• 대한임상전기생리학회지
• /
• 제2권3호
• /
• pp.13-24
• /
• 2004

The purpose of this study is to reveal the effect of electrical stimulation of body composition in obese person. Subjects were 30s to 40s aged healthy workers(2004. 3. 8~4. 17) in the S general Hospital in Suwon and they were brought to manage obesity. Subjects were divided into control group(Female<0.85, Male<0.90) and study group(Female>0.85, Male>0.90) by WHR(waist-hip ratio) that is measured by Automatic body composition analyzer(InBody 3.0). And we divided the study group with randomized methods into group A(n=8) and group B(n=8). Then we compared and analyzed the change of muscle mass, body fat, abdominal girth, WHR, BMI(body mass index) after application of electrical stimulation, three times a week, for 30 minutes in each session with 50 Hz of pulse frequency, $20\;{\mu}s$ or $250\;{\mu}s$ of pulse duration. There was statistically meaningful decrement of body fat(p<0.05) and abdominal girth(p<0.05) but not of body weight, muscle mass, WHR and BMI in the control group after application of electrical stimulation with 50 Hz, $20\;{\mu}s$. There were meaningful change of abdominal girth(p<0.05), WHR(p<0.05) and BMI(p<0.05), but not of body weight, muscle mass and body fat after application of electrical stimulation with 50 Hz, $20\;{\mu}s$ in group A. We applied electrical stimulation with 50 Hz, $250\;{\mu}s$ in group B, then there were meaningful change of body weight(p<0.05), body fat(p<0.01), abdominal girth(p<0.01), WHR(p<0.05) and BMI(p<0.01) but not of muscle mass only. Consequently, the pulse duration is the main parameter of electrical stimulation that affect the body composition of obese person in this study and if we combined the diet control to reduce blood components we could have better result. So it would be more effective to manage localized obesity(in abdomen, thigh, upper arm, etc.) if you apply electrical stimulation considering the pulse duration.

• 동아시아식생활학회지
• /
• 제15권6호
• /
• pp.675-686
• /
• 2005

It is known that appropriate exercise changes body composition and improves coronary artery disease. This study was undertaken to evaluate the relationships between aerobic exercise, body composition, and the blood lipid levels in the middle-aged women(33 to 54 years old). The 57 subjects were divided into two groups based on their exercise: the aerobic exercise group(A group: 44) which performed at about $60\%$ of $VO_2max$ during over 6 months and the sedentary one(S group: 13). The percentages of body fat waist/hip ratio(WHR), body mass, and lean body mass of two groups were measured and compared in serum HDLC level and oxidized LDL level, the two most effective factors of coronary artery disease. The subjects in A group showed the lower percentages of body fat and WHR, when compared with the ones in S group. The body mass and lean body mass of A group subjects were higher than those of S group subjects. The serum HDL-C level$(58.6\pm12.7mg/mL)$ was significantly higher for A than S group subjects.(p<0.05) The sem ox-LDL level $(6.64\pm4.11Eu/mL)$ for A group subjects was lower than S group ones. The fat mass showed significantly positive correlations with atherogenic index(AI)(r=0.301, p<0.05), and with blood glucose levels(r=0.334, p<0.05). Also the WHR whowed significantly positive correlations with LDL-C levels(r=0.277, p<0.05), and with AI(r=0.466, p<0.01). In summary, the subjects in A group have the lower percentages of body fat and WHR, when compared with the ones in S group. Also, A group subject showed a tendency that exercise enhances serum HDL-C levels and decreases oxidized LDL levels. And aerobic exercise showed positive results which change body composition and improve blood lipid levels. There were significantly positive correlations among the percentages of body fat At and blood glucose level. These results suggest that moderately intensive exercise is a significant factor in reducing coronary artery disease.

