• Title/Summary/Keyword: environment adaptation

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MRAS Based Speed Estimator for Sensorless Vector Control of a Linear Induction Motor with Improved Adaptation Mechanisms

  • Holakooie, Mohammad Hosein;Taheri, Asghar;Sharifian, Mohammad Bagher Bannae
    • Journal of Power Electronics
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    • v.15 no.5
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    • pp.1274-1285
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    • 2015
  • This paper deals with model reference adaptive system (MRAS) speed estimators based on a secondary flux for linear induction motors (LIMs). The operation of these estimators significantly depends on an adaptation mechanism. Fixed-gain PI controller is the most common adaptation mechanism that may fail to estimate the speed correctly in different conditions, such as variation in machine parameters and noisy environment. Two adaptation mechanisms are proposed to improve LIM drive system performance, particularly at very low speed. The first adaptation mechanism is based on fuzzy theory, and the second is obtained from an LIM mechanical model. Compared with a conventional PI controller, the proposed adaptation mechanisms have low sensitivity to both variations of machine parameters and noise. The optimum parameters of adaptation mechanisms are tuned using an offline method through chaotic optimization algorithm (COA) because no design criterion is given to provide these values. The efficiency of MRAS speed estimator is validated by both numerical simulation and real-time hardware-in-the-loop (HIL) implementations. Results indicate that the proposed adaptation mechanisms improve performance of MRAS speed estimator.

Improvement of Recognition Performance for Limabeam Algorithm by using MLLR Adaptation

  • Nguyen, Dinh Cuong;Choi, Suk-Nam;Chung, Hyun-Yeol
    • IEMEK Journal of Embedded Systems and Applications
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    • v.8 no.4
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    • pp.219-225
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    • 2013
  • This paper presents a method using Maximum-Likelihood Linear Regression (MLLR) adaptation to improve recognition performance of Limabeam algorithm for speech recognition using microphone array. From our investigation on Limabeam algorithm, we can see that the performance of filtering optimization depends strongly on the supporting optimal state sequence and this sequence is created by using Viterbi algorithm trained with HMM model. So we propose an approach using MLLR adaptation for the recognition of speech uttered in a new environment to obtain better optimal state sequence that support for the filtering parameters' optimal step. Experimental results show that the system embedded with MLLR adaptation presents the word correct recognition rate 2% higher than that of original calibrate Limabeam and also present 7% higher than that of Delay and Sum algorithm. The best recognition accuracy of 89.4% is obtained when we use 4 microphones with 5 utterances for adaptation.

A Context Adaptation System for Ubiquitous Computing (유비쿼터스 컴퓨팅을 위한 상황 적응 시스템)

  • Oh, Min-Kyung;Chang, Byeong-Mo
    • The KIPS Transactions:PartA
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    • v.14A no.6
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    • pp.363-370
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    • 2007
  • The ubiquitous computing environment could provide better service to users by adapting to changing contexts. In this paper, we developed a context adaptation system, which enables an ubiquitous program to adapt to different contexts, following its adaptation rules. Using this system, programmers can develop ubiquitous programs suitable for changing contexts, by describing the context adaptation policy. The context adaptation engine of this system fits the ubiquitous program to the current context based on the context adaptation rules. This system was implemented using JCAF, context-aware programing framework based on java. A simulator is also provided to simulate ubiquitous programs by changing contexts.

Outlook for a New International Agreement on Climate Change Adaptation: How to Approach (기후변화 적응의 신기후체제 합의: 전망을 위한 접근방법)

