[BOINC] [物理类] Einstein@Home

vmzy

July 23, 2007
We have released a updated windows application for Einstein@Home. This application will automatically replace the older application and does not require any action from you. The new app should help with cross-platform compatibility and has some other small improvements as well.
大意：
Einstein@Home的windows版计算内核更新。你不用管它，BOINC会自动升级。提升了跨平台的兼容性，并做了一些小的改进。

macwang

已升级！！！！！

Rojer

啥时候能把速度提升一下....

[ 本帖最后由 Rojer 于 2007-7-24 19:34 编辑 ]

macwang

慢慢来吧，急不得。

Julian_Yuen

We are reaching the end of the current analysis run S5R2, and participants might soon experience an increase of the downloads necessary for the remaining workunits to be processed. Users with rather low bandwidth will probably want to suspend the project for some days.

当前S5R2分析即将结束。余下的待处理WU将可能令参与者们很快体会到下载需求的增加。
带宽较低的用户可能会想把本项目暂停一段时间
（这翻译怎么看怎么蹩脚......orz）

Youth

嗯，每回快到阶段结束时，任务包所需数据文件的下载会比平常多得多

Youth

We have started a new analysis run on LIGO S5 data, called S5R3. This uses a new version of the science application - details will be forthcoming in the Science Message Board area. Users who have been beta-testing the latest app versions should now remove their app_info.xml files.

S5R3已经开始。使用了新的计算程序，详细情况将会发布在留言板的science区域。参加过最近的beta程序测试的用户请把app_info.xml移除。

fwjmath

The S5 science run, whose goal was to accumulate one year of triple-coincident data at LIGO design sensitivity, officially ended at 00:00 UTC October 1, 2007. This completes the data-taking stage of a project which was officially begun in 1992 by Kip Thorne, Ron Drever, and Rainer Weiss. LIGO will now undergo two planned upgrades to improve sensitivity. The first of these upgrades (Enhanced LIGO) will be followed by the S6 science run, anticipated for 2009. Einstein@Home is now busy searching the S5 data set. The Einstein@Home S4 postprocessing and analysis are largely complete and under review by the LIGO Scientific Collaboration. We hope to provide updates about these results before the end of this year.

S5 科学运行已经在 2007 年 10 月 1 日 UTC 0:00 结束，此次科学运行的目的是积累一年来的在 LIGO 设计的灵敏度之下的三重同步数据。此次运行完成了一个始于 1992 年的由 Kip Throne, Ron Drever 和 Rainer Weiss 发起的计划的数据采集阶段。LIGO现在将会进行两个计划好的升级来提高灵敏度。其中之一(Enhanced LIGO)完成之后我们就会开始 S6 科学运行，预计 2009 年将完成。Einstein@home 现在正在搜索处理 S5 收集的数据。Einstein@home S4 数据后期处理和分析已经基本完成，正在由 LIGO 科学协作体审查。我们希望在年底之前能够告诉大家这些分析处理的结果。
//Kip Throne果然是强人～～～以前就看过他写的书～～～好象是关于黑洞什么的～～～听说还跟霍金打过赌～～～而且还赢了～～～

Youth

A description of the latest S5R3 search, and the sensitivity improvements that it gives compared with earlier versions of the Einstein@Home search, is described in this message board thread.

关于S5R3的介绍，可以看论坛的这个帖子：
http://einstein.phys.uwm.edu/forum_thread.php?id=6193#75618

Ok, let me try to give you a short summary of the "evolution" of our search strategies used in successive runs. For a slightly more general overview of where we currently stand, there is a poster on E@H [presented at a recent conference on pulsar astronomy], which you might find interesting:

http://www.ligo.caltech.edu/docs/G/G070593-03.pdf

The key step starting with S5R2 was to move part of the "post processing" from our server to the E@H hosts: previous searches performed one (or two) "F-statistic" searches on the host before sending back the results. These searches were performed over a number (between 17 and 60 in different runs) of different time stretches ("stacks"), which we combined using a "coincidence scheme" in the post-processing stage on the server. The amount of data (ie number of candidates) that can be allowed to be sent back from each host to the server is limited, and it turned out that this was the main factor holding back our achievable sensitivity.

The new "Hierarchical" search scheme, used since S5R2, performs F-statistic searches over 84 different stacks, then combines the results by a sophisticated coincidence scheme ("Hough transform") on the host, and only *then* sends back the results to the server. This avoids the data-returning bottleneck of previous runs and substantially increases the expected sensitivity (by about a factor of 6!)

The first Hierarchical search [S5R2], suffered from certain limitations (too technical to go into here ...) in the workunit-design, due to this new code and search scheme. These limitations were overcome in S5R3 by splitting the sky into several patches and having each workunit search only over one patch at a time, instead of the whole sky at once.

The resulting current search is a substantial leap forward for E@H, and promises unprecedented sensitivity to gravitational waves from spinning neutron stars. However, we are already working on future improvements to this scheme, which should allow us to further increase our reach in distance to spinning neutron stars (namely by increasing the range of frequency spin-downs searched over)

Hope this helps clarify a bit of what is going on "behind the scene".
Best,
Reinhard.

S5R2/S5R3将早先各个阶段中后期由项目方自己进行处理的一些计算工作也进行了分布式处理，由此大幅提高了项目的灵敏度，也减少了对服务器的压力，而S5R3主要是解决了S5R2中存在的一些问题。

YsMilan

原帖由 fwjmath 于 2007-10-3 04:20 发表 //Kip Throne果然是强人～～～以前就看过他写的书～～～好象是关于黑洞什么的～～～听说还跟霍金打过赌～～～而且还赢了～～～

记得赌注是一年的《阁楼》...
霍金跟人打赌一般赌注都是黄色杂志

DF3-CQB

....这就是人类....

DF3-CQB

准备E@H上50W...提前庆祝一下.
现在是499522+PENDING 800....

Youth

http://einstein.phys.uwm.edu/for ... p;nowrap=true#75642

At the pan galactic BOINC meeting (I think this was the official title), the status of the data analysis was given as :

S3 data: analysis finished, nothing found, see link on the homepage
S4 data: analysis finished, under internal review
S5 data: post-processing not finished yet

So don't hold your breath, as the most sensitive S5 data isn't yet fully processed.

I can confirm that (apart from the title actually being "3rd Pangalactic BOINC Workshop").

Some things to add:

* The sensitivity of the search is not only limited by the sensitivity of the detectors, but also by that of the search (algorithm, parameters). This is one of the reasons why we changed that algorithm for S5R2 (see Reinhard's post).

搜索的灵敏度不仅取决于探测器，也受搜索的算法及参数所限。

* The sensitivity of a search for continuous gravitational waves (from sources we call pulsars) increases with the "observation time", i.e. the amount of data analyzed. So far we are only analyzing roughly the first half of S5 data (S5 officially ended on 1 Oct 2007). We plan to do a search of the full S5 data for S5R4, but there are still some technical problems to overcome.

对来自脉冲星的连续引力波的搜索的灵敏度随观测时间增加而增加，但因为S5的数据采集在10.1才完成，目前阶段处理的仍只是前半部分的数据，之后的S5R4才是处理所有数据的。

* In S5 the LIGO detectors run at their "design sensitivity", i.e. the highest sensitivity achievable with their design. Still we are not sure that there is a source of gravitational waves near enough that we can actually detect it with the current instruments. Advanced LIGO is designed to extend the distance by a factor of ten (see "Figure 8" on Reinhard's poster).

虽然LIGO的探测器在S5阶段已经达到了设计的灵敏度，但我们仍不能确保能在设备允许的范围内探测到引力波源。未来的Advanced LIGO可以将搜索距离提高10倍。

* There are other possible sources of gravitational waves than gravitational pulsars, requiring other methods to search for their signals in the detector data than the one we use on Einstein@home. The clusters of the LSC (including "Nemo") are usually running other searches, and do help Einstein@home only when they would be idle otherwise.

除了脉冲星，还有其它各类的引力波源，但需要其它的不同于Einstein@Home的方法来进行搜索。LIGO科学协作组的计算集群通常就在进行这些搜索，只在有空的时候才用来跑Einstein@Home。

BM