• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1480-1489
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• 2024

Displacement cascade behaviors of Ti-6Al-4V alloys are investigated using molecular dynamics (MD) simulation. The embedded atom method (EAM) potential including Ti, Al and V elements is modified by adding Ziegler-Biersack-Littmark (ZBL) potential to describe the short-range interaction among different atoms. The time evolution of displacement cascades at the atomic scale is quantitatively evaluated with the energy of primary knock-on atom (PKA) ranging from 0.5 keV to 15 keV, and that for pure Ti is also computed as a comparison. The effects of temperature and incident direction of PKA are studied in detail. The results show that the temperature reduces the number of surviving Frenkel pairs (FPs), and the incident direction of PKA shows little correlation with them. Furthermore, the increasing temperature promotes the point defects to form clusters but reduces the number of defects due to the accelerated recombination of vacancies and interstitial atoms at relatively high temperature. The cluster fractions of interstitials and vacancies both increase with the PKA energy, whereas the increase of interstitial cluster is slightly larger due to their higher mobility. Compared to pure Ti, the presence of Al and V is beneficial to the formation of interstitial clusters and indirectly hinders the production of vacancy clusters.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1490-1500
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• 2024

Helium-induced defect nucleation and accumulation in polycrystalline W and W0.5 wt%ZrC (W0.5ZrC) were studied in-situ using the transmission electron microscopy (TEM) combined with 40 keV He⁺ irradiation at 800 and 1000℃ at the maximum damage level of 1 dpa. Radiation-induced dislocation loops were not observed in the current study. W0.5ZrC was found to be less susceptible to irradiation damage in terms of helium bubble formation and growth, especially at lower temperature (800 ℃) when vacancies were less mobile. The ZrC particles present in the W matrix pin the forming helium bubbles via interaction between C atom and neighbouring W atom at vacancies. This reduces the capability of helium to trap a vacancy which is required to form the bubble core and, as a consequence, delays, the bubble nucleation. At 1000 ℃, significant bubble growth occurred in both materials and all the present bubbles transitioned from spherical to faceted shape, whereas at 800 ℃, the faceted helium bubble population was dominated in W.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.5
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• pp.642-648
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• 2024

If a nation or a terrorist organization produced biological agents, they are likely stored in a form of liquid concentrate. In the present study, four chemical reagents, hydrogen peroxide, sodium dichloroisocyanurate (NaDCC), Perasafe, and DF200, were investigated on their potentials as safe, efficient and eco-friendly decontaminants for biological agents. Escherichia coli, α-amylase, and bacteriophage T4 were used as surrogate strains for biological agents. Hydrogen peroxide and DF200 showed drawbacks of a rapid heat evolution upon neutralization and thick foam building up, respectively. Perasafe was effective against E. coli and T4, but it did not inactivate α-amylase while the others were able to inactivate all three types of the surrogates. NaDCC was the most suitable decontaminant for its effectiveness against all three types of surrogates at low concentrations and being able to be neutralized without aforementioned problems.

• Journal of the Korean Geographical Society
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• v.39 no.3
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• pp.321-343
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• 2004

In principal, the original form of Eupchi landscape in Naepo reflects a traditional idea regarding direction as a connection with one's fortune and naturalization strategy of power. In reality, the weight for the landscape inside the castle town was distinct by locality according to the conditions of natural geographies and main function of the castle town. In other words, the traditional Eupchi landscape was shaped under the fixed principles but it was simultaneously reflecting the local temporality and spatiality. As Chosun Dynasty went under the Japanese colonization, Eupchi in the traditional period started to evolve into a modem city. That is to say, the traditional Eupchi as a political place became to change into the center of capital accumulation, stronghold of economy and education, and center of town beyond the function as a place for government and administration. Therefore, the process of change from the landscape of Eupchi to a modem city was a kind of revolution in the form and function, and it was also a very rapid rearrangement of social space. The disparate element of landscape and double social space worked as a vital inertial element in the urban structure of Naepo area until the post independence and evolution of landscape.

• Journal of the Korean Geographical Society
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• v.29 no.2
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• pp.117-136
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• 1994

