Linear Function Of Time Research Articles

A new semi-analytical approach for nonlinear dynamic responses of functionally graded porous graphene platelet-reinforced circular plates and spherical shells

This paper presents the semi-analytical approach for nonlinear dynamic responses of porous graphene platelet-reinforced circular plates (CiPs) and spherical shells (SpSs) resting on the Pasternak foundation in thermal environment. The graphene platelets (GPLs) are distributed in the functionally graded (FG) distribution patterns and uniform distribution pattern through the CiP and SpS thickness direction. The governing equations of the GPL-reinforced structures subjected to time-dependent external pressure respected to the harmonic and linear functions of time are established based on the geometrically nonlinear higher-order shear deformation theory. A simple and effective semi-analytical solution for the considered problem is established using the Euler-Lagrange equations, and the damping viscosity of the foundation can be counted using the Rayleigh dispassion function. The Runge-Kutta method is employed to determine the dynamic responses of the GPL-reinforced structures, while the fundamental frequencies of free and linear vibration, and frequency-amplitude curves are obtained in explicit form. The numerical results obtained reveal that the GPL and porous distributions, geometrical and material properties can significantly affect the frequency-amplitude curves, and dynamic responses of harmonically loaded and linearly loaded structures, specially, the dynamic buckling phenomenon is clearly observable with the SpSs but not with the CiPs.

Comparison of formulas derived from Fourier series solution of diffusion equation

The first Fourier series solution satisfying the boundary condition of zero concentration at the diffusion distance was derived by assuming that the solution consists of a steady-state solution and a transient solution. The first total amount which has passed through the first layer surface was derived from the first Fourier series solution. When the diffusion distance is large, the exponential term in the first total amount cannot be zero. For the sublimation diffusion of disperse dye in paste into polyethylene terephthalate film using the film-roll method, the plot of the first total amount against time was in good agreement with the quadratic regression curve. The second Fourier series solution satisfying the boundary condition of constant concentration at the diffusion distance was derived by assuming that the diffusion distance is the thickness of the first layer. The second total amount which has passed through the second layer surface was derived from the second Fourier series solution and is a linear function of time because the exponential term is zero due to the very small diffusion distance, the thickness of the first layer. The plot of the second total amount against time was in good agreement with the linear regression line. The time-lag formula was derived from the second total amount. The diffusion coefficients determined from the second total amount are much larger than those of the other three types. All four types showed excellent linearity in Arrhenius plot, but the activation energy for the time-lag formula is somewhat greater than the rest.

PERBANDINGAN MODEL REGRESI STRATIFIED COX DAN EXTENDED COX PADA ANALISIS SURVIVAL PENDERITA KANKER PAYUDARA

Breast cancer is a tumor that develops in the breast where cells in the mammary gland divide and develop uncontrollably. Breast cancer is the most common cancer that causes death in women among other cancers. This study aims to determine the factors that affect the survival of breast cancer patients from the METABRIC database. This study was analyzed using survival analysis method. The method that is often used is the Cox proportional hazard model where the proportional hazard assumption must be met. There is variable that do not meet the assumption so that the methods used are stratified Cox and extended Cox. The stratified Cox model overcomes variables that do not meet the assumption by stratifying variables that do not meet the assumption. The extended Cox model overcomes variables that do not meet the assumption by interacting the variables with a time function. The time functions used in this study are linear time functions and logarithmic time functions. Based on the smallest AIC value, the best model is the stratified Cox regression model without interaction. Factors that affect the survival of breast cancer patients from the METABRIC database are tumor size, chemotherapy, stage 1, stage 2, and type of surgery.

