• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제4권2호
• /
• pp.155-160
• /
• 2004

In this paper, we describe the results of a study on the edge enhancement of X-ray images by using their fuzzy system representation. A set of gray scale X-ray images was generated using the EGS4 computer code. An aluminum plate or a lead plate with three parallel strips taken out has been used as the object with the thickness and the width of the plate, and the gap between the two strips varied. We started with a comparative study on a set of the fuzzy sets for their applicability as the input fuzzy sets for the fuzzy system representation of the gray scale images. Then we describe how the fuzzy system is used to sharpen the edges. Our algorithm is based on adding the magnitude of the gradient not to the pixel value of concern but rather to the nearest neighboring pixel in the direction of the gradient. We show that this algorithm is better in maintaining the spatial resolution of the original image after the edge enhancement.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권8호
• /
• pp.2010-2026
• /
• 2013

The combination of biometrics and cryptography gains a lot of attention from both academic and industry community. The noisy biometric measurement makes traditional identity based cryptosystems unusable. Also the extraction of key from biometric information is difficult. In this paper, we propose an efficient biometric identity based signature scheme (Bio-IBS) that makes use of fuzzy extractor to generate the key from a biometric data of user. The component fuzzy extraction is based on error correction code. We also prove that the security of suggested scheme is reduced to computational Diffie-Hellman (CDH) assumption instead of other strong assumptions. Meanwhile, the comparison with existing schemes shows that efficiency of the system is enhanced.

• International Journal of Computer Science & Network Security
• /
• 제21권12호
• /
• pp.223-227
• /
• 2021

A treatment based on the algebraic operations on fuzzy numbers is used to replace the fuzzy problem into an equivalent crisp one. The finite difference technique is used to replace the continuous boundary value problem (BVP) of arbitrary order 1<α≤2, with fuzzy boundary parameters into an equivalent crisp (algebraic or differential) system. Three numerical examples with different behaviors are considered to illustrate the treatment of the singular perturbed case with different fractional orders of the BVP (α=1.8, α=1.9) as well as the classical second order (α=2). The calculated fuzzy solutions are compared with the crisp solutions of the singular perturbed BVP using triangular membership function (r-cut representation in parametric form) for different values of the singular perturbed parameter (ε=0.8, ε=0.9, ε=1.0). Results are illustrated graphically for the different values of the included parameters.

• 한국수학사학회지
• /
• 제22권3호
• /
• pp.31-44
• /
• 2009

현재 융합과학의 모델로 주목받고 있는 인지과학을 이해하기 위해서는 세 가지의 중대한 수학적 업적을 살펴볼 필요가 있다. 본 논문에서는 이 세 가지의 역사적 업적에 해당하는 튜링기계, 신경망, 괴델의 불완전성 정리를 중심으로 인지과학의 수학적 기틀을 연구한다. 먼저, 메타수학으로서의 인지과학을 고찰한다. 다음으로 컴퓨터의 수학적 모델로서 튜링기계와 그 발전을 탐구하고, 뇌의 수학적 모델로서 신경망과 그 발전을 탐구하고자 한다. 마지막으로는 인지과학의 미래를 위한 괴델의 불완전성 정리의 함의를 논의하고 양자인지과학을 전망한다.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (A)
• /
• pp.484-489
• /
• 2006

Private Matching은 각기 다른 두 참여자 (two-party)가 가진 데이터의 교집합 (intersection)을 구하는 문제이다. Private matching은 보험사기 방지시스템 (insurance fraud detection system), 의료정보 검색, 항공기 탐승 금지자 목록 (Do-not-fly list) 검색 등에 이용될 수 있으며 다자간의 계산 (multiparty computation)으로 확장하면 전자투표, 온라인 게임 등에도 이용될 수 있다. 2004년 Freedman 등은 이 문제를 확률적 (probabilistic)으로 해결하는 프로토콜 (protocol) [1]을 제안하고 악의적인 공격자 (malicious adversary) 모델과 다자간 계산으로 확장하였다. 이 논문에서는 기존의 프로토콜을 결정적 (deterministic) 방법으로 개선하여 Semi-Honest 모델에서 결과의 정확성을 보장하는 한편, 이를 악의적인 공격자 모델에 확장하여 신뢰도와 연산속도를 향상시키는 새로운 프로토콜을 제안한다.

