Vacation Period Research Articles

Effects of the vacation period on the health-related physical fitness of schoolchildren

The aim of the study was to verify the effects of the summer vacation period on the health-related physical fitness (HRPF) of students in the 7th and 8th grades of elementary school. The study design is characterized as observational, considered short-term longitudinal. Physical evaluations were carried out before and after the summer school vacation period. The components of physical fitness analyzed were: Cardiorespiratory fitness - 6-minute running or walking test, body composition- measures of body mass index, waist circumference and waist-to-height ratio, muscle strength/endurance - abdominal endurance test (sit -up) and flexibility - test of sitting and reaching. As a statistical analysis, the paired t-test was used, adopting p≤0.05. A significant increase was observed in the body mass index, waist circumference, waist-to-height ratio and flexibility after the vacation period. However, there were no significant changes in cardiorespiratory fitness and muscle strength/endurance. Furthermore, analyzing boys and girls separately, no differences were found for waist-to-height ratio and only girls showed improvements in muscle strength/endurance. It was concluded that the vacation exposure factor improved the levels of flexibility and increased the variables of body composition, not generating significant changes in cardiorespiratory fitness, while muscle strength/endurance improved only in girls.

The Markovian Bernoulli queues with operational server vacation, Bernoulli's weak and strong disasters, and linear impatient customers

This paper studies the stationary analysis of a Markovian queuing system with Bernoulli feedback, interruption vacation, linear impatient customers, strong and weak disaster with the server's repair during the server's operational vacation period. Each customer has its own impatience time and abandons the system as soon as that time ends. When the queue is not empty, the server's operational vacation can be interrupted if the service is completed and the server starts a busy period with a probability q or continues the operational vacation with a probability q. A strong disaster forces simultaneously all present customers (waiting and served) to abandon the system permanently with a probability p but a weak disaster is that all customers decide to be patient by staying in the system, and wait during the repair time with a probability p, where arrival of a new customer can occur. As soon as the repair process of the server is completed, the server remains providing service in the operational vacation period. We analyze this proposed model and derive the probabilities generating functions of the number of customers present in the system together with explicit expressions of some performance measures such as the mean and the variance of the number of customers in the different states, together with the mean sojourn time. Finally, numerical results are presented to show the influence of the system parameters on some studied performance measures.

Building Power Demand Estimation on Unusual Days Considering Facility Operation Status and Number of Occupants

To optimally conduct capital investment and energy management for buildings with storage batteries and photovoltaic (PV) generation, it is essential to accurately predict the electricity demand not only on weekdays but also on holidays and event days. However, predicting the building power demand on holidays and event days is difficult because facility operations and the number of occupants in a building are different from weekdays. In this paper, we propose a method to estimate unusual power demand by considering the power demand structure of existing buildings. The proposed method is an application of disaggregation techniques based on linear regression. First, a power demand structure model is developed by calculating the facility status demand contribution and number of occupants from weekday operational data. Second, the daily power demand is estimated with high accuracy by applying hypothetical operational scenarios, such as holidays, to the model. Experimental data from real offices confirm that the proposed method could estimate the power demand during weekends and vacation periods when the attendance rate is reduced by half.

A Non-Markovian Queue with Second Optional Service, Disasters, Working Breakdowns and Working Vacation

Inside this research article, we look at a non-Markovian queue (M/G/1) with second optional service, disaster events, working breakdowns and working vacation. There are two servers in the system: a primary and a backup. First Essential Service (FES) is delivered by a primary (backup) server to all arriving customers. A customer may choose the Second Optional Service (SOS) after his initial service is finished. When a disaster happens, all customers are made to evacuate the system, as well as the primary server crashes. The primary server is dispatched to repair at the first sign of a breakdown and the repair period begins right away. While a primary server is being repaired, a backup server is servicing customers at such a reduced rate. If a system is inactive while it is operating, the primary server will just go on vacation. The primary server, which is on working vacation mode and serving at a reduced rate, subsequently serves the new customers. The disasters have no effect on working vacation period. The supplementary variable methodology is used to determine the probability generating function (PGF) of the number of customers throughout typical peak times, working breakdown periods and working vacation periods, as well as specific metrics of effectiveness. Some statistical outcomes are shown at the end.

