Sequential Production Research Articles

Sequential versus Concurrent Product Development: Approval Uncertainty, Time-Sensitive Consumption Utility, and Asymmetric Competition

Sequential versus Concurrent Product Development: Approval Uncertainty, Time-Sensitive Consumption Utility, and Asymmetric Competition

Forms of phosphorus and its bioavailability in rice grown in an alluvial soil treated with rock phosphate enriched compost

Lower utilization efficiency of phosphorus (P) in soils is a major setback for the agricultural sector. The objective of this study was to investigate the effect of compost enriched with Rock phosphate on fractions of P in soil and how these forms affect the bioavailability of P in Rice. P fertilization was performed with the enriched compost and compared with rock phosphate and a conventional P fertilizer i.e. single superphosphate (SSP). We conducted a field experiment at Bihar Agricultural University, Sabour with Rice as the test crop in a randomized block design. Chemical P fractions were estimated through sequential fractionation and biomass production and P concentrations in plant parts were measured to estimate the plant P uptake. Yield, yield attributing parameters and P uptake in straw and grain were observed to be affected significantly by the addition of P enriched compost along with 50% recommended dose for P with the total recommended dose for N and K, when compared to absolute control. The alkaline nature of experimental soil seemingly improves the solubility of P from various fractions and the use efficiency of rice, which favors P uptake which was evidently the factors that contributed to these results. The percentage contributions of different fractions to the total P content in soil after paddy harvest were observed to be in the order: Labile-P < Fe/Al-P < Ca-P < residual P. Combined application of P enriched compost and inorganics sustained crop yield and enhanced P uptake in Rice when compared with sole application of chemical fertilizers.

Sequential Production of ᴅ-xylonate and Ethanol from Non-Detoxified Corncob at Low-pH by Pichia kudriavzevii via a Two-Stage Fermentation Strategy.

Improving the comprehensive utilization of sugars in lignocellulosic biomass is a major challenge for enhancing the economic viability of lignocellulose biorefinement. A robust yeast Pichia kudriavzevii N-X showed excellent performance in ethanol production under high temperature and low pH conditions and was engineered for ᴅ-xylonate production without xylitol generation. The recombinant strain P. kudriavzevii N-X/S1 was employed for sequential production of ᴅ-xylonate and ethanol from ᴅ-xylose, feeding on ᴅ-glucose without pH control in a two-stage strategy of aerobic and shifting micro-aerobic fermentation. Acid-pretreated corncob without detoxification and filtration was used for ᴅ-xylonate production, then simultaneous saccharification and ethanol fermentation was performed with cellulase added at pH 4.0 and at 40 °C. By this strategy, 33.5 g/L ᴅ-xylonate and 20.8 g/L ethanol were produced at yields of 1.10 g/g ᴅ-xylose and 84.3% of theoretical value, respectively. We propose a promising approach for the sequential production of ᴅ-xylonate and ethanol from non-detoxified corncob using a single microorganism.

Improving search and recommendation by asking clarifying questions

Recently, there has been renewed interest in interactive search and recommender systems through the development of systems that ask clarifying questions (CQs) to users to better understand their information needs. Although the significance and effectiveness of CQs have been recongnized, research on modelling CQs to improve search and recommender systems is limited, compared to traditional search and recommender systems. Also, understanding users' willingness or ability to answer these CQs, and the extent to which CQs impact users' behavior and their ability to identify relevant information remains relatively unexplored. The work in this thesis provides a series of models and online user studies for search and recommender systems that construct and use CQs. In the first part of the thesis, we focus on CQ-based search and recommendation algorithms. We first propose a novel CQ-based document search algorithm, Sequential Bayesian Search based method for Technology-Assisted Review (SBSTAR) and its extension, to efficiently retrieve the last few, but significant, relevant documents [Zou et al., 2018; Zou and Kanoulas, 2020]. The algorithm sequentially selects and directly asks CQs to users about the presence or absence of an entity in the missing relevant documents. Next, we propose a novel CQ-based product search algorithm, Question-based Sequential Bayesian Product Search (QSBPS), to effectively locate products that users are looking for [Zou and Kanoulas, 2019]. The model is based on a duet learning framework that learns product relevance and the reward of the potential CQ to be asked to the user. Furthermore, we propose a novel CQ-based recommendation algorithm, Question-based recommendation (Qrec), to assist users to find items interactively [Zou et al., 2020a]. The model is first trained offline by a novel matrix factorization algorithm, and then iteratively updates the user and item latent factors online based on the user's answers. We experimentally test the performance of the proposed models and demonstrate that they outperform state-of-the-art baselines. In the second part of the thesis, we focus on the evaluation of CQ-based search and recommendation. We first conduct an online user study by deploying a CQ-based system in the domain of online retail, to understand to what extent users can answer CQs. We explore the user willingness, ability, and user perception to provide answers to CQs [Zou et al., 2020b]. Next, we conduct a large user study on web search to understand the impact of CQ interactions on user search behavior and satisfaction, and how users interact with different levels of quality of CQs under different user perceptions and conditions. Awarded by : University of Amsterdam, Amsterdam, The Netherlands on 6 September 2021. Supervised by : Evangelos Kanoulas, Maarten de Rijke. Available at : https://hdl.handle.net/11245.1/3c46aa78-98af-4997-aef7-44db7ab2fa3d.

