• Journal of Korean Society of Forest Science
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• 제108권2호
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• pp.216-223
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• 2019

This study was conducted to measure the changes in the geological and soil properties following slow-moving landslide events in Yangbuk-myun and Gyungju-si, Gyeongsangbuk-do, South Korea. The geological characteristics of the study site comprised black shale in the Gyeongsang nodal group formed in the Cretaceous period and quartz feldspar carcinoma in the east side with conglomerate in the Yeonil group formed in the Quaternary period. The study site exhibited the geologic characteristics of a slow-moving landslide with severely weathered rocks. The maximum collapsing depth of the slow-moving landslide was 12.0 m with colluvial deposits. The strike and joint aspects in the slope areas of the slow-moving landslides were $N46^{\circ}E$ in lower slope and $N62^{\circ}E$ in upper slope, respectively. Soil hardness of ${\leq}20cm$ deep was not measured because of the completely disturbed soil resulting from soil creeping. Soil from 25 to 90 cm deep was 1.4-4.7 times softer in the slow-moving landslide areas than in the undisturbed or natural forests. Soil bulk density was $1.24-1.29g/cm^3$ in land creep areas. Soil bulk in both areas was 1.6 times denser than that in the natural forest. The soil pore space was 51.5-53.3% in the land creep areas. The values are 1.3-1.4 times lower than those within the natural forest. Black shale areas showed the lowest coefficient of permeability (8.75 E-06 cm/s) and mesopore ratio (pF 2.7: 9.8%) compared with those resulting from other study areas.

• Tunnel and Underground Space
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• 제29권4호
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• pp.230-242
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• 2019

While various automatic rock fracture survey methods have been researched, the evaluation of the accuracy of these methods raises issues due to the absence of a metric which fully expresses the similarity between automatic and manual fracture maps. Therefore, this paper proposes a geometry similarity metric which is especially designed to determine the overall similarity of fracture maps and to evaluate the accuracy of rock fracture survey methods by a single number. The proposed metric, Scanline Intersection Similarity (SIS), is derived by conducting a large number of scanline surveys upon two fracture maps using Python code. By comparing the frequency of intersections over a large number of scanlines, SIS is able to express the overall similarity between two fracture maps. The proposed metric was compared with Intersection Over Union (IoU) which is a widely used evaluation metric in computer vision. Results showed that IoU is inappropriate for evaluating the geometry similarity of fracture maps because it is overly sensitive to minor geometry differences of thin elongated objects. The proposed metric, on the other hand, reflected macro-geometry differences rather than micro-geometry differences, showing good agreement with human perception. The metric was further applied to evaluate the accuracy of a deep learning-based automatic fracture surveying method which resulted as 0.674 (SIS). However, the proposed metric is currently limited to 2D fracture maps and requires comparison with rock joint parameters such as RQD.

• Journal of Internet Computing and Services
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• 제19권6호
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• pp.41-51
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• 2018

Recently, in the field of video surveillance, deep learning based learning method is applied to intelligent video surveillance system, and various events such as crime, fire, and abnormal phenomenon can be robustly detected. However, since occlusion occurs due to the loss of 3d information generated by projecting the 3d real-world in 2d image, it is need to consider the occlusion problem in order to accurately detect the object and to estimate the pose. Therefore, in this paper, we detect moving objects by solving the occlusion problem of object detection process by adding depth information to existing RGB information. Then, using the convolution neural network in the detected region, the positions of the 14 keypoints of the human joint region can be predicted. Finally, in order to solve the self-occlusion problem occurring in the pose estimation process, the method for 3d human pose estimation is described by extending the range of estimation to the 3d space using the predicted result of 2d keypoint and the deep neural network. In the future, the result of 2d and 3d pose estimation of this research can be used as easy data for future human behavior recognition and contribute to the development of industrial technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권7호
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• pp.380-386
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• 2019

