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Improved Ultimate Link without Markers for Projective Transformation
Full text linkIn our previous work, we have proposed a method that links character string having a certain semantic meaning on papers in real world to the digital content in cyberspace, and call it Ultimate Link." Ultimate Link adds additional information to characters by drawing colored circles on top of the characters without changing the shape of the characters. A URL can be generated by connecting additional information of semantically organized character strings from an image taken with a digital device. The conventional Ultimate Link drew markers to normalize the drawn circles (markers for projective transformation), similar to the finder pattern in a QR code. In order to achieve a more realistic application, it is desirable it. We report on an improved Ultimate Link that can handle complex multiple character strings. Specifically, improvements were made to enable extraction of information by identifying character strings with embedded additional information from sheets of paper printed with multiple character strings. As a result of experiments, we confirmed that information could be successfully embedded and extracted for both character strings in the target image."journal articl
Role of Chloride Ions in the Heat Treatment of β-FeOOH(Cl) Catalysts to Enhance the Oxygen Evolution Reaction Activity
Full text linkFe-based catalysts are ideal for the oxygen evolution reaction (OER) owing to their earth abundance. However, most of these catalysts are usable only in an alkaline solution because they dissolve at low pH. Therefore, to be sufficiently versatile for large-scale energy conversion and storage devices, they must maintain high activity over a wide pH range. Cl–-stabilized Fe oxyhydroxide, i.e., hollandite-type β-FeOOH(Cl), nanorods have been reported to function in a (nearly) neutral solution with a relatively high activity, which was further improved by heat treatment at ∼200 °C; however, the mechanism underlying this enhancement was poorly understood because of the complicated transformation of β-FeOOH(Cl) to α-Fe2O3 during heating. Therefore, we investigated the structural changes in heat-treated β-FeOOH(Cl) using synchrotron-based X-ray diffraction measurements in addition to several spectroscopic methods and compositional analyses. Structural and compositional analyses, including Rietveld methods, revealed that β-FeOOH(Cl) underwent an indirect phase transformation via a Cl–-enriched β-FeOOH(Cl) intermediate phase at 200 °C before α-Fe2O3 formed. The Cl/Fe ratio of the intermediate phase (0.19) was almost twice that of the initial phase (0.08); furthermore, operando X-ray absorption spectroscopy clarified that the Cl–-enriched β-FeOOH(Cl) phase was stable during the OER even at a high current density of ∼22 mA cm–2. First-principles calculations using β-FeOOH(Cl) supercell models with Cl/Fe = 0.125 and 0.25 revealed that enrichment with Cl– ions increased Cl– diffusivity along the tunnel direction in hollandite, notably increasing the electrical conductivity and diffusion coefficient. Both of these properties could enhance the OER activity of β-FeOOH(Cl) catalysts, in addition to previously proposed structural strain. This finding suggests a structure–activity relationship that can serve as a guideline for broadening the use of β-FeOOH(Cl) OER catalysts.journal articl
Weyl groups of groupoid C*-algebras
Full text linkIn the theory of C*-algebras, the Weyl groups were defined for the Cuntz algebras and graph algebras by Cuntz and Conti et al. respectively. In this paper, we introduce and investigate the Weyl groups of groupoid C*-algebras as a natural generalization of the existing Weyl groups. Then we analyse several groups of automorphisms on groupoid C*-algebras. Finally, we apply our results to Cuntz algebras, graph algebras and C*-algebras associated with Deaconu–Renault systems.journal articl
Detection of Lung Regions from LDCT Images and 3D Image Registration Using FFD
Full text linkIn recent years, lung cancer is a serious disease worldwide. To overcome the disease, early detection and early treatment of lung cancer are important tasks. In Japan, CT (Computed Tomography) examination is performed in many medical facilities for visual screening. However, there is a problem that huge number of images taken by CT is a burden to the doctor. Therefore, the CAD (Computer Aided Diagnosis) system is in the spotlight to reduce the burden. On the other hand, in CT screening, LDCT (Low Dose Computed Tomography) is desirable considering radiation exposure. However, the LDCT image is characterized by lower image quality at lower dose. Therefore, a CAD that can be applied to LDCT is needed. In this paper, we propose a lung field detection method and a three-dimensional (3D) registration method to generate temporal subtraction images that can be applied to LDCT images. Our method consists of the following steps: detection of lung regions using an active contour model, correction of corresponding slices between images, global matching based on the center of gravity, setting the VOI (volume of interest), and local matching on the VOI. In this paper, we apply our method to LDCT images of 7 cases. In addition, we conducted a comparison experiment with other registration methods. In the proposed method, a decrease of 7.55% in FWHM and 34.4% in sum of histogram of temporal subtraction images compared to the other method, and its usefulness was verified.journal articl
