• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.534-544
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• 2022

Medical ultrasound system has been widely used to visualize the lesion for diagnostics in most medical service site including hospitals and clinics thanks to its advantages such as real time operation, ease of use, safety. Among many signal processing blocks of the system, one of the most important part that governs the image quality is the beamformer, and technologies for this part has been continuously developed in long time. The synthetic aperture imaging method, that is one of the major technologies of beamforming, was introduced to maximize utilizing the information delivered from the patient's body through the probe, and contributed to breakthrough of the image quality since it was introduced in around 1990's, and evolved continuously in decades. This paper reviews and surveys the process of development of this technology and expects future evolution.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.551-563
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• 2012

Medical ultrasound systems have been used since 1950s, and are now widely used in most hospitals as indispensable diagnostic imaging systems. Since array probe was introduced in 1970s, beamforming technology using electronic signal processing has been adopted to the medical ultrasound system, and has been improved. Beamforming is a important technology which defines the resolution of the ultrasound system. In this paper, the technologies are introduced from basic beamforming principles to current trend. They include principles of beamforming using array probe, basic theory, and practical implementation, and recent topics of synthetic aperture imaging, adaptive beamforming, 2-dimensional beamforming using 2-dimensional array are also introduced. These various technologies will improve system performances continuously by merging innovatively with various technologies in other fields.

• The Korean Nurse
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• v.19 no.2 s.105
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• pp.75-78
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• 1980

• The Journal of the Acoustical Society of Korea
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• v.31 no.8
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• pp.580-589
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• 2012

In this paper, we studied on Doppler gap-filling algorithms suitable for a portable or low-cost medical ultrasound imaging system, and as a result, found out algorithms based on mirroring or autoregressive model. Moreover, controlling the computational demand in the proper range, we improved the performances of these algorithms by solving their problems. Effectiveness of these modified algorithms is verified by computer simulations and experiments which used artificially generated Doppler signals and Doppler data acquired from human body through an actual ultrasound system.

• Journal of Industrial Technology
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• v.25 no.A
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• pp.87-93
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• 2005

Three-dimensional ultrasonic probes being applied to the medical imaging can be grouped into three depending on the scanning methods, which are a mechanical type system, a free-hand system, and 2D phased arrays system. A mechanical type scanner uses a mechanically driven transducer to acquire series of 2D plane images. By integrating these images, a 3-D medical image can be constructed. A motor driving mechanism is a conventional choice for mechanically driving a transducer assembly which picks the raw ultrasonic images up. In this paper we attempt to design a 3D ultrasonic probe which has a operating mechanism of s tilting 3-D scanning. The motion of a transducer assembly of the ultrasonic probe is analytically modelled. We propose a selection procedure for the diameter of a wire rope driving the transducer assembly and the size of torsional spring which gives an initial tension to wire ropes.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.289-292
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• 1996

The 2-way beam simulation for the diagnostic ultrasound is performed with simplified computation by approximating the transducer and the system. The results show that the simulation program can be used as a good system design tool.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.77-82
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• 2000

This study was conducted to establish the methods of ultrasound-guided transvaginal retrieval of oocytes (ovum pick-up) in Korean native, Hanwoo Heifers. To obtain the basic data about Hanwoo, the size of ovaries in luteal and follicular phases were measured and the number of follicles in ovaries during the estrus cycle was counted by using ultrasound. And to determine the effective anesthetic to Hanwoo, various mixture of anesthetic compounds, Rompun(equation omitted), lidocaine, Monzal(equation omitted), and Domosedan(equation omitted), were treated. The size of Hanwoo ovaries were not significant differently between luteal and follicular phases. The number of medium and small follicles were peak on day 3 and 12 of the estrous cycle, and this result suggested that Hanwoo has 2 follicular growth waves per estrus cycle. The most effective anesthetic method was intramuscular injection of a.3m! Rompun(equation omitted), epidural injection of 5$m\ell$ lidocaine and sprayed cervix by 2$m\ell$ lidocaine.

