• 융합신호처리학회논문지
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• 제6권2호
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• pp.89-94
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• 2005

본 논문에서는 새로운 방법의 Fuzzy PID 제어기를 제안한다. 우선 절대형 디지털 PID 제어기에서 두 가지 문제점이 있다. 첫째는 매 제어 주기마다 많은 데이터의 합을 구해야 하므로 계산시간이 많이 소요되고, 둘째는 이 계산을 위해 이전의 모든 데이터를 보관하고 있어야 되기 때문에 메모리가 많이 필요한 문제점이 있다. 위의 문제점을 개선하기 위해 속도형 디지털 PID 제어기를 사용한다. 제안한 제어기에서는 PID 제어기의 목표 값과 현재 출력 값의 차인 크리스퍼(crisp) 출력 오차를 그대로 사용하지 않고 퍼지추론의 단계는 가지면서 Rule Table은 갖지 않는 특징이 있으며 출력 소속 함수에 두 변수의 관계와 범위에 의해 도식화된 영역에서 삼각형 무게 중심법으로 비퍼지화된 비선형 출력 값을 PID 계수에 인가하는 새로운 Fuzzy PID 제어기를 제안한다.

• 한국IT서비스학회지
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• 제12권4호
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• pp.369-380
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• 2013

The advent of the state-of-the-art technologies such as cloud computing and big data processing stimulates the provision of various new IT services, which implies that more servers are required to support them. However, the need for more servers will lead to more energy consumption and the efficient use of energy in the computing environment will become more important. The next generation nonvolatile RAM has many desirable features such as byte addressability, low access latency, high density and low energy consumption. There are many approaches to adopt them especially in the area of the file system involving storage devices, but their focus lies on the improvement of system performance, not on energy reduction. This paper suggests a novel approach for energy reduction in which the MRAM-based SSD is utilized as a storage device instead of the hard disk and a downsized page is adopted instead of the 4KB page that is the size of a page in the ordinary file system. The simulation results show that energy efficiency of a new approach is very effective in case of accessing the small number of bytes and is improved up to 128 times better than that of NAND Flash memory.

• IEIE Transactions on Smart Processing and Computing
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• 제2권6호
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• pp.367-372
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• 2013

Cloud computing technology has been developing at an increasing expansion rate. Today most of firms are using this technology, making improving the quality of service one of the most important issues. To achieve this, the system must operate efficiently with less idle time and without deteriorating the customer satisfaction. This paper focuses on enhancing the efficiency of a conventional Genetic Algorithm (GA) for task scheduling in cloud computing using Fuzzy Logic (FL). This study collected a group of task schedules and assessed the quality of each task schedule with the user expectation. The work iterates the best scheduling order genetic operations to make the optimal task schedule. General GA takes considerable time to find the correct scheduling order when all the fitness function parameters are the same. GA is an intuitive approach for solving problems because it covers all possible aspects of the problem. When this approach is combined with fuzzy logic (FL), it behaves like a human brain as a problem solver from an existing database (Memory). The present scheme compares GA with and without FL. Using FL, the proposed system at a 100, 400 and 1000 sample size*5 gave 70%, 57% and 47% better improvement in the task time compared to GA.

• 전기전자학회논문지
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• 제9권2호
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• pp.79-86
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• 2005

네트워크 트래픽의 증가와 다양한 멀티미디어 응용 서비스가 등장함에 따라 네트워크의 자원을 효과적으로 관리, 운용 및 서비스 품질의 향상을 위해 네트워크 트래픽을 실시간으로 감시하고 분석하는 것이 요구되고 있다. 기존의 소프트웨어 기반의 트래픽 측정 방식으로는 광대역 트래픽의 정확한 측정이 어려움으로 캡처, 헤더 매칭 등의 기능을 효율적으로 수행하는 미터 구조에 대한 연구가 필요하게 되었다. 따라서, 본 논문에서는 좀 더 효율적인 패킷 캡처를 위하여 임베디드 리눅스 기반의 하드웨어 미터링 시스템을 설계 및 구현하였다. 또한 10 기가비트 네트워크의 패킷 캡처에 대해 AweSim을 이용하여 시뮬레이션 모델을 작성하고 시뮬레이션을 통해 요구되는 시스템 버스와 메모리 대역폭을 분석하였다.

• International Journal of Aeronautical and Space Sciences
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• 제16권2호
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• pp.177-189
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• 2015

This paper presents an all-direct domain decomposition approach for large-scale structural analysis. The proposed approach achieves computational robustness and efficiency by enforcing the compatibility of the displacement field across the sub-domain boundaries via local Lagrange multipliers and augmented Lagrangian formulation (ALF). The proposed domain decomposition approach was compared to the existing FETI approach in terms of the computational time and memory usage. The parallel implementation of the proposed algorithm was described in detail. Finally, a preliminary validation was attempted for the proposed approach, and the numerical results of two- and three-dimensional problems were compared to those obtained through a dual-primal FETI approach. The results indicate an improvement in the performance as a result of the implementing the proposed approach.

