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1
Carton, Geoffrey, J. C. King e R. Josh Bowers. "Munitions-Related Technology Demonstrations at Ordnance Reef (HI-06), Hawaii". Marine Technology Society Journal 46, n. 1 (1 gennaio 2012): 63–82. http://dx.doi.org/10.4031/mtsj.46.1.9.
Testo completoAbstract (sommario):
AbstractDevelopment of methods and technologies to characterize sites with underwater military munitions (UWMM) and respond to UWMM where the risks posed to human health or the environment or explosive hazards are unacceptable is underway. Department of Defense Military Munitions Sea Disposal Site Hawaii (HI-06), referred to locally as Ordnance Reef, is off Oahu’s leeward coast. This site has become the focal point for research on UWMM. Past studies found that the site presents no immediate danger to public safety. The location and water depth at this site present advantages for UWMM research and development.Promising technologies demonstrated at Ordnance Reef (HI-06) include those for munitions recovery, at-sea demilitarization, nondestructive testing, and explosives detection. Studies on fate and transport of munitions-related compounds and corrosion are ongoing.Among these technologies are the Remotely Operated Underwater Munitions Recovery System (ROUMRS) and the Explosive Hazard Demilitarization System (EHDS). Both are assemblages of commercial off-the-shelf components, and each is housed in a standard 6-m International Organization for Standardization (ISO) shipping container and can be operated on a barge.ROUMRS consists of a remotely operated vehicle, manipulators, an interface between a precision GPS, and underwater navigation equipment used during recovery of UWMM. The system also transports recovered UWMM for treatment. The EHDS consists of a portable X-ray unit to allow positive identification of recovered munitions, remotely operated wet band saws to cut recovered munitions to expose their explosive fill, and low-temperature ovens to treat the exposed explosives, making the remaining material safe for recycling.
2
O, Tărăbuță. "A Study of the Feasibility of Autonomous Underwater Vehicles and Remotely Operated Vehicles in Black Sea". Scientific Bulletin of Naval Academy XIX, n. 1 (15 luglio 2018): 440–47. http://dx.doi.org/10.21279/1454-864x-18-i1-067.
Testo completoAbstract (sommario):
An underwater vehicle designed for industrial use in the Black Sea has to tackle two specific characteristics of it, given by its enclosed nature: the strong vertical stratification and the high content of hydrogen sulfide at greater depths. These particular environmental conditions impose also new approaches of design and technology for construction. The innovation foreseen of our study is the very concept of a universal underwater vehicle, based on modular design. Currently, unmanned underwater vehicles are controlled in two main ways, either autonomously (AUV) or by data transfer through an umbilical cable (ROV). Despite the fact AUV and ROV have many common characteristics they are used separately and are disjoint throughout their life cycle. To increase the technical performances and economic efficiency of such vehicles, we planned to design a universal carrier platform able to support different modules. Based on the common carrier sub-system, DCUV (Dual Controlled Underwater Vehicles) can be assembled as an AUV, controlled autonomously and by radio when surfaced. After its recovery and transfer of the sea data recorded during its evolution as an AUV, the specific modules (sensors and battery) are replaced with functional modules needed to change it into an ROV, which can be then remotely controlled towards the contacts of interest. The concept of providing DCUV with a common propulsion unit will be eased by designing of an innovative multi-control system that will integrate data from sensors and human operator with the propulsion motors and end effectors, based on state-of- the-art microcontrollers and their appropriate programming.
3
Chen, Le, Zhipeng Lin, Taiju Yin, Zhongchao Li, Chunsheng Shen e Bobo Luo. "Analysis of Reservoir Architecture of Shallow-water Delta Front Based on Process—A Case of S2L410 in Southern 79 Block in Wennan Oilfield". Studies in Engineering and Technology 4, n. 1 (30 luglio 2017): 96. http://dx.doi.org/10.11114/set.v4i1.2530.
Testo completoAbstract (sommario):
The sand body distribution is relatively limited in this block, the lens-shaped sandbodies are more developed, the change of intergranular sandbody is fast and the internal architecture of the sand body is complex, which results in the difficulties of the arrangement of horizontal wells in the study area and the tapping of remaining oil in high water reservoirs. In this paper, taking an example of S2L410 sandbodies in Wen 79 Southern Block, rich drilling data, core data, logging data and geological research results accumulated over many years in Wennan Oilfield were applied to discuss the anatomical method of the reservoir architecture unit in the underwater distributary channel in the shallow delta front, the hierarchy of the internal architecture of the reservoir and the anatomy of the single sand body. On the basis of this, the sequence of the underwater distributary channel in the composite channel is determined by the cross section and the source profile. Under the guidance of the sedimentology principle, the formation process of the underwater distributary channel is restored and the evolution process of underwater distributary channel is recovered.
4
Popov, Vladimir Vladimirovich, Aleksandra Vitalievna Ivanovskaya, Valentin Leonidovich Erofeev e Elena Vladimirovna Bogatyreva. "Specific features of methodology for conducting experimental studies of adaptive control system of ship lifting devices". Vestnik of Astrakhan State Technical University. Series: Marine engineering and technologies 2022, n. 3 (23 agosto 2022): 40–49. http://dx.doi.org/10.24143/2073-1574-2022-3-40-49.
Testo completoAbstract (sommario):
Lowering and recovery operations, as well as towing underwater and surface objects are carried out with the help of a ship winch. As a result of the impact of any external disturbances, longitudinal oscillations appear in the towing rope, whose resonant maxima may fall into the vessel’s frequency range. The longer the cable, the greater the number of resonant frequencies in the operating range. Such operating conditions of the ship’s lifting equipment have a negative impact on the operation of the ship’s power plant as a whole. In order to increase the reliability of deck lifting equipment it is proposed to use an adaptive control system that would respond in a timely manner to changes in loading. Lifting equipment of a fishing vessel with non-stationarity of dynamic processes in operation is considered as an application of such a system. There is considered a principle of operation of the adaptive hydraulic drive of a trawl winch. The important scientific and technical problem of developing a complex mathematical model of the above control system has been solved. The directions of experimental research are determined. There is proposed a laboratory unit to evaluate the influence of the parameters of a mechanical system on the dynamics of a hydraulic drive of a load-lifting device adaptive to load variability. The unit operates due to changing the number and weight of the load discs installed on the driving and driven pulleys and simulating a change in the inertial coefficient, which is typical for a trawl winch. The second direction of experimental research is the verification of the adequacy of the obtained mathematical models. There are presented the results of the verification in the form of calculated and averaged experimental dynamometer cards, which are well correlated, with deviation up to 8%.
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Wang, Zhenfei, Meixin Hu e Ketao Zhang. "Underwater Turbid Media Stokes-Based Polarimetric Recovery". Sensors 24, n. 5 (20 febbraio 2024): 1367. http://dx.doi.org/10.3390/s24051367.
Testo completoAbstract (sommario):
Underwater optical imaging for information acquisition has always been an innovative and crucial research direction. Unlike imaging in the air medium, the underwater optical environment is more intricate. From an optical perspective, natural factors such as turbulence and suspended particles in the water cause issues like light scattering and attenuation, leading to color distortion, loss of details, decreased contrast, and overall blurriness. These challenges significantly impact the acquisition of underwater image information, rendering subsequent algorithms reliant on such data unable to function properly. Therefore, this paper proposes a method for underwater image restoration using Stokes linearly polarized light, specifically tailored to the challenges of underwater complex optical imaging environments. This method effectively utilizes linear polarization information and designs a system that uses the information of the first few frames to calculate the enhanced images of the later frames. By doing so, it achieves real-time underwater Stokes linear polarized imaging while minimizing human interference during the imaging process. Furthermore, the paper provides a comprehensive analysis of the deficiencies observed during the testing of the method and proposes improvement perspectives, along with offering insights into potential future research directions.
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Xue, Teng, Tianchi Zhang e Jing Zhang. "Research on Underwater Image Restoration Technology Based on Multi-Domain Translation". Journal of Marine Science and Engineering 11, n. 3 (22 marzo 2023): 674. http://dx.doi.org/10.3390/jmse11030674.
