• Structural Engineering and Mechanics
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• v.40 no.4
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• pp.471-488
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• 2011

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast strengthened by transverse cables and struts. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the heavy traffic on the bridge, and threats from typhoons and earthquakes originated in areas nearby, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. Baseline finite element models of various levels of sophistication have been built not only to match the bridge geometry and cable forces specified on the as-constructed drawings but also to be calibrated using the vibration measurement data captured by the Wind and Structural Health Monitoring System. This paper further describes the analysis of axle loading data, as well as the generation of random axle loads and simulation of vibrations of the bridge using the finite element models. Various factors affecting the vehicular loading on the bridge will also be examined.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.10-15
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• 2017

Research interest has strongly focused on developing a method for effectively transmitting bio-signals over a distance using a wireless wearable device. In this paper, we describe a procedure for the design and fabrication of a wearable antenna based on embroidering conductive threads to clothing capable of transmitting electrocardiogram signals. 3D electromagnetic simulation software and embroidery software were used to design and fabricate the conductive thread-based antenna, respectively. The measurement results show that the reflection coefficient of the fabricated antenna prototype exhibits excellent antenna impedance matching characteristics of less than -10dB in the Zigbee 2.4GHz frequency band. We also verified that the electrocardiogram data could be effectively received and monitored in real-time by a receiver 220m away from the transmitter.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.1-9
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• 2015

PURPOSES : The objective of this study is to propose a quality control and quality assurance method for use during asphalt pavement construction using non-destructive methods, such as ground penetrating radar (GPR) and an infrared (IR) camera. METHODS : A 1.0 GHz air-coupled GPR system was used to measure the thickness and in situ density of asphalt concrete overlay during the placement and compaction of the asphalt layer in two test construction sections. The in situ density of the asphalt layer was estimated based on the dielectric constant of the asphalt concrete, which was measured as the ratio of the amplitude of the surface reflection of the asphalt mat to that of a metal plate. In addition, an IR camera was used to monitor the surface temperature of the asphalt mat to ensure its uniformity, for both conventional asphalt concrete and fiber-reinforced asphalt (FRA) concrete. RESULTS : From the GPR test, the measured in situ air void of the asphalt concrete overlay gradually decreased from 12.6% at placement to 8.1% after five roller passes for conventional asphalt concrete, and from 10.7% to 5.9% for the FRA concrete. The thickness of the asphalt concrete overlay was reduced from 7.0 cm to 6.0 cm for the conventional material, and from 9.2 cm to 6.4 cm for the FRA concrete. From the IR camera measurements, the temperature differences in the asphalt mat ranged from $10^{\circ}C$ to $30^{\circ}C$ in the two test sections. CONCLUSIONS : During asphalt concrete construction, GPR and IR tests can be applicable for monitoring the changes in in situ density, thickness, and temperature differences of the overlay, which are the most important factors for quality control. For easier and more reliable quality control of asphalt overlay construction, it is better to use the thickness measurement from the GPR.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.1
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• pp.6-9
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• 1994

Previously reported Ar/N$_2$ratios in groundwater have been measured by single ion monitoring (Barnes et al., 1975; Vogel et al., 1981; Mariotti et al., 1988). The detector geometry and flared flight tube in VG Optima isotopic ratio mass spectrometer appeared to be fortuitously aligned for the simultaneous measurement of Ar/N$_2$ratios. Method development included mechanical adjustments to optimize the mass spectrometer for Ar/N$_2$ratio measurements followed by development of a preparation system for the extraction of air-saturated water samples. Samples containing known Ar/N$_2$ratios were used to assess accuracy and precision, and to test the applicability of methods for measurements of aqueous Ar/N$_2$ratios. The results indicated that the prepared air-saturated water samples were almost identical to the predicted Ar/N$_2$ratios (p ＜0.001). Groundwater samples were collected from on-going research sites, Shelton and Grand Island, Nebraska. Samples from the Grand Island sludge injection site form a lower boundary for worldwide reported Ar/N$_2$ratios. These lower Ar/N$_2$ratios can be explained by the production of nitrogen gas from this site, where denitrification was reported previously.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.705-711
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• 2007

Green quantum-dot nanocrystal (QD525) with anti-microcystin monoclonal antibody was applied for detection of microcystin, a monocyclic peptide hepatotoxin, extracted from the culture of Microcystis aeruginosa. The presence of microcystin in the cell lysate was verified by HPLC analysis with UV absorbance at 238 nm. Microcystis cell extract exhibited fluorescence emission spectra, which peak was around 460 nm because of their complex organic substances. When a spherical QD525 antibody conjugates (10~20 nm in diameter) were bound to the microcystins in the Microcystis cell lysate, the fluorescence intensity of the primary peak at 525 nm diminished while the secondary emission peak at 460 nm slightly increased intensities. It is due to energy transfer from the primary (major) to the secondary (minor) peak, resulting from physical deformation of QD525 and different environmental factors. On the other hand, other cell extracts did not show any fluorescence emission change. This study is very available for detecting and monitoring the microcystin because it is one step assay without washing step and portable spectrophotometer makes on-site measurement possible. For health risk assessment of the microcystin, the reliable and rapid system to detect and quantify microcystin is seriously required.

• Wind and Structures
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• v.23 no.4
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• pp.313-350
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• 2016

Taipei 101 Tower, which has 101 stories with height of 508 m, is located in Taipei where typhoons and earthquakes commonly occur. It is currently the second tallest building in the world. Therefore, the dynamic performance of the super-tall building under strong wind actions requires particular attentions. In this study, Large Eddy Simulation (LES) integrated with a new inflow turbulence generator and a new sub-grid scale (SGS) model was conducted to simulate the wind loads on the super-tall building. Three-dimensional finite element model of Taipei 101 Tower was established and used to evaluate the wind-induced responses of the high-rise structure based on the simulated wind forces. The numerical results were found to be consistent with those measured from a vibration monitoring system installed in the building. Furthermore, the equivalent static wind loads on the building, which were computed by the time-domain and frequency-domain analysis, respectively, were in satisfactory agreement with available wind tunnel testing results. It has been demonstrated through the validation studies that the numerical framework presented in this paper, including the recommended SGS model, the inflow turbulence generation technique and associated numerical treatments, is a useful tool for evaluation of the wind loads and wind-induced responses of tall buildings.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.407-422
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• 2014

Objective: The purpose of the study is to develop quantitative usability evaluation criteria for senior-friendly autonomous transportation robot. Background: The Republic of Korea has become the most rapidly aging society, and is anticipated to enter the post-aged society in 2026. To raise the quality of life of a senior with limited mobility and to reduce the burden of caregivers, many high-tech assistive products with information technologies are developed nowadays. The senior-friendly autonomous transportation robot is one person robot vehicle to move a senior to the destination for hospitals, nursing homes or silver town complex. With built-in navigation system and environmental monitoring censors, it automatically seeks the path to the destination and avoids collision to obstacles and pedestrians on the way. Due to the early stage of the product, few usability studies in this field have been done, mostly on general service robots to assist seniors, power wheelchairs and delivery robots. ISO and KS standards for the service robots are focused on safety. Method: Based on the reference usability index, the early draft of the usability evaluation questionnaires was developed. After small group tests and interviews, the experts modified the initial draft to the Usability Evaluation Criteria for Senior-Friendly Autonomous Transportation Robot (UEC-SFATR). Result: UEC-SFATR consisted of 4 subscales - Safety, Controllability, Efficiency and Satisfaction. All of the 4 subscales of UEC-SFATR were passed the reliability criteria by 4 groups of seniors, divided by gender and familiarity of smart-devices. Conclusion: UEC-SFATR covers wider area of user experiences of the SFATR and is a good measurement tool to help both the users and developers of the robot. Application: This study provides guide to the future product development and product competitiveness evaluation by quantifying user experiences for the SFATR.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.9
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• pp.1035-1042
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• 2014

Object recognition is one of the key technologies of the monitoring system for the prevention of various intelligent crimes. The height is one of the physical information of a person, and it may be important information for identification of the person. In this paper, a method which can detect pedestrians from CCTV images and estimate the height of the detected objects, is proposed. In this method, GMM (Gaussian Mixture Model) method was used to separate the moving object from the background and the pedestrian was detected using the conditions such as the width-height ratio and the size of the candidate objects. The proposed method was applied to the CCTV video, and the height of the pedestrian at far-distance, middle- distance, near-distance was estimated for the same person, and the accuracy was evaluated. Experimental results showed that the proposed method can estimate the height of the pedestrian as the accuracy of 97% for the short-range, 98% for the medium-range, and more than 97% for the far-range. The image sizes for the same pedestrian are different as the position of him in the image, it is shown that the proposed algorithm can estimate the height of pedestrian for various position effectively.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.4
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• pp.93-100
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• 2002

The current from the feed motor of a machine tool contains substantial information about the machining state. There have been many researches that investigated the current as a measure for the cutting farces. However it has been reported that this indirect measurement of the cutting farces from the feed motor current is only feasible in low frequency. In this research, it was presented that the bandwidth of the current monitoring can be expanded to 130 Hz. And the unusual behavior of the current was examined in this bandwidth. The cross-feed directional cutting force influences the machined surface of the workpiece, which makes it necessary to estimate this force to control the roughness of the machined sulfate. The current exists in the stationary feed motor, and it can give the useful information on the quality of the machined surface. But the unpredictable behavior of the current prevents applying the current to prediction of the cutting state. Empirical approach was conducted to resolve the problem. As a result, the current was shown to be related to the accumulation of the accumulation of the infinitesimal rotation of the motor. rotation of the motor. Subsequently the relationship between the current and the cutting force was identified.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.101-105
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• 2016

The number of deaths is often measured to monitor the population health status and priority of health problems. However, number of years of life lost (YLL) is a more appropriate indicator in some cases. We have calculated the YLL of adult cancers and its trend over the past few years in Yazd to provide planners with baseline data. Data obtained from death registration system were used to calculate the YLL, based on each individual's age at death, and the standardized expected YLL method was applied with a discount rate of 0.03, an age weight of 0.04, and a correction factor of 0.165. All data were analyzed and prepared in Epi6 and Excel 2007. A total of 3,850 death records were analyzed. Some 550 patients in Yazd province aged ${\geq}20$ die annually due to cancer (male: female ratio 1.3). The average ages at death in lung, CNS, breast cancer and leukemia cases were 68.5, 59, 58.7 and 61, respectively. The age group of 40-59 with 21 % had the highest cancer mortality percentage. Premature cancer deaths have caused 40,753 YLL (5,823 YLL annually). Females lose on average more life years to cancer than do men (11.6 vs 9.8 years). Lung cancer (12.1%), CNS tumors (11.7%) and leukemia (11.4 %) were the leading causes terms of YLL due to all cancers in both sexes. From 2004 to 2010, cancer-caused YLL as a fraction of all YLL increased from 12.8 to 15.2 %. This study can help in the assessment of health care needs and prioritization. Cancer is the major cause of deaths and the trend is increasing. The use of YLLs is a better index for measurement of premature mortality for ranking of diseases than is death counts. Longer periods of observation will make these trends more robust and will help to evaluate and develop, better public health interventions.