• Title/Summary/Keyword: minimal model

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Numerical Research on Suppression of Thermally Induced Wavefront Distortion of Solid-state Laser Based on Neural Network

  • Liu, Hang;He, Ping;Wang, Juntao;Wang, Dan;Shang, Jianli
    • Current Optics and Photonics
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    • v.6 no.5
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    • pp.479-488
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    • 2022
  • To account for the internal thermal effects of solid-state lasers, a method using a back propagation (BP) neural network integrated with a particle swarm optimization (PSO) algorithm is developed, which is a new wavefront distortion correction technique. In particular, by using a slab laser model, a series of fiber pumped sources are employed to form a controlled array to pump the gain medium, allowing the internal temperature field of the gain medium to be designed by altering the power of each pump source. Furthermore, the BP artificial neural network is employed to construct a nonlinear mapping relationship between the power matrix of the pump array and the thermally induced wavefront aberration. Lastly, the suppression of thermally induced wavefront distortion can be achieved by changing the power matrix of the pump array and obtaining the optimal pump light intensity distribution combined using the PSO algorithm. The minimal beam quality β can be obtained by optimally distributing the pumping light. Compared with the method of designing uniform pumping light into the gain medium, the theoretically computed single pass beam quality β value is optimized from 5.34 to 1.28. In this numerical analysis, experiments are conducted to validate the relationship between the thermally generated wavefront and certain pumping light distributions.

Comparison of porcine and human acellular dermal matrix outcomes in wound healing: a deep dive into the evidence

  • Saricilar, Erin Cihat;Huang, Sarah
    • Archives of Plastic Surgery
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    • v.48 no.4
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    • pp.433-439
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    • 2021
  • Acellular dermal matrices (ADM) are a novel graft. The goal of this systematic review is to evaluate the evidence behind differences in human and porcine ADM, irrelevant of manufacturing method, and to determine if there is enough of an evidence base to change clinical practice. An extensive literature search was performed through MEDLINE and Embase with search terms defining a population, intervention and outcome. Title and abstract exclusion were performed with other exclusion criteria. In 191 articles were found after exclusion of duplicates, with only 29 remaining following exclusions. Ten studies were found to have level I and II evidence (I=3, II=8), of which two were histopathological, one was an animal model, one was a systematic review, and six were clinical. The remaining studies were reviewed and considered for discussion, but did not hold high enough standards for medical evidence. Strong clinical evidence already exists for the use of human ADM, but questions of access, cost, and ethics require consideration of a xenograft. Histopathologically, evidence suggests minimal long-term differences between human and porcine ADM, although there is a short acute immune response with porcine ADM. Clinically, there is limited difference in outcomes, with a small range in effect of different ADM preparations. Considering the effectiveness of ADM in wound healing, more high-level research with appropriate statistical analysis to facilitate a future meta-analysis is recommended to justify a transition from human to porcine ADM.

Jo Jeongsan in Context: "Second Founders" in New Religious Movements

  • INTROVIGNE, Massimo
    • Journal of Daesoon Thought and the Religions of East Asia
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    • v.1 no.1
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    • pp.17-37
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    • 2021
  • Scholars of new religious movements have emphasized the role of "second founders," such as Judge J.F. Rutherford for the Jehovah's Witnesses, Brigham Young for the Mormons, or Deguchi Onisaburo for Oomoto. They systematize and structure movements often created by the "first founders" with a minimal organization only. The paper argues that the model for the sequence first founder/second founder described by these scholars is the relationship between Jesus and Paul of Tarsus at the origins of Christianity. It proposes a comparison between Jesus of Nazareth and Kang Jeungsan, who established the tradition leading to present-day Daesoon Jinrihoe. It then summarizes the biography of Jo Jeongsan, recognized by Daesoon Jinrihoe as its "second founder" within the same tradition, and discusses the analogies between his connection to the "first founder," Kang Jeungsan, and the connection Paul of Tarsus established with Jesus Christ. The paper considers recent scholarship about Paul, often described as the "New Perspective on Pauline Scholarship." Paul never personally met Jesus Christ, except after the latter's death through a spiritual revelation, just as Jo Jeongsan never met Kang Jeungsan, except after his death, when he manifested himself to him in spirit. Nonetheless, Paul was able to decisively shape the largest branch among the followers of Jesus Christ, just as Jo Jeongsan originated the lineage leading to Daesoon Jinrihoe, currently the largest religious order among those recognizing Kang Jeungsan as the incarnated Supreme God.

