Movement In Direction Research Articles

Procedure of determination of the cold compressive strength of samples of refractory inserts for composite plates of shuttles

The slide gate is the most advanced type of casting device. The design of this gate is based on the action of two refractory plates, which are in close contact with each other, one of which slides on the other, fixed motionlessly. Sliding gates can be of two types: with a lower movable plate, which carries out a back-and-forth movement in the horizontal direction using a hydraulic cylinder, and with a lower movable plate, which rotates around an axis. The shutter of first type is called a slide gate; the second is a rotary shutter.
 Monitoring of properties in particular strength of refractory inserts facilitates increase in operation reliability of constituent plates of sliding shutters in steel casting ladles. However, it is not possible to apply the existing standards for the compressive strength determination of these refractory products, because these standards do not provide for test samples with dimensions less than 20 mm. That's why the procedure MB 322-39-2021 was developed and implemented by JSC “URIR named after A. S. Berezhnoy” with the purpose of monitoring of cold compressive strength of refractory inserts for constituent plates of sliding shutters. According to this procedure, a method for measuring the compressive strength is used: the cross-sectional area of the test sample is determined, the maximum compressive load that leads to the test sample failure is measured, and the compressive strength is calculated.

Retrospective Robot-Measured Upper Limb Kinematic Data From Stroke Patients Are Novel Biomarkers.

Background: The efficacy of upper-limb Robot-assisted Therapy (ulRT) in stroke subjects is well-established. The robot-measured kinematic data can assess the biomechanical changes induced by ulRT and the progress of patient over time. However, literature on the analysis of pre-treatment kinematic parameters as predictive biomarkers of upper limb recovery is limited.Objective: The aim of this study was to calculate pre-treatment kinematic parameters from point-to-point reaching movements in different directions and to identify biomarkers of upper-limb motor recovery in subacute stroke subjects after ulRT.Methods: An observational retrospective study was conducted on 66 subacute stroke subjects who underwent ulRT with an end-effector robot. Kinematic parameters were calculated from the robot-measured trajectories during movements in different directions. A Generalized Linear Model (GLM) was applied considering the post-treatment Upper Limb Motricity Index and the kinematic parameters (from demanding directions of movement) as dependent variables, and the pre-treatment kinematic parameters as independent variables.Results: A subset of kinematic parameters significantly predicted the motor impairment after ulRT: the accuracy in adduction and internal rotation movements of the shoulder was the major predictor of post-treatment Upper Limb Motricity Index. The post-treatment kinematic parameters of the most demanding directions of movement significantly depended on the ability to execute elbow flexion-extension and abduction and external rotation movements of the shoulder at baseline.Conclusions: The multidirectional analysis of robot-measured kinematic data predicts motor recovery in subacute stroke survivors and paves the way in identifying subjects who may benefit more from ulRT.

ZERO WASTE LIFESTYLE CONCEPT WITHIN ISLAMIC-SCIENCE PRESPECTIVE

Islam has comprehensive rule that regulate in all aspects of human life, including evireonmental issues. One fact of global problems related to environment is waste management problem. Zero waste is waste management system which it could be a holistic solution due to waste issue. This study aim to analyse the zero waste concept within Islamic-science prespective on municipal waste reduction as a solution to prevent environmental damage. This study use literature reviews method that focuse on waste management programs in Surabaya City which have been stated on a national and international scale. The results of this study show implementation of waste management programs In Surabaya City such as the depletion of disposable plastic usage, the existence of waste bank units, until the presence of a solid waste power plant infrastructure. However, the program implementation has not been able to decrease the number of resource in Surabaya landfill. It is because of poorly coordination between government and society, and the lack of environmental awareness about the harm of waste resource to environmental health. Thus, the existence of zero waste concept combined with Islamic-science prespective could lead direction movement to appreciate the importance of proper and correct waste management. Based on these results, it conclude that waste management with zero waste concept considered to become a new lifestyle in waste management namely Islamic lifestyle, because it is in line with Islamic law. Moreover, this new lifestyle could be implemented in all communities regarding to the nature is a gift form Allah SWT and humans have a command to protect it.

