Strong Echoes Research Articles

Animal Suffering, God and Lessons from the Book of Job

Nature shows itself to us in ambivalent ways. Breathtaking beauty and cruelty lie close together. A Darwinian image of nature seems to imply that nature is a mere place of violence, cruelty and mercilessness. In this article, I first explore the question of whether such an interpretation of nature is not one-sided by being phrased in overly moral terms. Then, I outline how the problem of animal suffering relates to a specific understanding of God as moral agent. Finally, in the main part of the argumentation, I pursue the question to what extent the problem of animal (and human) suffering does not arise for a concept of God couched in less personalistic terms. If God’s perspective towards creation is rather de-anthropocentric, then moral concerns might be of less importance as we generally assume. Such an understanding of the divine is by no means alien to the biblical-theistic tradition. I argue that it finds strong echoes in the divine speeches in the Book of Job: They aim at teaching us to accept both the beauty and the tragic of existence in a creation that seen in its entirety is rather a-moral. Finally, I address the question what such a concept of God could mean for our existence.

An innovative echo detection system with STM32 gated and PMT adjustable gain for airborne LiDAR

ABSTRACT In bathymetric Airborne LiDAR (Light Detection And Ranging) for the measurement of various water depths, the echo of the laser signal is amplified by an amplifier circuit, the water surface is usually saturated, which results in a serious effect on the bottom echo signal. Therefore, this paper designs a LiDAR echo signal detection timing control system. The system adopts the STMicroelectronics32 (STM32) controller as the gated signal generator; acts on the photomultiplier tube (PMT) photoelectric conversion circuit; and adjusts the amplitude, frequency, period, and duty cycle of the gating trigger signal to achieve timing control, thus allowing the system to directly avoid the reception of overly strong surface echo signals and increasing the accuracy of the experimental results. The system combines PMT adjustable voltage control gain technology applies the weak underwater echo signal that is amplified to facilitate subsequent collection. In the actual measurement, using STM32 instead of the traditional signal generator, which can reduce the power consumption and load capacity of the system. The experimental results show that the system can amplify the underwater signal by at least 6-fold while avoiding the effect of the surface echo signal.

Emancipação no processo criativo autobiográfico

In the following text we propose to think about how the creative methodology of an artistic project, of a hybrid nature, between film and performance, dialogues with the problems of autobiography and feminist theories. In support of the thesis that feminist performances identify a strong echo of autobiographical expressions, we analyse the film Nether Ballerina of Rottingdam (Demetri Estdelacropolis, 2005-2007) as a process of (re)creation and affirmation of the feminine We browse Bergson’s theories to work on the processes of memory in the field of philosophy; we quote, among others, Philippe Lejeune and Paul De Man to contextualize the history and relevance of biographical and autobiographical writing. Then we address the feminist movement that has provided, since the early 1970s, fertile ground for the production of performative work of a feminist nature, committed to the private and public experience of women (Carlson, 2004). By correlating autobiographical creation to the new waves of feminist theory, we intend to focus in particular on those aspects of autobiography which cross with gender issues. In the film under analysis, the dancer intends to emancipate herself from the status of muse of the filmmaker and move into the role of director, taking over the material documented by Estdelacropolis, by making the film Nether Ballerina. By reconverting the body in movement into image in movement, the ephemeral into perennial, she rescues a new narrative for her representation. Michel Foucault, Judith Butler and Donna Haraway are the authors contemplated to articulate this idea.

Reference-free AEC for Alexa Barge-In

When an Alexa built-in device is in playback mode, users need to make extra effort to cut through acoustic echo from the audio playback (music or synthesized speech signals) to activate the wakeword detector and start talking to Alexa, i.e., to barge into the conversation. These are high-friction events where Alexa customers typically experience a higher false reject rate (FRR). The acoustic echo canceller (AEC) and beamformer in the multichannel Audio Front End (AFE) are essential to mitigate the effect. But when playback volume is high, AFE outputs still contain strong residual echoes which downstream wakeword detection models could have difficulty to handle. In this talk, we will present an innovative multi-microphones yet array-agnostic, reference-free AEC tailored specifically for wakeword detection. As opposed to the traditional AEC, the new approach has five practically attractive benefits: (1) reference-free and array agnostic (a blind method suitable for in-model implementations); (2) inherently immune to loudspeaker nonlinearities; (3) free of synchronization/alignment hassle; (4) more microphones, more gains; (5) kills two birds with one stone (cancels both echo and noise). A proof-of-concept experiment will be discussed to validate the effectiveness of the proposed novel algorithm.

