ACTIVE: Towards Highly Transferable 3D Physical Camouflage for Universal and Robust Vehicle Evasion

Adversarial camouflage has garnered attention for its ability to attack object detectors from any viewpoint by covering the entire object's surface. However, universality and robustness in existing methods often fall short as the transferability aspect is often overlooked, thus restricting their application only to a specific target with limited performance. To address these challenges, we present Adversarial Camouflage for Transferable and Intensive Vehicle Evasion (ACTIVE), a state-of-the-art physical camouflage attack framework designed to generate universal and robust adversarial camouflage capable of concealing any 3D vehicle from detectors. Our framework incorporates innovative techniques to enhance universality and robustness, including a refined texture rendering that enables common texture application to different vehicles without being constrained to a specific texture map, a novel stealth loss that renders the vehicle undetectable, and a smooth and camouflage loss to enhance the naturalness of the adversarial camouflage. Our extensive experiments on 15 different models show that ACTIVE consistently outperforms existing works on various public detectors, including the latest YOLOv7. Notably, our universality evaluations reveal promising transferability to other vehicle classes, tasks (segmentation models), and the real world, not just other vehicles.Comment: Accepted for ICCV 2023. Main Paper with Supplementary Material. Project Page: https://islab-ai.github.io/active-iccv2023

Ch.4 Multifaceted intraseasonal Modes in the East Asain-Western North Pacific Summer Monsoon Climate

TRU

Role of the surface boundary conditions in boreal spring on the interannual variability of the multistage evolution of the East Asian summer monsoon

© 2020 American Meteorological Society.The seasonal movement of the upper-level jet plays a key role in the evolution of the East Asian summer monsoon (EASM). However, it remains unresolved how interannual changes in surface boundary conditions can influence the upper-level flow over East Asia, thereby modulating the onset of the EASM. Here we capture the timing of multistage evolution over East Asia using the upper-level zonal wind in a two-phase linear regression model. In addition, we show the impact of two surface boundary conditions on the timing of the EASM onset related to the strength of the upper-level zonal wind: 1) eastern Eurasian snow cover and 2) western North Pacific (WNP) sea surface temperature (SST) tendency. The eddy heat fluxes induced by the enhanced eastern Eurasian snow cover develop an anomalous anticyclonic circulation to the northwest, which causes anomalous warm southwesterly flow toward the north. These can make a reversal of the meridional temperature gradient, which results in the early monsoon onset via changes in the upper-level jet. The upper-level jet also responds to the SST tendency in April over the WNP via thermal wind balance and the resultant changes in transient eddy-induced heat transport. Our findings suggest potential sources for seasonal predictability in the interannual EASM onset dates11sciescopu

Disentangling Impacts of Dynamic and Thermodynamic Components on Late Summer Rainfall Anomalies in East Asia

This study has examined relative contributions of dynamic and thermodynamic components to East Asian summer monsoon (EASM), compared to the others over Asia. We have decomposed of moisture budget into the dynamic and thermodynamic components composing of interannual variability of the EASM. As represented by the moisture budget, the Asian monsoon is mostly caused by changes in winds (dynamic component); interestingly, changes in moisture (thermodynamic component) play an important role in monsoon rainfall anomalies only for East Asia (27.09%). In terms of the dynamic component over East Asia, strong continental heating, resulting in enhanced land‐sea contrast, is identified as crucial to a local development of winds toward East Asia, and it ultimately strengthens a meridional wind, which is accompanied by the western North Pacific subtropical high. In addition, the negative winter North Atlantic Oscillation could induce the enhanced moisture advection term of the dynamic component over East Asia through barotropic Rossby wave propagation. The thermodynamic component has a localized effect on net precipitation at midlatitudes, with an enhanced wave train pattern with a zonal wavenumber‐5, which reinforces the Okhotsk high. These distinct large‐scale circulation patterns together create favorable conditions for heavy rainfall over East Asia when the two components are positively in‐phase. Here we have also described that the extreme heavy rainfall is noticeable when the Eurasian blocking occurs. This study is expected to improve the detailed predictability of the EASM by understanding the two components to prevent disaster risks in terms of extreme rainfall

Impact of the Indo-Pacific Warm Pool on the Hadley, Walker, and Monsoon Circulations

The Indo-Pacific warm pool (IPWP) is enclosed by a 28 degrees C isotherm and plays a vital role in controlling atmospheric circulations. However, the effects of changes in regional warm pool sea surface temperatures (SSTs) remain unexplored. We divided the IPWP into the Indian and Pacific sectors and distinguished their responses to natural variability and global warming. Furthermore, we examined the impacts of the interannual variability (IAV) in warm pool SST on the tropical Hadley, Walker, and monsoon circulations. The Hadley circulation was affected by warm pool SST warming, i.e., warmer SSTs over the warm pool strengthened the upward branch of Hadley circulation, whereas the downward branch was respectively weakened and strengthened in the Northern and Southern Hemispheres. Walker circulation was strengthened (weakened) in the warming (natural) mode. Consequently, the Walker circulation is weakened since the natural variability of warm pool SST plays a more dominant role rather than the warming trend of SSTs over the warm pool. Furthermore, our analysis displays that warm pool warming has little impact on the monsoon circulation. Our findings highlight the different roles of the IAV of warm pool regions in each tropical circulation as part of the warming trend and natural variability.11Nsciescopu

