Showing papers by "Hanyang University published in 2023"
TL;DR: In this paper , the effects of Xe irradiation doses on the NO2-sensing features of ZnO nanoparticles (NP) were investigated in the presence of high amounts of oxygen vacancies owing to irradiation at the optimized dosage.
Abstract: Thanks to their impact on gas sensing enhancement, irradiation techniques are being progressively employed in gas-sensing applications. Effects of Xe irradiation doses on the NO2-sensing features of ZnO nanoparticle (NP) was investigated in this study. In this regard, ZnO NPs were irradiated with Xe ions at doses of 1 × 1014, 1 × 1015, and 1 × 1016 ions/cm2. The NO2 gas response of irradiated ZnO NPs was superior to that of the pristine one at the optimized sensing temperature of 200 ℃. Furthermore, irradiation with a dose of 1 × 1015 ions/cm2 brought about the highest response to NO2 gas, with a response of approximately 88.5 toward 10 ppm-NO2. Additionally, the optimized sensor exhibited outstanding NO2 gas selectivity. The presence of high amounts of oxygen vacancies owing to irradiation at the optimized dosage mainly resulted in the high response. This study can be used as guidelines to conduct similar studies on other materials to enhance their gas-sensing characteristics.
6 citations
18 Jan 2023
TL;DR: In this paper , a novel non-flammable fluorinated ester electrolyte was designed to enable high cycling stability in wide-temperature variations (e.g., -50 °C-60 °C) and superior power capability (fast charge rates up to 5.0 C).
Abstract: Electrolyte design has become ever more important to enhance the performance of lithium-ion batteries (LIBs). However, the flammability issue and high reactivity of the conventional electrolytes remain a major problem, especially when the LIBs are operated at high voltage and extreme temperatures. Herein, we design a novel non-flammable fluorinated ester electrolyte that enables high cycling stability in wide-temperature variations (e.g., -50 °C-60 °C) and superior power capability (fast charge rates up to 5.0 C) for the graphite||LiNi0.8 Co0.1 Mn0.1 O2 (NCM811) battery at high voltage (i.e., >4.3 V vs. Li/Li+ ). Moreover, this work sheds new light on the dynamic evolution and interaction among the Li+ , solvent, and anion at the molecular level. By elucidating the fundamental relationship between the Li+ solvation structure and electrochemical performance, we can facilitate the development of high-safety and high-energy-density batteries operating in harsh conditions.
6 citations
TL;DR: In this article , the authors of ChatGPT expressed their position that this chatbot cannot be listed as an author in the papers they published, since the text automatically generated by an AI chatbot is not a copyrighted work.
Abstract: At the end of 2022, the appearance of ChatGPT, an artificial intelligence (AI) chatbot with amazing writing ability, caused a great sensation in academia. The chatbot turned out to be very capable, but also capable of deception, and the news broke that several researchers had listed the chatbot (including its earlier version) as co-authors of their academic papers. In response, Nature and Science expressed their position that this chatbot cannot be listed as an author in the papers they publish. Since an AI chatbot is not a human being, in the current legal system, the text automatically generated by an AI chatbot cannot be a copyrighted work; thus, an AI chatbot cannot be an author of a copyrighted work. Current AI chatbots such as ChatGPT are much more advanced than search engines in that they produce original text, but they still remain at the level of a search engine in that they cannot take responsibility for their writing. For this reason, they also cannot be authors from the perspective of research ethics.
3 citations
TL;DR: In this article , a preparation of novel Ni-rich cathode material with isolated porous layer and its application into cathode in lithium ion batteries extending cutoff potential into 4.5 V was reported.
3 citations
TL;DR: In this article , the authors directly applied compressive loads on synthetic C-S-H pastes with Ca/Si ratios of 0.6-1.2 and investigated their mechanical properties using the elastic modulus calculated at three length scale levels (i.e., angstrom to nanometer, micrometer, and millimeter).
2 citations
TL;DR: In this paper , the authors used the normalized version of PS×(1-PS) with PS denoting the propensity score to estimate the overlap weight (OW), i.e., when subjects in one group have the best overlap with the other group.
