• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.226-228
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• 1998

Current power systems are integrated and operated in the form of EMS/SCADA with the development of computer and communication. With this EMS/SCADA system, the production, transmission and distribution of power are effectively operated. But if the communication protocol are different from each other, it is difficult to integrate the whole system. To solve this problem, Electric Power Research Institute (EPRI) issued new standard communication protocol between control centers named Inter-Control Center Protocol (ICCP). ICCP specifies the use of Manufacturing Message Specification(MMS) for the messaging services needed by ICCP in layer 7 and support the communication between heterogeneous control centers. This study deals the characteristics of ICCP, relation between ICCP and MMS and also implements the data exchange between control centers using ICCP.

• Biomolecules & Therapeutics
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• v.10 no.4
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• pp.281-286
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• 2002

In this study, we intended to get a preliminary data for establishing rat tracheal surface epithelial(RTSE) cell culture system as an experimental model for physiology and pharmacology of tracheal epithelial cells. Primary culture on the membrane support and application of the air-liquid interface system at the level of cell layer were performed. The cell growth rate and mucin production rate were measured according to the days in culture. The results were as follows: this culture system was found to manifest mucocilliary differentiation of rat tracheal epithelial cells, the cells were confluent and the quantity of produced and released mucin was highest on culture day 9, the mucin was mainly released to the apical side and tbe free $^3{H}$-glucosamine which was not incorporated to process of synthesis of mucin was left on the basolateral side. Taken together, we suggest that air-liquid interface culture system can be used as a substitute for immersion culture system and as an experimental model for in vivo mucus-hypersecretory diseases.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05c
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• pp.437-442
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• 2002

이 논문에서는 WLAN 네트워크 환경에서 이동 호스트에게 QoS가 보장된 실시간 멀티미디어 서비스를 제공하기 위한 방법론을 제안한다. 이동무선 환경에서 MH(Mobile Host)의 이동특성은 실시간 멀티미디어 어플리케이션에게 제공되어야 하는 QoS에 심각한 영향을 주게 된다. MH의 이동성에 영향을 받지 않는 QoS를 제공하기 위해서 MH가 가까운 장래에 이동할 것으로 예상되는 영역에 미리 자원을 예약함으로서 요구되는 QoS를 제공할 수 있다. 기존의 유선환경에서 제안된 RSVP은 유선환경을 고려하여 개발된 프로토콜로써 이동무선 환경에 적용하기에는 부적절하며, 이를 개선한 MRSVP는 많은 자원의 낭비를 가져오고 있다. 본 논문에서는 기존의 MRSVP 프로토콜에 링크계층의 핸드오프 정보를 적용하여 최소한의 자원만을 예약하도록 하는 방법론을 제안한다. 이는 미리 자원을 예약하는 영역을 능동적으로 최적화함으로써 불필요한 자원의 낭비를 막고, MRSVP와 같은 수준의 QoS를 제공할 수 있다.

• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.835-844
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• 2008

ZigBee devices are limited in resources especially on power and computational capacity but also require real-time operation at MAC layer. Therefore, it is important to take those requirement into consideration of system software design. In this paper, we proposed a compact system software design to support simultaneously ZigBee and IEEE802.15.4. The design strictly respects the resource and real-time constraints while being optimized for specific functions of both Zigbee and IEEE802.15.4. Various evaluations are done to show significant metrics of our design.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.52.3-52
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• 2001

There are some problems to implement a realtime network system with Ethernet because the MAC(Medium Access Control) of Ethernet uses a CSMA/CD protocol, which introduces unexpected delays. In this paper, we designed a method to solve problems due to the Ethernet MAC. This method introduces a pseudo-MAC in application layer to support the real-time feature. So the presented method doesn´t need any modifications of protocols such as UDP/IP/MAC. The presented pseudo-MAC is based on both a token passing protocol and a publisher-subscriber protocol. The suggested realtime protocol is implemented and tested practically in a local area network. The proposed real-time network consists of a token controller node and general nodes.

• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.42-50
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• 2019

The fifth generation (5G) wireless technology is expected to be the trigger for the fourth industrial revolution. In particular, 5G ultra reliable low latency communication (URLLC) is expected to lead the wireless automation in vertical domains. In this paper, we analyze use cases, key metrics, and physical layer technologies for 5G URLLC standardized in $3^{rd}$ Generation Partnership Project Radio Access Network (3GPP RAN). Additionally, we discuss enabling RAN technologies towards beyond 5G to support high reliability and low latency.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.76-79
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• 2009

Recently there has been much effort, in both academia and industry, to integrate a plethora of wireless technologies in order to provide seamless connection to mobile users. To support seamless connection on terminal needs fast handover function and location management function. Especially, Performing fast handover has to interact with function of datalink layer and mobility based IP. In this paper, we propose a handover decision mechanism using MIH( Media Independent Handover) in hybrid networks to reduce the delay of transmission for data.

• Current Optics and Photonics
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• v.5 no.1
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• pp.23-31
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• 2021

We propose a wheel screen type Lamina 3D display, which realizes a 3D image that can satisfy the accommodation cue by projecting volumetric images encoded by varying polarization states to a multilayered screen. The proposed system is composed of two parts: an encoding part that converts depth information to states of polarization and a decoding part that projects depth images to the corresponded diffusing layer. Though the basic principle of Lamina displays has already been verified by previous studies, those schemes suffered from a bottleneck of inferior resolution of the 3D image due to the blurring on the surfaces of diffusing layers in the stacked volume. In this paper, we propose a new structure to implement the decoding part by adopting a form of the wheel screen. Experimental verification is also provided to support the proposed principle.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1167-1174
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• 2022

Cast austenitic stainless steels (CASSs) are widely used as structural materials in the nuclear industry. The main drawback of CASSs is the reduction in fracture toughness due to long-term exposure to operating environment. Even though ultrasonic non-destructive testing has been conducted in major nuclear components and pipes, the detection of cracks is difficult due to the scattering and attenuation of ultrasonic waves by the coarse grains and the inhomogeneity of CASS materials. In this study, the ultrasonic signals measured in thermally aged CASS were discriminated for the first time with the simple ultrasonic technique (UT) and machine learning (ML) models. Several different ML models, specifically the K-nearest neighbors (KNN), Support Vector Machine (SVM), and Multi-Layer Perceptron (MLP) models, were used to classify the ultrasonic signals as thermal aging condition of CASS specimens. We identified that the ML models can predict the category of ultrasonic signals effectively according to the aging condition.

• Journal of Korea Multimedia Society
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• v.25 no.3
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• pp.537-545
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• 2022

Emotional experience (James, 1884)[1] can affect people's behavior. There are few types of research on VR marketing(Maojun Zhou, Zeru Yan, 2018)[2] design based on emotional experience. This article is based on emotional evaluation theory and empirical research, and the VR marketing case "Buy+" online shopping platform (Wu Yongyi, 2016). It is concluded that there are three levels of emotional experience definition on VR marketing which decompose the features of the VR marketing design of "Buy+ as an online-shop" correspondingly and find out the design features of VR marketing from the perspective of emotional experience. Finally, through the analysis of the questionnaire data, it verified that vividness, functionality and effectiveness could represent the features of VR marketing design. Moreover, it analyzed the correlation among these factors. Vividness and functionality have the closest relationship among them. The definition, the components, and the correlation of the three-layer emotional experience obtained from this research can provide theoretical support and reference for other VR marketing designs.