Defence Science Journal最新文献_第4页

Technological Perspectives of Countering UAV Swarms 反无人机群的技术视角

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.18695

Ranjana Nallamalli, Kulwant Singh, Indra Deo Kumar

引用次数: 0

Selection of Combat Aircraft by Using Shannon Entropy and VIKOR Method 利用香农熵和 VIKOR 方法选择作战飞机

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.17996

P. Dwivedi, Dilip Kumar Sharma

{"title":"Selection of Combat Aircraft by Using Shannon Entropy and VIKOR Method","authors":"P. Dwivedi, Dilip Kumar Sharma","doi":"10.14429/dsj.73.17996","DOIUrl":"https://doi.org/10.14429/dsj.73.17996","url":null,"abstract":"The selection of military defense equipment, especially fighter aircraft, has a bearing on the readiness ofthe Indian Air Force to defend the country’s independence. This study analyses a collection of alternative fighteraircraft that are linked to several choice factors using a multiple-criterion decision-making analysis technique. Tohandle such scenarios and make wise design judgements, a variety of criterion decision analysis techniques can beused. In this study, we assess fifth-generation fighter aircraft that incorporate significant 21st-century technologicaladvancements. These aircraft represent the state-of-the-art in fleet planning operations to 2022. These are generallyequipped with quick-moving airframes, highly integrated computer systems, superior avionics features, networkingwith other battlefield elements, situational awareness, command, control, and other communication capabilities.The study proposes a strategy for the selection of the fifth-generation combat aircraft for the National Air Force.Because of the problems, the Army needed an application that could assist with decision-making for combat selection systems. Solving the decision problem for evaluating fifteen military fighter alternatives in terms of nine decision criteria is the main objective of this work. We use the Shannon entropy and VIKOR model for the Air Force’s fleet program to evaluate military fighter aircraft suitability. The entropy technique is used to compute the weight of the criteria, and then the VIKOR technique has been used to rank the fighter aircraft.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":"17 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139360264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental Investigation and Thermophysics Analysis of Joule Thomson Cooler Applicable to Infrared Imaging 适用于红外成像的焦耳-汤姆逊冷却器的实验研究与热物理分析

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.18686

Mayank Singhal, Rajesh Kumar, R. Walia, S. K. Pandey

引用次数: 0

Detection of Abnormal Vessel Behaviours Based on AIS Data Features Using HDBSCAN+ 利用 HDBSCAN+ 根据 AIS 数据特征检测异常船只行为

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.18626

R. H. Kumar, CP Ramanarayanan, K.S.R.R.P. Murthy

引用次数: 0

A Frequency Tunable Dielectric Resonator Antenna with Reduction of Cross Polarisation for Wi MAX and Sub 6 GHz 5G Applications 一种频率可调的介质谐振器天线，可减少交叉极化，适用于 Wi MAX 和 6GHz 以下 5G 应用

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.18180

Rajkishor Kumar, Avinash Chandra, N. Mishra, R. Chaudhary

{"title":"A Frequency Tunable Dielectric Resonator Antenna with Reduction of Cross Polarisation for Wi MAX and Sub 6 GHz 5G Applications","authors":"Rajkishor Kumar, Avinash Chandra, N. Mishra, R. Chaudhary","doi":"10.14429/dsj.73.18180","DOIUrl":"https://doi.org/10.14429/dsj.73.18180","url":null,"abstract":"A frequency Tunable (mechanical tuning) Linearly Polarized (TLP) rectangular Dielectric Resonator Antenna(DRA) coupled with a horizontal/vertical-slot and excited with circular-ring type feed is investigated in this article.The frequency tunability (mechanical tuning) is achieved by the rotation of slot at different angles of the proposedstructure. Hence, two linearly polarized antennas have been proposed for different frequency bands such as Wi-MAX and Sub-6 GHz/5G, respectively, using slot variations (named as DRA-1 and DRA-2). TE 11δ mode has been excited in both the DRAs and confirmed by orientation of electric field inside the rectangular DRA. The measured -10 dB input impedance bandwidths of DRA-1 offer 21.60 % being centered at 2.87 GHz and the separation of co-polarized and cross-polarized field levels is above -24 dB in the broadside direction (xz-plane). Whereas DRA-2 offers measured -10 dB input impedance bandwidths of 23.03% being centered at 3.56 GHz having a separation of co-polarized and cross-polarized field levels are above -23 dB in the broadside direction (xz-plane). In addition, the proposed DRA-1 and DRA-2 show a maximum gain of 5.23 dBi and 4.75 dBi in broadside direction, respectively.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":"100 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139360266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Localised Pressure Depression and Rain on Aerodynamic Characteristics of MALE UAV 局部气压下降和降雨对 MALE 无人机空气动力特性的影响

