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KAGRA, the kilometer-scale underground gravitational-wave detector, is located at Kamioka, Japan. In April 2020, an astrophysics observation was performed at the KAGRA detector in combination with the GEO 600 detector; this observation operation is called O3GK. The optical configuration in O3GK is based on a power-recycled Fabry–Pérot–Michelson interferometer; all the mirrors were set at room temperature. The duty factor of the operation was approximately 53%, and the displacement sensitivity was approximately 1 × 10−18  |${\rm m}/\sqrt{\rm {Hz}}$| at 250 Hz. The binary-neutron-star (BNS) inspiral range was about 0.6 Mpc. The contributions of various noise sources to the sensitivity of O3GK were investigated to understand how the observation range could be improved; this study is called a "noise budget". According to our noise budget, the measured sensitivity could be approximated by adding up the effect of each noise. The sensitivity was dominated by noise from the sensors used for local controls of the vibration isolation systems, acoustic noise, shot noise, and laser frequency noise. Further, other noise sources that did not limit the sensitivity were investigated. This paper provides a detailed account of the KAGRA detector in O3GK, including interferometer configuration, status, and noise budget. In addition, strategies for future sensitivity improvements, such as hardware upgrades, are discussed. [ABSTRACT FROM AUTHOR]

Background: No study has investigated sleep‐related environmental factors in patients according to their functional independence measure (FIM) cognitive scores. Aims: The aim of this study is to examine the associations between environmental factors such as noise and sleep latency according to the FIM cognitive scores among inpatients in rehabilitation wards. Design This is a prospective longitudinal study. Methods: This study measured the sleep state using a bed‐based actigraphy, environmental data from Environmental Sensor®, and medical record information of 33 inpatients in the rehabilitation wards during 2018. A linear mixed‐effect model was used to analyse the associations between sleep latency and environmental factors. Participants were grouped according to high or low FIM cognitive scores. Results: The average patient age was 77.2 ± 10.9 years, and 48.5% were male. In the high FIM cognitive score group, the loudness and frequency of noise exceeding 40 dB during sleep latency were significantly associated with sleep latency. In the low FIM cognitive score group, only the noise frequency was associated with sleep latency, and intra‐individual variance was larger than that of the high group. Conclusion: These findings suggest that providing night care with attention to subdued noise is important, particularly for patients with low cognitive functional independence levels measured by the FIM cognitive score. Summary statement: What is already known about this topic? Many elderly individuals have sleep disorders, such as difficulties falling and staying asleep.Environmental factors, like light and noise, influence inpatients' sleep. What this paper adds? Patients with high functional independence measure (FIM) cognitive scores had longer sleep latency when both the loudness and frequency of noise exceeded 40 dB.Patients with low FIM cognitive scores had longer sleep latency with frequent noise, regardless of loudness.Nurses should provide care with more caution, taking into consideration the frequency of noise produced, regardless of loudness, particularly for patients with a low cognitive functional independence level measured by the FIM cognitive score. The implications of this paper For elderly inpatients with a lower cognitive functional independence level measured by the FIM cognitive score, the number of nurses' visits at night should be minimized to avoid disturbing the patients' sleep by using devices such as nonwearable sleep monitoring sensors, which can also contribute to reducing nurses' burden. [ABSTRACT FROM AUTHOR]

