• The Journal of Society for e-Business Studies
• /
• v.1 no.1
• /
• pp.141-157
• /
• 1996

Data sharing is a major challenge to implement CALS. STEP is the international standard for the product model data exchange among heterogeneous systems and plays a key role in CALS. Advances in computer networks are rapidly changing the product development processes. The network oriented modeling system premises to integrate design activities across the enterprise. To achieve goals of CALS 3-dimensional concurrent modeling that complies international standard is required since integrity and common perception of product data can be assured. This paper presents 3-dimensional concurrent geometric modeling on high speed network using STEP and methodologies.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.2
• /
• pp.246-251
• /
• 2014

In this paper, a high-speed CMOS Image Sensor (CIS) based on a 10-bit two step Single Slope A/D Converter (SS-ADC) is proposed. The A/D converter is composed of both 5-bit coarse ADC and a 6-bit fine ADC, and the conversion speed is 10 times faster than that of the single-slope A/D convertor. In order to reduce the pixel noise, further, a Hybrid Correlated Double Sampling (H-CDS) is also discussed. The proposed A/D converter has been fabricated with 0.13um 1-poly 4-metal CIS process, and it has a QVGA ($320{\times}240$) resolution. The fabricated chip size is $5mm{\times}3mm$, and the power consumption is about 35 mW at 3.3 V supply voltage. The measured conversion speed is 10 us, and the frame rate is 220 frames/s.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.958-959
• /
• 2015

This paper proposes adaptive incremental conductance(A-IC) algorithm for maximum power point tracking(MPPT) control of photovoltaic. Conventional Perturbation & Observation(PO) and IC MPPT control algorithm generally uses fixed step size. A small fixed step size will cause the tracking speed to decrease and tracking accuracy of the MPP will decrease due to large fixed step size. Therefore, this paper proposes N-IC MPPT algorithm that adjust automatically step size according to operating conditions. To improve tracking speed and accuracy, when operating point is far from maximum power point(MPP), step size uses maximum value and when operating point is near from MPP, step size uses variable step size that adjust according to slope of P-V curve. The validity of MPPT algorithm proposed in this paper prove through compare with conventional IC MPPT algorithm.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.626-628
• /
• 2004

This paper describes an 8-bit CMOS folding A/D converter for set-top box. Modular low-power, high-speed CMOS A/D converter for embedded systems aims at design techniques for low-power, high-speed A/D converter processed by the standard CMOS technology. The time-interleaved A/D converter or flash A/D converter are not suitable for the low-power applications. The two-step or multi-step flash A/D converters need a high-speed SHA, which represents a tough task in high-speed analog circuit design. On the other hand, the folding A/D converter is suitable for the low-power, high-speed applications(Embedded system). The simulation results illustrate a conversion rate of 40MSamples/s and a Power dissipation of 80mW(only analog block) at 2.5V supply voltage.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.5
• /
• pp.1040-1048
• /
• 2013

In this paper, a sensorless pitch angle control method for a wind generation system is suggested. One-step-ahead prediction control law is adopted to control the pitch angle of a wind turbine in order for electric output power to track target values. And it is shown that this control scheme using the inverse dynamics of the controlled system enables us to predict current wind speed without an anemometer, to a considerable precision. The inverse input-output of the controlled system is realized by use of an artificial neural network. The proposed control and wind speed prediction method is applied to a Double-Feed Induction Generation system connected to a simple power system through computer simulation to show its effectiveness. The simulation results demonstrate that the suggested method shows better control performances with less control efforts than a conventional Proportional-Integral controller.

• Journal of Multimedia Information System
• /
• v.6 no.4
• /
• pp.185-190
• /
• 2019

For future autonomous cars, it is necessary to recognize various surrounding environments such as lanes, traffic lights, and vehicles. This paper presents a method of speed sign recognition from a single image in automatic driving assistance systems. The detection step with the proposed method emphasizes the color attributes in modified YUV color space because speed sign area is affected by color. The proposed method is further improved by extracting the digits from the highlighted circle region. A sequential cascade AdaBoost classifier is then used in the recognition step for real-time processing. Experimental results show the performance of the proposed algorithm is superior to that of conventional algorithms for various speed signs and real-world conditions.

