You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@hama.apache.org by "Edward J. Yoon" <ed...@apache.org> on 2011/12/06 09:02:31 UTC

Hama Yarn module, process flow diagram

Hi all,

Roughly I just draw a process flow diagram of YARN module[1]. Please
feel free to use this for any purpose and update it.

And this is minor issue but I'd like to renaming several classes.
e.g., BSPRunner to BSPTask if I draw correctly.

1. http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx

-- 
Best Regards, Edward J. Yoon
@eddieyoon

Re: Hama Yarn module, process flow diagram

Posted by Thomas Jungblut <th...@googlemail.com>.
I don't think this is a good idea to ambiguate the name.
It is an ApplicationMaster, I know you think that this is too long, but I
guess this follows the convention. If there is one.

2011/12/6 Edward J. Yoon <ed...@apache.org>

> Additionally, what do you think about renaming BSPApplicationMaster to
> BSPMaster?
>
> On Tue, Dec 6, 2011 at 5:14 PM, Thomas Jungblut
> <th...@googlemail.com> wrote:
> > Hey Edward,
> >
> > the links are a bit confusing but in general this is correct.
> > I'd also like to refactor the BSPRunner to a BSPTask, but not just the
> > naming.
> > There are also shared components that would really save time in
> developing.
> >
> > 2011/12/6 Edward J. Yoon <ed...@apache.org>
> >
> >> Hi all,
> >>
> >> Roughly I just draw a process flow diagram of YARN module[1]. Please
> >> feel free to use this for any purpose and update it.
> >>
> >> And this is minor issue but I'd like to renaming several classes.
> >> e.g., BSPRunner to BSPTask if I draw correctly.
> >>
> >> 1.
> http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
> >>
> >> --
> >> Best Regards, Edward J. Yoon
> >> @eddieyoon
> >>
> >
> >
> >
> > --
> > Thomas Jungblut
> > Berlin <th...@gmail.com>
>
>
>
> --
> Best Regards, Edward J. Yoon
> @eddieyoon
>



-- 
Thomas Jungblut
Berlin <th...@gmail.com>

Re: Hama Yarn module, process flow diagram

Posted by "Edward J. Yoon" <ed...@apache.org>.
Additionally, what do you think about renaming BSPApplicationMaster to
BSPMaster?

On Tue, Dec 6, 2011 at 5:14 PM, Thomas Jungblut
<th...@googlemail.com> wrote:
> Hey Edward,
>
> the links are a bit confusing but in general this is correct.
> I'd also like to refactor the BSPRunner to a BSPTask, but not just the
> naming.
> There are also shared components that would really save time in developing.
>
> 2011/12/6 Edward J. Yoon <ed...@apache.org>
>
>> Hi all,
>>
>> Roughly I just draw a process flow diagram of YARN module[1]. Please
>> feel free to use this for any purpose and update it.
>>
>> And this is minor issue but I'd like to renaming several classes.
>> e.g., BSPRunner to BSPTask if I draw correctly.
>>
>> 1. http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
>>
>> --
>> Best Regards, Edward J. Yoon
>> @eddieyoon
>>
>
>
>
> --
> Thomas Jungblut
> Berlin <th...@gmail.com>



-- 
Best Regards, Edward J. Yoon
@eddieyoon

Re: Hama Yarn module, process flow diagram

Posted by Thomas Jungblut <th...@googlemail.com>.
Hey Edward,

the links are a bit confusing but in general this is correct.
I'd also like to refactor the BSPRunner to a BSPTask, but not just the
naming.
There are also shared components that would really save time in developing.

2011/12/6 Edward J. Yoon <ed...@apache.org>

> Hi all,
>
> Roughly I just draw a process flow diagram of YARN module[1]. Please
> feel free to use this for any purpose and update it.
>
> And this is minor issue but I'd like to renaming several classes.
> e.g., BSPRunner to BSPTask if I draw correctly.
>
> 1. http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
>
> --
> Best Regards, Edward J. Yoon
> @eddieyoon
>



-- 
Thomas Jungblut
Berlin <th...@gmail.com>

Re: Hama Yarn module, process flow diagram

Posted by "Edward J. Yoon" <ed...@apache.org>.
will be ^more^ understandable to the reader.

