• Proceedings of the KIEE Conference
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• summer
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• pp.584-586
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• 2004

This paper deals with the development of on-line fault and lightning stroke section locating system for branched overhead transmission line. The section locating algorithm of this system i3 by analyzing the distribution pattern of current flowing through the overhead ground wire. It composes of three parts; current sensors, local remote terminal unit(RTU) and analysis program at surveillance tenter. Double Rogowski coil sensor having integrating amplifier was designed as current sensor. In order for current pattern analysis, the transmitted waves from each sensor wert synchronized by GPS tim c clock in RTU. While, lightning stroke location are judged only by polarity information of lightning currents. This design has a benefit in simplicity of signal processing unit of RTU.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.422-425
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• 2008

TerraSAR-X is new radar satellite operated at X-band, multi polarization, and multi beam mode. Compared with C-band or L-band SAR, the X-band system inherently suffers from more temporal decorrelation, but is more sensitive to surface deformation monitoring due to short wavelength (3.1 cm) and high spatial resolution (1m-3m). It is generally expected that sensitivity to estimate surface movement using TerraSAR-X will be increased by the factor of 10, compared to current C-band system with low spatial resolution such as ERS-2, Envisat. Many urban areas are experiencing land subsidence due to water, oil and natural gas withdrawal, underground excavation, sediment compaction, and so on. Monitoring of surface deformation is valuable for effectively limiting damage areas. In addition high accuracy and spatially dense subsidence map can be achieved by X-band InSAR observation, promoting identification and separation of various subsidence processes and leading to enhanced understanding via mechanical modeling. In this study we will introduce some initial InSAR results using new TerraSAR-X SAR data for surface deformation monitoring.

• Journal of Ocean Engineering and Technology
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• v.22 no.6
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• pp.52-57
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• 2008

The short-term high temperature creep rupture behavior of Ni-based Alloy718 steel was investigated at the elevated temperatures range of 550 to $700^{\circ}C$ under constant stress conditions. The creep rupture characteristics such as creep stress, rupture time, steady state creep rate, and initial strain were evaluated. Creep stress has a quantitative correlation between creep rupture tim and steady state creep rate. The stress exponents (n, m) of the experimental data at 550, 600, 650 and $700^{\circ}C$ were derived as 33.5, -24.9, 26.1, -21.2, 16.8, -12.8 and 10, -8.2, respectively. The stress exponent decreased with increasing creep temperature. The creep lift prediction was derived by the Larson-Miller parameter (LMP) method and the resultant equation was obtained as follows: T($logt_r$+20)=-0.00252 ${\sigma}^2$-1.377${\sigma}$+-22718.

• Journal of the Korean housing association
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• v.26 no.5
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• pp.89-96
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• 2015

This project was conducted as part of the Building America program that proposed the overall mission to achieve 30-50% reduction in existing building energy use. The purposes of this project were to analyze architectural styles and features named as archetypes of existing homes within the Great Lakes regions that include Michigan and identify the dominant type that would offer significant potential for energy-efficient retrofit. Housing archetypes were analyzed according to vintage, style, and construction characteristics in two target cities within the region. The findings from an intensive case study targeting the City of Ann Arbor established a fundamental framework for characterizing local housing archetypes and determined the dominant housing archetype that needed energy-efficient retrofit. An extended case study then conducted in Grand Rapids additionally refined this framework for the future application. This paper explained the process and data collection method to develop the framework that can be utilized by other researchers to determine the target housing types for energy-retrofit research.

• Journal of Families and Better Life
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• v.7 no.1
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• pp.15-25
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• 1989

The purpose of this study is to examine the factors affecting the consumer's search for information and the relationship between the amount of search and the final price paid. The model indicates the demand for search is affected by the market price of each durable good purchased, the tim available for search, family income, direct cost of search, the initial stock of information, effectiveness of search, and shopping attitudes. The final price savings are a function of search, price of dispersion in the market, the initial stock of information, and effectiveness of search. Data from the Pane Study on Consumer Decisions and Asset Management were used for the empirical testing of the theoretical model. The amount of information search as dependent variable is represented by two different measures, the level of discussion with others and the number of stores visited. The amount of discussion with others depends mainly on the respondent's shopping attitude. The higher the wife's desire to search, the higher the degree of husband's comparison shopping, the less the husband's perception of price-quality relationship, the higher the level of discussions with others. The number of stores visited depends on the average market price of product purchased and the level of family income. The higher the average market price and he higher the level of family income, the greater the number of stores visited. The final savings depend upon the level of information search. The greater the number of store visited, but the less the purchase is discussed with stores, the higher the final savings are.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.268-273
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• 2000

