Local Self-Energy Approach For Electronic Structure Calculations

Using a novel self-consistent implementation of Hedin's GW perturbation theory we calculate space and energy dependent self-energy for a number of materials. We find it to be local in real space and rapidly convergent on second-- to third-- nearest neighbors. Corrections beyond GW are evaluated and shown to be completely localized within a single unit cell. This can be viewed as a fully self consistent implementation of the dynamical mean field theory for electronic structure calculations of real solids using a perturbative impurity solver.Comment: 5 pages, 2 figure

Linear Response Calculations of Lattice Dynamics in Strongly Correlated Systems

We introduce a new linear response method to study the lattice dynamics of materials with strong correlations. It is based on a combination of dynamical mean field theory of strongly correlated electrons and the local density functional theory of electronic structure of solids. We apply the method to study the phonon dispersions of a prototype Mott insulator NiO. Our results show overall much better agreement with experiment than the corresponding local density predictions.Comment: 4 pages, 2 figure

Self-consistent Green function approach for calculations of electronic structure in transition metals

We present an approach for self-consistent calculations of the many-body Green function in transition metals. The distinguishing feature of our approach is the use of the one-site approximation and the self-consistent quasiparticle wave function basis set, obtained from the solution of the Schrodinger equation with a nonlocal potential. We analyze several sets of skeleton diagrams as generating functionals for the Green function self-energy, including GW and fluctuating exchange sets. Their relative contribution to the electronic structure in 3d-metals was identified. Calculations for Fe and Ni revealed stronger energy dependence of the effective interaction and self-energy of the d-electrons near the Fermi level compared to s and p electron states. Reasonable agreement with experimental results is obtained

Inovasi Gadjah Mada Bamboo Shelter (GAMBOOSTER) sebagai Smart And Eco Friendly Temporary Shelter Bagi Korban Bencana

Various regions in Indonesia are often had a natural disaster. Ironically handling of post-disaster still seem indolent and not ready especially fullfill requirement of shelters. Orientation of the above problem, we have an innovations arise to make shelters with various of design concept, include : shelters that can harvest the rain water, earthquake resistant, eco friendly materials, get implementing smart technology system as a puzzle and implement the dynamic wall system. The main materials used in our innovation is bamboo with the economic, low cost and sustainable when it compared to wood or aother materials. Same with implementing of other building work, temporary shelter that we construct need standart tools equipment builders. This activity is divided in two types of work, there\u27s fabrication site and construction site. On the implementation phase, we can starting from a literature search and discussion, survey tools and materials, permitting laboratories and make a shop drawing. After that, we can make the temporary shelters from the procurement of equipment and materials, work columns, beams, sloof, the walls and floor plate work, trust and roof work, finishing, construction phase and packaging. This product innovation is also equipped with a guide book for constructed, so our expectation is the temporary shelter can construct with effective and effisienly

Spectrally Efficient FDM System with Probabilistic Shaping

This work proposes and explores the use of probabilistic shaping for the non-orthogonal multicarrier spectrally efficient frequency division multiplexing (SEFDM) system. The system design considers the reverse concatenation architecture which cascades the constant composition distribution matching (CCDM) algorithm together with soft-decision forward error correction (SD-FEC)-LDPC code for the probabilistic shaping scheme. The non-orthogonal signalling is implemented by discrete Fourier transform (DFT)-based SEFDM modulation with matched filtering demodulation and advanced interference cancellation detection. The high achievable spectral efficiency, low computation complexity and reliability make SEFDM a good candidate for multicarrier signalling for beyond 5G communications. By adding extra shaping gain and flexibility of rate adaptation, the combination of two capacity-achieving techniques provides significant insight of further performance improvement. In this paper, we investigate the performance of the proposed probabilistically shaped-SEFDM (PS-SEFDM) system with regular QAM constellations. The presented results of the proposed system show less required power and bandwidth saving compared to OFDM when achieving the same error performance and same spectral efficiency

Probabilistic Shaping for Multidimensional Signals with Autoencoder-based End-to-end Learning

