bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical Muscle Stimulation to Develop and Implement Menstrual Simulator System
Authors: Asada Chihiro , Tsutsumi Kotori , Tamura Yuichi , Hara Naoya , Omori Wataru , Otsuka Yuta , Sato Katsunari ,   Nara Women’s University Kitauoyanishimachi, Nara 630-8506, Japan,   Konan University 8-9-1 Okamoto, Higashinada-ku, Kobe, Hyogo 658-8501, Japan,   Osaka University 1-1 Yamadaoka, Suita, Osaka 658-8501, Japan,   Japan Advanced Institute of Science and Technology 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan,   University of Hyogo 7-1-28 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
Published: October 2021

Menstrual symptoms and cycles are complex, and the associated discomfort is difficult to quantify. Therefore, men, and some women, do not completely understand them. Here, we propose a system that simulates menstruation-like cramps through electrical muscle stimulation (EMS). We conducted an experiment to compare and evaluate the natural and electrically stimulated menstrual cramps. The results show that menstrual cramps using EMS can reproduce the nature of periodic dull pain. However, in this study, the position where the pain occurred was shallow. Furthermore, we constructed a demonstration system based on the proposed method. From the exhibition, we confirmed that this experience can help verbalize menstrual-related discomfort and allow people to better understand menstrual symptoms. In other words, this experience will help eliminate negative perception of menstruation.
Development of Automatic Chair Transport System - Chair Recognition and Approach Strategy –
Authors: Miyauchi Koshiro ,   Department of Mechanical Science and Technology, Graduate School of Science and Technology, Gunma University 29-1 Hon-cho, Ota, Gunma 373-0057, Japan, Nakazawa Nobuaki
Published: October 2021

In schools and other educational institutions, there are many instances that require the arrangement of chairs depending on the required purpose, such as a class or event. Some chairs are on casters; however, educational institutions typically use stacking or folding chairs. Although effective in terms of storage, these must be lifted by hand during transportation, increasing the burden on the workforce. While automation of baggage transport in warehouses has improved significantly, little attention has been paid to the automation of chair transport. Despite the demand and the fact that self-propelled chairs have already been developed, automatic transport of chairs without casters has never been reported. In this study, we constructed an automatic chair-transport system using an omnidirectional mobile robot and focused on a stacking chair that allowed the robot to position itself underneath. The developed system utilizes the image of the seat and frame pipe of the stacking chair to estimate the chair’s position and direction with respect to the robot. Once the robot has positioned itself under the chair, the chair is lifted and transported using a lifter device attached to the robot.
Geometric Correction Method Applying the Holographic Ray Direction Control Technology
Authors: Tanaka Kenta , Sano Motoyasu , Horimai Yumi , Horimai Hideyoshi , Aoki Yusuke ,   National Institute of Technology, Numazu College 3600 Ooka, Numazu, Shizuoka 410-8501, Japan,   Shape in Space LLC 591-17 Kawaharagaya, Mishima, Shizuoka 411-0022, Japan,   HolyMine Corp. 591-17 Kawaharagaya, Mishima, Shizuoka 411-0022, Japan
Published: October 2021

In recent years, there has been an increasing need for larger screens and higher definition displays, while projectors are becoming smaller and cheaper. Furthermore, an ultra-short-throw projector that can display on a large screen while significantly reducing the distance between the projector and screen is being developed. However, ultra-short-throw projectors are required to be precisely aligned with the screen, and if the screen is not flat, the projected image becomes distorted. Therefore, geometric correction projection technology is attracting attention for projection on curtains and the walls of living rooms instead of screens for realizing the correction of distortion during projection with ultra-short-throw projectors, projection mapping, signage, etc. We focused on developing a hologram with perfect command of the ray. Conventional geometry-correction systems are expensive systems that require a personal computer and a camera. In this study, we developed a geometric correction method applying holographic ray direction control technology to control a holographic ray at a low cost and in real time. In this paper, we studied the exposure technology and proposed a ray-direction control technology that combines a scanning laser projector that uses a hologram and a micro electro mechanical systems mirror. We also proposed and demonstrated the basic principle of a holographic surface projector (HSP), which uses hologram geometry correction technology. Finally, we constructed a geometrically corrected hologram exposure system using a depth camera and conducted geometrically corrected projection experiments.
Inter-Module Physical Interactions: A Force-Transmissive Modular Structure for Whole-Body Robot Motion
Authors: Yu Shiqi ,   Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan, Nakata Yoshihiro , Nakamura Yutaka , Ishiguro Hiroshi
Published: October 2021

Robots are required to be significantly compliant and versatile to work in unstructured environments. In a number of studies, robots have positively exploited the environments during interactions and completed tasks from a morphological viewpoint. Modular robots can help realize real-world adaptive robots. Researchers have been investigating the actuation, coupling, and communication mechanisms among these robots to realize versatility. However, the diverse force transmission among modules needs to be further studied to achieve the adaptive whole-body dynamics of a robot. In this study, we fabricated a modular robot and proposed the realization of force transmission on this robot, by constructing fluid transferable network systems on the actuation modules. By exploiting the physical property variations of the modular robot, our experimental results prove that the robot’s motion can be changed by switching the connection pattern of the system.
Nuevos registros del género Gamochaeta (Asteraceae: Gnaphalieae) en Ecuador
Authors: Freire Susana Edith , Monti Claudia , Bayón Néstor D. , Giuliano Daniel A.
Published: October 2021

