無尾翼飛行器之穩定與控制
無尾翼飛行器(Tailless Aircraft)在軍事上的價值極大，且對於目前正在起步的微飛行載具(Micro Air Vehicle)而言，亦是值得嘗試與投資的。然而，由於無尾翼飛行器缺乏用以平衡的水平尾翼，造成其靜態的不穩定，即使設法提高靜態穩定特性，但其氣動力阻尼低、穩定性仍舊不佳。操縱上更是困難，在飛行穩定性與控制系統設計上極其挑戰性。本研究目的在探討無尾翼飛行器之穩定性與控制技術，改善其先天之不穩定特性，考慮之項目有縱向靜態穩定性、動態穩定性、控制面與組件配置等因素等進行詳細之探討。首先，找出了適用於無尾翼飛行器之Reflex翼形，接著建立無尾翼飛行器之非線性縱向動態模式，然後針對一翼展8Ocm之小型飛行器進行外型設計，並觀察分析其實際飛行狀態，再以理論與經驗公式估算無尾翼飛行器之氣動力導數，探討其飛行穩定與操控性能。此外，並運用古典控制PID控制法則，設計控制器進行非線性受控系統之動態響應模擬。由模擬結果可看出，經由翼剖面改變與控制系統的輔助下，大幅提高了其性能，使得無尾翼飛行器克服了先天的不穩定特性，更提高了其發展空間 The tailless aircraft has a great value on the military use. Meanwhile, it is worthwhile to try and to invest in it for the investigation of MAV(Micro Air Vehicle), which is being developed now. However, because of lacking horizontal tail which is used for balance, the tailless aircraft is static unstable. Even with the attempt to enhance its characteristics of static stability, the stability of the tailless aircraft is still poor for the sake of it's low damping in aerodynamics. Therefore, it is a challenge to flight stability and control system designing. The purposes of this research are to study the stability and the control technique of the tailless aircraft. To improve its congenital lacking of stability, thought over the longitudinal static stability, dynamic stability and control system. First, find the "Reflex" airfoil is suitable for the tailless aircraft. Second, set up a non-linear and longitudinal dynamic model of the tailless aircraft. Third, design an 80cm span small airplane. Hence, observe and analyze its flying condition. Finally, utilize the theoretical and experiential equations to estimate the aerodynamic derivatives and investigate its stability and controllability. Besides, use the PID controller to proceeded the time-response simulation of the non-linear system. The result of simulation shows that the performance is improved through the change of the airfoil and with the auxiliary of the control system. With this improvement, the tailless aircraft overcome the congenital lacking of stability to broaden its utilization potential.
你喝下了多少？-台灣市售優酪乳乳酸菌生長力及抗酸性之探討
現今乳酸菌飲料風行，但是乳酸菌是否真能通過胃酸的考驗，到達腸道進行複製，利益人體？我們首先以市售乳酸菌粉（加拿大Rosell 公司，含二種菌，暫時命名為"小毛"及"小白"）為預測菌種，利用分光光度計測定乳酸菌於Thioglycollate 培養基中的生長能力（OD600）。小毛在pH 值 1、 3 、5、 7 時之生長力分別為0、 0.008 、0.682 、0.847 ，小白為 0、 0.015 、0.973、 0.636。若於培養基中添加不同濃度的螺旋藻熱分解物，如加入0.01%的添加物後，小毛在以上各種pH 值生長力分別為0.042、1.291, 、1.447, 、1.213 ，小白為 0.053、1.392、 1.531、 0.988，意外發現可大幅提升菌的生長力及抗酸力。再取台灣市售4 種廠牌優酪乳（以甲、乙、丙、丁代表之），分離乳酸菌，再於各種pH 值中培養。結果在pH 3 時，螺旋藻熱分解物僅對丙廠牌有效, 乙廠牌無效, 甲與丙則有無填加生長力都很差。在pH 1 時, 則對乙、丙、丁皆有效，故建議廠商慎選菌種，並於製程及成品中添加螺旋藻熱分解物。The yogurt is a popular drink. But whether the lactobacilli inside can resist the destruction of gastric acid and grow well in the intestinal tract is still questionable. We used pure lactobacilli powder (Rosell Company, Canada, containing two bacteria named in this report as "Little Hair" and "Small White") for pre-test. The growth ability in thioglycollate medium was determined by spectrophotometer (OD600). The results of bacterial growth at pH 1, 3, 5, and 7 for "Little Hair" were 0, 0.008, 0.682, and 