• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.4-5
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• 2021

In irregular curtain walls, the nominal stress required for each member varies greatly depending on the shape, so it is inefficient to design members based on the maximum required stress. Then, built-up members are absolutely necessary, but built-up members manufactured by Manpower-welding cannot be constructed in an irregular curtain wall building because it' not precise. In order to address the problems, this paper presents why Robotic-laser-welding should be used in irregular curtain walls using Gwanggyo Galleria Department Store involving 3D printing as an example. Results verify the performance of Robot-Laser-Welding as an efficient solution for precise steel curtain wall members.

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.55-62
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• 2023

Slotted-Aloha (S-Aloha) has been widely employed in random access networks owing to its simple implementation in a distributed manner. To enhance the throughput performance of the S-Aloha, connection-based slotted-Aloha (CS-Aloha) has been proposed in recent years. The fundamental principle of the CS-Aloha is to establish a connection with a short-sized request packet before transmitting data packets. Subsequently, the connected node transmits long-sized data packets in a batch of size M. This approach efficiently reduces collisions, resulting in improved throughput compared to the S-Aloha, particularly for a large M. In this paper, we address the short-term fairness of the CS-Aloha, as quantified by Jain's fairness index. Specifically, we evaluate how equitably the CS-Aloha allocatestime slots to all nodes in the network within a finite time interval. Through simulation studies, we identify the impact of system parameters on the short-term fairness of the CS-Aloha and propose an optimal transmission probability to support short-term fairness.

• Informatization Policy
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• v.25 no.2
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• pp.20-45
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• 2018

This study aims to find the factors of Internet overdependence in adults, through the decision tree analysis model, which is a data mining method using National Information Society Agency's raw data from the survey on Internet overdependence in 2016. As a result of the decision tree analysis, a total 16 nodes of Internet overdependence risk groups were identified. The main predicated variables were the amount of time spent per smart media usage in weekdays; amount of time spent per smart media usage in weekends; experiences of purchasing cash items; percentage of using smart media for leisure; negative personality; percentage of using smart media for information search and utilization; and awareness on good functions of the Internet, all of which in order had greater impact on the risk groups. Users in the highest risk node spent the smart media for more than 5 minutes per use and less than 5~10 minutes in weekdays, had experiences of cash item purchase, and had lower level of awareness on the good functions of the Internet. The analysis led to the following recommendations: First, even a short-time use has higher chances of causing Internet overdependence, and therefore, guidelines need to be developed based on research on the usage behavior rather than the usage time. Second, self-regulation is required because factors that affect overindulgence in games, such as the cash items, increase Internet overdependence. Third, using the Internet for leisure causes higher risk of overdependence and therefore, other means of leisure should be recommended.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.31-40
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• 2021

Blockchain technology is also actively studied in the real estate transaction field, and real estate transactions have various ways. In this paper, we propose a model that simplifies the authentication procedure of auction systems using Ethereum's Ether to solve the problem of offline court auctions. The proposed model is written in Ethereum's Solidity language, the court registers the sale date and the sale date with the DApp browser, and the bidder accesses the address of the individual's wallet created through Metamask's private key. The bidder then selects the desired sale and enters the bid price amount to participate in the auction. The bidder's record of the highest bid price for the sale he wants is written on the Ethereum test network as a smart contract. and creates a block. Finally, smart contracts written on the network are distributed by the court auction manager to all nodes in the blockchain network, and each node in the blockchain network can be viewed and contract verified. As a result of analyzing the smart contracts of the proposed model and the performance of the system, there are fees incurred due to the creation and use of Ether on platforms using Ethereum, and participation. Ether's changes in value affect the price of the sale, resulting in inconsistent fees in smart contracts each time. However, in future work, we issue our own tokens to solve the market volatility problem and commission problem with the value change of Ether, and refine complex court auction systems.

• Journal of Life Science
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• v.26 no.9
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• pp.1027-1032
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• 2016

Antigen is substance causing disease derived from pathogen. Living organism has the immune system in terms of defense mechanism against antigen. Antigen is processed through several pathways such as phagocytosis, antibody action, complement activation, and cytotoxins by NK or cytotoxic T lymphocyte via MHC molecule. Lymph node (LN) is comprised of the complicated 3 dimensional network and several stromal cells. Fibroblastic reticular cells (FRC) are distributed in T zone for interaction with T cells. FRC produces the extra cellular matrix (ECM) into LN for ECM reorganization against pathogen infections and secretes homing chemokines. However, it has not so much been known about the involvement of the antigen process of FRC. The present report is for the function of FRC on antigen process. For this, FRC was positioned with several infected situations such as co-culture with macrophage, T cell, lipopolysaccharide (LPS) and TNFα stimulation. When co-culture between FRC with macrophage and T cells was performed, morphological change of FRC was observed and empty space between FRCs was made by morphological change. The matrix metallo-proteinase (MMP) activity was up-regulated by Y27632 and T cells onto FRC. Furthermore, inflammatory cytokine, TNFα regulated the expression of adhesion molecules and MHC I antigen transporter in FRC by gene chip assay. NO production was elevated by FRC monolayer co-cultured with macrophage stimulated by LPS. GFP antigen was up-taken by macrophage co-cultured with FRC. Collectively, it suggests that FRC assists of the facilitation of antigen process and LN stroma is implicated into antigen process pathway.

