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- 摘要
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[IEEE 2019 Photonics North (PN) - Quebec City, QC, Canada (2019.5.21-2019.5.23)] 2019 Photonics North (PN) - In-band pumped composite Nd:YVO/Nd:GVO laser
摘要： In binary classi?cation, two-way confusion matrices, with corresponding measures, such as sensitivity and speci?city, have become so ubiquitous that those who review results may not realize there are other and more realistic ways to visualize data. This is, particularly, true when risk and reward considerations are important. The approach suggested here proposes that classi?cation need not offer a conclusion on every instance within a data set. If an algorithm ?nds instances (e.g., patient cases in a medical data set) in which attributes pertaining to a patient’s disease offer zero to nil information, there should be no classi?cation offered. From the physician’s perspective, disclosure of nil information should be welcome because it might prevent potentially harmful treatment. It follows from this that the developer of a classi?er can provide summary results amendable for helping the consumer decide whether or not it is prudent to pass or act (commission versus omission). It is not always about balancing sensitivity and speci?city in all cases, but optimizing action on some cases. The explanation is centered on John Kelly’s link of gambling with Shannon information theory. In addition, Graham’s margin of safety, Bernoulli’s utiles, and Hippocratic Oath are important. An example problem is provided using a Netherlands Cancer Institute breast cancer data set. Recurrence score, a popular molecular-based assay for breast cancer prognosis, was found to have an uninformative zone. The uninformative subset had been grouped with positive results to garner higher sensitivity. Yet, because of a positive result, patients might be advised to undergo potentially harmful treatment in the absence of useful information.
关键词： data compression,cancer,clinical diagnosis,sensitivity and speci?city,Data analysis,genetic expression,entropy
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Experimental Demonstration of Entropic Steering
摘要： Quantum entanglement is a key resource for foundational quantum information and communication tasks, such as teleportation, entanglement swapping and quantum key distribution [1]. Quantum steering is a quantum correlation that is distinct from other nonclassical correlations such as Bell nonlocality [2] and entanglement. Steering describes the effect of measuring one system, let’s say Alice, and affecting the measurement results on the other system, let’s say Bob. Moving through the hierarchy of nonlocal classes, from Bell nonlocality towards nonseparability, requires an increasing number of parties and apparatus that need to be trusted but gives access to protocols which are more robust to noise for projective measurements [3,4]. In a quantum steering task [5] the correlations of Alice and Bob’s measurement outcomes are tested against a classical probability bound which can be only violated if the state shared between the parties is quantum steerable. Establishing such steering criteria via semidefinite programming [6-8] requires assumptions about Alice’s measurements and is restricted to small dimensions. Entropic uncertainty relations [9,10] were recently identified as a fundamental tool to develop steering criteria. It has been shown that using the so-called Tsallis entropy allows for generalising recent entropic steering criteria [11,12] which were restricted to the case of Shannon entropy. Here, we experimentally test the recently derived inequality by Costa et al. [13] for m = 2 measurement directions for Alice and Bob. For that, we consider a shared polarisation encoded Werner state which is defined as ρ = μ|Ψs??Ψs| + (1?μ) I4, where μ ∈ [0; 1], I4 is the 4 × 4 identity matrix and |Ψs? = (|01? ? |10?)/√2 between our observers Alice and Bob [14]. We used data from Wollmann et al. [15] to test if S (q) = C ? ∑k [Sq(Bk|Ak) + (1 ? q)C(Ak, Bk)] violates S (q) ≤ 0 [13]. Violation of this inequality demonstrates steering of Bob’s state. We successfully show quantum steering and found our inequality (Fig.1 (red curve))to be more robust to measurement deviations than comparable inequalities (Fig.1 (blue curve)).
关键词： Tsallis entropy,Quantum steering,Shannon entropy,Quantum entanglement
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Spiral Bandwidth of Four-Wave Mixing in Rubidium Vapour
摘要： Atomic vapours are an experimentally simple and ef?cient system in which to study nonlinear wave mixing. We study a four-wave mixing (FWM) process in rubidium vapour which ef?ciently converts 780 and 776 nm light to 420 nm and 5.2 μm ?elds [1]. In particular, we quantitatively investigate the transfer of orbital angular momentum (OAM) between the FWM ?elds. OAM, and structured light more generally, is an important research tool for optical manipulation, imaging and communication. Phase-matched nonlinear processes are both longitudinally and transversely phase coherent, and therefore OAM, which is associated with spiral phase fronts, must be conserved between the pump and generated ?elds [2]. This makes wave mixing an ideal tool for frequency conversion and generation of a variety of OAM states for use in both classical and quantum communication [3]. In our FWM process, conservation of OAM determines the total OAM carried by the 420 nm and 5.2 μm ?elds - but not how it is distributed between them. Fig. 1 (a) shows the intensity pro?le and interferogram (formed by interfering the beam with its mirror image) of the 420 nm ?eld when the pump beams each carry (cid:2)ˉh of OAM ((cid:2) = (cid:2)780 = (cid:2)776). We perform quantitative analysis of each interferogram to obtain the full Laguerre-Gauss mode decomposition of the 420 nm ?eld (Fig. 1 (b)). For small values of pump OAM, the 420 nm light is generated predominantly in one mode [4], but as the pump OAM increases the OAM spectrum broadens [5]. In order for OAM to be conserved, this indicates that the 420 nm and 5.2 μm light is generated in an OAM-entangled state. From the 420 nm mode decomposition we infer the spiral bandwidth (a measure of the number of entangled modes), Δ(cid:2)B, as well as the entanglement entropy, S, of this state. Both the experimental and theoretical results show that the generated state is strongly pump mode-dependent, with the spiral bandwidth increasing with increasing pump OAM. These results indicate that this system is likely to be an ef?cient source of OAM-entangled photon pairs with widely-disparate wavelengths.
