Letter To Editor

Since individuals spend the majority of their times indoors, fine particles generated in indoor combustion processes and by resuspension are important for health effects assessment. The nature and magnitude of indoor particle exposures can change rapidly because of the rapid changes in activities and sources. Indoor PM2.5 concentrations were measured in indoor office, café, and home where people spend majority of their time in there. A real time monitor was used to provide a high degree of resolution for investigating temporal patterns in particle concentrations. The average PM2.5 concentration obtained from the direct reading compared with the mean PM2.5 concentrations that are obtained by gravimetric measurements during the same continuous sampling. Mean PM2.5 concentrations in the big office were more than twice as high as those measured in the small quiet office (19.8 and 7.3 respectively). In the home, cooking increased PM2.5 concentration. The highest particle concentrations in home (average 28 mg m-3) were related to a period around midnight when there were a larger number of occupants inside the living room. Mean PM2.5 concentrations measured in the smoking area of the cafe were much higher than those measured in the non-smoking area (50.0 and 17.6 mg m-3 respectively). Outdoor air pollution can affect the indoor particulate concentration when the indoor source not exists. Smoking, cooking, and resuspension of indoor particulate matter are the most important sources for indoor particle concentrations.

Van Leeuwen’s model of critical discourse analysis, which uncovers patterns of representing social actors through sociological-semantic components, offers an effective framework for explaining the complex network of social actors’ representations in narrative fiction. This approach focuses on how individuals, groups, and institutions are represented in social discourses, shedding light on the underlying power structures and social relationships they reflect. Farhad Jafari’s Café Piano, a notable work of contemporary fiction with diverse representations of social actors, provides an appropriate basis for analyzing the roles and identities of these actors. Drawing on Van Leeuwen’s model, this article explores how social actors are represented in Café Piano, aiming to elucidate the intricate web of social actors in this novel. The research findings suggest that the novel’s numerous social actors are not merely peripheral figures; rather, they are integral to the narrative structure and reflective of broader social and cultural discourse. By focusing on middle-class characters and illustrating the effects of social and economic challenges on their lives, Café Piano offers a nuanced portrayal of the contemporary middle class and its struggles. The use of certain sociological-semantic components also adds depth to the individual and social representation of the characters. The research method is descriptive-analytical, supported by a quantitative approach to identify and analyze the sociological-semantic components used in the text.

Problem statement: This study examines the interplay between ascribed identity and resistant identity in relation to musical and para-musical elements, in the formation of a distinct cultural identity within Tehran’s café spaces. It also seeks to understand and explain the complexities of preserving an independent identity within a commercialized environment. The ascribed identity, rooted in intellectualism, independence, and alternative values, is evaluated in comparison with the resistant identity, which consists of opposition to popular musical elements and distancing from the dominant body of Iran’s mainstream music industry. Research objective: The central question of this research is to investigate the extent to which the independent music scene remains committed to the identity ascribed to it. Research method: This study employed qualitative, comparative, and content analysis methods. Data collection was conducted both in the field and through library research. The fieldwork took place in Tehran and, virtually, in Austria during the winter of 2022–2023. Conclusion: Drawing on the theories of Stuart Hall, Theodor Adorno, Timothy Rice, Antonio Gramsci, and Michel Foucault, this research highlights the interactions between cultural identity, commodification, and the influence of Western music on Iran’s urban music spaces. The findings reveal a substantive overlap between the independent music movement in recent years and the popular music scene, which must be considered a major contradiction in achieving the ultimate goal of independence within today’s Iranian music industry.

Distributed Denial of Service (DDoS) attacks are among the primary concerns in internet security today. Machine learning can be exploited to detect such attacks. In this paper, a multi-layer perceptron model is proposed and implemented using deep machine learning to distinguish between malicious and normal traffic based on their behavioral patterns. The proposed model is trained and tested using the CICDDoS2019 dataset. To remove irrelevant and redundant data from the dataset and increase learning accuracy, feature selection is used to select and extract the most effective features that allow us to detect these attacks. Moreover, we use the grid search algorithm to acquire optimum values of the model’s hyperparameters among the parameters’ space. In addition, the sensitivity of accuracy of the model to variations of an input parameter is analyzed. Finally, the effectiveness of the presented model is validated in comparison with some state-of-the-art works.