bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystal structure of 1-{4-hydroxy-3-[(pyrrolidin-1-yl)methyl]phenyl}-3-phenylprop-2-en-1-one
Authors: Aydın Abdullah , Akkurt Mehmet , Gul Halise Inci , Yerdelen Kadir Ozden , Celik Raziye Catak
Published: April 2016

In the title compound, C20H21NO2, the pyrrolidine ring adopts an envelope conformation with the N atom at the flap position. The central benzene ring makes dihedral angles of 21.39 (10) and 80.10 (15)° with the phenyl ring and the mean plane of the pyrrolidine ring, respectively. The molecular conformation is stabilized by an intramolecular O—H...N hydrogen bond, which closes anS(6) ring. A weak C—H...π interaction is observed in the crystal.
Crystal structure of Brinzolamide: a carbonic anhydrase inhibitor
Authors: Zheng Huirong , Lou Benyong
Published: April 2016

In crystal structure of the title compound, C12H21N3O5S3[systematic name: (R)-4-ethylamino-2-(3-methoxypropyl)-3,4-dihydro-2H-thieno[3,2-e][1,2]thiazine-6-sulfonamide 1,1-dioxide], there exist three kinds of hydrogen-bonding interactions. The sulfonamide group is involved in hydrogen bonding with the secondary amine and the methoxy O atom, resulting in the formation of layers parallel to thebcplane. The layers are linked by an N—H...O hydrogen bond involving a sulfonamide O atom as acceptor and the secondary amine H atom as donor, which gives rise to the formation of a unique bilayer structure. The absolute structure of the molecule in the crystal was determined by resonant scattering [Flack parameter = 0.01 (4)].
Crystal structure of (1S,3R,8R,10S)-2,2-dichloro-10-hydroxy-3,7,7,10-tetramethyltricyclo[6.4.0.01,3]dodecan-9-one
Authors: Benzalim Ahmed , Auhmani Aziz , Ait Itto My Youssef , Daran Jean-Claude , Abdelwahed Auhmani
Published: April 2016

The asymmetric unit of the title compound, C16H24Cl2O2, contains two independent molecules (AandB) which are built from three fused rings,viz.a seven-membered heptane ring, a six-membered cyclohexyl ring bearing a ketone and an alcohol group, and a cyclopropane ring bearing two Cl atoms. In the crystal, the two molecules are linkedviatwo O—H...O hydrogen bonds, forming anA–Bdimer with anR22(10) ring motif. TheAmolecules of these dimers are linkedviaa C—H...O hydrogen bond, forming chains propagating along thea-axis direction. Both molecules have the same absolute configuration,i.e.1S,3R,8R,10S, which is based on the synthetic pathway and further confirmed by resonant scattering [Flack parameter = 0.03 (5)].
Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-6-fluorophenyl)-1-(3-fluoro-4-methoxyphenyl)prop-2-en-1-one
Authors: Hassan Nur Hafiq Hanif , Abdullah Amzar Ahlami , Arshad Suhana , Khalib Nuridayanti Che , Razak Ibrahim Abdul
Published: April 2016

In the title chalcone derivative, C16H11ClF2O2, the enone group adopts anEconformation. The dihedral angle between the benzene rings is 0.47 (9)° and an intramolecular C—H...F hydrogen bond closes anS(6) ring. In the crystal, molecules are linked into a three-dimensional network by C—H...O hydrogen bonds and aromatic π–π stacking interactions are also observed [centroid–centroid separation = 3.5629 (18) Å]. The intermolecular interactions in the crystal structure were quantified and analysed using Hirshfeld surface analysis.
Crystal structure and spectroscopic analysis of a new oxalate-bridged MnIIcompound:catena-poly[guanidinium [[aquachloridomanganese(II)]-μ2-oxalato-κ4O1,O2:O1′,O2′] monohydrate]
Authors: Sehimi Hiba , Chérif Ichraf , Zid Mohamed Faouzi
Published: April 2016

As part of our studies on the synthesis and the characterization of oxalate-bridged compoundsM–ox–M(ox = oxalate dianion andM= transition metal ion), we report the crystal structure of a new oxalate-bridged MnIIphase, {(CH6N3)[Mn(C2O4)Cl(H2O)]·H2O}n. In the compound, a succession of MnIIions (situated on inversion centers) adopting a distorted octahedral coordination and bridged by oxalate ligands forms parallel zigzag chains running along thecaxis. These chains are interconnected through O—H...O hydrogen-bonding interactions to form anionic layers parallel to (010). Individual layers are held togetherviastrong hydrogen bonds involving the guanidinium cations (N—H...O and N—H...Cl) and the disordered non-coordinating water molecule (O—H...O and O—H...Cl), as well as by guanidinium π–π stacking. The structural data were confirmed by IR and UV–Visible spectroscopic analysis.
Synthesis, FT–IR characterization and crystal structure of aqua(5,10,15,20-tetraphenylporphyrinato-κ4N)manganese(III) trifluoromethanesulfonate
Authors: Harhouri Wafa , Mchiri Chadlia , Najmudin Shabir , Bonifácio Cecilia , Nasri Habib
Published: April 2016

