The GRASPeR simulation result is not very satisfying, the model can only explain about 30% of the variance. R2 is also not good. I do not know if this is an acceptable result and have to ask my supervisor.
On the other hand, I think CAPS can use actual map aside from randomly generated map. Thus I am considering turn back to CAPS again. To define habitat types and their suitability I need to find out what are the key variables determining Sphagnum suitability. This involves using cluster analysis and scoring of values. I'll do that tomorrow.
2006年7月31日星期一
2006年7月28日星期五
Peace, Propaganda & The Promised Land - Google Video
Peace, Propaganda & The Promised Land - Google Video
前十几分钟还以为是像 LC2E 那样的阴谋论电影，但整个看下来，觉得还是比较客观的。重要的是它提供了看待巴以冲突的另一个角度。
影片批评了美国媒体，表扬了英国媒体。前一段时间英国一个志愿者在耶路撒冷疑被以军故意枪杀，the Guardian 和 Independent 都做了报道，这事在美国会被压下来么？不好说。媒体从业人员也和我们搞环境的一样，要处理 stakeholder 和 pressure group 的问题。Journalists become part of politics, instead of monitoring it.
前十几分钟还以为是像 LC2E 那样的阴谋论电影，但整个看下来，觉得还是比较客观的。重要的是它提供了看待巴以冲突的另一个角度。
影片批评了美国媒体，表扬了英国媒体。前一段时间英国一个志愿者在耶路撒冷疑被以军故意枪杀，the Guardian 和 Independent 都做了报道，这事在美国会被压下来么？不好说。媒体从业人员也和我们搞环境的一样，要处理 stakeholder 和 pressure group 的问题。Journalists become part of politics, instead of monitoring it.
2006年7月27日星期四
GRASP-R documentation sucks…
I tried to use GRASPeR to predict presence today. The problem encountered is that when I use "Model" operation from the GUI, R (mgcv library) gives error message saying that the number of "knots" exceeds the maximum allowed value. It hints that I can get round this either by increasing maximum knots number using
, or by changing the smoother to other types instead of the default thin plate, using
function in
command. However, I found that with GRASPeR I cannot change these values. It seems that GRASPeR defined these values as default but I cannot find where to modify them.The documentation of GRASPeR gives only usage of GUI and functions provided by it. No troubleshooting section, no file format description, no description of dependency. I am really mad about it.I downloaded the source code of GRASPeR, see if I can get round my problem by modifying the source and recompile. If not, I will have to use some more primitive methods, such as typying command one by one by myself
gam.control
, or by changing the smoother to other types instead of the default thin plate, using
s
function in
gam
command. However, I found that with GRASPeR I cannot change these values. It seems that GRASPeR defined these values as default but I cannot find where to modify them.The documentation of GRASPeR gives only usage of GUI and functions provided by it. No troubleshooting section, no file format description, no description of dependency. I am really mad about it.I downloaded the source code of GRASPeR, see if I can get round my problem by modifying the source and recompile. If not, I will have to use some more primitive methods, such as typying command one by one by myself
2006年7月21日星期五
Two biggest problems solved
My last field trip seems to be a success overall. I have proved the link between signatures, waterhead and Sphagnum presence. Thus I can determine from remote sensing images the locations of Sphagnum patches. Actually I just finished marking those patches on a ArcGIS map today.
Next, I will do the same to the 2003 data so they can be used to validate the model. On the other hand, I need more understanding of the GRASP model and R software package. This will occupy most of my time in the following period.
I heard from one of my group fellows during my undergraduate dissertation that they are going to publish a paper based on my dissertation on a journal. That will be my first published work. Very exciting indeed.
Next, I will do the same to the 2003 data so they can be used to validate the model. On the other hand, I need more understanding of the GRASP model and R software package. This will occupy most of my time in the following period.
I heard from one of my group fellows during my undergraduate dissertation that they are going to publish a paper based on my dissertation on a journal. That will be my first published work. Very exciting indeed.
