• 제목/요약/키워드: multi forming

검색결과 506건 처리시간 0.029초

한의학의 비과학성 논란에 대한 반박 (Refutation against the Non-Scientificity Argument on Korean Medicine)

  • 지규용
    • 동의생리병리학회지
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    • 제33권5호
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    • pp.249-254
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    • 2019
  • This study is aimed to refute against medical opponent's claim that Korean medicine does not conform to the conditions of science. Analyses and refutations against a journal treatise and a Facebook column formally written for a logical criticism and attack were conducted. As an example of the logic of the knowledge production process in Chinese medicine, 8 principle theory was exemplified in the Han danasty Classics "Neijing" and "Shanghanlun" at first. The knowledge was continuously revised and accumulated historically and then completed through Ming、Cheng period. The differential diagnosis and treatment theory is a logical process of forming knowledge through the process of abduction, deduction and induction begun from "Shanghanlun" succeeded to nowadays and it is essentially equaled with the process of experimental inference by Claude Bernard. Examples of normal science status based on Kuhn's scientific standards include the theory of 8 principle, differntial diagnosis of viscera and bowel, 3 yang and 3 yin diseases of "Shanghanlun" and warm disease theory. Examples of science lost or get its normal status by refutation following Popper's standards were cold damage theory and warm disease theory respectively. This allowed Chinese medicine to follow the general principles of science that form scientific knowledge and to correspond with the demarcation standards and concepts of science. However, as one of the conditions for becoming a science, Chinese medicine is partially lacking in terms of the interpretation of text language or the accordance with modern knowledge. Therefore methods are required to supplement this lack through multi-faceted research such as literature-based, theoretical and clinical studies.

Social Support for Social Commerce: An Empirical Study with Trust as a Mediator and Culture as Moderator

  • Hossain, Md. Alamgir;Jahan, Nusrat;Kim, Minho;Yesmin, Most. Nirufer;Hasan, Raquibul
    • Journal of Korea Trade
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    • 제25권7호
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    • pp.75-91
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    • 2021
  • Purpose - Social commerce (SC) is the growth of social media highlighting the e-commerce transactions and currently, the greatest challenges of e-commerce have attracted the influence of trust in social commerce intention (SCI). Based on the challenge, the study's purpose is to discover the effect of social support (informational and emotional support) on the SCI. The study also explores the mediation effect of trust and the moderation impact of culture between the USA and Korea. Design/methodology - This study used a sample of 482 surveys filled out by online shoppers from the US and Korea, two countries with divergent cultural values. Structural equation modelling (SEM) is used to analyze the hypothetical paths. In addition, bootstrapping and multi-group analysis are perform to view mediation and moderation effects respectively. Findings - The results of our study shows that both informational and emotional support significantly influences trust and SCI. Our results also supports the mediating effect of trust in social support and the moderating effect of culture in forming SCI. Originality/value - Our empirical results provide important information to businesses formulating cross-cultural SC strategies. This will help SC companies to analyze the aspects of customer trust through social support, which in turn will increase SCI and thereby established a competitive position for SCs. Our results will also be holistic directions for SC vendors in cross-cultural settings, which will offer important social and economic contributions to the sustainable growth of SC's business.

HP-CRTM 성형공법을 적용하기 위한 NCF 복합재 적층구조에 따른 인장특성 분석 (Tensile Property Analysis of NCF Composite Laminated Structure for HP-CRTM Forming Process)

  • 변기석;신유정;정한규;박시우;노춘수;제진수;권기철
    • 한국기계가공학회지
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    • 제18권1호
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    • pp.59-64
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    • 2019
  • In recent years, the HP-CRTM method, which has the ability to produce carbon fiber-reinforce plastic composites at high speeds, has come into the spotlight in the automotive parts industry, which demands high productivity. Multi-axial carbon fabric, an intermediate material used in this HP-CRTM molding process, consists of layered fibers without crimp, which makes it better in terms of tensile and shear strength than the original woven fabrics. The NCF (non-crimp fabric) can form the layers of the carbon fiber, which have different longitudinal and lateral directions, and ${\pm}{\theta}$ degrees, depending on the product's properties. In this research, preforms were made with carbon fibers of ${\pm}45^{\circ}$ and $0/90^{\circ}$, which were lamination structures under seven different conditions, in order to create the optimal laminated structure for automobile reinforcement center floor tunnels. Carbon fiber composites were created using each of the seven differently laminated preforms, and polyurethane was used as the base material. The specimens were manufactured in accordance with the ASTM D3039 standards, and the effect of the NCF lamination structure on the mechanical properties was confirmed by a tensile test.

