Movement Conditions Research Articles

A strategy of vehicle following on slope road at night considering the safety of the intended functionality

As hardware devices that help intelligent vehicles perceive the traffic environment, sensors play a crucial role in vehicle safety control. However, in the face of a complex traffic scene, detection failure is a safety of the intended functionality (SOTIF) problems that may occur due to sensors’ limited functions. For example, under slope road at night, the radar sensor may lose the target because of the narrow detection perspective, vision sensors is prone to severe distortion because of poor light. Therefore, this paper proposes a following strategy to address the SOTIF problems like this. By analyzing the historical data, the motion behavior of the preceding vehicle when SOTIF events happen is predicted based on the improved Markov model. Then, the observation and expectation models of the vehicular distance are designed based on vehicle movement and slope conditions to obtain the distance information. The sliding mode controller is designed to control velocity and prevent collisions and other accidents reasonably. Finally, simulation and hardware-in-the-loop (HiL) tests verify that the proposed method can improve vehicle safety when the sensors’ function fails on slope road at night.

Estimating and minimizing movement artifacts in surface electromyogram

While recording surface electromyography [sEMG], it is possible to record the electrical activities coming from the muscles and transients in the half-cell potential at the electrode-electrolyte interface due to micromovements of the electrode-skin interface. Separating the two sources of electrical activity usually fails due to the overlapping frequency characteristics of the signals. This paper aims to develop a method that detects movement artifacts and suggests a minimization technique. Towards that aim, we first estimated the frequency characteristics of movement artifacts under various static and dynamic experimental conditions. We found that the extent of the movement artifact depended on the nature of the movement and varied from person to person. Our study's highest movement artifact frequency for the stand position was 10Hz, tiptoe 22, walk 32, run 23, jump from box 41, and jump up and down 40Hz. Secondly, using a 40Hz highpass filter, we cut out most of the frequencies belonging to the movement artifacts. Finally, we checked whether the latencies and amplitudes of reflex and direct muscle responses were still observed in the highpass-filtered sEMG. We showed that the 40Hz highpass filter did not significantly alter reflex and direct muscle variables. Therefore, we recommend that researchers who use sEMG under similar conditions employ the recommended level of highpass filtering to reduce movement artifacts from their records. However, suppose different movement conditions are used. In that case, it is best to estimate the frequency characteristics of the movement artifact before applying any highpass filtering to minimize movement artifacts and their harmonics from sEMG.

The Stone Age Sannikov Land: human dimensions

The New Siberian Islands are one of the most remote and hardly accessible regions of the Russian Arctic. Due to that, their discovery and initial study took about 300 years. For dozens of thousand years during the Late Pleistocene, this area was a part of drained arctic shelf, a part of which still existed around 9000 years ago. In certain sense, it was the Sannikov Land of the Stone Age. In 1914, the Zhokhov Island became the last one to be discovered out of large islands of the archipelago. Fifty years afterwards, archaeological material was found on it. The Zhokhov site, studied in 1989–1990 and 2000–2005, is one of the northernmost archaeological sites in the world. Human activity at the Zhokhov site falls within the interval 8300–7750 14C years ago, with the most intense occupation spanning 8050–7900 14C BP, that is, roughly CA 9000 calendar years ago. Excavations yielded a unique collection that includes lithic material presenting microprismatic technology, polished stone tools, a variety of artefacts made of non-durable materials (diverse osseous material and wood), including hunting equipment, home utensils, basketry and birch bark products, as well as sled parts. Excavations yielded a large number of animal bone remains, almost exclusively belonging to the reindeer and polar bear. It is shown that in the reconstructed annual economic cycle of the Zhokhov dwellers in winter, the most important role was played by polar bear hunting. Mass procurement of this dangerous animal for food is a unique hunting specialization, while mass accumulation of his bone remains can not be taken as an evidence for the bear cult. It is shown, that the Zhokhov hunters widely used dog sleds and thus the land transportation system was the most important innovation of the Pleistocene-Holocene boundary. The Zhokhov site environments of 9000 years ago were quite comfortable for the Arctic regions. Open landscapes were the most important feature of their habitat providing unlimited opportunities for traveling across the region, especially in winter and spring and thus provided conditions for effective movement of people goods, and genes including long-distance transport.

