• 제목/요약/키워드: Repetition

검색결과 1,570건 처리시간 0.024초

피코초 레이저 및 CDE를 이용한 TSV가공기술 (TSV Formation using Pico-second Laser and CDE)

  • 신동식;서정;조용권;이내응
    • 한국레이저가공학회지
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    • 제14권4호
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    • pp.14-20
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    • 2011
  • The advantage of using lasers for through silicon via (TSV) drilling is that they allow higher flexibility during manufacturing because vacuums, lithography, and masks are not required; furthermore, the lasers can be applied to metal and dielectric layers other than silicon. However, conventional nanosecond lasers have disadvantages including that they can cause heat affection around the target area. In contrast, the use of a picosecond laser enables the precise generation of TSVs with a smaller heat affected zone. In this study, a comparison of the thermal and crystallographic defect around laser-drilled holes when using a picosecond laser beam with varing a fluence and repetition rate was conducted. Notably, the higher fluence and repetition rate picosecond laser process increased the experimentally recast layer, surface debris, and dislocation around the hole better than the high fluence and repetition rate. These findings suggest that even the picosecond laser has a heat accumulation effect under high fluence and short pulse interval conditions. To eliminate these defects under the high speed process, the CDE (chemical downstream etching) process was employed and it can prove the possibility to applicate to the TSV industry.

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Starting Current Application for Magnetic Stimulation

  • Choi, Sun-Seob;Bo, Gak-Hwang;Kim, Whi-Young
    • Journal of Magnetics
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    • 제16권1호
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    • pp.51-57
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    • 2011
  • A power supply for magnetic-stimulation devices was designed via a control algorithm that involved a start current application based on a resonant converter. In this study, a new power supply for magnetic-stimulation devices was designed by controlling the pulse repetition frequency and pulse width. The power density could be controlled using the start-current-compensation and ZCS (zero-current switching) resonant converter. The results revealed a high-repetition-frequency, high-power magnetic-stimulation device. It was found that the stimulation coil current pulse width and that pulse repetition frequency could be controlled within the range of 200-450 ${\mu}S$ and 200-900 pps, respectively. The magnetic-stimulation device in this study consisted of a stimulation coil device and a power supply system. The maximum power of the stimulation coil from one discharge was 130 W, which was increased to 260 W using an additional reciprocating discharge. The output voltage was kept stable in a sinusoidal waveform regardless of the load fluctuations by forming voltage and current control using a deadbeat controller without increasing the current rating at the starting time. This paper describes this magnetic-stimulation device to which the start current was applied.

Minimum Bandwidth Regenerating Codes Based on Cyclic VFR Codes

  • Wang, Jing;Wang, Shuxia;Wang, Tiantian;Zhang, Xuefei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권7호
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    • pp.3583-3598
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    • 2019
  • In order to improve the reliability and repair efficiency of distributed storage systems, minimum bandwidth regenerating (MBR) codes based on cyclic variable fractional repetition (VFR) codes are constructed in this thesis, which can repair failed nodes accurately. Specifically, in order to consider the imbalance of data accessed by the users, cyclic VFR codes are constructed according to that data with different heat degrees are copied in different repetition degrees. Moreover, we divide the storage nodes into groups, and construct MBR codes based on cyclic VFR codes to improve the file download speed. Performance analysis and simulation results show that, the repair locality of a single node failure is always 2 when MBR codes based on cyclic VFR codes are adopted in distributed storage systems, which is obviously superior to the traditional MBR codes. Compared with RS codes and simple regenerating codes, the proposed MBR codes based on cyclic VFR codes have lower repair locality, repair complexity and bandwidth overhead, as well as higher repair efficiency. Moreover, relative to FR codes, the MBR codes based on cyclic VFR codes can be applicable to more storage systems.

