Irregular Amplitude Research Articles

Nonlinear Rossby Wave–Wave and Wave–Mean Flow Theory for Long-term Solar Cycle Modulations

Abstract The Schwabe cycle of solar activity exhibits modulations and frequency fluctuations on slow timescales of centuries and millennia. Plausible physical explanations for the cause of these long-term variations of the solar cycle are still elusive, with possible theories including stochasticity of the alpha effect and fluctuations of the differential rotation. It has been suggested recently in the literature that there exists a possible relation between the spatiotemporal structure of the solar cycle and the nonlinear dynamics of magnetohydrodynamic (MHD) Rossby waves at the solar tachocline, including both wave–wave and wave–mean flow interactions. Here we extend the nonlinear theory of MHD Rossby waves presented in a previous article to take into account long-term modulation effects due to a recently discovered mechanism that allows significant energy transfers throughout different wave triads: the precession resonance mechanism. We have found a large number of Rossby–Hauwirtz wave triads whose frequency mismatches are compatible with the solar cycle frequency. Consequently, by analyzing the reduced dynamics of two triads coupled with a single mode (five-wave system), we have demonstrated that in the amplitude regime in which precession resonance occurs, the energy transfer throughout the system yields significant long-term modulations on the main ∼11 yr period associated with intratriad energy exchanges. We further show that such modulations display an inverse relationship between the characteristic wave amplitude and the period of intratriad energy exchanges, which is consistent with the Waldmeier law for the solar cycle. In the presence of a constant forcing and dissipation, the five-wave system in the precession resonance regime exhibits irregular amplitude fluctuations, with some periods resembling the grand minimum states.

Pseudorandom amplitude-phase-shift keyed signals with irregular bi-level amplitude spectrum for moving target detection

This paper considers the target locating against the clutter background in radars with quasi-continuous mode of transmission and reception on common aerial of signals with pseudorandom amplitude- and phase-shift keying. Pseudorandom amplitude-phase-shift keyed signals with irregular bi-level amplitude spectrum are proposed for use. The high-level spectrum components of returns from the moving and stationary targets can be partially overlapped. It is proposed to perform the frequency rejection of high-level components of the stationary targets before the correlation signal processing. As a result, significant part of the energy of interfering reflections is cut out and just a small part of the energy of the useful signal is lost. The signal-to-clutter ratio increases. The synthesis method of pseudorandom amplitude-phase-shift keyed signal with irregular bi-level amplitude spectrum is considered. The spectrum of the synthesized signals is analyzed. Increase of the signal-to-clutter ratio was obtained in the processing of signals with frequency interference rejection. The result of detection modeling of a moving target against the background of reflections from a stationary object is presented.

Comparison of quantitative analysis of hand movements with gyroscope between early stage Parkinson's disease and scans without evidence of dopaminergic deficit (SWEDD)

Scans without evidence of dopaminergic deficit (SWEDD) is a radiological nomenclature, which refers to patients with a normal dopamine transporter scan presumed to have parkinsonism. It is important to differentiate SWEDD from Parkinson's disease (PD) in the early stage of disease because they have similar clinical features. As bradykinesia is a cardinal clinical feature of parkinsonism, we quantitatively investigated detailed presentations of hand movement by using an angular measurement system in SWEDD and PD patients, and normal controls. Twenty-three patients with SWEDD, 23 patients with drug-naïve early stage PD, and 23 age-matched healthy controls participated in this study. Angular velocity was measured during finger-tapping and forearm-rotation movement for assessment of bradykinesia. RMS (root mean square) velocity and amplitude, and movement irregularity were derived from the gyro sensor signal. SWEDD patients presented a greater average speed, a larger average amplitude, and more irregular speed and amplitude only during forearm rotation compared to PD patients (p < .05). SWEDD patients also exhibited a smaller average speed and average amplitude, and a more irregular velocity usually during finger tapping compared to controls (p < .05). Quantitative variables of forearm rotation movement showed significant differences between SWEDD and PD patients, and quantitative variables of finger tapping movement showed a significant difference between SWEDD patients and the control group. These results suggest that quantitatively determined/assessed variables using biomedical engineering devices can distinguish SWEDD patients from PD patients as well as from normal subjects.

