• Journal of Korea Technology Innovation Society
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• v.20 no.4
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• pp.1262-1287
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• 2017

Recently, forecasting for next-generation technologies have influenced the competitiveness of companies. However, in previous studies, only extract factors influencing the adoption of technology have been investigated. Also, there are few researches on the importance of each decision factors or the competition between technologies. In this research, Lotka-Volterra model is used to confirm the technological competition in the new technology choice timing when the competition is intensified due to the emergence of new technologies. For purpose of this study, estimate the LVC model based on the data of the past competition and then derived the factors affecting the technology of competition and substitution from the literature survey. After that, we confirmed the factor value between the past and the present technology competition. The difference between the factor values derived from the previous step is used to revise the model estimated from the past data base. At this stage, regression analysis is used to derive the importance of each factor and use it as the weight. Through the correction model, the competitiveness is identified through 1:1 comparison with competition candidate technology and existing dominant design technology. In this research, we quantitatively propose the possibility that a specific technology can become a dominant design in the next generation, based on the difference in factor values and importance. This results will help the company's R&D strategy and decision making.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.2
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• pp.119-128
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• 2008

Thermal assessment of a new CANDU spent fuel disposal system, which improves the retrievability of the spent fuel and enhances the densification factor compared with the Korean Reference disposal System, is carried out in this study. The canisters for CANDU spent fuels are stored for long term and cooled by natural convection in the proposed disposal system for the retrievability. The steady state thermal analyses for proposed CANDU disposal system are carried out with the ANSYS 10.0 CFX code. The thermal analyses are performed through two steps. At the first step, the sensitivity of the disposal tunnel spacing is analysed. The differences of maximum temperatures by several tunnel spacings are calculated at three points in the disposal tunnel. The result shows that the differences of the temperature at the three points are almost negligible because 99% of the decay heat is removed by natural convection. At the second procedure, 60m tunnel spacing with a ventilation system instead of natural convection is considered. The result is applied to the calculation of the canister surface temperature in disposal tunnel as boundary conditions. Consequently, the average and the maximum surface temperature of disposal canisters are $79.9^{\circ}C$ and $119^{\circ}C$, respectively. The inner maximum temperature of a basket in the disposal canister is calculated as $140.9^{\circ}C$. The maximum temperature of the basket meets the thermal requirement for the CANDU spent fuel cladding.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.175-182
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• 2000

Spatial interpolation of daily temperature forecasts and observations issued by public weather services is frequently required to make them applicable to agricultural activities and modeling tasks. In contrast to the long term averages like monthly normals, terrain effects are not considered in most spatial interpolations for short term temperatures. This may cause erroneous results in mountainous regions where the observation network hardly covers full features of the complicated terrain. We developed a spatial interpolation model for daily minimum temperature which combines inverse distance squared weighting and elevation difference correction. This model uses a time dependent function for 'mountain slope lapse rate', which can be derived from regression analyses of the station observations with respect to the geographical and topographical features of the surroundings including the station elevation. We applied this model to interpolation of daily minimum temperature over the mountainous Korean Peninsula using 63 standard weather station data. For the first step, a primitive temperature surface was interpolated by inverse distance squared weighting of the 63 point data. Next, a virtual elevation surface was reconstructed by spatially interpolating the 63 station elevation data and subtracted from the elevation surface of a digital elevation model with 1 km grid spacing to obtain the elevation difference at each grid cell. Final estimates of daily minimum temperature at all the grid cells were obtained by applying the calculated daily lapse rate to the elevation difference and adjusting the inverse distance weighted estimates. Independent, measured data sets from 267 automated weather station locations were used to calculate the estimation errors on 12 dates, randomly selected one for each month in 1999. Analysis of 3 terms of estimation errors (mean error, mean absolute error, and root mean squared error) indicates a substantial improvement over the inverse distance squared weighting.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.204-208
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• 2000

