Loop Type Research Articles

Research progress of lock-in amplifiers

The lock-in amplifier can perform high-precision measurement in both time and amplitude dimensions, so that it becomes a key component of instrumental system for precision measurement and control. This article overviews the concept, technology, and application of phase-locked amplifiers as a guide. It first explains the development and evolution of phase-locked amplifiers of analog, digital, and virtual phase-locked amplifiers, demonstrating their relationship and differences. Then, it classifies phase-locked amplifiers from a mathematical perspective based on the order and type of phase-locked loops. Subsequently, the testing process and metrological calibration progress of the main performance of phase-locked amplifiers, such as amplitude, frequency, and phase noise, are introduced. The conversion relationship between key indicators such as phase noise, time-domain jitter, Allan variance, and the coupling relationship with amplitude noise are discussed. Finally, the application forms and effects of phase-locked amplifiers in the fields of spectral enhancement, impedance analysis, magnetic measurement, microscopic imaging, and space exploration are listed. Through some new applications, the prospects of their transition from scientific instruments to industrial and even civilian products through intelligent computing, precise IoT, and other means are briefly given.

Research on Fire Alarm System Based on Entropy Power Method and Topsis Superiority and Inferiority Solution Distance Method

According to the statistics of China Fire and Rescue Bureau, in 2021, 748,000 fires were reported to the national fire and rescue teams, with 1,987 deaths, 2,225 injuries and direct property losses of 6.75 billion yuan. The loss of these innocent lives and the loss of a large amount of property make us think while deploring: is there a more effective, scientific and accurate way to prevent the great harm caused by the occurrence of fire. The fire alarm system studied in this paper can be used to reduce the hazards. Firstly, the number of real fires is given 430 times by using three indicators of fire occurrence: address, machine number and loop. After selecting the high-frequency parts in the loop, machine number and component type respectively and finding their corresponding false alarm rate and failure rate, the evaluation weights are obtained using the entropy weight method. A comprehensive evaluation model based on the entropy weight method is established to score each major component. Two most reliable components of the fire alarm system are obtained: the intelligent photoelectric probe and the manual alarm button. Next, the normalized management level of each fire brigade needs to be analyzed. First, the five important parameters of normalized average coverage rate, normalized component reliability, normalized component failure rate, normalized jurisdictional fire frequency (times/hour), and normalized false alarm rate are derived for each fire brigade. The comprehensive score index of each brigade was derived and ranked by the Topsis superiority and inferiority solution distance method, and it was concluded that M brigade, L brigade, and F brigade were the three jurisdictions with the lowest comprehensive management level.

Leukoaraiosis and Dizziness: Are They Related? – A Case Series

Dizziness and imbalance are one of the most common complaints seen in elderly people. Age-related ischemic diseases have varying degrees of manifestations and imbalance problems. Cerebral small vessel white matter disease has recently been a topic of interest in view of its association with geriatric syndromes–development of cognitive decline, dementia, falls, etc., but the association between small vessel disease and dizziness has not established clearly yet. Magnetic resonance imaging (MRI) brain is the most commonly used imaging modality for neurological disorders. White matter hyperintensities (WMHs) on T2-weighted sequences on MRI are known as leukoaraiosis (LA) and are suggestive of small vessel white matter disease and represent a high risk of cerebral, cerebellar, and brainstem stroke. The purpose of the present study is to investigate the correlation between unexplained vertigo and radiological changes of LA (small vessel disease) and videonystagmography (VNG) findings of such patients. First patient, a 55-year-old male patient had complaints of short-lasting episodes of spinning sensation and imbalance for the past 2 years. MRI brain showed small vessel ischemic changes (leukoaraiosis) with right vascular loop type 3 (anterior inferior cerebellar artery) without compressive symptoms. VNG showed broken smooth pursuit in horizontal and vertical planes; a hypometric saccades tracing in both planes and microsaccadic oscillations in spontaneous gaze. Second patient, a 60-year-old male had recurrent episodes of vertigo for the past 15 years. His VNG showed micro-oscillations in the saccades and impaired smooth pursuit. MRI revealed bilateral symmetrical T2 FLAIR hyperintensities in white matter and lateral ventricles. Third patient, a 69-year-old female presented with giddiness, nausea, and vomiting for 5 days. Pure-tone audiogram showed mild sensorineural hearing loss. MRI brain showed diffuse cerebral atrophy with small vessel ischemic changes. VNG showed impaired smooth pursuit and microsaccadic oscillations when the gaze was fixed. All three patients were managed successfully by vestibular rehabilitation and antioxidants and Coenzyme Q10. Through this study, we would like to highlight the possibility of a relation between leukoaraiosis and unexplained dizziness among elderly patients.

