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29 June 2010

Model Dinamika Sistem dan Krisis Dunia (Krisis Energi dan Sumber Alam).

Model Dinamika Sistem dan Krisis Dunia


Model Dinamika Sistem dan Krisis Dunia (Krisis Energi dan Sumber Alam).

The Houw Liong

Sekitar tahun 1960 -- 1970 Jay Forrester seorang guru besar di MIT mencetuskan model dinamika system yang dapat dipakai untuk menganalisis aliran barang pada industri dan kelompoknya berhasil memperluasnya untuk menganalisis dinamika system dunia. Kelompok yang dipimpinya mengambil populasi/jumlah penduduk , hasil industri dan pertanian, sumber alam dan lahan subur, polusi dan sampah sebagai kuantitas penting yang perlu diperhatikan.
Jumlah penduduk dunia naik sekitar 2% per tahun, meningkatnya jumlah penduduk secara eksponensial ini yang berarti populasi akan menjadi dua kali lipat setiap 70 tahun. Jumlah penduduk dunia ada sekitar 6 milyar dalam tahun 2000 dan kalau pertumbuhanya tetap 2%, maka dalam tahun 2070 akan menjadi 12 milyar manusia.
Populasi meningkat secara eksponensial berarti kebutuhan pangan, pakaian dan papan/perumahan akan meningkat, ini berarti hasil pertanian dan industri perlu ditingkatkan secara eksponensial pula, akibatnya sumber alam dan luas tanah subur akan menipis, polusi dan sampah akan bertambah, kalau ini berlangsung terus maka dunia akan menuju krisis.
Model ini menunjukkan bahwa tanpa strategi dan tindakan yang tepat sekitar tahun 2050 saja mungkin menusia sudah krisis air bersih, menipisnya sumber alam dan kerusakan lingkungan yang parah.
Memang model ini banyak dikritik dan ditunjukkan terdapat kelemahan, namun kecenderungan umum bahwa tanpa strategi dan tindakan yang tepat untuk menanganinya maka dunia akan menuju krisis.

Faktor lain yang sangat penting ialah pemakaian energi yang terus meningkat sehingga dalam beberapa tahun saja sudah mencapai puncak pemakaian BBM (peak oil) yaitu produksi BBM tidak bisa lagi memenuhi permintaan/pemakaian BBM, dan pengembangan energi alternatif tidak cukup untuk memenuhi kebutuhan energi.

Hal ini menunjukkan bahwa dunia sedang menuju krisis energi.

Negara maju seperti Prancis memutuskan untuk memakai tenaga nuklir, walaupun disadari resiko kecelakaan reaktor nuklir tetap ada. Prancis memakai PLTN untuk memenuhi 78 % kebutuhannya dan juga menjualnya ke negara lain.

Negara berkembang seperti Indonesia masih harus mempersiapkan diri untuk bisa membangun PLTN yang memerlukan biaya puluhan trilyun rupiah dan pengetahuan serta keterampilan dan disiplin untuk mengoperasikan PLTN serta menangani sampah nuklir .

Indonesia juga sudah mendekati puncak pemakaian BBM untuk mengatasi hal tsb, pengembangan energi alternatif perlu dipercepat/digalakkan disertai dengan perubahan pola hidup yang hemat energi dan sumber alam dengan melakukan 3R ( reduce, reuse, recycle).

21 June 2010

Prediction Model of Solar Radiation in Indonesian Regions Using ANFIS

MODEL PREDIKSI RADIASI MATAHARI WILAYAH INDONESIA DENGAN MENGGUNAKAN MODEL ANFIS DAN APLIKASINYA
Master Theses from JBPTITBPP / 2009-12-31 16:16:13
Oleh : YUSUF SURYO UTOMO (NIM 22406001)
Pembimbing I : Prof. Dr. Bayong TJHK
Pembimbing II : Prof. Dr. The Houw Liong

