• Title/Summary/Keyword: New Algorithm

Search Result 11,778, Processing Time 0.042 seconds

ROBUST TRANSMISSION OF VIDEO DATA STREAM OVER WIRELESS NETWORK BASED ON HIERARCHICAL SYNCHRONIZATION

  • Jung, Han-Seung;Kim, Rin-Chul;Lee, Sang-Uk
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 1998.06b
    • /
    • pp.5-9
    • /
    • 1998
  • In this paper, we propose an error-resilient transmission technique for the H.263 video data stream over wireless networks. The proposed algorithm employs bit rearrangement hierarchically, providing the robust and exact synchronization against the bit errors, without requiring extra redundant information. In addition, we propose the recovery algorithm for the lost or erroneous motion vectors. We implement the encoder and decoder, based on the H.263 standard, and evaluate the proposed algorithm through intensive computer simulation. The experimental results demonstrate that the proposed algorithm yields good image quality, in spite of the channel errors, and prevents the error propagation both in the spatial and the temporal domain efficiently.

  • PDF

A new line coding algorithm for power spectrum suppression at DC and nyquist frequency (직류 및 나이퀴스트 주파수에서 전력 스펙트럼 억제를 위한 새로운 선로 부호화 알고리즘)

  • 김용호;김대영
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.23 no.4
    • /
    • pp.815-820
    • /
    • 1998
  • A new coding algorithm which has spectrum notches at the DC and Nyquist Frequency for maximizing the effect of the in-band pilot insertion in order to make the symbol timing or carrier recovery easy is proposed. It is shown that this algorithm uses one encoder and gives the similar spectrum characteristics to that of the existing OF00 code which uses two encoder. In this paper, the proposed new coding algorithm is explained andits spectrum characteristics is compared with the of OF00 code using computer simulation.

  • PDF

A Study on New Algorithm for K Shortest Paths Problem (복수최단경로의 새로운 해법 연구)

  • Chang ByungMan
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 2002.05a
    • /
    • pp.8-14
    • /
    • 2002
  • This article presents a new algorithm for the K Shortest Paths Problem which develops initial K shortest paths, and repeal to expose hidden shortest paths with dual approach and to replace the longest path in the present K paths. The initial solution which comprises K shortest paths among shortest paths to traverse each arc is made from bidirectional Dijkstra algorithm. When a crossing node that have two or more inward arcs is found at least three time by turns in this K shortest paths, one inward arc of this crossing node, which has minimum detouring distance, is chosen, and a new path is exposed with joining a detouring subpath from source to this inward arc and a spur of a feasible path from this crossing node to sink. This algorithm, requires worst case time complexity of $O(Kn^2),\;and\;O(n^2)$ in the case $K{\leq}3$.

  • PDF

A New Reflection coefficient-Estimation Algorithm for Linear Prediction (선형 예측을 위한 새로운 반사계열 추정 알고리즘)

  • 조기원;김수중
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.19 no.4
    • /
    • pp.1-5
    • /
    • 1982
  • A new algorithm, based upon a lattice formulation, is presented for linear prediction. The output of the algorithm is the reflection coefficients that guarantee the stability of the all-pole model. The equations are derived that compute the covariance of the residuals recursively at each prediction stage, and in processing of computing that eqations, the reflection coefficients are estimated without computing the predictor coefficients. Comparing with covariance-lattice method, it can be said that the new algorithm reduce the number of computations to about half and is more efficient for fitting of the high-order model.

  • PDF

A Novel Subspace Tracking Algorithm and Its Application to Blind Multiuser Detection in Cellular CDMA Systems

  • Ali, Imran;Kim, Doug-Nyun;Song, Yun-Jeong;Azeemi, Naeem Zafar
    • Journal of Communications and Networks
    • /
    • v.12 no.3
    • /
    • pp.216-221
    • /
    • 2010
  • In this paper, we propose and develop a new algorithm for the principle subspace tracking by orthonormalizing the eigenvectors using an approximation of Gram-Schmidt procedure. We carry out a novel mathematical derivation to show that when this approximated version of Gram-Schmidt procedure is added to a modified form of projection approximation subspace tracking deflation (PASTd) algorithm, the eigenvectors can be orthonormalized within a linear computational complexity. While the PASTd algorithm tries to extracts orthonormalized eigenvectors, the new scheme orthonormalizes the eigenvectors after their extraction, yielding much more tacking efficiency. We apply the new tracking scheme for blind adaptive multiuser detection for non-stationary cellular CDMA environment and use extensive simulation results to demonstrate the performance improvement of the proposed scheme.

Iterative Algorithm for a New System of Variational Inclusions with B-monotone Operators in Banach Spaces

  • Lee, Sang Keun;Jeong, Jae Ug
    • Kyungpook Mathematical Journal
    • /
    • v.53 no.3
    • /
    • pp.307-318
    • /
    • 2013
  • In this paper, we introduce and study a new system of variational inclusions with B-monotone operators in Banach spaces. By using the proximal mapping associated with B-monotone operator, we construct a new iterative algorithm for approximating the solution of this system of variational inclusions. We also prove the existence of solutions and the convergence of the sequences generated by the algorithm for this system of variational inclusions. The results presented in this paper extend and improve some known results in the literature.

ITERATIVE ALGORITHM FOR COMPLETELY GENERALIZED QUASI-VARIATIONAL INCLUSIONS WITH FUZZY MAPPINGS IN HILBERT SPACES

  • Jeong, Jae-Ug
    • Journal of applied mathematics & informatics
    • /
    • v.28 no.1_2
    • /
    • pp.451-463
    • /
    • 2010
  • In this paper, we introduce and study a class of completely generalized quasi-variational inclusions with fuzzy mappings. A new iterative algorithm for finding the approximate solutions and the convergence criteria of the iterative sequences generated by the algorithm are also given. These results of existence, algorithm and convergence generalize many known results.

