• 제목/요약/키워드: Specific Point Method

검색결과 619건 처리시간 0.026초

지형 단면을 이용한 의미점 추출에 관한 연구 (A Study On Extracting Surface-Specific Point Using The Cross Section of The Terrain)

  • 류승택;윤경현
    • 대한공간정보학회지
    • /
    • 제6권2호
    • /
    • pp.133-141
    • /
    • 1998
  • 지형 모델링은 사각그리드에 의한 방법과 불규칙 삼각망을 이용한 방법으로 나눌 수 있다. 특히 불규칙 삼각망에 의한 방법은 적은 지형 데이터로써 지형의 특징을 잘 표현할 수 있고 렌더링시간을 단축시킬 수 있어 널리 사용되고 있다. 이러한 불규칙 삼각망을 만들기 위해서는 의미점 추출과정과 삼각형화 과정이 필요하다. 본 논문은 이러한 전처리 작업 중 의미점 추출과정의 개선에 중점을 두었다. 의미점을 추출하는 방법에는 8방향 이웃점 검사 방법과 이를 변형한 방법들이 많이 사용되고 있다. 또한 다각형 감소 기법을 응용하여 불필요한 점들을 제거하는 방법도 제안되고 있다. 그중 기본적으로 사용하는 8방향 이웃점 검사 방법을 이용한 의미점 추출 방법은 필요 없는 점들을 추출한다는 문제점을 가지고 있다. 이러한 문제점을 해결하기 위해서 지형 단면을 이용한 의미점 추출방법을 제안한다. 이 방법은 기존의 방법보다 의미점 추출 시간이 빠르고 적은 지형 자료로 보다 정확한 특징점을 추출할 수 없다.

  • PDF

Numerical Design and Performance Prediction of Low Specific Speed Centrifugal Pump Impeller

  • Yongxue, Zhang;Xin, Zhou;Zhongli, Ji;Cuiwei, Jiang
    • International Journal of Fluid Machinery and Systems
    • /
    • 제4권1호
    • /
    • pp.133-139
    • /
    • 2011
  • In this paper, Based on Two-dimensional Flow Theory, adopting quasi-orthogonal method and point-by-point integration method to design the impeller of the low specific speed centrifugal pump by code, and using RANS (Reynolds Averaged N-S) Equation with a standard k-${\varepsilon}$ two-equation turbulence model and log-law wall function to solve 3D turbulent flow field in the impeller of the low specific speed pump. An analysis of the influences of the blade profile on velocity distributions, pressure distributions and pump performance and the investigation of the flow regulation pattern in the impeller of the centrifugal pump are presented. And the result shows that this method can be used as a new way in low speed centrifugal pump impeller design.

특정처리가 최우수 처리인가의 판정방법 (A Method for Detecting Whether a Specific Treatment is the Best)

  • 정규진
    • 품질경영학회지
    • /
    • 제20권1호
    • /
    • pp.33-38
    • /
    • 1992
  • Consider a situation that a specific treatment is regarded as the best in comparing several treatments. In this case, a natural procedure to decide the best treatment is to choose the specific one which is proved to be better than each one of the others. This study proposes a method for detecting the best by comparing two treatments from the above point of view. Since this method deals with comparing only two treatments, it is very simple to use and expected to be widely applicable.

  • PDF

Uncertainty Assessment: Relative versus Absolute Point Dose Measurement for Patient Specific Quality Assurance in EBRT

