影像的色偏校正
The human eyes can adjust automatically the color of object under different illuminants. But digital camera does not have such mechanism, must join the white balance to simulate the color constancy of human eyes. There are many existing white balance methods. They can be categorized into two types. The first type utilizes the widespread assumption on the dealing natural scenery, which has the advantage of simplicity. Another type explores knowledge of the semantic content, which has the advantage of accuracy. In this study we modify and enhance the widespread assumption methods that can adopt the advantage of the simplicity and accuracy. Our proposed method is structured in two main parts: a color cast detector and a color cast remover. The detector first analyzes the color distribution of the image with simple statistical tools to determine whether or not the image has color cast. The remover, a modified and enhanced version of the widespread assumption methods ( gray world and max RGB ), is then applied on the color cast image. From the experiment results, it demonstrates the efficacy and performance of the proposed method.人類的視覺能夠自動修正因光線變化而改變的物體顏色,但是數位取像設備的感光元件卻不具有這樣的功能,必須加入白平衡的功能,才可模擬人眼維持色彩恆常的特性。現有的白平衡演算法可分為兩大類型,第一類型為廣泛假設型,具有運算速度快、與取像設備無關的特性,但是平均誤差會較大;另一類型為預知特性型,其特徵為準確性較高,但是運算較速度較慢、建立色彩特性資訊時所需的成本較高,本篇研究針對廣泛假設型的演算法做些修正與增強,使其具有較小的平均誤差以獲得較佳色彩品質的影像。我們將影像的色偏校正分為色偏偵測與色偏移除等兩個階段來進行,由於僅有被偵測出有色偏的影像才需要進行色偏的移除,所以可以避開將無色偏或固有色偏的影像做錯誤的修正,由實驗的結果看來,我們的方法確實有效,除了具有運算速度快、與取像設備無關的優點外,其色偏校正能力也較現有的方法好,使得影像色彩更能與人眼所見相近。
利用浮沈子測量液體表面張力並演示"Cheerios Cheerios effect"
密閉容器置入待測液,放入浮沉子,施加壓力,當浮沉子恰要沒入液中瞬間,因表面張力的總力達極大值且向上,外加壓力(p1)為極大值,浮沉子沒入液中;液面減壓,當浮沉子在液面正下方時,外加壓力 p2,量 p1、(p1- p2),浮沉子的質量 m,外半徑 R,及玻璃管的體積 G V ,可求得液體表面張力。 液面再減壓,浮沉子恰要露出液面時,表面張力的總力達極大值且向下,外加壓力(p3)為極小值,量 p3、(p2- p3),浮沈子的質量 m,外半徑 R及 G V ,應亦可求得表面張力;但實驗時浮沉子漂移到容器邊,並吸附在器壁上,因此發現浮沉子的”Cheerios effect”。 利用浮沉子和容器的相吸及相斥現象,可解釋西式早餐的小榖片放入牛奶中為何會漂移到碗緣,並支持 Vella在 2005 年 9 月份美國物理期刊(AJP)認為 Cheerios effect的成因除了由於接觸角不同外,浮力、重力、表面張力共同作用,使小榖片間有相吸、相斥現象。 The experiment apparatus is equipped with a Cartesian diver by using a glass tube with air trapped inside that floats or submerses in a closed vessel containing liquid. The external pressure may be varied with a syringe and measured with a water manometer. The maximum pressure P1 inside the vessel is measured when the diver is just about to sink, where the surface tension that acts on the diver is upward. Then the pressure P2 of the vessel is measured when the diver is just beneath the liquid surface, where no surface tension acts on the diver. Finally, the surface tension is calculated from P1, P2 and the radius of the diver, R. When the pressure inside the vessel is decreased, the diver will rise. As the diver is about to emerge from the liquid, we get the minimum pressure P3 inside the vessel, and the surface tension that acts on the diver is downward. By measuring P3, P2, and R, the magnitude of surface tension is found to be the same as above. When the diver is just about to sink into the liquid, it floats to the center of the vessel. When the diver is about to emerge from the liquid, it sticks to the wall of the vessel. This phenomenon is named the “Cheerios effect.” Our results again strongly support that the cause of the effect is due to the different contact angles between the diver and water, as well as the balance of gravity and surface tension in the case of the sinking diver, and the balance of buoyancy and surface tension in the case of rising diver as Vella claimed in his paper (AJP 73, 817 (2005)).
