Monday, March 28, 2016

INI DIA VIDEO HEBOH REVI MARISKA YG SUDAH DIHAPUS DI INSTAGRAM !!

VIDEO REVI MARISKA DI INSTAGRAM YANG GUNDAH DITINGGAL NIKAH OLEH TEMMY RAHADI MANTAN REKAN MAIN LAWANYA DI SINETRON KOLOSAL INDOSIAR



Berikut Komentar-Komentar Pedas Dari Para Nitizen


baru tau aku, padahal kalo main sinetron dapet peranya kalem trs, ga nyangka taunya aslinya bgini ini beneran cuma karna di tinggal cowok dia jd kek gini? sama abang aja atuh sini neng, abang siap nampung. bagian terakhir ngakak. kalo orang Sunda pasti ngerti Dia itu gila beneren ya ora kenal itu sapa guys.. ga pernah liat di tv hiks2 Aq fanse kmi ini siapa sih.. ga terkenal ah pura-pura ga kenal ... biasanya nonton sinetron di indosiar ... :v ini siapa ga kenal Aku sukanya action sama cartoon klo gk tau ni artis brrti dulu kagak puny tv adek gw kls 6 sd ajah tau ,, wkwkwk #keliatan bgt #boongnya #alay kwowkwwo kategorinya olahraga ketek item Kumis Tionghoa hehehe... semoga kak revi bisa melewati inih semuaa dan bisa kembali main sinetron.. amiiin turut prihatin.... yg pen ting heppy lah Aq suka bgt sma qm vi,,,, cpt smbuh ea jngan kea gni kkk... ogb.. orang gilaaa baruu.. hahaha... tinggal di mana yaa? nie org oh krna cinta?? GWS dh buat itu Repi, apa mgkin sdh kena organ vital oleh itu cwo makanya jd kya bgitu?? subhanallah biar bisa tenar lg kyk marshanda.. kayaknya gk bakalan deh aku te2p suka m k revi.. aku percaya dia gk gila... di baik2 aj.. ku doa kan kk sukses selalu Lirik Lagu dandut nya ko bsa pas bngt sma keadaan dia sekarang haha 😂 haduh.... Sgthunya gila wah minta tlg tim kp nich Ya Allah.... sange gua liat doi... crottt... hahahahaha ya Allah kok kaya Sri utami Yang ke dua kelakuan revi yg Semarang kasian nasib nya kok jd ky gini kete ajh ,.. kk revi q ngefans banget sama kk revi.. kk harus kuat yah.... dia kena pelet revi " knapa dirimu jdi bgini... setingan Semungutt kaa Revi..hrus bs move on yhh Woooooww. Nice. Brapaan harga yg bginian. Smalem. Kayaknya uda di diskon nie. Maw dong nyobaain. :-) kak revi knp sih,, aku ngfans bgt ma kak revi, tp kok sekrng jdi gni cuma mampir doank A fans bngt sm revi.jgn gila smoga sj cm gsip ah gosip gmn sob....lah itu orangnya sndiri yg tampil d video. ikut sedih...dia artis kesuka'an gw. cantik bgt, aktingnya bgs bgt dan suaranya jg enak bgt d dgr kl dia lg brcakap cakap dlm aktingnya. duh knp jg gini ya...syg bgt kasian yah dr smp emang udh rusak,,pendidikannya udh ancur..ksian masa sih?seriusan? depresi itu trjadi krn tekanan batin n pikiran yg uda gk kuat ditahan. jd nya yaa kyk gni.. B!tch kasihan u mad bro? aduhhh kasihan anak orang. . ya allah kakak Revi kox seperti itu sekarang 😢 padahal aku ngefans berat sama kakak dri dlu mpe skrng 😢 semoga aja kakak revi ada dilindungan allah swt.dan semoga ISU2 itu gak bener.i Love u Revi Mariska Semangat 😘 Berapa nih tarifnya  jangan-jangan kita jodoh ... :v wow wow wow kami di semarang biasa yg disana pembayaran via tranfer pengiriman via paket bos besok kami jg ngirim ke jatim bos lg ada promo ambil 2 bonus 1 bos emane mbakk ayuu* 😃 artis skrang koq' tingkahnya Aneh2 y' ? apa krna tuntutan/trend ,;-< mantaap tetep sexi kasian msh muda kya gini..RIp aja deh hahahaha bening banget dadanya Astgfirullh..sngtt d sygkn.. Pdhl dulu Trknl..udh cntk..Sopn..ko skrg bgni y.. ya alloh kk refi kenafh ku sayg sama kk refi
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Friday, August 21, 2015

Boundary Conditions and Loading

Contoh :


Defleksi dan maksimum tekanan Von Mises dapat dipelajari dengan distribusi tekanan pada balok (lihat contoh masalah), dan pertanyaan apakah balok menghasilkan pembebanan?
Masalahnya meminta balok hanya didukung pada kedua ujung yang akan memungkinkan untuk UX = UY = UZ = 0, tapi untuk rotasi nol di sekitar sendi akhir (ROTX = ROTY = Rotz).
Namun, nol kendala perpindahan ditempatkan di kedua ujungnya, jika diterapkan pada wajah, yang kendala kaku (dijepit), dan tidak hanya didukung. Jika menggunakan elemen 3D, karena unsur-unsur ini hanya UX, UY, UZ sebagai DOF, dan itu akan sulit untuk membuat sendi hanya didukung.

Dalam dokumen berikutnya, asumsi dibuat bahwa mesh digunakan untuk model balok adalah 3D (elemen hexahedral) dan kendala di akhir yang kaku (beam Tertanam-dijepit dibandingkan berengsel berengsel).
Tekanan memuat besarnya 150 psi, dan permukaan aplikasi (lihat flange merah pada Gambar 1), serta kendala dijepit ditunjukkan pada Gambar 1.
Boundary Conditions and Loading


Jawaban :

Gambar 2 menunjukkan deformation distribution dan the maximum deformation terjadi di tengah-tengah balok dan ditemukan di 0,133.