Acoustic characteristics of belching in speech

“When such nonspeech sounds occur connected in speech they sometimes carry important social connotations (Pike, 1943: 39).” This sentiment is attested over and over again in linguistic literature that provides cases of nontraditional sounds (such as coughing, moans, cries) being co-opted into the continuous stream of speech within discourse (Ohala,1995; Ogden, 2013; Prelock and Hutchins, 2018; Pinto and Vigil, 2018). This reveals an unanswered problem: While many of these sounds have been able to be expressed by their phonetic parameters in paralinguistics (Trager, 1958; Poyatos, 1975), belching—as evident from a case study as being intentionally interjected into the speech stream with social connotations (Kidner, 2018)—has consistently eluded detailed description using acoustic parameters. Acoustic data were taken from this case study, and belching was distinguished in Praat (Boersma and Weenik, 2018) from modal speech by an increase in glottal pulses and jitter (&amp;gt;4.4%), an increase in shimmer (&amp;gt;15%), low pitch (≤300 Hz), and an irregular amplitude contour. These criteria for belch identification (while not exhaustive) allow us not just to classify belches phonetically within the corpus, but moves the process of acoustically defining otherwise difficult paralinguistic sounds forward.

Selected aspects of motor vehicle dynamics on the example of a power-off straight line maneuver

In this paper the selected phenomena related to motor vehicle’s motion have been considered basing on a computer simulation. The vehicle performed a power-off straight line maneuver with different road conditions being included. All simulations have been performed in the MSC Adams/Car environment based on the available sports two-seater vehicle model, realizing the adopted maneuver at the instant speed of 100km/h. This enabled observation of the selected phenomena along the road long enough to relate them to different aspects of vehicle dynamics research. As for the randomly uneven road, almost similar and almost different profiles have been assumed for the left and right wheels of the vehicle. Additionally, two values of the coefficient determining the maximum amplitude of road irregularities have been selected: 0.3 for lower and 0.9 for higher irregularities, so the road surface conditions along with the flat road have been considered as one of the factors causing disturbances of the motor vehicle motion. Such research seems valuable from the point of view of road traffic safety and vehicle maintenance. This specific example is a presentation of the possible research on vehicle dynamics as well as a potential background for further considerations including different types of vehicles along with almost different road profiles for the left and right wheels of the given vehicle model. A power-off straight maneuver is not performed very often in normal road traffic. However, such test could be valuable when analyzing influence of the selected motor vehicle parameters, such as uneven loading, suspension characteristics, etc. on such maintenance features as stability, steerability and the influence of external disturbances acting on the moving vehicle. Further research provides different maneuvers and different simulation conditions.

Effect of Rail Irregularities on Ride Comfort of Train Moving Over Ballast-Less Tracks

Rail irregularities are the main factors influencing the ride comfort of trains moving over tracks. Despite various investigations made in this regard for the ballasted tracks, there is a lack of studies for the ballast-less tracks. This limitation is addressed in this study. To this end, a vehicle/slab-track interaction numerical model was developed, which was validated by comparison of the results obtained herein with those of the field tests carried out in this study. The effects of rail irregularities with various amplitudes and wavelengths on the ride comfort were studied by a comprehensive parametric analysis. Particularly, the effects of the wavelengths and amplitudes of rail irregularity on the ride comfort were investigated. Contrary to the current understanding, it was shown that rail irregularities with short wavelength have considerable effects on the ride comfort for the slab-tracks. In addition, the ride comfort decreases significantly when the wavelengths of rail irregularity become less than 0.75[Formula: see text]m in the metro lines. The critical speed of the train (at which the lowest ride comfort is obtained) was derived as a function of rail irregularity. The results obtained indicate that the amplitude of rail irregularity has negligible influence on the critical speed of the train.

Direct Evidence for the Dissipation of Small‐Scale Ionospheric Plasma Structures by a Conductive E Region

AbstractThe conductivity of the ionospheric E region is known to cause effective dissipation of plasma structures in the F region. We use 3.5 years of 16‐Hz sampling rate electron density measurements from the Swarm advanced data set to investigate seasonal dependencies of plasma structure dissipation. Using a novel algorithm to infer plasma structure dissipation through detection of spectral breaks in density fluctuation power spectra, we analyze 100,000 spectra based on data from Swarm A in both the northern and southern polar caps. For the first time, we can present long‐term development of small‐scale (∼1‐10 km) plasma structure diffusion in the high‐latitude ionospheric F region. We discuss possible reasons for these variations. This study presents evidence for the E region as an important factor in the seasonal variation of F region plasma irregularity amplitudes.

