Buckling and Post-Buckling Analysis of Cracked Plates by The Boundary Element Method

PhDThis thesis presents boundary element formulations for buckling and nonlinear buckling analysis of plates. Dual boundary element formulations are also presented for linear and nonlinear buckling, and large deformation analysis of crack behaviour in plates. Reissner plate theory is adopted to represent shear deformable plate bending, and two dimensional plane stress is used to model the membrane behaviour of plate. By taking into account the nonlinear interaction between forces and rotations in the equilibrium equation, the nonlinear formulation is formed by coupling equations of shear deformable plate bending and two dimensional elasticity. The boundary element formulation for plate buckling is developed. Plate buckling equations are written as a standard eigenvalue problem. Buckling coefficients and buckling modes are obtained using this formulation. Initially, the boundary is discretised into quadratic isoparametric elements, and the domain is discretised using constants cells. Next, the dual reciprocity method is utilized to transform the domain integral into equivalent boundary integrals. Examples are presented for plate buckling problems with different geometry, loading and boundary conditions. The results obtained are shown to be in good agreement with analytical and finite element results. The Dual Boundary Element Method (DBEM) for buckling analysis of plate is also developed. The plate buckling equations are also presented as a standard eigenvalue problem, which would allow direct evaluation of critical load factor and buckling modes for cracked plates. Geometrically nonlinear boundary element formulation is developed to analyse large deformation and nonlinear buckling of plates. Different load incremental approaches and solution procedures are presented. Nonlinear terms are evaluated using a radial basis function. Large deformation analysis for Fracture Mechanics problems is also presented. Five stress intensity factors are calculated, i. e. three for plate bending and two for membrane. Crack Opening Displacement (COD) is used to compute the stress intensity factors. The nonlinear buckling of thin plate is also presented. Two models of imperfection are introduced in the formulation, i. e. a small uniform transverse loads and distributed transverse loads based on eigenvectors. A simple numerical algorithm is presented to analyse the problems. Finally, nonlinear buckling analysis of cracked plate is presented. Numerical examples of nonlinear buckling and large deformation problems are presented. The BEM results presented are shown to be in good agreements with analytical and other numerical results

Skip-Gram Negative Sample for Word Embedding in Indonesian-Translation Text Classification

Hadith is the second most fundamental source of Islamic Law after the Holy Qur’an. The Hadith needs to be categorized to ease people’s understanding of the purpose of the Hadith. Indonesian-translated Sahih Al-Bukhari Hadith text was used in this study. This text is unique because it provides Hadith in two languages (Indonesian and Arabic), which exist in a single document. That problem needs specifically text processing to know the meaning of every bag of words. Text classification was used to categorize the Hadith text. The text classification in this research was conducted in two main phases: first, data preprocessing involving word embedding with Skip-Gram Negative-Sample (SGNS) algorithm was done followed by classification using the comparison of Backpropagation (BP) and Support Vector Machine (SVM). Based on the results obtained, the system was able to perform text classification well with BP, returning the highest F1-Score at 82.05%, while SVM only got the highest performance at 76.06%

IMPLEMENTASI MUTUAL INFORMATION DAN BAYESIAN NETWORK UNTUK KLASIFIKASI DATA MICROARRAY

Kanker merupakan salah satu penyebab utama kematian seseorang diseluruh dunia. Menurut data WHO, ada sekitar 14 juta kasus kanker baru di tahun 2012. Karena hal itu pengawasan sejak dini dibutuhkan guna mencegah pertumbuhan kanker. Selain itu pendeteksian secara dini juga merupakan hal yang dibutuhkan. Salah satu cara mendeteksi yaitu melalui ekspresi gen. Ekspresi gen merupakan metode ekstrasi gen menjadi data yang menjadi data bernama microarray. Data microarray memungkinkan terjadi proses pengklasifikasi secara langsung namun atribut dalam suatu record sangat besar sehingga memakan waktu komputasi yang lama. Karenanya dibutuhkan sistem yang dapat menyelesaikan masalah tersebut. Pada penelitian ini, sistem menggunakan pendekatan machine learning yaitu Bayesian Network. Sedangkan untuk seleksi fitur menggunakan Mutual information. Hal ini berguna untuk mengurangi attribute yang terlalu banyak. Untuk pengukuran menggunakan F1-score. Sistem yang dibangun mampu mengklasifikasi kanker dengan f1-score tertinggi mencapai 91.06%

