Wyniki wyszukiwania - Biblioteka Nauki

1

On Distributed k-Anonymization

100%

Zhong S.

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tom Vol. 92, nr 4

411-431

EN

When a database owner needs to disclose her data, she can k-anonymize her data to protect the involved individuals’ privacy. However, if the data is distributed between two owners, then it is an open question whether the two owners can jointly k-anonymize the union of their data, such that the information suppressed in one owner's data is not revealed to the other owner. In this paper, we study this problemof distributed k-anonymization. We have two major results: First, it is impossible to design an unconditionally private protocol that implements any normal k-anonymization function, where normal k-anonymization functions are a very broad class of k-anonymization functions. Second, we give an efficent protocol that implements a normal k-anonymization function and show that it is private against polynomial-time adversaries. Our results have many potential applications and can be extended to three or more parties.

2

An Efficient and Secure Cryptosystem for Encrypting Long Messages

100%

Zhong S.

Fundamenta Informaticae

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2006

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tom Vol. 71, nr 4

493-497

EN

Traditionally, due to efficiency considerations, when encrypting long messages using an asymmtric cryptosystem, one needs to use a symmetric cryptosystem in addition. To eliminate this requirement, Hwang, Chang, and Hwang introduced an asymmetric cryptosystem for encrypting long messages. However, they did not give any formal proof of the security of this cryptosystem. In this paper, we propose an improved asymmetric cryptosystem for encrypting long messages, which is both efficient and secure. In the aspect of efficiency, our cryptosystem is about twice as fast as the Hwang-Chang-Hwang cryptosystem. In the aspect of security, besides providing an informal analysis, we rigorously show that computing any part of the plaintext message encrypted using our cryptosystem is as hard as breaking the ElGamal cryptosystem, even if all other parts of the message are already known to the adversary.

3

First-principle calculations of effective mass of silicon crystal with vacancy defects

51%

Zhong S. , Wu M. , Lei X.

Materials Science Poland

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2016

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tom Vol. 34, No. 4

916--923

EN

The energy band structures and electron (hole) effective masses of perfect crystalline silicon and silicon with various vacancy defects are investigated by using the plane-wave pseudopotential method based on density functional theory. Our results show that the effect of monovacancy and divacancy on the energy band structure of crystalline silicon is primarily reflected in producing the gap states and the local states in valence band maximum. It also causes breaking the symmetry of energy bands resulting from the Jahn-Teller effect, while only producing the gap states for the crystalline silicon with hexavacancy ring. However, vacancy point defects could not essentially affect the effective masses that are derived from the native energy bands of crystalline silicon, except for the production of defect states. Simultaneously, the Jahn-Teller distortions only affect the gap states and the local states in valence band maximum, but do not change the symmetry of conduction band minimum and the nonlocal states in valence band maximum, thus the symmetry of the effective masses. In addition, we study the electron (hole) effective masses for the gap states and the local states in valence band maximum.

4

A Type Design Method of Large Hydraulic Turbine Based on The Gaussian Mixture Model

51%

Lin L. , Zhong S. , Xie X.

Przegląd Elektrotechniczny

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2012

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tom R. 88, nr 9b

153-156

EN

Because of the complex fluid motion in hydraulic turbine and the imperfect design theory, the selection design of Large-scale hydraulic turbine is achieved based on the calculation and analysis on the synthetic characteristic curves, which is subjectivity and low efficiency. To solve this problem, the Gaussian mixture model is used to extract the geometric features from the synthetic characteristic curves so that the retrieval process of the model wheel can be achieved by these geometric features. The search model of the running area from the synthetic characteristic curves is build based on the contour curve similarity transformation method. In the paper, the Monte Carlo method is adopted to obtain the mean values of the synthetic characteristics in the running area so that the evaluation targets can be established by combining the mean values with the hydraulic turbine design experiences. Finally the validity of running area can be evaluated by the evaluation targets. The test results show that the accuracy and efficiency of the selection design of Large-scale hydraulic turbine can be improved by the proposed method.

PL

W artykule przedstawiono problemy projektowania dużych turbin hydraulicznych. Zaproponowano model matematyczny bazujący na mieszanym modelu Gaussa w celu wydobycia parametrów geometrycznych. Zaadaptowano metodę Monte Carlo do określania średnich wartości syntetycznych charakterystyk w obszarze pracy.

5

Fluoroimmunoassay of human thymidine kinase 1 using magnetic nanoparticles

51%

Zhong S. , Qi F. , Xu M.

Chemia Analityczna

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2009

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tom Vol. 54, No. 5

827-839

EN

Human thymidine kinase 1 (hTKl) is a new tumor biomarker in serum. We developeda fluorescence enhancing immunoassay of hTKl, using magnetic nanoparticles (MNPs) j as the biomolecular immobilization mediator. The horseradish peroxidase labeled hTK 1 monoclonal antibody (HRP-Ab) competitively reacts with free hTKl in the detection solution and the hTKl bound to MNPs. After separation in a magnetic field, HRP-Ab bound to MNPs catalyzes oxidization of 3-(p-hydroxyphenyl)-propionic acid (HPPA) to form a iluorescent dimer product, 2,2'-dihydroxybiphenyl-5,5'-dipropionic acid, which leads to an enhanced fluorescent signal at 407 nm. The enhancement is inversely proportional to the hTKl concentration. The hTKl can be determined in the range 0.01-1 ng mL-1 and the detection limit reaches 0.008 ng mL-1. The hTKl concentrations in serum samples of several live cancer and healthy patients were correctly evaluated by the developed fluoroimmunoassay. This new immunoassay system is simple, fast, and sensitive for the detection of hTKl, offering a promising alternative method that can be extended to detect other biomarker molecules. It may have broad potential applications in clinical diagnosis.

PL

Ludzka tymidynowa kinaza 1 (hTK 1) jest nowym bioznacznikiem raka w surowicy. Opracowano metodę oznaczania (immunoassay) hTK l opartą na wzmocnieniu fluorescencji z wykorzystaniem magnetycznych nanocząsteczek (MNPs) jako mediatorów biomoleku-larnego unieruchomienia. Monoklonalne antyciało hTK l znakowane peroksydazą chrzanową (HRP-Ab) reaguje zarówno z wolnym hTK l jak i związanym z MNPs. Po wydzieleniu .. w polu magnetycznym, HRP-Ab związane z MNPs katalizuje utlenianie 3-(p-hydroksy-fenolo)-propionowego kwasu (HPPA) do fluoryzującego dimeru 2,2'-dihydroksybifenylu--5,5'-dipropionowego kwasu (HPPA) co prowadzi do zwiększenia fluorescencji w 407 nm. Wzmocnienie fluorescencji było odwrotnie proporcjonalne do stężenia hTK 1. Przedział oznaczania hTK l wynosił od 0,01 do l ngmL-1, a granica wykrywalności 0.008 ngml.-1. Opracowaną metodę zastosowano do oznaczania hTK l w próbkach surowicy zdrowych i chorych na raka pacjentów. Opracowana metoda jest prosta, szybka i czuła. Stanowi obiecującą alternatywę dla innych metod. Może być rozszerzona na inne bioznaczniki.