On Wed, Dec 7, 2011 at 3:51 PM, Edward J. Yoon <ed...@apache.org> wrote:
> Simply good.
>
> Here's more explanation about my original diagram:
>
> 1. ApplicationManager of ResourceManager requests a NodeManager to
> launch ApplicationMaster (BSPMaster).
> 2. ApplicationMaster gets the list of NodeManager to launch
> BSPTaskLauncher (GroomServer).
> 3. ....
>
> IMO, BSP Master, BSP Workers, and BSPTask will be understandable.
>
> On Wed, Dec 7, 2011 at 3:21 PM, Thomas Jungblut
> <th...@googlemail.com> wrote:
>> http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf
>>
>> This is the link to the PDF. I'm a bit dizzy in the last time.
>> What do you think Edward?
>>
>> 2011/12/7 ChiaHung Lin <ch...@nuk.edu.tw>
>>
>>>
>>> Thanks for the explain and diagram uploaded. It is quite clear.
>>>
>>> -----Original message-----
>>> From:Thomas Jungblut <th...@googlemail.com>
>>> To:hama-dev@incubator.apache.org
>>> Date:Tue, 6 Dec 2011 19:11:12 +0100
>>> Subject:Re: Hama Yarn module, process flow diagram
>>>
>>> Soo here is the apache.org upload:
>>> http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf<
>>> http://people.apache.org/~tjungblut/Efficient%20Barrier%20Synchronization%20Mechanism.pdf
>>> >
>>> http://people.apache.org/~tjungblut/yarn-hama-diagram.pptx
>>>
>>> Let me explain it though.
>>> The client submits the job to the YARN infrastructure's resource manager.
>>> This will take care to schedule the BSPApplicationMaster container
>>> (actually this is going through the NodeManager as well).
>>> Once the BSPApplicationmaster runs, it will examine the conf, start the RPC
>>> servers needed (zookeeper as well) and then reports back to the
>>> Resourcemanager (actually I missed to put the arrow back to the
>>> resourcemanager, it is currently pointing to the scheduler). However, the
>>> Resourcemanager will then start the required containers through the
>>> NodeManagers once again.
>>> If the BSPRunner runs the real task, it will piggyback heartbeats to the
>>> BSPApplicationMaster. The container which is running is always piggybacking
>>> to the nodemanager as well.
>>>
>>> Sorry for the filehoster upload.
>>>
>>>
>>> 2011/12/6 Thomas Jungblut <th...@googlemail.com>
>>>
>>> > I updated this, sorry I can't upload on apache because I have no key at
>>> > this pc.
>>> >
>>> > http://uploading.com/files/2af323d7/yarn-hama-diagram.pdf/
>>> > http://uploading.com/files/34m35aee/yarn-hama-diagram.pptx/
>>> >
>>> >
>>> > 2011/12/6 ChiaHung Lin <ch...@nuk.edu.tw>
>>> >
>>> >>
>>> >> Do it have pdf or png format? I can't read it because I don't have MS
>>> >> office suite.
>>> >>
>>> >> -----Original message-----
>>> >> From:Edward J. Yoon <ed...@apache.org>
>>> >> To:hama-dev@incubator.apache.org
>>> >> Date:Tue, 6 Dec 2011 17:02:31 +0900
>>> >> Subject:Hama Yarn module, process flow diagram
>>> >>
>>> >> Hi all,
>>> >>
>>> >> Roughly I just draw a process flow diagram of YARN module[1]. Please
>>> >> feel free to use this for any purpose and update it.
>>> >>
>>> >> And this is minor issue but I'd like to renaming several classes.
>>> >> e.g., BSPRunner to BSPTask if I draw correctly.
>>> >>
>>> >> 1.
>>> http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
>>> >>
>>> >> --
>>> >> Best Regards, Edward J. Yoon
>>> >> @eddieyoon
>>> >>
>>> >>
>>> >> --
>>> >> ChiaHung Lin
>>> >> Department of Information Management
>>> >> National University of Kaohsiung
>>> >> Taiwan
>>> >>
>>> >
>>> >
>>> >
>>> > --
>>> > Thomas Jungblut
>>> > Berlin <th...@gmail.com>
>>> >
>>>
>>>
>>>
>>> --
>>> Thomas Jungblut
>>> Berlin <th...@gmail.com>
>>>
>>>
>>> --
>>> ChiaHung Lin
>>> Department of Information Management
>>> National University of Kaohsiung
>>> Taiwan
>>>
>>
>>
>>
>> --
>> Thomas Jungblut
>> Berlin <th...@gmail.com>
>
>
>
> --
> Best Regards, Edward J. Yoon
> @eddieyoon



