Serial Mechanism Research Articles

The impact of value co-creation orientation on radical service innovation: Exploring a serial mediation mechanism

By integrating the dynamic capability perspective and service-dominant logic (SDL), this study empirically investigates the distinct roles of internal and external knowledge integration capabilities in the relationship between value co-creation orientation and radical service innovation. Based on survey data from a sample of 200 service innovation projects from IT and Internet-related industries in China, this study uses structural equation modeling (SEM) and a bootstrapping approach to test the hypothesized relationships in the conceptual model. The results show that external knowledge integration capability mediates the relationship between value co-creation orientation and radical service innovation. In addition, internal and external knowledge integration capability jointly play a serial mediating role between value co-creation orientation and radical service innovation. These findings contribute to the growing literature on value co-creation in radical service innovation, and offer service managers meaningful implications that reveal how to convert multiple sources of knowledge resources into superior radical service innovation.

RACS2: a framework of a remote autonomous control system for telescope observation and its application

With the increasing demand for astronomical observations, telescope systems are becoming increasingly complex. Thus, the observatory control software needs to be more intelligent. It has to control each instrument inside the observatory, finish the observational tasks autonomously, and report the information to users if needed. We developed a distributed autonomous observatory control framework named the Remote Autonomous Control System 2nd (RACS2) to meet these requirements. Rich features are integrated into the RACS2 framework. The RACS2 is a modular framework, in which each device control software and system services are implemented as different components. Furthermore, the RACS2 framework assimilates new techniques, such as a lightweight message and serialization mechanism. RACS2 also has good compatibility with other frameworks or ecosystems such as Python and the EPICS (Experimental Physics and Industrial Control System). The RACS2 framework can communicate with EPICS-based and Python-based software. With the help of these features, key system components like executor, scheduler are developed. The executor component can support sophisticated tasks. Autonomous observation can be achieved by the scheduler component. A set of web-based graphical user interface (GUI) is designed to help control and manage the framework remotely. Based on the RACS2 framework, we have implemented the Dome A Twins (DATs) telescope’s observation system and the space object observation system. The systems have been operated for more than 1 year. The RACS2 framework also has been used in our other projects like camera control system of Wide Field Survey Telescope (WFST) and its observatory control system, and the design can be a useful reference for the development of other frameworks.

The effect of robot anthropomorphism on revisit intentions after service failure: a moderated serial mediation model

PurposeThe purpose of this study is to examine how robotic anthropomorphism and personalized design may affect consumers' reactions to brands after service failure.Design/methodology/approachThis study conducted two studies based on cognitive appraisal theory and artificial intelligence device acceptance theory. Study 1 explored the mechanisms by which the type of anthropomorphic design of the service robot (humanoid robot/nonhumanoid robot) influenced revisit intention after service failure through a one-factor between-subjects design based on a restaurant dining scenario. Study 2 was based on a hotel check-in scenario and explored the moderating effect of robot personalization design on the above mechanisms through a 2 (anthropomorphic design: humanoid robot/nonhumanoid robot) × 2 (personalized design: self-name/no name) between-subjects design.FindingsStudy 1 shows that consumers have higher performance expectations for nonhumanoid robots, leading to a higher tolerance for service failure, which in turn generates higher revisit intentions. Study 2 shows that consumers' performance expectations are significantly enhanced after custom naming of humanoid robots, so the serial mediation mechanism for the effect of robot anthropomorphic design on revisit intention does not hold.Originality/valueThis study extends the research of artificial intelligence device acceptance theory in the field of service failure and exploratively proposes an intervention mechanism for the negative effects of the anthropomorphic design of service robots.

Human vs. machine-like representation in chatbot mental health counseling: the serial mediation of psychological distance and trust on compliance intention.

This study examined a serial mediation mechanism to test the effect of chatbots' human representation on the intention to comply with health recommendations through psychological distance and trust towards the chatbot counselor. The sample of the study comprised 385 adults from the USA. Two artificial intelligence chatbots either with human or machine-like representation were developed. Participants had a short conversation with either of the chatbots to simulate an online mental health counseling session and reported their experience in an online survey. The results showed that participants in the human representation condition reported a higher intention to comply with chatbot-generated mental health recommendations than those in the machine-like representation condition. Furthermore, the results supported that both psychological distance and perceived trust towards the chatbot mediated the relationship between human representation and compliance intention, respectively. The serial mediation through psychological distance and trust in the relationship between human representation and compliance intention was also supported. These findings provide practical guidance for healthcare chatbot developers and theoretical implications for human-computer interaction research.

