Papyrus 83: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>Leszek Jańczuk
en>Trappist the monk
m Fix CS1 deprecated coauthor parameter errors; using AWB
 
Line 1: Line 1:
{{Cleanup|date=February 2010}}
Is your business frequently losing out to competitors?<br><br>
In [[multilinear algebra]], there does not exist a general decomposition method for multi-way arrays (also known as ''N-arrays'', ''higher-order arrays'', or ''data-tensors'') with all the properties of a matrix [[singular value decomposition]] (SVD).  A matrix SVD simultaneously computes


:(a) a rank-''R'' decomposition and
Does your slice of the marketing pie seem to be growing smaller each year? You probably need to think about how you can automate and optimize your business practices.<br>The word "automation" frequently brings to mind robots replacing humans in a factory setting. So unless your business is turning out thousands of widgets on a daily basis, you may believe that the topic of automation doesn't pertain to you. You're wrong about that.<br>When you consider automation, expand your thinking to include any use of the latest technologies that would make your business more efficient. Automation can increase productivity, reduce labor costs, reduce payroll overhead by using fewer staff or replacing expensive specialized positions with lower cost positions.<br><br>Automation can also ensure quality, consistency, and predictability through using standardized processes.<br>Companies that fail to streamline and automate usually can't grow or survive when competition appears and drives down prices and reduces profit margins. They find themselves in trouble when the market turns sour and their profits fall while their costs remain high.<br><br>Before this happens to your company, take a good hard look at your business practices from start to finish. Make a list of all the products or services you provide. List and describe your customers. Do you have agreements with [http://tinyurl.com/nqbkz6z cheap ugg boots] other organizations that provide components for your business?<br><br>How do your customers and partners find you? How do you communicate with them? What do they want and expect from you? How do you manage your inventory? How do you advertise to your existing customers, and how do you market to potential clients? How do you manage your financials?<br><br>Be as analytical as possible. What methods do you use to create your products or develop your services? How do your products or services compare to your competitors? How do your business practices compare to theirs? Is your organization less efficient in its interactions with the marketplace?<br><br>Are you running to the store every time  [http://tinyurl.com/nqbkz6z discount ugg boots] you run out of a single item?<br>Don't forget to analyze everything that goes on inside your business, too. For example, how do your executives and employees communicate on a daily basis? How do you measure productivity and track sales? How do you account for all your income and expenses?<br>If you are not familiar with every aspect of your business, you may want to interview other employees to gather information about existing problems and solicit their suggestions  [http://tinyurl.com/nqbkz6z cheap ugg boots] on how processes might be improved.<br><br>After you have a thorough understanding of all the current processes within your organization, you have a lot of areas to consider about how you might modernize. Can you take advantage of a new technology to make a process faster or more efficient? For example, many field workers now file daily reports on handheld devices such as smart phones or tablet computers that they carry with them from job to job.<br>This eliminates the need for those employees to travel from field to office to complete their work, as well as giving the office staff and executives an up-to-date summary of all the work accomplished each day.<br><br>With linked hi-tech networks, many computerized devices can deliver their own reports at regular intervals, as well as sound the alarm when there's a breakdown, send messages to human minders that parts or supplies need to be replaced, and so forth. This is much more efficient than employing someone to run around and constantly check gauges and supplies.<br><br>Consider moving some practices out of the office and putting them online. A good, thorough website can answer many questions and reduce the number of phone calls that an employee needs to handle. Developing an online catalog with detailed descriptions of products and services might win you many new customers.<br><br>An automated online ordering and tracking system could save your organization a lot of money in personnel costs, and can help you efficiently fill orders. Even using simple barcodes and scanners can highlight buying and shipping patterns you might not have noticed, and make inventory control and tracking easy.<br><br>Be sure to look at every process within your business. You may find you need to invest in a new computer system linked to smart devices like phones or tablets. You might want to develop more streamlined internal forms that feed information directly into a central database, which in turn automatically produces [http://Www.Dailymail.Co.uk/home/search.html?sel=site&searchPhrase=reports reports] for the departments that need them.<br><br>You can also streamline personal habits such as shopping online and having supplies delivered instead of leaving the office, driving to stores and disrupting your workday.<br>You may need to outsource certain tasks that are not cost-efficient to automate within your company, or take advantage of new specialized technologies like 3-D printing. These days you can even automate advertising on the internet through online scheduling and targeting programs.<br><br>When you have developed a roadmap of how you might optimize your practices to position [http://tinyurl.com/nqbkz6z uggs on sale] your business for the future, you should write a proposal or a feasibility study to describe your ideas to others in your organization. If you are not the head of the company, this could get you a promotion for being forward thinking.<br><br>If you are writing an internal company proposal, you'll want to explain what changes the organization should make and why, how much these changes will cost, and how these changes will benefit the company. Be as specific as possible, and include all the facts and figures you have accumulated.<br><br>If you are writing a feasibility study, you may want to compare various options ([http://data.Gov.uk/data/search?q=including including] the option of not making any changes), present all the benefits [http://tinyurl.com/nqbkz6z discount ugg boots] and costs of each, and then leave the final decision up to others.<br><br>Just like every other process you have analyzed, you should consider how to optimize the task of creating business documents like proposals, studies, and reports. It is inefficient to start from scratch when there are already packages like proposal and report writing kits available.<br>These kits includes thousands of templates with examples and instructions on each page, as well as sample proposals, studies, and reports you can page through to get ideas. And kits with wizard software that helps you easily assemble any sort of proposal or report.<br><br>Ready-made kits are an excellent choice that can help anyone produce a professional document efficiently.
 
