• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.735-742
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• 2019

In this work, the electrokinetic interactions between the undulated structure of an ion-selective membrane and electroconvective instability has been studied using numerical analysis. Using finite element method, electric field-ionic species transport-flow field were analyzed by fully-coupled manner. Through the numerical study, the Dukhin's mode as the mechanism of undulated surface for the electroconvective instability were proven. The Dukhin's mode which competes with Rubinstein's mode has roles of (i) decreasing transition voltage to overlimiting regime and (ii) non-linearly increasing of overlimiting current. Also, (iii) the mixing efficiency is enhanced by removal mechanism of high-frequency Fourier mode of the electroconvective instability. Conclusively, the undulated ion-selective surface would provide energy-efficient mechanism for ion-selective transport systems such as electrodialysis, electrochemical battery, etc.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.2
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• pp.115-120
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• 2004

A bulk liquid membrane system was introduced for selective separation of an amino acid mixture. We confirmed p-diamethylaminobenzaldehyde (DAB), sulfosalicylic acid (SSA) and 1-naphtol were very useful carriers for selective separation of an amino acid mixture. As a result, Ala, Leu, Val, Phe and Ile were successfully separated by SSA, 1-naphtol in basic condition, 1-naphtol in weak acidic condition, DAB in strong acidic condition and DAB in strong basic condition. The separation mechanism was proposed by ion pair mechanism in the case of SSA and 1-naphtol and Imine bond formation mechanism was also introduced for DAB.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.5
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• pp.94-100
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• 1994

The junction failure mechanism of W plugs has not been fully understood while the selective W deposition has been widely used for plugging interconnection lines. In this paper, the thermal stability and junction failure mechanism of sub-micron contacts using selective CVD-W plugs were intensively studied with the metal lines of AISiCu, Ti/AISiCu and TiN/AISiCu. The experimental results showed that the contact chain resistance and leakage current in the AISiCu and Ti/AISiCu metallizations were significantly degraded after annealing. From the SEM analysis, it was found that the junction spiking, due to the Al atoms diffusion along the porous interface between selective CVD-W and contactside wall, caused the junction failure. In constast, there was no degradation of the contact resistance and junction leakage current in TiN/AISiCu metal structu-re. It is believed that the TiN barrier layer could prevent AI(Ti) atoms Fromdiffusing. Therefore, TiN barrier between W plug and Al should be used to impro-ve the thermal stability of sub-micron contacts using the selective CVD-W plugs.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.5
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• pp.338-344
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• 2014

As the role of information collection becomes increasingly important in the enormous data environment, there is growing demand for more intelligent information technologies for managing complex data. On the other hand, it is difficult to find a solution because of the data complexity and big scaled amount. Accordingly, there is a need for a special intelligent knowledge base frame that can be operated by itself flexibly. In this paper, by adopting switching function for signal transmission in the synapse of the human brain, I/E selective activation based knowledge reconfiguring mechanism is proposed for building more intelligent information management system. In particular, knowledge network design, a special knowledge node structure, Type definition, I/E gauge definition and I/E matching scheme are provided. Using these concepts, the proposed system makes the functions of activation by I/E Gauge, selection and reconfiguration. In a more efficient manner, the routing and reasoning process was performed based on the knowledge reconfiguration network. In the experiments, the process of selection by I/E matching, knowledge reconfiguration and routing & reasoning results are described.

• Molecules and Cells
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• v.43 no.8
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• pp.686-693
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• 2020

Autophagy is an intracellular degradation system that breaks down damaged organelles or damaged proteins using intracellular lysosomes. Recent studies have also revealed that various forms of selective autophagy play specific physiological roles under different cellular conditions. Lipid droplets, which are mainly found in adipocytes and hepatocytes, are dynamic organelles that store triglycerides and are critical to health. Lipophagy is a type of selective autophagy that targets lipid droplets and is an essential mechanism for maintaining homeostasis of lipid droplets. However, while processes that regulate lipid droplets such as lipolysis and lipogenesis are relatively well known, the major factors that control lipophagy remain largely unknown. This review introduces the underlying mechanism by which lipophagy is induced and regulated, and the current findings on the major roles of lipophagy in physiological and pathological status. These studies will provide basic insights into the function of lipophagy and may be useful for the development of new therapies for lipophagy dysfunction-related diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.45-51
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• 2019

