• Title/Summary/Keyword: network activity

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Determinants of Firms' Standardization Activity: Evidence from the Korean Service Firms (기업의 표준화활동 결정요인 : 우리나라 서비스기업에 대한 실증연구)

  • Sung, Tae-Kyung
    • Management & Information Systems Review
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    • v.28 no.2
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    • pp.95-112
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    • 2009
  • The paper investigates the determinants of firm's standardization activity in the Korean service industry. Standardization variables as dependent ones are standardization management at the firm level, domestic standardization activity, and international standardization activity. The independent variables include innovative activities(R&D intensity and patent application), firm size, export ratio, network, and firm's organization characteristics. We estimated the logistic regression model, using the data from 102 Korean service firms. The empirical findings are as follows. First, R&D intensity has a positive effect on international standardization activity, but not on the standardization management at the firm level and domestic standardization activity. Second, patent application has a negative effect on the standardization management at the firm level. Third, firm size doesn't have any influence on firms' standardization activities in the service sector. Fourth, the level of chief executive officer's interest on standardization is a very important factor in determining firms' efforts to participate standardization process, regardless of types of standardization activity.

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Robust 2D human upper-body pose estimation with fully convolutional network

  • Lee, Seunghee;Koo, Jungmo;Kim, Jinki;Myung, Hyun
    • Advances in robotics research
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    • v.2 no.2
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    • pp.129-140
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    • 2018
  • With the increasing demand for the development of human pose estimation, such as human-computer interaction and human activity recognition, there have been numerous approaches to detect the 2D poses of people in images more efficiently. Despite many years of human pose estimation research, the estimation of human poses with images remains difficult to produce satisfactory results. In this study, we propose a robust 2D human body pose estimation method using an RGB camera sensor. Our pose estimation method is efficient and cost-effective since the use of RGB camera sensor is economically beneficial compared to more commonly used high-priced sensors. For the estimation of upper-body joint positions, semantic segmentation with a fully convolutional network was exploited. From acquired RGB images, joint heatmaps accurately estimate the coordinates of the location of each joint. The network architecture was designed to learn and detect the locations of joints via the sequential prediction processing method. Our proposed method was tested and validated for efficient estimation of the human upper-body pose. The obtained results reveal the potential of a simple RGB camera sensor for human pose estimation applications.

v-Crk Induces Rac-dependent Membrane Ruffling and Cell Migration in CAS-deficient Embryonic Fibroblasts

  • Sung, Bong Hwan;Yeo, Myoung Gu;Oh, Hye Jin;Song, Woo Keun
    • Molecules and Cells
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    • v.25 no.1
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    • pp.131-137
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    • 2008
  • Crk-associated substrate (CAS) is a focal adhesion protein that is involved in integrin signaling and cell migration. CAS deficiency reduces the migration and spreading of cells, both of which are processes mediated by Rac activation. We examined the functions of v-Crk, the oncogene product of the CT10 virus p47gag-crk, which affects cell migration and spreading, membrane ruffling, and Rac activation in CAS-deficient mouse embryonic fibroblasts (CAS-/- MEFs). CAS-/- MEFs showed less spreading than did CAS+/+ MEFs, but spreading was recovered in mutant cells that expressed v-Crk (CAS-/-v-Crk MEF). We observed that the reduction in spreading was linked to the formation of membrane ruffles, which were accompanied by Rac activation. In CAS-/- MEFs, Rac activity was significantly reduced, and Rac was not localized to the membrane. In contrast, Rac was active and localized to the membrane in CAS-/-v-Crk MEFs. Lamellipodia protrusion and ruffle retraction velocities were both reduced in CAS-/- MEFs, but not in CAS-/-v-Crk MEFs. We also found that microinjection of anti-gag antibodies inhibited the migration of CAS-/-v-Crk MEFs. These findings indicate that v-Crk controls cell migration and membrane dynamics by activating Rac in CAS-deficient MEFs.

