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Jeffery yuan
Works at Sony
Attended Tongji University
Lives in New Jersey
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Jeffery yuan

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The Eight Fallacies of Distributed Computing
The network is reliable.
Latency is zero.
Bandwidth is infinite.
The network is secure.
Topology doesn't change.
There is one administrator.
Transport cost is zero.
The network is homogeneous.
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A blind Google engineer explains how he writes code
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How about Java8 on Android on Google/IO?
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Hashmap change in Java 8: Using binary search tree when greater than TREEIFY_THRESHOLD
The principal idea is that once the number of items in a hash bucket grows beyond a certain threshold(currently: TREEIFY_THRESHOLD = 8), that bucket will switch from using a linked list of entries to a balanced tree. In the case of high hash collisions, this will improve worst-case performance from O(n) to O(log n).
If hashes are equal, HashMap hopes that the keys are Comparable, so that it can establish some order.

a shared underlying storage
Shared empty table in ArrayList and HashMap update

static final Object[] EMPTY_ELEMENTDATA = {};
Author, Mike Duigou. Owner, Brent Christian. Created, 2013/02/08 20:00. Updated, 2014/07/10 20:15. Type, Feature. Status, Completed. Component, core-libs. Scope, Implementation. Discussion, core dash libs dash dev at openjdk dot java dot net ...
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XML External Entity (XXE) Processing. From OWASP. Jump to: navigation, search. This is a Vulnerability. To view all vulnerabilities, please see the Vulnerability Category page. Last revision (mm/dd/yy): 03/10/2015. Vulnerabilities Table of Contents ...
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Slate: Gorgeous, Algorithmically Generated Time-Lapses of the World's Most Popular Landmarks.
Time-lapse photography is fascinating because it can reveal changes that transpire too gradually to observe in real time.  The problem is that, well, it takes a long time. Researchers from Google and the University of Washington have found an elegant way around that, at least for some of the world’s...
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Lucene/Solr Search Similarity
tf(t in d) correlates to the term's frequency, defined as the number of times term t appears in the currently scored document d. Documents that have more occurrences of a given term receive a higher score. 

idf(t) stands for Inverse Document Frequency. This value correlates to the inverse of docFreq (the number of documents in which the term t appears). This means rarer terms give higher contribution to the total score
Math.log(numDocs/(double)(docFreq+1)) + 1.0

Query Coordination
coord(q,d) is a score factor based on how many of the query terms are found in the specified document. Typically, a document that contains more of the query's terms will receive a higher score than another document with fewer query terms. - computed at search time
overlap / (float)maxOverlap

The coordination factor (coord) is used to reward documents that contain a higher percentage of the query terms. The more query terms that appear in the document, the greater the chances that the document is a good match for the query.

queryNorm(q) is a normalizing factor used to make scores between queries comparable. This factor does not affect document ranking (since all ranked documents are multiplied by the same factor), but rather just attempts to make scores from different queries (or even different indexes) comparable.
1.0 / Math.sqrt(sumOfSquaredWeights)
The sumOfSquaredWeights is calculated by adding together the IDF of each term in the query, squared.

t.getBoost() is a search time boost of term t in the query q as specified in the query text

Index-Time Field-Level Boosting
We strongly recommend against using field-level index-time boosts

norm(t,d) encapsulates a few (indexing time) boost and length factors:
Field boost - set by calling field.setBoost() before adding the field to a document.
lengthNorm(Field-length norm)- computed when the document is added to the index in accordance with the number of tokens of this field in the document, so that shorter fields contribute more to the score. LengthNorm is computed by the Similarity class in effect at indexing.

DefaultSimilarity extends TFIDFSimilarity
Boolean Model
Vector Space Model
Implementation of Similarity with the Vector Space Model. Expert: Scoring API. TFIDFSimilarity defines the components of Lucene scoring. Overriding computation of these components is a convenient way to alter Lucene scoring. Suggested reading: Introduction To Information Retrieval, Chapter 6.
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7 Mistakes You’re Making In Your Programming Career
1. Not having a clear goal

2. Not investing in non-technical or “soft skills”
people skills, mental stability, focus and self-motivation
how to prioritize and how to be as productive as possible
health and fitness, financial acumen

3. Not being part of the community
Being part of something larger than yourself, is a sure way to grow.

4. Not specializing
5. Not investing in your personal brand
6. Not working on a side-project

7. Not having a plan for self-education or continuous self-improvement.
One of the most popular software development blogs with original content focused on helping developers become better by breaking apart the complex part of software development and making them simple.
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Confused about EdgeRank? Learn about Facebook's famous newsfeed algorithm, including several advanced tips to reach more fans.
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CNET: LG Display shows off press-on 'wallpaper' TV under 1mm thick.
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The Twelve-Factor App
VI. Processes
stateless and share-nothing
Sticky sessions are a violation of twelve-factor and should never be used or relied upon. Session state data is a good candidate for a datastore that offers time-expiration, such as Memcached or Redis.

VII. Port binding
VIII. Concurrency

IX. Disposability
The twelve-factor app’s processes are disposable, meaning they can be started or stopped at a moment’s notice. 
all jobs are reentrant, which typically is achieved by wrapping the results in a transaction, or making the operation idempotent.

X. Dev/prod parity
XI. Logs: Logplex and Fluent, Splunk
XII. Admin processes
A methodology for building modern, scalable, maintainable software-as-a-service apps.
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A mother has been arrested in Georgia for her son's 3 unexcused absences from school. This is what public education looks like in a police state.
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Software Engineer
Java, Linux, Web Development(Jquery, Bootstrap, Javascript, CSS), Solr/Lucene/Nutch, Hadoop, Python, C#, Shell(Bash and bat), Google App Engine, Android, Eclipse(RCP, Plugin Development), Database(MySQL)
  • Sony
    Senior Software Engineer, 2015 - present
    Bug Data: Spark/Cassandra/Lucene/Solr
  • CommVault Systems
    Senior Software Engineer, 2012 - 2015
    Using/Extending Solr/Lucene for enterprise search. Using/Extending Nutch2/Solr for website crawle and search.
  • EMC Corporation
    Senior Software Engineer, 2011 - 2012
    Java Web Services and CMS
  • IBM
    Software Engineer, 2008 - 2011
    Storage, J2SE, Python
Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
New Jersey
Senior Developer, Tech passionate, Geek, Dreamer, I am nobody famous nor rich, just like coding and yearn for freedom
I am interested in Linux, Java, Solr, Search, Algorithm, am contributing to 
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I consider myself well versed in these skills: Java, Web development, Linux, MySQL, interested in algorithm, high-level design.
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  • Tongji University
    Software Engineering, 2005 - 2008
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Jeffery yuan's +1's are the things they like, agree with, or want to recommend.
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Circloscope is the most powerful way to manage your Google+ Circles! (Not affiliated with Google)

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