面對一個終身學習，多元化學習的社會，學習的方法不再侷限於閱讀或求教於師了，取而代之的是電腦科技的變革。上屆學長利用線上代理人融入遠距教學的作品令我印象深刻，但總覺得少了些趣味及互動性，於是本實驗嚐試將虛擬實境加入線上代理人及遠距教學，利用空間魔法師建構出來的環境，讓使可者能夠融入其中，悠遊在虛擬的世界，並配合鍵盤的滑鼠的控制移動，點選建構出來的虛擬物件，透過超連結連結至網路上的知識網頁，配合線上代理人的互動及帶領，結合了主動、趣味、互動與便利，開創未來的學習方法，一個講求效率、速度及克服空間無時無刻都能學習的環境。With the arriving of 21st century，things are widely different，including the ways of learning. Because of the revolution of multi-media，computer technology will change the traditional way of learning. I was impressed by the master piece 「Long-distance with Agent」 which was done by the schoolmates last semester. But I feel their work still have much room for improvement，so I combine to use the virtual environment with the advantages of their work. Learners can move and click the objects in the virtual reality space，and they can be linked to the knowledge website through the Internet. Learners can enjoy the interesting ，fast，interactive and efficient learning environment. This work is done by the Space Magician Ver3.0， which is used to design a 3D virtual reality environment. And the users can enjoy the net-surfing and through the hyperlinks to get the information.

醫學上的植皮手術成功率受皮膚厚度影響，皮膚愈薄癒合速度愈快，其中以取皮厚度介於0.05mm 到0.1mm 為佳。在實驗量測時，需要經過一連串繁複的薄皮標本製作，再放到光學顯微鏡下測量，這種厚度測量方式不但耗時，又因嚴重損毀皮膚而不精確。由於使用螺旋測微器做接觸式測量會有形變的問題，因此我們想做間接接觸式的測量，所以採用氣體為媒介，做非破壞性檢測膜厚，這對於在皮膚上的施力遠小於螺旋測微器或是接觸式膜厚計。我們設計一套三頭連管線，使用空氣為媒介，儀器運作原理為在管線一端針頭非常靠近被測物時，所流出的氣體會受到被測物阻礙產生反壓使管線內的壓力上升，導致連通於另一管路的氣泡指示計壓出氣泡，當氣泡為最大氣泡時（半球形）視為達到平衡狀態。實驗時先用已知厚度且不變形的蓋玻片來當作被測物，此時可以算出針尖至蓋玻片的實際距離做為參考值。在量測軟性薄膜時，設計上採用兩側雙針頭靠近軟性被測薄膜兩側以達到氣流氣泡平衡，這時使用螺旋測微器讀取兩針尖距離，減去已知參考值的兩倍距離，即可測出未形變的軟物質厚度。本研究開發一套能測量軟性薄膜的厚度裝置，尤其在皮膚厚度測定上，不但不會直接接觸標本造成損毀，並且能夠快速地測量出厚度值，此為本儀器的最大特色。The thickness of skin graft has deterministic influences on the success of graft surgery. Experimental measurements of skin graft thickness involve complicated specimen preparation processes followed by optical microscopic examination, which are time-consuming and may incur inaccuracy due to possible damage. Here we propose a novel method using air as the media to avoid direct contact of the measured object. The physical operation relies on the following principles: When the tip of a needle connecting to a catheter system is placed close to the object to be measured, the air pumped forward from the catheter system becomes impeded by the object. The resulting backflow pressure opposing the air flow causes an increase in air pressure within the catheter and inflates the bubble connected at the other end. Balance at maximal surface tension is attained when the bubble reaches its maximum volume in hemispherical shape. In practice, a two-needle design was used, each approaching simultaneously from each side of the object. A micrometer was then used to read the distance between the two needle tips, from which the film thickness was derived, subtracting the thickness of the air layer pre-calibrated using cover glass with known thickness. The system implemented was capable of measuring thickness on soft thin films with an accuracy of ± 0.001mm. In addition to rapid measurements with high accuracy, since the pressure exerted on the skin graft is much less than in conventional calipers requiring direct contact, our method has the unique non-distorted and non-destructive advantages.

