• Smart Media Journal
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• v.4 no.4
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• pp.64-69
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• 2015

In this paper, we have proposed a tapered slot antenna for UWB communication system. The tapered slot antenna has directional radiation and broad bandwidth. Proposed tapered slot antenna is designed using Ansys Inc. HFSS and its VSWR, return los, and radiation pattern is analyzed. Operating band of the antenna were satisfied -10 dB S11 and $VSWR{\leq}2$ in 2.7 ~ 4.8 GHz band. The radiation pattern of the antenna is showed in E-plane (YZ plane) and the H-plane (XZ plane) and the highest gain of 7.3 dBi is seen at 4.5 GHz. Therefore, proposed tapered slot antenna has wide bandwidth characteristic and directional for location awareness.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.8
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• pp.1-6
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• 1999

The only transmission characteristics in frequency domain is considered when using the tapered transmission line for wide-band impedance matching in MCM and MIC designs. In this paper, the distortion of an electrical pulse with rise/fall time resulting from dispersion and reflection as it propagates along a tapered microstrip line is investigated, and the delay time and distortion rate with respect to input and load impedances are analyzed on triangular and exponential tapered lines. A dispersion model of the phase constant proposed by Kirschning-Jansen is used to meet the frequency, accuracy and microstrip parametric requirements. The triangular tapered line shows both shorter delay time and higher distortion rate than those of the exponential tapered line. Furthermore, the amplitude of signal reflected from load point is calculated in time domain.

• Structural Engineering and Mechanics
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• v.66 no.1
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• pp.125-138
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• 2018

This paper proposes a transfer matrix method for the bending vibration of two types of tapered beams subjected to axial force, and it is applied to analyze tapered beams with an edge or multiple edge open cracks. One beam type is assumed to be reduced linearly in the cross-section height along the beam length. The other type is a tapered beam in which the cross-section height and width with the same taper ratio is linearly reduced simultaneously. Each crack is modeled as two sub-elements connected by a rotational spring, and the method can evaluate the effect of cracking on the desired number of eigenfrequencies using a minimum number of subdivisions. Among the power series available for the solutions, the roots of the differential equation are computed using the Frobenius method. The computed results confirm the accuracy of the method and are compared with previously reported results. The effectiveness of the proposed methods is demonstrated by examining specific examples, and the effects of cracking and axial loading are carefully examined by a comparison of the single and double tapered beam results.

• International Journal of High-Rise Buildings
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• v.9 no.4
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• pp.361-368
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• 2020

The authors developed a new type of steel slit shear wall (SSSW) having the function of structural condition assessment through visually inspecting the out-of-plane deformation of the designed tapered links subjected to lateral deformation. To facilitate its practical application, this paper studies how to design dimensions of the tapered links. Two parameters, the width-to-thickness ratio of the tapered links and steel yield stress, were studied. The performance of structural condition assessment was affected by both parameters with the width-to-thickness ratio being the controlling one. Through both numerical and experimental study, the designed width-to-thickness ratio of tapered links for different levels of structural condition assessment was established considering the effect of different steel grades used. In practice, the dimensions of tapered links can be determined following the design equation provided. Finally, a design procedure for the proposed SSSW system is provided.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.4
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• pp.492-505
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• 2007

Statement of problem: An orthodontic miniscrew implant has been used as a skeletal anchorage for orthodontic treatment. However, any relation among the influence of the cortical bone, morphologic differences of orthodontic miniscrew implants and new bone formation hasn't been made clear yet. Purpose: The purpose of this study was to evaluate whether the orthodontic miniscrew implant could work as an intraoral skeletal anchorage immediately and stably for orthodontic treatment after insertion of it. Material and methods: Two types of orthodontic miniscrew implants were used in this experiment; tapered type and straight type. One hundred and sixty eight orthodontic miniscrew implants were inserted into the tibiae of 21 rabbits and sacrificed on 3, 7, 11, 14, 21 and 28days later after insertion of them to study removal torque values and histologic and histomorphometric analyses. Results: The results were as follows. 1. The removal torque values of the tapered type were higher than those of the straight type in all groups(p<0.05). 2. There wasn't any distinguishing differences between the tapered type and the straight type about the new bone formation percentage. 3. The removal torque values for both the tapered type and the straight type were gradually decreased at early stages of the test but started to increase at the 7 days group of the straight type and the 11 days group of the tapered type. 4. New bone formation percentage was increased gradually for both the tapered and the straight types as time passed(p<0.05). 5. It was found that the tapered type showed lower values in the cortical bone about both the maximum equilibratory stress distribution and the maximum principal stress distribution than the straight type in linear finite elements analysis. Conclusion: According to the research, the removal torque values were decreased at 7 days group of the tapered type and 11 days group of the straight type after the insertion of the orthodontic miniscrew implants in tibiae of rabbits. Considering the human bone activity, it is better to apply the orthodontic force $3{\sim}4$ weeks later than to apply it immediately after the insertion of orthodontic miniscrew implants. Considering that general orthodontic force is about $250{\sim}500$ grams, the tapered type can be worked as a stable skeletal anchor age in an orthodontic treatment even if the orthodontic force is applied on it immediately after the insertion of it.

