bluuebunny/crossref_metadata_2025 huggingface dataset:
СИНТЕЗ ТА СПЕКТРАЛЬНІ ХАРАКТЕРИСТИКИ ПОХІДНИХ 2-ГІДРОКСИ-3-((2-МЕТИЛХІНОЛІН-4-ІЛ)ТІО) ПРОПА-НОВОЇ КИСЛОТИ
Authors: Дашенко Ірина , Генчева Вікторія
Published: January 2020

Синтезовано функціонально заміщені похідні хіноліну, а саме: 2-гідрокси-3-((2-метилхінолін-4-іл)тіо)пропанову кислоту та її похідні. Структуру досліджених сполук підтверджено за допомогою ЯМР-спектроскопії, хромато-мас-спектрометрії, ІЧ-спектроскопії. Дані спектрального аналізу дозволяють запропонувати для невідомої сполуки її структуру, а також дають можливість зробити висновки про відносну стереохімію.
СОМАТИЧНА ХВОРОБА ЯК СТРЕСОВИЙ ЧИННИК ПОРУШЕННЯ СЕКСУАЛЬНОГО ЗДОРОВ’Я ЛЮДИНИ
Authors: Прошукало Ігор
Published: January 2020

У статті розглядається проблема сексуального здоров’я людини під час перебування в ситуації соматичного захворювання. Хвороба може виступати тим стресовим чинником, яка впливає на сексуальну активність. Виходячи з розуміння стресу як неспецифічних змін, які виникають в організмі внаслідок інтенсивних або тривалих сторонніх впливів і призводять до надмірного напруження вроджених неспецифічних механізмів організму, хвороба розглядається як одна зі стресових чинників, яка викликає відчуття внутрішнього неспокою, що безпосередньо пов’язане з суб'єктивно пережитими емоціями – напругою, нервозністю, страхом, тривогою. Прояви цього стану можуть мати різну інтенсивність і обумовлюються не лише ступенем емоційної реакції на стресову ситуацію, а й здатністю до сприйняття і реагування на зовнішні подразники, а будь-яке соматичне захворювання обов’язково змінює психічний стан пацієнта внаслідок появи нових, відсутніх до хвороби форм реагування на саме захворювання. Сексуальне здоров’я залежить від певного комплексу складників, які забезпечують людину в прояві її сексуальності як уродженої потреби людського організму, – соматичні, емоційні, інтелектуальні та соціальні складники статевого існування особистості. Більшість пацієнтів, перебуваючи в стані хвороби або її хронічному перебігу, мають певні труднощі в задоволенні своїх сексуальних потреб. Це пов’язано не тільки з можливими фізичними обмеженнями чи сексуальними реакціями, а й власне сприйняттям себе та свого тіла у стані хвороби. У відносинах багатьох пар у цей період виникають проблеми після того, як один із партнерів опиняється в ситуації соматичного захворювання. Тому одним із важливих напрямків роботи фахівців у сфері охорони психічного здоров’я є психоедукація та сексологічна освіченість пацієнтів із соматичним захворюванням із метою зняття стресової напруги та для забезпечення вільного вираження своїх сексуальних почуттів та задоволення сексуальних потреб навіть у стані ослабленого фізичного здоров’я.
ГЕНЕЗИС ЗАКОНОДАВСТВА УКРАЇНИ ЩОДО ПРАВ ТА ОБОВ’ЯЗКІВ БАТЬКІВ З ВИХОВАННЯ ДИТИНИ
Authors: Резвова Ольга
Published: January 2020

На сучасному етапі розвитку суспільства, надзвичайної актуальності набуває проблема правового регулювання відносин, що виникають у сфері реалізації й захисту прав та обов’язків батьків щодо виховання дитини в сімейному законодавстві України. В цілому огляд даної статті показує, що проблеми реалізації та захисту прав та обов’язків батьків щодо виховання дитини не піддавалися системному аналізу та комплексному науковому вивченню. Вищезазначене засвідчує актуальність теоретичного аналізу правової оцінки різних видів суспільних правовідносин у вказаній сфері, визначає коло питань, передбачених до розгляду, а також пріоритетні напрямки дослідження. Останніми роками правовому статусу дитини, зокрема її правам, на законодавчому рівні приділяється велика увага. Про це може свідчити навіть факт імплементації низки міжнародно-правових актів у національне законодавство України. На рівні міжнародно-правових актів шляхом покладення обов’язків на держав-учасниць конвенцій передбачається якісна охорона та захист прав дитини. В даній статті проаналізовано як генезис законодавства України щодо прав та обов’язків батьків з виховання дитини так і виявлено ключові проблеми формування та реалізації державної політики в цій сфері. Також досліджено обставини, які нівелюють гарантоване право дитини на належне утримання, забезпечення її майнових інтересів належним чином та способом, так і права, свободи та обов’язки батьками дитини виховувати її. Оскільки діти є однією з визначальних концепцій, що лежать в основі як міжнародних так і національних правових актів, становить фундамент правового статусу дитини, є вихідним положенням у правовому регулюванні відносин у сім'ї, навчальних закладах та інших відносин, одним із учасників яких є дитина.  Відсутність законодавчого закріплення визначення людської гідності дитини ускладнює процес реалізації прав та свобод дитини, сприяє використанню прав батьків, опікунів тощо всупереч їх цільового призначення.
Znienawidzeni przez świat, ukochani przez Chrystusa
Authors: Krynicka Tatiana
Published: January 2020

Żyjący w pierwszych stuleciach chrześcijaństwa wyznawcy Chrystusa byli lojalnymi obywatelami i darzyli wszystkich braterską miłością. Mimo to pozostawali wrogami wśród współobywateli. Potwierdzenie tego znajdujemy w zbiorku Prudencjusza Peristephanon (Wieńce męczeńskie). Wśród bohaterów poety są Emeteriusz i Chelidoniusz, dwaj żołnierze (1), nielubiany nauczyciel Kasjan (9) oraz Eulalia, dziewczyna rozkochana w Bogu (3). Podążając do zjednoczenia z Bogiem, oddalają się oni od świata, który ich otacza i od ludzi, którzy są dla nich ważni, stają się obcy wśród swoich. Jednak w chwili, gdy odnajdują Tego, który mocą swojej krwi niszczy grzech, będący przyczyną wszelkiej wrogości, samotności, wyobcowania, nie są już samotni. W Nim też kochają świat, który dzięki temu ostatecznie przestaje być im obcy.
Wprowadzenie
Authors: Skrzyniarz Ryszard
Published: January 2020

