Comparison of simulation-based schedule generation methodologies for semiconductor manufacturing

Although a number of approaches have been developed to schedule tasks or jobs in many different manufacturing environments, increasing manufacturing complexity continues to motivate the need for additional scheduling heuristic research and development. This is particularly true for semiconductor manufacturing operations, arguably the most complex manufacturing environment in existence. Simulation-based scheduling has shown recent promise as a means for developing schedules for dynamic, stochastic manufacturing environments. I investigate the potential advantages and drawbacks of using simulation-based scheduling in a complex job shop as motivated by a semiconductor wafer fab

Development of primary and secondary cell cultures from the lymphoid organ of Penaeus vannamei to study the replication cycle of white spot syndrome virus (WSSV)

Shrimp aquaculture is a booming agro-industry worldwide. Due to intensification of shrimp farming, pathogens emerged. Control of these pathogens especially viral pathogens is essential for a further expansion of this industry. Until now, the lack of shrimp cell lines has limited research on shrimp viral pathogens. In this thesis, primary and secondary cell cultures from the lymphoid organ of Litopenaeus vannamei were developed and the replication cycle of white spot syndrome virus (WSSV) was investigated in the secondary cell cultures from the lymphoid organ of Litopenaeus vannamei

A historical and sociolinguistic approach to language change in Mandarin Chinese: Corpus evidence for the development of YOU-MEI-YOU

This dissertation introduces corpus-based analyses of a syntactic construction in Standard Mandarin, YOU-MEI-YOU (or ‘have-not-have’)+VP, which is used to form perfective questions. The purpose of the study is to (i) find evidence for the claim that preverbal YOU-MEI-YOU, i.e. YOU-MEI-YOU found in the new construction, is grammaticalizing into an auxiliary unit, and (ii) to investigate its historical development, including the stage of development that it has reached and its distribution over time. Using data from two databases, the present study first looks at the percentage of preverbal YOU-MEI-YOU conveying a certain grammatical meaning, i.e. sentence type and aspect. Next, the study compares the percentage of three linguistic features of this construction, namely, the grammatical meaning(s) conveyed by preverbal YOU-MEI-YOU, the general types of complement it takes, and the specific types of VP complement it takes, between different 20-year periods. The study also makes a comparison of the frequency of use of preverbal YOU-MEI-YOU between different 10-year periods. The results of the first type of analysis show that preverbal YOU-MEI-YOU helps to form constructions conveying either grammatical meaning in the majority of the clauses, lending support to the claim that it is grammaticalizing into an auxiliary unit. The diachronic comparisons of the three features of the new construction indicate that preverbal YOU-MEI-YOU has reached Stage III as outlined in Heine (1993). The comparison of the frequency of use between different time periods shows no upward trend in the use of (auxiliary) preverbal YOU-MEI-YOU

The Potential Water Saved When USA Households Pay a Water Bill

A continuing problem for both American agriculture and our society is the shortage of usage water. This problem has become more acute as our population grows and as global warming and the demands of agriculture pushes government agencies to look for ways to save water. More efficient devices are now required and households have been asked to voluntarily restrict water usage. Although less wasteful irrigation methods have been introduced, the problem of inadequate water for agriculture has continued to grow. Interestingly, there is one area where millions of gallons of clean water are potentially wasted each year that has been entirely overlooked. There are hundreds of thousands of apartments, condos, and housing units in America where the household never pays a water bill. In fact, one could view these units as having ‘free’ water. In these cases, the occupant may use all the water they want with no penalty for wasting this valuable natural resource. This paper has an original model that attempts to estimate potential savings if these households received a water bill for their individual water usage. The authors use log-log model to estimate residential water demand. Data used in this analysis contains 8 metropolitan areas (Austin, TX; Boston, MA; Hartford, CT; Houston, TX; Las Vegas, NV; Minneapolis/St. Paul, MN; Orlando, FL; San Antonio, TX) and the data were collected from American Housing Survey 2013 Metropolitan Data. Results show that increasing the marginal price of water decreases water consumption by 8%. Since the average water consumption of households that pay a bill is 10,135.23 gallons per month, if the marginal price increases by $1, then the water consumption decreases by 779.2 gallons. Overall, a shift to complete volumetric pricing will decrease average household water consumption by 5282.8 gallons per month at existing water prices. Results also show measurable differences between cities. The marginal price is negatively related to the water consumption levels and positively related to the percentage of households with ‘free’ water. Advisor: Karina Schoengol

