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Leading Pattern of Spring Drought Variability over East Asia and Associated Drivers
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作者 赵庆红 杨崧 +1 位作者 田红瑛 邓开强 《Journal of Tropical Meteorology》 SCIE 2024年第1期1-10,共10页
Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their ... Drought events have become more frequent and intense over East Asia in recent decades,leading to huge socioeconomic impacts.Although the droughts have been studied extensively by cases or for individual regions,their leading variability and associated causes remain unclear.Based on the Standardized Precipitation Evapotranspiration Index(SPEI)and ERA5 reanalysis product from 1979 to 2020,this study evealuates the severity of spring droughts in East Asia and investigates their variations and associated drivers.The results indicate that North China and Mongolia have experienced remarkable trends toward dryness during spring in recent decades,while southwestern China has witnessed an opposite trend toward wetness.The first Empirical Orthogonal Function mode of SPEI variability reveals a similar seesawing pattern,with more severe dryness in northwestern China,Mongolia,North China,South Korea,and Japan but increased wetness in Southwestern China and southeast Asia.Further investigation reveals that the anomalously dry(wet)surface in North(Southwestern)China is significantly associated with anomalously high(low)temperature,less(more)precipitation,and reduced(increased)soil moisture during the previous winter and early spring,regulated by an anomalous anticyclone(cyclone)and thus reduced(increased)water vapor convergence.The spring dry-wet pattern in East Asia is also linked to cold sea surface temperature anomalies in the central-eastern Pacific.The findings of this study have important implications for improving the prediction of spring drought events in East Asia. 展开更多
关键词 DROUGHT leading pattern East Asia spring drivers
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Knowledge, Attitudes and Practices Relating to HIV among Motorbike Taxi Drivers in Parakou, Benin, in 2021
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作者 Luc Béhanzin Anicette Yénoukounmè Mahoutin Akodjetin +6 位作者 Yessito Corine Nadège Houéhanou-Sonou Virginie Mongbo Phinées Adégbola Menakpo Ferdinand Adounkpè Maurice Togbédji Agonnoudé David Houéto Thierry Adoukonou 《Open Journal of Epidemiology》 2024年第2期260-272,共13页
Background and Objective: HIV infection is a major global Public Health threat worldwide, particularly in Sub-Saharan Africa of which Benin. The level of knowledge determines the attitudes and behaviors of the populat... Background and Objective: HIV infection is a major global Public Health threat worldwide, particularly in Sub-Saharan Africa of which Benin. The level of knowledge determines the attitudes and behaviors of the populations towards this infection. The study objective was to assess knowledge, attitudes and practices related to HIV infection among motorbike taxi drivers (MTD) in Parakou in 2021. Methods: This was a descriptive cross-sectional study targeting MTD in Parakou in 2021. Participants were selected by cluster sampling. Pretested Digitized questionnaire using KoboCollect<sup>@</sup> applicationserved as a data collection tool. Knowledge, attitudes and practices variable were treated on a score scale. A knowledge score was considered to reflect a good knowledge of HIV if at least two-thirds of the knowledge statements had been correctly answered provided the subject recognized the sexual route as one of modes of HIV transmission, identified at least one preventive measure and meant the incurability of the disease. Quantitative and qualitative variables were appropriately described using the EPI Info 7.1.3.3 software. The participant was classified at positive attitude/practice for HIV prevention, when it has a score of at least 80% and suggests a good preventive measure face a risk of exposure to HIV. Results: A total of 374 subjects were recruited into the study. The mean age was 31.51 ± 7.76 years. Most participants (86.06%) had good knowledge of condom use as an HIV prevention method. The sources of information mentioned were mainly the media (77.07%), relatives or friends (63.38%), and field-workers from non-governmental organizations (37.26%). Routine HIV testing was 50.53%. Among participants, 76.10% reported at least two different sexual partners. Condom use was 59.18 % during the casual sexual intercourse. Within the client-provider relationship with female sex workers, 33.17% had had sexual intercourse with them. The sexual route was the most cited (92.99%), and 90.23% stated that HIV infection can be stabilized by medication in a health structure. Conclusion: The level of knowledge of motorbike taxi drivers in Parakou does not match their behavior with regard to HIV prevention. Appropriate strategies are needed to develop prevention skills in this population. To effectively comb at HIV, it will be necessary to strengthen the targeted HIV preventive interventions at key and bridge populations including motorbike taxi drivers in Benin. 展开更多
关键词 KNOWLEDGE PRACTICE HIV Motorbike Taxi drivers BENIN
