京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20546号 / 理博第4304号 / 新制||理||1618(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 早川 尚男, 教授 川上 則雄, 教授 佐々 真一 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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Price volatility is a consistent problem that affects all of the parties involved in the residential construction industry. The myriad factors that can have an impact on construction costs are such that it is extremely hard to anticipate upcoming changes in a timely and accurate way. When prices fluctuate during the course of a project, estimates become erroneous and completion of projects within expected budgets becomes difficult. Increasing prices typically leave contractors with the majority of the risk burden due to the enforceability of contracts that are likely to have been executed months prior. The risk associated with the owner's role primarily exists when prices decrease and they are required to make payments on pre-existing contracts that do not accurately reflect "actual" costs at the time of construction. The risk of price volatility needs to be managed. Numerous methods have been developed for managing the risk of price volatility. The various methods available are implemented based on the parties involved, the types of contracts being used, and the existing market conditions. Typical practices transfer the risk of price volatility to other involved parties, be it the owner, the contractor, subcontractors, or suppliers. However, no method has proven completely effective at removing the risks associated with price volatility. Involved parties need to utilize a combination of best practices to protect themselves. They need to coordinate and communicate with the other parties to ensure that the risk of price volatility is appropriately accounted for and managed throughout the construction process.

In the commercial construction industry, the problem of price volatility as it pertains to materials and labor is a consistent problem. The changing instability of market conditions presents a challenge for construction companies to accurately estimate and complete projects within budget. This volatility can lead to higher costs and more risk to suppliers, contractors, and owners which can cause financial distress for all parties involved in the construction process. As lump sum contracts are typically being used on many projects, the owners seem to have the upper hand and are forcing contractors to honor lump sum contracts even when prices increase significantly. Owners are also using their position to reap the benefits of price decreases by basing future work relationships with the contractor as an incentive to pass on any savings of price decreases. Volatility in construction will continue to be a risk that participants in the construction industry in Utah will face. Commercial construction projects will continue to be built as the population increases and as more buildings are needed to service other industries. Price volatility can be economically dangerous when price changes affect the assumptions on which the contract is based. While there is no proven method to remove the risk of price volatility, methods have been developed to control the risk participants are exposed to in various contracting methods. Contractors, owners, and suppliers need to coordinate with each other and use best practices that will distribute the risk to the party that has the capability to handle the risk.

An  important  task   during  the  construction  process  is  to  validate  the dimensions  and  properties  of  a  given  structure.  The  dimensions  like  for instance the thickness of a construction element should  be measured after finishing  building  it.  The  aim  is  to  compare  the  measured  value  with  the design  value   to  avoid   that   elements  do   not  correspond  to  the  input requirements.  Moreover,  the  measurements  are  helpful  to  analyse  the statistical    distribution    of    the    investigated    geometrical    property    by computing e.g. a histogram, which visualises the dispersion and  enable the calculation of the probability of failure for a specific structure or element.In  this  work,  a  shotcrete  layer  has  been  analysed  in  order  to  provide information  about  the  homogeneity  of  the  shotcrete  thickness  in  a  pre-determined  tunnel  section.  The  calculation  method  is  based  on  two  laser scans,  before  and  after  applying  the  shotcrete.  Due  to  the  construction process, the shotcrete layer will not be totally equal, which might be a safety problem. Especially, when  the shotcrete layer is thinner than  required and hence, the actual variation of the shotcrete must be considered and verified.To determine the statistical distribution, correlograms and histograms have been  computed  for  a  wall  area  in  a  tunnel  in  Southern  Sweden.  The correlogram shows the distance where the values have a correlation to each other  and  usually  this  distance  is  called  scale  of  fluctuation.  For  the  wall section, this scale of fluctuation has been calculated for the length (0.8m) as well  as  the  height  (0.8m).  Compared  to  the  original  sample  distance,  e.g. distance of the rock bolts, the variance for the calculation of the probability of failure might be reduced.

Lower stem nitrate concentration is used as a guide for fertilization of small grains in Arizona. The objective of this study is to determine if the timing of stem sampling has an appreciable effect on stem nitrate and corresponding fertilizer recommendations. Durum and barley were grown at the Maricopa Agricultural Center and lower stems were analyzed for nitrate from 3-leaf to maturity. Stem nitrate concentration varied considerably between the 3-leaf and 2 node stages, but thereafter was relatively constant and low (averaged 765 ppm). Stem nitrate increased after rain or N application on a few occasions, but not consistently. In this study, the timing of the stem sampling could have affected fertilizer recommendations before the 2-node stage, but after the 2-node stage, fluctuations in stem nitrate would have resulted in relatively minor differences in fertilizer recommendations.