Классификация бляшек предскифской эпохи могильника Заюково-3

This article presents the classification of one of the most common categories of burial equipment of the North Caucasus population during the pre-Scythian time: sewn plaques. These ornaments made of bronze and antimony were found at the Zayukovo-3 burial ground in the burials of the VIII–VII centuries BC. Departments are allocated based on the material, sub–departments accord-ing to the shape of the surface, types – according to the manufacturing technique. The place of plaques in the burial shows that none of the selected jewelry was used as buttons and the attribu-tion of plaques to such is a historiographical mistake. Most of the studied plaques (except for bronze hemispherical ones with a jumper (type Ia1a1) and a loop (type Ia2a) on the back, cease to exist in the middle of the VII century BC. Thus, the remaining plaques are a chrono-indicator of the terminus ante quem of the finale of the classical stage of the Koban culture and the beginning of the Scythian time.

Forecasting the concentration of NO2 using statistical and machine learning methods: A case study in the UAE

Nitrogen dioxide (NO2) is the most active pollutant gas emitted in the industrial era and is highly correlated with human activities. Tracking NO2 emissions and predicting their concentrations represent important steps toward controlling pollution and setting rules to protect people's health indoors, such as in factories, and in outdoor environments. The concentration of NO2 was affected by the COVID-19 lockdown period and decreased because of restrictions on outdoor activities. In this study, the concentration of NO2 was predicted at 14 ground stations in the United Arab Emirates (UAE) during December 2020 based on training over a full time period of two years (2019–2020). Statistical and machine learning models, such as autoregressive integrated moving average (ARIMA), seasonal autoregressive integrated moving average (SARIMA), long short-term memory (LSTM), and nonlinear autoregressive neural network (NAR-NN), are used with both open- and closed-loop architectures. The mean absolute percentage error (MAPE) was used to evaluate the performance of the models, and the results ranged from “very good” (MAPE of 8.64% at the Liwa station with the closed loop) to “acceptable” (MAPE of 42.45% at the Khadejah School station with the open loop). The results show that the predictions based on the open loop are generally better than those based on the closed loop because they yield statistically significantly lower MAPE values. For both loop types, we selected stations exhibiting the lowest, medium, and highest MAPE values as representative cases. In addition, we demonstrated that the MAPE value is highly correlated with the relative standard deviation of NO2 concentration values.

Saleyard Bridge, UK – an improved approach to precasting steel–concrete composite bridge decks

Saleyard Bridge carries the A465 Heads of the Valleys Road over the River Clydach near Gilwern, Monmouthshire, UK. It comprises a 67 m single-span steel–concrete composite multi-girder superstructure made integral with the abutments. A full-depth precast deck was chosen to tackle site constraints and improve constructability. The alternative precast panel connection detail developed used straight laps to overcome the problems that can arise from using typical U-bar loop type connections between precast deck panels. The successful use of the precast panels proved that a deck design with straight laps was a practical alternative. The ability to increase the multi-beam centres and avoid cantilever edge formwork created a more economical solution with savings estimated at £500 000. The paper examines the detailed design and construction planning needed to realise the savings and speed up construction as well as improving site safety. The lessons learnt are also applicable to the wider use of precast panels as an alternative to in situ concreting.

Are citizens engaging with government social media Covid 19 pandemic information? Why media richness and dialogic loop features matter

AbstractThis study investigated the extent to which media richness, dialogic loop, and content type affect citizen engagement with local government social media information on the Covid‐19 pandemic. Quantitative content analysis through scraping of Facebook posts by the local government was employed in this study. Effects of the determinant variables was tested using negative binomial regression. Results show that both media richness and dialogic loop have significant and positive effects on citizens' engagement. This means that the richer the media, and the more dialogic features present in a Facebook post, the higher the turnout of reactions, shares, and comments of such post. Content type, on the other hand, was found to have no significant effect, implying that the number of content categories a certain post belongs to does not influence engagement from citizens. The study focused only on the local government's pandemic information posted on Facebook. Local governments should continue utilizing social media in disseminating pandemic information, and in the process, consider maximum utilization of the social media features to generate more engagement from its citizens. This study is the first to determine the factors affecting citizen engagement with government social media during the Covid‐19 pandemic in the Philippine context.

