• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.17-27
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• 2014

Numerical model became one of most important tools for identifying the state of an existing structure in accordance with development of numerical analysis techniques. A numerical model should be updated based on the measured responses from the existing structure to accurately use the model for identifying the state of the bridge and executing numerical experiments. In this study, a new model updating method based on repetition method without a differential function is introduced and applicability for high speed railway bridge is verified with dynamic stability analysis. A fine measurement based on measurement points roaming method was executed with an wireless measurement system for precise dynamic characteristic analysis. The natural frequencies and mode shapes were estimated by correlation analysis and a mode decomposition technique. An initial numerical model was constructed based on design drawings and the model have been updated in accordance with the introduced model updating method. The results from numerical experiment and field test have been compared for verifying the applicability of the model updating method. And the dynamic stability analysis has been executed to verify the usability of the updated numerical model and the model updating method. It seems that the model updating method can be used for various bridges after evaluation of applicability for other type bridges in further studies.

• Journal of Biosystems Engineering
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• v.24 no.6
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• pp.539-546
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• 1999

Some stress for a plant could be detected to a certain degree by plant physiological measuring technique of the state of the art. The capability of early detection of my measuring system depends on kind of plant and kind and level of stress. The objectives of this study were to evaluate the capability of several fast and intact type plant stress detection systems to detect nitrogen deficiency of cucumber in the field. A series of experiment was carried out with four kinds of intact type measuring devices - a chlorophyll content meter, a chlorophyll fluorescence measurement system, an infrared thermometer and an optical spectrometer. The experiments resulted that the chlorophyll content meter could detect the stress of N deficiency at a confidence level higher than 95% on 3rd day for the earliest case and the detection of high precision was possible from 7th day after the stress was applied. The chlorophyll fluorescence measurement system detected the stress at a confidence level higher than 95% on 3rd day for the earliest case but the detection was not as much precise as the chlorophyll content meter. Leaf temperature measurement noted very poor results to detect the stress. Using the spectrometer, sensitive wavelength regions to detect the stress were searched and found out as 562∼564 nm, 700∼724 nm and 1,886∼1,894 nm. With the spectrometer using any of wavelength within the sensitive wavelength region, detection of the stress at a confidence level higher than 95% was possible from 3rd or 4th day after the stress was applied.

• Journal of Conservation Science
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• v.22
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• pp.31-42
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• 2008

A stone cultural heritage often lacks design drawing and detailed geometric informations, thus it becomes more difficult to conservation and restoration. Even though there is active database of detail shape information and numerical measurement for stone monuments, most of the data is in hard-to-utilize two-dimensional images. The new technology developed to overcome this problem is three-dimensional image scanning system. The multi-storied stone pagoda of the Daewonsa temple was analysed with 3D scanning image data then survey map with orientation displacement was evaluated. The difference of each side became apparent with the members of the stone properties was measured, also horizontal and vertical displacement occurred. Horizontal displacement occurred in increasing severity from left to right and from body section to upper part. The 8th roof stones are leaning toward northwest direction due to lateral displacement. The evaluation and measurement of displacement could cause a little errors due to the characteristics uneven surface of stone monuments, computer program and mistakes from the researcher. In future, more precise measurement and stability studies should be done to suggest that accurate data for conservation and understanding of damage condition can be provided.

• Journal of Conservation Science
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• v.27 no.2
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• pp.181-190
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• 2011

A precision measurement and digital image restoration of the 5th century's gilt bronze cap of Baekje dynasty, excavated from the ancient tomb of Andong, Goheung in 2006, was undertaken. The objective of the scanning is to preserve precise feature of the artefact in the form of digital data by embodying it in 3 dimensional space. Acquirement of the data has been undertaken in the following process : 3D scanning to obtain 3D shape and color information(original data photographing)-3D modelling(joining original data and restoring non-photographed or damaged area)-CG image production. Production of restoration CG image was based on joined shape of original data and each part's measurement on CAD. Non-photographed part and area of loss was restored referring actual measurement and research result of excavated cap from the 5th to 8th century. 3D image restoration is one of artefact restoration methods which restores artefact without risk. It is also undertaken with historical research. As result, this method can enhance aesthetic and academic value of the artefact by successful restoration.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.475-480
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• 2012

In order to establish eLoran (enhanced Long Range Navigation) system, it needs the advancement of receiver, transmitter, data channel addition for Loran information, differential Loran sites for compensating Loran-c signal and ASFs (Additional Secondary Factors) database, etc. In addition, the precise synchronization of transmitting station to the UTC (Coordinated Universal Time) is essential if Loran delivers the high absolute accuracy of navigation demanded for maritime harbor entrance. For better timing synchronization to the UTC among transmitting stations, it is necessary to measure and monitor the transmission delay of the station, and the correction information of the transmitting station should be provided to the user's receivers. In this paper we presented the measurement method of absolute delay of Pohang Loran transmitting station and developed a time delay measurement system and a phase monitoring system for Loran station. We achieved -2.23 us as a result of the absolute phase delay of Pohang station and the drift of Loran pulse of the station was measured about 0.3 us for a month period. Therefore it is necessary to measure the delay offset of transmitting station and to compensate the drift of the Loran signal for the high accuracy application of PNT (Positioning, Navigation and Timing).

