Following large rain events, excess flow in sanitary sewers from inflow and infiltration (I/I) cause sanitary sewer overflows (SSO), resulting in significant problems for Pinellas County and the Tampa Bay area. Stormwater enters the sanitary sewers as inflow from improper or illegal surface connections, and groundwater enters the system as infiltration through cracks in subsurface infrastructure. This pilot study was designed to develop methods to separate and quantify the components of I/I and to build a predictive model using flowmeter and rainfall data. To identify surface inflow, daily wastewater production and groundwater infiltration patterns were filtered from the flow data, leaving a residual signal of random variation and possible inflow. The groundwater infiltration (as base infiltration, BI) was calculated using the Stevens-Schutzbach method, and daily wastewater flow curves were generated from dry weather flow (DWF) data. Filtered DWF values were used to construct a range of expected residuals, encompassing 95% of the variability inherent in the system. Filtered wet weather flows were compared to this range, and values above the range were considered significant, indicating the presence of surface inflow. At all 3 flow meters in the pilot study site, no surface inflow was detected, and the I/I was attributed to groundwater infiltration (as BI). Flow data from 2 smaller sub-sewersheds within the greater sewershed allowed analysis of the spatial variability in BI and provided a method to focus in on the most problematic areas. In the sub-sewershed with the shallowest water table and most submerged sanitary sewer infrastructure, an average of 56% of the average daily flow consisted of groundwater, compared to 44% for the entire study site. Cross-correlation analysis suggests that rain impacts the water table for up to 9 days, with the highest impact 1 to 3 days after rain events, and the water table, in turn, impacts infiltration for up to 6 days. The highest correlation between rainfall and infiltration occurs 3 to 5 days after a rain event, which corroborates observations from Pinellas County that severe flows to the reclamation facility continue for 3 to 5 days after severe storms. These results were used to build a linear regression model to predict base infiltration (per mile of pipeline) during the wet season using the previous 7 days of daily rainfall depths. The model tended to under-predict infiltration response to large storm events with a R2 value of 0.52 and standard error of regression of 5.3. The results of the study show that inflow can be detected using simple time series analysis instead of traditional smoke and dye testing. In this study site, however, groundwater infiltration is the only significant source of I/I. Additionally, water table and sewer invert elevations serve as useful indicators of potential sites of groundwater infiltration. Infiltration can be modeled as a function of the previous 7 days of rainfall, however simple linear regression cannot fully capture the complexity of the system response.

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This thesis deals with mathematical modelling of water flow through the safety object. It explains the principle of mathematical modelling and its laws. There is also present-ed the mathematical models used by numerical modelling. The results of mathemati-cal model Koryčany are included in this thesis compared with hydraulic calculations and physical model.

This thesis deals with the addition of flood protection measures in the Salašský potok basin. Working closely related to the previous bachelor thesis on Flood protection in the Salašský potok basin. Detail deal with left tributary Salašky - Modranský potok -which runs through the town Modrá, to be occupied by 6 small cascade of water reservoirs. The work is divided into two parts. The first part describes the actual parameters of the tanks and their assessment of the possible spill-over and is solved their overall transformational effect in the basin. In the second part of the thesis dealt with the tank as a semi tank in response to N-leté water and searched their design parameters.

Following large rain events, extraneous freshwater contributions known as inflow and infiltration (I/I) bypass the storm sewer and enter the sanitary sewer system. In areas with a high water table, like Pinellas County and the surrounding Tampa Bay area, a majority of the wastewater infrastructure is submerged year round exacerbating the rate of groundwater infiltration. This excess flow overloads the existing wastewater infrastructure leading to sanitary sewer overflows (SSOs). These SSOs result in serious problems for municipalities and utilities across the country. This study was performed in order to assist Pinellas County Utilities in rehabilitating their southern sewer system. To do this, 59 sub-basins across 8 sewer zones were monitored through Pinellas County’s Phase 1 Flow Monitoring Program accounting for over 150 miles of gravity pipe. For each sub-basin, a flow meter was utilized to measure the flow from May to October, 2017. This data was analyzed to separately quantify the amount of infiltration and inflow in each sub-basin, respectively. Once quantified, a Severity Index (SI) was developed in order to give each sub-basin a score from 1-100 as it relates to the condition of the gravity mains in the sub-basin. The SI was a function of locational features available with the use of a Geographic Information System (GIS), such as the distance to water bodies and the soil hydrologic group (SHG), as well as intrinsic pipe properties including the type of pipe material and the age of pipe. Once validated with additional flow monitoring data, the developed SI framework can serve as an additional tool utilized by Pinellas County Utilities to identify areas in need of sanitary sewer rehabilitation. Being that the model only requires easily attainable information, this approach is less time consuming and is inexpensive as compared to traditional flow monitoring efforts. The study also examined the required monetary investment by Pinellas County Utilities in order to abate the 17 sub-basins observed in the study with an infiltration rate greater than the marginal threshold put forth by the Environmental Protection Agency (EPA). The study indicated that gravity pipe rehabilitation does not make a significant impact on groundwater infiltration until at least 30% of the gravity pipes in the sub-basin are lined. This is due to the groundwater table submerging a majority of the wastewater infrastructure. Once this threshold is met, lining was observed to abate groundwater infiltration linearly. The results found that $4.4 million will be required to rehabilitate the affected sub-basins to a marginal rate of infiltration and reduce the flow to South Cross Bayou Water Reclamation Facility (SCBWRF) by an average of 0.72 mgd (million gallons per day). On an annual basis, this reduction in flow will result in approximately $650,000 in treatment costs savings.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19233号 / 工博第4068号 / 新制||工||1628(附属図書館) / 32232 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 中川 一, 教授 藤田 正治, 准教授 川池 健司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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Creating websites today is not easy as it seems, therefore it is important to know the essential principle when developing new product for users. Knowing the essential principles is not enough, you will also need to know about what users think and feel is important on a website such as Stack Overflow. It is a question-and-answer website where it offers users the ability to post questions and receive answers from other users that uses the same website. This study will identify what is important for young adult developers on the website Stack Overflow and what they think, and feel is required in terms of usability on the website. In this study there will be a theoretical framework and it includes different aspects of usability: learnability, comprehensibility, navigation, flexibility, and discoverability. This theoretical framework has been created to be able to identify what is important for young adult developers on the website Stack Overflow. By using this theoretical framework, we can setup the data collection method which is interview and think-aloud-test. As for analysis of the data, content analysis has been used to analyze the results and the study reached its conclusion. The conclusion is that on a website like Stack Overflow, navigation, flexibility, and comprehensibility are the important aspects for young adult developers.

