• Journal of Navigation and Port Research
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• v.40 no.3
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• pp.159-164
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• 2016

The goal of this study is to implement a communication system that can monitor the status of the nacelle using the power cable itself, without the dedicated communication lines such as an UTP cable and optical fiber for the offshore wind turbine. An inductive coupling powerline communication system for a MW class offshore wind turbine was proposed and its communication performance was demonstrated. The inductive couplers was designed for operation at up to 500 A using a ferrite composite materials. Field test was carried out on the wind farms of Jeju island. Using the iperf communication test program, we have obtained more than 15 Mbps data transmission rate through the 100 m power cable that was installed between the nacelle and the bottom of the power converter. In the data transmission stability test for a week, there was no failure ever. The minimum transmission rate was 15 Mbps and the average data rate was about 20 Mbps. Next, we have installed an infrared camera inside the nacelle in order to measure the temperature distribution and variation of the nacelle. The real-time thermal image taken by the camera was successfully sent to the monitoring system without error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1824-1832
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• 2011

In this paper, a smart home service robot McBot II is newly developed in much more practical and intelligent system than McBot I which we had developed a few years ago. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot McBot II to completely overcome this problem on real environments. The mechanical design and the basic control of McBot II, which performs mess-cleanup function etc. in house, is actually focused in this paper. McBot II is mechanically modeled in the same method that the human works in door by using the waist and the hands. The big-ranged vertical lift and the shoulder joints to be able to forward move are mechanically designed for the operating function as the human's waist when the robot works. The mobility of McBot II is designed in the holonomic mobile robot for the collision avoidance of obstacle and the high speed navigation on the small area in door. Finally, good performance of McBot II, which has been optimally desinged, is confirmed through the experimental results for the control of the robotic body, mobility, arms and hands in this paper.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.157-166
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• 2019

Objective: This study examined the effects of stimulating fingertip temperature on the patterns of force sharing and stability properties during multi-finger force production tasks. Method: 9 adult subjects (male: 3, female: 6, age: $26.11{\pm}4.01yrs$, height: $169.22{\pm}5.97cm$, weight: $61.44{\pm}11.27kg$) participated in this study. The experiment consisted of three blocks: 1) maximal voluntary contraction (MVC) task, 2) single-finger ramp task to quantify enslaving (i.e., unintended force production by non-task fingers), and 3) 12 trials of multi-finger steady-state force production task at 20% MVC. There were three temperature conditions including body-temperature (i.e., control condition), $40^{\circ}C$, and $43^{\circ}C$, and the stimulation was given to the index finger only for all experimental conditions. Results: There were no significant differences in the MVC forces, enslaving, and the accuracy of performance during the steady-state task between the conditions. However, the share of stimulated index finger force increased with the index fingertip temperature, while the share of middle finger force decreased. Also, the coefficient of variation of both index and middle finger forces over repetitive trials increased with the index fingertip temperature. Under the framework of the uncontrolled manifold (UCM) hypothesis used to quantify indices of multi-finger synergies (i.e., stability property) stabilizing total force during the steady-state task, the two variance components within the UCM analysis increased together with the fingertip temperature, while no changes in the synergy indices between the conditions. Conclusion: The current results showed that fingertip temperature stimulation only to index finger does not affect to muscle force production capability of multi-finger, independence of individual fingers, and force production accuracy by the involvement of all four fingers. The effect of fingertip temperature on the sharing pattern and force variation may be due to diffuse reflex effects of the induced afferent activity on alpha-motoneuronal pools. However, the unchanged stability properties may be the reflection of the active error compensation strategies by non-stimulated finger actions.

• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.350-362
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• 2019

The purpose of this study was to examine the effects of job characteristics and health on accident experience by analyzing the data of transportation workers according to age. The analysis used data from 'the fourth Korean Working Conditions Survey(KWCS)'. A total of 1,997 transport workers data were finally analyzed, and correlation analysis, crossover analysis and logistic regression analysis were performed. It was confirmed that there was no correlation between the age of the transport workers and the accident experience. In the relationship between the characteristics of transportation workers and the experience of the accident, it was found that, in the case of older workers, there was a significant effect in the order of 'at mistake someone else hurt', 'musculoskeletal problem', 'cardiovascular problem' and 'repetitive movements of hands or arms', the model explaining power was 56.9%(p <.01). In the case of non-older workers, it was found that 'depression and anxiety disorder', 'relationship between job and safety', 'at mistake someone else hurt' and 'labor union', the model explaining power was 21.8%(p <.01). Therefore, in order to promote prevent accidents of transportation workers in future, it is necessary to consider various variables such as health and job characteristics besides age.

