• Structural Engineering and Mechanics
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• 제43권3호
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• pp.395-410
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• 2012

The visualizing energy flow and control in vibrating stiffened plates with a cutout are studied using finite element method. The vibration intensity, vibration energy and strain energy distribution of stiffened plates with cutout at different excitation frequencies are calculated respectively and visualized for the various cases. The cases of different size and boundaries conditions of cutouts are also investigated. It is found that the cutout or opening completely changes the paths and distributions of the energy flow in stiffened plate. The magnitude of energy flow is significantly larger at the edges near the cutout boundary. The position of maximum strain energy distribution is not corresponding to the position of maximum vibrational energy. Furthermore, the energy-based control using constrained damping layer (CDL) for vibration suppression is also analyzed. According to the energy distribution maps, the CDL patches are applied to the locations that have higher energy distribution at the targeted mode of vibration. The energy-based CDL treatments have produced significant attenuation of the vibration energy and strain energy. The present energy visualization technique and energy-based CDL treatments can be extended to the vibration control of vehicles structures.

• Journal of Mechanical Science and Technology
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• 제17권12호
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• pp.2053-2065
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• 2003

The current trend in automotive finishing industry is to use more electrostatic rotating bell (ESRB) need space to their higher transfer efficiency. The flow physics related with the transfer efficiency is strongly influenced by operating parameters. In order to improve their high transfer efficiency without compromising the coating quality, a better understanding is necessary to the ESRB application of metallic basecoat painting for the automobile exterior. This paper presents the results from experimental investigation of the ESRB spray to apply water-borne painting. The visualization, the droplet size, and velocity measurements of the spray flow were conducted under the operating conditions such as liquid flow rate, shaping airflow rate, bell rotational speed, and electrostatic voltage setting. The optical techniques used in here were a microscopic and light sheet visualization by a copper vapor laser, and a phase Doppler particle analyzer (PDPA) system. Water was used as paint surrogate for simplicity. The results show that the bell rotating speed is the most important influencing parameter for atomization processes. Liquid flow rate and shaping airflow rate significantly influence the spray structure. Based on the microscopic visualization, the atomization process occurs in ligament breakup mode, which is one of three atomization modes in rotating atomizer. In the spray transport zone, droplets tend to distribute according to size with the larger drops on the outer periphery of spray. In addition, the results of present study provide detailed information on the paint spray structure and transfer processes.

• 한국주조공학회지
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• 제42권6호
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• pp.347-357
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• 2022

본 연구에서는 주조공장의 장입재 충전 거동을 3차원적으로 시각화하고자 하였다. 장입재와 용해로의 실제 조건을 반영하여 시뮬레이션하였다. 3차원 시각화 시뮬레이션이 제조 현장의 장입재 충전 거동을 사실적으로 잘 구현하는지 확인하였다. 3차원 시각화 시뮬레이션에 의한 현실적인 충전 상태를 이상적인 충전 상태와 비교하였다. 어떤 경우에 두 충전 상태의 차이가 발생하는지 분석하였다. 3차원 시각화 시뮬레이션을 제조 공정에 적용할 경우의 특징을 살펴보았고, 주조 분야에서의 여러 활용 방안을 제안하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.137.3-137
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• 2001

Many locomotion purpose robots are being built and are under research such as mobile manipulator and biped humanoid robot, etc. Dynamic posture stability of these robots is based on the ZMP point. For getting stable ZMP trajectory, some method has been developed but is too complex and time consuming which leads to inability in generating on-line ZMP trajectory. In this paper, we give a qualitative study about behavior of ZMP in biped walking robot through visualization. This result gives intuitive understanding about behavior of ZMP under various robot state.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.484-492
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• 2011

