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"Dengan mempelajari kelengkungannya, saya membuktikan ekivalensi antara nilai konstan kelengkungan skalar Ricci dan konsep Kahler-Einstein dari gradien Kahler-Ricci soliton pada bidang kompleks Cn dengan model simetri rotasi.

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By studying its curvatures, I prove the nontrivial equivalency between the constancy of Ricci scalar curvature and the Kahler-Einsteinian notion of gradient Kahler-Ricci solitons on the complex plane Cn in rotationally symmetric ansatz."

"This paper presents an overview of the characteristics of the intensity-curvature term with applications in image processing and also in Magnetic Resonance Imaging (MRI) of the human brain. The intensity-curvature term is the key concept that merges together the value of the signal with the value of the classic-curvature, which is the sum of the second order partial derivatives of the model function fitted to the signal. The model function fitted to the signal needs to have the property of second order differentiability, and also to have at least one non null second order partial derivative calculated at the origin of the coordinate system of the pixel. The mathematical meaning of the intensity-curvature term is the mapping of the signal into a novel domain where each value of the signal is multiplied by the arctangent of the angle subtended with the horizontal, by the tangent to the first order derivative of the model function. The mapping merges the value of the signal intensity and the classic-curvature of the signal. Hence, the resulting intensity-curvature term embeds information about both signal intensity and concavity-convexity of the model function. In addition to the classic-curvature, and consequential to the mapping, the intensity-curvature term allows the calculation of three supplementary intensity-curvature measurement approaches (ICMAs): (i) the intensity-curvature functional, (ii) the signal resilient to interpolation, and (iii) the resilient curvature. This paper reviews the implications of the intensity-curvature term with specific focus on the meaning and the nature of the ICMAs, which provide additional imaging of the human brain MRI."

"Kerjasama penelitian UI-Wika Beton dalam pengujian pada struktur spun pile yang tersambung ke pile cap dan dibebani secara siklik sampai mencapai keruntuhan guna mempelajari perilaku sambungan. Meskipun telah mencapai keruntuhan dan secara fisik struktur sudah masuk ke tahap damage atau non repairable, namun studi lanjutan dilakukan untuk mempelajari perilaku dari ketiga benda uji dengan memberikan perbaikan cepat berupa SikaPlate/SikaRod dan FRP Wrap. Studi lanjutan dengan pemodelan OpenSees dilakukan untuk mensimulasikan benda uji repair tersebut untuk menkaji lebih dalam stress dan strain development yang terjadi pada penampang spun pile.  Pemodelan dilakukan dalam 2 dimensi menggunakan software OpenSees. Non-linier fiber element digunakan untuk mensimulasikan penampang spun pile yang mengalami repair. Ditemukan bahwa OpenSees mampu memodelkan benda uji eksperimen dengan sangat baik pada fase linear sampai kondisi maksimum, namun kurang mampu menggambarkan fase damage pasca maksimum. Dari beberapa sensitivity analysis yang dilakukan, pemodelan yang paling mendekati benda uji yang mengalami rusak dan di-repair dengan memodelkan cross section tanpa memodelkan tulangan PC wire yang putus, menggunakan material steel01, memodelkan sambungan dengan bond slip, reduksi mutu beton sejauh  50% sebagai representasi berkurangnya kepadatan beton, serta reduksi tulangan infill  20% sebagai representasi regangan sisa. Hasil analisa menunjukkan bahwa repair terhadap sambungan spun pile mengakibatkan terjadinya tambahan plastic hinge yang semula berada pada daerah sambungan dengan pile cap ke bagian atas dengan tambahan plastic hinge baru di daerah berbatasan perkuatan. Hal yang menarik lainnnya yang ditemukan dari studi pemodelan OpenSees ini adalah nilai curvature yang terjadi pada spunpile dengan tulangan dan beton pengisi mampu mencapai curvature demand yang dibutuhkan pile untuk bertahan terhadap beban gempa.

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A collaboration of research between UI-Wika Beton did a spun pile structure testing, where a spun pile that was attached to a pile cap was given cyclical load until it reached failure, in order to understand the behavior of connections. Although had reached failure, and physically entered the damage or non-repairable stage, further studies were conducted to study the behavior from 3 test specimens by giving rapid repair in the form of SikaPlate/SikaRod and FRP Wrap. A further study with OpenSees modeling is conducted to simulate the repair test specimen to have a deeper insight regarding the stress and strain development on spun pile cross sections. The modeling is done in 2 dimensions using OpenSees software. Non-linear fiber element was used to simulate spun pile cross section enduring the repair. It was discovered that OpenSees were able to excellently model experimental test specimens on a linear phase up until maximum condition, but are not able to illustrate the post-maximum damage phase. From several sensitivity analysis done, the closest modeling is obtained by modeling the cross section without modeling the snapped PC reinforcement, using steel01 material, modeling connections with bond slip, concrete quality reduction to 50% as void representation, and infill reinforcement reduction by 20% as residual strain representation. The analysis shows that a repair to a spun pile connection causes an increase of plastic hinge that was before located on a connection area from pile cap to the upper area, but now is included with the additional new plastic hinges in the area adjacent to the reinforcement. Another interesting thing discovered in the OpenSees modeling is that the curvature value for the spun pile is within the curvature demand range needed to survive seismic load."

