• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.3
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• pp.540-558
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• 2015

Maneuvering oblique towing test is simulated in a Computational Fluid Dynamic (CFD) environment to obtain the linear and nonlinear velocity dependent damping coefficients for a DTMB 5512 model ship. The simulations are carried out in freely accessible OpenFOAM library with three different solvers, rasInterFoam, LTSInterFoam and interDyMFoam, and two turbulence models, $k-{\varepsilon}$ and SST $k-{\omega}$ in presence of free surface. Turning and zig-zag maneuvers are simulated for the DTMB 5512 model ship using the calculated damping coefficients with CFD. The comparison of simulated results with the available experimental shows a very good agreement among them.

• The Plant Pathology Journal
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• v.35 no.3
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• pp.274-279
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• 2019

Artemisia sieberi showing symptoms resembling those caused by phytoplasma were observed in Geno Mountain, Hormozgan Province, Iran, and were examined for phytoplasma presence by PCR assays. In addition, the essential oils hydrodistilled from the aerial parts of phytoplasma-infected and healthy plants have been analyzed and compared by GC and GC/MS. Phylogenetic and virtual RFLP analysis of the 16S rRNA gene sequences revealed that the phytoplasma associated with A. sieberi witches' broom (AsWB) was a strain of 'Candidatus Phytoplasma aurantifolia'. The presence of the disease, however, induced a further enrichment (from 4.9 to 45.2%, a relative increase of 90%) of the entire monoterpene class as compared to the abundance in healthy samples. Conversely, a matching decrease in monoterpenoid (from 48.7 to 2%, a relative decrease of 90.2%) was observed in the infected plants. Besides the first report of phytoplasma infection of A. sieberi, the changes of its essential oils are reported.

• International Journal of Computer Science & Network Security
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• v.21 no.1
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• pp.64-69
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• 2021

In this paper, we have proposed a new internal model control structure (IMC). It is aimed at unstable overactuated multivariable systems whose transfer matrices are singular and unstable. The model inversion problem is essential to understand this structure. Indeed, the precision between the output of the process and the setpoint is linked to the quality of the inversion. This property is preserved in the presence of an additive disturbance at the output. This inversion approach proposed in this article can be applied to multivariable systems with no minimum phase or minimum phase shift with or without delays in their transfer matrices. It is proven by an example of simulation through which we have shown its good performance as a guarantee of stability, precision as well as rapidity of system responses despite the presence of external disturbances and we have tested this control structure in the frequency domain hence the robustness of the IMC.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.472-477
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• 2000

가상현실(VR； Virtual Reality)은 컴퓨터에 의해 인공적으로 만들어진 감각 몰입형(sense immersing) 환경 속에서 사용자가 이 환경과 상호작용(interaction) 할 수 있는 인간-컴퓨터 인터페이스(interface)라고 정의된다(Pimentel, 1995). 이 정의에 입각할 때 가상현실은 자율성 (Autonomy), 상호작용(Tnteraction), 임장감(Presence)이 라는 세 가지 기본 요소를 갖는데 이를 Zeltzer(1992)는 머릿글자를 취해 가상현실의 AIP 큐브(cube)로 표현한 바 있다.(중략)

• The Journal of Information Systems
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• v.14 no.1
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• pp.251-275
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• 2005

The advantages of implementing a virtual channel can be derived from the notion of the 'death of distance' that would result from electronic commerce. According to this view, the internet was going to make distance irrelevant, in that firms would no longer need to establish a physical presence in a geographical location in order to do business there. However, on-line firms selling physical products could take advantages of presence in the related off-line(brick and mortar) industrial area. This paper developed a conceptual framework that highlights the various types of synergies by location on-line businesses in the related off-line industrial area. Using data from 96 on-line ventures selling physical products, factor analysis was used to figuring out six synergies including improved customer trust, value-added service, cost savings, personnel and organizational efficiency, sharing products and customer information, relationship with suppliers, and relationship with local government. The six empirically derived critical synergy factors were then used to examine how they improve performance of the on-line ventures measured by Balanced Scorecard(BSC). According to lthe results, we concluded that the on-line firms selling physical products can take advantages of presence in the related off-line industrial area.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.93-101
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• 2022

