w****a
发帖数: 155 | 1 最近有个项目要做entity recognition， 大老板要用 expert system 推出的 cogito
， 号称有做semantic network 很牛。 但以前没听过这个软件， 可能是我孤陋寡闻。
不知这里有用过的没有， 有什么评价。 除了这个软件，有哪些商用的或开源的比较好
。 |
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b*****y
发帖数: 26 | 2 Thanks for the help offered and the clarification. I appreciate it !
Yes, splitting large data sets into smaller files based on keys greatly
helps.
In this way, we have keys implicitly implemented (in terms of application
specific semantics)
without using any storage.
It also helps parallelism on a SMP machine or a cluster.
This is exactly what Assailant pointed out (see previous posts).
Assailant also suggested splitting the data set in different ways by
different keys.
Both suggestions are act |
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c**t
发帖数: 2744 | 3 http://support.microsoft.com/kb/316626
SQL Server follows the ANSI/ISO SQL-92 specification (Section 8.2, <
Comparison Predicate>, General rules #3) on how to compare strings with
spaces. The ANSI standard requires padding for the character strings used in
comparisons so that their lengths match before comparing them. The padding
directly affects the semantics of WHERE and HAVING clause predicates and
other Transact-SQL string comparisons. For example, Transact-SQL considers
the strings 'abc' an |
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j***i
发帖数: 40 | 4 Be confident, in some sense SQL is not very user-friendly but it is not
something which the human being cannot understand.
I feel you can start from understanding relational algebra (grab any db
textbook), SQL is nothing but a language interface to realize all these
algebra stuff.
After understanding all these semantics stuff, you just need to practice,
that it.
Cheer up |
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u**d
发帖数: 211 | 5 我的意思是，如果 udf 是用 sql 在 db 内部定义的
udf 完全可以看成一个宏，query compilation 的时候替换掉
整个 query 就是一个 sql
比如 f(x) = x + 1
R JOIN T on R.a = f(T.b)
编译的时候就等价于 R JOIN T on R.a = T.b +１
optimizer 完全没有问题
但是如果 f 是用 .NET 写的 udf，f(T.b) 就是一个 black hole
但是 sql 自己提供的 operators 是有限的
很多 function 都无法实现
没办法，扩展性和效率很多时候都是矛盾的
和 sql server 和 teradata 的人都聊过，udf 都是一个很头疼的问题
udf 的调用效率问题，几乎也是因为 query engine 根本无法把 udf
抽象成 high level operators，所以只能按照 semantics，一遍一遍的调用
cost 很高 |
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l******t
发帖数: 660 | 8 Master Data Management by Derek
Monday, November 12, 2012
9:00 PM - 10:00 PM Eastern Time (Add to Calendar)
Please click here to join this meeting
http://www.anymeeting.com/CINASSUG1
Derek--BI Architect; Working/Living in Minnesota
Over 8 years’ experience in database design, development, and
administration using a wide variety of tools and technologies. Having
focused on Business Intelligence using the SQL Server BI stack (SSAS, SSRS,
SSIS, Power-pivot, Semantic Model and Data Mining). |
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l******t
发帖数: 660 | 9 Master Data Management by Derek
Monday, November 12, 2012
9:00 PM - 10:00 PM Eastern Time (Add to Calendar)
Please click here to join this meeting
http://www.anymeeting.com/CINASSUG1
Derek--BI Architect; Working/Living in Minnesota
Over 8 years’ experience in database design, development, and
administration using a wide variety of tools and technologies. Having
focused on Business Intelligence using the SQL Server BI stack (SSAS, SSRS,
SSIS, Power-pivot, Semantic Model and Data Mining). |
|
l******t
发帖数: 660 | 10 新年好戏连台， 不可错过
Self service BI with Powerpivot by Derek
Thursday, Feb 21, 2013
9:00 PM - 10:00 PM Eastern Time (Add to Calendar)
Please click here to join this meeting
http://www.anymeeting.com/CINASSUG1
Derek--BI Architect;
Over 8 years’ experience in database design, development, and
administration using a wide variety of tools and technologies. Having
focused on Business Intelligence using the SQL Server BI stack (SSAS, SSRS,
SSIS, Power-pivot, Semantic Model and Data Mining). |
|
l******t
发帖数: 660 | 11 新年好戏连台， 不可错过
**************请注意， 时间改动
Self service BI with Powerpivot by Derek
Wed, Feb 27, 2013
9:00 PM - 10:00 PM Eastern Time (Add to Calendar)
Please click here to join this meeting
http://www.anymeeting.com/CINASSUG1
Derek--BI Architect;
Over 8 years’ experience in database design, development, and
administration using a wide variety of tools and technologies. Having
focused on Business Intelligence using the SQL Server BI stack (SSAS, SSRS,
SSIS, Power-pivot, Semantic Model and Data Min... 阅读全帖 |
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D****g
发帖数: 2860 | 13
This has NOTHING to do with type safety. Don't mix up type with semantics.