Emission of gravitational waves by superconducting cosmic strings

We study the gravitational radiation emission efficiency Γ of superconducting cosmic strings. We demonstrate, by using a solvable model of transonic strings, that the presence of a current leads to a suppression of the gravitational emission of cusps, kinks and different types of loops. We also show that, when a current is present, the spectrum of emission of loops with cusps is exponentially suppressed as the harmonic mode increases, thus being significantly different from the power law spectrum of currentless loops. Furthermore, we establish a phenomenological relationship between Γ and the value of the current on cosmic strings. We conjecture that this relation should be valid for an arbitrary type of current-carrying string. We use this result to study the potential impact of current on the stochastic gravitational wave background generated by cosmic strings with additional degrees of freedom and show that both the amplitude and shape of the spectrum may be significantly affected.

G-quadruplex DNA: A Longer Story.

G-quadruplexes (G4s) are distinctive four-stranded DNA or RNA structures found within cells that are thought to play functional roles in gene regulation and transcription, translation, recombination, and DNA damage/repair. While G4 structures can be uni-, bi-, or tetramolecular with respect to strands, folded unimolecular conformations are most significant in vivo. Unimolecular G4 can potentially form in sequences with runs of guanines interspersed with what will become loops in the folded structure: 5'GxLyGxLyGxLyGx, where x is typically 2-4 and y is highly variable. Such sequences are highly conserved and specifically located in genomes. In the folded structure, guanines from each run combine to form planar tetrads with four hydrogen-bonded guanine bases; these tetrads stack on one another to produce four strand segments aligned in specific parallel or antiparallel orientations, connected by the loop sequences. Three types of loops (lateral, diagonal, or "propeller") have been identified. The stacked tetrads form a central cavity that features strong coordination sites for monovalent cations that stabilize the G4 structure, with potassium or sodium preferred. A single monomeric G4 typically forms from a sequence containing roughly 20-30 nucleotides. Such short sequences have been the primary focus of X-ray crystallographic or NMR studies that have produced high-resolution structures of a variety of monomeric G4 conformations. These structures are often used as the basis for drug design efforts to modulate G4 function.We believe that the focus on monomeric G4 structures formed by such short sequences is perhaps myopic. Such short sequences for structural studies are often arbitrarily selected and removed from their native genomic sequence context, and then are often changed from their native sequences by base substitutions or deletions intended to optimize the formation of a homogeneous G4 conformation. We believe instead that G-quadruplexes prefer company and that in a longer natural sequence context multiple adjacent G4 units can form to combine into more complex multimeric G4 structures with richer topographies than simple monomeric forms. Bioinformatic searches of the human genome show that longer sequences with the potential for forming multiple G4 units are common. Telomeric DNA, for example, has a single-stranded overhang of hundreds of nucleotides with the requisite repetitive sequence with the potential for formation of multiple G4s. Numerous extended promoter sequences have similar potentials for multimeric G4 formation. X-ray crystallography and NMR methods are challenged by these longer sequences (>30 nt), so other tools are needed to explore the possible multimeric G4 landscape. We have implemented an integrated structural biology approach to address this challenge. This approach integrates experimental biophysical results with atomic-level molecular modeling and molecular dynamics simulations that provide quantitatively testable model structures. In every long sequence we have studied so far, we found that multimeric G4 structures readily form, with a surprising diversity of structures dependent on the exact native sequence used. In some cases, stable hairpin duplexes form along with G4 units to provide an even richer landscape. This Account provides an overview of our approach and recent progress and provides a new perspective on the G-quadruplex folding landscape.

Dermoscopic Findings of Alopecia in Patients with Hypothyroidism.

Thyroid hormones are essential for the growth and maintenance of hair follicles. Numerous studies have evaluated the relationship between thyroid disorders and hair loss. However, no study has assessed the dermoscopic results in patients with hypothyroidism and hair loss. This study aimed to investigate dermoscopic findings of alopecia in patients with hypothyroidism. This analytic cross-sectional study was performed on patients with hair loss referred to dermatology clinics of Guilan University of Medical Sciences, Iran. Hypothyroid patients and an equal number of euthyroid individuals were compared. After recording the demographic and clinical characteristics, all patients were subjected to hair dermoscopy. A total of 164 patients with and without hypothyroidism with hair loss were studied. The frequency of hair shaft abnormalities (P < 0.001) and vellus hair (P < 0.001) significantly differed between the two groups. Dermoscopic findings related to scale abnormalities (P = 0.002) and their perifollicular type (P < 0.001) significantly differed between the groups. Vascular changes (P < 0.001), perifollicular concentric type (P = 0.012), and interfollicular red loops type (P = 0.005) were significantly higher in patients with hypothyroidism. Also, based on the multiple logistic regression model, the chance of abnormalities of the hair shaft, scales, and vascular changes increased by 3.24, 2.73, and 3.53, respectively, in hypothyroidism compared to euthyroidism. Regarding the promising results of this study, we could detect possible dermoscopic signs of inflammation in hypothyroid patients with hair loss. Further investigations are needed because there is a shortage of evidence on this novel diagnostic method.

