• 한방비만학회지
• /
• 제1권1호
• /
• 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.

• 동력기계공학회지
• /
• 제20권5호
• /
• pp.60-65
• /
• 2016

Dynamic performance of transmission has a substantial effect on dynamic performance and fuel efficiency of a vehicles. Dynamic performance of transmission and mass moments of inertia of transmission gears are related directly each other. Then a smaller amount of kinetic energy from vehicles that repeat acceleration and deceleration requires lighter rotating part in transmission. It is going to increases fuel efficiency as a result. In this study, equivalent inertia moments of inertia at different speeds were calculated by simplifying the transmission system. To find out lightening effect at low speed level gear on fuel efficiency, the powerflow of transmission was analyzed. And the lightning effect of the rotating parts in transmission is compared with the mass reduction of sprung parts in vehicle.

• Smart Structures and Systems
• /
• 제10권2호
• /
• pp.155-179
• /
• 2012

This paper aims at assessing the seismic performance of Tuned Mass Dampers (TMDs) based on sets of recorded ground motions. For the simplest configuration of a structure-TMD assembly, in a comprehensive study characteristic response quantities are derived and statistically evaluated. Optimal tuning of TMD parameters is discussed and evaluated. The response reduction by application of a TMD is quantified depending on the structural period, inherent damping of the stand-alone structure, and ratio of TMD mass to structural mass. The effect of detuning on the stroke of the TMD and on the structural response is assessed and quantified. It is verified that a TMD damping coefficient larger than the optimal one reduces the peak deflection of the TMD spring significantly, whereas the response reduction of the main structure remains almost unaffected. Analytical relations for quantifying the effect of a TMD are derived and subsequently evaluated. These relations allow the engineer in practice a fast and yet accurate assessment of the TMD performance.

• 한국환경과학회지
• /
• 제30권6호
• /
• pp.429-439
• /
• 2021

Food waste is both an industrial and residential source of pollution, and there has been a great need for food waste reduction. As a preliminary step in this study, waste reduction is quantitatively modeled. This study presents two models based on kinetics: a simple kinetic model and a mass transport-shrinking model. In the simple kinetic model, the smaller is the reaction rate constant ratio k₁, the lower the rate of conversion from the raw material to intermediate products. Accordingly, the total elapsed reaction time becomes shorter. In the mass transport-shrinking model, the smaller is the microbial decomposition resistance versus the liquid mass transfer resistance, the greater is the reduction rate of the radius of spherical waste particles. Results showed that the computed reduction of waste mass in the second model agreed reasonably with that obtained from a few experimantal trials of biodegradation, in which the microbial effect appeared to dominate. All calculations were performed using MATLAB 2020 on PC.

• The Journal of the Acoustical Society of Korea
• /
• 제26권2E호
• /
• pp.50-55
• /
• 2007

SBN (Structure-Borne Noise) reduction in resiliently mounted machineries are predicted by using mass-spring model and wave model. In mass-spring model, mount is modeled as a spring, while in wave model, mount is considered as an equivalent elastic rod for taking account into longitudinal wave propagation. The predictions for SBN reduction through mounts are compared to the measurements for four different pumps. It is found that the mass-spring model is valid only in low frequency range below few hundred Hz, while for high frequency ranges longitudinal wave propagation in the mount must be considered to explain the measurements. It is also shown that impedance of the floor slightly affects low frequency behaviour in mass-spring and wave model below 50 Hz - 80 Hz, so that in engineering practice the effect of floor impedance may be neglected in computing mount performance.

• Structural Engineering and Mechanics
• /
• 제43권5호
• /
• 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%.

• 대한조선학회논문집
• /
• 제44권5호
• /
• pp.488-495
• /
• 2007

In this paper, SBN (Structure-Borne Noise) reduction of resiliently mounted machinery and effect of the foundation impedance on mount performance is studied. SBN reduction through the mount is analyzed by using two theoretical models; mass-spring model and wave model, in which longitudinal wave propagation is included. It is found that floor impedance greatly affects SBN reduction through lower mount, while it is almost negligible to SBN reduction through upper mount. Comparisons between measurement and predictions shows that the mass-spring model is valid only in low frequency range below few hundred Hz, while for high frequency ranges longitudinal wave propagation in the mount must be considered.

