• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1759-1764
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• 2015

In this paper, we considered a design method of a circular polarization (CP) antenna for UHF (ultra high frequency) RFID (Radio Frequency IDentification) readers. The antenna is a dual-fed circular microstrip patch which produces right-handed CP. Quadrature hybrid coupler is used for dual feeding. The outputs of the coupler and circular patch are connected through copper wires, and the inductive reactance produced by the connecting wires is compensated by a ring-shaped slot inserted inside the circular patch. The effects of the geometrical parameters of the proposed antenna on the antenna performance are examined, and the parameters are adjusted to be suitable for the operation in North American UHF RFID band (902-928 MHz), which includes domestic UHF RFID band. The antenna is fabricated, and the experiment results reveal a frequency band of 854-993 MHz for a voltage standing wave ratio < 2. The fabricated antenna is connected to a commercial RFID reader, and it showed a good performance of tag identification.

• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.105-111
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• 2012

The purpose of this study was to investigate the effect that difference in forefoot of shoe flexibility during the quick lunge from a jump smashing on the lower limbs and the plantar pressure distribution. For this 10 elite badminton players with over 10 years experience and right handed participated. Two kinds of badminton shoes were selected and tested mechanical testing for the forefoot flexibility. Motion analysis, ground reaction forces and plantar pressure distribution were recorded. It was required to conduct lunge movement after jumping smashing as possible as high. Photo sensor was located in 3 meter away from standing position and its height was 40 cm. Subjects were conducted to return original position after touching the sensor as under clear movement as possible as fast. Forefoot stiffness had an effect on shoe peak bending degree and peak bending angular velocity in propulsion phase. Forefoot flexibility had an effect on ankle plantar flexion and knee flexion moment. It appears that joint power on lower limb and peak plantar pressure were not influenced by the flexibility of shoes.

• Korean Journal of Applied Biomechanics
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• v.24 no.3
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• pp.301-308
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• 2014

The purpose of this study was to determine whether there are significant differences in kinematic variables and muscle activities of the thumb between two smartphone holding techniques. Twelve right handed university students(age $25.4{\pm}3.9yrs$, height $176.2{\pm}5.1cm$, weight $75.8{\pm}11.4kg$, hand length $19.2{\pm}1.1cm$) who have no musculoskeletal disorder were recruited as the subjects and had experience in using a smartphone for more than one year. Maximum joint angle, angular velocity, muscular activities were determined for each trial. For each dependent variable, paired t-test was used to determine whether there were significant differences between one hand (OH) and two hands ([TH], ${\rho}$ <.05). The results of this study showed that there were no significant differences between OH and TH in the maximum joint angle of the thumb. The angular velocity of each joint was not statistically significant between OH and TH. The statistical analysis revealed that the main effect of the smartphone holding conditions was significant in the peak normalized muscular activities of FDI and APL. Although smartphone holding technique doesn't affect on mobility and movement of the thumb joint, it may affect on active degree of the thumb and the upper extremity in directly and indirectly.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.2
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• pp.281-287
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• 2013

PURPOSE: The study was designed to investigate the effects of visual, auditory, and visuoauditory cues on simple Serial Task Performance in heaithy adults. METHODS: Sixty-three right-handed heaithy adults without history of neurological dysfunction were participated. A modified version of the Serial Reaction Time Task (SRTT) using five blocks of perceptual motor sequences was administered. The blocked paradigm consisted of the five blocks with randomly repeated 8 digit sequences with 5 repetition. Three types of sensory cue were employed: visual cue, auditory cue and visuoauditory cue. All subjects were assigned to press the matched botton as quickly and accurately as possible, when one of 8 stimulations was presented(one, two, three, four, five, six, seven, eight). The reaction time, accuracy, and P300 latency were measured during serial task performance. The mean reaction time(ms), accuracy(%), and P300 latency(ms) were compared between three types of cue using ANOVA. RESULTS: The reaction time to auditory cue was significantly longer than visual and visuoauditory cues(p<.001). And accuracy to auditory cue was significantly lower than visual and visuoauditory cues(p<.001). All P300 latency(at Fz, Cz, Pz) were significantly longer than to visual and visuoauditory cues(p<.05). CONCLUSION: It is suggested that type of cues influence in choice reaction. These data may helpful in designing not only effective motor learning training programs for healthy persons but also reeducation programs for patients with neurological dysfunction.

• Proceedings of the Korean Society for the Gifted Conference
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• 2003.05a
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• pp.137-138
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• 2003

Understanding how and why people differ is a fundamental, if distant, goal of research efforts to bridge psychological and biological levels of analysis. General fluid intelligence (gF) is a major dimension of individual differences and refers to reasoning and novel problemsolving ability. A conceptual integration of evidence from cognitive (behavioral) and anatomical studies suggeststhat gF should covary with both task performance and neural activity in specific brain systems when specific cognitive demands are present, with the neural activity mediating the relation between gF and performance. Direct investigation of this possibility will be a critical step toward a mechanistic model of human intelligence. In turn, a mechanistic model might suggest ways to enhance gF through targeted behavioral or neurobiological intervent ions, We formed two different groups as subjects based on their scholarly attainments. Each group consists of 20 volunteers(aged 16-17 years, right-handed males) from the National Gifted School and a local high school respectively. To test whether individual differences in general intelligence are mediated at a neural level, we first assessed intellectual characteristics in 40 subjects using standard intelligence tests (Raven's Advanced Progressive Matrices, Wechsler Adult Intelligence Scale, Torrance Tests of Creative Thinking) administered outside of the MR scanner. We then used functional magnetic resonance imaging (fMRl) to measure task-related brain activity as participants performed three different kinds of computerized reasoning tasks that were intended to activate the relevant neural systems. To examine the difference of neural activity according to discrepancy in general intelligence, we compared the brain activity of both extreme groups (each, n=10) of the participants based on the standard intelligence test scores. In contrast to the common expectation, there was no significant difference of brain region involved in high-g tasks between both groups. Random effect analysis exhibited that lateral prefrontal, anterior cingulate and parietal cortex are associated with gF. Despite very different task contents in the three high-g-low-g contrasts, recruitment of multiple regions is markedly similar in each case, However, on the task with high 9F correlations, the Prodigy group, (intelligence rank: >99%) showed higher task-related neural activity in several brain regions. These results suggest that the relationship between gF and brain activity should be stronger under high-g conditions than low-g conditions.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.4
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• pp.198-205
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• 2005

