• 제목/요약/키워드: Level set methods

검색결과 1,019건 처리시간 0.029초

DIACON 정도관리물질의 평가 (Evaluation of quality control, DIACON)

  • 김병찬;정창기;김상수;박혜미;김지선
    • 핵의학기술
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    • 제19권1호
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    • pp.44-50
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    • 2015
  • Purpose Quality control used in laboratory help to sustain precision and accuracy consistently to ensure the Diagnostic and treatment for medical employee. To perform an evaluation in statistical manner, it is recommended to use different quality control material than calibrator from manufacturer, quality control material must include analyzed concentration perimeter, must use more than two different concentration materials and recommended to use materials to indicate the concentration in clinical use. However, currently used quality control material has limit of evaluation due to unconsidered concentration or improperly used to get clinical importance data. Therefore, we compared the value of quality control, DIACON Hormone Level 1, 2, 3 (Scantibodies, USA) and DIACON Tumor Level 1, 2, 3 which applied to clinical concentration range. Materials and Methods DIACON Hormone Level 1, 2, 3 (Scantibodies, USA) and DIACON Tumor Level 1, 2, 3 (Scantibodies, USA) that used materials and methods test to compare the result from five RIA testing institution and one institution that used Elecsys (ROCHE) and Architect (ABOTT) for each level. The reagent RIA kit that used in this experiment is followed by Table 2 and 3. Test has performed by instruction itself and follow by instruction. Results Among DIACON hormone result of twenty four items, level 1 have three items, level 2 have four items and level 3 have five items were out of manufacturer set up range based on the average value. Among DIACON tumor result of thirteen items, level 1 have three items, level 2 have four items and level 3 have five items were out of manufacturer set up range. Other result were inside of manufacturer range. Conclusion For quality control material, it is widely available in market, but it is limited for normal range which is only concerned in improper clinical value and difficult to evaluate important concentration area in terms of clinical analyze. In this experiment, we evaluate Hormone twenty three items and Tumor thirteen items with DIACON Hormone and Tumor (Scantibodies, USA) to resolve this limit and we could observe that it ca be substituted and used.

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Robust Unit Root Tests with an Innovation Variance Break

  • Oh, Yu-Jin
    • Communications for Statistical Applications and Methods
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    • 제19권1호
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    • pp.177-182
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    • 2012
  • A structural break in the level as well as in the innovation variance has often been exhibited in economic time series. In this paper we propose robust unit root tests based on a sign-type test statistic when a time series has a shift in its level and the corresponding volatility. The proposed tests are robust to a wide class of partially stationary processes with heavy-tailed errors, and have an exact binomial null distribution. Our tests are not affected by the size or location of the break. We set the structural break under the null and the alternative hypotheses to relieve a possible vagueness in interpreting test results in empirical work. The null hypothesis implies a unit root process with level shifts and the alternative connotes a stationary process with level shifts. The Monte Carlo simulation shows that our tests have stable size than the OLSE based tests.

다계층 공생 진화알고리듬을 이용한 공급사슬경영의 생산과 분배의 통합계획 (An Integrated Planning of Production and Distribution in Supply Chain Management using a Multi-Level Symbiotic Evolutionary Algorithm)

  • 김여근;민유종
    • 한국경영과학회지
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    • 제28권2호
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    • pp.1-15
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    • 2003
  • This paper presents a new evolutionary algorithm to solve complex multi-level integration problems, which is called multi-level symbiotic evolutionary algorithm (MEA). The MEA uses an efficient feedback mechanism to flow evolution information between and within levels, to enhance parallel search capability, and to improve convergence speed and population diversity. To show the MEA's applicability, It is applied to the integrated planning of production and distribution in supply chain management. The encoding and decoding methods are devised for the integrated problem. A set of experiments has been carried out, and the results are reported. The superiority of the algorithm's performance is demonstrated through experiments.

체계적 관점에 따른 기술전파활동의 상호작용 수준 분석 - 지역특화작목시험장의 기술전파활동을 중심으로 - (A Study on the Level of Interaction in Extension Services through a Systems Approach - Focused on Extension Services of Experiment Station -)

  • 황정임;최상호
    • 농촌계획
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    • 제12권4호
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    • pp.99-114
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    • 2006
  • Under awareness of the importance of interaction between local research agencies and farmers in developing local agriculture, this study attempts to analyse the level of interaction in extension services of Experiment Station. The data were collected through the interview with researchers in five Experiment Stations and farmers who have made contact with the researchers. The results of the analysis are as follow: (1) The Experiment Stations are currently providing extension services though they are originally research-oriented agencies. The extension methods of Experiment Stations are similar with those of extension agencies. (2) The more systematic the characteristic of extension service type is, the higher level of interaction is generated with several exceptions which should not be ignored. This study accentuates the efforts to improve the level of interaction as well as to construct a system as a linked set of actors.

프랙탈 기법을 이용한 3차원 지형의 다중 추상화 (A Fractal Based Approach for Multi Level Abstraction of Three Dimensional Terrain)

  • 박미정;이정재
    • 농촌계획
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    • 제11권1호
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    • pp.9-15
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    • 2005
  • Preservation of geometrical context of terrains in a digitized format is useful in handling and making modification to the data. Digitization of three-dimensional terrain still proves a great challenge due to heavy load of context required to retain details of topological and geometrical information. Methods of simplification, restoration and multi-level terrain generation are often employed to transform the original data into a compressed digital format. However, reduction of the stored data size comes at an expense of loss of details in the original data set. This article reports on an alternative scheme for simplification and restoration of terrain data. The algorithm utilizes the fact that the terrain formation and patterns can be predicted and modeled through the fractal algorithm. This method was used to generate multi-level terrain model based on NGIS digital maps with preserving geometrical context of terrains.

A comparative study of different radiometric methodologies for the determination of 226Ra in water

  • Al-Hamarneh, Ibrahim F.;Almasoud, Fahad I.
    • Nuclear Engineering and Technology
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    • 제50권1호
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    • pp.159-164
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    • 2018
  • An evaluation of various radiometric methods to analyze $^{226}Ra$ in water has been employed on a set of 10 standard solutions of different concentrations in the range of $1-10Bq/L^{-1}$. The analysis was carried out using well-established procedures by means of gamma-ray, alpha-particle and liquid scintillation spectrometry. The feasibility of the various methods has been quantified in terms of relative standard error and percentage error. Correlations between the various methods have been presented and discussed. In general, good agreement was found in the results of various methodologies, which assures the accuracy of the methods and allows for the validation of instrumentation and procedures. Of the different methods adopted here, a combined procedure for the determination of $^{226}Ra$ along with $^{228}Ra$ using Quantulus 1220 ultra-low level background liquid scintillation counting gave the most accurate results.

투영 등위 집합을 이용한 다면체 모델의 부분 매개 변수화 (Local Parameterization of Polygonal Models Using Projection Level Set)

  • 이연주;차득현;장병준;임인성
    • 한국정보과학회논문지:시스템및이론
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    • 제34권12호
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    • pp.641-655
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    • 2007
  • 컴퓨터 그래픽스를 비롯한 여러 응용 분야에서 3차원 다면체 모델에 대한 매개 변수화(parameterization) 기법이 중요하게 연구되어왔다. 매개 변수화에 대한 연구는 주로 3차원 다면체 모델을 2차원 평면으로 매핑 시켜주는 문제를 고려하는데, 이러한 매핑 과정에서 종종 다각형의 세밀한 형태를 제대로 표현하지 못하거나, 텍스처 매핑 등의 기법을 적용할 때 일부 왜곡이 발생하는 문제가 발생하고는 한다. 이러한 문제점을 해결하기 위해서 여러 가지 왜곡 처리 방법이 연구되었지만, 3차원 물체의 임의 영역에 대한 사각형 형태의 부분 매개 변수화(local parameterization)를 수행하기에는 종종 한계점을 가지고 있었다. 본 논문에서는 투영 등위 집합이라고 하는 수학적 도구를 사용하여 3차원 다면체 모델의 특정 지역을 효과적으로 매개 변수화 해주는 기법을 제안한다. 이 방법에서는 사용자가 지정한 임의의 영역에 대해 등간격의 곡선을 생성한 후, 이를 이용하여 사각형 형태의 영역에 대한 부분 매개 변수화 정보를 추출하는 방식을 취한다. 본 논문에서는 새로운 부분 매개 변수화 기법에 대하여 자세히 설명한 후 실험 결과를 기술하도록 한다.

수준별 학습을 위한 퍼지 집합 기반 적응형 교수 시스템 (An Adaptive Tutoring System based on Fuzzy sets for Learning by Level)

  • 최숙영;소지숙;이순정
    • 컴퓨터교육학회논문지
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    • 제6권2호
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    • pp.121-135
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    • 2003
  • 본 연구는 학습자 수준에 맞는 학습 내용과 평가 문제를 제공하고, 그 평가 결과에 기반하여 반복학습 및 심화학습을 효과적으로 제공하며, 차기 학습을 할 경우에 이에 기초하여 적절한 학습이 이루어질 수 있도록 하는 적응형 웹기반 교수 시스템을 제안한다. 이를 위해 코스웨어 설계시 학습목표의 중요도, 학습내용의 난이도, 학습목표와 학습내용과의 관련도에 따라 퍼지 수준 집합을 구성하고 이를 기반으로 학습자의 수준에 맞는 내용을 제공한다. 또한, 학습의 평가시에도 문제의 난이도, 평가문항과의 관련도를 고려하여 평가 결과를 제시하게 된다. 본 논문에서 제시하는 퍼지 집합에 의한 학습 내용의 제공과 평가 결과는 학습과정에 나타나는 여러 가지 다양하고 불확실한 요소들을 고려하여 처리함으로써 보다 융통성 있고 효과적인 교수 학습 방법을 제공할 수 있도록 한다.

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라돈의 가이드라인 고찰 및 선량 예측 (Review of Guidelines for Radon and Estimation of Radiation dose)

  • 정은교;김갑배;장재길;송세욱
    • 한국산업보건학회지
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    • 제26권2호
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    • pp.109-118
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    • 2016
  • Objectives: To review reference levels by the international and domestic management and provide the basis for setting occupational exposure limits(OELs) of radon in Korea Methods: Government's organizations with laws and systems for monitoring radon exposure were investigated and compared. There are five laws governing Indoor Air Quality(IAQ) control such as Occupational Safety and Health Act, Indoor Air Quality Control in Public Use Facilities, Etc. Act, School Health Act, Public Health Control Act and Parking Lot Act in Korea. It was surveyed that a total of 32 countries including 24 countries in the European Union(EU), six countries in Asian and two countries in North America setting the reference levels for radon in the world. Results: In Korea, there are set guidelines for radon in the Ministry of Environment and the Ministry of Education. Reference levels of radon for existing dwellings were $150{\sim}400Bq/m^3$ for Western European countries, and $200{\sim}1,500Bq/m^3$ in Eastern European countries. Approximately 67% of those EU countries were set up $400Bq/m^3$ to the standards for existing dwellings. EU countries such as Luxembourg, Finland, Norway, Sweden and Russia had adopted mandatory level for radon. Radon guidelines for new dwellings were set more strictly reference level($200Bq/m^3$) than existing dwellings. Conclusions: International organizations such as ICRP, UNSCEAR and NCRP, etc. had recommended the guidelines for radon. It was calculated the relation of the dose conversion factors with the annual effective doses. the OELs of radon suggest to need to establish $150Bq/m^3$ for office room and $400{\sim}1,000Bq/m^3$ for the workplace.

Accuracy of digital periapical radiography and cone-beam computed tomography in detecting external root resorption

  • Creanga, Adriana Gabriela;Geha, Hassem;Sankar, Vidya;Teixeira, Fabricio B.;McMahan, Clyde Alex;Noujeim, Marcel
    • Imaging Science in Dentistry
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    • 제45권3호
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    • pp.153-158
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    • 2015
  • Purpose: The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. Materials and Methods: Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. Results: A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. Conclusion: CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption.