Number Of Available Choices Research Articles

Tiered Assortment: Optimization and Online Learning

Due to the sheer number of available choices, online retailers frequently use tiered assortment to present products. In this case, groups of products are arranged across multiple pages or stages, and a customer clicks on “next” or “load more” to access them sequentially. Despite the prevalence of such assortments in practice, this topic has not received much attention in the existing literature. In this work, we focus on a sequential choice model that captures customers’ behavior when product recommendations are presented in tiers. We analyze multiple variants of tiered assortment optimization (TAO) problems by imposing “no-duplication” and capacity constraints. For the offline setting involving known customers’ preferences, we characterize the properties of the optimal tiered assortment and propose algorithms that improve the computational efficiency over the existing benchmarks. To the best of our knowledge, we are the first to study the online setting of the TAO problem. A unique characteristic of our online setting, absent from the one-tier MNL bandit, is partial feedback. Products in the lower priority tiers are not shown when a customer has purchased a product or has chosen to exit at an earlier tier. Such partial feedback, along with product interdependence across tiers, increases the learning complexity. For both the noncontextual and contextual problems, we propose online algorithms and quantify their respective regrets. Moreover, we are able to construct tighter uncertainty sets for model parameters in the contextual case and thus improve the performance. We demonstrate the efficacy of our proposed algorithms through numerical experiments. This paper was accepted by J. George Shanthikumar, data science. Supplemental Material: The data files and e-companion are available at https://doi.org/10.1287/mnsc.2023.4940 .

Conflict-free collective stochastic decision making by orbital angular momentum of photons through quantum interference

In recent cross-disciplinary studies involving both optics and computing, single-photon-based decision-making has been demonstrated by utilizing the wave-particle duality of light to solve multi-armed bandit problems. Furthermore, entangled-photon-based decision-making has managed to solve a competitive multi-armed bandit problem in such a way that conflicts of decisions among players are avoided while ensuring equality. However, as these studies are based on the polarization of light, the number of available choices is limited to two, corresponding to two orthogonal polarization states. Here we propose a scalable principle to solve competitive decision-making situations by using the orbital angular momentum of photons based on its high dimensionality, which theoretically allows an unlimited number of arms. Moreover, by extending the Hong-Ou-Mandel effect to more than two states, we theoretically establish an experimental configuration able to generate multi-photon states with orbital angular momentum and conditions that provide conflict-free selections at every turn. We numerically examine total rewards regarding three-armed bandit problems, for which the proposed strategy accomplishes almost the theoretical maximum, which is greater than a conventional mixed strategy intending to realize Nash equilibrium. This is thanks to the quantum interference effect that achieves no-conflict selections, even in the exploring phase to find the best arms.

Analysis of the Boiler and Heat Exchanger Manufacturing Industry in the US Using Porter's Five Forces Framework

As global trade expands and technological progress is being made in developing countries, manufacturers of boilers and heat exchangers in the United States (US) are facing increasing import competition while industry profitability is competed away from industry rivals, market entrants, as well as by the growing number of available choices for buyers, and by suppliers with larger clientele and differentiated products and services. The forces that influence profitability in this industry is an essential part of strategic planning for any boiler and heat exchanger manufacturer that aims to control competition risk and optimize profitability. This research aims to break down and analyze the influences that industry manufacturers, market entrants, purchasers, component and raw material suppliers, foreign imports, technological advances, government policies, industry organizations, and future trends have on the profitability of industry players. While it was found that the level of competition in the industry is moderate, rapid advances in technology, increasingly stringent government policies on emission standards and boiler and heat exchanger efficiencies, as well as growing import competition may catalyze industry competition in the near future. The use of Porter’s five forces in this analysis suggests the need to consider the significance of technology and the challenges posed by imports through increasing globalization, as these factors could substantially change and disrupt the industry by reducing barriers to entry and by raising the threat of substitutes. As a result, the boiler and heat exchanger manufacturing landscape in the US could become much more competitive, which in turn, could diminish returns for industry operators. This could also change the structure of the industry with the inception of industry players that offer differentiated products and services. The question for industry groups and policy-makers is to what extent should these five forces be influenced, since the degree of support for or of counteraction to these forces will guide the future competitiveness and marketization of the boiler and heat exchanger manufacturing industry in the US.