2 citations
TL;DR: In this article , the authors of ChatGPT expressed their position that this chatbot cannot be listed as an author in the papers they published, since the text automatically generated by an AI chatbot is not a copyrighted work.
Abstract: At the end of 2022, the appearance of ChatGPT, an artificial intelligence (AI) chatbot with amazing writing ability, caused a great sensation in academia. The chatbot turned out to be very capable, but also capable of deception, and the news broke that several researchers had listed the chatbot (including its earlier version) as co-authors of their academic papers. In response, Nature and Science expressed their position that this chatbot cannot be listed as an author in the papers they publish. Since an AI chatbot is not a human being, in the current legal system, the text automatically generated by an AI chatbot cannot be a copyrighted work; thus, an AI chatbot cannot be an author of a copyrighted work. Current AI chatbots such as ChatGPT are much more advanced than search engines in that they produce original text, but they still remain at the level of a search engine in that they cannot take responsibility for their writing. For this reason, they also cannot be authors from the perspective of research ethics.
2 citations
TL;DR: In this paper , the authors developed an h-ZTO/MoSe2 hybrid photocatalyst with multiple heterojunctions using facile electrospinning followed by a solvothermal method.
Abstract: The design of photocatalysts that encourage the conversion of CO2 into useful chemicals has been a recent topic of interest, owing to the consequences of climate change. This study develops h-ZTO/MoSe2 hybrid photocatalysts with multiple heterojunctions using facile electrospinning followed by a solvothermal method. MoSe2 nanosheets are formed inside and outside the h-ZTO hollow nanofibers (NFs), increasing the number of accessible active sites and improving the light-scattering properties, which are fundamental for improved photocatalytic performance. A hybrid photocatalyst was obtained by adjusting the h-ZTO/MoSe2 ratio, which showed significantly higher photocatalytic activity than pure h-ZTO. The morphology, structural, phase composition, and functional characteristics of the synthesized photocatalysts were investigated using FE-SEM, TEM, XRD, XPS, PL, TR-PL, and PEC. The 10 wt% h-ZTO/MoSe2 hybrid photocatalyst demonstrated the effective photocatalytic transformation of CO2 into CO, H2, and CH4 with yielding rates of 140, 64, and 33 µmolg−1h−1, respectively. Furthermore, it exhibited the highest CO2 photoreduction selectivity of 93%. This extraordinary performance can be attributed to the uniform growth of the MoSe2 on the internal and external walls of the hollow nanofibers, which enhanced their light-scattering capabilities and provided abundant active sites for the activation and desorption of CO2 throughout the reaction.
2 citations
TL;DR: In this paper , the effect of Al doping in HfZrO2 thin films was investigated from the viewpoint of the realization of a high dielectric constant and a stable anti-ferroelectric phase.
1 citations
TL;DR: In this paper , a theoretical model for predicting the noise produced by the interaction of turbulence with a shrouded propeller in an axisymmetric mean-flow was presented, which incorporates rapid distortion theory to obtain the distorted turbulent field at the propeller face.
1 citations
TL;DR: In this article , the stability of manufactured DWE was evaluated by measuring the mean water droplet diameter, water droplets diameter distribution width, waterdroplet cumulative distribution, and water drodrop diameter trend, and it was confirmed that it is most advantageous to use Span 80 in the case of refueling after manufacturing DWE in advance.
TL;DR: In this article , a strategy to suppress Mo dissolution by manipulating the oxidation state of Mo film via catalytic-oxidation reaction was reported, and the dissolution behaviors of Mo at various oxidation states were investigated according to both oxidizer and catalyst concentrations during the CMP process.
19 Apr 2023
TL;DR: In this article , through-Si-Via (TSV) interconnection is proposed as a promising technology that could achieve high density, lower energy consumption and high performance in the IC.
Abstract: In recent years, many researches have been focused on the miniaturization of the integrated circuit (IC) feature size to improve the performance of semiconductor devices. However, we are facing the problems such as physical limit of the miniaturization and then increasing processing cost. To overcome these problems the Through-Si-Via (TSV) interconnection, a kind of the 3D interconnection, is a promising technology that could achieve high density, lower energy consumption and high performance in the IC.
