• Title/Summary/Keyword: critical means

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Membrane fouling reduction using electro-coagulation aided membrane bio-reactor (전기응집 분리 막 생물반응기의 막 오염 저감)

  • Kim, Wan-Kyu;Hong, Sung-Jun;Chang, In-Soung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.8
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    • pp.105-114
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    • 2018
  • Membrane fouling in EC-MBR (Electro-Coagulation aided Membrane Bio-Reactor) processes was evaluated according to the operating parameters, such as current density and contact time. In addition, the fouling mechanism was investigated. Compared to the control (i.e., no electro-coagulation), membrane fouling for filtration of the activated sludge suspension after electro-coagulation was reduced significantly. Membrane fouling was improved further when the contact time was doubled under a low current density of $2.5A/m^2$. On the other hand, membrane fouling was not mitigated further, as expected, even though the contact time was doubled from 12 to 24 hr. at a current density of $10A/m^2$. This indicates that the overall decrease in membrane fouling is a function of the product of the current density and contact time. The particle size of the activated sludge flocs after electro-coagulation was changed slightly, which means that the membrane fouling reduction was not attributed to a larger particle size resulting from electro-coagulation. The experimental confirmed that the dynamic membrane made from aluminum hydroxide, Al(OH)3, and/or aluminum phosphate, Al(PO4), which had been formed during the electro-coagulation, played a key role on the reduction of membrane fouling. The dynamic membrane prevents the particles in the feed solution from deposition to the membrane pores and cake layers. Dynamic membrane formation as a result of electro-coagulation plays a critical role in the mitigation of membrane fouling in EC-MBR.

A study on conceptual evaluation of structural stability of room-and-pillar underground space (주방식 지하공간의 구조적 안정성 평가개념 정립에 관한 연구)

  • Lee, Chulho;Chang, Soo-Ho;Shin, Hyu-Soung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.6
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    • pp.585-597
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    • 2013
  • In this study, in order to evaluate stability of the room-and-pillar underground structure, a series of preliminary numerical analyses were performed. Design concept and procedure of an underground structure for obtaining a space are proposed, which should be different from structural design for the room-and-pillar in mine. With assumed material properties, a series of numerical analyses were performed by varying size ratios of room and pillar and then the failure modes and location at yielding initiation were investigated. From the results, relationship between the ratio of pillar width to the roof span (w/s) and overburden pressure at failure initiation shows a relatively linear relation, and the effect of w/s on structural stability is much more critical than the ratio of pillar width and height (w/H) which is a crucial parameter in design of the room-and-pillar mining. It means that roof tensile failure and shear failure at shoulder and pillar are necessary to be considered together for confirming overall structural stability of the room-and-pillar structure, rather than considering the pillar stability only in mining. Failure modes and location at failure initiation were varied with respect to the ratio of room and pillar widths. Therefore, it is necessary to simultaneously consider stability of both roof span and pillar for design of underground structure by the room-and-pillar method.

A Study on the Effects of the Manufacturer's Market Orientation on Quality Management activity and Business Performance (제조기업의 시장지향성이 품질경영활동과 경영성과에 미치는 영향에 관한 연구)