在網路上看到甩毛巾、皮鞭的影片，會產生巨大的聲響，查找了資料，我們知道當發聲體超過音速時便會產生音爆。部分文獻提到，毛巾或皮鞭生成音爆原因是來自於角動量守衡理論，我們想利用實驗方法來驗證其正確性，因此利用video point 來分析影片討論手的加速度和毛巾末端質量、長度的關係，並用crocodile physics 做電腦模擬，我們發現毛巾長度與音爆產生無關，這樣和角動量理論模型有所不同。所以我們嘗試利用能量守恆及自由端反射駐波理論來解釋毛巾產生音爆關係，並利用影片分析及crocodile physics 驗證其正確性。We saw the film clippings on the Internet about snapping towels and whips, which made a big noise. After going through related literature, we found out that it is called the sonic boom .Some papers say that the sonic boom results from the Location momentum conservation theory. To prove its accuracy, we used a kind of computer software called Video Point to analyze in the clippings the movement of the hand, understanding the relationship between the mass of the towel end and the length of the towel. We also used another software called Crocodile Physics to simulate the whole process. We discovered that there is no connection between the length of the towel and the sonic boom. It does not conform to the Location momentum conservation theory. We then in turn employed energy conservation theory and the trait of the standing wave (specific wave length) to explain, when we also used Video Point and Crocodile Physics to prove.

The feasibility of new design approach for dual-band antenna array using genetic algorithm is demonstrated in this study. In the past year, one dual-band printed-strip dipole antenna, which operates at 0.9/1.8 GHz, had been implemented in the laboratory and leads to a satisfactory performance. However, the antenna element is suitable for application at base-station rather than handset. Conventional antennas suitable for base-station application are arrays, which consist of antenna elements and at least one feed network. Feed networks for antenna arrays are usually designed to operate at single-band capability, and therefore, it requires two feed networks for a conventional dual-band antenna array. Nevertheless, a dual-band antenna array fed by signal feed network is feasible in our study. To begin with, a full-wave solver ID3D is applied to evaluate the impedance matrix of antenna array with eight elements. Then, the antenna array is modeled as a cascaded equivalent transmission line such that the genetic algorithm could network of dual-band antenna array and yields a seven-section design, which meets the specification of base-station antennas.在過去的一年裡，本人曾製作過具有雙頻效果的雙面印刷偶極天線，並得到不錯的量測結果。由於此天線單元於實際應用上適於基地台天線陣列之設計，所以本研究著眼於天線陣列的設計。傳統上天線陣列的結構包含了兩個部分，分別是天線單元以及饋入電路。目前基地台所使用的大多都是單頻天線陣列，在雙頻天線陣列部分，通常需要兩個饋入電路分別對不同頻帶作訊號的饋入；因此，我們希望能實現使用單一饋入電路製成雙頻天線陣列的想法。本研究中，我們利用之前所做出來的天線單元來合成陣列，並希望此陣列在0.9HGz和1.8GHz兩個頻段都能產生良好的共振效果。我們利用電磁模擬軟體IE3D估算具有八個天線單元的天線陣列阻抗陣列後，再將此天線陣列轉換成串接式等效傳輸線電路。借由基因演算法(genetic algorithm)對此電路做最佳化，我們可以求得饋入電路各段傳輸線的尺寸。由此研究發現，我們的方法應用於單一饋入電路之雙頻天線陣列的設計是可行的，而此電路的模擬結果亦符合基地台天線陣列的規格。

