1,721,095 research outputs found
A Study on the Income Tax Rate Reduction and Earnings Management
No full text立法院於民國98年5月1日三讀通過修正所得稅法，將營利事業所得稅稅率自25%調降為20%，自99年度起適用。若管理階層希望降低稅務負擔，使公司價值最大化，此稅率調降之幅度可能給予管理階層十足的誘因去遞延盈餘。本研究欲探討管理階層是否因此而將98年度的部分盈餘遞延至較低稅率的年度。另外，以債務契約假說、政治力量假說等來設立變數，辨認與盈餘管理相關聯之因素。
本研究樣本之估計期間從85年至95年，測試期間為96年至98年。本研究採用Modified Jones Model 估計非裁量性流動應計數（ discretionary current accruals），自總流動應計數中扣除，得到裁量性流動應計數，本研究將其視為盈餘管理之代理變數，利用統計方法，驗證其與變數之關聯性，得到以下結論：
1. 管理階層可能在稅率調降前一年度（98年）向下管理盈餘，將該期盈餘遞延到較低稅率之年度。
2. 在稅率調降前一年度的裁量性流動應計數與債務比率呈正向關係。
3. 在稅率調降前一年度的裁量性流動應計數與公司規模呈正向關係。
4. 在稅率調降前一年度的裁量性流動應計數與管理階層持股比率呈負向關係。The Legislative Yuan of Republic of China changed Income Tax Act to reduce income tax rate from 25% to 20%, which became effective in 2010. Income tax rate reduction would have provided management with substantial incentives to defer income from 2009 to 2010, as a way to minimize tax costs. This study investigates whether earnings of 2009 were managed downwards in response to tax rate reduction, and to examine which type of firms are more likely to conduct earnings management.
The estimation period of the sample is from 1996 to 2006, and test period 2007 to 2009. Discretionary current accruals, which are estimated by Modified Jones Model, are used as a proxy for earnings management.
Based on empirical results, this study has four conclusions:
1. Managers tend to deliberately decrease 2009 earnings in order to minimize tax costs.
2. Discretionary current accruals in the year proceeding to tax rate reduction are positively related to debt levels.
3. Discretionary current accruals in the year proceeding to tax rate reduction are positively related to firm size.
4. Discretionary current accruals in the year proceeding to tax rate reduction are negatively related to levels of manager ownership
Equilibrium Configurations of a Long Rigid Rotor and Auto-Balancer System
No full text由於對工作效率的要求日增，各類機械裝置的轉速也隨之提升。然而在高轉速的情形下，即使微小的偏心質量也會造成過大的偏心振動，因此高速旋轉機具的平衡裝置越來越重要。在適當的條件下，滾珠型自動平衡裝置可以有效抑制偏心質量所產生的偏心振動，且已經成功應用於二維平面的轉子系統。然而，對於在三維長轉子偏心制振的研究相對較為缺乏。本論文探討剛性偏心長轉子於兩端面個別裝置滾珠平衡裝置之系統的平衡解，首先建構由滾珠型自動平衡裝置、剛性長轉子、偏心質量、等向性線性彈簧以及黏滯阻尼器所組成系統的理論模型，接著利用Lagrange方程式推導統御方程式。我們發現三維長轉子-自動平衡裝置系統共有16種平衡解。在某些特定條件下，可以得到其中幾種型式平衡解的解析解。至於一般情形下，則需仰賴數值解。我們詳細探討各個平衡解的存在區間及穩定性，展示各個平衡解下系統的振幅隨轉速變化的情形，並以實驗定性檢驗數值解的正確性。Due to the demand of higher and higher efficiency, the rotational speed of rotary machinery has been increased continually. At high rotational speeds, even a small amount of unbalance may induce significant vibrations. Therefore, precise balancing of high-speed rotors has become more and more important. The ball-type automatic balancer, under proper conditions, can suppress arbitrary amount of unbalance and has been successfully applied to two dimensional planar rotor systems. However, relatively few studies have been conducted on its application to three dimensional long rotor systems. This paper investigated equilibrium configurations of a long rigid rotor equipped with an automatic balancer on each end. The rotor was supported at each end by isotropic linear springs and viscous dampers. First, the mathematical model of the system consisting of the long rigid rotor, auto-balancers and the