Traditional Inversion Research Articles

Estimating emissions of methane consistent with atmospheric measurements of methane and δ13C of methane

Abstract. We have constructed an atmospheric inversion framework based on TM5-4DVAR to jointly assimilate measurements of methane and δ13C of methane in order to estimate source-specific methane emissions. Here we present global emission estimates from this framework for the period 1999–2016. We assimilate a newly constructed, multi-agency database of CH4 and δ13C measurements. We find that traditional CH4-only atmospheric inversions are unlikely to estimate emissions consistent with atmospheric δ13C data, and assimilating δ13C data is necessary to derive emissions consistent with both measurements. Our framework attributes ca. 85 % of the post-2007 growth in atmospheric methane to microbial sources, with about half of that coming from the tropics between 23.5∘ N and 23.5∘ S. This contradicts the attribution of the recent growth in the methane budget of the Global Carbon Project (GCP). We find that the GCP attribution is only consistent with our top-down estimate in the absence of δ13C data. We find that at global and continental scales, δ13C data can separate microbial from fossil methane emissions much better than CH4 data alone, and at smaller scales this ability is limited by the current δ13C measurement coverage. Finally, we find that the largest uncertainty in using δ13C data to separate different methane source types comes from our knowledge of atmospheric chemistry, specifically the distribution of tropospheric chlorine and the isotopic discrimination of the methane sink.

鏡裏花間———試論《花間集》的鏡書寫

LANGUAGE NOTE | Document text in Chinese; abstract also in English.
 本文以先秦至唐五代銅鏡發展爲依據，考述《花間集》中鈿鏡、鸞鏡、有柄鏡、菱花鏡，以及鏡匣、鏡奩、鏡臺等週邊器物，對於向來不易確解的詞句提出具實物背景的解讀，從而使詞作脈絡、詞中場景獲得更爲清晰的梳理與呈現。以此爲基礎，透過鏡的文化與文學意涵，對照詩歌傳統中的鏡書寫，亦得以凸顯《花間集》中與鏡相關詞作的特殊表現與深層内藴。異於詩人的各言其志與寫實風格，對鏡感傷壯志消磨、紅顔易老，或描寫眼前如鏡晶瑩的水月風光，詞人隱身詞境之外，以如鏡之照影的手法，如“實”映現鏡花水月般未必真實存在的人事物，比如對鏡理妝或掩鏡無語的閨閣女子、虚擬遠隔的樂園與歷史場景等，而於精致如鏡的詞境中藴含深情妙理，在冷落中猶自好修、在困境中夢想飛越，以及樂園的探尋、殷鑑的徒勞、愛與美的救贖等，可謂於幻境中披露真實，於轉瞬消逝的時空中鏤刻永恒。
 This paper studies a variety of Chinese bronze mirrors mentioned in the Huajian ji (Collection from Among the Flowers). These mirrors are of different designs, such as mirrors inlaid with mother-of-pearl, mirrors with carved legendary birds, mirrors with handles, mirrors with carved petal-shaped octofoils. The paper also discusses relevant peripheral items including mirror cases, mirror chests, and mirror stands. It will start with the development and history of bronze mirrors from the pre-Qin to Tang and Five dynasties. In this way, we can interpret those words that have always been vague and ambiguous by utilizing the background knowledge about the physical objects mentioned above. As a result, the backgrounds and contexts of the relevant works in the Huajian ji can be clearly sorted and presented. Next, by comparing the cultural and literary meaning of mirrors with the writing of mirrors in the poetic tradition, the special expression and inner connotation of Ci-poems related to mirrors in the Huajian ji can be highlighted. In traditional poetry, poets mostly describe a real situation, such as unfulfilled ambition and weakening willpower; sentimental feelings when facing a mirror and being saddened by diminishing beauty and youth; and the depiction of the mirage of untouchable flowers and moons reflected on the mirror. On the other hand, Ci poets of the Huajian ji use the method of mirroring to represent interactions involving mirrors to reflect people, objects and scenes that may not necessarily exist. They include, for example: a lady in the boudoir making up in front of the mirror or covering her mirror speechlessly; an illusory paradise or historical scenes; expressing their will to overcome obstacles, to cultivate themselves, to search for paradise and salvation of love and beauty; and also the disappointment of failing to learn from history. In conclusion, such exquisite and delicate mirror-like illusions allow us to visualize the Ci poets’ affection, beliefs, and the truth they wished to deliver.

Facies-based Bayesian simultaneous inversion technology and its application: A case study of the north section of No.5 fault zone in Shunbei area, Tarim Basin, China

The fault-karst carbonate reservoir in the Shunbei area of the Tarim Basin is controlled by deep strike-slip faults and forms a fault-karst system. The reservoir space primarily includes holes and fractures, and its strong anisotropism aggravates the complexity of the reservoir seismic response characteristics. High-quality reservoirs in the fault-karst body in this area have different burial depths, which is not conducive to the establishment of low-frequency models in traditional inversion. Facies-based Bayesian simultaneous inversion technology combines Bayesian classification with pre-stack simultaneous inversion, divides different facies based on multi-elastic parameters such as P-wave and S-wave velocity and density, and conducts an in-depth trend analysis for each phase to establish the initial model. Compared with traditional inversion technology, this technology not only improves the inversion accuracy but also increases the stability of the density inversion. Taking the carbonate fault-karst body in the northern section of the No.5 fault zone in the Shunbei area as the research object, combined with the actual production situation, two facies, fractured-cavity limestone, and tight limestone, were divided by elastic parameters and then subjected to depth trend analysis and inversion. Through the single fracture-cavity equivalent model test and practical application analysis, the density data obtained by the Facies based Bayesian simultaneous inversion were highly consistent with the reservoirs drilled by Wells W3 and W3C in the northern section of the No.5 fault zone, which verifies the applicability and reliability of the inversion technique in the study area and the reliability of the results.

Enslaved Ecopoetics:

Scholars, such as Kimberly Ruffin and Katherine Lynes, reconsider American environmental poetry that excludes African American ecopoetic traditions of the antebellum period. According to Ruffin, in order to reconstruct and enhance our sense of ecopoetry, we must reevaluate the black tradition of nature poetry, exemplifying the contemporary approaches to slavery in the USA and elsewhere. Likewise, Lyne’s “reclamation ecopoetics” attends to the history of dangers, despite centuries of methodical and organized exploitation, that human groups bring to the black human subjects as well as to non-human nature. Building on this scholarship, I focus on the nature poems of George Moses Horton (1797- 1883), the life-long enslaved poet, that highlight the inseparable unity of nature and humans. Horton’s poetry deployed nature to prove both the humanity and the intellectuality of the enslaved. My study traces a history of American enslaved ecopoetics that requires us to think of the enslaved human subjects as individuals whose nature poetry hinges on the dangers of subjection and exploitation of chattel slavery. My essay resituates Horton, the black bard of North Carolina, in the nineteenth-century American paradigm, analyzing his poetry and his racial subjugation from an ecocritical perspective.

The Beautiful Guantánamo

In "The Beautiful Guantánamo," Mansoor Adayfi, who was imprisoned for fourteen years there without charge, refutes the narratives and images carefully curated by the US government about its captives. Adayfi describes how men and boys speaking eighteen different languages and representing fifty nationalities shared their different cultures with one another and, through communal experiences, generated their own distinctive Guantánamo culture from 2002 to 2010. Beginning with the fear, estrangement, and abuse prisoners experienced upon their arrival, the author details how forming a common language and traditions in greetings, poetry, song, and dance created a brotherhood among those held and helped them to survive. From learning how to greet one another in their own languages to devising classes and cultural competitions, the prisoners forged a unique set of cultural practices to sustain themselves. The essay demonstrates how Guantánamo culture evolved as a mode of communication, self-expression, resistance, and survival and, in the process, as the author writes, ensured prisoners held on to the humanity that the prison sought to destroy.

