• 디지털융복합연구
• /
• 제18권12호
• /
• pp.195-204
• /
• 2020

본 연구에서 목적은 수출중량과 관제량, 내항화물입항, 수출화물수송, 선박출항과의 관계를 분석하는데 있다. 통계청 국가통계포털에서 지난 2011년 1월부터 2020년 5월까지 총 113개 월간자료를 검색하여 사용하였다. 본 연구에서는 전년 동월대비 변동률을 이용하여 수치분석과 지표분석, 모형분석을 수행하였다. 상승률 동향에서 관제량은 2020년도 초부터 코로나19의 영향으로 150%에서 60%대로 급락하였고 동시에 수출중량과 수출화물수송도 동반 하락하는 모습을 보여주었다. 분석결과 수출중량은 수출화물수송 및 관제량과 상대적으로 동조화현상이 높게 나타난 반면 수출중량과 내항화물은 상대적으로 낮게 나타났다. 수출중량이 지난 2019년 이후 변동률이 감소하면서 2020년 이후 더 이어질 것으로 예상된다. 향후 관제량이나 수출화물수송의 반등시점을 찾을 수 있다면 수출중량의 상승시점을 예상해 볼 수 있을 것이다. 가능한 빠른 시간 내에 수출중량의 증가세가 나타나기를 기대해 본다.

• 대한조선학회논문집
• /
• 제47권1호
• /
• pp.30-37
• /
• 2010

In order to control the weight balance of the waterjet propulsion ship, the pump's weight needed to be decreased. We reduced length of pump hub, overall length of pump and chord length of impeller and stator. To keep pump efficiency and cavitation performance similar to the $1^{st}$design pump, optimum design and experiment were conducted. This paper describes experimental method and numerical analysis for pump design. At the blade design stage, performance analysis of the pump is conducted using commercial CFD codes ($BladeGen^+$,CFX-10). Required performance and cavitation characteristics of the design pumps were measured and observed using the stand-alone test apparatus. The weight of the pump was successfully decreased through a series of pump design processes composed of blade design, performance analysis and model test.

• Tribology and Lubricants
• /
• 제39권3호
• /
• pp.94-101
• /
• 2023

Automotive wheel bearings are a critical component of vehicles that support their weight and facilitate rotation. Life and stiffness are significant performance characteristics of wheel bearings. Designing wheel bearings involves finding optimal design variables that satisfy both performances. CO₂ emission reduction and fuel efficiency regulations attribute to the recent increase in design requirements for lightweight and compact automotive parts while maintaining performance. However, achieving a design that maintains performance while reducing weight poses challenges, as performance and weight are generally inversely proportional. In this study, we perform design optimization of automotive wheel bearings considering life and stiffness. We develop a program that calculates the basic rated life and modified rated life based on international standards for evaluating the life of wheel bearings. We develop a regression equation using regression analysis to address the time-consuming stiffness analysis during repetitive analysis. We perform ANOVA and main effect analyses to understand the statistical characteristics of the developed regression equation. Furthermore, we verify its reliability by comparing the predicted and test results. We perform design optimization using the developed life prediction program, stiffness regression equation and weight regression equation. We select bearing specifications and geometry as design variables, weight as the cost function, and life and stiffness as constraints. Through design optimization, we investigate the influence of design variables on the cost function and constraints by comparing the initial and optimal design values.

• 한방비만학회지
• /
• 제19권1호
• /
• pp.31-41
• /
• 2019

Objectives: The purpose of this study was to investigate the effects of gender, age, body weight, muscle mass, fat mass, body mass index (BMI), metabolism, and compliance with medication on weight loss in obese adults. Methods: We reviewed the medical records of 178 patients who were visited to the Korean Oriental Clinic for 3~6 month and had obesity treatment using Gamitaeumjowee-tang from April 2017 to May 2017. We conducted a paired T-test, correlation coefficient and decision tree to analyze factors influencing obesity treatment. Results: The results of correlation analysis showed that initial weight (kg), initial fat mass (kg), BMI ($kg/m^2$), compliance with medication (%), Original Harris-Benedict Equation, Revised Harris-Benedict Equation and The Mifflin St Jeor Equation was significantly correlated to weight loss (kg) (P<0.001). As a result of constructing the decision tree model, it showed that over 5% weight loss of their initial weight (n=154) was related with initial BMI ($kg/m^2$), compliance with medication (%) and initial muscle mass (kg). In case of over 5 kg weight loss of their initial weight (n=131), it was related with initial BMI ($kg/m^2$), compliance with medication (%) and final BMI ($kg/m^2$). Conclusions: This study suggests that weight loss may be affected by initial factors and that initial factors can be used for obesity treatment.

• Environmental Analysis Health and Toxicology
• /
• 제3권1_2호
• /
• pp.43-54
• /
• 1988

Experiment was performed to investigate the immunotoxicity of cadmium administered orally and the effect of ginseng petroleum ether fraction on it. Mice were given 3, 30, or 300 ppm cadmium as cadmium chloride orally in the drinking water and injection of ginseng petroleum ether fraction intraperitoneally for 4 weeks. Mice were sensitized and challenged with sheep red blood cells (S-RBC). Humoral immune response was evaluated by antibody production and Arthus reaction. Body weight gain, spleen weight, thymus weight, and liver weight were also measured. In the present study, cadmium generally suppressed the humoral immunity. There was decrease in the rate of body weight gain and liver weight to body weight by cadmium-administration. Ginseng petroleum ether fraction showed restoring effect, to some extent, on the decrease in PFC and in the rate of liver weight to body weight by cadmium-administration. But it more suppressed Arthus reaction.

