Proportionality Constant Research Articles

Access to care following injury in Northern Malawi, a comparison of travel time estimates between Geographic Information System and community household reports

Introduction: Injuries disproportionately impact low- and middle-income countries like Malawi. The Lancet Commission on Global Surgery's indicators include the population proportion accessing laparotomy and open fracture care, key trauma interventions, within two hours. The "Golden Hour" for receiving facility-based resuscitation also guides injury care system strengthening. Firstly, we estimated the proportion of the local population able to reach primary, secondary and tertiary facility care within two and one hours using Geographic Information System (GIS) analysis. Secondly, we compared community household-reported with GIS-estimated travel time.Methods: Using information from a Health and Demographic Surveillance Site (Karonga, Malawi) on road network, facility location, and local staff-estimated travel speeds, we used a GIS-generated friction surface to calculate the shortest travel time from all households to each facility serving the population. We surveyed community households who reported travel time to their preferred, closest, government secondary and tertiary facilities. For recently injured community members, time to reach facility care was recorded. To assess the relationship between community household-reported travel time and GIS-estimated travel time, we used linear regression to generate a proportionality constant. To assess associations and agreement between injured patient-reported and GIS-estimated travel time, we used Kendall rank and Cohen's kappa tests.Results: Using GIS, we estimated 79.1% of households could reach any secondary facility, 20.5% the government secondary facility, and 0% the government tertiary facility, within two hours. Only 28.2% could reach any secondary facility within one hour, 0% for the government secondary facility. Community household-reported travel time exceeded GIS-estimated travel time. The proportionality constant was 1.25 (95%CI 1.21–1.30) for the closest facility, 1.28 (95%CI 1.23–1.34) for the preferred facility, 1.45 (95%CI 1.33–1.58) for the government secondary facility, and 2.12 (95%CI 1.84–2.41) for tertiary care. Comparing injured patient-reported with GIS-estimated travel time, the correlation coefficient was 0.25 (SE 0.047) and Cohen's kappa was 0.15 (95%CI 0.078–0.23), suggesting poor agreement.Discussion: Most households couldn't reach government secondary care within recognised thresholds indicating poor temporal access. Since GIS-estimated travel time was shorter than community-reported travel time, the true proportion may be lower still. GIS derived estimates of population emergency care access in similar contexts should be interpreted accordingly.

Modeling transverse momentum exchange in partially vegetated flow

In this study, theoretical and experimental methods are applied to investigate streamwise velocity profiles and transverse momentum exchange in the quasi-equilibrium region in partially vegetated channels. A new eddy viscosity model is proposed to model the transverse momentum exchange in consideration of bottom turbulence, stem-scale turbulence, and turbulence induced by coherent structures. Results show that turbulence induced by coherent structures is the dominant contributor to the momentum exchange. The proposed eddy viscosity model can be well applied for different setups by varying only one proportionality constant (ξ), which is inversely proportional to the canopy drag (CDa). The lateral distribution of eddy viscosity is also well predicted and shows a peak just outside the canopy. By assuming the canopy as a rough wall and setting the zero-plane displacement within the canopy to the distance of penetration width, we find that the lateral profiles of the mean streamwise velocity in the outer shear layer follow logarithmic curves. A quantitative relationship between roughness length and canopy drag (CDa) is, thus, determined similar to that in turbulent rough-wall boundary layers.

Evaluation of flocculation performance of polysaccharide-protamine complex flocculant by flocculation model

Flocculation experiments were conducted with three kinds of polysaccharide-protamine complex flocculants. Alginate, κ-carrageenan, and pectin were used as typical polysaccharides. The polysaccharides have carboxyl and sulfate groups, and it can be considered that the polysaccharides could bind basic protein, such as protamine, at around the neutral pH (pH 6.5–7.5). The relative absorbance was used as an index of the flocculation efficiency. Influences of the mass ratio (polysaccharide/protamine) and dosage of the complex flocculants on the flocculation efficiency were investigated. Judging from the results, the optimum mass ratio of polysaccharide and protamine was found as 0.4 for alginate and 1.0 for κ-carrageenan and pectin. The previously proposed flocculation model was applied to the data successfully and the proportional constant, stoichiometric coefficients, and the equilibrium adsorption constant regarding as forming flocs were determined by fitting to the data and using a least square method. Judging from the model parameters, the total number of acidic groups, and the molecular weight of each polysaccharide, the alginate-protamine complex could be the most effective flocculant.

