• 제목/요약/키워드: knowledge variation

검색결과 320건 처리시간 0.029초

Stable Intelligent Control of Chaotic Systems via Wavelet Neural Network

  • Choi, Jong-Tae;Choi, Yoon-Ho;Park, Jin-Bae
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.316-321
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    • 2003
  • This paper presents a design method of the wavelet neural network based controller using direct adaptive control method to deal with a stable intelligent control of chaotic systems. The various uncertainties, such as mechanical parametric variation, external disturbance, and unstructured uncertainty influence the control performance. However, the conventional control methods such as optimal control, adaptive control and robust control may not be feasible when an explicit, faithful mathematical model cannot be constructed. Therefore, an intelligent control system that is an on-line trained WNN controller based on direct adaptive control method with adaptive learning rates is proposed to control chaotic nonlinear systems whose mathematical models are not available. The adaptive learning rates are derived in the sense of discrete-type Lyapunov stability theorem, so that the convergence of the tracking error can be guaranteed in the closed-loop system. In the whole design process, the strict constrained conditions and prior knowledge of the controlled plant are not necessary due to the powerful learning ability of the proposed intelligent control system. The gradient-descent method is used for training a wavelet neural network controller of chaotic systems. Finally, the effectiveness and feasibility of the proposed control method is demonstrated with application to the chaotic systems.

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Factors Affecting the Intention to Apply Management Accounting in Enterprises in Vietnam

  • NGUYEN, Hung Quoc;LE, Oanh Thi Tu
    • The Journal of Asian Finance, Economics and Business
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    • 제7권6호
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    • pp.95-107
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    • 2020
  • By applying behavioral intention theories and the theory of diffusion of innovation in organizations, this study identified several factors influencing the intention to apply management accounting in enterprises in Vietnam. Research data was collected from the questionnaire sent to Vietnamese enterprises in 2019, collecting 542 observations from accountants and directors. The data is, then, synthesized by excel file, conformity check, and processed by SPSS 20 software with descriptive statistics and multiple regression analysis. The results showed four factors that affect the intention to apply management accounting in enterprises in Vietnam: (1) Performance expectancy; (2) Effort expectancy; (3) Perceived trust; and (4) Subjective norms. The study pointed out that the above factors explain 60.618% of the variation of "intention to apply management accounting", in which, Subjective norms has the strongest impact (regression coefficient is 0.238). The findings also show that raising the awareness of managers and accountants about the role of management accounting, improving the qualifications and knowledge of accountants, and increasing the trust of managers about management accounting information are needed to increase the level of management accounting application in Vietnamese enterprises. The study also proposes recommendations to improve the effectiveness of management accounting for managers in operation and decision-making.

한국 전통공간디자인의 고고학적 접근에 관한 연구 - 푸코의 고고학적 언표를 중심으로 - (A Study on the Archaeological Approach in Korean Traditional Space Design - Focusing on the Archaeological Statement of Foucault -)

  • 박경애;박영목
    • 한국실내디자인학회논문집
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    • 제19권2호
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    • pp.99-106
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    • 2010
  • This study is about Foucault's conceptual and methodological relevance for structural analysis of Korean traditional space design history. By Foucault's Theory, regionalism is product of the instrumentality of space, power, knowledge and provide the basis for making the operation of power both spatial and temporal. The purpose of this study is to establish topographical map of historical progress and to shed new light on the forming of identity in Korean traditional space design on the poststructural-archaeological aspect. The process of this study is illustrated as follows: At first, it suggests Foucault's 'Theory of archaeology'. It mentions 'historical apriori' and archive, collateral space and general grammar as theoretical background of archaeological logic. Secondly, it clarifies 'statements' depending on the conditions that is 'episteme' in which they emerge and exist within a field of discourse. And it discuss Korean traditional space design concept as a social product on the situated character of interaction in time-space. Finally, it studies genetic variation process of Korean traditional space design based on the social progress in Korean society. And it analyses practical actions of 'Statements' in terms of general grammar and textuality.

