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Ship-bridge collisions happen from time to time globally, and the consequences are often catastrophic. Therefore, this paper proposes a new high-pressure water jet interference (HPWJI) method for bridge pier protection against vessel collision. Unlike traditional methods that absorb energy by anti-collision devices to mitigate the impact force of ships on bridges, this method mainly changes the direction of ship movement by lateral high-pressure water jet impact, so that the ship deviates from the bridge piers and avoids collision. This paper takes China’s Shawan River as the background and simulates the navigation of a ship (weighing about 2000 t) in the HPWJI method in the ANSYS-FLUENT software. The simulation results show that the HPWJI method has a significant impact on the direction of the ship’s movement, enabling the ship to deviate from the pier, which is theoretically feasible for preventing bridge-ship collisions. The faster the ship’s speed, the smaller the lateral displacement and deflection angle of the ship during a certain displacement. When the ship speed is less than 7 m/s, the impact of water flow on the ship’s trajectory is more significant. Finally, this paper constructs a model formula for the relationship between the lateral displacement and speed, and surge displacement of the selected ship. This formula can be used to predict the minimum safe distance of the ship at different speeds. [ABSTRACT FROM AUTHOR] more...

The waves induced due to pile driving are investigated numerically, using the finite element method utilizing Plaxis-3D. Three locations are selected in Basra governorate-Iraq (Al-Fao, Shuaiba, and Umm Qasr), with various soil profiles, and different pile and hammer types to conduct the study. The predicted response in each site is compared to real measurements conducted (previously) by the authors. The regression analyses indicate excellent agreement between the predicted and measured variations of peak particle velocities with distance for various pile penetrations. It is proved that; the waveform of the impact hammer is a necessary input for a good simulation. The possible effects of pile driving operations on the environment, especially ground vibrations, are better understood according to this study. To reduce the negative influence on the local environment and buildings, it is essential to have this information to do comprehensive environmental impact assessments before building projects. It is realized that pile driving in soft soil deposits has negligible effects on shallow foundations of the nearby structures. For other profiles, the safe distance between the driven pile and an ordinary residential building is about (18) times the pile section's least dimension. This study contributes to our knowledge of pile-driving effects in various soil profiles, which in turn improves our capacity to simulate these effects, provides site-specific suggestions, and provides practical instructions for making construction projects safer and more sustainable. [ABSTRACT FROM AUTHOR] more...

To ensure the safety of hydrogen refueling stations (HRSs) and protective targets in the surrounding area, this paper has introduced a risk‐based safe distance assessment method for a 35MP HRSs, emphasizing the impact of the station's surrounding area. The findings indicate that the safe distance is determined by vapor cloud explosion (VCE) accident scenarios arising from pipeline leaks (compressor‐hydrogen storage tanks) at 125 m. Therefore, a crucial focus should be placed on safeguarding and maintaining hydrogen pipelines. Furthermore, based on societal risk, the requirement of a 358‐m safe distance specifies that the population gathering within this range should be <500 people, virtually eliminating the possibility of constructing hydrogen stations in urban residential areas. Only in scenarios where VCE risks are not considered, less‐populated surrounding environments might reduce the safe distance of hydrogen stations. Eliminating the risk scenarios of VCE is a crucial approach to lowering the safe distance of HRSs, making establishing such stations in urban centers feasible. Therefore, factors such as open spaces, well‐ventilated facilities, and blast walls become critical elements in reducing the safe distance of HRSs. [ABSTRACT FROM AUTHOR] more...

The blast-induced vibration during excavation by drilling and blasting method has an important impact on the surrounding structures. In particular, with the development of tunnel engineering, the impact of blasting vibration on tunnel construction has attracted extensive attention. In this paper, the propagation attenuation characteristics of blast-induced vibration (PPV, peak particle velocity) on different tunnel structures were systematically studied based on the field monitoring data. Initially, the attenuation characteristics of blasting vibration PPV on the lower bench surface, the side wall of the excavated tunnel and the closely spaced adjacent tunnel were investigated. Subsequently, the capacity of several widely utilized empirical prediction equations to estimate the PPV on tunnel structures was examined, along with a comparative analysis of their prediction accuracy. The research findings indicate that it is feasible to predict the PPV on the tunnel structures using empirical equations. The attenuation characteristics of blasting vibration PPV are different in different structures and directions. The prediction accuracy of the empirical equations varies, while the discrepancies are minimal. The principal variation among these equations lies in the site-specific coefficients k, β, λ, highlighting the differential impact of structural and directional considerations on the predictive efficacy. Based on the empirical equation and safe PPV provided by the blasting vibration safe standards on tunnels of China (GB6722-2014), and considering the influence of all structures and directions, it is determined that the safe distance of blasting vibration in the tested tunnel project should be larger than 20.28-18.31 m, 18.31-16.16 m, and 16.16-13.75 m for blasting vibration frequency located in ≤10 Hz, 10-50 Hz, and >50 Hz. [ABSTRACT FROM AUTHOR] more...

