• Wind and Structures
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• v.34 no.2
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• pp.231-257
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• 2022

Transmission lines systems are important components of the electrical power infrastructure. However, these systems are vulnerable to damage from high wind events such as hurricanes. This study presents the results from a 1:50 scale aeroelastic model of a multi-span transmission lines system subjected to simulated hurricane winds. The transmission lines system considered in this study consists of three lattice towers, four spans of conductors and two end-frames. The aeroelastic tests were conducted at the NSF NHERI Wall of Wind Experimental Facility (WOW EF) at the Florida International University (FIU). A horizontal distortion scaling technique was used in order to fit the entire model on the WOW turntable. The system was tested at various wind speeds ranging from 35 m/s to 78 m/s (equivalent full-scale speeds) for varying wind directions. A system identification (SID) technique was used to evaluate experimental-based along-wind aerodynamic damping coefficients and compare with their theoretical counterparts. Comparisons were done for two aeroelastic models: (i) a self-supported lattice tower, and (ii) a multi-span transmission lines system. A buffeting analysis was conducted to estimate the response of the conductors and compare it to measured experimental values. The responses of the single lattice tower and the multi-span transmission lines system were compared. The coupling effects seem to drastically change the aerodynamic damping of the system, compared to the single lattice tower case. The estimation of the drag forces on the conductors are in good agreement with their experimental counterparts. The incorporation of the change in turbulence intensity along the height of the towers appears to better estimate the response of the transmission tower, in comparison with previous methods which assumed constant turbulence intensity. Dynamic amplification factors and gust effect factors were computed, and comparisons were made with code specific values. The resonance contribution is shown to reach a maximum of 18% and 30% of the peak response of the stand-alone tower and entire system, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.375-382
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• 2003

This study, Using Pusan clay, examined a relationship between Dynamic and Static Liquid Tests. The Static Liquid Tests wow carried out based on BS and JIS. The results of the study are summarized as follows. (1) The result of the Dynamic Liquid Limit Test showed that the liquid limit values of air-dried soil were greater than those of oven-dried soil by 4%~15% (2) The liquid limit value of the Static Liquid Limit Test was greater than that of the Dynamic Liquid Limit Test by 2%~9%. The following equations show the relationship between the two values WL,Fall(JIS) = 0.961ㆍWL,Cas. + 4.209 WL,Fall(BS) = 0.969ㆍWL,Cas + 5.024 (3) The liquid limit value of BS was greater than that of JIS by 1%~6%. The following equation shows the relationship between the two values.

• Wind and Structures
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• v.20 no.6
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• pp.793-810
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• 2015

Tests were conducted at the Florida International University (FIU) Wall of Wind (WOW) to investigate the susceptibility of Variable Message Signs (VMS) to wind induced vibrations due to vortex shedding and galloping instability. Large scale VMS models were tested in turbulence representative of the high frequency end of the spectrum in a simulated suburban atmospheric boundary layer. Data was measured for the $0^{\circ}$ and $45^{\circ}$ horizontal wind approach directions and vertical attack angles ranging from $-4.5^{\circ}$ to $+4.5^{\circ}$. Analysis of the power spectrum of the fluctuating lift indicated that vertical vortex oscillations could be significant for VMS with a large depth ratio attached to a structure with a low natural frequency. Analysis of the galloping test data indicated that VMS with large depth ratios, greater than about 0.5, and low natural frequency could also be subject to galloping instability.

• Journal of the Korean Home Economics Association
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• v.39 no.7
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• pp.145-163
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• 2001

The purpose of this study was to evaluate counseling services in consumer counseling sites. We analyzed the contents and services of consumer counseling from the following internet sites; http : //www . gcn. or. kr , http : //www. jubuclub. or. kr, http : //www. cacpk. erg, http : //www . tor. co. kr/~ consumer, http : //civ. miriman. co. kr, http ://my. netian .com/~rokmc9. The major findings were summarized as follows: (1) All sites provided both a lot of information on consumer affairs and services for consumer counseling. (2) Two out of six private consumer counseling sites were technically inappropriated. They are wow.gen.or.kr and cia.miriman.co.kr (3) Consumer counseling services with specialized information and laws on consumer affairs were more likely provided from sites of consumer organizations than personal sites. (4) Personal sites made more consumer friendly communication than organization sites.

