• Title/Summary/Keyword: short length

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Critical Length Estimation of Counterpoise Subjected to Lightning Stroke Currents

  • Lee, Bok-Hee;Yoo, Yang-Woo;Kim, Jong-Ho
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.8
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    • pp.106-113
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    • 2011
  • The conventional grounding impedance of a counterpoise is calculated as a function of the length of the counterpoise by use of the distributed parameter circuit model with an application of the EMTP(Electromagnetic Transient Program). The adequacy of the distributed parameter circuit model is examined and verified by comparison of the simulated and the measured results. The conventional grounding impedance of the counterpoise is analyzed for the first short stroke and subsequent short stroke currents. As a result, the simulated results show that the minimum conventional grounding impedance gives at a specified length of the counterpoise. The shorter the time taken to reach the peak of injected currents, the shorter the length of the counterpoise having the minimum conventional grounding impedance. We also present the critical lengths of the counterpoise for short stroke currents as a function of soil resistivity. Based on these results, it is necessary to compute the length of the counterpoise in a specified soil resistivity which satisfies both the low conventional grounding impedance requirement whilst also providing a suitable ground resistance in order to obtain an economical design and installation of the counterpoise.

Lower body shape classification of male university students

  • Cha, Su-Joung
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.3
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    • pp.135-141
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    • 2019
  • The purpose of this study was to analyze the direct measurement data of 20-25 years male university students of 7th Size Korea data and to characterize and to type the body shape of lower body. It was to provide basic data for male university students' pants pattern production. The lower body part consisted of the 'horizontal factor' of the lower body composed of circumference, thickness, width, and 'vertical factor' of the lower body composed of the length and height. This was consistent with the analysis of the body shape factor of the lower half of male adolescents. The lower body shape was classified into four types. Type 1 was thick and relatively long in the lower body and was named 'thick long leg'. Type 2 was named 'short bird legs' because the lower body was thin and relatively short. Type 3 was relatively thin and long, so the lower body was named 'long crane leg'. In Type 4, the lower body was relatively thick and short, which means 'short pillar leg'. In the case of 20-25 year-old male university students, they have different body shapes depending on the girth and length of the lower half of their body as they have reached adulthood. Therefore, it would be necessary to provide a sales system that allows the repair of the length of the pants to be facilitated, and the length of the pants to be repaired when the pants are selected according to the circumference. Future studies will need to classify the body shape according to angle and flatness.

An Experimental Study on Short Circuit Characteristics by the Interior Wiring Length (옥내배선 길이에 따른 단락 특성의 실험적 연구)

  • Song, J.Y.;Kim, J.P.;Cho, Y.J.;Choi, D.M.;Oh, B.Y.;Kil, G.S.
    • Journal of the Korean Society of Safety
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    • v.27 no.4
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    • pp.38-42
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    • 2012
  • This paper describes electrical fire on residential environment such as apartment and detached house caused by defect of interior wiring. We carried out experimental study on short circuit characteristics by the interior wiring length. We were measured arc current, arc energy and interrupting time of earth leakage current circuit breaker(ELB), when an interior wiring break out short circuit in residential environment. From the experiment results, the longer of the interior wiring, the magnitude of arc current decreased and the interrupting time of ELB increased. When applied the A maker's ELB, the strength of arc current and interrupting time of ELB was 254 A and 245 ms respectively at 30 m interior wiring length. In 3 m interior wiring length, arc current and interrupting time was 716 A and 4.24 ms respectively. Arc energy was dependent on the magnitude of arc current and the interrupting time of ELB, the longer the interrupting time, arc energy increasing. In this paper, minimum arc energy was 277 J using C maker's ELB and 3 m interior wiring length(arc current 283 A, interrupting time of breaker 6.28 ms). Therefore in the residential environment, short circuit caused by defect of the interior wiring lead to electrical fire.

