• Title/Summary/Keyword: 근사알고리즘

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Improving the Performance of Decision Boundary Feature Extraction for Neural Networks by Calculating Normal Vector of Decision Boundary Analytically (결정경계 수직벡터의 해석적 계산을 통한 신경망 결정경계 특징추출 알고리즘의 성능 개선)

  • Go, Jin-Uk;Lee, Cheol-Hui
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.3
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    • pp.44-52
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    • 2002
  • In this paper, we present an analytical method for decision boundary feature extraction for neural networks. It has been shown that all the features necessary to achieve the same classification accuracy xxxas in the original space can be obtained from the vectors normal to decision boundaries. However, the vector normal to the decision boundary of a neural network has been calculated numerically using a gradient approximation. This process is time-consuming and the normal vector may be inaccurately estimated. In this paper, we propose a method to improve the performance of the previous decision boundary feature extraction for neural networks by accurately calculating the normal vector When the normal vectors are computed analytically, it is possible to reduce the processing time significantly and improve the performance of the previous implementation that employs numerical approximation.

Design Optimization of an Accumulator for Noise Reduction of Rotary Compressor (공조용 로터리 압축기 소음저감을 위한 어큐뮬레이터 최적설계)

  • Lee, Ui-Yoon;Kim, Bong-Joon;Lee, Jeong-Bae;Sung, Chun-Mo;Lee, Un-Seop;Lee, Jong-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.7
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    • pp.759-766
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    • 2011
  • Recently, noise reduction in room air conditioners has been one of the important issues as well as cooling efficiency. The rotary compressor is the dominant noise source in an air conditioner. A number of studies have been conducted on reducing compressor noise through improving muffler and resonator design. However the noise from the accumulator, a noise delivering path between compressor and air conditioner, is not fully taken into consideration. The accumulator contains a large inner cavity, and usually generates additional resonance noise during operation. This paper aims to conduct an optimal design for reducing accumulator noise by maximizing the transmission loss within the target frequency range that represents high-order nonlinearity. Design of experiments and radial basis function neural network are used in the context of approximate meta-models, and genetic algorithm is used as an optimization tool.

Development of Low-Cost Data Acquisition Method for Close-range Digital Photogrammetric System (근거리 수치사진측량시스템을 위한 저가격 자료획득방법의 개발)

  • Park, Hong-Gi
    • Journal of Korean Society for Geospatial Information Science
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    • v.7 no.2 s.14
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    • pp.143-153
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    • 1999
  • GIS have become easier to use and very popular. In recent year digital photogrammetric systems ire becoming cost-effective tools to build and update GIS databases. In close-range photogrammetry for the acquisition of geospatial data, the bundle adjustment needs both initial approximate values and control points to solve the exterior orientation parameters. This paper gives a review of applied and potential algorithms for estimating Initial approximate values before the bundle adjustment, develope new algorithms for determine the exterior orientation parameters, and gives a cost-effective methods for close-range digital photogrammetric system Modifications of existing DLT algorithm were made in this study for providing an efficient, economic, and more accurate photogrammetric data reduction technique. These modifications include robust approaches for automatic detection and elimination of all lands of gross errors in the measurement data, and incorporation of GPS to reduce the number of control points necessary for a DLT solution. Also, this paper derives a new method for space resection from a monocular image. A major advantage of proposed method is that the solution can be uniquely and analytically determined without initial approximate values of exterior orientation parameters and without iterative computation.

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Integer Inverse Transform Structure Based on Matrix for VP9 Decoder (VP9 디코더에 대한 행렬 기반의 정수형 역변환 구조)

  • Lee, Tea-Hee;Hwang, Tae-Ho;Kim, Byung-Soo;Kim, Dong-Sun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.4
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    • pp.106-114
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    • 2016
  • In this paper, we propose an efficient integer inverse transform structure for vp9 decoder. The proposed structure is a hardware structure which is easy to control and requires less hardware resources, and shares algorithms for realizing entire DCT(Discrete Cosine Transform), ADST(Asymmetric Discrete Sine Transform) and WHT(Walsh-Hadamard Transform) in vp9. The integer inverse transform for vp9 google model has a fast structure, named butterfly structure. The integer inverse transform for google C model, unlike universal fast structure, takes a constant rounding shift operator on each stage and includes an asymmetrical sine transform structure. Thus, the proposed structure approximates matrix coefficient values for all transform mode and is used to matrix operation method. With the proposed structure, shared operations for all inverse transform algorithm modes can be possible with reduced number of multipliers compared to the butterfly structure, which in turn manages the hardware resources more efficiently.

Optimum Design of Rail in Semiconductor Processing (반도체 공정에 이용되는 레일의 최적설계)

  • 조재승;김학선;황종균;임오강
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.3
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    • pp.241-249
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    • 2004
  • There is an over head hoist transporter(OHT) by the system for delivering the wafer in semiconductor processing. The transfer system consist of carrier, vehicle, rail and support. The Tail supporting the wafer and the transfer system should maintain enough strength and stiffness. To achieve lightness and enough strength and stiffness, optimization algorithm should be introduced in design process. In this study, two kinds of section shapes as L-type, C-type is carried out the structure analysis and optimization. Total weight of rail is to be minimized while displacement should not exceed limit. To improve the initial model, topology optimization is done by the plain problem. Size optimization is done with 3D solid element and PLBA algorithm, the RQP algorithm. The weight of optimum model as L-type, C-type is decreased by 2.3%, 10% respectively. It is improved better than the initial model in the strength and stiffness of the structure.

