• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.303-309
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• 2018

Internet of Things technology is an intelligent service that connects all objects to the Internet and interacts with them. It is a technology that can be used in various fields, such as device management, process management, monitoring of restricted areas for industrial systems, as well as for navigation in military theaters of operation. However, because all devices are connected to the Internet, various attacks using security vulnerabilities can cause a variety of damage, such as economic loss, personal information leaks, and risks to life from vulnerability attacks against medical services or for military purposes. Therefore, in this paper, a mutual authentication method and a key-generation and update system are applied by applying S/Key technology based on a hash chain in the communications process. A mutual authentication method is studied, which can cope with various security threats. The proposed protocol can be applied to inter-peer security communications, and we confirm it is robust against replay attacks and man-in-the-middle attacks, providing data integrity against well-known attacks in the IoT environment.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.12
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• pp.525-534
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• 2023

Gas leak detection system is a key to minimize the loss of life due to the explosiveness and toxicity of gas. Most of the leak detection systems detect by gas sensors or thermal imaging cameras. To improve the performance of gas leak detection system using single-modal methods, the paper propose multimodal approach to gas sensor data and thermal camera data in developing a gas type identification model. MultimodalGasData, a multimodal open-dataset, is used to compare the performance of the four models developed through multimodal approach to gas sensors and thermal cameras with existing models. As a result, 1D CNN and GasNet models show the highest performance of 96.3% and 96.4%. The performance of the combined early fusion model of 1D CNN and GasNet reached 99.3%, 3.3% higher than the existing model. We hoped that further damage caused by gas leaks can be minimized through the gas leak detection system proposed in the study.

• Journal of Aerospace System Engineering
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• v.18 no.3
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• pp.41-47
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• 2024

Recently, as the practical application and commercialization of unmanned aerial vehicles (UAVs) is pursued, interest in ensuring the safety of the UAV is increasing. Because UAV accidents can result in property damage and loss of life, it is important to develop technology to prevent accidents. For this reason, a technique to detect the abnormal flight state of UAVs has been developed based on the AutoEncoder model. However, the existing detection technique is limited in terms of performance and real-time processing. In this paper, we propose a U-Net based abnormal flight detection technique. In the proposed technique, abnormal flight is detected based on the increasing rate of Mahalanobis distance for the reconstruction error obtained from the U-Net model. Through simulation experiments, it can be shown that the proposed detection technique has superior detection performance compared to the existing detection technique, and can operate in real-time in an on-board environment.

• Structural Engineering and Mechanics
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• v.74 no.6
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• pp.789-807
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• 2020

Multiple earthquakes that occur during short seismic intervals affect the inelastic behavior of the structures. Sequential ground motions against the single earthquake event cause the building structure to face loss in stiffness and its strength. Although, numerous research studies had been conducted in this research area but still significant limitations exist such as: 1) use of traditional design procedure which usually considers single seismic excitation; 2) selecting a seismic excitation data based on earthquake events occurred at another place and time. Therefore, it is important to study the effects of successive ground motions on the framed structures. The objective of this study is to overcome the aforementioned limitations through testing a two storey RC building structural model scaled down to 1/10 ratio through a similitude relation. The scaled model is examined using a shaking table. Thereafter, the experimental model results are validated with simulated results using ETABS software. The test framed specimen is subjected to sequential five artificial and four real-time earthquake motions. Dynamic response history analysis has been conducted to investigate the i) observed response and crack pattern; ii) maximum displacement; iii) residual displacement; iv) Interstorey drift ratio and damage limitation. The results of the study conclude that the low-rise building model has ability to resist successive artificial ground motion from its strength. Sequential artificial ground motions cause the framed structure to displace each storey twice in correlation with vary first artificial seismic vibration. The displacement parameters showed that real-time successive ground motions have a limited impact on the low-rise reinforced concrete model. The finding shows that traditional seismic design EC8 requires to reconsider the traditional design procedure.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.39-46
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• 1989

The tracheobronchial histopathologic findings in 7 healthy cats used with high frequency oscillation ventilation (HFOV) were compared with those in 6 cats used with conventional mechanical ventilation (CMV). 4-point, 9-variable scoring system was used to evaluate the injury in the trachea, right & left main bronchi and parenchyme. The following results were obtained ; 1) The tracheobronchial tree received HFOV had no significant damage compared with CMV (P>0.05). 2) Intraepithelial mucus loss and emphysema were s lightly more prominent in CMV groups. As above results ; the tracheobronchial histopathologic difference was not prominent between CMV and HFOV groups received with relatively short period, however, the cellular function and barotrauma may be more prominent in CMV groups. From now on, as causes of tracheobronchial injury in HFV, interaction between humidification and mechanical trauma considers further study.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.219-228
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• 2006

In urban areas, tunnelling induced ground deformations, particularly ground settlements should be considered in order to minimize the damage of adjacent structures. Therefore, an appropriate monitoring system for the tunnel construction should be setup at the planning or design stage. A number of studies on ground settlements due to tunnelling in soft ground have been carried out so far. However, most studies have focused on clay soil rather than sand soil. In particular, a few studies on behaviour of subsurface deformations in granular material have been reported. In this study, two-dimensional laboratory model test with aluminium rods regarded as continuum granular material and close range photogrammetric technique, and numerical analysis were carried out in order to identify the behaviour of subsurface deformations due to shallow tunnelling. Direction and magnitude of displacement vectors from the model test was identical to the numerical analysis. In particular, the vector direction was appeared to be toward a point below the tunnel invert level. A narrow 'chimney or tulip like' pattern of vertical displacement was confirmed by both the model test and numerical analysis. This is consistent with the field data. In addition to the qualitative comparison, the quantitative comparison of subsurface settlements according to 2D volume loss showed good agreement between the model test and numerical analysis. Therefore, close range photogrammetric technique applied in the model test may be used to validate the result from the continuum numerical analysis.

• Korean Journal of Acupuncture
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• v.23 no.4
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• pp.147-156
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• 2006

Objectives : The purpose of the present study is to evaluate the effects of herbal acupuncture with Ginseng Radix for the treatment to intestinal disease in the rat with 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) induced colitis. Methods : All animals were subjected to the injection of saline $(300{\mu}{\ell},\;500{\mu}{\ell})$ for a study control or TNBS $(300{\mu}{\ell},\;500{\mu}{\ell})$ into the lumen of the colon, 8cm proximal to the anus through the intestine. Ginseng Radix herbal acupuncture ($20mg/m{\ell},\;0.4m{\ell}$) were injected to the both $Hapgok(LI_4)$ acupoints at 2nd injection of TNBS in rats. Thus, the body weight, RBC count, WBC count, total protein, IgG levels and IgM levels were observed to study the effects of Ginseng Radix herbal acupuncture. Results : Ginseng Radix herbal acupuncture on $Hapgok(LI_4)$ for TNBS-induced colitis inhibited the body weight loss rate but did not affect RBC and WBC counts. Furthermore, it inhibited the reduction of total protein concentration and serum IgG and IgM levels in TNBS induced colitis were recovered. Conclusions : Herbal acupuncture with Ginseng Radix helps recover the TNBS-induced colonic damage and may be an important method for treatment of the colitis.

• IMMUNE NETWORK
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• v.6 no.1
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• pp.13-19
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• 2006

Background: Granulocyte colony stimulating factor (G-CSF) is known as a cytokine central to the hematopoiesis of blood cells and to modulate their cellular functions. Besides granulocytes and their precursors, monocytes/macrophages and endothelial cells are direct target cells of G-CSF action. G-CSF influences immune cells in an anti inflammatory way. Methods: To evaluate whether G-CSF has a potential for preventing or ameliorating diseases characterized by mucosal inflammation, we used a mouse model with trinitrobenzene sulfonic acid (TNBS)-induced inflammatory colitis. To the mice model G-CSF was administrated daily by intraperitoneal injection. Macroscopic evaluation and immunohistochemical analysis of colonic tissues were performed. Results: Re combinant human G-CSF significantly inhibited LPS-induced TNF-${\alpha}$ mRNA expression in THP-1 cells. As for in vivo relevance, G-CSF dramatically reduced the weight loss of mice, colonic damage, and mucosal ulceration that characterize TNBS colitis. Moreover, G-CSF suppressed the expression of tumor necrosis factor-${\alpha}$, interleukin-$1{\beta}$, and intercellular adhesion molecule-1 in TNBS colitis. Conclusion: Current results demonstrate that G-CSF may be an effective agent for the treatment of diseases characterized by mucosal inflammation.

• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.413-422
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• 2013

This study evaluated the fire safety code elements through analyze the loss of life when the fire occurred in the facility sprinklers installed evaluated. And through comparison with national fire safety code elements and standards of NFPA 13 in the United States, Was looking for ways to improve for Life and property damage. In the United States, in some cases, if you do not install the sprinkler are installed as per the fire death rate compared to 83 % lower. By contrast, If the domestic rate of 280 % fatalities were 3.37 times than the United States. This lack of fire performance were analyzed uniform occupancy classification, the amount of source of water supply, live not consider the density according to the standard number and the horizontal distance that causes the installation of sprinkler facilities were analyzed.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.415-424
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• 2020

This study investigated the effects of an ethylene scrubber (ES) with a micro-perforated polypropylene (MP-PP, 30 ㎛) or a high density polyethylene (MP-HDPE, 30 ㎛) film liner for the export carton packaging box in 'Campbell Early' grapes. Rachis browning was highest in the untreated group, followed by MP-PP and MP-HDPE for 14 days of simulated marketing at 20℃. The combination treatment of ES with the film liners showed a partial inhibition of the rachis browning regardless of the film liners. The effects of an alcohol releaser (AR) sachet or chlorine dioxide (CD) diffuser co-packaging were also investigated in the 'Campbell Early' grapes packed with the MP-HDPE (40 × 99 pin hole·m^-2) film liner. The CD 1 g treatment showed a very limited weight loss of 1.1%, which was significantly lower than the 4.7% of the untreated control after 14 days of simulation marketing at 20℃. The berry shatter was 0.7% for the MP-HDPE + CD 1 g treatment and 1.8% for the MP-HDPE + CD 5 g treatment on the 10th day of the simulated marketing, which was significantly lower than the 8.9% of the control. The stem browning was significant suppressed until the 10th day of the simulated marketing. In particular, the CD 1 g treatment in combination with the MP-HDPE showed a low rachis and pedicel browning index of 2.0, which is 50% and 40% lower than that of the untreated control and the MP-HDPE single treatment, respectively. In addition, the CD 1 g treatment group showed a higher decay reduction effect than the CD 5 g treatment group, which caused high concentration damage.