• Industrial Engineering and Management Systems
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• 제4권1호
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• pp.94-101
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• 2005

This paper presents the first known application of a meta-heuristic algorithm, variable neighbourhood descent (VND), to the redundancy allocation problem (RAP). The RAP, a well-known NP-hard problem, has been the subject of much prior work, generally in a restricted form where each subsystem must consist of identical components. The newer meta-heuristic methods overcome this limitation and offer a practical way to solve large instances of the relaxed RAP where different components can be used in parallel. The variable neighbourhood descent method has not yet been used in reliability design, yet it is a method that fits perfectly in those combinatorial problems with potential neighbourhood structures, as in the case of the RAP. A variable neighbourhood descent algorithm for the RAP is developed and tested on a set of well-known benchmark problems from the literature. Results on 33 test problems ranging from less to severely constrained conditions show that the variable neighbourhood descent method provides comparable solution quality at a very moderate computational cost in comparison with the best-known heuristics. Results also indicate that the VND method performs with little variability over random number seeds.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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• pp.3108-3120
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• 2019

Point cloud is widely used in 3D applications due to the recent advancement of 3D data acquisition technology. Polygonal mesh-based compression has been dominant since it can replace many points sharing a surface with a set of vertices with mesh structure. Recent point cloud-based applications demand more point-based interactivity, which makes point cloud compression (PCC) becomes more attractive than 3D mesh compression. Interestingly, an exploration activity has been started to explore the feasibility of PCC standard in MPEG. In this paper, a new color attribute compression method is presented for point cloud data. The proposed method utilizes the spatial redundancy among color attribute data to construct a color palette. The color palette is constructed by using K-means clustering method and each color data in point cloud is represented by the index of its similar color in palette. To further improve the compression efficiency, the spatial redundancy between the indices of neighboring colors is also removed by marking them using a flag bit. Experimental results show that the proposed method achieves a better improvement of RD performance compared with that of the MPEG PCC reference software.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.827-839
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• 2021

Due to climate change and population growth, water scarcity is getting worse all over the world. Among various methods for desalination of seawater, the Multi-Effect Adsorptive Desalination method, which combines the existing Multi-Effect Desalination method and the Adsorptive Desalination method and can produce high-concentration-high-concentration freshwater, is emerging. Because the Multi-Effect Adsorptive Desalination method combines the two different methods, the system becomes complicated and the possibility of failure increases. Therefore, in this study, availability analysis was performed on the Multi-Effect Adsorptive Desalination process. A total of four types of reliability block diagrams were presented, and availability analysis was conducted based on them. The first form of a reliability block diagram is configured in series without any redundancy. The availability of the reliability block diagram composed of the serial system was found to be lower than the required availability. In order to increase availability, the redundancy to pumps and boiler are added to system. As a result of availability analysis, it was confirmed that designing desalination systems with redundancy to pump meets the 93% availability, which is typically required availability for various plants.

• 센서학회지
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• 제21권1호
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• pp.59-67
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• 2012

It was reported that the latest sensor technology allow an 65536 conductive polymer sensor array to be made with broad but overlapping selectivity to different families of chemicals emulating the characteristics found in biological olfaction. However, the supernumerary redundancy always accompanies great error and risk as well as an inordinate amount of computation time and local minima in signal processing, e.g. neural networks. In this paper, we propose a new method to reduce the number of sensor for analysis by reducing redundancy between sensors and by removing unstable sensors using the cosine similarity method and to decide on representative sensor using FCM(Fuzzy C-Means) algorithm. The representative sensors can be just used in analyzing. And, we introduce DWT(Discrete Wavelet Transform) for data compression in the time domain as preprocessing. Throughout experimental trials, we have done a comparative analysis between gas sensor data with and without reduced redundancy. The possibility and superiority of the proposed methods are confirmed through experiments.

• 미래기술융합논문지
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• 제2권3호
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• pp.9-15
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• 2023

최근, 정보화 사업이 확산됨에 따라 정보 시스템을 기반으로 다양한 공공 서비스가 수행되고 있다. 이러한 정보 시스템 기반의 공공 행정 서비스는 내부 업무 및 대외 서비스 등을 제공하고 있다. 최근에는 클라우드 기반의 공공 서비스 구축이 확장되면서 정보 시스템의 고도화가 관심을 받고 있다. 특히, 업무의 정보시스템 의존도가 증가하면서 정보 시스템의 중단 및 마비 등의 위험한 사태를 사전에 방지하기 위한 대응 체계 구축이 기업 뿐만 아니라 공공 기관에서도 화두가 되고 있다. 따라서, 본 논문에서는 재해복구시스템의 서비스 전환 자동화를 통해 복구시간 단축 및 시스템 운영의 효율성을 극대화하기 위한 재해복구시스템을 설계, 구축하였다. 논문에서 제안한 방식에 의해 설계, 구축된 재해복구시스템을 적용하여 통합 DR서버 이중화 테스트, 웹서버 이중화 테스트, FC-IP 이중화 테스트 및 SAN 스위치 이중화 테스트를 각각 수행하였다.

