Horizontal Handle Research Articles

Grid-Map-Based Path Planning and Task Assignment for Multi-Type AGVs in a Distribution Warehouse

In an intelligent distribution warehouse, latent AGVs are used for horizontal handling, and forklift AGVs are used for horizontal or vertical handling. Studying the path planning and task assignment problem when the two types of AGVs are mixed can help improve the warehouse operation efficiency and reduce the warehouse operation cost. This paper proposes a two-stage optimization method to solve this problem. In the first stage, the warehouse plan layout is transformed into a raster map, and the shortest path between any two points of the warehouse without conflict with fixed obstacles is planned and stored using the A* algorithm combined with circular rules, and the planned shortest path is called directly in the subsequent stages. In the second stage, to minimize the task completion time and AGV energy consumption, a genetic algorithm combining penalty functions is used to assign horizontal handling tasks to submerged AGVs or forklift AGVs and vertical handling tasks to forklift AGVs. The experimental results show that the method can meet the 24 h operation requirements of an intelligent distribution warehouse and realize the path planning and task assignment of forklift AGVs and latent AGVs. And furthermore, the number of AGVs arranged in the warehouse can be further reduced.

Alteration in HDEMG Spatial Parameters of Trunk Muscle Due to Handle Design during Pushing.

Previous research identifies that pushing and pulling is responsible for approximately 9–18% of all low back injuries. Additionally, the handle design of a cart being pushed can dramatically alter a worker’s capacity to push (≅9.5%). Surprisingly little research has examined muscle activation of the low back and its role in muscle function. Therefore, the purpose of this study was to examine the effects of handle design combination of pushing a platform truck cart on trunk muscle activity. Twenty participants (10 males and 10 females, mean age = 24.3 ± 4.3 years) pushed 475 lbs using six different handle combinations involving handle orientation (vertical/horizontal/semi-pronated) and handle height (hip/shoulder). Multichannel high-density EMG (HDsEMG) was recorded for left and right rectus abdominis, erector spinae, and external obliques. Pushing at hip height with a horizontal handle orientation design (HH) resulted in significantly less (p < 0.05) muscle activity compared to the majority of other handle designs, as well as a significantly higher entropy than the shoulder handle height involving either the semi-pronated (p = 0.023) or vertical handle orientation (p = 0.028). The current research suggests that the combination of a hip height and horizontal orientation handle design may require increased muscle demand of the trunk and alter the overall muscle heterogeneity and pattern of the muscle activity.

Prevalence of abnormal findings in 230 knees of asymptomatic adults using 3.0\xa0T MRI

ObjectiveTo identify abnormalities in asymptomatic sedentary individuals using 3.0 Tesla high-resolution MRI.Materials and methodsThe cohort comprised of 230 knees of 115 uninjured sedentary adults (51 males, 64 females; median age: 44 years). All participants had bilateral knee 3.0 T MRIs. Two senior musculoskeletal radiologists graded all intraarticular knee structures using validated scoring systems. Participants completed Knee Injury and Osteoarthritis Outcome Score questionnaires at the time of the MRI scan.ResultsMRI showed abnormalities in the majority (97%) of knees. Thirty percent knees had meniscal tears: horizontal (23%), complex (3%), vertical (2%), radial (2%) and bucket handle (1%). Cartilage and bone marrow abnormalities were prevalent at the patellofemoral joint (57% knees and 48% knees, respectively). Moderate and severe cartilage lesions were common, in 19% and 31% knees, respectively, while moderate and severe bone marrow oedema in 19% and 31% knees, respectively. Moderate-intensity lesion in tendons was found in 21% knees and high-grade tendonitis in 6% knees—the patellar (11% and 2%, respectively) and quadriceps (7% and 2%, respectively) tendons being most affected. Three percent partial ligamentous ruptures were found, especially of the anterior cruciate ligament (2%).ConclusionNearly all knees of asymptomatic adults showed abnormalities in at least one knee structure on MRI. Meniscal tears, cartilage and bone marrow lesions of the patellofemoral joint were the most common pathological findings. Bucket handle and complex meniscal tears were reported for the first time in asymptomatic knees.

