Stationary Test Research Articles

Time synchronisation for millisecond-precision on bio-loggers

AbstractTime-synchronised data streams from bio-loggers are becoming increasingly important for analysing and interpreting intricate animal behaviour including split-second decision making, group dynamics, and collective responses to environmental conditions. With the increased use of AI-based approaches for behaviour classification, time synchronisation between recording systems is becoming an essential challenge. Current solutions in bio-logging rely on manually removing time errors during post processing, which is complex and typically does not achieve sub-second timing accuracies.We first introduce an error model to quantify time errors, then optimise three wireless methods for automated onboard time (re)synchronisation on bio-loggers (GPS, WiFi, proximity messages). The methods can be combined as required and, when coupled with a state-of-the-art real time clock, facilitate accurate time annotations for all types of bio-logging data without need for post processing. We analyse time accuracy of our optimised methods in stationary tests and in a case study on 99 Egyptian fruit bats (Rousettus aegyptiacus). Based on the results, we offer recommendations for projects that require high time synchrony.During stationary tests, our low power synchronisation methods achieved median time accuracies of 2.72 / 0.43 ms (GPS / WiFi), compared to UTC time, and relative median time accuracies of 5 ms between tags (wireless proximity messages). In our case study with bats, we achieved a median relative time accuracy of 40 ms between tags throughout the entire 10-day duration of tag deployment. Using only one automated resynchronisation per day, permanent UTC time accuracies of ≤ 185 ms can be guaranteed in 95% of cases over a wide temperature range between 0 and 50 °C. Accurate timekeeping required a minimal battery capacity, operating in the nano- to microwatt range.Time measurements on bio-loggers, similar to other forms of sensor-derived data, are prone to errors and so far received little scientific attention. Our combinable methods offer a means to quantify time errors and autonomously correct them at the source (i.e., on bio-loggers). This approach facilitates sub-second comparisons of simultaneously recorded time series data across multiple individuals and off-animal devices such as cameras or weather stations. Through automated resynchronisations on bio-loggers, long-term sub-second accurate timestamps become feasible, even for life-time studies on animals. We contend that our methods have potential to greatly enhance the quality of ecological data, thereby improving scientific conclusions.

ANALISIS INTEGRASI PASAR SPASIAL HARGA TELUR AYAM RAS MENGGUNAKAN METODE VECTOR ERROR CORRECTION MODEL

Purebred chicken eggs are one of the staple commodities whose price development continues to be monitored by the government. To maintain price stability of purebred chicken eggs, an understanding of spatial market integration is needed. Spatial market integration can show the level of closeness between markets in a region. The spatial market integration in this study was modeled using the Vector Error Correction Model (VECM) method. The VECM method was chosen with the aim of seeing the relationship between the price movement of purebred chicken eggs both in the short and long term, seeing the interaction of relationships that occur in each region and forecasting the price of purebred chicken eggs. The research objects used include the price of purebred chicken eggs in Semarang City, Salatiga City, Demak Regency, and Pati Regency in the period January 2021 to December 2022. The data used is weekly time series data that has met the stationary test at the first differential level. Based on the Johansen cointegration test on the four regions, 3 cointegrations were obtained, indicating that in each short-term period all variables adjust to each other to achieve long-term equilibrium. Granger's causality test in this study showed that not all variables have a two-way relationship. The resulting MAPE value is less than 10%, so the resulting model is very feasible to use.

American Football Headgear Impairs Visuomotor Drill Performance in Division I NCAA Football Athletes.