suspension was constructed. Second, the governing equations were derived by Lagrange''s equations and the equilibrium equations were presented. There are totally sixteen different types of equilibrium configurations. Under specific conditions, some equilibrium configurations can be determined analytically. However, in general, equilibrium configurations can only be determined numerically. We investigated the dependence of equilibrium configurations on system parameters comprehensively. For each equilibrium configuration, the variation of the vibration amplitude of the system with the rotational speed was studied in detail. The existence and stable rotational speed regions of the equilibrium configurations were identified. Finally experiments were conducted to verify the numerical results.致謝 i
口試委員審定書 ii
摘要 iii
Abstract iv
目錄 vi
圖目錄 viii
表目錄 xii
第 一 章 緒論 1
1-1 研究動機 1
1-2 參考文獻 2
1-3 論文架構 3
第 二 章 理論分析 4
2-1 三維偏心長轉子理論模型與運動方程式 4
2-2 平衡解 13
2-3 解析解及其穩定性 20
2-3-1 雙平面完全平衡解 20
2-3-2 靜態不平衡（static unbalance） 24
2-3-3 力偶不平衡（couple unbalance） 28
第 三 章數值分析 32
3-1 相位角為0 33
3-1-1 雙平面完全制振 33
3-1-2 雙平面非完全制振 35
3-1-3 單平面完全制振 37
3-2 相位角為 40
3-2-1 雙平面完全制振 40
3-2-2 雙平面非完全制振 44
3-2-3 單平面完全制振 46
第 四 章 實驗驗證 50
4-1 實驗設備和機台設計 50
4-2 次臨界轉速振幅分析 54
4-2-1 相位角差為0 55
4-2-2 相位角差為 62
4-3 過臨界轉速振幅分析 65
4-3-1 相位角為0 65
4-3-2 相位角差為 73
第 五 章 結論 81
參考文獻 82
附錄A 8
Effect of Fouled and Non-fouled membranes on Flux and the Rejection of Pharmaceuticals and Personal Care Products
No full text近年來，薄膜處理技術被廣泛運用在淨水場以去除特定汙染物，如溶解性固體、天然有機物、無機離子及毒性物質。本研究主要以三種PPCP及兩種奈米薄膜作為對象研究奈米薄膜去除PPCP之現象，並藉此找出PPCP及薄膜特性對於效率及去除機制之影響，利用Hermia模式來判斷積垢機制。本研究使用之薄膜機組為平板掃流式，並在不同操作條件下(pH、壓力、掃流速度及積垢物質)觀察薄膜通量衰減情形和出水品質。利用HPLC及TOC分析出流水濃度，並使用SEM及AFM分析薄膜表面。最後使用反應曲面法(responds surface method)根據實驗結果求出本實驗之最佳操作條件。
三種PPCP之去除率和薄膜之MWCO有正相關，NF270之去除率階高於NTR7450，顯示size exclusion在三種PPCP之去除階存在。在高pH值時sulfamethoxazole及triclosan之帶電性由中性便為負電性，因而electrostatic exclusion存在，使得sulfmethoxazole及triclosan之去除率提升。
根據Hermia模式預測，標準阻塞機制對於兩種模之通量衰減無法解釋，積垢物質並未進入到薄膜孔洞內而被吸附於孔內膜壁上，機構形成可能同時存在樹種機制，包括，完全阻塞、中間阻塞及濾餅生成機制。
結果顯示NF270及 NTR7450兩種積垢薄膜會提高acetaminophen之去除率，對於sulfamethoxazole則會使去除率下降，triclosan在NTR7450積垢後去除率會較未積垢之薄膜下降而在NF270積垢與未積垢並無明顯變化。對於acetaminophen之主要去除機制為size exclusion，sulfamethoxazole為size exclusion及electrostatic exclusion而triclosan則包含了三種去除機制。
積垢會改變薄膜表面特性，造成積垢後之薄膜去除效率與未積垢薄膜有所差別(可能上升或下降)。由於實驗中之三種藥物之物化特性不同其去除機制也有所不同，因而造成三種藥物在積垢和未積垢薄膜中去除率變化的差異性。
利用實驗結果及反應曲面應用程式推算結果顯示，在本奈米薄膜處理程序其最佳操作條件為操作壓力在100psi，掃流速度在0.32m/s及進流pH在10時。在此操作條件下，其預估之通量減為5.6%，PPCP之去除效率約為98.5%。Membrane or pressure-driven processes are used to remove contaminants such as dissolved solids, nature organic matter, inorganic ions, and some other hazardous compounds from water. This research investigated the effects of solute and membrane characteristics on the rejection and flux decline at various pH levels, transmembrane pressure, cross-flow velocity, and at foulant. Filtration was conducted with a cross-flow module using membrane (NF270 and NTR7450) in plate form. The concentration of effluent and membrane properties were determined using instruments such as HPLC, TOC, SEM, and AFM. The optimal operation conditions of NF filtration processes were determined using the response surface method (RSM).