"Tugas akhir ini menyajikan tentang bagaimana mengatahui pengoptimalan pipa spiral tiga lobes yang dialiri oleh lumpur dengan tingkat kelengkungan pipa, dengan penggunaan Reynolds Number. Aliran lumpur terdiri dari partikel padat dan fluida yang membentuk endapan, dengan karakteristik aliran yang mempengaruhi pada ukuran partikel, distribusi partikel, konsentrat partikel, geometri pipa, dan viskositas. Konsentrasi lumpur yang mengalir dalam percobaan ini diikuti oleh Concentration Weight. Pusaran yang mengalir dalam pipa spiral akan menunjukkan keefektifan putaran, serta intensitas pusaran sebagaimana dengan persamaannya, dan tekanan jatuhnya. Analisis dan grafik akan dijelaskan dari data dua buah pipa spiral. Ada dua pipa spiral dan masing-masing memiliki empat lengkungan yang berbeda, dan dialiri oleh lumpur. Pada laju alir yang tinggi, efek geometri swirl dapat menjadi tekanan yang berlebih dikarenakan partikel padat. Konsentrasi padatan dari lumpur telah dibagi dengan 20Cw, 30Cw, dan 40Cw. Pitch per Diameter dibagi menjadi dua yaitu 5 dan 9. Hasilnya didapat dari dua buah pipa spiral pada kelengkungan yang maksimum, dan Computational Fluid Dymanics membantu mencari variabel yang dibutuhkan dari dua pipa spiral dengan masing-masing kelengkungan. Tujuannya yaitu mengetahui perbedaan antara kelengkungan yang akan menunjukkan optimalisasi terbaik di setiap pipa spiral.

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In this study, a spiral pipe 3 lobes that is flowed with slurry is optimized on different degrees of curvature and specified Reynolds Number. Flow of slurries consists of solid particles and fluid which then forms suspension. Suspension is caused by the characteristics of the flow such as the size of the particle, the distribution of particle, the concentrate of particle, the pipe geometry, and viscosity. The slurry with specified Reynolds Number is flown through two spiral pipes with each one has a different four degrees of curvature. On a high flow rate, the increase of the pressure for mixed flow solid-liquid (slurries) occurs higher than in pure fluids. Meanwhile during low flow rate, the effect of swirl geometry reduces the excessive pressure due to the solid particle. Concentration weight of slurry is divided to 20Cw, 30Cw, and 40Cw. P/Di is divided by 5 and 9. The result of experiment was found to be by using two spiral pipe and while the simulation using Computational Fluid Dynamics shows the result of eight curvature spiral pipe. It is expected that the difference between curvature will shows the best optimum condition for each spiral pipe."

"Sistem pengenalan wajah yang menggunakan pendekatan klasik sejauh ini belum dapat memberikan hasil optimal jika dihadapkan pada tantangan oklusi. Tantangan oklusi yang dikaji pada penelitian ini adalah saat wajah menggunakan masker. Jika seseorang menggunakan aplikasi sistem pengenalan wajah dengan harus membuka masker terlebih dahulu di tempat umum tentunya sangat berbahaya untuk keselamatan dan kesehatan semua pihak. Sehingga dibutuhkan sistem pengenalan wajah yang memiliki performa sistem yang tinggi dengan tantangan oklusi masker. Penelitian ini membangun sistem pengenalan wajah bermasker dengan pendekatan holistic dan partial face. Metode ekstraksi fitur yang digunakan adalah penggabungan metode kurvatur yang menggunakan turunan parsial orde satu dan dua dengan metode analitik seperti gray level co-occurrence matrix (GLCM) dan multi-resolution analysis (MRA) seperti transformasi wavelet diskrit (DWT), scale-space (SS) dan wavelet packet transform (WPT). Pada penelitian ini juga ditemukan kriteria baru (keterbaruan penelitian) yang dinamakan curvature best basis (CBB) untuk memilih basis pada algoritma best basis di dalam WPT. Kriteria baru pemilihan basis terbaik bersifat dinamis dan menggunakan nilai tertinggi dari ukuran statistik standar deviasi dari kurvatur rerata pada koefisien wavelet. Basis terbaik bekerja sebagai fitur terekstraksi yang bekerja di dalam sistem pengenalan. Penelitian ini dievaluasi menggunakan dataset RFFMDS v1.0, RFFMDS v2.0 EYB, dan UBIPr. Hasil penelitian menunjukkan bahwa sistem pengenalan wajah dengan tantangan oklusi masker berhasil dibangun menggunakan pendekatan holistic dengan akurasi pengenalan sistem sebesar 98,11% dan dengan pendekatan partial face dengan akurasi sebesar 98,80%. Kedua hasil akurasi terbaik ini diperoleh dengan metode curvature best basis. Performa sistem pengenalan yang menggunakan metode curvature best basis dengan pendekatan holistic maupun partial face menunjukkan performa tertinggi dibandingkan dengan performa penelitian sebelumnya.

