What is Varkon ?VARKON can be used as a traditional CAD-system with drafting, modelling and visualization if you want to but the real power of VARKON is in parametric modelling and CAD applications development. VARKON includes interactive parametric modelling in 2D or 3D but also the unique MBS programming language integrated in the graphical environment. The system was originally developed by a group lead by Dr. Johan Kjellander at the University of Linkoping in Sweden. In 1985 he founded Microform and Varkon became a commersial product. Varkon was marketed and further developed until year 2000 when Dr. Kjellander left Microform to lead the CAD research group at the University of ?rebro. The sources were then released under the GNU/GPL license and the CAD research group became the maintainers of the system. In august 2007 the Varkon project moved to the SourceForge web. See: http://www.sourceforge.net/projects/varkon where it is still maintained by the members of the CAD research group at the university in ?rebro. VARKON is written in ANSI portable C and has been compiled and successfully executed on many different platforms. The UNIX version has a user interface based on X-Windows/OpenGL and the PC version uses Microsoft WIN32/OpenGL. Prebuilt binaries are available for Linux and Microsoft windows. Some things you can do with VARKON.VARKON is used to develop and run applications. An application is a VARKON system that’s been modified and extended with knowledge and functionality specific to a certain product or problem. VARKON applications can perform any calculations, retrieve data from external databases, make decisions, perform complex geometrical operations, build object oriented structures with attributes and geometry, generate graphic images like 2D drawings or 3D models with shading or hidden lines removed and create any type of datafiles with output of your own choice. VARKON is ideally suited for all types of variational design. Wooden houses, tools for ballbearings, welded steel parts or electrical installations are some of the products currently designed in VARKON using this technique. In variational design the actual design work is often reduced to a few percent of the time spent with traditional methods. Using VARKON with its unique ability to handle geometry as well as other features and store the result in a well structured and object oriented manner it is also easy to produce much more information than paper drawings. Cost estimations, bill of materials and different forms of manufacturing data are usually created automatically in VARKON applications. VARKON is easy to integrate. A VARKON application can communicate using files or pipes and can spawn other processes as well as being spawned itself. Using this technique you can either let a VARKON application be on top and control other systems or you can use other systems to control VARKON. Varkon also includes an ODBC API for communication with commersial databases. VARKON is a powerful geometric modeller. Basic 3D entities are points, lines, arcs, curves, surfaces, coordinate systems and transformations. Several representations of parametric curves are implemented including rational polynomial, analytical offset and curves on surfaces so called UV-curves. Surface representations include rational polynomial, lofted procedural, analytical offset and a faceted surface for approximations. Basic support for trimmed surfaces was introduced in Varkon version 1.19. Operations include intersects, closest point, silhouette, curvatures, transformation, trimming, export, import and approximation. Basic visualization as well as complex rendering based on OpenGL is included in all versions of the system. A key feature in all modeling is the capability to record not only the results of interactive operations but also the operations history, making it possible to go back and inspect what you have done, then change something and automatically update the model. Being a fully generic system this is standard behavior in VARKON. All interactive operations are automatically recorded as MBS-statements and the model can any time be edited using the MBS-editor instead of interactive graphics if this is preferred. Using MBS your own design rules or constraints can easily be linked into the model. Such changes are automatically compiled and the result shown immediately on the screen. Two things you can’t do.VARKON is not a true solid modeller. VARKON surfaces can be trimmed and faceted and images can be produced with shading or hidden lines removed but mass properties like volume or center of gravity can not be calculated automatically. This doesn’t mean you cant use VARKON in applications where weight or volume is important. It only means you will have to deal with the problem in other (maybe less automatic) ways. VARKON is not a manufacturing (CAM) system. There are no high level functions in VARKON to support the programming of multi axis numerical machines. You can create your geometry in VARKON but multi axis machine programming will have to be done using other software. For less complicated manufacturing processes though it can surprisingly often be worth the effort to let VARKON applications generate numerical control data automatically even if this means extra programming in MBS initially.
个人日记
An introduction to Ubuntu
An introduction to Ubuntu:Ubuntu is “Linux for human beings”, a complete open-source operating system which aims to make Linux simple and a solid option for everyday desktop use. It includes common applications such as a web browser, e-mail client, and a complete office suite that is compatible with Microsoft Office and other document formats, such as the new ODF standard, the rapidly growing standardized format for the future of office documents.Ubuntu is available completely free of charge, in keeping with the founding principles of the Ubuntu distribution. Ubuntu’s active, growing community is one of the core aspects of Ubuntu, with users participating in such ways as providing free support for others, exchanging ideas and suggestions, and developing software, all as volunteers.Ubuntu is much more stable and less prone to security holes, viruses, and spyware than Windows due to a different security model, is entirely themable and customizable to fit your needs and preferences, and has huge quantities of software available to go with it, all easily accessible and free. Many of these applications, including the office suite, are even available for Windows, so you can comfortably use the same thing on both systems.You don’t have to give up everything you know and jump in headfirst. Ubuntu’s Live CD lets you run Ubuntu entirely off a CD without touching your existing Microsoft Windows or Mac OS X installation at all, with no risk of losing data or breaking the existing installation. You can even install Ubuntu without erasing your other operating system, in a “dual-boot” configuration which allows you to simply choose which one to use when you start the computer and share files between the two systems.Ubuntu is also available with multiple “graphical environments”, that can each be further customized, since everybody has different tastes for the “look and feel” they’re comfortable with. Disks are available today with one called “Gnome” as well as “KDE”, so you can try either of those, and if you’d like to take a look at others (like XFCE), screenshots of all versions (called Ubuntu, Kubuntu, Xubuntu, and one even specially tailored towards use with children and schools called Edubuntu) are available at http://shots.osdir.com/.These CDs are from the 7.04 (April 2007) release and being given to you to make Ubuntu available to people who might otherwise not have been aware of its existence, or of free software in general. Open-source projects such as Ubuntu develop at a rapid pace, so exciting improvements and new features are always becoming available, so watch for future releases too, with the next one coming up this October.So, feel free to pop the CD in and reboot into the Live environment to check it out. If it doesn’t really appeal to you, or you choose one graphical environment over another, please pass unused CDs on to a friend, relative, or coworker you think might be interested or leave it somewhere, like the break room at work perhaps. If you like what you see, just click the “Install” icon on the desktop and enjoy!The current release supports PC (Intel x86), 64-bit PC (AMD64), PowerPC (Apple iBook and Powerbook, G4 and G5), and Sun UltraSPARC architectures, so if you need a different CD, you can download them [http://www.ubuntu.com/download] or get some shipped for free [https://shipit.ubuntu.com/]. For more info, questions, or help installing Ubuntu, check out http://www.ubuntu.com/ !
Introducing the Hardy Heron
