• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.391-401
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• 2004

3D imaging systems using 2D phased arrays have a large number of active channels, compelling to use a very expensive and bulky beamforming hardware, and suffer from low volume rate because, in principle, at least one ultrasound transmit-receive event is necessary to construct each scanline. A high speed 3D imaging method using a cross array proposed previously to solve the above limitations can implement fast scanning and dynamic focusing in the lateral direction but suffer from low resolution except at the fixed transmit focusing along the elevational direction. To overcome these limitations, we propose a new real-time volumetric imaging method using a cross array based on the synthetic aperture technique. In the proposed method, ultrasound wave is transmitted successively using each elements of an 1D transmit array transducer, one at a time, which is placed along the elevational direction and for each firing, the returning pulse echoes are received using all elements of an 1D receive array transducer placed along the lateral direction. On receive, by employing the conventional dynamic focusing and synthetic aperture method along lateral and elevational directions, respectively, ultrasound waves can be focused effectively at all imaging points. In addition, in the proposed method, a volume of interest consisting of any required number of slice images, can be constructed with the same number of transmit-receive steps as the total number of transmit array elements. Computer simulation results show that the proposed method can provide the same and greatly improved resolutions in the lateral and elevational directions, respectively, compared with the 3D imaging method using a cross array based on the conventional fixed focusing. In the accompanying paper, we will also propose a new real-time 3D imaging method using a cross array for improving transmit power and elevational spatial resolution, which uses linear wave fronts on transmit.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.391-399
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• 2005

Laser-generated ultrasonic inspection system is a non-contact scanning inspection device with high spatial resolution and wide bandwidth. The amplitude of laser-generated ultrasound is varied according to the energy of pulse laser and the surface conditions of an object where the CW measuring laser beam is pointing. In this paper, we correct the generating errors by measuring the energy of pulse laser beam and correct the measuring errors by extracting the gain information of laser interferometer at each time. h dynamic stabilizer is developed to stably scan on the surface of an object for an laser-generated ultrasonic inspection system. The developed system generates ultrasound after adaptively finding the maximum gain time of an laser interferometer and processes the signal in real time after digitization with high speed. In this paper, we describe hardware configuration and control algorithm to build a stable laser-generated ultrasonic inspection system. Also, we confirmed through experiments that the proposed correction method for the generating errors and measuring errors is effective to improve the performance of a system.

• The KIPS Transactions:PartA
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• v.14A no.2
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• pp.77-84
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• 2007

The intima media thickness(IMT) of the carotid artery from B mode ultrasound images has recently been proposed as the most useful index of individual atherosclerosis and can be used to predict major cardiovascular events. Ultrasonic measurements of the IMT are conventionally obtained by manually tracing interfaces between tissue layers. The drawbacks of this method are the inter and intra observer variability and its inefficiency. In this paper, we present a multiresolution snake method combined with the dynamic programming, which overcomes the various noises and sensitivity to initialization of conventional snake. First, an image pyramid is constructed using the Gaussian pyramid that maintains global edge information with smoothing in the images, and then the boundaries are automatically detected in the lowest resolution level by minimizing a cost function based on dynamic programming. The cost function includes cost terms which are representing image features and geometrical continuity of the vessel interfaces. Since the detected boundaries are selected as initial contour of the snake for the next level, this automated approach solves the problem of the initialization. Moreover, the proposed snake improves the problem of converging th the local minima by defining the external energy based on multiple image features. In this paper, our method has been validated by computing the correlation between manual and automatic measurements. This automated detection method has obtained more accurate and reproducible results than conventional edge detection by considering multiple image features.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.2
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• pp.500-521
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• 2021

Echocardiography, an ultrasound scan of the heart, is regarded as the primary physiological test for heart disease diagnoses. How an echocardiogram is interpreted also relies intensively on the determination of the view. Some of such views are identified as standard views because of the presentation and ease of the evaluations of the major cardiac structures of them. However, finding valid cardiac views has traditionally been time-consuming, and a laborious process because medical imaging is interpreted manually by the specialist. Therefore, this study aims to speed up the diagnosis process and reduce diagnostic error by providing an automated identification of standard cardiac views based on deep learning technology. More importantly, based on a brand-new echocardiogram dataset of the Asian race, our research considers and assesses some new neural network architectures driven by action recognition in video. Finally, the research concludes and verifies that these methods aggregating dynamic information will receive a stronger classification effect.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2003.05a
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• pp.369-388
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• 2003

This research has been focused upon and analyzing Medison, once a leading New Technology-Based Firm (NTBF) in Korea with exceptionally advanced technology in 3D ultrasound diagnostic imaging devices (UDIDs) (armored with 23 subsidiaries at its peak expansion), from the perspective if Dynamic Firm Capability(DFC). The underlying hypothesis is that the various problems from its pointless pursuit of the business styles or precedents of the existing large firms might be traced to its specific characteristics as an NTBF, which should have more preferably been based upon the distinctive competences such as differentiated technologies, institutional linkages, organizational routines, and complementary assets, etc. In conclusion, for the NTBFs with different DFC domains from those of the large firms, the optimal external linkages and comprehensive integration efforts (Process) under their specific organizational characteristics and constraints (Path) are highly recommended for the continuous accumulation of their core capabilities based upon the technological assets (Position).

