scholarly journals Exploring Passengers’ Dependency Variety on Stations’ Functions in Urban Subway

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xia Zhao ◽  
Pengpeng Jiao ◽  
Yong Zhang ◽  
Chenjing Zhou

Urban subway is taken by people in different frequencies, thus leading them to present different dependency varieties on this mode. Yet, how those passengers who possess low dependency on urban subway travel is less investigated. Under this background, we propose a framework to uncover passengers’ dependency variety on stations’ functions in urban subway. To begin with, nine features regarding travel frequency and time are extracted from 100 million transaction records generated by 11.45 million passengers in a month. Thus, their travel dependency on urban subway is quantified. These features are clustered into 5 distinct levels via the k-means algorithm, before an inference of subway stations’ functions from 236,040 POI data sources via the LDA approach. In this way, passengers’ travel purposes can be identified. How passengers with different dependency levels behave in subway stations in space and time is further explored in a visualization way. The intuitive experimental results, validated by priori user experiences and land-use plan of Beijing, show that among the 5 levels of dependency varieties, passengers in the first two groups present a relatively strong dependency on urban subway. Meanwhile, passengers in the rest three groups possess a low dependency on urban subway and display extreme travel patterns in time and frequency, greatly increasing management difficulties for transit operators. Findings in this research help distinguish passengers with low levels of subway dependency and grasp how those passengers without striking dependency travel by subway and what for so that practitioners can conduct an accurate risk assessment on them.

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 334
Author(s):  
Juraj Lieskovský ◽  
Dana Lieskovská

This study compares different nationwide multi-temporal spatial data sources and analyzes the cropland area, cropland abandonment rates and transformation of cropland to other land cover/land use categories in Slovakia. Four multi-temporal land cover/land use data sources were used: The Historic Land Dynamics Assessment (HILDA), the Carpathian Historical Land Use Dataset (CHLUD), CORINE Land Cover (CLC) data and Landsat images classification. We hypothesized that because of the different spatial, temporal and thematic resolution of the datasets, there would be differences in the resulting cropland abandonment rates. We validated the datasets, compared the differences, interpreted the results and combined the information from the different datasets to form an overall picture of long-term cropland abandonment in Slovakia. The cropland area increased until the Second World War, but then decreased after transition to the communist regime and sharply declined following the 1989 transition to an open market economy. A total of 49% of cropland area has been transformed to grassland, 34% to forest and 15% to urban areas. The Historical Carpathian dataset is the more reliable long-term dataset, and it records 19.65 km2/year average cropland abandonment for 1836–1937, 154.44 km2/year for 1938–1955 and 140.21 km2/year for 1956–2012. In comparison, the Landsat, as a recent data source, records 142.02 km2/year abandonment for 1985–2000 and 89.42 km2/year for 2000–2010. These rates, however, would be higher if the dataset contained urbanisation data and more precise information on afforestation. The CORINE Land Cover reflects changes larger than 5 ha, and therefore the reported cropland abandonment rates are lower.


Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 38
Author(s):  
Nick Martin

Climate and land use and land cover (LULC) changes will impact watershed-scale water resources. These systemic alterations will have interacting influences on water availability. A probabilistic risk assessment (PRA) framework for water resource impact analysis from future systemic change is described and implemented to examine combined climate and LULC change impacts from 2011–2100 for a study site in west-central Texas. Internally, the PRA framework provides probabilistic simulation of reference and future conditions using weather generator and water balance models in series—one weather generator and water balance model for reference and one of each for future conditions. To quantify future conditions uncertainty, framework results are the magnitude of change in water availability, from the comparison of simulated reference and future conditions, and likelihoods for each change. Inherent advantages of the framework formulation for analyzing future risk are the explicit incorporation of reference conditions to avoid additional scenario-based analysis of reference conditions and climate change emissions scenarios. In the case study application, an increase in impervious area from economic development is the LULC change; it generates a 1.1 times increase in average water availability, relative to future climate trends, from increased runoff and decreased transpiration.


2021 ◽  
Vol 13 (4) ◽  
pp. 2077
Author(s):  
Mahnaz Sarlak ◽  
Laura Valeria Ferretti ◽  
Rita Biasi

About two billion rural individuals depend on agricultural systems associated with a high amount of risk and low levels of yield in the drylands of Asia, Africa, and Latin America. Human activities, climate change and natural extreme events are the most important drivers of desertification. This phenomenon has occurred in many regions of Iran, particularly in the villages in the periphery of the central desert of Iran, and has made living in the oases so difficult that the number of abandoned villages is increasing every year. Land abandonment and land-use change increase the risk of desertification. This study aims to respond to the research questions: (i) does the planning of green infrastructures on the desert margin affect the distribution and balance of the population? (ii) how should the green belt be designed to have the greatest impact on counteracting desertification?, and (iii) does the design of productive landscape provide the solution? Through a wide-ranging and comprehensive approach, this study develops different scenarios for designing a new form of green belt in order to sustainably manage the issues of environmental protection, agricultural tradition preservation and desertification counteraction. This study proposes a new-traditional greenbelt including small low-cost and low-tech projects adapted to rural scale.


Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 195 ◽  
Author(s):  
Konstantinos Kougioumoutzis ◽  
Ioannis P. Kokkoris ◽  
Maria Panitsa ◽  
Arne Strid ◽  
Panayotis Dimopoulos

Human-induced biodiversity decline has been on the rise for the past 250 years, due to various causes. What is equally troubling, is that we are unaware which plants are threatened and where they occur. Thus, we are far from reaching Aichi Biodiversity Target 2, i.e., assessing the extinction risk of most species. To that end, based on an extensive occurrence dataset, we performed an extinction risk assessment according to the IUCN Criteria A and B for all the endemic plant taxa occurring in Greece, one of the most biodiverse countries in Europe, in a phylogenetically-informed framework and identified the areas needing conservation prioritization. Several of the Greek endemics are threatened with extinction and fourteen endemics need to be prioritized, as they are evolutionary distinct and globally endangered. Mt. Gramos is identified as the most important conservation hotspot in Greece. However, a significant portion of the identified conservation hotspots is not included in any designated Greek protected area, meaning that the Greek protected areas network might need to be at least partially redesigned. In the Anthropocene era, where climate and land-use change are projected to alter biodiversity patterns and may force many species to extinction, our assessment provides the baseline for future conservation research, ecosystem services maintenance, and might prove crucial for the timely, systematic and effective aversion of plant extinctions in Greece.


2005 ◽  
Vol 5 (2) ◽  
pp. 123-134 ◽  
Author(s):  
R. Miller ◽  
B. Whitehill ◽  
D. Deere

This paper comments on the strengths and weaknesses of different methodologies for risk assessment, appropriate for utilisation by Australian Water Utilities in risk assessment for drinking water source protection areas. It is intended that a suggested methodology be recommended as a national approach to catchment risk assessment. Catchment risk management is a process for setting priorities for protecting drinking water quality in source water areas. It is structured through a series of steps for identifying water quality hazards, assessing the threat posed, and prioritizing actions to address the threat. Water management organisations around Australia are at various stages of developing programs for catchment risk management. While much conceptual work has been done on the individual components of catchment risk management, work on these components has not previously been combined to form a management tool for source water protection. A key driver for this project has been the requirements of the National Health and Medical Research Council Framework for the Management of Drinking Water Quality (DWQMF) included in the draft 2002 Australian Drinking Water Guidelines (ADWG). The Framework outlines a quality management system of steps for the Australian water industry to follow with checks and balances to ensure water quality is protected from catchment to tap. Key steps in the Framework that relate to this project are as follows: Element 2 Assessment of the Drinking Water Supply System• Water Supply System analysis• Review of Water Quality Data• Hazard Identification and Risk Assessment Element 3 Preventive Measures for Drinking Water Quality Management• Preventive Measures and Multiple Barriers• Critical Control Points This paper provides an evaluation of the following risk assessment techniques: Hazard Analysis and Critical Control Points (HACCP); World Health Organisation Water Safety Plans; Australian Standard AS 4360; and The Australian Drinking Water Guidelines – Drinking Water Quality Management Framework. These methods were selected for assessment in this report as they provided coverage of the different approaches being used across Australia by water utilities of varying: scale of water management organisation; types of water supply system management; and land use and activity-based risks in the catchment area of the source. Initially, different risk assessment methodologies were identified and reviewed. Then examples of applications of those methods were assessed, based on several key water utilities across Australia and overseas. Strengths and weaknesses of each approach were identified. In general there seems some general grouping of types of approaches into those that: cover the full catchment-to-tap drinking water system; cover just the catchment area of the source and do not recognise downstream barriers or processes; use water quality data or land use risks as a key driving component; and are based primarily on the hazard whilst others are based on a hazardous event. It is considered that an initial process of screening water quality data is very valuable in determining key water quality issues and guiding the risk assessment, and to the overall understanding of the catchment and water source area, allowing consistency with the intentions behind the ADWG DWQM Framework. As such, it is suggested that the recommended national risk assessment approach has two key introductory steps: initial screening of key issues via water quality data, and land use or activity scenario and event-based HACCP-style risk assessment. In addition, the importance of recognising the roles that uncertainty and bias plays in risk assessments was highlighted. As such it was deemed necessary to develop and integrate uncertainty guidelines for information used in the risk assessment process. A hybrid risk assessment methodology was developed, based on the HACCP approach, but with some key additions and modifications to make it applicable to varying catchment risks, water supply operation needs and environmental management processes.


Parasitology ◽  
1999 ◽  
Vol 117 (7) ◽  
pp. 205-212 ◽  
Author(s):  
C. J. GIBSON ◽  
C. N. HAAS ◽  
J. B. ROSE

Throughout the past decade much research has been directed towards identifying the occurrence, epidemiology, and risks associated with waterborne protozoa. While outbreaks are continually documented, sporadic cases of disease associated with exposure to low levels of waterborne protozoa are of increasing concern. Current methodologies may not be sensitive enough to define these low levels of disease. However, risk assessment methods may be utilised to address these low level contamination events. The purpose of this article is to provide an introduction to microbial risk assessment for waterborne protozoa. Risk assessment is a useful tool for evaluating relative risks and can be used for development of policies to decrease risks. Numerous studies have been published on risk assessment methods for pathogenic protozoa including Cryptosporidium and Giardia. One common notion prevails: microbial risk assessment presents interesting complications to the traditional chemical risk assessment paradigm. Single microbial exposures (non-threshold) are capable of causing symptomatic illness unlike traditional chemical exposures, which require a threshold to be reached. Due to the lack of efficient recovery and detection methods for protozoa, we may be underestimating the occurrence, concentration and distribution of these pathogenic micro-organisms. To better utilize the tool of microbial risk assessment for risk management practices, future research should focus in the area of exposure assessment.


Author(s):  
David Song ◽  
Ashish Gupta ◽  
Chia-Pin Chiu

This paper presents the current-carrying-capacity (CCC) characterization of a land-grid-array type microprocessor socket. This CCC study has been performed using both computational modeling and experiments using infrared camera. A subsequent risk assessment was performed against the maximum allowed temperature at the point of pressure contact of socket pin for the use-condition socket pin current and motherboard temperature. The results from the modeling and the experimental results are compared.


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