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TL;DR: In this paper , a high-resolution version of the Energy Exascale Earth System Model (E3SM-HR) was used to simulate the formation of open-ocean polynyas (OOPs) in the Weddell Sea.
Abstract: Abstract. Antarctic Bottom Water is an important component of Earth's climate system. Its formation occurs through ocean-atmosphere-sea ice flux interactions in coastal and open ocean polynyas around Antarctica. In this paper, we investigate Antarctic dense water formation in the high-resolution version of the Energy Exascale Earth System Model (E3SM-HR). The model is able to reproduce the major Antarctic coastal polynyas, though they are smaller in area compared to observations. E3SM-HR also simulates several occurrences of open-ocean polynyas (OOPs) in the Weddell Sea, at a higher rate than what the last 50 years of satellite sea ice observational record suggests, but similarly to other high-resolution Earth System Model simulations. Furthermore, the densest water masses in the model are formed within the OOPs, rather than on the continental shelf, as is typically observed. Biases related to the lack of dense water formation on the continental shelf are associated with overly strong atmospheric polar easterlies, which lead to a strong Antarctic Slope Front and hence too little communication between on and off continental shelf water masses. Strong polar easterlies also produce excessive southward Ekman transport, causing a build-up of sea ice over the continental shelf and enhanced ice melting in the summer season. This in turn produces water masses on the continental shelf that are overly fresh and less dense relative to observations. Our results indicate that the large-scale polar atmospheric circulation around Antarctica must be accurately simulated in models to properly reproduce Antarctic dense water formation.
01 Jan 2023
TL;DR: In this paper , a deep engagement with ontology of immanence is proposed to address the splitting of identity scholarship in International Relations (IR) and argues that we can address this splitting through the deep engagement of identity scholars to ontology, which is new to constructivist and identity scholarship.
Abstract: In this introductory chapter, I present rationales and contextual background for this book which aims to address the question of how we, International Relations (IR) scholars, can deepen our understanding of identity. Although the contributions of IR scholars, specifically those of constructivist IR scholars, to the study of identity are dense, it is true that the discipline’s identity scholarship remains divided and incoherent. A thorny problem embedded deep within the contemporary identity scholarship in IR is that the single term “identity” is used to describe both “sameness” and “difference”\“sameness\” and \“difference\” and to make sense of contradicting realties, designating “both a foundational, essential element of human action and a fragmented, fluctuating Self.” This contraction makes it difficult for identity scholarship to meet its internal validity standard (coherence) and hinders the accumulation of knowledge and progress in understanding what identity is and how or why it matters. This chapter briefly examines how the splitting of identity scholarship has taken shape in IR and argues that we can address the splitting through a deep engagement with ontology of immanence, which is new to constructivist and identity scholarship in the discipline.
01 Jan 2023
TL;DR: This article developed a typology of identity research that not only describes the analytical, theoretical, and epistemological orientations involved, but also maps its ontological underpinnings.
Abstract: How has identity been understood, theorized, and analyzed in IR? This chapter develops a typology of identity research that not only describes the analytical, theoretical, and epistemological orientations involved, but also (and more importantly) maps its ontological underpinnings. This typological map deepens our understanding of identity-based IR studies, which are currently reviewed mainly from thematic or paradigmatic perspectives. Based on this broadened mapping exercise, this chapter demonstrates that identity studies in IR generally cohere around two discrete understandings of being, substantialism and correlationism, and that their analytical, theoretical, and epistemological orientations are split along those lines. This takes us back to a puzzle introduced at the beginning of this book, namely “How can the single word “identity” be given such radically different ontological meanings and analytical values?”
TL;DR: In this paper , the authors examined the moderating role of project type between project delivery system (PDS) and cost performance to decide whether project types should be addressed prior to evaluating PDS performance.