An M/G/1 Retrial G-queue with Multiple Working Vacation and a Waiting Server

An M/G/1 retrial G-queue with multiple working vacation and a waiting server is taken into consideration in this study. Both the retrial times and service times are assumed to follow general distribution and the waiting server follows an exponential distribution. During the working vacation period customers are served at a lesser rate of service. Before switching over to a vacation the server waits for some arbitrary amount of time and so is called a waiting server. We obtain the PGF for the number of customers and the mean number of customers in the invisible waiting area which is acquired by utilizing the supplementary variable technique. We compute the waiting time distribution. Out of interest a few special cases are conferred. Numerical outcomes are exhibited.

A longitudinal study of the occupancy patterns of a university library building using thermal imaging analysis

ABSTRACT Current debates around the ‘performance gap’ have highlighted the need to study building occupancy patterns to improve design solutions and better understand space utilisation. However, capturing occupancy data is resource intensive. There is a need for solutions that gather real-time occupancy data while maintaining the users’ privacy. In response to this challenge, this paper discusses applying a thermal imaging-based method for measuring occupancy in buildings and generating behavioural insights. A longitudinal analysis of the occupancy patterns over a full academic year is conducted for a university library building in the UK. The granular data collected through the thermal imaging analysis reveal insights into the building’s occupancy patterns over academic terms and vacation periods. The findings debunk conventional conceptions of library use during weekends/weekdays and terms/vacations. The application of thermal imaging sensors to monitor occupancy within the library building suggests the potential use of real-time data to improve the library’s space and organisational management. The paper makes a case for having an occupancy monitoring strategy in place that corresponds to the data needed for making effective interventions.

PECULIARITIES OF EVALUATING EDUCATIONAL ACHIEVEMENTS OF STUDENTS WITH A LOW LEVEL OF MOTOR ACTIVITY IN PHYSICAL EDUCATION CLASSES

The article examines the peculiarities of evaluating educational achievements in physical education classes of students with a low level of motor activity. Ways to increase the level of motor activity in physical education classes in higher education institutions are considered. It was determined that students of higher education institutions in physical education classes with a low level of motor activity have a significantly lower success rate when performing physical exercises than students with a high and medium level of motor activity. Therefore, in order to improve educational achievements and increase motivation, we have developed criteria for evaluating students taking into account the level of their motor activity and physical fitness. In order to solve this problem, experts suggest using, in addition to planned training classes, additional classes under the guidance of teachers in sports sections, independent physical training, as well as promoting the development of independence and activity of students by participating in sports and health activities during extracurricular and vacation periods. However, in order to conduct independent classes, students need to have certain health control skills, the dynamics of the development of physical qualities and motor skills, as well as special knowledge for the correct and adequate assessment of the results of classes with subsequent correction of various characteristics of motor activity. Thus, there are contradictions between the increased need to intensify the mental work of students in the modern educational space and insufficient motor activity of young people in the process of learning in institutions of higher education.

Cost Optimization using Genetic Algorithm in Customers Intolerance Markovian Model with Working Vacation and Multiple Working Breakdowns

In this paper we consider a single server queueing model with working vacation and multiple working breakdowns. When on vacation, the server works at a different pace. Disturbances occur in the server due to multiple breakdowns. In working breakdowns server works at a different rate. During the time of interruption caused by working vacation and working breakdowns, the main server can find many implementations in operation. Both the server's lifespan and the time it takes to repair it are considered to be exponentially dispersed. Also, we have considered balking and reneging behaviours of customers. The stationary queue length distribution is computed using a matrix-analytic technique. Using Genetic Algorithm (GA) we optimize the cost function. The predicted length of a busy period, the expected length of a working vacation period, the expected length of a working breakdown period, the mean waiting time, and the average delay are all established. We compute numerical results to verify the analytical point of view. The effect of individual parameters is investigated using sensitivity analysis.

Effects of visitor disturbance on tetrapod vertebrates in the Horton Plains National Park, Sri Lanka

Effect of visitor disturbances on tetrapod vertebrates was studied from December 2017 to October 2018 in the Horton Plains National Park (HPNP), which is one of the world’s best nature reserves and a popular tourist destination of Sri Lanka. Roads and nature trails with cloud forest, aquatic and grasslands habitats inside the HPNP were selected to compare the effect of visitor disturbances. Three 100 meter fixed length line transects were marked along the roads and the nature trails in each habitat. Vehicle noise was measured using sound meter software. Visitor activities that cause disturbance included road kills, photography, trampling and animal feeding. Amphibian and reptile road kills were higher compared to other tetrapod road kills during vacation periods. Behavioral response of species to visitor disturbances included avoidance, habituation and attraction. When the vehicle noise range was from 63±2.11 dB to 69±2.11 dB, habituation behavior was displayed. When the vehicle noise range increased to the range of 70±4.71 dB to 88±4.71 dB, avoidance behavior was displayed. Animals display a propensity to habituation behavior compared to avoidance behavior when vehicle speed was less than 30 kmh/hr. The results of this study can be used to integrate with the future visitor, park and wildlife management practices of the park.