  • Won, Yu-Young;Park, Jong-Woo;Song, Gwang-Suk;Shin, Ho-Chul
    • Journal of Distribution Science
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    • v.11 no.6
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    • pp.81-89
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    • 2013
  • Purpose - The market orientation of a manufacturer is a very critical competitive advantage factor in the development of new markets and the sustainability and maintenance of existing ones, achieved through the design of customer-oriented products. This is recognized as a virtuous circle, in which firms grow by means of promoting quality management. However, though market-oriented activities are important in management and operations, they seem to be promoted mainly by large-scale enterprises rather than by small- and medium-scale firms, the latter having invested relatively few company resources. Furthermore, few studies and analyses have examined how market orientation relates to the expansion of quality programs within organizations or with business performance; the market orientation and customer-orientation concepts are mixed together when both are used in research. Given the current market situation in which the servitization of manufacturing firms is rapidly expanding, this study's analysis of the effect on market orientation of manufacturers is a significant contribution. From this perspective, this study has several objectives. First, is to analyze and suggest the relationship between market orientation and quality management activity for manufacturers, focusing on three sub-activities: products, process, and quality management activities. Second, it is intended to identify correlation between manufacturers' market oriented activity and their management performance and then to analyze how market orientation affects business performance. The results of a number of prior studies on the correlation between market orientation and management performance have indicated that market orientation does affect management performance. Third, this study also investigates whether any differences in the relationship among market orientation, quality management activity and business performance occur according to company size. The results are used to present operational suggestions for large- and small- and medium-size firms. Research design, data, methodology - This study seeks to analyze and identify the causal features of the organic relationship among market orientation, quality management, and management performance for Korean manufacturing companies using three years (2005-2007) of market orientation, quality management, and business performance data. Subsequently, structural equation modeling was used to analyze the causal features of related factors and it aims to identify the features of market orientation, quality management, and business performance. Results - The analysis examined how market orientation affected the quality management and management performance of 159 smalland medium-size companies. In particular, enterprise quality management was analyzed in relation to management performance with a focus on activities such as leadership, measurement and improvement, quality control, cost management, and process management. Conclusions - The result of the analysis show that market orientation significantly affected all of the quality management activities and that market orientation in turn significantly affected organizational performance. The result of analysis indicate that quality management activities have a significant effect on quality control and cost management.

Effect of Image, Trust and Responsiveness of Social Welfare Organizations on Continuing Sponsorship of Private Donors: Focusing on Mediation Effect of Organizational Identification and Moderation Effect of their Financial Status (사회복지조직에 대한 이미지, 신뢰성, 반응성이 개인 기부자의 후원지속성에 미치는 영향: 조직동일시의 매개효과와 경제형편의 조절효과를 중심으로)

  • Lee, Won-June
    • The Journal of the Korea Contents Association
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    • v.15 no.8
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    • pp.258-270
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    • 2015
  • The study aims at verifying the effect of the image, trust and responsiveness to social welfare organizations on continuing the sponsorship of private donors, the mediating effect of the organizational identification and the moderating effect of their financial status. As a result of causal analysis of the variables by structural equation models, regardless of donors' financial status, social welfare organizations' image, trust and responsiveness has no direct effect on continuing the sponsorship. Among the donors in relatively good financial status, social welfare organizations' image, trust and responsiveness positively have direct effects on organizational identification, which has a direct effect on continuing the sponsorship. That is, the image, trust and responsiveness influence the continuity of the sponsorship through the full mediating effect of organizational identification. On the other hand, among relatively poor donors, only the organizations' image and trust positively influence the organizational identification, The direct and indirect effects on the continuity of the sponsorship are different according to the private donors' financial status, which means that the moderating effect of the donors' financial status is proved. The result of latent mean analysis regarding 5 main latent variables according to the private donors' financial status, shows the significant difference in the continuity of sponsorship only(Mean= .197, Cohen's D=.779). By emphasizing that Organizational identification is a critical factor in terms of enhancing the continuity of sponsorship, some practical implications are discussed based on the study's findings.

Pre-hospitalization Advanced Airway Management Using The KING LTS-DTM and the LMA ProSealTM (LTS와 LMA를 이용한 병원 전 전문 기도 관리 연구)

