• 한국주조공학회지
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• 제38권1호
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• pp.16-26
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• 2018

In this study, the effects of the pouring temperature, preheating temperature, surface condition and fraction of the wear resistant part on the production of duo-castings were investigated using a high Cr white cast iron with excellent abrasion resistance and a low Cr alloy steel with good toughness. The constituent materials of the duo-castings were designed to have high hardness, fracture toughness and abrasive wear resistance for the replacement of high Mn alloy steels with low abrasive wear resistance. In particular, the amount of abrasive wear of 17% Cr white cast iron was about 1/20 of that of high Mn alloy steel. There was an intermediate area of about 3mm due to local melting at the bonding interface of the duo-castings. These intermediate regions were different from those of the constituent materials in chemical composition and microstructure. This region led to fracture within the wear resistant part rather than at the bonding interface in the bending strength test. The bending fracture strengths were 516-824 MPa, which were equivalent to the bending proof strength of high Mn steel. The effects of various casting conditions on the duo-cast behavior were studied by simple pouring of low Cr alloy steel melt, but the results proved practically impossible to manufacture duo-castings with a sound bonding interface. However, the external heating method was suitable for the production of duo-castings with a sound bonding interface.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 춘계 종합학술대회 논문집
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• pp.443-447
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• 2005

텔레매틱스를 위한 임베디드 이동체 자동화시스템(EMAST : Embedded Mobile Automatic System for Telematics)인 EMAST는, CAN(Controller Area Network)과 ARM Processor를 이용한 임베디드 이동체 자동화 시스템을 단일 칩(System-on-Chip)으로 구현된다. EMAST가 범용적으로 사용되기 위해서는 다음 두 조건을 만족해야만 한다. 첫째, 이동체 내부 인터페이스는 Differential Transceiver와 Optical Transceiver, Wireless Transceiver를 지원하도록 설계되어야하며, 둘째, EMAST와 텔레매틱스 망을 사용하는 단말기들 간의 인터페이스를 지원해야만 한다. 본 논문에서는 텔레매틱스를 위한 임베디드 이동체 자동화 시스템 구조 및 EMAST와 이동체각 Unit들과의 효율적인 인터페이스 구조를 제안하였다.

• 정보와 통신
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• 제11권4호
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• pp.62-70
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• 1994

본고는 교환기의 기본구조를 변경하지 않고 프레임릴레이를 통하여 ISDN(Intergrated services digital network) 교환기에 물리적으로 적용 가능한 LAN(Local area network) 인터페이스 기술에 대하여 서술하였다. 프레임릴레이의 구현을 위해 기존 X.25 서비스와의 상호접속 방안이 매우 중요한데 이를 위해서는 X.75 및 I.122를 배경으로 하는 상호적인 방안이 고려되어야 한다. 프레임릴레이 서비스에 필요한 특징 및 트로토콜, 브릿지 상호접속 및 ISDN 노드에 사용되어 프레임 수행을 위한 프레임핸들러의 설계방법에 이어, 프레임릴레이를 통한 LAN과 ISDN간 상호접속 메카니즘에 대해 각각 서술하였다. 그리고 프레임릴레이를 통하여 LAN을 위한 고속 프레임릴레이 서비스를 구현한 주요국의 사례를 살펴보았다.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.217-230
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• 2012

To look at Korea trade environment, as increasing the quantity of goods transported in North-East Asia and deepening national competitive, information-oriented logistics environment is needed. That means it is automated work process and can provide value-added service. To do this, logistics business can be efficiently handled through "Electronic Means for the Clearance of Ships" and electronically data processing. Also, by increasing the risk of international terrorism, regulation regarding to logistics security has strengthened around the advanced country, such as USA and EU, etc. or international organization, such as IMO, ISO, etc.. Furthermore, because trade and logistics environment is changing and security becomes more important in logistics area, movement or status information of goods within the port or in entry in/out becomes more and more be needed in real time. In case cross-border logistics activities, international cooperation or agreement between countries is very important. However, different opinions much happened on defining the interface. If to follow one format or type using at a specific country or organization, it was occurred to difficulty in respect of interoperability as well as additional costs or time. Therefore, this paper proposes common interface model to exchange information for the efficient global SCM for using by the output of Korea R&D project, "National Logistics Standardization System Development".

• 대한임베디드공학회논문지
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• 제9권4호
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• pp.237-243
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• 2014

In this paper we present an real-time obstacle avoidance technique of autonomous mobile robot with steering system and implementation of user interface for mobile devices with Android platform. The direction of autonomous robot is determined by virtual force field concept, which is based on the distance information acquired from 5 ultrasonic sensors. It is converted to virtual repulsive force around the autonomous robot which is inversely proportional to the distance. The steering system with PD(proportional and derivative) controller moves the mobile robot to the determined target direction. We also use PSD(position sensitive detector) sensors to supplement ultrasonic sensors around dead angle area. The mobile robot communicates with Android mobile device and PC via Ethernet. The video information from CMOS camera mounted on the mobile robot is transmitted to Android mobile device and PC. And the user can control the mobile robot manually by transmitting commands on the user interface to it via Ethernet.

