Kim Dae-Jin

Abstract This paper presents a generalized finite element method (GFEM) based on the solution of interdependent global (structural) and local (crack)‐scale problems. The local problems focus on the resolution of fine‐scale features of the solution in the vicinity of three‐dimensional cracks, while the global problem addresses the macro‐scale structural behavior. The local solutions are embedded into the solution space for the global problem using the partition of unity method. The local problems

This study examines the structural relationship among key factors influencing student satisfaction and achievement in online learning. A structural model was developed by considering course structure, student–student interaction, instructor presence, student engagement, student satisfaction and achievement as key factors. In order to verify the effectiveness of the developed structural model, we utilized the survey data collected from a total of 250 students enrolled in two asynchronous online c

AIMS: Although many studies have reported an association between serum gamma-glutamyltransferase (GGT) and cardiovascular risk factors, the mechanism of this relationship has not been clarified. METHODS: The medical records of 29,959 subjects (age, median 48, range 14-90 years; 16,706 men, 13,253 women) who visited the Center for Health Promotion at Samsung Medical Center for a medical check-up between January 2001 and December 2003, were investigated. Subjects with hepatic enzyme/GGT concentrat

This study proposes an effective steel frame modular system and evaluates the structural performance of its beam-column connection through experimental and analytical work. The new steel frame modular system utilizes the blind bolts, which allow free access to the structural members of the closed cross-section. In addition, the new modular system is designed such that the strength of its beam members is considerably lower than that of its column members to implement the strong column-weak beam c

Abstract This paper presents an analysis of interacting cracks using a generalized finite element method (GFEM) enriched with so-called global-local functions. In this approach, solutions of local boundary value problems computed in a global-local analysis are used to enrich the global approximation space through the partition of unity framework used in the GFEM. This approach is related to the global-local procedure in the FEM, which is broadly used in industry to analyze fracture mechanics pro

Summary Openings in RC flat‐plate slabs are one of the critical factors that influence the punching shear strength of the slab and determine its thickness in the vicinity of the slab‐column joint. This study experimentally investigates the effects of openings on the punching shear strength of flat‐plate slabs without shear reinforcement. Tests were performed on eight flat‐plate slab specimens considering the layout and number of openings as test variables. The failure characteristics of each spe

The recycling of industrial waste such as bottom ash from furnaces is an important issue in construction industry, since it enables reduction in construction cost and has beneficial effect on the environment. In this study, we have investigated the bond characteristics of steel deformed bars embedded in artificial lightweight aggregate concrete which is manufactured from bottom ash. A pullout test was performed on 144 lightweight aggregate concrete specimens to measure the bond strengths. In thi

Abstract The bond behavior of reinforcing bars is an important issue in the design of reinforced concrete structures and the use of fiber reinforced polymer (FRP) rebars is a promising solution to handle the problems of steel reinforcement corrosion. This study investigates the bond characteristics of carbon and aramid FRP (CFRP and AFRP) bars embedded in normal strength concrete. A pullout test was performed on 63 normal strength concrete specimens reinforced with FRP and steel rebars with diff

In this study, statistical assessment was performed on student engagement in online learning using the k-means clustering algorithm, and their differences in attendance, assignment completion, discussion participation and perceived learning outcome were examined. In the clustering process, three features such as the behavioral, emotional and cognitive aspects of student engagement were considered. Data for this study were collected from undergraduate students who enrolled in an asynchronous onli

This paper presents a case study on the rehabilitation of a fire-damaged structure and describes the results of a site investigation and tests, leading to a plan for the rehabilitation of the structure. The fire took place in the main control room of a thermal power plant and lasted about three hours until it was finally extinguished. To set up a rehabilitation plan for the damaged structure, a visual inspection of the damaged condition was first carried out, which was followed by analysis and o