Linking supply network flexibility with mass customization capability

Purpose The importance of supply network flexibility (SNF) in the development of mass customization capability (MCC) has been implied in the literature but seldom subjected to empirical investigation. To fill the gap and contribute to MC literature, this paper aims to examine the role of SNF in facilitating the development of MCC of organizations. Furthermore, it has been investigated whether the use of information and communication technologies (ICTs) strengthens the above relationship. Design/methodology/approach Drawing on the supply chain literature and dynamic capability theory, the study proposes a research framework depicting the interconnectedness among the variables of interest. The proposed framework has been tested using structural equation modelling based on partial least squares by using the data collected from a questionnaire-based survey of a sample of Indian manufacturing organizations. Findings The findings indicate that the dimensions of SNF, namely, sourcing flexibility and supplier flexibility, positively affect the MCC of the organizations and the strength of these relationships is further amplified by the implementation of ICTs. Practical implications The study shows the managerial opportunities for the development of a flexible and competent supply network to facilitate the development or enhancement of MCC. Originality/value This study contributes to scant literature by providing empirical evidence for the relationship between SNF and MCC. Further, this study enriches the understanding of the crucial role of ICT by exploring its moderating effect on the relationship between the variables of interest.

Probing the association between resting state brain network dynamics and psychological resilience

This study aimed at replicating a previously reported negative correlation between node flexibility and psychological resilience, i.e., the ability to retain mental health in the face of stress and adversity. To this end, we used multiband resting-state BOLD fMRI (TR = .675 sec) from 52 participants who had filled out three psychological questionnaires assessing resilience. Time-resolved functional connectivity was calculated by performing a sliding window approach on averaged time series parcellated according to different established atlases. Multilayer modularity detection was performed to track network reconfigurations over time and node flexibility was calculated as the number of times a node changes community assignment. In addition, node promiscuity (the fraction of communities a node participates in) and node degree (as proxy for time-varying connectivity) were calculated to extend previous work. We found no substantial correlations between resilience and node flexibility. We observed a small number of correlations between the two other brain measures and resilience scores, that were however very inconsistently distributed across brain measures, differences in temporal sampling, and parcellation schemes. This heterogeneity calls into question the existence of previously postulated associations between resilience and brain network flexibility and highlights how results may be influenced by specific analysis choices.

Motor Cortical Network Flexibility is Associated With Biomechanical Walking Impairment in Chronic Stroke

Background: The inability to flexibly modulate motor behavior with changes in task demand or environmental context is a pervasive feature of motor impairment and dysfunctional mobility after stroke. Objective: The purpose of this study was to test the reactive and modulatory capacity of lower-limb primary motor cortical (M1) networks using electroencephalography (EEG) measures of cortical activity evoked by transcranial magnetic stimulation (TMS) and to evaluate their associations with clinical and biomechanical measures of walking function in chronic stroke. Methods: TMS assessments of motor cortex excitability were performed during rest and active ipsilateral plantarflexion in chronic stroke and age-matched controls. TMS-evoked motor cortical network interactions were quantified with simultaneous EEG as the post-TMS (0–300 ms) beta (15–30 Hz) coherence between electrodes overlying M1 bilaterally. We compared TMS-evoked coherence between groups during rest and active conditions and tested associations with poststroke motor impairment, paretic propulsive gait deficits, and the presence of paretic leg motor evoked potentials (MEPs). Results: Stroke ( n = 14, 66 ± 9 years, F = 4) showed lower TMS-evoked cortical coherence and activity-dependent modulation compared to controls ( n = 9, 68 ± 6 years, F = 3). Blunted reactivity and atypical modulation of TMS-evoked coherence were associated with lower paretic ankle moments for propulsive force generation during walking and absent paretic MEPs. Conclusions: Impaired flexibility of motor cortical networks to react to TMS and modulate during motor activity is distinctly associated with paretic limb biomechanical walking impairment, and may provide useful insight into the neuromechanistic underpinnings of chronic post-stroke mobility deficits.

Closed-Loop Supply Chain Design with Sustainability Aspects and Network Resilience under Uncertainty: Modelling and Application

In this study, we present a multiobjective mixed-integer nonlinear programming (MINLP) model to design a closed-loop supply chain (CLSC) from production stage to distribution as well as recycling for reproduction. The given network includes production centers, potential points for establishing of distribution centers, retrieval centers, collecting and recycling centers, and the demand points. The presented model seeks to find optimal locations for distribution centers, second-hand product collection centers, and recycling centers under the uncertainty situation alongside the factory’s fixed points. The purpose of the presented model is to minimize overall network costs including processing, establishing, and transportation of products and return flows as well as environmental impacts while maximizing social scales and network flexibility according to the presence of uncertainty parameters in the problem. To solve the proposed model with fuzzy uncertainty, first, the improved epsilon (ε)-constraints approach is used to transform a multiobjective to a single-objective problem. Afterward, the Lagrangian relaxation approach is applied to effectively solve the problem. A real-world case study is used to evaluate the performance of the proposed model. Finally, sensitivity analysis is performed to study the effects of important parameters on the optimal solution.

