Occurrence Of Bursts Research Articles

Improved two-dimensional dynamic S-EMG Signal compression with robust automatic segmentation

This work presents an automatic and robust algorithm for surface electromyography signals segmentation in dynamic experimental protocol. The signals are segmented based on the peak burst occurrence. The two-dimensional array is constructed and used as input of a 2D signal encoder. The two-dimensional matrix lines may be long enough to have several bursts. The algorithm includes, besides segmentation modules, several others to eliminate the occurrence of false positives. An encoder that combines the AV1 and JPEG2000 toolset is used to compress data. Basically, depending on the target compression rate the encoder uses AV1 or JPEG2000. Examples of segmentation for electromyography signals digitalized from lower and upper limbs are shown. Data compression results for real electromyography signals data bank are presented. A performance comparison with other works reported in the literature is also included.

Prediction and Assessment of Rock Burst Using Various Meta-heuristic Approaches

One of the utmost severe mining catastrophes in underground hard rock mines is rock burst phenomena. It can lead to damage to mine openings and equipment as well as trigger accidents or even threat to life as well. Due to this, a number of researchers are forced to study some easy-to-use alternative methods to predict the rock burst occurrence. Nevertheless, due to the extremely multifaceted relation between mechanical, geological and geometric factors of the mines, the conventional prediction methods are not able to produce accurate results. With the expansion of machine learning methods, a revolution in the rock burst occurrence has become imaginable. In present study, three machine learning methods, namely XGBoost, decision tree and support vector machine, are utilized to predict the occurrence of rock burst in various underground projects. A total of 134 rock burst events were gathered together from various published literatures comprising maximum tangential stress (MTS), elastic energy index (EEI), uniaxial compressive strength and uniaxial tensile stress (UTS) that have been used to develop various machine learning models. The performance of machine learning methods is evaluated based on the accuracy, sensitivity and specificity of the rock burst prediction.

The Population of H ii Regions in NGC 7020

Abstract The galaxy NGC 7020 displays an exotic hexagonal ringlike central structure with conspicuous ansae located at two opposite vertices and a tenuous external ring populated by H ii regions. Inside and around the hexagonal structure, Hα emission is also present at the inner disk. To characterize the population of the H ii regions, as well as their ionizing clusters, we imaged NGC 7020 with narrowband Hα and nearby continuum filters attached to GMOS-S installed on the Gemini South telescope. We found 202 H ii regions or complexes of H ii regions evenly distributed between the outer ring and the central disk The nucleus and ansae also present Hα emission. The equivalent width of the Hα line (W Hα ) is systematically greater at the regions of the outer ring relative to those of the inner disk. We discuss the influence of the metallicity gradient of the disk and the upper limit of the masses of the initial mass function on W Hα , and we conclude that the data are still consistent with the occurrence of a younger burst of H ii region formation in the outer ring. The central regions present more massive clusters, M ≥ 106 M ⊙, than those of the outer ring (M ≤ 106 M ⊙). Three clusters within 5″ of the nucleus present masses higher than 108 M ⊙. The presence of diffuse Hα emission in the inner 5″ suggests gas flows in the nuclear region.

Differences of Mechanical Parameters and Rockburst Tendency Indices between Coal and Non-Coal Rocks and Modified Rockburst Tendency Classification Criteria for Non-Coal Rocks

Rockbursts represent hazardous dynamic disasters for underground coal mines and other underground rock engineering projects. Some bursting liability indices are put forward and applied to identify the likelihood of rock burst occurrence. The classification criteria of the bursting liability indices are proved to be reasonable for coals, but they are still immature for non-coal rocks. Thus, it is uncertain that it is reasonable to use the classification criteria of coal for evaluating the bursting liability of non-coal rocks. Hence, in this study, a large amount of data, such as the basic mechanical parameters, i.e., Poisson’s ratio μ, elastic modulus E, uniaxial compressive strength σc, and uniaxial tensile strength σt, and the bursting liability indices, i.e., elastic strain energy index WET, bursting energy index Wcf, dynamic fracture duration time DT, and brittleness index B, of different coals and non-coal rocks were collected in China. Then, the differences of mechanical parameters and rockburst tendency indices between coal and non-coal rocks were studied systematically, and apart from the Poisson’s ratio μ, the other three basic mechanical parameters of coal and non-coal rocks have great differences in data distribution and concentration scope, which proved that the non-coal rocks cannot share the same index system and classification criteria of coals. In addition, the evaluation results of a single index for rock bursting liability of rocks were directly compared in pairs, and the inconsistency rate for coals is about 42–68%. It is necessary to build a comprehensive evaluation method to evaluate the bursting liability of rocks. At last, the modified rockburst tendency classification criteria for non-coal rocks were put forward. It is reasonable to use the classification criteria of the WET and Wcf to classify the bursting liability of non-coal rocks, while it is unreasonable to use that of the DT and σc. It has been concluded that the index B are more suitable for non-coal rocks, and a new index, named strength decrease rate (SDR), was proposed to determine the bursting liability, which is the ratio of uniaxial compressive strength σc to duration of dynamic fracture DT.