• Structural Engineering and Mechanics
• /
• 제76권6호
• /
• pp.709-724
• /
• 2020

The typical inerter system, the tuned viscous mass damper (TVMD), has been proven to be efficient. It is characterized by an energy-dissipation-enhancement effect, whereby the dashpot deformation of TVMD can be amplified for enhanced energy dissipation efficiency. However, existing studies related to TVMD have mainly been performed on elastic structures, so the working mechanism remains unclear for nonlinear structures. To deal with this, an energy-spectrum analysis framework is developed systematically for classic bilinear hysteretic structures with TVMD. Considering the soil effect, typical bedrock records are propagated through the soil deposit, for which the designed input energy spectra are proposed by considering the TVMD parameters and structural nonlinear properties. Furthermore, the energy-dissipation-enhancement effect of TVMD is quantitatively evaluated for bilinear hysteretic structures. The results show that the established designed input energy spectra can be employed to evaluate the total energy-dissipation burden for a nonlinear TVMD structure. Particularly, the stiffness of TVMD is the dominant factor in adjusting the total input energy. Compared with the case of elastic structures, the energy-dissipation-enhancement effect of TVMD for nonlinear structures is weakened so that the expected energy-dissipation effect of TVMD is replaced by the accumulated energy dissipation of the primary structure.

• 한국한의학연구원논문집
• /
• 제17권2호
• /
• pp.173-181
• /
• 2011

Objective : The purpose of this study is to evaluate the effect of Yuebijiashu-tang with Low-Glycemic Diet on the obesity and to improve the oriental medical methods of treatment in obesity patients. Methods : Forty one patients were classified into four groups(Normal, Overweight, 1st Obesity, 2nd Obesity) by Body Mass Index(BMI). Weight, Body Fat Mass, Body Fat Rate, Waist Hip Rate, BMI and Obesity Index were compared in each group by t-test. Results : In distribution of sex, male was 7(17.1%), female was 34(82.9%). Mean age was 37${\pm}$11 and the patients in twenties were the most. Among four groups, the number of 1st obesity groups was the most. In the change of body composition, the reduction of weight was 6.82${\pm}$2.67kg, the reduction of body fat mass was 5.53${\pm}$2.30kg, the reduction of BMI was $2.51{\pm}0.85kg/m^2$, the reduction of body fat rate was 4.61${\pm}$2.17%, the reduction of waist hip rate was 0.019${\pm}$0.013. Conclusion : This study shows that Yu$\'{e}$biji$\~{a}$sh$\`{u}$-t$\~{a}$ng with low-glycemic diet is effective on weight reduction.

• Smart Structures and Systems
• /
• 제19권6호
• /
• pp.665-678
• /
• 2017

In this paper the tuned mass-damper-inerter (TMDI) is considered for passive vibration control and energy harvesting in harmonically excited structures. The TMDI couples the classical tuned mass-damper (TMD) with a grounded inerter: a two-terminal linear device resisting the relative acceleration of its terminals by a constant of proportionality termed inertance. In this manner, the TMD is endowed with additional inertia, beyond the one offered by the attached mass, without any substantial increase to the overall weight. Closed-form analytical expressions for optimal TMDI parameters, stiffness and damping, given attached mass and inertance are derived by application of Den Hartog's tuning approach to suppress the response amplitude of force and base-acceleration excited single-degree-of-freedom structures. It is analytically shown that the TMDI is more effective from a same mass/weight TMD to suppress vibrations close to the natural frequency of the uncontrolled structure, while it is more robust to detuning effects. Moreover, it is shown that the mass amplification effect of the inerter achieves significant weight reduction for a target/predefined level of vibration suppression in a performance-based oriented design approach compared to the classical TMD. Lastly, the potential of using the TMDI for energy harvesting is explored by substituting the dissipative damper with an electromagnetic motor and assuming that the inertance can vary through the use of a flywheel-based inerter device. It is analytically shown that by reducing the inertance, treated as a mass/inertia-related design parameter not considered in conventional TMD-based energy harvesters, the available power for electric generation increases for fixed attached mass/weight, electromechanical damping, and stiffness properties.