Explanation of the mechanisms of unsteady gas flow through the turbocharger seal system, including thermal and structural interactions

Gas flow in the seal system can be expected during the operation of a turbocharger and is associated with negative effects on the quality of the lubricant or turbocharger efficiency. Gas flow also affects particulate matter production due to lubricant entrainment in the compressor or turbine. The prediction of gas flow rates depends on many design parameters and the operating conditions of the turbocharger, but sufficiently accurate descriptions of the gas flow mechanisms and their quantification depending on the operating conditions have not yet been presented. The proposed computational approach simultaneously solves the gas dynamics in the seal system, the heat transfer in the turbocharger rotor-bearing system and the dynamics of the seal rings and rotor, including the bearings. The computational model for the turbocharger of a heavy-duty vehicle engine is experimentally validated. Two mechanisms have major influences on gas mass flow: the gas flow through the thin gap between the moving ring and groove and the flow through the ring gap. The results show that the importance of these mechanisms depends on several geometrical dimensions of the seal system and the operating conditions of the turbocharger, with a strong connection to the rotor dynamics and thermal load of the impellers. Influences involving rotor movement or rotor thermal conditions are crucial, and their non-inclusion limits the ability to correctly predict gas mass flow.

Differential contribution of between and within-brain coupling to movement synchronization.

A fundamental characteristic of the human brain that supports behavior is its capacity to create connections between brain regions. A promising approach holds that during social behavior, brain regions not only create connections with other brain regions within a brain, but also coordinate their activity with other brain regions of an interaction partner. Here we ask whether between-brain and within-brain coupling contribute differentially to movement synchronization. We focused on coupling between the inferior frontal gyrus (IFG), a brain region associated with the observation-execution system, and the dorsomedial prefrontal cortex (dmPFC), a region associated with error-monitoring and prediction. Participants, randomly divided into dyads, were simultaneously scanned with functional near infra-red spectroscopy (fNIRS) while performing an open-ended 3D hand movement task consisting of three conditions: back-to-back movement, free movement, or intentional synchronization. Results show that behavioral synchrony was higher in the intentional synchrony compared with the back-to-back and free movement conditions. Between-brain coupling in the IFG and dmPFC was evident in the free movement and intentional synchrony conditions but not in the back-to-back condition. Importantly, between-brain coupling was found to positively predict intentional synchrony, while within-brain coupling was found to predict synchronization during free movement. These results indicate that during intentional synchronization, brain organization changes such that between-brain networks, but not within-brain connections, contribute to successful communication, pointing to shift from a within-brain feedback loop to a two-brains feedback loop.

Modelling 3D dynamics of offshore lattice jib cranes by means of the rigid finite element method

Offshore cranes require particularly careful design due to the difficult environmental conditions in which they work. This paper presents a 3D model of the dynamics of an offshore crane with a truss jib formulated by means of the rigid finite element method. The inertial features of the truss members are assigned to nodes whose rotational and translational displacements are degrees of freedom. Flexible features of the truss members are modelled by massless and dimensionless spring–damping elements (sde). The computer programme developed on the basis of the model is verified and validated, and good correspondence of the authors’ own results with those obtained using commercial FEM package is achieved. Computer simulations are carried out for the light crane used on the wind platforms. The influence of the base movements (sea waves) on the system are also investigated. Lifting a load from a supply vessel and the load on the system during rotational movement of the crane are simulated too. Finally, conclusions concerning the influence of the movement conditions on the overload coefficient and deflections of the crane boom are formulated.