Stage characteristics and causes of a mixed severe convective weather process

Based on the conventional observation data, the intensive automatic weather station data, the 1°×1° Final Operational Global Analysis data and the Doppler radar data, this study analyzes the stage characteristics and causes of a mixed severe convective weather process in Hunan Province from April 23 to 24, 2019. The results show that this severe convective weather mainly has two stages. In the first stage, the disastrous weather is mainly the short-term heavy precipitation. The convective weather in this stage is a severe mixed convective weather process forced by warm advection. The short-term heavy precipitation is mainly caused by the continuous influence of multi-cell storms. The disastrous weather in the second stage is mainly the thunderstorm gale. It is a squall line process forced by upper-level cold advection. Besides, there is apparent mid-altitude radial convergence and high wind core on the radial velocity map. The surface convergence line is the primary dynamic uplift condition triggering the mixed convection in the first stage, and there are several abnormal low centers of three-hour pressure change in the western and southern Hunan. The severe convective weather process in the second stage is mainly triggered by the forward-tilted trough. The dynamic conditions and energy conditions are favourable for the convections at both stages. Compared with the second stage, water vapor is more abundant in the first stage, which is more favorable for the occurrence of short-term heavy precipitation. The three-body scatter spike of hail is not obvious before the formation of the squall line. The early warning signals are mainly the height of the strong echo and vertical integrated liquid water content, both of which increase significantly before the formation of the squall line. The early warning of thunderstorm gale after the formation of the squall line can be issued in advance by monitoring the low-level wind in the downstream areas of the squall line.

Wingtip folds and ripples on saturniid moths create decoy echoes against bat biosonar

Sensory coevolution has equipped certain moth species with passive acoustic defenses to counter predation by echolocating bats.1,2 Some large silkmoths (Saturniidae) possess curved and twisted biosonar decoys at the tip of elongated hindwing tails.3,4 These are thought to create strong echoes that deflect biosonar-guided bat attacks away from the moth's body to less essential parts of their anatomy. We found that closely related silkmoths lacking such hindwing decoys instead often possess intriguing ripples and folds on the conspicuously lobed tips of their forewings. The striking analogy of twisted shapes displayed far from the body suggests these forewing structures might function as alternative acoustic decoys. Here we reveal that acoustic reflectivity and hence detectability of such wingtips is higher than that of the body at ultrasonic frequencies used by hunting bats. Wingtip reflectivity is higher the more elaborate the structure and the further from the body. Importantly, wingtip reflectivity is often considerably higher than in a well-studied functional hindwing decoy. Such increased reflectivity would misdirect the bat's sonar-guided attack toward the wingtip, resulting in similar fitness benefits to hindwing acoustic decoys. Structurally, folded wingtips present echo-generating surfaces to many directions, and folds and ripples can act as retroreflectors that together create conspicuous targets. Phylogenetically, folds and ripples at wingtips have evolved multiple times independently within silkmoths and always as alternatives to hindwing decoys. We conclude that they function as acoustic wingtip decoys against bat biosonar. VIDEO ABSTRACT.

