• The Journal of Engineering Geology
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• v.26 no.3
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• pp.315-324
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• 2016

Because of a fissility characteristics of shale in the Gyoungsang super-group, it breaks down to debris when daylighted by construction work and causes a slope unstability. To assess the durability property of shale, a series of slake durability tests was conducted by controlling test conditions such as shape of specimen, number of specimen, revolution speed, revolution number, drying temperature and pH of submerging liquid. For the specimen shape, cube one showed relatively lower durability index than cuboid and/or fan shape one. The test with the more number of specimens showed the less durability index because of a higher friction among specimens in the drum. The durability index is linearly decreased by increasing the total number of revolution, while the revolution velocity could not affect the index. And the durability index is also decreased by increasing the drying temperature of specimen and by decreasing the pH of submerging liquid. Because the durability index of shale is almost similar to that of crystalline rocks, the disintegration characteristics of shale could not be assessed by the slake durability test recommended by ISRM, and thus a new test method by changing the total revolution number may be required for the shale having fissility characteristics.

• Journal of Korean Foot and Ankle Society
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• v.2 no.2
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• pp.88-92
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• 1998

The course of the sural nerve in the calf has been well documented, but there is a general lack of information concerning the distal course of the nerve. The purpose of this study was to describe the distal course of the sural nerve and its surgical implications. Seven fresh amputated specimens were dissected to show the anatomy of the sural nerve in the foot and ankle. At the level of about 10cm proximal to the plantar surface, the sural nerve coursed anteriorly and inferiorly away from the Achilles tendon. 2 to 4 lateral calcaneal branches arose. The first branch of the lateral calcaneal branches coursed along the lateral border of the Achilles tendon, and it arose at 8cm proximal to the plantar surface in 2 specimens, 12cm proximal to the plantar surface in 4 specimens, and at 12cm proximal to the plantar surface in one specimen. The main nerve trunk continued distally plantar to the peroneal tendons and divided into two terminal branches and crossed peroneus longus tendon at the level of the inferior border of the calcaneo-cuboid joint, at about 3cm(range, $2.5\sim3.0$)cm from the plantar surface. In conclusion, a longitudinal incision lateral to the Achilles tendon would cross the path of the sural nerve at about 10cm proximal to the plantar surface. When the first branch of them arise more than 10cm above the plantar surface, a logitudinal incision lateral to the Achilles tendon may be made without damage. The other lateral calcaneal branches will be cut when we make transverse incision paralled to the plantar surface. The terminal branch also may be in danger by the same transverse incision.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.3
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• pp.393-406
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• 2016

In the sixth grade mathematics, drawing of development figures of the triangular prism and the quadrangular prism is recommended in terms of the creativity. In this sense, the teacher has the need to check in advance all the possible development figures of the triangular prism and the quadrangular prism before teaching on them. However, previous studies that currently give all the possible development figures of the triangular prism and the quadrangular prism are hard to find. For this reason, in this paper, as a study of teaching materials for the professional development of elementary school teachers, the method of finding all the possible development figures of the triangular prism and all the possible development figures of the quadrangular prism without omissions and overlaps and the number of each of development figures which can be obtained by that method are discussed. Here lengths of the three sides of base planes of the triangular prism are different each other and lengths of the four sides of base planes of the quadrangular prism are different each other. This discussion is needed in terms of a study of teaching materials in order to prepare for predictable questions to ask the number of the possible development figures of the triangular prism and the number of the possible development figures of the quadrangular prism in classes. In addition, through this discussion, this paper presents the development figures of the triangular prism and the development figures of the quadrangular prism without omissions and overlaps. And teachers can take advantage of them for determining the correctness of the development figures drew by students and guiding students to draw the development figures creatively in actual classes.