Hi Folks, I am delighted to have the pleasure of announcing the Hardy Heron (Ubuntu 8.04), the next version of Ubuntu that will succeed Gutsy Gibbon (Ubuntu 7.10, due for release in October 2007). Not only will the Ubuntu community continue to do what it does best, produce an easy-to-use, reliable, free software platform, but this release will proudly wear the badge of Long Term Support (LTS) and be supported with security updates for five years on the server and three years on the desktop. We look forward to releasing the Hardy Heron in April 2008. With the opening of each new release cycle of Ubuntu, we have more and more opportunity at our fingertips. Not only are our friends in the upstream world constantly innovating and extending their applications and software, but the Ubuntu community continues to see incredible growth in its diverse range of areas such as packaging, development, documentation, quality assurance, translations, LoCo teams and more. Each new release gives us all an opportunity to shine, irrespective of which bricks in the project we are laying, and this is at the heart of our belief – working together to produce an Operating System that will empower its users and shape the IT industry, putting free software at the corner-stone of our direction. Most people only ever see the end-user view of Ubuntu, running it on their desktops, servers and mobile devices around the world. For these users, Ubuntu provides a simple, convenient means to do what they want to do easily, effectively and without unnecessary complexity. For many of us though, we want to open up the hood and understand how the system works and how to extend and grow it. Thousands of us get out of bed every day, united behind Ubuntu, ready to make a difference, working together to make our vision happen. Importantly, our ethos of collaboration and freedom extends to the development process as well as the end product. As such, the Ubuntu development process is a very open, transparent one, and anyone is welcome to get involved. It works like this: – Everyone is welcome to think of and develop ideas for features that could be present in the Hardy Heron release. These ideas are written as specifications (detailed documents outlining how the idea would work and be implemented). You are welcome to add your specifications to https://blueprints.launchpad.net/ubuntu. – In October 2007, we will hold the Ubuntu Developer Summit in Cambridge, Massachusetts, USA and generate a schedule of sessions to discuss these specifications. The sessions provide a means for interested parties to help scope out the proposed feature and determine methods and plans to implement it. The Ubuntu Developer Summit is a semi-virtual event in which those who cannot attend can dial in with VoIP and use IRC and collaborative editing with Gobby to take part in the summit. Everyone is welcome to participate, everyone is welcome to get involved, and everyone is welcome to help shape the form of the Hardy Heron. Let’s work together to shake things up, make things happen and make the most compelling Ubuntu release yet. Start your engines…
人最多的一次
国庆回来后,我就在想什么时候去爬山呢,去完成自己定下的一周去一次的目标。定一个目标容易,坚持下来太不容易了,就像让你把1+1=2每天在本子算10遍一样简单的事,能坚持一个月也不简单了。昨天T问起我,这周还去不去爬山。我也怕自己坚持不下来,我看到天气预报说周六和周日有雨的,有雨可能就去不了了,昨天下午和晚上又要上课。早上起来看窗户外面,昨天晚上还真下雨了,早上雨停了。上午四节课要上,当然不能去了。抓紧时间联系人,下午去,第一节下课在教室找了几个人,今天大家答应的还比较快,想出去走走。一共五个人,说好中午1点到东门****。中午的时候,除了LFZH因为女朋友过来了要陪,其余四人1点都按时到了东门。四个人:WZHSH、LWY、CHH没有什么说的,出发了。考虑到天气的关系,这周应该去中山陵了。这是人最多的一次了,本来想去紫金山的,考虑到天气的原因,就去了中山陵。老****下走了一次,回来时想换个新线路走走,就走了明孝陵那条路。四个人对那里的路都不太熟悉,就随意走吧,到了明孝陵进去参观了下,以前去过的W、CH说现在这里新装修后没有以前那种感觉了,至于是什么感觉,我以前没有去过,现在也没有想得太明白。在明孝陵参观的时候,L一直提醒我要看那面墙上的字。上去的时候我就专门注意了下,原来是“此山为明太祖安之墓”,呵呵,一个山?因为下起了小雨,我们就没有上那“山”顶,到了城墙我们就下来了,城墙上面也有个像四方城那样的一个方形的“城堡”。就是少了石碑,听说这当初为了显示孝心,把石碑尽量做大,大的不能移动了,所以就没有放上来。呵呵
随便写些
一周没有上QQ空间了,也没有来更新下日志。这一周一直在UBUNTU系统下,没有启动过WINDOWS系统。马化腾设计的这个QQ不仅没有LINUX版的,而且还经常把LINUX自己开发的软件给封掉。只要在UBUNTU下就没有办法上空间,没有办法用QQ语音和视频,不知道责任在谁呢?虽然我用的不是盗版的WINDOWS,但用UBUNTU的舒心,快速已经让我很少去启动WINDOWS了。现在记些自己的事情,写些自己的心情,希望QQ的空间不会像传说中的那样要收费。上周申请了个MSN,一直在MSN上和好友联系。就一个原因,MSN在UBUNTU下用着没有限制。以前听说QQ只是人小时候的一个玩具,大了之后就不会再用了。但现在这个玩具已经发展得让你离不开它,因为和很多朋友的联系都在QQ上面,国内也开发了不少即时通信软件,但没有一个能竞争过QQ的。 我的MSN:[email=yunfan_1982@hotmail.com]yunfan_1982@hotmail.com[/email] 不说了,按自己喜欢的方式去生活吧!