Methionine Analogue Probes Functionally Important Residues in Active Site of Methionyl-tRNA Synthetase

  • Jo, Yeong-Joon;Lee, Sang-Won;Jo, Myung-Kyun;Lee, Jee-Woo;Kang, Mee-Kyoung;Yoon, Jeong-Hyeok;Kim, Sung-Hoon
    • BMB Reports
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    • v.32 no.6
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    • pp.547-553
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    • 1999
  • Aminoacyl-tRNA synthetases are essential enzymes catalyzing the attachment of specific amino acids to cognate tRNAs. In the present work, the substrate analogue L-methionine hydroxamate was used to identify functional residues located in the active site of the E. coli methionyl-tRNA synthetase (MetRS). This compound inhibited bacteria, yeast, and human MetRS activities to a similar degree, suggesting a conserved active site structure and mechanism between MetRSs of different phylogenetic domains. Mutants of the E. coli MetRS resistant to methionine hydroxamate were also isolated. These mutants contained a substitution either at T10, Y15, or Y94. These residues are highly conserved among the different MetRSs and the mutants showed decreased aminoacylation activity, suggesting their functional and structural significances. The putative roles of these residues are discussed on a structural basis.

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Influence of R&D intensity on Innovation Performance in the Korean Pharmaceutical Industry: Focusing on the Moderating Effects of R&D Collaboration

  • Kim, Dae-Joong;Om, Kiyong
    • Knowledge Management Research
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    • v.19 no.3
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    • pp.189-223
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    • 2018
  • This paper examined the effect of innovation networks comprising research and development (R&D) collaboration on innovation performance of Korean pharmaceutical firms. As co-assigned patents and co-affiliated publications are common technical outcomes of successful R&D collaboration in the pharmaceutical industry, social network analysis technique was applied for analyzing innovation networks through patent and publication data. Results of Social network analysis indicated that a small set of highly innovative firms in the Korean pharmaceutical industry were actively involved in patenting and publishing. And the analysis of structural equation model found the followings: (1) R&D intensity significantly affected patenting, publication and new drug development, (2) the activity of patenting and publishing was positively related with the innovation performance measured by new drug development, and (3) R&D collaboration in terms of degree centrality of co-patent network played significant moderating roles on the relationships among R&D intensity, patenting, and new drug development. These findings are expected to be helpful to researchers as well as policy-makers to devise innovation-promoting policies in the Korean pharmaceutical industry. Discussions and limitations of the study are provided in the last part.

The Role of Nitric Oxide in Mycobacterial Infections

  • Yang, Chul-Su;Yuk, Jae-Min;Jo, Eun-Kyeong
    • IMMUNE NETWORK
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    • v.9 no.2
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    • pp.46-52
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    • 2009
  • Although tuberculosis poses a significant health threat to the global population, it is a challenge to develop new and effective therapeutic strategies. Nitric oxide (NO) and inducible NO synthase (iNOS) are important in innate immune responses to various intracellular bacterial infections, including mycobacterial infections. It is generally recognized that reactive nitrogen intermediates play an effective role in host defense mechanisms against tuberculosis. In a murine model of tuberculosis, NO plays a crucial role in antimycobacterial activity; however, it is controversial whether NO is critically involved in host defense against Mycobacterium tuberculosis in humans. Here, we review the roles of NO in host defense against murine and human tuberculosis. We also discuss the specific roles of NO in the central nervous system and lung epithelial cells during mycobacterial infection. A greater understanding of these defense mechanisms in human tuberculosis will aid in the development of new strategies for the treatment of disease.

