• Korean Journal of Materials Research
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• v.32 no.1
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• pp.36-43
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• 2022

Breakthrough analysis has widely been explored for the dynamic separation of gaseous mixtures in porous materials. In general, breakthrough experiments measure the components of a flowing gas when a gaseous mixture is injected into a column filled with an adsorbent material. In this paper, we report on the design and fabrication of a breakthrough curve measurement device to study the dynamic adsorptive separation of hydrogen isotopologues in porous materials. Using the designed system, an experiment was conducted involving a 1:1 mixture of hydrogen and deuterium passed through a column filled with zeolite 13X (1 g). At room temperature, both hydrogen and deuterium were adsorbed in negligible amounts; however, at a temperature of 77 K, deuterium was preferentially adsorbed over hydrogen. The selectivity was different from that in the existing literature due to the different sample shapes, measurement methods, and column structures, but was at a similar level to that of cryogenic distillation (1.5).

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.25-29
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• 1997

In many solute transport studies, either flux or resident concentration has been used. Choice of the concentration mode was dependent on the monitoring device in solute displacement experiments. It would be questionable, however. to accept the equivalency in the solute transport parameters between flux and resident concentrations in structured soils exhibiting preferential movement of solute. In this study, we investigate how they differ in the monitored breakthrough curves (BTCs) and transport parameters for a given boundary and flow condition by performing solute displacement experiments on a number of undisturbed soil columns. Both flux and resident concentrations have been simultaneously obtained by monitoring the effluent and resistance of the Horizontally-positioned TDR probes. The study reveals that soil columns having relatively high flux densities exhibited great differences in the degree of peak concentration and travel time of peak between flux and resident concentrations. The peak concentration in flux mode was several times higher than that in resident one. This was mainly due to the bypassing of solute through soil macropores.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4C
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• pp.231-238
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• 2008

A column testing device capable of measuring the electrical resistivity of soil at 3 different locations was developed to verify applicability of bulk electrical conductivity (BEC) breakthrough curves in monitoring contaminant transport. Tracer injection tests were conducted with three different types of saturated sands to obtain average linear velocities and longitudinal hydrodynamic dispersion coefficients based on BEC breakthrough curves and effluent solute breakthrough curves. Comparative analysis of transport parameters obtained from curve fitting the results into the analytical solutions confirmed the validity of resistance measurements in estimating time-continuous resident solute concentration. Under the assumption that a linear relationship exists between ${\sigma}_{sat}-{\sigma}_w-C$, the BEC breakthrough curves are able to effectively reduce the laborious and time-consuming processes involved in the conventional method of sampling and analysis. In order to reduce possible uncertainties in analyzing the BEC breakthrough curves, it was recommended that resistance measurements take place nearby the effluent boundary. In addition, a sufficient electrical contrast or difference in the electrical conductivity of the influent and the saturating solution is required to conduct reliable analysis.

• Journal of Biomedical Engineering Research
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• v.44 no.4
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• pp.264-274
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• 2023

Purpose: The objective is to extract insights that can contribute to the formulation of harmonized international policies and support measures for innovative medical devices and management systems. This study aims to propose effective strategies for future medical device innovation and healthcare delivery. Results: It investigates technological advancements, regulatory approval systems, insurance policies, and successful commercialization cases in South Korea, the United States, and the European Union. In 2018, the FDA implemented insurance coverage for Software as a Medical Device (SaMD) and recognized insurance coverage for Digital Therapeutics (DTx). Germany is a country that ensures permanent reimbursement for healthcare applications since 2020, making it the first country to provide legal health insurance coverage for fostering a digital ecosystem. Conclusion: The findings of this research highlight the importance of cultivating a supportive regulatory and environmental framework to facilitate the adoption of innovative medical devices. Continuous support for research and development (R&D) efforts by companies, along with the validation of clinical effectiveness, is crucial.

• Journal of Applied Reliability
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• v.14 no.3
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• pp.147-151
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• 2014

An actuator latch device of a hard disk drive is installed for locking an actuator to hold a magnetic head parked in a parking zone. Applying an external force to the drive, the head can move away from the parking zone and destroy data on the disk. A magnet latching mechanism is used to prevent the actuator from moving when the computer is not in use. A permanent magnet holds the actuator when the head is in the parking zone. When the computer is turned on, the actuator has to overcome the latch magnet in order to move. A stronger latch magnet will hold the actuator adequately, but the actuator will not be released when unlocking is required. A breakthrough solution is needed to improve the reliability of the drive without any deterioration of its performance. In order to obtain the idea for resolving this technical contradiction, we analyse patents for actuator latch device of a hard disk drive. A practical way for solving contradictions in product development using TRIZ is proposed in this paper.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.920-923
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• 2012

Recently, a Smartphone than a normal phone functions for computing ability, connectivity and communication is used as a handheld device, as used in the mobile social networking has been a breakthrough. This advanced Smartphone social networking and social life of the everyday of people living in communication found that many were affected. In this paper, the value of Smartphones and Smartphone users who use social networking to see how any of the benefits and the future of social networking between people on the impact of communications were analyzed.

