Search Results (242)

The Vâlcea Subcarpathians, known for their wealth of natural resources and their spa tradition, are distinguished by renowned spa resorts such as Băile Olănești, Călimănești, Ocnele Mari and Băile Govora. These destinations provide tourists with a variety of treatment, relaxation, and recreational options. This research aims to explore the factors influencing tourist behavior at spa resorts in the Vâlcea Subcarpathians, Romania. Specifically, the relationships between tourists’ residential environment and frequency of visits, the influence of participation in cultural activities on the average duration of trips, and the impact of information sources and vacation planning methods on why tourists choose to visit spa resorts in the Vâlcea Subcarpathians, Romania, will be examined. As part of this study, a questionnaire was developed to collect relevant data on the perceptions and behaviors of visitors to spa resorts in the Vâlcea Subcarpathians, Romania. To analyze the collected data and test the research hypotheses, the following statistical methods were used: Chi-Square Test, Independent Samples t-Test and Analysis of Variance (ANOVA). The results obtained from the statistical tests largely confirmed the proposed hypotheses. There is a significant relationship between the age range of tourists and the frequency of visits, suggesting that different age groups have distinct visiting behaviors. Also, the perception of service quality varies by the gender of tourists, indicating that men and women have different experiences and expectations. Full article

This study proposes a Fuzzy-Based Control System (FBCS) for a Bulk Service Queueing Model with Vacation, designed to optimize service performance by dynamically adjusting system parameters. The queueing model is categorized into three service levels: (A) High Bulk Service, where a large number of arrivals are processed simultaneously; (B) Medium Single Service, where individual packets are handled at a moderate rate; and (C) Low Vacation, where the server takes minimal breaks to maintain efficiency. The Mamdani Inference System (MIS) is implemented to regulate key parameters, such as service rate, bulk size, and vacation duration, based on input variables including queue length, arrival rate, and server utilization. The Mamdani-based fuzzy control mechanism utilizes rule-based reasoning to ensure adaptive decision-making, effectively balancing system performance under varying conditions. By integrating bulk service with a controlled vacation policy, the model achieves an optimal trade-off between processing efficiency and resource utilization. This study examines the effects of fuzzy-based control on key performance metrics, including queue stability, waiting time, and system utilization. The results indicate that the proposed approach enhances operational efficiency and service continuity compared to traditional queueing models. Full article

Multiple sclerosis (MS) is a chronic progressive neurodegenerative disease that leads to disabilities such as difficulty moving and slowed cognitive processing. It is the leading non-traumatic cause of disability worldwide. MS also has a high potential to become a model for neurodegenerative diseases with a progression like Alzheimer’s or Parkinson’s. Cardiovascular diseases (CVDs) remain the leading cause of global deaths and have a considerable economic impact. The higher incidence of cardiovascular comorbidities in patients with MS compared to healthy individuals of the same age worsens the prognosis of neurological pathology, leading to a higher level of disability, poorer physical outcomes, higher depression scores, cognitive aging, and diminished quality of life. Classical observational studies often have questionable elements that can represent a source of error, making it difficult to establish a causal relationship between MS and CVD. Genetic studies, including genome-wide evaluation, may resolve this issue and may represent a topic for future research. We report the case of a 31-year-old male patient with a history of multiple sclerosis (MS) diagnosed seven years prior, who presented with acute chest pain upon returning from vacation. Despite the previous recommendation for disease-modifying therapy, the patient had discontinued treatment by personal choice. Electrocardiography (ECG) revealed ST-segment elevation in inferior leads, and emergent coronary angiography identified severe multi-vessel coronary artery disease (CAD), requiring immediate revascularization. This case highlights the potential cardiovascular risks in young patients with MS and the importance of continuous medical supervision. Full article

In this paper, we present an extensive literature review on queueing systems with working vacations. The concept of a working vacation generalises the concept of server vacations, which are time periods during which the server is absent and cannot serve waiting customers. During a working vacation, the server remains active, albeit at a reduced service rate. Our literature survey mainly highlights the structural properties of the Markov chains that underlie working vacation queueing models, as well as various methodological approaches to assessing the performance of queues with working vacations. Moreover, queueing games with working vacations and applications of queues with working vacations are discussed. Full article

