Hardware optimization of SHA-256 hash operation unit

在信息安全领域,SHA-256算法被广泛应用于数字签名、身份认证、消息完整性验证等方面。为满足应用对SHA-256算法运算速度上的要求,本文利用流水线的设计思想,提出了一种四级流水的哈希计算结构,提高了运算速度,增大了吞吐率。最终,本文在Virtex-7系列FPGA开发板上实现了SHA-256哈希运算单元,最高工作频率可达到319MHz,吞吐率达到2405Gbps,吞吐率面积比达到2.529Mbps/Slice。SHA-256 algorithm is widely used in digital signature, identity authentication, message integrity verification etc. In order to speed up SHA-256 algorithm computing, a four-stage pipeline processing for SHA-256 is proposed. Implemented on virtex-7 FPGA series, the proposed SHA-256 can work at 319 MHz, and archive a throughput of 2405 Gbps.The ratio of throughput/area is 2.529Mbps/Slice

Loop Closure Detection Algorithm Based on Greedy Strategy for Visual SLAM

动态环境与视觉混淆严重影响视觉闭环检测性能.基于贪心策略,提出了一种在线构建视觉词典的闭环检测算法.算法优先处理Surf描述与已有单词Surf描述欧式距离最大的特征点,改进特征点与单词Surf描述最近邻的约束条件,生成了表征性能强、量化误差小的视觉词典,算法具备实时性,并在动态环境图像集与视觉混淆多发生的图像集上,在确保100%,准确率的条件下,最大召回率分别提升了5%,与4%,.The performance of loop closure detection is seriously affected by dynamic objects and perceptual aliasing in the environment. Based on greedy strategy, a real-time loop closure detection approach using online visual dictionary is proposed. The process of dictionary construction gives priority to dealing with Surf feature that has the maximum Euclidean distance from the closest vocabulary word. A more discriminative and representative visual vocabulary is produced through adding constraint condition to the nearest neighbor distance. This visual vocabulary guarantees a small quantization error. The proposed approach meets real-time constraints. Experiments based on datasets from dynamic environments and visually repetitive environments demonstrated that the largest recall rate increased by 5% and 4% respectively at 100% precision. © 2017, Editorial Board of Journal of Tianjin University(Science and Technology). All right reserved.国家自然科学基金资助项目(61274133). Supported by the National Natural Science Foundation of China(61274133

Loop Closure Detection Algorithm Based on Greedy Strategy for Visual SLAM

动态环境与视觉混淆严重影响视觉闭环检测性能.基于贪心策略,提出了一种在线构建视觉词典的闭环检测算法.算法优先处理Surf描述与已有单词Surf描; 述欧式距离最大的特征点,改进特征点与单词Surf描述最近邻的约束条件,生成了表征性能强、量化误差小的视觉词典,算法具备实时性,并在动态环境图像集; 与视觉混淆多发生的图像集上,在确保100%,准确率的条件下,最大召回率分别提升了5%,与4%,.The performance of loop closure detection is seriously affected by; dynamic objects and perceptual aliasing in the environment.Based on; greedy strategy,a real-time loop closure detection approach using online; visual dictionary is proposed.The process of dictionary construction; gives priority to dealing with Surf feature that has the maximum; Euclidean distance from the closest vocabulary word.A more; discriminative and representative visual vocabulary is produced through; adding constraint condition to the nearest neighbor distance.This visual; vocabulary guarantees a small quantization error.The proposed approach; meets real-time constraints.Experiments based on datasets from dynamic; environments and visually repetitive environments demonstrated that the; largest recall rate increased by 5%, and 4%, respectively at 100%,; precision.国家自然科学基金资助项

Research on Graph Optimization Algorithm with Loop Closure for Visual SLAM Back-end

移动机器人技术是当前科学技术发展中最为活跃的领域之一。即时定位与地图构建(SimultaneousLocalizationandMapping，SLAM)是机器人进入未知环境遇到的第一个问题。随着视觉传感器的普及，基于视觉的SLAM得到了广泛的关注。视觉SLAM系统可分为前端视觉里程计和后端优化两个过程。视觉里程计的作用在于提供粗略的位姿估计和地图表示；而基于闭环的后端优化对消除机器人位姿估计的累积误差、实现地图的一致性至关重要。 闭环检测与图优化是SLAM系统后端优化的基石。实时性是影响SLAM系统应用的主要因素。基于视觉词典的在线闭环检测技术与COP-SLAM方法分别是闭环检测与图优化在...Mobile robot technology is one of the most frontier fields in the development of current science and technology. Simultaneous localization and mapping is the first problem encountered by robots in an unknown environment. With the popularity of visual sensors, Visual SLAM has been widely concerned. A visual SLAM system can be partitioned into two parts: front-end visual odometry and back-end optimi...学位：工学硕士院系专业：信息科学与技术学院_电路与系统学号：2312014115309

僵直性脊椎炎病人身體心像之相關因素 Factors Associated with Body Image in Patients with Ankylosing Spondylitis

