• 제목/요약/키워드: EBM

검색결과 163건 처리시간 0.027초

지하 공간 설계와 시공의 지반공학적 접근과 실무적용 -지반계수의 합리적 추정 (Geotechnical Approach in Design and Construction of Underground Structures A Systematic Parameter Estimation)

  • 이인모;김동현
    • 한국지반공학회지:지반
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    • 제12권2호
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    • pp.43-58
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    • 1996
  • 지하구조물에 대한 설계 및 시공기술의 많은 발전에도 불구하고 아직도 상당부분 그간의 경험에 의존하며, 또한 많은 불확정성 요소들을 내포하고 있다. 그 중 가장 대표되는 것이 지반계수로서, 이를 설계단계에서 정확히 산정하는 데는 많은 어려움이 따른다. 본 논문의 주된 목적은 지하공간의 설계와 시공을 유기적으로 연결할 수 있는 지반공학적 접근의 일환으로 최적의 지반계수를 산정하는 데 있다. 이를 위하여 초기예측치와 계측치로부터 예측된 간을 합리적으로 조합할 수 있는 Extended Bayesian Method(EBM)을 적용하였으며, 이를 유한요소해석으로부터 구할 수 있도록 하였다. 또한 부산 지하철 현장과 캐나다의 Darlington취수터널에 대한 예제해석을 수행하여 제안된 방법의 효용성을 검증하였다.

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확장 Baysian 방법과 상대변위를 이용한 터널 역해석 기법의 적용사례연구 (A Case Study of Back-analysis Technique in Tunnelling Using Extended Bayesian Method and Relative Convergence Measurement)

  • 이인모;최민광;조국환;이근하;최충식
    • 한국지반공학회논문집
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    • 제21권3호
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    • pp.109-118
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    • 2005
  • 터널과 같은 선형 구조물의 경우, 터널이 시공될 지반의 전체적인 상태를 설계단계에서 정확히 파악하기는 매우 힘든 것이 사실이다. 따라서 시공과정에서 획득되어지는 계측자료와 설계단계에의 사전정보를 적절히 조합하는 피드백(feed-back)과정이 필수적이게 된다. 본 논문에서는 터널 내에서 계측된 상대변위만을 역해석 입력값으로 적용한 3차원 터널 역해석 기법을 이용하여 터널 주변 지반의 최적의 지반정수를 평가하였다. 이를 위하여 예측치와 계측치를 합리적으로 조합할 수 있는 확장 Bayesian 방법(Extended Bayesian Meoth EBM)을 역해석의 목적함수로 사용하였으며, 터널 내공변위 예측을 위해 3차원 수치해석을 적용하였다. 두 곳의 실제 터널 현장계측자료를 바탕으로 역해석을 수행하였으며, 이를 통하여 제안된 역해석 기법의 효용성을 검증하였다.

한방의료기관의 한약 관리 및 가격 현황에 대한 연구 (A Survey of the Status of Management and Prices of Herbal Medicines: Traditional Korean Medicine Institutions)

  • 황대선;신현규
    • 대한한의학회지
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    • 제32권5호
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    • pp.90-99
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    • 2011
  • Objectives: Comparison of the status of herbal medicine management carried out by traditional Korean medicine hospitals and clinics, and changes in the prices of the herbal medicines offered by them. Methods: A questionnaire survey was conducted for 126 traditional Korean medicine hospitals and 4,200 traditional Korean medicine clinics. Questionnaire sheets were dispatched to them by mail in 2008. Rate of response: 57 hospitals (45.2%) and 465 clinics (11.0%) Results: 1. Concerning the herbal medicines kept by them, the hospitals and the clinics kept 295 and 147 kinds of medicine, respectively, on average. As for their monthly expenditure on the purchase of herbal medicines, the hospitals spent an average of KRW 28.38 million while the clinics spent an average of KRW 1.64 million. 2. The average monthly expenditure of the clinics on the purchase of herbal medicines decreased by 32% from 2006, which can be interpreted as a reduction of their business. 3. The prices of herbal medicines for disease treatment ranged from KRW 140,000~190,000 per jae(dosage form) in the hospitals compared to KRW 140,000~168,000 in the clinics. 4. Compared to 1994, the prices of herbal medicines used for disease treatment have risen, whereas the prices of herbal medicines used as tonics have decreased. Conclusions: There are no conspicuous differences between the hospitals and the clinics in terms of the prices charged for herbal medicines, regardless of whether they are used to treat diseases or prescribed as tonics.

