Hasil untuk "Competition"

M. Spence

B. F. S. Dobson

C. Holden, A. Subrahmanyam

S. Bucovetsky

Blaise Allaz, Jean-Luc Vila

M. Bengtsson, S. Kock

R. Marquez, Robert Hauswald

Sergio Eraso, Mehran Kardar

When competing species grow into new territory, the population is dominated by descendants of successful ancestors at the expansion front. Successful ancestry depends on both the reproductive advantage (fitness), as well as ability and opportunity to colonize new domains. We present a model that integrates both elements by coupling the classic description of one-dimensional competition (Fisher equation) to the minimal model of front shape (KPZ equation). Macroscopic manifestations of these equations are distinct growth morphologies controlled by expansion rates, competitive abilities, or spatial anisotropy. In some cases the ability to expand in space may overcome reproductive advantage in colonizing new territory. When new traits appear with accumulating mutations, we find that variations in fitness in range expansion may be described by the Tracy--Widom distribution.

Ermelinda Silva, Sara Najjari, Oren Shelef et al.

Intercropping is a pivotal strategy for achieving Sustainable Development Goal (SDG) number 2—<i>End hunger, achieve food security and improved nutrition and promote sustainable agriculture</i> (SDG 2)—by enhancing food security agroecosystem resilience and sustainability. By integrating diverse species within the same plot, this sustainable approach takes advantage of the beneficial interactions between them. The simultaneous cultivation of multiple crop species within the same field increases agricultural diversification and contributes to a more resilient production system, breaking the uniformity of modern intensive agriculture. The objective of this review is to evaluate intercropping practices throughout the Mediterranean, specifically in Southern Europe (Portugal, Spain, Italy, and Greece), North Africa (Morocco, Algeria, and Tunisia), and the Middle East (Turkey, Israel, and Jordan). This review intends to show advantages and disadvantages of intercropping and crops used and also highlight how intercropping systems affect crop production and quality, soil quality and microbiome, and proliferation of weeds, pests and diseases. The literature suggests that diversification in agriculture supports biodiversity and ecosystem services by the cultivation of diverse crop species together and, hence, may reduce independence in external outputs such as nutrient supply, pesticides and soil amendment. Despite the potential benefits of intercropping, the major caveats of this practice are the competition between different crops on resources, potential risks of plant protection, technical challenges of integrating the different requirements of each crop used in the system, and culture-related restrictions or regulations.

R. Rogers

Christian Birchler, Stefan Klikovits, Mattia Fazzini et al.

This is the first edition of the tool competition on testing self-driving cars (SDCs) at the International Conference on Software Testing, Verification and Validation (ICST). The aim is to provide a platform for software testers to submit their tools addressing the test selection problem for simulation-based testing of SDCs, which is considered an emerging and vital domain. The competition provides an advanced software platform and representative case studies to ease participants' entry into SDC regression testing, enabling them to develop their initial test generation tools for SDCS. In this first edition, the competition includes five tools from different authors. All tools were evaluated using (regression) metrics for test selection as well as compared with a baseline approache. This paper provides an overview of the competition, detailing its context, framework, participating tools, evaluation methodology, and key findings.

John M Bell, Jesse Elder, Rahil Ryder et al.

Novel SARS-CoV-2 variants demonstrating considerable intra-host evolution emerged throughout the pandemic. The persistent infections thought to give rise to these variants, however, have been difficult to identify at scale. This study sought to detect and characterize persistent infection cases in California using routine epidemiologic and genomic surveillance data. We identified 69 persistent infection cases with collection dates between January 2021 and July 2023 ranging from 21 to 400 days in duration, with an average of 44 days. Significant differences were identified in age distribution, sex, hospitalizations, and deaths between persistent infection cases and all sequenced California SARS-CoV-2 cases. Underlying health conditions were identified for the majority of cases with available medical records. In these cases, the Spike receptor binding domain was enriched for nonsynonymous mutations, and these mutations demonstrated convergent evolution indicative of immune evasion and were observed in previous persistent infections. We describe a 400-day B.1.429 infection that demonstrates substantial intra-host evolution, and a BA.5.11 persistent infection revealing apparent competition between two intra-host viral subpopulations. By establishing a framework for detecting persistent infections, this study lays the groundwork for other public health organizations to monitor and investigate highly divergent SARS-CoV-2 viruses.

Farhad Jahangiri, Abolfazl Danaei, Mahsa Akbari et al.

