1,732 research outputs found

    Landau level crossing in a spin-orbit coupled two-dimensional electron gas

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    We have studied experimentally theï¾ Landau levelï¾ (LL) spectrum of a two-dimensionalï¾ electron gasï¾ (2DEG)ï¾ in an In0.53Ga0.47As/InPï¾ quantum wellï¾ structure by means of low-temperature magneto-transport coincidence measurement in vectorï¾ magnetic fields.ï¾ It is well known that LL crossing occurs in tiltedï¾ magnetic fieldsï¾ due to a competition between cyclotron energy andï¾ Zeeman effect.ï¾ Remarkably, here we observe an additional type of level-crossing resulting from a competition between Rashba andï¾ Zeeman splittingï¾ in a smallï¾ magnetic field,ï¾ consistent with theï¾ theoreticalï¾ prediction for strongly spin-orbit coupledï¾ 2DEG

    The Integrity of Financial Analysts: Evidence from Asymmetric Responses to Earnings Surprises

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    This paper investigates the integrity of financial analysts by examining their recommendation responses to large quarterly earnings surprises. Although there is no significant difference in recommendation changes between affiliated and unaffiliated analysts in response to positive earnings surprises, affiliated analysts are more reluctant than unaffiliated analysts to downgrade stock recommendations in response to negative earnings surprises. The evidence implies that conflicts of interest undermine the integrity of financial analysts. We further examine the effects of reputation concern and the Global Research Analyst Settlement as informal and formal mechanisms, on restoring analysts’ integrity. The results show that the positive bias in recommendations remains prevalent for affiliated analysts from reputable investment banks and for the postreform period. Finally, evidence from market reactions suggests that investors fail to notice that analysts’ integrity is compromised by conflicts of interest and are misled by affiliated analysts

    Discovering New Intents with Deep Aligned Clustering

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    Discovering new intents is a crucial task in dialogue systems. Most existing methods are limited in transferring the prior knowledge from known intents to new intents. They also have difficulties in providing high-quality supervised signals to learn clustering-friendly features for grouping unlabeled intents. In this work, we propose an effective method, Deep Aligned Clustering, to discover new intents with the aid of the limited known intent data. Firstly, we leverage a few labeled known intent samples as prior knowledge to pre-train the model. Then, we perform k-means to produce cluster assignments as pseudo-labels. Moreover, we propose an alignment strategy to tackle the label inconsistency problem during clustering assignments. Finally, we learn the intent representations under the supervision of the aligned pseudo-labels. With an unknown number of new intents, we predict the number of intent categories by eliminating low-confidence intent-wise clusters. Extensive experiments on two benchmark datasets show that our method is more robust and achieves substantial improvements over the state-of-the-art methods. The codes are released at https://github.com/thuiar/DeepAligned-Clustering.Comment: Accepted by AAAI 2021 (Main Track, Long Paper

    Mechanism of crack branching in the fatigue crack growth path of 2324-T39 Aluminium alloy

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    The crack growth behavior in 2324-T39 aluminium alloy was experimentally investigated. Two types of crack branching were observed. The mechanism of an uncommon crack branching which results from the link up of secondary crack with the main crack was focused on. The crack paths were observed with optical microscope and in-situ SEM. Finite element crack tip simulation was performed to investigate the relationship between plastic zone size and the location of the secondary crack. Tests and analysis results indicate that the secondary crack initiates near the plastic zone boundary and from the subsurface. The mechanism of this kind crack branching relates to the interaction of grain size and plastic zone size

    Comparison of quality of life following unilateral or bilateral Symfony implantation

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    AIM: To compare the postoperative quality of life between patients who underwent binocular and unilateral Symfony continuous-vision intraocular lens(IOL)implantation. METHODS: A population-based cross-sectional study was performed. The visual function-related quality of life(QoL)was evaluated with the National Eye Institute Visual Functioning Questionnaire-25(NEI VFQ-25)which was developed by the National Eye Institute. Thirty patients(60 eyes)who underwent phacoemulsification combined with IOL implantation from March 2017 to March 2018 were divided into two groups according to the type of implanted IOL. For bilateral group(36 eyes in 18 cases), patients accepted TECNIS Symfony(ZXR00, AMO)in both eyes. For unilateral group(24 eyes in 12 cases), patients accepted TECNIS Symfony(ZXR00, AMO)in one eye and an aspherical monofocal IOL(PCB00,AMO)in the other eye. Follow-up was performed 3-6mo after surgery. Postoperative binocular uncorrected distant, intermediate and near visual acuity(bUCDVA, bUCIVA and bUCNVA)were compared and the quality of life was evaluated for every patient. RESULTS:There were no statistical differences in bUCDVA, bUCIVA and bUCNVA between two groups(P>0.05). There was no significant difference in composite scores of the NEI VFQ-25 questionnaire between bilateral group and unilateral group(88.95±4.01 vs 88.99±4.22, t=-0.025, P=0.980). A comparison of the 12 scales acquired from the questionnaire showed that there were no statistical differences in visual function-related quality of life in the two groups(P>0.05). CONCLUSION:Compared with bilateral implantation of ZXR00, the patients with the implantation of ZXR00 in one eye and PCB00 in the other eye share the excellent binocular uncorrected distant, intermediate and near visual acuity and postoperative quality of life. For patients who have undergone monofocal IOL implantation in one eye or whose one eye is not suitable for multifocal IOLs, unilateral implantation of Symfony continuous-vision IOL is feasible to meet patients' need for spectacle independency
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