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A Study on the Application of an Integrated Management Software for a Petrochemical Plant Project (화공플랜트 프로젝트에서 통합관리 소프트웨어 적용에 관한 연구)

  • Kim, Yoon;Lee, Dong-Eon;Yoo, Ho-seon
    • Plant Journal
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    • v.6 no.2
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    • pp.56-61
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    • 2010
  • In this paper, an integrated management software is developed to promote the business competitive power. The interoperability among the software accounts for an ever growing performance of petrochemical plant project. If the interoperability is built up, company has taken advantages of quality, schedule, cost, and safety by active communication. The advantage of an integrated management software is examined in three aspects. In efficiency aspect, It takes advantage of the saving about the various information and the standard of project performance procedure. In quality, the integration gave aid to a quality improvement through team collaboration and data management within project life cycle. In cost, poor communications between systems waste 30% of project costs. If information could be inputted once and used by all, reductions in delivery time up to 40% were possible. Therefore, 10% savings of engineering cost was also possible.

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Low Power SoC Design Trends Using EDA Tools (설계툴을 사용한 저전력 SoC 설계 동향)

  • Park, Nam Jin;Joo, Yu Sang;Na, Jung-Chan
    • Electronics and Telecommunications Trends
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    • v.35 no.2
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    • pp.69-78
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    • 2020
  • Small portable devices such as mobile phones and laptops currently display a trend of high power consumption owing to their characteristics of high speed and multifunctionality. Low-power SoC design is one of the important factors that must be considered to increase portable time at limited battery capacities. Popular low power SoC design techniques include clock gating, multi-threshold voltage, power gating, and multi-voltage design. With a decreasing semiconductor process technology size, leakage power can surpass dynamic power in total power consumption; therefore, appropriate low-power SoC design techniques must be combined to reduce power consumption to meet the power specifications. This study examines several low-power SoC design trends that reduce semiconductor SoC dynamic and static power using EDA tools. Low-power SoC design technology can be a competitive advantage, especially in the IoT and AI edge environments, where power usage is typically limited.

Anti-windup Integral-Proportional Controller for Variable-Speed Motor Drives

  • Park, Jong-Gyu;Chung, Jae-ho;Shin, Hwi-Beom
    • Journal of Power Electronics
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    • v.2 no.2
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    • pp.130-138
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    • 2002
  • The windup phenomenon appears and degrades control performance when a controller with integrating action is used and plant input is limited. An anti-windup integal-proportional(IP) controller is proposed for the variable-speed moter drives and it is experimentally applied to the speed control of a vector-controlled induction moter driven by a pulse width modulated (PWM) voltage source inverter (VSI). The consistency range of the IP controller is firstly derived and the intergal state is controlled to salisfy always the consistency range according to whether the the controller output is saturated or not. Although the operating condition like moter load or speed command is changed under the limited plant input, It is expermentally verified that the speed response has much improved performance, such as no overshoot and fast settling time, and the maximmum plant input is also effectively utilized.

A Strategy for Integrated Target Recognition and High Quality Compression (목표물 탐지를 고려한 통합 이미지 압축에 관한 연구)

  • 남진우
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2000.08a
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    • pp.257-260
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    • 2000
  • In modern battlefield situation, radar and infrared sensors may be located on aircraft having limited computational resources available for real-time computer processing. Hence sensor images are transmitted typically to central stations for processing and automatic target recognition/detection. Owing to the limited bandwidth channels that are typically available between the aircraft and processing stations, images are compressed prior to transmission to facilitate rapid transfer. In this paper we examine the problem of compressing sensor data for transmission, given that target recognition is the end goal. Performance result shows that the front-end target recognition system achieves a relatively high level of performance as well as a high compression ratio.

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Improved Understanding of LeTID of Single-crystalline Silicon Solar Cell with PERC

  • Kim, Kwanghun;Baik, Sungsun;Park, Jaechang;Nam, Wooseok;Jung, Jae Hak
    • Current Photovoltaic Research
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    • v.6 no.4
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    • pp.94-101
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    • 2018
  • Light elevated temperature induced degradation (LeTID) was noted as an issue in multi-crystalline silicon solar cells (MSSC) by Ram speck in 2012. In contrast to light induced degradation (LID), which has been researched in silicon solar cells for a long time, research about both LeTID and the mechanism of LeTID has been limited. In addition, research about LeTID in single-crystalline silicon solar cells (SSSC) is even more limited. In order to improve understanding of LeTID in SSSC with a passivated emitter rear contact (PERC) structure, we fabricated four group samples with boron and oxygen factors and evaluated the solar cell characteristics, such as the cell efficiency, $V_{oc}$, $I_{sc}$, fill factor (FF), LID, and LeTID. The trends of LID of the four group samples were similar to the trend of LeTID as a function of boron and oxygen.

