• Journal of Korea Water Resources Association
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• v.36 no.2
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• pp.153-159
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• 2003

When available rainfall data is not sufficient, a rough tendency of I-D-F relationship appeared frequently. In fact, rainfall intensity on the curve shows abnormally higher value the longer rainfall duration is applied that gives rise to great confusion to apply a rainfall I-D-F relationships curve to a practical work, however, the research work will present a way to solve above mentioned problem by the use of the Box-Cox transformation formula for a given rainfall data. The study came to a conclusion that the Box-Cox transformation formula is satisfied to utilize in a practical work on the ground of analysis for rainfall data of Sancheong and Yeongcheon.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.2
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• pp.113-129
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• 2000

This study evaluates the behavior and strength of an anchorage zone of the prestressed concrete box girder bridge on the Kyungboo highway railroad using the 2D SUB-3D STM approach and a linear elastic finite element analysis. The 2D SUB-3D STM approach utilizes several two-dimensional sub strut-tie models that represent the compressive and tensile stress flows of each projected plane of the three-dimensional structural concrete in the selection of a three dimensional strut-tie model, evaluation of the effective strengths of the concrete struts, and verification of the geometric compatibility condition and bearing capacity of the critical nodal zones in the selected three-dimensional strut-tie model. The finite element analysis uses an 8-node brick element and the longitudinal prestressing force is considered as the equivalent nodal force. Analysis results show that the 2D SUB-3D STM approach and linear elastic finite element method can be effectively applied to the analysis and design of three-dimensional structural concrete including a prestressed concrete box girder anchorage zone.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.619-628
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• 2017

As the 3D laser scanning technology capable of databaseing large sewage box culverts becomes possible, it is necessary to develop a standardization manual that can clearly distinguish the structural and operational defect types of box culver and analyze the defect data. In this study, we collected and analyzed defects in sewage box culverts of 14,827m in total by selecting three districts in Korea. The major defects were surface damages, and their defect densities were $2.17m^2/m$, $0.27m^2/m$ and $0.10m^2/m$ for aggregate exposure, Steel reinforcement exposure, and Steel reinforcement projecting. In order to support the decision of the box culverment management, it was divided into five grades and each defect code and defect score were allocated. The results of this study are useful for the diagnosis of the sewage box culverts in Korea and it is expected to support a decision making for management.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.6
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• pp.450-453
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• 2009

The sketch technique is being researched as the method of expressing intentions in 3D virtual space for cooperative work. The annotation which is necessary in 3D virtual space 1) not only enables the quick, easy and intuitive delivery of contents" but 2) must enable the input of sketch even on diverse and complicated surfaces and 3) must be expressed to recognize this in various angles in case of having the significance of 3D. Even if the sketch technique settles the precondition of 1), if 2) and 3) are not considered, the annotation is unable to deliver the contents accurately to the participant of cooperative work. Accordingly, a sketch annotation technique which enables the input of annotation even on complicated surfaces and also considers the contents of 3D is proposed using sketch-box technique.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.4
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• pp.307-311
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• 2004

This paper presents an efficient architecture that optimizes the design of SEED S-box using composite field arithmetic. SEED is the Korean standard 128-bit block cipher algorithm developed by Korea Information Security Agency. The nonlinear function S-box is the most costly operation in terms. of size and power consumption, taking up more than 30% of the entire SEED circuit. Therefore the S-box design can become a crucial factor when implemented in systems where resources are limited such as smart cards. In this paper, we transform elements in $GF(2^8)$ to composite field $GF(((2^2)^2)^2)$ where more efficient computations can be implemented and transform the computed result back to $GF(2^8)$. This technique reduces the S-box portion to 15% and the entire SEED algorithm can be implemented at 8,700 gates using Samsung smart card CMOS technology.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.187-188
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• 2021

