计量经济分析 = Econometric analysis

行銷硏究 : Marketing research

The Lancet Commission on pollution and health

Highway Capacity Manual改訂の動向--テイラ-教授の講演より

In the study, skeletal status was evaluated in 2850 females aged 7 to 77 yr using quantitative ultrasound (QUS amplitude-dependent speed of sound [Ad-SoS]). Ad-SoS ranged from 1923 ± 30 to 1876 ± 81 m/s, and the peak value (2121 m/s) was achieved in 19-yr-old females. Ad-SoS increased significantly between subgroups aged 11 and 12 yr, 12 and 13 yr, 13 and 14 yr, 14 and 15 yr, and 15 and 16 yr. After the age of 19 yr the only significant drop was noted between age groups 47 and 48 yr. Ad-SoS was regressed on age, weight, and height for age ranges 7 to 11 yr. (before an increase in Ad-SoS), 12 to 19 yr (from the onset of the increase to the peak value), and older than 19 yr to menopause. In females after menopause, years since menopause (YSM) were taken into consideration. In the two youngest groups Ad-SoS was affected positively by age, and in the two next groups, age had a negative influence on Ad-SoS, whereas weight had a negative and height a positive influence in all groups. YSM did not influence the Ad-SoS value. It was concluded that QUS measurements at the hand phalanges are a useful tool in assessment of skeletal status in the female population.

/pdf/a-cross-sectional-study-5bxl913lpz.pdf

A Cross-Sectional Study

China leads the world in both public bikeshare and private electric bike (e-bike) growth. Current trajectories indicate the viability of deploying large-scale shared e-bike (e-bikeshare) systems in China. We employ a stated preference survey and multinomial logit to model the factors influencing the choice to switch from an existing transportation mode to bikeshare or e-bikeshare in Beijing. Demand is influenced by distinct sets of factors: the bikeshare choice is most sensitive to measures of effort and comfort while the e-bikeshare choice is more sensitive to user heterogeneities. Bikeshare demand is strongly negatively impacted by trip distance, temperature, precipitation, and poor air quality. User demographics however do not factor strongly on the bikeshare choice, indicating the mode will draw users from across the social spectrum. The e-bikeshare choice is much more tolerant of trip distance, high temperatures and poor air quality, though precipitation is also a highly negative factor. User demographics do play a significant role in e-bikeshare demand. Analysis of impact to the existing transportation system finds that both bikeshare and e-bikeshare will tend to draw users away from the "unsheltered modes", walk, bike, and e-bike. Although it is unclear if shared bikes are an attractive "first-and-last-mile solution", it is clear that e-bikeshare is attractive as a bus replacement. Language: en

Factors influencing the choice of shared bicycles and shared electric bikes in Beijing

E-bikes in the Mainstream: Reviewing a Decade of Research

https://escholarship.org/content/qt1w0101dt/qt1w0101dt.pdf?t=lnorh9

Use characteristics and mode choice behavior of electric bike users in China

Electric two-wheelers have become a significant mode of transportation in China in the past decade. Though marketed and publicized by some as zero-emission vehicles, little past research has been done to quantify the environmental impacts of electric two-wheelers in China. This paper quantifies some of the environmental impacts of the production processes and use phase of electric two-wheelers and compares them to the environmental impacts of competing modes, including bicycles, buses, motorcycles and cars. The use phase emissions are quantified geographically with significantly higher emissions in coal rich regions, compared to regions relying more on hydropower. The results show that electric two-wheelers emit several times lower pollution per kilometer than motorcycles and cars, have comparable emission rates to buses and higher emission rates than bicycles. Lead is one pollutant on which electric two-wheelers perform poorly, because of their use of lead acid batteries.

/pdf/comparative-environmental-impacts-of-electric-bikes-in-china-xl7aju5ull.pdf

Comparative environmental impacts of electric bikes in China

E-bikes in China are the single largest adoption of alternative fuel vehicles in history, with more than 100 million e-bikes purchased in the past decade and vehicle ownership about 2× larger for e-bikes as for conventional cars; e-car sales, too, are rapidly growing. We compare emissions (CO2, PM2.5, NOX, HC) and environmental health impacts (primary PM2.5) from the use of conventional vehicles (CVs) and electric vehicles (EVs) in 34 major cities in China. CO2 emissions (g km–1) vary and are an order of magnitude greater for e-cars (135–274) and CVs (150–180) than for e-bikes (14–27). PM2.5 emission factors generally are lower for CVs (gasoline or diesel) than comparable EVs. However, intake fraction is often greater for CVs than for EVs because combustion emissions are generally closer to population centers for CVs (tailpipe emissions) than for EVs (power plant emissions). For most cities, the net result is that primary PM2.5 environmental health impacts per passenger-km are greater for e-cars than for ...

Christopher R. Cherry

Papers

Factors influencing the choice of shared bicycles and shared electric bikes in Beijing

E-bikes in the Mainstream: Reviewing a Decade of Research

Use characteristics and mode choice behavior of electric bike users in China

Comparative environmental impacts of electric bikes in China

Electric vehicles in China: emissions and health impacts.