A formulation of the relaxation phenomenon for lane changing dynamics in an arbitrary car following model

Lane changing dynamics are an important part of traffic microsimulation and are vital for modeling weaving sections and merge bottlenecks. However, there is often much more emphasis placed on car following and gap acceptance models, whereas lane changing dynamics such as tactical, cooperation, and relaxation models receive comparatively little attention. This paper develops a general relaxation model which can be applied to an arbitrary parametric or nonparametric microsimulation model. The relaxation model modifies car following dynamics after a lane change, when vehicles can be far from equilibrium. Relaxation prevents car following models from reacting too strongly to the changes in space headway caused by lane changing, leading to more accurate and realistic simulated trajectories. We also show that relaxation is necessary for correctly simulating traffic breakdown with realistic values of capacity drop

Magnetoresistance of atomic-scale electromigrated nickel nanocontacts

We report measurements of the electron transport through atomic-scale constrictions and tunnel junctions between ferromagnetic electrodes. Structures are fabricated using a combination of e-beam lithography and controlled electromigration. Sample geometries are chosen to allow independent control of electrode bulk magnetizations. As junction size is decreased to the single channel limit, conventional anisotropic magnetoresistance (AMR) increases in magnitude, approaching the size expected for tunneling magnetoresistance (TMR) upon tunnel junction formation. Significant mesoscopic variations are seen in the magnitude and sign of the magnetoresistance, and no evidence is found of large ballistic magnetoresistance effects.Comment: 3 pages, 3 figure

Searching for onset of deconfinement via hypernuclei and baryon-strangeness correlations

We argue that the ratio $S_3 =\mathrm{^3_\Lambda H} / (\mathrm{^3He} \times \frac{\Lambda}{p})$ is a good representation of the local correlation between baryon number and strangeness, and therefore is a valuable tool to probe the nature of the dense matter created in high energy heavy-ion collision: quark gluon plasma or hadron gas. A multiphase transport model (AMPT) plus a dynamical coalescence model is used to elucidate our arguments. We find that AMPT with string melting predicts an increase of $S_3$ with increasing beam energy, and is consistent with experimental data, while AMPT with only hadronic scattering results in a low $S_3$ throughout the energy range from AGS to RHIC, and fails to describe the experimental data.Comment: add several sentences in paragraph 2 and 3, one more paragraph (4) and one more reference (11) to address the referee's queries. accepted versio

Variance Reduction for Score Functions Using Optimal Baselines

Many problems involve the use of models which learn probability distributions or incorporate randomness in some way. In such problems, because computing the true expected gradient may be intractable, a gradient estimator is used to update the model parameters. When the model parameters directly affect a probability distribution, the gradient estimator will involve score function terms. This paper studies baselines, a variance reduction technique for score functions. Motivated primarily by reinforcement learning, we derive for the first time an expression for the optimal state-dependent baseline, the baseline which results in a gradient estimator with minimum variance. Although we show that there exist examples where the optimal baseline may be arbitrarily better than a value function baseline, we find that the value function baseline usually performs similarly to an optimal baseline in terms of variance reduction. Moreover, the value function can also be used for bootstrapping estimators of the return, leading to additional variance reduction. Our results give new insight and justification for why value function baselines and the generalized advantage estimator (GAE) work well in practice

Where Are We Going? Parent-child television reality programmes in China

This article looks at the role of format television in the People’s Republic of China. It juxtaposes two key ideas: the ‘one format policy’ and the One Child Policy. Both are government restrictions intended to kerb reproduction. Formats provide a means for the reproduction of programming ideas, that is, they are generative. When formats ‘fit’ cultural understandings they can be remarkably successful, as with family oriented formats. Yet there is something unusual about China: in comparison to many international markets, China offers a unique demographic – those people born after 1978. The article examines a formatted programme called Where Are We Going, Dad? introduced into China from South Korea, which illustrates a subgenre known as the ‘parent-child caring’ (qinzi) format. The article shows how this genre has capitalised on the interest in the health and future well-being of the One Child in China, as well as spinning off its own formatted offspring

The utility of wide-field optical coherence tomography angiography in diagnosis and monitoring of proliferative diabetic retinopathy in pregnancy

Purpose: Diabetic retinopathy is an increasingly common complication of diabetes mellitus that benefits from early diagnosis and frequent monitoring, especially in pregnancy where there is a greater risk of progression. Fundus fluorescein angiography is currently the gold standard method of investigation for neovascularization. However, this has risks of unpleasant and potentially dangerous side effects, with an added theoretical risk to the fetus in pregnancy. Wide-field optical coherence tomography angiography (PLEX Elite 9000, Carl Zeiss Meditec, Inc. USA and DRI Swept Source OCT Triton, Topcon Medical Systems, Inc. USA) potentially offers a safer, faster and equally effective alternative method for diagnosis and monitoring of diabetic retinopathy in pregnant patients. Observations: In the 3 cases reviewed from our clinic, we found that wide-field optical coherence tomography angiography was successfully used as an alternative to fundus fluorescein angiography in early diagnosis and ongoing monitoring of diabetic retinopathy in pregnant patients. Conclusions and importance: Wide-field optical coherence tomography angiography can be considered as a useful alternative to fundus fluorescein angiography when reviewing pregnant diabetic retinopathy patients. This allows avoidance of any unpleasant and potentially dangerous side effects associated with fluorescein injection, and appears to be just as effective in diagnosis and detecting disease progression

Theoretical background of supply chain management and potential supply chain of North Queensland timber industry

This paper examines the suitability of supply chain management (SCM) as a methodology for examining forestry development options in north Queensland - both industrial and farm - with particular emphasis on hoop pine. SCM has been defined from different perspectives by various authors and some of the alternative definitions of SCM are given. SCM is then placed in the context of the north Queensland timber industry focusing on the current structure and participants and the factors that need to be considered to make the supply chain for hoop pine more efficient. This highlights the need for a broader and more extensive supply chain for the north Queensland timber industry. Facilitation of a broader supply chain requires the development of mechanisms to improve cooperation between supply chain participants. This includes the expansion of the hoop pine resource area, value-adding processes, and improved information flows. The goal of research in progress is to develop a framework to facilitate a diverse multilayered supply chain for hoop pine that will promote a north Queensland industry that is economically and environmentally viable