• Journal of the Korean Society of Industry Convergence
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• v.23 no.2_2
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• pp.343-349
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• 2020

As global warming accelerates due to global climate change, the International Maritime Organization(IMO) has set up Emission Control Area(ECA) and encourages the use of Liquefied Natural Gas(LNG). For this reason, as the demand for LNG increases, the demand and research of related equipment also increases. In this study, one of them, the vent mast for the discharge of LNG was studied. In general, vent mast receives various loads such as wind load, earthquake load and dead load during operation. Accordingly, consideration of these loads is essential for structural design and safety evaluation of the vent mast. In this study, the structural safety of the vent mast is evaluated by performing finite element analysis. As a result, the structural safety evaluation results were analyzed based on the database of materials of the vent mast, and the stress level was analyzed to provide a design guide.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1515-1520
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• 2011

Structural analysis and evaluation for the 300ton Goliath Crane were conducted with an FEM tool. The Golliath Crane has a 300 ton hoisting weight, a 110 m span and a 50 m lift. All loads such as the self weight, crane traveling load, trolley traveling load, wind load, and earthquake force, etc., that are indicat in the reference standards, were inputted as various severe conditions affecting the crane. The deformation and equivalent stress (von Mises stress) were evaluated for the crane structures.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.1
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• pp.39-58
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• 2004

It is very important that predict the inelastic seismic behavior exactly for seismic performance evaluation of a building in the performance based seismic design. Evaluation method of seismic performance based on the pushover analysis reflected in PBSE was developed by some researchers. For the evaluation of inelastic global and local seismic responses by pushover analysis exactly. lateral load distribution should be adjusted and reflected the dynamic characteristics of structural system and various seismic ground motions. And performance point should be determined based on the evaluation of reasonable deformation capacity of a building more exactly. An effective method based on the improved the adaptive lateral load distribution and the equivalent responses of a multistory building is proposed in this study to efficiently estimate the accurate inelastic seismic responses. The proposed method can be used to evaluate the seismic performance for the global inelastic behavior of a building and to accurately estimate its local inelastic seismic responses. In order to demonstrate the accuracy and validity of this method, inelastic seismic responses estimated by the proposed method are compared with those obtained from other analytical methods.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.1-12
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• 2003

Instead of sensory evaluation, we designed an evaluation method of the setting function of hairstyling products, based on an original theory focusing on changes in bending stress observed when a load with continuous bending is applied to human hair. Specifically, we developed a device to measure bending stress to quickly and objectively evaluate the condition of human hair, particularly its dynamic properties such as the setting function, following the application of hairstyling products. This device generates a load with continuous bending while applying a pendulum motion to a hair tress, one end of which is anchored. The setting function and holding power of resins of various molecular weight and ionic properties were evaluated using this device. The results demonstrated a close correlation with those obtained by experts' sensory evaluation. The evaluation results of bending stress and holding rate confirmed that the combined use of two different resins could improve the function of setting preparations. Evaluation using this device was able to substitute for sensory evaluation, and offers quick objective evaluation and detection of changes in the holding power of hairstyling products over time. We conclude that evaluation using this device is a promising new method.

• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.394-405
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• 2020

To assess the station-keeping performance of floating structures in the Arctic region, the ice load should be considered along with other environmental loads induced by waves, wind, and currents. However, present methods for performance evaluation in the time domain are not effective in terms of time and cost. An ice load generation module is proposed based on the experimental data measured at the KRISO ice model basin. The developed module was applied to a time domain simulation. Using the results of a captive model test conducted in multiple directions, the statistical characteristics of ice loads were analyzed and processed so that an ice load corresponding to an arbitrary angle of the structure could be generated. The developed module is connected to commercial dynamic analysis software (OrcaFlex) as an external force input. Station-keeping simulation in the time domain was conducted for the same floating structure used in the model test. The mooring system was modeled and included to reflect the designed operation scenario. Simulation results show the effectiveness of the proposed ice generation module and its application to station-keeping performance evaluation. Considering the generated ice load, the designed structure can maintain a heading angle relative to ice up to 4°. Station-keeping performance is enhanced as the heading angle conforms to the drift direction. It is expected that the developed module will be used as a platform to verify station-keeping algorithms for Arctic floating structures with a dynamic positioning system.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.89-94
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• 2020