-- 
Best Regards, Edward J. Yoon
@eddieyoon

Re: Hama Yarn module, process flow diagram

Posted by "Edward J. Yoon" <ed...@apache.org>.
Simply good.

Here's more explanation about my original diagram:

1. ApplicationManager of ResourceManager requests a NodeManager to
launch ApplicationMaster (BSPMaster).
2. ApplicationMaster gets the list of NodeManager to launch
BSPTaskLauncher (GroomServer).
3. ....

IMO, BSP Master, BSP Workers, and BSPTask will be understandable.

On Wed, Dec 7, 2011 at 3:21 PM, Thomas Jungblut
<th...@googlemail.com> wrote:
> http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf
>
> This is the link to the PDF. I'm a bit dizzy in the last time.
> What do you think Edward?
>
> 2011/12/7 ChiaHung Lin <ch...@nuk.edu.tw>
>
>>
>> Thanks for the explain and diagram uploaded. It is quite clear.
>>
>> -----Original message-----
>> From:Thomas Jungblut <th...@googlemail.com>
>> To:hama-dev@incubator.apache.org
>> Date:Tue, 6 Dec 2011 19:11:12 +0100
>> Subject:Re: Hama Yarn module, process flow diagram
>>
>> Soo here is the apache.org upload:
>> http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf<
>> http://people.apache.org/~tjungblut/Efficient%20Barrier%20Synchronization%20Mechanism.pdf
>> >
>> http://people.apache.org/~tjungblut/yarn-hama-diagram.pptx
>>
>> Let me explain it though.
>> The client submits the job to the YARN infrastructure's resource manager.
>> This will take care to schedule the BSPApplicationMaster container
>> (actually this is going through the NodeManager as well).
>> Once the BSPApplicationmaster runs, it will examine the conf, start the RPC
>> servers needed (zookeeper as well) and then reports back to the
>> Resourcemanager (actually I missed to put the arrow back to the
>> resourcemanager, it is currently pointing to the scheduler). However, the
>> Resourcemanager will then start the required containers through the
>> NodeManagers once again.
>> If the BSPRunner runs the real task, it will piggyback heartbeats to the
>> BSPApplicationMaster. The container which is running is always piggybacking
>> to the nodemanager as well.
>>
>> Sorry for the filehoster upload.
>>
>>
>> 2011/12/6 Thomas Jungblut <th...@googlemail.com>
>>
>> > I updated this, sorry I can't upload on apache because I have no key at
>> > this pc.
>> >
>> > http://uploading.com/files/2af323d7/yarn-hama-diagram.pdf/
>> > http://uploading.com/files/34m35aee/yarn-hama-diagram.pptx/
>> >
>> >
>> > 2011/12/6 ChiaHung Lin <ch...@nuk.edu.tw>
>> >
>> >>
>> >> Do it have pdf or png format? I can't read it because I don't have MS
>> >> office suite.
>> >>
>> >> -----Original message-----
>> >> From:Edward J. Yoon <ed...@apache.org>
>> >> To:hama-dev@incubator.apache.org
>> >> Date:Tue, 6 Dec 2011 17:02:31 +0900
>> >> Subject:Hama Yarn module, process flow diagram
>> >>
>> >> Hi all,
>> >>
>> >> Roughly I just draw a process flow diagram of YARN module[1]. Please
>> >> feel free to use this for any purpose and update it.
>> >>
>> >> And this is minor issue but I'd like to renaming several classes.
>> >> e.g., BSPRunner to BSPTask if I draw correctly.
>> >>
>> >> 1.
>> http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
>> >>
>> >> --
>> >> Best Regards, Edward J. Yoon
>> >> @eddieyoon
>> >>
>> >>
>> >> --
>> >> ChiaHung Lin
>> >> Department of Information Management
>> >> National University of Kaohsiung
>> >> Taiwan
>> >>
>> >
>> >
>> >
>> > --
>> > Thomas Jungblut
>> > Berlin <th...@gmail.com>
>> >
>>
>>
>>
>> --
>> Thomas Jungblut
>> Berlin <th...@gmail.com>
>>
>>
>> --
>> ChiaHung Lin
>> Department of Information Management
>> National University of Kaohsiung
>> Taiwan
>>
>
>
>
> --
> Thomas Jungblut
> Berlin <th...@gmail.com>



