• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.3
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• pp.183-195
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• 2007

MEMS technology is proven to be an enabling technology to realize many components for optical networking applications. Due to its widespread applications, VOA has been one of the most attractive MEMS based key devices in optical communication market. Micromachined shutters and refractive mirrors on top of silicon substrate or on the device layer of SOI (Silicon-on-insulator) substrate are the approaches trapped tremendous research activities, because such approaches enable easier alignment and assembly works. These groups of devices are known as the planar VOAs, or two-dimensional (2-D) VOAs. In this review article, we conduct the comprehensively literature survey with respect to MEMS based planar VOA devices. Apparently MEMS VOA technology is still evolving into a mature technology. MEMS VOA technology is not only the cornerstone to support the future optical communication technology, but the best example for understanding the evolution of optical MEMS technology.

• Journal of the Semiconductor & Display Technology
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• v.19 no.1
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• pp.6-10
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• 2020

Unlike modern photography technology, in the early days, efforts to physically compose an image with a concept similar to the current photograph have not been popular or commercially successful. The limitation of the use of images as artistic media or recordings has reached the stage of introducing the technology of image analysis to automate the function that humans recognize and judge through vision. In addition, the accuracy of the image has exceeded the human visual ability, enabling the technology that enables the step of recognizing and informing the fact that the human is not aware of it. Based on such a base, the range that can be applied through the image data in the future era can be said to be unpredictable, and the technology that targets large scale image database instead of an image is also expanding the possibilities as a new application technology. In order to identify a particular image from a massive database, different methodologies have been introduced. In this paper, we discuss image identifier production methods based on multi-resolution pyramid.

• Journal of the Korean Physical Society
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• v.81
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• pp.516-524
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• 2022

Recently, three-dimensional (3D) nano-processing technology that can increase design freedom and space efficiency of devices has been being rapidly developed, and is highly expected to provide a key path for the development of next-generation optical devices. This technology has shown a high possibility of success in realizing the future devices, but still are facing many challenges in the popularization and practical application. In particular, the ability of quickly, precisely, and stably fabricating complex 3D nanostructures composed of many individual elements is strongly demanded. In recent years, the so-called four-dimensional (4D) nanofabrication technology is attracting attention. The 4D nanofabrication is achieved by applying an external force to manufactured two-dimensional nanostructures, inducing deformation in time, and then precisely transforming them into 3D nanostructures. The 4D nanofabrication technology with excellent flexibility, versatility, functionality, and reconfiguration properties provides a new paradigm enabling effectively control the mechanical, electrical, and optical properties of existing materials. In this review, we examine the conventional methods for fabricating 3D nanostructures, and then investigate 4D nanofabrication technology in detail.

• Speech Sciences
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• v.11 no.2
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• pp.181-192
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• 2004

This paper presents an efficient speech interactive agent rendering smooth car navigation and Telematics services, by employing embedded automatic speech recognition (ASR), distributed speech recognition (DSR) and text-to-speech (ITS) modules, all while enabling safe driving. A speech interactive agent is essentially a conversational tool providing command and control functions to drivers such' as enabling navigation task, audio/video manipulation, and E-commerce services through natural voice/response interactions between user and interface. While the benefits of automatic speech recognition and speech synthesizer have become well known, involved hardware resources are often limited and internal communication protocols are complex to achieve real time responses. As a result, performance degradation always exists in the embedded H/W system. To implement the speech interactive agent to accommodate the demands of user commands in real time, we propose to optimize the hardware dependent architectural codes for speed-up. In particular, we propose to provide a composite solution through memory reconfiguration and efficient arithmetic operation conversion, as well as invoking an effective out-of-vocabulary rejection algorithm, all made suitable for system operation under limited resources.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3810-3836
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• 2014

Geo-location white space spectrum databases (GL-WSDBs) are currently the preferred technique for enabling spectrum sharing between primary users and secondary users or white space devices (WSDs) in the very-high frequency (VHF) and ultra-high frequency (UHF) bands. This is true because technologies for making low-cost WSDs capable of autonomous sensing and detection of available white space (WS) spectrum are not yet feasible. This paper reviews the necessary enabling technical conditions to allow coexistence of primary and secondary systems in the VHF and UHF spectrum through a GL-WSDB approach. The practical implementation of South Africa's first GL-WSDB was performed. Results of WS channels available from five cities in South Africa calculated from the implemented GL-WSDB was compared with a commercially available GL-WSDB and was found to be 68% similar. Additionally, results from the implemented GL-WSDB were compared with measurements obtained from field spectrum scanning campaigns at two different locations in Cape Town, South Africa, and was found to be 64% similar.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1903-1909
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• 2007

As the electric power industry has been revolutionarily transformed such that the distributed energy resources have been interconnected with power systems and a variety of energy service providers have been appeared, the need of Consumer Energy Portal as a core of two-way communication and service infrastructure between power suppliers and consumers has been gradually increased. Consumer Energy Portal can be thought of as a combination of hardware and software enabling two-way communication between energy service providers and equipment within the consumers' premises or a physical and logical link between consumers' in-building networks and wide-area access networks. In other words, Consumer Energy Portal can make the way the power industry has been traditionally operated the web-based way, enabling two-way interactions between energy service providers and consumers and mutual networking between end users' equipment. Thus, Consumer Energy Portal can be a kind of Service portal that provides new value-added services and efficient power operations that in the past. In this paper, for ESPs' integrated resources management, demand side management and value-added service provision, we have established the two-way access network that can gather real-time metering data using ZigBee technology and control physically networked equipment.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.379-382
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• 2007

Laser scanning technology with high positional accuracy and high density automation will be widely applied in vast range of fields including geomatics. Especially, the development of laser scanning technology enabling long range information extraction is increasing its full use in civil engineering. The purpose of this study is to extract accurate highway geometric information taking the advantages of scanning technology. Fulfilling this goal, the information of target highway's three-dimensional data was obtained through terrestrial laser scanning technology. In accordance with the result from target highway's geometric information extraction using the information above, laser scanning technology showed faster speed and better accuracy on highway geometric information extraction with reduced cost compared to traditional methods.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.317-324
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• 2009

Tactical Information Communication Network(TICN) uses both a wireless and wired network. To support mobility in battlefield environments, the application of Ad-hoc networking technology to its wireless communication has been examined. However, Ad-hoc network is faced to many security threats due to its intrinsic characteristics. Therefore, to apply the Ad-hoc networking technology to battlefield environments and TICN, an intensive study on security countermeasure must go side by side with the development of enabling technology. In this paper, we suggest an efficient key management scheme for TICN of which the Ad-hoc networking technology is applied.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1758-1760
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• 2008

Under typical operating conditions, flows in microfluidic devices are laminar and molecular diffusion across the channels is slow, which makes an efficient mixing in microfluidic devices difficult to achieve. The mechanism to achieve effective mixing in laminar flows is that of repetitive stretching and folding. Essential is to generate spatially periodic flows with crossing cross sectional streamlines. A mapping method is employed to analyze mixing in micromixers, enabling us to investigate the progress of mixing both qualitatively and quantitatively. The progress of mixing is characterized by a measure of mixing, called the discrete intensity of segregation. The mapping method is applied to mixing in such micromixers as the staggered herringbone mixer, the barrier embedded micromixer, and the three-dimensional serpentine channel to demonstrate the capability of the numerical scheme to tackle general mixing problems in microfluidic devices.

• Journal of Korea Technology Innovation Society
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• v.6 no.4
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• pp.492-507
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• 2003

Material is enabling technology that creates the product performance and the service of most industrial sectors and fields of technology. However, compared to the other fields such as IT, BT, and NT etc., relatively little attention has been paid to the research on strategy and innovation of materials technology. This bias should have resulted in the misfit of policy and less than enough investment in materials innovation. This paper discusses the characteristics, process, and future of the materials innovation. The process and status of materials technology in Korea are analyzed based on the discussions above. Finally, some suggestions for R＆D strategies of Korea are presented on the basis of the nature, trend and barriers of materials innovation.