• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.637-637
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• 1997

In this paper, format conversion filters are proposed, which have advantages in hardware implementation compared to the ones proposed in MPEG-4 Video Verification Model. since each coefficients of the proposed filters is constrained to have less than two non-zero digits in minimal signed digit representation, multiplication of input and the coefficient can be implemented by a single adder. As a result, the proposed filters have advantages in hardware complexity and speed, compared to the filters which are usually implemented by integer multiplier or carry save adders. Six kinds of filters are proposed in MPEG-4 Video Verification Model for size conversion of 2:1, 4:1, 5:3 and 5:6. We design 5 filters for the same purpose and compare the performance. The remaining one is very simple to implement. For comparing the filtering performance, we first compare the results of sine wave frequency conversion as an indirect but meaningful comparison. Second. We compute the PSNR of the images obtained from the proposed filters and the ones proposed by MPEG, with reference to the images obtained by using double precision arithmetic and high order filter. The results show that the performance of the proposed filters is almost the same as that of the filters proposed by MPEG. In conclusion, the peroformance of the proposed filters is comparable to that of the ones in MPEG-4, while requiring lower hardware complexity and providing high operating speed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.6
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• pp.889-894
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• 1993

Asychronous Transfer Mode (ATM) provides the means to transport different types of bursty traffic such as voice, video, and bulk data. To handle more efficiently the traffic sources and to increase the bandwidth utilization as much as possible, flexible statistical multiplexing schemes must be adopted for the ATM networks. This paper presents an efficient computational procedure to calculate the queue state distribution in a finite buffer queueing system with a number of independent input sources, and the cell loss probability is exactly calculated with the use of this recursion computation method. The cell loss probability is related to a ATM multiplexer with a homogeneous ON-OFF source is also investigated through numerical examples.

• The Journal of Engineering Geology
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• v.4 no.1
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• pp.1-12
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• 1994

In general there are many cracks in rocks. In this study, we are concerned with the mechanical effect on cracks on the behavior of rocks. For this purpose, we used spedmens rnade of mortar having one crack set which has a constant length and same direction. Orientafion of this set was varied with respect to the loading axis. We did a number of uniaxial experiments and observed propagafion of the crack set to understand the effect set of the geometry of the crack set and its location on the mechanical behavior of the rocks with distributed crack sets. Finally, we analysed our experiments by FEM elastic analyses and Homogenization theory.

• Journal of the Korean Society for Library and Information Science
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• v.15
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• pp.7-44
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• 1988

The purpose of this paper is to in vestigate a relative effectiveness of instruction among such three orienting methods as lecture, slide-tape and video-tape which the library of Duk Sung Women's University has applied for orienting the freshmen for the last three years. This research also carried out a sample survey by distributing uniform questinnaire to the three different groups of the students. Each group was oriented with lecture, slide-tape and Video-tape respectively. Finally, the empirical findings of this research are as follows: 1. All three orienting methods were useful for students to improve knowledge as to how to use the library, 2. There were a wide difference in effectiveness among three instructional methods, obviously, the slide-tape method was more effective in the orientation than the lecture method and, furthermore, the video-tape was more effective than the slide-tape one, Therefore, it seem safe to conclude that the media utilization effective in orientation program should be encouraged by the university libraries of Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.5
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• pp.999-1011
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• 1994

Driving maneuvers in car-following are affected not only by the factors related to road and traffic conditions, but also by factors related to drivers' cognition to them. This paper attempts to analyse drivers' car-following distance tests on road characteristics. Driving maneuvers are directly observed by video recorder sets in the vehicle. At the same time drivers are interviewed about their cognitive degree of car-following distance according to a given level of cognitive language. As a result, linguistical cognition of car-following distance is well fitted in with Weber-Fechner's law. This paper suggests a modeling method that takes into account the driver's cognition for acquiring traffic visible information on driving maneuver.