Testo completoAbstract (sommario):
Underwater images are crucial in various underwater applications, including marine engineering, underwater robotics, and subsea coral farming. However, obtaining paired data for these images is challenging due to factors such as light absorption and scattering, suspended particles in the water, and camera angles. Underwater image recovery algorithms typically use real unpaired dataset or synthetic paired dataset. However, they often encounter image quality issues and noise labeling problems that can affect algorithm performance. To address these challenges and further improve the quality of underwater image restoration, this work proposes a multi-domain translation method based on domain partitioning. Firstly, this paper proposes an improved confidence estimation algorithm, which uses the number of times a sample is correctly predicted in a continuous period as a confidence estimate. The confidence value estimates are sorted and compared with the real probability to continuously optimize the confidence estimation and improve the classification performance of the algorithm. Secondly, a U-net structure is used to construct the underwater image restoration network, which can learn the relationship between the two domains. The discriminator uses full convolution to improve the performance of the discriminator by outputting the true and false images along with the category to which the true image belongs. Finally, the improved confidence estimation algorithm is combined with the discriminator in the image restoration network to invert the labels for images with low confidence values in the clean domain as images in the degraded domain. The next step of image restoration is then performed based on the new dataset that is divided. In this way, the multi-domain conversion of underwater images is achieved, which helps in the recovery of underwater images. Experimental results show that the proposed method effectively improves the quality and quantity of the images.
7
Zhao, Jie, Yilin Liang, Yudi Fang, Yixuan Weng, Weizhe Ma, Huaixun Zhang e Yiyang Zhang. "Research on the Unit Black-Start Strategy Considering Recovery Path and Start Sequence". Sustainability 14, n. 20 (12 ottobre 2022): 13057. http://dx.doi.org/10.3390/su142013057.
Testo completoAbstract (sommario):
Large-scale power outage events bring serious economic losses to national and social development and cause bad impacts, and the reasonable formulation of a unit black-start strategy is the basis of power outage recovery. Firstly, the Dijkstra shortest path algorithm is used to search for the optimal recovery path of the unit to be started after a major blackout occurs, and secondly, a comprehensive index of the unit start sequence considering the unit characteristics and unit distance is defined to guide the unit start sequence formulation by combining the unit capacity, climbing rate, start power, and other characteristics with the recovery time and capacitance value of the recovery path. Finally, based on the unit start sequence and optimal recovery path, and taking into account the unit start constraints, a complete unit black-start strategy is proposed, and the effectiveness of this strategy is verified by IEEE30 node system simulation. The results show that the proposed unit black-start strategy can reduce the unit recovery time and improve the recovery success rate.
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KOPER, Piotr, Agnieszka PALMOWSKA e Agnieszka MYSZKOWSKA. "RESEARCH OF SINGLE ROOM DECENTRALIZED HEAT RECOVERY UNIT". Architecture, Civil Engineering, Environment 12, n. 4 (2020): 109–14. http://dx.doi.org/10.21307/acee-2019-056.
Testo completo
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Zhang, Wei, Haitian Chen, Tao Chen, Zheping Yan e Hongliang Ren. "Research on Coordinated Robotic Motion Control Based on Fuzzy Decoupling Method in Fluidic Environments". Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/820258.
Testo completoAbstract (sommario):
The underwater recovery of autonomous underwater vehicles (AUV) is a process of 6-DOF motion control, which is related to characteristics with strong nonlinearity and coupling. In the recovery mission, the vehicle requires high level control accuracy. Considering an AUV called BSAV, this paper established a kinetic model to describe the motion of AUV in the horizontal plane, which consisted of nonlinear equations. On the basis of this model, the main coupling variables were analyzed during recovery. Aiming at the strong coupling problem between the heading control and sway motion, we designed a decoupling compensator based on the fuzzy theory and the decoupling theory. We analyzed to the rules of fuzzy compensation, the input and output membership functions of fuzzy compensator, through compose operation and clear operation of fuzzy reasoning, and obtained decoupling compensation quantity. Simulation results show that the fuzzy decoupling controller effectively reduces the overshoot of the system, and improves the control precision. Through the water tank experiments and analysis of experimental data, the effectiveness and feasibility of AUV recovery movement coordinated control based on fuzzy decoupling method are validated successful, and show that the fuzzy decoupling control method has a high practical value in the recovery mission.
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Niemeyer, Frank, Christopher Karberg, Kathrin Baumgarten, Henrich Preuß, Jan Witte, Patrick Bethke, Johann Wollstadt, Konrad Chwelatiuk, Jana Brinkmann e Eileen Trunczik. "MiniLab - Agile underwater platform with integrated sensors for environmental and visual applications". International Hydrographic Review 28 (1 novembre 2022): 212–20. http://dx.doi.org/10.58440/ihr-28-n15.
Testo completoAbstract (sommario):
The Fraunhofer “Smart Ocean Technologies” (SOT) research team extends its range of services towards underwater technology by developing new internal infrastructure. To test sensor technology and materials, empirical underwater data is required to evaluate new technology within realistic conditions. Various external factors like swell, wind, and the underwater environment itself complicate stable framework conditions during the measurements. For this purpose, a test platform called MiniLab was developed which can be extended by modules with respect to common interfaces. It serves as a base frame for internal as well as external projects. The MiniLab consists of an underwater unit and an on-ground unit. Both are connected via a hybrid underwater cable. In addition to the environmental conditions, camera live streams can be transmitted. The MiniLab service platform is currently being used in the Warnow River and in the Digital Ocean Lab (DOL) in the Baltic Sea. However, it is available for observations in other waters (Fraunhofer, 2021a).
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Gong, Haixia, Zhuoran Ping, Tong Zhao, Shuping Hou, Fuqiang Zu, Pengyue Qiu e Jianguo Qin. "Research on Contact Anchoring Theory and Contact Optimization of Underwater Pipeline Recovery Tools". Processes 11, n. 11 (6 novembre 2023): 3166. http://dx.doi.org/10.3390/pr11113166.
Testo completoAbstract (sommario):
Technology for recycling abandoned undersea pipelines is crucial for lowering the cost of installing new submarine pipelines, polluting the ocean less, and improving recycling efficiency. A popular area of study is how to lessen the harm that underwater pipeline recycling instruments do to the inner wall of the pipeline during recycling. In order to recover pipelines, this study examines the anchoring theory and damage process of submerged pipeline recovery equipment. The effect of the contact body’s diameter and radius of the rounded corner on the depth of the pressed-in pipeline and the slip distance is examined using the contact body structure optimization design approach of the underwater pipeline recovery tool, which is based on a multi-objective genetic algorithm. Dynamic simulations of the insertion mechanism as a whole are performed using the Adams simulation program to make sure that the optimized contact body can exert enough contact force on the pipeline’s inner wall. According to the optimization results, the ideal design parameters are D = 57 mm and R = 11.5 mm. While still satisfying the criteria, the improved contact body has higher stability.
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Zhang, Lingli, Chengming Luo, Xiyun Ge, Yuxin Cao, Haobo Zhang e Gaifang Xin. "Three-Dimensional Iterative Enhancement for Coverage Hole Recovery in Underwater Wireless Sensor Networks". Journal of Marine Science and Engineering 11, n. 12 (14 dicembre 2023): 2365. http://dx.doi.org/10.3390/jmse11122365.
Testo completoAbstract (sommario):
The efficient coverage of underwater wireless sensor networks (UWSNs) has become increasingly important because of the scarcity of underwater node resources. Complex underwater environments, water flow forces, and undulating seabed reduce the coverage effect of underwater nodes, even leading to coverage holes in UWSNs. To solve the problems of uneven coverage distribution and coverage holes, a three-dimensional iterative enhancement algorithm is proposed for UWSN coverage hole recovery using intelligent search followed by virtual force. Benefiting from biological heuristic search algorithms, improved particle swarm optimization is applied for node pre-coverage. With the change in iteration times, the adaptive inertia weight, acceleration factor, and node position are constantly updated. To avoid excessive coverage holes caused by search falling into local optimum, underwater nodes are considered as particles in the potential field whose virtual forces are calculated to guide nodes towards higher coverage positions. In addition, based on the optimal node location obtained by the proposed algorithm, the monitoring area is divided based on the clustering idea. The underwater routing protocol DBR based on depth information is subsequently used to optimize node residual energy, and its average is calculated comprehensively and compared with the other three coverage algorithms using the DBR routing protocol. Based on the experimental data, after 100 iterations, the coverage rates for BES, 3D-IVFA, DABVF, and the proposed algorithm are 83.28%, 88.85%, 89.31%, and 91.36%, respectively. Moreover, the proposed algorithm is further verified from the aspects of different node numbers, coverage efficiency, node movement trajectory, coverage hole, and average residual energy of nodes, which provides conditions for resource development and scientific research in marine environments.
