• Title/Summary/Keyword: A level-set method

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Distributions of Hydrogeological Variables and Flow Field on GIS Digital Map (GIS 수치지도를 이용한 수리지질학적 변수와 지하수 유동의 분포)

  • Lee, Cheo K.
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.2
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    • pp.45-58
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    • 1999
  • Digital map is utilized for an effective display of the distributions of the hydrogeological variables such as water table height(hydraulic head) and log-transmissivity(lnT) in north Pohang, KyungBug. Specifically the geostatistical method kriging is used to construct the distributions in an unconfined aquifer from a finite set of measured data. The experimental variograms for both the head and lnT suggest spherical models with nugget of 0 and range of 6km. The kriged results by using these variograms show that the head decreases primarily from the west to the east with a large peak in the north-western part and lnT is at the maximum level in the central part with outwardly decreasing trend. The constructed delineation is also used to calculate the flow field in the region. Finite differences with second order consistency are used to calculate the fluxes in the east(x) and north(y) across a vertical cross-section of unit width and height equal to the thickness of the wet zone in the aquifer. It is demonstrated that the flow is dominantly in the east with diverging trend on the eastern hillside of the water table peak. A few convergent spots also appear.

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Determination of In-focus Criteria In Image Processing Method for Particle Size Measurement (입경측정을 위한 영상처리기법에서 입자 초점면 존재 판단 기준의 설정)

  • Koh, Kwang Uoong;Kim, Joo Youn;Lee, Sang Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.3
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    • pp.398-407
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    • 1999
  • In the present image processing technique, the concept of the gradient indicator(GI) has been introduced to find out the depth-of-field in sizing large particles ranging from $30{\mu}m$ to $30{\mu}m$ where using of the concept of the normalized contrast value(VC) is not appropriate. The gradient indicator is defined as the ratio of the local value to the maximum possible value of the gray-level gradient in an image frame. The gradient indicator decreases with the increases of the particle size and the distance from the exact focal plane. A particle is considered to be in focus when the value of the gradient indicator at its image boundary stays above a critical value. This critical gradient indicator($GI_{critical}$) is defined as the maximum gradient indicator($GI_{max}$) subtracted by a constant ${\Delta}GI$ which is to account for the particle-size effect. In the present ca.so, the value of ${\Delta}GI$ was set to 0.28 to keep the standard deviation of the measured particles mostly within 0.1. It was also confirmed that, to find the depth-of-field for small particles(${\leq}30{\mu}m$) with the same measurement accuracy, tho concept of the critical normalized contrast($VC_{critical}$) is applicable with 85% of the maximum normalized contrast value($VC_{max}$). Finally, the depth-of-field was checked for the size range between $10{\mu}m$ and $300{\mu}m$ when the both in-focus criteria ($GI_{critical}$ and $VC_{critical}$) were adopted. The change of the depth-of-field with the particle size shows good linearity in both the VC-applicable and the GI-applicable ranges with a reasonable accuracy.

Development of PCR-Based Sequence Characterized DNA Markers for the Identification and Detection, Genetic Diversity of Didymella bryoniae with Random Amplified polymorphic DNA(RAPD)

  • Kyo, Seo-Il;Shim, Chang-Ki;Kim, Dong-Kil;Baep, Dong-Won;Lee, Seon-Chul;Kim, Hee-Kyu
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.130-130
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    • 2003
  • Gummy stem blight pathogen is very difficult not only to monitor the inoculum levels prior to host infection, and also it is destructive and hard to control in field condition. We have applied RAPD technique to elucidate the genetic diversity of the genomic DNA of Didymella bryoniae and also to generate specific diagnostic DNA probe useful for identification and detection. The 40 primers produced clear bands consistently from the genomic DNA of twenty isolates of Didymella bryoniae, and two hundred seventy-three amplified fragments were produced with 40 primers. The combined data from 273 bands was analyzed by a cluster analysis using UPGMA method with an arithmetic average program of NTSYS-PC (Version 1.80) to generate a dendrogram. At the distance level of 0.7, two major RAPD groups were differentiated among 20 strains. RAPD group (RG) I included 8 isolates from watermelon except one isolate from melon. RAPD group (RG) IV included 12 isolates from squash, cucumber, watermelon and melon.. In amplification experiment with SCAR specific primer RG1F-RG1R resulted in a single band of 650bp fragment only for 8 isolates out of 20 isolates that should be designated as RAPD Group 1. However, same set of experiment done with RGIIF-RGIIR did not result in any amplified product.. Our attempts to detect intraspecific diversity of ITS region of rDNA by amplifying ITS region and 17s rDNA region for 20 isolates and restriction digestion of amplified fragment with 12 enzymes did not reveal polymorphic band. In order to develop RAPD markers for RGIV specific primer, a candidate PCR fragment( ≒1.4kb) was purified and Southern hybridized to the amplified fragment RGIV isolates. This promising candidate probe recognized only RGIV isolates

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Analysis Process based on Modify K-means for Efficiency Improvement of Electric Power Data Pattern Detection (전력데이터 패턴 추출의 효율성 향상을 위한 변형된 K-means 기반의 분석 프로세스)

  • Jung, Se Hoon;Shin, Chang Sun;Cho, Yong Yun;Park, Jang Woo;Park, Myung Hye;Kim, Young Hyun;Lee, Seung Bae;Sim, Chun Bo
    • Journal of Korea Multimedia Society
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    • v.20 no.12
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    • pp.1960-1969
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    • 2017
  • There have been ongoing researches to identify and analyze the patterns of electric power IoT data inside sensor nodes to supplement the stable supply of power and the efficiency of energy consumption. This study set out to propose an analysis process for electric power IoT data with the K-means algorithm, which is an unsupervised learning technique rather than a supervised one. There are a couple of problems with the old K-means algorithm, and one of them is the selection of cluster number K in a heuristic or random method. That approach is proper for the age of standardized data. The investigator proposed an analysis process of selecting an automated cluster number K through principal component analysis and the space division of normal distribution and incorporated it into electric power IoT data. The performance evaluation results show that it recorded a higher level of performance than the old algorithm in the cluster classification and analysis of pitches and rolls included in the communication bodies of utility poles.

Reliability Growth Planning for a Military System Using PM2-Continuous Model (예측방법론 기반 연속형 계획 모델을 적용한 무기체계의 신뢰도 성장 계획)

  • Seo, Yangwoo;Park, Eunshim;Kim, Youngkuk;Lee, Kwanyoung;Kim, Myungsoo
    • Journal of Applied Reliability
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    • v.18 no.3
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    • pp.201-207
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    • 2018
  • Purpose: To develop the reliability growth planning for a subsystem of guided weapon system using PM2-Continuous model. Methods: The target MTBF of the subsystem is set by allocating the system target MTBF to the lower level, where ARINC method is applied. Other model parameters such as initial MTBF, management strategy ratio and average fix effectiveness factor are chosen from historical growth parameter estimates. Given the values of model parameters, the reliability growth planning curve using PM2-Continuous model is constructed and the sensitivity analyses are performed for the changes of model parameters. Results: We have developed the reliability growth plan for a subsystem of guided weapon system using PM2-Continuous model. It was found that the smaller the ratio of initial MTBF to target MTBF, the smaller the management strategy ratio, the smaller the average fix effectiveness factor, and the shorter the development test period, the higher reliability growth is required. Conclusion: The result of this study will be used as a basis for establishing the reliability growth plan, the test period setting and the budget appropriation for the similar system entering the system development stage in the future.

Hypothesis Tests For Performances of a New Spline Interpolation Technique (신 스플라인보간법의 퍼포먼스 가설점정)

  • Yu, Ki-Yun
    • Journal of Korean Society for Geospatial Information Science
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    • v.7 no.1 s.13
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    • pp.29-40
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    • 1999
  • In vector GIS, natural linear entities (called linear entitles) are usually represented by a set of line segments. As an alternative of the line segments, curve segments can be used to represent the linear entities. The curve segments, as one-dimensional spatial objects, we generated by spline interpolation technique such as Bezier technique. In an effort to improve its accuracy in resembling the linear entities, the Bezier technique was modified generating a new technique (called New technique) (Kiyun, 1998). In this paper, validity of the New technique was tested. Test focused on answering two questions: (1) whether or not the curve segments from the New technique replace line segments so as to enhance the accuracy of representations of linear entities, and (2) whether or not the curve segments from the New technique represent the linear entities more accurately than curve segments from the Bezier technique. Answering these two questions entailed two hypothesis tests. For test data, a series of hydrologic lines on 7.5-minute USGS map series were selected. Test were done using t-test method and statistical inferences were made from the results. Test results indicated that curve segments from both the Bezier and New techniques represent the linear entities more accurately than the line segments do. In addition, curve segments from the New technique represent the linear entities more accurately than the line segments from the Bezier technique do at probability level 69% or higher.

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Multi-focus Image Fusion Technique Based on Parzen-windows Estimates (Parzen 윈도우 추정에 기반한 다중 초점 이미지 융합 기법)

  • Atole, Ronnel R.;Park, Daechul
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.4
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    • pp.75-88
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    • 2008
  • This paper presents a spatial-level nonparametric multi-focus image fusion technique based on kernel estimates of input image blocks' underlying class-conditional probability density functions. Image fusion is approached as a classification task whose posterior class probabilities, P($wi{\mid}Bikl$), are calculated with likelihood density functions that are estimated from the training patterns. For each of the C input images Ii, the proposed method defines i classes wi and forms the fused image Z(k,l) from a decision map represented by a set of $P{\times}Q$ blocks Bikl whose features maximize the discriminant function based on the Bayesian decision principle. Performance of the proposed technique is evaluated in terms of RMSE and Mutual Information (MI) as the output quality measures. The width of the kernel functions, ${\sigma}$, were made to vary, and different kernels and block sizes were applied in performance evaluation. The proposed scheme is tested with C=2 and C=3 input images and results exhibited good performance.

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An Exploratory Research on Categorizing e-Sports as One of the Sports (e스포츠의 스포츠 범주화에 대한 탐색적 연구)

  • Chae, Hee-Sang;Kang, Shin-Kyu
    • Journal of Korea Game Society
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    • v.11 no.3
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    • pp.85-95
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    • 2011
  • This paper focuses on the analysis of sports characteristics of e-Sports. For this purpose, it is important to set up a brand new concept of existing modern sports which is mainly concerned on physical activity. Therefore, In this paper, the researcher newly conceptualized e-Sports by following rapid change of the scene including media-technology, a change of an enjoyment method, the importance increase of sports environment and sports innovation. Also, the researcher tried to analyse how specific categorization of new sports concepts such as post-modern society, consumption & pleasure, homo-ludens, sporting experience, body and mind can be connected to e-Sports. As a result, e-Sports can be found in highly developed global society and consuming society. Furthermore, it can be defined as a 'brand new' concept of sports which features high level of psychological components in participation of activity.

A Study on Quantitative Risk Assessment Method and Risk Reduction Measures for Rail Hazardous Material Transportation (철도위험물수송에 관한 위험도 정량화방안 및 경감대책 연구)

  • Lee, Sang Gon;Cho, Woncheol;Lee, Tae Sik
    • Journal of Korean Society of societal Security
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    • v.1 no.3
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    • pp.69-76
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    • 2008
  • The object of this study is to develop a tool for quantifying risks related to the rail transportation of hazardous commodities and to present mitigation measures. In this study, the Quantitative Risk Assessment (QRA) is used as a risk analysis tool. Based on the previous explosion history (Iri explosion) and consideration of its high risk, Iksan-si is selected as a model city. The result, expressed as average individual risk for exposed people with various distance, indicates that the model city is considered to be safe according to the nuclear energy standard. Also, the mitigation measures are provided since Societal risk of Iksan-si is set within ALARP. Risk reduction measures include rail car design, rail transportation operation, demage spread control as well as derail prevention and alternative routes for reducing accident frequencies. Finally, it is expected to achieve high level of public safety by appling the risk reduction measures.

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Factors affecting the clinical competence of new nurses (신규간호사의 업무수행능력에 영향을 주는 요인)

  • Kim, Kyung- Hee;Kim, Sun-Mi;Kwon, Myoungjin
    • Journal of Industrial Convergence
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    • v.18 no.1
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    • pp.109-118
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    • 2020
  • Purpose: The purpose of this study was to investigate the effects of new nurse's resilience, emotional labor, and organizational socialization on clinical competence. Method: The subjects were 182 new nurses. The IBM SPSS 23.0 program was used for data analysis with the significance level set at .05. Results: Clinical competence was significantly different according to the number of nurses, hospitals where practiced, and nurse image (p <.05). Clinical competence showed a significant correlation with resilience (r = .50) and emotional labor (r = .62) (p <.001). Significant factors influencing clinical competence of new nurses were resilience(β = .567) and emotional labor(β = .332), with a total explanatory power of 50.5% (p <.001). Conclusion: There is a need for a program to improve the clinical competence of new nurses considering influencing factors.