Study on the influence of the fault dip angle on the stress evolution and slip risk of normal faults in mining

To address the frequent occurrence of activation-induced rock bursts in fault zones during mining, the stress evolution and fault slip behavior of normal faults with different dip angles during mining are studied by mechanical models, numerical simulations, and engineering practice. The establishment of a mechanical model of faults and the deduction of the relationships between the fault slip and the fault dip angle θ and fault friction φ reveal the necessary conditions for fault slip. The results of an analysis of a numerical model show that the change in stress state in the surrounding rock caused by mining is the root cause of fault slip. During the mining process, the risk of fault slip changes as the working face advances, and the risk of induced fault slip is higher during mining in the footwall. With the increase in the fault dip angle, the risk of fault slip first increases and then decreases, and the most dangerous dip angle in terms of fault slip is determined. The simulation and field results are consistent with the theoretical results.

Experimental and Numerical Analysis of Rock Burst Tendency and Crack Development Characteristics of Tianhu Granite

Rock burst is a serious nonlinear dynamic geological hazard in underground engineering construction. In this paper, a true triaxial unloading rock burst experiment and numerical simulation are carried out on Tianhu granite to investigate the rock burst tendency and crack development characteristics of surrounding rock after excavation. The experiment and numerical simulation process monitored the rock burst stress path to determine the rock burst stress. According to the evolution law of the frequency and amplitude of rock burst acoustic emission monitoring, the shape characteristics of rock burst fragments are analyzed. The rock burst numerical simulation analysis is carried out by the PFC software, and the temporal and spatial evolution law of cracks is obtained. The research results show that the laboratory experiment and numerical simulation of Tianhu granite have rock burst strengths of 163.4 MPa and 161 MPa, respectively, and the average rock burst stress ratio is 8.38, that is, the Tianhu granite has a low rock burst tendency. During the rock burst, the development of tensile cracks will produce flaky debris, and the development of shear cracks will produce lumpy debris. Rock burst will happen when the crack growth rate to be exceeded the unloading crack growth rate; therefore, it can be used as a precursor signal for the occurrence of rock burst.

Studies and optimization of hybrid X-pinches

Studies were carried out on the hybrid X-pinch (HXP) configuration for several wire materials using a 40 ns risetime, 300-kA pulsed-power generator with the goal of optimizing the HXP x-ray burst parameters for different applications. The gap distance between the conical electrodes of the hybrid X-pinch was varied from 0.5 to 5 mm for Al, Ag, Ti, and Mo using different wire diameters to maintain a consistent mass per unit length from one material to the next. It was found that 0.5–1 mm gap spacing was optimal to obtain a single x-ray burst, while the number of x-ray bursts increased with gap spacing for all materials at a rate of 1–2/mm. Time consistency studies of the first x-ray burst were carried out for Ti wire by changing the gap distance and wire diameter while observing the time of occurrence of the x-ray bursts. It was found that a 40 μm Ti wire load with a 3 mm electrode gap spacing had the highest probability to have the first x-ray burst reproducibly within a 2 ns time window. Time-resolved and time-integrated diagnostics provided information about the source size, time of occurrence, intensity, and the number of the x-ray bursts.

