Security and Defence Quarterly最新文献

{"title":"CBAM-YOLOv5 for infrared image object detection","authors":"Viet Pham Hoang, Huong Ninh, Tran Tien Hai","doi":"10.1117/12.2640690","DOIUrl":"https://doi.org/10.1117/12.2640690","url":null,"abstract":"Identifying an object of interest in thermal images plays a vital role in several military and civilian applications. The deep learning approach has shown its superiority in object detection in various RGB datasets. However, regarding to thermal images, their low resolution and shortage of detail properties impose a huge challenge that hinders the accuracy. In this paper, we propose an improved version of YOLOv5 model to tackle this problem. Convolution Block Attention Module (CBAM) is integrated into traditional YOLOv5 for better representation of objects by focusing on important features and neglecting unnecessary ones. The Selective Kernel Network(SENet) is added to maximize the shallow features usage. Furthermore, the multiscale detection mechanism is utilized to improve small object detection accuracy. We train our model on the mixed visible-thermal images collected from LSOTB-TIR, LLVIP, and COCO datasets. We evaluate the performance of our method on 8 classes of objects: person, bicycle, airplane, helicopter, car, motorbike, boat, and tank. Experiment results show that our approach can achieve mAP up to 90.2%, which outperforms the original YOLOv5 and other popular methods.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"13 1","pages":"122760E - 122760E-12"},"PeriodicalIF":0.0,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85335315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence on the parameters of the optical resonator gyroscope of the characteristics of the system with the properties of parity-time-symmetry, which is used in it","authors":"Y. Filatov, E. Khorosheva, E. Shalymov, A. V. Venediktova, V. Venediktov","doi":"10.1117/12.2635919","DOIUrl":"https://doi.org/10.1117/12.2635919","url":null,"abstract":"A new type of optical resonator gyroscopes based on systems with parity-time-symmetry properties is considered. A system with parity-time-symmetry properties is composed of two direct coupled waveguides, one of which is characterized by losses, and the second one – by amplification, and a passive ring resonator connected to them. The influence of the characteristics of the parity-time-symmetry system on the optical resonator gyroscope parameters is investigated. Attention is paid to the influence of the gain, losses and coupling coefficients of the waveguides that make up the system with the parity-time-symmetry properties. The influence of the gain coefficient instability caused by a change in the pumping power on the angular velocity measurement results is also considered. The advantages and disadvantages of this approach are compared with a conventional optical resonator gyroscope. The main advantage of using systems with parity-timesymmetry properties is the increase of accuracy of registration of passive ring resonator eigenfrequencies by several orders of magnitude and, as a result, the maximum sensitivity to angular velocity.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"7 1","pages":"1227416 - 1227416-6"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75071827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Porcine skin as a surrogate for human skin in millimetre wave sensing research","authors":"A. Y. Owda, N. Salmon, M. Owda","doi":"10.1117/12.2635339","DOIUrl":"https://doi.org/10.1117/12.2635339","url":null,"abstract":"Improving the security screening requires good knowledge and understanding of human skin signatures. Our previous publications indicate that the signature of the human skin varies from person to person under a dry and wet state. Human skin is a very sensitive organ and not all material can be applied or attached directly to the skin. Therefore, it is an essential requirement to find a close surrogate i.e. (animal tissue) and characterise similarities in signature between human and animal skin. The importance of this is that it will allow us to investigate more easily signatures of the human skin under different materials and conditions. This paper investigates signatures for the human skin and ex-vivo porcine skin samples using the 90 GHz calibrated radiometer. The paper aims to compare and show similarities and differences in the signature between human and ex-vivo porcine skin samples for the first time using millimetric wave radiometry. To this end, water and different types of cream were applied to the palm of the hand and porcine skin samples namely: skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream. The reflectance of the skin was measured before and after the application, with and without the presence of a clothing layer. Reflectance measurements on human skin were applied on six participants in the palm of the hand region for comparison with reflectance measurements of porcine skin from six samples taken from the back region of different animals. Reflectance measurements for the palm of the hand skin show that the mean reflectance values for all six participants are: 0.458, 0.618, 0.578, 0.548, and 0.488 for normal skin, skin with water, skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream respectively. For porcine skin samples, the mean reflectance values for all six samples are: 0.438, 0.608, 0.598, 0.558, and 0.508 for normal skin, skin with water, skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream respectively. These measurements indicate the similarities between the palm of the human hand and the back region of swine. The measurements also show that the difference in the mean reflectance values between the palm of the hand region and