50 research outputs found
研究图书馆数字资源建设的转型与发展——以中国科学院文献情报系统为例
[目的/意义]旨在对研究图书馆数字资源建设转型与发展,特别是开放资源触发的第二次转型与发展进行总结,以探索研究图书馆数字资源建设的未来发展方向。[方法/过程]以中国科学院文献情报系统为例,梳理其数字资源建设实践与成效,并对今后发展做出预期——以综合科技资源、开放资源建设为转型基础,以细粒化的知识关联与呈现为发展目标。[结果/结论]研究图书馆在数字资源建设转型时会遇到诸多问题,提出以下建议:①制定明确的数字资源建设方案;②合理投入经费、人力和技术;③明确开放资源使用权益,积极推动开放获取;④加强开放资源建设的馆际合作与共享;⑤加强知识资源组织的跨界合作。</p
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目的:为借助分子影像技术提高抗肿瘤药物研发效率、降低研发成本提供参考。方法:以“分子影像技术”“药物研发”“肿瘤诊断”“生物标志物”等为关键词,通过检索和筛选中国知网、中国国家图书馆、PubMed、WebofScience等数据库收录的2017年4月以前发表的分子影像技术用于抗肿瘤药物研发的最新文献,进行整理、归纳和综述。结果与结论:近年来分子影像技术已取得重大进展,正越来越广泛地应用于抗肿瘤药物研发,并在药物生物分布标志物(药物由血液循环运送到体内各脏器的过程)、药效学生物标志物(药物对机体的作用及作用机制)、疾病生物标志物(用于疾病诊断、判断疾病分期或者用来评价新药或新疗法在目标人群中的安全性及有效性)及患者选择生物标志物(识别可能对治疗有反应的患者,指导治疗)等方面发挥重要作用。分子影像技术的成功应用,有望提高抗肿瘤药物开发全链条的效率和收益,其潜在价值有待进一步开发。国家科技部重点专项项目(No.2017YFA0205200):国家自然科学基金资助项目(No.81101101、81422023、51273165、U1505221);教育部科技重点项目(No.212149);教育部新世纪优秀人才支持计划(No.NCET-13-0502
“秤砣虽小压千斤”——解析金属离子在纳米药物自组装中的功能设计
目前,化疗的最大障碍是化疗药物在杀死癌细胞的同时对人体正常细胞,尤其是免疫细胞造成损伤.将化疗小分子药物特异性地递送到肿瘤部位,从而提高疗效并降低其毒副作用是亟待解决的现实难题.纳米药物主要由活性药物分子和递送系统(即药物载体)组成,是纳米材料或纳米颗粒在医学中最新发展起来的应用形式.由于其颗粒
光动力抗菌纳米制剂研究进展
新兴的光动力抗菌疗法是无创激发式治疗手段,主要利用近红外光作为光源,激活富集在病灶部位的光敏剂并产生活性氧自由基,最终实现对目标病菌的杀伤作用。相对比与传统的抗生素治疗,光动力抗菌疗法具有创伤性小,副作用低,不易产生耐药性等优点,在抗菌治疗方面有很大临床应用前景。随着生物材料与纳米医学技术的发展,小分子光敏剂纳米功能化后其生物兼容性和生物安全性得到优化,量子产率和病灶部位富集率显著提升,为其临床应用提供了新思路。本文结合小分子光敏剂纳米化策略方法实例,综述了纳米技术在光动力抗菌疗法的应用和发展
Investigation of Relative fMRI Signal Intensity and Its Spatial Distribution with Combination of Multiple Linear Regression and General Linear Test
目的 :探讨多重线性回归分析和一般线性 (GLT)检验在fMRI数据处理中的应用。材料和方法 :采用多重线性回归和GLT技术分析了一组复杂运动与简单运动的功能磁共振成像数据 ,并与传统互相关分析结果进行比较。结果 :采用互相关分析 ,选用不同的阈值得出了完全不同的结论 ; 而采用多重线性回归和GLT则不需要主观设定域值 ,并可对复杂与简单两种运动任务的激活强度进行定量比较 ,表明各脑区不同程度地参与两种运动任务 ,可被看作有一定等级的平行加工系统。结论 :与传统互相关分析相比 ,本研究的方法更为客观 ,并适合于定量分析两种不同任务所激活的脑活动的差异
安全Linux操作系统审计子系统的设计与实现
审计系统作为安全操作系统的一个重要组成部分,对于监督系统的正常运行,保障安全策略的正确实施,构造计算机入侵检测系统等都具有十分重要的意义。本文旨在论述审计系统的设计原则和具体实现方法,内容组织如下:首先介绍了计算机领域的安全现状及流行的攻击手段,这些背景信息使我们构造安全系统时具有明确的针对性;美国国防部的可信计算机评测标准(TCSEC)是目前公认的设计开发安全产品的重要指导,从它规定的各安全级别的主要特性中,我们可以了解安全系统的设计实现要求。WindowsNT和Solaris2.x都是目前主流的服务器操作系统,分析它们已有的安全审计模块,对于我们的设计有很强的指导作用,从中可以获得有益的思路和可借鉴的处理办法。在此基础上叙述基于Linux核心开发B2级安全操作系统的总体框架,并阐明审计与可信安全基(TCB)其它各部分的协同关系。然后,在审计系统的详细设计部分,着重论述审计子系统的结构模型、审计策略设定、功能模块的功分和具体实现以及审计自身的保护等,其中涉及Linux内核的重要概念,以及为审计安全相关命令而对它们所做的改造等,也进行了详细分析和描述,并给出最终的安全操作系统中的属层界面。接着,论述审计数据对于系统安全性的意义,举例说明了审计数据在入侵检测中的应用。最后,提出了几个需要进一步思考的问题,如审计数据的选择、压缩、加密和网络审计。Audit is a fundamental component of any secure operating system. It will be a great assistant to safeguard the running system, ensure the practice of security policies and build intrusion detection systems. In this paper, we mainly discuss the design and implementation of an auditing system. Structure of the contents is a s follows: Firstly, background of computer security area and some typical attacks are introduced, which will show us a clear direction when we develop a secure system. Trusted Computer System Evaluation Criteria of US DoD is a well-known guideline on security designing, from characters of each security level it specifies, we can set up the security requirements of our own. NT and Solaris2.x are both popular today as server operating system, the analysis of their auditing mechanism will give us some