• Korean Journal of Computational Design and Engineering
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• v.15 no.6
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• pp.460-466
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• 2010

These days, it is getting important to have more chances to visit natural environment for the wellbeing life. The advancement of digital technologies allows us to get useful information regardless of time and location. In this paper, we investigate a way of improving user experience in the natural green environment using the digital technologies. This paper proposes a system called Green-UX-Story which supports users to create and share their story through the online and offline green experience. The system consists of two main systems: the "Story-Field" and the "Story-Tree". The Story-Field consists of a certain number of the Story-Trees allocated to a certain green site. In the Story-Field, users can see the Story-Trees that are owned by other users and share their stories. The Story-Tree contains the user-story in each branch and green information that are captured by the user on the web. The Story-Tree is generated using the L-system algorithm as the user adds stories. The main purpose of the system is to enable users to write their green stories from the both online and offline experiences. This paper describes the system configuration and the user scenario of the Green-UX-story.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.243-248
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• 2015

Recognition model is not defined when you configure a model, Been added to the model after model building awareness, Model a model of the clustering due to lack of recognition models are generated by modeling is causes the degradation of the recognition rate. In order to improve decision tree state tying modeling using parameter estimation of Bayesian method. The parameter estimation method is proposed Bayesian method to navigate through the model from the results of the decision tree based on the tying state according to the maximum probability method to determine the recognition model. According to our experiments on the simulation data generated by adding noise to clean speech, the proposed clustering method error rate reduction of 1.29% compared with baseline model, which is slightly better performance than the existing approach.

• Nuclear Engineering and Technology
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• v.40 no.5
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• pp.397-408
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• 2008

This paper describes the application of a software fault tree analysis (FTA) as one of the analysis techniques for a software safety analysis (SSA) at the design phase and its analysis results for the safety-critical software of a digital reactor protection system, which is called the KNICS RPS, being developed in the KNICS (Korea Nuclear Instrumentation & Control Systems) project. The software modules in the design description were represented by function blocks (FBs), and the software FTA was performed based on the well-defined fault tree templates for the FBs. The SSA, which is part of the verification and validation (V&V) activities, was activated at each phase of the software lifecycle for the KNICS RPS. At the design phase, the software HAZOP (Hazard and Operability) and the software FTA were employed in the SSA in such a way that the software HAZOP was performed first and then the software FTA was applied. The software FTA was applied to some critical modules selected from the software HAZOP analysis.

• Journal of the Korea Furniture Society
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• v.22 no.4
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• pp.270-277
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• 2011

This study aims to find new solutions to the problem of utilization of materials and techniques represented in the development of modern lighting design. LED is an important component in modern lighting design and pine tree is one of the most popular domestic wood in furniture design in Korea. In this study, design is developed into various types of furniture such as a table, a chest, and a lighting, by researching manufacturing process and examining the use of slicing pine tree. The technique of slicing pine tree is a simple linear arrangement that was traditionally used in wooden furniture in Lee dynasty, with an emphasis on repetitive rhythm. The slicing technology is used to expand the usage of domestic pine tree. The beauty of natural wood is expressed with the transmission of light by applying this technique to the lighting design. It also brings new communication in between artificial lighting and natural wood combining this traditional technique and LED lighting in design. Finally, this study suggests particular value through the convergence of analog and digital by using the traditional wooden technique that keeps natural wood prints and new digital technology by using LED lighting. More discussions and research about this subject are expected continuously through this study.

• Journal of Electrical Engineering and Technology
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• v.4 no.4
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• pp.552-558
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• 2009

We proposed a semi-blind digital image watermarking technique for copyright protection. The proposed algorithm embedded a binary sequence watermark into significant wavelet coefficients by using a quantization method. The main idea of the quantization method was to quantize a middle coefficient of the triplet of a significant wavelet coefficient according to the watermark's value. Unlike an existing algorithm, which used a random location table to find a coefficient in which the watermark bit will be embedded: the proposed algorithm used quad-tree decomposition to find a significant wavelet coefficient for embedding. For watermark detection, an original host image was not required. Thanks to the usage of significant wavelet coefficients, the proposed algorithm improved the correlation value, up to 0.43, in comparison with the existing algorithm.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1478-1483
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• 2008