Effect of rail pad stiffness on the wheel/rail force intensity in a railway slab track with short-wave irregularity

In this paper, a two-dimensional numerical model is developed to investigate the effect of rail pad stiffness on the wheel/rail force in a slab track with harmonic irregularity. The model consists of a vehicle, nonlinear Hertz spring, rail, rail pad, concrete slab, resilient layer, concrete base, and subgrade. The rail is simulated using the Timoshenko beam element for considering the effects of high-frequency excitation produced by short-wave irregularity. The results obtained from the model are compared with those available in the literature and from the field to prove the validity of the model. Through a parametric study, the effect of variations in rail pad stiffness, vehicle speed, and harmonic irregularity on the wheel/rail force is investigated. For the slab track without any irregularity, the wheel/rail force is at maximum when the vehicle speed reaches the critical speed. As the rail pad stiffness increases, the critical speed increases. When the amplitude of irregularity is high, wheel jumping phenomenon may occur. In this situation, as the vehicle speed and rail pad stiffness are increased, the dynamic wheel/rail force is increased. In the low-frequency range, the wheel/rail force increases as the rail pad stiffness increases. In the high-frequency range, the wheel/rail force increases as the rail pad stiffness is decreased.

A spectral evolution model for track geometric degradation in train–track long-term dynamics

ABSTRACTIn this work, a new insight is put forward to characterise the evolution of track irregularities from viewpoint of spectral analysis. The main novelty lies in a proposal of regarding the geometric deterioration of track irregularities equivalently as the evolution of power spectral densities (PSD), and consequently, the stationarity of track irregularities and a robust dynamic assessment can be guaranteed. Besides a systematic framework integrating the train–track dynamic model, track irregularity PSD evolution model and the Pseudo-excitation method is developed to predict the uncertain responses of system components long-termly. In the PSD evolution method developed, we have departed from the conventional strategies trying to characterise the evolution of time-domain track irregularities from perspectives of physical-mechanical methods and elastic-plastic deformation. Instead, a statistical and mathematical model is proposed to randomly estimate the evolution of track irregularities with a guarantee of the stationarity of track geometries. In this model, the deterioration of time domain track irregularities is equivalently transformed as the evolution of PSD at frequency domain. A mathematical relationship between dynamic loads and PSD evolutions is constructed, in which the model parameters are defined by the statistical results and a Levenberg–Marquard iterative formula. Apart from predicting the long-term evolution of track irregularity amplitude and the track quality index, the PSD evolution model can be perfectly united with the train–track interaction model and a pseudo-excitation method to reveal the long-term evolution of system behaviours no matter on response amplitudes or on their characteristic frequencies against different confidence intervals.

A fully-packaged ship-shaped hybrid nanogenerator for blue energy harvesting toward seawater self-desalination and self-powered positioning

Lately, hybridization of triboelectric nanogenerator (TENG) has shown great potential in collecting ocean-wave energy with low frequency and irregular amplitude, and hybridization of TENG with electromagnetic generator (EMG) can enable the broadband energy harvesting with the fully-packaged design. Here, a ship-shaped hybridized nanogenerator (SHNG) consistsing of three TENGs and an EMG has been proposed, from which the TENGs works in freestanding rolling and contact-separation modes. In this design, the rolling of magnetic cylinder makes the TENG easy to be driven by water wave due to the low frictional resistance. Moreover, the unique structural design is beneficial to the packaging, ensuring the isolation of the SHNG from the external water environment and thus providing stable electrical output. Under an operating frequency of 2 Hz, the contact-separation TENG and EMG are able to produce a peak power of about 800 µW with a resistive load of 20 MΩ and 9 mW with a resistive load of 100 Ω, respectively. In terms of charging capacitors, the SHNG can achieve higher charging voltage and faster charging speed than that of the individual TENG or EMG. To accomplish impedance match between the TENG and EMG, a transformer was employed to decrease the impedance of the TENG. The SHNG has been demonstrated to effectively desalinate seawater, and its desalination rate reaches 29.4% in 3 h. The SHNG has also been proved to power a digital temperature-humidity meter and drive a radio-frequency emitter to form a self-powered wireless positioning system. This work not only renders an innovative approach toward effective blue energy harvesting, but also presents a great prospect for enabling self-desalination and self-powered marine rescue systems.

