Relative Importance Sampling For Off-Policy Actor-Critic in Deep Reinforcement Learning

Off-policy learning is more unstable compared to on-policy learning in reinforcement learning (RL). One reason for the instability of off-policy learning is a discrepancy between the target ($\pi$) and behavior (b) policy distributions. The discrepancy between $\pi$ and b distributions can be alleviated by employing a smooth variant of the importance sampling (IS), such as the relative importance sampling (RIS). RIS has parameter $\beta\in[0, 1]$ which controls smoothness. To cope with instability, we present the first relative importance sampling-off-policy actor-critic (RIS-Off-PAC) model-free algorithms in RL. In our method, the network yields a target policy (the actor), a value function (the critic) assessing the current policy ($\pi$) using samples drawn from behavior policy. We use action value generated from the behavior policy in reward function to train our algorithm rather than from the target policy. We also use deep neural networks to train both actor and critic. We evaluated our algorithm on a number of Open AI Gym benchmark problems and demonstrate better or comparable performance to several state-of-the-art RL baselines

Book Review

Acute cholesterol depletion is generally associated with decreased or abolished T cell signalling but it can also cause T cell activation. This anomaly has been addressed in Jurkat T cells using progressive cholesterol depletion with methyl-beta-cyclodextrin (MBCD). At depletion levels higher than 50% there is substantial cell death, which explains reports of signalling inhibition. At 10–20% depletion levels, tyrosine phosphorylation is increased, ERK is activated and there is a small increase in cytoplasmic Ca2+. Peripheral actin polymerisation is also triggered by limited cholesterol depletion. Strikingly, the lipid raft marker GM1 aggregates upon cholesterol depletion and these aggregated domains concentrate the signalling proteins Lck and LAT, whereas the opposite is true for the non lipid raft marker the transferrin receptor. Using PP2, an inhibitor of Src family kinase activation, it is demonstrated that the lipid raft aggregation occurs independently of and thus upstream of the signalling response. Upon cholesterol depletion there is an increase in overall plasma membrane order, indicative of more ordered domains forming at the expense of disordered domains. That cholesterol depletion and not unspecific effects of MBCD was behind the reported results was confirmed by performing all experiments with MBCD–cholesterol, when no net cholesterol extraction took place. We conclude that non-lethal cholesterol depletion causes the aggregation of lipid rafts which then induces T cell signalling

Establishing a Performance Testing Approach for E-Learning Applications

Most of the E-Learning applications perform poorly in motivating employees to learn. To solve this problem, we need to examine what workplace e-learning requires and how workplace e-learning systems should be developed in line with those requirements. We investigated the problem by identifying the fundamental elements of the workplace learning environment including the learner, organization, learning content and social context, and their relationships. We found that workplace e-learning should align individual and organizational learning needs, connect learning and work performance, and support social interaction among individuals. To achieve this, a performance testing approach is proposed. Key performance indicators are utilized to clarify organizational goals, make sense of work context and requests on work performance, and accordingly help employees set up rational learning objectives and enhance their learning process. Using this approach, prototype system has been developed and a set of experiments have been conducted to demonstrate the effectiveness of the approach. This paper also presents the use of software verification, validation and testing technique, traditionally used in the software development, in the design and implementation of E-Learning products. We examine the ways one can apply testing techniques in E-Learning life cycle. This includes the strategy adoption for the selection of testing technique along with tool acquisition and measurement. The objective is to develop a collaborative approach involving software testing and educational methodology

Impacts of Adopting Sustainable Land Management Practices on the Livelihoods of Smallholder Farmers The Case of Benishangul Gumuz Region, Ethiopia

Land degradation has been identified as one of the most serious problems that threaten the sustainability of agriculture. In an effort to address these problems, the basic paradigm and approach to soil and water conservation has itself evolved over time. In recent years more holistic and land-scape wide approaches that go beyond resource conservation towards improved land husbandry and water management for beneficial conservation have been promoted using a national guideline. Hence, the major concern of this study was impact of adoption of SLMP. To meet this objective a total of 156 sample households, consisting 78 Sustainable land management adopter and 78 non adopter/ non- participants, were randomly selected from three kebeles in sample district. Descriptive statistics with appropriate statistical tests, and propensity score matching (PSM) were used to meet the stated objective. Descriptive statistical analyses such as mean, standard deviation and percentage were used to analyses basic household characteristics and the. Estimates of propensity score matching (PSM) indicate the existence of significant crop production increment on average 2.5 quintal production increment per hectare in each household head that were participated in adoption of sustainable land management practice value premium compared to non-adopter. The result indicated that Sustainable land management is crucial in improving the livelihoods of the farm households. However, to realize the intended outcomes, solving the fragmented nature of land holding, motivating development agent, rewarding model farmers require immediate attention. Keywords:  Sustainable land management, Propensity Score Matching, livelihood

Comparison of the TiVA and traditional data based on income groups in the gravity models application

This article continues the line of research by Fertő et al. (2022) and aims to find if there are any differences between Trade in Value-Added (TiVA) data and traditional data of international trade in the gravity model application when 66 OECD and non-OECD countries are grouped by income level. In addition, the paper also examines differences in gravity model factors between high-income vs. low- and middle-income countries in international trade. In the gravity model application, fixed effects and PPML methods are applied with a 3-year interval. According to the results, the differences between TiVA and traditional data are still minor for both income groups. Additionally, it is found that distance and language have a greater influence on the exports of low and middle-income countries, while shared borders, colonial history, and regional trade agreements are the factors that exert more impact on the exports of high-income countries