Pengaruh Kualitas Ruang Terbuka Hijau terhadap Respon Urban Stress Pengunjung Taman di Provinsi DKI Jakarta

Green open space is an important component in cities that can provide benefits in reducing the negative effects of urban stress. This is an important aspect for the City of Jakarta to reduce the effects of urban stress by improving the quality of green open spaces represented by satisfying parks. The objectives of this research are (1) Knowing the correlation relationship urban stressor to the response urban stress park visitors. (2) Knowing the influence of the quality of green open space on the response urban stress. (3) Determine priorities for developing green open spaces. This research method uses a quantitative approach by taking park samples using proportional sampling with a total sample of 22 parks and a sample of respondents using the linear time function method with a total of 330 park visitors. Data were collected using a questionnaire which was analyzed using the importance performance analysis method and multiple linear regression analysis which was processed using IBM SPSS Statistics 25. To determine priorities for developing green open spaces using spatial analysis using vegetation density, comfort index, and population density which was done by overlapping scoring. (overlay) with ArcGIS 10.8 software. The results of this research found that there was a correlation between several urban stressor variables and the urban stress response variable with a significance value of <0.05 with the highest correlation in the sufficient category, which indicates that the higher the urban stressor, the emotional response and behavioral response will increase. This research shows that there is an influence between the park satisfaction variable on the urban stress response variable with the following regression equation: (1) Ycognitive = 7.462 + 0.044 X1(uses & Activities) + 0.042 X4(Sociability); (2) Yemotion = 13.558 + 0.053 X1(uses & Activities) + 0.040 X2(Access & Linkages) + 0.036 and (3) Ybehavior = 10.010 + 0.041 X4(Sociability) + 0.035 X1(uses & Activities) + 0.031 X3(comfort & image). From the results of the spatial analysis, the highest category area is 52,510.69 ha, which is the second priority for developing green open space.

Joint calibration to SPX and VIX options with signature‐based models

AbstractWe consider a stochastic volatility model where the dynamics of the volatility are described by a linear function of the (time extended) signature of a primary process which is supposed to be a polynomial diffusion. We obtain closed form expressions for the VIX squared, exploiting the fact that the truncated signature of a polynomial diffusion is again a polynomial diffusion. Adding to such a primary process the Brownian motion driving the stock price, allows then to express both the log‐price and the VIX squared as linear functions of the signature of the corresponding augmented process. This feature can then be efficiently used for pricing and calibration purposes. Indeed, as the signature samples can be easily precomputed, the calibration task can be split into an offline sampling and a standard optimization. We also propose a Fourier pricing approach for both VIX and SPX options exploiting that the signature of the augmented primary process is an infinite dimensional affine process. For both the SPX and VIX options we obtain highly accurate calibration results, showing that this model class allows to solve the joint calibration problem without adding jumps or rough volatility.

Pendekatan Travel Cost Method (TCM) Dalam Pengukuran Nilai Ekonomi Kawasan Agrowisata Tuur Ma’asering Di Desa Kumelembuai Kecamatan Tomohon Timur Kota Tomohon

This study aims to estimate the economic value of Agrowisata Tuur Ma’asering using the Travel Cost Method (TCM) approach and to analyze the factors affecting the demand for visits to Agrowisata Tuur Ma’asering. The research was conducted over 3 months, from February to May 2024. Data collection was performed using a survey method, gathering both primary and secondary data. Sampling was done using accidental sampling techniques, with the sample size determined by a linear time function formula, resulting in 58 respondents. The research method employed is quantitative, utilizing the travel cost method (TCM) and multiple linear regression analysis. The results indicate that the economic value of Agrowisata Tuur Ma’asering, calculated using the Travel Cost Method (TCM), is IDR2,027,876,535. This value is derived from the consumer surplus per individual per month of IDR345,759, multiplied by the number of visitors in April 2024, which is 5,865 visitors. Factors influencing the demand for visits to Agrowisata Tuur Ma’asering include travel costs, income, education level, and group size. Factors that do not have a significant impact are travel distance and age.

