<p>Internet access using IEEE 802.11 wireless local area networks has become very common. In home and office networks where voice, video and audio will be delivered, quality of service (QoS) support is essential so that customers can be offered video on demand, audio on demand, voice over IP and high-speed Internet access. In addition to the proliferation of WLAN hotspots, WLAN mesh networks are now being used as a cost-effective means for coverage extension and backhaul relaying between IEEE 802.11 access points (APs).</p> <p> In conventional IEEE 802.11, APs are always continuously powered using fixed wired connections. In future WLAN mesh networks however, wired power connections may not always be readily available, especially in Wi-Fi hotzone installations which cover expansive outdoor areas. In such cases, fixed power connections can often be replaced by a battery operated or solar powered design. For this reason, power saving on the AP is highly desirable for this type of application. Unfortunately, this is not possible since the existing IEEE 802.11 standard requires that APs remain active at all times.</p> <p> In this thesis, we propose and investigate a comprehensive framework for a power saving QoS-enabled access point (PSQAP), intended for use in solar and low power IEEE 802.11 infrastructure applications. An energy-efficient media access control protocol is proposed using the contention-based channel access mode for IEEE 802.11. When real-time flows are present, a PSQAP schedules its awakening/sleeping pattern in a manner that satisfies the delay and packet loss requirements for the admitted real-time flows. A dynamic connection-admission control algorithm is proposed for efficient management of wireless resources. We show that both background traffic and the synchronization of stations' transmissions due to AP's alternating between awake and sleep states can cause excess queuing and packet collision rate. These effects result in an increase in packet delay and power consumption at the mobile stations in contention-based channel access mode. We propose and investigate several scheduling methods for mitigating these effects. It is also shown that voice over IP over WLAN (VoWLAN) suffers a low capacity problem and high handset/AP power consumption. A novel adaptive voice packetization scheme is proposed which improves VoIP capacity and reduces power consumption. The work in this thesis is characterized by analytical models and evaluated through extensive network simulations to study and analyze the key performance aspects of the proposed framework and the associated protocols.</p> / Thesis / Doctor of Philosophy (PhD)

本文主要探討蔣中正於1930～1937年之間如何型範其建構現代國家的模式。此期間在完成北伐後對中共展開軍事圍剿，他試圖融合中國傳統社會控制方法與現代西方觀念，展開一連串政治、社會、經濟等層面的改革，從中體現了現代國家的建構過程。江西省作為對中共軍事圍剿的中心，在熊式輝主政下施行一系列地方政治改革措施，其中包含了許多傳統的中國社會控制方式，而正也體現了蔣中正其有關地方政治改革觀念。同時，江西省的農村與同時期中國其他省份農村，均面臨了嚴重的經濟與社會危機，江西農村在當時更成為毛澤東建立革命根據地並成功動員農民的大本營，並且展現了毛澤東建構現代國家的另一種模式。所以分析江西為何能夠成為中共進行武裝革命的重要根據地，以及其能成功動員農民的主要動力何在，成為理解蔣中正據以提出其著名的「三分軍事，七分政治」策略的重要原因。因此，江西省政府於1930年代進行一連串的地方政治改革，分析其方案內容以理解蔣中正對於地方政治改革與建構現代國家之間的關係。對蔣中正而言，進行地方政治改革的主要目的是為了擴張與強化國家對基層社會之基礎控制能力，借以強化對農村社會的控制。但為使改革成功而必須適應中國之國情，因此蔣中正採借了中國傳統帝國時期有關農村社會控制與動員的手段，例如保甲制度、團練與強調恢復傳統道德精神的新生活運動等。其後，蔣中正以江西省的實際作法與成功經驗作為其掌握國家權力後的具體施政參照，例如1939年對日抗戰期間國民政府毅然決定全面革新進行縣政制度，也反映了相同的政治改革邏輯。在蔣中正的政治改革理念中，不僅反映了傳統與現代性之間的掙扎、反抗與妥協，衝突、轉化與融合，並且有意或無意地採取了中國特有的習慣與制度，從而體現了現代性的多元特性。 / This dissertation focuses on the ideas and mode of how Chiang Kai-shek build the modern state in 1930-1937. In this period, he tried to integrate traditional Chinese social control methods and modern Western concepts, and launched a series of political, social, economic and other aspects of the reform. However, in the period of 1930-1937. Which embodies the construction of the modern state process. Jiangxi Province as the center of the Chinese military siege before 1935, Xiong Shi-hui implement a series of local political reform measures which contains many of the traditional Chinese social control, Chiang Kai-shek is the best embodiment of the concept of local political reform. At the same time, rural areas in Jiangxi Province and other provinces in China in the