Abstract: This study examines the moderating role of project type between project delivery system (PDS) and cost performance to decide whether project types should be addressed prior to evaluating PDS performance. Previous studies evaluating PDSs performance using direct relationship analysis present controversial assessments in terms of cost-efficiency. They recognize that project type causes inconsistencies when comparing design–build (DB) and design–bid–build (DBB) systems. However, they have yet to determine the specific role of the project type, leading to ambiguity regarding how to control the project type (e.g., a dataset using unspecified or mixed project types). This study employed a moderation analysis to identify the role of project type and to compare the cost performance of DB and DBB systems associated with project types as a post hoc test, leveraging statistical methodology, based on 90 public building projects in Seoul, South Korea. The results show that the moderating effect of project type is statistically significant. The cost growth in DB for nonresidential building projects presents statistically lower than that in DBB, whereas the cost growth difference between DB and DBB for residential buildings is not statistically significant. Additional analysis of full life-cycle cost performance shows another dimension of comparison that indicates the cost performance comparison of DB and DBB projects is controversial and more likely to be influenced by other factors. This study contributes to the engineering in the management body of knowledge by distinguishing the effects of project type and PDS on cost performance using a causal relationship analysis. The findings provide objective criteria for public-sector practitioners in the Architecture, Engineering, and Construction industry on how to address project types when they evaluate and select PDS and enhance the consistency of PDS evaluation in terms of cost performance.
27 Mar 2023
TL;DR: In this paper , the fermion spectral function in the presence of the Cooper pair condensation and identified the interaction type of complex scalar and fermions, which gives consistent results with the expected s-wave superconductor for the first time.
Abstract: A bstract We reconsider the fermion spectral function in the presence of the Cooper pair condensation and identified the interaction type of complex scalar and fermion, which gives consistent results with the expected s-wave superconductor for the first time. We derive the matrix Riccati equation, which allows the precise calculation of the fermion spectral function. Apart from the gap structure, we studied the effect of the chemical potential and the density and compared it with the BCS theory. We found that two theories give similar results in small chemical potential but very different ones in the high-density case, which we attribute to the correlation effect.
TL;DR: In this article , the authors examined the effects of procedural justice and authority power on corporate taxpayers' decisions to accept tax audit assessments via an experiment related to a hypothetical tax audit and found that authority power but not procedural justice increases corporate taxpayers acceptance of tax authority decisions in a tax audit situation.
Abstract: This study examines the effects of procedural justice and authority power on corporate taxpayers’ decisions to accept tax audit assessments via an experiment related to a hypothetical tax audit. We find that authority power but not procedural justice increases corporate taxpayers’ acceptance of tax authority decisions in a tax audit situation. However, when authority power is low, there is a significant effect of procedural justice in a tax audit on taxpayers’ aggressiveness in their decisions to accept tax audit assessments. According to the results, a combination of policy measures that enhance procedural justice and traditional deterrence measures warrants consideration to increase overall corporate tax compliance.
TL;DR: In this paper , a novel adsorbent-coated heat exchanger (ACHE) with high durability and conductivity is presented to enhance the heat and mass transfer rates during the adsorption and desorption processes.
TL;DR: In this paper , a research model is proposed to describe relationships among different types of functional company characteristics (i.e. quality, innovation, and price) on perceived value and behavioral intentions, and impact of operational involvement in the context of franchisees.
Abstract: Purpose Due to increasing competition, creating and enhancing franchisee patronage behaviors are critical elements in the food franchise industry. Franchise brand-related characteristics are known to influence franchisees’ evaluations. Thus, this paper examines the antecedents of franchisees’ perceived value, which leads to positive behaviors in the food franchise sector.Design/methodology/approach A research model is proposed to describe relationships among different types of functional company characteristics (i.e. quality, innovation, and price) on perceived value and behavioral intentions, and impact of operational involvement in the context of franchisees. A quantitative approach was leveraged to collect 266 usable online questionnaires, together with SmartPLS to analyze the measurement model and proposed hypotheses.Findings Results show that perceived quality on the part of franchisees is the most significant determinant of perceived value, followed by perceived innovation and price. Also, the impact of perceived value on franchisees’ intentions – including continuous and word-of-mouth intentions – is supported. Last, the role of operational involvement (i.e. duration and number of food franchise operations) in perceived value is examined.Originality/value To add to the limited research in the behaviors of franchisees, this study provides useful insights to achieve sustainable growth in the franchise brand context.
01 Feb 2023
TL;DR: In this paper , the authors discussed heat transfer in thin liquid films past a stretching surface in the presence of Joule heating, radiation, viscous dissipation, and magnetic effects.