• Journal of the Korean Data and Information Science Society
• /
• 제24권2호
• /
• pp.303-310
• /
• 2013

체지방 감량에 대한 효과를 분석하고자 실험에 참가한 체지방율이 30% 이상인 42명의 여대생을 대상으로 일반폰을 사용하는 그룹과 스마트폰을 사용하는 그룹으로 나누어서 측정자료를 2주 간격으로 정리하여 8주간에 걸친 체지방 및 관련자료를 얻었다. 이 실험자료를 바탕으로 혼합모형을 이용하여 분석한 결과 AR(1)의 공분산행렬이 가장 적합한 모형으로 선택되었으며, 시점 간의 상관계수는 0.838로 상당히 밀접한 관련을 보여주었다. AR(1)의 공분산행렬을 설정하여 분석한 결과 처리간의 차이에서 스마트폰의 사용자가 일반폰의 사용자보다 0.654kg 정도의 체지방 감량 효과를 보여주었으며, 시간이 지날수록 체지방 감소효과가 있음을 알 수 있다. 그러나 처리와 시간과의 교호작용은 존재하지 않는다. 또한 실험실시 전의 체지방값과 총콜레스테롤은 유의하게 나타났으며, 섭취하는 칼로리는 약간 관련이 있으나, 허리엉덩이비율은 유의하지 않는 것으로 판명되었다.

• 한국분무공학회지
• /
• 제25권1호
• /
• pp.21-26
• /
• 2020

The objective of this work is to numerically reveal the effect of equivalence ratio change on the simultaneous reduction of NO_X and soot emissions from the simulated-EGR compression ignition engine containing CO₂. An experiment was conducted by using a single-cylinder common-rail injection system engine, an intake control system, and exhaust emissions analyzers. The numerical analysis results were validated under the same experimental conditions. To investigate the effect of equivalence ratio by simulated-EGR containing CO₂, the O₂, N₂, and CO₂ mole fraction were changed in the initial air conditions to the cylinder. The results were analyzed in terms of peak cylinder pressure, indicated mean effective pressure, indicated specific nitrogen oxide, and indicated specific soot. It was revealed that ignition delay characteristics and heat release rate (ROHR) characteristics were not significantly different according to the equivalence ratio. However, as the equivalence ratio increased from 0.68 to 0.83, the maximum combustion pressure and IMEP decreased by about 6.5% and 9.4%, respectively. In the case of ISFC, as is well known, the trend is opposite of IMEP. In the case of ISNO, as the equivalence ratio increased, less NO was generated, and as the equivalence ratio increased by 0.05, the ISSoot value of about 10% increased.

• 한국공작기계학회논문집
• /
• 제16권1호
• /
• pp.92-97
• /
• 2007

This study was carried out to minimize the lifting force and to design the slim sized frame of a height adjustment mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment as well as to achieve much slimmer frame for the pedestal. A tolerance analysis of 6 sigma was applied to achieve smooth lift at design stage not to change the tolerance specification of gap several times in a roller type of lifting mechanism at mass production stage. The specification of minimum gap and the target of production yield ratio were agreed with a quality team before tooling. A DFSS simulation on drawings had been done with reasonable tolerance and achievable standard deviation(${\sigma}$) several times until the target specification of gap and yield ratio was met. Once tolerance and deviation(${\sigma}$) were fixed tooling start was done successfully. A CAE method was applied to achieve a slim design. Design parameters were frozen when those parameters matched the reference strength data of standard model. Through those tolerance analysis and CAE simulation the number of tool modification was reduced and production yield ratio was raised up without arguing quality specification at production stage in the end.

• 대한기계학회논문집B
• /
• 제25권12호
• /
• pp.1692-1701
• /
• 2001

This study describes the combustion characteristics under various condition of air excess ratio and ignition timing in a 2-valve SI optically accessible engine with swirl control valve(SCV). It adapted three different types of SCV(open ratio 72.5%, 78%, 59%) to strengthen a swirl flow. Pressure data were acquired using pressure sensor to investigate the effect of swirl flow on combustion, and from these pressure data, IMEP(indicated mean effective pressure) and MFB(mass fraction burnt) were calculated to explain burn rate and flame speed. From acquired flame images, we inspected the flame propagation direction, flame area, and flame centroid. Flame propagation direction showed different tendency between with/without SCV, and flame area with SCV was faster and larger than that of conventional engine. Finally, the representative flame images at each crank angle were acquired by PDF method to verify flame growth process. It is found that strengthened swirl flow is more beneficial for faster and stable combustion.

