• Korean Journal of Construction Engineering and Management
• /
• v.16 no.5
• /
• pp.31-41
• /
• 2015

The telecommunication industry has been considered as a national fundamental infrastructure. However, due to the rapid evolution of technology and the change of industry market conditions, the telecommunication infrastructure needs no more huge space for facility and it leads its use to the mixed-use development based on private investment. This study intends to examine the financial feasibility of the development project for the optimal alternative use of telecommunication facility purpose site as a case study based on two types: contributed acceptance and multi-level designation. The NPA and IRR has been analyzed by the simulation of stochastic variables including rent price and its variation rate, vacancy rate, construction cost, capitalization rate and discount rate. The research finding indicates that the two types of development are satisfied with the financial feasibility and it is noteworthy that the rent price turns out to be the most critical factor for the project. Accordingly, it is expected that these research finding can be applied for providing the solid cases of financial feasibility analysis for the development project in limited use of telecommunication facility purpose site.

• Journal of Environmental Science International
• /
• v.26 no.5
• /
• pp.573-584
• /
• 2017

In order to simulate a typhoon precisely, the satellite observation data has been assimilated using WRF (Weather Research and Forecasting model) three-Dimensional Variational (3DVAR) data assimilation system. The observation data used in 3DVAR was GPS Radio Occultation (GPS-RO) data which is loaded on Low-Earth Orbit (LEO) satellite. The refractivity of Earth is deduced by temperature, pressure, and water vapor. GPS-RO data can be obtained with this refractivity when the satellite passes the limb position with respect to its original orbit. In this paper, two typhoon cases were simulated to examine the characteristics of data assimilation. One had been occurred in the Western Pacific from 16 to 25 October, 2015, and the other had affected Korean Peninsula from 22 to 29 August, 2012. In the simulation results, the typhoon track between background (BGR) and assimilation (3DV) run were significantly different when the track appeared to be rapidly change. The surface wind speed showed large difference for the long forecasting time because the GPS-RO data contained much information in the upper level, and it took a time to impact on the surface wind. Along with the modified typhoon track, the differences in the horizontal distribution of accumulated rain rate was remarkable with the range of -600~500 mm. During 7 days, we estimated the characteristics between daily assimilated simulation (3DV) and initial time assimilation (3DV_7). Because 3DV_7 demonstrated the accurate track of typhoon and its meteorological variables, the differences in two experiments have found to be insignificant. Using observed rain rate data at 79 surface observatories, the statistical analysis has been carried on for the evaluation of quantitative improvement. Although all experiments showed underestimated rain amount because of low model resolution (27 km), the reduced Mean Bias and Root-Mean-Square Error were found to be 2.92 mm and 4.53 mm, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.17 no.2
• /
• pp.130-137
• /
• 2012

The underwater glider using conception of Lagrangian method, is a new observation platform to understand the properties of the ocean vertically. In 2011 March, KORDI made a first successful autonomous trip from Hupo to west coast of Uleungdo piloting Littoral Glider of Alaska Native Technology LLC. The journey considered many environmental variables and route vigilantly selected, the glider covered 177 km horizontally and took approximately 6 days (153 hours). Despite the existence of 1 kt eddy current, Sound velocity sampling was conducted from 5 meters and reaching maximum of 200 meters depth at each dive. It successfully collected sound velocity and temperature profile at every 5 seconds totaling up to 1408 profiles using SVT&P sensor. During the flight it was also a mission to check the diverse modes of the glider i.e. spiral, waypoints, heading, drift and hover could function without a defect in a given situation. These modes were thoroughly monitored and it could be considered that the glider handled it well during the flight. As a result of this test flight, it was evident that the given underwater glider could operate under 2kt current environment with users defined heading and depth, also with the payload up to 5 kg without changing internal buoyancy.