Impact of Construction Method and Ground Composition on Headrace Tunnel Stability in the Neelum–Jhelum Hydroelectric Project: A Case Study Review from Pakistan

During underground construction, the behavior of the ground is influenced by characteristics of the rock mass with situ stresses and ground water, cross section of the excavation area, excavation method, and the rate of excavation. These fundamental features are considered to ensure the support and stability of underground excavations and achieve long-term successful operation. However, the ground composition of the Himalayas hinders tunnel excavation, especially in case of mechanized tunneling; this causes time and cost overruns. This study has reviewed the recently completed Neelum–Jhelum Hydroelectric Project; the project complexities, geological environments involving significant overburden and tectonic stresses, and effects of the excavation method on tunnel stability were analyzed. The major challenges that were encountered during construction are discussed herein along with their countermeasures. An analysis of project-related data reveals that latest techniques and approaches considering rock mechanics were used to complete the project; the existing approaches and methods were accordingly verified and extended. Apart from ground composition, the excavation methods used play an important role in the occurrence of severe rock bursts. Thus, the findings of this study are expected to be helpful for future tunneling projects in the Himalayas.

Chilling accumulation and photoperiod regulate rest break and bud burst in five subtropical tree species

The environmental regulation of spring phenology in boreal and temperate trees is generally well-understood, but little is known about the regulation in subtropical trees. It has been shown recently that similarly to the more northern trees, subtropical trees also exhibit rest (endodormancy) and chilling requirement of rest break (chilling requirement of endodormancy release), but the effects of photoperiod remain largely unexplored. Here we did an experimental study of the effects of chilling accumulation and photoperiod on the occurrence (bud burst percentage, BB%) and timing (days to bud burst, DBB) of bud burst in five subtropical tree species growing commonly in subtropical China. In all of the five species examined, both chilling accumulation and photoperiod showed a significant effect on DBB, and several significant effects were found for BB%. The responses to chilling accumulation and photoperiod we found are thought to be adaptive to the conditions of relatively short and warm subtropical winters: first, an independent effect of photoperiod would reduce the risk of frost damage caused by a premature bud burst in the case of false springs, which are especially common in subtropical conditions. Second, an interaction of photoperiod with chilling accumulation would facilitate a timely bud burst in spring after an exceptionally warm winter with reduced chilling accumulation. On the basis of our findings, we put forward a conceptual model for the various effects of chilling accumulation and photoperiod on rest break and bud burst in subtropical trees. The model facilitates future efforts towards developing process-based spring phenology models for subtropical tree species. Our limited but novel results show that 1) the modelling needs to address the effects of photoperiod; 2) because of the large differences found in the responses among the five species examined, the model development needs to be based on species-specific experimental data.

A Single Case Feasibility Study of Sensorimotor Rhythm Neurofeedback in Parkinson's Disease.

Electroencephalographic activity over the sensorimotor cortex has been one of the best studied targets for neurofeedback therapy. Parkinson’s disease patients display abnormal brain rhythms in the motor cortex caused by increased synchrony in the basal ganglia-cortical pathway. Few studies have examined the effects of sensorimotor-based neurofeedback therapy in humans with PD. In this pilot study, one patient, diagnosed with Parkinson’s disease 10 years prior, participated in two consecutive days of EEG neurofeedback training to increase sensorimotor rhythm (SMR) power over the motor cortex. Using a visual display connected to ongoing EEG, the patient voluntarily manipulated SMR power, and he/she was awarded with points to positively reinforce successful increases over a predefined threshold. Recorded EEG data were source localized and analyzed for the occurrence of high amplitude bursts of SMR activity as well as bursts in the beta frequency band in the precentral cortex. The rate of SMR bursts increased with each subsequent training session, while the rate of beta bursts only increased on the final session. Relative power in the beta band, a marker of PD symptom severity, decreased over the motor cortex in the later session. These results provide first evidence for the feasibility of SMR neurofeedback training as a non-invasive therapy for reducing Parkinson’s disease related activity and upregulating SMR in the human motor cortex.

Overtopping process and structural safety analyses of the earth-rock fill dam with a concrete core wall by using numerical simulations

Earth-rock fill dams are the most widely used dam type all over the world, and flood overtopping is the key reason causing dam burst. However, since an earth-rock fill dam with a concrete core wall is a modified new dam type, overtopping studies on these dams are rather deficient. The overtopping process and structural safety analyses of this new dam type have been studied in this paper by using a CFD-FEM coupled method based on the three-dimensional model of the Fangtianba reservoir expansion project. The scouring characteristics of the earth-rock fill dam, the variation trend of the downstream scouring depth, and the deformation as well as stress of the core wall have been obtained. Overtopping burst failure of the earth-rock fill dam with a concrete core wall is greatly affected by the downstream scouring depth, and tensile stress will occur on the upstream side of the core wall near the scour hole. When the downstream scouring depth is small and its growth is slow but stable, the tensile stress cannot exceed the allowable value in the early period of overtopping, and the concrete core wall may be able to support the dam body for a period of time, which might delay the occurrence of destructive collapse and overall burst. However, a sudden collapse may occur in the later period of overtopping; thus, reinforcement and emergency measures should be taken in time before the overall dam bursts.

