• Journal of the Institute of Convergence Signal Processing
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• v.21 no.1
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• pp.21-28
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• 2020

In this paper, a new type of electric wheelbarrow is proposed and developed. The developed electric wheelbarrow is equipped with an attitude reference system(ARS) sensor, which consists of 3-axis acceleration sensor and 2-axis Gyro sensor so that it can estimate pitch angle and roll angle. When an operator tilts the wheelbarrow up and down, the pitch angle is detected. The sign of the pitch angle is interpreted as the operator's intention for moving the wheelbarrow forward or backward and the controller drives the wheel of the wheelbarrow with the velocity according to the magnitude of the detected pitch angle. A cargo box of the wheelbarrow is designed to rotate and is controlled to maintain level always, so an operator can handle the electric wheelbarrow easily and safely. The wheelbarrow consists of an in-wheel motor, a DC motor, motor drives, an ARS sensor considering economical use in industrial field. Three experiments are performed to verify the feasibility and stability of the electric wheelbarrow.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.1
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• pp.24-38
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• 2021

Objective : This study aimed to create a Korea translation of the Evaluation in Ayres Sensory Integration (EASI) and to then test the adapted version for construct validity. Methods : The translation and content validation process were conducted in accordance with a four-step process, namely translation, integration, content validity examination, and backward translation. The construct validity of the translated version was evaluated using the EASI for children aged 3~12 years with and without sensory integration problems, comparing the two groups as well as preschool and school-aged groups. The group comparison was analyzed using the Mann-Whitney U test in SPSS. Results : In terms of content validity, all 20 items averaged more than 3.17 points. Of the four EASI categories, there was a difference in Sensory Perception (p=0.044) between the typical and sensory integration groups, and there was a statistical difference between tactile and vestibular sensations. Between the preschool and school-aged children, statistical difference was observed in two categories, namely Praxis and Ocular-Postural-Bilateral Motor Integration. Conclusion : Based on its construct validity, the Korean version of EASI is suitable for use in research. The construct validity study highlighted items that explain differences between typical and diagnostic children and items that explain those differences by age. Our findings could therefore be considered when interpreting EASI results.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.537-542
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• 2022

There is a limit to the current indoor air quality (IAQ) monitoring method using fixed sensors and devices. A mobile robot for IAQ monitoring was developed by mounting IAQ monitoring sensors on a small multi-legged robot to minimize vibration and protect the sensors from vibration while robot moves. The developed mobile robot used a simple gait mechanism to enable the robot to move forward, backward, and turns only with the combination of forward and reverse rotation of the two DC motors. Due to the simple gait mechanism, not only IAQ data measurements but also gait motion control were processed using a single Arduino board. Because the mobile robot has small number of electronic components and low power consumption, a relatively low-capacity battery was mounted on the robot to reduce the weight of the battery. The weight of mobile robot is 1.4kg including links, various IAQ sensors, motors, and battery. The gait and turning speed of the mobile robot was measured at 3.75 cm/sec and 14.13 rad/sec. The maximum height where the robot leg could reach was 33 mm, but the mobile robot was able to overcome the bumps up to 24 mm.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.3
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• pp.22-31
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• 2021

Purpose : This study aimed to conduct a translation, backtranslation, and content validity test of the Sensory Processing Measure (SPM) for Korean children. Methods : The translation and content validation process involved direct and backward translation; a test of equivalence between the two versions (the original SPM and the Korean version SPM; K-SPM) was performed using content-related evidence collected by a group of experts and a group of parents. Data analysis was carried out using Excel Content validity indices (CVI), mean, and standard deviation were used for the analysis of content validity. Results : The result of the comparison between the original SPM and K-SPM in the group of experts was 3.54 ± .74, the S-CVI/Avg for semanticity was .92, and the S-CVI/Avg for structure was .86. The results for the mean of the understanding test and the S-CVI/Avg were 3.48 ± .63 and .94, respectively. Conclusion : K-SPM will considerately be used as an assessment to identify sensory processing, praxis, and social participation issues for children in Korea. Further studies are suggested to increase the age range and the sample size for a more comprehensive applicability of the K-SPM to Korean children.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1207-1217
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• 2022

Vegetation indices using the reflectance of selected wavelength, associating with the monitoring purpose such as identifying the progress of crop growth, on the vegetation canopy surface is widely used in the digital agriculture technology. However, the surface reflectance anisotropy can distort the true value of vegetation index related to the condition of surface, even though the surface property be unchanged. That causes difficulty to observe accurately crop growth on the monitoring system. In this study, a simple type goniometer was designed to measure the reflectance from the anisotropic surface according to various zeniths and azimuths of sun and viewing sensor in the field. On the tarp like as Lambertian surface, the reflectance of Blue, Green, Red, Near-Infrared band was similar to the tarps' reflectance properties. However, the reflectance was slightly overestimated in the cloudy day. The relative difference values of vegetation indices on grass were overestimated for the forward viewing and underestimated for the backward viewing. In addition, enhanced vegetation index (EVI) showed less sensitive according to the positions of sun and sensor viewing. Field observation with a goniometer will be helpful to understand the anisotropy characteristics on the vegetation surface.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1069-1080
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• 2022

The tropospheric ozone is a pollutant that causes a great deal of damage to humans and ecosystems worldwide. In the event that ozone moves downwind from its source, a localized problem becomes a regional and global problem. To enhance ozone monitoring efficiency, geostationary satellites with continuous diurnal observations have been developed. The objective of this study is to derive the Tropospheric Ozone Movement Vector (TOMV) by employing continuous observations of tropospheric ozone from geostationary satellites for the first time in the world. In the absence of Geostationary Environmental Monitoring Satellite (GEMS) tropospheric ozone observation data, the GEOS-Chem model calculated values were used as synthetic data. Comparing TOMV with GEOS-Chem, the TOMV algorithm overestimated wind speed, but it correctly calculated wind direction represented by pollution movement. The ozone influx can also be calculated using the calculated ozone movement speed and direction multiplied by the observed ozone concentration. As an alternative to a backward trajectory method, this approach will provide better forecasting and analysis by monitoring tropospheric ozone inflow characteristics on a continuous basis. However, if the boundary of the ozone distribution is unclear, motion detection may not be accurate. In spite of this, the TOMV method may prove useful for monitoring and forecasting pollution based on geostationary environmental satellites in the future.

