• International Journal of Naval Architecture and Ocean Engineering
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• 제10권2호
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• pp.188-200
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• 2018

This paper proposes a single control strategy to solve the problem of trans-media vehicle difficult control. The proposed control strategy is just to control the vehicle's air navigation, but not to control the underwater navigation. The hydrodynamic model of a vehicle when entering water obliquely at low speed has been founded to analyze the motion characteristics. Two methods have been used to simulate the vehicle entering water in the same condition: numerical simulation method and theoretical model solving method. And the results of the two methods can validate the hydrodynamic model founded in this paper. The entering water motion in the conditions of different velocity, different angle, and different attack angle has been simulated by this hydrodynamic model and the simulation has been analyzed. And the change rule of the vehicle's gestures and position when entering water has been obtained by analysis. This entering water rule will guide the follow-up of a series of research, such as the underwater navigation, the exiting water process and so on.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1195-1200
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• 2004

We introduce an introductory engineering education course for engineering majors and non-engineering majors. This course does not require any previous knowledge and experience on engineering. It requires strong curiosities and imaginations on current and future society we live in, where technology is inseparable ingredient. Course encourages attendees to explore fundamental issues of engineering: what is proper technology and what are proper ways of exercising engineering, issues dealt in soft engineering. Since course topics cover many aspects of technology, traditional learning methods fail to be successful and efficient. Various efficient learning methods have been proposed and implemented. We utilize various interactive tangible media, which include simulated thought experiments and physical media experiences. About 20 episodes in short film format are produced based on scenario written according to related issues selected. Physical media like interactive robots are introduced for attendees' stimulated experiences. We summarize our exciting experiments on interactive teaching experiences at Pusan National University which include on/off-line interactions, assignments, projects, and evaluations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.542-547
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• 2003

A new approach to design of a discrete-time robust $H_{\infty}$ filter in finite horizon case is proposed. It is shown that robust $H_{\infty}$ filtering problem can be cast into the minimization problem of an indefinite quadratic form, which can be solved by implementing the Kalman filter defined in Krein space. The proposed filter is readily derived by simply augmenting the state space model and has the robustness property against the parameter uncertainties of a given system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.600-607
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• 2004

The paper describes the implementation of the video conferencing system using public key infrastructure which is used for user authentication and media stream encryption. Using public key infrastructure, we are able to reinforce the authentication for conference participant and block several malicious hacking while protecting conference control information. The paper shows the implementation of the transportation layer secure protocol in conformity with Korea public key authentication algorithm standard and symmetric key encryption algorithm (RC2, SEED, DES and 3DES) for media stream encryption. The feature of the paper is transportation layer secure protocol that is implemented for protection of information on a user authentication and video conference and the media streaming encryption algorithm also can be envisioned with another block encryption algorithm. The key for media streaming encryption may be safely distributed by the transportation layer secure protocol.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.437-439
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• 2002

Tangible user interfaces have attracted strong attention in the HCI(Human and Computer Interface) community for their ability to take advantage of skills humans develop in the real world. We are developing "tangible media aided design system" which employs physical objects i.e., brick as interfacing media for 3D graphic modeling. This system is targeting for persons who are afraid of experiencing 3D graphic modeling and virtual space, or have a sense of reluctance in approaching to them. Our approach suggests the easiest way for people to experience computer system and virtual space carefree while developing and improving their space sense. This work is one of initial explorations of media aided design system using tangible user interfaces.

• Journal of Contemporary Eastern Asia
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• 제19권1호
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• pp.123-143
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• 2020

This study examines the interplay between the reactions of YouTube users and North Korean propaganda. Interesting enough, the study has noticed changes in the strict media environment under young leader Kim. Messages delivered by the communist regime to the outside world appeared to resemble those of 'normal' countries. Although North Korean YouTube was led mainly by the account operator, visitors from different nations do comment on the channel, which suggests the possibility of building international communities for propaganda purposes. Overall, the study observed a sparsely connected social network among ordinary commenters. However, the operator did not exercise tight control over peer-to-peer communication but merely answered questions and tried to facilitate mass participation. In contrast to the many news clips, the documentary content on North Korea's YouTube channel did not explicitly advocate for North Korea's current political positions.

• ETRI Journal
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• 제36권2호
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• pp.232-241
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• 2014

A holographic display system with a 22-inch LCD panel is developed to provide a wide viewing angle and large holographic 3D image. It is realized by steering a narrow viewing window resulting from a very large pixel pitch compared to the wave length of the laser light. Point light sources and a lens array make it possible to arbitrarily control the position of the viewing window for a moving observer. The holographic display provides both eyes of the observer with a holographic 3D image using two vertically placed LCD panels and a beam splitter to support the holographic stereogram.

• 한국균학회지
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• 제44권2호
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• pp.100-102
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• 2016

Ergothioneine is a natural compound with strong antioxidant properties. In this study, the effects of different nitrogen sources including ammonium nitrate, ammonium sulfate, sodium nitrate, and histidine in sawdust media were investigated to enhance ergothioneine contents in Shiitake (Lentinula edodes) fruit bodies. The addition of 0.2% ammonium sulfate in the growth media showed the highest enhancement of ergothioneine content in shiitake fruit bodies which was 1.7-fold higher than the control. On the other hand, histidine, a building block of ergothioneine decreased the concentration of ergothioneine significantly. Our results demonstrate that the cultivation of shiitake in sawdust media with suitable nutrients was effective to enhance its ergothioneine contents.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.280-283
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• 1995

In centrifugal barrel finishing, it is easy to establish the optimum working conditions for different workpieces. As they are adjusted in trial and error practically, production efficiency and quality are some- times low In the present paper, firstly, installation of the barrel finishing machine, finishing purpose and working conditions have been analyzed in order to eliminate the defects of the finished surface. Secondly, on the basis of this result, quantity of the water and selection of the media and the compound, etc. have been investigated. As a result, production efficiency and quality have been improved under the specified optimum working conditions. In addition, durability of the media and the compound has been tested experimentally. As a result, it was found that the expected life of the media is about 85 hrs and that of the compound is about 5 hrs. Besides high quality control has been achieved by newly proposed inspection at regular intervals.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1789-1791
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• 2007

We fabricated OTFT-OLED display panel by using Ag-paste for source and drains electrode of OTFTs. The OTFTs were fabricated by solution processes such as spin-coating for PVP gate dielectric and screen printing for S/D electrodes with Ag-paste, except pentacene active layer which was deposited by evaporation. The mobility was 0.024 cm2/V.sec , off state current ${\sim}10-11A$, threshold voltage 7.6 V and on/off current ratio ${\sim}105$. The panel consisted of 16 x 16 pixels and each pixel consisted of 2 OTFTs, 1 Capacitor and 1 OLED. The pixels successfully worked in terms of current magnitude supplied to OLED and the control ability of driving and switching OTFTs.