• Journal of Korean Society of Steel Construction
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• v.17 no.6 s.79
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• pp.681-688
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• 2005

This study investigates an existing steel plate girder railroad bridge after superstructure rehabilitation to monitor static and dynamic responses using Fiber Bragg Grating (FBG) sensors. This paper also presents an experimental technique to estimate the vertical deflection of the bridge using FBG sensors. Seven FBG sensors are multiplexed in a single optical fiber and installed in parallel pairs along the length of the bridge, with one set at the top flange and the other at the bottom flange. In addition to FBG sensors, a conventional electric strain gauge and anLVDT are installed at the mid-span of the bridge for comparison. A test train consisting of one locomotive is placed at the center of the bridge to produce the maximum static effect. The train is also made to pass over the bridge at different speeds ranging from 10 km/h to 90 km/h to monitor the dynamic response of the bridge. This study demonstrates that the measured strains using the FBG sensor compared well with the readings from the electric strain gauge. The results show that the proposed instrumentation technique is capable of estimating the vertical deflection of the bridge for various loading conditions, which is crucial in structural health monitoring. Several dynamic characteristics of the bridge were also identified.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.181-192
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• 2003

We developed a mathematical simulation model to portray the vertical distribution of soil water from the measured weather data and the known soil hydraulic properties, and then compared simulation results with the periodically measured soil water profiles obtained on Jungdong sandy loam to verify the model, In this model, we solved potential-based Richards' equation by the implicit finite difference method superimposed on the predictor-corrector scheme. We presumed that: soil hydraulic properties are homogeneous; soil water flows isothermally; hysteresis is not considered; no vapor flows; no heat transfers into the soil profiles; and water added to soil surface is distributed along the soil profile following partial displacement principle. The input data were broadly classified into two groups: (1) daily weather data such as rainfall, maximum and minimum air temperatures, relative humidity and solar radiation and (2) soil hydraulic data to approximate unsaturated hydraulic conductivity and water retention. Each hydraulic polynomial function approximated using the Chebyshev polynomial and least square difference technique in tandem showed a fairly good fit of the given set of data. Vertical distribution of soil water as approximations to the Richards' equation subject to changing surface and phreatic boundaries was solved numerically during 53 days with a comparatively large time increment, and this pattern agreed well with field neutron scattering data, except for the surface 0.1 m slab.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.96-106
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• 2017

This study aims to identify the chemical compositions and antioxidant activities of essential oil, extracted from the leaves of Neolitsea aciculata (Blume) Koidz by the hydrodistillation method. To the end, the chemical composition of N. aciculata leaf oil was firstly analyzed through GC/MS. The major constituents of essential oil were found to be: cis-ocimene (11.00%), trans-ocimene (9.65%), elemol (9.15%), ${\beta}$-elemene (8.75%), germacrene-D (7.55%), trans-caryophyllene (5.90%), ${\gamma}$-elemene (5.40%) and ${\tau}$-muurolol (4.95%). Then, the antioxidant potential of the essential oil was evaluated by the methods of total polyphenolic content (TPC) assay, DPPH radical scavenging activity, ABTS radical scavenging activity and ferric reducing antioxidant power (FRAP). It was estimated that the total polyphenolic content of the oil was $136.7{\pm}0.13\;mg\;GAE/g$ and the efficient concentration of the oil required to scavenge 50% DPPH radicals ($EC_{50}$ value) was $639.33\;{\mu}g/m{\ell}$. Also, ABTS radical scavenging activity was identified to be concentration dependent, while the FRAP value was $31.21{\pm}0.12\;{\mu}M$ $FeSO_4{\cdot}7H_2O/g$. Such figures, as a result, suggest that the essential oil extracted from the leaves of N. aciculata has its antioxidant activity, which can serve as significant health functional benefits.

