• Title/Summary/Keyword: three-dimensional integration

Search Result 282, Processing Time 0.03 seconds

The Ebb and Flow of Regional Integration Vision in Asia-Pacific: From a Lens of Leaders' Declarations over 30 Years

  • Jeongmeen Suh
    • East Asian Economic Review
    • /
    • v.27 no.4
    • /
    • pp.303-325
    • /
    • 2023
  • This paper examines how APEC has transformed itself into an international forum for the vision of regional integration. It aims to quantify the documentation produced by the international organization and provide quantifiable evidence that aligns with prior knowledge rather than relying solely on intuition. For this purpose, I use various text mining techniques to extract multi-dimensional features from the text of APEC Leaders' Declarations from 1993 to 2023. In terms of interest and expectations for APEC as a forum, it is found that members have experienced two major peaks and troughs over the last three decades. It is found that the change point coincides with the Asian financial crisis of 1997 and the tensions between the United States and China since 2017. To explore more various aspects of economic integration in the Asia-Pacific region, this study also considers how consistently APEC has been an international forum for addressing issues, which members are active, and how members have clustered based on their views of APEC.

A Study on the Reappraisal of Gerrit Thomas Rietveld's Design Concept (게리트 리트벨트 디자인 개념 재평가에 관한 연구)

  • Lee, Kwang-In
    • Journal of The Korean Digital Architecture Interior Association
    • /
    • v.12 no.4
    • /
    • pp.97-105
    • /
    • 2012
  • This study aims to evaluate Rietveld's creative design style and concepts. To this end, I looked into the evaluation of major researchers on Rietveld, classified all his works into four groups according to the design types and analyzed them. As follows: based on the results of the analysis of works I concluded. First, Rietveld created the concept of the spatial extension to the ingenious joint which had the structural node formed of three listels with quadrangular section. It is the design innovation that led to liberate the closed construction. Second, Rietveld had opened up the possibility to neutralize the gravitational three-dimensional works. He subtracted the weight in the direction of gravity from the three-dimensional structure of the works and painted the three primary colors on them partially to get rid of the original material color. Therefore they looked like the forms liberated from gravity. Third, Rietveld ripped off the surfaces of cube through several formative experiments and decomposed the volume into the tesseract. Through this method of realizing the new plastic concepts, he completed the architectural models of weightlessness. Fourth, Rietveld opened the possibility of the realization of the three-dimensional works integrated all space and time in the one-pieced works and the folded works. Fifth, Rietveld steadily experimented and realized the internal and external integration of time and space in his later works.

Three-Dimensional Transition in the Wake of a Circular Cylinder By Direct Numerical Simulation (DNS에 의한 원주 후류에서의 3차원 천이)

  • Knag, S.J.;Tanahashi, M.;Miyauchi, T.;Mo, J.O.;Lee, Y.H.
    • Proceedings of the KSME Conference
    • /
    • 2001.11b
    • /
    • pp.570-577
    • /
    • 2001
  • Three-dimensional time-dependent flow past a circular cylinder is numerically investigated using direct numerical simulation for Reynolds number 280 and 300. The higher-order finite difference scheme is employed for the spatial distributions along with the second order Adams-Bashforth and the first order backward-Euler time integration. In x-y plane, the convection term is applied by the 5th order upwind scheme and the pressure and viscosity terms are applied by the 4th order central difference. And in spanwise, Navier-Stokes equation is distributed using of Spectral Method. At Reynolds number 259 the two-dimensional wake becomes linearly unstable to a second branch of modes with wavelength about 1.0 diameters at onset (B-mode). Present results of three-dimensional effects of in wake of a circular cylinder is represented with spanwise and streamwise vorticity contours as Reynolds numbers.

  • PDF

A Three-Dimensional Finite Element Model of Water Circulation (물의 순환에 관한 3차원 유한요소 모형)

  • 정태성
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.10 no.1
    • /
    • pp.27-36
    • /
    • 1998
  • A three-dimensional numerical model of water circulation has been developed. The model employs the equations on $\sigma$-coordinate and the finite element method for numerical integration. To verify accuracy of the model, a series of numerical experiments have been conducted. The experiments include wind-driven currents in an one-dimensional channel, wind-driven currents in a square lake, and tidal current distributions in Masan-Jinhae Bay. The simulation results showed good agreements with the analytic solutions for wind-driven current and the field data sets in Masan-Jinhae Bay. The model can be used widely for modeling of water circulation in the waters with a complex geometry.

