• Title/Summary/Keyword: Incremental Development

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Chemical Characterisation of Organic Functional Group Compositions in PM2.5 Collected at Nine Administrative Provinces in Northern Thailand during the Haze Episode in 2013

  • Pongpiachan, Siwatt;Choochuay, Chomsri;Chonchalar, Jittiphan;Kanchai, Panatda;Phonpiboon, Tidarat;Wongsuesat, Sornsawan;Chomkhae, Kanokwan;Kittikoon, Itthipon;Hiranyatrakul, Phoosak;Cao, Junji;Thamrongthanyawong, Sombat
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3653-3661
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    • 2013
  • Along with rapid economic growth and enhanced agricultural productivity, particulate matter emissions in the northern cities of Thailand have been increasing for the past two decades. This trend is expected to continue in the coming decade. Emissions of particulate matter have brought about a series of public health concerns, particularly chronic respiratory diseases. It is well known that lung cancer incidence among northern Thai women is one of the highest in Asia (an annual age-adjusted incidence rate of 37.4 per 100,000). This fact has aroused serious concern among the public and the government and has drawn much attention and interest from the scientific community. To investigate the potential causes of this relatively high lung cancer incidence, this study employed Fourier transform infrared spectroscopy (FTIR) transmission spectroscopy to identify the chemical composition of the $PM_{2.5}$ collected using Quartz Fibre Filters (QFFs) coupled with MiniVol$^{TM}$ portable air samplers (Airmetrics). $PM_{2.5}$ samples collected in nine administrative provinces in northern Thailand before and after the "Haze Episode" in 2013 were categorised based on three-dimensional plots of a principal component analysis (PCA) with Varimax rotation. In addition, the incremental lifetime exposure to $PM_{2.5}$ of both genders was calculated, and the first derivative of the FTIR spectrum of individual samples is here discussed.

Returning to Daily Life--Research on Chinese Community Construction under the Background of Urban Renewal

  • Lu Ziyan;Lee Jaewoo
    • International Journal of Advanced Culture Technology
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    • v.11 no.3
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    • pp.231-235
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    • 2023
  • Currently, China's urban landscape is undergoing a gradual shift from incremental development to stock renovation. Furthermore, the planning and development objectives of urban communities have evolved from solely focusing on physical space construction to promoting sustainable development within a humanistic society. The current approach to community planning and construction, which emphasizes a singular dimension of residential life, overlooks the multifaceted aspects of community life and production. This oversight leads to a lack of attention to interpersonal relationships within the community, difficulties in establishing a connection between people and their environment, and numerous other issues. Consequently, this paper seeks to redefine the concept of sociality within community spaces by considering the continuum of time and space within communities. It aims to delineate the roles of "power" and "rights" within the community context, with a particular focus on everyday life, in order to reevaluate strategies and methods for fostering dynamic community development.

Development of Mandrel Forging Process for Large Conical Aluminum Shell (대형 원뿔형 알루미늄 실린더의 멘드렐 단조 공정 개발)

  • Nam, J.W.;Cho, J.R.;Lee, K.H.;Lee, I.H.
    • Transactions of Materials Processing
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    • v.27 no.5
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    • pp.276-280
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    • 2018
  • This paper has developed a forging process for conical shells for making aluminum cylindrical large shells. An incremental forging process was applied to reduce forging loads and die cost. The preform is designed based on the crosssectional area of the final forged shape. Inner diameter of the preform for mandrel forging is constant, and outer diameter is conical so that it matches the cross-sectional area of the product. However, simulation confirmed that the larger diameter is smaller than predicted and the length is larger than predicted because in the initial stage of forging, the large diameter portion first comes into contact with the anvil at the initial stage of forging and stretches in longitudinal direction. So, it has developed a rule to design the preform considering 3-D deformation instead of plane strain deformation at the beginning stage of mandrel forging. The developed mandrel forging process can be applied to more similar products and economic benefits may be obtained.

Experimental Study on the Development of a Forming Process for Manufacturing Doubly-curved Sheet Metal (이중 곡률을 갖는 판재의 성형 공정의 개발에 대한 실험적 연구)

  • 양동열
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03b
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    • pp.18-21
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    • 1999
  • In this study in order to make doubly-curved sheet metal effectively a sheet metal forming process has been developed by adopting the flexibility of the incremental forming process and the principle of bending deformation which causes slight deformation to thickness The developed process is an unconstrained forming process with no holder. For this study the experimental equipment is set up with the punch-set which consists of two pairs of lower support-punches and one upper center-punch. In the experiments using aluminum sheet it is found that the curvature of the formed sheet metal is determined by controlling the distance between supporting punches in pairs and the forming depth of the center-punch. and the edge-forming method is proposed for forming the sheet metal into the balanced shape. The equation using process variables such as the distance between supporting punches in pairs and the forming depth of the center-punch is proposed for the prediction of the radii of curvatures of the formed shape and it is corrected by the experimental results and the FEM simulation results about whether springback takes place. It is found that according o the simulation there is a certain set of the distance between a pair of supporting punches and the forming depth of the center-punch which causes a little springback. It is thus shown that the radii of curvatures of the formed sheet metal can be predicated by the corrected equation unless significant springback occurs.