From the Heights of the Atlas: A Panorama of Traditional Poetry in Tamazight

AbstractTraditional oral poetry in Takbaylit, Tachelhit, Central Moroccan Tamazight, and Tarafit dialects has been the subject of numerous studies ranging from ethnographic to linguistic. Rather than duplicate what is already widely available, the following brings together comments on a number of representative poems from across the Maghreb to give the reader an idea of the variety of types, styles, and themes of Tamazight poetic tradition. The selections, which are translated into English here for the first time, range from the moving devotional poem in Tachelhit “Like the Beads of a Rosary” to the beautiful love poem in Takbaylit “To Whom Should I Complain.” Among the poets whose works are included are Mririda n'Ait Attik (Tachelhit), Al Hadj Ammar ou al Hadj (Takbaylit), and Taougrat Oult Aissa (Central Moroccan Tamazigt).

Ecocriticism and the Pastoral Tradition in Romantic Poetry

Ecocriticism, an interdisciplinary approach that examines the relationship between literature and the physical environment, has gained prominence in recent decades. This paper explores the interplay between ecocriticism and the pastoral tradition in Romantic poetry, focusing on the works of William Wordsworth, Samuel Taylor Coleridge, and John Clare. By examining the poets' depictions of nature, this study highlights how Romantic poetry reflects and critiques contemporary environmental concerns. The analysis underscores the relevance of Romantic pastoral poetry to modern ecological discourse and its potential to inspire environmental consciousness.

Updates on feminizing genital affirmation surgery (vaginoplasty) techniques.

Vaginoplasty is a gender affirming surgery performed for transgender women who desire feminizing genital reconstruction. Over the last decade, access to surgical care has improved for patients, and vaginoplasty has been increasingly performed. Several vaginoplasty techniques exist, many of which are modifications of the traditional penile inversion vaginoplasty. In this paper, we review the penile inversion vaginoplasty, the intestinal segment vaginoplasty and the peritoneal flap vaginoplasty. An overview of the techniques employed to perform these procedures is provided, as well as an update on their published outcomes and complications.

Iterative Objects: Hauntings of Identity in Poetic Form

Abstract Channeling Gertrude Stein’s assertion from her lecture “Portraits and Repetition” that there is no such thing as repetition because both language and other entities that compose the world are continuously undergoing change, this essay explores the question of iteration or recursion in two recent critical books, Brian Kim Stefans’s Word Toys: Poetry and Technics (2017) and Jacob Edmond’s Make it the Same: Poetry in the Age of Global Media (2019). Stefans develops a critical practice that considers poems to be autonomous, dynamic entities, akin to machines or living organisms, thus connecting to longstanding traditions in twentieth-century poetry, which have imagined words as objects that populate the open field of the poem. However, much as Stein suggests, such linguistic objects are not self-same or stable. This opens the question of the role of iteration with a difference in the constitution of such entities, and in the context of Edmond’s book Make It the Same this question is extended to poetic techniques, such as copying, in their variously mediated forms, ranging from the use of a tape recorder to digital media.[L]iving entities, which for Stein as for Stefans, can be defined as forms of subjectivity—as poems, roses or frogs—are not self-same and are, instead, iteratively created in each recursion or repetition.

A 3-D Full Convolution Electromagnetic Reconstruction Neural Network (3-D FCERNN) for Fast Super-Resolution Electromagnetic Inversion of Human Brain.

Three-dimensional (3-D) super-resolution microwave imaging of human brain is a typical electromagnetic (EM) inverse scattering problem with high contrast. It is a challenge for the traditional schemes based on deterministic or stochastic inversion methods to obtain high contrast and high resolution, and they require huge computational time. In this work, a dual-module 3-D EM inversion scheme based on deep neural network is proposed. The proposed scheme can solve the inverse scattering problems with high contrast and super-resolution in real time and reduce a huge computational cost. In the EM inversion module, a 3-D full convolution EM reconstruction neural network (3-D FCERNN) is proposed to nonlinearly map the measured scattered field to a preliminary image of 3-D electrical parameter distribution of the human brain. The proposed 3-D FCERNN is completely composed of convolution layers, which can greatly save training cost and improve model generalization compared with fully connected networks. Then, the image enhancement module employs a U-Net to further improve the imaging quality from the results of 3-D FCERNN. In addition, a dataset generation strategy based on the human brain features is proposed, which can solve the difficulty of human brain dataset collection and high training cost. The proposed scheme has been confirmed to be effective and accurate in reconstructing the distribution of 3-D super-resolution electrical parameters distribution of human brain through noise-free and noisy examples, while the traditional EM inversion method is difficult to converge in the case of high contrast and strong scatterers. Compared with our previous work, the training of FCERNN is faster and can significantly decrease computational resources.