Total Deformation (in)

The maximum mises stress terjadi pada supports (lihat Gambar 3) dan menjadi 30,2 ksi.

Von Mises Stress (Psi)



Verifikasi Jawaban :

Deformasi maksimum terjadi pada titik tengah dari balok dan dihitung secara analitis menurut rumus dari Gambar 4. L adalah panjang, E, adalah modulus Young dan saya momen inersia sekitar sumbu x dan ditemukan dari tabel direferensikan dalam pernyataan masalah menjadi 659 in4.
Kuantitas w adalah gaya per satuan panjang (Persamaan 1):



W=pressure * width of flange=150 pounds per square inch*7.07 in=1060.5 pounds/inch (1)

Jadi defleksi maksimum di tengah balok ditemukan, dengan asumsi kondisi batas-dijepit dijepit (Persamaan 3):


Δ = w * L4 / (384 * E * I) = (150 psi * 7.07in * (120 in) 4) / (384 * 1,39 * 107 * 659 in4) = 6.25e-02 di (2)


Dengan membandingkan hasil analisis untuk defleksi maksimum 0,13 inci yang diperoleh dalam FEA, kesalahan relatif adalah (Persamaan 3):

e= (0.13-0.0625)/0.13 *100=50%
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Friday, May 29, 2015

REVERSE ENGINEERING SEBAGAI BASIS DESAIN PENGEMBANGAN MOBIL MINI TRUK ESEMKA

REVERSE ENGINEERING SEBAGAI BASIS DESAIN PENGEMBANGAN MOBIL MINI TRUK ESEMKA
Bambang Waluyo Febriantoko1
1Universitas Muhammadiyah Surakarta Jurusan Teknik Mesin
Jl. A. Yani Tromol Pos 1 Pabelan Surakarta
E-mail: Bambangwf@gmail.com
Direview aleh : Indarr Luh Sepdyanuri
Institut Sains & Teknologi AKPRIND Yogyakarta Jurusan Teknik Mesin
Jl. Kalisahak No. 28 Kompleks Balapan Tromol Pos 45 – Yogyakarta 55222



ABSTRAK
Riset ini dilaksananakan dengan cara membongkar mobil mini truk esemka yang mengambil basis mini truk impor dari China, dilakukan pada cabin dan di dokumentasi pada setiap bagian, dilanjutkan pada interior bagian cabin, kemudian masuk pada bagian rangka, suspensi, gardan, dan bak truk. Tahap selanjutnya adalah klasifikasi bagian komponen berdasarkan induk dari assembly yang utuh, pemberian nama dan pemberian kode. Pada bagian rangka, pengambilan data dapat dilakukan dengan cara pengukuran langsung pada bagian komponen. Pengukuran ini dilakukan dengan bantuan jangka sorong, micrometer dan radius gauge. Sketsa dibuat berdasarkan data dari pengukuran langsung yang akan digunakan sebagai acuan dalam pembuatan gambar CAD di komputer. Pada bagian bak angkut juga dilakukan pengukuran secara manual dengan komponen yang lebih sedikit dari pada bagian chasis. Pada bagian cabin Pengukuran dilakukan dengan menempelkan resin yang dicampur dengan fibreglass pada bagian komponen yang akan diukur. Metode ini akan membentuk cetak negative dari komponen yang selanjutnya akan diambil data tiap komponen. Pengambilan data koordinat dari surface kontur komponen kabin dilakukan dengan membuat mesin pengukur 3 Dimensi pada koordinat X, Y dan Z. Data yang didapatkan pada 3 koordinat akan digunakan didalam software CAD untuk membentuk kurva sebagai acuan pembentukan surface. Disain ulang dengan software CAD dilakukan di Laboratorium CAD/CAM/CAE UMS dengan melakukan gambar komponen dalam 3 Dimensi. Setelah gambar komponen 3 Dimensi selesai maka dilakukan penyusunan disain Sub Assembly dan selanjutnya disain Assembly. Pengecekan disain per komponen dapat dilakukan pada waktu Assembly meliputi relation, interference, concentric, paralel, coincident dll. Jika terjadi ketidak sesuaian maka pengecekan dilakukan dari awal penelitian. Disain assembly yang telah disetujui selanjutnya dilakukan pembutan gambar 2D dengan pemberian ukuran, BOM (Bill Of Material), tanda pengerjaan dan kode komponen. Tahap akhir yaitu penyusunan Dokumentasi Blue Print mobil mini truk esemka.

