電腦科學與資訊工程

The Information Technology (IT) area has shown great growth in recent years, even with the economic recession that 巴西 has been through and the impact of the coronavirus pandemic. It is estimated that by 2024 the area will have a deficit of more than 290 thousand professionals. However, companies still face other difficulties in hiring, especially people who are looking for their first job in the Information Technology area. Most part of these difficulties are lack of qualified manpower and high prerequisites to fill internship or junior positions. As a result, the objective of this project is: to develop a platform that connects people who seek guidance, improvement or professional relocation in the Information Technology area with professionals that already have the experience they are seeking. The first step was a research and analysis of similar platforms in the market, whose proposal involves mentoring or professional connections, and it concluded that there are no services that fully meet the project’s proposal. In the second step, a research was done about mobile development, highlighting Flutter and Firebase platform. The third step defined the application’s features, such as suggestion of users and mentors, search for users, become a mentor, private chat, video calls, Portuguese and English languages, light and dark themes and profile customization. The suggestion of users and mentors is done by a match with the registered users, relating their areas of work (where the user has experience) and the areas of interest of each one. For the coding of the project, Flutter and Firebase technologies were used. To design the app, it followed Material Design specifications. For testing and distribution, the app was published on Play Store, Google’s Android application platform. The tests were performed by both the researcher and a selected group of users to verify if the functionalities were in accordance to what was defined in the beginning of the project. Perceiving the correct functioning of the application, the project achieved the proposed objective. In addition, it expanded its reach area, because it is possible to find users and mentors from any other area of the market.

本研究利用NASA的SRTM 1 Arc-Second資料集來收集全球各地的地形高度圖(heightmap)，也利用MapTiler網站收集相對應的衛星空照圖，用這些收集的圖像，訓練我們建構的VAE-pix2pix模型。VAE-pix2pix為Variational Autoencoder (VAE)及pix2pix (為一個Conditional Generative Adversarial Network)結合的模型，能將人工繪製的高度圖加上真實山脈應有的細節(包含尖銳的山脊、山壁上的紋路、連續的河流網路等……)，並生成出相對應的擬真衛星空照圖。相較於原pix2pix模型，VAE-pix2pix所生成的高度圖及衛星空照圖會更接近於真實世界的地形高度圖及衛星空照圖，同時VAE-pix2pix模型也能透過改變latent code的數值來生成出不同風格的高度圖及空照圖，如地貌的顏色或雪線的高度等，這些都增加模型生成圖像的多樣性。為了使我們建構的模型能更廣泛的被應用，我們在Unity上開發了Unity客戶端，其生成的mesh可以讓使用者直接應用於遊戲的場景，簡化了遊戲中生成擬真山脈模型的任務。

基於音樂輸入的動作骨架生成是一個正在興起的研究主題，然而在弦樂樂器的演奏骨架生成上，由於動作與音樂資訊間並非是一對一的對應關係，且在時間序列上非常注重前後關係，此問題仍非常具有挑戰性。在研究中，我們設計新的架構，將小提琴演奏者的演奏各部分拆解並分別生成。針對前人研究及此研究的研究結果，我們分別進行了客觀測試及主觀問卷的評估，兩方面皆顯示我們的研究結果較前研究進步。就我們所知，此篇研究是第一個嘗試在小提琴演奏動作上加入音樂情緒的研究。

We study the creation of physical adversarial examples, which are robust to real-world transformations, using a limited number of queries to the target black-box neural networks. We observe that robust models tend to be especially susceptible to foreground manipulations, which motivates our novel Foreground attack. We demonstrate that gradient priors are a useful signal for black-box attacks and therefore introduce an improved version of the popular SimBA. We also propose an algorithm for transferable attacks that selects the most similar surrogates to the target model. Our black-box attacks outperform state-of-the-art approaches they are based on and support our belief that the concept of model similarity could be leveraged to build strong attacks in a limited-information setting.

