The Effect of Genders on the Perception of the Combined Effect of Local Discomfort Parameters

If the draught and the radiant thermal asymmetry caused by the warm ceiling appear simultaneously, will women and men be affected in the same way? This research aims to answer this question, by clarifying the understanding of the joint mechanism of action of the two local discomfort factors with the help of instrumental and human subject measurements. The most important result of the present research is identifying that if PPD < 6%, radiant thermal asymmetry varies in the range of 5–15 °C and the draught rate DR = 15% or DR = 25%, then at a given range of the interval men are significantly more dissatisfied with warm ceilings than women; women’s AMV votes are significantly lower than men's; In the case of DR = 15%, the work accuracy of women is significantly higher, while in the case of men, the work accuracy is higher at DR = 25%.

A unique yet technically simple type of joint allows for the high mobility of scorpion tails

Although being one of the most well-known animal groups, functional and constructional aspects of scorpions and especially of their tail (metasoma) have so far been overlooked. This tail represents a special construction, as it consists of five tube-shaped segments made up of strong cuticle, which are movable against each other and thus manoeuvre the notorious stinger both quickly and very precisely in space. This high mobility of an exoskeletal structure can be attributed to the connection between the segments described here for the first time. This joint allows for the twisting and bending at the same time in a single, simple construction: adjoining metasomal segments each possess an almost circular opening posteriorly, where the next segment is lodged. Anteriorly, these segments possess two saddle-like protrusions laterally, which are able to rotate in two directions on the rim of the posterior circular opening of the previous segment allowing for twisting and bending. The metasomal joint is particularly noteworthy since its mechanism can be compared to that of arthropod appendages. The scorpion metasoma is actually the only known case in Chelicerata, in which an entire body section has been modified to perform tasks similar to that of an appendage while containing digestive organs. The joint mechanism can also inspire technical applications, for instance in robotics.

Blower-Powered Soft Inflatable Joints for Physical Human-Robot Interaction

Inflatables are safe and lightweight structures even at the human scale. Inflatable robots are expected to be applied to physical human-robot interaction (pHRI). Although active joint mechanisms are essential for developing inflatable robots, the existing mechanisms are complex in structure and it is difficult to integrate actuators, which diminish the advantages of inflatables. This study proposes blower-powered soft inflatable joints that are easy to fabricate and contain enough space for an actuation inside. The joints are driven by tendon wires pulled by linear actuators. We derived a theoretical model for both unilateral and bilateral joints and demonstrated a hugging robot with multiple joints as an application of the proposed joint mechanism. The novelty of the proposed joint mechanism and the inflatable robot is that rigid parts have been thoroughly eliminated and the tendons for actuation have been successfully hidden inside. Moreover, the active control of the internal pressure makes inflatables resistant to punctures. We expect that the contact safety of inflatable robots will facilitate advancement of the pHRI field.

Steerable Surgical Instrument for Conventional and Single-Site Minimally Invasive Surgery

Background. This article aims to present an innovative design of a steerable surgical instrument for conventional and single-site minimally invasive surgery (MIS), which improves the dexterity and maneuverability of the surgeon while offering a solution to the limitations of current tools. Methods. The steerable MIS instrument consists of a deflection structure with a curved sliding joints design that articulates the distal tip in two additional degrees of freedom (DoFs), relative to the instrument shaft, using transmission by cables. A passive ball-joint mechanism articulates the handle relative to the instrument shaft, improves wrist posture, and prevents collision of instrument handles during single-site MIS procedures. The two additional DoFs of the articulating tip are activated by a thumb-controlled device, using a joystick design mounted on the handle. This steerable MIS instrument was developed by additive manufacturing in a 3D printer using PLA polymer. Results. Prototype testing showed a maximum tip deflection of 60° in the left and right directions, with a total deflection of 120°. With the passive ball-joint fully offset, the steerable tip achieved a deflection of 90° for the right and 40° for the left direction, with a total deflection of 130°. Furthermore, the passive ball-joint mechanism in the handle obtained a maximum range of motion of 60°. Conclusions. This steerable MIS instrument concept offers an alternative to enhance the application fields of conventional and single-site MIS, increasing manual dexterity of the surgeon and the ability to reach narrow anatomies from other directions.

