Miracle-dz/UniFAR-FTUs huggingface dataset:
A 1.8Gb/s, 2.3pJ/bit, Crystal-Less IR-UWB Transmitter for Neural Implants

Frontier research in neuroscience places a high demand for high-density, implantable, wireless Brain-Machine Interfaces (BMIs) consisting of more than 1,000 recording channels with a sampling rate up to 20 to 30kS/s per channel to acquire the precise activity of a single neuron. A wireless data link with Gb/s throughput is strongly required. In addition to the data-rate, the wireless telemetry module faces a strictly limited power budget of only a few milliwatts, to avoid tissue heating. Thirdly, a compact implant design with as few as possible off-chip components is expected to minimize the harm caused by the implant. Impulse-radio Ultra-WideBand (IR-UWB) enables Gb/s throughput with low power consumption and high integrability, due to its large available bandwidth and circuit optimization. One of the major design challenges of IR-UWB is that the transmit power density is limited to -41.3dBm/MHz to comply with the FCC spectral mask, while the energy per TX pulse needs to be high enough to ensure the transcutaneous data transmission. To alleviate this contradiction, modulation schemes with higher modulation order have been proposed [1–3]. [2] proposed Extended Multi-Pulse-Position Modulation (E-MPPM), achieving a modulation order of 3. However, the sync pulse in E-MPPM reduced the modulation order by 1/3. [3] improved the modulation order to 7 by introducing a 4PAM-8PSK-4PPM hybrid modulation, but it requires an initiative reduction of the TX pulse amplitude due to the use of PAM, resulting in a reduction of the transmission range. In addition, the 8PSK modulation used in [3] requires a high frequency 8-phase carrier with a power-hungry upconversion architecture. On the other hand, an all-digital transmitter with edge-combine technique features higher power efficiency [1], [2], [4], but the modulation order is limited to 1 to 3 due to the lack of phase modulation.
Broadband Omnidirectional Circularly Polarized Antenna with High Gain

In this work, a broadband circularly polarized (CP) antenna with omnidirectional radiation and high gain is proposed for base station applications. The antenna consists of full wavelength strips, half wavelength strips and half wavelength loops in series, which ensure the in-phase currents along the antenna. The impedance bandwidth of the antenna is 3.3-3.89 GHz, whereas the axial ratio bandwidth is 3.35-3.97GHz. As a result, an overlapping bandwidth of 3.35-3.89GHz is achieved, mostly covering the band for 5G communications. The maximum antenna gain is 8.85 dBic.
Planar Inverted-F Antennas for Low Earth Orbit Satellite Applications

This paper presents a dual band planar inverted-F antenna (PIFA) for low earth orbit (LEO) satellite application. The antenna is composed of 2 inverted-F elements which operating in different frequency bands. To ensure the antenna works properly, the combination of antenna and satellite shell was fabricated and measured. Measurement results indicate that the proposed antenna works well at 2.099 GHz with a bandwidth of 116 MHz and 2.28 GHz with a bandwidth of 158 MHz while the radiation pattern shows a unidirectional property and the total efficiency is higher than 90%. In addition, the proposed antenna is compact and low profile which makes it very suitable for satellite communication system.
Rambda: RDMA-driven Acceleration Framework for Memory-intensive µs-scale Datacenter Applications

Responding to the "datacenter tax" and "killer microseconds" problems for memory-intensive datacenter applications, diverse solutions including Smart NIC-based ones have been proposed. Nonetheless, they often suffer from high overhead of communications over network and/or PCIe links. To tackle the limitations of the current solutions, this paper proposes RAMBDA, a holistic network and architecture co-design solution that leverages current RDMA and emerging cache-coherent off-chip interconnect technologies. Specifically, RAMBDA consists of four hardware and software components: (1) unified abstraction of inter- and intra-machine communications synergistically managed by one-sided RDMA write and cache-coherent memory write; (2) efficient notification of requests to accelerators assisted by cache coherence; (3) cache-coherent accelerator architecture directly interacting with NIC; and (4) adaptive device-to-host data transfer for modern server memory systems comprising both DRAM and NVM exploiting state-of-the-art features in CPUs and PCIe. We prototype RAMBDA with a commercial system and evaluate three popular datacenter applications: (1) in-memory key-value store, (2) chain replication-based distributed transaction system, and (3) deep learning recommendation model inference. The evaluation shows that RAMBDA provides 30.1~69.1% lower latency, 0.2~2.5× throughput, and ~ 3× higher energy efficiency than the current state-of-the-art solutions, including Smart NIC. For those cases where Rambda performs poorly, we also envision future architecture to improve it.
Accelerating cryo-EM Reconstruction of RELION on the New Sunway Supercomputer