A New Item Recommendation Procedure Using Preference Boundary

  • Kim, Hyea-Kyeong;Jang, Moon-Kyoung;Kim, Jae-Kyeong;Cho, Yoon-Ho
    • Asia pacific journal of information systems
    • /
    • v.20 no.1
    • /
    • pp.81-99
    • /
    • 2010
  • Lately, in consumers' markets the number of new items is rapidly increasing at an overwhelming rate while consumers have limited access to information about those new products in making a sensible, well-informed purchase. Therefore, item providers and customers need a system which recommends right items to right customers. Also, whenever new items are released, for instance, the recommender system specializing in new items can help item providers locate and identify potential customers. Currently, new items are being added to an existing system without being specially noted to consumers, making it difficult for consumers to identify and evaluate new products introduced in the markets. Most of previous approaches for recommender systems have to rely on the usage history of customers. For new items, this content-based (CB) approach is simply not available for the system to recommend those new items to potential consumers. Although collaborative filtering (CF) approach is not directly applicable to solve the new item problem, it would be a good idea to use the basic principle of CF which identifies similar customers, i,e. neighbors, and recommend items to those customers who have liked the similar items in the past. This research aims to suggest a hybrid recommendation procedure based on the preference boundary of target customer. We suggest the hybrid recommendation procedure using the preference boundary in the feature space for recommending new items only. The basic principle is that if a new item belongs within the preference boundary of a target customer, then it is evaluated to be preferred by the customer. Customers' preferences and characteristics of items including new items are represented in a feature space, and the scope or boundary of the target customer's preference is extended to those of neighbors'. The new item recommendation procedure consists of three steps. The first step is analyzing the profile of items, which are represented as k-dimensional feature values. The second step is to determine the representative point of the target customer's preference boundary, the centroid, based on a personal information set. To determine the centroid of preference boundary of a target customer, three algorithms are developed in this research: one is using the centroid of a target customer only (TC), the other is using centroid of a (dummy) big target customer that is composed of a target customer and his/her neighbors (BC), and another is using centroids of a target customer and his/her neighbors (NC). The third step is to determine the range of the preference boundary, the radius. The suggested algorithm Is using the average distance (AD) between the centroid and all purchased items. We test whether the CF-based approach to determine the centroid of the preference boundary improves the recommendation quality or not. For this purpose, we develop two hybrid algorithms, BC and NC, which use neighbors when deciding centroid of the preference boundary. To test the validity of hybrid algorithms, BC and NC, we developed CB-algorithm, TC, which uses target customers only. We measured effectiveness scores of suggested algorithms and compared them through a series of experiments with a set of real mobile image transaction data. We spilt the period between 1st June 2004 and 31st July and the period between 1st August and 31st August 2004 as a training set and a test set, respectively. The training set Is used to make the preference boundary, and the test set is used to evaluate the performance of the suggested hybrid recommendation procedure. The main aim of this research Is to compare the hybrid recommendation algorithm with the CB algorithm. To evaluate the performance of each algorithm, we compare the purchased new item list in test period with the recommended item list which is recommended by suggested algorithms. So we employ the evaluation metric to hit the ratio for evaluating our algorithms. The hit ratio is defined as the ratio of the hit set size to the recommended set size. The hit set size means the number of success of recommendations in our experiment, and the test set size means the number of purchased items during the test period. Experimental test result shows the hit ratio of BC and NC is bigger than that of TC. This means using neighbors Is more effective to recommend new items. That is hybrid algorithm using CF is more effective when recommending to consumers new items than the algorithm using only CB. The reason of the smaller hit ratio of BC than that of NC is that BC is defined as a dummy or virtual customer who purchased all items of target customers' and neighbors'. That is centroid of BC often shifts from that of TC, so it tends to reflect skewed characters of target customer. So the recommendation algorithm using NC shows the best hit ratio, because NC has sufficient information about target customers and their neighbors without damaging the information about the target customers.

An Efficient Genetic Algorithm for the Allocation and Engagement Scheduling of Interceptor Missiles (효율적인 유전 알고리즘을 활용한 요격미사일 할당 및 교전 일정계획의 최적화)

  • Lee, Dae Ryeock;Yang, Jaehwan
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.39 no.2
    • /
    • pp.88-102
    • /
    • 2016
  • This paper considers the allocation and engagement scheduling problem of interceptor missiles, and the problem was formulated by using MIP (mixed integer programming) in the previous research. The objective of the model is the maximization of total intercept altitude instead of the more conventional objective such as the minimization of surviving target value. The concept of the time window was used to model the engagement situation and a continuous time is assumed for flying times of the both missiles. The MIP formulation of the problem is very complex due to the complexity of the real problem itself. Hence, the finding of an efficient optimal solution procedure seems to be difficult. In this paper, an efficient genetic algorithm is developed by improving a general genetic algorithm. The improvement is achieved by carefully analyzing the structure of the formulation. Specifically, the new algorithm includes an enhanced repair process and a crossover operation which utilizes the idea of the PSO (particle swarm optimization). Then, the algorithm is throughly tested on 50 randomly generated engagement scenarios, and its performance is compared with that of a commercial package and a more general genetic algorithm, respectively. The results indicate that the new algorithm consistently performs better than a general genetic algorithm. Also, the new algorithm generates much better results than those by the commercial package on several test cases when the execution time of the commercial package is limited to 8,000 seconds, which is about two hours and 13 minutes. Moreover, it obtains a solution within 0.13~33.34 seconds depending on the size of scenarios.