Role of ultrasound in the diagnosis of cervical tuberculous lymphadenitis in children

BackgroundTo describe sonographic characteristics of cervical tuberculous lymphadenitis (CTBL) in children, clinical information, and sonograms of 348 lymph nodes (LNs) from 57 children with CTBL were retrospectively analyzed in this study.MethodsWe retrospectively reviewed the clinical data and sonograms of 348 LNs from 31 boys and 26 girls with CTBL, who were confirmed by pathology or laboratory examination, at the Hangzhou Red Cross Hospital between June 2014 and December 2020. The age of the children ranged from 1 to 14 years (average 7.1 ± 2.9 years).ResultsNight sweats, fatigue and loss of appetite were the most common clinical symptoms observed in children with CTBL. Unilateral LN involvements were common. Occasionally, CTBL was found in healthy children with no symptoms. On sonography, the hilus was absent or unclear in all LNs. The short-to-long axis (S/L) ratio was ≥ 0.5, and the edges were unclear in most LNs. Other accompanying findings included necrosis (47.4%), an echogenic thin layer (36.8%), surrounding soft-tissue edema (38.5%), multiple intra-nodal strong echo (28.2%), sinus (22.7%) and abscess formation (6.9%). The Doppler ultrasound showed that the majority of vascularity patterns of CTBL were capsular or peripheral (33.3%).ConclusionsUltrasound is a recommended examination method for children from different age groups with cervical lymphadenitis. The ultrasonic signs of hilus absence, S/L ratio ≥ 0.5, unclear edge, necrosis, echogenic thin layer, strong echoes and capsular or peripheral vascularity may aid in the diagnosis of cervical tuberculous lymphadenitis.

Cataract detection based on ocular B-ultrasound images by collaborative monitoring deep learning

In this paper, we collect an ocular B-ultrasound image dataset and propose a Collaborative Monitoring Deep Learning (CMDL) method to detect cataract. In the ocular B-ultrasound images, there are often strong echoes near the posterior capsule and lens, and the fine-grained ocular B-ultrasound images are often accompanied by the characteristics of weak penetrating power, low contrast, narrow imaging range, and high noise. Thus, in the proposed CMDL method, we introduce an object detection network based on YOLO-v3 to detect the focus areas we need, so as to reduce the interference of noise and improve the cataract detection accuracy of our method. Considering that the B-ultrasound image dataset we collected is small-scale, we also design three feature extraction modules to avoid over-fitting of the deep neural networks. Among them, there are a depth features extraction module based on DenseNet-161, a shape features extractor based on Fourier descriptor, and a texture features extraction module based on gray-level co-occurrence matrix. Moreover, we also introduce the collaborative learning module to improve the generalization of the proposed model. Specifically, we first fuse the depth, shape, and texture features of the eyeball and lens, respectively. Then, the fused features of the eyeball and lens are concatenated as the input of collaborative network. Finally, the introduced classification loss with the aid of collaborative loss, which distinguishes whether the eyeball and lens belong to the same category, improves the classification accuracy in cataract detection. Experimental results on our collected dataset demonstrate the effectiveness of the proposed CMDL method.

Radar Observation of Extreme Vertical Drafts in the Polar Summer Mesosphere

AbstractThe polar summer mesosphere is the Earth's coldest region, allowing the formation of mesospheric ice clouds. These ice clouds produce strong polar mesospheric summer echoes (PMSE) that are used as tracers of mesospheric dynamics. Here, we report the first observations of extreme vertical drafts (50 ) in the mesosphere obtained from PMSE, characterized by velocities more than five standard deviations larger than the observed vertical wind variability. Using aperture synthesis radar imaging, the observed PMSE morphology resembles a solitary wave in a varicose mode, narrow along propagation (3–4 km) and elongated ( km) transverse to propagation direction, with a relatively large vertical extent (13 km). These spatial features are similar to previously observed mesospheric bores, but we observe only one crest with much larger vertical extent and higher vertical velocities.

Application of a Radar Echo Extrapolation‐Based Deep Learning Method in Strong Convection Nowcasting

AbstractStrong convection nowcasting has been gaining importance in operational weather forecasting. Recently, deep learning methods have been used to meet the increasing requirement for precise and timely nowcasting. One of the promising deep learning models is the convolutional gated recurrent unit (ConvGRU), which has been proven to perform better than traditional methods in strong convection nowcasting. Despite its encouraging performance, ConvGRU tends to produce blurry radar echo images and fails to model radar echo intensities that have multi‐modal and skewed distributions. To overcome these disadvantages, we tested the structural similarity (SSIM) and multiscale structural similarity (MS‐SSIM) indexes as loss functions. The SSIM and MS‐SSIM loss functions are composed of luminance, contrast, and structure and provide more information about the intensity, grade, and shape of the radar echo, which can reduce blurring. Due to multi‐layer downscaling, MS‐SSIM extracted more radar echo characteristics, and its extrapolation was the most realistic and accurate among all of the loss function schemes. Only the MS‐SSIM scheme successfully predicted strong radar echoes after 2 h, especially those at the rainstorm level.