Study of dynamic characteristics of flow in plane-parallel and taper clearances of drives of electric power systems

The hydrodynamic parameters of the flow of a viscous working fluid in plane-parallel and conical gaps in drives of electric power systems are investigated. A general expression is found for determining the regularity of the change in the flow rate in the gaps of non-contact seals, and special cases are considered. In the case of frictional movement of one of the walls, the Couette flow is observed in the gap. When the pressure is applied to the liquid in the gap, a parabolic velocity distribution is observed with a maximum in the middle of the channel. Under the joint action of the frictional movement of the wall and the pressure flow in the channel, stratification of fluid movement in opposite directions is observed. Frictional flow in conical slots, when the fluid moves in only one direction, is possible at a taper value of -0,5...1,0. In all other cases, the flow in the slot will have two opposite flow directions. The presence of two opposite flows inside the slot can also be for the case when the direction of movement of the movable wall coincides with the direction of the pressure flow. This is caused by an increase in pressure within the gap. A general solution has been found for the pressure force in the gaps, which tends to push the walls apart, i.e. open the sealing surfaces. The analysis of the pressure force is carried out for various cases of the slotted gap and under various effects of the frictional flow and pressure head.

"Taking action" to reduce pain-Has interpretation of the motor adaptation to pain been too simplistic?

Movement adapts during acute pain. This is assumed to reduce nociceptive input, but the interpretation may not be straightforward. We investigated whether movement adaptation during pain reflects a purposeful search for a less painful solution. Three groups of participants performed two blocks (Baseline, Experimental) of wrist movements in the radial-ulnar direction. For the Control group (n = 10) both blocks were painfree. In two groups, painful electrical stimulation was applied at the elbow in Experimental conditions when the wrist crossed radial-ulnar neutral. Different stimulus intensities were given for specific wrist angles in a secondary direction (flexion-extension) as the wrist passed radial-ulnar neutral (Pain 5–1 group:painful stimulation at ~5 or ~1/10—n = 21; Pain 5–0 group:~5 or 0(no stimulation)/10—n = 6)). Participants were not informed about the less painful alternative and could use any strategy. We recorded the percentage of movements using the wrist flexion/extension alignment that evoked the lower intensity noxious stimulus, movement variability, and change in wrist/forearm alignment during pain. Participants adapted their strategy of wrist movement during pain provocation and reported less pain over time. Three adaptations of wrist movement were observed; (i) greater use of the wrist alignment with no/less noxious input (Pain 5–1, n = 8/21; Pain 5–0, n = 2/6); (ii) small (n = 9/21; n = 3/6) or (iii) large (n = 4/21; n = 1/6) change of wrist/forearm alignment to a region that was not allocated to provide an actual reduction in noxious stimulus. Pain reduction was achieved with “taking action” to relieve pain and did not depend on reduced noxious stimulus.

Postural Control under Cognitive Load: Evidence of Increased Automaticity Revealed by Center-of-Pressure and Head Kinematics

How postural responses change with sensory perturbations while also performing a cognitive task is still debatable. This study investigated this question via comprehensive assessment of postural sway, head kinematics and their coupling. Twenty-three healthy young adults stood in tandem with eyes open or wearing the HTC Vive Head-Mounted Display (HMD) with a static or dynamic (i.e., movement in the anterior-posterior direction at 5 mm or 32 mm at 0.2 Hz) 3-wall stars display. On half of the trials, participants performed a cognitive serial subtraction task. Medio-lateral center-of-pressure (COP) path significantly increased with the cognitive task, particularly with dynamic visuals whereas medio-lateral variance decreased with the cognitive task. Head path and velocity significantly increased with the cognitive task in both directions while variance decreased. Head-COP cross-correlations ranged between 0.78 and 0.66. These findings, accompanied by frequency analysis, suggest that postural control switched to primarily relying on somatosensory input under challenging cognitive load conditions. Several differences between head and COP suggest that head kinematics contribute an important additional facet of postural control and the relationship between head and COP may depend on task and stance position. The potential of HMDs for clinical assessments of balance needs to be further explored.

Predicting the Direction Movement of Financial Time Series Using Artificial Neural Network and Support Vector Machine

Prediction of financial time series such as stock and stock indexes has remained the main focus of researchers because of its composite nature and instability in almost all of the developing and advanced countries. The main objective of this research work is to predict the direction movement of the daily stock prices index using the artificial neural network (ANN) and support vector machine (SVM). The datasets utilized in this study are the KSE-100 index of the Pakistan stock exchange, Korea composite stock price index (KOSPI), Nikkei 225 index of the Tokyo stock exchange, and Shenzhen stock exchange (SZSE) composite index for the last ten years that is from 2011 to 2020. To build the architect of a single layer ANN and SVM model with linear, radial basis function (RBF), and polynomial kernels, different technical indicators derived from the daily stock trading, such as closing, opening, daily high, and daily low prices and used as input layers. Since both the ANN and SVM models were used as classifiers; therefore, accuracy and F-score were used as performance metrics calculated from the confusion matrix. It can be concluded from the results that ANN performs better than SVM model in terms of accuracy and F-score to predict the direction movement of the KSE-100 index, KOSPI index, Nikkei 225 index, and SZSE composite index daily closing price movement.