• Archives of Craniofacial Surgery
• /
• v.21 no.5
• /
• pp.276-282
• /
• 2020

Background: Orbital fractures are the most common pediatric facial fractures. Treatment is conservative due to the anatomical differences that make children more resilient to severe displacement or orbital volume change than adults. Although rarely, extensive fractures may result in enophthalmos, causing cosmetic problems. We aimed to establish criteria for extensive fractures that may result in enophthalmos. Methods: We retrospectively reviewed the charts of patients aged 0-15 years diagnosed with orbital fractures in our hospital from January 2010 to February 2019. Computed tomography images were used to classify the fractures into linear, trapdoor, and open-door types, and to estimate the defect size. Data on enophthalmos severity (Hertel exophthalmometry results) and fracture pattern and size at the time of injury were obtained from patients who did not undergo surgery during the follow-up and were used to identify the surgical indications for pediatric orbital fractures. Results: A total of 305 pediatric patients with pure orbital fractures were included-257 males (84.3%), 48 females (15.7%); mean age, 12.01±2.99 years. The defect size (p=0.002) and fracture type (p=0.017) were identified as the variables affecting the enophthalmometric difference between the eyes of non-operated patients. In the linear regression analysis, the variable affecting the fracture size was open-door type fracture (p<0.001). Pearson's correlation analysis demonstrated a positive correlation between the enophthalmometric difference and the bony defect size (p=0.003). Using receiver operating characteristic curve analysis, a cutoff value of 1.81 ㎠ was obtained (sensitivity, 0.543; specificity, 0.724; p=0.002). Conclusion: The incidence of enophthalmos in pediatric pure orbital fractures was found to increase with fracture size, with an even higher incidence when open-door type fracture was a cofactor. In clinical settings, pediatric orbital fractures larger than 1.81 ㎠ may be considered as extensive fractures that can result in enophthalmos and consequent cosmetic problems.

• Journal of KIISE:Software and Applications
• /
• v.34 no.10
• /
• pp.900-909
• /
• 2007

This paper describes an experiment on the evaluation of human sensibility by monitoring responses to changes In the frequency and amplitude of a tactile display system. Preliminary tasks were performed to obtain effective adjectives concerning texture perception. The number of collected adjectives was originally 33. This number of adjectives was reduced to 14 by a suitability survey that asked whether an adjective is suitable for expressing a texture feeling. Finally after performing a semantic similarity evaluation, the number of adjectives was further reduced to ten and these ten were used in the main experiment. In the main experiment, selected sandpaper types and 15 selected combinations of frequencies and amplitudes of a tactile display were utilized to quantitatively evaluate the ten adjectives using a bipolar seven-point scale. The data show that a relationship exists between the independent variables(frequency, amplitude, and grit site) and the dependent variable(perceived texture). That is, the change of frequency and amplitude is directly related to perceived roughness or essential elements of human tactile sensitivity found in the preliminary experiment.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.1
• /
• pp.43-53
• /
• 2020

The purpose of this study is to reduce the anxiety factors of fires by following evacuation tips in case of fire in an apartment household. This study analyzed the moderating effects of the control offices' competence in control on safety awareness and fire response. The study results were as follows. First, the residents and control staff's safety awareness had a positive effect on the fire response performance. This indicates that the higher the residents and control staff's safety awareness level, the higher the fire responsive performance. Second, the higher the control offices' control competence level, the better the apartment residents and control staff's safety awareness had a positive effect on the fire response performance. These results indicate that the higher the control office heads' leadership, the higher the apartment residents' housing satisfaction and that the more communicative the control office heads' attitude toward the residents, the better their attitude had a positive effect on the fire response performance. Lastly, the control offices' control competence was analyzed to have a moderating effects on the effect of the apartment residents and control staff's safety awareness level on the fire response performance. These results showed that the change in the model's R² value showed an increasing trend in stages as the value increased more in the stage 2 than the stage 1 and even more in the stage 3 with the interaction terms of the moderating variables added. For this reason, the control offices' control competence which was a moderating variable was analyzed to have a moderating effect on the effect of residents and control staff's safety awareness level on the fire response performance.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.11
• /
• pp.255-264
• /
• 2013