Dynamic Characteristics of Fault Structure and Its Controlling Impact on Rock Burst in Mines

As one of the most serious shock dynamic disasters in coal mining, rock burst only occurs under the certain geodynamic environment. Geodynamic is the necessary requirement for the occurrence of rock burst, and the disturbance of mining engineering is the sufficient requirement. In terms of the fault structure, the method of geodynamic zoning is used to classify fault structure forms of rock burst in mines, and a model of geological structure is established to reveal the connection between fault structure and mine engineering. Besides, the influence of fault structure on rock burst is analyzed, and the controlling mechanism of the fault structure on the tectonic evolution of the mine area and the occurrence of rock burst is revealed. This research provides a treatment plan for the prediction and prevention of rock burst and guides the safe production in the coal mining engineering.

The 3-Axis Scalable Service-Cloud Resource Modeling for Burst Prediction Under Smart Campus Scenario

Internet of Things (IoT) enables smart campuses more convenient for cloud services. The availability of cloud resources to its users appears as a fundamental challenge. The existing research presents several auto-scaling techniques to scale the resources with the increase in users’ demands. However, still, the cloud users of auto-scaled servers experience service disruption, delayed responses, and the occurrence of service bursts. The prevailing burst management framework exhibits limitations in the context of burdening the existing auto-scaled machines for cost estimation and resource allocation. This research presents a 3-axis auto-scaling framework for load balancing and resource allocation by incorporating a dedicated cost estimator and allocator (on the z-axis). The cost estimation server develops a log of existing load estimates of vertical and horizontal servers and scales the new users’ requests in case the vertical threshold is breached with new requests. The cost estimator, in its data structure, keeps track of the current resources available at both vertical and horizontal servers. The historical information of available resources and the new resources’ requests is decided by the cost estimator as per demand and supply scenario. The general characteristics of servers are resources pooling, requests queue development, burst identification, automatic scaling, and load balancing. The cost estimator also prioritizes vertical servers for resource allocations, and switches to the horizontal server when the vertical server reaches its 75% quota of resources. The study simulates 1000 users’ requests of smart campus, adopts state-of-the-art ensemble with bagging strategy and handles an effective class imbalance situation.

A Search for Hard X-Ray Bursts Occurring Simultaneously with Fast Radio Bursts in the Repeating FRB 121102

Abstract The nature of fast radio bursts (FRBs) is currently unknown. Repeating FRBs offer better observation opportunities than nonrepeating FRBs because their simultaneous multiwavelength counterparts might be identified. The magnetar flare model of FRBs is one of the most promising models that predict high-energy emission in addition to radio burst emission. To investigate such a possibility, we have searched for simultaneous and quasi-simultaneous short-term hard X-ray bursts in all Swift/BAT event mode data, which covered the periods when FRB detections were reported in the repeating FRB 121102, by making use of BAT’s arcminute-level spatial resolution and wide field of view. We did not find any significant hard X-ray bursts that occurred simultaneously with those radio bursts. We also investigated potential short X-ray bursts that occurred quasi-simultaneously with those radio bursts (occurrence time differs in the range from hundreds of seconds to thousands of seconds) and concluded that even the best candidates are consistent with background fluctuations. Therefore, our investigation concluded that there were no hard X-ray bursts detectable with Swift/BAT that occurred simultaneously or quasi-simultaneously with those FRBs in the repeating FRB 121102.

Investigation of Pressure Relief Borehole Effects Using In Situ Testing Based on Distributed Optical Fibre Sensing Technology

Borehole pressure relief method is one of the most effective ways of rock burst prevention in coal mines. The measured results of borehole pressure relief at no. 8939 longwall face in Xinzhouyao coal mine, China, are presented here. The analyses identify the pressure relief magnitudes in coal mass around the boreholes with different diameters, spacing, and drilling time. This research has established that the best pressure relief of the rib coal can be achieved by using φ108 mm borehole with 0.7 m interval after 288 hours. The strain relief is acceptable after 288–360 hours of drilling, while the best result is achieved after 432 hours. It is also the first time to monitor the borehole pressure relief in a coal mine on‐site using Brillouin optical time domain reflectometer (BOTDR) distributed fibre‐optic sensing. The method implemented in this research provides new ways to improve stress relief design and minimize the rock burst occurrence for mine practitioners.

