• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.991-997
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• 2004

In this paper, we propose the architecture of modem receiver to fabricate HomePNA 2.0 chip. HomePNA suffers from inferior channel because of bridge tap, the effect of amateur HAM band and so on. To transfer data over such channel, HomePNA 2.0 uses training sequence to equalize channel and uses FD-QAM optionally as modulation method. So modem receiver demodulate QAM based signal and needs optimum architecture that fully uses these transmission feature. As a result of research, we define 2 mode function of modem receiver depending on TX/RX state. In this paper, particularly, we show the algorithm of equalizer, carrier phase recovery and frame synchromzationblock and propose architecture that improve the performance of channel equalization and is stable in operation. In the end, we estimate the performance of proposed HomePNA2.0 modem receiver over HomePNA TEST LOOP using SPW program.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.6
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• pp.615-620
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• 2013

There is considerable interest in developing energy sources capable of larger power densities. In our previous works, we proved that by coupling an exothermic chemical reaction with 1D nanostructures, a self-propagating reactive wave can be driven along its length with a concomitant electrical pulse of high specific power, which we identified as a thermopower wave. Herein, we discuss details about many different aspects of a thermopower wave. Different alignment degree in vertically aligned CNT films is evaluated in the reactive wave speed and correlated with its thermal reaction that affects the change in the magnitude of energy generation. The effects of the temperature-dependent properties of chemical fuels and CNTs are evaluated. Furthermore, we explore the convection and radiation portions in this thermal wave as well as the synchronization between the thermal reaction transfer and the oscillation of the electrical signal.

• Journal of the Korea Society for Simulation
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• v.22 no.2
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• pp.53-62
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• 2013

Cloud environment is one in the field of distributed computing and it consists of physical nodes and virtual nodes. In distributed cloud environment, an optimal path search is that each node to perform a search for an optimal path. Synchronization of each node is required for the optimal path search via fast data transmission because of real-time environment. Therefore, a quantization technique is required in order to guarantee QoS(Quality of Service) and search an optimal path. The quantization technique speeds search data transmission of each node. So a main server can transfer data of real-time environment to each node quickly and the nodes can perform to search optimal paths smoothly. In this paper, we propose the quantization technique to solve the search problem. The quantization technique can reduce the total data transmission. In order to experiment the optimal path search system which applied the quantized data transmission, we construct a simulation of cloud environment. Quantization applied cloud environment reduces the amount of data that transferred, and then QoS of an application for the optimal path search problem is guaranteed.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3063-3076
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• 1998

To facilitate presentations of various media and transfer their implicit meaning efficiently, needed are effective development techniques for representing and manipulation temporal and spatial informations between multimedia data. Especially, these emporal and spatial informationsl are so deeply related with each other that it is required to have the integrated mehod for their representation. This paper suggests the Presentation Synchronization Trdd(PST) which represents their temporal and spatial informationsl and the efficient presentation model as traversing this PST. In this model, without knowing the specific user's interface or any script languages, the user can write the presentation scenario only based on allen's tecporal specification. This model has a characteristic of allowing user's inputs that may dynamically modify the presentation sequence in presentation time. As through the renmining steps of consistency checking for their relations. PST generation, and PST traversing step, this model provides users with simple and effective presentation of multimedial data by having them be presented auton\matically.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.3
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• pp.1-8
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• 2000

This paper presents a simulation model of the Quadrature detector to demodulate FSK signal, which is widely used in wireless paging system for its simple hardware implementation and economics of It fabrication. Quadrature detecter has nonlinear phase characteristic for changes linear changes of input signal frequency. So until now Quadrature detector system analysis remained a difficult problem and performance analysis has not been carried out adequately On these backgrounds, this paper presents the FSK signal demodulation process using Quadrature detector and optimal performance derived from digital simulation technique. First, PSN(Phase Shift Network) which is composed of analog RLC tank circuit is transformed into its equivalent digital transfer function using First-order-hold theorem. Though the demodulated outputs of the Quadrature detector for 4FSK are 4-level signals, only 2 comparators are used and it is shown that optimal performance can be obtained by choosing operation parameter Q value and threshold level decision which are proposed herein.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.3
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• pp.245-255
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• 2023

Time comparison techniques are necessary for generating and keeping Coordinated Universal Time (UTC) and distributing standard time clocks. Global Navigation Satellite System (GNSS) Common View, GNSS All-in-View, Two-Way Satellite Time and Frequency Transfer (TWSTFT), Very Long Baseline Interferometry (VLBI), optical fiber, and Network Time Protocol (NTP) based methods have been used for time comparison. In these methods, GNSS based time comparison techniques are widely used for time synchronization in critical national infrastructures and in common areas of application such as finance, military, and wireless communication. However, GNSS-based time comparison techniques are vulnerable to jamming or interference environments and it is difficult to respond to GNSS signal disconnection according to the international situation. In response, in this paper, Code-Division Multiple Access (CDMA) based All-to-All TWSTFT operation method is proposed. A software-based simulation platform also was designed for performance analysis in multi-TWSTFT signal environments. Furthermore, code and carrier measurement jitters were calculated in multi-signal environments using the designed simulation platform. By using the technique proposed in this paper, it is anticipated that the TWSTFT-based time comparison method will be used in various fields and satisfy high-performance requirements such as those of a GNSS master station and power plant network reference station.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.177-182
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• 2006