Background/Objectives: Previous evidence has shown that American football headgear (e.g., facemasks, visors/eye shields) differentially impairs reaction time (RT) to visual stimuli, most notably in peripheral fields of view. However, this has only been established with stationary RT testing, which may not translate to gameplay situations that require gross motor skills. Therefore, the purpose of this study was to build upon previous findings to elucidate the effects of various American football headgear on gross motor visuomotor drill performance. Methods: Division 1 NCAA football players (n = 16) with normal/corrected-to-normal vision participated and completed two experiments (EXP), each with differing conditions: EXP1- Varying facemask reinforcement and EXP2- Varying visor/eye shield light transmittance. In EXP1, participants completed an agility test for the following conditions: baseline/no helmet (BL), helmet + light (HL), helmet + medium (HM), and helmet + heavy (HH) face mask reinforcement. In EXP2, participants completed an agility test for the following conditions: baseline/no helmet (BL), helmet + clear visor (HCV), helmet + smoke-tinted visor (HSV), and helmet + mirrored visor (HMV). For each condition in EXP1 and EXP2, participants completed a reactive agility task using a FITLIGHT trainer system where five poles were equipped with a total of ten LED sensors and were placed in a semi-circle 1 m around a center point. Participants were asked to step and reach with their hands to hit each ten lights individually as fast as possible upon illumination. Each reactive agility test was repeated for a total of three attempts. Results: Average reaction time was analyzed and compared between conditions and according to visual fields of interest (e.g., central vs. peripheral). Results from EXP1 showed that compared to BL, reactive agility was worsened by HL (p = 0.030), HM (p = 0.034), and HH (p = 0.003) conditions. No differences between facemask conditions existed for overall performance (p > 0.05). For EXP2, HCV (p < 0.001), HSV (p < 0.001), and HMV (p < 0.001) conditions resulted in worsened reactive agility performance compared to BL. No differences between visor conditions existed for overall performance (p > 0.05). Conclusions: Overall, these findings suggest that American football headgear impairs reactive agility, which could result in worsened game performance and safety. Future studies investigating training strategies to overcome impairments are warranted.

Influence of Fix Schedule on the Location Accuracy of a Low-Cost GPS Data Logger on Cattle

ABSTRACT Global positioning system (GPS) data loggers are commonly used to track the movements and distribution of both wild and domestic animals. However, the expense often poses a challenge for researchers. Recently, there has been a rise in the utilization of affordable and user-friendly GPS data loggers for tracking animal movements, albeit with compromised accuracy. We aimed to identify factors influencing the accuracy of a low-cost GPS data logger (I-gotU GT-600) and to enhance its location accuracy. Initial investigations revealed that recording intervals impacted the location error of the GPS data logger. To elucidate the relationship between recording intervals and location accuracy, we conducted stationary and motion tests. Our findings indicated that recording intervals of less than 15 sec substantially enhances the location accuracy of the low-cost GPS data logger. Our results highlight the relationship between the fix schedule and location accuracy for these GPS data loggers. Our study provides information that enhances the quality of data for researchers using low-cost GPS data loggers for short-term studies in various settings, such as zoos and livestock facilities.

The Influence of HDI, Per Capita Income, Population Growth on Poverty on Java Island in 2017-2022 with Zakat as a Moderating Variable

This research aims to determine the effect of the Human Development Index, Per Capita Income, and Population Growth on Poverty on Java Island in 2017-2022 with Zakat as a Moderating Variable. This type of research is quantitative research with a population, namely the Province of Java Island. Meanwhile, the sample for this research was determined using the Saturated Sampling method with criteria determined by the researcher so that a sample of 36 samples from 6 provinces were obtained during the observation period (2017-2022). The type of data used is panel data. The analytical methods used include descriptive tests, statistical tests, stationary tests, multiple regression tests, T-tests, F tests, R² tests, classical assumption tests, and MRA tests. The Moderated Regression Analysis (MRA) test uses Eviews 10 data processing software. The results of the research partially show that the Human Development Index variable has a negative and significant effect on poverty and Per Capita Income has a negative and significant effect on poverty. Based on the Moderated Regression Analysis (MRA) test, shows that the interaction of Zakat is unable to moderate the influence of the Human Development Index, Per Capita Income, and Population Growth.