The sleep as a predictor of musculoskeletal injuries in adolescent athletes

ObjectivesSleep is essential for musculoskeletal and cognitive recovery. Adolescent athletes tend to sleep poorly compared to adults and it may predispose them to sports injuries. Our aims are to estimate whether the quantity/quality of sleep are associated with sports injuries in adolescent athletes and to compare the quantity/quality of sleep between the training and competition seasons, and the school vacation period.Material and MethodsIt was a cohort study with 19 track and field athletes of both sexes, aged between 12 and 21 years. We evaluated their sleep-wake habit through actigraphy during three phases: 1 - mid-season, 2 - competition, and 3 - school vacation. The previous six months injury history and the occurrence of injuries in a six-month follow-up were recorded. Logistic regression and variance analysis were performed. The significance level used was 0.05.ResultsWake after sleep onset (WASO) predicted previous injuries (OR=1.144) and time awake (TA) predicted injury occurrence (OR=0.974). TA decreased from phase 2 to phase 3 (p=0.004), total sleep time (TST) increased from phase 2 to phase 3 (p=0.012), and WASO decreased between phases 1 and 2 (p=0.001) and between phases 1 and 3 (p=0.025).ConclusionOur study demonstrated that the quantity and quality of sleep were associated with musculoskeletal injuries in adolescent track and field athletes. Previous injuries were predicted by WASO and the occurrence of injuries was predicted by TA. Furthermore, during the vacation period they had lower TA and WASO, and higher TST than on school days.

Comparisons of customer balking behavior in observable queues with N policies and geometric abandonments

ABSTRACT This paper studies and compares customer balking behavior in some single-server observable queues with N policies and geometric abandonments. We focus on two types of N policies: the classic one and the modified one. Under the classic N policy, the server begins to take a vacation period as soon as the system becomes empty until there are N customers in the queue. On the other hand, under the modified N policy, the server takes multiple vacations until at least N customers are waiting in the queue when a vacation time ends. Abandonment opportunities occur during a whole vacation period, and customers decide independently and sequentially whether to renege. Comparing the two types of N policies, we realize that the residual time of the server's last vacation under the modified N policy indeed inhibits customers joining, whereas it may be more economic in practice if we take the whole system cost into consideration. As for the optimal N, under which the server is free of compensation, we observe that he should choose the modified N policy when the abandonment probability is much close to 1. Otherwise, he should choose the classic N policy.

Working Vacation Policy for Load Sharing K-out-of-N: G System

In industrial systems, the K-out-of-N: G system is a prominent type of redundancy. The load sharing protects such system from malfunctioning/destroying and avoids overload problem that affects the system reliability in a significant manner. In this paper we develop a Markovian model of load-sharing K-out-of-N: G system having non-identical repairable components wherein the server may on working vacation. During his vacation period, the server repairs the failed components with different service rates rather than completely terminating service rate. The failed component gets immediately repaired by the server if not on vacation, and unequal load is distributed among remaining surviving components. The lifetime of each component is load dependent followed by non-identical exponential distribution with different failure rates. The system is failed down due to common cause with failure density which is also exponentially distributed. We suggest closed structure analytic expressions for reliability, cost estimation and other performance measures of the load-sharing K-out-of-N: G repairable system by incorporating the concept of working vacation. For the solution aspiration, Runge-Kutta method is utilized to solve the system of differential equations. Furthermore, we perform the numerical analysis for two illustrations 1-out-of-3: G system and 3-out-of-4: G system. The numerical simulation is carried out for the validation of analytical results which are exhibited and compared by giving numerical outcomes and neuro-fuzzy outcomes based on fuzzy interference system with the help of MATLAB.

