• Journal of Biomedical Engineering Research
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• v.14 no.1
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• pp.89-96
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• 1993

During high frequency ventilation (HFV), mean alveolar pressure has been measured to increase with mean airway opening pressure controlled at a constant level in both humans and experimental animals. Since this phenomenon could potentiate barotrauma limiting advantages of HFV, the present study theoretically predicted the difference between menu alveolar and airway opening pressures ($MP_{alv}$). In a Weibel's trumpet airway model, approximated formula for $MP_{alv}$ was derived based on momentum conservation assuming a uniform velocity profile. The prediction, equation was a func pion of gas density($\rho$), mean flow rate(Q), and diameter of the airway opening where the pressure measurement was made($D_0$) : $MP_{alv}=4{\rho}(Q/D_0^{2})^2$. This was a result of the difference in crosssectional area between the alveoli and the airway opening. A simple aireway model experiment was performed and the results well fitted to the prediction, which demonstrated the validity of the present analysis. Previously reported $MP_{alv}$ data from anesthetized dogs in supine position were comparable to the predicted values, indicating that the observed dissociation between mean alveolar and airway opening pressures during HFV can be explained by this innate geometric (or cross-sectional area) asymmetry of the airways. In lateral position, however, the prediction substantially underestimated the measurements suggesting involvement of other important physiological mechanisms.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.630-636
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• 2013

Recently, there has been a growing body of evidence showing that cellular microRNAs (miRNAs) are involved in virus-host interactions. Numerous studies have focused on analyses of the expression profiles of cellular miRNAs, but the expression patterns of Dicer, which is responsible for the generation of miRNAs, have only rarely been explored in Gallus gallus. We developed a duplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay for the relative quantification of the mRNAs of Dicer and ${\beta}$-actin in G. gallus. To apply this method, the expression of Dicer in avian cells after infection with avian leukosis virus subgroup J (ALV-J) was detected using our established duplex real-time RT-PCR. The duplex real-time RT-PCR assay is sufficiently sensitive, specific, accurate, reproducible, and cost-effective for the detection of Dicer in G. gallus. Furthermore, this study, for the first time, demonstrated that ALV-J can induce differential expression of Dicer mRNA in the ALV-J-infected cells.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1398-1400
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• 1996

In this paper, a method of the decision of the road direction for ALV(Autonomous Land Vehicle) road following by region-based segmentation is presented. The decision of the road direction requires extracting road regions from images in real-time to guide the navigation of ALV on the roadway. Two thresholds to discriminate between road and non-road region in the image are easily decided, using knowledge of problem region and polygonal approximation that searches multiple peaks and valleys in histogram of a road image. The most likely road region of the binary image is selected from original image by these steps. The location of a vanishing point to indicate the direction of the road can be obtained applying it to X-Y profile of the binary road region again. It can successfully steer a ALV along a road reliably, even in the presence of fluctuation of illumination condition, bad road surface condition such as hidden boundaries, shadows, road patches, dirt and water stains, and unusual road condition. Pyramid structure also saves time in processing road images and a real-time image processing for achieving navigation of ALV is implemented. The efficacy of this approach is demonstrated using several real-world road images.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.508-510
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• 2004

In this paper, we proposed the GPS position data correction method for autonomous land navigation using vanishing point property and a monocular vision system. Simulations are carried out over driving distances of approximately 60 km on the basis of realistic road data. In straight road, the proposed method reduces GPS position error to minimum more than 63% and positioning errors within less than 0.5m are observed. However, the average accuracy of the method is not presented. because it is difficult to estimate it in curve road or other road environments.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.187-193
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• 2004

In this paper, we proposed the GPS position data correction method for autonomous land navigation using vanishing point property and a monocular vision system. Simulations are carried out over driving distances of approximately 60 km on the basis of realistic road data. On a straight road, the proposed method reduces GPS position error by at least 63% within 0.5 m. However, the average accuracy of the method is not presented, because it is difficult to estimate it on other than a straight road in variable conditions.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.596-601
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• 2011

Autonomous navigating algorithms for mobile robots have been proved to be a difficult task. Based on the excellent homing performance shown by many insects, bio-inspired navigation algorithms for robotic experiments have been widely researched and applied to the design of navigational strategies for mobile robots. In this paper, among them, we analyze two simple landmark navigation methods their strengths and limits. We investigate the effect of the occlusion problem mainly, which is an important yet tough problem in many landmark navigation algorithms. In the point of view of the error of homing vector and the performance of the homing paths in the environment with artificial occlusions, we investigate the effect of occlusion problem in both methods in order to further study on solutions.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.11a
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• pp.165-168
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• 2015