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ОСОБЕННОСТИ СТРАТЕГИЧЕСКОГО ПАРТНЕРСТВА МЕЖДУ РОССИЕЙ И ЕВРОСОЮЗОМ
Authors: Оздоева З.Х. , Мусаева Бэла
Published: January 2020

В статье рассмотрены взаимоотношения Российской Федерации и Европейского Союза как одна из актуальных геополитических проблем современности. И это естественно, ибо от отношений этих субъектов зависит будущее всего европейского субконтинента. Хотя для всех очевидно, что разделительные линии между РФ и другими странами Европы вредны для обеих сторон, тем не менее, они выстроены, в соответствии с надуманными санкциям США, ЕС и других стран. В этих условиях практически невозможно осуществлять региональную интеграцию, вести активное международное сотрудничество. Развитие отношений России и Евросоюза (хотя бы и формально) происходят в формате «стратегического партнерства». В данной статье предпринята попытка определить сущность данного феномена международных отношений, а затем посредством его использования произвести интерпретацию отношений Россия-ЕС на современном этапе.
CRITICAL STUDY OF OPTIMIZATION OF ISLAMIC CORPORATE GOVERNANCE IMPLEMENTATION TO ACHIEVE COMPANY PERFORMANCE
Authors: Pahlevi Reza Widhar
Published: January 2020

Guidelines for Good Corporate Governance an Islamic perspective have a broader context, do notseparate roles and responsibilities in all stakeholders actions under the auspices of Islamic sharia law.There are differences in concepts and perspectives between western perspective (Anglo Saxon andEuropean) Good Corporate Governanceand Islamic perspectives. The difference in the very basic pointof view that Good Corporate Governance is the Islamic perspective comes from tawhid, shari'ah, andthe concept of shura. Islamic Good Corporate Governance guidelines focus on the role of stakeholdersrelated to the company.The development of science that occurs in the perspective of Good Corporate Governance begins onthe basis of agency theory which states that there is a separation between ownership and managementthat has the potential to cause agency problems, ways to overcome agency problems through theimplementation of Good Corporate Governance. Implementation of guidelines for Good CorporateGovernance is an obligation for the company. This is more aimed at the existence of responsibility tothe public (public accountability) relating to the company's operational activities and it is expected thatthe company can comply with the provisions outlined in a positive law. In addition, this is related tothe level of compliance of sharia with sharia principles as described in the Qur'an, Hadith, and Ijma 'ofthe Ulama. Research related to Good Corporate Governance in the Islamic perspective with theachievement of company performance is expected to provide an overview of the Good CorporateGovernance framework that recognizes the rights of stakeholders as determined by law and encouragesactive cooperation between companies and stakeholders to create employee welfare, performance, andcorporate sustainability.
Lexicalization and Complexity in Economic Community of West African States (ECOWAS) Peacekeeping Agreements
Authors: Bello-Osagie Vivien , Kevin Prof. Nwogu N.
Published: January 2020

The paper seeks to establish the level of lexical complexity in the discourse of Economic Community of West African States (ECOWAS) peacekeeping agreements (EPKA) and to describe the lexical strategies through which the observed complexity is created. Many studies on linguistic complexity focus on second language acquisition, assessment and writing development. But, this article focuses on lexical choices that create complexity capable of hindering reader’s comprehension. It utilizes quantitative and qualitative designs in its analysis of corpus which consists of ten purposively selected EPKA texts. The data are analysed using Web-based Lexical Complexity Analyzer. The findings indicate that the language of the EPKA is complex. The complexity is attributed to high lexical density, lengthy words and long sentences in the corpus. Also, a large proportion of words in the corpus are redundant and vague. It is hoped that this article provides information about the lexical choices needed to improve the discourse of peacekeeping agreements.
(POST)COLONIAL DISCOURSE AND THE IRISH SELF IN THE WRITINGS OF J.S. LEFANU
Authors: Jorge Richard
Published: January 2020

It is widely accepted that the relationships of dominance between the self and the other are concurrent to both the Gothic genre and postcolonial theory. In Gothic literature this relationship has traditionally been expressed through the dichotomy self vs. other, in which the self is the male protagonist while the latter is “everything else in that world” (Day 19), Gothic literature being, thus, an exploration of the formation of identity. In colonial Gothic this is brought under the axiom colonizer-colonized, and, therefore, characters are analysed as manifestations of a dichotomy which usually links first the other to the monstrous, who is subsequently presented as the colonized subject. The Irish case further complicates this simple binary relation. The running argument of the present paper is that far from being a dichotomy, the Irish case is better understood as a triangle in which two of its vertices are fixed—Catholics/Irish and English—while the third vertex, that of the Anglo-Irish, gradually shifts positions from the English to the Irish one, following a creolization process in which they are both victims and victimizers. The characters in the fictions of J.S. Le Fanu all epitomize this constrained relationship, displaying an array of roles who do not comfortably fit into either category, showing a pervading feeling of being ill-at-ease. As this paper shows, a deeper reading reveals these figures to be just the opposite of what the prototypical colonialist figure ought to be—weak and feeble, terrorized rather than terrorizer, in awe of the other instead of subduing it.
Silence in Pinter’s Silence and The Dumb Waiter
Authors: Marrouchi Moez
Published: January 2020

