• New & Renewable Energy
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• v.6 no.4
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• pp.30-40
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• 2010

Syngas from gasification of coal can be converted to SNG(Synthesis Natural Gas) through gas cleaning, water gas shift, $CO_2$ removal, and methanation. One of the key technologies involved in the production of SNG is the methanation process. In the methanation process, carbon oxide is converted into methane by reaction with hydrogen. Major factors of methanation are hydrogen-carbon oxide ratio, reaction temperature and space velocity. In order to understand the catalytic behavior, temperature programmed surface reaction (TPSR) experiments and reaction in a fixed bed reactor of carbon monoxide have been performed using two commercial catalyst with different Ni contents (Catalyst A, B). In case of catalyst A, CO conversion was over 99% at the temperature range of $350{\sim}420^{\circ}C$ and CO conversions and $CH_4$ selectivity were lower at the space condition over 3000 1/h. In case of catalyst B, CO conversion was 100% at the temperature over $370^{\circ}C$ and CO conversions and $CH_4$ selectivity were lower at the space condition over 4700 1/h. Also, conditions to satisfy $CH_4$ productivity over 500 ml/h.g-cat were over 2000 1/h of space velocity in case of catalyst A and over 2300 1/h of space velocity in case of catalyst B.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.207-210
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• 2005

Ubiquitous computing is one of the key technology areas in the "Project on Development of Ubiquitous computing and network technology" promoted by the Ministry of Science and Technology as a frontier business of the $21^{st}$ century in Korea, which is based on the new concept merging physical space and computer-based cyber space. With recent advances in Micro Electro Mechanical System (MEMS) technology, low cost and low-power consumption wireless micro sensor nodes have been available. Using these smart sensor nodes, there are many activities to monitor real world, for example, habitat monitoring, earthquake monitoring and so on. In this paper, we introduce web-based real environment monitoring system incorporating wireless sensor nodes. It collects sensing data produced by some wireless sensor nodes and stores them into a database system to analyze. Our environment monitoring system is composed of a networked camera and environmental sensor nodes, which are called Mica2 and developed by University of California at Berkeley. We have modified and ported network protocols over TinyOS and developed a monitoring application program using the MTS310 and MTS420 sensors that are able to observe temperature, relative humidity, light and accelerator. The sensed data can be accessed user-friendly because our environment monitoring system supports web-based user interface. Moreover, in this system, we can setup threshold values so the system supports a function to inform some anomalous events to administrators. Especially, the system shows two useful pre-processed data as a kind of practical uses: a discomfort index and a septicity index. To make both index values, the system restores related data from the database system and calculates them according to each equation relatively. We can do enormous works using wireless sensor technologies, but just environment monitoring. In this paper, we show just one of the plentiful applications using sensor technologies.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.135-141
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• 2024

The article examines the key constants of reengineering the modern educational cluster, associated with the processes of digital transformation of all spheres of modern socio-cultural space. The first constant is the strategic rethinking of the educational process organization and awareness of the new roles of all participants (tutors, applicants, controlling elements, etc.). The other constant involves practical re-design of the system of educational services, which consists in the reorientation from the traditional model of education functioning for society to the implementation of the educational format in the form of new projects (structural, target, business). Consequently, the purpose of the study is to highlight the attitudes relevant to the modern realities of information and technological support of education in the context of socio-economic interactions of society. The criteria for the reengineering of educational concepts and the structural organization of the educational sphere are defined. The modern world is going through a period of complete digital transformation of all spheres of public activity. The scientific intelligence notes that education is no exception in these processes, as the dependence of educational realities on information and computer technologies is now noted. The COVID-19 pandemic, for all its tragedy, was also a kind of trigger, clearly marking the new components that have become defined in the organization of the educational process. The conclusion is made that the use of digital technologies in the organization of the educational institution or in the organization of the educational process has become not an auxiliary element, but a dominant factor. Mobility, dynamism, interdisciplinarity, synergy - all these aspects are relevant for socio-economic interactions of society and should be provided by educational programs. The results of the study can be used in the reorganization processes of educational institutions and institutions. Further research requires aspects of the analysis of the foreign experience of reengineering in education, carried out taking into account digital transformations of modern sociocultural space.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.164-167
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• 1993

Telemanipulator became one of refocused fields with the help of various technology integration concerned. As one of key technologies much simpler opeartion of manipulator by operators and feedback method to operator can be counted. For such purpose virtual reality techniques are being implemented and in this paper tactile feeling among human 5 feelings will be discussed. Movement manipulation in free space and gripper manipulation methods are discussed in combination with operator's organs. Tactile signal of telemanipulator's gripper is also integrated into tactile VR control system. Such tactile VR technology is regarded as one of important roles for advanced robot technology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5963-5980
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• 2017

Image scrambling is an important technology in information hiding, where the Arnold transformation is widely used. Several researchers have proposed the application of $H{\acute{e}}non$ map in square image scrambling, and certain improved technologies require scrambling many times to achieve a good effect without resisting chosen-plaintext attack although it can be directly applied to non-square images. This paper presents a non-square image scrambling algorithm, which can resist chosen-plaintext attack based on a chaotic two-dimensional Sine Logistic modulation map and $H{\acute{e}}non$ map (2D-SLHM). Theoretical analysis and experimental results show that the proposed algorithm has advantages in terms of key space, efficiency, scrambling degree, ability of anti-attack and robustness to noise interference.