Gamochaeta cabrerae, G. simplicicaulis y G. subfalcata se citan por primera vez en Ecuador y se confirma la presencia de G. humilis. Estos nuevos registros se suman a las cuatro especies del género conocidas hasta el momento para el país, i.e., G. americana, G. pensylvanica, G. purpurea y G. sphacelata. Para cada uno de los nuevos registros se aporta una descripción, ilustración y mapa de distribución. Además, se incluye una clave del género en Ecuador.
Окислительная активность бентосных бактерий в донных отложениях Карадага и Двуякорной бухты (Черное море)
Authors: Чекалов В. П.
Published: October 2021

Рассмотрено влияние бактериобентосного сообщества на формирование кислородного режима и процессы деструкции органического вещества в зависимости от температуры и редокс условий в придонных системах рыхлых грунтов сопредельных акваторий в районе Карадага (Черное море). Жесткие условия среды в заглубленных донных осадках определяют значительное снижение окислительной активности и численности жизнедеятельной микрофлоры, несмотря на их более высокий деструкционный потенциал при оптимизации условий. Способностью к росту обладала лишь одна из ста клеток активных форм, и каждая пятнадцатая от возможного максимума численности при оптимальной температуре. При этом скорость окисления органических веществ в донных осадках у м. Мальчин при реальных условиях не превышала 1.19 мкг/г∙ч, тогда как в мелководных грунтах Двуякорной бухты составлял 1.82 мкг/г∙ч. Приведены данные о соотношении темпов окисления и продуцирования восстановленных соединений в донных осадках исследуемых районов.
Редкие сосудистые растения во флорах природных комплексов Юго-Восточного Крыма: состояние, степень изученности, проблемы охраны
Authors: Миронова Л. П.
Published: October 2021

В статье представлены результаты многолетних (1979–2018 гг.) исследований редких видов (РВ) флоры природных комплексов (ПК) Юго-Восточного Крыма (ЮВК). Приведен аннотированный список 154 сосудистых растений, внесенных в Красные книги Российской Федерации, Республики Крым и список 105 таксонов, не имеющих в настоящее время государственного статуса охраны, но редких для данного региона. Проведен анализ флоры редких растений ЮВК. Дана оценка состояния, распространения, экологической приуроченности и численности охраняемых РВ, а также оценка флоры ПК ЮВК с использованием индексов концентрации видового разнообразия, редкости видов и эндемизма. Определена степень изученности РВ в конкретных ПК. Рассматриваются некоторые пути решения проблемы сохранения редких представителей флоры ЮВК и фиторазнообразия в целом.
Изучение раннего онтогенеза креветки травяной (Palaemon adspersus Rathke, 1837)
Authors: Зинабадинова С. С. , Кулиш А. В. , Сухаренко Е. В.
Published: October 2021

Исследованы стадии эмбрионального развития наиболее многочисленного и единственного промыслового вида из 43 видов десятиногих ракообразных Азово-Черноморского бассейна – креветки травяной Palaemon adspersus Rathke, 1837. Пробу отбирали в юго-западной части акватории Керченского пролива на прибрежном участке с песчано-илистым грунтом с Zostera sp. Описаны четырестадии эмбрионального развития P. adspersus. В ходе изучения стадий развития – нерестовое яйцо, зародышевый диск, формирование глазного примордия, эмбриональный науплий – определены качественные признакираннего и позднего эмбриогенеза. Установлены эмбриологические маркеры ранних этапов развития – расширение перивителлинового пространства, дифференциация полюсов яйца (формирование зародышевого диска). Выявлено, что на более поздних стадиях развития наиболее информативными являются этапы формирования науплиарных зачатков (антенн, антенулл, мандибул), глазных примордиев (форма пигментного слоя сетчатки, детерминация роговицы), а также метамеризация отделов тела, соотношение неутилизированного зародышем желтка и объема яйца, дифференциация тельсона.
Контрастность годовых инсоляционных температур и тенденции многолетних изменений приповерхностной температуры воздуха
Authors: Федоров В. М.
Published: October 2021

На основе связи широтного распределения годовой инсоляции и приповерхностной температуры воздуха (ПТВ) рассчитаны годовые инсоляционные температуры на период с 1900 по 2016 гг. Показано, что многолетние изменения ПТВ определяются многолетними изменениями контрастности инсоляционных температур и инсоляционной контрастностью. Многолетние изменения инсоляционной контрастности обобщенно (по областям источника и стока тепла) отражают многолетние изменения меридионального градиента инсоляции. Меридиональным градиентом инсоляции регулируется меридиональный перенос тепла в системе океан – атмосфера. Показано, что инсоляционная контрастность линейно связана с наклоном оси вращения Земли. Из этого следует, что многолетнее увеличение аномалии ПТВ и наблюдаемое глобальное потепление климата, в основном, определяются естественными причинами, и связаны с уменьшением наклона оси вращения Земли. Представлена общая схема механизма изменения температурного режима Земли и полушарий. Определено, что при увеличении контрастности инсоляционных температур температурная контрастность в северном полушарии уменьшается, а в южном полушарии увеличивается.
Экскреция тестостерона и эстрадиола культивируемой мидией Mytilus galloprovincialis Lam. (Чёрное море)
Authors: Капранова Л. Л.
Published: October 2021