Die Dorfgeschichte in Zeiten von Globalisierung und Anthropozän

Abstract The recent vogue of village stories comes rather unexpected in a time of ‘globalization’. Starting out from Marcus Twellmann’s seminal study on the history of this genre, the present article discusses some possible reasons for this development. The second part gives an outline of the relation between the village story and the tradition of georgic poetry.

GrowClust3D.jl: A Julia Package for the Relative Relocation of Earthquake Hypocenters Using 3D Velocity Models

Abstract Relative relocation techniques are widely used to improve the resolution of earthquake hypocenter positions. Here, we present GrowClust3D.jl—an open-source software package written in the programming language Julia that builds and improves upon the original GrowClust algorithm, an established relative relocation technique based on cluster analysis instead of a more traditional matrix inversion approach. The adoption of Julia’s modern programming environment allows for greater flexibility in GrowClust3D.jl’s algorithm design and its computational implementation. Notable additions to the GrowClust3D.jl package include (1) several parallel processing options to improve efficiency in uncertainty quantification routines, (2) incorporation of geographic map projections and station elevations during the relocation process, and (3) the ability to use travel-time tables derived from 3D velocity models. We demonstrate the new features of the software package on relocation problems of different scales in Nevada, California, Texas, and New Zealand, where in the latter two cases the use of a 3D velocity model helps resolve structures that remain obscure with earlier versions of GrowClust. We expect that the new GrowClust3D.jl software package will become a valuable public resource for the earthquake science community.

Fast inner-loop control of air-breathing hypersonic vehicles

This paper investigates the inner-loop attitude and velocity control problem for air-breathing hypersonic vehicles subject to practically constrained actuators. Traditional nonlinear dynamic inverse (NDI) is enhanced by an intelligent control allocation (ICA) to realise the low-complexity attitude decoupling. The ICA addresses various characteristics of aerodynamic control surfaces while providing an efficient detecting mechanism for allocation errors. Within the ICA-NDI frame, a finite-time disturbance observer-based terminal sliding mode (FTDO-based TSM) attitude controller regulates Euler angles in the fast manner. This attitude controller employs an improved integral sliding surface containing necessary information from both ICA detection and FTDO estimation, which, therefore, is capable of accommodating constrained control surfaces and rejecting mismatched disturbances. Meanwhile, an adaptive governor adjusts the velocity reference according to the current saturation level of the scramjet fuel-to-air equivalency ratio. The governor is further integrated to a baseline adaptive velocity controller to synthetically handle scramjet input saturations and uncertain factors.

ON TUNAY ÖZER'S POEMS A REVIEW

Bu çalışmada yayımlanmış dört kitabı bulunan Tunay Özer’in bu kitaplarındaki şiirleri yapı, dil ve üslup, ağırlıklı olarak da içerik yönünden incelenmiştir. Bu inceleme ile şiirlerinin ana temaları, yapı, içerik ve üslup yönünden nitelikleri ve gelişim seyri belirlenmeye çalışılmıştır. Şairin hayat serüveni ve şiirlerinin yayımlanma sürecine dair bilgilere yer verilmiş, kullandığı dil ve semboller evreni açısından Türk şiiri geleneği ile kurduğu ilişkiye de değinilmiştir. Şiirlerinin tümünü serbest nazımla yazan şairin, çoğunlukla “hüzün, hatırlamalar ve hasret” üzerine bir içerikle okurlarının karşısına çıktığı belirlenmiş, şiirleri kitaplaştırılmadan önce ve hâlen çeşitli dergilerde yayımlanan şairin şiir serüveninde ilk kitabından son kitabına doğru içerik ve üslup yönünde sürekli bir gelişme olduğu gözlenmiştir.

