• Korean Journal of Human Ecology
• /
• v.24 no.5
• /
• pp.687-700
• /
• 2015

Lines of non-extension (LoNEs) on torso surface during arm abduction were investigated to provide appropriate location for inserting less-extensible yarns which can be used as seams for design and or clothing pressure variation. As experimental methods, reference points about 3 cm apart were marked on the skin and scanned at 30, $90^{\circ}$ and $135^{\circ}$ arm abduction. Skin deformation was measured by connecting reference points in horizontal, vertical and various angles of diagonal directions. Observation of skin deformation was made within the separated sections of the torso as well as integrated ones to cover the various occasions of design application. LoNEs of front and back torso were provided as mapping lines. Actual compression wear of three types was constructed with different pattern reduction rate at each separated section using LoNEs as boundary cutting lines. Clothing pressure and subjective evaluations of those three compression wear were evaluated by six subjects. LoNEs found in this study were useful as seam lines to differentiate clothing pressure at each part of the body, providing positive wear sensation. It is also expected that LoNEs can be paths for less strechable conductive yarns of IT-integrated upper garments.

• Journal of Biomedical Engineering Research
• /
• v.32 no.3
• /
• pp.230-236
• /
• 2011

The aim of this study was to investigate the alteration of lumbar spine and trunk postures on different load-carrying types and amounts under static loading. Two load-carrying types(unilateral carrying: UC vs. bilateral carrying: BC) and four different loads(0, 5, 10, and 15 kg) were randomly tested in this study. Carrying a heavy bag would affect human body posture, specifically lumbar spine curvature, which is considered as one of sources of back problems. Previous studies have not paid attention to the approach of the multisegment model of the lumbar spine and trunk. This study separated two compartments of trunk segment(the lumbar and thorax) in the analysis. The multisegment model of the lumbar spine in addition to Helen-Hayes marker set was used. Eight motion analysis cameras and a force plate were utilized. Ten male subjects(mean mass, $70.6{\pm}3.97$ kg; mean height, $178{\pm}4.18$ m) having no musculoskeletal disease participated in this study. We analyzed trunk angles in three anatomical planes and the spinal curvature in sagittal and frontal planes. Increased loading in both UC and BC significantly resulted in increases in trunk forward lean but only UC induced increases in trunk lateral lean. In addition, increased loading in BC produced flatten lumbar curvature in sagittal plane. As far as coupling motion, subjects tended to use axial rotation of the lumbar spine in transverse plane in response to increased UC loading. Finally, it is concluded that the increased static loading in UC rather than in BC tends to causes combined alterations of the spinal postures(sagittal and transverse planes together), which would be vulnerable to improper mechanical stresses on the spine.

• Korean Institute of Interior Design Journal
• /
• v.15 no.4 s.57
• /
• pp.89-96
• /
• 2006

Magnetic Resonance Imaging (MRI) scanner is the device to draw an image of conditions and the spread of various tissue in the body. It is used by making the patient into rounded superconductor and using high frequency which cause resonances. It uses superconduction magnet and high frequency that is non-ionizing radiation so can acquire biochemical, physical, and functional information of tissue. It is also very useful because it can scan tomography from many different angles to diagnose disease of a nervous system, the heart, and a skeletal structure. It also has advantages of that there is no risk of radiation exposure and the ability of observation on organizations such as brains, livers and the spinal cord of people. Since these features, the rate of use has been increased accordingly more considerations of the security are required when it plans. The weight of devices and the cover problem of the strong magnetic field which is occurred by magnetic resonance at the time of diagnosis can cause very important structure problems and architectural condition. That also the recent tendency which needs stronger equipment means that planning of the MRI unit should generally aim at purposing of the proximity for the device maintenance and up-grade and of further expansion. However there are not enough studies and data on the magnet resonance imaging in domestic hospitals. According to these reasons, this study has an object of indicating basic data on MRI unit plan standard and alternative proposals.