关键词： entanglement entropy,orbital angular momentum,four-wave mixing,rubidium vapour,spiral bandwidth
更新于2025-09-16 10:30:52
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Fatigue behaviour of a laser beam welded CoCrFeNiMn-type high entropy alloy
摘要： Laser beam welding was used to produce butt joints from the CoCrFeNiMn-type high entropy alloy. The alloy in the initial condition had an fcc single-phase coarse-grained structure. Laser welding resulted in the M7C3-type carbides precipitation in the fcc matrix. The carbide particles precipitation resulted in a considerable increase in microhardness from 150 HV 0.5 for the as-sintered condition to 205 HV 0.5 in the fusion zone. Laser beam welding had a negligible effect on both static mechanical properties and fatigue behaviour of the alloy. The endurance limit of either type of specimens (i.e. with and without welding seam) was 200 MPa. Fracture of all specimens with the laser beam welded seams occurred in the base material area during both tensile and fatigue testing. Weak effect of welding on static/fatigue behaviour of the alloy can be attributed to the higher hardness of the fusion zone, resulting in strain localization in the base material area. An increase in load resulted in activation of secondary slip systems and formation of deformation twins in fatigue specimens.
关键词： Fatigue,Tensile strength,Microstructure,Laser beam welding,High entropy alloy
更新于2025-09-16 10:30:52
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Spin-orbit-coupled quantum memory of a double quantum dot
摘要： The concept of quantum memory plays an incisive role in the quantum information theory. As confirmed by the several recent rigorous mathematical studies, the quantum memory inmate in the bipartite system ρAB can reduce the uncertainty about part B, after measurements done on part A. In the present work, we extend this concept to systems with a spin-orbit coupling and introduce the notion of spin-orbit quantum memory. We self-consistently explore the Uhlmann fidelity, the pre- and the post-measurement entanglement entropy, and the post-measurement conditional quantum entropy of the system with spin-orbit coupling and show that measurement performed on the spin subsystem decreases the uncertainty of the orbital part. The uncovered effect enhances with the strength of the spin-orbit coupling. We study the concept of macroscopic realism introduced by Leggett and Garg [Phys. Rev. Lett. 54, 857 (1985)] and observe that POVM measurements done on the system under the particular protocol are noninvasive. For the extended system, we perform quantum Monte Carlo calculations and consider the reshuffling of the electron densities due to an external electric field.
关键词： quantum Monte Carlo,spin-orbit coupling,entanglement entropy,POVM measurements,conditional quantum entropy,quantum memory,Uhlmann fidelity
更新于2025-09-12 10:27:22
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Drivers and Anticipated Outcomes of Solar Photovoltaic Projects –The Construction Practitioners’ Perspectives
摘要： Despite Australia receives high levels of solar radiation annually, contributions to energy production from solar sources are significantly low across the country. Whist there is no lack of studies reviewing the initiatives of solar photovoltaic (PV) projects in Australia; few have been conducted in an approach that target construction industry’s view and their professionals’ perspectives on the solar PV projects. With the growing consensus that climate change is a threat facing today’s society, this study aims to identify the relevant drivers and outcomes of solar PV projects for today’s construction industry professionals and subsequently prioritise these phenomenon in terms of their importance and anticipation. Therefore, this study approached construction industry professionals to solicit their views regarding drivers and outcomes of solar PV implementation through an online questionnaire survey. The data received from the survey was subsequently analysed through an entropy ranking approach, facilitating prioritisation and ranking of both the drivers and outcomes. The findings reveal that construction professionals prioritise lowering the cost of solar PV technology as the most effective driver to result in their increased PV uptake, and resultantly anticipate greater solar PV efficiency and energy storage as the most important outcome. The findings of this study are insightful as they deconstruct barriers that may prevent construction professionals from implementing solar PV projects. Future study in this field is suggested to focus on ways in which lowered costs of solar PV technology can be achieved and technology efficiency levels increased.
