Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004 DAFTAR ISI
HAL
MODIFIKASI ALAT UKUR DIELEKTRIK METODA Q-METER DAN NILAI SIFAT DIELEKTRIK LADA Modification of Q-Meter Type Dietectric Meter and the Dielectric Properties of Pepper Harmen, Armansyah H. Tambunan dan Setyawan Widyarto
153~162
MODEL SIMULASI PENGENDALIAN SUHU UDARA PADA MESIN PENGERING CABE DENGAN KONTROL LOGIKA FUZZY Bambang Dwi Argo dan Cicik Rahayu
163~177
PEMODELAN FAKTOR ERGONOMI TERHADAP PRODUKTIVITAS KERJA PADA PENGOLAHAN TANAH PERTAMA AREAL PADI SAWAH Modeling of ergonomic factors on working productivity in primary tillage of paddy field Arief RM Akbar, Bambang Pramudya, Sam Herodian dan I Wayan Astika
178~190
PEMODELAN SISTEM FILTRASI TERKENDALI PADA RESIRKULASI PEMBENIHAN IKAN Modelling Controlled Filtration System in Fish Hatchery Recirculating System Ardiansyah, Budi Indra Setiawan dan I Dewa Made Subrata
SISTEM
191~198
PROSES HIRARKI ANALITIK UNTUK MENENTUKAN METODE PENGOLAHAN TANAH OPTIMUM Analytical Hierarchy Process for Determining Optimum Soil Tillage Method Gatot Pramuhadi, E. Namaken Sembiring, Radite Praeko Agus Setiawan, dan M. Achmad Chozin
199~209
EVALUASI TINGKAT KETUAAN DAN KEMATANGAN JERUK NIPIS (Citrus Aurantifolia Swingle) DENGAN PENGOLAHAN CITRA DIGITAL DAN JARINGAN SYARAF TIRUAN The Evaluation of Maturity and Ripeness of The Limonia Aurantifolia (Citrus aurantifolia Swingle) Using Image Processing and Artificial Neural Network Zainul Arham, Usman Ahmad dan Suroso
210~218
KESESUAIAN HUJAN TAHUNAN UNTUK HUTAN PINUS BERDASARKAN PEMODELAN NERACA AIR Annual Rainfall Suitability For Pine Forest Based On Water Balance Modeling Darmadi, Sri Astuti Soedjoko dan Suyono
219~229
Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004 MODIFIKASI ALAT UKUR DIELEKTRIK METODA Q-METER DAN NILAI SIFAT DIELEKTRIK LADA Modification of Q-Meter Type Dietectric Meter and the Dielectric Properties of Pepper Harmen1, Armansyah H. Tambunan2 dan Setyawan Widyarto
Abstract Q-meter is an indirect methods dielectric properties measurement by measuring voltage (Q) and capacitance (C) which is naturally in the form of alternating current (AC). Modification of the Q-meter, by directing the AC into DC current is considered to have advantage, such as easiness to measure and stability of the measured properties. This paper is devoted to the discussion on the performance of the modified apparatus and characteristics of the measured value on pepper. The results show that the modified dielectric properties meter can be applied satisfactorily in the frequency range of 6-26 MHz. There was still instability of measurement at frequency 6 MHz and 10 MHz, but significantly more stable than measurement with the unmodified apparatus. The apparatus shows a significant difference in the dielectric constant due to the difference in moisture content of the sample. However, the same difference in the dielectric loss factor is not occur along the frequency range.
1 2
Staf Pengajar Politeknik Negeri Bandar Lampung Staf Pengajar Departemen Teknik Pertanian, Institut Pertanian Bogor
153~162
Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004 MODEL SIMULASI PENGENDALIAN SUHU UDARA PADA MESIN PENGERING CABE DENGAN KONTROL LOGIKA FUZZY Bambang Dwi Argo1 dan Cicik Rahayu
Abstrak Pada penelitian ini dilakukan simulasi pengendalian suhu udara pada alat pengering cabe dengan menggunakan Kontrol Logika Fuzzy. KLF diharapkan dapat mengendalikan suhu ruang pengering dengan cara mengatur besarnya energi yang harus diberikan kepada pemanas. Kriteria pengendalian adalah tidak terjadinya lewatan (overshoot), setting time dan RMSE yang minimum. Karakteristik suhu pada masing-masing sub sistem pengering didekati dengan persamaan/model matematika berdasarkan keseimbangan energi pindah panas dan massa. Hasil dari persamaan yang ada diselesaikan secara numerik dengan Metode Finite Different Euler lmplisit yang diselesaikan secara simultan dengan metode Gauss Jordan. Untuk mengendalikan suhu udara pengering dilakukan dengan mengatur besarnya daya yang harus diberikan ke heater (pemanas) berdasarkan error dan perubahan error. Error dan perubahan error ini merupakan masukan bagi Kontrol Logika Fuzzy. Keluaran dari KLF adalah daya yang diberikan kepada pemanas. Fungsi keanggotaan masukan adalah fuzzy singleton. Untuk jumlah himpunan fuzzy masukan dibagi menjadi tiga yaitu 3,5 dan 7 himpunan. Fungsi keanggotaan dipakai untuk fuzzikasi dan defuzzikasi. Program simulasi computer dikembangkan dengan menggunakan bahasa pemrograman Borland Delphi 5.0 dibawah sistem operasi Windows 98 dengan prosesor Celeron 566 MHz dan RAM 25b MB. Model keseimbangan energi pindah panas dan massa yang dibuat telah mampu menerangkan perubahan suhu pada masing-masing sub