全國中小學科展

數學

隨機遞迴數列及渾沌現象

給定一個p∈(0,1),令k0=0,p0在(0,1)間隨機分布,定義 k1為能使的最小正整數k,而;相同的,對於給定的kn-1,kn為能使的最小正整數k,。若存在kn使得,則稱p∈In;若對於所有的n與kn,,則稱p∈I∞。如此區間(0,1)可分解成集合I1,I2,…I∞。

架構「類球狀多面體」的理論與實務

本報告的目的在:電腦Cabri 3D 軟體上模擬出「類球狀多面體」(圖1-8),\r 並實作其模型(圖9)與它們的星體(圖10)。「類球狀多面體」的定義如下:\r 可由「正多面體」切出之多面體,且需滿足以下性質:(1) 除「正多邊形」外,\r 其餘皆是「六邊形」。(2)鳥瞰每個「正多邊形」時,形狀皆保持不變。(3)\r 等長的稜數最多。\r 以「正十二面體」切出之「類球狀多面體」為例,(圖1)中兩個「正五邊形」\r 相距一個「六邊形」簡稱A1。(圖2-4)依序為A2、A3 與A5。正二十面體可切\r 得(圖5-6),正六面體可切得(圖7-8),......等。(圖9)為A2 的實體模型,\r (圖10)為A2 的星體模型。

Amazing Fairy Chess -討論多元方形鏈的數量

在這篇研究報告中,我們討論的是一種方形集合圖形的數量。”多元方形鏈”約略在 60 年代被提出,衍生出一系列的問題和遊戲,例如熟知的電玩軟體 『 俄羅斯方塊 』 ,或是 『 益智積木 』 的遊戲,都是多元方形鏈的應用。在這些問題當中,最令人頭痛的難題就是 n 元方形鏈的圖形總數。為了解決這道難題,我們採用一種轉換方法將圖形轉換成序組,並且給出序組的性質,再據此寫成 C 語言的程式;反覆地修改程式以增進執行效率及速度,最後利用該程式成功地統計出圖形總數。 In this report, we discussed the amount of polyominoes, the graphs of a set of squares. “Polyominoes” has been brought up in 1960s, and later developed into a series of questions and games, such as a well-known video game — Tetrix, and the game of puzzle blocks. Both are the applications of polyominoes. Among those questions, the toughest one is the amount of n-polyominoes. To solve this problem, we used a method which transforms the graphs into sequences. By looking into the properties of those sequences, we obtain a set of rules that can be used to determine the quantity of n-polyomines. The rules are implemented into computer codes in C language with proper modifications made to speed up the efficiency of our algorithm. The computational results show that the amount has been successfully calculated.

棋盤的費伯那契

在學校科研營的教材中,有一個題目,其內容相當於:「在一列格子中 放入黑棋與白棋。白棋不可連續放置,而黑棋不受此限,請問共有幾種可能的排列方式?,在此規則下,若將格子推廣為m列n行的棋盤,那又如何呢?我們對此好奇不已。

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。

形?與形外

在這篇研究報告中,我用了三種觀點來推廣幾何中的反演變換,首先,把反演變換視為是一種圓內與圓外的一種1-1且onto的映射,第一種推廣,是將變換中心移到視圓心以外的圓內的地方,馬上我們得到一個結論「反演半徑會隨著動點而改變」,接著,我們實驗了一下反演變換用有的一些性質,保角性,保圓性,…等在這個變換視中是否依然存在;接著我們用第二種方法來推廣反演變換,我們將邊界的形狀由圓視改成別的形狀(如三角形,四邊形…等等),然後也試試看在這種變換之下是否還擁視有反演變換的一些性質;第三種推廣,則是在研究的過程中,我發現了一種新的幾視變換,承接第一種推廣,我們將原先為定點的變換中心改為動點,將原先的動點改為定點,做出來的一種新變換。In the study, a new geometric Inversive transformation through three points is discovered. Here is the main result:(1)The first, onto cycle of inside and outside can be proved under invasive transformation. It is changed moving the center from center of cycle, we can get a new ” Inversive radius can be changed by moving drop. (2) We hope to find the answer to this problem by experiment, it is exist with the inversive properties. (3) A new geometric transformation is discovered, a fixed drop can be changed moving drop, then the first moving drop shifted the fixed drop. This leads to a new construction if the new transformation.

