• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1276-1281
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• 2007

This study examined the procedures and legal issues for introduction and current Salary-structures and methods for system introductions centered around Seoul Metro which is railway related public company along with the background on introducing Salary-peak system and national/international situations according to the changes in paradigms. Base on these, the study deduced presented plans for improving corporate competitiveness by the introduction of Salary-peak system such as target for applications and ages for Salary-peak and the rate of fall, plans for adjusting duties to present optimum plans according to the introduction of Seoul Metro Salary-peak System.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.208-211
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• 2009

To reduce the peak demand the promotion of gas cooling(absorption chillers and GHPs) is required. In this study the effect of electric power peak-cut has been analyzed using two methods. One is based on monthly LNG consumption data and the other is using the gas cooling capacity installed. Both methods agreed well with each other within the uncertainty of 20%. It was found that the gas cooling had the peak cut effect of 1,500-2,000 MW for recent 5 years (2003 - 2007). The ratio of gas cooling to the whole cooling demand was 12-15%, which is needed to be increased.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.154-159
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• 2011

As the need for predicting the flood stage of river from torrential downpouring caused by climate change is increasingly emphasized, the study, centered on the area of Gangwon-do Inje-gun and Jeongseon-gun of local river, is to develop peak water level regression equation by rainfall. Through the correlation between rainfall and peak water level, it is confirmed that rainfall according to duration and peak water level have a high correlation coefficient. Based on this, a relational expression of rainfall and peak water level is verified and then the adequacy of the calculated expression is analyzed and the result shows that a very accurate prediction is not easy to achieve but a rough prediction of the change of water level at each point is possible.

• Journal of Magnetics
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• v.2 no.4
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• pp.111-115
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• 1997

The electronic structure of the Kondo insulator CeNiSn has been investigated by using photoemission spectroscopy. A satellite feature is observed in the valence band spectrum about 6 eV below the Ni 3d main peak, indicating a strong Ni 3d Coulomb correlation in CeNiSn. The Ce 4f partial spectral weight exhibits three peak structures, including one due to the 4f1\longrightarrow4f0 transition, another near EF, and the other which overlaps the Ni 3d main peak. We interpret the peak near EF as reflecting mainly the Ce 4f/Sn 5p hybridization, whereas that around the ni 3d main peak as reflecting both the Ce 4f/Ni 3d and Ce 5d/Ni 3d hybridization. Yield measurements across the 4d\longrightarrow4f threshold indicate the Ce valence to be close to 3+. The prominent Fermi edge suggests a metallic ground state in CeNiSn.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.841-849
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• 2014

Urban railway with rectifiers is connected by parallel circuits because substations are joined by the power rail. Thus, if an input voltage of a substation is increased, then the voltage of rectifiers is also increased, and which leads to an increase in the peak power of the substation. To solve this problem, this paper proposes a new method reducing the peak power of substations by adjusting the operation number of rectifiers. Its feasibility is exemplified by some simulations performed for Incheon subway Line 1 and GA(Genetic Algorithm) method has been applied to obtain the optimal input. Simulation results show that peak power can significantly be reduced using the method proposed in this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.62-68
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• 2014

We proposed a series connection-type superconducting fault current limiter(SFCL) using E-I core that can prevent the internal magnetic flux generation of cores during normal operation, and prevent the saturation of cores due to a sudden magnetic flux generation at the initial stage of fault occurrence while limiting the peak current. Through a short-circuit simulation experiment, we analyzed the operating status of the two superconducting elements and limiting characteristics according to the size of the fault current peak before and after the failure. Further, the double peak current limiting characteristics according to the winding directions as well as the current and the voltage of each coil were compared and analyzed.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.150-151
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• 2012

The utility grid has a supply of electric energy which is larger than the usually required power consumption under peak load condition. So, power distribution is required to have a heavy capacity because of peak-load period. To solve the problem, this paper proposes a 10kW rapid charger system which has a function of load compensation at the peak-load condition. The proposed system supplies power demanded by peak-load through transferring energy in the battery of electric vehicle to the grid. V2G operation is verified through simulation performed by 10kW rapid-charger.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.502-506
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• 2013