sistem pengering. Nilai determinasi (R2) untuk sub sistem suhu ruang pengering, produk dan ruang heater berturut-turut adalah 0.65, 0.62 dan 0.67. nilai RMSE berturut-turut adalah 2.2, 2.8 dan 2.3. Laju aliran udara diperoleh dari simulasi tanpa kontrol dengan daya heater yang tetap dan laju aliran yang berubah-ubah yaitu sebesar 0.25 kg/detik. Sedangkan dari simulasi dengan laju aliran udara yang tetap dan daya heater yang berubah-ubah menunjukkan bahwa dengan daya heater yang dapat menaikkan suhu ruang pengering 45 - 55°C adalah sebesar 15000 W. Kontrol Logika Fuzzy dengan 7 himpunan fuzzy masukan mempunyai hasil yang terbaik dibandingkan dengan 3 dan 5 himpunan fuzzy. Unjuk kerja KLF dalam mengendalikan sistem dengan setpoint yang berbeda yaitu 45-55°C menghasilkan performansi sistem yang baik yaitu tidak terjadi overshoot dan suhu udara pengering yang dihasillcan mempunyai fluktuasi yang kecil. Karakteristik pengeringan dengan KLF dengan suhu setpoint 45-50°C menunjukkan hasil simulasi pengeringan pada suhu 45°C selama 72 jam pengeringan mampu menurunkan kadar air cabe dari 80% menjadi 32.94% KABB atau 400% menjadi 49.12% KABK dengan kebutuhan energi sebesar 437.750 kWh. Sedangkan pada suhu setpoint 50°C selama 72 jam pengeringan mampu menurunkan 80% menjadi 22.88% KABB atau 400% menjadi 29.67% dengan kebutuhan energi sebesar 547.02 kWh. Kata kunci : Simulasi, Mesin Pengering, Logika Fuzzy
1
Staf Pengajar Jurusan Teknik Pertanian Fakultas Teknologi Pertanian Universitas Brawijaya
163~177
Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004 PEMODELAN FAKTOR ERGONOMI TERHADAP PRODUKTIVITAS KERJA PADA PENGOLAHAN TANAH PERTAMA AREAL PADI SAWAH Modeling of ergonomic factors on working productivity in primary tillage of paddy field Arief RM Akbar1, Bambang Pramudya2, Sam Herodian2 dan I Wayan Astika2
Abstract The measurement working productivity of hand tractor in soil tillage of paddy field was not performed precisely. Two models have ben developed to study the relationship between ergonomic factors and working productivity in primary tillage.The first model (A) was applied to soil tillage by hand tractor with gelebeg implement and the second model (B) was applied to soil tillage by hand tractor with rotary implement. Ergonomic factors analized in the model were optimal height of hand tractor steer. Artificial neural network was used to formulate the non linear relationship among the analyzed parameters. The models, which are A and B, have accuracy of calibration 97% and 93% respectively, as well as accuracy of validation 89% and 87%. The outputs models are productivity and workload. The models were also used to determine the optimum height of hand tractor steer in order to minimize work load. Results showed that the optimum height of steer for model A in a range of 110 cm and 113 cm and the optimum height of steer for model B in a range of 87 cm and 96 cm. Keywords : Ergonomic factor, productivity, heart rate, artificial neural network
1 2
Mahasiswa Program Doktor Pada PS TEP, Sekolah Pascasarjana IPB Staf Pengajar Departemen Teknik Pertanian, Fateta IPB
178~190
Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004 PEMODELAN SISTEM FILTRASI TERKENDALI PADA SISTEM RESIRKULASI PEMBENIHAN IKAN Modelling Controlled Filtration System in Fish Hatchery Recirculating System Ardiansyah1, Budi Indra Setiawan2 dan I Dewa Made Subrata2
Abstract Re-circulating Aquaculture Systems are systems which re-use water equipped with mechanical and biological treatments. A re-circulating system generally occupies very little area, requires less water and provides a predictable production. Recirculation system developed in this research consists of four sub system. They are; supply unit, hatchery unit, sedimentation unit and filtration unit. One component which plays significant role in recirculating system is filtration unit for mechanical and biological treatments. This unit eliminates solute from fish waste and uneaten food by holding it in the pores of mechanical filter. Moreover, the biological filter transforms ammonia (NH3) which is toxic to fish to relatively harmless nitrate (NO3 -) through bacterial nitrification. The aim of this paper is to describe the pattern of water flow in multi-layer, horizontal filtration unit. Four layers with distinct materials which each has their own hydraulic conductivity prepared to perform filtration function. Fuzzy logic controlling is applied to keep balance of water flow in the whole re-circulating system. Finally, evaluation on decreasing hydraulic conductivity was performed to determine filter affectivity during fish culture. Keywords : Re-circulating system, filtration, hydraulic conductivity, fuzzy control
1 2
