Dynamic Pricing and Inventory Control with Fixed Ordering Cost and Incomplete Demand Information

We consider the periodic review dynamic pricing and inventory control problem with fixed ordering cost. Demand is random and price dependent, and unsatisfied demand is backlogged. With complete demand information, the celebrated [Formula: see text] policy is proved to be optimal, where s and S are the reorder point and order-up-to level for ordering strategy, and [Formula: see text], a function of on-hand inventory level, characterizes the pricing strategy. In this paper, we consider incomplete demand information and develop online learning algorithms whose average profit approaches that of the optimal [Formula: see text] with a tight [Formula: see text] regret rate. A number of salient features differentiate our work from the existing online learning researches in the operations management (OM) literature. First, computing the optimal [Formula: see text] policy requires solving a dynamic programming (DP) over multiple periods involving unknown quantities, which is different from the majority of learning problems in OM that only require solving single-period optimization questions. It is hence challenging to establish stability results through DP recursions, which we accomplish by proving uniform convergence of the profit-to-go function. The necessity of analyzing action-dependent state transition over multiple periods resembles the reinforcement learning question, considerably more difficult than existing bandit learning algorithms. Second, the pricing function [Formula: see text] is of infinite dimension, and approaching it is much more challenging than approaching a finite number of parameters as seen in existing researches. The demand-price relationship is estimated based on upper confidence bound, but the confidence interval cannot be explicitly calculated due to the complexity of the DP recursion. Finally, because of the multiperiod nature of [Formula: see text] policies the actual distribution of the randomness in demand plays an important role in determining the optimal pricing strategy [Formula: see text], which is unknown to the learner a priori. In this paper, the demand randomness is approximated by an empirical distribution constructed using dependent samples, and a novel Wasserstein metric-based argument is employed to prove convergence of the empirical distribution. This paper was accepted by J. George Shanthikumar, big data analytics.

Karakteristik Granul Ekstrak Rebung Apus (Gigantochloa apus) Dengan Metode Granulasi Basah

Apus shoots (Gigantochloa apus) is a plant that can be used as an appetite enhancer, because it contains curcumin compounds in it. According to the American Academy of Pediatrics, dietary fiber has a very important function in the body, which can make children full and facilitate the digestive system. Children's diet with sufficient fiber, can prevent constipation (difficult bowel movements). The purpose of this study was to determine the characteristics of the granules of apus shoots (Gigantochloa apus) extract that met the physical requirements of good granules. The research method for making granules of apus shoots (Gigantochloa apus) extract was wet granulation. The data obtained from this study is that the 1st granule formula is the optimal formula among the three formulas tested because the flow is faster, namely 23.47 gr/second so that the angle of repose is getting smaller, namely 30.02⁰ and the compressibility of 7% obtained is small so that the granules are smaller got good.Key words : Bamboo shoots Extract, Granules, Wet Granulation. AbstrakTanaman rebung apus (Gigantochloa apus) merupakan tanaman yang dapat digunakan sebagai penambah nafsu makan, karena mengandung senyawa kurkumin didalamnya. Menurut American Academy Ofpediatrics, Serat pangan memiliki fungsi yang sangat penting dalam tubuh yaitu dapat membuat anak kenyang dan memperlancar sistem pencernaan. Pola makan anak dengan serat yang cukup, bisa mencegah sembelit (susah buang air besar). Tujuan dari penelitian ini adalah untuk mengetahui karakteristik granul ekstrak rebung apus (Gigantochloa apus) yang memenuhi persyaratan fisik granul yang baik. Metode penelitian pada pembuatan granul ekstrak rebung apus (Gigantochloa apus) adalah granulasi basah. Data yang diperoleh dari penelitian ini adalah formula granul ke 1 merupakan formula yang optimal diantara tiga formula yang diuji karena sifat aliran lebih cepat yaitu 23,47 gr/detik sehingga sudut diam semakin kecil yaitu 30,02⁰ dan kompresibilitas 7% yang didapatkan kecil sehingga granul yang didapat baik.Kata kunci : Ekstrak Rebung apus, Granul, Granulasi Basah.