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The face recognition system has not been able to produce satisfactory results when it applies classical approach to handle occlusion problems. This research evaluated masked face as the occlusion problem. If someone wants to use the face recognition system, he or she needs to take off the mask to accurately use the device. This becomes a risk for the safety to all party. The needs to have a stable high performance face recognition system has arisen. This research built the face recognition system with two approaches, holistic approach and partial face approach. The feature extraction method was combination of curvature of the first and second order of partial derivative and analytical methods such as gray level co-occurrence matrix (GLCM) and multi-resolution analysis (MRA) of discrete wavelet transform (DWT), scale-space (SS), and wavelet packet transform (WPT). A new dynamic criterion inside WPT has been proposed using the highest standard deviation from the mean curvature of wavelet coefficients. The single selected best basis works as extracted feature inside recognition system and it is called curvature best basis. The recognition system was evaluated using RFFMDS v1.0, RFFMDS v1.0 EYB, and UBIPr datasets. The results showed that the accuracy of the holistic approach was 98,11% and the accuracy of the partial face approach was 98,80% for the masked face recognition system. Both results derived from the proposed curvature best basis. The recognition system’s performance with curvature best basis overcome the results from previous works."

"Pada tahun 2016, terdapat 2.519 desa di Indonesia yang belum mendapatkan kebutuhan energilistrik. Turbin Pikohidro dapat menjadi salah satu solusi yang memungkinkan karena biayainvestasi yang murah, pekerjaan sipil yang sedikit, dan perawatan yang mudah dibandingkanSolar PV dan turbin angin. Turbin cross-flow adalah turbin impuls yang memiliki kelebihanseperti efisiensi yang stabil dalam berbagai kondisi debit, konstruksi sederhana, dan baik dalamskala portabilitas. Studi ini akan mengkaji pengaruh kelengkungan sudu terhadap performaturbin menggunakan metode Computational Fluid Dynamic. Variasi sudu dibuat menjadi rasiokelengkungan terhadap panjang sudu Rs/Ts diantaranya 0 ; 0,08 ; 0,17 ; dan 0,26. Berdasarkanhasil verifikasi, model turbulen RNG k - dipilih untuk mempredikasi pola aliran yang terjadikarena memiliki error yang lebih rendah dibandingkan dengan yang lain. Selain itu, modelturbulen k - RNG banyak dikembangkan pada studi impeler cross-flow baik mesin tenagamaupun kerja. Hasil komputasi mendapatkan sudu dengan rasio Rs/Ts = 0,08 menghasilkanefisiensi yang lebih stabil dan tinggi diduga karena olakan yang terjadi lebih kecil dibandingkanyang lain, sehingga sudu dengan rasio Rs/Ts = 0,08 direkomendasikan untuk digunakan padakondisi tinggi jatuh 2,71 meter dan debit 41 l/s.

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In 2016, approximately 2.519 village in Indonesia still didn rsquo t have sufficient access toelectricity. Picohydro turbine can be a proper solution because it has a low investation cost, few civil work, and easy to maintain compared to Solar PV and Wind Turbine. Cross flow isan impulse turbine that has an advantage such as stable efficiency in variable dischargecondition, simple construction, and high portability. To increase cross flow turbineperformance, this study will investigate the effect of blade curvature to the turbine efficiencywith CFD method. The blade variation will be stated as blade curvature to chord length ratio Rs Ts which consist of 0 0,08 0,17 and 0,26. Based on verification test, the k RNGturbulence model was chosen to predict flow pattern because it has a lower error compared toother turbulence model and the turbulence model has been commonly used in cross flowimpeller both on fan and turbine. The Resulted showed that blade with Rs Ts 0,08 yield thehighest efficiency because the it has the lower vortex compared to others. Therefore, the bladewith Rs Ts equal to 0,08 is recomended to use in condition of head 2,71 meter and discharge41 l/s."

"A study, by two of the major contributors to the theory, of the inverse scattering transform and its application to problems of nonlinear dispersive waves that arise in fluid dynamics, plasma physics, nonlinear optics, particle physics, crystal lattice theory, nonlinear circuit theory and other areas. A soliton is a localized pulse-like nonlinear wave that possesses remarkable stability properties. Typically, problems that admit soliton solutions are in the form of evolution equations that describe how some variable or set of variables evolve in time from a given state. The equations may take a variety of forms, for example, PDEs, differential difference equations, partial difference equations, and integrodifferential equations, as well as coupled ODEs of finite order. What is surprising is that, although these problems are nonlinear, the general solution that evolves from almost arbitrary initial data may be obtained without approximation. For such exactly solvable problems, the inverse scattering transform provides the general solution of their initial value problems. It is equally surprising that some of these exactly solvable problems arise naturally as models of physical phenomena. Simply put, the inverse scattering transform is a nonlinear analog of the Fourier transform used for linear problems. Its value lies in the fact that it allows certain nonlinear problems to be treated by what are essentially linear methods."