  • Choi, Uk-Jin;Shim, Gyu-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.12
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    • pp.5893-5900
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    • 2012
  • It is very critical to promptly maintain airway of cardiac arrest cases or serious traumatic cases. The purpose of this study is to compare intubation rate, successful rate and pre-/post-education self-confidence between laryngeal tube (LTS) and proseal laryngeal mask (PLMA), so that it may contribute to improving the ability of 119 emergency team - a pivotal role in pre-hospitalization process - to carry out advanced airway management. In order to achieve the purpose, total 60 paramedics (Class I) who worked for incumbent 119 emergency team were asked to join a practical experiment and were also divided into two groups (LTS group: 30 people, PLMA group: 30 people). In details, they were all asked to take 3 sessions of practice (5 minutes per session) using dummy model to quantitatively measure the time and success/failure of intubation and the change of their self-confidence. As a result, it was found that there were statistically significant differences in the time of intubation between LTS and PLMA group (p=.000), but there was no significant difference in the rate of successful intubation between these two groups, and self-confidence of two groups tended to significantly increase after experiment (p=.000). Conclusively, if it is necessary to promptly apply intubation to traumatic cases with immobilized cervical vertebral and lingual edema, LTS can be useful as an effective means of intubation. And it is expected that continuing intubation training using LTS will improve the ability of emergency team to perform advanced airway management for traumatic cases.

Awareness of Reality and Tradition in Oh Yun's Theory of Arts during His Final Period(1984~86) - Review on the Text of "Expansion of Artistic Imagination and World" (오윤의 말기(1984~86) 예술론에서의 현실과 전통 인식 - "미술적 상상력과 세계의 확대"에 대한 텍스트 검토)

  • Park, Ca-Rey
    • The Journal of Art Theory & Practice
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    • no.6
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    • pp.101-121
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    • 2008
  • An artist, Oh Yun(1946~86)'s theory of people's art during his final period is summed up in his essay 'Expansion of Artistic Imagination and World' (1985). Emphasizing the mystic and traditional characteristics of Oh Yun's artistic oeuvre during his final period, some critics focus on Oh Yun's experience of medical treatment and shamanistic custom at Jin Do island, and his belief in Jeung San Do, the dao of Jeung-san, the Ruler of the Universe. However, they forget the practical intention and implication of his theory of art during his final period, which aimed to overcome the contradiction of revelation itself. Oh Yun's essay criticized the loss of artistic imagination and the ignorance of traditional culture that resulted from the elevation of science to a religion, and insisted that the stereotyped idealism, scientism and elitism in art should be overcome in order to recover the full reality in realism and to continue traditional cultures. The essay is comprised of 18 paragraphs. Oh Yun criticized monochromatic art, conceptual art, hyper-realistic art, objet d'art, and neo-dadaist art, saying that they were simply mechanical forms of modern art derived from scientism and a fetishistic lens culture. In addition, he criticized naturalism in art, which had continued as a tendency in the development of western art, for the same reason. He pointed out that even the world of realism had been diminished by elite stereotypes and diagrams. He declared the need to overcome the imitation of shells or stereotyped propaganda, and recover full realism, which seems to have started with a reflective examination of current problems in 'Reality and Utterance', in which he participated. Especially, he thought that universality and the extension of full realism could be achieved by building on the views of traditional cultures, which is meaningful. This logic is same as the theory of epic theatre that Bertolt Brecht(1898~1956) has developed under the ancient Greek masque and Pieter Bruegel the Elder(1525~69)'s story-like picture style. The universality of realism and the extension of acquisition to include incantation art, rather than move toward incantation art, is what Oh Yun intended to propose in 'Artistic Imagination'. This attitude is same as Bertoh Brecht's aesthetic viewpoint in the 1930s. But regrettably, Oh Yun's style wording, which seems covert and far-sighted, is often misunderstood as 'mysticism'. In the flow of people's art in the 1980s, Oh Yun was a traditionalist in a narrow sense, and an realist in a broad sense. However, his critical mind, which comprehends tradition and reality, was attempting to expand universality and extend full realism, and this attempt found many sympathizers and had an influence on the next generation of people's artists, such as "Levee" which is field-centered, to which we should pay attention. This means that while their works thought about 'tradition', we should be careful not to connect them with 'aesthetic conservatism' or 'classical art'. This is the why the meaning of Oh Yun's theory of art during his final period should be closely examined again.

