LNM Institute of Information Technology

Ibeh L., Kouveliotis K., Unune D.R., Cuong N.M., Mutai N., Fountis A., Samoylenko S., Pattanaik P., Kumari S., Sambiri B.B., Mohamud S., Baskakova A.

Resource conflicts constitute a major global issue in areas rich in natural resources. The modeling of factors influencing natural resource conflicts (NRCs), including environmental, health, socio-economic, political, and legal aspects, presents a significant challenge compounded by inadequate data. Quantitative research frequently emphasizes large-scale conflicts. This study presents a novel multilevel approach, SEFLAME-CM—Spatially Explicit Fuzzy Logic-Adapted Model for Conflict Management—for advancing understanding of the relationship between NRCs and drivers under territorial and rebel-based typologies at a community level. SEFLAME-CM is hypothesized to yield a more robust positive correlation between the risk of NRCs and the interacting conflict drivers, provided that the conflict drivers and input variables remain the same. Local knowledge from stakeholders is integrated into spatial decision-making tools to advance sustainable peace initiatives. We compared our model with spatial multi-criteria evaluation for conflict management (SMCE-CM) and spatial statistics. The results from the Moran’s I scatter plots of the overall conflicts of the SEFLAME-CM and SMCE-CM models exhibit substantial values of 0.99 and 0.98, respectively. Territorial resource violence due to environmental drivers increases coast-wards, more than that stemming from rebellion. Weighing fuzzy rules and conflict drivers enables equal comparison. Environmental variables, including proximity to arable land, mangrove ecosystems, polluted water, and oil infrastructures are key factors in NRCs. Conversely, socio-economic and political factors seem to be of lesser importance, contradicting prior research conclusions. In Third World nations, local communities emphasize food security and access to environmental services over local political matters amid competition for resources. The synergistic integration of fuzzy logic analysis and community perception to address sustainable peace while simultaneously connecting environmental and socio-economic factors is SEFLAME-CM’s contribution. This underscores the importance of a holistic approach to resource conflicts in communities and the dissemination of knowledge among specialists and local stakeholders in the sustainable management of resource disputes. The findings can inform national policies and international efforts in addressing the intricate underlying challenges while emphasizing the knowledge and needs of impacted communities. SEFLAME-CM, with improvements, proficiently illustrates the capacity to model intricate real-world issues.

Dahiya H., Suthar R., Karak S., Sharma G.D.

Yadav R., Gotra S., Pandey V.S., Sharma A.K., Verma P.

Gopalakrishna S., Tibrewala R.

We compute the baryon asymmetry in decay and scattering processes involving the electromagnetically charge-neutral fermion χ that carries the nonzero baryon number and interacts with quarklike fermions U, D via a vector-vector dimension-six effective operator, in the theory we developed in our earlier work. Majorana masses for the χ break the baryon number and split the Dirac fermion χ into a pair of Majorana fermions Xn with an indefinite baryon number. We identify loop amplitudes for Xn decay and scattering processes that are sensitive to the baryon number violation. The phases in the Majorana mass and couplings, in conjunction with the phase from intermediate on-shell states, lead to C and CP violation in these processes. For some representative parameter choices, we numerically compute the decay and scattering baryon asymmetries between the process and its conjugate process and find that the asymmetry generated is very interesting for explaining the baryon asymmetry of the Universe. Published by the American Physical Society 2025

Caballero R., de la Cruz P., Langa F., Singhal R., Sharma G.D.