본 논문에서는 Openpose의 신뢰도를 이용해 3D pose estimation의 정확도를 높이는 방법을 제안한다. 모델의 앞뒤양옆 네 방향에서 pose estimation의 진행하기 위해 3D 모델에 AABB(Axis Aligned Bound Box)를 생성한 다음, box의 네 옆면으로 모델을 투영시킨다. 각 면에 투사된 2D image에 대해 Openpose 2D pose estimation의 진행한다. 네 면에서 생성한 2D 스켈레톤들의 평균을 통해 3D 상의 교차점을 획득한다. Openpose에서 제공하는 신뢰도(confidence)를 이용하여 잘못 나온 2D 관절을 제외하는 것으로 더 정확한 pose estimation의 수행하였다. 실험적인 방법을 통해 신뢰도 0.45 이상의 값을 가지는 joint 만을 사용해 3D 교차점을 구함으로써 3D pose estimation의 정확도를 높였다.

• Journal of Broadcast Engineering
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• v.14 no.2
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• pp.114-126
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• 2009

In this paper, we propose a PSNR(peak-to-peak signal to noise ratio) estimation method exploiting visual rhythm information for the reconstructed video frames at the customer's STB(Set-top Box). Key idea is that we can estimate the PSNR by using VR(visual rhythm) information even though a VR consists of the pixels in a vertical direction of a 2D(2-dimensional) video frame, because VR is the 1D projected version of a 2D video frame approximately. Simulation results show that the estimated PSNR from VR information is closely related to the PSNR from 2D video frames. The advantages of the proposed scheme includes that it can monitor the video quality efficiently while minimizing the computation load of STB, and show the location, duration and occurrence count of severe picture degradation.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1271-1281
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• 2017

It is essential to collect and analyze target information around the vehicle for autonomous driving of the vehicle. Based on the analysis, environmental information such as location and direction should be analyzed in real time to control the vehicle. In particular, obstruction or cutting of objects in the image must be handled to provide accurate information about the vehicle environment and to facilitate safe operation. In this paper, we propose a method to simultaneously generate 2D and 3D bounding box proposals using LiDAR Edge generated by filtering LiDAR sensor information. We classify the classes of each proposal by connecting them with Region-based Fully-Covolutional Networks (R-FCN), which is an object classifier based on Deep Learning, which uses two-dimensional images as inputs. Each 3D box is rearranged by using the class label and the subcategory information of each class to finally complete the 3D bounding box corresponding to the object. Because 3D bounding boxes are created in 3D space, object information such as space coordinates and object size can be obtained at once, and 2D bounding boxes associated with 3D boxes do not have problems such as occlusion.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.381-386
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• 2004

Because of rapid increase of internet user, numerous popular web sites have been made on the internet but it is hard to find out a systematic technique for the selection of qualified web site in consumer position. Generally, there are black box, white box and gray box viewpoint for evaluating web site. In this paper present evaluation criteria based on AHP(Analysis Hierarchy Process) technique of black box viewpoint for optimal web site selection in consumer position. We considered usability, efficiency, compatibility based on ISO/IEC 9126 for quality measurement of web site and executed practical analysis about web site in internet. This paper show that the proposed selection technique is applicable to optimal web site selection.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.131-139
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• 2023

In this study, we are purposed to find the educational effect of practical training using a 3D printed structure-based blind box on multidimensional radiographic image interpretation. The subjects were 83 (male: 49, female: 34) 2nd year radiological science students who participated in the digital medical imaging practice that was conducted for 3 years from 2020 to 2022. The learning method used 3D printing technology to print out the inside structure of the blind box designed by itself. After taking X-rays 3 times (x, y, z axis), the structure images in the blind box were analyzed for each small group. We made the 3D structure that was self-made with clay based on our 2D radiographic images. After taking X-rays of the 3D structure, it was compared whether it matches the structural image of the blind box. The educational effect for the practical training surveyed class faithfulness, radiographic image interpretation ability (attenuation concept, contrast concept, windowing concept, 3-dimensional reading ability), class satisfaction (interest, external recommendation, immersion) on a 5-point Likert scale as an anonymous student self-writing method. As a result, all evaluation items had high positive effects without significant differences between males and females. Practical education using blind boxes is a meaningful example of radiology education technology using 3D printing technology, and it is expected to be used as content to improve students' problem-solving skills and increase satisfaction with major subjects.