• Journal of the Korean Geotechnical Society
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• v.24 no.12
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• pp.13-22
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• 2008

Fourteen calibration ehamber tests were performed using one cylindrical and two tapered piles with different taper angles to investigate the changes of the bearing capacity of tapered piles with soil state and taper angle of piles. The results of calibration chamber tests show that the ultimate base resistance of tapered piles increases with increasing mean stress and relative density of soil. It also increases with increasing taper angle for medium sand, but with decreasing taper angle for dense sand. The ultimate shaft resistance of tapered piles increases as vertical and horizontal stresses, relative density and taper angle increase. Based on the results of model pile load tests, a new design method with shape factors for estimation of the bearing capacity of tapered piles is proposed considering the effect of soil state and taper angle on bearing capacity of tapered piles. In order to check the accuracy of predictions calculated using the new method, middle-scale field pile load tests were also conducted on cylindrical and tapered drilled shafts in clayey sand. Comparison of calculated values with measured ones shows that the new design method produces satisfactory predictions tor tapered piles.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.2
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• pp.73-78
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• 2017

Objective: Sperm morphology plays an important role in infertility, especially in cases of defects in the heads of spermatozoa. Tapered-head or elongated-head spermatozoa are examples of morphological abnormalities. The aim of this study was to compare the semen parameters, levels of protamine deficiency, and frequency of apoptosis between patients with normozoospermia and those with teratozoospermia with tapered-head spermatozoa. Methods: Fifty-two semen samples (27 patients with tapered-head sperm and 25 fertile men) were collected and semen analysis was performed according to the World Health Organization criteria for each sample. Protamine deficiency and the percentage of apoptotic spermatozoa were evaluated using chromomycin A3 (CMA3) staining and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assays, respectively. Results: Sperm concentration, motility, and normal morphology in the tapered-head spermatozoa (cases) were significantly lower than in the normozoospermic samples (controls). CMA3-reactive spermatozoa (CMA3+) in the case group were more common than in the controls. Apoptotic spermatozoa (TUNEL-positive) were significantly more common in the cases than in the controls. Conclusion: This analysis showed that tapered-head spermatozoa contained abnormal chromatin packaging and exhibited a high rate of apoptosis, which can be considered to be an important reason for the impaired fertility potential in teratozoospermic patients with tapered-head spermatozoa.

• Journal of the Korean Society for information Management
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• v.30 no.4
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• pp.111-131
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• 2013

This study describes the meaning of and the formula for Kor-$h_T$, which is a modified index built on the tapered h-index by applying 'the ranking according to the number of citations of journals'. This study evaluated the de-duplication rate of index values of Kor-$h_T$ and analyzed the change in the correlation between the index values and evaluation elements using the Korea Citation Index data from 2008 to 2010. Kor-$h_T$ is compared with h-index, tapered h-index, and IF. As a result, Kor-$h_T$ appeared to be superior to other indexes on de-duplication rate. It is also shown that there is a very strong positive correlation between the evaluation elements, the number of citations and the number of articles of journals, and the index values of Kor-$h_T$.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.361-368
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• 2014

Modal properties for tapered cantilever pipe-type beam is identified by applying the boundary conditions to a general solution for tapered beam. A bending stiffness for cracked beam is constructed based on an energy method for tapered cantilever thin-walled pipe, which has a through-the-thickness crack, subjected to bending. Then the natural frequencies and mode shapes of a tapered cantilever thin-walled cracked pipe are identified. It can be found that the phenomenon of the bending stiffness distribution along the beam length of the cracked beam is quite reasonable, the natural frequencies are decreased as the crack sizes are increased, and the mode shapes are changed due to the crack. This results may be used to the vibration-based crack identification for the tapered cantilever pipe-type tower structures.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.548-556
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• 2013

A tapered production tubing with two different inner diameters has been suggested to increase production rates. In this research, various tapered tubing combinations are taken into account and possible tubing combinations are proposed to satisfy each objective. In previous studies, production enhancement was the main goal. However, this research also considers flow stability by analyzing tubing pressure traverse, liquid holdup, and operating conditions. For a reservoir assumed in this research, a tapered tubing of, 4.5 inch inner diameter(ID) and 2000 ft in length in the lower part and 5.5 inch ID and 8000 ft in the upper part, shows the highest net present value. Compared to a mono tubing, tapered tubings enable various tubing designs because they have smaller differences in frictional pressure loss. It is important to maintain low liquid holdup to prevent liquid loading. Smaller ID of tapered tubing in the lower part enables to achieve the object. In conclusion, it is identified that various tubing designs are achievable from the analyses of overall production operations depending on purposes specified.