Initial data from monitoring of a landslide process affecting Emine Cape, Bulgaria

In October 2019, a 3D extensometer was installed to monitor slow landslide movements, affecting the slope of Cape Emine north of the lighthouse. For almost 2 years of observations, a tendency of shrinkage of the zone as a result of lateral pressure from the southern landslide was established. The movements are divided into two stages: the first – until December 2020, and the second – after that date. In the months from April to June the movements in direction X are more intensive due to the rainy situation at this time of the year.

Axial Shuffling on Pebble Bed Reactor using PRAKTIK 3D-HTR

With moving fuel, the pebble bed reactor (PBR) provides flexibility in the fuel management process due to the capability of online fuel refueling. This capability allows the reactor to operate at any given time without the need to shut down for refueling. The complexity of the depletion and burnup analysis requires the problem to be solved with sophisticated and robust computer codes that can handle the fuel shuffling. Since the fuel refueling is conducted from top to bottom, the shuffling and fuel movement in the axial direction should be modeled with acceptable accuracy. The purpose of the simulation is to obtain the equilibrium or even a critical condition of the reactor. The model used is based on the simplified pebble bed reactor with 200 MWt of thermal reactor power, 3 meters of core diameter, and 10 meters of core height. To model the axial shuffling on the reactor, a neutronic computer code called PRAKTIK 3D-HTR is used. The code utilizes the diffusion method in a three-dimensional cylindrical geometry to model the neutronic phenomena in the reactor. Moreover, PRAKTIK 3D-HTR is equipped with the burnup calculation and depletion analysis to be able to handle fuel movement. Finally, the axial shuffling mechanism is implemented using the once-through-then-out (OTTO) method. Implementing this method to the reactor, an equilibrium condition can be obtained. In this condition, the reactor condition in terms of criticality and flux shape is relatively constant. The critical condition can also be searched using PRAKTIK 3D-HTR to obtain the condition when the multiplication factor is equal to unity. The criticality search is conducted by changing the fuel movement speed. If the multiplication factor is less than 1, then the shuffling speed needs to be increased. Otherwise, if it is more than 1, the shuffling speed will be decreased.

The relationship between vection, cybersickness and head movements elicited by illusory motion in virtual reality

Cybersickness is an unpleasant side effect of Virtual Reality and is often detrimental to a user’s experience. It shows a complex relationship to vection (illusory self-motion) as well as postural instability. Three experiments were conducted presenting both expanding and rotating colourful optimised Fraser Wilcox illusions as well as grey-scaled controlled versions of the illusions. Cybersickness and vection were reported and head movements in medio-lateral and anterior-posterior direction were recorded. The experiments found that perceived visual motion (illusory motion) is sufficient to elicit vection in the absence of any stimulated visual motion. The strength of motion perceived in the illusions was related to the experience of cybersickness and vection, with illusions that were perceived as moving more eliciting stronger experiences of both. Surprisingly, rotating illusions were continuously perceived as moving more compared to expanding motion illusions, which could be related to missing stereoscopic motion-in-depth cues. Head movements were unrelated to any stimuli properties, suggesting that the motion signal elicited by the illusions might not have been strong enough to cause postural instability. Finally, dizziness has been identified as the possible link between cybersickness, vection and head movements supporting sensory conflict as well postural instability theories of cybersickness.

Path planning strategies for hardness improvement employing surface remelting in AISI 1045 steel

The use of remelting as heat treatment for metallic components has grown on an industrial scale, particularly in sectors where surface hardness is a requirement. Using a conventional Tungsten Inert Gas (TIG) welding torch, it is possible to induce desirable microstructures, promote grain refinement, and as a result, increase hardness. However, one of the main challenges concerns understanding the effects of remelting strategies based on the torch/tool path planning. It is possible to draw different conclusions under the same processing parameters depending on the tool's trajectory. Therefore, the present study aims to assess the influence of remelting path strategies on the AISI 1045 steel hardness, correlating its microstructure with thermal variables obtained from an in-house Finite Volume numerical model. Two different approaches are analyzed, namely Strategy 1 and Strategy 2.The former was characterized as a single direction movement with 77 s average time between beads, while Strategy 2 was chosen as double direction movement (zigzag) without interbead time. In both cases, TIG remelting was applied autogenously with 120A Direct Current Electrode Negative (DC-), at 15 cm/min, with a 30% overlap ratio for five parallel beads, and with Argon as shielding gas. The results pointed out that both strategies promoted a hardness increase relative to the base metal, 23% for Strategy 1 and 9% for Strategy 2. This factor was attributed to grain refining. The simulation revealed that Strategy 1 is more suitable than Strategy 2 to boost the hardness is related to the higher solidification cooling rate (166 °C/s versus 137 °C/s, respectively) and lower time above 900 °C (7 s versus 12 s, respectively).

