• 제목/요약/키워드: reduction technique

검색결과 2,855건 처리시간 0.025초

The Effects of Total Variation (TV) Technique for Noise Reduction in Radio-Magnetic X-ray Image: Quantitative Study

  • Seo, Kanghyen;Kim, Seung Hun;Kang, Seong Hyeon;Park, Jongwoon;Lee, Chang Lae;Lee, Youngjin
    • Journal of Magnetics
    • /
    • 제21권4호
    • /
    • pp.593-598
    • /
    • 2016
  • In order to reduce the amount of noise component in X-ray imaging system, various reduction techniques were frequently used in the field of diagnostic imaging. Although the previous techniques -such as median, Wiener filters and Anscombe noise reduction technique - were able to reduce the noise, the edge information was still damaged. In order to cope with this problem, total variation (TV) noise reduction technique has been developed and researched. The purpose of this study was to evaluate and compare the image quality using normalized noise power spectrum (NNPS) and contrast-to-noise ratio (CNR) through simulations and experiments with respect to the above-mentioned noise reduction techniques. As a result, not only lowest NNPS value but also highest CNR values were acquired using a TV noise reduction technique. In conclusion, the results demonstrated that TV noise reduction technique is proved as the most practical method to ensure accurate denoising in X-ray imaging system.

시간 동기 비터비 빔 탐색을 위한 인식 시간 감축법 (Recognition Time Reduction Technique for the Time-synchronous Viterbi Beam Search)

  • 이강성
    • 한국음향학회지
    • /
    • 제20권6호
    • /
    • pp.46-50
    • /
    • 2001
  • 본 논문은 HMM (Hidden Markov Model) 음성 인식 시스템에 적용할 수 있는 새로운 인식 시간 알고리즘인 스코아 캐쉬기법을 제안한다. 다른 많은 기법들이 인식 시간을 줄이면서 계산량을 줄이기 위하여 어느 정도의 인식율 저하를 감수하는 반면에 제안하는 스코아 캐쉬기법은 인식율 저하를 전혀 일으키지 않으면서 인식 시간을 상당량 줄일 수 있는 기법이다. 단독어 인식 시스템에 적용 가능할 뿐 아니라 연속어 인식에도 적용이 가능하며, 기존에 이미 설계된 인식 시스템의 구조를 전혀 흩트리지 않고 간단히 하나의 함수만 대치함으로서 인식시간을 크게 감축할 수 있다 또한 기존의 계산량 감축 알고리즘과 함께 적용 가능하므로 추가의 계산량 감소를 얻을 수 있다. 스코아 캐쉬 기법을 적용한 결과 최대 54% 만큼 계산량을 줄일 수 있었다.

  • PDF

Block Cyclic Reduction 기법에 의한 대형 Sparse Matrix 선형 2계편미분방정식의 효율적인 병렬 해 알고리즘 (An efficient parallel solution algorithm on the linear second-order partial differential equations with large sparse matrix being based on the block cyclic reduction technique)

  • 이병홍;김정선
    • 한국통신학회논문지
    • /
    • 제15권7호
    • /
    • pp.553-564
    • /
    • 1990
  • 선계2계 편미분 방정식의 일반식에 대한 계수 메트릭스를 (n-1)x(n-1) submatrices로 나누어서 block tridiagonal system으로 변환한 후 cyclic odd-even reduction 기법을 응용하여 large-grain data granularity로서 미지벡타를 구하는 block cyclic reduction 알고리즘을 작성했다. 그런데 이 block cyclic reduction 기법은 매 연산의 단계마다 병렬성이 변하여 병렬처리형 컴퓨터에는 적합하지 못하므로 이 기법을 변형해서 병렬성이 일정하며 실행시간이 보다 단축되는 block cyclic reduction 기법을 제안하고 이 기법에 의한 선형2계 편미분 방정식의 일반식의 解를 구하는 알고리즘을 작성하여 기존의 기법과 비교 고찰했다.

  • PDF

벡터 내적을 위한 효율적인 ROM 면적 감소 방법 (Efficient ROM Size Reduction for Distributed Arithmetic)

  • 최정필;성경진;유경주;정진균
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 1999년도 하계종합학술대회 논문집
    • /
    • pp.821-824
    • /
    • 1999
  • In distributed arithmetic-based architecture for an inner product between two length-N vectors, the size of the ROM increases exponentially with N. Moreover, the ROMs are generally the bottleneck of speed, especially when their sire is large. In this paper, a ROM size reduction technique for DA (Distributed Arithmetic) is proposed. The proposed method is based on modified OBC (Offset Binary Coding) and control circuit reduction technique. By simulations, it is shown that the use of the proposed technique can result in reduction in the number of gates up to 50%.

  • PDF

ATOM technique: Anatomic reduction using screw-wire Traction for Open reduction and internal fixation of Mandibular fractures

  • Ingole, Pranav D.;Rajguru, Jignesh G.;Budhraja, Nilima J.;Shenoi, Ramakrishna S.;Karmarkar, Jui S.;Dahake, Rahul N.
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • 제48권2호
    • /
    • pp.122-124
    • /
    • 2022
  • Various techniques are well documented to obtain anatomic reduction, such as reduction forceps, manual reduction, or a combination of these methods. However, these techniques have inherent drawbacks. We propose a new intra-operative technique for anatomic reduction using screw-wire traction for open reduction and internal fixation of mandibular fractures.