In this paper, the miniaturization of aperture-coupled RHCP patch antenna for the GPS system is treated. Circularly polarization characteristics is implemented by truncating diagonal corners of the square patch. Antenna size is reduced by inserting four uniform slits at the patch edges, which was equivalently lengthened the surface current by meandering it, This antenna uses aperture-coupled feeding structure with crossed-slot shape in order to give easy miniaturization of RHCP patch antenna. Simulated and measured results show that $42.7\%$ lower antenna size is obtained, and also $56\%$ lower -10dB bandwidth and $38.5\%$ lower 3dB AR bandwidth are obtained. when the proposed design scheme is applied to a commercial GPS antenna structure, $42.9\%$ lower patch size and $56\%$ lower 3dB AR bandwidth compared to commercial antenna at the same frequency are obtained.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.12
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• pp.1402-1407
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• 2007

This paper presents a new design method of the Ultra-Wide-Band BandPass Filter using the CRLH-TL(Composite Right- and Left-Handed Transmission-line) having the Metamaterials' properties. Instead of the periodic type or many cells of the CRLH-TL, only the unit cell is used to miniaturize the target component, which can not be realized by the conventional quarter guided-wavelength resonator-based filters. Particularly, the strong coupling essential to the Ultra Wide Band is enabled by the interdigital coupled lines between the grounded stubs. The proposed design scheme is validated by the electromagnetic simulation and measurement of the fabricated filter which shows the total size of 'the guided-wavelength/9.4', the 100 % fractional bandwidth for the UWB, the insertion loss of less than 1 dB and the flat group-delay.

• Polymer(Korea)
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• v.25 no.2
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• pp.279-292
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• 2001

Two kinds of (hydroxypropyl)cellulose(HPCs) with different molar substitution (MS) and three types of derivatives based on the HPCs: (acetoxypropyl)celluloses, (ethoxypropyl)celluloses, and (cyanoethoxyprofyl)celluloses were synthesized, and their thermal and mesomorphic properties were investigated. All samples, which exhibit cholesteric reflection colours at room temperature, formed right-handed helicoidal structures whose optical pitches (λ$_{ms}$ ) increase with temperature. However, the isotropization ($T_{i}$) and glass temperatures, the magnitude of λ$_{m}$ of the mesophase at the same temperature, and the temperature dependence of λ$_{m}$ of the investigated derivatives highly depended on MS and the length and structure of the side chain introduced in HPC. The results were discussed in terms of the difference in the polarity and flexibility of the substituents and the distance between the main chains. For all derivatives, Am values approached infinity at temperatures above the $T_{i}$, of the mesophase, and no reversal in the sense of the pitch with temperature was detected.

• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.149-154
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• 2010

Intentional draw and fade shots could be good weapons for lowering golf score. But how to make such shots? To investigate deterministic variables generating different projectile paths of shots in square stance was the purpose of this study. Ten right-handed male collegiate athletes, showing 1.3 of averaged handicap, participated in this study. They were asked to intentionally perform three different shots such as the straight shot(control condition), draw shot, and fade shot. Swing path, pelvis rotation angle, thorax rotation angle and left forearm supination angle were determined for dependent variables on impact event at each trial. For statistical analysis one-way repeated measures ANOVA were used. The results showed that swing path was one of main factor making differences among three kind of shots. Straight shot vs. Draw shot, Straight shot vs. Fade shot and Draw shot vs. Fade shot showed differences on swing path. And left forearm supination angle revealed significant difference between draw shot and fade shot, showing a significant larger angle of draw shot than fade shot. No other significant difference was detected for the other variables. We found that the shot characteristics were influenced primarily by swing path and left forearm supination angle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.695-700
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• 2011

Age, growth, and maturity of Trichiurus lepturus were estimated based on right-handed sagittal otoliths belonging to 1,031 fish collected from January to December 2007 in the East China Sea. The outer margins of the otolith were examined and showed that an opaque zone was formed once per year. Marginal increments in otoliths formed as annual rings between June and August, at the beginning of the spawning season. Fish growth was expressed by the von Bertalanffy growth equation, as follows: $L_t=494.0$ ($1-e^{-0.2453(t+-0.4822)}$) for females and $L_t=330.4$ ($1-e^{-0.4292(t+0.7513)}$) for males, where $L_t$ is the total length in mm and t is age in years. The growth rates of males and females were significantly different (P<0.05).The age composition ranged mostly between ages 2 and 4, and the oldest individuals were 4 years old in males and 6 years old in females. Finally, the age composition of largehead hairtail was compared with data from the 1970s and is discussed in the context of environmental changes.