-- 
Best Regards, Edward J. Yoon
@eddieyoon

Re: Hama Yarn module, process flow diagram

Posted by Thomas Jungblut <th...@googlemail.com>.
http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf

This is the link to the PDF. I'm a bit dizzy in the last time.
What do you think Edward?

2011/12/7 ChiaHung Lin <ch...@nuk.edu.tw>

>
> Thanks for the explain and diagram uploaded. It is quite clear.
>
> -----Original message-----
> From:Thomas Jungblut <th...@googlemail.com>
> To:hama-dev@incubator.apache.org
> Date:Tue, 6 Dec 2011 19:11:12 +0100
> Subject:Re: Hama Yarn module, process flow diagram
>
> Soo here is the apache.org upload:
> http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf<
> http://people.apache.org/~tjungblut/Efficient%20Barrier%20Synchronization%20Mechanism.pdf
> >
> http://people.apache.org/~tjungblut/yarn-hama-diagram.pptx
>
> Let me explain it though.
> The client submits the job to the YARN infrastructure's resource manager.
> This will take care to schedule the BSPApplicationMaster container
> (actually this is going through the NodeManager as well).
> Once the BSPApplicationmaster runs, it will examine the conf, start the RPC
> servers needed (zookeeper as well) and then reports back to the
> Resourcemanager (actually I missed to put the arrow back to the
> resourcemanager, it is currently pointing to the scheduler). However, the
> Resourcemanager will then start the required containers through the
> NodeManagers once again.
> If the BSPRunner runs the real task, it will piggyback heartbeats to the
> BSPApplicationMaster. The container which is running is always piggybacking
> to the nodemanager as well.
>
> Sorry for the filehoster upload.
>
>
> 2011/12/6 Thomas Jungblut <th...@googlemail.com>
>
> > I updated this, sorry I can't upload on apache because I have no key at
> > this pc.
> >
> > http://uploading.com/files/2af323d7/yarn-hama-diagram.pdf/
> > http://uploading.com/files/34m35aee/yarn-hama-diagram.pptx/
> >
> >
> > 2011/12/6 ChiaHung Lin <ch...@nuk.edu.tw>
> >
> >>
> >> Do it have pdf or png format? I can't read it because I don't have MS
> >> office suite.
> >>
> >> -----Original message-----
> >> From:Edward J. Yoon <ed...@apache.org>
> >> To:hama-dev@incubator.apache.org
> >> Date:Tue, 6 Dec 2011 17:02:31 +0900
> >> Subject:Hama Yarn module, process flow diagram
> >>
> >> Hi all,
> >>
> >> Roughly I just draw a process flow diagram of YARN module[1]. Please
> >> feel free to use this for any purpose and update it.
> >>
> >> And this is minor issue but I'd like to renaming several classes.
> >> e.g., BSPRunner to BSPTask if I draw correctly.
> >>
> >> 1.
> http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
> >>
> >> --
> >> Best Regards, Edward J. Yoon
> >> @eddieyoon
> >>
> >>
> >> --
> >> ChiaHung Lin
> >> Department of Information Management
> >> National University of Kaohsiung
> >> Taiwan
> >>
> >
> >
> >
> > --
> > Thomas Jungblut
> > Berlin <th...@gmail.com>
> >
>
>
>
> --
> Thomas Jungblut
> Berlin <th...@gmail.com>
>
>
> --
> ChiaHung Lin
> Department of Information Management
> National University of Kaohsiung
> Taiwan
>



-- 
Thomas Jungblut
Berlin <th...@gmail.com>

Re: Hama Yarn module, process flow diagram

Posted by ChiaHung Lin <ch...@nuk.edu.tw>.
Thanks for the explain and diagram uploaded. It is quite clear. 

