• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1800-1802
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• 1998

The Pohang Light Source (PLS) is a third generation 2 GeV synchrotron machine. An injection kicker modulator is positioned in the PLS storage ring tunnel. The kicker modulator is driving four kicker magnets simultaneously. The kicker magnets produce magnetic field to deflect the stored beam orbit in the storage ring closer to the injected beam from the PLS beam transfer line. The injected beam then falls into the storage ring beam dynamic aperture. The current kicker modulator was upgraded and installed on August 1995. Since then, the kicker modulator has shown very reliable and stable performance. The kicker modulator specifications are ${\sim}6.0{\mu}s$ full width, ${\sim}24$ kA peak current, and 10 Hz repetition rate. Output current waveform is a half sinusoid. Two thyratron switches(EEV CX-1536AX) are used in the kicker modulator. Total accumulated thyratron heater run hour is about 15,000 hours as of May 1998. Measurement result of spatial magnetic field distribution in the kicker magnet shows good uniformity.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.421-422
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• 2017

The kicker modulator was upgraded and installed in 1995. The PLS-II injection kicker modulator is configured with series resonant circuit. A total of four kicker magnets are used to distribute the normal storage ring beam orbit toward the septum magnet wall. Only one kicker modulator is used to drive the four kicker magnets. It is not adjust the current magnitude and timing of magnets. During the kicking, the beam has oscillation of 2 mm horizontal direction and $200{\mu}m$ vertical direction in present injector system. Our goals is to decrease the oscillation less than $300{\mu}m$. To give balanced current for all four magnets and to have precise timing between magnet current, we have plan to divide kicker power supply into four individual power supply. In this paper, the design of new individual kicker power supply and Fabrication of the new injector system is presented.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.307-308
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• 2019

The Pohang Light Source (PLS) - II is a 3 GeV third-generation synchrotron radiation facility. To inject electron beam from LINAC, a kicker modulator system and kicker magnets are installed in the PLS-II storage ring tunnel. The injected beam then falls into the storage ring beam dynamic aperture. This paper describes the design and implementation of the solid-state kicker modulator for PLS-II. The solid-state kicker modulator is consisted of high voltage solid state switch stacks. the technical considerations of the solid-state switch stacking for kicker modulator is discussed. The achieved capability of the solid-state kicker modulator demonstrates that is fulfills the design requirement of providing half-sine pulsed current of 10kA (peak), 6us (Base-width), with jitter < 2ns (Standard deviation). simulation and experimental results are presented to demonstrate the performance of the solid-state kicker modulator.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1779-1781
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• 1997

The 2.0 GeV Pohang Light Source (PLS) is consisted of a full energy Linac and a storage ring. Four kicker magnets are installed in the storage ring tunnel to move the stored beam orbit in the storage ring closer to the injected beam from the beam transfer line. The injected beam then falls into the storage ring beam dynamic aperture. A kicker magnet modulator drives all four kicker magnets to maintain field balance and also synchronized kick of the beam. The kicker modulator can handle 2 GeV full energy beam. The kicker magnet modulator is installed in the storage ring tunnel and under stable operation. Specification of the kicker magnet modulator is ${\sim}6.0{\mu}s$ pulse-width, 200 ns flat-top width with ${\pm}0.2%$ regulation, ${\sim}24\;kA$ peak current, and 10 Hz repetition rate. Two thyratron switches (EEV CX-1536AX) are used in the system. In this article, design, and experimental results of the kicker magnet modulator are discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.801-813
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• 2017

Passive force acting on the kicker block used to support a raker is different dependent on soil's type. The passive force incorporating a factor of safety is considered for design of the retaining wall. However, an actual passive force developing on the kicker block is overestimated and it may lead to an unsafe design. In this study, the actual passive forces acting on the kicker block in soil ground are evaluated using 3-D Finite Element Program, PLAXIS. Soft and weathered soils are selected as a soil ground. The relation curves between horizontal displacement and actual passive force of the kicker block for each soil ground are obtained through numerical analyses. From the curves, the actual passive forces are determined as a yielding point, which are about 55.5% and 66% of Rankine's passive forces in soft and weathered soils, respectively.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.91-92
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• 2023

본 논문에서는 노후화된 화력발전소를 해체하고 원래의 자연환경으로 복원하는 공사가 진행되는 가운데 화력발전소 내 대형 철골구조물 중 하나인 터빈동을 발파해체공법을 적용하여 해체한 사례이다. 두께 30mm의 철골 부재를 절단하기 위해 금속제트가 발생되는 전용 장약용기를 제작하였으며, 철골 부재의 두께가 30mm 이상인 일부 철골 부재의 경우에는 가우징을 이용하여 사전취약화를 실시하였다. 또한 구조물 내부에 있는 일부 철골 부재에 대해 kicker charge를 사용하여 붕괴거동에 영향을 미치지 않도록 하였다. 발파에 사용한 전체 장약량은 175kg, 전자뇌관 165개, 장약용기 124개를 사용하여 계획된 방향으로 점진붕괴되었으며, 주변 시설물에 피해 없이 발파해체를 완료하였다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.523-526
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• 2002