In the title salt, [Mn(C44H28N4)(H2O)](CF3SO3) or [MnIII(TPP)(H2O)](CF3SO3) (where TPP is the dianion of 5,10,15,20-tetraphenylporphyrin), the MnIIIcation is chelated by the four pyrrole N atoms of the porphyrinate anion and additionally coordinated by an aqua ligand in an apical site, completing the distorted square-pyramidal coordination environment. The average Mn—N(pyrrole) bond length is 1.998 (9) Å and the Mn—O(aqua) bond length is 2.1057 (15) Å. The central MnIIIion is displaced by 0.1575 (5) Å from the N4C20mean plane of the porphyrinate anion towards the apical aqua ligand. The porphyrinate macrocycle exhibits a moderate ruffling and strong saddle deformations. In the crystal lattice, the [MnIII(TPP)(H2O)]+cation and the trifluoromethanesulfonate counter-ions are arranged in alternating planes packed along [001]. The components are linked together through O—H...O hydrogen bonds and much weaker C—H...O and C—H...F interactions. The crystal packing is further stabilized by weak C—H...π interactions involving the pyrrole and phenyl rings of the porphyrin moieties.
Transmission electron microscopy for the evaluation and optimization of crystal growth
Authors: Stevenson Hilary P. , Lin Guowu , Barnes Christopher O. , Sutkeviciute Ieva , Krzysiak Troy , Weiss Simon C. , Reynolds Shelley , Wu Ying , Nagarajan Veeranagu , Makhov Alexander M. , Lawrence Robert , Lamm Emily , Clark Lisa , Gardella Timothy J. , Hogue Brenda G. , Ogata Craig M. , Ahn Jinwoo , Gronenborn Angela M. , Conway James F. , Vilardaga Jean-Pierre , Cohen Aina E. , Calero Guillermo
Published: April 2016

The crystallization of protein samples remains the most significant challenge in structure determination by X-ray crystallography. Here, the effectiveness of transmission electron microscopy (TEM) analysis to aid in the crystallization of biological macromolecules is demonstrated. It was found that the presence of well ordered lattices with higher order Bragg spots, revealed by Fourier analysis of TEM images, is a good predictor of diffraction-quality crystals. Moreover, the use of TEM allowed (i) comparison of lattice quality among crystals from different conditions in crystallization screens; (ii) the detection of crystal pathologies that could contribute to poor X-ray diffraction, including crystal lattice defects, anisotropic diffraction and crystal contamination by heavy protein aggregates and nanocrystal nuclei; (iii) the qualitative estimation of crystal solvent content to explore the effect of lattice dehydration on diffraction and (iv) the selection of high-quality crystal fragments for microseeding experiments to generate reproducibly larger sized crystals. Applications to X-ray free-electron laser (XFEL) and micro-electron diffraction (microED) experiments are also discussed.
Using iterative fragment assembly and progressive sequence truncation to facilitate phasing and crystal structure determination of distantly related proteins
Authors: Wang Yan , Virtanen Jouko , Xue Zhidong , Tesmer John J. G. , Zhang Yang
Published: April 2016

Molecular replacement (MR) often requires templates with high homology to solve the phase problem in X-ray crystallography.I-TASSER-MRhas been developed to test whether the success rate for structure determination of distant-homology proteins could be improved by a combination of iterative fragmental structure-assembly simulations with progressive sequence truncation designed to trim regions with high variation. The pipeline was tested on two independent protein sets consisting of 61 proteins from CASP8 and 100 high-resolution proteins from the PDB. After excluding homologous templates,I-TASSERgenerated full-length models with an average TM-score of 0.773, which is 12% higher than the best threading templates. Using these as search models,I-TASSER-MRfound correct MR solutions for 95 of 161 targets as judged by having a TFZ of >8 or with the final structure closer to the native than the initial search models. The success rate was 16% higher than when using the best threading templates.I-TASSER-MRwas also applied to 14 protein targets from structure genomics centers. Seven of these were successfully solved byI-TASSER-MR. These results confirm that advanced structure assembly and progressive structural editing can significantly improve the success rate of MR for targets with distant homology to proteins of known structure.
A generic protocol for protein crystal dehydration using the HC1b humidity controller
Authors: Lobley Carina M. C. , Sandy James , Sanchez-Weatherby Juan , Mazzorana Marco , Krojer Tobias , Nowak Radosław P. , Sorensen Thomas L.
Published: April 2016

Dehydration may change the crystal lattice and affect the mosaicity, resolution and quality of X-ray diffraction data. A dehydrating environment can be generated around a crystal in several ways with various degrees of precision and complexity. This study uses a high-precision crystal humidifier/dehumidifier to provide an airstream of known relative humidity in which the crystals are mounted: a precise yet hassle-free approach to altering crystal hydration. A protocol is introduced to assess the impact of crystal dehydration systematically applied to nine experimental crystal systems. In one case, that of glucose isomerase, dehydration triggering a change of space group fromI222 toP21212 was observed. This observation is supported by an extended study of the behaviour of the glucose isomerase crystal structure during crystal dehydration.
Discovery of a novel allosteric inhibitor-binding site in ERK5: comparison with the canonical kinase hinge ATP-binding site
Authors: Chen Hongming , Tucker Julie , Wang Xiaotao , Gavine Paul R. , Phillips Chris , Augustin Martin A. , Schreiner Patrick , Steinbacher Stefan , Preston Marian , Ogg Derek
Published: April 2016

