• Journal of agriculture & life science
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• v.45 no.1
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• pp.9-14
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• 2011

Larix kaempferi is a tree with a major economic impact and is processed in large quantity every year in Korea. This study was carried out to collect basic data for the reasonable use of Larix kaempferi and to investigate the relation between anatomical properties and modulus of rupture (MOR) for heartwood and sapwood. As the length of earlywood tracheid and the radial wall thickness of earlywood tracheid and latewood tracheid increased, the modulus of rupture (MOR) increased, but decreased with increasing microfibril angle. Statistical analysis by the stepwise regression technique shows that the main factors affecting the modulus of rupture (MOR) of heartwood are the microfibril angle and the radial wall thickness of latewood tracheid, while those affecting MOR of sapwood are the length of earlywood tracheid and the microfibril angle.

• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.565-574
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• 2004

The purpose of this paper was to investigate the block shear and the fracture in the net section, according to AISC Specifications, by analysing the shear lag effect in the block shear rupture of the single angle with three or four bolt connection. Specimen with three or four bolt connections showed that failure generally went from block shear with some net section failures to classic net section failures. From the test results, showed that the connection length, the thickness of angle, and reduction factor, which affect the block shear rupture, were investigated. According to the test results, it is suggested that the calculation of the net section rupture capacity by using the reduction factor of U, that was suggested by Kulak, is needed.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.125-132
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• 2011

The rupture of an expansion tube is mainly affected by the expansion ratio and the external shape of the punch used to expand the tube. In order to prevent the tube from rupture, the effect of the external shape of the punch should be considered in the design. The aim of this paper is to confirm the effect of key design parameters of the punch on rupture of the tube using a finite element analysis with a ductile damage model. The results of the analysis indicated that the expansion ratio of the tube was mainly affected by variation of the radius of the punch. However, the rupture was more affected by variation of the punch angle than the radius of the punch. The existence of a specific punch angle at which rupture did not occur, even if the radius of the punch was increased, was found from the results.

• Journal of Korean Society of Steel Construction
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• v.10 no.4 s.37
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• pp.721-730
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• 1998

In this paper, an experimental study have been many studies on the joints of steel structure, for it has great influences on the safety of structures. Research on block shear rupture of the joint receiving pure tension have been done in foreign countries, but not in Korea. This study focuses on the propriety of block shear design code, according to limited state design criteria of steel structures recently established in Korea, by an experiment on the joint of angle tension members. The methods of this study were to compare other study results on block shear rupture mode and ultimate capacity, and to evaluate the propriety of the criteria design code. The result is that tension yield shear ruptures and shear yield tension ruptures happened at the joint, and the experimental rupture load was 15% higher than the capacity entered in the criteria design code. We conclude that it is necessary to revaluate the block shear design code presented by many studies on the limited state design criteria of steel structures.

• Geomechanics and Engineering
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• v.9 no.4
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• pp.427-445
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• 2015

By means of finite element numerical simulation and pseudo-static method, the shallow-buried bilateral bias twin-tube tunnel subject to horizontal and vertical seismic forces are researched. The research includes rupture angles, the failure mode of the tunnel and the distribution of surrounding rock relaxation pressure. And the analytical solution for surrounding rock relaxation pressure is derived. For such tunnels, their surrounding rock has sliding rupture planes that generally follow a "W" shape. The failure area is determined by the rupture angles. Research shows that for shallow-buried bilateral bias twin-tube tunnel under the action of seismic force, the load effect on the tunnel structure shall be studied based on the relaxation pressure induced by surrounding rock failure. The rupture angles between the left tube and the right tube are independent of the surface slope. For tunnels with surrounding rock of Grade IV, V and VI, which is of poor quality, the recommended reinforcement range for the rupture angles is provided when the seismic fortification intensity is VI, VII, VIII and IX respectively. This study is expected to provide theoretical support regarding the ground reinforcement range for the shallow-buried bilateral bias twin-tube tunnel under seismic force.

• Geophysics and Geophysical Exploration
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• v.11 no.2
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• pp.137-147
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• 2008

Fault rupture directivity of the Odaesan earthquake, which was inferred to be the main cause of the high PGAvalue (> 0.1 g) unusually observed at the near-source region, was analyzed by using the data from the nearby (R < 100 km) dense seismic stations. The Boatwright's method (2007) was adopted for this purpose in which the azimuth and takeoff angle of the unilateral rupture directivity function could be estimated based on the relative peak ground-motions of seismic stations resulting from the nature of the rupture directivity. In this study, the approximate values of the relative peak ground-motions was derived from the difference between the log residuals of the point-source spectral model (Boore, 2003) for the main and secondary events based on the Random Vibration Theory. In this derivation, the spectral difference for a frequency range between the source corner frequencies of main and secondary events was considered to reflect only the effect of the fault directivity. The inversion result of the model parameters for the fault directivity function showed that the fault-plane of NWW-SEE direction dipping steeply to the North with high rupture velocity near upward in SE direction is responsible for the observed high level of ground-motion at the near-source region.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.201-211
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• 2015

Purpose: Designing equipment for processing, sorting, and other post-harvest operations of agricultural products requires information about their physical properties. This study was conducted to investigate some of the mechanical and physical properties of Moringa oleifera L. pods and seeds. Methods: Properties such as the length, width, thickness, bulk density, porosity, mass, static coefficient of friction, and angle of repose were determined as a function of moisture content. Statistical data and force-deformation curves obtained at each loading orientation and moisture level were analyzed for bioyield point, bioyield strength, yield force, rupture point, and rupture strength using a testrometric machine. Result: The basic dimensions (length, width, and thickness) of moringa pods and seeds were found to increase linearly from 311.15 to 371.45 mm, 22.79 to 31.22 mm, and 22.24 to 29.88 mm, respectively, in the moisture range of 12 to 49.5% d.b. The coefficient of friction for both pods and seeds increased linearly with an increase in moisture content on all the surfaces used. The highest value was recorded on mild steel, with 0.581 for pods and 0.3533 for seeds, and the lowest on glass for pods, with a value of 0.501, and of 0.2933 for seeds on galvanized steel. The bioyield and rupture forces, bioyield and rupture energies, and deformation of the pods decreased with an increase in moisture content to a minimum value, then increased with further decrease within the moisture content range, while the yield force increased to a maximum value and then decreased as the moisture content increased. Conclusion: These results will help to determine the most suitable conditions for processing, transporting, and storing moringa pods, and to provide relevant data useful in designing handling and processing equipment for the crop.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.278-282
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• 2013

This study was performed in 41 dogs with unilateral or bilateral medial patella luxation (MPL) and/or cranial cruciate ligament rupture (CCLR). These dogs were classified into 4 groups according to MPL grading system. Radiographic evaluation was performed for pelvis and stifle joint in the dogs. Norberg, inclination, quadriceps and femoral varus angle were measured and analyzed with MPL grading and the existence of cranial cruciate ligament rupture. The Norberg and inclination angle showed no differences between 4 grading groups and between CCLR and no CCLR groups. However, quadriceps and femoral varus angle were statistically different between grade 1, 2 and grade 3, 4 groups. They also have shown the statistical difference between CCLR and no CCLR group. Further studies for how these parameters affect the prognosis and the results of surgical treatment of MPL should be needed.

• Geomechanics and Engineering
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• v.29 no.6
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• pp.599-614
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• 2022

In this study, the reliability analysis of internal and external stabilities of Reinforced Soil Walls (RSWs) under static and seismic loads are investigated so that it can help the geotechnical engineers to perform the design more realistically. The effect of various variables such as angle of internal soil friction, soil specific gravity, tensile strength of the reinforcements, base friction, surcharge load and finally horizontal earthquake acceleration are examined assuming the variables uncertainties. Also, the correlation coefficient impact between variables, sensitivity analysis, mean change, coefficient of variation and type of probability distribution function were evaluated. In this research, external stability (sliding, overturning and bearing capacity) and internal stability (tensile rupture and pull out) in both static and seismic conditions were investigated. Results of this study indicated sliding as the predominant failure mode in the external stability and reinforcing rupture in the internal stability. First-Order Reliability Method (FORM) are applied to estimate the reliability index (or failure probability) and results are validated using the Monte Carlo Simulation (MCS) method. The results showed among all variables, the internal friction angle and horizontal earthquake acceleration have dominant impact on the both reinforced soil wall internal and external stabilities limit states. Also, the type of probability distribution function affects the reliability index significantly and coefficient of variation of internal friction angle has the greatest influence in the static and seismic limits states compared to the other variables.

• Journal of Korean Foot and Ankle Society
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• v.28 no.2
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• pp.60-67
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• 2024

Purpose: Sinus tarsi syndrome (STS) is caused by various pathologies. However, the exact etiology of STS remains controversial. This study evaluated the imaging and arthroscopic findings of patients who underwent surgical treatment after conservative treatment for STS failed. Materials and Methods: Between December 2014 and August 2018, 20 patients (21 cases) who underwent surgical treatment for STS were included in the study. The clinical results were analyzed using the visual analog scale (VAS) and the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot functional scale. The radiographic results were analyzed using Meary's angle, calcaneal pitch angle, and hindfoot alignment angle. The pathologic conditions of sinus tarsi were confirmed by magnetic resonance imaging (MRI) and subtalar arthroscopy. Synovitis, bone edema, and accessory anterolateral talar facet (AALTF) were evaluated on MRI. Synovial thickening, cartilage damage, interosseous talocalcaneal ligament (ITCL) and cervical ligament rupture, soft tissue impingement, AALTF, and accessory talar facet impingement (ATFI) were evaluated by subtalar arthroscopy. Results: The mean duration of symptoms was 28.7 months (4~120). All patients showed significant improvement in the VAS and AOFAS ankle-hindfoot scale. Significant improvements in hindfoot alignment angle and Meary's angle postoperatively were noted in patients who underwent medial displacement calcaneal osteotomy. MRI confirmed synovitis in all patients, AALTF in 19 cases (90.5%), and ATFI with bone edema in seven cases (33.3%). In subtalar arthroscopy, pathologic conditions were observed in the following order: synovitis in 21 cases (100%), AALTF in 20 cases (95.2%), ITCL partial rupture in nine cases (42.9%), and soft tissue impingement in seven cases (33.3%). All cases had two or more pathological conditions, and 15 (71.4%) had three or more. Conclusion: In cases of STS that do not respond to conservative treatment, a comprehensive examination of the lesions of the tarsal sinus and lesions around the subtalar joint is essential.