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Prototyping the Brake Shields of a Vehicle by Dieless CNC Forming Technology (다이레스 CNC 포밍을 이용한 자동차용 브레이크 더스트 쉴드 시작품 제작)

  • Lee H.J.;Kang S.H.;Yeom K.S.;Gang Byeong-Su;Wang D.H.;Kang J.K.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.529-530
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    • 2006
  • Manufacturing industry is changing rapidly. Prototyping with rapid manufacturing is a part of every business in many companies and prototypes are used efficiently as a part of the production development process. Sheet metal forming has traditionally been a technology area where prototyping has been extremely expensive and efficient options for low volume have been limited. This paper describes the process for incremental sheet forming technologies to make the prototype for a brake dust shield of vehicles, which includes the remodeling method to make a base mold and tool path for sheet metal forming and 5-axes laser cutting machine to trim the prototype product.

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Seismic fragility analysis of sliding artifacts in nonlinear artifact-showcase-museum systems

  • Liu, Pei;Li, Zhi-Hao;Yang, Wei-Guo
    • Structural Engineering and Mechanics
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    • v.78 no.3
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    • pp.333-350
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    • 2021
  • Motivated by the demand of seismic protection of museum collections and development of performance-based seismic design guidelines, this paper investigates the seismic fragility of sliding artifacts based on incremental dynamic analysis and three-dimensional finite element model of the artifact-showcase-museum system considering nonlinear behavior of the structure and contact interfaces. Different intensity measures (IMs) for seismic fragility assessment of sliding artifacts are compared. The fragility curves of the sliding artifacts in both freestanding and restrained showcases placed on different floors of a four-story reinforced concrete frame structure are developed. The seismic sliding fragility of the artifacts within a real-world museum subjected to bi-directional horizontal ground motions is also assessed using the proposed IM and engineering demand parameter. Results show that the peak floor acceleration including only values initiating sliding is an efficient IM. Moreover, the sliding fragility estimate for the artifact in the restrained showcase increases as the floor level goes higher, while it may not be true in the freestanding showcase. Furthermore, the artifact is more prone to sliding failure in the restrained showcase than the freestanding showcase. In addition, the artifact has slightly worse sliding performance subjected to bi-directional motions than major-component motions.

Development of Contact Algorithms for Three Dimensional Surfaces (삼차원 곡면에 대한 접촉해석기법의 개발)

  • 박채현;박종진
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1994.10a
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    • pp.157-164
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    • 1994
  • Finite element analysis of material deformation is successfully utilized to understand metal forming processes such as forging, extrusion and deep drawing. However, such analysis involves contact problems; a free node touches a die surface and a contact node slips along the die surface. In the present investigation, appropriate contact algorithms were developed assuming that a three dimensional surface can be divided into bilinear patches and that nodal velocities are linear during an incremental time. The algorithms were coded into a computer program and tested for a simple surface. Comparison of the test result with that obtained from a commercial code is presented and discussed.

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National Embeddedness of Economic Activities: Industrial and Technology Policy in Korea and Taiwan

  • Gammeltoft, Peter;Sornn-Friese, Henrik
    • Journal of Technology Innovation
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    • v.13 no.2
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    • pp.1-22
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    • 2005
  • This paper adopts an embeddedness perspective and discusses rationales for government intervention in relation to economic development. Looking at East Asian experiences with industrial and technology policy the paper examines the general requirements, specific areas of focus and appropriate techniques for industrial and technology policy. Eight generic policy requirements are identified, viz. government capacity; monitoring and adjustment; policy sequencing; incremental upgrading; progressive market reliance; performance-orientation; selectivity; and flexibility.

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Development of Delaunay Triangulation Algorithm Using Subdivision (분할 Delaunay 삼각화 알고리즘 개발)

  • 박시형;이성수
    • Korean Journal of Computational Design and Engineering
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    • v.7 no.4
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    • pp.248-253
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    • 2002
  • Delaunay triangulation is well balanced in the sense that the triangles tend toward equiangularity. And so, Delaunay triangulation hasn't some slivers triangle. It's commonly used in various field of CAD applications, such as reverse engineering, shape reconstruction, solid modeling and volume rendering. For Example, In this paper, an improved Delaunay triangulation is proposed in 2-dimensions. The suggested algorithm subdivides a uniform grids into sub-quad grids, and so efficient where points are nonuniform distribution. To get the mate from quad-subdivision algorithm, the area where triangulation-patch will be most likely created should be searched first.

The Development and Application of KOESWall System (분리형 보강토 옹벽의 개발 및 적용사례)

  • 김영윤
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.10a
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    • pp.323-328
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    • 2001
  • In the ordinary reinforced earth wall, which was constructed by incremental construction method, the horizontal deformation of the facing due to the compaction induced horizontal earth pressure was unavoidable. Thus the KOESWall system which are adopted the isolated construction method was developed by I&S Eng. Co., Ltd. in 1999. Due to its systematical feature, KOESWall system is able to minimizes the horizontal deformation of reinforced wall effectively and it can be used as temporary structures more economically without the lacing block. In this report, it is shown that the concept and case histories of KOESWall system as a retaining structures.

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