В работе представлены данные о содержании тестостерона и эстрадиола в гонадах и половых продуктах двустворчатого моллюска Mytilus galloprovincialis, обитающего в Чёрном море, на разных стадиях полового созревания. Рассчитаны концентрации половых гормонов, поступающих в водную среду во время массового нереста вместе с половыми продуктами. Показано, что самцы вместе со спермой экскретируют 0,1 мг тестостерона на 1 тонну мидий. Вместе с яйцеклетками может выделяться до 0,014 мг эстрадиола на 1 т моллюсков. На протяжении жизненного цикла концентрации тестостерона и эстрадиола в гонадах и половых продуктах мидии не постоянны, так как зависят от ряда факторов: сезонности, температуры, размеров гонад, условий выращивания. Тестостерон и эстрадиол, выделяемый вместе с половыми продуктами, активно участвует в жизнедеятельности, как самих мидий, так и других гидробионтов.
Экологическая характеристика степной ценофлоры Карадагского природного заповедника
Authors: Летухова В. Ю. , Потапенко И. Л.
Published: October 2021

На основании анализа собственных и литературных данных дана экологическая характеристика ценофлоры степных сообществ Карадагского заповедника (Крым), в которых отмечено 346 видов сосудистых растений из 200 родов, относящихся к 54 семействам. Преобладающими экологическими группами по отношению к увлажнению являются ксеромезофиты (53.2%) и мезоксерофиты (26,0%). Так как степные сообщества формируются в очень засушливых условиях, к мезофитам относится всего 6,4% видов. Дана эколого-физиологическая классификация ценофлоры по морфолого-анатомическому признаку. Большинство видов имеют те или иные приспособления для перенесения засухи. Из наиболее распространенных отмечены следующие: толстый слой кутикулы, наличие опушения, закупоривание устьичных щелей восковыми и смолистыми веществами, свертывание листьев в трубку, глубокая корневая система. Еще одна группа растений (35,3% видов) избегает засуху благодаря короткому жизненному циклу. Небольшое количество видов (6,6%) предпочитают тенистые места (под кроной деревьев) или северные склоны и большого распространения не получили. В структуре ценофлоры по световому режиму закономерно лидируют гелиофиты (69,1%). По солевому режиму лидируют гликофиты (94,2%), галофиты в основном представлены криногалофитами и галоксерофитами.
Ландшафтные исследования памятника природы «Прибрежный аквальный комплекс у мыса Лукулл»
Authors: Панкеева Т. В. , Миронова Н. В. , Пархоменко А. В.
Published: October 2021

Приведены сведения о ландшафтной структуре гидрологического памятника природы «Прибрежный аквальный комплекс (ПАК) у мыса Лукулл» (западное побережье Крыма, район г. Севастополя). Ландшафтное разнообразие памятника природы обусловлено наличием морских и сухопутных ландшафтов, формирование которых происходит в зоне контакта суши и моря. На формирование его ландшафтной структуры оказывают влияние как природные особенности береговой зоны, так и хозяйственная деятельность на прилегающей территории. Ландшафтные исследования (2019–2020 гг.) проводили методом детального изучения ключевых участков с применением ландшафтного профилирования. В ходе изучения памятника природы была уточнена и детализирована ландшафтная структура сухопутной части и прилегающей территории, выделено три местности, восемь урочищ. Доминируют местности денудационноэрозионных равнин с разнотравно-ковыльно-типчаковыми степями и клифовая ― с активным развитием обвально-оползневых процессов. Впервые составлена ландшафтная карта прибрежной части и прилегающей акватории, выделено три местности, семь урочищ. Для мысов характерны ландшафты подводного склона: сложенного грубооболомочными отложениями с доминированием карподесмии косматой, трептаканты бородатой и сложенного грубообломочными отложениями, где доминирует трептаканта бородатая, с чередованием галечно-гравийных отложений с битой ракушей, где преобладает филлофора курчавая. Между мысами формируются ландшафты подводного склона, сложенные песчаными отложениями и лишённые донной растительности. На отдельных глыбах доминируют карподесмия косматая и трептаканта бородатая или падина павлинья и диктиота ленточная. На основе ландшафтного подхода предложены рекомендации по оптимизации природоохранного режима памятника природы.
Уязвимость региональных экосистем Крымского полуострова
Authors: Горбунов Р. В.
Published: October 2021

На основе данных о потенциальном биологическом разнообразии Крымского полуострова и региональных проявлениях изменения климата получены картографические модели уязвимости региональных экосистем Крымского полуострова к антропогенному воздействию и климатическим изменениям. Описаны пространственные особенности уязвимости региональных экосистем Крымского полуострова.
Пуццоланы и трасс Карадага. История поиска, разработок и изучения
Authors: Шибаев Е. А. , Шибаев И. Е.
Published: October 2021

В статье на основе большого количества первоисточников представлена история поиска и добычи на Карадаге активных минеральных добавок, необходимых для получения гидротехнических бетонов. Рассмотрены основные этапы научных исследований пуццоланы и трасcа, показано изменение взглядов на понимание их образования и состава. Статья содержит фотографии описываемых горных пород в виде шаров, которые максимально передают текстуру камня.
Digital Spectral Analysis by means of the Method of Averag Modified Periodograms Using Binary-Sign Stochastic Quantization of Signals
Authors: Yakimov V. N.
Published: October 2021

The method of averaging modified periodograms is one of the main methods for estimating the power spectral density (PSD). The aim of this work was the development of mathematical and algorithmic support, which can increase the computational efficiency of signals digital spectral analysis by this method.