THE EFFECT OF RICE PRICE ON THE INDONESIAN INFLATION IN A NEW INSTITUTIONAL ECONOMIC PERSPECTIVE

The aim of this research is to identify and verify whether rice prices do play a role in driving national inflation using time series data. The time series data for this study spans from 2017 to 2023 on a monthly basis. To facilitate our analysis, we subject the data to standardized stationary tests, serving two essential purposes. Firstly, these tests ascertain the constancy of mean, standard deviation, variance, and covariance for each observation. Secondly, they aid in determining the extent of integration among the variables under scrutiny. For this particular purpose, we employ the Augmented Dickey-Fuller Test for Unit Roots. The outcomes of these stationary tests provide crucial insights, directing policy decisions to effectively address the challenge of inflation. It is widely acknowledged that the factors driving inflation rates, not only in Indonesia but globally, can be classified into two primary categories, the first being associated with the money supply. The research findings distinctly demonstrate that while rice certainly plays a role, it is not the exclusive or singular underlying cause of fluctuations in the inflation rate.

Analysis of Non-Road Mobile Machinery Homologation Standards in Relation to Actual Exhaust Emissions

This article presents issues related to the current approval procedures in the group of off-road vehicles. Our research aimed to demonstrate significant differences between actual railway vehicle operation and stationary homologation tests regarding exhaust emissions. The research cycle consisted of analyzing emissions of toxic compounds from exhaust systems under real operating conditions, supplemented by a temporal share analysis based on the denormalized NRTC test upon which the tested object was homologated. Based on the conducted analyses, a significant difference was found between the actual operation of the tested railway vehicle and the stationary homologation test. By interpreting emission intensities within the parameter ranges of the propulsion unit’s operation, key areas with a significant impact on the vehicle’s overall emissions were identified. Based on the obtained results, a critical opinion is expressed regarding current homologation standards for the off-road vehicle group and the necessity for further empirical research in the area of actual operation of the tested vehicle group.

Nonstationary Time Series Models Using ARDL and NARDL Estimation

The paper features an examination of the link between the behavior of the Money supply and Bank deposit in both an autoregressive distributed lag ARDL, plus a nonlinear autoregressive distributed lag NARDL framework. The regression relationship between any two nonstationary time series suffer from the problem of superior regression and the results may be incorrect and unreliable, and to overcome this problem the aim of this paper was find a balanced relationship in the long - run between the variables of Money supply and Bank deposits using the method of cointegration by focusing on the behavior of the residuals of the cointegration model based on monthly data for a time series for the period (2010-2015). The time series stationary test was done by conducting the Unit Root Test based on the Philips-Perron test to find out the stationary of the variables and then detect the existence of the cointegration using the bounds testing, the tests showed the nonstationary of the time series at level I(0) and their become stationary after taking the first differences I(1). Bounds test showed the existence of cointegration .The Error correction model for the ARDL model was the best, despite the convergence of most of the test results for the two models, but the ARDL model was the more accurate with the speed of adjustment in the short -run to return to long-run equilibrium, as it reached (37%) and a period of two months for the ARDL model, while the percentage for the NARDL model was equal to (28%) and a period of time of approximately three and a half months.

The Influence of Powering a Compression Ignition Engine with HVO Fuel on the Specific Emissions of Selected Toxic Exhaust Components

The aim of the research was to determine the potential of hydrotreated vegetable oil (HVO) in reducing nitrogen oxides and particulate matter emissions from the Perkins 854E-E34TA compression ignition engine. The concentrations of these toxic exhaust gas components were measured using the following analyzers: AVL CEB II (for NOx concentration measurement) and Horiba Mexa 1230 PM (for PM measurement). The measurements were carried out in the ESC test on a compression ignition engine with direct fuel injection and a turbocharger. The engine had a common rail fuel supply system and met the Stage IIIB/Tier 4 exhaust emission standard. Two fuels were used in the tests: diesel fuel (DF) and hydrotreated vegetable oil (HVO). As part of the experiment, the basic indicators of engine operation were also determined (torque, effective power, and fuel consumption) and selected parameters of the combustion process, such as the instantaneous pressure of the working medium in the combustion chamber, maximum pressures and temperatures in the combustion chamber, and the heat release rate (HRR), were calculated. The tests were carried out in accordance with the ESC test because the authors wanted to determine how the new generation HVO fuel, powering a modern combustion engine with a common rail fuel system, would perform in a stationary emission test. Based on the obtained research results, the authors concluded that HVO fuel can replace diesel fuel in diesel engines even without major modifications or changes in engine settings.