There are positive correlations between rejection of target compounds and the MWCO of membrane. The rejection by NF270 was always higher than that by NTR7450 which indicated that size exclusion could be the removal mechanism of the three target compounds. At high pH, both sulfamethoxazole and triclosan are negatively charged, which implies that electrostatic exclusion could be the removal mechanism.
Standard blocking was not the main fouling mechanism for both membranes, which indicated that the molecular size of foulant in the feed solution might be larger than that of the membrane pore. Membrane fouling could be brought by the a combination of several fouling mechanisms, i.e, complete blocking, intermediate blocking, and gel layer formation.
In the presence of humic acid and calcium ions, the rejection of acetaminophen by both NF270 and NTR7450 membranes was increased whereas opposite results were observed for sulfamethoxazole. The rejection of ticlosan decreased with operation time prior to 6 hrs which could be attributed to adsorption.
The fouling layer may modify the surface properties of membrane which leads to different degrees of performance. The difference in the rejection of the three target compounds brought by distinct removal mechanisms can be attributed to their respective physic-chemical properties.
The optimum operating condition determined by the RSM was found to be at TMP of 100 psi, cross-flow velocity of 0.32 m/s, and pH 10.0. Under the best operating condition the performance was: 98.5% of rejection and 5.6% of flux decline
A Study for Application of the Parallel-line Assay to Evaluation of Biosimilar Drug Products Based on Censored Data
No full text生物製劑的市場近年來逐漸增加，但是所需的開發成本仍然很高，所以在生物製劑的專利到期以後，許多藥廠紛紛投入生物相似性藥品的研發。不同於一般的化學分子學名藥，生物製劑具有製程專一的特性，所以評估生物相似性藥品必須與化學分子學名藥有所不同。現行法規中，生物相似性藥品需依個案，適度的減免臨床試驗，才能被核准上市，成本並不小於開發新的生物製劑，無法降低成本，達到造福病患之目的。 當療效指標為設限資料時，本篇論文以對數風險率回歸檢定法評估生物製劑相似性藥品與原廠生物製劑是否為相似，以評估是否需要執行完整臨床試驗，模擬所提出方法之第一型錯誤機率、檢定力和覆蓋率，並以數值例子來介紹方法之應用。In recent years, biologics market of biological drug increases rapidly, but the development costs are also very high. Therefore, after the patent of biological products expires, many pharmaceutical companies have invested in the development of biosimilar products. But, biological products, with process specificity, are different from traditional small molecule drug products. Therefore the methods for assessment of biosimilar products are also different from that of chemical generic products. Current regulations indicate that the clinical trials for assessment can be waived on a case-by-case basis, but a pharmacovigilance is necessary. However, if the requirement for clinical trials cannot be waived, the development cost of biosimilar products will be the same as that of the innovators. It cannot achieve the goal of cost reduction, and deny of access of biological drug products to needed patients. In this thesis, we propose to apply the parallel-line assay to test whether the approval of the biosimilar products should require clinical trials. We developed the statistical testing procedure to evaluate the equivalence between the biosimilar drug product and innovator’s biological procedure when the primary endpoint is a censored variable which follows an exponential distribution. The results of size and power from the simulation studies are presented. A numerical example is used to illustrate the application of the proposed method
