Optical Coherence Tomography guided Laser-Cochleostomy

Despite the high precision of laser, it remains challenging to control the laser-bone ablation without injuring the underlying critical structures. Providing an axial resolution on micrometre scale, OCT is a promising candidate for imaging microstructures beneath the bone surface and monitoring the ablation process. In this work, a bridge connecting these two technologies is established. A closed-loop control of laser-bone ablation under the monitoring with OCT has been successfully realised

Attribute Simulation for Item Embedding Enhancement in Multi-interest Recommendation

Although multi-interest recommenders have achieved significant progress in the matching stage, our research reveals that existing models tend to exhibit an under-clustered item embedding space, which leads to a low discernibility between items and hampers item retrieval. This highlights the necessity for item embedding enhancement. However, item attributes, which serve as effective and straightforward side information for enhancement, are either unavailable or incomplete in many public datasets due to the labor-intensive nature of manual annotation tasks. This dilemma raises two meaningful questions: 1. Can we bypass manual annotation and directly simulate complete attribute information from the interaction data? And 2. If feasible, how to simulate attributes with high accuracy and low complexity in the matching stage? In this paper, we first establish an inspiring theoretical feasibility that the item-attribute correlation matrix can be approximated through elementary transformations on the item co-occurrence matrix. Then based on formula derivation, we propose a simple yet effective module, SimEmb (Item Embedding Enhancement via Simulated Attribute), in the multi-interest recommendation of the matching stage to implement our findings. By simulating attributes with the co-occurrence matrix, SimEmb discards the item ID-based embedding and employs the attribute-weighted summation for item embedding enhancement. Comprehensive experiments on four benchmark datasets demonstrate that our approach notably enhances the clustering of item embedding and significantly outperforms SOTA models with an average improvement of 25.59% on [email protected]: This paper has been accepted by the 17th ACM International Conference on Web Search and Data Mining (WSDM 2024). The camera-ready version will be available in the conference proceeding

TNC-UTM: A Holistic Solution to Secure Enterprise Networks

This paper presents TNC-UTM, a holistic solution to secure enterprise networks from gateway to endpoints. Just as its name suggested, the TNC-UTM solution combines two popular techniques TNC and UTM together by defining an interface between them that integrates their security capacity to provide efficiently network access control and security protection for enterprise network. Not only TNC-UTM provides the features of TNC and UTM, but also it achieves stronger security and higher performance by introducing intelligent configuration decisions and RBAC mechanism. Experiment demonstrated the superior advantages of the TNC-UTM solution

Verification of the standard theory of plasma emission with particle-in-cell simulations

The standard theory of plasma emission is based on kinetic couplings between a single beam of energetic electrons and unmagnetized thermal plasmas, involving multi-step nonlinear wave-particle and wave-wave interactions. The theory has not yet been completely verified with fully-kinetic electromagnetic particle-in-cell (PIC) simulations. Earlier studies, greatly limited by available computational resources, are controversial regarding whether the fundamental emission can be generated according to the standard theory. To resolve the controversy, we conducted PIC simulations with a large domain of simulation and a large number of macroparticles, among the largest ones of similar studies. We found significant fundamental emission if the relative beam density is small enough (say, $\le$ 0.01), in line with earlier study with a much-smaller domain; the relative intensity (normalized by the total initial beam energy) of all modes, except the mode associated with the beam-electromagnetic Weibel instability, decreases with increasing relative density of the beam. We also found significant transverse magnetic component associated with the superluminal Langmuir turbulence, which has been mistakenly regarded as evidence of the F emission in earlier study. Further investigations are required to reveal their origin

Research on surface movement and deformation characteristics of loess gully landform in Northern Shaanxi

