1,838 research outputs found
Feature Reduction Based on Sum-of-SNR (SOSNR) Optimization
Dimensionality reduction plays an important role in machine learning techniques. In classification, data transformation aims to reduce the number of feature dimensions, whereas attempts to enhance the class separability. To this end, we propose a new classifier-independent criterion called 'Sum-of-Signal-to-Noise-Ratio' (SoSNR). A framework designed for maximization with respect to this criterion is presented and three types of algorithms, respectively based on (1) gradient, (2) deflation and (3) sparsity, are proposed. The techniques are conducted on standard UCI databases and compared to other related methods. Results show trade-offs between computational complexity and classification accuracy among different approaches
Superconductivity near the vibrational mode instability in MgCNi3
To understand the role of electron-phonon interaction in superconducting
MgCNi we have performed density functional based linear response
calculations of its lattice dynamical properties. A large coupling constant = 1.51 is predicted and contributing phonons are identified as
displacements of Ni atoms towards octahedral interstitials of the perovskite
lattice. Instabilities found for some vibrational modes emphasize the role of
anharmonic effects in resolving experimental controversies.Comment: 4 pages, 4 eps figures, replaces the older versio
Ridge-Adjusted Slack Variable Optimization for Supervised Classification
This paper presents an iterative classification algorithm called Ridge-adjusted Slack Variable Optimization (RiSVO). RiSVO is an iterative procedure with two steps: (1) A working subset of the training data is selected so as to reject "extreme" patterns. (2) the decision vector and threshold value are obtained by minimizing the energy function associated with the slack variables. From a computational perspective, we have established a sufficient condition for the "inclusion property" among successive working sets, which allows us to save computation time. Most importantly, under the inclusion property, the monotonic reduction of the energy function can be assured in both substeps at each iteration, thus assuring the convergence of the algorithm. Moreover, ridge regularization is incorporated to improve the robustness and better cope with over-fitting and ill-conditioned problems. To verify the proposed algorithm, we conducted simulations on three data sets from the UCI database: adult, shuttle and bank. Our simulation shows stability and convergence of the RiSVO method. The results also show improvement of performance over the SVM classifier
What do they eat? A survey of eat-out habit of university students in Taiwan
[EN] Main purpose of this research is trying to understand food likeliness of
Taiwan college students, and probe whether these food are healthy. Three
survey steps are taken as: step 1, market survey for what kind of foods are
selling around the campuses; step 2, questionnaire investigation for students
food preference; step 3, analyzing whether these favorite foods are healthy or
not. The result shows: major consideration for students food selection are
“taste” and “price”; 63% of students are taking food or snacks late at night
at least once a week. Top three most favorite foods are: Taiwanese fries (yan
su ji), carbon grilled chicken and fried fish steaks. Quantities of these foods
are small, prices are low, and easy access from roadside food stands.
Problems of them are high calories, easy to accumulate free radical in
human body, plus insanitary food processing environment. They are harmful
to student health. We suggest Taiwan government take it seriouslyShih, K.; Wang, M.; Shih, H.; Lee, S.; Lin, T. (2020). What do they eat? A survey of eat-out habit of university students in Taiwan. Editorial Universitat Politècnica de València. 421-430. https://doi.org/10.4995/INN2019.2019.10562OCS42143
Thermodynamics of 2D string theory
We calculate the free energy, energy and entropy in the matrix quantum
mechanical formulation of 2D string theory in a background strongly perturbed
by tachyons with the imaginary Minkowskian momentum
(``Sine-Liouville'' theory). The system shows a thermodynamical behaviour
corresponding to the temperature . We show that the
microscopically calculated energy of the system satisfies the usual
thermodynamical relations and leads to a non-zero entropy.Comment: 13 pages, lanlmac; typos correcte
Comment on "Experimental determination of superconducting parameters for the intermetallic perovskite superconductor MgCNi"
In a recent paper (Phys. Rev. {\bf B 67}, 094502 (2003)) Mao et al.
investigated the bias-dependent conductance of mechanical junctions between
superconducting MgCNi and a sharp W tip. They interpreted their results in
terms of 'single-particle tunneling'. We show it is more likely that current
transport through those junctions is determined by thermal effects due to the
huge normal-state resistivity of MgCNi. Therefore no conclusion can be
drawn about the possible unconventional pairing or strong-coupling
superconductivity in MgCNi.Comment: 2 pages, 1 Fig. Comment on Z. Q. Mao et al. (Phys. Rev. {\bf B 67},
094502 (2003)
Work-related helping and family functioning: a work-home resources perspective
Using the work–home resources (W-HR) model as an overarching framework, our study seeks to examine the interplay between employees’ provision and receipt of interpersonal organizational citizenship behaviours (OCB-I; i.e. helping behaviours), and its spillover effects on two family outcomes (family performance and marital withdrawal behaviours). Further, we simultaneously test resource depletion (emotional exhaustion) and resource generation (personal accomplishment) mechanisms linking OCB-Is and the family domain. Based on a time-lagged, dual-source study of 320 employees, we found that OCB-I enactment is positively related to both exhaustion (only for those who receive low OCB-Is from colleagues) and personal accomplishment at work (regardless of OCB-I receipt), which interferes with and enriches employees’ family lives, respectively. We discuss the theoretical contributions of these findings to OCB research and the W-HR model
Применение Беспилотных Летательных Аппаратов Для Оценки Качества Растительности
The use of Earth remote sensing (ERS) in agriculture is related with inventory of arable areas, detection of soil erosion, bogging. At present great attention is paid to studies devoted to determination of productivity of arable areas based on ERS data under various climatic conditions. Satellite images are characterized by certain drawbacks such as low resolution, impossibility to acquire images from behind clouds. A promising approach to obtain high precision maps is the use of unmanned aerial vehicles (UAV).The degree of crop development is estimated by their NDVI which is used in numerous photometric instruments for diagnostics of plant nitrogenous nutrition. With this aim, the UAV camera detects plant reflection intensity of sunlight or induced light in red (P NIR) and infrared (P RED) spectra. Thus, it becomes necessary to determine mechanisms and interrelation of vegetation index which would permit to obtain data on crop productivity on the basis of data from UAV.Использование данных дистанционного зондирования Земли (ДДЗ) в сельском хозяйстве связано с инвентаризацией сельхозугодий, обнаружением эрозии почвы, заболачивания. В последние годы большой интерес приобретают исследования, направленные на выявления урожайности сельскохозяйственных культур с данными ДДЗ в различных климатических условиях. Использование космических снимков имеет ряд недостатков, таких как: низкое разрешение, невозможность получения их из-за облаков. Одним из перспективных путей решения получения высокоточных карт является применение беспилотных летательных аппаратов (БПЛА). Для оценки степени развития посевов обычно применяют их вегетационный NDVI, который используется во многих фотометрических приборах для диагностики азотного питания растений. Для этого в фотокамере БПЛА предусмотрена фиксация интенсивности отражения растениями солнечного или индуцированного света в красной (P NIR) и инфракрасной (P RED) областях спектра. Исходя из этого возникает необходимость проведения в исследований по выявлению механизмов и взаимосвязи вегетационного индекса, что позволит получать информацию о продуктивности сельскохозяйственных культур, используя данные с беспилотного летательного аппарата
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