Visuo-motor interference is modulated by task interactivity: A kinematic study

Extensive evidence shows that action observation can influence action execution, a phenomenon often referred to as visuo-motor interference. Little is known about whether this effect can be modulated by the type of interaction agents are involved in, as different studies show conflicting results. In the present study, we aimed at shedding light on this question by recording and analyzing the kinematic unfolding of reach-to-grasp movements performed in interactive and noninteractive settings. Using a machine learning approach, we investigated whether the extent of visuo-motor interference would be enhanced or reduced in two different joint action settings compared with a noninteractive one. Our results reveal that the detrimental effect of visuo-motor interference is reduced when the action performed by the partner is relevant to achieve a common goal, regardless of whether this goal requires to produce a concrete sensory outcome in the environment (joint outcome condition) or only a joint movement configuration (joint movement condition). These findings support the idea that during joint actions we form dyadic motor plans, in which both our own and our partner’s actions are represented in predictive terms and in light of the common goal to be achieved. The formation of a dyadic motor plan might allow agents to shift from the automatic simulation of an observed action to the active prediction of the consequences of a partner’s action. Overall, our results demonstrate the unavoidable impact of others’ action on our motor behavior in social contexts, and how strongly this effect can be modulated by task interactivity.

Effects of arm movement strategies on emotional state and balance control during height-induced postural threat in young adults

BackgroundIt is firmly established that postural threat seems to lead to an increased reliance on an ankle control (‘stiffening’) strategy. However, little is known about how postural threat affects performance in challenging tasks that require the use of upper body postural control strategies for stability. It is logical to assume that in such conditions, being able to utilise an upper body strategy may reduce the reliance on such ankle stiffening strategy. Research questionThe objective of this study was to determine how arm movement influences balance control during a challenging balance task performed under conditions of postural threat. MethodsThirty young adults (mean ± SD age; 22.0 ± 4.0 years) balanced in tandem stance whilst standing at both ground-level (no threat) and 0.8 m above ground (threat). In both conditions, participants performed the task under two different arm positions: restricted arm movements and free arm movements. Postural sway amplitude and frequency were calculated to infer postural stiffening response. Self-reported emotional responses were quantified by assessing balance confidence, fear of falling, perceived stability, and conscious balance processing. ResultsIndependent of arm movements, postural threat evoked an increase in fear of falling and conscious balance processing, and reductions in balance confidence and perceived stability. These threat-related changes in emotional state were further amplified when arm movements were restricted. Whilst significant increases in sway frequency during threat were observed in both arm conditions, reductions in sway amplitude were only observed during the restricted arm movement condition. SignificanceWe propose that these responses likely reflect a fear-related cautious strategy intended to reduce the postural destabilisation associated with individuals being unable to use their arms to counter any destabilisation, as would normally be the case in daily life.

An Outlook of Amavata W.S.R to Rheumatoid Arthritis

With modernisation dietary habits, life style, social structure and environment have been changing. Due to lack of physical activity and sedentary life style, metabolism of body is getting slower. In Ayurveda this is called dysfunction of Agni (Jatharagni and Dhatwagni). Impaired status of Agni leads to formation of Ama. Deposition of Ama hampers the functions of Vata leading to condition called Amavata. Occurrence of Amavata on large scale is one of the outcomes of this modernisation. Amavata is progressive sporadic disorder found in general population with complaints of difficulty in doing routine work due to dysfunction of joints especially due to pain, stiffness and swelling. Clinical presentation of Amavata closely resembles with Rheumatoid arthritis (RA). It is an autoimmune chronic inflammatory disease characterized by inflammation of synovial joints leading to destruction of joint and periarticular tissue. Patients are almost functionless for their work due to sluggish movement and painful condition. Amavata is one of the most troubles causing disorder for patients due to its deformity causing nature. It is also very challenging for clinicians due to its chronicity, incurability, and complications. Lack of awareness in the society about disease people suffer lifelong joint deformity. Contemporary system of medicine offers only symptomatic and palliative treatment which has more complications than benefits to the patients.