• Journal of the Korea Society for Simulation
• /
• v.20 no.1
• /
• pp.51-59
• /
• 2011

This paper is concerned with locomotion of dog-like quadruped robots that can adapt to various terrains, mainly dealing with implementation methods and characteristics of static and dynamic gaits. To this end, a 12-DOF robot is built in house, motional trajectories of its body and feet are generated mimicking biological life, and the corresponding leg joint angles are analytically obtained by inverse kinematics. Such joint angle data are then applied to the robot's ADAMS model for computer simulations so that the planned walk and trot gaits are both confirmed dynamically stable. However, contrary to the simulation results, previous trot patterns showed unstable behavior during experiments. This problem led us to analyze the reason, and in the course we discovered the importance of maximally utilizing the concept of WSM rather than ZMP and therefore reducing the gait period to secure the stability of dynamic gaits such as trot.

• Journal of the Ergonomics Society of Korea
• /
• v.32 no.4
• /
• pp.389-396
• /
• 2013

Objective: The ride qualities of the six passenger cars were evaluated in 4 subjects on the highway and uneven road. The relation between vibration with driving velocity and driving posture were also investigated separately. Background: Ride comfort plays an important role in the vehicle design. Vibration is the one of the principal components associated with ride comfort. Method: The acceleration of the foot, hip and back were measured using B&K accelerometers in this study. The velocity of the passenger cars was maintained at a constant speed of 80km/h on the highway and 40km/h on the uneven road. For evaluating the effects of driving velocity and driving posture on vehicle's vibration level, separate experiments were performed on the highway with 5 different vehicle speeds and 5 different backrest angles, respectively. Results: The overall ride value of the luxury car showed the best result while the smaller car showed the worst value on the highway. On the uneven road the overall ride value level was increased 75~98%. All the vehicles had the SEAT value less than 1. Faster the velocity lowers the SEAT value. The ride quality in terms of vibration gets worst when the backrest angle increased. Conclusion: The smaller car had a first mode at the higher frequency and showed higher vibration level. SEAT value was mostly affected by the seat property not by vehicle. We ranked the luxury car seat had a best vibration reduction quality than others based on SEAT values. When the driving velocity increased, the overall ride values were increased proportionally and the SEAT values were somewhat decreased. Application: Evaluation of whole-body vibration in the passenger car.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.262-270
• /
• 2004

Basic experiments were carried out using the THT-IV low-power Hall thruster to examine the influences of magnetic field shape and strength, and acceleration channel length on thruster performance and to establish guidelines for design of high-performance Hall thrusters. Thrusts were measured with varying magnetic field and channel structure. Exhaust plasma diagnostic measurement was also made to evaluate plume divergent angles and voltage utilization efficiencies. Ion current spatial profiles were measured with a Faraday cup, and ion energy distribution functions were estimated from data with a retarding potential analyzer. The thruster was stably operated with a highest performance under an optimum acceleration channel length of 20 mm and an optimum magnetic field with a maximum strength of about 150 Gauss near the channel exit and with some shape considering ion acceleration directions. Accordingly, an optimum magnetic field and channel structure is considered to exist under an operational condition, related to inner physical phenomena of plasma production, ion acceleration and exhaust plasma feature. A new Hall thruster was designed with basic research data of the THT-IV thruster. With the thruster with many considerations, long stable operations were achieved. In all experiments at 200-400 V with 1.5-3 mg/s, the thrust and the specific impulse ranged from 15 to 70 mN and from 1100 to 2300 see, respectively, in a low electric power range of 300~1300 W. The thrust efficiency reached 55 %. Hence, a large map of the thruster performance was successfully made. The thermal characteristics were also examined with data of both measured and calculated temperatures in the thruster body. Thermally safe conditions were achieved with all input powers.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.10 no.1
• /
• pp.95-102
• /
• 2018

