• 정보보호학회논문지
• /
• 제10권3호
• /
• pp.11-28
• /
• 2000

In these days it is rapidly increasing that multi-user, multi-layered commercial software developments for companies or public institutions. Security services are necessary for most of systems and the access control service is the essential of security services. Current access control methods that are used as access control policies are classified as Discretionary Access Control Mandatory Access Control and Role Based Access Control. However there are some inefficiencies when those methods are applied to current multi-user, multi-layered systems. Therefore it is required that a new access control method that takes complex system resources into account from the side of policy. In this paper extending previous Role Based of 'Behavior' and a basic model of the method. And we simply implement the method on the mobile agent based workflow management system that is a representative example of multi-user. multi-layered softwares and shows implementation results to tap possibilities of real-world application.

• 한국멀티미디어학회논문지
• /
• 제25권10호
• /
• pp.1416-1432
• /
• 2022

The access control system is a system that allows users to selectively enter the building by granting an access key to the user for security. Access keys with weak security are easily exposed to attackers and cannot properly perform the role that authenticates users. Access code keys should be protected from forgery or spoofing. For this reason, access key verification service models is important in security. However, most models manage all access keys on one central server. This method not only interrupts all services due to server errors, but also risks forgery and spoofing in the process of transmitting access keys. Therefore, blockchain algorithms are used to reduce this risk. This paper proposes a blockchain-based access key verification service model that used distributed stored blockchain gateways on storing access keys and authenticates the user's identity based on them. To evaluate the performance of this model, an experiment was conducted to confirm the performance of the access key forgery recovery rate and the blockchain network performance. As a result, the proposed method is 100% forgery recovery rate, and the registration and verification process is evaluated at 387.58 TPS and 136.66 TPS.

• 한국정보과학회논문지:데이타베이스
• /
• 제32권2호
• /
• pp.193-203
• /
• 2005

XML은 인터넷 상에서 데이타의 표현 및 전송 표준으로 인식되고 있다. XPath는 XML 문서의 특정 부분을 규정하는 표준으로, XML 질의 처리와 접근 제어에 적합한 언어이다 본 논문에서는 XPath를 사용자 질의 및 접근 제어 정보를 표현하는 방법으로 사용하는 XML 접근 제어 방법을 제안한다. 제안하는 방법은 접근 제어 XPath 표현식을 통해 질의 XPath 표현식을 필터링하여 XML 문서에 대한 접근을 제어한다. 이를 위하여 XML 접근 제어 트리(XACT)를 정의하고, 이 트리를 이용하여 질의 XPath 표현식에서 접근 허용되는 부분만을 추출한다. XACT는 XML 엘리먼트들에 대한 구조적 요약으로 에지를 구성하고, 접근 제어 정보로 노드를 구성한 구조이다. 제안하는 방법의 정확성을 보이고, 기존방법과의 성능을 비교한다

• 한국통신학회논문지
• /
• 제36권1A호
• /
• pp.49-57
• /
• 2011

Random access method for Wibro system is proposed using the Bayesian Technique, which can estimate the number of bandwidth request messages in a frame only based on the number of successful slots. The performance measures such as the maximum average throughput, the mean delay time and the collision ratio are investigated to evaluate the performance of the proposed method. The proposed method shows better performance than the binary exponential backoff algorithm used currently.

• 한국의료질향상학회지
• /
• 제23권1호
• /
• pp.55-67
• /
• 2017

Purpose:The purpose of this study was to apply the disinfection method using chlorhexidine in practice on disinfection of vascular access for hemodialysis. Methods: This study was designed as a randomized controlled trial for examining effectiveness on infection of the vascular access device for hemodialysis when using chlorhexidine and betadine/alcohol. One-hundred-thirty study participants were separated into two groups randomly. Infection signs of the vascular access device for hemodialysis were observed and recorded before disinfection on vascular access device. Result: Before the study, there was no difference between the experimental group (chlorhexidine group) and the control group (betadine/alcohol group) in general characteristics and hematological index. Incidence of infection rate of chlorhexidine group was 0 percent and the betadine/alcohol group was 1.5 percent. There was no significant difference between the two groups. Conclusion: This study examined the effectiveness of prevention of infection with the disinfection method using chlorhexidine and betadine/alcohol. The disinfection method using chlorhexidine is considered an effective and alternative method of betadine/alcohol.

