Examining the State of Risk Management Research in New Product Development Process

New products are major sources of competitive advantage and success for a manufacturing enterprise. However, not all new product development (NPD) initiatives result in a successful product and are therefore a major cause of wasted resources. Furthermore, NPD processes are becoming increasingly complex and risky due to today’s globalized market and customers’ desire for technologically advanced products. While there has been a significant interest in academia about NPD risks, the existing literature is spread across multiple outlets, making it difficult for any practitioner or researcher to synthesize the current work. This article aims to minimize that gap by providing a comprehensive overview of current research activities in the field of risk management in NPD process in one place. The research design is based on mapping and classification of the existing body of knowledge into the domains of NPD risk analysis and management. The article analyzes the contemporary NPD risk analysis methods on three fronts: risk identification, risk assessment, and risk mitigation. Based on the review, the article then identifies and discusses several key areas for future research significant to engineering management practices. Finally, an integrated framework is presented to provide a holistic approach toward risk management in the NPD process, followed by the practical implications for engineering managers and practitioners.     

Pre-charging of module capacitors of MMC when the module switches are driven by a source derived from the module capacitor

A modular multilevel converter (MMC) is one of the latest multilevel converters used for high and medium-voltage power conversion. It is based on cascade connection of multiple identical modules using IGBTs as switching devices. Module switches of MMC are preferably driven by a source derived from the module capacitor. In each MMC module, the control circuit, consisting of gate drivers, is powered from a dc supply derived from the local capacitor. The module capacitors need to be pre-charged, to power the control circuit. The problem faced while doing so experimentally for MMC with two modules per arm and a solution have been reported earlier. If a fly-back converter is used to generate the power supply for driving the control circuit, the module capacitor voltages become unstable during uncontrolled pre-charging. It has been reported earlier that the reason for this is approximately constant power load on the module capacitor. This work provides theoretical understanding of the problem and shows by analysis that the power supply can be made stable if the load on the module capacitor is made a positive resistance load. As the complexity of MMC with more than two modules per arm is higher, the phenomenon is studied by simulation for MMC with four modules per arm. It shows that when a fly-back converter is used for generating the power supply, similar instability occurs in MMC with four modules per arm. It shows that when the module capacitor is made to have a load with positive resistance characteristics, the module capacitor voltages and consequently the power supplies stabilize even for MMC with four modules per arm. It further shows that even if the load on the module capacitor is negative resistance type, when fly-back converter is used to generate the module power supply, by switching devices in those modules where power supply becomes available first, followed by sorting algorithm, stable power supplies can be developed on all the modules and the capacitors can be fully charged to the desired voltage.     

Interpretation of Association Behavior and Molecular Interactions in Binary Mixtures from Thermoacoustics and Molecular Compression Data

Density and acoustic velocity were measured for binary liquid mixtures of formamide, N-methylacetamide (NMA), dimethylformamide (DMF), and dimethylacetamide (DMA) with acetonitrile at atmospheric pressure and 293.15 K, 298.15 K, 303.15 K, 308.15 K, or 313.15 K over the concentration range 0.12 to 0.97. Models assuming association and nonassociation of the components of the mixtures were used to predict the behavior of the studied liquids, which would typically show weak interactions. The measured properties were fitted to the Redlich–Kister polynomial to estimate the binary coefficients and standard errors. The data were used to study the molecular interactions in the binary mixtures. Furthermore, the McAllister multibody interaction model was used to correlate the properties of the binary liquid mixtures. Testing of the nonassociation and association models for the different systems showed that, compared with the nonassociation model theoretical results, the association model theoretical results were more consistent with the experimental results.     