The record-breaking 2022 long-lasting marine heatwaves in the East China Sea

In 2022, record-breaking long-lasting marine heatwaves (MHWs) occurred in the East China Sea (ECS), which persisted for 62 d during boreal summer. This exceeded the average MHWs duration of 10 d by a factor of 6. In addition, 2022 was also recorded as a year of many extreme events throughout Asia, such as summer floods in China and Pakistan, droughts and extreme heat in Europe, raising the question of whether they were caused by a ‘triple-dip’ La Niña, which has persisted since September 2020. Here we examine the key local and remote processes that led to the 2022 MHWs in the ECS using mixed-layer heat budget analysis. During the onset of the MHWs, a salinity-stratified shallow mixed-layer due to the large river discharge from the Yangtze–Huaihe River floods in June created favorable conditions for warm ocean temperature in the ECS. Simultaneously, an anomalous anticyclone maintained by the stationary Rossby wave, which is generated by vorticity forcings in mid-latitudes and thermal forcing in Pakistan, settled in the corresponding region and led to the long-lasting MHWs until Typhoon Hinnamnor began to dissipate the wave in early September. This study improves our understanding of the physical mechanism of flood-related MHWs that have increased with recent climate change

Ultra-narrow-bandgap thienoisoindigo polymers: structure-property correlations in field-effect transistors

From a structural point of view, the newly conceived thienoisoindigo (TIIG) moiety can serve as an ideal building block for the synthesis of high-performance polymers. To expand the range of available TIIG-based conjugated polymers, herein we report the synthesis and characterization of two new TIIG-based donor-acceptor polymers (PTIIG-TT and PTIIG-TVT), containing either the thieno[3,2-b] thiophene (TT) or the (E)-2-(2-(thiophen-2-yl) vinyl) thiophene (TVT) moiety. In addition, we conducted a systematic investigation on the relationship between the microstructure of the polymer film and charge transport in organic field-effect transistors (OFETs) fabricated using these polymers. It was observed that the incorporation of a TVT moiety into the TIIG backbone imparts higher crystallinity and increases the molecular packing density, leading to an increased hole mobility (similar to 0.45 cm(2) V-1 s(-1)) in PTIIG-TVT, compared with PTIIG-TT. When an Al electrode is used instead of a Au electrode in the OFET devices, both polymers exhibit outstanding ambipolar characteristics. This study advances the understanding of the structural features of TIIG-based polymers, which will potentially accelerate the improvement in the mobility of TIIG-based polymers.clos

Ambipolar organic phototransistors based on 6,6'-dibromoindigo

Ambipolar organic phototransistors were fabricated using a natural pigment 6,6-dibromoindigo (6-BrIG) as the active channel. These phototransistors yielded significantly enhanced currents upon light illumination with photoresponsivities and external quantum efficiencies as high as 10.3 A W-1 and 2437% for the n-channel, and 55.4 mA W-1 and 13.1% for the p-channel, respectively. In addition, simple inverter complementary circuits were fabricated by integrating two ambipolar phototransistors. Channel current was dependent on light intensity and voltage bias. This study provides a basis for an in-depth understanding of the optoelectronic characteristics of 6-BrIG, and introduces this material as an ecofriendly candidate for optoelectronic applications

Labeling Dual Presynaptic Inputs using cFork Anterograde Tracing System

Understanding brain function-related neural circuit connectivity is essential for investigating how cognitive functions are decoded in neural circuits. Trans-synaptic viral vectors are useful for identifying neural synaptic connectivity because of their ability to be transferred from transduced cells to synaptically connected cells. However, concurrent labeling of multisynaptic inputs to postsynaptic neurons is impossible with currently available trans-synaptic viral vectors. Here, we report a neural circuit tracing system that can simultaneously label postsynaptic neurons with two different markers, the expression of which is defined by presynaptic input connectivity. This system, called “cFork (see fork)”, includes delivering serotype 1-packaged AAV vectors (AAV1s) containing Cre or flippase recombinase (FlpO) into two different presynaptic brain areas, and AAV5 with a dual gene expression cassette in postsynaptic neurons. Our in vitro and in vivo tests showed that selective expression of two different fluorescence proteins, EGFP and mScarlet, in postsynaptic neurons could be achieved by AAV1-mediated anterograde trans-synaptic transfer of Cre or FlpO constructs. When this tracing system was applied to the somatosensory barrel field cortex (S1BF) or striatum innervated by multiple presynaptic inputs, postsynaptic neurons defined by presynaptic inputs were simultaneously labeled with EGFP or mScarlet. Our new anterograde tracing tool may be useful for elucidating the complex multisynaptic connectivity of postsynaptic neurons regulating diverse brain functions. Copyright © Experimental Neurobiology 2020.1

Contrasting Hysteresis Behaviors of Northern Hemisphere Land Monsoon Precipitation to CO2 Pathways

© 2022 The Authors. Earth's Future published by Wiley Periodicals LLC on behalf of American Geophysical Union.Understanding precipitation changes over the Northern Hemisphere land monsoon (NHLM) region, where nearly 60% of the world's population resides, is fundamental for hydrological projections and adaptations against climate change. There are many studies on the hydrological cycle under various climate change scenarios. However, there is still a lack of research on the hydrological responses to CO2 removal as a global warming mitigation measure from a global perspective. This study demonstrates the distinguished hysteresis responses of mean NHLM precipitation based on idealized CO2 ramp-up and ramp-down experiments using the Community Earth System Model|Community Earth System model. The Indian and North African monsoons have time asymmetry in the mean precipitation changes under the CO2 increase and decrease pathways, while the North American monsoon does not. The zonal contrasting hysteresis is attributed to longitudinally contrasting changes in the intertropical convergence zone position driven by the inter-hemispheric and land–sea thermal contrast. On the contrary, changes in extreme precipitation exhibit little temporal asymmetries over any of the NHLM domains. These results provide new insights into climate hysteresis of the hydrological cycle from regional and global perspectives.11Nsciescopu