• 한국시뮬레이션학회논문지
• /
• 제19권3호
• /
• pp.45-54
• /
• 2010

반도체 제조공정에 내재된 복잡성은 작업일정(job scheduling) 문제를 해석적 방법으로는 풀기 어렵기 때문에 보통 시스템 파라미터의 변화에 대한 효과를 이산사건 모델링 시뮬레이션에 의존하여 왔다. 한편 장비 고장 등 예측 불가능한 사건들은 고정된 작업일정 기법을 사용할 경우 전체 공정의 효율을 악화시킨다. 따라서 이러한 불확실성에 대해 최적의 성능을 내기 위해서는 작업일정을 실시간으로 대처 변경하는 것이 필요하다. 본 논문은 반도체 제조 공정에 대해 시스템 제어관점의 접근방법을 적용하여 이 문제에 적응형 실시간 작업제어 틀을 제안하고, DEVS 모델링 시뮬레이션 환경을 기반으로 제안된 틀을 설계 구현하였다. 제안된 방법은 기존의 임기응변적인 소프트웨어적인 방법에 비추어볼 때 전체 시스템을 이해하기 쉬우면서도 또한 추가되는 작업제어 규칙도 쉽게 추가 적용할 수 있는 유연성을 장점으로 가지고 있다. 여러 가지 실험결과 제안된 적응형 실시간 작업제어 프레임워크는 고정 작업규칙 방법에 비해 훨씬 나은 결과를 보여주어 그 효용성을 입증하였다.

• 디지털산업정보학회논문지
• /
• 제5권3호
• /
• pp.99-105
• /
• 2009

This paper suggests novel signal processing methods for optimal beamforming of smart antenna system in CDMA2000 mobile communication environments. This method utilize characteristics of the reverse pilot channel of CDMA2000 mobile communication systems, and applies them to improve the performance of an adaptive algorithm, which is used to a smart antenna system for beamforming. To perform the best beamforming, it is important to get an exact beamforming algorithm. This paper proposed an algorithm based on Laglange multiplier which has such an adaptive process, and also proposed the method to demodulate the received signal through array antenna using pilot channel in CDMA2000 environment. This paper analysed the enhanced performance of proposed algorithm in various signal environment through signal modeling of physical layer in CDMA2000 reverse link.

• 한국컴퓨터정보학회논문지
• /
• 제23권4호
• /
• pp.65-70
• /
• 2018

This paper describes a effective information compressor algorithm for the fourth industrial technology. One of the difficult problems for outdoor is to obtain effective updating process of background images. Because input images generally contain the shadows of buildings, trees, moving clouds and other objects, they are changed by lapse of time and variation of illumination. They provide the lowering of performance for surveillance system under outdoor. In this paper, a effective information algorithm for variable environment variable under outdoor is proposed, which apply the Kalman Estimation Modeling and adaptive threshold on pixel level to separate foreground and background images from current input image. In results, the better SNR of about 3dB~5dB and about 10%~25% noise distribution rate in the proposed method. Furthermore, it was showed that the moving objects can be detected on various shadows under outdoor and better result Information.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2007년도 춘계학술발표대회
• /
• pp.1107-1109
• /
• 2007

Context-based access control is an emerging approach for modeling adaptive solution, making access control management more flexible and powerful. However, these strategies are inadequate for the increased flexibility and performance that ubiquitous computing environment requires because such systems can not utilize effectively all benefit from this environment. In this paper, we propose a solution based on risk to make use of many context parameters in order to provide good decisions for a safety environment. We design a new model for risk assessment in ubiquitous computing environment and use risk as a key component in decision-making process in our access control model.

• 정보처리학회논문지D
• /
• 제15D권3호
• /
• pp.361-374
• /
• 2008

최근의 유비쿼터스 컴퓨팅 환경에서 요구되는 새로운 패러다임의 소프트웨어인 적응형 소프트웨어는 외부 환경 즉 문맥의 변화를 인식하고 자신의 운영 상태를 평가하여 스스로 동작행위를 바꾸는 능력을 가진 소프트웨어이다. 적응형 소프트웨어를 개발하기 위해서는 문맥에 대한 분석 및 설계와 더불어 동적인 문맥에 따라 적절히 대응할 수 있는 소프트웨어의 구조 및 행위를 설계하는 과정이 필요하다. 이것은 일반적인 소프트웨어보다 소프트웨어가 적응해야 하는 상황을 모델링 하는 기술이 필요하기 때문에 더 많은 노력이 필요하다. 본 논문에서는 재사용을 통해 개발의 효율성을 높이고자 적응형 소프트웨어를 위한 프로덕트 라인 아키텍처와 아키텍처 산출물의 템플릿을 제안한다. 아키텍처 산출물들은 프로덕트 라인의 공통성과 가변성을 명시적으로 표현하여 체계적인 핵심자산의 재사용 활동을 지원한다.

