TERRORIST ATTACKS AND CORPORATE INVESTMENT IN INDONESIA

Using yearly data from 1997 to 2017, this paper studies the effect of terrorism (number of attacks) on corporate investment in Indonesia. Applying an investment-type model, we show that firms reduce their capital expenditure due to an increase in the number of terrorist attacks. On average, a one standard deviation increase in the number of terrorist attacks reduces corporate investment by 9.23%. We also find heterogenous reactions of firms to terrorism across different sectors and different panels based on firm characteristics. Finally, our main results remain consistent after performing several robustness tests

Numerical analysis of initial amount of substrate and biomass in substrate inhibition process

-The process of inhibition of enzymes is important because it serves as a fundamental control mechanism in many biological systems and allows the regulation of metabolic pathways. In fact, many medications act by inhibiting specific enzymes in the brain or in body tissues. Therefore, the understanding of enzymatic inhibition mechanism is, essential. Inhibitors are frequently used as tools for the study of the mechanism of the enzymes themselves. In the present paper we have studied the process of substrate inhibition by developing a mathematical model that allow us to understand the influence of initial amount of substrate and initial biomass concentration on maximum growth rate value. Numerical analysis using Matlab software was performed to model this inhibition process. © 2018, World Scientific and Engineering Academy and Society. All rights reserved

Modified sunflower optimization for network reconfiguration and distributed generation placement

This paper proposed modified sunflower optimization (MSFO) for the combination of network reconfiguration and distributed generation placement problem (NR-DGP) to minimize power loss of the electric distribution system (EDS). Sunflower optimization (SFO) is inspired form the ideal of sunflower plant motion to get the sunlight and its reproduction. To enhance the performance of SFO, it is modified to MSFO wherein, the pollination and mortality techniques have been modified by using Levy distribution and mutation of the best solutions. The results are evaluated on two test systems. The efficiency of MSFO is compared with that of the original SFO and other algorithms in literature. The comparisons show that MSFO outperforms to SFO and other methods in obtained optimal solution. Furthermore, MSFO demonstrates the better statistical results than SFO. So, MSFO can be a powerful approach for the NR-DGP problem

Potential Usage of Rice Husk Ash-Cement Based Soil in Subbase and Base Courses in Road Construction

This paper presents an experimental study of rice husk ash-cement-based soil for layers in roadway construction. Rice husk ash (RHA) used in this study is a by-product of rice milling. In this work, twelve proportion mixes were used in this work with varying quantities of RHA (0-30%) and Portland cement blended amounts of 4, 6, 8%. The specimens were prepared by the Proctor mould method, conditioned at room temperature, and tested in soaked and unsoaked conditions. Specified curing periods of 7, 14, 28 days were applied for all types of specimens. Some engineering tests were carried out such as proctor compaction, unconfined compressive strength, splitting tensile strength, and the stiffness of stabilized soil. Test results indicated a general decrease in the maximum dry density (MDD) and increased optimum moisture content (OMC) with an increase in RHA content. Adding cement and RHA significantly improved the geotechnical properties of stabilized soils, including compressive strength, splitting tensile strength, elastic modulus. In addition, the combination of 80% soil and 20% RHA and 6% cement can be used as the optimum proportion which satisfied the grade 3 of soils stabilized with inorganic adhesive substances, chemical agents, or reinforced soil for road construction, as indicated in the current Vietnamese standard

Potential Usage of Rice Husk Ash-Cement Based Soil in Subbase and Base Courses in Road Construction

This paper presents an experimental study of rice husk ash-cement-based soil for layers in roadway construction. Rice husk ash (RHA) used in this study is a by-product of rice milling. In this work, twelve proportion mixes were used in this work with varying quantities of RHA (0-30%) and Portland cement blended amounts of 4, 6, 8%. The specimens were prepared by the Proctor mould method, conditioned at room temperature, and tested in soaked and unsoaked conditions. Specified curing periods of 7, 14, 28 days were applied for all types of specimens. Some engineering tests were carried out such as proctor compaction, unconfined compressive strength, splitting tensile strength, and the stiffness of stabilized soil. Test results indicated a general decrease in the maximum dry density (MDD) and increased optimum moisture content (OMC) with an increase in RHA content. Adding cement and RHA significantly improved the geotechnical properties of stabilized soils, including compressive strength, splitting tensile strength, elastic modulus. In addition, the combination of 80% soil and 20% RHA and 6% cement can be used as the optimum proportion which satisfied the grade 3 of soils stabilized with inorganic adhesive substances, chemical agents, or reinforced soil for road construction, as indicated in the current Vietnamese standard

A Unified Approach for Multi-Scale Synchronous Correlation Search in Big Time Series -- Full Version

