MODELING AND SIMULATION OF A LEAN SYSTEM. CASE STUDY OF A PAINT LINE IN A FURNITURE COMPANY

Since they were first developed, lean methodologies have grown in importance and scope and have been applied in both manufacturing and service. However, determining how to transform a common manufacturing company into a lean one, as well as how to evaluate the future company, are challenges for both researchers and manufacturers. This paper presents a case study of a lean manufacturing implementation for the paint line system in a furniture company. A systematic method for execution is shown. In addition, a simulation model is constructed to evaluate the new system in comparison with the MRP system. The new system promises much improvement in terms of a resource’s utility and the system’s productivity.Lean Techniques, Simulation Model, Paint Line, Furniture Company.

Professor Text: University Fundraising Optimization

University fundraising campaigns are a unique type of cause-related marketing with its own challenges and opportunities. Campaigns like this typically last an extended period, such as five or more years, and goals exist beyond the dollar amount raised. These supplemental goals, such as awareness among potential future donators or brand reputation within the local community, are important to consider and strategize. There can also be unique limitations, such as requiring advertising specifically on recent large gifts or endowment programs. This research explores how machine learning techniques such as natural language processing can be used to optimize a fundraising campaign strategy, execution, and overall performance

Decreasing behavior of the depth functions of edge ideals

Let $I$ be the edge ideal of a connected non-bipartite graph and $R$ the base polynomial ring. Then $\operatorname{depth} R/I \ge 1$ and $\operatorname{depth} R/I^t = 0$ for $t \gg 1$. We give combinatorial conditions for $\operatorname{depth} R/I^t = 1$ for some $t$ in between and show that the depth function is non-increasing thereafter. Especially, the depth function quickly decreases to 0 after reaching 1. We show that if $\operatorname{depth} R/I = 1$ then $\operatorname{depth} R/I^2 = 0$ and if $\operatorname{depth} R/I^2 = 1$ then $\operatorname{depth} R/I^5 = 0$. Other similar results suggest that if $\operatorname{depth} R/I^t = 1$ then $\operatorname{depth} R/I^{t+3} = 0$. This a surprising phenomenon because the depth of a power can determine a smaller depth of another power. Furthermore, we are able to give a simple combinatorial criterion for $\operatorname{depth} R/I^{(t)} = 1$ for $t \gg 1$ and show that the condition $\operatorname{depth} R/I^{(t)} = 1$ is persistent, where $I^{(t)}$ denotes the $t$-th symbolic powers of $I$.Comment: 15 pages, 3 figure

Performance of Self-compacting Concrete with Stainless Steel Slag Versus Fly Ash as Fillers: A Comparative Study

Recently, stainless steel slag -a byproduct of manufacturing stainless steel is accepted as a cementitious material, the chemical characteristics of which are highly variant. This study reuses two types of stainless steel reducing slag with specific surface area of 1766 cm2/g (S1) and 7970 cm2/g (S2) in developing self-compacting concrete (SCC). Particularly, two S2-blended SCCs incorporating with S1 and fly ash as fillers (calling as S-mix and F-mix) were prepared for a comparative investigation. In both SCCs, ordinary Portland cement was replaced by S2 with various ratios (from 0 % to 50 %, increment 10 %). Testing results show that in fresh state, the F-mix exhibits higher workability and longer initial setting time than those of S-mix. In hardened state, 10 % compressive strength loss was realized as increasing S2 content up to 30 % in the both SCCs; the strength of F-mix is up to 1.9 times of S-mix at the same rate of S2 replacement. Water absorption of the F-mix was below 3 %, suggested as a “good” quality concrete; whilst the S-mix could be longs to an “average” one. Resistivity and sulfate resistance of F-mix are considerably higher than those of S-mix. Moreover, based on the obtained data, compressive strength and electrical resistivity are correlated well with a logarithmic form

Complete sputtering metallization for high-volume manufacturing

AbstractIn spite of the substantial progress made in the last decade, the GaAs IC industry is still far from reaching the high manufacturing yields established by the Si fabs. High volume applications that target the large consumer electronics market bring a new challenge to the ordinary GaAs manufacturing line and the lure to be more “Si-like” is the motivation for many new process developments. However, adopting Si methods often requires a hard re-thinking of the traditional paradigms established in the early years of GaAs IC processing. By implementing an all-sputtered metallization process in conjunction with CO2 snow metal lift-off, we believe we overcame one such paradigm. We demonstrate that evaporation is not the only suitable method for lift-off patterning and show that sputtering could represent an attractive alternative. In this paper we will discuss some of the benefits and difficulties that come from using sputtering as the metal deposition method of choice in a high volume GaAs manufacturing line

