8,870 research outputs found
Effective Viscous Damping Enables Morphological Computation in Legged Locomotion
Muscle models and animal observations suggest that physical damping is
beneficial for stabilization. Still, only a few implementations of mechanical
damping exist in compliant robotic legged locomotion. It remains unclear how
physical damping can be exploited for locomotion tasks, while its advantages as
sensor-free, adaptive force- and negative work-producing actuators are
promising. In a simplified numerical leg model, we studied the energy
dissipation from viscous and Coulomb damping during vertical drops with
ground-level perturbations. A parallel spring-damper is engaged between
touch-down and mid-stance, and its damper auto-disengages during mid-stance and
takeoff. Our simulations indicate that an adjustable and viscous damper is
desired. In hardware we explored effective viscous damping and adjustability
and quantified the dissipated energy. We tested two mechanical, leg-mounted
damping mechanisms; a commercial hydraulic damper, and a custom-made pneumatic
damper. The pneumatic damper exploits a rolling diaphragm with an adjustable
orifice, minimizing Coulomb damping effects while permitting adjustable
resistance. Experimental results show that the leg-mounted, hydraulic damper
exhibits the most effective viscous damping. Adjusting the orifice setting did
not result in substantial changes of dissipated energy per drop, unlike
adjusting damping parameters in the numerical model. Consequently, we also
emphasize the importance of characterizing physical dampers during real legged
impacts to evaluate their effectiveness for compliant legged locomotion
Synchronization Strings: Explicit Constructions, Local Decoding, and Applications
This paper gives new results for synchronization strings, a powerful
combinatorial object that allows to efficiently deal with insertions and
deletions in various communication settings:
We give a deterministic, linear time synchronization string
construction, improving over an time randomized construction.
Independently of this work, a deterministic time
construction was just put on arXiv by Cheng, Li, and Wu. We also give a
deterministic linear time construction of an infinite synchronization string,
which was not known to be computable before. Both constructions are highly
explicit, i.e., the symbol can be computed in time.
This paper also introduces a generalized notion we call
long-distance synchronization strings that allow for local and very fast
decoding. In particular, only time and access to logarithmically
many symbols is required to decode any index.
We give several applications for these results:
For any we provide an insdel correcting
code with rate which can correct any fraction
of insdel errors in time. This near linear computational
efficiency is surprising given that we do not even know how to compute the
(edit) distance between the decoding input and output in sub-quadratic time. We
show that such codes can not only efficiently recover from fraction of
insdel errors but, similar to [Schulman, Zuckerman; TransInf'99], also from any
fraction of block transpositions and replications.
We show that highly explicitness and local decoding allow for
infinite channel simulations with exponentially smaller memory and decoding
time requirements. These simulations can be used to give the first near linear
time interactive coding scheme for insdel errors
Rancang Bangun Sistem Distribusi Gas LPG 3 Kg Menggunakan RFID Pada E-KTP
Pengelolaan distribusi gas LPG 3 Kg pada masyarakat miskin tidak merata. Beberapa faktor penyebabnya yaitu harga gas LPG 3 Kg yang murah sehingga distribusi melebihi jatah yang disarankan. Hal tersebut mengakibatkan harga dan jumlah distribusi tidak seimbang terhadap distribusi perwilayah. Tujuan penelitian ini adalah merancang bangun sistem distribusi gas LPG 3 Kg menggunakan Radio Frequency Identification (RFID) pada E-KTP berbasis web untuk memudahkan dalam melakukan transaksi gas LPG 3 Kg dan mencegah terjadinya penimbunan gas LPG 3 Kg. Menggunakan metode penelitian studi kuantitatif yaitu studi experimental yang bertujuan untuk mengumpulkan informasi seputar permasalahan, penelitian ini juga menggunakan metode System Development Life Cycle (SDLC) model Waterfall, yaitu metode yang menggunakan teknik analisis, desain, pengodean, pengujian, dan pendukung. Hasil penelitian ini adalah suatu aplikasi untuk memanajemen penjualan gas LPG 3 Kg bersubsidi agar tidak terjadinya penimbunan disuatu pangkalan yang menyebabkan ketidak seimbangan terhadap distribusi
Ultra-thin titanium nitride films for refractory spectral selectivity
We demonstrate a selectively emitting optical Fabry-P\'erot resonator based
on a few-nm-thin continuous metallic titanium nitride film, separated by a
dielectric spacer from an optically thick titanium nitride back-reflector,
which exhibits excellent stability at 1070 K against chemical degradation,
thin-film instabilities and melting point depression. The structure paves the
way to the design and fabrication of refractory thermal emitters using the
well-established processes known from the field of multilayer and rugate
optical filters. We demonstrate that a few-nanometer thick films of titanium
nitride can be stable under operation at temperatures exceeding 1070 K. This
type of selective emitter provides a means towards near-infrared thermal
emission that could potentially be tailored to the accuracy level known from
rugate optical filters.Comment: 16 pages, 6 figure
Jurassic World Remake: Bringing Ancient Fossils Back to Life via Zero-Shot Long Image-to-Image Translation
With a strong understanding of the target domain from natural language, we
produce promising results in translating across large domain gaps and bringing
skeletons back to life. In this work, we use text-guided latent diffusion
models for zero-shot image-to-image translation (I2I) across large domain gaps
(longI2I), where large amounts of new visual features and new geometry need to
be generated to enter the target domain. Being able to perform translations
across large domain gaps has a wide variety of real-world applications in
criminology, astrology, environmental conservation, and paleontology. In this
work, we introduce a new task Skull2Animal for translating between skulls and
living animals. On this task, we find that unguided Generative Adversarial
Networks (GANs) are not capable of translating across large domain gaps.
Instead of these traditional I2I methods, we explore the use of guided
diffusion and image editing models and provide a new benchmark model,
Revive-2I, capable of performing zero-shot I2I via text-prompting latent
diffusion models. We find that guidance is necessary for longI2I because, to
bridge the large domain gap, prior knowledge about the target domain is needed.
In addition, we find that prompting provides the best and most scalable
information about the target domain as classifier-guided diffusion models
require retraining for specific use cases and lack stronger constraints on the
target domain because of the wide variety of images they are trained on.Comment: 9 pages, 10 figures, ACM Multimedia 202
A one-dimensional coordination polymer constructed from cadmium(II) cations and sparfloxacinate anions
Peer reviewedPublisher PD
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