• Journal of Korea Water Resources Association
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• v.43 no.6
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• pp.571-581
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• 2010

This study analyzed rainfall-runoff characteristics by deriving multiple impulse responses. The concept of competing impulse responses was used for deriving multiple impulse responses. Based on this concept, each response function derived competes to be selected for simulating the runoff measured. This concept of competing linear impulse responses was applied to four basins, Jeongseon, Yeongwol, Youngchoon and Chungju Dam. One to three impulse responses have been derived and compared each other considering basin characteristics. First, in case of deriving one linear impulse response, the peak flow of the impulse response was found to be increased according to their study basins area. In case of deriving two linear impulse response, the peak flow of the first impulse response and the duration of the second impulse response were increased according to their basin size. The case of deriving three impulse response showed similar characteristics of deriving two impulse responses. However, the peak flow of third impulse response was very small and lasted quite long time. Summarizing these results considering the basin characteristics, the first impulse response seems to be related with the surface runoff, the second impulse with the surface runoff and interflow, and the third impulse response with the interflow and base flow.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1062-1062
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• 2001

The concept of “precision agriculture” or “site-specific farming” is usually confined to the fields of soil science, crop science and agronomy. However, because plants grow in soil, animals eat plants, and humans eat animal products, it could be argued (perhaps with some poetic licence) that the fields of feed quality, animal nutrition and animal production should also be considered in this context. NIR spectroscopy has proved over the last 20 years that it can provide a firm foundation for quality measurement across all of these fields, and with the continuing developments in instrumentation, computer capacity and software, is now a major cog in the wheel of precision agriculture. There have been a few giant leaps and a lot of small steps in the impact of NIR on the animal world. These have not been confined to the amazing advances in hardware and software, although would not have occurred without them. Rapid testing of forages, grains and mixed feeds by NIR for nutritional value to livestock is now commonplace in commercial laboratories world-wide. This would never have been possible without the pioneering work done by the USDA NIR Forage Research Network in the 1980's, following the landmark paper of Norris et al. in 1976. The advent of calibration transfer between instruments, algorithms which utilize huge databases for calibration and prediction, and the ability to directly scan whole grains and fresh forages can also be considered as major steps, if not leaps. More adventurous NIR applications have emerged in animal nutrition, with emphasis on estimating the functional properties of feeds, such as in vivo digestibility, voluntary intake, protein degradability and in vitro assays to simulate starch digestion. The potential to monitor the diets of grazing animals by using faecal NIR spectra is also now being realized. NIR measurements on animal carcasses and even live animals have also been attempted, with varying degrees of success, The use of discriminant analysis in these fields is proving a useful tool. The latest giant leap is likely to be the advent of relatively low-cost, portable and ultra-fast diode array NIR instruments, which can be used “on-site” and also be fitted to forage or grain harvesters. The fodder and livestock industries are no longer satisfied with what we once thought was revolutionary: a 2-3 day laboratory turnaround for fred quality testing. This means that the instrument needs to be taken to the samples rather than vice versa. Considerable research is underway in this area, but the challenge of calibration transfer and maintenance of instrument networks of this type remains. The animal world is currently facing its biggest challenges ever; animal welfare, alleged effects of animal products on human health, environmental and economic issues are difficult enough, but the current calamities of BSE and foot and mouth disease are “the last straw” NIR will not of course solve all these problems, but is already proving useful in some of these areas and will continue to do so.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1523-1523
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• 2001

The wine industry requires practical methods for objectively measuring the composition of both red wine grapes on the vine to determine optimal harvest time; and of freshly harvested grapes for efficient allocation to vinery process streams for particular red wine products, and to determine payment of contract grapegrowers. To be practical for industry application these methods must be rapid, inexpensive and accurate. In most cases this restricts the analyses available to measurement of TSS (total soluble solids, predominantly sugars) by refractometry and pH by electropotentiometry. These two parameters, however, do not provide a comprehensive compositional characterization for the purpose of winemaking. The concentration of anthocyanin pigment in red wine grapes is an accepted indicator of potential wine quality and price. However, routine analysis for total anthocyanins is not considered as a practical option by the wider wine industry because of the high cost and slow turnaround time of this multi-step wet chemical laboratory analysis. Recent work by this ${group}^{l,2}$ has established the capability of near infrared (NIR) spectroscopy to provide rapid, accurate and simultaneous measurement of total anthocyanins, TSS and pH in red wine grapes. The analyses may be carried out equally well using either research grade scanning spectrometers or much simpler reduced spectral range portable diode-array based instrumentation. We have recently expanded on this work by collecting thousands of red wine grape samples in Australia. The sample set spans two vintages (1999 and 2000), five distinct geographical winegrowing regions and three main red wine grape varieties used in Australia (Cabernet Sauvignon, Shiraz and Merlot). Homogenized grape samples were scanned in diffuse reflectance mode on a FOSE NIR Systems6500 spectrometer and subject to laboratory analysis by the traditional methods for total anthocyanins, TSS and pH. We report here an analysis of the correlations between the NIR spectra and the laboratory data using standard chemometric algorithms within The Unscrambler software package. In particular, various subsets of the total data set are considered in turn to elucidate the effects of vintage, geographical area and grape variety on the measurement of grape composition by NIR spectroscopy. The relative ability of discrete calibrations to predict within and across these differences is considered. The results are then used to propose an optimal calibration strategy for red wine grape analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3885-3892
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• 2010

