• Title/Summary/Keyword: PML

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A Finite Element Based PML Method for Time-domain Electromagnetic Wave Propagation Analysis (시간영역 전자기파 전파해석을 위한 유한요소기반 PML 기법)

  • Yi, Sang-Ri;Kim, Boyoung;Kang, Jun Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.2
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    • pp.123-130
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    • 2015
  • This paper presents a new formulation for transient simulations of microwave propagation in heterogeneous unbounded domains. In particular, perfectly-matched-layers(PMLs) are introduced to allow for wave absorption at artificial boundaries used to truncate the infinite extent of the physical domains. The development of the electromagnetic PML targets the application to engineering mechanics problems such as structural health monitoring and inverse medium problems. To formulate the PML for plane electromagnetic waves, a complex coordinate transformation is introduced to Maxwell's equations in the frequency-domain. Then the PML-endowed partial differential equations(PDEs) for transient electromagnetic waves are recovered by the application of the inverse Fourier transform to the frequency-domain equations. A mixed finite element method is employed to solve the time-domain PDEs for electric and magnetic fields in the PML-truncated domain. Numerical results are presented for plane microwaves propagating through concrete structures, and the accuracy of solutions is investigated by a series of error analyses.

Numerical Analysis of Dynamic Response of Floating Offshore Wind Turbine to the Underwater Explosion using the PML Non-reflecting Technique (PML 무반사 기법을 이용한 부유식 해상풍력발전기의 수중폭발에 따른 동응답 수치해석)

  • Cho, Jin-Rae;Jeon, Soo-Hong;Jeong, Weui-Bong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.6
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    • pp.521-527
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    • 2016
  • This paper is concerned with the numerical analysis of dynamic response of floating offshore wind turbine subject to underwater explosion using an effective non-reflecting technique. An infinite sea water domain was truncated into a finite domain, and the non-reflecting technique called the perfectly matched layer(PML) was applied to the boundary of truncated finite domain to absorb the inherent reflection of out-going impact wave at the boundary. The generalized transport equations that govern the inviscid compressible water flow was split into three PML equations by introducing the direction-wise absorption coefficients and state variables. The fluid-structure interaction problem that is composed of the wind turbine and the sea water flow was solved by the iterative coupled Eulerian FVM and Largangian FEM. And, the explosion-induced hydrodynamic pressure was calculated by JWL(Jones-Wilkins-Lee) equation of state. Through the numerical experiment, the hydrodynamic pressure and the structural dynamic response were investigated. It has been confirmed that the case using PML technique provides more reliable numerical results than the case without using PML technique.

Time harmonic analysis of dam-foundation systems by perfectly matched layers

  • Khazaee, Adib;Lotfi, Vahid
    • Structural Engineering and Mechanics
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    • v.50 no.3
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    • pp.349-364
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    • 2014
  • Perfectly matched layers are employed in time harmonic analysis of dam-foundation systems. The Lysmer boundary condition at the truncation boundary of the PML region has been incorporated in the formulation of the dam-foundation FE model (including PML). The PML medium is defined in a way that the formulation of the system can be transformed into time domain. Numerical experiments show that applying Lysmer boundary conditions at the truncation boundary of the PML area reduces the computational cost and make the PML approach a more efficient technique for the analysis of dam-foundation systems.

An Exploratory Study of Hope Structures of the Newly Diagnosed Cancer Patients (진단 초기 암환자의 희망구조 파악을 위한 탐색적 연구)

  • Park, Moon-Kyoung;Kim, Dal-Sook
    • Asian Oncology Nursing
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    • v.9 no.2
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    • pp.114-121
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    • 2009
  • Purpose: This study was to explore the hope structures of the newly diagnosed cancer patients by examining the relationships between hope and the three concepts of 'Personal Spirit', 'Risk' and 'Authentic Caring' which composed the multidimensions of the Nekolaichuk and Bruera's hope model. Methods: Data was collected via survey from 32 newly diagnosed cancer patients. The perceived meaning of life (PML) for 'personal spirit', perceived confidence in cure (PCC) for 'risk', and perceived family support (PFS) and perceived support from medical team (PSM) for 'authentic caring' were adapted from the definitions of the concepts in the model. Hope, PML, and PCC were measured with VAS. PFS and PSM were measured with Korean version of 'Cobb's family support scale', which was modified by Kang. Pearson correlation coefficients were used to identify the relationships among the concepts. Results: The significant relationships were revealed between hope and PCC (p<.001), hope and PML (p<.001), PML and PCC (p<.001), PFS and PML (p=.030), and PSM and PML (p=.047). Conclusion: The newly diagnosed cancer patients experience hope in different ways. The cancer patients' hope immediate after diagnosis, however, is most likely to be experienced as seeking balance between uncertainty about cancer treatment and the meaning of life.