Over the long journey of understanding the micro-world, cryo- EM has become an effective technique for biomolec-ular structure determinations. However, due to the complex algorithmic features and large amounts of computing data, so-phisticated HPC solutions are in urgent demand. In this paper, we present our efforts of porting RELION to the new generation of Sunway supercomputer. Optimizations that fit well with the new hardware architecture have been proposed, including a multi-level parallel scheme that smartly maps and scales RELION onto the novel Sun way architecture, optimizations that address memory bottlenecks and improve memory efficiency, and a pipeline approach that obtains excellent computation and communication overlapping. Combining all proposed optimizations, the calculation time for one iteration is greatly reduced from 7,577 seconds to 2,017 seconds, with a speedup of 3.757x. The overall design is scaled to over 131,072 cores with a parallel efficiency of 95 %.
Ah-Q: Quantifying and Handling the Interference within a Datacenter from a System Perspective

Interference among applications frequently occurs in a datacenter and significantly influences the cost-efficiency and the user experience. However, it is challenging for us to quantify the exact intensity of the interference that occurred in the overall system of a datacenter, because there are many concurrent applications in a datacenter, and their type can be either latency-critical (LC) and best-effort (BE). To address this issue, we present the Ah-Q which includes a theory and a strategy.First, we propose the "system entropy" (ES) theory to holistically and analytically quantify the interference in a datacenter to address this vital issue. The interference is caused by the scarcity of resources or/and the irrationality of scheduling. As more appropriate scheduling can compensate for resource scarcity, we derive the concept of "resource equivalence" to quantify the effectiveness of a resource scheduling strategy. We evaluate different resource scheduling strategies to validate the correctness and effectiveness of the proposed theory.Moreover, using the theory to eliminate interference, we propose a new resource scheduling strategy; i.e., ARQ, which dynamically allocates the isolated resources and the shared resources to simultaneously harvest the benefits of isolation and sharing. Our results show that compared to the state-of-the-art strategies (PARTIES and CLITE), ARQ is more effective to reduce the tail latency of the LC applications and to increase the IPC of the BE applications. Compared with PARTIES and CLITE, ARQ increases the yield (the ratio of satisfactory LC applications) by 25% and 20%, respectively; when the load is low, ARQ increases IPC of BE applications by 63.8% and 37.1%, respectively; ARQ reduces ES by 36.4% and 33.3%, respectively. The effectiveness of ARQ has saved resources significantly to achieve the same satisfactory overall user experience.
THE BIRTH AND DEATH EQUATION OF VIRUS SPREADING

Based on the complex network and non-equilibrium statistic theory, the birth and death equation (BDE) is proposed for the virus spreading on biological networks. This equation, in which the Susceptible Infected Susceptible model is extended, can predict the distribution rule of infection density by generating function. It is a better approach to a real infection process.
29.3 An 8.09TOPS/W Neural Engine Leveraging Bit-Sparsified Sign-Magnitude Multiplications and Dual Adder Trees

The computational complexity of neural networks (NNs) continues to increase, spurring the development of high-efficiency neural accelerator engines. Previous neural engines have relied on two's-complement (2C) arithmetic for their central MAC units (Fig. 29.3.1 top, left). However, gate-level simulations show that sign-magnitude (SM) multiplication is significantly more energy efficient; ranging from 35% (with uniformly distributed operands) to 67% (with normally distributed operands $(\mu={0}, {\sigma=25})$). The drawback of sign-magnitude number representation is that SM addition incurs significant overhead in terms of energy consumption and area, requiring upfront comparison of the sign bits and muxing/control to appropriately select between addition and subtraction (Fig. 29.3.1 center, left). This SM addition overhead substantially offsets the gains from SM multiplication in general purpose computing. One recent effort [1] to employ SM representation in neural computation achieved modest energy improvement at the cost of $2.5\times$ area increase due to full duplication of the MAC units, which would typically be unacceptable for area-/cost-sensitive IoT applications.
Reflectionless Bandstop Filter Based on Suspended Microstrip Line

