• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1845-1865
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• 2019

Current Internet is designed by lots of service providers with different objects and policies which make the direct deployment of radically new architecture and protocols on Internet nearly impossible without reaching a consensus among almost all of them. Network virtualization is proposed to fend off this ossification of Internet architecture and add diversity to the future Internet. As an important part of network virtualization, virtual network embedding (VNE) problem has received more and more attention. In order to solve the problems of large embedding cost, low acceptance ratio (AR) and environmental adaptability in VNE algorithms, cognitive method is introduced to improve the adaptability to the changing environment and a cognitive virtual network embedding algorithm based on weighted relative entropy (WRE-CVNE) is proposed in this paper. At first, the weighted relative entropy (WRE) method is proposed to select the suitable substrate nodes and paths in VNE. In WRE method, the ranking indicators and their weighting coefficients are selected to calculate the node importance and path importance. It is the basic of the WRE-CVNE. In virtual node embedding stage, the WRE method and breadth first search (BFS) algorithm are both used, and the node proximity is introduced into substrate node ranking to achieve the joint topology awareness. Finally, in virtual link embedding stage, the CPU resource balance degree, bandwidth resource balance degree and path hop counts are taken into account. The path importance is calculated based on the WRE method and the suitable substrate path is selected to reduce the resource fragmentation. Simulation results show that the proposed algorithm can significantly improve AR and the long-term average revenue to cost ratio (LTAR/CR) by adjusting the weighting coefficients in VNE stage according to the network environment. We also analyze the impact of weighting coefficient on the performance of the WRE-CVNE. In addition, the adaptability of the WRE-CVNE is researched in three different scenarios and the effectiveness and efficiency of the WRE-CVNE are demonstrated.

• Journal of muscle and joint health
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• v.26 no.2
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• pp.141-154
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• 2019

Purpose: This study aimed to analyze the effects of exercise on pulmonary function in patients with ankylosing spondylitis (AS). Methods: Randomized controlled trials (RCTs) were identified by searching MEDLINE, EMBASE, CENTRAL, and CINAHL (through Jan 2019). Three reviewers independently retrieved articles, extracted data, and assessed methodological quality using the Cochrane's Risk of Bias for randomized studies. Results: Fourteen studies met the inclusion criteria with a total of 729 participants. CE (SMD 0.58, 95% CI 0.41~0.75, p<.001) and $VO_2peak$ (SMD 0.56, 95% CI 0.24~0.88, p=.001) had a significant effect on the most exercise interventions. As a secondary variable, BASFI (SMD -0.53, 95% CI -0.70~-0.37, p<.001), BASMI (SMD -0.75, 95% CI -0.92~-0.58, p<.001) showed an effect size of more than medium. However, PFT and QoL did not produce a significant results. Conclusion: Pulmonary involvement is common in patients with AS and might have disturbed functionality and exercise modality. Exercise can be an effective intervention to improve pulmonary function in patients with AS. More attention is needed to improve the chest and spinal mobility to maintain the appropriate pulmonary function. It is also necessary to consider how to construct a patient-tailored exercise program to increase performance, accuracy and safety of exercise.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.25-31
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• 2019

360 video is attracting attention as immersive media, and is also considered in VVC (Versatile Video Coding), which is being developed in JVET (Joint Video Expert Team) as a new video coding standard of post-HEVC. A 2D image projected from 360 video for its compression may has discontinuities between the projected faces and inactive regions, and they may cause the visual artifacts in the reconstructed video as well as decrease of coding efficiency. In this paper, we propose a method of efficient geometric padding to reduce these discontinuities and inactive regions in the projection format of SSP (Segmented Sphere Projection). Experimental results show that the proposed method improves subjective quality compared to the existing padding of SSP that uses copy padding with minor loss of coding gain.

• Conservation Science in Museum
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• v.24
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• pp.75-80
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• 2020

X-ray computed tomography (X-ray CT), which is often applied to the investigation of the interior structures of cultural properties, is very useful for studying production methods used in lacquerware that would otherwise be difficult to observe with the naked eye. Lacquerware inlaid with mother-of-pearl is an important subject in the study of traditional Korean craft. However, it can be a challenge to specify the production methods used in the framework of a lacquerware item unless the object has been structurally damaged. Studies of lacquerware inlaid with mother-of-pearl have thus far focused on the techniques of lacquering and of inlaying the mother-of-pearl. Production methods for the framework of lacquerware has received little academic attention. This study conducted X-ray CT on a lacquerware item from the Joseon period to reveal the materials and woodworking techniques used for the framework. The study revealed that softwood was used for the framework, and the post (gidungmok) and apron (soemok) were joined using a three-way miter joint (sambang yeongwi jjaim). Other pieces were joined with nails.

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.125-135
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• 2022

UAM is emerging as the biggest issue in the aviation industry and which is attracting a lot of attention not only domestically but also internationally. In Korea, active research is being conducted centered on the government and industry-university research institutes, such as the establishment of a future K-UAM concept of operation. Therefore, in this study applies the SORA (Specific Operation Risk Assessment) model established by the European JARUS (Joint Authorities for Rulemaking on Unmanned Systems) to apply the K-UAM operation environment and specific corridor for the purpose of cargo transportation that will be operated in the future that the government is promoting. We intend to suggest policy and technical measures for risk mitigation in the initial operating environment by evaluating the level of risk and analyzing the results.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.476-487
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• 2022

International research cooperation is emerging as one of the strategies for improving research performance. Therefore, in this study, through the analysis of research reports on the theme of international research cooperation, the subject and issues of international research cooperation were identified and the characteristics of these studies were confirmed. To this end, related report data were constructed, statistical data analysis and big data analysis of the data were performed. Considering the current international research cooperation network, it is necessary to conduct international research cooperation centered on developing countries while paying attention to the increase in China's proportion of international research cooperation. Second, it is necessary to emphasize the importance of international research cooperation in various countries, including developing countries, in that the interdependence of research between countries increases and the citation index of actual joint research is higher. Third, it can be seen that the subject field in which international research cooperation can be activated may vary depending on the type of support project. Therefore, it suggests that in order for international research cooperation on more diverse topics to be carried out, projects supporting them must also be diversified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.147-149
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• 2022

This paper proposes a state machine design methodology in which an interactive robot that mimics discrete trial training (DTT protocol) can support social interaction training for children with autism. The robot applied to social interaction training uses the response to the provided training stimulus as a quantitative indicator by processing the data received from the sensors measuring the behavioral response of the child. In this process, the state machine is used as information that classifies the state of the acquired data and provides the subsequent stimulus for DTT protocol. Through the joint attentional training, it can be used as evidence-based treatment information by quantitatively classifying the data on the number of sustainable and DTT protocol and the child's response, as well as the current reaction status of the child to the observer performing remote monitoring. At the same time, it was confirmed that it is possible to properly respond to misrecognition situations.

• Smart Structures and Systems
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• v.32 no.1
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• pp.23-35
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• 2023

Steel bolted joint is an important part of steel structure, and its damage directly affects the bearing capacity and durability of steel structure. Currently, the existing research mainly focuses on the identification of corroded bolts and corroded bolts respectively, and there are few studies on multiple states. A detection framework of corroded and loosened bolts is proposed in this study, and the innovations can be summarized as follows: (i) Vision Transformer (ViT) is introduced to replace the third and fourth C3 module of you-only-look-once version 5s (YOLOv5s) algorithm, which increases the attention weights of feature channels and the feature extraction capability. (ii) Three states of the steel bolts are considered, including corroded bolt, bolt missing and clean bolt. (iii) Line segment detector (LSD) is introduced for bolt rotation angle calculation, which realizes bolt looseness detection. The improved YOLOv5s model was validated on the dataset, and the mean average precision (mAP) was increased from 0.902 to 0.952. In terms of a lab-scale joint, the performance of the LSD algorithm and the Hough transform was compared from different perspective angles. The error value of bolt loosening angle of the LSD algorithm is controlled within 1.09%, less than 8.91% of the Hough transform. Furthermore, the proposed framework was applied to fullscale joints of a steel bridge in China. Synthetic images of loosened bolts were successfully identified and the multiple states were well detected. Therefore, the proposed framework can be alternative of monitoring steel bolted joints for management department.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1A
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• pp.147-154
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• 2008

The purpose of this study is to critically evaluate the structural performance of an innovative new shear resistance connecting structure of precast member. Joints such as shear resistance connecting structure require special attention when designing and constructing precast segmental structures. An experimental and analytical study was conducted to quantify performance measures and examine one aspect of detailing for developed shear resistance connecting structure. A computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. A joint element is used to predict the inelastic behavior of the joints between segmental members. Future work by the authors will do a model test of precast segmental prestressed concrete bridge columns with this shear resistance connecting structure, and examined both the structural behavior and seismic performance.

• Korean Journal of Child Education & Care
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• v.17 no.1
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• pp.1-28
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• 2017

This is a case study on how infants' behaviors change after their child care teachers use Responsive Interactions to them. The participants are five infants and five child care teachers from five employer-supported child care centers run and managed by H foundation. This study analyzes the changes in infants' pivotal developmental behaviors based on interactions between an infant and a child care teacher in video recordings, anecdotal records, Reflective Journal written by the teachers, and data on in-depth interviews with the child care teachers. The results show that Responsive Interactions have brought positive changes to infants' pivotal developmental behaviors(Attention to Activity, Problem Solving Persistence, Involvement, Cooperation, Initiation, Joint Attention and Affect). It suggests that child care teachers who are in charge of taking care of infants should realize and practice the importance of Responsive Interaction Strategy in order to help the infants develop their pivotal behaviors.