Kata Kunci: Reverse engineering, cabin, interference

.
PENDAHULUAN
Perlahan namun pasti telah bermunculan produk produk nasional berupa mobil buatan Indonesia. Salah satunya GEA yang diproduksi oleh PT Industri Kereta Api (INKA), Mobil Arina yang dikembangkan oleh Unes Semarang, Tawon yang dikembangkan oleh PT. Super Gasindo Jaya, Marlip yang dikembangkan oleh LIPI dan masih banyak lagi. Mobil nasional Esemka yang diawali oleh produk Digdaya merupakan mobil pengembangan Sekolah Menengah Kejuruan (SMK). Produk ini dibuat dengan memberikan rangka dan mesin dari Direktorat Pembinaan SMK untuk kemudian dibuat bodi dan interiornya. Pengembangan ini dilakukan oleh 23 SMK utama, tiga diantaranya yaitu SMK Singosari Malang bekerja sama dengan Nasional Motor, SMK Trucuk bekerja sama dengan Kiat Motor, dan SMK Muhammadiyah 2 Borobudur yang telah memiliki unit karoseri sendiri. Pengembangan selanjutnya adalah proses perakitan mobil import dari China dalam bentuk terurai untuk dirakit menjadi mobil utuh. Dari pengembangan inilah maka muncul gagasan untuk membuat mobil esemka secara utuh yang berbasis pada mobil China.
Melalui penelitian ini Universitas Muhammadiyah Surakarta berupaya memberikan kontribusi terhadap pengembangan industri otomotif di Indonesia. Hasil penelitian dan kerjasama dengan Industri telah banyak memberikan kontribusi pada pengembangan dunia industri khususnya bidang otomotif. Riset dalam rekayasa otomotif diharapkan mampu memberikan transfer teknologi kepada SMK di seluruh Indonesia dalam hal disain dan pembuatan komponen otomotif untuk mendukung program mobil esemka mini truk yang sedang digulirkan oleh Direktorat Pembinaan SMK. Tujuan dari penelitian ini adalah membuat disain mobil mini truk esemka dari basis pengembangan mobil rakitan asal China.
Reverse Engineering
Reverse engineering didefinisikan sebagai: “menganalisa suatu sistim melalui identifikasi komponen-komponennya dan keterkaitan antar komponen, serta mengekstraksi dan membuat abstraksi dan informasi perancangan dari sistim yang dianalisa tersebut” (Wibowo D.B, 2006). Konsep reverse engineering di industri merupakan suatu langkah meniru produk yang sudah ada (dari produsen lain) sebagai dasar untuk merancang produk baru yang sejenis, dengan merubah disain, memperkecil kelemahan dan meningkatkan keunggulan produk dari para pendahulunya (Raja V., 2008). Kegiatan yang dilakukan meliputi 5 tahap, yaitu : (a). Kegiatan Pembongkaran Produk, (b). Kegiatan penggabungan Komponen, (c). Kegiatan pembandingan (d). Proses disain produk baru serta (e). Pembuatan Prototipe Produk.
Menurut Bagci (2009), Reverse Engineering didefinisikan sebagai evaluasi yang sistematik dari produk yang sudah ada dengan tujuan melakukan duplikasi, termasuk didalamnya disain dari komponen baru, duplikat yang sudah ada, pembuatan ulang komponen yang rusak, dan peningkatan kepresisian produk.
Panchetti dkk (2010) mendefinisikan aplikasi dari reverse engineering dalam area industry sebagai berikut :
-        Disain dari komponen baru : pembuatan disain komponen baru dari komponen yang sudah ada.
-        Reproduksi komponen : pembuatan komponen karena sudah tidak diproduksi lagi.
-        Perbaikan dari komponen yang rusak : permukaan komponen yang rusak diukur dan rekronstruksi kembali menggunakan CAD dan dibandingkan dengan komponen yang sudah ada.
-        Pengembangan model yang lebih presisi.
-        Observasi dari data numeris : pemrosesan data dari model yang sudah ada di dalam CAD kemudian membandingkan dengan model terdahulu.
Corbo dkk (2004) tahapan proses dari reverse engineering meliputi :
-        Pengambilan data fisik dari produk : pengambilan koordinat data pada sumbu X, Y, Z dari produk relatif terhadap titik referensi.
-        Managemen data dari kumpulan koordinat : pensortiran data koordinat sehingga didapatkan koordinat yang sesuai.
-        Rekonstruksi dari surface : Penggunaan software CAD untuk mengolah data koordinat menjadi bentuk surface dengan persamaan kurva NURBS
-        Pembuatan produk CAD : rekonstruksi surface untuk membuat produk digital gambar CAD
-        Validasi model produk : analisis fungsional dan estetika produk dengan pembanding produk awal.

METODE

Gambar 1. Diagram Alir Reverse Engineering
Penelitian yang dilakukan ini diawali dengan menggunakan data hasil analisis awal tim yang telah melakukan kerjasama dengan SMK Muhammadiyah 2 Borobudur.
Gambar 2. Mobil mini truk impor dari China
Pembongkaran mobil mini truk yang mengambil basis mini truk impor dari China (Gambar 2), dilakukan pada cabin (Gambar 4)dan di dokumentasi pada setiap bagian, dilanjutkan pada interior bagian cabin, kemudian masuk pada bagian rangka (Gambar 3), suspensi, gardan, bak truk (Gambar 5) dan seterusnya.
Gambar 3. Kegiatan pembongkaran sasis mini truk
 
Tahap selanjutnya adalah klasifikasi bagian komponen berdasarkan induk dari assembly yang utuh, pemberian nama dan pemberian kode. Pada bagian rangka, pengambilan data dapat dilakukan dengan cara pengukuran langsung pada bagian komponen. Pengukuran ini dilakukan dengan bantuan jangka sorong, micrometer dan radius gauge (Gambar 6 dan 7). Sketsa dibuat berdasarkan data dari pengukuran langsung yang akan digunakan sebagai acuan dalam pembuatan gambar CAD dikomputer. Pada bagian bak angkut juga dilakukan pengukuran secara manual dengan komponen yang lebih sedikit dari pada bagian chasis.

Pengukuran bagian cabin merupakan komponen tersulit, yang tersusun oleh bentuk surface dari pelat baja. Dikarenakan mobil ini unitnya terbatas di Indonesia dan bersifat pinjam, maka tidak dapat dilakukan pembongkaran tiap komponen secara menyeluruh pada bagian yang telah disatukan oleh proses spot welding. Pengukuran dilakukan dengan menempelkan resin yang dicampur dengan fibreglass pada bagian komponen yang akan diukur (Gambar 9). Metode ini akan membentuk cetak negatif dari komponen yang selanjutnya akan diambil data tiap komponen. Pengambilan data koordinat dari surface kontur komponen kabin dilakukan dengan membuat mesin pengukur 3 Dimensi pada koordinat X, Y dan Z (Gambar 8). Data yang didapatkan pada 3 koordinat akan digunakan didalam software CAD untuk membentuk kurva sebagai acuan pembentukan surface.


