• Environmental Engineering Research
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• v.22 no.4
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• pp.356-362
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• 2017

This study investigates the use of methyl-esterified eggshell membranes (MESM) for the harvesting of microalgae species under various conditions. Eggshell membranes were esterified with HCl to impact polycationic characteristics. After methyl esterification, the negative surface charge property of eggshell membrane was changed from negative to positive for all pH values to improve microalgae sorption capacity. The harvesting efficiency of microalgae by MESM reached 78-99% for all pH ranges evaluated. In addition, a 150 mesh particle size and $10mg\;L^{-1}$ MESM dose were found to yield up to 98% microalgae harvesting. These results indicate that the high cationic charge of MESM strongly adsorbs the negatively-charged microalgae. MESM is biocompatible and can be applied to the harvest of microalgae.

• Proceedings of KOSOMES biannual meeting
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• 2005.11a
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• pp.91-110
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• 2005

Maritime terrorism at sea is the form of violent interference with shipping. Its global reach and negative impact on sea transportation, safety of navigation and marine environment, as well as the threat it poses to human lives and property, call for effective countermeasures at the international and national level at the same time. First, this paper gives a factual assessment of the phenomenon of maritime terrorism as well as a legal analysis of the international provisions to suppress such forms of violence at sea which is different from piracy. And also this paper attempts to address and identify issues relevant to the existing international regulations such as SUA Convention as the main source of international regulations applicable to acts of terrorism at sea, ISPS Code, PSI, etc. Finally this paper suggests the national countermeasures against maritime terrorism in light of above mentioned the definition, causes, types of maritime terrorism and concerning international regulations.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.341-342
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• 2006

A physical model for reduction of Electromagnetic Interference(EMI) or its predecessors, Radio Noise, Electrical Noise, or Radio-Frequency-Interference(RFI), is a rapidly expanding digital technology. It covers the frequency spectrum from DC to about 3 GHz EMI is the poisoner which does not allow radio, TV, radar, navigation, and a lot of electrical, electro-mechanical, and electronic and communication devices, apparatus and systems to operate compatibly in a common frequency spectrum environment EMI can result in a jammed radio, heart pacer failures, navigation errors and many other either nuisance or catastrophic events. Therefore, it follows that this spectrum pollution problem has reached international levels of concern and must be dealt with m proportion to the safety and economic impact Involved.

• Journal of Information Processing Systems
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• v.7 no.3
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• pp.435-446
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• 2011

Microprocessors are becoming increasingly vulnerable to soft errors due to the current trends of semiconductor technology scaling. Traditional redundant multi-threading architectures provide perfect fault tolerance by re-executing all the computations. However, such a full re-execution technique significantly increases the verification workload on the processor resources, resulting in severe performance degradation. This paper presents a pro-active verification management approach to mitigate the verification workload to increase its performance with a minimal effect on overall reliability. An anomaly-speculation-based filter checker is proposed to guide a verification priority before the re-execution process starts. This technique is accomplished by exploiting a value similarity property, which is defined by a frequent occurrence of partially identical values. Based on the biased distribution of similarity distance measure, this paper investigates further application to exploit similar values for soft error tolerance with anomaly speculation. Extensive measurements prove that the majority of instructions produce values, which are different from the previous result value, only in a few bits. Experimental results show that the proposed scheme accelerates the processor to be 180% faster than traditional fully-fault-tolerant processor with a minimal impact on overall soft error rate.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.182-187
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• 2003

The analysis of mud pumping which causes track irregularities during softening of present roadbed is needed in order to prepare countermeasure that is efficient and reasonable against the softening of railway roadbed. In this study, model tests were performed in order to evaluate property of the railway softening under the train loading, considering the wheel load and the impact coefficient due to the train passing velocity. The existence of the mud pumping, settlements of roadbed and vertical earth pressure were measured under the train loading.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.1
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• pp.55-62
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• 2003

This study has investigated physical and chemical properties of FRP waste, has manufactured polymer cement mortar using a crushed waste with sand and has evaluated its capability to develop the economical waste recycling technology. The study has investigated tension strength, hardness test and impact test as physical properties and also thermogravimetric characteristics and analyzed infrared spectroscope as chemical properties. Then the study has manufactured polymer cement mortar and has analyzed how the FRP waste fine aggregate replacement ratio has an effect on compression strength. Noticing admixture can complement strength drop occurred by the FRP waste fine aggregate replacement, the study examined an optimum rate of admixture addition and its reaction through electron microscope photos.

• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.61-65
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• 2013

We investigated the wearable dynamics of diamond spherical abrasive during the substrate surface polishing under the pad compression via classical molecular dynamics modeling. We performed three-dimensional molecular dynamics simulations using the Morse potential functions for the copper substrate and the Tersoff potential function for the diamond abrasive. The pad hardness had a big impact on the wearable dynamics of the abrasive. The moving speed of the abrasive decreased with increasing hardness of the pad. As the hardness decreased, the abrasive was indented into the pad and then the sliding motion of the abrasive was increased. So the pad hardness was greatly influenced on the slide-to-roll ratio as well as the wearable rate.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.142-143
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• 2006

The use of hull structural steel with heavy thickness has been enlarging due to the increase of ship volume. High heat input welding methods like EGW, FGB and SAW tandem are applied in field of ship-building. However the application of high heat input methods is clearly limited because welding method to be most widely used is semi-automatic FCAW but heat input for FCAW is limited in order to obtain impact property at low temperature. This paper will introduce the application of 30mm bead width of FCW with Ni free & low Ni content.

• East Asian Economic Review
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• v.17 no.2
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• pp.129-159
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• 2013

Over the course of the recent global financial crisis, emerging economies experienced massive swings in capital inflows. In this paper, we estimate a VAR model to assess the impact of capital inflow shocks, which are identified using a set of sign restrictions, on house prices in Korea. We base the analysis on three alternative measures of capital inflows: net total inflows, net portfolio inflows and gross total inflows. The results suggest that capital inflow shocks have a significantly positive and persistent effect on real house prices. Although shocks to capital inflows are found to be substantially more important for Korean asset markets than for other OECD countries, their overall explanatory power is modest. Using regional house price data we also show that capital inflow shocks have an asymmetric effect on property markets across the seven largest Korean cities and across different parts of Seoul.

• International Journal of Contents
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• v.8 no.3
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• pp.1-6
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• 2012

This study establishes a simple Causal Map in order to understand the structure of Social Network Services(SNS). From this, the paper proposes a simulation with drawing Simulation Model and it examines whether a Dunbar Number is available for the emergence of collective intelligence based on an on-line network. Through my analytical research, it turn out both Closed SNS and Open SNS have their own Dunbar Number. However, it appear that Open SNS can expand infinitely as it has a unique property namely weak tie. This implies that it is significant for a system or policy to be developed in order to overcome the problem of Dunbar Number, whereas restricting the extension of a network by considering the Dunbar Number would have a negative impact on emergence of collective intelligence.