Contemporary global space economy is so dynamic that any one specific structural force can not explain the whole dynamic processes or trajectories of spatial industrial development. The major purpose of this paper is extending the traditional notion of industrial districts to functioning and development of new industrial districts with relation to the development of high technology industries. Several dynamic forces, which are dominated in new industrial districts in the modern space economy, are incorporated in the formation and dynamic aspects of new industrial districts. Even though key forces governing Marshallian industrial district are localization of small firms, division of labor between firms, constructive cooperation, and industrial atmosphere, Marshall points out a possibility of growing importance of large firms and non-local networks in the districts with changes of external environments. Some of Italian industrial districts can be regarded as Marshallian industrial districts in broader context, but the role of local authorities or institutions and local embeddedness seem to be more important in the Italian industrial districts. More critical implication form the review of Marshallian industrial districts and Italian industrial districts is that the industrial districts are not a static concept but a dynamic one: small firm based industrial districts can be regarded as only a specific feature evolved over time. Dynamic aspects of new industrial districts are resulting from coexistence of contrasting forces governing the functioning and formation of the districts in contemporary global space economy. The contrasting forces governing new industrial districts are coexistence of flexible and mass production systems, local and global networks, local and non-local embeddedness, and small and large firms. Because of these coexistence of contrasting forces, there are various types of new industrial districts. Nine types of industrial districts are identified based on local/non-local networks and intensity of networks in both suppliers and customers linkages. The different types of new industrial districts are described by differences in production systems, embeddedness, governance, cooperation and competition, and institutional factors. Out of nine types of industrial districts, four types - Marshallian; suppliers hub and spoke; customers hub and spoke; and satellite - are regarded as distinctive new industrial districts and four additional types - advanced hub and spoke types (suppliers and customers) and mature satellites (suppliers and customers) - can be evolved from the distinctive types and may be regarded as hybrid types. The last one - pioneering high technology industrial district - can be developed from the advanced hub and spoke types and this type is a most advanced modern industrial district in the era of globalization and high technology. The dynamic aspects of the districts are related with the coexistence of the contrasting forces in the contemporary global space economy. However, the development trajectory is not a natural one and not all the industrial districts can develop to the other hybrid types. Traditionally, localization of industries was developed by historical chances. In the process of high technology industrial development in contemporary global space economy, however, policy and strategies are critical for the formation and evolution of new industrial districts. It needs formation of supportive tissues of institutions for evolution of dyamic pattern of high technology related new industrial districts. Some of the original distinctive types of new industrial districts can not follow the path or trajectory suggested in this paper and may be declined without advancing, if there is no formation of supportive social structure or policy. Provision of information infrastructure and diffusion of an entrepreneurship through the positive supports of local government, public institutions, universities, trade associations and industry associations are important for the evolution of the dynamic new industrial districts. Reduction of sunk costs through the supports for training and retraining of skilled labor, the formation of flexible labor markets, and the establishment of cheap and available telecommunication networks is also regarded as a significant strategies for dynamic progress of new industrial districts in the era of high technology industrial development. In addition, development of intensive international networks in production, technology and information is important policy issue for formation and evolution of the new industrial districts which are related with high technology industrial development.

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.271-280
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• 2010

For the next generation mobile communication system, diverse wireless network techniques such as beyond 3G LTE, WiMAX/WiBro, and next generation WLAN etc. are proceeding to the form integrated into the All-IP core network. According to this development, Beyond 3G integrated into heterogeneous wireless access technologies must support the vertical handover and network to be used of several radio networks. However, unified management of each network is demanded since it is individually serviced. Therefore, in order to solve this problem this study is introducing the theory of Common Radio Resource Management (CRRM) based on Generic Link Layer (GLL). This study designs the structure and functions to support the vertical handover and propose the vertical handover algorithm of which policy-based and MCDM are composed between LTE and WLAN systems using GLL. Finally, simulation results are presented to show the improved performance over the data throughput, handover success rate, the system service cost and handover attempt number.

• Journal of Korea Technology Innovation Society
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• v.11 no.4
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• pp.565-591
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• 2008

Using theories of sectoral innovation system and supply chain management, this paper examines the status quo of Korean IT SoC industry's innovation system by comparing it with Taiwanese one. Taiwan IT SoC industry has accomplished a rapid growth on the basis of government policies that foster domestic firms after the establishment of Hsinchu Science Park. Cooperative networks between foundries firms and fablesses have been formed within the supply chain in this process. Therefore, Taiwan industry has possessed the possibility of the coevolution in sectoral innovation system. However, Korean IT SoC industry has failed to form cooperative networks, because of weak networks between related firms. In other words, there exists an interaction failure, which is a kind of the system failure, and it means a lack of linkage between actors as a result of insufficient use of complementarities and interactive learning. Therefore, Korean industry has little possibility of the coevolution in sectoral innovation system. The cooperative networks between actors are prerequisite towards evolution of innovation system of Korean IT SoC industry. Above all, the cooperative networks between fablesses and system companies need to be strengthened within the supply chain.

• Journal of the Korean Society of Costume
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• v.46
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• pp.17-30
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• 1999