Adaptive-and-Resolvable Fractional Repetition Codes Based on Hypergraph

  • Tiantian Wang;Jing Wang;Haipeng Wang;Jie Meng;Chunlei Yu;Shuxia Wang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권4호
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    • pp.1182-1199
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    • 2023
  • Fractional repetition (FR) codes can achieve exact uncoded repair for multiple failed nodes, with lower computational complexity and bandwidth overhead, and effectively improve repair performance in distributed storage systems (DSS). The actual distributed storage system is dynamic, that is, the parameters such as node storage overhead and number of storage nodes will change randomly and dynamically. Considering that traditional FR codes cannot be flexibly applied to dynamic distributed storage systems, a new construction scheme of adaptive-and-resolvable FR codes based on hypergraph coloring is proposed in this paper. Specifically, the linear uniform regular hypergraph can be constructed based on the heuristic algorithm of hypergraph coloring proposed in this paper. Then edges and vertices in hypergraph correspond to nodes and coded packets of FR codes respectively, further, FR codes is constructed. According to hypergraph coloring, the FR codes can achieve rapid repair for multiple failed nodes. Further, FR codes based on hypergraph coloring can be generalized to heterogeneous distributed storage systems. Compared with Reed-Solomon (RS) codes, simple regenerating codes (SRC) and locally repairable codes (LRC), adaptive-and-resolvable FR codes have significant advantages over repair locality, repair bandwidth overhead, computational complexity and time overhead during repairing failed nodes.

Traumatic Repetition and Writing as Awakening in Iris Murdoch's The Black Prince

  • Kim, Il-Yeong;Ryu, In Sang
    • 영어영문학
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    • 제57권3호
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    • pp.495-513
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    • 2011
  • Murdoch's novel, The Black Prince, is not, as most critics have suggested, an autobiographical novel. It is about the inner life or rather trauma of Bradley Pearson, an artist who repeatedly dreams about a shabby paper shop which used to be run by his "unsuccessful" parents. In this respect, Freudian concept of trauma is helpful since it can explain Bradley's present repetition of his past traumatic experience, while allowing us to understand the nature of his trauma which reveals itself not only through his repeated nightmares but also through the women who are represented as diverse versions of his mother, the origin of Bradley's trauma. Caruth's concept of traumatic awakening and traumatic survival is also instrumental in understanding the nature of the traumatic experience which Bradley undergoes in this novel. Induced by Loxias's address, Bradley makes a confession of "the sins," which makes possible his traumatic survival as well as traumatic awakening, which is transmitted not only to Loxias but also to us the readers. In this sense, the significance of Bradley's awakening is not confined to his past only, but becomes a matter of a social dimension. The meaning of Bradley's writing lies in this fact.

주의하지 않은 방해자극이 표적의 식별에 미치는 영향 (The Influence of Unattended Distractors on the Identification of Targets)

  • 박창호
    • 인지과학
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    • 제24권4호
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    • pp.365-391
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    • 2013
  • 순간 노출된 자극판에서 표적과 동일한 방해자극이 옆에 있을 때, 표적의 정확 보고율이 떨어지는 부적 반복효과가 보고되어 왔다. 본 연구는 부적 반복효과의 성질을 탐구하기 위해, 자극판의 제시 전에 표적이 제시될 가능성이 있는 위치를 빨간 네모(주의창)로 표시하고, 표적이 제시되지 않는 위치는 회색 네모(비주의창)로 표시하는 기법을 도입했다. 실험참가자는 주의창 위치를 주의함으로써 표적을 더 잘 식별할 수 있을 것이다. 실험 1에서는 세 위치 중 두 위치가 개별(작은) 주의창으로 표시되었고, 실험 2에서는 네 위치 중 가운데 두 위치가 합쳐진(큰) 주의창으로 표시되었으며, 실험 3에서는 네 위치 중 가운데 두 위치가 큰 주의창으로 표시되거나 그 둘 중 한 위치가 작은 주의창으로 표시되었다. 세 실험의 결과, 주의창 위치에 제시된 두 문자들을 식별하는 조건에서는 선행 연구와 같이 부적 반복효과가 관찰되었다. 비주의창 위치에 제시됨으로써 주의 받지 않은 방해자극은, 세 실험에 걸쳐서 표적의 식별에 부적 반복효과(혹은 그 경향성)를 낳거나, 또 그 반대효과인 정적 반복효과(혹은 그 경향성)를 낳았는데, 표적과 방해자극의 거리 및 주의창의 크기가 중요한 변인인 것으로 보인다. 이러한 결과는 부적 반복효과에 대한 반복맹 설명이나 위치불확실성 가설이나 억제적 주의포착 가설로 잘 설명되지 않는다. 대신에 자극판에서 요구되는 공간 주의 변동을 고려할 필요성을 제안한다. 주의와 지각의 관계에서 본 연구 과제의 역할에 대한 논의를 하였다.