This study attempted to investigate cognitive load, vividness, and cybersickness in nursing students, in the last year of nursing college, who used a 360-degree video content for studying intravenous fluid infusion, one of the core fundamental nursing skills. The aim was to determine the correlation between the variables, and to decide whether the 360-degree video content can be used as an effective supplementary educational material in the regular curricula. This study, a descriptive research, was conducted from October 31, 2019 to November 14, 2019. The participants in this study were 64 students in the 4th year of nursing college at a university located in B City, South Korea. They were instructed to watch a 360-degree video content for intravenous infusion using a Samsung Head Mounted Display (HMD) while ensuring the safety of the students. The results showed that the scores, out of 7 points, for material design, self-evaluation, and physical effort for cognitive load in nursing students were 5.93±0.71, 5.92±0.71, and 5.64±0.74 points, respectively. In addition, the scores, out of 7 points, for mental effort and task difficulty were 2.55±1.08 and 1.94±0.75 points, respectively, and the scores for vividness and cybersickness in the participants were 5.82±0.84, and 2.57±0.98 points, respectively. Physical effort, self-evaluation, and material design for cognitive load in the participants were positively correlated with vividness (r=.379, r=.458, r=.507). In addition, mental effort for cognitive load was positively correlated with cybersickness (r=.684), whereas self-evaluation and material design were negatively correlated with cybersickness (r=-.388, r=-.343). Based on the results of this study, we believe that the 360-degree video content for intravenous fluid infusion can be used as an educational medium in regular and non-regular curricula. In addition, future studies are needed to specifically develop and verify teaching and learning methods on how to apply 360-degree video contents..

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.4
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• pp.67-74
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• 2016

Load Duration Curve (LDC) can be used as a method for load management of point and non-point pollution source because the LDC easily assesses the water quality corresponding to hydrological changes in a watershed. Recently, the application of LDC to total pollution load management is a growing interest in Korea. In this regard, A desktop-based LDC assessment system was developed in this study to provide convenience to users in water quality evaluation. The developed system can simply produce the LDC by using streamflow and water quality data involved in its database. Also, The system can quantitatively inform the success or failure of the achievement for a target water quality at monthly scale. Furthermore, seasonal water quality and point/non-point pollution load in a watershed can be estimated by this system. We expect that the developed system will contribute to establish local and national policies regarding water management and total pollution load management because of its advantages such as the pollution tracking investigation and the analysis of water quality and pollution loading amount in an ungauged watershed.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1391-1415
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• 2016

Limit load of pressure bearing structures was reviewed in this article. By means of the finite element analysis, limit load of pressurized cylinder with nozzle was taken as an example. Stress classification method and Elastic-plastic finite element analysis combining with limit load determination methods were used to determine limit load of cylinder with nozzle. Comparison of limit load determined by different methods, the results indicated that limit load determined by linearization method was the smallest. Limit load determined by twice elastic slope criterion was the nearest than experimental results. Elastic-plastic finite element analysis had comparably computational precision, but required time consuming. And then the requirements of computer processing and storage capacity by power system became higher and higher. Most of criteria for limit load estimation included any human factors based on a certain substantive characteristics of experimental results. The reasonable criterion should be objective and operational.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.291-294
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• 2003

Ball indentation tests have been used to estimate the mechanical properties of materials by some investigators. In this study, load-depth curves from ball indentation tests have been analysed using the geometric conditions of ball indentation. Series of numerical calculations and experimental results showed that those curves could be simplified by linear functions. After linearizing the indentation curves, the estimation process of the flow properties became straight forward and the scatter of results could be drastically reduced.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.559-560
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• 2009

This Study was performed to evaluate about load bearing capacity of PSC Girder with unbonded 2nd tendon. The evaluation was performed static loading test, dynamic loading test and structural analysis.