• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11C
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• pp.917-928
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• 2010

In this paper, we propose an efficient and adaptive rate control in Frame-layer for H.264/AVC. For given QP, bits according to video characteristics, and current frame is close correlation between the adjacent frames. Using the statistical characteristic, we obtain change of occurrence bit about QP to apply the bit amount by QP from the video characteristic and applied in the estimated bit amount of the each unit of current frame. In addition, we use weight with QP and occurrence bit amount that is statistical information of encoded previous frames. Simulation results show that the proposed rate control scheme could not only achieves time saving of more than 99% over existing rate control algorithm, but also increase the average PSNR of reconstructed video for around 0.02~0.43 dB in all the sequences.

• Journal of KIISE:Databases
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• v.29 no.5
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• pp.358-366
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• 2002

Feature-based similarity retrieval become an important research issue in image database systems. The features of image data are useful to discrimination of images. In this paper, we propose the high speed k-Nearest Neighbor search algorithm based on Self-Organizing Maps. Self-Organizing Maps(SOM) provides a mapping from high dimensional feature vectors onto a two-dimensional space and generates a topological feature map. A topological feature map preserves the mutual relations (similarities) in feature spaces of input data, and clusters mutually similar feature vectors in a neighboring nodes. Therefore each node of the topological feature map holds a node vector and similar images that is closest to each node vector. We implemented a k-NN search for similar image classification as to (1) access to topological feature map, and (2) apply to pruning strategy of high speed search. We experiment on the performance of our algorithm using color feature vectors extracted from images. Promising results have been obtained in experiments.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.373-381
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• 1997

In order to investigate the drift of pesticides sprayed on Chinese cabbage, 7 pesticides chlorpyrifos, EPN, pirimiphos-methyl, phenthoate, tetradifon, dicofol and bifenthrin were applied in two sets of field tests. The pesticide residues were quantified bar multiple-residue analysis, in which the recovery rate was 78${\sim}$92% and standard deviation was ${\pm}0.683{\sim}52%$. It was found that most of the tested pesticides were spread by drift to neighbouring area and brought about the contamination of the unsprayed crops. The extent of drift varied depending upon the pesticide, distance and wind direction. The mean residue levels on unsprayed crops were 0.66% at 3 meter distance, 0.10% at 6 m distance and 0.05% at 9 m distance from the applied area and the maximum level was 1.83% of the residue on sprayed crops.

• Journal of Broadcast Engineering
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• v.17 no.1
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• pp.191-194
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• 2012

The split flag and the skip flag in CU syntax have high correlation on spatial domain as well as temporal domain. This paper suggests a method for enhancing coding efficiency by using not only spatial correlation but also temporal correlation when coding CU information. In the CABAC case, temporal collocated CU information is used for selecting context model of the split flag and the skip flag. In the CAVLC case, current CU information is estimated from temporal collocated CU information then encoded. As a result, a coding efficiency was increased by 0.1%~0.6% in CABAC, 0.1%~0.4% in CAVLC compared with HM 3.0. This method shows better performance on lowdelay condition which uses reference frame close to current frame.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6322-6328
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• 2014

Finite element analyses were performed to find out the load bearing behavior of three kinds of shallow foundations. The analysis results for strip footing showed that local shear failure mode could be observed for a zero dilatancy angle and general shear failure mode could be seen for non-zero dilatancy angles. The ultimate bearing loads for non-zero dilatancy angles were approximately 1.5 times higher than that of a zero dilatancy angle. General shear failure mode was observed for circular footing and square footing regardless of the dilatancy angle. The ultimate bearing loads for a non-zero dilatancy angle were slightly greater than that for a zero dilatancy angle. A comparison of the load-settlement curves for three kinds of footing showed that the load bearing capacities for non-zero dilatancy angle were greater than those for a zero-dilatancy angle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.454-463
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• 2013

Upon changing architectural education system into 5-year program, the design studio in university should meet the requirement in order to acquire the accredition. This study investigates on student' perceptions and responses, according to the configuration(open, mixed, closed), to their studio environment. Results and suggestions are as follows for all types: First, there should be space for individual activities for the student: Second, excluding space for excluding space for the individual work, seperated area must be provided for co-operative work, such as making models; Third, a clear territorial distintion between the individual and the co-work space should be able to set by the students, using. for instance, movable partition or corridor; Fourth, however, in line with the types, a seperated lecture or seminar room in the open type, a device to prevent distraction such as noise in the mixed type, and more space for co-work in the closed type are also suggested.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.157-164
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• 2010

This research was conducted to analyze the behavior of Single-PTAS (Single Post-Tensioned Approach Slab) under tensioning and environmental loads by performing field tests when the demonstration Single-PTAS was being constructed. The temperature measurement sensors were installed at different depths, and the displacements in the approach slab under environmental loads and tensioning were measured using displacement transducers. As an experimental result, an abrupt change in the longitudinal displacement due to tensioning was not observed. The daily temperature change in the approach slab was negligible where the depth is over about 35cm. The temperature gradient in the approach slab adjacent to bridge was smaller than that adjacent to pavement. The patterns and magnitudes of vertical displacements were directly related to the temperature gradient at the measuring location. The behavior of Single-PTAS was very similar to that of concrete pavement. Therefore, a new design methodology for approach slabs is needed to include the pavement concept and to overcome drawback of current design procedures based on the simple beam concept.

• Journal of Korean Society of Transportation
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• v.15 no.1
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• pp.175-192
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• 1997

첨단 교통정보 시스템(ATIS)의 핵심요소라고 할 수 있는 동적경로안내 시스템 (Dynamic Route Guidance System)은 운전자가 목적지에 도착하기까지 실시간 교통정보를 토대로 최적경로를 안내해줌으로써 날로 심화되고 있는 교통혼잡을 최소화 할 수 있으리라 기대를 모으고 있다. 특히 교통사고나 긴급 도로공사 등으로 인해 발생하는 돌발적 교통혼잡하에서는 DRGS의 역할이 더욱 커질 것으로 예상되고 있다. 본 논문은 돌발적 교통혼잡하에서 보다 효과적인 DRGS의 경로안내 전략을 수립하고 평가하는데 그 목적이 있다. 이를 위해 우선 하부구조기반 DRGS와 개인차량기반 DRGS의 장단점을 비교하고 시스템 아키텍쳐와 경로안내전략의 관계를 규명하였다. 또한 효율적인 경로안내를 위해 사용자평형 (User Equilibrium) 경로안내전략과 시스템 최적화(System Optimal) 경로안내 전략을 이상형교통망 (Idealized Network)을 통해 비교 분석하였다. 그리고 돌발적 교통 혼잡하에서 사용자평형 경로 안내를 사용할 경우 야기될 수 있는 Braess Paradox 문제와 시스템 최적경로안내를 사용할 경우 일어날 수 있는 사용자 호응도(User Compliance) 문제를 동시에 감안한 적응 형 경로안내 전략을 개발하였다. 이 방법은 위의 경로 안내 전략들이 가지고 있는 장단점을 상황에 따라 평가하여 경로안내 전략을 선택하는 과정을 수행시간을 절약하지 못할 것으로 평가되면 사용자 호응도를 고려하여 사용자 평형 전략을 선택하도록 하였다. 돌발적 교통 혼잡하에서 통행 시간을 동적으로 예측하기 위해서는 이산 확정적 대기행렬모형 (Discrete Deterministic Queueing Model)이 적용되었다. 한편, 적응형 전략의 효율성을 평가하기 위 해 이상형교통망과 실제 미국 Virginia 주의 Fairfax Country에 소재한 주간 고속도로 66번 과 인접 교통망을 대상으로 각종 돌발교통혼잡상황을 전제로 한 Traffic Simulation과 정보 제공 시나리오를 INTEGRATION Model을 사용하여 실행하였다. 그 결과 적응형전략이 단지 사용자평형 경로안내전략만 사용하는 경우에 비해 교통 혼잡도와 유고상황의 체류정도에 따라 3%에서 10%정도까지 전체통행시간을 절약할 수 있다는 결론을 얻었다.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.2
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• pp.49-56
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• 2020

We investigate the transmit power control algorithm for multi-access points environment. Each terminal may transmit a signal to one of these access points. Each access point may receive a signal from desired terminals as well as interference from neighbor terminals. In this paper, a transmit power control algorithm is developed such that the total transmit power is minimized, while each terminal meets the target signal to interference ratio (SIR) requirement. In particular, the effect of increasing the number of access-points on the total transmit power consumption is analyzed. Based on this analysis, we propose a convergence guaranteed power control algorithm. We prove that the proposed iterative algorithm always converges to the target SIR. In addition, we show that the proposed algorithm optimizes the transmit power level. Simulation results show that the proposed algorithm guarantees convergence regardless of the number of access points. We also observed that increasing the number of access points reduces the total transmit power consumption.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.543-549
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• 2000

Objective : In contrary to ganglion cyst that commonly develops in connective tissue of peripheral joint or tendon, spinal ganglion cysts have been rarely reported. The authors report five cases of spinal ganglion cysts which originated from posterior longitudinal ligament of the lumbar spine. Methods : The authors retrospectively analyzed clinical, radiological, and surgical findings of five cases of spinal ganglion cysts and speculated the pathogenesis of spinal ganglion cyst. Result : Cysts were excised totally and symptoms improved without complications in all cases. Intraoperative findings revealed cysts that were tightly adherent to posterior longitudinal ligament. Conclusion : Five cases of ganglion cyst which caused similar symptoms and signs those of lumbar disc herniations were excised successfully. MRI and operative findings suggested spinal ganglion cyst of posterior longitudinal ligament were closely associated with disc degeneration which imply disc degeneration or herniation may play an important role in the pathogenesis of ganglion cyst.