•We develop a model of departure time and parking location choices by heterogeneous commuters.•We examine the distributional effects of imposing a congestion toll and/or a parking fee.•The expansion ...of parking capacity does not necessarily lead to a Pareto improvement when a parking fee is not imposed.•The self-financing principle holds separately for bottleneck capacity and parking capacity.
This study examines the effects of a time-varying congestion toll and a location-dependent parking fee on the behavior of heterogeneous commuters and their commuting costs. To this end, we develop a model of departure time and parking location choices by heterogeneous commuters and characterize its equilibrium. By comparing the equilibrium with and without pricing policies, we obtain the following results: (1) imposing a parking fee and expanding parking capacity may concentrate the temporal distribution of traffic demand, thereby exacerbating traffic congestion; (2) the expansion of parking capacity does not necessarily lead to a Pareto improvement when a parking fee is not imposed; (3) the social optimum is achieved by combining a parking fee with a congestion toll; and (4) the revenue obtained from pricing of roads and parking exactly equals the costs for optimal bottleneck and parking capacities, respectively; that is, the self-financing principle holds separately for bottleneck capacity and parking capacity.
•Probe data reveals traffic condition immediately after earthquake and tsunami.•It indicates a sudden transition of the vehicle speed lower than walking speed.•The estimated traffic condition reveals ...the serious gridlock in Ishinomaki.
This study analyzes how people behaved and traffic congestion expanded immediately after the Great East Japan Earthquake on March 11, 2011 using information such as probe vehicle and smartphone GPS data. One of the cities most seriously damaged during the earthquake was Ishinomaki. Understanding human evacuation behavior and observing road network conditions are key for the creation of effective evacuation support plans and operations. In many cases, however, a major natural disaster destroys most infrastructure sensors and detailed dynamic information on people’s movements cannot be recorded. Following the Great East Japan Earthquake, vehicle detectors did not work due to the severe tsunami and electric power failure. Therefore, information was only available from individuals’ probe vehicles and smartphone GPS data. These probe data, along with disaster measurements such as water immersion levels, revealed the sudden transition of vehicle speed (i.e., it eventually slowed to less than walking speed and a serious gridlock phenomenon in the Ishinomaki central area occurred). These quantitative findings, which could not be identified without probe data, should be utilized during future disaster mitigation planning.
In order to study spin related phenomena in nano-size materials, spin-polarized electron source (PES) has been employed for the incident beam in transmission electron microscope (TEM). The PES has ...been designed and constructed with optimizing for spin-polarized TEM. The illuminating system of TEM is also designed to focus the spin-polarized electron beam emitted from a semiconductor photocathode with a negative electron affinity (NEA) surface. The beam energy is set to below 40 keV which is lower energy type as a TEM, because the spin interaction with condensed matters is very small corresponding with a Coulomb interaction. The polarized electron gun has realized in an extra high vacuum (XHV) condition and high field gradient of 4 MV/m on a surface of photocathode. Furthermore, it demonstrated that 40-keV polarized electron beam was operated with a sub-milli second pulse mode by using the backside excitation type photocathode. This high performance PES will make it possible to observe dynamically a magnetic field images with high contrast and highspeed temporal imaging in TEM.