:(b) the orthonormal row/column matrices.
 
These two properties can be captured separately by two different decompositions for multi-way [[matrix (mathematics)|arrays]].
 
Property (a) is extended to higher order by a class of closely related constructions known collectively as [[CP decomposition]] (named after the two most popular and general variants, CANDECOMP and PARAFAC). Such decompositions represent a tensor as the sum of the n-fold outer products of rank-1 tensors, where n is the dimension of the tensor indices. 
 
Property (b) is extended to higher order by a class of methods known variably as ''[[Tucker decomposition|Tucker3]]'', ''N-mode SVD'', and ''N-mode [[principal component analysis]]'' (PCA).  (This article will use the general term "Tucker decomposition".)  These methods compute the othonormal spaces associated with the different axes (or modes) of a tensor.  The Tucker decomposition is also used in [[multilinear subspace learning]] as [[multilinear principal component analysis]]. This terminology was coined by P. Kroonenberg in the 1980s, but it was later called ''multilinear SVD'' and ''[[HOSVD]]'' (higher-order SVD) by L. De Lathauwer.
 
Historically, much of the interest in higher-order SVDs was driven by the need to analyze empirical data, especial in [[psychometrics]] and [[chemometrics]].   As such, many of the methods have been independently invented several times, often with subtle variations, leading to a confusing literature. Abstract and general mathematical theorems are rare (though see Kruskal<ref>Kruskal, J. B. (1989). "Rank, decomposition, and uniqueness for 3-way and N-way arrays". In R. Coppi & S. Bolasco (Eds.), ''Multiway data analysis'' (pp. 7–18). Amsterdam: Elsevier[ [http://publish.uwo.ca/~harshman/jbkrank.pdf PDF] ].</ref> with regard to the CP decomposition); instead, the methods are often designed for analyzing specific data types.  The 2008 review article by Kolda and Bader<ref>{{cite journal | first1 = Tamara G. | last1 = Kolda | first2 = Brett W. | last2 = Bader | url = http://epubs.siam.org/sirev/resource/1/siread/v51/i3/p455_s1 | title = Tensor Decompositions and Applications | journal = SIAM Rev. | volume = 51 | pages = 455–500 (46 pages) | id = {{citeseerx|10.1.1.153.2059}} | doi=10.1137/07070111X}}</ref> provides a compact summary of the history of these decompositions, and many references for further reading.
 