Perbandingan Gini Index dan Chi Square pada Sentimen Analsis Ulasan Film menggunakan Support Vector Machine Classifier

Pada era informasi ini semakin banyak penilaian, pendapat dan pandangan yang dapat ditemukan secara luas di dunia maya. Contohnya adalah ulasan film, di mana penonton berbagi pandangannya mengenai sebuah film. Ulasan film adalah platform di mana para penggemar film dapat mengungkapkan pendapat mereka, baik itu dalam bentuk komentar negatif atau pun positif. Sebagian besar website untuk ulasan film sudah memiliki rating atau bintang, namun rating tinggi tidak selalu diiringi oleh ulasan yang baik begitu pun sebaliknya. Untuk itu, dibutuhkan metode untuk menganalisis teks dengan tujuan mengklasifikasikan apakah ulasan film tersebut termasuk dalam kategori negatif ataupun positif. Teknik yang digunakan adalah analisis sentimen atau opinion mining. Analisis sentimen adalah bidang dalam machine learning yang bertujuan untuk mengambil informasi bersifat subjektif dari teks ulasan. Salah satu metode klasifikasi machine learning adalah Support Vector Machine (SVM). Namun semakin banyak data akan muncul beberapa masalah yaitu banyaknya kata atau fitur yang tidak relevan menyebabkan kinerja pengklasifikasian menurun. Fitur tidak relevan akan menyebab perfomansi yang rendah. Seleksi fitur Gini Indeks dan Chi-Square dibandingkan untuk mengatasi masalah kata yang tidak relevan. Pada penelitian ini, metode klasifikasi SVM kombinasikan dengan metode seleksi fitur untuk meningkatkan performansi. Kombinasi SVM dan Gini Index menghasilkan performansi F1-score sebesar 85.8%. Sedangkan menggunakan SVM dan Chi-Square menghasilkan performansi F1-score tertinggi yaitu sebesar 89.2%

Perencanaan dan Pembuatan Modul Inverter 3 Phase Sebagai Suplai Motor Induksi Pada Pengembangan Modul Praktikum Pengemudi Listrik (Sub Judul Software)

Pada Proyek akhir ini dibuat sebuah modul praktikum pengemudian listrik yang bertujuan untuk mempermudah proses pembelajaran serta menutupi kekurangan modul praktikum yang telah ada. Maka dirancanglah sebuah rangkaian inverter 3fasa sebagai suplai motor induksi 3fasa.Modul ini menggunakan Mikrokontroller ATMega 8535 dengan menggunakan bahasa C untuk menghasilkan PWM(Pulse Width Modulation) . Pembangkitan sinyal PWM digunakan untuk menyulut mosfet pada buck converter dengan frekwensi 40KHz duty cycle yang dapat diatur antara 50% - 70% dan juga untuk menyulut mosfet pada rangkaian inverter 3fasa dengan mode konduksi 180° dan frekuensi penyulutan yang konstan yaitu 50Hz.Dari pengujian didapatkan % error sebesar 26,47% untuk duty cycle 50% dan 11,11% untuk duty cyle 70%. Kata kunci: Inverter 3Fasa,PWM,Mikrokontroller ATMega 8535