• Journal of the Korean Ceramic Society
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• v.54 no.2
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• pp.75-85
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• 2017

Thermoelectric is a key technology for energy harvesting and solid-state cooling by direct thermal-to-electric energy conversion (or vice versa); however, the relatively low efficiency has limited thermoelectric systems to niche applications such as space power generation and small-scale or high-density cooling. To expand into larger scale power generation and cooling applications such as ATEG (automotive thermoelectric generators) and HVAC (heating, ventilation, and air conditioning), high-performance bulk thermoelectric materials and their low-cost processing are essential prerequisites. Recently, the performance of commercial thermoelectric materials including $Bi_2Te_3$-, PbTe-, skutterudite-, and half-Heusler-based compounds has been significantly improved through non-equilibrium processing technologies for defect engineering. This review summarizes material design approaches for the formation of multi-dimensional and multi-scale defect structures that can be used to manipulate both the electronic and thermal transport properties, and our recent progress in the synthesis of conventional thermoelectric materials with defect structures is described.

• IMMUNE NETWORK
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• v.20 no.3
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• pp.22.1-22.21
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• 2020

In the progression of atherosclerosis, macrophages are the key immune cells for foam cell formation. During hyperlipidemic condition, phagocytic cells such as monocytes and macrophages uptake oxidized low-density lipoproteins (oxLDLs) accumulated in subintimal space, and lipid droplets are accumulated in their cytosols. In this review, we discussed the characteristics and phenotypic changes of macrophages in atherosclerosis and the effect of cytosolic lipid accumulation on macrophage phenotype. Due to macrophage plasticity, the inflammatory phenotypes triggered by oxLDL can be re-programmed by cytosolic lipid accumulation, showing downregulation of NF-κB activation followed by activation of anti-inflammatory genes, leading to tissue repair and homeostasis. We also discuss about various in vivo and in vitro models for atherosclerosis research and next generation sequencing technologies for foam cell gene expression profiling. Analysis of the phenotypic changes of macrophages during the progression of atherosclerosis with adequate approach may lead to exact understandings of the cellular mechanisms and hint therapeutic targets for the treatment of atherosclerosis.

• International Journal of Aeronautical and Space Sciences
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• v.12 no.2
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• pp.93-114
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• 2011

The current status of Canadian research on rotor-based actively controlled technologies for helicopters is reviewed in this paper. First, worldwide research in this field is overviewed to put Canadian research into context. Then, the unique hybrid control concept of Carleton University is described, along with its key element, the "stiffness control" concept. Next, the smart hybrid active rotor control system (SHARCS) projected's history and organization is presented, which aims to demonstrate the hybrid control concept in a wind tunnel test campaign. To support the activities of SHARCS, unique computational tools, novel experimental facilities and new know-how had to be developed in Canada, among them the state-of-the-art Carleton Whirl Tower facility or the ability to design and manufacture aeroelastically scaled helicopter rotors for wind tunnel testing. In the second half of the paper, details are provided on the current status of development on the three subsystems of SHARCS, i.e. that of the actively controlled tip, the actively controlled flap and the unique stiffness-control device, the active pitch link.

• Korean Institute of Interior Design Journal
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• v.13 no.2
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• pp.56-63
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• 2004

Harmony between men and their surroundings has been one of the most profound motives in space and object design for a long time. It is often expressed in design as the concept of 'organic'. Nowdays the term of organic is expanding its meaning in the contemporary sense of organicism. Nature, human 'beings, and digital technology are the key issues in future design paradigms. Karim Rashid is one of the most futuristic and vendible designer and his works show these issues. His designs flow organically and he uses materials that allow his forms to flow like the body, echoing life forms. it's very sensual, very tactile. In his work, a new concept of organic design is expressed in the organic unity of experience. He tries to contribute objects to our physical landscape that inspires, engages, and encourage positive experiences. Also, Technology is at constant play in his design process. With the latest three dimensional design software it is much easier to design and model sophisticated and complex shape and forms. Digital technology affects not only his design processes but also cultural views. New technologies and social shifts are changing our understanding of interior space.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.347-351
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• 2014

Planetary exploration rovers are likely to make a trip on a winding and sloping road of irregular surfaces to the destination in order to accomplish scientific missions. One of the key technologies for rovers is a suspension for traveling and performing exploration missions; the suspension is an essential area of technology for a stable movement of a rover. In this study, an 8-wheel suspension is designed to enable efficient climbing of slopes on a passage to the destination. For the two front wheels among the eight wheels, the moment at the pivot connecting two wheels is derived when the distance between the wheels and the torque of wheels are same. A test experiment was performed to compare the magnitude of moment according to the change in tilt angle and the position of the pivot. Finally, a suspension design considering the position of the pivot was proposed to enhance the hill-climbing performance.