• 제목/요약/키워드: SLICE

검색결과 977건 처리시간 0.036초

흰쥐 해마절편에서의 간질발작 및 간질모델 (Seizure and Epilepsy Models on Hippocampal Slices of Rats)

  • 권오영
    • Annals of Clinical Neurophysiology
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    • 제1권2호
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    • pp.147-153
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    • 1999
  • Hippocampal slice models can be a powerful tool to study the mechanism of partial epilepsy. Despite the loss of connection with the rest of the brain, in vitro hippocampal slice preparations allow detailed physiological and pharmacological studies, which would be impossible, in vivo. There are several methods to induce electrographic seizures on hippocampal slice models. Those are electrical pulse train stimulation, 0 $Mg^{2+}$ artificial cerebrational fluid and high concentration of extracelluar $K^+$ on bath. Among them, the electrically triggered seizure may mimic the physiological communication between neuronal populations without any deterioration of normal physiologic and chemical status of the hippocampal slice models. Presumably, such communication from hyperexcitable areas to other neuronal populations is involved in the development of epilepsy. Electrographic seizures in hippocampal slice models occur in the network of neurons that are involved in epileptic seizures in the hippocampus in vivo. Because these models have many advantages and are very valuable to research of epileptogenesis on partial epilepsy, I would like to introduce the electrophysiological methods to induce electrographic seizure or epilepsy on hippocampal slice models briefly in this paper.

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16-QAM 신호에서 Compact Slice 가중치에 의한 CCA 적응 등화 알고리즘의 성능 비교 (Performance Comparison of the CCA Adaptive Equalization Algorithm based on Compact Slice Weighting Values in 16-QAM Signal)

  • 강대수
    • 한국인터넷방송통신학회논문지
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    • 제13권4호
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    • pp.127-133
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    • 2013
  • 본 논문에서는 통신 채널에서 발생되는 부호간 간섭의 영향을 최소화하기 위하여 사용되는CCA 적응 등화 알고리즘에서 compact slice 가중치에 따른 성능을 비교하였다. CCA 알고리즘은 기존의 결정 지향 알고리즘 (DDA : Decision Directed Algorithm)과 축소 신호점 알고리즘 (RCA : Reduced Constellation Algorithm)의 결합 방식으로 송신 신호의 constant modulus와 결정 장치의 출력 신호를 compact slice 가중치만큼 고려하여 초기의 수렴 특성 및 정상 상태에서 misadjustment에 의한 등화 잡음을 개선시킬 수 있다. 이 과정에서 compact slice 가중치가 적응 등화 알고리즘의 성능에 미치는 영향을 컴퓨터 시뮬레이션을 통해 확인하며, 성능 지수로는 등화기 출력 신호 성상도, 수렴 특성을 나타내는 잔류 isi, 최대 찌그러짐, MSE 및 채널의 신호대 잡음비에 따른 SER을 사용하였다. 시뮬레이션 결과 가중치가 클수록 모든 성능 지수에서 우월하였고, 특히 SER 성능에서는 신호대 잡음비가 적으면 가중치가 적을때가 우월하였고 신호대 잡음비가 클수록 가중치가 클때가 우월함을 알 수 있었다.

토양의 제자리 반전을 위한 몰드보드 플라우의 개발 (Development of a Moldboard Plow to Invert Furrow Slice at the Same Position)

  • 이규승;박원엽;권병기
    • Journal of Biosystems Engineering
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    • 제29권1호
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    • pp.9-20
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    • 2004
  • On the basis of design theory of soil inversion, two types of moldboard plow with secondary soil mover was designed and constructed to invert furrow slice at same position with furrow bottom. A series of soil bin experiment was carried to investigate the performance of prototypes. First prototype of new concept plow showed two kinds of problems during the preliminary experiment. For the plowing depth of 6cut the prototype did not invert the furrow slice, instead it just cut furrow bottom and the furrow slice returned to the original position. For the plowing depth of 8cm, there was soil clogging problem at the rear part of plow. From the above results it was concluded that the first prototype can not be used for the inversion of furrow slice at same position with furrow bottom. Second prototype could invert furrow slice at the same position with furrow bottom, but the performance was affected by soil moisture content soil hardness and plowing speed very much. For the higher soil moisture content, for the higher soil hardness and higher plowing speed, the prototype showed higher soil inversion performance. For the second prototype the inversion ratio was almost 100%, inversion angle was in the range of 90 to 100 degree and side displacement was less than 4 cm. But the furrow slice was not continuous, it was cut in the length of 30 to 40 cm. The reason why the furrow slice was cut in that length is blamed for the design of moldboard surface. The specific draft of prototype was in the range of 37.24 kN/㎡ to 42.14 kN/㎡ this value is a little higher than that of the conventional plow, or from 30.38 kN/㎡ to 33.32 kN/㎡. But the difference was not so big. The inversion performance of the second prototype for the field experiment was much better than that of soil bin experiment due to the better soil and operational conditions. Sticky and compacted soil conditions, and higher plowing speed was suitable for the plowing operation of the second prototype

골프스윙시 인공지능 을 이용한 (Neural Network) 슬라이스 예측에 관한 연구 (The Prediction of 'Slice' Using Neural Network in Golf Swing)

  • 심태용;오승일;신성휴;이상식;문정환
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.1221-1224
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    • 2004
  • In this study, we developed a method classifying slice shot during golf practice using backpropagation algorithm. The 144 data based on the backpropagation model(11 inputs, 2 outputs) was used as a learning set and the model was verified based on the extra 50 data in the process to predict a slice shot in golf swing. The results showed 100% separating rate of learning set and 91.5% separating rate of verified set. The developed method can be potentially beneficial for the predicting of slice shot in an indoor golf excercise setting without applying any additional equipment.

