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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The study of ��������Sm through the beta decay of ��������Pm, ��������[superscript m]Eu and ��������[superscipt g]Eu

Schmelzenbach, Paul D. 24 April 2003 (has links)
The N=88 isotones lie on the onset of nuclear deformation and have a complicated nuclear structure. To better understand this region, the nuclear levels of ��������Sm were studied in three different �� decay experiments. De-populating ��-rays were measured using the 8�� spectrometer, an array of 20 Compton suppressed Ge detectors. Levels of ��������Sm were populated in varying degrees by three radioactive sources: ��������Pm (J=1���, Q=3454 keV), ��������[superscript m]Eu (J=0���, Q=2303 keV), and ��������[superscipt g]Eu (J=5���, Q=2261 keV), which were all produced at the 88" cyclotron located at LBNL. Among several changes to the existing level structure were the addition of a 0��� level identified at 1603.24 keV, as well as confirming another questioned 0��� assignment of the 1786.47 keV level. Angular correlation analysis was carried out on many different transitions, allowing for spin assignments and the determination of mixing ratios. The results from these three experiments provide extensive new data, and give a fairly complete picture of nuclear levels below about 2 MeV and J���6. The theoretical interpretation of this particular nucleus is still open to question. The data from these experiments, used in conjunction with other studies of nuclei in this same mass region (which are currently underway), may provide further insight into this transition region. / Graduation date: 2003
22

Segmentation and Line Filling of 2D Shapes

Pérez Rocha, Ana Laura 21 January 2013 (has links)
The evolution of technology in the textile industry reached the design of embroidery patterns for machine embroidery. In order to create quality designs the shapes to be embroidered need to be segmented into regions that define different parts. One of the objectives of our research is to develop a method to automatically segment the shapes and by doing so making the process faster and easier. Shape analysis is necessary to find a suitable method for this purpose. It includes the study of different ways to represent shapes. In this thesis we focus on shape representation through its skeleton. We make use of a shape's skeleton and the shape's boundary through the so-called feature transform to decide how to segment a shape and where to place the segment boundaries. The direction of stitches is another important specification in an embroidery design. We develop a technique to select the stitch orientation by defining direction lines using the skeleton curves and information from the boundary. We compute the intersections of segment boundaries and direction lines with the shape boundary for the final definition of the direction line segments. We demonstrate that our shape segmentation technique and the automatic placement of direction lines produce sufficient constrains for automated embroidery designs. We show examples for lettering, basic shapes, as well as simple and complex logos.
23

Investigation of Shapes and Colours as Elements of Character Design

Fogelström, Elise January 2013 (has links)
Character design is applied widely both in the game and movie industry. For character designers, it is essential to design intuitively and to avoid repeated and unfulfilling designs. To understand certain methodologies used in design, this degree project investigates if there are further limitations or considerations that need more attention when designing purposeful characters. To get an overview if culture, age and gender affect the choice of shapes and colour schemes of characters, as a method, the online survey was used providing results based on answers from 72 participants.
24

GENERATING RANDOM SHAPES FOR MONTE CARLO ACCURACY TESTING OF PAIRWISE COMPARISONS

Almowanes, Abdullah 08 October 2013 (has links)
This thesis shows highly encouraging results as the gain of accuracy reached 18.4% when the pairwise comparisons method was used instead of the direct method for comparing random shapes. The thesis describes a heuristic for generating random but nice shapes, called placated shapes. Random, but visually nice shapes, are often needed for cognitive experiments and processes. These shapes are produced by applying the Gaussian blur to randomly generated polygons. Afterwards, the threshold is set to transform pixels to black and white from di erent shades of gray. This transformation produces placated shapes for easier estimation of areas. Randomly generated placated shapes are used to perform the Monte Carlo method to test the accuracy of cognitive processes by using pairwise comparisons. An on-line questionnaire has been implemented and participants were asked to estimate the areas of ve shapes using a provided unit of measure. They were also asked to compare the shapes in pairs. Such Monte Carlo experiment has never been conducted for 2D case. The received results are of considerable importance.
25