EDU_VACCINE app: Mobile application for public health students and health educators

BackgroundOne of the valuable tools in virtual education is mobile phone-based educational applications. The present study aims to design and evaluate the vaccination training program through a mobile phone application for the internship of public health students in 2022. MethodsThe current developmental-applied study was carried out among 30 female undergraduate public health students using census sampling method. The information needs and technical capabilities of the program were first determined. A skill-testing station test was taken, and the scores were recorded. The designed application was given to the students, and they were given one month to use it. After that, the same stationary test was taken again, and the scores were compared with those of the first test. Then, the level of user satisfaction with the vaccination training program was collected and analyzed using the fifth version of the user interaction satisfaction (QUIS) questionnaire. The collected data were analyzed by SPSS software version 25 and the Wilcoxon test with a significance level of 0.05. ResultsThe students’ average performance scores in vaccination skills increased from 17.56 ± 6.24 to 60.4 ± 2.15 after using the EDU_VACCINE application (p < 0.05). The average overall satisfaction score of the application was 117.86 ± 10.76 (p < 0.05). ConclusionAccording to the results, the average scores related to the vaccination performance of the students as well as the satisfaction of the EDU_VACCINE application are at a high level. Respectively, ‘ease of working with the application’ and its being ‘offline’ garnered the highest level of satisfaction, and these factors can make education through the application more popular among different educational fields.

Electrical Heating of Carbon Textile Reinforced Concrete—Possible Effects on Tensile Load-Bearing Behavior

Carbon-textile-reinforced concrete (CTRC) is currently used as a high-performance composite material in the construction industry, comprising concrete and a non-metallic reinforcement. In addition to remarkable material properties such as tensile-load-bearing behavior, durability and density, this innovative material features high electrical conductivity, offering the potential for electrical heat generation within building components. This paper contributes to the field by exploring the unique combination of properties exhibited by carbon-textile reinforcements (CTR) electrically heated up to 80 °C. The impact of the electrical heating of CTR was evaluated by conducting stationary tests on load-bearing behavior. The tests were conducted on two different CTRs: one impregnated with polystyrene, and the other with epoxy resin additionally surface-modified with quartz sand. In order to quantify the influence of individual material parameters, tensile tests were conducted on the components comprising CTR and mortar, as well as the composite CTRC. The analysis focused on electrically heated carbon-textile reinforcements, comparing them through experiments conducted at varying ambient temperatures. This study presents pioneering findings on heated CTRC, determining that electrical heating decreases tensile strength with increasing temperature for the investigated reinforcement materials. The softening of the impregnation materials proved to be a decisive factor. This interdisciplinary approach bridges materials science with thermal management in construction, offering insights into the practical applications of CTR in innovative building designs.

Estimation of Anxiolytic Efficacy of Carica Papaya L. Seeds using Experimental Animal Models of Anxiety

Background: Natural remedies have garnered global recognition for their therapeutic applications, supported by their unique nutritional and bioactive compositions. Among these, Carica papaya L., commonly known as papaya, has been historically valued not only for its nutritional benefits but also for its medicinal properties. The diverse chemical compositions of its leaves, seeds, and fruit contribute to their varied therapeutic uses. Objective: This study aims to investigate the anxiolytic effects of aqueous extracts from Carica papaya L. seeds using various experimental animal models of anxiety. Methods: Aqueous extracts of Carica papaya L. seeds were administered to Albino mice in a controlled laboratory setting. The anxiolytic effects were evaluated using four experimental models: the open field test, head dip test, cage crossing, and stationary rod test. Results: The administration of papaya seed extract resulted in a statistically significant reduction in peripheral square crossings by 40% and cage crossings by 50% in the open field and cage crossing tests, respectively. The head dip test saw a decrease in head pokes by 45%, and the time to cross the stationary rod was reduced by 30% compared to controls. Conclusion: The findings indicate that Carica papaya L. seeds possess pronounced anxiolytic properties, suggesting their potential utility as a natural adjunct therapy in managing anxiety disorders.

