Private Cell Retrieval from Data Warehouses

© 2015 IEEE. Publicly accessible data warehouses are an indispensable resource for data analysis. However, they also pose a significant risk to the privacy of the clients, since a data warehouse operator may follow the client's queries and infer what the client is interested in. Private information retrieval (PIR) techniques allow the client to retrieve a cell from a data warehouse without revealing to the operator which cell is retrieved and, therefore, protects the privacy of the client's queries. However, PIR cannot be used to hide online analytical processing (OLAP) operations performed by the client, which may disclose the client's interest. This paper presents a solution for private cell retrieval from a data warehouse on the basis of the Paillier cryptosystem. By our solution, the client can privately perform OLAP operations on the data warehouse and retrieve one (or more) cell without revealing any information about which cell is selected. In addition, we propose a solution for private block download on the basis of the Paillier cryptosystem. Our private block download allows the client to download an encrypted block from a data warehouse without revealing which block in a cloaking region is downloaded and improves the feasibility of our private cell retrieval. Our solutions ensure both the server's privacy and the client's privacy. Our experiments have shown that our solutions are practical

Observation of rotationally mediated focused inelastic resonances in D2 scattering from Cu(001)

6 págs.; 4 figs.; 1 tab.Rotationally mediated focused inelastic resonances (RMFIR's) in the angular distributions of D2 scattered from Cu(001) are observed. The FIR effect involves a phonon-assisted focusing of an incident beam of arbitrary energy and direction into a final channel of one single well-defined energy and direction. Surprisingly for an incident energy Ei = 27 meV the RMFIR conditions for the scattered beam coincide with the kinematic conditions required for a further elastic selective adsorption mechanism called the rotationally mediated critical kinematic (RMCK) effect. By taking advantage of the RMFIR and elastic RMCK effects, three effective bound states of energy ¿n,J = -21.5 meV, -12.4 meV, and -10.3 meV are determined. They are attributed to the lowest bound states ¿0 = -28.9 meV and ¿1 = -19.8 meV combined with the rotational excitation energy for J = 1 to be BrotJ(J + 1) = 7.41 meV, respectively, and ¿3 = -10.3 meV combined with the rotational ground state (J = 0). While the ¿1 and ¿3 states appear as maxima in the angular distribution at RMFIR conditions, the ¿0 yields a striking minimum which represents the first evidence of what we call an anti-FIR feature. Theoretical arguments to explain the different FIR signatures observed are provided. A fit of a phenomenological interaction potential to the experimental bound-state values yields a value for the well depth D = 32.5 meV which is somewhat deeper than that found previously. © 1997 The American Physical SocietyS.M.A. acknowledges the Alexander von Humboldt Stiftung for support. G.B. was supported by Max-Planck Grant No. V-3.MPF-1028848. M.F.B. was supported by the ‘‘Training and Mobility of Researchers’’ Program of the European Union ~Grant No. ERB4001GT952431!. This work was started within the framework of Acciones Integradas Hispano-Alemanas Grant No. 165 A.Peer Reviewe

A new test of resistance in the diagnosis of postero-superior rotator cuff tears.

The aim of this study was to assess the diagnostic accuracy of a new clinical test for the diagnosis of subacromial impingement and full thickness postero-superior rotator cuff tears. One hundred and twenty patients who underwent arthroscopic treatment for acromioplasty or cuff repair were previously submitted to a new test of resistance. The test is performed in the standing position with the involved arm in 90 degrees abduction, 20 degrees -30 degrees anteposition and in external rotation (as for full-can test). Thus, the patient was invited to follow the way of a spiral drawn on a drawing sheet for 20 turns; 1 turn = from the centre to the end of the spiral and vice versa (spiral width = 20 cm). The test was considered positive when the patient was not able to conclude it due to strength decrease or to shoulder pain. Sensitivity, specificity, positive and negative predictive values as well as diagnostic accuracy were calculated for our test of resistance. The test resulted scarcely reliable as detector of subacromial impingement and not very reliable as detector of small tear. When the test is positive there is a high probability that a subacromial disease exists; instead, when it is negative there is a high probability that the patient has not a large or massive cuff tear. The resistance test (Gum-Turn test) adds to our armamentarium of physical examination signs in patients with painful shoulder and furnishes further information on possible dimensions of tendinous tear