征服之再向紫金行
每周一次的爬山已经进行了三次了,这次是国庆前的最后一次爬山了。 虽然每周都去,但是每周的时间都在变化,周一时和班上几个同学提起爬山,他们还都比较有兴趣,就定在了周四,也就是今天了。 昨天晚上在班的群里发了消息,应声的还不少,可到晚上10点后除了李目,大家纷纷表示了有事不能去。 再去找小唐,小唐身体不舒服也不能去。 难道就两个人,要是两个人的话,可能李目也不会去了。 我是一个人也要去的。 11点回去的时候给永华发信息,永华倒是很爽快,直接问,还是6:30****吗? 呵呵,有三个人就可以组队了。 今天早上三个人在食堂吃完饭,7:10就出发了,路上永华还是像前次那样笑呵呵的,李目可能觉得比较新鲜,也说说笑笑的。 走到富贵山隧道,我有意把速度加快了点儿,要不就回来晚了,到琵琶湖时李目已经发觉了走得有些快了,一直在说爬山是要看风景的。 7:57我们到了紫金山脚下,今天永华特意先了上次我们没有走过的那条路,就是向右走过停车场的那条,走到华泰登山道,一看这次爬山完全都是阶梯了,应该很快,但会累。我们三人上了台阶后,我走前面,永华和李目走后面,我在8:15时到了西马腰,和一帮老人家一起活动了下,等永华他们。8:22他们来了,稍作休息,8:25我们又出发了,这次我们一起边聊边走,也走得悠闲,8:35到了头陀领公园入口处,李目想进去看看。我们三人就商定,李目去看,从公园到山顶,我和永华先上山顶,在山顶会合。8:41时我和永华走到了山顶,这次觉得特别的轻松,没有上次那样累了。 吹着山顶的微风,享有着只有在山里才能感受到的宁静。两个人聊着天,这也是人生的一种乐趣吧。 想到走到琵琶湖时,突然被一阵阵的鸟叫给吸引了,原来是一些老人在遛鸟,这些老人,有四个围在一起打牌的,有三三两两一起看报聊天的。 等了一个多小时后,我们还没有看到李目,就开始有些担心了。永华给李目打电话,一直是无法接通,这让我们更担心了。 电话好不容易在10点的时候打通了,李目说我看到你们了,我就在你们对面的山顶上,和其他游人在聊天呢。这小子,害我们白担心。 10:10分,我们终于能下山了。 下山的路上,李目一直在看那阶梯有多少度,呵呵。到了最陡的地方,他说腿都发软了。 在山上,我原来的助理给我发信息说现在太无聊了,不考研也没有事干,都不知道要干什么。我建议他出去转转,他说陪女朋友出去,那次都在花个500多,经常去也花不起呀。我只能告诉他,在这几年里必须做成一件事,不能一件事都没有做好,想考研还是早考的好。 这次登山也是一次挑战,上次分钟到山顶,师兄说太慢了。这次我和永华商量说看能不能跑上山,在30分钟内到山顶。一看永华还穿的是凉鞋,就说下次吧,下次换双能跑的鞋。
南京的天呀
来南京之前听说了南京的闷,今天终于领教了。本来上次台风之后,天变冷了,觉得南京的夏天该过去了,秋天应该来了。前天听天气预报说,这两天又要下雨了。这两天不在的时候都没有敢把衣服凉在外面。今天下午上完课,走出教室,因为教室有空调,也没有感觉到天气的变化。下课后刚走了一里路,就觉得浑身不舒服,身上直冒汗。我想这些天经常爬山,不会是身体虚了吧。想想也不会呀,每次去紫金山都是一路跑上去的。在外面站了一会儿,衣服都湿完了,好像刚从水里出来一样,头发上,耳朵上都像下雨一样滴着水。这才想起来在西安时朋友们说的南京的天是闷的,比西安能闷十倍,而且说是来了之后才能体会,那种闷是站着都浑身冒汗的。现在终于领教了,今天在外面衣服就一直是湿的。西安现在好凉快呀,凉快的有些冷。国庆回家好好放松一下,享受一下西安秋天的凉爽。今天是中秋,祝大家节日快乐。
想回家了
