• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.531-532
• /
• 2016

Carpal tunnel syndrome, carpal tunnel becomes part of a narrower median nerve pain occurs pressed. How a stable wrist stretch for the prevention of carpal tunnel syndrome is required, it should life guides to fit the user is provided. In this research, users themselves recognize the risk of carpal tunnel syndrome, to be able to stretch, it implements the application. Application, based on the usage time set by the user, executes the alarm and lock. At this time, the user may utilize arduino and inertia sensor, it is possible to wrist stretch, to analyze usage patterns, it is possible to provide a medical information and life guides to suit the user. Data using Bluetooth 4.0 communication has been to meet the runaway. In order to evaluate the mounted system, targeting four subjects, the time and the touch frequency of usage of the 3-day smartphone measured, as a result of the questionnaire, it reduces the frequency of use of smartphones, a positive it was possible to prove the effect.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.9
• /
• pp.783-790
• /
• 2016

One of the main factors related to the deterioration of estimation accuracy in inertial measurement unit (IMU)-based orientation determination is the object's acceleration. This is because accelerometer signals under accelerated motion conditions cannot be longer reference vectors along the vertical axis. In order to deal with this issue, some orientation estimation algorithms adopt acceleration-compensating mechanisms. Such mechanisms include the simple switching techniques, mechanisms with adaptive estimation of acceleration, and acceleration model-based mechanisms. This paper compares these three mechanisms in terms of estimation accuracy. From experimental results under accelerated dynamic conditions, the following can be concluded. (1) A compensating mechanism is essential for an estimation algorithm to maintain accuracy under accelerated conditions. (2) Although the simple switching mechanism is effective to some extent, the other two mechanisms showed much higher accuracies, particularly when test conditions were severe.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.14 no.3
• /
• pp.371-379
• /
• 2001

This paper deals with the free vibrations of horizontally curved members resting on elastic foundations with continuity effect. Taking into account the effects of rotatory inertia and shear deformation, differential equations governing the free vibrations of such beams are derived, in which the Pasternak foundation model is considered as the elastic foundation with continuity effect. The differential equations are solved numerically to calculate natural frequencies and mode shapes. The experiments were performed in which the natural frequencies of such curved beams in laboratorial scale were measured and these results agree quite well with the present numerical studies. In numerical examples, the circular, parabolic, sinusoidal and elliptic curved members with the hinged-hinged, hinged-clamped and clamped end constraints are considered. The parametric studies are conducted and the lowest four frequency parameters are reported in tables and figures as the non-dimensional forms. Also the typical mode shapes are presented.

• The KIPS Transactions:PartB
• /
• v.12B no.4 s.100
• /
• pp.379-386
• /
• 2005

This paper provides a rigorous theory for analysis of quantization effects and optimum filter bank design in quantized multidimensional subband filter banks. Even though subband filter design has been a hot topic for last decades, a few results have been reported on the subband filter with a quantizer. Each pdf-optimized quantizer is modeled by a nonlinear gain-plus-additive uncorrelated noise and embedded into the subband structure. Using polyphase decomposition of the analysis/synthesis filter banks, we derive the exact expression for the output mean square quantization error. Based on the minimization of the output mean square error, the technique for optimal filter design methodology is developed. Numerical design examples for optimum nonseparable paraunitary and biorthogonal filter banks are presented with a quincunx subsampling lattice. Through the simulation, $10\~20\;\%$ decreases in MSE have been observed compared with subband filter with no quantizers especially for low bit rate cases.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.12
• /
• pp.970-978
• /
• 2002

The differential equations governing free vibrations of the elastic arches with unsymmetric axis are derived in Cartesian coordinates rather than in polar coordinates. in which the effect of rotatory inertia is included. Frequencies and mode shapes are computed numerically for parabolic arches with both clamped ends and both hinged ends. Comparisons of natural frequencies between this study and SAP 2000 are made to validate theories and numerical methods developed herein. The convergent efficiency is highly improved under the newly derived differential equations in Cartesian coordinates. The lowest four natural frequency parameters are reported, with and without the rotatory inertia, as functions of three non-dimensional system parameters the rise to chord length ratio. the span length to chord length ratio, and the slenderness ratio. Also typical mode shapes of vibrating arches are presented.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.9
• /
• pp.688-693
• /
• 2016

This paper describes the parachute dynamics modeling and simulation results for the development of training simulator of a HALO (High Altitude Low Opening) parachute, which is currently in use for military purposes. The target parachute is a rectangular shaped parafoil and its dynamic model is derived based on the real geometry data as the 9-DOF nonlinear equations of dynamics. The simulation was conducted through the moment of inertia and its aerodynamic derivatives to reflect the real characteristics based on the MATLAB/Simulink. In particular, its modeling includes the typical characteristics of the added mass and moment of inertia, which is shown in the strong effects in Lighter-Than-Air(LTA) flight vehicle. The proposed dynamic modeling was evaluated through the simulation under the spiral turning flight conditions of the asymmetric control inputs and compared with the performance index in the target parachute manual.