The solution to this problem is based on the use of binary-sign stochastic quantization for converting the analyzed signal into a digital code. A special feature of this quantization is the use of a randomizing uniformly distributed auxiliary signal as a stochastic continuous quantization threshold (threshold function). Taking into account the theory of discrete-event modeling the result of binary-sign quantization is interpreted as a chronological sequence of instantaneous events in which its values change. In accordance with this we have a set of time samples that uniquely determine the result of binary-sign quantization in discrete-time form. Discrete-event modeling made it possible to discretize the process of calculating PSD estimates. As a result, the calculation of PSD estimates was reduced to discrete processing of the cosine and sine Fourier transforms for window functions. These Fourier transforms are calculated analytically based on the applied window functions. The obtained mathematical equations for calculating the PSD estimates practically do not require multiplication operations. The main operations of these equations are addition and subtraction. As a consequence, the time spent on digital spectral analysis of signals is reduced.

Numerical experiments have shown that the developed mathematical and algorithmic support allows us to calculate the PSD estimates by the method of averaging modified periodograms with a high frequency resolution and accuracy even for a sufficiently low signal-to-noise ratio. This result is especially important for spectral analysis of broadband signals.

The developed software module is a problem-oriented component that can be used as part of metrologically significant software for the operational analysis of complex signals.
EXTERNAL FACTORS AND CONDITIONS OF INNOVATIVE DEVELOPMENT ENTREPRENEURIAL SECTOR OF THE REPUBLIC OF BELARUS
Authors: Baynev V. , Runkov Yu.
Published: October 2021

The article reveals the importance of factors and environmental conditions for the innovative development of economic systems. It is shown that unfavorable macroeconomic conditions give rise to additional, excess costs, which are proposed to be called external business losses. On the basis of the research carried out, it was concluded that the external environment is very unfavorable for business in the countries of the Eurasian Economic Union (EAEU), including the Republic of Belarus. Purposeful improvement of environmental factors and conditions to the level of our competitors should be the main indicator of the effectiveness of the functioning of public institutions of the EAEU and its member states.
THE DEVELOPMENT OF HUMAN AND SOCIAL CAPITAL AS A FACTOR OF ECONOMIC AND SOCIAL SECURITY
Authors: Pastukhov A.
Published: October 2021

The article is devoted to the development of the human capital and the social capital as
factors of economic security and social security in the current socio-economic conditions in the context of globalization.
It presents aspects of the knowledge management and the formation of university complexes as institutional conditions and social environment, ensuring the development of the human capital and the social capital.
What kind of future is humanity facing?
Authors:   Institute of Philosophy, Russian Academy of Sciences, Nikiforov Aleksandr L.
Published: October 2021

The article examines the scenarios for the future development of mankind presented by F. Fukuyama, the Club of Rome and transhumanists. It is shown that all these scenarios predict the future death of humanity. The question of how this can be avoided is dis­cussed. It is noted that all the scenarios mentioned are Eurocentric: they extrapolate the current crisis of European civilization to all humanity. Indeed, the existence of Euro­pean civilization is coming to an end, it decays and dies, infecting the whole world with the miasma of its decay. Now, a major question for Russian philosophers is how to pro­tect Russia from the decay that Western Europe is currently experiencing. The author ar­gues that in developing a project for the future of Russia, one should abandon liberal ide­ology and the capitalist mode of production, the main goal of which is to make profit. We need a new – collectivist – ideology, restriction of private property and market rela­tions. The main task of Russian philosophy at the present time is the development of a new social project, the pursuit of which will give a high meaning to the life of the peo­ple of our country.
Sharp Edges of the Social Ideal (From Old Discussions to the Present)
Authors:   National Research University “Higher School of Economics”, Porus Vladimir N.
Published: October 2021

The author outlines the views on social ideal of Russian thinkers from Vladimir Solovyov to Georgij Fedotov. Solovyov, advancing Fyodor Dostoevsky’s ideas, viewed the social ideal as a realization of the doctrine of universal solidarity and free development of a person under spiritual guidance of the Universal Church. This ecumenic and theocratic utopia had not received any recognition in Russian society, torn apart by unsolvable social and cultural conflicts. Pavel Novgorodtsev, generally sharing on the whole Solovyov’s views, thought that only the constitutional state could put these into effect. Konstantin Pobedonostsev pinned his hopes on monarchy, which would embrace popular religious and cultural traditions and oppose the “destructive” liberal reforms, while Nicolay Berdyaev believed in intelligentsia “transformed” by the idea of freedom. Georgij Fedotov called for the revival of the “need for freedom” and creation of the institutes executing spiritual development of society. The problem of the social ideal is relevant in modern Russia, though discredited by the neglect of cultural values, and above all, the devaluation of personal freedom. The prospect of a new cultural elite to overcome this remains vague.
V.S. Soloviev Between Orthodoxy and Catholicity: Responses of Contemporaries
Authors:   Institute of Philosophy, Russian Academy of Sciences, Vorozhikhina Ksenia V.
Published: October 2021