Att tillgodogöra sig information och sprida den vidare har i alla tider varit väsentligt för att vi skall kunna utvecklas och fungera tillsammans på jobbet och i övriga relationer i vår vardag. Varje enskild individ exponeras dagligen för en stor informationsmängd, vilket ökar trycket på en bra och tydlig informationshantering. En skolmiljö är ett tydligt exempel där alla individer ständigt utsätts för ett ökande flöde av information både internt och extern. Avsikten med min uppsats har varit att identifiera och belysa de eventuella brister som finns i det interna informationsflödet på en medelstor gymnasieskola. Min undersökningsgrupp är pedagoger, elevvårds- och administrativ personal. Till att börja med undersökte jag hur alla uppfattade att informationsflödet fungerade på arbetsplatsen. Detta gjordes med en öppen fråga via e-post för att se om det fanns ett problem, hur omfattande problemet var och hur många det berörde. Baserat på de mest förekommande synpunkterna utformade jag en enkät med frågor och påståenden, om de förslag och önskemål personalen själva uttryckte utifrån min första fråga. Detta skulle ge mig förbättringsunderlag som personalen själva uttryckte För att verifiera vilka som har ansvar för hur informationen distribueras och genom vilka kanaler de ska presenteras intervjuade jag gymnasiesekreteraren på skolan. På så vis fick jag svar på en del av personalens frågor och ett bättre underlag för en analys och diskussion. Personalen upplever att informationen kommer helt ostrukturerat och i alla möjliga kanaler medan informationsansvarig tydligen har en plan för hur informationen distribueras. Information om information kunde säkert eliminera dessa problem. En inventering av vad som ska distribueras i vilken kanal skulle underlätt för alla. Med tanke på att det finns sjutton kanaler, så är det lätt att information hamnar i fel eller för många kanaler samtidigt. Respondenterna hade många funderingar och bra förslag på förbättringar. Tydligast är att det saknas information om informationen. Känslan av att informationsflödet var ostrukturerat var en återkommande synpunkt. Ofullständig information var ett annat dilemma som många irriterar sig på eftersom informationen hela tiden måste ändras.Undersökningen gav bra förslag på hur man kan förbättra informationsflödet och dess struktur för att alla berörda skall kunna tillgodose sig den information de behöver på ett enkelt och hanterbart sätt. Informationsträd, sökfunktioner och ett intranät var några av förslagen på förbättringar. / Spreading and collecting information is and has always been essential in order to communicate and cooperate on daily basis in a society like owns today. All individuals are being exposed to a large amount of information daily. This increases the demand for reliability and accuracy of the information and also the source that distribute the information. In an environment such as a school both pupils and personnel are exposed to a constant flow of information from both external and internal sources. The purpose of this study was to illustrate and identify the possible and in some cases obvious shortcomings in the internal flow of information in a medium sized upper secondary school. My group of interest have been educationalists, student council personnel and administrative personnel. Initially, I sent out a questionnaire determine general opinion of the flow and distribution of information in our school. Based on the answers, I then designed a questionnaire with more specific and detailed questions about the requirements and complaints my colleagues had expressed initially. The crux after problems seems to be the flow of information is somewhat unstructured and to some extent incomplete. To substantiate where the responsibility lies in distributing information and through which channels they are allocated, I interviewed the school secretary. Thus, I got answers to most of my colleagues questions and a robust foundation for my analysis and ultimately, my discussion. Finally I approached management to interview the person in charge of these questions and how they experienced the situation. My study resulted in many useful suggestions of how to eliminate obsolete and superfluous channels in order to get the most accurate and precise information provided.

Control-flow hijack attacks on software exploit vulnerabilities in the software’s memory handling. Over the years, various security mitigations have been developed to counter these attacks. However, compatibility issues have hindered the adoption of such measures in some legacy systems. This thesis focuses on the case of the legacy DOS system and examines whether a DOS system running the DOS/4GW protected mode extender can provide control-flow protection against an attack exploiting a buffer overflow vulnerability in the well-known retro game Duke Nukem3D. To investigate this, three model programs were created, and designed with memory models that share memory layout characteristics with the target retro game’s executable. Experimental attacks were then conducted on these models, aiming to identify an effective attack vector for the target vulnerability. The underlying theory suggests that memory models that segregate application data into distinct memory segments could potentially safeguard against the demonstrated attack. However, attempts to implement such a memory model within an application proved unsuccessful. The challenge that remains is to prove the existence of memory models under DOSprotected mode that can effectively shield Duke Nukem 3D, or other legacy games, from the control-flow hijack attack demonstrated in this thesis.