분말 3D 프린팅된 Ti-6Al-4V 합금의 피로특성에 미치는 후열처리의 영향 (Effect of post heat treatment on fatigue properties of EBM 3D-printed Ti-6Al-4V alloy)

  • 최영신;장지훈;김건희;이창우;김휘준;이동근
    • 한국분말재료학회지
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    • 제25권4호
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    • pp.340-345
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    • 2018
  • Additive manufacturing by electron beam melting is an affordable process for fabricating near net shaped parts of titanium and its alloys. 3D additive-manufactured parts have various kinds of voids, lack of fusion, etc., and they may affect crack initiation and propagation. Post process is necessary to eliminate or minimize these defects. Hot isostatic pressing (HIP) is the main method, which is expensive. The objective of this paper is to achieve an optimum and simple post heat treatment process without the HIP process. Various post heat treatments are conducted for the 3D-printed Ti-6Al-4V specimen below and above the beta transus temperature ($996^{\circ}C$). The as-fabricated EBM Ti-6Al-4V alloy has an ${\alpha}^{\prime}$-martensite structure and transforms into the ${\alpha}+{\beta}$ duplex phase during the post heat treatment. The fatigue strength of the as-fabricated specimen is 400 MPa. The post heat treatment at $1000^{\circ}C/30min/AC$ increases the fatigue strength to 420 MPa. By post heat treatment, the interior pore size and the pore volume fraction are reduced and this can increase the fatigue limit.

당뇨병성신병증(糖尿病性腎病證)의 활용 처방 및 약물에 관한 연구 (Study on Practical Prescription and It's Drug Composition for the Treatment of Diabetic Nephropathy)

  • 김동희
    • 동의생리병리학회지
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    • 제21권6호
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    • pp.1365-1380
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    • 2007
  • Based on the theories and clinical data of oriental medicine, traditional medicinal prescriptions known to be effective to diabetic nephropathy were collected. The prescriptions were carefully examined and analyzed in order to be used as fundamental material for experiments and in clinicals. More than 40 publications related to diabetes were arranged and analyzed. Of the complications, diabetic nephropathy part of the publications were specifically focused during analysis. Data were analyzed and classified according to the quantity, prescription, differentiation of symptoms, signs and addition and subtraction of each medicine. Frequently used medicines were statistically analyzed. The most frequently used prescription was Yukmigihwang-tang(六味地黃湯) based medicine and prescriptions of its addition and subtraction, which was 15% of the total prescriptions cited. The most frequently used medicine was Astragali Radix, mentioned 192 times in the prescriptions. Hoelen was next with 180 citations, followed by Dioscoreae Rhizoma with 147 times, Rehmanniae Radix with 140, Corni Fructus with 131, Salviae Miltiorrhizae Radix with 106, Angelicae Gigantis Radix with 101, Alismatis Rhizoma with 95, Rhei Rhizoma with 90, Atractylodis Rhizoma Alba with 84, Rehmanniae Radix Preparata with 78, Leonuri Herba with 74, Moutan Cortex Radicis with 66, Aconiti Lateralis Preparata Radix with 66 Cnidii Rhizoma with 65, Pseudostellaria heterophylla with 62, Liriopis Tuber with 55, Lycii Fructus with 52, Rhei Rhizoma with 49, Codonopsis Pilosulae Radix with 44, Paeoniae Radix Rubra with 44, Schisandrae Fructus with 42, Polyporus with 42, Achyranthis Radix with 41 and Euryales Semen with 40. Medicines prescribed more than 30 grams a day included Astragali Radix, Imperatae Rhizoma, Benincasae Pericarpium, Leonuri Herba, Dioscoreae Rhizoma, Plantaginis Semen, Polyporus, Hoelen, Halloysitum Rubrum, Achyranthis Radix, Arecae Pericarpium, Phaseoli Angularis Semen, Coicis Semen, Rhei Rhizoma, Salviae Miltiorrhizae Radix, Sargassum, Ostreae Concha, Pseudostellaria heterophylla, Epimedii Herba, Rehmanniae Radix, Scrophulariae Radix and Polygonati Rhizoma. No scientific reports on the traditional medicinal aspects of diabetic nephropathy was searched. This analysis report would be able to provide the basis of developing new drug candidates for the treatment of diabetic nephropathy, as well as securing the EBM for the traditional medicines already being prescribed to the patients.

