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Context-aware Workflow Model for Supporting Composite Workflows

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Journal of Measurement Science and Instrumentation 2010年第2期1卷 161-165页

作者： jong-sun choi Jae-young choi Yong-yun CHO School of Computing Soongsil -University Seoul-156-743 Korea Division of Information and Communication Sunchon National University Jeonnam 540- 742 Korea

In recent years, several researchers have applied workflow technologies for service automation on ubiquitous compating environments. However, most context-aware workflows do not offer a method to compose several workflows in order to get mare large-scale or complicated workflow. They only provide a simple workflow model, not a composite workflow model. In this paper, the autorhs propose a context-aware workflow model to support composite workflows by expanding the patterns of the existing context-aware wrY：flows, which support the basic woddlow patterns. The suggested workflow model of. fers composite workflow patterns for a context-aware workflow, which consists of various flow patterns, such as simple, split, parallel flows, and subflow. With the suggested model, the model can easily reuse few of existing workflows to make a new workflow. As a result, it can save the development efforts and time of context-aware workflows and increase the workflow reusability. Therefore, the suggested model is expected to make it easy to develop applications related to context-aware workflow services on ubiquitous computing environments.

关键词： ubiquitous computing context-aware workfiow workflow model multiple workflows

Correlation between hydration properties and electrochemical performances on Ln cation size effect in layered perovskite for protonic ceramic fuel cells

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Journal of Energy Chemistry 2024年第1期88卷 1-9,I0001页

作者： Inhyeok Cho Jiwon Yun Boseok Seong Junseok Kim sun Hee choi Ho-Il Ji Sihyuk choi Department of Mechanical Engineering Kumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Department of Aeronautics Mechanical and Electronic Convergence EngineeringKumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Center for Energy Materials Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Center for Hydrogen and Fuel Cell Research Clean Technology Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Energy and Environmental Engineering University of Science and TechnologySeoul 02792Republic of Korea Nanomaterials Science and Engineering Korea University of Science and Technology(UST)KIST CampusSeoul 02792Republic of Korea

PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.

关键词： Protonic ceramic fuel cell Cathode Triple ionic and electronic conductor Hydration property Proton uptake Gibbs free energy

Bidirectional rotating direct-current triboelectric nanogenerator with self-adaptive mechanical switching for harvesting reciprocating motion

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International Journal of Extreme Manufacturing 2024年第4期6卷 324-335页

作者： Donghan Lee Joonmin Chae Sumin Cho jong Woo Kim Awais Ahmad Mohammad Rezaul Karim Moonwoo La sung Jea Park Dongwhi choi Department of Mechanical Engineering(Integrated Engineering Program) Kyung Hee University1732 Deogyeong-daeroYonginGyeonggi 17104Republic of Korea Department of Chemistry University of LahoreLahorePakistan Department of Mechanical Engineering College of EngineeringKing Saud UniversityRiyadh 11421Saudi Arabia School of Mechanical Engineering Korea University of Technology and Education1600 Chungjeol-roCheonanChungnam 31253Republic of Korea

Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic ***,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a ***,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating *** distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC ***,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational *** to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC *** of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this *** study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices.

关键词： direct-current triboelectric nanogenerator mechanical rectification self-adaptive mechanical design harvesting reciprocation motion

Virtual vibration test rig for fatigue analysis of dozer push arms

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International Journal of Mechanical System Dynamics 2024年第3期4卷 278-291页

作者： Lei Hou Weibin Li Wenyan Gu Zizheng sun Xiangqian Zhu Jin-Hwan choi Key Laboratory of High-Efficiency and Clean Mechanical Manufacture of MOE National Demonstration Center for Experimental Mechanical EngineeringSchool of Mechanical EngineeringShandong UniversityJinanChina Rizhao Research Institute of Shandong University RizhaoChina School of Aerospace Engineering Xiamen UniversityXiamenChina School of Qilu Transportation Shandong UniversityJinanChina Department of Mechanical Engineering Kyunghee UniversitySeoulSouth Korea

To obtain accurate fatigue life results for construction machinery components,acquiring load spectra is crucial,as their authenticity and validity directly determine the precision of the *** working conditions,component attitudes change continuously,but they remain static on the vibration test rig(VTR),so the acquired target signals should match with the actual component attitudes in the driving signal *** paper proposes an efficient and economical simulation-based virtual VTR for fatigue analysis of ***,the relationship between the push arm rotation angle and the cylinder stroke is established,since the cylinder strokes can be measured easily in data acquisition ***,load decomposition is used to determine the attitude relationship between virtual VTR conditions and actual conditions,and target signals are calculated based on this attitude relationship and measured *** to the system's frequency response function,the driving signals are iterated until the system's response signals converge with the target ***,the iteratively obtained load spectra are utilized for fatigue life *** results show that the virtual VTR can effectively and accurately obtain the results of fatigue analysis and has engineering application significance.