  • Mahmood, Talat;Ibrahim, Mounir;Aqeel, Muhammad
    • 한국의학물리학회지:의학물리
    • /
    • 제28권3호
    • /
    • pp.111-121
    • /
    • 2017
  • Verification of dose distribution is an essential part of ensuring the treatment planning system's (TPS) calculated dose will achieve the desired outcome in radiation therapy. Each measurement have uncertainty associated with it. It is desirable to reduce the measurement uncertainty. A best approach is to reduce the uncertainty associated with each step of the process to keep the total uncertainty under acceptable limits. Point dose patient specific quality assurance (QA) is recommended by American Association of Medical Physicists (AAPM) and European Society for Radiotherapy and Oncology (ESTRO) for all the complex radiation therapy treatment techniques. Relative and absolute point dose measurement methods are used to verify the TPS computed dose. Relative and absolute point dose measurement techniques have a number of steps to measure the point dose which includes chamber cross calibration, electrometer reading, chamber calibration coefficient, beam quality correction factor, reference conditions, influences quantities, machine stability, nominal calibration factor (for relative method) and absolute dose calibration of machine. Keeping these parameters in mind, the estimated relative percentage uncertainty associated with the absolute point dose measurement is 2.1% (k=1). On the other hand, the relative percentage uncertainty associated with the relative point dose verification method is estimated to 1.0% (k=1). To compare both point dose measurement methods, 13 head and neck (H&N) IMRT patients were selected. A point dose for each patient was measured with both methods. The average percentage difference between TPS computed dose and measured absolute relative point dose was 1.4% and 1% respectively. The results of this comparative study show that while choosing the relative or absolute point dose measurement technique, both techniques can produce similar results for H&N IMRT treatment plans. There is no statistically significant difference between both point dose verification methods based upon the t-test for comparing two means.

Phase Shift Analysis and Phase Identification for Distribution System with 3-Phase Unbalanced Constant Current Loads

  • Byun, Hee-Jung;Shon, Sugoog
    • Journal of Electrical Engineering and Technology
    • /
    • 제8권4호
    • /
    • pp.729-736
    • /
    • 2013
  • Power grids are large complicated networks in use around. An absolute phase value for a particular unknown-phase line at a local site should be identified for the operation and management of a 3-phase distribution network. The phase shift for a specific point in the line, as compared with a phase reference point at a substation, must be within a range of ${\pm}60^{\circ}$ for correct identification. However, the phase shift at a particular point can fluctuate depending on the line constants, transformer wiring method, line length, and line amperage, etc. Conducted in this study is a theoretical formulation for the determination of phase at a specific point in the line, Simulink modeling, and analysis for a distribution network. In particular, through evaluating the effects of unbalanced current loads, the limitations of the present phase identification methods are described.

Distinctive point extraction and recognition algorithm for counters for the various kinds of bank notes

  • Joe, Yong-won;An, Eung-seop;Lee, Jae-kang;Kim, Il-hwan
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2002년도 ICCAS
    • /
    • pp.90.1-90
    • /
    • 2002
  • Counters for the various kinds of bank notes require high-speed distinctive point extraction and recognition for notes. In this paper we propose a new point extraction and recognition algorithm for bank notes. For distinctive point extraction we use a coordinate data extraction method from specific parts of a bank note representing the same color. The recognition algorithm uses a back-propagation neural network that has coordinate data input. The proposed algorithm is designed to minimize recognition time.

  • PDF

Automatic $St{\ddot{o}}ckigt$ Sizing Test Using Hue Value Variation of a Droplet

  • Kim, Jae-Ok;Kim, Chul-Hwan;Lee, Young-Min;Kim, Gyeong-Yun;Shin, Tae-Gi;Park, Chong-Yawl
    • 한국펄프종이공학회:학술대회논문집
    • /
    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
    • /
    • pp.227-230
    • /
    • 2006
  • The $St{\ddot{o}}ckigt$ sizing test of the most-commonly used sizing tests is easily influenced by the individual testers' bias in recognizing red coloration. Therefore the test had to be modified to improve its reliability and reproducibility by automated recognition of a coloration procedure during testing. In order to achieve this, all measured variables occurring during the $St{\ddot{o}}ckigt$ test was first be analyzed and then reflected in the new automatic system. Secondly, the most important principle applied was to transform the RGB values of the droplet image to hue (H), saturation (S) and value (V) respectively. This is because RGB cannot be used as a color standard, owing to RGB's peculiarity of being seriously affected by the observer's point of view. Therefore, the droplet color had to be separated into three distinct factors, namely the HSV values, in order to allow linear analysis of the droplet color. When the average values of the vectors calculated during color variation from yellow to brown were plotted against time, it was possible to determine the vector value of hue, the most sensitive factor among HSV, at the specific time by differentiation of a function when it exceeds the critical point. Then, the specific time consumed up to the critical point was regarded as the $St{\ddot{o}}ckigt$ sizing degree. The conventional method took more time to recognize an ending point of coloration than the automatic method, and in addition the error ranges of the conventional sizing degrees on the specific addition points of AKD were wider than those of the automatic method.

  • PDF

Detection of rare point mutation via allele-specific amplification in emulsion PCR

  • Cheng, Changming;Zhou, Yin;Yang, Chao;Chen, Juan;Wang, Jie;Zhang, Jie;Zhao, Guoping
    • BMB Reports
    • /
    • 제46권5호
    • /
    • pp.270-275
    • /
    • 2013
  • It is essential to analyze rare mutations in many fields of biomedical research. However, the detection of rare mutations is usually failed due to the interference of predominant wild-type DNA surrounded. Herein we describe a sensitive and facile method of detecting rare point mutation on the basis of allele-specific amplification in emulsion PCR. The identification and selective amplification of rare mutation are accomplished in one-pot reaction. The allele-specific primers coupled on magnetic beads allow the exclusive amplification and enrichment of the mutant amplicons. The productive beads bearing mutant amplicons are subsequently stained with the fluorescent dyes. Thus, the rare point mutations with a percentage as low as 0.1%, can be detected by fluorescent analysis. The relative percentages of mutation among different samples can be roughly accessed by counting the fraction of fluorescent positive beads through flow cytometry.

3상 불평형 정전류 부하 조건에서의 동 위상 판별에 대한 분석 및 한계에 관한 연구 (A Study on the Analysis and Limitations of the Same Phase Identification Under 3-Phase Unbalanced Constant Current Loads)

  • 변희정;손수국
    • 조명전기설비학회논문지
    • /
    • 제26권6호
    • /
    • pp.38-46
    • /
    • 2012
  • In this paper, the necessity for the identification of the absolute phase value is introduced and analyzed for a particular conductor line of a 3-phase type distribution network and the recent methods are also introduced. For the determination of the exact phase value for a specific point in the line, as compared with the phase reference point, the measured phase value must be within a range of ${\pm}60[^{\circ}]$. However, the phase of a particular point can fluctuate depending on the line constant, transformer wiring method, line length, line amperage, etc. A theoretical formulation such as Simulink modeling and analysis for a distribution network are conducted for the identification of phase at a specific point in the line. In particular, through evaluating the effects of unbalanced current loads at the time of determination of the phase value, the limitations of the present method for the determination of phases is described.

Rapid, Sensitive, and Specific Detection of Clostridium tetani by Loop-Mediated Isothermal Amplification Assay

  • Jiang, Dongneng;Pu, Xiaoyun;Wu, Jiehong;Li, Meng;Liu, Ping
    • Journal of Microbiology and Biotechnology
    • /
    • 제23권1호
    • /
    • pp.1-6
    • /
    • 2013
  • Tetanus is a specific infectious disease, which is often associated with catastrophic events such as earthquakes, traumas, and war wounds. The obligate anaerobe Clostridium tetani is the pathogen that causes tetanus. Once the infection of tetanus progresses to an advanced stage within the wounds of limbs, the rates of amputation and mortality increase manifold. Therefore, it is necessary to devise a rapid and sensitive point-of-care detection method for C. tetani so as to ensure an early diagnosis and clinical treatment of tetanus. In this study, we developed a detection method for C. tetani using loop-mediated isothermal amplification (LAMP) assay, wherein the C. tetani tetanus toxin gene was used as the target gene. The method was highly specific and sensitive, with a detection limit of 10 colony forming units (CFU)/ml, and allowed quantitative analysis. While detecting C. tetani in clinical samples, it was found that the LAMP results completely agreed with those of the traditional API 20A anaerobic bacteria identification test. As compared with the traditional API test and PCR assay, LAMP detection of C. tetani is simple and rapid, and the results can be identified through naked-eye observation. Therefore, it is an ideal and rapid point-of-care testing method for tetanus.