A ½ spin fiber model for the electron

The Standard Model and Quantum Mechanics studies the quantum world as a collection of probabilistically interacting particles and does not tell us what a single isolated particle like the electron is, thus its intrinsic detailed field mechanics and how these are generating its intrinsic property values like charge, spin, magnetic moment and handedness. We herein are translating these intrinsic physical properties of the electron to a novel 4-dimensional (i.e. three spatial plus one temporal) fiber spinor and showing their possible deeper correlation and interconnection combined under a single energy manifold. From physical quantum emulation observations, mathematical analysis and Wolfram Alpha parametric polar simulations and mathematical 4D animations we calculated a fiber model for the dressed bare mass electromagnetic field of the electron that results to all of its known measured intrinsic properties. Therefore our model is an intrinsic mechanics model for the electron at rest and shows the possibility that the elementary electron although it has no inner sub-particles, it can posses a specific energy flux manifold. Why an electron is actually a ½ spin geometry, twisted photon. The fine structure constant is explained as a topological feature, proportionality constant, embedded inside our proposed fiber model for the electron. Our novel fiber model opens up a new door on theoretical intrinsic mechanics physics of elementary particles beyond the Standard Model.Â

Dose-dependent Transmissibility of Chromosome Aberrations at First Mitosis after Exposure to Gamma Rays. I. Modeling and Implications Related to Risk Assessment.

The relationship between certain chromosomal aberration (CA) types and cell lethality is well established. On that basis we used multi-fluor in situ hybridization (mFISH) to tally the number of mitotic human lymphocytes exposed to graded doses of gamma rays that carried either lethal or nonlethal CA types. Despite the fact that a number of nonlethal complex exchanges were observed, the cells containing them were seldom deemed viable, due to coincident lethal chromosome damage. We considered two model variants for describing the dose responses. The first assumes independent linear-quadratic (LQ) dose response shapes for the yields of both lethal and nonlethal CAs. The second (simplified) variant assumes that the mean number of nonlethal CAs per cell is proportional to the mean number of lethal CAs per cell, meaning that the shapes and magnitudes of both aberration types differ only by a multiplicative proportionality constant. Using these models allowed us to assemble dose response curves for the frequency of aberration-bearing cells that would be expected to survive. This took the form of a joint probability distribution for cells containing ≥1 nonlethal CAs but having zero lethal CAs. The simplified second model variant turned out to be marginally better supported than the first, and the joint probability distribution based on this model yielded a crescent-shaped dose response reminiscent of those observed for mutagenesis and transformation for cells "at risk" (i.e. not corrected for survival). Among the implications of these findings is the suggestion that similarly shaped curves form the basis for deriving metrics associated with radiation risk models.

Fine Structure Constant Model Demonstrates the Electron Elementary Charge of Having an Intrinsic Manifold

Using our recently published electron’s charge electromagnetic flux manifold fiber model of the electron, described by analytical method and numerical simulations, we show how the fine structure constant is embedded as a geometrical proportionality constant in three dimensional space of its charge manifold and how this dictates the first QED term one-loop contribution of its anomalous magnetic moment making for the first time a connection of its intrinsic characteristics with physical geometrical dimensions and therefore demonstrating that the physical electron charge cannot be dimensionless. We show that the fine structure constant (FSC) α, and anomalous magnetic moment αμ of the electron is related to the sphericity of its charge distribution which is not perfectly spherical and thus has a shape, and therefore its self-confined charge possesses measurable physical dimensions. We also explain why these are not yet able to be measured by past and current experiments and how possible we could succeed.

Sistem Pengatur Tegangan Otomatis : Analisa Peralihan Dengan Pengendali Tunggal Dan Kaskade

