framework for guiding long-term decisions, and evolves in light of the interactions between human and environment. This paper focuses on soil and water conservation (SWC) policy in the Yellow River Basin (YRB), China. The problems, rural poverty, severe soil erosion, great sediment loads and high flood risks, are analyzed over the period of 1949–present using the Driving force–Pressure–State–Impact–Response (DPSIR) framework as a way to organize analysis of the evolution of SWC policy. Three stages are identified in which SWC policy interacts differently with institutional, financial and technology support. In Stage 1 (1949–1979), SWC policy focused on rural development in eroded areas and on reducing sediment loads. Local farmers were mainly responsible for SWC. The aim of Stage 2 (1980–1990) was the overall development of rural industry and SWC. A more integrated management perspective was implemented taking a small watershed as a geographic interactional unit. This approach greatly improved the efficiency of SWC activities. In Stage 3 (1991 till now), SWC has been treated as the main measure for natural resource conservation, environmental protection, disaster mitigation and agriculture development. Prevention of new degradation became a priority. The government began to be responsible for SWC, using administrative, legal and financial approaches and various technologies that made large-scale SWC engineering possible. Over the historical period considered, with the implementation of the various SWC policies, the rural economic and ecological system improved continuously while the sediment load and flood risk decreased dramatically. The findings assist in providing a historical perspective that could inform more rational, scientific and effective natural resource management going forwar

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts