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Journal of Rock Mechanics and Geotechnical Engineering 2023年第3期15卷 747-759页

作者： Abiodun Ismail Lawal Sangki kwon Department of Energy Resources Engineering Inha UniversityIncheonSouth Korea Department of Mining Engineering Federal University of TechnologyAkureNigeria

Ultimate bearing capacity(UBC)is a key subject in geotechnical/foundation engineering as it determines the limit of loads imposed on the *** most reliable means of determining UBC is through experiment,but it is costly and time-consuming which has led to the development of various models based on the simplified *** outcomes of the models are usually validated with the experimental results,but a large gap usually exists between ***,a model that can give a close prediction of the experimental results is *** study proposes a grasshopper optimization algorithm(GOA)and salp swarm algorithm(SSA)to optimize artificial neural networks(ANNs)using the existing UBC experimental *** performances of the proposed models are evaluated using various statistical *** obtained results are compared with the existing *** proposed models outperformed the existing *** proposed hybrid GOA-ANN and SSA-ANN models are then transformed into mathematical forms that can be incorporated into geotechnical/foundation engineering design codes for accurate UBC measurements.

关键词： Ultimate bearing capacity(UBC) Geotechnics Grasshopper optimization algorithm(GOA) Salp swarm algorithm(SSA) Soft computing(SC)method

PRODUCTION AND DECAy OF b-FLAVORED HADRONS

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Chinese Physics C 2016年第10期40卷 746-758页

作者： P. Eerola M. kreps y. kwon U. of Helsinki Helsinki Finland U. of Warwick Coventry UK yonsei U. Seoul Korea

The b quark belongs to the third generation of quarks and is the weak-doublet partner of the t quark. The existence of the third-generation quark doublet was proposed in 1973 by kobayashi and Maskawa [1] in their model of the quark mixing matrix （＂CkM＂ matrix）, and confirmed four years later by the first observation of a bb meson [2]. In the kM model, CP violation is explained within the Standard Model （SM） by an irreducible phase of the 3 × 3 unitary matrix. The regular pattern of the three lepton and quark families is one of the most intriguing puzzles in particle physics. The existence of families gives rise to many of the free parameters in the SM, including the fermion masses, and the elements of the CkM matrix.

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Emotional inference by means of Choquet integral and λ-fuzzy measurement in consideration of ambiguity of human mentality

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Journal of Central South University 2016年第1期23卷 160-168页

作者： kwon Il-kyoung LEE Sang-yong Division of Computer Science & Engineering Kongju National University Department of Computer Science & Engineering Kongju National University

Research on human emotions has started to address psychological aspects of human nature and has advanced to the point of designing various models that represent them quantitatively and systematically. Based on the findings, a method is suggested for emotional space formation and emotional inference that enhance the quality and maximize the reality of emotion-based personalized services. In consideration of the subjective tendencies of individuals, AHP was adopted for the quantitative evaluation of human emotions, based on which an emotional space remodeling method is suggested in reference to the emotional model of Thayer and Plutchik, which takes into account personal emotions. In addition, Sugeno fuzzy inference, fuzzy measures, and Choquet integral were adopted for emotional inference in the remodeled personalized emotional space model. Its performance was evaluated through an experiment. Fourteen cases were analyzed with 4.0 and higher evaluation value of emotions inferred, for the evaluation of emotional similarity, through the case studies of 17 kinds of emotional inference methods. Matching results per inference method in ten cases accounting for 71% are confirmed. It is also found that the remaining two cases are inferred as adjoining emotion in the same section. In this manner, the similarity of inference results is verified.

关键词： fuzzy measure fuzzy integral emotional model emotion space AHP fuzzy inference system Choquet integral

Functionally Graded Dual-nanoparticulate-reinforced Aluminium Matrix Bulk Materials Fabricated by Spark Plasma Sintering

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Journal of Materials Science & Technology 2014年第8期30卷 736-742页

作者： Hansang kwon Marc Leparoux Akira kawasaki Department of Materials System Engineering Pukyong National University365 Sinsenro608-759 BusanKorea Empa Swiss Federal Laboratories for Materials Science and TechnologyAdvanced Materials ProcessingFeuerwerkerstrasse 39CH-3602 ThunSwitzerland Department of Materials Processing Engineering Graduate School of EngineeringTohoku University980-8579 SendaiJapan

Functionally graded（FG） carbon nanotubes（CNT） and nano-silicon carbide（nSiC） reinforced aluminium（Al）matrix composites have been successfully fabricated using high-energy ball milling followed by solid-state spark plasma sintering *** CNTs were well-dispersed in the Al particles using the nSiC as a solid mixing *** different types of multi-walled CNTs were used to add different amounts of CNTs in the same *** ball milled Al—CNT—nSiC and Al—CNT powder mixtures were fully densified and demonstrated good adhesion with no serious microcracks and pores within an FG multilayer *** layer contained different amounts of the CNTs,and the nSiC additions showed different microstructures and *** is possible to control the characteristics of the FG multilayer composite through the efficient design of an Al—CNT—nSiC gradient *** concept offers a feasible approach for fabricating the dualnanoparticulate-reinforced Al matrix nanocomposites and can be applied to other scenarios such as polymer and ceramic systems.