The Silences and pauses, Harold Pinter has employed in his plays, have remarkably encapsulated his mastery of such theatrically effective techniques. It is not just a moment when characters keep silent and the audience cannot hear their utterances; it is a moment so pregnant with meanings that the reader finds it difficult to find his way to the final meaning. Silence in a Pinter play is unexpectedly never silent. When it pervades one has to think deeply of that moment. And when characters stop talking one needs to contemplate their unsaid thoughts. In his paper, I would like to make clear that my intention is to investigate the notions of fear, uncertainty, menace and death evoked when characters pause or keep silent in Pinter’s Silence and The Dumb Waiter. In other words, it is how those moments of silence mark a state of calmness on the one hand and how this state gives way to those of fear and eventually death on the other that I would like to explore and expound in the course of this analysis.
Pakistan’s Internal Security Dynamics: Way Forward
Authors: Hussain Sargana Dr. Tauqeer , Hussain Sargana Dr. Mujahid , Saud Muhammad
Published: January 2020

Internal security is the source of strength of any country, which directly impacts her foreign relations, economy, political stability, military strength, national morale, and social values. On the contrary, a state that is internally vulnerable runs a high risk of disintegration, and history is replete with such states. Pakistan is presently passing through probably the worst time of her history. It is confronted with numerous internal and external challenges that are impacting on her national security spectrum. Every country needs a strong, viable and sustainable socio-economic variable for growth. Internal security requires harnessing and orchestrating all elements of national power to achieve the desired results and no single instrument can work, therefore political process backed up by effective force structures, supplemented by economic initiatives and cooperation of regional and international players operating in the area is the solution to the current crisis. Based on the contemporary challenges that Pakistan is facing this article examines the dynamics of internal security and associated challenges impacting the national security of Pakistan. This study makes a point that it’s not only the internal faultiness that punctures the systematic approach rather the global and regional political environment that causes perpetual instability. The research is deductive in nature and uses a mixed-method approach to provide remedial strategies.
Relationship between Television Violence and Social Aggression a Study Conducted on Youth of Rural Areas of Punjab
Authors: Qadir Muhammad Irfan , Jullandhry Professor Dr. Shafiq
Published: January 2020

This study investigates the relationship between television violence and the social aggression of youth of rural areas of Punjab. This study is helpful to examine the exposure and attitude toward television violence of rural area youth of Punjab. This study also examined the impact of television violence on the social aggression of youth. Cross-sectional research design is used in this study and data was collected from the youth of the rural areas of nine divisions of Punjab. A total of 344 respondents were taken as sample size and a stratified sampling technique is used for data collection from the concerned population. The results of this study are generated through statistical software SPSS and Smart PLS. It was hypothesized that exposure toward television violence and the social aggression of youth have a positive relationship. The statistical test results show positive relationship among all hypotheses. So findings of the study help to conclude that exposure, attitude, and cognition toward television violence has an impact on the social aggression of youth of rural areas of Punjab.
Asas Prioritas Dalam Al-Maqashid Al-Syar’iah
Authors: Bakry Muammar M.
Published: January 2020

Maqashid syari’ah adalah konsep yang terpadu dalam tatanan nilai mencakup visi dan misi agama Islam. Konsep tersebut adalah hasil ijtihad jumhur ulama setelah mengadakan pengamatan mendalam terhadap al-Qur’an dan Hadis Rasulullah. Di dalamnya mengandung perintah yang bernilai wajib untuk senantiasa dijaga, di saat yang sama juga menjadi hak asasi bagi setiap manusia untuk dimiliki dan dinikmati. Kewajiban dan hak terpadu dalam konsep ini yang sudah barang tentu ada skala prioritas dari tingkatan-tingkatannya.
Pertanggungjawaban Pidana Penerimaan Gaji Aparatur Sipil Negara Secara Ilegal Dalam Tindak Pidana Korupsi
Authors: Suhartono Arif , Karim M. Said , Riza Marwati
Published: January 2020

Penelitian ini bertujuan untuk menganalisis hak atas gaji pegawai negeri sipil yang sedang menjalani proses hukum serta menganalisis kualifikasi tindak pidana korupsi dalam lingkup Aparatur Sipil Negara. Penelitian ini merupakan penelitian hukum normatif dengan pendekatan peraturan perundang-undangan dan kasus. Lokasi penelitian dilakukan di wilayah hukum Kejaksaan Negeri Soppeng dan SKPD Kabupaten Soppeng, Sulawesi Selatan. Hasil penelitian menunjukkan bahwa hak atas gaji dan tunjangan pegawai negeri sipil yang sedang menjalani proses hukum diatur dalam Pasal 281 PP Nomor 11 Tahun 2017 tentang Manajemen ASN dimana ASN yang diberhentikan sementara karena ditahan sebagai tersangka tidak diberikan penghasilan. Sebaliknya, diberikan uang pemberhentian sementara. Uang pemberhentian sementara diberikan sebesar 50% (lima puluh persen) dari penghasilan jabatan terakhir sebagai ASN sebelum diberhentikan sementara sesuai ketentuan peraturan perundang-undangan. Uang pemberhentian sementara tersebut diberikan pada bulan berikutnya sejak ditetapkannya pemberhentian sementara.
Sistem Pengendalian Inflasi dalam Sistem Ekonomi Islam
Authors: Samsul Samsul , Hamid Najamuddin Mara , Nasution Hotman Guba
Published: January 2020

Penelitian ini bertujuan untuk mengetahui bagaimana sistem pengendalian inflasi dalam ekonomi Islam, dengan menggunakan metode kualitatif, disajikan dalam bentuk deskriptif dari hasil studi kepustakaan (library research) literatur-literatur tertulis. Ekonomi Islam sebagai sistem perekonomian mempunyai cara dan strategi tersendiri dalam menekan inflasi yang jauh berbeda dengan sistem ekonomi lainnya. Ekonomi Islam menyetujui kebijakan moneter dan fiskal sebagai bagian dan upaya menekan inflasi. Akan tetapi untuk mencapai norma keadilan sosioekonomi perlu ada upaya untuk menjaga stabilitas harga, melalui strategi perbaikan moral, distribusi pendapatan dan kekayaan yang merata, serta penghapusan riba.
Implementasi Pembiayaan Akad Mudharabah dan Musyarakah serta Kontribusinya Meningkatkan Perekonomian Anggota BMT
Authors: Muslimin Supriadi , Jafar Wardah
Published: January 2020

