• Transactions of the Society of Information Storage Systems
• /
• v.11 no.2
• /
• pp.36-40
• /
• 2015

The demand for flexible devices including solar cells, memories and batteries has increased rapidly over the past decades. In most flexible devices, polymer-based materials are used to enable the mechanical deformations such as bending or folding. Shape Memory Polymers (SMPs) is a high molecular compound polymer with flexibility and shape recovery characteristics. In this work, flexible shape memory device was fabricated by simply coating the conducting material, carbon nano-tube (CNT), on a shape memory polymer. Furthermore, durability of the device under various type of mechanical deformations was assessed. It is believed that the result of this work will aid in realization of a stretchable and wearable electronic device for practical applications.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2229-2231
• /
• 2005

Recently, damages of electronic equipments due to lightning surges coming from AC power lines are increasing. In this work, to propose the effective installation methods of surge protective devices(SPDs), the protective performances of SPDs in actual-sized test circuits were experimentally investigated. In order to obtain the lowest limiting voltage and best protection, long leads of SPDs in installation practices are significantly undesirable. An effective installation method of SPDs for AC mains was proposed. The way of installing SPDs at every branch circuits is more effective than that of installing a SPD near the point of entry.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.1 no.2
• /
• pp.7-11
• /
• 2008

In order to enhance standardization and interoperability of local level systems, AHU control network was designed with basement(8 point) and basis story(15 point) and then the network was constructed by power line communication. Each devices of AHU system were programed with neuron C of $L_{ON}W_{ORKS}$ as an open protocol. As a result of a study, each devices of the network were controlled with self dispersion process by $L_{ON}W_{ORKS}$ protocol and wiring could be reduced by power line communication.

• Proceedings of the KAIS Fall Conference
• /
• 2003.11a
• /
• pp.113-117
• /
• 2003

As the wireless communication technology advances rapidly, a personalization technology can be incorporated with the mobile Internet environment, which is based on location-based services to support more accurate personalized services. A location-based personalized recommender system is one of the essential technologies of the location-based application services, and is also a crucial technology for the ubiquitous environment. In this paper we propose a framework of a location-based personalized recommender system for the mobile Internet environment. The proposed system consists of three modules the interface module, the neighbor selection module and the prediction and recommendation module. The proposed system incorporates the concept of the recommendation system in the Electronic Commerce along with that of the mobile devices for possible expansion of services on the mobile devices. Finally a service scenario for entertainment recommendation based on the proposed recommender system is described.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1371-1373
• /
• 2005

Nowadays, Intelligent Electronic Devices(IED) are widely used in power system. In order to improve the selectivity, sensitivity, and reliability of the power system composed by IEDs, A new fault tolerant IED system based on agent technique is presented in this paper. in the presented system, different with existing IED systems, the redundancies are drawn out from IED devices, and compose a standby backup system. And those redundancies are not specified to a particular type of IEDs. By using the agent technique, redundancies can download agents to modify their functions to fit different types of IEDs. As a conclusion, the reliability of the presented system is estimated in this paper.

• Vacuum Magazine
• /
• v.4 no.2
• /
• pp.15-23
• /
• 2017

This article reviews technical trend in research of stretchable electrodes for wearable devices, bio-integrated devices, and stretchable electronics. Stretchable electronics is new emerging class of electronics following flexible electronics. One of the most difficult challenges in the development of stretchable electronic is to realize high performance stretchable electrodes with a low resistivity and high strain failure and stretchability against severe strain of the substrate. For this reason, there are many reports on the promising stretchable electrodes including CNT, graphene, Ag nanowire, and composite materials. We outline the recent research for stretchable substrate and stretchable electrode materials to realize highly stretchable electrodes.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.15 no.8
• /
• pp.661-666
• /
• 2003

Constant area expansion devices such as capillary tubes, short tube orifices are being gradually replaced with electronic expansion valves (EEVs) because of increasing focus on comfort and energy conservation. In this study, the performance of a water-to-water heat pump as a function of refrigerant charge is investigated in steady state, cooling mode operation with expansion devices of a capillary tube and an EEV. The performance of the capillary tube system varies drastically according to the change of refrigerant charge amount and inlet temperature of the secondary fluid in the condenser. Cooling capacity and COP of the EEV system show little dependence on the refrigerant charge, while those are strongly dependent on the secondary fluid temperature at the condenser inlet. In general, for a wide range of operating conditions the EEV system shows much higher performance as compared with the capillary tube system. The performance of the EEV system can be optimized by adjusting EEV opening to maintain a constant superheat at all test conditions.

• Electronics and Telecommunications Trends
• /
• v.33 no.6
• /
• pp.1-11
• /
• 2018

Several industrial applications such as space exploration, aerospace, automotive, the downhole oil and gas industry, and geothermal power plants require specific electronic systems under extremely high temperatures. For the majority of such applications, silicon-based technologies (bulk silicon, silicon-on-insulator) are limited by their maximum operating temperature. Silicon carbide (SiC) has been recognized as one of the prime candidates for providing the desired semiconductor in extremely high-temperature applications. In addition, it has become particularly interesting owing to a Si-compatible process technology for dedicated devices and integrated circuits. This paper briefly introduces a variety of SiC-based integrated circuits for use under extremely high temperatures and covers the technology trend of SiC CMOS devices and processes including the useful implementation of SiC ICs.

• Journal of the Korea Society of Computer and Information
• /
• v.24 no.9
• /
• pp.35-42
• /
• 2019

In this paper, we propose an approach to apply network-based moving target defense into Internet of Things (IoT) networks. The IoT is a technology that provides the high interconnectivity of things like electronic devices. However, cyber security risks are expected to increase as the interconnectivity of such devices increases. One recent study demonstrated a man-in-the-middle attack in the statically configured IoT network. In recent years, a new approach to cyber security, called the moving target defense, has emerged as a potential solution to the challenge of static systems. The approach continuously changes system's attack surface to prevent attacks. After analyzing IPv4 / IPv6-based moving target defense schemes and IoT network-related technologies, we present our approach in terms of addressing systems, address mutation techniques, communication models, network configuration, and node mobility. In addition, we summarize the direction of future research in relation to the proposed approach.

• Electronics and Telecommunications Trends
• /
• v.34 no.5
• /
• pp.48-57
• /
• 2019

As the super-aged society approaches rapidly, the number of people suffering from post-stroke and other neurological disorders is significantly increasing, where prompt and intensive rehabilitation is essential for such people to resume their physical activities in normal daily lives. To overcome the inherent limitations of manual physical therapy, various types of exoskeleton robots are being employed. However, the need of the hour is softer, thinner, lighter, and even stretchable systems for precisely monitoring the motion of each joint without restricting the patients' movements in rehabilitation tasks. In this paper, we discuss the technological trends and current status of emerging stretchable rehabilitation systems, in which sensors, interconnects, and signal-processing circuits are monolithically integrated within a single stretchable substrate attachable to the skin. Such skin-like stretchable rehabilitation devices are expected to provide much more convenient, user-friendly, and motivating rehabilitation to patients with neurological impairments.