• Tunnel and Underground Space
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• v.20 no.2
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• pp.105-111
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• 2010

This study is to consider applicability of spiral bolt strain gauge as an instrument measuring behavior of soft ground foundation and rock slope. When the instrument was installed on the ground, it can be useful to identify the state of ground behavior because it has the characteristics of flexibility, as well as to apply the ground reinforcement because it has higher pull-out resistance to the ground. From the measurement of behavior to soft ground foundation, the strain shows a stable state in the beginning, then was observed significant change in the upper and the middle of spiral bolt strain gauge after 400 days. This is analyzed that ground loosening, which is due to occurred frequent earthquake of magnitude 1~2 with increased rainfall, lead to the instability of the ground. From the measurement of behavior to rock slope, the strain shows a stable state with very little change in a period of 0~50 days and the biggest strain at 4.2 m (P6) in a period of 50~100 days, then other places except P6 was maintained at a stable state in a period of 100~160 days. The reason is analyzed because that blasting for excavated limestone surrounding was affected to the largest at P6. However, based on the size of strain change by behavior of the soft ground foundation and rock slope, it is considered that the present condition are not effected on stability of retaining structure and rock slope. In conclusion, the proposed spiral bolt strain gauge can be useful to measure behavior of soft ground foundation and rock slope, and also to be measured behavior as well as reinforcement of the target ground.

• Journal of Life Science
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• v.12 no.1
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• pp.49-54
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• 2002

Development of a rapid method possessing the requisite sensitivity and specificity for virus monitoring is necessary for protection of the shellfish-consuming public. Oysters tissue usually contains virus particles in relatively small concentrations along with various other substances that can interfere with detection steps. Therefore, the critical point concerning the detection of viruses in shellfish tissues resides in the processing of samples. The current study demonstrated the possibility of purifying small amounts of virus particles at the interface of a 10/50% sucrose gradient after a single round of sucrose gradient ultracentrifugation. We could detect HAV and poliovirus simultaneously from oyster tissues by using two different sets of primer. Furthermore, the method showed a high level of virus recovery rate (>95%) as determined by plaque assays of the final samples. Taken the advantages of the simple and sensitive methods, it was possible to detect 2 pfu of HAV in 5 g of oyster digestive tissues within 24h.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.60-67
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• 2014

The comparisons between cellulolytic bacteria adhesion on rice straw and fiber digestion in time course during rumen fermentation were studied in situ. The adhesions of cellulolytic bacteria, F. succinogenes. R. albus and R. flavefaciens, were measured by RT-PCR. When the rice straws were incubated at 0. 2, 4, 8, 12 and 24 hours of the in situ rumen, straw was degraded with increasing speed during the incubation and showed the highest disappearance increasing rate (DM g/h) from 8 to 12 hour. The adhesions of F. succinogenes, R. flavefaciens and R. albus were achieved above 80% in 1 hour of in situ rumen fermentation and then keep adhesive population up after the time of fermentation. When the in situ samples were collected at 0, 5, 10, 30 and 60 min to detect the early stages of adhesion on the rice straws ingested into rumen, the numberous adhesive colony of F. succinogenes, R. flavefaciens and R. albus were detected in 5 min. In case of rice straw treated with 0, 2, 4 and 8% NaOH, all of three cellulolytic bacteria showed the increasing trends of adhesion with increasing DM disappearance of rice straw by higher concentration of NaOH at 12 hour of in situ. However, there were showed respectively difference at 24 hour. The present results gave certain evidence that adhesion of cellulolytic bacteria is definitely achieved in early stage of roughage ingestion into rumen, their colony develop the stable communities on roughage in process of rumen fermentation and then fiber degradation is accelerated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.702-708
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• 2016