Gambar 9. Pengambilan data koordinat pada komponen cetak dari resin
Reverse engineering dilakukan di Laboratorium CAD/CAM/CAE UMS dengan melakukan gambar komponen dalam 3 Dimensi (Gambar 10, 11 dan 12). Setelah gambar komponen 3 Dimensi selesai maka dilakukan penyusunan disain Sub Assembly dan selanjutnya disain Assembly. Pengecekan disain per komponen dapat dilakukan pada waktu Assembly meliputi relation, interference, concentric, paralel, coincident dll. Jika terjadi ketidak sesuaian maka pengecekan dilakukan dari awal penelitian.

Gambar 10 Disain cabin dalam software CAD Solidworks 2011

Gambar 11 Disain rangka dalan software CAD Solidworks 2011

Gambar 11 Desain Assembly dalan software CAD
Disain assembly yang telah disetujui selanjutnya dilakukan pembutan gambar 2D dengan pemberian ukuran, BOM (Bill Of Material), tanda pengerjaan dan kode komponen. Tahap akhir yaitu penyusunan Dokumentasi Blue Print mobil mini truk esemka. Pembuatan prototipe dimulai dengan membuat kabin metode karoseri, dilanjutkan pada pembuatan rangka beserta dengan braketnya dan pembuatan bak angkut (Gambar 12 dan 13). Pada tahapan ini dilaksanakan oleh SMK Muhammadiyah 2 Borobudur Magelang. Untuk mesin digunakan mesin esemka 1500 cc yang telah tersedia sebelumnya.

Gambar 14 Prototipe Mini Truk
KESIMPULAN
Metode Reverse Engineering mempercepat pengembangan produk dengan mengurangi kegiatan uji coba ukuran produk terutama masalah ukuran ergonomi. Pengembangan produk dapat dilakukan dengan merubah bentuk estetika dan ketersediaan komponen pendukung yang ada.
DAFTAR PUSTAKA
Bagci E., 2009, Reverse Engineering Application for Recovery of Broken or Worn Parts and Remanufacturing : Three Case Studies, Advances in Engineering Software, 40, pp 407-418
Corbo P., Germani M., Mandorli F., 2004, Aesthetic And Functional Analysis for Product Model Validation in Reverse Engineering Aplication, Computer Aided Design, 36, pp 65-74
Panchetti M., Pernot J.P., Veron P., 2010, Towards Recovery of Complex Shapes in Meshes Using Digital Images for reverse Engineering Aplication, Computer Aided Design, 42, pp 693-707
Raja, V., 2008, Reverse Engineering, Springer Verlag London Wibowo, Dwi Basuki dan Kurdi Ojo, 2005, Desain Drilling Jig Untuk Alat Bantu Produksi Housing Reducer Gear, Jurnal Rotasi, Vol.7 Nomor 1, Jurusan Teknik Mesin UNDIP, Januari 2005



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Friday, May 22, 2015

A Milling Application - Direct Interface Integration of CAD and CAM Software

V. • . a Srlmvasan. G.W. Fischerb  "Centro Inc., North Liberty, IA 52317 bDepartment of Industrial Engineering, The University of Iowa, Iowa City, IA 52245-1527 

Abstract 
Computer Integrated Manufacturing (CIM) is considered to be a strategy for planning, implementing, and integrating many functions in a manufacturing organization. A concurrent engineering design environment encourages multi-disciplinary communication of design ideas very early in the design cycle. A contemporary approach to realize the benefits of concurrent engineering design uses automated computer systems and a plethora of computer aided engineering tools. Methods are needed to integrate these tools, as most of them are stand-alone software tools that do not communicate to each other effectively. This paper presents a methodology that can integrate an advanced CAD software and a process planning software. A milling application example is used to demonstrate how the primary machining parameters can be calculated and directly imported to the CAD software, thus creating a seamless preparation of the NC part program. 
Keywords: CAPP, CAD/CAM, CIM, Process Planning, Concurrent Engineering, Machinability Data 

1. Introduction 
The need for the availability of knowledge to the designer from different functional perspectives is of paramount importance in arriving at an optimized design of any product. A concurrent engineering design environment encourages multi- disciplinary communication of design ideas very early in the design cycle and provides a mechanism to make such knowledge available to the designer. A contemporary approach to realize the benefits of a concurrent engineering design uses a plethora of computer aided engineering tools. These tools have been developed, through a major investment of time and money, but are only usable in a specific computer environment. The costs for software vendors and internal developers to rewrite their application programs and support several versions are usually prohibitive. This paper presents a methodology that can integrate an advanced CAD software and a process planning (CAM) software. A milling application example is used to demonstrate how the primary machining parameters can be calculated and directly imported to the CAD software, thus creating a seamless preparation of an NC part program. Section 2 of the paper stresses the need for making knowledge available to the designer from several functional perspectives. Section 3 presents the proposed methodology and its advantages. The specifics of the integration are discussed by means of an example in Section 4. Conclusions are outlined in Section 5. 

2. Knowledge and the design process 
Ideally, the designer wants to arrive at a product design that optimally satisfies all design constraints while minimizing lead- from different design perspectives, such as dynamics, maintainability, structural analysis, and reliability. These analyses satisfy product related design decisions. Process related design decisions involve selecting the most appropriate manufacturing process, and optimizing the process parameters for the chosen manufacturing process (e.g., optimizing speed, feed, and depth of cut for a milling process). In order to perform the daunting task of optimizing the product design parameters, the designer needs access to tools that can effectively provide information on the various perspectives. The research effort at the Center for Computer Aided Design (CCAD), The University of Iowa, is an excellent example of an effective integrated computer-based environment that can support a concurrent engineering design process[l]. Fig. 1 shows an illustration of the different perspectives of product design that can be considered in the CCAD system. 