Electromyographic signals and the starting threshold voltage of orbicularis oris muscle in healthy rhesus monkeys

Objective: To investigate the characteristics of electromyography (EMG) signals and the starting threshold voltages of the orbicularis oris muscles (OOM) in healthy rhesus monkeys under different muscle movement conditions. Methods: The EMG signals and the starting threshold voltages at different time points in 4 healthy rhesus monkeys were acquired and recorded with EMG device and evoked potentiometer. The voltage amplitude variation of EMG signals was analyzed, and the voltage amplitude range of EMG signals at the beginning of OOM contraction was established. The data were statistically analyzed by one-way ANOVA. Results: The EMG of OOM in healthy monkeys in the quiet, natural and continuous mouth-closed state was linear and relatively stable, and the absolute value fluctuated between 15 and 50 μV. The EMG waveform increased rapidly during the natural lip contraction movement, and its amplitude fluctuated greatly, with the highest absolute value of the peak value reaching hundreds of microvolts. The amplitude of EMG induced by continuous mouth closure was more than thousands of microvolts. There was no significant difference in EMG amplitudes of OOM in the healthy rhesus monkey under quiet and continuous lip closure at different time points (P>0.05). There was no significant difference in threshold voltages in the state of natural lip contraction of bilateral OOM at different time points (average range: 57.17-57.47 μV) in the healthy rhesus monkeys (P>0.05). There was no significant difference in threshold voltages of OOM induced by bilateral OOM at different time points(average range: 55.38-55.99 μV) in the healthy rhesus monkeys(P>0.05). There were significant differences in the absolute values of EMG amplitudes of OOM between the three lip movement modes: (30.67±8.72) μV in quiet and natural continuous lip closure (475.12±54.72) μV in natural lip contraction, and (921.22±312.79) μV in the induced persistent lip closure, with t values of -8.48, -9.35 and -5.01 respectively, all P<0.001. Conclusions: The EMG signals of OOM show different characteristics under different muscle movement conditions, which can be used as a basis for computer to judge and recognize the movement conditions of OOM. The upper limits of the EMG threshold voltage values of OOM under different motion states are 55-60 μV.

Geographical space and cinema images of the white Arctic on a white screen (Part I)

The infinity of spaces, open spaces, the “White Silence” of the classical Arctic with a harsh climate, with its ice-bound Arctic Ocean, polar seas, archipelagos, islands covered with glaciers and snow, rocks breaking off into the sea, permafrost has always been a hostile environment, causing human fear. The icy Arctic desert on the shores turns into hard-to-reach areas of tundra, forest tundra and northern taiga. These are Siberia, Alaska, the Canadian Arctic archipelago, the Scandinavian-Icelandic polar regions. But it was their ignorance, their natural riches of furs, fish, forest, gold, and later oil and gas that attracted attention. With the advent of cinema, the Arctic and the North Pole crowning it, actually frozen ocean water, became the object of cinematographers. The whiteness of snow and ice refers us to the white sheet screen. The “white” polar nature appeared on it, affecting the destinies of people living in it, and those who came to master and transform it. The creators of cinema groped their way as well as the conquerors of the North Pole. At the beginning of the twentieth century . world directors Georges Milies, Bester Keaton, Lev Kuleshov, Charlie Chaplin have trodden the fantastic-comedy and dramatic silent cinematic Arctic path with their films. Then there were expedition documentaries, because the operators in the composition of the expeditions had to capture the historical events taking place in truly Arctic conditions, and a little later, feature films sometimes with world movie stars, in which, in accordance with the natural conditions of movement, new performers were introduced — animals, in particular dogs, deer, bears. The image, sound, and movement helped to enhance the demonstration of the color of Arctic landscapes and subjects on a white screen. Gradually, the Arctic occupied its niche in the panorama of world cinema not only as a decoration, but also as a full-fledged socio-geographical “actor”. However, the geography of film production of Arctic films is quite limited, although more than a hundred have been shot, which is explained by the few countries that surround the Arctic Ocean. The Arctic belongs to five states forming the Arctic Council — Russia, USA, Canada, Denmark, Norway. The article examines the history, genres, plot-thematic aspects of Arctic feature films.

