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Wang, Jin Yu, Guang Jie Fu, Dong Xue Lin y Chao Wang. "Research on Tower Crane Safety Control System Based on GPRS and U Disk Storage". Applied Mechanics and Materials 341-342 (julio de 2013): 901–5. http://dx.doi.org/10.4028/www.scientific.net/amm.341-342.901.
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Driven by the interests of the construction unit, field workers illegal operations and other reasons, tower crane collapse accidents occur frequently, personal injury or death became common occurrence. According to the nationalGB12602-2010 lifting mechanical overload protection device security technical specifications, security and monitoring equipment must be installed on the tower crane. The GPRS and U disk storage tower crane control system has catered to the national security specified requirements. By the control system, the data can not only be recorded and inquired, well it can also be wireless remote transmitted. Supervisors who are in units can also monitor the construction site online. Meanwhile, the system can control the tower crane operations according to the specific situation of overrun. The system has a good promotional value.
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Wang, Jin Yu, Guang Jie Fu, Dong Xue Lin y Chao Wang. "Signal Acquisition and Process on Tower Crane Safety Control System". Advanced Materials Research 753-755 (agosto de 2013): 2141–44. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.2141.
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Tower crane collapse accidents occur frequently, personal injury or death became a common occurrence. According to the nationalGB12602-2011 lifting mechanical overload protection device security technical specifications, security and monitoring equipment must be installed on the tower crane. The GPRS and U disk storage tower crane control system has catered to the national security specified requirements, record and inquires can be realized, at the same time, the control system can achieve data wireless remote. Supervising person that in the units can monitor the construction site online. Meanwhile, the system can control the tower crane operations according to the specific situation of overrun.
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Montonen, Jan-Henri, Niko Nevaranta, Markku Niemelä y Tuomo Lindh. "Comparison of Extrainsensitive Input Shaping and Swing-Angle-Estimation-Based Slew Control Approaches for a Tower Crane". Applied Sciences 12, n.º 12 (10 de junio de 2022): 5945. http://dx.doi.org/10.3390/app12125945.
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Tower cranes are needed to move heavy objects safely around construction sites. In tower cranes, payload oscillations are a typical problem that can cause safety issues, especially if the crane is not operated by an experienced user. Depending on the system, there are different causes for oscillations, e.g., inertial forces from the crane movement or external forces, such as weather conditions. Hence, the selected control law for input tracking plays an important role to limit the oscillatory motion and to help the crane operator to prevent unwanted operations. In this paper, we study the slew control of a tower crane application from the viewpoint of reducing payload oscillations. Two different approaches are studied: open-loop control based on extrainsensitive input shaping and closed-loop swing angle control, based on the estimation of the hoist cable angle. The proposed control approaches are validated by running the developed control program against a multibody mechanics simulator containing a model of a Liebherr tower crane. The studied control laws are also evaluated using an experimental setup, which consists of a two-axis manipulator, inverters, and a programmable logic controller in which the studied control methods are implemented. The results from the multibody dynamics simulations and from the experimental setup are presented and evaluated from the viewpoint of crane operation.
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Friedrich, Maik y Christoph Möhlenbrink. "How to Evaluate Remote Tower Metrics in Connection With Weather Observations". Aviation Psychology and Applied Human Factors 8, n.º 2 (septiembre de 2018): 100–111. http://dx.doi.org/10.1027/2192-0923/a000142.
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Abstract. Owing to the different approaches for remote tower operation, a standardized set of indicators is needed to evaluate the technical implementations at a task performance level. One of the most influential factors for air traffic control is weather. This article describes the influence of weather metrics on remote tower operations and how to validate them against each other. Weather metrics are essential to the evaluation of different remote controller working positions. Therefore, weather metrics were identified as part of a validation at the Erfurt-Weimar Airport. Air traffic control officers observed weather events at the tower control working position and the remote control working position. The eight participating air traffic control officers answered time-synchronized questionnaires at both workplaces. The questionnaires addressed operationally relevant weather events in the aerodrome. The validation experiment targeted the air traffic control officer’s ability to categorize and judge the same weather event at different workplaces. The results show the potential of standardized indicators for the evaluation of performance and the importance of weather metrics in relation to other evaluation metrics.
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Harry-Ngei, N., I. Ubong y P. N. Ede. "Review of the Scrubber as a Tool for the Control of flue Gas Emissions in a Combustion System". European Journal of Engineering and Technology Research 4, n.º 11 (1 de noviembre de 2019): 1–4. http://dx.doi.org/10.24018/ejeng.2019.4.11.1561.
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This paper focuses on the description, function and working principles of the wet gas scrubber required to control air pollution emissions from a combustion system of a boiler. Important points to note in the selection and operation of the scrubber as well as the different types of scrubbers commonly deployed in the industries to cut down on emissions were addressed. A comprehensive reviews of the removal mechanisms and schemes of the scrubber were reported for various research on the subject. The packed tower scrubber, however, was recommended because of varying advantages and ease of operations.
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Harry-Ngei, N., I. Ubong y P. N. Ede. "A Review of the Scrubber as a Tool for the Control of flue Gas Emissions in a Combustion System". European Journal of Engineering Research and Science 4, n.º 11 (1 de noviembre de 2019): 1–4. http://dx.doi.org/10.24018/ejers.2019.4.11.1561.
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This paper focuses on the description, function and working principles of the wet gas scrubber required to control air pollution emissions from a combustion system of a boiler. Important points to note in the selection and operation of the scrubber as well as the different types of scrubbers commonly deployed in the industries to cut down on emissions were addressed. A comprehensive reviews of the removal mechanisms and schemes of the scrubber were reported for various research on the subject. The packed tower scrubber, however, was recommended because of varying advantages and ease of operations.
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Al Hattab, Malak, Emile Zankoul, Mohammad Barakat y Farook Hamzeh. "Crane overlap and operational flexibility: balancing utilization, duration, and safety". Construction Innovation 18, n.º 1 (2 de enero de 2018): 43–63. http://dx.doi.org/10.1108/ci-11-2016-0062.
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Purpose With tower cranes being the site hubs, thoroughly planning and managing their operations can result in better construction performance. As urban spaces become more constricted, overlapping working radii of tower cranes becomes inevitable. While project planners are concerned with safety hazards, research has not comprehensively addressed workload distribution and synchronization of overlapping cranes. Therefore, this study aims at exploring the impact of overlapping cranes, used on high-rise buildings, on operational flexibility which is the balance between schedule duration, crane utilization and safety. Design/methodology/approach A simulation model was developed and applied on a real project to analyze and compare the impacts of different overlap sizes. Seven scenarios of different overlap sizes, i.e. different number of tasks falling in the overlap space, were executed in the model; their results were plotted and analyzed. Findings The outcomes result from several compounded factors such as the experience of planners and crane operators, the sequencing of critical versus non-critical activities and the overall effort and care taken when planning operations of overlapping cranes. Increasing overlap size can be beneficial or unfavorable depending on how properly planners allocate overlapping cranes to workload demand, keeping in mind that there are certain trade-offs while achieving operational flexibility. Originality/value While project planners are concerned with safety hazards associated with crane overlaps, research has not been comprehensively nor proactively addressing the workload distribution and synchronization of overlapping crane processes. This study contributes to science by addressing the need to harness the flexibility in using overlapping tower cranes while minimizing the resulting interruptions and safety risks. This study sheds light on the potential benefits of allowing cranes to overlap while considering their collision free operations. Operational flexibility is seen as the balance between achieving shorter schedule durations and higher crane utilizations while maintaining collision free motion paths.