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Dissolution and Duodenal Permeation Characteristics of Lovastatin from Bile Salt Solid Dispersions (담즙산염과의 고체분산체로부터 로바스타틴의 용출 및 십이지장 점막 투과 특성)

  • Chun, In-Koo
    • Journal of Pharmaceutical Investigation
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    • v.39 no.2
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    • pp.97-106
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    • 2009
  • Although lovastatin (LS) is widely used in the treatment of hypercholesterolemia, its bioavailability is known to be around 5%. This study was aimed to increase the solubility and dissolution-permeation rates of LS using solid dispersions (SDs) with bile salts. The solubilities of LS in water, aqueous bile salt solutions and non-aqueous vehicles were determined, and effects of bile salts on the cellulose or duodenal permeation of LS from SDs were evaluated using a horizontal permeation system. SDs were prepared at various ratios of LS to carriers, such as sodium deoxycholate (SDC), sodium glycocholate (SGC) and/or 2-hydroxypropyl-$\beta$-cyclodextrin (HPCD). The addition of bile salts (25 mM) in water increased markedly the solubility of LS by the micellar solubilization. Some non-aqueous vehicles were effective in solubilizing LS. From differential scanning calorimetric studies, it was found that the crystallinity of LS in SDs disappeared, indicating a formation of amorphous state. The SDs showed markedly enhanced dissolution compared with those of their physical mixtures (PMs) and drug alone. In the dissolution-permeation studies using a cellulose membrane, the donor and receptor solutions were maintained as a sink condition using pH 7.0 phosphate buffer containing 0.05% sodium lauryl sulfate (SLS). The flux of LS alone was nearly same as that of LS-SDC-HPCD (1:3:6) PM. However, the flux of LS-SDC-HPCD (1:3:6) SD slightly increased compared with drug alone and PM, suggesting that entrapment of LS in micelles does not significantly hinder the permeation across cellulose membrane. In the dissolution-duodenal permeation studies using a LS-HPCD-SDC (1:3:6) SD, the addition of various bile salts in donor solutions (25 mM) enhanced the permeation of LS markedly, and the fluxes were found to be $0.69{\pm}0.41$, $0.87{\pm}0.51$, $0.84{\pm}0.46$, $0.47{\pm}0.17$ and $0.68{\pm}0.32{\mu}g/cm^2/hr$ for sodium cholate (SC), SDC, SGC, sodium taurodeoxycholate (STDC) and sodium taurocholate (STC), respectively. The stepwise increase of donor SGC concentration increased the flux dose-dependently. From the relationship of donor SGC concentration and flux, the concentration of SGC initiating the permeation across the duodenal mucosa was calculated to be 11.1 mM, which is nearly same as the critical micelle concentration (CMC, 11.6 mM) of SGC. However, with no addition of bile salts and below CMC, the permeation was very limited and irratic, indicating that LS itself is very poor permeable. Higher protions of bile salt in SD such as LS-SDC or LS-SGC (1 : 49 and 1 : 69) showed highly promoted fluxes. In conclusion, SD systems with bile salts, which may form their micelles in intestinal fluids, might be a promising means for providing enhanced dissolution and intestinal permeation of practically insoluble and non-absorbable LS.

The Implications of Global Citizenship and Regional Identity in Multicultural Society in the Field of Geographical Education (다문화사회에서 세계시민성과 지역정체성의 지리교육적 함의)