The railway signaling system has evolved to maximize its safety and maintainability based on the experiences in the construction and operation of railway systems. The newly developed systems was established to cope with the changes in an operating environment. In the process of a transition to the new system, both the existing ATS (Automatic Train Stop) and new ATP/ATO (Automatic Train Protection/Automatic Train Operation) systems are operating simultaneously in parallel. In this situation, modifications of the conditions of the interlocking diagram and logic are necessarily required on the existing ATS systems due to the frequent improvements in signaling equipment. This paper reports the enhancement of safety and operational efficiency of the system through an improvement of the security and the interlocking conditions of the existing ATS systems. The independent display of signals for each track was ensured to avoid giving the effect of On/Off signals for the selected track on the opposite side, and the security was improved by adjusting the position and interlocking conditions. In addition, the increased traffic density of railway systems was achieved by removing the unnecessary conditions and detailed signal display, which resulted in enhanced operational efficiency.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.421-430
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• 2019

In this study, 195 pesticide residues in fruit samples (n=150) at local markets in Chungcheongnam-do Chungnam, Korea were monitored using a multi-residue method combined with GC-MS/MS and LCMS/MS. Among 150 fruit samples, 40 types of pesticides were detected in 63 samples and the detection rate was 42.0%. However, the amounts were below the maximum residue limit (MRL). Detection rates for pesticides in each thpe of fruit were as follows ; citrus fruits (55.2%), pome fruits (41.3%), berries (38.7%) and stone fruits (36.0%). Although the sample size was small (n=2), pesticide residues were not detected in tropical fruits. Occurrences of detection of pesticide residues in apple showed the highest level, and mainly, insecticides were detected most frequently. The most commonly detected pesticides residues were bifenthrin (21), pyraclostrobin (17), novaluron (13), boscalid (10), chlorfenapyr (9), trifloxystrobin (9), furathiocarb (9), acetamiprid (8) and chlorpyrifos (8). Five types of residual pesticides (bifenthrin, chlorfenapyr, deltamethrin, fenpropathrin and fenvalerate) were detected in quince, and out of these five, fenpropathrin exceeded the MRL based on the Positive List System (PLS). These results suggested that pesticide residues in fruit samples should be continuously monitored, although residue levels in 63 other fruit samples were evaluated as being within a safe level.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.359-366
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• 2021

This study aimed to develop and verify the smart human resource management (HRM) program in a large scale greenhouse. HRM program delivers detailed work orders to workers and gathers work results by mobile phone application. Greenhouse managers can monitor the workload, work speed, quality of employee by HRM program and can analyse performance easily. Greenhouse Managers can set the work speed including 'twisting', 'trimming' and 'harvesting' in a greenhouse. It makes planning work schedule and assigns resources to each specific job easier. Therefore, the manager can arrange the number of employees to promote work performance and also easy to estimate the labor shortage. Greenhouse managers can evaluate the adequacy of the number of employees through job performance analysis by period and adjusts the supply/demand ratio of regular and non-regular employees. The HRM program can improve work efficiency by announcing the real-time work performance of all employees on a monitor screen to induce competition among workers and re-educate unripe employees who accomplish behind average to improving work skills.

• Korean Journal of Remote Sensing
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• v.37 no.6_3
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• pp.1931-1942
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• 2021

As the utility of an optical satellite image with a high spatial resolution (i.e., fine-scale) has been emphasized, recently, various studies of the land surface monitoring using those have been widely carried out. However, the usefulness of fine-scale satellite images is limited because those are acquired at a low temporal resolution. To compensate for this limitation, the spatiotemporal data fusion can be applied to generate a synthetic image with a high spatio-temporal resolution by fusing multiple satellite images with different spatial and temporal resolutions. Since the spatio-temporal data fusion models have been developed for mid or low spatial resolution satellite images in the previous studies, it is necessary to evaluate the applicability of the developed models to the satellite images with a high spatial resolution. For this, this study evaluated the applicability of the developed spatio-temporal fusion models for KOMPSAT-3A and Sentinel-2 images. Here, an Enhanced Spatial and Temporal Adaptive Fusion Model (ESTARFM) and Spatial Time-series Geostatistical Deconvolution/Fusion Model (STGDFM), which use the different information for prediction, were applied. As a result of this study, it was found that the prediction performance of STGDFM, which combines temporally continuous reflectance values, was better than that of ESTARFM. Particularly, the prediction performance of STGDFM was significantly improved when it is difficult to simultaneously acquire KOMPSAT and Sentinel-2 images at a same date due to the low temporal resolution of KOMPSAT images. From the results of this study, it was confirmed that STGDFM, which has relatively better prediction performance by combining continuous temporal information, can compensate for the limitation to the low revisit time of fine-scale satellite images.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.81-87
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• 2019

In this study, synthetic methods and physical properties for a new class of glycidyl azide polymer (GAP) were investigated for energetic thermoplastic elastomers (ETPE). Four kinds of GAP copolymer polyols were synthesized by introducing nucleophiles such as azide, alkoxide and alkyl amine into poly(epichlorohydrin) (PECH). The GAP copolymer synthetic reaction can be evaluated as an environmental benign and efficient synthetic method due to the simultaneous one-step reaction using two kinds of nucleophiles and the complete consumption of sodium azide. The relative stoichiometric substitution ratio analysis and the progress of reaction were checked and monitored by inverse gated decoupled $^{13}C$ NMR and Fourier transform infrared (FT-IR) spectroscopy. The glass transition temperature and molecular weight were measured by differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) analysis. The synthesized poly($GA_{0.8}-butoxide_{0.2}$), poly($GA_{0.7}-n-butylamine_{0.3}$), poly($GA_{0.7}-dipropylamine_{0.3}$) and poly($GA_{0.7}-morpholine_{0.3}$) had a glass transition temperature ranged from -39 to $-26^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.58-64
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• 2019

In the current study, 109 commercial nut samples were collected from different Korean markets and analyzed for the contamination of 5 different mycotoxins (aflatoxin, ochratoxin A, deoxynivalenol, zearalenone, and T-2 toxin) using ELISA kits. The results revealed that the most frequently detected mycotoxin was zearalenone (n=36, 33%), followed by aflatoxin (n=31, 28.4%) and ochratoxin A (n=30, 27.5%). Deoxynivalenol and T-2 toxin were also detected in 22 (20.3%) samples, respectively. Among 109 nut samples, 33 samples (30.3%) were contaminated only with one kind of mycotoxin, whereas 43 samples had at least 2 kinds of mycotoxins. Two samples were contaminated with as many as 4 different mycotoxins, and they were both walnuts. Although the monitoring results revealed the amount of aflatoxin contamination was under the safety criteria, there is no current safety guideline for other kinds of mycotoxins or multiple contaminations in Korea. Therefore, further studies should be performed to reveal the distribution of mycotoxin in different foods and propose appropriate safety guidelines for Korean markets.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.3
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• pp.419-432
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• 2019

Most of deep learning model training was proceeded by supervised learning, which is to train labeling data composed by inputs and corresponding outputs. Labeling data was directly generated manually, so labeling accuracy of data is relatively high. However, it requires heavy efforts in securing data because of cost and time. Additionally, the main goal of supervised learning is to improve detection performance for 'True Positive' data but not to reduce occurrence of 'False Positive' data. In this paper, the occurrence of unpredictable 'False Positive' appears by trained modes with labeling data and 'True Positive' data in monitoring of deep learning-based CCTV accident detection system, which is under operation at a tunnel monitoring center. Those types of 'False Positive' to 'fire' or 'person' objects were frequently taking place for lights of working vehicle, reflecting sunlight at tunnel entrance, long black feature which occurs to the part of lane or car, etc. To solve this problem, a deep learning model was developed by simultaneously training the 'False Positive' data generated in the field and the labeling data. As a result, in comparison with the model that was trained only by the existing labeling data, the re-inference performance with respect to the labeling data was improved. In addition, re-inference of the 'False Positive' data shows that the number of 'False Positive' for the persons were more reduced in case of training model including many 'False Positive' data. By training of the 'False Positive' data, the capability of field application of the deep learning model was improved automatically.