• Journal of Korean Society of Transportation
• /
• v.27 no.1
• /
• pp.169-177
• /
• 2009

In this paper, the rotated hexagonal lattice model (RHLM) was proposed, which is applied to pedestrian flow, and developed the simulation model for the pedestrian counterflow. RHLM is an upgrade version of the square lattice model(SLM) and hexagonal lattice model(HLM). The simulation was performed at the hexagonal lattice $20{\times}20$ and evaluated by different speed, density and flow conditions. Simulation results are compared with SLM and show that RHLM can replicate the characteristics of pedestrian traffic more effectively and reliably than any other existing models from several perspectives. First, RHLM can explain the shortest-path movement of pedestrians and more realistic avoidance motion. If they cannot move straight direction, they can move shorter distance from previous position to destination. Second, RHLM reflects the characteristics that the pedestrian can move with higher capacity and the speed of pedestrian flow is hard to zero.

• Journal of the Korean Vacuum Society
• /
• v.15 no.5
• /
• pp.512-517
• /
• 2006

A reliable linear translation system was constructed. The system has six piezo legs, attached to a main body, holding a hexagonal sapphire rod. The sapphire rod moves either forward or backward with the sequential motion of the piezo legs, driven by characteristic electric voltage waves. The translational system was tested in vertical direction. The speed of the sapphire rod was turned out to be constant during several mm travel. The slowest upward speed was measured to be ${\sim}1.7{\times}10^{-6}m/s$, yielding ${\sim}28.3nm/step$, while the slowest upward speed was ${\sim}3.7{\times}10^{-6}m/s$, with ${\sim}61.7nm/step$, due to gravitational force. The velocity increases linearly, as the amplitude of the voltage waves increases. The linear translation system will be used as a coarse approach part for a scanning tunneling microscope.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.7
• /
• pp.99-108
• /
• 2008

For video compression, we have to consider two performance factors that are the search speed and coded video's quality. In this paper, we propose an enhanced fast block matching algorithm using the spatial correlation of the video sequence and the center-biased characteristic of motion vectors(MV). The proposed algorithm first finds a predicted motion vector from the adjacent macro blocks of the current frame and determines an exact motion vector using the cross pattern and a flat hexagon search pattern. From the performance evaluations, we can see that our algorithm outperforms both the hexagon-based search(HEXBS) and the cross-hexagon search(CHS) algorithms in terms of the search speed and coded video's quality. Using our algorithm, we can improve the search speed by up to 31%, and also increase the PSNR(Peak Signal Noise Ratio) by at most 0.5 dB, thereby improving the video quality.

• Journal of the Korean GEO-environmental Society
• /
• v.15 no.11
• /
• pp.53-59
• /
• 2014

It has been generally recognized that the conventional rockfall protection nets have several problems to actual field application in the aspect of shock absorption, lack of pullout bearing capacities, and net damages. Because of the recognition, authors have tried to develop a new rockfall protection system consisted of shock absorption parts and hexagonal net configuration. In the previous research by the authors, the performance of the newly developed rockfall protection system has been investigated through the laboratory tests and the full-scale testing. In this study, subsequently, numerical analysis program is organized to make a confirmation of the structural stability and performance. For the correct design procedure of the hexagonal net system, it is essential to understand the various mechanical behavior of the entire system. It is also important to be reproduced the systematic characteristics of the system acquired by laboratory and full-scale testing by numerical analysis in order to carry out the numerical experiment to understand various mechanical behavior of the system. As a conclusion, the hexagonal net has better performance in mechanical and physical behavior compared with that of the rectangular net. Furthermore, due to the hexagonal net shows a good performance in aspect of the load distribution, it gives a good alternative in long-term management of the rockfall protection net.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.645-648
• /
• 2002

본 논문에서는 비디오 압축에 이용되는 블록 기반 움직임 예측을 위하여 육각 패턴을 이용한 블록 정합 알고리즘을 제안한다. 제안하는 알고리즘은 기존의 3$\times$3 패턴을 이용한 BBGDS 알고리즘과 유사하게 계산 속도의 향상과 더불어 좀 더 강인한 움직임 예측을 할 수 있도록 패턴을 설계하였다. 제안하는 알고리즘을 바탕으로 적은 양의 탐색점(Search Point)을 이용하면서 확장된 탐색 영역(Search Area)을 이용할 수 있다. 제안한 알고리즘의 성능과 계산 속도의 향상이 실험 결과로 보여 진다.

