• Title/Summary/Keyword: evolutionary approach

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A Process Model for Virtual Collaboration: Theoretical Synthesis and Empirical Exploration (가상협업을 위한 프로세스 모형)

  • Suh, A-Young;Shin, Kyung-Shik
    • Asia pacific journal of information systems
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    • v.18 no.2
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    • pp.73-94
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    • 2008
  • When individuals collaborated in virtual settings, communication is medicated through a variety of communication technologies, and is associated not only with communication effectiveness but also with socio-emotional interactions among group members. In this regards, scholars have examined how technology-mediated communication systems can be designed and used to facilitated communication interaction. However, the empirical results of the previous studies have revealed inconsistencies in the effects of communication media on users' behavioral or attitudinal responses, and on their viable effectiveness in organizations. Some studies claim that computer-mediated communication(CMC) is task-oriented but not suitable for emotional expression since it hinders close interpersonal interaction. On the other hand, some studies argue that individuals are able to develop interpersonal relationships more effectively in a CMC environment than in an FtF-environment. Due to the different perspectives, a theoretical gap exists, and it leads to the inconsistent research findings. The purpose of this paper is to combine the two different perspectives into single unified model, thereby providing a more realistic and comprehensive understanding about virtual collaboration. The present study here sought to answers the following questions with organizational communication perspective: What are the major components of virtual collaboration? What factors affect the performance of virtual collaboration? And what kind of managerial efforts should organization make in order to facilitate CMC media effectiveness in virtual collaboration? Although there is a certain belief that new media, namely technology-mediated communication support would create new opportunities, the problem of "how" or "why" has been an important question that is still not fully addressed. In this regards, we collectively reexamined previous literatures with major issues which are still controversial and integrated various theoretical activity within computer-mediated communication domain: task-oriented approach, socio-emotional approach, and evolutionary psychological approach. Our first contribution is to develop a framework for virtual collaboration by combining two different perspectives into a single unified model, providing a more realistic and comprehensive understanding. The second main contribution is the joint modeling of both social presence and cognitive effort, and the effects on two distinct but important communication outcomes(i.e., take performance and relational development). We tested the research hypotheses which were developed based on the various CMC theories using data gathered through a self-administered mail survey of 127 individuals of 69 virtual workgroups. The proposed model was supported, providing preliminary evidence that the tension between two opposite view should be integrated. The results show that the individual's psychological processes(social presence and cognitive effort) in a virtual environment significantly mediated the effect of CMC inputs (media richness, user adaptation, and shared contest) on the CMC outputs (task performance and relational development). Furthermore, this study shows that the lack of perceived media richness of CMC media can be complemented by user adaptation and shared context. Based on the results, we discuss how communication system should be designed and implemented so as to promote virtual interaction as well as how a virtual workgroup should be composed to complement the lack of media richness. A virtual collaboration using CMC media may create new value by overcoming the logistical constraints. On the other hand, it may also generate various managerial risks such as communicational depersonalization, process dissatisfaction, and low cohesion. Therefore, this study suggests that organization managers should carefully choose the CMC mediums and monitor individual member's cognitive and affective psychological processes during virtual collaboration to reduce potential risks in virtual collaboration.

Ecological Evolution by Competitive Exclusion / An Experimental Approach with Cellular Slime Mold , Polysphondylium pallidum (경쟁배타에 의한 생태적 진화: 세포성 점균 Polysphondylium pallidum에 대한 실험적 접근)