Free vibration and buckling analyses of curved plate frames using finite element method

  • Oguzhan Das;Hasan Ozturk;Can Gonenli
    • Structural Engineering and Mechanics
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    • v.86 no.6
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    • pp.765-778
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    • 2023
  • This study investigates the free vibration and buckling analyses of isotropic curved plate structures fixed at all ends. The Kirchhoff-Love Plate Theory (KLPT) and Finite Element Method (FEM) are employed to model the curved structure. In order to perform the finite element analysis, a four-node quadrilateral element with 5 degrees of freedom (DOF) at each node is utilized. Additionally, the drilling effect (θz) is considered as minimal to satisfy the DOF of the structure. Lagrange's equation of motion is used in order to obtain the first ten natural frequencies and the critical buckling values of the structure. The effects of various radii of curvatures and aspect ratio on the natural frequency and critical buckling load values for the single-bay and two-bay curved frames are investigated within this scope. A computer code based on finite element analysis is developed to perform free vibration and buckling analysis of curved plate frames. The natural frequency and critical buckling load values of the present study are compared with ANSYS R18.2 results. It has been concluded that the results of the present study are in good agreement with ANSYS results for different radii of curvatures and aspect ratio values of both single-bay and two-bay structures.

Assessment of maximum liquefaction distance using soft computing approaches

  • Kishan Kumar;Pijush Samui;Shiva S. Choudhary
    • Geomechanics and Engineering
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    • v.37 no.4
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    • pp.395-418
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    • 2024
  • The epicentral region of earthquakes is typically where liquefaction-related damage takes place. To determine the maximum distance, such as maximum epicentral distance (Re), maximum fault distance (Rf), or maximum hypocentral distance (Rh), at which an earthquake can inflict damage, given its magnitude, this study, using a recently updated global liquefaction database, multiple ML models are built to predict the limiting distances (Re, Rf, or Rh) required for an earthquake of a given magnitude to cause damage. Four machine learning models LSTM (Long Short-Term Memory), BiLSTM (Bidirectional Long Short-Term Memory), CNN (Convolutional Neural Network), and XGB (Extreme Gradient Boosting) are developed using the Python programming language. All four proposed ML models performed better than empirical models for limiting distance assessment. Among these models, the XGB model outperformed all the models. In order to determine how well the suggested models can predict limiting distances, a number of statistical parameters have been studied. To compare the accuracy of the proposed models, rank analysis, error matrix, and Taylor diagram have been developed. The ML models proposed in this paper are more robust than other current models and may be used to assess the minimal energy of a liquefaction disaster caused by an earthquake or to estimate the maximum distance of a liquefied site provided an earthquake in rapid disaster mapping.

Generation and Detection of Cranial Landmark

  • Heo, Suwoong;Kang, Jiwoo;Kim, Yong Oock;Lee, Sanghoon
    • Journal of International Society for Simulation Surgery
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    • v.2 no.1
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    • pp.26-32
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    • 2015
  • Purpose When a surgeon examines the morphology of skull of patient, locations of craniometric landmarks of 3D computed tomography(CT) volume are one of the most important information for surgical purpose. The locations of craniometric landmarks can be found manually by surgeon from the 3D rendered volume or 2D sagittal, axial, and coronal slices which are taken by CT. Since there are many landmarks on the skull, finding these manually is time-consuming, exhaustive, and occasionally inexact. These inefficiencies raise a demand for a automatic localization technique for craniometric landmark points. So in this paper, we propose a novel method through which we can automatically find these landmark points, which are useful for surgical purpose. Materials and Methods At first, we align the experimental data (CT volumes) using Frankfurt Horizontal Plane (FHP) and Mid Sagittal Plane(MSP) which are defined by 3 and 2 cranial landmark points each. The target landmark of our experiment is the anterior nasal spine. Prior to constructing a statistical cubic model which would be used for detecting the location of the landmark from a given CT volume, reference points for the anterior nasal spine were manually chosen by a surgeon from several CT volume sets. The statistical cubic model is constructed by calculating weighted intensity means of these CT sets around the reference points. By finding the location where similarity function (squared difference function) has the minimal value with this model, the location of the landmark can be found from any given CT volume. Results In this paper, we used 5 CT volumes to construct the statistical cubic model. The 20 CT volumes including the volumes, which were used to construct the model, were used for testing. The range of age of subjects is up to 2 years (24 months) old. The found points of each data are almost close to the reference point which were manually chosen by surgeon. Also it has been seen that the similarity function always has the global minimum at the detection point. Conclusion Through the experiment, we have seen the proposed method shows the outstanding performance in searching the landmark point. This algorithm would make surgeons efficiently work with morphological informations of skull. We also expect the potential of our algorithm for searching the anatomic landmarks not only cranial landmarks.

Predicting Road Surface Temperature using Solar Radiation Data from SOLWEIG(SOlar and LongWave Environmental Irradiance Geometry-model): Focused on Naebu Expressway in Seoul (태양복사모델(SOLWEIG)의 복사플럭스 자료를 활용한 노면온도 예측: 서울시 내부순환로 대상)

  • AHN, Suk-Hee;KWON, Hyuk-Gi;YANG, Ho-Jin;LEE, Geun-Hee;YI, Chae-Yeon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.4
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    • pp.156-172
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    • 2020
  • The purpose of this study was to predict road surface temperature using high-resolution solar radiation data. The road surface temperature prediction model (RSTPM) was applied to predict road surface temperature; this model was developed based on the heat-balance method. In addition, using SOLWEIG (SOlar and LongWave Environmental Irradiance Geometry-model), the shadow patterns caused by the terrain effects were analyzed, and high-resolution solar radiation data with 10 m spatial resolution were calculated. To increase the accuracy of the shadow patterns and solar radiation, the day that was modeled had minimal effects from fog, clouds, and precipitation. As a result, shadow areas lasted for a long time at the entrance and exit of a tunnel, and in a high-altitude area. Furthermore, solar radiation clearly decreased in areas affected by shadows, which was reflected in the predicted road surface temperatures. It was confirmed that the road surface temperature should be high at topographically open points and relatively low at higher altitude points. The results of this study could be used to forecast the freezing of sections of road surfaces in winter, and to inform decision making by road managers and drivers.