We examined the elemental and Sr isotopic composition of otoliths from Biwa salmon Oncorhynchus masou subsp., an endemic subspecies of the O. masou complex in the Lake Biwa (Japan) water system, to ...evaluate the usefulness of otolith chemistry as a natural tag for studying homing and migration history. Fish and water samples were collected from 5 major spawning rivers and 2 hatcheries. The elemental content relative to calcium (Na/Ca, Mg/Ca, K/Ca, Mn/Ca, Sr/Ca, and Ba/Ca) and Sr isotopic ratio ( super(87)Sr/ super(86)Sr) of the samples were analyzed using laser ablation inductively coupled plasma mass spectrometry and thermal ionization mass spectrometry, respectively. Significant variations in otolith and water sample chemistry were detected. We also observed significant relationships between the Sr/Ca, Ba/Ca, and super(87)Sr/ super(86)Sr ratios of otoliths and those of ambient water samples from which the fish were collected. The other elemental ratios and all elemental concentrations in the otoliths showed variations independent of water chemistry. Jackknife cross-validation using quadratic discriminant function analysis showed that otolith elemental composition could classify Biwa salmon juveniles by sampling location, with a high level of accuracy (mean 79%). The mean accuracy increased to 89% when Sr isotopic ratios were combined with elemental data. This study thus demonstrated the suitability of otolith chemistry for determining fish distribution. Otolith chemistry successfully revealed the natal (hatching) locations of individual fish, facilitating further understanding of migration history and habitat use, which are essential for establishing effective fishery management strategies for this Near Threatened subspecies.
This study analyzes measurements by backward moving observers that could be probe vehicles running backward on the opposite lane observing forward moving traffic to be investigated. These probe ...vehicles are called as backward probe vehicles (BP) and they are proven to measure the traffic flow and density. Using some advanced technology, a BP is assumed to estimate the flow of vehicles running forward from their passing time measurements along the BP trajectory. Then, as a useful application for the flow measurement by a BP, we propose a data assimilation method that estimates traffic states under an incident on an expressway section utilizing BP measurements in addition to conventional probe vehicles moving forward (forward probe vehicles) and detector data. Ample literature exists on traffic state estimation using several sensing data. However, they have difficulty in estimating traffic states during an incident, since the observations of the incident period and the declined flow rate due to the incident may not be sufficiently accurate. Therefore, this study proposes a state space model (SSM) that estimates traffic states under an incident on an expressway utilizing BP measurements. The model validation using a hypothetical network with an incident confirms the promising potential of the proposed model; that is, the reproducibility of traffic states using BP measurements is superior to one using forward probe measurements.
We have measured the temperature dependence of thermal conductivity up to several hundred degrees for memory device materials. In the measurement of thermal conductivity, we used a novel technique of ...nanosecond thermoreflectance measurement spectroscopy (Nano-TheMS) developed by Baba et al. The main advantage of this technique is that it can measure thin films of nanometer-order by easy sample preparation. Using this system with a heat stage, the measurement of thermal conductivities of Ge
2Sb
2Te
5 and ZnS–SiO
2, which were selected as representative materials of memory devices, from room temperature to 400 or 500
°C was carried out. All thermal conductivities increased with higher temperature. Using their temperature dependence, optical disk thermal simulation was carried out, and the results were compared with conventional calculated results without the dependence. It was found that the largest difference at maximum temperature was approximately 80
°C. The temperature dependence of thermal properties is essential for realistic temperature simulation.
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•The network-wide traffic state spatial interpolation by a mixture GGM.•The mixture GGM reasonably estimated the unobserved road link speeds.•It is useful for traffic state ...interpolation and understanding traffic state change.
This study proposes a model that estimates unobserved highway link speeds by a machine learning technique using historical probe vehicle data. For highway traffic monitoring, probe vehicle data is one of the most promising data source. However, since such data do not always cover an entire study area, we cannot measure traffic speeds on all links in a time-dependent manner; quite a few links are unobserved. To continuously monitor speeds on all links, it is necessary to develop a technique that estimates speeds on unobserved links from historical observed link speeds. For this purpose, we extend the current Gaussian graphical model so as to use two or more multivariate normal distributions to accurately estimate unobserved link speeds. In general, since the number of unknown model parameters (mean parameters and covariance matrices) is enormous and also unobserved links always exist, the EM algorithm and the graphical lasso technique are employed to determine the model parameters. Our proposed model was applied to the Bangkok city center in Thailand as well as to the Fujisawa city in Japan. We confirmed that the model can estimate the unobserved link speeds quite reasonably.
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