Central Library Institute Technology Bandung
Dibuat : 2009, dengan 7 file

Correlation analysis shows a strong correlation between solar activity and cosmic ray flux and solar constant. A higher correlations (but with opposite sign) are found between solar constant variations and sunspot number variations than between variations in cosmic ray flux and solar constant. It was found a positive correlation between solar constant and sunspot number, with correlation coefficient about 0.89 and 0.96 for monthly and yearly data, respectively. In other hand, a negative correlation between solar constant and cosmic ray flux, i.e. –0.65 and –0.69. It was found a negative correlation also between solar activity and cosmic rays flux, i.e. –0.73 (monthly) and –0.77 (yearly). When solar activities decrease until minima condition, the cloud cover rate increase due to secondary ions produced by cosmic rays. The increasing of the cloud cover rate cause the decreasing of solar constant value and solar radiation on the earth surface.





Monthly solar radiation prediction for 14 locations in Indonesian region using Adaptive Neuro-Fuzzy Inference System (ANFIS) model has been done. Sunshine duration and solar radiation measurement of period 1994-2003 are used as input data. Generally, prediction using ANFIS method give a good result with low Root Mean Square Error (RMSE) relatively. Prediction time-length varies of 3 to 9 months with error prediction less than 10%, depends on characteristic and data length. In addition, prediction result has been validated using ground data and satellite data from NASA SSE website with error validation less than 10%.

In addition, the ANFIS outputs were used for designing a solar water pumping system by using Lost of Energy Probability (LOEP) method for application purpose. Using this method size of the system, i.e. area and number of PV module and battery capacity can be calculated. It was found 4 match locations for this system, i.e. Makassar, Pontianak, Padang and Bengkulu because of their higher direct radiation than diffuse radiation component.

Copyrights : Copyright Â(c) 2001 by ITB Central Library. Verbatim copying and distribution of this entire article is permitted by author in any medium, provided this notice is preserved.

17 June 2010

Weather/Climate Regional Model in Indonesia and Terrestrial Effects of Solar Activity

Weather/Climate Regional Model in Indonesia
and Terrestrial Effects of Solar Activity

Plato M. Siregar 1) Deni Septiadi 2) The Houw Liong 3)

1) Science Atmosphere Division, Faculty of Earth Science and Mineral Technology, ITB
2) Climatology Station of Siantan Pontianak, Meteorologycal and Geophysical Agency, BMG
3) Physics of Complex System Division, Faculty of Mathematics and Natural Sciences, ITB



ABSTRACT

Weather/Climate in Indonesia is influenced by four main quasi periodic cycles: Solar Activity Cycle (Sunspot Numbers Cycle), Galactic Cosmic Ray Cycle, El Nino Southern Oscillation (ENSO) Cycle, and Indian Ocean Dipole Mode (IOD) Cycle. It can be shown that solar activity cycle can be considered as primary cycle that influence other cycles. In practice eastern Indonesian region is dominantly influenced by ENSO. When the heat pools moves to eastern Indonesian region, then rainfall in this region will be above normal. On the other hand when the heat pool leaves eastern Indonesian region and moves to Pacific Ocean then the rainfall in this region will be below normal.
During a typical Indian Ocean Dipole Mode (IOD) event the weakening and reversal of winds in the central equatorial Indian Ocean lead to the development of unusually warm sea surface temperatures in the western Indian Ocean. IOD negative means wet condition or the rainfall will be above normal along the western Indonesian region.
Precipitation in Pontianak region which represent middle Indonesian region correlated strongly with sunspot numbers cycle (solar activity cycle).
Using ANFIS (Adaptive Neuro Fuzzy Inference System) we are able to predict sunspot numbers cycles so that extreme weather in Indonesian regions can be predicted.
Fuzzy c-means is used to classify regions that are influenced strongly by sunspot numbers (solar activity), IOD, and ENSO cycles. This method is based on fuzzy set as fuzzy c-partition of three cycles above and as cluster center. Fuzzy c-partition matrix for grouping a collection of n data set into c classes.
This study explores the physical of climate predictions and classifications of Indonesian regions and its physical interpretations.
This research using monthly rainfall data (mm) collected by 5 raingauges in West Kalimantan (BMKG) with 46 years length of data (1961-2006). Additionally data are monthly sunspot and cosmic rays data (1961-2006) of Royal Observatory of Belgium and Sunspot Index Data Center at http://www.astro.oma.be/SIDC.