Using Speed and Accuracy and the Simon Effect to Explore the Output Form of Inhibition of Return

Inhibition of return (IOR) refers to slower responses to targets presented at previously cued locations. Contrasting target discrimination performance over various eye movement conditions has shown the level of activation of the reflexive oculomotor system determines the nature of the effect. Notably, an inhibitory effect of a cue nearer to the input end of the processing continuum is observed when the reflexive oculomotor system is actively suppressed, and an inhibitory effect nearer the output end of the processing continuum is observed when the reflexive oculomotor system is actively engaged. Furthermore, these two forms of IOR interact differently with the Simon effect. Drift diffusion modeling has suggested that two parameters can theoretically account for the speed-accuracy tradeoff rendered by the output-based form of IOR: increased threshold and decreased trial noise. In Experiment 1, we demonstrate that the threshold parameter best accounts for the output-based form of IOR by measuring it with intermixed discrimination and localization targets. Experiment 2 employed the response-signal methodology and showed that the output-based form has no effect on the accrual of information about the target's identity. These results converge with the response bias account for the output form of IOR.

An Overview of Clinical Conditions and a Systematic Review of Personalized TMJ Replacement.

The temporomandibular joint (TMJ) is a complex structure in the cranio-maxillomandibular region. The pathological changes of the joint cause deficiencies at different levels, making its replacement necessary in some cases. The aim of this article is to analyze the current indications, treatment and criteria, and follow-up using a systematic review and case series. A systematic review was carried out, identifying the indications for the use of a customized TMJ prosthesis and evaluating criteria and validation in the international literature. After review and exclusion, 8 articles were included with a minimum follow-up of 12 months. The age of the subjects was between 18 and 47 years old. In 226 patients, 310 TMJ prostheses were installed, 168 bilaterally and 142 unilaterally. In most of the articles, a good condition in the follow-up was observed, with a reduction in pain and better conditions of mandibular movement and function. TMJ prosthesis and replacement is a protocolized, defined, stable, and predictable procedure. Indications and criteria must be evaluated by specialists and patients related to the pathology involved in TMJ deformity or degeneration. Randomized research with an accurate diagnosis and follow-up is necessary to obtain the best indication for this treatment.

Binocular see-through configuration and eye movement attenuate visual rivalry in peripheral wearable displays.

Visual confusion occurs when two dissimilar images are superimposed onto the same retinal location. In the context of wearable displays, it can be used to provide multiple sources of information to users on top of the real-world scene. While useful, visual confusion may cause visual rivalry that can suppress one of the sources. If two different images are projected to each eye (i.e., monocular displays), it provokes binocular rivalry wherein visual perception intermittently switches between the two images. When a semi-transparent image is superimposed (i.e., see-through displays), monocular rivalry results, causing perceptual alternations between the foreground and the background images. Here, we investigated how these rivalries influence the visibility of the peripheral target using three configurations of wearable displays (i.e., monocular opaque, monocular see-through, and binocular see-through) with three eye movement conditions (i.e., saccades, smooth pursuit, and central fixation). Using the HTC VIVE Eye Pro headset, subjects viewed a forward vection of a 3D corridor with a horizontally moving vertical grating at 10° above the center fixation. During each trial (~1 min), subjects followed a fixation cross that varied in location to induce eye movements and simultaneously reported whether the peripheral target was visible. Results showed that the binocular display had significantly higher target visibility than both monocular displays, and the monocular see-through display had the lowest target visibility. Target visibility was also higher when eye movements were executed, suggesting that the effects of rivalry are attenuated by eye movements and binocular see-through displays.