<p style="text-align: left;"><strong>Abstract</strong></p> <p style="text-align: left;">The purpose of this research is to design a model of the role of social media in the resilience of the digital supply chain in critical situations. In the qualitative phase of the current research, the data were collected from a purposive sample of 10 experts. Given the limited number of qualified individuals, the entire population of experts was included in the study. In the quantitative phase, the target population comprised 500 employees of MAPNA Company. Using Cohen's table for sample size determination, a sample of 189 participants was selected. This research employs a fundamental-applied approach and follows an exploratory mixed-methods design, integrating both qualitative and quantitative data. The data collection method was based on survey research and the data collection instuments included interviews and questionnaires, the content validity of which was confirmed by experts, and their reliability was calculated using Cronbach's alpha coefficient. In the qualitative part of the study, meta-composite method and foundation data were used, through which 118 open codes, 43 central codes and 13 selective codes have been extracted in five general categories: causal conditions, contextual conditions, intervening conditions, strategies and consequences. Causal conditions include 2 selected codes, 8 concepts and 21 open codes, contextual conditions include 3 selected codes, 10 concepts and 25 open codes, intervening conditions include 2 selected codes, 7 concepts and 21 open codes, strategies include 2 selected codes, 7 concepts and 19 open codes, and consequences include 4 selected codes, 11 concepts and 32 open codes, which are the components of the paradigm model regarding the role of social media in the resilience of the digital supply chain in critical conditions. Based on the output of the structural equations of the initial research model, its validity has been confirmed and the prioritization of the components of the mentioned model has been determined by a radar diagram of the research model. In this regard, technology risk tolerance was ranked first, liquidity cycle was ranked second, and collaboration and outsourcing were ranked third.</p> <p style="text-align: left;"><strong>Key Words:</strong> resilient supply chain, digital supply chain, social media</p> <p style="text-align: left;"><strong>1.Introduction</strong></p> <p style="text-align: left;">Social media has dramatically changed the way organizations interact and communicate with customers. Digital media and the provision of cheap access to social networks have brought many opportunities and achievements for businesses. Undoubtedly, with reducing the cost of accessing audiences and customers, increasing the speed, accuracy and quality of communication, providing the possibility of more accurate measurement of the effectiveness of activities, the possibility of better and more effective management of crises, and in general, increasing the power of businesses in the fields of work, providing opportunities for taking ownership of a media can be very useful and effective in the success of today's organizations and businesses, and without a doubt, social networks and similar channels have provided them with a variety of tools, applications, and developers in order to advance the supply of various tools. Considering the significant impact that social media has on life and business processes in the third millennium and the rapid and impressive developments of information and communication technology in recent decades, significant and in some cases fundamental changes have been made in various relationships of today's societies.</p> <p style="text-align: left;"><strong>2.Literature Review</strong></p> <p style="text-align: left;">In today's world, changes in the economy and industry are happening at a faster rate than in the past. Due to globalization, countries are ingreasingly experiencing heightened levels of competition. Given the importance of supply chains and their effective management in creating competitive advantages, it is often said that competition between organizations has been replaced by the competition between supply chains. As a result, organizations are trying to improve their supply chain management to gain sustainable competitive advantages (Lee et al., 2018). Achieving this requires a fundamental transformation within the organization. Given the importance of conducting this research, coupled with the instability of conditions and significant changes in work processes, it is necessary for organizations to adapt the scope of their supply chain so that they can develop optimal strategies to stay at the top of the competition in volatile conditions.</p> <p style="text-align: left;">Therefore, it is necessary for them to maintain their resilience in the mentioned conditions and be equipped with working methods suitable for the age of technology and new technologies (Singh et al., 2017). In other words, considering the significant impact that social media has on the processes of life and business in the third millennium and the rapid and impressive developments of information and communication technology in recent decades, there have been significant and in some cases fundamental changes in various relationships of today's societies (Labafi, 2018); Organizations and their communications have changed and the demands and expectations of customers have undergone many changes. Knowing the fact that the use of digital technologies in processes creates competitive advantages for businesses and organizations (Samizadeh, 2020), we can conclude that the implementation and use of the digital supply chain is undoubtedly a significant option for organizations and businesses. This work aimed to minimize financial and time costs while enhancing productivity in the production process until the final delivery of goods and services to customers (Azer &amp; Khorrami, 2021). By comparing the key features of the digital supply chain with the traditional supply chain, it can be seen that the results of the presence of digital technologies in the supply chain processes for organizations and businesses will be brilliant and efficient beyond imagination (Mehrabi, 2016). The smallest disruption in the process of a supply chain can be likened to a fault. A fault whose gap and depth can increase moment by moment (Manogran et al., 2018).</p> <p style="text-align: left;"><strong>3.Methodology</strong></p> <p style="text-align: left;">In the present study, the researcher sought to provide a model for the role of social media in the resilience of the digital supply chain in critical conditions. In this research, the metacomposite method has been used to present the model. In the qualitative part of the study 10 experts participated through the whole number selection, and the quantitative part included 500 employees of MAPNA company, based on Cohen's sample size table. The investigation began with an extensive review of the related existing literature (referring to documents and five non-Iranian databases of ScienceDirect, Web of Science, Google Scholar, Scopus, Emerald, and three Iranian databases CIVILICA, Magiran and SID). The total number of articles found considering the input criteria was 163 studies (Persian and English). After reviewing all the studies and evaluiating them based on content criteria and accessibility, the final results were extracted from 19 studies (14 English studies and 5 Persian studies) which were reviewed and analyzed. Then, in order to confirm the extracted factors, an interview was arranged with the relevant experts (including experts and specialists of the digital supply chain and social media and top managers of MAPNA Company) and the importance coefficient of each factor was determined.</p> <p style="text-align: left;"><strong>4.Result</strong></p> <p style="text-align: left;">According to the results, 118open codes, 43 central codes and 13 selective codes were extracted. Thirteen selective codes of the study were placed in five general categories including causal conditions, contextual conditions, intervening conditions, strategies and consequences. Causal conditions include 2 selected codes, 8 concepts and 21 open codes, contextual conditions include 3 selected codes, 10 concepts and 25 open codes, intervening conditions include 2 selected codes, 7 concepts and 21 open codes, strategies include 2 selected codes, 7 concepts and 19 open codes, and the consequences include 4 selected codes, 11 concepts and 32 open codes, which are the components of the paradigm model regarding the role of social media in the resilience of the digital supply chain in critical conditions. Based on the output of the structural equations of the initial research model, its validity has been confirmed and the prioritization of the components of the mentioned model has been determined by a radar diagram of the research model. In this regard, technology risk tolerance was ranked first, liquidity cycle was ranked second, and collaboration and outsourcing were ranked third.</p> <p style="text-align: left;"><strong>5.Conclusion</strong></p> <p style="text-align: left;">According to the obtained results and the importance of the topic under study, the role of social media and the implementation of digital transformation in organizations as an undeniable competitive advantage has been noticed by senior managers of organizations and businesses. Digitalization of the supply chain will bring revolutionary changes. New technologies such as big data, cloud computing, and the Internet of Things can help solve these problems. In fact, digitization can enhance supply chain visibility and the use of advanced digital technologies enables modularization, simplicity and standardization of products and processes. Companies must recognize the benefits of innovative business models that add value to their product portfolio and create new demand channels for more digital customers. In fact, investing and deploying new technologies by increasing access to information, reducing costs, improving product quality, and increasing responsiveness and collaboration capabilities provide a long-term competitive advantage for business supply chains even in critical situations.</p> <p style="text-align: left;"><strong>Conflict of interest: none</strong></p>

