MODEL KATASTROFI UNTUK PERFORMANSI KERJA: CUSP ATAU SWALLOWATIL?

Katastrofi, merupakan bagian dari teori singularitas dan bifurkasi, secara umum merupakan kajian yang mempelajari transisi, diskontinuitas, dan perubahan mendadak secara kualitatif. Dalam kajian terdahulu, telah digunakan model dasar katastrofi yaitu Cusp untuk mempelajari perilaku kecerdasan intelektual, Intelligence Quotient (IQ). IQ dipandang sebagai variabel keadaan sedangkan aspek-aspek dari IQ yaitu Praktis-Kongkrit (PK) dan Verbal-Teoretis (VT) sebagai variabel kontrol. Data yang ada mendukung model Cusp. Model Cusp memprediksi terjadinya sebuah ‘lompatan’ dari satu level kecerdasan ke level kecerdasan yang lain karena perubahan salah satu aspeknya.. Dalam tulisan ini, akan dikembangkan model performansi kerja JF yang diduga berkorelasi dengan tiga komponen kecerdasan yaitu IQ, Emotional Quotient (EQ), dan Adversity Quotient (AQ). Studi kajian data memperlihatkan ketiga faktor IQ, EQ, dan AQ, merupakan indikator yang tidak berkorelasi. Hasil ini mengarahkan pada pengambilan ketiganya menjadi variabel kontrol dan performansi kerja JF sebagai variabel keadaan. Dengan tiga variabel control, model katastrofi yang bersesuaian adalah Swallowtail. Dalam penelitian ini, akan dikerjakan beberapa hal spesifik model Swallowtail yang berkaitan dengan pemodelan performansi kerja yaitu proses pemodelan, estimasi parameter, validasi model, dan interpretasi model. Diharapkan peneltian ini akan menghasilkan sesuatu yang signifikan dalam tinjauan kembali terhadap kurikulum pendidikan nasional yang nantinya akan menghasilkan manusia Indonesia dengan performansi kerja optimal. Kata kunci : performansi kerja, variabel keadaan dan variabel control, model Cusp dan model Swallowtail

SEQUENTIAL NON-LINEAR MODEL UPDATING

The Ensemble Kalman Filter (EnKF) has become a popular method in reservoir modeling. Several publications have demonstrated the use of EnKF, and suggested further developments of the method. In this paper, a constant flow rate no flow bounded reservoir is used to explore the applicabity of EnKF. The reservoir modeling and the solution will be discussed and play a role as reservoir simulator. The sequential updating will be discussed and implemented in reservoir modeling. The conclusion is that EnKF can provide satisfactory results compared with traditional reservoir simulation updating method

Approximate Solutions of Linearized Delay Differential Equations Arising from a Microbial Fermentation Process Using the Matrix Lambert Function

In this paper we present approximate solutions of linearized delay differential equations using the matrix Lambert function. The equations arise from a microbial fermentation process in a metabolic system. The delay term appears due to the existence of a rate-limiting step in the fermentation pathway. We find that approximate solutions can be written as a linear combination of the Lambert function solutions in all branches. Simulations are presented for three cases of the ratio of the rate of glucose supply to the maximum reaction rate of the enzyme that experienced delay. The simulations are worked out by taking the principal branch of the matrix Lambert function as the most dominant mode. Our present numerical results show that the zeroth mode approach is quite reliable compared to the results given by classical numerical simulations using the Runge-Kutta method

ARTIFICIAL NEURAL NETWORK APPROACH FOR THE IDENTIFICATION OF CLOVE BUDS ORIGIN BASED ON METABOLITES COMPOSITION

This paper examines the use of an artificial neural network approach in identifying the origin of clove buds based on metabolites composition. Generally, large data sets are critical for an accurate identification. Machine learning with large data sets lead to a precise identification based on origins. However, clove buds uses small data sets due to the lack of metabolites composition and their high cost of extraction. The results show that backpropagation and resilient propagation with one and two hidden layers identifies the clove buds origin accurately. The backpropagation with one hidden layer offers 99.91% and 99.47% for training and testing data sets, respectively. The resilient propagation with two hidden layers offers 99.96% and 97.89% accuracy for training and testing data sets, respectively