Regeneration Strategy of Taiwanese Traditional Agricultural Community A Case Study of Ching-Liao Village in Tainan City
No full text摘要
本研究旨在探討台灣傳統農村的再生策略，從農村人口的老化、外移、農村文化的散失、農村風貌的改變及農村產業的危機等四個面向，來探討傳統農村的再生策略。透過台南縣菁寮聚落在公私部門投入營造的經驗，發現傳統農村再生的契機及不足，進而提出台灣傳統農村共同面臨的問題的解決策略，希冀從菁寮的活化歷程，為台灣農村的發展走出一條與世界接軌的大道。
本研究的研究方法，將採文獻分析、深度訪談方式來進行，由蒐集相關文獻進行分析比較，並透過公部門在菁寮聚落進行營造之計畫書、成果報告或相關公文書、會議記錄，進行細部的分析，以了解這幾年社區發展的演變，相關的計畫產生的影響。同時，蒐集國外相關文獻，以了解其他國家在農村活化再造的成功案例，是否有值得台灣參考借鏡的地方，納入本研究的範圍。更進一步進行聚落意見領袖，就菁寮聚落目前的發展問題、政府各計畫的進行、民間組織的發展等議題，作深入的訪談。
本研究歸納出如下建議：
一、給推動傳統農村聚落再生工作者的建議
（一）涵蓋老中青三代的推動組織
（二）農村的歷史人文的調查為首要
（三）提升生活品質為先，再創造產業發展
（四）以團隊方式參與提案計畫撰寫研習
（五）成立農村學堂，凝聚共識
（六）規劃全民可參與的活動
二、給公部門推動農村再生工作之建議
（一）成立整合推動之單一窗口
（二）計畫的推動應拉長執行時程
（三）專業團隊協助蹲點逐夢
（四）舉辦農村大賽
（五）農村再生條例的執行軟體重於硬體
（六）加強農村long stay之行銷規劃
（七）創造農村產業的特色與行銷通路Abstract:
The study mainly discuss about the regeneration strategy of Taiwan traditional agricultural communities from four dimensions: population ageing and moving out, rural cultural fading away, agricultural landscape changing, as well industry risk. The opportunities and weakness of traditional agricultural regeneration had been found throughout the commitments experiences both from private and public sectors in Tainan Ching-Liao Village. Subsequently, this study proposed the strategic solutions for the problems that all traditional agricultural communities faced. In addition, the path development connecting to the world could be established based on the process of Ching-Liao Village rebuilding.
This study is applying for the qualitative research methods of literature analysis and interviewing the residents of Ching-Liao Village. We take in the evolution of community recent years and the effects by relative plans through reviewing Ching-Liao Village proposal, meeting records, and reports in detail.
At the same time, the foreign literatures have been collected. We try to realize the successful rural rebuilding cases in other countries. And, those cases might be a good reference for Taiwan. Moreover, we do conversation with the opinion leaders in communities according to the issues such as development problem of Ching-Liao Village, every project executed by the governments, the development of non-profit organization.
This study made the following propositions:
1、Propose the suggestions to the rural rebuilding workers
（1）Involve all old, middle, and young generations
（2）The first task is investigation of rural history
（3）Improve the living quality first, then create industry development
（4）Team work to join seminar and propose a project.
（5）Build a learning center for commitment
（6）Make a plan for all residents participating
2、Propose the suggestions to the rural rebuilding public sectors
（1）Reorganize an unique window
（2）Extend the time period of procedure
（3）Professional team’s assistance
（4）Carry out the rural community competition
（5）Execute Agricultural Regeneration Act in software rather than hardware.
