In this report we summarize the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC) from the 16th IACHEC Workshop at Parador de La Granja, Spain. Sixty-one scientists directly involved in the calibration of operational and future high-energy missions gathered during 3.5 days to discuss the status of the cross-calibration between the current international complement of X-ray observatories, and the possibilities to improve it. This summary consists of reports from the Working Groups with topics ranging across: the identification and characterization of standard calibration sources, multi-observatory cross-calibration campaigns, appropriate and new statistical techniques, calibration of instruments and characterization of background, preservation of knowledge, and results for the benefit of the astronomical community.
Compilation of papers presented by the VERITAS Collaboration at the 39th International Cosmic Ray Conference (ICRC), held July 14 through July 24, 2025 in Geneva, Switzerland.
This paper investigates the phenomenon of presidential constitutional engineering (PCE) in Sub-Saharan Africa between 1990 and 2020. It introduces a novel conceptual framework and classification system that captures the most frequent and impactful strategies used by political elites to retain power through legal-constitutional means. These include manipulating term limits, adopting new constitutions to reset term counts, altering electoral systems, and imposing restrictive candidacy conditions. Unlike broader notions of electoral manipulation, the paper focuses specifically on legal-constitutional reforms that reshape the structure of presidential competition. Drawing on our dataset of documented PCE attempts, it offers comparative insights into institutional fragility and the concentration of executive power. The framework contributes to both academic debate and policy design by offering a clear typology that scholars and practitioners can adapt to assess democratic resilience and constitutional stability across presidential systems.
Metamorphic testing has become one mainstream technique to address the notorious oracle problem in software testing, thanks to its great successes in revealing real-life bugs in a wide variety of software systems. Metamorphic relations, the core component of metamorphic testing, have continuously attracted research interests from both academia and industry. In the last decade, a rapidly increasing number of studies have been conducted to systematically generate metamorphic relations from various sources and for different application domains. In this article, based on the systematic review on the state of the art for metamorphic relations' generation, we summarize and highlight visions for further advancing the theory and techniques for identifying and constructing metamorphic relations, and discuss potential research trends in related areas.
We introduce "synchronous algebras", an algebraic structure tailored to recognize automatic relations (aka. synchronous relations, or regular relations). They are the equivalent of monoids for regular languages, however they conceptually differ in two points: first, they are typed and second, they are equipped with a dependency relation expressing constraints between elements of different types. The interest of the proposed definition is that it allows to lift, in an effective way, pseudovarieties of regular languages to that of synchronous relations, and we show how algebraic characterizations of pseudovarieties of regular languages can be lifted to the pseudovarieties of synchronous relations that they induce. A typical example of such a pseudovariety is the class of "group relations", defined as the relations recognized by finite-state synchronous permutation automata. In order to prove this result, we adapt two pillars of algebraic language to synchronous algebras: (a) any relation admits a syntactic synchronous algebra recognizing it, and moreover, the relation is synchronous if, and only if, its syntactic algebra is finite and (b) classes of synchronous relations with desirable closure properties (i.e. pseudovarieties) correspond to pseudovarieties of synchronous algebras.
En un mundo cada vez más interconectado, la diplomacia tecnológica emerge como una herramienta crucial para impulsar el desarrollo económico y fortalecer las relaciones internacionales. Este artículo propone examinar la estrategia de diplomacia tecnológica de Corea del Sur, específicamente con relación a América Latina, explorando cómo esta nación asiática ha tejido una red global de colaboración e innovación, cultivando lazos bilaterales y multilaterales. La metodología seleccionada es cualitativa, con un enfoque descriptivo y, a través de ella, se examinan las políticas, los programas y las alianzas estratégicas implementadas por Corea del Sur, y se revelan los vínculos tecnológicos con países latinoamericanos y el impacto en la imagen surcoreana. El artículo se propone, además, identificar los desafíos y las oportunidades que enfrenta esta relación en constante evolución, tales como las barreras culturales y la necesidad de adaptación a las demandas regionales. Se sostiene que a medida que se profundiza la cooperación tecnológica se vislumbran perspectivas prometedoras para una colaboración más estrecha y se discute si el desenvolvimiento de estas instancias de cooperación reproduce esquemas de dependencia tecnológica o, por el contrario, es una herramienta para el desarrollo autónomo de los países latinoamericanos. Como conclusión, este estudio ofrece una visión panorámica de cómo la diplomacia tecnológica puede ser un motor clave para el desarrollo global, fomentando la innovación y el progreso, y destaca la importancia de fortalecer los lazos entre Corea del Sur y América Latina en búsqueda de un futuro más próspero y tecnológicamente avanzado.
