75 research outputs found
Production scheduling in a make-to-order job shop under job arrival uncertainty
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (leaves 51-52).We consider job release control to improve the due date performance in a make-to-order job shop with fluctuating job arrival and fixed due dates. The basic idea is to delay the release of non-urgent jobs and control the work in process (WIP) before the bottleneck so as to control the lead time of urgent jobs. We propose two job release control models: bounded constraint control model and linear control model. In the two models, we analyze the effects of workload limit on the reduction of variability, the total WIP in the system as well as the WIP in the shop floor. We then build a spreadsheet simulation of queueing model to show the improvement of due date performance by job release control in a job shop.by Huang Fengjie.M.Eng
Multi-Modal Automatic Prosody Annotation with Contrastive Pretraining of SSWP
In the realm of expressive Text-to-Speech (TTS), explicit prosodic boundaries
significantly advance the naturalness and controllability of synthesized
speech. While human prosody annotation contributes a lot to the performance, it
is a labor-intensive and time-consuming process, often resulting in
inconsistent outcomes. Despite the availability of extensive supervised data,
the current benchmark model still faces performance setbacks. To address this
issue, a two-stage automatic annotation pipeline is novelly proposed in this
paper. Specifically, in the first stage, we propose contrastive text-speech
pretraining of Speech-Silence and Word-Punctuation (SSWP) pairs. The
pretraining procedure hammers at enhancing the prosodic space extracted from
joint text-speech space. In the second stage, we build a multi-modal prosody
annotator, which consists of pretrained encoders, a straightforward yet
effective text-speech feature fusion scheme, and a sequence classifier.
Extensive experiments conclusively demonstrate that our proposed method excels
at automatically generating prosody annotation and achieves state-of-the-art
(SOTA) performance. Furthermore, our novel model has exhibited remarkable
resilience when tested with varying amounts of data.Comment: Submitted to ICASSP 202
TranssionADD: A multi-frame reinforcement based sequence tagging model for audio deepfake detection
Thanks to recent advancements in end-to-end speech modeling technology, it
has become increasingly feasible to imitate and clone a user`s voice. This
leads to a significant challenge in differentiating between authentic and
fabricated audio segments. To address the issue of user voice abuse and misuse,
the second Audio Deepfake Detection Challenge (ADD 2023) aims to detect and
analyze deepfake speech utterances. Specifically, Track 2, named the
Manipulation Region Location (RL), aims to pinpoint the location of manipulated
regions in audio, which can be present in both real and generated audio
segments. We propose our novel TranssionADD system as a solution to the
challenging problem of model robustness and audio segment outliers in the trace
competition. Our system provides three unique contributions: 1) we adapt
sequence tagging task for audio deepfake detection; 2) we improve model
generalization by various data augmentation techniques; 3) we incorporate
multi-frame detection (MFD) module to overcome limited representation provided
by a single frame and use isolated-frame penalty (IFP) loss to handle outliers
in segments. Our best submission achieved 2nd place in Track 2, demonstrating
the effectiveness and robustness of our proposed system
Utjecaj sastava podloge na povećanje biomase micelija i proizvodnje egzopolimera s pomoću gljive Hericium erinaceus CZ-2
In this work, the effects of medium composition and fermentation parameters on the simultaneous production of mycelial biomass and exopolymer by medicinal mushroom Hericium erinaceus CZ-2 were investigated in shake flask cultures using one-factor-at-a-time method and orthogonal array design. Results showed that the most suitable carbon, nitrogen, mineral sources, and cofactors for the mycelial biomass and exopolymer production were: corn flour combined with 1 % glucose, yeast extract, KH2PO4 and corn steep liquor. The intuitive analysis of orthogonal array design results indicated that the effects of nutritional requirement on the mycelial growth of Hericium erinaceus CZ-2 were in regular sequence of corn flour combined with 1 % glucose > yeast extract > corn steep liquor > KH2PO4, and those on exopolymer production were in the order of corn flour combined with glucose > KH2PO4 > yeast extract > corn steep liquor. The maximal yield of mycelial biomass (16.07 g/L) was obtained when the composition of the culture medium was (in g/L): corn flour 30, glucose 10, yeast extract 3, KH2PO4 1, CaCO3 0.5, and 15 mL/L of corn steep liquor; while the maximal exopolymer yield (1.314 g/L) was achieved when the composition of medium was (in g/L): corn flour 30, glucose 10, yeast extract 5, KH2PO4 3, CaCO3 0.5, and 15 mL/L of corn steep liquor. In the 15-litre scale-up fermentation, the maximum mycelial biomass yield of 20.50 g/L was achieved using the optimized medium.U ovom je radu ispitan utjecaj sastava podloge i uvjeta fermentacije na istodobnu proizvodnju biomase micelija i egzopolimera s