• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.53-56
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• 2016

본 논문에서는 HEVC 부호화시 코딩 트리 블록의 분할 구조를 고속 결정하는 방법을 제안한다. 코딩 트리블록은 다양한 크기의 코딩 블록으로 구성되어 부호화 효율을 향상시키지만, 구성되는 코딩 블록을 결정하기 위한 과정에서 많은 계산량을 필요로 하게 되어 부호화 시간을 증가시킨다. 제안하는 방법에서는 부호화 과정에서 복원된 잔차신호와 코딩 트리 블록의 분할 구조의 상관성을 이용하여 코딩 트리 블록의 분할 구조를 고속으로 결정하는 방법을 제시한다. 실험 결과를 통해 제안된 방법이 HM16.0 에 비해 random-access configuration 에서 50.98%, low-delay configuration 에서 43.77%의 부호화 시간을 감소시키는 것을 확인하였다. 이때, $BD-rate_{YUV}$ 증가는 각각 2.42%와 2.35%로 부호화 효율에는 미치는 영향은 낮았다.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.3-7
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• 2005

The structure of $IP^2$(IP based-IMT Network Platform) as ubiquitous platform is three-layered model : Middleware including NCPF(Network Control Platform) and SSPF(Service Support Platform), IP-BB(IP-Backbone), Access network including Sensor network. A mobility management(MM) architecture in NCPF is proposed for $IP^2$. It manages routing information and location information separately. The existing method of multicast control in $IP^2$ is Remote Subscription. But Remote Subscription has problem that should be reconstructed whole Multicast tree when sender moves. To solve this problem, we propose a way to put Multicast Manager in NCPF.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.2
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• pp.1-11
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• 2017

In this paper, we design and implement PADIL(Prediction And Detection of Information Leakage) system that predicts and detect information leakage behavior of insider by analyzing network traffic and applying a variety of machine learning methods. we defined the five-level information leakage model(Reconnaissance, Scanning, Access and Escalation, Exfiltration, Obfuscation) by referring to the cyber kill-chain model. In order to perform the machine learning for detecting information leakage, PADIL system extracts various features by analyzing the network traffic and extracts the behavioral features by comparing it with the personal profile information and extracts information leakage level features. We tested various machine learning methods and as a result, the DecisionTree algorithm showed excellent performance in information leakage detection and we showed that performance can be further improved by fine feature selection.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.1
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• pp.97-104
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• 2006

For successfully deploying many multicast service in the mobile environment, security infrastructures must be developed that manage the keys needed to provide access control to content. In this paper, we propose two methods for designing the key management scheme for the mobile multicast environment. The proposed schemes match the key management tree to the mobile multicast environment for localizing the delivery of he rekeying messages, reducing the communication costs, and solving the handoff problem in wireless region.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.535-544
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• 2009

This study was conducted to establish the selection criteria for the trees to be transplanted in the forest reserves which are expected to be developed in the future. The main task in this endeavor was to access the transplantability of the trees focused on their feature, diameter at breast height (D.B.H.), soil feature, etc. The selection of the trees for transplantation consisted of two stages. The first stage was to select trees on the basis of their indigenousness and forest successional stage. The second was to select trees on the basis of their type, D.B.H., the layers of soil, etc. At the first stage, the trees which are not indigenous or expected not to survive were eliminated from the selection list, and the result showed that approximately 5.9% (about 3,841 trees) of the trees proved to be inadequate for transplanting. At the second stage, the investigation of the trees based on the criteria of tree type, D.B.H., the layers of soil was carried out, and the result showed that approximately 33.7% (1,218) out of 3,613 trees turned out to adequate for transplanting however, 23.0% of the trees, which are 829 trees, were found to be impossible to transplant. In addition, it was discovered that in the case of approximately 43.3%(1,566 trees) of the trees there was little difference between transplanting cost and planting cost of new trees. Therefore the investigation indicated that it is more advisable to transplant trees to preserve the ecological environment. However, the study showed that there are other elements to be considered, such as tree feature and soil condition, for the successful tree transplantation, and the necessary information can be provided by the managing personnel who are in charge of the forest.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.233-246
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• 2005