-----Original message-----
From:Thomas Jungblut <th...@googlemail.com>
To:hama-dev@incubator.apache.org
Date:Tue, 6 Dec 2011 19:11:12 +0100
Subject:Re: Hama Yarn module, process flow diagram

Soo here is the apache.org upload:
http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf<http://people.apache.org/~tjungblut/Efficient%20Barrier%20Synchronization%20Mechanism.pdf>
http://people.apache.org/~tjungblut/yarn-hama-diagram.pptx

Let me explain it though.
The client submits the job to the YARN infrastructure's resource manager.
This will take care to schedule the BSPApplicationMaster container
(actually this is going through the NodeManager as well).
Once the BSPApplicationmaster runs, it will examine the conf, start the RPC
servers needed (zookeeper as well) and then reports back to the
Resourcemanager (actually I missed to put the arrow back to the
resourcemanager, it is currently pointing to the scheduler). However, the
Resourcemanager will then start the required containers through the
NodeManagers once again.
If the BSPRunner runs the real task, it will piggyback heartbeats to the
BSPApplicationMaster. The container which is running is always piggybacking
to the nodemanager as well.

Sorry for the filehoster upload.


2011/12/6 Thomas Jungblut <th...@googlemail.com>

> I updated this, sorry I can't upload on apache because I have no key at
> this pc.
>
> http://uploading.com/files/2af323d7/yarn-hama-diagram.pdf/
> http://uploading.com/files/34m35aee/yarn-hama-diagram.pptx/
>
>
> 2011/12/6 ChiaHung Lin <ch...@nuk.edu.tw>
>
>>
>> Do it have pdf or png format? I can't read it because I don't have MS
>> office suite.
>>
>> -----Original message-----
>> From:Edward J. Yoon <ed...@apache.org>
>> To:hama-dev@incubator.apache.org
>> Date:Tue, 6 Dec 2011 17:02:31 +0900
>> Subject:Hama Yarn module, process flow diagram
>>
>> Hi all,
>>
>> Roughly I just draw a process flow diagram of YARN module[1]. Please
>> feel free to use this for any purpose and update it.
>>
>> And this is minor issue but I'd like to renaming several classes.
>> e.g., BSPRunner to BSPTask if I draw correctly.
>>
>> 1. http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
>>
>> --
>> Best Regards, Edward J. Yoon
>> @eddieyoon
>>
>>
>> --
>> ChiaHung Lin
>> Department of Information Management
>> National University of Kaohsiung
>> Taiwan
>>
>
>
>
> --
> Thomas Jungblut
> Berlin <th...@gmail.com>
>



-- 
Thomas Jungblut
Berlin <th...@gmail.com>


--
ChiaHung Lin
Department of Information Management
National University of Kaohsiung
Taiwan

Re: Hama Yarn module, process flow diagram

Posted by Thomas Jungblut <th...@googlemail.com>.
Soo here is the apache.org upload:
http://people.apache.org/~tjungblut/yarn-hama-diagram.pdf<http://people.apache.org/~tjungblut/Efficient%20Barrier%20Synchronization%20Mechanism.pdf>
http://people.apache.org/~tjungblut/yarn-hama-diagram.pptx

Let me explain it though.
The client submits the job to the YARN infrastructure's resource manager.
This will take care to schedule the BSPApplicationMaster container
(actually this is going through the NodeManager as well).
Once the BSPApplicationmaster runs, it will examine the conf, start the RPC
servers needed (zookeeper as well) and then reports back to the
Resourcemanager (actually I missed to put the arrow back to the
resourcemanager, it is currently pointing to the scheduler). However, the
Resourcemanager will then start the required containers through the
NodeManagers once again.
If the BSPRunner runs the real task, it will piggyback heartbeats to the
BSPApplicationMaster. The container which is running is always piggybacking
to the nodemanager as well.

