• Culinary science and hospitality research
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• v.15 no.4
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• pp.47-55
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• 2009

Gochujang sauces were prepared with 5, 10, 15, and 20% concentrated pomegranate juice(CPGJ) and analyzed with the control for quality characteristics such as proximate composition, viscosity, pH, acidity, $^{\circ}Brix$, $^{\circ}Brix$/acidity ratio, color, and sensory qualities in order to determine the optimal ratio of CPGJ in the formulation. Moisture content, crude ash, viscosity, pH, Brix/acidity decreased, while acidity, Brix increased with increasing CPGJ content. In terms of color, lightness and yellowness decreased as CPGJ content increased however, the control group had significantly(p<0.05) higher redness than the CPGJ samples. For the sensory evaluation, color was not significantly(p>0.05) different among the samples. As the CPGJ content increased, flavor, viscosity, and overall acceptability decreased, whereas sourness, acrid taste, bitterness, astringency, and off-flavor increased. In conclusion, the results indicate that the addition of 10% CPGJ to Gochujang sauce is optimal, and provides good physiological properties as well as reasonably high overall acceptability.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.813-822
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• 2009

We have investigated operation of a 1:2:2 asymmetric 3-stage Doherty PA(Power Amplifier) and implemented using the Freescale's 4 W, 10 W PEP LDMOSFETS at 1 GHz. By employing the three peak efficiency characteristics, compared to the two peak N-way Doherty PA, the asymmetric 3-stage Doherty can overcome the serious efficiency degradation along the backed-off output power region and maximize the average efficiency for the modulation signal. To maximize the efficiency characteristic, the inverse class F PA has been designed as carrier and peaking amplifiers. Furthermore, to extract the proper load modulation operation, the adaptive gate bias control signal has been applied to the two peaking PAs based on the envelope tracking technique. For the 802.16e Mobile WiMAX(World Interoperability for Microwave Access) signal with 8.5 dB PAPR(Peak to Average Power Ratio), the proposed Doherty PA has shown 55.46 % of high efficiency at an average output power of 36.85 dBm while maintaining the -37.23 dB of excellent RCE(Relative Constellation Error) characteristic. This is the first time demonstration of applying the saturated PA and adaptive gate bias control technique to the asymmetric 3-stage Doherty PA for the highly efficient transmitter of the base-station application.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.139-146
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• 1989

The purpose of this study was to examine the qualitative variation of human fetal-cord sera (HCS) and to accept the sera in human lVF-ET program. One hundred and sixteenth RCS were tested with 1772 2-cell embryos of F1 (C57BL x CBA) virgin mice, Ten to sixteenth embryos were cultured in m-KRB medium with a aliquot of each serum (10%, v/v) or with bovine serum albumin(O.4%, w/v) as a control medium. Embryonic development were recorded at every 24hr for 4 days by such events as cellular compaction, cavitation, and hatching. In the control groups of eight assays, 98.1%(106/ 108) of 2-ce1l embryos developed above expanded blastocyst and the embryonic development was unified through the tests. But the developmental pattern in medium with each serum was various. Namely, the sera that supported development of 100% 2-cell embryos to above morula, early blastocyst, expanded blastocyst and hatching blastocyst was 45,7%(53/116) , 35.3%(41/116), 15.5%08/116.) and 6.9-%(8/116), respectively. And the sera that supported development of above 80% 2-cell embryos to the each embryonic stage was 92.2% (107/116), 83.6%(97/116), 63.8%(74/116) and 36.2%(42/116), respectively. Meanwhile two kinds of toxic pattern to the embryonic development were observed in some sera. The first pattern is that some sera arrested development of most embryos in pre- or post-stage of morula or blastocyst. The second pattern is that some sera promoted or arrested a part of embryos in the same dish. The ability of serum was depended on the batch of serum. Finally we could accept 69%(80/116) of the tested sera for human IVF-ET program. The base line for acceptance was the ability that supported above 80% 2-ce1l embryos to blastocyst. But some deterious sera were contained in this range. We cut off about 10% of the sera (83.6% , 97/116) that passed the baseline. This final percent of sera was similar to that of grade N of this study.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.3
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• pp.19-25
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• 2012

