• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.921-926
• /
• 2000

Recently, in construction field, large construction equipment are used to reduce the construction schedule and labor cost. Therefore, construction vibration has caused much annoyance and that induced from operating of large construction equipment, has become a major problem for a number of dwellers in nearby construction field and it has become a very serious issue in our living environment. In this point, this study attempts to survey on the characteristics of piling vibration by oil pressure method in construction field. And this study intends to get the basic data to establish a standard about construction vibration.

• Journal of the Korean housing association
• /
• v.7 no.2
• /
• pp.99-107
• /
• 1996

Recently, construction noise has caused much annoyance for a number of dwellers in nearby construction field and has become a very serious issue in our living environment. Therefore in our country, a practical solution and better method of reducing construction noise are highly required. Practical solutions for the construction noise, however, are very difficult because the poorness of basic data and insufficiency of the existing research. In this point, this study attempts to surveys the subkective response of construction machine noise in construction field. And this study intends to get the basic data for establishment of a standard about construction noise.

• Proceedings of the Korean Society for Quality Management Conference
• /
• 2009.10a
• /
• pp.370-376
• /
• 2009

Study of IFI(Integrated Field Innovation) means change of management. This study sill introduces IFI which is a new methodology of change and innovation of workers, and will describe how workers participated in the activities voluntarily. The principle of IFI is that letting employees to find the problems of the sites -anything that makes employees considering as the problem while they are working-and solve those problems through any tools own their own. Workers do not have to waste their time on bounding by unnecessary tools and processes. There are some cases that company "D" has been actually applied the IFI methodology in 2008. By application of IFI methodology to "D" company, which is proved that methodology is good change management program for workers who work in the manufacturing field.

• Journal of KSNVE
• /
• v.10 no.6
• /
• pp.963-970
• /
• 2000

The turbo chiller uses centrifugal compressor, which operates at about 14,500 rpm. Due to the high rpm of the impeller, the noise of chiller males one of the serious problems. The possibility of the sound reduction by using absorbing material is studied in this paper. The generated sound propagates through the duct and then radiates to the outer field. So, the use of sound absorption material inside the duct is one of the effective methods. To study the effect of location of the material, we use Boundary Element Method to analyze the sound field inside the duct system. Numerical study shows the highest sound pressure region is near the elbow of curved duct. From the numerical study, it is also shown that appropriate use of sound absorbing material at this region makes 8dB reduction of the highest noise level.

• Tunnel and Underground Space
• /
• v.8 no.2
• /
• pp.139-145
• /
• 1998

The reliable estimation of the system parameters and the accurate prediction of the system behavior are important to design underground structures safely and economically. Especially, the elastic modulus and the in-situ stresses are very important parameters in predicting the behavior of the underground structure. Therefore, the back analysis using the field measurement data is developed to determine accurately the elastic modulus and the in-situ stresses of the underground structural system in this study. A back analysis using the combined finite and boundary element is developed. It can consider the far field boundary condition and is efficient in computation. In this study, a back analysis is performed to predict behaviors of underground structures for the real construction site. The comparison between the results of the back analysis with field measurement data and the obtained material properties from the field test shows good agreement for the real construction site.

• Proceedings of the KIEE Conference
• /
• 1998.07e
• /
• pp.1809-1811
• /
• 1998

Axial magnetic field restrains arc diffusion that appear at cutting off fault current in vacuum interrupter(VI). In this study, spatial and temporal behavior simulation of arc is carried out for various axial magnetic field. Also the results of this simulation show that axial magnetic field controls and helps to extinguish arcs. This study can be applied to design and analysis of VI. Dymo theory that is not considered in this study will be considered latter.

• Proceedings of the KIEE Conference
• /
• 1998.07e
• /
• pp.1635-1637
• /
• 1998

This paper describes on the basic study for the insulation design of vacuum interrupter using Finite Element Method. For the basic study of insulation design, first, the maximum electric field was calculated on each curvature radius of arc shield and electrode. Second, the maximum electric field was also calculated on applied voltage and end shield with or not. Thus, the maximum electric field calculated have an effect on curvature radius and voltage polarity.

• Journal of the Society of Naval Architects of Korea
• /
• v.46 no.2
• /
• pp.105-113
• /
• 2009

A theoretical study on the pressure fluctuation induced by a propeller was carried out in this study. The main objective of this study is to analyze the source mechanism of the pressure fluctuation induced by propeller sheet cavitation. To analyze the pressure fluctuation induced by propeller sheet cavitation, modern acoustic theory was applied. Governing equation of pressure fluctuation induced by sheet cavitation was derived using Ffowcs Williams proposed time domain acoustic approaches. Several factors affecting pressure fluctuation were analyzed based on the derived governing equation. Pressure fluctuation result was represented by combined results of the far field term and near field term. Finally, the physical mechanism of pressure fluctuation at the blade rate frequency was analyzed using numerically generated cavitation volume variation.

• 한국연소학회:학술대회논문집
• /
• 2013.06a
• /
• pp.107-108
• /
• 2013

An experimental study in the dual swirl burner was conducted to analyze the temperature characteristics in the combustion field. The dual swirl burner consists of a main swirling pre-mixed flame with tangential swirler surrounding a pilot which can stabilize a diffusion flame or a partially premixed flame with vane swirler depending on whether fuel is supplied at the exit plane or further upstream. The purpose of this study is to analyse experimentally the characterization of flame temperature in the reacting zone, specially, according to the various combustor diameters like 80mm, 100mm, 130mm and 150mm(O.D). As a result, the temperatures of combustion field were decreased as the diameter of combustor increased. Therefore, these results can be expected that the larger diameter of combustor tend to emit less NOx emission than the small combustor.

• Journal of the Korean Society of Safety
• /
• v.26 no.3
• /
• pp.34-42
• /
• 2011

Death disaster among the disasters in construction field is mainly occurred by crash, and the work plate is the main objects causing crash. This study was performed by interview with workers in construction field to evaluate the consciousness on safety and to analyze the type of use and the state. Finally the problems while using work plate were appeared with its requirements for the improved use. Based on the results from this study, amendments were proposed for some parts of regulation related, and further four types of development on the safe work plate were presented. It is expected that the safer construction environment could be composed by using the results.