The research presented in this paper describes an attempt to develop an Integrated Concurrent Engineering Environment (ICEE) that can support the analysis of product design from several design perspectives, e.g., dynamics, maintainability, structural analysis, reliability, and manufacturability. Manufacturing planning analyses are very critical to successful production of a product. It is reasonable to believe that computer aided tools that analyze design from the manufacturing perspective will soon become a necessary part of any concurrent engineering design environment. The methodology described here provides the designer with knowledge about a particular manufacturing process by means of interfacing a milling process planning software with an existing, state-of-the-art, 3D CAD modeler. 

3. Proposed methodology and its advantages 
Almost all of today's concurrent engineering efforts use automated engineering tools distributed throughout an organization's design development teams. In contrast to the concurrent engineering philosophy, these distributed Computer Aided Engineering (CAE) tools have a tendency to form a fragmented and sequential design environment rather than an integrated and simultaneous design environment. The reasons for such a fragmented design environment involving CAE tools is presented next. 
3.1. Reasons and sources off ragmentation 
Much research, with the ultimate goal of automating some aspect of contemporary concurrent engineering, exists. These efforts usually result in a CAE tool that can automate a particular function in the design process. However these tools are mostly stand-alone software tools with little or no scope for successful integration with other tools in an integrated design environment. Such fragmentation created among the CAE tools exists with regard to multiple perspectives. One source of this fragmentation stems from the internal design data formats and data content inherent in CAE tools. The methodology adopted by each CAE tool in storing, processing, and manipulating design data is often unique and the data formats created are proprietary to the CAE tool vendor. Therefore, the simultaneous sharing of product/process design data and information among distributed CAE tools becomes difficult, if not impossible. Use of standard file formats that can be interpreted and processed by multiple CAE tools is one approach to solving this fragmentation problem. Examples of common standard data exchange formats are IGES and DXF. Even though standard file formats may provide a solution to the design data formatting problem, the problem of different data content among CAE tools still persists. For example, a manufacturing process planning CAE tool manipulates and processes completely different information than a reliability analysis CAE tool. Therefore, even if a standard data file format is used, design data would continue to be fragmented as it would prove impossible for the reliability analysis tool to completely process the design data supplied by the manufacturing process planning tool and vice versa. In an attempt to provide a solution to this fragmented data content problem, the PDES/STEP standard has been developed by the International Standards organization (ISO)[2]. However, the PDES/STEP standard is not yet mature enough to be accepted in the industry, and until it is, the data fragmentation problem among distributed CAE tools will continue to exist. The inability of many CAE tools installed in design environments to communicate with one another forms yet another source of fragmentation among distributed CAE tools. Even if a CAE tool is able to completely understand and process all of the design data supplied by other CAE tools, design data must still be physically transferred between the applications. Hence, a communication medium must exist among CAE tools in order to have an integrated design environment. Unless an automated common communication medium over which a set of CAE tools can communicate exists, a fragmented, sequential design environment will remain. Ideally, to form a concurrent engineering design environment, CAE tools need to satisfy the following requirements[3]. 1. All tools should share the same data management facilities. 2. All tools should directly interact at the data processing level. 3. All tools should be alerted to incremental changes in design data. 4. All tools should have a common system level user interface. 
3.2. Direct Interfacing 
Even though numerous research efforts are underway to make the CAE tools satisfy the requirements outlined above, it will take significant time before such tools become a reality. However, it cannot be denied that individual CAE tools are robust by themselves and fulfill very effectively the function for which they are created. Hence it is a loss that such effective tools are in isolation and cannot effectively communicate with each other. When analyzing the design of a product to make process related design decisions, a particular manufacturing process needs to be selected from a set of competing manufacturing processes that satisfy a prescribed set of constraints. The constraints can either be cost driven or production driven. Although CAE tools do exist for performing the computer aided design of the product, these tools do not completely support the analysis of the suitability of a process from, say, a cost perspective. Such an analysis, for the operation being considered, could involve selecting the appropriate machine tool, cutting tools, and primary process parameters, such as feed, speed and depth of cut. However, tools that let the designer perform process analysis often have primitive modeling capabilities. Increasingly, it is felt among manufacturing software users that some amount of insight and provision for access should be provided to the database and implementation strategy of commercial CAD/CAM systems. This is because process planning is such a complex task that no universal solution can satisfy the needs of all users. Therefore, the next best option is to provide them some kind of access to the database of the CAD models that will enable them to write their own code to be interfaced with the CAD modeler. Fig. 2 shows such an environment where individual tools can be interfaced with a CAD modeler having interfacing capabilities. The question of what type of CAD modeler and what types of process planning tools need to be interfaced needs further discussion. Even though 




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LOST WORK: A MEASURE OF THERMODYNAMIC EFFICIENCY

NOEL DE NEVERS and J. D. SEADER 
Department of Chemical Engineering, University of Utah, Salt Lake City, UT 842 12, U.S.A.
Abstract-The introduction of “lost work” into the statement of the second law of thermodynamics allows us to combine it with the lirst law to obtain a statement of extreme breadth and generality. Because the combined tirst- and second-law statement defines reversible work, all other widely used statements of minimum or maximum work can be shown to be restricted cases of this combined statement. With this combined statement, we can calculate thermodynamic efficiencies of all processes, including not only those conventionally treated-which are large work producers or consumers-but also those that do not have work production or consumption as their goals (as in absorption refrigerators or distillation columns). The results obtained this way, for example with turbines, are not the same as the conventional “isentropic efficiency” definition, but are more thermodynamically sound and much more practical for turbines whose outlet temperatures are far removed from the ambient temperature. The combined first- and second-law statement leads naturally to the availability function and the batch availability function rather than to the availability. For practical process problems, where prime movers are not the most important concern, the availability function is a much more useful and practical quantity to utilize than the availability.