To enhance the user response time of content-based retrieval service for multimedia information, several multi-dimensional index schemes have been proposed. M-tree, a well-known multidimensional index scheme is of metric space access method, and is based on the distance between objects in the metric space. However, since the overlap between index spaces of nodes might enlarge the number of nodes of M-tree accessed for query processing, the user response time for content-based multimedia information retrieval grows longer. In this paper, we propose a node split algorithm which is able to reduce the sire of overlap between index spaces of nodes in M-tree. In the proposed scheme, we choose a virtual center point as the routing object and entry redistribution as the postprocessing after node split in order to reduce the radius of index space of a node, and finally in order to reduce the overlap between the index spaces of routing nodes. From the experimental results, we can see the proposed split algorithm reduce the overlap between index space of nodes and finally enhance the user response time for similarity-based query processing.

• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.64-76
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• 2019

Aged apartments lack parking space and are suffering from severe parking difficulties due to the increase in the supply of private cars due to the economic improvement. Efficient remodeling technology is required as a way to solve the problem of a shortage of parking spaces, but there is a lack of establishing a technology for remodeling plans that can reflect the characteristics of various parks. This study was conducted to analyze the functions of the parking lot expansion technology using the technology tree and to derive the final technology through the function deployment. As a result of functional deployment of the plan to expand the parking lot, the fifth function was deployed and a total of 22 technologies were derived. Four types of technologies are categorized, four technologies for underground expansion, 12 technologies for underground and ground expansion, two technologies for ground expansion, and four technologies for ground-based expansion. As a result of the functional deployment of the main entrance plan, the fifth function was deployed and derived with 22 technologies. The total technologies were grouped into four categories, four technologies for direct underground entry, 11 technologies for indirect underground entry, three technologies for direct access to ground, and four technologies for indirect entry to ground. Through case verification, the detailed technologies applied to the semi-industrial complex of remodeling were identified and expert surveys and interviews were conducted to verify the adequacy of the technology tree.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.1-10
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• 2013

RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

• Journal of Broadcast Engineering
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• v.21 no.6
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• pp.929-943
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• 2016

This paper proposes the rate control algorithm based on the S-JND (Saliency-Just Noticeable Difference) model for considering perceptual visual quality. The proposed rate control algorithm employs the S-JND model to simultaneously reflect human visual sensitivity and human visual attention for considering characteristics of human visual system. During allocating bits for CTU (Coding Tree Unit) level in a rate control, the bit allocation model calculates the S-JND threshold of each CTU in a picture. The threshold of each CTU is used for adaptively allocating a proper number of bits; thus, the proposed bit allocation model can improve perceptual visual quality. For performance evaluation of the proposed algorithm, the proposed algorithm was implemented on HM 16.9 and tested for sequences in Class B and Class C under the CTC (Common Test Condition) RA (Random Access), Low-delay B and Low-delay P case. Experimental results show that the proposed method reduces the bit-rate of 2.3%, and improves BD-PSNR of 0.07dB and bit-rate accuracy of 0.06% on average. We achieved MOS improvement of 0.03 with the proposed method, compared with the conventional method based on DSCQS (Double Stimulus Continuous Quality Scale).

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.1-10
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• 1998

The idea of level-of-detail based on multiresolution model is gaining popularity as a natural means of handling the complexity regarding the realtime rendering of virtual environments. To generate an effective multiresolution model, we should capture the prominent visual features in the process of simplifying original complex model. In this paper, we incorporate view dependent features such as silhouette features and backface features, to the generation process of multiresolution model. To capture the view directional parameter, we propose multiresolution view sphere. View sphere maps the directional relationship between object surface and the view. Using the view sphere, coherence in the directional space is mapped into spatial coherence in the view sphere. View sphere is generated in multiresolution fashion to simplify the object. To access multiresolution view sphere efficiently, we devise quad tree for the view sphere. We also devise a mechanism for realtime simplification process using proposed view sphere. Using proposed mechanism, regenerating simplified model in realtime is effectively done in the order of number of rendered vertices.