Experimental determining of horizontal movements of the water tower reservoirs by GB-RAR

Ground-based radar interferometry (GBRI) with ground-based real aperture radar (GB-RAR) is most often used for monitoring vertical deflections of bridge structures caused by vehicle passages. This paper presents an experimental determining of the horizontal dynamic movements of water tower reservoirs by GB-RAR. Determining the dynamic movements of water tower reservoirs is more complicated precisely because the movement of the reservoir is influenced not only by external influences, such as wind, but also by the movement of water mass in the reservoir. The resulting oscillation is then a composite oscillation of multiple frequencies. Next, in the case of routine determination of vertical deflections of bridge structures, it is reasonable to assume a predominant deflection of the structure in this one particular direction. But in the case of tower structures such as reservoirs, it is necessary to assume their movements (oscillations) in the entire horizontal plane. The movements can be circular, elliptical, straight, spiral, or even completely irregular. This means using at least two radars to simultaneously determine 2D movements (in both perpendicular directions of the horizontal plane). In the optimal case, the radars aim at the monitored object in approximately perpendicular directions to each other, and the resulting motion vectors in the horizontal plane are calculated from LOS measurements. The processing of measurements from both radars raises other problems, namely accurate time synchronization of radar measurements. In case of tower structures, time synchronization cannot be solved by coincidence of oscillation amplitude peaks, since the peaks from different radar views may not occur simultaneously. Therefore, alternative solution is offered in this contribution. Purpose of this contribution is to design and verify a procedure for accurate determination of horizontal movements of tower reservoirs with sufficiently accurate oscillation characteristics. The procedure was experimentally verified in practice on a real water reservoir in central Bohemia. The results of the experiment confirm the expected benefits of simultaneous measurements by two radars for determining horizontal dynamic movements of water tower reservoirs by GB-RAR.

Flow dynamics of droplets expelled during sneezing.

Respiratory infections transmit through droplets and aerosols generated by the infected individual during respiratory emissions. It is essential to study the flow dynamics of these emissions to develop strategies for mitigating the risk of infection. In particular, the dynamics of droplets expelled during violent exhalations such as sneezing is crucial, but has received little attention to date. Here, for the first time, we present the results of droplet dynamics of 35 sneezes, obtained from four volunteers, using particle tracking velocimetry experiments. Our results reveal a mean droplet velocity of 2–5.4 m/s across the different subjects. These values are significantly lower than what is usually assumed in the studies simulating or replicating sneezes. Furthermore, the large variation in droplet speeds, flow direction, spread angle, and head movement is also quantified. These findings will enable the refinement of models and simulations of sneezes toward improving infection control guidelines.

Amplification Effect of Ground Motion in Offshore Meandering Sedimentary Valley

A sedimentary valley has a visible amplification effect on a seismic response, and the current 2D topographies cannot truthfully reflect the twists and turns of a large-scale river valley. Taking a sinusoidal curved valley site as a model, the dynamic finite element analysis method and the introduction of a viscoelastic artificial boundary were developed to study the 3D seismic response of the dimensional topographies in the homogeneous curved valley to vertical incident P, SV, and SH waves. The results showed that the bending sedimentary valley site earthquake presented significant features simultaneously, depending on the number of valley bends, the frequency of the excitations, the shear wave velocity of sedimentary soil, and the depth of the river valley. The surface displacement amplitudes of three-dimensional meandering sedimentary valleys are significantly different from those of sedimentary basins. The amplification area of the meandering valley is related to the angle between the valley axis and wave vibration direction, and the amplification effect is significant when the angle is small. The movement in the main direction showed a center focus, and the secondary y-direction displacement showed both a central focus and an edge effect. When the frequency of the incident wave was close to the natural vibration frequency in a specific direction, the movement in this direction significantly increased because of the resonance effect. The displacement amplitude of the surface was proportional to the depth of the river valley, and the surface displacement was presented in different forms based on the frequency of the excitations. The results provided some guidance for the earthquake resistance of the curved valley site.

