• Title/Summary/Keyword: decay detection

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Effect of Brown-rotted Wood on Mechanical Properties and Ultrasonic Velocity

  • Lee, Sang-Joon;Kim, Gyu-Hyeok;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.5
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    • pp.24-32
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    • 2008
  • Artificial brown-rot decay was induced to two wood species, Pinus densiflora and Pinus radiata. A modified direct inoculation method was used and the decay indicators of mass loss and two compressive mechanical properties, maximum compressive strength (MCS) and compressive stiffness, were estimated over the period of 8 weeks of fungal exposure. Measurable mass loss occurred 2 weeks after the fungal attack, with 15% to 22% of the loss occurring 8 weeks after fungal exposure with Fornitopsis palustris and Gloeophyllurn trabeurn. Mechanical properties proved to be far more sensitive than mass loss detection: approximately five to six times by quantity. Of the two mechanical properties, MCS was more sensitive to and consistent with progressive brown-rot decay. An ultrasonic test was performed to determine the feasibility and accuracy of this method for nondestructive detection of brown-rot decay. The ultrasonic test is highly sensitive at qualitative detection of the early stages of brown-rot decay.

Novel Optimizer AdamW+ implementation in LSTM Model for DGA Detection

  • Awais Javed;Adnan Rashdi;Imran Rashid;Faisal Amir
    • International Journal of Computer Science & Network Security
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    • v.23 no.11
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    • pp.133-141
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    • 2023
  • This work take deeper analysis of Adaptive Moment Estimation (Adam) and Adam with Weight Decay (AdamW) implementation in real world text classification problem (DGA Malware Detection). AdamW is introduced by decoupling weight decay from L2 regularization and implemented as improved optimizer. This work introduces a novel implementation of AdamW variant as AdamW+ by further simplifying weight decay implementation in AdamW. DGA malware detection LSTM models results for Adam, AdamW and AdamW+ are evaluated on various DGA families/ groups as multiclass text classification. Proposed AdamW+ optimizer results has shown improvement in all standard performance metrics over Adam and AdamW. Analysis of outcome has shown that novel optimizer has outperformed both Adam and AdamW text classification based problems.

Performance of 3D printed plastic scintillators for gamma-ray detection

  • Kim, Dong-geon;Lee, Sangmin;Park, Junesic;Son, Jaebum;Kim, Tae Hoon;Kim, Yong Hyun;Pak, Kihong;Kim, Yong Kyun
    • Nuclear Engineering and Technology
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    • v.52 no.12
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    • pp.2910-2917
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    • 2020
  • Digital light processing three-dimensional (3D) printing technique is a powerful tool to rapidly manufacture plastic scintillators of almost any shape or geometric features. In our previous study, the main properties of light output and transmission were analyzed. However, a more detailed study of the other properties is required to develop 3D printed plastic scintillators with expectable and reproducible properties. The 3D printed plastic scintillator displayed an average decay time constants of 15.6 ns, intrinsic energy resolution of 13.2%, and intrinsic detection efficiency of 6.81% for 477 keV Compton electrons from the 137Cs γ-ray source. The 3D printed plastic scintillator showed a similar decay time and intrinsic detection efficiency as that of a commercial plastic scintillator BC408. Furthermore, the presented estimates for the properties showed good agreement with the analyzed data.

Real time gait analysis using acceleration signal (가속도 신호를 이용한 실시간 보행 분석)

  • Kang, G.T.;Park, K.T.;Kim, G.R.;Choi, B.C.;Jung, D.K.
    • Journal of Sensor Science and Technology
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    • v.18 no.6
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    • pp.449-455
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    • 2009
  • In this paper, we developed a digital gait analyzer using the triaxial accelerometer(TA). An approach for normal gait detection employing decay slope peak detection(DSPD) algorithm was presented. The TA was attached to the center of the waist of a subject. The subject walked a bare floor at 60, 92 and 120 steps/minute. We analyzed vertical axis acceleration signal for gait detection. At 60, 92, 120 steps/minute walking, detection accuracy of gait events were over 99 % accuracy.

Assessment of Incipient Decay of Radiata Pine Wood Using Stress-Wave Technique in the Longitudinal Direction (수축방향(樹軸方向) 응력파(應力波) 방법(方法)에 의(依)한 라디에타소나무의 초기부후(初期腐朽) 평가(評價))

  • Kim, Gyu-Hyeok;Jee, Woo-Kuen;Ra, Jong-Bum
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.2
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    • pp.1-6
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    • 1996
  • This study was performed to investigate the feasibility of using sonic stress-wave technique in the longitudinal direction for the assessment of incipient decay of radiata pine wood. Decayed bending specimens by Tyromyces palustris and Gloeophyllum trabeum for varoious periods were tested nondestructively using stress-wave technique in the longitudinal direction and destructively. Decay detection, quantitative assessment of decay, and the prediction of residual strength of decayed wood with less than five percent weight loss can be feasible using stress-wave parameters (wave velocity, wave impedance, stress-wave elasticity) measured by stress-wave technique in the longitudinal direction and their percent reduction due to decay.

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Assessment of Incipient Decay of Radiata Pine Wood Using Stress-wave Technique in the Transverse Direction (횡단방향(橫斷方向) 응력파(應力波) 방법(方法)에 의(依)한 라디에타소나무의 초기부후(初期腐朽) 평가(評價))

  • Kim, Gyu-Hyeok;Jee, Woo-Guen;Ra, Jong-Bum
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.3
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    • pp.18-27
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    • 1996
  • The feasibility of using stress-wave technique in the transverse direction for the assessment of early stages of decay was investigated using compression test specimens having different annual ring orientations subjected to decay by Tyromyces palustris for various time intervals. Decay detection, quantitative assessment of decay, and the prediction of residual strength of decayed wood with less than five percent weight loss can be feasible using stress-wave parameters (wave velocity, wave impedance, and stress-wave elasticity) and their percent reduction due to decay, measured by stress-wave technique in the transverse direction. The use of stress-wave technique in the transverse direction for the application of this technique to structural members in service is desirable, when considering the easiness of attachment of accelerometers of stress-wave measuring device on the surface of members and also accurate detection of localized decayed areas. In stress-wave technique in the transverse direction, stress-wave parameters measured were different according to the angles between wave propagation path and annual ring, due to the anisotropy of wood structure. Therefore, it is recommended to use percent reduction in stress-wave parameters instead of stress-wave parameters. This evaluation method using percent reduction in stress-wave parameters is ideal when it is impossible to observe annual ring orientation on the transverse surface of wood.

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Wood decay Detection by Non-destructive Methods (비파괴 방법을 이용한 목재의 부후 탐지)

  • Son, Dong-Won;Lee, Dong-Heub
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.4
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    • pp.74-81
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    • 2004
  • The ultrasonic non-destructive method was used for wood decay test. The temperature change and moisture contents of wood were estimated how the ultrasonic wave velocity changes. The relationship between weight loss of wood decayed by T. palustris and ultrasonic wave velocity was investigated. The non-destructive methods of different condition of logwood were estimated. Decay map of old wood was made by non destructive methods. Through these tests, we can accumulate the data to judge the degree of wood decay. The decay map of wood could be used for the analysis of old wood.

The Dharma of Nonsense-Mediated mRNA Decay in Mammalian Cells

  • Popp, Maximilian Wei-Lin;Maquat, Lynne E.
    • Molecules and Cells
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    • v.37 no.1
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    • pp.1-8
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    • 2014
  • Mammalian-cell messenger RNAs (mRNAs) are generated in the nucleus from precursor RNAs (pre-mRNAs, which often contain one or more introns) that are complexed with an array of incompletely inventoried proteins. During their biogenesis, pre-mRNAs and their derivative mRNAs are subject to extensive cis-modifications. These modifications promote the binding of distinct polypeptides that mediate a diverse array of functions needed for mRNA metabolism, including nuclear export, inspection by the nonsense-mediated mRNA decay (NMD) quality-control machinery, and synthesis of the encoded protein product. Ribonucleoprotein complex (RNP) remodeling through the loss and gain of protein constituents before and after pre-mRNA splicing, during mRNA export, and within the cytoplasm facilitates NMD, ensuring integrity of the transcriptome. Here we review the mRNP rearrangements that culminate in detection and elimination of faulty transcripts by mammalian-cell NMD.

Detection of Decay Leaf Using High-Resolution Satellite Data (고해상도 위성자료를 활용한 마른 잎 탐지)

  • Sim, Suyoung;Jin, Donghyun;Seong, Noh-hun;Lee, Kyeong-sang;Seo, Minji;Choi, Sungwon;Jung, Daeseong;Han, Kyung-soo
    • Korean Journal of Remote Sensing
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    • v.36 no.3
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    • pp.401-410
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    • 2020
  • Recently, many studies have been conducted on the changing phenology on the Korean Peninsula due to global warming. However, because of the geographical characteristics, research on plant season in autumn, which is difficult to measure compared to spring season, is insufficient. In this study, all leaves that maple and fallen leaves were defined as 'Decay leaves' and decay leaf detection was performed based on the Landsat-8 satellite image. The first threshold value of decay leaves was calculated by using NDVI and the secondary threshold value of decay leaves was calculated using by NDWI and the difference of spectral characteristics with green leaves. POD, FAR values were used to verify accuracy of the dry leaf detection algorithm in this study, and the results showed high accuracy with POD of 98.619 and FAR of 1.203.

Comparison of Blue Luminescence Between Spark-processed Photoluminescian Silicon and Ambient Air Aged Anodically Etched Porous Silicon

  • Chang, Sung-Sik;Yoon, Sang-Ok
    • The Korean Journal of Ceramics
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    • v.2 no.3
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    • pp.137-141
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    • 1996
  • Ambient air aged anodically etched porous silicon (PS) and spark-processed silicon (sp-Si) show interesting similarities and dissimilarities in some of their luminescence-related properties. Among these similarties are: (1) the photoluminescence (PL) peak maximum in the blue/violet (410 nm);(2) the blue/violet PL peak positions are essentially unchanged with temperature ; (3) PL decay times in the nanosecond region which are independent of the detection wavelength, which is much faster in decay times compared to that of observed decay time in $SiO_2$.Among the dissimilarities are: (1) the PL intensity of blue/violet luminescence, namely, the PL intensity of sp-Si is at least 2 orders of magnitude larger than that of an ambient air aged PS; (2) the blue/violet PL intensity of sp-Si is more stable than that of ambient air aged PS under UV illuminations; (3) FTIR spectra of sp-Si favor those modes, which involve silicon -oxygen bonds in $SiO_2$ stoichiometry, whereas ambient air aged PS can be considered as a nonstoichiometric oxide judging from the observed vibrational spectra.

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