Sardjito Sardjito
Politeknik Negeri Bandung, Jl. Terusan Gegerkalong Hilir, Ds. Ciwaruga, Kotak Pos 1234, Bandung

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ANALISIS GETARAN ROTASIONAL TEREDAM SISTEM BATANG DAN PEGAS TORSIONAL UNTUK DIKEMBANGKAN SEBAGAI MODEL FLUKTUASI EKONOMI Nani Yuningsih; Kunlestiowati Hadiningrum; Sardjito Sardjito
PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) Vol 6 (2017): PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) SNF2017
Publisher : Program Studi Pendidikan Fisika dan Program Studi Fisika Universitas Negeri Jakarta, LPPM Universitas Negeri Jakarta, HFI Jakarta, HFI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (325.513 KB) | DOI: 10.21009/03.SNF2017.02.CIP.04

Abstract

The ideal free vibration system is characterized by periodic oscillation motion with fixed amplitude. In fact, towards this kind of vibration system, there is an external force that will dampen the vibration so the amplitude will be decreased continuously. In damped vibrations, in addition to amplitude change, the frequency will also be different from the frequency of free vibration. It has been observed the phenomenon of rotational homogeneous rods attached to torsional spring and occurs damping due to air friction both theoretically and empirically. Basically rotational vibration characteristics are similar to translational vibrations. The observed variables are the deviation angle of the amplitude and the vibration period. Measurements are done by video camera and digital counter. The empirical observations reinforce the solution of the differential equations obtained by theoretical analysis of the damped vibration system. The result of the research on the mechanical rod and spring vibration system was developed to observe the phenomenon of economic fluctuation occurring in Indonesia, using the analogy between physics phenomenon and economic phenomenon (econophysics). Keywords: rotational vibration, torsional spring, econophysics.
STUDI TEORITIS PERBANDINGAN APLIKASI MODEL GETARAN HARMONIK LOGARITMIK dengan OSILATOR ROTASI PEGAS TORSIONAL UNTUK DIKEMBANGKAN PADA FENOMENA EKONOMI Kunlestiowati Hadiningrum; Nani Yuningsih; Sardjito Sardjito
PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) Vol 6 (2017): PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) SNF2017
Publisher : Program Studi Pendidikan Fisika dan Program Studi Fisika Universitas Negeri Jakarta, LPPM Universitas Negeri Jakarta, HFI Jakarta, HFI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (382.788 KB) | DOI: 10.21009/03.SNF2017.02.CIP.11

Abstract

Abstrak Tinjauan system pegas dengan beban bermassa dapat menghasilkan gerak getaran yang ditandai dengan berubahnya posisi beban terhadap waktu mengikuti fungsi osilasi harmonik. Jika massa beban konstan, maka fungsi posisi terhadap waktu akan berbentuk harmonik murni berupa gelombang sinus dan/atau cosinus. Apabila massa beban berubah secara linier, akan mengakibatkan terjadinya relaksasi perioda getaran, sehingga solusi posisi beban berbentuk fungsi osilasi harmonic logaritmik. Untuk tinjauan skala laboratorium, kondisi ini dapat diterapkan pada Osilasi Rotasional Pendulum Torsi. Model pegas berbeban telah dikembangkan untuk mendeskripsikan peristiwa dinamika nilai tukar rupiah terhadap valuta asing, khususnya bila ada gangguan yang cukup berarti yang berakibat pada terjadinya lonjakan, mengingat dalam situasi ekonomi Indonesia, kadang-kadang muncul gejolak yang menimbulkan lonjakan ekonomi, yang tidak dapat diperkirakan sebelumnya. Model ini bermula dari analogi gejala fisika dengan gejala ekonomi, tetapi model ini masih perlu diperbaiki dengan memasukkan factor gangguan yang bekerja dalam waktu yang sangat singkat bukan hanya pada saat awal agar menghasilkan fungsi delta atau fungsi diskrit sehingga solusinya dapat ditinjau dengan pendekatan diskrit. Kata-kata kunci: getaran, massa berubah, fungsi harmonik logaritmik, pendulum torsi Abstract The overview of the mass-loaded spring system could produce vibration motion characterized by the change of the load position over time following the harmonic oscillation function.If the load mass is constant, then the function of position to time will be a pure harmonic form of sine wave and / or cosine.If the load mass is changed linearly, it will result in the relaxation of the vibration period, so the solution of the load position is in the form of a harmonic logarithmic oscillation function.For a laboratory scale review, this condition can be applied to the rotational oscillation torsion pendulum.The loaded spring model has been developed to describe the dynamics of the exchange rate of the rupiah against foreign exchange, especially when there is significant interference resulting in a spike, given the economic situation in Indonesia, there are sometimes fluctuations that cause unexpected economic hikes.This model begins with the analogy of physical and economic phenomenon. However, this model still needs to be fixed by incorporating the interference factor that works in a very short time not only at the beginning, in order to produce delta function or discrete function so that the solution can be reviewed with discrete approach. Keywords: vibration, mass changing, harmonic logarithmic function, torsion pendulum.
ANALOGI MODEL OSILATOR HARMONIK LOGARITMIK PENDULUM TORSI DENGAN FLUKTUASI NILAI TUKAR RUPIAH TERHADAP US DOLLAR Nani Yuningsih; Kunlestiowati Hadiningrum; Sardjito Sardjito
PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) Vol 7 (2018): PROSIDING SEMINAR NASIONAL FISIKA (E-JOURNAL) SNF2018
Publisher : Program Studi Pendidikan Fisika dan Program Studi Fisika Universitas Negeri Jakarta, LPPM Universitas Negeri Jakarta, HFI Jakarta, HFI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (264.866 KB) | DOI: 10.21009/03.SNF2018.02.PA.07