Body type characteristics and classification of short adult women under 155cm (155cm 미만 키 작은 성인여성의 체형 특성 및 유형화)

  • Uh, Mi-Kyung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.20 no.3
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    • pp.15-26
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    • 2018
  • The purpose of this study is to understand the characteristics of body types of adult woman under 155cm in height. To do this, direct measurement data showed that only 660 women aged 20~69 years old and under 155cm tall were classified, and their body type characteristics were analyzed. There are 51 body measurement items used in the analysis. The results of the study are as follows: As a result of the comparison of the body size of all adult women and women under 155cm, it was seen that short women were smaller than the all women, and were flattened with a slightly plump and bendless body. Factor analysis was performed to classify the body type of short women. Six factors including body size, body height, shoulder length and width, waist back length, hip length, and shoulder angle were measured. The results of cluster analysis, using factor scores, were classified into three types. Type 1 is taller among short women and slightly slimmer, and is an A-shape. Type 2 has the largest BMI and was the middle stature among short women It is the most obese body type and is an H-shape. Type 3 is short and plump, with a poor hip and is a Y-shape. As a result of crossover analysis, there was a difference in the body type characteristics of each age group. After all, the body type of the short adult women under 155cm was clearly different from those of all adult women, there was also a difference in the body type among short adult women.

Experimental and numerical study on performance of long-short combined retaining piles

  • Xu, Chang J.;Ding, Hai B.;Luo, Wen J.;Tong, Li H.;Chen, Qing S.;Deng, Jian L.
    • Geomechanics and Engineering
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    • v.20 no.3
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    • pp.255-265
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    • 2020
  • Laboratory tests are conducted to investigate the performance of retaining system with different combinations of long-short piles. Numerical analysis implemented using ABAQUS are verified by comparing numerical results with measured data. By performing numerical studies, the horizontal displacement of piles, heave of excavation bottom and bending moment of pile for various pile system with different pile lengths are investigated. Results show that long piles share higher bending moments than short piles. The increase in the number of short piles leads to a slight increase in the heave at excavation bottom for long-short pile retaining system. Retaining system with different long and short pile combinations have greater effects on the horizontal displacement of pile above the excavation bottom, compared to its counterparts below excavation bottom. For a given length of long pile, the bending moment and displacement of piles increase with the decrease in length of short piles, while the increasing rate of maximum moment of retaining pile system is insignificant. Results highlight that a reliable and economical pile retaining system can be designed by optimizing the number and length of short piles, provided that the working performance of retaining structures above excavation bottom meets the design requirement in practice.

Design of a compact and broadband PIFA using an additive short-circuit plate (추가 단락판을 이용한 소형 및 광대역 특성의 PIFA(Planar Inverted F Antenna) 설계)

  • 오경진;한영태;최재훈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.8A
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    • pp.591-597
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    • 2003
  • In this paper, a compact and broadband PIFA(Planar Inverted F Antenna) which has an additive short-circuit plate along the patch length was designed. For more compact PIFA short-circuit Plate along the patch width is reduced and an additive short-circuit plate along the patch length is used to broaden the bandwidth. The effect of an additive-short-circuit plate along the patch length was verified in single band PIFA and also verified in dual-band PIFA. The commercial software, IE3D, was used to design a PIFA and its performance was verified by comparing simulated results with measurement results.

Experimental research on seismic behavior of steel reinforced high-strength concrete short columns

  • Zhu, Weiqing;Jia, Jinqing;Zhang, Junguang
    • Steel and Composite Structures
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    • v.25 no.5
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    • pp.603-615
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    • 2017
  • This experimental research presents the seismic performance of steel reinforced high-strength concrete (SRHC) short columns. Eleven SRHC column specimens were tested under simulated earthquake loading conditions, including six short column specimens and five normal column specimens. The parameters studied included the axial load level, stirrup details and shear span ratio. The failure modes, critical region length, energy dissipation capacity and deformation capacity, stiffness and strength degradation and shear displacement of SRHC short columns were analyzed in detail. The effects of the parameters on seismic performance were discussed. The test results showed that SRHC short columns exhibited shear-flexure failure characteristics. The critical region length of SRHC short columns could be taken as the whole column height, regardless of axial load level. In comparison to SRHC normal columns, SRHC short columns had weaker energy dissipation capacity and deformation capacity, and experienced faster stiffness degradation and strength degradation. The decrease in energy dissipation and deformation capacity due to the decreasing shear span ratio was more serious when the axial load level was higher. However, SRHC short columns confined by multiple stirrups might possess good seismic behavior with enough deformation capacity (ultimate drift ratio ${\geq}2.5%$), even though a relative large axial load ratio (= 0.38) and relative small structural steel ratio (= 3.58%) were used, and were suitable to be used in tall buildings in earthquake regions.