MAP kinases act as an integration point for multiple biochemical signals and are involved in a wide variety of cellular processes such as proliferation, differentiation, regulation of transcription and development. As a member of the MAP kinase family, ERK5 (MAPK7) is involved in the downstream signalling pathways of various cell-surface receptors, including receptor tyrosine kinases and G protein-coupled receptors. In the current study, five structures of the ERK5 kinase domain co-crystallized with ERK5 inhibitors are reported. Interestingly, three of the compounds bind at a novel allosteric binding site in ERK5, while the other two bind at the typical ATP-binding site. Binding of inhibitors at the allosteric site is accompanied by displacement of the P-loop into the ATP-binding site and is shown to be ATP-competitive in an enzymatic assay of ERK5 kinase activity. Kinase selectivity data show that the most potent allosteric inhibitor exhibits superior kinase selectivity compared with the two inhibitors that bind at the canonical ATP-binding site. An analysis of these structures and comparison with both a previously published ERK5–inhibitor complex structure (PDB entry 4b99) and the structures of three other kinases (CDK2, ITK and MEK) in complex with allosteric inhibitors are presented.
Structural insights into chaperone-activity enhancement by a K354E mutation in tomato acidic leucine aminopeptidase
Authors: DuPrez Kevin T. , Scranton Melissa A. , Walling Linda L. , Fan Li
Published: April 2016

Tomato plants express acidic leucine aminopeptidase (LAP-A) in response to various environmental stressors. LAP-A not only functions as a peptidase for diverse peptide substrates, but also displays chaperone activity. A K354E mutation has been shown to abolish the peptidase activity but to enhance the chaperone activity of LAP-A. To better understand this moonlighting function of LAP-A, the crystal structure of the K354E mutant was determined at 2.15 Å resolution. The structure reveals that the K354E mutation destabilizes an active-site loop and causes significant rearrangement of active-site residues, leading to loss of the catalytic metal-ion coordination required for the peptidase activity. Although the mutant was crystallized in the same hexameric form as wild-type LAP-A, gel-filtration chromatography revealed an apparent shift from the hexamer to lower-order oligomers for the K354E mutant, showing a mixture of monomers to trimers in solution. In addition, surface-probing assays indicated that the K354E mutant has more accessible hydrophobic areas than wild-type LAP-A. Consistently, computational thermodynamic estimations of the interfaces between LAP-A monomers suggest that increased exposure of hydrophobic surfaces occurs upon hexamer breakdown. These results suggest that the K354E mutation disrupts the active-site loop, which also contributes to the hexameric assembly, and destabilizes the hexamers, resulting in much greater hydrophobic areas accessible for efficient chaperone activity than in the wild-type LAP-A.
3-Phenoxymethyl-6-phenyl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole
Authors: Mohamed Shaaban K. , Mague Joel T. , Akkurt Mehmet , Bakhite Etify A. , Albayati Mustafa R.
Published: April 2016

In the title compound, C16H12N4OS, the bicyclic triazolothiadiazole core is approximately planar, with an r.m.s. deviation of 0.018 Å. The phenyl rings are inclined to its mean plane by 7.66 (7) and 71.79 (7)°. In the crystal, molecules are linkedviaa C—H...π interaction and a π–π interaction [intercentroid distance = 3.2942 (9) Å] involving inversion-related triazole rings. These interactions result in the formation of chains propagating along [10-1].
N′-Benzylidene-2-({5-[(4-chlorophenoxy)methyl]-4-phenyl-4H-1,2,4-triazol-3-yl}sulfanyl)acetohydrazide hemihydrate
Authors: Mague Joel T. , Mohamed Shaaban K. , Akkurt Mehmet , Bakhite Etify A. , Albayati Mustafa R.
Published: April 2016

The title compound, C24H20ClN5O2S·0.5H2O, has three independent molecules in the asymmetric unit and two water molecules of crystallization, one of which is equally disordered over two sites. The three unique organic molecules differ in the conformations of the substituents on the pyrazole ring. In the crystal, extensive O—H...O, O—H...N, N—H...O and C—H...O hydrogen bonding generates a three-dimensional network and C—H...π interactions are also observed.
N′-[(E)-2-Hydroxybenzylidene]-2-(6-methoxynaphthalen-2-yl)propanohydrazide: a redetermination
Authors: Mohamed Shaaban K. , Mague Joel T. , Akkurt Mehmet , Mohamed Alaa F. , Albayati Mustafa R.
Published: April 2016

