• Title/Summary/Keyword: Effect of mass reduction

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Effects of Saengsig with Behavior Modification Therapy on Body Composition Changes in Obese Patients (행동수정을 병행한 생식이 비만인의 신체조성에 미치는 영향)

  • 김경남;박성호;홍서영;윤호준;김융기;송윤경;임형호;이영종
    • The Journal of Korean Medicine
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    • v.24 no.1
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    • pp.9-28
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    • 2003
  • Objects : The aim of this study was evaluate the effect of the Saengsig taken along with Behavior Modification Therapy, Methods : We examined the body compositions of 20 obese patients who were treated with Saengsig and Behavior Modification Therapy for 2 months by Inbody 2.0. Results : Changes of body composition due to Saengsig with Behavior Modification Therapy were reduction of body weight by $3.14{\pm}1.33{\;}kg$, lean body mass by $0.14{\pm}1.48{\;}kg$, fat mass by $3.00{\pm}1.53kg$ and BMI by $1.30{\pm}0.54$ Conclusion : Fat mass and body fat rate were significantly reduced after treatment with Saengsig with Behavior Modification Therapy.

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Vibration suppression analysis of a long-span cable-stayed bridge based on earthquake-wind-traffic-bridge coupled system

  • Xinfeng Yin;Yong Liu;Wanli Yan;Yang Liu;Zhou Huang
    • Structural Engineering and Mechanics
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    • v.88 no.4
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    • pp.379-387
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    • 2023
  • Wind and earthquake loads may cause strong vibrations in large-span cable-stayed bridges, leading to the inability of the bridge to operate normally. An improved Pounding Tuned Mass Damper (PTMD) system was designed to improve the safety of the large-span cable-stayed bridge. The vibration control effect of the improved PTMD system on the large-span cablestayed bridge under the combined action of earthquake-wind-traffic was studied. Furthermore, the impact of different parameters on the vibration suppression performance of the improved PTMD system was analyzed. The numerical results indicate that the PTMD system is very effective in suppressing the displacements of the bridge caused by both the traffic-wind coupling and traffic-earthquake coupling. Moreover, the number, mass ratio, pounding stiffness, and gap values have a significant influence on the vibration suppression performance of the improved PTMD system. When the number of PTMD is increased from 3 to 9, the vibration reduction ratio of the vertical displacement is increased from 25.39% to 48.05%. As the mass ratio changes from 0.5% to 2%, the vibration reduction ratio increases significantly from 22.23% to 53.30%.

Probabilistic study on buildings with MTMD system in different seismic performance levels

  • Etedali, Sadegh
    • Structural Engineering and Mechanics
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    • v.81 no.4
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    • pp.429-441
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    • 2022
  • A probabilistic assessment of the seismic-excited buildings with a multiple-tuned-mass-damper (MTMD) system is carried out in the presence of uncertainties of the structural model, MTMD system, and the stochastic model of the seismic excitations. A free search optimization procedure of the individual mass, stiffness and, damping parameters of the MTMD system based on the snap-drift cuckoo search (SDCS) optimization algorithm is proposed for the optimal design of the MTMD system. Considering a 10-story structure in three cases equipped with single tuned mass damper (STMS), 5-TMD and 10-TMD, sensitivity analyses are carried out using Sobol' indices based on the Monte Carlo simulation (MCS) method. Considering different seismic performance levels, the reliability analyses are done using MCS and kriging-based MCS methods. The results show the maximum structural responses are more affected by changes in the PGA and the stiffness coefficients of the structural floors and TMDs. The results indicate the kriging-based MCS method can estimate the accurate amount of failure probability by spending less time than the MCS. The results also show the MTMD gives a significant reduction in the structural failure probability. The effect of the MTMD on the reduction of the failure probability is remarkable in the performance levels of life safety and collapse prevention. The maximum drift of floors may be reduced for the nominal structural system by increasing the TMDs, however, the complexity of the MTMD model and increasing its corresponding uncertainty sources can be caused a slight increase in the failure probability of the structure.

Experimental Study on the Static Balancing Method of an Unbalanced Rigid Rotor (불평형 회전체의 정적평형 방법에 대한 실험적 연구)

  • Chang, Ho-Gyeong;Kim, Sung-Kyu;Kim, Ye-Hyun
    • The Journal of the Acoustical Society of Korea
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    • v.10 no.2
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    • pp.13-22
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    • 1991
  • The presence of an unbalanced mass is originated the common source of vibration in machines with rotating rotor. In this study, the unbalanced rigid rotor mounted on an overhang shaft is balanced using the static balancing procedure, and the compensation mass is estimated by the phase angle method and four run method. Also, the reduction of vibration level before and after balancing is examined. In the experimental results, it is shown that the vibration due to the unbalanced mass is decreased by eliminating the effect of the unbalance. Above all, the four run method is proved more effective on the ability of vibration reduction, in small unbalanced mass, the phase angle method.

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Application of Mass Concrete Exposed to Marine Environment (염해환경에 노출된 매스콘크리트의 시공)

  • Kim Dong Seok;Park Sang Joon;Shin Hong Chol;Yoo Jae Kang
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.487-490
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    • 2005
  • This study was performed to investigate the effect of ternary blended cement concrete mixed with slag cement and fly ash on the compressive strength, the resistance to chloride ion penetration and reduction of hydration heat. Each performance of ternary blended cement concrete compared with binary blended cement concrete and ordinary portland cement concrete. As a result, it was concluded that ternary blended cement concrete is suitable to mass concrete under marine environment.