This journal describes the design and analysis of the response of a single controller and cascade direct current type of Automatic Voltage Regulator (AVR) system. The direct current AVR system is represented form of a transfer function. For single and cascade controllers, it is designed using a parallel architecture using MATLAB software with predetermined design criteria. The types of controllers used consist of Proportional Differential (PD), Proportional Integral (PI), Proportional Integral Differential (PID), Proportional Differential with First Order Filters in the Differential Section (PDF) and Proportional Integral Differentials with First Order Filters in the Differential Section(PIDF). For the transition analysis, the observed parameters consist of rise time, peak time, steady state time, maximum pass value and peak value. The results of the analysis show that the controllers that meet the design criteria are Proportional Differential (PD) controllers and Proportional Differential controllers with First Order Filters in Differential Sections (PDF) for single controllers and cascade controllers. For a single controller, the value of the Proportional constant (Kp) is 0.6280 and the value of the Differential constant (KD) is 0.1710 for the Proportional Differential (PD) controller. Proportional constant value (Kp) is 0.6130, Differential constant value (KD) is 0.1710 and filter constant value (Tf) is 0.0009 for Proportional Differential controller with First Order Filter in Differential Section (PDF). Cascade controllers and Proportional Differential (PD) controllers, the Proportional constant (Kp) is 1.7300 and the Differential constant (KD) is 0.0242 for the inner circle (C2). Outer ring controller (C1), the proportional constant (Kp) is 179,000 and the Differential constant (KD) is 2.4600. Cascade controllers and Proportional Differential controller types with First Order Filters in the Differential Section (PDF), the Proportional constant (Kp) value is 1.5900, the Differential constant (KD) value is 0.0246, the filter constant value (Tf) is 0.0018 for the inner circumference (C2 ). For the outer ring controller (C1), the Proportional constant (Kp) value is 134,0000, the Differential constant (KD) value is 2.2900 and the filter constant value (Tf) is 0.00008.

A Custom-Made Lower Limb Dynamometer for Assessing Ankle Joint Torque in Humans: Calibration and Measurement Procedures.

Custom-made dynamometry was shown to objectively analyze human muscle strength around the ankle joint with accuracy, easy portability and low costs. This paper describes the full method of calibration and measurement setup and the measurement procedure when capturing ankle torque for establishing reliability of a portable custom-built electronic dynamometer. After considering the load cell offset voltage, the pivotal position was determined, and calibration with loads followed. Linear regression was used for calculating the proportionality constant between torque and measured voltage. Digital means were used for data collection and processing. Four healthy consenting participants were enrolled in the study. Three consecutive maximum voluntary isometric contractions of five seconds each were registered for both feet during plantar flexion/dorsiflexion, and ankle torque was then calculated for three ankle inclinations. A calibration procedure resulted, comprising determination of the pivotal axis and pedal constant. Using the obtained data, a measurement procedure was proposed. Obtained contraction time graphs led to easier filtering of the results. When calculating the interclass correlation, the portable apparatus demonstrated to be reliable when measuring ankle torque. When a custom-made dynamometer was used for capturing ankle torque, accuracy of the method was assured by a rigorous calibration and measurement protocol elaboration.

Chronic stress facilitates bursting electrical activity in pituitary corticotrophs.

Coordination of an appropriate stress response is dependent upon anterior pituitary corticotroph excitability in response to hypothalamic secretagogues and glucocorticoid negative feedback. A key determinant of corticotroph excitability is large conductance calcium- and voltage-activated (BK) potassium channels that are critical for promoting corticotrophin-releasing hormone (CRH)-induced bursting that enhances adrenocorticotrophic hormone secretion. Previous studies revealed hypothalamic-pituitary-adrenal axis hyperexcitability following chronic stress (CS) is partly a function of increased corticotroph output. Thus, we hypothesise that chronic stress promotes corticotroph excitability through a BK-dependent mechanism. Corticotrophs from CS mice displayed significant increase in spontaneous bursting, which was suppressed by the BK blocker paxilline. Mathematical modelling reveals that the time constant of BK channel activation, plus properties and proportion of BK channels functionally coupled to L-type Ca2+ channels determines bursting activity. Surprisingly, CS corticotrophs (but not unstressed) display CRH-induced bursting even when the majority of BK channels are inhibited by paxilline, which modelling suggests is a consequence of the stochastic behaviour of a small number of BK channels coupled to L-type Ca2+ channels. Our data reveal that changes in the stochastic behaviour of a small number of BK channels can finely tune corticotroph excitability through stress-induced changes in BK channel properties. Importantly, regulation of BK channel function is highly context dependent allowing dynamic control of corticotroph excitability over a large range of time domains and physiological challenges in health and disease. This is likely to occur in other BK-expressing endocrine cells, with important implications for the physiological processes they regulate and the potential for therapy. KEY POINTS: Chronic stress (CS) is predicted to modify the electrical excitability of anterior pituitary corticotrophs. Electrophysiological recordings from isolated corticotrophs from CS male mice display spontaneous electrical bursting behaviour compared to the tonic spiking behaviour of unstressed corticotrophs. The increased spontaneous bursting from CS corticotrophs is BK-dependent and mathematical modelling reveals that the time constant of activation, properties and proportion of BK channels functionally coupled to L-type calcium channels determines the promotion of bursting activity. CS (but not unstressed) corticotrophs display corticotrophin-releasing hormone-induced bursting even when the majority of BK channels are pharmacologically inhibited, which can be explained by the stochastic behaviour of a small number of BK channels with distinct properties. Corticotroph excitability can be finely tuned by the stochastic behaviour of a small number of BK channels dependent on their properties and functional co-localisation with L-type calcium channels to control corticotroph excitability over diverse time domains and physiological challenges.