Study on Inversion Algorithm of NMR T2 Spectrum

Nuclear magnetic resonance (NMR) logging technology is a kind of technology developed gradually in recent decades, which has great significance for the development of logging technology. Nuclear magnetic resonance logging technology compared to traditional logging technology, not only has the ideal signal - hydrogen nuclei, and the exploration of the original signal is not affected by the influence of the rock skeleton, is the only provides information that is unrelated to formation rock porosity, can better provide the formation permeability, movable fluid, oil and gas content, such as information, It is a kind of logging method suitable for low porosity and low permeability and complex special lithology, and overcomes the defects of traditional logging methods .With the development of NMR theory, NMR has been applied to the analysis of well logging data. The original NMR logging data are the spin-echo string observed by the spin echo string, and its amplitude decays with time. The T2 spectrum can be inversely calculated from the measured logging data, and then the T2 spectrum can be further solved to obtain key data such as permeability and porosity. In this paper, a simulated T2 spectrum is constructed by forward modeling, and the inversion is carried out under different SNR. On this basis, the specific relationship between the optimal number of singular values retained and the change of SNR is summarized, and an improved singular value decomposition algorithm is proposed. Inverse problem can be converted to nonlinear fitting optimization problems with nonnegative constraints, linear truncation algorithm on calculation precision has increased significantly, compared with the traditional singular value decomposition inversion algorithm, a new algorithm of signal-to-noise ratio on the solution of smaller and has better stability, and through the improvement of nonnegative constraint processing structure was more rapid inversion iteration algorithm.

Stochastic inversion of tracer test data with seismicity constraint for permeability imaging in enhanced geothermal reservoirs

Inference of permeability distribution in an enhanced geothermal reservoir is crucial for the sustainable management of geothermal energy. However, interpreting the uneven permeability distribution in a deep geothermal reservoir remains a challenging task because in practice there often are merely one or two wells available for hydrogeophysical tests. Considering that the induced seismicity data are widely captured during reservoir stimulation in enhanced geothermal systems, a framework of tracer test data inversion with the constraint of induced seismic data is developed for permeability imaging. Hydraulic diffusivity, representing the prior estimation of permeability, is inferred from the occurrence time of seismic events. This is followed by the determination of a petrophysical model, which relates hydraulic diffusivity to permeability, by tracer test data inversion based on the Markov chain Monte Carlo algorithm. Implementation of the seismicity-constraint tracer data inversion algorithm in the Habanero enhanced geothermal system, Australia, demonstrates that our inversion model allows uneven permeability estimation at field scale in shorter burn-in period and lower uncertainty than the traditional inversion model without seismicity constraint. Using the estimated permeability in the hydrothermal model enables accurate prediction of thermal performance in a 150 day trial-production test. Results indicate that this algorithm can reliably characterize the spatial distribution of permeability in deep enhanced reservoirs, based on the tracer test via doublet wells.

Variational encoder geostatistical analysis (VEGAS) with an application to large scale riverine bathymetry

Estimation of riverbed profiles, also known as bathymetry, plays a vital role in many applications, such as safe and efficient inland navigation, prediction of bank erosion, land subsidence, and flood risk management. The high cost and complex logistics of direct bathymetry surveys, i.e, depth imaging, have encouraged the use of indirect measurements such as surface flow velocities. However, estimating high-resolution bathymetry from indirect measurements is an inverse problem that can be computationally challenging. Here, we propose a reduced-order model (ROM) based approach that utilizes a variational autoencoder (VAE), a type of deep neural network with a narrow layer in the middle, to compress bathymetry and flow velocity information and accelerate bathymetry inverse problems from flow velocity measurements. In our application, the shallow-water equations (SWE) with appropriate boundary conditions (BCs), e.g., the discharge and/or the free surface elevation, constitute the forward problem, to predict flow velocity. Then, ROMs of the SWEs are constructed on a nonlinear manifold of low dimensionality through a variational encoder and the bathymetry inversion problem is derived on the low-dimensional latent space in a Hierarchical Bayesian setting. The reformulation allows variational inference with a small number (e.g., O(100) of ROM runs and efficient uncertainty quantification. We have tested our inversion approach on a one-mile reach of the Savannah River, GA, USA. Once the neural network is trained (offline stage), the proposed technique can perform the inversion operation orders of magnitude faster than traditional inversion methods that are commonly based on linear projections, such as principal component analysis (PCA), or the principal component geostatistical approach (PCGA). Furthermore, tests show that the algorithm can estimate the bathymetry with good accuracy even with sparse flow velocity measurements.