Inspired by call centers, this paper models them as a constant retrial queue, with feedback and delayed vacations to balance high efficiency and low cost for service agents. After completing the service, the server randomly waits for an idle period. If customers arrive during this period, the service is provided immediately, otherwise, the server will take a vacation. We first derive steady-state probabilities and key performance measures. Then, the system cost is modeled. Particle Swarm Optimization (PSO), Ant Colony Algorithm (ACA) and Sparrow Search Algorithm (SSA) are applied to obtain the minimum system cost, respectively. To verify the correctness of the theoretical results of the system model, we simulate the model using Monte Carlo simulation to obtain the probabilities of different server states and the expected number of customers in the system, and then compare them with the theoretical values. At the same time, the sensitivity of the performance measures obtained by Monte Carlo simulation to the system parameters is also analyzed. Finally, customer behavior is analyzed, and equilibrium and socially optimal arrival rates are derived. In addition, the efficiency of the system is evaluated by examining efficiency indicators such as throughput and price of anarchy. Full article

The widespread practice of deliberate human displacement for biodiversity conservation remains a contentious issue in the Anthropocene era. This study explores the ecological impacts of conservation-led resettlement (ER) in Nepal’s Terai Arc Landscape (TAL), a biodiverse region under significant conservation and development pressures. Although ER aims to enhance ecological integrity, the role of displacement in conservation has been understudied. Using case studies from the TAL, we examined ecological indicators in vacated settlement areas within parks and newly resettled sites outside protected zones. Data were collected through a review of secondary literature, 240 household interviews, 5 focus group discussions, 25 key informant interviews, and multiple field visits across resettlement sites. Between 1973 and 2019, TAL gained 922.52 sq. km of core protected areas (displacing over 4800 households) and dispossessed communities from 2120.12 sq. km of buffer zones, significantly expanding protected areas and upgrading conservation standards from IUCN category IV to II. This contributed to the recovery of key species such as tigers, rhinos, and elephants. However, resettlements, often located along critical biological corridors and buffer zones, led to habitat fragmentation, endangering the gene pool flow and creating isolated habitats. Results show that, in general, most ecosystem and environmental variables were perceived significantly different (p < 0.05) among resettled communities in the study area. The cultural and land-based attachments of displaced communities were overlooked. These findings highlight the risks of short-term resettlement planning, which can exacerbate pressures on critical corridors, escalate human–wildlife conflicts, and provide a clear indication of the trade-off between conservation benefits and social costs. Full article

The Canary Islands have long been a major European destination for mass tourism, often associated with ‘sun-and-beach’ vacations. Critiques of mass tourism have intensified in recent years, as reflected in the 2024 protests in the Canary Islands, which linked mass tourism to economic inequalities and concerns about sustainability. Through the case example of Icelandic tourism to the Canary Islands, this research asks two questions: (a) why mass tourism destinations are appealing, and (b) how these reasons can be more fully understood within a broader geopolitical and structural context. The research methods include a survey conducted in Iceland in 2022 and an analysis of media coverage in Iceland related to the Canary Islands from 2017 to 2022. Survey data indicate that the islands are primarily perceived as an easily accessible, well-established holiday destination. Simultaneously, an analysis of media discussions reveals a limited discourse on the islands in Icelandic media, mainly focusing on tourism. The results illustrate how specific destinations become desirable by prioritizing infrastructure associated with mass tourism, where tourism’s impact on host communities, economies, and environments tends to be invisible. Full article

This study investigates tandem queues with two service nodes. The consumer needs to obtain services at the following two nodes in this system: the IBM online sphere for artificial intelligence (AI) and the complex RDX mechanism. Before the second essential service (SES), by utilizing AI to validate the data in IBM WebSphere and insight, the first essential service (FES) begins with the RDX mechanism. If there are fewer customers than “a” after a service at node 1 is finished, the server departs for a subsequent assignment. As soon as the vacation value reached the threshold, the service began. After the service concludes at node 1, it moves on to node 2. In this study, the supplemental variable technique is used to determine the probability-generating function (PGF) at any given time. A numerical solution also yields certain features of the queueing system. Full article