Improving a methodology of theoretical determination of the frame and directing forсes in modern diesel trains

The method for determining the directing force was improved, taking into consideration the effect of transverse creep forces and the angle of the directing force inclination to the vertical axis. It was established that when determining the directing force, it is necessary to check the gap between the wheel flange and the rail head which is difficult to realize without computer simulation. When determining the frame force on the axle of the wheel set, a comprehensive approach was adopted taking into account geometric irregularities of the track path, both in vertical and horizontal planes; longitudinal and transverse creep forces at the point of the wheel-rail contact and influence of adjacent wheel sets of the diesel train car. Dependences of the frame and directing forces on speed of the carriage movement and the value of amplitude of the horizontal irregularity of the rail track were obtained. It was established that when moving in the straight section of the track, an increase in speed from 0 m/s to 50 m/s results in a rise in the value of the frame force: up to 8.3 kN for the first wheel set and 19.37 kN for the second wheel set and the directing force up to 31.38 kN for the first wheel set and up to 46.83 kN for the second wheel set. The increase in amplitude of the horizontal irregularity of the track, which is one of the primary causes of occurrence of forced oscillations of the carriage section above the springs also leads to an increase in numerical values of the forces of interaction of the rolling stock with the rail track. All this can bring about an increased power influence of the wheel set on the track and a negative impact on the basic criteria of traffic safety. Influence of the carriage movement speed on the value of transverse creep forces was studied. It has been established that with an increase in the carriage speed from 0 m/s to 50 m/s, these forces grow from 0 to 15.75 kN for the 1 st wheel set and from 0 to 29.22 kN for the 2 nd wheel set. This indicates impermissibility of neglecting the transverse creep forces when determining the directing force. Comparison of numerical values of the directing force determined by different methodologies was performed. It has been established that the methodology used in conducting forensic examination of railroad accidents may result in underestimation of fulfillment of the derailing condition. At the same time, calculations according to the formula improved in this study give an opportunity to obtain the results most approximate to the real operation conditions. Comparison of the experimental and theoretical calculated values of the frame force acting on the first wheel set of the diesel train car was made and their practical coincidence was shown. Discrepancy of the compared values of the frame force was within 7.2 %

Railway noise annoyance modeling: Accounting for noise sensitivity and different acoustical features.

Noise annoyance due to railway traffic is a growing issue in today's society. This annoyance may be predicted using noise-exposure relationships with mean energy-based index. However, there is room for improvement of models as other acoustical and non-acoustical factors also influence noise annoyance responses. In this paper, it is proposed to highlight annoying auditory sensations evoked by the railway noise and determine acoustical and psychoacoustical indices combined in a predictive model. A laboratory experiment involving railway pass-by noise in urban areas was carried out. Annoyance ratings, noise sensitivity ratings, and free verbalization data were gathered. The analysis underlined annoying auditory sensations caused by railway pass-by noises. Two indices were proposed to account for irregular amplitude fluctuation and noise event duration-related sensations. A multilevel regression analysis was conducted, leading to two annoyance models considering noise indices and noise sensitivity. These models were finally compared to a similarly obtained multilevel regression model related to tramway noise annoyance. The comparison was carried out as a cross-validation considering the models and the respective datasets collected in laboratory conditions for model construction. Results showed that the railway noise annoyance model led to a good prediction of tramway noise annoyance and vice versa.

Climatology and Characteristics of Medium‐Scale F Region Ionospheric Plasma Irregularities Observed by COSMIC Radio Occultation Receivers

AbstractMedium‐scale ionospheric ionization structures are a persistent global feature of the Earth's ionosphere. Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation measurements are well suited to address the incomplete global observational picture of plasma density irregularities, including the global climatology in both bottomside and topside F region layers, and their structure in the vertical dimension. A climatological database of F region ionospheric irregularities and their characteristics has been developed through detection of total electron content perturbations by Global Positioning System receivers onboard COSMIC satellites. This paper presents global occurrence rates and detailed characteristics of equatorial to midlatitude medium‐scale irregularities under quiet geomagnetic conditions. The study covers 4 years, two during solar minimum (2008–2009) and two during the ascending phase of solar cycle 24 (2012–2013). Irregularities were found to occur frequently at high latitudes and during nighttime in equatorial to midlatitude regions in both bottom and topside F region layers. Longitudinal‐seasonal occurrence trends at equatorial and midlatitudes are consistent with previous irregularity climatology, which reaffirms that localized enhancements in plasma instability growth rates contribute to irregularity occurrence. Seasonal occurrence patterns also indicate a high occurrence of irregularities in regions corresponding to the solar terminator, confined primarily to altitudes below ~300 km. The local time‐altitude distributions of equatorial and midlatitude irregularity occurrence, amplitude, and scale size provide further insight into irregularity generation mechanisms, and include features consistent with “spread F” irregularities and traveling ionospheric disturbances.