The structure of the title compound, C21H20N2O3, was originally determined at ambient temperature [Wuet al.(2007).Inorg. Chim. Acta,360, 3069–3074]. In this determination, with data collected at 150 K, the asymmetric unit comprises two independent molecules (1 and 2) that differ considerably in their conformations. In particular, the methyl group at the mid-point of molecule 2 is disordered over two sites. This was modelled with restraints so that the geometries of the two components are comparable and the disorder components refined to an occupancy ratio of 0.750 (6):0.250 (6). Intramolecular O—H...N and intermolecular N—H...O hydrogen bonds stabilize the structure with significant additional input from C—H...π interactions.
An anti-windup control strategy to actuator saturating input voltage for active magnetic bearing system
Authors: Pati Avadh , Negi Richa
Published: April 2016

Purpose

The active magnetic bearing is highly nonlinear and unstable system. In general most of physical systems, conventional PID control strategies are employed for their stable operation but the dynamics of the system are influenced by input voltage saturation that degrades the performance of the system. The conventional PID control scheme does not work properly alone. In such a situation, PID faces windup phenomenon that leads to instability in the system. To overcome this problem, an anti-windup control scheme leads to stable and smooth operation of active magnetic bearing system.

Design/methodology/approach

The proposed anti-windup control strategy is based on dynamic output feedback that is applied on linearized active magnetic bearing (AMB) system to stabilize and avoid the input voltage saturation effect in the actuator.

Findings

An anti-windup controller is designed for active magnetic bearing system in presence of input voltage saturation. The stability of AMB system with anti-windup controller is derived in sense of Lyapunov and expressed as linear matrix inequality problem for AMB system and the designed anti-windup controller also enlarges the region of attraction of considered AMB system.

Originality/value

T-S fuzzy technique is used for obtaining local linear model of nonlinear active magnetic bearing system for easy and simple implementation of anti-windup control scheme. In proposed methodology the region of attraction for anti-windup compensator is also discussed. The effectiveness of proposed method is verified by the numerical simulation results for considered active magnetic bearing system and domain of attraction or stability region of closed loop AMB system are also calculated using Eigen Value Optimization technique for both the cases such as with and without anti-windup controller. The comparative result and the contribution of proposed control strategy are also discussed.
A polynomial approach to determine the time-dependent electric and magnetic fields in anisotropic materials by symbolic computations
Authors: Yakhno Valery George , Altunkaynak Meltem
Published: April 2016

Purpose

The purpose of this paper is to calculate the time-dependent electric and magnetic fields in anisotropic media with a general structure of anisotropy by symbolic computations.

Design/methodology/approach

An analytical approach for the computation of the time-dependent electric and magnetic fields is suggested. This approach consists of the following. Input data, electric and magnetic fields are presented in polynomial form.The exact formulae for electric and magnetic fields are computed by symbolic transformations in Maple.

Findings

The time-dependent second order partial differential equations for the electric and magnetic fields with polynomial data were obtained from Maxwell's equations when the current density is presented in a polynomial form with respect to space variables in a bounded region of three dimensional space. The exact solutions of obtained equations were computed symbolically using Maple.

Originality/value

The obtained polynomial solutions do not contain errors if data are polynomials. We have shown that these solutions are approximate solutions with good accuracy for data which are approximated by polynomials in a bounded region of 3D space.
Low power modular redundancy: a power efficient fault tolerant approach for digital circuits
Authors: Ansari M. Saeed , Mahani Ali , Mohammadi Karim
Published: April 2016

Purpose

To increase protection level against transient faults, circuit designers usually take advantage of redundant structures like Triple Modular Redundancy (TMR). Since redundancy compel a significant power overhead, proposing a low power fault tolerant technique in digital circuits is the main objective of this research work.

Design/methodology/approach

In order to moderate power consumption, we use a dual to triple modular redundancy. In fact, we put one of the modules in a TMR system in sleep mode while the other two operating modules are producing the same outputs. Once a mismatch is detected, the third one exits the sleep mode and the dual modular redundancy (DMR) approach turns into a conventional TMR. Also a novel stoppable clock generator is proposed to handle the sleep mode of the third module. Finally, a new three-input majority voter, compatible with our proposed technique, is presented.

Findings

Power analysis of combinational circuit benchmarks, ISCAS85, and ISCAS89 as sequential circuit benchmarks are depicted. Simulation results show the power reduction of up to 30% in comparison with the conventional modular redundancy approach.

Originality/value

Since modular redundancy is the most effective and the most well-known fault tolerant approach which is widely used in reliable circuits designs, it is important to reduce its power consumption. In this paper configuring the sleep mode operation of a circuit and stoppable clock generator lead to a new TMR technique in which the power consumption is strongly reduced.
Power analysis approach and its application to IP-based SoC design
Authors: Durrani Yaseer Arafat , Riesgo Teresa , Khan Muhammad Imran , Mahmood Tariq
Published: April 2016

Purpose

Low-power consumption has become an important issue that cannot be ignored in System-on-Chip (SoC) design. The key challenge encountered by system design is how to maintain balance between the estimation accuracy and speed. This paper aims at demonstrating an accurate and fast power estimation technique.

Design/methodology/approach

The methodology adopted in the paper is to use input patterns with the predefined statistical characteristics which helps to analyze the average power consumption of the different intellectual-property (IP) cores and the interconnects/buses in SoC design. Similarly the paper has implemented Genetic algorithm (GA) to generate sequences of input signals during the power estimation procedure.