本研究提出一套創新的人體健康分析方式，透過全新的分析演算法架構深度解析脈搏訊號中的特徵，並結合深度神經網路進行預測，最後開發成監測人體健康的嵌入式系統。本研究基於血液共振理論，將光體積變化描計圖法擷取到的脈搏訊號進行訊號處理，從中擷取出共振峰值以及其變化量，檢測血液循環一週的微小變化，改善了當前分析方法著重在計算平均值，無法呈現即時狀態的缺失。本研究提出的系統和演算法所延伸的預警系統具有77.3%的預測精準度，同時可以擴展至多種趨勢相關的臨床症狀。此外，本系統十分適合應用於低功耗、低成本的硬體，對於未來各種行動裝置、穿戴科技與居家照護的生理數據分析需求，可提供實質的貢獻。

強化學習為當前AI領域的熱門話題，其特點是在環境的獎勵與懲罰下，進行學習。強化學習雖然較為困難，但其成功的項目都非常有名，其中最著名的例子有: AlphoGo、AlphaZero等等。 深度強化學習(DRL)是深度學習與強化學習的結合體，本專題透過DRL實現近端優化策略演算法，來使BipedalWalker環境中的二足模型學會行走，並調適超參數與神經網路來讓模型訓練擁有更好的結果。 經過實驗後發現，適當的降低獎勵折扣衰減率能有效的提升學習速度以及學習上限，同時可以避免分數落差過大導致的Dead relu問題。最終的結果能讓平均分數達到302分，成功達成了BipedalWalker環境要求(平均分數>=300分)。 為了使智能體擁有更好的探索能力，本專題加入了ICM(Intrinsic Curiosity Module)，成功提升了最終的平均分數至316分，將不摔倒的機率提升至99%，最高分數則到了320分，使得雙足模型能以更快的速度向前移動並保持穩定。

本研究旨在設計一個使用模式，以不切換中、英文輸入法打字的原則之下，能夠完整的自動辨識出一個包含中文（注音、嘸蝦米、倉頡）與英文完整句子。經實測結果，正確率達到94.23%以上。

密碼為我們生活中常見的一項工具，它可以為我們保護我們的隱私，以免受到別人侵犯，但也同時間出現許多問題，例如：若密碼太過單純會使密碼的功能失去意義，讓其他人可以輕易存取使用者的資料。 在臺灣，注音文密碼是十分常用的密碼，因為它乍看像亂碼，其實有一定的規律存在，而這些密碼，卻容易被判斷為安全的密碼，因此，我們希望可以將這個問題改善。 在研究中，我們先研究密碼強弱，再探討注音文密碼中在一般密碼中的比例，最後達成我們希望的目標—寫出一個可以偵測加入注音文策略的程式。在研究中，我們亦討論各個密碼演算法的優點及缺點，以找出可以最準確判斷的程式，並在研究的最後，提出可以將這套方法擴充至其他語言或是輸入法的可能性。

本研究以AI虛擬試衣系統(Virtual Try-on)為主題，透過深度學習技術，並結合幾何匹配模型，開發出試衣系統，可將使用者上傳的照片，模擬成穿著新衣的模樣。 首先，以深度學習模型將人物原始圖片取出骨架節點，並生成人體遮罩以及保留人物頭部，再結合以上三種資訊合成為高維特徵圖。接著將目標替換衣物生成出依照人體姿態扭曲後的衣物圖片。最後於Virtual Try-on模型中將人體高維特徵圖與扭曲衣物作為輸入，並經過深度學習網路合成出穿著目標衣物之人體圖像。本研究結果發現，人物站姿單純，且雙手緊貼身側，以及拍攝角度為正面、衣服款式為短袖、背景色彩對比度較高與衣服圖案單純的原始圖片，可得到較好的合成結果。

This work is devoted to solving the problem of orientation in the space of visually impaired people. Working on the project, a new way of transmitting visual information through an acoustic channel was invented. In addition, was developed the device, which uses distance sensors to analyze the situation around a user. Thanks to the invented algorithm of transformation of the information about the position of the obstacle into the sound of a certain tone and intensity, this device allows the user to transmit subject-spatial information in real time. Currently, the device should use a facette locator made of 36 ultrasonic locators grouped in 12 sectors by the azimuth and 3 spatial cones by the angle. Data obtained in such a way is converted into its own note according to the following pattern : the angle of the place corresponds to octave, the azimuth corresponds to the note and the distance corresponds to the volume. The choice of the notes is not unambiguous. However, we used them for the reason that over the centuries, notes have had a felicitous way of layout on the frequency range and on the logarithmic scale. Therefore, the appearance of a new note in the total signal will not be muffled by a combination of other notes. Consequently, a blind person, moving around the room with the help of the tone and volume of the sound signals, will be able to assess the presence and location of all dangerous obstacles. After theoretical substantiation of the hypothesis and analysis of the available information, we started the production of prototypes of the devices that would implement the idea of transmitting information via the acoustic channel.