Abstract: The present work discusses heat transfer in thin liquid films past a stretching surface in the presence of Joule heating, radiation, viscous dissipation, and magnetic effects. Using a suitable similarity transformation, the nonlinear coupled partial differential equations are reduced to nonlinear ordinary differential equations. The coupled nonlinear ordinary differential equations are then solved by using the shooting method. The physical quantities, such as the unsteadiness parameter, the Prandtl number, the magnetic field parameter, the radiation parameter, and the viscous dissipation parameter on temperature distributions, are depicted graphically. It is observed that the effects of Prandtl and Eckert numbers are same over the temperature distribution. Furthermore, it is also evident that the increasing values of the unsteadiness parameter enhance the thermal conductivity of the fluid.
TL;DR: In this paper , a novel hydrodynamic sequencing batch reactor (H-SBR) was developed to enhance the oxygen transfer rate (OTR) and nitrite accumulation ratio (NAR) by modifying internal hydrodynamynamic turbulence intensity.
Abstract: This study introduced an alternative shortcut biological nitrogen removal (SBNR) process for landfill leachate treatment by developing a novel hydrodynamic sequencing batch reactor (H-SBR). The reactor could enhance the oxygen transfer rate (OTR) and nitrite accumulation ratio (NAR) by modifying internal hydrodynamic turbulence intensity. The average chemical oxygen demand (COD) and total nitrogen (TN) concentrations introduced into the reactor were 660 and 250 mg L−1, respectively, and the average removal efficiencies were 93% (COD) and 96% (TN). The effect of geometric parameters on oxygen transfer was estimated by performing a hydrodynamic model and a nonlinear least square analysis. After correcting the constants (α and β) of mass transfer coefficients (KLa) to values of 0.7361 and 1.2639, the model data fit the experiment well with an R-squared value of 0.99. The OTR improved by up to 30%, and hence, increased the NAR by up to 20% with a reduction of about 0.5 kg N kW−1 for power efficiency. The H-SBR development is innovative because the oxygen transfer efficiency was improved by the hydrodynamic modification of internal turbulence intensity, although not by mechanical equipment or chemical supplements. For the SBNR process, the modification of the reactor configuration for OTR enhancement could significantly improve nitrogen removal efficiency with successful nitrite accumulation. In addition to landfill leachate treatment, the H-SBR process can be employed in the treatment of low C/N ratio wastewaters.
15 May 2023
TL;DR: In this article , the authors proposed an approach to dynamic drought vulnerability assessment that can be used to secure elasticity for water demand and supply during a drought event and further respond to a preemptive drought.
Abstract: Globally, drought affects different types of regions and countries, making it one of the most devastating natural disasters in terms of impacts on agriculture and food security, ecosystems, human health, and water resources. As the importance of integrated drought management including disaster risk reduction, climate change adaptation strategies, and national water policies is emphasized internationally, it is important to develop an effective water management technology for proactive drought response rather than reactive drought management to cope with drought disaster. In this study, we propose an approach to dynamic drought vulnerability assessment that can be used to secure elasticity for water demand and supply during drought event and further respond to a preemptive drought. Drought response and management based on this dynamic drought vulnerability assessment technology has consistency in that it promotes an internationally pursued convergence strategy for climate change adaptation and disaster risk reduction. The dynamic drought vulnerability assessment is based on the water demand-supply linkage assessment in various types of droughts. In other words, this is a technology for improving the ability to respond to drought through flexible water supply in the actual drought events. Dynamic drought vulnerability assessment produces various types of drought vulnerability map considering various scenarios of drought occurrence and socio-economic pathways according to climate change. For example, when combining hydrological drought scenarios considering climate change (25 types), water demand scenarios according to social/economic/environmental changes (3 types), water supply scenarios of drought damage/sensitivity by region (4 types), storage ratio scenarios of dam and reservoir (12 types), at least 2100 scenarios are produced as database. In the future, these results can be used as a basis for scientific decision-making in preparing countermeasures to improve resilience to drought.Acknowledgement: This work was supported by the Korea Environment Industry & Technology Institute (KEITI) through Water Management Innovation Program for Drought (No. 2022003610001) funded by Korea Ministry of Environment.