Penelitian dilakukan dengan menggunakan kombinasi penelitian kepustakaan dan penelitian lapangan dengan metode kualitatif yang dilakukan dengan analisis deskriptif. Penelitian dilakukan pada BMT Kelompok Usaha Bersama Sejahtera 036 di Kecamatan Maccini Gusung, Makassar. Pendekatan penelitian yang digunakan adalah teologi normatif, fenomenologi, dan ekonomi Islam. Metode pengumpulan data meliputi wawancara, observasi, dan dokumentasi yang kemudian dianalisis melalui beberapa tahap: reduksi data, penyajian data, dan penarikan kesimpulan. Hasil penelitian menunjukkan bahwa: (1) pembiayaan kontrak mudharabah yang dilakukan oleh BMT KUBE Sejahtera 036 sesuai dengan konsep dasar transaksi mudharabah, sebagaimana diatur dalam fatwa DSN-MUI No. 07 Tahun 2000, kemudian kontrak musyarakah Pembiayaan yang dijalankan oleh BMT sejalan dengan konsep dasar transaksi musyarakah sebagai ketentuan fatwa DSN No. 8 Tahun 2000. Dari analisis implementasi pembiayaan mudharabah dan musyarakah di BMT KUBE, sangat relevan dengan prinsip-prinsip ekonomi Islam, mulai dari dari prinsip dasar dan dasar ekonomi Islam. Selain itu, unsur-unsur kepercayaan mencakup beberapa aspek seperti tanggung jawab, menjaga kepercayaan, melestarikan, memberikan. (2) Kontribusi pembiayaan kontrak mudharabah dan musyarakah dalam meningkatkan ekonomi masyarakat. Hasil analisis yang diperoleh dalam hal pelanggan bisnis BMT KUBE memperoleh perkembangan signifikan modal kerja BMT untuk pengembangan bisnis pelanggan. Lebih jauh lagi, pihaknya melakukan kerja sama baik dari segi modal dan manajemen.
Analisis Pemanfaatan harta dalam Konsumsi Masyarakat Ekonomi Konvensional dan Ekonomi Islam
Authors: Samsul Samsul
Published: January 2020

Artikel yang berjudul “Analisis Pemanfaatan Harta dalam Konsumsi Masyarakat (Studi Komparatif Ekomomi Konvensional dan Ekonomi Islam” merupakan metode analisis data deskriptif kualitatif. Metode kualitatif ini digunakan untuk mencari jawaban rumusan masalah bagaimana pemanfaatan harta dalam konsumsi masyarakat perspektif ekonomi konvensional dan ekonomi Islam dan bagaimana konsep konsumsi masyarakat ekonomi konvensional dan ekonomi Islam. Teknik pengumpulan data dari penelitian ini menggunakan studi pustaka yaitu mengumpulkan dan memeriksa atau menelusuri dokumen-dokumen atau kepustakaan seperti buku- buku, skripsi, kamus dan lain sebagainya yang menjadi sumber data primer, skunder, tersier yang dapat memberikan informasi yang dibutuhkan peneliti dan menggunakan pendekatan sosiologis, suatu landasan kajian sebuah studi atau penelitian untuk mempelajari hidup bersama dalam masyarakat. Hasil penelitian ini menunjukkan bahwa pemanfaatan harta terbagi atas dua yaitu pengembangan harta dan penggunaan harta. Penggunaan harta merupakan alat dan sarana untuk melakukan aktivitas konsumsi untuk memenuhi kebutuhan jasmani dan rohani konsumen. Penggunaan harta dalam aktivitas konsumsi ekonomi konvensional merupakan kebebasan untuk mencapai kepuasan sedangkan dalam ekonomi Islam belanja untuk keperluan yang sifatnya konsumtif ini tetap diatur oleh hukum syari’at sehingga ada yang dibolehkan syari’at ada juga belanja yang diharamkan oleh syari’at. Ekonomi konvensional kebutuhan ditentukan oleh konsep kepuasan (utility) sedangkan dalam ekonomi Islam kebutuhan ditentukan oleh konsep mashlahah yang bertujuan untuk mencapai falah (kejayaan di dunia dan di akhirat) sedangkan dalam ekonomi konvensional kepuasan hanya diperuntukan untuk dunia.
Intra-Articular Injection of an Extracellular Vesicle Isolate to Treat Shoulder Osteoarthritis in an Athlete
Authors: Dordevic Maxwell
Published: January 2020

Cadaver and radiographic studies have demonstrated shoulder osteoarthritis (OA) in up to 33% of patients over the age of 60. Patients that present with shoulder OA have pain, crepitus and loss of glenohumeral motion. Limiting the ability to place your hand where you desire severely impairs activities of daily living. The nonsurgical treatments for shoulder OA, include shoulder exercises, the use of analgesics and non-steroidal anti-inflammatory medications. If these non-surgical treatments fail to relieve the OA impairment, the surgical treatment is total shoulder arthroplasty (TSA).
New Optimal Constant Weight Codes
Authors: Gashkov I. , Taub D.
Published: January 2020

In 2006, Smith et al. published a new table of constant weight codes, updating existing tables originally created by Brouwer et al. This paper improves upon these results by filling in 9 missing constant weight codes, all of which are optimal by the second Johnson bound. This completes the tables for $A(n,16,9)$ and $A(n,18,10)$ up to $n=63$ and corrects some $A(n,14,8)$.
The Complexity of Constructing Gerechte Designs
Authors: Vaughan E. R.
Published: January 2020

Gerechte designs are a specialisation of latin squares. A gerechte design is an $n\times n$ array containing the symbols $\{1,\dots,n\}$, together with a partition of the cells of the array into $n$ regions of $n$ cells each. The entries in the cells are required to be such that each row, column and region contains each symbol exactly once. We show that the problem of deciding if a gerechte design exists for a given partition of the cells is NP-complete. It follows that there is no polynomial time algorithm for finding gerechte designs with specified partitions unless P=NP.
Semiaffine Spaces
Authors: Van Maldeghem Hendrik
Published: January 2020

