• Journal of KIISE:Software and Applications
• /
• v.32 no.4
• /
• pp.277-289
• /
• 2005

To overcome the long design time/high computational effort/low computational performance of phylogenetic learning featuring selection and reproduction, this paper proposes a genetic representation based on XML. Since genetic programs (GP) and genetic operations of this representation are maintained by the invocation of the built-in off-the-shelf XML parser's API, the proposed approach features significant reduced time consumption of GP design process. Handling only semantically correct GPs with standard XML schema can reduce search space and computational effort. Furthermore, computational performance can be improved by the parallelism of GP caused by the utilization of XML, which is a feasible system and wire format for migration of genetic programs in heterogeneous distributed computer environments. To verify the proposed approach, it is applied to the evolution of social behaviors of multiple agents modeling the predator-prey pursuit problem. The results show that the approach can be applied for fast development and time efficiency of GPs.

• International Journal of Oral Biology
• /
• v.32 no.3
• /
• pp.93-101
• /
• 2007

Cell behavior of the transformed cells is known to affect by interaction with extracellular matrix (ECM) proteins and integrin. To investigate the alterations of both integrin expression and cell-matrix interaction during neoplastic conversion of human oral kerationcytes, we studied expression levels of integrin subunits by flow cytometry and cellular responses to the ECM proteins in normal human oral keratinocytes (NHOKs), HPV-immortalized HOK-16B line, and three oral cancer cell lines established from HOK-16B line, CTHOK-16B-BaP, CTHOK-16B-DMBA, and CTHOK-16B-Dexa lines. The expression levels of ${\alpha}\;and\;{\beta}$ integrin subunits were shown decreased tendency in human oral keratinocytes undergoing immortalization and tumorigenic transformation except CTHOK-16B-DMBA line tested. Although ${\alpha}v{\beta}6$ integrin is known to be highly expressed in squamous cell carcinomas, and the altered integrin expression is suspected to be associated with cellular carcinogenesis, ${\alpha}v$ integrin subunit and ${\alpha}v{\beta}6$ integrin did not express in oral cancer cell lines tested. Cell behavior to the ECM proteins in HOK-16B line was generally similar to that of exponentially proliferating NHOKs. The adhesion activity profiles of type I collagen were very similar to that of its laminin counterparts, but fibronectin showed minimal adhesion activity under our conditions compared to the BSA control. The ability of the CTHOK-16B-BaP line to spread upon type I collagen and laminin markedly decreased, but migration was notably increased on type I collagen. In contrast, CTHOK-16B-DMBA and CTHOK-16B-Dexa lines spread less but migrated more upon type I collagen than immortalized HOK-16B line. These data indicate that downregulation of integrin subunits causes the changes of cellular responses to the ECM proteins during neoplastic conversion of human oral keratinocytes, and that cellular responses to the ECM proteins in oral cancer cell lines established by exposing different carcinogens are variable according to chemical carcinogens treatment.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.16 no.2
• /
• pp.75-86
• /
• 2008

In order to understand geographic genetic variation and relationship among populations of the mason bee (Osmia cornifrons Radoszkowsky), which is used as pollinator for apple tree, we sequenced a portion of mitochondrial (mt) COI gene, which corresponds to "DNA Barcode" region (658 bp) from 81 O. cornifrons individuals collected over eight localities in Korea. The sequence data revealed overall moderate to low genetic diversity within species, with a maximum sequence divergence of 0.76%. Geographically, two haplotypes (BAROC01 and BAROC02) were widespread with a frequency of 82.7%, whereas several haplotypes were found in a locality as a single individual, suggesting that haplotype distribution can be summarized as coexistence of a few widespread haplotypes and several regionally restricted haplotypes. Overall, high rate of per generation female migration (Nm=$1.1{\sim}$infinite) and low level of geographic subdivision ($F_{ST}=0{\sim}0.315$) among localities were characteristic. Although two populations (p < 0.026) were genetically subdivided from the remaining localities, no clear polarity was observed. Taken together, the nature of genetic divergence of the mason bee populations is characterized as one that possessing moderate to low genetic diversity, high gene flow, and wide spread haplotypes with ahigh frequency, concordant with the capability of dispersal in connection with the lack of historical biogeographic barriers.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.27 no.1
• /
• pp.142-158
• /
• 2013