Rougher is more slippery: How adhesive friction decreases with increasing surface roughness due to the suppression of capillary adhesion

Friction originates at the area of real contact which depends on the (changing) surface topography. Observing and measuring the area of real contact at multi-asperity interfaces is difficult, making it challenging to quantitatively study the interplay between the frictional force and surface topography. In this paper, we systematically manipulate surface topography and use a fluorescence microscopy-based contact visualization technique to reveal this interplay. We demonstrate good agreement between elastoplastic boundary element method contact calculations and experimental visualization of the area of real contact. While the area of real contact and thus contact pressure could be varied by a factor of 4 through control of the surface topography, this had only a modest effect on the coefficient of friction (CoF). We do find a small but systematic increase in the proportionality constant between frictional force and normal force (CoF) with decreasing surface roughness. The observation that smoother surfaces have a greater CoF is due to capillary adhesion between the two surfaces. We quantitatively model this behavior using a simple capillary adhesion model without adjustable parameters. Our results provide quantitative insights into the interplay between contact mechanics, friction, and capillary adhesion. A predictive understanding of this interplay is essential to demanding applications such as precision positioning.

A measurement of the mean electronic excitation energy of liquid xenon

Detectors using liquid xenon as target are widely deployed in rare event searches. Conclusions on the interacting particle rely on a precise reconstruction of the deposited energy which requires calibrations of the energy scale of the detector by means of radioactive sources. However, a microscopic calibration, i.e. the translation from the number of excitation quanta into deposited energy, also necessitates good knowledge of the energy required to produce single scintillation photons or ionisation electrons in liquid xenon. The sum of these excitation quanta is directly proportional to the deposited energy in the target. The proportionality constant is the mean excitation energy and is commonly known as W-value. Here we present a measurement of the W-value with electronic recoil interactions in a small dual-phase xenon time projection chamber with a hybrid (photomultiplier tube and silicon photomultipliers) photosensor configuration. Our result is based on calibrations at mathcal {O}(1{-}10,{hbox {keV}}) with internal {^{37}hbox {Ar}} and {^{83text {m}}hbox {Kr}} sources and single electron events. We obtain a value of W={11.5}{} , ^{+0.2}_{-0.3} , mathrm {(syst.)} , hbox {eV}, with negligible statistical uncertainty, which is lower than previously measured at these energies. If further confirmed, our result will be relevant for modelling the absolute response of liquid xenon detectors to particle interactions.

Decomposition dynamics and driving factors of manure in reclaimed soils in coal mining area

Understanding the decomposition dynamics and driving factors of manure in the soil subjected to different reclaimed years could provide theoretical basis to rational utilization of manure and soil fertility improvement in coal mining area. Cattle manure and pig manure were mixed with soils subjected to different reclaimed years (one year, R1; 10 years, R10; and 30 years, R30) at the ratio of manure carbon to soil mass of 4 to 100, so as to examine manure decomposition characteristics using the nylon mesh bag (15 cm deep of soil buried) in the Shanxi coal mine reclamation area, with no manure addition as control (CK). Soil samples were collected at day 12, 23, 55, 218, 281, and 365 to measure the contents of soil manure residual, soil microbial biomass carbon (MBC), and dissolved organic carbon (DOC). The contributions of soil properties, manure properties, and hydrothermal condition to manure decomposition were quantified. The results showed that the decomposition rates of pig manure were significantly higher than cattle manure. The humification coefficient of pig manure (average 46.3%) was lower than that of cattle manure (average 71.7%). The humification coefficient of pig manure was significantly lower in the 30-year reclaimed soil (44.5%) compared to the 1-year and 10-year reclaimed soil (average 47.2%). There was no significant difference in the humification coefficient of cattle manure among the three reclaimed soils. The proportion and decomposition rate constant of labile carbon pool of pig manure and cattle manure were significantly different, with values of 52% and 26%, and 0.00085 and 0.00074 ℃-1, respectively. The positive effect of pig manure on MBC and DOC in reclaimed soil was significantly higher than that of cattle manure over 0-218 days, but no difference over 281-365 days. The magnitude of the enhancement of MBC and DOC in those three reclaimed soils after manure amendments showed a similar trend of R1 >R10 ≈ R30. Results of variance partitioning analysis showed that manure decomposition was mainly controlled by manure properties (17.9%) when considering soil properties, manure properties, and hydrothermal condition. In conclusion, the decomposition of pig manure but not cattle manure was regulated by reclamation year. Cattle manure, with higher humification coefficient than pig manure, was recommended for reclaimed mining area to improve soil fertility.