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.17481

M. Vijayakumar, Parammasivam K M, S. Rajagopal, C. Balaji

{"title":"Effect of Localised Pressure Depression and Rain on Aerodynamic Characteristics of MALE UAV","authors":"M. Vijayakumar, Parammasivam K M, S. Rajagopal, C. Balaji","doi":"10.14429/dsj.73.17481","DOIUrl":"https://doi.org/10.14429/dsj.73.17481","url":null,"abstract":"This paper presents the effect of the local low-pressure region in the atmosphere and rain on aerodynamiccharacteristics of medium altitude long endurance unmanned aerial vehicle (MALE-UAV) configuration duringcruise/loiter. Computations are performed using CFD++, a commercial CFD software suite. A large low-pressuredepression past the MALE UAV (symmetrically and asymmetrically) with pressure 10 – 15 % lower than the freestream pressure and a widespread rainfall type with a rainfall rate of 1195 mm/hr., are considered for CFD simulation.A large low pressure that spans the whole MALE-UAV results in a decrement in both lift and drag, but does not affect the yawing and rolling moments significantly. However, a low-pressure region that engulfs only one-half of MALE UAV causes sudden/abrupt changes in rolling and yawing moments. The effect of rain causes a significant decrease in a lift at higher alpha, accompanied by a decrease in stall angle of 2 degrees, and a significant increase in drag. From the study, a Standard Operating Procedure (SOP) was adopted to fly UAVs in adverse weather effects,such that the aircraft can be operated with a velocity higher than 1.3Vstall and at a power setting not less than 75% of max power capacity.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":"131 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139360567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Compact UWB Monopole Antenna with Tunable Dual Band Notched Characteristics for WiMAX and WLAN Applications 为 WiMAX 和 WLAN 应用提供具有可调双频缺口特性的紧凑型 UWB 单极天线

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.17885

Vikas Kumar Rai, Mithilesh Kumar

{"title":"Compact UWB Monopole Antenna with Tunable Dual Band Notched Characteristics for WiMAX and WLAN Applications","authors":"Vikas Kumar Rai, Mithilesh Kumar","doi":"10.14429/dsj.73.17885","DOIUrl":"https://doi.org/10.14429/dsj.73.17885","url":null,"abstract":"The present work shows a planar compact ultra-wideband (UWB) monopole antenna with controllable dualband-notch frequencies at 3.3 GHz for WiMAX and 5 GHz for WLAN. In the proposed antenna, the lower notchband (at a frequency of 3.3 GHz) is made by cutting a thin horizontal strip on top of the radiating patch. The uppernotch band (at a frequency of 5 GHz) is made by putting two narrow parasitic strips in the shape of an “I” oneither side of the radiating patch. The incorporation of three varactor diodes between the radiating patch and three metallic strips provides the flexibility of adjusting the notch frequencies. The notch band tunability between 3.15 GHz and 3.69 GHz and between 4.93 GHz and 5.59 GHz, respectively, is achieved by changing the bias voltageof the varactor diode between 0 V and 30 V. The gain and efficiency characteristics of the designed antenna alsoexhibit band rejection at the respective notch frequencies. The design principle is validated by fabricating andmeasuring a prototype of the proposed dual-band, notched UWB antenna. For three different bias voltages of thevaractor, the simulated and experimental findings are in reasonable agreement. The proposed works demonstratebetter-notch characteristics as compared with other reported works over the UWB range","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":"192 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139360323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of Cognitive Electronic Warfare System With Sine and Square Waves 利用正弦波和方波模拟认知电子战系统

IF 0.9 4区工程技术

Defence Science Journal Pub Date : 2023-07-11 DOI: 10.14429/dsj.73.18539

Krishna K Naik

{"title":"Simulation of Cognitive Electronic Warfare System With Sine and Square Waves","authors":"Krishna K Naik","doi":"10.14429/dsj.73.18539","DOIUrl":"https://doi.org/10.14429/dsj.73.18539","url":null,"abstract":"Today’s Electronic Warfare (EW) receivers need advanced technology to achieve real-time surveillance operations. Dynamic and intelligent systems are required for UAVs and other airborne applications. The airborne Electronic Warfare systems must be knowledge-based systems, learning from the threat scenario with highly integrated capabilities to detect, react, and adapt to radar threats in real-time. Artificial intelligence is a machine-dependent process, by adapting certain rules and logic supported by human intelligence, AI can be used for cognitive processing. Cognitive signal processing is required for making the system autonomous and dynamic in nature. Military action on radar signatures requires a set of commands to be executed dynamically with the help of the proposed EW system. It is proposed to design and develop a cognitive EW architecture and simulation of machine learning that combines neural network architecture with the help of sine and square waves as input. This paper presents the Cognitive signal processing for EW systems with Neural Network, Recurrent Neural Network (RNN), Machine learning (ML), and Deep learning (DL) techniques with their simulation with sine and square waves.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":"5 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139360598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Digital Twin Framework for Lathe Tool Condition Monitoring in Machining of Aluminium 5052 铝5052加工中车床刀具状态监测的数字孪生框架

