• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.167-173
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• 2015

Extraction of Finger-end points is one of the most process for user multi-commands in the Hand-Gesture interface technology. However, most of previous works use the geometric and morphological method for extracting a finger-end points. Therefore, this paper proposes the method of user finger-end points extraction that is motivated a ultrared diffused illumination, which is used for the user commands in the multi-touch display device. Proposed air-mouse is worked by the quantity state and moving direction of extracted finger-end points. Also, our system includes a basic mouse event, as well as the continuous command function for expending a user multi-gesture. In order to evaluate the performance of the our proposed method, after applying to the web browser application as a command device. As a result, the proposed method showed the average 90% success-rate for the various user-commands.

• Journal of Internet Computing and Services
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• v.13 no.5
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• pp.45-53
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• 2012

The appearance of Intelligent mobile and home appliance increased the using of not only various multimedia contents but also educational contents. Especially the growth of smart device such as smart phone, smart pad and smart TV, provided the environment which everyone can use educational content anytime, anywhere, any device. However many smart devices are hard to reuse the various educational contents because the devices and mobile os policies are not unify. In this paper, we suggest the design of NeS(N-Screen e-learning system) in order to solve this problem. NeS is consisted of User Management, Educational Content Management, Content Convert System and Interactive Management System. In this system, we use the HTML5 language to assure interoperability in various Smart Device Environment. Through NeS, we can achieve Content OSMU(One Source Multi Use) in various device environment and assure the continuity of the contents for using the educational contents more easily.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1021-1028
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• 2011

The objective of this paper is to optimize the design parameters of a novel mechanism for a robotic knee orthosis. The feature of the proposed knee othosis is to drive a knee joint with independent actuation during swing and stance phases, which can allow an actuator with fast rotation to control swing motions and an actuator with high torque to control stance motions, respectively. The quadriceps device operates in five-bar links with 2-DOF motions during swing phase and is changed to six-bar links during stance phase by the contact motion to the patella device. The hamstring device operates in a slider-crank mechanism for entire gait cycle. The suggested kinematic model will allow a robotic knee orthosis to use compact and light actuators with full support during walking. However, the proposed orthosis must use additional linkages than a simple four-bar mechanism. To maximize the benefit of reducing the actuators power by using the developed kinematic design, it is necessary to minimize total weight of the device, while keeping necessary actuator performances of torques and angular velocities for support. In this paper, we use a SGA (Simple Genetic Algorithm) to minimize sum of total link lengths and motor power by reducing the weight of the novel knee orthosis. To find feasible parameters, kinematic constraints of the hamstring and quadriceps mechanisms have been applied to the algorithm. The proposed optimization scheme could reduce sum of total link lengths to half of the initial value. The proposed optimization scheme can be applied to reduce total weight of general multi-linkages while keeping necessary actuator specifications.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.495-500
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• 2018

This study examined the factors that can enhance the continuity of user experience in multi - device environment. First of all, regarding the structural difference and continuity of tasks, functional differences such as OS difference according to the characteristics of cross media, use of mouse and touch gesture were found to interfere with continuity. To increase continuity, metaphor and ambience To increase relevance and visibility. In the continuity part of visual memory and cognition, familiarity was given by the identity and similarity of visual perception elements, and it was found that familiarity factors are closely related to continuity. Finally, for the continuity of the user experience, we can see that the visibility factors as well as the meaning and layout consistency of the information are factors for the continuity of the user experience. Based on this, it was found that familiarity, consistency, and correlation were significant influences on continuity dimension of user experience, but visibility did not have a significant effect on continuity when regression analysis was conducted as factors of familiarity, consistency, correlation and visibility.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.93-98
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• 2019

Recently, with the development of the aerospace and automotive industries, the demand for high-melting-point materials has increased. However, high-melting-point materials are difficult to cut through conventional machining methods. Thermally assisted machining (TAM) is a method for improving the machinability by preheating the materials. A laser, the most commonly used device for TAM, has high efficiency through local preheating but is not sufficient for maintaining a high preheating temperature due to rapid cooling. However, the use of multi-heat sources can supplement the disadvantage of a single heat source. The high preheating temperature can be maintained with a wide and deep heat-affected zone (HAZ) by multi-heat sources. The purpose of this study is to analyze the preheating effects of multi-heat sources using laser plasma. Thermal analysis and preheating experiments were carried out. As a result, the high preheating effect of multi-heat sources compared with a single heat source was verified.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.93-100
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• 2017

In multi-media, multi-channel era, video viewing using various digital devices via the Internet, not the existing broadcasting network, is emerging as a new broadcasting viewing behavior. OTT service is regarded as the main service of this change of viewing behavior. It is a video service that can seamlessly use any content desired by the user at any time, at any time, any device, any contents, if the Internet connection is available. The purpose of this study is to investigate the factors affecting the satisfaction of OTT service by applying the technology acceptance model (TAM). As a result of analyzing through 303 questionnaires of the early users of OTT service, social pressure, perceived popularity, perceived cost, user reputation, individual innovation, and esthetics set as external factors in this study are partially affects perceived usefulness, perceived ease of use, and perceived enjoyment. In addition, perceived usefulness, ease of use, and enjoyment are directly influencing satisfaction. Based on these results, we discuss the theoretical and practical implications and propose future research direction.

• Journal of IKEEE
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• v.20 no.3
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• pp.314-317
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• 2016

Recently, efforts to maximize battery life in progress with an increase in the demand for portable devices. In this paper, we propose multi-phase buck converter with fast transient response. Multi-phase buck converter may be used for the output capacitor of small size because the ripple cancellation effect, it is possible to use an inductor having an inductance less. The portable device for quick change from standby mode to active 4-phase design structure was given a fast transient response. The proposed multi-phase buck converter was fabricated using a 0.18 um CMOS process and the supply voltage ranges from 2.7V to 3.3V, the maximum load current is 500mA and settling time is 10us.

• Progress in Superconductivity and Cryogenics
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• v.25 no.3
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• pp.13-17
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• 2023

Magnetic separation technology for small paramagnetic particles has been desired for the volume reduction of contaminated soil from the Fukushima nuclear power plant accident and for the separation of scale and crud from nuclear power plants. However, the magnetic separation for paramagnetic particles requires a superconducting high gradient magnetic separation system applied, hence expanding the bore diameter of the magnets is necessary for mass processing and the initial and running costs would be enormous. The use of high magnetic fields makes safe onsite operation difficult, and there is an industrial need to increase the magnetic separation efficiency for paramagnetic particles in as low a magnetic field as possible. Therefore, we have been developing a magnetic separation system combined with a selection tube, which can separate small paramagnetic particles in a low magnetic field. In the previous technique we developed, a certain range of particle size was classified, and the classified particles were captured by magnetic separation. In this new approach, the fluid control method has been improved in order to the selectively classify particles of various diameters by using a multi-stage selection tube. The soil classification using a multi-stage selection tube was studied by calculation and experiment, and good results were obtained. In this paper, we report the effectiveness of the multi-stage selection tube was examined.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.465-473
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• 2012

The mobile devices and cloud computing technology introduced new content services such as N-Screen service. The DRM techniques have been developed to support interoperability and multi-platform for new environment of content service. Nevertheless, it is still inconvenient for the consumers to purchase a new DRM-supported device or to migrate some purchased contents into new device due to the change of the subscription of service. Therefore, in this paper, cloud-based DRM model which is referred as DRMaaS (DRM-as-a-Service) model, is proposed to allow the consumer to freely use and move some DRM-protected contents in various smart devices regardless of subscription of service.