• Journal of the Korean Society of Physical Medicine
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• v.8 no.3
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• pp.407-415
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• 2013

PURPOSE: This study is to examine the effects of different types of tasks on gait functions of chronic stroke patients when different types of dual tasks were applied while the patients were implementing practical and continuous circuit tasks using their upper and lower extremities circulating many workbenches. METHODS: Forty-four chronic stroke patients were divided into a dual motor circuit task training group, a dual cognitive circuit task training group and a simple task training group. Before training, all the patients were identically encouraged to receive conservative physical therapy for 30 minutes by a physical therapist were thereafter made to train for 30 minutes, five times a week for a total of eight weeks with individual additional tasks. The dual motor circuit task training consisted of continuous circuit training motor tasks and additional motor tasks and the dual cognitive circuit task training consisted of tasks combining the same circuit training motor tasks and additional cognitive tasks. The simple task training consisted of natural walks on a flat terrain to the front, rear and lateral sides of the terrain. Changes in functional gait abilities made through the training were evaluated using GAITRite. SPSS Win 12.0 was used for the data analysis. RESULTS: As for the gait variables that showed significant differences in comparison between the groups over the training period, the dual motor circuit task training group showed more significant differences than the dual cognitive circuit task training group and the simple task training group at 4 weeks and 8 weeks of training(p<.05). CONCLUSION: Therefore, it could be seen that the practical and continuous dual circuit task training was more effective than simple task training on gait. In comparison between the types of dual tasks, the dual motor circuit task training group showed more effects than the dual cognitive circuit task training group.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.9
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• pp.869-874
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• 2011

In a CNG/diesel dual-fuel engine, CNG is used as the main fuel and a small amount of diesel is injected into the cylinder to provide ignition priming. In this study, a remodeling of the existing diesel engine into a CNG/diesel dual-fuel engine is proposed. In this engine, diesel is injected at a high pressure by common rail direct injection (CRDI) and CNG is injected at the intake port for premixing. The CNG/diesel dual-fuel engine had an equally satisfactory coordinate torque and power as the conventional diesel engine. Moreover, the CNG alternation rate is over 89% throughout the operating range of the CNG/diesel dual-fuel engine. PM emission by the dual-fuel engine is 94% lower than that by the diesel engine; however, NOx emission by the dual-fuel engine is higher than that by the diesel engine.

• Journal of International Academy of Physical Therapy Research
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• v.6 no.1
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• pp.788-794
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• 2015

This study examines changes in walking ability among patients with stroke after applying dual-task training under the condition of visual control and unstable supporting ground; the purpose is to provide reference data for selecting intervention methods that enhance the walking ability of patients with stroke. Among the patients with stroke who received rehabilitation treatment(at Rehabilitation Hospital B in Gyeonggi, South Korea from May 2014 to July 2014), 29 patients were selected as research subjects; all of them understood the purpose and contents of this research and agreed to participate in the experiment. The research subjects were divided into a visual control and unstable supporting ground dual-task(VUDT) group(10 patients), a visual control dual-task(VDT) group(10 patients), and an unstable supporting ground dual-task(UDT) group(9 patients); all of the subjects received 30-minute trainings, three times a week for a total of four weeks. A Timed-Up-and-Go(TUG) test was performed to investigate the change of walking function among the subjects, and a 10m walking test was conducted to measure their walking speed. According to the study results, all three groups showed significant differences after dual-task training; the dual-task training group under the condition of visual control and unstable supporting ground showed the most prominent change. This study confirmed that dual-task training using visual control and unstable supporting ground has a positive impact on the walking ability of patients with stroke. Through the study results, we found that implementing dual-task training under the condition of visual control and unstable supporting ground can more effectively improve the walking ability of patients with stroke, rather than performing visual control dual-task training or unstable supporting ground dual-task training only.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.273-279
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• 2021

Metal material inserted into the body have a large difference in density from human tissues or bones around the Metal during CT scans.. Therefore, the Metal material inserted into the body produces Artifact. Metal Artifact, which occurs around Metals, can degrade the quality of CT images, causing confusion when medical team diagnose lesions. Through this experiment, we confirm that the occurrence of Artifacts decrease by using Dual energy CT and MAR algorithm in Single source Dual energy CT. We also want to present basic data on clinical application methods by comparing and analyzing the characteristics of images obtained by each method. Using GE 750HD CT, artificial implants were scanned using general method and Dual energy. Then we apply the MAR algorithm to each image obtained. And all previously acquired images were compared and analyzed the characteristics of the examination, such as image quality evaluation and dose evaluation. Images with MAR algorithm and Dual Energy confirmed a decrease in Metal Artifact. Images with MAR algorithm have reduced Metal Artifact, but have the disadvantage of distorting the details of artificial joint implants. On the other hand images teseted with Dual Energy have the advantage of being able to implement details than those applied with MAR algorithms, it takes longer to reconstruct the image and the exposure dose was about four times higher than those applied with MAR algorithm. In order to locate Metals, such as the post-operative follow-up period, it is useful to apply MAR algorithm to obtain images. And it is more useful to examine with Dual Energy when micro lesion identification, such as cardiac examination, and surgical planning or when tests are performed in diagnostic way.