The concept of HOSVD was carried over to functions by Baranyi and Yam  via the [[TP model transformation]] <ref name=Baranyi04>{{cite journal
|author =      P. Baranyi
|title =        TP model transformation as a way to LMI based controller design
|journal =      IEEE Transaction on Industrial Electronics
|year =        2004
|volume =      51
|number =      2
|month =        April
|pages =        387&ndash;400
}}</ref>
.<ref name=compind>{{cite journal
|author =      P. Baranyi and D. Tikk and Y. Yam and R. J. Patton
|title =        From Differential Equations to PDC Controller Design via Numerical Transformation
|journal =      Computers in Industry, Elsevier Science
|year =        2003
|volume =      51
|pages =        281&ndash;297
}}</ref> This extension led to the definition of the HOSVD based canonical form of tensor product functions and Linear Parameter Varying system models <ref name=canon1>{{cite book
|author =      P. Baranyi and L. Szeidl and P. Várlaki and Y. Yam
|title =        Definition of the HOSVD-based canonical form of polytopic dynamic models
|booktitle =    3rd International Conference on Mechatronics (ICM 2006)
|year =        2006
|pages =        660–665
|location =      Budapest, Hungary
|month =        July 3–5
}}</ref> and to convex hull manipulation based control optimization theory, see [[TP model transformation in control theories]].
 
== CP decomposition ==
{{Main|CP decomposition}}
 
===Definition===
A CP decomposition of an N-way array ''X'', with elements <math>x_{i_1 \cdots i_N}</math>, is
 
:<math>X = \sum_{r=1}^{R} D^{(r)} = \sum_{r=1}^{R} a^{(r)} \otimes \cdots \otimes z^{(r)}</math>
 
where <math>\otimes</math> denotes the [[tensor product]]. The ''R'' tensors <math>D^{(r)}</math> (known as ''simple tensors'', ''rank-1 tensors'', ''dyads'', or, in [[quantum mechanics]], ''product states'') are constructed from the ''rN'' vectors <math>a^{(r)}, \cdots, z^{(r)}</math>. With indices, this is
 
:<math>x_{i_1 \cdots i_N} = \sum_{r=1}^{R} a^{(r)}_{i_1} \cdots z^{(r)}_{i_N}</math>
 
where <math>a^{(r)}_{i}</math> is the ''i''-th element of the vector <math>a^{(r)}</math>, etc.
 
== Tucker decomposition ==
{{Main|Tucker decomposition}}
 
=== History ===
In 1966, [[L. Tucker]] proposed a decomposition method for three-way arrays (referred to as a 3-mode "[[tensor]]s") as a multidimensional extension of [[factor analysis]].<ref>{{Cite journal
| author = [[Ledyard R. Tucker]]
| title = Some mathematical notes on three-mode factor analysis
| journal = [[Psychometrika]]
| volume = 31
| issue = 3
|date=September 1966
| doi = 10.1007/BF02289464
| pages = 279–311
}}</ref> This decomposition was further developed in the 1980s by P. Kroonenberg, who coined the terms Tucker3, Tucker3ALS (an alternating least squares dimensionality reduction algorithm), 3-Mode SVD, and 3-Mode PCA.<ref>{{Cite journal
| author = P. M. Kroonenberg
| title = Three-mode principal component analysis: Theory and applications
| journal = DSWO Press, Leiden
| year = 1983
| url = http://three-mode.leidenuniv.nl/bibliogr/kroonenbergpm_thesis/index.html
}}</ref> In the intervening years, several authors developed the decomposition for ''N''-way arrays.
Most recently, this work was treated in an elegant fashion and introduced to the SIAM community by L. De Lathauwer et al. who referred to the decomposition as an ''N''-way SVD, multilinear SVD and HOSVD.<ref name="Lieven De Lathauwer, Bart De Moor and Joos Vandewalle 2000">{{Cite journal
| author = Lieven De Lathauwer, Bart De Moor and Joos Vandewalle
| title = A multilinear Singular Value Decomposition
| journal = [[Society for Industrial and Applied Mathematics|SIAM]]
| volume = 21
| issue = 4
|date=April 2000
| url = http://perso-etis.ensea.fr/~lathauwer/ldl-94-31.pdf
}}</ref>
 
