• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.4 s.119
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• pp.423-429
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• 2007

The clock recovery module of gap filler for satellite DMB is proposed. Proposed module sustains the output frequency of 10 MHz whether the received signal from the satellite is unstable or cut off within 0.5 sec. The advantages of this module is without frequency tuning at regular interval and low material cost. This module is fabricated by using CPLD as clock recovery IC and new type of loop filter for satisfying the fast lock time and long hold over time simultaneously. The measured performance of the fabricated module has a holdover time of 11 sec at frequency stability less than 0.01 ppm, and phase noise of -113 dBc/Hz at 100 Hz offset.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.577-582
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• 2016

The synchronous TDC(Time-to-Digital Converter) of counter-type using current-conveyor is designed by $0.18{\mu}m$ CMOS process and the supply voltage is 3 volts. In order to compensate the disadvantage of a asynchronous TDC the clock is generated when the start signal is applied and the clock is synchronized with the start signal. In the asynchronous TDC the error range of digital output is from $-T_{CK}$ to $T_{CK}$. But the error range of digital output is from 0 to $T_{CK}$ in the synchronous TDC. The error range of output is reduced by the synchronization between the start signal and the clock when the timing-interval signal is converted to digital value. Also the structure of the synchronous TDC is simple because there is no the high frequency external clock. The operation of designed TDC is confirmed by the HSPICE simulation.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.97-100
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• 2004

Our country has depended on fossil fuel very much according to the Increasing of the demand of the electric power. For instance, if the reduction and freezing caused by the warm gas in earth by the regulation of international environment happen in Korea it will bring about the result of weakness in industrial activity. As a result, it will cause many problems to compete an advanced country which wants to connect environment with the activity of industrial product in their country. The photovoltaic system outputs have peak about a half past 13 o'clock(before and after) mainly in a good weather. The output decreases rapidly from a half past 17 o'clock and PV output doesn't work at six o'clock before the sun rises. The outputs of PV system stops at that time. The frequent degree of harmonics in dwelling house which lots of people live has peak from 19 o'clock to 22 o'clock Harmonics mainly happens at least at night. In recent, many researches about power quality has been studying very hard in order to solve the question, the voltage fluctuating and harmonics as one compensator. In this paper, I suggest the algorithm which can increase the power quality as a rate of operation of this system. This algorithm proves to have effectiveness through computer simulation.

• Interdisciplinary Bio Central
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• v.1 no.1
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• pp.5.1-5.4
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• 2009

This article is an addendum to the authors’ previous article (Kim, J. et al. (2008) Plant Cell 20, 307-319). The instrumentation and software described in this article were used to analyze the circadian leaf movement in the previous article. Here, we provide detailed and practical information on the instrumentation and the software. The source code of the LMA program is freely available from the authors. The circadian clock regulates a wide range of cyclic physiological responses with a 24 hour period in most organisms. Rhythmic leaf movement in plants is a typical robust manifestation of rhythms controlled by the circadian clock and has been used to monitor endogenous circadian clock activity. Here, we introduce a relatively easy, inexpensive, and simple approach for measuring leaf movement circadian rhythms using a USB-based web camera, public domain software and a Leaf Movement Assay (LMA) program. The LMA program is a semi-automated tool that enables the user to measure leaf lengths of individual Arabidopsis seedlings from a set of time-series images and generates a wave-form output for leaf rhythm. This is a useful and convenient tool for monitoring the status of a plant's circadian clock without an expensive commercial instrumentation and software.

• Journal of Engineering Education Research
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• v.13 no.2
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• pp.28-32
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• 2010

The mechanical clock was designed and produced by students as a trial theme of PBL class. The limit of making time is three weeks and main material is limited to paper. Only a basic mechanism drawing is given. As the principle of mechanical clock is not complex and does not need the special knowledge of mechanical engineering, even lower grade student seems to understand enough. This subject can train the skill of knowledge composition, creativity and the problem-solving ability. After execution,the validity and performance as the theme of PBL class was evaluated. As a result, the following findings were obtained. The paper made mechanical clock could be produced in three weeks. And, by additional improvements of the product, the enough strength and stable movement were achieved. Students can learn that many kinds of knowledge through actual experiences of design and making were required in manufacturing the real products. The proposed PBL style class is suitable as an introduction and training subject for lower grade student in department of engineering.

• ETRI Journal
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• v.44 no.5
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• pp.859-874
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• 2022

This paper presents a low-power and lightweight human body communication (HBC) receiver with an embedded dummy electrode for improved signal acquisition. The clock data recovery (CDR) circuit in the receiver operates with a low supply voltage and utilizes a clock phase inversion scheme. The receiver is equipped with a main electrode and dummy electrode that strengthen the capacitive-coupled signal at the receiver frontend. The receiver CDR circuit exploits a clock inversion scheme to allow 0.9-V operation while achieving a shorter lock time than at 3.3-V operation. In experiments, a receiver chip fabricated using 130-nm complementary metal-oxide-semiconductor technology was demonstrated to successfully receive the transmitted signal when the transmitter and receiver are placed separately on each hand of the user while consuming only 4.98 mW at a 0.9-V supply voltage.