Safety-Critical systems, such as Plant Protection Systems in nuclear power plant, plays a key role that the facilities can be operated without undue risk to the health and safety of public and environment, and those systems shall be designed, fabricated, installed, and tested to quality standards commensurate with the importance of the functions to be performed. Computer-based Instrumentation and Control Systems to perform the safety-critical function have Real Time Operating Systems to control and monitoring the sub-system and executing the application software. The safety-critical Real Time Operating Systems shall be designed, analyzed, tested and evaluated to have capability to maintain a high integrity and quality. However, local nuclear power plants have applied the real time operating systems on safety critical systems through Commercial Grade Item Dedication method, and this is the reason of lack of detailed methodology on assessing the safety of real time operating systems, expecially to the new developed one. This paper presents the methodology and experiences of safety evaluation on safety-critical Real Time Operating Systems based upon design requirements. This paper may useful to develop and evaluate the safety-critical Real Time Operating Systems in other industry to ensure the safety of public and environment.

• Restorative Dentistry and Endodontics
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• v.36 no.3
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• pp.180-187
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• 2011

Introduction: Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review: The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion: Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

• Journal of Environmental Science International
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• v.14 no.12
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• pp.1119-1127
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• 2005

The management of data on biological diversity is presently complex and confusing. This study was initiated to construct a database so that such data could be stored in a data management, and analysis instrument to correct the problems inherent in the current incoherent storage methods. MySQL was used in DBMS(DataBase Management System), and the program was basically produced using Java technology Also, the program was developed so people could adapt to the requirements that are changing every minute. We hope this was accomplished by modifying easily and quickly the advanced programming technology and patterns. To this end, an effective and flexible database schema was devised to store and analyze diversity databases. Even users with no knowledge of databases should be able to access this management instrument and easily manage the database through the World Wide Web. On a basis of databases stored in this manner, it could become routinely used for various databases using this analysis instrument supplied on the World Wide Web. Supplying the derived results by using a simple table and making results visible using simple charts, researchers could easily adapt these methods to various data analyses. As the diversity data was stored in a database, not in a general file, this study makes the precise, error-free and high -quality storage in a consistent manner. The methods proposed here should also minimize the errors that might appear in each data search, data movement, or data conversion by supplying management instrumentation on the Web. Also, this study was to deduce the various results to the level we required and execute the comparative analysis without the lengthy time necessary to supply the analytical instrument with similar results as provided by various other methods of analysis. The results of this research may be summerized as follows: 1)This study suggests methods of storage by giving consistency to diversity data. 2)This study prepared a suggested foundation for comparative analysis of various data. 3)It may suggest further research, which could lead to more and better standardization of diversity data and to better methods for predicting changes in species diversity.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.253-260
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• 2015

There are many efforts to mechanize the process for underwater port construction due to the severe and adverse working environment. This paper presents an underwater construction robot to level rubbles on the seabed for port construction. The robot is composed of a blade and a multi-functional arm to flatten the rubble mound with respect to the reference level at uneven terrain and to dig and dump the rubbles. This research analyzes the kinematics of the blade and the multi-functional arm including track and swing motions with respect to a world coordinate assigned to a reference depth sensor. This analysis is conducted interfacing with the position and orientation sensors installed at the robot. A hydraulic control system is developed to control a track, a blade and a multi-functional arm for rubble leveling work. The experimental results of rubble leveling work conducted by the robot are presented in land and subsea. The working speed of the robot is eight times faster than that of a human diver, and the working quality is acceptable. The robot is expected to have much higher efficiency in deep water where a human diver is unable to work.