Stiffness Modeling and Deformation Analysis of Parallel Manipulators Based on the Principal Axes Decomposition of Compliance Matrices

Abstract This paper presents a general equivalent approach to solve the stiffness modeling or load-deformation problem of non-redundant parallel mechanisms. Based on the principal axes decomposition of structure compliance matrices, an equivalent six-degrees-of-freedom (6-DOFs) serial mechanism is established to approximate the load-deformation behavior of each flexible link in the mechanism. Hence, each limb of the parallel mechanism can be equivalent to a serial redundant rigid body mechanism with passive elastic joints, and the load-deformation problem can be transformed to the equilibrium configuration calculation of the equivalent mechanism. The main advantage of the proposed method is that the robotic kinematics and statics, rather than the elastic mechanics, can be directly adopted to solve the equilibrium configuration of the parallel mechanism under external load. Besides, a closed form solution of the corresponding deformation can be obtained, which can be solved by the gradient-based searching algorithm. Therefore, the final deformation will no longer be linear to the external load, which makes this method more accurate and more suitable for the deformation prediction and compensation in real industrial working conditions. In order to verify the effectiveness and correctness of this method, a 3PRRU parallel manipulator will be introduced as an example, to compare the load-deformation results with the finite element analysis (FEA) simulation and matrix calculation methods, so the nonlinearity feature can be shown in an intuitive manner.

Compliant manipulator design method (COMAD) for the type synthesis of all serial and parallel multi-DoF compliant mechanisms, with example of a Schönflies motion generator

This article presents the compliant manipulator design method (COMAD) for the synthesis of serial and parallel multi-DoF compliant mechanisms. Currently, the freedom and constraint topology (FACT)-method results in flexure systems being a serial kinematic solution for multi-DoF motions. In the COMAD method parallel solutions are included too through 3 steps: (1) obtaining the serial and parallel kinematic solutions for an intended set of end-effector DoFs with the type synthesis of legs-method; (2) transforming each legtype into a flexure leg by using the FACT method; (3) combining legs in parallel to obtain complete compliant mechanism designs. It was applied for a compliant Schönflies motion generator – having three translations and one rotation – resulting in 5 different 4-DoF flexure legs. 4 designs were new compared to the result obtained using the FACT method. Then, a set of legs was combined in parallel resulting in a compliant Schönflies mechanism, which was manufactured. Its mobility was experimentally evaluated by modal analysis. The intended motions separately became visible during its first four eigenmodes. They are the mechanism’s DoFs as their stiffness is relatively low.

Kinegami: Algorithmic Design of Compliant Kinematic Chains From Tubular Origami

Origami processes can generate both rigid and compliant structures from the same homogeneous sheet material. In this article, we advance the origami robotics literature by showing that it is possible to construct an arbitrary rigid kinematic chain with prescribed joint compliance from a single tubular sheet. Our “Kinegami” algorithm converts a Denavit–Hartenberg specification into a single-sheet crease pattern for an equivalent serial robot mechanism by composing origami modules from a catalogue. The algorithm arises from the key observation that tubular origami linkage design reduces to a Dubins path planning problem. The automatically generated structural connections and movable joints that realize the specified design can also be endowed with independent user-specified compliance. We apply the Kinegami algorithm to a number of common robot mechanisms and hand-fold their algorithmically generated single-sheet crease patterns into functioning kinematic chains. We believe this is the first completely automated end-to-end system for converting an abstract manipulator specification into a physically realizable origami design that requires no additional human input.

Axiomatic characterizations of the constrained probabilistic serial mechanism

Afacan (Games and Economic Behavior 110: 71-89, 2018) introduces an object allocation with random priorities problem. He proposes the constrained probabilistic serial (CPS) mechanism. This study, for the first time in the literature, provides axiomatic characterizations of CPS. The first result characterizes it via non-wastefulness, claimwise stability, constrained ordinal fairness, and surplus invariance to truncations. The other axiomatizes CPS via constrained stochastic efficiency, claimwise stability, and constrained ordinal fairness. The independence of the axioms is provided.

