• BMB Reports
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• v.33 no.3
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• pp.256-262
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• 2000

In this study the disassembly process of chlorophyII (ChI)protein complexes of a stay-green mutant (ore10 of Arabidopsis thaliana) was investigated during the dark incubation of detached leaves. During this dark-induced senescence (DIS), the Chi loss was delayed in the mutant, while the photochemical efficiency of photosystem II (PSII) or Fv/Fm was accelerated when compared with the wild type (WT) leaves. This indicates that the decrease in Fv/Fm is a separate process and not causally-linked to the degradation of Chi during DIS of Arabidopsis leaves. In the native green gel electrophoresis of the Chi-protein complexes, which was combined with an additional twodimensional SDS-PAGE analysis, the delayed senescence of this mutant was characterized by the appearance of an aggregate at 1 d or 2 d, as well as very stable light harvesting complex II (LHCII) trimers until 5 d after the start of DIS. The polypeptide composition of the aggregates varied during the whole DIS at 5 d. Dl protein appeared to be missing in the aggregates. This result supports the idea of a faster depletion of functional PSH in the mutants compared with WT, as suggested by the earlier reduction of Fv/Fm and the stable Chl a/b ratio in the mutants. At 5 d, the WT leaves also often showed aggregates, but the polypeptide composition was different from those of ore10. The results presented suggest that the formation of aggregates, or stable LHCII trimers in the stay-green mutants, is a way to structurally protect Chi-protein complexes from serious proteolytic degradation. Detailed disassembly processes of Chi-protein complexes in WT and ore10 mutants are discussed.

• Korean Journal of Metals and Materials
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• v.46 no.4
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• pp.257-266
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• 2008

AHydrogen induced cracking (HIC) was phenomenologically studied in terms of the effect of nonmetallic inclusions and hot rolling process parameters. By comparing the level of non-metallic inclusions in two different kinds of commercial grade steels having different HIC resistance, the role of non-metallic inclusions in HIC occurrence was investigated. Change in inclusion morphology and distribution during hot rolling was also studied throughout slab, rolling at austenite recrystallization region (roughing mill; RM) and rolling at austenite non-recrystallization region (finish mill; FM). In addition, the contribution of RM and FM parameters to HIC was investigated from the standpoint of change in inclusion morphology during hot rolling processes. As a result, HIC was closely related to the separation of large complex inclusion during hot rolling process. Large complex inclusions originated from the improper Ca treatment, after which equilibrium composition of slag should have resulted in eutectoid composition. By controlling the equilibrium slag composition equivalent to eutectoid one, HIC resistance could be improved due to the reduced size of inclusions. In addition, change in reduction/pass in RM had an effect on HIC resistance of steels while that in FM did not. Increase in the reduction/pass in the latter stage of RM improved HIC resistance of steels by enhancing the void enclosure around inclusions.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.165-168
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• 2002

As the demand for higher data-rate chip-to-chip communication such as memory-to-controller, processor-to-processor increases, low cost high-speed serial links\ulcorner become more attractive. This paper describes a 0.25-fm CMOS 1.6Gbps/pin 4-level transceiver using Stub Series Terminated Logic for high Bandwidth. For multi-gigabit/second application, the data rate is limited by Inter-Symbol Interference (ISI) caused by channel low pass effects, process-limited on-chip clock frequency, and serial link distance. The proposed transceiver uses multi-level signaling (4-level Pulse Amplitude Modulation) using push-pull type, double data rate and flash sampling. To reduce Process-Voltage-Temperature Variation and ISI including data dependency skew, the proposed high-speed calibration circuits with voltage swing controller, data linearity controller and slew rate controller maintains desirable output waveform and makes less sensitive output. In order to detect successfully the transmitted 1.6Gbps/pin 4-level data, the receiver is designed as simultaneous type with a kick - back noise-isolated reference voltage line structure and a 3-stage Gate-Isolated sense amplifier. The transceiver, which was fabricated using a 0.25 fm CMOS process, performs data rate of 1.6 ~ 2.0 Gbps/pin with a 400MHB internal clock, Stub Series Terminated Logic ever in 2.25 ~ 2.75V supply voltage. and occupied 500 * 6001m of area.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3683-3703
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• 2018

Wireless sensor networks (WSNs) consist of set of sensor nodes. These sensor nodes are deployed in unattended area which are able to sense, process and transmit data to the base station (BS). One of the primary issues of WSN is energy efficiency. In many existing clustering approaches, initial centroids of cluster heads (CHs) are chosen randomly and they form unbalanced clusters, results more energy consumption. In this paper, an energy efficient clustering protocol to prevent unbalanced clusters based on firefly and midpoint algorithms called EEC-FM has been proposed, where midpoint algorithm is used for initial centroid of CHs selection and firefly is used for cluster formation. Using residual energy and Euclidean distance as the parameters for appropriate cluster formation of the proposed approach produces balanced clusters to eventually balance the load of CHs and improve the network lifetime. Simulation result shows that the proposed method outperforms LEACH-B, BPK-means, Park's approach, Mk-means, and EECPK-means with respect to balancing of clusters, energy efficiency and network lifetime parameters. Simulation result also demonstrate that the proposed approach, EEC-FM protocol is 45% better than LEACH-B, 17.8% better than BPK-means protocol, 12.5% better than Park's approach, 9.1% better than Mk-means, and 5.8% better than EECPK-means protocol with respect to the parameter half energy consumption (HEC).