• Physical Therapy Korea
• /
• v.15 no.3
• /
• pp.35-43
• /
• 2008

The purpose of this study was to compare spatio-temporal parameters during walking between patients with idiopathic Parkinson's disease and a control group matched for age, height, and weight. Thirty-three subjects were included in this study. Fifteen normal subjects (age, $63.3{\pm}5.8$ yrs; height, $164.1{\pm}8.7$ cm; weight, $60.7{\pm}17.5$ kg) and eighteen patients (age, $64.0{\pm}7.7$ yrs; height, $164.7{\pm}7.3$ cm; weight, $63.6{\pm}7.7$ kg) participated in the study. The Vicon 512 Motion analysis system was used for gait analysis in each group during walking, with and without an obstacle. The measured spatio-temporal parameters were cadence, walking speed, stride time, step time, single limb support time, double limb support time, stride length, and step length. Results in stride length and step length, when walking without an obstacle, showed a significantly greater decrease in the patient group compared to the control group. During walking with an obstacle, the patient group showed a significantly greater decrease in the step length as compared to the control group. For the control group, there were significant decreases in parameters of cadence and walking speed and increases in parameters of stride time, step time, and single limb support time when walking with an obstacle. The patient group had lower cadence and walking speed and higher stride time, step time, and single limb support time during walking with an obstacle than in walking without an obstacle. These results suggest that patients with Parkinson's disease who walk over an obstacle can decrease cadence, stride length, and step length. Further study is needed, performed with more obstacles and combined with other external cues, such as visual or acoustic guides.

• The Journal of the Acoustical Society of Korea
• /
• v.34 no.5
• /
• pp.394-402
• /
• 2015

CMA (Constant Modulus Algorithm) is one of the well-known algorithms in blind acoustic channel equalization. Generally, CMA converges slowly and the speed of convergence is dependent on a step-size in the CMA procedure. Many researches have tried to speed up the convergence speed by applying a variable step-size to CMA, e.g. the orthogonal projection CMA and algebraic optimal step-size CMA. In this paper, we summarize these two algorithms, and we propose a new CMA with improved convergence performance. The improvement comes from the switching between the orthogonal projection CMA and algebraic optimal step-size CMA. In simulation results, we show the performance improvement in the time invariant channels as well as in time varying channel.

• Journal of Korean Physical Therapy Science
• /
• v.10 no.2
• /
• pp.17-28
• /
• 2003

The aim of this study was to investigate the effects of treadmill gait training on the functional characteristics and the temporal-distance parameters of gait in hemiplegic patients, as compared with conventional gait training. The subjects of this study were 32 hemiplegic patients who had been admitted or were visited out-patients at Kangdong Sacred Heart Hospital, Hallym University, from March 3 through April 25, 2003. These subjects were randomly divided into treadmill gait training group or conventional gait training group. We evaluated the gait ability, motor functions, muscle strength, spasticity, physiological cost index, and temporal-distance parameters. We analyzed the changes between pre and post training in each groups, and the difference between two groups. Temporal-distance parameters were obtained using the ink footprint method and then energy consumption using physiological cost index. The results were as follows: 1. After a six-week training, treadmill gait training group significantly improved, as. compared to pre-training, in gait ability, motor functions for the leg and trunk and gross function, muscle strength of the lower limb, gait speed, cadence, step length both on the affected and on the unaffected side, step length symmetry, and energy consumption(p<0.05). 2. After a six-week training, conventional gait training group significantly improved, as compared to pretraining, in gait ability, motor functions for the leg and trunk, muscle strength of the lower limb, spasticity the upper limb, gait speed, cadence, step length both on the affected and on the unaffected side, and energy consumption(p<0.05). 3. After a six-week training, the treadmill gait training group significantly improved, as compared to the conventional gait, training, in gait speed and step length on the unaffected side. These results show that treadmill gait training was improved gait speed and step length on the unaffected side of hemiplegic patients, as compared with conventional gait training. Further research is needed to confirm the generalization of these findings and to identify which hemiplegic patients might benefit from treadmill gait training.

• Journal of Korean Physical Therapy Science
• /
• v.16 no.1
• /
• pp.31-39
• /
• 2009

Background: Community ambulation has been recently recognized as one of the most essential factors of activities of daily living in patients with post-stroke hemiparesis. This study aimed to compare walking velocity and step number in 5 community situations in patients with post-stroke hemiparesis. Methods: Ten chronic stroke patients volunteered for this study. The main variables analyzed were walking speed and step number, and these were measured in 5 different community situations: a physical therapy room, a parking lot, a bank, a crosswalk, and a hospital lobby. The measurements obtained for walking in the physical therapy room were measured using a 10m walk test and were used as baseline data for comparison with each option. The ambulation distance was set at 300m for the parking lot and the bank and 150m for the crosswalk and hospital lobby. For data analysis, walking speed and step number were standardized with the distance options of each ambulation. Results: Compared to the walking speed in the physical therapy room, those in the other situations, except for the parking lot, were significantly different (p<.05). Moreover, there were significant differences in the speeds between the bank and the parking lot and between the parking lot and the crosswalk (p<.05). Compared to the step number in the physical therapy room, those in all situations except for the crosswalk were significantly different (p<.05). Further, there was a significant difference in the step number between the bank and the crosswalk (p<.05). Conclusion: The walking ability of patients with hemiparesis in real environments within a community could be different from that in a physical therapy room. Therefore, the evaluation of walking should be performed in a variety of community situations.