Matrix Decomposition for Recommendation System
Jie Zhu,
Yiming Wei,
Binbin Fu
Issue:
Volume 4, Issue 4, August 2015
Pages:
65-70
Received:
11 June 2015
Accepted:
24 June 2015
Published:
4 July 2015
Abstract: Matrix decomposition, when the rating matrix has missing values, is recognized as an outstanding technique for recommendation system. In order to approximate user-item rating matrix, we construct loss function and append regularization constraint to prevent overfitting. Thus, the solution of matrix decomposition becomes an optimization problem. Alternating least squares (ALS) and stochastic gradient descent (SGD) are two popular approaches to solve optimize problems. Alternating least squares with weighted regularization (ALS-WR) is a good parallel algorithm, which can perform independently on user-factor matrix or item-factor matrix. Based on the idea of ALS-WR algorithm, we propose a modified SGD algorithm. With experiments on testing dataset, our algorithm outperforms ALS-WR. In addition, matrix decompositions based on our optimization method have lower RMSE values than some classic collaborate filtering algorithms.
Abstract: Matrix decomposition, when the rating matrix has missing values, is recognized as an outstanding technique for recommendation system. In order to approximate user-item rating matrix, we construct loss function and append regularization constraint to prevent overfitting. Thus, the solution of matrix decomposition becomes an optimization problem. Alt...
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Cyber-Physical Systems: A Framework for Prediction of Error in Smart Medical Devices
Sunday Anuoluwa Idowu,
Olawale Jacob Omotosho,
Olusegun Ayodeji Ojesanmi,
Stephen Olusola Maitanmi
Issue:
Volume 4, Issue 4, August 2015
Pages:
71-79
Received:
20 July 2015
Accepted:
7 August 2015
Published:
19 August 2015
Abstract: The objective of medical care services is designed to bring improvement to the health of patients. This is pursued with great vigor today with the use of modern health care systems which include medical sensors and automatically controlled actuation to deliver smart and proactive health services. The embedded devices control Smart Medical Devices (SMDs) used by physicians, Nurses, and Medical Staff which continuously interact with the human body or patient in one form or another. Cyber-Physical Systems (CPS) are integrations of computation with physical processes which are monitored and controlled by the embedded systems. CPS has positively affected a number of application areas which include communication, consumer energy, infrastructure, healthcare, manufacturing, military, robotics and transportation. The inappropriate use of these SMDs generate errors which are under-emphasized by stakeholders. Most users are only interested on the benefits derived in the use of SMDs and care-less on the danger that these devices can contribute to patients when used inappropriately. The error tendencies, possible factors and way forward is the subject matter of this paper. In order to achieve the stated objective, Input data was provided through a critical incident analysis of online database which provide readings from medical experts. These readings were compared to the standard world benchmarks and best practices. The difference between the readings and the standard benchmark were used to validate the existence of errors. A framework was developed for error prediction to improve safety in the use of SMDs. Due to the complexity of the problem, an algorithm was further developed to obtain an optimal solution of P1 to P5 within an acceptable threshold runtime which shows the gravity of these challenges on patients.
Abstract: The objective of medical care services is designed to bring improvement to the health of patients. This is pursued with great vigor today with the use of modern health care systems which include medical sensors and automatically controlled actuation to deliver smart and proactive health services. The embedded devices control Smart Medical Devices (...
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