Silica Microspheres for Economical Advanced Solar Applications

This article aims to improve the toughness of pre-packaged grouts (PPG) by incorporating crumb rubber. The mechanism for toughness of PPG with crumb rubber was analyzed based on the uniaxial compression model. Crumb rubber with surfaces treated by different methods (NaOH solutions or microwave treatment) was observed by scanning electron microscopy (SEM). The effects of mesh sizes, amounts, surface-treated methods of crumb rubber, and mixing procedures on the PPG’s mechanical strength and rheological properties were investigated. The results showed that, firstly, the addition of crumb rubber improves the PPG’s toughness, while its mechanical strength is reduced. Adding NaOH solutions or microwave-treated crumb rubber into PPG can weaken the negative effects of crumb rubber on the PPG’s mechanical strength; however, this function is limited. Secondly, the crumb rubber grouts’ rheological properties can be fully exploited by increasing the stirring rate and time so that the fluidity of crumb rubber grouts is improved, which fulfils the characteristics of no bleeding and micro-expansion. Finally, the optimal formula and mixing technique of crumb rubber grouts were proposed in this paper. The results of this paper can provide a significant reference for the application of scrap tires.

Preparation and Properties Study of Cementitious Grouts Containing Crumb Rubber

This article aims to improve the toughness of pre-packaged grouts (PPG) by incorporating crumb rubber. The mechanism for toughness of PPG with crumb rubber was analyzed based on the uniaxial compression model. Crumb rubber with surfaces treated by different methods (NaOH solutions or microwave treatment) was observed by scanning electron microscopy (SEM). The effects of mesh sizes, amounts, surface-treated methods of crumb rubber, and mixing procedures on the PPG’s mechanical strength and rheological properties were investigated. The results showed that, firstly, the addition of crumb rubber improves the PPG’s toughness, while its mechanical strength is reduced. Adding NaOH solutions or microwave-treated crumb rubber into PPG can weaken the negative effects of crumb rubber on the PPG’s mechanical strength; however, this function is limited. Secondly, the crumb rubber grouts’ rheological properties can be fully exploited by increasing the stirring rate and time so that the fluidity of crumb rubber grouts is improved, which fulfils the characteristics of no bleeding and micro-expansion. Finally, the optimal formula and mixing technique of crumb rubber grouts were proposed in this paper.The results of this paper can provide a significant reference for the application of scrap tires.

Inductive graph invariants and approximation algorithms

We introduce and study an inductively defined analogue [Formula: see text] of any increasing graph invariant [Formula: see text]. An invariant [Formula: see text] is increasing if [Formula: see text] whenever [Formula: see text] is an induced subgraph of [Formula: see text]. This inductive analogue simultaneously generalizes and unifies known notions like degeneracy, inductive independence number, etc., into a single generic notion. For any given increasing [Formula: see text], this gets us several new invariants and many of which are also increasing. It is also shown that [Formula: see text] is the minimum (over all orderings) of a value associated with each ordering. We also explore the possibility of computing [Formula: see text] (and a corresponding optimal vertex ordering) and identify some pairs [Formula: see text] for which [Formula: see text] can be computed efficiently for members of [Formula: see text]. In particular, it includes graphs of bounded [Formula: see text] values. Some specific examples (like the class of chordal graphs) have already been studied extensively. We further extend this new notion by (i) allowing vertex weighted graphs, (ii) allowing [Formula: see text] to take values from a totally ordered universe with a minimum and (iii) allowing the consideration of [Formula: see text]-neighborhoods for arbitrary but fixed [Formula: see text]. Such a generalization is employed in designing efficient approximations of some graph optimization problems. Precisely, we obtain efficient algorithms (by generalizing the known algorithm of Ye and Borodin [Y. Ye and A. Borodin, Elimination graphs, ACM Trans. Algorithms 8(2) (2012) 1–23] for special cases) for approximating optimal weighted induced [Formula: see text]-subgraphs and optimal [Formula: see text]-colorings (for hereditary [Formula: see text]’s) within multiplicative factors of (essentially) [Formula: see text] and [Formula: see text] respectively, where [Formula: see text] denotes the inductive analogue (as defined in this work) of optimal size of an unweighted induced [Formula: see text]-subgraph of the input and [Formula: see text] is the minimum size of a forbidden induced subgraph of [Formula: see text]. Our results generalize the previous result on efficiently approximating maximum independent sets and minimum colorings on graphs of bounded inductive independence number to optimal [Formula: see text]-subgraphs and [Formula: see text]-colorings for arbitrary hereditary classes [Formula: see text]. As a corollary, it is also shown that any maximal [Formula: see text]-subgraph approximates an optimal solution within a factor of [Formula: see text] for unweighted graphs, where [Formula: see text] is maximum size of any induced [Formula: see text]-subgraph in any local neighborhood [Formula: see text].