This study was conducted to investigate the effects of melengesterol acetate (MGA) and $PGF_{2{\alpha}}$ administrations on serum progesterone level, synchrony of estrus and conception rates in Han-woo. Firstly, ten heifers and one freematin were fed 0.5 mg MGA/day for 14 days in a grain carrier, and after 19 days of MGA feeding, a single injection of 25 mg $PGF_{2{\alpha}}$ were treated. Blood samples were collected to evaluate serum progesterone concentrations from the start of feeding of MGA until the end of feeding and subsequent estrous detection and artificial insemination (AI) at 3 days intervals, and on days of $PGF_{2{\alpha}}$ injection, estrous detection, AI, and 15th and 60th days after AI. The level of progesterone in the blood began to increase from 7 days after MGA feeding, and 9 days after feeding it became 5.4 ng/ml and maintained that level thereafter. On the 33th day when the $PGF_{2{\alpha}}$ was injected, it reached the peak level of 7.6 ng/ml. However, 2-3 days after $PGF_{2{\alpha}}$ injection, it dropped to 1.4 ng/ml drastically (p<0.05). Secondly, one hundred and ninety four Hanwoo heifers or cows were divided into two groups to compare estrous induction and conception rates: the one treated with MGA and $PGF_{2{\alpha}}$, (n=104) and the other with $PGF_{2{\alpha}}$ treatment (two injections at 11 days interval, n=90). The heifers or cows treated with MGA and $PGF_{2{\alpha}}$ were identical to those used as above. The percentages of heifers or cows showed estrus were higher in the $MGA+PGF_{2{\alpha}}$ treatment (91.3%) than in the $PGF_{2{\alpha}}$ treatment (72.2%, p<0.05). Conception rates were also higher in the $MGA+PGF_{2{\alpha}}$ treatment (94.2%) than in the $PGF_{2{\alpha}}$ treatment (88.9%, p<0.05). The results of this experiment indicate that estrus synchronization using $MGA+PGF_{2{\alpha}}$ is more effective than that using $PGF_{2{\alpha}}$ (two injections) in Hanwoo.

• Journal of Embryo Transfer
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• v.23 no.4
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• pp.251-255
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• 2008

The aim of the present recent study was to compare the protein patterns in the vaginal mucus of Hanwoo cattles during spontaneous and CIDR induced-estrus. Ten cattles, who had been observed in estrus, received no treatment and served as the group of cattles with normal spontaneous estrus. Thirteen cattles in the CIDR received an CIDR insert on day 14 were removed and cattles were injected GnRH on day 15. Vaginal mucus samples were collected from all cattles at the same time the single AI in cattles with spontaneous estrus and the AI in cattles with induced estrus. Spontaneous and CIDR-induced estrus vaginal mucus samples were analyzed on two different array surfaces: cation-exchange (CM10), anion-exchange (Q10). In addition, using the NaCl solution by which the proteins combined after washing are 0.5, 1 and 2 M, it was fractionated and a protein was collected successively. The results are summarized as follows: 1) Ionic surfaces chemistries (Q10 and CM10) gave the best results in terms of detectable protein peaks, with more than 100 protein peaks in the two fractions and under each condition. 2) Protein mass spectrometer using 11 different proteins in protein identification of 7 were able to determine the protein. List of identified proteins as follows; Ribosome-binding protein 1, GRIP 1-associated protein 1, Katanin p60 ATPase-containing subunit A-like 1, Protein FAM44A, DUF729 domain-containing protein 1, Prolactin precursor, Dihydrofolate erductase. Conclusively, on the basis of this study, protein expression in the vaginal mucus could be used as an indicator for time of estrus manifestation in order to increase conception rates by applying AI at an optional time.

• Journal of Embryo Transfer
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• v.26 no.4
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• pp.271-276
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• 2011

This study was focused on improvement of milk production in Mongolian dairy industry by artificial insemination (AI) technology, supported by ODA of KOICA in Republic of Korea. This program was started in January 2009 and it is in $3^{rd}$ years. This manuscript summarized the data especially on estrus synchronization and pregnancy establishment in dairy cows (Holstein) this year. A total of 81 dairy cows from 4 private farms (38 from Undarmal milk and that of 30, 8 and 5 dairy cows from Onjin (Enkhbayer), Jargalant, and BRM School farms respectively) were synchronized with 5 ml Lutalyse (i.m.) in the dump of dairy cows and then estrus was detected 2 to 3 days after $PGF_{2{\alpha}}$ injection. The synchronized dairy cows were inseminated with 0.5 ml dairy frozen semen by conventional artificial insemination (AI) techniques. Pregnancy was diagnosed about 60 days after AI by palpation method. About 96.3% (78/81) of synchronized cows were responded to single $PGF_{2{\alpha}}$ injection. Total 75 over 78 dairy cows (90.1%) inseminated were diagnosed as pregnant. The estrus induction and pregnancy rates were very effective using Lutalyse injection and conventional AI techniques in Mongolian dairy cow. The present results indicated that AI after estrus induction in Mongolian dairy cows could be applied to dairy breeding technology for improving breeding efficiency and milk production of the country.