Sorry for the filehoster upload.


2011/12/6 Thomas Jungblut <th...@googlemail.com>

> I updated this, sorry I can't upload on apache because I have no key at
> this pc.
>
> http://uploading.com/files/2af323d7/yarn-hama-diagram.pdf/
> http://uploading.com/files/34m35aee/yarn-hama-diagram.pptx/
>
>
> 2011/12/6 ChiaHung Lin <ch...@nuk.edu.tw>
>
>>
>> Do it have pdf or png format? I can't read it because I don't have MS
>> office suite.
>>
>> -----Original message-----
>> From:Edward J. Yoon <ed...@apache.org>
>> To:hama-dev@incubator.apache.org
>> Date:Tue, 6 Dec 2011 17:02:31 +0900
>> Subject:Hama Yarn module, process flow diagram
>>
>> Hi all,
>>
>> Roughly I just draw a process flow diagram of YARN module[1]. Please
>> feel free to use this for any purpose and update it.
>>
>> And this is minor issue but I'd like to renaming several classes.
>> e.g., BSPRunner to BSPTask if I draw correctly.
>>
>> 1. http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
>>
>> --
>> Best Regards, Edward J. Yoon
>> @eddieyoon
>>
>>
>> --
>> ChiaHung Lin
>> Department of Information Management
>> National University of Kaohsiung
>> Taiwan
>>
>
>
>
> --
> Thomas Jungblut
> Berlin <th...@gmail.com>
>



-- 
Thomas Jungblut
Berlin <th...@gmail.com>

Re: Hama Yarn module, process flow diagram

Posted by Thomas Jungblut <th...@googlemail.com>.
I updated this, sorry I can't upload on apache because I have no key at
this pc.

http://uploading.com/files/2af323d7/yarn-hama-diagram.pdf/
http://uploading.com/files/34m35aee/yarn-hama-diagram.pptx/

2011/12/6 ChiaHung Lin <ch...@nuk.edu.tw>

>
> Do it have pdf or png format? I can't read it because I don't have MS
> office suite.
>
> -----Original message-----
> From:Edward J. Yoon <ed...@apache.org>
> To:hama-dev@incubator.apache.org
> Date:Tue, 6 Dec 2011 17:02:31 +0900
> Subject:Hama Yarn module, process flow diagram
>
> Hi all,
>
> Roughly I just draw a process flow diagram of YARN module[1]. Please
> feel free to use this for any purpose and update it.
>
> And this is minor issue but I'd like to renaming several classes.
> e.g., BSPRunner to BSPTask if I draw correctly.
>
> 1. http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx
>
> --
> Best Regards, Edward J. Yoon
> @eddieyoon
>
>
> --
> ChiaHung Lin
> Department of Information Management
> National University of Kaohsiung
> Taiwan
>



-- 
Thomas Jungblut
Berlin <th...@gmail.com>

Re: Hama Yarn module, process flow diagram

Posted by ChiaHung Lin <ch...@nuk.edu.tw>.
Do it have pdf or png format? I can't read it because I don't have MS office suite. 

-----Original message-----
From:Edward J. Yoon <ed...@apache.org>
To:hama-dev@incubator.apache.org
Date:Tue, 6 Dec 2011 17:02:31 +0900
Subject:Hama Yarn module, process flow diagram

Hi all,

Roughly I just draw a process flow diagram of YARN module[1]. Please
feel free to use this for any purpose and update it.

And this is minor issue but I'd like to renaming several classes.
e.g., BSPRunner to BSPTask if I draw correctly.

1. http://people.apache.org/~edwardyoon/documents/yarn-hama-diagram.pptx

-- 
Best Regards, Edward J. Yoon
@eddieyoon


--
ChiaHung Lin
Department of Information Management
National University of Kaohsiung
Taiwan