National School of Technology

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Rouiba, Algeria

Everest Institute is a system of for-profit colleges in the United States owned by Corinthian Colleges. They offer career training programs in a wide variety of areas, primarily focused on health care. Originally founded in 1977, NST has four Florida campuses. Wikipedia.


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Zhang J.,Harbin Institute of Technology | Zhao D.,Harbin Institute of Technology | Gao W.,National School of Technology
IEEE Transactions on Image Processing | Year: 2014

Traditional patch-based sparse representation modeling of natural images usually suffer from two problems. First, it has to solve a large-scale optimization problem with high computational complexity in dictionary learning. Second, each patch is considered independently in dictionary learning and sparse coding, which ignores the relationship among patches, resulting in inaccurate sparse coding coefficients. In this paper, instead of using patch as the basic unit of sparse representation, we exploit the concept of group as the basic unit of sparse representation, which is composed of nonlocal patches with similar structures, and establish a novel sparse representation modeling of natural images, called group-based sparse representation (GSR). The proposed GSR is able to sparsely represent natural images in the domain of group, which enforces the intrinsic local sparsity and nonlocal self-similarity of images simultaneously in a unified framework. In addition, an effective self-adaptive dictionary learning method for each group with low complexity is designed, rather than dictionary learning from natural images. To make GSR tractable and robust, a split Bregman-based technique is developed to solve the proposed GSR-driven l0 minimization problem for image restoration efficiently. Extensive experiments on image inpainting, image deblurring and image compressive sensing recovery manifest that the proposed GSR modeling outperforms many current state-of-the-art schemes in both peak signal-to-noise ratio and visual perception. © 1992-2012 IEEE.


Cho I.,National School of Technology | Kwon O.-K.,Sungkyunkwan University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

We study a higher derivative (HD) field theory with an arbitrary order of derivative for a real scalar field. The degree of freedom for the HD field can be converted to multiple fields with canonical kinetic terms up to the overall sign. The Lagrangian describing the dynamics of the multiple fields is known as the Lee-Wick (LW) form. The first step to obtain the LW form for a given HD Lagrangian is to find an auxiliary field (AF) Lagrangian which is equivalent to the original HD Lagrangian up to the quantum level. Until now, the AF Lagrangian has been studied only for N=2 and 3 cases, where N is the number of poles of the two-point function of the HD scalar field. We construct the AF Lagrangian for arbitrary N. By the linear combinations of AF fields, we also obtain the corresponding LW form. We find the explicit mapping matrices among the HD fields, the AF fields, and the LW fields. As an exercise of our construction, we calculate the relations among parameters and mapping matrices for N=2, 3, and 4 cases. © 2010 The American Physical Society.


Yi H.,Seoul National University | Chun J.,Seoul National University | Chun J.,National School of Technology
Systematic and Applied Microbiology | Year: 2012

Phylogenetic analyses based on 16S rRNA gene sequences showed that a bacterial isolate, designated JC2678 T, represents a distinct phyletic line within the suprageneric monophyletic clade containing the genera Nonlabens, Persicivirga, Stenothermobacter and Sandarakinotalea. The polyphasic data presented in this study demonstrated that the members belonging to the Nonlabens-like clade overall constitute a single genus. Therefore, it is proposed to transfer the members of genera Persicivirga O'Sullivan et al. 2006, Stenothermobacter Lau et al. 2006 and Sandarakinotalea Khan et al. 2006 to the genus Nonlabens Lau et al. 2005. Thus, P. dokdonensis (Yoon et al. 2006) Nedashkovskaya et al. 2009, P. ulvanivorans Barbeyron et al. 2010, P. xylanidelens O'Sullivan et al. 2006, Sandarakinotalea sediminis Khan et al. 2006 and Stenothermobacter spongiae Lau et al. 2006 should be transferred to Nonlabens dokdonensis comb. nov., Nonlabens ulvanivorans comb. nov., Nonlabens xylanidelens comb. nov., Nonlabens sediminis comb. nov. and Nonlabens spongiae comb. nov., respectively. In addition, strain JC2678 T (=KACC 14155 T=JCM 17109 T) is proposed to constitute a novel species belonging to the genus Nonlabens with the name of Nonlabens agnitus sp. nov. © 2012 Elsevier GmbH.