A New Cam-follower Safety Joint Mechanism Design based on Variable-length Four-bar Linkage for Robot Safety

Humans come into physical contacts with various machines such as robots in daily life. This leads to the underlying issue of guaranteeing safety during such human-robot interactions. Thus, many devices and methods have been studied for impact damage reduction. A safety joint mechanism (SJM) using four-bar linkages has been highlighted as an impact cutoff device owing to its capabilities of nonlinear load transfer. This paper focuses on a new design and testing for a kinematic element of an SJM based on four-bar linkages to improve the impact cutoff performances. In the present work, a set of variable-length floating link designs is proposed, and the mechanism is implemented by mechanical contact surface profile shaping between the cams and followers. The performance of the cam-follower mechanism is evaluated depending on the variable length of the floating link, by using equivalent stiffness method, which successfully quantifies the performance of the proposed mechanism. Based on this design and analysis, two SJMs having symmetrical arrangements for four numbers of cam-follower mechanisms are fabricated: one SJM has fixed-length floating links and the other has variable-length floating links. The effect of the new kinematic elements on the performance improvement is verified by comparing the absorbed impact rates of the two SJMs by impact hammer-like drop tests. Consequently, it is confirmed that the rapid length change of the floating link is the core element for improving the performance of the safety mechanism.

The impacts of ambidextrous innovation on organizational obsolescence in turbulent environments

PurposeThe authors aim to measure the effects of ambidextrous innovation and its mix strategy on organizational obsolescence with the moderating roles of environmental turbulence.Design/methodology/approachHierarchical regression analysis was used to test the hypotheses on the basis of the survey data of 198 firm employees in China.FindingsBoth exploratory and exploitative innovations significantly restrain organizational obsolescence. The complementary strategy of ambidextrous innovation is negatively correlated to organizational obsolescence, but the impact of balanced strategy is not significant. Environmental turbulence negatively moderates the relationship between exploratory innovation and organizational obsolescence, whereas it cannot moderate the effect of exploitative innovation.Originality/valueThe empirical and conceptual findings have important implications for organizations countering obsolescence through the construction of a mix strategy of ambidextrous innovation. This study enriches and extends obsolescence theory by introducing the joint mechanism of ambidextrous innovation and environmental turbulence.

Development And Research Of The Press Operating Mechanism, Made In The Form Of The Wedge-Joint Mechanism With A Curving Wedge For Separation Operations

The applicability of a wedge-joint mechanism with a curving wedge in presses for the implementation of metal forming separation processes was substantiated. The paper states the fact, that the wedge-joint mechanism graph of the deformation force change is the closest to the technological typical graph of the force change during separation. At the same time, the wedge-joint mechanism with a curving wedge has a lower height of the parts in comparison with the traditional crank mechanisms, which provides less elastic deformation and press dynamics. The use of the additional wedge mechanism in a press with the wedge-joint mechanism with a curving wedge to ensure the approximation motion is proved. This makes it possible to reduce the energy consumption for elastic deformation and further reduce the dynamic force. The mathematical models of the wedge-joint mechanism with a curving wedge, presented in the form of a two-slide link mechanism, were developed, allowing to perform its structural, kinematic and dynamic analysis. Based on the analysis of the proposed mathematical models, dependencies were identified and a procedure for calculating the geometric, kinematic and power parameters of wedge-joint mechanisms with a curving wedge for separation processes was developed. Comparison of the kinematic and dynamic analyzes results carried out by analytical and graphic-analytical methods confirms the reliability of estimates, since their discrepancy is not more than 2.5%. Experimental studies have confirmed the adequacy of mathematical models. The error between the calculated and measured values ​​of the forces on the slide does not exceed 10%.