Semantic Proximity Alignment: Towards Human Perception-consistent Audio Tagging by Aligning with Label Text Description

Most audio tagging models are trained with one-hot labels as supervised information. However, one-hot labels treat all sound events equally, ignoring the semantic hierarchy and proximity relationships between sound events. In contrast, the event descriptions contains richer information, describing the distance between different sound events with semantic proximity. In this paper, we explore the impact of training audio tagging models with auxiliary text descriptions of sound events. By aligning the audio features with the text features of corresponding labels, we inject the hierarchy and proximity information of sound events into audio encoders, improving the performance while making the prediction more consistent with human perception. We refer to this approach as Semantic Proximity Alignment (SPA). We use Ontology-aware mean Average Precision (OmAP) as the main evaluation metric for the models. OmAP reweights the false positives based on Audioset ontology distance and is more consistent with human perception compared to mAP. Experimental results show that the audio tagging models trained with SPA achieve higher OmAP compared to models trained with one-hot labels solely (+1.8 OmAP). Human evaluations also demonstrate that the predictions of SPA models are more consistent with human perception.Comment: 5 pages, 3 figures. Submitted to ICASSP 202

Spin Squeezing through Collective Spin-Spin Interactions

Spin squeezing provides crucial quantum resource for quantum metrology and quantum information science. Here we propose that one axis-twisted (OAT) spin squeezing can be generated from free evolution under a general coupled-spin model with collective spin-spin interactions. We further propose pulse schemes to recover squeezing from parameter imperfections, and reach the extreme squeezing with Heisenberg-limited measurement precision scaling as $1/N$ for $N$ particles. This work provides a feasible method for generating extreme spin squeezing

catena-Poly[[bis­(1H-benzimidazole-κN 3)palladium(II)]-μ-benzene-1,4-dicarboxyl­ato-κ2 O 1:O 4]

In the title compound, [Pd(C8H4O4)(C7H6N2)2]n, the Pd atom is tetra­coordinated by two carboxyl­ate O atoms from two benzene-1,4-dicarboxyl­ate (bdc) dianions and two N atoms from two benzimidazole ligands, resulting in a slightly distorted tetra­hedral PdO2N2 geometry. The bdc ligand acts as a bridge, linking the Pd atoms into a chain. Inter-chain N—H⋯O hydrogen bonds help to stabilize the crystal structure

μ-Oxido-bis­({4,4′-dibromo-2,2′-ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato}iron(III))

In the title compound, [Fe2(C16H12Br2N2O2)2O], the complete mol­ecule is generated by twofold symmetry, with the bridging O atom, which links the iron centres, lying on the roatation rotation axis. The Fe(III) ion is chelated by the N,N,O,O-tetra­dentate Schiff base dianion, resulting in an FeN2O3 square-based pyramid, with the two N atoms in the basal plane

μ-Oxido-bis­{chlorido[tris­(2-pyridylmethyl)amine]manganese(III)} bis­(hexa­fluorido­phosphate)

In the title compound, [Mn2O(C18H18ClN4)2](PF6)2, the Mn atom is chelated by a tetra­dentate ligand via four N atoms, and further bonded to one chloride ion and one bridging oxide, to give a centrosymmetric cation and distorted octa­hedral coordination geometry

Bis[N-(8-quinol­yl)pyridine-2-carbox­amidato-κ3 N,N′,N′′]manganese(III) perchlorate monohydrate

The MnIII ion in the title complex, [Mn(C15H10N3O)2]ClO4·H2O, is coordinated meridionally by six N atoms from two tridentate N-(8-quinol­yl)pyridine-2-carboxamidate ligands, yielding a distorted octa­hedral coordination geometry. The two ligands are nearly planar and their mean planes are almost perpendicular, with a dihedral angle of 86.7 (2)°

Heisenberg-limited spin squeezing in coupled spin systems

Spin squeezing plays a crucial role in quantum metrology and quantum information science. Its generation is the prerequisite for further applications but still faces an enormous challenge since the existing physical systems rarely contain the required squeezing interactions. Here we propose a universal scheme to generate spin squeezing in coupled spin models with collective spin-spin interactions, which commonly exist in various systems. Our scheme can transform the coupled spin interactions into squeezing interactions, and reach the extreme squeezing with Heisenberg-limited measurement precision scaling as $1/N$ for $N$ particles. Only constant and continuous driving fields are required, which is accessible to a series of current realistic experiments. This work greatly enriches the variety of systems that can generate the Heisenberg-limited spin squeezing, with broad applications in quantum precision measurement