榕樹粗萃取液對種子萌發及生長之影響
相剋作用是指植物在代謝過程中釋放出有毒物質以抑制本身或鄰近植物種子萌發及植株發育生長的過程。一般認為,榕樹是具有相剋作用的常見植物,但很少見到相關的文獻探討。本實驗利用榕樹不同組織萃取液,以小白菜、結球白菜與阿拉伯芥作材料,探討該萃取液對上述植物發芽與生長之影響,結果顯示榕樹葉萃取液所造成之影響較顯著,不同榕樹組織的萃取液、不同濃度的萃取液對不同植物所產生的效果不盡相同,針對不同生長期的植物進行處理所造成的影響亦有差異。進一步以管柱層析法與高壓液相層析法(HPLC)分離葉萃取液,結果發現以正己烷和乙酸乙酯75:25為沖提液的條件下,於HPLC的層析圖中分離時間約8分時所流出的物質具最明顯的抑制作用。電泳剖面分析顯示處理與未處理間有些許蛋白質條帶差異,此變化蛋白可能與植物幼苗對該萃取液之耐受性有關。利用核酸微陣列(microarray)對榕樹萃取液處理之阿拉伯芥植物進行基因表現分析,發現榕樹萃取液對植物部分基因表現也有促進和抑制的情形,經由基因體與蛋白質體分析法可推論出一些受影響之相關基因。 Allelopathy was defined as a phenomenon which certain plant species, by secreting metabolites to the environment, can suppress the growth of themselves, seed germination and/or growth of other plants in the same habitats. Banyan (Ficus microcarpa L.f.) is a plant species in our campus likely to have allelopathy effect. However, documents describing such action on allelopathy were rare. In this study, we applied the crude tissue extracts including leaves, stems, roots of banyan onto the germinating seeds of Pai-Tsai (Brassica rapa L.ssp.chinensis(Rupr.(Olsson))), Chinese cabbage (Brassica pekinensis Rupr.) and Arabidopsis(Arabidopsis thaliana, ecotype Columbia-0) to study the effects of such plant extract on the germination and seedling growth of other plants. It is found that allelopathic effects on seed germination vary among different tissues used for extract preparation. Different concentration of the extract also yield various degree of allelophathic effects. It is also noted that the application of extract onto the post-germinated sprouts has less effects on plant growth. The extract of leaves was subsequently chromatographed over silica gel using hexane/EtOH gradient solvent system and HPLC. The result showed that there was one fraction about 8 min in the chromatography of HPLC eluted with 25% EtOAc in hexane had the most inhibitory effect. SDS-PAGE analysis on the electrophoretic profiles of water soluble proteins has explored a different band pattern between the treated and non-treated sprouts. The observed band difference might provide a clue for exploring proteins which reacted differently upon the application of extract. DNA microarray analysis on the effect of banyan extract on Arabidopsis gene expression has also been employed to characterize genes responsive to the allelophathic treatment. Cross-comparison between the differential transcript and protein profiles will reveal key regulators in plants experiencing allelophathic condition. \r
含環胺-亞胺雙牙配基及其鎳錯合物的合成、結構鑑定,及烯烴催化聚合反應
本研究合成含環形胺—亞胺雙牙配基鎳金屬催化劑,用以催化烯烴聚合反應。將2-甲基丙醛經由溴化、胺化及亞胺化的步驟合成含胺—亞胺的雙牙配基,Et2NCMe2CH=N(2,6-iPr2C6H3) (3a)、(c-C4H8)N- CMe2CH=NPh (3b)、RNCMe2CH=N(2,6-Me2C6H3) (R = c-C4H8 3c,c-C5H10 3d)。再將配基和Ni(DME)Br2 (DME = 1,2- 二甲烷氧基乙烷) 反應, 形成鎳金屬錯合物Ni [Et2NCMe2CH=N(2,6-iPr2C6H3)]Br2 (4a)、Ni[RNCMe2CH=N (2,6-Me2C6H3)]Br2 (R = c-C4H8 4c,c-C5H10 4d),並作結構鑑定。其中3b、3c、3d、4c、4d 均為合成的新化合物,4d 獲得X 光單晶繞射結構。
以合成之鎳錯合物作為催化劑,催化乙烯或降冰片烯(C7H10)的聚合反應,探討反應活性和高分子產物的性質。與含相同碳數的錯合物比較,在胺基具環形取代基的錯合物對乙烯的催化活性較佳,聚乙烯產物分子量較高,分子量分布範圍狹窄;其對降冰片烯的催化活性略遜於非環形者。同為環形取代基時,六環較五環者對乙烯的催化活性較差,但對降冰片烯的催化活性較佳。顯示乙烯聚合與降冰片烯聚合有不同的反應決定步驟。催化劑及配基的設計的確可以操控聚合反應及其高分子產物的性質。
The synthesis of α-amino aldeimines Et2NCMe2CH=N(2,6-iPr2C6H3) (3a), (c-C4H8)NC Me2CH=NPh (3b), RNCMe2CH=N(2,6-Me2C6H3) (R = c-C4H8 3c,c-C5H10 3d), as well as the nickel complexes Ni [Et2NCMe2C- H=N(2,6-iPr2C6H3)]Br2 (4a), Ni[RNCMe2CH=N (2,6-Me2C6H3)]Br2 (R = c-C4H8 4c,c-C5H10 4d) has been succeeded. Their structures were mainly determi ned by spectroscopy or elemental analysis. The complex 4d was characterized by X-ray crysta llographic analysis. It shows that the nickel complex has distorted tetrahedral configuration.
