• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.8A
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• pp.918-927
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• 2004

WCDMA system is 3rd generation wireless mobile system specified by 3GPP. In WCDMA downlink, two power control schemes are operated. One is inner loop power control operated in every slot. Another is outer loop power control based on one frame time. Base station (BS) can estimate proper transmission power by these two power control schemes. However, because each MS's transmission power makes a severe effect on BS's performance, BS cannot give excessive transmission power to the specific user. 3GPP defined Power Control Dynamic Range (PCDR) to guarantee proper BS's performance. In this paper, we propose Adaptive PCDR algorithm. By APCDR algorithm, Radio Network Controller (RNC) can estimate each MS's current state using received signal to interference ratio (SIR). APCDR algorithm changes MS's maximum code channel power based on frame. By proposed scheme, each MS can reduce wireless channel effect and endure outages in cell edge. Therefore, each MS can obtain better QoS. Simulation result indicate that APCDR algorithm show more attractive output than fixed PCDR algorithm.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.3
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• pp.23-31
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• 2010

The increasing demands on low-power, and low-complexity video encoder have been motivating extensive research activities on distributed video coding (DVC) in which the encoder compresses frames without utilizing inter-frame statistical correlation. In DVC encoder, contrary to the conventional video encoder, an error control code compresses the video frames by representing the frames in the form of syndrome bits. In the meantime, the DVC decoder generates side information which is modeled as a noisy version of the original video frames, and a decoder of the error-control code corrects the errors in the side information with the syndrome bits. The noisy observation, i.e., the side information can be understood as the output of a virtual channel corresponding to the orignal video frames, and the conditional probability of the virtual channel model is assumed to follow a Laplacian distribution. Thus, performance improvement of DVC systems depends on performances of the error-control code and the optimal reconstruction step in the DVC decoder. In turn, the performances of two constituent blocks are directly related to a better estimation of the parameter of the correlation channel. In this paper, we propose an algorithm to estimate the parameter of the correlation channel and also a low-complexity version of the proposed algorithm. In particular, the proposed algorithm minimizes squared-error of the Laplacian probability distribution and the empirical observations. Finally, we show that the conventional algorithm can be improved by adopting a confidential window. The proposed algorithm results in PSNR gain up to 1.8 dB and 1.1 dB on Mother and Foreman video sequences, respectively.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.44-54
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• 2005

Most advanced countries in GIS field have established and managed georeferenced socioeconomic data systematically and made a great profit on various social and economic areas. In Korea, however, socioeconomic geographical information is relatively poor compared to systems related to geographical and topographical features. This is mainly due to the characteristics of the process from the construction to the utilization of socioeconomic data. That is, from the stage of data construction, socioeconomic data require solutions for frequent changes compared to data on geographical and topographical features and, because of difficulties in marking the positions of individual entities, information is built up through setting appropriate spatial units of aggregation. In the stage of data utilization, the data often need to be combined with other types of socioeconomic data due to the complexity of socioeconomic phenomena. Thus, the this study examined usability of GIS in socioeconomic fields and the spatial dimension of socioeconomic information through representative cases of GIS in developed countries and, based on the results, derived data requirements for socioeconomic GIS found in the construction and utilization of data and proposed solutions for the requirements.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.71-79
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• 2014