This paper investigates the potential vertical guidance performance of global positioning system (GPS)/wide area augmentation system (WAAS) user avionics sensor when the modernized GPS and Galileo are available. This paper will first investigate the airborne receiver code noise and multipath (CNMP) confidence (σair). The σair will be the dominant factor in the availability analysis of an L1-L5 dual-frequency GPS/WAAS user avionics sensor. This paper uses the MATLAB Algorithm Availability Simulation Tool (MAAST) to determine the required values for the σair, so that an L1-L5 dual-frequency GPS/WAAS user avionics sensor can meet the vertical guidance requirements of APproach with Vertical guidance (APV) II and CATegory (CAT) I over conterminous United States (CONUS). A modified MAAST that includes the Galileo satellite constellation is used to determine under what user configurations WAAS could be an APV II system or a CAT I system over CONUS. Furthermore, this paper examines the combinations of possible improvements in signal models and the addition of Galileo to determine if GPS/WAAS user avionics sensor could achieve 10 m Vertical Alert Limit (VAL) within the service volume. Finally, this paper presents the future vertical guidance performance of GPS user avionics sensor for the United States' WAAS, Japanese MTSAT-based satellite augmentation system (MSAS) and European geostationary navigation overlay service (EGNOS). [ABSTRACT FROM AUTHOR]

In this paper, a new adaptive vector directional distance filter (AVDDF) is proposed. The AVDDF filter is developed to remove the 'salt and papper' impulsive noise in color images. This algorithm consists in first step to detect pixels that are likely to have been contaminated with noise by using a threshold value. In second step, after recognizing the corrupted pixels, the smallest angular‐magnitude distance is used to replace the noisy pixels. The proposed filter is tested with several standard color images which are contaminated with various levels of 'salt and pepper' impulsive noise (3%, 5%, 10%, 20% and 30%). The performance of the proposed filter is measured with peak signal‐to‐noise ratio (PSNR) and normalized color difference (NCD). The simulation results show that the proposed filter permits to ameliorate the performance of the classic vector directional distance filter (VDDF). Indeed, it provides an improvement by an average of 5% and 26% in the PSNR and NCD relative to the VDDF filter, respectively, with a small increase in the execution time by 6%. Besides, the AVDDF filter allows also an enhancement by an average of 2% and 14% in the PSNR and NCD relative to adaptive vector median filter (AVMF), respectively. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Power transformer rooms have been gradually installed in residential buildings due to an increasing demand for power supply and space requirement. However, the noise generated by transformers during operation has become a hot topic of complaints. In order to solve the problem of transformer noise pollution and explore the rules of noise for power transformer rooms, a portable noise monitoring system consisting sensor array and a vibration and noise tester is developed in this paper. The noise characteristics of a power transformer room in Guangzhou city are obtained through field tests, which include the time‐domain characteristics, spectrum characteristics, and A‐weighted sound level characteristics. Results show that the frequency component of noises is stable, but the amplitude varies. The sound pressure of the power transformer room has obvious periodicity and the amplitude is 0.1–0.2 Pa. The dominant noise frequency is fixed at 300 Hz. According to different positions, the A‐weighted sound level is distributed between 55 and 65 dB. The research is not only of great help to formulate transformer noise assessment methods, but also of great significance to improve people's living environment and ensure power system's reliable operation. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Y‐capacitors are widely used in flyback converters to suppress common‐mode (CM) noise to comply with the strict electromagnetic interference (EMI) standards. However, Y‐capacitors increase the leakage current between the primary and secondary side, which is not allowed in the applications with high safety requirements. In this paper, the displacement current models of two conventional De‐Y methods are quantitatively established to analyze their limitations for the flyback converter. Then, a hybrid EMI‐optimized transformer is proposed to improve the limitations. The proposed structure can completely balance the CM noise between the primary and secondary sides, making the flyback converter comply with the EMI standard under the conditions of no Y‐capacitor. Compared with the traditional methods, the proposed method has a better capability for CM noise suppression, higher universality and the same cost. Finally, the simulation and experimental results verify that the CM noise of the new transformer structure decreases about 10 dB compared with that of the conventional one. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Landscape architecture and urban design disciplines could benefit from soundscape thinking in order to enhance experiential qualities in their projects, though the available tools are not yet fully developed nor tested. The present research aims to substantiate one of the available tools, Soundscape Actions, and thereby increase the understanding of soundscape design. The study focuses on the Japanese garden tradition, which is known for high preference ratings, tranquil qualities and consideration for sound and other sensory experiences. An autoethnographic approach was used to conduct field studies in 88 gardens in Japan, the majority of which are located in urban areas with potential noise disturbance. The studies are based on observations in situ, supported by video documentation, field recordings and readings of sound pressure levels (SPL). A total of 19 Soundscape Actions are described and discussed in the paper. They are structured around three main categories: localisation of functions, reduction of unwanted sounds and introduction of wanted sounds. The study provides concrete examples of how the tool can be used to enhance tranquil qualities, particularly focusing on small green spaces in dense urban settings, involving the (simultaneous) reduction of unwanted sounds and enhancement of wanted sounds/effects. The autoethnographic approach allowed for the phenomenological perspective to be brought forward, which contributed new insights regarding the design tool. The findings are discussed in relation to health and soundscape research, focusing on multisensory experiences, masking strategies and potentials for implementation and future developments of the design tool.