Wireless Intrusion Prevention System based on Snort Wireless (Snort Wireless 기반의 무선 침입 방지 시스템)

  • Kim, A-Yong;Jeong, Dae-Jin;Park, Man-Seub;Kim, Jong-Moon;Jung, Hoe-Kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.666-668
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    • 2013
  • Wireless network environment is spreading due to the increase of using mobile devices, causing wireless network abuse. Network security and intrusion detection have been paid attention to wireless as well as wired existing and studied actively Snort-based intrusion detection system (Intrusion Detection System) is a proven open source system which is widely used for the detection of malicious activity in the existing wired network. Snort Wireless has been developed in order to enable the 802.11 wireless detection feature. In this paper, Snort Wireless Rule is analyzed. Based on the results of the analysis, present the traveling direction of future research.

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User Influence Discrimination Scheme Using Activity Analysis in Social Networks (소셜 네트워크에서 행위 분석을 통한 사용자 영향력 판별 기법)

  • Park, Yunjeong;Lee, Seohee;Han, Jinsu;Noh, Yeonwoo;Lim, Jongtae;Kim, Yeonwoo;Bok, Kyongsoo;Yoo, Jaesoo
    • The Journal of the Korea Contents Association
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    • v.16 no.12
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    • pp.551-561
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    • 2016
  • A user influence discrimination scheme using big data from social networks is needed. In this thesis, we propose a user influence discrimination scheme considering reliability in social networks. The proposed scheme measures reliability scores through social activities and simplifies a social network by collecting only reliable users. It also derives user influence by considering direct and indirect influences that depends on network degree between users. As a result, the proposed scheme improves the expandability of the user influence. In order to show the superiority of the proposed scheme, we compare it with the existing scheme through performance evaluations in terms of reliability and user influence.

Computational electroencephalography analysis for characterizing brain networks

  • Sunwoo, Jun-Sang;Cha, Kwang Su;Jung, Ki-Young
    • Annals of Clinical Neurophysiology
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    • v.22 no.2
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    • pp.82-91
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    • 2020
  • Electroencephalography (EEG) produces time-series data of neural oscillations in the brain, and is one of the most commonly used methods for investigating both normal brain functions and brain disorders. Quantitative EEG analysis enables identification of frequencies and brain activity that are activated or impaired. With studies on the structural and functional networks of the brain, the concept of the brain as a complex network has been fundamental to understand normal brain functions and the pathophysiology of various neurological disorders. Functional connectivity is a measure of neural synchrony in the brain network that refers to the statistical interdependency between neural oscillations over time. In this review, we first discuss the basic methods of EEG analysis, including preprocessing, spectral analysis, and functional-connectivity and graph-theory measures. We then review previous EEG studies of brain network characterization in several neurological disorders, including epilepsy, Alzheimer's disease, dementia with Lewy bodies, and idiopathic rapid eye movement sleep behavior disorder. Identifying the EEG-based network characteristics might improve the understanding of disease processes and aid the development of novel therapeutic approaches for various neurological disorders.

Semantic Network Analysis of Physiotherapy Research: Based on Studies Published in the Journal of IAPTR

  • Go, Junhyeok;Yeum, Dongmoon;Kim, Nyeonjun;Choi, Myungil
    • Journal of International Academy of Physical Therapy Research
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    • v.10 no.4
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    • pp.1926-1933
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    • 2019
  • Background: Physical therapy has been widely studied in various fields, however, the academic trends and characteristics has not been systematically analyzed. Semantic network analysis is used as an approach for this study. Objective: To explore academic trends and knowledge system in the physiotherapy research in the Journal of International Academy Physical Therapy (J of IAPTR) Study design : Literature review Method: Semantic network analysis was conducted using the titles of 272 articles published in the Journal of IAPTR from 2010 to 2019. Results: Frequency analysis revealed following most frequently used key words; Stroke (27 times), Balance (21 times), Elder (13 times), Forward head posture (FHP, 11 times), Muscle activity (9 times). The relationship between the presented keywords is divided into six subgroups (FHP and pain, walk and quality, elder and balance, stroke and apoptosis, muscle strength and function) according to their correlation and frequency to be used together. Conclusion: The study is considered to be of help to researchers who want to identify research trends in physiotherapy.