Impact of warranty and green level of the product with nonlinear demand via optimal control theory and Artificial Hummingbird Algorithm

Due to the current environmental situation and human health, a green manufacturing system is very essential in the manufacturing world. Several researchers have developed various types of green manufacturing models by considering green products, green investments, carbon emission taxes, etc. Motivated by this topic, a green production model is formulated by considering selling price, time, warranty period and green level dependent demand with a carbon emission tax policy. Also, the production rate of the system is an unknown function of time. Per unit production cost of the products is taken as increasing function of production rate and green level of the products. In our proposed model, carbon emission rate is taken as linear function of time. Then, an optimization problem of the production model is constructed. To validate of our proposed model, a numerical example is considered and solved it by AHA. Further, other five metaheuristics algorithms (AEFA, FA, GWOA, WOA and EOA) are taken to compare the results obtained from AHA. Also, concavity of the average profit function and convergence graph of different metaheuristics algorithms are presented. Finally, a sensitivity analysis is carried out to investigate the impact of different system parameters on our optimal policy and reach a fruitful conclusion from this study.

ANALYSIS OF AN INVENTORY MODEL FOR TIME-DEPENDENT LINEAR DEMAND RATE THREE LEVELS OF PRODUCTION WITH SHORTAGE

Objective: The objective of this study is to investigate the continuous-production inventory problem for a single product at a three-level facing a constant deterioration rate. It is anticipated that the customer will make renewal arrangements in accordance with the established and extensively utilized order-up-to policy, and may place orders from two providers with differing prices and levels of consistency. Theoretical Framework: In this study demand is a linear function of time, and the deterioration rate is persistent. In this model, the shortage is allowed, and partial backlogging. It is expected that the backlog rate is influenced by how long it takes to get the next replenishment. It involves aspects from various areas of scientific knowledge to understand the different perceptions contained in the scientific literature on the phenomenon of Industry 4.0. Method: The algorithms for this model have been developed in Mathematica Software 9.0. We examine the effects of several difficulty criteria on the best options regarding manufacturing time and replenishment at the store using analytical analysis. Results and Discussion: Thus, our model offers a novel management insight that aids in achieving the ideal profit level for a production system or business. In reality, we obtain a promising outcome from the numerical case. To compare various solutions, we also carry out very comprehensive numerical experiments. Research Implications: This research aims to detect the best course of action for reducing overall inventory costs and increasing overall income. We also verified that the total cost and commonly optimal time used to interrupt geometric production systems could be analyzed with a constant production model. This approach is particularly relevant for organizations seeking to improve operational efficiency and customer satisfaction through better risk management. Originality/Value: This study contributes to our understanding of how and with whom to collaborate by highlighting the relationships among inventory management, innovation performance, and logistics performance. The value of the study is the contribution it makes to the literature on the cost analysis issues. Therefore, the article can be of benefit to the scientific community with an interest in the study of the subject.

Optimizing inventory dynamics: a smart approach for non-instantaneous deteriorating items with linear time function dependent variable demands and holding costs, shortages with backlogging

Optimizing inventory dynamics: a smart approach for non-instantaneous deteriorating items with linear time function dependent variable demands and holding costs, shortages with backlogging

Estimating Hazard Function through Reliability Function and Empirical Methods

In this research, the reliability functions are applied to estimate the hazard function of four used car components (tires, brakes, lights, engine), which are inspected by aperiodic vehicles inspection (PVI) established in Erbil city, as a specialized company that conducts the annual technical inspection of vehicles to detect the failure component, that either require repair or replace it with a new one. For our purpose, the data about the failure components of a sample of size (50000) cars are obtained from the Erbil traffic directorate, which are annually inspected for 11 years (2010 – 2020) by a (PVI) company. From the available data the reliability function, hazard function, and probability density function of failure time of each component are found by the non-parametric method and the estimated Rayleigh distribution since the failure rates of the components are the linear functions of time, also the comparison between their reliability values have made by the mean absolute error method.

Trends in the Growth of Damage Extents in a Steel Conveyor Belt’s Core

The initial set of four measurements (scans) captures the failures occurring in the core of steel cable conveyor belt segments used in a lignite coal mine in Poland. These measurements utilize the DiagBelt+ magnetic system, enabling the analysis of averaged damage sizes. The scanning results allowed the analysis of complete changes in the failure sizes to a maximum of six different time intervals from 1 to 19 months. The cumulative increase in the length and width of the failure (their total extent in both directions) is a linear function of time. However, the inclination of the selected lines (growth speed) depends on the age of the belt segment at the time of its first scan. It is possible to find the best regression function of slope coefficients for the age of the belt segment. The obtained results are crucial for rational belt management, including reliable short-term forecasts of belt needs with the flow of time, indications of the best moments for belt segment replacements, and estimating the budget of the belting department.

ANALISIS KESEDIAAN MEMBAYAR (WILLINGNESS TO PAY) DENGAN PENDEKATAN CHOICE MODELLING (STUDY KASUS COBAN RONDO DAN COBAN TALUN

This study aims to answer several questions related to the choices made by visitors when choosing to visit between Coban Rondo and Coban Talun and their maximum WTP evaluation for conservation purposes.This study seeks to assess how the main environmental attributes of interest to researchers will determine tourists WTP for conservation purposes.The research approach used in this study is a quantitative approach with a descriptive approach. Determination of the number of samples used in this study is a linear time function. The results of research on the characteristics of respondents, respondents' perceptions, and analysis of factors influencing tourist visits to the Wendit Water Tourism Park using the Individual Travel Cost Method (ITCM) are mostly female with an age range between 21-40 years and the level of education is mostly from undergraduate strata 1 graduates and their equivalents. The results of the Willingnes To Pay calculation of visitors to the progress of the quality of the environment and the Coban Rondo and Coban Talun pariwsata places are Rp. 2,400.00 per person. With the average number of visitors who come to Coban is about 200 in 1 month, the economic value of the two coban will be around Rp.480,000.00 in a month.

USING HIGH-FREQUENCY ASSESSMENTS TO EXPLORE WITHIN-PERSON COUPLING OF PSYCHOLOGICAL STATES AND COGNITION

Abstract From the perspective of traditional assessment approaches, variation in cognitive performance due to participant factors (e.g. mood, fatigue) are treated as part of measurement error. This talk will discuss how high-frequency assessment methods, such as ecological momentary assessment (EMA), can be leveraged to capture meaningful signal from variation in cognitive performance. This approach will be used to explore fluctuations in thought valence and levels of arousal as short-term mechanisms for change in working memory and processing speed performance. Participants (n = 265, aged 25-65, 64.9% female) completed a 14-day measurement burst that included five EMAs per day. Each EMA included self-report measures of current thought valence (pleasant-unpleasant) and level of arousal (sleepy/tired-alert/active), as well as two brief cognitive tasks. We use multi-level modelling to disaggregate between- and within-person effects of thought valence and arousal, and to examine within-person coupling with performance on each of the cognitive tasks. Models also include demographic and contextual covariates (e.g. current location), as well as linear and quadratic functions of time and session number to account for time of day and retest effects. We found that at moments when individuals were experiencing more unpleasant thoughts than usual for them, they also made more errors on the working memory task. Additionally, at moments where individuals were feeling more sleepy/tired than usual for them, they performed more slowly on the processing speed task. These results will be discussed from the perspective of using models of within-person coupling to understand short-term mechanisms for cognitive change.