Understanding no-show behaviour for cervical cancer screening appointments among hard-to-reach women in Bogotá, Colombia: A mixed-methods approach

The global burden of cervical cancer remains a concern and higher early mortality rates are associated with poverty and limited health education. However, screening programs continue to face implementation challenges, especially in developing country contexts. In this study, we use a mixed-methods approach to understand the reasons for no-show behaviour for cervical cancer screening appointments among hard-to-reach low-income women in Bogotá, Colombia. In the quantitative phase, individual attendance probabilities are predicted using administrative records from an outreach program (N = 23384) using both LASSO regression and Random Forest methods. In the qualitative phase, semi-structured interviews are analysed to understand patient perspectives (N = 60). Both inductive and deductive coding are used to identify first-order categories and content analysis is facilitated using the Framework method. Quantitative analysis shows that younger patients and those living in zones of poverty are more likely to miss their appointments. Likewise, appointments scheduled on Saturdays, during the school vacation periods or with lead times longer than 10 days have higher no-show risk. Qualitative data shows that patients find it hard to navigate the service delivery process, face barriers accessing the health system and hold negative beliefs about cervical cytology.

Nutrient overload promotes the transition from top-down to bottom-up control and triggers dystrophic crises in a Mediterranean coastal lagoon

The excess input of nutrients that triggers eutrophication processes is one of the main destabilizing factors of coastal ecosystems, being coastal lagoons prone to suffer these effects and present dystrophic crises. This process is aggravated by the current trend of rising temperatures and more frequent torrential rains due to climate change. We observed that the Mar Menor lagoon had a great capacity for self-regulation of its trophic web and resistance to the eutrophication process, but after 30 years of nutrient input due to the change in the agricultural regime in its drainage basin in the 1990s, the lagoon ecosystem has suffered several of these events. In this work, we characterize the seasonal dynamic of the pelagic system during the last dystrophic crises. Phosphorus and nitrogen alternate as the limiting nutrient for phytoplankton proliferation. The entrance of phosphorus is mainly related to vacation periods, while nitrogen inputs, both superficial and sub-superficial, are more related to chronic high nitrates concentration in the water table after the agricultural activities carried out in the area changed. Our analysis reveals that the summer season is prone to suffer periodical hypoxia events when the N/P ratio decreases, and the temperature rises. In the Mar Menor, the ecological balance has been maintained in recent decades thanks to, among other mechanisms, the spatial and temporal segregation of top-down control over phytoplankton exerted by three species of jellyfish. However, the deep reduction in the abundance of the summer jellyfish species and the excessive proliferation of phytoplankton has meant the loss of this control. Moreover, we have registered a decline in the abundance of all the other zooplanktonic groups during the dystrophic crises. We suggest that management actions should address the input sources of water and nutrients, and an integrated management of the activities carried out throughout the watershed.

Analysis of batch size-dependent bulk service queue with multiple working vacation

ABSTRACT The present article analyses an infinite buffer batch size-dependent bulk service queue with multiple working vacation (MWV). The customer's arrival pattern follows the Poisson process, and they get the service in batches according to the general bulk service (GBS) rule in regular period (RP) as well as in working vacation period (WVP). After one service in RP, if the queue size is greater or equal to the lower threshold of the GBS rule, then the server performs the service in RP, otherwise, it starts the working vacation (WV) following exponential vacation time distribution. During the WVP, the server serves the customers in batches (if any) at a lower service rate than the usual service rate. The service time in the RP as well as in WVP is generally distributed. At an arbitrary epoch, the joint probabilities of the queue size and batch size with the server in RP as well as in WVP have been obtained using the supplementary variable technique (SVT) and the bivariate generating function method. Finally, some numerical observations are presented to enhance the applicability of the analytical results.

Effects of vehicle traffic and trampling on the macrobenthic community of Amazonian macrotidal sandy beaches

AbstractWe report for the first time the effects of vehicle traffic and beachgoer trampling on macrobenthic communities of Amazonian sandy beaches. Sampling was performed during four consecutive months with different beach use intensity in 2017 (before, during vacation, and two months after the vacation period) on three contrasting beaches with regard to disturbance (Urban: Atalaia; Intermediate: Farol-Velho; and Protected: Corvinas) in the intertidal zone along two equidistant transects at seven equidistant sampling stations from the high-tide water mark to the swash zone. At each sampling station, four biological and sediment samples were randomly collected. Also, in each station, the sediment compaction was determined using a manual penetrometer. Physical sediment variables remained constant over time in all beaches, whereas differences were found in sediment compaction over the months. Macrobenthic community differences in density and richness among months were observed at Atalaia and Farol-Velho beaches. In contrast, Corvinas beach remained constant throughout the study period. Furthermore, the vulnerability of the polychaetesThoracophellia papillata,Scolelepis squamataandParaonissp. indicates that they might be potential indicators of recreational activity impact.