The article is devoted to the foreign and Russian reception of theocratic utopia of V.S. Soloviev, presented in his French works “The Russian Idea”, “Saint Vladimir and Christian Politics”, “Russia and the Universal Church”. Soloviev’s theocratic project, which assumed the subordination of the Russian emperor to the pope and the reunion of the Orthodox and Catholic churches, aroused great interest abroad. His report “The Russian Idea”, dedicated to Russia’s mission to conciliate the two branches of Christianity, was enthusiastically received by the Catholic press and received many praise. The Russian philosopher was seen by Western critics as a new apostle, called to return the Orthodox to Catholic unity. However, the treatise “Russia and the Universal Church” turned out to be unacceptable for Catholics for its mysticism, Soloviev’s teachings about Sophia and creation seemed like a gnostic heresy. Abroad Soloviev’s ecclesiology, philosophy of history, his theocratic project, which in Russia were perceived as treason to Orthodoxy and as an anti-national utopia, were in demand. Despite the fact that the philosophical and religious foundations of his views were shared by many Soloviev’s French writings evoked an unfavorable impression in the government and the Holy Synod (K.P. Pobedonostsev), indignation and irritation of the Slavophils (I.S. Aksakov, S.F. Sharapov), the Pochvenniks (N.N. Strakhov) and conservative circles (L.A. Tikhomirov); Orthodox clergy (Nikolai (Kasatkin), Anthony (Khrapovitsky), Vladimir (Guettée)) spoke extremely negatively about them. The most favorable were the assessments of K.N. Leontiev and T.I. Filippov. The philosopher’s Russian followers embraced Soloviev’s metaphysics, sophiology, his doctrine of total unity, while in his theocratic aspirations the philosopher remained alone.
A Fast Screening Tool for Assessing the Impact of Poro-Mechanics on Fractured Reservoirs Using Dual-Porosity Flow Diagnostics
Authors: Gutierrez-Sosa Lesly , Geiger Sebastian , Doster Florian
Published: October 2021

Accounting for poro-mechanical effects in full-field reservoir simulation studies and uncertainty quantification workflows is still limited, mainly because of their high computational cost. We introduce a new approach that couples hydrodynamics and poro-mechanics with dual-porosity flow diagnostics to analyse how poro-mechanics could impact reservoir dynamics in naturally fractured reservoirs without significantly increasing computational overhead.

Our new poro-mechanical informed dual-porosity flow diagnostics account for steady-state and singlephase flow conditions in the fractured medium while the fracture-matrix fluid exchange is approximated using a physics-based transfer rate constant which models two-phase flow using an analytical solution for spontaneous imbibition or gravity drainage. The deformation of the system is described by the dualporosity poro-elastic theory, which is based on mixture theory and micromechanics to compute the effective stresses and strains of the rock matrix and fractures. The solutions to the fluid flow and rock deformation equations are coupled sequentially. The governing equations for fluid flow are discretised using a finite volume method with two-point flux-approximation while the governing equations for poro- mechanics are discretised using the virtual element method. The solution of the coupled system considers stress-dependent permeabilities for fractures and matrix. Our framework is implemented in the open source MATLAB Reservoir Simulation Toolbox (MRST).

We present a case study using a fractured carbonate reservoir analogue to illustrate the integration of poro-mechanics within the dual-porosity flow diagnostics framework. The extended flow diagnostics calculations enable us to quickly screen how the dynamics in fractured reservoirs (e.g. reservoir connectivity, sweep efficiency, fracture-matrix transfer rates) are affected by the complex interactions between poro-mechanics and fluid flow where changes in pore pressure and effective stress modify petrophysical properties and hence impact reservoir dynamics.

Due to the steady-state nature of the calculations and the effective coupling strategy, these calculations do not incur significant computational overheads. They hence provide an efficient complement to traditional reservoir simulation and uncertainty quantification workflows as they enable us to assess a broader range of reservoir uncertainties (e.g. geological, petrophysical and hydro-mechanical uncertainties). The capability of studying a much broader range of uncertainties allows the comparison and ranking from a large ensemble of reservoir models and select individual candidates for more detailed full-physics reservoir simulation studies without compromising on assessing the range of uncertainties inherent to fractured reservoirs.
Streamline Tracing and Applications in Dual Porosity Dual Permeability Models
Authors: Onishi Tsubasa , Chen Hongquan , Xie Jiang , Tanaka Shusei , Kam Dongjae , Wang Zhiming , Wen Xian-Huan , Datta-Gupta Akhil
Published: October 2021

Streamline-based methods have proven to be effective for various subsurface flow and transport modeling problems. However, the applications are limited in dual-porosity and dual-permeability (DPDK) system due to the difficulty in describing interactions between matrix and fracture during streamline tracing. In this work, we present a robust streamline tracing algorithm for DPDK models and apply the new algorithm to rate allocation optimization in a waterflood reservoir.

In the proposed method, streamlines are traced in both fracture and matrix domains. The inter-fluxes between fracture and matrix are described by switching streamlines from one domain to another using a probability computed based on the inter-fluxes. The approach is fundamentally similar to the existing streamline tracing technique and can be utilized in streamline-assisted applications, such as flow diagnostics, history matching, and production optimization.

