高職重補修資訊系統建構

[[issue]]6

Designing a Microfluidic Device with Nutrient Gradient

本研究目的為針對探討濃度對浮游生物影響的研究，設計一能操控濃度梯度之微流元件。所設計的微流元件為一三層結構，皆以PDMS構成，其中包含上層的濃度梯度供給流道、中層的多孔薄膜與下層的微孔穴流道。本三層構造之目的為分離上層流道與下層流道內之流場，並藉由中層之多孔薄膜層在孔穴中產生濃度梯度。下層為一孔穴觀察區，連接截面為矩形之主流道，上層之濃度梯度供給流道為對稱的雙流道設計，各別通入高濃度與低濃度之流體，以在下層之孔穴內產生濃度梯度，藉由設計多孔薄膜之孔隙數量與孔徑大小，改變濃度梯度的分布型態。 實驗結果顯示，微孔穴流道之流場最容易影響微孔穴內之濃度場，微孔穴流道之Reynolds number增加時，孔穴內平均濃度會明顯降低，但分布差異不大。此外，濃度梯度供給流道的對齊方向可以明顯改變濃度梯度的分布，若與微孔穴流道的主流道平行，濃度在y軸方向的變化較為劇烈，靠近 +y方向之濃度較高；若與微孔穴流道的主流道垂直，濃度在x軸方向的變化較為劇烈，靠近 -x方向之濃度較高。因此若要改變微孔穴內之濃度梯度場，改變濃度梯度供給流道之對齊方向的效果是最好的。此外，在濃度梯度供給流道內的流向為反向流時，孔穴內濃度場較不易受濃度梯度供給流道之Reynolds number影響。薄膜的孔隙過多時會造成孔隙率過大，使微孔穴流道之流場影響濃度梯度供給流道，染劑不易通過孔隙，因此不宜選用孔隙率過大之薄膜。然而，使用較大孔隙之薄膜時，產生之濃度梯度場較為集中，峰值可達到1500 m-1。本研究所得之結果可協助我們得知，藉由改變濃度梯度供給流道與微孔穴流道之流場，可改變孔穴內之濃度場變化，且孔隙率較低之薄膜可降低兩層流道間流場之影響，以利未來進行浮游生物同時受流場與濃度場改變之趨化性研究。This study focuses on designing a microfluidic device to generate nutrient gradient for the study of plankton in chemotaxis in the future. The PDMS microfluidic platform is consisted of three layers: the gradient channel, the porous membrane, and the microcavity channel. The 3 layer structure is aimed at generating concentration variation in the microcavity by reducing the influence from the flow field of the gradient channel. The micro cavity channel has a circular pocket connected to a straight channel. The gradient channel has two symmetrical channels, one for water and the other for the dye solution. By transport through the perforated membrane, concentration gradient is formed in the microcavity. The alignment of the gradient channel and the microcavity channel of the bottom layer can be changed to alter the concentration gradient is formed in the microcavity. In addition, we design membrane with different pore size and pitch to study their effect on the concentration distribution in the microcavity. The result shows that varying the flow velocity of the microcavity channel is the easiest way to change the concentration field. When velocity increases, the average concentration in the microcavity decreases, without significant change of its distribution. In addition, The direction of the concentration gradient can be easily change by the orientation between the gradient and the microcavity channels. When the gradient channel is aligned parallelly to the straight channel of the microcavity layer, higher concentration is found in the bottom of the pocket. When the gradient channel is aligned perpendicularly to the straight channel of the microcavity layer, higher concentration is found near the left edge of the microcavity. For the counterflow configuration in the gradient channel, the concentration is not affected by the flow in the microcavity channel. When the membrane has more pores, porosity too large such that the flow in the microcavity channel may interfere the flow in the gradient channel, which makes the dye more difficult to pass through the pores. Therefore, membrane with large porosity is not recommended. Yet, lager pore size lead to higher concentration gradient in the cavity and the pick value can reach as higher as 1500 m-1. In this study, we successfully manipulate the concentration field in the microcavity by varying the flow field in the gradient channel and the microcavity channel. To reduce the effect of flow field on the concentration distribution, membrane with lower porosity is preferred