This research was conducted to analyze parents' attitudes on the issues related to the Smart Education Initiative Korea. The questions included the usefulness of major digital tools for educational purposes, knowledge on the Smart Education, necessity for better educational methods, and Bring Your Own Devices (BYOD) policy. A total of 432 response cases from the parents were analyzed considering the parents' age, academic level, and income. As a result, parents regarded desktop PCs as more effective tools for learning when compared to tablet PCs. Meanwhile, mobile devices and SNSs were hardly considered as instructional tools. Second, familarity and understanding of the Smart Education were proportional to household income and mothers' education levels. Third, parents needed for the change in educational methods and agreed with the importance of students' self-regulated learning, collaboration, inquiry ability and creativity. Fourth, regarding BYOD, parents were willing to buy devices with a reasonable price. In conclusion, it is required to reflect the results of the study when implementing the Smart Education throughout the nation.

• Journal of the Korea Convergence Society
• /
• v.12 no.9
• /
• pp.113-120
• /
• 2021

As a result, the interaction between personal motivation and class type is not significant. On the other hand, the interaction between social motivation and class type is significant and overall online class increases engagement with educational issues. In particular, the group with low social motivation showed greater change than the group with high social motivation, so online education seems to be more effective in the group with low social motivation. It means that by stimulating students' social motivation rather than personal motivation, the effectiveness of online education can be enhanced, and it can lead to education outcomes - behavioral changes and attitudes of learners. In order to revitalize social motivation in the intensely personal space of online, it is necessary to activate social communication methods such as SNS, and development of interpersonal issues and learning materials would be more efficient. In order to derive more specific results, it is necessary to measure the level of prior knowledge and involvement of the participants in class, and to comprehensively investigate and analyze the state of learners before and after class through more variables. Finally, in order to increase the reliability of the research results, it is necessary to clearly prove it through the establishment of a structural model.

• 한국노년학
• /
• v.37 no.1
• /
• pp.15-32
• /
• 2017

The current study aims to identify the heterogeneous changes of functional disabilities in old age rather than to identify an average longitudinal pattern and to explore the effect of health status and social status as risk factors in functional disability trajectories. The sample consisted of a representative sample of community dwellers aged 65 and older from the Korean Longitudinal Study of Ageing (2006 - 2012) was the focus of the study. Latent Class Growth Analysis was used to identify the functional disability trajectory groups. Variables regarding health status and social status changes by class were identified using multinomial logistic regression. The results showed various change patterns in functional disability, which include independent (78%), stable high (4.4%), steeply increasing (7.1%), slightly increasing (5.5%), and moderate to low (4.7%). Aggravation in depressive symptoms and cognitive functions as well as decline in social participations and social engagements were significant predictors of membership in increasing group of functional disability. The findings provide important initial empirical information to target clinical practice and have implications in the importance of conducting research on groups with different characteristics.

• Journal of Convergence for Information Technology
• /
• v.11 no.3
• /
• pp.250-260
• /
• 2021

The purpose of this study is to investigate muscle function and symmetry index during whole body vibration exercise using lower extremity training posture for throwing athletes. For throwing athletes in their 20s(6 males, 4 females, age: 24.60±0.92years, height: 177.90±7.40cm, weight: 92.90±22.97kg), lower extremity training postures with squat, carphrase, and lunge movements. Whole body vibration exercise training was performed using. Tensiomyography(TMG) variables Time Delay(Td), Time Contraction(Tc), Time Sustain(Ts) Time Relaxation(Tr), and Displacement Maximumal(Dm) in the lower extremity joint muscles(biceps femoris(BF), gastrocnemius lateral(GL), gastrocnemius medial(GM), rectus femoris(RF), tibialis anterior(TA), lateral vastus(LV), medial latissimus(ML)), were measured to compare and analyze muscle activity, muscle fatigue, and left-right symmetry. The results of the study are left RF, VL, right VM (p<.05) in Td, VM (p<.05) in Tc, GM in Ts (p<.05), left RF in Tr, and right TA (p<. 05) showed a change. Therefore, it has been proven that various whole-body vibration training is an effective exercise with changes in muscle contraction, and stability of the core is secured by symmetry of the left and right muscles. For this reason, the whole body vibration exercise will have a positive effect on rehabilitation training, and it is believed that it will be able to improve performance.