=== Definitions ===
Let the SVD of a real matrix be <math>A = U S V^T</math>, then it can be written in an elementwise form as
 
:<math>a_{i_1,i_2} = \sum_{j_1} \sum_{j_2} s_{j_1,j_2} u_{i_1,j_1} v_{i_2,j_2}.</math>
 
<math>U</math> and <math>V</math> give, in a certain sense optimal, orthonormal basis for the column and row space, <math>S</math> is diagonal with decreasing elements.
''N''-mode SVD can be defined by the multidimensional generalization of this concept:
 
:<math>a_{i_1,i_2,\dots,i_N} = \sum_{j_1} \sum_{j_2}\cdots \sum_{j_N} s_{j_1,j_2,\dots,j_N} u^{(1)}_{i_1,j_1} u^{(2)}_{i_2,j_2} \dots u^{(N)}_{i_N,j_N},</math>
 
where the <math>U^{(n)} = [u^{(n)}_{i,j}]_{I_n \times I_n}</math> matrices and the <math>\mathcal{S} = [s_{j_1,\dots,j_N}]_{I_1 \times I_2 \times \cdots \times I_N}</math> core tensor should satisfy certain requirements (similar ones to the matrix SVD), namely
 
* Each <math>U^{(n)}</math> is an [[orthogonal matrix]] (called ''n''-mode singular matrix).
* Two subtensors of the core tensor <math>\mathcal{S}</math> are orthogonal i.e., <math>\langle\mathcal{S}_{i_n = p}, \mathcal{S}_{i_n = q}\rangle = 0</math> if <math>p \neq q</math>.
* The subtensors in the core tensor <math>\mathcal{S}</math> are ordered according to their [[Frobenius norm]], i.e. <math>\|\mathcal{S}_{i_n = 1}\| \geq  \|\mathcal{S}_{i_n = 2}\| \geq \dots \geq \|\mathcal{S}_{i_n = I_n}\|</math> for ''n''&nbsp;=&nbsp;1,&nbsp;...,&nbsp;''N''.
 
Notation:
:<math>\mathcal{A} = \mathcal{S} \times_{n=1}^N U^{(n)}</math>
 
=== Algorithm ===
 
The HOSVD can be built from several SVDs, as follows:<ref name="Lieven De Lathauwer, Bart De Moor and Joos Vandewalle 2000"/>
 
Given a tensor, ''T'' of shape <math>d_1\times d_2\times\cdots\times d_n</math>, the ''i''<sup>th</sup> singular tensor is given by making a matrix,
: <math>T_{(i)}</math>, the <math>d_i\times (\prod _{j \neq i} d_j)</math> matrix corresponding to <math>T</math>.
taking its left singular vectors, <math>U_{(i)}</math>.
 
The core tensor is then the tensor product of those <math>U_{(i)}</math>s.
 
== Applications ==
Main applications are extracting relevant information from multi-way arrays. Used in factor analysis, face recognition ([[TensorFaces]]), human motion analysis and synthesis.  
 