In this paper we improve on a result of Beutelspacher, De Vito & Lo Re, who characterized in 1995 finite semiaffine spaces by means of transversals and a condition on weak parallelism. Basically, we show that one can delete that condition completely. Moreover, we extend the result to the infinite case, showing that every plane of a planar space with at least two planes and such that all planes are semiaffine, comes from a (Desarguesian) projective plane by deleting either a line and all of its points, a line and all but one of its points, a point, or nothing.
Fractional Biclique Covers and Partitions of Graphs
Authors: Watts Valerie L.
Published: January 2020

A biclique is a complete bipartite subgraph of a graph. This paper investigates the fractional biclique cover number, $bc^*(G)$, and the fractional biclique partition number, $bp^*(G)$, of a graph $G$. It is observed that $bc^*(G)$ and $bp^*(G)$ provide lower bounds on the biclique cover and partition numbers respectively, and conditions for equality are given. It is also shown that $bc^*(G)$ is a better lower bound on the Boolean rank of a binary matrix than the maximum number of isolated ones of the matrix. In addition, it is noted that $bc^*(G) \leq bp^*(G) \leq \beta^*(G)$, the fractional vertex cover number. Finally, the application of $bc^*(G)$ and $bp^*(G)$ to two different weak products is discussed.
Plethysm for Wreath Products and Homology of Sub-Posets of Dowling Lattices
Authors: Henderson Anthony
Published: January 2020

We prove analogues for sub-posets of the Dowling lattices of the results of Calderbank, Hanlon, and Robinson on homology of sub-posets of the partition lattices. The technical tool used is the wreath product analogue of the tensor species of Joyal.
Total 4-Choosability of Series-Parallel Graphs
Authors: Woodall Douglas R.
Published: January 2020

It is proved that, if $G$ is a $K_4$-minor-free graph with maximum degree 3, then $G$ is totally 4-choosable; that is, if every element (vertex or edge) of $G$ is assigned a list of 4 colours, then every element can be coloured with a colour from its own list in such a way that every two adjacent or incident elements are coloured with different colours. Together with other known results, this shows that the List-Total-Colouring Conjecture, that ${\rm ch}"(G) = \chi"(G)$ for every graph $G$, is true for all $K_4$-minor-free graphs and, therefore, for all outerplanar graphs.
Edge and Total Choosability of Near-Outerplanar Graphs
Authors: Hetherington Timothy J. , Woodall Douglas R.
Published: January 2020

It is proved that, if $G$ is a $K_4$-minor-free graph with maximum degree $\Delta \ge 4$, then $G$ is totally $(\Delta+1)$-choosable; that is, if every element (vertex or edge) of $G$ is assigned a list of $\Delta+1$ colours, then every element can be coloured with a colour from its own list in such a way that every two adjacent or incident elements are coloured with different colours. Together with other known results, this shows that the List-Total-Colouring Conjecture, that ${\rm ch}"(G) = \chi"(G)$ for every graph $G$, is true for all $K_4$-minor-free graphs. The List-Edge-Colouring Conjecture is also known to be true for these graphs. As a fairly straightforward consequence, it is proved that both conjectures hold also for all $K_{2,3}$-minor free graphs and all $(\bar K_2 + (K_1 \cup K_2))$-minor-free graphs.
The Positive Minimum Degree Game on Sparse Graphs
Authors: Balogh József , Pluhár András
Published: January 2020

In this note we investigate a special form of degree games defined by D. Hefetz, M. Krivelevich, M. Stojaković and T. Szabó. Usually the board of a graph game is the edge set of $K_n$, the complete graph on $n$ vertices. Maker and Breaker alternately claim an edge, and Maker wins if his edges form a subgraph with prescribed properties; here a certain minimum degree. In the special form the board is no longer the whole edge set of $K_n$, Maker first selects as few edges of $K_n$ as possible in order to win, and our goal is to compute the necessary size of that board. Solving a question of Hefetz et al., we show, using the discharging method, that the sharp bound is around $10n/7$ for the positive minimum degree game.
On Ryser's conjecture
Authors: Haxell P. E. , Scott A. D.
Published: January 2020

Motivated by an old problem known as Ryser's Conjecture, we prove that for $r=4$ and $r=5$, there exists $\epsilon>0$ such that every $r$-partite $r$-uniform hypergraph $\cal H$ has a cover of size at most $(r-\epsilon)\nu(\cal H)$, where $\nu(\cal H)$ denotes the size of a largest matching in $\cal H$.
On the Number of Hamilton Cycles in Pseudo-Random Graphs
Authors: Krivelevich Michael
Published: January 2020

We prove that if $G$ is an $(n,d,\lambda)$-graph (a $d$-regular graph on $n$ vertices, all of whose non-trivial eigenvalues are at most $\lambda)$ and the following conditions are satisfied:$\frac{d}{\lambda}\ge (\log n)^{1+\epsilon}$ for some constant $\epsilon>0$; $\log d\cdot \log\frac{d}{\lambda}\gg \log n$, then the number of Hamilton cycles in $G$ is $n!\left(\frac{d}{n}\right)^n(1+o(1))^n$.
A Lower Bound for Schur Numbers and Multicolor Ramsey Numbers
Authors: Exoo Geoffrey
Published: January 2020

For $k \geq 5$, we establish new lower bounds on the Schur numbers $S(k)$ and on the k-color Ramsey numbers of $K_3$.
Explicit Ramsey graphs and orthonormal labelings
Authors: Alon Noga
Published: January 2020

We describe an explicit construction of triangle-free graphs with no independent sets of size $m$ and with $\Omega(m^{3/2})$ vertices, improving a sequence of previous constructions by various authors. As a byproduct we show that the maximum possible value of the Lovász $\theta$-function of a graph on $n$ vertices with no independent set of size $3$ is $\Theta(n^{1/3})$, slightly improving a result of Kashin and Konyagin who showed that this maximum is at least $\Omega(n^{1/3}/ \log n)$ and at most $O(n^{1/3})$. Our results imply that the maximum possible Euclidean norm of a sum of $n$ unit vectors in $R^n$, so that among any three of them some two are orthogonal, is $\Theta(n^{2/3})$.
Three generalizations of Weyl's denominator formula
Authors: Simpson Todd
Published: January 2020