pomoću ljekovite gljive Hericium erinaceus CZ-2. Pokusi su provedeni na kulturama uzgojenim na tresilici, primjenom jednofaktorske metode i ortogonalnog modela. Rezultati su pokazali da su najbolji izvori dušika, minerala i kofaktora za proizvodnju biomase micelija i egzopolimera kukuruzno brašno s 1 % glukoze, ekstrakt kvasca, KH2PO4 i kukuruzni ekstrakt. Analizom ortogonalnog modela utvrđeno je da na povećanje micelija redom utječu: kukuruzno brašno s 1 % glukoze, zatim ekstrakt kvasca, kukuruzni ekstrakt i KH2PO4, a na proizvodnju egzopolimera kukuruzno brašno s glukozom, zatim KH2PO4, ekstrakt kvasca te kukuruzni ekstrakt. Najveći je prinos biomase micelija (16,07 g/L) postignut s ovim sastavom podloge (u g/L): kukuruzno brašno 30, glukoza 10, ekstrakt kvasca 3, KH2PO4 1, CaCO3 0,5 i 15 mL/L kukuruznog ekstrakta, a najveći je prinos egzopolimera (1,314 g/L) dobiven korištenjem podloge (u g/L) od: kukuruznog brašna 30, glukoze 10, ekstrakta kvasca 5, KH2PO4 3, CaCO3 0,5 i 15 mL/L kukuruznog ekstrakta. Povećanjem obujma fermentacije na 15 L dobiven je najveći prinos biomase micelija od 20,50 g/L pri optimalnim uvjetima
Pu-erh Tea Regulates Fatty Acid Metabolism in Mice Under High-Fat Diet
Pu-erh tea has been extensively reported to possess lipid lowering effects but the underlying mechanisms remained unclear. Free fatty acids (FFAs) are generally correlated with the development of obesity, leading to increased risk for type 2 diabetes mellitus and cardiovascular diseases. To investigate whether Pu-erh tea treatment alters FA metabolism, we treated HFD induced obese mice with Pu-erh tea for 22 weeks and analyzed FFA profiles of experimental mice using a UPLC-QTOF-MS platform. Results showed remarkable changes in metabolic phenotypes and FFA compositions in mice treated with or without Pu-erh tea. HFD induced a marked obese phenotype in mice as revealed by significantly increased body weight, liver and adipose tissue weight, lipid levels in serum and liver, and these parameters were markedly reduced by Pu-erh tea treatment. Several FFA or FFA ratios, such as DGLA, palmitoleic acid, and OA/SA ratio, were significantly increased while the levels of SA/PA and AA/DGLA were significantly reduced in HFD-induced obese mice. Interestingly, these differential FFAs or FFA ratios were previous identified as key markers in human obese subjects, and their changes observed in the HFD group were reversed by Pu-erh tea treatment. Moreover, a panel of FFA markers including C20:3 n6/C18:3 n6 and C20:3 n6/C20:2 n6, C18:3 n6/C18:2 n6, C18:3 n3/C18:2 n6 and C24:1 n9/C22:1 n9, which were previously identified as biomarkers in predicting the remission of obesity and diabetes in human subjects who underwent metabolic surgery procedures, were reversed by Pu-erh tea intervention. Pu-erh tea significantly improved glucose homeostasis and insulin tolerance compared to the HFD group. Additionally, Pu-erh tea treatment significantly decreased FFA synthesis genes and increased the expression of genes involved in FFA uptake and β-oxidation including FATP2, FATP5, PPARα, CPT1α, and ACOX-1. These finding confirmed the beneficial effects of Pu-erh tea on regulating lipid and glucose metabolism, and further validated a panel of FFA markers with diagnostic and prognostic value for obesity and diabetes
Droplet-like Fermi surfaces in the anti-ferromagnetic phase of EuFeAs, an Fe-pnictide superconductor parent compound
Using angle resolved photoemission it is shown that the low lying electronic
states of the iron pnictide parent compound EuFeAs are strongly
modified in the magnetically ordered, low temperature, orthorhombic state
compared to the tetragonal, paramagnetic case above the spin density wave
transition temperature. Back-folded bands, reflected in the orthorhombic/
anti-ferromagnetic Brillouin zone boundary hybridize strongly with the
non-folded states, leading to the opening of energy gaps. As a direct
consequence, the large Fermi surfaces of the tetragonal phase fragment, the low
temperature Fermi surface being comprised of small droplets, built up of
electron and hole-like sections. These high resolution ARPES data are therefore
in keeping with quantum oscillation and optical data from other undoped
pnictide parent compounds.Comment: 4 figures, 6 page
Total tardiness problem with future job arrival information
We consider a single machine total tardiness problem with different release times, different due dates and available information of future job arrival in the next time period W. The goal is to generate an effective schedule for minimizing total tardiness by utilizing the future job information.​Master of Science (Computer Integrated Manufacturing
The Twisting Bifurcations of Double Homoclinic Loops with Resonant Eigenvalues
The twisting bifurcations of double homoclinic loops with resonant eigenvalues are investigated in four-dimensional systems. The coexistence or noncoexistence of large 1-homoclinic orbit and large 1-periodic orbit near double homoclinic loops is given. The existence or nonexistence of saddle-node bifurcation surfaces is obtained. Finally, the complete bifurcation diagrams and bifurcation curves are also given under different cases. Moreover, the methods adopted in this paper can be extended to a higher dimensional system
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