The catalytic reactions of ethylene or norbornene polymerization using the newly synthesized nickel complexes are studied. All catalyts show high activity toward studied olefin polymerization. Comparing the data of the catalytic ethylene polymerization for complex 4c with those of its isomer complex 4a, the former is found to results in higher activity as well as the larger molecular weight of the PE products with the narrower dispersity. On the contrary, 4c shows lower activity in the reactions of norbornene polymerization than 4a. For the cyclic amine derivatives, 4c of five-membered amino group shows better catalytic activity toward ethylene polymerization than 4d of six-membered amino group. But 4d gives better perfomance for norbornene polymerization than 4c. Such results indicate that the processes of ethylene and norbornene polymerization might have different rate-determining steps. These study confirms that the design of ligand and catalyst are crucial with respect to the control of the catalytic olefin polymerization and the properties of the polymeric products.
東方帆船推進原理探討
本文研究風洞中之風帆在不同條件下,受風吹拂所產生之升力與阻力關係,並探討及成功 的以數學模型解釋其原因,此研究結果可應用於帆船帆面之設計。其主要探討之變因為以下 之五種: (一) 風速大小對帆船帆面之受力關係:當帆面與風向垂直時,在低風速時,實際測值較接近 風速的一次方的函數關係。高風速時,實際測值接近為風速的二次方的函數關係。 (二) 帆面積大小與受風推進力之關係:當帆面與風向垂直時,在風速固定風速下實驗,得到 面積與風對帆推力成正比。 (三) 順風航行時,帆面之攻角(θ)與受風推進力之關係:航行方向的力與sin 2θ 成正比關係。 (四) 側風航行時,帆面之攻角(θ)與受風推進力之關係:帆面在攻角大於 45°時,航行方向的力與sin θcosθ 有相當程度的吻合,而在攻角0°~45°之間則與飛機攻 角升力資料相接近。 (五) 初步探討雙桅帆與單桅帆面受風推進力之不同:發現其在側風時能有效的減少失速的現 象,在帆面高攻角時,能減少失速現象,依然可以持續穩定的航行,我們也可推想出飛機 的機翼前段的縫翼功能也是如此。 This article is derived from our research of relation between lifting power and its resistant power produced via wind-blow in a wind tunnel under different terms and condition, also to discuss and to explain their causes successfully via mathematics models, thus, the result of this study may be applied in designing of sail-surfaces of sails boats. Its major discussion can be included into the below 5 kinds: - Relation of (1) Relation of sizes of wind-speed against reacceptance of aerodynamic forces over sail-surface: When sail-surface and wind direction becomes horizontal, under low coin-speed, practical measured-value is rather close to wind-speed's linear function relation. When in nigh wind-speed, the practical measured-value is rather close to wind-speed's quadratic function relation. (2) Relation of size of sail-surface and pushing power of wind: When sail-surface and wind direction becomes horizontal, an experiment was made under fixed wind speed, the result obtained is sail-surface size and pushing wind power toward sail is in direct proportion. (3) When it is in “round-the-clock wise” navigation the angle of attack (θ) of sail-surface and the relation with wind's pushing power: Strength of navigation direction and sin2θconforming direct proportion. (4) When it is in side-wind navigation, the angle of attack (θ) and pushing power by wind relation; When the sail surface is in the angle of attack (θ) greater than 45o, the navigation direction power and sinθcosθhas certain extent of conformity, and between angle of attack e 0o-45o, happens to be very appropriate with aircraft's angle of attack and lifting power data. Fundamental discussion of Double Masts Sail boats and Single Mast Sail boats comparing differences of wind-aided pushing power: It was found that stall phenomena could be decreased effectively, when it is side-winded, especially, when the sail-surface is at high angle of attack, it could decrease Stall phenomena, and could maintain stable navigation. We can also assume that the front section of aircraft aide-wing’s function exactly the same.