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Mott, John H., Margaret L. McNamara y Darcy M. Bullock. "Accuracy Assessment of Aircraft Transponder–Based Devices for Measuring Airport Operations". Transportation Research Record: Journal of the Transportation Research Board 2626, n.º 1 (enero de 2017): 9–17. http://dx.doi.org/10.3141/2626-02.
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Accurate counts of aircraft operations at unmonitored or partially monitored general aviation airports are difficult to achieve, but they are important because of their effect on the allocation of federal and state airport improvement funds. Impediments to correctly counting aircraft operations include inaccuracies related to the acoustic counters that are commonly used to collect data and errors in the statistical procedures that extrapolate the sample data into meaningful counts. In response to these impediments, the authors developed a measurement technique that uses data from aircraft transponders to determine the occurrence of aircraft operations at these airports. To validate the accuracy of this technique, operations counts calculated from its use at a general aviation airport in the state of Indiana were compared with those obtained from the FAA’s Air Traffic Activity Data System database, which contains official operations data reported by airports with towers. This comparison, which was conducted using data for April 2016, indicated that the new technology provided values within 5% of the 7,837 total operations reported by tower operators. The transponder signal–counting technology thus appears to be an effective and inexpensive means of establishing accurate operations counts not only at these airports but potentially at the more than 2,800 of the 3,331 airports in the National Plan of Integrated Airport Systems that lack associated air traffic control towers.
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Ameduri, Salvatore, Monica Ciminello, Antonio Concilio, Ignazio Dimino, Bernardino Galasso, Mariano Guida, Marco Fabio Miceli et al. "Whirl Tower Demonstration of an SMA Blade Twist System". Actuators 11, n.º 6 (25 de mayo de 2022): 141. http://dx.doi.org/10.3390/act11060141.
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This paper focuses on the development and demonstration of a novel blade morphing system within a whirl tower facility. The scope is to investigate the behavior of the proposed architecture under representative loads, demonstrating its capability to alter the blade original shape in operation under centrifugal, aerodynamic, and internal forces. The morphing concept was developed inside the European project “Shape Adaptive Blades for Rotorcraft Efficiency”, SABRE, and consists of a shape memory alloy system able to change the original twist law and, in this way, enhance rotor performance at certain specific regimes, such as hover and vertical flight. These phases, indeed, are generally penalized with respect to other more extended flight regimes (cruise). The work starts with an overview of the research in the field of morphing, with specific reference to the researches envisaging rotary wing demonstrations. Then, an overview of the morphing twist concept is provided, with particular attention paid to those features particularly suited for the whirl tower representative test environment. The laboratory characterization and commissioning operations are illustrated. Then, the task of the installation of the prototype on the whirl tower facility is described together with the testing modality adopted. Finally, the results of the test campaign are illustrated and critically discussed, providing the reader with insights and possible future steps to be taken in further research. The impact on the morphing capability of the following different parameters was investigated: the number of the prototype segments switched on, the speed and thus the centrifugal actions, and the angles of attack. The stiffening effect due to centrifugal actions was quantified through the measurement of the actual twist and the internal deformation. The link between speed, angle of attack at root, and twist and flap angles was also tracked, building a database useful for the comprehension of the phenomenon, and for the assessment of numerical predictive models. The achieved results highlighted the capability of the system to produce a twist angle matching the target of 8° per blade radius; this figure is related to a potential power saving of 10% in hover and vertical flight and an improvement of about 1% on the over-all efficiency of the rotorcraft.
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Jin, Lianghai, Han Liu, Xiazhong Zheng y Shu Chen. "Exploring the Impact of Wind Loads on Tower Crane Operation". Mathematical Problems in Engineering 2020 (31 de julio de 2020): 1–11. http://dx.doi.org/10.1155/2020/2807438.
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The construction industry continues to be one of the industries with the highest accident rate. Tower cranes have always been the central component of many construction operations. With recent advancements in tower cranes, more efforts have been made for their safe operation. The impact of natural environmental factors on the operation of tower cranes cannot be ignored, especially the impact of the wind load, which can be found in construction regulations worldwide. Therefore, a large number of recent studies have focused on exploring different approaches to improving the impact of loads, such as improved feedback controllers and collocated sensors. However, there are few studies on the impact of the flexible cable pendulum system under wind load. To quantify the impact in this paper, first, the swing model of the hanging and the model of sling fluctuation are proposed as the base. Second, the flexible cable pendulum model is designed for the impact of tower cranes under wind load. By field experiments, the applicability of the model in practical use is analyzed. A case of the Crane Beach Hydropower Station is investigated as a demonstration. With MATLAB programming, the variation in the hanging impulse with wind speed is shown, indicating that the maximum wind speed should be 12 m/s if the factors that people can control are considered. When considering the factors that can be harmful to humans, the maximum wind speed is 17 m/s. With the proposed model, the impacts of wind load on tower crane operation can be quantified without actual deployment, offering a more straightforward quantitative tool for safe regulations and engineering management.
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Dzhuma, Liudmyla, Oleh Dmitriiev, Oleksii Lavrynenko y Mykhailo Soroka. "Revealing the regularities related to the professional activities of the air traffic controller of airport traffic control tower". Technology audit and production reserves 3, n.º 2(59) (30 de junio de 2021): 29–40. http://dx.doi.org/10.15587/2706-5448.2021.235456.
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The object of research is the professional activity of an air traffic controller of the airport traffic control tower (henceforth Tower controller). The subject of research is the regularities revealing in this specialist activity in the performance of its work responsibility for the trainee reference model formation in the intelligent training system «ATC of Tower». One of the most problematic areas is the lack of training systems that would allow for independent training of these aviation specialists, whose knowledge assessment would be automatic and objective. The study used methods of analysis, combined timing, synthesis, statistical analysis and probabilistic modelling. The approach to data collection and analysis proposed as part of study made it possible to obtain an information flows circulation model at the Tower controller workplace and formalize the time characteristics of technological operations performed by it during the aircraft landing procedure. This is fundamentally important for the development of the trainee reference model of the intellectual training system, as well as for the implementation of the training mode and automatic objective assessment of the student’s knowledge and skills. The approbation obtained results of this approach of data collection and analysis make it possible to consider it an effective tool for obtaining objective information about the subject area of the Tower controller’s professional activity, which is a complex continuous-discrete stochastic dynamic control system with a mixed structure. In contrast to the formation of reference models existing approaches, the approach to collecting and analysing data proposed in the work makes it possible to develop a trainee reference model that more fully describes the Tower controller’s activities. Also, the proposed model reflects the order of actions, and when interacting with the trainee current model, it allows to implement objective (without an instructor) automatic assessment.
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Lagerev, Alexander. "Simulation of the hydraulic drive operation of the end tower installation mechanism on a self-propelled chassis as part of a mobile ropeway". Nauchno-tekhnicheskiy vestnik Bryanskogo gosudarstvennogo universiteta 8, n.º 2 (25 de junio de 2022): 110–24. http://dx.doi.org/10.22281/2413-9920-2022-08-02-110-124.
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Single-span ropeways based on autonomous self-propelled wheeled chassis of high load capacity and cross-country capability are a promising type of mobile transport and overloading equipment for the rapid creation of logistics infrastructure for the sustainable development of hard-to-reach areas with complex natural terrain. They can also be effectively used for rapid deployment during transport operations in the foci of natural or man-made disasters. This article presents a mathematical model of the operation of a hydraulic drive with throttle control with sequential activation of adjustable throttles and a power hydraulic cylinder in relation to the mechanism of installing the end tower on the load-bearing frame of a self-propelled wheeled chassis of a mobile ropeway. The model includes a submodel of kinematic and force analysis of the end tower installation mechanism and a submodel of hydrodynamic analysis of working processes in the volumetric pumping hydraulic drive of this mechanism. The established calculated dependences make it possible to simulate the change during the time of installation of the end tower from the transport position to the working position of the basic quantitative parameters, including the speeds and accelerations of movement of the end tower and the rod of the lifting hydraulic cylinder, pressures and volumetric flow rates of the working fluid at characteristic points of the hydraulic system.