Exploring the associations between transcript levels and fluxes in constraint-based models of metabolism

BackgroundSeveral computational methods have been developed that integrate transcriptomics data with genome-scale metabolic reconstructions to increase accuracy of inferences of intracellular metabolic flux distributions. Even though existing methods use transcript abundances as a proxy for enzyme activity, each method uses a different hypothesis and assumptions. Most methods implicitly assume a proportionality between transcript levels and flux through the corresponding function, although these proportionality constant(s) are often not explicitly mentioned nor discussed in any of the published methods. E-Flux is one such method and, in this algorithm, flux bounds are related to expression data, so that reactions associated with highly expressed genes are allowed to carry higher flux values.ResultsHere, we extended E-Flux and systematically evaluated the impact of an assumed proportionality constant on model predictions. We used data from published experiments with Escherichia coli and Saccharomyces cerevisiae and we compared the predictions of the algorithm to measured extracellular and intracellular fluxes.ConclusionWe showed that detailed modelling using a proportionality constant can greatly impact the outcome of the analysis. This increases accuracy and allows for extraction of better physiological information.

Mechanical Energy Deposition in Cool Star Atmospheres: Resonant Coupling to Coronal Loops in M Dwarfs

Abstract The efficiency of coronal heating ε(cor) in a star can be quantified by L X/L bol, i.e., the ratio of X-ray luminosity to bolometric luminosity. The efficiency of chromospheric heating in the same star ε(chr) is typically assumed to be proportional to L(Hα)/L bol or L(Ca K)/L bol where the lines Hα and Ca K are often the two strongest emission lines in the visible spectrum: the constant of proportionality (η = ε(chr)/[L(Hα)/L bol] > 1) includes contributions from many other lines emitted by the chromosphere. In the case of the quiet Sun, it has been known for decades that, in the Sun, the efficiency of chromospheric heating is larger by a factor of ε(chr)/ε(cor) > 10 than the efficiency of coronal heating. Over the intervening years, data pertaining to ε(cor) and ε(chr) have been estimated for an increasingly large sample of main-sequence stars with spectral types later than the Sun. These data suggest that among M dwarfs, the efficiency ratio ε(chr)/ε(cor) may in some stars become smaller than in the solar case. The effect of this is such that the value of ε(cor) may become comparable to the value of ε(chr). Here, we seek to understand why coronal heating may be >10 times more efficient (relative to chromospheric heating) in certain M dwarfs than in the Sun. Using data on coronal loop properties in flaring stars, we examine the hypothesis that in M dwarfs, the enhanced efficiency of coronal heating may be related to resonant coupling between coronal loops and the source of mechanical energy in the convection zone.

Numerical Simulations of Variable‐Range Hopping

Numerical simulations of variable‐range hopping in 2D and 3D systems with states localized by the disorder are reviewed. Both interacting and noninteracting systems are considered. After reviewing the main theories for variable‐range hopping, Mott's and Efros and Shkolvskii's, the numerical techniques are presented that are employed for this problem. Existing results are presented and some new ones obtained for this contribution, concentrating on the value of the proportionality constant on the characteristic temperatures of the different conduction laws and on the form of the pre‐exponential factor.

Optimization of the PNG Law for a Dual-Spin Mortar with Fixed Canards

The limited instantaneous overload available and the curved trajectory lead to adaptivity problems for the proportional navigation guidance (PNG) of a guided mortar with a fixed-canard trajectory correction fuze. In this paper, the optimization of a PNG law with gravity compensation is established. Instead of using the traditional empirical method, the selection of the proportional navigation constants is formulated as an optimization problem, which is solved using an intelligent optimization algorithm. Two optimization schemes are proposed for constructing corresponding optimization models. In schemes 1 and 2, the sum squared error between the impact point and target and the circular error probability (CEP), respectively, are taken as the objective function. Monte Carlo simulations are conducted to verify the effectiveness of the two optimization schemes, and their guidance performance is compared through trajectory simulations. The simulation results show that the impact point dispersion can be efficiently reduced under both proposed schemes. Scheme 2 achieves a lower CEP, which is approximately 2.9 m and 2.4 times smaller than that achieved by scheme 1. Moreover, the mean impact point is closer to the target.