Frequency-Bessel Transform Based Microtremor Survey Method and Its Engineering Application.

The development and utilization of urban underground space depend heavily on an understanding of urban geological conditions. The microtremor survey method is essential in urban geological surveys due to its quickness, convenience, non-destructiveness, and interference resistance. Since only the fundamental dispersion curves of Rayleigh waves can be obtained by utilizing the spatial autocorrelation method, the inversion results have multiple solutions. To improve the accuracy of the microtremor survey, this study employed the frequency-Bessel transform to extract the fundamental and higher modes of dispersion information of Rayleigh waves from the microtremor data array and verified the effectiveness of this method by synthesizing theoretical microtremor signals. Additionally, taking into account the order identification challenges brought on by mode jumps or missing modes in the dispersion curve, this study processed a multi-mode dispersion curve based on the newly proposed inversion objective function coupled with a genetic algorithm to obtain a shallow surface S-wave velocity structure. Compared to the traditional inversion objective function, the new function presented in this study could address mode misidentification more effectively and improved the accuracy of inversion calculations. Finally, the applicability and dependability of the frequency-Bessel-transform-based microtremor survey method were evaluated in a practical engineering case.

Social Thought in the Works of Poet Vaali

Millions of people all over the world are still listening to Vaali's songs every day. Poet Vaali has carved a niche for himself in the film industry for more than 60 years as a film lyricist. Vaali entered the film industry when Kannadasan was ruling the industry with his songs and became famous for composing songs on par with Kannadasan's songs. He has written a variety of songs such as traditional poetry, new poems, and musical compositions, and made them fly the flag of success. He is also able to deal with social ills and social problems with a view to creating social awareness. The poet Vaali is someone who can use film songs and poetry as a good means of communication. This article explores how he has approached social evils and social woes in his works with his rich vocabulary.

Gravity and magnetic fast inversion method with cross-gradient based on function fitting

SUMMARY The underground density and magnetic susceptibility structure obtained by cross-gradient inversion of gravity and magnetic data can provide an important basis for the evaluation of mineral resource potential. The inversion is realized by discretizing the subsurface into a series of cells and calculating the physical properties of each cell. This restricts the application in the inversion of large-area data because of the large memory usage and low computational efficiency owing to the large solution matrix. We proposed a high-efficiency cross-gradient inversion method of gravity and magnetic data based on function fitting, which uses a parametrized function to fit the physical properties of the central points of a number of cells in certain space based on the assumption that the physical property in each cell is uniform in the inversion. Therefore, the calculation of physical properties is replaced by the calculation of function coefficients. The number of cells that can be fitted by a function is more than the number of function coefficients. Thus, the new method requires less memory and can improve computational efficiency. In addition, with the function fitting method, the gradient terms can be directly obtained by the function coefficients instead of using the traditional central difference or multipoint fitting method, which could further improve the computational efficiency. The effectiveness and high computational efficiency of the proposed method were verified by model tests, and the accuracy of the inversion results was not lower than that of the traditional inversion method. We also proved that the proposed method is suitable for uniform hexahedral and unstructured tetrahedral cells. The real application area is located in eastern China and contains skarn-type magnetite deposits, which are characterized by high density and high magnetic susceptibility. The proposed method was used to obtain subsurface high-resolution density and magnetic susceptibility structures. We obtained the distribution range of mineral resources based on the ratio of density to magnetic susceptibility, which provides an important basis for further exploration. The model tests and real data applications show that the proposed method is more suitable for large-scale precise inversion and has better practicability.