• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.4
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• pp.255-267
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• 2020

Under SLD conditions, due to the large size of droplets, physical phenomena such as wall-droplet interaction and deformation have a significant effect on the icing process. Accordingly, many studies have been conducted in order to computationally simulate SLD effects. As one of the efforts, post-processing method have been proposed to describe wall-droplet interaction effect, which modified collection efficiency using Wright model. However, since the model doesn't properly consider the wall condition, it still overestimated collection efficiency and impingement limit. To solve this problem, impingement areas were divided into 3 different regions, and the post-processing method was introduced with the new wall-droplet interaction model developed based on Bai and Gosman rebound model. In order to consider the effect of deformation, the most suitable model was selected by comparing the deformation models used in the various icing codes. As a result, the modified post-processing method showed improved accuracy in predicting the impingement limits and collection efficiency by further estimating mass flux loss due to rebound, and it was observed that the result was the closest to the experimental data when the deformation effect was included by using Wiegand model.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.238-240
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• 2006

네트워크상에서 발생하는 다양한 형태의 대량의 데이터를 정확하고 효율적으로 분석하기 위해 설계되고 있는 마이닝 시스템들은 목표지향적으로 훈련데이터들을 어떻게 구축하여 다룰 것인지에 대한 문제보다는 대부분 얼마나 많은 데이터 마이닝 기법을 지원하고 이를 적용할 수 있는지 등의 기법에 초점을 두고 있다. 따라서, 점점 더 에이전트화, 분산화, 자동화 및 은닉화 되는 최근의 보안공격기법을 정확하게 탐지하기 위한 방법은 미흡한 실정이다. 본 연구에서는 유비쿼터스 환경 내에서 발생 가능한 문제 중 복잡하고 지능화된 침입패턴의 탐지를 위해 데이터 마이닝 기법과 결함허용방법을 이용하는 개선된 학습알고리즘과 후처리 방법에 의한 RTPID(Refinement Training and Post-processing for Intrusion Detection)시스템을 제안한다. 본 논문에서의 RTPID 시스템은 active learning과 post-processing을 이용하여, 네트워크 내에서 발생 가능한 침입형태들을 정확하고 효율적으로 다루어 분석하고 있다. 이는 기법에만 초점을 맞춘 기존의 데이터마이닝 분석을 개선하고 있으며, 특히 제안된 분석 프로세스를 진행하는 동안 능동학습방법의 장점을 수용하여 학습효과는 높이며 비용을 감소시킬 수 있는 자가학습방법(self learning)방법의 효과를 기대할 수 있다. 이는 관리자의 개입을 최소화하는 학습방법이면서 동시에 False Positive와 False Negative 의 오류를 매우 효율적으로 개선하는 방법으로 기대된다. 본 논문의 제안방법은 분석도구나 시스템에 의존하지 않기 때문에, 유사한 문제를 안고 있는 여러 분야의 네트웍 환경에 적용될 수 있다.더욱 높은성능을 가짐을 알 수 있다.의 각 노드의 전력이 위험할 때 에러 패킷을 발생하는 기법을 추가하였다. NS-2 시뮬레이터를 이용하여 실험을 한 결과, 제안한 기법이 AOMDV에 비해 경로 탐색 횟수가 최대 36.57% 까지 감소되었음을 알 수 있었다.의 작용보다 더 강력함을 시사하고 있다.TEX>로 최고값을 나타내었으며 그 후 감소하여 담금 10일에는 $1.61{\sim}2.34%$였다. 시험구간에는 KKR, SKR이 비교적 높은 값을 나타내었다. 무기질 함량은 발효기간이 경과할수록 증하였고 Ca는 $2.95{\sim}36.76$, Cu는 $0.01{\sim}0.14$, Fe는 $0.71{\sim}3.23$, K는 $110.89{\sim}517.33$, Mg는 $34.78{\sim}122.40$, Mn은 $0.56{\sim}5.98$, Na는 $0.19{\sim}14.36$, Zn은 $0.90{\sim}5.71ppm$을 나타내었으며, 시험구별로 보면 WNR, BNR구가 Na만 제외한 다른 무기성분 함량이 가장 높았다.O to reduce I/O cost by reusing data already present in the memory of other nodes. Finally, chunking and on-line compression mechanisms are included in both models. We demonstrate that we can obtain significantly high-performanc

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.3
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• pp.1-7
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• 2014

Purpose : The purpose of this study was to evaluate the influence of Lowenstein Occupational Therapy Cognitive Assessment(LOTCA) and Activities of Daily Living(ADL) by CogPack program in elderly with Alzheimer's dementia. Method : The subjects of this study, elderly diagnosed with Alzheimer's dementia, 8 patients were picked up, who were agreed with this research. Cognitive training for 6 weeks, which consisted of 3 times per week, 30 min of memory, attention and performance with cogpack program. Cognitive and ADL measured by LOTCA and FIM. The SPSS Ver. 14.0 statistical program was used for data processing. The significance level for statistical inspection was set as 0.05. Result : In comparison of LOTCA was significantly correlated in the pre and post test but FIM was not significantly correlated in the pre and post test. Conclusion : Therefore, the CogPack program is useful to improve the LOTCA in elderly with Alzheimer's dementia.

• The KIPS Transactions:PartA
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• v.17A no.4
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• pp.167-172
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• 2010

This paper proposes a set of runtime test models for priority queues and shows the runtime test results based on the proposed test models for the representative priority queues: the traditional heap, post-order heap, and pairing heap. Among these heaps, the traditional heap is the worst in time complexity analyzed. But, according to our experimental results based on the test models proposed, it is shown that the slowest one is the pairing heap that utilizes pointers and the fastest one is the traditional heap. For the two implicit heaps, these results are in contrary to the fact that the post-order heap is better than the traditional heap in time complexity analyzed.

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.2
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• pp.13-20
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• 2014

Purpose : The purpose of this study was to evaluate the influence of cognition and executive function by computer - based attention program in vascular dementia. Method : The subjects of this study, old man diagnosed with vascular dementia, 12 patients were picked up, who were agreed with this research and were having hospital care for 4 weeks at nursing care centers. Computer-based attention program was applied to vascular dementia. Cognitive function measured by a K-MMSE and executive function measured by ACL. The SPSS Ver. 18.0 statistical program was used for data processing. The significance level for statistical inspection was set as 0.05. Result : In comparison of cognitive function was not significantly correlated in the pre and post test and executive function was significantly correlated in the pre and post test. Conclusion : Therefore, the computer-based attention program is useful to improve the cognitive and executive function in elderly with vascular dementia.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.4
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• pp.662-674
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• 1997

In order to post process the vector-quantized images employing the theory of projections onto convex sets or the constrained minimization technique, the the projector onto QCS(quantization constraint set) as well as the filter that smoothes the lock boundaries should be investigated theoretically. The basic idea behind the projection onto QCS is to prevent the processed data from diverging from the original quantization region in order to reduce the blurring artifacts caused by a filtering operation. However, since the Voronoi regions in order to reduce the blurring artifacts caused by a filtering operation. However, since the Voronoi regions in the vector quantization are arbitrarilly shaped unless the vector quantization has a structural code book, the implementation of the projection onto QCS is very complicate. This paper mathematically analyzes the projection onto QCS from the viewpoit of minimizing the mean square error. Through the analysis, it has been revealed that the projection onto a subset of the QCS yields lower distortion than the projection onto QCS does. Searching for an optimal constraint set is not easy and the operation of the projector is complicate, since the shape of optimal constraint set is dependent on the statistical characteristics between the filtered and original images. Therefore, we proposed a hyper-cube as a constraint set that enables a simple projection. It sill be also shown that a proper filtering technique followed by the projection onto the hyper-cube can reduce the quantization distortion by theory and experiment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1126-1132
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• 2009