AbstractA donor‐acceptor‐donor (D−A−D) molecule, denoted as RC18, consisting of two nickel‐porphyrin terminal donor units (D) and a selenophene‐flanked diketopyrrolopyrrole central core, connected via an ethynylene linker has been synthesized. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels were measured showing values of −5.49 eV and −3.75 eV, respectively. We have utilized RC18 as donor along with two acceptors, DICTF and Y6, for OSCs and found that power conversion efficiencies were 12.10 % and 12.59 % for RC18:DICTF and RC18:Y6, respectively. The complementary absorption profiles of RC18, DICTF and Y6, along with the intermediate LUMO level of DICTF between RC18 and Y6, led to the fabrication of ternary organic solar cells. RC18:DICTF:Y6 based ternary attained power conversion efficiency of 16.06 %. The observed enhancement in the PCE is attributed to efficient exciton utilization through energy transfer from DICTF to Y6, increased donor‐acceptor interfacial area, suppressed charge carrier recombination and improved molecular ordering. These all factors contribute to improvements in short‐circuit current density (JSC) and fill factor (FF). Additionally, the open‐circuit voltage (VOC) of the ternary OSC lies between those of the two binary OSCs indicating the formation of an alloy between the two acceptors.

Thorbole S., Raj R., Upadhyay N.

In real-world scenarios, speech signals are often corrupted by various types of noise, which can significantly degrade the intelligibility and quality of the speech. Noise in such environments is highly non-stationary, changing rapidly and unpredictably. A new algorithm has been created to estimate noise in speech signals affected by rapidly changing and unpredictable non-stationary noise. This algorithm aims to enhance speech quality and intelligibility in challenging acoustic settings. It determines signal presence by comparing the power spectrum of noisy speech to a continually updated local minimum, calculated from past noisy speech power spectra with a look-ahead factor. Its standout feature is its rapid adaptability to swiftly respond to new noise patterns, crucial for maintaining speech clarity and quality in dynamic noise environments. Formal experiments validated its effectiveness compared to other noise-estimation methods when integrated into speech enhancement systems, using metrics like mean squared error (MSE) and signal to noise ratio (SNR). This algorithm significantly contributes to noise estimation and voice enhancement, offering effectiveness in handling highly non-stationary noise and being adaptable and versatile for various applications. This algorithm stands as a substantial advancement in the domains of noise estimation and voice enhancement overall. Its utility extends across diverse applications owing to its proficiency in handling highly non-stationary noise conditions, coupled with its adaptability and versatility.

Bhuyan N.N., Shankar S S., Bhoi M., Dahiya H., Singhal R., Sharma G.D., Mishra A.

Panda B.S., Joshi S., Jacob D.

A set $$D \subseteq V$$ of vertices of a graph $$G=(V,E)$$ is called a dominating set of G if for every vertex $$u \in V\setminus D$$ , there exists a vertex $$ v \in D$$ such that $$ uv \in E(G)$$ . A dominating set D is called a bipartite dominating set if G[D], the subgraph induced by D, is bipartite. The domination number of G is the minimum cardinality among all dominating sets of G and it is denoted by $$ \gamma (G)$$ . The bipartite domination number of G is the minimum cardinality among all bipartite dominating sets of G and it is denoted by $$ \gamma _{bip}(G)$$ . The Min Dom problem is to find a dominating set of minimum cardinality of a given graph G and Decide Dom is the decision version of the Min Dom problem. Similarly, the Min Bip-Dom problem is to find a bipartite dominating set of minimum cardinality of a given graph G and Decide Bip-Dom is the decision version of the Min Bip-Dom problem. In this paper, we initiate the algorithmic study of the Min Bip-Dom problem. First, we study the complexity difference between the Min Dom problem and the Min Bip-Dom problem. The difference between $$\gamma _{bip}(G)$$ and $$\gamma (G)$$ of a graph G can be arbitrarily large. However, the Decide Bip-Dom problem is the same as the Decide Dom problem for bipartite graphs and hence is NP-complete for bipartite graphs, as Decide Dom problem is known to be NP-complete for bipartite graphs. We show that Decide Bip-Dom is NP-complete for non-bipartite graphs as well. Finally, we propose polynomial-time algorithms for the Min Bip-Dom problem for interval graphs and block graphs.

Sain M., Laskar R., Singha J., Saini S.