Little information is available for the temporal variation in air temperature profile within rice canopies under development, while much works have been done for a fully developed canopy. Fine wire thermocouples of 0.003 mm diameter (chromel-constantan) were installed at 10 vertical heights by a 10 cm step in a paddy rice field to monitor the air temperatures over and within the developing rice canopy from one month after transplanting (June 29) to just before heading (August 24). According to a preliminary analysis of the data, we found neither the daytime temperature maximum nor the night time minimum at the active radiation surface (the canopy height with maximum leafages) during this period, which is a typical profile of a fully developed canopy. Air temperature within the canopy never exceeded that above the canopy at 1.5 m height during the daytime. Temporal march of the within-canopy profile seemed to be controlled mainly by the ambient temperature above the canopy and the water temperature beneath the canopy, and to some extent by the solar altitude, resulting in alternating isothermal and inversion structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5955-5967
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• 2015

This study targets to recognize needs of adopting public management system in Urban Renewal Project. and to establish evaluation level of public management system using policy evaluation framework for establishing perspective and systemic level. Also, this study constructed basic principles as expanded concept like Public, expertise, participation, rationality, and sustainability based on previous studies and expert opinion. AHP analysis results are following. In case of upper level, post management and continuity are important factors. Also in case of under level, making stable economic system, honest operating system, reducing development costs, local development with self-sufficiency were important factors. through empirical results, the implications are following. First, public management system needs to develop a consistent principle from planning step to post management. Second, it is essential point that continuous retraining between involved people and drawing residents participate in progress activity. Third, when evaluating public management system, it is need that emphasize non-physical factor like conflict issue between stakeholder.

• Journal of the Korean Society of Safety
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• v.11 no.4
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• pp.143-150
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• 1996

This is an explicit-Implicit, finite element analysis for linear as well as nonlinear hygrothermal stress problems. Additional features, such as moisture diffusion equation, crack element and virtual crack extension(VCE ) method for evaluating J-integral are implemented in this program. The Linear Elastic Fracture Mechanics(LEFM) Theory is employed to estimate the crack driving force under the transient condition for and existing crack. Pores in materials are assumed to be saturated with moisture in the liquid form at the room temperature, which may vaporize as the temperature increases. The vaporization effects on the crack driving force are also studied. The Ideal gas equation is employed to estimate the thermodynamic pressure due to vaporization at each time step after solving basic nodal values. A set of field equations governing the time dependent response of porous media are derived from balance laws based on the mixture theory Darcy's law Is assumed for the fluid flow through the porous media. Perzyna's viscoplastic model incorporating the Von-Mises yield criterion are implemented. The Green-Naghdi stress rate is used for the invariant of stress tensor under superposed rigid body motion. Isotropic elements are used for the spatial discretization and an iterative scheme based on the full newton-Raphson method is used for solving the nonlinear governing equations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1090-1099
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• 2013

The purpose of this study was to examine difference in life satisfaction by social activity type in baby boomers. Sampling 1,115 baby boomers, gender and region were assigned. A questionnaire survey was carried out from August to October in 2011. As a result of research, first, the typology of social activity in baby boomers includes 3 groups. The passive social-participation type is the cluster to which 36.8% of the baby boomers belong. They do not join income activity or civic-group activity at all. A case of doing religious activity or family activity includes a minority. There are primarily lots of women and posteriori baby boomers. Academic background level or household income is lower compared to other clusters. The life satisfaction level is moderate. Second, the active social-participation type is the cluster to which 33.8% of the baby boomers belong. They are positive in all the social activities including income activity. What there are lots of women and posteriori baby boomers is similar to the passive social-participation type. However, the academic background or the averagely monthly household income is the highest compared to other clusters. Even the life satisfaction level is the highest. Third, the economic activity orientation type is the cluster to which 29.4% of the baby boomers belong. They participate in income activity, but don't participate in civic-group activity, educational activity, and social activity such as spending time alone. Distribution of priori-and-posteriori baby boomers, distribution of academic background, or monthly household income is moderate level of other clusters. However, unlike other clusters, there are many men. The life satisfaction level is the lowest. Based on result of this study are suggested ways to improve in life satisfaction by social activity type in baby boomers.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.1-16
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• 2000

It is difficult to treat the endodontic apical perforation successfully. In this study, we hypothesized that the application of PDGF-BB and IGF-I into periapical perforation site may accelerate periapical healing and lead to bone deposition. And the specificity of osteonectin in periapical healing was investigated. The experiments were performed on the upper and lower 51 premolar teeth of 4 beagle dogs. The pulp chamber of each tooth was opened and the dental plaque was inserted into the canal for developing the periapical lesion for 5 weeks. Then, the roots were artificially perforated at the apex with the number 4 profile of .06 taper. In each step, standard periapical radiographs were taken to compare the size of lesion each other. The radiographs were scanned and analyzed by image analysis system. The mean and standard deviation of periradicular radiolucency ratios were calculated in each group. ANOVA was used for comparison. 51 premolars were grouped into 3 groups; control group, calcium hydroxide-treated group and calcium hydroxide plus growth factors-treated group. In the control group, the apical perforations were not sealed and obturated with gutta-percha and ZOE sealer by lateral condensation technique. In the experimental groups, the apical perforation were sealed with calcium hydroxide and with/without $4{\mu}g$ of PDGF-BB & IGF-I in cellulose gel and obturated by lateral condensation technique. Fluorescent bone markers were used to measure new bone formation. Following 2, 4, 12 weeks after experiment the dogs were sacrificed and histologic sections were prepared. Each tooth block including periapical lesion was sectioned mesiodistally. One half of the sections were decalcified with 6% nitric acid and processed by standard paraffin embedding technique. The sections were stained by hematoxylin and eosin, and immunostained for osteonectin. Histomorphometrical measurement of neoformed bone was performed using a light microscope. And the other half of the sections were prepared by undecalcified preparation, and confocal laser scanning microscopic investigations were done.

• Journal of KIISE:Information Networking
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• v.30 no.4
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• pp.559-571
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• 2003

ENUM(tElephon NUmbering Mapping) is protocol that brings convergence between PSTN Networks and IP Networks using a unique worldwide E.164 telephone number as an identifier between different communication infrastructure. The mechanism provides a bridge between two completely different environments with E.164 number; IP based application services used in PSTN networks, and PSTN based application services used in IP networks. We propose a new way to organize and handle ENUM Tier 2 name servers to improve performance at the name resolution process in ENUM based application service. We build an ENUM based network model when NAPTR(Naming Authority PoinTeR) resource record is registered and managed by area code at the initial registration step. ENUM promises convenience and flexibility to both PSTN and IP users, yet there is no evidence how much patience is required when users decide to use ENUM instead of non-ENUM based applications. We have estimated ENUM response time, and proved how to improve performance up to 3 times when resources are managed by the proposed mechanism. The proposition of this thesis favorably influences users and helps to establish the policy for Tier 2 name server management.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.475-482
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• 2020

For electronic paper displays using electrophoresis, the response time and reflectivity of the image panel fabricated by filtering are analyzed. For the filtering process, a square wave and ramp wave are applied to white charged particles with a unique q/m value. We divide the sample panels into #1 to #4 according to the applied waveform in the filtering process. Step waves comprising two steps are used to drive the panel; therefore, we divide the driving conditions into D1~D4. The applied voltage at the first stage of the half cycle of the driving waveform moves the charged particles attached via the image force from the electrode, and the applied voltage at the second stage moves the floating charged particles by detaching. As mentioned, four types of driving conditions (D1 to D4) classified according to the half cycle of the driving waveform are applied to the samples #1 to #4), which are classified according to four types of filtering process. When driving condition D1 is applied to the four types of sample panels, the rise time of #1 is 1.59s, #2 is 1.706s, #3 is 1.853s, and #4 is 1.235s, resulting in #4 being relatively faster compared with other sample panels, and showing the same trend in other driving conditions. As a result, we confirm that applying the driving condition D1 causes abrupt movement of the white charged particles injected into the cell. When the same driving waveform (D1) is applied to each sample, reflectivities of 32.1% for #1, 31.4% for #2, 27.9% for #3, and 63.4% for #4 are measured. From the experiment, we confirm that the driving condition D1 (1s of 3.5 V, 9s of 3.0 V) and ramp wave #4 in filtering are desirable for good reflectivity and response time. Our research is expected to contribute to the improvement of the filtering process and optimization of the driving waveform.