• Applied Microscopy
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• v.31 no.2
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• pp.207-214
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• 2001

Anatomy and ultrastructure of the modifeid Krana pattern have been studied in succulent Salsola collina Pall. Cylindrical leaves exhibited the Salsoloid Kranz type containing two layers of peripheral chlorenchyma that surrounded the water storage cells and vascular tissues. Small veins were also peripherally arranged, but mostly embedded in the vicinity of the inner chlorenchma without the orderly arrangement of the concentric layering of bundle sheath and mesophyll cells. The current study mainly focused on the chlorenchyma tissue abutting such minor veins. The outer columnar layer exhibited features similar to the characteristics of palisade mesophyll cells, while the inner cuboid layer to the bundle sheath cells of a typical $C_4$ Kranz pattern. Cellular components of the inner chlorenchyma were centripetal and numerous, but starch-laden chloroplasts were rudimentary in the thylakoidal system. The outer chlorenchyma demonstrated normally developed chloroplasts having well-stacked thylakoids and plastoglobuli. Branched and complicated plasmodesmata frequently occurred in thick interfaces of the two layers, implying the active movement of the photosynthates between them. The present data were mostly congruent with one of the structural features of the C4 subtypes , NADP-ME type, reported in the $C_4$ pattern. The Kranz pattern encountered in this Salsola probably has been directly related to the structural modification that occurred during a functional adaptation to the $C_4$ photosynthesis.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.4
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• pp.331-339
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• 2013

LiDAR has been one of the widely used and important technologies for 3D modeling of ground surface and objects because of its ability to provide dense and accurate range measurement. The objective of this research is to develop a method for automatic detection and modeling of railroad power lines using high density LiDAR data and RANSAC algorithms. For detecting railroad power lines, multi-echoes properties of laser data and shape knowledge of railroad power lines were employed. Cuboid analysis for detecting seed line segments, tracking lines, connecting and labeling are the main processes. For modeling railroad power lines, iterative RANSAC and least square adjustment were carried out to estimate the lines parameters. The validation of the result is very challenging due to the difficulties in determining the actual references on the ground surface. Standard deviations of 8cm and 5cm for x-y and z coordinates, respectively are satisfactory outcomes. In case of completeness, the result of visual inspection shows that all the lines are detected and modeled well as compare with the original point clouds. The overall processes are fully automated and the methods manage any state of railroad wires efficiently.

• Korean Journal of Plant Taxonomy
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• v.38 no.1
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• pp.1-16
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• 2008

Anatomical features of seed coat were examined on Trollius, Calathodes, and Caltha of Ranunculaceae to evaluate the taxonomic circumscription of Megaleranthis saniculifolia, which is monotypic and endemic in Korea. Megaleranthis saniculifolia showed the exotestal type of seed coat exhibiting a well-developed palisade structure in exotesta and its external surface of exotesta cells was concave. On the other hand, the shape of exotesta cells in Caltha was cuboidal and the outer surface was smooth. The exotesta of Calathodes seeds was formed of the palisade structure like M. saniculifolia, but the outer surface of exotesta cells was smooth. The palisade structure was much better developed in the exotesta of Calathodes as well as Megaleranthis seeds than in the exotesta of Trollius seeds. The outer surface of exotesta cells in Trollius was either convex or concave according to the species examined. Since the genera of the subtribe Calthinae of the family display differences in seed sculpturing and the anaotmy of seed coat, these characteristics are useful to access taxonomic relationships among them. The morphological and anatomical features of seed coat suggest that Megaleranthis be possibly allied with Trollius rather than Caltha or Calathodes. Concave surface of seed coat cells and well-developed palisade structure of exotesta are shared by M. saniculifolia and some species of Trollius in common.

• Restorative Dentistry and Endodontics
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• v.42 no.3
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• pp.206-215
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• 2017

Objectives: To determine the combined effect of fatigue cyclic loading and thermocycling (CLTC) on the shear bond strength (SBS) of a resin cement to zirconia surfaces that were previously air-abraded with aluminum oxide ($Al_2O_3$) particles at different pressures. Materials and Methods: Seventy-two cuboid zirconia specimens were prepared and randomly assigned to 3 groups according to the air-abrasion pressures (1, 2, and 2.8 bar), and each group was further divided into 2 groups depending on aging parameters (n = 12). Panavia F 2.0 was placed on pre-conditioned zirconia surfaces, and SBS testing was performed either after 24 hours or 10,000 fatigue cycles (cyclic loading) and 5,000 thermocycles. Non-contact profilometry was used to measure surface roughness. Failure modes were evaluated under optical and scanning electron microscopy. The data were analyzed using 2-way analysis of variance and ${\chi}^2$ tests (${\alpha}=0.05$). Results: The 2.8 bar group showed significantly higher surface roughness compared to the 1 bar group (p < 0.05). The interaction between pressure and time/cycling was not significant on SBS, and pressure did not have a significant effect either. SBS was significantly higher (p = 0.006) for 24 hours storage compared to CLTC. The 2 bar-CLTC group presented significantly higher percentage of pre-test failure during fatigue compared to the other groups. Mixed-failure mode was more frequent than adhesive failure. Conclusions: CLTC significantly decreased the SBS values regardless of the air-abrasion pressure used.

