• Title/Summary/Keyword: Internal Defects

Search Result 517, Processing Time 0.026 seconds

Erosion behavior according to location of conduit cracks in agricultural reservoir

  • Ryu, Jung-Hyun;Heo, Joon;Shim, Jae-Woong;Kim, Cheol-Han;Yun, Bora;Lee, Yong-Hak;Lee, Dal-Won
    • Korean Journal of Agricultural Science
    • /
    • v.47 no.4
    • /
    • pp.1159-1168
    • /
    • 2020
  • The conduits of agricultural reservoirs undergo deterioration over a considerable period of time and this is highly likely to cause structural problems such as cracks. It is therefore important to consider the effects of structural defects on the body from the viewpoint of stability and maintenance of the embankment. In this study, basic data on the effects of the crack location on the stability of the embankment is obtained by identifying, comparing, and analyzing the erosion characteristics and pore water pressure behavior through a large-scale model experiment that involves classifying the location of the conduit cracks. From the results of the experiment, it was confirmed that when a crack occurred, the amount of leakage increased as the location of the crack portion was closer to the water level, and the internal erosion phenomenon accelerated, thereby increasing the possibility of piping. It was also found that an upstream conduit crack affects the erosion and water pressure change of the central and downstream conduit of the embankment, and the conduit crack has a very large effect on the pore water pressure despite the low upstream water level. Therefore, the seepage behavior of the embankment for each conduit crack identified in this study is considered to be useful basic data for preparing a repair and reinforcement plan according to the crack location in the future.

Analysis of Defect Signals Inside Glass Fiber Reinforced Polymer Through Deconvolution of Terahertz Wave (테라헤르츠파의 디컨벌루션을 통한 유리섬유 복합재 내부 결함 신호 분석)

  • Kim, Heon-Su;Park, Dong-Woon;Kim, Sang-Il;Lee, Jong-Min;Kim, Hak-Sung
    • Composites Research
    • /
    • v.35 no.1
    • /
    • pp.8-12
    • /
    • 2022
  • Analysis of defect signals inside glass fiber reinforced polymer (GFRP) was conducted through deconvolution of terahertz (THz) wave. The GFRP specimen with internal defects was manufactured and the THz signal was measured through the reflection mode of the Terahertz Time-Domain Spectroscopy (THz-TDS) system. For deconvolution of the measured THz signal, the peak position of the THz signal was amplified through Normalized Cross Correlation (NCC) of the incident and detected THz signals. The position and intensity of the amplified peak were extracted as impulse, and the extracted signal of the impulse position was removed from the THz original signal. By repeating the process, the critical impulses, which represent boundary of the specimen, were derived. The deconvolution process was verified by confirming that the original THz signal without noise can be restored through the convolution of the critical impulses and the incident signal. From the derived critical impulses, the thickness of the internal defect in the GFRP was calculated through the detection time of impulses within 15 ㎛ accuracy.

Development of Diagnosis Application for Rail Surface Damage using Image Analysis Techniques (이미지 분석기법을 이용한 레일표면손상 진단애플리케이션 개발)

  • Jung-Youl Choi;Dae-Hui Ahn;Tae-Jun Kim
    • The Journal of the Convergence on Culture Technology
    • /
    • v.10 no.2
    • /
    • pp.511-516
    • /
    • 2024
  • The recently enacted detailed guidelines on the performance evaluation of track facilities presented the necessary requirements regarding the evaluation procedures and implementation methods of track performance evaluation. However, the grade of rail surface damage is determined by external inspection (visual inspection), and there is no choice but to rely only on qualitative evaluation based on the subjective judgment of the inspector. Therefore, in this study, we attempted to develop a diagnostic application that can diagnose rail internal defects using rail surface damage. In the field investigation, rail surface damage was investigated and patterns were analyzed. Additionally, in the indoor test, SEM testing was used to construct image data of rail internal damage, and crack length, depth, and angle were quantified. In this study, a deep learning model (Fast R-CNN) using image data constructed from field surveys and indoor tests was applied to the application. A rail surface damage diagnosis application (App) using a deep learning model that can be used on smart devices was developed. We developed a smart diagnosis system for rail surface damage that can be used in future track diagnosis and performance evaluation work.

The Non-destructive Inspection Using Infrared Thermal Technique on Reinforced Slopes by Shotcrete (적외선 열화상을 이용한 숏크리트 보강사면의 비파괴점검)

  • Shin, Chang-Gun;Lee, Song;Ahn, Sang-Ro
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.11 no.1
    • /
    • pp.95-102
    • /
    • 2007
  • It needs to Prevent damage as aging shotcrete itself exists as a dangerous component to comuting vehicles or infrastructure due to scaling, spaling, and loosening. However, it is hard to make an approach owing to a steep slope and high work, and there has been indicated a limit that it is difficult to grasp the internal condition of shotcrete on the surface. This study aimed to research internal defects that cannot be observed from the surface, by measuring a subtle thermal transfer on the shotcrete surface by using infrared thermography for overcoming such a technical limit. As a result of conducting an inspection through an analysis on measured data and fieldwork using an endoscope camera, it was impossible to accurately determine the wet part because of an excessive coating of shotcrete, yet, This study is proposed effictively extract a void part of the inside with non-destructive and non-touching method.

Study about the Association between Diabetes and the Targeted SNPs of TCF7L2 and FTO Genes (당뇨병에서 TCF7L2와 FTO 유전자의 특정 단일염기다형성과의 연관성 연구)

  • Hsia, Yu-Chun;Park, Jong-Hyung;Jun, Chan-Yong;Ko, Seung-Gyu;Choi, You-Kyung
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.24 no.3
    • /
    • pp.504-511
    • /
    • 2010
  • Diabetes is a disease that contains a high concentration of glucose in blood and due to defects in either insulin secretion or insulin action. Although the distinctive causes and factors of diabetes have not been clarified, the genetic factors are suggested as a main susceptibility until now. SNP (Single Nucleotide Polymorphism), as the most common genetic variation, has an influence on personal susceptibility for diseases. A nonsynonymous SNP, which changes the amino acid of the protein and its function, is especially important. Therefore, this study hypothesized that there are associations between specific SNPs of the targeted genes. Transcription factor 7-like 2 (TCF7L2) and fat mass and obesity associated (FTO) genes were selected as target genes from the results of genome-wide association and other related research studies. Second, four nonsynonymous SNPs (three in TCF7L2 and one in FTO gene) were selected as target SNPs by using public database of NCBI (National Center for Biotechnology Information). The recruited personnel was classified into three subgroups of diabetes, impaired fasting glucose (IFG) and normal groups. The individual genotypes of each group were analyzed by resequencing. None of genetic variations at four targeted SNP sites was revealed in all samples of this study. However, this study found two new SNPs that were not reported in TCF7L2 gene. One is synonymous SNP, which is heterozygous of C/T and no amino acid change of asparagine/asparagines, was located at c1641 and found in one normal person. Another is nonsynonymous SNP, which is heterozygous of G/A, was located at c1501 and found in two samples. This new discovered nonsynonymous SNP induce the amino acid change from alanine to threonine. Moreover, this new nonsynonymous SNP was found among two persons, one of whom was a diabetes patient and the other one was a person at boundary between IFG and normal, suggesting that this variant might be associated with IFG or diabetes. Even if there is a limitation of sample number for statistical power, this study has an importance due to the discovery of new SNPs. In the future study, a large sample number of diabetes cohort will be needed to investigate the frequency and association with new discovered SNP.

Internal Growth Type Character and Popular Sympathy of Heroic Narrative (영웅서사의 내적 성장형 캐릭터와 대중적 공감형성 - 마블과 DC의 시네마틱 유니버스를 기반으로 -)

  • Jeon, Yeongdon
    • The Journal of the Korea Contents Association
    • /
    • v.20 no.1
    • /
    • pp.364-377
    • /
    • 2020
  • Although it is never easy to create charming characters that people can relate to, well-formed characters have the power to enable the audience to not only empathize but identify with them. Thus, there is a need for us to examine the parts that make up a well-formed character. According to empathy theory, when the character in the play has a human face that is not different from me, I can feel familiarity and human empathy. Rather than perfection without loopholes, I relate to and sympathize with someone who looks similar to me, with many mistakes and some lack. This study aims to examine the attractiveness of characters in narrative dramas in terms of defects and internal growth. To do this, we tried to compare the setting, evaluation, and performance of characters based on the movie worldviews of two famous brands (DC and Marble), which can be compared directly. I looked at it. In conclusion, the work of hero character but human character setting based on internal growth not only has high evaluation and public evaluation, but also high sales, and thus direct and indirect correlation with the public favorability is significant.

Recent Studies of Breast Cancer in Traditional Chinese Medicine Journals (중의학 논문에 나타난 유방암의 연구 동향에 대한 고찰 - 중의학 논문을 중심으로 -)

  • Jerng, Ui-Min;Jeong, Jong-Soo;Park, Jae-Woo;Jung, Hyun-Sik;Yoon, Seong-Woo
    • The Journal of Korean Obstetrics and Gynecology
    • /
    • v.22 no.1
    • /
    • pp.263-278
    • /
    • 2009
  • Purpose: The purpose of this study is to research trends in the study of breast cancer in Traditional Chinese Medicine (TCM) and to establish the further direction for its study. Methods: We reviewed TCM papers published in the last 29 years (1979-2008). Results: 1. We researched 49 papers and the patterns of study were as follows: in vitro studies were 27 papers (55.1%), in vivo studies were 9 papers (18.4%) and clinical studies were 19 papers (38.8%). 2. In vitro studies on breast cancer research in TCM were focused on cytotoxicity (17 papers) and apoptosis (8 papers). Most of in vivo studies (6 papers) were done for the purpose of inducing growth suppression of tumor cell after administration of the test drug. Each drug acted on this effect through various types of mechanism. 3. Unlike in vitro and in vivo studies, clinical studies on growth suppression of tumor cell were rare (4 papers). Most of the studies were focused on reduction of side effect of chemotherapy or synergistic effect with chemotherapy (7 papers), immune regulation (7 papers), and improvement of quality of life (6 papers). 4. Among the treatment method we reviewed, 'Runing Ⅱ(Ⅱ號方)' was the only medication that further studied as clinical trial after experimental study. 5. Since almost all studies have defects like poorly designed model or insufficient data description, it was difficult to make any definite conclusion about these studies. Conclusion: More subsequent clinical studies based on experimental study will be needed afterwards. Strict and high-level study design with detailed description will be needed in further study.

A Study on the Technology Measuring Partial Discharge for Long Term Aging Experiments of Insulation Materials (장시간 절연체 열화실험을 위한 부분방전측정기술 연구)

  • Seon, Jong-Ho;Kim, Gwang-Hwa;Park, Jeong-Hu;Jo, Jeong-Su
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.49 no.12
    • /
    • pp.665-672
    • /
    • 2000
  • This paper described the measurement technology to analyze the partial discharge characteristics for long term aging of insulations. This system was consisted of high voltage generation and measurement part, PD detection part, digital conversion and signal processing part. We used the VXI system for digital conversion and signal processing part. In the digital conversion part, we studied the error of partial discharge magnitude and memory capacity for reading digital signal with the sampling rate. In the signal processing part, we showed the program algorithm to count pulses and read peak values of partial discharge. The allowable minimum sampling rate of digizer was decided to 250kS/s through analyzing test. We confirmed that this system was very useful in the study of $\phi-q-n$ characteristics of long term PD experiments with specimens being consisted of internal void defects and CIGRE II electrodes.

  • PDF

Development of ultra-high frequency (UHF) ultra-wide bandwidth signal processing unit for UHF partial-discharge monitoring system for gas-insulated switchgears (가스절연개폐장치용 부분방전 감시 시스템을 위한 초광대역 극초단파 신호처리장치 개발)

  • Choi, Jae-Ok;Kim, Young-No;Lee, Young-Sang;Gang, Chang-Won;Park, Ki-Jun;Goo, Sun-Geun;Yoon, Jin-Yul;Koo, Jae-Yoon
    • Proceedings of the KIEE Conference
    • /
    • 2004.07c
    • /
    • pp.1963-1966
    • /
    • 2004
  • An ultra wide band ultra-high frequency (UHF) signal processing module was designed for on-line UHF partial discharge (PD) monitoring systems for gas-insulated switchgears (GIS). Major advantage of the unit is an improved PD detection sensitivity through minimizing the effect of surrounding interference signals. The detection sensitivity of the unit was <-60 dBm that is sufficient to detect UHF PD signals as low as 1 pC. Precise detection of PD occurred in the GIS, due to internal defects, is possible by using the signal processing unit.

  • PDF

Classification of Defects in Rotary Compressor by Neural Pattern Recognition of Acoustic Emission Signal (AE신호의 신경망 형상인식법에 의한 로터리 압축기의 결함 분류에 관한 연구)

  • Lee, K.Y.;Lee, C.M.;Hwang, I.B.;Kim, Y.W.;Hong, J.K.
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.18 no.1
    • /
    • pp.17-26
    • /
    • 1998
  • The specimen with the wear between a roller and a vane and a normal specimen are classified by AE signal pattern recognition method with a neural network classifier in airconditioning operation test. Also the specimen with the scoring between a shaft and a bearing and a normal specimen are classified by the same method. As the internal pressure increases, the wear between the roller and the vane increases. The different pairs of oils and refrigerants five the effect on the wear.

  • PDF