Archive for June, 2009

Atlanta Friendship Seminar

Sunday, June 28th, 2009

Last weekend, our dojo and Peachtree Aikikai hosted a joint seminar with Yamada Sensei instructing. The event was a success with a good turn out from both dojos  and from out of town. The weather was very hot, so the training was slow and difficult. Beyond the importance of the event as a symbol for the improved relationship between the two dojos, the training was significant for me in two ways: learning about my health and seeing new aspects of Yamada Sensei’s technique.

On Friday night, we trained for about 1½hours in extremely hot conditions. For sometime,  I have noticed that my endurance has not been as strong as it once was. I have been teaching more than I train and while I try to train with my students when  I teach, I know that this is not enough to develop better endurance. While I’ve been planning for sometime to increase my training, I know that I have to control my exertions on the mat at seminars. I remember feeling tired during the training, but not unusually for me. After training, I sat to fold my hakama on Peachtree Aikikai’s canvas mat feeling now unusually tired. When I stood up I saw that I left a distinct wet mark on the mat from my sweat. I looked around and saw that noone else had left a similar mark on the mat. I sat down in the very nice lounge area they have outside the changing rooms drinking water and waiting until the sweating stopped before I took my shower. I was talking to friends and was in good spirits, but I noticed that it took at least 30 minutes before I stopped sweating and that my fingers and toes were tingling. All of this felt unusual and a little scary to me. I had been very tired after training before, but it never felt like this. Finally I stopped sweating and went to the seminar dinner at Atkins Park, where we had a very good diner in an upstairs room. I had the rack of lamb which was delicious, but in retrospect the filet might have been a better choice to get enough calories to recover.

The following morning I felt tired, but in normal health. I ate breakfast; again perhaps not enough. I trained through the morning, the day was extremely hot, and again I sweated more than usual afterwards, leaving a large sweat mark on the futon coach while I was recovering. I ate the pizza lunch, but was not very hungery and didn’t finish the second piece. I drank plenty of water. In the afternoon I only made it through one hour at which point I almost fainted while I was stepping off the mat. I sat in the relative cool changing room drinking water and again my fingers and toes were tingling. I tested my circulation by pressing my finger and it looked fine. As before it was a long time before I stopped sweating. I kept thinking that this was wrong; I get tired, but not like this.

It wasn’t until the following Tuesday that I felt normal. On Thursday I went to the doctor, who gave me an EKG and took blood. He didn’t share my concern that my experience was unusual. He said that it was classic heat exhaustion and that I needed to make sure that I ate more and drank more water before training. My EKG came back normal and the blood work report doesn’t come in until Monday. The only thing that gives me pause is that my resting heart rate measured 47bpm, which would be fine if I was a marathon runner, but seems low for someone who is aware of lack of endurance. I have no idea what this could mean, and the doctor seemed unconcerned. My conclusion, until the blood work comes in, is that I need extra work on endurance and have to be more conscious of my caloric intake before training. Today I started running. Later I explain the running program I’m trying.

The classes

As usual, Yamada Sensei focused on basic training. One of his themes, as in many recent seminars, is varying the amount of rotation on tenkan. It occured to me that I had noticed many years ago that his technique was unusual because he didn’t always take the same stance at the end of tenkan. At the time, I thought tenkan was tenkan and I always thought it should be done the same way regardless of the context. More and more I notice the degree of his tenkan, even on old videos. It is easy to get caught up in what one thinks is the right form and not see that the teacher is doing something different.

As always, I am taken by how low Yamada Sensei’s stance is. I have been working on this for some time and it still hard for me to maintain this low stance consistently.

Despite the heat, the general mood of training was serious, but upbeat. Yamada Sensei seemed to enjoy the event and kept the mood light.

SCP without passwords

Wednesday, June 10th, 2009

In embedded development, there is the problem that after you build the code on your host PC, you have to load onto the target. My normal solution for this is to create an NFS mount to a folder on the host that contains the binaries and the necessary auxiliary files. I was motivated to load the files via scp, but I prefer to automate my development cycle as much as possible. This means calling scp from the makefile, which means calling it without a password. I knew it was possible to set up a system that allowed this, so I turned to Google.

I searched for “scp in scripts”. The first link seemed very authoritative and gave instructions that used ssh-keygen to create a public RSA key to put in the host’s ~\.ssh\authorized_keys file. Possibly because the target is using Dropbear for ssh, these instructions didn’t work and I spent a significant amount of time trying to debug the system.

A co-worker that I had dragged into the problem gave me a different solution that did work. When I asked him where he found his solution, he said “Google”. To my frustration, his link was the first link for him on the search “scp without password”. This illustrates the principle that you should always ask Google for exactly what you want.