Experimental investigations into sintering of magnetic abrasive powder for ultrasonic assisted magnetic abrasive finishing process

The importance of magnetic abrasive powder (MAP) in finishing the surface of work materials as a flexible cutting tool in the presence of a magnetic field during the ultrasonic assisted magnetic abrasive finishing (UAMAF) process is quite evident. A sufficiently intense magnetic field provides the desired magnetic force to the iron particles. This holds nonmagnetic abrasive particles firmly and thus makes flexible chains. However, at higher rotational speeds of the magnet due to the requirement of high centripetal force, the chains start flying away from the finishing zone. In the present work, to overcome this deficiency, bonded MAPs were developed using the sintering technique. The effect of various process parameters on the magnetic property (magnetization) of sintered MAPs was investigated. Design of experiments (DoE) was planned as per the L₈ orthogonal array of the Taguchi method, and magnetizations along with M-H curves for all eight different MAPs were measured. Subsequently, analysis of experimental data was carried out using various techniques to optimize the process parameters. It was observed that sintering temperature affects magnetization the most. Scanned microscopy (SEM) and X-ray diffraction (XRD) analysis were also carried out to investigate bonding strength in sintered MAP.     

Flagellar motor-switch binding face of CheY and the biochemical basis of suppression by CheY mutants that compensate for motor-switch defects in Escherichia coli

CheY is a response regulator protein of Escherichia coli that interacts with the flagellar motor-switch complex to modulate flagellar rotation during chemotaxis. The switch complex is composed of three proteins, FliG, FliM, and FliN. Recent biochemical data suggest a direct interaction of CheY with FliM. In order to determine the FliM binding face of CheY, we isolated dominant suppressors of fliM mutations in cheY with limited allele specificity. The protein products of suppressor cheY alleles were purified and assayed for FliM binding. Six out of nine CheY mutants were defective in FliM binding. Suppressor amino acid substitutions were mapped on the crystal structure of CheY showing clustering of reduced binding mutations on a solvent-accessible face of CheY, thus revealing a FliM binding face of CheY. To examine the basis of genetic suppression, we cloned, purified, and tested FliM mutants for CheY binding. Like the wild-type FliM, the mutants were also defective in binding to various CheY suppressor mutants. This was not expected if CheY suppressors were compensatory conformational suppressors. Furthermore, a comparison of flagellar rotation patterns indicated that the cheY suppressors had readjusted the clockwise bias of the fliM strains. However, a chemotaxis assay revealed that the readjustment of the clockwise bias was not sufficient to make cells chemotactic. Although the suppressors did not restore chemotaxis, they did increase swarming on motility plates by a process called "pseudotaxis." Therefore, our genetic selection scheme generated suppressors of pseudotaxis or switch bias adjustment. The binding results suggest that the mechanism for this adjustment is the reduction in binding affinity of activated CheY. Therefore, these suppressors identified the switch-binding surface of CheY by loss-of-function defects rather than gain-of-function compensatory conformational changes.     

A quantitative framework for security assurance evaluation and selection of cloud services: a case study

Due to the high adoption of cloud services, the protection of data and information is critical. Cloud service customers (CSCs) need help to obtain the authoritative assurances required for the cloud services and negotiate the cloud service contract based on the terms and conditions set by cloud service providers (CSPs). Several standards and guidelines are available for assessing cloud security. However, most of these standards and guidelines are complex and time-consuming to select a service or make an informed decision for CSCs. Moreover, the existing methods are insufficient to solve this problem because they are process-oriented, neglect the importance of stakeholder requirements, and lack a comprehensive and rigid analytic method that can aid decision-makers in making the right decisions. In this paper, we developed two evaluation techniques: (i) a quantitative cloud security assurance method to assess the security level of cloud services by measuring the critical security properties and (ii) a novel and rigid categorical analytical method that enables CSPs to identify the major problems in the system and assess how much gain can be achieved by solving each of them. The cloud security assurance method is based on two important metrics: security requirement and vulnerability. It assists CSCs in avoiding severe mistakes and making informed decisions while selecting a cloud service. Moreover, these methods support CSPs in improving the security level of cloud services and meet customer requirements. The proposed methods are validated using different case scenarios on a private cloud platform.