The proposed method is benchmarked with a finite-volume based approach where grid-based time-of-flight was obtained by solving the stationary transport equation. We first validated our method using simple examples. Visual time-of-flight comparisons as well as tracer concentration and allocation factors at wells show good agreement. Next, we applied the proposed method to field scale models to demonstrate the robustness. The results show that our method offers reduced numerical artifacts and better represents reservoir heterogeneity and well connectivity with sub-grid resolutions. The proposed method is then used for rate allocation optimization in DPDK models. A streamline-based gradient free algorithm is used to optimize net present value by adjusting both injection and production well rates under operational constraints. The results show that the optimized schedule offers significant improvement in recovery factor, net present value, and sweep efficiency compared to the base scenario using equal rate injection and production. The optimization algorithm is computationally efficient as it requires only a few forward reservoir simulations.
Physics-Aware Deep-Learning-Based Proxy Reservoir Simulation Model Equipped with State and Well Output Prediction
Authors: J. R. Coutinho Emilio , J. Dall'Aqua Marcelo , Gildin Eduardo
Published: October 2021

Physics-aware machine learning (ML) techniques have been used to endow data-driven proxy models with features closely related to the ones encountered in nature. Examples span from material balance and conservation laws. Physics-based and data-driven reduced-order models or a combination thereof (hybrid-based models) can lead to fast, reliable, and interpretable simulations used in many reservoir management workflows. We built on a recently developed deep-learning-based reduced-order modeling framework by adding a new step related to information of the input-output behavior (e.g., well rates) of the reservoir and not only the states (e.g., pressure and saturation) matching. A Combination of data-driven model reduction strategies and machine learning (deep- neural networks – NN) will be used here to achieve state and input-output matching simultaneously. In Jin, Liu and Durlofsky (2020), the authors use a NN architecture where it is possible to predict the state variables evolution after training an autoencoder coupled with a control system approach (Embed to Control - E2C) and adding some physical components (Loss functions) to the neural network training procedure. In this paper, we extend this idea by adding the simulation model output, e.g., well bottom-hole pressure and well flowrates, as data to be used in the training procedure. Additionally, we added a new neural network to the E2C transition model to handle the connections between state variables and model outputs. By doing this, it is possible to estimate the evolution in time of both the state variables as well as the output variables simultaneously. The method proposed provides a fast and reliable proxy for the simulation output, which can be applied to a well-control optimization problem. Such a non-intrusive method, like data-driven models, does not need to have access to reservoir simulation internal structure. So it can be easily applied to commercial reservoir simulations. We view this as an analogous step to system identification whereby mappings related to state dynamics, inputs (controls), and measurements (output) are obtained. The proposed method is applied to an oil-water model with heterogeneous permeability, 4 injectors, and 5 producer wells. We used 300 sampled well control sets to train the autoencoder and another set to validate the obtained autoencoder parameters.
The Mixed Virtual Element Method for Grids with Curved Interfaces in Single-Phase Flow Problems
Authors: Dassi Franco , Fumagalli Alessio , Losapio Davide , Scialò Stefano , Scotti Anna , Vacca Giuseppe
Published: October 2021

In many applications the accurate representation of the computational domain is a key factor to obtain reliable and effective numerical solutions. Curved interfaces, which might be internal, related to physical data, or portions of the physical boundary, are often met in real applications. However, they are often approximated leading to a geometrical error that might become dominant and deteriorate the quality of the results. Underground problems often involve the motion of fluids where the fundamental governing equation is the Darcy law. High quality velocity fields are of paramount importance for the successful subsequent coupling with other physical phenomena such as transport. The virtual element method, as solution scheme, is known to be applicable in problems whose discretizations requires cells of general shape, and the mixed formulation is here preferred to obtain accurate velocity fields. To overcome the issues associated to the complex geometries and, at the same time, retaining the quality of the solutions, we present here the virtual element method to solve the Darcy problem, in mixed form, in presence of curved interfaces in two and three dimensions. The numerical scheme is presented in detail explaining the discrete setting with a focus on the treatment of curved interfaces. Examples, inspired from industrial applications, are presented showing the validity of the proposed approach.
Strategies to Enhance the Performance of Gaussian Mixture Model Fitting for Uncertainty Quantification by Conditioning to Production Data
Authors: Gao Guohua , Vink Jeroen , Saaf Fredrik , Wells Terence
Published: October 2021

When formulating history matching within the Bayesian framework, we may quantify the uncertainty of model parameters and production forecasts using conditional realizations sampled from the posterior probability density function (PDF). It is quite challenging to sample such a posterior PDF. Some methods e.g., Markov chain Monte Carlo (MCMC), are very expensive (e.g., MCMC) while others are cheaper but may generate biased samples. In this paper, we propose an unconstrained Gaussian Mixture Model (GMM) fitting method to approximate the posterior PDF and investigate new strategies to further enhance its performance.

To reduce the CPU time of handling bound constraints, we reformulate the GMM fitting formulation such that an unconstrained optimization algorithm can be applied to find the optimal solution of unknown GMM parameters. To obtain a sufficiently accurate GMM approximation with the lowest number of Gaussian components, we generate random initial guesses, remove components with very small or very large mixture weights after each GMM fitting iteration and prevent their reappearance using a dedicated filter. To prevent overfitting, we only add a new Gaussian component if the quality of the GMM approximation on a (large) set of blind-test data sufficiently improves.

The unconstrained GMM fitting method with the new strategies proposed in this paper is validated using nonlinear toy problems and then applied to a synthetic history matching example. It can construct a GMM approximation of the posterior PDF that is comparable to the MCMC method, and it is significantly more efficient than the constrained GMM fitting formulation, e.g., reducing the CPU time by a factor of 800 to 7300 for problems we tested, which makes it quite attractive for large scale history matching problems.
A GPU-Accelerated Linear Solver for Massively Parallel Underground Simulations
Authors: Isotton Giovanni , Janna Carlo , Spiezia Nicoló , Tosatto Omar , Bernaschi Massimo , Cominelli Alberto , Mantica Stefano , Monaco Silvia , Scrofani Giovanni
Published: October 2021

Modern engineering applications require the solution of linear systems of millions or even billions of equations. The solution of the linear system takes most of the simulation for large scale simulations, and represent the bottleneck in developing scientific and technical software. Usually, preconditioned iterative solvers are preferred because of their low memory requirements and they can have a high level of parallelism. Approximate inverses have been proven to be robust and effective preconditioners in several contexts. In this communication, we present an adaptive Factorized Sparse Approximate Inverse (FSAI) preconditioner with a very high level of parallelism in both set-up and application. Its inherent parallelism makes FSAI an ideal candidate for a GPU-accelerated implementation, even if taking advantage of this hardware is not a trivial task, especially in the set-up stage. An extensive numerical experimentation has been performed on industrial underground applications. It is shown that the proposed approach outperforms more traditional preconditioners in challenging underground simulation, greatly reducing time-to-solution.
Optimal water allocation based on agricultural and environmental water value
Authors: Hatamkhani Amir , Moridi Ali
Published: October 2021

Despite the significant role of wetlands in maintaining a healthy ecosystem and providing various ecosystem services, they are under threat due to human activities and agriculture use. The fact that the economic value of ecosystem services is not considered in hydro-economic models and integrated water resources management is a key issue that affects the ecosystem and its degradation. the economic value of ecosystem services provides a quantitative and important basis for the reasonable management of water resources. Given that supplying the agriculture and environmental demands conflict with each other, achieving a balance between these goals is very important. So, in this study, a simulation-optimization (WEAP-PSO) approach is employed for optimal planning at the basin and designing environmental flow based on wetland ecosystem services. The objective function of the problem is considered to be the total economic value of the river, which includes the economic value of the agricultural sector and the economic value of the wetland ecosystem services. The decision variables of the problem are considered as, the cultivation area of agricultural units and environmental flow of Kani Barazan wetland. The results show that considering these two objectives together, in addition to sustainable development, causes the highest economic efficiency in the basin.
ARBic: An All-Round Biclustering Algorithm for Analyzing Gene Expression Data
Authors: Liu Xiangyu , Su Zhengchang , Li Guojun
Published: October 2021

Background: Identifying significant biclusters of genes with specific expression patterns is an effective approach to reveal functionally correlated genes in gene expression data. However, existing algorithms are limited to finding either broad or narrow biclusters but both due to failure of balancing between effectiveness and efficiency. Methods: We developed a new algorithm ARBic which can accurately identify any meaningful biclusters of shape no matter broad or narrow in a large scale gene expression data matrix, even when the values in the biclusters to be identified have the same distribution as that the background data has. ARBic is developed by integrating column-based and row-based strategies into biclustering procedure. The column-based strategy borrowed from ReBic, a recently published biclustering tool, prefers to narrow bicluters. The row-based strategy newly designed in this article by repeatedly finding a longest path in a specific directed graph prefers to broader ones. Result and Conclusion: When tested and compared to other seven salient biclustering algorithms on simulated datasets, ARBic achieved recovery, relevance and f1-scores 29% higher than the second best algorithm. Furthermore, ARBic substantially outperforms all of them on real datasets and robusts to noises, shapes of biclusters and types of datasets.Code: https://github.com/holyzews/ARBicData: https://doi.org/10.5281/zenodo.5121018
Discriminators of Pseudoprogression and True Progression in High-Grade Gliomas: A Systematic Review and Meta-Analysis
Authors: Taylor Christopher Stephen , Ekert Justyna O. , Sefcikova Viktoria , Fersht Naomi , Samandouras George
Published: October 2021