Power system analyses, which involve the handling of massive data volumes, necessitate the use of effective visualization methods to facilitate analysis and assist the user in obtaining a clear understanding of the present state of the system. This paper introduces an interface that compensates for the limitations of the visualization modules of dynamic security assessment tools, such as PSS/e and TSAT, for power system variables including generator rotor angle and frequency. The compensation is made possible through the automatic provision of dynamic simulation data in visualized and tabular form for better data intuition, thereby considerably reducing the redundant manual operation and time required for data analysis. The interface also determines whether the generators are stable through a generator instability algorithm that scans simulation data and checks for an increase in swing or divergence. The proposed visualization methods are applied to the dynamic simulation results for contingencies in the Korean Electric Power Corporation system, and have been tested by power system researchers to verify the effectiveness of the data visualization interface.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.9-17
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• 2001

This paper is the second of 3 companion papers which investigate axial stratification process. In-cylinder fuel behavior has been investigated in the port injected Sl engine by visualizing for the purpose of understanding stratification. Planar laser light sheet from an Nd:YAG laser has been illuminated through the transparent quartz cylinder of the single cylinder optical engine and the Mie scattered light has been captured through the quartz window in the piston head with an ICCD camera. Fuel has been replaced with an air-ethanol mixture to utilize atomized fuel spray fur the visualization purposes. This results have been compared with steady flow concentration measurement. For low/medium swirl port, the early injection makes such a fuel distribution state that is upper-rich, middle-lean and lower-rich along the combustion chamber and cylinder by tumbling motion. On the other hand, the late injection induces upper-rich, middle-lean and lower-rich state due to the short fuel penetration.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.224-228
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• 2005

동적 감쇠자로서 백홀에 대한 동적 제어 테스트를 수행하였다. 공급라인에서 압력 섭동에 의해 발생되는 가진과 스월 인젝터의 내부 파동 분석을 위해 수력학적 진동발생기와 1차원 가시화 모델 인젝터가 제작되었다. 음향학적 대신에 동적 감쇠자로서 백홀의 영향에 초점을 두었기 때문에 액막의 분열길이와 액막 두께를 측정하여 정상 상태와 가진 상태의 결과를 비교하였다.

• 조명전기설비학회논문지
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• 제23권3호
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• pp.38-44
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• 2009

This paper presents a new windows application based on 3-D graphics and Text-To-Speech (TTS) for effective management of substation equipment. When problems in a power system occur, inexperienced power system operators may have difficulty in understanding the situation as well as finding suitable countermeasures quickly. This paper addresses an effective scheme to visualizing power system equipment under normal and abnormal conditions using 3-D graphics and animations. In addition, the state variations and the order of maintenance priority of substation equipment are represented by TTS and intuitive methods. The proposed system can help power system operators to more quickly understand the state of power system equipment, and it can provide operators with the suitable countermeasures for minimizing damage caused by equipment problems.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.24-31
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• 1999

The MPI engine becomes increasingly popular because it meets two requirements of stringent pollutant emission and the lower fuel consumption. Even though supplies the same amount of fuel to each cylinder , it is hard to precisely control the air-duel ration due to the different amount of air flowing into each cylinder. The uniformity of air-fuel ration in each cylinder is considerably affected by the plenum chamber configuration . This study is focused on experimentally analyzing the flow characteristics within the plenum chamber In the present experiment , steady and valve dynamic state flow tests are performed and the flow field inside the plenum chamber is visualized and measured by utilizing a laser sheet visualization technique and a PTV method. These measured results indicate that the flow structure in the plenum chamber is highly influenced by the plenum chamber configurations, suction flow rates, crank speeds and so on.

• 한국항공운항학회지
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• 제29권2호
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• pp.84-93
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• 2021

Airline schedule is the most basic data for flight operations and has significant importance to an airline's management. It is crucial to know the airline's current schedule status in order to effectively manage the company and to be prepared for abnormal situations. In this study, machine learning techniques were applied to actual schedule data to examine the possibility of whether the airline's fleet state could be artificially learned without prior information. Given that the schedule is in categorical form, One Hot Encoding was applied and t-SNE was used to reduce the dimension of the data and visualize them to gain insights into the airline's overall fleet status. Interesting results were discovered from the experiments where the initial findings are expected to contribute to the fields of airline schedule health monitoring, anomaly detection, and disruption management.