porcine skin for all cases is ~0.02. After adding a clothing layer made of textiles on the palm of the hand skin and porcine skin samples; the reflectance measurements for the palm of the hand skin become 0.408, 0.545, 0.498, 0.488, and 0.458 for normal skin, skin with water, skin with water jel, skin with silver sulfadiazine cream, and skin with betadine cream respectively. For porcine skin samples the mean reflectance values are: 0.388, 0.518, 0.488,0.488, and 0.478 respectively. These measurements indicate that textiles are relatively transparent over the frequency band (80-100) GHz and the signature of the skin can be observed through clothing. The increased understanding of these measurements b","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"25 1","pages":"122740W - 122740W-9"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87890829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An image feature-based approach to improving SPAD flash LiDAR imaging through fog","authors":"Joyce Mau, J. Trumpf, Geoffrey Day, Dennis Delic","doi":"10.1117/12.2633941","DOIUrl":"https://doi.org/10.1117/12.2633941","url":null,"abstract":"Fog is a difficult medium to image through using Single-Photon Avalanche Diode (SPAD) based Light Detection and Ranging (LiDAR) systems because of its light scattering properties. Scattering significantly decreases the signal-to-noise ratio of photon returns, making it difficult to reconstruct meaningful images for target detection. In this paper, an image feature-based approach for reconstructing SPAD LiDAR images of a single target is proposed. Geometric characteristics of the target are used in the algorithm to differentiate between target and background photon returns. Combinations of different features such as Fourier shape descriptors and apparent target size are used to improve performance. To validate the algorithm, a 32×32 silicon SPAD array Flash LiDAR system operating at 532nm is used for collecting images through fog. Simple geometric shapes are placed indoors in a dark tunnel 44.6m from the sensor with fog decreasing the visibility in steps down to 12m. The proof-of-concept algorithm achieves good localization performance at a fog level of 1.4 attenuation lengths.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"33 1","pages":"1227406 - 1227406-10"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80810437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Security screening FDTD simulations of the human body and enclosures in polarimetric radar and comparison with measurements","authors":"D. Andrews, E. Blackhurst, N. Salmon","doi":"10.1117/12.2642650","DOIUrl":"https://doi.org/10.1117/12.2642650","url":null,"abstract":"Finite-difference time-domain simulations have been made of a security screening polarimetric radar over the band 18 GHz to 26 GHz, comparing the results with a proof-of-concept system operating over the same band. The proof-of-concept radar is presented together with its calibration and measurement set-up. Measurements indicate the cross-polarisation returns from a human subject are approximately 10 % to 25 % of the co-polarisation returns. A simulation model has been built using the openEMS software to simulate the body of a human, using realistic primitive shapes and electrical properties appropriate for these frequencies, indicating cross-polar returns are in the region of 15 % of the co-polar responses, with the duration of the reflections lasting around 2 ns. The comparisons between the measurements and simulations are good and provide a qualitative understanding of what happens when security screening radar radiation impinges on the human body. The simulation is extended to two simple enclosures, a cubic box and a short cylinder having dimensions of 300 mm and wall thicknesses of 5 mm, which could be made of wood, cardboard, paper or plastic. Results indicate the cross-polar reflection ranges from 3% to 75 % of the co-polar and bursts of reflections are commensurate with reflections from the front and back surfaces, these being separated in time by 2 ns.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"97 1","pages":"122740K - 122740K-7"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81749534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarization effect on dressed plasmonic waveguides","authors":"Kosala Herath, M. Premaratne","doi":"10.1117/12.2635710","DOIUrl":"https://doi.org/10.1117/12.2635710","url":null,"abstract":"We present the polarization effect on surface plasmonic polariton (SPP) modes in plasmonic waveguides under high-intensity radiation via the Floquet engineering methods. First, we analyze the strong light coupling to the metallic system using a nonperturbative procedure. Then, we describe the behavior of dressed metal fermion system using the Floquet state solutions. Furthermore, we examine the impurity scattering effects on electron transport in disordered plasmonic metals using the generalized Floquet-Fermi golden rule. We also show that we can reduce the SPP propagation losses in plasmonic metals by applying a dressing field. We introduce a new figure of merit to compare the performance of popular plasmonic metals, assessing their performance enhancements under two different polarization types of dressing fields. Our study can be applied to accurately interpret the usage of strong external radiation as a tool in quantum plasmonic circuits and devices.