This thesis deals with the design and testing of the acoustic enclosure for the Inova hydraulic actuator. The purpose of this enclosure is the acoustic insulation of the actuator and its parts, to achieve better acoustic conditions when performing acoustic diagnostics on this device. The first part deals with the theoretical basis of acoustic enclosures, the possibilities of modelling of acoustic problems and market research in materials usable for enclosure construction. The second part deals with the analysis of actuator noise and the localization of noise sources in the laboratory. Subsequently, the choice of material and concepts of the acoustic enclosure was made. Then, the final design solution was selected. The final design solution was subjected to acoustic simulations to predict insertion loss and determine the dimensions of the enclosure. The manufactured enclosure was tested in a semi-anechoic chamber and finally on the Inova actuator. Finally, the measurement results and simulation results are compared with each other.

京都大学 / 0048 / 新制・課程博士 / 博士(地域研究) / 甲第19104号 / 地博第178号 / 新制||地||61(附属図書館) / 32055 / 京都大学大学院アジア・アフリカ地域研究研究科アフリカ地域研究専攻 / (主査)教授 重田 眞義, 教授 太田 至, 准教授 山越 言, 助教佐川 徹 / 学位規則第4条第1項該当 / Doctor of Area Studies / Kyoto University / DGAM

Enclosure design is the process of creating a package that will support and protect enclosed circuitry. Electronic enclosures are used in almost all industries, such as aerospace, automotive, naval, computer, toy, etc. Many designers use computer aided design (CAD) packages to aid them in creating these enclosures. Enclosure creation involves a working knowledge of the physics behind electrical and mechanical systems. Each of these engineering disciplines has separate CAD packages with their own set of rules, programming language, and interfaces. This creates a barrier for communication flow between electrical CAD (ECAD) and mechanical CAD (MCAD). The purpose of this thesis is to overcome the communication barrier by effectively transferring the knowledge contained in the ECAD package to the MCAD package, and use this information to aid in the electronic enclosure design process.

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The work presented in this thesis was motivated by the need for an accurate modeling approach for the acoustic response in a non-rigid-wall enclosure. The acoustic response in any enclosure is determined by the boundary conditions at the interior surface of the enclosure walls, and the types of sources present. The analyses presented in this thesis assumed that the sources were either at the surface of the enclosure, or interior to the enclosure walls. Three different analytical modeling approaches were investigated and presented in this thesis for the acoustic response in a rectangular enclosure. A reference model assumed that the walls of the enclosure were rigid, corresponding to an infinite acoustic impedance boundary condition. The acoustic pressure response was expressed in terms of the characteristic rigid wall acoustic modes of the enclosure. The second modeling approach used a finite acoustic impedance boundary condition to model the influence of non-rigid walls on the acoustic response. The third modeling approach treated the vibration of the enclosure walls as additional sources which were constructed from the in vacuo structural modes of the enclosure. The acoustic pressure was expressed in terms of the rigid-wall acoustic modes. High-dimensional state variable and transfer function models are presented, along with discussions of their validity and performance as model parameters vary. The frequency response functions generated using these three models were compared to the actual acoustic frequency response function obtained experimentally for a non-rigid-wall, plexiglass enclosure. It was found that the finite impedance model generated an acoustic response which best matched that of the actual acoustic response in magnitude and frequency; however, further development of this model is needed to account for structural resonances of the enclosure. / Master of Science

The thesis of this project is to develop a language of architecture for the design of a rural house. Parameters for this language are specified through program, ideas about living in a country home, and the importance of integrating the building with its site. The parameters are reaffirmed through the materials and elements of architecture. In order to develop a cohesive language, four houses have been designed for four different sites. Each house implements the specified parameters in a manner appropriate to the setting of the surrounding landscape. The houses themselves become a transition between the inside and the outside and between the natural and the man-made. Thus this thesis is: Four Houses - A Language of Transition from Earth to Sky. Our experience-space is necessarily in conflict with the space of nature. The space that nature offers us rises above the ground and is oriented entirely towards the earth's surface. The contrast between the mass of the earth below and the space of the air above, which meet at the surface of the earth, is the primary datum of this (experience) space. Dom H. Van Der Laan, "Architectonic Space" (E.J. Brill, 1983), p. 5 / Master of Architecture

This thesis focuses on adaptive feedback control for low frequency acoustic energy absorption in acoustic enclosures. The specific application chosen for this work is the reduction of high interior sound pressure levels (SPL) experienced during launch within launch vehicle payload fairings. Two acoustic enclosures are used in the research: the first being a symmetric cylindrical duct and the other being a full scale model of a payload fairing. The symmetric cylindrical duct is used to validate the ability of the adaptive controller to compensate for large changes in the interior acoustical properties. The payload fairing is used to validate that feedback control, for a large geometry, does absorb acoustic energy. The feedback controller studied in this work is positive position feedback (PPF) used in conjunction with high and low pass Butterworth filters. An algorithm is formed from control experiments for setting the filter parameters of the PPF and Butterworth filters from non-adaptive control simulations and tests of the duct and payload fairing. This non-adaptive control shows internal SPL reductions of 2.2 dB in the cylindrical duct for the frequency range from 100 to 500 Hz and internal SPL reductions of 4.2 dB in the full scale fairing model for the frequency range from 50 to 250 Hz. The experimentally formed control algorithm is then used as the basis for an adaptive controller that uses the collocated feedback signal to actively tune the control parameters. The cylindrical duct enclosure with a movable end cap is used to test the adaptation properties of the controller. The movable end cap allows the frequencies of the acoustic modes to vary by more than 20 percent. Experiments show that a 10 percent change in the frequencies of the acoustic modes cause the closed-loop system to go unstable with a non-adaptive controller. The closed-loop system with the adaptive controller maintains stability and reduces the SPL throughout the 20 percent change of the acoustic modes' frequencies with a 2.3 dB SPL reduction before change and a 1.7 dB SPL reduction after the 20 percent change. / Master of Science