Transcriptional profiling of sequentially generated septal neuron fates.

The septum is a ventral forebrain structure known to regulate innate behaviors. During embryonic development, septal neurons are produced in multiple proliferative areas from neural progenitors following transcriptional programs that are still largely unknown. Here, we use a combination of single-cell RNA sequencing, histology, and genetic models to address how septal neuron diversity is established during neurogenesis. We find that the transcriptional profiles of septal progenitors change along neurogenesis, coinciding with the generation of distinct neuron types. We characterize the septal eminence, an anatomically distinct and transient proliferative zone composed of progenitors with distinctive molecular profiles, proliferative capacity, and fate potential compared to the rostral septal progenitor zone. We show that Nkx2.1-expressing septal eminence progenitors give rise to neurons belonging to at least three morphological classes, born in temporal cohorts that are distributed across different septal nuclei in a sequential fountain-like pattern. Our study provides insight into the molecular programs that control the sequential production of different neuronal types in the septum, a structure with important roles in regulating mood and motivation.

Sequential Warped Products and Their Applications

In this paper, we study the sequential warped product manifolds, which are the natural generalizations of singly warped products. Many spacetime models that characterize the universe and the solutions of Einstein's field equations are known to have this new structure. For this reason, first, we investigate the geometry of sequential warped product manifold under some conditions of concircular curvature tensor. We also study the conformal and gradient almost Ricci solitons on the sequential warped product. These conditions allow us to obtain some interesting expressions for the Riemann curvature and the Ricci tensors of its base and fiber from the geometrical and the physical point of view. Then, we give two important applications of this concept in the Lorentzian settings, which are sequential generalized Robertson-Walker spacetimes and sequential standard static spacetimes and obtain the form of the warping functions. Also, by considering generalized quasi Einsteinian conditions on these spacetimes, we find some specific formulas for the Ricci tensors of the bases and fibers. Finally, we terminate this work with some examples for this structure.

Catalyst Replacement Policy on Multienzymatic Systems: Theoretical Study in the One-Pot Sequential Batch Production of Lactofructose Syrup

One-pot systems are an interesting proposal to carry out multi-enzymatic reactions, though this strategy implies establishing an optimal balance between the activity and operability of the involved enzymes. This is crucial for enzymes with marked differences in their operational stability, such as one-pot production of lactofructose syrup from cheese whey permeate, which involves two enzymes—β-galactosidase (β-gal) and glucose isomerase (GI). The aim of this work was to study the behavior of one-pot sequential batch production of lactofructose syrup considering both enzymes immobilized individually, in order to evaluate and design a strategy of replacement of the catalysts according to their stabilities. To this end, the modelling and simulation of the process was carried out, considering simultaneously the kinetics of both reactions and the kinetics of inactivation of both enzymes. For the latter, it was also considered the modulating effect that sugars present in the medium may have on the stability of β-gal, which is the less stable enzyme. At the simulated reaction conditions of 40 °C, pH 7, and 0.46 (IUGI/IUβ-gal), the results showed that considering the stability of β-gal under non-reactive conditions, meaning in absence of the effect of modulation, it is necessary to carry out four replacements of β-gal for each cycle of use of GI. On the other hand, when considering the modulation caused by the sugars on the β-gal stability, the productivity increases up to 23% in the case of the highest modulation factor studied (η = 0.8). This work shows the feasibility of conducting a one-pot operation with immobilized enzymes of quite different operational stability, and that a proper strategy of biocatalyst replacement increases the productivity of the process.