• Journal of Information Processing Systems
• /
• 제14권5호
• /
• pp.1150-1166
• /
• 2018

This paper presents a physical storage design method for image access structures using transformation techniques of multidimensional file organizations in image information systems. Physical storage design is the process of determining the access structures to provide optimal query processing performance for a given set of queries. So far, there has been no such attempt in the image information system. We first show that the number of pages to be accessed decreases as the shape of the given retrieval query region and that of the data page region become similar in the transformed domain space. Using these properties, we propose a method for finding an optimal image access structure by controlling the shapes of the page regions. For the performance evaluation, we have performed many experiments with a multidimensional file organization using transformation techniques. The results indicate that our proposed method is at least one to maximum five times faster than the conventional method according to the query pattern within the scope of the experiments. The result confirms that the proposed physical storage design method is useful in a practical way.

• Bulletin of the Korean Chemical Society
• /
• 제31권10호
• /
• pp.2889-2892
• /
• 2010

The objective of this study was to validate performance characteristics of the Access 2 (Beckman coulter) system for hCG assays for use as a confirmation test for doping control. The Access 2 assay was linear up to 500 IU/L. The correlation coefficient was higher than 0.999, and the sensitivity of the linearity was 0.82. There were no false positive or false negative cases. LOD was 0.59 IU/L. The method was robust when performed by different people. Repeatability and reproducibility were below 7%. We compared reproducibility and recoveries of Access 2 and Elecsys 2010. Access 2 demonstrated higher reproducibility than Elecsys 2010. Recoveries (accuracy) of Access 2 were between 85 and 105%. Recoveries for Elecsys 2010 were between 91 and 104%.

• Journal of Information Processing Systems
• /
• 제17권4호
• /
• pp.834-850
• /
• 2021

IT security companies have been releasing file system filter driver security solutions based on the whitelist, which are being used by several enterprises in the relevant industries. However, in February 2019, a whitelist vulnerability was discovered in Microsoft Edge browser, which allows malicious code to be executed unknown to users. If a hacker had inserted a program that executed malicious code into the whitelist, it would have resulted in considerable damage. File system filter driver security solutions based on the whitelist are discretionary access control (DAC) models. Hence, the whitelist is vulnerable because it only considers the target subject to be accessed, without taking into account the access rights of the file target object. In this study, we propose an industrial device security system for Windows to address this vulnerability, which improves the security of the security policy by determining not only the access rights of the subject but also those of the object through the application of the mandatory access control (MAC) policy in the Windows industrial operating system. The access control method does not base the security policy on the whitelist; instead, by investigating the setting of the security policy not only for the subject but also the object, we propose a method that provides improved stability, compared to the conventional whitelist method.

• 전자공학회논문지A
• /
• 제31A권7호
• /
• pp.1-16
• /
• 1994

In this paper, we propose a new multiple access scheme for VSAT(Very Small Aperture Terminal) data communications. The proposed scheme has better performance in terms of delay throughput than Controlled Multiaccess Scheme which has excellent performance. The proposed scheme use the spare reservation method, adaptation method to offered load, and fixed bandwidth reservation method. In this paper, we analyze the performance using simple queueing model and present the simulation results. When network traffic is very low, the new scheme and the controlled multiaccess scheme have almost the same access delay characteristic. As the network load becomes higher, the new scheme's access delay gain becomes larger. Futhermore, even when the network traffic is very high it is possible to access satellite link within the delay similar to one round-trip delay. In addition to access delay performance enhancement, the new scheme has facility that supports fixed bandwidth reservation. So it shows more enhanced performance in the environment that stream traffic is dominant such as in VSAT communication environment.

• Journal of Communications and Networks
• /
• 제18권3호
• /
• pp.439-445
• /
• 2016

In this paper, we consider subcarrier-index modulation (SIM) for precoded orthogonal frequency division multiplexing (OFDM) with a few activated subcarriers per user and its generalization to multi-carrier multiple access systems. The resulting multiple access is called sparse index multiple access (SIMA). SIMA can be considered as a combination of multi-carrier code division multiple access (MC-CDMA) and SIM. Thus, SIMA is able to exploit a path diversity gain by (random) spreading over multiple carriers as MC-CDMA. To detect multiple users' signals, a low-complexity detection method is proposed by exploiting the notion of compressive sensing (CS). The derived low-complexity detection method is based on the orthogonal matching pursuit (OMP) algorithm, which is one of greedy algorithms used to estimate sparse signals in CS. From simulation results, we can observe that SIMA can perform better than MC-CDMA when the ratio of the number of users to the number of multi-carrier is low.