• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.7-12
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• 2008

In order to estimate the integrity and identify the dynamic characteristics of buried gas pipelines subjected to vehicle loads, FE analysis is performed based on the 'Highway and Local Road Design Criteria' and the 'KOGAS Guideline for Pipeline Management'. The FE model describes the current burial condition of Korea properly, and the DB-24 load model is adopted for this research. This study considers a varying velocity in the range of $40{\sim}160\;km/h$ and $P_i=8$ MPa(internal pressure) with depth cover, Z=1.5 m. Maximum stress occurs at v=80 km/h and decreases after v=80 km/h. The maximum induced stress by DB-24 loads is about 10 MPa. Under the design pressure, however, the analysis results show that API 5L Gr. X65 pipelines have sufficient integrity to withstand the vibration of vehicle loads.

• Korean Journal of Computational Design and Engineering
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• v.15 no.5
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• pp.383-392
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• 2010

The purpose of this study is to develop three Judo-doll systems for enhancement of Judo's performance. Traditional Judo training requires a human training partner. Unfortunately it is not always easy to find one. Multifunctional Judo-doll training system has therefore been developed, and is described here. The system consists of a dummy, a power generating mechanism, and kinematic links. The power-generating mechanism generates forces similar to those of a human, by adjusting deadweights and controlling powderbrake's forces. The powderbrake force is controlled by the microprocessor according to the exercise scenario. The kinetic links, which mimic a human training partner's motions, has been developed based on a $Vicon^{TM}$ system's analysis of the movement of human training partners. This mechanism whose name is "L link-wire" consists of L type links, wire, roller, and dead weight. This mechanism generates the force that leads the link to the neutral position regardless the link is pushed or pulled. The lifting mechanism that lifts the doll when the one-armed shoulder throw skill is applied is also developed. A 32-bit microprocessor controls the whole system; it reads the loadcell data, controls the electromagnetic force, and communicates with a PC via Bluetooth. The training history, including loadcell data, date, and training time, is stored in the PC for analysis. This training system can be used to enhance the Judo performance of any self training player.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.3
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• pp.75-82
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• 2016

This study analytically reviewed the behavior of steel plate concrete (SC) walls subjected to forced vibration to investigate the effects of shape and arrangement spacing of studs on the behavior spacing of studs in SC wall were carried out. From the analyses, it was noted that the damping ratio obtained from the time history analyses showed overall high value in Half-power Bandwidth method and the lowest value in Fitted Exponential Curve method. And, in half of the design strength, the damping ratio presented approximately 3.0~4.2% and, in the design strength, it was approximately 4.1~5.2%. When the developed studs were used, the damping ratio was reduced slightly and it did not show consistent results between DS1 and DS2. When the distance between the studs increases more than necessary, it was also confirmed that the natural frequency was reduced and the damping ratio was increased.

• Earthquakes and Structures
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• v.18 no.2
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• pp.147-162
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• 2020

This paper presents a novel precast energy dissipation shear wall (PEDSW) structure system that using mild steel dampers as dry connectors at the vertical joints to connect adjacent wall panels. Analytical studies are systematically conducted to investigate the seismic performance of the proposed PEDSW under sequence-type ground motions. During earthquake events, earthquake sequences have the potential to cause severe damage to structures and threaten life safety. To date, the damage probability of engineering structures under earthquake sequence has not been included in structural design codes. In this study, numerical simulations on single-story PEDSW are carried out to validate the feasibility and reliability of using mild steel dampers to connect the precast shear walls. The seismic responses of the PEDSW and cast-in-place shear wall (CIPSW) are comparatively studied based on nonlinear time-history analyses, and the effectiveness of the proposed high-rise PEDSW is demonstrated. Next, the foreshock-mainshock-aftershock type earthquake sequences are constructed, and the seismic response and fragility curves of the PEDSW under single mainshock and earthquake sequences are analyzed and compared. Finally, the fragility analysis of PEDSW structure under earthquake sequences is performed. The influences of scaling factor of the aftershocks (foreshocks) to the mainshocks on the fragility of the PEDSW structure under different damage states are investigated. The numerical results reveal that neglecting the effect of earthquake sequence can lead to underestimated seismic responses and fragilities, which may result in unsafe design schemes of PEDSW structures.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.61-67
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• 2010

Thick soft clay deposits which are generally located at the west and south coast of the Korean peninsula have complicated characteristics according to their orientation and formation history. Thus, several geotechnical problems could possibly occur when those soft clay deposits are used as foundations for marine structures. Deep cement mixing (DCM) method is one of the most widely used soft soil improvement method for various marine structures, nowadays. DCM method injects binders such as cement into the soft ground directly and mixes with the in-situ soil to improve the strength and other geotechnical properties sufficiently. However, the natural impacts induced by dynamic motions such as ocean waves, wind, typhoon, and tusnami give significant influences on the stability of marine structures and their underlaying foundations. Thus, the dynamic properties become important design criteria to insure the seismic stability of marine structures. In this study, the dynamic behavior of cemented Busan clay is evaluated. Laboratory unconfined compression test and resonant column test are performed on natural in-situ soil and cement mixed specimens to confirm the strength and strain-dependent dynamic behavior variation induced by cement mixing treatment. Results show that the unconfined compressive strength and shear modulus increase with curing time and cement content increment. Finally, the optimized cement mixing ratio for sufficient dynamic stability is obtained through this study. The results of this study are expected to be widely used to improve the reliability of seismic design for marine structures.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.3 s.18
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• pp.11-21
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• 2005

This study is performed to understand complex behavior and to investigate the rational analysis methods for seismic design of the curved bridges. To analyze the curved bridges for the seismic loadings, it is used that the finite element analysis program has the 7-dof curved beam and straight beam element. The free vibration characteristics of the curved bridges are compared with the straight bridges that have span length same as the average arc length of inside and outside girder of those. For the same case, the dynamic behavior is compared under seismic loadings. It is found that regular bridges classified by AASHTO are analyzed as if those were straight. To investigate the dynamic behavior of general curved bridges under seismic loading, the seismic loading directions and the subtended angle of curved bridges are varied.