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Al-Hussein, Mohamed, Muhammad Athar Niaz, Haitao Yu y Hyoungkwan Kim. "Integrating 3D visualization and simulation for tower crane operations on construction sites". Automation in Construction 15, n.º 5 (septiembre de 2006): 554–62. http://dx.doi.org/10.1016/j.autcon.2005.07.007.
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Takagi, Tsubasa y Miwa Nakanishi. "Efficiency-Thoroughness Trade-Off Characteristics of Air Traffic Controllers During Tower Operations". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 64, n.º 1 (diciembre de 2020): 1745–49. http://dx.doi.org/10.1177/1071181320641423.
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Air traffic demand has been growing for years and many countries are trying to solve this situation by modernizing their national airspace through advanced automation. Those projects aim to provide a greater level of efficiency while ensuring a safe flow of air traffic. However, human air traffic controllers have been coping with difficult situations and unexpected events by flexibly balancing efficiency and thoroughness throughout their operations. In this study, we conducted an experiment using a simulator depicting air traffic control tower operations and analyzed the trade-off decisions made by humans under varying situations. By doing so, we proposed a model with the aim of applying the results to future air traffic management systems. This could allow those autonomous systems to make decisions that are similar to those of human preferences, which could lead to a proactive management of safety and a higher level of automation acceptance.
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O'Mahony, M., A. Lakhani, A. Stephens, J. G. Wallace, E. R. Youngs y D. Harper. "Legionnaires' disease and the sick-building syndrome". Epidemiology and Infection 103, n.º 2 (octubre de 1989): 285–92. http://dx.doi.org/10.1017/s0950268800030648.
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SUMMARYIn October 1985, six cases of legionnaires' disease were associated with a police headquarters building. Four were amongst staff who worked in or visited the communications wing of the headquarters and two cases occurred in the local community. A case-control study implicated the operations room of the communications wing as the main area associated with infection. This wing was air-conditioned and smoke tracer studies showed that drift from the exhaust as well as from the base of the cooling tower entered the main air-intake which serviced the air-conditioning system.Legionella pneumophilaserogroup 1 subgroup pontiac was isolated from water and sludge in the cooling tower pond. Contaminated drift from the top of the cooling tower was probably responsible for the two community cases. An additional discovery was that symptoms suggestive of the sick-building syndrome were associated with working in this wing.
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Majumdar, A. A. K. "The generalizedppeg tower of hanoi problem". Optimization 32, n.º 2 (enero de 1995): 175–83. http://dx.doi.org/10.1080/02331939508844045.
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Джума, Людмила Миколаївна, Олег Миколайович Дмітрієв, Олексій Сергійович Лавриненко y Михайло Юрійович Сорока. "Метод формування еталонної моделі суб'єкта навчання інтелектуальної навчальної системи «Диспетчер Tower»". Aerospace technic and technology, n.º 4 (27 de agosto de 2021): 87–96. http://dx.doi.org/10.32620/aktt.2021.4.12.
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The rapid development of information technologies significantly affects all spheres of human activity, and if they are introduced into the training of aviation specialists, it becomes possible to shift the emphasis to the subject of training (trainee) independent work. The intelligent training system "ATC of Tower", which is being developed at the Information Technologies Department of the Flight Academy of the National Aviation University, aims to provide such an opportunity when training an air traffic controller of airport traffic control tower (henceforth Tower controller). For the system to meet modern requirements for intelligent training systems of this kind, it must support the user at the training stage and determine the level of his knowledge at the control stage. The implementation of such functions becomes possible when the current and reference models of the subject of training are implemented into the system. The reference model in the process of system functioning closely interacts with the current model, thereby ensuring the fixation of mistakes made by the trainee. Based on mistakes, the intelligent system forms an individual training trajectory for the subject of training. The implementation of the reference model, which is one of the main tasks of the above-mentioned system development, becomes possible due to the use of the proposed method of forming the trainee reference model, which is discussed in this article. The proposed method consists of several stages, each of which is a systematized set of modified (taking into account the specifics of the subject area) known methods. The method allows one to obtain such components of the reference model of the learning subject as the list of technological operations, the correctness of which must be monitored from the point of view of qualitative and quantitative indicators; the procedure (algorithm) for performing these technological operations, depending on the situation, which is determined by the air and/or ground situation, aircraft performance characteristics, weather conditions, etc.; information flows circulation model at the workplace of a given specialist, as well as reference values of the time spent on each technological operation, which provides the possibility of an objective automatic assessment of the operator's activity of the trainee.
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Mason, William P., Alexander J. Shturmakov, Jay A. Johnson y Scott Haman. "A new 122 mm electromechanical drill for deep ice-sheet coring (DISC): 2. Mechanical design". Annals of Glaciology 47 (2007): 35–40. http://dx.doi.org/10.3189/172756407786857640.
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AbstractThe deep ice-sheet coring (DISC) drill consists of four major mechanical drilling subsystems and four subsystems supporting on-surface activities. The mechanical drilling subsystems are a drill sonde, a drill cable, a tower and a winch. The drill sonde is the down-hole portion of the drill system and consists of six distinct sections: (1) the cutter head, (2) the core barrel, (3) the screen section, (4) the motor/pump section, (5) the instrument section and (6) the upper sonde, which includes anti-torques and drill cable terminations. The drill cable not only provides the means of supporting the drill sonde in the borehole, but also provides conduits for electrical power and data transmission. The tower tilts to allow the drill sonde to be serviced in the horizontal position without removing it from the tower. The winch provides a means of quickly raising the sonde from the borehole and providing the fine control necessary for coring operations.
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Hayashi, Miwa y Victoria L. Dulchinos. "Cardiac-Activity Measures for Assessing Airport Ramp-Tower Controller’s Workload". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 60, n.º 1 (septiembre de 2016): 71–75. http://dx.doi.org/10.1177/1541931213601016.
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Heart rate (HR) and heart rate variability (HRV) potentially offer objective, continuous, and non-intrusive measures of human-operator’s mental workload. Such measurement capability is attractive for workload assessment in complex laboratory simulations or safety-critical field testing. The present study compares mean HR and HRV data with self-reported subjective workload ratings collected during a high-fidelity human-in-the-loop simulation of airport ramp traffic control operations, which involve complex cognitive and coordination tasks. Mean HR was found to be weakly sensitive to the workload ratings, while HRV was not sensitive or even contradictory to the assumptions. Until more knowledge on stress response mechanisms of the autonomic nervous system is obtained, it is recommended that these cardiac-activity measures be used with other workload assessment tools, such as subjective measures.
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Majumdar, A. A. K. "The generalized four-peg tower of hanoi problem". Optimization 29, n.º 4 (enero de 1994): 349–60. http://dx.doi.org/10.1080/02331939408843963.
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Bouzalakos, S., B. Jefferson, P. J. Longhurst y R. M. Stuetz. "Developing methods to evaluate odour control products". Water Science and Technology 50, n.º 4 (1 de agosto de 2004): 225–32. http://dx.doi.org/10.2166/wst.2004.0269.
