• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.34-35
• /
• 2014

we designed a distributed mass dynamic vibration absorber for vibration reduction in a dual mode system. And we were subjected to evaluation of the vibration reduction performance of the distributed mass dynamic vibration absorber through experiments.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.638-641
• /
• 1995

The model-technology has been conduced to a large quantity of automobile and electric products. However, many problems in mold-technology have been solved through trial and error of experts. So it has given rise to overdesign of mold and generated other problems in production line. In this paper we choosed the lower-mold of a cool chamber in refrigerator as the model of the study and mass reduced overdesigned mold. In mass reduction process, several cases in plane processing error were selected for the sample case through FEM analysis & simplicated theory analysis and each case was evaluated for mass reduction.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.169-170
• /
• 2018

In this study, TGA analysis of hardened cement paste with fire damage was performed. The mass reduction rate of 600 ℃ specimens was about 22 ~ 25%, and the sample of 800 ℃ showed the mass loss rate of 9 ~ 13%. As the target temperature and hold time increased, the mass reduction rate decreased. As the depth increased, the mass reduction rate decreased.

• Journal of Korean Medicine for Obesity Research
• /
• v.1 no.1
• /
• pp.21-32
• /
• 2001

Objectives: The aim of this study was to the effect of very low calorie diet with Chegameuiintang to treat obese patients . Methods: We have evaluated 54 obese patients during very low calorie diet with Chegameuiintang weight-reducing regime by determining the body composition before and 1 month, 2 months after treatment by Bioelectrical impedence analysis . Results: In the change of body composition by the treatment, mean weight reduction was 11.59kg(15.57% of initial weight), mean weight reduction after 1month was 7.68kg( 10.31% of initial weight), mean weight reduction after 2 months was 3.91 kg(5.86% of weight after 1 month). Mean reduction in total fat mass was 8.03kg(2914% of the initial fat mass) which constitutes 69.28%. Mean reduction in lean body mass was 3.56kg(7.59%) Conclusions: This study has demonstrated that the compound therapy of very low calorie diet and Chegameuiintang (Tiganyiyiren-tang) is the good way of weight reduction, which reduces total fat mass and preserves lean body mass.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.1331-1332
• /
• 2006

The present investigation has attemped to optimize hydrogen reduction process for the mass production of Fe-8wt%Ni nanoalloy powder from ball milled $Fe_2O_3-NiO$ powder. In-situ hygrometry study was performed to monitor the reduction behavior in real time through measurement of water vapor outflowing rate. It was found that the reduction process can be optimized by taking into account the apparent influence of water vapor trap in the reactor on reduction kinetics which strongly depends on gas flow rate, reactor volume and reduction.

• Journal of the Korean Society of Combustion
• /
• v.4 no.2
• /
• pp.11-22
• /
• 1999

Combustion characteristics of the wood chips(balsa chips) were experimentally investigated with respect to the thermal recycle system of the urban waste. The urban waste contains plastics, vegetable and wood materials. Wood was chosen as an example of the one of the component of urban dust. A small wood chip was burned in a electric furnace by the micro-electric balance. The mass reduction rate was normalized by the initial mass of test piece and the time of volatile combustion end. When the mass of the wood chips(balsa chips) was larger than 0.5g, the combustion similarity was found on the normalized mass reduction rate.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.759-763
• /
• 2004

High frequency noise of fuel pump has does claimed by user. But high frequency of fuel pump can't heat in the car. But this noise Is an offensive noise outside car. In this study is noise reduction used to mass law. Especially high frequency (for example BPF(blade pass frequency)) is influenced of this law. In detail used to transmission and add to mass according to mass law, reduced particular noise. As a result high frequency is down until can't perception.

• Structural Engineering and Mechanics
• /
• v.43 no.5
• /
• pp.607-621
• /
• 2012

The Expo Culture Centre is one of the permanent buildings at the World Expo 2010 in Shanghai, China. The main structure has an oval shape and consists of 36 radial cantilever steel trusses with different lengths and inner frames made of concrete-filled rectangular steel tube members. Tuned mass dampers are used to reduce the excessive vibrations of the sixth floor that are caused by human-induced resonance. A three-dimensional analytical model of the system is developed, and its main characteristics are established. A series of field tests are performed on the structure, and the test results show that the vertical vibration frequencies of most structural cantilevers are between 2.5 Hz and 3.5 Hz, which falls in the range of human-induced vibration. Twelve pairs of tuned mass dampers weighing 115 tons total were installed in the structure to suppress the vibration response of the system. These mass dampers were tuned to the vertical vibration frequency of the structure, which had the highest possibility of excitation. Test data obtained after the installation of the tuned mass dampers are used to evaluate their effectiveness for the reduction of the vibration acceleration. An analytical model of the structure is calibrated according to the measured dynamic characteristics. An analysis of the modified model is performed and the results show that when people walk normally, the structural vibration was low and the tuned mass dampers have no effect, but when people run at the structural vibration frequency, the tuned mass dampers can reduce the floor vibration acceleration by approximately 15%.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.3
• /
• pp.319-323
• /
• 2012

Transmission is one of the important pars to transmit power from engine to wheels. Mass reduction gears can make the engine power requirement reduce, and can make dynamic performance and fuel efficiency of vehicle improve. Transmission gears are modified for mass reduction without changing their tooth shapes, face widths, and modules by using shape optimization and re-check process. Also structural stability is verified by FEA.

• Smart Structures and Systems
• /
• v.18 no.1
• /
• pp.93-115
• /
• 2016

A particle tuned mass damper (PTMD) system is the combination of a traditional tuned mass damper (TMD) and a particle damper (PD). This paper presents the results of an experimental and analytical study of the damping performance of a PTMD attached to the top of a benchmark model under wind load excitation. The length ratio of the test model is 1:200. The vibration reduction laws of the system were explored by changing some system parameters (including the particle material, total auxiliary mass ratio, the mass ratio between container and particles, the suspending length, and wind velocity). An appropriate analytical solution based on the concept of an equivalent single-unit impact damper is presented. Comparison between the experimental and analytical results shows that, with the proper use of the equivalent method, reasonably accurate estimates of the dynamic response of a primary system under wind load excitation can be obtained. The experimental and simulation results show the robustness of the new damper and indicate that the damping performance can be improved by controlling the particle density, increasing the amount of particles, and aggravating the impact of particles etc.