Learning from Substitutable and Complementary Relations for Graph-based Sequential Product Recommendation

Sequential product recommendation, aiming at predicting the products that a target user will interact with soon, has become a hotspot topic. Most of the sequential recommendation models focus on learning from users’ interacted product sequences in a purely data-driven manner. However, they largely overlook the knowledgeable substitutable and complementary relations between products. To address this issue, we propose a novel Substitutable and Complementary Graph-based Sequential Product Recommendation model, namely, SCG-SPRe. The innovations of SCG-SPRe lie in its two main modules: (1) The module of interactive graph neural networks jointly encodes the high-order product correlations in the substitutable graph and the complementary graph into two types of relation-specific product representations. (2) The module of kernel-enhanced transformer networks adaptively fuses multiple temporal kernels to characterize the unique temporal patterns between a candidate product to be recommended and any interacted product in a target behavior sequence. Thanks to the seamless integration of the two modules, SCG-SPRe obtains candidate-dependent user representations for different candidate products to compute the corresponding ranking scores. We conduct extensive experiments on three public datasets, demonstrating SCG-SPRe is superior to competitive sequential recommendation baselines and validating the benefits of explicitly modeling the product-product relations.

Biohydrogen production via integrated sequential fermentation using magnetite nanoparticles treated crude enzyme to hydrolyze sugarcane bagasse

This study presents a potential approach to enhance integrated sequential biohydrogen production from waste biomass using magnetite nanoparticle (Fe3O4 NPs) which is synthesized through waste seeds of Syzygium cumini. Consequences of 0.5% Fe3O4 NPs have been investigated on the thermal and pH stability of fungal crude cellulase. It is noticed that Fe3O4 NPs treated enzyme and control exhibits 100% activity in the temperature range of 45–60 °C and 45–55 °C, respectively. Moreover, Fe3O4 NPs treated enzyme showed extended thermal stability in the temperature range of 50–60 °C up to 12 h. Beside this, Fe3O4 NPs treated enzyme possesses 100% stability in the pH range of 5.0–7.0 whereas control exhibited only at pH 6.0. Enzymatic hydrolysis via Fe3O4 NPs treated enzyme has been employed which produces ∼68.0 g/L reducing sugars from sugarcane bagasse. Subsequently, sugar hydrolyzate has been utilized as substrate in the sequential integrated fermentation that produces ∼3427.0 mL/L cumulative hydrogen after 408 h. This approach may have potential for the pilot scale production of biohydrogen from waste biomass at low-cost in an eco-friendly manner.

A Comprehensive Bioprocessing Approach to Foster Cheese Whey Valorization: On-Site β-Galactosidase Secretion for Lactose Hydrolysis and Sequential Bacterial Cellulose Production

Cheese whey (CW) constitutes a dairy industry by-product, with considerable polluting impact, related mostly with lactose. Numerous bioprocessing approaches have been suggested for lactose utilization, however, full exploitation is hindered by strain specificity for lactose consumption, entailing a confined range of end-products. Thus, we developed a CW valorization process generating high added-value products (crude enzymes, nutrient supplements, biopolymers). First, the ability of Aspergillus awamori to secrete β-galactosidase was studied under several conditions during solid-state fermentation (SSF). Maximum enzyme activity (148 U/g) was obtained at 70% initial moisture content after three days. Crude enzymatic extracts were further implemented to hydrolyze CW lactose, assessing the effect of hydrolysis time, temperature and initial enzymatic activity. Complete lactose hydrolysis was obtained after 36 h, using 15 U/mL initial enzymatic activity. Subsequently, submerged fermentations were performed with the produced hydrolysates as onset feedstocks to produce bacterial cellulose (5.6–7 g/L). Our findings indicate a novel approach to valorize CW via the production of crude enzymes and lactose hydrolysis, aiming to unfold the output potential of intermediate product formation and end-product applications. Likewise, this study generated a bio-based material to be further introduced in novel food formulations, elaborating and conforming with the basic pillars of circular economy.

Effects of Sequential Operation with Heat Treatment and Mechanical Milling on Work Hardening for Superalloy GH4169

Engineering components are usually manufactured with sequential production processes. Work hardening due to previous production processes affects the machinability of the workpiece in subsequent operations. In this research, the surface work hardening of a workpiece manufactured by two sequential processes with heat treatment/milling (HT + M) and milling/heat treatment (M + HT) of superalloy GH4169 was investigated. First, the surface microstructure characteristics, including plastic deformation and grain size of the machined workpiece surface processed by the two sequential processes, were quantitatively presented. Then, the microhardness on the machined workpiece surface and its cross-section was measured and analyzed. Finally, a surface microhardness calculation model considering twin boundary deformation was proposed. Here, we also present the microstructure evolution principle of the machined workpiece surface by the two sequential processes. It was found that the degree of work hardening of HT + M machining was 179%, whereas that of M + HT was only 101%. The research results can be applied to the optimized selection of process sequence for manufacturing superalloy GH4169.