Assessment of visitor perceptions and economic valuation of Tengket Beach attractions

Tengket Beach has an unspoiled beauty, with stretches of fine white sand as the main visitor attraction. However, the village government and surrounding communities have not been interested in managing this potential. Therefore, this study aimed to determine visitor perceptions, the factors influencing the number of visits, and Tengket Beach tourism’s economic value. Samples were determined using the linear time function formula. The data collected were further analyzed by descriptive qualitative, multiple linear regression, and travel cost methods. The results showed that Tengket Beach is perceived as unattractive based on its accessibility and facilities. Based on accessibility indicators, 96.7% of visitors stated that Tengket Beach was not feasible. Meanwhile, based on facility criteria, only 20% of visitors stated that the place had good facilities. Other findings show that most visitors explained that the beach is quite interesting regarding its attractiveness. The results also showed that travel costs negatively affect visits, while accessibility and facilities have a positive effect. Additionally, the economic value of the beach is IDR5,890,560,000 per year. This is an indicator that Tengket Beach has the potential to be used as an economic resource for the surrounding community.JEL Classification C26; I26; Q51

PENGARUH CONTENT MARKETING MEDIA SOSIAL INSTAGRAM TERHADAP MINAT BELI KONSUMEN PADA USAHA YOURGOOD

Utilization of information technology that is increasingly accessible is one of the strategies for entrepreneurs to market their products. YourGood business is one of the Small and Medium Enterprises (SMEs) by presenting smoothies yogurt products and using social media as a marketing medium, one of which is content marketing through Instagram social media as a marketing strategy, content marketing is one of the most important marketing strategies currently being used by YourGood business. The purpose of this study is to test as an illustration how the role or influence of the contribution of content marketing through Instagram social media run by YourGood business on consumer buying interest, this research is included in the type of explanatory research method with a quantitative approach and using non-probability sampling with purposive sampling with a total of 100 respondents using a linear time function to determine the number of samples. Researchers used normality test analysis, t test, F test and multiple linear regression using Microsoft Excel 2019 software. The results stated that there was a correlation between marketing Instagram social media content and the buying interest of YourGood business consumers by 62.6%. Then the variable that has the greatest value is the persuasion variable of 47%. So that the content marketing strategy that can be carried out by YourGood business is to present content with product quality information and build trust in consumers and be carried out consistently and attractively so that the content marketing strategy will be able to increase consumer buying interest.Keywords: Content Marketing, Purchase Intention, Digital Marketing, Instagram.

Structure optimization and operation characteristics of metal gas storage device based on compressed air energy storage system

Compressed air energy storage (CAES) is a key technology for promoting the replacement of fossil fuels with renewable energy. Currently, CAES systems typically require an underground salt cavern, which is limited by geological and geographical conditions. To promote the rapid popularization of CAES, there is an urgent need to develop new gas storage devices with flexible layouts. Metal pressure vessel as a gas storage device is concerned with the benefits of high storage pressure and reliable operation. Considering both strength and fatigue, this study conducted a structural optimization of Tank-D2000 and Pipe-D400 to achieve the design operating life with the minimal quality. Furthermore, the optimized structure was used to study the operating characteristics of the gas storage device by the multi-domain fluid–solid thermal coupling method and the real gas model. The results indicated that the internal convective heat transfer coefficient of the gas storage device was a linear function of time during operation, whereas the external natural convective heat transfer coefficient almost remained constant. The pressure distribution was uniform; however, the temperature difference was large, particularly for D400. Analysis and prediction based on the theory of the polytropic process showed that the polytropic index of D400 was lower than that of D2000, so the heat transfer of D400 was more adequate and the effective capacity of gas storage device under the designed operating pressure range was larger. With an increase in flow, polytropic index increased and was lower at energy storage than at energy release. The pressure prediction error was basically within the range of ±4 %, and the temperature prediction error was within the range of ±3 %.

