• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.10
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• pp.1361-1368
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• 2020

The system for counting the number of people has traditionally been implemented in various ways. Existing systems include infrared sensors, lasers, cameras, etc. In the case of such an existing system, there are restrictions on space such as ceilings and sides of walls. In this paper, we propose a method of detecting the footsteps of pedestrians using a piezoelectric mat containing a number of piezoelectric sensors and counting the number of pedestrians passing simultaneously by using the data collected from the piezoelectric mat. When pedestrians pass over piezoelectric mats, the collected sensor data was aggregated using SPI communication and transmitted to PC server using TCP/IP communication. Performance analysis shows that approximately 600 step data can be recognized with 99% accuracy. This is to overcome the shortcomings of other counting systems.

• Proceedings of the KSRS Conference
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• v.2
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• pp.943-945
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• 2006

The experiment on study of ambient nose generated by large-amplitude internal waves in Luzon Strait is analyzed. Simultaneous observations of internal waves and characteristics of ambient noise generated by them were carried out. Fast 50-m solitary internal wave propagated to the northwest direction with speed more than 3 m/s was observed. It was revealed an enhancing of ambient noise level (at frequency range 1-2 kHz) at a time of passing the face side of the solitary wave.

• Analytical Science and Technology
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• v.15 no.3
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• pp.256-262
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• 2002

After porous filters were manufactured using cordierite powder whose mean paricle size was 200${\mu}m$, they were loaded with catalysts such as $V_2O_5$, CuO and $LaCoO_3$ by vacuum impregnation method. And the NOx/SOx simultaneous removal efficiency was measured by passing NO and $SO_2$ through catalyst-loaded ceramic filters. The cordierite porous filters had the apparent porosity of 61.6%, the compressive strength of 12.3 MPa and the pressure drop of 147 pa at the face velocity of 5 cm/sec. According to the analysis of NO/$SO_2$ simultaneous removal efficiency, perovskite $LaCoO_3$ catalyst was the most efficient for the simultaneous NO and $SO_2$ removal. The $LaCoO_3$ catalyst-loaded filter could remove more than 90% for NO and more than 80% for $SO_2$.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.123-132
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• 2011

The purpose of this study is to calculate and propose rational multi-lane loading factors for bridge design considering the probability of simultaneous truck passing in adjacent lanes and real truck weights. The probability of simultaneous truck passing is calculated by analyzing video image taken at various locations in highways and national roads. Weigh-In-Motion system data at two locations are used, which is combined with the probability of multiple presence to calculate the multi-lane loading factors for typical 2 lane and 5 lane bridges. Statistical properties of multi-lane loading factors are also calculated assuming that locations for video images and WIM data represent the overall traffic condition in the country. Results are compared with various design codes in the world and they show that the values are between the current Korea Bridge Design Code and AASHTO LRFD specification or Eurocode and are similar to Canadian Code.

• Journal of Korean Society of Steel Construction
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• v.12 no.2 s.45
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• pp.151-165
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• 2000

Since vehicles become large and heavy and traffic volume is increased rapidly, many fatigue damages have been reported in bridge members. In order to prevent fatigue damages of bridge members and maintain safety it is essential to perform rational fatigue check. Only one vehicle is loaded on a bridge deck for the fatigue design. But in reality it is seldom that only one vehicle passes on a bridge deck. Usually more than two vehicles are passing on a bridge deck simultaneously. Therefore, it is necessary to consider the influence of simultaneous loading for a rational fatigue design. In this study, the influence of simultaneous loading is investigated by performing stress variation analysis due to vehicle load on the basis of linear superposition method and Monte-Carlo simulation of traffic flow, and then calculating the measure of fatigue damages.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.339-346
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• 2006

Increased usage of autonomous underwater vehicle (AUV) has led to the development of alternative navigational methods that do not employ the acoustic beacons and dead reckoning sensors. This paper describes a simultaneous localization and mapping (SLAM) scheme that uses range sonars mounted on a small AUV. The SLAM is one of such alternative navigation methods for measuring the environment that the vehicle is passing through and providing relative position of AUV by processing the data from sonar measurements. A technique for SLAM algorithm which uses several ranging sonars is presented. This technique utilizes an unscented Kalman filter to estimate the locations of the AUV and objects. In order for the algorithm to work efficiently, the nearest neighbor standard filter is introduced as the algorithm of data association in the SLAM for associating the stored targets the sonar returns at each time step. The proposed SLAM algorithm is tested by simulations under various conditions. The results of the simulation show that the proposed SLAM algorithm is capable of estimating the position of the AUV and the object and demonstrates that the algorithm will perform well in various environments.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.13-16
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• 2005

It would be desirable to have methods for specific problems, which have low communication costs compared to the computation costs, and in specific applications, algorithms need to be developed and mapped onto parallel computer architectures. Main memory access for shared memory system or global communication in message passing system deteriorate the computation speed. In this paper, it is found that the m-step generalization of the block Lanczos method enhances parallel properties by forming m simultaneous search direction vector blocks. QR factorization, which lowers the speed on parallel computers, is not necessary in the m-step block Lanczos method. The m-step method has the minimized synchronization points, which resulted in the minimized global communications compared to the standard methods.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.513-516
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• 2002

The flow structure and heat transfer characteristics of a turbulent buoyant jet were investigated experimentally. The instantaneous temperature and velocity fields in the near field were measured using a two-frame PIV and PLIF techniques. A thin light sheet illuminated a two-dimensional cross section of the buoyant jet in which Rhodamine B was added as a fluorescent dye. The intensity variations of LIF signal from Rhodamine B molecules scattered by the laser light were captured by a CCD camera after passing an optical filter. By ensemble averaging the instantaneous temperature and velocity fields, the mean temperature and velocity fields as well as the spatial distributions of turbulent statistics were obtained. The results show the flow structure and convective heat transfer of the developing shear layer in the near field.

• Ecology and Resilient Infrastructure
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• v.5 no.1
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• pp.1-10
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• 2018

We examined the effect of simultaneous application of phosphorus (P) and iron (Fe) on the phytotoxicity of lettuce in arsenic (As) contaminated soil using response surface methodology (RSM). To stabilize As and supply nutrient into soil, Fe and P were treated, respectively. Water soluble As and P was decreased by Fe application but increased by P application. Through phytotoxicity test, the result showed that only the addition of P affected lettuce root elongation even though both P and Fe were added. The correlation coefficients between root elongation and other indices indicated that the As content in the roots seemed to be the main reason that root growth was impeded. We could verify that the former result was not a passing phenomenon and Fe was necessarily needed to protect secondary pollution by exclusive usage of P fertilizer.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.5
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• pp.163-169
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• 2006

In order to use parallel computers in specific applications, algorithms need to be developed and mapped onto parallel computer architectures. Main memory access for shared memory system or global communication in message passing system deteriorate the computation speed. In this paper, it is found that the m-step generalization of the block Lanczos method enhances parallel properties by forming in simultaneous search direction vector blocks. QR factorization, which lowers the speed on parallel computers, is not necessary in the m-step block Lanczos method. The m-step method has the minimized synchronization points, which resulted in the minimized global communications and main memory access compared to the standard methods.