Bulletin of NTU "KhPI". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice / Вісник Національного технічного університету "ХПІ". Серія: Проблеми удосконалювання електричних машин і апаратів. Теорія і практика
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Оптимізаційні задачі електромеханіки та їх розв'язування методом покоординатного пошуку
Full text linkThe design of electric machines and the development of their optimal structures involve certain challenges. These challenges include the need for designers to consider numerous factors influencing technical solutions, the complexity of manufacturing and testing physical models of electric machines, and the need to simulate operating conditions. One of the ways to address these challenges without significantly increasing workforce requirements is to utilize the capabilities of modern computers that allows for the substitution of physical prototypes of electric machines with their mathematical models, while test and measurement equipment can be replaced with analysis, optimization, and testing software programs. The continuous advancement of computer technology offers increasingly broader opportunities for its application across various industries. In design and engineering tasks, computational tools are utilized comprehensively as part of Computer-Aided Design (CAD) systems. The practical application of such systems demonstrates their high efficiency, achieved through improved technical and economic performance of designed objects, significant reductions in design timelines, and enhanced project quality. This paper presents a mathematical formulation of the optimization problem for electric machines, analyzes methods for solving such optimization problems, and develops an algorithm and program for determining the extremum of the objective function using the coordinate search method. These advancements enable the design of electric machines with optimal performance characteristics.Проектування електричних машин, створення їх оптимальних конструкцій пов'язане з деякими труднощами, які полягають у необхідності врахування проектувальником великої кількості факторів, що впливають на технічне рішення, складності виготовлення і випробування фізичної моделі електричної машини з імітацією умов, в яких вони будуть працювати. Один із шляхів подолання цих труднощів без істотного збільшення чисельності працюючих – використання можливостей сучасних комп’ютерів, що дозволяють замінити макет електричної машини його математичною моделлю, комплекс вимірювально-випробувального устаткування програмами аналізу, оптимізації та випробувань. Постійне зростання можливостей комп’ютерної техніки відкриває все нові й ширші перспективи їх використання у різноманітних сферах виробництва. При виконанні проектно-конструкторських робіт обчислювальна техніка використовується комплексно у складі систем автоматизованого проектування (САПР). Досвід експлуатації таких систем свідчить про їх високу ефективність, що досягається за рахунок поліпшення техніко-економічних показників спроектованих за їх допомогою об’єктів, значного скорочення термінів проектування, підвищення якості проектів. Наведене у роботі математичне формулювання задачі оптимізації електричної машини, проаналізовані методи розв’язування задачі оптимізації електричної машини та розроблений алгоритм і програма знаходження екстремуму цільової функції методом покоординатного пошуку дозволяють проектувати електричні машини з оптимальними показниками
Розрахунок струмів коротких замикань на приєднаннях знижувальної підстанції 110/35/10 кВ
Full text linkThe article is devoted to a comprehensive analysis and calculation method of short-circuit currents (SC) at the connections of a 110/35/10 kV step-down substation, which is a critically important element in ensuring the reliability and stability of distribution electrical networks. The paper substantiates the relevance of the study in view of the growth of loads, the introduction of modern switching equipment, the emergence of distributed energy sources and the need for accurate selection of devices sensitive to short-circuit parameters. It is shown that for step-down substations with a complex busbar configuration and several power transformers, the magnitude of short-circuit currents significantly depends on the network scheme, the type of transformer winding connection, the parameters of the power source on the 110 kV side, as well as the reactive resistances of lines and transformers. The methods for determining the effective value of the periodic component of the short-circuit current, the aperiodic component, the surge current (pulse peak value), and the duration of the aperiodic component, taking into account the time constant, are highlighted. The results of the study allow us to formulate recommendations on the optimal choice of switching equipment, increasing the sensitivity of relay protection, ensuring the thermal and electrodynamic stability of current-carrying parts, as well as increasing the overall reliability of distribution networksСтаття присвячена комплексному аналізу та методиці розрахунку струмів коротких замикань (КЗ) на приєднаннях знижувальної підстанції 110/35/10 кВ, що є критично важливим елементом забезпечення надійності та сталості роботи розподільних електричних мереж. У роботі обґрунтовано актуальність дослідження з огляду на зростання навантажень, впровадження сучасного комутаційного обладнання, появу розосереджених джерел енергії та необхідність точного вибору апаратів, чутливих до параметрів КЗ. Показано, що для знижувальних підстанцій зі складною конфігурацією шин і декількома силовими трансформаторами величина струмів КЗ істотно залежить від схеми мережі, типу з’єднання обмоток трансформатора, параметрів джерела живлення на стороні 110 кВ, а також реактивних опорів ліній та трансформаторів. Висвітлено методики визначення діючого значення періодичної складової струму КЗ, аперіодичної складової, ударного струму (імпульсного пікового значення), а також тривалості аперіодичної складової з урахуванням постійної часу. Результати дослідження дозволяють сформувати рекомендації щодо оптимального вибору комутаційного обладнання, підвищення чутливості релейного захисту, забезпечення термічної та електродинамічної стійкості струмопровідних частин, а також щодо підвищення загальної надійності розподільчих мереж