0.847, respectively. Those for "Small White" were 0, 0.015, 0.973, and 0.636, respectively. After supplement with 0.01% of the boiled lysate of Spirulina algae (ProBio Biotech, Taiwan), growth abilities at pH 1, 3, 5, and 7 for "Little Hair" were 0.042, 1.292, 1.447, and 1.213, respectively. Those for "Small White" were 0.053, 1.392, 1.531, and 0.988, respectively. The algae extract amply promotes the growth and acid-resistance, especially at pH 3, of these bacteria. The lactobacilli isolated from four different products of yogurt in Taiwan, named as A, B, C, and D, were then tested as above. Results showed the supplement with the boiled lysate of Spirulina algae was very effective, at pH 3, for promoting growth of C, but not effective for B. Growth abilities of both A and D were very unsatisfactory with or without this supplement. At pH 1, algae lysate supplement significantly improved the growths of B, C, and D. Therefore, this supplement in culture and product for yogurt preparation was suggested.
關於渦旋
A professor once told me that scientists have already known a lot about vortices, but less about how to tackle with them in here and there cases. As to my mind, this means knowing by halves. As a matter of fact, I gradually found that human may not know more than a dragonfly! A dragonfly flying in a figure of eight pattern does know about Vortices Recycling. The highlight of the experiment is the hovering ability upon a fixed point in the air. Who can stay longer will be the king of Vortices. Sometimes I am not so optimistic about mimicking a fly or a bat, but I am really very interesting in discovering which flying mechanism is more effective,『Fling Mechanism』 or 『In a figure of eight pattern』, if with the same weight and energy? How to implement their mechanism in our flying machine? It is always the best policy to do naturally with vortices. The conservation of vortices is found here and there. Vortex itself is energetic. To gain means to keep. The one who is able to keep vortices will be rewarded. As in life generation and the ability of hovering, the rule follows. Typhoons and tornados still threat us like the beasts. And what’s more, a jumbo-airplane was crashed as beaten by tip vortices of the former airplane. As the dragonflies, the beautiful acrobats of vortices , infuse in tip vortices. Not the strong contradistinction did we realize that it is time for vortices!研究渦旋已經四年。四年之中，涉獵了許多關於渦旋的實驗。當我越了解渦旋，就越佩服那些卓越的昆蟲朋友們，他們可說是調配利用渦旋的大師。從候鳥遷徙的V字型隊伍、海豚的渦旋氣球、到蜻蜓八字型的飛行機制，我很想知道：在一個固定的流場中，到底哪一種運動機制，能最有效率的提供上升的力量？而如何將昆蟲朋友們的高超技術，運用到人類飛行載具上？將是我有興趣的另一項課題。『關於渦旋』是一系列渦旋實驗，目的就是自基礎開始深入了解在地球這樣環境下渦旋的性質。（一）探討基礎的渦旋本質（二）產生相對運動下物體的的渦旋架構（三）物體取得升力和失去升力的要件（四）昆蟲飛行機制探密（五）未來展望與渦旋的運用經過長時間的觀察可以了解到：1、渦旋遵守動量守恆。是以渦旋出現時是成對的2、渦旋是具有能量的。在上升力取得方面，當攻角過大時，渦旋剝離，造成能量的損失；以至於飛行載具失速。而蜻蜓是保有渦旋並加以利用的高手，自然事半功倍。順勢而為，渦旋增強。
凸多邊形完美分割線的尋找