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Seroprevalence Survey of HIV and Hepatitis B Virus and Behavioral Characteristics among Heavy Truck Drivers along Port Sudan-Khartoum Highways
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作者 Sara S. Osman Adam A. Mattar Omnia M. Hamid 《Open Journal of Medical Microbiology》 2024年第1期11-22,共12页
The prevalence of human immunodeficiency virus (AIDS) and hepatitis B virus among heavy truck drivers and their assistants has been well documented globally in correlation with their behavioral characteristics. The pr... The prevalence of human immunodeficiency virus (AIDS) and hepatitis B virus among heavy truck drivers and their assistants has been well documented globally in correlation with their behavioral characteristics. The present study aimed to screen for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and behavioral characteristics among heavy truck drivers in Port Sudan. A cross-sectional study was conducted on 274 heavy truck drivers and their assistants who used the highway Port Sudan-Khartoum in Port Sudan city during 2019-2021. Data on behavioral characteristics and substance use habits were collected using a structured questionnaire, and an ELISA test was used to screen for HIV and HBV infections in the study participants. The chi-square test, odds ratio, and confidence intervals were used to find the association between behavioral characteristics and seropositive HIV/HBV. Of the 274 enrolled participants, the seroprevalence rates of HIV were 2.7% and HBV was 23.7%. Ninety-four (34.3%) of them had a history of high-risk sexual behavior outside of marriage;only two (0.7%) used condoms;14.2% of participants reported alcohol use;and 1.1% reported drug use. Univariate analysis revealed that having a sex history outside of marriage with ≥1 sex partner and never using a condom with a spouse or casual partner were significant risk factors for HIV and HBV among drivers. Fortunately, we found that most of the drivers reported low alcohol and drug use. Concerning this study, the seroprevalence of HIV and HBV is highly associated with a history of having sex outside of marriage and sexual behavior among truck drivers and assistances. Additional studies are needed to further investigate other STIs and behavioral characteristics associated with factors in truck drivers/assistance in different truck stop regions in Sudan. 展开更多
关键词 Sexual Transmitted Infection Port Sudan Truck drivers/Assistance
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A road hypnosis identification method for drivers based on fusion of biological characteristics
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作者 Longfei Chen Jingheng Wang +6 位作者 Xiaoyuan Wang Bin Wang Han Zhang Kai Feng Gang Wang Junyan Han Huili Shi 《Digital Transportation and Safety》 2024年第3期144-154,共11页
Risky driving behaviors,such as driving fatigue and distraction have recently received more attention.There is also much research about driving styles,driving emotions,older drivers,drugged driving,DUI(driving under t... Risky driving behaviors,such as driving fatigue and distraction have recently received more attention.There is also much research about driving styles,driving emotions,older drivers,drugged driving,DUI(driving under the influence),and DWI(driving while intoxicated).Road hypnosis is a special behavior significantly impacting traffic safety.However,there is little research on this phenomenon.Road hypnosis,as an unconscious state,is can frequently occur while driving,particularly in highly predictable,monotonous,and familiar environments.In this paper,vehicle and virtual driving experiments are designed to collect the biological characteristics including eye movement and bioelectric parameters.Typical scenes in tunnels and highways are used as experimental scenes.LSTM(Long Short-Term Memory)and KNN(K-Nearest Neighbor)are employed as the base learners,while SVM(Support Vector Machine)serves as the meta-learner.A road hypnosis identification model is proposed based on ensemble learning,which integrates bioelectric and eye movement characteristics.The proposed model has good identification performance,as seen from the experimental results.In this study,alternative methods and technical support are provided for real-time and accurate identification of road hypnosis. 展开更多
关键词 Road hypnosis State identification Active safety drivers Intelligent vehicles
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Statistical Analysis of Accident Proneness of Drivers
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作者 S.V.Gerus 《Journal of Traffic and Transportation Engineering》 2024年第2期81-91,共11页
A mathematical model describing the risks of road accidents has been built on the basis of statistical data of drivers’ accident rate. It has been revealed that drivers can be divided by the degree of their accident ... A mathematical model describing the risks of road accidents has been built on the basis of statistical data of drivers’ accident rate. It has been revealed that drivers can be divided by the degree of their accident proneness into four categories with sharply differing probabilities of road accidents. It has been shown that there is a possibility of classification of drivers in accordance with specified categories. 展开更多
关键词 ACCIDENT PROBABILITY driver CATEGORY classification proneness
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Lattice models of traffic flow considering drivers' delay in response 被引量:3
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作者 祝会兵 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1322-1327,共6页
This paper proposes two lattice traffic models by taking into account the drivers' delay in response. The lattice versions of the hydrodynamic model are described by the differential-difference equation and differenc... This paper proposes two lattice traffic models by taking into account the drivers' delay in response. The lattice versions of the hydrodynamic model are described by the differential-difference equation and difference-difference equation, respectively. The stability conditions for the two models are obtained by using the linear stability theory. The modified KdV equation near the critical point is derived to describe the traffic jam by using the reductive perturbation method, and the kink-antikink soliton solutions related to the traffic density waves are obtained. The results show that the drivers' delay in sensing headway plays an important role in jamming transition. 展开更多
关键词 lattice hydrodynamic model traffic jams analytical method drivers' delay in response
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Abiotic and biotic drivers of species diversity in understory layers of cold temperate coniferous forests in North China 被引量:10
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作者 Hui Wang Mengtao Zhang Hongwei Nan 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第6期2213-2225,共13页
Understory plants are important components of forest ecosystems and play a crucial role in regulating community structures,function realization,and community succession.However,little is known about how abiotic and bi... Understory plants are important components of forest ecosystems and play a crucial role in regulating community structures,function realization,and community succession.However,little is known about how abiotic and biotic drivers affect the diversity of understory species in cold temperate coniferous forests in the semiarid climate region of North China.We hypothesized that(1)topographic factors are important environmental factors affecting the distribution and variation of understory strata,and(2)different understory strata respond differently to environmental factors;shrubs may be significantly affected by the overstory stratum,and herbs may be more affected by surface soil conditions.To test these hypotheses,we used the boosted regression tree method to analyze abiotic and biotic environmental factors that influence understory species diversity,using data from 280 subplots across 56 sites in cold temperate coniferous forests of North China.Elevation and slope aspect were the dominant and indirect abiotic drivers affecting understory species diversity,and individual tree size inequality(DBH variation)was the dominant biotic driver of understory species diversity;soil water content was the main edaphic factors affecting herb layers.Elevation,slope aspect,and DBH variation accounted for 36.4,14.5,and 12.1%,respectively,of shrub stratum diversity.Shrub diversity decreased with elevation within the range of altitude of this study,but increased with DBH variation;shrub diversity was highest on north-oriented slopes.The strongest factor affecting herb stratum species diversity was slope aspect,accounting for 25.9%of the diversity,followed by elevation(15.7%),slope(12.2%),and soil water content(10.3%).The highest herb diversity was found on southeast-oriented slopes and the lowest on northeast-oriented slopes;herb diversity decreased with elevation and soil water content,but increased with slope.The results of the study provide a reference for scientific management and biodiversity protection in cold temperate coniferous forests of North China. 展开更多
关键词 ABIOTIC and biotic drivers Cold TEMPERATE CONIFEROUS forests North China SEMI-ARID region UNDERSTORY species diversity
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Transboundary water vulnerability and its drivers in China 被引量:22
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作者 冯彦 何大明 《Journal of Geographical Sciences》 SCIE CSCD 2009年第2期189-199,共11页
Competitive use of transboundary freshwater resources is becoming one of the key factors influencing regional peace and political relationship among states.In China, 18 major international river basins are concentrate... Competitive use of transboundary freshwater resources is becoming one of the key factors influencing regional peace and political relationship among states.In China, 18 major international river basins are concentrated in three regions, of which the total annual outflow at the border is 7320×108 m3, occupying 26.8% of the total annual runoff of China, and the inflow at the border is only 172×108 m3.In this paper, we analyzed the major drivers affecting shared water vulnerability in China, namely:(1) changes in physical conditions affecting the availability of water;(2) competing objectives between economic development and ecological conservation;(3) lack of emergency response mechanisms;(4) unsound administrative institutions;and(5) shortcomings in the development of regional cooperation based on transboundary waters.We concluded by identifying four pathways for reducing vulnerability:(1) encouraging scientific research cooperation;(2) constructing information-sharing channels;(3) establishing early-warning mechanisms;and(4) promoting further coordination and negotia-tion. 展开更多