Controversies in Thoracic Oncology

Over the past decade, there has been dramatic progress in the treatment of lung cancer, fueled by advancements in genomics and immunotherapy. A number of targetable oncogenes have been identified in NSCLC, starting with EGFR. There are currently seven oncogene products, ALK, BRAF, EGFR, RET, ROS1, MET, and NTRK, against which targeted kinase inhibitors are approved for use in the United States, and elsewhere. On the immunotherapy front, the programmed cell death protein 1/programmed death-ligand 1 inhibitors atezolizumab, durvalumab, nivolumab, and pembrolizumab are approved for NSCLC, and cemiplimab is under review by the U.S. Food and Drug Administration. As illustrated in Table 1, there are multiple approved agents for indications such as EGFR-mutant and ALK-rearranged NSCLC. With the other oncogene targets, there are two agents approved in most cases, and multiple other agents with potentially comparative efficacy are in clinical trials. Figure 1 is a treatment algorithm for NSCLC, illustrating the number of available choices for first-line immunotherapy in NSCLC in the United States, in addition to the numerous choices for molecularly targeted therapies described above.Table 1Targeted Therapeutic Agents for First-Line Treatment of NSCLCGeneTherapeutic AgentsALKAlectinib, brigatinib, ceritinib, crizotinib, lorlatinib, ensartinibBRAF V600EDabrafenib plus trametinib, vemurafenib, dabrafenibEGFROsimertinib, erlotinib, afatinib, gefitinib, dacomatinib, erlotinib plus ramucirumab, icotinib (PRC)MET exon 14Capmatinib, tepotinib, amivantamab, savlotinibNTRKLarotrectinib, entrectinibRETSelpercatinib, pralsetinibROS-1Crizotinib, entrectinib, ceritinib, lorlatinib, talotrectinib, brigatinib, cabozantinib, repotrectinibHER2Poziotinib, mobocertinib, DS-8201a, tarloxotinibNRGTarloxotinibNote: Bold, underlined font: approved by the U.S. FDA. Bold font: not approved but used off-label in the United States. Normal font: investigational.FDA, Food and Drug Administration; PRC, People’s Republic of China. Open table in a new tab Note: Bold, underlined font: approved by the U.S. FDA. Bold font: not approved but used off-label in the United States. Normal font: investigational. FDA, Food and Drug Administration; PRC, People’s Republic of China. A problematic situation in oncology, which is particularly amplified in thoracic oncology, is that of redundancy in clinical trials. A number of phase 3 trials have been conducted where the novel agent or combination has been compared with the old standard of care even though an approved new standard is available. An example is the first-line treatment of NSCLC, where pembrolizumab monotherapy was approved on the basis of KEYNOTE-024. The results of KEYNOTE-024 were presented at the European Society for Medical Oncology congress in late 2016, and yet a number of other programmed cell death protein 1/programmed death-ligand 1 inhibitors (atezolizumab, avelumab, durvalumab, nivolumab, and cemiplimab), activated or continued clinical trials for the same indication with comparisons against chemotherapy. Clearly from the purely scientific standpoint, the critical question to be answered would be if these agents were equivalent or superior to single-agent pembrolizumab in the same patient population. Because of secular trends in supportive care and differences in patient populations in different trials, it is generally agreed that comparisons of results across different phase 3 trials are not valid, and this practice is discouraged. Given this background, the lack of head-to-head comparisons of novel agents has produced a plethora of possible regimens, with little guidance on the optimal regimen, for health care providers. In other situations, accelerated approval has been based on surrogate end points such as progression-free survival, with no overall survival data available. Where survival data are presented, they tend to be immature, and not helpful in decision-making. There are, therefore, currently a number of situations where controversies exist regarding the ideal therapeutic choice for a given indication in lung cancer, particularly in NSCLC. Starting with this issue of the journal, we are introducing a new series—“Controversies in Thoracic Oncology.” These will be “Pro and Con” opinion pieces from experts dealing with topics that are open to debate. The first topic in this series is “Osimertinib as standard of care for the adjuvant therapy of stage IB-IIIA EGFR-mutant NSCLC.” We hope readers find this series of interest, and we welcome suggestions on topics for future debate.

Parallel Minority Game and it’s application in movement optimization during an epidemic

We introduce a version of the Minority Game where the total number of available choices is D>2, but the agents only have two available choices to switch. For all agents at an instant in any given choice, therefore, the other choice is distributed between the remaining D−1 options. This brings in the added complexity in reaching a state with the maximum resource utilization, in the sense that the game is essentially a set of MG that are coupled and played in parallel. We show that a stochastic strategy, used in the MG, works well here too. We discuss the limits in which the model reduces to other known models. Finally, we study an application of the model in the context of population movement between various states within a country during an ongoing epidemic. we show that the total infected population in the country could be as low as that achieved with a complete stoppage of inter-region movements for a prolonged period, provided that the agents instead follow the above mentioned stochastic strategy for their movement decisions between their two choices. The objective for an agent is to stay in the lower infected state between their two choices. We further show that it is the agents moving once between any two states, following the stochastic strategy, who are less likely to be infected than those not having (or not opting for) such a movement choice, when the risk of getting infected during the travel is not considered. This shows the incentive for the moving agents to follow the stochastic strategy.