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Zhang, Lan, Yu Tao Zhang, Li Quan Wang e Zhi Peng Wang. "Design and Dynamic Characteristics Research of Hydraulic Compensator in Deep Water". Applied Mechanics and Materials 574 (luglio 2014): 603–8. http://dx.doi.org/10.4028/www.scientific.net/amm.574.603.
Testo completoAbstract (sommario):
In this paper, mechanical model of traditional bellow type pressure compensator is established. The analysis of static characteristic shows that compensation volume and variation of pressure compensate margin are limited to each other. As a result, it cannot meet the requirements of marine equipment to the underwater hydraulic power. Therefore, a new type of pressure compensation unit is developed, it has advantages of big volume compensation and almost constant pressure compensate margin, it solves the core technical problem of deep-water balancing hydraulic power. The simulation results show that this new type of pressure compensator can satisfy the design requirements and improve the working depth of underwater hydraulic systems sharply.
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Li, Yong An, Ting Ting Wang, Xue Lai Liu e Teng Xing. "Thermal Performance Research of Thermal Recovery Unit for Air-Conditioning Systerm". Advanced Materials Research 243-249 (maggio 2011): 4965–68. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.4965.
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This document established a three-dimensional laminar mathematical and physical model which describes heat transfer, mass transfer coupling process in wet thermal recovery unit for air-conditioning systerms, based on Computational Fluid Dynamics (CFD) simulations. In addition, the research discussed the distributions of pressure, temperature, concentration and other parameters in the air channels. The heat transfer performance was analyzed by enthalpy efficiency. The results showed that the structural parameters of wet thermal recovery unit for air-conditioning systerm played important influence in the heat transfer performance and flow drag performance. The research set a foundation for the optimal design of wet thermal recovery unit for air-conditioning systerm.
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Lee, Chong Hyun, Kibae Lee e Guhn Hyeok Ko. "An underwater sound event detection algorithm based on Temporal Graph Convolutional Network". Journal of the Acoustical Society of America 154, n. 4_supplement (1 ottobre 2023): A78. http://dx.doi.org/10.1121/10.0022856.
Testo completoAbstract (sommario):
Accurate underwater sound event detection (SED) and real-time underwater situation awareness plays an important role in intelligent sonar system. However, little research on underwater SED has been done because underwater acoustics have very complex and dynamic spectral and temporal characteristics which make underwater SED difficult to solve. The goal of SED is to recognize type and time of the input audio signal and most of SED research have been focused on airborne sound so far. To address underwater SED problem, we adopt temporal graph convolutional network (T-GCN), which is originally designed for traffic prediction and is composed of GCN and gated recurrent unit (GRU) To capture spectral and temporal information simultaneously, the GCN is used to learn topological structures to capture spectral correlation and the GRU is used to learn changes of input sound to capture temporal correlation. The proposed model utilizes sound spectrogram and its annotation with temporal information as input and then the GCN and GRU of the model is employed to solve underwater SED problem. Experiments using urban SED dataset and underwater sound dataset, demonstrate that our proposed model expresses connection of spectral and temporal information effectively and shows reliable underwater SED performance accordingly.
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Huang, Jin, Bingquan Zhang, Weiqiu Huang, Zhiping Zhu, Feng Tao, Quanzhan Wang, Zhaohui Huang, Jianjun Zhu, Xiaoxin Zhang e Lin Zhang. "Research on the general technical standards of the gasoline vapor recovery unit set". E3S Web of Conferences 118 (2019): 02017. http://dx.doi.org/10.1051/e3sconf/201911802017.
Testo completoAbstract (sommario):
Along with the increasingly strict environmental regulation and the willingness to rapidly promote gasoline vapor recovery management, the development of technology and equipment for gasoline vapor recovery industry grows faster, and the demand for relevant technical standards is also growing. Based on the domestic and foreign development situation of gasoline vapor recovery technology and standard, this article analyzes necessity and urgency of the general technical standards for development of China’s vapor recovery unit, and then it introduces the main technical content of the national standard GB/T 35579-2017 General Specifications of Gasoline Vapor Recovery Unit”, and provides some advices to refine the related technical standards.
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Meng, Jing, Zhi Xin Chen, Tao Jiang e Zhi Qiang Xu. "Controllable of Underwater Towing Tension Passive Compensation Device Design Research". Applied Mechanics and Materials 721 (dicembre 2014): 104–8. http://dx.doi.org/10.4028/www.scientific.net/amm.721.104.
Testo completoAbstract (sommario):
In order to solve the process of fishing, hull has significant heave motion under the influence of marine environment, that caused towing tension instability and fishing low efficiency problems, proposed and developed based on the hydraulic cylinder and the accumulator between the energy conversion and PLC control of towing tension range controllable passive compensation device. According to its working principle, the passive compensation device of compensation system and control system was designed, using the hull heave motion as the control energy, hydraulic cylinder and accumulator combination as a compensation system, selects PLC224CPU and M235 expansion module as the control unit. Finally, the towing tension range change of compensation has carried on the simulation analysis, the simulation results show that the passive compensation device which can realize the adjustment and control of drag tension range, achieves the expected control effect.
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Radeta, Marko, Claudio Rodrigues, Francisco Silva, Pedro Abreu, João Pestana, Ngoc Thi Nguyen, Agustin Zuniga, Huber Flores e Petteri Nurmi. "Lost in the Deep?" Proceedings of the ACM on Interactive, Mobile, Wearable and Ubiquitous Technologies 7, n. 2 (12 giugno 2023): 1–27. http://dx.doi.org/10.1145/3596245.
Testo completoAbstract (sommario):
Computing research is increasingly addressing underwater environments and examining how computing can support diving and other activities. Unlike on land, where well-established positioning methods are widely available, underwater environments lack a common positioning mechanism, which is a prerequisite for many applications. Dead reckoning, the use of angle and distance estimates to track position changes from a known point of origin, is a promising candidate for underwater positioning as it does not rely on wireless signals (which decay rapidly in underwater environments) and as there is a wide range of literature and algorithms freely available. Yet, currently it is unclear whether the existing techniques can be adopted in underwater environments or whether the differences in medium and environment affect the performance of the dead reckoning techniques. We contribute by evaluating and systematically analyzing the performance and trade-offs associated with dead reckoning techniques in underwater environments. We present AEOLUS, a prototype unit comprising of a low-cost microcontroller and inertial measurement unit, to perform experiments on the ground and in underwater environments to assess how well the performance of different techniques translates from ground-based use cases to underwater environments. We benchmark 15 different algorithms and compare their performance in such environments to identify common patterns and dissimilarities, and identify root causes for these differences. The results show that displacement and turn errors can be estimated to within 5% error but that the best performing methods vary between land and underwater environments. We also show that the performance depends on the shape of the motion patterns with some algorithms performing better for hard turns whereas others perform better for gradual, more continuous turns.
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Andrews, Anthony P., e Robert Corletta. "A Brief History of Underwater Archaeology in the Maya Area". Ancient Mesoamerica 6 (1995): 101–17. http://dx.doi.org/10.1017/s0956536100002121.
Testo completoAbstract (sommario):
AbstractUnderwater archaeology in the Maya area during the twentieth century has gradually evolved from a avocational activity whose primary focus was on the recovery of artifacts to a subdiscipline with more focused professional concerns. The present synthesis outlines the history of underwater research throughout the Maya area, including projects at pre-Hispanic sites in the lowlands and highlands, as well as the exploration of offshore historic wrecks. It concludes with a brief assessment of the current state of this research.
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Wei, Jie, e Shaohua Li. "Application of Convolutional Neural Network in Quantifying Reservoir Channel Characteristics". Applied Sciences 14, n. 6 (7 marzo 2024): 2241. http://dx.doi.org/10.3390/app14062241.
Testo completoAbstract (sommario):
After many years of exploitation in the petroleum field, most of the oil fields are in advanced stages of development, with a strong non-homogeneity of the reservoir, more residual oil, and low recovery efficiency. Therefore, research on various methods has been carried out by scholars to improve the rate of recovery and to understand the distribution pattern of residual oil in reservoirs. Among the whole clastic reservoirs, fluvial reservoirs occupy a large proportion, so fluvial reservoirs will be the priority for future reservoir research in China. The key to the fine characterization of fluvial-phase reservoirs is to able to reproduce the continuous curvature of the channel, and one important parameter is the width of the channel. The width of the channel sand body is one of the key factors in designing well programs, and accurately identifying the channel boundary is the key to identifying a single channel. Traditional research methods cannot accurately characterize the continuous bending and oscillating morphology of underwater diversion channels, and it is not easy to quantitatively characterize the spatial structure. Therefore, in this paper, a deep learning method is applied to quantitatively identify the width of a single channel within an underwater diversion channel at the delta front edge. Based on the sedimentary background of the block and modern depositional studies, we established candidate models for underwater diversion channels with channel widths of 100, 130, 160, 190, 220, and 250 m based on target simulation and human–computer interactions. The results show that when the width of the underwater diversion channel is 160 m, it has the highest matching rate with the conditional data and corresponds to the actual situation. Therefore, it can be determined that it is the common width of underwater diversion channel in the study area. And it is shown that the method can accurately identify the width of underwater diversion channels, and the results provide a basis for reservoir fine characterization studies.
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Bondyrev, V. E., S. I. Knyazev, V. I. Korolev e S. F. Jatsun. "Small-size Unmanned Control Algorithm of an Underwater Complex". Proceedings of the Southwest State University 24, n. 4 (4 febbraio 2021): 166–79. http://dx.doi.org/10.21869/2223-1560-2020-24-4-166-179.
Testo completoAbstract (sommario):
Purpose of research: The creation of water bodies monitoring systems makes it possible to evaluate environmental situation in various points of monitoring area quickly. One of the main stages of water quality research is sampling, which is currently carried out at stationary posts, which makes it impossible to ensure operational control in various areas of an observation site. The problem can be solved by using mobile robotic platforms. The purpose of this study is to create mathematical model and algorithm for controlling autonomous movement of an underwater robotic device for collecting water samples in a reservoir. Methods. The following problems were solved for this purpose: the structure of the device was developed, which consists of a power frame unit, units of screw electric drives, units of depth and direction rudders. On-board power supply unit, sensor unit providing interaction of underwater vehicle with environment were also developed. Control tasks are formulated. A scheme of device movement in a reservoir has been developed for this purpose. Results. Modular method of trajectory planning is proposed. It is based on a single motion cycle concept, which consists of 2 turns and 2 straight-line stages of 2R2P. A model of control algorithm is also proposed and reactions of apparatus to external disturbances are studied. General dynamics theorems, method of algorithm synthesizing according to inverse dynamics problem were applied when solving problems. Conclusion: As a result of conducted studies, the system response to disturbances acting in longitudinal direction is described, disturbance diagrams are also described, random type with normal distribution law and mass center deviation s from the given position are given.
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Ren, An Min, e Lin He. "Research on the Performance of Suppressing Interference Using Double Stages Wiener Filter in Underwater Noise Measurement". Applied Mechanics and Materials 530-531 (febbraio 2014): 544–49. http://dx.doi.org/10.4028/www.scientific.net/amm.530-531.544.
Testo completoAbstract (sommario):
Measured data of hydrophone array could be interfered by underwater noise,so its essential to enhance the performance of suppressing interference for adaptive array processing. How to improve the performance of Double Stages Wiener Filter was discussed based on configuration principles. The influences of interference angle, array unit number and interference-to-noise ratio (INR) to suppressing interference have been analyzed through principle analysis and simulation experiments under different circumstances, including single or multiple disturb signals. Experiments show that the performance of suppressing interference depends on interference angle and INR more and array unit sum a little.
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Ekkel, T., J. Schmik, T. Luhmann e H. Hastedt. "PRECISE LASER-BASED OPTICAL 3D MEASUREMENT OF WELDING SEAMS UNDER WATER". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-5/W5 (9 aprile 2015): 117–22. http://dx.doi.org/10.5194/isprsarchives-xl-5-w5-117-2015.
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This paper deals with the development of a measuring procedure and an experimental set-up (stereo camera system in combination with a projecting line laser and a positioning unit) which are intended to detect the surface topography, particularly of welds, with high accuracy in underwater environments. The system concept makes provision for the fact that the device can be positioned in space and manipulated by hand. The development, optimization and testing of the system components for surface measurements as well as calibration and accuracy evaluations are the main objectives within this research project. Testing procedures and probes are constructed and evaluated to verify the results. First results will be shown, where the test objects are underwater. The development considers conditions for a future adaption to underwater use.
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Che, Sai, Zhongguo Li, Zhou Shi, Miaowei Gao e Hongchuan Tang. "Research on an underwater image segmentation algorithm based on YOLOv8". Journal of Physics: Conference Series 2644, n. 1 (1 novembre 2023): 012013. http://dx.doi.org/10.1088/1742-6596/2644/1/012013.
Testo completoAbstract (sommario):
Abstract Underwater image segmentation faces complex problems such as target type, number, scale, and environmental interference. The traditional segmentation method relies on much manual annotation and expertise, extracts only the surface information of the image, and has low segmentation accuracy and efficiency, so the image segmentation method based on deep learning is chosen. Deep learning algorithms are used on top of the YOLOv8, and the adaptive self-supervised learning (Convnext V2) module, the lightweight network (Slim Neck), and the dynamic sparse attention mechanism (bilevel routing attention, Biformer) are added, which improves the YOLOv8 algorithm for single-stage instance segmentation of different underwater targets. The Convnext V2 module introduces the global response normalization (GRN) unit, which enhances the feature competition and reduces the model computation. A slim neck network is designed, which achieves a double improvement in model inference speed and accuracy by the operation of dense convolution in the lightweight convolution (GSConv) module and the design of a cross-level network structure (VoV-GSCSP). The introduction of Biformer’s dynamic sparse attention mechanism achieves more flexible computational allocation and content awareness. Comparison experiments show that the improved algorithm dramatically increases the segmentation speed while improving the segmentation accuracy. On the dual-target dataset, the mAP is improved by 3.5% from 0.753 to 0.779, and the FPS is improved by 86% from 63 to 117. The experiments validate that the improved algorithm can be used for the segmentation of different underwater images.
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Sari, Dewi Mutiara, Bayu Sandi Marta, Muhammad Amin A e Haryo Dwito Armono. "The Analysis of Underwater Imagery System for Armor Unit Monitoring Application". International Journal of Artificial Intelligence & Robotics (IJAIR) 5, n. 1 (29 aprile 2023): 1–12. http://dx.doi.org/10.25139/ijair.v5i1.5918.
Testo completoAbstract (sommario):
The placement of armor units for breakwaters in Indonesia is still done manually, which depends on divers in each placement of the armor unit. The use of divers is less effective due to limited communication between divers and excavator operators, making divers in the water take a long time. This makes the diver's job risky and expensive. This research presents a vision system to reduce the diver's role in adjusting the position of each armor unit. This vision system is built with two cameras connected to a mini-computer. This system has an image improvement process by comparing three methods. The results obtained are an average frame per second is 20.71 without applying the method, 0.45 fps for using the multi-scale retinex with color restoration method, 16.75 fps for applying the Contrast Limited Adaptive Histogram Equalization method, 16.17 fps for applying the Histogram Equalization method. The image quality evaluation uses the underwater color quality evaluation with 48 data points. The method that has experienced the most improvement in image quality is multi-scale retinex with color restoration. Forty data have improved image quality with an average of 14,131, or 83.33%. The number of images that experienced the highest image quality improvement was using the multi-scale retinex with color restoration method. Meanwhile, for image quality analysis based on Underwater Image Quality Measures, out of a total of 48 images, the method with the highest value for image quality is the contrast limited adaptive histogram equalization method. 100% of images have the highest image matrix value with an average value is 33.014.
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Wei, Jiangwei, Fawang Li, Shikuo Zhang, Hanlie Cheng, Qiang Qin e David Cadasse. "Characteristics of Sedimentary Microfacies of Late Triassic Yanchang Formation in North-Central Ordos Basin". Journal of Chemistry 2022 (22 settembre 2022): 1–10. http://dx.doi.org/10.1155/2022/1513503.
Testo completoAbstract (sommario):
Sedimentary microfacies refer to the smallest unit with unique rock structure, structure, thickness, rhythm, and other sedimentary characteristics and certain plane configuration rules in the subfacies zone. Sedimentary microfacies research is the most basic sedimentary unit formed in the same or basically the same sedimentary background. Sedimentary microfacies marks are the key to the division of sedimentary microfacies. If we cannot find effective marks, we cannot correctly divide sedimentary microfacies. These marks are mainly obtained from detailed observation of cores. On the premise of fully understanding the regional tectonic background of the study area, the sedimentary facies and sedimentary subfacies types within the oilfield control range are determined. In this study, the single-well facies and profile facies are deeply analyzed by observing and describing the cores of Chang 2 reservoir group in Huangjialing, north-central Ordos Basin, and comprehensively utilizing the data of coring, logging, and core analysis and testing. The basic sedimentary characteristics, types of sedimentary facies and microfacies, and plane distribution of sedimentary facies in this area are systematically studied. The results show that there are mainly three microfacies: underwater distributary channel, natural dike, and distributary bay. Among them, the microfacies of the underwater natural dike are relatively undeveloped, mainly the microfacies of underwater distributary channel and underwater distributary bay. These studies have important practical significance for the later exploration of oil and gas in Ordos Basin.
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Wang, Tong, Zihao You, Wei Song e Shiqiang Zhu. "Dynamic Analysis of an Underwater Cable-Driven Manipulator with a Fluid-Power Buoyancy Regulation System". Micromachines 11, n. 12 (26 novembre 2020): 1042. http://dx.doi.org/10.3390/mi11121042.
Testo completoAbstract (sommario):
This article presents an underwater cable-driven manipulator (UCDM) with a buoyancy regulation system (BRS), which is controlled by a fluid-power system. The manipulator consists of five sections, and each section is embedded with a buoyancy adjustment unit. By regulating buoyancy at each section, the static and dynamic states of the manipulator will be changed, promising a new operating mode of an underwater manipulator driven by buoyancy. In this article, a dynamic model of the manipulator is established by the Newton-Euler equation, considering cable tension, inter-joint force, buoyancy, water resistance and other variables. With a numerical method, the dynamic model is solved and the values of cable tension are obtained, which are used to evaluate the buoyancy-driven operating mode of underwater manipulator. This research will be useful for manipulator operating in fluid environments, such as underwater manipulator in the ocean, micro-manipulator in a blood vessel, and so on.
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Mei, Xinkui, Xiufen Ye, Xiaofeng Zhang, Yusong Liu, Junting Wang, Jun Hou e Xuli Wang. "UIR-Net: A Simple and Effective Baseline for Underwater Image Restoration and Enhancement". Remote Sensing 15, n. 1 (22 dicembre 2022): 39. http://dx.doi.org/10.3390/rs15010039.
Testo completoAbstract (sommario):
Because of the unique physical and chemical properties of water, obtaining high-quality underwater images directly is not an easy thing. Hence, recovery and enhancement are indispensable steps in underwater image processing and have therefore become research hotspots. Nevertheless, existing image-processing methods generally have high complexity and are difficult to deploy on underwater platforms with limited computing resources. To tackle this issue, this paper proposes a simple and effective baseline named UIR-Net that can recover and enhance underwater images simultaneously. This network uses a channel residual prior to extract the channel of the image to be recovered as a prior, combined with a gradient strategy to reduce parameters and training time to make the operation more lightweight. This method can improve the color performance while maintaining the style and spatial texture of the contents. Through experiments on three datasets (MSRB, MSIRB and UIEBD-Snow), we confirm that UIR-Net can recover clear underwater images from original images with large particle impurities and ocean light spots. Compared to other state-of-the-art methods, UIR-Net can recover underwater images at a similar or higher quality with a significantly lower number of parameters, which is valuable in real-world applications.
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Solon, Kimberly, Eveline I. P. Volcke, Mathieu Spérandio e Mark C. M. van Loosdrecht. "Resource recovery and wastewater treatment modelling". Environmental Science: Water Research & Technology 5, n. 4 (2019): 631–42. http://dx.doi.org/10.1039/c8ew00765a.
Testo completoAbstract (sommario):
This paper discusses the extent to which new unit processes applied for resource recovery can be modelled with conventional ASMs, the additional modelling challenges being faced, while providing recommendations on how to address current modelling research gaps.
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Barclay, David R., e Najeem Shajahan. "Energy partitioning of the underwater soundscape". Journal of the Acoustical Society of America 154, n. 4_supplement (1 ottobre 2023): A219. http://dx.doi.org/10.1121/10.0023336.
Testo completoAbstract (sommario):
A four-element three-dimensional hydrophone array has been deployed on the Strait of Georgia node of the Victoria Experimental Network Under the Sea (VENUS) since March 2020. To the present, continuous pressure time series data from the four sensors has been streamed ashore and made available by Ocean Networks Canada. A technique for classifying and partitioning ambient noise using the three-dimensional noise coherence function is applied to the recordings. The noise coherence (directionality) due to wind generated surface noise and individual ships is analytically modelled using measured environmental inputs such as the time varying sound speed profile and sediment properties from the measurement site and compared with the observation. The theoretical coherence curve is computed by mixing the contributing sources until a best-fit is found. Since the wind generated surface noise coherence is stable and independent of the source effective sound power per unit area, the contribution of ship noise to the soundscape can be exactly determined. Applying this algorithm to the long-term data set allows the relative contribution of ship noise to the soundscape in the region to summarized succinctly. [Research supported by ONR.]
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Gambin, Timmy, Maja Sausmekat e Darko Kovacevic. "The Innovative and State of the Art Public Access Management of Malta’s Underwater Cultural Heritage". Heritage 4, n. 4 (13 ottobre 2021): 3365–81. http://dx.doi.org/10.3390/heritage4040187.
Testo completoAbstract (sommario):
The obligation to preserve underwater cultural heritage is a core principle of the UNESCO Convention on the Protection of the Underwater Cultural Heritage. A key element of this obligation is a balance of scientific research, protection, and the promotion of responsible access to underwater cultural heritage sites. Such a balance requires the setting up of a network of communication between the tourism and heritage sectors on the one hand and the maritime and diving communities on the other hand. A variety of approaches have been developed to promote responsible access to underwater cultural heritage sites, and since the vast majority of the public does not dive, this also includes the development of virtual access. In Malta, maritime archaeology can be traced to humble and sporadic beginnings in the 1950s. The following decades brought a growing interest in diving activities and a rising number of diving schools and clubs. Whilst Malta has today established itself as a diving tourism destination, responsible access to underwater cultural heritage sites was not always entrenched in dive operations or institutionally recognized. The protection and management of underwater cultural heritage has recently been firmly established within Heritage Malta, the national agency for museums, conservations, and cultural heritage. This paper is intended to outline the trajectory of Malta’s underwater cultural heritage management and to present the innovative and state of the art public access system that is managed by the Underwater Cultural Heritage Unit within Heritage Malta.
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Luo, Peng, Yuanjie Song, Xiaoyang Xu, Chen Wang, Shaowei Zhang, Yeqiang Shu, Yonggui Ma, Chong Shen e Chuan Tian. "Efficient Underwater Sensor Data Recovery Method for Real-Time Communication Subsurface Mooring System". Journal of Marine Science and Engineering 10, n. 10 (14 ottobre 2022): 1491. http://dx.doi.org/10.3390/jmse10101491.
