• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 ITC-CSCC -2
• /
• pp.807-810
• /
• 2000

In this paper, a new hierarchical motion estimation (ME) scheme using the wavelet transformed multi-resolution image layers is proposed. While the coarse-to-fine (CtF) ME, used in previously proposed coding schemes, can provide a better estimate at the coarsest resolution, it is difficult to accurately track motion at finer resolution. On the other hand, in fine-to-coarse (FtC) ME, it can solves this local minima problem by estimating motion track at the finest subband and propagating the motion vector (MV) to coarser subband. But this method causes to higher computational overhead. This paper proposes a new method for reducing the computational overhead of fine-to-coarse rnulti-resolution motion estimation (MRME) at the finest resolution level by searching for the region to consider motion vectors of the coarsest resolution subband.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2004년도 추계학술대회 논문집
• /
• pp.57-57
• /
• 2004

• 한국정밀공학회지
• /
• 제23권1호
• /
• pp.201-208
• /
• 2006

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step-by-step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes an adaptive control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2005년도 춘계학술대회 논문집
• /
• pp.446-452
• /
• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes a voltage control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 추계학술대회 논문집
• /
• pp.543-550
• /
• 2005

Recently, there are many studies for the micro-machining using Piezo actuator. However, because of its step by step motion, it is nearly impossible to increase the machining accuracy for a circular path. To increase the accuracy, it is well known that it is necessary the finer and synchronous movement for x-y axes. Therefore, this paper proposes an adaptive control for finer movement of the actuator, and realizes a synchronous control for the x-y axes. The experimental results show that the machining accuracy is remarkably improved.

• 한국분무공학회지
• /
• 제3권4호
• /
• pp.58-64
• /
• 1998

In the gasoline engine of fuel injection type, atomization of fuel droplet and its distribution has directly influenced the performance of engine and harmful emission. To investigate atomization characteristics of fuel spray, in this paper fuel spray of air-assisted injector is observed at the various initial conditions of ambient air temperature and air assisted pressure. Behavior of fuel spray is photographed with microscopic visualization system. The SMD of fuel droplet is measured with PMAS (Particle Motion Analysis System). The effect of air-assisted pressure and temperature of ambient air resulted in the decrement of SMD and its variation. Finally, It was found that It was found that from spray angle at the two-hole injector had measured $20{\pm}4$ degree the result of photographs by shadow graphy. The mean diameter of suns decreased and the of droplets increased with increasing the temperature in the spray fields by the results of PMAS measurement. It was found that the characteristics of sprays became finer by increasing the temperature of spray fields about 373K without the delivery of air-assistance.

• 대한전자공학회논문지
• /
• 제17권3호
• /
• pp.26-35
• /
• 1980

모든 디지탈 영상계에서 검출기는 일정한 크기를 가지며, 이에 의해 영상은 흐려지고 공간분해능은 저하된다. 이제까지는 검출기 크기를 줄임으로써, 즉 검출기 수효를 증가시킴으로써 이 문제를 해결해 왔다. 본논문에서는 광학에서 사용한 방법에 의한 공간분해능 향상을 공간 및 주파수 대역에서 시도하였다. 또한 이 방법을 CT(전산화 단층 영상 처리기)에 응용하였으며 검출기 수효를 증가하지 않고서도 공간분해능이 매우 향상됨을 알 수 있었다. 이 방법에 대한 전본이론 및 simulation결과를 정리하였다.

• Archives of Reconstructive Microsurgery
• /
• 제10권2호
• /
• pp.99-104
• /
• 2001

Purpose : Loss of sensibility over the finger tip resents a grave deficit and is an indication for sensible soft tissue reconstruction. This paper was performed to assess the long term results obtained by nerovascular island flap. Material and Methods : We performed neurovascular island graft for defective sensibility of finger tip loss in 94 cases since 1979 to 2000. The recipient sites were the thumb pulp defect in 79 cases, the amputated thumb in 9 cases, the amputated index in 4 cases, and the velar aspect of interphalangeal joint of thumb in 2 cases. The donor flaps were obtained from the radial side of ring finger in 63 cases, the ulnar side of the ring finger in 21 cases, and the ulnar side of the middle finger in 10 cases. A mean follow-up period was 5.7 years. Results : The flap quality was well vascularized and survived in 89 cases. The two-point discrimination was average 8.7mm. Because of scar contracture, the range of motion of the donor finger was decreased 3.5% of the normal finger in the distal interphalangeal joint, 8,2% in the proximal interphalangeal joint. A phenomenon of double sensibility occurred in 66 cases. Conclusion : This technique was excellent both aesthetically and functionally as a reconstruction of the Loss of fingertip.