• 한국노년학
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• v.28 no.4
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• pp.1069-1087
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• 2008

The purpose of this study was to closely examine the effects of aromatherapy on Behavioral and Psychological Symptoms of Dementia(BPSD) to the elderly in a nursing home, and to help the application of aromatherapy is expected to be conducive to managing the quality life in the dementia and the care-giver, and to provide a base of the aromatherapy application as an elderly program in geriatric institutions. This is an one group pre-post test design and the research subjects were the dementia in a nursing home those were totally 15 available for communication or intention observation. Aromatherapy was offered for 3 weeks totally 15 times by once a day in each with aroma hand massage and inhalation, by blending essential oils, Lavender, Chamomile Roman and Grapefruit. The results are as follows. Given examining a change in the whole about whether there are effects of aromatherapy on BPSD, there was significant difference in a change depending on the experimental period with 1.47 for the pre-measurement value, 1.09 for the post 1-measurement value, 1.01 for the post 2-measurement value and 0.71 for the post 3-measurement value. And, even the difference in experimental period was indicated to have significant difference(F=11.501, p<0.001). As an itemized results, the effect of aromatherapy were indicated to have significant difference on easing the anxiety, anguish, fear, dreadful feeling, depressed feeling, and outstandingly bustling movement, and outstandingly inactive behavior, and sleep disturbance and behavior of wandering about at night. On the basis of the result in this study, the application of aromatherapy is expected to lead the quality life in the dementia, and to contribute to health of mind and body in the dementia as an program in geriatric institutions.

• Therapeutic Science for Rehabilitation
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• v.11 no.3
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• pp.37-50
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• 2022

Objective : This study aimed to investigate the use of electromyography (EMG) to evaluate upper limb movement or function in stroke patients. Methods : We reviewed papers published in journals between January 2018 and December 2021 using PubMed, EMBASE, Scopus, RISS, and KISS. The main keywords of databases were ('stroke' OR 'hemiplegia') AND ('EMG' OR 'electromyography' OR 'electromyogram' OR 'muscle activity') AND ('Upper limb' OR 'Hand'). Results : Fifteen studies were selected, most of which evaluated muscle activity. Interventions performing tasks related to activities of daily living (ADLs), using assistive technology, and interventions that provide repetitive training were most frequently applied. Conclusions : When evaluating upper limb functions using electromyography, it is meaningful to present an evaluation that can be used according to the purpose of the study and to provide a basis for setting up interventions that can utilize electromyography during evaluation.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.192-197
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• 2012

The competition between green manure and forage crops frequently occurred at agricultural field because of soil fertility and livestock feeding selection. These experiments were carried out to evaluate the effects shoot and residue for green manure and forage production by leguminous crops and barley mixtures at paddy. Field experiments were conducted at paddy soil from 2008 to 2009. Treatments consisted of mixture and inter-seeding of barley and leguminous crops (hairy vetch and crimson clover). These treatments were divided into cutting height of 8 and 25 cm for using of green manure and forage at once. The residue biomass of 25 cm cutting height was higher than 8 cm and were no significantly between mixture and inter-seeding. However, residues of legume crop were significantly higher at inter-seeding than mixture. The shoot biomass of 8 cm cutting height was higher than 25 cm for forage using. The production of legume crop was high at the barley and hairy vetch seeding plot. The mixture of hairy vetch and barley showed the best biomass of shoot and residue for green manure and forage using at 25 cm of cutting height. Also this treatment could be possible to rice cultivation by no fertilization. Therefore, we suggested that 25 cm cutting of hairy vetch and barley mixture could be used for green manure and forage at the same time under rice-based cropping system.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.51-63
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• 2002