Semantic priming supports infants’ ability to learn names of unseen objects
No full textHuman language permits us to call to mind representations of objects, events, and ideas that we cannot witness directly, enabling us to learn about the world far beyond our immediate surroundings. When and how does this capacity emerge? To address this question, we evaluated infants at 12 and 15 months, asking whether they establish a representation of a novel noun’s meaning in the absence of any visible referents, and use this representation to identify a candidate referent when it later becomes available. During training, infants (67 12-month-olds; 67 15-month-olds) were primed with words and images of objects from a particular semantic neighborhood (e.g., fruits) and were also introduced to a novel noun (e.g., “a modi”), used to name a hidden object. During test, infants heard that noun again, this time with two unfamiliar objects present—one from the primed neighborhood (e.g., a dragon fruit) and the other from an unrelated semantic neighborhood (e.g., an ottoman). If infants can represent something about the meaning of the novel noun in the absence of a visible referent and then use such a representation when a candidate referent appears, then at test, they should prefer the object from the primed semantic neighborhood. At 15 months, infants succeeded. In contrast, 12-month-olds did not succeed on this task even after a full week of vocabulary training designed to boost the effect of priming. It is possible then that 12-month-olds’ representations of novel nouns’ meaning are not yet sufficiently rich (if any at all) to guide their choice of referent when one does appear. Together, these findings suggest that the capacity to establish a representation of a novel noun’s meaning in the absence of any visible referent and use this representation later to identify a candidate referent object emerges between 12 and 15 months
Are There Ideological Asymmetries in Intergroup Bias? A Minimal Groups Approach
No full textThe divide between political liberals and conservatives is rapidly growing. Several influential theories contend that this divide hinges on orientations towards social groups, such that conservatives (versus liberals) show a greater tendency to favor their “ingroups” and discriminate against “outgroups”. However, other theories contend that liberals and conservatives do not differ in their degree of intergroup bias. Both perspectives have received empirical support, and the debate has reached a standstill. We argue that this theoretical and empirical stalemate stems from inherent limitations of examining attitudes towards real-world social groups—a strategy used by both sides of the debate. Drawing on social identity theory, we conducted a series of four studies (Total N = 4389) using “minimal groups” (i.e., experimentally constructed groups) to determine whether and why ideological differences in intergroup bias may exist. We found robust evidence of ideological differences in intergroup bias, with conservatives favoring their own social groups over others. These ideological differences were relatively small but statistically robust across most contexts we examined. Importantly, however, when groups were based on shared moral and political values, liberals showed as much intergroup bias as conservatives. These results help resolve this long-standing debate and deepen our understanding of the psychological underpinnings of political ideology
Anti-Egalitarians are Lenient Towards Corporate Misconduct: Mixed Evidence for the Role of Threat and Mind Perception
No full textAlthough people’s ideological beliefs are key to understanding how they make moral judgments, existing research has been silent on how such ideological beliefs drive their psychological perceptions of corporations and their responses to corporate misconduct. Across multiple studies we consistently found that people high in SDO judge organizational transgressions less harshly. These results generalized across organizational size and industry, and they were not explained by political orientation. However, evidence for the mechanism for this relationship, including the role of mind perception and perceived threat, was mixed. We discuss possible reasons for such mixed evidence and the theoretical implications of the findings
A Hierarchical Unequal-Variance Signal Detection Model for Binary Responses
No full textGaussian signal detection models with equal variance are commonly used in simple yes-no detection and discrimination tasks whereas more flexible models with unequal variance require additional information. Here, a hierarchical Bayesian model with equal variance is extended to an unequal- variance model by exploiting variability of hit and false alarm rates in a random sample of participants. This hierarchical model is investigated analytically, in simulations and in applications to existing data sets. The results suggest that signal variance and other parameters can be accurately estimated if plausible assumptions are met. It is concluded that the model provides a promising alternative to the ubiquitous equal-variance model for binary data
“干中学”能学会所需的知识和技能吗？
No full text学生通过“捐着学(learning by giving)”，到底能不能最终学到成为下一代慈善家呢？通过对参加体验式慈善（Experiential Philanthropy）课程的美国和中国大学生的课前课后问卷分析，以及学生对开放问题的文本挖掘，我们发现体验式慈善课程显著提高了学生的公益意识，学业表现，社区参与意向以及未来慈善意向。所以我们认为答案是肯定的：学生抗议通过捐着学学到成为下一代慈善家的知识和技能
Regimes, Leaders, and Lockdowns: Who Responded More Quickly to the COVID-19 Pandemic?