Information on several papers discussed at the 13th International Conference on Low Frequency Noise (LFN) and Vibration and its Control in Tokyo, Japan on October 20-23, 2008 is presented. Topics include the responses of people to LFN, the perception of LFN, and the problems caused by LFN. The conference featured several participants including Saiji Fukade, Yoshiyuki Maruta, and Setyamartana Parman.

This paper presents a software technique for analyzing the multidimensional time series of microseismic oscillations on the basis of over 14 years of continuous observations, from early 1997 to February 2011, at F-net (Japan) broadband seismic stations. An analysis of the multifractal parameters of low-frequency microseismic noise allowed us to hypothesize, in as early as 2008, that Japanese Islands were approaching a large seismic catastrophe, the signature of which was a statistically significant decrease in the support width of the multifractal singularity spectrum. Subsequently, as new data became available and after some new statistics of microseismic noise (such as a logarithm of noise variance and an index of linear predictability) were included in joint analysis, we obtained some new results, indicating the facts that the parameters of the microseismic background had been increasingly synchronized (the synchronization process was estimated to start in mid-2002) and that the seismic danger had permanently grown. A cluster analysis of background parameters led us to conclude that in mid-2010 the islands of Japan entered a critically dangerous developmental phase of seismic process. The prediction of the catastrophe, first in terms of approximate magnitude (mid-2008) and then in terms of approximate time (mid-2010), was documented in advance in a series of papers and in proceedings at international conferences. [ABSTRACT FROM AUTHOR]

As more and more automotive electronic devices have been employed and the level of sophistication of their functions has tended to increase, the needs for further enhancement of reliability of operation in an electromagnetic environment also have been increasing. This paper discusses laboratory measurement methods of RF conducted noise for automotive electrical and electronic devices. Also described are impedance characteristics with power line of six models of Japanese passenger vehicles, suggesting that the impedance can be characterized in three frequency ranges: 10 Hz to 1 kHz; 1 kHz to several megahertz; and several megahertz to 60 MHz. Characteristics of an artificial network simulated power line of the Japanese passenger vehicles are discussed. This paper proposes measurement methods and systems for conducted emission and susceptibility. The proposed system is functional in the 150 kHz - 60 MHz frequency range. In the emission measurement, a histogram of the noise level produced by EUT in the frequency domain can be measured, whereas in the susceptibility measurement system, malfunction modes with EUT, as well as the level of input to cause the EUT to malfunction, can be characterized. [ABSTRACT FROM AUTHOR]

