• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.11
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• pp.1069-1076
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• 2007

The purpose of this study is to improve the performance of a linear feeder that can transport grains uniformly. In order to analyze the dynamic behaviors of a linear feeder, the displacements of the feeder are measured by several accelerometers when it is in an operating condition. After the signal data from the accelerometers are captured in the time domain, the feeder motion in the space is visualized by using graphic computer software. In addition, a dynamic model of the feeder is established for a multi-body dynamics simulation. For the dynamic simulation, RecurDyn, which is a commercial multi-body dynamic package, is used. From the experimental and the computational approaches, an optimal dynamic motion is obtained for uniform transportation of grains. Furthermore, we also consider the determination of design parameters for optimal dynamic motion such as centroid, stiffness, and damping coefficient of the feeder system.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.248-251
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• 1995

Nowadays, the internal images of a human body can be easily provided by the ultrasound imaging, the X-ray CT, or the MRI device, among which the ultrasound imaging device has good resolution for soft tissues of a human body compared with the other devices. Furthermore, the use of ultrasound imaging devices will increase in future especially in the obstetrics, territory, since it does not give harm to the human body. Although several techniques have been investigated until now in order to extract organs from ultrasound images, very few of them have achieved satisfactory results because of low contrast and high noise nature of images. This paper proposes a technique for automatic extraction of the gall bladder area from ultrasound images. The proposed technique first extracts a small reliable area of a gall bladder from an ultrasound image employing smoothing, binarization, expanding and shrinking, and labeling, and then expands the area referring to the binarized version of the original image. The technique is examined its performance by real ultrasound images of a gall bladder and satisfactory results are obtained. Some problems to be solved are discussed finally.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.3
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• pp.234-239
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• 2013

There are many types of speed reducer for industrial uses. However the cycloid speed reducer is widely used in manipulators based on excellent performance of low backlash, high reduction ratio and compact size. It is essential to use precision speed reducer for accuracy of position controls on robot systems and electric vehicles. The cycloid speed reducer has a eccentric rotating motion and offset to avoid some problem of assembly, so it has a disadvantage for vibration. In this paper, a multi-body dynamic model is developed for a cycloid speed reducer and the dynamic behaviors of the reducer are investigated. The cycloid speed reducer consists of cycloidal plate gears, housing gear, input shaft, output pin and shaft, and eccentric bearings. Using a CAD program, each component of cycloid reducer is modeled based on the offset and eccentric. Multi-body simulations using Recurdyn and test using a rig tester are performed. As a result, the pin reaction force and the amplitude of housing displacement are increased by the larger offset and smaller eccentric value of cycloid reducer.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.781-792
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• 2016

This paper presents a new approach to enhance the data retention of logic-compatible embedded DRAMs. The memory bit-cell in this work consists of two logic transistors implemented in generic triple-well CMOS process. The key idea is to use the parasitic junction capacitance built between the common cell-body and the data storage node. For each write access, a voltage transition on the cell-body couples up the data storage levels. This technique enhances the data retention and the read performance without using additional cell devices. The technique also provides much strong immunity from the write disturbance in the nature. Measurement results from a 64-kbit eDRAM test chip implemented in a 130 nm logic CMOS technology demonstrate the effectiveness of the proposed circuit technique. The refresh period for 99.9% bit yield measures $600{\mu}s$ at 1.1 V and $85^{\circ}C$, enhancing by % over the conventional design approach.

• Journal of computational fluids engineering
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• v.21 no.3
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• pp.71-76
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• 2016

In speed skiing, aerodynamic forces play an important role in determining performance of the skier. To predict aerodynamic effects of the posture of the skier on alpine downhill skiing, we constructed equation of motion of the skier and performed the corresponding CFD simulations. Comparing drag and lift of three different skier postures, it has been shown that drag decreases significantly by tucking upper body to lower body and stretching arms forward. Also, aerodynamic lift which worked as downforce in standing posture worked upward in tuck posture, reducing friction force between snow and ski. This indicates that tuck posture have advantages over standing posture in dual mechanism, namely by reducing drag and also increasing lift. By this two-dimensional initial study we could reveal the general tendency of the aerodynamic force over the skier's body. This study not only provides a theoretical foundation for the athletes to understand the aerodynamic effects of skier postures but also shed a light on towards more accurate and rational three-dimensional CFD simulation of skiers in the near future study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.745-749
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• 2017