Daichi Shimizu, Takeshi Okada

Complex interactions are central to the performing arts. While recent studies have explored these dynamics through synchronization and coordination theories, they have mainly focused on collaborative contexts. In contrast, genres like jazz sessions and breaking battles involve active competition, where performers seek to outshine one another. Although prior research has identified patterns like anti-phase synchronization in such settings, coordination across expressive channels and differences from sports interactions remain underexplored. To address this gap, the present study had two objectives: first, to investigate coordination through back-and-forth movements during breaking battles, and second, to compare these patterns with those observed in interpersonal sports. We conducted an experimental study simulating a battle scene with expert break dancers, examining how they coordinated their movements and managed relative distances. The results revealed two key findings: (1) dancers maintained close distances (~1.0 m) while coordinating through anti-phase synchronization (−180° to −160° and 160° to 180° relative phases), with coordination patterns shifting dynamically—from leader-follower relationships to anti-phase and then in-phase synchronization—depending on context and time; and (2) such time- and context-dependent coordination dynamics were unique to the performing arts and not observed in interpersonal sports. This study highlights the distinctive nature of context-sensitive, multi-channel interpersonal coordination in competitive performing arts.

A. Peters

Marvin Washington, E. Zajac

P. Chesson, J. J. Kuang

M. Gage, Christopher P. Macfarlane, S. Yeates et al.

Tomer Ezra, Tamar Garbuz

We study the classic single-choice prophet secretary problem through a resource augmentation lens. Our goal is to bound the $(1-ε)$-competition complexity for different classes of online algorithms. This metric asks for the smallest $k$ such that the expected value of the online algorithm on $k$ copies of the original instance, is at least a $(1 - ε)$-approximation to the expected offline optimum on the original instance (without added copies). We consider four natural classes of online algorithms: single-threshold, time-based threshold, activation-based, and general algorithms. We show that for single-threshold algorithms the $(1-ε)$-competition complexity is $Θ(\ln(\frac{1}ε))$ (as in the i.i.d. case). Additionally, we demonstrate that time-based threshold and activation-based algorithms (which cover all previous approaches for obtaining competitive-ratios for the classic prophet secretary problem) yield a sub-optimal $(1-ε)$-competition complexity of $Θ\left(\frac{\ln(\frac{1}ε)}{\ln\ln(\frac{1}ε)}\right)$, which is strictly better than the class of single-threshold algorithms. Finally, we find that the $(1-ε)$-competition complexity of general adaptive algorithms is $Θ(\sqrt{\ln(\frac{1}ε)})$, which is in sharp contrast to $Θ(\ln\ln(\frac{1}ε))$ in the i.i.d. case.

Robert Boyce, Martin Herdegen, Leandro Sánchez-Betancourt

We study liquidity provision in the presence of exogenous competition. We consider a `reference market maker' who monitors her inventory and the aggregated inventory of the competing market makers. We assume that the competing market makers use a `rule of thumb' to determine their posted depths, depending linearly on their inventory. By contrast, the reference market maker optimises over her posted depths, and we assume that her fill probability depends on the difference between her posted depths and the competition's depths in an exponential way. For a linear-quadratic goal functional, we show that this model admits an approximate closed-form solution. We illustrate the features of our model and compare against alternative ways of solving the problem either via an Euler scheme or state-of-the-art reinforcement learning techniques.