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저항운동의 운동 강도별 세트 간 휴식시간 차이가 근수축력, 반복횟수 및 총운동량에 미치는 영향 (Effects of Varied Resistance Training Intensities and Rest Intervals Between Sets on iEMG, Repetition Rate, and Total Work)

  • 송상협;이용수;한아름;김시영;고성식
    • 한국체육학회지인문사회과학편
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    • 제51권5호
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    • pp.639-647
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    • 2012
  • 본 연구는 최근 3개월 동안 저항운동 경력이 없는 남학생 14명을 선정하여 2주간 체력을 안정화 시킨 후, 운동 강도(90, 75, 60% 1RM)와 세트 간 휴식시간(1, 3, 5분)을 조합한 9가지 운동 프로그램을 1주일 간격으로 적용하였다. 근기능 지표들(근수축력, 반복횟수, 총운동량)의 변화를 분석함으로써 적절한 운동 강도와 휴식시간의 효용성을 분석한 결과는 다음과 같다. 운동 강도별 세트 간 휴식시간에 따른 대흉근의 근수축력은 90, 60% 1RM 강도에서 유의하게 감소하였으나, 60% 1RM 강도에서 세트 간 5분 휴식 시에는 유의하게 증가하는 것으로 나타났고, 상완삼두근의 근수축력은 90% 1RM에서 세트 간 휴식시간에 따라 유의하게 감소하는 것으로 나타났다. 반복횟수와 총운동량은 세트 간 휴식시간에 따라 모든 강도에서 유의하게 감소하였으나, 강도가 낮아지고 휴식시간이 길어질수록 유의하게 증가하는 것으로 나타났다. 이상의 결과를 종합하면, 처음 저항운동을 시작하는 사람이나 비단련자의 경우에는 근기능 향상 및 정확한 자세와 기술을 습득할 수 있도록 운동 강도를 낮추거나 휴식시간을 길게 유지하는 방법이 효과적일 것이다.

고체절연체의 내부결함에 따른 부분방전 특성과 패턴분류 (Properties of PD and Classification of Defect Patterns in Solid Insulation)

  • 강성화;박영국;이광우;김완수;이용희;임기조
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1624-1626
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    • 1999
  • PD in defect of solid insulation system is very harmful since It often leads to deterioration of insulation by the combined action of the discharge ions bombarding the surface and the action of chemical compounds that are formed by the discharge. PD can indicate incipient failure, so it has been used to determine degradation of insulation. In this paper. we investigated PD in defects of solid insulation by using statical method and classified PD patterns with surface discharge, electrical tree and void discharge by using Kohonen network. we used peak charge, average discharge power, average discharge current, repetition rate, skewness, kurtosis, QN of the max pulse height vs. repetition rate $H_q(n)$ for analysis and classification.

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현대 패션에 나타난 중첩 기법의 유형과 사례분석 (Types of Overlapping Technique in Contemporary Fashion)

  • 임지아;김민자
    • 복식
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    • 제63권8호
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    • pp.106-124
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    • 2013
  • Compared to traditional fashion design, modern fashion design is used as a means that creates original and multiple types of beauty beyond fixed and standardized concept and form. Overlapping technique is the most suitable means to shed classical, authoritative and conservative form and it enables diverse borrowing and quotation for creation. This study aimed to analyze overlapping techniques that are expressed in art, architecture and fashion to find out its characteristics in the field of fashion. The result of this study is as follows. Based on theories of visual perception and advance research, types of overlapping technique were classified as pile, repetition, penetration and transparency. When comparing overlapping techniques in modern fashion with those of painting and architecture, fashion was distinctive in that it had movement and communicativeness through overlapping of fashion and the human body. Therefore, the overlapping technique has wide application and adaptation and can cause specialty, movability, communicativeness and collectivity, which can arouse psychological inspiration.