  • Lee, Seungjun
    • Journal of Environmental Policy
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    • v.14 no.3
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    • pp.75-94
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    • 2015
  • The purpose of this study is to analyze the major issues discussed among Parties and provide a framework for predicting the agreements on those issues, prior to the final negotiation on a new legally-binding agreement on climate change adaptation in the United Nations Framework Convention on Climate Change (UNFCCC). The analyses of documents, adaptation actions, and work of the Ad Hoc Working Group on the Durban Platform for Enhanced Action (ADP) under the UNFCCC informed that the adaptation issue has primarily been focused on the support of developed country Parties for the adaptation of developing country Parties following the principle of the Convention, Common but Differentiated Responsibilities and Respective Capabilities (CBDR-RC). Three-year work of the ADP acknowledged the major issues on adaptation in the new climate agreement, which would be categorized as long-term and global aspects, commitments/contributions/actions, monitoring and evaluation, institutional arrangements, and loss and damage. A final agreement on each issue could be predicted by setting a zone of possible agreement in-between the two extremes of developing and developed country Parties and considering three major elements affecting the Parties' positions, national priority, adaptation action, and social expectation, which are proposed in this study. The three major elements should be considered in a balanced manner by Parties to draw a durable agreement that will enhance global adaptation actions from a long-term perspective. That is, the agreement needs to reflect adaptation actions occurring outside the Convention as well as social expectations for adaptation. It is expected that the new agreement on climate change adaptation, from a long-term and global perspective, would be an opportunity to reduce vulnerability and build resilience to climate change by incorporating global expectations.

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Reviews on the Adaptation Strategy to Climate Change -Application to the Sea Level Rise- (기후변화 적응방안 연구 -해수면 상승을 중심으로-)

  • Cho Kwangwoo;Maeng Jun-Ho;Kim Hae-Dong;Oh Young Min;Kim Dong-Sun;Kim Mu Chan;Yoon Jong Hwui
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.10 no.2 s.21
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    • pp.81-88
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    • 2004
  • We review the adaptation strategies of the 21st climate change in an application to sea level rise. For the development of appropriate adaptation strategies on the coast vulnerable to the sea level rise, we have to consider the issues such as where to adapt, how to adapt, and when to adapt. The coastal target needed adaptation can be found by the evaluation of adaptive capacity of the coastal zone which requires the understanding of impacts and adaptive potential of the natural and socioeconomic systems in the coastal zone. Planned adaptation options to sea level rise can be classified into three generic approaches as managed retreat, accommodation, and protection In practice, the implementation of the options requires the analysis of land use, degree of vulnerability, cost and benefit, etc, and may be combination of the options rather than one approach. In terms of the response timing, the adaptation can be grouped as anticipatory and reactive ones. Generally it is more effective to consider both anticipatory and reactive adaptations at the same time for the impacts of future sea level rise. Due to the scientific uncertainty of climate change issues including sea level rise, the adaptation processes have to be designed to deal with a series of processes such as information md awareness establishment, planning and design implementation, and monitoring and evaluation in continuity and long-term period.

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A Study on the Success Factors by the Development Stages of e-Business in Korean Enter prises (우리나라 기업의 e-비즈니스 발전단계별 성공요인에 관한 연구)

  • Shin, Hoe-Kyun;Ahn, Cha-Num
    • The Journal of Information Systems
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    • v.14 no.1
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    • pp.67-85
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    • 2005
  • This study is to find out empirically the success factors on the development stages of e-business in Korean enterprises, to formulate e-business strategy and to decide e-business policy. For this purpose, the study reviews the conceptual framework on the success factors for the development stages of e-business and the data is collected from 304 companies implementing e-business. The study is conducted in three ophases an follows; First, according to this study, the development stage of e-business in Korean Enterprises is between 'Information Access Stage' and 'Core Business Transaction Stage'. Second, four factors comsisted of 29 items derived from factor analysis are named as 'Environmental Adaptation','Customer Relationship management','Marketing' and 'Environment of Organization'. Third, the success factors of first stage(Information Access Statge) include 'Marketing' and 'Environmental Adapotation', the success factors of second stage(Electronic Collaboration Stage) include 'Environmental Adaptation' and 'Environment of Organization' and the success factor of third stage(Core Business Transaction Stage) include 'Environment of Organization'. The results of this study show that; 1) the Korean enterprise seems to be in the Electronic Collaboration Stage of e-business development, and 2) the success factors are 'Marketing' for first stage, 'Environmental Adaptation' for second stage, and 'Environment of Organization' for third stage.

