• Journal of the Korean Society of Clothing and Textiles
• /
• v.47 no.1
• /
• pp.123-136
• /
• 2023

To develop smart sportswear capable of measuring biometric data, we created a close-fitting pattern using two- and three-dimensional (2D and 3D, respectively) methods. After 3D virtual fitting, the tightness of each pattern was evaluated using image processing of contact points, mesh deviation, and cross-sectional shapes. In contact-point analysis, the 3D pattern showed high rates of contact with the body (84.6% and 93.1% for shirts and pants, respectively). Compared with the 2D pattern, the 3D pattern demonstrated closer contact at the lower chest, upper arm, and thigh regions, where electrocardiography and electromyography were primarily carried out. The overall average gap was also lower in the 3D pattern (5.27 and 4.66 mm in shirts and pants, respectively). In the underbust, waist, thigh circumference, and mid-thigh circumference, the cross-section distance between clothing and body was showed a statistically significant difference and evenly distributed in the 3D pattern, exhibiting more closeness. The tightness and fit of the 3D smart sportswear sensor pattern were successfully evaluated. We believe that this study is critical, as it facilitates the comparison of different patterns through visualization and digitization through 3D virtual fitting.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.31 no.3 s.52
• /
• pp.253-257
• /
• 2005

Assurance of the objectivity and reproducibility is a major key point in wrinkle measurement used for evaluating the degree of skin aging. The measurement of relief is quickly converted to a non-contact method, of which tools or instruments do not come in contact with skin directly, to minimize the artificial effects which influence the shape or depth of the relief. Here, we showed how wrinkle measurement techniques have been changed briefly and compared PRIMOS and replica method in the point of view of measurement principle and features, the former is non-contact fringe projection tool and the latter is contact type of the method.

• International Journal of Railway
• /
• v.6 no.4
• /
• pp.148-154
• /
• 2013

This article has tried to review the maximum contact stresses in the contact area of the wheel and rail as a result of lateral movement of the wheel on rail by taking advantage from Hertz theory. Since wheel movement on rail is accompanied by lateral movement due to wheel profile conisity, so the contact point of wheel and rail is not constant and the contact stresses are therefore changeable in every single moment. Since the shape of rail profile and rail inclination, wheel diameter and the mechanical properties of the wheel and rail are effective on the stresses of contact area, these parameters have been studied by applying Hertz theory. This article aims to calculate the contact stresses in different parts on the wheel surface by using Hertz theory.

• 한국초전도학회:학술대회논문집
• /
• v.11
• /
• pp.23-23
• /
• 2001

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.11
• /
• pp.4145-4162
• /
• 2021

During the period of epidemic prevention and control, contact tracing systems are developed in many countries, to stop or slow down the progression of COVID-19 contamination. However, the privacy issues involved in the use of contact tracing apps have also attracted people's attention. First, we divide contact tracing techniques into two types: Bluetooth Low Energy (BLE) based and Global Positioning System (GPS) based techniques. In order to clear understand the system structure and its elements, we create data flow diagram (DFD) of each types. Second, we analyze the possible privacy threats contained in various types of contact tracing apps by applying LINDDUN, which is a threat modeling technique for personal information protection. Third, we make a comparison and analysis of various contact tracing techniques from privacy point of view. These studies can facilitate improve tracing and security performance to contact tracing apps through comparisons between different types.

• Tribology and Lubricants
• /
• v.19 no.1
• /
• pp.1-8
• /
• 2003

Recently, PM-high speed steel(PM-HSS) has reportedly been a good alternative material for rolling mill because of its superior performance to conventional HSS. This paper has been aimed to investigate the possibility for application to rolling contact element for PM-HSS by X-ray diffraction technique. The X-ray elastic constant for PH-HSS has been found by X-ray diffraction during the four-point bending test. Residual stress and half-value breadth on the contact surface during rolling contact fatigue process by X-ray diffraction have also been measured. The result of this study shows that the application of X-ray diffraction technique to PM-HSS could be as possible alternative material as conventional HSS. Half-value breadth on rolling contact surface by X-ray diffraction is not changed during rolling contact fatigue process. On the other hand, the residual stress is changed. This suggests that dislocation reaction has been hardly occurred in rolling contact, depending on super-saturated carbon in PM-HSS.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.12
• /
• pp.1256-1261
• /
• 2008

This paper proposes a way to measure the displacement of a multi-point by using a pattern recognition from video signal. Generally in measuring displacement, gab sensor, which is a displacement sensor, is used. However, it is difficult to measure displacement by using a common sensor in places where it is unsuitable to attach a sensor, such as high-temperature areas or radioactive places. In this kind of places, non-contact methods should be used to measure displacement and in this study, images of CCD camera were used. When multi-point is measure by using a pattern recognition, it is possible to measure displacement with a non-contact method. It is simple to install and multi-point displacement measuring device so that it is advantageous to solve problems of spatial constraints.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.5 s.122
• /
• pp.427-436
• /
• 2007

The catenary of a high-speed electrical train is modeled by the finite elements with the upper suspension wire, lower contact wire, and droppers, and the dynamic contact between the catenary and the pantograph is numerically analyzed by solving the whole equations of motion of the pantograph and the catenary system subjected to the contact condition. For the stability of the numerical solution, with the cubic spline interpolation of the catenary displacement, the velocity and acceleration constraints as well as the displacement constraint are imposed on the contact point. Through the various numerical examples, it is shown that the dropper positions as well as the static deflection are crucial to determine the contact and separation of the pantograph of a high-speed train.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.40 no.8
• /
• pp.825-835
• /
• 1991

This paper deals with a case for robotic hands to grasp the objects using inner link contact as well as fingertip contact. And the case is proved to be more efficient than the case of using only fingertip contact in terms of stability and uniform distribution of the contact forces. The general algorithm for the determination of the optimal ocntact force is developed for the soft finger contact as well as the point contact with friction. To show the validity of the proposed algorithm a numerical example is illustated by employing a robotic hand with three fingers each of which has four joints.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.8 no.2
• /
• pp.73-79
• /
• 1999

Most of mechanical structures are combined of substructures such as beams and/or plates. There are few systems with unibody structures but are many systems with united body structures. Generally the dynamic a nalysis of whole structures is performed under alternation load. In the structure design, the analysis of each bolted joint is more important than others for zero severity. This paper presents the analysis method of contact stress distribution factor in the bolted joint with variable fastening torque on joints in the structure. At first, a static vibration test was performed to find out a nominal stress of bolt jointed plates from the relationship between natural frequency and nominal stress. Then a contact stress was computed at contact point between bolt and plate in the structure. It is believed that the proposed method has promisiong implications for safer design with index of contact stress distribution factor and has merits for cost-down and saving time at the beginning of vehicle development.