We give combinatorial proofs of three identities, each of which generalizes Weyl's denominator formula for two of the three root systems $B_n$, $C_n$, $D_n$. Two of the three identities are due to S. Okada; the third appears in the author's doctoral thesis, upon which this work is based. Each of the identities we prove has a "sum side" and a "product side"; both sides are polynomials in several commuting indeterminates. We use weighted digraphs to represent the terms on each side; the set of such digraphs that corresponds to the sum side is a proper subset of the set corresponding to the product side.
Enumeration by Stabilizer Class of Patterns with Local Restrictions
Authors: Morris Ifor , Wensley Christopher D.
Published: January 2020

We consider patterns of colourings of G-sets where certain forbidden sub-colourings are excluded. An algorithm is developed for the calculation of inventories of patterns with a prescribed stabilizer class.
Admissible Functions and Asymptotics for Labelled Structures by Number of Components
Authors: Bender Edward A. , Richmond L. Bruce
Published: January 2020

Let $a(n,k)$ denote the number of combinatorial structures of size $n$ with $k$ components. One often has $\sum_{n,k} a(n,k)x^ny^k/n! = \exp\{yC(x)\}$, where $C(x)$ is frequently the exponential generating function for connected structures. How does $a(n,k)$ behave as a function of $k$ when $n$ is large and $C(x)$ is entire or has large singularities on its circle of convergence? The Flajolet-Odlyzko singularity analysis does not directly apply in such cases. We extend some of Hayman's work on admissible functions of a single variable to functions of several variables. As applications, we obtain asymptotics and local limit theorems for several set partition problems, decomposition of vector spaces, tagged permutations, and various complete graph covering problems.
The Robinson-Schensted Correspondence as the Quantum Straightening at $Q=0$
Authors: Leclerc Bernard , Thibon Jean-Yves
Published: January 2020

We show that the quantum straightening for Young tableaux and Young bitableaux reduces in the crystal limit $q \mapsto 0$ to the Robinson-Schensted correspondence.
The Fraction of Subspaces of $\mathrm{GF}(q)^n$ with a Specified Number of Minimal Weight Vectors is Asymptotically Poisson
Authors: Bender Edward A. , Canfield E. Rodney
Published: January 2020

The weight of a vector in the finite vector space $\mathrm{GF}(q)^n$ is the number of nonzero components it contains. We show that for a certain range of parameters $(n,j,k,w)$ the number of $k$-dimensional subspaces having $j(q-1)$ vectors of minimum weight $w$ has asymptotically a Poisson distribution with parameter $\lambda={n\choose w}(q-1)^{w-1}q^{k-n}$. As the Poisson parameter grows, the distribution becomes normal.
Codes, Lattices and Steiner Systems
Authors: Solé Patrick
Published: January 2020

Two classification schemes for Steiner triple systems on 15 points have been proposed recently: one based on the binary code spanned by the blocks, the other on the root system attached to the lattice affinely generated by the blocks. It is shown here that the two approaches are equivalent.
Short Certificates for Tournaments
Authors: Alon Noga , Ruszinkó Miklós
Published: January 2020

An isomorphism certificate of a labeled tournament $T$ is a labeled subdigraph of $T$ which together with an unlabeled copy of $T$ allows the errorless reconstruction of $T$. It is shown that any tournament on $n$ vertices contains an isomorphism certificate with at most $n \log_2 n$ edges. This answers a question of Fishburn, Kim and Tetali. A score certificate of $T$ is a labeled subdigraph of $T$ which together with the score sequence of $T$ allows its errorless reconstruction. It is shown that there is an absolute constant $\epsilon >0$ so that any tournament on $n$ vertices contains a score certificate with at most $ ({1/2}-\epsilon)n^2$ edges.
The Alternating Sign Matrix Polytope
Authors: Striker Jessica
Published: January 2020

We define the alternating sign matrix polytope as the convex hull of $n\times n$ alternating sign matrices and prove its equivalent description in terms of inequalities. This is analogous to the well known result of Birkhoff and von Neumann that the convex hull of the permutation matrices equals the set of all nonnegative doubly stochastic matrices. We count the facets and vertices of the alternating sign matrix polytope and describe its projection to the permutohedron as well as give a complete characterization of its face lattice in terms of modified square ice configurations. Furthermore we prove that the dimension of any face can be easily determined from this characterization.
Tight Upper Bounds for the Domination Numbers of Graphs with Given Order and Minimum Degree
Authors: Clark W. Edwin , Dunning Larry A.
Published: January 2020

Let $\gamma(n,\delta)$ denote the maximum possible domination number of a graph with $n$ vertices and minimum degree $\delta$. Using known results we determine $\gamma(n,\delta)$ for $\delta = 0, 1, 2, 3$, $n \ge \delta + 1$ and for all $n$, $\delta$ where $\delta = n-k$ and $n$ is sufficiently large relative to $k$. We also obtain $\gamma(n,\delta)$ for all remaining values of $(n,\delta)$ when $n \le 14$ and all but 6 values of $(n,\delta)$ when $n = 15$ or 16.
On cycles in the coprime graph of integers
Authors: Erdős Paul , Sarkozy Gabor N.
Published: January 2020

In this paper we study cycles in the coprime graph of integers. We denote by $f(n,k)$ the number of positive integers $m\leq n$ with a prime factor among the first $k$ primes. (If $6|n,$ then $f(n,2)={{2n}\over {3}} $.) We show that there exists a constant $c$ such that if $A\subset \{1, 2, \ldots , n\}$ with $|A| > f(n,2),$ then the coprime graph induced by $A$ not only contains a triangle, but also a cycle of length $2 l + 1$ for every positive integer $l\leq c n .$
On a Tiling Scheme from M.C.Escher
Authors: Davis Dan
Published: January 2020

