• 제목/요약/키워드: Zone-Based Evaluation

검색결과 326건 처리시간 0.027초

New approach of using cortico-cortical evoked potential for functional brain evaluation

  • Jo, Hyunjin;Kim, Dongyeop;Song, Jooyeon;Seo, Dae-Won
    • Annals of Clinical Neurophysiology
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    • 제23권2호
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    • pp.69-81
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    • 2021
  • Cortico-cortical evoked potential (CCEP) mapping is a rapidly developing method for visualizing the brain network and estimating cortical excitability. The CCEP comprises the early N1 component the occurs at 10-30 ms poststimulation, indicating anatomic connectivity, and the late N2 component that appears at < 200 ms poststimulation, suggesting long-lasting effective connectivity. A later component at 200-1,000 ms poststimulation can also appear as a delayed response in some studied areas. Such delayed responses occur in areas with changed excitability, such as an epileptogenic zone. CCEP mapping has been used to examine the brain connections causally in functional systems such as the language, auditory, and visual systems as well as in anatomic regions including the frontoparietal neocortices and hippocampal limbic areas. Task-based CCEPs can be used to measure behavior. In addition to evaluations of the brain connectome, single-pulse electrical stimulation (SPES) can reflect cortical excitability, and so it could be used to predict a seizure onset zone. CCEP brain mapping and SPES investigations could be applied both extraoperatively and intraoperatively. These underused electrophysiologic tools in basic and clinical neuroscience might be powerful methods for providing insight into measures of brain connectivity and dynamics. Analyses of CCEPs might enable us to identify causal relationships between brain areas during cortical processing, and to develop a new paradigm of effective therapeutic neuromodulation in the future.

동전을 이용한 제조사 별 디지털 방사선 영상 시스템의 자동노출제어 성능 평가 (Automatic Exposure Control Performance Evaluation of Digital Radiographic Imaging System by Manufacturer Using Coins)

  • 임세훈;성열훈
    • 대한방사선기술학회지:방사선기술과학
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    • 제45권1호
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    • pp.1-9
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    • 2022
  • In this study, we proposed an image quality control for an automatic exposure control (AEC) of digital radiographic imaging system and tried to analyze the performance of the AEC by various manufacturer. The subjects of the experiment were analyzed for the AEC image quality evaluation using digital radiation generators from four manufacturer such as PHILIPS, GE Healthcare, SAMSUNG Healthcare, DK Medical Solution. We used as materials for the implementation of the image quality evaluation by coins (500 won, KOMSCO, Korea). This study evaluated the performance evaluation of the AEC as image quality and exposure dose (Milliampere-seconds; mAs). The image quality evaluation was tried visual assessment by two radiologic technologists and contrast to noise (CNR) by ImageJ. The exposure dose investigated mAs on digital radiation generators. The radiographic coin images acquired 360 images based on change in the control factors of the AEC, which were kVp, the consistency of field configuration and dominant zone, sensitivity and density. As a result, there was a significant difference in the AEC performance between manufacturer. The CNR by the AEC for each manufacturer showed a difference of up to about 1.9 times. The exposed tube current by the AEC for each manufacturer showed a difference of up to about 5.8 times. It is expected that our proposed evaluation method using coins could be applied as the AEC performance evaluation method in the future.

ICE GROSS HEAT RELEASE STRONGLY INFLUENCED BY SPECIFIC HEAT RATIO VALVES

  • Lanzafame, R.;Messina, M.
    • International Journal of Automotive Technology
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    • 제4권3호
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    • pp.125-133
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    • 2003
  • Several models for the evaluation of Gross Heat Release from the internel combustion engine (ICE) are often used in literature. One of these is the First Law - Single Zone Model (FL-SZM), derived from the First Law of Thermodynamic. This model present a twice advantage: first it describes with accuracy the physic of the phenomenon (charge heat release during the combustion stroke and heat exchange between gas and cylinder wall); second it hat a great simplicity in the mathematical formulation. The evaluation of Heat Release with the FL-SZM is based on pressure experimental measurements inside the cylinder, and ell the assumption of several parameters as the specific heat ratio, wall temperature, polytropic exponent for the motored cycle evaluation, and many others. In this paper the influence of gases thermodynamic properties on Cross Heat Release has been esteemed. In particular the influence of an appropriate equation for k=k(T) (specific heat ratio vs. temperature) which describes the variations of gases thermodynamic properties with the mean temperature inside the cylinder has been evaluated. This equation has been calculated by new V order Logarithmic Polynomials (VoLP), fitting experimental gases properties through the least square methods.