With the advancement of science and technology, industrial robots have become indispensable equipment in advanced manufacturing and a critical benchmark for assessing a nation’s manufacturing and technological capabilities. Enhancing the reliability of industrial robots is therefore a pressing priority. This paper investigates the drive system of industrial robots, modeling it as a series system comprising multiple components (n) with a repairman who operates under a single vacation policy. The system assumes that each component’s lifespan follows an exponential distribution, while the repairman’s repair and vacation times adhere to general distributions. Notably, the repairman initiates a vacation at the system’s outset. Using the supplementary variable method, a mathematical model of the system is constructed and formulated within an appropriate Banach space, leading to the derivation of the system’s abstract development equation. Leveraging functional analysis and the $C_0$-semigroup theory of bounded operators, the study examines the system’s adaptability, stability, and key reliability indices. Furthermore, numerical simulations are employed to analyze how system reliability indices vary with parameter values. This work contributes to the field of industrial robot reliability analysis by introducing a novel methodological framework that integrates vacation policies and general distribution assumptions, offering new insights into system behavior and reliability optimization. The findings have significant implications for improving the design and maintenance strategies of industrial robots in real-world applications. Full article

In recent years, Serbia has become increasingly popular as a tourism destination, attracting travelers from the surrounding region, as well as Europe and even distant locations. The environmental impact linked with tourism activities, specifically their carbon footprints, has gained growing attention as sustainability becomes an important factor when discussing the future of tourism. This research, which is based on the DEFRA and ADEME methodologies using the Greentripper tool, examines the significance of carbon footprint estimations for incoming tourism in Serbia from a scientific standpoint. By considering the emissions produced from transportation, accommodation, and on-site activities, the results of 1,431,394,511 kg CO2e offer valuable information about the extent of carbon emissions linked to tourism movements. The primary driver of this carbon footprint is transportation (80.2%), on-site activities (15.2%), and housing (4.6%). The per capita tourism carbon footprint is 670 kg CO2e, which is lower compared to the values derived using general data and carbon emissions on a worldwide basis, which amount to 759 kg CO2e. These findings are essential for comprehending the environmental sustainability of tourism operations. Furthermore, carbon footprint assessments play a crucial role as a tool for making informed decisions and implementing initiatives to reduce carbon emissions in the tourism business. This could involve selecting environmentally friendly modes of travel, advocating for sustainable hotel choices, or integrating carbon offsetting activities into vacation packages. In addition, carbon footprint assessments promote transparency and responsibility in the tourism industry. Full article

In June 2024, a 41 year-old woman presented to the infectious diseases outpatient clinic with a left inguinal mass progressing in size. The patient had previously been on vacation in Greece. When a tumor was initially suspected, the mass was surgically removed. Staining with Grocott methenamine silver and Alzian blue were inconspicuous, but histopathologic examination revealed a clear histiocytic demarcation, followed by a confirmation of the suspected diagnosis of dirofilariasis caused by Dirofilaria repens by PCR. Even though still a rare event in Austria, the number of human D. repens cases has been continuously increasing in recent years. This is partly due to the increased spread of the parasite due to climate change and globalization. Full article

Tourism refers to the activity of traveling for pleasure, recreation, or leisure purposes. It encompasses a wide range of activities and experiences, from sightseeing to cultural exploration. In today’s digital age, tourists often organize their excursions independently by utilizing information available on websites. However, due to constraints in designing customized tour routes such as travel time and budget, many still require assistance with vacation planning to optimize their experiences. Therefore, this paper proposes an algorithm for personalized tourism planning that considers tourists’ preferences. For instance, the algorithm can recommend places to visit and suggest activities based on tourist requirements. The proposed algorithm utilizes an extended model of the team orienteering problem with time windows (TOPTW) to account for mandatory locations and activities at each site. It offers trip planning that includes a set of locations and activities designed to maximize the overall score accumulated from visiting these locations. To solve the proposed model, the Adaptive Neighborhood Simulated Annealing (ANSA) algorithm is applied. ANSA is an enhanced version of the well-known Simulated Annealing algorithm (SA), providing an adaptive mechanism to manage the probability of selecting neighborhood moves during the SA search process. The computational results demonstrate that ANSA performs well in solving benchmark problems. Furthermore, a real-world attractive location in Tak Province, Thailand, is used as the case study in this paper to illustrate the effectiveness of the proposed model. Full article