Optimization of Storage Medium for Hematological Reference Samples in External Quality Assessment

Hematological reference samples for external quality assessment (EQA) in hematology are essential for many laboratories in Vietnam, however, the prices are high along with short storing time. This study attempted to establish an optimal formula for the manufacture of hematological reference samples for hematological EQA programs. Human red blood cells (RBCs) were mixed with goose RBCs (pseudo-leucocytes) and goat RBCs (pseudo-platelets) as alternatives for white blood cells (WBCs) and platelets (PLTs), respectively, in different formulas of storage media. The optimal formula was obtained using response surface methodology–central composite design (RSM-CCD). Three main factors affecting the concentrations of RBCs were determined by Plackett–Burmann matrix. The optimal concentrations determined by RSM-CCD were 46% serum, 0.44 g/L neomycin sulfate, and 2.5% glycerol. The model predicted that the maximum number of human RBCs was 4.1 × 1012 cells/L, pseudo-leucocytes was 6.4 × 109 cells/L, and pseudo-platelets was 188 × 109 cells/L. The practical concentrations of RBCs, pseudo-leucocytes, and pseudo-platelets were 4.21 × 1012 cells/L, 6.4 × 109 cells/L, and 187 × 109 cells/L, respectively, which showed 98.93% similarity with theoretical data. This result could be a premise for further study to improve manufacturing of hematological reference samples for hematology EQA programs.

Optimal adaptive race strategy for a Formula-E car

Appropriately managing battery state-of-charge and temperature while ensuring minimized lap time represents a crucial issue in Formula-E competitions. An open research question might relate to simultaneously guarantee near-optimality in the race strategy solution, computational light-weighting, and effective adaptability with respect to varying and unpredictable race conditions. In this paper, a novel near-optimal real-time capable Formula-E race controller is introduced that takes inspiration from the adaptive equivalent consumption minimization strategy (A-ECMS) approach. A reduced-order Formula-E car plant model is detailed first. The optimal Formula-E race problem subsequently discussed involves controlling at each lap the depletable battery energy, the thermal management mode, and the race mode in order to minimize the overall race time. Moreover, avoiding excessively depleting the battery energy and overheating the battery are considered as constraints for the race optimization problem. Dynamic programing (DP) is implemented first to obtain the global optimal Formula-E race strategy solution in an off-line control approach. The proposed real-time capable A-ECMS based race controller finds then detailed illustration. The flexibility of the introduced A-ECMS Formula-E race controller is guaranteed by optimally calibrating the related equivalence factors to adapt to the current vehicle states (i.e. battery state-of-charge, battery temperature, and lap number). Simulation results for the Marrakesh e-prix considering different race scenarios in terms of battery initial temperature and Safety car entry demonstrate that the estimated race time achieved by the A-ECMS race controller is always near-optimal being 1.7% higher at most compared with the corresponding global optimal benchmark provided by DP.