We investigated the effects of different dietary lipid levels (7% or 14%) and feeding frequency (1-4 meals per day) on the growth performance and body composition of juvenile fancy carp Cyprinus carpio var. koi. Three replicate groups of fish (initial mean weight, 11.7 g) were fed to visual satiety with sinking dry pellet diets for 8 weeks. Neither feeding frequency nor lipid level affected fish survival. Weight gain was affected by feeding frequency but not dietary lipid level. Weight gain significantly increased with increased feeding frequency. Feed efficiency and protein efficiency ratio were affected by feeding frequency, but not dietary lipid level. Daily feed intake was affected by feeding frequency and dietary lipid level. Whole body moisture, crude lipid and ash contents were affected by feeding frequency, but not dietary lipid level. Based on these results, we conclude that the appropriate feeding frequency for the optimum growth of fancy carp fingerlings is four meals per day using sinking dry pellet.

• Journal of Korea Multimedia Society
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• v.20 no.11
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• pp.1729-1740
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• 2017

This paper describes a vision-based method that effectively recognize a traffic light. The method consists of two steps of traffic light detection and discrimination. Many related studies have used color information to detect traffic light, but color information is not robust to the varying illumination environment. This paper proposes a new method of traffic light detection based on intensity and saturation. When a traffic light is turned on, the light region usually shows values with high saturation and high intensity. However, when the light region is oversaturated, the region shows values of low saturation and high intensity. So this study proposes a method to be able to detect a traffic light under these conditions. After detecting a traffic light, it estimates the size of the body region including the traffic light and extracts the body region. The body region is compared with five models which represent specific traffic signals, then the region is discriminated as one of the five models or rejected as none of them. Experimental results show the performance of traffic light detection reporting the precision of 97.2%, the recall of 95.8%, and correct recognition rate of 94.3%. These results shows that the proposed method is effective.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.584-588
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• 2019

Wireless body area network (WBAN) is a networking technology that enables early detection of abnormal health conditions, real-time medical monitoring, and telemedicine support systems. The internet of things (IoT) for healthcare, which has become an issue recently, is one of the most promising areas for improving the quality of human life. It must meet the high QoS requirements of the medical communication system like any other communication system. Therefore, the bit error rate (BER) threshold was chosen to accommodate the QoS requirements of the WBAN communication system. In this paper, we calculated BER performance of WBAN channel using IR-UWB PPM modulation and analyzed link budget and system margin of WBAN according to various system parameters.

• Journal of the Korean Society of Costume
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• v.58 no.6
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• pp.158-171
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• 2008

The purpose of the study was to examine how changes of women's sexual identity and gender role were expressed in designs of dance costumes by analyzing costumes used in creative dance works. Related articles, dance magazines, Internet information and dance costumes were used for the analysis of various performance cases to express persona and animus of a woman. The results of the study were as follows: 1. As a woman's role, persona, has recently changed into active propensity, dance directors have come to prefer bold and daring image of female dancer to strongly express animus, the masculine inclination of a woman. 2. Female dancers' costumes were frequently associated with daring body exposure such as body painting on half-naked body, to reflect the above and a number of female dancers dressed daringly in masculine style trom head to toe. Also, pants or hot pants instead of skirt were frequently used as dance costumes to symbolize animus. In addition, colors in dance costumes became vivid and bold in comparison to the simple and soft colors used in the past.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.159-164
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• 2015

A feeding experiment was conducted to determine the effect of dietary distillers dried grain (DDG) on the growth and body composition of juvenile abalone, Haliotis discus hannai. Three diets were formulated to contain 0% (DDG0), 30% DDG (DDG1) replacing wheat flour and 30% DDG (DDG2) replacing fish meal and wheat flour. A commercial feed (CF) was also compared with experimental diets. Three replicate groups of abalone averaging $0.6{\pm}0.01g$ were fed one of the four diets for 14 weeks. The highest survival rate was observed in the abalone fed the DDG2 diet, which was higher than that of abalone fed the DDG0 diet. Weight gain, shell length, shell width and soft body weight of the abalone were not affected by dietary DDG and CF diet (P > 0.05). Proximate and amino acid composition of the soft whole body were not affected by dietary DDG and CF diet (P > 0.05). The result of this experiment suggests that DDG is a good ingredient to replace fish meal and wheat flour in the diet and could be used up to 30% in the diet without negative effects on the growth performance of juvenile abalone Haliotis discus hannai.