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20(S)-ginsenoside Rh2 induces caspase-dependent promyelocytic leukemia-retinoic acid receptor A degradation in NB4 cells via Akt/Bax/caspase9 and TNF-α/caspase8 signaling cascades

  • Zhu, Sirui;Liu, Xiaoli;Xue, Mei;Li, Yu;Cai, Danhong;Wang, Shijun;Zhang, Liang
    • Journal of Ginseng Research
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    • v.45 no.2
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    • pp.295-304
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    • 2021
  • Background: Acute promyelocytic leukemia (APL) is a hematopoietic malignancy driven by promyelocytic leukemia-retinoic acid receptor A (PML-RARA) fusion gene. The therapeutic drugs currently used to treat APL have adverse effects. 20(S)-ginsenoside Rh2 (GRh2) is an anticancer medicine with high effectiveness and low toxicity. However, the underlying anticancer mechanisms of GRh2-induced PML-RARA degradation and apoptosis in human APL cell line (NB4 cells) remain unclear. Methods: Apoptosis-related indicators and PML-RARA expression were determined to investigate the effect of GRh2 on NB4 cells. Z-VAD-FMK, LY294002, and C 87, as inhibitors of caspase, and the phosphatidylinositol 3-kinase (PI3K) and tumor necrosis factor-α (TNF-α) pathways were used to clarify the relationship between GRh2-induced apoptosis and PML-RARA degradation. Results: GRh2 dose- and time-dependently decreased NB4 cell viability. GRh2-induced apoptosis, cell cycle arrest, and caspase3, caspase8, and caspase9 activation in NB4 cells after a 12-hour treatment. GRh2-induced apoptosis in NB4 cells was accompanied by massive production of reactive oxygen species, mitochondrial damage and upregulated Bax/Bcl-2 expression. GRh2 also induced PML/PML-RARA degradation, PML nuclear bodies formation, and activation of the downstream p53 pathway in NB4 cells. Z-VAD-FMK inhibited caspase activation and significantly reversed GRh2-induced apoptosis and PML-RARA degradation. GRh2 also upregulated TNF-α expression and inhibited Akt phosphorylation. LY294002, an inhibitor of the PI3K pathway, enhanced the antitumor effects of GRh2, and C 87, an inhibitor of the TNF-α pathway, reversed NB4 cell viability, and GRh2-mediated apoptosis in a caspase-8-dependent manner. Conclusion: GRh2 induced caspase-dependent PML-RARA degradation and apoptosis in NB4 cells via the Akt/Bax/caspase9 and TNF-α/caspase8 pathways.

Application of Effective Earthquake Force by the Boundary Reaction Method and a PML for Nonlinear Time-Domain Soil-Structure Interaction Analysis of a Standard Nuclear Power Plant Structure (원전구조물의 비선형 시간영역 SSI 해석을 위한 경계반력법에 의한 유효지진하중과 PML의 적용)

  • Lee, Hyeok Ju;Lim, Jae Sung;Moon, Il Hwan;Kim, Jae Min
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.1
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    • pp.25-35
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    • 2023
  • Considering the non-linear behavior of structure and soil when evaluating a nuclear power plant's seismic safety under a beyond-design basis earthquake is essential. In order to obtain the nonlinear response of a nuclear power plant structure, a time-domain SSI analysis method that considers the nonlinearity of soil and structure and the nonlinear Soil-Structure Interaction (SSI) effect is necessary. The Boundary Reaction Method (BRM) is a time-domain SSI analysis method. The BRM can be applied effectively with a Perfectly Matched Layer (PML), which is an effective energy absorbing boundary condition. The BRM has a characteristic that the magnitude of the response in far-field soil increases as the boundary interface of the effective seismic load moves outward. In addition, the PML has poor absorption performance of low-frequency waves. For this reason, the accuracy of the low-frequency response may be degraded when analyzing the combination of the BRM and the PML. In this study, the accuracy of the analysis response was improved by adjusting the PML input parameters to improve this problem. The accuracy of the response was evaluated by using the analysis response using KIESSI-3D, a frequency domain SSI analysis program, as a reference solution. As a result of the analysis applying the optimal PML parameter, the average error rate of the acceleration response spectrum for 9 degrees of freedom of the structure was 3.40%, which was highly similar to the reference result. In addition, time-domain nonlinear SSI analysis was performed with the soil's nonlinearity to show this study's applicability. As a result of nonlinear SSI analysis, plastic deformation was concentrated in the soil around the foundation. The analysis results found that the analysis method combining BRM and PML can be effectively applied to the seismic response analysis of nuclear power plant structures.