INTRODUCTION The second law of thermodynamics is not new. It has been known in all of its important aspects since at least 1870. The objective of this paper and this conference is to seek out the most satisfactory ways of applying the second law to practical problems. Although the public is slowly being educated to think about “the energy crisis”, we technical people understand perfectly well that the real problem is “the entropy crisis”. The energy of the earth is changing very little, if at all, and if solar radiation and outgoing heat flux are balanced, it is not changing at all. Energy is conserved (i.e. the first law is obeyed) in all of our most wasteful uses of fuels and electricity (e.g. refrigerated swimming pools in hot climates, the lights of Las Vegas, etc.). Our problem is that our low-cost sources of low-entropy materials from which we can extract useful work to drive our vehicles or to power our factories or to heat our homes have become inadequate for our current consumption. We will probably be well advised not to confuse the public by telling them about the “entropy crisis”, but certainly all technical people must be aware of this. The purpose of this conference is to evaluate various ways of applying the second law of thermodynamics to the calculation of thermodynamic efficiencies, There have been many proposals, of which the most commonly used method is “availability analysis”.‘-3 In this paper, we extend the development of a less well-known approach involving “lost work”. If all of these methods are used properly, they must all give the same answer since the second law is unambiguous. Thus, the criteria for selecting the best procedure to evaluate thermodynamic efficiency should be: (1) best ease of use, (2) best degree of correspondence with the viewpoint and background of intended users, and (3) greatest breadth of application. On these grounds, we believe that the lost work approach is superior to other approaches in common use. 

THE SECOND LAW OF THERMODYNAMICS AS AN ENTROPY BALANCE WITH LOST WORK 
Classical formulations of the second law of thermodynamics take the form of inequalities. The first form proposed was for closed systems where Qi refers to the heat transfer across a portion i of the boundary of the system and Ti is the corresponding temperature of that part of the boundary. Except for isothermal systems, T is not uniform, but has different values at different parts of the boundary. As will be shown later, the selection of the system, and therefore its boundary, is important and requires careful consideration. In general, so that all irreversibilities occur within the system, the boundary is placed such that values of Ti correspond to the various heat reservoir temperatures. For open systems, we must include the possibility of material flowing across portions j of the system boundary. Thus In both equations, the summations are algebraic so that a flow out of the system has a negative value of Q or m. Here, and in subsequent equations, the A(ms& implies either that the system has uniform intensive properties or that the product of mass times the specific entropy (or other intensive property functions used later) is obtained by an integration over the entire mass contained within the system. In addition, the C(ms)j and X(QJTi) terms imply either that the flows across the boundaries are uniform with respect to all variables or that the terms correspond to integrations over the boundaries of the system. The details of such integrations are given by Bird.4 A more useful equality form of Eq. (2) is obtained by adding a term for the irreversible entropy increase, to give Denbigh’ stated that introducing such an irreversible entropy increase term to convert the second law from an inequality to an equality is largely due to de Donder. Although Denbigh also utilized an equality form of the second law, he applied it to both the system and the surroundings. As shown later, the procedure adopted here leads to an equation that is more readily applied than the equation developed by Denbigh. Any discussion of thermodynamic or second-law efficiency must be concerned with ASi,,. If it is zero, the process is reversible and is as efficient as is theoretically possible. The larger ASi,, all other things being equal, the less efficient the process. This form of the second law also allows US to formulate this neat verbal statement of it: ASi, is positive in the real world, zero in the theoretical reversible world, and negative in some impossible worlds. The main idea of this paper is to show that, if we define a new quantity called “the lost work” as and introduce it into Eq. (3), we will have a very powerful and convenient method of assessing the thermodynamic efficiency of processes. In this equation, T,, is the temperature of the infinite surroundings, normally taken as the temperature of the nearest large body of ambient water like a river, lake, or ocean, Because they are assumed to be infinite in size, infinite surroundings are an ultimate heat source or sink that is always available and does not need to be restored or replenished. Although one could work totally with ASi,, or perhaps mentally substitute T&Sirr whenever LW appears, we believe that formulations in terms of LW are simpler, easier to use, and more intuitively satisfying than any other formulation of the second law now in common usage. Indeed, as we show later, lost work is exactly what the term implies-work that is irreversibly lost. Table 1 lists the most common ways in which irreversible entropy increases (ASi,) occur. Conceptually, all of these are equivalent to the conversion of work to heat. Hence, at least as early as 1950: the idea of “lost work” had been used as a measure of irreversibility or of the degradation of energy from more useful to less useful forms. As we discussed in an earlier paper,’ there are two definitions of lost work in common usage. The first one indicates that lost work is simply the amount of work that is irreversibly converted to heat. The other, which we consider the superior definition, indicates that lost work is not only the amount of work that is irreversibly converted to heat, but also includes the additional work that must be transferred to the system to offset the consequences of this degradation. This idea is illustrated in Fig. 1. Here, we see an irreversible process occurring in a system that may be open or closed, where the irreversible work input is lost. In addition, a Carnot refrigerator offsets this irreversible work conversion by removing the incremental heat and rejecting it to the surroundings at To so as to restore the system to its original state. Lost work, as we believe it should be defined, is the sum of these two works. One may also show that lost work is equivalent to the incremental heat that must be rejected to the infinite surroundings at T,, due to irreversibilities (see Appendix 1). Since thermal energy in the heat reservoir at T,, cannot be put to any practical use, this is energy that has been degraded to its ultimate uselessness. 

