• Title/Summary/Keyword: Fault Study

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MLC NAND-type Flash Memory Built-In Self Test for research (MLC NAND-형 Flash Memory 내장 자체 테스트에 대한 연구)

  • Kim, Jin-Wan;Kim, Tae-Hwan;Chang, Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.3
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    • pp.61-71
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    • 2014
  • As the occupancy rate of the flash memory increases in the storage media market for the embedded system and the semi-conductor industry grows, the demand and supply of flash memory is increasing by a big margin. They are especially used in large quantity in the smart phones, tablets, PC, SSD and Soc(System on Chip) etc. The flash memory is divided into the NOR type and NAND type according to the cell arrangement structure and the NAND type is divided into the SLC(Single Level Cell) and MLC(Multi Level Cell) according to the number of bits that can be stored in each cell. Many tests have been performed on NOR type such as BIST(Bulit-In Self Test) and BIRA(Bulit-In Redundancy Analysis) etc, but there is little study on the NAND type. For the case of the existing BIST, the test can be proceeded using external equipments like ATE of high price. However, this paper is an attempt for the improvement of credibility and harvest rate of the system by proposing the BIST for the MLC NAND type flash memory of Finite State Machine structure on which the pattern test can be performed without external equipment since the necessary patterns are embedded in the interior and which uses the MLC NAND March(x) algorithm and pattern which had been proposed for the MLC NAND type flash memory.

Implementation of Secure System for Blockchain-based Smart Meter Aggregation (블록체인 기반 스마트 미터 집계 보안 시스템 구축)

  • Kim, Yong-Gil;Moon, Kyung-Il
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.2
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    • pp.1-11
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    • 2020
  • As an important basic building block of the smart grid environment, smart meter provides real-time electricity consumption information to the utility. However, ensuring information security and privacy in the smart meter data aggregation process is a non-trivial task. Even though the secure data aggregation for the smart meter has been a lot of attention from both academic and industry researchers in recent years, most of these studies are not secure against internal attackers or cannot provide data integrity. Besides, their computation costs are not satisfactory because the bilinear pairing operation or the hash-to-point operation is performed at the smart meter system. Recently, blockchains or distributed ledgers are an emerging technology that has drawn considerable interest from energy supply firms, startups, technology developers, financial institutions, national governments and the academic community. In particular, blockchains are identified as having the potential to bring significant benefits and innovation for the electricity consumption network. This study suggests a distributed, privacy-preserving, and simple secure smart meter data aggregation system, backed up by Blockchain technology. Smart meter data are aggregated and verified by a hierarchical Merkle tree, in which the consensus protocol is supported by the practical Byzantine fault tolerance algorithm.

Model-based Diagnosis for Crack in a Gear of Wind Turbine Gearbox (풍력터빈 기어박스 내의 기어균열에 대한 모델 기반 고장진단)

  • Leem, Sang Hyuck;Park, Sung Hoon;Choi, Joo Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.6
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    • pp.447-454
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    • 2013
  • A model-based method is proposed to diagnose the gear crack in the gearbox under variable loading condition with the objective to apply it to the wind turbine CMS(Condition Monitoring System). A simple test bed is installed to illustrate the approach, which consists of motors and a pair of spur gears. A crack is imbedded at the tooth root of a gear. Tachometer-based order analysis, being independent on the shaft speed, is employed as a signal processing technique to identify the crack through the impulsive change and the kurtosis. Lumped parameter dynamic model is used to simulate the operation of the test bed. In the model, the parameter related with the crack is inversely estimated by minimizing the difference between the simulated and measured features. In order to illustrate the validation of the method, a simulated signal with a specified parameter is virtually generated from the model, assuming it as the measured signal. Then the parameter is inversely estimated based on the proposed method. The result agrees with the previously specified parameter value, which verifies that the algorithm works successfully. Application to the real crack in the test bed will be addressed in the next study.

An Overview and Implication of Apology Law and Disclosure Law in U.S.A. (미국의 사과법 및 디스클로져법의 의의와 그 시사점)

  • Lee, Won;Park, Ji Yong;Jang, Seung-Gyeong
    • The Korean Society of Law and Medicine
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    • v.19 no.1
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    • pp.81-111
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    • 2018
  • Recently in Korea, public interest about patient safety has increased because patient safety incidents occurred continuously. In addition, as the way of coping with medical personnel and medical institutions after occurrence of patient safety incident became controversial, the necessity of introducing apology law and disclosure law was raised. We analyzed the contents of apology law and disclosure law in U.S.A and critically examined the legislative movements in Korea. First, the Apology law requires that a medical personnel provide apology, consolation, sympathy to the patient for discomfort, pain, damage or death, and that the expression of apology shall be inadmissible as evidence of an admission of liability in civil action or administrative proceeding. The Apology law is divided into 'full apology law' and 'partial apology law' depending on whether mistake, error, fault, liability, and legal liability shall be inadmissible. Meanwhile, Disclosure law enforces or voluntarily enforces the law to communicate with the patient regarding the disclosure of the incident, the cause of incident, the compensation plan, and the measures to prevent the recurrence in the adverse incident that serious harm to the patient. In Korea, the concern about patient safety incidents has been amplified, and as the importance of communication between the medical personnel and patient has been recognized, the revision bill for the "Patient Safety Act", which adopted the U.S.A apology or disclosure law, was submitted to the National Assembly. The purpose of this study was to critically review the contents of the revised legislation based on the analysis of the apology law and disclosure law in U.S.A. and to provide implications for future legislative direction.

Seismic Behavior and Estimation for Base Isolator Bearings with Self-centering and Reinforcing Systems (자동복원 및 보강 시스템과 결합된 면진받침의 지진거동과 평가)

  • Hu, Jong Wan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1025-1037
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    • 2015
  • Flexible base isolation bearings that separate superstructure from ground have been widely used in the construction field because they make a significant contribution to increasing the fundamental period of the structure, thereby decreasing response acceleration transmitted into the superstructure. However, the established bearing devices installed to uphold the whole building give rise to some problems involved with failure and collapse due to lack of the capacity as modern structures are getting more massive and higher. Therefore, this study suggests new isolation bearings assembled with additional restrainers enabled to reinforcing and recentering, and then evaluates their performance to withstand the seismic load. The superelastic shape memory alloy (SMA) bars are installed into the conventional lead-rubber bearing (LRB) devices in order to provide recentering forces. These new systems are modeled as component spring models for the purpose of conducting nonlinear dynamic analyses with near fault ground motion data. The LRB devices with steel bars are also designed and analyzed to compare their responses with those of new systems. After numerical analyses, ultimate strength, maximum displacement, permanent deformation, and recentering ratio are compared to each model with an aim to investigate which base isolation models are superior. It can be shown that LRB models with superelastic SMA bars are superior to other models compared to each other in terms of seismic resistance and recentering effect.

Study on Compass, Carpenter's square, The Beam of Balance and the Weight of balance[規矩權衡] in "Somun(素問).Maekyojeongmiron(脈要精微論)" ("소문(素問).맥요정미론(脈要精微論)"의 규구충권(規矩衡權)에 대한 연구)