Escher studied certain tilings by decorated square tiles arranged into $2\times 2$ supertiles which are copied and translated to fill the plane. It is found that there are exactly 154 such tilings, if reflections of the tilings are allowed. Illustrations of all of them are presented.
Lattice walks in $Z^d$ and permutations with no long ascending subsequences
Authors: Gessel Ira , Weinstein Jonathan , Wilf Herbert S.
Published: January 2020

We identify a set of $d!$ signed points, called Toeplitz points, in ${{Z}}^d$, with the following property: for every $n>0$, the excess of the number of lattice walks of $n$ steps, from the origin to all positive Toeplitz points, over the number to all negative Toeplitz points, is equal to ${n\choose n/2}$ times the number of permutations of $\{1,2,\dots ,n\}$ that contain no ascending subsequence of length $>d$. We prove this first by generating functions, using a determinantal theorem of Gessel. We give a second proof by direct construction of an appropriate involution. The latter provides a purely combinatorial proof of Gessel's theorem by interpreting it in terms of lattice walks. Finally we give a proof that uses the Schensted algorithm.
An improved bound on the minimal number of edges in color-critical graphs
Authors: Krivelevich Michael
Published: January 2020

A graph $G$ is $k$-color-critical (or simply $k$-critical) if $\chi(G)=k$ but $\chi(G') < k$ for every proper subgraph $G'$ of $G$, where $\chi(G)$ denotes the chromatic number of $G$. Consider the following problem: given $k$ and $n$, what is the minimal number of edges in a $k$-critical graph on $n$ vertices? It is easy to see that every vertex of a $k$-critical graph $G$ has degree at least $k-1$, implying $|E(G)|\geq {{k-1}\over {2}}|V(G)|$. Gallai improved this trivial bound to $|E(G)|\geq {{k-1}\over {2}}+{{k-3}\over {2(k^2-3)}}|V(G)|$ for every $k$-critical graph $G$ (where $k\geq 4$), which is not a clique $K_k$ on $k$ vertices. In this note we strengthen Gallai's result by showing Theorem Suppose $k\geq 4$, and let $G=(V,E)$ be a $k$-critical graph on more than $k$ vertices. Then $ |E(G)|\geq ({{k-1}\over {2}}+{{k-3}\over {2(k^2-2k-1)}})|V(G)| $
Increasing Subsequences and the Classical Groups
Authors: Rains E. M.
Published: January 2020

We show that the moments of the trace of a random unitary matrix have combinatorial interpretations in terms of longest increasing subsequences of permutations. To be precise, we show that the $2n$-th moment of the trace of a random $k$-dimensional unitary matrix is equal to the number of permutations of length $n$ with no increasing subsequence of length greater than $k$. We then generalize this to other expectations over the unitary group, as well as expectations over the orthogonal and symplectic groups. In each case, the expectations count objects with restricted "increasing subsequence" length.
Perfect Matchings in $\epsilon$-regular Graphs
Authors: Alon Noga , Rödl Vojtech , Ruciński Andrzej
Published: January 2020

A super $(d,\epsilon)$-regular graph on $2n$ vertices is a bipartite graph on the classes of vertices $V_1$ and $V_2$, where $|V_1|=|V_2|=n$, in which the minimum degree and the maximum degree are between $ (d-\epsilon)n$ and $ (d+\epsilon) n$, and for every $U \subset V_1, W \subset V_2$ with $|U| \geq \epsilon n$, $|W| \geq \epsilon n$, $|{{e(U,W) }\over{|U||W|}}-{{e(V_1,V_2)}\over{|V_1||V_2|}}| < \epsilon.$ We prove that for every $1>d >2 \epsilon >0$ and $n>n_0(\epsilon)$, the number of perfect matchings in any such graph is at least $(d-2\epsilon)^n n!$ and at most $(d+2 \epsilon)^n n!$. The proof relies on the validity of two well known conjectures for permanents; the Minc conjecture, proved by Brégman, and the van der Waerden conjecture, proved by Falikman and Egorichev.
On Noncrossing and Nonnesting Partitions for Classical Reflection Groups
Authors: Athanasiadis Christos A.
Published: January 2020

The number of noncrossing partitions of $\{1,2,\ldots,n\}$ with fixed block sizes has a simple closed form, given by Kreweras, and coincides with the corresponding number for nonnesting partitions. We show that a similar statement is true for the analogues of such partitions for root systems $B$ and $C$, defined recently by Reiner in the noncrossing case and Postnikov in the nonnesting case. Some of our tools come from the theory of hyperplane arrangements.
On a Conjecture Concerning Dyadic Oriented Matroids
Authors: Scobee Matt
Published: January 2020

A rational matrix is totally dyadic if all of its nonzero subdeterminants are in $\{\pm 2^k\ :\ k \in {\bf Z}\}$. An oriented matriod is dyadic if it has a totally dyadic representation $A$. A dyadic oriented matriod is dyadic of order $k$ if it has a totally dyadic representation $A$ with full row rank and with the property that for each pair of adjacent bases $A_1$ and $A_2$ $$2^{-k} \le \left| { {\det(A_1)} \over {\det(A_2)}}\right|\le 2^k.$$ In this note we present a counterexample to a conjecture on the relationship between the order of a dyadic oriented matroid and the ratio of agreement to disagreement in sign of its signed circuits and cocircuits (Conjecture 5.2, Lee (1990)).
The Grötzsch Theorem for the Hypergraph of Maximal Cliques
Authors: Mohar Bojan , Skrekovski Riste
Published: January 2020

In this paper, we extend the Grötzsch Theorem by proving that the clique hypergraph ${\cal H}(G)$ of every planar graph is 3-colorable. We also extend this result to list colorings by proving that ${\cal H}(G)$ is 4-choosable for every planar or projective planar graph $G$. Finally, 4-choosability of ${\cal H}(G)$ is established for the class of locally planar graphs on arbitrary surfaces.
A Combinatorial Interpretation of the Area of Schröder Paths
Authors: Pergola E. , Pinzani R.
Published: January 2020