Mathematical Analysis of the Wind Field Characteristics at a Towering Peak Protruding out of a Steep Mountainside

Wind field characteristics in a complex topography are significantly influenced by the nature of the surrounding terrains. This study employs onsite measurements to investigate the wind field characteristics at a towering peak protruding out of a steep mountainside, where butterfly−lookalike landscape platform will be constructed; the impact of the surrounding topography on the wind flow is highlighted. The results showed that the blocking effect of the mountains in the mountainous side of the valley caused a significant drop in the mean wind speed from that direction. The stationary test (reverse arrangement test) indicated that the wind speed had a strong nonstationary characteristic, necessitating the employment of a steady and nonstationary wind speed model to assess the wind turbulence characteristics. The three directions’ wind turbulence integral scales were critically influenced by the occurrence of the wind speedup effect, unexpectedly resulting in the vertical turbulence integral scale being the greatest of the three. Furthermore, the measured wind turbulence properties under both wind speed models showed certain variations from the recommended specifications. Consequently, the impact of the local terrain and the speedup effect on the wind characteristics must be thoroughly evaluated to ensure the structural stability of structures installed at a similar topography.

Dynamic responses of the floatover system with nonstationary mating processes: An experimental study

Floatover method has been widely applied in the installation of both fixed and floating platforms, which has the advantages of high efficiency, economy, and large lifting capacity compared with other installation methods. Few studies could numerically and experimentally simulate the continuous load transfer process which shows significant nonstationary characteristics. This paper conducts experimental research on the nonstationary mating process of the floatover system. The ballasting system based on the control logic of feedback adjustment is developed to adjust the draft and inertia properties of the floatover vessel, and the validation tests are conducted to verify the feasibility and reliability of the system. The load buffer devices are designed carefully and the piecewise linear spring simulation method is applied to simulate the nonlinear stiffnesses of the elastic cushion. The stationary model for 0% and 100% load transfer stages and the nonstationary model for continuous load transfer process are established and tested in the model tests, and the dynamic responses are analyzed by using statistical and spectral methods respectively. Stationary model tests indicate that the spectral characteristics and distribution of LMU (Leg Mating Unit) dynamic loads in transverse symmetric positions are similar, and the statistical values are also relatively close under different wave heads. The nonstationary dynamic responses are segmented according to the physical process, time-frequency spectrum and piecewise statistics diagram to find the critical stage. The greatest dynamic load occurs in the intermediate stage of the mating process when the larger stiffness of the LMU acts and the steel-to-steel contact will also occur.

ECG signal quality in intermittent long-term dry electrode recordings with controlled motion artifacts.

Wearable long-term monitoring applications are becoming more and more popular in both the consumer and the medical market. In wearable ECG monitoring, the data quality depends on the properties of the electrodes and on how they interface with the skin. Dry electrodes do not require any action from the user. They usually do not irritate the skin, and they provide sufficiently high-quality data for ECG monitoring purposes during low-intensity user activity. We investigated prospective motion artifact-resistant dry electrode materials for wearable ECG monitoring. The tested materials were (1) porous: conductive polymer, conductive silver fabric; and (2) solid: stainless steel, silver, and platinum. ECG was acquired from test subjects in a 10-min continuous settling test and in a 48-h intermittent long-term test. In the settling test, the electrodes were stationary, whereas both stationary and controlled motion artifact tests were included in the long-term test. The signal-to-noise ratio (SNR) was used as the figure of merit to quantify the results. Skin-electrode interface impedance was measured to quantify its effect on the ECG, as well as to leverage the dry electrode ECG amplifier design. The SNR of all electrode types increased during the settling test. In the long-term test, the SNR was generally elevated further. The introduction of electrode movement reduced the SNR markedly. Solid electrodes had a higher SNR and lower skin-electrode impedance than porous electrodes. In the stationary testing, stainless steel showed the highest SNR, followed by platinum, silver, conductive polymer, and conductive fabric. In the movement testing, the order was platinum, stainless steel, silver, conductive polymer, and conductive fabric.