Design of Large High-dimensional Spatial Database Systems

在本論文中，我們提出三個可用於大型高維度空間資料庫的索引結構(index structures)，這三個索引結構分別用於處理點(points)、線段(line segments)、以及區域(regions)等空間物件(spatial objects)，利用這些索引結構做空間物件搜尋時，在時間效率(time efficiency)與索引結構的空間使用率(storage utilization)有很大的改進與提升。 第一個提出的索引結構是near-optimal KDB-tree，用於處理點物件。它運用一種新穎的索引技術與節點分裂策略(node splitting policy)，將被索引的資料項目盡可能地置放於索引結構的底層(leaf level) ，進而使整體結構的儲存使用率提升至將近100%，也因而明顯地縮小索引結構的整體規模(size scale)。與傳統的點物件索引方法做比較，我們證明near-optimal KDB-tree可提升搜尋資料的時間效率與索引結構的空間效率。 第二個提出的索引結構是2D B+-tree，用於處理線段物件。它具備幾項優於傳統方法的特性，包括：更能精確地保存線段物件的空間資訊，使用較少的索引結構儲存空間，以及提供較穩定擷取物件的時間預估。 第三個提出的索引結構是compact R-tree，可以更有效率地處理具有封閉面積的區域物件。compact R-tree 將物件進行索引化後，可建立一個十分緊密的階層目錄，相較於傳統R-tree與其它類似方法的70% 索引結構儲存空間使用率，它的整體結構儲存使用率可提升至將近100%，我們的實驗數據也顯示出compact R-tree的資料搜尋效率與傳統R-tree 相比較，十分具有競爭力。 本論文提出的三個新的索引結構可以作為設計大型高維度空間資料庫的一般化系統架構，利用此系統架構來建立空間資料庫應用系統，可以有效率地的完成空間物件資料的索引化，同時讓空間物件資料的搜尋效率也能得到確保。In this dissertation, we present three new methods (near-optimal KDB-trees, 2D B+-trees, and compact R-trees) for the design of large high-dimensional spatial database systems based on points, lines, and regions, respectively. Near-optimal KDB-tree is an index structure for point objects. It uses a novel indexing technique with a new splitting policy to insert data entries in the leaf nodes as much as possible so that storage utilization can achieve up to nearly 100% and subsequently the size of the index structure can be reduced significantly. As a result, both time and space efficiency of near-optimal KDB-trees are improved significantly. A new line index structure based on B+-tree is also proposed to handle 2-dimensional line objects. Our method is superior to previous indexing methods in terms of the following major considerations: (1) can preserve more accurate spatial information about lines, (2) has less storage requirement for building the index structure, (3) has more efficient retrieval performance, and (4) has more predictable retrieval overhead. Compact R-trees are proposed for indexing MBR objects into a very compact hierarchical structure. The storage utilization of a traditional R-tree and its variants is only about 70%. Our compact R-trees can achieve almost 100% storage utilization while their search performance is very competitive as compared to traditional R-trees. The three indexing schemes developed in this research work can provide general frameworks for building appropriate index structures in the design of large high-dimensional spatial database systems. Application systems based on these frameworks will definitely guarantee space and time efficiency and, therefore, save the database development effort.1. Introduction 1.1 Problem Descriptions 1.2 Objective and Methods 1.3 Organization of the Dissertation 2. Background 2.1 Spatial Data 2.2 Previous Methods for Handling Point Objects 2.3 Previous Methods for Handling Region Objects 2.4 Previous Methods for Handling Line Objects 2.5 Queries on Spatial Data 3. Indexing Scheme for Point Objects 3.1 Splitting Policy 3.2 A New Insertion Scheme 3.3 Near-optimal KDB-tree 3.4 Index Entries with More Economic Representation 3.5 Analysis of Storage Requirement 3.6 Experimental Results 4. Indexing Scheme for Line Objects 4.1 Drawbacks in Traditional Methods 4.2 A New Line Indexing Scheme 4.3 2D B+-tree 4.4 Query Processing 4.5 Complexity Analysis 4.6 Experimental Results 4.7 Application to GIS Database 5. Indexing Scheme for Region Objects 5.1 Previous Methods 5.2 A New Indexing Scheme 5.3 Compact R-tree 5.4 Time Analysis 5.5 Experimental Results 5.6 Application to Image Database System 6. Conclusions 6.1 The Key Results 6.2 Suggestions for Future Research Bibliography VITA Publication

A Study on the Determinates of Operation Efficiency and Profit for the Container Liners in Taiwan

[[abstract]]國際海運業從1970年代開始，貨櫃船舶逐漸取代傳統之散裝貨船，歷經1980年代的蓬勃發展，至1990年貨櫃運輸競爭更加激烈，國際貨櫃航商間的合作，以航線聯營(Joint Venture)與合併(Merge)等方式，降低營運成本，以便增加國際間的競爭優勢。在實務上，航商間的競爭主要集中在兩個方面：一是滿足顧客的需求；二是維持成本的競爭優勢。在滿足顧客需求方面，國籍貨櫃航商在面對競爭激烈的國際市場，以貨物及時運送(Just-in-Time)的方式，送達顧客手上。貨主選擇航商考慮因素包括，船舶效率、裝載能力、服務可靠性、航速等方面，其中船舶效率將是影響貨主選擇上的關鍵因素；在維持成本競爭優勢方面，國籍貨櫃航商較高之容量使用率(Capacity Utilization)，將是維持成本競爭優勢重要因素。在航運造船技術也不斷推陳出新下，船舶大型化已成為海上貨櫃運輸的趨勢。在供給遠超過需求的情形下，市場呈現超額容量的壓力，航商勢必要增加它的實際產出，或者減少投入船舶艙位容量，來提升國籍貨櫃航商的容量使用率(Capacity Utilization)。在經營效率的觀點上，減少投入船舶艙位容量是否真能使國籍貨櫃船公司營運效率達到長期最適則須進一部探討。 研究實證結果顯示，在短期容量使用率，判斷航商之攬貨能力是否達成最適之產量，而長期容量使用率，判斷航商是否增加或者減少投入船舶艙位容量，達成長期最適之規模經濟。實證結果顯示萬海航運在長短期之容量使用率上，其艙位使用效率值皆優於其他三家航商。本研究以產業經濟學領域中對於產業結構（Structure）透過市場行為（Conduct）影響市場績效（Performance）的S-C-P理論為背景，建構獲利影響之因素。研究結果發現如下：短期之經營效率值、經濟成長率即規模經濟與航商之獲利呈顯著正向關係；長期之經營效率值、匯率與航商之獲利呈負向關係。價格水準、燃油價格與航商之獲利呈正向關係。[[abstract]]From 1970,the international sea transportation business has replaced the traditional bulk goods ships for container ships. Following the rising and flourishing period in 1980s, the container liners compete more and more intensely in the 1990s. From then on, the international container liners cooperates with each other, cutting down their cost of operation and increasing the capability of international competition through the ways of joint venture and merge. In practice, the competition between different container liners mainly relies in two aspects—one is the fulfillment of the requirement of clients, the other is the maintaining of the advantageous position through controlled capital spending. In order to satisfy the demand of clients, the domestic container ship corps adopts the way of “just-in-time” shipment when dealing with the intensely competing international market. When choosing the shipment corps, the owner of goods takes the following facts in concerns--the efficiency of the ship, the capability of shipment, the credibility of service as well as the speed of the ship. Among them, the efficiency of the ship is the most fundamental facts concerned by the owners of cargo. In the aspect of maintaining advantage of cutting budget, the higher efficiency in capacity utilization is a critical fact concerned by domestic container ship industry. As the technology of shipbuilding improves, the large-scale ship model has become the main trend in the container transportation business. In the situation when demand is unable to meet the supply, there is the pressure of capability above quota in the market, asking the business to increase their practical outputs or decreasing the capability of shipping space in order to improve the capacity utilization of domestic container ship industry. From the points of view considering operation efficiency, whether or not the measure to decrease the capability of shipping space can reach the goal of maintaining the long-term advantage of the shipment business is still need further discussion. The result of research reveals the fact that in the short-term capacity utilization, one should concern whether the corps can take sufficient orders or not to keep the most profitable outlets. In the long-term capacity utilization, one should consider whether or not the corps increase or decrease the capability of shipping space to obtain the most profitable economic scale. The research fact reveals that Wan-Hai shipping corps occupies the advantage in long or short-term capacity utilization and efficiency of shipping space utilization superior than those of other three counterparts. Based on the S-C-P theory of industry structure affects the market performance by conducting market actions, this research has formulated some key factors affecting the profit margin. Those factors are as follows—the short-term efficiency ratio of operation, the economic increasing rates and scale are in direct proportion with the profit gaining of shipping industry, the long-term efficiency values of operation, exchange rate are in inverse proportion as well as the profit gaining and the price level, price of fuel are in direct ratio with profit gaining

紅外線感應垃圾桶

[[abstract]]起初我們對我們的專題雖然有了構想！卻也找不到方向下手，後來看了許多網站和請教許多相關人士，走出了我們的第一步，我們用了80C51的程式來使垃圾桶作動，主要流程為接收到紅外線程式作動啟動馬達拉起線圈，使得垃圾桶蓋翻