Human Body Simulation Within a Hybrid Operating Method for a Safe and Efficient Human-Robot Collaboration

The planning and integration of production systems with a direct human-robot collaboration (HRC) is still associated with various technical challenges. This applies especially to the realization of the operation methods speed and separation monitoring (SSM) as well as power and force limiting (PFL). Due to the limited consideration of the human motion behaviour, the required dynamic separation distance in SSM is frequently oversized in practice. The main consequences are wasted space as well as cycle time and performance losses within the corresponding HRC application. In PFL a physical contact between the operator and robot is permissible, taking into account specified biomechanical thresholds. However, there is still a lack of suitable use-cases since the maximum permissible speeds are on a very low level. Moreover some thresholds regarding the transient contact case are still non-applicable for critical body areas (e.g. temple, middle of forehead). The study of this paper is related to a kinematic state determination of the human operator within a new hybrid collaborative operation. In this method the SSM type is extended regarding the description of the operator and coupled with the two-body contact model of the PFL. Using a planning and simulation tool for HRC, the kinematic states of different body regions are derived from an integrated and parameterized digital human model. Afterwards, these body regions are mapped to the characteristic body areas of the ISO/TS 15066, whereby the resulting information will be applied in an adaptive robot speed control. The performance of the presented concept will be evaluated using an exemplary simulated HRC scenario.

Contact improvisation in the context of social dance of the XX century: features of the open dance form "jam"

Contact improvisation in the context of social dance of the XX century: features of the open dance form "jam" The purpose of the article is to reveal the features of contact improvisation as a practice of social dance of the XXI century and to determine the specifics of its implementation in the unique dance form "jam". Research methodology. A comprehensive method of studying the features of contact improvisation in the context of a social dance of the XXI century, a historical method, thanks to which the details of the development of contact improvisation have been clarified; the method of functional and systems analysis, which contributed to the study of contact improvisation as a unique hybrid practice; a phenomenological method that helped to highlight the essential features and identify the key elements of contact improvisation in the dance form "jam", etc. The scientific novelty consists in expanding the theoretical basis for analyzing the phenomenon of contact improvisation; clarifying the concept of "contact improvisation"; the features of the practice of contact improvisation in the context of the specificity of social dance are investigated on the basis of the analysis of its physical and mental components; analyzed the main elements of contact improvisation (inaction, weighing/carrying, falling, playing, discussing, observing, touching) through the prism of the unique open dance form "jam". Conclusions. Contact improvisation is based on communication between two moving bodies that are in physical contact, and the cumulative relationship of physical laws governing their motion - the laws of gravity, momentum, and inertia. In accordance with the specifics of social dance, contact improvisation is a tool for studying one's own capabilities, a model of human relations and meditative practice, which creates the preconditions for further development, providing a huge space of freedom and ease of performance of one or another dance element, removes the restrictions imposed by choreography, allows you to move like this, as the dancer wants, without tension, provides new material for self-knowledge and exploration of relationships, is a source of inspiration and a way of expressing the creative energy that is in the body. Contact improvisation, as a hybrid practice, works at the crossroads between body meditation, psycho-kinesthetic therapy, sports training, and dance improvisation and, in the context of the specifics of social dance, is implemented at improvisational meetings of contactees, the so-called jams, at the local and national level. Keywords: contact improvisation, social dance, jams, dance practice, dance form.