A study on the relationship between factors of physical environment comfort and employees job performance at Majlis Bandaraya Kuala Terengganu / Nurul Syakira Mahammad

The purpose of this study is to measure the relationship between physical environment comfort and employees' job performance at Majlis Bandaraya Kuala Terengganu (MBKT) located in Kuala Terengganu. This study also needs to identify which physical environment comfort factors that most influence the employees' job performance. Besides that, this study uses to identify the current problem faced by the employees from physical environment comfort toward their job performance. This study was conducted among the employees in three departments in the organization and the questionnaires have been distributed to all departments in the departments. The total population of this study was about 40 employees and 36 of them were took part as a respondents in answering the questionnaires. Through the findings, ergonomic office equipment factor is the most significant factor of physical environment comfort that affect employees' job performance while the least significant factor was noise. Several recommendations were suggested in order to make some improvement to the employees' job performance at Majlis Bandaraya Kuala Terengganu

Klimawandelinduzierte Verletzlichkeitsanalyse von Unternehmen und Branchen für 2030: Konzeptioneller Bezugsrahmen und empirische Befunde

Die deutschen Unternehmen sind bereits heute von Klimafolgen und Extremwetterereignissen betroffen. Unternehmen werden sich aber in Zukunft noch stärker auf die Auswirkungen des Klimawandels einstellen müssen. Sie erwarten, dass direkte und/oder indirekte Betroffenheit durch das Klimawandelphänomen bis 2030 zunehmen werden, und zwar in negativer Weise. Das geht aus einer bundesweiten Unternehmensbefragung durch das Institut der deutschen Wirtschaft Köln (IW) hervor, die Mahammad Mahammadzadeh, IW, in diesem Beitrag vorstellt. Ob und inwieweit die negativen Betroffenheit auch zu einer Verletzlichkeit der Betroffenen führt bzw. führen könnte, hängt insbesondere von deren Anpassungskapazität der finanziellen, personellen, technologischen, infrastrukturellen, institutionellen und wissensbasierten Ressourcen und Kompetenzen sowie den bereits implementierten oder geplanten Anpassungsmaßnahmen zur Reduzierung der negativen Betroffenheit durch die Klimafolgen ab. Den Ergebnissen der Umfrage zufolge besteht derzeit bei jedem zweiten deutschen Unternehmen ein Bedarf an Anpassungsmaßnahmen, die sowohl die betriebliche Infrastruktur und Versicherung gegen die Klimafolgen und Extremwetterereignisse als auch Frühwarn- und Informationssysteme sowie Klimaberatungen und Klimarisikomanagement einschließen

THE LINGUISTIC ANALYSIS OF THE GRAMMATICAL VARIABILITY

The actuality of the subject. Variability, and optionality is observed at all levels of the language as a universal feature of language means. One of the key features of contemporary linguistic research is the general typology of language means’ variability and focusing on issues such as functional specifications of various variants in the text. In contrast to other language levels, the problem of variability in syntax has been studied less. The complexity of the investigation of variability in the syntax field is conditioned by the dual nature of syntactic units, and their structure-content layout. The sentence as a syntactic unit changes the structural-content layout and functional aspect in the evolutionary process. Simple sentences the generally accepted communicative speech unit and generally accepted syntactic units have been widely studied in various aspects of modern linguistic studies and currently is being studied further. The simple sentence being a structural type of sentence had a long way to development in the modern English language as well as in other languages, and has come to the present situation having structural-semantic improvement through certain changes during the speech as a result of simplification in sentence models, the expression means in sentences. Until now, there is no comprehensive description of the variativity features of all syntactic models of simple sentences in the studies where the syntactic structure of the English language has been described. Still, structural-semantic features, variations emerged in the historical development process can be underlined as an important issue because of the controversial issues in the syntax with a simple sentence and this proves the relevance of the topic. All of these bring to the agenda the comparisons by analyzing the structure-semantic layout of the simple sentence in different periods of the English language, revealing the changes in the simple sentence models, sentence members, and their means of expression, word order, analyzing the causes of those changes as an actual lingvo-methodological issue. Many researchers (K.Abdullayev, S.Abdullayev, D.Yunusov, F.Veysalli, and others) have examined the problem of variativity in different types of sentences in Azerbaijani linguistics and have shown valuable works in this area. The term "variativity" is applied to describe the functionality of different language units in modern linguistics and during the discovery of its unobserved aspects. In recent decades, the concept of enhanced variativity in phonology has also contributed to extensive research in other areas of linguistics, including syntax

AN ANALYSIS OF INNOVATION AND CULTURAL DIVERSITY IN THE CHALLENGES AND PERSPECTIVES OF LOCAL COMPANIES' DEVELOPMENT: AN EXAMPLE OF AZERBAIJAN

The role of innovation is crucial for countries and businesses to gain competitive advantage. The key to success in the competitive process is to have a culture of innovation. The purpose of this study is to identify the link between innovation and cultural diversity in company management, which is one of the most important sources of competitive advantage, and to explore the role they play in company management. In this regards, a comprehensive review of innovation, cultural diversity and organizational culture has been conducted and links are established. The study concludes that innovation and cultural diversity have a major impact on innovation in companies and services.This study seeks to provide a comprehensive overview of the role of local innovation companies in the development challenges and perspectives, while providing insights into the concepts of innovation and cultural diversity. Research work can be considered as a good source for experts, researchers, and scientists working in this field