• Title/Summary/Keyword: micro-history

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Veriation of Pore Structure of High Strength Concrete Including Silica Fume Exposed to High Temperature (고온에 노출된 실리카퓸 혼입 고강도 콘크리트의 공극구조 변화)

  • Song Hun;Soh Yang-Seob
    • Journal of the Korea Concrete Institute
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    • v.16 no.5 s.83
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    • pp.597-604
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    • 2004
  • This work involves quantitatively investigating the correlation between reductions in strength and variations in pore structure under high temperature that can be utilized as estimation for predicting the inner temperature of member damaged by fire. The experimental results were remarkedly affected by micro-filling effect of silica fume and the different water-binder ratios. The increase of the exposure temperature caused the increase of porosity, which resulted from the reason that evaporable water in gel pore or capillary pores as well as chemically bound water was eliminated from hardened cement paste due to the dehydration of C-S-H and $Ca(OH)_2$. Thermal shrinkage of hardened cement paste gives rise to micro-crack, which cause the increase of porosity. Based on the experimental result that the increase of porosity is in charge of exposure temperature, how porosity is distributed can predict temperature-time history and assess the performance of concrete damaged by fire.

Development of Multi-Body Dynamics Simulator for Bio-Mimetic Motion in Lizard Robot Design (도마뱀 로봇 설계를 위한 생체운동 모사 다물체 동역학 시뮬레이터 개발)

  • Park, Yong-Ik;Seo, Bong Cheol;Kim, Sung-Soo;Shin, Hocheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.6
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    • pp.585-592
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    • 2014
  • In this study, a multibody simulator was developed to analyze the bio-mimetic motion of a lizard robot design. A RecurDyn multibody dynamics model of a lizard was created using a micro-computerized tomography scan and motion capture data. The bio-mimetic motion simulator consisted of a trajectory generator, an inverse kinematics module, and an inverse dynamics module, which were used for various walking motion analyses of the developed lizard model. The trajectory generation module produces spinal movements and gait trajectories based on the lizard's speed. Using the joint angle history from an inverse kinematic analysis, an inverse dynamic analysis can be carried out, and the required joint torques can be obtained for the lizard robot design. In order to investigate the effectiveness of the developed simulator, the required joint torques of the model were calculated using the simulator.

Associations Between Three Common MicroRNA Polymorphisms and Hepatocellular Carcinoma Risk in Chinese

  • Hao, Yu-Xia;Wang, Jun-Ping;Zhao, Long-Feng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6601-6604
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    • 2013
  • Aim: Associations between polymorphisms in miR-146aG>C, miR-196a2C>T and miR-499A>G and risk of HCC, and interaction with HBV infection in a Chinese population, were the target of the present research. Methods: The duplex polymerase-chain-reaction with confronting-two-pair primers (PCR-RFLP) was performed to determine the genotypes of the miR-146aG>C, miR-196a2C>T and miR-499A>G genotypes. Associations of polymorphisms with the risk of HCC were estimated by conditional logistic regression analysis. Results: Drinking, family history of cancer, HBsAg and HCV were risk factors for HCC. Multivariate regression analyses showed that subjects carrying the miR-196a2 CC genotype had significantly increased risk of HCC, with an adjusted OR (95% CI) of 2.18 (1.23-3.80). In addition, cases carrying the miR-196a2 C allele had a 1.64-fold increase in the risk for HCC (95%CI=1.03-2.49). The miR-196a2 CT and TT genotypes greatly significantly increased the risk of HCC in subjects with HBV infection, with adjusted ORs (95% CI) of 2.02 (1.12-3.68) and 2.69 (1.28-5.71), respectively. Conclusion: Our results demonstrate that miR-196a2 CC genotype and C allele have an important role in HCC risk in Chinese, especially in patients with HBV infection.

The optimum damping retrofit for cabinet structures of NPP by μ-GA (μ-GA를 이용한 원전 캐비닛구조물의 최적감쇠보강)

  • Lee, Gye-Hee;Ha, Dong-Ho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.1 s.41
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    • pp.1-7
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    • 2005
  • The optimal seismic retrofitting of NPP(Nuclear Power Plant) cabinet structures that contain seismic category 1 relays was studied in this paper. During earthquake event, the failure modes of relays are not appeared in form of structural failure, but are appeared in form of contact chatter of relay. Therefore, the retrofitting of cabinet has to be aimed at the reducing of the structural response, such as acceleration. In this study, the optimal characteristic values of dampers were searched by ${\mu}$-GA (micro-Genetic Algorithm) scheme for several installation patterns. To keep accuracy and efficiency of analysis, the structural models of cabinet were considered as a frame structure. The responses of structure were obtained inform of acceleration response spectra derived from the results of nonlinear time history analysis including damping nonlinearity. The objective function of the optimum procedure was constructed based on the maximum ratio of maximum spectral value and target GERS (General Equipment Ruggedness Spectra). The results show the good improvements of fitness for adequate retrofitting pattern. Especially, the improvements of fitness were remarkable when the values of damping exponents are low.

Implications of Five Laws of Library Science on Dr. S. R. Ranganathan's Colon Classification: An Explorative Study

  • Kumar, S.K. Asok;Babu, B. Ramesh;Rao, P. Nageswara
    • Journal of the Korean Society for Library and Information Science
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    • v.45 no.4
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    • pp.309-326
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    • 2011
  • There have been several milestones in the history of library classification but most of the schemes failed to meet the new challenges in the organisation of information. Dr. S. R. Ranganathan tried to revolutionise the whole thinking on classificatory approach, when he devised the Colon Classification (CC) in 1933. He developed the Colon Classification scheme with a sound theoretical background based on normative principles, Five laws of Library science, canons, etc. One important feature of CC is that, its use is not confined to information storage and retrieval alone. This paper presents an over view of different editions of the CC highlighting the salient features of the editions. Further the implication of Five Laws of Library Science has been described. The authors stressed that the features of such as greater hospitality, specificity and mixed notation has paved the way to design and develop the depth schedules on various micro level subjects and so far about 130 micro schedules have been published. The impressions by the leading LIS professionals during and after Ranganathan's time have been highlighted. The authors expressed the fear that when the library world would see the complete version of the seventh edition of CC? It may be due to lack of institutional support engaging in the research or financial constraints. The authors are of the opinion that any scheme to flourish needs a sound research body to bring out the revised editions as done in the case of Dewey Decimal Classification. The relevance of the CC in the contemporary world of Librarianship is discussed. Finally concludes that CC needs to be resuscitated as it is a precious national heritage; and still a force for the management of libraries.

An innovative BRB with viscoelastic layers: performance evaluation and numerical simulation

  • Zhou, Ying;Gong, Shunming;Hu, Qing;Wu, Rili
    • Structural Monitoring and Maintenance
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    • v.5 no.2
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    • pp.205-229
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    • 2018
  • Energy induced by minor earthquake and micro vibration cannot be dissipated by traditional buckling-restrained braces (BRBs). To solve this problem, a new type of hybrid passive control device, named as VE-BRB, which is configured by a BRB with high-damping viscoelastic (VE) layers, is developed and studied. Theoretical analysis, performance tests, numerical simulation and case analysis are conducted to study the seismic behavior of VE-BRBs. The results indicate that the combination of hysteretic and damping devices lead to a multi-phased nature and good performance. VE-BRB's working state can be divided into three phases: before yielding of the steel core, VE layers provide sufficient damping ratio to mitigate minor vibrations; after yielding of the steel core, the steel's hysteretic deformations provide supplemental dissipative capacity for structures; after rupture of the steel core, VE layers are still able to work normally and provide multiple security assurance for structures. The simulation results agreed well with the experimental results, validating the finite element analysis method, constitutive models and the identified parameters. The comparison of the time history analysis on a 6-story frame with VE-BRBs and BRBs verified the advantages of VE-BRB for seismic protection of structures compared with traditional BRB. In general, VE-BRB had the potential to provide better control effect on structural displacement and shear in all stages than BRB as expected.

A Study on the Exteriority of Interior in the Louis I. Kahn's Architecture - Focused on the Study of Character of Connecting Elements - (루이스 칸 건축의 외부화된 내부에 관한 연구 - 연결공간의 체험과 표현을 중심으로 -)

  • Woo, Young-Sun;Shin, Buhm-Shik
    • Journal of architectural history
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    • v.14 no.4 s.44
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    • pp.117-135
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    • 2005
  • This paper is a study of the possibility of experience and expression in the architecture of Louis I. Kahn by focusing on the characters of entrance, court and window/wall of his public buildings. In the course of composition, Kahn defined the entrance, court and window/wall as an connecting elements and elements of boundary. The characters revealed by these elements or rooms give the clue to insight Kahn's thought of relation of interior and exterior space or inner and outer space. Following are the characters of these elements. First, a entrance reveals the fact that inner space separates from outer space by connecting these two space and giving the value to inner space as the entity and totality like outer space. The entrance gives its ontological being to human subjects not by vision but experience and expression which is the essence of commonness, that is, Silence. Kahn made the possibility of activity amplify in this common and silent space. Second, this entrance is connected with wide and huge central space not individual spaces of interior space. This extreme procedure of entering makes human subject feel sublime of intoner space. And the central spaces becomes another exterior or another world in the inner world of architecture by the lights from above and by having the boundary wall which shows same pattern of exterior wall. Third, Kahn regarded a window as the giver of lights not as the medium of vision connecting inner space with outer. He tried to connect interior with exterior through the being and character of the light expressed in the interior. And in his buildings, interior space is connected with exterior by expressing the purpose of building, composition of inner space, structural truth and construction facts through the Form, a pattern of wall, details and ornamental joints. By practicing this thoughts in the real buildings, Kahn tried to gave aura to both the interior space and entity of architecture which is regarded as micro universe like flowers, rocks and human beings.