The cash flow forecasting is normally done by contractors in construction industry at early stages of the project for contractual decisions. The decision making in such situations involve uncertainty about future cash flows and assessment of working capital requirements gains more importance in projects constrained by cash. The traditional approach to assess the working capital requirements is deterministic in and neglects the uncertainty. This paper presents an alternate approach to assessment of working capital requirements for contractor based on fuzzy set theory by considering the uncertainty and ambiguity involved at payment periods. Statistical methods are used to deal with the uncertainty for working capital curves. Membership functions of the fuzzy sets are developed based on these statistical measures. Advantage of fuzzy peak working capital requirements is demonstrated using peak working capital requirements curves. Fuzzy peak working capital requirements curves are compared with deterministic curves and the results are analyzed. Fuzzy weighted average methodology is proposed for the assessment of peak working capital requirements.

• Journal of Korean Physical Therapy Science
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• v.7 no.1
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• pp.377-396
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• 2000

After warming-up exercise for 20 minutes, Isokinetic measurement of trunk strength for flexor and extensor was done by using Cybex 6000 TEF Unit on 91 healthy male white workers from 22years old to 49 years old, and compared each other. 20 repetitions of trunk extension-flexion were done at $120^{\circ}$/sec angular velocity. After resting for 1 minutes, Four repetitions at two different angular velocities($60^{\circ}$/sec, $120^{\circ}$/sec) were done with 30 seconds of resting interval between each angular velocity. The purpose of this study is to obtain the isokinetic normative strength values for trunk extensors and flexors, and is to know the correlation between age, height, weight of subjects and data from isokinetic trunk strength measurement, and is to provide a guideline for exercise program of male white collar workers The collected data were analyzed by ANOVA, Duncan's Multiple Range Test, and Pearson correlation coefficiency in PC-SAS program. The results obtained were as follow; 1. There is significant positive-correlation with the statistic value between weight and peak torque of trunk muscles at two different angular velocities($60^{\circ}$/sec, $120^{\circ}$/sec)(p<01), between height and peak torque of trunk muscles at two different angular velocities($60^{\circ}$/sec, $120^{\circ}$/sec) except peak torque of trunk flexor at $60^{\circ}$/sec(p<01). 2. There is nagitive-correlation between age and peak torque of trunk muscles at two different angular velocities($60^{\circ}$/sec, $120^{\circ}$/sec), there is significant differences with statistic value between age and peak torque of trunk extensor at $120^{\circ}$/sec(p<.01). 3. Mean peak torque and mean peak torque % by body weight of trunk extensor is 1.1 times higher values than trunk flexor at $60^{\circ}$/sec. 4. There is the increase in peak torque angle of trunk flexor with increasing of age, and the decrease in peak torque angle of trunk flexor with increasing of age at two different angular velocities($60^{\circ}$/sec, $120^{\circ}$/sec). there is significant differences with statistic value in peak torque angle of trunk flexor at $120^{\circ}$/sec(p<.01). 5. There is significant decrease in endurance ratio of trunk extensor with increasing of age at $120^{\circ}$/sec(p<.01). In conclusion, peak torque of trunk extensor is 1.1 times higher values than trunk flexor in healthy male white collar workers.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.2
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• pp.67-74
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• 2008

This paper proposes two peak-windowing algorithms for peak-to-average power reduction(PAPR) of orthogonal frequency division multiple access(OFDMA) downlink systems. The Proposed algorithms mitigate the effect of excessive suppression due to successive peaks or relatively high peaks of the signal. First, multi-stage peak windowing algorithm is proposed, which exploits multiple threshold of target PAPR in order to step down the peaks gradually. Secondary, variable-length peak windowing algorithm is proposed, which adapts the window length with respect to the existence of successive peaks within a half of window length. Therefore, the proposed method reduces the distortion of signal amplitude caused by window overlapping. The proposed algorithms outperform the conventional peak windowing with the aid of window-length adaptation or sequential peak power reduction. Simulation results show the efficiency of the proposed algorithms over OFDMA downlink systems, especially WiBro systems.