A Hierarchical Binary-search Tree for the High-Capacity and Asymmetric Performance of NVM (비대칭적 성능의 고용량 비휘발성 메모리를 위한 계층적 구조의 이진 탐색 트리)

  • Jeong, Minseong;Lee, Mijeong;Lee, Eunji
    • IEMEK Journal of Embedded Systems and Applications
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    • v.14 no.2
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    • pp.79-86
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    • 2019
  • For decades, in-memory data structures have been designed for DRAM-based main memory that provides symmetric read/write performances and has no limited write endurance. However, such data structures provide sub-optimal performance for NVM as it has different characteristics to DRAM. With this motivation, we rethink a conventional red-black tree in terms of its efficacy under NVM settings. The original red-black tree constantly rebalances sub-trees so as to export fast access time over dataset, but it inevitably increases the write traffic, adversely affecting the performance for NVM with a long write latency and limited endurance. To resolve this problem, we present a variant of the red-black tree called a hierarchical balanced binary search tree. The proposed structure maintains multiple keys in a single node so as to amortize the rebalancing cost. The performance study reveals that the proposed hierarchical binary search tree effectively reduces the write traffic by effectively reaping the high capacity of NVM.

How Do Bacteria Maximize Their Cellular Assets?

  • Kim, Juhyun
    • Microbiology and Biotechnology Letters
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    • v.49 no.4
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    • pp.478-484
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    • 2021
  • Cellular resources including transcriptional and translational machineries in bacteria are limited, yet microorganisms depend upon them to maximize cellular fitness. Bacteria have evolved strategies for using resources economically. Regulatory networks for the gene expression system enable the cell to synthesize proteins only when necessary. At the same time, regulatory interactions enable the cell to limit losses when the system cannot make a cellular profit due to fake substrates. Also, the architecture of the gene expression flow can be advantageous for clustering functionally related products, thus resulting in effective interactions among molecules. In addition, cellular systems modulate the investment of proteomes, depending upon nutrient qualities, and fast-growing cells spend more resources on the synthesis of ribosomes, whereas nonribosomal proteins are synthesized in nutrient-limited conditions. A deeper understanding of cellular mechanisms underlying the optimal allocation of cellular resources can be used for biotechnological purposes, such as designing complex genetic circuits and constructing microbial cell factories.

A Study on The Create and Control of Sound using The Quantum Superposition Characteristics (양자의 중첩 특성을 이용한 소리의 생성 및 제어에 대한 연구)

  • Min-Ho Cho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.4
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    • pp.687-692
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    • 2023
  • This research began with the intention to create music using the superposition characteristics of quantum computers. Existing music has characteristics that are limited to those composed by composers. However, music using the overlap of quantum computers has musical characteristics that change when executed within a limited range. Using this, you will be able to create music that changes based on specific chords at run time. In this paper, quantum computers and existing computers are connected to generate sound, And it focuses on creating changing sounds by applying the nature of superposition.

Reliability-based Structural Design Optimization Considering Probability Model Uncertainties - Part 1: Design Method (확률모델 불확실성을 고려한 구조물의 신뢰도 기반 최적설계 - 제1편: 설계 방법)

  • Ok, Seung-Yong;Park, Wonsuk
    • Journal of the Korean Society of Safety
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    • v.27 no.5
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    • pp.148-157
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    • 2012
  • Reliability-based design optimization (RBDO) problem is usually formulated as an optimization problem to minimize an objective function subjected to probabilistic constraint functions which may include deterministic design variables as well as random variables. The challenging task is that, because the probability models of the random variables are often assumed based on limited data, there exists a possibility of selecting inappropriate distribution models and/or model parameters for the random variables, which can often lead to disastrous consequences. In order to select the most appropriate distribution model from the limited observation data as well as model parameters, this study takes into account a set of possible candidate models for the random variables. The suitability of each model is then investigated by employing performance and risk functions. In this regard, this study enables structural design optimization and fitness assessment of the distribution models of the random variables at the same time. As the first paper of a two-part series, this paper describes a new design method considering probability model uncertainties. The robust performance of the proposed method is presented in Part 2. To demonstrate the effectiveness of the proposed method, an example of ten-bar truss structure is considered. The numerical results show that the proposed method can provide the optimal design variables while guaranteeing the most desirable distribution models for the random variables even in case the limited data are only available.

Resource Allocation in Full-Duplex OFDMA Networks: Approaches for Full and Limited CSIs

  • Nam, Changwon;Joo, Changhee;Yoon, Sung-Guk;Bahk, Saewoong
    • Journal of Communications and Networks
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    • v.18 no.6
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    • pp.913-925
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    • 2016
  • In-band wireless full-duplex is a promising technology that enables a wireless node to transmit and receive at the same time on the same frequency band. Due to the complexity of self-interference cancellation techniques, only base stations (BSs) are expected to be full-duplex capable while user terminals remain as legacy half-duplex nodes in the near future. In this case, two different nodes share a single subchannel, one for uplink and the other for downlink, which causes inter-node interference between them. In this paper, we investigate the joint problem of subchannel assignment and power allocation in a single-cell full-duplex orthogonal frequency division multiple access (OFDMA) network considering the inter-node interference. Specifically, we consider two different scenarios: i) The BS knows full channel state information (CSI), and ii) the BS obtains limited CSI through channel feedbacks from nodes. In the full CSI scenario, we design sequential resource allocation algorithms which assign subchannels first to uplink nodes and then to downlink nodes or vice versa. In the limited CSI scenario, we identify the overhead for channel measurement and feedback in full-duplex networks. Then we propose a novel resource allocation scheme where downlink nodes estimate inter-node interference with low complexity. Through simulation, we evaluate our approaches for full and limited CSIs under various scenarios and identify full-duplex gains in various practical scenarios.