Kunsan, South Korea
Kunsan, South Korea

Howon University is a university located in Gunsan, South Korea. Wikipedia.

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In this study, numerical analysis using the finite element was carried out for the behavior of steel plates and graphite/epoxy composite laminated plates by low-velocity impact. It verified the validity for the analysis result of the finite element program used in this study, the behavior of plate by weight and velocity changes was verified for each contact load. The composite laminated plate showed about two times more displacement difference than the steel plate by different impact loads. Therefore, it was investigated that the flexible characteristic of composite laminated plate had an effect on the impact absorption. © 2017 Elsevier Ltd


Kim J.-H.,Howon University
Journal of Physical Therapy Science | Year: 2017

[Purpose] While electromyography (EMG) biofeedback has been recently used in diverse therapeutic interventions for stroke patients, research on its effects has been lacking. Most existing studies are confined to functions of the lower extremities, and research on upper extremity functional recovery using EMG biofeedback training is limited. Therefore, this study examined the effects of training using EMG biofeedback on stroke patients’ upper extremity functions. [Subjects and Methods] The subjects of this study included 30 hemiplegia patients whose disease duration was longer than six months. They were randomly divided into a control group (n=15) receiving traditional rehabilitation therapy and an experimental group (n=15) receiving both traditional rehabilitation therapy and training using EMG biofeedback. The program lasted for a total of four weeks. In order to examine the subjects’ functional recovery, the author measured their upper limb function using the Fugl-Meyer Assessment and Manual Function Test, and activities of daily living using the Functional Independence Measure before and after training. [Results] A comparison of the study groups revealed that those in the experimental group experienced greater improvement in upper extremity function after training in all tests compared to the control group; however, there was no significant difference in terms of the activities of daily living between the two groups. The results of this study were as follows. [Conclusion] Thus, stroke patients receiving intensive EMG biofeedback showed more significant upper extremity functional recovery than those who only received traditional rehabilitation therapy. © 2017 The Society of Physical Therapy Science.


Choi Y.,Howon University
International Journal of Applied Engineering Research | Year: 2017

After Lamport first proposed password base authentication scheme, various authentication schemes were studied and remote user authentication schemes using smart cards have been widely used with the development of Internet network technologies. Li et al. analyze Chen et al.’s authentication scheme and found the security vulnerabilities of Chen et al.’s scheme such as forward secrecy and the wrong password login problem, and proposed an a new user password authentication scheme based on smart card. However, Liu et al. point out that Li et al.’s scheme still had security weakness such as man-in-the-middle attack and an insider attack, and then Liu et al. proposed an efficient and secure smart card based password authentication scheme. This paper reviews Liu et al.’s authentication and point out that it has security weakness such as off-line password guessing attack, smart-card loss attack, no perfect forward secrecy, and no anonymity. © Research India Publications.


[Purpose] This study aimed to examine the effects of a combined intervention consisting of massage therapy and transcutaneous electrical nerve stimulation on gastrocnemius muscle fatigue, assessing whether the intervention improved muscle tone, stiffness, and muscle contraction. [Subjects and Methods] The subjects were 20 healthy males in their 20s who were equally divided into a transcutaneous electrical nerve stimulation group and a combined therapy group that received a combination of massage therapy and transcutaneous electrical nerve stimulation. Muscle fatigue was triggered on the gastrocnemius muscle, and the effects of intervention method on muscle tone, stiffness, and muscle contraction were examined over time. [Results] Lateral and medial gastrocnemius muscle tone and stiffness significantly increased and gastrocnemius muscle contraction significantly decreased in each group immediately after fatigue was triggered on the gastrocnemius muscle. There was no difference in the effects of the two intervention methods over time. [Conclusion] This study verified that a combined therapy of massage therapy and transcutaneous electrical nerve stimulation was able to be used effectively in improving muscle tone, stiffness, muscle contraction, thereby reducing gastrocnemius muscle fatigue. © 2017 The Society of Physical Therapy Science. Published by IPEC Inc.