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

This article explores the teaching methodologies and theoretical frameworks pertinent to instructing novice car drivers in the applied geometry necessary for maintaining dynamic safe following distances. The study integrates principles from physics, geometry, and psychomotor abilities to provide a comprehensive understanding of the factors influencing safe driving practices. It explores the laws of motion, reaction times, and vehicle dynamics, alongside geometric relationships governing perceived distance and car size. The article also elucidates instructional strategies for novice drivers to develop critical thinking, psychomotor skills, and adaptive behaviours essential for safe distance maintenance. [ABSTRACT FROM AUTHOR] more...

This study takes the indoor substation adjacent to the elevated bridge subway line as the engineering background, investigates the structural vibration response law of the substation induced by the operation of the subway line through on-site vibration measurement, and proposes a novel nonlinear gas-spring quasi-zero stiffness isolator (NGS-QZSI) is proposed to reduce the structural vertical vibration and further reduce the safety distance. The software ABAQUS is used to establish a structure-equipment coupling numerical analysis model considering soil-structure interaction, and its effectiveness and accuracy are validated based on the measured results. The structural vibration response analysis is carried out under different vibration source distances, and a nonlinear gas-spring quasi-zero stiffness isolator is proposed to be employed for substation structural vibration isolation. The research results show that the substation structure under subway load excitation is dominated by vertical vibration, and its vibration response increases gradually with the increase of floor level. When the substation structure is less than 45 m from the subway line, the structural response exceeds the safety limit (12.5 µm/s) of the VC-C standard. With the vibration isolator attached, the structural vibration response is significantly reduced, with the peak and root mean square response controlled by more than 70 %. Particularly, the safe distance of the substation from the subway line is reduced from 45 m to 20 m. Moreover, the frequency domain result analysis indicates that the proposed nonlinear vibration isolator can effectively control the low-frequency vibration of the structure. [ABSTRACT FROM AUTHOR] more...

Neoadjuvant therapy has been widely employed in the treatment of rectal cancer, demonstrating its utility in reducing tumor volume, downstaging tumors, and improving patient prognosis. It has become the standard preoperative treatment modality for locally advanced rectal cancer. However, the efficacy of neoadjuvant therapy varies significantly among patients, with notable differences in tumor regression outcomes. In some cases, patients exhibit substantial tumor regression, even achieving pathological complete response. The assessment of tumor regression outcomes holds crucial significance for determining surgical approaches and establishing safe margins. Nonetheless, current research on tumor regression patterns remains limited, and there is considerable controversy surrounding the determination of a safe margin after neoadjuvant therapy. In light of these factors, this study aims to summarize the primary patterns of tumor regression observed following neoadjuvant therapy for rectal cancer, categorizing them into three types: tumor shrinkage, tumor fragmentation, and mucinous lake formation. Furthermore, a comparison will be made between gross and microscopic tumor regression, highlighting the asynchronous nature of regression in the two contexts. Additionally, this study will analyze the safety of non-surgical treatment in patients who achieve complete clinical response, elucidating the necessity of surgical intervention. Lastly, the study will investigate the optimal range for safe surgical resection margins and explore the concept of a safe margin distance post-neoadjuvant therapy. [ABSTRACT FROM AUTHOR] more...

This article explores the teaching methodologies and theoretical frameworks pertinent to instructing novice car drivers in the applied geometry necessary for maintaining dynamic safe following distances. The study integrates principles from physics, geometry, and psychomotor abilities to provide a comprehensive understanding of the factors influencing safe driving practices. It explores the laws of motion, reaction times, and vehicle dynamics, alongside geometric relationships governing perceived distance and car size. The article also elucidates instructional strategies for novice drivers to develop critical thinking, psychomotor skills, and adaptive behaviours essential for safe distance maintenance. more...

This paper provides an analysis of the values of safety distance between the two moving vehicles, based on the parameters of the behaviour of young drivers. The main objective of this research was to determine the driver's response time for braking manoeuvre (BRT) in car-following situations. The test results were used to verify certain recommendations for the vehicle driving parameters, the principles of driver's performance to increase road traffic safety, etc. The driver's response times, determined during the testing in the simulator, were used to assess the recommended values of the safe following distance under different road conditions and various ways of driver behaviour. In the paper, for different values of BRT a safety distance in emergency traffic situations was determined. [ABSTRACT FROM AUTHOR] more...