HS-MOEA/D: An Oriented Algorithm for Delay and Reliability VNF-SC Deployment

Network function virtualization (NFV) technology can realize on-demand distribution of network resources and improve network flexibility. It has become one of the key technologies for next-generation communications. Virtual network function service chain (VNF-SC) deployment is an important problem faced by network function virtualization technology. In this paper, the problem, VNF deployment for VNF-SC, is investigated. First, a two-objective mathematical model, which maximizes balancing and reliability of SFC, is established. In this model, VNFs are divided into two classes, i.e., part of required VNFs in each VNF-SC is dependent, others are independent. Second, harmony search-based MOEA/D (HS-MOEA/D) is proposed to solve the model effectively. In HS-MOEA/D, Chebyshev decomposition mechanism is used to transform multiobjective optimization problem into a series of single-objective optimization subproblems. A new evolutionary strategy is deeply studied in order to propose a new harmony search (HS) algorithm. Finally, to show high performance of the proposed algorithm, a large number of experiments are conducted. The simulation results show that the proposed algorithm enhances the reliability of SFC and reduces the end-to-end delay.

Service Function Chain Placement in Distributed Scenarios: a Systematic Review

The network function virtualization (NFV) paradigm is an emerging technology that provides network flexibility by allowing the allocation of network functions over commodity hardware, like legacy servers in an IT infrastructure. In comparison with traditional network functions, implemented by dedicated hardware, the use of NFV reduces the operating and capital expenses and improves service deployment. In some scenarios, a complete network service can be composed of several functions, following a specific order, known as a service function chain (SFC). SFC placement is a complex task, already proved to be NP-hard. Moreover, in highly distributed scenarios, the network performance can also be impacted by other factors, such as traffic oscillations and high delays. Therefore, a given SFC placement strategy must be carefully developed to meet the network operator service constraints. In this paper, we present a systematic review of SFC placement advances in distributed scenarios. Differently from the current literature, we examine works over the last 10 years which addressed this problem while focusing on distributed scenarios. We then discuss the main scenarios where SFC placement has been deployed, as well as the several techniques used to create the placement strategies. We also present the main goals considered to create SFC placement strategies and highlight the metrics used to evaluate them.

Antecedents of a firm’s supply chain agility: the roles of a transactive memory system and supply network flexibility

Purpose The purpose of this paper is twofold: first, to evaluate the roles of a transactive memory system and the supply network flexibility (SNF) of the firm as antecedents of a firm’s supply chain agility (FSCA), also incorporating the moderating role of the transactive memory system; and, second, to evaluate the relationship between FSCA and operations performance (OP). Design/methodology/approach Four hypothesized relationships are tested with survey data from 190 high-tech firms using structural equation models. Findings FSCA can be enhanced through the transactive memory system and SNF, although a higher degree of transactive memory system weakens the positive relationship between SNF and FSCA. A positive relationship is identified between FSCA and OP, while FSCA mediates the relationship between SNF and OP. Practical implications Managers can increase FSCA and improve OP by developing both the transactive memory system and SNF. Given that firms have limited resources, investment in internal capabilities should be prioritized as this appears to be more effective at developing FSCA. Originality/value The findings expand the literature by exploring two antecedents of FSCA and by analyzing the impact of FSCA on different measures of OP. Few prior studies have highlighted the importance of the transactive memory system to the operations function.

All-optical demultiplexing of closely spaced multimedia radio signals using sub-picometer fiber Bragg grating

Subcarrier multiplexed (SCM) transmission of multimedia radio signals such as CATV (5-860 MHz), cellular wireless (900 MHz) and wireless LAN (2.4 GHz) over fiber is frequently used to deliver broadband services cost effectively. These multi-channel radio-over-fiber (ROF) links have interesting applications and can connect enhanced wireless hotspots that will support high speed wireless LAN services or low speed cellular services to different customers from the same antenna. The SCM signals need to be demultiplexed, preferably in the optical domain for many reasons. Prefiltering of SCM signals with fiber-based optical filters warrants the use of inexpensive photodetectors and increases network flexibility. However, realizing optical demultiplexing as sub-GHz level is challenging and thus necessitates optical filters with high selectivity and low insertion loss and distortion. We developed a novel sub-picometer all-optical bandpass filter by creating a resonance cavity using two closely matched fiber Bragg gratings (FBGs). This filter has a bandwidth of 120 MHz at -3 dB, 360 MHz at -10 dB and 1.5 GHz at -20 dB. Experimental results showed that the filter is capable of separating two radio frequency (RF) signals spaced as close as 50 MHz without significant distortion. When this demultiplexer was employed to optically separate 2.4 GHz and 900 MHz radio signals, it was found to be linear from -38 dBm to +6 dBm with ~ 25.5 dB isolation. There was no significant increment in the BER of the underlying multimedia data. Results verified that the fabricated narrow bandpass filter can be a potential candidate in demultiplexing of RF signals in networks based on subcarrier multiplexed schemes.