6,935 research outputs found
3D Path Planning and Obstacle Avoidance Algorithms for Obstacle-Overcoming Robots
This article introduces a multimodal motion planning (MMP) algorithm that
combines three-dimensional (3-D) path planning and a DWA obstacle avoidance
algorithm. The algorithms aim to plan the path and motion of
obstacle-overcoming robots in complex unstructured scenes. A novel A-star
algorithm is proposed to combine the characteristics of unstructured scenes and
a strategy to switch it into a greedy best-first strategy algorithm. Meanwhile,
the algorithm of path planning is integrated with the DWA algorithm so that the
robot can perform local dynamic obstacle avoidance during the movement along
the global planned path. Furthermore, when the proposed global path planning
algorithm combines with the local obstacle avoidance algorithm, the robot can
correct the path after obstacle avoidance and obstacle overcoming. The
simulation experiments in a factory with several complex environments verified
the feasibility and robustness of the algorithms. The algorithms can quickly
generate a reasonable 3-D path for obstacle-overcoming robots and perform
reliable local obstacle avoidance under the premise of considering the
characteristics of the scene and motion obstacles.Comment: 2nd IEEE International Conference on Electronic Communications,
Internet of Things and Big Data Conference 2022 (IEEE ICEIB 2022
Evaluating and Enhancing Large Language Models for Conversational Reasoning on Knowledge Graphs
The development of large language models (LLMs) has been catalyzed by
advancements in pre-training techniques. These models have demonstrated robust
reasoning capabilities through manually designed prompts. In this work, we
evaluate the conversational reasoning capabilities of the current
state-of-the-art LLM (GPT-4) on knowledge graphs (KGs). However, the
performance of LLMs is constrained due to a lack of KG environment awareness
and the difficulties in developing effective optimization mechanisms for
intermediary reasoning stages. We further introduce LLM-ARK, a LLM grounded KG
reasoning agent designed to deliver precise and adaptable predictions on KG
paths. LLM-ARK leverages Full Textual Environment (FTE) prompt to assimilate
state information within each reasoning step. We reframe the challenge of
multi-hop reasoning on the KG as a sequential decision-making task. Utilizing
the Proximal Policy Optimization (PPO) online policy gradient reinforcement
learning algorithm, our model is optimized to learn from rich reward signals.
Additionally, we conduct an evaluation of our model and GPT-4 on the OpenDialKG
dataset. The experimental results reveal that LLaMA-2-7B-ARK outperforms the
current state-of-the-art model by 5.28 percentage points, with a performance
rate of 36.39% on the target@1 evaluation metric. Meanwhile, GPT-4 scored
14.91%, further demonstrating the effectiveness of our method. Our code is
available on GitHub (https://github.com/Aipura/LLM-ARK) for further access
Activity modulation and allosteric control of a scaffolded DNAzyme using a dynamic DNA nanostructure.
Recognition of the fundamental importance of allosteric regulation in biology dates back to not long after its discovery in the 1960s. Our ability to rationally engineer this potentially useful property into normally non-allosteric catalysts, however, remains limited. In response we report a DNA nanotechnology-enabled approach for introducing allostery into catalytic nucleic acids. Specifically, we have grafted one or two copies of a peroxidase-like DNAzyme, hemin-bound G-quadruplex (hemin-G), onto a DNA tetrahedral nanostructure in such a manner as to cause them to interact, modulating their catalytic activity. We achieve allosteric regulation of these catalysts by incorporating dynamically responsive oligonucleotides that respond to specific "effector" molecules (complementary oligonucleotides or small molecules), altering the spacing between the catalytic sites and thus regulating their activity. This designable approach thus enables subtle allosteric modulation in DNAzymes that is potentially of use for nanomedicine and nanomachines
International Conference «Tumor Hypoxia and Malignant Progression». October 1–4, 2008, House of Scientists of NASU, Kiev, Ukraine
Tumor hypoxia: pathophysiological and molecular mechanisms; Hypoxia and HIF-1: role in tumor progression; Evaluation of tumor oxygenation; Hypoxia-modulated tumor stroma; Hypoxia and glycolysis in tumor: mechanisms of interrelationship;Hypoxia and tumor-host interface; Hypoxia-induced metastasis; Tumor hypoxia: therapeutic resistance and hypoxia-related therapies; Hypoxia and prognosis of clinical outcom
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