Objective: To evaluate the accuracy of the Advanced Pediatric Life Support (APLS) endotracheal tube (ET) depth formula in Indian children aged 1 to 12 years. Methods: We enrolled 86 children aged 1–12 years requiring intubation and ventilation. The ET depth was determined using the APLS formula, and chest X-rays were utilized to evaluate 'appropriate ET depth (accuracy)' based on 'vertebral level criteria' and 'safe distance between ET tip and carina.' Results: Out of 86 cases, none had bronchial intubation. An accuracy of 37.2% (32 cases) was observed, with 57% (49 cases) showing deep placement. Among deep placements, 11 met 'vertebral level criteria' but not 'safe distance criteria.' Redefining deep placement based solely on 'safe distance criteria,' resulted in 50% accuracy. Conclusion: APLS formula effectively prevents bronchial intubation in Indian children, but tends to overestimate ET depth (50% cases) when considering the 'safe distance between ET tip and carina.' [ABSTRACT FROM AUTHOR] more...

This research is aimed to substantiate the optimally safe direction for mining operations developing in the conditions of shear processes under hydrostatic pressure influence when mining the Zavalivskyi Graphite Deposit. Using a graphical–analytical method, the slope stability index of the Pivdenno–Skhidnyi open-pit walls in the Zavalivskyi deposit and the safe distance for placing mining equipment have been determined. This method involves constructing a calculation scheme for each studied open-pit wall area based on the determined parameters by algebraically adding forces along a curvilinear shear surface, taking into account hydrostatic pressure within a possible collapse prism. During the research, factors have been identified that influence the optimal direction for stripping and mining operations developing under conditions of shear processes caused by flooding of lower horizons at the Zavalivskyi Graphite Plant. It has been revealed that the determining factor when choosing the direction for the development of mining operations is the safety factor of the open-pit working wall, ranging from 0.9 to 2.71 in the studied areas. Moreover, according to current normative documents, this indicator should not be less than 1.3. It has been determined that a promising direction for the development of mining operations in the Pivdenno–Skhidnyi open-pit mine is its south-western, western, and north-eastern areas, with a length of 556 m and a safe size for placing mining equipment of 27.12–32.54 m. Recommendations and measures for conducting mining operations have been developed to ensure the stable condition of the open-pit walls. [ABSTRACT FROM AUTHOR] more...

The safe distance is an important reference for the mutual avoidance and interference reduction between the pipelines and HVDC electrodes in the planning stage. However, the definition of pipe-to-electrode safe distance in existing standards and researches is still not clear yet. In order to study the reasonable value of safe distance, firstly, the influencing factors of safe distance is analyze through simulation. Soil structure, pipeline length, coating surface resistivity and grounding current are the main factors while electrode type and pipe size are the minor ones. Then, taking touch voltage and DC corrosion rate as the limit respectively, the pipe-to-electrode safe distance is analyzed under different parameter combinations. When touch voltage is taken as the limit, the safe distance to meet the 70V limit is 11km~25km ( $I=3000\text{A}$ ) and 16km~52km ( $I=6000\text{A}$ ); The safe distance to meet the 35V limit is 16km~52km ( $I=3000\text{A}$ ) and 24km~87km (I=6000A). When DC corrosion is taken as the limit, the safe distance to meet the 0.1mm/a limit is 14km~38km ( $I=3000\text{A}$ ) and 20km~56km ( $I=6000\text{A}$ ); The safe distance to meet the 0.0254mm/a limit is 32km~65km ( $I=3000\text{A}$ ) and 44km~70km ( $I=6000\text{A}$ ); The safe distance to meet the 0.01mm/a limit is 44km~70km ( $I=3000\text{A}$ ) and 52km~72km ( $I=6000\text{A}$ ).In order to solve the problems of unknown parameters, uncertain limit standards, and too-large safe distance, the acceptable safe distance is further extracted. The indicator $\kappa =0.8$ is suggested. The acceptable safe distance of 100km short pipeline is 13km ( $I=3000\text{A}$ ), 19km ( $I=6000\text{A}$ ) while that of 700km short pipeline is 25km ( $I=3000\text{A}$ ), 27km ( $I=6000\text{A}$ ). For the case where the grounding current and pipeline length are also unknown, it is recommended to take the acceptable safe distance of 30km. In addition, the safe distance or acceptable safe distance of long pipelines can be valued according to that of the short ones after segmentation. The acceptable safe distance of 100km short pipelines is 18km. more...

OBJECTIVE: The objective of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI) in neurovascular bundle injury during total hip arthroplasty. PATIENTS AND METHODS: The magnetic resonance imaging (MRI) examinations of the hip joints of 429 patients were reviewed. The distances on the left and right sides were measured and recorded using small, hydrophilic gadolinium (III)-based chelates as contrast agents. The data were analyzed and handled using Statistical Product and Service Solutions (SPSS). RESULTS: The results showed that each measured distance in males was longer than in females, on both right and left sides (p<0.001). The coefficient of determination (R2 ) of the influencing factors on the three distances was found to be 0.162, 0.038, and 0.104, respectively, in multiple linear regressions. The results of the Pearson’s correlation coefficient also suggested that there was a significant correlation (p<0.05). CONCLUSIONS: This study demonstrates that MRI can be a valuable diagnostic tool for neurovascular bundle injury during total hip arthroplasty. The gender difference in the measured distances indicates that sex should be considered when interpreting MRI findings. [ABSTRACT FROM AUTHOR] more...