The HOSVD has been successfully applied to signal processing and big data, e.g., in genomic signal processing.<ref>{{Cite journal
| author = L. Omberg, G. H. Golub and O. Alter
| title = A Tensor Higher-Order Singular Value Decomposition for Integrative Analysis of DNA Microarray Data From Different Studies
  | journal = PNAS
| volume = 104
| issue = 47
| pages = 18371–18376
| date = November 2007
| doi = 10.1073/pnas.0709146104
| url = http://dx.doi.org/10.1073/pnas.0709146104
}}</ref><ref>{{Cite journal
| author = L. Omberg, J. R. Meyerson, K. Kobayashi, L. S. Drury, J. F. X. Diffley and O. Alter
| title = Global Effects of DNA Replication and DNA Replication Origin Activity on Eukaryotic Gene Expression
| journal = Molecular Systems Biology
| volume = 5
| pages = 312
| date = October 2009
| doi = 10.1038/msb.2009.70
| url = http://dx.doi.org/10.1038/msb.2009.70
| id = [http://www.alterlab.org/research/highlights/msb.2009.70_Highlight.pdf Highlight]
| issue=1
}}</ref><ref>{{Cite journal
| author = C. Muralidhara, A. M. Gross, R. R. Gutell and O. Alter
| title = Tensor Decomposition Reveals Concurrent Evolutionary Convergences and Divergences and Correlations with Structural Motifs in Ribosomal RNA
| journal = PLoS ONE
| volume = 6
| issue = 4
| pages = e18768
| date = April 2011
| doi = 10.1371/journal.pone.0018768
| url = http://dx.doi.org/10.1371/journal.pone.0018768
| id = [http://www.alterlab.org/research/highlights/pone.0018768_Highlight.pdf Highlight]
}}</ref> These applications also inspired a higher-order generalized singular value decomposition (HO GSVD).<ref>{{Cite journal
| author = S. P. Ponnapalli, M. A. Saunders, C. F. Van Loan and O. Alter
| title = A Higher-Order Generalized Singular Value Decomposition for Comparison of Global mRNA Expression from Multiple Organisms
| journal = PLoS ONE
| volume = 6
| issue = 12
| pages = e28072
| date = December 2011
| doi = 10.1371/journal.pone.0028072
  | url = http://dx.doi.org/10.1371/journal.pone.0028072
| id = [http://www.alterlab.org/research/highlights/pone.0028072_Highlight.pdf Highlight]
}}</ref>
 
It is also used in [[tensor product model transformation]]-based controller design.<ref name=Baranyi04 /><ref name=compind /> In [[multilinear subspace learning]],<ref>Haiping Lu, K.N. Plataniotis and A.N. Venetsanopoulos, "[http://www.dsp.utoronto.ca/~haiping/Publication/SurveyMSL_PR2011.pdf A Survey of Multilinear Subspace Learning for Tensor Data]", Pattern Recognition, Vol. 44, No. 7, pp. 1540–1551, Jul. 2011.</ref> it is modified to [[multilinear principal component analysis]]<ref>H. Lu, K. N. Plataniotis, and A. N. Venetsanopoulos, "[http://www.dsp.utoronto.ca/~haiping/Publication/MPCA_TNN08_rev2010.pdf MPCA: Multilinear principal component analysis of tensor objects]," IEEE Trans. Neural Netw., vol. 19, no. 1, pp. 18–39, Jan. 2008.</ref> for gait recognition.
 
== References ==
{{Reflist}}
 
{{DEFAULTSORT:Higher Order Singular Value Decomposition}}
[[Category:Multilinear algebra]]

Latest revision as of 14:33, 21 July 2014

Is your business frequently losing out to competitors?

Does your slice of the marketing pie seem to be growing smaller each year? You probably need to think about how you can automate and optimize your business practices.
The word "automation" frequently brings to mind robots replacing humans in a factory setting. So unless your business is turning out thousands of widgets on a daily basis, you may believe that the topic of automation doesn't pertain to you. You're wrong about that.
When you consider automation, expand your thinking to include any use of the latest technologies that would make your business more efficient. Automation can increase productivity, reduce labor costs, reduce payroll overhead by using fewer staff or replacing expensive specialized positions with lower cost positions.