关键词 transboundary water VULNERABILITY drivers
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Influences of Switching Jitter on the Operational Performances of Linear Transformer Drivers-Based Drivers 被引量:2
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作者 刘鹏 孙凤举 +3 位作者 魏浩 王志国 尹佳辉 邱爱慈 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第4期347-352,共6页
A whole circuit model of a linear transformer drivers (LTD) module composed of 60 cavities in series was developed in the software PSPICE to study the influence of switching jitter on the operational performances of... A whole circuit model of a linear transformer drivers (LTD) module composed of 60 cavities in series was developed in the software PSPICE to study the influence of switching jitter on the operational performances of LTDs. In the model, each brick in each cavity is capable of operating with jitter in its switch. Additionally, the manner of triggering cables entering into cavities was considered. The performances of the LTD module operating with three typical cavity-triggering sequences were simulated and the simulation results indicate that switching jitter affects slightly the peak and starting time of the output current pulse. However, the enhancement in switching jitter would significantly lengthen the rise time of the output current pulse. Without considering other factors, a jitter lower than 10 ns may be necessary for the switches in the LTD module to provide output current parameters with an acceptable deviation. 展开更多
关键词 linear transformer drivers (LTDs) circuit model pulsed power transmission line JITTER trigger delay
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Heterogeneous traffic flow modeling with drivers’ timid and aggressive characteristics 被引量:2
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作者 Cong Zhai Weitiao Wu Songwen Luo 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第10期219-230,共12页
The driver’s characteristics(e.g.,timid and aggressive)has been proven to greatly affect the traffic flow performance,whereas the underlying assumption in most of the existing studies is that all drivers are homogene... The driver’s characteristics(e.g.,timid and aggressive)has been proven to greatly affect the traffic flow performance,whereas the underlying assumption in most of the existing studies is that all drivers are homogeneous.In the real traffic environment,the drivers are distinct due to a variety of factors such as personality characteristics.To better reflect the reality,we introduce the penetration rate to describe the degree of drivers’heterogeneity(i.e.,timid and aggressive),and proceed to propose a generalized heterogeneous car-following model with different driver’s characteristics.Through the linear stability analysis,the stability conditions of the proposed heterogeneous traffic flow model are obtained based on the perturbation method.The impacts of the penetration rate of drivers with low intensity,the average value and standard deviation of intensity parameters characterizing two types of drivers on the stability of traffic flow are analyzed by simulation.Results show that higher penetration of aggressive drivers contributes to traffic flow stability.The average value has a great impact on the stability of traffic flow,whereas the impact of the standard deviation is trivial. 展开更多
关键词 heterogeneous car-following model driver characteristic penetration rate STABILITY
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Numerical Analysis of the Output-Pulse Shaping Capability of Linear Transformer Drivers 被引量:2
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作者 刘鹏 孙风举 +1 位作者 尹佳辉 邱爱慈 《Plasma Science and Technology》 SCIE EI CAS CSCD 2011年第2期246-251,共6页
Output-pulse shaping capability of a linear transformer driver (LTD) module under different conditions is studied, by conducting the whole circuit model simulation by using the PSPICE code. Results indicate that a h... Output-pulse shaping capability of a linear transformer driver (LTD) module under different conditions is studied, by conducting the whole circuit model simulation by using the PSPICE code. Results indicate that a higher impedance profile of the internal transmission line would lead to a wider adjustment range for the output current rise time and a narrower adjustment range for the current peak. The number of cavities in series has a positive effect on the output- pulse shaping capability of LTD. Such an improvement in the output-pulse shaping capability can primarily be ascribed to the increment in the axial electric length of LTD. For a triggering time interval longer than the time taken by a pulse to propagate through the length of one cavity, the output parameters of LTD could be improved significantly. The present insulating capability of gas switches and other elements in the LTD cavities may only tolerate a slightly longer deviation in the triggering time interval. It is feasible for the LTD module to reduce the output current rise time, though it is not useful to improve the peak power effectively. 展开更多
