• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.231-240
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• 1998

The characteristics of cranium, vertebral column and fin supports of Acanthorhodeus gracilis were examined. The fish did not have a fontanell in cranium nor process of supraethmoid. It had double orbitosphenoids and a basioccipital process developed from anterior portion of basioccipital. It had a high and triangular dorsal process on supraoccipital. In the urohyal, hypohyal attachment was bifurcated and horizontal and vertical plate were in an elongated rhombus shape with posterior edge pointed. It had teeth of 1-rowed, 5/5 and 4 free teeth. The fish did not have a coracoid foramen on shoulder girdle. It does not have a uroneural on ural centrum. It had a long and slender posterior process of pelvic bone. It had a large and flat supraneural. The fish had 14 or 15 interneural spines, of which the 1st, 2nd, 3rd and 4th had single basiosts and the rest had double basiosts. It had 11 or 12 interhemal spines, of which the 1st, 2nd, 3rd and 4th had single basiosts and the rest had double basiosts.

• Structural Engineering and Mechanics
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• v.64 no.4
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• pp.413-426
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• 2017

Probabilistic methods are used in engineering where a computational model contains random variables. The proposed method under development: Direct Optimized Probabilistic Calculation (DOProC) is highly efficient in terms of computation time and solution accuracy and is mostly faster than in case of other standard probabilistic methods. The novelty of the DOProC lies in an optimized numerical integration that easily handles both correlated and statistically independent random variables and does not require any simulation or approximation technique. DOProC is demonstrated by a collection of deliberately selected simple examples (i) to illustrate the efficiency of individual optimization levels and (ii) to verify it against other highly regarded probabilistic methods (e.g., Monte Carlo). Efficiency and other benefits of the proposed method are grounded on a comparative case study carried out using both the DOProC and MC techniques. The algorithm has been implemented in mentioned software applications, and has been used effectively several times in solving probabilistic tasks and in probabilistic reliability assessment of structures. The article summarizes the principles of this method and demonstrates its basic possibilities on simple examples. The paper presents unpublished details of probabilistic computations based on this method, including a reliability assessment, which provides the user with the probability of failure affected by statistically dependent input random variables. The study also mentions the potential of the optimization procedures under development, including an analysis of their effectiveness on the example of the reliability assessment of a slender column.

• Applied Microscopy
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• v.41 no.1
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• pp.31-35
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• 2011

The fine structures of the sperm morphology in the Myotis daubentonii ussuriensis were observed by transmission electron microscope. The results showed that the sperm head revealed bullet shaped, the width was showed a slender more than toward the posterior region to anterior region of nucleus. The sperm head was about $4.5{\mu}m$ in length, being about $2.0{\mu}m$ in width. The nuclear length was $4.3{\mu}m$, occupied most of the sperm head. The nucleus and acrosome were separated by the apical body. The neck region was composed the basal plate, capitulum and segmented columns. The segmented columns were about 12 to 14 in number and connected with the outer dense fibers of the middle piece. The mitochondria sheath were arranged like the thread of a screw, and the total number of mitochondrial gyres were 57. The satellite fibers were observed irregularly among the outer dense fibers in the middle piece. Except the middle piece they are not observed in the principal and end pieces of the tail. In general, the tail show axoneme composed of a 9+2 microtubular pattern, and microtubules of the end piece were arranged irregularly.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.37-44
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• 2017

Due to structural characteristics, construction costs and duration of a modular system would be saved by minimizing the schedule on the job site. As such, it is crucial to develop a connection that can guarantee stiffness while allowing for simple assembling. Particularly, the mid- to high-rise construction of the modular system necessitates the securing of the structural stability and seismic performance of multi-unit frames and connections, and thus, the stiffness of unit-assembled structures needs to be re-evaluated and designed. However, evaluating a frame consisting of slender members and reinforcing materials is a complicated process. Therefore, the present study aims to examine the structural characteristics of a modular unit connection based a method for reinforcing connection brackets and hinges while minimizing the loss of the cross section. Toward this end, the study modeled the beam-to-column connection of a modular system with the proposed connection, and produced a specimen which was used to perform a cycling loading test. The study compared the initial stiffness, the attributes of the hysteretic behavior, and the maximum flexural moment, and observed whether the model acquired the seismic performance, compared to the flexural strength of the steel moment frame connection that is required by the Korean Building Code. The test results showed that the proposed connection produced a similar initial stiffness value to that of the theoretical equation, and its maximum strength exceeded the theoretical strength. Furthermore, the model with a larger ceiling bracket showed higher seismic performance, which was further increased by the reinforcement of the plate.

• Journal of the Korea Concrete Institute
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• v.22 no.3
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• pp.381-388
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• 2010

In this study, characteristics of the seismic response of the non-earthquake resistant reinforced concrete (RC) frame were identified. The test building is designed to withstand only gravity loads and not in compliance with modern seismic codes. Smooth bars were utilized for the reinforcement. Members are provided with minimal amount of stirrups to withstand low levels of shear forces and the core concrete is virtually not confined. Columns are slender and more flexible than beams, and beam-column connections were built without stirrups. Through the modeling of an example RC frame, the feasibility of the fiber elementbased 3D nonlinear analysis method was investigated. Since the torsion is governed by the fundamental mode shape of the structure under dynamic loading, pushover analysis cannot predict torsional response accurately. Hence, dynamic response history analysis is a more appropriate analysis method to estimate the response of an asymmetric building. The latter method was shown to be accurate in representing global responses by the comparison of the analytical and experimental results. Analytical models without rigid links provided a good estimation of reduced stiffness and strength of the test structure due to bond-slip, by forming plastic hinges closer to the column ends. However, the absence of a proper model to represent the bond-slip poased the limitations on the current inelastic analysis schemes for the seismic analysis of buildings especially for those with round steel reinforcements. Thus, development of the appropriate bond-slip model is in need to achieve more accurate analysis.

• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.23-34
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• 2012

In this study, stub columns subjected to concentrical and eccentrical loads were tested to check the applicability of the current local stability criteria (KBC2009, AISC2005) to 800MPa high-strength steel (HSA800). The key test variables in the concentrically loaded tests included the plate-edge restraints and the width-to-thickness ratio normalized by the yield strength of steel. Specimens made of ordinary steel (SM490) were also tested for comparative purposes. Eccentrically loaded stub column tests were conducted for a range of the P-M combinations by controlling the loading eccentricity. All the concentrically loaded specimens with non-compact and slender sections developed sufficient strengths according to the current local stability criteria. All the eccentrically loaded specimens with non-compact H sections also exhibited a sufficient P-M interaction strength that was even higher than that of compact H- section counterparts. Residual stresses were also measured by using the non-destructive indentation method to demonstrate their dependency or independency on the steel material's yield strength. The measured results of this study also indicated that the magnitude of residual stresses bears no strong relation to the yield strength of the steel material.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.67-74
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• 2010

The cases of collapse of greenhouses in rural areas have been increasing due to the unexpected heavy snow load. Studies on how to prevent the collapse of greenhouses are rare, however, and the damages are repeated annually. This studysuggests two reinforcing methods: the use of ahigh-strength tapered module, and the addition of a pre-tension tie. The high-strength tapered section is installed where the bending moment is maximum. The design of a plastic greenhouse is controlled by its strength rather than its deflection. The shape of a greenhouse resembles that of an arch system, but its actual structural behavior is the frame behavior, because it is non-continually composed of a curved element (a beam) and vertical elements (columns). This system is too weak and slender to resist a vertical load, because an external load is resisted by the moment rather than by axial force. In this study, a new method, the installation of a temporary tie at the junction of the arch and the column only during snow accumulation, is proposed. The tie changes the action of the greenhouse frame to an arch action. The arch action is more effective when the pre-tension force is applied in the tie, which results in a very strong temporary structural system during snowfall. As a result of using this high-strength tapered section, the combined strength ratio of what? decreased from 10% to 30%. In the case of the additional reinforcement with a tie, it was reduced by half.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.114-120
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• 1997

Frequencies and the types of abnormal vertebrae in the juvenile of five cyprinid fishes collected from the Kumho River during 1995 and 1996 were examined. Types of vertebral anomalies in investigated species were spinal curvature, fused vertebrae, helical sutures of cetera and abnormal vertebrae with one or two additional spines. The frequencies and the types of vertebral anomalies were different among the species. Of all the examined species, the type with one or two additional spines showed the highest frequencies, 11.72~12.11%. The frequencies of fused vertebrae was 4.45~7.68%. Thes two types of vertebral anomalies were observed in all species. Among the several types of fused vertebrae, the frequencies of double fused vertebrae were higher than those of other types. Also, the incidence of fused vertebrae located in the caudal region of vertebral column was much higher than that in other regions. The percentages of spinal curvature and helical sutures of vertebrae in the investigated species were 0.02~0.15% and 0.02%, respectively. Among the examined specimens, vertebral anomalies include fused vertebrae and one or two additional spines were shown in the three species, Korean slender gudgeon (Squalidus gracilis majimae), False dace (Pseudorasbora parva) and Crucian carp (Carassius auratus). In addition to the two vertebral anomalies, spinal curvature was shown in the Korean gudgeon (Squalidus chankaensis tsuchigae). Dark chub (Zacco temmincki) had fused vertebrae, one or two additional spines, spinal curvature, and helical sutures of vertebrae. This species has the most variable vertebral anomalies. Frequencies of fused vertebrae and one or two additional spines in the all tested fishes were not related with their standard lengths measured. However, spinal curvature and helical sutures of vertebrae were shown only in the specimens smaller than 20mm in standard length.