Findings

The GA concurrently optimizes the input signal characteristics that influence the final solution of the pattern. In addition to that, a Monte-Carlo zero-delay simulation is also performed for individual IP core and bus at high-level. By the simple addition of these cores/buses, power is predicted by a novel macro-model function. In experiments, the average error is estimated at 13.84%.

Research limitations/implications

To present the research findings with clarity and to avoid complexities, the paper does not consider delay factors like glitches, jitter etc. in the power model.

Practical implications

The proposed methodology allowed accurate power/energy analysis of practical applications mapped onto Network-on-Chip (NoC) based Multiprocessors SoC platform. It enables the performance analysis of different design alternatives under the load imposed by complex applications.

Originality/value

This paper is an original contribution and the results demonstrate that our novel technique could be implemented to achieve fast and accurate power estimation in the early stage of any SoC design.
Implementation of sensorless IPMSM drive using the stator current space vector orientation reference frame
Authors: Najjar-Khodabakhsh Abbas , Soltani Jafar
Published: April 2016

Purpose

In this paper an adaptive nonlinear control scheme has been proposed for direct torque and flux control of interior permanent magnet synchronous motor (IPMSM) without using mechanical sensor.

Design/methodology/approach

In this control method the stator resistance is online estimated by adaptive input-output state feedback linearization (AIOFL) controller. Based on proposed control scheme, the strategies of the maximum torque per ampere (MTPA) and maximum power factor (MPF) have been tested using a so-called stator flux search method.

Findings

The motor equations are transferred from the stationary reference frame to the (SX-SY) two-axis frame of the current by the stator current angle. In this frame, the Y component of the motor current is set to zero and the implementation of the nonlinear controller is independent of the two-axis inductances, the rotor magnetic flux, and position.

Practical implications

The effectiveness and capability of the proposed control method has been verified by simulation and experimental results. The proposed control scheme can be used for the sensorless control of IPMSM drive in industrial applications such as electric vehicle, traction system, and air conditioner.

Originality/value

The proposed controller is developed in a special axis (X-Y) rotating reference frame with the X-axis in coincide with the machine current space vector so that there is no need to use and know the machine inductances and rotor position.
Power flow optimization in a microgrid with two kinds of energy storage
Authors: Rigo-Mariani Remy , Roccuzzo Vincenzo , Sareni Bruno , Maurizio Repetto , Robaum Xavier
Published: April 2016

Purpose

The paper presents the optimization of the power flows inside a microgrid with renewable sources and two kinds of storage. The considered microgrid consists in commercial buildings with maximum daily peak value of 50 kW, photovoltaic arrays with total capacity of 175 kW, a 50 kW/50 kWh high speed flywheel storage and a 50 kW/50 kWh set of Li-ion accumulators.

Design/methodology/approach

The power flows in the microgrid are optimized the day ahead at one hour discretization in order to minimize the electric bill. Several scheduling strategies are proposed for solving the corresponding optimization problem including standard deterministic methods, stochastic algorithms and hybrid heuristics.

Findings

All scheduling strategies investigated in the paper are compared with regard to their accuracy and computational time.

Originality/value

Beyond the comparison of different algorithms devoted to the power flow optimization problem, our approach also addresses the integration of battery ageing in the scheduling strategy.
Analytical frequency modeling of a diode rectifier: formulation for SQP solving versus formulation for Newton-Raphson solving
Authors: Tran Le Nhat Hoang , Gerbaud Laurent , Retiere Nicolas , Nguyen Huu H.
Published: April 2016

Purpose

Static converters generate current harmonics in grids. Numerous studies on analytical frequency models of converters are often required to carry out their harmonic modeling in the context of sizing by optimization. Some formulations are proposed to solve such models. Each formulation has its own advantages and drawbacks. The paper mainly focuses on two formulations: the first to be solved by Sequential Quadratic Programming (SQP) and the second to be solved by Newton-Raphson (NR). In this way, the paper presents the performances of each formulation and compares the results of both formulations for the modeling of a single-phase diode rectifier.

Design/methodology/approach

The paper aims to compare SQP formulation and NR formulation, and to propose the ways to improve their convergence. In the modeling, by using an explicit formulation of the state variables combined to a numerical method, equations are defined to reduce, as far as possible, the number of unknowns.

Findings

The difficulty is to find the good operating mode of the static converter. So, outside the equations and the constraints, the paper proposes to use the eigenvalues of the state space matrixes to initialize the duration of every configuration and to consider the operating symmetries of the static converter that allow to reduce the research area and also the variables calculated.

Research limitations/implications

The number of the conducting phase per half period is a priori, as the operating mode.

Originality/value

The modeling is based on the use of linear components, ideal switches and the static converter operates in steady-state. The main difficulties are to formulate the equations representing the non-controlled switching of semiconductors, and to solve them.
Enhancing the employability of IT graduates in Vietnam
Authors: Thang Phan Vo Minh , Wongsurawat Winai
Published: April 2016

Purpose

– The purpose of this paper is to identify the key determinants of employability of information technology (IT) graduates in Vietnam and examines their impact on self-perceived employability and the duration of the job search.