The bumblebee, Bombus ignitus (Hymenoptera: Apidae), is a valuable natural resource that is widely utilized for greenhouse pollination in South Korea. Understanding the magnitude of genetic diversity and geographic relationships is of fundamental importance for long term preservation and utilization. As a first step, we sequenced a partial COI gene of mitochondrial DNA (mtDNA) corresponding to the "DNA barcode" region and the complete internal transcribed spacer 2 (ITS2) of nuclear ribosomal DNA from 88 individuals collected in nine South Korean localities. The complete ITS2 sequences were longest among known insects, ranging in size from 2,034 bp ~ 2,052 bp, harboring two duplicated 112-bp long repeats. The 658-bp long mtDNA sequences provided only six haplotypes with a maximum sequence divergence of 0.61% (4 bp), whereas the ITS sequences provided 84 sequence types with a maximum sequence divergence of 1.02% (21 sites). The combination of the current COI data with those of published data suggest that the B. ignitus in South Korea and China are genetically a large group, but those in Japan can be roughly separated into another group. Overall, a very high per generation migration ratio, a very low level of genetic fixation, and no discernable hierarchical population were found to exist among the South Korean populations of B. ignitus, which suggests panmixia. This finding is consistent with our understanding of the dispersal capability of the species.

• International Journal of Contents
• /
• v.13 no.2
• /
• pp.29-34
• /
• 2017

Cloud computing is becoming an effective and efficient way of computing resources and computing service integration. Through centralized management of resources and services, cloud computing delivers hosted services over the internet, such that access to shared hardware, software, applications, information, and all resources is elastically provided to the consumer on-demand. The main enabling technology for cloud computing is virtualization. Virtualization software creates a temporarily simulated or extended version of computing and network resources. The objectives of virtualization are as follows: first, to fully utilize the shared resources by applying partitioning and time-sharing; second, to centralize resource management; third, to enhance cloud data center agility and provide the required scalability and elasticity for on-demand capabilities; fourth, to improve testing and running software diagnostics on different operating platforms; and fifth, to improve the portability of applications and workload migration capabilities. One of the key features of cloud computing is elasticity. It enables users to create and remove virtual computing resources dynamically according to the changing demand, but it is not easy to make a decision regarding the right amount of resources. Indeed, proper provisioning of the resources to applications is an important issue in IaaS cloud computing. Most web applications encounter large and fluctuating task requests. In predictable situations, the resources can be provisioned in advance through capacity planning techniques. But in case of unplanned and spike requests, it would be desirable to automatically scale the resources, called auto-scaling, which adjusts the resources allocated to applications based on its need at any given time. This would free the user from the burden of deciding how many resources are necessary each time. In this work, we propose an analytical and efficient VM-level scaling scheme by modeling each VM in a data center as an M/M/1 processor sharing queue. Our proposed VM-level scaling scheme is validated via a numerical experiment.

• Journal of Korea Technology Innovation Society
• /
• v.17 no.1
• /
• pp.264-288
• /
• 2014

The competition for attracting outstanding HRST (human resource for science and technology) who can lead technological innovation is heating up all over the world. The various concepts, which are brain drain, brain gain, brain overflow, brain migration, brain circulation, are used to explain the international mobility of HRST. But the concept of brain scout is the more adequate for explaining in the case of outstanding HRST as the main cause of excessive competition for scouting. This study analyzed the critical factors of the determinants of Korean students in the USA who have intentions of returning to Korea in view of brain scout. As the first step in this study, potential factors and hypothesis are established by the interviews. As the second step, the major factors are examined by surveys and hypothesis testing. Also, a new model for decision-making is proposed which describes intentions of returning to Korea by logistic regression analysis and contributions of each factor derived from this study were compared. Finally, policy implications for attracting outstanding HRST and the limit of this study are discussed.

• Korea journal of population studies
• /
• v.31 no.2
• /
• pp.1-20
• /
• 2008

This research examines individual attitudes toward immigration and the determinants of these attitudes in Korea, Taiwan, and Japan. Using 2003 National Identity module from ISSP data, descriptive statistics showed that Taiwan seems to be the most opposed to immigration, Japan in the middle, and Korea the least opposed. Despite being the least opposed to immigration, Koreans agreed most strongly with having a homogeneous sense of ethnic identity. In addition, Korean respondents saw immigrants are being good for the national economy, but not for cultural diversity. Binary logistic regression analysis showed that age is negatively associated with the individual's attitude toward immigrants in Korea, Taiwan, and Japan. Effects of educational attainment is only significant in Taiwan. Manual worker and others, and those who work in farming, mining, and fishing tend to have negative attitudes toward increases in number of immigrants. Also, individual's values toward immigrants/immigration are related to the individual's attitude toward increases in number of immigrants in Korea, Japan, and Taiwan.