  • Lee, Hye-Yeon;Kang, Jung-Soo
    • Journal of Korean Medical classics
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    • v.23 no.1
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    • pp.101-114
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    • 2010
  • In the perspective of the correspondence of heaven and man[天人相應], people live through Gi of heaven and earth[天地之氣], and the human body which is a small universe[小宇宙] itself receives influence while sympathizing with the Gi and heaven[天氣]. So with unexpected incident of the Eum and Yang, four season[陰陽四時], ups and downs of warmth of cold and chilliness of warm[寒熱溫涼] differs, and the position of Gi of human[人氣] changes, regimen and application of acupuncture, and images[象] of the pulse changes. In "Maekyojeongmiron(脈要精微論)", ups and downs of Eum and Yang changes by four season[四時], and correspondence of ups and downs of pulse law is explained with compass, carpenter's square, the beam of balance and the weight of balance[規矩權衡]. Compass[規] is a measure of instrument that can draw a circle, like regulating the measure and differing the center of the circle and diameter and drawing a circle, compass is a image of Gi of Yang[陽氣] that was staying deep inside the body in winter stretching out by big fault[太過不及] of year and energy[元氣] of human in spring. Carpenter's square[矩] is a instrument that draws direction, which is a image of Gi of Yang flourishing in summer and when it gets highly flourished, again the Gi of Eum[陰氣] comes alive and falls. The beam of balance[衡] is a scale, like a scale that tilts at once when one side is slightly heavy, the beam of balance is a image Gi of yang that is fully flourished in summer and about to descent again, which is just about to fall but not going down yet. The weight of balance [權] is a image of gi of yang which as descent to the bottom and staying in the deepest place. compass, carpenter's square, the beam of balance and the weight of balance is not a direct pulse image[脈象], but standard image of pulse of pulse corresponding to the Gi of human[人氣] that changes by four season, and the explanation includes the pulse image of four season like the taut, full, floating, deeply gather[弦鉤浮營] of "Okgijinjangron(玉機眞藏論)" or taut, full, skip, float, deep [弦鉤代毛石] of "Pyeong-ingisangron(平人氣象論)". So with compass, carpenter's square, the beam of balance and the weight of balance, can judge is human correspond in Eum and Yang, four seasons, this is importantly used in examination of pulse[診脈] with existence and nonexistence, and prognosis of illness.

Occurrence and Mineralogy of Sericite Deposit in the Hongjesa Granite from the Bonghwa Area in Kyungsangbuk-do, Korea (경북 봉화지역 홍제사 화강암 내에 배태하는 견운모광상의 산상 및 구성광물)

  • Oh, Ji-Ho;Hwang, Jin-Yeon;Koh, Sang-Mo;Kwack, Kyu-Won;Lee, Hyo-Min;Chi, Se-Jung
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.1
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    • pp.67-83
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    • 2008
  • The sericite ore deposits formed in the Precambrian granitic rock at the Bonghwa area, Kyungsangbuk-do, South Korea. The geochemical and mineralogical characteristics of sericite occurred in Daehyun and Seonghwang mine were analyzed using petrographic microscope, XRD, EPMA, XRF and ICP. An alteration mechanism was also studied. Sericitization occurred within the granitic rock by hydrothermal alteration. From the careful study on the occurrence and mineral assemblage, four alteration zone were clearly identified. These zones reflect progressive hydrothermal alteration process. All sericites belong to $2M_1$ polytype and their mineralogical and geochemical properties are close to illite. The sericite ores show various colors, but the characteristics of major element compositions and crystal structures are not different. The trace element analysis, however, indicates that the difference in color attribute to the abundance of Cr and Ti: bluish green colored sericite are enriched in Cr and blackish green colored sericite enriched in Ti. The formation of sericite ore deposit in the granitic rocks are closely relate to fracture system such as fault and joint. It is considered that the sericite ore deposits in this area were formed by very simple hydrothermal alteration occurred along the fracture zones in granitic rocks with absence of other hydrothermally altered minerals such as kaolin and pyrophyllite.

A Study of a Fast Booting Technique for a New memory+DRAM Hybrid Memory System (뉴메모리+DRAM 하이브리드 메모리 시스템에서의 고속부팅 기법 연구)

  • Song, Hyeon Ho;Moon, Young Je;Park, Jae Hyeong;Noh, Sam H.
    • Journal of KIISE
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    • v.42 no.4
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    • pp.434-441
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    • 2015
  • Next generation memory technologies, which we denote as 'new memory', have both non-volatile and byte addressable properties. These characteristics are expected to bring changes to the conventional computer system structure. In this paper, we propose a fast boot technique for hybrid main memory architectures that have both new memory and DRAM. The key technique used for fast booting is write-tracking. Write-tracking is used to detect and manage modified data detection and involves setting the kernel region to read-only. This setting is used to trigger intentional faults upon modification requests. As the fault handler can detect the faulting address, write-tracking makes use of the address to manage the modified data. In particular, in our case, we make use of the MMU (Memory Management Unit) translation table. When a write occurs to the boot completed state, write-tracking preserves the original state of the modified address of the kernel region to a particular location, and execution continues. Upon booting, the fast booting process restores the preserved data to the original kernel region allowing rapid system boot-up. We develop the fast booting technique in an actual embedded board equipped with new memory. The boot time is reduced to less than half a second compared to around 15 seconds that is required for the original system.