在嗜甲烷菌中，甲烷與甲醇間的轉化是由甲烷單氧化酵素來進行。目前已知有兩種型態\r 的甲烷單氧化酵素，一種是溶解型甲烷單氧化酵素，存在於較低銅離子濃度之水溶液環境中﹔\r 另外一種為微粒體甲烷單氧化酵素，鑲嵌在細胞內質膜上，表現於較高的銅離子濃度環境下。\r 除了本身的天然基質－甲烷之外，其他種類之簡單烷烯類化合物，甚至芳香族化合物，均可\r 作為此酵素催化的基質。其中，甲烷單氧化酵素將丙烯轉化成環氧丙烯與甲烷轉化成甲醇的\r 催化活性非常接近，因此丙烯普遍被用來作為酵素活性測量的基質。為了直接測量它們的活\r 性，我們設計出一種方法，可以讓我們直接利用氣相色層分析儀，來偵測細胞的催化反應過\r 程。基於異丁烷在甲烷單氧化酵素幾乎不存在任何活性，故我們將其作為內標準氣體，並藉\r 由丙烯在氣相色層分析儀中吸收訊號的遞減來偵測細胞的催化活性。在多樣性的動力學實驗\r 中，我們發現以sMMO 為催化酵素時，丙烯的轉化是依據一級動力學反應趨勢而減少。相對\r 的，以pMMO 為催化酵素時，丙烯的減少趨勢則是依據零級動力學反應模式進行。在比較完\r Pipes 緩衝液、上清液蛋白質及內質膜蛋白質溶液之丙烯吸附量測試結果後，我們發現內質膜\r 蛋白可吸附的丙烯分子相對於其它兩種溶液是最多的。依據Michaelis-Menten 動力學理論，\r 可得到以下結論﹕丙烯的轉化在sMMO 中是以基質受限的催化形式進行，而在pMMO 中則\r 已達到最佳的催化速率。\r \r In methanotrophs, the oxidation of methane to methanol is catalyzed by methane\r monooxygenase. There are two distinct forms of the enzyme associated with different gene\r products. One is the soluble methane monooxygenase (sMMO) expressed in the cytosolic portion\r of the cell and grown under copper-limiting growth conditions. The other enzyme is the\r particulate methane monooxygenase (pMMO), a membrane-associated protein that is expressed\r under high copper-to-biomass ratios. In addition to the natural substrates of methane gas,\r simple aliphatic alkanes, alkenes, or even aromatic compounds could be used as the substrates of\r the methane monooxygenase. In those gaseous simple alkenes and alkanes, propylene converted\r to propylene oxide by methane monooxygenase has been considered as popularly use for enzymatic\r activity determination because of its comparable activity to the methane gas. To measure the\r catalytic behavior of the methanotroph directly, we design a method to choose isobutane as the\r internal standard because of the negligible activity in the methane monooxygenase. The catalytic\r activity can be simply inferred from the decrease of the gaseous propylene signals in the GC\r chromatograms by generating the liquefied epoxides mediated by MMO within the methanotrophic\r bacteria. Under various kinetics measurements, when we incubate the methanotroph grown under\r copper-limiting concentrations, we observed the diminishment of propylene follow a first-order\r kinetic behavior with the over-expression of soluble methane monooxygenase. However, the\r growth of bacteria under 40 M presents the zero-order kinetic trend with the bulk expression of\r pMMO. After the quantification of the dissolved propylene in the deionized water, soluble\r proteins solution as well as membrane proteins solution, we observe the membrane proteins could\r adsorb more propylene molecules in comparison with the other solution mixtures. By considering\r Michaelis-Menten kinetics, we conclude the propylene conversion in sMMO is under substrate\r limiting catalysis whereas the pMMO has attended the optimized velocity of propylene conversion.

蟋蟀聲音與行為的關係密不可分。取北部四種蟋蟀樣本，以數位錄音筆錄製及電腦軟體分析蟋蟀的聲音，並用PCR技術萃取蟋蟀的粒線體DNA(16S)加以分析，藉此和傳統的形態學分類相互比較。結果發現蟋蟀聲音的頻率特性中主頻率的差異在親緣遠近有關聯性，但聲音的時間特性方面則沒有特定關聯，不過聲學分析圖仍可作為單一種的鑑定指標。此外，研究發現此4種蟋蟀的聲音頻率範圍有重疊現象，但主頻率、脈衝比、唧聲率及唧聲長不同，推測雌蟋蟀應是綜合這些特性辨別同種。另一方面，以黑蟋蟀作為研究對象，進行干擾實驗，觀察並繪製出其聲音行為模式; 並將此作為對照，結果發現蟋蟀的生殖行為主要受到雄蟋蟀的聲音支配，而雄蟋蟀則以嗅覺辨別雌蟋蟀位置，決定下一步行動，與視覺較無關係。 Cricket's voice is closely related to the behavior. We select four species of crickets from the northern Taiwan to study the acoustic and mating behaviors. The digital sound recorder and acoustic software are used to analyze their acoustic characters. Furthermore, the PCR technology is used to amplify and sequence parts of mtDNA sequences and the results were compiled as the comparison to the traditional morphological character. The result shows that the resolution in acoustic characters of main frequency, pulse number, chirp rate, and the length of chirp are different among four species, though the minor frequency pattern is overlapping. Moreover, we find that frequency characteristic difference among four species is partly related to their phylogenetic relationship, yet is not seen in time characteristic. It is obvious that difference of acoustic behavior can be regarded as identified index among species. Results of acoustic analysis impel us to infer that the female crickets take the comprehensive acoustic behavior to distinguish their specific male. In addition, behavior pattern and model of Gryllus bimaculatus are established as the comparison of interfering experiment is undertaken. Which results suggest that the mating behavior in cricket is dominated by males’ acoustic behavior, and is initiated by male’s olfactory sense rather than that of sight.