  • PDF

Fretting fatigue life prediction for Design and Maintenance of Automated Manufacturing System (생산자동화 시스템의 설계 및 정비를 위한 프레팅 피로수명 예측)

  • Kim, Jin-Kwang
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.20 no.2
    • /
    • pp.195-204
    • /
    • 2017
  • Predicting the failure life of automated manufacturing systems can reduce overall downtime, maintenance costs, and total plant operation costs. Therefore, there is a growing interest in fatigue failure mechanisms as the safety or service life assessment of manufacturing systems becomes an important issue. In particular, fretting fatigue is caused by repeated tangential stresses that are generated by friction during small amplitude oscillatory movements or sliding between two surfaces pressed together in intimate contact. Previous studies in fretting fatigue have observed size effects related to contact width such that a critical contact width exists where there is drastic change in the fretting fatigue life. However, most of them are the two-dimensional finite element analyses based on the plane strain assumption. The purpose of this study is to investigate the contact size effects on the three-dimensional finite element model of a finite width of a flat specimen and a cylindrical pad exposed to fretting fatigue. The contact size effects were analyzed by means of the stress and strain averages at the element integration points of three-dimensional finite element model. This study shows that the fretting fatigue life of manufacturing systems can be predicted by three-dimensional finite element analysis based on SWT critical plane model.

Simulation Based Production Using 3-D CAD in Shipbuilding

  • Okumoto, Yasuhisa;Hiyoku, Kentaro;Uesugi, Noritaka
    • International Journal of CAD/CAM
    • /
    • v.6 no.1
    • /
    • pp.3-8
    • /
    • 2006
  • The application of three-dimensional (3-D) CAD has been popularized for design and production and digital manufacturing has been spreading in many industrial fields. By simulation of the production process using 3-D digital models, which are the core of CIM (Computer Integrated Manufacturing) system, the efficiency and safety of production are improved at each stage of work, and optimization of manufacturing can be achieved. This paper firstly describes the concept of "simulation based production" in shipbuilding and also digital manufacturing; the 3-D CAD system is indispensable for effective simulation because ship structure is three dimensionally complex. By simulation, "computer optimized manufacturing" can be possible. The most effective fields of simulation in shipbuilding are in jobs where many parties have to cooperate, while existing two-dimensional drawings are hardly observed the whole structures due to interference between structures or equipment of complex shape. In this paper some examples of the successful application in IHIMU (IHI Marine United Inc.) are shown: assembly of a pipe unit, erection of a complex hull block, carriage of equipment, installation of a propeller, and access in an engine room.

Clinical Application of Cardiac Hybrid Imaging in Coronary Artery Disease (관상동맥질환에서 심장 하이브리드 영상의 임상적 이용)

  • Gho, Ihn-Ho;Kong, Eun-Jung
    • Journal of Yeungnam Medical Science
    • /
    • v.26 no.1
    • /
    • pp.15-23
    • /
    • 2009
  • Constant technological developments in coronary artery disease have contributed to the assessment of both the presence of coronary stenosis and its hemodynamic consequences. Hence, noninvasive imaging helps guide therapeutic decisions by providing complementary information on coronary morphology and on myocardial perfusion and metabolism. This can he done using single photon emission computed tomography (SPECT) or positron emission tomography (PET) and multidetector CT (MDCT). Advances in image-processing software and the advent of SPECT/CT and PET/CT have paved the way for the combination of image datasets from different modalities, giving rise to hybrid imaging. Three dimensional cardiac hybrid imaging helped to confirm hemodynamic significance in many lesions, add new lesions such as left main coronay artery disease, exclude equivocal defects, correct the corresponding arteries to their allocated defects and identify culprit segment. Cardiac hybrid imaging avoids the mental integration of functional and morphologic images and facilitates a comprehensive interpretation of coronaty lesions and their pathophysiologic adequacy by three dimensional display of fused images, and allows the best evaluation of myocardial territories and the coronary-artery branches that serve each territory. This integration of functional and morphological information were feasible to intuitively convincing and might facilitate development of a comprehensive non-invasive assessment of coronary artery disease.

