• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.897-900
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• 2006

This study concerned the quantification of environmental aggressiveness of concrete structure building up and applied to design of concrete structure. Only the content of carbon dioxide evacuated in the process of fabricating concrete structure was taken as an environmental load and various parameters, for example, material production, transportation, building-up, destruction and reuse were considered. Also, the life span of a concrete structure was taken into account in evaluating the carbon dioxide evolution. Consequently a single equation for the environmental load was obtained, which were subsequently used to assess the effect of high strength/durable concrete structures.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.106-112
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• 2008

International conferences to block the spread of Avian bird flu occurred in Beijing, 2006 and others warned of the seriousness of the H5N1 strain. The meetings succeeded in generating billions of dollars from USA, EU and World Bank. Migratory birds seem to play a major role in the spread of the aggressive strain globally from Asia to Europe and Africa. Experiences of tolerance breeding of maize (Zea mays L.) for four decades against 20 biotic stresses suggest that the prime cause of the occurrence of H5N1 strain was due to the human beings' counter-efforts against nature. Excessive use of chemicals (spray and injection) in the commercial poultry farms had created high selection pressure on virus. The new strain had mutated for survival. Attempting to eliminate the virus by chemicals for 100% control is a dangerous way to control biotic stresses. This can create more aggressive strains. A solution would be to build up tolerability of the commercial animals against the virus. Improvement of poultry cage environments and respect for nature must be integrated. Potential foes must be watched.

• Journal of the Korean Society for Heat Treatment
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• v.32 no.1
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• pp.1-11
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• 2019

In this study, microstructure evolution and crystallographic orientation are investigated under various deformation conditions in M1 magnesium alloy. M1 magnesium ingot was rolled at 673 K with the rolling reduction of 30%. The compression test specimens were machined out from rolled plate, and then the specimens were annealed at 823 K for 1h. Uniaxial compression tests were conducted at 723 K and under the strain rate ranging from $5.0{\times}10^{-4}s^{-1}$ to $5.0{\times}10^{-2}s^{-1}$ up to a true strain of -1.0. For observation of crystal orientation distribution, EBSD measurement was performed. Occurrence of the dynamic recrystallization and grain boundary migration were confirmed in all case of the specimens. The distribution of the grains is not uniformed in the experimental conditions.

• Animal Systematics, Evolution and Diversity
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• v.37 no.1
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• pp.1-8
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• 2021

A eunicid polychaete, Marphysa victori Lavesque, Daffe, Bonifácio & Hutchings, 2017 is described for the first time from the intertidal zones of the Korean coasts. It is characterized by having three types of pectinate chaetae (INS, isodont-narrow-slender; AWS, anodont-wide-slender; and AWT, anodont-wide-thick), appearance of pectinate chaetae from chaetiger 2, the chaetae consisted of pectinate and compound spinigers, and pygidium with one pair of pygidial cirri. In genetic analysis based on cytochrome c oxidase subunit I (COI), intra-specific genetic distance between the specimens of M. victori from its type locality, France and Korea are in the range of 0.000-0.013. This paper includes the morphological description and photographs of M. victori new to Korean fauna, with partial sequences of the mitochondrial COI as DNA barcode data on this species.

• Archives of Metallurgy and Materials
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• v.67 no.4
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• pp.1475-1479
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• 2022

This work mainly focuses on the sintering behavior of the Cu-Sn alloy with the addition of Ag up to 4 wt% after pulsed electric current sintering (PECS) process for ultra-fast sintering. The microstructural evolution was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and density measurements. The mechanical properties were evaluated via measurements of transverse rupture strength (TRS) and Rockwell hardness. The mechanism during the sintering process has been discussed thoroughly, and the effect on porosity with the addition of the Ag is also correlated. The results showed that the growth of porosity progressed with the amount of Ag up to 2 wt%, and further addition of Ag leads reduction in porosity. The effect on mechanical properties were improved slowly as the amount of Ag increased.