Purpose of the research I had a bicycle accident eight months ago and I suffered an opened humeral fracture. I wasn’t able to get up on my feet, I had to suffer on the ground while a couple accidentally walked there, and they called the emergency services, I lost a lot of blood and the doctors had to cut a small piece of muscle out of my biceps. Now this shouldn’t have happened if there were a faster method on making first aid. Example an intelligent flying robot could easily handle this situation. Procedures There is a hexcopter and a quadcopter. Both of them has cameras with live image transmissions in Full HD and they also have GPS. They are equipped with a lot of sensors (image recognition with Raspberry Pi, 6 axis distance sensors, long range communication modules) and with these they are able to solve problems just a bird or a human does. These drones can communicate up to 1.8 kilometers, they communicate with the main server, they share their knowledge with each other and this way they can learn about the world and about the terrain that surrounds them. In a very basic way they are able to learn… Each time they make their flying techniques smoother and their database is growing. These drones can cooperate and save lives faster than humans do. They are also able to fly in non-accessible zones by themselves with no human help. For example with their sensors they can fly in and map buildings that are inaccessible for people. They can also do artificial farming with their object recognizing features, like recognizing plants and colors. (Right now they are calibrated to look for survivors alone in the mountains/forests.) They go to a given GPS coordinate then they are flying in a spiral form to find the injured people in less than a half hour. I really hope that one day these flying intelligent machines will save lives! Note: (I probably can only take one drone with myself to Taiwan, because of the traveling restrictions on planes.)

磁性流體（magnetic fluids）是一種含有磁性奈米粒子的液體，當磁場外加於磁性流體時，流體中各磁性奈米粒子的磁矩會沿外加磁場方向排列，而導致粒子間相互吸引，形成較大的磁性叢集，即所謂的磁鍊。當外加磁場增強，該磁鍊數會變多，並使磁性流體的折射率產生變化。磁性流體的折射率變化會隨外加磁場之變大而增大。本研究除探討磁性流體折射率受外加磁場控制的變化情形及其物理原由外，並進一步運用此特性研發可調性光纖「光調制器」 ，以探討磁性流體可調性折射率應用在光電元件上的可行性。A magnetic fluid is one kind of colloids which contain magnetic nano-particles. Under an external magnetic field, the magnetic moment of nano-particles is aligned along the direction of the external magnetic field. This leads to the agglomeration of magnetic particles and to form magnetic clusters under an external magnetic field. With the formation of the magnetic clusters, the refractive index of magnetic fluid is varied. The refractive index of magnetic fluid was found to increase under a higher magnetic field. In this work, In addition to investigating in detail the behavior of the field-dependent refractive index of the magnetic fluid, we also explore the relevant physical origins. Furthermore, the feasibility of developing fiber-optical modulators by utilizing the tunable refractive index of magnetic fluids is discussed.