In this report, a suspended microstrip line dual-port reflectionless bandstop filter is designed. The filter consists of a bandstop section loaded with open branch lines on the $\lambda \mathrm{g}/4$ transmission line and a bandpass section loaded with terminating resistors at the input/output ports, where the reflected signals are absorbed by the resistors to achieve the two-port non-reflection characteristic. The fractional bandwidth of this filter is 38.9%, the attenuation of $\boldsymbol{S}_{11}$ and $\boldsymbol{S}_{22}$ is greater than 10.2dB in the 0.5-6.8GHz frequency band, and the filter has a wide non-reflection frequency band.
A 28nm 16.9-300TOPS/W Computing-in-Memory Processor Supporting Floating-Point NN Inference/Training with Intensive-CIM Sparse-Digital Architecture

Computing-in-memory (CIM) has shown high energy efficiency on low-precision integer multiply-accumulate (MAC) [1–3]. However, implementing floating-point (FP) operations using CIM has not been thoroughly explored. Previous FP CIM chips [4–5] require either complex in-memory FP logic or have lengthy alignment-cycle latencies arising from converting FP data having different exponents into integer data. The challenges for an energy-efficient and accurate FP CIM processor are shown in Fig. 16.3. 1. Firstly, aligning an FP vector onto a CIM module requires a long bit-serial sequence due to infrequent but long tail values, incurring many CIM cycles. In this work, we observe that most exponents of FP data are clustered in a small range, which motivates dividing FP operations into high-efficiency intensive-CIM and flexible sparse-digital parts. Secondly, to implement the intensive-CIM + sparse-digital FP workflow, a sparse digital core is required for flexible intensive/sparse processing. Thirdly, the FP alignment brings more random sparsity. Though analog CIM can utilize random sparsity with a low-resolution ADC, the corresponding sparse strategy for digital CIM has not been explored.
Succincter

We can represent an array of n values from {0,1,2} using ceil(n log2 3) bits (arithmetic coding), but then we cannot retrieve a single element efficiently. Instead, we can encode every block of t elements using ceil(t log2 3) bits, and bound the retrieval time by t. This gives a linear trade-off between the redundancy of the representation and the query time.In fact, this type of linear trade-off is ubiquitous in known succinct data structures, and in data compression. The folk wisdom is that if we want to waste one bit per block, the encoding is so constrained that it cannot help the query in any way. Thus, the only thing a query can do is to read the entire block and unpack it.We break this limitation and show how to use recursion to improve redundancy. It turns out that if a block is encoded with two (! ) bits of redundancy, we can decode a single element, and answer many other interesting queries, in time logarithmic in the block size.Our technique allows us to revisit classic problems in succinct data structures, and give surprising new upper bounds. We also construct a locally-decodable version of arithmetic coding.
Persistency of excitation results for structured nonminimal models

It is frequently convenient to use specially structured nonminimal models for parameter estimation such as in the case of direct adaptive control where the model is parameterized in terms of the desired control law parameters. This is done, for example, in direct model reference adaptive control and in direct pole assignment adaptive control algorithms. It is shown that the parameters appearing in these nonminimal models can be uniquely estimated if and only if a certain design identity has a unique solution. The result is used to develop persistency of excitation results for these models. >
Study of efficiency droop in InGaN/GaN light emitting diodes with V-shape pits

We invesstagated the relationship between the emission efficiency of InGaN/GaN multiple quantum wells (MQWs) and the V-shape pits (V-pits) forming along the threading dislocation (TD). The thinner InGaN/GaN MQWs on the side walls around V-pits would create higher local energy barriers, which can resist the carriers trapped into the non-radiative recombination centres within TDs. By inserting different InGaN/GaN superlattice (SLS) layers below the MQWs, sizes of V-pits could be properly controlled. It was found that the V-pit size on InGaN MQWs increased with increasing SLS layers, which could decrease energy barriers. On the contrary, the shorter distance between the TD center and V-pit boundary would increase the carrier capturing capability of TDs in smaller V-pits. By properly controlling the V-shape defect formation, the best internal quantum efficiency of about 70%f was found in the MQWs with underlying 15 periods SLS layers.
Flexible transcutaneous transformer for artificial heart system

A flexible transcutaneous transformer utilizing amorphous magnetic fiber for an artificial heart system is reported. The transformer can transmit electrical energy of 20 W with an efficiency of over 90%; the primary current density does not greatly depend on the relative displacement of the coils. The temperature rise of the transformer was about 6 degrees C in a phantom test. >
Recursive labelling systems and stability of recursive structures in hyperarithmetical degrees

We show that, under certain assumptions of recursiveness in 2t, the recursive structure 2t is AO-stable for ca w, we need to deal with limit ordinals, and we frame an analogous result [Proposition 2] for (-yn)-systems where (-yn) is an increasing sequence of ordinals. Propositions 1 and 2 are then established by the
Optimization of modulation bandwidth in DBR lasers with detuned Bragg reflectors

The dynamical behavior of distributed Bragg reflector lasers with detuned Bragg reflectors is investigated theoretically. The model is based on the traveling wave equations, which are solved by expanding the solution in terms of the longitudinal eigenmodes. It is shown that for a drastic enhancement of the modulation bandwidth the interplay of the dominant mode and one side mode has to be enforced. Under these conditions, the modulation bandwidth can be enhanced to more than 70 GHz.
PROCEEDINGS of the HUMAN FACTORS SOCIETY 34th ANNUAL MEETING-1990 A Comparison of Space-Based and Object-Based Models of Visual Attention

In the present study we examined the degree to which contour and color could be used to minimize focused attention costs. Twelve subjects performed a task in which they were instructed to respond to a centrally located stimulus and ignore flanking items. incompatible with the response of the target. Additionally, the flankers could be embedded in the same object as the target or embedded in different objects. When the target and flankers were embedded in the same object, performance was poorer when the target was surrounded by response incompatible items than when it was surrounded by compatible items. However, the response compatibility effect was eliminated when the target and flankers were embedded in different objects. The results are interpreted within a Hybrid Space/Object-based model of visual attention. The flankers could be either compatible or
DOPPLER SHIFTS IN ACTIVE REGION MOSS USING SOHO/SUMER

The velocity of the plasma at the footpoint of hot loops in active region cores can be used to discriminate between different heating frequencies. Velocities on the order of a few kilometers per second would indicate low-frequency heating on sub-resolution strands, while velocities close to zero would indicate high-frequency (steady) heating. To discriminate between these two values requires accurate velocity measurements; previous velocity measurements suffer from large uncertainties, mainly due to the lack of an absolute wavelength reference scale. In this paper, we determine the velocity in the loop footpoints using observations from Solar Ultraviolet Measurements of Emitted Radiation (SUMER) on Solar and Heliospheric Observatory. We use neutral spectral lines to determine the wavelength scale of the observations with an uncertainty in the absolute velocity of <3.5 km s−1 and co-aligned Transition Region and Coronal Explorer (TRACE) images to identify footpoint regions. We studied three different active regions and found average redshifts in the Ne viii 770 Å emission line (formed at 6 × 105 K) of 5.17 ± 5.37 km s−1 and average redshifts in the C iv 1548 and 1550 Å emission lines (formed at 1 × 105 K) of 13.94 ± 4.93 km s−1 and 14.91 ± 6.09 km s−1, respectively. We find no correlation between the brightness in the spectral line and the measured velocity, nor do we find correlation between the Ne viii and C iv velocities measured co-spatially and co-temporally. SUMER scanned two of the active regions twice; in those active regions we find positive correlation between the co-spatial velocities measured during the first and second scans. These results provide definitive and quantitative measurements for comparisons with simulations of different coronal heating mechanisms.
On the microscopic theory of the magnetoelectric effect

