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Analyzing Effective of Activation Functions on Recurrent Neural Networks for Intrusion Detection
Le, Thi-Thu-Huong,Kim, Jihyun,Kim, Howon Korea Multimedia Society 2016 The journal of multimedia information system Vol.3 No.3
Network security is an interesting area in Information Technology. It has an important role for the manager monitor and control operating of the network. There are many techniques to help us prevent anomaly or malicious activities such as firewall configuration etc. Intrusion Detection System (IDS) is one of effective method help us reduce the cost to build. The more attacks occur, the more necessary intrusion detection needs. IDS is a software or hardware systems, even though is a combination of them. Its major role is detecting malicious activity. In recently, there are many researchers proposed techniques or algorithms to build a tool in this field. In this paper, we improve the performance of IDS. We explore and analyze the impact of activation functions applying to recurrent neural network model. We use to KDD cup dataset for our experiment. By our experimental results, we verify that our new tool of IDS is really significant in this field.
Le, Thu-Huong,Jeong, Hyun-Dam The Royal Society of Chemistry 2014 Physical chemistry chemical physics Vol.16 No.35
<P>Optical properties of silicon quantum dots (Si QDs) are greatly influenced by their size and surface chemistry. We report the micro-emulsion synthesis of hydrogen terminated Si QDs, with the modification of quenching the remaining reducing agent LiAlH<SUB>4</SUB> with CuSO<SUB>4</SUB>. Subsequent functionalization was carried out with different capping molecules, including 1-octene, phenylacetylene, and 1,4-diethynylbenzene, to give octyl, styryl, and 4-ethynylstyryl terminated silicon quantum dots, respectively. The optical properties of the three kinds of Si QD synthesized, with the extended conjugation length, were examined. The effects of surface chemistry on the optical properties of the Si QD, obtained using ultraviolet-visible absorption spectroscopy and photoluminescence spectroscopy, were compared to the extension of electron and hole wavefunctions into the capping molecules, which were estimated from modified particles in a box calculation. The observed quantum yield increased from 2% to 2.5% and 9.0% and the average lifetime decreased with increasing conjugation length of the octyl Si QD, the styryl Si QD, and the 4-ethynylstyryl Si QD, which were ascribed to the effect of electronic coupling between the capping molecules and the Si QD. A tentative model in which the strong electronic interaction through covalent bonding induced a more direct band gap character for light emission was proposed by tuning the ground state wavefunctions of the electron and hole in wave vector space.</P> <P>Graphic Abstract</P><P>Optical properties of silicon quantum dots (Si QDs) are greatly influenced by their size and surface chemistry. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4cp02657h'> </P>
Thu-Huong Le,Hyun-Dam Jeong 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.5
Silicon quantum dots (Si QDs) were synthesized by etching silicon nanopowder with aqueous hydrofluoric acid (HF) and nitric acid (HNO3). Then, the hydride-terminated Si QDs (H-Si QDs) were functionalized by 1- octadecene (ODE). By only controlling the etching time, the maximum luminescence peak of octadecylterminated Si QDs (ODE-Si QDs) was tuned from 404 nm to 507 nm. The average optical gap was increased from 2.60 eV (ODE-Si QDs-5 min) for 5 min of etching to 3.20 eV (ODE-Si QDs-15 min) for 15 min of etching, and to 3.40 eV (ODE-Si QDs-30 min) for 30 min of etching. The electron affinities (EA), ionization potentials (IP), and quasi-particle gap [수식] of the Si QDs were determined by cyclic voltammetry (CV). The quasi-particle gaps obtained from the CV were in good agreement with the average optical gap values from UV-vis absorption. In the case of the ODE-Si QDs-30 min sample, the difference between the quasi-particle gap and the average optical gap gives the electron-hole Coulombic interaction energy. The additional electronic levels of the ODE-Si QDs-30 min and ODE-Si QDs-15 min samples determined by the CV results are interpreted to have originated from the Si=O bond terminating Si QD.
Le, Thu-Huong,Kim, Ki-Jeong,Jeong, Hyun-Dam American Chemical Society 2017 The Journal of Physical Chemistry Part C Vol.121 No.29
<P>Colloidal 4-ethynylstyryl and octyl cocapping silicon quantum dot (4-Es/Oct Si QD) and its spin-coated film were synthesized and fabricated at three different curing temperatures, 150, 250, and 350 degrees C under argon for 4 h. Thermal cross-linking of 4-ethynylstyryl-terminated 4-Es/Oct Si QD during the curing process was confirmed by differential scanning calorimetry for the 4-Es/Oct Si QD powder and by Fourier transform infrared spectroscopy for the Si QD thin films. The effect of thermal cross-linking of 4-ethynylstyryl capping groups on the electronic coupling between Si QDs in Si QD solids of thin film states was investigated by monitoring optical and electrical properties of the Si QD thin films at different curing temperatures. The valence-band spectra of 4-Es/Oct Si QD thin films obtain from high-resolution photoemission spectroscopy at 130 eV showed the shift to lower binding energy as curing temperature increases from 150 to 350 degrees C. The optical bandgap values estimated from the extinction-coefficient graphs of 4-Es/Oct Si QD thin films are 2.83, 2.7, and 2.45 eV at the curing temperature of 150, 250, and 350 degrees C, respectively. Moreover, ultraviolet visible absorbance and photoluminescence spectroscopy of the Si QD thin films showed a distinct extension into the longer-wavelength, whereas the absolute photoluminescence quantum yield of 4-Es/Oct Si QD thin films decreases from 1.33%, 1.33%, 1.12%, to 0.96% at the curing temperature of 80 (as-prepared), 150, 250, and 350 degrees C, respectively. In addition, their current voltage measurements showed an increased leakage current with increasing curing temperatures. The thermal cross-linking of 4-ethynylstyryl capping groups at curing temperatures of 250 and 350 degrees C and thermal decomposition of octyl capping groups at 350 degrees C decrease width and height of the energy barrier between the two QD neighbors, allow the expansion of the wave functions of individual Si QDs, and overlap with the neighboring QDs, thus strengthening electronic coupling between the Si QDs in QD solids, inducing significant changes in the valence band-edge, optical, and electrical properties.</P>