目的：紫色桿菌（Chromobacterium sp.）是一種生活在土壤及水域環境的革蘭氏陰性菌，它會產生紫黑色的紫色桿菌素（Violacein），因而使菌體與培養液皆呈紫色。Violacein是一種由兩個L-色胺酸（L-tryptophan）分子所聚合成的五環化合物，已被證實具有抗菌以及抑制腫瘤細胞生長的活性。本實驗的目的在探討紫色桿菌是否會利用不同官能基的L-色胺酸，合成不同的Violacein衍生物，並分析這些Violacein衍生物的生物活性。方法：將紫色桿菌培養於液態LB培養基中，分別加入不同濃度的L-tryptophan、1-CH3-L-tryptophan與5-OH-L-tryptophan，於室溫下培養48小時，再用乙酸乙酯萃取Violacein及其衍生物，將萃取出來的紫色桿菌素，用紫外光/可見光分光光譜計和質譜儀進行分析。最後，再將這些萃取物打入斑馬魚受精卵做胚胎毒性測試，並進行試管外DNA剪切能力分析。結果：加入不同官能基的L-色胺酸所合成的產物都是紫色，且在紫外光/可見光的光譜中的最大吸收波長皆相同，質譜儀分析結果則顯示，L-tryptophan 、與5-OH-L-tryptophan的產物圖譜不同、而1-CH3-L-tryptophan的產物則無法分析。斑馬魚胚胎毒性測試結果顯示，Violaecein和1-CH3-Violacein 不會對胚胎發育造成影響，但是5-OH-Violacein則會造成胚胎發育異常。DNA 剪切能力測試也顯示，只有5-OH-Violacein具有剪切DNA的能力，其他則否。重要性：本實驗成功地利用紫色桿菌合成Violacein及其衍生物，並發現了5-OH-Violacein比Violacein 具有更高的生物活性。;Aims: Chromobacterium sp. is a Gram negative bacterium which inhabit in soil and water environments. Chromobacterium produce a purple color compound named Violacein. This colorful compound makes Chromobacterium and its culture mediumin purple color. Violacein is a five rings compound synthesized from two L-tryptophan molecules. Studies have shown that Violacein has anti-bacteria and anti-tumor activities. The purpose of this study is to investigate whether Violacein can be synthesized from different tryptophan analogues, and whether these Violacein derivatives have different bioactivities. Materials and Methods: Chromobacterium sp. was cultured in liquid medium containing different concentrations of L-tryptophan, 1-CH3-L-tryptophan, and 5-OH-L-tryptophan. After 48 hours incubation at room temperature, Violacein and its derivatives were extracted by EA, analyzed by UV/visible spectrophotometer and MS. Violacein and its derivatives were also tested for their embryo toxicity and DNA cleavage activity in vitro. Results: The compounds synthesized from different tryptophan analogues were all purple and have the same maxima absorption wave length in the UV/visible spectra. However, MS spectra of compounds synthesized from L-tryptophan and 5-OH-L-tryptophan were different. The results of zebrafish embryo toxicity tests indicated that violaecin and 1-CH3-Violacein had no effect on embryo development, but 5-OH-Violacein caused development defects. DNA cleavage tests also showed that only 5-OH-Violacein could digest DNA in vitro. Violaecin and 1-CH3-Violacein could not digest DNA. Significances: Results from this study indicate that Chromobacterium sp. can be used to synthesize Violacein derivatives from different tryptophan analogues, and revealed that 5-OH-Violacein is a higher bioactivity compound than violaecein.

Because the electrolyte solution used in an alkaline battery is a concentrated KOH solution, the zinc electrode in such a battery undergoes both a charging reaction and a corrosive reaction with the alkaline solution. The corrosive reaction not only reduces the lifetime of the battery but also produces hydrogen, which can cause the battery to explode and burn. Most of the zinc alkaline batteries currently on the market use mercury plating on the zinc electrode to increase its resistance to corrosion. To reduce corrosion of the zinc electrode in an alkaline battery and to avoid the use of toxic mercury, this study aimed to design a device to measure the quantity of hydrogen gas produced during the charging of a zinc-silver battery. We plated the zinc electrode with the immersion electroless plating method, using several different kinds of low-polluting anticorrosive additives(metallic compounds such as lead, tin, and indium)instead of mercury. We also used the vacuum immersion electroless plating method and added zincate ion into electrolyte solution to reduce further the quantity of hydrogen produced. The results of the experiment revealed that either a 10:1 or 100:1 ratio of lead to tin under optimal conditions will yield much better results than mercury.鹼性電池中使用的電解質溶液為濃氫氧化鉀溶液，因此電池中的鋅極除了放電反應之外，也會與濃鹼溶液中發生腐蝕反應。鋅極的腐蝕作用不僅會降低電池放電壽命，而且所產生的氫氣更可能使電池發生爆裂燃燒的危險。目前市面上所售之含鋅鹼性電池，大多是用鋅極鍍「汞」作為鋅極抗腐蝕的方法。為了改善銀鋅鹼性電池中鋅極在放電時的腐蝕效應，以及減少其所產生的氫氣量，本實驗設計了一動態放電裝置，可用於檢測銀鋅電池的放電電壓、放電時間與鋅極腐蝕反應的氫氣生成量。本研究藉由浸鍍其他低污染性金屬溶液 (鉛、錫、銦的化合物)來取代不環保的鍍汞製程，並進一步設計抽真空的浸鍍裝置，以及電解質溶液採用含有ZnO22-的KOH溶液，有效的降低電池中氫氣生成量。最後綜合所有優良條件，以鋅極採用真空浸鍍(Pb:Sn)為(10:1)及(100:1)的條件，此舉非常有效地提高電池中鋅極抗腐蝕性。此項製程所使用的Pb、Sn污染性質遠遠低於目前工業上所使用的汞製程污染，而且製程成本也遠遠低於Hg製程成本。