Comparison of the Particulate Matter Removal Capacity of 11 Herbaceous Landscape Plants

  • Kwon, Kei-Jung;Odsuren, Uuriintuya;Kim, Sang-Yong;Yang, Jong-Cheol;Park, Bong-Ju
    • 인간식물환경학회지
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    • 제24권3호
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    • pp.267-275
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    • 2021
  • Background and objective: Particulate matter (PM) has a fatal effect on health. There have been many studies on the use of plants such as trees and shrubs as eco-friendly and sustainable biofilter for the removal of PM. In forming more green space, ground cover plants play an important role in multi-layered planting. This study was conducted to investigate the ability of plants to reduce PM, targeting Korean native ground cover plants with high availability in urban green spaces. Methods: For 4 species of Asteraceae, 4 species of Liliaceae, and 3 species of Rosaceae, one species of plants at a time were placed in an acrylic chamber (800 × 800 × 1000 mm, L × W × H) modeling an indoor space. After the injection of PM, the amount of PM remaining in the chamber over time was investigated. Results: For all three types of PM (PM10, PM2.5, PM1), significant difference occurred in the amount of PM remaining between plant species after 1 hour in the Liliaceae chamber, 3 hours in the Asteraceae chamber, and 5 hours in the Rosaceae chamber. With Liliaceae, the leaf area and the amount of PM remaining in the chamber showed a negative (-) correlation. With the Asteraceae and Rosaceae, there was a weak negative correlation between the leaf area and the amount of PM remaining in the chamber. Conclusion: When using ground cover plants as a biofilter to remove PM, it is considered effective to select a species with a large total leaf area, especially for Liliaceae.

해수담수화 농축수 처리를 위한 한국 해수 특성 및 결정화 연구 (Study on Korean Seawater Characterization and Crystallization for Seawater Desalination Brine Treatment)

  • 정상현;;변시영;이지은
    • 한국물환경학회지
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    • 제37권6호
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    • pp.442-448
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    • 2021
  • Seawater desalination is a technology through which salt and other constituents are removed from seawater to produce fresh water. While a significant amount of fresh water is produced, the desalination process is limited by the generation of concentrated brine with a higher salinity than seawater; this imposes environmental and economic problems. In this study, characteristics of seawater from three different locations in South Korea were analyzed to evaluate the feasibility of crystallization to seawater desalination. Organic and inorganic substances participating in crystal formation during concentration were identified. Then, prediction and economic feasibility analysis were conducted on the actual water flux and obtainable salt resources (i.e. Na2SO4) using membrane distillation and energy-saving crystallizer based on multi-stage flash (MSF-Cr). The seawater showed a rather low salinity (29.9~34.4 g/L) and different composition ratios depending on the location. At high concentrations, it was possible to observe the participation of dissolved organic matter and various ionic substances in crystalization. When crystallized, materials capable of forming various crystals are expected. However, it seems that different salt concentrations should be considered for each location. When the model developed using the Aspen Plus modular was applied in Korean seawater conditions, relatively high economic feasibility was confirmed in the MSF-Cr. The results of this study will help solve the environmental and economic problems of concentrated brine from seawater desalination.

Atorvastatin inhibits the proliferation of MKN45-derived gastric cancer stem cells in a mevalonate pathway-independent manner

