• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.1-7
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• 2019

Recently, multimedia streaming service has been activated, and the demand for high-quality multimedia convergence contents services is predicted to increase significantly in the future. The issues of the increasing network load due to the rise of multimedia streaming traffic must be addressed in order to provide QoS guaranteed services. To do this, an efficient network resource management and mobility support technologies are needed through seamless mobility support for heterogeneous networks. Therefore, in this paper, an MIH technology was used to recognize the network situation information in advance and reduce packet loss due to handover delays, and an ACLMIH-FHPMIPv6 is designed that can provide an intelligent interface through introducing a hierarchical mobility management technique in FPMIPv6 integrated network.

• Earthquakes and Structures
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• v.20 no.2
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• pp.215-224
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• 2021

The carbon dioxide present in the atmosphere is one of the main reasons for the corrosion of bridges, buildings, tunnels, and other reinforced concrete (RC) structures in most industrialized countries. With the growing use of fossil fuels in the world since the Industrial Revolution, the amount of carbon dioxide in urban and industrial areas of the world has grown significantly, which increases the chance of corrosion caused by carbonation. The process of corrosion leads to a change in mechanical properties of rebars and concrete, and consequently, detrimentally impacting load-bearing capacity and seismic behavior of RC structures. Neglecting this phenomenon can trigger misleading results in the form of underestimating the seismic performance metrics. Therefore, studying the carbonation corrosion influence on the seismic behavior of RC structures in urban and industrial areas is of great significance. In this study, a 2D modern RC moment frame is developed to study and assess the effect of carbonation corrosion, in 5-year intervals, for a 50 years lifetime under two different environmental conditions. This is achieved using the nonlinear static and incremental dynamic analysis (IDA) to evaluate the reinforcement corrosion effects. The reduction in the seismic capacity and performance of the reinforced concrete frame, as well as the collapse probability over the lifetime for different corrosion scenarios, is examined through the capacity curves obtained from nonlinear static analysis and the fragility curves obtained from IDA.

• Journal of Platform Technology
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• v.8 no.4
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• pp.59-69
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• 2020

Recently, the seriousness of ultrafine dust and fine dust has emerged as a national disaster, but small and medium-sized cities in provincial areas lack fine dust monitoring stations compared to their area, making it difficult to manage fine dust. Although the computing resources for collecting and processing fine dust data are not large, it is necessary to utilize cloud and private and public data to share data. In this paper, we proposed a small edge computing system that can measure fine dust, ultrafine dust and temperature and humidity and process it to provide real-time control of fine dust and service to the public. Collecting fine dust data and using public and private data to service fine dust ratings is efficient to handle with edge computing using raspberry pie because the amount of data is not large and the processing load is not large. For the experiment, the experiment system was constructed using three sensors, raspberry pie and Thinkspeak, and the fine dust measurement was conducted in northern part of kyongbuk region. The results of the experiment confirmed the measured fine dust measurement results over time based on the GIS data of the private sector.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.2
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• pp.51-56
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• 2021

The brachial systolic blood pressure and pulse pressure are the predictors of cardiovascular disease in individuals over 50 years of age. As the stiffness increases, the reflex amplitude and pressure in the late systole increase, resulting in an increase in left ventricular load and myocardial oxygen demand. Therefore, it is necessary to study how stiffness affects blood pressure. In this study, the blood pressure pulse waves were measured before and after taking the drug, and the blood pressure pulse wave was measured before and after myocardial heart transplantation in patients with heart failure. The correlation between R, L, and C components of the Windkessel model was estimated by increasing blood pressure. As a result of modeling the parameters of the Windkessel model using the curve fitting method, the increase in blood pressure and decrease in systolic rise time were due to the increase in the L component in the RLC Windkessel model. Among the various mechanical characteristics of blood vessels, the most important parameter affecting high BP waveform is the inertance.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.133-138
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• 2021

In this study, Niacinamide (NI) was loaded into solid lipid nanoparticles (SLNs) and skin permeability was evaluated to improve skin permeability of NI, which was a skin whitening substance. NI was able to effectively load within SLN with a double-melting emulsification method, producing stable particles with average particle sizes of 263.30 to 436.93 nm and a zeta potential of -34.77 to -57.60 mV. Artificial skin tissue (SkinEthic^TM RHE) derived from skin keratinocytes derived from human epidermal tissue was used for the skin permeation study of NI. Skin transmittance and deposition experiments of NI confirmed that all SLN formulations improved skin transmittance and deposition rates of NI, approximately 5.4 ~ 7.6 and 9.5 ~ 20.8 improvement over SLN applications. Therefore, SLN manufactured in this study have shown sufficient results to improve the skin permeability of the functional whitening substance, NI.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2852-2858
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• 2022

A proton therapy facility is under development at Huazhong University of Science and Technology (HUST). To meet the need for fast energy changes during treatments, a beamline control system (BCS) has been designed and implemented. The BCS coordinates and controls various beamline devices by adopting a distributed architecture divided into three layers: the client, server, and device layers. Among these, the design of the server layer is the key to realize fast energy changes. The server layer adopts the submodule programming paradigm and optimizes the data interface among modules, allowing the main workflow to be separated from the device workflow and data. Furthermore, this layer uses asynchronous, multithreaded, and thread-locking methods to improve the system's ability to operation efficiently and securely. Notably, to evaluate the changing energy status over time, a dynamic node update method is adopted, which can dynamically adjust the update frequency of variable nodes. This method not only meets the demand for fast updates on energy changes but also reduces the server's communication load in the steady state. This method is tested on a virtual platform, and the results are as expected.