Temperature-dependent virus lifecycle choices may reveal and predict facets of the biology of opportunistic pathogenic bacteria

Melioidosis, a serious illness caused by Burkholderia pseudomallei, results in up to 40% fatality in infected patients. The pathogen is found in tropical water and soil. Recent findings demonstrated that bacterial numbers can be regulated by a novel clade of phages that are abundant in soil and water. These phages differentially infect their bacterial hosts causing lysis at high temperatures and lysogeny at lower temperatures. Thus seasonal and daily temperature variations would cause switches in phage-bacteria interactions. We developed mathematical models using realistic parameters to explore the impact of phages on B. pseudomallei populations in the surface water of rice fields over time and under seasonally changing environmental conditions. Historical records were used to provide UV radiation levels and temperature for two Thailand provinces. The models predict seasonal variation of phage-free bacterial numbers correlates with the higher risk of melioidosis acquisition during the “warm and wet” season. We find that enrichment of the environment may lead to irregular large amplitude pulses of bacterial numbers that could significantly increase the probability of disease acquisition. Our results suggest that the phages may regulate B. pseudomallei populations throughout the seasons, and these data can potentially help improve the melioidosis prevention efforts in Southeast Asia.

3온스 물 삼킴검사 이후 정상 노년층의 음질 변화: 음향학적 분석*

The elderly are at increased risk of developing dysphagia due to aging and illnesses. The aim of the current study was to analyze, via an acoustic study, the change in the voice quality of normal elderly people after a 3oz water-swallow test. Subjects included a group of 60 normal elderly people (age: mean±SD=76.9±6.66) and 60 healthy young adults (age: mean±SD=25.1±2.36). Every participant produced a five-second /a/ phonation pre- and post-swallowing, and the fractioned two-second sections were analyzed using the MDVP (multi dimensional voice program) analysis. The elderly group demonstrated a post-swallowing increase in the following related acoustic parameters: fundamental frequency, fundamental frequency variation, amplitude-variation, and noise in both two-second sections. However, the younger group showed an increase only in frequency related acoustic parameters (i.e., STD ) in the first two-second section. The significant changes in values in the post-swallowing parameters might indicate temporary irregularities in pitch and amplitude along with higher amounts of noise in the voice. The results could be attributed to water residues in the vocal fold and vocal tract, as well as a deterioration of the motor and sensory functions caused by anatomical and physiological changes that result from aging.

Vocalizations, tadpole, and natural history of Crossodactylus werneri Pimenta, Cruz Caramaschi, 2014 (Anura: Hylodidae), with comments on distribution and intraspecific variation.

Crossodactylus werneri was described based on specimens collected in the 1970's at Parque Nacional do Itatiaia, being also reported for nearby localities. We collected specimens that we assigned to C. werneri, and recorded calls of the species during fieldworks at Serra das Cabras (Campinas, state of São Paulo). In this paper, we describe for the first time the vocalizations, tadpole, coloration in life, and comment on aspects of the natural history of C. werneri. Besides, the examination of specimens in zoological collections allowed us to extend the geographic range for this species. We also make remarks on morphological/chromatic variation and provide 16S rDNA sequences for the species. Adults were found along a slow-flowing streamlet with sandy/muddy bottom within a small fragment of secondary forest. Males called between sunset and first hours of the night. Advertisement call consisted of series of pulsed notes. Call duration lasted around 3 s, emitted at the highest rate of 17 calls per minute and six notes per second. Note duration lasted around 18 ms. Notes had poorly defined pulses (irregular and/or weak amplitude modulations along the note). The dominant frequency was about 3380 Hz. Territorial call had a long, well-defined pulsed portion followed by a higher-amplitude "squeak". The dominant frequency was around 3400 Hz. Tadpoles were essentially similar to those of other Crossodactylus species, except by not having nostril ornamentation. Our record of C. werneri in Serra das Cabras might be regarded a rediscovery of this species since C. werneri had not been recorded for more than 30 years until our first record of C. werneri in the field from 2011 and subsequent years. Our record is approximately 100 km west, and Mococa 200 km northwest, from Santo Antônio do Pinhal, the westernmost previous record for C. werneri up to date. Gene sequences (16S rRNA) give insights into the genetic divergence between C. werneri and some congeners.