Compilation of papers presented by the VERITAS Collaboration at the 38th International Cosmic Ray Conference (ICRC), held July 26 through August 3, 2023 in Nagoya, Japan.
This article examines the factors of influence of relations between the protector state and the regional hegemon in terms of the resilience of the unrecognized state. The article is devoted to a comparative analysis of the lessons learned from the Nagorno-Karabakh war and non-peace.
Since the end of the Second World War new states have repeatedly emerged, secessions have occurred, and with them new conflicts. While some non-recognised states enjoy higher stability, others have great struggles in order to survive. Most of the literature focuses on the non-recognised states themselves and domestic factor, thus neglecting the role of global players as the regional hegemonn. The main objective of this paper is to find out whether hegemons (through the protector states) have an influence on the stability of the non-recognised states. A second alternative explanation emphasises the importance of the internal legitimacy of non-recognised states. Using the cases of Nagorno-Karabakh and Armenia, the study attempts to answer these questions through a qualitative analysis. The analysis of Armenia’s foreign policy between 1991-1992 and 2020 and the resilience around Nagorno-Karabakh is the core of the empirical part.
The results suggest that indeed relations between the hegemon and the protector state have an effect on the stability of the non-recognised state. A connection between the internal legitimacy of the non-recognised state and stability, on the other hand, cannot be concluded from the work. Despite the analytical function, the paper gives a good overview on the stability of non-recognised states, security policy and some of the post-communist conflicts.
Political science (General), Political institutions and public administration (General)
<p>The article presents an assessment of the evolution of the institutional environment of multilateral military and political cooperation between Western powers (USA and UK) in the Asia-Pacific region. The basis of the study was determined by military alliances in the Asia-Pacific region from the second half of the twentieth century to the present. The need to assess the evolution of the multilateral alliance of Western powers in the Asia-Pacific region is due to the current dynamics of changes in the approach to the implementation of military cooperation, which determines the need to create a new military alliance of the AUKUS type; as well as an analysis of the influence of the new alliance on the emerging international security system in the context of a stagnating confrontation between the United States and its allies and the People's Republic of China (including the strategic partnership with the Russian Federation).</p>
<p>As a result of the study, it was revealed that the emergence of a military and political alliance of the AUKUS type is due to the evolutionary-strategic need for the leader of the alliance (USA) to consolidate its hegemony within the Asia-Pacific region after the loss of influence in the region and the establishment of the dominance of the People's Republic of China in the early twentieth century. The general geopolitical trends in the development of the system of military and political alliance were also identified in the context of a correlating increase in conflict potential in the regional security system of the Asia-Pacific region with the increasing need of China to develop a strategic partnership with Russia against the backdrop of the military and political and economic crisis between the United States (and its allies) and the PRC. The intensifying confrontation between Washington and Beijing motivates the further deepening of Russian-Chinese relations. Both in the field of trade, economic and military cooperation.</p>
Robin Cockett, Amolak Ratan Kalra, Shiroman Prakash
It is known that the category of affine Lagrangian relations, AffLagRel_F, over a field, F, of integers modulo a prime p (with p > 2) is isomorphic to the category of stabilizer quantum circuits for p-dits. Furthermore, it is known that electrical circuits (generalized for the field F) occur as a natural subcategory of AffLagRel_F. The purpose of this paper is to provide a characterization of the relations in this subcategory -- and in important subcategories thereof -- in terms of parity-check and generator matrices as used in error detection. In particular, we introduce the subcategory consisting of Kirchhoff relations to be (affinely) those Lagrangian relations that conserve total momentum or equivalently satisfy Kirchhoff's current law. Maps in this subcategory can be generated by electrical components (generalized for the field F): namely resistors, current dividers, and current and voltage sources. The "source" electrical components deliver the affine nature of the maps while current dividers add an interesting quasi-stochastic aspect. We characterize these Kirchhoff relations in terms of parity-check matrices and in addition, characterizes two important subcategories: the deterministic Kirchhoff relations and the lossless relations. The category of deterministic Kirchhoff relations as electrical circuits are generated by resistors circuits. Lossless relations, which are deterministic Kirchhoff, provide exactly the basic hyper-categorical structure of these settings.
