• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.130-136
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• 2021

This study investigated the general characteristics of mobility disadvantaged persons with disabilities, and to suggest implications to ensure personal mobility with the greatest possible independence for the physically disabled in community. The survey questionnaire included the categories as follows: the general characteristics of the participants, the status of outing and mobility, usage of low-floor buses & taxi for the disabled, service improvement, and mobile support center. Data collected from 219 with physical disabilities were analyzed for this purpose by using descriptive statistics. The study results showed that 54.6% of the total tended to go out everyday, and 17.0% rarely. 53.4% could go out without any assistance, and the major obstacles not to go out were stairs and inconvenience of public transportation. 26.9% used low-floor buses, and 71.1% preferred to use taxi for the disabled. The average waiting time for the usage of low-flow buses and taxi was 66.57 minute and 42.65 minute, separately. 78.7% insisted that the function of mobile support center in the community should be expanded, whereas only 49.8% recognized the role of mobile support center. Based on the study results, the researchers suggested to facilitate access by persons with disabilities to mobility aids, and to improve the actual state of pedestrian environment. In addition, the function of mobile support center should be expanded to help the mobility disadvantaged persons live independently in community, thereby contributing to the promotion of their quality of life.

• Journal of Environmental Impact Assessment
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• v.31 no.6
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• pp.423-437
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• 2022

Parts of damaged trees are being transplanted in accordance with the Environmental Impact Assessment Manual. Problems such as death or poor growth are constantly being addressed in the process of transplanting trees from the forest they originally inhabited to temporary and final transplant sites. The purpose of this study is to analyze the differences in soil properties in the surrounding forest, the temporary transplant site, and the construction site and to suggest methods for improving the soil to make it suitable for the growth of transplanted trees. For 10 development projects, 2 soil samples were sampled from the surrounding forest, temporary transplant site, and construction site. A total of 60 soil samples were analyzed for physical and chemical properties. Among the physical properties such as coefficient of permeability, available moisture, and hardness, and chemical properties such as acidity, organic matter content, total nitrogen, and available P showed significant differences among groups. The soil of the construction site is harder than the surrounding forest because of construction equipments, the coefficient of permeability is higherthan the surrounding forest because of high sand content, and the available moisture was low. It does not retain the moisture necessary for plants in the soil and drains immediately. It is necessary to implement tillage to improve the physical properties and structure of the soil. In addition, it is necessary to cover the surface with wood chips or fallen leaves after adding mature organic matter to improve the physical and chemical properties of the soil together.

• Journal of Cadastre & Land InformatiX
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• v.52 no.1
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• pp.105-118
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• 2022

The demand for information related to 3D spatial objects model in metaverse, smart cities, digital twins, autonomous vehicles, urban air mobility will be increased. 3D model construction for spatial objects is possible with various equipments such as satellite-, aerial-, ground platforms and technologies such as modeling, artificial intelligence, image matching. However, it is not easy to quickly detect and convert spatial objects that need updating. In this study, based on spatial information (features) and attributes, using matching elements such as address code, number of floors, building name, and area, the converged building DB and the detected building DB are constructed. Both to support above and to verify the suitability of object selection that needs to be updated, one system prototype was developed. When constructing the converged building DB, the convergence of spatial information and attributes was impossible or failed in some buildings, and the matching rate was low at about 80%. It is believed that this is due to omitting of attributes about many building objects, especially in the pilot test area. This system prototype will support the establishment of an efficient drone shooting plan for the rapid update of 3D spatial objects, thereby preventing duplication and unnecessary construction of spatial objects, thereby greatly contributing to object improvement and cost reduction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.87-94
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• 2023

As the latest weapon systems and electronic equipments are increasingly demanding stealth technology to improve the survivability of allies, it is necessary to implement low-observability technology that reduces the radar cross section(RCS). In order to implement this stealth technology, a method for low RCS characteristics by applying a shape design or a electromagnetic wave absorber is widely used. However, active phased array antennas have structural limitations in shape design, also when a absorber is applied to it, the performance of the antenna is degraded. Therefore, in this paper, in order to realize the low RCS characteristics of the active phased array antenna operating in the X-band, individual radiating elements suitable for applying the radio wave absorber were selected, and a 13x13 array antenna was designed and manufactured. Next, by comparing the measured results of the relative RCS and electrical performance for the manufactured antenna according to the presence and type of the absorber, it is shown that the electrical performance is maintained at an equal or higher level while obtaining the low RCS characteristics. Thereby the method proposed in this paper for implementing the low RCS characteristics was validated. Finally, it was confirmed that when the wave absorber is applied to the array antenna, the limitation of its performance deterioration can be overcome.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.23-34
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• 2009

In the railroad rolling stock depot, long-term maintenance tasks is done regularly every two or four year basis to maintain the functionality of equipments and rolling stock body or for the repair operation of the heavily damaged rolling stocks by fatal accidents. This paper addresses the computer simulation model building for the rolling stock maintenance shop for the CDC(Commuter Diesel Car) and Generator Car planned to be constructed at Daejon Rolling Stock Depot, which will be moved from Yongsan Rolling Stock Depot. We evaluated the processing capacity of two layout design alternatives based on the maintenance process chart through the developed simulation models. The performance measures are the number of processed cars per year, the cycle time, shop utilization, work in process and the average number waiting car for input. The simulation result shows that one design alternative outperforms another design alternative in every aspect and superior design alternative can process total 340 number of trains per year 15% more than the proposed target within the current average cycle time.