Changes in physiological and biochemical parameters during the growth and development of guava fruit (Psidium guajava) grown in Vietnam

This research examined the ripening time of guava fruit to provide a scientific basis for better harvesting and preservation of these fruits. Biochemical research methods were used to analyse changes in physiological and biochemical parameters according to the growth and development of guava fruit. The fruit took 14 weeks after anthesis to reach its maximum size in terms of length and diameter. The chlorophyll content in guava peel peaked after 10 weeks, decreasing until week 15. The content of carotenoids, which was low at fruit formation, rose rapidly until fruit ripening, while the vitamin C and reducing sugar contents increased continuously and peaked at week 14. A gradual increase was seen in the starch and total organic acid contents from the beginning of fruit formation, with peaks at 10 weeks, followed by a moderate downward trend. The pectin content showed the same trend, as it declined gradually after peaking at 12 weeks. The first 4 weeks showed an increase in the tannin content, which decreased afterward. The study results show that guava fruit should be harvested after physiological maturity and before ripening completely (14 weeks) to ensure that the nutritional value of the fruit is maintained during storage. Highlights• Xa Li guava at 14 week after anthesis to reach its maximum size in terms of length and diameter. • The chlorophyll content in guava peel peaked after 10 weeks, decreasing until week 15. The content of carotenoids, which was low at fruit formation, rose rapidly until fruit ripening.• The vitamin C and reducing sugar contents peaked at week 14. A gradual increase was seen in the starch and total organic acid contents and peaks at 10 weeks, followed by a moderate downward trend. • The pectin content showed the same trend, as it declined gradually after peaking at 12 weeks. The first 4 weeks showed an increase in the tannin content, which decreased afterward.This research examined the ripening time of guava fruit to provide a scientific basis for better harvesting and preservation of these fruits. Biochemical research methods were used to analyse changes in physiological and biochemical parameters according to the growth and development of guava fruit. The fruit took 14 weeks after anthesis to reach its maximum size in terms of length and diameter. The chlorophyll content in guava peel peaked after 10 weeks, decreasing until week 15. The content of carotenoids, which was low at fruit formation, rose rapidly until fruit ripening, while the vitamin C and reducing sugar contents increased continuously and peaked at week 14. A gradual increase was seen in the starch and total organic acid contents from the beginning of fruit formation, with peaks at 10 weeks, followed by a moderate downward trend. The pectin content showed the same trend, as it declined gradually after peaking at 12 weeks. The first 4 weeks showed an increase in the tannin content, which decreased afterward. The study results show that guava fruit should be harvested after physiological maturity and before ripening completely (14 weeks) to ensure that the nutritional value of the fruit is maintained during storage. Highlights• Xa Li guava at 14 week after anthesis to reach its maximum size in terms of length and diameter. • The chlorophyll content in guava peel peaked after 10 weeks, decreasing until week 15. The content of carotenoids, which was low at fruit formation, rose rapidly until fruit ripening.• The vitamin C and reducing sugar contents peaked at week 14. A gradual increase was seen in the starch and total organic acid contents and peaks at 10 weeks, followed by a moderate downward trend. • The pectin content showed the same trend, as it declined gradually after peaking at 12 weeks. The first 4 weeks showed an increase in the tannin content, which decreased afterward

All-dielectric Metamaterial for Electromagnetically-induced Transparency in Optical Region

Metamaterial (MM) is emerging as a promising approach to manipulate electromagnetic waves, spanning from radio frequency to the optical region. In this paper, we employ an effect called electromagnetically-induced transparency (EIT) in all-dielectric MM structures to create a narrow transparent window in opaque broadband of the optical region (580-670 nm). Using dielectric materials instead of metals can mitigate the large non-radiative ohmic loss on the metal surface. The unit-cell of MM consists of Silicon (Si) bars on Silicon dioxide (SiO$_{2}$) substrate, in which two bars are directed horizontally and one bar is directed vertically. By changing the relative position and dimension of the Si bars, the EIT effect could be achieved. The optical properties of the proposed MM are investigated numerically using the finite difference method with commercial software Computer Simulation Technology (CST). Then, characteristic parameters of MM exhibiting EIT effect (EIT-MM), including Q-factor, group delay, are calculated to evaluate the applicability of EIT-MM to sensing and light confinement