As a special branch of global trade, the trade of agricultural products has an important impact on food security and the environment. In this paper, we studied international trade network of agricultural products from 2000 to 2016 as a whole and in part. We explored the overall characteristics of the network, analyzed the evolution of communities and identified core countries of the communities. The results show that the structure of the trade network became increasingly complex and the trade relations became closer over time. There were four major communities in the network, whose primary core countries were Germany, the United States, Brazil, and China. Since 2007, the community represented by China has disappeared, and the community pattern of the network has been in a three-pillar state and basically stable. We discuss the actual roles of certain trading countries, the formation of communities and the impact of economic events on agricultural products trade. This paper reveals the underlying patterns of the agricultural products trade and provides a way to track its evolution over time.
The two-dimensional internal rotation of KIC11145123 has been inferred via asteroseismology. Based on the Optimally Localized Averaging method and a simple three-zone modeling of the internal rotation, we have found evidence for a contrast between the internal rotation of the radiative region and that of the convective core; the radiative region rotates almost uniformly throughout the region, but the convective core may be rotating about 6 times faster than the radiative region above. We have also found a marginally significant evidence of latitudinal differential rotation in the outer envelope. These newly indicated features of the internal rotation of the star can help us further constrain the theory of angular momentum transport inside stars as well as understand the complex physical properties of the star, which was once thought to be a main-sequence A-type star but recently has been proposed to be a blue straggler, based on spectroscopy.
Compilation of papers presented by the VERITAS Collaboration at the 37th International Cosmic Ray Conference (ICRC), held July 12 through July 23, 2021 (online) in Berlin, Germany.
In the course of their activities, almost every business entity faces the problem of lack of own funds. This problem is especially acute in the agricultural sector. The constraining factor in the development of bank lending to agricultural enterprises, as always, is the high cost of credit resources and significant collateral requirements, which are often not enough to cover the credit obligations of borrowers. The purpose of the article is to analyze the current state of lending to agricultural enterprises in Ukraine and to substantiate the modern instruments of financial support of crediting of agrarian sphere. The authors conducted a comparative analysis of the efficiency of agricultural enterprises, depending on their size; the structure of financial resources is analyzed and the dependence on external sources of financing is proved; an assessment of the dynamics of the volume of credit investments in the agricultural sector. Study results show that the price factor has a negative impact on the formation of credit relations of agricultural enterprises with banking institutions. According to the authors, the promising instruments of financial support for lending to agricultural enterprises include programs of cooperation with international financial organizations, including the European Investment Bank and the German-Ukrainian Fund. It was established that in Ukraine agricultural enterprises are given ample opportunities to attract credit resources. In order to intensify the lending process, it is important to continue the process of improving the mechanism of forming the value of credit resources and to start work on solving the problematic issues of securing credit obligations by agricultural enterprises. On the other hand, agricultural enterprises must work to increase their own investment attractiveness – to form a positive image; to maintain the financial stability of enterprises at the appropriate level; to develop the organizational and financial culture of the enterprise; increase production efficiency; to improve methodological approaches to drawing up business plans taking into account the requirements of international financial organizations, etc.
The new international land and sea trade channel is an important part of China’s “The Belt and Road Initiative” going south, with Chongqing as the operating center, and 7 provinces and cities such as Guangxi, Guizhou, and Gansu as key nodes. Gravity Model of Trade is adopted to analyze the issue of trade creation effect and trade transfer effect in the flow of China-ASEAN trade in detail. According to the theoretical trade value calculated by the export gravity model, the actual trade value was divided by the theoretical value to calculate the trade potential coefficient, which has been applied to measure the trade potential of export of 8 provinces and cities to the ten ASEAN countries. It is concluded that trading partners are in different types ranging from “potential remodeling”, “potential expansion” to “great potential”, and heterogeneity tests are performed to prove the self-consistency of the effect measurement. Further, it is proposed that to further develop trade relations, we must develop positive factors to promote export trade, stimulate trade needs of partner countries, and actively develop trade market countermeasures.
The 6th problem of the 50th International Mathematical Olympiad (IMO), held in Germany, 2009, is called 'the grasshopper problem'. To this problem Kos developed theory from unique viewpoints by reference of Noga Alon's combinatorial Nullstellensatz. We have tried to solve this problem by an original method inspired by a polynomial function that Kos defined, then examined for n=3, 4 and 5. For almost cases the claim of this problem follows, but there remains imperfection due to 'singularity'.