• Structural Engineering and Mechanics
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• v.44 no.2
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• pp.179-196
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• 2012

An eigenspace projection clustering method is proposed for structural damage detection by combining projection algorithm and fuzzy clustering technique. The integrated procedure includes data selection, data normalization, projection, damage feature extraction, and clustering algorithm to structural damage assessment. The frequency response functions (FRFs) of the healthy and the damaged structure are used as initial data, median values of the projections are considered as damage features, and the fuzzy c-means (FCM) algorithm are used to categorize these features. The performance of the proposed method has been validated using a three-story frame structure built and tested by Los Alamos National Laboratory, USA. Two projection algorithms, namely principal component analysis (PCA) and kernel principal component analysis (KPCA), are compared for better extraction of damage features, further six kinds of distances adopted in FCM process are studied and discussed. The illustrated results reveal that the distance selection depends on the distribution of features. For the optimal choice of projections, it is recommended that the Cosine distance is used for the PCA while the Seuclidean distance and the Cityblock distance suitably used for the KPCA. The PCA method is recommended when a large amount of data need to be processed due to its higher correct decisions and less computational costs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1397-1405
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• 2012

Cooperative communications play a important role in increasing frame transmission rate at wireless communication networks where frequency resource is strictly limited. In this paper, we did a research on how to select the helper nodes that are very import in cooperative communications. As a prelude study in this research field, we carried out performance comparison of three helper node selection schemes using computer simulation. The system throughput was used as the performance measure and the random way point mobility model, where every communicating nodes move around within the designated communication range, was used.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.387-391
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• 2007

A proper selection of formwork greatly affects project success in tall building construction. The tall building construction, however, has not been selected properly using the characteristics by formwork and demands the comprehensive consideration of cost, duration, quality, safety, and environment. Therefore, this study compares and analyzes the application by formwork of five aspects. In order to perform an analysis, the questionnaire was performed to research the priority order of management as determining formwork and application by formwork of tall building construction engineers. This study is expected to help reasonable selection of formwork.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5C
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• pp.371-377
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• 2008

In this paper, we present a framework for vision-based two-arm gesture recognition. To capture the motion information of the hands, we perform color-based tracking algorithm using adaptive kernel for each frame. And a feature selection algorithm is performed to classify the motion information into four different phrases. By using gesture phrase information, we build a gesture model which consists of a probability of the symbols and a symbol sequence which is learned from the longest common subsequence. Finally, we present a similarity measurement for two-arm gesture recognition by using the proposed gesture models. In the experimental results, we show the efficiency of the proposed feature selection method, and the simplicity and the robustness of the recognition algorithm.

• Journal of the Korea Computer Industry Society
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• v.2 no.7
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• pp.997-1014
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• 2001

In this paper, we propose a method for dynamic selection of unrestricted motion vector(UMV) or default prediction mode(DPM) in H.263 bit stream. For this, we use the error of compensated image and the magnitude of motion vector. In the proposed strategy, the UMV mode is dynamically applied in a frame according to average magnitude of motion vector and error of compensated image. This scheme has improved the quality of image compared to the fixed mode UMV or DPM only. Number of searching points are greatly reduced when comparing to UMV. The Proposed method is more profitable to long video sequences having camera movement locally.

• Korean Journal of Childcare and Education
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• v.9 no.5
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• pp.407-436
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• 2013

This study, based on understanding the play features of the participants, explores early children's peer-relation strategies of maintaining and altering play frame and understanding the meaning of the strategies. Free play of 5-year-old children's was observed. The child-care center was visited 1 or 2 days a week, from March to October, 2012. The data collected were based from field notes, interviews with participants, their workbooks and more. The participants used strategies such as 'refusing', 'incapacitating', 'interpreting in a way to sympathize', and 'changing the rules of play' to maintain the play, whilst 'tell-on', 'being on the same side', 'accepting 3rd party' features were used to alter play frame. Participants using these various play-frame strategies experienced life implications of 'dialectic of exclusion and selection' and 'quiver of boundary'. This study, specifying efforts of the children to maintain and alter the play frame, will provide an understanding of perception of "social exclusion" to children, which has been viewed negatively in the past. It will also benefit on-site teachers in helping them understand peer-relationship within children and provide a more in-depth intervention for peer-relationship issues.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.4
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• pp.17-27
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• 2014

Wind power which is one of renewable energies is higher economical efficiency and technical maturity than other renewable energies. Recently, the government of ROK announced to increase the proportion of renewable energy through the National Energy Plan. Also, industry required to deregulate for large-scale wind power as Renewable Portfolio Standard (RPS) is introduced. Wind power whereas the eco-friendly energy, is a serious level of damage of the natural environment and topography when the wind power is located. Therefore, the study selected the indicators required for site selection of wind power and proposed the feasible area for wind power based on wind resource map. We selected the 15 indicators including 12 legal protected area, Ecology and Nature Map, rarity, and connectivity (National Ecological Network). After site selection, we should be considered slope and altitude at the stage of design for wind farm to mitigate the environmental impact. Results of analysis showed that 22.3% of wind resource map is available to locate wind power in real. Through the field survey we had verified the accuracy of the results was significantly correct.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.589-596
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• 2019

With the proliferation of intelligent transportation system (ITS) with dedicated short-range communication (DSRC) deployment, there are various applications requiring different throughput and reliability performance. To meet the enhanced throughput requirements in newly generated applications, IEEE 802.11bd is proposed to standardize for support of enhanced throughput and latency, preserving the fairness with previously deployed WLAN V2X devices. One of the main features of IEEE 802.11 bd is 20 MHz transmission to support the high data rate. In this paper, the primary channel selection method is proposed to guarantee the fairness with frame transmissions with 10 MHz bandwith including communications in WLAN V2X devices deployed with IEEE 802.11p. Simulation shows that the proposed channel access method for 20 MHz transmission with primary selection preserves the fairness without the change of channel access method in wide-band transmission.

• Journal of Broadcast Engineering
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• v.15 no.5
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• pp.672-680
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• 2010

This paper presents an adaptive quantization matrix selection scheme for H.264 video encoding. Conventional H.264 coding standard applies the same quantization matrix to the entire video sequence without considering local characteristics in each frame. In this paper, we propose block adaptive selection of quantization matrix according to edge directivity of each block. Firstly, edge directivity of each block is determined using intra prediction modes of its spatially adjacent blocks. If the block is decided as a directional block, new weighted quantization matrix is applied to the block. Otherwise, conventional quantization matrix is used for quantization of the non-directional block. Since the proposed weighted quantization is designed based on statistical distribution of transform coefficients in accordance with intra prediction modes, we can achieve high coding efficiency. Experimental results show that the proposed scheme can improve coding efficiency by about 2% in terms of BD bit-rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5A
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• pp.325-338
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• 2012

In this paper, a radio resource allocation scheme for a multi-hop relay transmission in cognitive radio (CR) system is proposed to support the employment of relay nodes in IEEE 802.22 standard for wireless regional area network (WRAN). An optimization problem is formulated to maximize the number of serving secondary users (SUs) under system constraints such as time-divided frame structure for multiplexing and a single resource-unit to every relay-hop. However, due to mathematical complexity, the optimization problem is solved with a sub-optimal manner instead, which takes three steps in the order of user selection, relay/path selection, and frequency selection. In the numerical analysis, this proposed solution is evaluated in terms of service rate denoting as the ratio of the number of serving SUs to the number of service-requesting SUs. Simulation results show the condition of adopting multi-hop relay and the optimum number of relaying hops by comparing with the performance of 1-hop system.