In the bearing wall systems, a form work has a lot of room that saves cost because it takes a substantial proportion of construction cost. Therefore the systemic and efficient methods are required in the form work. This study focuses on methods that enhance the quality and the productivity of form work and presents the kicker form as an alternative plan to simplify the form work through being modular and automatical it. Work sampling method is used for productivity measurement. It is expected that it will reduce the work process and improve the Qualify and the podructivity of construction.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.299-305
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• 2018

Perception refers to the process of acquiring all the information about the environment through various sensory organs such as the visual, auditory, tactile, and olfactory senses and integrating and interpreting the information transmitted to the brain. The ability to use these perceptions efficiently is called perceptual skill, and perceptual skill is an important factor for improving performance in the field of sports. As a result, many researchers have developed various perceptual training programs to maximize these perceptual skills while they have also progressed on attempting to verify their effects. The perceptual skill training introduced in this study is a training method that focuses on visual perception and is a training method that is applied in the United States and Europe. to improve sports performance. As a result of carrying out the perceptual skills training based on the kicker's important clue (the kicker's hip - the angle of the body and foot before kicking) to the goalkeeper in the situation of a soccer penalty kick improved the ability of predicting the direction of the ball while even in tennis, carrying out the perceptual skills training based on the server's important clue (position, ball, racket) improved the accuracy of the ability to predict in the direction of serve. Recently, there have been numerous research studies that were carried out on such perceptual skills training, but the number of studies conducted are insufficient, especially in Korea where research studies on perceptual training seem to be in a relatively neglected state. In addition, extensive studies need to be carried out to investigate whether the improvement of perceptual skills in the laboratory situation can be transitioned to an actual performance situation. Therefore, in order to elevate sports performance, researchers need to examine the perceptual training program's extent of necessity as well as the research direction regarding its effects.

• Journal of dental hygiene science
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• v.18 no.6
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• pp.367-373
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• 2018

The consumption of beverages among children is rising. The purpose of this study was to examine the effect of kid's drink on dental resin-based pit and fissure sealant. Pororo, I-kicker, Sunkist kids were included in the experimental groups, and Samdasu was included in the control group. A conventional dental sealant material ($Clinpro^{TM}Sealant^{(R)}$) was selected for this study. Resin specimens (8 mm in diameter and 1 mm in thickness) were prepared according to manufacturers' instructions and the initial roughness (Ra) was then measured. The pH of all the four groups was measured using a pH meter. The specimens were individually immersed in 5 ml of the experimental solutions and stored at $37^{\circ}C$ for 72 hours. Following this, the surface roughness of the resin specimens was measured by Surftest. The concentration of residual monomer released was determined by high performance liquid chromatography (HPLC). The surface morphology of the resin specimen was evaluated before and after storage by scanning electron microscopy (SEM). Data were statistically analyzed using Kruskal-Wallis and Duncan's test. The results showed that all the children's beverages examined in this study contained citric acid. The pH of I-kicker was the lowest ($3.03{\pm}0.01$), followed by that of Sunkist kids ($3.26{\pm}0.02$) and Pororo ($3.47{\pm}0.02$). We observed an increase in the surface roughness of resin specimens after 72 h of immersion in all the beverages tested (p<0.05). There was matrix degradation after immersion, visualized on SEM image, in all the beverage groups. Bisphenol-A-glycidyl methacrylate was not detected after 72 hours, but triethylene glycol dimethacrylate levels were increased in all the beverages tested during the 72 hours by HPLC. These results suggest that intake of beverages containing acid can cause degradation of the resin-based pit and fissure sealants in children.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1197-1199
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• 2015

PLS-II 키커 모듈레이터는 마그넷 코일 4개에 펄스전원을 공급하고 있다. 에너지 저장용 커패시턴스 합성 값은 $3.2{\mu}F$이고, 두 개의 회로로 커패시턴스 $1.6{\mu}F$로 나뉘어져 있다. 키커 마그넷 코일 두 개를 직렬연결하고 두 개 회로를 병렬구조로 하여 펄스 폭 $6.8{\mu}s$, 전류 20 kA, 운전주파수 10 Hz로 운전되고 있다. 커패시터와 코일의 직렬공진에 의해 에너지를 전달하는 직렬공진회로이다. 인덕턴스를 줄일 목적으로 전원장치는 키커 마그넷 가까이에 설치되어있다. 이것은 펄스폭에 영향을 미치게 되며 운전전류에 민감해서 그 값이 커지게 되면 입력공급 전압이 높아지게 된다. 장치의 운영적인 측면에서 고장이나 키커 모듈레이터 내부에 문제가 발생 하였을 경우 저장링 터널에 설치되어있는 전원을 점검하기 위해서는 빔 운전을 중단하고 접근을 해야 하는 불편함이 있다. 키커 모듈레이터 전원을 단일전원을 하고자 하는 궁극적인 목적은 입사효율을 높이기 위함이며, 입사되는 키커의 변수를 조정하고자 한다. 또한, 정비의 용이성과 입사 시 키커의 전압, 전류를 개별적으로 조정이 가능하게 단일전원으로 장치를 제작하고자 한다. 본 논문에서는 단일전원의 설계와 실험내용을 소개하고자 한다.