2006年7月10日星期一
居然又有点感动……江南这家伙
上次在 T 大环境系 BBS 本班的版面上看江南《此间的少年》，有那么点感动，尤其是跟他笔下的“萧峰”对号入座之后。时隔一年（还是两年？）之后，闲来无事看江南的《上海堡垒》，居然又有些感动——我就这么被一个网络写手的两篇YY小说感动了两次，诸位看官尽情地鄙视我吧。
其实从名字就能看出《上海堡垒》是对 Macross 的某种模仿。看完第一节后就更觉得像了。还好江南聪明地没有把主人公设定成飞行员而是设定成技术员，不然众多 Macross 的 fans 肯定直接回去重温动画原作去了。不过这模仿还是挺妙，至少上海的地名揉进小说里都不显得太突兀。
故事情节方面，我尽量避免 spoil，感觉剧情完全为人物的感情服务了，很难说有什么特色，不过今天重看 Macross 大概也难免这样想。有些场面还是很抓人的，我读的时候好像忘记了自己面对的是17寸的 LCD，倒好像真的身临其境了。不过，说起来感动我的——不好意思——还是那让人对号入座的感情啊～
江南的这两部YY小说里都有个男主人公，嗯……，当然还有男主人公求之不得的女角——原谅我不能说女主角，那不符合 YY小说的定义，求之而可得就不是YY小说了——以及男主角最后㒇然回首才在灯火阑珊处发现的那个真正爱她的女角（原谅我还是不能说女主角，跟现实生活一样，那女孩子一开始根本没引起木瓜脑袋的男主角和一心YY的读者的注意……），然后就是男主角仗义又有点吊儿郎当的哥们儿，以及他们不可缺少的热血……这么一想两部小说还真是有点像啊……扯远了。有人8g说两部小说里，王语嫣和路依依都有个同样的发卡。也许这两人都有江南认识的某人的影子，也许我们在这里面都能找到自己和其他一些人的影子……
我就因此在空无一人的学校机房里流下了两行蛇的眼泪……诸位再次无情地鄙视我吧。
其实从名字就能看出《上海堡垒》是对 Macross 的某种模仿。看完第一节后就更觉得像了。还好江南聪明地没有把主人公设定成飞行员而是设定成技术员，不然众多 Macross 的 fans 肯定直接回去重温动画原作去了。不过这模仿还是挺妙，至少上海的地名揉进小说里都不显得太突兀。
故事情节方面，我尽量避免 spoil，感觉剧情完全为人物的感情服务了，很难说有什么特色，不过今天重看 Macross 大概也难免这样想。有些场面还是很抓人的，我读的时候好像忘记了自己面对的是17寸的 LCD，倒好像真的身临其境了。不过，说起来感动我的——不好意思——还是那让人对号入座的感情啊～
江南的这两部YY小说里都有个男主人公，嗯……，当然还有男主人公求之不得的女角——原谅我不能说女主角，那不符合 YY小说的定义，求之而可得就不是YY小说了——以及男主角最后㒇然回首才在灯火阑珊处发现的那个真正爱她的女角（原谅我还是不能说女主角，跟现实生活一样，那女孩子一开始根本没引起木瓜脑袋的男主角和一心YY的读者的注意……），然后就是男主角仗义又有点吊儿郎当的哥们儿，以及他们不可缺少的热血……这么一想两部小说还真是有点像啊……扯远了。有人8g说两部小说里，王语嫣和路依依都有个同样的发卡。也许这两人都有江南认识的某人的影子，也许我们在这里面都能找到自己和其他一些人的影子……
我就因此在空无一人的学校机房里流下了两行蛇的眼泪……诸位再次无情地鄙视我吧。
再次诅咒万恶的 Windoze
周六下午本来风平浪静，正在 chat 的时候突然 qterm 不动了，然后 gtalk 和 msn 相继表示我被踢下了线。等了很久，再试图连接，还是失败。
估计是学校 Information Service 在升级路由，于是等了一夜，第二天却依然如故。纳闷之余翻出一张 Ubuntu 的 LiveCD 试验了一下，居然可以上网，只是连接时断时续。于是重新装了 Debian —— 可惜我的 FreeBSD 才装好没多久，又要格式化了。当天下午重回互联网。
虽然如此，gtalk 隔几分钟就断线，qterm 不时地发呆，在加上从学校机房连自己的机器也是断断续续，总之还是不爽。于是试着 traceroute，没有什么结果。猜想是不是什么人在攻击我的机器，就装了 ethereal 抓包。看了一下掉线前后的记录，发现有两个 MAC 地址，一个 Cisco 的，一个三星的，都在争着说“我是10.3.1.1！”（那是我所在网段的网关）。可怜我还以为三星的那个地址是新的网关，于是用 arp -s 把它指定到 10.3.1.1 上，立即断网没商量，现在想起来真是猪头啊。
重新 arp -s 10.3.1.1 到正确的 MAC 地址上，各种服务立马正常了。那个三星的网卡这两天一直在不停地发欺骗数据包，它的地址也通过 arp 得到了，原来离我不远，想必是某人的三星笔记本感染病毒了……都是 Windows 惹的祸，还让我把 FreeBSD 格式化了……不过似乎 FreeBSD 接收假的 ARP 数据包后就认准它就是网关，真网关的 ARP 它也不认了，所以当时在 FreeBSD 下我也没法通过 ethereal 抓包，这重装系统浪费的时间只好当交学费了。
估计是学校 Information Service 在升级路由，于是等了一夜，第二天却依然如故。纳闷之余翻出一张 Ubuntu 的 LiveCD 试验了一下，居然可以上网，只是连接时断时续。于是重新装了 Debian —— 可惜我的 FreeBSD 才装好没多久，又要格式化了。当天下午重回互联网。
虽然如此，gtalk 隔几分钟就断线，qterm 不时地发呆，在加上从学校机房连自己的机器也是断断续续，总之还是不爽。于是试着 traceroute，没有什么结果。猜想是不是什么人在攻击我的机器，就装了 ethereal 抓包。看了一下掉线前后的记录，发现有两个 MAC 地址，一个 Cisco 的，一个三星的，都在争着说“我是10.3.1.1！”（那是我所在网段的网关）。可怜我还以为三星的那个地址是新的网关，于是用 arp -s 把它指定到 10.3.1.1 上，立即断网没商量，现在想起来真是猪头啊。
重新 arp -s 10.3.1.1 到正确的 MAC 地址上，各种服务立马正常了。那个三星的网卡这两天一直在不停地发欺骗数据包，它的地址也通过 arp 得到了，原来离我不远，想必是某人的三星笔记本感染病毒了……都是 Windows 惹的祸，还让我把 FreeBSD 格式化了……不过似乎 FreeBSD 接收假的 ARP 数据包后就认准它就是网关，真网关的 ARP 它也不认了，所以当时在 FreeBSD 下我也没法通过 ethereal 抓包，这重装系统浪费的时间只好当交学费了。
Nerdy 分数上涨……
我够无聊，其实只是为了证明自己比某斯伦贝谢现场工程师更 nerdy：
Overall, you scored as follows:
6% scored higher (more nerdy), and
94% scored lower (less nerdy).
What does this mean? Your nerdiness is:
Supreme Nerd. Apply for a professorship at MIT now!!!.
| For your nerdy work, |
2006年7月7日星期五
A direction determined
After I transformed the waterhead drawdown graph, the classification result and the locations of known Sphagnum to ArcGIS raster format and combined them in one map, I am glad to find that there *is* good agreement between waterhead drawdown, vegetation type and Sphagnum distribution. Most Sphagnum patches are located in cells defined as "not dry". However, I cannot tell what is the exact line between "dry" and "not dry".