Una vasija decorada ibérica de función ceremonial: un espacio singular en el Coll del Moro (Gandesa, Tarragona).

Se presenta un vaso ibérico del siglo III ane excepcionalmente decorado procedente del ámbito 8 del poblado del Coll del Moro de Gandesa (Tarragona). Se trata de una marmita cerámica de cierre hermético, elaborada a mano, de perfil globular, con dos asas horizontales torsionadas y profusa decoración geométrica y zoomorfa. Presenta un asa de pomo, maciza, subcuadrangular, que está decorada en cada uno de sus cuatro ángulos superiores con motivos plásticos, sendas cabezas de carnero estilizadas. El fondo interno de la vasija está decorado con una cruz esvástica en altorrelieve. Tanto el carnero como la cruz, los dos elementos decorativos más sobresalientes de la pieza, tienen un arraigado simbolismo relacionado con el culto al hogar y a los antepasados. La función de la vasija es, sin lugar a dudas, ritual. Entronca con cultos al hogar y a los antepasados ya atestiguados en la protohistoria de la Península Ibérica y pone de manifiesto que en el ámbito en el que se hallaba se desarrollaban ceremonias de culto. Dicho ámbito se ubica en lo que podemos llamar un barrio productivo o industrial del asentamiento donde se ha exhumado un conjunto arquitectónico dedicado al enriado del lino y a otras actividades textiles y otro dedicado a lagar y almacenaje de vino. El hallazgo aporta nuevas perspectivas sobre las actividades ceremoniales y el mobiliario de culto en el nordeste peninsular, tan avaro respecto a este tipo de información.

Склеп “македонського типу” з некрополя Німфею

Склеп “македонського типу” з некрополя Німфею

Role of MRI in predicting meniscal tear reparability.

To elucidate the role of MRI in predicting meniscal tear reparability according to tear type and location in relation to vascular zones. In this retrospective study, two readers evaluated 79 pre-surgical MRIs of meniscal tears arthroscopically treated with meniscectomy or meniscal repair. Tears were classified according to type into vertical, horizontal, radial, complex, flaps and bucket handle and were considered reparable if the distance measured from the tear to the menisco-capsular junction was less than or equal to 5mm. Predictions were compared with the surgical procedure performed in arthroscopy. We assessed the diagnostic performance of MRI, agreement between MRI and arthroscopy, and interrater agreement. Then, we conducted an ROC analysis on the distances measured by the first reader and built a multivariate logistic regression model. MRI had a sensitivity, specificity, PPV, NPV and accuracy, respectively, of 85%, 79%, 86%, 76% and 83% in predicting meniscal tear reparability. Correct predictions for the specific tear pattern were 76% for vertical, 84% for horizontal, 88% for radial, 86% for complex, 84% for flaps and 86% for bucket handle. Agreement between the two readers' predictions and arthroscopy was good (k=0.65 and 0.61, respectively). Inter-rater agreement was almost excellent (k=0.79). The ROC analysis revealed sensitivity and specificity of 73% and 83% with a cutoff value of <4mm (p<0.001). Anterior cruciate ligament injury and medial meniscal tear increased the likelihood of meniscal tear reparability. MRI can be a reliable and accurate tool to predict the reparability of meniscal tears, with higher prediction rates for bucket-handle tears.