Testo completoAbstract (sommario):
Marine submerged buoys can effectively obtain various parameters of seawater, which plays an important role in the research of marine physical phenomena, marine environmental changes, and climate change. However, traditional self-contained submerged buoys usually work underwater at a depth of about 100 m, and the observation data cannot be obtained before their recovery, which cannot satisfy the needs of real-time data acquisition for marine scientific research. To solve this problem, this paper proposes a real-time communication subsurface mooring system that consists of a satellite communication buoy (SCB), conductivity–temperature–depth sensors (CTD), and an inductive coupling mooring cable. The underwater inductive coupling link collects the data from the underwater sensors and transmit it to the SCB. Then, the data will be transmitted to the station receiver via satellite communication module integrated into the SCB. In order to ensure a high success rate of data recovery, the stress analysis and hydrodynamic simulation of the SCB were carried out in this paper. The results show that the SCB maintained a relatively stable attitude in the 3–4 sea state. The attitude data obtained from the subsequent sea trial was consistent with the simulation results, and the success rate of satellite communication during this period was more than 95%. In this paper, a modular embedded hardware circuit was designed to meet the functional requirements of the subsurface mooring system. An efficient data recovery strategy was also developed, which ensured that the average power consumption of the system was low and the success rate of data recovery is not less than 90% when operating in the severe sea state for a long time. The system underwent sea trials in the South China Sea for more than 3 months from the end of 2021 to the beginning of 2022. It transmitted more than 2034 sets of seawater profile temperature, salinity, and depth data in real-time, with a success rate of over 91% of the total sample data. The CTD data returned in real-time from our system is consistent with the data of the HYCOM and World Ocean Atlas (WOA), and a cyclonic mesoscale eddy was detected in the operation area.
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Milto, Olga, e Nikolay Amosov. "Condensing heat recovery unit use for operation efficiency increase of boiler units". Energy Systems 5, n. 1 (25 novembre 2020): 59–66. http://dx.doi.org/10.34031/es.2020.1.007.
Testo completoAbstract (sommario):
The article is dedicated to the research of operation efficiency increase of the boiler unit TGMP-344A by introducing the utilization unit into the technological scheme. The article considers the possibility of closed type condensing heat recovery unit use and utilization of an exhaust gas potential for raw water heating before a water treatment system at CHP.
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Sutrisno, Avando Bastari e Okol Sri Suharyo. "Analysis of underwater welding in Indonesian warship using low hydrogen electrodes". Global Journal of Engineering and Technology Advances 7, n. 3 (30 giugno 2021): 083–94. http://dx.doi.org/10.30574/gjeta.2021.7.3.0081.
Testo completoAbstract (sommario):
As a security unit for the territorial waters of the Republic of Indonesia, the Indonesian Navy is required for combat readiness to carry out security operations quickly and precisely. It is very important to the readiness of the Indonesian Navy's ABK Soldiers and the Republic of Indonesia's defense equipment for warships in carrying out security activities in the territorial waters of the Republic of Indonesia. This study discusses underwater wet welding in anticipating an emergency if the ship's hull is hit by a collision so that the hull has cracks or holes. This research method uses AH36 steel plate metal. Then, underwater wet welding was carried out on the AH36 plate using a low hydrogen type electrode. Before welding, the electrodes were subjected to a drying process to a temperature of 900C. Wet welding underwater is carried out at a depth of 5 meters in seawater. The results of underwater wet welding are NDT testing; penetrant test, radiography test, then also DT test; hardness test, tensile test, and test according to ASTM standard. Analysis of underwater wet welding results compared to atmospheric welding results as quality control, so that the percentage difference in mechanical properties can be known. The interesting thing from welding AH36 steel plate with underwater wet welding and applying low hydrogen electrodes is the minimal level of weld porosity defects in the welding results. So that the low hydrogen electrode can be used in welding AH36 steel plate in underwater welding applications.
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Li, Yang, e Xiu Juan Liang. "Experimental Study on Energy Saving between Heat Pump Unit of Heat Recovery Fresh Air and Heat Pipe Heat Pump Low Temperature Heat Recovery Unit in the Cold and Severe Cold Regions". Applied Mechanics and Materials 535 (febbraio 2014): 37–41. http://dx.doi.org/10.4028/www.scientific.net/amm.535.37.
Testo completoAbstract (sommario):
In the cold and severe cold regions of our country, the average temperature in winter outdoor usually below -20°C. Air conditioning units was limited and damaged when it running under such conditions. In order to solve the the problems pointed out previously, the paper put forward solutions of the fresh air handling units in combination with heat pump unit of heat recovery fresh air and heat pipe heat pump low temperature heat recovery unit. Comparison energy-saving and recovery period of the two method through experimental research.
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Li, Yon Gan, Hua Min Chen, Xue Lai Liu e Wei Tao Luan. "Simulation on Resistance Characteristics of Air-to-Air Energy Recovery Equipment". Advanced Materials Research 243-249 (maggio 2011): 4975–78. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.4975.
Testo completoAbstract (sommario):
Through carried out computer simulation analysis on air-to-air energy recovery equipment，the analysis research mainly aims at pressure drop characteristics among the factors which influence the core of the heat exchanger，the results show that：as the plate spacing, plate width, plate height, as well as changes in a secondary air inlet velocity core，all of them will have different effects on the air-to-air energy recovery unit of the resistance loss, which is useful to air-to-air energy recovery unit to optimize the design.
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Veitová-Šilarová, L., e M. Valenta. "Evaluation of Dramatherapy at the Addiction Recovery Unit by Alumni I". Клиническая и специальная психология 7, n. 2 (2018): 124–34. http://dx.doi.org/10.17759/cpse.2018070209.
Testo completoAbstract (sommario):
This is the first part of an article dealing with an evaluation of the dramatherapy process. The first part introduces a long-term research project assessing the dramatherapy process at the 17B Addiction Recovery Unit of the Kroměříž Psychiatric Hospital. Building on therapeutic community principles, the treatment provided at the Unit is a medium-term addiction recovery programme (4 to 6 months). The part of the research discussed in this paper is focused on an evaluation of the dramatherapy process as seen by alumni (abstainers), who received therapy at the Unit between February 2014 and June 2017. The data was collected from semi-structured focus groups organized as part of alumni meetings at the Unit. The findings of the focus group analysis will be presented in the second part of the article. They are designed to describe the specific benefits of dramatherapy intervention in the treatment of addictions and the potential of the transfer of experience, obtained in dramatherapy interventions, for the abstainer's daily life from the perspective of alumni.
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Mateen, Abdul, Muhammad Awais, Nadeem Javaid, Farruh Ishmanov, Muhammad Afzal e Saqib Kazmi. "Geographic and Opportunistic Recovery with Depth and Power Transmission Adjustment for Energy-Efficiency and Void Hole Alleviation in UWSNs". Sensors 19, n. 3 (9 febbraio 2019): 709. http://dx.doi.org/10.3390/s19030709.
Testo completoAbstract (sommario):
Underwater Wireless Sensor Networks (UWSNs) are promising and emerging frameworks having a wide range of applications. The underwater sensor deployment is beneficial; however, some factors limit the performance of the network, i.e., less reliability, high end-to-end delay and maximum energy dissipation. The provisioning of the aforementioned factors has become a challenging task for the research community. In UWSNs, battery consumption is inevitable and has a direct impact on the performance of the network. Most of the time energy dissipates due to the creation of void holes and imbalanced network deployment. In this work, two routing protocols are proposed to avoid the void hole and extra energy dissipation problems which, due to which lifespan of the network increases. To show the efficacy of the proposed routing schemes, they are compared with the state of the art protocols. Simulation results show that the proposed schemes outperform the counterparts.
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Hudaliev, Yu M., e N. D. Shishkin. "The heat exchange research in the heat recovery unit with finned heat pipes". Journal of Physics: Conference Series 1652 (ottobre 2020): 012026. http://dx.doi.org/10.1088/1742-6596/1652/1/012026.
Testo completo
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Song, Ruiping, Xiao Feng, Junfeng Wang, Haixin Sun, Mingzhang Zhou e Hamada Esmaiel. "Underwater Acoustic Nonlinear Blind Ship Noise Separation Using Recurrent Attention Neural Networks". Remote Sensing 16, n. 4 (9 febbraio 2024): 653. http://dx.doi.org/10.3390/rs16040653.