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Copyright of Journal of Zhengzhou University: Engineering Science is the property of Editorial Office of Journal of Zhengzhou University: Engineering Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

In normal car-following (CF) states, the minimum safe braking distance (MSBD) is virtually an unmeasurable variable, mainly due to the diversity of drivers' reaction times and vehicles' braking performance. The average MSBD regarding the reaction time and decelerations as constant values is sometimes greater than the distance used for safe braking of the following vehicle when the leading vehicle applies an emergency brake, which is named the short-distance CF behavior. The short-distance CF conveys that drivers adopt strategies of lower acceptable safety levels, which can be applied to intelligent connected technology (ICT). The objective of this paper was to extend the CF model to accommodate manual driving behavior on the state of different safety levels, and to analyze road traffic flow in the environment from manual driving to high-level intelligent driving with different delays. First, the cognitive bias variable was defined as the ratio of the actual braking distance available to the average MSBD to indirectly analyze different safety levels. Second, the Gipps model was extended, depending on the cognitive bias variable threshold and the duration length of the short-distance CF state, to reproduce driving behaviors with different acceptable safety levels more accurately by numerical simulation. Finally, using models to numerically simulate the impact of vehicles on road traffic flow was carried out. CF behaviors with lower acceptable safety levels under manual driving conditions increase traffic efficiency, and road capacity and safety are significantly improved due to ICT enabling a shortened reaction time. The short-distance driving applied to ICT is expected to be a strategy for traffic congestion mitigation. [ABSTRACT FROM AUTHOR] more...

We aimed to research the design and path-planning methods of an intelligent disinfection-vehicle system. A ROS (robot operating system) system was utilized as the control platform, and SLAM (simultaneous localization and mapping) technology was used to establish an indoor scene map. On this basis, a new path-planning method combining the A* algorithm and the Floyd algorithm is proposed to ensure the safety, efficiency, and stability of the path. Simulation results show that with the average shortest distance between obstacles and paths of 0.463, this algorithm reduces the average numbers of redundant nodes and turns in the path by 70.43% and 31.1%, respectively, compared to the traditional A* algorithm. The algorithm has superior performance in terms of safety distance, path length, and redundant nodes and turns. Additionally, a mask recognition and pedestrian detection algorithm is utilized to ensure public safety. The results of the study indicate that the method has satisfactory performance. The intelligent disinfection-vehicle system operates stably, meets the indoor mapping requirements, and can recognize pedestrians and masks. [ABSTRACT FROM AUTHOR] more...

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

In this article, the authors consider the issues of road infrastructure and their impact on road safety. The road network affects the risk of road accidents because it determines how road users perceive the environment. The basis for comparing a number of events in a traffic accident with categories of factors contributing to the accident. Purpose – the measures and methods by which it is possible to achieve a safe level of roads are defined. Methodology: the article used a full-scale experiment, statistical analysis, risk theory. Results: the factors that increase road safety, provide a comfortable environment for drivers and pedestrians, and reduce the cost of repair and construction of highways are identified. Practical implications: identification of the most effective and priority measures to improve highways in order to ensure safety and a comfortable environment. Research activities on the development of new approaches in the field of traffic management. more...

