• Journal of Biomedical Engineering Research
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• v.38 no.4
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• pp.143-152
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• 2017

The main purpose of this research was to examine the EMG characteristics of driver's upper limb and driving performance for operating accelerator and brake pedal by using four types of left hand control devices(Push/Pull, Push/Right angle, Push/Rock, Push/Twist) during simulated driving. The persons with disabilities in the lower extremity have problems in operation of the vehicle because of functional impairments for controlling accelerator and brake pedal. Therefore, if hand control device is used for adaptive driving controls in persons with lower extremity loss, the disabled people could improve their quality of mobility life by driving a car. Twenty subjects were involved in this research to assess driving performance and EMG activities for operating accelerator and brake pedal by using four types of left hand controls in driving simulator. We measured EMG responses of six muscles(posterior deltoid, middle deltoid, biceps, triceps, extensor carpi radialis, and flexor carpi radialis) during pulling and pushing movement with four types of left hand controls for acceleration and braking. STISim Drive 3 program was used for evaluation test of four types of left hand control devices in straight lane course for time to reach target speed and brake reaction time. While operating the four types of left hand controls for acceleration, EMG activities of posterior deltoid in normal subjects were significantly increased(p < 0.05) compared to the disabled subjects. It was also found that EMG responses of triceps and posterior deltoid were significantly increased(p < 0.05) when using the Push/Right angle type than Push/Pull type. While operating the four types of left hand controls for braking, EMG activities of flexor carpi radialis and triceps in subjects with disability were significantly increased(p < 0.05) compared to the normal subjects. It was shown that muscle responses of posterior deltoid, middle deltoid and triceps were significantly increased when using the Push/Right angle type than Push/Rock type. Time to reach target speed and brake reaction time in subjects with disability was increased by 2.5% and 4.6% on average compared to normal subjects. The person with disabilities showed a tendency to relatively slow performance in acceleration at the straight lane course.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.162-167
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• 2008

To enhance the control efficacy against cockroaches in dwelling space, repellent ("Push") was set down on one comer and a poison bait including attractant ("Pull") was on the opposite side. And we tested the control efficacy of Push-Pull strategy by behavior-stimuli of cockroaches. In a mini-field test, German cockroach males primarily chose shelters nearest to the attractant-treated surfaces and farthest from the repellent-treated surfaces. The consumption of food or bait was also highest from food nearest to the preferred shelters by push-pull effect. We evaluated the push-pull insecticidal efficacies of five essential oils belong to Citrus plant, namely, grapefruit, lemon, lime, orange, and petitgrain. The combined push-pull treatments appeared to be faster and higher insecticidal effects than single (pull) treatment, and the repellent efficacy of Citrus oils was in the order of grapefruit > lemon > lime > orange > petitgrain. Therefore, we propose the effective control of the german cockroach using Citrus oils as repellents and push-pull method into a limited area.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.356-367
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• 2000

The purpose of this study was to identify the underlying dimensions of push and pull motivators for Soraksan, Kayasan, Naejangsan, and Pukhansan national parks in mountain regions. This study also examined the nature and extent of the reciprocal relationship between the push and pull factors. The result showed that four dimensions were derived from 12 push items, which were cultural and natural experience, escape and rest, health, and socialization and novelty motivators. Three dimensions also were derived from 12 pull items, which were facilities and culture, nature, and accessibility. The push and pull dimensions were correlated and regressed against each other. Given the nature of relationship between the push and pull factors, facilities and culture pull factor was affected by the cultural and natural experience motivation. Nature pull factor had strongly associated with culture and nature, escape and rest, health, and socialization and novelty motivations. Finally, accessible attraction pull factor had a positive relationship with health motivator, however, had a negative with cultural and natural experiencing motivation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.2
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• pp.71-82
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• 2005

The couple force of the scapular stabilizers for upward rotation that include the upper and lower trapezius, serratus anterior muscles is essential to maintain the stability of shoulder joint. But if there is an imbalance of these muscles, it would occur many problems of shoulder joint. A push-up plus exercise with an unstable support is used in order to increase the muscle activity and stimulate the proprioception of shoulder joint. The purpose of this study was to compare the muscle activity of upper and lower trapezius, serratus anterior muscles and to determine which exercise is more effective when subjects perform push-up plus exercise in the stable support and unstable support. 15 healthy subjects and 15 painful subjects with injury of shoulder joint participated in this study. Surface electromyography data were collected during plus phase of push-up plus exercise. The types of push-up plus exercise were composed of three conditions. Stable type is subjects performed the push-up plus exercise on the fixed support and unstable type 1 is on the sling without shaking and unstable type 2 is on the sling with shaking by tester's manual. The upper and lower trapezius activities of injured group were higher than uninjured group at three measure conditions, but serratus anterior activities were not. The UT/SA ratio of injured group was higher than uninjured group at three measure conditions. The serratus anterior activities were most high at unstable 2 measure in both groups. The UT/SA ratio was most low at unstable 2 measure condition in injured group only. The present result revealed that push-up plus exercise in the unstable support with shaking which took most high serratus anterior activities and most low of UT/SA ratio is optimal cure method that can improve the imbalance of the scapular stabilizer.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.9
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• pp.71-80
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• 2007

