• Title/Summary/Keyword: interface states

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Development of open MMI system for integration of business computers and process computers (포항제철소 B/C-P/C 통합을 위한 개방형 MMI 개발)

  • 추영열;김경백;황화원;김영일
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.684-687
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    • 1997
  • In order to access to the Business Computer (B/C), the Process Computer(P/C), and the Database Server in one terminal, the Open Man Machine Interface (MMI) System has been developed. The testbed to develop the interface functions for B/C, P/C, DB server, and CCD camera were constructed, which consisted of Workstations and Personal Computers (PC). Graphic display programs Monitoring the process states of Tandem Cold Mill plant were developed using four Graphic User Interface tools: InTouch, FIX32, Open Interface Environment, and ILOG Views. With regard to the CPU utilization and response delay required to open new display, the performance tests have been carried out on each MMI platform.

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Reactive Reserve based Contingency Constrained Optimal Power Flow to Enhance Interface Flow Limits in Terms of Voltage Stability

  • Hwachang Song;Lee, Byongjun
    • KIEE International Transactions on Power Engineering
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    • v.11 no.X00
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    • pp.27-32
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    • 2001
  • This paper presents a concept of reactive reserve based contingency constrained optimal power flow (RCCOPF). RCCOPF for enhancement of interface flow limit is composed of two modules, which are the modified continuation power flow (MCPF) and reactive optimal power flow (ROPF). In RCCOPF, two modules are repeatedly performed to increase interface flow margins of selected contingent states until satisfying the required enhancement of interface flow limit. In numerical simulation, a simple example with New England 39-bus test system is shown.

An interface element for modelling the onset and growth of mixed-mode cracking in aluminium and fibre metal laminates

  • Hashagen, Frank;de Borst, Rene
    • Structural Engineering and Mechanics
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    • v.5 no.6
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    • pp.817-837
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    • 1997
  • In the present contribution an interface crack model is introduced which is capable of modelling crack initialisation and growth in aluminium as well as in Fibre Metal Laminates. Interface elements are inserted in a finite element mesh with a yield function which bounds all states of stress in the interface. Hardening occurs after a state of stress exceeds the yield stress of the material. The hardening branch is bounded by the ultimate stress of the material. Thereafter, the state of stress is reduced to zero while the inelastic deformations grow. The energy dissipated by the inelastic deformations in this process equals the fracture energy of the material. The model is applied to calculate the onset and growth of cracking in centre cracked plates made of aluminium and GLARE$^{(R)}$. The impact of the model parameters on the performance of the crack model is studied by comparisons of the numerical results with experimental data.

Bearing capacity of foundation on rock mass depending on footing shape and interface roughness

  • Alencar, Ana S.;Galindo, Ruben A.;Melentijevic, Svetlana
    • Geomechanics and Engineering
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    • v.18 no.4
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    • pp.391-406
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    • 2019
  • The aim of this paper was to study the influence of the footing shape and the effect of the roughness of the foundation base on the bearing capacity of shallow foundations on rock masses. For this purpose the finite difference method was used to analyze the bearing capacity of various types and states of rock masses under the assumption of Hoek-Brown failure criterion, for both plane strain and axisymmetric model, and considering smooth and rough interface. The results were analyzed based on a sensitivity study of four varying parameters: foundation width, rock material constant (mo), uniaxial compressive strength and geological strength index. Knowing how each parameter influences the bearing capacity depending on the footing shape (circular vs strip footing) and the footing base interface roughness (smooth vs rough), two correlation factors were developed to estimate the percentage increase of the ultimate bearing capacity as a function of the footing shape and the roughness of the footing base interface.

Characterization of Electrical Properties of Si Nanocrystals Embedded in a SiO$_{2}$ Layer by Scanning Probe Microscopy (Scanning Probe Microscopy를 이용한 국소영역에서의 실리콘 나노크리스탈의 전기적 특성 분석)

  • Kim, Jung-Min;Her, Hyun-Jung;Kang, Chi-Jung;Kim, Yong-Sang
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.10
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    • pp.438-442
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    • 2005
  • Si nanocrystal (Si NC) memory device has several advantages such as better retention, lower operating voltage, reduced punch-through and consequently a smaller cell area, suppressed leakage current. However, the physical and electrical reasons for this behavior are not completely understood but could be related to interface states of Si NCs. In order to find out this effect, we characterized electrical properties of Si NCs embedded in a SiO$_{2}$ layer by scanning probe microscopy (SPM). The Si NCs were generated by the laser ablation method with compressed Si powder and followed by a sharpening oxidation. In this step Si NCs are capped with a thin oxide layer with the thickness of 1$\~$2 nm for isolation and the size control. The size of 51 NCs is in the range of 10$\~$50 m and the density around 10$^{11}$/cm$^{2}$ It also affects the interface states of Si NCs, resulting in the change of electrical properties. Using a conducting tip, the charge was injected directly into each Si NC, and the image contrast change and dC/dV curve shift due to the trapped charges were monitored. The results were compared with C-V characteristics of the conventional MOS capacitor structure.