• Journal of Korea Technology Innovation Society
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• v.20 no.3
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• pp.576-606
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• 2017

It is more salient in the high-tech industry to cooperate even among competitors in order to promptly respond to the changes in product architecture. In this sense, 'co-opetition,' which is the combination word between 'cooperation' and 'competition,' is the new business term in the strategic management and represents the two concepts "simultaneously co-exist." From this view, this study set up the research purposes as follows: 1) investigating the corporate managerial and technological behavioral characteristics in the co-opetition of the global display industry. 2) verifying the emerging factors during the co-opetition behavior hereafter. 3) suggesting the strategic direction focusing on the co-opetition behavioral characteristics. To this end, this study used co-word network analysis to understand the structure in context level of the co-opetition. In order to understand topics on each network, we clustered the keywords by community detection algorithm based on modularity and labeled the cluster name. The results show that there were increasing patterns of competition rather than cooperation. Especially, the litigations for mutual control against Korean firms much more severely occurred and increased as time passed by. Investigating these network structure in technological evolution perspective, there were already active cooperation and competition among firms in the early 2000s surrounding the issues of OLED-related technology developments. From the middle of the 2000s, firm behaviors have focused on the acceleration of the existing technologies and the development of futuristic display. In other words, there has been competition to take leadership of the innovation in the level of final products such as the TV and smartphone by applying the display panel products. This study will provide not only better understanding on the context of the display industry, but also the analytical framework for the direction of the predictable innovation through analyzing the managerial and technological factors. Also, the methods can support CTOs and practitioners in the technology planning who should consider those factors in the process of decision making related to the strategic technology management and product development.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.3
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• pp.253-261
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• 2004

Game theory is mathematical analysis developed to study involved in making decisions. In 1928, Von Neumann proved that every two-person, zero-sum game with finitely many pure strategies for each player is deterministic. As well, in the early 50's, Nash presented another concept as the basis for a generalization of Von Neumann's theorem. Another central achievement of game theory is the introduction of evolutionary game theory, by which agents can play optimal strategies in the absence of rationality. Not the rationality but through the process of Darwinian selection, a population of agents can evolve to an Evolutionary Stable Strategy (ESS) introduced by Maynard Smith. Keeping pace with these game theoretical studies, the first computer simulation of co-evolution was tried out by Hillis in 1991. Moreover, Kauffman proposed NK model to analyze co-evolutionary dynamics between different species. He showed how co-evolutionary phenomenon reaches static states and that these states are Nash equilibrium or ESS introduced in game theory. Since the studies about co-evolutionary phenomenon were started, however many other researchers have developed co-evolutionary algorithms, in this paper we propose Game theory based Co-Evolutionary Algorithm (GCEA) and confirm that this algorithm can be a solution of evolutionary problems by searching the ESS.To evaluate newly designed GCEA approach, we solve several test Multi-objective Optimization Problems (MOPs). From the results of these evaluations, we confirm that evolutionary game can be embodied by co-evolutionary algorithm and analyze optimization performance of GCEA by comparing experimental results using GCEA with the results using other evolutionary optimization algorithms.

• Food Science and Preservation
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• v.10 no.1
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• pp.16-22
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• 2003