최근 디지털 콘텐츠 및 멀티미디어는 거의 모든 IT 산업에서 중요한 역할을 하고 있으며, 이중에서도 비디오 콘텐츠는 그 동안의 검색, 유통, 관리 등의 수동적인 범위를 넘어 실세계와의 실시간 상호작용을 통한 능동적이며 혁신적인 역할을 수행하고 있다. 실시간 비디오 검색 기술은, 다양한 분야에서 활용이 가능한데, 대표적인 서비스 분야는 ALV(Autonomous Land Vehicle : 무인자동차), SNS 서비스, 오락/스포츠/광고 서비스, 모바일 쇼핑, AR, Surveillance 분야 등 매우 다양하다. 본 논문에서는, 실시간 비디오 검색 기술의 개요와 적용분야 및 사례를 설명하고 실시간 비디오 검색기술을 객관적으로 평가할 수 있는 방법, 절차에 대한 인증서에 대한 규격을 제정하여, 사용자가 표준화된 실시간 비디오 검색 기술의 인증서의 내용을 토대로 자신의 목적에 따라 기술을 선택하여 사용할 수 있도록 하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.06a
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• pp.83-85
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• 2013

무인 자가 운반 차량은 컨테이너 터미널 내 선박과 장치장 사이를 오가며 컨테이너를 운반하는 무인 장비로 컨테이너를 집고 내리는 하역 능력을 갖고 있다. 터미널에서 컨테이너의 처리량을 극대화하기 위해서는 컨테이너 운송 시간을 최소화하여야 하는데, 이를 위해서는 차량의 효율적인 주행 경로 설정이 필요하다. 최적의 주행경로를 설정하기 위한 방법으로 A*, ant colony optimization과 같은 탐색알고리즘을 이용해서 주행경로를 찾는 방안이 연구된바 있다. 하지만 교통 상황에 따라 최적의 주행 경로는 바뀌게 되는데 기존의 연구에서는 결정된 주행 경로에 대한 수정이 없기 때문에 이러한 변화를 반영하지 못하는 문제가 있었다. 이에 본 논문에서는 주행 중인 차량이 다른 차량의 간섭에 의하여 대기하는 경우 대기 시간을 이용하여 새로운 주행 경로를 탐색 하여 현재 교통 상황에 맞는 최적의 경로를 찾는 방안을 제안하였으며 실험을 통해 기존 방안보다 더 효율적임을 확인하였다.

• Korean Journal of Poultry Science
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• v.26 no.2
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• pp.119-129
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• 1999

In recent years, numerous researches have been carried out in author's laboratory to develop several kinds of methods for producing transgened chicken, leaving a lot of new findings. Some of them are very useful to search for new approaches necessary to improve the efficiency of hatchability and the survival rate of developing trasgened embryos. The results obtained hitherto might be summarized as follows: (1) foreign gene(Lac Z/ Miw Z) introduced into blastodermal cells of developing embryos was successfully transferred to embryos, leading to the production of primordial germ cells(PGCs) carrying foreign DNA. However, hatched hickens failed to show the incorporation of introduced gene into the gonads. (2) When foreign gene was introduced into germinal crescent region (GCR), the gene was also efficiently incorporated into germ cells, resulting in the production of transgened chickens(offspring) which produced fruther offspring having foreign gene in the gonads. In this case, 2nd and 3rd generations of chickens were obtained through the reproduction of transgened birds. (3) In another way, the gene was injected into blood vessels of developing embryos at stage 13∼15, creating PGCs having foreign gene, and produced some transgened chickens. In this work, the PGCs were transfered between embryos, resulting in the production of transgenic chickens. (4) in these experiments, PGCs were effectively employed for producing transgenic birds, developing some kinds of chimeric chickens from homo- or hetero-sexual transfer of the PGCs from embryos. This means that the gonads from donor PGCs developed in some degree to the stage of hatching. However, these gonads showed slightly abnormal tissues similar to ovotestis like organs through histological examination. (5) Avian Leukosis Virus(ALV) induced B cell line(DT40) successfully carried foreign genes into chicken embryos, suggesting the possibility of the cells as a vector in this field of study in the future. (6) Inter-embryonic transfer of the PGCs also gave us some.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.2 s.4
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• pp.81-88
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• 1994

The CNS(Car Navigation System) is used more generally in driver aid system than ALV(Auto nomous Land Vehicle) research area. In this paper we developed a new position tracking algorithm for the Global Path Planning in the CNS. In japan, CNS is already well developed and, thesedays they sell CNS products about $400{\sim}500$ thousands per year, and USA and European Communications(EC), too. In Korea, studies of the first generation CNS, which finds current location of a navigating vehicle and displays its location in a Digital-Map with real-time are progressing but still in the beginning step. Therefore a new position tracking algorithm is presented, which reduces vehicle position error dramatically by fusing GPS and dead-reckoning sensors. And the validity of our algorithm is demonstrated by the experimental results with the real car.