• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.21-24
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• 2002

A sensor array (35mm'! in diaphragm dimension) of 12 sensing elements with different operating temperatures was optimized with respect to thermal operation. This sensor array with single heater on a glass diaphragm over back-etched silicon bulk realizes a novel concept of a sensor array: an way of sensor elements operated at different temperatures can yield more information than single measurement. The proposed micro sensor array could provide well-integrated way structure because it has only single heater at the center of the diaphragm and used the various sensing properties of two kinds of metal oxide layers with various operating temperatures.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.564-568
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• 1998

All elements and systems of electronics have optimum temperature conditions. A using of the thermoelectric method of cooling is the most approach for the thermal management of power electronics. An analysis of using the thermoelectric cooling and the temperature control is given as an efficient method of ensuring a work of power electronic devices in conditions of micro-miniaturization.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6631-6636
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• 2013

Through years of effort, researchers have made notable progress in gene and microRNA fields about retinoblastoma morbidity. However, experimentally validated data for genes, microRNAs (miRNAs) and transcription factors (TFs) can only be found in a scattered form, which makes it difficult to conclude the relationship between genes and retinoblastoma systematically. In this study, we regarded genes, miRNAs and TFs as elements in the regulatory network and focused on the relationship between pairs of examples. In this way, we paid attention to all the elements macroscopically, instead of only researching one or several. To show regulatory relationships over genes, miRNAs and TFs clearly, we constructed 3 regulatory networks hierarchically, including a differentially expressed network, a related network and a global network, for analysis of similarities and comparison of differences. After construction of the three networks, important pathways were highlighted. We constructed an upstream and downstream element table of differentially expressed genes and miRNAs, in which we found self-adaption relations and circle-regulation. Our study systematically assessed factors in the pathogenesis of retinoblastoma and provided theoretical foundations for gene therapy researchers. In future studies, especial attention should be paid to the highlighted genes and miRNAs.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.567-573
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• 2014

Since the development of microelectromechanical systems (MEMS) technology for the medical field, various micro-fluid transfer systems have been studied. This paper proposes a micro-piezoelectric pump that imitates a stomach's peristalsis by using two separate piezoelectric elements, in contrast to existing micro-pumps. This piezoelectric pump is operated by using the valve-less traveling wave of peristalsis movement. If the piezoelectric plates at the two separated plates are actuated at the input voltage, a traveling wave occurs between the two plates. Then, the fluid migrates by the pressure difference generated by the traveling wave. Finite element analysis was performed to understand the mechanics of the combined system with piezoelectric elements, elastic structures, and fluids. The effects of design variables such as the chamber height and number of ceramics on the flow rate of the fluid were examined.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.337-345
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• 2023

This study analyzes considerations for satellite orbit elements for the national micro-satellite system to effectively perform its mission in accordance with the operational concept, and compares the conventionally used Walker method to improve the performance of the satellite constellation method of the repeating ground track orbit. In satellite orbit element analysis, altitude candidate values of micro-satellite system, use of eccentricity and argument of perigee through frozen orbit, necessity of selection of appropriate orbit inclination, and satellite phasing rules for flying the same repeating ground track orbit are proposed. Based on these analysis results, the superiority of the constellation method of the repeating ground track orbit compared to the Walker method is verified in terms of revisit performance analysis, global coverage characteristics, and orbit consistency.

• Journal of the Korean Home Economics Association
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• v.40 no.3
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• pp.21-40
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• 2002

The aim of this interdisciplinary study is to understand the relationship between the social behavior patterns and space elements, specially micro-housing sociological point of view. It analyzed korean typical floorplans in the apartment housing, focused on the 4-criteria contact or isolation between the individual persons, communication between the generations, hierarchy of the gender and socialization with neighbourhood. It determinate concrete space elements involved correspondent factors with users' social behavior. By reviewing those factors found, it is suggested also the planning concept, that response users' social orientation. As the practical alternatives, some prototypes have been developed not only for improvement of housing plans, but also for resonable housing supply and sustainable usage.

• Asian Journal of Atmospheric Environment
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• v.11 no.2
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• pp.122-130
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• 2017

The main purpose of the study was to clarify the properties of individual particles collected at each behavior space of a factory worker. The samplings of size-segregated ($PM_{2.1-1.1}$ and $PM_{4.7-3.3}$) indoor particles were conducted at three different behavior spaces of a factory worker who is engaged in an auto parts manufacturing plant (i.e., his home, his work place in factory, and his favorite restaurant). Elemental specification (i.e., relative elemental content and distribution in and/or on individual particles) was performed by a micro-PIXE system. Every element detected from the coarse particulate matters of home was classified into three groups, i.e., a group of high net-counts (Na, Al, and Si), a group of intermediate net-counts (Mg, S, Cl, K, and Ca), and a group of minor trace elements (P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb). The results of EF for $PM_{4.7-3.3}$ in home indicated that several heavy metals were generated from the sources within the house itself. An exceptional feature shown in the individual particles in workplace is that Cr, Mn, and Co were clearly detected in both fine and coarse particles. Cluster analysis suggested that the individual coarse particles ($PM_{4.7-3.3}$) collected at the indoor of factory were chemically heterogeneous and they modified with sea-salt, mineral, and artificially derived elements. The principal components in individual coarse particles collected at restaurant were sea-salt and mineral without mixing with harmful trace elements like chromium and manganese. Compared to the indoor fine particles of home and restaurant, many elements, especially, Cl, Na, Cr, Mn, Pb, and Zn showed overwhelmingly high net-counts in those of factory.

• Journal of Technologic Dentistry
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• v.23 no.1
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• pp.31-43
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• 2001

This study was performed to observe the micro-structure change of surface, behavior of oxide change of element, the component transformation of the alloy and the bonding strength between the porcelain interface in order to investigate effects of indium, tin on interfacial properties of porcelain fused to low gold alloy. Hardness of castings was measured with a micro-Vicker's hardness tester. The compositional change of the surface of heat-treated specimen was analyzed with an EDS and an EPMA. The interfacial shear bonding strength between alloy specimen and fused porcelain was measured with a mechanical testing system(MTS 858.20). The results were as follows: 1) The hardness value of alloy increased as increasing amount of indium addition. 2) The formation of oxidation increased as increasing indium and tin contents after heat treatment. 3) Diffusion of indium and tin elements increased as increasing indium and tin contents in metal-porcelain surface after porcelain fused to metal firing. 4) The most interfacial shear bonding strength was increased as increasing a composition of adding elements, and a heat-treatment time, and an oxygen partial pressure. From the results of this study it was found that the addition of alloying elements such as indium and tin increase hardness of as-cast alloy, produce surface oxide layer of adding elements by heat-treatment which may improve interfacial bonding strength between alloy and porcelain.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.26-31
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• 1995

A new actuating mechanism suitable for a micro positioning device is developed using piezo-electric elements. The actuator can make a step movement of 0.5 .mu. m up to 3.5 .mu. m. The step size can be adjusted on demand. By repeating this step action, long distance movement is achieved. Precise positioning can be obtained by combining the coarse motion with the maximum step size and fine motion. Two types of fine motion have been proposed for a driving method. Firstly, feedback control bases on PID is applied. The experimental results for the two method are presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.809-812
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• 2002

This paper presents the structures for a CPW shunt RF switch using MEMS(Micro Electro Mechanical System). Recent development in MEMS technology has made the design and fabrication of micro-mechanical switches as new switching elements. The micro-mechanical switches have low insertion loss, negligible power consumption, and good isolation compared to semiconductor switches. The fabricated structure shows an insertion loss of 2dB at 20GHz When a bias voltages of 12V is apply.