The purpose of this study is to investigate the philosophy behind the Kasaya and its evolution through its clothing material colour structure and sewing. According to the study the results were as follows. 1. The philosophy behind the dressing of the Kasaya can be found in the Therefore wearing the Kasaya symbolizes the Buddhist philosophy of Jat'ailshisongbul ("Simultaneous attaining of Buddhahood for Everyone") 2. The material symbolizes endurance and contentiment by being satisfied with any kind of clothes may they be good or bad. The material of the kasaya comes to signify the harmony among the monk's community 3. The Kasaya uses peculiar colours and the prohibits the use of the five primary and seconary colous. This is to symbolize equality wherein there is no distinction between the noble and the mean. 4. The structure of the Kasaya according the takes the form of a field The Jo is cut lengthwise and divided in nine grades following the Mahayana tradition as written in the This idea reflects the philosophy of salvation of the Pure land thought. The Je has many Jang('long') and fex Dan('short') The meaning of this is that all living beings by self-cultivation can overcome the dirty law of the secular world and follow the way of the sage who have attained their Buddha nature. 5. With respect to the sewing after finishin the sewing the Jang and the Dan are combined together representing the interdependence between the holy person and the common person. Therefore the sewing ssymbolizes the interconnection among all living beings as it arise from the "conditional causation" law. As I have shown above the philosophy behind of the Kasaya developed and was enriched as it cross over China from India to the Original Buddhist thought with which was created in India was added the richness of the Mahayana buddhist thought. As I have shown above the philosophy behind of the Kasaya developed and was enriched as it cross over China from India to the Original Buddhist thought with which was created in India was added the richness of the Nahayana Buddhist thought with which was created in India was added the richness of the Mahayana buddhist thought. As a result the Dasaya came to signify the "field image". The field-image symbolized by the kasaya came to signify the "heart-field" of all living beings. The "heart-field" by its cultivation is field with blessings. Therefore from the sanghati the Nine Grade the evolution and changes in the designs of the kasaya through the different periods of history became clearly an expression how it is possible for anybody to attend the Buddha nature. This changes also show how the Buddhist precepts became reformed from the original Buddhism.ecepts became reformed from the original Buddhism.

• Journal of The Korean Astronomical Society
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• v.36 no.3
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• pp.89-95
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• 2003

Observations of dark matter dominated dwarf and low surface brightness disk galaxies favor density profiles with a flat-density core, while cold dark matter (CDM) N-body simulations form halos with central cusps, instead. This apparent discrepancy has motivated a re-examination of the microscopic nature of the dark matter in order to explain the observed halo profiles, including the suggestion that CDM has a non-gravitational self-interaction. We study the formation and evolution of self-interacting dark matter (SIDM) halos. We find analytical, fully cosmological similarity solutions for their dynamics, which take proper account of the collisional interaction of SIDM particles, based on a fluid approximation derived from the Boltzmann equation. The SIDM particles scatter each other elastically, which results in an effective thermal conductivity that heats the halo core and flattens its density profile. These similarity solutions are relevant to galactic and cluster halo formation in the CDM model. We assume that the local density maximum which serves as the progenitor of the halo has an initial mass profile ${\delta}M / M {\propto} M^{-{\epsilon}$, as in the familiar secondary infall model. If $\epsilon$ = 1/6, SIDM halos will evolve self-similarly, with a cold, supersonic infall which is terminated by a strong accretion shock. Different solutions arise for different values of the dimensionless collisionality parameter, $Q {\equiv}{\sigma}p_br_s$, where $\sigma$ is the SIDM particle scattering cross section per unit mass, $p_b$ is the cosmic mean density, and $r_s$ is the shock radius. For all these solutions, a flat-density, isothermal core is present which grows in size as a fixed fraction of $r_s$. We find two different regimes for these solutions: 1) for $Q < Q_{th}({\simeq} 7.35{\times} 10^{-4}$), the core density decreases and core size increases as Q increases; 2) for $Q > Q_{th}$, the core density increases and core size decreases as Q increases. Our similarity solutions are in good agreement with previous results of N-body simulation of SIDM halos, which correspond to the low-Q regime, for which SIDM halo profiles match the observed galactic rotation curves if $Q {\~} [8.4 {\times}10^{-4} - 4.9 {\times} 10^{-2}]Q_{th}$, or ${\sigma}{\~} [0.56 - 5.6] cm^2g{-1}$. These similarity solutions also show that, as $Q {\to}{\infty}$, the central density acquires a singular profile, in agreement with some earlier simulation results which approximated the effects of SIDM collisionality by considering an ordinary fluid without conductivity, i.e. the limit of mean free path ${\lambda}_{mfp}{\to} 0$. The intermediate regime where $Q {\~} [18.6 - 231]Q_{th}$ or ${\sigma}{\~} [1.2{\times}10^4 - 2.7{\times}10^4] cm^2g{-1}$, for which we find flat-density cores comparable to those of the low-Q solutions preferred to make SIDM halos match halo observations, has not previously been identified. Further study of this regime is warranted.

• Journal of Korean Library and Information Science Society
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• v.50 no.2
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• pp.215-235
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• 2019

Popularly known to be originated in museums and art galleries, curation is widely applied in many other fields ranging from curation commerce to curated databases by today. Libraries also have started to provide different types of curation services such as data curation, digital curation, content curation, book curation, and social curation. However, the relationship between the curation service and the library service is not adequately studied and documented. The objective of this paper is to address that gap by analyzing the relationship between curation service and the library service. Particularly, this paper pays attention to study the relationship between curation service and library reference service. The research methods used by this study were an extensive literature review followed by some carefully selected real-world examples of curation services in libraries and other fields. The authors have analyzed and documented the origin and the meaning of two concepts, the challenges faced by library reference service, and the applicability of curation as a modest form of library reference service in the $21^{st}$-century. Based on the study findings, this paper concludes that curation service is not a new concept for the library but a natural evolution of the library reference service in response to the changing information environment and user expectations in the digital age.