When the metal structures distributed in the underground roadway are in the near-field of the large loop transmitting antenna, they will couple the electromagnetic wave energy of the large loop transmitting antenna. Once the metal structure has a breakpoint and friction occurs, it may produce friction discharge spark and ignite gas. This poses a threat to the safety of coal mine. In order to solve this problem, the safety of electromagnetic wave energy of underground metal structure near-field coupled large loop transmitting antenna is analyzed from two aspects of near-field coupling risk coefficient and safe distance. By establishing the equivalent circuit of electromagnetic wave energy of metal structure near-field coupled large loop transmitting antenna, the expressions of near-field coupling risk coefficient and safe distance between metal structure and large loop transmitting antenna are derived. The influence of the radius of the large loop transmitting antenna, the radius of the equivalent receiving coil of the metal structure, the friction discharge spark load and the distance between the metal structure and the large loop transmitting antenna on the near-field coupling risk coefficient and the safe distance are analyzed. The simulation results show that the near-field coupling risk coefficient increases slightly at first and then decreases slightly or increases all the time with the increase of the radius of the large loop transmitting antenna. Under certain conditions, the friction discharge spark load can make the near-field coupling risk coefficient reach the peak value. When the radius of the large loop transmitting antenna is greater than or equal to the radius of the equivalent receiving coil of the metal structure, the near-field coupling risk coefficient at the peak value may exceed the critical value 0.46 of the near-field coupling risk coefficient. This may cause danger. When the radius of the large loop transmitting antenna is smaller than the radius of equivalent receiving coil of the metal structure, the near-field coupling risk coefficient at the peak value is less than the critical value 0.46 in most cases. This will not cause danger in most cases. Under certain conditions, the radius of the large loop transmitting antenna can make the near-field coupling risk coefficient reach the peak value. The near-field coupling risk coefficient at the peak value first increases and then decreases with the increase of the radius of equivalent receiving coil of the metal structure. It is more likely to exceed the critical value 0.46 of the near-field coupling risk coefficient, which is likely to cause danger in the gas environment. The safe distance increases with the increase of the radius of the large loop transmitting antenna. The safety of the electromagnetic wave energy on the friction discharge spark load decreases with the increase of the radius of the large loop transmitting antenna. When the radius of the large loop transmitting antenna is greater than or equal to the radius of the equivalent receiving coil of the metal structure, the safe distance increases with the increase of the radius of the equivalent receiving coil of the metal structure. The safety of the electromagnetic wave energy on the friction discharge spark load decreases with the increase of the radius of the equivalent receiving coil of the metal structure. When the radius of the large loop transmitting antenna is smaller than the radius of the equivalent receiving coil of the metal structure, the safe distance first increases slowly and then decreases with the increase of the radius of the equivalent receiving coil of the metal structure. The safety of the electromagnetic wave energy on the friction discharge spark load first decreases and then increases with the increase of the radius of the equivalent receiving coil of the metal structure. more...

Background: Over time, surgical management for conditions involving the long head of the biceps tendon (LHBT) has evolved. Some techniques, such as keyhole tenodesis proposes bicortical drilling, however, carries an axillary nerve injury risk. The goal of our cadaveric study was to see if we could keep a safe zone between the point of exit of keyhole tenodesis of biceps and axillary nerve. Methodology: The study was performed on ten shoulders from five fresh frozen cadavers. Between the lower border of the transverse humeral ligament (THL) and the superior margin of the pectoralis major insertion at the lowest limit of the bicipital groove, a beath pin was driven through with the help of the modified tip aimer tibial jig procured from the anterior cruciate ligament reconstruction (ACL) set, which was fixed at an arc of 45°. The distance between the axillary nerve and beath pin at the exit point was measured. Results: The biceps tendon musculotendinous junction was followed all the way to the inferiorly and biceps tendon was found in the groove. The average distance from the axillary nerve to the exit point of the beath pin was 17.7 mm (range 14.4–20.9 mm, 95% CI). Conclusion: The axillary nerve is not injured during bicortical drilling when keyhole tenodesis of biceps is performed at the distal limit of the groove of biceps. The area in the biciptal groove between inferior margin of THL and superior border of pectoralis major insertion is safe area for biceps tenodesis. [ABSTRACT FROM AUTHOR] more...

Sadov's formula is widely used to solve the seismic wave velocity problem of single-hole blasting in calculations in blasting engineering. There is a significant difference between the calculated results for group-hole blasting and the actual situation in an open-pit mine. The modification and application of Sadov's formula for group-hole blasting in open-pit mines is discussed in this paper. First, the insufficiencies of Sadov's formula under the condition of group-hole blasting in an open-pit mine are analyzed. A theoretical derivation method for modifying the maximum charge coefficient is proposed. Second, blasting vibration data of the Hejing limestone mine of Guangxi Huarun Cement (Pingnan) Co. Ltd., obtained by onsite monitoring, are analyzed. The vibration data of the single-hole blasting are processed by linear superposition and fitting. The difference between the superposition results of the same single-hole vibration signal and different single-hole vibration signals and the onsite monitoring data is compared and analyzed. A modified expression of Sadov's formula is obtained. The onsite blasting parameters of the group-hole blasting are verified. Finally, the safety distance problem of the grouting curtain in blasting construction is solved using the modified Sadov's formula. The results show that the modification scheme of maximum charge Q in Sadov's formula is determined through theoretical analysis and formula derivation. The peak vibration velocity of the group hole blasting suitable for the Pingnan mining area is deduced, and the correctness of the peak vibration velocity is verified. [ABSTRACT FROM AUTHOR] more...

The paper presents the design and development of a short range motion detector based droid. In this digital and automotive day and age, robotics, and IoT produce an impact on human life. One can't just rely on the traditional mode of work in this era. One has to adapt the robotics and keep digging in it, as it's the near future for humans. So to do this there are many aspects to implement automotive in day-to-day life. One such event is to study a robot that follows humans that means which can detect human movement and react as per this movement. The study shows that there are many researchers, scientists, engineers who have worked and still working to improve this human movement detection in robotics. This paper has studied some of the previous work and gave a comparative analysis of the same. The work presented in this paper is the mini-project work of the under-graduate students of the engineering college guided by their supervisors. [ABSTRACT FROM AUTHOR] more...

With the continuous increase of offshore wind farms and other offshore regional buildings, the contradiction between them and the navigation safety in the densely distributed areas of offshore ship tracks is increasingly obvious. It is urgent to build a safe distance model based on the actual sea condition to reduce the mutual influence. Based on the drift distance of ships in the boundary water areas of the wind farm under the actual meteorological and hydrological conditions, as well as the tolerable collision probability, reliability model and the normal distribution trend of ships in the ship routes, and the probability model of safe distance between ship routes and wind farm is built in the end. Based on the example and the tolerable collision probability of ships, the safe distance is analyzed, the analysis results show that the calculation model can determine the safe distance according to the control requirements of the collision probability between the ship and the offshore wind farm. In addition, the collision probability and the safe distance obtained are basically consistent with the safe distance published by the local maritime authority in combination with the changes of the output results caused by the velocity difference of the ship. The model lays a theoretical foundation on offshore wind farm site selection optimization, route boundary demarcation, ship safety and maritime supervision. more...

The electromagnetic environment around high voltage transmission lines is one of the important factors affecting the planning and construction of transmission lines. According to the planning of Jinggangshan 220 kV hydropower plant, the two-dimensional electromagnetic field simulation model of 220 kV line and 220 kV and 500 kV line parallel sections was established to calculate the distribution of electromagnetic field and analyze the influence of electromagnetic environment on the surrounding residential housing. According to the electromagnetic field standard limit requirements, the height limit of buildings below the line was determined. According to the calculation results of the electric field in the parallel section, the distance between the lines in the parallel section was determined by considering the influence of wind deviation. The calculation method proposed can provide a reference for the electromagnetic environment analysis of transmission lines, and the calculation results provide a strong theoretical support for the planning and design of practical projects. [ABSTRACT FROM AUTHOR] more...

With the rapid development of automobile and transportation industry, intelligent transportation has made great progress, especially in the field of automatic driving. In order to study the operation characteristics of single lane traffic flow when manual driving, ACC and CACC vehicles exist independently, Gipps safety distance and speed were introduced to build car-following models respectively, based on the NaSch rule of cellular automaton. Through numerical simulation experiments, the impact of mixing ACC and CACC vehicles on road capacity, driving speed, following space gap, traffic congestion and other operation characteristics were analyzed. The research shows that the road capacity and vehicles’ speed improve continuously, with the increase of ACC and CACC vehicles penetration rates. When the traffic flow is composed of an equal number of ACC and CACC vehicles, the road capacity can be increased by 2.2 times, the congestion index can be reduced by 60%, and the traffic operation can be significantly improved. The introduction of ACC and CACC vehicles increases the following space gap when driving manually, while ACC and CACC vehicles can still follow the front vehicle at a high speed and with a small space gap, which improves the utilization of road space resources. [ABSTRACT FROM AUTHOR] more...

Intelligent agricultural vehicles have been widely used in the process of farming and harvesting in the field, which has brought great convenience to agricultural production. However, there are also safety issues such as accidental collision of agricultural vehicles or other agricultural machinery during operation. The use of sensing technology for the timely and accurate detection and pre-warning of obstacles during the operation of agricultural machinery is critically important for ensuring safety. In this paper, a two-dimensional Lidar is used to detect obstacles in front of tractors with the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm and the Minimum Cost Maximum Flow algorithm (MCMF). A method to judge whether the obstacle is static or dynamic and a classification model of different security warning levels for obstacles in different states is proposed. Actual vehicle tests were conducted, with static obstacles tested repeatedly, and dynamic obstacles tested at different directions and speeds. The results showed that the overall average warning accuracy rate is 90.5%. Prediction results were robust for obstacles in different states, indicating that this system is able to ensure the safety of agricultural vehicles during their operation and promoted the development of agricultural mechanization. [ABSTRACT FROM AUTHOR] more...

Lately, explosions with a large TNT equivalent have occurred with alarming frequency causing severe structural damage. The damage suffered by these structures has been exacerbated by the ground shock generated during these large equivalent explosions. The aim of this work is to study the ground-shock propagation behaviors, the areas affected by them, and determine the minimum safe distance for various structures. To measure ground shock data at different distances from the epicenter of the blast, actual 1 t and 10 t TNT surface explosion experiments were performed. The velocity and attenuation coefficient of the ground shock generated by the 1 t TNT surface explosion were determined, and the empirical equations provided by the UFC 3-340-01 standard were validated. Additionally, numerical analyses were performed to analyze the effects of ground shocks on buildings around an explosion. The maximum particle vibration velocities and attenuation behaviors of a 10 t TNT surface explosion as well as the minimum safe distances for a variety of structures were obtained from the numerical analyses. [ABSTRACT FROM AUTHOR] more...