The purpose of the research is to investigate the settling mode of the viscid micro-particle, such as the ones from the “Miso Soup”, in static liquid. We constructed the “constant temperature environment” by constant temperature trough and transparent glass trough. The data is gathered from pictures captured from DV and then analyzed by Media Player. We did a stability test prior to the start of the experiment and found the system with good stability. The results of the experiment are as followed: 1. The settling mode can be divided into four phases: (a) Initial accelerated phase (b) Maximum phase (c) Gradually decelerated phase (d) Stationary phase. 2. The lower the fluid concentration is in the fixed temperature: a. the faster its settling interfaces appears; and the deeper it becomes for the depth of its settling interface. b. the faster the maximum sedimentation rates of the settling interface becomes and the slower it appears. 3. At the fixed concentration, the higher temperature: a. has the bigger maximum sedimentation rates of the settling interface b. gets to the stationary phase sooner c. has shallower stationary settling interfaces d. the time when the settling interface appears is independent with the temperature 4. The shape of the container has no effect on the settling mode as the settling interface is always perpendicular to gravity field. 5. If we add salt into the liquid, the stationary settling interfaces of the result will be higher than non-added ones.本研究的目的在於探討味噌這樣的微小黏性顆粒，在靜止液體中的沈澱模式。運用恆溫槽與透明玻璃水槽所建構之恆溫環境透過數位攝影機，以電腦播放軟體於特定時間擷取畫面進行分析。在正式實驗前，進行了穩定性試驗，發現穩定性良好。實驗的結果發現：一、 沈降模式：可以分為四個時期，分別為（一）起始加速期（二）高峰期（三）逐漸穩定期（四）完全靜止期。二、 在固定溫度下，溶液濃度越低：(一) 出現沈降交界面的時間越短且穩定距離距液面越深。(二) 沈降面沈降速率最大值越大且出現的越晚。三、 在固定濃度下，溶液溫度越高：(一) 沈降面沈降速率最大值越大。(二) 沈降交界面完全靜止期出現的時間越短，也就是越快達到穩定。(三) 沈降交界面的穩定距離距液面越淺。(四) 沈降面沈降速率最大值出現的時間與溶液的溫度無關。四、 容器內部的形狀與沈降面的沈降行為並沒有影響，都是成與重力場垂直的水平線沈降。五、 添加食鹽之後最終穩定沈降面比同濃度同溫度的高了許多。表示添加了食鹽對於味噌溶液有阻止沈澱的效果。

本實驗改良菲左測定光速之實驗，將原本的光路以光纖取代，並將原本的光源改為紅外光。做了上述的改良以後，可將實驗的空間及時間縮小。實驗中輸入固定頻率的紅外光載送週期性的訊號經光纖傳輸後，利用示波器觀察訊號的延遲時間，以此實驗技巧可精密計算出光速。在輸入訊號為0.1~5MHz時，光在光纖的平均速率為2.09×108 (m/s)。換算真空中光速c＝折射率n(1.467)×光纖中速率v(2.09×108m/s)＝3.03×108 (m/s)，平均百分誤差0.43%，平均誤差為0.13×108 m/s，準確度為99.57%。 若取最佳輸入頻率2~3MHz所得到之數值，光在光纖的平均速率為2.05×108 (m/s)。換算真空中光速c(3.00×108 m/s)＝折射率n(1.467)×光纖中速率v(2.05×108 m/s)，平均百分誤差為0.33%，平均誤差為0.01×108 m/s，準確度為99.67%。 A method using optical fiber is described for measuring the velocity of light . Measuring the velocity of light usually needs a long distance and in a brief time. These experiments use optical fiber and TOSA and ROSA