Testo completoAbstract (sommario):
Ship-radiated noise is the main basis for ship detection in underwater acoustic environments. Due to the increasing human activity in the ocean, the captured ship noise is usually mixed with or covered by other signals or noise. On the other hand, due to the softening effect of bubbles in the water generated by ships, ship noise undergoes non-negligible nonlinear distortion. To mitigate the nonlinear distortion and separate the target ship noise, blind source separation (BSS) becomes a promising solution. However, underwater acoustic nonlinear models are seldom used in research for nonlinear BSS. This paper is based on the hypothesis that the recovery and separation accuracy can be improved by considering this nonlinear effect in the underwater environment. The purpose of this research is to explore and discover a method with the above advantages. In this paper, a model is used in underwater BSS to describe the nonlinear impact of the softening effect of bubbles on ship noise. To separate the target ship-radiated noise from the nonlinear mixtures, an end-to-end network combining an attention mechanism and bidirectional long short-term memory (Bi-LSTM) recurrent neural network is proposed. Ship noise from the database ShipsEar and line spectrum signals are used in the simulation. The simulation results show that, compared with several recent neural networks used for linear and nonlinear BSS, the proposed scheme has an advantage in terms of the mean square error, correlation coefficient and signal-to-distortion ratio.
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Ward, Louise, e Karleen Gwinner. "Have you got what it takes? Nursing in a Psychiatric Intensive Care Unit". Journal of Mental Health Training, Education and Practice 10, n. 2 (11 maggio 2015): 101–16. http://dx.doi.org/10.1108/jmhtep-08-2014-0021.
Testo completoAbstract (sommario):
Purpose – A Psychiatric Intensive Care Unit (PICU) and or High Dependency Unit (HDU) is a locked, intensive treatment facility available to people experiencing acute psychiatric distress. For many people who access public mental health services in Australia, the PICU/HDU is the primary point of admission, and should represent and facilitate timely assessment and an optimum treatment plan under a recovery framework. Nurses are the largest health discipline working in this specialty area of care. The paper aims to discuss these issues. Design/methodology/approach – A qualitative study aimed to investigate the skills, experience, and practice, of nurses working in the PICU/HDU in relation to a recovery model of care. Identifying how nurses provide care in the PICU/HDU will inform a clinical practice guideline to further support this specialty area of care. Four focus groups were facilitated with 52 registered nurses attending. Findings – The nurse participants identified specific skills under four distinct themes; Storytelling, Treatment and recovery, Taking responsibility, and Safeguarding. The skills highlight the expertise and clinical standard required to support a recovery model of care in the PICU. Research limitations/implications – The research findings highlight urgency for a National PICU/HDU clinical practice guideline. Practical implications – A PICU/HDU practice guideline will promote the standard of nursing care required in the PICU/HDU. The PICU/HDU needs to be recognised as a patient centred, therapeutic opportunity as opposed to a restrictive and custodial clinical area. Social implications – Providing transparency of practice in the PICU/HDU and educating nurses to this specialty area of care will improve client outcome and recovery. Originality/value – Very few studies have explored the skills, experience, and practice, of nurses working in the PICU/HDU in relation to a recovery model of care. A dearth of research exists on what is required to work in this specialty area of care.
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Ruan, Dongrui, Jiawang Chen, Jiqing Jiang, Xiaoqing Peng, Peng Zhou e Yue Huang. "Research on Sampling System for Abyssal Sediment Based on Image Recognition Technology". Marine Technology Society Journal 56, n. 4 (23 agosto 2022): 21–29. http://dx.doi.org/10.4031/mtsj.56.4.9.
Testo completoAbstract (sommario):
Abstract The pressure-holding sampling technology for deep-sea sediments has been identified as a prerequisite for studying the sedimentary environment with respect to the mechanical and biological characteristics of sediments. Thus, in this study, we designed a set of abyssal sediment sampling systems based on image recognition technology. First, a system camera was used to obtain the movement trajectory of the sampling cone in the laboratory simulation scene. After collecting the data of the image including the sampler, we preprocessed the data using an underwater image restoration method based on the dark channel prior. An image recognition unit was used to verify that the position of the sampling cone meets the requirement. The main control unit controlled the actuator of the sampling device to accurately control the position of the sampling cone. Furthermore, we used the Mask R-convolutional neural network architecture to build the network framework for controlling the expansion and braking of the sampler. The experimental results showed that the system achieved a very high detection accuracy for the position of the sampling cone.
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Tkachenko, Mykola, Oleg Skorokhvatov, Alexey Kovalchuk e Alexey Malishkin. "SMALL ARMS FOR UNDERWATER SHOOTING". Collection of scientific works of Odesa Military Academy, n. 15 (30 settembre 2021): 128–33. http://dx.doi.org/10.37129/2313-7509.2021.15.128-133.
Testo completoAbstract (sommario):
The article analyses the possible risks that may arise during the use of small arms for underwater shooting when combat swimmers are performing combat missions. The shortcomings that affect the accuracy and range of underwater and airborne special weapons are identified, which will reduce the likelihood of abnormal situations that can lead to tragic consequences and failure to perform the assigned combat mission. Ways to develop new small arms for use under water and on land have been identified. Extensive research into the development of underwater small arms was launched after World War II. The result is a variety of systems: rubber, spring, pneumatic, fire. Based on a brief analysis of the main characteristics of the weapon, which uses the energy of a compressed spring, the energy of a stretched rubber bundle or compressed air to throw the defeating element, it is possible to conclude that these types of underwater weapons are large, large weight and low rate of fire. They are characterized by a small power of the shot, which provides the actual movement of the bullet (harpoon, needle) at a distance of 5-10 m and a low firing density. Fulfillment of these requirements (the effect of the bullet on the target, the density and accuracy of firing, the distance of effective firing), as shown by the calculations and results of experiments, can be ensured only through the use of firearms (in which to throw the element using powder energy). Today, the armies of developed countries have a number of similar systems. Among the most significant developments is the BUW-2 submarine pistol, developed in 1971 in Germany by AJW. This is a multi-charge semi-automatic launcher that fires, active-jet bullets with hydrodynamic stabilization. The cartridges are located in 4 barrels, which create a disposable unit. In terms of firing distance, the pistol has an advantage over most samples of weapons used for spearfishing. Keywords: pistol, assault rifle, accuracy, APS, SPP.
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T, Buddesab, Thriveni J e Venugopal K R. "Trust model genetic node recovery based on cloud theory for underwater acoustic sensor network". International Journal of Electrical and Computer Engineering (IJECE) 9, n. 5 (1 ottobre 2019): 3759. http://dx.doi.org/10.11591/ijece.v9i5.pp3759-3771.
Testo completoAbstract (sommario):
<span>Underwater Acoustic Sensor Networks [UASNs] are becoming a very growing research topic in the field of WSNs. UASNs are harmful by many attacks such as Jamming attacks at the physical layer, Collision attacks at the data link layer and Dos attacks at the network layer. UASNs has a unique characteristic such as unreliable communication, mobility, and computation of underwater sensor network. Because of this the traditional security mechanism, e.g. cryptographic, encryption, authorization and authentications are not suitable for UASNs. Many trust mechanisms of TWSNs [Terrestrial Wireless Sensor Networks] had proposed to UASNs and failed to provide security for UASNs environment, due to dynamic network structure and weak link connection between sensors. In this paper, a novel Trust Model Genetic Algorithm based on Cloud Theory [TMC] for UASNs has been proposed. The TMC-GA suggested a genetic node recovery algorithm to improve the TMC network in terms of better network lifetime, residual energy and total energy consumption. Also ensures that sensor nodes are participating in the rerouting in the routing discovery and performs well in terms of successful packet delivery. Simulation result provides that the proposed TMC-Genetic node recovery algorithm outperforms compared to other related works in terms of the number of hops, end-to-end delay, total energy consumption, residual energy, routing overhead, throughput and network lifetime.</span>
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Cai, Wei, Xiao Man Du e Zhao Hui Wu. "A Preliminary Research on Operation Mode of Condensing Heat Recovery Hot Water Supply System for Water-Cooled Chillers". Applied Mechanics and Materials 55-57 (maggio 2011): 618–23. http://dx.doi.org/10.4028/www.scientific.net/amm.55-57.618.
