• Journal of the Korea Institute of Building Construction
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• v.17 no.6
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• pp.577-585
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• 2017

HPC method is developing to improve the constructability and structural performance of the existing PC method. The objective of this study is to develop construction procedures and to analysis of construction period for HPC method. In order to develop construction procedures, the building construction data of the existing half-slab method was analyzed. Analyzing design drawings and specifications of nine construction cases, a prototype of half-slab method, was drawn. Applying the core technology of HPC method to the drawn prototype of half-slab method, a prototype of HPC method, was developed. The differences of both methods were 'installing PC column' and 'placing topping concrete'. To analysis the differences of both methods, seven construction cases were analyzed. According to the analysis for HPC method, cases1 and 2 had columns divided for construction shortened about 16% of a construction period. The schedule of column assembly work was analyzed to be shortened much. That is judged to be because the use of a hollow PC column leads to a decrease in the number of columns. In particular, if HPC method is applied to a building construction site using large columns, it is analyzed to shorten a construction period more than the existing Half-slab method.

• Earthquakes and Structures
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• v.3 no.1
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• pp.17-35
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• 2012

Simplified equations for fundamental period of vibration of skeletal structures provided by most seismic design provisions suffer from the absence of any associated confidence levels and of any reference to their empirical basis. Therefore, such equations may typically give a sector of designers the false impression of yielding a fairly accurate value of the period of vibration. This paper, although not addressing simplified codes equations, introduces a set of mathematical equations utilizing the theory of error propagation and First-Order Second-Moment (FOSM) techniques to determine bounds on the relative error in theoretically calculated fundamental period of vibration of skeletal structures. In a complementary step, and for verification purposes, Monte Carlo simulation technique has been also applied. The latter, despite involving larger computational effort, is expected to provide more precise estimates than FOSM methods. Studies of parametric uncertainties applied to reinforced concrete frame bents - potentially idealized as SDOF systems - are conducted demonstrating the effect of randomness and uncertainty of various relevant properties, shaping both mass and stiffness, on the variance (i.e. relative error) in the estimated period of vibration. Correlation between mass and stiffness parameters - regarded as random variables - is also thoroughly discussed. According to achieved results, a relative error in the period of vibration in the order of 19% for new designs/constructions and of about 25% for existing structures for assessment purposes - and even climbing up to about 36% in some special applications and/or circumstances - is acknowledged when adopting estimates gathered from the literature for relative errors in the relevant random input variables.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.271-276
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• 2006

Railroads made many contribution to modernization being developed so quickly as public transportation, but after middle of 20 century, its qualities are getting low because of focusing on the investment and development of cars and airplanes. Its role which is getting the excellent merits on the mass transportation, rapid transit. safety, state period, energy efficiency, and prevention of environmental pollution has been reconsidered. Element of horizontal alignment In an existing railroad line is needed as basic materials, when it will be improved or moved. If its design drawing was lost or damaged, it is impossible to recover. It is riot easy to repair for it as disasters. We must understand an existing railroad line to bring a function included a basic geography situation. In this studies we acquire, analyze. and handle the digital picture of railroads and then reappear shape of three dimension. But also we want to contribute to establish the facilities information choosing materials of existing railroad line in outputting the alignment element by reverse.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1328-1332
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• 2010

The enlargement of existing tunnels is required to cope with problems related to traffic congestion. Sometimes, the tunnel traffic must be maintained through existing tunnels during their reconstruction due to non-availability of detours. And excavation by drill and blasting is desired for widening a hard rock tunnel. In this case, the road must be closed for some period for blasting through analyzing of traffic volume. In this paper, a case study on some traffic countermeasures for tunnel enlargement by blasting was performed. And the traffic flow characteristics of some tunnels in domestic main city were analyzed.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.148-154
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• 2000

To do this study, we produced cooling vest newly. Rectal temperature was ascended approximately from 37.2$^{\circ}C$ to 38.05$^{\circ}C$ in lab, but wearing cooling vest, the temperature was descended 0.2 while wearing developed product compare with existing product. Mean skin temperature which was showed distribution from 32.8∼36.5$^{\circ}C$, it was descended 1.0∼1.1$^{\circ}C$, while wearing cooling vest and comparing with existing product, wearing developed product was lower 0.5$^{\circ}C$, While wearing developed product, it was found that they had lower tendency than exiting product. Specifically in case of temperature within clothing(chest) 0.2∼2.0$^{\circ}C$ in case of humidity within clothing 2∼8% RH. Facts from above we confirmed that clothing microclimate had been improved and space was happened between body and garment in order to control. In subjective sensation, existing product made negative response during experiment period from participants, but developed product was nearing to comfortable area.

• International Journal of Control, Automation, and Systems
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• v.6 no.1
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• pp.44-53
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• 2008

An interacting multiple model (IMM) estimation algorithm based on the mixing of the predicted state estimates is proposed in this paper for a right continuous jump-linear system model different from the left-continuous system model used to develop the existing IMM algorithm. The difference lies in the modeling of the mode switching time. Performance of the proposed algorithm is compared numerically with that of the existing IMM algorithm for noisy system identification. Based on the numerical analysis, the proposed algorithm is applied to target tracking with a large sampling period for performance comparison with the existing IMM.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.109-112
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• 2006

In this study, an approach that installs seismic isolation bearings was proposed for the seismic retrofit of the existing bridges. The method that replaces all existing bearings with seismic isolators was proposed already. However, in this study, we recommend to utilize the existing bearings for the benefit of safety and cost. According to our proposal, the seismic isolators do not support vertical loads but they just function as the period shifter and the horizontal damper. To verify this approach experimentally, the real scale bearings and isolators for the real highway bridges were designed and fabricated. And the responses of this isolated bridges to the assumed earthquakes were determined by the pseudo dynamic test scheme. The test results were also compared to the responses computed by the well known structural analysis software to check the reliability of the test. From the test results, we found that the retrofitted bridges using the proposed method showed stable performances under earthquakes.

• Proceedings of the KIEE Conference
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• summer
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• pp.1187-1189
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• 2004

This paper presents a boost circuit topology driving in high - frequency. It solves the problem which arised from hard-switching in high-frequency using a period of resonant circuit and operating under the principle of ZCS turn-on and ZCZVS turn-off commutation schemes. In the existing circuit, it has the high voltage stress in free-wheeling diode. But in the proposed circuit, it has voltage stress which is lower than voltage stress of existing circuit with modifing a location of free-wheeling diode. In this paper, it explained the circuit operation of each mode and the waveform of each mode. Also the experiment result compares the existing voltage stress of free-wheeling diode with the proposed voltage stress of that.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1993.10a
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• pp.107-110
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• 1993

This paper presents the technical requirements and configuration of power demand control system in office building Generally, the peak power demand is occurred in cooling period. For power demand control in existing building, the most effective control points are the motors for air handling units.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.10
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• pp.843-848
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• 2001

Most of gimballed inertial navigation systems(GNIS) are calibrated periodically to maintain their inherent accuracy. The existing calibration techniques using the conventional schuler test with the least square method and the multiposition test take a long time and have some problems in procedures. To solve this problem, calibration method using a linear Kalman filter is proposed by us. In this paper, the calibration method by the change of Schuler period is studied in order to improve the calibration performance of the gimballed INS. First of all, it is shown that the observability of Kalman filter is also enhanced the Schuler period is decreased. Simulation results show that the calibration performance using the present scheme is improved according to the decrease of the Schuler period and the calibration time is shortened extremely, too. And our proposed technique shows desirable estimation performance for the g-sensitive errors of inertial sensors in particular.