An elevated Schröder path is a lattice path that uses the steps $(1,1)$, $(1,-1)$, and $(2,0)$, that begins and ends on the $x$-axis, and that remains strictly above the $x$-axis otherwise. The total area of elevated Schröder paths of length $2n+2$ satisfies the recurrence $f_{n+1}=6f_n-f_{n-1}$, $n \geq 2$, with the initial conditions $f_0=1$, $f_1=7$. A combinatorial interpretation of this recurrence is given, by first introducing sets of unrestricted paths whose cardinality also satisfies the recurrence relation and then establishing a bijection between the set of these paths and the set of triangles constituting the total area of elevated Schröder paths.
A Multiple Integral Evaluation Inspired by the Multi-WZ Method
Authors: Tefera Akalu
Published: January 2020

We give an integral identity which was conjectured and proved by using the continuous version of the multi-WZ method.
Random Sampling of Labeled Tournaments
Authors: McShine Lisa
Published: January 2020

This note extends a recent result of Kannan, Tetali and Vempala to completely solve, via a simple proof, the problem of random generation of a labeled tournament chain on the set of labeled tournaments with the same score vector.
Enumerating Permutations that Avoid Three Term Arithmetic Progressions
Authors: Sharma Arun
Published: January 2020

It is proved that the number of permutations of the set $\{1, 2, \dots, n\}$ that avoid three term arithmetic progressions is at most ${(2.7)^n} \over 21$ for $n \ge 11$ and at each end of any such permutation, at least ${\lfloor {n \over 2} \rfloor} - 6$ entries have the same parity.
The Hamiltonian p–Median Problem
Authors: Glaab Holger , Pott Alexander
Published: January 2020

We deal, from a theoretical point of view, with the asymmetric Hamiltonian $p$–median problem. This problem, which has many applications, can be viewed as a mixed routing location problem. An ILP-formulation based on a new class of inequalities (subtour number constraints) is presented. The associated Hamiltonian $p$–median polytope is examined, in particular its dimension and its affine hull. We determine which of the defining inequalities induce facets.
Continued Fractions and Catalan Problems
Authors: Jani Mahendra , Rieper Robert G.
Published: January 2020

We find a generating function expressed as a continued fraction that enumerates ordered trees by the number of vertices at different levels. Several Catalan problems are mapped to an ordered-tree problem and their generating functions also expressed as a continued fraction. Among these problems is the enumeration of $(132)$-pattern avoiding permutations that have a given number of increasing patterns of length $k$. This extends and illuminates a result of Robertson, Wilf and Zeilberger for the case $k=3$.
A Determinant of the Chudnovskys Generalizing the Elliptic Frobenius-Stickelberger-Cauchy Determinantal Identity
Authors: Amdeberhan Tewodros
Published: January 2020

D.V. Chudnovsky and G.V. Chudnovsky [CH] introduced a generalization of the Frobenius-Stickelberger determinantal identity involving elliptic functions that generalize the Cauchy determinant. The purpose of this note is to provide a simple essentially non-analytic proof of this evaluation. This method of proof is inspired by D. Zeilberger's creative application in [Z1].
Guessing Secrets
Authors: Chung Fan , Graham Ronald , Leighton Tom
Published: January 2020

Suppose we are given some fixed (but unknown) subset $X$ of a set $\Omega$, and our object is to learn as much as possible about the elements of $X$ by asking binary questions. Specifically, each question is just a function $F: \Omega \rightarrow \{0,1\}$, and the answer to $F$ is just the value $F(X_i)$ for some $X_i \in X$, (determined, for example, by a potentially malevolent but truthful, adversary). In this paper, we describe various algorithms for solving this problem, and establish upper and lower bounds on the efficiency of such algorithms.
Asymptotic Bounds for Bipartite Ramsey Numbers
Authors: Caro Yair , Rousseau Cecil
Published: January 2020

The bipartite Ramsey number $b(m,n)$ is the smallest positive integer $r$ such that every (red, green) coloring of the edges of $K_{r,r}$ contains either a red $K_{m,m}$ or a green $K_{n,n}$. We obtain asymptotic bounds for $b(m,n)$ for $m \geq 2$ fixed and $n \rightarrow \infty$.
A Normalization Formula for the Jack Polynomials in Superspace and an Identity on Partitions
Authors: Lapointe Luc , Borgne Yvan Le , Nadeau Philippe
Published: January 2020

We prove a conjecture of Desrosiers, Lapointe and Mathieu giving a closed form formula for the norm of the Jack polynomials in superspace with respect to a certain scalar product. The proof is mainly combinatorial and relies on the explicit expression in terms of admissible tableaux of the non-symmetric Jack polynomials. In the final step of the proof appears an identity on weighted sums of partitions that we demonstrate using the methods of Gessel-Viennot.
Some Aspects of Hankel Matrices in Coding Theory and Combinatorics
Authors: Tamm Ulrich
Published: January 2020

Hankel matrices consisting of Catalan numbers have been analyzed by various authors. Desainte-Catherine and Viennot found their determinant to be $\prod_{1 \leq i \leq j \leq k} {{i+j+2n}\over {i+j}}$ and related them to the Bender - Knuth conjecture. The similar determinant formula $\prod_{1 \leq i \leq j \leq k} {{i+j-1+2n}\over {i+j-1}}$ can be shown to hold for Hankel matrices whose entries are successive middle binomial coefficients ${{2m+1} \choose m}$. Generalizing the Catalan numbers in a different direction, it can be shown that determinants of Hankel matrices consisting of numbers ${{1}\over {3m+1}} {{3m+1} \choose m}$ yield an alternate expression of two Mills – Robbins – Rumsey determinants important in the enumeration of plane partitions and alternating sign matrices. Hankel matrices with determinant 1 were studied by Aigner in the definition of Catalan – like numbers. The well - known relation of Hankel matrices to orthogonal polynomials further yields a combinatorial application of the famous Berlekamp – Massey algorithm in Coding Theory, which can be applied in order to calculate the coefficients in the three – term recurrence of the family of orthogonal polynomials related to the sequence of Hankel matrices.