Bridge structures are designed to support ordinary loadings such as vehicles, wind, temperature and current as well as unexpected loadings like earthquakes and storm. Especially, the displacement of Flexible bridges like an suspension bridge under ordinary loading conditions is necessary to be monitored. In case of long span bridges, there are some difficulties in monitoring the displacement of center of the main span using traditional laser displacement sensors. In this study, the static and dynamic displacement responses due to vehicle loadings were measured by DGPS(differential global positioning system) technique. The displacement response data were compared with data obtained from traditional laser displacement sensors so that the static and dynamic behavior of the bridge under vehicle loadings was examined and the applicability of the displacement response measurement using DGPS technique was verified. The static and dynamic loading test for an self-anchored suspension bridge, So-rok Bridge, was performed using vehicles. The displacement response from DGPS technique and that from laser displacement sensors of the bridge monitoring system were compared. The amplitude of white noise from DGPS based measurement was about 7 mm and that of laser displacement sensor based measurement was about 3 mm. On the other hand, dynamic behavior of the center of main span from DGPS based measurement showed better agreement with influence line of the bridge than that from laser displacement sensors. In addition, there were some irregular and discontinuous variation of data due to the instability of GPS receivers or frequent appearance of GPS satellites. Post-processing via the reference station close to an observation post provided by NGII(National Geographic Information Institute) will be a counter-plan for these defects.

• Journal of Korea Trade
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• v.27 no.2
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• pp.1-21
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• 2023

Purpose - The bank payment obligation is a transaction method that combines the certainty of L/C transactions with the speed of remittance payments, so the main purpose of this study is to highlight the superiority of bank payment obligation, noting the difference between bank payment obligation and L/C transactions. In addition, we would like to examine how bank payment obligations can actually be applied to support various valuable proposals such as post-shipment and post-shipment finance according to the payment process.. Design/methodology - This study focused on literature based on data from ICC and SWIFT along with previous domestic and international studies. In terms of a research method, a literature review was adopted with electronic trade-related books and journals and policy-related reports from international trade-related agencies. Findings - Unlike L/C transaction, BPO transaction verify the data inquiry process based only on the combination result of the established baseline and dataset. Accordingly, it is superior to L/C transaction in that there is no confrontation between the parties over the results of the inquiry, and clear transactions are possible according to the principle of proof after prepayment. In addition, unlike credit transactions, data inconsistency acceptance procedures confirm payment obligations in consideration of importers' intentions. As a result, as long as trade documents are in the hands of exporting countries, flexible document disposition is possible in response to the situation after payment, which is more advantageous than L/C transaction. Originality/value - Specifically, from the importer's point of view, BPO transactions have the advantage of reducing the manpower required to prepare and review trade documents and processing transaction negotiations with exporters advantageously due to the strength of payment obligations. From the perspective of the exporter, it has the advantage of enabling rapid recovery of trade payments and reducing the risk of importer's cancellation of transactions or content change. From the perspective of participating banks, it is possible to strengthen relations with importer and obtain high commission income by increasing the role of bank reduced by reducing L/C transaction.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.692-702
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• 2009

Real-time virtual studios which could run only on expensive workstations are now available for personal computers thanks to the recent development of graphics hardware. Nevertheless, graphics are rendered off-line in the post production stage in film or TV drama productions, because the graphics' quality is still restricted by the real-time hardware. Software-based camera tracking methods taking only the source video into account take much computation time, and often shows unstable results. To overcome this restriction, we propose a system that stores camera motion data from sensors at shooting time as common virtual studios and uses them in the post production stage, named as POVIS(post virtual imaging system). For seamless registration of graphics onto the camera video, precise zoom lens calibration must precede the post production. A practical method using only two planar patterns is used in this work. We present a method to reduce the camera sensor's error due to the mechanical mismatch, using the Kalman filter. POVIS was successfully used to track the camera in a documentary production and saved much of the processing time, while conventional methods failed due to lack of features to track.

• The Transactions of the Korea Information Processing Society
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• v.4 no.5
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• pp.1297-1307
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• 1997

This paper presents a multimedia mail system which transmit and redeive multimedia mailing messges on Intemet.This mail system is an extension of the exsting e-mail system for multimedia uncluding,text,image,MPEG video,and binary data,The MIME(Multipurpose Intert Mail Extensions)format,which is an extension of REF-822 maill format,is used to reprssent multimedia,and SMTP(Simple Mail Transfer Protocol)is utilized as a mail transport prttocol.The IMAP(Intenet Mail Access Protcol)which privides more functions than the widely used POP(Post Office Protocol)is used as a mailbox retrival protocol.The mail client is complemented on a multimedia PC while the server is implemented on a UNIX system.In the mail system, a mail sending program allows a user to attach binary files such as Postscript files and MPEG compressed video,while a receiving program provides direct interface to application programs to play back received multimedia mail messages.