• The Journal of Korean Society for School & Community Health Education
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• v.13 no.2
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• pp.107-118
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• 2012

Backgrounds: In order to prevent dental injuries that often occur in child and adolescent, it is intended to investigate and assess actual state of the injury development, present epidemiological background, and consider and discuss for preparing preventive means against the injury development. Purpose: It was attempted to understand major features of dental injuries developing in child and adolescent and indentify high risk factors of dental injuries in child and adolescent. Methods: In this study, 523 cases of computerized data collected as disease entities of dental injuries among 1-18 years old patient visiting S university hospital located in Seoul in 2009 were analyzed and following results were obtained. Results: It was found that the ratio of dental injuries by genders in child and adolescent was 66.14% of male and 33.86% of female. It was shown also that causes of dental injuries by ages were more in order of falling, bumping, chewing, traffic accident, sports, violence, and crash. In addition places where dental injuries occur by ages were home in less than 5 year old group, park, playground, and play yard in 6-11 year old group, park, playground, and play yard also in 12-14 year old group, and stairs, road, and outdoor places such as mountain climbing, beach, and camping in 15-18 year old group. It was found that time rages when dental injuries in child and adolescent often develop were 15-19 o'clock for falling, 15-19 o'clock for crash, 15-19 o'clock for bumping, 19-03 o'clock for violence, 15-19 o'clock for traffic accident, 15-19 o'clock for sports activity, and 15-19 o'clock for chewing. Conclusion: Background of dental injury inducing factors are very complicated and diversified, so deep study and analysis are required for its prediction. Therefore, it seems necessary to identify risk factors by phases such as before, at, and after accident, establish strategies to reduce injury development, and develop and utilize necessary programs.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.11
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• pp.64-74
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• 1999

A new clock skew optimization for clock routing using link-edge insertion is proposed in this paper. It satisfies the given skew bound and prevent the total wire length from increasing. As the clock skew is the major constraint for high speed synchronous ICs, it must be minimized in order to obtain high performance. But clock skew minimization can increase total wire length, therefore clock routing is performed within the given skew bound which can not induce the malfunction. Clock routing under the specified skew bound can decrease total wire length Not only total wire length and delay time minimization algorithm using merging point relocation method but also clock skew reduction algorithm using link-edge insertion technique between two nodes whose delay difference is large is proposed. The proposed algorithm construct a new clock routing topology which is generalized graph model while previous methods uses only tree-structured routing topology. A new cost function is designed in order to select two nodes which constitute link-edge. Using this cost function, delay difference or clock skew is reduced by connecting two nodes whose delay difference is large and distance difference is short. Furthermore, routing topology construction and wire sizing algorithm is developed to reduce clock delay. The proposed algorithm is implemented in C programming language. From the experimental results, we can get the delay reduction under the given skew bound.

• Journal of Photoscience
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• v.9 no.2
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• pp.240-242
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• 2002

In Drosophila melanogaster, it is known that the circadian clock consists of an autoregulatory feedback loop, which includes so-called clock genes, such as per, tim, dClk and cyc and produces periodical expression of per. It is recently suggested, however, that the circadian oscillation without the rhythmical expression of per is involved in the regulation of circadian locomotor rhythms. In the present study, we examined the existence and the property of the possible per-less oscillation using arrhythmic clock mutant flies carrying per$^{01}$, tim$^{01}$, dClk$^{Jrk}$ or cyc$^{01}$. When temperature cycles consisting of 25$^{\circ}$Ｃ and 30$^{\circ}$Ｃ with varying periods (T = 8~32 hr) were given, they showed rhythms synchronizing with the given cycle under constant darkness (DD). per$^{01}$ and tim$^{01}$ flies always showed a peak around 7 hr after the onset of thermophase irrespective of Ts of temperature cycles, while dClk$^{Jrk}$ and cyc$^{01}$ flies did not. In addition, several days were necessary to establish a clear temperature entrainment in per$^{01}$ and tim$^{01}$ flies, when they were transferred from a constant temperature to a temperature cycle under DD. These results suggest that per$^{01}$ and tim$^{01}$ flies have a temperature-entrainable weak oscillatory mechanism. The fact that dClk$^{Jrk}$ and cyc$^{01}$ flies did not show any sign of the endogenous oscillation suggests that the per-less oscillatory mechanism may require CLK and CYC.

• Journal of the Korea Society of Computer and Information
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• v.25 no.1
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• pp.71-77
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• 2020

In this paper, we propose a method in which PingPong256 combines LFSR and variable clock to generate an irregular PRNG and use it for image encryption. PingPong256 is guaranteed an extended period based on the two LFSRs, and the variable clock is a structure that outputs the result of operating a predetermined clock in one operation by referring to the state of the different LFSR. A variable clock is characterized by the difficulty of predicting the output at any time because the choice increases with time. PingPong256 combines the advantages of LFSR and variable clock, the convenience of hardware and software implementation, and the benefits of sensitivity and irregular periods. Also, the statistical safety was verified using the NIST SP800-22, the safety of the proposed method, and the sensitivity of the image change was tested using NPCR and UACI.