关键词： Carbon nanotubes(CNT) Silicon carbide High-energy ball milling Spark plasma sintering(SPS) Functionally graded materials(FGM)

kinematic Analysis of the Neck and Upper Extremities During Walking in Healthy young Adults

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Journal of Bionic Engineering 2011年第3期8卷 305-312页

作者： kwon Son Junghong Park Seonghun Park School of Mechanical Engineering Pusan National University Busan 609-735 Republic of Korea

The objective of this paper is to quantify the local stabilities of the neck and upper extremities （right/left shoulders and right/left elbows）, and investigate differences between linear and nonlinear measurements of the associated joint motions and differences in the local stability between the upper and lower extremities. This attempt involves the calculation of a nonlinear parameter, Lyapunov Exponent （LE）, and a linear parameter, Range of Motion （ROM）, during treadmill walking in conj unction with a large population of healthy subjects. Joint motions of subjects were captured using a three-dimensional motion-capture system. Then mathematical chaos theory and the Rosenstein algorithm were employed to calculate LE of joints as the extent of logarithmic divergence between the neighboring state-space trajectories of flexion-extension angles. LEs computed over twenty males and twenty females were 0.037~0.023 for the neck, 0.043＋0.021 for the right shoulder, 0.045i0.030 for the left shoulder, 0.032i0.021 for the right elbow, and 0.034~0.026 for the left elbow. Although statistically significant difference in the ROM was observed between all pairs of the neck and upper extremity joints, differences in the LE between all pairs of the joints as well as between males and females were not statistically significant. Between the upper and lower extremities, LEs of the neck, shoulder, and elbow were significantly smaller than those of the hip （-0.064） and the knee （-0,062）. These results indicate that a statistical difference in the local stability between the upper extremity joints is not significant. However, the different result between the ROM and LE gives a strong rationale for applying both linear and nonlinear tools together to the evaluation of joint movement. The LEs of the joints calculated from a large population of healthy subjects could provide normative values for the associated joints and can be used to evaluate the recovery progress of patients with joint rel

关键词： kinematic analysis Lyapunov exponent range of motion chaos theory upper extremities

Improved estimation of rotor position for sensorless control of a PMSM based on a sliding mode observer

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Journal of Central South University 2016年第7期23卷 1643-1656页

作者： Wahyu kunto Wibowo Seok-kwon Jeong Department of Electrical Engineering Universitas Pertamina Refrigeration and Air-Conditioning Engineering Pukyong National University

This work proposes a new strategy to improve the rotor position estimation of a permanent magnet synchronous motor(PMSM) over wide speed range. Rotor position estimation of a PMSM is performed by using sliding mode observer(SMO). An adaptive observer gain was designed based on Lyapunov function and applied to solve the chattering problem caused by the discontinuous function of the SMO in the wide speed range. The cascade low-pass filter(LPF) with variable cut-off frequency was proposed to reduce the chattering problem and to attenuate the filtering capability of the SMO. In addition, the phase shift caused by the filter was counterbalanced by applying the variable phase delay compensation for the whole speed area. High accuracy estimation result of the rotor position was obtained in the experiment by applying the proposed estimation strategy.

关键词： rotor position estimation permanent magnet synchronous motor sliding mode observer adaptive observer gain cascadelow-pass filter variable cut-off frequency variable phase delay compensation

An Experimental Study on Response and Control of a Flapping-Wing Aerial Robot Under Wind Gusts

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Journal of Bionic Engineering 2024年第1期21卷 209-223页

作者： kazuki Shimura Hikaru Aono Chang-kwon kang Graduate School of Science and Technology Shinshu University3-15-1 TokidaUedaNagano 3868567Japan Department of Mechanical Engineering and Robotics 3-15-1 TokidaUedaNagano 3868567Japan Department of Mechanical and Aerospace Engineering University of Alabama in HuntsvilleTechnology Hall N266HuntsvilleAL35899USA

Bioinspired flapping-wing micro-air-vehicles(FWMAVs)have the potential to be useful aerial tools for gathering information in various *** recent advancements in manufacturing technologies and better understanding of aerodynamic mechanisms behind of the flapping flight,outdoor flights have become a ***,to fully realize the potential of FWMAVs,further improvements are necessary,particularly in terms of stability and robustness under gusty *** this study,the response and control of a tailless two-winged FWMAV under the wind gusts are *** experiments are conducted with a one-degree-of-freedom gimbal to focus on effects of wind gusts on the rotational motion of the ***-derivative and sliding-mode controls are adopted for the attitude *** present that the body angles changed in time and reached approximately 50°at the maximum due to the wing *** sliding-mode controller can more effectively control the rotational angle in the presence of disturbances and both the wing speed and changes in wind speed have an impact on the effectiveness of attitude *** results contribute to the development of of tailless two-winged,single-motor driven FWMAVs in terms of the design of attitude controller and testing apparatus.