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An economical and practical alternative to the standard end-of-pipe odour control methods is the application of liquid odour control products. Currently, there are no established product-testing methods. The data that are available are often of questionable quality and may have limited relevance to waste management. Waste facilities receive differing streams of waste at varying loading volumes. Whilst in operation this exposes control products to a wide variety of environmental conditions, further increasing the difficulty of selecting an effective means of control. The current study initially identifies commercially available odour control products applicable for solid and liquid waste management operations. Bench-scale batch absorption tests have been carried out to investigate odorous gas abatement for a range of selected commercial products and water at a range of pH values. Hydrogen sulphide was the test odorous gas, as it is commonly associated with waste processes. Gas-phase volumetric mass-transfer coefficients (KGa) have been calculated to determine mass-transfer performance. The development of a pilot-scale spray tower is then presented as the testing apparatus for future work. This is an attempt to construct a repeatable testing method for evaluating abatement performance of odour control products, and control the problems encountered when applying odour control products to open sites. KGa values and data collected from tests in this study will be considered in future work as design parameters for the rig.
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McKelvey, Robert K. "Colour Dependence and Surplus Information in Airport Visual Aids During VFR Operations". Journal of Navigation 40, n.º 2 (mayo de 1987): 206–26. http://dx.doi.org/10.1017/s037346330000045x.
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Airport visual aids are examined for failure of transfer from chromatic (i.e. normal) to achromatic viewing situations which would suggest a non-redundant use of colour, and for their information value during VFR (visual flight rule) operations as a function of the airport operating classification for which they were designed. From photographs taken under visual meteorological conditions at night, slide sequences representing the visual presentations associated with aircraft movements during taxi-out, take-off, approach and landing operations were prepared and shown to experienced pilots in a time-stressed forced-choice procedure. The results suggest that among displays in current use only the signal light from the control tower is completely colour-dependent. Also, the information value of some taxi-way and approach lighting components might be questioned. An argument is presented for a ‘building-blocks’ review of the airport visual-aids system that could in some cases result in improved relationships between economy of display content and information value.
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Kloppers, Johannes C. y Detlev G. Kröger. "Cost optimization of cooling tower geometry". Engineering Optimization 36, n.º 5 (octubre de 2004): 575–84. http://dx.doi.org/10.1080/03052150410001696179.
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FUKASAWA, Shinichi y Yusuke SUZUKI. "An Evaluation of Augmented Reality Function to Reduce the Wide-Area Surveillance Workload for Remote Air Traffic Control Tower Operations". Japanese Journal of Ergonomics 58, Supplement (30 de julio de 2022): 1E2–04–1E2–04. http://dx.doi.org/10.5100/jje.58.1e2-04.
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Anand, Gopalakrishnan, Donald C. Erickson y Ellen Makar. "Subfreezing Absorption Refrigeration for Industrial CHP". International Journal of Air-Conditioning and Refrigeration 26, n.º 04 (diciembre de 2018): 1850033. http://dx.doi.org/10.1142/s2010132518500335.
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The design and operation of an advanced absorption refrigeration unit (Thermochiller) as part of an industrial combined heat and power (CHP) system is presented. The unit is installed at a vegetable processing plant in Santa Maria, California. The overall integrated system includes the engine package with waste heat recovery, Thermochiller, cooling tower, and chilling load interface. The unique feature of the system is that both the exhaust and jacket heat are used to supply subfreezing refrigeration. To achieve the low refrigeration temperatures of interest to industrial applications, all components of this integrated system needed careful consideration and optimization. The CHP system has a low emission natural gas-fired 633[Formula: see text]kW reciprocating engine cogeneration package. Both the exhaust heat and jacket heat are recovered and delivered via a hot glycol loop with 105[Formula: see text]C supply temperature and 80[Formula: see text]C return. The 125 ton ammonia absorption chiller (TC125) chills propylene glycol to [Formula: see text]C and has a coefficient of performance of 0.63. TC125 has peak electric demand of 10[Formula: see text]kW for pumps and 8[Formula: see text]kW for the cooling tower fan. The CHP system, including TC125, operates 20[Formula: see text]h per day, six days per week. All operations of TC125 are completely automatic and autonomous, including startups and shutdowns. Industrial refrigeration is typically a 24/7 load and highly energy-intensive. By converting all the engine waste heat to subfreezing refrigeration, Thermochiller brings added value to cogeneration or CHP projects.
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Omar, H. M. y A. H. Nayfeh. "Anti-Swing Control of Gantry and Tower Cranes Using Fuzzy and Time-Delayed Feedback with Friction Compensation". Shock and Vibration 12, n.º 2 (2005): 73–89. http://dx.doi.org/10.1155/2005/890127.
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We designed a feedback controller to automate crane operations by controlling the load position and its swing. First, a PD tracking controller is designed to follow a prescribed trajectory. Then, another controller is added to the control loop to damp the load swing. The anti-swing controller is designed based on two techniques: a time-delayed feedback of the load swing angle and an anti-swing fuzzy logic controller (FLC). The rules of the FLC are generated by mapping the performance of the time-delayed feedback controller. The same mapping method used for generating the rules can be applied to mimic the performance of an expert operator. The control algorithms were designed for gantry cranes and then extended to tower cranes by considering the coupling between the translational and rotational motions. Experimental results show that the controller is effective in reducing load oscillations and transferring the load in a reasonable time. To experimentally validate the theory, we had to compensate for friction. To this end, we estimated the friction and then applied a control action to cancel it. The friction force was estimated by assuming a mathematical model and then estimating the model coefficients using an off-line identification technique, the method of least squares (LS).
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Telychko, Hanna, Dmytro Romanenkov, Bohdan Kariev y Andrii Rogozhyn. "DEVELOPMENT OF AN AUTOMATIC WATER SUPPLY CONTROL SYSTEM FOR A REMOTE VILLAGE". Naukovyi visnyk Donetskoho natsionalnoho tekhnichnoho universytetu, n.º 1-2 (2022): 119–27. http://dx.doi.org/10.31474/2415-7902-2022-1(8)-2(9)-119-127.
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Purpose. Modernization of existing solutions for automatic control of water supply in a remote village. Methodology. The integrated approach to analyze the design object, to choose of the concept of building a water supply management system, to use mathematical methods for the study of operations, and the description of the control and management system have been used for the research. Results. The article provides a critical analysis of existing modern solutions for water supply in remote villages. Water consumption and water supply sources for the population, namely water intake wells, and calculation of the volume of the water tower, have been determined. Frequency regulation of pumping units and principles of automation of pumping stations have also been given. Priority directions for further research to improve the efficiency of water supply has been established. An algorithm for monitoring and controlling of autonomous water supply has been developed, and a SCADA system has been created to monitor the status of the pumping station. Scientific novelty. A unique water supply system has been proposed instead of the centralized one. A SCADA system to control the current state of the complex has been created. Practical significance. Optimization model of the automatic control system of the water supply of a remote village with a backup power supply and real-time control of the system. This solution has been designed for the full cycle of water supply, to reduce costs. It ensures uninterrupted water supply, optimize the operation of pumping stations and adapt the existing infrastructure to changing water quality requirements.
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Balzarek, Christoph, Steffen Kalow, Johannes Riemenschneider y Andres Rivero. "Manufacturing and Testing of a Variable Chord Extension for Helicopter Rotor Blades". Actuators 11, n.º 2 (9 de febrero de 2022): 53. http://dx.doi.org/10.3390/act11020053.
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Helicopters are still an indispensable addition to aviation in this day and age. They are characterized by their ability to master both forward flight and hover. These characteristics result in a wide range of possible operations. Key for the design of the rotor blades is a blade design that always represents a compromise between the different flight conditions, which enables safe and efficient flight in the various flight conditions. In order to operate the rotor blade even more efficiently in all flight conditions, a new morphing concept, the so-called linear variable chord extension, has been developed. Here, the blade chord length in the root area is changed with the help of an elastic skin to adapt it to the respective flight condition. The simulations performed for this concept showed a promising increase in overall helicopter performance. The fabrication of the resulting demonstrator as well as the tests in the whirl-tower and wind tunnel are presented in this paper. The results of the tests show that the concept of linear variable chord extension has a positive influence and a great potential for hovering flight.