1) First, we studied the properties of lines and segments that bisect a triangle’s perimeter. By observing the properties, we found a “revolving center” what we defined. We employed the revolving center in the construction with ruler and compass to make “triangle’s perimeter bisectors” that pass the points we desire. Later, we found out the “envelope\r curves’” equations of the “perimeter bisectors” on the triangle’s two sides are parabolic curves. Moreover, the focus of this parabolic is just as same as the revolving center. 2) The curves envelope of area bisectors formed a hyperbolic curves. By similar method of constructing a “perimeter bisector”, we can also construct an “area bisector”’ by using the hyperbolic curve’s focus. We accidentally found out that we can construct the tangent of the conic by using our method, too. Different from the information we found, It supplies a easier method to construct the tangent of a conic. 3) With the rules of constructing perimeter (area) bisectors, we can expand the method to constructing the “perimeter (or area) bisectors” of any convex polygons. 4) We call the lines that bisect the convex polygon’s perimeter and area at the same time the "perfect bisect lines”. Based on the properties of the” perimeter bisectors” and the “area bisectors” in our research, we found out that the” perfect bisect lines” pass the intersection of the” perimeter bisector’s effective segment” and the hyperbolic. Thus, we can construct the “perfect bisect lines”. Moreover, we proved the esistence of the “perfect bisect lines.”1. 首先我們先探討三角形等分周長線的性質，利用性質及觀察等周線的變化，我們找到可利用本研究所稱的「旋轉中心」，以尺規作圖的方式，作出「任意點的三角形等分周長線」。接著我們導出三角形兩邊上等周線所包絡而成的曲線方程式為一條拋物線的曲線段。進而發現上述的旋轉中心，即為等周線所包絡而成拋物線的焦點。2. 三角形兩邊上等積線所包絡出的曲線是一條雙曲線的曲線段。利用等周線的尺規作圖，我們找到同樣可利用焦點當旋轉中心做出等分面積線。意外的發現出圓錐曲線的切線作圖，皆可利用我們的研究方式(有別於已查出的文獻上記載)，較快速的作出切線。3. 利用三角形等周線(或等積線)的尺規作圖，可擴展到「過任意定點作出凸多邊形的等周線(或等積線)」。4. 我們將同時分割凸多邊形等周長與等面積的分割線稱為「完美分割線」。利用三角形研究出的等周線與等積線相關性質，我們找出完美分割線必通過同角的等周有效段與等積曲線段之交點。利用這結果可作出完美分割線。並進一步，我們證明出凸多邊形完美分割線的存在性。
「從害羞到大方需要多少時間」(環境因子對含羞草開葉時間的影響)
含羞草會因為受到各種不同外界刺激(光照、外力等等)，而造成膨壓改變。外 觀上表現出葉片閉合或有葉柄下垂的現象。其中含羞草處在黑暗的環境下一段時 間後，會做出睡眠運動。當它重新暴露於光照之中，將會需要一段時間以恢復原 先葉片張開的樣子。這個實驗是研究不同類型的環境因子(主要是光照和溼度)在打 破睡眠運動之後，對其葉片復原時間所造成的影響。我們針對上述環境因子在不 同狀況時，進行我們的實驗上百次，進一步得到了多項的數據。也在實驗中，為 了精確了解整個恢復的程序，而將恢復程序程序做成書面說明。以下是我們所紀 錄與分析完數據後的結果，以及我們在實驗期間，進行一些不同的實驗嘗試，所 發現不同於表面所見的驚人事實。 The mimosa can accept plenty of stimulation (light, force, etc), which results in the change of turgor pressure, and on outward appearance, it shows the phenomenon that the leaves become closed or that the stalks get pendent. Among the stimulation, the mimosa will undergo nyctinasty when it is left in the dark for a period of time, in order to enable it to be exposed to the light once more, which requires certain time. This experiment is based on how different kinds of elements of the environment (primarily light and hydro level) effects the rehabilitation time after the nyctinasty is broken. A large number of data are gained after experimenting on it for hundreds of times. Steps of habilitation are also made into illustration in writing, so as to understand the whole steps accurately in the experiment. Below are our records and analysis based on the data, including a few special experimental tries during our working time, in which some surprising facts that were discovered are different from what are seen on the surface.