• Fabrication and transfer printing of periodic Pt nanonetwork gratings

      Yu, Miao; Li, Li; Wu, Xiaomin; Song, Yingying; Liu, Jinyun; Wang, Zuobin; Changchun University of Science and Technology; University of Bedfordshire (AIP Publishing, 2020-03-13)
      Metal nanonetworks are applied in various applications, such as biomedicine, bionic materials, optical materials, and new energy materials. Here, periodic variable-sized Pt nanonetwork gratings (PtNGs) are fabricated on the surface of a Pt/Si substrate with single pulse two-beam direct laser interference lithography. The fabricated PtNGs are transferred onto the surface of a glass substrate with polymethyl methacrylate as the transfer mediator. Exposure with different film thicknesses, contrasts, and intensity distributions of the laser interference spot is analyzed, and the formation of nanopatterns is explained. Results show that with the change in the thicknesses of the Pt film, the exposed structures present Pt nanoparticles (PtNPs), Pt gratings, and PtNGs. The morphology and the feature size of the PtNGs are influenced by intensity distributions and the contrast of the laser interference spot significantly.
    • Fabrication of biomimetic superhydrophobic and anti-icing Ti6Al4V alloy surfaces by direct laser interference lithography and hydrothermal treatment

      Liu, Ri; Chi, Zhengdong; Cao, Liang; Weng, Zhankun; Wang, Lu; Li, Li; Saeed, Sadaf; Lian, Zhongxu; Wang, Zuobin; Changchun University of Science and Technology; et al. (Elsevier, 2020-08-17)
      Nature gives us a large number of inspirations in designing functional materials. Many plant leaves with self-cleaning properties are ubiquitous in nature. These plants have hierarchical structures, which have extreme repellency to liquids and have considerable technical potential in various applications. Herein, we present a method for fabricating bionic taro leaf surfaces by direct laser interference lithography (DLIL) and hydrothermal treatment. The micro-pillar array structure (MPA) was fabricated by DLIL, and a layer of nano-grass structure (NG) was grown on it by hydrothermal treatment. Experiments indicate that the hierarchical composite structures not only have a satisfactory superhydrophobic function with the apparent contact angle (CA) of 172° and sliding angle (SA) of 4°, but also have a strong anti-icing ability with the delay time (DT) of 3723 s. The method is simple and high-efficient for fabricating bionic self-cleaning and anti-icing surfaces.
    • Fabrication of hematite (α-Fe2O3) nanoparticles using electrochemical deposition

      Meng, Qing-Ling; Wang, Zuobin; Chai, Xiangyu; Weng, Zhankun; Ding, Ran; Dong, Litong; Changchun University of Science and Technology (Elsevier, 2016-02-04)
      In this work, cathodic electrochemical deposition was proposed to fabricate reproducible and homogeneous hematite (α-Fe 2 O 3 ) nanoparticles on indium-tin-oxide (ITO) films. The α-Fe 2 O 3 nanoparticles, which were quasi-hexagonally shaped, were deposited in an aqueous mixture of FeCl 2 and FeCl 3 at the temperatures 16.5 °C, 40 °C and 60 °C. The electrochemically deposited α-Fe 2 O 3 nanoparticles showed excellent stability and good crystallinity. The α-Fe 2 O 3 nanoparticles were characterized by Raman spectroscope and X-ray diffractometer (XRD). A scanning electron microscope (SEM) was used to measure the size and shape of the nanoparticles. The experiment results have shown that the size and shape of nanoparticles were determined by electrochemical deposition conditions including the deposition time, current density, reaction temperature and solution concentration. The proposed electrochemical deposition method has been proven to be a cost-effective, environment friendly and highly efficient approach in fabricating well decentralized α-Fe 2 O 3 nanoparticles for different potential applications.
    • Fabrication of hierarchical moth-eye structures with durable superhydrophobic property for ultrabroadband visual and mid-infrared applications