A Study on Searching Algorithm for Malfunction Pattern of Protection Devices in Distribution System with PV Systems (태양광전원이 연계된 배전계통 보호협조기기의 부동작패턴 탐색알고리즘에 관한 연구)

  • Kwon, Soon-Hwan;Tae, Dong-Hyun;Lee, Hu-Dong;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.652-661
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    • 2020
  • Recently, the Korean government developed the RE3020 (renewable energy) policy to overcome environmental problems, such as fine dust, climate change, and large-scale PV systems interconnected with a distribution system. When a large-scale PV system is interconnected in the distribution system, however, a malfunction can occur, and the protection devices may not be operated because of the dividing effect depending on the magnitude and direction of fault current as well as connection types and location of the PV system. Therefore, this paper proposes a search algorithm for the malfunction pattern of protection devices based on various scenarios, when large-scale PV systems are operated and interconnected in a distribution system. This paper presents a malfunction mechanism of protection devices according to the installation locations of recloser (R/C). Furthermore, the modeling of a distribution system with large-scale PV systems was performed using Off-DAS S/W, and the malfunction patterns of protection devices were analyzed based on a range of scenarios. From the simulation results with the proposed model and algorithm for searching for protection devices, it was confirmed that they are useful and effective in identifying a malfunction phenomenon depending on the installation location of the R/C and connection type of PV system.

Hydrothermal Gold mineralization of the trabong district, vietnam : Mineralogical and geochemical study (베트남 짜봉(Trabong) 지역의 열수 금 광화작용 : 광물 및 지화학적 연구)

  • 한진경
    • Economic and Environmental Geology
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    • v.32 no.2
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    • pp.129-139
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    • 1999
  • Hydrothermal gold deposits of the Trabong district in Vietnam occur as single-stage quartz $\pm$ calcite veins (0.3-1.2 m thick) which fill fault fractures in graphite-bearing gneiss and schist of the Chulai Complex and Kham Duc Formation of the Proterozoic age. Ore grades are 1.3 to 92.4 g/ton Au. Ore mineralogy is very simple, consisting mainly of pyrite with minor amounts of base-metal sulfides and electrum. Gold grains occur in two assemblages as follows: (1) early, Fe-rich (7.2-10.4 mole % FeS) sphalerite + electrum (50.4-64.3 atom % Au) assemblage occurring as inclusions in pyrite; (2) late, Fe-poor «4.7 mole % FeS) sphalerite + galena + electrum (47.6-81.7 atom % Au) assemblage occurring along fractures of pyrites. Based on fluid inclusion data and thermochemical considerations of ore mineral assemblages, ore minerals were formed at high temperatures (about $230^{\circ}C$ to $420^{\circ}C$) from $H_{2}O-CO_{2}(-CH_{4})$-NaCI fluids with the sulfur fugacity of about $10^{-6}$ to $10^{-10}$ atm. Fluid inclusion data also indicate that ore mineralization occurred mainly as a result of fluid unmixing accompanying $CO_2$ effervescence. Calculated oxygen and measured hydrogen isotope compositions of mineralizing waters (${\delta}^{18}O_{V-SMOW}$ values = 5.3 to 8.6$\textperthousand$, ${\delta}D_{V-SMOW}$ values = - 60 to - 52$\textperthousand$), along with the sulfur isotope compositions of vein sulfides (${\delta}^{34}S_{CDR}$ values = - 1.2 to 2.8$\textperthousand$) and carbon isotope compositions of inclusion $CO_2$ (${\delta}^{13}C_{PDB}$ values = - 4.7 to - 2.0$\textperthousand$) indicate that the high temperature (mesohypothermal) gold mineralization formed from a magmatic fluid.

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