• Journal of Veterinary Clinics
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• v.21 no.3
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• pp.298-301
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• 2004

Pregnancy diagnosis by ultrasonography was performed for both pregnant and non-pregnant Asiatic black bears which were being under hibernation. Pregnancy was diagnosed for a pregnant bear by detecting images of heart-beat and vertebrae on ultrasonograph. Serum progesterone levels were measured for both pregnant and non-pregnant bears. The level of serum progesterone was 5.79 ng/ml for a pregnant bear and 0.76 ng/ml for a non-pregnant bear, respectively, thereby it was considered that measurement of serum progesterone level can be also useful for pregnancy diagnosis for Asiatic black bear.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1095-1100
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• 2005

For the establishment of prediction strategies of carcass meat quality grade and for the enhancement of prediction accuracy, sixty six Hanwoo steers were ultrasonically tested at 24 months of age. Ultrasonic meat quality grade were predicted by standard ultrasonic image and decision tree method using ultrasonic meat quality index. From the results of decision tree method using ultrasonic meat quality index, it was found that the marbling score was mainly influenced by the distinctness of rib on ultrasound image. Prediction accuracy of meat quality grade by ultrasonic meat quality index was 86.4%, resulting in 7.6% higher accuracy than that by standard ultrasonic image (78.8%).

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.34-34
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• 2001

본 연구의 목적은 한우 난포발달에 있어서 난포액 및 anti-inhibin serum의 생리적 역할을 검토하기 위해 수행하였다. Anti-inhibin serum(AI)은 항원으로서 porcine inhibin-$\alpha$-subunit 19~32의 peptide를 사용하여 adjuvant 용액을 1:3의 비율로 혼합하여 앙고라종 토끼 5두(체중 2.5kg)에게 주 2회 간격으로 접종 후 얻어진 항혈청을 사용하였다. 난포액(bFF; bovine follicular fluid)은 도축장에서 도축되는 한우 난소로부터 직경 1.0cm 이하의 난포로부터 회수하여 스테로이드를 제거하기 위해 10% chacoal so lution(50 mg/$m\ell$, Norrit-A, Fisher Sci., USA)을 처리하여 45분간 배양후 원심분리후 상층액을 회수하여 실험에 공시하였다. 공시동물은 1산후 정상적으로 발정주기가 반복되는 한우암소 9두를 난소감정후 황체를 확인하여 PGF2$\alpha$제제(lutylase. USA)를 주사하여 발정을 유기한 다음, 난소의 first wave가 시작되는 시기인 배란직후 12시간째부터 4일간 일일 2회 5 $m\ell$씩 총 8회 40 $m\ell$의 AI와 bFF를 각각 경정맥으로 주사하였으며 대조구로서 생리식염수를 주사하였으며 채혈 및 정맥주사를 용이하게 하기 위해 경정맥에 카테타를 설치하여 6시간간격으로 총 200시간까지 채혈하였으며 초음파진단기를 이용하여 난포의 발달을 검토하였다. 채혈후 혈중Inhibin, progesterone 및 Estrad iol-17$\beta$농도의 분석은 RIA 및 ELISA법으로 분석하여 얻어진 결과는 다음과 같다. 혈중 Progesterone농도는 대조구와 AI처리구에서는 배란후 68시간째부터 유의적으로 증가하기 시작하였으나, bFF처리구에서는 배란후 68시간부터 170시간까지 대조구에 비해 유의적으로 낮은 농도를 나타내었다. 이에 반해 혈중 Estradiol-17$\beta$농도는 대조구의 경우 bFF처리구와 비슷한 수준으로 배란후부터 낮은 농도를 유지하였으나, AI 처리구는 배란후 36시간이후부터 108시간까지 유의적으로 높은 수준을 유지하였다가 그 이후 감소되었다. 한편, 혈중 Inhibin농도는 전 구간에서 배란후 84시간까지 불규칙한 농도를 보이다가 bFF처리구에서는 배란후 84시간부터 유의적으로 증가하였다. 배란후 72시간째에 초음파진단기를 이용하여 난소의 난포발달을 조사한 결과 , 대조구와 bFF처리구에 비해 AI처리구에서 발달난포가 유의적으로 많은 것을 확인하였다. 이상과 같은 결과로, Anti-inhibin serum은 한우 자체에서 분비하는 Inhibin을 특이하게 억제하여 Inhibin에 의해 억제되는 FSH분비가 촉진됨으로써 난포발달과 estrogen의 농도가 촉진되는 것으로 사료되어 anti-inhibin serum이 한우의 과배란유기 효과가 있는 것으로 사료된다.