• Journal of the Korean Society for Library and Information Science
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• v.17
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• pp.85-103
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• 1989

The purpose of this second one of the two consecutive papers, which carried out for the research, is to evaluate their relative effectiveness regarding instruction with such three presentation methods as video/print+ lecture, print/video, print+lecture/video, with which the library of Duk Sung Women's University applied already for the orientation of the freshmen in 1988. In sum, the major research findings are as follows : First, as the more numerous media were applied for the orientation, the instruction were more effective. Second, it is very interesting to find out that there were wide differences in effectiveness among the three presentation methods applied for the student. Especially, the print+ lecture/video method was more effective in the instruction than the print/video method. Surprisingly, the video/print + lecture method was much more effective than the print+ lecture/video method. With the research findings of this two consecutive papers into consideration, it seems safe to say that the video-tape method was most effective among such three orienting methods as lecture, slide-tape, and video tape, and the video/print+lecture method was most effective among such three presentation methods as video/print+lecture, print/video, and print+lecture/video.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.68-73
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• 2013

In recent years, the developments in 3D technologies have initiated the commercialization of 3D services on mobile devices. For this purpose, stereoscopic 3D technology is used, which enables 3D TV on mobile devices including smartphone with glasses-free 3D viewing. As a result, the issues related with stereo imaging have been spotlighted greatly. Especially, three MPEG coding standards are provided for mobile 3D services, namely H.264/AVC with and without SEI message and H.264/MVC. In this respect, this paper presents an overview of developments in stereoscopic technologies for mobile devices to gain some perspective on the changes and progress. in this paper, we verified the availability of android based stereoscipic 3D technology related with mobile 3D TV and Smartphone with special emphasis on 3D video format and 3D features by various technollogy characteristics analysis.

• Journal of Chest Surgery
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• v.40 no.6 s.275
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• pp.459-462
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• 2007

Pericardial cysts are uncommon benign congenital mediastinal lesions and they are most often found in either cardiophrenic angle. We present here one case of atypically located pericardial cyst that was located in the sub-pulmonary region. The clinicians should take into consideration this entity in the differential diagnosis of cystic lesion of the mediastinum. The diagnostic difficulties that are encountered and the utility of video-assisted thoracoscopy are described.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.401-401
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• 2010

현대사회로 들어오면서 과거와 달리 외부에 있던 화장실이 내부로 들어오면서 변기 뚜껑을 닫지 않고 toilet flushing을 할 때 배변에 포함된 다량의 장티푸스, 포도상 구균 같은 종류의 세균이 화장실 곳곳에 퍼짐에 의하여 면역력이 약한 경우 여러 가지 세균성 질환 및 2차 감염을 통하여 장티푸스 및 피부 질환 등이 발생한다. 본 연구에서는 이런 감염을 최소화하기 위한 방법으로 플라즈마를 이용한 세변기 표면의 오염 방지처리 기술을 개발하는 것을 목표로 한다. 일차적으로 여러 가지 운용 조건에서 오염의 정도를 파악하고자 배변의 양에 따라 toilet flushing 시 피부 오염의 물질 노출 정도를 평가 하였다. 실험 방법은 배변을 모사하여 toilet system에 넣고 물을 내려 무게에 따른 물 튀김 정도와 위치 분포를 분석하였다. 밀가루 반죽의 무게가 증가하면서 피부에 닿는 물 튀김 면적이 특정 무게에서 최대 60.02 mm2까지 증가하다 감소했다. 또한 실제 측정 결과를 통하여 물 튀김의 분포가 뒤쪽에 집중되는 것을 볼 수 있었다. 이와 같이 실제 toilet flushing시 세균에 의하여 피부 오염 및 국부 감염이 발생할 수 있다는 것을 확인할 수 있었다. 또한 비데 동작 시 변기 내부에 잔존하는 세균 자체가 확산되는 정도를 3차원 유체 역학 모델링으로 예측하였다. 앞으로 세변기 뚜껑의 플라즈마 표면처리 및 toilet flushing 유로 디자인 개선을 통해 세균의 잔류 및 퍼짐을 최소화함으로써 최종적으로 세균성 질환을 줄일 수 있는 방법을 개발하는 것이 본 연구의 1단계 목표다.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.8.1-8
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• 1983

An anterior glottic web can be congenital or develop as a result of trauma. The congenital webs indicate failure of normal separation of the two vocal cord primordia and the cicatrical membrane caused by accidental and operative trauma. When the web is small it rarely produces significant sympto-matology but larger webs may produce stridor as well as hoaresness in various degrees. Achievement of epithelialization of the anterior commisure after excision of a web, thus preventing adhesions from forming between the denuded vocal cords, is the principle underlying the surgical treatment of anterior glottic webs. Recently the authors experienced a case of anterior glottic web which occured in a 23 year old man after repeat removal of a papilloma several times in child-hood. The patient received treatment of a web excision followed by placement of a gold keel between the cords in the anterior glottis.