Numerical investigation of two degree-of-freedom galloping oscillation of a cylinder attached with fixed fairing device

Fairing is one of the most effective devices to suppress vortex-induced vibration (VIV) of marine risers. However, when the rotational friction coefficient of the fairing device is too high to rotate, severe galloping oscillations occurs. In this paper, a two-dimensional mass-spring-damping system was constructed based on the commercial software ANSYS. The galloping mechanism and the two degree-of-freedom (DOF) galloping characteristics of the fairing were studied by numerical methods. In particular, the influence of the natural frequency ratio of the in-line (IL) direction and the cross-flow (CF) direction on the galloping oscillation was discussed. The mass ratio of the riser-fairing system for which the simulations were performed was 1.7, and the damping ratio was 0.003. The Reynolds number based on the cylinder diameter and the inflow velocity was 1000. The range of reduced velocities based on the natural frequency in the CF direction was 1.76–18.52. The results showed that the activation of the inherent modes of the structure and the reattachment of the shear layer in the wake had an important contribution to the generation of the galloping. The movement in the IL direction could promote the reattachment of the shear layer to a certain extent, thereby expanding the scope of the galloping conditions. When the natural frequency ratio was equal to 1 or 2, a “double peak” phenomenon was found in the vibration amplitude curve in the CF direction. In the 2-DOF vibration, the fairing moved in the shape of an “8″ or a drop-shaped trajectory in most cases. On the whole, the interaction between the movement of the fairing in the IL direction and the movement in the CF direction could not be neglected, and the natural frequency ratio also significantly affected the vibration characteristics.

Exact solution for the Anisotropic Ornstein–Uhlenbeck process

Active-Matter models commonly consider particles with overdamped dynamics subject to a force (speed) with constant modulus and random direction. Some models also include random noise in particle displacement (a Wiener process), resulting in diffusive motion at short time scales. On the other hand, Ornstein–Uhlenbeck processes apply Langevin dynamics to the particles’ velocity and predict motion that is not diffusive at short time scales. Experiments show that migrating cells have gradually varying speeds at intermediate and long time scales, with short-time diffusive behavior. While Ornstein–Uhlenbeck processes can describe the moderate-and long-time speed variation, Active-Matter models for over-damped particles can explain the short-time diffusive behavior. Isotropic models cannot explain both regimes, because short-time diffusion renders instantaneous velocity ill-defined, and prevents the use of dynamical equations that require velocity time-derivatives. On the other hand, both models correctly describe some of the different temporal regimes seen in migrating biological cells and must, in the appropriate limit, yield the same observable predictions. Here we propose and solve analytically an Anisotropic Ornstein–Uhlenbeck process for polarized particles, with Langevin dynamics governing the particle’s movement in the polarization direction and a Wiener process governing displacement in the orthogonal direction. Our characterization provides a theoretically robust way to compare movement in dimensionless simulations to movement in experiments in which measurements have meaningful space and time units. We also propose an approach to deal with inevitable finite-precision effects in experiments and simulations.

Comparison of Stress Fields near Longitudinal Construction Joints of Tied and Doweled Sections in Portland Cement Concrete Pavements

In Portland cement concrete (PCC) pavements, tie bars are commonly used at longitudinal construction joints (LCJs) to prevent the lanes from separating. Meanwhile, the increase in multiple lanes due to greater traffic volumes has raised concerns about potential longitudinal cracking; this has led to the use of dowel bars instead of tie bars at LCJs. However, there is a paucity of studies focused on the comparison between the behaviors of concrete pavement based on the restrained conditions provided by tie and dowel bars at LCJs. In this study, we investigated the effects of the placement of tie and dowel bars at LCJs on the potential for longitudinal cracking in response to the increase in concrete stress that may occur when the lanes are tied together in PCC pavements. Field testing verified that the variation in concrete strain was more restrained in the case of a tie bar than a dowel bar, whereas it resulted in higher stress in the concrete element in the tie bar section. However, the use of dowel bars caused more movement in the transverse direction at LCJs as compared with tie bars. Thus, our results indicate that using dowel bars reduces the potential for longitudinal cracking; however, it may increase the potential for lane separation.

