In this paper we present two algorithms for computing discrete logarithms. We also introduce theorems that facilitate computing discrete logarithms and show how we break the Diffie-Hellman protocol, which is considered to be very secure.
The article discusses the authors’ reflections on the existing system for detecting, identifying and monitoring contaminationused by the Armed Forces of the Republic of Poland. Due to increasing contamination threats, mainly resulting from the unprecedentedescalation of nuclear rhetoric by Russia, but also industrial sources, there is a pressing need for technical and organisational modificationsto the system in order to minimise human error, while at the same time ensuring the reliability of the data. The paper presentstechnical solutions for the automatic detection of contamination and proposes a basic operational procedure for the system during theexecution of tasks. The introduction of automated systems would greatly enhance the effectiveness of the Contamination Detection Systemin the Armed Forces of the Republic of Poland, as well as other civilian subsystems in the National Contamination Detection andAlert System, particularly at the tactical level. The benefits of these systems include the elimination of the need to expose personnel andspecialised equipment to contamination, as well as enhanced mobility.
This article examines the transmission of light through an optically anisotropic layer of liquid crystal confined by dielectricwalls. The emphasis is on flat-parallel layers of ordered nematic liquid crystal. It discusses selected electro-optical effects (TN, ECB) andthe conditions necessary to maximise light transmission while minimising reflection. Different optical stack configurations are analysed.The paper also addresses the optimisation of optical parameters for high-transmission transducers for various applications.
Compression is data processing aimed at reducing the amount of information (e.g., for archiving and transfer). There is lossyand lossless compression. Compression algorithms can be either general-purpose or designed for specific types of data (e.g., for sound– including FLAC – Free Lossless Audio Codec, psychoacoustic model + Huffman coding in MP3; image – e.g., DCT, fractal, waveletcompression, RLE, Deflate, LZW; video – e.g., DivX, Cinepak, Indeo; textures in games and programs (e.g., S3TC, NVIDIA NeuralTexture Compression), executable files (e.g., UCL). The most commonly used compression algorithm is Deflate (LZ77 + Huffmancoding) – it is lossless and general-purpose. Depending on the compression method, there are dictionary algorithms (e.g., LZ77, LZW,LZSS, LZMA, LZ4, BPE, Zstd, Brotli), entropic algorithms (e.g., arithmetic and Huffman coding), predictive algorithms (e.g., PPM),and other types (including RLE, delta encoding). Some of the compression algorithms are patented. Deflate as a standard should bereplaced by more efficient algorithms (e.g., Brotli, Zstd, LZMA). The importance of compression is growing due to the general trendtowards growth of data.
This paper presents the results of an analysis of the usability of the Infrared Atmospheric Sounding Interferometer (IASI) data as analternative source of data on the vertical distribution of meteorological elements such as temperature and dew point temperature. The analysiswas carried out on the basis of data obtained by the IASI device and the measurement results obtained by means of upper air soundingsconducted in Camborne, UK from August 1 through 10, 2024. The paper also presents methodology to determine the dew point temperatureusing information acquired by satellites. The tabulated radiosonde data were retrieved from the University of Wyoming data repository, whilethe satellite data acquired by the MetOp satellites were obtained directly from EUMETSAT (the European Organisation for the Exploitation ofMeteorological Satellites). The results were obtained by the IASI from the MetOp-B and MetOp-C satellites when both orbited over the locationof the aerological station in Camborne during the time the upper air soundings were performed. These soundings were used as referencedata during the assessment of the IASI results. Statistical parameters, root mean square error (RMSE) and mean absolute error (MAE), werecalculated separately for the values of air temperature and dew point temperature to validate the pseudosoundings data obtained from the IASI.The satellites were shown as an alternative source of data on the vertical distribution of meteorological elements. The provided descriptions arefocused on the use of the data for the meteorological support of aviation and military operations.
This article presents a comprehensive analysis of contemporary coatings applied to land vehicles from the perspective oftheir camouflage effectiveness in VIS/NIR, MWIR/LWIR, and 1-18 GHz ranges, as well as their mechanical and operational resistance.NATO standards (STANAG 2338) and national standards (MIL-DTL-53039/64159, NO-80-A200, TL 8010-0002), along with technicalspecifications of certified IRR-CARC paints (USA, Poland, Germany), are identified. Based on available tests and case studies, thelimitations of single coating layers (inability to simultaneously control optical, thermal, and radar signatures) are discussed, and theapplication of mobile multispectral coverings (Saab Barracuda MCS, Lubawa Miranda) as a hybrid solution is justified.