Active Phase Control for Maximum Power Point Tracking of a Linear Wave Generator

A novel maximum power point tracking (MPPT) method for a wave energy converter is proposed. The output power can be expressed as a product of excitation force and wave speed. Therefore, the condition for maximum extraction of wave energy is ensuring that excitation force is in phase with the velocity of the buoy. However, the phase between excitation force and velocity is determined by the wave period. In the ocean, a wave has an irregular period and amplitude of wave position. In this paper, the wave period was estimated using the velocity and acceleration information. Based on the estimated wave period, the novel MPPT algorithm is proposed. The benefit of the proposed method is that the additional configuration is not required. The proposed MPPT algorithm is presented in detail, in addition to simulation and laboratory test results.

Water migration in poplar wood during microwave drying studied by time domain nuclear magnetic resonance (TD-NMR)

AbstractThe migration of bound water and free water has been investigated during microwave drying of wood by the time domain nuclear magnetic resonance (TD-NMR) technique. Both the heartwood (hW) and sapwood (sW) of Beijing poplar (Populus beijingensisW. Y. Hsu) and Qingpi poplar (Populus platyphyllaT. Y. Sun) were studied. The microwave drying is characterized by a fast drying rate, and there is a linear relation between moisture content (MC) and microwave drying time (t). The drying rate of free water is about 2.7 times more rapid than that of bound water. The spin-spin relaxation time (T2) revealed that most of the water was free water situated in smaller pores. The irregular T2 signal amplitudes of free water in hWs indicated that fractional water in smaller pores was transferred into bigger pores during drying.

DEM study to determine the relationship between particle velocity fluctuations and contact force disappearance

Particle pulsation, which includes velocity and force fluctuations, has already widely existed during the discharge from a silo or hopper. To clarify the characteristics of particle pulsation, in this work, discharge from a 3D conical silo was simulated using the platform with the discrete element method (DEM). The velocity and total force fluctuations were quantitatively analyzed during the initial duration of the discharge and the relationship between velocity fluctuation and contact force disappearance was investigated. Furthermore, the effects of hopper half angle and static friction coefficient (between particle and wall) on velocity fluctuation and contact force disappearance were discussed. The results indicate that both the velocity and total force fluctuations can be divided into three stages and there is a one-to-one corresponding relationship in the violent fluctuation stage. The crest time of velocity fluctuation is the same as the time of contact force disappearance (i.e., particle motion is freely falling body) which only occurs in the violent fluctuation stage. Compared to the larger hopper half angle, the velocity fluctuation exhibits a larger amplitude and higher frequency and the contact force disappearance frequently occurs at the smaller hopper half angle. The velocity fluctuation presents an irregular small amplitude, with no occurrences of contact force disappearance below the critical value of the static friction coefficient, while the velocity fluctuation shows a regular large amplitude, with occurrences of contact force disappearance beyond the critical value. The results are useful for understanding the dynamic behavior of a rice particle during discharge from the conical silo.

Hemi Dystonic Tremor Secondary to Large Intraventricular Tumour in 14-Year-Old Ethiopian Patient: Case Report

Dystonic tremor is defined as tremor in a body part affected by dystonia, this involves: tremor in an extremity or body part that is affected by dystonia, focal tremors, usually with irregular amplitudes and variable frequency (mainly less than 7 Hz), and mainly postural or kinetic tremors, usually not seen during complete rest. Hemi body movement disorder are often considered to be non-primary movement disorder and usually attributed to secondary causes, including environmental, vascular, neoplastic, and infectious. We report 14-year-old male patient presented with progressive left hemi body dystonic tremor which started from left upper limb and progress to left lower limb over a period of three years. He had associated global type of headache which worsens during morning period. No family history of same illness, normal prenatal history, no birth trauma. Physical examination revealed dystonia of left upper limb and lower limb (upper limb>lower limb) mixed with rhythmic tremulous movement of mainly left upper limb. Fundus examination revealed pappiledema bilaterally. Normal liver function test, normal abdominal ultrasound and negative HIV serology. No MRI was performed due to financial reason, but brain CT-scan showed calcified; mildly contrast enhanced Intraventricular mass extending from foramen magnum to lateral ventricle, displacing the septum pallidum to right side and bilaterally dilated lateral ventricle, with possible pressure effect on right basal ganglia. Following brain imaging diagnosis of left hemi dystonic tremor secondary to Intraventricular mass was made and patient was started on low dose clonazepam for symptomatic relief and given appointment for neurosurgical evaluation. Even though secondary/symptomatic causes of movement disorder is uncommon, it’s important to think of secondary causes in patient whom present with hemi body movement disorder, like our patient, as some of the underlying causes could be easily treatable and the symptoms could be relieved if managed early.