关键词： construction industry,solar photovoltaic projects,entropy ranking,outcomes,drivers
更新于2025-09-12 10:27:22
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Laser Beam Welding of a Low Density Refractory High Entropy Alloy
摘要： The effect of laser beam welding on the structure and properties of a Ti1.89NbCrV0.56 refractory high entropy alloy was studied. In particular, the effect of different pre-heating temperatures was examined. Due to the low ductility of the material, laser beam welding at room temperature resulted in the formations of hot cracks. Sound butt joints without cracks were produced using pre-heating to T ≥ 600 °C. In the initial as-cast condition, the alloy consisted of coarse bcc grains with a small amount of lens-shaped C15 Laves phase particles. A columnar microstructure was formed in the welds; the thickness of the grains increased with the temperature of pre-heating before welding. The Laves phase particles were formed in the seams after welding at 600 °C or 800 °C, however, these particles were not observed after welding at room temperature or at 400 °C. Soaking at elevated temperatures did not change the microstructure of the base material considerably, however, “additional” small Laves particles formed at 600 °C. Tensile test of welded specimens performed at 750 °C resulted in the fracture of the base material because of the higher hardness of the welds. The latter can be associated with the bcc grains refinement in the seams.
关键词： microstructure,mechanical properties,laser beam welding,high entropy alloys
更新于2025-09-12 10:27:22
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Entanglement via entangled-boundary-condition trajectories: Long-time accuracy
摘要： Entanglement is considered as a purely quantum effect. The present paper, however, joins many other works that pursue the idea of describing it using classical quantities. In particular, we are interested in the entanglement dynamics of a pure state composed of two parts, initially prepared in a product of coherent states and governed by a generic Hamiltonian. In this scenario, the linear entropy of the reduced state, our entanglement quanti?er, was shown to be written, in the short-time regime, in terms of a real trajectory of the underlying classical dynamics. We extend this semiclassical result by demonstrating that it is possible to include complex trajectories in the calculation. This strategy contributes to improving the previous approximation, extending its accuracy for longer values of time. We also show, for a particular Hamiltonian, a ?rst application of the achieved formula, attesting to its ef?ciency.
关键词： semiclassical approximation,entanglement,quantum dynamics,linear entropy,complex trajectories
更新于2025-09-11 14:15:04
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High‐entropy transparent fluoride laser ceramics
摘要： For the first time, a transparent high‐entropy fluoride laser ceramic has been prepared and characterized. X‐ray diffraction (XRD) analysis of a CeNdCaSrBaF12 (CNCSBF) transparent ceramic consolidated by vacuum hot pressing (VHP) reveals that Ce3+, Nd3+, Ca2+, Sr2+, and Ba2+ have formed a single‐phased fluorite solid solution, with a lattice constant of 5.826??. Bulk density measurements produced a value of 6.15?g/cm3. Scanning electron microscopy (SEM) analysis of the ceramic revealed a uniform distribution of grain sizes in the material, with the average grain size being approximately 20?μm. The material exhibits a maximum in‐line transmittance of approximately 60% at 1000?nm. A near‐infrared range photoluminescence (PL) emission band was observed at 1057?nm, with a visible‐range PL emission band being located at 440?nm.
关键词： high entropy,transparent ceramics,optical properties,fluoride
更新于2025-09-11 14:15:04
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[IEEE 2019 41st Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC) - Berlin, Germany (2019.7.23-2019.7.27)] 2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - An Improved Liquid Metal Mask Printing enabled Fast Fabrication of Wearable Electronics on Fabrics <sup>*</sup>
摘要： The rare earth con?guration entropy dependence of the crystal structure, microstructure and magnetic properties for SmCo5 based intermetallic compounds has been systematically investigated by using power X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy and magnetic measurement. The studies show that the single phase with CaCu5 type structure forms in (Sm1/2Nd1/2)Co5, (Sm1/3Nd1/3Y1/3)Co5 and (Sm1/4Nd1/4Y1/4Tb1/4)Co5. The formation of single phase is derived from Miedema's model due to the mixing enthalpy of 0 kJ$mol(cid:1)1 at rare earth site. The high entropy (Sm1/4Nd1/4Y1/4Tb1/4)Co5 intermetallic compound is obtained due to its con?guration entropy of 1.39R and rare earth equiatomic ratio at Sm site. The morphologic images show that the grains are growing and agglomerating with doping equiatomic rare earth Y and Tb. The magnetization of sample cannot reach saturation within the maximum ?eld of 30 kOe at room temperature, the magnetizing curve follows the Langevin model for SmCo5 and (Sm1/2Nd1/2)Co5, and the modi?ed Langevin model for (Sm1/3Nd1/3Y1/3)Co5 and (Sm1/4Nd1/4Y1/4Tb1/4)Co5, respectively. The ?tted magnetization is going down with substitution of nonmagnetic Y and heavy rare earth Tb due to the diluting magnetic effect of nonmagnetic Y substitution for Sm and the weakened effects on moment of Tb moment arrangement antiparallel to that of Co. The coercivity tends to decrease due to the agglomeration and growth of grains. It implies that the con?guration entropy seems to have little effect on the room temperature magnetizing process.
关键词： High entropy,Single phase,SmCo5 intermetallic compound,Magnetic property
更新于2025-09-11 14:15:04