  • Choi, Ye Seul;Cho, Hee Jeong;Jung, Hye Jin
    • The Korean Journal of Physiology and Pharmacology
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    • 제26권5호
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    • pp.367-375
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    • 2022
  • Gastric cancer stem cells (GCSCs) are a major cause of radioresistance and chemoresistance in gastric cancer (GC). Therefore, targeting GCSCs is regarded as a powerful strategy for the effective treatment of GC. Atorvastatin is a widely prescribed cholesterol-lowering drug that inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase, a rate-limiting enzyme in the mevalonate pathway. The anticancer activity of atorvastatin, a repurposed drug, is being investigated; however, its therapeutic effect and molecular mechanism of action against GCSCs remain unknown. In this study, we evaluated the anticancer effects of atorvastatin on MKN45-derived GCSCs. Atorvastatin significantly inhibited the proliferative and tumorsphere-forming abilities of MKN45 GCSCs in a mevalonate pathway-independent manner. Atorvastatin induced cell cycle arrest at the G0/G1 phase and promoted apoptosis by activating the caspase cascade. Furthermore, atorvastatin exerted an antiproliferative effect against MKN45 GCSCs by inhibiting the expression of cancer stemness markers, such as CD133, CD44, integrin α6, aldehyde dehydrogenase 1A1, Oct4, Sox2, and Nanog, through the downregulation of β-catenin, signal transducer and activator of transcription 3, and protein kinase B activities. Additionally, the combined treatment of atorvastatin and sorafenib, a multi-kinase targeted anticancer drug, synergistically suppressed not only the proliferation and tumorsphere formation of MKN45 GCSCs but also the in vivo tumor growth in a chick chorioallantoic membrane model implanted with MKN45 GCSCs. These findings suggest that atorvastatin can therapeutically eliminate GCSCs.

공공도서관 관련 교양과목 개발에 관한 연구 - '우리 모두의 장'으로서 공공도서관 알아차리기 - (A Study on the Development of Liberal Arts Subject Related to Public Libraries: Knowing Public Library as a Commons)

  • 한만성
    • 한국비블리아학회지
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    • 제34권2호
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    • pp.33-57
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    • 2023
  • 연구의 주요 목적은 공공도서관이 가진 '우리 모두의 장(공통장)'의 특성을 최대한 발견한 학습 구성요소 설계 및 대학의 일반교양 과목 요건에 부합하는 교육 내용 구성이다. 공공도서관은 다양한 문해력 향상의 연습장이자, 디지털 공유문화의 체험장, 차별 없는 모두의 학습장, 메이커 운동의 작업장 그리고 지역공동체 형성의 거점으로서 '우리 모두의 장'의 성격을 두루 갖추고 있다. 연구자는 다양한 문해력 이해, 정보활용능력의 정보윤리, 공동체 의식 및 다문화 이해, 공공의식과 협동정신 및 컴퓨터 활용능력, 학제적 지식 및 통합적 안목과 시각 등을 학습 구성요소로 설계하고 '공유문화와 지역도서관'이라는 명칭의 과목을 개설하였다. 이러한 공공도서관 관련 융합 교양 교과는 지역 및 공공성의 위기가 증대되는 상황에서 공공도서관의 가치를 학생들에게 널리 확산하고 실제로다양한 도서관 서비스를 체험하도록 유도함으로써 지역도서관의 인지도 및 이용률 향상을 견인할 것으로 기대된다.

Modeling and experimental verification of phase-control active tuned mass dampers applied to MDOF structures

  • Yong-An Lai;Pei-Tzu Chang;Yan-Liang Kuo
    • Smart Structures and Systems
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    • 제32권5호
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    • pp.281-295
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    • 2023
  • The purpose of this study is to demonstrate and verify the application of phase-control absolute-acceleration-feedback active tuned mass dampers (PCA-ATMD) to multiple-degree-of-freedom (MDOF) building structures. In addition, servo speed control technique has been developed as a replacement for force control in order to mitigate the negative effects caused by friction and inertia. The essence of the proposed PCA-ATMD is to achieve a 90° phase lag for a structure by implementing the desired control force so that the PCA-ATMD can receive the maximum power flow with which to effectively mitigate the structural vibration. An MDOF building structure with a PCA-ATMD and a real-time filter forming a complete system is modeled using a state-space representation and is presented in detail. The feedback measurement for the phase control algorithm of the MDOF structure is compact, with only the absolute acceleration of one structural floor and ATMD's velocity relative to the structure required. A discrete-time direct output-feedback optimization method is introduced to the PCA-ATMD to ensure that the control system is optimized and stable. Numerical simulation and shaking table experiments are conducted on a three-story steel shear building structure to verify the performance of the PCA-ATMD. The results indicate that the absolute acceleration of the structure is well suppressed whether considering peak or root-mean-square responses. The experiment also demonstrates that the control of the PCA-ATMD can be decentralized, so that it is convenient to apply and maintain to real high-rise building structures.