Design/methodology/approach

– This study is based on data collected from the responses to an online survey from more than 500 IT graduates from different higher education institutions in Vietnam. Employability, its outcome and its key determinants were integrated into one model. Exploratory factor, confirmatory factor and path analyses were conducted to test the model by means of structural equation modeling.

Findings

– The self-perceived employability of IT graduates in Vietnam was determined by graduates’ English language skills, soft skills, adaptability skills, the quality of the institution’s IT program and job seeking efforts. Results also indicated that work experience, professional competencies and employability made the job search duration shorter, but job seeking efforts made job search duration longer.

Research limitations/implications

– Only determinants from individual and institutional aspects were considered, and the sample was also limited to one profession in one country.

Practical implications

– Results can inform students and educators about the improvable areas of employability enhancement.

Originality/value

– This study fills a gap in the employability research by providing a quantitative explanation about relationships among the employability, the job search duration and their key predictors from different aspects.
Graduates’ perceptions of competencies and preparation for labour market transition
Authors: Monteiro Sílvia , Almeida Leandro , Aracil Adela Garcia
Published: April 2016

Purpose

– The purpose of this paper is to explore the influence of work experience and gender on graduates’ perception of competencies, preparation and expectations of success in labour market (LM) transition. The research questions that guide this study are: How do graduates evaluate the competencies acquired during their masters’ degree? How do graduates evaluate their preparation for transition to the LM and their expectations of success?

Design/methodology/approach

– Within the framework of employability models, the authors explore the perception of competencies developed during higher education (HE). Given previous reported effects of gender and work experience on the process of work transition, these two variables are also considered. A questionnaire was administered to 411 students in their final masters’ degree year. Descriptive and inferential statistics, namely, univariate analysis of variance (F-anova 2×3) withpost-hocmultiple comparison test (post-hocHSD of Tukey), are developed to analyse the data and address the research questions.

Findings

– The main results show that there are no significant group differences concerning perception of the development of competencies; the effect of work experience on perceptions related to preparation for transition to the LM depends on gender; and expectations of successful transition to the LM are related to gender, with no significant influence of prior work experience.

Originality/value

– These data suggest that, in developing their programmes, it is important for HE institutions to consider self-beliefs related to students’ diversity, in order to maximize the development and effective use of competencies and individual resources in work contexts, for all students. Exploration of the effect of gender and work experience on perceptions of competencies and preparation for the LM should help HE institutions define curricular programmes and support graduates in preparing for entry to the LM.
From cultural intelligence to supply chain performance
Authors: Tuan Luu Trong
Published: April 2016

Purpose

– Cultural intelligence (CQ) has transcended its role of adaptation to local values toward narrowing the cultural gap between foreign stakeholders and local stakeholders in the supply chain. The purpose of this paper is to decipher the catalyzing role of CQ in its chain effect, through corporate social responsibility and trust, to supply chain performance and competitive intelligence (CI).

Design/methodology/approach

– The proof for the research model was derived from the SEM-based analysis of cross-sectional data provided by 392 respondents from MNCs in Vietnamese business landscape.

Findings

– Findings, from this inquiry, produce the evidence for the positive effect of all four dimensions of CQ (metacognitive, cognitive, motivational, and behavioral CQ) on ethical and legal CSR, as well as knowledge-based and identity-based trust, which leverage supply chain performance. The connectivity between supply chain performance and CI was also established.

Originality/value

– Supply chain literature, from this research model, has increased its breadth with the novel role of CQ and stakeholder-oriented levers such as CSR in heightening supply chain performance.
Logistics activities in supply chain business process
Authors: Marchesini Márcia Maria Penteado , Alcântara Rosane Lúcia Chicarelli
Published: April 2016

Purpose

– The purpose of this paper is to propose a set of logistics activities for each key supply chain business process of the Global Supply Chain Forum (GSCF) model and a conceptual framework to guide their implementation.

Design/methodology/approach

– A literature review on supply chain management (SCM) and logistics was conducted to integrate the existing knowledge of SCM, key business processes, and logistics; the latter is critical element for the success of SCM. A set of logistics activities and a conceptual framework are presented to guide their implementation in each of the key business process of the GSCF model. Three case studies were conducted in Brazilian food companies to verify the applicability of the proposed logistics activities, their characterization, and the conceptual framework.

Findings

– The logistics activities, the key business processes, and the steps to their implementation are integrated into a comprehensive framework. A total of 24 logistics activities and a conceptual framework to guide their implementation for each key business process of the GSCF model were proposed focussing on competitive advantage in a supply chain environment.

Originality/value

– The need for and the benefits derived from the involvement of the logistics in the key business processes of SCM have been reported in the literature, but the logistics activities in these processes and the way they were implemented have not yet been identified. According to Eisenhardt and Graebner (2007), building theory from case studies is an increasingly popular and relevant research strategy that involves using one or more cases to create theoretical constructs, propositions, and/or midrange theory from case-based empirical evidence. Therefore, the research gap to be filled with this manuscript is: “How does the involvement of the logistics area in the key business processes of the GSCF model occur?” The research question of the present study is: “Which activities are performed by the logistics area in the key business processes of the GSCF model and how to implement them?”. This study bridged the research gap and answered the research question by creating a theoretical construct through a conceptual framework to guide the implementation of the logistics activities for each key business process of the GSCF model. This paper aimed to extend the existing theory since the available literature has yet not addressed this research question at all.
Energy-constrained and low-carbon scenarios for the transportation and logistics industry
Authors: von der Gracht Heiko A. , Darkow Inga-Lena
Published: April 2016

Purpose

– There is consensus among experts that the design of future supply chains will have to focus more strongly on environmental concerns. Sustainability will play a major role within the business and has an impact especially on the distant future. Thus, supply chain executives are challenged in designing sustainable supply chains for the future. The paper aims to discuss this issue.

Design/methodology/approach

– The authors develop expert-based scenarios, which describe how future supply chains could evolve by 2030. The authors focus on the transportation and logistics industry’s perspective to provide an industry-internal view. The data collection is based on an internet-based Delphi survey. Overall, 48 top executives from 20 countries, representing academic, governmental, and industrial perspectives, participated in the survey.

Findings

– The authors operationalized the research question into five concrete sub-topics relevant for investigation: energy and emissions, consumer behaviour, future transport modes, design of future supply chains, and innovation. The authors derive five Delphi-based scenarios defined by clusters of their impact and expected probability: measurement and control of CO2-emissions; integrated low energy logistics systems; business-as-usual logistics; no-frills logistics and alternative fuels. Each cluster contributes differently to supply chain strategy.

Originality/value

– The authors address the major issues and challenges experts expect regarding future supply chains in an energy-constrained, low-carbon world. Five scenario clusters evolved for supply chain strategy development. Finally, the authors make recommendations towards strategic planning in the transportation and logistics industry.
Are firms paying more for performance?
Authors: Forth John , Bryson Alex , Stokes Lucy
Published: April 2016

Purpose

– The purpose of this paper is to investigate changes in the economic importance of performance-related-pay (PRP) in Britain through the 2000s using firm-level data.

Design/methodology/approach

– The authors utilise nationally representative, monthly data on the total wage bill and employment of around 8,500 firms. Using these data, the authors decompose the share of the total economy-wide wage bill accounted for by bonuses into the shares of employment in the PRP and non-PRP sectors, the ratio of base pay between the two sectors, and the gearing of bonus payments to base pay within the PRP sector.

Findings

– The growth in the economic importance of bonuses in Britain in the mid-2000s – and subsequent fluctuations since the onset of recession in 2008 – can be almost entirely explained by changes in the gearing of bonus to base pay within the PRP sector. There has been no substantial change in the percentage of employment accounted for by PRP firms; if anything it has fallen over time. Furthermore, movements in the gearing of bonuses to base pay in the economy are heavily influenced by changes in Finance: a sector which accounts for a large proportion of all bonus payments in Britain.

Research limitations/implications

– The paper demonstrates the importance of understanding further how firms decide the size of bonus payments in a given period.

Originality/value

– This is the first paper to present monthly firm-level data for Britain on the incidence and size of bonus payments in the 2000s.
The impact of overeducated and undereducated workers on establishment-level productivity
Authors: Grunau Philipp
Published: April 2016

Purpose

– Many contributions to the educational mismatch literature address the productivity effects of both excess and deficit educational attainments for workers at the individual level. Due to the limited transferability of their results to establishment-level performance, especially when allowing for the possibility of spillover effects from mismatched workers to their well-matched colleagues, from an employer’s point of view, it is highly important to know the net effect of educationally mismatched employees on productivity at the establishment level. The paper aims to discuss these issues.

Design/methodology/approach

– This paper analyses the impact of overeducated and undereducated workers among an establishment’s workforce on its productivity, providing first representative evidence for Germany. Using linked employer-employee data from Germany, the author estimates dynamic panel production functions using a system GMM estimator.

Findings

– The author finds that undereducated workers among an establishment’s workforce impair its (establishment-level) productivity, implying that an establishment’s HR management should avoid the recruitment of undereducated workers, at least if they follow a short-term personnel policy. The effect for overeducated employees is also negative, albeit small and insignificant.

Originality/value

– The consideration of the phenomena of over and undereducation from the employer’s point of view provides further insight into the consequences of educational mismatch.
Cognitive presence in virtual collaborative learning
Authors: Beckmann Jennifer , Weber Peter
Published: April 2016

Purpose

The purpose of this study is to introduce a virtual collaborative learning setting called “Net Economy”, which we established as part of an international learning network of currently six universities, and present our approach to continuously improve the course in each cycle.

Design/methodology/approach

Using the community of inquiry framework as guidance and canonical action research (CAR) as the chosen research design, the discussion forum of the online course is assessed regarding its critical thinking value. We thereby measure critical thinking with the help of the according model provided by Newman et al. (1995), which differentiates 40 indicators of critical thinking from 10 different categories.

Findings

The calculated critical thinking ratios for the analyzed two discussion threads indicate a strong use of outside knowledge, intensive justification and critical assessment of posts by the students. But at the same time, there are also weak spots, like manifold repetitions. Based on these results, we derive changes for the next course cycle to improve the critical thinking of the students.

