• 제목/요약/키워드: performance limitation

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하드 디스크 드라이브 엑추에이터의 동적성능향상을 위한 VCM 설계 (VCM Design to Improve Dynamic Performance of Actuator in a Disk Drive)

  • 이행수;강성우;김영훈;황태연
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.911-914
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    • 2003
  • As high-capacity disk drives pow in track density, the allowable level of PES is becoming smaller. In this paper, some design concept of actuator is introduced to suppress the Butterfly mode that imposes the fundamental limitation on servo bandwidth. The effect of dynamics of proposed actuator on PES is examined by simulation.

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WRR 알고리즘 지원 시스톨릭 구조 가상 출력 큐 (Systolic Architecture Vitrual Output Queue with Weighted Round Robin Algorithm)

  • 조용권;이문기;이정희;이범철
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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    • pp.347-350
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    • 2002
  • In the input buffer switch system, VOQ(Virtual Output Queue) archives 100% throughput. The VOQ with the systolic architecture maintains an uniform performance regardless of a number of Packet class and output port, so that it doesn't have a limitation of scalability. In spite of these advantages, the systolic architecture VOQ is difficult to change sorting order In this paper, we Proposed a systolic architecture VOQ which support weighted round robin(WRR) algorithm to provide with flow control service.

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The Optimal Tuning Algorithm for Fuzzy Controller

  • Oh, Sung-kwun;Park, Jong-jin;Woo, Kwang-bang
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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    • pp.830-833
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    • 1993
  • In this paper, an optimal tuning Algorithms is presented to automatically improve the performance of fuzzy controller, using the simplified reasoning method and the proposed complex method. The method estimates automatically the optimal values of the parameters of fuzzy controller, according to the change rate and limitation condition of output. The controller is applied to plants with dead time. Then, computer simulations are conducted at step input and the performances are evaluated in the ITAE.

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VLIW (Very Long Instruction Word) 형식 드론 FCC(Flight Control Computer)의 실시간성 개선을 위한 소프트웨어 성능 가속화 연구 (A Study on software performance acceleration for improving real time constraint of a VLIW type Drone FCC)

  • 조두산
    • 한국산업융합학회 논문집
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    • 제20권1호
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    • pp.1-7
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    • 2017
  • Most conventional processors execute program instructions in a sequential manner. On the other hand, VLIW processor can execute multiple instructions at the same time. It exploits instruction level parallelism to improve system performance. To that end, program code should be rearranged to VLIW instruction format by a compiler. The compiler determine an optimal execution order of instructions of a program code. This instruction ordering is also called instruction scheduling. The scheduling is an algorithm that decides the execution order for instruction codes in loop parts of a program so that the instruction level parallelism can be maximized. In this research, we apply an existing scheduling algorithm to a VLIW FCC and describe analysis results to further improve its performance. And, we present a solution to solve some limitation of the existing scheduling technique. By using our solution, FCC's performance can be improved upto 32% compared to the existing scheduling only setting.

New Control System Aspects for Supporting Complex Data and High Performance System

  • Yoo, Dae-Seung;Tan, Vu Van;Yi, Myeong-Jae
    • Journal of Computing Science and Engineering
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    • 제2권4호
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    • pp.394-411
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    • 2008
  • The data in automation and control systems can be achieved not only from different field devices but also from different OPC (OLE for Process Control) servers. However, current OPC clients can only read and decode the simple data from OPC servers. They will have some problems to acquire structured data and exchange the structured data. In addition to the large network control systems, the OPC clients can read, write, and subscribe to thousands of data points from/to OPC servers. Due to that, the most important factor for building a high performance and scalable industrial control system is the ability to transfer the process data between server and client in the most efficient and fastest way. In order to solve these problems, we propose a means to implement the OPC DA (Data Access) server supporting the OPC complex data, so that the OPC DA clients are able to read and decode any type of data from OPC servers. We also propose a method for caching the process data in large industrial control systems to overcome the limitation of performance of the pure OPC DA system. The performance analysis and discussion indicate that the proposed system has an acceptable performance and is feasible in order for applying to real-time industrial systems today.

EUV pellicle의 standoff 거리에 따른 이미지 전사 특성 평가 (Evaluation on the Relationship between Mask Imaging Performance and Standoff Distance of EUV Pellicle)

  • 우동곤;홍성철;김정식;조한구;안진호
    • 반도체디스플레이기술학회지
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    • 제15권1호
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    • pp.22-26
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    • 2016
  • Extreme ultraviolet (EUV) pellicle is one of the most concerned research in the field of EUV lithography (EUVL). Imaging performance of EUV mask with pellicle should be investigated prior to high volume manufacturing (HVM) of EUVL. In this paper, we analyzed the relationship between standoff distance and imaging performance of EUV mask to verify the influences of relative standoff distance on imaging performance. As a result, standoff distance of EUV pellicle has no effect on imaging performance of EUV mask such as critical dimension (CD), normalized image log slope (NILS) and image contrast. Therefore, pellicle support structure can be flexibly designed and modified in diverse ways to complement the thermal limitation of EUV pellicle membrane.