Delegates are not as useful compared to general lamba abstraction (where
delegates rooted) because they are not treated as values as functional
languages do. That doesn't neccessarily mean they are a bad thing. |
|
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B*****g
发帖数: 34098 | 15 【 以下文字转载自 Database 讨论区 】
发信人: lakewest (lake), 信区: Database
标 题: ***CINAOUG/CINASSUG/PASS全球华人用户群新年讲座精品系列 -
发信站: BBS 未名空间站 (Sun Feb 17 18:26:16 2013, 美东)
新年好戏连台， 不可错过
**************请注意， 时间改动
Self service BI with Powerpivot by Derek
Wed, Feb 27, 2013
9:00 PM - 10:00 PM Eastern Time (Add to Calendar)
Please click here to join this meeting
http://www.anymeeting.com/CINASSUG1
Derek--BI Architect;
Over 8 years’ experience in database design, development, and
administration using a wide variety of... 阅读全帖 |
|
f*****m
发帖数: 416 | 16 10.3.5 304 Not Modified
If the client has performed a conditional GET request and access is allowed,
but the document has not been modified, the server SHOULD respond with this
status code. The 304 response MUST NOT contain a message-body, and thus is
always terminated by the first empty line after the header fields.
再查啥是conditional GET
The semantics of the GET method change to a "conditional GET" if the request
message includes an If-Modified-Since, If-Unmodified-Since, If-Match, If-
None-Match... 阅读全帖 |
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p**o
发帖数: 3409 | 17 Semantic Web的研究现在还处于灌水发paper状态，暂时没有什么成熟可用的系统。 |
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xt
发帖数: 17532 | 18
this is not quite true. We do have different GUI objects having
different semantics. For example, the "Back" "Next" "Cancel" "Finish"
buttons on a wizard. We do it with the same class. The way to do is
to find out the source of the event, and handle it differently.
Of course, it takes a linear time complexity to do this. But it won't
take much time, considering
the number of objects a frame is usualy very small - there is no reason
for a reasonable GUI to get that many objects in a single windo |
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xt
发帖数: 17532 | 19
Yes, there can be data members in interfaces. If the
interface is not
for constant definations only, there should be some methods
or semantic
features. In this case, the data members should be related
to the features
otherwise it does not make sense to put them there.
Considering following example, do you think it makes sense:
public interface MyConstants1 {
public static final int a = 1;
}
public interface MyConstants2 {
public static final int a = 2;
public static final int b = 3; |
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c*****t
发帖数: 1879 | 20 Jesus, the code doesn't even compile with so many syntax errors.
It also contains semantic errors (second parameter of check is
String, not File).
I guess that you'd better post some real code.
99.99999999% of the time, some bugs you claim that is compiler/JVM
bug, it is in fact of your own fault. |
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e***g
发帖数: 158 | 21 well, intuitive to a procedural mind, not an OO-mind:)
first of all, the method implementation may not exist in C,
say if C is interface, or abstract.
should they provide an alternative? that this method is concrete,
please invoke its implementation regardless subclass overriding?
they may have technical difficulty of doing this, like limit of
JVM bytecode specification, some runtime semantics consideration.
or they may simply give you the typical java answer: dude, you
don't know what you want, |
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e***g
发帖数: 158 | 22 it represents a specific version, of the contract of the method,
instead of implementation of the method.
if you can call C's method impl f() on A object, inside which another
virtual method g() is invoked, then what? you want C::g() or A::g()?
which one is the intuitive one?
your requirement fundermentally changes the method dispatching semantics
of the langauge, it will cause endless confusion and problems. |
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c*****t
发帖数: 1879 | 23 I have a question regarding Jelly and other XUL or XAML tools on
error handling. Basically, how they do it.
1. how they handle parse errors. The errors are not syntactic ones
that XML parsers SAX/JDOM detect, but semantic ones like unknown
tags, invalid variables, invalid values, wrong attributes etc.
2. logging.
3. warning/debugging.
I am currently trying to come up a solution to improve CookXml
( cookxml.sourceforge.net )'s error handling, but it would be nice
to know how others doing |
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F****n
发帖数: 3271 | 24 That's a classical Swing question:
1. You should implement your own TreeModel to allow on-demand load of data.
Do not use DefaultTreeModel and DefaultMutableTreeNode
2. The correct semantics of TreeModelEvent is the tricky part. Remember the
purpose of TreeModelListener is for TreeModel to inform JTree, so whenever a
TreeModelEvent is fired, your TreeModel already has new data and JTree
still has the old data. That will help you understand TreeModelEvent.