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Helical CT 시스템에 있어 Slice Sensitivity Profile과 Reconstruction Resolution에 관한 연구 (Study on Slice Sensitivity Profile and Reconstruction Resolution on Helical CT System)

  • 윤한식
    • 대한방사선기술학회지:방사선기술과학
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    • 제20권1호
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    • pp.15-20
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    • 1997
  • Unlike conventional CT scan, the helical CT scan uses continuous rotating CT equipment with a slip ring to move the patient's coach at a constant speed while continuously scanning. Slice sensitivity profiles in the Z-position(SSPz) using the conventional X-ray CT have a shape similiar to a rectangular wave, which slightly spreads out into plains below the mountain. However, in the helical CT, with an expansion of the base, the rectangular shape collapses and a mouatain-like shape can be seen. We need to investigate the fellowing factors in helical CT scanning;the ability to scan along the axis of the body, effective slice width, slice shape and the precision of coach velocity, Helical scanning with sprial X-ray track is different from the conventional scanning in terms of the principle of image reconstruction performed. We believe that the problems in helical scanning can be solved by understanding new the special parameters such as the bed moving speed and the interval of image reconstruction.

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Efficient Slice Allocation Method using Cluster Technology in Fifth-Generation Core Networks

  • Park, Sang-Myeon;Mun, Young-Song
    • Journal of information and communication convergence engineering
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    • 제17권3호
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    • pp.185-190
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    • 2019
  • The explosive growth of data traffic and services has created cost challenges for networks. Studies have attempted to effectively apply network slicing in fifth generation networks to provide high speed, low latency, and various compatible services. However, in network slicing using mixed-integer linear programming, the operation count increases exponentially with the number of physical servers and virtual network functions (VNFs) to be allocated. Therefore, we propose an efficient slice allocation method based on cluster technology, comprising the following three steps: i) clustering physical servers; ii) selecting an appropriate cluster to allocate a VNF; iii) selecting an appropriate physical server for VNF allocation. Solver runtimes of the existing and proposed methods are compared, under similar settings, with respect to intra-slice isolation. The results show that solver runtime decreases, by approximately 30% on average, with an increase in the number of physical servers within the cluster in the presence of intra-slice isolation.

CT절편두께와 RP방식이 3차원 의학모델 정확도에 미치는 영향에 대한 연구 (Influence of slice thickness of computed tomography and type of rapid protyping on the accuracy of 3-dimensional medical model)

  • 엄기두;이병도
    • Imaging Science in Dentistry
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    • 제34권1호
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    • pp.13-18
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    • 2004
  • Purpose : This study was to evaluate the influence of slice thickness of computed tomography (CT) and rapid protyping (RP) type on the accuracy of 3-dimensional medical model. Materials and Methods: Transaxial CT data of human dry skull were taken from multi-detector spiral CT. Slice thickness were 1, 2, 3 and 4 mm respectively. Three-dimensional image model reconstruction using 3-D visualization medical software (V-works /sup TM/ 3.0) and RP model fabrications were followed. 2-RP models were 3D printing (Z402, Z Corp., Burlington, USA) and Stereolithographic Apparatus model. Linear measurements of anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared according to slice thickness and RP model type. Results: There were relative error percentage in absolute value of 0.97, 1.98,3.83 between linear measurements of dry skull and image models of 1, 2, 3 mm slice thickness respectively. There was relative error percentage in absolute value of 0.79 between linear measurements of dry skull and SLA model. There was relative error difference in absolute value of 2.52 between linear measurements of dry skull and 3D printing model. Conclusion: These results indicated that 3-dimensional image model of thin slice thickness and stereolithographic RP model showed relative high accuracy.

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Recognition of Radar Emitter Signals Based on SVD and AF Main Ridge Slice

  • Guo, Qiang;Nan, Pulong;Zhang, Xiaoyu;Zhao, Yuning;Wan, Jian
    • Journal of Communications and Networks
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    • 제17권5호
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    • pp.491-498
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    • 2015
  • Recognition of radar emitter signals is one of core elements in radar reconnaissance systems. A novel method based on singular value decomposition (SVD) and the main ridge slice of ambiguity function (AF) is presented for attaining a higher correct recognition rate of radar emitter signals in case of low signal-to-noise ratio. This method calculates the AF of the sorted signal and ascertains the main ridge slice envelope. To improve the recognition performance, SVD is employed to eliminate the influence of noise on the main ridge slice envelope. The rotation angle and symmetric Holder coefficients of the main ridge slice envelope are extracted as the elements of the feature vector. And kernel fuzzy c-means clustering is adopted to analyze the feature vector and classify different types of radar signals. Simulation results indicate that the feature vector extracted by the proposed method has satisfactory aggregation within class, separability between classes, and stability. Compared to existing methods, the proposed feature recognition method can achieve a higher correct recognition rate.

슬라이스 기반 복잡도 척도 (A Slice-based Complexity Measure)

  • 문유미;최완규;이성주
    • 정보처리학회논문지D
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    • 제8D권3호
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    • pp.257-264
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    • 2001
  • 본 논문은 데이터 슬라이스에서의 데이터 토큰들의 정보 흐름에 기초하여 프로그램에서의 정보 흐름을 모델링하는 SIFG(Slicw-based information Graph)를 개발하였다. 다음으로, SIFG에서의 정보 흐름의 복잡도 측정을 통해서 프로그램의 복잡도를 측정하기 위해 SCM(Slice-based Complexity Measure)을 정의하였다. SCM은 Briand가 제시하는 복잡도 메트릭에 필요한 특성들을 만족하였고, 그리고 기존 척도들과는 달리, SCM은 프로그램 내에서의 제어와 데이터 흐름뿐만 아니라 프로그램의 물리적 크기를 반영하는 측정이 이루어졌다.

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