The Hierarchy of Images according to Construction Factors of the Flared Skirts

  • Lee, Jung-Soon;Han, Gyung-Hee
    • Journal of Fashion Business
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    • v.13 no.6
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    • pp.137-146
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    • 2009
  • This study analyzed hierarchy of image for visual evaluation of flare skirt. This study analyzed expression words about flare skirt with frequency data of image expression words with different length and volume of flare. Stimuli for the study were set to be 4 different volume of flare ($90^{\circ}$, $180^{\circ}$, $270^{\circ}$, $360^{\circ}$) and 3 different length of skirt(48cm, 58cm, 68cm). Stimuli were made by using I-Designer which is Virtual Sewing System. From simulation of flare skirt, the subjects were asked to write down suggested adjective freely and selected 210 adjectives. With this, we chose total 38 adjectives considering frequencies in the pre-study. And we analyzed the combination process of expression words according to construction factor of flare skirt and hierarchy of image from dendrogram which was resulted by hierarchical cluster analysis. 'Feminine' got high score in all 12 flare skirt. When the skirt was short, it was vivid, and as the skirt got longer, ordinary and pure image showed. Also, as the volume of flare got larger, the average of visual effect was higher than visual image. Visual hierarchy construction according to construction factors of flare skirt could be divided into visual image and visual effect, and visual image was shown to be form 'A type - large volume of flare and short skirt length', 'H type-small volume of flare and short skirt length' and 'X type - large volume of flare and long skirt length'.

A novel vertical directional coupler with polarization independent very short coupling lengths (편광에 무관한 매우 짧은 결합 길이를 가지는 새로운 수직 방향성 결합기)

  • 정병민;김부균
    • Korean Journal of Optics and Photonics
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    • v.14 no.4
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    • pp.359-364
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    • 2003
  • We propose a novel vertical directional coupler with polarization independent very short coupling lengths using the double-sided deep-ridge waveguide structure which could be implemented using double-sided process to polarization insensitive deep-ridge waveguide structures and investigate the effect of various structure parameters on the coupling length. Variation of coupling length for the variation of the waveguide width is smaller than that for the variation of the core thickness. Coupling length decreases as the inner cladding layer thickness and the core thickness decrease. The waveguide width with the polarization independent coupling length decreases as the inner cladding layer thickness decreases for the same core thickness and the core thickness decreases for the same inner cladding layer thickness.

The Analysis of Dynamic Foot Pressure on Difference of Functional Leg Length Inequality (기능적 하지길이 차이에 따른 동적 족저압의 분석)

  • Gong, Won-Tae;Kim, Joong-Hwi;Kim, Tae-Ho
    • The Journal of Korean Physical Therapy
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    • v.21 no.4
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    • pp.43-49
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    • 2009
  • Purpose: This study examined the dynamic peak plantar pressure under the foot areas in those with a functional leg length inequality. Methods: The dynamic peak plantar pressure under the foot areas in an experimental group with a functional leg length inequality (n=20) and a control group (n=20) was assessed a using the Mat-Scan system (Tekscan, USA). The peak plantar pressure under the hallux, 1st, 2nd, 3-4th and 5th metatarsal head (MTH), mid foot, and heel was measured while the subject was walking on the Mat-Scan system. Results: The experimental group had significantly higher peak plantar pressure under all foot areas when the dynamic peak plantar pressure in the short leg and long leg sides was compared. The control group had a significantly higher peak plantar pressure under the 1st, 2nd, 3-4th, and 5th MTH when the dynamic peak plantar pressure in the short leg and long leg sides were compared. The experimental group showed a significantly larger difference in the dynamic peak plantar pressure under the hallux, 1st, 2nd, 3-4th and 5th MTH, mid foot and heel than the control group. Conclusion: A functional leg length inequality leads to an increase in the weight distribution and dynamic peak plantar pressure in the side of the short leg.

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