Lower stem nitrate concentration is used as a guide for fertilization of small grains in Arizona. The objective of this study is to determine if the timing of stem sampling has an appreciable effect on stem nitrate and corresponding fertilizer recommendations. Durum and barley were grown at the Maricopa Agricultural Center and lower stems were analyzed for nitrate from 3-leaf to maturity. Stem nitrate concentration varied considerably between the 3-leaf and preboot stages, but thereafter was relatively constant and low (averaged 736 ppm). In this study, the timing of the stem sampling could have affected fertilizer recommendations before the pre-boot stage, but afterwards fluctuations in stem nitrate would have resulted in relatively minor differences in fertilizer recommendations.

Lower stem nitrate concentration is used as a guide for fertilization of small grains in Arizona. The objective of this study is to determine if the timing of stem sampling has an appreciable effect on stem nitrate and corresponding fertilizer recommendations. Durum and barley were grown at the Maricopa Agricultural Center and lower stems were analyzed for nitrate from 3-leaf to maturity. The lower stem nitrate concentration initially climbed from 3000 ppm at 3-leaf to 10,000 ppm around the 2-node stage. It then gradually declined from the 2-node stage until maturity when it fell to less than 3000 ppm In this study, the timing of the stem sampling would not have affected fertilizer recommendations, although considerable fluctuation in stem nitrate concentration was measured.

Soumise à une sollicitation sismique importante, une structure de génie civil peut être endommagée. Cela se traduit par l'apparition de fissures et donc une réduction de ses propriétés élastiques de la structure. Cependant, dans le cas d'un événement sismique d'amplitude inférieure, la variation observée est seulement transitoire. Elle consiste en une perturbation brutale de la fréquence et de l'amortissement suivie d'un recouvrement lent vers leurs valeurs initiales. Ce phénomène non linéaire de relaxation est appelé Dynamique Lente. Il s'explique par la fermeture progressive des fissures initialement présentes dans la structure et qui ont été ouvertes par la sollicitation. Nous avons observé en laboratoire que l'analyse de la Dynamique Lente dans une poutre avant et après son endommagement permet de détecter cette augmentation de la densité de fissures. La sensibilité différentielle des modes à une dégradation locale indique, de plus, une piste pour le développement d'une méthode de localisation de l'endommagement. L'étude de la Dynamique Lente que nous avons menée dans deux structures de génie civil a montré que nous pouvions également y détecter l'apparition de l'endommagement. Le suivi de l'amortissement de manière continue a mis en évidence une relation linéaire entre l'amortissement et l'intensité des vibrations ambiantes à la fois dans les poutres et les structures de génie civil. Nous expliquons celle-ci via l'application du théorème Fluctuation-Dissipation à ces systèmes. Les résultats en laboratoire et la proximité de l'expression de la relation avec les équations utilisées dans le cas de la Dynamique Lente suggère une dépendance de ce phénomène vis à vis de la densité des hétérogénéités dans le matériau composant la structure. De plus amples recherches sont cependant nécessaires afin d'expliquer complètement nos observations et ainsi pouvoir les utiliser dans le cadre de la surveillance des structures uniquement à partir de données de très faible amplitude. / During strong seismic loadings, a structure may be damaged. This results in the appearing of cracks and then a reduction of the elastic properties of the structure. The degradation remains only transitory in the case of smaller seismic events. It consists in a sharp disruption of both the frequency and damping followed by their slow recovery to their initial values. This non linear phenomenon is called Slow Dynamics. It is explained by the gradual closing of the cracks which were initially present in the material and which were opened during the loading. We observed in the laboratory that the analysis of the Slow Dynamics in a beam before and after it is damaged allows to detect the increase of the crack density. The different sensitivties of the modes regarding a local damaging indicates a track to develop a method to locate the damages. The study of the Slow Dynamics in civil engineering structures demonstrated the possibility to detect the damaging also in this kind of system. The continuous monitoring of the damping highlighted a linear relationship between damping and the intensity of the ambiante vibration in the case of both the beams and real case structures. We explain this relation by applying the Fluctuation-Dissipation to these systems. Laboratory results and the proximity of the expression of the linear relationship wit hthe equations used in the theory of the Slow Dynamics suggest a dependency of this phenonmenon on the density of heterogeneities in the structure. Further research is however required in order to fully explain our observations and thus, to use them to monitor the state of health of structures.

