Privacy preserving data mining

A fruitful direction for future data mining research will be the development of technique that incorporates privacy concerns. Specifically, we address the following question. Since the primary task in data mining is the development of models about aggregated data, can we develop accurate models without access to precise information in individual data records? We analyze the possibility of privacy in data mining techniques in two phasesrandomization and reconstruction. Data mining services require accurate input data for their results to be meaningful, but privacy concerns may influence users to provide spurious information. To preserve client privacy in the data mining process, techniques based on random perturbation of data records are used. Suppose there are many clients, each having some personal information, and one server, which is interested only in aggregate, statistically significant, properties of this information. The clients can protect privacy of their data by perturbing it with a randomization algorithm and then submitting the randomized version. This approach is called randomization. The randomization algorithm is chosen so that aggregate properties of the data can be recovered with sufficient precision, while individual entries are significantly distorted. For the concept of using value distortion to protect privacy to be useful, we need to be able to reconstruct the original data distribution so that data mining techniques can be effectively utilized to yield the required statistics. Analysis Let xi be the original instance of data at client i. We introduce a random shift yi using randomization technique explained below. The server runs the reconstruction algorithm (also explained below) on the perturbed value zi = xi + yi to get an approximate of the original data distribution suitable for data mining applications. Randomization We have used the following randomizing operator for data perturbation: Given x, let R(x) be x+€ (mod 1001) where € is chosen uniformly at random in {-100…100}. Reconstruction of discrete data set P(X=x) = f X (x) ----Given P(Y=y) = F y (y) ---Given P (Z=z) = f Z (z) ---Given f (X/Z) = P(X=x | Z=z) = P(X=x, Z=z)/P (Z=z) = P(X=x, X+Y=Z)/ f Z (z) = P(X=x, Y=Z - X)/ f Z (z) = P(X=x)*P(Y=Z-X)/ f Z (z) = P(X=x)*P(Y=y)/ f Z (z) Results In this project we have done two aspects of privacy preserving data mining. The first phase involves perturbing the original data set using ‘randomization operator’ techniques and the second phase deals with reconstructing the randomized data set using the proposed algorithm to get an approximate of the original data set. The performance metrics like percentage deviation, accuracy and privacy breaches were calculated. In this project we studied the technical feasibility of realizing privacy preserving data mining. The basic promise was that the sensitive values in a user’s record will be perturbed using a randomizing function and an approximate of the perturbed data set be recovered using reconstruction algorithm

Private Data Transfer over a Broadcast Channel

We study the following private data transfer problem: Alice has a database of files. Bob and Cathy want to access a file each from this database (which may or may not be the same file), but each of them wants to ensure that their choices of file do not get revealed even if Alice colludes with the other user. Alice, on the other hand, wants to make sure that each of Bob and Cathy does not learn any more information from the database than the files they demand (the identities of which will be unknown to her). Moreover, they should not learn any information about the other files even if they collude. It turns out that it is impossible to accomplish this if Alice, Bob, and Cathy have access only to private randomness and noiseless communication links. We consider this problem when a binary erasure broadcast channel with independent erasures is available from Alice to Bob and Cathy in addition to a noiseless public discussion channel. We study the file-length-per-broadcast-channel-use rate in the honest-but-curious model. We focus on the case when the database consists of two files, and obtain the optimal rate. We then extend to the case of larger databases, and give upper and lower bounds on the optimal rate.Comment: To be presented at IEEE International Symposium on Information Theory (ISIT 2015), Hong Kon

Sensitivity analysis of oil production models to reservoir rock and fluid properties