THE ADVANTAGES OF THE LOST WORK CONCEPT 
(1) The lost work concept allows us to formulate the second law in an equality form rather than in an inequality form 
AS =A(ms),,,=~~+~(,,).+~. sys iZ i ’ 0 
(5) 
This is merely a restatement of Eq. (3), in which the ASi, term is replaced by Eq. (4). However, this substitution replaces a term of low intuitive content with two others. One is an external variable that changes little from location to location, and the other is directly related to external variables and is the term of practical significance. Lost work is the equivalent of the incremental extra electric power that must be purchased to offset irreversibilities, but there is no such simple intuitive interpretation of ASir,. (2) We can multiply Eq. (5) by TO, subtract it from the general energy balance, and then rearrange to produce the combined statement form 
(‘W,“W)=X[m(h-To~)lj+~ (I-~)Q-b[m(~-~~~)l,,,. (6) I 
Here we have followed the thermodynamic sign convention that heat flowing into the system is positive, and work flowing out of the system is positive. We can further simplify this result by introducing a combination of thermodynamic variables, often defined on a unit mass or mole basis as the “availability function”, or 
b=h-Tos=u+Pv-Tos. (7) 
This function and symbol-but not name-were apparently introduced into engineering by Keenanr’ although it had been proposed earlier by others in different forms? Haywood calls it the “steady-flow availability” function, while Faires and Simmang” refer to it as the “availability” or “Darrieus” function. However, since “availability function” seems to be its most common name, it will be used here. It is unfortunate that the word “availability” appears in its name, however, since it leads to confusion with what many authors,**“*” in writing of a steady-state, steady-flow process, have called the “availability” or (h - Tos) - (ho - Toso) in the absence of potential and kinetic energy effects Substituting Eq. (7) into Eq. (6), we obtain 
(CW,+LW)=z(mb)j+T (1-~)8_P[m(b_Pv)l,v,. J I 
The term on the far right contains the combination (b - Pv), which is logically called a “batch” or “nonflow” availability function. Haywood’ suggests that it should have the symbol a, but, to our knowledge, no symbol or name has been widely adopted for it. We can easily divide Eq. (8) by the time change At to obtain the equivalent form in terms of power, mass flow rates, heat flow rates, and time rate of change of the system. (3) We can see that, in this combined statement, the two work terms of actual external work and lost work appear together. Their sum is equal to the reversible work of a process that has the same material flows in and out and the same heat exchange at all temperatures other than T,, so that 
W,,,=ZW,+LW. (9) 
This is an extremely broad and powerful result. It means that, for any real process where we can define the state of the system before and after any system change, the mass flows or mass flow rates into and out of the system, and the heat flow rates and temperatures at which heat flows into and out of the system, we can directly and unambiguously compute the work flows for a reversible process. From the difference between that work flow and the actual work flow, we can compute the lost work. (4) With this lost work definition, we can easily compute thermodynamic efficiencies for processes that involve exchange of work with the surroundings and for those that do not. For processes that exchange work with the surroundings, and whose purpose is either to produce work or to consume work, the definitions are simply 
(10) 
(11) 
(5) We can see that efficiency definitions given in Eqs. (10) and (11) are not the same as the ones commonly shown in many engineering thermodynamics textbooks. For example, Eq. (10) does not lead to the conventional definition of the “isentropic efficiency” of a turbine, but to a much more powerful definition. The conventional definition, according to Van Wylen and Sonntag,” is 
W h,-h2 =e=- qturbine mechanical w, h, _ h2,) (12) 
which is a mechanical efficiency definition. The initial state and the final pressure of the real and reversible (isentropic) processes are chosen to be the same. This fixes the outlet temperature and entropy of the isentropic process. The outlet temperature of the real turbine process can be arbitrarily estimated or determined experimentally. We may see this from Fig. 2, where a conventional Mollier diagram representation of the process path of an adiabatic steam turbine with negligible kinetic energy changes is shown. The initial state is 1; the final actual state is 2; and the reversible path leads from 1 to 2,. In contrast, the definition which follows from Eq. (9) is a thermodynamic definition, where the inlet and outlet states are the same for both the real and the reversible turbines. If we apply Eq. (10) to the same system, we see that 
%urbine thermodynamic 
=e h-h_ =-_ hl-hz W e,, h-h h,--hz- Z-ob,- ~2)’ 
(13) 
To see the relation between the thermodynamic turbine efficiency and the more common mechanical turbine efficiency, we define 
Tavg = h2 - h2, s2-82,’ 





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UNIQUENESS AND SYMMETRY IN PROBLEMS OF OPTIMALLY DENSE PACKINGS | Mathematical Physics Electronic Journal

