Strategic Asset Seeking and Innovation Performance: The Role of Innovation Capabilities and Host Country Institutions

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Intensification-driven tabu search for the minimum differential dispersion problem

The minimum differential dispersion problem is a NP-hard combinatorial optimization problem with numerous relevant applications. In this paper, we propose an intensification-driven tabu search algorithm for solving this computationally challenging problem by integrating a constrained neighborhood, a solution-based tabu strategy, and an intensified search mechanism to create a search that effectively exploits the elements of intensification and diversification. We demonstrate the competitiveness of the proposed algorithm by presenting improved new best solutions for 127 out of 250 benchmark instances (>50%). We study the search trajectory of the algorithm to shed light on its behavior and investigate the spatial distribution of high-quality solutions in the search space to motivate the design choice of the intensified search mechanism

Solution-based Tabu Search for the Maximum Min-sum Dispersion Problem

The maximum min-sum dispersion problem (Max-Minsum DP) is an important representative of a large class of dispersion problems. Having numerous applications in practice, the NP-hard Max-Minsum DP is however computationally challenging. This paper introduces an effective solution-based tabu search (SBTS) algorithm for solving the Max-Minsum DP approximately. SBTS is characterized by the joint use of hash functions to determine the tabu status of candidate solutions and a parametric constrained swap neighborhood to enhance computational efficiency. Experimental results on 140 benchmark instances commonly used in the literature demonstrate that the proposed algorithm competes favorably with the state-of-the-art algorithms both in terms of solution quality and computational efficiency. In particular, SBTS improves the best-known results for 80 out of the 140 instances, while matching 51 other best-known solutions. We conduct a computational analysis to identify the respective roles of the hash functions and the parametric constrained swap neighborhood

Identification of the white dwarf companion to millisecond pulsar J2317+1439

We report identification of the optical counterpart to the companion of the millisecond pulsar J2317+1439. At the timing position of the pulsar, we find an object with $g=22.96\pm0.05$, $r=22.86\pm0.04$ and $i=22.82\pm0.05$. The magnitudes and colors of the object are consistent with it being a white dwarf. By comparing with white dwarf cooling models, we estimate that it has a mass of $0.39^{+0.13}_{-0.10}$ M$_{\odot}$, an effective temperature of $8077^{+550}_{-470}$ K and a cooling age of $10.9\pm0.3$ Gyr. Combining our results with published constraints on the orbital parameters obtained through pulsar timing, we estimate the pulsar mass to be $3.4^{+1.4}_{-1.1}$ M$_{\odot}$. Although the constraint on the pulsar mass is still weak, there is a significant possibility that the pulsar could be more massive than two solar mass.Comment: 7 pages, 6 figures, accepted for publication in Ap

Molecular cloning, structural analysis and expression of a zinc binding protein in cotton

The full-length zinc-binding protein (ZnBP) gene was cloned from a normalized cDNA library constructed from a cotton mutant (Xiangmian-18) during the gland-forming stage. The clone was sequenced and analysed. BLASTP analysis showed that the deduced amino acid sequence of ZnBP in Xiangmian-18 is similar to that in Arabidopsis thaliana (GenBank accession no. EFH46337.1) with an overall similarity of 77%. The cDNA insert comprises 654 base pairs (bp) and 217 amino acid residues. Its molecular weight is 24.6 kDa, and the theoretical pI is 9.33. The cotton ZnBP gene was cloned from the gDNA from Xiangmian-18 leaves. After sequencing the two fragments, a 1731 bp cotton ZnBP gene with three introns was identified. Using pET-28a(+) as a prokaryotic expression vector, the gene was expressed in Escherichia coli BL21(DE3). The conditions for achieving optimal ZnBP expression were 37°C, IPTG 1 mmol/L, 8 h and a shaker speed of 150 rpm. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis confirmed the correct expression of the protein. pCAMBIA2300-35S-OCS was used as a eukaryotic expression vector. The recombinant plasmid pCAMBIA2300-ZnBP was used to transform competent Agrobacterium GV3101 by the freeze-thaw method. Then, A. thaliana plants were transformed by the floral dipping method. Transformed plants were grown to maturity in a growth chamber. After screening on kanamycin-resistant half-strength Murashige and Skoog plates and polymerase chain reaction (PCR) analysis, two transgenic plant strains were obtained. Northern blot analysis showed that ZnBP expression was higher in homozygous plants than in wild-type plants. The differences between the phenotypes of homozygous and wild-type plants indicate that the ZnBP gene affects the growth and development of A. thaliana. The results of prokaryotic expression of ZnBP and overexpression of the ZnBP gene in A. thaliana improve our understanding of the function of this gene. Future studies should investigate the molecular mechanisms involved in gland morphogenesis in cotton.Key words: Gossypium hirsutum, pigment gland, zinc binding protein, prokaryotic expression, overexpression

Structural influence on atomic hopping and electronic states of Pd-based bulk metallic glasses

Atomic motion and electronic structures of Pd–Ni–Cu–P bulk metallic glasses were investigated using 31P nuclear magnetic resonance. The hopping rate of P atoms was determined by the stimulated echo technique. Significant hopping was observed in all alloys well below the glass transition temperature. Increasing the Cu content to above 25 at. % increases P hopping significantly, consistent with the previous finding that the openness of the structure increases with Cu content. In contrast, P hopping is not influenced by changes of local electronic states at P sites, induced by the substitution of Ni by Cu

A 14-bit 250 MS/s IF Sampling Pipelined ADC in 180 nm CMOS Process

This paper presents a 14-bit 250 MS/s ADC fabricated in a 180 nm CMOS process, which aims at optimizing its linearity, operating speed, and power efficiency. The implemented ADC employs an improved SHA with parasitic optimized bootstrapped switches to achieve high sampling linearity over a wide input frequency range. It also explores a dedicated foreground calibration to correct the capacitor mismatches and the gain error of residue amplifier, where a novel configuration scheme with little cost for analog front-end is developed. Moreover, a partial non-overlapping clock scheme associated with a high-speed reference buffer and fast comparators is proposed to maximize the residue settling time. The implemented ADC is measured under different input frequencies with a sampling rate of 250 MS/s and it consumes 300 mW from a 1.8 V supply. For 30 MHz input, the measured SFDR and SNDR of the ADC is 94.7 dB and 68.5 dB, which can remain over 84.3 dB and 65.4 dB for up to 400 MHz. The measured DNL and INL after calibration are optimized to 0.15 LSB and 1.00 LSB, respectively, while the Walden FOM at Nyquist frequency is 0.57 pJ/step

Strain-induced magnetic phase transition in SrCoO3−δ_{3-\delta} thin films

It has been well established that both in bulk at ambient pressure and for films under modest strains, cubic SrCoO$_{3-\delta}$ ($\delta < 0.2$) is a ferromagnetic metal. Recent theoretical work, however, indicates that a magnetic phase transition to an antiferromagnetic structure could occur under large strain accompanied by a metal-insulator transition. We have observed a strain-induced ferromagnetic to antiferromagnetic phase transition in SrCoO$_{3-\delta}$ films grown on DyScO$_3$ substrates, which provide a large tensile epitaxial strain, as compared to ferromagnetic films under lower tensile strain on SrTiO$_3$ substrates. Magnetometry results demonstrate the existence of antiferromagnetic spin correlations and neutron diffraction experiments provide a direct evidence for a G-type antiferromagnetic structure with Ne\'el temperatures between $T_N \sim 135\,\pm\,10\,K$ and $\sim 325\,\pm\,10\,K$ depending on the oxygen content of the samples. Therefore, our data experimentally confirm the predicted strain-induced magnetic phase transition to an antiferromagnetic state for SrCoO$_{3-\delta}$ thin films under large epitaxial strain.Comment: 6 pages, 4 figure

Probing the lightest new gauge boson BHB_H in the littlest Higgs model via the processes γγ→ffˉBH\gamma\gamma \to f\bar{f}B_H at the ILC

The neutral gauge boson $B_H$ with the mass of hundreds GeV, is the lightest particle predicted by the littlest Higgs(LH) model, and such particle should be the first signal of the LH model at the planed ILC if it exists indeed. In this paper, we study some processes of the $B_H$ production associated with the fermion pair at the ILC, i.e., $\gamma\gamma\to f\bar{f}B_{H}$. The studies show that the most promising processes to detect $B_H$ among $\gamma\gamma\to f\bar{f}B_{H}$ are $\gamma\gamma\to l'^+l'^-B_{H}(l'=e,\mu)$, and they can produce the sufficient signals in most parameter space preferred by the electroweak precision data at the ILC. On the other hand, the signal produced via the certain $B_H$ decay modes is typical and such signal can be easily identified from the SM background. Therefore, $B_H$, the lightest gauge boson in the LH model would be detectable at the photon collider realized at the ILC.Comment: 12 pages, 4 figure