Basically you should specify the path (O |
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m******t
发帖数: 2416 | 25
That semantical requirement is too strong. As long as the model
validates the weak reference (as any code using weak references should)
before dereferencing it, it's fine. |
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s******e
发帖数: 493 | 26 Actually in java, method local class once compiled will be no different fom
other classes (the semantic scope might be different). To make this happen,
method local class has to keep copy of local variables it refers. But how
compiler does it, I have never seen any books and articles talking about It.
Somebody posted above suggested that compiler uses constructor to do this.
I am not sure if it is correct.
The final variables usually are saved in some run time area(different from
stack and heap)... 阅读全帖 |
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s******e
发帖数: 493 | 27 All classes are "equal" once compiled no matter where you define them (the
semantic scope might be different depending on where you define your classes
). I think java classes are designed following this principle.
without a local copy, how can you make it happen? |
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s******e
发帖数: 493 | 28 First, you should understand that method local class is different from
regular inner class. If not, please google it, and you will know the
difference.
i asked you to compile the example class I posted because you had a trouble
to understand that what I said, "once compiled, the innner and enclosing
classes are independent (of course they are coupled)".
Did you try to create and compile a method local inner class trying to use a
final local variable? if not, please do it. The mechanism will be d... 阅读全帖 |
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r*****l
发帖数: 2859 | 29 I did not question "inner class has to keep a local reference to the
enclosing class variables"
I am questioning "keep copy of local variables", which is also in your post.
Ok, to remind you: "method local class once compiled will be no different fom other classes (the semantic scope might be different)" The other class here also include regular inner class. And you mentioned that method local class needs to keep a "copy of local variable", a variable that does not belong to the inner class. Per... 阅读全帖 |
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z*******3
发帖数: 13709 | 30 看了一遍我笑了
第一，楼主你这个高级黑啊
我都分不清楚你到底是在认同我还是在反对我
当然你有其他的原因，也行，蛮好
世界是多样的，但是你我在结果上的一致就可以了
你重复了我至少三个观点，都只说了原因不同
但是对结果居然均表示赞同
这就够了，我很感谢你，其实完全可以求同存异的
我不想奚落你，但是你的错误还是要改正
哈哈
第二
呢，本着讨论的态度，我点解你一点点
你应该把我以前贴认真看看再说
不要以为只有你知道enum是个class，我早就说过enum是有限个的class
java只有一种结构，就是class，但是我隐约觉得这是白说，估计没几个看懂
这是流行答案
No, you can't do this in Java. Aside from anything else, d would then
presumably be an instance of A (given the normal idea of "extends"), but
users who only knew about A wouldn't know about it - which defeats the poi... 阅读全帖 |
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z*******3
发帖数: 13709 | 31 看了一遍我笑了
第一，楼主你这个高级黑啊
我都分不清楚你到底是在认同我还是在反对我
当然你有其他的原因，也行，蛮好
世界是多样的，但是你我在结果上的一致就可以了
你重复了我至少三个观点，都只说了原因不同
但是对结果居然均表示赞同
这就够了，我很感谢你，其实完全可以求同存异的
我不想奚落你，但是你的错误还是要改正
哈哈
第二
呢，本着讨论的态度，我点解你一点点
你应该把我以前贴认真看看再说
不要以为只有你知道enum是个class，我早就说过enum是有限个的class
java只有一种结构，就是class，但是我隐约觉得这是白说，估计没几个看懂
这是流行答案
No, you can't do this in Java. Aside from anything else, d would then
presumably be an instance of A (given the normal idea of "extends"), but
users who only knew about A wouldn't know about it - which defeats the poi... 阅读全帖 |
|
z*******3
发帖数: 13709 | 32 看了一遍我笑了
第一，楼主你这个高级黑啊
我都分不清楚你到底是在认同我还是在反对我
当然你有其他的原因，也行，蛮好
世界是多样的，但是你我在结果上的一致就可以了
你重复了我至少三个观点，都只说了原因不同
但是对结果居然均表示赞同
这就够了，我很感谢你，其实完全可以求同存异的
我不想奚落你，但是你的错误还是要改正
哈哈
第二
呢，本着讨论的态度，我点解你一点点
你应该把我以前贴认真看看再说
不要以为只有你知道enum是个class，我早就说过enum是有限个的class
java只有一种结构，就是class，但是我隐约觉得这是白说，估计没几个看懂
这是流行答案
No, you can't do this in Java. Aside from anything else, d would then
presumably be an instance of A (given the normal idea of "extends"), but
users who only knew about A wouldn't know about it - which defeats the poi... 阅读全帖 |
|
z*******3
发帖数: 13709 | 33 看了一遍我笑了
第一，楼主你这个高级黑啊
我都分不清楚你到底是在认同我还是在反对我
当然你有其他的原因，也行，蛮好
世界是多样的，但是你我在结果上的一致就可以了
你重复了我至少三个观点，都只说了原因不同
但是对结果居然均表示赞同
这就够了，我很感谢你，其实完全可以求同存异的
我不想奚落你，但是你的错误还是要改正
哈哈
第二
呢，本着讨论的态度，我点解你一点点
你应该把我以前贴认真看看再说
不要以为只有你知道enum是个class，我早就说过enum是有限个的class
java只有一种结构，就是class，但是我隐约觉得这是白说，估计没几个看懂
这是流行答案
No, you can't do this in Java. Aside from anything else, d would then
presumably be an instance of A (given the normal idea of "extends"), but
users who only knew about A wouldn't know about it - which defeats the poi... 阅读全帖 |
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m*****n
发帖数: 204 | 34 Your question is a very good one. It touches on both points of multithreaded
programming:
Synchronization and memory coherency (memory barrier). Had vector been
implemented in java 1.5 or later, it wouldn't make much sense to synchronize
on these two methods. It's enough to declare the relevant vars as volatile.