Evaluation of motion artifacts reduction software that compensate for respiratory movements in the craniocaudal direction during abdominal cone-beam computed tomography

We acquired cone-beam computed tomography (CBCT) images of a locally made contrast-enhanced hepatic artery phantom under various conditions, both with the phantom still, and while moving it from the cranial to the caudal position. All the motion CBCT images were processed with and without motion artifacts reduction software (MARS). We calculated some quantitative similarity indexes between the still CBCT images (no-motion) and the motion CBCT images both processed with MARS (MARS ON) and without MARS (MARS OFF). In addition, the vessel signal values under the same movement conditions of the MARS ON/OFF and no-motion were evaluated. All quantitative similarity indexes between MARS ON and no-motion were significantly higher than between MARS OFF and no-motion in all movement conditions (p < 0.01). The vessel signal values were higher in MARS ON than in MARS OFF (p < 0.01) and closer to no-motion in all movement conditions.

Teaching speaking as a type of speech activity of students with poor command of the state language of the Russian Federation

Introduction. Under current socio-economic, political conditions of large-scale and dynamic movement of various cultural, ethnic and linguistic groups given that special responsibility rests with the school while forming a creatively active, spiritual and moral personality, the presence in the classes of students with poor command of the Russian language does not contribute to the effective functioning of educational process. Students unable to express their socio-cultural, cognitive needs and/or make contact with the teacher and classmates, avoid verbal interaction, lose interest in the Russian language and, as a result, in the entire educational process. The purpose of the study is to develop methodological recommendations, a system of language and communicative exercises for teaching speaking to students with poor command of the state language of the Russian Federation, based on the analysis of the mistakes they make. Materials and Methods. The study involved 12 teachers and 70 students in grades 3-4 of several schools in the Laksky district of the Republic of Dagestan of the Russian Federation (Iberian-Caucasian group), students of multi-ethnic classes of the experimental school in the Moscow region, where children who are native speakers of Western Iranian (Tajikistan), Turkic ( Kyrgyzstan, Uzbekistan) language groups study. The following methods were used: questioning of teachers; analysis of the received data; analysis of mistakes made by students who have poor command of the state language of the Russian Federation (based on the material of teachers' questionnaires). Results. The analysis of typical mistakes made by students who are native speakers of languages of various language groups (Turkic, Western Iranian, Iberian-Caucasian), who have little command of the state language of the Russian Federation, suggests that when generating monologue and dialogic speech, students make the following mistakes: pronunciation mistakes (the majority of students), grammar mistakes (smaller number of students), lexical mistakes (fewer students). When generating a monologue statement, the main mistakes include: violation of the logic of presentation, the structure of the text; fuzzy formulation of thoughts and their argumentation. In a dialogical speech the main mistakes of students are the incorrect use of interrogative words and the lack of a quick reaction to the interlocutor's remark, and sometimes an inadequate response to it. Conclusion. This study is based on the analysis of the mistakes made by students with poor command of the state language of the Russian Federation. The practical significance of the study is due to the possibility of using methodological recommendations, a system of language and communicative exercises in teaching students prepared and unprepared monologue and dialogic speech.

Analysis of middle-to-far wake behind floating offshore wind turbines in the presence of multiple platform motions

Understanding the unsteady characteristics of the mid-to-far wake and comprehension of the aerodynamic performance of floating offshore wind turbines is essential for the further development of offshore wind farms. In this perspective, a developed Actuator line model is utilized to analyze an offshore turbine on four different platforms. The model reliability was examined through three sets of validations involving turbine output in fixed and floating conditions and wake expansion in terms of size and rate. The affected relative velocity by the platform motion contributes to the wake deformation and temporal effects on induced velocity. Angular platform motions produce a non-axisymmetric helical wake that raises the chance of meandering wake patterns. It was founded although platform movement generally can boost the recovery of mean velocity value, it may amplify the amplitude of velocity deficit fluctuation at further downstream by encouraging interactions and merging vortex rings. Consequently, the wake propagates into a form of stronger circles whose period, strength, and center are functions of turbine movement and operation conditions. By providing a computationally efficient tool, the findings emphasize the importance of wake propagation in designing and assessing farm layouts that operate in the presence of significant multi-motions of floating offshore wind turbines.

