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The directivity pattern of a powerful GPR has been studied in archeological works. The methods used: return pulse measurements by passing a compact underground object, multiple passages with changing antennas azimuth for estimating the horizontal directivity, use of a prolonged overhead object in order to estimate spurious radiation into the upper hemisphere.

[...]remember to always follow facility safety rules, such as those outlined in NFPA 70E, comply with company and local policies, and ensure only qualified personnel perform testing and use appropriate personal protective equipment (PPE). Voltage shows you the disturbance, but current reveals the load information and PQ event directivity. Remember that there can be multiple sources for equipment problems and downtime, and power is just usually the first to be blamed. If there are power problems, then the data captured by the PQ instruments should help determine the source of the problem, next steps, and corrective actions.

In order to analyze the directivity of the array composed of different shape array elements, a line array is made up of the point source, circular, annular and rectangular piston sound source, and the directivity of the array is analyzed by simulation software. The results show that the directivity of line array is influenced by many factors, such as array element spacing, geometric dimensions, array shape, number of array elements, wave number or frequency, etc. When the condition is equivalent, the directivity of the transducer array composed of annular array element is relatively optimal.

Singing voice directivity for five sustained German vowels /a:/, /e:/, /i:/, /o:/, /u:/ over a wide pitch range was investigated using a multichannel microphone array with high spatial resolution along the horizontal and vertical axes. A newly created dataset allows to examine voice directivity in classical singing with high resolution in angle and frequency. Three voice production modes (phonation modes) modal, breathy, and pressed that could affect the used mouth opening and voice directivity were investigated. We present detailed results for singing voice directivity and introduce metrics to discuss the differences of complex voice directivity patterns of the whole data in a more compact form. Differences were found between vowels, pitch, and gender (voice types with corresponding vocal range). Differences between the vowels /a:, e:, i:/ and /o:, u:/ and pitch can be addressed by simplified metrics up to about d2/D5/587 Hz, but we found that voice directivity generally depends strongly on pitch. Minor differences were found between voice production modes and found to be more pronounced for female singers. Voice directivity differs at low pitch between vowels with front vowels being most directional. We found that which of the front vowels is most directional depends on the evaluated pitch. This seems to be related to the complex radiation pattern of the human voice, which involves a large inter-subjective variability strongly influenced by the shape of the torso, head, and mouth. All recorded classical sung vowels at high pitches exhibit similar high directionality.

The article presents various types of emitter designs and schemes of emitting surfaces for the formation of ultrasonic fields with different characteristics and directivity. 4 types of emitters have been developed and their main characteristics have been determined. It has been established that a radiator with a flat frontal surface provides 167 dB and makes it possible to intensify a number of technological processes in the near zone (up to 1 meter), such as coagulation and drying. An emitter with a step-variable surface and predominant radiation of one phase of oscillations makes it possible to create a homogeneous ultrasonic field in the air at a sound pressure level of 155-157 dB at a distance of up to 2 meters to the emitter. Focusing radiators allow to provide sound pressure level up to 173 - 177 dB in the focus (at a distance of 0.3 m), while in the far zone the intensity drops significantly (up to 145-150 dB).

This paper investigates the sound field generated by built-in loudspeakers in flat-panel televisions. An automated measurement rig was developed to capture full-azimuth impulse responses of a TV mock-up. The measured sound field is analysed in terms of directivity, insertion loss (IL), and the influence of edge diffraction. Simulations based on the Macdonald solution for edge diffraction are employed for comparison. Results show that the overall sound field is strongly shaped by cabinet-edge and panel-edge diffraction: IL increases with frequency, with close agreement between model and measurement above 2 kHz, while larger deviations appear at low frequencies. The study provides insights into how edges affect perceived sound quality and offers guidance for TV loudspeaker measurements and design.

Due to the scarcity of data analysis on receiving low-frequency signals with conventional arrays and the difficulty of processing low-frequency signals with conventional arrays in practical environments, this paper utilizes the theory of spherical acoustic scattering normal mode solution to simulate the sound field intensity on the surface of a sphere with different frequencies and boundary conditions, and compares the simulation results with experimental data. The results show that the elastic sphere model is relatively close to the actual situation at lower frequencies, but cannot be approximated by an elastic model at higher frequencies. Furthermore, at lower frequencies, the peak of the directional pattern is in the opposite direction to the incoming wave. The research results can provide some reference for improving the directional ability of conventional spherical arrays towards low-frequency signals.

Analysis of earthquake rupture directivity provides key information for seismic hazard and risk assessment, particularly for faults near urban areas. We analyze directivity patterns for 31 well‐constrained ML≥${M}_{L}\\mathit{\\ge }$  3.5 earthquakes along the Main Marmara Fault, in direct proximity to Istanbul. We calculate source mechanisms with a waveform modeling approach and analyze earthquake directivity from apparent source‐time functions using empirical Green's functions. Most of the strike‐slip earthquakes to the west of the Princes Islands segment display a predominantly asymmetric rupture toward the east with the median directivity trending 85°, consistent with the Main Marmara Fault strike. Consequently, earthquake ground shaking may be more pronounced toward Istanbul. This holds potentially for a large earthquake on the Main Marmara Fault which is late in its seismic cycle. Our results motivate the importance of evaluating the impact of eastward asymmetric ruptures on the probabilistic seismic hazard and risk assessment around Istanbul. Plain Language Summary Analyzing how earthquakes release the accumulated strain energy in space can help us understand the resulting shaking in particular locations. We studied 31 earthquakes with magnitudes ML≥${M}_{L}\\mathit{\\ge }$  3.5 that occurred along the North Anatolian Fault in the Marmara region near Istanbul, northwestern Türkiye. We derived orientations of fault planes using focal‐mechanism inversion, as well as the direction in which the seismic energy release is focused (rupture directivity). We find that most of the analyzed earthquakes display strike‐slip movement, matching the orientation of the GPS‐derived deformation field in this area, which is different from previous studies proposing dominantly normal faulting kinematics, particularly on the western part of the Main Marmara Fault. We also find that earthquakes to the west of the Princes Islands south of Istanbul radiate seismic energy mostly toward the east. This also suggests that the ground shaking from the earthquakes could be stronger toward Istanbul and weaker in the opposite direction. Our findings show that it is important to consider how earthquake ruptures propagate when evaluating the earthquake risk, especially near urban areas. Key Points Directivities of 31 ML${M}_{L}$3.5–5.7 earthquakes along the Marmara seismic gap were estimated from apparent source‐time function variations 72% of strongly asymmetric earthquakes show directivity toward the east, implying higher ground motions toward the Istanbul region The rupture directivities are consistent with right‐lateral east–west trending source mechanisms at the Main Marmara Fault

An acoustic orientation method using the directivity of sensing channels in distributed fiber optic hydrophone (DFOH) is presented and demonstrated. Theoretical analysis shows that the sensing channel of DFOH is directional. Based on the directivity function of the channel, the direction of the acoustic signal can be obtained by scanning the length of the sensing channel, which is confirmed by experiments.

At present, in the detection and identification of underwater noise sources, one of the most commonly used transducer arrays is the circumferential transducer array. The circumferential transducer array is symmetrical in space and has high withstand voltage capability and small sound pressure fluctuation in the horizontal beam. Its directivity is an important index that affects the performance of the array. This paper focuses on the directivity maps of circular arrays with different sizes and numbers of elements. From the graph, it is concluded that the undulation of the directivity graph of the circular array is directly related to the array element spacing. The smaller the array element spacing is, the smaller the undulation is, and vice versa. The directivity formula and law can provide technical guidance for the design of a uniform circular transducer array.