MODAL ANALYSIS OF MEMS GYROSCOPIC SENSORS

Burnie, Marc 03 June 2010 (has links)
Microgyroscopes find popular applications in modern life, such as, vehicle navigation, inertial positioning, human body motion monitoring, etc. In this study, three unique MEMS gyroscopic sensors were investigated using experimental methods and finite element analysis (FEA) modelling, particularly their modal behaviour. The analytical, simulated and experimental results were compared and the discrepancy between resonant frequencies of the significant mode shapes was discussed. Three microfabricated gyroscopes were investigated: a thermally-actuated in-plane gyroscope, an electrostatically-actuated in-plane gyroscope and an electrostatically-actuated out-of-plane gyroscope. Numerical finite element modal analysis for these three gyroscopes was conducted using COMSOL Multiphysics. The experimental testing was conducted using a microsystem analyzer (MSA-400 PolyTec) with an integrated laser vibrometer. The simulation models predicted that the frequencies for driving and sensing modes were 4.948kHz and 5.459kHz for a thermally-actuated gyroscope, which agreed well with experimentally determined results of 5.98kHz and 6.0kHz respectively. The power requirements of a thermally-actuated gyroscope were 363.39mW to elicit a maximum peak-to-peak displacement of 4.2μm during dynamic operation. Similarly, the simulated frequencies for the driving and sensing modes were 1.170kHz and 1.644kHz for an electrostatically-actuated in-plane gyroscope, which corresponded to experimentally determined resonant frequencies 1.6kHz and 1.9kHz. Simulation for the electrostatically-actuated out-of-plane gyroscope was conducted and the frequencies for the driving and sensing modes were found to be 2.159kHz and 3.298kHz. Due to some fabrication defects, the experimental testing for this microgyroscope was not successful. Some recommendations to improve the design were provided for the future work. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-06-02 22:00:52.994
26

單向流風速控制對落塵分布改進之研討 / An investigation for the improvement of particle distribution by wind speed control in a unidirectional flow

劉晏, Yan Liu January 1996 (has links)
本研究希望在市面上常見的潔淨操作檯做迅速、有效的診斷及改進措施。為了實際了解氣流速率大小及分佈情況對塵粒數的影響,需作風速、塵粒數及壓力量測。將潔淨操作檯有效的工作空間分成三層,每層細分15個點位,共計45個量測點。在一般條件下運轉潔淨檯,量測45點位之風速值;之後僅抽換不同形狀之孔洞底板,原底板之孔洞為長條型,實驗加入之形狀為六角形及圓形,並一一重新量測前述各值。考慮到潔淨操作檯後方的流線並不圓滑,遂於其直角轉折處崁加金屬圓滑鈑,加強後方氣流流線之圓滑度,再一一重新量測前述各值重新量測。試驗結果顯示將底板孔洞形狀替換成圓形,潔淨操作檯最常使用的A層穩定度提升了4%,落塵量降低了89%。 / A popular clean bench used in Taiwan will be investigated and improved in a simple and economic way. The working space of the clean bench will be cut in three layers horizontally. There are nine points in a layer uniformly, in other words, there are 45 points in a working space to be measured for airflow speed. Then, to modulate the different airflow streams, different hole shapes and distributions on the bottom plate will be run in a series experiments. The route of the air flow back in the clean bench is existed a right angle, therefore, two smoothing metal plates will also be considered. Test result shows that circular hole is the best one of these experienced hole shapes, and it will increase the stability 4%, decrease the particle 89% in the layer A. / 摘 要 ii ABSTRACT iii 致 謝 iv 目 錄 v 表目錄 ix 圖目錄 xi 第一章 緒 論 1 1.1 研究動機 1 1.2 研究目的 2 1.3 研究方法 2 1.4 文獻回顧 3 1.5 章節內容 4 第二章 潔淨室的原理 5 2.1 潔淨室的起源 5 2.2 潔淨室的需求 6 2.3 潔淨室與氣流關係 7 2.4 無塵分類的規範 7 2.5 潔淨室標準的基礎 8 2.6 國際標準ISO 14644-1規定 9 第三章 實驗設置與研究方法 12 3.1垂直單向流潔淨操作台 12 3.1.1使用過程 13 3.2量測儀器 13 3.3多功能量測儀 14 3.3.1多功能量測儀按鍵 15 3.3.2多功能量測儀功能 16 3.3.3使用說明 17 3.4風速感應器 20 3.4.1風速感應器功能 20 3.4.2使用方法 21 3.4.3風速感應器圖片參考 21 3.5 落塵計 21 3.5.1 落塵計功能 22 3.5.2 落塵計過濾原理 23 3.5.3 落塵計特點 23 3.5.4 落塵計優點 24 3.5.5 落塵計按鍵 25 3.5.6 使用方法 26 3.6 實驗方法 26 3.6.1 儀器設備 26 3.6.2 量測內容 27 3.6.3 量測步驟 27 3.6.4 執行成果 29 3.6.5 孔洞率 30 3.6.6 改善孔洞率 30 第四章 實驗結果與分析討論 32 4.1內部氣流轉彎處未加圓滑金屬片的實驗數據 32 4.1.1長條狀金屬底板 32 4.1.2六角狀金屬底板 34 4.1.3圓孔狀金屬底板 36 4.2內部氣流轉彎處加圓滑金屬片的實驗數據 39 4.2.1長條狀金屬底板 39 4.2.2六角狀金屬底板 40 4.2.3圓孔狀金屬底板 42 4.3改進前綜合討論 45 4.4新圓型孔洞底板對風速及落塵之影響 50 4.5潔淨操作檯各層各點位各種試驗條件之紊流強度 54 4.5.1A層各點位各種試驗條件之紊流強度 54 4.5.2B層各點位各種試驗條件之紊流強度 55 4.5.3C層各點位各種試驗條件之紊流強度 56 4.6各條件之特性分析與討論 57 4.6.1潔淨操作檯試驗段8條件下各層平均風速 57 4.6.2潔淨操作檯8種試驗條件下三層之平均紊流強度 57 4.6.3潔淨操作檯8種試驗條件下三層之均勻度 58 4.6.4八種試驗條件下各層之穩定度及均勻度之平均值 59 4.7潔淨操作檯各層各點位各種試驗條件之穩定度及均勻度 60 4.7.1穩定度和均勻度對A層面的影響 60 4.7.2穩定度和均勻度對B層面的影響 62 4.7.3穩定度和均勻度對C層面的影響 64 4.7.4 綜合討論 65 第五章結論與建議 70 5.1 結 論 70 5.2 建 議 72 參考文獻 74
27