Park H.,Howon University
Key Engineering Materials | Year: 2016

In this study, structural design and analysis of the automobile bonnet is performed. The flax/vinyl ester composite material is applied for structural design. The Vacuum Assisted Resin Transfer Molding(VARTM) manufacturing method is adopted for manufacturing the flax fiber composite bonnet. A series of flax/vinyl ester composite panels are manufactured, and several kinds of specimens cut out from the panels are tested to obtain mechanical performance data. Based on this, preliminary structural design of the automobile bonnet is performed. Finally, this study is to investigate the residual compressive strength of the flax/vinyl ester laminate due to impact damages. Through investigation on compressive strength, design allowable of flax/vinyl ester laminate is determined by the experiment to address design criteria of the composite structure. © 2016 Trans Tech Publications, Switzerland.


Park H.,Howon University
Key Engineering Materials | Year: 2016

This study is to investigate the compressive strength of the carbon/epoxy thick laminate after damage. Through damage tolerance of thick laminate is not standardized test because specimens exceed typical specimen thickness described in the ASTM standard, design allowable of thick laminate shall be determined by the experiment to address design criteria of the structure and incorporate functional capability with damage level. In this study, it is performed the research on damage tolerance of thick laminate adopting aircraft structure. The damage tolerance of thick laminates such as no damage and impact damage is evaluated under compression loading. © (2016) Trans Tech Publications, Switzerland.


Kwon Y.-I.,Howon University
International Journal of Air-Conditioning and Refrigeration | Year: 2016

In the air distribution design of a small theater, either a downward or an upward displacement ventilation is applied generally. The cool air is supplied from openings distributed over the ceiling and extracted beneath the seats for the downward flow and supplied from beneath the seats and extracted from the ceiling for the upward flow system. By the change of air exchange rate (ACH) produced by two divergent ventilation systems inside theater, thermal comfort and ventilation effectiveness around the seats show a different phenomenon. Thereby, it can be seen that the selection of the ventilation system is a significant factor in energy saving. CFD calculations for this study were performed to investigate the effects of various parameters (ADPI and ACE) of air distribution system applied in order to save the cooling energy. This paper focuses mainly on the effect of the varied volume flow rate depending on the ventilation system. The ventilation performances of the downward displacement system are compared quantitatively with the upward displacement system using the concept of the LMA of fresh air. © 2016 World Scientific Publishing Company.


Park H.,Howon University
MATEC Web of Conferences | Year: 2016

In this work, a structural design and analysis on automobile bonnet using natural flax fiber composite is performed. Through the structural analyses using commercial FEM software, it is confirmed that the designed automobile bonnet using natural composite is acceptable for structural safety. And also, the damage is a critical problem in composites during their service in structural applications. Therefore, study on self-healing concept of bonnet structure was performed. © 2016 Owned by the authors, published by EDP Sciences.


Park H.,Howon University
MATEC Web of Conferences | Year: 2016

This paper performed aerodynamic, structural design and analysis of the horizontal axis blade of low noise 1kW class small wind turbine system that can be operated at homes and designed to display excellent performances in low wind velocity regions such as Korea. In terms of the material applied, glass/epoxy that is both economical and excellent in its performance was applied. Structural test was conducted to verify whether the actual movement of the blade designed is consistent with the theoretical analysis result. In addition, structural safety review was performed through the structural analysis of a tower for installing the wind turbine system developed. © 2016 Owned by the authors, published by EDP Sciences.


Park H.,Howon University
Composites Part B: Engineering | Year: 2016

In this study, aerodynamic and structural design of the propeller blade for an advanced turboprop aircraft is performed. Both the vortex theory and the blade element theory are used for aerodynamic design and analysis of the propeller. The propeller must endure various critical loads such as aerodynamic bending, torsion and shear, centrifugal force, vibration, etc. in various flight operations. Therefore the high stiffness and strength carbon/epoxy skin-spar-foam core sandwich type structure is adopted for improvement of lightness. In structural design, the structural design load is selected through investigation of fluid-structure interaction analyses. From investigation of both aerodynamic and structural design results, it is found that the proposed blade has a good aerodynamic performance as well as an allowable structural safety. © 2016 Elsevier Ltd. All rights reserved.

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