356 research outputs found
Creating Jobs by Social Enterprises in Korea: Lessons and Experiences
This paper aims to examine the possibility that jobs for young graduates may be created through social enterprises at local level, in particular, and to highlight the important factors affecting job creation by social enterprises. After identifying potentially relevant features of social enterprises being operated in Korea, we put forward the ways in which jobs can be created particularly for young graduates Extrapolating research findings from extensive interviews and participant observation at business meetings, we conclude the existence of job-creation pattern that operates within distinctive institutional environments. The article emphasizes the importance of historical and institutional traditions in framing available pathways of job creation by social enterprises in Korea
A design of a short course with COTS UAV system for higher education students
This paper aims to propose a short course with a commercial off the shelf unmanned aerial vehicle (COTS UAV) system. From the short course, students can have a conception of a UAV system, and they would have not only the knowledge about the hardware integration but also the theoretical background of the guidance, navigation, and control (GNC) and the situation awareness system. The proposed course consists of two parts; the GNC system for holding the position and the situation awareness system with the marker detection and tracking. A Pixhawk is selected for a flight controller with an open source autopilot, i.e. px 4, and a Raspberry Pi with a downward camera is utilised for the visual navigation of the situation awareness system. The Pixhawk and Raspberry Pi are integrated into the robot operating system (ROS) via the WIFI network, and the MAVROS is adopted for the communication between the Pixhawk and the Raspberry Pi. The first part of the course is designed as the hands-on based lectures, and the second part of the course is adopted the problem-based project
Target Detection, Tracking and Avoidance System for Low-cost UAVs using AI-Based Approaches
An onboard target detection, tracking and avoidance system has been developed
in this paper, for low-cost UAV flight controllers using AI-Based approaches.
The aim of the proposed system is that an ally UAV can either avoid or track an
unexpected enemy UAV with a net to protect itself. In this point of view, a
simple and robust target detection, tracking and avoidance system is designed.
Two open-source tools were used for the aim: a state-of-the-art object
detection technique called SSD and an API for MAVLink compatible systems called
MAVSDK. The MAVSDK performs velocity control when a UAV is detected so that the
manoeuvre is done simply and efficiently. The proposed system was verified with
Software in the loop (SITL) and Hardware in the loop (HITL) simulators. The
simplicity of this algorithm makes it innovative, and therefore it should be
used in future applications needing robust performances with low-cost hardware
such as delivery drone applications.Comment: IEEE RED-UAS 2019 Conferenc
Retrieval of NO2 Column Amounts from Ground-Based Hyperspectral Imaging Sensor Measurements
Total column amounts of NO2 (TCN) were estimated from ground-based hyperspectral imaging sensor (HIS) measurements in a polluted urban area (Seoul, Korea) by applying the radiance ratio fitting method with five wavelength pairs from 400 to 460 nm. We quantified the uncertainty of the retrieved TCN based on several factors. The estimated TCN uncertainty was up to 0.09 Dobson unit (DU), equivalent to 2.687 ?? 1020 molecules m???2) given a 1?? error for the observation geometries, including the solar zenith angle, viewing zenith angle, and relative azimuth angle. About 0.1 DU (6.8%) was estimated for an aerosol optical depth (AOD) uncertainty of 0.01. In addition, the uncertainty due to the NO2 vertical profile was 14% to 22%. Compared with the co-located Pandora spectrophotometer measurements, the HIS captured the temporal variation of the TCN during the intensive observation period. The correlation between the TCN from the HIS and Pandora also showed good agreement, with a slight positive bias (bias: 0.6 DU, root mean square error: 0.7 DU)
Neuroprotective Activity of Sibjeondaebo-tang on Aβ Peptide-Induced Damages
Background. Sibjeondaebo-tang (SJDBT) has been used to treat diverse disorders including neuropsychiatric disabilities in traditional Korean medicine.
Objective. The present study aims to investigate the potential effects of SJDBT on neuroprotection against Aβ peptide-induced damage using in vitro culture and in vivo rat brain systems. Materials and Methods. PC12 cell viability was analyzed by MTT assay, and neurite arborizations and caspase 3 protein signals in cultured PC12 cells and in vivo cortical neurons were analyzed by immunofluorescence staining. Phospho-Erk1/2 protein was analyzed by immunofluorescence staining and western blot analysis. Results. In PC12 cells, atrophied cell body and reduced neurite extension by Aβ treatment were recovered by SJDBT treatment. Caspase 3 protein signals were increased in Aβ-treated PC12 cells, but SJDBT treatment decreased apoptotic cell death. Caspase 3 activation in cortical neurons, which was induced similarly by Aβ treatment, was reduced by SJDBT treatment. Furthermore, phospho-Erk1/2 protein levels, which had been decreased by Aβ treatment, were elevated in the cortical neurons by SJDBT treatment. Conclusion. These data show that SJDBT may play a role in protecting from damages induced by Aβ in neuronal tissue and further suggest that SJDBT can be explored as the potential therapeutic target for AD treatments in human
M3FPolypSegNet: Segmentation Network with Multi-frequency Feature Fusion for Polyp Localization in Colonoscopy Images
Polyp segmentation is crucial for preventing colorectal cancer a common type
of cancer. Deep learning has been used to segment polyps automatically, which
reduces the risk of misdiagnosis. Localizing small polyps in colonoscopy images
is challenging because of its complex characteristics, such as color,
occlusion, and various shapes of polyps. To address this challenge, a novel
frequency-based fully convolutional neural network, Multi-Frequency Feature
Fusion Polyp Segmentation Network (M3FPolypSegNet) was proposed to decompose
the input image into low/high/full-frequency components to use the
characteristics of each component. We used three independent multi-frequency
encoders to map multiple input images into a high-dimensional feature space. In
the Frequency-ASPP Scalable Attention Module (F-ASPP SAM), ASPP was applied
between each frequency component to preserve scale information. Subsequently,
scalable attention was applied to emphasize polyp regions in a high-dimensional
feature space. Finally, we designed three multi-task learning (i.e., region,
edge, and distance) in four decoder blocks to learn the structural
characteristics of the region. The proposed model outperformed various
segmentation models with performance gains of 6.92% and 7.52% on average for
all metrics on CVC-ClinicDB and BKAI-IGH-NeoPolyp, respectively.Comment: 5pages. 2023 IEEE International Conference on Image Processing
(ICIP). IEEE, 202
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Session D5: Current Status of Fish Passages in South Korea
Abstract:
Weirs are important for countries that agriculture is the primary industry due to the stable supply of water to agricultural fields. Because agriculture is still important in Korean peninsula, weirs have been constructing until now from small streams to large rivers. However, only limited fish passages were installed in weirs, and there were no managements. As a results, streams and rivers have become highly fragmented, with fish migration being severely impeded. Thus, ministry of agriculture, food and rural affairs investigated entire fish passages in Korea in 2010-2011, and estimated current status and problems. A total of 33,718 weirs were installed (until year 2012), and this means that weirs are arithmetically located every 0.81km of the total stream length in Korea. Fish passages, however, were constructed only in 4,496 weirs (13.3% of installation rate). The weir type fish passages with Ice- Harbor type fishways (8.1%) which are favoured nowadays was showed the greatest number (36%), and the vertical slot type passages was in the second place (31%). The denil type and nature-like type were rarely installed. Only 18.1% of installed fish passages were left whole, and urgent repair is needed for 56.7%. Fish passages of 31.3% were incorporated into the recommended slope range of Korea (1:20). Most of problems are related discharge, poor entrance, breakage and sedimentation. With these structural problems, discontinuous installation of fish passages generates poor continuity of streams. Currently, to improve stream connectivity many projects from Korean government are now conducting and preparing, and additionally development of fish passages specialized for Korean fishes are required
ZNF746/PARIS overexpression induces cellular senescence through FoxO1/p21 axis activation in myoblasts
Various stresses, including oxidative stress, impair the proliferative capacity of muscle stem cells leading to declined muscle regeneration related to aging or muscle diseases. ZNF746 (PARIS) is originally identified as a substrate of E3 ligase Parkin and its accumulation is associated with Parkinson’s disease. In this study, we investigated the role of PARIS in myoblast function. PARIS is expressed in myoblasts and decreased during differentiation. PARIS overexpression decreased both proliferation and differentiation of myoblasts without inducing cell death, whereas PARIS depletion enhanced myoblast differentiation. Interestingly, high levels of PARIS in myoblasts or fibroblasts induced cellular senescence with alterations in gene expression associated with p53 signaling, inflammation, and response to oxidative stress. PARIS overexpression in myoblasts starkly enhanced oxidative stress and the treatment of an antioxidant Trolox attenuated the impaired proliferation caused by PARIS overexpression. FoxO1 and p53 proteins are elevated in PARIS-overexpressing cells leading to p21 induction and the depletion of FoxO1 or p53 reduced p21 levels induced by PARIS overexpression. Furthermore, both PARIS and FoxO1 were recruited to p21 promoter region and Trolox treatment attenuated FoxO1 recruitment. Taken together, PARIS upregulation causes oxidative stress-related FoxO1 and p53 activation leading to p21 induction and cellular senescence of myoblasts. © 2020, The Author(s).1
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