[[abstract]]背景：僵直性脊椎炎病人較一般人遭遇更多生理及功能的損壞，為身體心像紊亂的高危險群，但在臺灣這群病人身體心像的相關因素卻很少被充分探究。目的：探討僵直性脊椎炎病人身體心像的情形及其預測因子。方法：採橫斷性相關性研究及方便取樣，收案時間為2017年1月至12月，由北臺灣某一醫學中心免疫風濕科門診招募120位僵直性脊椎炎病人。以結構性問卷及病例審查進行資料收集，研究工具包括人口學資料、跌倒史、巴斯僵直性脊椎炎疾病活動指數、脊椎炎功能指數、疼痛及身體心像等量表。結果：整體身體心像平均分數為68.16±16.14分，14.2%一年內曾跌倒，九成以上有不同程度的疼痛。多元迴歸檢測顯示脊椎炎疾病活動度分數越高（β=-.31,p= .005）；脊椎炎功能指數越高（β=-.24,p= .026）；有跌倒史者（β=-.16,p= .023），身體心像得分越低，多元迴歸模式整體解釋變異量為47.9%（F=10.95,p＜ .001）。結論／實務應用：疾病活動度、失能狀況和跌倒史與僵直性脊椎炎病人的身體心像感受有顯著相關，臨床人員應定期評估病人疾病活動狀態及身體心像變化，提升病人自我管理能力，並將預防跌倒及疼痛控制整合於照護計畫，以提升病人的身體心像及生活品質。 Background: Patients with ankylosing spondylitis typically exhibit a greater number of physical and functional impairments than do members of the general population and are a group at high risk of body-image disturbance. However, the factors associated with body image among this population have not been adequately explored in Taiwan. Purpose: To explore the status of body image and its predictors in patients with ankylosing spondylitis. Methods: A convenience sampling-based cross-sectional and correlational study was conducted between January and December 2017. In total, 120 patients who had been diagnosed with ankylosing spondylitis were recruited from the immunology and rheumatology department of a medical center in northern Taiwan. A structured questionnaire and chart review were employed to collect research data. Instruments included demographic data, fall history, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), the Numeric Pain Rating Scale (NRS), and the Rheumatic Arthritis Body Image Scale. Results: The mean score for body image was 68.16 ± 16.14. Overall, 14.2% of patients had experienced a fall in the previous year, and more than 90% of participants experienced various degrees of pain. The multiple regression result revealed that patients with a higher BASDAI (β = - .31, p = .005) score, a BASFI higher (β = - .24, p = .026) score, and had a fall history (β = - .16, p = .023) had higher negative body image scores. The total variance explained in the multiple regression model was 47.9% (F = 10.95, p ＜ .001). Conclusions/Implications for Practice: Disease activity, disability, and fall history were associated with body image in patients with ankylosing spondylitis. Clinical professionals should regularly assess the disease activity and body image of patients and promote their self-management abilities. Furthermore, fall prevention and pain control should be integrated into care plans to improve patients' body image

Living Donor Liver Transplantation: The Decision Experience

[[abstract]]活體肝臟移植手術是因應器官捐贈短缺，而需要解救末期肝病病人生命的一個選擇，而決定採用活體移植的方式可能是整個家庭成員之間互動的結果，從本文的案例發現，由於是自己的親人需要新的器官，捐贈者是義無反顧，有捨我其誰的情操，會經歷掙扎、不捨、害怕與猶豫等天人交戰的時刻，透過對醫護人員的信任、評價自己的情況與風險使決心更加確定。另外，此手術將同時影響捐贈者、受贈者及主要家屬的健康，因此醫護人員必須深入了解他們的經驗與感受，以作為臨床照護的實證基礎。 Living donor liver transplantation is a treatment choice for end-stage liver disease patients who face a shortage of currently available donated livers. The decision process involved in living donor organ donation has been described as a complicate process within the family of the patient. Donors have expressed willingness to donate a part of their own living liver in order to ensure the health of a loved one or relative when such a proposition was raised by the attending physician. Such decisions were taken even in the face of certain struggle, fear and ambiguous feelings. Donation decisions may be reinforced through feelings of confidence and trust in the physician and positive evaluations of the risk to donor health of making a 'living' donation. Necessary surgery will impact not only the recipient and donor but also family members. Staff on the transplantation team should make greater efforts to explore perceptions and concerns within families of living donors in order to deliver effective evidence-based care

Expertadvice on the diagnosis and intervention of Chinese developmental dyslexia

发展性阅读障碍是一种以儿童阅读能力显著落后于年龄和智力应有水平为主的障碍，属于具有遗传基础的神经发育性障碍。目前国内对发展性阅读障碍的评估、诊断与干预多出现在科研场合，临床诊疗和教育性质的应用明显不足。专家意见采用专家书面反馈意见和视频会议讨论的形式，以发展性阅读障碍的病因学基础为指导，对发展性阅读障碍的临床表现、诊断流程及干预原则等形成统一意见，旨在为相关专业领域医师和康复专业人员提供参考和帮助，亦为开展对发展性阅读障碍的教育性干预活动提供参考。</p