• The Journal of the Acoustical Society of Korea
• /
• v.8 no.4
• /
• pp.5-12
• /
• 1989

In the clinical application of ultrasonic hyperthermia, selective heating of tumor is essential and thus precise control of ultrasonic intensity in both tumor and normal tissue is needed. In this paper, a hexagonal array transducer for ultrasonic hyperthermia is designed and manufactured of which focal point and focal region can be ocntrolled by the digital phase control circuit proposed by authors. Profiles of the focussed ultrasound beam in water and those of temperature in phantom were determined. The experimental and computed results are in good agreement.

• The Journal of Korean Academy of Prosthodontics
• /
• v.56 no.2
• /
• pp.114-119
• /
• 2018

Purpose: Patients who treated implant immediate loading within a week after implant placement at Wonkwang University Dental Hospital Implant Center were evaluated marginal bone resorption. These retrospective analyses are intended to reinforce the clinical evidence for the implant immediate loading. Materials and methods: Medical history and radiographic data were investigated, which were the patients' who treated implant immediate loading and restoration with provisional prostheses between January 2005 and June 2016, at Wonkwang University Dental Hospital Implant Center. Total number of implants was 70, marginal bone resorption was measured according to implant length, diameter and connection type. To measure marginal bone resorption, periapical radiographs were taken when the implants were placed and after 6 month. Statistical analysis was done in Mann-whitney U test and Kruskal-wallis test with SPSS 22.0 software (P<.05). Results: Mean marginal bone resorption around immediately loaded implants according to implant connection type was shown $1.24{\pm}0.72mm$ in internal hexagon connection type and $1.73{\pm}1.27mm$ in external hexagon connection type. There was no statically significant difference in marginal bone resorption with implant length and diameter. Conclusion: Implants with immediated loading in internal hexagon connection type showed less marginal bone resorption significantly than in external hexagon connection type.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.2
• /
• pp.387-395
• /
• 2020

The standard model of Korean pavilions can embody the beauty of the Korean traditional and reflect the trend of the times, develop a universal and realistic model, and at the same time promote Korean traditional beauty internationally. Therefore, the purpose of this study is to develop a standard model for living, industrializing, activating and globalizing Korean traditional pavilions while inheriting our own traditional technologies and preserving the legitimacy of Korean pavilions through a case study of Korean traditional pavilions. Considering the case analysis and modern trends, the plan was carried out in each part to present standard models for the representative types of traditional pavilion, Samojeong, Yukgakjeong, and Palgakjeong. The standard model has made some changes in design trends, including the installation of handrails and handrails to enhance utilization while considering legitimacy. The standard model presented in this way reflects the current design trend and can be changed in different forms depending on the trend at that time. The standard model of Korean pavilions developed this time can be said to be a universal and realistic model, while reproducing the beauty of Korean tradition.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.7A
• /
• pp.828-835
• /
• 2004

An adaptive hexagon based search(AHBS) algorithm is proposed in this paper to perform block motion estimation in video coding. The AHBS evaluates the value of a given objective function starting from a diamond-shaped checking block and then continues its process using two hexagon-shaped checking blocks until the minimum value is found at the center of checking blocks. Also, the determination of which checking block is used depends on the position of minimum value occurred in previous searching step. The AHBS is compared with other fast searching algorithms including full search(FS). Experimental results show that the proposed algorithm provides competitive performance with slightly reduced computational complexity.

• Journal of IKEEE
• /
• v.26 no.1
• /
• pp.129-132
• /
• 2022

In this paper, a technique for optimizing the sub-array system structure that can minimize the side lobe level of the phased-array antenna is proposed. Optimization of the proposed array antenna structure is to adjust the spacing between sub-arrays and sub-arrays by using a hexagonal array structure of one sub-array and a hexagonal sub-array for six hexagonal arrays, and thus the entire phased array antenna system of the radiation pattern was optimized. Compared to the 2-dimensional planar antenna system, the proposed technique maintains a gain of 24.3 dBi and a half-power beam-width of 8.46 degrees without change, and only reduces -3.4 dB and -6.5 dB in the x-axis and y-axis directions, respectively.