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.102-106
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• 2008

Forensic Marking is the technology that enables the service providers (SP) to identify the illegal digital contents distributors by first inserting markings (data indicating the user information and playback time) in realtime into the digital contents at time of playback of digital contents, and then later by extracting inserted markings from the contents which are illegally captured from the multimedia device such as IPTV STBs and distributed over the Internet. Digital Rights Management (DRM), which is a very popular content protection technology, has the security hole that can be vulnerable because the encrypted digital contents are transformed into their original plaintext forms after the decrypting process on the STBs. Therefore Forensic Marking (FM) has now become a companion content protection solution to DRM. This article describes a new way of tracking up to 4 illegal content users in FM implementation using the blue-difference chroma component of YCbCr color space. This FM technology has many advantages like fast processing time and easy portability to STB devices compared to that of the traditional watermarking processing in the frequency domain.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.814-821
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• 2015

The STEP Cube Lab. classified as a pico-class satellite has been successfully developed as a flight model(FM) to be launched in 2015. Its mission objective is to perform the on-orbit verification of fundamental space core-technologies. In this study, a thermal design concept based on the passive method to achieve the mission objective is introduced. The effectiveness of the thermal design and performance of the satellite has been verified through the acceptance level thermal vacuum test. In addition, to improve the reliability of thermal mathematical model, correlation was performed using the results of thermal balance test. This paper describes a series of process for the thermal vacuum test on the STEP Cube Lab. FM.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.733-744
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• 2016

The legacy methods for converting a business model to a feature model make it difficult to support an automatic transformation due to a dependence on a domain analyzers' intuitions, which hinders the feature oriented development for the integration of feature modeling in business modeling. This paper proposes a method for converting a BPMN business model into a feature model based on syntax. To allow the conversion between the heterogeneous models from BPMN to the FM(Feature Model), it defines the grouping mechanism based activities' syntax, and then makes translation rules and a method based on the element (represent business function) and structure (relationships and process among elements), which are common constructs of their models. This method was applied to an online shopping mall system as a case study. With this mechanism, it will help develop a mechanical or automated structure transformation from the BPMN model to the FM.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.9
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• pp.814-824
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• 2016

The mission objective of STEP Cube Lab. (Cube Laboratory for Space Technology Experimental Project) classified as a pico-class satellite is to find space core technologies researched at domestic industry or university and to verify these technologies on mission orbit. To implement this objective, system level electrical integration and function test (EIT) by using developed flight software were performed in compliance with system requirements. And the effectiveness of the flight model (FM) was verified through launch and thermal vacuum test at acceptance level. This paper will introduce a series of process of electrical function tests for FM EIT, launch and thermal vacuum tests.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.29-38
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• 1992

무인화된 대량생산 체제에서는 transfer line을 이용하게되며, cycle time의 단축을 위하여 측정 및 검사기능이 별도의 station으로 있어 가공후에 부품의 불량여부를 감지한다. 그러나 다품종소량생산체제에서는 FMC 또는 FMS가 적합하며, 이 시스템에 바람직한 감시기능으로서는 기내측정(inter-process)방식을 많이 이용한다. 여기서는 CNC선반과 머시닝센터에 접촉식 센서인 터치프로브(touch probe)를 설치하여 개발한 무인 FMC용 인터프로세스 3차원 측정 및 검사시스템을 소개한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.75-82
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• 2010

This paper presents a wideband ${\Delta}{\Sigma}$ fractional-N frequency synthesizer for a multi-band single chip CMOS RFIC transceivers. A wideband VCO utilizes a 6-bit switched capacitor array bank for 2340~3940 MHz frequency range. VCO frequency calibration circuit is designed for optimal capacitor bank code selection before phase locking process. It finishes the calibration process in $2{\mu}s$ over the whole frequency band. The LO generation block has selectable multiple division ratios of ${\div}2$, ${\div}16$, and ${\div}32$ to generate LO I/Q signals for T-DMB/DAB/FM Radio systems in L-Band (1173~1973 MHz), VHF-III (147~246 MHz), VFH-II (74~123 MHz), respectively. The measured integrated phase noise is quite low as it is lower than 0.8 degree RMS over the whole frequency band. Total locking time of the ${\Delta}{\Sigma}$ frequency synthesizer including VCO frequency calibration time is less than $50{\mu}s$. The wideband ${\Delta}{\Sigma}$ fractional-N frequency synthesizer is fabricated in $0.13{\mu}m$ CMOS technology, and it consumes 15.8 mA from 1.2 V DC supply.