오차확률 기반 송전계통 보호계전기 보호도 평가방법 연구 (Protectability Evaluation of Distance Relay based on a Probabilistic Method for Transmission Network)

  • 짱원하오;최면승;이승재
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.286_287
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    • 2009
  • In this paper, the protectability of distance relay is furtherly researched. Based on the probabilistic modeling of the measurement errors, the protectability of three zones is presented in detail by considering their different protection aims denoted by sensitivity and selectivity. The optimal setting for the each zone can be obtained to provide a reference for the practical application.

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효율적인 멀티미디어 콘텐츠 공유를 위한 CAN 기반 P2P 네트워킹 (P2P Networking based on CAN for Effective Multimedia Contents Sharing)

  • 박찬모;김종원
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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    • pp.259-262
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    • 2003
  • A efficient P2P (peer to peer) networking for sharing multimedia contents is proposed to overcome the limitations of unstructured approaches. The proposed approach is attempting to organize the participating P2P nodes by modifying a n-dimensional cartesian-coordinate space DHT (distributed hash table), CAN (content addressable network). The network identifiers (e.g., network prefix of IP address) of participating nodes are mapped into the CAN virtual coordinate space (in 2-d) and nodes with similar identifiers are grouped into the same zone. The proposed scheme is expected to show some level of concentration reflecting the network identifiers. Network simulator-based evaluation is performed to verify the effectiveness of the proposed scheme.

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Evaluation of Residual Stresses in 12%-Cr Steel Friction Stir Welds by the Eigenstrain Reconstruction Method

  • Jun, Tea-Sung;Korsunsky, Alexander M.
    • 한국생산제조학회지
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    • 제24권1호
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    • pp.15-22
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    • 2015
  • In the present paper we report the results of a study into Friction Stir Welds (FSWs) made in 13 mm-thick 12%-Cr steel plates. Based on residual strains obtained by diffraction techniques, eigenstrain analysis was performed using the Eigenstrain Reconstruction Method (ERM), which is a novel methodology for the reconstruction of full-field residual strain and stress distributions within engineering components. Significant eigenstrain distributions were found at around Thermo-Mechanically Affected Zone (TMAZ) where the most severe plastic deformation was occurred. Microstructure analysis was used to elucidate this phenomenon showing that the grain structure in TMAZ was bent and not successfully recrystallised, resulting in severe deformation behaviour. The reconstructed residual strain distributions by the ERM agree well with the experimental results. It was found that the approach based on theory of eigenstrain is a powerful basis for reconstructing the full-field residual strain/stress distributions in engineering components and structures.

용접잔류응력장에서 피로균열의 전파에 따른 잔류응력 재분포에 대한 해석적 평가 (An Evaluation of Residual Stress Redistribution in the Welding Residual Stress Field Caused by Fatigue Crack Propagation by Finite Element Method)

  • 박응준;김응준
    • Journal of Welding and Joining
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    • 제26권6호
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    • pp.92-96
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    • 2008
  • An investigation was performed to predict residual stress redistribution for the crack propagation initially through tensile residual stress field. The analytical method, which is based on Dugdale model by finite element analysis using elastic analysis method considering the superposition principle, was proposed to estimate the redistribution of residual stress caused by crack propagation. The various aspect of distribution of residual stress caused by crack propagation was examined based on the configuration change of specimen. The analysis results show that the aspect of redistribution of residual stress caused by crack propagation depends on the width of the specimen provided that the initial distribution of residual stress is identical.