In order to study the surface movement and deformation characteristics of the collapsible loess gully landform in the northern Shaanxi mining area in the middle reaches of the Yellow River Basin, the N1212 working face in the loess gully area of the Ningtiaota Mine has been systematically monitored for surface subsidence to analyze the high-intensity mining conditions Deformation characteristics of the ground surface subsidence, determine the maximum surface subsidence speed and the maximum subsidence speed lag angle, surface movement time and dynamic surface movement parameters. The results of the study show that the discontinuous deformation and destruction of the surface in high-strength coal mining in the collapsible loess layer in northern Shaanxi are severe, and the loess surface is easily affected by the combined effects of movement and deformation and topographic conditions, resulting in uneven settlement. Under high-strength mining conditions, the surface movement and deformation are severely developed , The maximum surface subsidence value is 5255 mm, the maximum horizontal movement value is 2680 mm, the maximum subsidence speed is 187.4 mm/d, the maximum subsidence coefficient of single coal seam mining is 0.63, the maximum subsidence coefficient of oblique repeated mining is 0.84, the active period is about 55 d, and the period of subsidence is about 55 d. The amount accounts for 97% of the total subsidence, the maximum lagging distance of the down-town velocity is 74 m, and the maximum lagging angle of the sinking velocity is 67°. The above results verify that in the high-intensity mining of shallow coal seams, the surface subsidence is proportional to the geological mining factors when the ground subsidence is severe, the activity period is short, and the mining is repeated. The surface deformation of high-intensity mining in the valley terrain has the characteristics of fast speed, large collapse and heavy damage

Optical coherence tomography guided laser cochleostomy: towards the accuracy on tens of micrometer scale

Lasers have been proven to be precise tools for bone ablation. Applying no mechanical stress to the patient, they are potentially very suitable for microsurgery on fragile structures such as the inner ear. However, it remains challenging to control the laser-bone ablation without injuring embedded soft tissue. In this work, we demonstrate a closed-loop control of a short-pulsed CO2 laser to perform laser cochleostomy under the monitoring of an optical coherence tomography (OCT) system. A foresighted detection of the bone-endosteum-perilymph boundary several hundred micrometers before its exposure has been realized. Position and duration of the laser pulses are planned based on the residual bone thickness distribution. OCT itself is also used as a highly accurate tracking system for motion compensation between the target area and the optics. During ex vivo experimental evaluation on fresh porcine cochleae, the ablation process terminated automatically when the thickness of the residual tissue layer uniformly reached a predefined value. The shape of the resulting channel bottom converged to the natural curvature of the endosteal layer without injuring the critical structure. Preliminary measurements in OCT scans indicated that the mean absolute accuracy of the shape approximation was only around 20 μm

Optical Coherence Tomography Guided Laser Cochleostomy: Towards the Accuracy on Tens of Micrometer Scale

Lasers have been proven to be precise tools for bone ablation. Applying no mechanical stress to the patient, they are potentially very suitable for microsurgery on fragile structures such as the inner ear. However, it remains challenging to control the laser-bone ablation without injuring embedded soft tissue. In this work, we demonstrate a closed-loop control of a short-pulsed CO2 laser to perform laser cochleostomy under the monitoring of an optical coherence tomography (OCT) system. A foresighted detection of the bone-endosteum-perilymph boundary several hundred micrometers before its exposure has been realized. Position and duration of the laser pulses are planned based on the residual bone thickness distribution. OCT itself is also used as a highly accurate tracking system for motion compensation between the target area and the optics. During ex vivo experimental evaluation on fresh porcine cochleae, the ablation process terminated automatically when the thickness of the residual tissue layer uniformly reached a predefined value. The shape of the resulting channel bottom converged to the natural curvature of the endosteal layer without injuring the critical structure. Preliminary measurements in OCT scans indicated that the mean absolute accuracy of the shape approximation was only around 20 mu m

Optical Coherence Tomography guided Laser-Cochleostomy

Despite the high precision of laser, it remains challenging to control the laser-bone ablation without injuring the underlying critical structures. Providing an axial resolution on micrometre scale, OCT is a promising candidate for imaging microstructures beneath the bone surface and monitoring the ablation process. In this work, a bridge connecting these two technologies is established. A closed-loop control of laser-bone ablation under the monitoring with OCT has been successfully realised

A SEQUENCY DIVISION MULTIPLEX SYSTEM

International Telemetering Conference Proceedings / October 13-15, 1981 / Bahia Hotel, San Diego, CaliforniaA sequency division multiplex (SDM) system using Walsh subcarriers was developed for the transmission of telemetry signals at our laboratory The basis of mathematics which can form a telemetry system is orthogonal function. It is the Walsh function that may form a new telemetry system. At the first stage a baseband transmission system has been designed and tested. It shows that the results of experiments are quite good, and the new system works well. At a second stage FM is used as carrier transmission. Now the whole system can work property. A proper choice of the subcarriers minimizes the crosstalk. Principles for the selection of Walsh subcarriers are deduced. It seems that the SDM system has great potentialies.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection