國王的海市蜃樓
在夏日的午後，在炎熱的柏油路面上很容易可觀察到遠方的 路面上，出現如鏡子般的倒影，看起來彷彿前方有一灘水，但當 我們向前進一些時，倒影卻突然消失了，這個現象，一般稱為海 市蜃樓。 一般解釋海市蜃樓的成因，都是由於在上層的低溫空氣，和 在下層靠近路面的高溫空氣，因密度的不同，以致於折射率的漸 層差異，繼而產生全反射。 但我們觀察發現，地面與上層空氣的溫差，並非柏油路面上 假積水現象及倒影出現的必要條件；反而和入射光的角度、路面 的平坦程度及路面的性質有關。我們提出了粗糙面在入射光的入 射角接近90度時，可發生單向反射的模型。並由實驗來驗證假積 水現象及倒影主要的成因是「柏油路面的單向反射」而非「空氣 的折射與全反射」。 Under the scorching sunshine, we can see the reflection on the tarmac in the distance just like a water puddle on the road. And the water also reflects the people and object nearby. But, in fact, the tarmac road over there is very hot and dry. Therefore we call the phenomenon as the “false water puddle on the tarmac.” According to the textbook , the main reason for “false water puddle on the tarmac” is that the temperature difference leads to the refraction of the light and causes the phenomenon. However, from our observation, the theory still can’t explain some phenomenon, For example, the “false water puddle on the tarmac” remains to appear when the wind blows fiercely. Even with little temperature different at night the phenomenon is still obvious. Therefore, in our opinion, the temperature different of the air is not a necessary condition of “ the false water puddle on the tarmac.” We bring up the model to explain the phenomenon that when the incident angle of the light approach 90 degrees, the light will result in one-way reflection. According to the model, furthermore, we make experiments at midnight and at dawn. The result of the experiment assures us the hypothesis of the model, Consequently, we hold the ideal that the main condition of the “false water puddle on the tarmac.” Is not because of the refraction and the total reflection but because the light reflects off the road and result in the one-way reflection on the tarmac road.
聚球藻 RF 一 1 品系生物時鐘之特性
我們成功的用溶氣計偵測到了聚球藻 RF-1 在 28℃下光合作用的概日韻律。和傳統的研究方法比起來，這個方法具有連續偵測的優點，減少因不斷取樣所造成的影響，此實驗可觀察到聚球藻 RF-1 溶氣量之變化圖與一般藻類（如單殼縫藻）不同.在光 /暗條件下 RF-1 之溶氣量的增加與減少均呈週期性變化，而且此變化現象在進入連續照光後仍然可以維持兩個循環以上，這些結果顯示以溶氣計連續偵測聚球藻 RF -1之概日韻律是可行的，而且所得到的變化圖形遠比傳統方法（於不同時間取樣）所得者自然。本實驗同時發現含聚球藻之培養液的溫度，在進入黑暗週期時會有明顯的上升，由於其變化程度比其他藻類明顯，如加以探討應有助於對此藻以及其韻律特性之瞭解。We successfully detected the photosynthesis circadian rhythm of the prokaryote Synechococcus RF-1 under 28℃ by a DO (Dissolved-Oxygen) meter. The advantage of this method, comparing with the traditional methods, is that it can detect signals continuously, reduce the influence of discrete sampling. The DO curves of the Synechococcus RF-1 are different from that of other algae. Under Light/Dark conditions, the DO values of RF-i increased and decreased periodically. The periodic phenomena progressed over two cycles under constant lighting conditions. These results revealed the feasibility of using DO meter to continuous detect the circadian rhythm of the Synechococcus RF-1 The detected DO curves looked more natural than those obtained in the traditional discrete-sampling method. We also found that the temperature of the culture increased in dark cycle. Since the variation is clearer than that of other algae, further investigation will benefit the understanding of the Synechcoccus RF-i and its circadian rhythm.
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。