Introduction: Work is an essential aspect of human life. However, high expectations from employers and clients, combined with time pressure and chronic stress, can contribute to burnout among employees in service professions. Aim of the Study: This study aimed to compare the prevalence of burnout syndrome between two occupational groups—corporate office workers and active nurses—and to assess the influence of socio-demographic factors on the level of burnout in both groups. Materials and Methods: The study was conducted among 330 participants, including 126 nurses (38%) and 204 corporate employees (62%). Data were collected using a standard questionnaire and the Maslach Burnout Inventory. The study period spanned from November 2018 to October 2019, and questionnaires were distributed via email. Results: The findings revealed that both corporate employees and nurses experience occupational burnout. Both groups predominantly exhibited moderate to high levels of emotional exhaustion (nurses: 66.67%, q2 = 20.5; corporate employees: 73.53%, q2 = 31.5) and low to moderate levels of personal accomplishment (nurses: 78.57%, q2 = 32.0; corporate employees: 87.75%, q2 = 27.0). Corporate employees showed significantly higher depersonalization scores (q2 = 13.50) compared to nurses (q2 = 5.0). The prevalence of burnout in both groups was influenced by socio-demographic factors, including having children, their place of residence, education, earnings, and job-related factors such as vacation availability, the frequency of work shifts, work systems, overtime, and overall job satisfaction. Conclusions: Service-oriented professions that involve caregiving and direct interpersonal interactions face comparable risks of occupational burnout. Despite differences in the nature and conditions of work, as well as tasks performed, both corporate employees and active nurses are vulnerable to burnout. High salaries were not confirmed as a protective factor against occupational burnout. Additionally, environmental factors, particularly those related to working conditions, played a significant role in the development of burnout syndrome, alongside individual factors. Full article

This research analyzes a multi-server retrial queue with two types of calls: working vacation and working breakdown. The incoming call may enter the retrial queue and attempt to seize a server after a random delay if all the servers are unavailable upon arrival. In its idle time, the server makes outgoing calls. All the servers take a synchronous working vacation when the system empties after regular service. The system may fail at any time due to disasters, forcing all the calls within the service area to leave the system and causing all the main servers to fail. When the main servers fail, the repair process begins immediately. The standby servers serve arriving customers at a lower level of service during the working breakdown or working vacation. For this model, we derive an explicit expression for the stationary distribution with the help of the quasi-birth-and-death process and the matrix geometric method. Further, the formulas of various system performance indices are developed. An application example is given and several numerical experiments are performed to verify the analytical results. We also perform the comparative analysis of retrial queues with/without two-way communication and two-way communication retrial queues with/without disasters. The results reveal that the proper consideration of outgoing calls to the server can reduce the average time spent in the buffer. Furthermore, a more reliable server reduces the server idle rate. Full article

Given the persistently high incidence of skin cancer, there is a need for prevention-focused information on the impact of long-term changes in ambient solar ultraviolet radiation (UVR) on human personal radiation exposure. The exposure categories of the UV Index linked to protection recommendations show long-term shifts in the frequency of occurrence with regional differences in direction and magnitude. The patterns of change for sites in the humid continental climate differ from those for sites in other climate zones such as the humid temperate or Mediterranean climate. The diversity of the individual exposures of indoor and outdoor workers can be described using probability models for personal erythema-effective UVR dose (UVD). For people who work indoors, the largest share of the total individual annual UVD is due to vacation, whereas for people who work outdoors, it is occupational exposure. The change in ambient UVDs at the residential locations is only partially reflected in the individual UVDs. For eight selected European sites between 38° and 60° northern latitude, the median of the individual annual total UVD (excluding travel) during the period 2009–2019 is 0.2 to 2.0% higher for indoor workers and 0.6 to 3.2% higher for outdoor workers compared to the period 1983–2008. Changes in the choice of an exemplary holiday destination offer both indoor and outdoor workers the potential to compensate for the observed long-term trend at their place of residence and work. Full article