A study of tunnel concrete lining design using the ground-lining interaction model with the interface element (계면요소를 이용한 지반-라이닝 상호작용 모델에 의한 터널 콘크리트 라이닝 연구)

  • Huh, Do-hak;Moon, Hyun-Koo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.6
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    • pp.575-586
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    • 2015
  • In NATM tunnel, the Ground-Lining Interaction model(GLI model) had been proposed a one of the numerical analysis as the ground load estimation method of the concrete lining. But this model was not applied with the interface mechanism between the ground and the support member or concrete lining. Therefor in this study, it is implemented as a model for closer than actual states that the interface element applied to the existing GLI model. And the modified GLI formula is proposed with the ground load estimation that is from the numerical results for each ground and rock cover conditions. Based on the numerical results, the ground load acting on concrete lining is reduced to ave. 88~106% in case of IV ground condition and ave. 47~57% in case of weathered soil condition comparing with the existing GLI model. It can be anticipated that the results obtained from this study can be applied to an estimation of the ground load on the concrete lining modeled like as real states, consistent and economical design.

Analysis on Current States of Multimedia Interface Design Research (멀티미디어 인터페이스 디자인의 연구 경향 분석)

  • 정승녕;정경원
    • Archives of design research
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    • v.12 no.2
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    • pp.171-182
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    • 1999
  • This study aims to clarify the nature and properties of multimedia interface design, and to identify direction of multimedia interface design research. It also focuses on forecasting boundaries and major trends in current researches on multimedia interface design. The two jargons, 'interface' and 'interaction', are distinguished clearly to show the definition and boundary of multimedia interface. The multidisciplinary nature of multimedia interface design is identified as a result of examination and analysis on major researches. Nine research cases have been selected and categorized into two directions as the theoretical approach and the technical approach. Major characteristics of each case are examined in terms of subjects and methodologies. Findings on current states of the multimedia interface design research are: $\circled1$increasing importance of contextuality; $\circled2$emerging tendency for perceiving the content as one of interacting subjects; $\circled3$providing idiomatic interface context; and $\circled4$paying much attention to the meaning of minor actions. Those findings can be possible as a result of expansion of boundary of multimedia content with rapid distribution of multimedia in recent years. The study concludes that further researches can be activated on the basis of the concept of content-based multimedia interface.

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Classification of Mental States Based on Spatiospectral Patterns of Brain Electrical Activity

  • Hwang, Han-Jeong;Lim, Jeong-Hwan;Im, Chang-Hwan
    • Journal of Biomedical Engineering Research
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    • v.33 no.1
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    • pp.15-24
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    • 2012
  • Classification of human thought is an emerging research field that may allow us to understand human brain functions and further develop advanced brain-computer interface (BCI) systems. In the present study, we introduce a new approach to classify various mental states from noninvasive electrophysiological recordings of human brain activity. We utilized the full spatial and spectral information contained in the electroencephalography (EEG) signals recorded while a subject is performing a specific mental task. For this, the EEG data were converted into a 2D spatiospectral pattern map, of which each element was filled with 1, 0, and -1 reflecting the degrees of event-related synchronization (ERS) and event-related desynchronization (ERD). We evaluated the similarity between a current (input) 2D pattern map and the template pattern maps (database), by taking the inner-product of pattern matrices. Then, the current 2D pattern map was assigned to a class that demonstrated the highest similarity value. For the verification of our approach, eight participants took part in the present study; their EEG data were recorded while they performed four different cognitive imagery tasks. Consistent ERS/ERD patterns were observed more frequently between trials in the same class than those in different classes, indicating that these spatiospectral pattern maps could be used to classify different mental states. The classification accuracy was evaluated for each participant from both the proposed approach and a conventional mental state classification method based on the inter-hemispheric spectral power asymmetry, using the leave-one-out cross-validation (LOOCV). An average accuracy of 68.13% (${\pm}9.64%$) was attained for the proposed method; whereas an average accuracy of 57% (${\pm}5.68%$) was attained for the conventional method (significance was assessed by the one-tail paired $t$-test, $p$ < 0.01), showing that the proposed simple classification approach might be one of the promising methods in discriminating various mental states.

Reactive Reserve Based Contingency Constrained Optimal Power Flow for Enhancement of Voltage Stability Margins (전압안정도 여유 향상을 위한 무효예비력 기반 상정사고 제약 최적조류계산)

  • Song, Hwa-Chang;Lee, Byong-Jun;Kwon, Sae-Hyuk;Ajjarapu, Venkataramana
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.19-23
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    • 2003
  • This paper presents a new concept of reactive reserve based contingency constrained optimal power flow (RCCOPF) for voltage stability enhancement. This concept is based on the fact that increase in reactive reserves is effective for enhancement of voltage stability margins of post-contingent states, in this paper, the proposed algorithm is applied to voltage stability margin of interface flow. Interface flow limit, in the open access environment, can be a main drawback. RCCOPF for enhancement of interface flow margin is composed of two modules, modified continuation power flow (MCPF) and optimal power flow (OPF). These modules art recursively perform ed until satisfying the required margin of interface flow in the given voltage stability criteria.

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Surface and Interface Magnetism in CoTi/FeTi/CoTi(110)

  • Lee G.H.;Jin Y. J.;Lee J. I.;Hong S.C.
    • Journal of Magnetics
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    • v.10 no.1
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    • pp.1-4
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    • 2005
  • We investigated the electronic structures and the magnetic properties of Ti-based intermetallic system of CoTi/FeTi/CoTi(110) surface and interface by using the all-electron full potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation (GGA). The calculated magnetic moments of interface Co and Fe atoms are 0.65 and 0.15 μ/sub B/, respectively. Surface and interface magnetism of CoTi/FeTi/CoTi(110) are discussed using the calculated density of states (DOS) and the spin densities.