• 제어로봇시스템학회논문지
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• 제13권5호
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• pp.434-443
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• 2007

Presently, the exploration of an unknown environment is an important task for thee new generation of mobile service robots and mobile robots are navigated by means of a number of methods, using navigating systems such as the sonar-sensing system or the visual-sensing system. To fully utilize the strengths of both the sonar and visual sensing systems. This paper presents a technique for localization of a mobile robot using fusion data of multi-ultrasonic sensors and vision system. The mobile robot is designed for operating in a well-structured environment that can be represented by planes, edges, comers and cylinders in the view of structural features. In the case of ultrasonic sensors, these features have the range information in the form of the arc of a circle that is generally named as RCD(Region of Constant Depth). Localization is the continual provision of a knowledge of position which is deduced from it's a priori position estimation. The environment of a robot is modeled into a two dimensional grid map. we defines a vision-based environment recognition, phisically-based sonar sensor model and employs an extended Kalman filter to estimate position of the robot. The performance and simplicity of the approach is demonstrated with the results produced by sets of experiments using a mobile robot.

• Nuclear Engineering and Technology
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• 제40권5호
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• pp.365-374
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• 2008

Dependability-critical systems, such as digital instrumentation and control systems in nuclear power plants, necessitate engineering techniques and tools to provide assurances of their safety and reliability. Determining system reliability at the architectural design phase is important since it may guide design decisions and provide crucial information for trade-off analysis and estimating system cost. Despite this, reliability and system engineering remain separate disciplines and engineering processes by which the dependability analysis results may not represent the designed system. In this article we provide an overview and application of our approach to build architecture-based, dynamic system models for dependability-critical systems and then automatically generate dynamic fault trees (DFT) for comprehensive, tool-supported reliability analysis. Specifically, we use the Architectural Analysis and Design Language (AADL) to model the structural, behavioral and failure aspects of the system in a composite architecture model. From the AADL model, we seek to derive the DFT(s) and use Galileo's automated reliability analyses to estimate system reliability. This approach alleviates the dependability engineering - systems engineering knowledge expertise gap, integrates the dependability and system engineering design and development processes and enables a more formal, automated and consistent DFT construction. We illustrate this work using an example based on a dynamic digital feed-water control system for a nuclear reactor.

• 한국정보시스템학회지:정보시스템연구
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• 제16권1호
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• pp.179-200
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• 2007

In this research, we study how task and KMS fit influences on KMS performance in large corporations during its practical use. Based on the task-technology fit theory and information system success model, we developed a research model by considering the characteristics of KMS for supporting tasks. We try to verify how individual traits, task traits, and KMS Units affect task-KMS fit and how task KMS fit influences on KMS performance. We surveyed 212 employees who were using KMS and working for the large-sized manufacturing firms. We analyzed the collected data from LISREL 8.54 for Windows, and found the following significant results. First user satisfaction is increased when KMS provides knowledge to help to perform task rather than KMS' functionality. Second, user satisfaction is increased when KMS is suitable for performing task Hence, we verified task-KMS fit is an antecedent of user satisfaction. Third, task-KMS fit and user satisfaction have significant impacts on KMS performance. And user satisfaction affected more heavily on KMS performance than task-KMS fit did. As a result, we realized an individual performance can be improved when task KMS fit is high and, consequently, user satisfaction is increased. Forth while the usefulness of task-KMS fit is demonstrated, causal factors such as individual traits, task traits, and KMS traits significantly affect task-KMS fit. Formalization and knowledge trait we significant in enhancing user satisfaction, but KMS self-efficacy, autonomy, md system trait are not. These results indicate that task-KMS fit variable is useful as a measure of KMS performance as well as that of user satisfaction. Based on these results, we conclude that when KMS supports task activity, performance can be significantly improved by coordinating the task with KMS.

• 한국정보시스템학회지:정보시스템연구
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• 제26권2호
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• pp.85-104
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• 2017

Purpose The purpose of this study is to improve the efficiency of the activities of loosely connected network organization through the platform(Ba) of knowledge sharing. Loosely connected network organizations have been tried to promote new work and complement the scarce resources through collaborations. NPO(Non-Profit Organization) is essential to establish cooperation networks in order to achieve the public interest on the basis of scarce resources. This study interpreted the Ba on the 'Change-On' program and analyzed the social networks of regional organizations through the activation of the Ba. The 'Change-On' program is conducted for several years to promote the efficiency of the NPO network by Daum Generation Foundation. Design/methodology/approach This study made a design to organize the Ba concept of Nonaka & Konno and presented a case of the Ba activated based on the NPO network of regional order. According to the social network analysis of regional cooperation within the network of participating organizations was extended, it was found that the principal plays a significant role as a central hub made. Findings According to the empirical analysis, this study illustrated that various types of network were formed among NPOs based on the 'Change-On'. Furthermore, the networks surrounding NPOs are extended to the other people connected to them. This means that the network of NPOs had been diversified via the facilitation of the Ba. This study throws new highlights on the new role for the Ba as a network promoter in addition to the partner as a technology-provider in the NPO ecosystem. Moreover, the network analysis between before-and-after can be used for the evaluation of the effectiveness of the various Ba programs.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제21권9호
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• pp.596-603
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• 2015