• Nutrition Research and Practice
• /
• 제6권2호
• /
• pp.132-137
• /
• 2012

The objective of this study was to examine the influence of anthropometric measurements of pregnant women, gestational weight gain, fundal height, and maternal factors, namely age, education, family income, parity along with maternal hemoglobin, on birth weight of neonates. A cross sectional study was performed in Khoy City in north west of Iran. Four hundred and fifty healthy pregnant women in the age between 16-40 years were selected for this study from seven health urban centers and one referral hospital. Findings showed that the mean age, height, fundal height, maternal weight, and gestational weight gain during pregnancy were 26.1 years, 159.1 cm, 32.9 cm, 72.0 kg, 11.8 kg respectively. The mean birth weight of neonates was 3.2 kg and 11% of neonates showed low birth weight. Age, family income, maternal height, weight, gestational weight gain and fundal height were significantly associated with birth weight of neonates. Using binary logistic regression analysis, fundal height, maternal hemoglobin, family income and gestational weight gain of pregnant women could be considered as predictive factors of birth weight of neonates.

• 한국수자원학회논문집
• /
• 제41권1호
• /
• pp.1-15
• /
• 2008

본 연구의 목적은 금강수계의 가장 효율적인 가중치를 찾을 수 있는 절차를 제시하는 것이다. 일반적으로 다목적 최적화 모형의 결과는 목적함수에 부여된 가중치에 크게 좌우되는 경향이 있다. 특히 다목적 저수지 운영 문제의 경우는 어떤 유입량 시나리오가 적용되느냐에 따라 그에 적합한 가중치가 크게 달라질 수 있다. 따라서 유입량의 변동성을 감안해서 저수지 운영자에게 적합한 초기 가중치를 적용하는 것은 매우 큰 의미가 있다. 이에 본 연구는 유입량의 불확실성을 감안하여 적절한 가중치군을 도출할 수 있는 절차를 제안한다. 제안한 절차에서는 다중목적 최적화모형(GA-CoMOM)을 통해 파레토 집합에 대응되는 가중치군을 도출하고, DEA-윈도우분석(DEA-window analysis)과 교차효율성 분석(cross-efficiency analysis)을 사용하여 후보 가중치에 대한 순위를 산정하고, 이 결과를 분석해서 적합한 가중치를 선정한다. 이 절차를 금강 수계 저수지군 연계 운영 문제에 적용한 결과 유입량의 불확실성을 감안해서 가중치를 설정할 수 있었다.

• 생명과학회지
• /
• 제7권1호
• /
• pp.59-65
• /
• 1997

In this experiment, gene actions were analysized for seven barley parents in order to obtain basic information on their genetic improvement by diallel crosses. The results obtained were summarized as follows. In analysis of variance, additive, dominant, maternal and reciprocal effects were observed significantly for culm length, tiller number, number of spiked per plant, culm diameter, awn length, leaf width, number of grains per spike, and 1000 grain weight. Over-dominance was shown by Vr-Wr graphic analysis in five characters such as tiller number, number of spikes per plant, length of flag leaf, number of grains per spike, and 1000 grain weight, and partial dominance in four characters such as culm length, culm diameter, awn length, and leaf width. Component of genetic varience analyzed for four characters such as culm diameter, awn length, length of flag leaf, and leaf width showed that additive effects were higher than dominant effects. Culm length, tiller number, number of spikes per plant, number of grains per spike, and 1000 grain weight showed dominant effects higher than additive effects. The narrow-sense heritability for awn length, leaf width, and number of grains per spike showed high values as more than 0.62, while broad-sense heritability for culm length, number of spikes per plant, culm diameter, awn length, leaf width, number of grains per spike, and 1000 grain weight showed high values as more than 0.65.

• Child Health Nursing Research
• /
• 제23권2호
• /
• pp.249-257
• /
• 2017

Purpose: The aim of this study was to assess the body weight perception of adolescents and to investigate the difference between mental health and weight control behavior according to body weight perception. Methods: Study data on 12-18 years old adolescents with normal BMI was obtained from the 6th Korea National Health and Nutrition Examination Survey (2013-2015). Rao-Scott Chi-square test and ANOVA were used for the analysis. Results: The percentage of adolescents with a misperception of body weight was 43.3%, and their subjective health status (p=.013), stress perception (p=.001), and depression (p=.001) were worse than for adolescents who had the correct perception of their body weight. The percentage of adolescents who were trying to lose weight while perceiving their body weight as normal was 36.9%. Body weight control behavior had significant differences according to dietary intake (frequency of eating dinner (p=.015)), energy intake (p=.004), and carbohydrate intake (p<.001), but there was no significant difference according to exercise. Conclusion: Parents, school teachers, and nurses should make efforts to ensure that Korean adolescents perceive their body weight correctly, and prevent unhealthy weight control behaviors.

• International Journal of Aeronautical and Space Sciences
• /
• 제15권4호
• /
• pp.383-395
• /
• 2014

According to the requirement of wing weight estimation and frequent adjustments during aircraft conceptual design, a wing weight estimation method considering the constraints of structural strength and stiffness is proposed to help designers make wing weight estimations rapidly and accurately. This method implements weight predictions on the basis of structure weight optimization with stiffness constraints and strength constraints, which include achievement of wing shape parametric modeling, rapid structure layout, finite element (FE) model automated generation, load calculation, structure analysis, weight optimization, and weight computed based on modeling. A software tool is developed with this wing weight estimation method. This software can realize the whole process of wing weight estimation with the method and the workload of wing weight estimation is reduced because much of the work can be completed by the software. Finally, an example is given to illustrate that this weight estimation method is effective.