Underwater sensor networks (UWSNs) employ acoustic channels for communications. One of the main characteristics of the underwater acoustic channel is long propagation delay. Previously proposed MAC (medium access control) protocols for wireless sensor networks cannot be directly used in UWSNs due to the long propagation delay. The long propagation delay and uneven nodes deployments cause spatial fairness in UWSNs. Therefore, a new MAC protocol for UWSNs needs to be developed to provide efficient communications. In this paper, we propose an efficient MAC protocol in order to alleviate the fairness problem. In the proposed scheme, when a node receives a RTS packet, it does not immediately send back but delays a CTS packet. The node collects several RTS packets from source nodes during the delay time. It chooses one of the RTS packets based on the queue status information. And then, it sends a CTS packet to the source node which sent the chosen RTS packet. The performance of the proposed scheme is investigated via simulation. Simulation results show that our scheme is effective and alleviates the fairness problem.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.188-198
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• 2013

Maximally flat (MAXFLAT) half-band filters usually have wider transition band than other filters. This is due to the fact that the maximum possible number of zeros at $z={\pm}1$ is imposed, which leaves no degree of freedom, and thus no independent parameters for direct control of the frequency response. This paper describes a novel method for the design of FIR halfband filters with an explicit control of the transition-band width. The proposed method is based on a generalized Lagrange halfband polynomial (g-LHBP) with coefficients parametizing a 0-th coefficient $h_0$, and allows the frequency response of this filter type to be controllable by adjusting $h_0$. Then, $h_0$ is modeled as a steepness parameter of the transition band and this is accomplished through theoretically analyzing a polynomial recurrence relation of the g-LHBP. This method also provides explicit formulas for direct computation of design parameters related to choosing a desired filter characteristic (by trade-off between the transition-band sharpness and passband & stopband flatness). The examples are shown to provide a complete and accurate solution for the design of such filters with relatively sharper transition-band steepness than MAXFLAT half-band filters.

• Korean Journal of Veterinary Service
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• v.38 no.4
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• pp.241-248
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• 2015

This study was aimed to investigate factors that affected the status of wearing personal protective equipment (PPE) for handling poultry carcasses with potential exposure to virulent avian infectious agents. A large outbreak of high pathogenic avian influenza (HPAI) occurred in South Korea in 2014. Many public officers participated for euthanizing and handling livestock carcass. However, several safety issues with using PPE were revealed. Therefore, a questionnaire survey was conducted for 340 people who participated euthanasia and carcass disposal in the place where HPAI mainly occurred in 2014. It was found that 31.8% of the respondents had ever taken off their protective equipment during operations because of its inconvenience. The most inconvenient PPE was goggles (54.6%), followed by mask (20.2%), latex gloves (11.6%), shoe covers (5.9%) and protective clothing (5.3%). The main complaints about this individual PPE was unclear sight, damp emitted toward eye, sweating, tearing easily and sweating, respectively. Considering such problems of PPE, new possible directions for improvement of gloves and goggles were suggested. With newly developed rubber coating fabric gloves and conventionally using latex and fabric gloves, H3N2 influenza virus transmission experiment was conducted. Rubber coating fabric gloves showed similar efficiency for blocking virus transmission with latex laboratory gloves and were not easily torn by sharp claws of chicken. In addition, air flow control safety eyewear was suggested to minimize moisture formation. The air flow control system efficiently suppressed moisture formation inside the goggles. Therefore our study will provide more specific directions about new PPE development for safety protection of actual wearers.

• Journal of Biosystems Engineering
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• v.38 no.4
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• pp.228-239
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• 2013

Purpose: The objectives of this study were to develop an automated disinfectant dilution system, and an automated data management system for spraying amount for resolving uncertainty problem. Methods: Proper diluting rate was made by a controlled volume pump for liquid disinfectant and a screw conveyer pump for solid disinfectant. The water capacity of disinfecting system of 400 L was controlled by two water level sensors. The water quantity of water tank was controlled by the signals which were produced by the water level sensors. Signals were processed by Labview Programming, and ON/OFF of solenoid valve that was used for controlling water supplying to water tank, was controlled by SSR. The operating time of pumps for disinfectant was controlled quantitatively. A turbine flowmeter was used for development of automated measurement system for spraying amount of disinfectant. In order to save the flowmeter data and to control the spraying system, a multi-function data logger was used, and it was processed and saved in Excel file by a program developed in this study. Results: Labview 2010 was used for programming to control the automated measurement system for spraying amount of disinfectant. Results showed that the relationship between flowmeter value and time had a significant linear relationship such as 0.99 of $R^2$. Generally, 6.74 L/s of diluted disinfectant is sprayed for a vehicle passing through the disinfection system (about 15 seconds). Test results showed that average error between the measured spraying amount and the flowmeter data was 50 mL, and the range of error was 1.3%. Since the amount and time of spraying could be saved in real-time by using the spreadsheet files which could not be modified arbitrarily, it made possible to judge objectively whether the disinfection spraying was performed or not. Test results of spraying liquid and solid disinfectant showed that the errors between the measured discharge rate and the theoretical one were ranged within 3-4% for various dilution rates. Conclusions: The disinfection system developed would be working accurately. The automated spraying data base management system satisfied the purpose of this study. The automated dilution process system developed in this study could discharge liquid and solid disinfectant with accurate dilution rate, relatively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.96-103
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• 2000