（6）Improve the marketing plan of long stay
（7）Create the features and marketing channel of agricultural industr
A Locality-based Address Remapping Strategy for NAND Flash Memory
No full text隨著儲存裝置容量的快速成長，設計快閃記憶體管理層之位址投射機制已儼然形成
一個艱鉅的挑戰。另一方面，晶片數目的增加也造成快閃記憶體管理層設計上的困
難。不同於以往針對快取機制優化之設計，我們提出了一個根據存取行為考量所設
計的位置投射機制來進一步利用平行的特性增加效能並且同時減少不必要的資料搬
移所帶來的效能下降。這個機制不只顯著地降低不適當的配置方法所帶來的效能損
耗，並且藉由減少額外寫入提升裝置壽命。最後，藉由一系列之實驗，我們驗證了
所提出方法之有效性，並得到了令人振奮的結果。Address mapping for flash storage devices has been a challenging design problem for controllers
because of the rapidly growing device capacity. On the other hand, the increasing
number of chips bring about difficulties in design management of flash storage devices. In
contrast to existing address mapping designs that focuses on improving caching mechanism
efficiency, we propose a locality-based address remapping strategy to further utilize
the parallelism to improve the performance and reduce unnecessary data write imposed
by the improper data allocation. The experiments were conducted based on representative
realistic workloads to evaluate the efficacy of the proposed scheme. The results reveal
that the proposed management can not only improve the performance but also extend the
endurance of the flash storage device.Acknowledgment ii
Abstract in Chinese iii
Abstract iv
Contents v
List of Figures vii
List of Tables viii
1 Introduction 1
2 System Architecture and Motivation 4
3 A Locality-based Address Remapping Strategy for NAND Flash Memory 8
3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 A Two-area-based Allocating Strategy . . . . . . . . . . . . . . . . . . . 10
3.2.1 Address Translation Managements . . . . . . . . . . . . . . . . . 10
3.2.2 The Handling of Read/Write Requests . . . . . . . . . . . . . . . 12
3.3 Switch Operation and Garbage Collection . . . . . . . . . . . . . . . . . 13
4 Performance Evaluation 18
4.1 Metrics and Experiment Setup . . . . . . . . . . . . . . . . . . . . . . . 18
4.2 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2.1 Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2.2 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5 Conclusion 22
Bibliography 24
Curriculum Vitae 2
The energy and group preserving schemes for multi degree of freedoms Duffing equations
No full text在工程與數學應用中，非線性振動是個相當常見的問題，過去的文獻中已經有許多方法可以求解非線性振動的問題，但它們往往都忽略了能量守恆這個議題。在本篇論文中，我們提出了保能算法(EPS)，將無阻尼與無外力情況下的杜芬微分方程組透過李群轉換成常微分方程組，求解過程中保能算法能夠自動保持能量守恆，使得能量在長時間計算維持不變；接下來我們會繼續探討加上阻尼與外力的杜芬微分方程組，這個部分我們將使用有效且具有高精確度的保群算法(GPS)求解。最後，我們會將整個問題延伸到二維空間與三維空間中，同樣地，我們可以使用保能算法與保群算法去求解二維與三維的杜芬微分方程組。此外，我們將使用四階龍格－庫塔(RK4)方法與保能算法以及保群算法做比較，因為四階龍格－庫塔方法能夠有效地求解微分方程問題，且同時具有四階的精度，所以求出的結果相當值得我們信賴。藉由與四階龍格－庫塔方法求得之解做比較，我們可以得知EPS與GPS的優點、精確性，當然還可以藉由比較每一步所產生的能量誤差得知EPS的保能效果與優越性。In engineering and mathematics fields, the oscillatory problems of nonlinear oscillators are common problems. There are many computational methods which have been developed for solving the nonlinear oscillatory problems. However, most of these methods can not retain the energy. In this thesis, we develop a novel energy preserving scheme (EPS) for the undamped and unforced Duffing equation by recasting it to a Lie-type ordinary differential equation. The EPS can automatically preserve the total energy to be a constant value in a long term computation. Then, we will extend this problem to the damped and forced Duffing equations. Here, we use the group preserving schemes (GPS) to solve the problems, which can solve the problems effectively and accurately. Finally, we extend the problems to the coupled Duffing equations and three degrees of freedom Duffing equations. Also, we still can use the EPS and the GPS to solve the problems accurately. In each problem, we also compare the present results with the solution obtained by the fourth order Runge-Kutta (RK4) method, which has fourth-order accuracy. By comparing the EPS and RK4, we can see the advantages, accuracy and capability of preserving energy of the EPS
An Analysis of Labor Pension Act: From Cultural Views of Actors and Their Life-worlds
No full text在人口老化的脈絡下，老年經濟安全保障成了重要的議題，對此，政府亦有各種相應的制度規劃。其中，對照屬社會保險的勞工保險、國民年金，採用個人帳戶制的勞工退休金條例則顯得格外不同。因此，必須追問為什麼勞退新制會採取個人帳戶制，而不是延續其他制度的社會保險原則呢？此外，在政府所提供與宣稱的保障之外，一般人們到底如何理解這個自身退休切身相關的制度呢？基於這樣的問題意識，本研究便從文化的角度理解勞工退休金條例(勞退新制)的形成及其社會效果。從文化角度出發，可以發現政策制定層次的行動者對於退休制度該如何設計，以及一般民眾從自身生活世界出發，都自有一套論述或詮釋。這些論述或詮釋儘管各有異同，彼此甚或有一些因誤認而相合、因誤解而扞格之處，但無論如何制度總會實際涉入一般民眾的生活之中，而制度的社會效果亦在這些詮釋上的異同中被強化或掩蓋。基於這樣的理論觀點，第三章將會分析，勞退新制的形成過程中，個人帳戶制是如何隨著主要政策制訂者的變動而勝出的，在這個制度大轉彎的過程中(這甚至是路徑依賴概念難以解釋的)，除了政府的財政節約考量外，相關行動者的理念與論述扮演著關鍵的角色，而且隨著個人帳戶制的勝出，政府對於對政策的正當性主張亦有所改變。然而，勞退新制形成後的政策宣傳，反應了政府對於退休制度的想像與看法，但民眾亦有自己的詮釋方式。因此，在第四章裡，我將指出，個人帳戶制一定程度上符合民眾對於退休的期待，但有趣的是，在政府與民眾對於退休的個人化態度背後，所持理由並不相同。對政府來說，個人帳戶制減少了政府財政負擔，因而這樣的制度設計(確定提撥、個人儲蓄)便是合理措施。對民眾來說，處於由職涯、生涯所構成的身份、意義、社交的網絡之中，個人同時在網絡中付出與獲得(目前或退休後的)經濟保障，其所考量的是個體的付出、收穫與責任，因此退休後的經濟安全保障與當下個人責任有關。因而，在退休上政府與民眾看似達成共識，其實這指只是一種「誤認」，政府與民眾各自形成意見的理由、邏輯並不相同。然而，這樣的誤認有無其後果？若有代價，則必須由誰支付？因此，在第五章我將進一步指出，由於政府對勞退新制的正當性宣傳，以及對民眾的想像方式，勞退新制的社會效果並不一定能達到所宣稱的增進勞工退休生活保障的效果。對於那些職涯、薪資不穩定的勞工，也就是最需要受到保障的行動者，勞退新制的保障效果降低，但對此問題的提問卻消失在各種政策想像之中，成為政策理所當然化的盲點。在結論部分，將總結本論文的分析，並對於研究限制與未來研究方向，提出一些建言。Old age security becomes an important issue in our aging society. Among all kinds of polices made for dealing with old age security, the Labor Pension Act stands out distinctive from others for its individual account rather than social Insurance which characterizes Labor Insurance Act as well as National Pension Act. The formation process and social effect of the Labor Pension Act are analyzed in this study in a cultural perspective. Actors, based on their context and web of meaning, interpret, then to make sense of effects brought about by the Labor Pension reform. Different data, such as secondary data, interviews, and social surveys, are used to show the difference of interpretations between policy makers and actors who live in their life-worlds. As Chapter 3 shows, in the formation process of the Labor Pension Act, the frame of discourse changes, and the actors involved in the policy debate also change, not to mention the way of claiming legitimacy. The policy makers, or the government, has one way of interpretation toward the Labor Pension Act, pension system, and labor. The actors who live in their own life-worlds have the other ways to interpret the Labor Pension Actor and their own life. Chapter 4 shows that actors living in their life-worlds regard retirement as an