  • ;Robert M. Eisenberg
    • The Korean Journal of Ecology
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    • v.17 no.3
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    • pp.299-310
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    • 1994
  • Intraspecific clonal interactions have important influences on a population structure of the cellular slime mold (CSM). This study was to investigate whether or not evolutionary change in a population could be induced by clonal competition, and to elucidate how various clones in a population evolve in a homogeneous environment of laboratory culture. The characteristic clones of Polysphondylium pallidum which had different resource consumption rates (RCR) and mating types I and II were selected for study. Investigation was conducted for 4 experimental time interval $(T_0-T_4)$; one experimental time interval took almost 10-14 days from inoculation to havest of fruiting bodies. Two sets of 50 clones were cultured from 50 clones at To, and RCR variations of the population were compared between $(T_0\;and\;T_4)$ for each set of clones. Each clone of the CSM had a diverse resource consumption rate, or growth rate, in a homogeneous and limited Cerophyl agar plate despite the passage of 48-56 generations from the beginning of the experiment. Diverse clones with different growth rate could coexist in one site of the homogeneous agar plate as well as heterogeneous soil microenvironment. When there was high clonal diversity of RCR, a clone in a population had high chances to encounter other clones with resultant increased clonal competition. In one set, 26 of 37 clones of mating type I were changed to mating type Il for the 4 experimental time intervals, which indicated that the rate of competitive exclusion among clones during total experiment from $(T_0\;to\;T_4)$ was 0.703. In another set, 31 of 37 clones of mating type I were changed to mating type II , having the rate of competitive exclusion 0.838. The frequency of each of mat~ng types changed by 0.93-1.29% in each successive generation. The competitive exclusion among clones occurred by 1.26-1.75% when approximately $2.6{\times}10^8$ bacterial cells were provided as food and thereafter one generation of myxamoebae of CSM elapsed at room temperature. This finding implicated that in the vegetative state of P, pallidurn there was 1.26-1.75% probabil~ty of evolutionary change per generation changing from one clone to another clone.

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Hypernetwork Classifiers for Microarray-Based miRNA Module Analysis (마이크로어레이 기반 miRNA 모듈 분석을 위한 하이퍼망 분류 기법)

  • Kim, Sun;Kim, Soo-Jin;Zhang, Byoung-Tak
    • Journal of KIISE:Software and Applications
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    • v.35 no.6
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    • pp.347-356
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    • 2008
  • High-throughput microarray is one of the most popular tools in molecular biology, and various computational methods have been developed for the microarray data analysis. While the computational methods easily extract significant features, it suffers from inferring modules of multiple co-regulated genes. Hypernetworhs are motivated by biological networks, which handle all elements based on their combinatorial processes. Hence, the hypernetworks can naturally analyze the biological effects of gene combinations. In this paper, we introduce a hypernetwork classifier for microRNA (miRNA) profile analysis based on microarray data. The hypernetwork classifier uses miRNA pairs as elements, and an evolutionary learning is performed to model the microarray profiles. miTNA modules are easily extracted from the hypernetworks, and users can directly evaluate if the miRNA modules are significant. For experimental results, the hypernetwork classifier showed 91.46% accuracy for miRNA expression profiles on multiple human canters, which outperformed other machine learning methods. The hypernetwork-based analysis showed that our approach could find biologically significant miRNA modules.

CALS/EC Development Process Standardization Progress Direction (CALS/EC 개발 프로세스 표준화 발전방향)

  • 최헌준;이윤희
    • Proceedings of the CALSEC Conference
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    • 1998.10a
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    • pp.149-161
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    • 1998
  • For the purpose of developing CALS/EC, it was surveyed ISO/IEC 12207 that was international standard and IEEE/EIA 12207 that was national standard in U.S.A and then peformed analysis comparing with MIL-STD-498 it was called origin of DoD software development process. Also it was surveyed software life cycle Process using doemstic defense area now Software life cycle process based on MIL-STD-498 in defense area was not yet includ the concept of new development philosophy like iterative development and process management according to the characteristics of project. For the purpose of improving software life cycle in defense area, first refined the process. And then on this study it was recommended accomodation of incremental and evolutionary development approach and the method of tailoring based on MIL-STD-498 was able to select and apply the process on the characteristics of project.