High performance γ-ray imager using dual anti-mask method for the investigation of high-energy nuclear materials

  • Lee, Taewoong;Lee, Wonho
    • Nuclear Engineering and Technology
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    • 제53권7호
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    • pp.2371-2376
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    • 2021
  • As the γ-ray energy increases, a reconstructed image becomes noisy and blurred due to the penetration of the γ-ray through the coded mask. Therefore, the thickness of the coded mask was increased for high energy regions, resulting in severely decreased the performance of the detection efficiency due to self-collimation by the mask. In order to overcome the limitation, a modified uniformly redundant array γ-ray imaging system using dual anti-mask method was developed, and its performance was compared and evaluated in high-energy radiation region. In the dual anti-mask method, the two shadow images, including the subtraction of background events, can simultaneously contribute to the reconstructed image. Moreover, the reconstructed images using each shadow image were integrated using a hybrid update maximum likelihood expectation maximization (h-MLEM). Using the quantitative evaluation method, the performance of the dual anti-mask method was compared with the previously developed collimation methods. As the shadow image which was subtracted the background events leads to a higher-quality reconstructed image, the reconstructed image of the dual anti-mask method showed high performance among the three collimation methods. Finally, the quantitative evaluation method proves that the performance of the dual anti-mask method was better than that of the previously reconstruction methods.

Ethical Values Reflected on Zakat and CSR: Indonesian Sharia Banking Financial Performance

  • AULIYAH, Robiatul;BASUKI, Basuki
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.225-235
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    • 2021
  • The objective of this study is to identify the effects of ethical values reflected on zakat and Corporate Social Responsibility (CSR) on the financial performance of sharia banking in Indonesia. This study contributes to the Indonesia Financial Service Authority (Otoritas Jasa Keuangan (OJK) policies concerning the need for implementing ethical values in sharia banking and other sharia financial entities based on the philanthropic model, this study posits that firms undertaking zakat and charity are ethical firms. The population of this study is 8 sharia banks listed on the Indonesia Stock Exchange (IDX) in 2014-2018. The result of the study showed that zakat disclosure significantly affected financial performance. Moreover, ethical values that were proxied by CSR disclosure did not significantly affect financial performance. The limitation of the study is the limited number of the sample; therefore, it is expected that the future research adds other sharia financial entities and adds the dimension of management, sustainability, product, and the environment as benchmarks of ethical values. The originality of this study offers an additional explanation of the relationship between ethical values and performance by investigating zakat and CSR disclosure which is a unique factor in Indonesia.

The Impact of Competition on the Profitability and Risk-Taking of Commercial Banks in India

  • RASTOGI, Shailesh;KANOUJIYA, Jagjeevan;BHIMAVARAPU, Venkata Mrudula;GAUTAM, Rahul Singh
    • The Journal of Asian Finance, Economics and Business
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    • 제9권5호
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    • pp.377-388
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    • 2022
  • The purpose of this article is to investigate the impact of competition on the performance of Indian banks. The survey includes banks from both the public and private sectors. The study will collect data for four years, from 2015 to 2019. Dynamic and static panel data are applied to estimate the association between competition and the bank's performance. Profitability and risk-taking are the performance measures used in the study. The study's main findings are that competition does not impact the banks' profitability in India. However, the findings concerning risk-taking are mixed. Therefore, it can be inferred that overall competition does not impact the banks' performance in India. Other measures of performance of the banks could have been used in the study. It is a limitation to use data of four years. Data for a much more extended period could have also been used. This is one of the few papers on the subject. Therefore, its contribution is very significant. The gap in studies on the topic of competition versus performance of the banks is veritably filled by the current study's findings.

Design Methodology for Optimal Phase-Shift Modulation of Non-Inverting Buck-Boost Converters

  • Shi, Bingqing;Zhao, Zhengming;Li, Kai;Feng, Gaohui;Ji, Shiqi;Zhou, Jiayue
    • Journal of Power Electronics
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    • 제19권5호
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    • pp.1108-1121
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    • 2019
  • The non-inverting buck-boost converter (NIBB) is a step-up and step-down DC-DC converter suitable for wide-input-voltage-range applications. However, when the input voltage is close to the output voltage, the NIBB needs to operate in the buck-boost mode, causing a significant efficiency reduction since all four switches operates in the PWM mode. Considering both the current stress limitation and the efficiency optimization, a novel design methodology for the optimal phase-shift modulation of a NIBB in the buck-boost mode is proposed in this paper. Since the four switches in the NIBB form two bridges, the shifted phase between the two bridges can serve as an extra degree of freedom for performance optimization. With general phase-shift modulation, the analytic current expressions for every duty ratio, shifted phase and input voltage are derived. Then with the two key factors in the NIBB, the converter efficiency and the switch current stress, taken into account, an objective function with constraints is derived. By optimizing the derived objective function over the full input voltage range, an offline design methodology for the optimal modulation scheme is proposed for efficiency optimization on the premise of current stress limitation. Finally, the designed optimal modulation scheme is implemented on a DSPs and the design methodology is verified with experimental results on a 300V-1.5kW NIBB prototype.