• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.72-78
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• 2020

The present study developed shotcrete for fiber-net integrated tunnel support system, which consists of fiber-net support materials including netlike fiber and shotcrete and integration technology between support materials. In addition, in order to evaluate the field applicability of the developed tunnel support system and compare with the performance of steel fiber reinforced shotcrete, mock -up test was conducted on the mock -up structure. The test results show that in the case of shotcrete containing coarse aggregate(S20A5RP10-C), the excessive rebound rate occurred as the secondary shotcrete was dropped during construction due to the degradation in bond performance with fiber-net. Also, in the case of steel fiber reinforced shotcrete, the amount of cast shotcrete fell short of target value due to the fiber ball and the degradation of pumpability. On the other hand, the amount of cast mortar shotcrete(S20A5RP10-M) and the installation position of fiber-net were almost close to the target values, and the lower rebound rate occurred compared to the steel fiber reinforced shotcrete.

• Journal of the Korean earth science society
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• v.41 no.2
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• pp.176-193
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• 2020

The purpose of this study was to explore the effects of science classes on positive science experiences and science learner identity, using smart devices in a future school: C middle school. We conducted a paired t test at the beginning and end of the first school year with first-grade students at the future school to investigate positive experiences with science (Shin et al., 2017). Additionally, first and second-grade students in future schools using smart devices wrote and drew their own depictions in science classes to explore science learner identity, based on a modified analytical framework (Luehmann, 2009). The results show that significant effects on science-related career aspirations, self-concepts, and academic emotions were produced by science classes using smart devices. Science classes using smart devices helped students improve their level of agency and activity, solve problems with immediate and sufficient feedback, and experience meaningful perceptions of the nature of science. On the other hand, if students were immature in terms of their use of smart devices, they felt pressured to participate in the classes. The results of this study can be used as a foundation for designing various classroom contexts for the use of smart devices.

• Therapeutic Science for Rehabilitation
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• v.5 no.1
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• pp.67-75
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• 2016

Objective : This study was examined the effects of task-oriented training therapy after botulinum toxin injection, upper extremity function and activities of daily living for stroke patient. Methods : The subject was a 44 year old male who suffered from hemiplegic patient received a task-oriented training therapy after botulinum toxin injection on involved upper extremity for 30-min sessions 5 times every week during 8 weeks. The scores were obtained before the injection, at 4 weeks, and 8 weeks after the injection. The upper extremity function was assessed using a Manual Function Test and Box and Block Test, and also Modified Barthel Index was applied for evaluation of Activities of Daily Living performance ability. Results : The results of this study show that the subject's In-hand manipulation and dexterity function increase significantly. Also, In activities of daily living, personal hygiene area, feeding area, toilet area, dressing area scores are improved significantly. Conclusion : Through this study, task-oriented training after botulinum toxin injection can improve upper extremity function and Activities of Daily Living performance ability of patient with stroke.

• Journal of Wetlands Research
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• v.18 no.4
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• pp.448-455
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• 2016

Diffuse pollution management in Korea initiated by the Ministry of Environment (MOE) resulted to the construction of pilot facilities termed Best Management Practices (BMPs). Twelve BMPs installed for the diffuse pollution management in the Kyung-An Stream were monitored since 2006. Data on the mass loading, removal efficiency, maintenance activities, etc. were gathered and utilized to conduct the evaluation of long-term performance of BMPs. The financial data such as actual construction, design and maintenance cost were also collected to evaluate the lifecycle cost (LCC) of BMPs. In this study, most of the maintenance activity was focused in the aesthetic maintenance that resulted to the annual maintenance cost of the four BMP types was closely similar ranging from 8,483 $/yr for retention pond to 8,888 $/yr infiltration system. The highest LCC were observed in constructed wetland ($418,324) while vegetated system had the lowest LCC ($210,418). LCC of BMPs was not so high as compared with the conventional treatment facility and sewage treatment plant. On the other hand, the relationship of removal efficiency on unit cost for TSS and TN was significant. This study will be used to design the cost effective BMP for diffuse pollution management and become models for LCC analysis.

• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.227-235
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• 2017

This paper describes some of the challenges for structural design of a mid-story seismic isolated high-rise building, which is located near Tokyo station, completed in 2015. The building is a mixed-use complex and encompasses three volumes: one substructure including basement and lower floors, and a pair of seismic isolated superstructures on the substructure. One is a 136.5m high Main Tower (office use), and the other is a 98.5 m high South Tower (hotel use). The seismic isolation systems are arranged in the $3^{rd}$ floor of the Main Tower and $5^{th}$ floor of the South Tower, so that we call this isolation system as the mid-story seismic isolation. The primary goal of the structural design of this building was to secure high seismic safety against the largest earthquake expected in Tokyo. We adopted optimal seismic isolation equipment simulated by dynamic analysis to minimize building damage. On the other hand, wind-induced vibration of a seismic isolated high-rise building tends to be excited. To reduce the vibration, the following strategies were adopted respectively. In the Main Tower with a large wind receiving area, we adopted a mechanism that locks oil dampers at the isolation level during strong wind. In the South Tower, two tuned mass dampers (TMDs) are installed at the top of the building to control the vibration. In addition, our paper will also report the building performance evaluated for wind and seismic observation after completion of the building. In 2016, an earthquake of seismic intensity 3 (JMA scale) occurred twice in Tokyo. The acceleration reduction rate of the seismic isolation level due to these earthquakes was approximately 30 to 60%. These are also verified by dynamic analysis using observed acceleration data. Also, in April 2016, a strong wind exceeding the speed of 25m/s occurred in Tokyo. On the basis of the record at the strong wind, we confirmed that the locking mechanism of oil damper worked as designed.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.204-214
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• 2015

Depth map upsampling is an approach to increase the spatial resolution of depth maps obtained from a depth camera. Depth map quality is closely related to 3D perception of stereoscopic image, multi-view image and holography. In general, the performance of upsampled depth map is evaluated by PSNR (Peak Signal to Noise Ratio). On the other hand, time-consuming 3D subjective tests requiring human subjects are carried out for examining the 3D perception as well as visual fatigue for 3D contents. Therefore, if an objective metric is closely correlated with a subjective test, the latter can be replaced by the objective metric. For this, this paper proposes a best metric by investigating the relationship between diverse objective metrics and 3D subjective tests. Diverse reference and no-reference metrics are adopted to evaluate the performance of upsampled depth maps. The subjective test is performed based on DSCQS test. From the utilization and analysis of three kinds of correlations, we validated that SSIM and Edge-PSNR can replace the subjective test.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.155-168
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• 2017

This study investigates how elementary students used cognitive-emotional rebuttals in the context of modeling activities, especially on how their emotional and cognitive processes lead them to use rebuttals in terms of epistemic affect. Twenty-five fifth grade elementary students participated in the study as part of their science class. During the course of their sixth periods, students constructed a human respiratory system model through continuous discussion. The research results showed that elementary students used an elaboration-oriented rebuttal, a defence-oriented rebuttal, and a blame-oriented rebuttal in their modeling activity. The elaboration-oriented rebuttal interspersed with negative epistemic affect was used to elaborate on a student's explanation, and a negative epistemic affect was elicited from their cognitive discrepancy. On the other hand, defence-oriented rebuttal and blame-oriented rebuttal entangled with negative epistemic affect were used to defeat the students rather than help rigor evaluation of students' explanation, and the negative epistemic affect was elicited from the other students' undesirable behavior. These results suggest that students' rebuttals can be elicited by epistemic dynamics related to the epistemic affect. The study shows that if negative epistemic affect were elicited from the other students' naive or false explanations, such an emotion is natural in terms of model construction, and the model can be further developed through the acceptance of the elaboration-oriented rebuttals by students' emotion regulation. In addition, we suggest that negative emotions aroused from the worsening of relationships during small group modeling activities are difficult to regulate and can have negative effects on students' cooperative model construction.

• Journal of the Korean GEO-environmental Society
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• v.19 no.2
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• pp.23-35
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• 2018

Recently, ground disasters such as road collapses and cavities have been frequently occurred in Seoul and downtown areas. As a result, studies on the integrated underground space map is underway as a government's solution. On the other hand, the geotechnical information underlying the integrated underground space map has been being built with more than 220 thousands borehole DB informations through the Integrated DB Center of National Geotechnical Information. To build a three-dimensional integrated underground space map based on the geotechnical information, the reliability of the geotechnical information should be verified by analyzing and evaluating the precision of the geotechnical information. Thereby, studies were conducted on the precision verification and evaluation of the constructed geotechnical information. Thereafter, it has been reviewed how to utilize geotechnical information in addition to analyzing the precision of the geotechnical information in order to visualize three dimensions in geotechnical information. As a further step to the practical DB application, a module is suggested in this study to improve the precision of geotechnical information for establishing reliable three dimensional integrated underground space maps based on the previous research results.

• Korean Journal of Poultry Science
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• v.45 no.3
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• pp.175-182
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• 2018

The carcass and meat quality of new native chicken strains (A, C, and D) being developed in the Golden Seed Project for Samgyetang were compared with a commercial native chicken (Hanhyup No. 3, H) and Baeksemi (white semi broiler, W) strains. In total, 250 male chicks were raised under the same feeding and raising conditions for 5 weeks. After slaughter, the carcass weight and percentage yield of parts from each strain were measured and the physicochemical quality traits (general composition, color values, fatty acid composition, and sensory evaluation) of breast muscles were comparatively analyzed. The carcass weight (875.10 g) of the W strain was significantly heavier than that of the other native chicken strains, while that of A strain (537.54 g) was the lowest. The percentage yield of breast meat was also higher in the W strain than in the other strains. The fat content of W strain was higher than that of the other native chicken strains. The new native chicken strains (A, C, D) had higher contents of linoleic acid (C18:2) than the H strain. The A and D strains especially showed relatively high content of arachidonic acid (C20:4), a characteristic fatty acid in native chicken meats. On the other hand, the fatty acid composition of C strain was similar to that of the W strain. This study provides important information on specific quality characteristics than can be used to select new native chicken lines for breeding program.

• Journal of the Korean Wood Science and Technology
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• v.44 no.5
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• pp.776-784
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• 2016

In this study, green Larix kaempferi lumber was heat-treated by using superheated steam (SHS) at a pilot scale and then various physico-mechanical properties of the heat-treated wood were evaluated and compared with the properties of conventional hot air (HA) heat-treated wood. Decay resistance of brown rot fungi and compressive strength parallel to the grain of the SHS heat-treated wood without occurrence of drying check from green lumber were increased. On the other hand, density, equilibrium moisture content, shrinkage, and bending strength of the SHS heat-treated wood were lower than those of the conventional HA heat-treated wood. Because heat transfer and thermal hydrolysis of SHS heat treatment was accelerated by a large amount of water, the effect of SHS heat treatment on the physico-mechanical properties was higher than that of HA heat treatment at the similar conditions of temperature and time. From the results of this study, because green lumber can be heat-treated without occurrence of cracks or checks by using SHS and similar heat treatment effect on the physico-mechanical properties of wood can be produced despite a low temperature or short time of heat treatment, it is expected that heat time and energy consumption could be reduced by using SHS.