  • Park, Seon-Heui
    • Journal of the Korean association of regional geographers
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    • v.15 no.4
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    • pp.478-493
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    • 2009
  • The purpose of this paper is to discuss the educational implications of global citizenship and regional identity in geographic education of multicultural society. Geographical education inquires into places and region on local, regional, national and global scales. Geography studies geographical representation of ethnical, cultural, political diversities of human societies. Therefore geography is a very proper subject for multicultural education. Geography has also inherent legitimacy on multicultural education in the viewpoints that space or region has valued inherent nature which is constructed by human experience, perception and response etc. Citizenship in multicultural education requests some abilities and attitudes of world citizens superior to state or nation oriented citizenship. However the education of world citizenship doesn't mean abandonment of regional identity in geographical education. Citizenship is based on geographical units which have their territories. Regional identity is the feeling of belonging as a member of a certain region, and is formed not only by race, ethnic, gender, political and social position but also by thought of nature, landscape, national identity, regional dialect, and historical context, etc. The regional identity in multicultural society means the homogeneity which includes the heterogeneity of diverse groups, and has a key which solves the conflicts of diverse groups in the region. Consequently multicultural education in geography would focus on the cultivation of regional identities which are founded on critical thinking to solve the conflicts of multicultural society. The geographic education in multicultural society would rather emphasize on region than on race or nation, and can integrate the global vision of world citizenship with the diverse viewpoint of multicultural education.

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Route Changes of Our Policy the Public Rental Housing -of Nest Housing and Happy Homes- (우리나라 공공임대주택정책의 경로변화 -보금자리 주택, 행복주택을 중심으로-)

  • Kim, Bog-Sig;Ryu, Ji-Seong
    • The Journal of the Korea Contents Association
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    • v.16 no.9
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    • pp.170-184
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    • 2016
  • The research is our public rental housing policy are 'Why' Did you no choice but to make the route changes, according to previous governments neo-institutional one fine history of care institutions, Historical analysis method and historical comparison system was complementary to the borders of the principle of hacke to appear (248 hacker, 2004 :) that the path to the model attempts to analyze a mix of evolution. Our country has a high degree of exodus due to industrialization and urbanization have caused and here, by means of side effects to housing was becoming serious social problems. Has this to solve housing problems governments have any policy to take a look at the latest. 5, 16 5,16 Military Coup caused by the advent of the Third Republic ; lack of legitimacy of the regime established, the Korea Housing Corporation randomness that for over the cracks and a consensus on the critical period of Public Rental Housing begins to engage in further studies in this study reported paths of Lee Myung-bak administration during the course of evolution 'of nest housing', and government 'happy homes', Park Geun-hye, a diagnose and address the state of the public rental housing policy by comparison, the next of Public Rental Housing A desirable destination of the study to present.

Evaluation of Corrected Dose with Inhomogeneous Tissue by using CT Image (CT 영상을 이용한 불균질 조직의 선량보정 평가)

  • Kim, Gha-Jung
    • The Journal of Korean Society for Radiation Therapy
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    • v.18 no.2
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    • pp.75-80
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    • 2006
  • Purpose: In radiation therapy, precise calculation of dose toward malignant tumors or normal tissue would be a critical factor in determining whether the treatment would be successful. The Radiation Treatment Planning (RTP) system is one of most effective methods to make it effective to the correction of dose due to CT number through converting linear attenuation coefficient to density of the inhomogeneous tissue by means of CT based reconstruction. Materials and Methods: In this study, we carried out the measurement of CT number and calculation of mass density by using RTP system and the homemade inhomogeneous tissue Phantom and the values were obtained with reference to water. Moreover, we intended to investigate the effectiveness and accuracy for the correction of inhomogeneous tissue by the CT number through comparing the measured dose (nC) and calculated dose (Percentage Depth Dose, PDD) used CT image during radiation exposure with RTP. Results: The difference in mass density between the calculated tissue equivalent material and the true value was ranged from $0.005g/cm^3\;to\;0.069g/cm^3$. A relative error between PDD of RTP and calculated dose obtained by radiation therapy of machine ranged from -2.8 to +1.06%(effective range within 3%). Conclusion: In conclusion, we confirmed the effectiveness of correction for the inhomogeneous tissues through CT images. These results would be one of good information on the basic outline of Quality Assurance (QA) in RTP system.

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