In this paper, a modified adaptive grayscale image segmentation method based on human psychovisual phenomena (VPS) isproposed. This method generates a binarization threshold for each pixel separately. Compared to the0classical VPS method, the use of apixel observation model in the form of concentric circles is proposed. In the final part of the paper, this method was applied to segmentpreprocessed FLIR (forward looking infra-red) images of maritime objects. The results obtained by this method were compared withthe segmentation results of the same images by the Otsu method using mathematical criteria. The study confirmed better segmentationperformance using the modified VPS method.
This article presents a literature review of methods for protecting steam turbine blade surfaces from wear in order to extendtheir service life. The analysis concludes that the main causes of blade damage are erosion-corrosion processes and the effect of elevatedtemperatures inside the turbine. Progressive wear reduces the efficiency and power output of the entire power unit. The most commonmethods used to protect blade surfaces from wear are: surface hardening, application of protective overlays, spraying of protective coatings,generation of layers by laser surfacing and shot peening of blade surfaces. The use of surface protection against wear extends theservice life of the turbine, reducing the cost and time-consuming repair work.
Simultaneous Localization and Mapping (SLAM) represents a key technology enabling autonomous navigation and precise mappingof environments, whether they are unknown or lack GNSS signals. This process integrates localization with mapping by utilizing datafrom various sensors, such as cameras, lidars, and inertial measurement units (IMU). Over the years, SLAM technology has evolved dynamically,addressing challenges related to sensor noise, computational complexity, and variable operational conditions. This paper providesa comprehensive review of SLAM methods, focusing on classical algorithms – such as EKF-SLAM, Graph-Based SLAM, and FastSLAM– as well as modern approaches, including Visual SLAM, LiDAR-SLAM, and systems that combine visual data with inertial measurements.It discusses various mapping strategies, from grid maps and feature-based maps to topological representations and 3D point clouds, whichare fundamental to autonomous systems. Furthermore, the paper highlights the applications of SLAM technology in robotics, autonomousvehicles, and drones, demonstrating its broad utility across different fields. Finally, it examines current challenges and future directions,offering researchers and practitioners valuable insights for further refining and implementing SLAM systems.
The identification and quantification of degradation products of organophosphorus chemical warfare agents (OP-CWAs)are critical for retrospective and forensic analysis or evidence proceedings. Due to their high polarity and low volatility, direct chromatographicanalysis of these hydrolysis products is often ineffective, necessitating derivatization to enhance analytical performance.This study focuses on optimizing the derivatization conditions of sarin, soman and VX hydrolysates – O–alkylmethylphosphonic acids(methylphosphonic (MPA), ethyl methylphosphonic (EMPA), isopropyl methylphosphonic (IMPA), and pinacolyl methylphosphonicacid (PMPA)) using two common reagents: BSTFA for silylation and TMSD for alkylation. For each method, the optimal reagent volumes,reaction times, and temperatures were determined, and the stability of the resulting derivatives was evaluated. All derivatizationreactions proceeded optimally at 80C. Derivatization with BSTFA required 75–120 min to reach optimal analytical signal, whilederivatization with TMSD required 105–135 min. The results confirm that both derivatization strategies are effective in producing thedesired derivatives, although BSTFA silylation proved to be more practical and operationally stable. The findings support the use of derivatizationto improve the detection of OP-CWA degradation products by GC-MS and contribute to the development of more efficientanalytical procedures in the context of chemical weapons.
The article deals with a topical issue, which is the elimination of contamination of sensitive equipment, and therefore notsusceptible to the process by ‘wet’ methods. The problem is extremely important, because it concerns equipment, apparatus and equipmentthat may be crucial to the success of the mission (operation). Contamination elimination is the only component of the DefenseAgainst Weapons of Mass Destruction (WMD) system in which the recovery of combat capability of people, equipment and technologyafter contamination takes place. It is important to realise that the process may not be fully effective, and that residual contaminationmay pose a significant threat to the lives of servicemen and force protection measures (ISOPS). The introduction of new equipmentand supplies will require a number of requirements as early as at the stage of concept development, development of tactical-technicalassumptions (requirements) and design assumptions. This will include materials, connections, encapsulation to determine the impact ofcontamination and, consequently, susceptibility to decontamination processes. The finished product should have a certificate of resistanceto CWs and susceptibility to contamination elimination processes. At present, there is no identification of equipment in the PolishArmed Forces like equipment is defined in NATO documents as Sensitive Equipment and contamination elimination technologies.