Site resonance frequency is a crucial parameter for estimating site effects. However, there is currently no consensus on how to identify the bedrock interface to obtain the site resonance frequency. In this study, we identified 43 stations that can be regarded as one‐dimensional sites from the KiK‐net network in Japan, which consists of 699 stations. By analyzing the horizontal‐to‐vertical spectral ratio and surface‐to‐borehole spectral ratio of strong motion observation recordings, the fundamental resonance frequency (f0) of these 43 sites was determined. Subsequently, the correlation between the f0 values obtained from theoretical noise horizontal‐to‐vertical spectral ratio (NHV) with different bedrock interfaces and the f0 values determined from observation was analyzed. The conclusion shows that the f0 is primarily influenced by shallow interfaces with high S‐wave impedance contrasts (ICs). Specifically, when the bedrock interface is taken as the interface with ICs greater than 2.5 that appears for the first time, or the interface with ICs greater than 1.5 that appears for the second time, there is a strong correlation (greater than 0.86) between the f0 values obtained from theoretical NHV and from observation. These findings can provide a quantitative reference for accurately determining the fundamental resonance frequency. [ABSTRACT FROM AUTHOR]

Annoyance to noise is probably a good measure of the potential for complaint and community action. Each individual's degree of annoyance to noise cannot be accurately predicted from conventional laboratory studies and social surveys. Therefore, a logistic prediction model for individual allowable noise levels has been developed. In a previous paper [K. Furihata et al., Acta Acust. Acust. 93, 73-83 (2007)], an annoyance scale using the most frequently used annoyance ratings related to noise for community noise assessment in Japan was constructed. The dose-response relationships were obtained by actually listening to sounds in a field situation (1474 subjects) carried out at 14 metropolitan cities in Japan. The logistic prediction model was developed using the logistic regression parameters estimated from each cumulative percentage curve of seven annoyance scale scores based on all data (n=2940). To verify the hypothesis, individual relationships between annoyance and L(Aeq, (5 min)) for 24 normal-hearing subjects were constructed using a laboratory experiment. The main conclusion drawn from the results is that if at least one dose-response relation is obtained from each subject, the model can predict whether a sound is annoying or not from its L(Aeq,(5 min)) value. Moreover, validation of the model is needed in a field situation.

Many studies have shown the significant correlation between noise annoyance and noise sensitivity identified by Weinstein's noise sensitivity scale (WNS). However, the validity of the scale has not been sufficiently assessed. This study was designed to investigate the validity of each question in WNS and to develop a more valid noise sensitivity measurement scale. A questionnaire study was conducted in a residential area along trunk roads in Kusatsu, Japan, and 301 responses were collected. In this paper, noise sensitivity was defined as the factor that induced individual variability in reactions caused by noise exposure and that is not affected by the noise exposure. The relationship between noise exposure and answers to each question in WNS was investigated by multiple logistic regression analysis, and the influence of response bias on the score of WNS was examined. The results showed that WNS contained some questions that were inappropriately related to noise exposure level and that the score was affected by response bias. The reported correlation between annoyance and the score of WNS could be confounded by noise exposure and response bias. A noise sensitivity measurement scale named WNS-6B was newly developed, excluding the biased questions from the original WNS and applying binary coding to six-response options in order to reduce the response bias. WNS-6B seemed to be more appropriate to assess noise sensitivity than the original scale.

This paper focuses on the narratives and embodiment of noisemakers in noise complaints in a small town of rural Japan. By building on the intersection of sound studies, body, and migration, this paper aims to critically address the longstanding concept of 'noise' through the overlooked perspectives of migrants who are perceived as 'noisemakers' in the neighbor relations between Japanese neighbors and migrants. This study was conducted through months of fieldwork in a small town in Japan, wherein an ethnic concentration of Japanese descendants from North Sulawesi, Indonesia has been established for almost two decades. Sensory ethnography was adopted in addition to participant observation and in-depth interviews that presented the narratives of five Japanese descendants working in seafood processing factories. The findings suggest that perception of the 'unwanted' bodily presence becomes a salient metaphorical sense of 'noise' which is embodied in migrants as byproducts of the psychological noise of the hearers. This 'noise' evokes series of complaints which also escalate into space control in the neighborhood. More than just neighbor relations in negotiating private–public spaces, the phenomena of noisemaking and noise complaints in this study are layered with overlapping unequal social and power structures concerning neighbors, workers, and migrants with stigma of gaijin and 'noisemakers'. [ABSTRACT FROM AUTHOR]

The matrix inversion method (MIM) is an effective algorithm for estimating water constituent concentrations in case II waters. To apply this method, appropriate and accurate specific inherent optical properties (SIOPs) for each constituent in water are essential. However, many routine observations of lake water quality do not in fact provide SIOPs, thus limiting the application of the MIM. In this paper, an alternative MIM method based on linear matrix inversion theory was proposed to relax the requirement of SIOPs measurement. For this, so-called ESIOPs (Estimated SIOPs) were first derived by an unusual application of MIM based on adequate calibration samples; then the water constituent concentrations for the whole study area were retrieved by the standard application of MIM based on the derived ESIOPs. For each calibration sample, measurement of the reflectance spectrum and corresponding water constituent concentrations, which can be obtained from periodical satellite data and routine field surveys, is required. The performance of the proposed method was evaluated using the simulation data from Hydrolight and three MEdium Resolution Imaging Spectrometer Instrument (MERIS) images. The results showed that this method yielded satisfactory estimations of the water constituent concentrations for the noise-contaminated simulation data sets. For MERIS data in our study area (Lake Kasumigaura, Japan), the average bias (mean normalized bias or MNB) and relative random uncertainty (normalized root mean square error, or NRMS) were in the range of -11.2% to 3.4% and 4.8% to 29.7% for each water constituent concentration. These findings imply that the algorithm proposed in this study is theoretically reasonable and practically applicable. [ABSTRACT FROM AUTHOR]

LCGT is the large scale cryogenic gravitational wave telescope project in Japan in order to firstly detect gravitational waves. After the detection, the detector will be served as an astronomical tool to observe the Universe in collaborative observation with Advanced LIGO, GEO HF, Advanced Virgo and AIGO detectors. LCGT will contribute both the enterprise of detecting the gravitational wave events and the worldwide network for gravitational wave astronomy. This paper summarizes the status of LCGT. [ABSTRACT FROM AUTHOR]

In this paper, a RF front-end of the 5.8 GHz integrated CMOS dedicated short range communication (DSRC) transceiver for the Korea/Japan electronic toll collection system is presented. The receiver uses low-IF conversion architecture for high sensitivity and low-power consumption while the transmitter uses direct up-conversion architecture for its simple structure and reliability. To solve image problem in the low-IF receiver, 10 MHz IF and 40 MHz IF are chosen for Korean and Japanese DSRC standards, respectively, since they make no image signals exist in image band. A single-quadrature mixer with the proposed transconductor-type quadrature generator in RF signal path is also adopted which has accurate quadrature characteristic in 5.8 GHz frequency. [ABSTRACT FROM PUBLISHER]

Sedimentary basins can strongly amplify seismic waves from earthquakes. To better predict future ground motions, detailed knowledge of the sediment thickness and internal structure of basins is required. We image the sediment-to-bedrock interface of the Kanto Basin in Japan using the P -wave reflectivity response from earthquake and ambient seismic noise autocorrelation functions (ACFs) at 286 shallow borehole stations. Earthquake ACFs are computed using P -wave records from 50  M w 6+ teleseismic events. Noise ACFs are obtained using 1 month of continuous data. Both methods are used to retrieve P -wave traveltimes between the surface and the bedrock interface and map the basin basement geometry. Our prediction of the basement depth agrees generally well with that from a reference velocity model, except for smoother variations in the central part of the basin. Using full-wavefield simulations, we show that the nature of the autocorrelated wavefield has a significant impact on the shape of the ACF waveforms and that earthquake ACFs yield more accurate results in the Kanto Basin. [ABSTRACT FROM AUTHOR]