Estimating APC Model Parameters for Dynamic Intervals Determined Using Change-Point Detection in Continuous Processes in the Petrochemical Industry

Several papers have proven that advanced process controller (APC) systems can save more energy in the process than proportional-integral-differential (PID) controller systems. Therefore, implementing an APC system is ultimately beneficial for saving energy in the plant. In a typical APC system deployment, the APC model parameters are calculated from dynamic data intervals obtained through the plant test. However, depending on the proficiency of the APC engineer, the results of the plant test and the APC model parameters are implemented differently. To minimize the influence of the APC engineer and calculate universal APC model parameters, a technique is needed to obtain dynamic data without a plant test. In this study, we utilize time-series data from a real petrochemical plant to determine dynamic intervals and estimate APC model parameters, which have not been investigated in previous studies. This involves extracting the data of the dynamic intervals with the smallest mean absolute error (MAE) by utilizing statistical techniques such as pruned exact linear time, linear kernel, and radial basis function kernel of change-point detection (CPD). After that, we fix the hyper parameters at the minimum MAE value and estimate the APC model parameters by training with the data from the dynamic intervals. The estimated APC model parameters are applied to the APC program to compare the APC model fitting rate and verify the accuracy of the APC model parameters in the dynamic intervals obtained through CPD. The final validation of the model fitting rates demonstrates that the identification of the dynamic intervals and the estimation of the APC model parameters through CPD show high accuracy. We show that it is possible to estimate APC model parameters from dynamic intervals determined by CPD without a plant test.

Delayed Dynamics with Transient Resonating Oscillations

Recently, we have studied a delay differential equation which has a coefficient that is a linear function of time. The equation has shown the oscillatory transient dynamics appear and disappear as the delay is increased between zero to asymptotically large delay. We here propose and study another equation that shows similar transient oscillations. It has an extra exponential gaussian factor on the delayed feedback term. It is shown that this equation is analytically tractable with the use of the Lambert $W$ function. This equation is also studied numerically to confirm some of the properties inferred from the analytical solution. We also have found that the amplitude of transient oscillation changes and goes through a maximum as we increase the value of the delay. In this sense, the proposed equation is one of the simplest dynamical equations that brings out a resonant behavior without any external oscillating inputs.

Social Study of Tourism Perceptions in Idaman Mangrove Ecotourism of Balang Baru Village, Tarowang District, Jeneponto Regency

This study aims to analyze the perceptions of visitors towards the existence of the Idaman Mangrove Ecotourism object. This research is a survey research using qualitative and quantitative approaches using questionnaire tools. This study was survey research by a qualitative and quantitative approach using a questionnaire tool. This research was done in Idaman Mangrove Ecotourism (IME) in Balang Baru Village, Tarowang District, Jeneponto Regency, South Sulawesi, Indonesia, from June to August 2020. The Non-physical aspects used the linear time function method for the tourists visiting IME. The number of visitor respondents was 40. The data were analyzed for social aspects towards perceptions of tourism using a Likert scale. The research results indicated that tourism perception belongs to the excellent category with 60%. The existence of mangrove ecotourism shows something unique and has a nature-based attraction, adequate facilities and infrastructure, and the comfort of activities that are good enough to meet the wishes of visitors.

Optimum, Suboptimal and Solar Sailing Orbital Maneuvers for a Spacecraft Orbiting the Earth

The present research performs numerical studies to search for the best maneuvers, from the point of view of minimum time, to make adjustments in the semi-major axis, eccentricity and inclination of a spacecraft traveling around the Earth. For those maneuvers, low thrust propulsion is used under optimal and sub-optimal assumptions, to verify the main differences in terms of transfer time. In addition, solar sail dynamics is used. The spacecraft is assumed to have a propulsion with a fixed magnitude and that the control is based on choosing the direction of the propulsion. It is found that optimal control gives the minimum transfer time, while sub-optimal control restricted the control to follow a predescribed function, which is assumed to be a constant or linear function in time. Finally, solar sails present themselves as an option where fuel is a critical factor, given their much longer maneuver duration, but with a zero fuel consumption. The numerical-analytical modeling of optimization methods developed in this study can break any type of symmetry in the solutions. In turn, they can increase their energetic efficiency. The present research compares those results in detail, in particular looking at the transfer time in all cases studied.