HS-1200 Overcomes the Resistance Conferred by Bcl-2 in Human Leukemic U937 Cells

  • Park, Jun-Young;Moon, Jeong-Bon;Kim, In-Ryoung;Kim, Gyoo-Cheon;Park, Bong-Soo;Kwak, Hyun-Ho
    • International Journal of Oral Biology
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    • v.37 no.3
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    • pp.91-102
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    • 2012
  • Bcl-2 protects tumor cells from the apoptotic effects of various anti-neoplastic agents. Increased expression of Bcl-2 has been associated with a poor response to chemotherapy in various malignancies, including leukemia. Hence, bypassing the resistance conferred by anti-apoptotic factors such as Bcl-2 represents an attractive therapeutic strategy against cancer cells, including leukemic cells. This study was undertaken to examine whether the anticancer drug, cisplatin and the synthetic chenodeoxycholic acid (CDCA) derivative, HS-1200 show anti-tumor activity in U937 and U937/Bcl-2 cells. Viability assays revealed that HS-1200 overcomes the resistance conferred by Bcl-2 in human leukemic U937 cells. Various apoptosis assessment assays further demonstrated that HS-1200 overcomes the resistance conferred by Bcl-2 in human leukemic U937 cells by inducing apoptosis. In addition HS-1200, but not cisplatin, overcomes the anti-apoptotic effects of Bcl-2 in Bcl-2 over-expressing human leukemic cells (U937/Bcl-2 cells). Notably, we observed that the HS-1200-induced formation of mature promyelocytic leukemia (PML) nuclear bodies (NBs) correlates with a suppression of the anti-apoptotic effects of Bcl-2 in human leukemic cells over-expressing this protein (U937/Bcl-2 cells). Furthermore, HS-1200 was found to induce the association between PML and SUMO-1, Daxx, Sp100, p53 or CBP in the aggregated PML-NBs of U937/Bcl-2 cells. Thus, PML protein and the formation of mature PML-NBs could be considered as therapeutic targets that may help to bypass the resistance to apoptosis conferred by Bcl-2. Elucidating the exact mechanism by which PML regulates Bcl-2 will require further work.

A Design of Data Model for Electronic Tag Information Processing in Logistics Distribution Service Parts (물류 유통 서비스 분야에서 전자태그 정보 처리를 위한 데이터 모델 설계)

  • Kim Chang-su;Hong Sung-Chan;Jung Hoe-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.4
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    • pp.712-719
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    • 2005
  • As computing paradigm of the next generation, Ubiquitous Computing has emerged owing to growing of the Internet and computer networking technologies, and RFID (Radio Frequency Identification) which is the core technology to achieve(realize,actualize) the Ubiquitous Computing environment, is being noticed. MIT's Auto-ID Center has proposed PML(Physical Markup Language) which is based on XML (Extensible Markup Language), is a standard language for describing physical objects, in order to interchange of data between each of these RFID application systems. The PML defines only core parts to describe physical objects, but on the other hand the other parts to be needed in practical application have to be defined with extended definitions separately. In this paper, therefore, the object information data model was designed, which defines the type of the object in order. to process electronic tag information in the RFID application service based on PML Core of Auto-ID Center and is applicable to the distribution service parts.

Distributed REID Information Service Architecture for Ubiquitous Logistics (유비쿼터스 물류를 위한 분산형 RFID 정보서비스 구조)

  • Lee, Jae-Won;Lee, Young-Koo
    • Journal of Intelligence and Information Systems
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    • v.11 no.2
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    • pp.105-121
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    • 2005
  • To realize a ubiquitous logistics management system using the smart object of Electronic Product Code(EPC) enabled RFID tag, the design and management of RFID Information Service is very important. RFID Information Service searches, transfers and responds to the other's PML request, but Physical Markup Language (PML) data management between trading system elements has issues of standardization of PML data description and processing, and problems of data traffic and communication time overload because of the innate distributed characteristics. As a complementary study, this research analyzes the usage patterns and data types of PML. On that analysis we provide a design of the distributed RFID Information Service architecture of PML data management that is using DB middleware. Standalone and Integrated type of RFID IS were proposed.

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New Perfectly Matched Layer for Absorbing Evanescent Modes in FDTD (FDTD에서 감쇄 모드 흡수를 위한 새로운 Perfectly Matched Layer)

  • 이재용;명노훈
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.4
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    • pp.592-598
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    • 2000
  • The existin Berenger's PML(Perfectly Matched Layer) cannot absorb evanescent modes effectively generated in waveguides or periodic array structures. Although some absorbing boundary conditons(ABC) were introduced to absorp the evanescent modes, they did not show sufficient performance or could not be applied easily because of their much difference from Berengers PML. In this paper, NPML(New PML) is introduced to absorb the evanescent modes by splitting the conductivity and permittivity profile of the Berengers PML. The proposed NPML is certified as an ABC having enough performance for evanescent and propagating modes by analyzing the global error and the reflectivity of a waveguide.

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