Human Activity Recognition (HAR) systems play a crucial role in healthcare applications, yet their performance is often hindered by challenges such as illumination variation, occlusion, and view variation. This research addresses the view variation problem by proposing an innovative model that combines three methodologies to enhance accuracy and robustness in the recognition of patient activities. The model integrates motion history images, trajectory-based representations from both wrists (converted into 2D plots with Gaussian smoothing) and novel hand kinematic features, addressing view-related challenges by focusing on view-invariant characteristics alongside traditional joint motion features. The model is rigorously evaluated on a newly curated dataset, LNMIIT-MVAD( LNMIIT-Multiview activity dataset), showcasing its effectiveness in capturing diverse patient activities. Validation on the NTU-RGBD120 (Nanyang Technological University RGBD 120 dataset), NTU-Fall (Nanyang Technological University fall dataset), and KTH datasets highlights the model’s adaptability to different datasets. The fusion of outputs from the three methodologies through majority voting ensures a comprehensive and reliable recognition system. This research contributes to overcoming the limitations of traditional HAR systems, specifically addressing the challenge of view variation, and demonstrates promising results for real-world applications in patient care and monitoring. The proposed methodology and architecture achieved remarkable precision on various datasets: 97. 14% on LNMIIT-MVAD, 94. 28% on NTU-RGBD120, 95. 71% on KTH and 91. 14% on NTU-Fall.

Babulal M.S., Gauttam S.K., Maheshwari A.

В статье изучается процесс Леви с независимыми от него заменами времени, при этом в качестве замены времени выступают субординаторы Леви, а именно неполный гамма-субординатор, неполный гамма-субординатор с $\varepsilon$-скачками и темперированный неполный гамма-субординатор. Выводятся важные характеристики распределений указанных процессов, такие как среднее, дисперсия, корреляционная функция, вероятности хвостов распределений и дробные моменты. Обсуждается свойство долговременной зависимости для таких процессов. Подробно рассматривается применение в страховании. В заключение приводятся смоделированные выборочные траектории субординаторов.

Mangal S., Gupta V.

In this article, we develop and analyze a higher-order numerical scheme specifically designed to solve the generalized Black-Scholes model, a key mathematical model for the valuation of European options. Firstly, we employ the implicit Euler method in the time dimension and then apply the exponential B-spline collocation approach in the spatial dimension. Both the time and space discretization techniques are applied to the equidistant meshes, which leads to a tridiagonal system and is solved by the Thomas algorithm. A rigorous theoretical analysis is conducted to estimate the stability and convergence of the initial scheme. The resultant system is shown to be uniquely solvable and unconditionally stable using the Von Neumann stability analysis technique. Further, we demonstrate that the initial scheme achieves second-order spatial convergence and first-order temporal accuracy. To further improve the time accuracy of our scheme, we incorporate the Richardson extrapolation technique in the temporal domain. This technique combines solutions calculated at different time steps to obtain a more accurate solution. Using the Richardson extrapolation scheme, the refined numerical scheme is proven to be more efficient and achieve second-order convergence in both space and time domains. Some numerical experiments are employed to validate our theoretical findings. By comparing our results with those of other methods, we demonstrate the efficacy of our approach for practical applications.

Poorzare R., Kanellopoulos D.N., Sharma V.K., Dalapati P., Waldhorst O.P.

Keshtov M.L., Shikin D.Y., Sergeev V.N., Kalinkin D.P., Aleseev V.G., Karak S., Singhal R., Sharma G.D.