Originality/value

A comparison of the results after the next course cycle will then allow us to assess the effects of the implemented changes, which would not be possible without a critical thinking diagnosis approach.
Do group affiliated firms specialize in debt? Evidence from Pakistan
Authors: Malik Qamar Uz Zaman , Afza Talat
Published: April 2016

Purpose

– The purpose of this paper is to examine the debt structure of group affiliated firms in Pakistan for the period of 2009-2011. The study seeks to know the level of debt specialization in group affiliated firms. If they do; then how are they different from stand-alone firms?

Design/methodology/approach

– The study primarily uses Herfindahl-Hirschman Index and Excl90 as measures of debt specialization, which are further used in cluster, threshold and conditional analysis. Corporate groups are characterized to subsidize their affiliates through internal debt market and loan guarantee. Logistic regression model is used to analyze association among the measures of debt specialization and firm-specific characteristics for group affiliated and stand-alone firms.

Findings

– The results show that about 85 percent firms use more than 50 percent of debt from one debt type. However, group affiliated firms are more inclined toward debt specialization than stand-alone firms. Tangibility and book leverage are negatively and significantly associated to the measures of debt specialization. Moreover, internal debt market and loan guarantee are suggestive reasons of debt specialization in group affiliated firms.

Practical implications

– This study highlights the issue of group affiliation and its significance on firm’s debt structure. It has implications for determination of the optimal financing strategy. In the context of emerging economies, group affiliated firms can create market imperfections as a protection shield. In case of emerging markets, it is recommended to strengthen regulatory mechanism to avoid such market imperfections.

Originality/value

– Prior studies have explored the phenomenon of debt specialization for rated and unrated firms. However, firm group affiliation is widely studied in the context of capital structure. This is a pioneer study to establish and analyze a link between firm group affiliation and debt specialization.
Board governance, intellectual capital and firm performance
Authors: Nkundabanyanga Stephen Korutaro
Published: April 2016

Purpose

– The purpose of this paper is to examine the relationship between the combined (multiplicative) effect of board governance and intellectual capital (IC) on firm performance.

Design/methodology/approach

– This study is cross-sectional and follows a positivist view of testing pre-specified hypotheses. The study uses a respondent sample of 128 service firms operating in Kampala, directors or managers are the unit of enquiry. Structural equation modelling with analysis of moment structures is used for statistical modelling.

Findings

– Board governance and IC make significant contributions to firm performance. However, their interaction is a significant booster to services sector firms’ performance in Uganda.

Research limitations/implications

– Although an attempt is made at controlling for common method variance in particular by proactive instrument design and testing, and usage of the Harman single factor analytical technique, its influence may not have been dealt away completely owing to failure to obtain a plausible common marker variable. Well, it is meaningful to identify the significant positive multiplicative effects of board governance and IC so as uncover what is needed in service firms to improve their performance.

Originality/value

– Studies explaining firm performance via board governance only and which ignored the synergistic effects of board governance and IC have often missed the reality that the performance of the firm can significantly be improved by means of leveraging IC while simultaneously calling for effective board governance.
FDI and economic growth: empirical evidence from Pakistan
Authors: Rehman Naqeeb Ur
Published: April 2016

Purpose

– The purpose of this paper is to investigate the relationship between FDI and economic growth. Two models have been used to analyse the time series data on Pakistan from 1970 to 2012. This paper contributes to the existing literature by examining the different empirical methods to estimate the relationship between FDI and economic growth. The vector error correction model (VECM) results suggest that FDI depends on the economic growth but this relationship is not true vice versa. The second model showed that FDI, human capital and exports are important factors of economic growth. However, the negative relationship between interactive variables (FDI and human capital) and economic growth indicates that low level of human capital affect the economic growth of Pakistan.

Design/methodology/approach

– Used time series data (1970-2012) for empirical analysis.

Findings

– The VECM results suggest that FDI depends on the economic growth but this relationship is not true vice versa. The second model showed that FDI, human capital and exports are important factors of economic growth. However, the negative relationship between interactive variables (FDI and human capital) and economic growth indicates that low level of human capital affect the economic growth of Pakistan.

Research limitations/implications

– The limitations of this empirical paper are as follows: it would be better to use secondary school enrolment (per cent) to measure human capital instead adult literacy rate. Similarly, the non-availability of R
&
D data on Pakistan limited the scope of the paper to measure the role of absorptive capacity of domestic and its relationship with FDI. The results of this paper are specifically related to Pakistan and cannot be generalized to other countries.

Practical implications

– This empirical study implies that Pakistan should improve its economic growth. The robust policies are required to increase the literacy rate of the country. Higher human capital will attract more FDI into the economy and may reduce the unemployment. This would increase the national output of the country and their national income level. Presently, Pakistan is going through war on terror and foreign firms are reluctant to invest. A stable and secure business environment will ultimately inject foreign direct investment into Pakistan.

Originality/value

– This paper is first time analyse the time series data to explore the relationship between FDI and economic growth. A new approach has been used called VECM.