Migraine in Adolescents: Comparison of Attack Frequency During School and Vacation Periods

This citizen science project CLUE compared the attack frequency between school and vacation periods among adolescents. The data collection process adopted in citizen science projects opens up the possibility of conducting analyses by including a large number of participants over a long period and across different regions. The data on 684 migraine attacks reported by 68 adolescents aged 16 to 19 years were collected using an online platform and smartphone apps. A Fisher’s exact test was used to compare the distributions of the migraine attack frequency during vacation and school periods in two different scenarios. In both scenarios, the attack frequency during school periods was significantly higher than that during vacation periods. The use of web-based data collection has some methodological limitations; however, it enabled the measurement of relative migraine attack frequency in students during vacation and school periods. The higher prevalence of migraine during school periods indicates the requirement of increasing headache awareness among children.

The Types and Determinants of Child Abuse in Sri Lanka

This study examines types and determinants of child abuse in Sri Lanka. Further, the study provides the demographic and social characteristics of victims who are aged below 18 years as well as their family background in Sri Lanka. There is an increasing trend of different types of child abuses globally as well as nationally. In Sri Lankan context, child sexual abuse reveals study mainly based on the secondary data and the main source of data was the National Child Protection Authority of Sri Lanka. Sample size includes all the complaints on child abuse from 2015-2020 to the NCPA Sri Lanka. The analysis of determinants of child abuse in Sri Lanka reveals as to who are the most vulnerable group for child abuse in Sri Lanka and what are the associated factors to be a child victim. Reporting child abuses have highly determined with the school vacation period and seasonal variation has affected by Covid-19 pandemic in 2020. Migration of parents has a negative impact on a child victim for abuse. Especially, the family background is a primarily determined factor to be a child victim. The nearest relatives to the family have been the major abuser of the children. Types of child abuse have analyzed based on the Penal Code and other child right related acts and regulations in Sri Lanka. Majority of the child abuses reported are related with the Penal Code and its amendments. Child right violation is at the highest level and the trend has shown a slightly declining pattern of child abuse but, still the number of abuses is at a higher level. However, the awareness programmes should be improved from school level and the knowledge on sexual and reproductive health also have to be improved to prevent child abuse in Sri Lanka.

A multi-station unreliable machine model with working vacation policy and customers’ impatience

ABSTRACT Working vacation queues with breakdowns and customers impatience have many applications in different real-life situations. The development of these models to determine their performance is extremely important. In this paper, we deal with a finite population Markovian multi-server machine system with breakdowns, repairs, Bernoulli feedback, balking, reneging, and retention of reneged customers, under multiple synchronous working vacations. The investigated model has a potential application in the real-world machine systems, such as the automated manufacturing systems with limited space. For the analysis purpose, we employ Q-matrix method in order to obtain the steady-state probabilities as well as closed-form expressions for several system characteristics. Particular cases of the current study are presented. We construct the expected cost function and develop an optimization problem to determine the optimum cost. The direct search method and the Quasi–Newton method are applied to find the optimum system capacity, the minimum number of servers, and the optimum service rates during both working vacation and regular busy periods at minimum cost. Lastly, a sensitivity analysis for the numerical simulation is carried out.

Spatio-Temporal Analysis Of Road Insecurity In Algeria: Case Of The Wilaya Of Oum El Bouaghi During The Period 2017-2019

We aim to analyze the characteristics and specifics of the road accident in the wilayas of Oum El Bouaghi, by emphasizing the space and time of the occurrence of traffic accidents on the roads of this wilaya. We arrived at several results, among them: the most populated daïras are the places which register more victims (Ain Beida, Oum El Bouaghi, Ain Mlila and Ain Fakroun), this confirms that the human factor is primarily responsible for road insecurity in Algeria; the national roads are the most deadly among the roads of the wilaya OEB; the summer vacation period, the weekend departure and return days and the return-to-work hours at the end of the day are the most risky periods and times on the roads of this wilaya.