      Dong, Litong; Zhang, Ziang; Wang, Lu; Weng, Zhankun; Ouyang, Mingzhao; Fu, Yuegang; Wang, Jiake; Li, Dayou; Wang, Zuobin; Changchun University of Science and Technology; et al. (Optical Society of America, 2019-08-20)
      Multifunctional antireflective coatings have practical applications as important optical components in many fields, particularly for optical devices and imaging systems. However, a good antireflection application in the visible region is often unsatisfactory for mid-infrared devices, and the difficulty in obtaining multiple capabilities simultaneously is one of the main factors limiting their applications. In this work, hierarchical moth-eye structures with superhydrophobicity were fabricated via inductively coupled plasma reactive ion etching (ICP-RIE) using nanodisk-array masks, which were formed by three-beam laser interference lithography (LIL), for improving the ultra-broadband optical properties. The uniform antireflection efficiency, which was close to 1% reflectivity covering over the visible and mid-infrared wavelength range, was exhibited by the moth-eye structures with high-quality pillar arrays. Additionally, irregular nanostructures were tailored onto the top of the pillars to generate hierarchical moth-eye structures for simultaneously obtaining both the superhydrophobic and anticorrosive properties. The fabricated antireflective structures, with the features of self-cleaning and durability, have the advantage of being for long-term use in harsh environments.
    • Fabrication of moth-eye structures on silicon by direct six-beam laser interference lithography

      Xu, Jia; Wang, Zuobin; Zhang, Ziang; Wang, Dapeng; Weng, Zhankun; Changchun University of Science and Technology; University of Bedfordshire (American Institute of Physics Inc., 2014-05-22)
      This paper presents a new method for the generation of cross-scale laser interference patterns and the fabrication of moth-eye structures on silicon. In the method, moth-eye structures were produced on a surface of silicon wafer using direct six-beam laser interference lithography to improve the antireflection performance of the material surface. The periodic dot arrays of the moth-eye structures were formed due to the ablation of the irradiance distribution of interference patterns on the wafer surface. The shape, size, and distribution of the moth-eye structures can be adjusted by controlling the wavelength, incidence angles, and exposure doses in a direct six-beam laser interference lithography setup. The theoretical and experimental results have shown that direct six-beam laser interference lithography can provide a way to fabricate cross-scale moth-eye structures for antireflection applications. © 2014 AIP Publishing LLC.
    • Fabrication of Pt nanowires with a diffraction-unlimited feature size by high-threshold lithography

      Li, Li; Wang, Zuobin; Li, Wenjun; Peng, Kuiqing; Zhang, Ziang; Yu, Miao; Song, Zhengxun; Weng, Zhankun; Wang, Dapeng; Zhao, Le; et al. (American Institute of Physics Inc., 2015-09-29)
      Although the nanoscale world can already be observed at a diffraction-unlimited resolution using far-field optical microscopy, to make the step from microscopy to lithography still requires a suitable photoresist material system. In this letter, we consider the threshold to be a region with a width characterized by the extreme feature size obtained using a Gaussian beam spot. By narrowing such a region through improvement of the threshold sensitization to intensity in a high-threshold material system, the minimal feature size becomes smaller. By using platinum as the negative photoresist, we demonstrate that high-threshold lithography can be used to fabricate nanowire arrays with a scalable resolution along the axial direction of the linewidth from the micro- to the nanoscale using a nanosecond-pulsed laser source with a wavelength λ0 = 1064 nm. The minimal feature size is only several nanometers (sub λ0/100). Compared with conventional polymer resist lithography, the advantages of high-threshold lithography are sharper pinpoints of laser intensity triggering the threshold response and also higher robustness allowing for large area exposure by a less-expensive nanosecond-pulsed laser.
    • Fabrication of silicon nanostripe structures by laser-interference-induced backward transfer technique

      Wang, Zuobin; Jiang, Xuke; Weng, Zhankun; Cao, Liang; Zhang, Qinhan; Liu, Ri; Li, Li; Chu, Xueying; Xu, Hongmei; Song, Zhengxun; et al. (Elsevier, 2019-05-29)
      The laser-interference-induced backward transfer (LIIBT) that occurred during the nanostripe structuring of materials, performed by two-beam laser interference at the ITO glass/silicon wafer system under a normal atmospheric environment. The results showed that the nanostripe structures with nanoparticles (NPs) can be obtained at the laser fluence of 65–95 mJ·cm−2 for the laser duration of 100 and 200 pulses, respectively. The EDX analysis revealed that the silicon element was transferred on the surface of the nanostripe structures. In addition, Raman spectra with the peaks at ~520 cm−1 verified that the crystalline silicon was deposited on the nanostripe structures during the LIIBT process. Furthermore, the photoluminescence (PL) spectrum with the peak at ~395 nm belongs to the In2O3 nanostructure at the laser fluence of 45 mJ·cm−2 for 200 pulses. The peak at ~405 nm corresponds to the silicon nanostructures and it is covered by SiO at the laser fluence of 75 mJ·cm−2 for 200 pulses. The LIIBT shown here would greatly reduce the complexity in the fabrication of the nanostripe structures and give an impetus to the laser-induced backward transfer.
    • Fabrication of three-dimensional Si-Au hierarchical nanostructures by laser interference lithography