Keywords : ANFIS, fuzzy clustering, climate, solar activity

09 June 2010

Variabilitas Harian Equatorial Spread F di Atas Biak

Indonesian Journal of Physics, Vol 12, No 3 (2001)

Variabilitas Harian Equatorial Spread F di Atas Biak (01 derajat LS, 135 derajat BT)
Buldan Muslim, Sarmoko Saroso, The Houw Liong

Abstract

Kejadian equatorial spread F (ESF) di Biak (01 derajat LS, 135 derajat BT) telah diteliti berdasarkan data harian selama Maret dan April tahun 1992 dengan kondisi "sunspot" sedang dalam bentuk laju pertumbuhan ketidakteraturan menggunakan mekanisme ketidakmantapan Gravitational Rayleigh-Taylor (GRT) yang meliputi instabilitas gravitasi dan persilangan antara medan listrik dan medan magnet. Statistik kejadian ESF di Biak telah diuji dalam hubungannya dengan variasi ketinggian maksimum h'F setelah matahari terbenam, kecepatan kenaikan h'F dan fluktuasi dari kenaikan tersebut. Selain itu juga dikaitkan dengan aktivitas matahari dan geomagnet. Didapatkan bahwa variasi harian kejadian ESF di Biak dapat dijelaskan dengan baik secara umum menggunakan dasar mekanisme GRT. Berdasarkan pada data Maret tahun 1992 - 1995 kejadian ESF menurun dengan berkurangnya aktivitas matahari.

Analysis of the chaos dynamics in(Xn,Xn+1)plane

arXiv.org > nlin > arXiv:nlin/0205032



Nonlinear Sciences > Chaotic Dynamics
Analysis of the chaos dynamics in(Xn,Xn+1)plane
S. Soegianto, The Houw Liong
(Submitted on 15 May 2002)
in the last decade, studies of chaotic system are more often used for classical choatic system than for quantum chaotic system, there are many ways of observing the chaotic system such us analyzing the frequency with Fourier transform or analyzing initial condition distance with Liapunov Exponent, this paper explains dynamic chaotic process by observing trajectory of dynamic system in (Xn,Xn+1) Comments: 7 pages, 17 figure
Subjects: Chaotic Dynamics (nlin.CD)
Cite as: arXiv:nlin/0205032v1 [nlin.CD]

Submission history
From: Soegianto Soelistiono [view email]
[v1] Wed, 15 May 2002 08:38:36 GMT (107kb)

02 June 2010

Magnetic Properties of Igneous Rocks from Banyuwangi, East Java

Indonesian Journal of Physics, Vol 16, No 2 (2005)

Magnetic Properties of Igneous Rocks from Banyuwangi, East Java And Their Reliability for Paleomagnetic Study
La Ode Ngkoimani, Satria Bijaksana, Mahrizal , Chalid Idham Abdullah, The Houw Liong

Abstract


We have measured 78 oriented specimens taken form two igneous intrusions in Gunung Nangkajajar at the eastern tip of Java near the town of Banyuwangi for rock magnetic and paleomagnetic investigations. The two intrusions are then referred to as ANBW and DINJ respectively. Upon magnetic measurements, ANBW specimens are found to be magnetically stronger than their DINJ counterparts are. Nevertheless, the specimens in the two sites are suitable for paleomagnetic study as they are magnetically quite isotropic with percent anisotropy well below 10% and magnetic remanence that are stable and consistent upon demagnetization. The consistency of remanence is indicated by the low value of limit or size of cone of confidence, simply referred to as a95 and by the high value of precision parameter k. The results show that paleolatitude of these intrusions was about thirty degree South (30° S), which is far south than their present position. The actual motion of these sites is still being investigated, as no absolute age is known for them. Nevertheless, these paleomagnetic finding is very important as no paleomagnetic data ever existed for the eastern tip of Java.