关键词 linear transformer driver (LTD) circuit model pulsed power transmission line impedance profile trigger delay
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Fourth Industrial Revolution:Technological Drivers,Impacts and Coping Methods 被引量:6
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作者 LI Guoping HOU Yun WU Aizhi 《Chinese Geographical Science》 SCIE CSCD 2017年第4期626-637,共12页
The world is marching into a new development period when the digital technology,physical technology,and biological technology have achieved an unprecedented development respectively in their own fields,and at the same... The world is marching into a new development period when the digital technology,physical technology,and biological technology have achieved an unprecedented development respectively in their own fields,and at the same time their applications are converging greatly.These are the three major technological drivers for the Fourth Industrial Revolution.This paper discusses the specific technology niches of each kind technological driver behind the Fourth Industrial Revolution,and then evaluates impacts of the Fourth Industrial Revolution on global industrial,economic,and social development.At last this paper proposes possible measures and policies for both firms and governments to cope with the changes brought by the Fourth Industrial Revolution. 展开更多
关键词 Fourth Industrial Revolution technological drivers global impacts firm-level adjustments government policies
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Land cover change in different altitudes of Guizhou-Guangxi karst mountain area, China: patterns and drivers 被引量:6
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作者 CHEN Tian-tian PENG Li +1 位作者 LIU Shao-quan WANG Qiang 《Journal of Mountain Science》 SCIE CSCD 2017年第9期1873-1888,共16页
Topography, especially altitude, will influence the way, process and characteristics of land cover changes in mountainous area, simultaneously, the vertical difference of land cover changes will affect soil quality an... Topography, especially altitude, will influence the way, process and characteristics of land cover changes in mountainous area, simultaneously, the vertical difference of land cover changes will affect soil quality and regional ecological environment. Therefore, the gradient relationship analysis between land cover changes and altitude is very important for regional sustainability. This study investigated land cover dynamics based on land cover data from a typical mountainous area in the Guizhou-Guangxi karst mountain area, China, in 2000 and 2010, then explored the relationship between altitude and land cover change and analyzed different drivers of land cover change at different altitudes. Our findings are as follows. 1) From 2000 to 2010, the total area of land cover transition was 7167.04 km^2 or 2.8% of the region. The increasing area of build-up land(926.23 km^2) was larger than that of forest(859.38 km^2), suggesting that the urban construction speed was higher than that of reforestation. 2) Intensity of land cover transition in northwestern Guizhou-Guangxi karst mountain area was much larger than that of southeast part and their transition trend was also significantly different, which was consistent with regional population and economy. 3) Human activity was the most dramatic at altitudes between 0–500 m. For 500–1000 m, grassland mainly converted to forest and build-up land. Area of land cover transition was the greatest between 1000–1500 m, while above 1500 m, the transition of grassland was the most obvious. 4) The drivers of land cover change varied. Land cover change was positively correlated with gross domestic product and population density but was inversely related to relief amplitude. There were correlations between land cover change and distance to roads and rivers, and their correlations varied with altitude. By revealing patterns and causes of land cover changes in different altitudes, we hope to understand the vertical dependence of land cover changes, so as to improve land productivity and protect land ecological environment scientifically. 展开更多
关键词 Land cover change Vertical difference drivers Regional sustainability Guizhou-Guangxi karst mountain area
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Drivers of Regional Environmental Pollution Load and Zoning Control:A Case Study of the Yangtze River Economic Belt,China 被引量:1
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作者 ZHOU Kan WU Jianxiong +1 位作者 FAN Jie LIU Hanchu 《Chinese Geographical Science》 SCIE CSCD 2022年第1期31-48,共18页
