56 research outputs found
Training microrobots to swim by a large language model
Machine learning and artificial intelligence have recently represented a
popular paradigm for designing and optimizing robotic systems across various
scales. Recent studies have showcased the innovative application of large
language models (LLMs) in industrial control [1] and in directing legged
walking robots [2]. In this study, we utilize an LLM, GPT-4, to train two
prototypical microrobots for swimming in viscous fluids. Adopting a few-shot
learning approach, we develop a minimal, unified prompt composed of only five
sentences. The same concise prompt successfully guides two distinct articulated
microrobots -- the three-link swimmer and the three-sphere swimmer -- in
mastering their signature strokes. These strokes, initially conceptualized by
physicists, are now effectively interpreted and applied by the LLM, enabling
the microrobots to circumvent the physical constraints inherent to
micro-locomotion. Remarkably, our LLM-based decision-making strategy
substantially surpasses a traditional reinforcement learning method in terms of
training speed. We discuss the nuanced aspects of prompt design, particularly
emphasizing the reduction of monetary expenses of using GPT-4
An Agent Approach to Spatial Information Grid Architecture Design
Spatial information grid (SIG) is a spatial information infrastructure that has the capability of providing services on-demand. SIG is a distributed network environment, which links spatial data resources, computing resources, storage resources, software, tools and users. SIG can integrate massive distributed heterogeneous spatial information resources, provides uniform management and process, and, furthermore, coordinate different resources to complete large-scale and complex spatial tasks and applications. In this paper, agent technology is adopted to construct a SIG framework, which contains three layers: users/applications layer, agent services layer and information layer. Different applications can get their spatial information via agent services, and agent services make the procedure of navigating and accessing spatial information transparent to users. Also, the implementation issues of the framework are discussed in detail, including Geo-Agents, an agent-based distributed GIS system, spatial information management, collaboration and parallel mechanism, load control strategy, and a sample
A Hierarchical Component-based WebGIS and Its Key Technologies
A practical hierarchical component-based WebGIS model referred to as Geo-Union is presented. Geo-Union consists of four layers: storage layer, service layer, component layer and application layer. Service layer is partitioned into another two layers: Geo-Union client and Geo-Union server. The architectures and object diagram of each layer in Geo-Union are discussed in details. After that, four key technologies adopted in Geo-Union (spatial data model, ORDB, spatial index and spatial cache) are summarized and analyzed, especially the spatial cache framework of Geo-Union. At last, some future works in WebGIS, such as interoperability, security, distributed computing and intelligent computing, are indicated and simply explored
Multi-layer reconstruction of skull base after endoscopic transnasal surgery for invasive pituitary adenomas
Objective. To explore the efficacy of multi-layer skull base reconstruction after endoscopic transnasal surgery for invasive pituitary adenomas (IPAs).
Clinical rationale for the study. Skull base reconstruction for IPAs.
Material and methods. This retrospective analysis involved 160 patients with IPAs who underwent operations from October 2018 to October 2020. All patients were diagnosed with IPAs by pituitary enhanced magnetic resonance imaging, and all tumours were confirmed to be Knosp grades 3a, 3b, or 4. The experimental group and the control group comprised 80 patients in each, and we used different methods to reconstruct the skull base in each group. The comparison indicators included cerebrospinal fluid leakage, sellar floor bone flap (or middle turbinate) shifting, delayed healing of the skull base reconstructed tissue, nasal discomfort, and epistaxis. We used the chi-square test, and p < 0.05 was considered statistically significant.
Results. In the experimental group, cerebrospinal fluid leakage occurred intraoperatively in 73 patients, two of whom had cerebrospinal fluid leakage postoperatively. Brain CT 12 months postoperatively showed no sellar floor bone flap (or middle turbinate) shifting. Endoscopic transnasal checks performed seven days after surgery showed that the skull base reconstructed tissue had healed in 74 patients and had failed to heal in six. However, endoscopic transnasal checks showed that all six of these patientsβ pedicled nasoseptal flaps had healed well by 14 days after surgery. Other sequelae comprised nasal discomfort in four patients, and epistaxis in four. In the control group, cerebrospinal fluid leakage occurred intraoperatively in 71 patients, 14 of whom had cerebrospinal fluid leakage postoperatively. Brain CT 12 months postoperatively showed floor bone flap (or middle turbinate) shifting in 12 patients. Endoscopic transnasal checks performed seven days after surgery showed that the skull base reconstructed tissue had healed in 65 patients. In 12 patients, pedicled nasoseptal flaps had healed well by 14 days after surgery, while the remaining three patients required reoperation. Other sequelae comprised nasal discomfort in five patients, and epistaxis in six.
Conclusions. This new method of multi-layer skull base reconstruction could play an important role in endoscopic transnasal IPA surgery
Association of GSTM1 Null Allele with Prostate Cancer Risk: Evidence from 36 Case-Control Studies
WOS:000312385200061Peer reviewe
Recommended from our members
Noise Perception in Immersive Virtual Reality Enables Faster Stroke Diagnosis Time with Holoportation-Integrated Remote Evaluation
Until now, most telemedicines were typically based on synchronous audiovisual communication, which limited the ability of medical experts to work with patients efficiently and effectively in physical tasks, such as stroke diagnosis. HoloSTRokE, or Holoportation-integrated Stroke Team Remote Evaluation, is the project designed primarily as an observational study of enhanced video techniques layered onto an already existing telemedicine for the acute stroke evaluation pathway. Patients will be provided the opportunity to have their image projected via Holoportation (like a hologram) to the consulting provider, and vice versa. This research introduces noise level optimization for holoportation to minimize the uncanny or strangely familiar feelings of eeriness and revulsion in observers as patients. Hence, the setup time and the fidelity of the reprojected avatar resembling actual human beings are significantly reduced compared to previous research, which requires enormous effort in streaming high fidelity point cloud segmentation throughout the specific-configured network. The research expands the delivery of care for patients who are possibly experiencing a stroke with less mental demanding and higher success rate of diagnosis procedure
Role of Nitrogen on the Mechanical Properties of the Novel Carbon Nitride Nanothreads
Carbon nanothread (C-NTH) is a new ultrathin one-dimensional sp3 carbon nanostructure, which exhibits promising applications in novel carbon nanofibers and nanocomposites. Recently, researchers have successfully developed a new alternative structure - ultrathin carbon nitride nanothread (CN-NTH). In this work, we investigate the mechanical properties of CN-NTHs through large-scale molecular dynamics simulations. Comparing with their C-NTH counterparts, CN-NTHs are found to exhibit a higher tensile and bending stiffness. In particular, because of the bond redistribution, the CN-NTHs in the polymer I group and tube (3,0) group are found to possess a higher failure strain than their C-NTH counterparts. However, the CN-NTH in the polytwistane group has a smaller failure strain compared with the pristine C-NTH. According to the atomic configurations, the presence of nitrogen atoms always leads to stress/strain concentrations for the nanothreads under tensile deformation. This study provides a comprehensive understanding of the mechanical properties of CN-NTHs, which should shed light on their potential applications such as fibers or reinforcements for nanocomposites.</p
- β¦