Multivesicular bodies 및 Cytolysomes에 관(關)한 전자현미경적(電子顯微鏡的) 연구(硏究)

  • 김우갑;김창환;박홍덕;양희영
    • Applied Microscopy
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    • 제6권1호
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    • pp.21-32
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    • 1976
  • Rhizopus nigricans, Aspergillus niger, Aspergillus ochraceus의 균계 Agricus bisporus, Rhizopogon rubescens의 자실층균계 및 담자기세포, Marchantia polymorpha, Pogonatum inflexum, Pteridium aqiulium 의 동화조직, Pinus densiflora, Ginkgo biloba, Panax ginseng 의 엽육조직의 소편을 glutaralehyde-paraformalehyde 및 $OsO_4$에 고정하여 다소포체 및 세포질용해체와 관련된 다양상인 막성구조의 기원과 기능에 관하여 전 자현미경적으로 추구하였다. Rhizopus nigricans, Aspergillus niger, A. ochraceus, Agricus bisporus, Rhizopogon rubescens 의 동심원상인 다층막, 미에린一소포-관상구조의 복합체, 평행다층막구조등은 원형질막에서 유래된다. Marchantia polymorpha, Pogonatum inflexum, Pteridium aquilinum, Pinus densiflora, Ginkgo biloba, Panax ginseng 에 있어서 pinocytotic vesicles 외에 다양상안 막성구조는 원형질막과 세포질안의 무과립성 소포체에서 유래된다. 원형질막에서 유래되는 것은 다소포체인 것과 미에린 양구조인 것으로 구분되고, 이것은 2차액포를 형성하거나 또는 1차액포안으로 유리되어 퇴화한다. 세포질안의 소포체가 세포질의 일부를 포위하고 그 내부에 막증식과 더불어 세포질이 감소되면서 다층막구조로 변하고, 이것은 액포안으로 유리되어 퇴화한다. 세포질의 소포체에서 유래되는 것은 액포분화와 밀접한 관계가 있는 세포질분리체 또는 세포용해체인 것으로 믿어진다.

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특수주입선단장치에 의한 마이크로시멘트계 약액주입의 풍화대, 단층파쇄대의 지반보강 및 차수효과 사례연구 (A Case Studty on the Ground Reinforcement and Waterproofing Effect of Weathering and Fault Zone by Special Injection Tip Equipment Using Microcement Type)

  • 도종남;정종주;천병식
    • 한국지반환경공학회 논문집
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    • 제10권2호
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    • pp.21-28
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    • 2009
  • 최근 고속철도, 지하철, 댐, 항만, 고속도로, 도심지의 주상복합건물 등 대형 건설공사가 진행되면서 약액주입공법, 고압분사주입공법, 혼합처리공법 등이 다양하게 적용되고 있으나 침투성, 강도, 내구성, 환경성, 주변지반의 융기, 지하매설물에 대한 영향, 산업폐기물발생 등 많은 문제점이 지적되어 왔다. 이에 본 연구에서는 특수 주입선단장치 및 변성실리케이트 재료를 개발하여 주입재료의 혼합이 용이하고 주입중 주입재의 역류 및 주입노즐의 막힘이 없이 연속작업이 가능하며, 분말도 $6,000cm^2/g$이상인 마이크로시멘트를 사용 침투효과를 증가시켰다. 또한, 겔형성반응재는 내구성과 환경성에 영향을 끼치는 $Na_2O$ 함량을 대폭 낮춘 변성실리케이트를 개발하여 지하수에 의한 용탈현상을 최소화하고, 장기의 고강도, 고침투, 고내구성, 친환경성이 요구되는 곳에 적합한 마이크로 무기질급결재를 개발하여 실용화에 대한 연구를 수행하였다. 연구결과 일축압축강도, 투수성, N치 및 TCR, RQD 등이 개선됨을 알 수 있었으며, 향후 본 연구결과를 바탕으로 특수 주입선단장치를 활용한 다양한 현장적용성 시험을 추후 시행하여 타공법과 공학적 특성을 비교, 검토하고자 한다.

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