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Evolution of Behavioral Logic of Artificial Individuals Using Cell-level Evolution Framework (셀 수준의 진화 프레임워크를 통한 인공개체의 행동로직 진화)

  • Jung, Bo-Sun;Jung, Sung Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.1
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    • pp.22-28
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    • 2015
  • In this paper, we studied the evolution of behavioral logic of artificial individuals using cell-level evolution framework. We first implemented cell-level evolution framework and then investigated the evolution of behavioral logic that artificial individuals ate foods on the framework. A logic frame for behavioral decisions of artificial individuals was devised and applied to the framework. From extensive tests, we found that most artificial individuals could evolve the behavioral logic that they could eat food in a short generation. It was also confirmed that most behavioral logics showed nearly same behaviors of artificial individuals in most tests. Our method has the differences from existing algorithms using evolutionary algorithms and evolvable hardwares in that it is a basically different approach. These results showed that our framework could be a good tool for investigating the evolution of artificial individuals in a cell-level.

An Innate Bactericidal Oleic Acid Effective Against Skin Infection of Methicillin-Resistant Staphylococcus aureus: A Therapy Concordant with Evolutionary Medicine

  • Chen, Chao-Hsuan;Wang, Yanhan;Nakatsuji, Teruaki;Liu, Yu-Tsueng;Zouboulis, Christos C.;Gallo, Richard L.;Zhang, Liangfang;Hsieh, Ming-Fa;Huang, Chun-Ming
    • Journal of Microbiology and Biotechnology
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    • v.21 no.4
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    • pp.391-399
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    • 2011
  • Free fatty acids (FFAs) are known to have bacteriocidal activity and are important components of the innate immune system. Many FFAs are naturally present in human and animal skin, breast milk, and in the bloodstream. Here, the therapeutic potential of FFAs against methicillin-resistant Staphylococcus aureus (MRSA) is demonstrated in cultures and in mice. Among a series of FFAs, only oleic acid (OA) (C18:1, cis-9) can effectively eliminate Staphylococcus aureus (S. aureus) through cell wall disruption. Lauric acid (LA, C12:0) and palmitic acid (PA, C16:0) do not have this ability. OA can inhibit growth of a number of Gram-positive bacteria, including hospital and community-associated MRSA at a dose that did not show any toxicity to human sebocytes. The bacteriocidal activities of FFAs were also demonstrated in vivo through injection of OA into mouse skin lesions previously infected with a strain of MRSA. In conclusion, our results suggest a promising therapeutic approach against MRSA through boosting the bacteriocidal activities of native FFAs, which may have been co-evolved during the interactions between microbes and their hosts.

An evolutionary fuzzy modelling approach and comparison of different methods for shear strength prediction of high-strength concrete beams without stirrups

  • Mohammadhassani, Mohammad;Nezamabadi-pour, Hossein;Suhatril, Meldi;shariati, Mahdi
    • Smart Structures and Systems
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    • v.14 no.5
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    • pp.785-809
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    • 2014
  • In this paper, an Adaptive nerou-based inference system (ANFIS) is being used for the prediction of shear strength of high strength concrete (HSC) beams without stirrups. The input parameters comprise of tensile reinforcement ratio, concrete compressive strength and shear span to depth ratio. Additionally, 122 experimental datasets were extracted from the literature review on the HSC beams with some comparable cross sectional dimensions and loading conditions. A comparative analysis has been carried out on the predicted shear strength of HSC beams without stirrups via the ANFIS method with those from the CEB-FIP Model Code (1990), AASHTO LRFD 1994 and CSA A23.3 - 94 codes of design. The shear strength prediction with ANFIS is discovered to be superior to CEB-FIP Model Code (1990), AASHTO LRFD 1994 and CSA A23.3 - 94. The predictions obtained from the ANFIS are harmonious with the test results not accounting for the shear span to depth ratio, tensile reinforcement ratio and concrete compressive strength; the data of the average, variance, correlation coefficient and coefficient of variation (CV) of the ratio between the shear strength predicted using the ANFIS method and the real shear strength are 0.995, 0.014, 0.969 and 11.97%, respectively. Taking a look at the CV index, the shear strength prediction shows better in nonlinear iterations such as the ANFIS for shear strength prediction of HSC beams without stirrups.