Cranes are widely deployed for lifting and moving heavy objects in dynamic environments with human coexistence. Suddenly appeared workers, vehicles, and robots can affect the safety of the cranes. To avoid possible collisions, the cranes must have prediction ability to know how dangerous the situation is. In this paper, we address the safety issues of bridge cranes based on its online physical states and control model. Due to the swing of the payload, the safe braking distance cannot be a constant value. Therefore, we here propose a model prediction control (MPC)‐based anti‐swing method for non‐zero initial states, where a new reference trajectory and a new cost function for optimization are proposed, such that the proposed MPC method can control the crane to follow the proposed reference trajectory and achieve a stable stop state with anti‐swing. Furthermore, an offline learning mechanism is introduced to learn a statistical model between the velocity of the crane and the safe braking distance achieved by using the proposed MPC braking control method. In this way, we can predict how far the crane would require to safely stop without swing based on its current velocity, which is the safe distance prediction to evaluate the dangerous level of the dynamic obstacle. Experiments using both a simulated crane and a real crane demonstrate that the proposed safe braking distance prediction method is effective for safe braking control of the bridge cranes. [ABSTRACT FROM AUTHOR] more...

In order to enhance the safety management of high consequence areas (HCAs) of oil and gas pipelines and effectively control the safety risk of personnel intensive HCAs, an investigation was performed for the causes of HCAs, the typical accident cases and the influence scope of consequence in personnel intensive HCAs were analyzed, and comparison was made to the identification criteria of HCAs at home and abroad. According to the statistics of the current situation of the personnel intensive HCAs of the existing and new pipelines in China, there are 1 523 and 517 personnel intensive HCAs for every 1×104 km existing oil and gas pipelines, respectively, and the pipeline section in the personnel intensive HCAs accounts for about 18% of the total length of the new oil and gas pipelines. In this study, the two main reasons for the continuous formation of the HCAS were analyzed, including lack of optimization for new pipeline routing and effective control of land using around the existing pipeline, and the whole process management system of the HCAs was put forward, including prevention before planning, assessment during planning and control after formation. Further, suggestions were proposed from the aspects of formulating the land division method and control requirements around the oil and gas pipelines, defining the safe distance of oil and gas pipelines and promoting the construction of urban pipeline corridor. more...

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

To study the regularity of blasting vibration of semi coal and rock roadway and its influence on the broken rock zone, the semi coal and rock roadway of Xinyi Coal Mine is taken as the test site, and the field test of blasting vibration and broken rock zone is carried out. The monitoring data analysis of blasting vibration shows that the main vibration frequency of excavation blasting in semi coal and rock roadway is 50 Hz to 250 Hz, and the main frequency of blasting vibration is higher when the detonating charge of the same section of detonator tube is large. The measured blasting vibration velocity is higher than the theoretical value, and the blasting vibration attenuation formula is fitted by using Sadov’s formula regression, then the permissible safe distance of blasting in different rock layers is calculated. The analysis of the test data of the broken rock zone shows that the range of the broken rock zone of sandstone layer surrounding rock is 1 m to 1.25 m, and the range of coal seam surrounding rock is 1.25 m to 1.5 m. The blasting vibration has little disturbance to the surrounding rock of sandstone layer, and the broken rock zone of coal seam increases by about 0.2 m. With the increase of free surface, the propagation of total explosion energy in rock mass decreases, and the disturbance to surrounding rock by blasting vibration becomes smaller. Based on the results of monitoring and analysis, the improvement measures of charging structure and supporting parameters are put forward. more...

Polusi udara yang keluar dan menyebar dari cerobong asap industri dapat menimbulkan berbagai macam penyakit bagi masyarakat. Jangkauan penyebaran polusi udara yang bervariasi dan bergantung pada berbagai faktor seperti kecepatan dan arah angin, ketinggian cerobong, dan konsentrasi polutan perlu mendapat perhatian agar tidak menimbulkan dampak negatif pada masyarakat di suatu pemukiman. Oleh karena itu, dalam penelitian ini model Gaussian plume digunakan untuk menentukan pola penyebaran polusi udara dan konsentrasinya. Polutan yang diamati adalah SO2, NO2, dan CO2 dengan konsentrasi yang berbeda dan memperhatikan dua nilai kecepatan angin serta intensitas cahaya matahari. Dengan mengikuti solusi model Gaussian Plume yang diperoleh dengan transformasi Laplace dapat ditentukan jarak aman pemukiman dari cerobong asap industri. Lebih lanjut, kondisi stabilitas atmosfer juga mempengaruhi besarnya nilai konsentrasi maksimum. Semakin stabil kondisi atmosfer mengakibatkan konsentrasi maksimal pada masing-masing polutan menurun dan semakin jauh polutan mencapai titik maksimum dari cerobong asap. more...

