Enhancing the landing guidance of a reusable launch vehicle by improving genetic algorithm-based deep reinforcement learning using Hybrid Deterministic-Stochastic algorithm.

The PbGA-DDPG algorithm, which uses a potential-based GA-optimized reward shaping function, is a versatiledeep reinforcement learning/DRLagent that can control a vehicle in a complex environment without prior knowledge. However, when compared to an established deterministic controller, it consistently falls short in terms of landing distance accuracy. To address this issue, the HYDESTOC Hybrid Deterministic-Stochastic (a combination of DDPG/deep deterministic policy gradient and PID/proportional-integral-derivative) algorithm was introduced to improve terminal distance accuracy while keeping propellant consumption low. Results from extensive cross-validated Monte Carlo simulations show that a miss distance of less than 0.02 meters, landing speed of less than 0.4 m/s, settling time of 20 seconds or fewer, and a constant crash-free performance is achievable using this method.

Sludge interface measurement in the storage tank utilizing neutron backscattering technique: A field experiment.

Modern industrial plant operations commonly necessitate a measurement system of the liquids level interface in the oil storage tank. Various advanced-level indicators almost meet the demand, but these may not be in online condition and are less accurate due to sedimentation in the bottom tank. Sedimentation or sludge known as a petroleum hydrocarbons complex emulsion, contained water and solid particles generated during distribution, storage, or even production. The neutron backscatter technique can help the maintenance system of the tank or vessel by measuring sludge levels from outside the wall. This paper presents a non-intrusive method for identifying the interface between two materials in the crude oil storage system. A fast neutron source (241Am-Be) with activity 1 Ci (Ci) and a portable backscattering neutron detector are used for storage tank measurement. The storage tank has an outer diameter (OD) of 34 m and a height of 11 m. Time measurement is 2 s for each position, starting from 0 m to 11 m. The slow neutron intensity can be correlated to the hydrogen concentration inside chemical compounds. The interface between sludge and oil is identified at 27 cm from the bottom plate. The method has the potential for non-destructive measurement of sludge in a refinery facility.

Development of implant movement checker for determining dental implant stability.

Noninvasive and nondestructive mobility assessment of dental implants is very important and useful for dental implantation diagnostic-aids. The development of implant movement (IM) checker based on microcontroller is presented in this paper. Data acquisition system and bender-type piezoelectric probe were used to improve measurement quality to the original tooth mobility (TM) tester. The adoption of a microcontroller and the use of a dental drill-sized measuring probe were sufficient in the reproducibility and reliability of the IM checker. When the implant was subjected to a constant force and amplitude, the acceleration of the model was detected using the measuring probe. The data acquisition system controlled for obtaining the appropriate acceleration signals based on the preload detection during measurement. Dental implant models of Molteno and Rigolac were made at different stiffness and were used to verify the reliability and validity of measurements. The values of measurements obtained by the IM checker were reliable and precise. The maximum error for perpendicular measurements was less than 12% measured by a new operator and decreased to 2% by an experienced operator. The IM checker was applied to monitor the stability of dental implantation, which compared the relative IM score of the new 5[see text] implant with the adjacent old 6 [see text] implant that had been used functionally for 3 years.

Development of dental implant movement (IM) checker for dental implant mobility assessment.

This study aimed at developing a dental implant movement (IM) checker for assessing quantitative dental implant mobility. The design of the instrument was based on the tooth mobility (TM) tester, which was previously developed by our group. The IM checker consists of a newly developed measuring probe which has the size of a typical dental drill so that it would be easy to measure at all regions of dental implants. The probe has a bimorph ceramics transducer for actuating an implant at constant frequency and force amplitude and for detecting acceleration response. A set of strain gauges were attached to the bimorph ceramics for detecting preload during measurement. A new digital data acquisition system was used to eliminate measurement artifacts mainly due to probe handling. The IM checker could discriminate the artificial dental implant models in the range of clinical tooth mobility M0 with variation less than 6%. The measuring time needed by five operators was less than 15 s. Accordingly, the IM checker has sufficient measuring reliability and therefore it could be introduced in dental clinics.