The Effect of Institusional Ownership, Managerial Ownership, Profitability and Audit Quality on Tax Agressivity

The purpose of this study is to analyze the causality relationship, which explains the independent variables consisting of institutional ownership, managerial ownership, profitability and audit quality against the dependent variable of tax aggressiveness. The data analysis of this research is quantitative analysis and uses Eviews software. EViews is software used for statistical analysis and econometrics. EViews allows users to process data, test hypotheses, and create statistical models for data analysis. EViews methods include the use of time series and cross-sectional data to perform regression analysis, multivariate analysis, causality testing, and data stationary testing. EViews can also be used to design, test, and estimate econometric models such as linear regression models, autoregressive models, and mobile autoregressive models. The results of this study show that the pattern of data that has been collected and the results of testing that has been carried out using Eviews 12 with the panel data regression analysis method show that first, institutional ownership has a negative and significant effect on tax aggressiveness. Second, managerial ownership has a significant negative effect on tax aggressiveness. Third, profitability has a significantly positive effect on tax aggressiveness. Fourth, audit quality has a significant negative effect on tax aggressiveness. Keywords: institutional ownership, managerial ownership, profitability and quality checks on tax aggressiveness

Innovative stearic acid-in-silicone oil (o/o) phase change material lubricating emulsions (PCMLEs): Thermo-rheological and tribological properties

This paper analyses the feasibility of using novel non-aqueous stearic acid-in-silicone oil (o/o) phase change material lubricating emulsions (PCMLEs). The novel use of these dispersions with heat storage capacity for lubricating applications can be considered a new approach since they have not yet been used for such purposes. In this study, PCMLEs consist of stearic acid, with a melting point of roughly 69 °C, as a dispersed phase change material in a continuous silicone oil medium. Samples were prepared by mixing different phase ratios, by high-shear processing and stabilised by a constant concentration of a silicone-based non-ionic surfactant. Taking into consideration the ability of stearic acid to absorb latent thermal energy during machinery operation, the potential application in lubrication has been assessed by means of stationary and temperature ramp friction tests. Moreover, the effect of the phase transition on the PCMLEs’ rheological response has been analysed through stationary flow tests and frequency sweeps within the linear viscoelastic range at constant temperatures, below (40 °C) and above (80 °C) the melting process of the disperse phase. Additionally, their thermal properties and morphology were also studied through X-ray diffraction measurements (XRD), differential scanning calorimetry (DSC) and polarised optical microscopy. As a result, the reported rheological properties and microstructure led to the enhancement in tribological characteristics of PCMLEs since a significant reduction in the friction factor is evidenced, within the whole temperature range, when compared to the silicone oil.

Changes in Body Composition and Physical Performance after a Six-Week International Tour in Young Chilean Female Tennis Players.

Junior tennis players travel a lot to play tennis tournaments; this causes them to spend a lot of time away from their homes and disrupts their training, which could reduce their performance and increase the risk of injury. The purpose of this study was to analyze the changes in physical performance and body composition after a six-week international tour in young Chilean female tennis players. Thirty young female tennis players (15.4 ± 0.6) participated in this study. Body weight, skinfolds, and perimeters were measured. Body fat percentage (BFP) and skeletal muscle mass (SMM) were calculated. For physical performance, 5 m sprint, the 505 with stationary start test (505 test), the pro-agility test, countermovement jump (CMJ), and medicine ball throw (MBT) were evaluated. The results show a significant increase in BFP and decrease in SMM (p < 0.01; d = -0.18 and 0.19, respectively). In terms of physical performance, 5 m sprint, the 505 test (p < 0.01; d = -0.95 and -0.95, respectively), CMJ, MBT, and HJ significantly decreased post-tour (p < 0.05; d = 0.96, 0.89 and 0.47, respectively). We conclude that, after a six-week international tour, there were changes in body composition and a significant decrease in 5 m sprint, the 505 test, CMJ, and MBT.