Modern file systems have journaling mechanism to maintain their stored state consistently even under unexpected system crashes or disasters. However, the journaling makes I/O throughput lower. This performance degradation comes from the ordering mechanism between the data buffer and metadata buffer and two-staged buffer writing. Especially, if the data buffer and metadata buffer are journalled at the same time, then it incurs significant performance degradation due to the two-staged writing. That shows the trade-off relation-ship between I/O performance and system reliability. In this paper, we propose RFJ: a reliable and fast jour-naling mechanism to deal with this trade-off relationship. We propose an ordering enforced writeback journaling mode and selective journaling mechanism. The Ordering enforced writeback journaling mode achieves low I/O latency and the selective journaling mechanism achieves high reliability. The experimental result shows that the performance of RFJ is almost 5x faster than the journal mode of Ext3 file system but it still supports the same reliability with the journal mode.

• Korean Journal of Materials Research
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• v.16 no.5
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• pp.323-328
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• 2006

In situ electrical conductivity measurements on $V_2O_5WO_3/TiO_2$ catalysts were carried out at between 100 and $300^{\circ}C$ under pure oxygen, NO and $NH_3$ to investigate the reaction mechanism for ammonia SCR (selective catalytic reduction) de NOX. The electrical conductivity of catalysts changed irregularly with supply of NO. It was, however, found that the electrical conductivity change with ammonia supply was regular and the increase of electrical conductivity was mainly caused by reduction of the labile surface oxygen. The electrical conductivity change of catalysts showed close relationship with the conversion rate of NOx. Variation of conversion rate in atmosphere without gaseous oxygen also showed that labile lattice oxygen is indispensable in the initial stage of the de NOx reaction. These results suggest that liable lattice oxygen acts decisive role in the de NOx mechanism. They also support that de NOx reaction occurs through the Eley?Rideal type mechanism. The amount of labile oxygen can be estimated from the measurement of electrical conductivity change for catalysts with ammonia supply. This suggests that measurement of the change can be used as a measure of the de NOx performance.

• Journal of the Korean Ceramic Society
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• v.30 no.10
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• pp.819-822
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• 1993

The purpose of this paper is a investigation of sensing mechanism for the carbon monoxide gas in CuO infiltrated ZnO ceramics. Potential barriers between CuO and ZnO can explain the selective sensing of carbon monoxide gas in the physically contacted CuO/ZnO ceramics. A specimen having no potential barrier between CuO and ZnO was prepared to see whether the gas sensing mechanism is related to the potential barrier. CuO and ZnO was prepared to see whether the gas sensing mechanism is related to the potential barrier. CuO was painted on the non electrode sides of ZnO ceramics. The CuO painted ZnO ceramics showed that the sensitivityfor the carbon moxnoxide gas was 1.3 times as high as that for the hydrogen gas. It is almost same gas sensitivity as that of the CuO infiltrated ZnO ceramics.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1728-1732
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• 2005

Gear trains are used in many machinery for variable speed ratios. Typical shapes of gear trains are two categories: simple gear trains and planetary gear trains. Generally the methods of the design typical shapes are two way. One of the methods is trailblazing design and the other is selective design in available types. This paper presents the mechanism types when input rotating velocity and output rotating velocity are maintained for useful planetary gear reducers of twelve types. Also, this paper gives the applicable example about rotating velocity of the gear axis, carrier velocity and the organized gear specifications

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.3
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• pp.223-231
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• 2008

This paper introduces a robot called the MRINSPECT V (Multifunctional Robotic crawler for Inpipe in-SPECTion V) for the inspection of pipelines with a nominal 8-in inside diameter. Based on the mechanism of the previous model MRINSPECT IV, we developed a new MRINSPECT V by using the differential driving mechanism, so that just simply controlling the speed of each driving units helps the robot to travel effectively inside the pipelines. Furthermore, the robot uses clutches in transmitting driving power to wheels. This clutch mechanism enables MRINSPECT V to select the suitable driving method according to the shape of pipeline. In this paper, the critical points in design and construction of the proposed robot are described with the preliminary results to provide good mobility and increase the efficiency.