• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.8
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• pp.2688-2703
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• 2022

Research on the advanced detection of harmful objects in airport cargo for passenger safety against terrorism has increased recently. However, because associated studies are primarily focused on the detection of relatively large objects, research on the detection of small objects is lacking, and the detection performance for small objects has remained considerably low. Here, we verified the limitations of existing research on object detection and developed a new model called the Small Hazardous Object detection enhanced and reconstructed Model based on the You Only Look Once version 5 (YOLOv5) algorithm to overcome these limitations. We also examined the performance of the proposed model through different experiments based on YOLOv5, a recently launched object detection model. The detection performance of our model was found to be enhanced by 0.3 in terms of the mean average precision (mAP) index and 1.1 in terms of mAP (.5:.95) with respect to the YOLOv5 model. The proposed model is especially useful for the detection of small objects of different types in overlapping environments where objects of different sizes are densely packed. The contributions of the study are reconstructed layers for the Small Hazardous Object detection enhanced and reconstructed Model based on YOLOv5 and the non-requirement of data preprocessing for immediate industrial application without any performance degradation.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.7-14
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• 2013

In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods for various foods. The analysed samples consist of 11 items including dried fruits (6 items) and mushrooms (5 items). To compare between non-irradiated and irradiated food, all samples were irradiated with $^{60}Co$ gamma-ray source. In PSL study, the photon counts of all the unirradiated sample were identified negative (lower than 700). The photon counts irradiated (1, 5, 10 kGy) dried date-palm, dried jujube and mushrooms (Auricularia auricula, Phellinus linteus and Sarcodon aspratus) showed positive (higher than 5,000) and the results for the other samples were negative or intermediate (>700 and >5,000). In TL analysis most of items can be applicable to detect irradiated foods because of showing TL ratio above 0.1. The glow curves by TL method were estimated in the range of $150{\sim}250^{\circ}C$ in irradiated samples. In ESR measurements, the intensity of ESR signal (single-line) increased as the dose of irradiation increased. In particular, the specific ESR signals of irradiation-induced radical were detected in dried papaya, dried date-palm, dried banana, dried pineapple and S. aspratus. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and ESR methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.120-125
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• 2014

Conventional handheld metal detectors use a single induction coil to detect the metallic parts of explosive objects, and the detector generates an acoustic signal from its magnetic response to a metallic object so that an operator can confirm the existence of mines. Though metal detectors have very useful detection mechanisms to find mines, it is easy to cause a high false alarm ratio due to the detection of non-explosive metallic items such as cans, nails and other pieces of metal, etc. Also, because of the physical characteristic of a metal detector it is hard to detect non-metallic objects such as mines made of wood or plastic. Furthermore, the operator must move it to the left and right slowly and repeatedly to attain enough sensor signals to confirm the existence of mines using only a monotonous acoustic signal. To resolve the disadvantages of handheld detectors, many new approaches have been attempted, such as an arrayed detector and a visualization algorithm based on metal/non-metal sensor. In this paper, we introduce a visualization algorithm with a metal/non-metal complex sensor, an arrayed metal/non-metal sensor and the their testing and evaluation.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.31-37
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• 2014

Since the unprecedented hydrogen fluoride leak accident in 2012, there has been growing demand for customized technical information for rapid response and chemical accident management agencies including the Ministry of Environment, the National Emergency Management Agency, and the National Police Agency need more information on chemicals and accident management. In this regard, this study aims to provide reliable technical data and guidelines to initial response agencies, similar to accident management technical reports of the US and Canada. In this study, we conducted a questionnaire survey and interviews on initial response agencies like fire stations, police stations, and local governments to identify new information items for appropriate initial response and improvements of current guidelines. We also collected and reviewed the Canada's TIPS, US EPA's hydrogen fluoride documents, domestic and foreign literature on applicability tests of control chemicals, and interview data, and then produced items to be listed in the technical guidelines. In addition, to establish database of on-site technical information, we carried out applicability tests for accident control data including ① emergency shut down devide, safety guard, shut down valve, ground connection, dyke, transfer pipe, scrubber, and sensor; ② literature and field survey on distribution type and transportation/storage characteristics (container identification, valve, ground connection, etc.); ③ classification and identification of storage/transportation facilities and emergency management methodslike leak prevention, chemicals control, and cutoff or bypass of rain drainage; ④ domestic/foreign analysis methods and environmental standards including portable detection methods, test standards, and exposure limits; and ⑤ comparison/evaluation of neutralization efficiency of control chemicals on toxic substances.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.399-404
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• 2016

The applicability of photostimulated-luminescence (PSL) and thermoluminescence (TL) for the detection of 12 food materials (potato, onion, garlic, dried pumpkin, black mushroom, black soybean, Cheongkukjang powder, sea mustard, pepper powder, Ramyun soup, corn tea, and green tea powder) irradiated with an electron beam, gamma ray, and X ray at a range of 0.15 to 10 kGy was investigated. For PSL, negative results (less than 700 photon counts (PCs)) were observed from non-irradiated foods while the irradiated foods showed intermediate (879 to 2,414 PCs) and/or positive (19,951 to 65,919,035 PCs) values. In all irradiated samples, the maximum peak of the TL glow curve was observed between 150 and $250^{\circ}C$. Our findings demonstrate the successful application of PSL and TL to determine whether food items were irradiated or not. However, there were no significant differences among the radiation sources.

• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.176-184
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• 2017

Objectives: Excluding in their homes, children spend most of their time at an elementary school, daycare center, and/or kindergarten. For educational or recreational purposes, they make use of many children's goods at these places. Some children's goods contain phthalates and heavy metals with polyvinyl chloride (PVC), so due to their physiological and behavioral characteristics children are exposed to high concentrations of phthalates and heavy metals. This study aims to measure PVC and heavy metals, which are harmful substances in children's goods which can have an effect on children's health. Methods: Six samples of children's goods were selected through cases of detected harmful substances and the results of previous research, including assembly blocks, model toys, household toys, bags, indoor play equipment, and floor mats. The selected items were measured using X-Ray Fluorescence (XRF), and the presence and content of environmentally harmful substances such as PVC or heavy metals in the materials of children's goods were examined. Results: The highest detection rate for PVC was observed in floor mats, and bags and indoor play equipment were higher than other goods in this regard. The highest detection rate for heavy metals was found in bags, followed by indoor play equipment, assembly blocks, household toys, model toys and floor mats. Except for bags containing heavy metals, five goods showed the highest level of Pb compared to other heavy metals. Floor mats contained the highest level of Pb, Cr, and Cu among all goods. Conclusion: Many children's goods contain PVC and heavy metals, and high levels of heavy metals have been detected in some goods. It is necessary to manage children's goods to support their health.

• Journal of Food Hygiene and Safety
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• v.25 no.1
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• pp.65-72
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• 2010

We used fluorescence detector to analyse total aflatoxins (G1, G2, B1, B2) with TFA (Trifluoroacetic acid) derivation method and PHRED (Photochemical reactor enhanced detection) method. PHRED method was superior in reproduction and convenience, but TFA derivation method was superior in selectivity and sensitivity. The recovery rate of aflatoxin B1, B2, G1 were more than 80%, and G2 was more than 70%. The detection limit of B1, B2, G1 and G2 were respectively 0.05, 0.05, 0.2 and $0.1\;{\mu}g/kg$. Confirmed method was used to analyse total aflatoxins in total 316 items as 9 kinds 137 dried fruits and 10 kinds 179 spices. By the result, Aflatoxins were detected in 27 dried fruits (19.7%) and in 87 spices (48.6%).