• The Research Journal of the Costume Culture
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• v.26 no.4
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• pp.632-648
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• 2018

This study aims to contribute to the development of sports wearables. It was conducted by a convergence team of professionals in the fashion industry, kinesiology and sports studies, and computer science and engineering. The purpose of the current study was to design and develop a fabric-type fitness band for a sensor to measure acceleration during jump rope exercises. Computer science and engineering professionals developed the Arduino board and sensor, kinesiology and sports studies provided the necessary exercise protocol, and the fashion industry professionals developed the band. First, a fitness band preference survey was completed by men and women between the ages of 20 and 50. Typical uses of the band included tracking exercise amount as measured by the number of steps taken and calories burned. Strap watch closure, a single color and achromatic color, and soft and smooth touch materials were preferred as band design. Second, two fabric-type fitness bands were designed and developed. Design 1 had a 3-dimensional pocket for the sensor, bright blue color, and stretch binding around the edges and for a loop. Design 2 had a flat pocket for the sensor, achromatic color, mesh binding around the edges and two metal loops. Both designs had Velcro as a closure. Third, wear testing of both bands with the sensor were conducted of 15 women in their 20s. They wore the bands during jump rope exercises. Both bands generally satisfied the participants. The Design 2 band was slightly more satisfying than the Design 1 band.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.344-351
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• 2016

In the point of view of a train operator, the main concern with a train operation is not only to maintain a time schedule, but also to decrease the energy consumption as much as possible. Generally for a manual drive, a train conductor controls the train acceleration and deceleration by controlling the notches not to exceed the regulation velocity by considering the given maximum velocity profile for an operation route. For this case, the guideline for a conductor is needed to choose the proper notches by applying the notch optimization so as to drive at the regulation velocity and minimize energy consumption simultaneously. In this paper, the real-time notch optimization plan is suggested using a genetic algorithm that optimizes the notches for the remaining route in real time when the event occurs that track information or regulation velocity profile of the remaining route changes during train operation as well as a normal operation situation. An energy saving effect and the convergence behavior of the optimal solution obtained was analyzed in a genetic algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.11
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• pp.951-959
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• 2016

The aim of this paper is to investigate the improvement of surface characteristics of Stellite21 deposited layer by powder feeding type of direct energy deposition (DED) process using a plasma electron beam. Re-melting experiments of the deposited specimen is performed using a three-dimensional finishing system with a plasma electron beam. The acceleration voltage and the travel speed of the electron beam are chosen as process parameters. The effects of the process parameters on the surface roughness and the hardness of the re-melted region are examined. The formation of the re-melted region is observed using an optical microscope. Results of these experiments revealed that the re-melting process using a plasma electron beam can greatly improve the surface qualities of the Stellite21 deposited layer by the DED process.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.1
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• pp.10-18
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• 2010

The purpose of this paper deals with direct multiple-shooting method (DMS) to resolve helicopter maneuver problems of helicopters. The maneuver problem is transformed into nonlinear problems and solved DMS technique. The DMS method is easy in handling constraints and it has large convergence radius compared to other strategies. When parameterized with piecewise constant controls, the problems become most effectively tractable because the search direction is easily estimated by solving the structured Karush-Kuhn-Tucker (KKT) system. However, generally the computation of function, gradients and Hessian matrices has considerably time-consuming for complex system such as helicopter. This study focused on the approximation of the KKT system using the matrix exponential and its integrals. The propose method is validated by solving optimal control problems for the linear system where the KKT system is exactly expressed with the matrix exponential and its integrals. The trajectory tracking problem of various maneuvers like bob up, sidestep near hovering flight speed and hurdle hop, slalom, transient turn, acceleration and deceleration are analyzed to investigate the effects of algorithmic details. The results show the matrix exponential approach to compute gradients and the Hessian matrix is most efficient among the implemented methods when combined with the mixed time integration method for the system dynamics. The analyses with the proposed method show good convergence and capability of tracking the prescribed trajectory. Therefore, it can be used to solve critical areas of helicopter flight dynamic problems.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.4
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• pp.191-197
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• 2005

Biped walking is the main feature of a humanoid robot. In a biped walking robot, there are many actuators to be controlled and many sensors to be interfaced. In this paper, we propose a DSP-based controller for a miniature biped walking robot with 21 RC servo motors. The proposed controller has a hierarchical structure; a host PC, a DSP-based main controller, and an auxiliary controller with an FPGA chip. The host PC generates and transmits the robot walking data for given walking parameters such as stride, walking period, etc. The main controller implemented with a TMS320LF2407A controls 21 RC servo motors via the auxiliary controller. We also perform some experiments for balancing motion and walking on a slope terrain with interfacing a 2-axis acceleration sensor and a TMS320LF2407A.

