How the K-mean Cluster work
Step 1. Begin with a decision the value of k = number of clusters
Step 2. Put any initial partition that classifies the data into k clusters. You may assign the training samples randomly, or systematically as the following:
Take the first k training sample as single-element clusters
Assign each of the remaining (N-k) training sample to the cluster with the nearest centroid. After each assignment, recomputed the centroid of the gaining cluster.
Step 3 . Take each sample in sequence and compute its distance from the centroid of each of the clusters. If a sample is not currently in the cluster with the closest centroid, switch this sample to that cluster and update the centroid of the cluster gaining the new sample and the cluster losing the sample.
Step 4 . Repeat step 3 until convergence is achieved, that is until a pass through the training sample causes no new assignments.
The public key infrastructure (PKI) is the foundation and center of network security architecture now, can provide security services including confidentiality, authentication, dig2ital signatures and integrity.
兩種解決方案 Richard just finished building his new house. Now the only thing the house misses is a cute little wooden fence. He had no idea how to make a wooden fence, so he decided to order one. Somehow he got his hands on the ACME Fence Catalogue 2002, the ultimate resource on cute little wooden fences. After reading its preface he already knew, what makes a little wooden fence cute.
A wooden fence consists of N wooden planks, placed vertically in a row next to each other. A fence looks cute if and only if the following conditions are met:
?The planks have different lengths, namely 1, 2, . . . , N plank length units.
?Each plank with two neighbors is either larger than each of its neighbors or smaller than each of them. (Note that this makes the top of the fence alternately rise and fall.)
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IBM PC KEYBOARD INFORMATION FOR SOFTWARE DEVELOPERS
================================================================
Sources:
PORTS.A of Ralf Brown s interrupt list collection
repairfaq.org keyboard FAQ(doesn t appear to exsist)
Linux source code
Test hardware:
New Samsung KB3T001SAXAA 104-key keyboard
Old Maxi 2186035-00-21 101-key keyboard
NO WARRANTY. NO GUARANTEE. I have tried to make this information
accurate. I don t know if I succeeded. Corrections or additional
information would be welcome.
This is a plain-text document. If you use a word-processor to view
it, use a fixed-pitch font (like Courier) so columnar data and
ASCII art lines up properly.
Core JSP
In recent years, a large amount of software development activity has migrated from
the client to the server. The client-centric model, in which a client executes complex
programs to visualize and manipulate data, is no longer considered appropriate for the
majority of enterprise applications. The principal reason is deployment—it is a
significant hassle to deploy client programs onto a large number of desktops, and to
redeploy them whenever the application changes. Instead, applications are redesigned
to use a web browser as a "terminal". The application itself resides on the server,
formatting data for the user as web pages and processing the responses that the user fills into web forms.
Capturing low-level network data can be hard in Java, but it s certainly not impossible
If you want to capture network packets in your Java program, you ll need a little help because no parts of the core Java APIAPI give access to low-level network
This project aim was to build wireless software modem for data communication
between two computers using an acoustic interface in the voice frequency range (20Hz–
20,000Hz). The transmitting antenna is a speaker (frequency response of: 90Hz –
20,000Hz) and the receiving antenna is a microphone (frequency response of: 100Hz –
16,000Hz). The test files used as information files were text files.
This goal was attained both in an incoherent scheme and in a coherent scheme.
Build under Matlab code, our modem uses OFDM (orthogonal frequency division
multiplexing) modulation, synchronization by LMS sequence, channel estimation (no
equalizer) via pilot tones. The symbols are either PSK or ASK for a constellation size of
2 or 4. To optimize the probability of error, these symbols were mapped using Gray
mapping.
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