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.193-199
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• 1999

Background: Measurement of body temperature is an important parameter in patient management in many clinical conditions. Failure to reach minimal acceptable body temperature standards has been associated with physiological derangements and has necessitated the application of additional therapy. The authors developed a new, simple, accurate thermometry system, which could be used to undertake precise temperature measurement for various clinical conditions. Materials and Methods: A new thermometry system using a specially designed temperature detecting and display system was developed. This system contains a temperature detecting sensor(LM 35CZ), which enables multiple serial checking of heat, data collection and processing computer, and 3-dimensional display system. It provides real time volumetric visualization of temperature distribution of a defined volume and stores and prints the data. Results: With this system, temperature can be measured at multiple interesting sites simultaneously, demonstrated as a 3-dimensional temperature distribution and stored. In well-controlled, systematic experiments a significant correlation has been observed between standard temperature and temperature using this system at various measuring points. Conclusion: This thermometry system is a real-time measurement system, which can demonstrate 3-dimensional heat distribution in experimental phantom and human body and can be used for diagnosing abnormal clinical conditions. In addition, this system reduces the nursing staff work load, providing them more time for long term care to patients.

• Archives of Plastic Surgery
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• v.39 no.5
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• pp.477-482
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• 2012

Background The bone graft for the alveolar cleft has been accepted as one of the essential treatments for cleft lip patients. Precise preoperative measurement of the architecture and size of the bone defect in alveolar cleft has been considered helpful for increasing the success rate of bone grafting because those features may vary with the cleft type. Recently, some studies have reported on the usefulness of three-dimensional (3D) computed tomography (CT) assessment of alveolar bone defect; however, no study on the possible implication of the cleft type on the difference between the presumed and actual value has been conducted yet. We aimed to evaluate the clinical predictability of such measurement using 3D CT assessment according to the cleft type. Methods The study consisted of 47 pediatric patients. The subjects were divided according to the cleft type. CT was performed before the graft operation and assessed using image analysis software. The statistical significance of the difference between the preoperative estimation and intraoperative measurement was analyzed. Results The difference between the preoperative and intraoperative values were $-0.1{\pm}0.3cm^3$ (P=0.084). There was no significant intergroup difference, but the groups with a cleft palate showed a significant difference of $-0.2{\pm}0.3cm^3$ (P<0.05). Conclusions Assessment of the alveolar cleft volume using 3D CT scan data and image analysis software can help in selecting the optimal graft procedure and extracting the correct volume of cancellous bone for grafting. Considering the cleft type, it would be helpful to extract an additional volume of $0.2cm^3$ in the presence of a cleft palate.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.3
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• pp.244-250
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• 2018

Multilateration acquires the transponder signal of target from receivers installed on the ground and calculates the position of the target using the difference of the signal acquisition time of each receiver. One of the factors that influence the positioning accuracy of Multilateration using the TDOA calculation method is the error due to the precision measurement of signal input time. When measuring the signal input time at the receiver, the input signal is sampled using the reference clock of the receiver and a reference sample having the same sampling rate is applied to the cross correlation technique. Therefore, the accuracy of the signal input time is proportional to the reference clock. In this paper, the algorithm for precisely measuring the signal input time by performing cross correlation between the input signal of the receiver and DRS(Delayed Reference Sample) is proposed. In order to verify this, we implemented the pulse signal of the transponder that is transmitted from the target using Matlab. Through the simulation, cross correlation between the proposed DRS and the input signal was performed. From this result, the performance of the precise measurement of signal input time was analyzed.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.3 s.26
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• pp.23-34
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• 2003

Currently, the efficiency of GPS has been increased in the various precise survey like as the control survey and the navigation etc. Also, it is widely used in the deformation analysis of the structure, the measurement of the marine tides, the measurement of the river level and the topographic monitoring of seabed or riverbed by combined the measurement equipment for depth. In this study, we intend to increase in efficiency of the topographic monitoring of seabed or riverbed by combined with DGPS, RTK GPS and echo sounder. For this study, we defined the error correction of the echo sounder with the experiment of water tank which is considered the characteristic of estuary riverbed and then we developed the s/w for 3-dimensional monitoring of estuary riverbed and applied the s/w to field test and improved the various problems. On analyzing topography of estuary riverbed by combined GPS with echo sounder, the draught error which is yielded to change of length from the water surface by the movement of survey vessel to the end of the transducer was eliminated by geometrical rearrangement and we defined the correction formula $z=BM+SAH-DBR_{(i)}-DRT-ED$. The sounding error about the echo sounder and characteristic of estuary riverbed was found by understanding the relation of average diameter ind residual error and we defined correction formula, $Y=0.00474{\ast}ln(X)-0.0045$ by the regression analysis. and then we verified applicability of correction formula.

• Korean Journal of Ecology and Environment
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• v.51 no.3
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• pp.205-211
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• 2018

In this study, we estimated the applicability of length-weight relationship-based biomass calculations by comparison of body length of genus Polyarthra collected from different habitats. Through the comparison, we also tested availability of representative species-specific biomass value of Polyarthra which is often used without length measurement. Polyarthra samples were collected from rivers (Han River and Nakdong River) and reservoir (Paldang Reservoir), and the body length was measured for statistical comparison among habitats and biomass calculations using different equations suggested previously. According to the results, the body length of Polyarthra spp. was significantly different among sampling sites, and the necessity of body length measurement for rotifer species in each situation has been suggested rather than using the representative biomass values which is fixed without considering time and space. Comparison of suggested biomass calculations based on our measured Polyarthra body length, the equation suggested by McCauley showed more reasonable range of biomass values than that suggested by EPA. In addition, in order to calculate more accurate biomass, it is necessary to measure the body length of rotifers, at least more than 44 individuals to reduce error probability to less than 5% with 99% probability. However, since direct measurement of rotifers biomass is limited, it is considered that further analyses are required for more precise application of rotifer biomass of which has high variability due to complex morphologies and species-specific cyclomorphosis often induced by biotic and abiotic factors in the habitats.