An attempt to realize digital transformation in local governments by utilizing the IT skills of information science students
Full text linkDivision of Business Improvement and Digital Transformation of Iizuka City Hall in Fukuoka Prefecture and students from Faculty of Computer Science and Systems Engineering at Kyushu Institute of Technology collaborated to attempt to use IT to improve various aspects of Iizuka City Hall's operations. First, Division of the Business Improvement and Digital Transformation solicited themes from divisions in Iizuka City Hall, selected around 10 from these and assigned university students to the themes to be solved. The information science students had a range of skill levels. They solved the problems in a variety of ways, including using automated processing, using cloud services, and developing software for tablet devices. While some of these methods have actually been used, there are also cases where they are not. This is thought to be because the system was created without sufficient consideration of how it would be used in the real case.journal articl
Current balancing of parallel-connected silicon carbide (SiC) MOSFET power devices using peak detection via PCB sensors
No full textThe parallelling of power semiconductor devices is essential for desired current ratings and the system is prone to the current unbalancing due to parameter variations. SiC devices with significant variable threshold voltage due to manufacturing yield and temperature distribution have a consequential possibility of dynamic current unbalancing. This paper presents the peak detection-based current balancing of parallel-connected SiC devices to minimize the turn-on and turn-off current unbalancing. PCB current sensors are used for the measurement and feedback of the signal for this peak detection-based current balancing mechanism.journal articl
A Discussion on Periodic Communication Disruption in LEO Satellite Constellations
Full text linkThere are few IP unreachable areas outside the Internet coverage by terrestrial or wired link. Low Earth Orbit (LEO) satellite constellations may cover such IP unreachable areas. Starlink by SpaceX (Space Exploration Technologies Corp.), which is a major LEO satellite constellation service, is reported to disrupt communication at the fixed timing due to handover periodically. It is, however, still unclear how periodic communication breakdowns occur and how they affect traditional transport protocols such as TCP and UDP. This paper confirms the periodic communication breakdowns of Starlink and evaluates how TCP and UDP are affected. We have confirmed that handover surely occurs at the fixed interval of 15 seconds and the fixed timing of 12, 27, 42, and 57 seconds for each minute due to handover. We then observed that handover times ranged from 139 ms to 384 ms, which is longer than previously reported. In addition, Starlink may buffer or retransmit packets somewhere in its network, and some packet losses may be avoided.journal articl
生成AIが事前提出型課題の書類審査に与える影響
Full text link本研究では大学入学者選抜に事前提出型課題に生成AI が利用された場合，その評価にどのような影響が出るかについて調査した。自由度の高い書類では，生成AI を使った場合，基本的には受験生の答案の方が生成AI で作成したものより高得点になる傾向があった。これは生成AI の性能よりもプロンプトに依存するため，生成AI の使用者の理解度が得点に影響するためであると考えた。一方，短い文章の評価では低得点の学生の得点が向上するため，実力が見えにくくなる課題も浮上した。さらに，実際に生成AI を利用しているかどうか問わず，評価者が生成AI を利用しているのではないかという印象を持つと，やや得点が低くなる傾向がみられた。以上のことから今後も事前提出型の文章評価を行う場合は生成AI の影響を考え評価基準の見直す必要があることが示された。This study examined how using generative AI for entrance examinations in universities affects their evaluation. For assignments with high freedom, students’ answers tended to score higher than those generated by AI. This suggests that scores depend more on the prompt than the AI’s performance, meaning the user’s comprehension influences the outcome. However, in short-text evaluations, students with initially low scores saw improvements, making it harder to assess their true abilities. Additionally, scores were somewhat lower when evaluators believed AI might have been used, regardless of whether it was actually employed. These findings suggest that the evaluation criteria for pre-submission assignments need to be reviewed to address the influence of generative AI in the future.journal articl
A Mathematical Framework for Logit Model in Transportation Mode Choice Analysis
Full text linkTraditional transportation demand forecasting has relied on massive zone-specific aggregations, which assume a linear demand increase. Such models may lack the flexibility needed to perform dynamic and context-sensitive analyses. Recently, disaggregated behavioral models have gained prominence for requiring less data and enabling sensitivity analyses in policy decisions. This study explores the feasibility of a model focusing on the mathematical formulation and validation of the transportation mode choice model. The study uses the logit model with a non-linear probability distribution function represented by a logistic curve and incorporates a linear combination of independent predictor variables. The mathematical model is examined for its ability to estimate choice probabilities. The methodology is formulated to be adaptable to diverse contexts that provide an analytical framework for transportation systems independently of geographic or demographic considerations.conference pape