• Physical Therapy Rehabilitation Science
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• v.1 no.1
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• pp.1-5
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• 2012

Objective: Dual-task walking deficits impact functional daily life, which often requires walking while performing simultaneous tasks such as talking, thinking or carrying an object. This study is to find out the latest trend of dual-task training's influence on ambulatory abilities of a stroke patient. Design: Systematic review of randomized controlled trials. Methods: This literature review was conducted in Pubmed and Sciencedirect with the follwing key words:stroke, cerebro-vascular accident, hemiplegia, gait, rehabilitation, exercise. 7 studies were chosen in findings by search tool. 3 studies were case study, 3 studies were cross sectional observational study and 1 study was randomized controlled trial. Results: It was found that stroke patients have difficulties in doing 2 motor tasks simultaneously and when they do 2 tasks, one is done in a naturally preferred activity areas. Moreover, when simply applying dual-tasks, the walking speed decreased. Meanwhile, when applying them through training, the speed increased. This showed the improvement of effective task-implementation abilities after dual-task training using task-integration models. Conclusions: In the beginning of the 2000s, dual-tasks were implemented by simply combining walking and cognition or exercise task, and the results of this study suggest that subjects with stroke have difficulty performing dual task. However, the latest trend is to let patients do the dual-task training by combining it with virtual reality. Therefore, dual task training could be performed in a safe in the environment such as virtual reality or augment reality.

• The Journal of Korean Physical Therapy
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• v.24 no.6
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• pp.405-408
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• 2012

Purpose: We examined the effect of dual-task and single-task training on serial reaction time (SRT) task performance to determine whether SRT is based more on motor or perception in a dual-task. Methods: Forty healthy adults were divided into two groups: the dual-task group (mean age, $21.8{\pm}1.6$ years) and the single-task group (mean age, $21.7{\pm}1.6$ years). SRT task was conducted total 480 trial. The four figures were presented randomly 16 times. A unit was set as 1 block that would repeat 10 times. Thus, there were a total of 160 trials for each of the three color conditions. The dual-task group performed an SRT task while detecting the color of a specific shape. The end of the task, subjects answered the specific shape number; the single-task group only performed the SRT task. The study consisted of three parts: pre-measurement, task performance, and post-measurement. Results: Differences of pre and post reaction time between two group was higher for the dual-task group as compared to the single task group and there was a significant interaction between time and group (p<0.05). Conclusion: Our results indicate that. short term period SRT is not quiet effective under dual-task conditions, individuals need additional cognitive processes to successfully navigate a task This suggests that dual-task training might not be appropriate for motor learning enhancement, at least when the training is over a short period.

• Journal of Biomedical Engineering Research
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• v.39 no.3
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• pp.134-139
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• 2018

One of the most common problems with pedicle screw system is pullout of the screw. This study was performed to evaluate the pullout strength and driving torque of newly designed pedicle screws. The design of three type screws were standard pedicle screw, which had single lead threaded and single pitched design (Type A), single pitched and dual lead threaded pedicle screw (Type B), dual pitched and dual lead threaded pedicle screw (Type C), respectively. The tests were performed in accordance with the ASTM standards using polyurethane (PU) foam blocks. There was no significant difference in pullout strength among three types of screw. Type B and Type C exhibited higher insertion torque and removal torque than Type A, respectively (p<0.05). Pedicle screws newly developed with dual pitched and dual lead threaded design showed higher driving torque without decrease in pullout strength compared to the standard pedicle screw and could be inserted more rapidly with the same number of revolutions.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.2
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• pp.69-76
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• 2000

A dual-modulus prescaler divides the input signal by one of the moduli according to the control signal. In this paper, a new fast dual-modulus prescaler is proposed. The proposed prescaler has a ratioed-NOR structure different from a conventional ratioed-NAND structure. The proposed one can operate at a higher speed by using parallely connected NMOSs instead of using series-connected ones. HSPICE simulation results using HYUNDAI 0.65(m 2-poly 2-metal CMOS process parameters show that the maximum operating frequency of the proposed dual-modulus prescaler is 2.8㎓ with power consumption of 40.7㎽ at 5V supply voltage at $25^{\circ}C$. The proposed dual-modulus prescaler can be utilized for the frequency-synthesis in cellular radio front-ends.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.278-283
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• 2004

Due to the complex arrangement of frequency plans and spatial overages in modern satellite communications, channels that are non-contiguous in frequency may be amplified by a single power amplifier and transmitted to the ground through one beam. In this paper, a dual-mode canonical filter with dual-passband is presented. The filter adopts dual-mode technique for mass and volume reduction. Canonical structure is adopted for maximum transmission zero realization. To validate the design technique, a 6-pole dual-mode canonical dual-passband filter for Ka-band(30/20 ㎓) satellite transponder is realized. The measured frequency response of the filter shows good agreement with the computed one.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.252-257
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• 2011

A compact microstrip dual-band bandpass filter with controllable bandwidth for each passband is proposed. Each passband is independently designed using two different dual-mode resonators. The proposed dual-band bandpass filter has three transmission zeros. Two transmission zeros are generated by each dual-mode resonator. An additional transmission zero is generated by input/output port coupling. The dual-band bandpass filter application is designed for 2.4/5.7 GHz WLAN. Experimental results are presented to validate theory.