수직형 손잡이와 수평형 손잡이의 높이와 간격에 따른 미는 힘 비교

Manual materials handling tasks are the main risk factors for the work-related musculoskeletal disorders. Many assistant tools for manual materials handling are being used in various kind of industries. One of them is a 4-wheeled cart which is widely used in manufacturing factories, hospitals, etc. The major force required to control the 4-wheeled cart is pushing and pulling. There are two types of handles being used for the 4-wheeled cart : vertical type (two vertical handles), and horizontal type (one horizontal handle). This study tried to investigate the pushing forces and subjective discomforts (hand/writst, shoulder, low back, and overall) of the two handle types with different handle height and distance conditions. Twelve healthy male students (mean age = 23.4 years) participated in the experiment. The independent variables were handle angle (horizontal, vertical), handle height (low, medium, high), and handle distance (narrow, medium, wide). The full factorial design was used for the experiment and the maximum pushing forces were measured in 18 different conditions (2×3×3). Analysis of variance (ANOVA) procedure was conducted to test the effects of the independent variables on the pushing force and discomfort levels. Handle height and angle were found to be the critical design factors that affect the maximal pushing forces and subjective discomfort. In the middle height, subjects exerted higher pushing forces, and experience lower discomfort levels compared to the high, and low height. There was no statistical influence of the handle distance to the pushing forces and subjective discomfort levels. It was found out that the effects of the handle angle (horizontal and vertical) on both pushing force and subjective discomfort were statistically significant (p < 0.05). The vertical handle revealed higher pushing force and lower discomfort level than the horizontal handle. The reason for that was thought to be the different postures of the hand when grasping the handles. The horizontal handle induced pronaton of the hand and made hand posture more deviated from the neutral position. Keyword : Handle design, Handle angle, Handle height, Handle distance, Maximal pushing force †이 논문은 2014년 대구가톨릭대학교 교내 연구지원금에 의한 것임 †Corresponding Author : Young-Woong Song, 13-13 Hayang-ro, Hayang-eup, Gyeongsan-si, Gyeongbuk, Korea 712-702 Received October 20, 2014; Revision Received December 12, 2014; Accepted December 18, 2014. 수직형 손잡이와 수평형 손잡이의 높이와 간격에 따른 미는 힘 비교 송 영 웅 372

Comparing Manned and Automated Horizontal Handling Equipment at Container Terminals

The choice to use horizontal handling transport in automated container terminals is not fully consistent in comparison with the automation of stacking cranes at the storage yard. Often the decision of whether to use an automated system between the berth and the yard area is not clear, and terminal operators tend not to use automated systems. The goal of this paper is to provide an economic analysis to determine under which conditions automated horizontal transport is more efficient than a semiautomated system. The study provided several simulation models to calculate the optimal equipment necessary to connect storage and berth subsystems in a maritime container terminal in fully automated and semiautomated scenarios. Data from the semiautomated container terminal at the Port of Barcelona, Spain, were used. In addition to the cost analysis, guidelines on the best alternative, considering labor costs, throughput movements per quay crane and year, and quay crane productivity are provided.

Vertical Force and Wrist Deviation Angle in a Sample of Elderly People Using Walkers

Walkers are frequently used by elderly people with weak lower limbs and limited balance, but the ergonomic relationship between the use of a walker and stress on the upper limbs is relatively unstudied. The current study assessed wrist deviation and vertical force among elderly individuals using a walker for assistance in walking. 60 elderly volunteers (M age = 81.0 yr., SD = 8.8) participated, 30 of whom frequently used a walker, and 30 who had no such prior experience. Data were obtained from four load cells and a twin-axis wrist goniometer during assisted ambulation using the walker. No significant group difference was found in gait cycle. Significant wrist deviation occurred, with ulnar deviation/dorsiflexion of the right hand, which was greater than that of the left. Non-experienced participants had larger dorsiflexion than experienced participants. Experienced participants produced larger vertical force than non-experienced participants. The greaterthe wrist deviation, the greater was the vertical force. The horizontal handles of most marketed walkers cause wrist deviations. This is a concern for users, clinicians, and related industries. Improvements in walker design should be considered.

Multi-digit coordination during lifting a horizontally oriented object: synergies control with referent configurations

We explored digit coordination during the acceleration phase of a quick lifting movement of a hand-held horizontal object. We tested three hypotheses related to: (1) the scaling of mechanical variables produced by the hand with changes in the external load, torque, and moment of inertia; (2) changes in the safety margin for the thumb with both the loading conditions and acceleration; and (3) changes in the indices of synergies. The subjects held a horizontal handle with a prismatic grasp (the thumb acted on top of the handle) and performed series of "very quick" lifting movements to a visual target. Multi-digit synergies were quantified as co-variation indices among elemental variables (forces and moments produced by individual digits). The resultant force scaled with the external load but not torque, while the grip force scaled with the external torque but not load. The safety margin dropped with an increase in acceleration; it also showed changes with the external torque and moment of inertia. Total moment of force was primarily produced by the tangential forces (over 80 %) across all movement phases and loading conditions. The index and little fingers produced close to zero moment with their normal forces, while the middle and ring fingers produced consistent moments due to the reproducible shifts of their centers of pressure. Synergy indices at the upper level of the assumed hierarchy (the task is shared between the thumb and virtual finger--an imagined digit with the action equal to that of the four fingers combined) did not drop with acceleration for the three force vector components and one of the moment vector components. They did drop with acceleration at the lower level (virtual finger action is shared among the four fingers). There was a trade-off between synergy indices computed at the two levels for the three force vector components, but not for the moment of force components. We confirmed specialization of different fingers with respect to different task components in quick manipulation tasks. The findings have implications for hypotheses on the control of voluntary movements involving redundant sets of effectors. Within the referent configuration hypothesis, components of a referent configuration may be adjusted to task mechanical characteristics using simple scaling rules. The neural organization of multi-digit synergies in a hierarchal system is able to selectively protect synergies related to stabilization of some performance variables from detrimental effects of the rate of change of those variables. A large number of apparently redundant elemental variables are not the source of additional computational problems but may be beneficial, allowing the central nervous system to facilitate synergies at both levels of the hierarchy.

Using walker during walking:a pilot study for health elder

Walker operation completely relies on the walker handle, however most marketed walkers possess two horizontal handles. Several researchers have suggested that horizontal handles might lead to wrist injury. Therefore, the purpose of this study is to assess the relevant design aspects of walker for elderly people. 28 elders participated in this study; when the experiment was started, subject walked on the tile for 3 meter distance twice by using walker. Data for analysis were selected at the corresponding wrist deviation and vertical force. The results showed that during walker using, the mean wrist deviation was greater than zero. The largest vertical force is significantly larger than the smallest one, and different wrist deviation occurred at three phases, the largest wrist deviation while raising walker is larger than the smallest one, however, no significant different was found between the largest and smallest wrist deviation while pressing walker. No significant correlation occurred between weight and wrist deviation. The correlation between weight and vertical force was significantly positive. With wrist deviation walker use may cause injury to upper-limb, however wrists remain in a neutral position during hand movement to prevent damage. The findings of this study should improve the design of walker handles to reduce the wrist deviations of users.

Vertical Force and Wrist Deviation Angle When Using a Walker to Stand UP and Sit down

Research investigating walkers suggests that safety and assistance for the elderly with weak lower limbs were important. However, the relationship between the use of a walker and the upper limbs has received little investigation. Standing up and sitting down are important daily activities. Therefore, the aim of this study was to explore wrist deviation and vertical force among elderly individuals using a walker for assistance to stand up and sit down. In total, 64 elderly volunteers (M age = 80.22, SD = 9.36) were enrolled. Data were obtained from four load cells and a twin-axis wrist goniometer. Wrist deviation and vertical force were examined when participants used a walker with horizontal handles to assist in standing up and sitting down. Significant wrist angle deviation occurred with the use of a walker, with dorsiflexion of the right hand greater than that of the left. Males exerted significantly greater vertical force. In the sitting position, greater ulnar deviation was seen among experienced walker users, whereas during standing, experienced users exhibited greater dorsiflexion. The horizontal handles of most marketed walkers may cause user wrist deviations, suggesting researchers should pursue improvements in walker design.