• Land and Housing Review
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• v.13 no.3
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• pp.1-20
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• 2022

This study analyses how much Korean visits to North Korea have an impact on the North Korean regional economy. It estimates the demand for North Korean tourism via the borders of North Korea, China, and Russia and South Korean expenses to be spent in North Korea. When asked if they are willing to visit North Korea within the next five years in case the pre-conditions of the visit to North Korea are satisfied, approximately 64.1% of the survey respondents indicated 'yes'. To estimate the demand, this research employed the analysis of purchase intention, popular in marketing, based on their willingness to visit. The annual demand for tourism was 4,136,361 persons. The average estimated expense per person is KRW 1,532,000 and the total annual expense is KRW 6,336.9 billion. Assuming that airfare is excluded from the total expense and the expense is made evenly in each tourist destination, the estimated amount to be spent in North Korea is KRW 2,838.7 billion per annum. The backward linkage effect of this expense on the North Korean regional economy is KRW 7,972.1 billion in total production inducement, KRW 2,619.4 billion in value-added inducement, and approximately 2,890,443 persons in employment inducement. The value-added inducement effect is estimated to be approximately 7.6% of the North Korean nominal GDP in 2020. South Korean tourism is expected to have a significant impact on the North Korean economy. As the demand for North Korean tourism is likely to increase steadily due to the expected increase in overseas travel demand by Koreans, inter-Korean cooperation is needed for the development of North Korean tourism infrastructure if conditions improve.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.101-113
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• 2022

This study is planned with the aim of developing a systematic construction process based on the scientific and engineering theory of the water-sealing grouting construction applied to the tunnel excavation process during the construction of the downtown underground traffic network, so that the construction quality of the relatively backward domestic tunnel water-sealing grouting construction is improved and continuously maintained no matter who constructs it. The main contents of the improved tunnel water-sealing grouting can be largely examined in the classification of tunnel water-sealing grouting application and the definition of grouting materials, the correlation analysis of groundwater pressure conditions with groundwater inflow, the study of the characteristic factors of bedrock, and the element technologies and injection management techniques required for grouting construction. Looking at the trends in global research, research in the field of theoretical-based science and engineering grouting is actively progressing in Nordic countries (Sweden, Finland, Norway, etc.), Japan, Germany, and the United States. Therefore, in this study, the algorithm is established through theoretical analysis of the elements of tunnel water-sealing grouting construction techniques to provide an integrated solution including a construction process that can effectively construct tunnel water-sealing grouting construction.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1169-1178
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• 2022

This study examines an effective operational plan of a maritime safety enforcement task that is distributed in the Ministry of Oceans and Fisheries and the Korea Coast Guard for maritime safety. Considering the sinking of the MV Sewol and Seohae vessels and the MV Hebei Spirit oil spill, normally marine safety accidents tend to not only damage human life, property, and marine environment but can also expand to disasters; therefore, precautionary measures are required. However, the Korean government takes superficial efforts in case of large-scale accidents. In case of the MV Sewol ferry, the government only focused on punishing the officials involved as a follow up and never mentioned any effective plan, such as "unification of maritime safety enforcement," in contrast to an advanced country. As a result, there are endless major and minor backward accidents. The probability of large-scale maritime accidents and backwardness accidents is increasing owing to vessels becoming large sized, high speed, and aged; sailors being unqualified; port traffic increase, development of marine leisure; and inefficiency dual marine safety systems. Therefore, based on the review of previous studies related to maritime safety, major advanced country's cases, and unified case of the vessel traffic service, this study suggests effective methods such as coastal vessel safety management, port state control and aid to navigation management, which are directly connected with maritime safety.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.1
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• pp.37-47
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• 2023

The black cutworm, Agrotis ipsilon (Hufnagel), is an important crop pest worldwide that feeds more than 80 plant species including cabbage, potato, maize, wheat and bean, and this moth is a typical pest attacking underground parts of crops. It has been known in farm booklets that the larvae of A. ipsilon overwinter in the soil in Korea, but no definitive data exist yet. This study was conducted to evaluate that the specific appearance time of A. ipsilon observed actually in the field could be explained when we assumed that this pest overwinters in a form of larvae or pupae. Degree day-based phenology models were applied for tracking forward or backward to find the predicted developmental stage which developed at a specific stage found in the field. As a result of the analysis, it was confirmed that an initial population could be established in a group that does not overwinter as larvae or pupae in Korea. In other words, the appearance of adults in early March to April could not be explained by the presence of domestic overwintering populations. Populations that overwinter as larvae or pupae in Korea were able to emerge as adults in June to July at the earliest. Therefore, the group of adults appearing in early spring is highly likely to be a population that migrated from outside Korea. Taken together, it was estimated that the colony of A. ipsilon in Korea would be formed by a mixture of a migrant population through long-distance migration and a overwintering population.