경추에 발생한 척삭종의 세침흡인 세포학적 소견 - 1예 보고 - (Fine Needle Aspiration Cytology of Cervical Chordoma - A Case Report -)

  • 양경무;조미연;정순희;봉정표
    • 대한세포병리학회지
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    • 제8권1호
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    • pp.93-97
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    • 1997
  • A case of cervical chordoma diagnosed by fine needle aspiration is discussed. A 41year-old male was admitted due to dyspnea on neck flexion. Radiologic image revealed a retrotracheal superior mediastinal solid mass. Aspiration cytology showed many clusters of oval or large polygonal cells having abundant eosinophilic or bubbly cytoplasm in an amorphous blue-gray mucoid background. The nuclei were round and showed size variation, coarse granular chromatin, and indistinct nucleoli. Some cells contained brown granular pigments in the cytoplasm. Mitoses were rarely found. The cytoplasm was strongly positive for PAS stain. Immunohistochemical stains using cell block revealed positive reaction for cytokerain, EMA, vimentin, and S-100 protein. The confirmative diagnosis was made by following excisional biopsy. Electron microscopic study revealed large pools of intracytoplasmic glycogen and microfilaments. This is the first case of cervical chordoma diagnosed by aspiration cytology to our knowledge in Korean literature.

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High Performance Millimeter-Wave Image Reject Low-Noise Amplifier Using Inter-stage Tunable Resonators

  • Kim, Jihoon;Kwon, Youngwoo
    • ETRI Journal
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    • 제36권3호
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    • pp.510-513
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    • 2014
  • A Q-band pHEMT image-rejection low-noise amplifier (IR-LNA) is presented using inter-stage tunable resonators. The inter-stage L-C resonators can maximize an image rejection by functioning as inter-stage matching circuits at an operating frequency ($F_{OP}$) and short circuits at an image frequency ($F_{IM}$). In addition, it also brings more wideband image rejection than conventional notch filters. Moreover, tunable varactors in L-C resonators not only compensate for the mismatch of an image frequency induced by the process variation or model error but can also change the image frequency according to a required RF frequency. The implemented pHEMT IR-LNA shows 54.3 dB maximum image rejection ratio (IRR). By changing the varactor bias, the image frequency shifts from 27 GHz to 37 GHz with over 40 dB IRR, a 19.1 dB to 17.6 dB peak gain, and 3.2 dB to 4.3 dB noise figure. To the best of the authors' knowledge, it shows the highest IRR and $F_{IM}/F_{OP}$ of the reported millimeter/quasi-millimeter wave IR-LNAs.

Identification and Molecular Characterization of PERV Gamma1 Long Terminal Repeats

  • Huh, Jae-Won;Kim, Dae-Soo;Ha, Hong-Seok;Ahn, Kung;Chang, Kyu-Tae;Cho, Byung-Wook;Kim, Heui-Soo
    • Molecules and Cells
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    • 제27권1호
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    • pp.119-123
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    • 2009
  • Porcine endogenous retroviruses (PERVs) gamma1 in the pig genome have the potential to act as harmful factors in xenotransplantation (pig-to-human). Long terminal repeats (LTRs) are known to be strong promoter elements that could control the transcription activity of PERV elements and the adjacent functional genes. To investigate the transcribed PERV gamma1 LTR elements in pig tissues, bioinformatic and experimental approaches were conducted. Using RT-PCR amplification and sequencing approaches, 69 different transcribed LTR elements were identified. And 69 LTR elements could be divided into six groups (15 subgroups) by internal variation including tandem repeated sequences, insertion and deletion (INDEL). Remarkably, all internal variations were indentified in U3 region of LTR elements. Taken together, the identification and characterization of various PERV LTR transcripts allow us to extend our knowledge of PERV and its transcriptional study.

THE EFFECT OF SURFACE METEOROLOGICAL MEASUREMENTS ON PRECISION GPS HEIGHT DETERMINATION

  • Wang Chuan-Sheng;Liou Yuei-An;Wang Cheng-Gi
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.178-181
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    • 2005
  • The positioning accuracy of the Global Positioning System (GPS) has been improved considerably during the past two decades. The main error sources such as ionospheric refraction, orbital uncertainty, antenna phase center variation, signal multipath, and tropospheric delay have been reduced substantially, if not eliminated. In this study, the GPS data collected by the GPS receivers that were established as continuously operating reference stations by International GNSS Service (IGS), Ministry of the Interior (MOl), Central Weather Bureau (CWB), and Industrial Technology Research Institute (ITRI) Of Taiwan are utilized to investigate the impact of atmospheric water vapor on GPS positioning determination. The surface meteorological measurements that were concurrently acquired by instruments co-located with the GPS receivers include temperature, pressure and humidity data. To obtain the influence of the GPS height on the proposed impact study. A hydrodynamic ocean tide model (GOTOO.2 model) and solid earth tide were used to improve the GPS height. The surface meteorological data (pressure, temperature and humidity) were introduced to the data processing with 24 troposphere parameters. The results from the studies associated with different GPS height were compared for the cases with and without a priori knowledge of surface meteorological measurements. The finding based on the measurements in 2003 is that the surface meteorological measurements have an impact on the GPS height. The associated daily maximum of the differences is 1.07 cm for the KDNM station. The impact is reduced due to smoothing when the average of the GPS height for the whole year is considered.