관절면을 침범한 설상형 종골골절의 수술적 치료: 관혈적 및 Essex-Lopresti 술식에 따른 비교 (Operative Treatment of Tongue Type Intra-articular Calcaneal Fractures: Comparison of the Open Reduction and Essex-Lopresti Technique)

  • 신동은;윤형구;한수홍;최우진;안창수;옥현수
    • 대한족부족관절학회지
    • /
    • 제14권2호
    • /
    • pp.151-156
    • /
    • 2010
  • Purpose: To analyze the clinical and radiological results of operative treatment in patients with tongue type intra-articular calcaneal fracture, and to compare the open reduction and Essex-Lopresti technique. Materials and Methods: We examined a consecutive series of 42 patients who received surgical treatment for tongue type calcaneal fracture (24 cases of the open reduction and 18 cases of the Essex-Lopresti technique) and the postoperative data was compared with a minimum 1 year follow-up. The clinical outcome was analyzed using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale and Salama's criteria. The preoperative, postoperative, and last follow-up changes in the Bohler angle was radiologically analyzed. Results: There were no significant differences between the two groups in terms of the clinical and radiological results at the last follow-up. However, for the Sander's type 3 and 4 fractures, the open reduction group showed more improvement of AOFAS score and less reduction loss in the Bohler angle. Conclusion: Although the clinical results were good irrespective of surgical technique, the open reduction and internal fixation can improve clinical outcome and reduce the reduction loss as compared with the Essex-Lopresti technique in the comminuted tongue type calcaneal fracture.

유도전동기 벡터제어 시스템의 EMI저감을 위한 새로운 PWM기법 (A Novel PWM Swiching Technique for Conducted EMI Reduction in Vector-Controlled Induction Motor Drive)

  • 배우리;이원철;유재성;김이훈;함년근;원충연
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2005년도 전력전자학술대회 논문집
    • /
    • pp.321-324
    • /
    • 2005
  • This paper describes the application of newly developed conducted EMI reduction technique of SVPWM in induction motor drive. The newly developed common mode voltage reduction SVPWM technique doesn't any zero-voltage vector states for inverter control. Hence it can restrict the common mode voltage better than conventional PWM technique. The proposed technique is verified through simulation and experimental results. And by applying vector-controled system, the proposed technique have superior ability of reducing EMI and equal control performance comparing conventional SVPWM technique.

  • PDF

A Developing Approach of 600 W SHF TWTA for Communications Using Cathode Ripple Reduction Technique

  • Hong, In-Pyo
    • Journal of electromagnetic engineering and science
    • /
    • 제8권3호
    • /
    • pp.119-128
    • /
    • 2008
  • In this paper, we propose a developing approach of 600 W super high frequency(SHF) traveling wave tube amplifier (TWTA) for communications. Also, we make a TWTA called the experimental-TWTA(ETWTA), which uses a cathode ripple reduction technique to improve RF performance. After implementation, we discuss, and compare it with some other TWTAs. Its RF performance is better than that of other TWTAs. Therefore, this methodology can be used to develop the high power SHF TWTA for communications.

강도 감소법에 의한 지하수위를 고려한 FEM 사면안정해석 (Slope Stability Analysis Considering Seepage Conditions by FEM Using Strength Reduction Technique)

  • 김영민
    • 한국지반공학회논문집
    • /
    • 제20권8호
    • /
    • pp.97-102
    • /
    • 2004
  • 본 논문은 기존의 한계 평형법 보다 사면의 파괴거동을 잘 묘사할 수 있는 유한요소법에 의한 사면의 안전율을 결정하는 방법에 대하여 기술하였다. 특히, 지하수위를 고려하는 사면의 파괴거동을 강도감소법에 의한 유한요소법으로 산정하였다. 그 결과, 강도 감소법을 이용한 FEM해석방법이 사면의 안정해석에 대하여 파괴거동과 안전율을 구하는데 유효한 수단임을 보여 주었다. 그리고 지하수 상승경우와 지하수 급강하 사면의 경우에 대하여 자세히 분석하였으며, 한계평형법인 Bishop간편법 해석결과와 비교, 검토하였다.

구매원가절감에 관한 연구 (VA 활동을 중심으로) (A Study on the Purchasing Cost Reduction -through Value Analysis Technique-)

  • 여동길
    • 산업경영시스템학회지
    • /
    • 제2권2호
    • /
    • pp.11-18
    • /
    • 1979
  • The purpose of this study is to establish a purchasing cost reduction program for the management practical use. The research method of this study is a bibliographical search of the materials available in the library at Keimyung University and the writer's private study, and the case analysis. The body of this study is divided into three sections. The first section deals with the purchasing management systems in terms of the nature and characters of purchasing management and purchasing cost in total management system. The second section includes purchasing cost reduction program through value analysis technique and the third section covers summary and the following conclusions : 1) Top management should be aware of the important position of purchasing activities from the cost point of view, and they should be aware that a good purchasing cost reduction program could be established through value analysis technique. 2) For such a purchasing cost reduction program to be carried out. effectively the management should support and back up the program. 3) There should be a training program to educate and develop the personnel who can manage and operate the purchasing cost reduction program through valuean analysis technique. 4) And cooperative system should be established in management and operative organization system from the total management systems, view for the effective use of the program.

  • PDF