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"71 1","pages":"122740Q - 122740Q-15"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78997565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromagnetic imaging with atomic magnetometers: applications in security and surveillance","authors":"F. Renzoni","doi":"10.1117/12.2635309","DOIUrl":"https://doi.org/10.1117/12.2635309","url":null,"abstract":"We give an overview of our research programme on the use of atomic magnetometers to detect and image concealed conductive objects via electromagnetic induction. The extreme sensitivity of atomic magnetometers at low frequency, several orders of magnitude higher than a coil-based system of similar size, allows for their operation in such a frequency range, thus permitting deep penetration through different barriers. This overcomes the limitations usually associated with electromagnetic detection. Applications in security and surveillance are discussed.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"51 1","pages":"122740P - 122740P-5"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77376126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cavity exploration by laser pulse stretching measurements with single photon counting","authors":"F. Christnacher, Martin Laurenzis","doi":"10.1117/12.2638936","DOIUrl":"https://doi.org/10.1117/12.2638936","url":null,"abstract":"The recent development of single-photon avalanche diode (SPAD) based sensors has completely revolutionized the field of advanced imaging and contributed to the rapid increase of \"computational imaging\". In this paper, we show that it is possible to visualize the transient propagation wave when a laser pulse is entering into a cavity (e.g. an integrating sphere) though an opening, a skylight or any hole. The photon time-signature at the opening of the cavity depends on the volume or diameter of the cavity and on its spectral reflectance. By using ultra-short laser pulses, we demonstrated that the temporal observation of the reflected waves at such cavities can give a very fast information on the cavity volume and would allow to make a first evaluation before a more detailed analysis, for example with the NLOS technique. Our method of rapid cavity perimeter determination could be used in cavity assessment for disaster and damage scenarios and assistance for first responders, as well as for cavity exploration during geological/archaeological excavations or extraterrestrial missions to the Moon or Mars.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"250 1","pages":"1227409 - 1227409-9"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91321637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced visual perception through photon counting and computational imaging: what the time and number of photon events can tell us about the world around us","authors":"Martin Laurenzis, F. Christnacher","doi":"10.1117/12.2636434","DOIUrl":"https://doi.org/10.1117/12.2636434","url":null,"abstract":"Classical electro-optical (EO) sensing focuses on detecting light intensity and displaying it in grayscale images. Therefore, the development of EO systems was mainly concerned with the trade-off between resolution, signal-to- noise ratio, and image or data rate. In recent years, the development of silicon based single photon-counting avalanche diode (SPAD) detectors has initiated an almost unnoticed revolutionary development and paradigm shift in sensor technology. In contrast to intensity imaging, SPAD sensors are capable to sense a single photon event as a binary and noise free intensity. Furthermore, the occurrence of these photon events can be determined very precisely in time, allowing access to the sub-nanosecond or even picosecond time scale and application in precise distance measurement. Combined with computational imaging, i.e. linking the acquisition process to a strong mathematical model, it is possible to obtain information that was previously inaccessible and extend the perceptual range of EO sensors. In this paper, we provide an overview of various active and passive SPAD imaging techniques that are coupled with laser illumination or use ambient light. We focus on applications with relevance to military use. In detail, we summarize results in the areas of passive imaging, range finding and vision through scattering media, and advanced acquisition methods such as non-line-of-sight imaging.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"16 1","pages":"1227407 - 1227407-12"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84330987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Algorithm for increasing the discriminability of sections of vortex structures and wind flows recorded by radio frequency stations using Doppler effect analysis","authors":"E. Semenishchev, A. Zelensky, M. Zhdanova, N. Gapon, A. Gavlicky, V. Voronin","doi":"10.1117/12.2641156","DOIUrl":"https://doi.org/10.1117/12.2641156","url":null,"abstract":"The article proposes a fusion technique and an algorithm for combining images recorded in the IR and visible spectrum in relation to the problem of processing products by robotic complexes in dust and fog. Primary data processing is based on the use of a multi-criteria processing criterion with complex data analysis and cross-change of the filtration coefficient for different types of data. The search for base points is based on the application of the technique of reducing the range of clusters (image simplification) and searching for transition boundaries using the approach of determining the slope of the function in local areas. As test data used to evaluate the effectiveness, pairs of test images obtained by sensors with a resolution of 1024x768 (8-bit, color image, visible range) and 1024x768 (8 bit, color, IR image) are used. Images of simple shapes are used as analyzed objects.","PeriodicalId":52940,"journal":{"name":"Security and Defence Quarterly","volume":"10 1","pages":"122741B - 122741B-7"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77804930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}