• 방사선산업학회지
• /
• 제17권4호
• /
• pp.385-390
• /
• 2023

The uterus, one of women's reproductive organs, is also closely related to women's health. Among them, hemorrhagic luteal cysts, one of the causes of pelvic pain that women often experience, were observed through CT and ultrasound, and the quality of images was evaluated through quantitative and qualitative evaluations. This study sought to find out whether the test method is more helpful to patients during CT and ultrasound. This study was conducted on 15 adolescent women and 15 adult women(21.31±3.45 average age). The equipment used for filming used EC3-10X (3~10 MHZ) and Philips Mx8000 iCT 256 among Endocavity Probes among Ecube Platinum. After setting a constant ROI on the cyst and the interface as a quantitative analysis method, SNR and CNR values were measured on a 5-point scale based on image quality, lesion clarity, image distortion, clarity of the interface, and motion artifacts (p<0.05). Independent t-test and Mann Whiteny U were performed, and the statistical program used was noted when SPSS (Version 22.0 for windows software package, Chicago, IL, USA) was statistically less than 0.05. Comparing the SNR and CNR values for this experiment, it can be seen that the SNR value was higher in the case of CT images(p<0.05). As a result of the qualitative evaluation, the quality of the image, the clarity of the lesion, the distortion of the image, the clarity of the interface, and the clarity of the boundary were measured on a 5-point scale based on the movement artifact. Comparing each score, CT images scored higher with a finer difference than ultrasound images(p<0.05). In conclusion, both test methods showed excellent results in finding the patient's lesions. However, in quantitative and qualitative evaluations, CT produced higher results in detecting lesions than ultrasound. However, for cyst tests that require continuous observation, ultrasonography, a non-invasive method that is advantageous for patients, will be clinically useful. Therefore, observing the patient's lesions by appropriately distributing these two test methods will provide optimal diagnostic information. These results will be useful for providing clinical basic data and educational materials to CT and US users in the future.

• 한국지역지리학회지
• /
• 제4권2호
• /
• pp.49-64
• /
• 1998

연구지역에서 발달하는 테일러스들은 테일러스의 일반적인 특성을 잘 반영하고 있다. 우리나라에 분포하는 테일러스가 보통 rock fall talus이듯이 본 연구지역의 테일러스도 동일한 유형으로 판단된다. 또 테일러스의 사면형태, 형성시기 발달과정, 미지형적 특성 등은 지금까지 발표된 여러 연구결과들과 거의 일치하고 있다. 그러나 인접한 테일러스간의 경계 부분에서는 암설입경의 상대적 크기에 따라 약간의 지형적 차이점을 인식할 수 있었다. 특히 본 연구에서는 테일러스 암설 최적층의 내부구조를 국내 처음으로 확인하여 3가지의 뚜렷한 층위를 구분할 수 있었다. 즉, 암설로만 구성된 표층과 암실과 세립물질(실트질 모래)이 혼재된 중간층 그리고 과거의 토양층인 기저층 등으로 구분된다. 또 암설 퇴적층에 대한 내부구조 인식은 테일러스 형성 당시로 부터 현재까지의 기후환경과 암설의 퇴적양상을 밝히는데 매우 중요하며 앞으로 이 분야의 연구에 큰 도움을 줄 것으로 생각된다. 한편 국지적으로 특수기상이 나타나는 빙혈이 있는 빙계계곡의 경우 그것의 형성에는 단층작용의 역할이 중요한 것으로 판단된다. 그러나 이 곳을 흐르는 쌍계천이 유독 빙계계곡에서만 협곡(빙계계곡의 폭은 주변 곡쪽의 $1/8{\sim}1/10$정도임)을 형성하는 이유에 대해서 정곡의 가능성을 제시했지만 입증할 만한 자료가 없는 것이 유감이다.