Developing two dynamic Malmquist-Luenberger productivity indices: An illustrated application for assessing productivity performance of Indian banks

In the presence of undesirable output(s) in the production process, the Malmquist-Luenberger productivity index (MLPI) has emerged as a standard tool to measure total factor productivity change and its distinct components, namely efficiency change and technical change. Notwithstanding, the standard version of MLPI has certain genuine downsides, particularly the commonness of infeasibility while computing cross-period directional distance functions with negative data values and the black-box representation of the production technology. For overcoming these downsides, this paper advances two extensions of the standard MLPI. Specifically, we propose dynamic Malmquist-Luenberger and dynamic sequential Malmquist-Luenberger productivity indices to measure the productivity change in a system that can be represented by a dynamic network production structure. The proposed indices take a holistic view of production technology that connects several divisions internally by intermediate processes and use the carryovers flow over time to add a temporal dimension to it. To exhibit the capability of the proposed extensions of MLPI, we model a three-stage dynamic network structure for Indian banks and compute the indices of productivity change, efficiency change, and technical change for forty-two banks for the period from 2010 to 2017. The empirical findings elucidate that the observed productivity growth in the Indian banking industry is primarily driven by technical progress.

Retail shopping at airports: Making travellers buy again

Airport retail has undergone significant change in the last decade. Today, many airports provide a broad selection of product varieties and an augmented shopping experience. In this study we focus on sequential purchasing which remains an unexplored topic in airport retail. Grounded in shopping momentum, we use real-world purchase data from 279,000 passenger boarding cards to test a conceptual model that examines relationships between first purchase expenditure, walking distances, time available for sequential shopping, crowding, payment type, product involvement, promotions and product type on sequential purchasing in three terminals at Dubai International Airport. Findings offer a significant theoretical contribution to the travel retail and sequential purchasing literature and have important practical implications for airport retail practitioners.

Innovative System for Scheduling Production Using a Combination of Parametric Simulation Models

The article deals with the design of an innovative system for scheduling piece and small series discrete production using a combination of parametric simulation models and selected optimization methods. An innovative system for solving production scheduling problems is created based on data from a real production system at the workshop level. The methodology of the innovative system using simulation and optimization methods deals with the sequential scheduling problem due to its versatility, which includes several production systems and due to the fact that in practice, several modifications to production scheduling problems are encountered. Proposals of individual modules of the innovative system with the proposed communication channels have been presented, which connect the individual elements of the created library of objects for solving problems of sequential production scheduling. With the help of created communication channels, it is possible to apply individual parameters of a real production system directly to the assembled simulation model. In this system, an initial set of optimization methods is deployed, which can be applied to solve the sequential problem of production scheduling. The benefit of the solution is an innovative system that defines the content of the necessary data for working with the innovative system and the design of output reports that the proposed system provides for production planning for the production shopfloor level. The DPSS system works with several optimization methods (CR—Critical Ratio, S/RO—Slack/Remaining Operations, FDD—Flow Due Date, MWKR—Most Work Remaining, WSL—Waiting Slack, OPFSLK/PK—Operational Flow Slack per Processing Time) and the simulation experiments prove that the most suitable solution for the FT10 problem is the critical ratio method in which the replaceability of the equipment was not considered. The total length of finding all solutions by the DPSS system was 1.68 min. The main benefit of the DPSS system is the combination of two effectively used techniques not only in practice, but also in research; the mentioned techniques are production scheduling and discrete computer simulation. By combining techniques, it is possible to generate a dynamically and interactively changing simulated production program. Subsequently, it is possible to decide in the emerging conditions of certainty, uncertainty, but also risk. To determine the conditions, models of production systems are used, which represent physical production systems with their complex internal processes. Another benefit of combining techniques is the ability to evaluate a production system with a number of emerging problem modifications.

Sequential warped product submanifolds having holomorphic, totally real and pointwise slant factors

Sequential warped product submanifolds having holomorphic, totally real and pointwise slant factors

Combinations of quantum observables and instruments

This article points out that observables and instruments can be combined in many ways that have natural and physical interpretations. We shall mainly concentrate on the mathematical properties of these combinations. After an introduction in section , section reviews the basic definitions and observables are considered in section . We study parts of observables, post-processing, generalized convex combinations, sequential products and tensor products. These combinations are extended to instruments in section . We consider properties of observables measured by combinations of instruments. We introduce four special types of instruments, namely Kraus, Lüders, trivial and semitrivial instruments. We study when these types are closed under various combinations. In this work, we only consider finite-dimensional quantum systems. A few of the results presented here have appeared in the author’s previous articles Gudder (2020 arXiv:2005.08117 [quant-ph], arXiv:2005.13642 [quant-ph], arXiv:2009.07371 [quant-ph]).