references and valuable clues or tips in our work. Our target is to develop a secure operating system based on linux kernel at B2 level, so the entire architecture and the cooperative relationships between auditing and the other parts of Trusted Computing Base are illustrated. After that, in the detailed design and implementation part, we focus on some issues including the audit model, decision of auditing policies, division of functional modules and the comprehensive implementation, the protection of audit itself is presented as well. Some concepts of linux kernel utilized by auditing system and the modifications of security relevant applications are also described. Interfaces of auditing subsystem in the whole operating system are represented as the final result. In the next part, we talk about intrusion detection and the contributions made by audit records. Lastly, we bring out some future works such as the selection of audit data, employ of compression and encryption, and network-based auditing
信号采集及频谱显示方案的研究与实现
文章讨论了在嵌入式领域实现信号采集及频谱显示的两个常用方案:数字信号处理器(DSP)方案和现场可编程门阵列(FPGA)方案。综合分析了这两种方案的优缺点。详细介绍了具体的FPGA实现方法。系统采用模块化设计,所有的功能模块都用Verilog HDL语言描述,具有自主的知识产权。仿真综合结果表明,系统能满足高速信号采集和频谱显示的要求
參與「學前資優幼兒多元智能與問題解決方案」幼兒語文特質之研究
[[abstract]]The purpose of this study was to investigate the verbal characteristics of the talented preschoolers. The subjects included the preschoolers who joined the screening session of identifying gifted young children for multiple intelligences (MI) and problem solving (PS) program. The data were collected from three domains: a. the scores of the standardized intelligence test, b. the observation from the observation activities, c. the performance during reading a wordless book activates and the verbal characteristics during the process of learning. There were some several brief conclusions by analyzing the comparative outcome:
1) The scores of the standardized intelligence test and the performance of the reading a wordless book activity of the talented and the normal preschoolers’ were significantly different.
2) Comparing to the performance intelligence, the verbal intelligence of the preschoolers was much easier to be observed by the parents and preschool teachers during the daily life.
3) The scores of the standardize test, the observation during the observation activate and the performances of reading a wordless book activates of the other talented groups and the verbal talented (VT) group were no significant difference. From the commendatory list of the program, many talented preschoolers were recommended two different talents; one of the talents was verbal talent.
4) During the process of learning, the VT group revealed many excellent verbal characteristics. From the observation, the qualitative evaluation, the portfolio assessment and the analyzing of the discourse in the class, the results exposed the verbal ability of the VT group were above the normal preschoolers. Because the performances of the VT group and other talented groups were similar, the results of study could agent the most talented preschooler of the MI & PS program.
By analyzing the outcomes and conclusions, further limitations and educational implications of this study would be discussed.