A limited number of studies have explored drum brake noise with uncertainty. Therefore, a new method for the robust design of drum brakes is presented herein on the basis of complex modal analysis and Taguchi's robust design. Based on the finite element method, complex modal analysis is used to predict drum brake noise. Taguchi's robust design is adopted to reduce drum brake noise and improve system robustness. In this method, the Young's moduli of the brake drum, brake shoes, and friction lining are considered as control factors, the friction coefficient and brake pressure are taken as noise factors, and the weighted instability tendency coefficient is regarded as the objective function. When the proposed method is applied to drum brake design, drum brake noise is significantly reduced and system robustness is increased. Specifically, the signal‐to‐noise ratio increases by 62.94%, and the average value of the weighted instability tendency coefficient decreases by 91.7%. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In this work, comprehensive analysis on single and dual mode, uniform and apodized Fiber Bragg Grating (FBG) based gas concentration measurement sensor performance in the presence of noise and temperature variations is presented. Different scenarios are formulated. Firstly, the indirect sensing method for gas concentration measurement is presented, followed by the discussion on single and dual mode uniform FBG sensor design. Thereafter single and dual mode Gaussian apodized FBG sensor design and its pros and cons are discussed. The effect of temperature variations and noise on FBG sensor is also discussed. Afterwards as per referred literature the simulation results for uniform and apodized FBG in the presence or absence of noise, temperature variations and strain applications are validated. The quantitative analysis shows that the single mode apodized FBG has highest side lobes suppression ratio which is 88.21%. In terms of FWHM single mode apodized FBG has narrowest bandwidth of amplitude 0.18. While dual mode apodized FBG has highest reflectivity, that is, −0.20571. It is observed that reflection spectrum of uniform FBG sensor contains large strength of side lobes at adjacent wavelength. Moreover, the dual mode FBG sensor performance is more affected by variation in temperature and noise but dual mode FBG sensor works better as compared to single mode FBG sensor in context of minimum side lobes, high absorption depth and enhanced reflectivity. The presented investigation will be helpful to prescribe the correct amount of dosage for biomedical application. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper discusses the role of the public in solving noise problems, through a review of the history of the car horn noise problem in Japan. Noise problems caused by car horns began occurring around 1930, and subsequently recurred around 1950. In both cases, official regulations were enacted; however, these regulations were only temporarily effective. It was a civic movement, in which a variety of groups participated, that ultimately led to a permanent resolution of the issue. The most important factors for the success of this movement were believed to be the breadth of participation and the successful fulfillment of each group's role. History suggests that regulations alone are insufficient for resolving the issue of noise problem from vehicles, and public participation is crucial to achieve a solution and further improve the soundscape. Moreover, it appears that the role of the public in solving noise problems lies in their change of attitude toward, and active efforts to control, noise. Therefore, the most important point of discussion regarding social aspects of a noise policy must concern how to involve a large proportion of the public in the resolution of noise problems and further improving the soundscape. [ABSTRACT FROM AUTHOR]

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In recent years, a controversy has arisen in Japan regarding an ongoing landscape policy proposing to eliminate the forest of utility poles and electric wires that covers almost all urban and rural landscapes. The controversy is somewhat peculiar vis-à-vis the existing study of landscape, partly because of the utterly ubiquitous and non-monumental characteristics of the poles and partly because of the general apathy in public reaction to them. Drawing upon diverse academic sources, this interdisciplinary exploration unfolds a complex entanglement of tacit landscape ideas behind the controversy. The author discusses the effectiveness and limits of addressing both the substantial and visual aspects of the poles vis-à-vis the public and policy makers by using three conceptual frameworks: (1) 'erasure' in the landscape as palimpsest, (2) the dual aspects of 'noise', and (3) artialisation, in order to understand this mundane element of technological objects in the context of creating contemporary landscapes. [ABSTRACT FROM AUTHOR]