Influence of space availability on measures of fear in conventional broiler chickens

Many of the fear tests used in the welfare assessments of broiler chickens assume that birds will withdraw from a given stimulus if they are fearful. However, fear test responses may also depend on the amount of space available in the broilers’ environment. As broiler chickens grow, the available space decreases, which, together with a decline in walking ability, may bias the results of fear tests. In the present study, we aimed to examine the relationship between space availability and measures of fear in broiler chickens. We hypothesized that broilers kept in pens with lower space availability would show reduced withdrawal in two movement-dependent fear tests, the stationary person test (SPT) and the novel object test (NOT), as space restrictions would limit the birds’ ability to move away. Fast-growing broilers (Ross 708) were housed at similar target stocking densities (34 kg/m2) until 27 days of age, after which an experimental intervention was introduced in which half of the pens were provided with additional space, reducing the target stocking density to 16 kg/m2. The fear tests were conducted when the birds were 21, 27 (before the change in space availability), 29, and 37 days old. Statistical analyses were performed in R using Generalized Additive Models. We found no effect of space availability on the measures of the SPT (P = 0.32). Space availability seemingly had a temporary effect on the measures of the NOT, as birds housed in the larger pens (16 kg/m2) showed increased withdrawal compared to the birds housed in the smaller pens (34 kg/m2) at 29 days of age (P = 0.04). However, no difference was found at 37 days of age (P = 0.63), and, therefore, we speculate whether the temporary effect at 29 days of age was due to the novelty of the environment rather than due to increase in space availability per se. We conclude that space availability had no effect on the outcome of the SPT and that it, overall, had no lasting effect on the outcome of the NOT. We speculate whether our findings might be explained by our chosen levels of stocking density for the smaller pens, as these may not have been sufficiently high to limit the birds’ ability to respond to the fear tests used, i.e. the birds, although space restricted, still had the option of being outside of proximity of the presented stimuli.

Permanent VS Transitory Shocks to Electricity Consumption: Panel Evidence from 19 African Countries

ABSTRACT: Considering Africa's increasing electricity demands and the pivotal role of electricity in socio-economic development, this study addresses a research gap in understanding the stochastic properties of per capita electricity consumption in African contexts. Through examining the integration properties of per capita electricity consumption across 19 African countries, the research determines whether 'shocks' yield transitory or permanent effects, aiding policy formulation and future demand forecasting. Annual electric power consumption data (1971 – 2014) (kWh per capita) from the WDI across 19 African countries are used. Our methodology starts with formally testing for cross-sectional dependence (CSD) using various tests to avoid potential size distortions. Subsequently, we employ the novel panel stationarity test of Nazlioglu and Karul (2017), a Fourier KPSS panel stationarity test. The robustness of the analysis is enriched by incorporating the Hadri and Kurozumi (2011) panel stationarity test and Nazlioglu et al. (2021) new panel stationary tests. The CSD test results reveal mutual dependency in electricity consumption among the sampled African countries, underscoring the need for a panel testing methodology that accommodates CSD. The results of the panel stationarity tests that allow CSD and structural breaks—specifically, the Nazlioglu and Karul (2017) test, which models structural breaks as a gradual process—reject the null hypothesis of trend stationarity for both single frequencies, i.e., k =1, and 2. Similarly, all new, complementary panel stationarity tests from Nazlioglu et al. (2021) reject the null hypothesis of stationarity for both frequencies. Collectively, the outcomes from various panel stationarity tests present strong evidence of nonstationary per capita electricity consumption within the sampled African countries. Additionally, the Nazlioglu and Karul panel stationarity test enables an analysis of the individual Fourier KPSS test for cross-sectional units in the panel. Of the 19 countries, only Togo does not reject the null hypothesis of stationarity for both frequencies. These individual country results align with the panel outcomes, providing compelling evidence for the nonstationarity of the per capita electricity consumption series across the investigated African nations. Accordingly, shocks to electricity consumption will have permanent effects, indicating that per capita electricity consumption will not return to its pre-shock equilibrium path. In this case, demand or consumption stabilizing policies will have long-run effects.