平面切立方體內單位立方格數極值之計算

我們先假設有一正方體及一截過正方體之平面,並設正立方體為一k*k*k 之立體。為計算平面截過之單位正立方體個數,我們必須先分別計算各層被切過之個數再將之相加,因此將各層面投影至同一平面,簡化為平面上之問題,並討論其性質/規律,計算平面截此正立方體之個數。如此,便可以一般化數學式計算平面截正立方體個數之問題。接著,用以上方法為基礎,討論各種平面切正立方體之類型,將被平面所截之單位立方體個數以電腦程式算出,觀察數字變化及其性質規則,並找出最大值發生之條件。 We initially supposed that there are a regular hexahedron consists of unitary n × n cubes and a plane which incises the regular hexahedron. To calculate the total number of the unitary cubes incised by the plane, we can first calculate them layer by layer and then sum them up. And further, we project each layer on the same plane, so the three-dimensional problem is simplified into two-dimension. By making use of the character which results from projection, we can easily calculate the number of the unitary cubes incised. Consequently, we are able to calculate them with a general equation. Afterward, we research each circumstance that the plane incises the regular hexahedron on the base of the mentioned methods. Calculate them with self-designed computer programs, and observe the regulation and change of the result. Furthermore, we can find out when it will achieve the maximum.

直角三角形生成關係的研究與發展

k(2αβ ,α2 ? β2,α2 + β2 )是大家熟悉畢氏定理的通式解,且一般書籍的証明大都採用代數的手法證明。以國中生而言,上述的代數方對國中生來說不夠直接且較無推展的實用性。因此幾何觀點出發發展另一種思考方式,利用角平線的性質給予畢氏定理比例解另一種全新的詮釋,並賦予比例解中的參數α 、β 在幾何的意義。在推理的過程中,我們得到一個相當有用的對應關係:一個有理數對應到一個直角三角形、兩個有理數對應到海倫三角形,再將此對應關係運用到各種幾何圖形上面,即可證明出他們所對應的通式解。最後我的興趣鎖定在海倫三角形、完美海倫多邊形與超完美海倫多邊形上的做圖方法上,善用我們所發展的對應關係,上述的問題皆可迎刃而解。k(2αβ ,α2 ? β2,α2 + β2 ) is a popular formula in Pythagoras Theory, often proved in algebra approach among books. Nevertheless, in light of junior high students, the aforementioned algebra method is neither direct nor practical. Hence, a different thinking method is derived from geometry perspective, using the straight line concept to reinterpret Pythagoras Theory and define the geometric meanings of α andβ . In the process of logical development, a useful correlation emerges: a rational number correlates with a straight-angled triangle, and two rational numbers correlate with Heron Triangle. This correlation can be applied to all kinds of geometrical diagrams to prove the correlated homogenous solution. Ultimately, my interest lies in the diagram methods of Heron Triangle, Perfect Heron Polygon, and Super Perfect Heron Polygon in order to apply our developed correlations to solve the above mentioned problems.

一些Moire patterns 的數學性質研究

Moire 為法文,其英譯為watered, 是古代織布技術的一種應用;將印有規律條?的透明薄片重疊時,稍微移動或轉動其中的一片,會形成極大的圖形變化,稱為moire pattern本作品針對三個moire pattern 的數學式加以推導:(一)、兩張透明片各印有等間隔平行線,轉動其中一片使兩線的夾角θ,亮紋垂直距離和暗?垂直距離的比值為tanθ/2tanθ 。(二)、兩張透明片各印有輻射線,重疊後行成圓系,可由代數或幾何加以證明,利用三角函數可推導出此圓系方程式為:x2+{y-rtan[π/2-(θ-?)]}2)]}={rsec[π/2-(θ-?)]}2)]}\r \r (三)、透明片A 印有等間隔平行線,B 印有符合高斯曲線的平行線,AB 重疊時,形成一系列的高斯曲線,AB 的夾角減少時,會增大曲線的曲率,我們進一步討論曲線的曲率和平行線斜率的關係。Moire is the French word “watered” and refers to an ancient technique employed in cloth making. The moire occurs whenever two or more transparent sheets with periodic strips on them are superposed. The characteristic of moire patterns is the fact that a slight shift of sheets will create dramatic alternations in the observed patterns. In the present report, We derive the equations of three different moire patterns. First of all, take a sheet with equal spaced straight lines and placed it on top of another identical sheet. They are made to intersect and form an angle of θ. As the angle changes slightly, it produces huge changes in the spacing of moire fringes. We can derive a formula related to the interfringe distance. The ratio of bright fringes and dark fringes is tanθ/2tanθ.Secondly, two transparent sheets with radial lines on them are overlapped, forming a pattern similar to the lines of force between point charges. We can find that the pattern is a series of circle by means of algebraic and geometric proofs. And proven by trigonometric functions, we canconclude that they satisfy the equation :x2+{y-rtan[π/2-(θ-?)]}2)]}={rsec[π/2-(θ-?)]}2)]}\r Thirdly, a set of lines of equal spacing is overlapped with a second set of lines whose spacing are derived from a Gaussian curve. A series of Gaussian curves is reproduced in a moire pattern. Reducing the angle of intersection between the two figures steepen the curvature. We discussed the relation between the curvature and the slope of inclined lines.

費曼三角形的推廣

We inferred the original Feynman triangle theorem from equilateral triangle into common triangle and from same ratios of dividing points into different ones. The conclusions are below: 由原始費曼三角形原理中的正三角形等比例分點問題,推廣至一般三角形的分點等比例及不相同之比例,得到如下之結論: