• Korean Journal of Optics and Photonics
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• v.5 no.4
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• pp.473-480
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• 1994

We have applied nonlinear interferometry of coherent anti-Stokes Raman spectroscopy (CARS) to measure the nonresonant third order susceptibilities of various gases. For the experiment, we placed two gas cells serially and filled the first cell with argon as a calibration standard and the second cell with gases under test. The interference fringes of the CARS signals generated in the two gas cells were obtained by changing the thickness of the phase shifting unit which was made of BK-7 glass. The total effective nonresonant susceptibilities were determined from the measured amplitudes of the interference fringes of the CARS signals of the gases. The nonresonant susceptibilities were obtained by subtracting off resonant vibrational contributions from the total effective susceptibilities. The results of this work are compared with the published data and the overall uncertainty is estimated to be less than 5%. an 5%.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.183-192
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• 2014

This paper proposes a payment-based power control scheme using non-cooperative game with a novel pricing function in cognitive radio networks (CRNs). The proposed algorithm considers the fairness of power control among second users (SUs) where the value of per SU' signal to noise ratio (SINR) or distance between SU and SU station is used as reference for punishment price setting. Due to the effect of uncertainty fading environment, the system is unable to get the link gain coefficient to control SUs' transmission power accurately, so the quality of service (QoS) requirements of SUs may not be guaranteed, and the existence of Nash equilibrium (NE) is not ensured. Therefore, an alternative iterative scheme with sliding model is presented for the non-cooperative power control game algorithm. Simulation results show that the pricing policy using SUs' SINR as price punishment reference can improve total throughput, ensure fairness and reduce total transmission power in CRNs.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.697-706
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• 2020

This study investigates the relationship between related loan, ownership concentration and real estate firm performance. The data was collected from 35 real estate firms listed on Indonesia Stock Exchange from 2007 to 2012. Related loans are viewed from the angle of related lending and loan. Related lending and loan is measured by the related lending on total lending ratio and related loan on total loan ratio. Firm performance is measured by the asset turnover ratio and return on assets ratio. Ownership concentration is measured by the right cash flow. The data analysis was done with regression analysis and panel data. The results of the study found that related loans had a positive effect on sales but had no effect on profits. This supports the efficient transaction hypothesis. On the other hand, related lending has a positive effect on profits that supports opportunistic transactions. Ownership concentration moderates the effect of related loan on company's performance. The related lending are beneficial for mutually supporting activities in the real estate sector business group in Indonesia, but related loans have the potential to be used in tunneling activities. The paper contributes to the related party transaction in benefits-risks of related lending and related loan in uncertainty context.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.689-694
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• 2004

To increase accurateness and reliability of the evaluation of power tool vibration transmitted to an operator, it is necessary to measure grip and feed forces during the measurement of hand-transmitted vibration. In the study a system was invented to measure the vibration and the grip and/or feed force, which consists of a measurement handle and a PC with data acquisition system and the software. Strain gauges and an accelerometer were mounted on the handle for the simultaneous measurement of the forces and the vibration. The program in the system makes it possible to monitor the grip and feed force during the tool operation so that the operator keeps the applying forces within the pre-determined range. Investigating the vibration total values, frequency-weighted root mean square accelerations at the handle, obtained at various conditions with control of the grip and feed force showed more consistency than those measured without force control. By using the system the experimenter can reduce uncertainty of the measured vibration.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1968-1976
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• 2007

This paper proposes a hybrid pseudo-noise (PN) code acquisition scheme for Multicarrier Direct Sequence - Code Division Multiple Access (MC DS-CDMA) mobile communication systems on the code acquisition performance for Nakagami-m fading channel. The hybrid acquisition scheme combines parallel search with serial search to cover the whole uncertainty region of the input code phase. It has a much simpler acquisition hardware structure than the total parallel acquisition and can achieve the mean acquisition time (MAT) slightly inferior to that of the total parallel acquisition. The closed-form expressions of the detection and false-alarm probabilities are derived.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1579-1587
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• 2022

The effects of hydride amount (20-850 wppm), orientation (circumferential and radial), and temperature (room temperature, 100 ℃, 200 ℃) on the axial mechanical properties of Zircaloy-4 cladding were comprehensively examined. The fraction of radial hydride fraction in the cladding was quantified using PROPHET, an in-house radial hydride fraction analysis code. Uniaxial tensile tests (UTTs) were conducted at various temperatures to obtain the axial mechanical properties. Hydride orientation has a limited effect on the axial mechanical behavior of hydrided Zircaloy-4 cladding. Ultimate tensile stress (UTS) and associated uniform elongation demonstrated limited sensitivity to hydride content under UTT. Statistical uncertainty of UTS was found small, supporting the deterministic approach for the load-failure analysis of hydrided Zircaloy-4 cladding. These properties notably decrease with increasing temperature in the tested range. The dependence of yield strength on hydrogen content differed from temperature to temperature. The ductility-related parameters, such as total elongation, strain energy density (SED), and offset strain decrease with increasing hydride contents. The abrupt loss of ductility in UTT was found at ~700 wppm. Demonstrating a strong correlation between total elongation and offset strain, SED can be used as a comprehensive measure of ductility of hydrided zirconium alloy.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.3
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• pp.276-285
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• 2010

Recently the Korean government has tried to cut down the $PM_{10}$ concentration by the Special Law for Air Quality Improvement. But the concentrations of $PM_{10}$ have exceeded the air quality standard at most monitoring stations. Primary $PM_{10}$ emitted from various sources and emission data have large uncertainty. The biomass burning is one of the major sources of $PM_{10}$ emission. The biomass burning is composed of wood stove usage, meat cooking and agricultural combustion etc.. Activity data and emission factors for the biomass burning are limited, and it is hard to calculate the air pollution emissions from these sources. In this study, we tried to estimate the air pollution emission from residential wood stove usage. The number of total wood stoves is estimated by the survey of wood stove manufacturer. And air pollution emission factors for the wood stove are investigated using the flue gas measurement by U.S. EPA particulate test method (Method 5G). As the results, the $PM_{10}$ and CO emission factors of wood stove are estimated as 7.7 g/kg-wood and 78.8 g/kg-wood respectively. The annual $PM_{10}$ and CO emissions from wood stove are calculated as 1,200~3,600 ton/year and 12,600~36,400 ton/year in Korea. It is confirmed that wood stove is the one of major sources of biomass burning, and the survey for activity data and the measurement for emission factors are needed for reducing the uncertainty of these emission data.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1473-1479
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• 2013

Entropy is a measure of disorder or uncertainty. This terminology is qualitatively used in the understanding of its correlation to pollution in the environmental area. In this research, three different entropies were defined and characterized in order to quantify the qualitative entropy previously used in the environmental science. We are dealing with newly defined distinct entropies $E_1$, $E_2$, and $E_3$ originated from Shannon entropy in the information theory, reflecting concentration of three major green house gases $CO_2$, $N_2O$ and $CH_4$ represented as the probability variables. First, $E_1$ is to evaluate the total amount of entropy from concentration difference of each green house gas with respect to three periods, due to industrial revolution, post-industrial revolution, and information revolution, respectively. Next, $E_2$ is to evaluate the entropy reflecting the increasing of the logarithm base along with the accumulated time unit. Lastly, $E_3$ is to evaluate the entropy with a fixed logarithm base by 2 depending on the time. Analytical results are as follows. $E_1$ shows the degree of prediction reliability with respect to variation of green house gases. As $E_1$ increased, the concentration variation becomes stabilized, so that it follows from linear correlation. $E_2$ is a valid indicator for the mutual comparison of those green house gases. Although $E_3$ locally varies within specific periods, it eventually follows a logarithmic curve like a similar pattern observed in thermodynamic entropy.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.1
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• pp.37-53
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• 2012

There is considerable uncertainty in ground properties used in tunnel designs. In this study, a back analysis was performed to find optimal ground properties based on the artificial neural network facility of MATLAB program of using tunnel monitoring data. Total 81 data were constructed by changing elastic modulus and coefficient of lateral pressure which have great influence on tunnel convergence. A sensitivity analysis was conducted to establish an optimal training model by varying the number of hidden layers, the number of nodes, learning rate, and momentum. Meanwhile, the optimal training model was selected by comparing MSE (Mean Squared Error) and coefficient of determination ($R^2$) and was used to find the correct elastic moduli of layers and the coefficient of lateral pressure. In future, it is expected that the suggested method of this study can be applied to determine the optimum tunnel support pattern under given ground conditions.

• Journal of Information Technology Applications and Management
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• v.15 no.3
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• pp.195-208
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• 2008

In an emergency management case, evaluating the economic value of information technology investments is a challenging problem due to the effects of decision making, uncertainty of disasters, and difficulty of measurements. Risk assessment and recovery process, one of the major functions in emergency management, consists of (1) measurement of damages or losses, (2) recovery planning, (3) reporting and approving budgets, (4) auctioning off recovery projects to constructors, and (5) construction for the recovery. Specifically and of our interest, measurement of damages or losses is often a costly and time-consuming process because the wide range of field surveys should be performed by a limited pool of trained agents. Managers, therefore, have to balance accuracy of the field survey against the total time to complete the survey. Using information technologies to support field survey and reporting has great potential to reduce errors and lowers the cost of the process. However, existing cost benefit analysis framework may be problematic to evaluate and justify the IT investment because the cost benefit analysis often include the long-run benefit of IT that is difficult to quantify and overlook the impact of managerial control upon the investment outcomes. Therefore, we present an alternative cost-centric control model that conservatively quantifies all cost savings to replace benefits in cost benefit analysis and incorporate the managerial control. The model provides a framework to examine how managerial decision making and uncertainty of disaster affect the economic value of IT investments. The current project in Emergency Agency in South Korea is introduced as a case to apply the cost-centric control model. Our work helps managers to better evaluate and justify IT-related investment alternatives in emergency management.