Improving the efficiency of electric arc furnaces through improved control algorithms for electrical modes

The aim of this study is to increase the efficiency of electric arc furnace through the use of advanced control algorithms for electrical modes. It was established that despite the common structure of the electric control system, as well as the approach to diagnosing the stage of the technological process, the criteria for switching from one combination of the furnace transformer tap and operating curve to another for electric arc furnaces and ladle furnaces are different. So, for EAF it is advisable to use a system in which a separate analysis of the signals of the relative effective value of the total even and odd harmonics of electric arc current (voltage) should be applied. It’s important to note that at the initial stage of melting it’s preferable to use even harmonics, and at the final stage of melting - odd harmonics. In it’s turn, during melting in LF, the argon blow mode and the slag mode have a significant role. Intensive blowing modes lead to the appearance of a metal mirror with the occurrence of bursts that occure short-circuit of the electric arc and lead to not optimal electric mode. According to the results of the analysis, a number of recommendations have been formulated that can have practical application in modernizing of modern control systems, aimed at optimizing production energy costs and reducing the unit cost of the final product of the metallurgical cycle. Moreover, the experience of implementing the described ides shows (for shaft-type electric arc furnace with capacity 125 ton, 85 MVA and ladle furnace 25 MVA) that the economic effect is 2.5% in terms of saving electric energy and 2% in terms of saving the consumption of electrodes. It’s a significant indicator taking into account the high energy intensity of modern electric steelmaking shops. This work was supported by the Ministry of Science and Higher Education of the Russian Federation (project No. FZRU-2020-0011).

Tibialis anterior electromyographic bursts during sleep in histamine-deficient mice.

Antihistamine medications have been suggested to elicit clinical features of restless legs syndrome. The available data are limited, particularly concerning periodic leg movements during sleep, which are common in restless legs syndrome and involve bursts of tibialis anterior electromyogram. Here, we tested whether the occurrence of tibialis anterior electromyogram bursts during non-rapid eye movement sleep is altered in histidine decarboxylase knockout mice with congenital histamine deficiency compared with that in wild-type control mice. We implanted six histidine decarboxylase knockout and nine wild-type mice to record neck muscle electromyogram, bilateral tibialis anterior electromyogram, and electroencephalogram during the rest (light) period. The histidine decarboxylase knockout and wild-type mice did not differ significantly in terms of sleep architecture. In both histidine decarboxylase knockout and wild-type mice, the distribution of intervals between tibialis anterior electromyogram bursts had a single peak for intervals < 10s. The total occurrence rate of tibialis anterior electromyogram bursts during non-rapid eye movement sleep and the occurrence rate of the tibialis anterior electromyogram bursts separated by intervals < 10s were significantly lower in histidine decarboxylase knockout than in wild-type mice. These data do not support the hypothesis that preventing brain histamine signalling may promote restless legs syndrome. Rather, the data suggest that limb movements during sleep, including those separated by short intervals, are a manifestation of subcortical arousal requiring the integrity of brain histamine signalling.

Seismic activity induced by exploitation in vicinity of mined-out space, case study from deep copper ore mine in Poland