FUNGSI WRIGHT SEBAGAI SOLUSI ANALITIK PERSAMAAN DIFUSI-GELOMBANG FRAKSIONAL PADA MEDIA VISKOELASTIS

A fractional diffusion-wave equations in a fractional viscoelastic media can be constructed by using equations of motion and kinematic equations of viscoelasticmaterial in fractional order. This article concerns the fractional diffusion-wave equations in the fractional viscoelastic media for semi-infinite regions that satisfies signalling boundary value problems. Fractional derivative was used in Caputo sense. The analytical solution of the fractional diffusion-wave equation in the fractional viscoelastic media was solved by means of Laplace transform techniques in the term of Wright function for simple form solution. For general parameters, Numerical Inverse Laplace Transforms (NILT) was used to determine the solution

A Singular Perturbation Problem for Steady State Conversion of Methane Oxidation in a Reverse Flow Reactor

The governing equations describing methane oxidation in a reverse flow reactor are given by a set of convective-diffusion equations with a nonlinear reaction term, where temperature and methane conversion are dependent variables. In this study, the process is assumed to be a one-dimensional pseudohomogeneous model and takes place with a certain reaction rate in which thewhole process ofthereactor is still workable. Thus, the reaction rate can proceed at a fixed temperature. Under these conditions, we can restrict ourselves to solving the equations for the conversion only. From the available data, it turns out that the ratio of the diffusion term to the reaction term is small. Hence, this ratio is considered as a small parameter in our model and this leads to a singular perturbation problem. Numerical difficulties will be found in the vicinity of a small parameter in front of a higher order term. Here, we present an analytical solutionby means of matched asymptotic expansions. The result shows that, up to and including the first order of approximation, the solution is in agreement with the exact and numerical solutions of the boundary value problem

Estimating Oil Reservoir Permeability and Porosity from Two Interacting Wells

The Ensemble Kalman Filter (EnKF) can be used as a method to estimate reservoir parameters, such as permeability and porosity. These parameters play an important role in characterizing reservoir performance. The EnKF is a sequential estimation method that uses the parameters at t "“ 1 (called prior) to estimate the parameters at t adjusted by observations at t (called posterior). In this paper, the EnKF was used to estimate the reservoir parameters for the case of a linear flow of two interacting production-injection oil wells. The Laplace transform was used to obtain an analytical solution of the diffusivity equation. A state space representation was generated using the analytical solution. A simulation study showed that the proposed method can be used successfully to estimate the reservoir parameters using well-pressure observations

Quantitative Analysis of the Relationship between Three Psychological Parameters Based on Swallowtail Catastrophe Model

A sudden jump in the value of the state variable in a certain dynamical system can be studied through a catastrophe model. This paper presents an application of catastrophe model to solve psychological problems. Since we will have three psychological aspects or parameters, intelligence (I), emotion (E), and adversity (A), a Swallowtail catastrophe model is considered to be an appropriate one. Our methodology consists of three steps: solving the Swallowtail potential function, finding the critical points up to and including threefold degenerates, and fitting the model into our measured data. Using a polynomial curve fitting derived from the potential function of Swallowtail catastrophe model, relations among three parameters combinations are analyzed. Results show that there are catastrophe phenomena for each relation, meaning that a small change in one psychological aspect may cause a dramatic change in another aspect

Conservative Solute Transport from Soil to Runoff Flow in a Steep Slope Area

Solute transport through soil is the major source of nonpoint pollution. Overland flow development in a steep slope area is a complex and nonlinear system that can be influenced by infiltration excess, saturation excess, and subsurface flow. Variations in rainfall intensity, slope, and land cover can also affect the soil moisture dynamics leading to overland flow formation. This study aims to define the dominant mechanism of runoff generation in a steep slope area. A computational model is developed to estimate the quantities of runoff flow and salinity concentration in soil layers at different depths. For this purpose, field research was conducted with several rainfall heights and land cover types in an area of 57 m2 with average slope of 46.7%. Field experiments indicated that the surface and subsurface flows in a soil depth of up to 30 cm were not dominant mechanisms in clay soil with steep slope even under high rainfall intensity. The output of the flow quantitative model showed that overland flow generation in the field plot was dominated by the saturation excess mechanism. The natural grass plot showed the lowest overland flow percentage; by contrast, removed grass and without grass plots showed percentages of 19.49% and 19.18% for rainfall height of 24.9 and 21.8 mm, respectively. Land cover was identified as an important factor affecting runoff generation. The output of the solute transport model for rainfall height of 24.9 mm with salt addition indicated that natural grass and removed grass plots had the lowest salinity concentrations of 55.45 and 33.62 ppm, respectively. Salinity transport was slowest on the natural grass plot, and it started only 45–50 min after artificial rain was applied