• Title, Summary, Keyword: DETECT

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A Dimensionality Assessment for Polytomously Scored Items Using DETECT

  • Kim, Hae-Rim
    • Communications for Statistical Applications and Methods
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    • v.7 no.2
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    • pp.597-603
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    • 2000
  • A versatile dimensionality assessment index DETECT has been developed for binary item response data by Kim (1994). The present paper extends the use of DETECT to the polytomously scored item data. A simulation study shows DETECT performs well in differentiating multidimensional data from unidimensional one by yielding a greater value of DETECT in the case of multidimensionality. An additional investigation is necessary for the dimensionally meaningful clustering methods, such as HAC for binary data, particularly sensitive to the polytomous data.

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An Addressable Type Smoke Detect System Implementation to detect the Fire on a Ship (선박화재감지를 위한 Addressable Type Smoke Detect System 구현)

  • Kim, Tai-Suk;Kim, Jong-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.12
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    • pp.2543-2548
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    • 2011
  • The Smoke Detect System is setup to extinguish early a fire on the large ship like as the cargo ship and Bulk Carrier at sea. The Addressable Type Smoke Detect System that keeps the advantages and dispenses with the disadvantages of the existing conventional type system is composed of only one electrical cords. In this paper, we make the Smoke Detect System of an addressable type and implement to control it using ATmega Micro-controller and evaluate it.

A NEW INDEX OF DIMENSIONALITY - DETECT

  • Kim, Hae-Rim
    • The Pure and Applied Mathematics
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    • v.3 no.2
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    • pp.141-154
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    • 1996
  • A data-driven index of dimensionality for an educational or psychological test - DETECT, short for Dimensionality Evaluation To Enumerate Contributing Traits, is proposed in this paper. It is based on estimated conditional covariances of item pairs, given score on remaining test items. Its purpose is to detect whatever multidimensionality structure exists, especially in the case of approximate simple structure. It does so by assigning items to relatively dimensionally homogeneous clusters via attempted maximization of the DETECT over all possible item cluster partitions. The performance of DETECT is studied through real and simulated data analyses.

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A Refinement on DETECT for Polytomous Test Data

  • Kim, Hae-Rim
    • Communications for Statistical Applications and Methods
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    • v.13 no.3
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    • pp.467-477
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    • 2006
  • A multidimensionality detecting procedure DETECT, based on conditional covariances between items, is extended and refined to deal with polytomous item data as well as binary one. A large body of simulation study shows extraordinary performance of DETECT in both enumerating degrees of multidimensionality in a test and discovering dimensionally distinctive item clusters. Real data study also provides very meaningful results, making DETECT a strong dimensionality assessment tool for the test data analysis.

Comparison of Non-destructive Measuring Methods of Tomato Plant to Detect N, P and Ca Deficient Stresses (토마토 잎의 비파괴 계측에 의한 N, P, Ca 결핍 장해 진단법 비교)

  • 서상룡;류육성;정갑채;성제훈;이성희
    • Journal of Biosystems Engineering
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    • v.25 no.6
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    • pp.517-526
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    • 2000
  • A series of experiments was conducted to evaluate the capability of detecting nutrimental deficient stress of N, P and Ca of a tomato plant using several fast and intact type physiological properties measuring devices - a chlorophyll content meter an infra-red thermometer to measure leaf temperature a chlorophyll fluorescence meter a porometer an optical spectrometer a multi-scan radiometer and a canopy analyzer. to detect N deficient stress a chlorophyll content meter a spectrometer and a multi-scan radiometer were useful and their possibility to detect was estimated as about 50%, 100% and 100% respectively. To detect P deficient stress the infra-red thermometer the porometer and the spectrometer proved their usefulness an their possibility to detect was estimated as about 70%, 70% and 70% respectively. To detect Ca deficient stress an thermometer a porometer a spectrometer and a multi-scan radiometer were useful and their possibility to detect was estimated as about 60%, 70%,80% and 100% respectively. The experiments resulted that use of a spectrometer and a multi-scan radiometer in combination with a chlorophyll content meter an infra-red thermometer and a porometer were desirable to distinguish the nutrimental stress tested in the study.

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Factor analysis using S-detect Method in Breast Ultrasound (유방 초음파 검사 시 S-detect 방법을 활용한 인자 분석)

  • Chun, Hye Ri;Jang, Hyon Chol;Cho, Pyong Kon
    • Journal of the Korean Society of Radiology
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    • v.13 no.1
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    • pp.9-14
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    • 2019
  • This study aimed to investigate the performance of the S-detect method in breast ultrasonography and to determine how to reduce unnecessary biopsy by comparing the results of the S-detect method and biopsy. Thirty patients who had undergone breast ultrasonography between August and October 2018 and were scheduled to undergo biopsy because of the presence of breast nodules were retrospectively analyzed. The McNemar test was performed to determine whether detection of a malignant breast mass significantly differed between the S-detect method and biopsy. The following results were obtained from the analysis of the S-detect method: sensitivity, 90.9%; specificity, 84.21%; validity, 86.66%; positive predictive value, 76.92%; and negative predictive value, 94.11%. Analysis of the degree of agreement between the S-detect method and biopsy revealed a kappa value as high as 0.724 (p < 0.05), exhibiting good agreement between the two methods. The S-detect method in breast ultrasonography is diagnostically valuable in terms of distinguishing between malignant and benign breast masses, and if used properly before breast biopsy, unnecessary biopsy can be reduced.

Some Asymptotic Properties of Conditional Covariance in the Item Response Theory

  • Kim, Hae-Rim
    • Communications for Statistical Applications and Methods
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    • v.7 no.3
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    • pp.959-966
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    • 2000
  • A dimensionality assessment procedure DETECT uses the property of being near zero of conditional covariances as an indication of unidimensionality .This study provides the convergent properties to zero of conditional covariances when the dta is unidimensional, with which DETECT extends its theoretical grounds.

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Effects of Illumination and Target Size on Time-To-Detect while Recovering Dark Adaptation (암순응 환경에서 조도수준과 표적크기가 탐지시간에 미치는 영향)

  • Park, Jae-Kyu;Park, Sung-Ha;Oh, Hyun-Seung
    • Journal of the Ergonomics Society of Korea
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    • v.28 no.4
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    • pp.71-76
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    • 2009
  • Effects of dark adaptation have large safety implications. This study was aimed to investigate the effects of varying illuminance and the size of critical detail on visual performance (i.e., time-to-detect) in a dark room environment. While adapting to the dark environment, ten subjects were asked to detect and answer simple numerical expressions under 9 experimental conditions (3 illuminance level $\times$ 3 target size). The ANOVA results revealed that the time-to-detect was significantly affected by both of the illumination level and the size of critical detail. As illumination increased from 10 lux to 20 lux, the time-to-detect was significantly declined. For the size of critical detail, 0.5/min size (i.e., equal to 2 minutes of visual angle) resulted in a shorter time-to-detect, as compared to 0.7/min size (i.e., equal to 1.6 minutes of visual angle). Potential applications of this research include the development of design guidelines for illumination and warning signs in poorly illuminated viewing environments.

A Contactless Microwave Sensor for Detection of particular Materials (특정 물질 검출을 위한 비 접촉식 마이크로웨이브 센서)

  • Ki, Hyeon-Cheol
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.4
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    • pp.1-6
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    • 2012
  • We suggested a microwave sensor structure and fabricated experimentally to detect particular particles in the air which are difficult to detect using conventional UWB sensors because their reaction frequencies to electromagnetic waves are too high. In the experiment to detect water particles in the air with up-conversion frequency of 10GHz, we verified detect signal amplitude variation of 75% depending on presence or absence of water particles. The suggested structure can be useful to detect particular materials at the high frequencies more than a few 10th GHz, because the same method can be applied to detect other materials.

A Feature-Based Malicious Executable Detection Approach Using Transfer Learning

  • Zhang, Yue;Yang, Hyun-Ho;Gao, Ning
    • Journal of Internet Computing and Services
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    • v.21 no.5
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    • pp.57-65
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    • 2020
  • At present, the existing virus recognition systems usually use signature approach to detect malicious executable files, but these methods often fail to detect new and invisible malware. At the same time, some methods try to use more general features to detect malware, and achieve some success. Moreover, machine learning-based approaches are applied to detect malware, which depend on features extracted from malicious codes. However, the different distribution of features oftraining and testing datasets also impacts the effectiveness of the detection models. And the generation oflabeled datasets need to spend a significant amount time, which degrades the performance of the learning method. In this paper, we use transfer learning to detect new and previously unseen malware. We first extract the features of Portable Executable (PE) files, then combine transfer learning training model with KNN approachto detect the new and unseen malware. We also evaluate the detection performance of a classifier in terms of precision, recall, F1, and so on. The experimental results demonstrate that proposed method with high detection rates andcan be anticipated to carry out as well in the real-world environment.