8,044 research outputs found

    Conditions for Generic Initial Ideals to be Almost Reverse Lexicographic

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    Let II be a homogeneous Artinian ideal in a polynomial ring R=k[x1,...,xn]R=k[x_1,...,x_n] over a field kk of characteristic 0. We study an equivalent condition for the generic initial ideal \gin(I) with respect to reverse lexicographic order to be almost reverse lexicographic. As a result, we show that Moreno-Socias conjecture implies Fr\"{o}berg conjecture. And for the case \Codim I \le 3, we show that R/IR/I has the strong Lefschetz property if and only if \gin(I) is almost reverse lexicographic. Finally for a monomial complete intersection Artinian ideal I=(x1d1,...,xndn)I=(x_1^{d_1},...,x_n^{d_n}), we prove that \gin(I) is almost reverse lexicographic if di>j=1i1dji+1d_i > \sum_{j=1}^{i-1} d_j - i + 1 for each i4i \ge 4. Using this, we give a positive partial answer to Moreno-Socias conjecture, and to Fr\"{o}berg conjecture.Comment: 10 page

    Exploration of New Ternary Gallides and Investigation of Their Structure-Property Relationships

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    This dissertation focuses on the investigation of new ternary intermetallic gallides, which may exhibit exotic physical properties such as heavy-fermion behavior, large magnetoresistance, and even superconductivity. In particular, the Ln-Cu-Ga (Ln = lanthanides) system has been systematically investigated by changing a reaction ratio and/or using a different temperature profile to optimize desired phases. Single crystals of Ln2MGa12 (Ln = La, Ce; M = Ni, Cu) have been synthesized using Ga flux and compared to their Pd analogues. Interestingly, Ce2MGa12 (M = Ni, Cu) show enhanced Sommerfeld coefficient of ¡Ö 191 mJmol-1K-2 and ¡Ö 69 mJmol-1K-2 for Ni and Cu compounds, respectively. Three different structure types such as Ln(Cu,Ga)13 (Ln = La¨CNd, Eu), SmCu4Ga8, and Ln(Cu,Ga)12 (Ln = Y, Gd¨CEr, Yb) have been synthesized by increasing Cu concentration. A large positive magnetoresistance up to 154 % at a field of 9 T is observed for Pr(Cu,Ga)13. Most interestingly, Pr(Cu,Ga)13 shows T2 temperature-dependent resistivity and satisfies Kadowaki-Woods relation, which is indicative of heavy-fermion behavior. The ordered SmCu4Ga8 grown by flux method has been compared to its isostructural disordered analogue, SmCu4.1Ga6.9. Ln(Cu,Ga)12 (Ln = Gd¨CEr) compounds order antiferromagnetically at 12.5 K, 13.5 K, 6.7 K, and 3.4 K for Gd-, Tb-, Dy-, and Er-analogues, respectively. Ln4MGa12 (Ln = Dy¨CEr; M = Pd, Pt) have been grown from Ga flux. Magnetic measurements show that Dy4PdGa12 and Er4PdGa12 are antiferromagnetic with transitions at TN = 10 K and 5.2 K, respectively, while Ho4PdGa12 does not show any magnetic ordering down to 2 K. Ln4PtGa12 (Ln = Dy¨CEr) order antiferromagnetically at TN = 9.8 K, 3.6 K and 5.1 K for Dy-, Ho-, and Er-analogues, respectively. The electrical resistivity data show metallic behavior. Large positive magnetoresistance is shown up to 900 % at 3 K and 9 T for the Ho4PtGa12 analogue. Single crystals of LnAgyX4-y (Ln = La, Ce; X = Al, Ga; y ¡Ö 0.72) have been synthesized by aluminum or gallium flux. These compounds show an occupational disorder for Ag sites. CeAg0.72Al3.28 and CeAg0.67Ga3.33 are metallic, and magnetic measurements indicate that both order ferromagnetically near 3 K

    Distinctive-attribute Extraction for Image Captioning

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    Image captioning, an open research issue, has been evolved with the progress of deep neural networks. Convolutional neural networks (CNNs) and recurrent neural networks (RNNs) are employed to compute image features and generate natural language descriptions in the research. In previous works, a caption involving semantic description can be generated by applying additional information into the RNNs. In this approach, we propose a distinctive-attribute extraction (DaE) which explicitly encourages significant meanings to generate an accurate caption describing the overall meaning of the image with their unique situation. Specifically, the captions of training images are analyzed by term frequency-inverse document frequency (TF-IDF), and the analyzed semantic information is trained to extract distinctive-attributes for inferring captions. The proposed scheme is evaluated on a challenge data, and it improves an objective performance while describing images in more detail.Comment: 14 main pages, 4 supplementary page

    Blue Ocean Strategy vs. Competitive Strategy: The Effect of Business Strategic Choices on Firm Performance, According to the Industry Life Cycle

