Verbal Explanations for Deep Reinforcement Learning Neural Networks with Attention on Extracted Features

In recent years, there has been increasing interest in transparency in Deep Neural Networks. Most of the works on transparency have been done for image classification. In this paper, we report on work of transparency in Deep Reinforcement Learning Networks (DRLNs). Such networks have been extremely successful in learning action control in Atari games. In this paper, we focus on generating verbal (natural language) descriptions and explanations of deep reinforcement learning policies. Successful generation of verbal explanations would allow better understanding by people (e.g., users, debuggers) of the inner workings of DRLNs which could ultimately increase trust in these systems. We present a generation model which consists of three parts: an encoder on feature extraction, an attention structure on selecting features from the output of the encoder, and a decoder on generating the explanation in natural language. Four variants of the attention structure full attention, global attention, adaptive attention and object attention - are designed and compared. The adaptive attention structure performs the best among all the variants, even though the object attention structure is given additional information on object locations. Additionally, our experiment results showed that the proposed encoder outperforms two baseline encoders (Resnet and VGG) on the capability of distinguishing the game state images

A dynamic-data-driven driving variability modeling and simulation for emergency evacuation

ABSTRACT This paper presents a dynamic data driven approach of describing driving variability in microscopic traffic simulations for both normal and emergency situations. A four-layer DGIT (Decision, Games, Individual and Transform) framework provides the capability of describing the driving variability among different scenarios, vehicles, time and models. A four-step CCAR (Capture, Calibration, Analysis and Refactor) procedure captures the driving behaviors from mass real-time data to calibrate and analyze the driving variability. Combining the DGIT framework and the CCAR procedure, the system can carry out adaptive simulation in both normal and emergency situations, so that be able to provide more accurate prediction of traffic scenarios and help for decision-making support. A preliminary experiment is performed on a major urban road, and the results verified the feasibility and capability of providing prediction and decision-making support

Cytosolic and Nucleosolic Calcium Signaling in Response to Osmotic and Salt Stresses Are Independent of Each Other in Roots of Arabidopsis Seedlings

Calcium acts as a universal second messenger in both developmental processes and responses to environmental stresses. Previous research has shown that a number of stimuli can induce [Ca2+] increases in both the cytoplasm and nucleus in plants. However, the relationship between cytosolic and nucleosolic calcium signaling remains obscure. Here, we generated transgenic plants containing a fusion protein, comprising rat parvalbumin (PV) with either a nuclear export sequence (PV-NES) or a nuclear localization sequence (NLS-PV), to selectively buffer the cytosolic or nucleosolic calcium. Firstly, we found that the osmotic stress-induced cytosolic [Ca2+] increase (OICIcyt) and the salt stress-induced cytosolic [Ca2+] increase (SICIcyt) were impaired in the PV-NES lines compared with the Arabidopsis wildtype (WT). Similarly, the osmotic stress-induced nucleosolic [Ca2+] increase (OICInuc) and salt stress-induced nucleosolic [Ca2+] increase (SICInuc) were also disrupted in the NLS-PV lines. These results indicate that PV can effectively buffer the increase of [Ca2+] in response to various stimuli in Arabidopsis. However, the OICIcyt and SICIcyt in the NLS-PV plants were similar to those in the WT, and the OICInuc and SICInuc in the PV-NES plants were also same as those in the WT, suggesting that the cytosolic and nucleosolic calcium dynamics are mutually independent. Furthermore, we found that osmotic stress- and salt stress-inhibited root growth was reduced dramatically in the PV-NES and NLS-PV lines, while the osmotic stress-induced increase of the lateral root primordia was higher in the PV-NES plants than either the WT or NLS-PV plants. In addition, several stress-responsive genes, namely CML37, DREB2A, MYB2, RD29A, and RD29B, displayed diverse expression patterns in response to osmotic and salt stress in the PV-NES and NLS-PV lines when compared with the WT. Together, these results imply that the cytosolic and nucleosolic calcium signaling coexist to play the pivotal roles in the growth and development of plants and their responses to environment stresses

In situ atomic scale mechanisms of strain-induced twin boundary shear to high angle grain boundary in nanocrystalline Pt

Twin boundary can both strengthen and soften nanocrystalline metals and has been an important path for improving the strength and ductility of nano materials. Here, using in-lab developed double-tilt tensile stage in the transmission electron microscope, the atomic scale twin boundary shearing process was in situ observed in a twin-structured nanocrystalline Pt. It was revealed that the twin boundary shear was resulted from partial dislocation emissions on the intersected {111} planes, which accommodate as large as 47% shear strain. It is uncovered that the partial dislocations nucleated and glided on the two intersecting {111} slip planes lead to a transition of the original symmetric tilt ∑3/(111) coherent twin boundary into a symmetric tilt ∑9/(114) high angle grain boundary. These results provide insight of twin boundary strengthening mechanisms for accommodating plasticity strains in nanocrystalline metals

Study of Curing Kinetics and Properties of Epoxy/Amine Curing Reactions

環氧樹脂性質優良,但其本身的脆性使應用略受限制,本文主要使用脂 肪族胺硬化劑,另外還使用兩種不同凝膠含量的高分子多元胺硬化劑,探討 其硬化反應動力學,與不同的凝膠含量對於物性的影響. 本研究採用的 三種動力學方程式,在任何一個硬化劑的系統,都不能完全敘述環氧樹脂硬 化反應的動力學,總是在某轉化率以上即與實 驗值偏離,但大體而言, 包含n級反應速率常數和自催化反應速率常數的方程式dx/dt=(K1+K2 x^m)(1-x)^n,比較能正確反應環氧樹脂硬化的情形;在高分子型胺硬化劑 中,凝膠含量較高者,總反應級數較高,反應較慢;而在DMA的測試及SEM的觀 察上,顯示凝膠含量高的硬化劑,交連程度高,耗能模數高,低溫斷裂後呈一 圈圈的片狀裂紋,表示存在高分子的接枝共聚合物,能分散外力,使破壞能 量增加.Epoxy resins has excellent properties,but its brittleness makes someapplication restricted.This study uses ether diamine and polymeric aminecuring agents containing different gel content to cure epoxy resin, the kinetics and physical properties are studied. This study uses three kinetic models to describe the curing behavior of different curing agent.No any of kinetic models can completely correspond to curing reactions accurately,especially when the conversion exceeds 60%.The model with equation dx/dt=(K1+K2x^m)(1-x)^n,includes the n order reaction rate constant and autocatalytic reaction rate constant ,can describe the curing behavior of epoxy resins better than other models .The polymeric amine curing agents with more gel content show a higher loss modulus.The low temperature fractal surface exhibits a local circle-like crack pattern for polymer amine curing agents.This shows the addition of polymer amine curing agents can disperse impact energy and increase the toughness