1,720,979 research outputs found
컴퓨터를 활용한 금속-유기 구조체 복합물질 디자인
No full text학위논문(박사) - 한국과학기술원 : 생명화학공학과, 2020.2,[iv, 86 p. :]Metal-organic frameworks (MOFs) which consist of metal complex and organic ligand with coordination bonding are crystalline nanoporous materials and more than 80,000 MOFs have been synthesized with diverse components. MOFs can be applied to adsorbent, catalyst, sensor, gas storage and separation by virtue of high surface area and high tunability. Composite metal-organic frameworks which consist of MOF and other materials and complement each other have been actively studied for the last 10 years to apply MOFs to realistic applications. However, the number of MOF-MOF composite materials was limited despite the conceivable combinations of MOF-MOF were enormously large. Therefore, it is important to investigate the unexplored material space of MOF-MOF composite, design and synthesize the new composite MOF-MOF. For efficient discovery of new composite materials, a joint computational/experimental approach where computational screening is conducted to find more possible candidiates before experimentalists try to synthesize new materials is necessary. In this thesis, computational design of (1) hetero-interpenetrated MOFs and (2) MOF@MOF or Core-Shell MOF composite were conducted using large MOF database and algorithm to analyze the structural information and identify whether MOF composite can be formed using two different MOF structures. Furthermore, for the real synthesis of polymorphic MOFs which have good properties but are difficult to be directly synthesized, MOF assembly algorithm using top-down approach and algorithm for MOF@MOF screening were combined to obtain the pairs of polymorphic MOF and the seed MOF which can be used to synthesize the polymorphic MOF. As a results, the new types of composite MOFs were computationally designed and the predicted core shell MOFs were successfully synthesized in experiments. The results demonstrate that computational method can be useful tool to accelerate the development of new composite MOF.한국과학기술원 :생명화학공학과
상용 GPU 에서 안전한 온칩 실행환경 구축을 위한 연구
No full text학위논문(박사) - 한국과학기술원 : 전산학부, 2020.2,[iv, 58 p. :]In the last decade, the dedicated graphics processing unit (GPU) has emerged as an architecture for high-performance computing workloads. Recently, researchers have also focused on the isolation property of a dedicated GPU and suggested GPU-based secure computing environments with several promising applications. Through implementations and security analysis, they have claimed that a dedicated GPU can be leveraged as a secure processor in the presence of a kernel-privileged attacker. However, despite the security analysis conducted by the prior studies, it has been unclear whether a dedicated GPU can support secure execution environment against a kernel-privileged attacker. In this dissertation, we first investigate the security of dedicated GPUs through comprehensive studies on context information for GPU kernel execution. We show that a kernel-privileged attacker can manipulate the GPU contexts to redirect memory accesses or execute arbitrary GPU codes on the running GPU kernel. Furthermore, we introduce the installation method of stealthy rootkit hidden inside GPU kernel execution through GPU context manipulation.
Based on our security analysis, we propose a new secure isolated on-chip execution model for the dedicated GPU and a novel defense mechanism supporting the security of the on-chip execution. Our solution operates on Nvidia commodity GPUs without any modification of the hardware or GPU driver and without an additional hardware-abstraction layer. With comprehensive evaluation, we assure that the proposed solutions effectively isolate sensitive information in on-chip storages and defend against known attack vectors from a privileged attacker, supporting that the commodity GPUs can be leveraged as a secure processor.한국과학기술원 :전산학부
Synthesis of a solid solution for the lithium ion conductor, Li10+δGe1+δP2-δS12 : its conduction mechanism and application to all-solid-state batteries
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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