The high environmental pollution load caused by the massive pollutant emissions and the accumulation of endogenous and cross-regional pollution has become an important obstacle to the current ecological civilization c... The high environmental pollution load caused by the massive pollutant emissions and the accumulation of endogenous and cross-regional pollution has become an important obstacle to the current ecological civilization construction in the Yangtze River Economic Belt(YREB)in China.Taking the YREB as an example,by using four environmental pollutant emission indicators,including chemical oxygen demand(COD),ammonia nitrogen(NH_(3)-N),sulfur dioxide(SO_(2)),and nitrogen oxides(NO_(x)),this paper established an environmental pollution load index(EPLI)based on the entropy-based measurement.Moreover,the Spatial Durbin Model was used to quantitatively analyze the drivers and spatial effects of environmental pollution load.Finally,specific scientific references were provided for formulating environmental regulations of pollution source control in the YREB.The results showed that:1)During2011-2015,the EPLI in the YREB was reduced significantly and the environmental pollution load increased from upstream to downstream.Among them,the pollution load levels in the Upper Mainstream subbasin,Taihu Lake subbasin,and Lower Mainstream subbasin were the most prominent.2)The environmental pollution load situation in the YREB was generally stable and partially improved.High load level areas were mainly concentrated in the Yangtze River Delta Region and the provincial borders in upstream,midstream,and downstream areas.The high load level areas already formed in Chengdu and Chongqing were also the key regulatory points in the future.3)The degree of local environmental pollution load was apparently affected by the adjacent cities.The population size,industrialization level,and the fiscal decentralization not only drove the increase of the local environmental pollution load level,but also affected the adjacent areas through the spatial spillover effects.The land development intensity mainly drove the increase in the local EPLI in the YREB.While factors such as economic development level and agricultural economic share could only act on the environmental pollution load process in adjacent cities.4)According to the differentiation characteristics of drivers of each city,the YREB was divided into seven zones based on k-medoids cluster method,and targeted zoning control policy recommendations for alleviating environmental pollution load in the YREB were proposed. 展开更多
关键词 environmental pollution load drivers spatial effects Spatial Durbin Model Yangtze River Economic Belt
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The Extent and Drivers of Deforestation and Forest Degradation in Masito-Ugalla Ecosystem, Kigoma Region, Tanzania 被引量:2
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作者 John E. Makunga Salome B. Misana 《Open Journal of Forestry》 2017年第2期285-305,共21页
Deforestation and forest degradation has been observed to be rampant in Masito-Ugalla ecosystem, Kigoma Region, western part of Tanzania. This paper therefore, intended to assess the extent of deforestation and forest... Deforestation and forest degradation has been observed to be rampant in Masito-Ugalla ecosystem, Kigoma Region, western part of Tanzania. This paper therefore, intended to assess the extent of deforestation and forest degradation in the area, and to determine their causes. A total of 101 respondents were considered as the sample size for this study. The methods used for data collection were household questionnaire interviews, in-depth interviews, focus group discussions, analysis of satellite images and direct observation. The findings indicated that deforestation was occurring in the study area. Satellite data revealed diminished closed woodland, bushed grassland, forest and thickets between 1990 and 2014. On the contrary, settlement area, cultivated land and open woodland had increased during the same time frame. Proximate factors causing deforestation and forest degradation included agricultural expansion, wood extraction and expansion of settlement area. Underlying factors included population growth, poverty, poor levels of education, lack of employment, corruption and embezzlement of public funds by politicians and senior government officials;and high demand for fuel-wood. Biophysical drivers like incidences of unplanned wildfires and socio trigger events notably civil strife were also important. In order to minimize the problem and based on the factors augmenting deforestation and forest degradation in the Masito-Ugalla ecosystem and their coupled negative consequences, effective environmental conservation education, increased patrols, effective law enforcement and provision of alternative energy sources are necessary. 展开更多
关键词 DEFORESTATION FOREST DEGRADATION drivers of DEFORESTATION Masito-Ugalla ECOSYSTEM
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Deforestation Trends and Spatial Modelling of its Drivers in the Dry Temperate Forests of Northern Pakistan–A Case Study of Chitral 被引量:3
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作者 Khuram Shehzad Faisal M.Qamer +2 位作者 MSR Murthy Sawaid Abbas Laxmi D.Bhatta 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1192-1207,共16页