Water is vital to life, essential to the development of humanity in health, social and economic levels, having strategic importance to the productive sectors and thus playing a key role in generating wealth and ecosystem maintenance. The present study aimed to record the variability of electrical conductivity and temperature of groundwater in shallow wells, and estimate direct recharge of the Guarani Aquifer System, in your outcrop zones over a hydrological year, between October 2012 to September 2013. The survey was conducted in two adjacent watersheds of the river Vacacaí-Mirim, in the Santa Maria region, inserted in the Central Depression of Rio Grande do Sul, on the Paraná Sedimentary Basin edge. Was recorded the electrical conductivity, temperature and the fluctuation of water level in three monitoring wells, designated P05, P06 and P07, with depths of 31, 20 and 15 meters respectively. Pressure transducers were configured to perform readings of groundwater level and temperature, often from hour to hour, at 05 and 07 wells. There were 24 measurement campaigns, with fortnightly basis, the three monitoring wells, enrolling in the entire water column, conductivity and water temperature. There was obtained an amplitude variation of the water level in the order of 3.05 m in the well 05, in the highest position, in the order of 1.55 m in the well 06 in an intermediate position, while the well 07, located in alluvial plain, was only 0.82 m in saturated sedimentary rocks all year. For the electrical conductivity of groundwater were obtained yearly averages ranging from 35.9 to 58.8 μS/ cm in wells 05 and 06, while the well 07 yielded higher annual average of up to 106.5 μS/cm. The average temperatures of the water column in the monitoring wells showed a range of variation of 1.0 oC , 2.8 oC and 1.6 oC, correspondingly to the wells 05, 06 and 07. Regarding the estimation of the direct recharge of the aquifer, was used to Water Table Fluctuation method (WTF). Was estimated the recharge of 38.95% in the well 05, and 18.31% in 07 well, considering the total annual rainfall in the period of 1.887 mm. The estimated results of groundwater recharge were similar to those found in previous research. We observed the variability in temperature as the electrical conductivity of the groundwater, possibly related to the position occupied in the landscape wells, as well as characteristics of the constituent materials of the sandstones matrix, formers unconfined aquifer. / A água é uma substância vital para a vida, indispensável ao desenvolvimento da humanidade em todos os níveis da saúde, sociais e econômicos, tendo importância estratégica para os setores produtivos e, portanto, desempenhando papel fundamental na geração de riquezas e manutenção dos ecossistemas. O presente estudo teve como objetivos, registrar a variabilidade espaço-temporal da condutividade elétrica e da temperatura da água subterrânea, em poços rasos, bem como estimar a recarga direta do Sistema Aquífero Guarani, em sua zona de afloramentos, durante um ano hidrológico, de Outubro de 2012 a Setembro de 2013. A pesquisa foi realizada em duas microbacias contíguas do rio Vacacaí-Mirim, na região de Santa Maria, inserida na Depressão Central do Estado do Rio Grande do Sul, na borda da Bacia Sedimentar do Paraná. Registrou-se a condutividade elétrica, a temperatura e a flutuação do nível da água em três poços de monitoramento, denominados P05, P06 e P07, com profundidades de 31, 20 e 15 metros respectivamente. Foram utilizados transdutores de pressão configurados para realizar leituras de nível freático e de temperatura, com frequência de hora em hora, nos poços 05 e 07. Realizaram-se 24 campanhas de medição, com frequência quinzenal, nos três poços de monitoramento, registrando-se em toda a coluna de água, a condutividade elétrica e a temperatura da água. Obteve-se uma amplitude da variação do nível freático da ordem de 3,05 m para o poço 05 em posição mais elevada, da ordem de 1,55 m para o poço 06 em posição intermediária, enquanto que no poço 07, localizado na planície aluvial, foi de apenas 0,82 m, em rochas sedimentares saturadas o ano todo. Para a condutividade elétrica da água subterrânea, obtiveram-se médias anuais variando de 35,9 a 58,8 μS/cm nos poços 05 e 06, enquanto que no poço 07 obtiveram-se médias anuais mais elevadas, de até 106,5 μS/cm. As temperaturas médias da coluna de água nos poços de monitoramento apresentaram uma faixa de variação de 1,0oC, 1,6oC e 2,8oC, correspondentemente aos poços 05, 06 e 07. Com relação à estimativa da recarga direta do aquífero, utilizou-se o método Water Table Fluctuation. Estimou-se a recarga de 38,95% no poço 05, e de 18,31% no poço 07, considerando-se a precipitação pluviométrica total anual ocorrida no período, de 1.887 mm. Os resultados estimados de recarga subterrânea foram semelhantes aos encontrados em pesquisas anteriores. Registrou-se a variabilidade tanto da temperatura quanto da condutividade elétrica da água subterrânea, possivelmente relacionada à posição dos poços ocupada na paisagem, bem como às características dos materiais constituintes da matriz dos arenitos, formadores de aquífero livre.