Rock bursts are one of the most difficult to recognize and assess natural hazards in deep copper ore mines in Poland. The occurrence of rock bursts is conditioned by a number of complex geological and mining factors. The impact of each of the factors on the state of seismic hazard is sometimes impossible to be determined. The correct recognition of the rock mass condition and the causes of rock burst threat gives a chance for advance preparation of adequate prevention, and thus for eliminating or reducing the threat to the level of tolerated risk. In Poland’s copper ore mines, continuous observation of seismic activity is carried out, which is expressed in the number of tremors and their energy over a specified period of time. Moreover, the effectiveness of prevention measures and, in particular, of the active ones, which are aimed at provoking seismic energy emissions through properly executed winning blasting works, is calculated and analysed. Reducing the amount of energy accumulated in the rock mass reduces the risk of rock bursts. Exploitation is carried out in a way that avoids parallel approach of the operational front towards the goafs, drifts, and faults with drops greater than the height of the mined deposit. However, over forty years of mining of the copper ore deposit, which has created the large areas of mined-out space mean that mining works are increasingly carried out under restrained conditions. There are unfavourable geological and mining situations in the exploitation fields, disrupting rhythmic development and an even front line. The specific structure of the copper ore deposit in Poland makes it possible to conduct multidirectional cutting and to introduce local changes in the adopted directions of exploitation. Cases of operational fronts approaching goafs occur often in the vicinity of old mining infrastructure and when there is the need to mine remnant parts of the deposit not previously intended for exploitation or not mined yet. Generally, exploitation in the direction of goafs or yielding zones is limited to the cutting and yielding works. The purpose of the study was to analyse the seismic and rock burst hazard in an exploitation field located at a depth of 850 m in a copper ore mine, over a period of 5 years, when mining was carried out towards goafs. Seismic activity and the effectiveness of rock burst prevention measures were assessed and analysed. The active prevention i.e. the group winning blasting works was an inseparable element of the excavation technology. It was found that when the operational front progressed towards adjacent goafs, there were symptoms of an increase in rock mass pressure causing the destruction of roof rocks and, as a consequence, deterioration of roof stability, squeezing of floor, relaxation of the side walls and increase of seismic activity, which posed the potential threat of rock bursts.

Accretion bursts in magnetized gas-dust protoplanetary disks

Aims. Accretion bursts triggered by the magnetorotational instability (MRI) in the innermost disk regions were studied for protoplanetary gas-dust disks that formed from prestellar cores of a various mass Mcore and mass-to-magnetic flux ratio λ. Methods. Numerical magnetohydrodynamics simulations in the thin-disk limit were employed to study the long-term (~1.0 Myr) evolution of protoplanetary disks with an adaptive turbulent α-parameter, which explicitly depends on the strength of the magnetic field and ionization fraction in the disk. The numerical models also feature the co-evolution of gas and dust, including the back-reaction of dust on gas and dust growth. Results. A dead zone with a low ionization fraction of x≲10−13 and temperature on the order of several hundred Kelvin forms in the inner disk soon after its formation, extending from several to several tens of astronomical units depending on the model. The dead zone features pronounced dust rings that are formed due to the concentration of grown dust particles in the local pressure maxima. Thermal ionization of alkaline metals in the dead zone trigger the MRI and associated accretion burst, which is characterized by a sharp rise, small-scale variability in the active phase, and fast decline once the inner MRI-active region is depleted of matter. The burst occurrence frequency is highest in the initial stages of disk formation and is driven by gravitational instability (GI), but it declines with diminishing disk mass-loading from the infalling envelope. There is a causal link between the initial burst activity and the strength of GI in the disk fueled by mass infall from the envelope. We find that the MRI-driven burst phenomenon occurs for λ = 2–10, but diminishes in models with Mcore ≲ M⊙, suggesting a lower limit on the stellar mass for which the MRI-triggered burst can occur. Conclusions. The MRI-triggered bursts occur for a wide range of mass-to-magnetic flux ratios and initial cloud core masses. The burst occurrence frequency is highest in the initial disk formation stage and reduces as the disk evolves from a gravitationally unstable to a viscous-dominated state. The MRI-triggered bursts are intrinsically connected with the dust rings in the inner disk regions, and both can be a manifestation of the same phenomenon, that is to say the formation of a dead zone.

Study of Rock Burst Risk Evolution in Front of Deep Longwall Panel Based on Passive Seismic Velocity Tomography

Monitoring and early-warning are critical for the prevention and controlling of rock burst in deep coal mining. In this study, rock burst risk assessment criterion was built based on the correlativity between seismic velocity and stress state in coal and rock body. Passive seismic velocity tomography using mining-induced seismic waves was conducted regularly and continuously. The evolution of rock burst risk and range in front of a deep longwall panel with folds and adjoining goaf was determined. The influence of pressure-relief measures on rock burst risk was analyzed. The study results indicate that burst risk level and range during panel retreating increase first and then decrease, the peak is reached when it is located at 1# syncline shaft area. When approaching the crossheading, high burst risk zones distribute along the crossheading and further intersect with those in 1# syncline shaft area. Burst risk zones in the inclination of panel show distinct zoning features. Tomography results are in good agreement with the drilling bit result, rock burst occurrence, microseismic activity, and working resistance of hydraulic supports. Pressure-relief measures and mining layout have a distinct influence on burst risk of longwall panel. For prevention and controlling of rock burst risk in deep coal mining, pressure-relief measures should be optimized based on passive tomography results.