• 디자인학연구
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• 제18권1호
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• pp.49-58
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• 2005

기존의 정보이론은 정보의 송신자, 메시지, 채널, 수신자 등을 중심으로 정보전달과정에서 개입될 수 있는 잡음이나 정보의 량, 정보의 선택확률에 대하여 다루었다. 현재의 디지털 정보환경에서는 다양한 정보미디어와 더불어 정보 메시지 자체를 전달하는 것 이외에 정보를 어떻게 전달하는가가 중요한 문제로 대두되었다. 따라서 기존의 정보이론에 대한 다양한 해석이 필요하며, 정보디자인 문제해결을 위한 접근방법의 하나로 정보의 잉여성에 대해 고착해 볼 수 있다. 잉여성은 정보의 부가적 표현이나 중복성을 의미하며 흥미를 유발하고 해석해야 할 정보의 량을 줄여 보다 명확한 정보전달을 한다. 잉여성은 문학과 건축, 미술 등기 예술 커뮤니케이션에서 수용자를 중시하여 참여를 유도함으로써 예술을 완성시키기 위해 활용되는 개념이다. 이는 정보수용자 측면에서 설득적 정보를 디자인하기 위해 활용이 필요하다. 디지털 정보환경에서 정보의 잉여성은 수용자의 체험과 기억을 돕는 것으로, 기술적 요인의 멀티미디어와 인터랙션의 부가적 표현이나 이벤트 개념에 의해 형성될 수 있다. 정보의 구조화 과정에서는 엔터테인먼트적 요소와 스토리텔링 기법을 이용한 놀이의 잉여구조와 엔트로피, 코드의 중층화 등을 통해 정보의 잉여성을 표현할 수 있다. 잉여성은 정보에 대한 흥미를 유발시켜 수용자의 적극적 정보해석 의지를 갖게 함으로써 정보전달목적을 효과적으로 달성할 수 있게 한다.

• Journal of Information Processing Systems
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• 제17권2호
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• pp.318-333
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• 2021

Smartphones are one of the most widely used mobile devices allowing users to communicate with each other. With the development of mobile apps, many companies now provide various services for their customers by studying interactive systems in the form of mobile messengers for business marketing and commercial promotion. Such interactive systems are called "chatbots." In this paper, we propose a method of avoiding the redundant responses of chatbots, according to the utterances entered by the user. In addition, the redundant patterns of chatbot responses are classified into three categories for the first time. In order to verify the proposed method, a chatbot is implemented using Telegram, an open source messenger. By comparing the proposed method with an existent method for each pattern, it is confirmed that the proposed method significantly improves the redundancy avoidance rate. Furthermore, response performance and variation analysis of the proposed method are investigated in our experiment.

• 한국음향학회지
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• 제31권7호
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• pp.427-434
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• 2012

WSOLA 방식은 음성 신호의 시간축 변환을 위한 고음질의 효율적인 알고리즘으로 알려져 있다. WSOLA의 계산량은 두 신호 파형 사이의 유사도를 평가하는 반복적인 정규상호상관도 계산에 집중되어 있다. 본 논문은 WSOLA 계산량 감축을 위해 고속의 정규상호상관도 계산 방법을 제안하며, 제안된 방법에서는 미리 계산된 합 테이블을 통해 인접한 구간에서의 반복적인 정규상호상관도 계산의 중복성을 제거한다. 정규상호상관도의 분모 부분은 시간축 변환 비율에 관계없이 높은 중복성을 가지는데 반해, 분자 부분은 보다 낮은 중복성을 가지며 중복 정도가 시간축 변환 비율과 최적 이동값에 의해 영향을 받기 때문에 고속 계산을 위해 보다 복잡한 알고리즘이 요구된다. 시뮬레이션 결과, 제안된 방법이 기존의 WSOLA와 완전히 동일한 음질을 유지하면서도 시간축 압축의 경우 약 40%, 그리고 1/2배속 및 1/3배속으로의 시간축 신장의 경우 각각 약 47% 및 52%의 실행시간을 감소시킴을 보인다.

• 센서학회지
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• 제22권2호
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• pp.162-173
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• 2013

The purpose of this paper is to classify VOC gases by emulating the characteristics found in biological olfaction. For this purpose, we propose new signal processing method based a polymeric chemical sensor array consisting of 4096 sensors which is created by NEUROCHEM project. To remove unstable sensors generated in the manufacturing process of very large scaled chemical sensor array, we used discrete wavelet transformation and cosine similarity. And, to remove the supernumerary redundancy, we proposed the method of selecting candidates of representative sensor representing sensors with similar features by Fuzzy c-means algorithm. In addition, we proposed an improved algorithm for selecting representative sensors among candidates of representative sensors to better enhance classification ability. However, Classification for very large scaled sensor array has a great deal of time in process of learning because many sensors are used for learning though a redundancy is removed. Throughout experimental trials for classification, we confirmed the proposed method have an outstanding classification ability, at transient state as well as steady state.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.313-316
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• 2000

This paper proposes a new solution by carrier-based SVPWM method to solve the most serious problem of Flying Capacitor Multi-level Inverter that is unbalance of capacitor voltages The voltage unbalance is occurred by the difference of each capacitor's charging and discharging time applied to Flying Capacitor Multi-level Inverter. It controls the variation of capacitor voltages into the mean'0' during some period by means of new carriers using the leg voltage redundancy in the Inverter. The solution can be easily expanded to the multi-level. Also this method can make the switching loss and conduction loss of device equal by the use of leg voltage redundancy. First the unbalance of capacitor voltage is analyzed and the conventional theory of self-balance using phase-shifted carrier is reviewed. And then the new method that is suitable to the Flying Capacitor Inverter is explained. The simulation results would be shown to verify the proposed method