3D virtual fit assessment and modeling: liquid cooling and ventilation garment

PurposeThe suboptimal fit of a spacesuit can interfere with a crewmember's performance and is regarded as a potential risk factor for injury. To quantify suit fit, a virtual fit assessment model was previously developed to identify suit-to-body contact and interference using 3D human body scans and suit CAD models. However, ancillary suit components and garments worn inside of the suit have not been incorporated.Design/methodology/approachThis study was conducted to predict a 3D model of the liquid cooling and ventilation garment (LCVG) from an arbitrary person's body scan. A total of 14 subjects were scanned in a scan wear and LCVG condition. A statistical model was generated using principal component analysis and random forest regression technique.FindingsThe model was able to predict the geometry of the LCVG layer at the accuracy of 5.3 cm maximum error and 1.7 cm root mean square error. The errors were more pronounced for the arms and lower torso, while the thighs and upper torso regions, which are critical for suit fit assessments, show more accurate predictions. A case study of suit fit with and without the LCVG model demonstrated that the new model can enhance the scope and accuracy of future spacesuit assessments.Originality/valueThe capabilities resulting from these modeling techniques would greatly expand the assessments of fit of the garment on various anthropometries. The results from this study can significantly improve the design process modeling and initial suit sizing efforts to optimize crew performance during extravehicular activity training and missions.

Extracting multi-way chromatin contacts from Hi-C data

There is a growing realization that multi-way chromatin contacts formed in chromosome structures are fundamental units of gene regulation. However, due to the paucity and complexity of such contacts, it is challenging to detect and identify them using experiments. Based on an assumption that chromosome structures can be mapped onto a network of Gaussian polymer, here we derive analytic expressions for n-body contact probabilities (n > 2) among chromatin loci based on pairwise genomic contact frequencies available in Hi-C, and show that multi-way contact probability maps can in principle be extracted from Hi-C. The three-body (triplet) contact probabilities, calculated from our theory, are in good correlation with those from measurements including Tri-C, MC-4C and SPRITE. Maps of multi-way chromatin contacts calculated from our analytic expressions can not only complement experimental measurements, but also can offer better understanding of the related issues, such as cell-line dependent assemblies of multiple genes and enhancers to chromatin hubs, competition between long-range and short-range multi-way contacts, and condensates of multiple CTCF anchors.

KNEE INJURIES PREVALENCE IN BRAZILIAN JIU-JITSU: EPIDEMIOLOGICAL STUDY

ABSTRACT Objective: To evaluate the epidemiological and clinical characteristics of knee injuries in Brazilian Jiu-Jitsu (BJJ) practitioners. Methods: Cross-sectional study, using a mixed questionnaire, based on the Referred Morbidity Index. Results: 198 amateur and professional BJJ fighters, of both sexes, aged between 18 and 60 years, participated in the study. The majority (88%) of the fighters had only one knee injury (p < 0.001). In total, 29.8% proportion of knee injuries (p < 0.001) was identified, which were mainly from the medial collateral ligament (38%), caused by a sprain mechanism (86%) and conservative treatment (65%). Conclusion: A high prevalence of knee injuries in JJB fighters was found, compared to other sports that also perform rotational movements and have great body contact, such as mixed martial arts (MMA), judo, soccer, basketball and handball. Some JJB strikes, such as the key and the projection, can cause greater knee joint stress, both in the attacking fighter and in the opponent. The knowledge of the epidemiological characteristics of sports injuries is important in the elaboration of prevention and training protocols more specific to the sport and for the understanding of the complex mechanisms involved with this outcome in sport. Level of Evidence IV, Case Series.

Dance

The study of dance can be summed up as the four Ps: patterning, partnering, pacing, and person. Patterning is about the intra- and interpersonal processes used in creating complex movement patterns in space and time. Partnering in dance involves the coordinated movement of multiple dancers, generally in defined spatial configurations, sometimes occurring through direct body contact. Next, pacing in dance refers to the synchronization of movement patterns with both musical beats and interaction partners. Finally, the person aspect of dance deals with how dancers are able to engage in acting by portraying characters in narrative forms of dance and to tell stories with their bodies in a wordless manner using iconic and affective gestures.