关键词： Flapping-wing micro-air vehicles Sliding-mode control Pitch and roll angle-Wind gus

Nanomechanical Characterization of Bone Quality Depending on Tissue Age via Bimodal Atomic Force Microscopy

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Nanomanufacturing and Metrology 2023年第4期6卷 24-34页

作者： Jinha kwon Hanna Cho Department of Mechanical and Aerospace Engineering The Ohio State UniversityColumbusOH 43210USA

Characterization of bone quality during the healing process is crucial for successful implantation procedures and patient *** this study,a bone implant specimen that underwent a 4-week healing period was *** atomic force microscopy(AFM)was employed to simultaneously obtain the morphology and elastic modulus maps of the newly formed and pre-existing bone regions within the *** indicate that the new bone matrix possessed lower miner-alization levels and presented larger,uneven mineral grains,exhibiting the attributes of a woven *** the other hand,the old bone matrix exhibited a more uniform and mineralized structure,which is characteristic of lamellar *** new bone had a lower overall elastic modulus than the old *** AFM further confrmed that the new bone displayed three regions comprising unmineralized,partially mineralized,and fully matured sections,which indicate a turbulent change in its ***,the old bone exhibited two sections comprising partially mineralized and matured bone parts,which denote the fnal phase of *** study provides valuable insights into the morphological and nanome-chanical diferences between the old and new bone matrixes and presents a novel approach to investigate bone quality at diferent phases of the bone-healing process.

关键词： Bone quality Atomic force microscopy Bimodal AFM Nanomechanical characterization Bone tissue age Woven bone Lamellar bone

Characteristics of damaged layer in micro-machining of copper material

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中国有色金属学会会刊：英文版 2009年第B09期19卷 295-300页

作者： Dong-Hee kwon Jeong-Suk kIM Myung-Chang kANG Se-Hun kwon Jong-Hwan LEE School of Mechanical Engineering Pusan National University National Core Research Center for Hybrid Materials Solution Pusan National University Department of Mechatronics Busan College of Korea Polytechnic Ⅶ

The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-machining characteristics, such as cutting speed, feed rate and cutting depth, of a micro-damaged layer produced by an ultra-high speed air turbine spindle. The micro cutting force, surface roughness and plastic deformation layer were investigated according to the machining conditions. The damaged layer was measured using optical microscope on samples prepared through metallographic techniques. The scale of the damaged layer depends on the cutting process parameters, particularly, the feed per tooth and axial depth of the cut. According to the experimental results, the depth of the damaged layer is increased by increasing the feed per tooth and cutting depth, also the damaged layer occurs less in down-milling compared with up-milling during the micro-machining operation.

关键词：机械加工性微观特征损伤层铜材样品制备技术微型机器切削速度切削深度

Use of Total Precipitable Water Classification of A Priori Error and Quality Control in Atmospheric Temperature and Water Vapor Sounding Retrieval

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Advances in Atmospheric Sciences 2012年第2期29卷 263-273页

作者： Eun-Han kwon Elisabeth WEISZ School of Earth and Environmental Sciences Seoul National University Seoul 151-747 Korea Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-Madison1225 West Dayton Street Madison WI 53706 USA

This study investigates the use of dynamic a priori error information according to atmospheric moistness and the use of quality controls in temperature and water vapor profile retrievals from hyperspectral infrared （IR） sounders. Temperature and water vapor profiles are retrieved from Atmospheric InfraRed Sounder （AIRS） radiance measurements by applying a physical iterative method using regression retrieval as the first guess. Based on the dependency of first-guess errors on the degree of atmospheric moistness, the a priori first-guess errors classified by total precipitable water （TPW） are applied in the AIRS physical retrieval procedure. Compared to the retrieval results from a fixed a priori error, boundary layer moisture retrievals appear to be improved via TPW classification of a priori first-guess errors. Six quality control （QC） tests, which check non-converged or bad retrievals, large residuals, high terrain and desert areas, and large temperature and moisture deviations from the first guess regression retrieval, are also applied in the AIRS physical retrievals. Significantly large errors are found for the retrievals rejected by these six QCs, and the retrieval errors are substantially reduced via QC over land, which suggest the usefulness and high impact of the QCs, especially over land. In conclusion, the use of dynamic a priori error information according to atmospheric moistness, and the use of appropriate QCs dealing with the geographical information and the deviation from the first-guess as well as the conventional inverse performance are suggested to improve temperature and moisture retrievals and their applications.

关键词： atmospheric sounding AIRS total precipitable water a priori error quality control