• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.175-184
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• 2008

Uncertainties are unavoidable in engineering applications. In this paper we propose an alpha reliable multi-variable network design problem under demand uncertainty. In order to decide the optimal capacity enhancement, three performance measures based on 3E(Efficiency, Equity, and Environmental) are considered. The objective is to minimize the total budget required to satisfy alpha reliability constraint of total travel time, equity ratio, and total emission, while considering the route choice behavior of network users. The problem is formulated as the chance-constrained model for application of alpha confidence level and solved as a lexicographic optimization problem to consider the multi-variable. A simulation-based genetic algorithm procedure is developed to solve this complex network design problem(NDP). A simple numerical example ispresented to illustrate the features of the proposed NDP model.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.1 s.343
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• pp.37-44
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• 2006

This paper proposes an interconnect delay fault test (IDFT) solution on boards and SoCs based on IEEE 1149.1 and IEEE P1500. A new IDFT system clock rising edge generator which forces output boundary scan cells to update test data at the rising edge of system clock and input boundary scan cells to capture the test data at the next rising edge of the system clock is introduced. Using this proposed circuit, IDFT for interconnects synchronized to different system clocks in frequency can be achieved efficiently. Moreover, the proposed IDFT technique does not require any modification of the boundary scan cells or the standard TAP controller is simple in terms of test procedure and is small in terms of area overhead.

• Korean Business Review
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• v.19 no.1
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• pp.115-136
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• 2006

Most countries that use a Value Added Tax(VAT) have exception for special cases with small enterprises who lack the ability to adapt in tax laws. VAT has been the most important tax. The simplified taxation system under VAT was introduced for small business taxpayers to perform tax liability easily and for government and taxpayers to get administrative efficiency by using a simple procedure. The present thesis suggests the conversion of simplified taxation system into general taxation as its improvement plan. That is, to abolish simplified taxation system, to convert it into general taxation and to apply the same tax base. The principle of fair taxation is not only important to realize tax justice, but also the principle of administrative efficiency important to increase the level of convenience for small enterprise taxpayers and efficiency for tax authorities.

• Journal of the Korean Chemical Society
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• v.39 no.3
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• pp.186-190
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• 1995

A simple procedure, readily available at low cost with a sensitivity sufficient to determine trace levels of iron in seawater is proposed, which utilizes adsorptive accumulation of the iron/catechol complex on the mercury drop electrode in a borate medium of pH 8.0. Optimal conditions include a solution concentration of 2 mM catechol, 2.5 mM borate and a pH of 8.0, an accumulation potential of - 0.25 V is applied for 1∼3 min, and the potential scan is in the differential pulse mode. The limit of detection is 1.5 nM Fe using a preconcentration time of 3 min. The interference from copper can be eliminated and baseline slope is greatly improved, because its peak is well separated from that of iron in the proposed medium.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.2
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• pp.75-84
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• 2010

An in-cabinet response spectrum should be generated to perform the seismic qualification of devices and instruments mounted inside safety-related electrical equipment installed in nuclear power plants. The response spectrum is available by obtaining accurate seismic responses at the device mounting location of the cabinet. The dynamic behavior of most of electrical equipment may not be easily analyzed due to their complex mass and stiffness distributions. Considering these facts, this study proposes a procedure to estimate the seismic responses of a structure by a combination of a test and subsequent analysis. This technique firstly constructs the modal equations of the structure by using the experiment modal parameters obtained from the impact test. Then the seismic responses of the structure may be calculated by a mode superposition method. A simple steel frame structure was fabricated as a specimen for the validation of the proposed method. The seismic responses of the specimen were estimated by using the proposed technique and compared with the measurements obtained from the shaking table tests. The study results show that it is possible to accurately estimate the seismic response of the structure by using the experimental modal parameters obtained from the impact test.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.7
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• pp.42-49
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• 1999

In this paper, we proposed a simple measurement method to find the behaviors of the fiber-to-waveguide coupler. The polished fiber blocks and planar waveguides on silicon dioxide were fabricated independently and then optically coupled by physical pressure. Several kinds of polymer with different refractive indices were used for waveguide films. The proposed method makes it possible to measure the center wavelength, bandwidth, extinction ratio, and polarization dependence of the coupler during fabrication procedure. The wavelength sensitivity increased with refractive index of polymer. The symmetric planar waveguide structure and isotropic property of guiding materials reduced polarization dependent property. Insertion loss of the coupler was less than 0.5dB. It is expected that our measurement method is useful for developing various optical devices using evanescent coupling between polished fiber and planar waveguide such as optical modulators and filters etc.