• Journal of Digital Convergence
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• v.9 no.5
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• pp.65-75
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• 2011

For the latest information and communication technology convergence with related technology to integrate all the systems has been developed in the form. In this era as well as the flow of the healthcare industry in recent years many studies on the development and application has been actively. Health IT in healthcare information systems that integrate information systems that have evolved rapidly in the direction to go, and in the future it is expected to do better acceleration. In this paper, state-led ubiquitous environment for building the hospital application system and IT application services are practical and Free in the integrated health information for the patient care service strengthening to integrated medical information system proposal and design do's and At the same time the establishment of integrated health information systems plans and operational challenges presented.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.1
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• pp.15-21
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• 2015

In this paper, a behavior notification system of the harness of a guide dog is implemented for a blind person to get helps for environmental and situational awareness while walking with the guide dog. IMU modules is attached on the guide dog's harness saddle and the acceleration sensor belt is mounted on its thigh. Gait estimation and behavior judgement are performed by recording and analyzing the outputs of the sensors. Performance analysis for seven different kinds of behaviors has been done. The seven different behaviors, which the guide dog recognizes, are descending stairs, climbing stairs, uphill, downhill, stop, flat road, and selective disobedience. Results for the performance analysis show that the average success rate of the behavior rule estimation of harness of the guide dog is 92.78% and the behavior notification system can be effectively used in real situations.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.1
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• pp.45-50
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• 2019

When PPG signal is used in mobile healthcare devices, the accuracy of the measured heartbeat decreases from the influence by the movement of the user. The reason is that the frequency band of the noise overlaps the frequency band of the PPG signal. In order to remove these same noises, the methods using frequency analysis method or application of acceleration sensor have been investigated and showed excellent performance. However, in applying these methods to low-cost healthcare devices, it is difficult to apply these methods because of much processing time and sensor's cost. In order to solve these problems, this study proposed the filter design method using an adaptive notch filter and the fuzzy inference system to extract more accurate heart rate in real time and evaluated its performance. As results, it showed better results than the other methods. Based on the results, when applying the proposed method to design the mobile healthcare device, it is possible to measure the heartbeat more accurately in real time.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.37-43
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• 2018

Science DMZ is a network architecture that considers complicated network components such as dedicated network, DTN, and minimum security policy to maximize transfer efficiency. And DTN tuning is an essential component to take full advantage of Science DMZ's available bandwidth. In addition, tuning of network system should be performed concurrently to minimize packet loss due to network bottleneck. In this paper, we propose a tuning method of data transfer node and network system for maximizing transfer efficiency in Science DMZ network architecture. As a result of the performance measurement using the KREONET, the network performance after the DTN tuning shows 180% improvement than that of existing method without DTN tuning. In addition, performance of 9.4Gb/s was shown without loss of performance measurement after tuning network system applying shaping policy.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.145-151
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• 2019

In this study, the effects were analyzed by applying the vibration absorption liner into the guide rail bracket as a part of method to reduce the vibration and noise on the high-rise apartment. As the result of vibration absorption liner performance, it was checked that the level of vibration and noise was reduced around 65.49% in the car side and around 90.05% in the counterweight side. Therefore, the vibration absorption effect by the vibration absorption liner of elevator guide rail bracket became fairly good. In case of the vibration absorption liner application, there was an effect on the reduction of 7.26 to 22.22% at hoistway section area, 3,840,000 to 9,780000 KRW at the cost of material and installation by comparing with the damping beam application. Also, in case of the vibration absorption liner application with light weight instead of damping beam with heavy weight, it was thought to become significant effect at preventing the safety from the accidents on installation site.