개념망(Concept Network)은 시멘틱 검색, 개인화 검색, 추천, 텍스트마이닝 기법의 개선 등에 필수적인 지식베이스이다. 최근 효과적인 개념망 구축을 위해 온톨로지를 기반으로 하여 개념의 표현을 확장시키는 연구가 활발하다. 이에 본 논문은 World Knowledge로 평가받고 있는 위키피디아 데이터를 '개념' 집합의 원천으로 활용하여 3차원 텍스트 표현 모델 기반 개념망을 구축하는 기법을 제안한다. 사실상 개념들 간의 관계 정보는 시간의 흐름에 따라 변동하기 때문에, 텍스트 문서로부터 도출되는 '개념'은 Formal Concept Analysis 이론체계의 개념에 따르는 것이 바람직하다. 이를 위해 본 논문은 하나의 개념을 '단어'와 '문서' 간의 2차원 행렬로 표현하여 문서집합에 잠재된 개념간의 연관망을 보다 정확하게 생성하게 한다.

• 한국지능시스템학회논문지
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• 제15권5호
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• pp.605-614
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• 2005

에이전트 기반 플렉시블 화상회의 시스템은 데스크 탑 컴퓨터로 화상회의 시스템을 이용할 때 발생하는 시스템의 내 외적인 다양한 변동 및 이용자에게 가해지는 부담의 감소를 목적으로 설계된 화상회의 이용 지원환경이다. 본 논문에서는 플렉시블 화상회의 시스템의 유연성을 개선하기 위한 한 방법으로서 서비스 품질 파라미터 조정 기법을 적용한 화상회의 매니저 에이전트 내 지식 부분을 새롭게 설계한 T-INTER(Tuning-INTER) 아키텍처를 제안한다. 제안한 아키텍처를 기반으로 구축된 플렉시블 화상회의 시스템은 일반 이용자들이 화상회의를 이용할 때 발생하는 서비스 품질 요구 변경 및 시스템 부담 등의 문제를 유연하게 해결한다. 매니저 에이전트는 다른 에이전트와 프로토콜을 이용하여 긴밀하게 협조를 하며, 문제 해결의 진행상황을 고려하면서 QoS 파라미터를 자동으로 조정한다. 조정된 파라미터에 의해서 시스템은 변동에 대한 유연한 대응이 가능하게 되었고, 또한 이용자에게 가해지는 부담도 감소한다. 결국, 제안 아키텍처를 적용한 시스템이 기존 시스템과 비교하여 유연성이 증가되었음을 실험을 통하여 증명한다.

• International Journal of Computer Science & Network Security
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• 제22권6호
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• pp.346-356
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• 2022

The jurisprudential legal rules govern the way Muslims react and interact to daily life. This creates a huge stream of questions, that require highly qualified and well-educated individuals, called Muftis. With Muslims representing almost 25% of the planet population, and the scarcity of qualified Muftis, this creates a demand supply problem calling for Automation solutions. This motivates the application of Artificial Intelligence (AI) to solve this problem, which requires a well-designed Question-Answering (QA) system to solve it. In this work, we propose a QA system, based on retrieval augmented generative transformer model for jurisprudential legal question. The main idea in the proposed architecture is the leverage of both state-of-the art transformer models, and the existing knowledge base of legal sources and question-answers. With the sensitivity of the domain in mind, due to its importance in Muslims daily lives, our design balances between exploitation of knowledge bases, and exploration provided by the generative transformer models. We collect a custom data set of 850,000 entries, that includes the question, answer, and category of the question. Our evaluation methodology is based on both quantitative and qualitative methods. We use metrics like BERTScore and METEOR to evaluate the precision and recall of the system. We also provide many qualitative results that show the quality of the generated answers, and how relevant they are to the asked questions.

• ETRI Journal
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• 제32권2호
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• pp.333-335
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• 2010

This letter proposes a non-coherent blind time-of-arrival (TOA) estimation scheme for impulse radio ultra-wideband systems. The TOA estimation is performed in two consecutive phases: the Rayleigh-quotient theorem-based coarse-signal acquisition (CSA) and the iterative-threshold-test-based fine time estimation (FTE). The proposed scheme serves in a blind manner without demanding any a priori knowledge of the channel and the noise. Analysis and simulations demonstrate that the proposed scheme significantly increases the signal detection probability in CSA and ameliorates the TOA estimation accuracy in FTE.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1722-1741
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• 2017

Intrusion detection techniques based on virtual machine introspection (VMI) provide high temper-resistance in comparison with traditional in-host anti-virus tools. However, the presence of semantic gap also leads to the performance and compatibility problems. In order to map raw bits of hardware to meaningful information of virtual machine, detailed knowledge of different guest OS is required. In this work, we present VDSM, a lightweight and general approach based on driver separation mechanism: divide semantic view reconstruction into online driver of view generation and offline driver of semantics extraction. We have developed a prototype of VDSM and used it to do intrusion detection on 13 operation systems. The evaluation results show VDSM is effective and practical with a small performance overhead.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
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• pp.181-184
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• 1997

This paper propose the systematic procedure of the fuzzy model based controller for the continuous nonlinear system. Fuzzy controller have been successfully applied to many uncertain and complex industrial plants. The design of the fuzzy controller mainly depends on the knowledge from the expert who are familiar with the plant by trial and error. Therefore we need more systematic approach to the design of the fuzzy controller. In this paper, we design fuzzy model based controller applied to the nonlinear system. Unlike the design procedures reported in[8] and[9], we use the nonlinear process directly in designing the controller. This controller has been successfully applied to an inverted pendulum.