TL;DR: In this paper , the Laia-Tong model is shown to realize the Lieb lattice in the holographic setup and it generates a flat band of sharp particle spectrum together with a Dirac band of unparticle spectrum.
Abstract: A bstract We first point out that the Laia-Tong model realizes the Lieb lattice in the holographic setup. It generates a flat band of sharp particle spectrum together with a Dirac band of unparticle spectrum. We provided an understanding why the Laia-Tong model’s boundary condition generate a flat band and compared it with the mechanism of “compact localized orbits” in the lattice models to provide a physical reason why Lieb and Laia-Tong model should be identified based on the similarity in the flat band generation mechanism. We then construct a model which opens a gap to the Dirac band so that one can realize a well-separated flat band. We then study the phase transition between the gapped and gapless phases analytically. We also made methodological progress to find a few other possible quantizations and we express the Green functions in any quantization in terms of that in the standard quantization. Finally we carried out the problem of back reaction to show that the qualitative feature remains the same.
TL;DR: In this article , the authors studied local regularity properties of minimizers of nonlocal variational functionals with variable exponents and weak solutions to the corresponding Euler-Lagrange equations.
Abstract: In this paper, we study local regularity properties of minimizers of nonlocal variational functionals with variable exponents and weak solutions to the corresponding Euler–Lagrange equations. We show that weak solutions are locally bounded when the variable exponent p is only assumed to be continuous and bounded. Furthermore, we prove that bounded weak solutions are locally Hölder continuous under some additional assumptions on p. On the one hand, the class of admissible exponents is assumed to satisfy a log-Hölder–type condition inside the domain, which is essential even in the case of local equations. On the other hand, since we are concerned with nonlocal problems, we need an additional assumption on p outside the domain.
TL;DR: Wang et al. as discussed by the authors proposed a vulnerability detection model, V-CNN, which aims to detect CWE/CVE (Common Weakness Enumeration/Common Vulnerabilities and Exposures) using CNN.
Abstract: Abstract With the advent of the Internet, the activities of individuals and businesses have expanded into the online realm. As a result, vulnerabilities that result in actual breaches can lead to data loss and program failure. The number of breaches is increasing every year, as is the number of vulnerabilities. To address this problem, current research focuses on the detection of vulnerabilities using static analysis techniques. To prevent the propagation of vulnerabilities, a new paradigm is needed to quickly detect vulnerabilities, analyze them, and take actions such as blocking or removing them. Recently, artificial intelligence algorithms such as deep learning have been introduced for vulnerability detection. In this paper, we propose a vulnerability detection model, V-CNN, which aims to detect CWE/CVE (Common Weakness Enumeration/Common Vulnerabilities and Exposures) using CNN (convolutional neural network). We trained CWE for deep learning and redefined vulnerabilities based on CWE. We propose an experimental algorithm to improve vulnerability detection. The accuracy of the proposed V-CNN model is 98%, which exceeds the 95% of the random forest model. Therefore, our V-CNN has excellent correctness detection performance in the field of vulnerability detection. The V-CNN vulnerability detection algorithm can be used instead of static analysis to detect various security vulnerabilities.
TL;DR: In this paper , the thermal expansion of spin-coated poly(methyl methacrylate) was investigated using an atomic force microscope, and it was shown that the collective motion of side groups along backbone chains uniquely drives the enhancement of thermal expansion anisotropy of polymers.
Abstract: While dimensional change under thermal loading dictates various device failure mechanisms in soft materials, the interplay between microstructures and thermal expansion remains underexplored. Here, we develop a novel method to directly probe the thermal expansion for nanoscale polymer films using an atomic force microscope as well as confining active thermal volume. In a model system, spin-coated poly(methyl methacrylate), we find that the in-plane thermal expansion is enhanced by 20-fold compared to that along the out-of-plane directions in confined dimensions. Our molecular dynamics simulations show that the collective motion of side groups along backbone chains uniquely drives the enhancement of thermal expansion anisotropy of polymers in the nanoscale limit. This work unveils the intimate role of the microstructure of polymer films on its thermal-mechanical interaction, paving a route to judiciously enhance the reliability in a broad range of thin-film devices.