• International conference on construction engineering and project management
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• 2020.12a
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• pp.137-145
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• 2020

Providing safety training to construction workers is essential to reduce safety accidents at the construction site. With the prosperity of visualization technologies, Immersive Virtual Reality (IVR) has been adopted for construction safety training by providing interactive learning experiences in a virtual environment. Previous research efforts on IVR-based training have found that the level of fidelity of interaction between real and virtual worlds is one of the important factors contributing to the sense of presence that would affect training performance. Various interactive devices that link activities between real and virtual worlds have been applied in IVR-based training, ranging from existing computer input devices (e.g., keyboard, mouse, joystick, etc.) to specially designed devices such as high-end VR simulators. However, the need for high-fidelity interactive devices may hinder the applicability of IVR-based training as they would be more expensive than IVR headsets. In this regard, this study aims to understand the impact of the level of fidelity of interactive devices in the sense of presence in a virtual environment and the training performance during IVR-based forklift safety training. We conducted a comparative study by recruiting sixty participants, splitting them into two groups, and then providing different interactive devices such as a keyboard for a low fidelity group and a steering wheel and pedals for a high-fidelity group. The results showed that there was no significant difference between the two groups in terms of the sense of presence and task performance. These results indicate that the use of low-fidelity interactive devices would be acceptable for IVR-based safety training as safety training focuses on delivering safety knowledge, and thus would be different from skill transferring training that may need more realistic interaction between real and virtual worlds.

• Journal of The Korean Association of Information Education
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• v.16 no.4
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• pp.397-407
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• 2012

According to the fast supply of the SMART device, many people have a lot of interests about SMART education. The Korean government is showing a lot of effort towards the promotion of SMART education. In this study, I developed a behavioral assessments and QR code based mobile web application for school education. The developed system works seamlessly across all popular mobile device platforms and if you save the data after the assessment, this system will automatically create each person's mobile web page. Students and teachers can add comments to this page and can improve the accessibility for finding the address of this page to QR code. The developed system can contribute to the class members understanding the personality of each other and make communication run smoothly. As a result of application of developed system, it is expected to contribute to increasing the interaction between a students, parents and teachers because the developed system provides a service based to education consumer's TPO(Time, Place, Occasion).

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.579-583
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• 2008

Web pages with complex layout and small font size do not display well on large screen display such as TV because it has limited capabilities: long distance view, passive user attitude, limited input device like a legacy remote controller. We have designed and implemented new semantic zoom browsing facilities to support effective navigation on Internet-connected digital television with limited capabilities. Our browser performs partitioning of an HTML document content into semantic blocks. Semantic blocks present summarized information with more readable style and modified layout for optimal reading and browsing. Individual blocks can be selected by the user and zoomed in more detail information by the user. The scrolling on large display device needs more user interaction. Our browser modifies the layout of an HTML document with removing horizontal scrolling and minimizing vertical scrolling. This method allows users to easily view the web page by converting into optimal reading style and layout and to easily seek the information just with zooming.

• Journal of Korea Multimedia Society
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• v.20 no.3
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• pp.511-519
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• 2017

This Paper introduces the design and communication method between PLC (Programmable Logic Controller) and Arduino based on MODBUS Protocol. MODBUS connection can be established in a new or existing system very easily, therefore we used this protocol in our proposed system. In the field of automatic devices, multi-function serial port such as RS232, RS422, RS485, and so on creates a great convenience to the developer. This proposed system used RS485 as a key mediator for data exchanging on a connected network. We also believe that it will reduce the development cost in various automated industry because this system can be reused or can be implemented any such PLC installed machines. RS485 is used as a communication interface between PLC (as a slave) and Arduino (as a master), through which a reliable network is created for safe and fast communication. Furthermore, RS485 allows multiple devices(up to 32) to communicate at half duplex on a single pair of wires and provides a long connectivity area (up to 1200 meters) as compare to other device, which makes it a user-friendly for various devices in the automated industry. Moreover, Arduino can play as a mediator by connecting third party device and setup a communication network with PLC.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.1-9
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• 2010

This paper introduces a difference between mobile Augmented Reality (AR) authoring and desktop AR authoring, and suggests an interface system that can be applied to in-situ authoring of AR contents on a mobile device. The mobile devices have enabled users to use the AR system anytime and anywhere. It is now necessary to create user's individualized context information using mobile devices on the spot. To author AR contents easily with mobile devices, we need to maximize the convenience of mobile systems, which have yet limitation. To do so, this paper suggests new interaction approaches that manage augmented contents using visual cues and other simple attribute settings. In addition, to solve the problem that users have to hold their mobile devices to track markers while authoring contents, this system enables users to author contents in environment based on captured images. This interface system also can make cooperation environment for more than one users to author contents. This paper verifies the usefulness of the proposed interface by user tests. The results of an analyzing users' comments show that the proposed interface is suitable for in-situ mobile authoring system.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.191-195
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• 2011