Clinical analysis of 52 adolescent patients with ovarian masses ≥10 cm in diameter.

ObjectiveTo investigate the clinical characteristics and treatment of large ovarian masses in adolescents.MethodsAdolescents with large ovarian masses (≥10 cm in diameter) who were treated in Beijing Obstetrics and Gynecology Hospital from March 2010 to December 2018 were retrospectively assessed.ResultsFifty-two female patients (mean age: 16.17±2.04 years [11–19 years]) were included and 19 (36.5%) presented with abdominal pain. The blood flow signal rate in ultrasonography was significantly different among benign, borderline and malignant ovarian masses, unlike strong echo, dotted echo and septation rates. Carbohydrate antigen 125 positivity rates were significantly different among pathological types and the endometriotic cyst group showed the highest value (75.0%). Alpha-fetoprotein positivity rates were also different among pathological types. For ovarian cystectomy, 14 and 32 patients underwent laparotomy and laparoscopy, respectively. Mass diameters were significantly higher in the laparotomy group and the operative duration was significantly shorter in the laparoscopy group. There were no significant differences in intraoperative blood loss or postoperative recurrence rates between the two groups.ConclusionTeratomas constitute the greatest group of large ovarian masses in adolescents. Benign tumors should be treated by laparoscopic resection, while borderline or malignant tumors require individualized treatment of tumors and fertility-sparing treatments.

Bedside echocardiography for diagnosis of intracardiac cement embolism after percutaneous vertebroplasty: A case report

This case report is to demonstrate that a female patient had suddenly become unconscious 14 hours after percutaneous vertebroplasty. Bedside echocardiogram showed that the patient had a strong echo in the right heart with a small amount of pericardial effusion. CT showed high density in the distal branches of both pulmonary arteries and a high density in the right heart. With the help of that, the doctor made the diagnosis of intracardiac cement embolism in a very short time. The bone cement in the heart was removed under emergency cardiopulmonary bypass, then the patient was discharged smoothly.

A Universal Automatic Bottom Tracking Method of Side Scan Sonar Data Based on Semantic Segmentation

Determining the altitude of side-scan sonar (SSS) above the seabed is critical to correct the geometric distortions in the sonar images. Usually, a technology named bottom tracking is applied to estimate the distance between the sonar and the seafloor. However, the traditional methods for bottom tracking often require pre-defined thresholds and complex optimization processes, which make it difficult to achieve ideal results in complex underwater environments without manual intervention. In this paper, a universal automatic bottom tracking method is proposed based on semantic segmentation. First, the waterfall images generated from SSS backscatter sequences are labeled as water column (WC) and seabed parts, then split into specific patches to build the training dataset. Second, a symmetrical information synthesis module (SISM) is designed and added to DeepLabv3+, which not only weakens the strong echoes in the WC area, but also gives the network the capability of considering the symmetry characteristic of bottom lines, and most importantly, the independent module can be easily combined with any other neural networks. Then, the integrated network is trained with the established dataset. Third, a coarse-to-fine segmentation strategy with the well-trained model is proposed to segment the SSS waterfall images quickly and accurately. Besides, a fast bottom line search algorithm is proposed to further reduce the time consumption of bottom tracking. Finally, the proposed method is validated by the data measured with several commonly used SSSs in various underwater environments. The results show that the proposed method can achieve the bottom tracking accuracy of 1.1 pixels of mean error and 1.26 pixels of standard deviation at the speed of 2128 ping/s, and is robust to interference factors.