The voice traffic is one of the most important real-time objects in WATM(Wireless Asynchronous Transfer Mode) networks. In this paper, we propose a new MAC(Medium Access'Control) protocol for the efficienttransmission of voice traffic over WATM networks in the multimedia environment and compare the performanceto existing similar protocols. The new protocol separates the reservation slot period for voice and that for data toguarantee some level of QoS(Quality of Service) in voice traffic. This is denoted by a slot assignment functiondepending on the frame size. According to the characteristics of voice traffic which is repeatedly in silent states,the protocol allocates voice reservation request slots dynamically with respect to the number of silent(off state)voice sources and also sends the first block of talkspurt restarted after silent period with a reservation requestslot to reduce the access delay.The simulation results show that the proposed protocol has better performance than Slotted Aloha in bandwidthefficiency, and can serve a certain level of QoS by the given slot assignment function even when the number ofvoice terminals varies dynamically. This means we can observe that the new MAC protocol is much better thanthe NC-PRMA(None Collision-Packet Reservation Multiple Access) protocol.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.192-199
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• 2009

This study was carried out to investigate the performance of a radio-frequency/vacuum dryer combined with a mechanical compressive load (RF/VC) with a scale of about $3m^3$ during drying board of Azobe (Lophira alata) and Korean red pine (Pinus densiflora). The degree of vacuum of the RF/VC system was maintained at 80~105 torr, and wood temperature was increased from $40^{\circ}C$ at the beginning of drying to $60^{\circ}C$ at the end of drying and the radiofrequency generator was operated with schedule of 7 minute-ON and 3 minute-OFF. The wood temperatures near charge plate always remained higher than those of the control during all of the drying stage, whereas the wood temperature near ground plate always remained lower than those of the controlled. As drying time proceeding, the temperature of the wood near ground plate presented lower than those of the control. Whereas the temperature of the wood near charge plate presented higher than those of the controlled. The final average moisture contents of the Azobe boards stacked near the input side of the RF generator showed slightly lower than those near the opposite side. Those of the wood stacked in the layers near the charge plate were lower than those of near the ground plate. The average length of surface checks of the Azobe boards stacked near the charge plate was very slight, whereas that toward the ground plate represented high values. The efficiency of input energy was simliar with the commercial systems.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.437-442
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• 2015

This study, examined Chilocorus kuwanae for biological control of Saissetia coffeae. We measured basic developmental characteristics of C. kuwanae and its capability to prey on the second-instar larvae of S. coffeae by indoor breeding under the following conditions: $25^{\circ}C{\pm}2^{\circ}C$, humidity $70%{\pm}5%$, and day length 16L : 8D. The average daily consumption of the second-instar larvae of S. coffeae by C. kuwanae adults was approximately 77.5 larvae/day, which was significantly 2.8 and 2.9 times higher than consumption by Chrysoperla carnea and Cryptolaemus montrouzieri, respectively. During the nymphal period, C. kuwanae consumed a total of 659.0 second-instar larvae of S. coffeae. The interaction between C. kuwanae and the second-instar larvae of S. coffeae varied according to their densities, with the increase in C. kuwanae consumption rate noted to decelerate and gradually level off at the maximum, rsembling Holling's Type II functional response. Duration of egg to adult development varied from 21.1 days to nearly 27.9 days at temperatures of $25^{\circ}C{\pm}2^{\circ}C$. Hatchability, pupation rate, and adult emergence were greater than 72.3%, 77.8% and 83.3%, respectively.