• International Journal of Aeronautical and Space Sciences
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• v.13 no.4
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• pp.491-498
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• 2012

A Ground Based Augmentation System (GBAS) is an enabling technology for an aircraft's precision approach based on a Global Navigation Satellite System (GNSS). However, GBAS is vulnerable to interference, so effective GNSS interference detection and mitigation methods need to be employed. In this paper, an intentional GNSS interference detection and characterization algorithm is proposed. The algorithm uses Automatic Gain Control (AGC) gain and adaptive notch filter parameters to classify types of incoming interference and to characterize them. The AGC gain and adaptive lattice IIR notch filter parameter values in GNSS receivers are examined according to interference types and power levels. Based on those data, the interference detection and characterization algorithm is developed and Monte Carlo simulations are carried out for performance analysis of the proposed method. Here, the proposed algorithm is used to detect and characterize single-tone continuous wave interference, swept continuous wave interference, and band-limited white Gaussian noise. The algorithm can be used for GNSS interference monitoring in an excessive Radio Frequency Interference environment which causes loss of receiver tracking. This interference detection and characterization algorithm will be used to enhance the interference mitigation algorithm.

• Journal of Veterinary Clinics
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• v.11 no.1
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• pp.437-470
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• 1994

These studies were performed to establish more effective surgical method for correcting congenital atresia coli in calves. Distal colon fistulation, proximal colon fistulation and colon anastomosis which could be applied for surgical repair of intestinal obstruction were carried out in goatlings experimentally and in calves with atresia coli clinically. After treatment of the animals clinical signs, blood component values, body weight gain, survival and necropsy findings were observed. In goatlings, clinical signs after colon fistulation were diarrhea, anorexia and vitality loss, and those of proximal colon fistulation group were severer than those of distal colon fistulation group. Surviviability after operation was 9~16 weeks in distal colon fistulation group, 2~8 weeks in proximal colon fistulation group, and 2-3 days in colocolic anastomosis group, respectively. There were no alterations in blood component values among experimental groups. Weight gain rates were 54.6% in distal colon fistulation group and 42.9% in proximal colon fistulation group compared with those of control. Necropsy findings observed in experimental groups were distension of intestine and excessive fluid in abomasum and intestine. Two calves with atresia coli died 1 day and 6 days after operation but one with colon fistulation survived more than two months. Preoperative clinical signs in calves with atresia coli were abdominal distension, progressive anorexia, no defecation and postoperative clinical signs wert diarrhea and periodic abdominal distension. After operation there were no alterations in blood component values between the calf with atresia coli and control calf. Weight gain rate of calf with atresia coli was similar to that of control but revealed the tendency to decrease from the 2nd month after operation. Necropsy findings observed in two calves with atresia coli were intestinal distension. intraluminal excessive fluid, blind atretic sac and absence of intrarectal content. It was concluded that proximal or distal colon fistulation could be available for surgical correction of congenital atresla coli and prognosis of distal colon fistulation was better than of proximal colon fistulation, but that extensive colocolic anastomosis could not be compatible with life in ruminants.

• The Journal of the Acoustical Society of Korea
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• v.31 no.5
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• pp.273-279
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• 2012

In this thesis, a nonlinear compression fitting method was studied for each frequency channel of a 64 channel digital hearing aid. Unlike conventional fitting formula method done from the result of the hearing loss test, the present fitting method uses the auditory threshold of sound pressure measured near the tympanic membrane while ITE (In-The-Ear) hearing aid is fitted into the user's ear canal. Also, the spectral distribution of the voice sound pressure was used for realizing of output sound pressure compression curves against input sound pressure level. Theoretical research results of FFT-iFFT compression algorithm has been evaluated by experimental gain measurements at each different input sound pressure level 50 dB, 70 dB, 90 dB respectively.

• Journal of Multimedia Information System
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• v.5 no.3
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• pp.201-208
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• 2018

High Efficiency Video Coding range extensions (HEVC RExt) is a kind of extension model of HEVC. HEVC RExt was specially designed for dealing the high quality images. HEVC RExt is very essential for studio editing which handle the very high quality and various type of images. There are some problems to dealing these massive data in studio editing. One of the most important procedure is re-encoding and decoding procedure during the editing. Various codecs are widely used for studio data editing. But most of the codecs have common problems to dealing the massive data in studio editing. First, the re-encoding and decoding processes are frequently occurred during the studio data editing and it brings enormous time-consuming and video quality loss. This paper, we suggest new video coding structure for the efficient studio video editing. The coding structure which is called "ultra-low delay (ULD)". It has the very simple and low-delayed referencing structure. To simplify the referencing structure, we can minimize the number of the frames which need decoding and re-encoding process. It also prevents the quality degradation caused by the frequent re-encoding. Various fast coding algorithms are also proposed for efficient editing such as tool-level optimization, multi-serve based distributed coding and SIMD (Single instruction, multiple data) based parallel processing. It can reduce the enormous computational complexity during the editing procedure. The proposed method shows 9500 times faster coding speed with negligible loss of quality. The proposed method also shows better coding gain compare to "intra only" structure. We can confirm that the proposed method can solve the existing problems of the studio video editing efficiently.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.10
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• pp.1354-1363
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• 2010

