Djoko Suprijanto
Combinatorial Mathematics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10 Bandung, Indonesia

Published : 5 Documents
Articles

Found 5 Documents
Search

EFFECT OF POST HEAT TEMPERATURE TO HARDNESS AND MACROSTRUCTURE IN WELDED STELL ST 37 Subardi, -; Suprijanto, Djoko; Mahendra, Roza Lyndu R.
T R A K SI Vol 9, No 1 (2009): TRAKSI
Publisher : Universitas Muhammadiyah Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (138.798 KB) | DOI: 10.26714/traksi.9.1.2009.%p

Abstract

The present study aims to investigate the effect of post heat temperature of hardness andmacrostructure on the result steel welded St 37. Welded process with SMAW (Shelded Metal ArcWelding) and AC-DC current. Plate steel ST 37 welded of longitudinal, than heat treatment withtemperature various: 300°C, 400°C dan 500°C.Highest rate hardness 157,83 kg/mm2 on temperature treatment spesiment 500o cause haveferit grain boundary structure more and homogen so properties more hardness. The lows bendingstrength 43,51 kg/mm2 on raw material, cause have ferit structure and perlit so more soft properties.The micostuctrure welded area arround; ferit graind boundary, ferit widmanstatten, ferit acicularand perlit.
PENGARUH DIAMETER PENGEROLAN DINGIN TERHADAP KEKUATAN BENDING BAJA KARBON RENDAH Suprijanto, Djoko
T R A K SI Vol 11, No 2 (2011): TRAKSI
Publisher : Universitas Muhammadiyah Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (12170.975 KB) | DOI: 10.26714/traksi.11.2.2011.%p

Abstract

Baja St 41 merupakan baja karbon rendah yang mengandung karbon dibawah 0,30% banyak diaplikasikan untuk konstruksi umum. Pembetukan benda dengan pengerolan banyak dilakukan untuk pembuatan bejana maupun konstruksi penguatan dengan plat baja .Pada penelitian ini dilakukan proses pengerolan dingin, baja AISI 1015 setebal 7,65 mm dengan radius: 500, 1000, 2000 dan 3000 mm. Pengujian yang dilakukan adalah uji komposisi kimia, uji kekerasan uji struktur mikro , dan uji kekuatan bending dengan arah berlawanan dari arah pengerolan. Dari hasil pengujian tersebut dapat disimpulkan bahwa pengerolan akan meningkatkan kekuatan bending sampai pada ukuran tertentu. Setelah Iewat batas tertentu maka bahan akan luluh sehingga menurunkan kekerasan serta kekuatan bendingnya.Kata kunci: Baja St 41, Rolling, Ferit, Kekuatan Bending
The complete list of Ramsey $(2K_2,K_4)$-minimal graphs Wijaya, Kristiana; Baskoro, Edy Tri; Assiyatun, Hilda; Suprijanto, Djoko
Electronic Journal of Graph Theory and Applications (EJGTA) Vol 3, No 2 (2015): Electronic Journal of Graph Theory and Applications
Publisher : GTA Research Group, Univ. Newcastle, Indonesian Combinatorics Society and ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2030.362 KB) | DOI: 10.5614/ejgta.2015.3.2.9

Abstract

Let $F, G,$ and $H$ be non-empty graphs. The notation $F ightarrow (G,H)$ means that if all edges of $F$ are arbitrarily colored by red or blue, then either the subgraph of $F$ induced by all red edges contains a graph $G$ or the subgraph of $F$ induced by all blue edges contains a graph $H.$ A graph $F$ satisfying two conditions: $F ightarrow (G,H)$ and $(F-e) rightarrow (G,H)$ for every $e in E(F)$ is called a Ramsey $(G,H)-$minimal graph. In this paper, we determine all non-isomorphic Ramsey $(2K_2,K_4)$-minimal graphs.
ASYMPTOTIC STABILITY OF QUATERNION-BASED ATTITUDE CONTROL SYSTEM WITH SATURATION FUNCTION Septanto, Harry; Suprijanto, Djoko
International Journal of Electrical and Computer Engineering (IJECE) Vol 7, No 4: August 2017
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (513.754 KB) | DOI: 10.11591/ijece.v7i4.pp1994-2001

Abstract

In the design of attitude control, rotational motion of the spacecraft is usually considered as a rotation of rigid body. Rotation matrix parameterization using quaternion can represent globally attitude of a rigid body rotational motions. However, the representation is not unique hence implies difficulties on the stability guarantee. This paper presents asymptotically stable analysis of a continuous scheme of quaternion-based control system that has saturation function. Simulations run show that the designed system applicable for a zero initial angular velocity case and a non-zero initial angular velocity case due to utilization of deadzone function as an element of the defined constraint in the stability analysis.
Kode Siklis dari Sebuah Monomial Nopendri, Nopendri; Muchtadi-Alamsyah, Intan; Suprijanto, Djoko; Barra, Aleams
Jurnal Matematika Integratif Volume 15 No 1 (April 2019)
Publisher : Department of Matematics, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (351.748 KB) | DOI: 10.24198/jmi.v15.n1.20897.9-15

Abstract

Kode siklis merupakan salah satu topik riset paling aktif dalam teori koding karena memiliki banyak aplikasi pada sistem penyimpanan data dan komunikasi. Hal ini dikarenakan kode siklis memiliki algoritma encoding dan decoding yang efisien. Dalam makalah ini, dijelaskan tentang konstruksi kode siklis dari barisan yang dibangun oleh trace dari sebuah monomial atas lapangan hingga karakteristik dua. Beberapa contoh dari kode yang diperoleh ditampilkan pada makalah ini.