A Simple Model of Optimal Hate Crime Legislation

We present a simple model of the effects of hate crime legislation. It shows that even if the direct harm to victims of hate crime is the same as for other crimes, because of other differences in the effects it may still be optimal to exert more law-enforcement effort to deter or prevent hate crime. These differences also have previously unrecognized effects on the optimal level of effort by potential hate crime victims to avoid being victimized, thus affecting the efficiency of government policies that encourage or discourage such effort. We discuss the implications of these results for optimal hate-crime policy, as well as for policy toward other similar crimes, such as terrorism.

Vector Fields with the Oriented Shadowing Property

We give a description of the \Cone-interior (\Int^1(\OrientSh)) of the set of smooth vector fields on a smooth closed manifold that have the oriented shadowing property. A special class \Bb of vector fields that are not structurally stable is introduced. It is shown that the set \Int^1(\OrientSh\setminus\Bb) coincides with the set of structurally stable vector fields. An example of a field of the class \Bb belonging to \Int^1(\OrientSh) is given. Bibliography: 18 titles.Comment: 42 page

A reexamination of the effective fine structure constant of graphene, as measured in graphite

We present a refined and improved study of the influence of screening on the effective fine structure constant of graphene, $\alpha^*$, as measured in graphite using inelastic x-ray scattering. This follow-up to our previous study [J. P. Reed, et al., Science 330, 805 (2010)] was carried out with two times better energy resolution, five times better momentum resolution, and improved experimental setup with lower background. We compare our results to RPA calculations and evaluate the relative importance of interlayer hopping, excitonic corrections, and screening from high energy excitations involving the $\sigma$ bands. We find that the static, limiting value of $\alpha^*$ falls in the range 0.25 to 0.35, which is higher than our previous result of 0.14, but still below the value expected from RPA. We show the reduced value is not a consequence of interlayer hopping effects, which were ignored in our previous analysis, but of a combination of excitonic effects in the $\pi \rightarrow \pi^*$ particle-hole continuum, and background screening from the $\sigma$-bonded electrons. We find that $\sigma$-band screening is extremely strong at distances of the order of a few nm, and should be highly effective at screening out short-distance, Hubbard-like interactions in graphene, as well as other carbon allotropes.Comment: 23 pages, 5 figure

Combined transarterial chemoembolization and arterial administration of Bletilla striata in treatment of liver tumor in rats

AIM: To evaluate and compare the effect of combined transarterial chemoembolization (TACE) and arterial administration of Bletilla striata (a Chinese traditional medicine against liver tumor) versus TACE alone for the treatment of hepatocellular carcinoma (HCC) in ACI rats. METHODS: Subcapsular implantation of a solid Morris hepatoma 3 924A (2 mm3) in the liver was carried out in 30 male ACI rats. Tumor volume (V1) was measured by magnetic resonance imaging (MRI) on day 13 after implantation. The following different agents of interventional treatment were injected after retrograde catheterization via gastroduodenal artery (on day 14), namely, (A) TACE (0.1 mg mitomycin + 0.1 ml Lipiodol) + Bletilla striata (1.0 mg) (n=10); (B) TACE + Bletilla striata (1.0 mg) + ligation of hepatic artery (n=10), (C) TACE alone (control group, n=10). Tumor volume (V2) was assessed by MRI (on day 13 after treatment) and the tumor growth ratio (V2/V1) was calculated. RESULTS: The mean tumor volume before (V1) and after (V2) treatment was 0.0355 cm3 and 0.2248 cm3 in group A, 0.0374 cm3 and 0.0573 cm3 in group B, 0.0380 cm3 and 0.3674 cm3 in group C, respectively. The mean ratio (V2/V1) was 6.2791 in group A, 1.5324 in group B and 9.1382 in group C. Compared with the control group (group C), group B showed significant inhibition of tumor growth (P0.05). None of the animals died during implantation or in the postoperative period. CONCLUSION: Combination of TACE and arterial administration of Bletilla striata plus ligation of hepatic artery is more effective than TACE alone in the treatment of HCC in rats