      Dong, Litong; Wang, Lu; Liu, Mengnan; Yu, Miao; Wang, Zuobin; Zhang, Ziang; Li, Dayou; Changchun University of Science and Technology; University of Bedfordshire (Institute of Electrical and Electronics Engineers Inc., 2018-11-29)
      This paper reports a method for the fabrication of 3D Si-Au hierarchical nanostructures to improve the optical performances through four-beam laser interference lithography (LIL) and inductively coupled plasma (ICP) etching. The 3D Si-Au hierarchical nanostructures were composed of silicon tapered pillar arrays, Au grids, and Au islands, and they demonstrated wide-angle antireflective properties less than 25% reflection in the entire visible wavelengths. In addition, many special properties could be obtained by displacing the islands and grid of the hierarchical structure with other metal material due to the flexibility of LIL and ICP etching.
    • Fabrication of TiO2 nanowire arrays using laser interference lithography aided hydrothermal method

      Ning, Xiao-Hui; Meng, Qing-Ling; Li, Li; Han, Yong-Lu; Zhou, Dong-Yang; Cao, Liang; Weng, Zhankun; Ding, Ran; Wang, Zuobin; Changchun University of Science and Technology; et al. (IEEE, 2018-02-08)
      Titanium dioxide (TÍO 2 ) is one of the most widely investigated semiconductor materials because of its unique properties. TiO 2 nanowire arrays can be synthesized through a two-step method, the fluorine-doped tin oxide (FTO) substrates were ablated using laser interference lithography technology, and TiO 2 nanowire arrays grown on the patterned FTO substrates. The TiO 2 nanowire arrays were characterized by SEM and XRD measurements. This work provides a high efficient method for the fabrication of ordered TiO 2 nanowire arrays for different applications in highly functionalized assemblies and composites.
    • A fair reconstruction method of hull surface

      Dong, Feng; Chen, Shunhuai (Editorial Board of Journal of Harbin Engineering, 2016-02-25)
      In order to use more accurate and fair hull model in ship CAD/CAM/CAE system, based on the hull offset data, the NURBS representation of the conventional station ordinates and generalized station ordinates are obtained by interpolation or approximation method. After obtaining these curves, the same number of data points is sampled from these curves by dividing its arc length equally, so as to form generalized offset points. By interpolation of these generalized offset points, compatible conventional station ordinates and generalized station ordinates are reconstructed, and these curves together constitute the cross-section curves of the hull surface. These cross-section curves are taken as u-direction isoparametric curves of hull surface. By using improved surface lofting method, the whole hull surface is gotten. From the results, it can be seen that the reconstructed hull surface has good fitting accuracy and fairness.
    • Fast Fourier transport analysis of surface structures fabricated by laser interference lithography

      Liu, Mengnan; Dong, Litong; Zhang, Ziang; Li, Li; Wang, Lu; Song, Zhengxun; Weng, Zhankun; Han, Xueyan; Zhou, Linhua; Wang, Zuobin (The Japan Society of Applied Physics, 2019-08-14)
      This paper presents an FFT (fast Fourier transform) analytical method for the study of surface structures fabricated by laser interference lithography (LIL). In the work, the FFT analytical method combined with Gaussian fitting is used to determine the periods and pattern distributions of surface structures from frequency spectra. For LIL, the processing parameters of incident and azimuth angles can be obtained corresponding to the period and pattern distribution. This work facilitates the detection of micro- and nano-structures, the analysis of pattern distribution in engineering, and the processing error analysis of LIL.
    • Feature extraction with GMDH-type neural networks for EEG-based person identification