Abstract

Abstrak Peristiwa fluktuasi nilai tukar rupiah terhadap US Dollar ada keserupaan dengan getaran paksa teredam. Untuk mengetahui adanya kemiripan fluktuasi nilai tukar rupiah terhadap US Dollar beserta faktor-faktor peubahnya dengan getaran paksa teredam, dilakukan uji model getaran paksa teredam menggunakan perangkat pendulum torsi. Untuk getaran paksa teredam sumber tegangan yang digunakan 8-8,4 V dan dengan nilai tukar rupiah terhadap US Dollar pada perioda tahun 2013 sampai 2017. Hasil analisis menunjukkan adanya kemiripan antara simpangan getaran paksa teredam dengan dinamika nilai tukar rupiah terhadap US dollar. Efek redaman pada getaran dianalogikan dengan kebijakan pemerintah untuk menstabilkan nilai tukar rupiah dan gaya paksa dianalogikan sebagai gangguan faktor eksternal. Hasil perhitungan melalui regresi sederhana dan SPSS diketahui koefisien pergerakan nilai tukar dan ampiltudo getaran mempunyai arah yang sama, yaitu arah positif. Dari uji korelasi melalui analisis deskriptif dan analisis inferensial diperoleh hubungan (korelasi) dengan kekuatan Sedang antara nilai tukar rupiah dengan simpangan getaran paksa teredam, dengan koefisien korelasi sebesar 0.595. Hal ini menunjukkan bahwa apabila nilai tukar naik (rupiah melemah), maka simpangan akan meningkat secara signifikan, sebaliknya jika nilai tukar menurun (rupiah menguat) maka simpangan akan menurun secara signifikan. Kata-kata kunci: pendulum torsi, getaran paksa teredam, nilai tukar rupiah, uji korelasi. Abstract There are similarities between the Rupiah rate exchange against the US Dollar and forced damped vibration. To identify those similarities along with the variables of its effect with forced damped vibration, a forced damped vibration model is tested using a pendulum torque device. For forced damped vibration the voltage source used is 8-8.4 V and with the Rupiah exchange rate against the US Dollar from 2013 to 2017. The results of the analysis show that there are similarities between forced damped vibration and the dynamics of the Rupiah exchange rate against the US Dollar. The effect of attenuation on vibration is analogous to the government policy to stabilize the Rupiah exchange rate, and the forced force is analogous to the external factor disruption. The results of calculations through a simple regression and SPSS note that the exchange rate movement coefficient and vibration amplitude have the same direction, namely the positive direction. From the correlation test through descriptive analysis and inferential analysis obtained the relationship (correlation) with the medium strength between the Rupiah exchange rate with the forced damped vibration deviation, with a correlation coefficient of 0.595. This shows that if the exchange rate rises (the Rupiah weakens), then the deviation will increase significantly, on the contrary, if the exchange rate decreases (the Rupiah strengthens) then the deviation will decrease significantly. Keywords: pendulum torque, forced damped vibration, Rupiah exchange rate, correlation test