In this paper, a digital watermarking method using the WPT (Wavelet Packet Transform) is proposed. The proposed algorithm transforms the input image by using the WPT and inserts the watermark by using the quad-tree algorithm and Cox's algorithm. The experiments for evaluating the performances of the proposed algorithm is carried out by inserting a watermark in each wavelet packet transform step and by inserting a watermark into the lowest frequency domain (LL). As a simulation result, the performance of the insertion of the watermark into the 6 levels of WPT is better than that of other cases. In addition, about $30{\sim}60%$ of all watermarks are inserted into the LL band, the correlation value is improved though the PSNR performance decreases $1{\sim}2dB$.

• Spatial Information Research
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• v.15 no.2
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• pp.181-187
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• 2007

To make digital terrain data, automatic correlation matching by stereo airborne/satellite images has been researched. The result of automatic correlation matching has a limit on extracting exact ground height because of angle of sensor, tree of height. Therefore, the amount of editing works depend on the distribution of spatial feature in images as well as image quality. This paper shows that the automatic correlation matching result was affected by density and height of tree.

• Journal of Environmental Impact Assessment
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• v.17 no.5
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• pp.279-288
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• 2008

Vertical forest distribution is one of the important factors to understand various ecological mechanism such as succession, disturbance and environmental effects. LiDAR data provide information, both the horizontal and vertical distribution of forest structure. The laser scanner survey provided a point cloud, in which the x, y, and z coordinates of the points are known. The objectives of this study were 1) to analyze factors of forest structure such as individual tree isolation, tree height, canopy closure and tree density using LiDAR data and 2) to compare the forest structure between outer and interior forest. The paper conducted to extract the individual tree using watershed algorithm and to interpolate using the first return of LiDAR data for yielding digital surface model (DSM). The results of the study show characters of edge such as more isolated individual trees, higher density, lower canopy closure, and lower tree height than those of interior forest. LiDAR data is to be useful for analyzing of forest structure. Further study should be undertaken with species for more accurate results.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.310-319
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• 2010

In this paper, digital watermarking method using wavelet transform and quad-tree algorithm is proposed. The proposed algorithm transforms the input image by DWT(Discrete Wavelet Transform) and AWPT(Adaptive Wavelet Packet Transform), inserts the watermark by quad-tree algorithm and the Cox's algorithm. The simulation for performance analysis of the proposed algorithm is implemented about the effect of embedding watermark in each subband coefficient (HH, LH, HL) of DWT, each DWT level, and each AWPT level. The simulation result by using DWT is compared with that using AWPT in the proposed algorithm. In addition, the effect of embedding watermark in the lowest frequency band (LL) is simulated. As a simulation result using DWT, the watermarking performance of simultaneously embedding in HH, LH, and HL band of DWT(6 level) is better than that of different cases. The result of AWPT(3 level) improves the correlation value compared to that of DWT(3 level). In addition, insertion the watermark to the LL band about 30~60% of all watermarks improves the correlation value while PSNR performance decreases 1~2dB.

• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1165-1172
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• 2023

Recently, Korea has declared carbon neutrality by 2050. The Korea Forest Service is promoting the precision and high technology of forest resource surveys. As such, the demand for forest resource management is increasing, and the need to build a digital twin of forest space is increasing. However, to date, digital twin has only built and provided virtual city services, which are city and nationwide digital twin environments. Three-dimensional digital twin services targeting forest space are not operated and provided. Therefore, in this study, we aimed to implement a forest digital twin environment to provide 3D forest spatial information services corresponding to vertical information such as tree-level height and thorax diameter. By lightweighting realistic 3D tree models and applying 3D Tiles, we confirmed the feasibility of implementing a forest digital twin environment for 3D forest spatial information services. Through continuous research, we plan to implement a forest digital twin that can deploy and service 3D tree models for trees nationwide, including street trees in urban areas. This is expected to enable the development of forest digital twin services for forest resource management.