     

MITA Interleaver for Integrated and Iterative IDMA Systems Over Powerline Channel

Recently, the powerline communication (PLC) mechanism has attracted the attention of researchers across the globe since it demonstrates the least bit error rate in comparison to conventional wireless communication, apart from the merit of no extra cost for implementation of wired communication infrastructure. To make signal transfer over PLC system with no hassling, various multiple access schemes inclusive of Orthogonal Frequency Division Multiple Access (OFDMA), Interleave Division Multiple Access (IDMA) etc. have been employed in the defined communication system. In order to facilitate more reliable communication over PLC channel, the OFDMA and IDMA schemes are combined together, termed as integrated IDMA (IIDMA) scheme. All the variant of IDMA Scheme, inbuilt with interleaving mechanism as its heart, accumulates the merits of original IDMA Scheme in addition to the merits of other multiple access scheme duly coupled with it for intended purpose. In the literature, the researchers have evaluated the IDMA and its variant multiple access schemes with various interleavers, however still there remains scope for improvement in the performance of communication systems with induction of appropriate interleaver. In this paper, a novel interleaver named as Multiplicative Interleaving with Tree Algorithm (MITA) has been implemented over OFDM-IDMA systems and evaluated against existing other interleavers in MATLAB environment. The performance result evidently indicates the superiority of the suggested interleaver in terms of Bit Error Rate (BER), memory consumed and computing complexity. Thus MITA interleaver can be implemented for enhanced performance of the communication system.

     

An Intelligent Session Key-Based Hybrid Lightweight Image Encryption Algorithm Using Logistic-Tent Map and Crossover Operator for Internet of Multimedia Things

Due to the increasing demand for IoMT applications in numerous fields such as healthcare, smart city, smart grids, industrial internet, etc. The privacy and security become a major issue in front of various researchers working in this field. This work proposed a lightweight image encryption algorithm based on a logistic-tent map and crossover operator of a genetic algorithm. Various 1-D chaotic maps are discussed in the literature review, but in some cases, hybrid 1-D chaotic maps have higher performance than simple 1-D chaotic maps. So 1-D chaotic map along with a crossover operator is used in this work. Here logistic-tent map and crossover are used to generate the random session key for each image encryption. Also, a crossover operator is used in encryption rounds for increasing confusion and diffusion. Here in this work, for each image encryption, a new intelligent session key is generated. The strength of the proposed image cryptographic scheme is assessed against resistance to the differential attack (UACI and NPCR), statistical attack (histogram analysis, correlation coefficient and information entropy) and sensitivity to the secret key. The extensive experiments of performance and security assessment show that the proposed cryptographic image scheme is secure enough to withstand all potential cryptanalytic attacks.

     

The precision polishing of bismuth silicate and bismuth germanate

A recipe is given for the polishing of precise surfaces oncrystals of bismuth silicate (BSO) and bismuth germanate(BGO). Using this recipe, crystals having surface figure betterthan 1/10 wave, roughness of 20-50 ? rms, and laserquality parallelism (10 arcsec or better) were obtained withabout 1-2 hours effort.     

Energy Efficient Gravitational Search Algorithm and Fuzzy Based Clustering With Hop Count Based Routing For Wireless Sensor Network

In Wireless sensor networks, energy efficiency is the significant attribute to be improved. Clustering is the major technique to enhance energy efficiency. Using this technique, sensor nodes in the network region are grouped as several clusters and cluster head (CH) is chosen for each and every cluster. This CH gathers data packet from the non-CH members inside the cluster and forwards the collected data packet to the base station. However, the CH may drain its energy after a number of transmissions. So, we present the Energy efficient Gravitational search algorithm (GSA) and Fuzzy based clustering with Hop count based routing for WSN in this paper. Initially, CH is selected using Gravitational Search Algorithm (GSA), based on its weight sensor nodes are joined to the CH and thus cluster is formed. Among the selected CHs in the network, supercluster head (SCH) is selected using a fuzzy inference system (FIS). This selected SCH gathers the data packet from all CHs and forwards it to the sink or base station. For transmission, the efficient route is established based on the hop count of the sensor nodes. Simulation results show that the performance of our proposed approach is superior to the existing work in terms of delivery ratio and energy efficiency.