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Search Results: 1 - 10 of 315283 matches for " Hee J. Kim "
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Finite Element Analysis with Paraxial & Viscous Boundary Conditions for Elastic Wave Propagation  [PDF]
Hee Seok Kim
Engineering (ENG) , 2012, DOI: 10.4236/eng.2012.412107
Abstract: In this study, two studies are performed. One is to apply paraxial boundary conditions which are local boundary conditions based on paraxial approximations of the one-way wave equations to finite element analysis. To do this, a penalty functional is proposed and the existence and uniqueness of the extremum of the proposed functional is demonstrated. The other is to improve the capacity of viscous boundary conditions using dashpots. To do this, customary viscous boundary conditions are modified to maximize the efficiency according to angles of incidence and materials. For the numerical analysis of elasticity with paraxial boundary conditions and the modified viscous boundary conditions, the coding of the finite element models is implemented, and the efficiency of those boundary conditions is investigated.
Journal of Building Construction and Planning Research: A New Platform for Building Researchers  [PDF]
Gwang-Hee Kim
Journal of Building Construction and Planning Research (JBCPR) , 2013, DOI: 10.4236/jbcpr.2013.12004
Abstract: Journal of Building Construction and Planning Research: A New Platform for Building Researchers
A Study on the Characteristics for the Ground Vibration Due to the Travelling Tilting Train  [PDF]
Hee Seok Kim
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.59087
Abstract:

The development of the tilting train can contribute to solve the economic burden and enhance the transportation means of areas that did not share the benefits of the high speed railway. But the dynamic behavior caused by the interaction between the train and the track as well as the environmental vibrations along the railway should be evaluated to secure the safety of the train and riding comfort. In this paper a study on the characteristics for ground vibration due to the tilting train travelling in the conventional line are carried out. The transmitted load into the ground is computed through a study on the interrelation between the tilting car and the line. This load is applied into the numerical model which is one for the analysis of ground vibration due to the travelling tilting car. The far fields on the numerical model are formed by the absorbing boundary using dashpot, one of the most widely used absorbing boundary in finite element analysis. Using this numerical model, the analysis of the ground vibration characteristics caused by travelling tilting car is performed. From the analysis, it is shown that the transferred load due to the tilting train is larger than that of the conventional train.

A Study on the Performance of Absorbing Boundaries Using Dashpot  [PDF]
Hee Seok Kim
Engineering (ENG) , 2014, DOI: 10.4236/eng.2014.610060
Abstract: In this paper an analytical study is carried out to examine the effectiveness of absorbing boundaries using dashpot. Validity of the absorbing boundary conditions suggested by Lysmer-Kuhle- meyer and White et al. is investigated by adopting the solution of Miller and Pursey. The Miller and Pursey’s problem is then numerically simulated using the finite element method. The absorption ratios are calculated by comparing the displacements at the absorbing boundary to those at the free field without the absorbing boundary. The numerical verification is carried out through comparison of displacement at the boundary.
A Study on the Characteristics and the Effective Reduction Methods for the Ground Vibration Due to the Travelling Tilting Train  [PDF]
Hee Seok Kim
Engineering (ENG) , 2014, DOI: 10.4236/eng.2014.64024
Abstract:

In this paper, a study on the characteristics and the reduction methods of ground vibration due to the tilting train travelling in the conventional line is carried out. The load transmitted into the ground is computed considering the interaction between the tilting car and the line. This load is then applied in the numerical model for the analysis of ground vibration due to the travelling tilting car. The far-fields of the numerical model are modeled using the dashpot, as one of the most widely used absorbing boundaries in finite element analysis. Using this numerical model, the analysis of the ground vibration characteristics caused by the travelling tilting car and the analysis of the blocking effect of the ground vibration by wave barriers are performed. From the numerical analysis, it is shown that the blocking effect of the trench and the barrier filled with soft material is more effective than that of the barrier filled with hard material.

The effect of self-observation on the self-directed learning ability of nursing students: An experimental study  [PDF]
Dong-Hee Kim
Open Journal of Nursing (OJN) , 2013, DOI: 10.4236/ojn.2013.38070
Abstract:

Background: Patients expect nurses to be both technically competent and psychosocially skilled. Enhancing the quality of patient care and patient safety in healthcare settings has increased, resulting in limited opportunities for students to practice clinical skills in healthcare settings. Achieving competence in these skills is viewed as an essential task to be completed during the school curriculum. Objective: The purpose of this study was to evaluate the use of self-observation through cellular recordings as an adjunct to the clinical skills teaching of a blood sugar test to undergraduate nursing. Design: The research design consisted of pre- and post-test consecutive experimental design through a control group. Settings: This study targeted nursing students enrolled in baccalaureate programs running in Korea. Participant: The participants were 64 students including 34 for the experimental group and 30 for the control group. Methods: Those in the control group received standard teaching methods using lectures and skills classes and facilitated the use of self-study methods. Those in the experimental group received standard teaching using lectures and skills classes and facilitated use of cell phone recorded self-observation. The self-confidence of practicing a blood sugar test, satisfaction with the learning method, self-study participation, level of interest in nursing practice, and self-directed learning ability were measured using questionnaires. Results: Significant between-groups differences were detected in self-confidence of practicing a blood sugar test (t = 2.067, p = 0.043), satisfaction with the learning method (t = 2.818, p = 0.044), self-study participation (

Measuring the Effectiveness of Safety Incentives in Construction Sites in Korea  [PDF]
Gwang-Hee Kim
Journal of Building Construction and Planning Research (JBCPR) , 2018, DOI: 10.4236/jbcpr.2018.64018
Abstract: The purpose of this study is to investigate the effect of motivation factors that actively induce construction workers participate in safety prevention activities and to investigate the effect of incentive program as motivation factor by conducting questionnaire survey. The survey was conducted for construction workers from September, 2017 to October, 2018, and the number of respondents was 256. The results of this study are that the factor of the greatest role in encouraging workers to voluntarily participate in accident prevention activities is management factors and that the introduction of new management methods such as safety incentives to reduce safety accidents is necessary. These results indicate that the accident prevention facilities and safety education and training have their limitations. Therefore, it is necessary to thoroughly reconsider what has already been done, and to find more innovative methods to reduce construction accidents.
Human Neural Stem Cells Genetically Modified to Overexpress Akt1 Provide Neuroprotection and Functional Improvement in Mouse Stroke Model
Hong J. Lee, Mi K. Kim, Hee J. Kim, Seung U. Kim
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0005586
Abstract: In a previous study, we have shown that human neural stem cells (hNSCs) transplanted in brain of mouse intracerebral hemorrhage (ICH) stroke model selectively migrate to the ICH lesion and induce behavioral recovery. However, low survival rate of grafted hNSCs in the brain precludes long-term therapeutic effect. We hypothesized that hNSCs overexpressing Akt1 transplanted into the lesion site could provide long-term improved survival of hNSCs, and behavioral recovery in mouse ICH model. F3 hNSC was genetically modified with a mouse Akt1 gene using a retroviral vector. F3 hNSCs expressing Akt1 were found to be highly resistant to H2O2-induced cytotoxicity in vitro. Following transplantation in ICH mouse brain, F3.Akt1 hNSCs induced behavioral improvement and significantly increased cell survival (50–100% increase) at 2 and 8 weeks post-transplantation as compared to parental F3 hNSCs. Brain transplantation of hNSCs overexpressing Akt1 in ICH animals provided functional recovery, and survival and differentiation of grafted hNSCs. These results indicate that the F3.Akt1 human NSCs should be a great value as a cellular source for the cellular therapy in animal models of human neurological disorders including ICH.
The Hypergroupoid Semigroups as Generalizations of the Groupoid Semigroups
Jeong Soon Han,Hee Sik Kim,J. Neggers
Journal of Applied Mathematics , 2012, DOI: 10.1155/2012/717698
Abstract: We introduce the notion of hypergroupoids (Bin(),□), and show that (Bin(),□) is a super-semigroup of the semigroup (Bin(),□) via the identification ?{}. We prove that (Bin?(),?,[?]) is a -algebra, and obtain several properties of (Bin?(),□).
Generalized Fibonacci sequences in groupoids
Hee S Kim, J Neggers and Keum S So
Advances in Difference Equations , 2013, DOI: 10.1186/1687-1847-2013-26
Abstract: MSC: 11B39, 20N02, 06F35.
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