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Jiang, Wei, Yu Yan, An Zhang, Lianqing Yu, Gan Zuo, Hong Jun Li y Wei Chen. "Live maintenance robot for high-voltage transmission lines". Industrial Robot: the international journal of robotics research and application 46, n.º 5 (19 de agosto de 2019): 711–18. http://dx.doi.org/10.1108/ir-03-2019-0057.
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Purpose The purpose of this paper is to improve the operation and maintenance intelligence of power systems, and summarize the transmission line robots and their key technologies. High-voltage power cables are important channels for power transmission systems. Their special geographical environment and harsh natural environment can lead to many different faults. At present, such special operations in dangerous and harsh environments are performed manually, which have not only high labor intensity and low work efficiency but also great personal safety risks. Design/methodology/approach For maintenance works that are far away from the tower, power outages are required. With the increasing evaluation of transmission quality and operational safety, and the urgent need for automation and operation of modern power systems, the contradiction between this manual operation and modern high-quality power transmission has become increasingly prominent. An effective method to replace the manual maintenance work is to use the mobile robot to carry the operation manipulator and its end tool, that is, the live maintenance robot. Findings Some achievements have been made in the key technologies of live maintenance robots, the work to be done to meet the basic requirements of complex and changeable line environment and practical application. Based on the existing research results of live overhaul robot, the follow-up research will focus on the practical application needs and the frontier of scientific and technological development, and truly realize the human–machine integration between live overhaul robot–human working environment. Only in this way can the robot better serve the operation and maintenance of the power system. Originality/value This paper reviews the system platform, operation function, structural characteristics and key technologies involved in the power cable robot, and the combination of live maintenance robots and modern high-tech such as big data and cloud computing is also given, and finally, the future development direction of the special operation robot is pointed out.
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Andrews, A. E., J. D. Kofler, M. E. Trudeau, J. C. Williams, D. H. Neff, K. A. Masarie, D. Y. Chao et al. "CO<sub>2</sub>, CO and CH<sub>4</sub> measurements from the NOAA Earth System Research Laboratory's Tall Tower Greenhouse Gas Observing Network: instrumentation, uncertainty analysis and recommendations for future high-accuracy greenhouse gas monitoring efforts". Atmospheric Measurement Techniques Discussions 6, n.º 1 (8 de febrero de 2013): 1461–553. http://dx.doi.org/10.5194/amtd-6-1461-2013.
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Abstract. A robust in situ CO2 and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Tall Tower Greenhouse Gas Observing Network. The network uses very tall (> 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary layer trace gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO2 and CH4. The long-term stability of the systems in the field is typically better than 0.1 ppm for CO2, 6 ppb for CO, and 0.5 ppb for CH4, as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures and flow rates that are inputs for automated alerts and quality control algorithms. These algorithms provide detailed and time-dependent uncertainty estimates for all of the gases and could be adapted to other species or analysis systems. The design emphasizes use of off the shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with > 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.
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Majumdar, A. A. K. "The Divide-and-Conquer Approach to the Generalizedp-Peg Tower of Hanoi Problem". Optimization 34, n.º 4 (enero de 1995): 373–78. http://dx.doi.org/10.1080/02331939508844121.
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Octavianie, Adhitya y Aqram Adi Putra. "Telephone Damage Analysis on Voice Control Unit (VCU) At Perum LPPNPI Manado Branch Office". Airman: Jurnal Teknik dan Keselamatan Transportasi 4, n.º 1 (24 de junio de 2021): 47–51. http://dx.doi.org/10.46509/ajtk.v4i1.180.
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Voice Communication Control System (VCCS) is a tool designed to make it easier for users to communicate voice by integrating all users (clients) and means of communication in one system and controlled using a control panel. VCCS is a voice switching device used in VHF A / G and Direct Speech communications. The benefit of using VCCS is that when the user makes flight communication it becomes easy because all frequencies and telephones are combined in a VCU (Voice Control Unit) so that the ATC desk/work desk is not filled with communication devices. In addition, to facilitate its use, the VCCS client control panel uses a touch screen system. AirNav Indonesia Manado Branch has a LESS brand VCCS equipment server manufactured by China. VCCS consists of two main parts, namely the server and client. The server is a processing center and control center for switching input and output, while the client or VCU (Voice Control Unit) is the device used by the user in VCCS operations. There are 7 VCUs at AirNav Indonesia Manado which are placed in the Tower room (3 VCU), APP room (3 VCU), and FSS Kompen room (1 VCU).
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Liang, Wang, Yang Lu-lu y Tian Ya-bin. "Study on Energy Efficient Operation of Air-Conditioning Cooling Water System". Open Electrical & Electronic Engineering Journal 9, n.º 1 (26 de febrero de 2015): 53–60. http://dx.doi.org/10.2174/1874129001509010053.
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The control logic of frequency adjustment for pump and cooling tower fan has been presented in this paper, based on the operation mode of a chiller with one pump and one cooling tower. Optimum outlet water temperature control of cooing tower has been put forward through analysis and comparison among factors influencing it, based on measured data. A mathematical model of energy consumption has been established under different outdoor wet-bulb temperature and load rate conditions. The optimized controlling strategy has been obtained after the analysis on energy consumption under two different operational strategies with different number of cooling towers in service. In partial load condition, the best operation mode of cooling water system is the optimal water outlet temperature control system, which aims at the lowest comprehensive system energy consumption. Cooling water system can match the best temperature difference and determine the fan frequency according to optimum outlet temperature automatically. Variable frequency control should be applied to fans; meanwhile, routing maintenance and cleaning is also needed for an even distribution of water and effective use of heat exchange area.
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Song, Xiangbo. "Automatic bridge crack detection device based on quadrotor UAV". Journal of Physics: Conference Series 2031, n.º 1 (1 de septiembre de 2021): 012004. http://dx.doi.org/10.1088/1742-6596/2031/1/012004.
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Abstract For the bridge located in deep valley, with high tower and long span structure, the traditional artificial crack detection can not meet the needs of today. In order to solve this problem, a new bridge crack detection equipment is designed based on quadrocopter unmanned aerial vehicle. According to this equipment, the developed system contains: reconnaissance unmanned aerial vehicle system, acquisition and transmission system, crack positioning system, and graphics operations system. Reconnaissance UAV system is improved based on quadrocoper UAV to meet the requirements of flight power, flight control, flight safety and signal stability. In the integrated transmission system, the designed UAV equipped with Hawkeye 5S motion camera, and 4G communication is used to complete the real-time image transmission; The crack location system uses BDS / GPS dual-mode combined single-point positioning module to realize the accurate location of bridge surface cracks; Graphics operations system, based on C++ and python language, designed a superpotent actual-time video streaming graphics operations method, and used median filter, image grayscale, histogram equalization, threshold segmentation and other methods to process the crack image. The designed bridge crack detection equipment can effectively solve the problem of low crack detection efficiency, and realize the intelligence and automation of crack identification. It has practical engineering application value and promotes the development of bridge crack detection technology.
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Padrigalan, Kathleen Ebora y Jui-Hung Liu. "A Wind-Turbine-Tower-Climbing Robot Prototype Operating at Various Speeds and Payload Capacity: Development and Validation". Applied Sciences 13, n.º 3 (20 de enero de 2023): 1381. http://dx.doi.org/10.3390/app13031381.