These days, difficult-to-treat bacterial infections are occurring with increasing frequency. Antibiotic drug resistance posesa serious challenge in both medical and military contexts, threatening the effectiveness of therapies and the ability to combat infectionsin extreme conditions. Nanobiotechnology methods, particularly metal nanoparticles, could be a potential solution due to their uniquebiological, chemical, and physical properties, as well as the potent antimicrobial activity they exhibit. The presented research aimed toproduce silver (AgNPs) and copper nanoparticles (CuNPs) by an environmentally friendly method without synthetic reducing agents(in contrast to classical methods of synthesizing nanoparticles) and to determine antimicrobial properties. For this purpose, the synthesisof silver and copper nanoparticles using coffee bean extract was carried out. Then the zeta potential and size distribution of theobtained nanoparticles were determined. The minimum inhibitory (MIC) and bactericidal or fungicidal concentrations (MBC/MFC)were determined on biological models (C. albicans, S. enterica, L. monocytogenes), the viability of microorganisms was analyzed, andthe number of colony-forming units was determined. The results show that silver nanoparticles have a more potent antimicrobial effect,which was confirmed in all the tests carried out, as well as exhibiting more excellent colloidal stability compared to copper nanoparticles.
Small satellites, here referred to as SmallSats, are revolutionizing how we approach space missions by providing cost-effective,flexible and innovative solutions to conduct space operations. Smart satellite formations, due to significant advancements in satellitetechnologies, improved mission resilience, and cost efficiency, as well as flexibility and scalability, became a promising solution fora wide range of current and future Space missions. In military domain, sensor-to-shooter satellites are providing disruptive militarytechnology, enabling rapid, precise, and flexible response capabilities. In this paper, it is asserted that, in the mid to long term, there is aneed to develop dual-use autonomous Polish capabilities in support of procured space assets operating in low Earth orbit, especially ataltitudes up to 800 km. Based on an analysis of trends in small satellites development and application as well as the advantages relatedto SmallSats formations, it is argued that these capability needs could be met by the use of smart SmallSats formations. Poland, as anemerging space nation, already has significant know-how, experience, expertise and Space heritage of hi-tech payloads to be used inbuilding effective SmallSats Space capabilities. The approach has already been implemented in R&D project PIAST (Polish ImAgingSaTellites) expected to achieve initial comprehensive Space capability. For a variety of reasons, autonomous launch capability for at leastthe smallest satellites is recommended. It is also recommended to further investigate if satellite carriers could be used as Mother Shipsprepositioned in specified orbits and loaded with different SmallSats to be deployed in task force formations as needed. It is proposedthat some important challenges, such as broadband inter-satellite communication, be overcome through the connectivity with NATOand EU Space infrastructures. Likewise, other problems could be solved or leveraged by the use of advanced NATO and EU Space assets,along with carefully selected commercial services.
The strength and durability of the adhesive joint are, among other factors, a function of the joint’s dimensions and the size ofthe adhesive layer acting as a connecting element. In practice, the thickness of the adhesive layer is the result of, i.a., the tolerance of thejoined elements. The main purpose of the article is to determine the initial deformation of a single-lap adhesive joint at the stage of fixingthe joint in the grips of the testing machine. The article considers various aspects of manufacturing specimens of a single-lap adhesivejoint, as well as the repeatability of the dimensions of the joined aluminum tabs. The effect of tab preparation technology on the overalldimensions of the joint is discussed. A statistical analysis of the dimensions of the aluminum tabs, as well as the length and the thicknessof the adhesive layer is presented. A device and technology for producing a single-lap adhesive joint with repeatable dimensions underlaboratory conditions, along with an example of this device’s application, are also presented. The final part of the paper presents tests ofthe initial deformation of a single-lap adhesive joint during alignment of the overlap axis. A specially designed fixture enabling such testsis described in detail. In the tests undertaken to determine the initial deformation of the joint and the change in the clamping force of themovable handle on the upper tab, it was shown that there is no permanent deformation at the stage of aligning the tabs.