• Electrical & Electronic Materials
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• v.7 no.2
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• pp.157-164
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• 1994

DRAM(Dynamic Random Access Memory)은 반도체 소자중 가장 대표적인 기억소자로, switch역활을 하는 1개의 transistor와 data의 전하를 축적하는 1개의 capacitor로 구성된 단순한 구조와 고집적화에 용이하다는 이점을 바탕으로, supercomputer에서 가전제품 및 산업기기에 이르기 까지 널리 이용되어왔다. 한편으로 DRAM사업은 고가의 장치사업으로 조기시장 진입을 위하여 초기에 막대한 자본투자, 급속한 기술발전, 짧은 life cycle, 가격급락등이 심하여, 시한내 투자회수가 이루어져야 하는 위험도가 큰 기회사업이라는 양면성도 가지고 있다. 이러한 관점때문에 새로운 DRAM기술은 매 세대마다 끊임없이 빠른 속도로 개발되어왔다. 그러나 sub-micron이하의 DRAM세대로 갈수록 그에 대한 신기술은 점차 어렵게 되어가고, 한편으로는 system의 다양화에 따른 요구도 강하여, 이제는 통상적인 DRAM의 고집적화/저가의 전략만으로는 생존하기 어려운 실정이므로 개발전략도 수정하여야만 할 것이다. 이러한 어려운 기술한계를 극복하기 위하여 새로운 소자기술 및 공정개발에 대한 breakthrough가 이루어져야 할 것이다. 이러한 관점에서 현재까지의 DRAM개발 추이와 향후의 기술방향에 관하여 몇가지 중요한 item을 설정하여 논의해 보기로 한다.

• Journal of Sensor Science and Technology
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• v.28 no.3
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• pp.152-156
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• 2019

An ultraviolet (UV) image sensor is an extremely important optoelectronic device used in scientific and medical applications because it can detect images that cannot be obtained using visible or infrared image sensors. Because photodetectors and transistors are based on different materials, conventional UV imaging devices, which have a hybrid-type structure, require additional complex processes such as a backside etching of a GaN epi-wafer and a wafer-to-wafer bonding for the fabrication of the image sensors. In this study, we developed a monolithic GaN UV passive pixel sensor (PPS) by integrating a GaN-based Schottky-barrier type transistor and a GaN UV photodetector on a wafer. Both individual devices show good electrical and photoresponse characteristics, and the fabricated UV PPS was successfully operated under UV irradiation conditions with a high on/off extinction ratio of as high as $10^3$. This integration technique of a single pixel sensor will be a breakthrough for the development of GaN-based optoelectronic integrated circuits.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.311-311
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• 2013

The resistance switching memory devices have several advantages to take breakthrough for the limitation of operation speed, retention, and device scale. Especially, the metal-oxide materials such as ZnO are able to fabricate on the flexible and visible transparent plastic substrate. Also, the quantum dots (QDs) embedded in dielectric layer could be improve the ratio between the low and the high resistance becauseof their Coulomb blockade, carrier trap and induced filament path formation. In this study, we irradiated 0.2-MeV-electron beam on the ZnO/QDs/ZnO structure to control the defect and oxygen vacancy of ZnO layer. The metal-oxide QDs embedded in ZnO layer on Pt/glass substrate were fabricated for a memory device and evaluated electrical properties after 0.2-MeV-electron beam irradiations. To formation bottom electrode, the Pt layer (200 nm) was deposited on the glass substrate by direct current sputter. The ZnO layer (100 nm) was deposited by ultra-high vacuum radio frequency sputter at base pressure $1{\times}10^{-10}$ Torr. And then, the metal-oxide QDs on the ZnO layer were created by thermal annealing. Finally, the ZnO layer (100 nm) also was deposited by ultra-high vacuum sputter. Before the formation top electrode, 0.2 MeV liner accelerated electron beams with flux of $1{\times}10^{13}$ and $10^{14}$ electrons/$cm^2$ were irradiated. We will discuss the electrical properties and the physical relationships among the irradiation condition, the dislocation density and mechanism of resistive switching in the hybrid memory device.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.2
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• pp.1-13
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• 2011

The recent spotlight on electronic touch-screen display, a rapid breakthrough in the information society is evolving. Touch panel input device such as a keyboard or mouse without the use of, the on-screen character or a specific location or object on the person's hand touches a particular feature to identify the location of a panel is to be handled. The touch screen on the touch panel is used in the Ag paste is used mostly for low-curable paste. The thermal-curing paste according to the drying process of thermal energy consumption and improve the working environment of organic solvents have problems. In this study, Ag paste used in the non-thermal curing friendly and cost-effective UV curable paste was prepared. Current commercially available thermal-curable binder, was used instead of the flow characteristics of UV-curable oligomers and monomers with functional groups to give a single conductive Ag paste with the addition of a pattern could be formed. Ag paste as a result, thermal-curing adhesive, hardness, resistance and excellent reproduction of fine patterns and was available with screen printing environmentally friendly could see its potential as a patterning technology.