这些一直在思考着要不要回家,想着刚出来才20天就回去值不值得。一个同学的举动鼓舞了我,让我很快就作出了决定,回家。上午来到火车站,看到买票的队伍特别的长,从南京车站售票窗口一直快排到了玄武湖边,每个队伍都是那么多的人。一来就后悔了,同学给我说的要买票就早些,要不就没有票了,现在也只能望着长长的队伍兴叹了。走到一队后面,和一个人聊了起来,他说来了快两个小时了,就走了不到10米,可能有些夸张,不过看着那么长的队伍也没有了排队的心思。走到军人窗口去一看,人也排到了售票厅门口,真奇怪了,那来的这么多军人呀。过去仔细一看,除了五六个军官,两个士官外,其他的全拿的是学员证。呵呵,这里的学员真幸福呀,黄金周还可以回家呀!再一细看,一个个没有个军样,原来是军校招的地方生呀,这些人还真把自己当军人了,在这里来搞特殊了。不等了,赶快赶到了鼓楼邮局去排队,五个窗口虽然人不多,每队也有30多人吧。还算快,买到了票,不过没有座位。想起去年有次来的时候也没有座位,站着都睡着了,这次还是有些紧张。不过有票总比没有好呀。过几天就回家了,在这里感谢下给我鼓励的朋友们,是你们让我做了最后的决定。最重要的是家里有想着自己的人。
游中山陵
上次跑步去了中山陵,这次也是走马观花似的游了一下。 按照我的设想,我们每周都至少去爬一次山,一周中山陵,一周紫金山。 中山陵早就想去了,这周前期的下雨让我们不得不临时去定时间。昨天中午雨停了,今天早上太阳也出来了,暖洋洋的。 上班后,就开始着手联系人,说好中午一点出发的。 中午吃饭后,几个人陆续发来信息,有一个同学朋友来了,一个电话没有打通,还有要上课的。 到1:30出发的时候,就只有我和小唐两个人去了,这次去没有像上次那样,一气跑上去,主要是考虑到去紫金山时小唐脚上的泡还没有下去。 途中浏览了四方城,美龄宫。 四方城里有一个像龟一样的神兽,龟壳上有一个据说是南京地区最高的碑,上面的字为明朝朱棣所书,主要是写朱元璋的一生,共2746字。小唐在这里还为小方了了下心愿,上次和小方跑步来的时候,小方想摸一下神兽,可是回来时忘记了,这次专门让小唐代着摸了一下。 美龄宫建于1931年,当时耗资36万银元。进去一看门票15元/人,我们就都没有进去了。 到中山陵时已经是14:37了,80元的门票让我们要进去就不得不仔细的玩一下,可小唐想下次去租一张年卡好好玩,租年卡能便宜许多呀,一张卡一天10块钱。我来也只是为了考证一下孙中山先生是不是葬于此。只因为和杨波聊天,他说这里是孙先生的衣冠冢,这次来就专门证实一下。 我进了中山陵,小唐到音乐台去听音乐了。进去之后看到各种肤色,说着不同语言的人都来瞻仰中山先生,想到了中山先生的伟大。 本想跟着其他队伍的导游好好了解一下中山陵,可是他们走得太慢了。没有办法,自己看吧,反正就一个目的。 上了象征着“九五至尊”的95级台阶,就到了祭堂,我也没有数到底是不是95级,怀着无比尊敬的心情进了祭堂。 出了祭堂之后,看了旁边的介绍,证实了孙先生确实是葬于紫铜棺下。 两边的两个华表做为权力的象征是那么的威严,现在好像只有中山陵和天安门有这样的华表。 站在这里,南京市区一览无余。我观察了一下南京的地形,三面环山,西北方刚好有个缺口,冬天的西北风刚好 从这个缺口进来,冷风只有进没有出,难怪南京的冬天是那样的冷。 下午4点10分回到了学校,回来之后天就阴了。今天还不错,赶了个好天气。回来后用凉水冲了下,就去吃饭了,可怎么也不想吃。 从不剩饭的我今天也破了记录了。
笑着迎接朝阳
早上一起床,和朋友们聊天,说起了一个笑话。 有两个做假币的,有一天错误地做出了一张150元的纸币,想着在城里了没有办法用,就到山里去用吧。这两个人到山里之后,看到一个卖糖葫芦的山民,就想了山民10块钱的糖葫芦,把那张150的纸币给了山民。这山民一看是150块,收了起来,算了一下,应该给找140元。两个人一看山民将钱收了起来就在一边偷着乐呢。等到他们拿过山民给找的钱的时候,该他们傻眼了。…………两张70的纸币!!! 呵呵 早上出来太阳挺好的,早饭都不想去吃了,就在外面转了转,晒了会儿太阳。 生活中只总结过去的和教训,而不去计较过去的得失,开开心心地迎接新的一天。