This study compared the effect of four different feeding methods for gestating gilts on reproductive performance and growth of their progeny. A total of 40 F1 primiparous sows (Yorkshire${\times}$Landrace) were allotted to four treatments in a completely randomized design (CRD). For treatments, gestating period of sows was divided into three trimesters (0-35 d, 36-90 d and 91-110 d) and different amounts of feed were provided to each treatment group by Flat, Down-Up-Down (DUD), Up-Down-Up (UDU) and Down-Up-Up (DUU) feeding methods. The experimental diet was formulated to meet or exceed the standards of NRC (1998). Body weight gain of gestating gilts from d 0 to 110 was affected by feeding method (p<0.05). When gilts were fed constant feed ration (Flat feeding), less body weight loss was observed during lactation (-0.9 kg, p<0.05) and desirable backfat thickness (average 19.5 mm) was acquired at 110 days of gestation. Feed intake of lactating sows tended to be greater (4.22, 3.60, 3.97 and 4.13 kg/d, p>0.05) as sows in Flat feeding treatment had lower backfat thickness during gestation compared with other treatments (p<0.05). When gestating gilts were fed higher amount of feed during mid-trimester, the number of stillborn (1.4 piglet per litter, p<0.05) and mummies (0.8 piglet per litter, p = 0.25) were increased compared to other treatments. Feeding methods for gestating gilts had no effect on litter weight and gain of litter weight during the nursing period. Flat feeding method resulted in decreased plasma glucose concentration at 7 d postpartum (p<0.05), and increased LH concentration at 21 d postpartum (p<0.01) compared to other treatments. These results suggested that higher feed intake of gestating gilts resulted in detrimental effects on body condition and reproductive performance of sows. When gestating gilts consumed constant feed during gestation (2 kg/d), better reproductive performance and less body weight loss in lactation were observed because sows consumed more feed during the whole lactation period. Consequently, Flat feeding will be a desirable feeding strategy for gestating gilts to maximize reproductive performance, and better body condition of sows without any negative influence on the growth of their progeny.

• The Journal of the Acoustical Society of Korea
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• v.23 no.4E
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• pp.125-133
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• 2004

In this paper, we propose a critical banded wavelet packet-based spectral subtraction for speech enhancement. Critical banded wavelet packet, which reflects the human auditory system, may lead to minimization of intelligibility loss and quality improvement of the enhanced speech in the spectral domain, when combined with an appropriate spectral subtraction gain function. The proposed method shows better performance than the conventional one in comparative assessments. We also show that, for effective evaluation of enhanced speech, it is essential to consider the characteristics of speech quality measures.

• Journal of the Korean Ceramic Society
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• v.22 no.6
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• pp.80-86
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• 1985

Aluminum nitride (AlN) was synthesized from aluminum (Al) powders as a starting material in the tempe-rature range of 450~1, 15$0^{\circ}C$ in the presence of 90% $N_2$-10%$H_2$ gases. The thermogravimentric analysis showed that the nitridation of Al powders started at about 43$0^{\circ}C$ and escalated greatly from 53$0^{\circ}C$. The scanning electron microcopic observation revealed that AlN crystals were different in shape with varying temperature of nitridation. The crystals of AlN which were formed in the lower temperature than the melting point of Al were spherical while those of AlN in the higher temperature were fibrous. The yield of AlN was determined quantitatively by both XRD method and weight gain between before and after the nitridation of Al compacts. It was considered that the former was available for the specimen which was made in the high nitriding temperature. But the latter was unavilable for the same one probably because of the volatile loss of Al in the higher temperature.

• Wind and Structures
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• v.19 no.6
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• pp.603-621
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• 2014

Past high speed wind events have exposed the vulnerability of the roof systems of existing light-framed wood structures to uplift loading, contributing greatly to economic and human loss. This paper further investigates the behaviour of light-framed wood structures under the uplift loading of a realistic pressure distribution. A three-dimensional finite-element model is first developed to capture the behaviour of a recently completed full-scale experiment. After describing the components used to develop the numerical model, a comparison between the numerical prediction and experimental results in terms of the deflected shape at the roof-to-wall connections is presented to gain confidence in the numerical model. The model is then used to analyze the behaviour of the truss system under realistic and equivalent uniform pressure distributions and to perform an assessment of the use of the tributary area method to calculate the withdrawal force acting on the roof-to-wall connections.

• Journal of Ocean Engineering and Technology
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• v.16 no.4
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• pp.61-69
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• 2002

In the actual control systems, there exist many kinds of restrictions or nonlinearities. However, due to the nonlinearities in actuators and sensors, the designed controller may not be applicable in some practical situations. One such nonlinearity is amplitude saturation in actuators. Although sometimes it may be ignored, in other cases failure to consider actuator saturation may severely degrade closed-loop system performance and even lead to instability. On the other hand, limiting the controller gain to avoid saturation sacrifices control effort and may lead to loss of performance. Consequently, in some cases, the actuator saturation must be explicitly taken into account to ensure desired performance. However, in this paper, an anti-windup control system design method is introduced to suppress the windup due to the amplitude saturation of the actuator. The proposed control system has very simple design process and guarantees the good control performance. The validity of the proposed control system will be shown by comparing with the results of a reported paper.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.241-245
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• 2002

Dual-band microstrip antenna is designed for industrial-scientific-medical(ISM) band of 2.4㎓ and 5.8㎓ using finite-difference time-domain method(FDTD). Cross Patch fed by aperture in the ground plane of microstrip line is proposed as radiation element of antenna, which is 2 rectangular Patch is overlapped. To design antenna, change of input impedance by aperture and stub length change is examined. And it is investigated that center frequency and -10 ㏈ bandwidth by Length of radiation element and width change. Experimental result about reflection Loss confirmed that agree well with analysis results of FDTD and IE3D, And -3 ㏈ beam width, front to back ratio and gain in frequency 2.43㎓ and 5.79㎓ is presented by measuring radiation Pattern of antenna.