The Potential Water Saved When USA Households Pay a Water Bill

A continuing problem for both American agriculture and our society is the shortage of usage water. This problem has become more acute as our population grows and as global warming and the demands of agriculture pushes government agencies to look for ways to save water. More efficient devices are now required and households have been asked to voluntarily restrict water usage. Although less wasteful irrigation methods have been introduced, the problem of inadequate water for agriculture has continued to grow. Interestingly, there is one area where millions of gallons of clean water are potentially wasted each year that has been entirely overlooked. There are hundreds of thousands of apartments, condos, and housing units in America where the household never pays a water bill. In fact, one could view these units as having ‘free’ water. In these cases, the occupant may use all the water they want with no penalty for wasting this valuable natural resource. This paper has an original model that attempts to estimate potential savings if these households received a water bill for their individual water usage. The authors use log-log model to estimate residential water demand. Data used in this analysis contains 8 metropolitan areas (Austin, TX; Boston, MA; Hartford, CT; Houston, TX; Las Vegas, NV; Minneapolis/St. Paul, MN; Orlando, FL; San Antonio, TX) and the data were collected from American Housing Survey 2013 Metropolitan Data. Results show that increasing the marginal price of water decreases water consumption by 8%. Since the average water consumption of households that pay a bill is 10,135.23 gallons per month, if the marginal price increases by $1, then the water consumption decreases by 779.2 gallons. Overall, a shift to complete volumetric pricing will decrease average household water consumption by 5282.8 gallons per month at existing water prices. Results also show measurable differences between cities. The marginal price is negatively related to the water consumption levels and positively related to the percentage of households with ‘free’ water. Advisor: Karina Schoengol

Genome-wide analysis of overlapping genes regulated by iron deficiency and phosphate starvation reveals new interactions in Arabidopsis roots

Additional file 8. Co-expression relationships of the 97 differentially expressed overlapping genes induced by Pi starvation but repressed by Fe deficiency

A novel backfill material for roof supports in the cut-through entries of longwall mining

SažetakTo enhance underground mining safety, researchers developed high-water and fast-setting cement (HWFSC). HWFSC essentially consists of two components and can be mixed with large quantities of water. To determine its mechanical strength, a series of uniaxial compressive strength tests were conducted on HWFSC specimens with different water-to-solid ratios. Results indicate that peak strength declined significantly with the increase in W/S ratio, whereas residual strength increased gradually with this enhancement. The feasibility of backfilling cut-through entries with HWFSC is then evaluated through a case study. The LaModel program was used to assess the yielding of the fender pillar and the deformation of the cut-through entry. Results also show that the use of HWFSC to backfill the cut-through entry addressed complicated ground control problems effectively. Further analysis also suggested that HWFSC was the optimal backfill material in terms of both economic cost and roof support safety

Helmert Variance Component Estimation for Multi-GNSS Relative Positioning

The Multi-constellation Global Navigation Satellite System (Multi-GNSS) has become the standard implementation of high accuracy positioning and navigation applications. It is well known that the noise of code and phase measurements depend on GNSS constellation. Then, Helmert variance component estimation (HVCE) is usually used to adjust the contributions of di¿erent GNSS constellations by determining their individual variances of unit weight. However, HVCE requires a heavy computation load. In this study, the HVCE posterior weighting was employed to carry out a kinematic relative Multi-GNSS positioning experiment with six short-baselines from day of year (DoY) 171 to 200 in 2019. As a result, the HVCE posterior weighting strategy improved Multi-GNSS positioning accuracy by 20.5%, 15.7% and 13.2% ineast-north-up(ENU) components, compared to an elevation-dependent (ED) priori weighting strategy. We observed that the weight proportion of both code and phase observations for each GNSS constellation were consistent during the entire 30 days, which indicates that the weight proportions of both code and phase observations are stable over a long period of time. It was also found that the quality of a phase observation is almost equivalent in each baseline and GNSS constellation, whereas that of a code observation is different. In order to reduce the time consumption off the HVCE method without sacrificing positioning accuracy, the stable variances of unit weights of both phase and code observations obtained over 30 days were averaged and then frozen as a priori information in the positioning experiment. The result demonstrated similar ENU improvements of 20.0%, 14.1% and 11.1% with respect to the ED method but saving 88% of the computation time of the HCVE strategy. Our study concludes with the observations that the frozen variances of unit weight (FVUW) could be applied to the positioning experiment for the next 30 days, that is, from DoY 201 to 230 in 2019, improving the positioning ENU accuracy of the ED method by 18.1%, 13.2% and 10.6%, indicating the effectiveness of the FVUW.Peer ReviewedPostprint (published version