Positive feedback promotes terrestrial emergence behaviour in an amphibious fish.

Major ecological transitions such as the invasion of land by aquatic vertebrates may be facilitated by positive feedback between habitat choice and phenotypic plasticity. We used the amphibious fish Kryptolebias marmoratus to test the hypothesis that aquatic hypoxia, emergence behaviour and respiratory plasticity create this type of positive feedback loop that causes fish to spend increasing amounts of time on land. Terrestrially acclimated fish were more sensitive to aquatic hypoxia (emergence at higher PO2) and were less hypoxia tolerant (shorter time to loss of equilibrium) relative to water-acclimated fish, which are necessary conditions for positive feedback. Next, we tested the prediction that exposure to aquatic hypoxia causes fish to emerge frequently, reduce gill surface area, and become less hypoxia tolerant. Indeed, fish exposed to severe aquatic hypoxia spent almost 50% of the time out of water and coverage of the gill lamellae by an inter-lamellar cell mass almost doubled. Fish exposed to aquatic hypoxia that could emerge from water were also more sensitive to subsequent acute aquatic hypoxia and were less hypoxia tolerant than normoxia-exposed controls. These results are opposite those of fish that cannot escape from aquatic hypoxia and presumably arise owing to plastic changes that occur during air exposure. Together, these results indicate that emergence behaviour begets further emergence behaviour, driven by gill remodelling which reduces aquatic respiratory function. This type of positive feedback may explain how amphibious behaviour has repeatedly evolved in fishes that occupy hypoxic aquatic habitats despite the associated challenges of life on land.

Basis and Principles of Systematic Thinking in Education

This research is a literature study that examines the basic principles and principles of systematic thinking in education. background of the need for systematic thinking in the world of education, the results of the study show that in systems thinking, this structure (a set of causal circles) determines the behavior (behavior or dynamics) of a phenomenon. A positive causal circle will result in a growth or decline behavior. Positive causal loops are also known as Reinforcing loop types or use the "R" notation. Meanwhile, a negative causal circle will result in a goal-seeking behavior, although sometimes the goals or objectives in the circle are not seen explicitly. The negative causal circle is also a balancing process using the notation "B".

Enhanced performance of magnetoelectric voltage coefficient in giant magnetostrictive (Ni0.7Mg0.3Fe2O4)/piezoelectric (BaZr0.2Ti0.8O3) composites

The non-toxic lead-free multiferroic composite samples Ni0.7Mg0.3Fe2O4/BaZr0.2Ti0.8O3 were synthesized by using standard double sintering ceramic method. The composite samples are found to exhibit dielectric response, which might be associated with Maxwell-Wagner type interfacial polarization and Koop's phenomenological theory. The variation of DC conductivity with respect to temperature revealed the conduction of electrons i.e. due to the small polarons hopping mechanism. The synthesized ME composite samples show a representative magnetic hysteresis (M − H) loop type behaviour at room temperature. In a previous report, the response of ME voltage coefficient 4.262 mVcm-1.Oe was determined for (30%) Ni0.8Mg0.2Fe2O4 + (70%) BaZr0.2Ti0.8O3 composites at 5.0 kOe applied DC magnetic field. But in this report, we improved the ME voltage coefficient for the composition 50% (Ni0.7Mg0.3Fe2O4) + 50% (BaZr0.2Ti0.8O3) which is a lead-free ME composite with the massive ME voltage coefficient of 8.562 mV/cm.Oe was achieved. Hence, the estimated results can provide experimental guidance for the optimal design of high-performance magnetoelectric devices and render better support for the technological development in the field of magnetoelectricity.