关键词： virtual vibration test rig driving signal generation component attitudes fatigue analysis dozer push arm

Tailoring local structures of atomically dispersed copper sites for highly selective CO_(2) electroreduction

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Carbon Energy 2024年第4期6卷 79-90页

作者： Kyung‐jong Noh Byoung Joon Park Ying Wang Yejung choi Sang‐Hoon You Yong‐Tae Kim Kug‐Seung Lee Jeong Woo Han Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbukRepublic of Korea Department of Materials Science and Engineering Pohang University of Science and Technology(POSTECH)PohangGyeongbukRepublic of Korea Pohang Accelerator Laboratory(PAL) Beamline DivisionPohangGyeongbukRepublic of Korea

Atomically‐dispersed copper sites coordinated with nitrogen‐doped carbon(Cu–N–C)can provide novel possibilities to enable highly selective and active electrochemical CO_(2) reduction ***,the construction of optimal local electronic structures for nitrogen‐coordinated Cu sites(Cu–N_(4))on carbon remains ***,we synthesized the Cu–N–C catalysts with atomically‐dispersed edge‐hosted Cu–N_(4) sites(Cu–N_(4)C_(8))located in a micropore between two graphitic sheets via a facile method to control the concentration of metal ***‐hosted Cu–N_(4)C_(8) catalysts outperformed the previously reported M–N–C catalysts for CO_(2)‐to‐CO conversion,achieving a maximum CO Faradaic efficiency(FECO)of 96%,a CO current density of–8.97 mA cm^(–2) at–0.8 V versus reversible hydrogen electrode(RHE),and over FECO of 90%from–0.6 to–1.0 V versus *** studies revealed that the micropore of the graphitic layer in edge‐hosted Cu–N_(4)C_(8) sites causes the d‐orbital energy level of the Cu atom to shift upward,which in return decreases the occupancy of antibonding states in the*COOH *** research suggests new insights into tailoring the locally coordinated structure of the electrocatalyst at the atomic scale to achieve highly selective electrocatalytic reactions.

关键词： atomic local structure density functional theory electrochemical CO_(2)reduction metal nitrogen‐doped carbon single‐atom catalyst

Adiponectin restores the obesity-induced impaired immunomodulatory function of mesenchymal stromal cells via glycolytic reprogramming

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Acta Pharmaceutica Sinica B 2024年第1期14卷 273-291页

作者： Duc-Vinh Pham Thi-Kem Nguyen Bao-Loc Nguyen jong-Oh Kim Jee-Heon Jeong Inho choi Pil-Hoon Park Department of Pharmacology Hanoi University of PharmacyHanoi 100000Viet Nam College of Pharmacy Yeungnam UniversityGyeongsan 38541Republic of Korea Department of Medical Biotechnology Yeungnam UniversityGyeongsan 38541Republic of Korea Research Institute of Cell Culture Yeungnam UniversityGyeongsan 38541Republic of Korea Department of Precision Medicine School of MedicineSungkyunkwan UniversitySuwon 16419Republic of Korea

Obesity has been known to negatively modulate the life-span and immunosuppressive potential of mesenchymal stromal cells(MSC).However,it remains unclear what drives the compromised potency of obese *** this study,we examined the involvement of adiponectin,an adipose tissuederived hormone,in obesity-induced impaired therapeutic function of ***-induced obesity leads to a decrease in serum adiponectin,accompanied by impairment of survival and immunomodulatory effects of adipose-derived MSC(ADSC).Interestingly,priming with globular adiponectin(gAcrp)improved the immunomodulatory potential of obese *** effects were also observed in lean *** addition,gAcrp potentiated the therapeutic effectiveness of ADSC in a mouse model of DSS-induced ***,while obesity inhibited the glycolytic capacity of MSC,gAcrp treatment induced a metabolic shift toward glycolysis through activation of adiponectin receptor type 1/p38 MAPK/hypoxia inducible factor-1a *** findings suggest that activation of adiponectin signaling is a promising strategy for enhancing the therapeutic efficacy of MSC against immune-mediated disorders.