Velocity-dependent increase in tonic stretch reflexes is one of the prominent characteristics of spasticity. It is very important to evaluate spasticity objectively and quantitatively before and after treatment for physicians. An accurate quantitative biomechanical evaluation for the spasticity which is caused by the disorder of central nervous system is made in this study. A sudden leg dropper which is designed to generate objective testing environment at every trial gives very effective environment for the test. Kinematic data are archived by the 3-dimensional motion analysis system($Elite^{(R)}$, B.T.S., Italy). Kinematic data are angle and angular velocity of lower limb joints, and length and lengthening velocity of lower limb muscle. A program is also developed to analyze the kinematic data of lower limb, contraction and relaxation length of muscles, and dynamic EMG data at the same tim. To evaluate spasticity quantitatively, total 31 parameters extracted from goniogram, EMG and muscle model are analyzed. Statistical analysis are made for bilateral correlations for all parameters. The described instrumentation and parameters to make quantitative and objective evaluation of spasticity shows good results.

• Steel and Composite Structures
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• v.23 no.2
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• pp.205-215
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• 2017

The use of advanced fibre composite materials in bridge engineering offers alternative solutions to structural problems compared to traditional construction materials. Advanced composite or fibre reinforced polymer (FRP) materials have high strength to weight ratios, which can be especially beneficial where dead load or material handling considerations govern a design. However, the reduced weight and stiffness of FRP footbridges results in generally poorer dynamic performance, and vibration serviceability is likely to govern their design to avoid the footbridge being "too lively". This study investigates the dynamic behaviour of the 51.3 m span Wilcott FRP suspension footbridge. The assessment is performed through a combination of field testing and finite element analysis, and the measured performance of the bridge is being used to calibrate the model through an updating procedure. The resulting updated model allowed detailed interpretation of the results. It showed that non-structural members such as the parapets can influence the dynamic behaviour of slender, lightweight footbridges, and consequently their contribution must be included during the dynamic assessment of a structure. The test data showed that the FRP footbridge is prone to pedestrian induced vibrations, although the measured response levels were lower than limits specified in relevant standards.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.871-876
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• 2006

In this thesis, to accurately measure 3D face information using the spatial encoding patterns, the new algorithm to segment the pattern images from initial face pattern image is proposed. If the obtained images is non-homogeneous texture and ambiguous boundary pattern, the pattern segmentation is very difficult. Furthermore. the non-encoded areas by accumulated error are occurred. In this thesis, the FCM(fuzzy c-means) clustering method is proposed to enhance the robust encoding and segmentation rate under non-homogeneous texture and ambiguous boundary pattern. The initial parameters for experiment such as clustering class number, maximum repetition number, and error tolerance are set with 2, 100, 0.0001 respectively. The proposed pattern segmentation method increased 8-20% segmentation rate with conventional binary segmentation methods.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.287-291
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• 2009

The heterogeneous decomposition of ammonia on a quartz surface in an inverted, stagnation-point flow reactor was investigated using a measurement reactor and a numerical model of the reactor. In the experiments, 8 mole% of ammonia in nitrogen was used and the temperature of an electric heater was set in the range $300{\sim}900^{\circ}C$ to heat the quartz surface where the decomposition took place. Gas temperatures and ammonia concentrations in the reactor obtained using in situ Raman spectroscopy were analyzed with the numerical model and it was revealed that, depending on the heater temperature, the temperature of the quartz surface was estimated to be in the range $235{\sim}619^{\circ}C$ and the activation energy of the decomposition on the surface was in the range 10.9~15.8 kcal/mol.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1290-1298
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• 2000

Multimedia Systems such as VOD(Video On Demand) and MOD (Multimedia On Demand) need to support continuous media operations which are randomly called by concurrent users and require that stored media be accessed in real-tim. To satisfy such a requirements, disk arrays consisting of multiple disks are generally used as storage systems. Under the real-time environments to provide users with accessing continuous media in the parallel and concurrent manner, storage systems should be able to deal with user requests independently. In this paper, we present a new fault-tolerant continuous media storage system called PADA(PRR\ulcorner bAsed Disk Array), which is based on a PRR\ulcorner (Prime Round Robin with Grouped Parties) disk placement scheme with enhanced reliability nd load-balancing. We have compared and evaluated the storage space overhead for fault-tolerance, the reliability of diks array systems, the degree of disk load0-balancing, the demanded buffer space, the maximum number of users being capable of supporting and the fault recovery overhead for PADA, RAID 5 and Declustered storage systems. According to the results, PADA is the best among them in that PADA satisfies load-balancing more effectively and servces more user in case of arbitrary-rate retrievals.