Deforestation is a major environmental challenge in the mountain areas of Pakistan. The study assessed trends in the forest cover in Chitral tehsil over the last two decades using supervised land cover classification ... Deforestation is a major environmental challenge in the mountain areas of Pakistan. The study assessed trends in the forest cover in Chitral tehsil over the last two decades using supervised land cover classification of Landsat TM satellite images from 1992, 2000, and 2009, with a maximum likelihood algorithm. In 2009, the forest cover was 10.3% of the land area of Chitral(60,000 ha). The deforestation rate increased from 0.14% per annum in 1992–2000 to 0.54% per annum in 2000–2009, with 3,759 ha forest lost over the 17 years. The spatial drivers of deforestation were investigated using a cellular automaton modelling technique to project future forest conditions. Accessibility(elevation, slope), population density, distance to settlements, and distance to administrative boundary were strongly associated with neighbourhood deforestation. A model projection showed a further loss of 23% of existing forest in Chitral tehsil by 2030, and degradation of 8%, if deforestation continues at the present rate. Arandu Union Council, with 2212 households, will lose 85% of its forest. Local communities have limited income resources and high poverty and are heavily dependent on non-timber forest products for their livelihoods. Continued deforestation will further worsen their livelihood conditions, thus improved conservation efforts are essential. 展开更多
关键词 Remote sensing drivers of deforestation Cellular automata
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Analyzing Drivers’ Mental Patterns Using Q-Methodology 被引量:2
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作者 Abbas Sheykhfard Farshid Reza Haghighi +1 位作者 Mostafa Soltaninejad Ali Karji 《Journal of Transportation Technologies》 2020年第2期169-181,共13页
The human factor is the most important cause of road accidents. Investigating the drivers’ mental patterns can lead to a better understanding of the factors that affect drivers to make a mistake and thus increase the... The human factor is the most important cause of road accidents. Investigating the drivers’ mental patterns can lead to a better understanding of the factors that affect drivers to make a mistake and thus increase the likelihood of an accident. In this study, mental patterns of drivers as a human characteristic are determined through a questionnaire survey. To do this, 166 participants (18 - 65 years) were asked to express their opinion on the possible effect of 25 factors on the occurrence of accidents. These factors were selected through the investigation of the accident database during the last three years in different areas of the case study. To analyze the data extracted from the survey, Q-methodology was used. The results of the factor analysis showed that there are 5 mental patterns among the participants. Based on the driver’s opinion, human factors and road conditions were the most and least influential accident-generating items, respectively. The most significant reason for accidents determined by drivers was human errors including 1) unauthorized overtaking, 2) unauthorized speed, 3) driver distractions (such as cell phone), and 4) driver physical disability (such as visual impairment). Moreover, the failure of the vehicle was mostly reported as another influential contributor to accidents. It is worth mentioning that the results of this study can be used to minimize accidents resulted from drivers’ behavioral errors by suggesting strategies for enhancing their performance through new manuals which is a step towards a safer road. 展开更多
关键词 Human FACTOR driver MENTAL Pattern Q-METHODOLOGY FACTOR Analysis QUESTIONNAIRE
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Optical Diagnostics of Multi-Gap Gas Switches for Linear Transformer Drivers 被引量:1
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作者 盛亮 李阳 +7 位作者 孙铁平 丛培天 张美 彭博栋 赵吉祯 岳志勤 魏福利 袁媛 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第7期677-682,共6页
The trigger characteristics of a multi-gap gas switch with double insulating layers,a square-groove electrode supporter and a UV pre-ionizing structure are investigated aided by a high sensitivity fiber-bundle array d... The trigger characteristics of a multi-gap gas switch with double insulating layers,a square-groove electrode supporter and a UV pre-ionizing structure are investigated aided by a high sensitivity fiber-bundle array detector, a UV fiber detector, and a framing camera, in addition to standard electrical diagnostics. The fiber-bundle-array detector is used to track the turn-on sequence of each electrode gap at a timing precision of 0.6 ns. Each fiber bundle, including five fibers with different azimuth angles, aims at the whole emitting area of each electrode gap and is fed to a photomultiplier tube. The UV fiber detector with a spectrum response of 260-320 nm,including a fused-quartz fiber of 200 μm in diameter and a solar-blinded photomultiplier tube, is adopted to study the effect of UV pre-ionizing on trigger characteristics. The framing camera,with a capacity of 4 frames per shot and an exposure time of 5 ns, is employed to capture the evolution of channel arcs. Based on the turn-on light signal of each electrode gap, the breakdown delay is divided into statistical delay and formative delay. A decrease in both of them, a smaller switch jitter and more channel arcs are observed with lower gas pressure. An increase in trigger voltage can reduce the statistical delay and its jitter, while higher trigger voltage has a relatively small influence on the formative delay and the number of channel arcs. With the UV pre-ionizing structure at 0.24 MPa gas pressure and 60 kV trigger voltage, the statistical delay and its jitter can be reduced by 1.8 ns and 0.67 ns, while the formative delay and its jitter can only be reduced by 0.5 ns and 0.25 ns. 展开更多