• Safety and Health at Work
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• v.13 no.1
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• pp.9-16
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• 2022

Background: The global shift toward greener societies demands new technologies and work operations in the waste-management sector. However, progressive industrial methods do not necessarily consider workers' health. This study characterized workers' exposure to bioaerosols and investigated the bioaerosols' potential to engage the immune system in vitro. Methods: Full shift personal aerosol sampling was conducted over three consecutive days. Dust load was analyzed by gravimetry, fungal and actinobacterial spores were analyzed by scanning electron microscopy, and endotoxin by limulus amebocyte lysate (LAL) assay. In vitro exposure of HEK cells to airborne dust samples was used to investigate the potential of inducing an inflammatory reaction. Results: The total dust exposure level exceeded the recommended occupational exposure limit (OEL) of 5.0 mg/m³ in 3 out of 15 samples. The inhalable endotoxin level exceeded the recommended exposure level by a 7-fold, whereas the fungal spore level exceeded the recommended exposure level by an 11-fold. Actinobacterial spores were identified in 8 out of 14 samples. In vitro experiments revealed significant TLR2 activation in 9 out of 14 samples vs. significant TLR4 activation in all samples. Conclusion: The present study showed that the dust samples contained potentially health-impairing endotoxin, fungi, and actinobacterial levels. Furthermore, the sampled dust contained microbial components capable of inducing TLR activation and thus have the potential to evoke an inflammatory response in exposed individuals.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.2
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• pp.96-108
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• 2022

In this paper, we propose a systematic hull form variation technique which automatically satisfies the displacement constraint and guarantees a high level of fairness. This method is possible through multiple parameter correction curves. The present method is to improve the hull form variation method based on parametric modification function and consists of two sub-categories: SAC variation and section lines modification. For SAC variation, the utilization of two B-Spline curves satisfying GC¹ condition led to the satisfaction of displacement constraint and high level of fairness at the same time. Section lines modification methods involves in using two fuctions: the first is the waterplane modification function combining two cubic splines. the other function is the sectional area modification function consisting of 2nd order polynomial over the DLWL(Design Load Waterline) and 3rd order polynomial below the DLWL, This function enables not only the fundamental U-V section shape variation but also systematically modified section lines. The present method is expected to be more useful in the hull form optimization process using CFD compared to the existing method.

• Advances in concrete construction
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• v.12 no.5
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• pp.429-437
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• 2021

In the era of building engineering the intensification of Self Compacting Concrete (SCC) is world-shattering magnetism. It has lot of rewards over ordinary concrete i.e., enrichment in production, cutback in manpower, brilliant retort to load and vibration along with improved durability. In the present study, the mechanical strength of CM-2 (SCC containing 10% of rice husk ash (RHA) as cement replacement and 600 grams of glass fibers per cubic meter) was investigated at various dosages of cement replacement by fly ash (FA) and GGBS. A total of 17 SCC mixtures including two control SCC mixtures (CM-1 and CM-2) were developed for investigating fresh and hardened properties in which, ten ternary cementitious blends of SCC by blending OPC+RHA+FA, OPC+RHA+GGBS and five quaternary cementitious blends (OPC+RHA+FA+GGBS) at different replacement dosages of FA and GGBS were developed with reference to CM-2. For constant water-cement ratio (0.42) and dosage of SP (2.5%), the addition of glass fibers (600 grams/m³) in CM-1 i.e., CM-2 shows lower workability but higher mechanical strength. While fly ash based ternary blends (OPC+RHA+FA) show better workability but lower mechanical strength as FA content increases in comparison to GGBS based ternary blends (OPC+RHA+GGBS) on increasing GGBS content. The pattern for mixtures appeared to exhibit higher workablity as that of the concentration of FA+GGBS rises in quaternary blends (OPC+RHA+FA+GGBS). A decrease in compressive strength at 7-days was noticed with an increase in the percentage of FA and GGBS as cement replacement in ternary and quaternary blended mixtures with respect to CM-2. The highest 28-days compressive strength (41.92 MPa) was observed for mix QM-3 and the lowest (33.18 MPa) for mix QM-5.

• Wind and Structures
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• v.35 no.1
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• pp.55-66
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• 2022

Tall buildings are often subjected to steady and unsteady forces due to external wind flows. Measurement and mitigation of these forces becomes critical to structural design in engineering applications. Over the last few decades, many approaches such as modification of the external geometry of structures have been investigated to mitigate wind-induced load. One such proven geometric modification involved the rounding of sharp corners. In this work, we systematically analyze the impact of rounded corner radii on the reducing the flow-induced loading on a square cylinder. We perform 3-Dimensional (3D) simulations for high Reynolds number flows (Re=1 × 105) which are more likely to be encountered in practical applications. An Improved Delayed Detached Eddy Simulation (IDDES) method capable of capturing flow accurately at large Reynolds numbers is employed in this study. The IDDES formulation uses a k-ω Shear Stress Transport (SST) model for near-wall modelling that prevents mesh-induced separation of the boundary layer. The effects of these corner modifications are analyzed in terms of the resulting variations in the mean and fluctuating components of the aerodynamic forces compared to a square cylinder with no geometric changes. Plots of the angular distribution of the mean and fluctuating coefficient of pressure along the square cylinder's surface illustrate the effects of corner modifications on the different parts of the cylinder. The windward corner's separation angle was observed to decrease with an increase in radius, resulting in a narrower and longer recirculation region. Furthermore, with an increase in radius, a reduction in the fluctuating lift, mean drag, and fluctuating drag coefficients has been observed.