individual issue, but with different reasons. Lifeworld actors are embedded in webs of meaning, actors, and identities. Webs change with actors’ life course. Lifeworld actors have to deal with current issues in each stage of lifecourse, and give/gain support from others in webs. So, retirement support, for Lifeworld actors, comes from actors’ webs, not individual account of the Labor Pension. Furthermore, in chapter 5, we can see the government’s claiming and interpretation creates a blind spot so that the deficiencies of the Labor Pension Act become invisible. Will those people with low income and unstable career path, namely the real in need, have enough support when they retire from work? It’s surely the aim claimed by the Labor Pension Act, but this claim has still be left without further problematization and reflection
A Fast Path Planning Method for Single and Dual Crane Erections
No full text在現代營建工程中，吊車往往扮演舉足輕重的地位，舉凡鋼筋結構物、混凝土建材、機電設備等等都需仰賴吊車的搬運，然而吊車在吊裝作業的過程中有許多操作上的危險，如碰撞與承載荷重問題，為了確保吊裝作業的安全進行，通常會以事先進行吊裝路徑的規劃來避免上述問題的發生。但是吊裝路徑規劃並不是一件容易的事，規劃者必須有相當之經驗與耐心，才能規劃出完全無碰撞且符合安全荷重範圍的吊裝路徑。
因此本研究利用電腦技術發展自動化的吊裝路徑規劃方法，其方法主要可分為兩個階段：第一階段，我們將吊裝環境以組態空間(Configuration Space, C-space)的方式來表示，此空間表示吊車、吊物、與障礙物之間的碰撞關係，並考量吊車承載荷重的安全上限值；第二階段，我們使用probabilistic road map (PRM)路徑規劃方法於組態空間中規劃出無碰撞且符合安全荷重範圍之吊裝路徑。
為了驗證本研究所提出的吊裝路徑規劃方法，我們分別進行了三項實驗：實驗一驗證本研究方法於單吊車吊裝作業的可行性；實驗二驗證本研究方法於雙吊車協同吊裝作業的可行性；實驗三進行效能測試，測試本研究方法的計算效率與路徑的操作性。由實驗結果顯示，本研究方法可適用於單吊車與雙吊車協同吊裝作業，且以接近即時的計算時間完成吊裝路徑規劃，並提供易於操作且有效率的吊裝路徑。Cranes are essential equipment for lifting objects in construction projects. There are many challenges in an erection progress such as collision avoidance and retaining the safe weight loading. To ensure the safety of entire crane erection process, it needs a precise erection plan for crane operations. However, to have a good erection plan is a difficult task, which requires rich experience and many of the detailed considerations. Engineers need to consider the capacity of crane and avoid all the possible collisions during the erection.
Therefore this research aims at developing a method for automatically finding the erection path by utilizing the computer technology. The proposed method is composed of two steps: The first step is to convert the scene of crane erection into a configuration space, in which the capacity of the crane loading and the obstacles in the environment has been considered; The second step is to find a collision free path in the configuration space by using probabilistic road map (PRM) method.
We conducted three tests to validate the proposed method in this research: The first test and the second test are used to test the feasibility of the proposed planning method for single crane erections and dual crane erection, respectively; In the third test, we conducted two scenarios to test the efficiency of the proposed method and the operational effectiveness of generated path in dual crane erections. The result shows that the proposed method is efficient and can generate effective erection path for operating in near real-time. The method can be appropriately used for both single and dual crane erection, which can help engineers to easily plan and verify the erection strategies
- …