Study on Radar Echo-Filling in an Occlusion Area by a Deep Learning Algorithm

Radar beam blockage is an important error source that affects the quality of weather radar data. An echo-filling network (EFnet) is proposed based on a deep learning algorithm to correct the echo intensity under the occlusion area in the Nanjing S-band new-generation weather radar (CINRAD/SA). The training dataset is constructed by the labels, which are the echo intensity at the 0.5° elevation in the unblocked area, and by the input features, which are the intensity in the cube including multiple elevations and gates corresponding to the location of bottom labels. Two loss functions are applied to compile the network: one is the common mean square error (MSE), and the other is a self-defined loss function that increases the weight of strong echoes. Considering that the radar beam broadens with distance and height, the 0.5° elevation scan is divided into six range bands every 25 km to train different models. The models are evaluated by three indicators: explained variance (EVar), mean absolute error (MAE), and correlation coefficient (CC). Two cases are demonstrated to compare the effect of the echo-filling model by different loss functions. The results suggest that EFnet can effectively correct the echo reflectivity and improve the data quality in the occlusion area, and there are better results for strong echoes when the self-defined loss function is used.

Development of remote HF wave receiver in the backlobe direction of the SuperDARN Hokkaido East radar: Initial observations

We have been operating remote high frequency (HF) wave receivers for the SuperDARN Hokkaido East radar in Nagoya (1092 km away from the radar) and Rikubetsu (a few tens of m away from the radar antenna) since 2014 to monitor the ionospheric environment and its changes. One receiver set consists of a USRP-N210 receiver unit, Ubuntu Linux PC and dipole/loop antenna. Using the remote receiver data it is possible to monitor the upward/downward motion of the ionosphere at the ionospheric reflection point of the HF radar backlobe beams emitted toward the Nagoya area. The usage of the SuperDARN (backlobe) beams has the following advantages over other instruments such as HF Doppler systems: (1) SuperDARN Backlobe beams also have high directivity, so that it is possible to observe strong echoes at the remote area more than 1000 km away from the radar. (2) Since the SuperDARN radars emit pulse waves instead of continuous waves, it is possible to identify the travel time from the radar to the receiver. The initial results of the observation of ionospheric perturbations using the remote HF wave receiver of the SuperDARN Hokkaido East radar are described.

A five-year climatological lightning characteristics of linear mesoscale convective systems over North China

The lightning characteristics of 89 linear mesoscale convective systems (MCSs) occurred over the Beijing area from the year of 2007 to 2011 were analyzed by lightning data and S-band radar information. According to different morphology of radar echo, linear MCSs were classified into six categories: leading convective lines with a trailing stratiform region (TS for short), leading stratiform region with a trailing convective region (LS), leading convective lines with no stratiform region (NS), bow echo of leading lines (BE), leading convective lines with a parallel stratiform region (PS), and broken line stratiform (BL). The results showed that linear MCSs occurred frequently over the Beijing area at the summer time, in particular, TS, LS and PS modes totally accounted for 73% of linear MCSs. On the average, lightning mainly concentrated in the linear convective region, and small amount of lightning occurred in the stratiform region. At the mature stage, lightning mainly located in the linear convective region with strong radar echo of TS, LS, and PS MCSs. At the dissipating stage, the lightning gradually increased in the stratiform region of TS MCSs, whereas fewer lightning occurred in the mode of LS MCSs, and positive cloud-to-ground (+CG) lightning accounted for a large percentage in the mode of PS MCSs. From the distribution of +CG/CG in three archetypes of linear MCSs, it is found that PS MCSs with highest the proportion of +CG/CG, and then followed by LS MCSs while the lowest ratio appeared in TS MCSs. The relationship between lightning frequency and volume of 40 dBZ radar echo exhibited linear correlation in three distinct archetypes of linear MCS. Environmental factors of linear MCSs exhibited that high CAPE (Convective Available Potential Energy) value and the larger wind shear of 0–6 km played an important role to sustain the convective development of TS, LS and PS MCSs.

