• ETRI Journal
• /
• 제41권5호
• /
• pp.684-695
• /
• 2019

In a cloud environment, performance degradation, or even downtime, of virtual machines (VMs) usually appears gradually along with anomalous states of VMs. To better characterize the state of a VM, all possible performance metrics are collected. For such high-dimensional datasets, this article proposes a feature extraction algorithm based on unsupervised fuzzy linear discriminant analysis with kernel (UFKLDA). By introducing the kernel method, UFKLDA can not only effectively deal with non-Gaussian datasets but also implement nonlinear feature extraction. Two sets of experiments were undertaken. In discriminability experiments, this article introduces quantitative criteria to measure discriminability among all classes of samples. The results show that UFKLDA improves discriminability compared with other popular feature extraction algorithms. In detection accuracy experiments, this article computes accuracy measures of an anomaly detection algorithm (i.e., C-SVM) on the original performance metrics and extracted features. The results show that anomaly detection with features extracted by UFKLDA improves the accuracy of detection in terms of sensitivity and specificity.

• 국제학술발표논문집
• /
• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
• /
• pp.7-11
• /
• 2011

Quantity take-off (QT) is one of the most important tasks for determining the total cost of a construction project, and it requires accuracy and reliability for the result. Accuracy and reliability in BIM-based QT are also required to assure the completeness of the result. However, there has been no basis to measure the completeness of the BIM-based QT result. As BIM is increasingly being adopted in the construction industry with a wide variety of purposes, it becomes more important to have a method to improve the completeness of BIM-based QT and criteria to measure it. This research focuses on the hypothesis that the completeness of BIM-based QT relies on the accuracy and reliability of BIM and the BIM-based QT process. As a basic research to determine the completeness of BIM-based QT, this research analyzes and derives factors that affect the completeness of BIM-based QT.

• 한국대기환경학회지
• /
• 제31권2호
• /
• pp.157-163
• /
• 2015

To establish National Reference Method (NRM) for $PM_{2.5}$, operational performance of 5 different commercial gravimetric-based $PM_{2.5}$ measuring instruments was assessed at Bulkwang monitoring station from January 23, 2014 to February 28, 2014. First, physical properties, design, and functional performance of the instruments were assessed. Evaluation was carried out to determine whether operating method for the instruments and levels of QA/QC activities meet the data quality objectives (DQOs). To verify whether DQOs were satisfied, reproducibility of QA/QC procedures, accuracy, relative sensitivity, limit of detection, margin of error, and coefficient of determination of the instruments were also evaluated. Results of flow rate measurement of 15 candidate instruments indicated that all the instruments met performance criteria with accuracy deviation of 4.0% and reproducibility of 0.6%. Comparison of final $PM_{2.5}$ mass concentrations showed that the coefficient of determination ($R^2$) values were greater than or equal to 0.9995, and concentration gradient ranged from 0.97 to 1.03. All the instruments satisfied criteria for NRM with the estimated precision of 1.47~2.60%, accuracy of -1.90~3.00%, and absolute accuracy of 1.02~3.12%. This study found that one particular type of measuring instrument was proved to be excellent, with overall evaluation criteria satisfied.

• 대한기계학회논문집B
• /
• 제23권3호
• /
• pp.398-407
• /
• 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.

• 한국환경과학회지
• /
• 제20권9호
• /
• pp.1095-1104
• /
• 2011

A survey of professionals employed in marine related fields was conducted on subjects related to marine meteorological forecasts and special reports. The outcome of the survey indicated that the respondents were overall satisfied with the determination of the zones related to marine meteorological forecasts and special reports and with the number of forecast factors, but in regards to the questions about specific adjustment methods, it was found that the respondents perceived a need for adjustment. In addition, although there was a high consensus among the respondents that the criteria for watch and warning in the marine special reports were suitable, they voiced the opinion that it will be necessary to implement changes in the current criteria for watch and warning in order to further improve the compatibility of the criteria. The survey found that there was a high level of utilization for the marine meteorological information provided by the Korea Meteorological Administration(KMA), and that respondents mostly acquired this information via internet and TV. On the other hand, however, the satisfaction level regarding the accuracy of the marine meteorological information was low in comparison to the utilization level. The survey regarding areas for improvement in the forecasts and special reports also indicated that the need for 'improvement in the accuracy of forecasts' was cited most frequently.

• Journal of Radiation Protection and Research
• /
• 제41권3호
• /
• pp.274-281
• /
• 2016

Background: Whole-body counters are widely used to evaluate internal contamination of the internal presence of gamma-emitting radionuclides. In internal dosimetry, it is a basic requirement that quality control procedures be applied to verify the reliability of the measured results. The implementation of intercomparison programs plays an important role in quality control, and the accuracy of the calibration and the reliability of the results should be verified through intercomparison. In this study, we evaluated the reliability of 2 whole-body counting systems using 2 calibration methods. Materials and Methods: In this study, 2 whole-body counters were calibrated using a reference male bottle manikin absorption (BOMAB) phantom and a Radiation Management Corporation (RMC-II) phantom. The reliability of the whole-body counting systems was evaluated by performing an intercomparison with International Atomic Energy Agencyto assess counting efficiency according to the type of the phantom. Results and Discussion: In the analysis of counting efficiency using the BOMAB phantom, the performance criteria of the counters were satisfied. The relative bias of activity for all radionuclides was -0.16 to 0.01 in the Fastscan and -0.01 to 0.03 in the Accuscan. However, when counting efficiency was analyzed using the RMC- II phantom, the relative bias of $^{241}Am$ activity was -0.49 in the Fastscan and 0.55 in the Accuscan, indicating that its performance criteria was not satisfactory. Conclusion: The intercomparison process demonstrated the reliability of whole-body counting systems calibrated with a BOMAB phantom. However, when the RMC-II phantom was used, the accuracy of measurements decreased for low-energy nuclides. Therefore, it appears that the RMC-II phantom should only be used for efficiency calibration for high-energy nuclides. Moreover, a novel phantom capable of matching the efficiency of the BOMAB phantom in low-energy nuclides should be developed.

• 한국콘텐츠학회논문지
• /
• 제20권10호
• /
• pp.45-56
• /
• 2020

본 연구는 '시뮬레이션 정부연습'(가칭)에서 연습 실시자의 조치사항을 평가하기 위한 척도에 관한 연구이다. 평가척도의 지표와 지표별 가중치는 조치사항으로 입력한 기관별 data를 평가하는 기준이 된다. 이것은 평가의 객관성과 일관성을 유지하여 관찰평가관의 주관적인 평가를 보완하게 된다. 그래서 평가지표는 정부연습 평가 목적, 시뮬레이션 환경에서의 측정 가능성, 객관성, 지표간의 중복성과 인과성, 평가결과를 적용하는 등급 등을 검토하여 선정하고, 각 지표는 상대적 중요도가 설정돼야 한다. 본 연구에서는 적시성·정확성·적절성의 3개 주요 지표와 주요 지표별로 각 3개의 등급 지표를 설정하고 지표별 개념을 구분하였다. 지표의 가중치는 지표의 계층구조를 고려하여 AHP 분석으로 산정하였다. 향후 연구서의 평가척도가 '시뮬레이션 정부연습'에 적용되면 정량적인 평가를 통하여 조치 평가의 일관성과 객관성을 확보할 수 있을 것이고 과학적인 기법에 의한 사후검토(AAR)가 가능할 것이다.

• 한국문헌정보학회지
• /
• 제39권2호
• /
• pp.123-146
• /
• 2005

이 연구에서는 문서 자동분류에서 분류자질 선정과 가중치 할당을 위해서 일관된 전략을 채택하여 kNN 분류기의 성능을 향상시킬 수 있는 방안을 모색하였다. 문서 자동 분류에서 분류자질 선정 방식과 자질 가중치 할당 방식은 자동분류 알고리즘과 함께 분류성능을 좌우하는 중요한 요소이다. 기존 연구에서는 이 두 방식을 결정할 때 상반된 전략을 사용해왔다. 이 연구에서는 색인파일 저장공간과 실행시간에 따른 분류성능을 기준으로 분류자질 선정 결과를 평가해서 기존 연구와 다른 결과를 얻었다. 상호정보량과 같은 저빈도 자질 선호 기준이나 심지어는 역문헌빈도를 이용해서 분류 자질을 선정하는 것이 kNN 분류기의 분류 효과와 효율 면에서 바람직한 것으로 나타났다. 자질 선정기준으로 저빈도 자질 선호 척도를 자질 선정 및 자질 가중치 할당에 일관되게 이용한 결과 분류성능의 저하 없이 kNN 분류기의 처리 속도를 약 3배에서 5배정도 향상시킬 수 있었다.

• 한국건설관리학회:학술대회논문집
• /
• 한국건설관리학회 2003년도 학술대회지
• /
• pp.521-524
• /
• 2003

최근 현장에서는 공사관리의 효율화를 위한 여러 가지 공사관리 시스템을 적용하고 있으며, 이를 통하여 현장의 실적자료를 수집하고 있다. 하지만 이러한 노력에도 불구하고 실적자료의 바탕이 되는 현장 데이터는 객관적 수집 또는 기준에 의해서 이루어지는 것이 아니라 주관적 판단 또는 측정자별로 상이한 기준에 의해 이루어져 각 현장별로 큰 차이가 발생하고 있다. 이러한 문제를 해결하고자 최근 모바일 기술의 발전을 활용한 현장의 데이터 수집을 위한 여러 가지 방안이 연구되고 있으며, 데이터의 체계화에 대한 필요성이 제기되고 있다. 따라서 본 연구는 공종별 특성에 따른 진도 측정 단위 도출 방안을 제안하고, MS Access를 활용한 Prototype의 진도 측정단위 생성 시스템을 개발하였다. 마지막으로, 제안된 도출 방안과 시스템 및 체계는 측정된 데이터의 객관성 및 정확성을 높임으로서, 현장별로 표준화된 진도측정을 가능하게 할 것이다.

• Genomics & Informatics
• /
• 제5권4호
• /
• pp.143-151
• /
• 2007

To understand the mechanism of transcriptional regulation, it is essential to detect promoters and regulatory elements. Various kinds of methods have been introduced to improve the prediction accuracy of regulatory elements. Since there are few experimentally validated regulatory elements, previous studies have used criteria based solely on the level of scores over background sequences. However, selecting the detection criteria for different prediction methods is not feasible. Here, we studied the calibration of thresholds to improve regulatory element prediction. We predicted a regulatory element using MATCH, which is a powerful tool for transcription factor binding site (TFBS) detection. To increase the prediction accuracy, we used a regulatory potential (RP) score measuring the similarity of patterns in alignments to those in known regulatory regions. Next, we calibrated the thresholds to find relevant scores, increasing the true positives while decreasing possible false positives. By applying various thresholds, we compared predicted regulatory elements with validated regulatory elements from the Open Regulatory Annotation (ORegAnno) database. The predicted regulators by the selected threshold were validated through enrichment analysis of muscle-specific gene sets from the Tissue-Specific Transcripts and Genes (T-STAG) database. We found 14 known muscle-specific regulators with a less than a 5% false discovery rate (FDR) in a single TFBS analysis, as well as known transcription factor combinations in our combinatorial TFBS analysis.