Screw Conveyors Power and Throughput Analysis during Horizontal Handling of Paddy Grains

The tests reported in this research were conducted to determine the effects of those parameters believed to have thegreatest influence upon horizontal screw conveyors throughput capacity and power requirement when handlingpaddy grains. Two screw conveyors with diameters of 20 and 25 cm were evaluated at four screw clearances (6, 9,12 and 15 mm) and five screw rotational speeds (200, 300, 400,500 and 600 rpm). The results revealed that forboth the conveyors tested, with increasing the screw rotational speed, the conveyor capacity increased andreached to a maximum point and after the point, the volumetric capacity decreased. Increasing the screw speedcaused the volumetric efficiency and power requirements of the conveyors to be decreased and increased,respectively. The throughput capacity and power requirement of the conveyors increased (P

The Galatian Shield in Egypt

In the Hellenistic world Galatian mercenaries were extremely popular in the armies of the successor kingdoms. They were a non-aligned ethnic mercenary element which would be loyal to its employer, the king, rather than the local community. The Ptolemaic kingdom was no exception, hiring many of these mercenaries and settling them in Egypt. Once the Galatians arrived in Egypt, an effort was made to preserve the uniqueness of these “barbarian” troops among the rest of the population. Nowhere is this distinction clearer than in the symbols used to identify Galatians in art. The most prevalent of these symbols is the shield. With its distinctive boss and horizontal handle, the Celtic shield used by the Galatians has an appearance that conveys an ethnic attachment. Greek and Egyptian shields are smaller with a different boss and handle combination that would have made the distinction clear for a person living in Egypt at the time. In Ptolemaic Egypt the Galatian shield became an identifying symbol of the Galatian mercenaries living in the kingdom, a symbol reinforced by their Greek neighbors.

Rowing Skill Affects Power Loss on a Modified Rowing Ergometer

In rowing, the athlete has to maximize power output and to minimize energy losses to processes unrelated to average shell velocity. The contribution of velocity efficiency (evelocity; the fraction of mechanical power not lost to velocity fluctuations) to rowing performance in relation to the contributions of maximum oxygen uptake (V[spacing dot above]O2max) and gross efficiency (egross) was investigated. Relationships between evelocity and movement execution were determined. Twenty-two well-trained female rowers participated in two testing sessions. In the first session, they performed a 2000-m time trial on a modified rowing ergometer that allowed for power losses due to velocity fluctuations. The V[spacing dot above]O2max, the evelocity, and the amount of rower-induced impulse fluctuations (RIIF) due to horizontal handle and foot stretcher forces were determined in a steady state part of the time trial. RIIF was used as a measure of movement execution. In the second session, egross was determined at submaximal intensity. As expected, V[spacing dot above]O2max accounted for the major part of explained variance in the 2000-m time (53%, P < 0.001). Velocity efficiency accounted for a further 14%, egross for 11% (P < 0.05). Negative correlations were found between evelocity and RIIF values of several discreet intervals within a stroke cycle. The results suggest that optimal timing of forces applied to the ergometer will help minimizing power loss to velocity fluctuations. This study indicates that a relationship exists between performance and evelocity. Furthermore, evelocity appears to be related to movement execution, in particular the timing of handle and foot stretcher forces.

Prehension synergies during nonvertical grasping, I: experimental observations.

The mechanical complexities of rotating an object through the gravity field present a formidable challenge to the human central nervous system (CNS). The current study documents the finger force patterns selected by the CNS when performing one-, two-, and four-finger grasping while holding an object statically at various orientations with respect to vertical. Numerous mechanically "unnecessary" behaviors were observed. These included: nonzero tangential forces for horizontal handle orientations, large internal forces (i.e., those in excess of equilibrium requirements) for all orientations, and safety margins between 50 and 90%. Additionally, none of the investigated measures were constant across orientations or could be represented as a simple trigonometric function of orientation. Nonetheless, all measures varied in systematic (and sometimes symmetric) ways with orientation. The results suggest that the CNS selects force patterns that are based on mechanical principles but also that are not simply related to object orientation. This study is complemented by a second paper that provides an in-depth analysis of the mechanics of nonvertical grasping and accounts for many of the observed results with numerical optimization (see Part II - current issue). Together, the papers demonstrate that the CNS is likely to utilize optimization processes when controlling prehensile actions.