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    The purpose of this study is to explore how blue ocean strategy and competitive strategy influence a firm\u27s business performance differently according to its stage in the industry life cycle (ILC). We developed a theoretical research model and the measure items to capture the different attributes of the blue ocean and competitive paradigms. We collected primary data from 309 business owners and senior managers working in the U.S. through a survey research. We tested the data by performing the exploratory factor analysis (EFA), the confirmatory factor analysis (CFA) and the structural equation modeling analysis (SEM) using SPSS and AMOS. The results from the statistical analysis demonstrate that the effects of blue ocean strategy on a firm\u27s business performance become increasingly weak as ILC stages pass, while the effects of competitive strategy gradually strengthen. However, our results show that, in general, blue ocean strategy has a more positive effect on a firm\u27s performance than competitive strategy. In addition, the study results suggest that blue ocean strategy fully mediates the relationship between a firm\u27s market orientation and its business performance, while competitive strategy only partially mediates the relationship. We discuss some theoretical implications and contributions of our research findings

    The Relationship between Metacognition, Entrepreneurial Orientation, and Firm Performance: An Empirical Investigation

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    This study aims to examine the relationship between an entrepreneur’s metacognition, entrepreneurial orientation (EO), and firm performance. We collected primary data from 190 entrepreneurs (business owners or founders) working in the U.S. through a survey. By performing both the confirmatory factor analysis (CFA) and the structural equation modeling (SEM), we tested our hypothesized research model that represented the metacognition-EO-firm performance relationship. The results from the statistical analysis demonstrate that an entrepreneur\u27s metacognition has a significant positive impact on EO. Furthermore, the study result shows that EO has a full mediating effect on the relationship between entrepreneurial metacognition and firm performance. We, thus, anticipate that the findings of this study will help entrepreneurs to understand the mechanism on how their metacognitions impact their business outcomes as well as to recognize why they should consider their metacognitive abilities while executing entrepreneurial tasks

    The QM evolution: Behavioral quality management as a firm’s strategic resource

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    Firms implement various quality management (QM) practices to improve process quality. Scholars recognize that QM practices consist of both technical and behavioral oriented practices. The relationship of technical and behavioral oriented practices on performance has led to paradoxical relationships. Improving quality performance necessitates understanding the relationship between technical and behavioral orientated practices. This study empirically examines the relationship between technical and behavioral quality practices by collecting survey data from both US-based (N = 152) and China-based (N = 222) firms. The analysis uses the structural equation modeling technique, and shows that behavioral QM practices fully mediate the relationship between technical QM practices and firm performance. This implies that behavioral QM practices act as a strategic resource which helps generate a competitive advantage. The results contribute to understanding how quality management practices can lead to a competitive advantage

    Cored Dark Matter halos in the Cosmic Neutrino Background

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    We study the impact of the interaction between DM and the cosmic neutrino background on the evolution of galactic dark matter halos. The energy transfer from the neutrinos to the dark matter can heat the center of the galaxy and make it cored. This effect is efficient for the small galaxies such as the satellite galaxies of the Milky Way and we can put conservative constraint on the non-relativistic elastic scattering cross section as σχν1031cm2\sigma_{\chi\nu}\lesssim 10^{-31} {\rm cm}^2 for 0.1 keV dark matter and 0.1 eV neutrino.Comment: 7 pages, 5 figure

    Newly designed coil tube for bowel decompression in patients with small bowel obstructions

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    AbstractBackgroundThe purpose of this study was to clinically evaluate a coil tube that we recently designed for bowel decompression in patients with a small bowel obstruction.MethodsThe coil tube was composed of a stainless steel coil, a polyolefin tube, and a rubber adaptor. The tube was inserted under fluoroscopic guidance in 14 consecutive patients with small bowel obstructions. Technical success was defined as insertion of the distal end of the tube into at least the proximal jejunum, and clinical success was defined as intestinal decompression and relief of obstructive symptoms.ResultsThe technical success rate was 100%. Clinical success was achieved in 12 patients (86%). The clinical failures were a patient with peritoneal carcinomatosis and an ileocolic fistula, and a patient with bezoars following intestinal hemorrhage. No coil-related complications occurred.ConclusionOur newly designed coil tube was safe and effective in patients with bowel decompression associated with a small bowel obstruction. In addition, our tube has several advantages over other currently used tube types

    Non-Hodgkin's lymphoma of the sphenoid sinus presenting as isolated oculomotor nerve palsy

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    BACKGROUND: Solitary involvement of the sphenoid sinus has rarely been reported in non-Hodgkin's lymphoma. Isolated oculomotor nerve palsy is uncommon as an initial presentation of malignant tumors of the sphenoid sinus. CASE PRESENTATION: A 53-year-old woman presented with a three-month history of headache and diplopia. Neurological examination revealed complete left oculomotor nerve palsy. Magnetic Resonance Imaging (MRI) demonstrated a homogenous soft-tissue lesion occupying the left sphenoid sinus and invading the left cavernous sinus. The patient underwent transsphenoidal biopsy and the lesion was histologically diagnosed as non-Hodgkin's lymphoma, diffuse large B-cell type. Tumor cells were positive for CD20 and negative for CD3. Following six cycles of chemotherapy, the left oculomotor nerve palsy that had been previously observed was completely resolved. There was no enhancing lesion noted on follow-up MRI. CONCLUSION: It is important to recognize that non-Hodgkin's lymphoma of the sphenoid sinus can present with isolated oculomotor nerve palsy, although it is extremely rare. The cranial nerve deficits can resolve dramatically after chemotherapy.ope
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