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Places of Memory in the Collective Memory of Locals in Janghang, Korea

  • Park, Jae-min;Kim, Moohan
    • Journal of recreation and landscape
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    • v.12 no.4
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    • pp.45-58
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    • 2018
  • Place memory is a new way of seeing as a new concept of cultural landscape research. Various research works and discussions have recently spread in landscape studies. In particular, the, which is visible and material, is a medium in which collective memory is embedded in place memory. The purpose of this study is to extract places of memory from the collective memory of residents of Janghang, Korea, and to visualize it through semantic relations. For this purpose, semi-standardized interviews (34 persons) were conducted with residents, and frequency analysis and semantic network analysis were used. As a result, the interviewees recalled only 127 places in Janghang that existed between 1920 and 2010. Locals remember the city based on places of memory. This means that the city could be illustrated according to specific places that are frequently mentioned. For instance, the top 25 places (top 20%) explain 65.6% of all the places in the city, and the top 39 places (top 30.8%) could describe 78.7% of the places. Some places are referred to more frequently when they are in the city's symbolic landscape, and the city's identity is projected on them. Some places were mentioned only infrequently but were nevertheless very important places by which to understand Janghang. These places of memory have not appeared in the documentary records before, which shows the value of the collective memory of the locals and the effectiveness of the interviewing method. In the clustering of the semantic network, six groups of places appeared. The local residents remembered the modern industrial city and recalled it in connection with the sites of daily life. This shows the possibility of looking not only at public memory and famous heritage as a macro history but also at daily life and meaningful places as a micro history about locals. This study has significance as an initial research that identified and visualized places of memory from the perspective of local residents. Such an approach could be useful in the study of everyday life and the conservation of modern heritage.

A Study on the Therapeutic Usage of Natural Pigments in the Joseon Period (조선시대에 사용된 천연염료의 한의학적 활용 가능성 고찰)

  • Yoon Eunkyung;Lee Sangbin;Baik Yousang;Kim Jong-hyun;Ahn Jinhee
    • Journal of Korean Medical classics
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    • v.37 no.2
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    • pp.77-99
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    • 2024
  • Objectives : This study examined the possibility of therapeutic application of natural pigments in the Joseon Period other than aesthetic purposes. Methods : The medicinal properties of natural pigments as written in the texts Sangayorok, Gyuhapchongseo, Imwongyeongjeji were searched and analyzed in the texts Bencaogangmu, Encyclopedia of Eastern Medicine, and the Encyclopedia of Chinese Medicinals focusing on their Qi, flavor, effects and application. Of the conditions they treated, we examined whether they treated skin conditions using external application. The Korean Medical effects of these pigments were examined based on the content of the skin chapter of the Donguibogam. Results : We were able to extract 47 kinds of natural pigments, most of which had cold nature and bitter tasting properties. In addition, most of the pigments had the effect of treating skin conditions, illnesses due to micro-organisms, and of detoxifying. Conclusions : After consideration of medicinal properties and effects of the herbs that were used as pigments in the Joseon period, it could be concluded that as these herbs not only function as pigments but also hold properties that prevent skin conditions, their therapeutic functions could have been considered when using them as pigments.

Association Between MicroRNA196a2 rs11614913 Genotypes and the Risk of Non-Small Cell Lung Cancer in Korean Population

  • Hong, Young-Seoub;Kang, Ho-Jin;Kwak, Jong-Young;Park, Byung-Lae;You, Chang-Hun;Kim, Yu-Mi;Kim, Heon
    • Journal of Preventive Medicine and Public Health
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    • v.44 no.3
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    • pp.125-130
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    • 2011
  • Objectives: The microRNA (miRNA) miR-196a2 may play an important role in lung cancer development and survival by altering binding activity of target mRNA. In this study, we evaluated their associations with the susceptibility of non-small cell lung cancers (NSCLC) by case-control study in a Korean population. Methods: We performed genotyping analyses for miR-196a2 rs11614913 T/C at miRNA regions in a case-control study using blood samples of 406 NSCLC patient and 428 cancer-free control groups. Results: The total C allele frequencies for miR-196a2 were 48.8% for the patients and 45.6% for the controls; and the genotype frequencies of TT, TC, and CC were 23.7%, 55.2%, and 21.1% for the patients and 31.1%, 46.35%, and 22.4% for the controls (p<0.05). Participants who possesses TC/CC genotypes showed high risk for NSCLC compared to those possessed TT genotypes (OR, 1.42; 95% CI, 1.03 to 1.96). The association was persisted in 60 and older age group, male, smokers, those without family history for cancer. However, no significant association of CC genotypes in recessive genetic model was observed. Conclusions: In conclusion, this case-control study provides evidence that miR-196a2 rs11614913 C/T polymorphisms are associated with a significantly increased risk of NSCLC in a dominant model, indicating that common genetic polymorphisms in miR-196a2 rs11614913 are associated with NSCLC. The association of miR196a2 rs11614913 polymorphisms and NSCLC risk require confirmation through additional larger studies.