Abstract This is a tutorial paper. We first consider why one should be interested in the origin of the magnetoelectric effect in ordered magnetic compounds. The non-zero elements of the tensor may be deduced from group theory arguments alone. A microscopic understanding is important if one wishes to learn which systems are likely to have large effects and possibly to design new combinations of materials which should show strong or unusual effects. It also contributes to the overall understanding of the materials involved. Another important feature is that different microscopic origins do give rise to very different behaviour with temperature and hence a microscopic understanding of a particular material is essential to understand the temperature dependence of the magnetoelectric tensor. This is particularly important if one actually has the situation in which the magnetoelectric effect may be used to measure a critical exponent just below the transition temperature. A final reason for being interested in .
Quantification of model uncertainty from experimental data: a mixed deterministic-probabilistic approach

In this paper a procedure is presented to obtain an upper bound on the modelling error for a reduced order finite impulse response (FIR) estimate of the transfer function of a linear system, using only minor a priori information. By applying a procedure similar to Bartlett's procedure of periodogram averaging to the FIR estimate, in conjunction with a periodic input signal, the statistics of the modelling error asymptotically can be obtained from the data. The modelling error consists of two parts: an averaging (probabilistic) part, due to the stochastic noise disturbance on the data, and a worst case (deterministic) part, due to the unmodelled dynamics. The latter is explicitly bounded with a hard error bound, while for the former a confidence interval can be specified asymptotically. The resulting error bounds appear to be highly realistic and, as a consequence, suitable for high performance robust control design purposes. <<ETX>>
Population extinction in discrete-time stochastic population models with an Allee effect

The Allee effect is often modeled as a threshold level below which there is population extinction. A minimum population size is required for population persistence. The Allee effect has been primarily studied in deterministic models. In this investigation, we develop two discrete-time stochastic population models with an Allee effect. The stochastic models are discrete-time Markov chains with demographic stochasticity. They are based on two well-known deterministic discrete-time population models. It is shown that the conditional means of the stochastic models follow the solution dynamics of the underlying deterministic models. However, near the Allee threshold value, the dynamics of the deterministic and stochastic models differ significantly. The first model is based on the well-known Ricker population model with an Allee effect. The second model is more complex. The population is subdivided according to mating status of adults and is based on a model developed for the northern spotted owl. The dynamics of the underlying deterministic models are reviewed first, then the stochastic models are formulated. The stochastic models are new formulations. Our goal is to study the probability of population extinction in the stochastic models.
Masses and Mass-To-Light Ratios of Galaxies

Is there more to a galaxy than meets the eye (or can be seen on a photo­ graph)? Many decades ago, Zwicky (1933) and Smith (1936) showed that if the Virgo cluster of galaxies is bound, the total mass must considerably exceed the sum of the masses of the individual member galaxies; i.e. there appeared to be "missing mass" in the cluster. As more data became avail­ able, the discrepancy persisted between masses of individual galaxies determined from optical rotation curves and the larger average galaxy mass needed to bind groups and clusters (e.g. Neyman, Page & Scott 1961). Recently, however, new information has pointed toward larger total masses for individual galaxies, thus decreasing the traditional discrepancy between various methods of mass measurement. Arguing that thin self­ gravitating stellar disks are unstable against bar-like modes, Ostriker & Peebles (1973) suggested that the disks of normal spiral galaxies must be imbedded in optically undetected, stabilizing massive halos. Ostriker, Peebles & Yahil (1974) and Einasto, Kaasik & Saar (1974) collected observational evidence in support of the existence of such halos (although Burbidge 1975 used similar data to reach the opposite conclusion). At nearly the same time, h igh-resolution 2 1-cm observations of nearby galaxies were showing that H I often extends well beyond the optical
Asymptotic root loci of multivariable linear optimal regulators

The asymptotic loci of the closed-loop poles of the multivariable time-invariant linear regulator are considered as the weight on the input in the criterion approaches zero. It is proved that those poles that go to infinity group into several Butterworth configurations of different orders and with different radii. It is furthermore shown that the first-order patterns are easily explicitly determined. Some examples illustrate the results.