• International Journal of Oral Biology
• /
• v.42 no.3
• /
• pp.107-115
• /
• 2017

Human malignant melanoma is an aggressive skin cancer which has been rising at a greater rate than any other cancers. Although various new therapeutic methods have been developed in previous studies, this disease has properties of high proliferation and metastasis rate which remain obstacles that have lead to a poor prognosis in patients. It has been reported that a specific Lactobacillus extract has anti-cancer and -metastasis effect in vitro and in vivo. However, previous research has not specified precisely what effect the Lactobacillus rhamnosus GG (LGG) extract has had on human malignant melanomas. In this study, we showed that the LGG extract has anti-cancer and -metastasis effects on the human malignant melanoma cell lines, A375P and A375SM. At first, it was found that, while the LGG extract affects human neonatal dermal fibroblasts slightly, it induced the dose-dependent anti-cancer effect on A375P and A375SM by a WST-1 proliferation assay. As a result of a real-time PCR analysis, the expression patterns of several genes related to cell cycle, proliferation, and apoptosis were modulating in a manner that inhibited the growth of both malignant melanoma cell lines after the treatment of the LGG extract. Furthermore, genes related to the epithelial-mesenchymal transition were down-regulated, and migration rates were also decreased significantly by the LGG extract. Our study showed that the LGG extract could be used as a potential therapeutic source.

• Korean Journal of Social Welfare
• /
• v.61 no.4
• /
• pp.85-108
• /
• 2009

The quickening pace of international migration in the last twenty years brought fundamental demographic and social changes to the Korean society. Increasing number of marriage-based immigrant families imposes new challenges on social work community; however, the social work community has not been equipped with necessary practice models, sets of skills and professionals with cultural competency. This study aims to explore an integrative framework of social work practice with this client group. Research foci include the profile of marriage-based immigrant families in Korea, available social services at the time, challenges and issues they face, the compatibility of the empowerment based social work practice, and micro/mezzo/macro level concerns that arise for the effective service provision. Challenges among marriage-based immigrant families are converged into personal/familial, community related, and larger social-cultural issues. Empowerment is a multi-dimensional social process to help people gain control over their lives; a process that fosters power in people, for use in their lives, their communities and in their society. Empowerment based social work practice can be the most competent framework for working with multi-cultural families considering their multi-faceted acculturation issues while they navigate thru Korean society. Issues of educating and training of culturally competent social workers are discussed.

• International Journal of Concrete Structures and Materials
• /
• v.8 no.4
• /
• pp.289-299
• /
• 2014

Alkali-activated slag concretes are being extensively researched because of its potential sustainability-related benefits. For such concretes to be implemented in large scale concrete applications such as infrastructural and building elements, it is essential to understand its early and long-term performance characteristics vis-a'-vis conventional ordinary portland cement (OPC) based concretes. This paper presents a comprehensive study of the property and performance features including early-age isothermal calorimetric response, compressive strength development with time, microstructural features such as the pore volume and representative pore size, and accelerated chloride transport resistance of OPC and alkali-activated binder systems. Slag mixtures activated using sodium silicate solution ($SiO_2$-to-$Na_2O$ ratio or $M_s$ of 1-2) to provide a total alkalinity of 0.05 ($Na_2O$-to-binder ratio) are compared with OPC mixtures with and without partial cement replacement with Class F fly ash (20 % by mass) or silica fume (6 % by mass). Major similarities are noted between these binder systems for: (1) calorimetric response with respect to the presence of features even though the locations and peaks vary based on $M_s$, (2) compressive strength and its development, (3) total porosity and pore size, and (4) rapid chloride permeability and non-steady state migration coefficients. Moreover, electrical impedance based circuit models are used to bring out the microstructural features (resistance of the connected pores, and capacitances of the solid phase and pore-solid interface) that are similar in conventional OPC and alkali-activated slag concretes. This study thus demonstrates that performance-equivalent alkali-activated slag systems that are more sustainable from energy and environmental standpoints can be proportioned.