A Study of Transparencies and the Overhead Projector in the Industrial Arts Wood Shop Program

It will be the purpose of this paper to discuss overhead projection and permanent transparencies using a set ot transparencies to teach a unit in the industrial arts wood shop program

Efecto del distanciamiento entre hileras sobre el peso del grano de trigo de diferentes ciclos en la región semiárida pampeana

La región semiárida pampeana se caracteriza por presentar ciertas particularidades edáficas y climáticas que tornan inestable la producción de trigo. Durante la etapa de determinación del número de granos por unidad de superficie se incrementan las posibilidades de que los cultivos sufran estrés hídrico. El llenado de los granos comienza pocos días después de floración. En esta etapa se incrementa el peso de los granos hasta alcanzar su madurez, quedando determinado el peso del grano y el rendimiento final del cultivo. El período crítico para la determinación del rendimiento en el cultivo de trigo coincide con el crecimiento de la espiga que se extiende desde la formación de espiguilla terminal hasta la antesis. El peso seco de las espigas en antesis es una medida del suministro de asimilados que recibieron las mismas durante el período crítico y por lo tanto es un adecuado predictor del número de granos que se fijarán. En la región triguera V Sur es frecuente observar deficiencias hídricas durante el llenado, que provocan limitaciones de fuente y reducen el peso de los granos. En este caso no solo se disminuye el rendimiento, sino que también se produce una merma de la calidad comercial del grano. Los objetivos del trabajo son: evaluar y cuantificar los efectos del ciclo y los distanciamientos entre surcos sobre el peso de los granos; verificar la relación entre el peso seco de las espigas a antesis y el rendimiento final del cultivo. Los ensayos se realizaron en la unidad de Módulos de Labranzas en el Campo de Enseñanza  de la Facultad de Agronomía de la UNLPam, con cultivares de tres diferentes ciclos sembrados a diferentes espaciamientos. El peso de los granos presentó diferencias significativas en los distanciamientos a 0,175 m y a 0,525 m. El cultivar de ciclo largo mostró una diferencia altamente significativa con respecto al ciclo intermedio y al corto. El ciclo largo presentó el mayor peso de espiga a floración sin diferencias significativas con el ciclo intermedio. Los menores pesos de espiga los presentó el cultivar de ciclo corto. En cuanto a tasa de llenado del grano el ciclo largo se diferenció significativamente desde mediados hasta el final del periodo de llenado en el menor distanciamiento, lo que se manifestó en un mayor peso final de los granos. El ciclo del cultivo afectó el peso final de los granos de trigo siendo el ciclo largo el de mejor resultado. El distanciamiento entre hileras no afectó el peso final de los granos en el ciclo corto e intermedio, pero si fue afectado en el ciclo largo. Los datos obtenidos no muestran una estrecha relación entre el peso seco de las espigas a floración y el rendimiento en los dos distanciamientos ensayados

Ferromagnetism in Li doped ZnO nanoparticles: The role of interstitial Li

ZnO nanoparticles doped with Li (Zn1−yLiyO, y ≤ 0.1) have been investigated with emphasis on the correlation between their magnetic, electronic, and structural properties. In particular, defects such as interstitial Li and Zn atoms, substitutional Li atoms, and oxygen vacancies have been identified by X-ray photoelectron spectroscopy(XPS) and their respective roles in stabilization of the magnetic moment are discussed. X-ray diffraction(XRD) and XPS give clear evidence of Li presence at both substitutional and interstitial sites. XPS studies further show that the amount of substitutional Li defects (Lizn) and interstitial Li defects (Lii) vary non-monotonically with the Li concentration, with the Lii defects being noticeably high for the y = 0.02, 0.08, and 0.10 concentrations, in agreement with the XRD results. Magnetization studies show room temperature ferromagnetism in these nanoparticles with the moment being largest for the particles with high concentration of interstitial lithium and vice versa. Both interstitialZn(Zni) defects and Zn-O bonds were determined from the Zn LMM Auger peaks; however, the variation of these with Li concentrations was not large. Oxygen vacancies (Vo) concentrations are estimated to be relatively constant over the entire Li concentration range. We relate the Lii and Zni defects to the formation and stabilization of Znvacancies and thus stabilizing the p-type ferromagnetism predicted for cation (zinc)vacancy in the ZnO type oxides