Karwa R.,National School of Technology | Chitoshiya G.,Jai Narain Vyas University
Energy | Year: 2013

The paper presents results of an experimental study of thermo-hydraulic performance of a solar air heater with 60° v-down discrete rib roughness on the airflow side of the absorber plate along with that for a smooth duct air heater. The enhancement in the thermal efficiency due to the roughness on the absorber plate is found to be 12.5-20% depending on the airflow rate; higher enhancement is at the lower flow rate. The experimental data have been generated and utilized to validate a mathematical model, which can be utilized for design and prediction of performance of both smooth and roughened air heaters under different operating conditions. The results of a detailed thermo-hydraulic performance study of solar air heater with v-down discrete rib roughness using the mathematical model are also presented along with the effect of variation of various parameters on the performance. © 2013 Elsevier Ltd.


Turner M.M.,National School of Technology
Plasma Sources Science and Technology | Year: 2015

Chemistry models that include dozens of species and hundreds to thousands of reactions are common in low-temperature plasma physics. The rate constants used in such models are uncertain, because they are obtained from some combination of experiments and approximate theories. Since the predictions of these models are a function of the rate constants, these predictions must also be uncertain. However, systematic investigations of the influence of uncertain rate constants on model predictions are rare to non-existent. In this work we examine a particular chemistry model, for helium-oxygen plasmas. This chemistry is of topical interest because of its relevance to biomedical applications of atmospheric pressure plasmas. We trace the primary sources for every rate constant in the model, and hence associate an error bar (or equivalently, an uncertainty) with each. We then use a Monte Carlo procedure to quantify the uncertainty in predicted plasma species densities caused by the uncertainty in the rate constants. Under the conditions investigated, the range of uncertainty in most species densities is a factor of two to five. However, the uncertainty can vary strongly for different species, over time, and with other plasma conditions. There are extreme (pathological) cases where the uncertainty is more than a factor of ten. One should therefore be cautious in drawing any conclusion from plasma chemistry modelling, without first ensuring that the conclusion in question survives an examination of the related uncertainty. © 2015 IOP Publishing Ltd.


Kim E.-K.,National School of Technology
Microelectronics Reliability | Year: 2010

3D integration with multi-stacked wafers is a promising option to enhance device performance and density beyond traditional device scaling limits. However, to bring wafer stacking into reality, there are many technological challenges to be resolved, and one of those is the problem of uniform Si wafer thinning. For multi-stacked devices, Si wafers must be drastically thinned down to less than 50 μm. Problems associated with such ultra-thin Si wafers range from basic wafer handling to difficulty in accurately assessing the thickness of the thinned wafer across the wafer. In this study, bonded wafer pairs have been prepared with different bonding materials, and the stacks were ground down to about 30 μm. The thickness of the ultra-thin wafers was measured by Fourier transform infrared spectrometry (FTIR) technique, and its stability based on bonding status as well as measuring issues will be discussed. © 2009 Elsevier Ltd. All rights reserved.


Sun Y.C.,National School of Technology
Beijing da xue xue bao. Yi xue ban = Journal of Peking University. Health sciences | Year: 2013

To take the Real-time measurement of the intra-pulpal temperature (IPT) when using femtosecond laser in specific parameters to prepare cavities in tooth enamel in vitro, and to preliminarily evaluate the effect of air cooling. All pulp champers of extracted human teeth (premolars and molars) were exposed by roots amputated and pulp scraped out. All chambers were tightly filled with copper powder, and thermocouple was inserted into the center of the powder stack. The bottom of the chamber was sealed with insulating tape. Thermocouple wire was fixed at the same time. The 2.25 mm×2.25 mm square cavities were prepared using femtosecond laser in the enamel with the average scan speed of 0.4 mm/s. The real-time IPT change was measured with thermocouple digital thermometer. Air cooling was added to the procedure once the temperature increased to reach a balance. The IPT rising was defined as ΔT . Before the usage of air cooling, the maximum of the ΔT value of the sample premolar was 12.3 °C. After using air cooling, the IPT decreased and ΔT value became 3.0 °C . The maximum of ΔT of the sample molar before using air cooling was 1.8 °C , and decreased to -0.1 °C after it. When preparing a cavity whose average depth is about 250 μm by femtosecond laser system in specific parameters, the IPT rises while the depth increass, but it could be controlled effectively by air cooling.


