• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.16-22
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• 2019

This study proposed estimation methods for weight and center of gravity of small fishing vessels. Weights loaded on small fishing vessels were divided into fixed weights such as crew, fishing gear, and variable weights such as fuel, fresh water, provision, bait, and fish. Based on statistical analyses with weight data of several small fishing vessels, weight, longitudinal center of gravity (LCG), vertical center of gravity (KG) of each item were represented as linear functions of vessel gross tonnage. In addition, weighting factors of variable weights were added on estimation formulas in accordance with vessel loading conditions, e.g. full load departure condition. Estimation methods were verified using actual small fishing vessel data.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.111-119
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• 2023

Internal storage state, weight data, and weight-centered calculation values for overhead bin can all be seen in this paper's real-time internal status identification system. The suggested system offers such valuable data via a range of sensors, including load cells and switch arrays. The proposed system could locate internal free space, locate the center of gravity, and give real-time visual information. It was developed utilizing an embedded system and the C programming language. These features led to the creation of smart overhead bins and real-time cargo loading monitoring technologies, both of which could one day aid in the creation of a cargo loading automation system.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.1
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• pp.83-89
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• 2009

Generally, automobile cooling fan is used to lower the temperature of radiator. The cooling fans are manufactured by plastic injection molding process. The center of gravity of cooling fan is often deviated from the center due to the use of deteriorated materials. As the unbalanced of the cooing fan can generate noise, it is required to measure the degree of deviation of center of gravity in the cooling fan. In this work, automatic fan balancer which can effectively detect the magnitude and position of the unbalanced cooling fan is proposed and several experiments are carried out to verify the feasibility of the proposed algorithm.

• Structural Engineering and Mechanics
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• v.38 no.6
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• pp.825-847
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• 2011

This paper investigates the design using wind-moment method for semi-rigid un-braced steel frames bending on weak axis. A limiting sway method has been proposed to reduce the frame sway. Allowance for steel section optimization between moment of inertia on minor axis column and major axis beam was used in conjunction with slope-deflection analysis to derive equations for optimum design in the proposed method. A series of un-braced steel frames comprised of two, four, and six bays ranging in height of two and four storey were studied on minor axis framing. The frames were designed for minimum gravity load in conjunction with maximum wind load and vice-versa. The accuracy of the design equation was found to be in good agreement with linear elastic computer analysis up to second order analysis. The study concluded that the adoption of wind-moment method and the proposed limiting sway method for semi-rigid steel frame bending on weak axis should be restricted to low-rise frames not more than four storey.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.47-53
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• 2021

Gait kinematics and kinetics have a similar tendency between men and women, yet it remains unclear how walking while carrying a load affects the gait mechanism. Twenty adults walked with preferred velocity on level ground of 20 m relative to change of a load carriage (no load, 15%, 30% of the body weights) aimed to observe gait mechanism. We measured gait posture using the three-dimensional image analysis and ground reaction force system during stance phase on left foot. In main effect of gender difference, men showed increased displacement of center of gravity (COG) compared to women, and it showed more extended joint angle of hip and knee in sagittal plane. In main effect of a load difference, knee joint showed more flexed postuel relative to increase of load carriage. In main effect of load difference on the kinetic variables, medial-lateral force, anterior-posterior force (1st breaking, 2nd propulsive), vertical force, center of pressure (COP) area, leg stiffness, and whole body stiffness showed more increased values relative to increase of load carriage. Also, men showed more increased COP area compared to women. Interaction showed in the 1st anterior-posterior force, and as a result of one-way variance analysis, it was found that a load main effect had a greater influence on the increase in the magnitude of the braking force than the gender. The data in this study explains that women require little kinematic alteration compared to men, while men in more stiff posture accommodate an added load compared to women during gait. Additionally, it suggests that dynamic stability is maintained by adopting different gait strategies relative to gender and load difference.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.5
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• pp.287-296
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• 2020

The present study aims to improve the accuracy of the maneuvering simulations based on captive model test results. To derive the hydrodynamic coefficients in a self-propelled condition, a mathematical maneuvering model using a whole vehicle model was established. Captive model tests were carried out using the Vertical Planar Motion Mechanism (VPMM) equipment. A motor controller was used to control the constant propeller revolution rate during pure motion tests. The resistance tests, self-propulsion tests, static drift tests, and VPMM tests were performed in the towing tank of Seoul National University. When the vertical drift angle changes, the gravity load on the sensors were changed. The hydrodynamic forces were deduced by subtracting the gravity load from the measured forces. The hydrodynamic coefficients were calculated using the least-square method. The simulation of the turning circle test was compared with the free-running model test result, and the error of the turning radius was 8.3 % compared to the free-running model test.

• Journal of the Korean Society of Safety
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• v.16 no.4
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• pp.147-152
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• 2001

The tower cranes are the very useful construction machine in the high place works. But they are very susceptible to the load balance, the wind load and the hanging load because they are the very slender structures and those center of gravity is located in the upper part. Therefore, the collapse accidents of tower one have repeatedly happened during the assemble or disassemble works. The correcting frame may has often used in order to correct the error in the setting of foundation anchors. The goal of this study is that propose the methods preventible the collapse accident of tower crane which is constructed by using the correcting frame. In order to accomplish the goal of this study, the field survey, the reference investigation and the structure analysis were performed for the collapse accident of tower crane using the correcting frame. This study result in the methods preventible the same accident.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.109-116
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• 2017

Objective: This study aimed to investigate the relationship between leg stiffness and kinematic variables according to load while running. Method: Participants included eight healthy men (mean age, $22.75{\pm}1.16years$; mean height: $1.73{\pm}0.01m$; mean body weight, $71.37{\pm}5.50kg$) who ran with no load or a backpack loaded with 14.08% or 28.17% of their body weight. The analyzed variables included leg stiffness, ground contact time, center of gravity (COG) displacement and Y-axis velocity, lower-extremity joint angle (hip, knee, ankle), peak vertical force (PVF), and change in stance phase leg length. Results: Dimensionless leg stiffness increased significantly with increasing load during running, which was the result of increased PVF and contact time due to decreased leg lengths and COG displacement and velocity. Leg length and leg stiffness showed a negative correlation (r = -.902, $R^2=0.814$). COG velocity showed a similar correlation with COG displacement (r = .408, $R^2=.166$) and contact time (r = -.455, $R^2=.207$). Conclusion: Dimensionless leg stiffness increased during running with a load. In this investigation, leg stiffness due to load increased was most closely related to the PVF, knee joint angle, and change in stance phase leg length. However, leg stiffness was unaffected by change in contact time, COG velocity, and COG displacement.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.7
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• pp.104-118
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• 1998

In this paper, the motion of ballscrew and shape of workpiece are the main objective variables varying with load conditions. To verify feed mechanism in NC lathe, the monitoring system is designed and cutting condition variables are spindle speed depth of cut and feed. During machining, rotation number of ballscrew motion of ballscrew in direction to gravity center and cutting force are measured. After machining, the roughness of workpiece is measured.

• 한국기계연구소 소보
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• s.10
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• pp.63-77
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• 1983

This paper presents the hydrodynamic performance characteristics of a planing boat which was tested with a new dynamometer system specifically designed to measure towing force along the thrust plane, the change in trim angle and the vertical displacement of the model center of gravity from still water condition. The test conditions include systematic variations in the three positions of LCG and the three load coefficients of a high speed planing boat.