• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.229-237
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• 2021

Cloud of things (CoTs) is a newer idea which combines cloud computing (CC) with the Internet of Things (IoT). IoT capable of comprehensively producing data, and cloud computing can be presented pathways that allow for the progression towards specific destinations. Integrating these technologies leads to the formation of a separate element referred to as the Cloud of Things (CoTs). It helps implement ideas that make businesses more efficient. This technology is useful for monitoring a device or a machine and managing or connecting them. Since there are a substantial amount of machines that can run the IoT, there is now more data available from the IoT that would have to be stored on a local basis for a provisional period, and this is impossible. CoTs is used to help manage and analyze data to additionally create usable information by permitting and applying the development of advanced technology. However, combining these elements has a few drawbacks in terms of how secure the process is. This investigation aims to recent study literature from the past 3 years that talk about how secure the technology is in terms of protecting by authentication, reliability, availability, confidentiality, and access control. Additionally, this investigation includes a discussion regarding some kinds of potential attacks when using Cloud of Things. It will also cover what the various authors recommend and conclude with as well as how the situation can be approached to prevent an attack.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.271-276
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• 2020

In this study, an amorphous SiC block was manufactured using polycarbosilane (PCS), an organosilicon polymer. The dense SiC blocks were easily fabricated in various shapes via pyrolysis at 1100℃, 1200℃, 1300℃, 1400℃ after manufacturing a PCS molded body using cured PCS powder. Physical and chemical properties were analyzed using a thermogravimetric analyzer (TGA), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and universal testing machine (UTM). The prepared SiC block was decomposed into SiO and CO gas as the temperature increased, and β-SiC crystal grains were grown in an amorphous structure. In addition, the density and flexural strength were the highest at 1.9038 g/㎤ and 6.189 MPa of SiC prepared at 1100℃. The manufactured amorphous silicon carbide block is expected to be applicable to other fields, such as the previously reported microwave assisted heating element.

• Journal of IKEEE
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• v.25 no.1
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• pp.95-100
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• 2021

If we know the location of the hull block and the welding feeder in the shipyard, we can easily obtain the location information of the worker. That data is very useful for implementing a workplace safety monitoring system. However, it is difficult to apply a fixed communication network to the workplace due to the specificity of the hull structure and welding process. In this study, inductive power line communication, which can replace dedicated communication line, was reviewed. A ferrite core was used as an inductive coupler to be installed on the power cable of the welding machine, and a nano-crystalline core was applied as a coupler to be fastened to the support rod of the metal block. In order to visualize the operating principle of the proposed couplers, 3D modeling and finite element analysis were performed with the COMSOL AC/DC module. In the communication performance test using an aluminum profile, when the communication channel was formed by the contact of the welding electrode, the bandwidth was kept above 6 Mbps.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.508-524
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• 2021

Innovative translation circumstances encouraged by scientific technique have become an element that increases realization and possibility of expanding sign language translation and Korean sign language translation is facing a new challenge and opportunity. This study raises following questions and search for answers. First, when and how did Korean sign language translation appear in the course of the historical changes in Korean sign language? Second, what is the form and characteristic of translation produced as a result of Korean sign language translation? Third, what is the present condition and prospect of Korean sign language translation? Accordingly, this study examined how Korean sign language translation was formed historically and the form and characteristics of Korean sign language translation using integrated literature review method. As a result of the study, first, the form and characteristics of Korean sign language translation classified according to the historical transition process into latent phase, formation phase, and expansion phase were revealed. Second, the forms and characteristics of Korean sign language translation according to the Korean sign language corpus project and machine translation were derived. In addition, it apprehends its present condition and proposes its future prospect.

• Composites Research
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• v.34 no.6
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• pp.394-399
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• 2021

Piecewise Integrated Composite (PIC) is a new concept to design composite structures of multiple stacking angles both for in-plane direction and through the thickness direction in order to improve stiffness and strength. In the present study, PIC beam was suggested based on 3D training data instead of 2D data, which did offer a limited behavior of beam characteristics, with enhancing the stiffness accompanied by reduced tip deformation. Generally training data were observed from the designated reference finite elements, and preliminary FE analysis was conducted with respect to regularly distributed reference elements. Also triaxiality values for each element were obtained in order to categorize the loading state, i.e. tensile, compressive or shear. The main FE analysis was conducted to predict the mechanical characteristics of the PIC beam.