(Turbo Decoder Design with Sliding Window Log Map for 3G W-CDMA) (3세대 이동통신에 적합한 슬라이딩 윈도우 로그 맵 터보 디코더 설계)

  • Park, Tae-Gen;Kim, Ki-Hwan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.9 s.339
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    • pp.73-80
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    • 2005
  • The Turbo decoders based on Log-MAP decoding algorithm inherently requires large amount of memory and intensive complexity of hardware due to iterative decoding, despite of excellent decoding efficiency. To decrease the large amount of memory and reduce hardware complexity, the result of previous research. And this paper design the Turbo decoder applicable to the 3G W-CDMA systems. Through the result of previous research, we decided 5-bits for the received data 6-bits for a priori information, and 7-bits for the quantization state metrics. The error correction term for $MAX^{*}$ operation which is the main function of Log-MAP decoding algorithm is implemented with very small hardware overhead. The proposed Turbo decoder is synthesized in $0.35\mu$m Hynix CMOS technology. The synthesized result for the Turbo decoder shows that it supports a maximum 9Mbps data rate, and a BER of $10^{-6}$ is achieved(Eb/No=1.0dB, 5 iterations, and the interleaver size $\geq$ 2000).

A Combination Method of Unconstrained Handwritten Numerals Recognizers Using Strutural Feature Analyzer (구조적 특징 분석기를 이용한 무제약 필기 숫자 인식기의 결합)

  • Kim, Won-Woo;Paik, Jong-Hyun;Lee, Kwan-Yong;Byun, Hye-Ran;Lee, Yill-Byung
    • Korean Journal of Cognitive Science
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    • v.7 no.1
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    • pp.37-56
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    • 1996
  • In this paper,we design a verifier for unconstrained handwritten numerals using structural feature analysis,and use it as a comnination algorithm for multiple recognizers.The existing combination algorithms mainly use learnings,statistical methods,or probabilistic methods without considering structural features of numerals.That is why they cannot recognize some numerals which human can identify clearly.To overcome the shortcomings,we design one-to-one verifiers which compare and analyze the relative structural features between frequently confused numeral pairs,and apply them to combine multiple recongnizers.Structural features for verification consist of contour,direction al chain code,polygonal approximation,and zero crossing number of horizontal/vertical projections. We gained a 97.95% reliability with CENPARMI numeral data,and showed that some misconceived factors generated from typical combination algorithms can be removed.

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An Efficient Task Assignment Algorithm for Heterogeneous Multi-Computers (이종의 다중컴퓨터에서 태스크 할당을 위한 효율적인 알고리즘)

  • Seo, Kyung-Ryong;Yeo, Jeong-Mo
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.5
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    • pp.1151-1161
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    • 1998
  • In this paper, we are considering a heterogeneous processor system in which each processor may have different performance and reliability characteristics. In other to fully utilize this diversity of processing power it is advantageous to assign the program modules of a distributed program to the processors in such a way that the execution time of the entire program is minimized. This assignment of tasks to processors to maximize performance is commonly called load balancing, since the overloaded processors can perform their own processing with the performance degradation. For the task assignment problem, we propose a new objective function which formulates this imbalancing cost. Thus the task assignment problem is to be carried out so that each module is assigned to a processor whose capabilities are most appropriate for the module, and the total cost is minimized that sum of inter-processor communication cost and execution cost and imbalance cost of the assignment. To find optimal assignment is known to be NP-hard, and thus we proposed an efficient heuristic algorithm with time complexity $O(n^2m)$ in case of m task modules and n processors.

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Analysis on the Planar Bowtie Antenna for IMT-2000 Handset (IMT-2000 핸드셋용 평면형 Bowtie 안테나 해석)

  • Lee, Hee-Suk;Kim, Nam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.5
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    • pp.681-688
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    • 2000
  • In this paper, a planar antenna that is small and light, is designed and analyzed aiming handset antenna of IMT-2000. Employing the Ensemble simulator based on a MoM, design-parameters are found to determine a resonant frequency. Therefore, it is analyzed with the Ensemble simulation and FDTD numerical for resonating at the allocated frequency for IMT-2000 in the fixed antenna dimension of 21$^{\circ}$wing angle that is a design parameter. Analyzing with FDTD method, Though the results of FDTD are very exact, this analysis introduces errors due to the staircasing approximation in the slope of bowtie. To reduce this error, it is divided to 4-ranges where the cell contains the boundary of perfect conductor/free space. Then, each range is calculated by different by different equation, which modify the H-field to add the component of the area and length of the cell filled with free space. Therefore, the modified FDTD algorithm provided with a narrow bandwidth of return loss calculated with a standard FDTD algorithm that can be extended to the desired ranges.

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Improved Method for "Aggregation Based on Situation Assessment" ("상황 평가에 기반을 둔 병합"을 위한 개선 방법)

  • Choe, Dae-Yeong
    • The KIPS Transactions:PartB
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    • v.8B no.6
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    • pp.669-674
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    • 2001
  • In order to reflect the aggregation situation in the aggregation process, aggregation based on situation assessment (ASA) method was proposed in [1]. It consists of the situation assessment model (SAM) and the ASA algorithm. In the SAM, the value of parameter, p, is transformed into the nearest integer value [1]. The integer-typed output of SAM is used as input for an aggregation. The integer-typed output of SAM indicates the current degree of aggregation situation. The ASA algorithm produces at most finite several aggregation results between min and max. In the sequel, the ASA method can not properly handle the applications with the more sophisticated aggregation results between min and max. In order to solve this problem, we propose two improved ASA (I-ASA) methods. In these I-ASA methods, we allow the value of parameter of SAM to be a real number, and suggest two improved ASA algorithms to make continuous aggregation results between min and max. These I-ASA methods can handle both a precise aggregation and an approximate aggregation. Therefore, when compared to the ASA method [1], the proposed I-ASA methods have advantages in that they can handle the applications with the more sophisticated aggregation results and can be used in the more general applications for aggregations.

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