• 한국군사과학기술학회지
• /
• 제11권3호
• /
• pp.19-29
• /
• 2008

Underwater acoustic(UWA) communication is one of the most difficult field in terms of severe channel environments such as multipath propagation, high temporal and spatial variability of channel conditions. Therefore, it is important to model and analyze the characteristics of underwater acoustic channel such as multipath propagation, transmission loss, reverberation, and ambient noise. In this paper, UWA communication channel is modeled with a ray tracing method and applied to image transmission. Quadrature phase shift keying(QPSK) and multichannel decision feedback equalizer(DFE) are utilized as phase-coherent modulation method and equalization technique, respectively. The objective is to improve the performance of the image transmission using vertical sensor array instead of single sensor in the viewpoint of bit error rate(BER), constellation diagram, and received image quality.

• 정보과학회 논문지
• /
• 제42권11호
• /
• pp.1339-1348
• /
• 2015

서비스 지향 시스템 환경에서는 하나의 독립된 시스템이 다른 시스템에서 제공하는 서비스를 사용함으로써 시스템의 목표를 달성한다. 이러한 시스템 환경에서는 사용중인 서비스의 품질 저하가 실시간으로 시스템 장애를 유발할 수 있다. 기존 자가 적응 방법들은 서비스의 품질 저하 발생 후 대처하는 fault tolerance 방식을 따르고 있기 때문에 서비스 품질 저하로 인한 피해 발생을 예방하지 못한다. 따라서, 자가 적응 시스템의 신뢰도를 보존하기 위해서는 사용 중인 서비스를 fault tolerance 방식의 품질 기반 적응이 아닌 서비스 안정성 케이스를 기반으로 자가 적응해야 한다. 본 논문에서는 기존의 보증 속성 표현 방법인 Goal Structuring Notation 모델링을 활용하여 서비스 안정성 케이스를 표현 및 분석하기 위한 방법과, 서비스 안정성 케이스 분석 결과에 따른 적응 조치 방법, 서비스 생명주기에 따른 서비스 안정성 케이스 기반 자가 적응 메커니즘 적용 방법, 서비스 안정성 케이스 기반 자가 적응을 위한 프레임워크 아키텍처를 제안한다.

• 한국HCI학회:학술대회논문집
• /
• 한국HCI학회 2006년도 학술대회 1부
• /
• pp.519-525
• /
• 2006

Advances in information and telecommunication technology increasingly reveal the potential of computer supported education. However, most computer supported learning systems until recently did not pay much attention to different characteristics of individual learners. Intelligent learning environments adaptive to learner's preferences and tasks are desired. Each learner has different preferences and needs, so it is very crucial to provide the different styles of learners with different learning environments that are more preferred and more efficient to them. This paper reports a study of the intelligent learning environment where the learner's preferences are diagnosed using learner models, and then user interfaces are customized in an adaptive manner to accommodate the preferences. In this research, the learning user interfaces were designed based on a learning-style model by Felder & Silverman, so that different learner preferences are revealed through user interactions with the system. Then, a learning style modeling is done from learner behavior patterns using Decision Tree and Neural Network approaches. In this way, an intelligent learning system adaptive to learning styles can be built. Further research efforts are being made to accommodate various other kinds of learner characteristics such as emotion and motivation as well as learning mastery in providing adaptive learning support.

• 한국IT서비스학회지
• /
• 제11권sup호
• /
• pp.165-176
• /
• 2012

Context-Awareness system provides an appropriate service to user by recognizing situation from surrounding environment. There are many successful studies on this framework, but still has some limitations. In this paper, we are describing a context-awareness middleware that can enhance the limitation of the previous approaches. We first defined a new concept of context-awareness environment as a social intelligence. This concept implies that intelligent objects can make relationships, can aware of situation from surrounding environment, and can collaborate to accomplish a given task. The significance of the study is as follows. First, the system is capable of multi context-awareness since it is designed with a structure that supports multiple lines of reasoning. Second, the system is capable of context planning by adapting AI planning mechanism. Third, the system is capable of making the intelligent objects as a group for collaboration, and provides adaptive service to user. We have developed a prototype of the system and tested with a virtual scenario.

• 한국컴퓨터정보학회논문지
• /
• 제24권3호
• /
• pp.65-75
• /
• 2019

Non-Functional Requirements (NFR) play a crucial role during the software development process. Currently, NFRs are considered more important than Functional Requirements and can determine the success of a software system. NFRs can be very complicated to understand due to their subjective manner and especially their conflicting nature. Self-adaptive systems (SAS) are operating in dynamically changing environment. Furthermore, the configuration of the SAS systems is dynamically changing according to the current systems context. This means that the configuration that manages the trade-off between NFRs in this context may not be suitable in another. This is because the NFRs satisfaction is based on a per-context basis. Therefore, one context configuration to satisfy one NFR may produce a conflict with another NFR. Furthermore, current approaches managing Non-Functional Requirements trade-off stops managing them during the system runtime which of concern. To solve this, we propose fragmentizing the NFRs and their alternative solutions in form of Multi-entity Bayesian network fragments. Consequently, when changes occur, our system creates a situation specific Bayesian network to measure the impact of the system's conditions and environmental changes on the NFRs satisfaction. Moreover, it dynamically decides which alternative solution is suitable for the current situation.