FASE-1: IMPLEMENTASI STANDAR ATURAN PEMODELAN UML SEBAGAI DASAR SPESIFIKASI KEBUTUHAN DI EFARMING CORPORA BANDUNG

In Phase 1 of this Abdimas, activities focused on the general analysis presented through system modeling rules and data modeling. This activity will have an impact on the next Abdimas phases. There is a problem focus on how to describe the system and the process of sending data. There was a problem in analyzing the requirements specifications in the process of sending agricultural activist data to its members. In general, the objectives regarding the potential/opportunities for empowerment of farmer members in the EFarming Corpora community can be increased by identifying requirements specifications, which will be defined through the creation of system modeling and data modeling. There is an adoption of the method through modification is carried out for Phase 1 of the Regular Scheme of community service activities, which will provide understanding to farmer activists in the Bandung Corpora Efarming Environment regarding information technology to support Farmer Community activities. The discussion of material implemented in this community service partner includes several supporting results in the next phase. This discussion is the basis for development that can be explored in the System Development Life Cycle stage, through the support of the Software Requirement Specification, Elicitation, Requirement Statement, Software Modeling, and Software Prototype. In its implementation, for Phase 1, Abdimas has a form of activity resulting from several activities: scientific training, a compilation of required information systems, and surveys and analysis of industrial needs

Peningkatan Produktivitas Pengusaha Kerupuk Mlarat melalui Perancangan Mesin Pengulen dan Pemotong Adonan

Kerupuk Mlarat is one of the traditional snacks of Cirebon, a regency in West Java province, Indonesia. This snack is mostly produced by the small medium enterprises (SMEs) through conventional, old-style procedures. That is why, although this snack has abundant potentials, the improvement is still minimum. Most SMEs employ human-powered tools, especially in the process of dough kneading and shaping. Besides the not yet optimum process, the food hygiene of also becomes an issue. In order to optimize the production and maintain product hygiene, a human empowerment program is conducted to provide on of the SMEs with the Kerupuk Mlarat dough kneading and shaping machine. The machine capacity is 20 kilograms and was proven effective to knead, shape, and cut the dough within an hour, a lot less duration compared to the conventional procedures. This machine is expected to efficiently improve the Kerupuk Mlarat SMEs productivity as well as hygiene

Fracture analysis of a corner crack in a pinhole of a solid cylinder under torsion loading

Fatigue crack growths of a corner crack emanating from a pinhole of a solid cylinder subjected to cyclic torsion loading were simulated using a Dual-Boundary Element Method (DBEM) based software. For a given crack aspect ratio a/c, larger Mode I stress intensity factor (SIF) was observed at a larger pinhole diameter. Any given initial crack aspect ratio a/c would evolve towards unity. The final evolving crack aspect ratio a/c was shown to be larger than 1. For the same given initial crack length a, a smaller crack depth c was found to result in a shorter fatigue life. A shorter fatigue life yielded a larger orientation angle of the crack growth path

"Deaf Conference" Aplikasi Alat Bantu Komunikasi untuk Tunarungu dalam Diskusi

Deaf Conference adalah aplikasi mobile yang berfungsi sebagai alat bantu komunikasi untuk para penyandang tunarungu dalam berdiskusi bersama dengan orang normal lainnya. Cara kerja dari aplikasi ini adalah menerima inputan berupa suara kemudian mengubahnya ke dalam bentuk tulisan sehingga pada saat para penyandang tunarungu melakukan diskusi bersama, mereka tidak harus didampingi oleh seorang penerjemah atau pun menggunakan hearing aid untuk menerjemahkan seluruh percakapan setiap peserta. Jika diskusi telah selesai dilaksanakan, aplikasi Deaf Conference dapat merekap semua hasil diskusi tersebut kemudian tersimpan. Deaf Conference memiliki interface yang user friendly karena menggunakan menu-menu serta ikon-ikon yang sudah banyak digunakan pada umumnya. Deaf Conference dapat langsung diinstalasi pada smartphone yang dimiliki oleh pengguna. Pengaturan bahasa yang digunakan pada smartphone akan langsung terintegrasi dengan Deaf Conference. Smartphone yang terhubung dengan jaringan internet atau memiliki paket data dapat mengakses Deaf Conference kapan pun dan dimana pun