• Journal of Advanced Navigation Technology
• /
• v.23 no.3
• /
• pp.228-236
• /
• 2019

Recently, multi-sensor integration techniques have been actively studied to obtain reliable and accurate navigation solution in GPS (Global Positioning System)-denied harsh environments such as urban canyons, tunnels, and underground roads. In this paper, we propose a low-cost ultrasonic-speedometer utilizing the characteristics of the ultrasonic propagation. An efficient integrated INS (inertial navigation system)/ultrasonic-speedometer navigation system is also proposed to improve the accuracy of positioning in GPS-denied environments. To evaluate the proposed system, car experiments with field-collected measurements were performed. By the experiment results, it was confirmed that the proposed INS/ultrasonic-speedometer system bounds the positioning error growth effectively even though GPS signal is blocked more than 10 seconds and a low-cost MEMS IMU (micro electro mechanical systems inertial measurement unit) is utilized.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.3B
• /
• pp.325-335
• /
• 2010

The aim of this study is to survey the effects of laying drainage layer in sandy beach on beach stabilization. At first, the numerical model developed by Hur and Lee (2007), which is able to consider the flow through a porous medium with inertia, laminar and turbulent resistance terms, i.e. simulate directly WAve Structure Seabed/Sandy beach interaction and can determine the eddy viscosity with LES turbulent model in 3-D wave field (LES-WASS-3D), is validated by comparing with existing experimental data. And then, numerical simulation is carried out to examine the characteristics of wave-sandy beach interaction for a beach with/without drainage layer. From the numerical results, it is shown that mean ground-water level around a foreshore decreases and offshore-ward flow over a seabed reduces in case of a beach with drainage layer. Moreover, the effects of cross profile of drainage layer and incident wave condition on mean ground-water level around a foreshore are also discussed as well the distribution of wave setup around the foreshore.

• Journal of Yeungnam Medical Science
• /
• v.12 no.1
• /
• pp.84-95
• /
• 1995

A clinical and histopathological study was performed on ninety-four patients with nephrotic syndrome (91 idiopathic and 3 secondary) who were admitted to Department of Internal Medicine, Yeungnam University Hospital during the period of nine years, from January 1985 to May 1994. The results were as following. 1. the ratio of male to female was 1.76:1. In young age group, minimal change was the most predominant type. In old age group, membranous glomerulonephritis and focal glomerulosclerosis were predominant types. 2. The primary nephrotic syndromes were 96.8% and secondary nephrotic syndromes were 3.2%. Histopathologic findings of 94 renal biopsy tissue were classified into minimal change (43.6%), mesangial proliferative glomerulonephritis (29.8%), membranous glomerulonephritis (12.8%), TypeI membranous proliferative glomerulonephritis (4.3%), focal glomerulosclerosis (3.2%) and others (6.4%). 3. The response of eighty-six patients treated with steroid showed complete remission in 51.2%, partial remission in 20.9%, steroid dependent in 2.3%, and no effect in 25.6% of cases respectively. The response to steroid therapy was most effective in the patients with minimal change lesion. 4. In the patient with membranous proliferative glomerulonephlitis, long-term angiotensin converting enzyme inhibitor treatment showed less deterioration of renal function.

• Health Policy and Management
• /
• v.12 no.2
• /
• pp.76-91
• /
• 2002

This study aimed to assess the educational need for management of communicable disease prior to developing curriculum for Field Epidemiology Specialist Training Program on Infectious Disease. We sent questionnaires(72 items) to two personnels who were related to communicable disease in each public health center through e-mai and 300 were returned(62.0% of response rate). The subject for education which showed the highest educational need was management(2.31 point), followed by immunization(2.30 point), and the lowest was surveillance(2.10 point). Generally, the educational need was higher in the aspect of attitude or practice than in that of knowledge. The subject which showed the differences in educational need by job titles were immunization(p<0.01), outbreak investigation(p<0.01), and case management and sanitation(p<0.01). There was negative correlation between communicable disease management-working duration and educational need. Considering this result, the curriculum should be focused on strengthening the ability for problem-solving especially in management and immunization.