Recursive algorithms for identification of dual Youla-Kucera parametrized plant models in closed loop

The growing interest in using dual Youla Kucera plant parametrization for modeling plant uncertainties raises the need for recursive identification algorithms dedicated to the identification of these structures in closed loop in view of developing appropriate iterative tuning and adaptive control strategies. The paper presents recursive algorithms for identification in closed loop of dual Youla-Kucera parametrized plant models. These algorithms assure global asymptotic stability in the deterministic environment and allow to obtain unbiased parameter estimation in the presence of measurement noise when the plant model is in the model set. The paper also re-visit the Hansen scheme which allows to associate open loop type recursive identification algorithms for the identification of these structures in closed loop. When the plant model is not in the model set, comparison of the various algorithms is done in terms of the bias distribution. Further comparisons and performance evaluation is provided by simulations on some relevant examples and experimental identification in closed loop of a test bench for active noise control.

Evaluation of control strategies applied in small-scale photovoltaic solar tracking systems: a review

This work evaluates the control algorithms applied to decentralized photovoltaic solar tracking systems. For this, the control strategies are divided into three: open loop, closed loop and hybrid loop. Each strategy is screened for its suitability as a suitable technology for small-scale applications, defined by meeting a set of eleven attributes. A specialized literature review process was developed specifically to present the potential of each control algorithm strategy, through an evaluation matrix. The analysis of the algorithms and attributes was carried out using the formal methodology of concept analysis. To facilitate the processing of the information, free access software called “concept Explorer” is used. The analysis carried out shows that open loop control algorithms currently have a greater application in one and two-axis solar tracking systems. Additionally, the on-off control is the one with the greatest application for the three types of control loops evaluated. Finally, the applied methodology has proven to be useful for the evaluation of information and serves as a reference, to carry out analyzes that group and link different alternatives as a model for evaluating a deterministic set of attributes.

Coordinated Control of Hybrid DERs Enabled Grid-Interactive Residential PCM With Hybrid Bus Layout

This article proposes a multi-terminal grid interactive power conditioning module (PCM) for integration of hybrid distributed energy resources (DERs) within single phase residential premises, along with the Energy Storage Stacks (ESSs). The PCM also features hybrid bus layouts with medium-low voltage dc (MVdc) and low voltage dc (LVdc), for dc load integrations, and ac bus layout for single phase ac loads. The bi-directional MVdc and LVdc bus facilitate the effective power management and bus voltage support. It operates in all grid feeding, forming and supportive modes. The ESSs includes battery for system energy management and the supercapacitor for dc bus stabilization during transient conditions. The coordinated control of the PCM is capable of interfacing multiple DERs, dc/ac loads, and ESS. The controllers in the PCM are self-adaptive to the frequent islanding situations and ensure the system stability with minimum use of sensory feedbacks. The PCM has loop type dc bus feeder to make residential system operative during transient/faulty conditions. Simulation results verify the feasibility of the proposed system in all active and passive grid feeding; and grid forming modes and experimental setup is used to test the performance of the proposed PCM control through a single microcontroller.

Board games for the study of flow charts

The article presents the description of method of the study of flow charts using board games.The playing field in such a game is a flow chart. During the game, students roll the dice and move the chip around the playing field, depending on the number that has fallen. But at the same time, they must comply with the rules for the execution of the algorithmic structures included in the flow chart.The purpose of the proposed teaching method is to intensify the learning of educational material. This is especially important for informatics with its extremely fast rates of development.For the game, the class is divided into teams of 2–4 people. All teams play at the same time. During the game, each participant repeatedly goes through all the studied algorithmic constructions. Thus, one hundred percent coverage of students and repeated repetition of the material is achieved.Due to this, it becomes possible to advance far enough in the study of algorithmic constructions. In addition to traditional forks and two types of loops (with a precondition and with a given number of repetitions), input commands, subprograms and parameters are studied.The methodic were prepared as part of the Perm version of the propaedeutic course of informatics (team of authors: M. A. Plaksin, N. G. Ivanova, O. L. Rusakova; the working title of the course is "TRIZformatika"). But the technique can be applied in any other course. The article provides a description and playing fields of four board games for mastering the mechanism of flow charts, and also gives a number of methodological comments.