Occurrence of heatwave in Korea by the displacement of South Asian high

The South Asian high (SAH) index was defined using the 200 hPa geopotential height for 1973–2019. Of the movements of the SAH center in the north–south, east–west, northwest-southeast, and southwest-northeast directions, the movements in the northwest-southeast direction showed the highest positive correlation with heatwave days (HWDs) in South Korea. Thirteen years with the highest values in the northwestward shift of the SAH (positive SAH years) and 13 years with the highest values in the southeastward shift of the SAH (negative SAH years) were selected from a time series of SAH indices from which the linear trend was removed, and the differences between these two groups were analyzed. An analysis of vertical meridional circulation averaged along 120°–130° E showed that in the latitude zones containing Korea, anomalous downward flows with anomalous high pressures formed in the entire troposphere and coincided with a positive anomaly of air temperature and specific humidity. An analysis of stream flows and geopotential heights showed that in the positive SAH years, anomalous anticyclones developed in Korea, the North Pacific, North America, Western Europe, and the Iranian Plateau. These anticyclones had the wavenumber-5 pattern and showed more distinct barotropic vertical structures at higher altitudes, which resembled the circumglobal teleconnection (CGT) pattern. The maintenance of CGT depends on the interaction between the CGT circulation and the Indian summer monsoon (ISM), which has a major influence on the mid-latitude atmosphere. Strengthening of the ISM results in the formation of upper-level anomalous anticyclones in the northwestern Iranian Plateau and produces continuous downstream cells along the waveguide due to the Rossby wave dispersion. When diabatic heating by Indian summer monsoon precipitation is strengthened, the SAH is strengthened to the northwest of India, and a positive CGT pattern is formed. As a result, anomalous anticyclones formed in all layers of the Korean troposphere, resulting in heatwaves, tropical nights, and droughts exacerbated in South Korea.

Brain Cortical Activation during Imagining of the Wrist Movement Using Functional Near-Infrared Spectroscopy (fNIRS).

Background: fNIRS is a useful tool designed to record the changes in the density of blood’s oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) molecules during brain activity. This method has made it possible to evaluate the hemodynamic changes of the brain during neuronal activity in a completely non-aggressive manner.Objective: The present study has been designed to investigate and evaluate the brain cortex activities during imagining of the execution of wrist motor tasks by comparing fMRI and fNIRS imaging methods.Material and Methods: This novel observational Optical Imaging study aims to investigate the brain motor cortex activity during imagining of the right wrist motor tasks in vertical and horizontal directions. To perform the study, ten healthy young right-handed volunteers were asked to think about right-hand movements in different directions according to the designed movement patterns. The required data were collected in two wavelengths, including 845 and 763 nanometers using a 48 channeled fNIRS machine.Results: Analysis of the obtained data showed the brain activity patterns during imagining of the execution of a movement are formed in various points of the motor cortex in terms of location. Moreover, depending on the direction of the movement, activity plans have distinguishable patterns. The results showed contralateral M1 was mainly activated during imagining of the motor cortex (p<0.05).Conclusion: The results of our study showed that in brain imaging, it is possible to distinguish between patterns of activities during wrist motion in different directions using the recorded signals obtained through near-infrared Spectroscopy. The findings of this study can be useful in further studies related to movement control and BCI.

A Review on the Design Rule for the Friction Stir Welding using Bobbin Tool for Aluminum

Friction stir welding using a bobbin tool (BT-FSW) is a kind of friction stir welding (C-FSW) process in which a lower shoulder is added to the general friction stir welding tool. It is known as the useful method to reduce the Z-axis load required during the tool insertion and traveling for FSW. In addition, it can eliminate the backing plate, and actively respond to part deformation. For this reason, research on the application of BT-FSW is expanding from low melting temperature materials such as aluminum and magnesium to high melting temperature materials. However, no relevant studies on BT-FSW can be found in Korea. This study aimed to present tool design guidelines specifically for BT-FSW. Summarized information on variables to be considered when designing the BT-FSW tool has been described, such as pin and shoulder diameter, shoulder gap, pin and shoulder feature. The design of the tool is a significant step in set-up the BT-FSW process, and should be considered according to the material characteristics (viscosity, plasticity…) and thickness. The pin diameter that is similar to the thickness of material, and the shoulder diameter that is 2 to 3 times wider than the pin diameter were recommended. The shoulder gap, the distance between the upper and lower shoulder, is generally machined to match the material's thickness or fabricated to be shallower than. Since the pin shape directly affects the vertical and horizontal direction movement into the stir zone, the pins with 3 to 4 flat faces or threaded are more practical than the cylindrical pin shape.