• Smart Structures and Systems
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• v.30 no.3
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• pp.333-338
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• 2022

Planning activity is complex process assuming the term "complexity" as a group of elements interconnected each other. The common knowledge about city planning underlines its main aim as: figuring the present, imaging the future, governing every day the territory and the way people use and live it at different scales. When considering the strength of technological opportunities and the spreading of ICT and IoT devices within everyday life, that mean within the life of cities, the complex nature of the urban system increases with the intensification of information and their connections. Recent orientations about urban and regional planning try to carry the discipline to a more flexible approach in respect to the hyperdeterminant role of direct technical applications. This passage is a fundamental aspect considering the faster and faster modifications of social and economic assets at the global and local scale. At the same time, the "environment question" became more and more relevant at the worldwide scale within the 2015 UN 2030 Agenda for Sustainable Development. Another relevant aspect about the recent urban planning orientations regards the role of the different subjects that are part of the planning process. Approaching the government of smart cities means to define how every subject, with different roles (public or private), could enrich the knowledge of the functioning of the "urban machine" and the awareness of participation of people and city users in the quality of urban life. In the paper author starts defining recent approaches in urban planning, then the nature of the city as a complex system is analyzed from the point of view of planners and of the different subjects that act in the city. Then the smart city is introduced as a further level of complexity and finally author propose the basic element of a Planning Support System.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.558-567
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• 2022

The evolution of temperature and thermal stress in a granite specimen is studied via heating experiment in the context of a high-level radioactive waste repository. A heating condition based on the decay-induced heat is applied to a cubic granite specimen to measure the temperature and stress distributions and their evolution over time. The temperature increases quickly due to heat conduction along the heated surfaces, but a significant amount of thermal energy is also lost through other surfaces due to air convection and conduction into the loading machine. A three-dimensional finite element-based model is used to numerically reproduce the experiment, and the thermo-mechanical coupling behavior and modeling conditions are validated with the comparison to the experimental results. The most crucial factors influencing the heating experiment are analyzed and summarized in this paper for future works.

• Geomechanics and Engineering
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• v.28 no.6
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• pp.599-611
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• 2022

Tendon reinforced cemented soil is applied extensively in foundation stabilisation and improvement, especially in areas with soft clay. To solve the deterioration problem led by steel corrosion, the glass fiber-reinforced polymer (GFRP) tendon is introduced to substitute the traditional steel tendon. The interface bond strength between the cemented soil matrix and GFRP tendon demonstrates the outstanding mechanical property of this composite. However, the lack of research between the influence factors and bond strength hinders the application. To evaluate these factors, back propagation neural network (BPNN) is applied to predict the relationship between them and bond strength. Since adjusting BPNN parameters is time-consuming and laborious, the particle swarm optimisation (PSO) algorithm is proposed. This study evaluated the influence of water content, cement content, curing time, and slip distance on the bond performance of GFRP tendon-reinforced cemented soils (GTRCS). The results showed that the ultimate and residual bond strengths were both in positive proportion to cement content and negative to water content. The sample cured for 28 days with 30% water content and 50% cement content had the largest ultimate strength (3879.40 kPa). The PSO-BPNN model was tuned with 3 neurons in the input layer, 10 in the hidden layer, and 1 in the output layer. It showed outstanding performance on a large database comprising 405 testing results. Its higher correlation coefficient (0.908) and lower root-mean-square error (239.11 kPa) were obtained compared to multiple linear regression (MLR) and logistic regression (LR). In addition, a sensitivity analysis was applied to acquire the ranking of the input variables. The results illustrated that the cement content performed the strongest influence on bond strength, followed by the water content and slip displacement.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.765-773
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• 2022

This study is a study on the application of a horizontal excavation machine system to improve constructability. In this study, the structural stability of non-covered temporary facilities was evaluated by comparing field measurements and numerical analysis. In addition, the appropriateness of the measurement results was analyzed by comparing and analyzing the results of numerical analysis with the analysis results applying the Gaussian probability density function to the measurement results. In this study, structural safety and long-term durability of the linkage were analyzed based on numerical analysis. As a result of the study, it was analyzed that the non-open cut method (H.A.S. method) of this study secures structural safety and constructability as the behavior in the actual construction process is more safe than the numerical analysis results, even if the uncertainty of the ground condition is taken into account.

• Progress in Medical Physics
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• v.33 no.1
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• pp.1-9
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• 2022

Purpose: To evaluate the effective volume of the Korea Research Institute of Standards and Science free air chamber (KRISS FAC) L1 used for the primary standard device of the low-energy X-ray air kerma. Methods: The mechanical dimensions were measured using a 3-dimensional coordinate measuring machine (3-d CMM, Model UMM 500, Carl Zeiss). The diameter of the diaphragm was measured by a ring gauge calibrator (Model KRISS-DM1, KRISS). The elongation of the collector length due to electric field distortion was determined from the capacitance measurement of the KRISS FAC considering the result of the finite element method (FEM) analysis using the code QuickField v6.4. Results: The measured length of the collector was 15.8003±0.0014 mm with a 68% confidence level (k=1). The aperture diameter of the diaphragm was 10.0021±0.0002 mm (k=1). The mechanical measurement volume of the KRISS FAC L1 was 1.2415±0.0006 cm³ (k=1). The elongated length of the collector due to the electric field distortion was 0.170±0.021 mm. Considering the elongated length, the effective measurement volume of the KRISS FAC L1 was 1.2548±0.0019 cm³(k=1). Conclusions: The effective volume of the KRISS FAC L1 was determined from the mechanically measured value by adding the elongated volume due to the electric field distortion in the FAC. The effective volume will replace the existing mechanically determined volume in establishing and maintaining the primary standard of the low-energy X-ray.