Anatomical pancreatic variants in intraductal papillary mucinous neoplasm patients: a cross-sectional study

BackgroundNo previous studies have examined the possible relationship between intraductal papillary mucinous neoplasm (IPMN) and the developmental ductal variations of the pancreas, such as an ansa pancreatica and a meandering main pancreatic duct (MMPD).MethodsThis retrospective cross-sectional study enrolled 214 patients, 108 with IPMN disease and 106 subjects from a community at the tertiary care unit. The main pancreatic duct (MPD) was evaluated in the head of the pancreas by its course, which were non-MMPD: descending, vertical, and sigmoid, or MMPD including loop types, reverse-Z subtypes, and an N-shape, which was identified for the first time in this study. IPMN patients were also evaluated for worrisome features (WF) or high-risk stigmata (HRS), and the extent of IPMN cysts.ResultsAmong IPMN patients, 18.4% had MMPD, which we observed in only 3.0% of the control group (P < 0.001). Patients with MMPD were more likely to belong to the IPMN group compared with non-MMPD patients [odds ratio (OR) 6.4, 95% confidence interval (CI) 2.2–24.9]. Compared with a descending shape MPD, IPMN patients with an N-shaped MPD were more likely to have a cystic mural nodule (OR 5.9, 95% CI 1.02–36.0). The presence of ansa pancreatica associated with more extent IPMN disease (OR 12.8, 95% CI 2.6–127.7).ConclusionsIPMN patients exhibited an MMPD more often than control patients. Ansa pancreatica associated with multiple cysts. Furthermore, an N-shape in IPMN patients associated with cystic mural nodules, suggesting that this shape serves as a risk factor for more severe IPMN.

Classification and unified phenomenological modeling of complex uniaxial rate-independent hysteretic responses

The number and nature of hysteretic responses typically exhibited by mechanical systems and materials are so huge that their modeling and identification are usually carried out on an ad-hoc basis. Thus, with the aim of proposing a unified approach to the modeling of rate-independent hysteretic behavior, we first perform a detailed classification of complex generalized force–displacement hysteresis loops, ranging from the asymmetric, pinched, S-shaped, flag-shaped ones to those obtained by their arbitrary combination, since they typically span the vast majority of loops obtained experimentally. Subsequently, we formulate a novel rate-independent hysteretic model, having an exponential nature, that offers a series of advantages over other hysteretic models available in the literature. Indeed, it adopts closed form expressions for evaluating the output variable, with important benefits in terms of computational efficiency and implementation ease, and it allows for an uncoupled modeling of the generic loading and unloading phases by means of two different sets of eight parameters. In addition, it requires the use of a simple identification procedure thanks to the clear theoretical and/or experimental interpretation of the adopted parameters. The accuracy of the proposed model is experimentally and numerically validated and its computational efficiency is demonstrated. In particular, the experimental validation is carried out by reproducing four different types of complex experimental hysteresis loops retrieved from the literature, whereas the numerical validation is performed by running some nonlinear time history analyses on a single degree of freedom mechanical system and comparing the results with those obtained by using a modified version of the celebrated Graesser–Cozzarelli model.

The "Deep Subarcuate Fossa" sign and three types of anomalous subarcuate loops encountered during vestibular schwannoma removal.

An anomalous subarcuate loop (SL) of the anteroinferior cerebellar artery (AICA) is a rare anatomic variation, which increases the complexity and risk of vestibular schwannoma (VS) removal. However, preoperative diagnosis of this anomaly remains difficult. The aim of this study was to report three types of anomalous SLs encountered during VS removal and to describe the "Deep Subarcuate Fossa (SF)" sign and its significance in the diagnosis and treatment of an osseous-penetrating SL. We prospectively observed 963 patients with newly/recently diagnosed VS who underwent surgical treatment performed by the senior author (P.Z.) from 2012 to 2021 and identified 16 patients with an anomalous SL. The SF was retrospectively measured on preoperative thin-slice temporal bone computed tomography in 963 patients. Three types of anomalous SLs were encountered during VS removal: the apex of the SL was embedded in the dorsal tumor capsule (type I, 1 case), the dura (type II, 8 cases), or the dura and bone (type III, 7 cases) surrounding the SF. The depth of the SF in 7 patients with a type III anomalous SL ranged from 2.3 to 7.0mm (3.56 ± 1.56mm), which was significantly larger than that in 845 patients without an osseous-penetrating SL (1.23 ± 0.43mm) (p = 0.008). When the depth of the SF exceeded 2mm, the sensitivity and precision of the diagnosis of a type III anomalous SL were 100% (7/7) and 31.8% (7/22), respectively. Three types of anomalous SLs may be encountered during VS removal, and AICA displacement is recommended before tumor removal. The "Deep SF" sign may indicate the existence of a type III anomalous SL and it can predict the depth of the AICA in the bone and guide the drilling of the bone around the vessel loop.