关键词： Adiponectin Adipose-derived stromal cells Colitis Glycolytic induction HIF1a Immunomodulation Mesenchymal stromal cells Obesity

Submicron Ag-coated Cu particles as filler in sintering paste: Suppression of Ag dewetting and improvement of sinterability by surface modification using stearic acid

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Transactions of Nonferrous Metals Society of China 2024年

作者： Yeongjung Kim Yong-sung Eom Kwang-Seong choi jong-Hyun Lee Department of Materials Science and Engineering， Seoul National University of Science and Technology， 232 Gongneung-ro Low-Carbon Integration Tech， Creative Research Section， ETRI， 218 Gajeong-ro Materials Research Institute for Future Convergence， Seoul National University of Science and Technology， 232 Gongneung-ro

Four types of submicron Ag-coated Cu particles with different Ag contents were prepared as sintering paste fillers， and the Ag contents of the particles were measured to be 10， 20， 30， and 40 wt%. Four types of particles （in order of increasing Ag content: A10， A20， A30， and A40） were surface-modified with stearic acid， to suppress the Ag shell dewetting and improve sinterability. The surface-modified particles were mixed with a polyol-based solvent to fabricate a resin-free paste. Subsequently， the pastes were screen-printed onto a slide glass and sintered at 250 ℃ in a nitrogen atmosphere for 1–10 min to form an electrode. The electrical resistivity of the sintered film as a function of sintering time was measured using a four-point probe. All the four surface-modified Cu@Ag particles with different Ag contents exhibited decreased electrical resistivity. Particularly， the largest difference in values after and before the surface modification was observed for A40 with the highest Ag content; the electrical resistivities of the initial and surface-modified particles were 1.51×10-4and 6.67×10-5Ω·cm， respectively， after sintering for 10 min. The findings of this study confirmed that the surface modification using stearic acid effectively suppressed the dewetting of the Ag shell and improved the sinterability of the submicron Cu@Ag particles.

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Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho Lee Hyeon Jun Jeon Jinwoo choi Hyun-Taek choi Sejin Lee The Department of Mechanical Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System Engineering Research Division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The Division of Mechanical&Automotive Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

Unravelling the role of the combined effect of metallic charge transfer channel and SiO_(x) overlayer in the Zr/Si-Fe_(2)O_(3):Au:SiO_(x) nanorod arrays to boost photoelectrochemical water splitting

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Journal of Energy Chemistry 2024年第3期90卷 370-379,I0009页

作者： Tae Sik Koh Periyasamy Anushkkaran Love Kumar Dhandole Mahadeo A.Mahadik Weon-Sik Chae Hyun Hwi Lee sun Hee choi Jum Suk Jang Division of Biotechnology SafetyEnvironment and Life Science InstituteCollege of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54896Republic of Korea Department of Integrative Environmental Biotechnology College of Environmental and Bioresource SciencesJeonbuk National UniversityIksan 54596Republic of Korea Extreme Materials Research Center Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Daegu Center Korea Basic Science InstituteDaegu 41566Republic of Korea Pohang Accelerator Laboratory Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea

Hematite(α-Fe_(2)O_(3)) based photoanodes have been extensively studied due to various intriguing features that make them viable candidates for a photoelectrochemical(PEC) water splitting ***,we propose a Zr-doped Fe_(2)O_(3) photoanode decorated with facilely spin-coated Au nanoparticles(NPs) and microwave-assisted attached Si co-doping in conjunction with a SiO_(x) overlayer that displayed a remarkable photocurrent density of 2.01 mA/cm^(2) at 1.23 V *** kinetic dynamics at the photoelectrode/-electrolyte interface was examined by employing systematic electrochemical *** Au NPs played a dual role in increasing PEC water ***,the Schottky interface that was formed between Au NPs and Zr-Fe_(2)O_(3) lectrode ensured the prevention of electron flow from the photoanode to the metal,increasing the number of available charges as well as suppressing surface charge ***,Au extracted photoholes from the bulk of the Zr-Fe_(2)O_(3) and transported them to the outer SiO_(x) overlayer,while the SiO_(x) overlayer efficiently collected the photoholes and promoted the hole injection into the ***,Si co-doping enhanced bulk conductivity by reducing bulk charge transfer resistance and improving charge carrier *** study outlines a technique to design a metallic charge transfer path with an overlayer for solar energy conversion.

关键词： Hematite Microwave attachment Au nanoparticles SiO_(x) overlayer Water splitting