Hasil Pencarian  ::  Simpan CSV :: Kembali

"Lokasi jembatan pada daerah rawan gempa dan penurunan mutu beton secara signifikan menyebabkan perlunya studi lebih mendetail mengenai perilaku inelastik pier jembatan tersebut. Perilaku inelastik jembatan dapat diidentifikasi melalui analisa nonlinear time history pada sendi plastis yang terjadi pada kolom pier. Untuk mendapatkan perbandingan perilaku sendi plastis, maka pier dimodelkan menjadi dua, yaitu model desain (mutu rencana) dan model eksisting (mutu rendah). Kondisi akhir penampang pasca eksitasi gempa dapat diketahui dengan menggunakan elemen fiber pada program MIDAS CIVIL. Hasil simulasi yang dilakukan menunjukkan bahwa hampir semua penampang model eksisting mengalami crushing beton, sementara penampang model desain hanya mengalami cracking. Selain itu, juga terjadi perubahan tipe kegagalan struktur dari kegagalan daktail pada model desain menjadi kegagalan getas pada model eksisting.

---

Bridge located at seismic zone and the concrete strength deterioration lead to a more detailed investigation of the inelastic behaviour of the bridge. The inelastic behaviour can be identified by nonlinear time history analysis on the plastic hinge, which occur at the column. For results comparation, two models are used for the pier which are deign model (initial design compressive strength) and existing model (low compressive strength). Final condition of the column section after lateral excitation can be obtained by assigning fiber element on MIDAS CIVIL. Simulation results show that concrete crushing occur at the existing model section overall, while on design model section only concrete cracking exist. Furthermore, change of failure mode develops from ductile failure (design model) to brittle failure (existing model)."

"[ABSTRAKLokasi jembatan pada daerah rawan gempa dan penurunan mutu beton secara signifikan menyebabkan perlunya studi lebih mendetail mengenai perilaku inelastik pier jembatan tersebut. Perilaku inelastik jembatan dapat diidentifikasi melalui analisa nonlinear time history pada sendi plastis yang terjadi pada kolom pier. Untuk mendapatkan perbandingan perilaku sendi plastis, maka pier dimodelkan menjadi dua, yaitu model desain (mutu rencana) dan model eksisting (mutu rendah). Kondisi akhir penampang pasca eksitasi gempa dapat diketahui dengan menggunakan elemen fiber pada program MIDAS CIVIL. Hasil simulasi yang dilakukan menunjukkan bahwa hampir semua penampang model eksisting mengalami crushing beton, sementara penampang model desain hanya mengalami cracking. Selain itu, juga terjadi perubahan tipe kegagalan struktur dari kegagalan daktail pada model desain menjadi kegagalan getas pada model eksisting.

---

ABSTRACTBridge located at seismic zone and the concrete strength deterioration lead to a more detailed investigation of the inelastic behaviour of the bridge. The inelastic behaviour can be identified by nonlinear time history analysis on the plastic hinge, which occur at the column. For results comparation, two models are used for the pier which are deign model (initial design compressive strength) and existing model (low compressive strength). Final condition of the column section after lateral excitation can be obtained by assigning fiber element on MIDAS CIVIL. Simulation results show that concrete crushing occur at the existing model section overall, while on design model section only concrete cracking exist. Furthermore, change of failure mode develops from ductile failure (design model) to brittle failure (existing model)., Bridge located at seismic zone and the concrete strength deterioration lead to a more detailed investigation of the inelastic behaviour of the bridge. The inelastic behaviour can be identified by nonlinear time history analysis on the plastic hinge, which occur at the column. For results comparation, two models are used for the pier which are deign model (initial design compressive strength) and existing model (low compressive strength). Final condition of the column section after lateral excitation can be obtained by assigning fiber element on MIDAS CIVIL. Simulation results show that concrete crushing occur at the existing model section overall, while on design model section only concrete cracking exist. Furthermore, change of failure mode develops from ductile failure (design model) to brittle failure (existing model).]"