Joint excursion, handle velocity, and applied force: a biomechanical analysis of ergonometric rowing.

Rowers may sacrifice on-water technique during ergonometric training in an attempt to increase stroke output. This cross-sectional study aimed to identify characteristics of ergonometric rowing technique that could be potentially detrimental to an effective and safe on-water performance. Joint excursion, handle velocity, and applied force were measured in 44 athletes while they performed a 2500 meter race on an instrumented ergometer. Results on four subjects are presented here. Their performance is compared to that of a Barcelona Olympic and World champion rower with 12 years of experience to illustrate how athletes deviate from standard on-water technique. Kinematic data showed knee joint oscillations and out-of-phase hip and knee joint reversals. Horizontal handle velocity curves indicated that higher stroke rates were achieved by a decrease in recovery time. Vertical handle velocity curves exhibited bi-directional variations. The largest amplitude occurred at the end of the drive phase during an upward displacement of the handle that was associated with a jerk in the applied force. Force-time curves at different stroke rates showed greater variability in the initial portion of the drive phase. Perpetuation of these technique deviations may be detrimental to on-water performance. Biomechanical analyses may allow coaches to better monitor technique during ergonometric training.

Practical Origami in the Microscale Organic Lab

The construction of a small paper boxlet, ideally suited for handling and drying small amounts of crystals, is presented. Flat horizontal handles present in the boxlet allow one to record pertinent data.

Training in handling: an evaluative study

Training programmes in handling have been one of the most used means of preventing work-related backache. The effectiveness of these programmes has not yet been demonstrated however, since they have rarely been evaluated. The purpose of this study was precisely to assess one of these programmes in the hospital sector which specifically dealt with the handling of patients. A field study was conducted and handling methods used by 32 trained orderlies were characterized using an observational grid developed and validated specifically to describe patient handling operations. The extent to which these orderlies used the handling methods taught was determined, and the observed deviations from these methods were characterized and interpreted. The results show that the handling principles taught (working with a straight back using the legs) were not frequently used in the workplace. Furthermore, the use of training was closely related to the type of handling carried out. In handling operations in which the effort includes a horizontal component (mainly those carried out in bed) the training was hardly used, while in vertical handling operations the taught principles were more frequently used. These results suggest that actual training is not well adapted to the handling of patients, particularly to horizontal handling carried out in the bed. Two main deficiencies in the actual programmes are pointed out. First, it is shown that, for reasons of physical constraints, training could not always be applied; second, the rationale of the taught principles could also be questioned, particularly the emphasis given to the use of the legs.

Poteries grises médiévales produites à Saint-Gilles du Gard

The important documentation about ceramics, obtained from the medieval potiers ovens at Saint-Gilles du Gard, has made it possible to characterize the various productions ofthis workshop, and to set afirst typology. Besides the «pegau », representing the majority, coexist less known new shapes in grey ceramic, in particular, pots with horizontal handles on the side, open shapes and various jugs. This production presents a low-rhodanian aspect, and dates from the end of the XIVth century, as the typologie data and the archaeomagnetic investigation demonstrate. The wide persistence of burning in reducing atmosphere in the Eastern Languedoc in this period, is thus proved. The use of several clay types within the same workshop, suggested by the external observation and proved by the laboratory analysis, tells us how a workshop functioned. Above ail, it incites the archaeologist, who undertakes some investigations about the places oforigin offinished items, to be extremely careful when interpreting the observed groups.