The absence of Sphagnum gives poorer result, I guess this is because I did not find some patches in the areas, but Sphagnum can in fact establish in some of them.
Next, I need to find out the width of Sphagnum habitat in terms of hydrology conditions. Then I can do remote sensing prediction for data of both 2003 and 2005, then determine the trend and the usability of GRASP model.
The absence of Sphagnum gives poorer result, I guess this is because I did not find some patches in the areas, but Sphagnum can in fact establish in some of them.
Next, I need to find out the width of Sphagnum habitat in terms of hydrology conditions. Then I can do remote sensing prediction for data of both 2003 and 2005, then determine the trend and the usability of GRASP model.
2006年7月5日星期三
Interesting and encouraging result
Yesterday I decided to simplify the hydrology model which is used to determine habitat suitability, because I noticed that water table changes in and below the 3rd layer are meaningless in the model. Thus I made a new one similar to the original one but with only 3 layers. The 1st layer defined as peat layer and is unconfined; the 2nd defined as mineral soil, confined/unconfined with variable transmissivity; the 3rd defined as a receiver of water.
A simulation of 7 days shows that new model has less discrepancy than the old one. After I extended the simulated time to 900 days the discrepancy is even smaller, maybe due to more stable storage of water. The waterhead drawdown shows that most Sphagnum patches I found in field survey have smaller drawdown (< 1m). This result is useful because it can help improve remote sensing classification.
A simulation of 7 days shows that new model has less discrepancy than the old one. After I extended the simulated time to 900 days the discrepancy is even smaller, maybe due to more stable storage of water. The waterhead drawdown shows that most Sphagnum patches I found in field survey have smaller drawdown (< 1m). This result is useful because it can help improve remote sensing classification.
2006年7月3日星期一
Plan changed a lot
The field trip shows that the distribution of Sphagnum may be related to multiple varibles, or factors, including vegetation, waterhead drawdown and possibly elevation. If there is a river nearby, it is very possible for a point with suitable vegetation to have Sphagnum presence. But a general rule of prediction cannot be deducted from these information so far.
However, I think now I have enough presence data to get a better classification of images, which can serve as initial condition and comparison reference. On the other hand, the MODFLOW model can be improved using thinner peat layer. Then the vegetation, hydrology and elevation data can be input into GRASP to get predictions.
However, I think now I have enough presence data to get a better classification of images, which can serve as initial condition and comparison reference. On the other hand, the MODFLOW model can be improved using thinner peat layer. Then the vegetation, hydrology and elevation data can be input into GRASP to get predictions.
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