In this fast-growing world, the demands for energy supply are growing rapidly as well. The oil has become one of the basic needs of human beings in this era. Hence, to meet the supply of the growing world, the available oil cannot be extraced with primitive methods. This can be achieved by increasing the reservoir contact for which long horizontal wells can be used. Despite having many advantages of a long horizontal well, there are still some drawbacks in this type of well which is early water coning and water breakthrough. These issues can be fixed by using ICDs, which can balance the drawdown pressure in horizontal well thus delaying the water breakthrough time. With sensitivity analysis on different input parameters, not only these problems can be tackled but also can be distinguish which of the parameter affect the most to production. Norne oil field was discovered in 1992 in Norwegian sea and the production started from 1997. Since, the main objective of this thesis is to analyze the oil production model, Norne oil field was chosen as the real case. All the simulations were done considering the characteristics of well 6608/10-D-2H of Norne oil field assuming the reservoir to be homogenous. OLGA in combination with Rocx is being used for modelling and simulations. The base case model of well 6608/10-D-2H was first completed using the simulation tool on which differential analysis method for sensitivity analysis was implemented. The principle of this method is changing the value of one parameter and keeping all other parameter constant. So, changing the values of the parameters by 20% from its original value, and keeping all other parameter constant, simulations in OLGA were done for 200 days. The results shows that the most affected input parameter in case of oil production was oil density, with a value of sensitivity coefficient 1.6097, which was followed by initial water saturation, viscosity, absolute and relative permeability. Similarly, in case of water produced, the most affected input parameter was found to be initial water saturation with a sensitivity coefficient 4.515, followed by water density, viscosity, absolute and relative permeability. Moreover, it was observed that rock compressibility had no effect in either oil or water production

Comparison of Pethidine and Tramadol for Control of Shivering in Patients undergoing Elective Surgery under Spinal Anesthesia

Introduction: Shivering is a common problem faced by an anesthesiologist during intraoperative as well as in postoperative period, specially after sub-arachnoid block (SAB). It is unpleasant and undesirable and is secondary to vasodilation following sympathetic blockade. The present study was designed to evaluate the efficacy of pethidine on postoperative shivering following SAB and to compare its effects with those of tramadol. Methods: This randomized, prospective study was conducted in American society of anesthesiologists (ASA) grade I and II  patients undergoing surgery under SAB, to compare the efficacy of tramadol  and pethidine for control of shivering. Patients received tramadol or pethidine in a dose of 0.5mg/kg intra-venously after the appearance of shivering. Disappearance of shivering, side-effects as well as hemodynamics were observed at scheduled intervals. Results: There were a total of 79 patients randomized into two groups. There were 44 patients receiving pethidine (Group P) and the rest 35 receiving tramadol (Group T). Shivering score was significantly lower in Group P at 10, 15, 20, and 30 minutes compared to that in Group T. Sedation score was higher in pethidine group. Adverse effects in terms of nausea and vomiting was significantly higher in Group T. Conclusion: Pethidine provide better anti-shivering effect then tramadol with less side effects (nausea and vomiting)  but more sedation

Detailed imaging findings in a rare case of Kimura disease, with special mention on diffusion weighted imaging

Background: Kimura disease is an uncommon, benign, chronic, idiopathic disease that is seen mainly in the Asian population, particularly in females. It mainly affects the salivary glands and in particular parotid and cervical lymph nodes. So far, the diagnosis of Kimura disease has been based on histopathology. We hereby report of a confirmed case of Kimura disease and provide a detailed explanation of its imaging features with a special emphasis on diffusion-weighted imaging, as diffusion sequences may help distinguish Kimura disease from malignancy. Case Report: A middle-aged female patient presenting with a history of multiple chronic neck swellings was thoroughly evaluated by ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). The imaging findings included gross enlargement of the left parotid gland, a focal lesion in the right parotid gland, and cervical lymphadenopathy. These features correlated with histopathological findings, and the diagnosis of Kimura disease was made. Conclusions: The imaging findings were found to be specific for Kimura disease

Attrition in SMEs: The Cause

Human Resource managers are devising ways to retain talent next year that will see companies paying annual increments up to 30%. The average attrition in 2010 was 10% across Indian companies, a rate that may rise to 25% in 2011-12 with improved salaries (The Economic Times, Dec 24, 2010) The SMEs sector in India has certainly been a very prevalent are of employment in recent years but one of the biggest encounters it is facing is a remarkable rise in attrition rate. There could be some common attrition factor across industry but every organization need to know the reason for attrition. India's economy is showing a healthy progress, but employers enjoying the bang have a offhand side: that of restless staff seeking for a hotter career option leading to increasing attrition in Indian SMEs. Authors have tried to find out the reason for attrition in SMEs, what the factors that are leading to attrition in SMEs in India? A conceptual framework has been developed to understand the relation between the factors affecting attrition. Our findings suggested some crucial factors affecting attrition in SMEs. This paper may be help for entrepreneurs to dealt with attrition in the organizations. KEYWORDS: Attrition, SMEs, Entrepreneurship, Indian Economy, Indi