• Journal of The Geomorphological Association of Korea
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• v.17 no.4
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• pp.71-83
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• 2010

In this study, the volume of shoreline retreat at sea-cliffs in the Taean peninsula(West Coast of Korea) was estimated and their erosion and seasonal landforms characteristics changes were investigated through multi-temporal aerial photographs and field survey. Based on the analysis of aerial photographs through ortho-correction, the results show that the length of shoreline and erosion area increase as erosion at sea-cliffs occurs in Pado-li and Dundu-li. To obtain the seasonal quantitative landforms changes and retreat of sea-cliffs, we marked top, middle, and bottom datum-points, from which the distance to the nearest bedrock was repeatedly measured. In these regions, the retreat of sea-cliffs gradually increases in spring to summer, but gradually decreases in autumn. In particular, the typhoon that has a great influence on the Korean peninsula in July to September in summer would drastically increase the retreat of sea-cliffs in comparison with other seasons. As the outcrop of sea-cliffs repeats freezing and thawing in winter, the retreat of sea-cliffs increases a little due to active mechanical weathering. To know the erosion and seasonal landforms changes of sea-cliffs, we took pictures of them in every month and then analyze their condition. The retreat of sea-cliffs was repeatedly occurred by the circulation of the erosion of sea-cliff base, landslides, the formation of slope sediment debris and their erosion, in that order.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.67-67
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• 2003

It is crucial to minimize setup errors of a cancer treatment machine using a high energy and to perform precise radiation therapy. Usually, port film has been used for verifying errors. The Korea Cancer Center Hospital (KCCH) has manufactured digital electronic portal imaging device (EPID) system to verify treatment machine errors as a Quality Assurance (Q.A) tool. This EPID was consisted of a metal/fluorescent screen, 45$^{\circ}$ mirror, a camera and an image grabber and could display the portal image with near real time KIRAMS has also made the acrylic phantom that has lead line of 1mm width for ligh/radiation field congruence verification and reference points phantom for using as an isocenter on portal image. We acquired portal images of 10$\times$10cm field size with this phantom by EPID and portal film rotating treatment head by 0.3$^{\circ}$, 0.6$^{\circ}$ and 0.9$^{\circ}$. To check field size, we acquired portal images with 18$\times$18cm, 19$\times$19cm and 20$\times$20cm field size with collimator angle 0$^{\circ}$ and 0.5$^{\circ}$ individually. We have performed Flatness comparison by displaying the line intensity from EPID and film images. The 0.6$^{\circ}$ shift of collimator angle was easily observed by edge detection of irradiated field size on EPID image. To the extent of one pixel (0.76mm) difference could be detected. We also have measured field size by finding optimal threshold value, finding isocenter, finding field edge and gauging distance between isocenter and edge. This EPID system could be used as a Q.A tool for checking field size, light/radiation congruence and flatness with a developed video based EPID.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.371-385
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• 2023