"Mengingat makin banyaknya barang substitusi dan meningkatnyapersaingan, maka masalah kebijaksanaan distribusi produk semakin pentingsehingga proses pendistribusian perlu dioptimalkan.Pelacakan distribusi produk akan menyangkut fenomena-fenomena yangmuncul dan berinteraksi secara dinamis. Struktur fenomena tersebut antara Iainstok dan jaringan barang, orang dan uang. Struktur fenomena tersebutdimaksudkan sebagai kaidah pengambilan keputusan. Oleh karena itukebijaksanaan tentang polar distribusi produk dengan sistem dinamis perlu dikaji.Pelacakan proses distribusi produk, penulis lakukan pada PT. JEM.Mengingat kompleksnya proses pendistribusian, membuat penulis melakukanpembatasan pada produk tertentu dangan daerah distribusi untuk daerah Jakarta.Pembatasan ini diharapkan tidak mengurangi tujuan dalam kaidah pengambilankeputusan bagi perusahaan.Perancangan model distribusi produk pada PT. JEM mengikuti Iangkah-Iangkah dalam pembangunan model dengan sistem dinamis, dimana meIiputi;pengenalan, konseptualisasi, representasi, evaluasi, validasi dan analisa modelHasil yang diperoleh setelah menjalankan model simulasi yang telahdirancang menggambarkan secara umum proses pendistribusian pada PT. JEMcukup baik. Langkah selanjutnya adalah melakukan pengubahan variabel-variabelpada model dalam berbagai skenario, yang dapat dijadikan sumber informasi bagiperusahaan dalam pengambilan keputusan."

"ABSTRAKTerdapat kasus dimana tiga buah pilar jembatan layang beton bertulang yang telah dibangun, memiliki kuat tekan beton dibawah spesifikasi desain. Dari hasil uji beton inti, kuat tekan beton in-place 40% dibawah kuat tekan beton desain. Analisis nonlinier pushover dilakukan untuk mengevaluasi performa dari struktur terhadap beban lateral akibat gempa. Untuk setiap pilar, analisis dilakukan dengan membandingkan dua model, yaitu model dengan kuat tekan beton desain dan model dengan kuat tekan beton rendah. Nonlinieritas didefinisikan dengan menggunakan lump plastic hinge yang memperhitungkan nonlinieritas dari material. Model kemudian didorong secara lateral dengan beban lateral monotonik yang terus bertambah hingga mekanisme kegagalan tercapai untuk mendapatkan kurva pushover. Hasilnya, model dengan mutu beton rendah memiliki kuat geser struktur yang lebih rendah 14-37%, daktilitas peralihan lebih rendah 11-43%, dan rasio peralihan kapasitas/demand (r) lebih rendah 2-47%, jika dibandingkan dengan model dengan mutu beton desain.

---

ABSTRACTThere is a case where three reinforced concrete flyover piers have concrete strength below the spesification from the design. From concrete core test which has been taken, the in-place concrete strength is below the original design strength for about 40%. Nonlinier pushover analysis is done to evaluate the performance of the structure towards earthquake lateral load. For each pier, analysis is done by comparing two models, which are model with design concrete strength and model with low-strength existing concrete. The nonlinearity is included by using lump plastic hinge in the appropriate position which calculates material nonlinearity of the section. Model is then pushed lateraly with monotonic increasing lateral load until collapse mechanism achieved to get the pushover curve. As the result, model with low-strength existing concrete has a lower structure shear strength for about 14-37%, lower displacement ductility for about 11-43%, and lower capacity/demand displacement ratio (r) for about 2-47% compared to the model with design concrete strength.;"