same period were facing serious economic and social crises. At that time, the rural areas in Jiangxi Province became Mao Zedong's revolutionary base areas and the headquarters where successfully mobilized the peasants, moreover, Mao Zedong to show the construction of a modern state of another model. Therefore, the analysis of why Jiangxi could become an important base for the armed revolution in China, its main motivation to mobilize the peasants, became an important reason for Chiang Kai-shek to put forward his famous "three points military, seven political" strategy. Therefore, the Jiangxi provincial government in the 1930s to carry out a series of local political reform, analysis of its program content to understand the Chiang Kai-shek for local political reform and the construction of the relationship between the modern state. For Chiang Kai-shek, the purpose of local political reform is to expand and strengthen the country's basic control of grass-roots level of social control, but to make the success of the reform must adapt to China's national conditions, so he adopted the traditional society of social control and mobilization means, such as the system of “Bar-jia”, “Tuan-Lian”(militia) and the new life movement which that emphasizes the restoration of the traditional moral spirit. The practices and successful experience of Jiangxi become an important reference after Chiang Kai-shek take the political power of nation, for example, he decided to conduct a comprehensive reform of the county system during the Sino-Japanese war in 1939, which that also reflects the same logic of political reform. In Chiang Kai-shek's ideas of political reform, not only reflects the struggle between tradition and modernity, resistance and compromise, bat also conflict, transformation and integration. At the same time, in his ideas had adopted China's unique habits and institutions intentionally or unintentionally, thus reflecting the characteristics of modernity multivariate.

Deep decarbonisation of road transportation is challenging. One of the most potentially beneficial approaches is electrification which is the subject of this PhD thesis. A widespread penetration of electric vehicles (EVs) across a large proportion of road transport demand is needed to realise the benefits of an electrified transport sector. However, this is dependent on overcoming significant barriers. This study performs a systematic analysis of how proven power charging technologies could be used to unlock the barriers to widespread electrification of road transportation. Various road transport sectors and type of journeys are explored including aspects of autonomous operations and novel wireless power transfer technologies. For each operation, a framework is proposed that allows the exploitation of current and potential future electrification technologies to enable shifting towards EVs. Based on that, simulation tools and methods are developed to calculate the power requirements of EVs and determine a suitable charging infrastructure. The additional power demand, electric load and the implications for the electricity supply network are explored. The total expenditure needed and the CO2 emission savings are also calculated for each investigated operation. Transitional strategies include the electrification of bus routes, refuse collection functions, home deliveries and aspects of autonomous operations for public transportation within the boundaries of the cities. In the long-term, focus is given on passenger cars and freight vehicles for both urban and inter-urban journeys. A nationwide adoption of all electrification strategies proposed in this thesis would increase the peak power demand of Great Britain by approximately 38 GW (72% of the current peak) and the electricity consumption by 180 TWh per year (45% of current consumption). The total capital cost required is calculated at £225 billion which is similar to the cost of other large infrastructure projects of the country. The impact would be a significant aggregate saving of approximately 2,000 MtCO2 between the numbers calculated for today's norms (2018) and those calculated for 2050.