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The development of control technology on wind turbine application robots has played an integral role in facilitating the digitization of inspection and maintenance in the wind energy industry. This paper presents a wind-turbine-climbing robot that determines the service lifespan of the wind turbine components subject to its payload capacity. The model has four rubber wheels, as the driving mechanism for its locomotion is being supported by a Bowden cable as a winding mechanism for its adhesion. The design further incorporates an Arduino microcontroller, distance sensors, motors, and a step motor to form its electromechanical structure. The overall capability of the robot has been analyzed through its kinematics and dynamics. Practical indoor experiments using a wind turbine tower mockup have been conducted for the validation of the various speeds and payload capacity of the prototype. The results indicate the effectiveness of its driving and winding mechanism to climb at the various speeds and with or without a payload. The advantage of the operations of its mechanism conformed with the wind turbine application robots.
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Maneengam, Apichit y Apinanthana Udomsakdigool. "A Set Covering Model for a Green Ship Routing and Scheduling Problem with Berth Time-Window Constraints for Use in the Bulk Cargo Industry". Applied Sciences 11, n.º 11 (25 de mayo de 2021): 4840. http://dx.doi.org/10.3390/app11114840.
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This paper presents a set covering model based on route representation to solve the green ship routing and scheduling problem (GSRSP) with berth time-window constraints for multiple bulk ports. A bi-objective set covering model is constructed with features based on the minimization of the total CO2 equivalent emissions and the total travel time subject to a limited number of berths in each port, berthing time windows, and the time window for each job. The solutions are obtained using the ε-constraint method, after which a Pareto frontier is plotted. This problem is motivated by the operations of feeder barges and terminals, where the logistics control tower is used to coordinate the routing and berthing time of its barges. We show that the proposed method outperforms the weighted sum method in terms of the number of Pareto solutions and the value of the hypervolume indicator.
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Zhang, Zhen Zhen, Hong Liu Xu, Xiao Guan y Bin Wang. "Intelligent Safety Control System for Operation of Group Tower Cranes". Applied Mechanics and Materials 330 (junio de 2013): 592–97. http://dx.doi.org/10.4028/www.scientific.net/amm.330.592.
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An intelligent safety control system for operation of group tower cranes was developed in the context of rising security problems during operation of group tower cranes. The anti-anti-collision principle includes self-anti-collision and multi-tower cranes anti-collision. The system consists of PLC module, Touch screen, signal receiving module, data acquisition module, control module and signal transmitting module. Several techniques such as digital coding, early warning, failure diagnosis, wireless communication, intelligent design and humanization design are applied in the system. Operational parameters of tower canes are detected in real time insure the safety for cross operation of several tower cranes.
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Izak, Krzysztof. "Twentieth anniversary of September 11. The plot, the events and the aftermath of the terrorist attack on the USA". Przegląd Bezpieczeństwa Wewnętrznego 13, n.º 25 (2021): 341–69. http://dx.doi.org/10.4467/20801335pbw.21.033.14310.
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world, was carried out by 19 people. Among them were 15 Saudis, two UAE nationals, a Lebanese and an Egyptian. Three of the four formed the Hamburg cell, which was the backbone of the entire plot. It was led by the Egyptian Muhammad Atta el-Sayed. He flew Boeing 767 aircraft American Airlines Flight 11, which first struck the North Tower of the WTC. Marwan al-Shehhi was the pilot of Boeing 767 aircraft United Airlines Flight 175, which crashed into the South Tower of the WTC. Hani Hanjour sat at the controls of the Boeing 757 aircraft American Airlines flight 77. It was the third machine to target the Pentagon. The pilot of the fourth plane - Boeing 757 aircraft United Airlines Flight 93 - Ziad Jarrah failed to reach his destination, possibly the Capitol, because the passengers decided to take over the control of the plane from the terrorists. The machine crashed in Pennsylvania. In the events of 9/11, a total of 2,996 people were killed, including 19 terrorists, and 6,291 were injured . Six Poles were among the fatalities. 343 firefighters died in the rescue operation. The attacks caused enormous material losses. Particularly high costs were incurred by insurance and reinsurance companies, airlines and aircraft manufacturers, as well as the tourism industry. The huge losses related to the destruction of the New York City World Trade Center and the disruption of the financial system had to be covered by insurance companies involved in the operations on the American market. The terrorist attack on the USA was the impetus for the largest reform of the American secret services since 1947. Washington made a decision regarding the need to create a system that would effectively counteract terrorist threats and effectively warn in the event of their occurrence. This was related to the strengthening of structures with operational and reconnaissance powers, increasing the scope of their tasks and improving their ability to coordinate. Most of the legal regulations were expressed in the document commonly known as the USA Patriot Act of 26 October 2001. The most critical, however, were the international repercussions. By the attacks on the WTC and the Pentagon, al-Qaeda influenced world politics by prompting Washington to declare a “war on terror”. Within its framework, American forces, supporting the so-called Northern Alliance led to the collapse of the Islamic Emirate of Afghanistan, and then entered Iraq, which in the long run turned out to be one of the most spectacular and deadly strategic mistakes in the history of the military. At the same time the September 11 attacks sparked many conspiracy theories. Their propagation in the media, in documentaries, as well as in articles, contributed to undermining trust in the American government. An organization called Architects and Engineers for 9/11 Truth which boasts 3.3 thousand architects and engineers from all over the United States, is still very active in researching the case of 7 WTC. Its mission is to establish the truth that the twin towers did not collapse due to the impact of terrorist-piloted planes, as well as the destruction of WTC 7 was not a result of the detachment of a fragment of the second plane. In the opinion of members of this organisation, the damage caused by the planes was far from sufficient to lead to such a catastrophe. They believe someone must have planted explosives.
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Liu, Jingnan, Lixin Zhang, Yongbao Chen, Zheng Yin, Yan Shen y Yuedong Sun. "Study of the Technologies for Freeze Protection of Cooling Towers in the Solar System". Energies 15, n.º 24 (19 de diciembre de 2022): 9640. http://dx.doi.org/10.3390/en15249640.
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A cooling tower is an important guarantee for the proper operation of a solar system. To ensure proper operation of the system and to maintain high-efficiency points, the cooling tower must operate year-round. However, freezing is a common problem that degrades the performance of cooling towers in winter. For example, the air inlet forms hanging ice, which clogs the air path, and the coil in closed cooling towers freezes and cracks, leading to water leakage in the internal circulation. This has become an intractable problem that affects the safety and performance of cooling systems in winter. To address this problem, three methods of freeze protection for cooling towers are studied: (a) the dry and wet mixing operation method—the method of selecting heat exchangers under dry operation at different environments and inlet water temperatures is presented. The numerical experiment shows that the dry and wet mixing operation method can effectively avoid ice hanging on the air inlet. (b) The engineering plastic capillary mats method—its freeze protection characteristics, thermal performance, and economics are studied, and the experiment result is that polyethylene (PE) can meet the demands of freeze protection. (c) The antifreeze fluid method—the cooling capacity of the closed cooling towers with different concentrations of glycol antifreeze fluid is numerically studied by analyzing the heat transfer coefficient ratio, the air volume ratio, the heat dissipation ratio, and the flow rate ratio. The addition of glycol will reduce the cooling capacity of the closed cooling tower.
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Grimaccia, Francesco, Alessandro Niccolai, Marco Mussetta y Giuseppe D’Alessandro. "ISO 50001 Data Driven Methods for Energy Efficiency Analysis of Thermal Power Plants". Applied Sciences 13, n.º 3 (20 de enero de 2023): 1368. http://dx.doi.org/10.3390/app13031368.
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This paper proposes an energy management system based on an Artificial Neural Network (ANN) to be integrated with the standard ISO 50001 and aims to describe the definition and the enhancement of the energy baselines by means of artificial intelligence techniques applied and tested on the real electrical absorption data of the auxiliary units of different thermal power plants in Italy. Power plant optimized operations are important both for cost and energy performance reasons with related effects on the environment in the next future energy transition scenario. The improvement of the energy baselines consists in determining more accurate consumption monitoring models that are able to track inefficiencies and absorption drifts through data analytics and Artificial Intelligence. Starting from the analysis of the energy vectors at the production site level, we performed a multi-scale analysis to define the consumption at macro areas level and finally find the most relevant consumption units within the plants. A comparison of different ANNs applied to several real power plant data was performed to model complex plant architecture and optimize energy savings with respect to pre-set thresholds according to the ISO 50001 standard procedure. The energy baselines are determined through the analysis of the data available in the power plants’ Distributed Control System (DCS), and we can identify the consumption derived from the unit’s proper operation. Based on the reported numerical simulations, improved baselines have been reached up to a 5% threshold for different plant sub-units, thus representing a relevant overall saving in terms of alert threshold definition and related control efficiency: a potential saving of about 140 MWh throughout the considered three-year dataset was obtained taking into account a cooling tower sub-unit, representing a considerable economic benefit. The results obtained highlight the neural technique efficiency in defining more accurate energy baselines and represents a valuable tool for large energy plant asset management to face relevant energy drifts observed in the last years of plant operation.
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Vinogradov, A. V. y O. N. Pushchak. "Application of electronic total stations for survey of metal towers designs of cellular communications". Geodesy and Cartography 922, n.º 4 (20 de mayo de 2017): 2–6. http://dx.doi.org/10.22389/0016-7126-2017-922-4-2-6.
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The availability and stability of cellular communication can be achieved with areas coverage by base stations. Base station cellular (metal tower) is a complex and massive engineering structure which is usually installed on different buildings. Weight of tower with equipment exceeds 1000 kg. For security purposes of objects with installed cellular base stations you need constantly determine the operating characteristics of towers. One of the important characteristics is the deviation of the tower from the vertical. In the regulations for the operation of towers various ways of determining the deviation of the tower from the vertical are discussed. In the instructions it is proposed to determine the deviation of the tower based on observations with three or four starting points, between which there must be mutual visibility. After all dimensions processing we will receive a deviation of the tower from the vertical. The paper proposes a more simple method of determining deviations of the tower from the vertical with the use of electronic total station. The software of the instrument will improve the quality of the work. Measurements are performed from one point in topocentric coordinates system. Independent observations from a different point improve accuracy and serve as a control. Error of the results does not exceed 5–7 mm.
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Alacam, Serkan y Asli Sencer. "Using Blockchain Technology to Foster Collaboration among Shippers and Carriers in the Trucking Industry: A Design Science Research Approach". Logistics 5, n.º 2 (9 de junio de 2021): 37. http://dx.doi.org/10.3390/logistics5020037.
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In the global trucking industry, vertical collaboration between shippers and carriers is attained by intermediaries, called brokers. Brokers organize carriers for a shipper in accordance with its quality and price requirements, and support carriers to collaborate horizontally by sharing a large distribution order from a shipper. Brokers also act as trustees, preventing the passing of private information of any party to the others. Despite these benefits, intermediaries in the trucking industry are involved in several sustainability problems, including high costs, high levels of carbon emissions, high percentages of empty miles, low-capacity utilizations, and driver shortages. Several studies have acknowledged the importance of improving collaboration to address these problems. Obviously, the major concern of brokers is not collaboration, but rather to optimize their own gains. This paper investigates the potential of blockchain technology to improve collaboration in the trucking industry, by eliminating brokers while preserving their responsibilities as organizers and trustees. This paper extends the transportation control tower concept from the logistics literature, and presents a system architecture for its implementation through smart contracts on a blockchain network. In the proposed system, the scalability and privacy of trucking operations are ensured through integration with privacy-preserving off-chain computation and storage solutions (running outside of the blockchain). The potential of this design artifact for fostering collaboration in the trucking industry was evaluated by both blockchain technology experts and trucking industry professionals.
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Yegelskaya, E. V., A. A. Korotkiy, E. A. Panfilova y A. A. Kinzhibalov. "Risk-based approach in “personnel-machinery-production environment” system at the facilities running tower cranes". Vestnik of Don State Technical University 19, n.º 1 (1 de abril de 2019): 56–62. http://dx.doi.org/10.23947/1992-5980-2019-19-1-56-62.
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Introduction. The paper discusses the applicability of a riskbased approach in the “personnel-machinery-production environment” system at the facilities running tower cranes through the introduction of IT-technologies that provide open communication of the staff, management team of the operating organizations, and the National Supervisory Authority, to reduce the accident rate. Materials and Methods. An example of a hazardous production facility running tower cranes is given. Materials on the analysis of operational status of tower cranes within the framework of the current legislation in the field of industrial safety are used. The necessity for innovations and transformations, one of whose methods is the risk-based approach allowing for the implementation of all required levels of control, is identified.Research Results. The stages of introduction of the riskoriented approach for tower crane operators implemented through IT-technologies using Web-applications on safety management under the tower crane operation based on the hazard analysis and risk assessment in gamut, algorithmically associated with the electronic block key of its local security system, are determined.Discussion and Conclusions. The application of a risk-based approach in the “personnel-machinery-production environment” system at the facilities running tower cranes through the introduction of IT-technologies will ensure the proper operation of all departments and each participant of the operation, as well as provide Supervisory bodies with an opportunity to access information on the operation for the implementation of control and supervision functions remotely.
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Papenfuss, Anne, Maik Friedrich, Christoph Möhlenbrink, Michael Rudolph, Sebastian Schier, Markus Schmidt y Norbert Fürstenau. "Assessing Operational Validity of Remote Tower Control in High-fidelity Tower Simulation". IFAC Proceedings Volumes 43, n.º 13 (2010): 117–22. http://dx.doi.org/10.3182/20100831-4-fr-2021.00022.
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Chang, Yung Chung, Kai Chun Peng y Ching Liang Chen. "Energy Analysis of Cooling Water Pump for Variable Loading in Air-Conditioning System". Applied Mechanics and Materials 421 (septiembre de 2013): 66–71. http://dx.doi.org/10.4028/www.scientific.net/amm.421.66.
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This study used linear regression analysis model to explore chilled water system of central air conditioning for energy saving of cooling water pump based on frequency conversion control of pumped. Research and analysis is divided two phases, the first phase is recording approach temperature and load rate (PLR; Partial Load Ratio) of cooling tower in variable frequency operational mode, then using linear regression analysis model to built the power consumption equation (KW/RT) of cooling water pump. Second phase will be to non-variable frequency operation modes to establish the same relationship equation, and then will be used the first phase record data that its wet bulb temperature and cooling towers PLR limits are in accordance with the second phase of the same range conditions, you can explore the power consumption difference of cooling water pump in variable frequency and non-variable frequency operational mode.Through this research and analysis, was informed that power consumption model error rate of less than 1%, also informed that variable frequency operational mode than non-variable frequency operational mode can save 782.8 kW (19.64%) in the quadratic regression analysis results. In three times regression analysis results can be saved 919.38 kW (22.3%). Accordingly, the present research findings and theoretical models can be used as cooling water pump energy saving, also can serve as the theoretical basis for other energy saving.