• 환경위생공학
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• 제18권2호
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• pp.87-93
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• 2003

This study carried out to recommend adaptable technologies and countermeasures for performance improvement of Wet Scrubber(WS) in industrial waste incinerator. When not using the Activated Carbon(AC), the removal efficiency of dust and HCl is 73%, 92%. And particulate phase and gaseous phase dioxins removal efficiency was evaluated up to 31% and 12%. In this case, dioxins enrichment was not revealed in WS. When using the AC mixing with scrubbing water, the case of 1,000ppm, removal efficiency of particulate phase dioxins was about 51%, and gaseous phase dioxins was about 96%. The case of 2,000ppm, removal efficiency of particulate phase dioxins was about 55%, and gaseous phase dioxins was about 97%. And the case of 3,500ppm, the removal efficiency of particulate phase dioxins was about 35%, and gaseous phase dioxins was about 96% respectively. By this study, using the AC was more useful to remove the gaseous phase dioxins, and needed to use proper concentration of the AC, that in case of 3,500ppm, the particulate phase dioxins removal efficiency was more lower than other cases.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.240-245
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• 1998

Fuzzy information retrieval which uses the concept of fuzzy relation is able to retrieve documents in the way based on not morphology but semantics, dissimilar to traditional information retrieval theories. Fuzzy information retrieval logically consists of three sets : the set of documents, the set of terms and the set of queries. It maintains a fuzzy relational matrix which describes the relationship between documents and terms and creates a thesaurus with fuzzy relational product. It also provides the user with documents which are relevant to his query. However, there are some problems on building a thesaurus with fuzzy relational product such that it has big time complexity and it uses fuzzy values to be processed with flating-point. Actually, fuzzy values have to be expressed and processed with floating-point. However, floating-point operations have complex logics and make the system be slow. If it is possible to exchange fuzzy values with binary values, we could expect sp eding up building the thesaurus. In addition, binary value expressions require just a bit of memory space, but floating -point expression needs couple of bytes. In this study, we suggest a new method of building a thesaurus, which accelerates the operation of the system by pre-applying an ${\alpha}$-cut. The experiments show the improvement of performance and reliability of the system.

• 동의생리병리학회지
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• 제19권1호
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• pp.279-283
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• 2005

After initial recovery from acute carbon monoxide(CO) intoxication, some patients occasionally undergo severe neuropsychiatric deterioration, which is called postanomic delayed encephalopathy(sequelae). This is the clinical study about one patient, a 53-year-old woman, diagnosed with delayed encephalopathy after acute CO intoxication. The patient's symptoms were mental dysfunction including memory impairment and disorientation, aphasia, atrophy and weakness throughtout the body. She had completely recovered after an anomic episode, but the neurological symptoms that developed were preceded by an interval of apparent nomality.(the 'lucid interval'). She was characterized as suffering deficiency syndrome of the heart(心虛) and was prescribed for her an Ansinschungnoi-tang(安神淸腦湯), and thereafter her symptoms improved remarkably. For the evaluation of clinical improvement, we use the Modified Barthel Index(MBI).

• 대한전자공학회논문지SD
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• 제41권5호
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• pp.51-60
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• 2004

반도체 기술의 발달로 회로의 집적도와 복잡도가 증가함에 따라 칩의 생산 과정에서 고장이 발생하는 빈도가 높아지게 되었다. 칩의 수율을 향상시키고, 생산 단가를 절감시키기 위해서 고장의 원인을 찾아내고 분석하는 과정은 매우 중요하다. 그러나 고장의 원인을 분석하는 과정 중 고장의 위치를 찾아내는 데는 많은 시간이 소요된다. 게이트 수준에서의 고장 위치 진단은 물리적 수준에서의 고장 범위를 한정해 줌으로써 고장 위치를 찾는 데 소요되는 시간을 줄 일 수 있다는 데 의미를 갖는다. 본 논문에서는 새로운 방식의 고장 딕션너리 방식과 추가적인 고장 시뮬레이션 방식을 혼합하여, 메모리의 소비를 최소화하면서도 시뮬레이션 수행 시간을 단축시킴으로써 효과적으로 고장 진단을 수행할 수 있는 고장 진단 알고리듬을 제안한다.

• 한국멀티미디어학회논문지
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• 제13권4호
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• pp.496-503
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• 2010

어휘인식 시스템은 스탠드 얼론(Standalone)으로 개발되어 지고 있으며 휴대용 단말기에서 사용하였을 경우 메모리 공간의 제약과 오디오 압축으로 인해 인식률이 낮게 나타난다. 본 연구에서는 휴대용 단말기의 성능과 인식률 향상을 위하여 음향학적 탐색과 언어적 탐색을 분리하여 어휘 인식 속도를 개선한 시스템을 제안하였다. 음향학적 탐색은 휴대용 단말기에서 수행하고 보다 복잡한 언어적 탐색은 서버에서 처리하는 시스템으로 음성신호로부터 특징벡터를 추출하여 GMM을 이용한 음소인식을 수행하고, 인식된 음소 열을 서버로 전송하여 렉시컬 트리 탐색 알고리즘을 사용하여 언어적 탐색 단계에서 어휘 인식을 수행하였다. 시스템 성능 평가 결과 어휘 종속 인식률은 98.01%, 어휘 독립 인식률은 97.71%의 인식률을 나타냈으며 인식속도는 1.58초로 나타내었다.