Comparative Genomics Reveals the Core and Accessory Genomes of Streptomyces Species

  • Kim, Ji-Nu;Kim, Yeonbum;Jeong, Yujin;Roe, Jung-Hye;Kim, Byung-Gee;Cho, Byung-Kwan
    • Journal of Microbiology and Biotechnology
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    • v.25 no.10
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    • pp.1599-1605
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    • 2015
  • The development of rapid and efficient genome sequencing methods has enabled us to study the evolutionary background of bacterial genetic information. Here, we present comparative genomic analysis of 17 Streptomyces species, for which the genome has been completely sequenced, using the pan-genome approach. The analysis revealed that 34,592 ortholog clusters constituted the pan-genome of these Streptomyces species, including 2,018 in the core genome, 11,743 in the dispensable genome, and 20,831 in the unique genome. The core genome was converged to a smaller number of genes than reported previously, with 3,096 gene families. Functional enrichment analysis showed that genes involved in transcription were most abundant in the Streptomyces pan-genome. Finally, we investigated core genes for the sigma factors, mycothiol biosynthesis pathway, and secondary metabolism pathways; our data showed that many genes involved in stress response and morphological differentiation were commonly expressed in Streptomyces species. Elucidation of the core genome offers a basis for understanding the functional evolution of Streptomyces species and provides insights into target selection for the construction of industrial strains.

Five New Wood Decay Fungi (Polyporales and Hymenochaetales) in Korea

  • Kim, Nam Kyu;Park, Jae Young;Park, Myung Soo;Lee, Hyun;Cho, Hae Jin;Eimes, John A.;Kim, Changmu;Lim, Young Woon
    • Mycobiology
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    • v.44 no.3
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    • pp.146-154
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    • 2016
  • The wood decay fungi are a diverse taxonomic group that plays a pivotal role in forest carbon cycling. Wood decay fungi use various enzymatic pathways to digest dead or living wood in order to obtain carbon and other nutrients and these enzymatic systems have been exploited for both industrial and medical applications. Over 600 wood decay fungi species have been described in Korea; however, the recent application of molecular markers has dramatically altered the taxonomy of many of these wood decay fungi at both the genus and species levels. By combining molecular methods, specifically sequences of the internal transcribed spacer region, with traditional morphological characters, this study identified five new species records for Korea in five genera: Aurantiporus, Favolus, Neofavolus, Loweomyces, and Hymenochaetopsis. Three of these genera (Aurantiporus, Favolus, and Loweomyces) were previously unknown in Korea. The relatively simple morphology of the wood decay fungi often leads to ambiguous taxonomic assignment. Therefore, molecular markers are a necessary component of any taxonomic or evolutionary study of wood decay fungi. Our study highlights the need for a more robust and multifaceted approach in investigating new wood decay fungi in Korea.

Aggression and Neurotransmitters (공격성과 신경전달물질)

  • Yu, Si Young;Choi, Yejee;Kim, Sangjoon;Jeong, Hyeonseok S.;Ma, Jiyoung;Kim, Young Hoon;Moon, Sohyeon;Kang, Ilhyang;Jeong, Eujin;Suh, Chae Won;Shin, Kyung-Shik;Kim, Jieun E.
    • Korean Journal of Biological Psychiatry
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    • v.23 no.3
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    • pp.108-115
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    • 2016
  • Aggression and aggressive behaviors, often explained as harmful social interaction with the intention of hurting or inflicting damage upon another, have been considered as an adaptive mechanism from the evolutionary psychological point of view. However, various studies on aggression and aggressive behaviors have been done with psychopathological approach as the extreme aggressive behaviors may harm themselves and others at the same time. Recently, researchers have attempted to explain aggression in terms of neurobiological substrates rather than based on traditional psychopathological and/or behavioral concept. In this regard, there have been findings of differences in neurotransmitters and their receptors, and genetic polymorphisms. In this review article, we provide a brief overview of the literature about seven most frequently reported neurotransmitters including neurohormones (serotonin, norepinephrine, dopamine, gamma-aminobutyric acid, nitric oxide, oxytocin and vasopressin) and an associated enzyme (monoamine oxidase A), which are known to be related with aggression and aggressive behaviors.