      Schetinin, Vitaly; Jakaite, Livija; Nyah, Ndifreke; Novakovic, Dusica; Krzanowski, Wojtek; University of Bedfordshire; University of Exeter (World Scientific Journals, 2018-01-26)
      The brain activity observed on EEG electrodes is influenced by volume conduction and functional connectivity of a person performing a task. When the task is a biometric test the EEG signals represent the unique “brain print”, which is defined by the functional connectivity that is represented by the interactions between electrodes, whilst the conduction components cause trivial correlations. Orthogonalization using autoregressive modeling minimizes the conduction components, and then the residuals are related to features correlated with the functional connectivity. However, the orthogonalization can be unreliable for high-dimensional EEG data. We have found that the dimensionality can be significantly reduced if the baselines required for estimating the residuals can be modeled by using relevant electrodes. In our approach, the required models are learnt by a Group Method of Data Handling (GMDH) algorithm which we have made capable of discovering reliable models from multidimensional EEG data. In our experiments on the EEG-MMI benchmark data which include 109 participants, the proposed method has correctly identified all the subjects and provided a statistically significant (p<0.01) improvement of the identification accuracy. The experiments have shown that the proposed GMDH method can learn new features from multi-electrode EEG data, which are capable to improve the accuracy of biometric identification.
    • Finger-drawn signature verification on touch devices using statistical anomaly detectors

      Al-Khafaji, Shawq S.; Al-Jarrah, Mudhafar M.; Amin, Saad; Feng, Xiaohua; University of Bedfordshire; Middle East University; Alkhawarizmi International College (Institute of Electrical and Electronics Engineers Inc., 2020-04-09)
      The use of behavioral biometrics in user authentication has recently moved to new security application areas, one of which is verifying finger-drawn signatures and PIN codes. This paper investigates the design of anomaly detectors and feature sets for graphic signature authentication on touch devices. The work involved a selection of raw data feature sets that are extracted from modern mobile devices, such as finger area, pressure, velocity, acceleration, gyroscope, timestamp and position coordinates. A set of computed authentication features are formulated, derived from the raw features. The proposed anomaly detector is based on the outlier method, using three versions of the Z-Score distance metric. The proposed feature sets and anomaly detectors are implemented as a data collection and dynamic authentication system on an Android tablet. Experimental work resulted in collecting a signature dataset that included genuine and forged signatures. The dataset was analyzed using the Equal-Error-Rate (EER) metric. The results for random forgery and skilled forgery showed that the Z-Score anomaly detector with 3.5 standard deviations distance from the mean produced the lowest error rates. The skilled forgery error rates were close to random forgery error rates, indicating that behavioral biometrics are the key factors in detecting forgeries, regardless of pre-knowledge of the signature's shape.
    • Flower-shaped TiO2 clusters for highly efficient photocatalysis

      Ning, Xiao-Hui; Meng, Qing-Ling; Han, Yong-Lu; Zhou, Dong-Yang; Li, Li; Cao, Liang; Weng, Zhankun; Ding, Ran; Wang, Zuobin; Changchun University of Science and Technology (Royal Society of Chemistry, 2017-07-12)
      Titanium dioxide (TiO2) is one of the most widely used semiconductors, with a variety of applications such as water purification, photovoltaic cells, cancer treatment, gas sensors and photocatalysis. Flower-shaped TiO2 clusters can be obtained on patterned fluorine-doped tin oxide (FTO) substrates with one- and two-dimensional (1D and 2D) grating patterns through a two-step process combining laser interference ablation technology with a hydrothermal method. The patterned TiO2 clusters exhibit enhanced photocatalytic degradation of rhodamine B (RhB) and good durability. This work provides a facile route toward the applications of TiO2 clusters in solar-driven clean energy and environmental technologies.
    • A forensic investigation of robot operating system

      Abeykoon, Iroshan; Feng, Xiaohua; Qiu, Renxi; University of Bedfordshire (Institute of Electrical and Electronics Engineers Inc., 2018-04-02)
      The robot operating system for robot which is still relatively new, is rapidly gaining robot manufacture industry market share with dozens of robots and drons either released or set to be released. In this paper we present the first methodology and toolset for acquisition and deep analysis of volatile physical memory from robot operating system devices. The article discusses some of the challenges in performing ros memory acquisition, discusses. For memory forensics we used Lime, volatility memory framework and DD command. The acquisition tool supports dump memory to either exterl drive or via the network.
    • A forensic investigation of the robot operating system