BACKGROUND/OBJECTIVES: Soy isoflavone (SIF) and soy lecithin (SL) have beneficial effects on many chronic diseases, including neurodegenerative diseases. Regretfully, there is little evidence to show the combined effects of these soy extractives on the impairment of cognition and abnormal cerebral blood flow (CBF). This study examined the optimal combination dose of SIF + SL to provide evidence for improving CBF and protecting cerebrovascular endothelial cells. MATERIALS/METHODS: In vivo study, SIF50 + SL40, SIF50 + SL80 and SIF50 + SL160 groups were obtained. Morris water maze, laser speckle contrast imaging (LSCI), and hematoxylin-eosin staining were used to detect learning and memory impairment, CBF, and damage to the cerebrovascular tissue in rat. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the oxidized glutathione (GSSG) were detected. The anti-oxidative damage index of superoxide dismutase (SOD) and glutathione (GSH) in the serum of an animal model was also tested. In vitro study, an immortalized mouse brain endothelial cell line (bEND.3 cells) was used to confirm the cerebrovascular endothelial cell protection of SIF + SL. In this study, 50 µM of Gen were used, while the 25, 50, or 100 µM of SL for different incubation times were selected first. The intracellular levels of 8-OHdG, SOD, GSH, and GSSG were also detected in the cells. RESULTS: In vivo study, SIF + SL could increase the target crossing times significantly and shorten the total swimming distance of rats. The CBF in the rats of the SIF50 + SL40 group and SIF50 + SL160 group was enhanced. Pathological changes, such as attenuation of the endothelium in cerebral vessels were much less in the SIF50 + SL40 group and SIF50 + SL160 group. The 8-OHdG was reduced in the SIF50 + SL40 group. The GSSG showed a significant decrease in all SIF + SL pretreatment groups, but the GSH showed an opposite result. SOD was upregulated by SIF + SL pretreatment. Different combinations of Genistein (Gen)+SL, the secondary proof of health benefits found in vivo study, showed they have effective anti-oxidation and less side reaction on protecting cerebrovascular endothelial cell. SIF50 + SL40 in rats experiment and Gen50 + SL25 in cell test were the optimum joint doses on alleviating cognitive impairment and regulating CBF through protecting cerebrovascular tissue by its antioxidant activity. CONCLUSIONS: SIF+SL could significantly prevent cognitive defect induced by β-Amyloid through regulating CBF. This kind of effect might be attributed to its antioxidant activity on protecting cerebral vessels.

• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.90-94
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• 2023

Objective : Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications. Methods : A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle. Results : There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation. Conclusion : In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.

• Korean Chemical Engineering Research
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• v.61 no.1
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• pp.123-141
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• 2023

A sufficient amount of data with quality is needed for training artificial neural networks (ANNs). However, developing ANN models with a small amount of data often appears in engineering fields. This paper presented an ANN model to improve prediction performance of the ammonia emission amount with 83 data. The ammonia emission rate included eleven inputs and two outputs (maximum ammonia loss, N_max and time to reach half of N_max, K_m). Categorical input variables were transformed into multi-dimensional equal-distance variables, and 13 data were added into 66 training data using a generative adversarial network. Hyperparameters (number of layers, number of neurons, and activation function) of ANN were optimized using Gaussian process. Using 17 test data, the previous ANN model (Lim et al., 2007) showed the mean absolute error (MAE) of K_m and N_max to 0.0668 and 0.1860, respectively. The present ANN outperformed the previous model, reducing MAE by 38% and 56%.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.697-702
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• 2023

Recently, with the introduction of drones, a core technology of the 4th industrial revolution, various convergence education using drones is being conducted in school education sites. In particular, drone theory and practice education is being conducted in connection with free semester classes and career exploration. The drone convergence education program has higher learner satisfaction than simple demonstration and practice education, and the learning effect is high due to direct practical experience. However, since practical education is being conducted for a large number of learners, it is impossible to restrict and control the flight of a large number of drones in a limited place. In this paper, we propose a monitoring system that allows the instructor to monitor multiple drones in real time and learners to recognize collisions between drones in advance when multiple drones are operated, focusing on education operated in schools. The communication module used in the experiment was equipped with GPS in Murata LoRa, and the server and client were configured to enable monitoring based on the location data received in real time. The performance of the proposed system was evaluated in an open space, and it was confirmed that the communication signal was good up to a distance of about 120m. In other words, it was confirmed that 25 educational drones can be controlled within a range of 240m and the instructor can monitor them.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.2
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• pp.219-230
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• 2023

Cities are continued to be highly advanced and metropolitanized. Lands adjacent to road make entry/exit connection increase along with construction of facilities for various purposes. However, in the absence of specific installation standards of entry and exit connection, inappropriate access location, types of access, and operation methods are deteriorating the level of traffic services at existing roads and intersections. Therefore, in order to minimize the traffic impact from entrances connected to minor arterial roads and colletor roads, first, this study re-established the waiting length in the intersection of upstream and downstream and length required for changing lanes and between entrance/exit and connection, considering the road and traffic environment in contact with the entrance. Second, it is suggested that the operation method depending on the connection type and whether to install left turn lane and acceleration and deceleration lane can be determined quantitatively by relation with the service level of nearby intersection after calculating the threshold amount of business site through negative social cost, which is the difference between the installation cost of the left turn lane and the acceleration and deceleration lane according to the type of access to the entrance and exit.

