The Journal of Engineering
Volume 2018, Issue 5, May 2018
Volumes & issues:
Volume 2018, Issue 5
May 2018
Abnormal event detection based on cosparse reconstruction
- Author(s): Huahua Chen ; Jie Gai ; Song Zhang ; Chao Wang ; Chunsheng Guo ; Xueyi Ye ; Yu Lu
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 254 –256
- DOI: 10.1049/joe.2018.0093
- Type: Article
- + Show details - Hide details
-
p.
254
–256
(3)
A novel video abnormal event detection method based on cosparse reconstruction with local self-similarity constraint is proposed. For a given spatio-temporal patch which is represented by a feature vector using concatenated multi-scale histogram of optical flow, abnormal event detection is implemented by cosparse reconstruction with respect to an analysis dictionary learned from normal event set. To adapt to the diversity of normal events, feature space is partitioned into meaningful subspaces by clustering and cosparse sub-dictionary is learned from each cluster. Experimental results show that the proposed approach achieves competitive performance with the state-of-the-art methods.
Development of a generalised PV model in MATLAB/Simulink using datasheet values
- Author(s): Al-Motasem I. Aldaoudeyeh
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 257 –263
- DOI: 10.1049/joe.2017.0257
- Type: Article
- + Show details - Hide details
-
p.
257
–263
(7)
This study proposes an improved single-diode modelling approach for photovoltaic (PV) modules suitable for a broad range of the PV technologies available today, including modules based on tandem cell structures. After establishing the model (which has an overall of seven parameters), this study devises a methodology to estimate its parameters using Standard Test Conditions (STC) data, Nominal Operating Cell Temperature (NOCT) data, and temperature coefficient values as provided in most manufacturers’ datasheets. Simulation results and their comparison with a previous work show a very accurate prediction of critical points in the current-voltage characteristics curve. The precise prediction happens for both STC and NOCT conditions and the error in predicting maximum power point (MPP) lies within 1% limit, and the error in its corresponding voltage and current is almost always within 2% limit. Further, for both MPP and open-circuit voltage, the statistical variance around manufacturer measurements due to temperature changes is demonstrated to be low for five various module technologies.
High-power low-loss air-dielectric stripline Gysel divider/combiner for particle accelerator applications at 352 MHz
- Author(s): Long Hoang Duc ; Anh Nguyen Dinh The ; Duong Bach Gia ; Magnus Jobs ; Roger Ruber ; Dragos Dancila
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 264 –267
- DOI: 10.1049/joe.2017.0793
- Type: Article
- + Show details - Hide details
-
p.
264
–267
(4)
This study presents a new two-way Gysel combiner based on an air-dielectric stripline which allows to handle very high radio-frequency power levels with low-loss suitable for power combination in accelerator applications. The insertion loss of the combiner is 0.1 dB (2%). A thick stripline implementation allows improving the power capability in both continuous wave (CW) and pulsed operation. In addition, a mechanical tuner allows compensating for assembly and fabrication discrepancies. A methodology of designing the Gysel combiner as well as high-power measurements up to 22 kW in pulsed mode are presented. Simulations and measurements are in very good agreement.
DOA estimation for monostatic MIMO radar using enhanced sparse Bayesian learning
- Author(s): Fangqing Wen ; Dongmei Huang ; Ke Wang ; Lei Zhang
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 268 –273
- DOI: 10.1049/joe.2017.0872
- Type: Article
- + Show details - Hide details
-
p.
268
–273
(6)
This study discusses the problem of direction-of-arrival estimation (DOA) estimation for a monostatic multiple-input multiple-output (MIMO) radar system, and a novel sparse Bayesian learning (SBL) framework is presented. To lower the computational load, the matched array data is firstly compressed via reduced-dimension transformation. Then the problem of DOA estimation is linked to a sparse inverse problem. Finally, a forgotten factor-based root SBL algorithm is derived from hyperparameters learning, which can solve the off-grid problem by finding the roots of a polynomial. The proposed algorithm does not require the prior of the source number, and it can apply to the scenario with a small snapshot as well as coarse grid, thus it has a blind and robust characteristic. Numerical simulations verify the effectiveness of the proposed algorithm.