High Cod and Turbidity Removal in The Treatment of Polluted Pond Water Using Low Dosage of Pineapple Leaf Coagulant: A Preliminary Study

Coagulation process using low dosage of plant-based coagulant to remove high chemical oxygen demand (COD) and turbidity is important for water treatment. This study presents the treatment of pond water using plant-based pineapple leaf coagulant to achieve high COD and turbidity removal. The coagulation was performed using a jar test experiment of pond water at different pH followed by different dosages of pineapple leaf coagulant. It was found that the highest COD and turbidity removal ranged between 94.1 – 94.6 % and 88.3 – 88.4 % at pH 8 respectively, using low dosage (50 mg L-1) of pineapple leaf coagulant. The final COD and turbidity values ranged between 7.3 – 8.0 mg L-1 and 17.7 – 17.8 formazin turbidity unit (FTU) respectively, which are lower compared with results from other studies that used high dosage coagulants. Moreover, the final pH, COD, turbidity, dissolved oxygen (DO), and total suspended solid (TSS) values of the treated pond water were below the standard limits set by the National Water Quality Standards for Malaysia (NWQSM) class IIB, which represents water bodies suitable for recreational use with body contact (DOE, 2016). Therefore, it is expected that the newly-formulated waste utilisation of pineapple leaf coagulant can reduce the usage of chemical coagulants and can further be used for different types of water.

Carbon-Based Coatings in Medical Textiles Surface Functionalisation: An Overview

The COVID-19 pandemic has further highlighted the need for antimicrobial surfaces, especially those used in a healthcare environment. Textiles are the most difficult surfaces to modify since their typical use is in direct human body contact and, consequently, some aspects need to be improved, such as wear time and filtration efficiency, antibacterial and anti-viral capacity, or hydrophobicity. To this end, several techniques can be used for the surface modification of tissues, being magnetron sputtering (MS) one of [hose that have been growing in the last years to meet the antimicrobial objective. The current state of the art available on textile functionalisation techniques, the improvements obtained by using MS, and the potential of diamond-like-carbon (DLC) coatings on fabrics for medical applications will be discussed in this review in order to contribute to a higher knowledge of functionalized textiles themes.

Tribological characteristics and load-sharing of point-contact interface in three-body mixed lubrication

The third particle occurred at the interface of contacting surfaces is common situations in relative motion part. This study involved developing an analysis framework to investigate the contact characteristics in the full range of 3-body mixed lubrication. Conventional 2-body mixed lubrication is a special case of 3-body mixed lubrication analysis with particle size of zero. This study revealed that the values of real contact area, film thickness, contact mode, and the solid contact load in 3-body contact were larger than those in ideal 2-body contact in mixed lubrication, and they increased with an increasing particle size or density under the study conditions. The initial stages and transition processes of four types of 3-body contact modes under mixed lubrication were significantly different for different particle sizes and densities. The size of the third particle increased the values of both minimum and maximum values, λmin and λmax, of film parameter in the mixed lubrication regime. The particle density did not have a significant effect on the λmax value in mixed lubrication. Higher particle density led to a larger λmin value in mixed lubrication. The conventional film parameter, λ, was not a sufficient indicator of the different lubrication regimes in 3-body contact.

Extracting multi-way chromatin contacts from Hi-C data

There is a growing realization that multi-way chromatin contacts formed in chromosome structures are fundamental units of gene regulation. However, due to the paucity and complexity of such contacts, it is challenging to detect and identify them using experiments. Based on an assumption that chromosome structures can be mapped onto a network of Gaussian polymer, here we derive analytic expressions for n-body contact probabilities (n > 2) among chromatin loci based on pairwise genomic contact frequencies available in Hi-C, and show that multi-way contact probability maps can in principle be extracted from Hi-C. The three-body (triplet) contact probabilities, calculated from our theory, are in good correlation with those from measurements including Tri-C, MC-4C and SPRITE. Maps of multi-way chromatin contacts calculated from our analytic expressions can not only complement experimental measurements, but also can offer better understanding of the related issues, such as cell-line dependent assemblies of multiple genes and enhancers to chromatin hubs, competition between long-range and short-range multi-way contacts, and condensates of multiple CTCF anchors.