4区工程技术

Defence Science Journal Pub Date : 2023-05-12 DOI: 10.14429/dsj.73.18650

S. Ganeshkumar, Bipin Kumar Singh, R. Suresh Kumar, Anandakumar Haldorai

{"title":"Digital Twin Framework for Lathe Tool Condition Monitoring in Machining of Aluminium 5052","authors":"S. Ganeshkumar, Bipin Kumar Singh, R. Suresh Kumar, Anandakumar Haldorai","doi":"10.14429/dsj.73.18650","DOIUrl":"https://doi.org/10.14429/dsj.73.18650","url":null,"abstract":"   Digital Twin (DT) is a virtual representation of a product system that exhibits the properties and analyzes the system’s functions. The significant impact of DT extends to several fields, which increases productivity and reduces wastage. This article focuses on developing a Digital twin model of a Lathe machine for Tool Condition Monitoring (TCM). DT implementation in industries is challenging due to simulating online cutting forces and wear. Even though several pieces of research have been carried out in the prediction of tool conditions using machine learning, Artificial Neural network models, only a few pieces of research have been made in digital twins for TCM. This article provides the technique for implementing the DT model of a lathe tool. The feasibility of the DT Model framework is verified by a case study of the turning process with a CNC Lathe machine while machining of Aluminium 5052 workpiece using Titanium Nitride coated tool inserts. The sensor’s data are acquired and fed to the microcontroller for real-time data acquisition. The real-time dataset is processed in the DT model for monitoring and predicting the tool conditions. The tool wear classification using the DT model is achieved. Developing the Digital Twin model in machining increases productivity and assists in predictive maintenance.  ","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135421318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design and Verification of Carefree Maneuvering Protection for a High Performance Fighter Aircraft 高性能战斗机自由机动防护设计与验证

4区工程技术

Defence Science Journal Pub Date : 2023-05-12 DOI: 10.14429/dsj.73.18402

S.K. Jebakumar, Abhay A. Pashilkar, N. Sundararajan

{"title":"Design and Verification of Carefree Maneuvering Protection for a High Performance Fighter Aircraft","authors":"S.K. Jebakumar, Abhay A. Pashilkar, N. Sundararajan","doi":"10.14429/dsj.73.18402","DOIUrl":"https://doi.org/10.14429/dsj.73.18402","url":null,"abstract":"Flight envelope protection for a high-performance aircraft poses a challenge to the designers and involves a time-consuming procedure to verify the provided protection. This paper presents a design approach to protect the aircraft from departure by a command path limiter for a rate command attitude hold controller in both the pitch and roll axes. In this approach, the maximum and minimum rates are scheduled as a function of the dynamic pressure on the basis of the open loop aircraft capabilities. This is then augmented with a novel angle of attack protection that comes into play only when the pilot inputs cause the aircraft to exceed the incidence on the positive or negative side (one sided protection), while maintaining the rate command attitude hold behavior within the normal operational bounds of angle of attack. Traditional methods of piloted simulation with a representative cohort of pilots can be time consuming to set up and may not give sufficient confidence whether a departure protection scheme is effective. To address this, a unique multi-modal search using genetic algorithm is developed to verify that this command path protection is able to achieve carefree maneuvering of a fighter aircraft in its entire flight envelope. The sequence of rapid pilot control inputs is coded into a chromosome. The multi-modal genetic algorithm then uses operators like cross-over and mutation on a starting population of chromosomes to evolve new inputs sequences which are then run to obtain the aircraft response. The cost function of the genetic algorithm which is constructed from the aircraft time response is designed to favor the search for multiple maxima which drive the aircraft to departure. The open domain ADMIRE model has been used to demonstrate the approach. Results indicate that the command path design proposed in this paper can be used to protect against departure and the novel multi-modal genetic algorithm helps to verify the departure protection.","PeriodicalId":11043,"journal":{"name":"Defence Science Journal","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135421317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0