      Abeykoon, Iroshan; Feng, Xiaohua; University of Bedfordshire (Institute of Electrical and Electronics Engineers Inc., 2018-02-01)
      The Robot Operating System (ROS) is a framework that is mostly used in industrial applications such as automotive, healthcare and manufacturing and it is not immune from potential future hacking. By carrying out various types of cyber-attacks, hackers can disrupt the normal operation of a robot. It is easy to get control of communication between a robot and a human due to the open communication network after carrying out malicious attacks to jam the network. As a result, hackers can change commands which are sent by an operator to the robot, making usual activities impossible. For instance, in a case of ROS hacking, man-in-the-middle attacks, Trojans, backdoor attacks, and so on, can change the behaviour of robots to something completely different than expected.Therefore, forensic analysts require a specific method to forensically investigate ROS. This is a new area in the computer forensics field. Therefore, it is proposed to create an analytical framework to facilitate the forensic investigation of the Robot Operating System and methodologies and standards for acquiring related digital evidence using forensic tools. This study addresses a formalized and structured methodology that would assist the forensic investigation approach.This research will help to enhance the gathering, identification and preservation of evidence related to forensics investigations of the Robot Operating System. The forensic analysts could adapt the examination procedure of hacked ROS with a focused, crime-specific, forensics framework.
    • FSOS: a tool for recommending suitable operating systems to computer users

      Lath, Bal Ram; Liu, Haiming; University of Bedfordshire (IEEE, 2016-09-01)
      Operating system is essential to operate computers. Normally, computers come with preloaded operating systems. However, often the preloaded operating systems are not able to fulfill all requirements of users. The users sometimes need to change the operating system based on their needs. Although some comparative studies and tools are available on operating systems, there is still a lack of tools that provide independent and objective review and recommendation to help the users understand and select from all major operating systems. This paper propose a tool called FSOS, which analyses well-known operating systems used at domestic, commercial and industrial level and suggest suitable operating systems to the users as per their requirements.
    • Gender roles and the expression of driving anger among Ukrainian drivers

      Sullman, M.J.M.; Stephens, A.N.; Hill, Tetiana; (Wiley, 2016-03-10)
      The current study investigated the validity of the revised (25‐item) version of the driving anger expression inventory (DAX) on a novel sample of 385 drivers from Ukraine. The roles of sex and gender in relation to self‐reported aggressive tendencies were also examined. Confirmatory factor analysis supported the four‐factor structure of the DAX (adaptive/constructive expression; use of the vehicle to express anger; verbal aggressive expression; and personal physical aggressive expression), and the three aggressive factors were found to have positive relationships with trait anger and driving anger, while adaptive/constructive expression was negatively related to trait and driving anger. Drivers who reported recent near‐misses or loss of concentration scored higher on verbal aggressive expression. Those who had recently received a traffic ticket also reported higher levels of all three types of aggressive anger expression. Further, the presence of feminine traits, but not sex, predicted more adaptive/constructive behaviors and lower scores for verbal aggressive expression, personal physical aggressive expression, and total aggressive expression. However, masculine traits did not predict any of these factors. This research concludes that the revised DAX is a valid tool to measure the expression of driving anger and that the endorsement of feminine traits is related to less aggressive expression of driving anger.
    • Green communications: techniques and challenges

      Malik, Nabeel A.; Ur-Rehman, Masood; ; University of Bedfordshire (European Alliance for Innovation, 2017-10-04)
      Green technology has drawn a huge amount of attention with the development of the modern world. Similarly with the development in communication technology the industries and researchers are focusing to make this communication as green as possible. In cellular technology the evolution of 5G is the next step to fulfil the user demands and it will be available to the users in 2020. This will increase the energy consumption by which will result in excess emission of co2. In this paper different techniques for the green communication technology and some challenges are discussed. These techniques include device-to-device communication (D2D), massive Multiple-Input Multiple-Output (MIMO) systems, heterogeneous networks (HetNets) and Green Internet of Things (IoT).
    • Growing green with improved profit through reduced power consumption in LTE networks

      Kanwal, Kapil; Safdar, Ghazanfar Ali; University of Bedfordshire (Association for Computing Machinery, 2017-03-31)
      Long Term Evolution (LTE) is well known 4G technology which promises higher data rates. Due to advancements in smart phones and new applications, the user's data requirements have significantly increased. The data hungry users engage radio resources over long periods of time thus resulting into higher energy consumption by Base stations (BSs). Increased energy consumption due to higher data rates directly increases Operational Expenditure (OPEX) thereby ensuing economic and environmental benefits, i.e. profitability and Global Warming. This paper presents detailed performance analysis of our novel joint resources block switching off and bandwidth expansion based energy saving scheme. Our proposed scheme offers 29% energy saving thus results in to decreased CO2 emissions (approximately 1.12 tonnes/ BS) and reduced OPEX thereby enabling mobile vendors to have high profile in Growing Green and help them to improve both environmental and economic aspects. Vendors could enjoy increased profit and stay Green through usage of our energy saving scheme.