Pulse-Cereal Blend Extrusion for Improving the Antioxidant Properties of a Gluten-Free Flour

Extrusion is an interesting technological tool that facilitates pulse formulation into flour mixtures, with tailored fibre content, total antioxidant capacity (TAC) and glycemic index (GI) among other components in final formulas. The gluten-free (GF) market has significantly grown during the last years. GF products have evolved from specialty health foods to products targeted to the general population and not only associated to celiac consumers. This study evaluates how temperature, cereal base (rice/corn) and pulse concentration affect extruded flour properties and which conditions are more efficient to develop a gluten-free flour with high TAC and low GI. Additionally, it evaluated the effect of this optimal formula after the baking process. The results showed an increase of total phenol (TP) and antioxidant activity with extrusion, with a temperature-dependent effect (130 °C ≥ 120 °C ≥ 110 °C), which may imply an enhanced bioaccessibility of phenolics compounds after extraction. Extrusion increased GI in comparison to native flour; however, a dough temperature of 130 °C resulted in a significantly (p ≤ 0.05) lower GI than that observed for 110–120 °C doughs, probably associated to the pastification that occurred at higher temperatures, which would decrease the degree of gelatinization of the starches and therefore a significant (p ≤ 0.05) GI reduction. Corn-lentil flour showed higher antioxidant properties and lower GI index in comparison with rice-lentil blends. The formulation of the optimal blend flour into a baked product (muffin) resulted in a significant loss of antioxidant properties, with the exception of the reducing power (FRAP), although the final antioxidant values of the baked product were in the range of the original native flour blend before any process.

Influence of Boric Acid Additive on Physical Properties of Utilizing Wastes for Producing Eco-Friendly Fired Clay Tiles

This paper aimed at studying the influence of additive material boric acid in eco-friendly fired clay tiles. It is used as additive material by mixing with rice husk ash (RHA), brown glass cullet (BGC), local clay (LC), and sediment soil (SS). Effects of boric acid on the physical properties of ceramic bodies were investigated. The texture of specimen by utilizing waste materials was also studied. Mixture formulations consisted of 60% BGC, 10% RHA, 0-30% LC, and 0-30% SS with varying boric acid addition of 0-2%. Specimens were formed by uniaxial pressing with 100 bars, fired at 850 and 900°C, heating rate 100°C/h, and soaked for 1 h. The results showed that adding boric acid up to 2% had increased the flexural strength and decreased the water absorption of these specimens when fired at 850°C. On the contrary, the effects of adding boric acid fired at 900°C had decreased flexural strength and increased water absorption that showed the phenomenon of expanding specimens. However, the optimal formula of these clay tiles both fired at 850 and 900°C have passed the Thai Industrial Standards (TIS 2508-2555); Type BIII. Scanning electron microscope should they that microstructure characterization was in the glassy crystalline phase was found in high flexural strength specimens. In summary, exploiting boric acid can improve the physical properties of specimens with a low firing temperature, and fired clay wall tiles can be developed in this study. They can be identified as an environmentally eco-friendly building product.

OPTIMASI CAMPURAN AVICEL PH 101 DAN LAKTOSA SEBAGAI BAHAN PENGISI PADA TABLET EKSTRAK BUNGA ROSELLA (Hibiscus sabdariffa L.) SECARA GRANULASI BASAH

Rosella flower (Hibiscuss sabdariffa L.) in traditional medicine can provide protection against various diseases, such as coronary heart disease, cancer, lowering cholesterol, and liver disorders. This study aims to obtain the optimum formula of tablet of rosella flower extract with a mixture of Avicel PH 101 and lactose as a filler using wet granulation method. Rosella flower extract was obtained by maceration of rosella flower powder using 70% ethanol. The optimization formula for tablets using the Simplex Lattice Design method with Design Expert software version 10. The parameters used in the optimization are weight variation, hardness, friability and disintegration time. Verification of the optimal formula using the SPSS 18 program with the One Sample T-test method with a confidence level of 95%. The results showed that the optimal formula of tablet of rosella flower extract was the Avicel PH 101 97.82%: 2.17% lactose. The optimal formula has weight variation 1.53% ± 0.0073; hardness 5.087 kg ± 0.5135; the friability is 0.3% ± 0.041. The resulting disintegration was 22.99 minutes ± 2.218. The results of the verification of the optimal formula show that there is no significant difference between the predictions of the Simplex Lattice Design method and the results of the tests performed so that it can be said that the method is valid.