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.124-132
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• 2005

Cardiac PET emerged as a powerful tool that allowed in vivo quantification of physiologic processes including myocardial perfusion and metabolism, as well as neuronal and receptor function for more than 25 years. Wow PET imaging has been playing an important role in the clinical evaluation of patients with known or suspected ischemic heart disease. This important clinical role is expected to grow with the availability of PET/CT scanner that allow a true integration of structure and function. The objective of this review is to provide an update on the current and future role of PET in clinical cardiology with a special eye on the great opportunities now offered by PET/CT.

• Korean Journal of Veterinary Service
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• v.30 no.2
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• pp.211-218
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• 2007

In order to evaluation of prevalence of rotavirus and/or coronavirus, forty suckling Korean indigenous calves (between 2 and 98 days old) with acute diarrhea were investigated by the immunochromatographic rapid test in the field (veterinary practice) on October and on December 2006. Rotavirus and coronavirus were detected in 13 (32.5%) and 8 (20.0%) of the fecal samples from diarrheal calves, respectively. The highest mortality rate in diarrheal calves occurred in the neonatal period from 2 to 7 days old. Totally, 40.0% of diarrheal calves showing acute enteritis were not detected with rotavirus and/or coronavirus. The rotavirus infection rate was significantly difference (p<0.05) between October and December, and the detection rate of rotavirus was bigger than that of coronavirus. These results suggested that rotavirus can be frequently associated with acute diarrhea of suckling calves and affected with changes of temperature.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.11
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• pp.1153-1162
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• 1990

The torque ripple reduction method is studied to improve the speed fluctuation of permanent magnet flat type brushless DC motors. To reduce the torque ripple, this study developed the compensation method of the 5'th harmonics component of air gap flux waveform which pass through the driving coils. 1/2 inch VTR was considered. As the result of this study, we can reduce the torque ripple and the speed fluctuation of the capstan motor about 20% then before and we can obtain not only better characteristics of wow/flutter but more useful capstan motors which can be applied in the multi-function VTRs.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.150-153
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• 2007

The aim of this study was to investigate the prevalence of bovine viral diarrhea virus (BVDV) infection in Chonbuk province. Blood samples were taken from 92 korean calves to determined their serological status against BVDV, Capture enzyme-linked immunosorbent assay (ELISA) was used to test for antigen. The number of seropositive calves ranged from 3.3% to 12.9%. Antigens against BVDV were detected in 3.3% of healthy calves, 6.4% of digestive symptom calves, 12.9% of respiratory symptom calves, respectively. Sex and age of calves had no significant differences on the prevalence of BVDV. The results indicate that transmission of BVDV may have become exposed as a result of contact with acute infected or persistently infected cattle.

• Journal of Veterinary Clinics
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• v.24 no.2
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• pp.169-171
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• 2007

The aim of this study was to detect bovine viral diarrhea virus (BVDV) from calves in Chonbuk province. Blood samples were taken from ninety-two dairy calves. Capture enzyme-linked immunosorbent assay (ELISA) was used to detect BVDV. BVDV were detected in eight out of ninety-two (8.6%) dairy calves. BVDV were detected in one of twenty five of female calves and one of twenty three of male calves of 4 months old, whereas in the 5 months age group, BVDV were detected in low of twenty three of female calves and two of twenty one of male calves. There were no significant differences (p>0.05) in the detection rate of BVDV on the basis of sex. On the other hand, ages of calves had significant differences (p<0.05) on the prevalence of BVDV.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.249-251
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• 2019

본 논문에서는 CNN 기반 스테그아날리스 방법을 이용하여 입력 영상에 비밀 메시지가 삽입되었는지를 판별하고, 비밀 메시지가 삽입되었을 경우 WOW 와 UNIWARD 방법 중에 어떤 방법으로 삽입되었는지를 분류하고자 한다. 이를 위해 입력 영상으로부터 특징 정보를 추출하기 위해 사용되는 전처리(prepropcessing) 필터의 수가 분류 성능에 미치는 영향에 대해 분석한다. SRM 필터를 사용한 실험에서 필터의 수를 단순히 증가시키는 것은 성능 향상이 도움이 되지 않으며, 효과적인 필터를 선별해서 사용하는 것이 보다 우수한 성능을 가짐을 확인하였다.