This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes are well-coordinated to add up the lift capabilities of both cranes without any loss such that virtually a single crane is lifting, maneuvering and unloading. Two main constraints for the dual lifting are as follows: First, two barges of floating cranes should be constrained as a rigid body not to cause a relative motion between two barges and main hooks of the two cranes should be controlled as main hooks of a single crane. In order words, it is necessary to develop the cooperative control of two floating cranes in order to sustain a center of gravity of the module and minimize the tilting angle during the lifting and unloading by the two floating cranes. Two floating cranes are handled as a master-slave system. The master crane is able to gather information about all working conditions and make a decision to control the individual hook speed, which communicates the slave crane by TCP/IP. The developed control system has been embedded in the real floating crane systems and the dual lifting has been demonstrated five times at SHI shipyard in 2015. The moving angles of the lifting module are analyzed and verified to be suitable for hoisting control. It is verified that the dual lifting can be applied for many heavier and wider blocks and modules to shorten the construction time of ships and off-shore platforms.

• Applied Microscopy
• /
• v.37 no.2
• /
• pp.53-63
• /
• 2007

The culticular substructure of the venom apparatus in the orb-web spider Araneus ventricosus are studied with scanning electron microscopy. The apparatus is composed of chelicera and paired venom glands in the cephalothorax. Each chelicera consists of a basal segment and a movable fang that articulates with each other. The chelicera of this spider is labidognathous form that moves at right angles to the body axis, and has two segments similar to that of a folding jackknife. Each cylindrical fang has a specialized hinge joint which articulate with the cheliceral groove which contains numerous small protrusions. In addition, each side of cheliceral groove is covered with a total of 7 cuticular teeth in two rows which composed of 4 promarginal and 3 retromarginal teeth. It has been also observed that a single venom pore is always located toward the direction of retromarginal teeth, and surface cuticular pits are distributed on the cuticular depressive area of cheliceral groove.

• Journal of KIISE:Software and Applications
• /
• v.30 no.11
• /
• pp.1092-1101
• /
• 2003

Most of 3D character animation adjusts the gait of their characters for various terrains, using motion capture data through the motion capture equipments. This motion capture data can be naturally presented as real human motions, which are to be adjusted according to the various types of terrain. In addition, there would be a difficulty applying motion capture data for other characters in which the motion data will be captured again or edited for the existing motion data. Therefore, this paper proposes a method that is to generate walking motion for various terrains, such as flat, inclined plane, stair, and irregular face, and a method that is to calculate the trajectory of the swing leg and pelvis. These methods are able to generate various gaits controlled by the parameters of body height, walking speed, stride, etc. In addition, the positions and angles of joint can be calculated by using inverse kinematics, and the cubic spline will be used to calculate the trajectory of the joint.

• PNF and Movement
• /
• v.13 no.1
• /
• pp.39-46
• /
• 2015

Purpose: The accelerometer is a tool for evaluating walking by the displacement of the center of mass (COM) in the body. Recently, smartphones have added an accelerometer app, and it can be used to evaluate outcomemanures in rehabilitation. The purpose of this study was to investigate the COM in the bodies of normal persons and stroke patients using this smartphone application while walking. Methods: Twenty normal persons and twenty-two stroke patients were recruited and had their COM measured using G-walk and the smartphone application, SMAP, during 10 m walking. Subjects repeated the 10 m of walking 3 times, and we used the SMAP, Accelerometer Monitor ver. 1.5.0, to evaluate COM during the walk. To measure the displacement of COM, we used the difference in value between the maximal angle and the minimum anterior-posterior (AP), mediolateral (ML), and rotational angles during the walk. Results: For the normal persons, there was significant correlation between the AP and AP of SMAP, and was also a significant correlation between rotational angle and the ML of SMAP. In the stroke patients, there was significant correlation between AP and ML, and the rotational angle of SMAP. Conclusion: Our research results suggest that if the SMAP system is reinforced in the case of patients who have a greater displacement of COM, it may be used as an evaluation tool during walking.