Ocean Wave Active Compensation Analysis for Redundant Hybrid Boarding System: A Multi-Task Motion Planning Method

In this paper, to effectively solve the joint motion planning of a nine-DOF redundant hybrid boarding system in the process of ocean wave active compensation, we present a multi-task motion planning (MTMP) method for the redundant hybrid boarding system. First, the hybrid mechanism is disassembled into a six-DOF parallel mechanism and a three-DOF serial mechanism for kinematic analysis separately to obtain the Jacobian matrix of the hybrid mechanism in the task space. Then, according to the configuration characteristics of the hybrid mechanism and to avoid the defects of the pseudo-inverse and weighted pseudo-inverse methods in motion planning, several secondary tasks are proposed to constrain the motion planning of the hybrid mechanism. Based on simulations and comparisons, the results show that the MTMP method solves the problems of joint limitation, reverse compensation, overlap compensation, and divergence with time in the motion planning of the pseudo-inverse method and the weighted pseudo-inverse method. Meanwhile, the MTMP method has more superiority in the joint margin and compensation space range.

A Simple Characterization of Assignment Mechanisms on Set Constraints

We consider the problem of allocating divisible/indivisible goods to agents according to agents’ ordinal preferences. Hashimoto et al. [15] provided a nonalgorithmic and axiomatic characterization of well-studied probabilistic serial (PS) mechanism. Recently, Fujishige et al. [12] generalized the PS mechanism where goods are enlarged from a fixed set to a family of sets which is a polytope defined by a system of linear inequalities associated with submodular functions. The above extended PS (EPS) greatly improved the flexibility of allocations. Based on these two results, in this paper, we investigate the nonalgorithmic and axiomatic characterization of EPS. We show that the EPS rule is the only mechanism satisfying the ordinal fairness and a newly defined non-wastefulness. The submodularity plays a crucial role in our arguments.

Improvements in the anaerobic digestion of biological sludge from pulp and paper mills using thermal pretreatment.

The current disposal of biosludge generated in wastewater treatment has high costs and causes environmental problems, anaerobic digestion (AD) of solid waste is a promising alternative. Thermal hydrolysis (TH) is an accepted technology to enhance anaerobic biodegradability of sewage sludge, but this technology has not been developed to be used with biological sludge from industrial wastewater treatment. In this work, the improvements to the AD of biological sludge from cellulose industry when thermal pretreatment is carried out were experimentally determined. The experimental conditions for TH were 140 °C and 165 °C for 45 minutes. Batch tests were carried out to quantify methane production evaluated as biomethane potential (BMP), anaerobic biodegradability according to volatile solids (VS) consumption and kinetic adjustments. An innovative kinetic model based on the serial mechanism of fast and slow biodegradation fractions was tested for untreated waste, and parallel mechanism was also evaluated. Increases in BMP and biodegradability values according to VS consumption were determined with increasing TH temperature. The results of 241 NmL CH4 gVS substrate-1 for BMP and 65% biodegradability are reported for the 165 °C treatment. AD rate increased for the TH waste compared to the untreated biosludge. Improvements of up to 159% for BMP and 260% for biodegradability according to VS consumption were quantified for TH biosludge compared to untreated biosludge.

Kinematics Analysis of 6-Degrees-of-Freedom Parallel + Serial Type Hybrid Mechanisms Containing Parallel Mechanism With High Coupling Motions

AbstractThe existing displacement of parallel + serial type hybrid mechanisms is mainly solved by the equivalent serial mechanism (SM) method. However, a large number of lower mobility parallel mechanisms (PMs) that have high coupled motions at the end-effector cannot be equivalent to SMs. Thus, the displacement problem especially for the inverse displacement of this type of hybrid mechanisms has not been well solved. On the basis of this situation, this article takes a 6-degrees-of-freedom (DOFs) 3-UPU + 3R hybrid mechanism as an example to give a general method to solve the displacement problem. First, based on the inverse displacement and pose coupling relationship of the 3-UPU PM, its forward displacement is solved by Sylvester’s dialytic elimination method, and then the forward displacement of the 3-UPU + 3R hybrid mechanism is obtained by the superposition method. Second, by skillfully dealing with the relationship between coupling motions of the 3-UPU PM and the motion of hybrid mechanism, three nonlinear equations containing three unknown motion parameters are obtained, and the inverse displacement problem is solved using Sylvester’s dialytic elimination. The research in this article is valuable in the kinematics modeling of hybrid mechanisms.