"Obat ARV adalah obat yang digunakan untuk menghambat perkembangan virus HIV dan memperpanjang harapan hidup ODHA (Orang Dengan HIV/AIDS). Kompleksitas demand obat ARV sangat dipengaruhi oleh pola penularan penyakit HIV/AIDS, tuntutan pengobatan seumur hidup, dampak program jangkauan pelayanan ART dan tingkat kepatuhan pasien. Oleh karena itu diperlukan suatu perancangan model inventory yang menjamin service level di rumah sakit yang tinggi. Tesis ini membahas mengenai cara perancangan model inventory sistem logistik desentralisasi obat ARV berdasarkan model epidemi penyakit HIV/AIDS dengan pendekatan sistem dinamis. Penggunaan sistem dinamis dapat menunjukkan keterkaitan hubungan antara model epidemi penyakit HIV/AIDS dengan model inventory. Hasil perancangan model kemudian diverifikasi dan divalidasi dengan serangkaian pengujian. Struktur prilaku dari model yang dihasilkan menunjukkan prilaku yang sama dengan keadaan yang sebenarnya. Hasil dari analisa kebijakan inventory untuk sistem logistik desentralisasi dengan sistem dinamis menunjukkan bahwa kebijakan buffer inventory di rumah sakit sebesar 2.5 bulan , gudang propinsi 4 bulan dan gudang pusat 15 bulan tetap menghasilkan service level 100% dan inventory cost yang minimal.

---

ARV Drugs are drugs used to hinder the development of HIV virus and prolong life expectancy of People Living with HIV/AIDS (ODHA/Orang Dengan HIV/AIDS). The demand complexity of ARV drugs is largely influenced by infection pattern of HIV/AIDS disease, requirement of lifetime treatment, impact of ART outreach program and patient adherence level. There is a need for an inventory model design that guarantees high service level at hospitals. This thesis explains about inventory model design of ARV drugs decentralization logistics system based on HIV/AIDS epidemic model with dynamic system approach. The use of dynamic approach can show relationship between HIV/AIDS epidemic model and inventory model. The result of model design is then verified and validated with a series of testing. Behavioral structure of the result model shows the same behavior occuring in real situation. The result of inventory policy analysis for decentralization logistics system with dynamic system shows that inventory buffer policy at hospitals for 2,5 months, provincial warehouse for 4 months and central warehouse for 15 months still results in 100% service level and minimum inventory cost."

"ABSTRAKAnalisis riwayat waktu nonlinier akan dilakukan pada jembatan melengkung putar balik dengan radius 45 meter. Jembatan yang sangat tidak beraturan ini akan dievaluasi dengan melakukan analisis riwayat waktu nonlinier pada model jembatan yang divariasikan menjadi 3 tipe sambungan: i sambungan kaku ii sambungan sendi iii sambungan lead rubbber bearing. Sendi plastis dimodelkan pada bagian dasar dan bagian atas dari pilar dengan menggunakan sendi plastis fiber. Hasil analisis menunjukkan bahwa jembatan dengan satu perletakan memberikan tingkat kinerja yang lebih baik dibandingkan jembatan dengan dua perletakan, tetapi jembatan dengan satu perletakan lebih kritis terhadap masalah torsi.

---

ABSTRACT Non linear time history analysis will be presented in irregular U turn curved bridge with radius of 45 meters. This highly horizontally curved bridge is evaluated by performing nonlinear time history analysis on the representative bridge model with 3 types of connection i rigid connection ii hinge connection iii lead rubber bearing connection. Nonlinear hinge was modelled at the base and top of the pier by using fiber hinge. The analysis results indicate that bridges with one connection give better performance level than bridge with two connections, but bridges with only one connection is more critical to the torsion issue."