No full textDo institutions or individuals shape policy in a crisis? We examine the timing of COVID-19 lockdowns in relation to regime type and leader characteristics. One view emphasizes institutional structure: were autocracies, with fewer constraints, quicker to lock down? Another highlights individual traits: did the speed of response depend on whether those in charge were doctors, scientists, women, or populists? Using a global dataset for 188 countries of political leaders and health ministers in office at the start of the pandemic, we find that democracies implemented lockdowns faster than autocracies. Individual traits of leaders mattered little, though countries with doctors heading health ministries were less likely to lock down—suggesting their presence may have helped hesitant leaders delay action. Our design addresses concerns about reciprocal causation and sample selection bias and proves robust to potential confounders. Political institutions, more than individual attributes, shaped the initial pandemic response
The causal impact of segregation on a disparity: A gap-closing approach
No full textSegregation---whether across schools, neighborhoods, or occupations---is regularly invoked as a cause of social and economic disparities. But segregation is a complicated causal treatment: what do we mean when we appeal to a world in which segregation does not exist? One could take societal contexts as the unit of analysis and compare across societies with differing levels of segregation. In practice, it is more common for studies of segregation to take persons or households as the unit of analysis within a single societal context, focusing on what would happen if particular individuals were counterfactually assigned to social positions in a more equitable way. Taking this latter framework, this paper shows how to study segregation as a cause. The first step is to theorize a counterfactual assignment rule: what would it mean to assign people to social positions equitably? The second step is to identify the causal effect of those social positions and simulate counterfactual outcomes. The third step is to interpret results as the impact of a unit-level (rather than society-level) intervention. A running example and empirical analysis illustrates the approach by studying the causal effect of occupational segregation on a racial health gap
The Architect and the Law
No full textArchitecture, at its core, is both an art and a science—the art of envisioning spaces and the science of realising them through thoughtful design. As a multidisciplinary field, architecture is influenced by a wide array of factors, from aesthetics and technology to economics and society. Among these, one of the most significant—and often underestimated—influences is the legal framework that governs architectural practice.
Architects, from the very outset of their professional journey, must navigate a complex landscape of responsibilities, regulations, and client relationships. Understanding the laws and regulations that apply to the profession is not merely advantageous—it is essential. Legal awareness empowers architects to practice with greater confidence, avoid potential pitfalls, and uphold the integrity of their work.
The law should not be perceived as a hindrance or a bureaucratic burden. Rather, it serves as a safeguard—an essential mechanism that upholds justice, protects rights, and defines responsibilities within society. In the event of a professional dispute, architects must be well-informed of their own legal obligations, as well as the rights and duties of other parties. As the well-known legal principle states, “Ignorance of the law is no excuse.” If ignorance were a valid defence, the entire legal system would be undermined. In other words, “Ignorance of the law is no excuse in any country. If it were, the laws would lose their effect, because it can always be pretended” .
This book explores the legal aspects that influence the architectural profession, offering architects a foundational understanding of relevant legal, contractual, and procedural matters. It is intended as an accessible introduction to the key legal concepts that impact professional practice—from contract law and liability to dispute resolution and regulatory compliance.
The construction industry is inherently complex, high-stakes, and prone to conflict. With substantial sums of money, tight timelines, and multiple stakeholders involved, misunderstandings are common and often lead to legal disputes. This book outlines the roles and relationships of the various parties in construction contracts—architects, clients, consultants, contractors, engineers, construction managers, and others—and explains the legal principles that govern these professional interactions. Readers will also find guidance on how to approach conflict resolution, including available legal procedures and dispute resolution mechanisms.
This first edition, published by Alborz Fardanesh Publications, is written in Persian and comprises eleven chapters. It presents a comprehensive and practical overview of the legal knowledge required throughout an architect’s career. Topics include legal considerations from graduation to professional licensing, setting up an architectural practice, forming and managing contracts, the tendering process, and managing disputes, among many others.
Ultimately, “The Architect and the Law” aims to bridge the gap between architecture and legal literacy. By equipping architects with the tools to understand and apply the law, it fosters a more responsible, professional, and legally informed architectural community