Design and 3D-printing of titanium bone implants: brief review of approach and clinical cases

  • Popov Jr, Vladimir V.;Muller-Kamskii, Gary;Kovalevsky, Aleksey;Dzhenzhera, Georgy;Strokin, Evgeny;Kolomiets, Anastasia;Ramon, Jean
    • Biomedical Engineering Letters
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    • 제8권4호
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    • pp.337-344
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    • 2018
  • Additive manufacturing (AM) is an alternative metal fabrication technology. The outstanding advantage of AM (3D-printing, direct manufacturing), is the ability to form shapes that cannot be formed with any other traditional technology. 3D-printing began as a new method of prototyping in plastics. Nowadays, AM in metals allows to realize not only net-shape geometry, but also high fatigue strength and corrosion resistant parts. This success of AM in metals enables new applications of the technology in important fields, such as production of medical implants. The 3D-printing of medical implants is an extremely rapidly developing application. The success of this development lies in the fact that patient-specific implants can promote patient recovery, as often it is the only alternative to amputation. The production of AM implants provides a relatively fast and effective solution for complex surgical cases. However, there are still numerous challenging open issues in medical 3D-printing. The goal of the current research review is to explain the whole technological and design chain of bio-medical bone implant production from the computed tomography that is performed by the surgeon, to conversion to a computer aided drawing file, to production of implants, including the necessary post-processing procedures and certification. The current work presents examples that were produced by joint work of Polygon Medical Engineering, Russia and by TechMed, the AM Center of Israel Institute of Metals. Polygon provided 3D-planning and 3D-modelling specifically for the implants production. TechMed were in charge of the optimization of models and they manufactured the implants by Electron-Beam Melting ($EBM^{(R)}$), using an Arcam $EBM^{(R)}$ A2X machine.

지속가능한 신발 소비자의 구매의사결정과정에 관한 탐색적 연구 (An Explorative Study on the Purchase Decision-Making Process of Sustainable Shoes Consumers)

  • 임소라;신은정;고애란
    • Human Ecology Research
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    • 제61권3호
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    • pp.389-399
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    • 2023
  • Sustainable fashion products have different characteristics from typical fashion products. Therefore, this study focuses on shoes while exploring the expansion and development of sustainable fashion consumption as well as consumers' perceptions of the sustainability approaches practiced by shoe companies. In-depth interviews were conducted with 24 consumers, who had purchased sustainable shoes, in order to understand their purchase decision-making process and consumption characteristics, using the seven stages of the EBM model. In the "need recognition" stage, the survey participants' social background and family influences were categorized as macro factors, while their personal background influences were categorized as micro factors. In the "evaluation of alternatives" stage, participants reconfirmed whether or not to make a purchase based on the product's properties, such as price, brand value, and offered services. In the "purchase" stage, participants' purchase channels were determined according to their preferences as well as the selection pattern they followed until the final purchase within the chosen channel. In the "consumption" stage, the start of product ownership coincides with the start of using the products after making a purchase. In the "post-purchase assessment" stage, higher positive experiences led to a higher repurchase intention of sustainable shoes, while negative experiences caused participants to defer consumption and made them experience a sense of guilt for failing to consume sustainably. During the "post-purchase behavior" stage, which focused on the categories that the customers prioritized, many participants spread information about sustainable fashion to specific individuals through active online WOM behavior.