Local tentative bonding method to maintain alignment accuracy in bonding process using resin as an adhesive material
- Author(s): Masahiro Kondo ; Ryohei Komiyama ; Hidetoshi Miyashita ; Sang-Seok Lee
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 274 –278
- DOI: 10.1049/joe.2017.0801
- Type: Article
- + Show details - Hide details
-
p.
274
–278
(5)
The authors proposed a novel method to maintain the alignment accuracy in the wafer-bonding process, which uses a resin as an adhesive material. Recently, the resin has received attention as an adhesive material for wafer bonding in microelectromechanical system device fabrication because of its multiple advantageous material properties. However, because of its inherent material viscosity, the alignment accuracy cannot be easily maintained, particularly when two wafers are bonded with a thick resin after alignment. To solve this problem, they proposed a local tentative bonding method. After aligning the two wafers, they irradiated the adhesive resin layer between the wafers using a near-infrared (NIR) spotlight (wavelength = 1020 nm), which is transparent to Si wafers. Using several NIR irradiation spots aimed at the resin layer after aligning the wafers, the resin layer was bonded locally and tentatively, which was sufficiently secure to avoid wafer shifting in the subsequent process. The local tentative bonded areas acted as anchors, which held the wafers during the bonding process. They performed experiments to demonstrate the effectiveness of their method using resins, such as polyimide, benzocyclobutene and SU-8. Consequently, they achieved an alignment accuracy <5 µm, which is a significant improvement compared with the typical bonding results.
Enhancement techniques for abnormality detection using thermal image
- Author(s): Ushus S. Kumar and Natteri M. Sudharsan
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 279 –283
- DOI: 10.1049/joe.2017.0899
- Type: Article
- + Show details - Hide details
-
p.
279
–283
(5)
Digital thermal imaging is considered as a non-invasive diagnostic tool and a real-time monitoring technique for indicating the physiological changes of the underlying tissue from the superficial thermal signature. A thermal camera can detect temperature variations in the body, as low as 0.1°C. The observed colour pattern depends on the prevailing temperature of the target in a controlled environment. This colour-based thermal pattern is further processed for identifying abnormalities. This process of identification is done by applying various methods such as histogram equalisation, Otsu thresholding and morphologic function. These steps are applied to thermal images of a foot acquired from volunteers and abnormalities were identified. The identification process was based on a threshold obtained from the histogram and it was found to be in the range of 76–80.
Transoral robotic surgery advantages and disadvantages: a narrative review
- Author(s): Dialekti Athina Voutyrakou ; Athanasios Papanastasis ; Melkon Chatsikian ; Panagiotis Katrakazas ; Dimitrios Koutsouris
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 284 –295
- DOI: 10.1049/joe.2017.0409
- Type: Article
- + Show details - Hide details
-
p.
284
–295
(12)
Robots were used for the first time in surgery back in 1997. Since then abdominal surgeries ensued with robotic surgery ‘infiltrating’ urology, gynaecology, and thoracic surgery fields as well. Lately, robotic surgery methodologies found application in head and neck surgeries leading to the development of the transoral robotic surgery (TORS). So far TORS has improved work of surgeons dealing with the oropharynx, hypopharynx, larynx, nasopharynx, thyroid, parapharyngeal space and skull areas of the human body. However, with the introduction of such a new efficacious modality, new questions emerge regarding its integration. The purpose of this review is to provide a thorough analysis of the advantages and disadvantages of TORS according to methodologies that have already been applied, along with their economic aspects, surgery processes, benefits compared to conventional surgery techniques, clinical results and any research gaps. Results indicate that TORS technical advantages denote its quality and importance in the field of robotic surgery.
Implementation of maximum efficiency control for matrix-converter-based interior permanent magnet synchronous motor drive systems
- Author(s): Tian-Hua Liu ; Yi Chen ; Shao-Kai Tseng ; Meng-Jhe Wu
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 296 –303
- DOI: 10.1049/joe.2018.0120
- Type: Article
- + Show details - Hide details
-
p.
296
–303
(8)
An implementation of an online maximum efficiency control for matrix-converter-based interior permanent magnet synchronous motor drive systems is proposed. A simplified efficiency model of the drive system is established first; as a result, detailed models of the matrix-converter loss and motor loss are not required. Next, an algorithm that calculates the steepest ascent to maximum efficiency is proposed. By identifying the maximum efficiency operating point, the efficiency of the whole drive system can be significantly improved based on the simplified efficiency model. A digital signal processor TMS320LF2407A and a complex programmable logic device EMP570GT100C4 are used as a control centre to execute the phase commutation, closed-loop speed control method, current regulating method, and maximum efficiency control method. Experimental results can validate the theoretical analysis and demonstrate the feasibility and correctness of the proposed method.
Effect of wind units on market clearing price, transmission congestion and network reliability in transmission expansion planning
- Author(s): Majid Ajalli and Abolfazl Pirayesh
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 304 –315
- DOI: 10.1049/joe.2017.0909
- Type: Article
- + Show details - Hide details
-
p.
304
–315
(12)
In this study, a transmission expansion planning problem is studied considering the effects of wind units on transmission congestion and power system reliability in a uniform electricity market. Market clearing price (MCP) is determined based on the maximisation of social welfare. Also, the congestion cost of a transmission system is defined as the difference between the cost of power supply before market clearing disregarding the transmission system (dispatching cost) and the operation cost of generating wind units of power suppliers considering transmission lines limit (re-dispatching cost). Dispatching cost is calculated using economic load dispatch and the re-dispatching cost is determined using optimal power flow. Moreover, the effect of wind units on transmission network reliability is studied through the relationship between wind units and lines loading and coherence between lines loading and lines failure rate. In addition, the effects of wind generation on composite transmission and generation reliability is formulated via the relationship between wind units and MCP and considering this price in loss of load and load shedding cost of customers. The proposed model is applied to the IEEE reliability test system and the results are discussed.
Isolated soft-switched boost DC–DC converter with low-voltage stress and high step-up ratio
- Author(s): Subhendu Bikash Santra ; Kundan Kumar ; Srikanta Mohapatra ; Debashis Chatterjee
- Source: The Journal of Engineering, Volume 2018, Issue 5, p. 316 –322
- DOI: 10.1049/joe.2018.0072
- Type: Article
- + Show details - Hide details
-
p.
316
–322
(7)
This study presents a novel soft-switched isolated boost converter which can provide a high-step-up ratio and high efficiency with low-voltage stress for portable application as well as a photovoltaic-assisted converter system. A lossless active clamp snubber circuit helps in achieving zero-voltage-switching turn-off and zero-current-switching (ZCS) turn-on of the main switch and ZCS turn-off of diodes that reduce switching losses. An auxiliary switch with an energy recovery circuit helps to increase power conversion efficiency and reduces switching stress across the main switch. The proposed idea is simulation through computer-assisted software PSIM 9.1.1 and validated experimentally through a designed prototype 250 W direct current (DC)–DC converter.
Most viewed content
Most cited content for this Journal
-
Towards good practice guidelines for the contour method of residual stress measurement
- Author(s): Foroogh Hosseinzadeh ; Jan Kowal ; Peter John Bouchard
- Type: Article
-
Mutual capacitor and its applications
- Author(s): Chun Li ; Jason Li ; Jieming Li
- Type: Article
-
Investigation of wound rotor induction machine vibration signal under stator electrical fault conditions
- Author(s): Sinisa Djurović ; Damian S. Vilchis-Rodriguez ; Alexander Charles Smith
- Type: Article
-
Techno-economic analysis of a PV–wind–battery–diesel standalone power system in a remote area
- Author(s): Temitope Adefarati ; Ramesh C. Bansal ; Jackson John Justo
- Type: Article
-
Survey of buffer management policies for delay tolerant networks
- Author(s): Sweta Jain and Meenu Chawla
- Type: Article