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Mass transfer in cross-flow dialyzer with internal recycle

  • Yeh, Ho-Ming;Chen, Chien-Yu
    • Membrane and Water Treatment
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    • v.4 no.4
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    • pp.251-263
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    • 2013
  • The internal reflux effect on dialysis through the retentate phase of a countercurrently cross-flow rectangular module is investigated. Theoretical analysis of mass transfer in cross-flow devices with or without recycling is analogous to heat transfer in cross-flow heat exchangers. In contrast to a device without reflux, considerable mass transfer is achievable if cross-flow dialyzers are operated with reflux, which provides an increase in fluid velocity, resulting in a reduction in mass-transfer resistance. It is concluded that reflux can enhance mass transfer, especially for large flow rate and feed-concentration operated under high reflux ratio.

The Effect of Obesity-Related Quality of Life on selecting a Goal for Weight Management in Overweight and Obese Patients (과체중 여성 환자들에서 비만 관련 삶의 질이 목표체중 설정에 미치는 영향)

  • Chun, Min Young
    • Korean Journal of Community Nutrition
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    • v.20 no.4
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    • pp.281-290
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    • 2015
  • Objectives: Obesity is known to influence physical and mental health as well as the general quality of life. The aim of this study was to evaluate the effect of obesity related quality of life on selecting a goal for weight management in overweight and obese female patients. Methods: A total of 140 overweight or obese (Body mass index $23kg/m^2$) female outpatients aged ${\geq}20$ and ${\leq}60$ years from one clinic participated in this study. Patients' desired weight (goal weight, ideal weight, satisfactory weight, acceptable weight and disappointed weight) and obesity related quality of life measures were evaluated. Univariate and multivariate analysis were performed to evaluate the effect of obesity related quality of life on goal weight reduction (%) and goal body mass index (BMI). Results: Mean BMI of overweight group, mild obesity group and severe obesity group were $62.0{\pm}4.8kg$, $68.5{\pm}5.5kg$ and $83.5{\pm}9.6kg$, respectively. Mean weight loss expectations of the three groups were $16.4{\pm}4.7%$, $19.5{\pm}5.3%$ and $30.2{\pm}6.8%$, respectively and goal weight was significantly different among the three groups. Severe obesity group had a lower total quality of life score including physical, work-related, daily living domains than overweight or mild obesity groups. In univariate and multivariate regression analysis, psychosocial domain of quality of life had an effect on goal weight reduction (%) and goal BMI. Conclusions: The results of this study demonstrated that the obese patients with poorer quality of life and psychosocial health tended to choose higher goal weight reduction and lower goal BMI.

Effect and Reduction Method of Rotating Unbalance Mass on Vibration Characteristics of Front Axle (회전 불균형 질량이 Front Axle 진동특성에 미치는 영향 및 저감 방안)

  • Park, Tae-Wone;Kim, Kee-Joo;Choi, Byung-Ik;Sung, Chang-Won;Kim, Sang-Shik;Kim, Heon-Young
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.6
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    • pp.165-169
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    • 2007
  • The purpose of this study is to investigate the effect of rotating unbalance mass on vibration characteristics of the front axle. The power-train systemof the vehicle is composed of several rotating parts. These component parts should be properly balanced by the balancing machine, however,sometimes these have the unbalance mass which causes the critical vibration in the vehicle. Therefore, this study suggests the vibration improvement method based on reducing the unbalance mass through changing the assembly type between the companion flange and the constant velocity joints. In addition, the way to increase the inertia moment of the companion flange was proposed.

Displacement Response Properties of Spatial Structures and High-Rise Buildings According to the Change of TMD Mass (TMD 설치 질량 변화에 따른 대공간 구조물과 고층건물의 변위 응답 특성)

  • Lee, Young-Rak;Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.3
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    • pp.107-116
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    • 2020
  • In this paper, the displacement response to seismic loads was analyzed after installing TMD in spatial structures and high-rise buildings. In the case of a spatial structures, since it exhibits complex dynamic behavior under the influence of various vibration modes, it is not possible to effectively control the seismic response by installing only one TMD, unlike ordinary structures. Therefore, after installing eight TMDs in the structure, the correlation between displacement response and mass ratio was examined while changing the mass. The TMD must be designed to have the same frequency as the structure frequency so that the maximum response reduction effect can be exhibited. It can be confirmed that the most important variable is to select the optimal TMD mass in order to install the TMD on the structure and secure excellent control performance against the earthquake load. As a result of analyzing the TMD mass ratio, in the case of high-rise buildings, a mass ratio of 0.4% to 0.6% is preferable. In spatial structures, it is desirable to select a mass ratio of 0.1% to 0.2%. Because this study is based on the theoretical study based on numerical analysis, in order to design a TMD for a real structure, it is necessary to select within a range that does not affect the safety of the structure.

A Study on the Flow Characteristics over the Rotating Susceptor in CVD Reactor (CVD 반응로 내부 회전 원판 주위의 유동 특성 연구)

  • Cha, Kwan;Kim, Youn-J.;Boo, J.H.
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.213-218
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    • 2001
  • The characteristics of the fluid flow and mass transfer in a vertical atmospheric pressure chemical vapor deposition (APCVD) are numerically studied. In order to get the optimal process parameters for the uniformity of deposition on a substrate, Navier-Stokes and energy equations have been solved for the pressure, mass-flow rate and temperature distribution in a CVD reactor. Results show that the thermal boundary condition at the reactor wall has an important effect in the formation of buoyancy-driven secondary cell when radiation effect is considered. Results also show that reduction of the buoyancy effect on the heated reactor improves the uniformity of deposition.

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