• 한국학교수학회논문집
• /
• 제10권1호
• /
• pp.27-43
• /
• 2007

본 연구의 목적은 이공계 대학생들에게 수학에 대한 동기유발과 수학학습에 도움을 주기 위하여 기반 학습 시스템을 개발하는 것이다. 이를 위하여 Mathematica와 웹 연동을 가능하게 해주는 webMathematica를 사용하여 이공계 대학생을 위한 미적분학습용 웹 콘텐츠 시스템인 MathBooster를 제작하였다. 이공계 대학생을 위한 웹 콘텐츠의 구성은 먼저 미적분의 개념을 그래프와 같은 시각화한 그림을 사용함으로써 흥미와 동기의 유발, 그리고 개념 형성을 위해 요소 지식에 관련된 내용을 수식과 텍스트로 제시하였다. 또한 단계별 풀이과정이 제시되는 예제를 제공하여 개념의 이해를 통한 응용력을 배양하도록 콘텐츠를 제공하였다. 학습자의 이해력을 확인하기 위하여 퀴즈를 제공하였으며 베이지언 네트워크를 이용하여 학습자의 퀴즈 풀이 결과에 따라 해당 콘텐츠에 대한 학습의 이해 정도를 진단하는 기능을 개발하였다. 이공계 수학용 웹 콘텐츠의 형성평가를 위하여 MathBooster에 대한 사용자의 반응, 화면구성의 적절성, 실습하기 모드의 만족도, 퀴즈, 진단결과, 피드백 만족도 등의 네 영역으로 구분하여 설문지를 작성하였다. MathBooster의 실습을 마친 이공계 학생을 대상으로 설문지를 배포하였으며 영역별로 통계 처리한 결과 MathBooster 사용에 대한 높은 만족도를 보여 주었다. 이 결과에 따라 향후 시스템을 수정보완 할 과제를 제시하였다.

• 천문학논총
• /
• 제30권2호
• /
• pp.205-209
• /
• 2015

The Eclipsing Binaries Minima (BIMA) Monitoring Project is a CCD-based photometric observational program initiated by Bosscha Observatory - Lembang, Indonesia in June 2012. Since December 2012 the National Astronomical Research Institute of Thailand (NARIT) has joined the BIMA Project as the main partner. This project aims to build an open-database of eclipsing binary minima and to establish the orbital period of each system and its variations. The project is conducted on the basis of multisite monitoring observations of eclipsing binaries with magnitudes less than 19 mag. Differential photometry methods have been applied throughout the observations. Data reduction was performed using IRAF. The observations were carried out in BVRI bands using three different small telescopes situated in Indonesia, Thailand, and Chile. Computer programs have been developed for calculating the time of minima. To date, more than 140 eclipsing binaries have been observed. From them 71 minima have been determined. We present and discuss the O-C diagrams for some eclipsing binary systems.

• East Asian mathematical journal
• /
• 제16권2호
• /
• pp.251-266
• /
• 2000

The problem of solution uniqueness to the task of determining unknown parameters of mathematical models from input-output observations is studied. This problem is known as structural identifiability problem. We offer a new approach for testing structural identifiability of linear state space models. The approach compares favorably with numerous methods proposed by other authors for two main reasons. First, it is formulated in obvious mathematical form. Secondly, the method does not involve unfeasible symbolic computations and thus allows to test identifiability of large-scale models. In case of non-identifiability, when there is a set of solutions to the task, we offer a method of computing functions of the unknown parameters which can be determined uniquely from input-output observations and later used as new parameters of the model. Such functions are called parametric functions capable of estimation. To develop the method of computation of these functions we use Lie group transformation theory. Illustrative example is given to demonstrate applicability of presented methods.

• Computers and Concrete
• /
• 제30권4호
• /
• pp.269-276
• /
• 2022

In this paper, frequency vibrations of double-walled carbon nanotubes (CNTs) has been investigated based upon nonlocal elastic theory. The inference of small scale is being perceived by establishing nonlocal Love shell model. The wave propagation approach has been operated to frame the governing equations as eigen value system. An innovational nonlocal model to examine the scale effect on vibrational behavior of armchair, zigzag and chiral of double-walled CNTs. An appropriate selection of material properties and nonlocal parameter has been considered. The influence of dimensionless nonlocal parameter has been studied in detail. The dominance of end condition via nonlocal parameter is explained graphically. The results generated furnish the evidence regarding applicability of nonlocal shell model and also verified by earlier published literature.

• Steel and Composite Structures
• /
• 제42권3호
• /
• pp.353-361
• /
• 2022

In this study, an estimation regarding nonlocal shell model based on wave propagation approach has been considered for vibrational behavior of the double walled carbon nanotubes with distinct nonlocal parameters. Vibrations of double walled carbon nanotubes for chiral indices (8, 3) have been analyzed. The significance of small scale is being perceived by developing nonlocal Love shell model. The influence of changing mechanical parameter Poisson's ratio has been investigated in detail. The dominance of boundary conditions via nonlocal parameter is shown graphically. It is found that on increasing the Poisson's ratio, the frequencies increases. It is noted that the frequencies of clamped-clamped frequencies are higher than that of simply-supported and clamped-free edge conditions. The outcomes of frequencies are tested with earlier computations.