LEWIS BOWEN, CHARLES HOLTON, CHARLES RADIN, AND LORENZO SADUN

Abstract.
Part of Hilbert’s eighteenth problem is to classify the symmetries of the densest packings of bodies in Euclidean and hy- perbolic spaces, for instance the densest packings of balls or sim- plices. We prove that when such a packing problem has a unique solution up to congruence then the solution must have cocompact symmetry group, and we prove that the densest packing of unit disks in the Euclidean plane is unique up to congruence. We also analyze some densest packings of polygons in the hyperbolic plane.
I. Introduction
The objects of our study are the densest packings, particularly of balls and polyhedra, in a space of infinite volume; for a survey see the classic texts [Feje] and [Roge], and the review [FeKu]. Most interest has centered on densest packings in the Euclidean spaces En, notably when the dimension n is 2 or 3, but we will see that packing prob- lems in hyperbolic spaces Hn can clarify some issues for problems set in Euclidean spaces so we consider the more general problem in the n dimensional spaces Xn, where Xn will stand for either En or Hn. (It would be reasonable to generalize our considerations further, to sym- metric spaces, and even to include infinite graphs, but as we have no noteworthy results in that generality we felt it would be misleading to couch our considerations in that setting.) We will give results of two types. We prove (Theorem 2) that when a packing problem in Xn has a solution which is unique up to congruence then that solution must have symmetry group cocompact in the isometry group of Xn; and we prove (Theorem 1) that the densest packing of unit disks in E2 is unique up to congruence. In Section IV we analyze the symmetries of some densest packings of polygons in the hyperbolic plane. This will suggest a modified form of uniqueness for the solution of a densest packing problem. We now introduce some notation and basic features of density. We will be concerned with “packings” of “bodies” in Xn. By a body we mean a connected compact set in Xn with dense interior and boundary of volume 0. Assume given some finite collection B of bodies in Xn, for instance a single ball. By a packing of bodies we then mean a collection P of bodies, each congruent under the isometry group of Xn to some body in B, such that the interiors of bodies in P do not intersect. Denoting by Br(p) the closed ball in Xn of radius r and center p, we define the “density relative to Br(p)” of a packing P as:
 (1) DBr(p)(P)≡Pβ∈P mXn[β ∩Br(p)] mXn[Br(p)] ,
where mXn is the usual measure onXn.
Then, assuming the limit exists, we define the “density” of P as:
(2) D(P)≡ lim r→∞Pβ∈P mXn[β ∩Br(p)] mXn[Br(p)]
It is not hard to construct packings P for which the limiting den- sity D(P) does not exist, for instance by the adroit choice of arbitrarily large empty regions so that the relative density oscillates with r instead of having a limit. (In hyperbolic space the limit could exist but depend on p, which we also consider unacceptable.) The possible nonexistence of the limit of (2) is an essential feature of analyzing density in spaces of infinite volume; density is inherently a global quantity, and funda- mentally requires a formula somewhat like (2) for its definition [Feje], [FeKu]. We discuss this further below. The most important examples for which we know the densest pack- ings are those for balls of fixed radius in En for n = 2 and 3. (For a recent survey of this problem in higher dimensions see [CoGS]). It will be useful in discussing these problems to make use of the notion of “Voronoi cell”, defined for each body β in a packing P as the closure of the set of those points in Xn closer to β than to any other body in P. A noteworthy feature of the n = 2 example is, then, that in the optimal packing (see Figure 1) the Voronoi cell of every disk (the smallest regular hexagon that could contain the disk) has the prop- erty that the fraction of the area of this cell taken up by the disk is strictly larger than for any other Voronoi cell in any packing by such disks. (Intuitively, the optimal configuration is simultaneously optimal in all local regions.) As for n = 3, it is generally felt that the dens- est lattice packing (i.e., the face centered cubic) achieves the optimum density among all possible packings, along with all the other packings made by layering hexagonally packed planar configurations, such as the hexagonal close packed structure; see [Roge]. There are claims in the literature by Hsiang [Hsia] and by Hales [Hale] for proofs of this, and there is hope that the problem will soon be generally accepted as solved.



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Sistem Produksi Vs Respon Kepada Konsumen



MTS
ATO
MTO
ETO


FS
Indrustri Gula,
Pakaian (Garmen),
Industri Minyak, Pabrik Part-Part Motor

Pabrik Motor, Mobil, Perusahaan Elektronik
Mobil Mewah (Ferarri)



BP
Industri logam Material, Farmasi, Minuman Ringan, Minuman Dalam Kemasan

Smart TV (Samsung)
Smart Phone
(Android)
Industri Karoseri Truck dan Bus




JS


Pabrik mesin-mesin Teknologi Tepat Guna

Furniture , Gerabah, Kerajinan Perak & Emas
Proyek Pembuatan Jembatan. Proyek Kapal Laut, Kapal Selam.


Jenis Sistem :
Jenis Respon :

MTS   : Make To Stock
MTO   : Make To Order
ATO    : Assembly To Order
ETO    : Engineer To Order


FS       : Flow Shop
BP      : Batch Production
JS       : Job Shop

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Sunday, March 31, 2013

Cara Kompres File/Folder Menjadi File RAR Di Ubuntu 12.10 | Linux


RAR merupakan salah satu metode kompresi yang paling banyak digunakan di dunia teknologi. Untuk sebagian besar orang yang menggunakan jendela, ketika kita mengatakan kompres ... untuk kompres dengan RAR. Tidak seperti metode kompresi lainnya, RAR menyediakan satu set fitur yang baik seperti SFX arsip, spliting kompresi menjadi beberapa bagian, metode enkripsi yang baik, kompresi yang ketat, dll

Secara default Ubuntu tidak memungkinkan kita untuk membuat arsip RAR. Tapi, apakah itu berarti mustahil? Tidak sama sekali .... sangat mudah ... mari kita lihat bagaimana membuat arsip RAR di Ubuntu:



  •  First open the terminal ( CTRL+ALT+T) and type sudo apt-get install rar
       
    ( Pertama buka terminal ( CTRL+ALT+T ) dan Ketik sudo apt-get install rar )
  •  Next right-click on what ever you want to compress and click on “Compress”
        ( Selanjutnya klik kanan pada File/Folder yang ingin Anda kompres dan klik pada "Compress" )
  •  Finally select RAR as the file extension (as shown in the image below) and click on create. (if you want split the archive into multiple volumes or if you want to use encryptions click on “Other Options”)
       ( Akhirnya pilih RAR sebagai ekstensi file (seperti yang ditunjukkan pada gambar di bawah) dan klik Create. (jika Anda ingin membagi arsip menjadi beberapa volume atau jika Anda ingin menggunakan enkripsi klik pada "Pilihan Lain")


  • Tutorial Install Dengan Gambar Screenshot: 
    1. CTRL+ALT+T atau Open Terminal , Lalu Ketik >>  sudo apt-get install rar  >> Enter
    2. Kalau diminta memasukkan password, masukin saja password admin login kalian, >> Enter
    3. Otomatis akan Download dan Install, tunggu sampai selesai.
    4. Setelah selesai, tutup terminal, Lalu buka Folder atau File yang ingin kalian kompress jadi rar, zip, 7zip, tar, tar-gz, dll, 
    5. Klik Kanan pada File/ Folder yang akan dibuat Rar, Klik Compress
    6. Ada berbagai ekstensi yang ada di situ, Pilih RAR
    7. Proses Compress akan berlangsung, tunggu sampai Selesai.
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