Analysis and Evaluation of Ultrasound Imaging Features and Pathological Results of Ovarian Cancer

To compare and analyze the relationship between the characteristics of ultrasound images of ovarian cancer and the results of postoperative pathological examination. A retrospective analysis of 206 patients with suspected ovarian cancer confirmed by surgical pathology was taken as the research object. The location, size, morphology, partition and wall nodules, cystic solidity, and signal characteristics of the tumor were observed and compared with the results of postoperative pathological examination evaluation and analysis to improve the early clinical diagnosis of ovarian cancer patients. By regression analysis of the histological examination of patients with ovarian tumors of different ages and the proportion of cox postoperative recurrence risk regression models, 154 of 206 ovarian tumor patients were ovarian cancer. There were significant differences in pathological types, lesion locations, maximum diameter lengths, and internal echo in patients with ovarian malignant tumors at different ages (p < 0.05). Ultrasound of ovarian cancer shows that the tumor has large tumor body, strong echo, cyst wall has protrusions, and peripheral and internal blood flow that is mainly high-speed and low-resistance. The sensitivity, specificity, and accuracy of ultrasound for ovarian cancer diagnosis are 84.38%, 66.67%, 81.01%. The accuracy, specificity, and sensitivity of early diagnosis of clinical ovarian cancer patients by ultrasound imaging features provide sufficient imaging evidence to further promote the clinical judgment of benign and malignant tumors, which is beneficial to doctors’ clinical treatment of ovarian cancer patients. The early diagnosis and the higher clinical value were shown.

Surgical Removal of a Gigantic Retroperitoneal Fetus in Fetu: One Case Report

AbstractFetus in fetu (FIF) is a rare congenital disorder. At present, the mechanism of FIF has not been fully elucidated. Clinically, the most common site of FIF is the abdominal cavity, while other sites have also been reported, such as from the scrotum to the intracranial space. Surgery is the best treatment for FIF. Our case is a 1-month-old girl. The mother’s ultrasound examination at 36 weeks of gestation revealed that the solid part of the abdominal mass showed strong echoes of the limbs, and the fetus was about 40 mm long. The diagnosis was a parasitic fetus in the fetus. The child was admitted to our hospital for mass resection 1 month after birth, and the tumor was confirmed as a parasitic fetus by postoperative pathology. At present, the patient has had no recurrence after surgery for 5 years. Adequate preoperative evaluation combined with radical surgical resection is an effective strategy for the treatment of parasitic fetuses.

An automatic identifying method of the squall line based on Hough transform

The squall line is a linear mesoscale convective system often seen in summer, which could bring severe disasters, such as thunderstorms, hails and tornadoes. So, the identification and forecast of squall lines are the important and difficult problems in operational weather nowcasting. In this paper, based on weather radar data an automatic identifying method of the squall line is presented. After image de-noising, extraction of the central axis of strong echo areas, and the Hough Transform, the spatial form and intensity variation characteristics of the reflectivity factors in the radar image are analyzed. On this basis, the automatic identification of squall line could be achieved. This method can overcome the adverse effects of the discontinuity of strong echo areas on the automatic identification of squall lines. The verification of squall line cases shows that the successful identification rate of squall lines is over 95%. Especially, when the boundary of the strong echo area is clear and is in a straight line or minor arc, the identification rate is higher. Overall, this new method has realized the automatic identification of squall lines on radar images, which could greatly improve the accuracy and time-effectiveness of squall line identification, and could provide a solid basis for the automatic forecast of squall lines in operational weather nowcasting.

El Auto de la residencia del Hombre como proceso judicial del pecador

Perteneciente al Códice de autos viejos, el Auto de la Residencia del Hombre nos muestra al Hombre compareciendo ante el tribunal de Justicia. Como esta actúa en íntima unión con Misericordia, esta colaboración de dos atributos distintos de Dios posibilita su perdón. La exaltación final de la Encarnación y de la Redención, característica del Procès de Paradis, se sustituye aquí por la de la Eucaristía. En cuanto al Hombre, tras haber aceptado una sentencia que le exime de una temida condena, se declara convencido de que el socorro de la gracia suficiente le permitirá salvarse. Por ello, el debate entre libertad y gracia permanece aquí implícito, sin que el desenlace se haga el eco de la polémica entre jesuitas y dominicos que iba a desencadenarse al final del siglo XVI.