Characteristics of the Contingent Negative Variation during Lower Limb Functional Movement with an Audio-Visual Cue

Background: The contingent negative variation (CNV) is a negative shift in electroencephalography (EEG) related to the planning and execution of an externally cued movement task. The CNV has the potential to be applied within stroke rehabilitation; however, there is insufficient knowledge about the CNV characteristics under movement conditions relevant to rehabilitation. This study explores the CNV characteristics during a functional movement task (versus a simple movement task) and when using an audio-visual cue that has been previously evaluated for its usability in stroke rehabilitation (versus a simple visual cue). Methods: Thirty healthy participants performed five randomized movement tasks: simple ankle dorsiflexion with a visual cue (1), audio-visual cue (2), and auditory-only cue (3), and sit-to-stand with a visual (4) and audio-visual cue (5). Fifty repetitions of each movement were performed while continuous EEG was recorded. The band-passed and Laplacian-filtered (Cz) EEG was averaged for each condition and the peak negativity (PN) latency and amplitude were identified. Results: PN latency was significantly later during sit-to-stand with the audio-visual cue versus the visual cue (p = 0.027). PN amplitude was significantly larger during sit-to-stand versus ankle dorsiflexion, with both visual and audio-visual cues (p &lt; 0.0001). Conclusion: The CNV changes under more complex movement conditions. Assumptions about the MRCP from simple laboratory recordings should not be generalized to the rehabilitation setting.

A Model-Based Approach for Setting the Initial Angle of the Drive Axles in a 4 × 4 High Mobility Wheeled Vehicle

This article presents an analysis of the driveline operation of a high-mobility Jelcz 442.32 wheeled vehicle, which uses rigid drive axles connected to drive shafts with two universal joints (another name for the Cardan joints) due to the occurrence of kinematic incompatibility. The conditions for the correct connection of the drive shafts with two universal joints (Cardan joints) were presented, and the kinematic ratio of the complete drive shaft was defined. In the analysis of kinematic incompatibility regarding (but not limited to) the method of loading the vehicle, selected characteristic conditions of vehicle movement and the initial values of the angular setting of the rigid driving axles in relation to the vehicle body were presented. It has been shown that, in the analyzed vehicle, the kinematic incompatibility in the driveline is constantly present, and the value of this incompatibility, represented by the temporary ratio of drive shafts, depends on, among other things, the ways of loading the vehicle, the existing conditions of vehicle movement, and the type of ground. Moreover, the value of the arising kinematic incompatibility was noticed to be highly influenced by the correct manufacturing and assembly of the vehicle springs.

On “ethnic migrants” and the beginning of their ethnographic study in Central Europe

“Ethnic migrants” can be understood as participants of a specific type of migration, which is characterized by institutional and material facilitation by the host country of the conditions of migration movement based solely on the ethnic origin of migrants. The ethnic origin declared by such migrants, as a rule, coincides with the ethnic origin of the titular nation located in the target country. The aim of this article is to depict the mode of implementation and methodological preconditions of one of the first attempts at ethnographic analysis of so-called ethnic migrants and to convey how the thematic and methodological directions of the aforementioned scientific approach led to theoretical innovations in German-speaking ethnology in the post-war period. As an example, studies of disappearing ethnographic phenomena conducted among Bessarabian migrants of German origin in the territory of the then Protectorate of Bohemia and Moravia will be presented.