• Geotechnical Engineering
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• v.14 no.6
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• pp.33-44
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• 1998

Preliminary study has been conducted to analyse the co-relation between shallow landslides frequently occurring in rainy seasons and the water infiltration into the slope. The change of stress state due to partial saturation of a soil and hence the reduction of its shear strength have been reviewed. The variation of the safety factor of an infinite planar slope in accordance with various water infiltration scenarios has been estimated by limit equilibrium method to explain the mechanism of shallow slope failure. Numerical analysis under the same condition as those of some models dealt with in the previous method has been carried out by using FLAC, a finite difference program, and the results have been compared with the ones obtained by limit equilibrium method. Both results proved to be identical, which implies the ability of the numerical approach to the problems related to the stability analysis of unsaturated slope with the irregular geometry. Further improvement, however, should be made to apply the present analysis procedure to general slopes since it deals with a simple one.

• Journal of Environmental Health Sciences
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• v.20 no.4
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• pp.80-89
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• 1994

It was reported that BCF's (Bioconcentration Factor) on Carbaryl and BPMC in concentration of 1, 2, 5 and 10 ppm, previously. Carassius auratus(goldfish) was chosen as test organism. Carbamates in fish and in test water were extracted with n-hexane and acetonitrile. GC-ECD was used to detecting and quantitating of Carbamates. Also, partition coefficients were determined with Stir flask method. To evaluate environmental toxicological profiles of tested compounds, experimental concentration were 0.05, 0.1 and 0.5 ppm in contrast to previous report. It was considered that higher BCFs of BPMC due to its higher partition coefficient compared to Carbaryl. The obtained results were as follows: 1. It was possible to determine short term BCF of Carbaryl and BPMC through relatively simple procedure in environmental concentrations. 2. BCF$_3$ of Carbaryl in concentration of 0.05, 0.1 and 0.5 ppm were 4.666 $\pm$ 0.002, 3.622 $\pm$ 0.004, 1.200 $\pm$ 0.002 and BCF$_5$ were 3.897 $\pm$ 0.005, 4.219 $\pm$ 0.017 and 1.186 $\pm$ 0.054, respectively. In the case of BPMC in same condition, BCF$_3$ were 4.077 $\pm$ 0.014, 4.900 $\pm$ 0.005, 4.750 $\pm$ 0.009 and BCF$_5$ were 3.465 $\pm$ 0.010, 4.612 $\pm$ 0.011 and 4.075 $\pm$ 0.012, respectively. 3. Carbaryl concentration in fish extract was increased as increasing test concentration, but BCF were decreased as prolonging test period, especially dropped at 0.5 ppm. 4. In the case of BPMC, BCF were decreased as increasing test concentration, but the concentration in fish extract of 3-day test group was slightly higher than that of 5-day test group. 5. Higher BPMC concentration in fish extract was due to its higher partition coefficient to compared with Carbaryl. 6. Determined logP of Carbaryl and BPMC were 2.200 and 3.180. But the calculated BCF using suggested equation was so different that predict BCF. It is suggested that BCF's of Carbamates have to be determined by experiment.

• Korean Journal of Construction Engineering and Management
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• v.11 no.2
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• pp.25-34
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• 2010

The building construction projects include a variety of risk factors due to uncertainties. To succeed in the projects, it is important how risks are managed. Risk management is composed of identification, analysis and response. Especially, the risk analysis is important to objectively calculate significance of risk factors. This paper evaluates a method to find priorities of risks using the AHP(Analytic Hierarchy Process). The method has some defects; (1) the consistency becomes weak as the number of pair-wise compared risks is large, and (2) the input and output procedures are complex when risks are added to or removed from a risk database. Thus the paper adopts the PROMETHEE(Preference Ranking Organization METHod Enrichment Evaluations) analysis process which is able to overcome the limitation of the AHP restricted to 9 risk factors. The PROMETHEE makes the procedure of risk analysis simple, when the risk factors pull out and put in the risk database. The purpose of this study is to provide process of risk analysis to use the PROMETHEE.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.2-17
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• 1999

Interpolated second order polynomials(ISOP's) are proposed to design efficient cascaded integrator-comb(CIC)-based decimation filters for a programmable downconverter. It is shown that some simple ISOP's can effectively reduce the passband droop caused by CIC filtering with little degradation in aliasing attenuation. In addition, ISOP's are shown to be useful for simplifying halfband filters that usually follow CIC filtering. As a result, a modified half band filter(MHBF) is introduced which is simpler than conventional halfband filters. The proposed decimation filter for a programmable downconverter is a cascade of a CIC filter, an ISOP, MHBF's and a programmable finite impulse response(FIR) filter. A procedure for designing the decimation filter is developed. In particular, an optimization technique that simultaneously designs the decimation filter is developed. In particular, an optimization technique that simultaneously designs the ISOP and programmable FIR filters is presented. Design examples demonstrate that the proposed method leads to more efficient programmable downconverters than existing ones.