• Physical Therapy Korea
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• v.30 no.1
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• pp.50-58
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• 2023

Background: This study was carried out to determine whether non-face-to-face physical therapy would have similar exercise effects to face-to-face physical therapy. Hence, we developed an approach for patients, unable to visit hospitals due to circumstances such as the COVID-19 pandemic, to conduct physical therapy comfortably at home. Objects: This study aimed to compare the effects of a face-to-face and a non-face-to-face physical therapy treatment on improving a rounded shoulder posture. Methods: The participants with rounded shoulders were randomly divided into a face-toface group (n = 15) and a non-face-to-face group (n = 15), and each group performed exercises for four weeks. The exercise program consisted of the bare hands exercise, Thera-Band exercise, and foam roller exercise. The participants in the face-to-face group came to a designated place to perform their exercises, and those in the non-face-to-face group performed the exercises at their own home using Google Meet (Google). Acromial height, total scapular distance (TSD), shoulder pain and dysfunction index (SPADI), and pectoralis minor thickness were measured. Data analysis was performed using the R Statistical Software (R Core Team), and a normality test was performed using the Shapiro-Wilk test. Results: There were no significant differences between the face-to-face and the non-face-toface groups (p > 0.05). When comparing the differences before and after the exercises, both the face-to-face and the non-face-to-face groups showed significant differences in acromial height, SPADI, and pectoralis minor thickness (p < 0.05), and both groups showed no significant difference in TSD before and after the exercises (p > 0.05). Conclusion: The results of this study support the results of previous studies reporting that shoulder stabilization exercise and pectoralis minor stretching training improves round shoulders. In addition, this study revealed that both the face-to-face and the non-face-to-face physical therapy treatments had therapeutic effects.

• Journal of Navigation and Port Research
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• v.47 no.1
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• pp.10-17
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• 2023

A series of studies on the development of autonomous surface ships have been promoted in domestic and foreign countries. One of the main technologies for the development of autonomous ships is path-following control, which is closely related to securing the safety of ships at sea. In this regard, the path-following performance of an autonomous ship should be first evaluated at the design stage. The main aim of this study was to develop a visual and quantitative evaluation method for the path-following control performance of an autonomous ship at the design stage. This evaluation technique was developed using a computational fluid dynamics (CFD)-based path-following control model together with a line-of-sight (LOS) guidance algorithm. CFD software was utilized to visualize waves around the ship, performing path-following control for visual evaluation. In addition, a quantitative evaluation was carried out using the difference between the desired and estimated yaw angles, as well as the distance difference between the planned and estimated trajectories. The results demonstrated that the ship experienced large deviations from the planned path near the waypoints while changing its course. It was also found that the fluid phenomena around the ship could be easily identified by visualizing the flow generated by the ship. It is expected that the evaluation method proposed in this study will contribute to the visual and quantitative evaluation of the path-following performance of autonomous ships at the design stage.

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.124-132
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• 2023

When the building becomes high, the number of households increases and they are adjacent to the elevator. So, frequency of use of elevators will increase. Elevator noise is bound to increase in the future. However, there are currently no legal standards for elevator noise or measurement and evaluation methods that can clearly measure elevator noise in Korea. Although some methods for measuring elevator noise are presented in KS F ISO 16032, this standard is not a standard established for elevator noise. It is a standard that integrates the overall measurement method of building equipment and equipment, and the position of the microphone is selected by the experimenter during measurement. Elevator noise is characterized by a low sound pressure level as the noise in the mid-low frequency band is important. However, even today, complaints from residents about elevator noise are increasing. In this study, the position of the microphone that can most sensitively pick up the elevator noise when measuring the elevator noise was studied. According to the distance from the wall and the height from the floor, a total of 9 microphone positions were measured and analyzed. As a result of the experiment, it was confirmed that the elevator noise has a very high influence in the 63 Hz band. The measured value at the center point was identified as a factor that lowered the overall elevator noise level value.