The measurement and prediction of bacterial transport of bacteria in aquatic systems is of fundamental importance to a variety of fields such as groundwater bioremediation ascending urinary tract infection. The motility of pathogenic bacteria is, however, often missing when considering pathogen translocation prediction. Previously, it was reported that flagellated E. coli can translate upstream under low shear flow conditions. The upstream swimming of flagellated microorganisms depends on hydrodynamic interaction between cell body and surrounding fluid flow. In this study, we used a breathable microfluidic device to image swimming E. coli at a glass surface under low shear flow condition. The tendency of upstream swimming motion was expressed in terms of 'A' value in parabolic equation ($y=Ax^2+Bx+C$). It was observed that high shear flow rate increased the 'A' value as the shear force acting on bacterium increased. Shorter bacterium turned more tightly into the flow as they swim faster and experience less drag force. The result obtained in this study might be relevant in studying the fate and transport of bacterium under low shear flow environment such as irrigation pipe, water distribution system, and urethral catheter.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.7
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• pp.647-654
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• 2010

In this study, an efficient ornithopter aerodynamic model, which is applicable to ornithopter wing design considering fluid-structure interaction or ornithopter flight dynamics and control simulation, was proposed and experimentally validated through the wind tunnel experiments. Due to the ornithopter aerodynamics governed by unsteady low Reynolds number flow, an experimental device was specially designed and developed. A part of the experimental device, 2-axis loadcell, was situated in the non-inertial frame; the dynamic calibration method was established to compensate the inertial load for pure aerodynamic load measurements. The characteristics of proposed aerodynamic model were compared with the experimental data in terms of mean and root-mean-square values of lift and drag coefficients with respect to the flow speed, flapping frequency, and fixed angle of attack.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.2
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• pp.62-67
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• 2002

This paper - following 'Development of multi-purpose marine waste cleaning systems for the shallow waters (Part I : preliminary conceptual design)'- describes on the system development and the sea trial performance evaluation(Cho[2003]). The multi-functional seabed waste collecting system and the towing hook system were developed. The maximum working depth of these systems are 15 and 100 meters, respectively(MOMAF[2001]). For the multi-purpose use to collect the marine waste, this system contains floating waste collecting device for the waste on seawater and remained waste collecting device for the waste on seabed, while steel wire cutting system is added for higher efficiency In order to evaluate the system performance, the prototype of multi-functional system was constructed and the sea trial test at shallow water were carried out. As a result, this system operated well with safe and without any interaction so that the developed systems are practicable and applicable.

• Nutrition Research and Practice
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• v.12 no.4
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• pp.291-297
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• 2018

BACKGROUND/OBJECTIVES: This study evaluated the effects and molecular mechanisms of the Schisandra chinensis fruit extract (SC) and its major compound gomisin A (GA), on the contractility of rabbit penile corpus cavernosum smooth muscle (PCCSM). MATERIALS/METHODS: PCCSM was exposed to SC or GA after appropriate pretreatment with nitric oxide synthase (NOS) blocker, guanylate cyclase blocker, adenylyl cyclase blocker or protein kinase A blocker. Subsequently, we evaluated the cyclic nucleotide in the perfusate by radioimmunoassay, protein expression level of neuronal NOS (nNOS) and endothelial NOS (eNOS) by western blot, and the interaction of SC or GA with udenafil and rolipram. RESULTS: Both SC and GA induce PCCSM relaxations in a concentration-dependent manner. Pretreatment with NOS blocker, guanylate cyclase blocker, adenylyl cyclase blocker or protein kinase A blocker result in significantly decreased relaxation. SC and GA also induce the levels of cyclic nucleotide in the perfusate in a concentration-dependent manner. Perfusion with GA also showed significantly higher levels of eNOS protein. Furthermore, the udenafil and rolipram induced relaxations of PCCSM were enhanced after exposure to SC and GA. Our results indicate that SC and GA induce the relaxation of PCCSM via the nitric oxide (NO)-cGMP and cAMP signaling pathways. CONCLUSIONS: The SC and GA are potential alternative treatments for men who want to consume natural products to ameliorate erectile function, or who do not respond to the commercially available medicines.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.674-682
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• 2018

In the time of the Fourth Industrial Revolution, we endlessly cross between the virtual and the real in our daily routine. Information saving method has changed from physical to virtual and the contents of a digital device can be a method of showing one's identity. A digital device can be seen as a virtual version of a 'wuderkammer'. With this perspective, this study focuses on the changes that has occurred in our daily interaction, the process of thinking, perceiving, and understanding in the time of 'digital wunderkammer'. In order to discuss this matter, this study looks at the two art work series - 'Universal Addressability of Dumb Things' and 'UniAddDumThs' - by a British artist, Mark Leckey and analyzes the digital environment of today, its visual expression, and the characteristic of 'digital wunderkammer' reflected in his art works. Through this study, we hope that the readers can understand the paradigm shift of today and expand the creative possibilities in this new era of digital revolution.