But pre-1.5 volatile semantics was different, and synchronized was the only
way to add memory barrier. |
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r*****s
发帖数: 985 | 35 车轱辘话我不愿意老讲：
这个proven case is a narrow case。
好的，
我们都来学习一下：
http://en.wikipedia.org/wiki/CAP_theorem
The proof of the CAP theorem by Gilbert and Lynch is a bit narrower than wha
t Brewer had in mind. The theorem sets up a scenario in which a replicated s
ervice is presented with two conflicting requests arriving at distinct locat
ions on a time when a link between them is failed. The obligation to provide
availability despite partitioning failures leads the services to respond; a
t least one of th... 阅读全帖 |
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S*****n
发帖数: 227 | 37 Actually, I think radmin22 ask a good question.
The difference between, malloc/free, new/delete, and new[]/delete[]
lies in the semantic and history of C/C++.
malloc/free and new/delete differs in that, new/delete not only
malloc/free the memory area, but also call the object constructor/destructor.
And in early days of C++, if you new an array of objects, and you need
to delete them in following way.
p = new Object[size];
delete[size] p;
This delete[size] seems easily to be tra |
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P*****f
发帖数: 2272 | 38 I remember the semantics is to return the nth smallest element
Depends on the implementation, many structures are implemented
by array and O(1) for access. |
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c********e
发帖数: 383 | 39 the key that you could have that looks-like recursive definition is the
keyword "static"
it is semantically correct, but as to if the current C++ standards allows
it wait for the response from thrust. |
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d****2
发帖数: 6250 | 40 I think in C++ the compiler can optimize using language semantics. Thus
relying on side-effects of those special functions (ie, change their meaning
) is unpredictable and not a good way to program. |
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d****2
发帖数: 6250 | 41
dtor is object-specific. must check first.
now after free object-specific space, free the space the object itself in
heap (space usage sizeof(object)), that will check NULL pointer there so no
need to check before calling delete.
Basically it is implementation-specific based on delete semantic in C++. |
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r*********r
发帖数: 3195 | 42 a language should not be mixed with its libraries.
when you learn/teach a language, pay attention only to its syntax, semantics
, core data structures, and some basic io stuff.
i see too many mediocre java books lost their way amid awt, regex,
multithreads, jdbc etc. in the end, they tend to do a poor job at teaching
the language itself.
and the java APIs evolve so quickly, it's basically not worth investing the
time to study, unless you have a job to get done at hand. |
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m******t
发帖数: 2416 | 43
semantics
What you said might be true for many other languages, but certainly not for
Java. You can't do shit in Java - literally not even "Hello world" - if you
don't learn about the core packages.
That's because Java's syntax is really very simple - and IMHO that's the
beauty of Java.
(Besides, how do they ever make 1519 pages if they only covered the syntax?)
the
The core APIs haven't changed that much - they have been enriched over the
releases, but many things I learned in the 1.2 days sti |
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r*********r
发帖数: 3195 | 44 java's syntax is quite consistent, but its semantics, object model, and its
runtime/vm are quite complicated. i've seen many stupid java programs, from
which it's obvious that the programmer didn't understand those things very
well.
as for the libraries, a java book should only talk about packages under java
.lang, java.io, and a bit about containers under java.util.
look at the "c programming language", they didn't try to discuss the whole
UNIX API, instead they left the job for richard stevens |
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p***o
发帖数: 1252 | 45
有点。
没看明白，你说啥？是不是这个:
14.1.2
There is no semantic difference between class and typename in
a template parameter. typename followed by an unqualified-id
names a template type parameter. typename followed by a
qualified name denotes the type in a non-type parameter
declaration. A storage class shall not be specified in a
template parameter declaration. |
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