The wide deployment of IoT sensors has enabled the collection of very big time series across different domains, from which advanced analytics can be performed to find unknown relationships, most importantly the correlations between them. However, current approaches for correlation search on time series are limited to only a single temporal scale and simple types of relations, and cannot handle noise effectively. This paper presents the integrated SYnchronous COrrelation Search (iSYCOS) framework to find multi-scale correlations in big time series. Specifically, iSYCOS integrates top-down and bottom-up approaches into a single auto-configured framework capable of efficiently extracting complex window-based correlations from big time series using mutual information (MI). Moreover, iSYCOS includes a novel MI-based theory to identify noise in the data, and is used to perform pruning to improve iSYCOS performance. Besides, we design a distributed version of iSYCOS that can scale out in a Spark cluster to handle big time series. Our extensive experimental evaluation on synthetic and real-world datasets shows that iSYCOS can auto-configure on a given dataset to find complex multi-scale correlations. The pruning and optimisations can improve iSYCOS performance up to an order of magnitude, and the distributed iSYCOS can scale out linearly on a computing cluster.Comment: 18 page

Adsorptive removal of Pb (II) using exfoliated graphite adsorbent:influence of experimental conditions and magnetic CoFe2O4 decoration

The worm-like exfoliated graphite (EG) based adsorbents prepared from low-cost natural graphite flakes via facile synthesis processes have been found to be efficient adsorbents when it comes to removing Pb (II) from aqueous solution. EG was fabricated by chemical intercalation and microwave assisted exfoliation. Furthermore, the magnetic exfoliated graphite (MEG) was developed by incorporating CoFe2O4 particles into the EG layers using the citric acid based sol-gel technique. Adsorption behaviour of Pb (II) on the as-prepared adsorbents was investigated by taking several experimental conditions into consideration such as contact time, initial concentration, adsorbent dosage, and pH value. The results with initial neutral pH indicated that the adsorption isotherms for Pb (II) on the EG and MEG were well consistent with the Langmuir isotherm model revealing the maximum adsorption capacity of 106 mg/g and 68 mg/g for EG and MEG, respectively. The adsorption kinetics of Pb (II) was found to adhere to the pseudo-second-order kinetic model. The chemical interaction between ? electrons on graphite sheets and Pb (II) ions was suggested to play an essential role in the adsorption mechanism. The introduction of magnetic CoFe2O4 to the EG was found to induce the shift of optimal pH value to a more basic condition. The characterization of the adsorbents was performed using relevant analysis techniques such as Scanning electron microscope (SEM), X–ray powder diffraction (XRD), vibrating-sample magnetometer (VSM), and Fourier-transform infrared (FTIR). The results of this work suggest a high possibility for application of the as-prepared modified graphite to remove hazardous substances in practical wastewater treatment systems. ABSTRAK:  Penyerap Pengelupas Grafit (EG) yang berupa seperti cacing dihasilkan dari grafit semulajadi yang murah melalui proses sintesis serpihan, ia juga merupakan penyerap yang bagus dalam mengasingkan Pb (II) daripada larutan akues. EG direka dengan tindak balas interkalasi kimia dan pengelupasan melalui gelombang mikro. Tambahan, pengelupas grafit magnet (MEG) telah dihasilkan dengan memasukkan zarah CoFe2O4 ke dalam lapisan EG menggunakan teknik sol-gel yang berasaskan asid sitrik. Tindak balas penyerapan Pb (II) pada penyerap yang disiapkan ini, dikaji dengan mengambil kira beberapa keadaan eksperimen seperti waktu disentuh, konsentrasi awal, dos penyerap dan nilai pH.  Hasil keputusan pH neutral awal menunjukkan bahawa isoterm penyerapan bagi Pb (II) pada EG dan MEG adalah konsisten dengan model isoterm Langmuir. Ini menunjukkan kapasiti penyerapan maksimum 106 mg/g dan 68 mg/g bagi EG dan MEG, masing-masing. Penyerapan kinetik Pb (II) didapati mematuhi model kinetik pesudo-order-kedua. Interaksi kimia antara elektron ? pada helaian grafit dan ion Pb (II) memainkan peranan penting dalam mekanisme penyerapan. Pengenalan magnet CoFe2O4 kepada EG didapati telah mengubah nilai pH optimum kepada keadaan asal. Pengelasan penyerapan dilakukan menggunakan teknik analisis yang relevan seperti Mikroskop Elektron Pengimbasan (SEM), Difraksi Serbuk sinar-X (XRD), Magnetometer Sampel-Getaran (VSM) dan Inframerah Perubahan-Fourier (FTIR). Hasil kerja ini mencadangkan kemungkinan besar bagi penggunaan grafit ubah suai yang disediakan bagi membuang bahan berbahaya dalam sistem rawatan air sisa praktikal