• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.493-501
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• 2016

Objective: This study analyzes the effect of angle conditions of rehabilitation equipment used for supporting hemiplegic patients on their rehabilitation training for standing action. The study was performed by adjusting the rear angle of seat inclination through a motion analysis. Background: Owing to a loss of muscle rigidity and degradation of muscle control ability, hemiplegic stroke patients suffer from asymmetrical posture, abnormal body balance, and degraded balance abilities due to poor weight-shifting capacity. The ability to shift and maintain one's weight is extremely essential for mobility, which plays an important role in our daily life. Thus, to improve patients' ability to maintain weight evenly and move normally, they need to undergo orthostatic and ambulatory training. Method: Using a motion analysis system, knee movements on both hemiplegic side and non-hemiplegic side were measured and analyzed in five angles ($0^{\circ}$, $10^{\circ}$, $30^{\circ}$, $50^{\circ}$, $70^{\circ}$) while supported by the sit-to-stand rehabilitation equipment. Results: The knee movements on both sides increased as the angle increased in angle support interval to support a hemiplegic patient's standing up position. In standing up interval, a hemiplegic patient's knee movement deviations on both sides decreased, and the movement differences between hemiplegic and non-hemiplegic legs also decreased as the angle increased. Conclusion: The results of this study showed that the rehabilitation effectiveness increases as the angle increases, leading to a balanced standing posture through the decrease of movement difference between hemiplegic and non-hemiplegic sides and an improved standing up ability through the increase of knee movement on both sides. However, angles higher than $50^{\circ}$ didn't provide a significant effect. Therefore, a support angle under $50^{\circ}$ was proposed in this study. Application: The results of this study are expected to be applicable to the design of sit-to-stand support equipment to improve the effectiveness of the rehabilitation process of hemiplegic patients.

• Journal of Digital Convergence
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• v.18 no.9
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• pp.317-322
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• 2020

The purpose of this study is to lay the groundwork for the operation method for correctly operating remote lectures at universities. Among the universities that started non-face-to-face classes due to 'COVID-19', college students and graduate students from some universities who conducted remote lectures through Cisco's Webex meeting were studied on how to operate the remote lecture platform. First, the requirements for lectures for remote lectures were established through the literature survey, and effective operation measures were proposed through the survey. The research method was conducted on a total of 45 college and graduate students from April 21 to May 15, 2020. The results of the study showed that the operation plan for the basic and meeting elements. Based on this study, we expect it to be used in disaster situations or classes that may occur after COVID-19. In the future, the usability evaluation of the remote class platform and the direction in which the domestic remote lecture platform should move should be presented.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.841-844
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• 2008

Non-refining fly ash and bottom ash, the byproducts generated from the coal-fired power stations, have usually been disposed of in onshore ash disposal sites. With an increase of power consumption due to industrial development, the generation of coal ash has been growing tremendously. Current insufficiency of disposal sites and environmental concerns over newly-built disposal sites have also led a growing need to utilize the coal ash. Accordingly, this paper compares and analyzes the fundamental properties of the coal ash collected from each disposal sites in order to increase the usability of the coal ash generated from coal-fired power stations. The results of the study indicate that coal ash shall be separately applied by the properties for each intended use as the ash greatly differs in its properties depending on the site of disposal. In particular, it is shown that the overall evaluation on the ash shall be necessary as the quality might be varied by the change of absorptance when applied as an aggregate for concrete. From the examination on the salt content, it has been observed that the ash can be applied as an aggregate for concrete only after more than 3 times of washing process.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.145-147
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• 2018

As mobile devices increase use, users are forced to recognize and navigate their own location and virtual space within a given small display. Unlike trains and buses, this study aims to select a space inside a subway train that is difficult to transfer location information to and suggest an interface to reduce cognitive differences to users. First, observe the actual environment and then derive the empirical factors. Second, by using Metapo which is an act of understanding or experiencing specific targets that are not familiar with familiar objects, the interface is designed according to the UX principle after converting the experience element into metapo. Finally, usability will be assessed through user experience evaluation and problem elicited and supplemented in future studies. This study expects the use of spatial interfaces to be increased and applied as a variety of services by using metaphors through experience elements to help users easily recognize their location within the mobile interface.