This study was conducted to find out effective MA (Modified Atmosphere) gas compositions on the oyster mushroom through statistical analysis of the respiration rate and MA storage for the various packaging materials. Under the various gas compositions, the oxygen consumption rate of oyster mushroom was from 28.9 to 161.4mgO$_2$/kg$.$hr and the carbon dioxide evolution rate was from 53.4 to 166.9 mgCO$_2$/kg$.$hr at 20$^{\circ}C$. The estimated MA condition of oyster mushroom were 2.5∼4.5%O$_2$and 11.5∼l3%CO$_2$by the RSREG(Response Surface Regression). The gas compositions of MA packaging are following that 0.03mm LDPE were 1.6∼3.0%O$_2$and 3.9∼5.3%CO$_2$,0.05mm LDPE were 1.2∼1.3%O$_2$and 9.0∼11.1%CO$_2$and Nylon+PE were 0.9∼1.2%O$_2$and 33.5∼39.6%CO$_2$. The weight loss increased at 0.03mm LDPE but has the lowest value at Nylon+PE. The hardness of pileus and stipe was decreased with storage periods. The $\Delta$E-value increased with storage period and seriously changed in early storage period at 12 and 20$^{\circ}C$. In the 0.05mm LDPE, the gas compositions of packaging were similar to estimated gas compositions from the RSREG and the storage quality was superior to the other packaging materials in weight loss, hardness, and color difference at 4, 12 and 20 $^{\circ}C$.

• Food Science and Preservation
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• v.5 no.3
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• pp.247-255
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• 1998

This study was carried out to investigate changes in the flesh firmness, evolution of ethylene, cell wall components, and degradation and solubilization of polyuronide(PU) and polysaccharide(PS) in green(GP) and mature persimmon(MP) fruits according to testing time of ethylene(50${\mu}\ell$ㆍL$^{-1}$ ). When ethylene was treated in GP and MP, flesh firmness rapidly decreased and it was decreased more GP than MP. When ethylene were treated for 12 hours in GP, production of ethylene began after 3 days. The amount of ethylene product was maximum 16,000 ${\mu}\ell$ㆍL$^{-1}$ at 24 hours of ethylene treatment. However, ethylene was not producted until 7 days after 24 hours ethylene treatment at MP. The content of pectic substances decreased in the distilled- water, 0.05M $Na_2$CO$_3$,4M and 8M KOH-soluble fractions during softening according to increasing time of ethylene treatment. Arabinose and galactose were the major non-cellulosic neutral sugars in the 0.05M CDTA and 0.05M $Na_2$CO$_3$-soluble pectic fractions. Glucose, galactose and xylose were the major non-cellulosic neutral sugars in the 4M KOH- soluble hemicellulosic fraction. High molecular of PU and PS were degraded and solubilized in the distilled-water, 0.05M CDTA 0.05M $Na_2$CO$_3$ and 4M KOH-soluble fractions during time of ethylene treatment.

• Korean Journal of Materials Research
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• v.11 no.10
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• pp.900-906
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• 2001

We prepared tunnel magnetoresistance(TMR) devices of Ta($50\AA$)/NiFe($50\AA$)/IrMn(150$\AA$)/CoFe($50\AA$)/Al ($13\AA$)-O/CoFe($40\AA$)/NiFe($400\AA$)/Ta(50$\AA$) structure which has 100$\times$100 $\mu\textrm{m}^2$ junction area on $2.5\Times2.5 cm^{2}$ $Si/SiO_2$ ($1000\AA$) substrates by a inductively coupled plasma(ICP) magnetron sputter. We fabricated the insulating layer using a ICP plasma oxidation method by varying oxidation time from 80 sec to 360 sec, and measured resistances and magnetoresistance(MR) ratios of TMR devices. We used a high resolution transmission electron microscope(HRTEM) to investigate microstructural evolution of insulating layer. The average resistance of devices increased from 16.38 $\Omega$ to 1018 $\Omega$ while MR ratio decreased from 30.31 %(25.18 %) to 15.01 %(14.97 %) as oxidation time increased from 80 sec to 360 sec. The values in brackets are calculated values considering geometry effect. By comparing cross-sectional TEM images of 220 sec and 360 sec-oxidation time, we found that insulating layer of 360 sec-oxidized was 30 % and 40% greater than that of 150 sec-oxidized in thickness and thickness variation, respectively. Therefore, we assumed that increase of thickness variation with oxidation time is major reason of MR decrease. The resistance of 80 sec-oxidized specimen was 160 k$\Omega$$\mu\textrm{m}^2$ which is appropriate for industrial needs of magnetic random access memory(MRAM) application.