Development of an accurate reservoir model and prediction of reservoir behaviour associated with geothermal exploitation using that model are fundamentally important for sustainable geothermal utilisation. Gravity observation for a few tens of days after a field-wide shut-in of geothermal wells potentially provides valuable constraints to improve reservoir models. We investigated the applicability of superconducting gravimeters (SGs) to short-term observations after shut-ins, as a first step towards the development of a method for reservoir model improvement using short-term gravity data. Results from a reservoir simulation of a shut-in at a geothermal field in Japan showed that gravity change at 20 days after the shut-in was 10 nm/s2. To detect such changes with SGs, locations of SG stations should be chosen to minimise noise sufficient to resolve the signal. Considering that field operations and traffic in geothermal fields can make SG data noisy, laboratory gravity measurements were carried out with a SG to investigate the influence of noise level on signal detection. Test masses, which produced a gravity change (7.7–9.0 nm/s2) comparable to the simulation result, were repeatedly placed and removed above the SG during both day and night times with different ambient noise levels. Test results showed that noise level greatly affected signal detection. The signal was only detected twice, under low-noise conditions with the standard deviations of 1.1 and 5.3 nm/s2. In addition, tests in which the SG was operated without a cryogenic refrigerator revealed that the absence of the refrigerator did not increase the noise level. Enhancing the portability of a SG by reducing its weight can make multi-location noise surveys feasible. Our method, of combining reservoir simulations and preliminary noise surveys, would enable successful SG observations to be made in relatively short periods after shut-ins, which would possibly contribute to the development of a method to obtain additional constraints to be used for reservoir model calibration. [ABSTRACT FROM AUTHOR]

In recent years, deep learning has achieved very good results because large amounts of learning data have become easily available due to improvements in computer capabilities and big data. However, it has a problem that the accuracy becomes very bad for strong noise. Therefore, in this study, we compare the classification accuracy of existing mainstream neural networks, including broad learning, convolutional neural network and multilayer perceptron. Then, their performance is verified according to the experimental results by using noise‐added MNIST and Fashion MNIST database. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In the Integrated Ocean Drilling Program (IODP), the long-term borehole monitoring system (LTBMS) has been planned for installation into boreholes in seafloor settings in the Nankai Trough, Japan. The LTBMS sensors are extremely sensitive instruments for collecting broadband dynamics to elucidate the mechanisms of megathrust earthquakes, which occur repeatedly in plate subduction zones. However, during IODP Expedition 319, it became apparent that the strong ocean current “Kuroshio” causes vortex-induced vibration (VIV) that damages sensors during installation. Consequently, the LTBMS sensors must be not only highly sensitive but also robust to prevail against VIV. Therefore, sensors with antivibration mechanisms were developed by a Japan Agency for Marine-Earth Science and Technology (JAMSTEC, Kanagawa, Japan) project team. After development was completed, noise evaluation tests and vibration and shock tests simulating vibration and shock in the installation scheme were conducted to confirm that the antivibration mechanism was functional. Power spectral density analysis was conducted using background noise recorded in a low-noise location before and after the vibration and shock tests. Results show that the sensor response was not changed by the vibration or shock tests. Finally, all sensors were loaded onto D/V Chikyu for installation at the C0002 site during IODP Expedition 332. [ABSTRACT FROM PUBLISHER]

Adjacent channel interference characteristics due to two PSK signals are discussed based on experimental and theoretical analysis. Experiments were conducted in-house and by using a Ku-band satellite. The experimental approach indicates that the interference characteristics (bit error rate) depend on the ratio of interference to desired signal power for the weak interference, irrespective of different interference conditions. The theoretical approach proposes the estimation of interference characteristics based on the amplitude probability density function of interference signal components. It is found from quantitative evaluation that although the conventional method, which treats interference as thermal noise, estimates the interference characteristics well only for the weak interference, the proposed method estimates the interference characteristics well for both weak and strong interference. Finally, the required increase of the signal power in compensation for the degradation of the bit error rate and achievement of the objective bit error rate is discussed. © 2000 Scripta Technica, Electron Comm Jpn Pt 1, 83(7): 92–102, 2000 [ABSTRACT FROM AUTHOR]