The Dutch RE;MIND Design's Conceptual and Critical Aesthetics of Use (네덜란드 RE;MIND 디자인의 개념적·비평적 사용미학)

  • Park, Young-Tae
    • Korean Institute of Interior Design Journal
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    • v.23 no.2
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    • pp.51-61
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    • 2014
  • Aesthetics of use for modern people can be regarded as being weighted toward universal and rational function since it has focused on an 'automation and efficiency' and 'smartness' in terms of technological and human engineering position. Thus, aesthetics of use as an individual agent has remained in minimal level. This study attempts to seek conceptual model of design regarding the behavior of users from the systematization of critical theories about the usability. To do that, 'HERTZAIN TALES' written by Anthony Dune and the concept and system of Droog Design have been used as a core standard. In line with the various experiments by artist groups such as Fluxus, Memphis group and the work of product semantics, and inherent characteristics of Droog design, which has surfaced from the 1990s, concepts that has mentioned in the Hertzain tales have been organized into main texts. By overcoming cognitive bias inherent in the material culture and by overcoming an existing usability based on immateriality and dialectic solution, the autonomy of critical design and instrumentality of Droog design have been systemized. By interpreting the design aspect of 12 pieces that have been submitted to the RE;MIND section, the core of this study, it has been confirmed that conceptual and critical design's aesthetics of use From the interpretation of the design aspect of 12 pieces that have been submitted to the RE;MIND section, the core of this study, it has been confirmed that conceptual and critical design's aesthetics of use has established the autonomy and independence of the behavior of users, created functional articulation of materials and secured new conceptual model and thus, could be an effective methodical clue for creating an emergent design.

A Study on the Optimal Method for recycling the Waste Electronics' Reverse Logistics (폐전자제품 회수물류 최적화 연구)

  • Lee, Seok Kee;Roh, Jae-Whak;Cho, Yeong Bin
    • International Commerce and Information Review
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    • v.16 no.4
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    • pp.171-190
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    • 2014
  • A short consumption cycle caused by the technological development and the diversification of customer lead to both the dynamic growth of the industry and the waste recycling issue at the same time. Including Korea, the situation is particularly worrisome in some countries, such as India and China, where acute environmental hazards have resulted from a combination of a lack of recycling centers' capacity and the domination of a large backyard recycling sector. A study about to maximize the current recycling center efficiency with minimal changes is required. In this study, we suggest the optimal location selection method for the recycling center based on the well-known reverse logistics cost minimization model. An actual recycling data about a specific electronic equipment and region in Korea are used for the verification of the method suggested.

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Evaluation of Water Retentive Pavement as Mitigation Strategy for Urban Heat Island Using Computational Fluid Dynamics

  • Cortes, Aiza;Shimadera, Hikari;Matsuo, Tomohito;Kondo, Akira
    • Asian Journal of Atmospheric Environment
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    • v.10 no.4
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    • pp.179-189
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    • 2016
  • Here we evaluated the effect of using water retentive pavement or WRP made from fly ash as material for main street in a real city block. We coupled computational fluid dynamics and pavement transport (CFD-PT) model to examine energy balance in the building canopies and ground surface. Two cases of 24 h unsteady analysis were simulated: case 1 where asphalt was used as the pavement material of all ground surfaces and case 2 where WRP was used as main street material. We aim to (1) predict diurnal variation in air temperature, wind speed, ground surface temperature and water content; and (2) compare ground surface energy fluxes. Using the coupled CFD-PT model it was proven that WRP as pavement material for main street can cause a decrease in ground surface temperature. The most significant decrease occurred at 1200 JST when solar radiation was most intense, surface temperature decreased by $13.8^{\circ}C$. This surface temperature decrease also led to cooling of air temperature at 1.5 m above street surface. During this time, air temperature in case 2 decreased by $0.28^{\circ}C$. As the radiation weakens from 1600 JST to 2000 JST, evaporative cooling had also been minimal. Shadow effect, higher albedo and lower thermal conductivity of WRP also contributed to surface temperature decrease. The cooling of ground surface eventually led to air temperature decrease. The degree of air temperature decrease was proportional to the surface temperature decrease. In terms of energy balance, WRP caused a maximum increase in latent heat flux by up to $255W/m^2$ and a decrease in sensible heat flux by up to $465W/m^2$.