This paper presents a new push-push VCO technique that extracts a second harmonic output signal from a capacitive commonnode in a negativegm oscillator topology. The generation of the $2^{nd}$ harmonics is accounted for by the nonlinear current-voltage characteristic of the emitter-base junction diode causing; 1) significant voltage clipping and 2) different rising and falling time during the switching operation of core transistors. Comparative investigations show the technique is more power efficient in the high-frequency region that a conventional push-push technique using an emitter common node. Prototype 12GHz and 17GHz MMIC VCO were realized in GaInP/GaAs HBT technology. They have shown nominal output power of -4.3dBm and -5dBm, phase noise of -108 dBc/Hz and -110.4 dBc/Hz at 1MHz offset, respectively. The phase noise results are also equivalent to a VCO figure-of-merit of -175.8 dBc/Hz and -184.3 dBc/Hz, while dissipate 25.68mW(10.7mA/2.4V) and 13.14mW(4.38mA/3.0V), respectively.

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.303-306
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• 2003

• Journal of the Korean Chemical Society
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• v.66 no.6
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• pp.521-525
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• 2022

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.2
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• pp.137-144
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• 2016

The aim of this study was to evaluate the effect of a range of acidic pH values on the push-out bond strength and surface morphology of tricalcium silicate materials: Biodentine$^{(R)}$, Theracal$^{(R)}$ and ProRoot MTA$^{(R)}$. The standardized lumens of root slices prepared from extracted single-root human teeth were filled with Biodentine$^{(R)}$, Theracal$^{(R)}$ and ProRoot MTA$^{(R)}$ according to manufacturer's instructions. The specimens were randomly divided into 4 groups (n = 20) for each material and then incubated for 4 days at $37^{\circ}C$; 3 acidic groups (butyric acid buffered at pH 4.4, 5.4, 6.4) and 1 control group (phosphate buffered saline solution at pH 7.4). The push-out bond strengths were then measured by using a universal testing machine and the surface morphology of each experimental group was analyzed by a scanning electron microscope. Biodentine$^{(R)}$ and Theracal$^{(R)}$ showed higher push-out bond strength compared with ProRoot MTA$^{(R)}$ after exposure to acidic pH values. A substantial change in the surface morphology of each material occurred after exposure to different pH values. In conclusion, the push-out bond strengths of Biodentine$^{(R)}$ and Theracal$^{(R)}$ are higher than the ProRoot MTA$^{(R)}$. Further the acidic environment weakens the push-out bond strength and microstructure of tricalcium silicate materials.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.209-218
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• 2019

This study was conducted to develop a technology for environmentally friendly control of sweet-potato whitefly, Bemisia tabaci, by controlling their behavior using a push-pull strategy in a tomato greenhouse. B. tabaci was attracted the most by yellow color, light source of 520 nm, whereas it avoided the complex light treatment of 450 + 660 nm. The two natural enemies of B. tabaci, Cyrtopeltis tenuis and Orius laevigatus, were attracted the most by 520 nm light source. B. tabaci was repelled by the volatile organic compounds ocimene and carvacrol and was the most attracted by methyl isonicotinate. When buckwheat was added into the tomato greenhouse, the density of C. tenuis was maintained at about 16 times higher than when untreated for 15 days. As a result of the combined treatment of push-pull strategy, the density per trap of B. tabaci was three times lower than when no treatment was applied, and the control of this pest increased with time and reached up to 68.7%.

• Korean Journal of Social Welfare Studies
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• v.43 no.2
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• pp.141-178
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• 2012

Although the rate of self-employment is high in Korean labor market and the rate gap between age groups is high, few studies have addressed on the effects of push factors on transition into self-employment across age groups. The goal of this research is to determine if push factors exert different effects on the self-employment decisions across age groups. There is interest in testing push hypothesis and pull hypothesis. The Korean Labor and Income Panel Study wave 6~11 is used to test this study's hypothesis. The main contribution of the paper is that in case of high unemployment, the probability of transition into self-employment increases. It is consistent with the push hypothesis. Many people are forced to become self-employed person due to the high rate of unemployment and limited occupational choice rather than the role of entrepreneurship. By age subgroup, the transition into self-employment of the ages of 30 and 49 is high. In addition, people at 40-49 years of age are more likely to become self-employed as a response of inadequate job opportunities. It provides the evidence that the self-employment is not a matter of special age group in that people in the 30 to 49 year old age group whose economic activities are vigorous move into marginalized labor market. Furthermore, it seems to be threatened the employment's stability of the prime age in that even people who are age 40-49 years of age are pushed into self-employment because of the recession.