Shoulder joint pain is a very common musculoskeletal disorder, in which about 20 percent of adults experience it more than once in their lives. In this study, an objective assessment was made that subacromial space was increased by pectoralis minor stretching exercise, which has a positive effect on impingement syndrome and shoulder pain. Also, This study examined the effects on pectoralis minor length(PML) and acromio-humeral distance(AHD) following pectoralis minor self-stretching exercise in normal adults. In this study, a total of 30 subjects were recruited and randomly divided into a self-stretching exercise group(n=15) and manual stretching exercise group(n=15) to compare the immediate effects of treatment. Studies have shown that both groups have significantly increased both PML and AHD within the group(p<.05). There was no statistically significant difference in the comparison between the groups(p>.05). The results suggest that self-stretching exercise can be recommended as a treatment method for impingement syndrome and prevention of shoulder disease.

• Journal of the Korea Institute of Building Construction
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• 제19권3호
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• pp.209-217
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• 2019

EMP (Electromagnetic Pulse) usually means High Power Electromagnetic Wave (HPEM). In the case of the shielding plate against the EMP, there is a possibility of deterioration of the electromagnetic wave shielding performance due to the skill of the constructor, bad construction, deformation of the shielding plate at the connection portion (joint portion). The inefficient use of space due to the separation distance is also pointed out as a problem. Therefore, this study aims to derive the optimum electromagnetic shielding condition by applying ATMSM to concrete as a part of securing electromagnetic wave shielding performance with reflection loss against concrete wall. Experimental parameters included concrete wall thickness and application of Zn-Al ATMSM. For the concrete wall, the wall thickness was 100 to 300mm, which is generally applied, and experimental parameters were set for the application of Zn-Al metal spraying method to evaluate electromagnetic shielding performance. Experimental results showed that as the thickness increases, the electromagnetic shielding performance increases due to the increase of absorption loss. In addition, after the application of Zn-Al ATMSM, the average shielding performance increased by 56.68 dB on average, which is considered to be increased by the reflection loss of the ATMSM. In addition, it is considered that the shielding performance will be better than that when the conductive mixed material and the ATMSM are simultaneously applied.

• The Journal of Korean Academy of Prosthodontics
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• 제57권4호
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• pp.382-388
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• 2019

Increased anterior teeth mastication following posterior teeth loss leads to greater anterior occlusal force. It may cause greater attrition of anterior teeth, traumatic force occlusion (TFO), also often followed by antagonist extrusion and occlusal disharmony. This clinical report describes the treatment for a 67-year-old female patient diagnosed with loss of both maxillary and left mandibular posterior teeth, severe attrition of maxillary and mandibular anterior teeth and extrusion of multiple teeth. A diagnostic cast was mounted on articular in centric relation (CR) position to evaluate vertical dimension (VD) and interspace. To provide adequate space for the prosthetic reconstructions, VD was increased by 3 mm on the anterior pin. And then diagnostic wax-up was completed upon that VD. Wax-up was converted to provisional restorations and verified in the patient's mouth and the final restorations were delivered. Clinical follow up examination held 3 months after temporary restoration owing to changes in vertical dimension revealed proper function in mastication without evidence of temporo-mandibular joint (TMJ) disorders. This clinical report presents successfully restoring severe attrition case with increasing vertical dimension resulting in satisfaction in esthetics and function.

• Tunnel and Underground Space
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• 제31권6호
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• pp.623-646
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• 2021

As the demand for electric power increases with acceleration of electrification at home and abroad, the needs for coal-fired electrical power plant are accordingly increased. However, these coal-fired electrical power plants induce also many environmental problems such as increase of air pollutants, increase of possibility of land contamination by reclamation of coal ash, even though these power plants have a good economical efficiency. In case of a by-product of coal-fired electrical power plants, only 70% of them are recycled and the remaining 30% of by-product are fully buried in surrounding ground. Consequently, this study deals with coal ash backfilling mechanism in abandoned mine openings for the purposes of increasing the coal ash recycling rate as well as securing the mine area stability. In order to analyze the backfill and ground reinforcement by interaction between rock mass and backfills, the copying samples of discontinuous surface with different roughnesses were produced for bond strength tests and direct shear tests. And statistical analysis was also conducted to decide the characteristics of bond and shear behavior with joint roughness and their curing day. Numerical simulations were also analyzed for examining the effect of interface behavior on ground stability.