  • PDF

Issues on Monolithic 3D Integration Techniques for Realizing Next Generation Intelligent Devices (차세대 지능형 소자 구현을 위한 모노리식 3D 집적화 기술 이슈)

  • Moon, J.;Nam, S.;Joo, C.W.;Sung, C.;Kim, H.O.;Cho, S.H.;Park, C.W.
    • Electronics and Telecommunications Trends
    • /
    • v.36 no.3
    • /
    • pp.12-22
    • /
    • 2021
  • Since the technical realization of self-aligned planar complementary metal-oxide-semiconductor field-effect transistors in 1960s, semiconductor manufacturing has aggressively pursued scaling that fruitfully resulted in tremendous advancement in device performances and realization of features sizes smaller than 10 nm. Due to many intrinsic material and technical obstacles, continuing the scaling progress of semiconductor devices has become increasingly arduous. As an effort to circumvent the areal limit, stacking devices in a three-dimensional fashion has been suggested. This approach is commonly called monolithic three-dimensional (M3D) integration. In this work, we examined technical issues that need to be addressed and overcome to fully realize energy efficiency, short latency and cost competency. Full-fledged M3D technologies are expected to contribute to various new fields of artificial intelligence, autonomous gadgets and unknowns, which are to be discovered.

Three-dimensional geostatistical modeling of subsurface stratification and SPT-N Value at dam site in South Korea

  • Mingi Kim;Choong-Ki Chung;Joung-Woo Han;Han-Saem Kim
    • Geomechanics and Engineering
    • /
    • v.34 no.1
    • /
    • pp.29-41
    • /
    • 2023
  • The 3D geospatial modeling of geotechnical information can aid in understanding the geotechnical characteristic values of the continuous subsurface at construction sites. In this study, a geostatistical optimization model for the three-dimensional (3D) mapping of subsurface stratification and the SPT-N value based on a trial-and-error rule was developed and applied to a dam emergency spillway site in South Korea. Geospatial database development for a geotechnical investigation, reconstitution of the target grid volume, and detection of outliers in the borehole dataset were implemented prior to the 3D modeling. For the site-specific subsurface stratification of the engineering geo-layer, we developed an integration method for the borehole and geophysical survey datasets based on the geostatistical optimization procedure of ordinary kriging and sequential Gaussian simulation (SGS) by comparing their cross-validation-based prediction residuals. We also developed an optimization technique based on SGS for estimating the 3D geometry of the SPT-N value. This method involves quantitatively testing the reliability of SGS and selecting the realizations with a high estimation accuracy. Boring tests were performed for validation, and the proposed method yielded more accurate prediction results and reproduced the spatial distribution of geotechnical information more effectively than the conventional geostatistical approach.

Development of a Three-Dimensional Euler Solver for Analysis of Basic Contraction Flow (수축부 기초 유동 해석을 위한 삼차원 Euler 방정식 풀개 개발)

  • Kim J.;Kim H. T.
    • Journal of computational fluids engineering
    • /
    • v.2 no.1
    • /
    • pp.8-12
    • /
    • 1997
  • The three-dimensional Euler equations are solved numerically for the analysis of contraction flows in wind or water tunnels. A second-order finite difference method is used for the spatial discretization on the nonstaggered grid system and the 4-stage Runge-Kutta scheme for the numerical integration in time. In order to speed up the convergence, the local time stepping and the implicit residual-averaging schemes are introduced. The pressure field is obtained by solving the pressure-Poisson equation with the Neumann boundary condition. For the evaluation of the present Euler solver, numerical computations are carried out for three contraction geometries, one of which was adopted in the Large Cavitation Channel for the U.S. Navy. The comparison of the computational results with the available experimental data shows good agreement.

  • PDF