关键词 optical diagnostics multi-gap gas switches linear transformer driver
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Drivers of Change in Estuarine and Coastal Marine Environments: An Overview 被引量:1
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作者 Michael J. Kennish 《Open Journal of Ecology》 2021年第3期224-239,共16页
Anthropogenic climate and non-climate drivers of change are causing significant impacts on estuarine and coastal marine environments. Climate change poses a particular threat to the structure and function of biotic co... Anthropogenic climate and non-climate drivers of change are causing significant impacts on estuarine and coastal marine environments. Climate change poses a particular threat to the structure and function of biotic communities in these environments because it acts on the most extensive temporal and spatial scales relative to other anthropogenic drivers of change. The interaction of multiple environmental drivers exacerbates degradation of ecosystem condition. Estuaries are most susceptible to climate-change mediated biotic shifts and direct anthropogenic impacts due to burgeoning human population growth and development in coastal watersheds. Multiple anthropogenic drivers of change, which often interact synergistically, alter physical, chemical, and biological characteristics. Ecological responses may be increasingly nonlinear, with cumulative effects manifested by marked changes in organism abundance, distribution, diversity, and productivity. Detrimental biotic effects in impacted coastal environments cascade up from individual organisms to population and community levels, culminating in ecosystem-level changes including reduced services. Multiple drivers of change and their impacts are increasing in estuarine and coastal marine environments with greater anthropogenic forcing in the coastal zone and global effects of climate change, creating greater challenges for environmental management and conservation programs. 展开更多
关键词 Multiple drivers Climate Change Anthropogenic Impacts Estuaries Coastal Marine Environments Management CONSERVATION RESILIENCE
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High-Level Circulating Total Calcium and Low Phosphate as Predictors of Insulin Resistance among Non-Diabetic Taxi-Motorbike Drivers Living and Working in Cotonou, Benin 被引量:2
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作者 Patrice Hodonou Avogbe Ambaliou Sanni 《Open Journal of Endocrine and Metabolic Diseases》 2022年第6期123-134,共12页
Insulin resistance (IR) is a well-recognized marker of increased cardiovascular diseases (CVDs) and type 2 diabetes (T2D) risk. Therefore, screening for IR predictors would help reduce the likelihood of progression fr... Insulin resistance (IR) is a well-recognized marker of increased cardiovascular diseases (CVDs) and type 2 diabetes (T2D) risk. Therefore, screening for IR predictors would help reduce the likelihood of progression from early stage of IR to T2D or CVDs. However, the knowledge of association between IR and circulating total calcium (CTCa) and phosphate levels among non-diabetic patients in Benin is lacking. We investigated whether CTCa and phosphate levels within the normal ranges are associated with IR risk among taxi-motorbike drivers (TMDs) living and working in Cotonou. We evaluated 134 non-diabetic TMDs (aged 22 - 59 years) based on CTCa, phosphate, glucose, fasting insulin, and IR levels. IR was assessed using the homeostatic model assessment-insulin resistance (HOMA-IR). IR was defined as the 75<sup>th</sup> percentile of HOMA-IR value. Cardiometabolic factors were analyzed by tertiles of CTCa and phosphate levels (low, middle, and high groups). Logistic regression models evaluated the relationships between IR and CTCa and phosphate levels. Our results showed that participants with high CTCa levels had the highest prevalence of IR, elevated total cholesterol and high-density lipoprotein cholesterol. In a fully adjusted model, the odd ratio (OR) of having IR comparing the highest (>2.50 mmol/L) to the lowest CTCa levels (1.23 mmol/L) and the lowest levels (<1.10 mmol/L) of phosphate was 0.28 (p = 0.037). In conclusion, our study demonstrates that elevated CTCa and low phosphate levels are significant predictors of IR in non-diabetic patients. Continuous monitoring of these markers may help identify earlier individuals at greatest IR risk. 展开更多
关键词 Blood Glucose Insulin Resistance Circulating Total Calcium Phosphate Taxi-Motorbike drivers
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