A new non‐fullerene small‐molecule acceptor (NFSMA), designated as TDPT‐TBA, is synthesized. This molecule is based on an S,N‐heteroacene central core connected to a weakly electron‐withdrawing end group, 1,3‐diethyl‐2‐thiobarbituric acid. In these findings, it is suggested that incorporating an sp2‐hybridized nitrogen atom into a fused cyclopentadiene framework, rather than utilizing a sp3‐hybridized carbon atom, can lead to a more effective NFSMA and potentially enhance the performance of organic solar cells. The TDPT‐TBA exhibits an upshifted lowest unoccupied molecular orbital energy level of −3.76 eV when compared to the Y6 acceptor. Additionally, there are complementary absorption spectra between both the polymer Poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′] dithio‐phene))‐alt‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl)benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione))] (PBDB‐T) and Y6. Organic solar cells utilizing the PBDB‐T:TDPT‐TBA blend achieves a high open‐circuit voltage of 0.942 V, yielding a power conversion efficiency (PCE) of 13.72%. When TDPT‐TBA is incorporated into a PBDB‐T:Y6 binary active layer, the optimized ternary organic solar cells reach a PCE of 16.06%, surpassing the efficiency of the binary PBDB‐T:Y6 configuration, which is 13.51%, under identical processing conditions. The increase in PCE can be attributed to several factors, including the utilization of excitons generated in TDPT‐TBA via energy transfer to Y6, a longer charge carrier lifetime, shorter charge extraction times, increased crystallinity, and denser stacking distance. These factors collectively contribute to reduced carrier recombination and improved charge transport.

Keshtov M., Khokhlov A., Shikin D., Liu J., Kalinkin D., Alekseev V., Singhal R., Sharma G.D.

In this study, two distinct unfused non‐fullerene acceptors (NFAs) are synthesized by arranging them in an A‐D‐D‐A pattern, both containing same D‐D central S, N‐heteroacene but different terminal acceptors, namely BTA (NFA‐2) and IC (NFA‐3). Their optical and electrochemical properties are investigated. Both NFA‐2 and NFA‐3 display the high lowest unoccupied molecular orbital energy level, leading to an increased open circuit voltage in the organic solar cells. PBDB‐T is chosen as polymer donor, showing spectral absorption that complements both NFAs. The optimized organic solar cells, based on PBDB‐T:NFA‐2 and PBDB‐T:NFA‐3 attained power conversion efficiency of 9.24% and 13.50%, respectively. Since the absorption characteristics of NFA‐2 and NFA‐3 are complementary, a small amount of NFA‐2 is added into PBDB‐T:NFA‐3 binary blend, the ternary organic solar cells attained a power conversion efficiency of 15.24%. The rise in power conversion efficiency is linked to the higher values of both short circuit current and fill factor. The increased short circuit current value in ternary organic solar cells is linked to the efficient use of excitons produced in NFA‐2 by transferring energy from NFA‐2 to NFA‐3 and effective exciton dissociation, faster charge extraction, decreased bimolecular and trap‐assisted recombination. The enhanced value of FF is also linked to the processes mentioned earlier. This investigation shows that it is advantageous to use separate non‐fused NFAs with absorption spectra that complement each other and have overlapped PL spectra of a medium bandgap acceptor along with the absorption spectra of a narrow bandgap NFA in ternary organic solar cells.

Khan A.N., Jena K., Chatterjee G., Chauhan M., Lenka T.R.

In this study, the effectiveness of AlGaN/GaN MOSHEMT with the inclusion of single-material-gate (SMG) and dual-material-gate (DMG) designs is examined. The higher transconductance, cut-off frequency and maximum oscillation frequency are essential components in Analog/RF uses and are produced by the DMG configuration. In this work, two different gate metal work functions ( $$\Phi $$ ) have been used, so the electric field ( $$\vec {E}$$ ) and electron velocity ( $$\vec {v}$$ ) are distributed uniformly in the GaN Channel. This obtained results of gm, fT, and fmax for the DMG devices are 14.28%, 10.6%, and 34.2% higher than the SMG devices, respectively. This outcome also shows better performance for Analog/RF performance parameters such as AV, TFP, GFP and GTFP for DMG configuration than SMG. The linearity parameters of SMG, like gm2, gm3, VIP2, VIP3, IIP3, IMD3, and P1dB show slightly better responses than the DMG. These findings suggest that the DMG AlGaN/GaN MOSHEMT can be used in applications that require high power and higher frequencies with signal amplification capabilities, while single metal gate devices show marginally improved linearity and low distortion-less profiles.