器件变形对倒梯形脊波导传输特性影响的研究
针对脊波导器件在使用中产生的各种变形,采用Matlab环境下的有限元PDE工具箱进行了二次编程,求得错位变形和不同受力变形时的传输特性。数值分析结果表明:错位变形使脊波导截止波长变长,单模带宽增大程度小于2%,对于脊波导传输特性影响较大的是双边受力变形,当变形达到10%时,其特性变化超过10%,在使用中应引起重视
A study on motorcycle users' mode transfer preference to electric bicycles
新世代運輸發展正面臨空氣污染與環境能源兩大重要課題,電動車輛發展亦於此時受到重視。電動腳踏車因技術需求較電動汽車與電動機車低,已成為我國電動車輛中較容易發展的技術。台灣都會區機車污染問題嚴重,在過去推行電動機車效果不彰的情形下,電動腳踏車以其特性與機車較相近之優勢,有成為機車之替代運具的潛力。因此本研究以居住於台北市的機車使用者為研究對象,利用個體選擇理論與敘述性偏好調查法,了解機車使用者選擇改用電動腳踏車之偏好情形。
本研究主要透過實驗設計與問卷調查以得知影響選擇電動腳踏車之重要因素與敘述性偏好資料。問卷內容包括電動腳踏車之基本特性、假設情境組合之運具偏好、機車使用者現況、受訪者基本資料等四部分。調查結果顯示,最有可能影響個人選擇使用電動腳踏車之因素,依序分別為「銷售價格的高低」、「充電後可行駛的距離」、「充電與維修地點的方便性」、「充電時間的長短」、「行駛速度的快慢」、「使用與維修成本的多寡」、「爬坡性能可否滿足需求」等;總言之,價格與性能是機車使用者轉用電動腳踏車的最重要因素。
所蒐集之敘述性偏好資料用以對二項羅吉特模式進行校估,過程中發現,售價在效用函數中並非與其他變數相互獨立。本研究嘗試將售價與最高時速相除,作為新的解釋變數,校估結果顯示該變數對模式之解釋能力良好。最佳模式則包含是否為學生之社經特性虛擬變數。透過校估之模式計算機車使用者選擇電動腳踏車的機率,在所擬定之接近現況的情境下為18.87%。若無政府力量之配合,僅電動腳踏車廠商與業者於外在環境限制下就技術能力可及範圍內發展,選擇機率可增加至44.01%。當電動腳踏車各項性能與相關使用環境皆達到理想最佳水準,機車使用者會選擇電動腳踏車的機率為61.97%。敏感度分析結果則發現,提供設置專用行駛空間以鼓勵機車使用者使用電動腳踏車,成效不如改善電動腳踏車之性能顯著,因此要提高選擇電動腳踏車的機率,改善電動腳踏車本身的性能方為較有效之作法。最後,電動腳踏車定位應以短途旅次與接駁運具之用,為有效解決都會區機車污染問題,未來應繼續發展與推廣電動機車。 Electric bicycles have been developed recently in Taiwan to help mitigate air pollution problems. In Taiwan’s metropolitan areas, air pollution from mobile sources is serious. Electric bicycles have the potential to be the substitute for motorcycles because of their good price and performance. This study employed discrete choice theory and stated preference (SP) survey method to learn about Taipei’s motorcycle users’ mode transfer preference to electric bicycles.
A comprehensive questionnaire survey was undertaken to find out major factors of mode transfer from motorcycles to electric bicycles. They are price, range per recharge, convenience of recharge and maintenance, recharge time, speed, operating and maintenance cost, climbing ability, and so on. It implies that price and performance characteristics of electric bicycles are the most important factors.
Stated preference data is used to calibrate binary logit model. Price divided by speed was employed for a better model. The optimal model employed a dummy variable “student or not”. The probability of switching to electric bicycles by motorcycle users is 18.87% in current condition. It will reach 44.01% if electric bicycle manufacturers’ technical improvements reach their best possible solution. The mode transfer probability will reach 61.97% if performance characteristics and riding environment of electric bicycles reach ideal conditions. Sensitivity analysis found that improving performance characteristics is more effective than providing exclusive lanes to encourage the using electric bicycles. Electric bicycles should be used for short distance trips or as short feeder mode. Electric motorcycles need to be promoted continually to better solve air pollution problems in metropolitan areas.中文摘要 I
英文摘要 II
目錄 III
圖目錄 V
表目錄 VI
第一章 緒論
1.1 研究背景 1
1.2 研究動機 4
1.3 研究目的 6
1.4 研究範圍 6
1.5 研究方法與流程 7
第二章 文獻回顧
2.1 電動腳踏車之特性與發展現況 9
2.1.1 電動腳踏車之分類 9
2.1.2 電動腳踏車之發展 11
2.1.3 電動腳踏車之特性 13
2.2 敘述性偏好法之回顧 14
2.2.1 敘述性偏好法之意義 14
2.2.2 敘述性偏好法之情境組合實驗設計 16
2.2.3 敘述性偏好法之優點與限制 17
2.3 電動車輛運具選擇之相關文獻 18
第三章 模式理論概念
3.1 個體選擇理論 23
3.2 效用函數之校估與應用 25
3.3 效用函數之變數組成 26
第四章 問卷設計與資料分析
4.1 問卷設計與調查 29
4.1.1 問卷內容 29
4.1.2 實驗設計 30
4.1.3 調查作業概況 37
4.2 問卷調查樣本分析 37
4.2.1 受訪者社經特性分析 37
4.2.2 受訪者運具使用特性分析 42
4.3 影響受訪者選擇使用電動腳踏車之因素 44
4.4 受訪者選擇改用電動腳踏車之意向 50
第五章 模式校估與分析
5.1 模式建構與校估 53
5.1.1 解釋變數之定義與說明 53
5.1.2 二項羅吉特模式校估 58
5.2 假設情境下之運具選擇機率 63
5.3 敏感度分析 66
5.4 電動腳踏車推廣之探討 69
第六章 結論與建議
6.1 結論 73
6.2 建議 75
參考文獻 77
附錄 7
