• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.11a
• /
• pp.51-55
• /
• 2005

터널은 밝기가 급변하는 장소로서 자동차 운전자가 터널 진입 시 도로의 상황이나 교통상황을 정확히 파악하여 안전하고 불안감 없이 도로를 통행 할 수 있게 하여야 한다. 터널내의 충분한 노면휘도 유지를 위하여 터널내부의 조도를 정기적으로 측정하여야 하는데 기존의 수동식 측정법으로는 신속하고 신뢰적인 조도측정에 한계가 있다. 따라서 본 논문에서는 차량을 이용한 터널조도 및 휘도 측정시스템 개발과 함께 운용타당성에 대한 결과를 외국 사례와 함께 터널 실험을 통하여 결론을 도출하였다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.11a
• /
• pp.195-199
• /
• 2005

우리나라는 국토의 65% 이상이 산악지대로서 일반도로, 고속도로, 산업도로에서 터널이 차지하는 비중이 점차 증대되어지고 있다. 터널은 밝기가 급변하는 장소로서 자동차 운전자가 터널 진입 시 도로의 상황이나 교통상황을 정확히 파악하여 안전하고 불안감 없이 도로를 통행 할 수 있게 하여야 한다. 터널내의 충분한 노면휘도 유지를 위하여 터널내부의 조도를 정기적으로 측정하여야 하는데 기존의 수동식 측정법으로는 신속하고 신뢰적인 조도측정에 한계가 있다. 따라서 본 논문에서는 차량을 이용한 측정시스템을 이용하여 터널조도 및 휘도를 측정하고 그 실측값을 분석하였다.

• The Journal of Korea Robotics Society
• /
• v.12 no.1
• /
• pp.11-18
• /
• 2017

Static balance of an articulated robot arm at various configurations requires a torque compensating for the gravitational torque of each joint due to the robot mass. Such compensation torque can be provided by a spring-based counterbalance mechanism. However, simple installation of a counterbalance mechanism at each pitch joint does not work because the gravitational torque at each joint is dependent on other joints. In this paper, a 6 DOF industrial robot arm based on the parallelogram for multi-DOF counterbalancing is proposed to cope with this problem. Two passive counterbalance mechanisms are applied to pitch joints, which reduces the required torque at each joint by compensating the gravitational torque. The performance of this mechanism is evaluated experimentally.

• Proceedings of the KAIS Fall Conference
• /
• 2007.11a
• /
• pp.181-184
• /
• 2007

본 논문에서는 수경재배의 비중이 늘어난 만큼 새로운 친환경 저자 정밀 급액관리의 개발이 시급함을 언급하고 현재의 한계를 극복 할 수 있는 배액 제어법을 개발 하고자 한다. 급액관리 임베디드 시스템은 정확한 시간 제어, 일사량 제어 전자 방식으로서 수동식 배액 제어법의 문제점을 해결할 수 있으며 뿐만 아니라 사용자가 온실의 없을 경우에도 급액관리를 할 수 있도록 web기반으로 구현하여 편의를 도모하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.2
• /
• pp.324-332
• /
• 2007

In this paper, we developed remote control devices that can be controlled passive component e.g. resistor, inductor, capacitor that is a basic element in the electric circuit. We embodied a remote laboratory for basic circuit theory which learners can experiment controlling element value to remote through the internet. It was seen that is useful applying passive component developing to a remote laboratory. Because developed passive components can response in an experiment altering several element values to remote, they will be used very usefully in a remote experiment that equip various experiment theme. Therefor the proposed laboratory will be solved problems of virtual laboratory which students do not handle instruments in engineering experiment. With our proposed system, students can experiment any time, anywhere.

• The Journal of the Acoustical Society of Korea
• /
• v.38 no.2
• /
• pp.145-153
• /
• 2019

Adaptive beamforming methods are known to suppress sidelobes and improve detection performance of weak signal by constructing weight vectors depending on the received signal itself. A standard adaptive beamforming like the MVDR (Minimum Variance Distortionless Response) is very sensitive to mismatches between weight vectors and actual signal steering vectors. Also, a large computational complexity for estimating a stable covariance matrix is required when wideband beamforming for a large-scale array is used. In this paper, we exploit the WBRCB (Wideband Robust Capon Beamforming) method for stable and robust wideband adaptive beamforming of a passive large uniform line array sonar. To improve robustness of adaptive beamforming performance in the presence of mismatches, we extract a optimum mismatch parameter. WBRCB with extracted mismatch parameter shows performance improvement in beamforming using synthetic and experimental passive sonar signals.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.2
• /
• pp.10-18
• /
• 2008

This paper presents the design and imelementation of an electronic ballast with a passive PFC structure from which acoustic resonance of the metal halide lamp was removed by introducing the frequency modulation(FM) method. The proposed ballast consists of an EMI filter, passive PFC circuit full-bridge inverter, LC resonance type igniter and a circuit for removing acoustic resonance. The FM method solved two problems associated with single frequency driving: variation of the acoustic resonance range according to lamp aging and the acoustic resonance range discrepancy caused by different materials sealed inside the arc tube and their pressures for arc tubes of identical sizes from different manufacturers. Performance of the prototype developed for this study of the electronic ballast for 1[kW] metal halide lamp was verified by evaluating its optical conversion efficiency, input PF, input current THD and power conversion efficiency.

• Journal of the Korea Society for Simulation
• /
• v.25 no.3
• /
• pp.53-63
• /
• 2016

We consider simulation study combining static and mobile decoys for survivability of a surface warship against torpedo attack. It is assumed that an enemy torpedo is a passive acoustic homing torpedo and detects a target within its maximum target detection range and search beam angle by computing signal excess via passive sonar equation, and a warship conducts an evasive maneuvering with deploying static and mobile decoys simultaneously to counteract a torpedo attack. Suggesting the four different decoy deployment plans to achieve the best plan, we analyze an effectiveness for a warship's survival probability through Monte Carlo simulation, given a certain experimental environment. Furthermore, changing the speed and the source level of decoys, the maximum torpedo detection range of warship, and the maximum target detection range of torpedo, we observe the corresponding survival probabilities, which can provide the operational capabilities of an underwater defense system.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.36 no.4
• /
• pp.677-684
• /
• 2016

In order to improve the nighttime visibility of the lane, the need for the development of the automated line marking equipment is on the rise. The purpose of this study is to suggest performance assessment methodology that can be assessed from various aspects such as productivity, safety and quality performance of line marking equipment and to comprehensively analyze the performance of hand-operated and automated equipment based on field test. The following shows the results. It suggested a methodology capable of analyzing the performance of the line marking equipment in terms of productivity, safety and quality. Automated equipment for line marking was analyzed that can be obtained productivity achievement rate of 156.3% as compared with hand-operated equipment. On the basis of the expert advise and literature review, we derived twelve safety factors and ten quality factors of unit work in line marking. By utilizing the AHP technique, we estimated the importance of safety and quality factors. Automated equipment for line marking was analyzed to have been able to expect safety improvement rate of 49.8% and quality improvement rate of 47.2%. It is expected that the performance assessment methodology suggested in this study will be useful in analyzing objective and quantitative validity and expected effectiveness of the line marking equipment.

• International Journal of Highway Engineering
• /
• v.5 no.1 s.15
• /
• pp.11-18
• /
• 2003

Road roughness, as the key factor influencing not only drivers' ride quality and safety but also pavement deterioration, is one of the most important pavement performance indicator to be evaluated by users' subjective assessment. For this reason, a specific number of the pavement roughness has been adopted to monitor the condition of a road for pavement management systems and to evaluate the quality of newly constructed sections, however, none of the unified methodology was internationally accepted. In Korea highway network, road roughness has been used mainly to evaluate newly placed pavement by using 7.6m CP (California Profile meter) to calculate PrI (Profile Index). But this instrument is manually operated to measure road profiles by traffic closure and their interpretation depends on personal bias. Therefore, problems arisen from the manually operated instrument will be overcome by using the APL (Longitudinal Profile Analyzer) which can be operated in the speed of 80km per hour. A study was conducted to correlate the relation from both concrete and asphalt pavement between IRI (measured by APL) and PrI (measured by 7.6m CP). Test results showed that there was a good correlation between IRI and PrI.