• Applied Microscopy
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• v.40 no.3
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• pp.169-176
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• 2010

Black molly (Poecilia sphenops) and sailfin molly (Poecilia latipinna) are a teleost belonging to Poeciliidae. The spermatogenesis between two species were investigated by light and electron microscope. The whitish testes of both black molly and sailfin molly were located between intestine and air bladder. The size of testis was major axis 7 mm, minor axis 2 mm. The testis contained numerous testicular cysts. In both black molly and sailfin, primary spermatocytes were comparatively large ellipsoidal, and mitochondria showed a marked development. The secondary spermatocyte was smaller than that of primary spermatocyte, highly condensed according to their development. The nucleus with electron-dense was round shape and flagella started to be formed. In spermiogenesis, chromatin was more condensed. The mitochondria were rearranged along the tail. The number of mitochondria was 2 to 4 in cross section and 8 to 10 in longitudinal section. The head of mature sperm was long cone shape and had not acrosome. The microtubules of flagella were arranged 9+2 structure. Also, the tail of sperm have lateral fins. In conclusion, spermatogenesis and sperm morphologies of these two species were same. These morphological similarity seems to be an indication of the Poeciliidae.

• Journal of Fashion Business
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• v.12 no.2
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• pp.87-99
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• 2008

This study aims to classify lower trunk body types of Chinese men in their middle age (30s and 40s) and suggest the standard for them to design slacks pattern. Mollison's relation deviations were used to analyze the direct measurement items in this research compared to those of Size Korea 2004. Though Korean middle-aged men were higher in most items than Chinese counterparts, all items except mid-thigh circumference and side hip length were merely within the range of ${\pm}1\sigma$. According to the results of size classification by absolute values, factor analysis extracted to 2 factors(horizontal size of lower body and vertical size of lower body), and cluster analysis brought about 3 types(type1: tall and thin trunk (36.9%), type 2 : normal height and thick trunk(45.5%), and type 3 : short and normal trunk(17.6%) with some significant differences among them. Also, the results of shape classification by index values, they were extracted 4 factors (waist-hip flatness, waist-hip cross section, vertical waist-groin and hip-surface length) by factor analysis and revealed 3 types(type 1: different waist-hip width, thick, long waist, long upper hip, and short hip-surface length(27.8%), type 2 : different waist-hip width, flat, short upper hip, high hip and groin, and average hip-surface length(29.4%), and type 3: small waist-hip width, thick, average upper hip, and short hip-surface length (42.8%)) with significant differences among them by cluster analysis. The results of standard body types by shape-size combination, 19subjects(10.16%) under these values are regarded as standard body types. Significance was not seen in all items in the t-test results between the total group and the standard group. The latter had lower variation coefficients and smaller individual differences than the former. However, in-depth research is required for generalization since this research is limited to a small number of subjects in Ningbo of Zhejiang.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.520-525
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• 2019

Mines are an important infrastructure for securing resources, but safety problems can arise in the course of operation. Recently, the mining process is very complicated due to the large scale and mechanization. Therefore, it is necessary to construct accurate geospatial information on mine for systematic and safe mine operation. The geospatial information construction using the existing total station has a disadvantage that a lot of work time is required because the target must be collimated and measured. In this study, the data of the mines were acquired with the total station and the 3D laser scanner, and the mine spatial information was constructed by using the shape based registration method. By using the static scanner data of some area applying the reference point surveying result of the total station, it was possible to construct the accurate result on the wide area acquired by the mobile scanner effectively. Also, the accuracy of the constructed geospatial information was evaluated and the deviation of mean 0.083m was shown. Point cloud products constructed through the research can contribute to the efficiency improvement of mine management by enabling quantitative analysis such as visualization of mine shape, distance, area and slope, and automation of drawing creation for cross section shape.

• Journal of the Korean Institute of Gas
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• v.26 no.2
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• pp.49-55
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• 2022

According to reinforce environmental regulations, coal power plants have used selective catalytic reduction using ammonia as a reducing agent to reduce the amount of nitrogen oxide generation. The purpose of the present study was to derive a mixing device for effectively mixing dilute air and ammonia in the ammonia mixing pipe by performing computational fluid dynamic analysis. The mixing effect was compared by analysing the %RMS of ammonia concentration at the down stream cross section in the mixing pipe and the 16 outlets based on the case 1-1 shape, which is an existing mixing pipe without a mixing device. The mixing device was performed by changing the positions of a square plate on the downstream side of the ammonia supply pipe and an arc-shaped plate on the wall of the mixing pipe. In the case of the existing geometry(Case 1-1), the %RMS of ammonia concentration at the 16 outlets was 29.50%. The shape of the mixing device for Case 3-2 had a square plate on the downstream side of the ammonia supply pipe and an arc plate was installed adjacent to it. The %RMS of ammonia concentration for Case 3-2 was 2.08% at 16 outlets and it could be seen that the shape of Case 3-2 was the most effective mixing shape for ammonia mixing.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.503-514
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• 2006

FBG sensors are capable of measuring the strain of structures easily and more durably than electric resistance gauges. Thus, many researches are dedicated to the application for the response monitoring or non-destructive evaluation of structures using FBG sensors. Additionally, the measured strains at the top and bottom of a cross-section can be transformed into the curvature of the section, which can be used to calculate its vertical displacement. Hence, this study aims to measure the dynamic strain signals of a steel section simply supported beam and to estimate the dynamic displacement from the strain signals, after which the estimated displacement is com pared with the measured displacement. The dynamic characteristics (natural frequency, damping ratio and mode shape) of the beam are predicted from both the estimated and measured displacement signals, and from the strain time history of the FBG sensors. The predicted properties are compared with those of an analytical model of the beam. The estimated displacement. However, the predicted dynamic properties from both the estimated displacements and the measured strains are well-correlated with those from the measured displacement. It is therefore appreciated that the estimation of the dynamic properties of FBG sensor signals is reasonable. Especially, the strain signal of the FBG sensor was amplified at a higher-frequency region in comparison with the displacement estimation with higher-mode properties.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.1
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• pp.44-53
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• 2018