Immersion is a features of VR technology, and the most important condition for evaluating VR experience. With the improvement of VR technology, including the presentation accuracy of VR content, the degree of interaction is diversified, the user's immersion in VR equipment should not only be improved technically, but researched from the user's perception level. The paper defines two important factors, immersion and presence, in a participant's experience with a VR device. Although the current technology can already simulate the real environment information visually and audibly, the content of the VR environment is not enough for us to achieve a completely real experience. Based on the Flow theory of Csikszentmihalyi and the sensory immersion achieved by current technology, this paper proposes the key factors of how to achieve conscious immersion for users in VR media. We prove that immersion is an indicator of the true degree of sensory simulation of VR equipment and is the basis for the realization of flow experience. What really makes the participant feel a perfect experience is the content provided by the VR environment and gave participants a sense of presence, it is not limited to video or games. On the premise of the Multi-Sensory, Immersion, Interactivity and Imagination experience achieved by using virtual reality technology, combined with the content creation of flow theory, the interactive immersion achieved by users is an important method to realize the awareness immersion of VR equipment.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.7
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• pp.646-656
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• 2008

In this paper, the prototype of haptic-based NVE (networked virtual environment) QoE (quality of experience) is proposed. The proposed framework plays a role of providing users with realistic feeling by managing the system and network resources efficiently under time-varying networks and heterogeneous systems. Therefore, first IoPH (importance of presence for haptic interaction) is defined to quantitate the sense of real that the users feel now. Then we define the haptic-based NVE components required to satisfy the haptic interaction QoE requirements. Finally, QoE adaptation scheme is suggested, which adapts the haptic-based NVE components to current network and system constraints for better haptic interaction quality.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.1-7
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• 2017

Virtual reality(VR) is known as immersive multimedia or computer-simulated reality, is a computer technology that replicates an environment, real or imagined, and simulates a user's physical presence and environment to allow for user interaction. Virtual realities artificially create sensory experience including sight, touch, hearing, and smell. Owing to the use of a single device in most VR contents, user have difficulty in manipulating user interface and game object. And also immersion of the game goes down because they can't see the mouse and keyboard in virtual space. In this paper, we design and implement the chess game to easily and accurately control user interface to improve the immersion in game.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.81-96
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• 2022

Covid-19 calls for minimizing gatherings of people in spaces such as offices. Organizations are encouraging information-sharing activities among employees by using online platform technology. Recently, Organizations are supporting their work using the metaverse. This study confirms the effect of metaverse presence on the intention to share knowledge by forming the intrinsic motivation of the employees and the moderating effect of the individual's digital technological competence. We presented research hypotheses through previous studies such as virtual reality and tested the hypotheses using 309 samples obtained through surveys. As a result, the social, tele, and self presence of the metaverse increased organizational-related intrinsic motivation(organizational identification, value congruence) and had a positive effect on the intention to share knowledge. In addition, digital technological competence moderated the relationship between value congruence and intention to share knowledge. This study suggests the importance of strategies to enhance the presence of metaverse for organizations to increase work productivity by using metaverse and the need to support individual digital competence reinforcement.

• The Journal of Information Technology
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• v.7 no.1
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• pp.69-86
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• 2004

In this paper, a conceptual framework describing the dynamics of click and mortar businesses is provided. It directs our attention to the many potential sources of synergy that are available to firms that choose to integrate e-commerce with their existing traditional forms of business. It further emphasizes the many actions that firms can take to minimize channel conflicts and help achieve the benefits of synergy. Finally, it describes four categories of synergy-related benefits from the integration of e-commerce with traditional businesses, including potential cost saving, gains due to enhanced differentiation, improved trust, and potential extensions into new markets. The utility of the framework was demonstrated using the case of an electronics retailer that has chosen to tightly integrate its large chain of retail stores with its Web-based electronic store. The framework was also used to develop a series of propositions that can guide future empirical research. The discussion points to the need to develop new types of metrics to better judge the contributions of e-commerce channels, and provides some guidance for future empirical research that can test whether, and under what conditions, integrated click and mortar business models work well. Thus, the purpose of this study is to present the combining physical and virtual presence in e-commerce.