Automation can also ensure quality, consistency, and predictability through using standardized processes.
Companies that fail to streamline and automate usually can't grow or survive when competition appears and drives down prices and reduces profit margins. They find themselves in trouble when the market turns sour and their profits fall while their costs remain high.

Before this happens to your company, take a good hard look at your business practices from start to finish. Make a list of all the products or services you provide. List and describe your customers. Do you have agreements with cheap ugg boots other organizations that provide components for your business?

How do your customers and partners find you? How do you communicate with them? What do they want and expect from you? How do you manage your inventory? How do you advertise to your existing customers, and how do you market to potential clients? How do you manage your financials?

Be as analytical as possible. What methods do you use to create your products or develop your services? How do your products or services compare to your competitors? How do your business practices compare to theirs? Is your organization less efficient in its interactions with the marketplace?

Are you running to the store every time discount ugg boots you run out of a single item?
Don't forget to analyze everything that goes on inside your business, too. For example, how do your executives and employees communicate on a daily basis? How do you measure productivity and track sales? How do you account for all your income and expenses?
If you are not familiar with every aspect of your business, you may want to interview other employees to gather information about existing problems and solicit their suggestions cheap ugg boots on how processes might be improved.

After you have a thorough understanding of all the current processes within your organization, you have a lot of areas to consider about how you might modernize. Can you take advantage of a new technology to make a process faster or more efficient? For example, many field workers now file daily reports on handheld devices such as smart phones or tablet computers that they carry with them from job to job.
This eliminates the need for those employees to travel from field to office to complete their work, as well as giving the office staff and executives an up-to-date summary of all the work accomplished each day.

With linked hi-tech networks, many computerized devices can deliver their own reports at regular intervals, as well as sound the alarm when there's a breakdown, send messages to human minders that parts or supplies need to be replaced, and so forth. This is much more efficient than employing someone to run around and constantly check gauges and supplies.

Consider moving some practices out of the office and putting them online. A good, thorough website can answer many questions and reduce the number of phone calls that an employee needs to handle. Developing an online catalog with detailed descriptions of products and services might win you many new customers.

An automated online ordering and tracking system could save your organization a lot of money in personnel costs, and can help you efficiently fill orders. Even using simple barcodes and scanners can highlight buying and shipping patterns you might not have noticed, and make inventory control and tracking easy.

Be sure to look at every process within your business. You may find you need to invest in a new computer system linked to smart devices like phones or tablets. You might want to develop more streamlined internal forms that feed information directly into a central database, which in turn automatically produces reports for the departments that need them.

You can also streamline personal habits such as shopping online and having supplies delivered instead of leaving the office, driving to stores and disrupting your workday.
You may need to outsource certain tasks that are not cost-efficient to automate within your company, or take advantage of new specialized technologies like 3-D printing. These days you can even automate advertising on the internet through online scheduling and targeting programs.

When you have developed a roadmap of how you might optimize your practices to position uggs on sale your business for the future, you should write a proposal or a feasibility study to describe your ideas to others in your organization. If you are not the head of the company, this could get you a promotion for being forward thinking.

If you are writing an internal company proposal, you'll want to explain what changes the organization should make and why, how much these changes will cost, and how these changes will benefit the company. Be as specific as possible, and include all the facts and figures you have accumulated.

If you are writing a feasibility study, you may want to compare various options (including the option of not making any changes), present all the benefits discount ugg boots and costs of each, and then leave the final decision up to others.

Just like every other process you have analyzed, you should consider how to optimize the task of creating business documents like proposals, studies, and reports. It is inefficient to start from scratch when there are already packages like proposal and report writing kits available.
These kits includes thousands of templates with examples and instructions on each page, as well as sample proposals, studies, and reports you can page through to get ideas. And kits with wizard software that helps you easily assemble any sort of proposal or report.

Ready-made kits are an excellent choice that can help anyone produce a professional document efficiently.