The rapid impact compaction technology is often used in the backfill compaction work for road subgrade, box culvert, and pipeline. There are few cases of compaction treatment for large-scale backfill construction work. At present, there are just a few analyses and researches on its vibration impact in the industry, and there is a lack of similar data and test cases. Taking the main reclamation works of Hong Kong International Airport three runway system project as an example, the construction vibration parameters of the technology were obtained through field tests. Based on the analysis of the tests data, it is concluded that under the condition that the compaction energy is no more than 84 kJ, the construction spacing is no less than 1.25 m, and there is no influence on the conventional monitoring instruments (MPX and GPS), and the safe distance to the temporary buildings is about 15 m. [ABSTRACT FROM AUTHOR] more...

In present paper, we consider the impact of blast-induced vibrations on constructions by analyzing the blasting results at limestone quarry Hardovac near Doboj (Bosnia & Herzegovina) recorded in period 2012–2015. Analysis is conducted using the multiple linear regression (MLR) and artificial neural networks (ANN) for establishing the correlation between the peak particle velocity, vibration frequency and several controlling factors (number of boreholes and their average depth, distances between the boreholes, between the arrays of boreholes and between the blasting and recording point, total and immediately detonated amount of explosive). As a result, we formulate explicit nonlinear models for estimation of safe distance between blasting points and different neighboring structures, including the construction of safe distance isolines. Suggested approach provides results which are comparable to the commonly used techniques but indicate the important effect of the examined controlling factors on safe distance, which is usually underestimated in common practice. [ABSTRACT FROM AUTHOR] more...

Aluminium powder has a very high risk of explosion. To clarify the disastrous effects of the overpressure and high temperatures during an aluminium powder explosion in a constrained space and the distribution of the outdoor safe distance, the explosion and venting processes of aluminium dust in a large-scale building were investigated under different venting coefficients, K v (K v = A v / A p), using computational fluid dynamics (CFD). The results show that although an increase in the venting coefficient can reduce the indoor overpressure and explosion temperature, it can also increase the distance up to which the outdoor overpressure and high temperature can cause damage. Moreover, the distance up to which explosion overpressures can be harmful to personnel and buildings increases with an increase in the venting coefficient. Hence, the safe outdoor distance may be more than 1.5–2 times the fire safe distance listed in the Chinese Code for fire protection design of buildings. The high-temperature damage caused by the explosion also increases with an increase in the venting coefficient. Therefore, the current explosion safety protection distances for aluminium powder production sites need to be revised. [ABSTRACT FROM AUTHOR] more...

The situation of monotonous and high speed in highway will increase the risk of accidents. Drivers need to adjust the vehicle speed for safe-distance maintain. A device that can help drivers set a safe distance with the vehicle in front is known as adaptive cruise control (ACC). The ACC is a subsystem of advanced driver assistance systems (ADASs) that serves to assist the driver during cruise driving. This study presents the hardware simulation of camera-based ACC. Fuzzy logic is used to get smoother experimental car movements so that it is like a real vehicle. The results from hardware simulation show that camera-based ACC simulation and the fuzzy logic control can work according to the design. The results of ACC testing with a constant leading-vehicle speed have a success rate of 75%, while testing with a changing leading-vehicle speed has a success percentage of 60%. [ABSTRACT FROM AUTHOR] more...

The paper gives the results of measuring the characteristics of ultraviolet radiation in UV-C range at consumable electrode mechanized welding in a mixture of shielding gases. These studies were the base for issuing recommendations on protection of welders and auxiliary personnel, as well as personnel not performing welding operations directly. Recorded values of the intensity of radiation, reflected from the welding booth walls (0.03…0.17 W/m2), exceed the TLV of 0.001 W/m2, specified in SN 4557-88. Therefore, when working in a welding booth, it is necessary to take additional measures for protection of the back of the head and neck from exposure to reflected radiation. 8 Ref., 3 Tabl., 1 Fig. [ABSTRACT FROM AUTHOR] more...

In this paper, a test method of the forward collision warning (FCW) function is proposed and the forward collision risk factor is defined. Firstly, the concept of the minimum alarm distance is given according to the road scene and vehicle movement state, and then the calculation equation of the minimum alarm distance is derived by combining kinematics equation and driver's response time. We compare the actual vehicle distance and the minimum alarm distance to determine whether the FCW test is successful. The actual vehicle distance and the minimum alarm distance are used as the parameters to derive the calculation method of the vehicle's FCW risk factor. Finally, the test scenario is deployed in simulation software, and multiple test cases of FCW are established. By observing the simulation process and analyzing the experimental data, we found that the motion rule of the tested vehicle conforms to our theoretical analysis, and the experimental result is similar to the predicted result, so the conclusion is drawn: The FCW test method based on minimum alarm distance has confidence. At the same time, we conduct a comparative experiment on the hazard factor. The hazard factor we propose is applicable to more automatic driving conditions, and can be continuously output in the test process, which is more conducive to analysis. more...