My research provides a historical, geographical reading of land enclosure in the context of economic and agrarian crises in late imperial Russia. Using original records of Russian land deals that I obtained in the federal and provincial archives, I explore how the coalitions of landed nobility, land surveyors, landless serfs, and peasant proprietors used land enclosure as a conduit for coercive governance, accumulation of landed capital, or, in contrary, as a means of resistance. Through critical discourse analysis, I illustrate how the Russian imperial state and territories in the periphery were dialectically co-produced not only through institutional manipulations, resettlement plans, and husbandry manuals, but also through political and public discourses. I argue that land enclosure exploited practices of autonomous land management in the commune and furthered growing agrarian and economic crises in the countryside. The urban periphery became a strategic territory used for the accumulation of new wealth and displacement of two million peasant households, which accommodated capitalist development under the Russian Tsarist and, later, Soviet political regimes. Through this example, my research reexamines predominant assumptions about the land, territory, and crisis triad in Russia by positioning the rural politics of the late imperial period within the global context of land enclosure. At the same time, by focusing on the historical reading of territory from the Russian perspective, this study introduces a more nuanced alternative to the traditional colonial territory discourse often found in Western interpretations. / PHD / My research provides a historical, geographical analysis of land enclosure in the context of economic and agrarian crises in late imperial Russia. Using original records of Russian land deals that I obtained in the federal and municipal archives, I explore how the coalitions of landed nobility, land surveyors, landless serfs, and peasant proprietors used land enclosure as a conduit for coercive governance, accumulation of landed capital, or, in contrary, as a means of resistance. Through critical discourse analysis, I illustrate how the Russian imperial state and territories in the periphery were dialectically co-produced not only through institutional manipulations, resettlement plans, and husbandry manuals, but also through political and public discourses. I argue that land enclosure exploited practices of autonomous land management in the commune and furthered growing agrarian and economic crises in the countryside. The urban periphery became a strategic territory used for the accumulation of new wealth and displacement of two million peasant households, which accommodated capitalist development under the Russian Tsarist and, later, Soviet political regimes. Through this example, my research reexamines predominant assumptions about the land, territory, and crisis triad in Russia by positioning the rural politics of the late imperial period within the global context of land enclosure. At the same time, by focusing on the historical reading of territory from a Russian perspective, this study introduces a more nuanced alternative to the traditional territory discourse often found in Western interpretations.

<p>When breeding wild species in captivity, the animals may gradually become more adapted to captivity and therefore less suited for reintroduction which is the ultimate goal for some species. This study measured the activity budget of European bison (<em>Bison bonasus</em>) in six enclosures in Sweden with the aim to find out how the characteristics of the enclosures – with and without pasture - influenced the activity budget. The results show that there were significant differences in the activity budget, i.e. the activity was higher in the enclosures with pasture than in enclosures with barren ground. However, since barren enclosures were smaller than naturalistic, it was not possible to exclude the effect of size. Judged from observations of bison in the wild, there seems to be a direct correlation between food availability and ranging, indicating that enclosure characteristics affect activity more than size. The bison foraged differently in the two enclosure categories, but the total amount of time spent on feeding did not differ. A feeding enrichment experiment showed to have more positive effects in the barren enclosures than in the naturalistic ones, as the amount of time of inactivity decreased in the former. Since the genetic characteristics of all Swedish bison are very similar, the differences between the two enclosure groups indicate that the animals still have the ability to respond appropriately to improved environmental quality. Hence the next step in the assessment of the suitability of these bison for release would be to study them during an acclimatisation program.</p>

When breeding wild species in captivity, the animals may gradually become more adapted to captivity and therefore less suited for reintroduction which is the ultimate goal for some species. This study measured the activity budget of European bison (Bison bonasus) in six enclosures in Sweden with the aim to find out how the characteristics of the enclosures – with and without pasture - influenced the activity budget. The results show that there were significant differences in the activity budget, i.e. the activity was higher in the enclosures with pasture than in enclosures with barren ground. However, since barren enclosures were smaller than naturalistic, it was not possible to exclude the effect of size. Judged from observations of bison in the wild, there seems to be a direct correlation between food availability and ranging, indicating that enclosure characteristics affect activity more than size. The bison foraged differently in the two enclosure categories, but the total amount of time spent on feeding did not differ. A feeding enrichment experiment showed to have more positive effects in the barren enclosures than in the naturalistic ones, as the amount of time of inactivity decreased in the former. Since the genetic characteristics of all Swedish bison are very similar, the differences between the two enclosure groups indicate that the animals still have the ability to respond appropriately to improved environmental quality. Hence the next step in the assessment of the suitability of these bison for release would be to study them during an acclimatisation program.