48 research outputs found
Unsupervised Sim-to-Real Adaptation of Soft Robot Proprioception using a Dual Cross-modal Autoencoder
Soft robotics is a modern robotic paradigm for performing dexterous
interactions with the surroundings via morphological flexibility. The desire
for autonomous operation requires soft robots to be capable of proprioception
and makes it necessary to devise a calibration process. These requirements can
be greatly benefited by adopting numerical simulation for computational
efficiency. However, the gap between the simulated and real domains limits the
accurate, generalized application of the approach. Herein, we propose an
unsupervised domain adaptation framework as a data-efficient, generalized
alignment of these heterogeneous sensor domains. A dual cross-modal autoencoder
was designed to match the sensor domains at a feature level without any
extensive labeling process, facilitating the computationally efficient
transferability to various tasks. As a proof-of-concept, the methodology was
adopted to the famous soft robot design, a multigait soft robot, and two
fundamental perception tasks for autonomous robot operation, involving
high-fidelity shape estimation and collision detection. The resulting
perception demonstrates the digital-twinned calibration process in both the
simulated and real domains. The proposed design outperforms the existing
prevalent benchmarks for both perception tasks. This unsupervised framework
envisions a new approach to imparting embodied intelligence to soft robotic
systems via blending simulation.Comment: 13 pages, 12 figure
A Compact Wideband Crossover Coupler with Lumped Elements
A compact wideband crossover coupler with fully lumped elements is presented. To achieve a wideband operation, a three-section branch-line structure is employed for the crossover coupler. The size is significantly minimized by replacing transmission lines with lumped elements. The measurement shows that the insertion loss, isolation, and return loss are 1.7 dB, 24 dB, and 14.5 dB, respectively, at 2 GHz. The fractional bandwidth of 20-dB isolation and 3-dB insertion loss is 27%. The size of the crossover coupler is 11 mm × 9 mm, which corresponds to 0.07λ × 0.06λ at 2 GHz. This is significantly smaller than a conventional three-section branch-line crossover coupler by 95%
Characterization of a bimorph deformable mirror using stroboscopic phase-shifting interferometry
A method to decipher pleiotropy by detecting underlying heterogeneity driven by hidden subgroups applied to autoimmune and neuropsychiatric diseases
There is growing evidence of shared risk alleles between complex traits (pleiotropy), including autoimmune and neuropsychiatric diseases. This might be due to sharing between all individuals (whole-group pleiotropy), or a subset of individuals within a genetically heterogeneous cohort (subgroup heterogeneity). BUHMBOX is a well-powered statistic distinguishing between these two situations using genotype data. We observed a shared genetic basis between 11 autoimmune diseases and type 1 diabetes (T1D, p0.2, 6,670 T1D cases and 7,279 RA cases). Genetic sharing between seronegative and seropostive RA (p<10−9) had significant evidence of subgroup heterogeneity, suggesting a subgroup of seropositive-like cases within seronegative cases (pBUHMBOX=0.008, 2,406 seronegative RA cases). We also observed a shared genetic basis between major depressive disorder (MDD) and schizophrenia (p<10−4) that was not explained by subgroup heterogeneity (pBUHMBOX=0.28 in 9,238 MDD cases)
Bottom-up solutions in a time of crisis: the case of Covid-19 in South Korea
Innovation systems have seen diverse actors attempting to tame the Covid-19 crisis, under varying degrees of government direction Largely neglected in scholarly and public attention, however, are ?bottom-up? solutions arising from the periphery of innovation systems Drawing on inductive case research on a fringe doctor who invented the idea of the drive-through testing system, and two university student teams that developed coronavirus applications, this study examines how peripheral actors generate innovative, bottom-up solutions at speed in a time of crisis Our findings reveal that, in a crisis situation, bottom-up solutions transpire on the basis of three innovation drivers: (a) peripheral status, expediting the commence of innovation activities;(b) interdisciplinary collaboration, enabling access to a greater spectrum of knowledge and perspectives;and (c) prior knowledge, prescribing the direction of solution generation We also identify that system intermediaries support the innovation activities of peripheral actors, thereby helping bottom-up solutions to become more customer facing Such functions of intermediaries include demand articulation, technical assistance, and promulgation of generated solutions Our findings offer theoretical implications for the literature on innovation in a time of crisis and practical implications for governments and organizations preparing themselves for the potential second wave of coronavirus emergencies, or even a completely new form of future crisi