In this paper, the microstrip array antenna is studied to replace the parabolic antenna in the direct satellite reception. A microstrip array antenna has been used in extremely limited area, but if it is applied to practical life like a direct satellite reception antenna, we expect that it will be used in various way. First of all, if we use a microstrip array antenna for a direct satellite reception antenna, it should be guaranteed characteristics of broadband frequency. Therefore, the goal of this paper is designing technique an antenna which guarantees broadband frequency band for a direct satellite reception. In this paper, the proposed microstrip antenna is fed by orthogonal two feed lines to a rectangular patch and a sequentially rotated feeding technique is designed proposed for a good axial ratio in broadband frequency band. The rectangular patch is designed to satellite reception band, and the width and length are W=L=8.9 mm ($0.352{\lambda}o$) respectively. The antenna's ground plane has dimensions of $250{\times}250mm$. The experimental results verify that the proposed antenna had the axial ratio of above 1dB broader than that of the conventional feeding antenna. In order to verify the performance, a $8{\times}8$ array having two pairs was fabricated and tested. The maximum gain is 20.8 dB, the sidelobe level confirm less than -10 dB. It is verified by link budget calculation that C/N=6.7 dB can be obtained for domestic use if this proposed antenna is used in Koreasat reception system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.6 s.109
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• pp.519-528
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• 2006

This thesis is regarding of fabricating wibro PAM. First of all, we need to set specification based on link budget for wibro communication circumstance in order to develop PAM, then we decided specification concerning of wibro PAM by considering TTAS_Ko_06_0082R1 which is standarded in Korea, and IEEE Std. 802. 16d/e which is international standard. We selected the Doherty structure to increase efficiency, and pre-distorter structure to increase linearity. The fabricated PAM has not only a result of $26.5dB{\pm}1.0dB$ gain characteristics and maximum of -14 dB return loss characteristics in full frequency bands and full output ranges, but also a result of 37 dBc at 4 tone IMD characteristics which is improved result of 843 and a result of 31 dBc spurious characteristics which is improved result of 5 dB at 4.77 MHz offset point in status of having 27 % efficiency in the 26 dBm high power amplifier output signal. We confirmed the suggested structure is better than others by comparing with normal structure, balanced structure and Doherty structure without predistorter.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.767-776
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• 2006

Corresponding author:Deukhwan Lee, Department of Animal Life Resources, Hankyong National Univ. Seokjeong-dong Anseong-si Gyeonggi-do, Rep. of Korea 456-749Tel: 031-670-5091, Fax: 031-676-5091, E-mail : dhlee@hknu.ac.krGeneral performance with including environmental and management effects on linear type traits in Holstein cows were investigated. 115,646 valid records measured from cows over 1 yrs of age by Korean Animal Improvement Association from 2000 to 2004 were used for this study. Farm, appraisal year-month, appraisal person should affect linear type and scoring traits. Most of type traits and scoring traits would be significantly affected by parity and lactation stage after absorbing farm-appraisal year-month-person effects. Otherwise, some traits such as traits related to udder would be affected by registration criteria. However, interval of appraisal time and milking time would not affect these traits. The scores related to udder, teat placement and foot angle would be positively related to parity. Final score would be optimized at cows of 2nd and 3rd parities. Dairy form, front teat placement, rear udder height, rear udder width and final score would show similar to pattern of lactation curve at lactation stage. Dairy capacity composite index would also show similar to lactation curve. This result would be indicated that more concise standardizing system for linear type scoring rules would be needed. Furthermore, correcting system for parity and lactation stage would be needed because this factor should affect physiological status, specially, udder status.

• The Journal of Industrial Distribution & Business
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• v.10 no.9
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• pp.37-43
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• 2019