STube: An Architecture for IoT Communication Sharing

In many IoT applications, there is a need to transmit the data collected by smart things to the cloud. The emerging SPS is one such system. Manufacturers/vendors have great interest in collecting data on their products for analysis and to enhance the overall smartness of the community. One obstacle is how to transmit the data from the things to the cloud. Rather than infiltrating other access networks for data transmission (e.g., a WiFi network in a building), a self-contained solution is preferred. It should be noted that many smart things are low-priced, making it impossible for them to afford the readily available channels (e.g., 3G/4G). To support this need, the industry is actively developing less expensive wireless communication channels. Unfortunately, the number of available choices in wireless communication channels is limited. However, the requirements of IoT applications for different costs and data rates are significantly more diversified. In this article, we address this problem by proposing Sharing Tube (sTube), an architecture for IoT communication channel sharing. Intrinsically, a greater number of smart things can share a smaller number of dedicated channels. We present the design and a case implementation of sTube. Our evaluation results demonstrate that sTube can achieve a cost saving of more than one order compared to a dedicated thing-to-cloud communication choice. This clears a core obstacle for many IoT applications in connecting to the cloud.

Correction of Hammertoe Deformity With Novel Intramedullary PIP Fusion Device Versus K-Wire Fixation

K-wire fixation has been the most common method of fixation for hammertoe deformity. However intramedullary devices are gaining ground in both number of available choices and in procedures performed. This study aimed to compare the outcomes of hammertoe correction performed with K-wire fixation versus a novel intramedullary fusion device (CannuLink). A retrospective review of hammertoe correction by a single surgeon was performed from June 2011 to December 2013. Sixty patients (95 toes) underwent K-wire fixation and 39 patients (54 toes) underwent fusion with the CannuLink implant. Average age was 61.7 years and 61.4 years, respectively. Average length of follow-up was 12.9 and 12.3 months, respectively. Patients were evaluated for medical comorbidities, smoking status, inflammatory arthritis, peripheral vascular disease, peripheral neuropathy, pre- and postoperative visual analog pain scale, bony union percentage, revision rate, complications (hardware and surgery-related), and persistent symptoms at last follow-up. There was no significant difference in demographics or comorbidities between the 2 groups ( P > .05). In the K-wire group, 16 patients (18 toes) remained symptomatic at last follow-up (27%). Nine toes (9.5%) had recurrent deformity, 3 toes (3%) developed a late infection because of the recurrent deformity, and 1 toe (1%) developed partial numbness. One patient suffered a calf deep vein thrombosis (DVT) and peroneal nerve neuritis, 1 patient developed foot drop, and 3 patients continued to complain of pain. Five toes required revision surgery (5.3%). In the intramedullary group, 3 (7.7%) patients remained symptomatic and all were associated with a complication. One patient developed chronic regional pain syndrome in the foot, a calf DVT, and a nonfatal pulmonary embolus. A second patient developed a painless recurrent deformity. A third patient had wound dehiscence. Nobody had hardware failure or required a second operation. The CannuLink intramedullary device for hammertoe correction resulted in fewer complications, only 1 recurrent deformity, and no reoperations compared with K-wire fixation. Level III, retrospective comparative study.

Correction of Hammer Toe Deformity with Novel Intramedullary PIP Fusion Device versus K-Wire fixation

Category: Lesser Toes Introduction/Purpose: K-wire fixation is the most common operative procedure for hammertoe deformity today. However, intramedullary implants are gaining ground in both number of available choices and in procedures performed. This study aimed to compare the outcomes of hammertoe correction performed with K-wire fixation versus a novel intramedullary fusion device. Methods: A retrospective review of hammertoe correction by a single surgeon was performed from June 2011 to December 2013. Sixty patients (95 toes) underwent K-wire fixation and 39 patients (54 toes) underwent fusion with the intramedullary implant. Average age was 61.7 years and 61.4 years, respectively. Average length of follow up was 12.9 and 12.3 months, respectively. Patients were evaluated for medical comorbidities, smoking status, inflammatory arthritis, peripheral vascular disease, peripheral neuropathy, pre and postoperative visual analogue pain scale, bony union percentage, revision rate, complications (hardware and surgery-related), and persistent symptoms at last follow up. Results: There was no significant difference in demographics or comorbidities between the two groups (p>0.05). In the K-wire group, sixteen patients (18 toes) remained symptomatic (27%). Nine toes (9.5%) had recurrent deformity, three toes (3%) developed a late infection due to the recurrent deformity and one toe (1%) developed partial numbness. One patient suffered a calf DVT and peroneal nerve neuritis, one patient developed a foot drop, and three patients continued to complain of pain. Five toes required revision surgery (5.3%). In the intramedullary group three (7.7%) patients remained symptomatic. One patient developed CRPS in the foot, calf DVT, and a non-fatal PE. A second patient developed a painless recurrent deformity. A third patient had wound dehiscence. Nobody suffered hardware failure or required a second operation. Conclusion: The intramedullary device for hammertoe correction resulted in less complications, recurrent deformity, and reoperations than K-wire fixation.

