• Journal of the Korea Computer Industry Society
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• v.3 no.2
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• pp.235-242
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• 2002

To minimize restructuring cost of a tree, experiments were conducted to collect quantitative information of searching efficiencies varying degrees of imbalance in a binary search tree. Degrees of tree imbalance were measured by a balance factor, an absolute value of height difference of left subtree and right subtree in a binary search tree. The average number of comparisons increased (p＜0.01), and searching efficiency of O(n) was more appropriate rather than O(logn), as degrees of imbalance in a binary search tree deteriorated. However, there were no significant differences of searching efficiencies in height balanced trees and trees with subtrees to have height 3 less than the other (p＞0.05). Therefore, the findings would be applicable to maintain searching efficiency of a software with a binary search tree.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1B
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• pp.18-28
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• 2004

Efficient hardware implementation of address lookup is one of the most important design issues of internet routers. Address lookup significantly impacts router performance since routers need to process tens-to-hundred millions of packets per second in real time. In this paper, we propose a practical IP address lookup structure based on the binary tree of prefixes of different lengths. The proposed structure produces multiple balanced trees, and hence it solve the issues due to the unbalanced binary prefix tree of the existing scheme. The proposed structure is implemented using pipelined binary search combined with a small size TCAM. Performance evaluation results show that the proposed architecture requires a 2000-entry TCAM and total 245 kbyte SRAMs to store about 30,000 prefix samples from MAE-WEST router, and an address lookup is achieved by a single memory access. The proposed scheme scales very well with both of large databases and longer addresses as in IPv6.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.369-372
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• 2003

In this paper, we propose impr oved binary tree vector quantization based on spatial sensitivity which is one of the human visual properties. We combine the weights based on spatial masking effect according to changes of three primary colors in blocks of images with the process of splitting nodes using eigenvector in binary tree vector quantization. The test results show that the proposed method generates the quantized images with fine color and performs better than the conventional method in terms of clustering the similar regions. Also the proposed method can get the better result in subjective qualify test and PSNR.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.218-223
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• 1995

A new design scheme of a binary decision tree is proposed. In this scheme a binary decision tree is constructed by using genetic algorithm and FCM algorithm. At each node optimal or near-optimal feature or feature subset among all the available features is selected based on fitness function in genetic algorithm which is inversely proportional to classification error, balance between cluster, number of feature used. The proposed design scheme is applied to the handwtitten alphabetic characters. Experimental results show the usefulness of the proposed scheme.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.7_8
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• pp.381-386
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• 2003

In this paper, we consider the problem of embedding complete binary trees into 3-dimensional meshes. The method of embedding a complete binary tree into 3-dimensional mesh with the link congestion two is considered in [1], and the embedding in [2] shows that a complete binary tree can be embedded into a ,3-dimensional mesh of expansion 1.27. The proposed embedding in this paper shows that a complete binary tree can be embedded into a 3-dimensional mesh of expansion approximately 1.125 with the link congestion one, using the dimensional ordered routing. Such method yields some improved features in terms of minimizing the link congestion or the expansion of embedding comparing to the previous results.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.133-136
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• 2002

This paper presents a new method of Huffman decoding which gives a significant improvement of processing efficiency based on the reconstruction of an efficient one-dimensional array data structure incorporating the numeric interpretation of the accrued codewords in the binary tree. In the Proposed search method, the branching address is directly obtained by the arithematic operation with the incoming digit value eliminating the compare instruction needed in the binary tree search. The proposed search method gives 30% of improved Processing efficiency and the memory space of the reconstructed Huffman table is reduced to one third compared to the ordinary ‘compare and jump’ based binary tree. The experimental result with the six MPEG-2 AAC test files also shows about 198% of performance improvement compared to those of the widely used conventional sequential search method.

• Journal of The Korean Astronomical Society
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• v.27 no.1
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• pp.13-29
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• 1994

We have constructed a 3-dim hydrodynamics code called BTSPH. The fluid dynamics part of the code is based on the smoothed particle hydrodynamics (SPH), and for its Poisson solver the binary tree (BT) scheme is employed. We let the smoothing length in the SPH algorithm vary with space and time, so that resolution of the calculation is considerably enhanced over the version of SPH with fixed smoothing length. The binary tree scheme calculates the gravitational force at a point by collecting the monopole forces from neighboring particles and the multipole forces from aggregates of distant particles. The BTSPH is free from geometric constraints, does not rely on grids, and needs arrays of moderate size. With the code we have run the following set of test calculations: one-dim shock tube, adiabatic collapse of an isothermal cloud, small oscillation of an equilibrium polytrope of index 3/2, and tidal encounter of the polytrope and a point mass perturber. Results of the tests confirmed the code performance.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.143-144
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• 2018

Edge Computing은 분담을 통해 네트워크의 부담을 줄일 수 있는 IoT 네트워크에 적합한 방법으로, 데이터를 전송하고 받는 과정에서 네트워크의 대역폭을 사용하는 대신 서로 연결된 노드들이 협력해서 데이터를 처리하고, 네트워크 말단에서의 데이터 처리가 허용되어 데이터 센터의 부담을 줄일 수 있다. 트리구조는 데이터 구조의 하나로, 데이터 항목의 한 묶음인 세그먼트를 나뭇가지처럼 연결한 것을 의미하여 분산된 데이터를 군집할 수 있다. 본 논문에서는 Edge Computing 환경에서 트리 구조를 이용하여 인덱스를 관리하는 모델을 알아보기 위해 이진 탐색 트리 중 AVL tree와 Paged Binary tree에 대해 서술하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.2
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• pp.79-86
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• 2019

For decades, in-memory data structures have been designed for DRAM-based main memory that provides symmetric read/write performances and has no limited write endurance. However, such data structures provide sub-optimal performance for NVM as it has different characteristics to DRAM. With this motivation, we rethink a conventional red-black tree in terms of its efficacy under NVM settings. The original red-black tree constantly rebalances sub-trees so as to export fast access time over dataset, but it inevitably increases the write traffic, adversely affecting the performance for NVM with a long write latency and limited endurance. To resolve this problem, we present a variant of the red-black tree called a hierarchical balanced binary search tree. The proposed structure maintains multiple keys in a single node so as to amortize the rebalancing cost. The performance study reveals that the proposed hierarchical binary search tree effectively reduces the write traffic by effectively reaping the high capacity of NVM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.911-919
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• 2004

IP address lookup is one of the essential functions on internet routers, and it determines overall router performance. The most important evaluation factor for software-based IP address lookup is the number of the worst case memory accesses. Binary prefix tree (BPT) scheme gives small number of worst case memory accesses among previous software-based schemes. However the tree structure of BPT is normally unbalanced. In this paper, we propose weighted binary prefix tree (WBP) scheme which generates nearly balanced tree, through combining the concept of weight to the BPT generation process. The proposed WBPT gives very small number of worst case memory accesses compared to the previous software-based schemes. Moreover the WBPT requires comparably small size of memory which can be fit within L2 cache for about 30,000 prefixes, and it is rather simple for prefix addition and deletion. Hence the proposed WBPT can be used for software-based If address lookup in practical routers.