• The Journal of the Acoustical Society of Korea
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• v.17 no.6
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• pp.14-22
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• 1998

기존의 널리 사용되는 초음파 영상진단기에서는 수신집속은 모든 점에 대해 행하는 것이 가능하지만 송신접속은 미리 정해진 수 개의 점에 대해서만 행하는 한계가 있다. 본 논문에서는 영상화할 대상이 정지해 있거나 매우 느리게 움직이는 경우에 한하여, 송신음장 의 집속은 합성집속방법(synthetic focusing)을 사용하고, 수신집속은 동적 집속(dynamic receive focusing)을 이용함으로써 모든 영상점에서 송수신 집속하여 측방향 해상도를 향상 시키는 방법을 제안하였다. 컴퓨터 시뮬레이션 결과 초점깊이에서와 같은 해상도를 유지하 는 음장거리(fields of depth)가 기존의 방법에 비하여 월등히 우수하였으며, 3.5MHz의 선형 배열변환기를 이용하여 펜텀 영상에 대한 실험 결과도 모든 영상 깊이에서 측방향 해상도가 기존의 B-mode의 영상보다 우수하였다.

• Journal of Korea Technology Innovation Society
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• v.6 no.2
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• pp.228-252
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• 2003

This research has been focused upon and analyzing Medison, once a leading New Technology-Based Finn (N1BF) in Korea with exceptionally advanced technology in 3D ultrasound diagnostic imaging devices (UDIDs) (armored with 23 subsidiaries at its peak expansion), from the perspective of Dynamic Finn Capability(DFC). The underlying hypothesis is that the various problems from its pointless pursuit of the business styles or precedents of the existing large firms might be traced to its specific characteristics as an NTBF, which should have more preferably been based upon the distinctive competences such as differentiated technologies, institutional linkages, organizational routines, and complementary assets, etc. In conclusion, for the NTBFs with different DFC domains from those of the large firms, the optimal external linkages and comprehensive integration efforts (Process) under their specific organizational characteristics and constraints (path) are highly recommended for the continuous accumulation of their core capabilities based upon the technological assets (Position).

• 전기의세계
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• v.31 no.3
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• pp.204-208
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• 1982

The objective of this paper is to present a digital method for improving the lateral resolution of the B-scan images in the medical applications of ultrasound. The method is based upon a mathematical model of the lateral blurring caused by the finite beam width of the transducers. This model provides a simple method of applying a recursive scheme for image restoration with fast computation time. The point spread function (P.S.F.) can be measured by the reflective signals after scanning the small pins located along the depth of interest. From the measured P.S.F., one can compute the coefficient matrices of the inverse discrete-time dynamic state variable equation of the blurring process. Then, a recursive scheme for deblurring is applied to the recorded B-scan to improve the lateral resolution. One major advantage of the present recursive scheme over the transform method is in its applicability for the space-variant imaging, such as in the case of the rotational movement of transducer.

• Advances in nano research
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• v.13 no.3
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• pp.269-284
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• 2022

Nanomachines can be pretty helpful in curing diseases. Nanomototors, thanks to their self-propelled feature, are one of the best structures to be utilized as drug delivery devices. These devices have been employed in biomedical application as they can improve the efficiency of drug delivery. In this study stability of a designed nanomotor in the bloodstream is investigated when the physical activities have been done considering the physical activities. Sports training, as well as exercise enhance the bloodstream, and this factor can significantly impact the drug-delivery quality. The mathematical simulation of nanomotor movement in the condition of the sports is done based on the mechanical sciences, and the impact of various essential parameters is discussed in detail.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.8 no.1
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• pp.26-30
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• 2015

There are many traumatic foot and ankle problems in orthopaedic fields. Though it is not life-threatening problems, a delay in accurate diagnosis and treatments can danger limb function and therefore correct diagnosis can prevent long-term complications. Achilles tendon rupture is relatively common injury for active sports people. Ultrasonography is cost-effective, irradiation -free, effective for evaluation of soft tissues and dynamic analysis. It has been growing importance in Achilles tendon rupture. Ultrasonography is a diagnostic tool in Achilles tendon rupture. Physical examination and patient history is needed to diagnose Achilles tendon without image, but it is missed up by 20% in private clinic. Discontinuity of normal fibrillar architecture seen on an ultrasonographic image is diagnostic for Achilles tendon rupture, and can be accentuated by the performance of dorsi-flexion and plantar flexion, while observing in real time. And ultrasonography is a reliable method for serial observation after surgical treatment or conservative treatment.