The WHtR (waist to height ratio) and ABSI (a body shape index) are indicators that reflect abdominal obesity. This study examined the insulin resistance and metabolic syndrome prediction ability of ABSI and WHtR. In this study, 4,395 people aged 20 years or older, who underwent physical examinations at a General Hospital in Gyeonggi-do from January 2017 to September 2017 were assessed on a cross section survey. Metabolic syndrome was defined according to the criteria of the AHA/NHLBI. Insulin resistance was judged to be insulin resistance when the HOMA-IR value was 3.0 or more. Both men and women showed a stronger correlation between WHtR and the metabolic risk factors than ABSI. The AUC value of WHtR and ABSI was 0.849 and 0.676, respectively (p<0.001). The AUC value of WHtR and ABSI for predicting insulin resistance was 0.818 and 0.641, respectively (p<0.001). In conclusion, the ABSI has low predictive power of insulin resistance and metabolic syndrome whereas the WHtR has good predictive power for metabolic syndrome and insulin resistance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.697-704
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• 2017

High-Performance Fiber-Reinforced Cement Composites (HPFRCC) has outstanding durability, and has attracted interest because of its ductility and development of strength, which allows a reduction of the self-weight of a structural member by substantially decreasing the cross section. Therefore, the present study aimed to improve the economic efficiency of HPFRCC by examining experimentally the flexural performance considering various characteristics of the steel fiber. To find an efficient fiber reinforcement method, the flexural performance was evaluated for different shapes, aspect ratios, and volume ratios of the steel fiber. Straight, hooked, and twisted fiber configurations were considered by adopting a fiber length longer than the usual 13 mm. The test results showed that HPFRCC reinforced by 19.5 nun-long straight fibers with a volume fraction of 1.5% shows better flexural performance than that reinforced by 13 mm-long straight fibers with a volume fraction of 2.0%. Consequently, HPFRCC with enhanced economic efficiency can be produced by adopting a reduced amount of steel fiber.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.2
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• pp.109-117
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• 2015

Aircraft needs an inlet duct to supply the airflow to engine face. A fighter aircraft that requires low radar observability has to hide the engine face in the fuselage to reduce the Radar Cross Section(RCS). Therefore, the flow path of the inlet duct is changed into S-shape. The performance of the aircraft engine is known to be influenced by the shape and the centerline curvature of the S-Duct. In this study, CFD analysis of the RAE M 2129 S-Duct has been performed to investigate the influence of aspect ratio of inlet geometry. The performance of the S-Duct is evaluated in terms of the distortion coefficient. To simulate the flow under adverse pressure gradient better, $k-{\omega}SST$ turbulence model is employed. The computational results are validated with the ARA experimental data. The secondary flow and the flow separation are observed for all computational cases, while the semi-circular geometry has been found to produce the best results.

• Korean Journal of Plant Taxonomy
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• v.44 no.2
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• pp.119-131
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• 2014

A comparative study of leaf anatomy in tribe Sorbarieae (Adenostoma, Chamaebatiaria, Sorbaria, Spiraeanthus) including one related genus Lyonothamnus was carried out using light microscopy. Anatomical characteristics of the leaf blade and midrib were described and taxonomically evaluated. The anatomical characters which described in this study are as follows: thickness of leaf midrib, blade in cross section, cuticle, epidermal cell, stoma, trichome, mesophyll, crystal, main vasculature type. All features were compared and the vascular patterns of midrib were distinguished two types. - Type 1: Trace tripartite (Adenostoma), Type 2: Trace continuous, subtype 2A: flat arc (Chamaebatiaria, Spiraeanthus), subtype 2B: U-shape arc (Lyonothamnus, Sorbaria). In conclusion, some of leaf anatomical characters (e.g., cuticle, epidermal cell, trichome, mesophyll, main vasculature type) can be useful for diagnostic features. Hypostomatic type, dorsiventral mesophyll, Ushape vasculature type would constitute a major characters for genus Sorbaria in Sorbarieae. The detailed anatomical description of studied taxa is provided, and its systematic importance is also briefly discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.203-210
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• 2019

A recent earthquake on the Korean Peninsula caused much damage to masonry buildings, and research on performance evaluation has been underway. A masonry building is generally constructed using wet construction and is affected by temperature, which reduces the efficiency of the construction. In this study, we propose a dry construction technique for assembling concrete blocks without using mortar and evaluated its performance through experimental and analytical research. To evaluate the performance, experiments were carried out for the prismatic compressive strength, direct terminal strength, and diagonal tensile strength of the dry construction wall. The adequacy of the cross section shape was also reviewed through FEM analysis. The results show that the compressive strength and diagonal tensile strength could exert a certain intensity or higher. Furthermore, the H-type module of a key block acted as a shear key for the entire concrete block, which resulted in excellent shear strength performance. In addition, the shape and thickness of the main block have a major effect on the strength performance of each block. Therefore, an optimal shape and the proposed dry construction method could be applied to replace the wet method by studying the construction or seismic performance of the proposed method.