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Investigation on Enhancing Efficiency in International Cooperation for Climate Change Adaptation of Republic of Korea (우리나라의 기후변화적응 국제협력에 대한 고찰)

  • Park, Yong-Ha;Chung, Suh-Yong;Son, Yowhan;Lee, Woo-Kyun
    • Journal of Climate Change Research
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    • v.1 no.2
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    • pp.179-188
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    • 2010
  • To cope with various issues in the aspect of climate change adaptation of UNFCCC, Korea began preparing a Five-year National Climate Change Adaptation Plan in 2010 to be implemented from 2011~2015, for the purposes of securing a concrete system to adapt to climate change. Compared with the policies and measurement tools of developed countries, Korea's climate change adaptation capabilities suffers from a number of limitations including insufficiencies of basic information, human resources for research on climate change, and technology in risk and vulnerability assessment. At the same time, Korea maintains superior information technology systems, and comparatively strong climate change adaptation technologies. Recently, with the establishment of the Korea Adaptation Center for Climate Change as a specialized research organization in climate change adaptation, Korea has upgraded its ability to adapt to climate change and to provide support to other Asian countries which are vulnerable to climate change. In consideration of the close relation between climate change adaptation policy and technology development with the environmental industry, Korea's pursuit of cooperation and technical support for developing countries in the Asia region can be seen as the commencement of a long term investment for the nation's future. International cooperation on climate change adaptation between countries in the region can build a mutually complementary and integrated partnership in business, research, education, and other areas. Furthermore, Korea can also participate in the exploration of common issues as landmark projects that can attract global interest with developing countries.

A Research of FS-VDSL Adaptation in Home Network (홈네트워크에서 FS-VDSL 적용방안에 관한 연구)

  • Lee Sang-Jae;Jun Yong-Il;Lee Hyoung-Ho
    • 한국정보통신설비학회:학술대회논문집
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    • 2003.08a
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    • pp.349-352
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    • 2003
  • In this paper, we introduce the concept, architecture, and service areas of FS-VDSL specification. We mainly focused on FS-VDSL CPE architecture, which consists of two different types, concentrated architecture and distributed one. We also provide the possibility of CPE adaptation in domestic in-home environment. As a result of our study, distributed CPE architecture is a better candidate to our in-home environment. Another important point of consideration in FS-VDSL adaptation in Korea is the protocol stack of FS-VDSL. Recently, Ethernet-based VDSL technology is more populated than ATM-based VDSL, which is originally adopted in FS-VDSL specification. So, we must deeply think about the modification of protocol stack of FS-VDSL when deploying it in Korea.

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A Study on the Adaptation of Regulation in the Leasure Safety Law (수상레저안전법상의 규제순응도에 관한 조사 연구)

  • 문범식;국승기;나호수;하해동
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.8 no.2
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    • pp.1-8
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    • 2002
  • Government is willing to abolish half of whole administration regulations and put emphasis to improve them. There was criticism that taper by bureaucracies' form and interest group's repulsion does not reach here upon in spite of these result. Therefore, need to ready diversified regulation adaptation administration countermeasure so that can observe because propel regulation innovation until now continuously and people, corporation, public official understand definitely contents of regulation. Contents of question regulation awareness about regulation adaptation and degree. On the basis of Question investigation about persons concerned of leisure safety law and wish to grasp observance degree, and produce synthetic Contents and field conformity degree, and draw solution plan of reformable item in leisure safety law and present development direction of leisure safety law.

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A Design and Implementation of Context Information Gathering System for Contents Adaptation Service (콘텐츠 적응화 서비스를 위한 상황정보 수집 시스템의 설계 및 구현)

  • Jun, Wu-Rak;So, Soo-Hwan;Lee, Jae-Dong
    • Journal of Korea Society of Industrial Information Systems
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    • v.14 no.2
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    • pp.1-7
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    • 2009
  • This paper proposes a context gathering system that obtains user's environment information from sensor and generates user's context profile. To design the system, we classify context and design context model based on traditional context-aware computing. The proposed system supports contexts adaptation service by gathering user's environment characteristics and biological characteristics and generating user profile.