"Perilaku pasca elastik struktur jembatan akibat beban siklik gempa dapat ditunjukkan dengan melakukan analisa riwayat waktu nonlinear. Desain struktur berbasis kinerja (performance based design) diawali dengan pembentukan sendi plastis pada elemen nonlinear jembatan yang tergambar pada kurva momenrotasinya. Definisi potensi sendi plastis dinyatakan dengan penentuan panjang sendi plastis (lp) dan diskritisasi fiber section pada elemen nonlinear struktur (pilar jembatan). Penelitian ini bertujuan untuk melakukan studi parametrik panjang sendi plastis, bentuk penampang pilar, serta pemodelan pondasi terhadap kinerja struktur yang dihasilkan. Disamping itu juga dilakukan tinjauan sensitifitas spektrum gempa terhadap pembentukan sendi plastis. Penelitian ini diawali dengan melakukan pemodelan struktur jembatan, dimana pilar jembatan didesain ulang agar mengalami pelelehan pada saat gempa berlangsung. Hasil penelitian menunjukkan bahwa panjang sendi plastis yang ditempatkan pada pilar berbanding lurus dengan maksimum rotasi yang dihasilkan. Bentuk penampang pilar bulat terbukti memiliki kinerja yang lebih baik dibandingkan penampang persegi. Selain itu, pemodelan pondasi dalam desain struktur sebaiknya juga dilakukan untuk mendapatkan desain yang lebih konservatif. Dalam studi sensitifitas spektrum gempa, ditunjukkan bahwa respons struktur akan teramplifikasi pada saat frekuensi natural struktur berdekatan dengan muatan frekuensi dominan spektrum gempa.

---

Structural post-elastic behavior due to earthquake cyclic loading can be shown by examining a nonlinear time history analysis. Structural design using the approach of performance based design is started with the forming of plastic hinges on the bridge nonlinear elements that is captured on its moment-rotation curves. The definition of potential plastic hinges is defined by the assignment of plastic hinge length (lp) and the discretization of fiber section on structure?s nonlinear elements (bridge piers).

The purpose of this research is to do a parametric study of plastic hinge length, piers cross section shape, and the foundation modeling to the obtained structural performance level. Besides that, this research will also review the sensitivity of earthquake spectrum to the forming of plastic hinges. This research is started with bridge structural modeling, where the piers will be redesigned so that their yielding limit exceeded when the earthquake happened.

The result of this research shows that the assignment of plastic hinge length is proportional to the obtained maximum rotation. Circular sections have a better performance compared to rectangular sections. Besides that, foundation modeling in structural design should be observed to get a more conservative design. In the sensitivity study of earthquake spectrum, this research shows that structural responses will be amplified when the frequency content of the motion and the natural frequencies of the structure are close to each other."

"This paper is the result of the rain attenuation research, especially the results of ARIMA modeling of tropical rain attenuation in thr design of 28 GHZ millimeter wave communication system. Data acquasition is done on the link distance of 56.4 meters on Electrical campus ITS Surabaya. Data acquisition was recorded using the device every 1 second. The data obtained are processed using an ARIMA (p,d,q) model. The process aims to obtain a time series model. Validation process in done by comparing the ARIMA model result with measurements and attenuation model of ITU - R P.838-3. From 6 events that obtained in February 2009 concluded that all events can be approached by ARIMA (0,1,1) model. ARIMA (0,1,1) model can be used to generate rain attenuation data."

"ABSTRAKWhen a large dimension of rock needed for an armored layer of breakwater, the scarcity of it became a major adversity, because of that many research subject of using concrete as a substitute for rock performed. One of the research are the usage of concrete block for submerged breakwater as a method for avoiding a very large concrete block, but still able to withstood wave forces. The key is in the interlocking of each concrete block so it could achieve the desired result with a lesser dimension concrete block. The research was performed in Laboratory of Coastal Experimental Station, Water Resource Research Center, using a 2D channel. The facility used were flume channel, regular wave generator machine, wave dumper, wave probe, and computer for processing data. The experiment indicate that the wave energy attenuation depends on the dimension of interlocking concrete block type submerged breakwater. The dimension represented in the form of relation of the distance of water level to structures crest and the crests width. The breakwater performance of the concrete block is quite useful as an underwater coastal protection building viewed from reflection with a reflection coefficient of 34.7% at (h?d) / h = 0 and the peak width of B = 2.0"

"A numerical model based on the new theoretical micromechanical and lattice models has been proposed to simulate the fracture behavior of concrete specimens....."