• Structural Engineering and Mechanics
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• v.75 no.5
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• pp.559-569
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• 2020

In the present study, the fracture toughness of U-shaped notches made of aluminum alloy Al7075-T6 under combined tension/out-of-plane shear loading conditions (mixed mode I/III) is studied by theoretical and experimental methods. In the experimental part, U-notched test samples are loaded using a previously developed fixture under mixed mode I/III loading and their load-carrying capacity (LCC) is measured. Then, due to the presence of considerable plasticity in the notch vicinity at crack initiation instance, using the Equivalent Material Concept (EMC) and with the help of the point stress (PS) and mean stress (MS) brittle failure criteria, the LCC of the tested samples is predicted theoretically. The EMC equates a ductile material with a virtual brittle material in order to avoid performing elastic-plastic analysis. Because of the very good match between the EMC-PS and EMC-MS combined criteria with the experimental results, the use of the combination of the criteria with EMC is recommended for designing U-notched aluminum plates in engineering structures. Meanwhile, because of nearly the same accuracy of the two criteria and the simplicity of the PS criterion relations, the use of EMC-PS failure model in design of notched Al7075-T6 components is superior to the EMC-MS criterion.

• Journal of Korea Game Society
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• v.14 no.2
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• pp.77-84
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• 2014

Presence of soft shadow effects from an area light makes virtual scenes look more realistic. However, since computation of soft shadow effects takes a long time, acceleration methods are required to apply it to real-time 3D applications. Many researches assumed that area lights are white rectangles. We suggest a new method which renders soft shadows under the area light source having arbitrary shape and color. In order to approximate visibility test, we use a shadow mapping result near a pixel. Complexity of shadow near a pixel is used to determine degree of precision of our visibility estimation. Finally, our method can present more realistic soft shadows for the area light that have more general shape and color in real-time.

• Advances in nano research
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• v.7 no.6
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• pp.379-390
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• 2019

Putting emphasis on the effect of existence of porosity in the functionally graded materials (FGMs) on the dynamic responses of waves scattered in FG nanobeams resulted in implementation of a novel porosity-based homogenization method for FGMs and show its applicability in a wave propagation problem in the presence of axial pre-load for the first time. In the employed porosity-dependent method, the coupling between density and Young's moduli is included to consider for the effective moduli of the FG nanobeam by the means of a more reliable homogenization technique. The beam-type element will be modeled via the classical theory of beams, namely Euler-Bernoulli beam theory. Also, the dynamic form of the principle of virtual work will be extended for such nanobeams to derive the motion equations. Applying the nonlocal constitutive equations of Eringen on the obtained motion equations will be resulted in derivation of the nanobeam's governing equations. Depicted results reveal that the dispersion responses of FG nanobeams will be decreased as the porosity volume fraction is increased which must be noticed by the designers of advanced nanosize devices who are interested in employment of wave dispersion approach in continuous systems for specific goals.

• Fashion & Textile Research Journal
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• v.21 no.4
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• pp.401-411
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• 2019

Non-contact judgment and evaluation for products are increasingly needed along with a rapid environmental change in fashion that sows urgency in the need to implement services that allows users to judge and experience a tactile sense in a fashion product without actual contact. Technological development is required to provide users with syn-aesthetic experiences that integrate the visual, tactile and the auditory. There is also a need to conduct research to increase immersion that provides users with ICT-related experiences communicated through fashion images. The study analyzed demands for haptic communication technology by Korean users in immersive VR fashion product shopping. Accordingly, it defined haptic communication through literature research, investigated immersion in the VR environment and conducted in-depth interviews for haptic communication applicable to VR shopping. Findings show that hedonic reactions by fantasy, emotion and fun function are an important motive in selecting VR shopping. VR fashion product shopping steps were divided into 4: move to store, search in store, search of product and purchase based on offline store shopping experience. It defined the haptic communication by steps and analyzed the types of the haptic feedback to be implemented. The study results provide basic data for developing haptic communication technology that can enhance e a sense of the presence and immersion experiences that can help lay a groundwork for pilot studies on the convergence of the virtual and the real.

• Journal of Drive and Control
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• v.19 no.3
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• pp.23-31
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• 2022

Traffic safety issues have recently been seriously magnified, due to child deaths in apartment complexes and parking lots. Accordingly, traffic safety technologies are being developed to recognize dangerous situations on living roads and to provide warning services. In this study, a collision detection algorithm was developed to prevent collision accidents between moving objects, by using object type and location information provided from CCTV monitoring devices. To determine the exact collision between moving objects, an object movement model was developed to predict the range of movement by considering the moving characteristics of the object, and a collision detection algorithm was developed to efficiently analyze the presence and location of the collision. The developed object movement model as well as the collision detection algorithm were simulated, in a virtual space of an actual living road to verify performance and derive supplementary matters.