• 한국CDE학회논문집
• /
• 제16권2호
• /
• pp.83-91
• /
• 2011

There are many researches to make low-energy building. Lots of them focus on facility systems and insulation performance of building materials. However, not only systematic solutions but also approaches in early design stages are important to reduce energy consumption. Using BIM(Building Information Modelling) is considered as an effective and efficient way to simulate building energy and decide alternatives than traditional energy simulation because BIM based energy simulation makes to reduce much time for energy modeling. This study focuses on development of optimized geometry for super tall office buildings in Seoul, Korea. Specifically, length to width ratio and building orientation are main topics of this study because these two topics are the most basic and preceding factors deciding mass design. In this study, Revit MEP 2011 and Ecotect Analysis 2011 are used to make case models and calculate energy load in early design stages. Energy properties of material abide by Korean Standards for Energy Conservation in Building, Korean Guideline for Energy Conservation in Public Office and ASHRAE Standard in USA. This study presents best length to width ratio of plan and optimized orientation by evaluating the case models. Furthermore, this study suggests what should be considered for each case to decrease energy load.

• 대한기계학회논문집B
• /
• 제26권2호
• /
• pp.238-244
• /
• 2002

A 5-valve(intake 3-valve) engine has been developed to increase engine performance. These engines have a high power caused by the decrease of inertia mass of an intake valve and the increase of intake effective area. In this study, in-cylinder flow patterns were visualized with laser sheet method and velocity profiles at near intake valves were inspected by using a two-color PIV. In addition, steady flow tests were performed to quantify tumble ratio of flow-fields generated by a tumble control valve(TCV). Experimental results of steady flow test show that the cure of tumble ratio in intake 3-valve engine farmed as a S shape with valve lift changes. This tendency is different from the one in intake 2-valve engine. Using laser sheet method and two color PIV method, we can find that the intake flow through upper valve increases and the velocity gradient also slightly increases as valve lift increases. From this study, the in-cylinder flow characteristics around intake valves were made clearly.

• Bulletin of the Korean Chemical Society
• /
• 제17권10호
• /
• pp.939-943
• /
• 1996

Reactions that proceed within mixed acetylene-methanol and ethylene-methanol cluster ions were studied using an electron-impact time-of-flight mass spectrometer. When acetylene and methanol seeded in helium are expanded and ionized by electron impact, the ion abundance ratio, [CH3OH+]/[CH2OH+] shows a propensity to increase as the acetylene/methanol mixing ratio increases, indicating that the initially ionized acetylene ion transfers its charge to adjacent methanol molecules within the clusters. Investigations on the relative cluster ion intensity distributions of [CH3OH2+]/[CH3OH+] and [(CH3OH)2H+]/[CH3OH·CH2OH+] under various experimental conditions suggest that hydrogen-atom abstraction reaction of acetylene molecule with CH3OH ion is responsible for the effective formation of CH2OH ion. In ethylene/methanol clusters, the intensity ratio of [CH3OH2]/[CH3OH] increases linearly as the relative concentration of methanol decreases. The prominent ion intensities of (CH3OH)mH over (CH3OH)m-1CH2OH ions (m=1, 2, and 3) at all mixing ratios are also interpreted as a consequence of hydrogen atom transfer reaction between C2H4 and CH3OH to produce the protonated methanol cluster ions.

• 한국환경복원기술학회지
• /
• 제10권4호
• /
• pp.83-94
• /
• 2007

Test application of revegetation measure was made on the roadside slope damaged by Gimcheon-Eomo national road improvement project in a bid to prevent the soil from being washed out as well as to restore the ecological environment, and the survey for assessing the effect of slope revegetation measures was conducted, beginning Sep 7 through Sep 20, 2006. In the wake of comprehensive reviewing and evaluating the surrounding topographic environment, physical and chemical characteristics of soil, germination of revegetation plants, analysis of bio mass, covering ratio and the plants appeared, revegetation measure C was found to have been most effective and desirable for further application in the area. Viewing the specific applicability by the area, revegetation measure C and C-1 appeared to be appropriate for blasting rock slope and ripping rock slope as they are efficient in preventing the slope from being washed out and in early revegetating. And revegetation measure B deemed to be effective to blasting rock slope or ripping rock slope as an alternative. And for cut slope, vegetation measure C-2 was judged to be more effective than measure D or E, while measure C-3 would be appropriateto embankment slope.