Performance estimation of the lower limb exoskeleton for plantarflexion using surface electromyography (sEMG) signals
Development of a Dance Rehabilitation System using Kinect and a Vibration Feedback Glove
n this paper, a dance rehabilitation system using Kinect and a vibration feedback glove is proposed. The proposed system provides enjoyable and fun rehabilitation treatment by combining a markerless motion capture system, vibration feedback, and dance music. This system shows a sequence of arrows which are generated by dance music, and the patient is required to touch the arrows in appropriate timing. The patient's own motion is captured by Kinect, and provided to the patient in real-time as visual feedback. Also, the glove applies vibration feedback as he/she touches the arrows. The patient's movements are recorded and analyzed for improved rehabilitation program
A 28-Gb/s/pin PAM-4 Single-Ended Transmitter with High-Linearity and Impedance-Matched Driver and 3-Point ZQ calibration for Memory Interfaces
This paper presents a single-ended transmitter (TX) with a voltage-mode (VM) PAM-4 driver. The proposed driver simultaneously satisfies impedance matching and linearity, and occupies a small area without resistors and inductors. A ZQ calibration scheme that automatically and precisely adjusts the PAM-4 driver is also addressed. The proposed calibration has three calibration points, which allow the driver to have high linearity by taking into account the impedance variations of the TX and the receiver (RX) according to the output levels. The prototype chip is fabricated in 65 nm CMOS process and occupies 0.0333 mm(2). The proposed TX achieves a data rate of 28 Gb/s/pin with the level separation mismatch ratio (RLM) of 0.993 while consuming 0.64 pJ/b.N
Exploiting an Intermediate Latent Space between Photo and Sketch for Face Photo-Sketch Recognition
The photo-sketch matching problem is challenging because the modality gap between a photo and a sketch is very large. This work features a novel approach to the use of an intermediate latent space between the two modalities that circumvents the problem of modality gap for face photo-sketch recognition. To set up a stable homogenous latent space between a photo and a sketch that is effective for matching, we utilize a bidirectional (photo → sketch and sketch → photo) collaborative synthesis network and equip the latent space with rich representation power. To provide rich representation power, we employ StyleGAN architectures, such as StyleGAN and StyleGAN2. The proposed latent space equipped with rich representation power enables us to conduct accurate matching because we can effectively align the distributions of the two modalities in the latent space. In addition, to resolve the problem of insufficient paired photo/sketch samples for training, we introduce a three-step training scheme. Extensive evaluation on a public composite face sketch database confirms superior performance of the proposed approach compared to existing state-of-the-art methods. The proposed methodology can be employed in matching other modality pairs
A CMOS W-Band Amplifier with Tunable Neutralization Using a Cross-Coupled MOS–varactor Pair
This paper presents a CMOS W-band amplifier adopting a novel neutralization technique for high gain and stability. The W-band amplifier consists of four common-source differential gain cells that are neutralized by a cross-coupled MOS–varactor pair. Contrary to conventional neutralizations, the proposed technique enables tunable neutralization, so that the gate-to-drain capacitance of transistors is accurately tracked and neutralized as the varactor voltage is adjusted. This makes the neutralization tolerant of capacitance change caused by process–voltage–temperature (PVT) variation or transistor model inaccuracy, which commonly occurs at mm-wave frequencies. The proposed tunable neutralization is experimentally confirmed by measuring gain and stability of the W-band amplifier fabricated in a 65-nm CMOS process. The amplifier achieves a measured gain of 17.5 dB at 79 GHz and a 3-dB bandwidth from 77.5 to 84 GHz without any stability issue. The DC power consumption is 56.7 mW and the chip area is 0.85 mm2