In the paper, the viscosity and the electric, magnetic and acoustic properties of liquid crystals, especially nematics, are discussed.All these properties are very important for applications of liquid crystals, and all of them are anisotropic. In the last part of the paper, essentialinformation regarding the behaviour of mesogen mixtures is presented, with the emphasis on phenomena important for fundamentalstudies and applications. The paper is intended for students, PhD students and engineers interested in properties of liquid crystals.
Hydraulic systems are one of the most popular types of drives. They are mostly used in industry and mobile applications.Wherever high forces are required, such as in the machinery and power industry, transportation or emergency equipment, hydraulicsystems are utilized. One of the hydraulic system components facing energy management and power consumption issues is a hydraulicpressure amplifier. This device, using the switching control technique, generates high oil pressure which results in obtaining high forcewhen it is required. This paper covers hydraulic pressure amplifier work principles and introduces a method to determine the positionof the working piston in such devices. Based on the examination results, the position changing algorithm was implemented utilizing thegradient descent optimization method.
Modern military conflicts highlight the need for military equipment to be independent of GNSS and radio communications,which are vulnerable to interference and can reveal the position of troops. In military meteorology, GNSS enables measurementsof upper-level winds, which are crucial, among other things, for parachuting. However, there are alternative and GNSS-independenttheodolite methods of measuring upper winds that can be successfully used in military meteorological support. Theodolites, despitetheir precision, are vulnerable to damages that can affect the accuracy of measurements. The authors of the paper conducted research todetermine the acceptable instrumental errors of theodolites required for reliable measuring wind speed and direction according to theWorld Meteorological Organization (WMO) standards. The results indicate that for meteorological purposes, the maximum error ofcollimation and vertical circle index should not exceed 0,1.
Cemented carbides WC-Co are one of the basic tool materials. They constitute over half of the currently used tools intendedfor machining. The main advantages of WC-Co cemented carbides are their high hardness and abrasion resistance. The properties ofWC-Co sinters depend mainly on the content of the binding phase, the sintering method, and the grain size of the powder from whichthe sinters were made. The aim of the study was to produce WC-Co nanocomposites using U-FAST (Upgraded Field Assisted SinteringTechnology), as well as to examine the basic properties of WC-Co sinters: microstructure, hardness, and phase composition. In thesintering processes carried out, no additives affecting the reduction of grain growth were used. The obtained results were compared withsimilar sinters produced using SPS (Spark Plasma Sintering) technology.
This article addresses a very important and relevant issue of protecting the soldier on the modern battlefield. Military doctrinedocuments a lack information on individual soldier protection. However, literature reports suggest that intensive work is underway inresearch institutions. The design concept is based on integrating various devices (equipment and apparatus) by using the soldier’s bodyas a supporting platform. The goal of these changes is to significantly enhance the soldier’s integrated protection and information processingcapabilities, as well as situational awareness on the battlefield. Personal protective measures against contamination, including filtermasks, protective filter clothing, personal dosimetry instruments and means for immediate decontamination satisfy current tacticalrequirements. When enhanced with IT components, sensors detecting physiological factors and battlefield imaging systems, they complementthe soldier’s ballistic protection. An important issue is the handling of contaminated equipment, which, according to AEP 7,should be treated as sensitive equipment. This matter is of utmost importance as it involves equipment, devices and gear that could becrucial to the success of a mission (operation).
The implemented indoor navigation system underwent testing to evaluate its performance in various environmental conditions,both in the absence of UWB signal propagation disturbances and in the presence of such disturbances. These tests aimed toassess the accuracy of position and velocity estimation by the integrated INS/UWB system. The conducted studies confirmed that thesystem effectively estimates user position and velocity coordinates. Research results under conditions without UWB signal propagationdisturbances show that the system is capable of determining object position with a centimetre-level accuracy. However, even in the presenceof signal propagation disturbances, the accuracy remains at a very high level, with errors not exceeding several centimetres. As aresult, the estimated position determined by the INS/UWB system faithfully reflects the actual user movement paths indoors.