Exploration of a singular fluid spacetime

We investigate the properties of a special class of singular solutions for a self-gravitating perfect fluid in general relativity: the singular isothermal sphere. For arbitrary constant equation-of-state parameter w=p/rho , there exist static, spherically-symmetric solutions with density profile propto 1/r^2, with the constant of proportionality fixed to be a special function of w. Like black holes, singular isothermal spheres possess a fixed mass-to-radius ratio independent of size, but no horizon cloaking the curvature singularity at r=0. For w=1, these solutions can be constructed from a homogeneous dilaton background, where the metric spontaneously breaks spatial homogeneity. We study the perturbative structure of these solutions, finding the radial modes and tidal Love numbers, and also find interesting properties in the geodesic structure of this geometry. Finally, connections are discussed between these geometries and dark matter profiles, the double copy, and holographic entropy, as well as how the swampland distance conjecture can obscure the naked singularity.

Evaluation and Comparative Analysis of Speed Performance of Brushless DC Motor using Digital Controllers

Abstract: This paper presents modeling, performance evaluation, and comparative analysis of speed performance of brushless DC motor (BLDCM) by using digital controllers. Speed performance analysis is carried out by using time response specifications which are useful for determining the effectiveness of the digital controllers. The wide spread of BLDCM in many areas due to the advantages of BLDCM over the conventional widely used motors such as induction motor and brushed DC motor. Advantages of BLDCM include higher efficiency, lower maintenance, longer life, reduced losses, single excitation, etc. Controllers are used to improve the transient and steady state speed response of the BLDCM. In many applications conventional PID controller is widely used to control the speed of the BLDCM but the main issue with the conventional PID controller is that it requires manual tuning of the parameters such as proportional, integral, and derivative gain constant. Even though the autotuning methods are available with the PID controller it is not adaptive itself to handle the conditions such as variations in parameters, disturbances in load, etc. In this Paper the Fuzzy-PID controller is used to control the speed of the BLDCM and Transient and steady state speed performance analysis is carried out using conventional PID controller and Fuzzy-PID to showcase the comparative analysis between two controllers. MATLAB/SIMULINK environment is used for modeling of the BLDCM and its drive/control system. Keywords: Brushless DC Motor (BLDCM), Fuzzy Logic Controller (FLC), Modeling of BLDC drive/control system, of PID controller, Transient and steady state analysis

Flow of a Fluid with Pressure-Dependent Viscosity through Variable Permeability Porous Layer

In this work, we consider flow of a fluid with pressure-dependent viscosity down an inclined porous plane with variable permeability that is incorporated in the pressure-dependent drag coefficient. We provide a solution to a recently developed flow model, and study the effects of flow and domain parameters (viscosity control parameter, permeability proportionality constant, and angle of inclination) on the flow characteristics. Suitability of a variable permeability model that considers permeability proportional to the flow velocity is investigated. Results show that large values of the permeability proportionality constant have little or no effects on flow characteristics.

Rancang Bangun Low-Budget Autonomous Quadcopter

Quadcopter is an unstable flying vehicle. The flight controller regulates the rotational speed of the four motors, so that each propeller produces the lift required for the quadcopter to fly stable. It is interesting to know whether the use of generic quadcopter components obtained in the market can be mutually compatible. A stable and controllable quadcopter is a requirement for a quadcopter to fly autonomously. This research focusses on design a low-budget autonomous quadcopter. The research method consists of three main stages. First, the design and build phase of the quadcopter. The main frame and quadcopter arms are designed with a diagonal distance between the rotors of 45 cm. The basic components of the quadcopter are selected which are mutually compatible and assembled on the frame and arms. The flight controller is connected to the GPS, transmitter, and receiver. The autonomous system also involves a ground control system in the form of a Mission Planner. Second, the flight test stage is setting the PID constant so that the quadcopter can fly stable. PID tuning produces proportional constants of 0.088, integrals of 0.016, and derivatives of 0.008. Third, the autonomous flight test stage. The success of autonomous flying is known by analyzing the difference in input waypoint coordinates through the Mission Planner against the results of low-budget GPS receiver readings on autonomous flying missions. GPS accuracy was analyzed by calculating the 2DRMS and CEP values. The best value of 2DRMS = 1.56 meters and CEP = 0.64 meter occurred at Waypoint #2.