• Journal of radiological science and technology
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• v.44 no.5
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• pp.443-449
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• 2021

In this study, the purpose is to present the foot inclination angle for realizing an image similar to that of the existing examination method and to present the clinical usefulness of the new examination method through comparison between the existing examination method and the newly designed standing foot oblique projection. A foot phantom was used, and the magnification of the image according to the angle was quantitatively evaluated by attaching a nut to the position of the cuboid of the phantom. The internal oblique image acquired using a 30° wedge was set as the standard image. And that image was compared with the images acquired by changing the angle of the foot from 20° to 65° at intervals of 5°. Image evaluation was performed by 3 radiological technologists, and qualitative evaluation using a Likert 5-point scale for evaluation items of true oblique view and quantitative evaluation of the value obtained by measuring the diameter of a nut in each image were performed as image evaluation. For data analysis, reliability analysis between the measure and comparative analysis of the average value for each angle were performed. The qualitative evaluation score for each image was 4.5 to 5 points for most questions in the case of the standard image. And 4 points or less for most questions in the images with a foot angle of 45° or less, and an evaluation score close to the standard image was obtained in the image of 50° or more. And in the quantitative evaluation, the diameter of the nut was measured to be 9.28~9.56 mm. The qualitative evaluation showed a reliability of 0.95~1.0 and the quantitative evaluation was 0.62. As a result of comparing and analyzing the average of the quantitative and qualitative average values for each angle image, the group with the average value most similar to the standard image was images obtained at 55° and 60°, and in the post-analysis, the images of both groups were the same group as the standard image(p<0.01). As a result of this study, it was found that the angle of inclination of the foot for realizing the image most similar to the existing image in the standing foot oblique projection is 55°~60°. In addition, if this test method is applied to the clinic, it is believed that it will help prevent safety accidents such as falls during the test and improve test efficiency by minimizing the movement of patients for the test.

• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.81-89
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• 2021

In recent years, the design of buildings is changing from formal to creative and freeform. Accordingly, the scale of construction technology is changing to architectural design and construction of irregular buildings. Using the FDM method, which is one of the 3D printing technologies, it is possible to manufacture various forms of irregular formwork inexpensively and quickly coMPared to the existing formwork, and it seems to be able to solve the manpower problem. Using a 3D printer, the PLA filament formwork is produced in the form of a cylinder and a rectangular cuboid, and the usability of the PLA filament formwork is confirmed by examining the compression strength test and the degree of deformation and reusability over 28 days of age. Different sizes of additional specimens are also conducted according to the size. As a result of the experiment, it was confirmed that the filament formwork itself has about 3~4MPa strength. As a result of reviewing data through existing linear studies and experiments, it is appropriate to use more than 60% infill, and it is advantageous in terms of strength. As a result of cutting and dismantling the filament formwork, the surface is very clean and there is no damage, so it can be reused.

• The Journal of the Acoustical Society of Korea
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• v.40 no.6
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• pp.649-659
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• 2021

Wall absorption treatment effectively reduces reverberation, but requires a large area for a live room and each wall absorption affects speech intelligibility differently. In this study, we try to find the most effective wall for the absorption treatment using the beamforming array microphone in terms of speech intelligibility. The absorption importance factor is defined by using the collision number of reflected sounds on each wall. It allows estimating how much the speech signal will be enhanced by the absorption treatment. A cuboid room with a size of 107 m³ and a reverberation time of 1.1 s is selected for the simulation. When a Helmholtz-type absorption is treated on the wall with the most significant importance factor, the modified clarity for 500 and 1k Hz is improved by 5.1 dB and 4.8 dB respectively, and the speech transmission index is enhanced by 0.06. The difference in results between the proposed method and commercial simulation code is less than a Just-Noticeable Difference (JND). The absorption treatment on the wall with the most significant importance factor shows improvement greater than the wall with the largest area, and its difference is larger than a JND value.