Segmentation and Line Filling of 2D Shapes

Pérez Rocha, Ana Laura 21 January 2013 (has links)
The evolution of technology in the textile industry reached the design of embroidery patterns for machine embroidery. In order to create quality designs the shapes to be embroidered need to be segmented into regions that define different parts. One of the objectives of our research is to develop a method to automatically segment the shapes and by doing so making the process faster and easier. Shape analysis is necessary to find a suitable method for this purpose. It includes the study of different ways to represent shapes. In this thesis we focus on shape representation through its skeleton. We make use of a shape's skeleton and the shape's boundary through the so-called feature transform to decide how to segment a shape and where to place the segment boundaries. The direction of stitches is another important specification in an embroidery design. We develop a technique to select the stitch orientation by defining direction lines using the skeleton curves and information from the boundary. We compute the intersections of segment boundaries and direction lines with the shape boundary for the final definition of the direction line segments. We demonstrate that our shape segmentation technique and the automatic placement of direction lines produce sufficient constrains for automated embroidery designs. We show examples for lettering, basic shapes, as well as simple and complex logos.
28

Lifetimes of superdeformed states in ³⁸Ar

Austin, Roby. Waddington, J. C. January 1900 (has links)
Thesis (Ph.D.)--McMaster University, 2004. / Supervisor: J.C. Waddington. Includes bibliographical references (leaves 130-137).
29

Structure of superdeformed bands near the N = 80 shell gap.

Hackman, Gregory Stephen. Waddington, J.C. Unknown Date (has links)
Thesis (Ph.D.)--McMaster University (Canada), 1996. / Source: Dissertation Abstracts International, Volume: 57-10, Section: B, page: 6339. Adviser: J. C. Waddinton.
30

Shapester's magic alphabet exegesis [thesis] submission to Auckland University of Technology as partial fulfilment of the degree of Master of Art and Design, March 2003.

Austin, Logan. January 2003 (has links) (PDF)
Thesis (MA--Art and Design) -- Auckland University of Technology, 2003. / On cover : 2004 Also held in print (37 leaves : col. ill. ; 30 cm. + CD-ROM) in Wellesley Theses Collection (T 709.93074 AUS)

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