• Journal of Information Processing Systems
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• 제4권4호
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• pp.133-144
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• 2008

Clusters have become a popular alternative for building high-performance parallel computing systems. Today's high-performance system area network (SAN) protocols such as VIA and IBA significantly reduce user-to-user communication latency by implementing protocol stacks outside of operating system kernel. However, emerging parallel applications require a significant improvement in communication latency. Since the time required for transferring data between host memory and network interface (NI) make up a large portion of overall communication latency, the reduction of data transfer time is crucial for achieving low-latency communication. In this paper, Eager Data Transfer (EDT) mechanism is proposed to reduce the time for data transfers between the host and network interface. The EDT employs cache coherence interface hardware to directly transfer data between the host and NI. An EDT-based network interface was modeled and simulated on the Linux-based, complete system simulation environment, Linux/SimOS. Our simulation results show that the EDT approach significantly reduces the data transfer time compared to DMA-based approaches. The EDTbased NI attains 17% to 38% reduction in user-to-user message time compared to the cache-coherent DMA-based NIs for a range of message sizes (64 bytes${\sim}$4 Kbytes) in a SAN environment.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2004년도 추계 학술발표회 논문집
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• pp.133-138
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• 2004

Proton exchange membrane fuel cell (PEMFC) is considered as a clean and efficient energy conversion det ice for mobile and stationary applications. Anions all the components of the PEMFC, the interface between the electrolyte ,and electrode catalyst plays an important role in determining tile cell performance since the electrochemical reactions take place at the interface in contact with tile reactant gases. Therefore, to increase the interface area and obtain a high-performance PEMFC, surface of the electrolyte membrane was roughened by Ar$^{+}$ beam bombardment. The results imply that by modifying surface of the electrolyte membrane, platinum loading can be reduced significantly without performance loss. To optimize the surface treatment condition, effects of ion dose density on characteristics of the membrane/electrode interface were examined by measuring the cell performance, impedance spectroscopy, and cyclic voltammograms. Surface of the modified membranes were characterized using scanning electron microscopy and FT-IR.R.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.246-246
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• 2012

Smart catalyst design though novel catalyst preparation methods can improve catalytic activity of transition metals on reducible oxide supports such as titania by enhancement of metal oxide interface effects. In this work, we investigated Pt nanoparticles/titania catalysts under CO oxidation reaction by using novel preparation methods in order to enhance its catalytic activity by optimizing metal oxide interface. Arc plasma deposition (APD) and metal impregnation techniques are employed to achieve Pt metal deposition on titania supports which are prepared by multi-target sputtering and Sol-gel techniques. In order to tailor metal-support interface for catalytic CO oxidation reaction, Pt nanoparticles and thin films are deposited in varying surface coverages on sputtered titania films using APD. To assess the role of oxide support at the interface, APD-Pt is deposited on sputtered and Sol-gel prepared titania films. Lastly, characteristics of APD-Pt process are compared with Pt impregnation technique. Our results show that activity of Pt nanoparticles is improved when supported over Sol-Gel prepared titania than sputtered titania film. It is suggested that this enhanced activity can be partly ascribed to a very rough titania surface with the higher free metal surface area and higher number of sites at the interface between the metal and the support. Also, APD-Pt shows superior catalytic activity under CO oxidation as compared to Pt impregnation on sputtered titania support. XPS results show that bulk oxide is formed on Pt when deposited through impregnation and has higher proportion of oxidized Pt in the form of $Pt^{2+/4+}$ oxidation states than Pt metal. APD-Pt shows, however, mild oxidation with large proportion of active Pt metal. APD-Pt also shows trend of increasing CO oxidation activity with number of shots. The activity continues to increase with surface coverage beyond 100%, thus suggesting a very rough and porous Pt films with higher active surface metal sites due to an increased surface area available for the reactant CO and $O_2$ molecules. The results suggest a novel approach for systematic investigation into metal oxide interface by rational catalysts design which can be extended to other metal-support systems in the future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.258-260
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• 2006

In this paper, we designed a embedded system that will perform a primary role of Tangible Space implementation. This hardware includes function of image capture through camera interface, image process and sending off image information by LAN (local area network) or WLAN(wireless local area network). We define this hardware as a network based Visual Agent Platform for Tangible Space

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.172-174
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• 2007

In this paper, we designed a embedded system that will perform a primary role of Tangible Space implementation. This hardware includes function of image capture through camera interface, image process and sending off image information by LAN(local area network) or WLAN(wireless local area network). We define this hardware as a network based Visual Agent Platform for Tangible Space, This Visual Agent Platform includes the software that is RTLinux and CORBA