Design of experiments (DOE) analysis of the effects of environmental conditions on bloodstain degradation using spectroscopic methods

Abstract Blood is one of the most common types of trace found at crime scenes. However, from a forensic point of view, the potential of blood traces is still not fully exploited, as there is as yet no reliable technique for dating blood traces found at scenes. The same difficulties are cited in the literature for published research on blood traces: the mechanisms of blood degradation are known and validated, but traces found at scenes are not controlled samples. Traces therefore need to be evaluated in the light of this uncertainty and the factors that can influence the blood trace dating model. In the course of this project, we assessed the significance of the environmental effects of temperature (10–40°C), humidity (25–75 %) and radiation (none and maximum) using three different spectroscopic techniques: Raman spectroscopy, MicroNIR spectroscopy and hyperspectral imaging. The use of a climatic chamber with the addition of LED lamps (daylight and UV) enabled parameters to be controlled during a 3-day aging period for each sample. By means of a 2-level experimental screening design of the three factors, we were able to observe complementarity between the methods used. Raman spectroscopy highlighted the influence of temperature, MicroNIR spectroscopy provided information on the influence of temperature and relative humidity, and hyperspectral imaging demonstrated the influence of temperature and the presence of radiation. These results provide a better understanding of the factors that cause the blood degradation model to deviate, enabling us to develop a more comprehensive model of these factors

Contraband tobacco: Systematic profiling of cigarette packs for forensic intelligence

Abstract Tobacco smuggling remains a widespread illegal activity in Canada, associated with important social and economic impacts, and often linked to organized crime. This study explores the application of forensic profiling as an intelligence tool to support the analysis of contraband cigarette production and distribution. Physical and chemical manufacturing characteristics of seized contraband cigarette packs, provided by police forces, were observed and coded using macroscopic, microscopic, and spectroscopic techniques. Multivariate statistical analyses were then conducted to compare manufacturing characteristics between packs and identify potential links. The analyses highlighted links between cigarette packs and seizures based on shared manufacturing characteristics. The results and the identified groups were also compared with seizure data provided by our collaborator. The results demonstrate the relevance of forensic profiling to formulate hypotheses regarding shared production processes or supply networks. These hypotheses provide information that contributes to understanding tobacco smuggling and aim to examine how forensic intelligence can support law enforcement and measures to prevent and disrupt this criminal activity. A preliminary optimal procedure for applying forensic profiling in operational contexts targeting contraband tobacco was finally proposed. Despite limitations in the dataset creation that were beyond our control, this study represents a starting point for applying this scientific approach to tobacco smuggling

Centralized multi-agent SOC control for battery health using proximal policy optimization in EVs

Abstract Lithium-ion batteries (LIBs) have garnered significant attention due to their expanding use in various applications, including electric vehicles (EVs) and smart grids. To meet the diverse requirements of these applications, LIB cells are configured in different architectures, such as multiple cell/module/pack which are arranged in series and parallel configurations. In series configurations, a state of charge (SOC) balancing system is essential to ensure uniform SOC levels across all cells. For battery electric vehicles (BEVs), which rely solely on LIBs as their energy storage system [ESS], maximizing the ESS capacity is crucial for extending the driving range. SOC balancing is a key strategy to achieve optimal utilization of ESS capacity in EVs. This paper presents a model-free cooperative multi-agent control framework designed to regulate and balance the SOC of lithium-ion battery (LIB) cells in EVs during real-time driving operations. The proposed method utilizes a series architecture comprising three LIB cells, each equipped with a buck-boost converter and a proportional-integral (PI) controller, controlled by a reinforcement learning (RL) agent. The Proximal Policy Optimization (PPO) algorithm is used as the RL agent in this multi-agent framework, where each PPO agent independently manages the SOC of a corresponding battery cell based on observed data. During the training phase, all PPO agents work collaboratively to balance the SOCs of the LIB cells, thereby preventing interruptions in EV performance. The effectiveness of the proposed approach is demonstrated by comparing its performance with single-agent methods such as PPO, Soft Actor-Critic (SAC), and Twin Delayed Deep Deterministic Policy Gradient (TD3), as well as with other multi-agent methods. The results show that the proposed method performs better than the existing approaches, indicating its potential for superior performance

SMEs’ resilience in the manufacturing sector: The role of formalized risk management and risk culture

Based on an integration of the literatures in small business, risk management, organizational resilience, and management control, this article examines the impact of a risk-tolerant culture and formalized risk management on organizational resilience in small and medium enterprises (SMEs). Survey data were collected on 500 Canadian manufacturing SMEs and Partial least squares (PLS) analyses were used to test the hypothesized model. PLS results indicate that a risk-tolerant culture is positively associated with resilience, while formalized risk management is not. When focusing on the subset of firms that have formalized their risk management, both a risk-tolerant culture and formalized risk management are found to enhance resilience. However, these results hold only when environmental turbulence is low. Overall, our findings suggest that fostering a risk-tolerant culture is crucial for SMEs’ resilience, while the impact of formalized risk management on resilience depends on the firm context