Cloud service selection using multicriteria decision analysis.

Cloud computing (CC) has recently been receiving tremendous attention from the IT industry and academic researchers. CC leverages its unique services to cloud customers in a pay-as-you-go, anytime, anywhere manner. Cloud services provide dynamically scalable services through the Internet on demand. Therefore, service provisioning plays a key role in CC. The cloud customer must be able to select appropriate services according to his or her needs. Several approaches have been proposed to solve the service selection problem, including multicriteria decision analysis (MCDA). MCDA enables the user to choose from among a number of available choices. In this paper, we analyze the application of MCDA to service selection in CC. We identify and synthesize several MCDA techniques and provide a comprehensive analysis of this technology for general readers. In addition, we present a taxonomy derived from a survey of the current literature. Finally, we highlight several state-of-the-art practical aspects of MCDA implementation in cloud computing service selection. The contributions of this study are four-fold: (a) focusing on the state-of-the-art MCDA techniques, (b) highlighting the comparative analysis and suitability of several MCDA methods, (c) presenting a taxonomy through extensive literature review, and (d) analyzing and summarizing the cloud computing service selections in different scenarios.

Public Goods Provision: An Evolutionary Game Theoretic Study Under Asymmetric Information

This paper presents an evolutionary, game theoretic approach to simulate and study the collective outcome of public goods (PG) provisioning in an agent-based model. Using asymmetric information as the basis for decision making, distinct groups are configured to interact in an iterated N player PG game, where coevolutionary learning is used as the adaptation tool to the dynamic environment. Impact of information type, number of players, group size, rate of interaction, number of available choices, nature of PG provision, and selection schemes are studied under a variety of settings. Simulation results reveal interesting dynamics of strategy and usage profiles, level of derived welfare, and the evolution of cooperation. Analysis of simulated attributes offers a more holistic understanding into the nature of collective action and insights of how the effects of social dilemma can be mitigated. This might provide a good guide to achieve efficient PG provision in the practical context.

Application-Driven Voltage-Island Partitioning for Low-Power System-on-Chip Design

Among the different methods of reducing power for core-based system-on-chip (SoC) designs, the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">voltage-island</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">technique</i> has gained in popularity. Assigning cores to the different supply voltages and floorplanning to create contiguous voltage islands are two important steps in the design process. We propose a new application-driven approach to voltage partitioning and island creation with the objective of reducing overall SoC power, area, and floorplanner runtime. Given an application power-state machine (PSM), we first identify the suitable range of supply voltages for each core. Then, we generate the discrete voltage assignment table using a heuristic technique. Next, we describe a methodology of reducing the large number of available choices from the voltage assignment table down to a useful set using the application PSM. We partition the cores into islands, using a cost function that gradually shifts from a power-based assignment to a connectivity-based one. Compared with previously reported techniques, a 9.4% reduction in power and 8.7% reduction in area are achieved using our approach, with an average runtime improvement of 2.4 times.

Combination Spinal Analgesic Chemotherapy: A Systematic Review

Combination Spinal Analgesic Chemotherapy: A Systematic Review

Combination spinal analgesic chemotherapy: a systematic review.

Combination spinal analgesic chemotherapy: a systematic review.

A model for the correction for guessing on multiple-choice tests

Multiple-choice tests are used widely because of obvious practical advantages, but inherent in them is the problem of dealing with the effects of guessing. The only widely used model for predicting effects of guessing is based on the primary assumption that, the probability of making a correct response on each test item is either 1.0 or the reciprocal of the number of available choices. The assumption that the subject either makes the correct response on each trial or guesses blindly is clearly too restrictive. Nunnally in [1] relates that because in most educational tests there is some opportunity for "narrowing" alternatives before guessing the standard correction for guessing tends to be an underestimate of the actual effects of guessing. The model proposed in this paper attempts to correct for this.