High-performance work systems and future time perspective mediation through two lenses courage and well-being: testing a serial mediation mechanism

PurposeUpon the premises of social exchange theory (SET), this study aimed at hypothesizing and examining a serial mediation model that investigated the underlying mechanism through which a high-performance work system (HPWS) affects individuals’ future time perspective (FTP).Design/methodology/approachThe hypothesized relationships were examined using responses collected from 275 employees from 15 local private banks and 40 established branches through a proportionate stratified sampling technique. The statistical package for social sciences (SPSS) PROCESS macro 3.0 and analysis of moment’s structure (AMOS) 24.0 were employed for data analysis purposes.FindingsThe study revealed that HPWS is indirectly related to the individuals’ FTP through workplace social courage (WSC) and employee well-being (EWB) sequentially. Prescriptions for theoretical and managerial implications were discussed, and future research viewpoints with limitations were acknowledged.Originality/valueThis study illuminated the underlying mechanism and theoretical logic linking HPWS and individuals’ FTP by proposing the serial mediating effect of WSC and EWB.

DSTAGCN: Dynamic Spatial-Temporal Adjacent Graph Convolutional Network for Traffic Forecasting

Capturing complex and dynamic spatial-temporal dependencies of traffic data is of great importance for accurate and real-time traffic forecasting in intelligent transportation systems. The spatial-temporal dependency between traffic locations is often dynamic, which means the correlation between the traffic status of different locations changes jointly over their spatial distance and the time slice they are in. Most of the existing Graph Convolutional Network-based methods usually capture spatial and temporal dependencies separately and then combine them in a parallel or serial mechanism to capture the spatial-temporal features. They always utilize the predefined static graph structure to capture both local correlations and global dependencies in the same time slice. These methods are incapable of directly learning dynamic spatial-temporal dependency across time slices. Meanwhile, it is challenging to learn the spatiotemporal correlation knowledge among traffic locations only by using neural networks. To address these issues, we propose a novel Dynamic Spatial-Temporal Adjacent Graph Convolutional Network (DSTAGCN), which connects the latest time slice with each past time slice to construct the spatial-temporal graph. DSTAGCN can directly learn the global spatial dependency across time and simultaneously capture the spatial-temporal dependencies through graph convolution. Since fuzzy theory make it possible to represent uncertain relationships, a simplified fuzzy neural network that integrates fuzzy systems and neural networks is designed to help generating the graph adjacency matrix representing the dynamic adjacency correlations. Experiments on public datasets show that our method outperforms baselines with fast convergence.

A Monte Carlo tree search-based method for decision making of generator serial restoration sequence

Reasonable generator serial restoration sequence is a key issue to the system restoration following blackouts. This paper proposed an optimization method for the decision making of generator serial restoration sequence based on Monte Carlo tree search algorithm. First, the generator serial restoration sequence mechanism during the restoration process is analyzed. Considering the maximization of the total power generation capacity as the objective function, this paper also consider generator’s hot start. Second, the Monte Carlo tree search algorithm (MCTS) is applied to decide the generator serial restoration sequence. In the simulation stage of MCTS, the Dijkstra’s algorithm is utilized to determine the shortest path between the selected generator and the recovered power system. Finally, the IEEE 39 bus system and Hebei power grid system are used to validate the proposed algorithm. Simulation results show that the proposed method is efficiency and it can provide an reasonable generator serial restoration sequence to maximizing power generation during the restoration process.

Costly information acquisition in centralized matching markets

When applying to a university, students and their parents devote considerable time acquiring information about university programs in order to form preferences. We explore ways to reduce wasteful information acquisition, that is, to help students avoid acquiring information about out‐of‐reach schools or universities, using a market design approach. Focusing on markets where students are ranked by universities based on exam scores, we find that, both theoretically and experimentally, a sequential serial dictatorship mechanism leads to higher student welfare than a direct serial dictatorship mechanism. This is because the sequential mechanism informs students about which universities are willing to admit them, thereby directing their search. Our experiments also show that the sequential mechanism has behavioral advantages because subjects deviate from the optimal search strategy less frequently than under the direct mechanism. Furthermore, providing historical cutoff scores under the direct mechanism can increase student welfare, especially when the information costs are high, although the observed effect is weaker than that of a sequential mechanism.