Limited in vitro differentiation of porcine induced pluripotent stem cells into endothelial cells

  • In-Won Lee;Hyeon-Geun Lee;Dae-Ky Moon;Yeon-Ji Lee;Bo-Gyeong Seo;Sang-Ki Baek;Tae-Suk Kim;Cheol Hwangbo;Joon-Hee Lee
    • 한국동물생명공학회지
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    • 제38권3호
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    • pp.109-120
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    • 2023
  • Background: Pluripotent stem cells (PSCs) including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) offer the immense therapeutic potential in stem cell-based therapy of degenerative disorders. However, clinical trials of human ESCs cause heavy ethical concerns. With the derivation of iPSCs established by reprogramming from adult somatic cells through the transgenic expression of transcription factors, this problems would be able to overcome. In the present study, we tried to differentiate porcine iPSCs (piPSCs) into endothelial cells (ECs) for stem cell-based therapy of vascular diseases. Methods: piPSCs (OSKMNL) were induced to differentiation into ECs in four differentiation media (APEL-2, APEL-2 + 50 ng/mL of VEGF, EBM-2, EBM-2 + 50 ng/mL of VEGF) on cultured plates coated with matrigel® (1:40 dilution with DMEM/F-12 medium) for 8 days. Differentiation efficiency of these cells were exanimated using qRT-PCR, Immunocytochemistry, Western blotting and FACS. Results: As results, expressions of pluripotency-associated markers (OCT-3/4, SOX2 and NANOG) were higher observed in all porcine differentiated cells derived from piPSCs (OSKMNL) cultured in four differentiation media than piPSCs as the control, whereas endothelial-associated marker (CD-31) in the differentiated cells was not expressed. Conclusions: It can be seen that piPSCs (OSKMNL) were not suitable to differentiate into ECs in the four differentiation media unlike porcine epiblast stem cells (pEpiSCs). Therefore, it would be required to establish a suitable PSCs for differentiating into ECs for the treatment of cardiovascular diseases.

Accurate analytical solutions for nonlinear oscillators with discontinuous

  • Bayat, Mahdi;Bayat, Mahmoud;Pakar, Iman
    • Structural Engineering and Mechanics
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    • 제51권2호
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    • pp.349-360
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    • 2014
  • In this study, three approximate analytical methods have been proposed to prepare an accurate analytical solution for nonlinear oscillators with fractional potential. The basic idea of the approaches and their applications to nonlinear discontinuous equations have been completely presented and discussed. Some patterns are also presented to show the accuracy of the methods. Comparisons between Energy Balance Method (EBM), Variational Iteration Method (VIM) and Hamiltonian Approach (HA) shows that the proposed approaches are very close together and could be easily extend to conservative nonlinear vibrations.

Accurate periodic solution for nonlinear vibration of thick circular sector slab

  • Pakar, Iman;Bayat, Mahmoud;Bayat, Mahdi
    • Steel and Composite Structures
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    • 제16권5호
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    • pp.521-531
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    • 2014
  • In this paper we consider a periodic solution for nonlinear free vibration of conservative systems for thick circular sector slabs. In Energy Balance Method (EBM) contrary to the conventional methods, only one iteration leads to high accuracy of the solutions. The excellent agreement of the approximate frequencies and periodic solutions with the exact ones could be established. Some patterns are given to illustrate the effectiveness and convenience of the methodology. Comparing with numerical solutions shows that the energy balance method can converge to the numerical solutions very rapidly which are valid for a wide range of vibration amplitudes as indicated in this paper.