• SUVANNABHUMI
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• v.15 no.2
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• pp.23-55
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• 2023

Just as globalization has many aspects and has developed in various, sometimes contradictory ways with both positive and negative impacts, so too would the reverse process of deglobalization have wide-ranging effects for individuals, communities, and nations. Some parts of globalization began to fray during the coronavirus pandemic (e.g. failing supply chains and disarray in the global shipping industry). Deglobalization would bring about much more significant changes in focusing on local production and consumption, eschewing non-essential flights and international tourism, and replacing personal experience with virtual presence. These impacts would be particularly severe for Vietnam, since its government has placed intensive connectivity with global production at the center of its model for the rapid development on which much of its legitimacy rests and it has joined as many international, multilateral organizations, and protocols as it has been able to do. Through critical analysis of secondary data from a wide range of sources, this paper examines the motivations that people, institutions, and governments might have to pursue deglobalization and then seeks evidence for whether the changes that would bring have started to affect Vietnam. While it is difficult to be too certain about this while the pandemic continues, it is evident that pressures are building in the global north to reconfigure supply chains for greater security, to reduce carbon emissions through regulating long-distance exchanges, and to withdraw from personal contacts. It is argued that a focus on digitalization in economy and society will help to mitigate the negative effects of deglobalization on Vietnam, at least in the medium-term.

• Asia pacific journal of information systems
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• v.30 no.1
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• pp.21-30
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• 2020

Bitcoin (BTC) is a type of cryptocurrency that supports transaction/payment of virtual money between BTC users without the presence of a central authority or any third party like bank. It uses some cryptographic techniques namely public- and private-keys, digital signature and cryptographic-hash functions, and they are used for making secure transactions and maintaining distributed public ledger called blockchain. In BTC system, each transaction signed by sender is broadcasted over the P2P (Peer-to-Peer) Bitcoin network and a set of such transactions collected over a period is hashed together with the previous block/other values to form a block known as candidate block, where the first block known as genesis-block was created independently. Before a candidate block to be the part of existing blockchain (chaining of blocks), a computation-intensive hard problem needs to be solved. A number of miners try to solve it and a winner earns some BTCs as inspiration. The miners have high computing and hardware resources, and they play key roles in BTC for blockchain formation. This paper mainly analyses the underlying cryptographic techniques, identifies some weaknesses and proposes their enhancements. For these, two modifications of BTC are suggested ― (i) All BTC users must use digital certificates for their authentication and (ii) Winning miner must give signature on the compressed data of a block for authentication of public blocks/blockchain.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.337-346
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• 2020

Traffic jam and congestion in urban areas has caused the need to improve the utility of underground space. In response, research on underground structures is increasingly being conducted. Notably, a double-deck tunnel is one of the most widely used of all those underground structures. This double-deck tunnel is separated by the middle slab into the upper and lower roadways. Both vehicle load and earthquake load cause the middle slab to exhibit dynamic behavior. Earthquake-related response characteristics, in particular, are highly complex and difficult to interpret in a theoretical context, and thus experimental research is required. The aim of the present study is to assess the stability of a double-deck tunnel's middle slab of the Collapse Prevention Level and Seismic Category 1 with regard to the presence of vibration-damping Rubber Bearings. In vibration table tests, the ratio of similitude was set to 1/4. Linings and vibrating platforms were fixed during scaled model tests to represent the integrated behavior of the ground and the applied models. In doing so, it was possible to minimize relative behavior. The standard TBM cross-section for the virtual double-deck tunnel was selected as a test subject. The level of ground motion exerted on the bedrock was set to 0.154 g (artificial seismic wave, Collapse Prevention Level and Seismic Category 1). A seismic wave with the maximum acceleration of 0.154 g was applied to the vibration table input (bedrock) to analyze resultant amplification in the models. As a result, the seismic stability of the middle slab was evaluated and analyzed with respect to the presence of vibration-damping rubber bearings. It was confirmed that the presence of vibration-damping rubber bearings improved its earthquake acceleration damping performance by up to 40%.

• Cartoon and Animation Studies
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• s.42
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• pp.177-194
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• 2016

This study investigated an evolutionary process of In-game Animation and researched on the action of realization establishing virtual reality. In-game Animation, functioning as contents to visualize games, is responsible for conveying information to achieve goals of games. In-game Animation which is affected by graphic technology was initiated with setting up indicators by dot and line. Followed by the development of technology, In-game Animation has pursued realization, after passing through processes of iconography, materialization, and dimensionalization. The realization of In-game Animation does not simply imitate the real world but creates meaning of reality by establishing space with various factors such as characters and background along with the story, under the premise of virtuality. The realization of In-game Animation is very important to provide the experience of immersion, as it forms a sense of presence through such visual tactility. The process to create meaning of reality provides gamers with experiences, and leads them to expand senses through visual perception and finally absorb the virtuality as reality. Therefore, the image of In-game Animation does not simply imitate the real world but creates meaning of reality by establishing space with various factors such as characters and background along with the story, under the premise of virtuality. The realization of In-game Animation is not limited to blindly portray a realistic image. In addition, the process of realization pursued by In-game Animation is an action to immerse in the game rather than a mere product of technological development.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.561-568
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• 2022

The purpose of this study is to explore the narrative of VR disaster and safety Education introduced by disaster film narrative. VR(Virtual Reality) is be suitable technology for disaster and safety Education due to media characteristics as 'immersion', 'presence', 'interactivity', 'pleasure'. Disaster film narrative is able to be worth VR disaster and safety education as a variety of stories and educational effect. For this study, examine a theoretical study and a visiting research of 'Busan 119 Safety & Experience Center'. This study concludes that Firstly need to introduce catharsis effect, Secondly, build 'interactive narratives' that ensure active participation of users, Thirdly, introduce an 'adventure game' narrative element, Fourthly, introduce a hero-shaped narrative in which the user becomes a one-man hero, And lastly, need education as use user's multiple access and group experience learning. Therefore, This thesis is of academic value in that it suggest a desirable new direction of narrative in VR disaster and safety education.