• Nitin Kumar

      Articles written in Sadhana

    • Cold test of cylindrical open resonator for 42 GHz, 200 kW gyrotron

      Vivek Yadav Sudeep Sharan Hasina Khatun Nitin Kumar M K Alaria B Jha S C Deorani A K Sinha P K Jain

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      This paper presents experimental results for cold testing of a gyrotron open resonator. Experiments were carried out to measure resonant frequency and their particular quality factor for TE mode at the frequency 42 GHz. The perturbation technique was used to determine the axial, radial and azimuthal electric field profile for identification of TE031 mode at operating frequency 42 GHz. The good agreement between experimental results and theoretical studies was found. The results verify the design and fabrication of the specific gyrotron cavity.

    • Where am I? Creating spatial awareness in unmanned ground robots using SLAM: A survey

      Nitin Kumar Dhiman Dipti Deodhare Deepak Khemani

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      This paper presents a survey of Simultaneous Localization And Mapping (SLAM) algorithms for unmanned ground robots. SLAM is the process of creating a map of the environment, sometimes unknown a priori, while at the same time localizing the robot in the same map. The map could be one of different types i.e. metrical, topological, hybrid or semantic. In this paper, the classification of algorithms is done in three classes: (i) Metric map generating approaches, (ii) Qualitative map generating approaches, and (iii) Hybrid map generating approaches. SLAM algorithms for both static and dynamic environments have been surveyed. The algorithms in each class are further divided based on the techniques used. The survey in this paper presents the current state-of-the-art methods, including important landmark works reported in the literature.

    • Optimization of weld bead geometry of MS plate (Grade: IS 2062) in the context of welding: a comparative analysis of GRA and PCA–Taguchi approaches


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      In the last few decades, researchers proceeded their foot for analyzing the weld characteristic index of materials since the development of novel materials began tremendously. Presently, evaluation of the optimum synchronization among considered input factors for materials are even now surviving into ill-defined mode;soliciting novel mathematical models as well as robustly designed decision support systems that could effectively handle nonpartial information (experimental data). In the present reporting, multiobjective optimization dilemmas have been answered in metal inert gas (MIG) welding process using MS plate (Grade: IS 2062) specimen. The considered specimen was checked to harmonize the optimum setting between input factors, for example, welding current, open circuit voltage, and thickness of plate, with respect to obtaining prosperous weld strength as well as bead geometry quality characteristics, for example, tensile strength, bead width, reinforcement, penetration, and dilution. In the present research work, the Taguchi’s L9orthogonal array (OA) design was preferred to conduct the experiments on MS plate (Grade: IS 2062) specimens in the domain of MIG weldingprocess. Thereafter, the evaluated multiple objectives transformed into a single response via exploration of grey relation analysis (GRA) and principal component analysis (PCA) approaches to determine the optimum setting between input factors. Next, the outset of signal-to-noise ratio (S/N ratio) along with Analysis of variance (ANOVA) productively was utilized to determine the priority weights against the defined input factors (significant factor). The significant contribution of the present report was to propose a robustly designed decision support system that could assist the readers/researchers to resolve the discussed problems.

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