Testo completoAbstract (sommario):
The objective of the present paper is to investigate the condenser heat recovery in water-cooled chiller system. According to the technology characteristics of vapor compression refrigerating cycle, the viewpoint of condensing heat reclaim was proposed, and heat recovery system can be used in buildings. Air-cooled and water-cooled chillers with heat reclaim capability were discussed. Three optimized water system designs were introduced for more heat recovery or higher heating water temperature. The results show that it is very useful for designing and developing the new heat recovery unit with high efficiency, energy conservation, and environmental protection by analyzing the feature feasibility of condenser heat recovery system. The control of entering-condenser water temperature is recommended for higher chiller efficiency and operating steadily, the water system designs of preferential loading and side stream are for more heat recovery.
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Koval, A., F. Mamontov, N. Marinich e Yu Rogovoy. "Dummy test rig design for in-hull propulsors of underwater objects". Transactions of the Krylov State Research Centre 1, n. 399 (15 marzo 2022): 102–10. http://dx.doi.org/10.24937/2542-2324-2022-1-399-102-110.
Testo completoAbstract (sommario):
Object and purpose of research. This research was intended to design and manufacture a dummy test rig for self-propulsion testing of various in-hull propulsors. This test rig will be used to test waterjet designs for underwater objects. Materials and methods. Analytical assessments on geometry of propeller and stator blades, numerical simulation of operational condition for two-row blade system operating in the water duct as per in-house KSRC techniques. Main results. Interaction of internal waterjets with the hull of underwater object has never been studied before. To estimate this interaction, it was decided to perform self-propulsion tests with a suitable hull model. This work included design and manufacturing of a dummy test rig representing a hull of underwater object and enabling hydrodynamic measurements for an in-hull waterjet. Another result of this work was design and manufacturing of a four-row in-hull propulsion unit. Conclusion. The dummy test rig manufactured in this work could be further used to optimize in-hull waterjets of various configurations. Apart from the configuration described in this paper, it could also be feasible to design, manufacture and apply a combined rim-driven propulsion motor in the initial part of the water duct.
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Pratama, Mukram Belto, Irvani Irvani e Mardiah Mardiah. "EVALUASI HASIL PENCUCIAN RAW MATERIAL KAOLIN TERHADAP KEBUTUHAN PRODUKSI UNIT PENGOLAHAN PT ANEKA KAOLINE UTAMA BELITUNG". MINERAL 6, n. 1 (1 aprile 2021): 31–37. http://dx.doi.org/10.33019/mineral.v6i1.3083.
Testo completoAbstract (sommario):
PT Aneka Kaoline Utama produces kaoline powder through two processes which are washing are washing unit and processing unit. Washing unit does the separation between tailing and kaoline with the extract as the result. The extract contains water and kaoline, then the water reduction will be processed in processing unit. Based on the information, writer evaluates the extract production in washing unit for fulfilling the needs of processing unit in PT Aneka Kaoline Utama using evaluation method and action research method. The steps are sampling raw material (feed), calculating the sediment pond’s dimention and the volume of full pond, sampling tailing in washing unit’s tools, observing the production’s process, and evaluating the needs off kaoline extract. The result of this research shows that raw material in washing unit were 3,847.4 ton in April, 3,606.2 ton in May, 2,594.9 ton June, and 3,890 in July which showed the amound of extract did not reach the target in processing unit. 69.2% of loose material and 21% loosing kaolin in average caused the recovery value in washing unit just reached 30.8%. Because of loose kaoline’s presence in washing unit, writer suggests the increasing of raw material and working hour as big as 27,056.3 ton per hour with 30.8% washing unit’s recovery so the company can produce 8.34 ton kaoline per hour and 4,000 ton kaoline per month.
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Rende, Sante Francesco, Alessandro Bosman, Fabio Menna, Antonio Lagudi, Fabio Bruno, Umberto Severino, Monica Montefalcone et al. "Assessing Seagrass Restoration Actions through a Micro-Bathymetry Survey Approach (Italy, Mediterranean Sea)". Water 14, n. 8 (15 aprile 2022): 1285. http://dx.doi.org/10.3390/w14081285.
Testo completoAbstract (sommario):
Underwater photogrammetry provides a means of generating high-resolution products such as dense point clouds, 3D models, and orthomosaics with centimetric scale resolutions. Underwater photogrammetric models can be used to monitor the growth and expansion of benthic communities, including the assessment of the conservation status of seagrass beds and their change over time (time lapse micro-bathymetry) with OBIA classifications (Object-Based Image Analysis). However, one of the most complex aspects of underwater photogrammetry is the accuracy of the 3D models for both the horizontal and vertical components used to estimate the surfaces and volumes of biomass. In this study, a photogrammetry-based micro-bathymetry approach was applied to monitor Posidonia oceanica restoration actions. A procedure for rectifying both the horizontal and vertical elevation data was developed using soundings from high-resolution multibeam bathymetry. Furthermore, a 3D trilateration technique was also tested to collect Ground Control Points (GCPs) together with reference scale bars, both used to estimate the accuracy of the models and orthomosaics. The root mean square error (RMSE) value obtained for the horizontal planimetric measurements was 0.05 m, while the RMSE value for the depth was 0.11 m. Underwater photogrammetry, if properly applied, can provide very high-resolution and accurate models for monitoring seagrass restoration actions for ecological recovery and can be useful for other research purposes in geological and environmental monitoring.
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Terui, Takeshi, Yasuo Hirayama, Takayuki Machino, Toshiro Kusakabe, Kenji Nakamura, Hiroyoshi Mihara, Satoko Itoh e Kunihiko Ishitani. "Recovery of cancer patients' social lives upon referral to palliative care units." Journal of Clinical Oncology 34, n. 26_suppl (9 ottobre 2016): 107. http://dx.doi.org/10.1200/jco.2016.34.26_suppl.107.
Testo completoAbstract (sommario):
107 Background: Our hospital is a cancer-specific facility that treats patients from diagnosis to terminal care. We evaluate the possibility of effective cancer chemotherapies for patients referred to our palliative care unit from other hospitals through case conferences in our institution. Even the patients referred to the palliative care unit of our institution are sometimes assessed as “very likely to be improved by standard or semi-standard treatment” by the palliative care and oncologic teams in our institution. We surveyed inappropriate cases that were mistakenly assessed as indicated for terminal care in their previous hospital. Methods: We reviewed 1535 patients referred to our palliative care unit from other hospitals because of anticancer chemotherapy contraindications over a 3-year period. We determined the number of the patients who were thought to actually have indications for cancer chemotherapy. Results: During the case conferences, 31 (2.0%) of the 1535 patients were thought to have indications for cancer chemotherapies. Standard chemotherapies were administered in our hospital to 6 patients. Four of the 6 patients were alive at one year and recovered their social life. Conclusions: Prudent assessment using updated guidelines are needed at the time of patient referral of a hospice. Ethical problems clearly exist with patients who were mistakenly assessed as indicated for terminal care in their previous hospital. There remains room for discussion of whether it is an ethical problem to overturn the will of a patient having chosen best supportive care (including those for whom it was presented as the only option by previous doctors or those who made positively the choice themselves) and proceed with cancer treatment.
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Lin, Shao Jian, Si Chen, Jian Wu Lan, Rong Hui Guo, Jiao Jiao Shang, Ya Ni Li e Jing Fan. "Research on Low Temperature Elastic Recovery Property of a Novel Poly(ester-Imide-Ether) Based on N-(4-Carboxyphenyl) Trimellitimide Unit". Advanced Materials Research 554-556 (luglio 2012): 122–25. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.122.
Testo completoAbstract (sommario):
The elastic recovery property of a novel poly(ester-imide-ether) (PEIE) was prepared from the 1, 4-butanediol (BD), poly(tetramethylene glycol) (PTMG1000) and imide dicarboxylic acid based on 1, 2, 4-benzenetricarboxylic (TMA) and aminobenzoic acid (PABA) was studied. The elastic recovery of the PEIE was studied in the fiber form. The influences of the draw ratio, temperature and heat treatment on elastic recovery were investigated. The results show that the novel PEIE possesses the excellent elastic recovery at low temperature and the quickly-changed temperature is lower than that of traditional poly(ester-ether)s. Meanwhile, the heat treatment process can improve the elastic recovery of the PEIE because this process improves the crystallization of the hard segments.