A Multimodal Aggregation Network With Serial Self-Attention Mechanism for Micro-Video Multi-Label Classification

Currently, micro-videos have attracted increasing attention due to their unique properties and great commercial value. Considering that micro-videos naturally incorporate multimodal information, a powerful representation method for distinct joint multimodal representations is essential for real applications. Inspired by the potential of attention neural network architectures over various tasks, we propose a multimodal aggregation network (MANET) with a serial self-attention mechanism to perform tasks of micro-video multi-label classification. Specifically, we first propose a parallel content-dependent graph neural networks (CDGNN) module, which explores category-related embeddings of micro-videos by disentangling category relations into modality-specific and modality-shared category dependency patterns. Then we introduce a serial self-attention (SSA) module to transmit the multimodal information in sequential order, in which an aggregation bottleneck is incorporated to better collect and condense the significant information. Experiments conducted on a large-scale multi-label micro-video dataset demonstrate that our proposed method has achieved competitive results compared with several state-of-the-art methods.

Kinematic Calibration of a 6-DoF Parallel Manipulator With Random and Less Measurements

Parallel manipulator (PM) embraces more kinematic errors than serial mechanism. The substantial errors in PM usually demand more measurements, which leads to low efficiency and affects the accuracy of identification due to the ill-conditioning problem. Having realized this common problem in the kinematic calibration of PMs, we carried out a finite and instantaneous screw (FIS)-based kinematic calibration on a 6- <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</u> UHU PM before application to fracture reduction. <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</u> , U, and H denote actuated revolute joint, universal joint, and helical joint, respectively. The error model is built by the error mapping of serial chains in the FIS framework. Instead of devoting to the measurement planning for more precise identification, the identifiability of kinematic errors is thoroughly analyzed. Redundant errors are categorized as the ones within limb and among limbs. A minimal identification model is thus defined and an error conversion method is proposed for compensation. Calibration experiments show that the FIS method has an improved accuracy of the 6- <underline xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</u> UHU PM at least one magnitude higher than the precision demand, i.e., mean position and orientation errors 0.0574 mm and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5.1197\,\,{\times }\,\, 10^{-4}$ </tex-math></inline-formula> rad after calibration. Compared with the conventional closed-loop vector (CLV) equation method, the accuracy improvement of FIS method is higher. In addition, comparisons with the commonly used configuration selection methods indicate that our method allows random and a smaller number of measurements and can reach satisfactory accuracy.

A Survey of Transoral Robotic Mechanisms: Distal Dexterity, Variable Stiffness, and Triangulation.

Robot-assisted technologies are being investigated to overcome the limitations of the current solutions for transoral surgeries, which suffer from constrained insertion ports, lengthy and indirect passageways, and narrow anatomical structures. This paper reviews distal dexterity mechanisms, variable stiffness mechanisms, and triangulation mechanisms, which are closely related to the specific technical challenges of transoral robotic surgery (TORS). According to the structure features in moving and orienting end effectors, the distal dexterity designs can be classified into 4 categories: serial mechanism, continuum mechanism, parallel mechanism, and hybrid mechanism. To ensure adequate adaptability, conformability, and safety, surgical robots must have high flexibility, which can be achieved by varying the stiffness. Variable stiffness (VS) mechanisms based on their working principles in TORS include phase-transition-based VS mechanism, jamming-based VS mechanism, and structure-based VS mechanism. Triangulations aim to obtain enough workspace and create adequate traction and counter traction for various operations, including visualization, retraction, dissection, and suturing, with independently controllable manipulators. The merits and demerits of these designs are discussed to provide a reference for developing new surgical robotic systems (SRSs) capable of overcoming the limitations of existing systems and addressing challenges imposed by TORS procedures.

A Novel Two-Degree-of-Freedom Gimbal for Dynamic Laser Weeding: Design, Analysis, and Experimentation

Current robotic laser weeding systems mostly rely on serial mechanisms with one or two actuated axes, which can barely meet the requirements of high precision and dynamic performances. In this article, a novel laser weeding gimbal is proposed based on a two-degree-of-freedom 5-revolute rotational parallel manipulator to perform a dynamic intrarow laser weeding operation. Comprehensive analyses consisting of kinematics, workspace, singularity, and dynamics are carried out to evaluate the performance of the proposed design. Finally, experimental tests were conducted both in lab and field environments and the results are provided, in which the positioning accuracy has been evaluated as in average errors of 0.62 mm in position at the distance of 535 mm, and the dynamic weeding efficiency is around 0.72 s/weed with a dwell time of 0.64 s at the tracking speed of 0.1 m/s. The effectiveness of the proposed dynamic intrarow weeding mechanism has been evaluated in a real field trial.