Mahasiswa Program Pascasarjana Ilmu Keteknikan Pertanian IPB Staf Pengajar Departemen Teknik Pertanian IPB
191~198
Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004 PROSES HIRARKI ANALITIK UNTUK MENENTUKA METODE PENGOLAHAN TANAH OPTIMUM Analytical Hierarchy Process for Determining Optimum Soil Tillage Method Gatot Pramuhadi1, E. Namaken Sembiring1, Radite Praeko Agus Setiawan1 dan M. Achmad Chozin2
Abstract Optimum soil tillage on dry land sugar cane cultivation is needed to obtain high sugar cane growth and production, and low production cost. It is obtained by applying the combination of soil tillage patterns and its intensities. The objective of the research was to apply an analytical hierarchy process for determining optimum soil tillage method on dry land sugar cane cultivation. Six soil tillage methods were applied, the efficiency was measured, and the effectiveness of the soil tillage methods for plant growth was monitored periodically until the harvesting time. The results showed that the best soil physicalmechanical conditions provided by the soil tillage method would result in maximum sugar cane growth and production. By using an analytical hierarchy process can be concluded that the soil tillage method of “subsoiling – disk plowing – disk harrowing – furrowing” was the most optimum combination, because it produced high field efficiency, lowest fuel consumption, and most effective method that results in maximum sugar cane growth and production. Keywords : Soil tillage, efficiency, effectiveness, optimum, and production
1 2
Staf Pengajar Departemen Teknik Pertanian, Fakultas Teknologi Pertanian IPB Staf Pengajar Departemen Budidaya Pertanian, Fakultas Pertanian IPB
199~209
Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004 EVALUASI TINGKAT KETUAAN DAN KEMATANGAN JERUK NIPIS (Citrus Aurantifolia Swingle) DENGAN PENGOLAHAN CITRA DIGITAL DAN JARINGAN SYARAF TIRUAN The Evaluation of Maturity and Ripeness of The Limonia Aurantifolia (Citrus aurantifolia Swingle) Using Image Processing and Artificial Neural Network Zainul Arham1, Usman Ahmad2 dan Suroso2
Abstract The object of this study is to evaluate the maturity and ripeness of limonia aurantifolia (Citrus aurantifolia Swingle) using image processing and artificial neural network. Image processing algorithm was developed and applied to 200 samples of limonia aurantifolia from 4 levels of maturity and ripeness; early ripe, mature, ripe and over ripe. The area, color indexes and texture were extracted from sample images using the developed image processing algorithm_ The features extracted from image processing were used as input to develop artificial neural network that modeled into 6 and 8 inputs on 6, 9, 13 and 15 hidden layers with the level of maturity and ripeness as output. The training of artificial neural network used value of 0.8 for momentum constant and learning rate constant, 1.0 for sigmoid function in 3000 iteration. The results showed that the use of 6 and 8 inputs from image processing features provided the highest accurateness were 93.56% and 96.35%, respectively in classifying the limonia aurantifolia based on its maturity and ripeness. Keywords: image processing, artificial neural network, limonia aurantifolia and maturity and ripeness.
1 2
Mahasiswa Program Pascasarjana S3 IPB Staf Pengajar Departemen Teknik Pertanian FATETA IPB
210~218
Jurnal KETEKNIKAN PERTANIAN, Vol.18, No.3, Desember 2004
KESESUAIAN HUJAN TAHUNAN UNTUK HUTAN PINUS BERDASARKAN PEMODELAN NERACA AIR Annual Rainfall Suitability For Pine Forest Based On Water Balance Modeling Darmadi1, Sri Astuti Soedjoko2 dan Suyono3
Abstract Modeling of water balance to predict daily soil moisture on the pine (Pinus mercusii) tree forest. The difference of daily soil moisture could be directly used to calculate the value of actual evapotranspiration (ETactual) of pine tree. The correlation between annual rainfall depth and annual ETactual value is determined suitability of pine forest area. Result of the 5 years (1993 – 1997) research in KPH Banyumas Timur, Central Java province showed that the trees have been grown and well developed with the annual rainfall of 1919 mm/yr and ETactual value of 1156 mm/yr. Its means that the total annual water availability from rain is sufficient to supply total amount water requirement of pine trees grow in the forest. Considering this research it could be summarized that the pine three forest is suitable on the region has total annual rainfall of 1919 mm/yr. However, increasing the value of total annual rainfall 2000 mm/yr is more suitable.
Staf Pengajar Fakultas Teknologi Pertanian Universitas Gadjah Mada Staf Pengajar Fakultas Kehutanan Universitas Gadjah Mada 3 Staf Pengajar Fakultas Geografi Universitas Gadjah Mada 1
2
219~229