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Fontecha, Robert, Frank Kemper, Markus Feldmann, Stefan Witter y Ralf Schelenz. "Along-Wind Aerodynamic Damping of Wind Turbine Towers: Determination by Wind Tunnel Tests and Impact on Tower Lifetime". Energies 15, n.º 6 (9 de marzo de 2022): 1984. http://dx.doi.org/10.3390/en15061984.
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As wind turbines become larger and their towers more slender, aeroelastic effects play a bigger role in the wind turbine’s dynamic behavior. This study focuses on the along-wind aerodynamic damping of wind turbine towers, which has been determined by wind tunnel experiments using the forced oscillation method according to Steckley’s approach. Reynolds number scale effects have been considered through surface roughness modifications using sand paper and a dimple pattern, which have been described in detail. The wind tunnel measurements are performed in sub-critical, critical and trans-critical flow regimes, as well as in low- and high-turbulence conditions, which allows for an accurate description of the required relative roughness and Reynolds numbers for achieving trans-critical conditions. The resulting along-wind aerodynamic damping values according to Steckley’s and Holmes’ approaches are compared, and an analytical relation between them is established. Both approaches are then used in aeroelastic multi-body-simulations of an onshore 6 MW reference wind turbine and their impact on the wind turbine lifetime is evaluated through fatigue proofs at the tower base section. Holmes’ approach seems more appropriate for the application in aeroelastic multi-body simulations. A lifetime extension for the wind turbine tower of approximately 0.4% is achieved for the reference wind turbine tower, which roughly corresponds to 1 to 2 months for 20 years of operation. An analytical expression is given for the estimation of the tower’s aerodynamic damping in parked and operating conditions.
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Du, Xuan, Xian-Zhe Yu y Xing-Yu Yun. "Scenario modeling and operation path planning of autonomous driving tower cranes". Journal of Physics: Conference Series 2365, n.º 1 (1 de noviembre de 2022): 012020. http://dx.doi.org/10.1088/1742-6596/2365/1/012020.
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Abstract Combined with the operation specification of building tower cranes, the three-dimensional path planning technology of tower cranes and the optimization of path points are studied. The improved RRT-Connect algorithm is proposed. By introducing heuristic information in the path search, the path search efficiency and quality of the algorithm are improved. By eliminating invalid points in the path, the control burden of tower crane is reduced, and the optimized lifting point movement path is transformed into tower crane joint movement, and finally the calculation result is uploaded to PLC through LAN. The running trajectory of the tower crane lifting point is visually displayed in the scene model, and the validity and safety of the path are verified. The real tower crane is controlled. The operation is completed and the automatic driving of the tower crane is realized.
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Zhou, Mingduan, Zhengyang Lu, Jiaxing Wang, Chengsi Zhao Zhao y Yuan Zhao. "GNSS-Based High-Precision Fixed-Point and Lofting of Hoisting Operation for Construction Tower Crane". International Journal of Engineering and Technology 12, n.º 4 (noviembre de 2020): 48–53. http://dx.doi.org/10.7763/ijet.2020.v12.1183.
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GNSS receiver is one of novel sensors applied to accurate management and control technology for the construction tower crane. Since the low-precision of m-level navigation application based on GNSS pseudo-range observations, it is insatiable to develop requirements of intelligent command for the construction tower crane. To improve the monitoring accuracy for construction tower crane based on GNSS method, a high-precision monitoring approach applied to fixed-point and lofting of hoisting operation by GNSS carrier phase observations is proposed. It is applied to the intelligent command of hoisting operation for the construction tower crane, and a set of GNSS-based fixed-point and lofting of hoisting operation system, named as GNSS_PLS, is designed and developed. The experimental results show that, for 6 minutes (360 epochs) of the monitor station installed on the top of the construction tower crane, the minimum error of North-RMS is 0.009m, the maximum error of North-RMS is 0.015m and the average error of North-RMS is 0.013m; the minimum error of East-RMS is 0.008m, the maximum error of East-RMS is 0.014m and the average value of East-RMS is 0.011m; the minimum error of Up-RMS is 0.021m, the maximum error of Up-RMS is 0.036m and the average value of Up-RMS is 0.030m. The monitoring accuracy of intelligent command of the GNSS_PLS system is obtained to cm-level and the effectiveness and feasibility of the proposed solutions are verified.
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Tripathy, Sandip. "Challenges Faced By the Indian Transportation Sector in Implementing New Age Technologies". Psychology and Education Journal 57, n.º 9 (5 de enero de 2021): 6162–71. http://dx.doi.org/10.17762/pae.v57i9.2694.
Texto completoResumen
This research paper in its entirety tries to articulate the various types of challenges faced by the Indian Transportation Sector in implementing new age technologies for better control and visibility throughout the entire Supply Chain. It mostly focuses on the road and rail mode of transportation, though briefly it also touch-bases upon the water and air modes. Indian railways and roads position themselves as the third and second largest network respectively worldwide. In addition to a set of questionnaires circulated among individuals working in the logistics domain to capture their point of view, a thorough literature review of the previous works in this field was done to identify the causes – both external and internal to an organization, which affects implementation of digital solutions to present transportation problems. In this paper, we discuss along with others, two of the greatest challenges posed to the digital transformation – firstly, adamant attitude of traditional players operating in this space, who have for long, functioned through traditional processes and legacy systems and secondly, the complexity of the road and rail network running through the length and breadth of the country. Though the average time taken by enterprises to digitize their transportation business has reduced tremendously due to need of remote operations in these unprecedented times during COVID-19, but still there exist some of the challenges which need to be addressed. Some of the major drivers of identifying these challenges are the need to - reduce lead times by setting up a platform/control tower which can automate the management of transportation with minimized touch points between organizations and their customers, need to reduce risk of manipulated data by minimizing human intervention and need to increase customer satisfaction by incorporating functionalities like real-time tracking, automated exception handling and other. The challenges which were identified in this study can be further analysed to improve on it and conceptualize a framework for transforming Indian logistics (majorly the transportation space). This paper is written from the point of view of current scenario of Indian transportation industry.
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Ha, Ju-wan, Yu-jin Kim, Kyung-soon Park y Young-hak Song. "Energy Saving Evaluation with Low Liquid to Gas Ratio Operation in HVAC&R System". Energies 15, n.º 19 (5 de octubre de 2022): 7327. http://dx.doi.org/10.3390/en15197327.
Texto completoResumen
Previous studies have been conducted by employing various methods to reduce the condenser water temperature, a crucial control variable to consider when attempting to improve the operational efficiency of a chiller. The existing literature dealing with the effects of low-condenser water temperatures is limited, as the cooling water flow rate is often considered the operating variable of the condenser loop. However, to produce additional low condenser water temperatures, the approach temperature of the cooling tower in the system must be reduced. To reduce the approach temperature, it is necessary to review the physical behavior and efficiency of the cooling tower according to the change in the liquid to gas ratio (LGR), which is dependent upon the condenser water flow rate and the cooling tower fan air flow rate within the condenser loop. However, this process has rarely been reviewed in previous studies. Therefore, this study developed a new cooling tower control algorithm from the LGR perspective, and the operational effectiveness was quantitatively reviewed using EnergyPlus. Compared to the conventional conditions, when the cooling tower operation algorithm for low-approach temperatures was applied, the annual energy saving was 27.0%, the average chiller COP was improved by 27.8%, and the average system COP was improved by 47.4%. Furthermore, even when the algorithm was not applied at the same condenser water set temperature, the annual energy saving was 15%. The average COP of the chiller and COP of the system is improved by 2% and 23.2%, respectively. These results indicated that when a cooling tower is operated with a low LGR, even under the same outdoor air and load conditions, the cooling system’s efficiency can be improved with a change in the control algorithm without installing additional high-efficiency equipment.