This study sought to identify the kinematic characteristics at entrance to the straight course from the curvilinear course in the 200m-track game. For this purpose, this study was conducted for 4 sprinters by setting the 10m-section combined from the curvilenear track to the straight course and shooting them with the camcorder. It was set up to include all the sections of analysis by using the framework of the control point knowing the coordinate of the space and actual analysis was conducted on the motion showing the best records by conducting it for each subject five times. As a result, the following conclusion was drawn: It was found that the subjects showed the average stride of 4.5${\pm}$0.41 times at the 10-meter section and the required time of 1.42${\pm}$0.04sec. They showed the ratio average stride to height of 1.25${\pm}$0.20% and the average speed of 7.06${\pm}$0.19m/s. The displacement in the center of gravity of the human body at the section combined from the curvilinear course to the straight course was moving along the inward course of the curvilinear course, and the displacement of the leg located at the outward direction(right) was found to be larger than that of the leg located at the inward direction(left). In the speed of the left and right hand segments, it was found that the speed of the right hand located in the outward direction was faster than that of the left hand located at the inward, and it was found that the subjects progressed in the curvilinear course. The subjects showed the larger angle of the shoulder joint when the upper arm was located in the forward direction than when the it was located in the backward direction. In the curvilinear course, they showed the lower value of the lateral angle of the trunk when the right foot located at the outward direction left the ground than when the left foot located at the inward direction left the ground. And it was found that the lateral angle of the trunk became lower with approaching the straight course.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.5 s.108
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• pp.461-475
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• 2006

In this paper, it is described about the tri-band mobile antenna system design to provide broadband multimedia and direct broadcasting services using goo-stationary Koreasat 3, simultaneously operated in Ka/K/Ku band. The radiating part of the antenna system with a fan beam characteristic in the elevation plane is composed of the quasi-offset dual shaped reflector and the tri-band feeder. The tri-band feeder is also composed of the Ka/K dual band feeder with the protruding dielectric rod, the circular polarizer, the ortho-mode transducer and the circular-polarized Ku band feed array. Especially, the Ka/K dual band circular polarizer was realized firstly using the comb-type structure. For fast satellite-tracking on the movement, the Ku band feed array has the structure of the $2{\times}2$ active phased array which can make electrical beams. And, the circular-polarized characteristic in the feed array was improved by $90^{\circ}$ rotating arrangement of four radiating elements polarized circularly by a $90^{\circ}$ hybrid coupler, respectively. Four beam forming channels to make electrical beams at Ku band are divided into the main beam channel and the tracking beam channel in the output, and noise temperature characteristics of each channel were analyzed on the basis of the contributions of internal sub_units. From the fabricated antenna system, the output power at $P_{1dBc}$ of Ka_Tx channel was measured more than 34.1 dBm and the measured noise figures of K/Ku_Rx channels were less than 2.4 dB and 1.5 dB, respectively, over the operating band. The radiation patterns with co- and cross-polarization in the tri-band were measured using a near-field measurement in the anechoic chamber. Especially, Ku radiation patterns were measured after correcting each initial phase of active channels with partial radiation patterns obtained from the independent excitation of each channel. The antenna gains measured in Ka/K/Ku band of the antenna system were more than 39.6 dBi, 37.5 dBi, 29.6 dBi, respectively. And, the antenna system showed good system performances such as Ka_Tx EIRP more than 43.7 dBW and K/Ku_Rx G/T more than 13.2 dB/K and 7.12 dB/K, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.336-344
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• 2017

This study was conducted to identify factors related to the musculoskeletal symptoms of 340 family caregivers who have a patient with brain damage based on self-administered questionnaires. The questionnaires included general characteristics, characteristics of care activities and caregivers' musculoskeletal symptoms. Data were collected from many long-term care hospitals and rehabilitation centers during March 17 to March 21, 2014. The results indicated that complaint rates of work-related musculoskeletal systems of the body sites differed. Factor analysis revealed that neck complaints were related to education (under mid), while shoulder complaints were related to sex (female), age (50-59), education (mid) and duration of care (< 2 years). Arm/elbow complaints were related to age (40-49), education (high) and duration of care (12-24). Complaints regarding the hand/wrist/finger were related to age (50-59) and duration of care (12-24), while those associated with the legs/feet were related to age (50-59) and duration of care (< 6[ED highlight - years? Please specify.]). Back problems were related to education (under mid, mid stage, high) and gait. The complaint rate regarding musculoskeletal symptoms during daily life was not statistically significant. Logistic regression analysis of significant factors related to subjective musculoskeletal symptoms identified ambulation and gait as having the greatest influence and complaint factor among family caregivers. The complaint rate of family caregivers differed among body parts. Being a caregiver for less than one year was found to have a significant impact on pain. Overall, long term family caregivers could be faced with risk factors for musculoskeletal problems, but there are many different factors that affect musculoskeletal symptoms with regards to their activities. Accordingly, comprehensive and systematic prevention plans for family caregivers who have patients with brain damage should be developed.