• Computers and Concrete
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• v.22 no.2
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• pp.227-237
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• 2018

Today, the modeling of concrete as a material within finite element simulations is predominantly done through nonlinear material models of concrete. In current sophisticated computational systems, there are a number of complex concrete material models which are based on theory of plasticity, damage mechanics, linear or nonlinear fracture mechanics or combinations of those theories. These models often include very complex constitutive relations which are suitable for the modeling of practically any continuum mechanics tasks. However, the usability of these models is very often limited by their parameters, whose values must be defined for the proper realization of appropriate constitutive relations. Determination of the material parameter values is very complicated in most material models. This is mainly due to the non-physical nature of most parameters, and also the large number of them that are frequently involved. In such cases, the designer cannot make practical use of the models without having to employ the complex inverse parameter identification process. In continuum mechanics, however, there are also constitutive relations that require the definition of a relatively small number of parameters which are predominantly of a physical nature and which describe the behavior of concrete very well within a particular task. This paper presents an example of such constitutive relations which have the potential for implementation and application in finite element systems. Specifically, constitutive relations for modeling the plane stress state of concrete are presented and subsequently tested and evaluated in this paper. The relations are based on the incremental theory of elastic strain-hardening plasticity in which a non-associated flow rule is used. The calculation result for the case of concrete under uniaxial compression is compared with the experimental data for the purpose of the validation of the constitutive relations used.

• Journal of Convergence for Information Technology
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• v.10 no.1
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• pp.139-148
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• 2020

As the internet and computer technology are developed, there is a need for service of traditional culture that can effectively search and create culture, history, and tradition-related materials in online contents. In this paper, we developed an RDF-based ontology retrieval service platform and verified usability and validity. This platform is divided into triple search, keyword search, network graph search, story search and management, curation management module. Based on this, the search results can be visualized based on the relationship between data, network graph search and story search can be used to easily understand the relationship between the keywords. An platform evaluation was conducted for verification, and it was evaluated that an intelligent search that can easily identify the relationship between information and shorten the analysis and search time than the existing search function.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.369-374
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• 2017

The object of this study is to offer domestic and overseas travel informations efficiently for domestic tourists growing far beyond 15 million even now through user centered interface more convenient and accurate. In a method of research, 100 people were surveyed after recasting of evaluation questionnaire about UI design using 5-point Likert and nominal scale and additionally, the in-depth interviews were given to 10 people who use travel application frequently. In consequence, this interview revealed where users feel convenience and difficulty and want improvement of usability, information accuracy, etc. Finally, this study has a meaning to suggest new UI prototypes and various guideline about additional UI design on the basis of surveyed parts.

• Journal of the Korea Computer Graphics Society
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• v.21 no.4
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• pp.19-26
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• 2015

This paper presents a method for optimizing a carrying pose of human body for a given object. The inputs are articulated human body model and and arbitrary-shaped object. We assume that the object is big and heavy, so that both arms should be used to carry it. Unlike small and light objects, big and heaby objects can be hold by only a small range of body poses while keeping a physical statbility. We first introduce an algorithm that evaluates a physical stability of a given human body pose and object state (position and orientation). Then, we define a configuration space and search the space for the most stable carrying pose by using the evaluation algorithm. Finally, to demonstrate the usability of our method, we present the results which each is experimented with different shaped objects and additional user conditions.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.2
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• pp.121-130
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• 2012

This paper proposes an intuitive real-time robot control system using human body movement. Recently, it has been developed that motion generation for humanoid robots with reflecting human body movement, which is measured by a motion capture. However, in the existing studies about robot control system by human body movement, the detailed structure information of a robot, for example, degrees of freedom, the range of motion and forms, must be examined in order to calculate inverse kinematics. In this study, we have proposed Associative Motion Generation as humanoid robot motion generation method which does not need the detailed structure information. The associative motion generation system is composed of two neural networks: nonlinear principal component analysis and Jordan recurrent neural network, and the associative motion is generated with the following three steps. First, the system learns the correspondence relationship between an indication and a motion using training data. Second, associative values are extracted for associating a new motion from an unfamiliar indication using nonlinear principal component analysis. Last, the robot generates a new motion through calculation by Jordan recurrent neural network using the associative values. In this paper, we propose a real-time humanoid robot control system based on Associative Motion Generation, that enables user to control motion intuitively by human body movement. Through the task processing and subjective evaluation experiments, we confirmed the effective usability and affective evaluations of the proposed system.

• Science of Emotion and Sensibility
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• v.17 no.3
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• pp.117-128
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• 2014

As the main cause of car accidents is driver distraction, HUD utilization is important to boost drivers' front-observing. Recently, As HUD includes a variety of contents products have appeared on market, the possibility increases cognitive load while driving. The purpose of this study is that currently being used HUD contents how much affect drivers while driving. To investigate about it, the experiment is examined cognitive aspect with utilization aspect of different gender and illuminance environment. The study provides, in accordance with the internal and external illuminance, the visibility make a difference. The gap between the internal and external illuminance is higher, the visibility is better. Also, this study confirms that HUD's awareness of contents depends on driving information. Drivers concentrate more on higher related driving contents than lower ones.