• The Journal of the Korea Contents Association
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• 제22권6호
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• pp.92-103
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• 2022

This study was designed to explore the ways to improve the organization and implementation of the curriculum for the small rural middle schools. In order to do this, the situations and demands in organizing and operating the curriculum were analyzed through interviews and classroom observations. Having separated the country into 5 distinct regions and the cases of 10 small rural middle schools across these regions of the country were directly observed and analyzed. As a result of the study, it was necessary to prepare a fundamental solution to the following problems: 1) insufficient linkage between school levels of integrated operating schools in terms of curriculum, 2) lack of educational facilities and cultural space in rural areas in terms of local communities, and 3) supply and demand of teachers in small-scale middle schools in rural areas in terms of supply and demand of teachers. Based on the discussed issues, the following implications could be drawn for the improvement and support of school curriculum organization and implementation. Firstly, the autonomy in organizing and operating curriculums for small rural middle schools should be greatly expanded so that integrated schools or joint curriculums between schools can be operated in a robust manner. Secondly, it needs to strengthen the out-of-school support for small rural middle schools alongside local governments and local communities, including the operation of Edu buses and the construction of multipurpose educational and cultural centers. Finally, it is necessary to address the difficulties of operating circuit teachers by systematically expanding the pool of teachers and instructors, and managing teachers and instructors at the level of the local education office.

• The Journal of the Korea institute of electronic communication sciences
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• 제17권5호
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• pp.941-948
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• 2022

Disaster response robots are deployed to disaster sites where human access is difficult and dangerous. The disaster response robots explore the disaster sites prevent a structural collapse and perform lifesaving to minimize damage. It is difficult to operate robots in the disaster sites due to rough terrains where various obstacles are scattered, communication failures and invisible environments. In this paper, we developed a series connectable wheeled robot module. The series connectable wheeled robot module was developed into two types: an active driven robot module and a passive driven robot module. A wheeled robot was built by connecting the two active type robot modules and one passive type robot module. Two robot modules were connected by one DoF rotating joint, allowing the wheeled robot to avoid obstructions in a vertical direction. The wheeled robot performed driving and obstacle avoidance using only pressure sensors, which allows the wheeled robot operate in the invisible environment. An obstacle avoidance experiment was conducted to evaluate the performance of the wheeled robot consisting of two active driven wheeled robot modules and one passive driven wheeled robot module. The wheeled robot successfully avoided step-shaped obstacles with a maximum height of 80 mm in a time of 24.5 seconds using only a pressure sensors, which confirms that the wheeled robot possible to perform the driving and the obstacle avoidance in invisible environment.

• The Journal of Korean Academy of Prosthodontics
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• 제61권1호
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• pp.33-43
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• 2023

Pathological wear across the entire dentition causes problems such as collapsed occlusal plane, reduced vertical dimension, anterior premature contact, inadequate anterior guidance, and tooth migration, thereby induce symptoms such as temporomandibular joint disorder, reduced masticatory efficiency, and tooth hypersensitivity. For the treatment of patients with excessive wear, evaluation of vertical dimension should be preceded along with analysis of the cause. The patient in this case was a 45-year-old female with a history of orthognathic surgery. Through clinical examination, radiographic examination, and model analysis, overall tooth wear, interdental spacing in the anterior maxillary region, retruded condylar position, and insufficient interocclusal space for prosthetic restoration were confirmed. Full mouth rehabilitation with increased vertical dimension was planned, the patient's adaptation to the new vertical dimension was evaluated with a removable occlusal splint and temporary prosthesis, and cross-mounting was performed based on the temporary restoration to fabricate the definitive zirconia prosthesis, maintaining the adjusted vertical dimension. It showed satisfactory functional and esthetic results through stable restoration of the occlusal relationship.