• Journal of the Korean Geotechnical Society
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• v.24 no.1
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• pp.111-118
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• 2008

In the study a 2 dimensional model test was executed to grasp the effect of the taking load of equipments on the ground when improving a soft ground like dredging reclaimed ground. The static load and the dynamic load in the consolidated model ground was $0.02kg/cm^2,\;0.03kg/cm^2\;and\;0.04kg/cm^2$ respectively. After consolidating far two months by consolidation load of $0.02kg/cm^2,\;0.03kg/cm^2\;and\;0.04kg/cm^2$ respectively, the ultimate bearing capacity was $0.16kg/cm^2,\;0.19kg/cm^2,\;0.24kg/cm^2$ respectively. And the energy price of dynamic load test at the same point as the settlement of static load test indicated $E=336{\sim}945kg{\cdot}cm,\;E=252{\sim}780kg{\cdot}cm\;and\;E=323{\sim}727kg{\cdot}cm$ for each consolidation load. When the static load and the dynamic load operated at the same ground condition, the heaving quantity was bigger in the case of the dynamic load than in the case of the static load, and the horizontal displacement quantity the in the case of dynamic load was exhibited very deficiently compared to the quantity in the case of static load test.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.3
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• pp.123-129
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• 2023

if we know what we're looking at, we can get a lot of information. Due to the development of eye tracking, Information on gaze point can be obtained through software provided by various eye tracking equipments. However, it is difficult to estimate accurate information such as the actual gaze depth. If it is possible to calibrate the eye tracker with the actual gaze depth, it will enable the derivation of realistic and accurate results with reliable validity in various fields such as simulation, digital twin, VR, and more. Therefore, in this paper, we experiment with acquiring and calibrating raw gaze depth using an eye tracker and software. The experiment involves designing a Deep Neural Network (DNN) model and then acquiring gaze depth values provided by the software for specified distances from 300mm to 10,000mm. The acquired data is trained through the designed DNN model and calibrated to correspond to the actual gaze depth. In our experiments with the calibrated model, we were able to achieve actual gaze depth values of 297mm, 904mm, 1,485mm, 2,005mm, 3,011mm, 4,021mm, 4,972mm, 6,027mm, 7,026mm, 8,043mm, 9,021mm, and 10,076mm for the specified distances from 300mm to 10,000mm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.693-702
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• 2009

In the Seoul metropolitan area (SMA), transportation sector is the largest source of air pollutant emissions. Of the total amount of air pollutant emissions in the SMA, about 52% of the particulate matter emissions and 59% of the nitrogen oxide emissions are from superannuated heavy diesel vehicles. To lessen the air pollutant emissions from superannuated heavy vehicles in the SMA, this study devised several strategies for operating Environmental Zone (EZ) program, which requires superannuated heavy diesel vehicles to install reduction equipments as well as restricts them entering part of the SMA, and evaluated the effects of different strategies on air pollution in the SMA. By using the Korean traffic statistics, an evaluation has been made of six EZ scenarios, which were devised by different target areas and vehicles. The results showed that the EZ program with retrofitting a DPF (Diesel Particulate Filter) equipment to 7-year-old heavy diesel vehicles and early scrapping of pre-1998 heavy diesel vehicles is the most efficient alternative in terms of air pollution reduction. In addition, the results showed that the magnitude of air pollution reduction increases when implementing the EZ program to all entering superannuated heavy diesel vehicles to the SMA rather than registered ones in the SMA.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1189-1195
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• 2023

In scenarios involving inspections and verifications of nuclear facilities, ensuring the proper functioning of on-site safeguards equipment is crucial. There have been precedents in Kazakhstan where equipment failed to operate properly due to extremly cold temperatures, and the year-round minimum temperature at North Korea's Punggye-ri nuclear test site is approximately minus 30 degrees Celsius. To ensure the proper functioning of equipment in extreme environments for on-site verification of nuclear activities on the Korean Peninsula, relevant research is necessary. This includes confirming the functionality of equipment used in inspections and verifications, as well as analyzing factors that may disrupt their normal operation. This study aims to conduct a risk analysis for the normal operation of equipment in extreme environments and develop criteria and procedures for environmental-based performance testing. To achieve this, we conducted a risk analysis based on IAEA safeguards, analyzed the utilization of equipment, and performed a risk analysis associated with transportation for on-site verification considering the environmental characteristics of the Korean Peninsula. Furthermore, we provided performance testing criteria and procedures. The research results can be utilized as reference material in the verification and monitoring processes of nuclear activities.

• Korean Journal of Construction Engineering and Management
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• v.25 no.1
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• pp.62-72
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• 2024

Due to the distribution structure of domestic temporary equipment, quality control of temporary equipment is essential because more than 80% of temporary equipment is repeated and reused. Due to this importance, the Ministry of Land, Infrastructure and Transport has proposed quality management standards for temporary equipment for 10types of temporary equipments, including steel pipe support, but the overall quality of temporary eqipment cannot be confirmed because the quality is managed through sampling quality tests. In addition, although quality control standards exist for temporary material rental company, practical utilization was investigated and analyzed to be very low as they are mainly presented based on qualitative inspection standards by visual inspection. Therefore, the purpose of this study is to develop individual temporary material/quality/delivery management standards (Guides) for temporary equipment rental company to preemptively secure the quality of temporary equipment before bringing them into the construction site. If the standards developed through this study are applied to domestic temporary equipment rental companies, it is expected that high-quality temporary equipment with secured quality will be brought into the construction site as the quality of temporary equipment quality of domestic medium and small temporary equipment rental companies is improved safety accidents related to temporary structures.