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USING TRMM SATELLITE C BAND DATA TO RETRIEVE SOIL MOISTURE ON THE TffiETAN PLATEAU

  • Chang Tzu-Yin;Liou Yuei-An
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.737-740
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    • 2005
  • Soil moisture, through its dominance in the exchange of energy and moisture between the land and atmosphere, plays a crucial role in influencing atmospheric circulation. To identify the crucial role, it is a common agreement that knowledge of land surface processes and development of remote sensing techniques are of great important scientific issues. This research uses TRMM satellite C band (10.65 GHz) data to retrieve soil moisture on the Tibetan Plateau in Mainland China. Two retrieval schemes that are implemented include the t-(J) model and the R model. The latter one is developed based on a land surface process and radiobrightness (R) model for bare soil and vegetated terrain. Compared with the in situ ground measurements, the soil moisture retrieved from the R model and the t-(J) model with vegetation information obviously appear more accurate than that derived from bare soil model. Retrieved soil moisture contents from the two inversion models, R model and t-(J) model, have a similar trend, but the former appears to be superior in terms of correlation coefficient and bias compared with in situ data. In the future, we will apply the R model with the TRMM 10.65 GHz brightness temperature to monitor long-term soil moisture variation over Tibet Plateau.

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An Example-Based Engligh Learing Environment for Writing

  • Miyoshi, Yasuo;Ochi, Youji;Okamoto, Ryo;Yano, Yoneo
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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    • pp.292-297
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    • 2001
  • In writing learning as a second/foreign language, a learner has to acquire not only lexical and syntactical knowledge but also the skills to choose suitable words for content which s/he is interested in. A learning system should extrapolate learner\\`s intention and give example phrases that concern with the content in order to support this on the system. However, a learner cannot always represent a content of his/her desired phrase as inputs to the system. Therefore, the system should be equipped with a diagnosis function for learner\\`s intention. Additionally, a system also should be equipped with an analysis function to score similarity between learner\\`s intention and phrases which is stored in the system on both syntactic and idiomatic level in order to present appropriate example phrases to a learner. In this paper, we propose architecture of an interactive support method for English writing learning which is based an analogical search technique of sample phrases from corpora. Our system can show a candidate of variation/next phrases to write and an analogous sentence that a learner wants to represents from corpora.

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유성음과 무성음의 경계를 이용한 연속 음성의 세그먼테이션 (Segmentation of continuous Korean Speech Based on Boundaries of Voiced and Unvoiced Sounds)

  • 유강주;신욱근
    • 한국정보처리학회논문지
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    • 제7권7호
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    • pp.2246-2253
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    • 2000
  • In this paper, we show that one can enhance the performance of blind segmentation of phoneme boundaries by adopting the knowledge of Korean syllabic structure and the regions of voiced/unvoiced sounds. eh proposed method consists of three processes : the process to extract candidate phoneme boundaries, the process to detect boundaries of voiced/unvoiced sounds, and the process to select final phoneme boundaries. The candidate phoneme boudaries are extracted by clustering method based on similarity between two adjacent clusters. The employed similarity measure in this a process is the ratio of the probability density of adjacent clusters. To detect he boundaries of voiced/unvoiced sounds, we first compute the power density spectrum of speech signal in 0∼400 Hz frequency band. Then the points where this paper density spectrum variation is greater than the threshold are chosen as the boundaries of voiced/unvoiced sounds. The final phoneme boundaries consist of all the candidate phoneme boundaries in voiced region and limited number of candidate phoneme boundaries in unvoiced region. The experimental result showed about 40% decrease of insertion rate compared to the blind segmentation method we adopted.

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