Isolation and Biochemical Characterization of Six Anaerobic Fungal Strains from Zoo Animal Feces.

Anaerobic fungi are prime candidates for the conversion of agricultural waste products to biofuels. Despite the increasing interest in these organisms, their growth requirements and metabolism remain largely unknown. The isolation of five strains of anaerobic fungi and their identification as Neocallimastix cameroonii, Caecomyces spec., Orpinomyces joyonii, Pecoramyces ruminantium, and Khoyollomyces ramosus, is described. The phylogeny supports the reassignment of Neocallimastix californiae and Neocallimastix lanati to Neocallimastix cameroonii and points towards the redesignation of Cyllamyces as a species of Caecomyces. All isolated strains including strain A252, which was described previously as Aestipascuomyces dubliciliberans, were further grown on different carbon sources and the produced metabolites were analyzed; hydrogen, acetate, formate, lactate, and succinate were the main products. Orpinomyces joyonii was lacking succinate production and Khoyollomyces ramosus was not able to produce lactate under the studied conditions. The results further suggested a sequential production of metabolites with a preference for hydrogen, acetate, and formate. By comparing fungal growth on monosaccharides or on the straw, a higher hydrogen production was noticed on the latter. Possible reactions to elevated sugar concentrations by anaerobic fungi are discussed.

Learning from being imitated

A long-standing view in the strategy literature is that being imitated by competitors hinders the competitive advantage of the firm. This study, however, proposes a different view that being imitated by others can actually help a firm sustain its competitive advantage in the context of sequential product developments. Drawing on the theory of experiential learning and strategic experimentation, I argue that imitation by competitors offers learning opportunities for the innovator because the imitation product can serve as a vicarious experiment from which the innovator learns more about its own product. Results from the unique data of the video game industry support the prediction that, conditional on the quality of the initial version of the product, the more heavily imitated an original product is, the higher quality the sequel of the original product tends to have. Furthermore, the positive effect on the quality of the innovator’s next-generation product is strengthened when market visibility of the imitators is high and weakened when the innovator experiences structural changes in its organizational units.

Causal and compositional structure of unitary transformations

The causal structure of a unitary transformation is the set of relations of possible influence between any input subsystem and any output subsystem. We study whether such causal structure can be understood in terms of compositional structure of the unitary. Given a quantum circuit with no path from input systemAto output systemB, systemAcannot influence systemB. Conversely, given a unitaryUwith a no-influence relation from inputAto outputB, it follows from [B. Schumacher and M. D. Westmoreland, Quantum Information Processing 4 no. 1, (Feb, 2005)] that there exists a circuit decomposition ofUwith no path fromAtoB. However, as we argue, there are unitaries for which there does not exist a circuit decomposition that makes all causal constraints evidentsimultaneously. To address this, we introduce a new formalism of `extended circuit diagrams', which goes beyond what is expressible with quantum circuits, with the core new feature being the ability to represent direct sum structures in addition to sequential and tensor product composition. Acausally faithfulextended circuit decomposition, representing a unitaryU, is then one for which there is a path from an inputAto an outputBif and only if there actually is influence fromAtoBinU. We derive causally faithful extended circuit decompositions for a large class of unitaries, where in each case, the decomposition is implied by the unitary's respective causal structure. We hypothesize that every finite-dimensional unitary transformation has a causally faithful extended circuit decomposition.

Adoption of ox-drawn minimum tillage ripping by smallholder farmers in Zambia

ABSTRACT Applying a triple hurdle model to nationally representative farm household data from Zambia, this study examines determinants associated with three sequential crop production decisions: animal draught power adoption, minimum tillage ripping adoption, and the extent of hectares ripped. The correlated random effects estimator is also used to explore two dimensions of minimum tillage ripping adoption: changes in adoption within a household over time (within-household effect) and differences in adoption between households at a given time (between-household effect). Results reveal that age and gender of the household head, the head's level of education, household labour, hectares cultivated, ripper ownership, loan access, receiving conservation farming advice and distance to agricultural service providers are some of the key determinants associated with the three stages investigated using the triple hurdle model. The correlated random effects results demonstrate that while certain factors enhance or inhibit the expected value of hectares ripped within a given household, it is not always the case that these factors have a similar effect when the analysis is between households. This article highlights policy options to enhance ownership of rippers, support smallholder farmer access to loans, facilitate development of agro-dealer networks, and innovative approaches for disseminating conservation farming information to farmers.