Park K.,National School of Technology | Lee S.-I.,National School of Technology
Journal of Micromechanics and Microengineering | Year: 2010

High-frequency induction is an efficient, non-contact means of heating the surface of an injection mold through electromagnetic induction. Because the procedure allows for the rapid heating and cooling of mold surfaces, it has been recently applied to the injection molding of thin-walled parts or micro/nano-structures. The present study proposes a localized heating method involving the selective use of mold materials to enhance the heating efficiency of high-frequency induction heating. For localized induction heating, a composite injection mold of ferromagnetic material and paramagnetic material is used. The feasibility of the proposed heating method is investigated through numerical analyses in terms of its heating efficiency for localized mold surfaces and in terms of the structural safety of the composite mold. The moldability of high aspect ratio micro-features is then experimentally compared under a variety of induction heating conditions. © 2010 IOP Publishing Ltd.


Zhu Z.,National School of Technology | Zhu L.,National School of Technology
Journal of Power Sources | Year: 2014

The layered 0.5Li2MnO3·0.5LiMn 1/3Ni1/3Co1/3O2 lithium-rich manganese-based solid solution cathode material has been synthesized by two-step co-precipitation method. X-ray diffraction studies reveal that the as-prepared material has a typical layered structure with R-3m and C2/m space group. The surface morphology of the [Mn4/6Ni1/6Co 1/6]CO3 precursor and cathode material 0.5Li 2MnO3·0.5LiMn1/3Ni1/3Co 1/3O2 have been examined using scanning electron microscopy. Electrochemical performances, including discharge capacity, cycling performance and rate capability also have been investigated. The results show that the cathode material 0.5Li2MnO3·0.5LiMn 1/3Ni1/3Co1/3O2 prepared by two-step co-precipitation method has a good electrochemical performance, which can deliver a high initial discharge capacity of 276.70 mAh g-1 at the current density of 25 mA g-1. When cycling at 125 mA g-1, the material indicates an initial discharge capacity of 211.31 mAh g -1 and 196.64 mAh g-1 after 50 cycles, capacity retention is 93.06% and its coulombic efficiencies is greater than 98% at each charge/discharge cycling. Furthermore, the as-prepared material 0.5Li 2MnO3·0.5LiMn1/3Ni1/3Co 1/3O2 also shows an excellent rate capacity. © 2014 Elsevier B.V. All rights reserved.


Li J.,National School of Technology | Tian Y.,National School of Technology | Huang T.,National School of Technology
International Journal of Computer Vision | Year: 2014

Visual saliency is a useful cue to locate the conspicuous image content. To estimate saliency, many approaches have been proposed to detect the unique or rare visual stimuli. However, such bottom-up solutions are often insufficient since the prior knowledge, which often indicates a biased selectivity on the input stimuli, is not taken into account. To solve this problem, this paper presents a novel approach to estimate image saliency by learning the prior knowledge. In our approach, the influences of the visual stimuli and the prior knowledge are jointly incorporated into a Bayesian framework. In this framework, the bottom-up saliency is calculated to pop-out the visual subsets that are probably salient, while the prior knowledge is used to recover the wrongly suppressed targets and inhibit the improperly popped-out distractors. Compared with existing approaches, the prior knowledge used in our approach, including the foreground prior and the correlation prior, is statistically learned from 9.6 million images in an unsupervised manner. Experimental results on two public benchmarks show that such statistical priors are effective to modulate the bottom-up saliency to achieve impressive improvements when compared with 10 state-of-the-art methods. © 2013 Springer Science+Business Media New York.

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