BackgroundHigh-grade gliomas remain the most common primary brain tumour with limited treatments options and early recurrence rates following adjuvant treatments. However, differentiating true tumour progression (TTP) from treatment-related effects or pseudoprogression (PsP), may critically influence subsequent management options. Structural MRI is routinely employed to evaluate treatment responses, but misdiagnosis of TTP or PsP may lead to continuation of ineffective or premature cessation of effective treatments, respectively. MethodsA systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) method. The entirety of the Embase and MEDLINE databases were searched for methods differentiating PsP and TTP, and studies were selected using pre-specified eligibility criteria. The sensitivity and specificity of included studies were summarised in a forest plot. Three of the identified methods were assessed in a separate subgroup meta-analysis.ResultsTwenty-six studies assessing seven distinct neuroimaging methods in 1145 patients were included in the systematic review. 18F-fluoroethyltyrosine PET (FET PET) and amide proton transfer-weighted MRI (APTw-MRI) showed high diagnostic accuracy, but results were based on single low-powered studies. The highest performing methods in the subgroup analysis were DWI (AUC = 0.95 [0.92 – 0.96]) and DSC-pMRI (AUC = 0.94 [0.91 – 0.95]), compared to DCE-pMRI (AUC = 0.90 [0.87 – 0.93]).ConclusionsBoth DWI and DSC-pMRI performed with high sensitivity and specificity for differentiating PsP from TTP. Considering the technical parameters and feasibility of each identified method, DSC-pMRI was found to be the most promising technique.
Biweekly Oxaliplatin Plus S1 (SOX) As First Line Therapy For Advanced Or Metastatic Gastric Or Gastroesophageal Junction (G/GEJ) Caner In Chinese Elderly Patients: An Open-Label, Single-Arm, Phase 2 Study.
Authors: Jiang Zhichao , Zhou Aiping , Sun Yongkun , Zhang Wen
Published: October 2021

Background: SOX (oxaliplatin and S1 every 3 weeks) is one of the most common used first line chemotherapy for advanced or metastatic G/GEJ cancer in Asia, but with significant hematological and neurological toxicity. In China, the majority of gastric cancer patients are the middle-aged and elderly with dissatisfactory tolerance to 3-weekly chemotherapy. Therefore, we aimed to assess efficacy and safety of biweekly SOX as first line treatment in patients 60 years old or older with advanced G/GEJ cancer in a single arm phase 2 study. Methods: Oxaliplatin was administered intravenously on day 1 at 85 mg/m2. S-1 was given at 80, 100, 120 mg/day depending on body surface area of <1.25 m2, 1.25 to <1.5 m2, or ≥1.5 m2 two times daily on days 1-10, every 2 weeks. Eligible patients were aged 60 years old or older with histological or cytological diagnosis of advanced G/GEJ adenocarcinoma, had measurable disease according to the RECIST v 1.1 without previous treatment. The primary endpoint was objective response rate (ORR), and the secondary endpoints included progression free survival (PFS), overall survival (OS), disease control rate (DCR), duration of response (DOR) and safety. Results: Between May 2016 and Sep 2018, 42 patients were enrolled. Median follow-up time was 43.6 months. ORR and DCR were 52.4% and 85.7%, respectively. Median PFS was 4.6 months (95%CI 2.486-6.714). Median OS was 11.1 months (95%CI 8.001-14.199). The most common treatment-related adverse events (TRAEs) of any grade were thrombocytopenia (59.5%), neutropenia (57.1%), appetite loss (57.1%) and nausea (54.8%). Only two patients respectively suffered from grade 3 treatment-related neutropenia (1 patient, [2.4%]) and diarrhea (1 patient, [2.4%]). No other grade 3 or worse TRAEs occurred. Conclusions: First line biweekly SOX showed promising PFS and OS with a remarkable tolerance in advanced G/GEJ cancer patients 60 years old or older preliminary worth further evaluation.Trial registration: ClinicalTrials.gov ID: NCT04694404 (5/1/2021). This study was approved by the Ethical Committee of National Cancer Center/ National Clinical Research Center for Cancer/ Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, (17-048/1303).
Computed Tomography Characterization of Emphysema in Combined Pulmonary Fibrosis and Emphysema (CPFE) and its Correlation with Lung Cancer with Comparison to Chronic Obstructive Pulmanory Disease (COPD)
Authors: Qiu Jianxing , Nie Ligong , Xiong Yan
Published: October 2021

Purpose: To investigate imaging features of emphysema on high-resolution computed tomography (HRCT) in combined pulmonary fibrosis and emphysema (CPFE) and its correlation with lung cancer, with comparison to chronic obstructive pulmonary disease (COPD). Methods: 160 consecutive patients (80 CPFE and 80 COPD ) were analyzed retrospectively. The HRCT imaging features of the two groups were compared, and the correlation between factors underlying CPFE and the occurrence of lung cancer was analyzed. Results: We found paraseptal emphysema to be the more common form of emphysema in CPFE (38.75%), with an incidence statistically higher than that of COPD (χ²=14.462, p=0.001). The extent of emphysema in each lung lobe in the CPFE group was statistically less than that in the COPD group (p<0.01). Homogeneous emphysema was common in both the CPFE (73.8%) and COPD groups (52.5%), and it showed a higher incidence in CPEF group (χ²=7.760, p=0.004). Homogeneous emphysema also showed significantly high correlation to lung cancer (χ²=9.298, p=0.004). The incidence of lung cancer in the CPFE group (20%) was higher than that in the COPD group (8.8%) (χ²=4.113, p=0.035). There was a linear relationship between the incidence of lung cancer and the degree of pulmonary interstitial fibrosis and years of smoking in CPFE patients (χ²=6.679, p=0.01* ,b=0.148). Conclusion: Different emphysema features showed between CPFE and COPD, and CPFE showed higher incidence of lung cancer. Homogenous emphysema, severity of damage caused by interstitial fibrosis and the number of smoking years have high relationship with incidence of lung cancer in CPFE.