This work proposes a system that optimises multidimensional signal transmission, utilising signals with probabilistic shaping designed with the aid of end-to-end learning of an autoencoder-based architecture. For the first time, this work reports bit mapping optimisation for multidimensional signals and applied the newly derived optimised signals to the probabilistic shaping system. The autoencoder employs two neural networks for the transceiver, separated by the embedded channel. The optimisation of the autoencoder configuration is implemented for probabilistic shaping for n-dimensional signals. Specifically, We investigate a 4-dimensional (4D) signal employing 2 successive time slots that has better noise immunity relative to regular 2-dimensional quadrature amplitude modulation (QAM) signals. We propose a new application of autoencoders in communication systems based on 4D signals and apply machine learning to optimise the 4D probabilistic shaping on the basis of receiver signal-to-noise-ratio (SNR). The performance of the optimised probabilistically shaped 4D signals is evaluated in terms of the bit error rate (BER) and mutual information. Simulation results show that the proposed probabilistically shaped 4D signal achieves better BER performance relative to the unshaped 4D and regular 2D QAM. We demonstrate the mutual information of the proposed signal with varying SNR, showing its improved capacity in comparison with other constellations

A Multimodal Analysis of Advertisement of Online Marketplace Shopee

High human mobility demands the world of commerce to be able to provide services and goods quickly according to consumer demand. To overcome this phenomenon, now appears transactions that use the internet media to connect producers and consumers known as online marketplace. This research studies the advertisement in online marketplace named Shopee by using multimodal analysis. Shopee is an online marketplace app for buying and selling on mobile phones with ease and quickly offering a wide range of products. This research deals with linguistic and visual analysis. This research is focused on the function of the advertisement realized in the offer goods for buyers interested to see and buy that found and dominates in the online marketplace named Shopee. Multimodal analysis method that is used in the research is text verbal analysis theory in language metafunction such as ideational, interpersonal, and textual metafunction by Halliday (1994), while visual text using multimodal analysis by Kress and Van Leuwen (1996, 2006) and Cheong (2004). The result of multimodal analysis of advertisement of online marketplace Shopee is described in linguistic and visual analysis.   Keywords: multimodal, metafunctions of language, advertisement, Shope

Pengaruh Stock Split terhadap Harga dan Likuiditas Saham

This study aimed to analyze the effect of stock split announcement to the stock priceand liquidity in the Indonesian Stock Exchange by taking a sample of 34 firms in theperiod 2002 to 2005. During the study period 111 days, divided into two periods,100 day estimation period and event period 11 days including five days before, oneday events, and five days after. To examine the changes in prices made during thetest period abnormal return events with analysis based on the concept of marketmodel. Observed stock liquidity through trading activities/Tranding Volume Activity(TVA). The testing device used is one sample t-test and paired sample t-test. Theresults show that there is a significant abnormal return on stock split, there aresignificant differences in abnormal return between the periods before and after thestock split, and there was no significant difference in the activity of stock tradingvolume between the period before and after the stock spl

Beam-Pattern Assisted Low-Complexity Beam Alignment for Fixed Wireless mmWave xHaul

This paper presents the design of two-stage beam alignment methods employing a hybrid analog-digital antenna array and exploiting the beam pattern in a point-to-point millimeter-wave (mmWave) radio for mmWave massive multiple-input multiple-output systems. We investigate an antenna deactivating approach that generates wider beams at the coarse alignment stage and exploit the theoretical beam pattern at the fine alignment stage. Our numerical results show that the proposed two-stage methods can achieve a better beam alignment than existing exhaustive methods and avail measurements/complexity reductions by tuning key parameters governing the alignment performance

Ab initio phonon dispersion curves and interatomic force constants of barium titanate

The phonon dispersion curves of cubic BaTiO_3 have been computed within a first-principles approach and the results compared to the experimental data. The curves obtained are very similar to those reported for KNbO_3 by Yu and Krakauer [Phys. Rev. Lett. 74, 4067 (1995)]. They reveal that correlated atomic displacements along chains are at the origin of the ferroelectric instability. A simplified model illustrates that spontaneous collective displacements will occur when a dozen of aligned atoms are coupled. The longitudinal interatomic force constant between nearest neighbour Ti and O atoms is relatively weak in comparison to that between Ti atoms in adjacent cells. The small coupling between Ti and O displacements seems however necessary to reproduce a ferroelectric instability.Comment: 12 pages, 4 figure