동일한 지진구역에 위치한 건축 구조물의 내진거동을 기초로한 기존 내진설계 평가 (Evaluation of the Current Seismic Design Procedures Based on the Seismic Performance of the Building Located in the Same Seismic Area)

  • 한상환;이리형
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 봄 학술발표회 논문집
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    • pp.160-166
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    • 1997
  • Current Seismic Design Procedure has been developed and improved mostly based on the experiences of the past earthquakes. Many engineers and researchers believe that the seismic codes and provisions are adequate for the basic objective of the code which is "life-safe". However they doubt the performance of the structure during the earthquake. The seismic code seems the black box for the designers which means it is not transparent since the designer can not predict the level of the damage of the structure under future earthquakes. This purpose of this study is to check the validity of the current seismic design procedures. Two structures with different heights are designed and their seismic performances are evaluated for this purpose. Both structures are assumed to be located at the same strong seismic zone.

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SPOT-5 HRG 스테레오 영상으로부터 지형정보 추출 (Extracting Topographic Information from SPOT-5 HRG Stereo Images)

  • 이진덕;이성순;정태식
    • 대한공간정보학회지
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    • 제14권4호통권38호
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    • pp.61-70
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    • 2006
  • 본 논문에서는 SPOT 5호 HRG 스테레오 영상을 이용하여 수치표고모형을 생성하기 위한 사진측량학적 처리과정을 제시하고 수치표고모형 생성을 위한 HRG supermode 영상의 정확도 잠재성을 평가하고자 하였다. 센서모델링을 위하여 광속조정을 행한 후 에피폴라 영상재배열과 영상정합 과정 등을 통하여 수치표면모형을 생성하였다. HRG 영상으로부터 추출된 DEM 성과를 축척 1:5000의 수치지형도로부터 추출된 기준 DEM과 여러 시험구간 상에서 비교하였다. 전체구간 중 5m 미만의 DEM 오차를 나타내는 부분의 비율은 53.8%이었고, 5m를 초과하는 오차부분은 구름, 수역, 건물 등에 의한 영향을 받는 것으로 확인되어 이러한 지역을 제외하고 평가한 정확도는 약 2.5m의 RMSE를 나타내었다. 아울러 추출된 수치표면모형(DSM)을 사용하여 3차원 건물모델과 대상지역 전체의 3차원 가시화 모델을 작성하였다.

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경관단위분류를 통한 경관가치평가 및 경관계획적 활용 (Landscape Assessment and Landscape Planning based on Landscapetope Classification)

  • 권오성;이현택;나정화;조현주
    • 한국환경복원기술학회지
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    • 제17권1호
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    • pp.65-79
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    • 2014
  • This study selected Nakdong River basin zone in Daegu as an example area to conduct landscapetope classification and aesthetic value assessment of landscape according to the classified landscapetope. The main result of this research can be summed up as following. First, the result of landscapetope type classification showed 28 types of landscapetope including complex residential area (AA), natural stream type with copious vegetation (BA), forest type centered on mixed forest of soft and hardwood (EB) along with 129 types of imputed specific landscapetope. The result of the total first assessment using B-VAT showed the first grade 10 types, II grade 4 types, III grade6 types, IV grade 3 types, 5 types for V grade with the lowest value. The second assessment conducted toward the landscapetope types with the grade higher than the average (including III grade) in the result of the first assessment showed that there are 66 spaces for the sites (1a, 1b) with special meaning for aesthetic landscape evaluation. And also, there were 69 spaces for those (2a, 2b, 2c) with meaning for aesthetic landscape evaluation. The design model of this research is largely divided into improvement goal and specific execution plan. First, the improvement goal is divided into 6 categories including conservation area, complementary area, and restoration area, and the specific execution plan is divided into 14 categories including special landscape management area, general landscape management area, conservation of hill areas with optically good condition. A comprehensive master plan was suggested by directly applying the set landscape planning model to the subject place of this research.