Data Mining Practical Machine Learning Tools and Techniques

Millimeter wave (mmWave) signals experience orders-of-magnitude more pathloss than the microwave signals currently used in most wireless applications and all cellular systems. MmWave systems must therefore leverage large antenna arrays, made possible by the decrease in wavelength, to combat pathloss with beamforming gain. Beamforming with multiple data streams, known as precoding, can be used to further improve mmWave spectral efficiency. Both beamforming and precoding are done digitally at baseband in traditional multi-antenna systems. The high cost and power consumption of mixed-signal devices in mmWave systems, however, make analog processing in the RF domain more attractive. This hardware limitation restricts the feasible set of precoders and combiners that can be applied by practical mmWave transceivers. In this paper, we consider transmit precoding and receiver combining in mmWave systems with large antenna arrays. We exploit the spatial structure of mmWave channels to formulate the precoding/combining problem as a sparse reconstruction problem. Using the principle of basis pursuit, we develop algorithms that accurately approximate optimal unconstrained precoders and combiners such that they can be implemented in low-cost RF hardware. We present numerical results on the performance of the proposed algorithms and show that they allow mmWave systems to approach their unconstrained performance limits, even when transceiver hardware constraints are considered.

Spatially Sparse Precoding in Millimeter Wave MIMO Systems

It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

In-band full-duplex (IBFD) operation has emerged as an attractive solution for increasing the throughput of wireless communication systems and networks. With IBFD, a wireless terminal is allowed to transmit and receive simultaneously in the same frequency band. This tutorial paper reviews the main concepts of IBFD wireless. One of the biggest practical impediments to IBFD operation is the presence of self-interference, i.e., the interference that the modem's transmitter causes to its own receiver. This tutorial surveys a wide range of IBFD self-interference mitigation techniques. Also discussed are numerous other research challenges and opportunities in the design and analysis of IBFD wireless systems.

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In-Band Full-Duplex Wireless: Challenges and Opportunities

In-band full-duplex (IBFD) operation has emerged as an attractive solution for increasing the throughput of wireless communication systems and networks. With IBFD, a wireless terminal is allowed to transmit and receive simultaneously in the same frequency band. This tutorial paper reviews the main concepts of IBFD wireless. Because one the biggest practical impediments to IBFD operation is the presence of self-interference, i.e., the interference caused by an IBFD node's own transmissions to its desired receptions, this tutorial surveys a wide range of IBFD self-interference mitigation techniques. Also discussed are numerous other research challenges and opportunities in the design and analysis of IBFD wireless systems.

The infertile individual analysis based on whole-exome sequencing in chinese multi-ethnic groups

•o-Diiodoarenes/NaH as an efficient system for aryne generation in a controlled manner •Neighboring-group-assisted metal-halogen exchange process •Sodium hydride as an iodophile reagent •Aryne insertion into C–C σ-bond of unactivated ketones Here, we document the reinvention of aryne chemistry with “old” o-diiodoarenes as aryne progenitors. We have established a NaH-mediated activation strategy for the generation of highly reactive aryne species in a controlled manner. The resulting arynes can efficiently participate in a C–C σ-bond-insertion reaction with unactivated ketones, which is difficult to achieve by existing methods. Density functional theory (DFT) calculations reveal that the two adjacent iodines in o-diiodoarenes play critical roles in the formation of aryne. The nucleophilic attack of hydride to the electrophilic iodine requires that the adjacent iodine act as a directing group to accelerate this process, whereas mono-substituted iodobenzene lacking the neighboring-group participation makes it difficult. The in-situ-formed enolates from ketones are proposed to adopt tetrameric aggregates to react with arynes, which accounts for the high regiochemistry for substrates with bulky substituents. Here, we document the reinvention of aryne chemistry with “old” o-diiodoarenes as aryne progenitors. We have established a NaH-mediated activation strategy for the generation of highly reactive aryne species in a controlled manner. The resulting arynes can efficiently participate in a C–C σ-bond-insertion reaction with unactivated ketones, which is difficult to achieve by existing methods. Density functional theory (DFT) calculations reveal that the two adjacent iodines in o-diiodoarenes play critical roles in the formation of aryne. The nucleophilic attack of hydride to the electrophilic iodine requires that the adjacent iodine act as a directing group to accelerate this process, whereas mono-substituted iodobenzene lacking the neighboring-group participation makes it difficult. The in-situ-formed enolates from ketones are proposed to adopt tetrameric aggregates to react with arynes, which accounts for the high regiochemistry for substrates with bulky substituents. 

Direct insertion into the C–C bond of unactivated ketones with NaH-mediated aryne chemistry

A well-known bottleneck of contemporary mobile devices is the inefficient and error-prone touchscreen keyboard We have developed UbiK, an alternative portable text-entry method that allows user to type on a piece of paper, placed on solid surfaces like wood desktop UbiK leverages the microphones on a mobile device to accurately localize the keystrokes through fine-grained acoustic fingerprinting We have implemented UbiK as an Android application Our experiments demonstrate that UbiK is able to achieve above 95% of localization accuracy In this demonstration, we will show how Ubik works with an external paper keyboard (Figure 1) for a smartphone and a 7-inch tablet User participation will be welcome in this live demo

Demo: A paper keyboard for mobile devices

The embodiment of the invention provides a hybrid learning method and device for improving interactive video transmission quality and electronic equipment, and the method comprises the steps: obtaining a transmission parameter of a previous transmission time slot and an inter-packet delay sequence for a current transmission time slot; inputting the transmission parameter of the previous transmission time slot into a code rate prediction deep reinforcement learning model, and determining a first alternative transmission code rate; determining a network state identification value based on an inter-packet delay trend represented by the inter-packet delay sequence; determining a network state threshold of the current transmission time slot; if the network state identification value is not greater than the network state threshold of the current transmission time slot, sending the data packet based on the first alternative transmission code rate; and if the network state identification valueis greater than the network state threshold corresponding to the current transmission time slot, determining a second alternative transmission code rate based on a transmission code rate adjustment rule, the transmission code rate of the previous transmission time slot and the transmission parameter, and sending the data packet based on the second alternative transmission code rate. By the embodiment of the invention, the quality of the video call can be improved.

Xinyu Zhang

Papers

The infertile individual analysis based on whole-exome sequencing in chinese multi-ethnic groups

Direct insertion into the C–C bond of unactivated ketones with NaH-mediated aryne chemistry

Demo: A paper keyboard for mobile devices

Hybrid learning method and device for improving interactive video transmission quality and equipment