• Smart Media Journal
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• v.12 no.1
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• pp.9-16
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• 2023

Recently, a convolutional neural network (CNN) based system is being developed to overcome the limitations of human resources in the apple quality classification of farmhouse. However, since convolutional neural networks receive only images of the same size, preprocessing such as sampling may be required, and in the case of oversampling, information loss of the original image such as image quality degradation and blurring occurs. In this paper, in order to minimize the above problem, to generate a image patch based graph of an original image and propose a random walk-based positional encoding method to apply the graph transformer model. The above method continuously learns the position embedding information of patches which don't have a positional information based on the random walk algorithm, and finds the optimal graph structure by aggregating useful node information through the self-attention technique of graph transformer model. Therefore, it is robust and shows good performance even in a new graph structure of random node order and an arbitrary graph structure according to the location of an object in an image. As a result, when experimented with 5 apple quality datasets, the learning accuracy was higher than other GNN models by a minimum of 1.3% to a maximum of 4.7%, and the number of parameters was 3.59M, which was about 15% less than the 23.52M of the ResNet18 model. Therefore, it shows fast reasoning speed according to the reduction of the amount of computation and proves the effect.

• The KIPS Transactions:PartD
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• v.19D no.3
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• pp.229-236
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• 2012

The demand for map applications in both Web and mobile environments has been rapidly increased with the population of Web and smart phone usage. Web-based map applications are mostly developed on such environments as ArcGIS and MapServer and mobile map applications are developed on such API levels as Google Maps and Yahoo Maps. But many parts of map applications are still constructed by coding because these environments don't support high level of automation. Our MapAppGen that we have designed and implemented enhances the Web-based map application productivity by generating the map related modules that can be applied to the Drupal that is one of popular content management systems(CMS's). Comparing the applications that are constructed by the Drupal-supported GMap or NodeMap, the applications that are constructed by MapAppGen provide information on not only the interested geographical feature but also its related geographical features. MapAppGen uses Google Maps API and Drupal is a module-based system that supports the creation, composition and management of contents. We are now working on automatic generation of mobile map applications with MapAppGen.

• Smart Structures and Systems
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• v.18 no.6
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• pp.1189-1202
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• 2016

This paper describes an application of wavelet analysis for damage detection of a steel frame structure with bolted connections. The wavelet coefficients of the acceleration response for the healthy and loosened connection structure were calculated at each measurement point. The difference of the wavelet coefficients of the response of the healthy and loosened connection structure is selected as an indicator of the damage. At each node of structure the norm of the difference of the wavelet coefficients matrix is then calculated. The point for which the norm has the higher value is a candidate for location of the damage. The above procedure was experimentally verified on a laboratory-scale 2-meter-long steel frame. The structure consists of 11 steel beams forming a four-bay frame, which is subjected to impact loads using a modal hammer. The accelerations are measured at 20 different locations on the frame, including joints and beam elements. Two states of the structure are considered: healthy and damaged one. The damage is introduced by means of loosening two out of three bolts at one of the frame connections. Calculating the norm of the difference of the wavelet coefficients matrix at each node the higher value was found to be at the same location where the bolts were loosened. The presented experiment showed the effectiveness of the wavelet approach to damage detection of frame structures assembled using bolted connections.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1089-1096
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• 2019

Recently, small-scale IoT services using a small amount of information through low-performance computing have been spread. It requires low cost, low-power, and long-distance communication technologies with wide communication radius, relatively low power consumption. This paper proposes a MAC layer and routing protocol that supports multi-hop transmission in small-scale IoT environment distributed over a large area based on LoRa communication and delivering a small amount of sensing data. The terminal node is mobile and the communication type provides bidirectional transmission between the terminal node and the network application server. By applying the proposed protocol, a production line monitoring system for smart factory was implemented. It was confirmed that the basic monitoring functions are normally performed.

• Journal of Korean Society of Rural Planning
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• v.22 no.3
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• pp.21-31
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• 2016

This is a comparative study focused on the scenic landscape preferences derived from visitors's perceptions at the Dulle-gil and the uphill trail in Bukhansan National Park. Unlike previous landscape assessment methods, this study contains more direct and on-site analysis with methods of understanding the visitors' perceptions by using 'visitor employed photography(VEP)' which requires each visitor to take preferable scenic landscape with one's own smart phone camera. The scenic landscape types at two different trails were categorized and then the types favoring most of participants were verified. There are total number of 16 visual landscape types preferred by participants at both the Dulle-gil and the uphill trail in Bukhansan National Park. As in terms of consensus photography(CP) on the Dulle-gil was found to have more diverse elements including both natural and artificial elements compare to the uphill trail. Furthermore, the perceptually excited node(PEN) at the Dulle-gill were found to be more scattered evenly whereas PEN at the uphill trail were concentrated on the entrance and the top of the mountain. It is necessary to consider that the scenic landscape management at the Dulle-gil and the uphill trail require different approaches. Facilities were set based on careful consideration of distinctive geographical features and vegetation in the Dulle-gil. And the management need to be focus on the 'forested area' maintaining natural state in the uphill trail. Futhermore, the result of the CP and PEN in the trails would be helpful to proceed the next step of landscape perception study depending on characteristics of groups.