Purpose - The self quality inspection which is mandatory in Republic of Korea can play an important role in promoting food safety, but the cost for self quality inspection is also a big burden especially for small businesses. In addition, excessive or duplicated inspection costs resulting from the standard gaps of various ministries and agencies ultimately effect negative social utility. Thus, this paper aims to suggest ways to improve the analysis of self quality inspection for the Ready-to-Eat Foods in terms of dried laver, in order to reduce costs caused by overinclusion. Research design, data, and methodology - The focus of interest is seaweed in Kimbab, which is to be exempted from the Vibrio parahaemolyticus test on the three grounds. First, existing literature provides little support for the necessity of performing a microbiological test. Second, laver products do not require the V.parahaemolyticus test by international standards such as the CODEX. Third, no case was found for seaweed products on the list of information on failed food items over the 2015~16 period. Results - Other types of seaweed such as exportable and seasoning seaweed are not subject to the test. Hence, exclusion of the V.pahaemolyticus test on seaweed is a valid point, bringing about large expected cost savings to many small businesses. Conclusions - Based on a complete survey of 75 food-testing agencies from March 20th to 30th, 2018, this paper finds that the proposed revision of the Kimbab test is likely to save an average of 130,000 won per business per year. Especially, in the case of the testing fee of Salmonella spp.(n,c,m,M), the cost difference by agencies was found to be up to five times. The regional gap in testing fees can be considered an unfair barrier. Accordingly, it is necessary to examine whether the testing fee is set at an appropriate level through the cost-extraction program proposed by the Ministry Food and Drug Safety. Hence, the survey results also point out that harmonization of testing fees charged by different food-testing agencies is appropriate with respect to transparency and efficiency.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.818-823
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• 2015

In this study, FT reaction in a microchannel was simulated using computational fluid dynamics(CFD), and sensitivity analyses conducted to see effects of channel geometry variables, namely, process channel width, height, gap between process channel and cooling channel, and gap between process channels on the channel temperature profile. Microchannel reactor considered in the study is composed of five reaction channels with height and width ranging from 0.5 mm to 5.0 mm. Cooling surfaces is assumed to be in isothermal condition to account for the heat exchange between the surface and process channels. A gas mixture of $H_2$ and CO($H_2/CO$ molar ratio = 2) is used as a reactant and operating conditions are the following: GHSV(gas hourly space velocity) = $10000h^{-1}$, pressure = 20 bar, and temperature = 483 K. From the simulation study, it was confirmed that heat removal in an FT microchannel reactor is affected channel geometry variables. Of the channel geometry variables considered, channel height and width have significant effect on the channel temperature profile. However, gap between cooling surface and process channel, and gap between process channels have little effect. Maximum temperature in the reaction channel was found to be proportional to channel height, and not affected by the width over a particular channel width size. Therefore, microchannels with smaller channel height(about less than 2 mm) and bigger channel width (about more than 4 mm), can be attractive design for better heat removal and higher production.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.8
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• pp.42-50
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• 2007

This paper presents design methods for dual-frequency(2.4/5.8GHz) active receiving antennas. The proposed active receiving antennas are designed to interconnect the output port of a wideband antenna to the input port of an active device of High Electron Mobility Transistor directly and to receive RF signals of 2.4GHz and 5.2GHz simultaneously where the impedance matching conditions are optimized by adjusting the length of $1/20{\lambda}_0$(@5.8GHz) CPW transmission line in the planar antenna The bandwidth of implemented dual-frequency active receiving antennas is measured in the range of 2.0GHz to 3.1GHz and 5.25GHz to 5.9GHz. Gains are measured of 17.0dB at 2.4GHz and 15.0dB at 5.2GHz. The measured noise figure is 1.5dB at operating frequencies.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.202-208
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• 2012

Fetal heart rate monitoring is important information to assess fetal well-being. Non-invasive fetal ECG (electrocardiography) can be derived from maternal abdominal signal. And various promising signal processing methods have been introduced to extract fetal ECG from mother's composite abdominal signal. However, non-invasive fetal ECG monitoring still has not been widely used in clinical practice due to insufficient reliable measurement and difficulty of signal processing. In application of signal processing method to extract fetal ECG, it might be lower signal to noise ratio due to time varying white Gaussian noise. In this paper, time varying Kalman smoother is proposed to remove white noise in fetal ECG and its feasibility is confirmed. Wiener process was set as Kalman system model and covariance matrix was modified according to white Gaussian noise level. Modified error covariance matrix changed Kalman gain and degree of smoothness. Optimal covariance matrix according to various amplitude in Gaussian white noise was extracted by 5 channel fetal ECG model, and feasibility of proposed method could be confirmed.