• Journal of Korean Association for Spatial Structures
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• v.9 no.4
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• pp.49-59
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• 2009

The seismic responses of small-scale spatial frames such as school gymnasiums are usually evaluated using static analysis, although time-history analysis should be carried out to fully incorporate the dynamic responses of the structures against seismic motions. In this study, advanced static analysis procedures arc presented for school gymnasiums that will improve the performance evaluation against seismic motions. The seismic loads are approximated by equivalent static loads corresponding to the two performance levels; i.e., Levels 1 and 2 defined by the Japanese building standard. The importance of utilizing the eigenmode in the load pattern is discussed. Simple static analysis procedures are presented for evaluation of maximum vertical acceleration. It is shown that the static analysis for Level 2 input significantly underestimates the responses by dynamic analysis; however, the inelastic responses for Level 2 are shown to be successfully evaluated using the equivalent linearization that is similar to the $^{\circ}$Dmethod based on calculation of limit strength$^{\circ}{\pm}$ for building frames in Japan.

• Journal of the Korea Fashion and Costume Design Association
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• v.9 no.3
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• pp.205-220
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• 2007

In the 17th century, men's hair style showed a dramatical change to thick hair style with femineity. During the 17th century, men wore their hair longer than at any other time in the history of western culture. Men's hairs in the early 17th century were defined as short hair style influenced by ruff collar of renaissance and thick beards and moustaches During the mid 17th century, shoulder-length hair style was predominant over all classes. As hair style became long, beards and moustaches gradually declined in favour: from 1625, small neat beards, and moustaches turned up at the ends, got progressively smaller, and by 1650 the beard was only small tuft on the chin, disappearing completely by 1680. In the late 17th century, very long, thick and shiny hair got a great popularity with the gorgeous and decorative baroque costume dominated over the entire Europe. The habit of adding false hair when natural hair was deficient led to the introduction of the periwig, which became an essential part of a fashionable man's attire. Wiggery were widely used to express curled and puffed hairs more exaggerated. As the long hair style with wiggery became popular, various style of beard and moustache got smallar so that they were ended up in entire disappearance in the end of the 17th century.

• Journal of the Korea Fashion and Costume Design Association
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• v.16 no.2
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• pp.101-109
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• 2014

Bangryeong generally means rectangular collars at present. However, it is estimated that there would be Bangryeong in different shapes besides rectangular shape in ancient times, but there is no accurate evidence. The dispute on the shape of Bangryeong started with the records in Yegi(禮記) and Simui written during Zhou period, China, the oldest records on Bangryeong. However, there are no remains or paintings(pictorial data) accurately proving the different shapes of Bangryeong. While the new shape of Gokgeop(collar of Simui) was mentioned by Zhu Xi during Song period, it was not accurately verified. There are almost no literature, excavated objects or pictorial data on the shapes of Bangryeong which are not definitely identified. The shape of Bangryeong is identified to a certain extent by objects excavated or pictorial data during Yuan and Ming period. There will be definite reasons why Zhou Xibao and Hua Mei, the scholars in China, the y-shaped collar rolled on the chest among the objects excavated during Warring States Period as Bangryeong or Guryeong. Thus, this paper investigated the notes and description in Yegijeongui(禮記正義) and the records and notes during the Han period which are mentioned most frequently except Yegi among the records on Bangryeong. Accordingly, this paper identified that there are different shapes of Bangryeong except rectangular shape during the Han period. It is estimated that Bangyeong at that time had symmetric collars, the collars of Jikryeong which are not overlapped. The collar section after the neck section was straight. It was also said that Bangyeong was women's clothing. In other words, Bangyeong in the Han period suggests that the collar of Jikryeong was Bangryeong. As discussed above, Bangryeong has the long history and different meanings by period. However, it is very difficult to accurately define Bangryeong because there are almost no records on it. Nevertheless, Bangryeong will be discussed more in further study.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.2
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• pp.209-214
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• 2018

The subway, which is an urban railway, is the core of public transportation. Urban railways are always exposed to serious problems such as theft, crime and terrorism, as many passengers use them. Especially, due to the nature of urban railway environment, the scope of surveillance is widely dispersed and the range of surveillance target is rapidly increasing. Therefore, it is difficult to perform comprehensive management by passive surveillance like existing CCTV. In this paper, we propose the implementation, design method and object recognition algorithm for intelligent object recognition system in urban railway. The object recognition system that we propose is to analyze the camera images in the history and to recognize the situations where there are objects in the landing area and the waiting area that are not moving for more than a certain time. The proposed algorithm proved its effectiveness by showing detection rate of 100% for Selected area detection, 82% for detection in neglected object, and 94% for motionless object detection, compared with 84.62% object recognition rate using existing Kalman filter.