Factors in Debris Accumulation at Bridge Piers

Debris accumulation at bridge piers has been a significant problem at a number of bridge sites in Indiana, increasing risks of upstream flooding, scour, and stream instability. The current study aimed at identifying factors contributing to debris accumulation in order to formulate guidelines for the design of new bridges that would minimize their occurrence or impact. Three related approaches were taken: i) a systematic study of the available underwater bridge inspections reports, ii) a program of periodic visits and visual examination of bridge sites that were thought to be prone to debris accumulation, and iii) continued video monitoring of three bridge sites, and analysis of video images recorded during debris-transporting events. The available underwater bridge inspection reports spanned a period of 10 years and covered 370 structures. Heavy debris accumulation was observed at ¡Ö20% of these sites, with the heaviest accumulations being concentrated in southwestern Indiana. Almost all of the sites in south-central and southern Indiana experienced at least moderate debris accumulation at one time. Sites with estimated volume of debris accumulation greater than 1000 cubic yards (¡®mega¡¯ sites), sites where heavy debris accumulation was observed during more than one inspection (¡®chronic¡¯ sites), and sites with at most minor debris accumulation during more than one inspection (¡®lite¡¯ sites) were examined in greater detail with regards to their crosssectional geometry and the placement of the piers, and the specific location of debris accumulation. A program of periodic site inspections was undertaken that eventually covered 22 sites, including 4 ¡®mega¡¯ sites and 6 ¡®chronic¡¯ sites. The sites were visited at intervals of 3 ¨C 4 months over a 16-month period, and visually examined with regards to the occurrence and location of any debris accumulation, and other features, such as the presence of upstream bridges, that might be related to debris accumulation. These observations were combined with cross-section information from underwater bridge inspection reports to corroborate or refine the conclusions drawn from the broader study of underwater bridge inspection reports. Issues that could not be resolved from the bridge inspection reports, such as the behavior over time of debris accumulation, and the relationship to hydrologic events, were of particular interest in the periodic-site inspections. Although some sites suffered what might be classed as ¡®heavy¡¯ accumulation during the study period, no ¡®mega¡¯ accumulation occurred at any site, suggesting that average recurrence intervals for such events are more than 16 months, at least for larger rivers. Finally, video monitoring of debris-transporting events was conducted at three sites including one ¡®mega¡¯ site. This yielded the most detailed information regarding aspects that were visible above the water surface. This included including the variation of debris ¡®discharge¡¯ and amount of debris accumulated with time, typical debris trajectories, and even direct evidence of disaggregation of already accumulated debris. At two of the sites, extensive debris accumulations, possibly approaching ¡®mega¡¯ class at one site, were recorded. In contrast, little debris accumulation was noted at the third site in spite of quite heavy debris transport during at least one large flow event. For larger, longer-duration flow events, debris transport seemed to be concentrated towards the earlier rising part, such as the first 12 ¨C 18 hours, of the event. Little correlation between the lateral location within the stream where debris transport is high and the thalweg in the immediate vicinity of the bridge crossing was found. On the basis of the observations made during the study, recommended practices are suggested for designing bridges with the aim of minimizing debris accumulation

Learning Vision-and-Language Navigation from YouTube Videos

Vision-and-language navigation (VLN) requires an embodied agent to navigate in realistic 3D environments using natural language instructions. Existing VLN methods suffer from training on small-scale environments or unreasonable path-instruction datasets, limiting the generalization to unseen environments. There are massive house tour videos on YouTube, providing abundant real navigation experiences and layout information. However, these videos have not been explored for VLN before. In this paper, we propose to learn an agent from these videos by creating a large-scale dataset which comprises reasonable path-instruction pairs from house tour videos and pre-training the agent on it. To achieve this, we have to tackle the challenges of automatically constructing path-instruction pairs and exploiting real layout knowledge from raw and unlabeled videos. To address these, we first leverage an entropy-based method to construct the nodes of a path trajectory. Then, we propose an action-aware generator for generating instructions from unlabeled trajectories. Last, we devise a trajectory judgment pretext task to encourage the agent to mine the layout knowledge. Experimental results show that our method achieves state-of-the-art performance on two popular benchmarks (R2R and REVERIE). Code is available at https://github.com/JeremyLinky/YouTube-VLNComment: Accepted by ICCV 202

Webots-based Simulator for Biped Navigation in Human-living Environments

Navigation is one of the key issues of biped robot, especially in complicated and uncertain human-living environment. There have been challenges for ensuring the stability, efficiency and security of the biped navigation system. In this paper, a framework utilizing sampling-based footstep planner is proposed for the simulation of the biped navigation. Sensor fusion method is adopted to process and generate the correlated environment information for footstep planning. Two specific experiments have been conducted to validate the functionality and performance of the proposed framework