Read, Watch, and Move: Reinforcement Learning for Temporally Grounding Natural Language Descriptions in Videos

The task of video grounding, which temporally localizes a natural language description in a video, plays an important role in understanding videos. Existing studies have adopted strategies of sliding window over the entire video or exhaustively ranking all possible clip-sentence pairs in a pre-segmented video, which inevitably suffer from exhaustively enumerated candidates. To alleviate this problem, we formulate this task as a problem of sequential decision making by learning an agent which regulates the temporal grounding boundaries progressively based on its policy. Specifically, we propose a reinforcement learning based framework improved by multi-task learning and it shows steady performance gains by considering additional supervised boundary information during training. Our proposed framework achieves state-of-the-art performance on ActivityNet'18 DenseCaption dataset and Charades-STA dataset while observing only 10 or less clips per video.Comment: AAAI 201

Wstępne badania dotyczące zróżnicowania ekspresji receptorów kortykotropiny w gruczolakach nadnerczy

Introduction: The ACTH receptor (ACTHR) is primarily expressed in the adrenal cortex. Previous studies focused on the regulatory function of ACTHR in glucocorticoid secretion, but research on adrenal tumours is rare. The aim of this study was to evaluate ACTHR expression in common adrenal adenomas and investigate its influence on adrenal tumorigenesis using adrenocortical H295R cells. Materials and methods: Real-time polymerase chain reaction and western blot were used to detect the expression of ACTHR in 18 aldosterone-producing adenomas, 16 cortisol-producing adenomas, 9 non-functional adenomas, and 12 normal adrenal samples. Lentiviral vector pLVX-mCMV-ACTHR-ZsGreen was transfected into the H295R cells to increase ACTHR expression. WST-1 and cell count were applied to evaluate cell proliferation at different ACTHR levels. TUNEL staining was used to measure cell apoptosis. Results: Compared with normal adrenal samples, the aldosterone-producing adenoma samples had higher ACTHR mRNA and protein levels. However, the mRNA and protein levels of ACTHR in non-functional adenomas and cortisol-producing adenomas were lower than those in the normal adrenal samples. Proliferative activity in the experimental cells was higher than that in the control cells in the first three days. The proliferative activity peaked in the second day. However, this trend was reversed in the fourth day and became more apparent with time. By contrast, TUNEL staining showed that ACTHR overexpression did not induce a significant difference between the two groups. Conclusions: Differential ACTHR expression may be determined by different types of adrenocortical tumours. ACTHR is more likely to have induced the proliferation rather than the apoptosis of H295R cells.Wstęp: Receptor kortykotropiny (adrenocorticotropic hormone receptor, ACTHR) występuje głównie w korze nadnerczy. Prowadzono wcześniej badania dotyczące regulacyjnej funkcji ACTHR w wydzielaniu glikokortykoidów, lecz rzadko obejmowały one chorych z guzami nadnerczy. Badanie przeprowadzono w celu oceny ekspresji ACTHR w najczęstszych gruczolakach nadnerczy i zbadania jej wpływu na rozwój tych nowotworów w komórkach kory nadnerczy ludzkich linii H295R. Materiał i metody: Do wykrycia ekspresji ACTHR w 18 gruczolakach wydzielających aldosteron, 16 gruczolakach wydzielających kortyzol, 9 gruczolakach nieczynnych hormonalnie i 12 próbkach prawidłowych nadnerczy użyto reakcji łańcuchowej polimerazy w czasie rzeczywistym oraz metody Western blot. W celu zwiększenia ekspresji ACTHR transfekowano wektor lentiwirusowy pLVX-mCMV-ACTHR-ZsGreen do komórek H295R. Proliferację komórek przy różnych poziomach ekspresji ACTHR oceniono na podstawie WST-1 oraz liczby komórek. W celu zmierzenia apoptozy komórek zastosowano barwienie metodą TUNEL. Wyniki: W porównaniu z próbkami prawidłowych nadnerczy w próbkach gruczolaków wydzielających aldosteron stwierdzono wyższą ekspresję mRNA i białka ACTHR. Jednak ekspresja mRNA i białka ACTHR w gruczolakach nieczynnych hormonalnie oraz w gruczolakach wydzielających kortyzol była niższa niż w próbkach prawidłowych nadnerczy. W ciągu 3 pierwszych dni aktywność proliferacyjna w komórkach eksperymentalnych była wyższa niż w komórkach kontrolnych. Aktywność proliferacyjna osiągnęła maksymalną wartość w drugim dniu. Jednak w czwartym dniu ta tendencja uległa odwróceniu, co było wyraźniejsze w miarę upływu czasu. Z kolei barwienie metodą TUNEL wykazało, że nad ekspresja ACTHR nie spowodowała istotnej różnicy między grupami. Wnioski: Zróżnicowanie ekspresji ACTHR może wynikać z różnych typów guzów nadnerczy ocenianych w badaniu. Wydaje się, że ACTHR pobudza proliferację, a nie apoptozę komórek H295R

Strongly Enhanced Current-Carrying Performance in MgB2 Tape Conductors by Novel C60 Doping

MgB2 is a promising superconductor for important large-scale applications for both high field magnets and cryocooler-cooled magnet operated at temperatures around 20 K. In this work, by utilizing C60 as a viable alternative dopant, we demonstrate a simple and industrially scaleable rout that yields a 10-15-fold improvement in the in-high-field current densities of MgB2 tape conductors. For example, a Jc value higher than 4x10^4 A/cm^2 (4.2 K, 10 T), which exceeds that for NbTi superconductor, can be realized on the C60 doped MgB2 tapes. It is worth noting that this value is even higher than that fabricated using strict high energy ball milling technique under Ar atmosphere. At 20 K, Hirr was about 10 T for C60 doped MgB2 tapes. A large amount of nanometer-sized precipitates and grain boundaries were found in MgB2 matrix. The special physical and chemical characteristic of C60, in addition to its C containing intrinsic essence, is a key point in enhancing the superconducting performance of MgB2 tapes.Comment: 18 pages, 5 figure

Airworthiness Compliance Verification Method Based on Simulation of Complex System

AbstractA study is conducted on a new airworthiness compliance verification method based on pilot-aircraft-environment complex system simulation. Verification scenarios are established by “block diagram” method based on airworthiness criteria. A pilot-aircraft-environment complex model is set up and a virtual flight testing method based on connection of MATLAB/Simulink and Flightgear is proposed. Special researches are conducted on the modeling of pilot manipulation stochastic parameters and manipulation in critical situation. Unfavorable flight factors of certain scenario are analyzed, and reliability modeling of important system is researched. A distribution function of small probability event and the theory on risk probability measurement are studied. Nonlinear function is used to depict the relationship between the cumulative probability and the extremum of the critical parameter. A synthetic evaluation model is set up, modified genetic algorithm (MGA) is applied to ascertaining the distribution parameter in the model, and a more reasonable result is obtained. A clause about vehicle control functions (VCFs) verification in MIL-HDBK-516B is selected as an example to validate the practicability of the method