• Safety and Health at Work
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• v.5 no.3
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• pp.140-146
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• 2014

Background: Young male and female workers are over-represented in statistics concerning negative outcomes of poor work environment and risky work. Young workers often have low awareness of risk, a lack of safety training, and inadequate introduction to the work. The aim of this study was to identify the knowledge and experiences of pupils of vocational schools concerning potential work environment risks in their future work. Methods: The study design was a dual one, and included a questionnaire and focus group interviews. The study group consisted of 239 pupils from 10 upper secondary schools, who were graduating pupils in four vocational programs: the Industrial Technology Programme, the Restaurant Management and Food Programme, the Transport Programme, and the Handicraft Programme (in which students specialize in wood products). The upper secondary schools were located in the central region of Sweden. Results: The pupils had limited knowledge that employers must, by law, conduct risk analyses and prevent risks. Many felt that they themselves are mainly responsible for performing their tasks safely. Pupils in all programs mentioned acute risk as the greatest risk at work. The theoretical education about safety at work was provided in the $1^{st}$ year of the 3-year vocational programs. Conclusion: A systematic approach to pupils' training in work environment, which is a basis for a safe and healthy workplace, is lacking. The study findings indicate that pupils are offered knowledge far from that intended by laws and by state-of-the-art occupational health risk research.

• Journal of Korean Medicine for Obesity Research
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• v.4 no.1
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• pp.23-31
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• 2004

Background: Obesity is associated with menstrual disorder. Especially, upper-body obesity affects on female reproductive function. Objectives: The goals were to investigate relation between fat distribution and menstrual disorder in obese pre-menopausal Korean females. The hypothesis were tested that there is a relation between upper body obesity and menstrual disorder. Design: A cross-sectional evaluation of 66 Females (baseline age $32.15{\pm}7,32)$ with body mass index $31.22{\pm}4.05\;kg/m^2$. Body composition was measured using bioimpedence analysis (BIA) and anthropometry was done by same observer. VAS and Multidimensional verval rating scale(MVRS) were checked for menstrual pain. Dual-Energy X-ray Absorptiometry (DXA) was measured for evaluating body fat distribution. Menstrual disorder and body fat distribution were compared using statistical methods. Results: TLFR and WH ratio was higher in menstrual cyclic disorder group than controls. There was negative relationship between VAS and TLFR. Conclusions: The data shows that disorder of menstrual cycle was associated with upper body obesity. WH ratio could be one of the factor of menstrual disorder. VAS was correlated with lower body obesity. Further studies for role of upper body fat distribution on female reproductive function and relationship between menstrual pain and fat distribution thought to be needed.

• Journal of Drive and Control
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• v.15 no.3
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• pp.14-20
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• 2018

Wet clutches in an automatic transmission enable the transmission of the engine power by the frictional torque experienced and noted between disk and plates. Since the clutch frictional torque considerably affects the shift quality of an automatic transmission as well as the durability of the machinery, its friction characteristics must be carefully examined to meet the design requirements. The SAE No. 2 friction test machine is a well-known standard to evaluate mainly the friction characteristics of plate clutches along with the required automatic transmission fluids. This paper reviews the experimental analysis of the wet clutch friction characteristics by using the exclusively developed clutch test machine which is capable of controlling the clutch test procedure, in accordance with the applicable test standard and processing of the experimental data automatically. As the clutch test machine is designed for the accommodation of dual clutches which is applied to the real transmission, it can evaluate not only the clutch friction characteristics, but also an actuation performance of a measured clutch piston. In respect to friction characteristics involving dynamic friction coefficients, the energy absorbed in a clutch disk and the recorded temperatures of clutch plates during braking actions and procedures are also investigated. Additionally, the change of friction coefficients by the use of the repeated clutch application is also observed with the endurance test functions of an accurately calibrated and dedicated clutch test machine.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.28.4-29
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• 2009

The 'Amon-Ra' instrument of the proposed 'EARTHSHINE' satellite is a dual (i.e. imaging and energy) channel instrument for monitoring the total solar irradiance (TSI) and the Earth's irradiance at around the L1 halo orbit. Earlier studies for this instrument include, but not limited to, design and construction of breadboard Amon-Ra imaging channel, stray light suppression and system performance computation using Integrated Ray Tracing (IRT) technique. The Amon-Ra instrument is required to produce 0.3% in uncertainty for both Sunlight and Earthlight measurement. In this study, we report accurate estimation of the output electric signal derived from the orbital variation of radiant exitance from the Sun and the Earth arriving at the aperture and detector plane of the Amon-Ra. For this, orbital irradiance are computed analytically first and then confirmed by simulation using Integrated Ray Tracing (IRT) model. Specially, the results show the arriving power at the bolometer detector surface is $1.24{\mu}W$ for the Sunlight and $1.28{\mu}W$ for the Earthlight, producing the output signal pulses of 34.31 mV and 35.47 mV respectively. These results demonstrate successfully that the arriving radiative power is well within the bolometer detector dynamic range and, therefore, the proposed detector can be used for the in-orbit measurement sequence. We discuss the computational details and implications as well as the simulation results.

• Physical Therapy Rehabilitation Science
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• v.4 no.1
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• pp.32-37
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• 2015

Objective: This study was conducted to test the effects of mobile texting and gaming on gait with obstructions under different illumination levels. Design: Cross-sectional study. Methods: Twelve healthy adults aged 20 to 36 years (mean 23.5 years) were tested under six different conditions. All participants used touchscreen smartphones. Testing conditions included: 1) Walking with an obstruction under a bright illumination level; 2) walking with an obstruction with a low level of illumination; 3) walking with an obstruction while texting under a bright illumination level; 4) walking with an obstruction while texting with a low level of illumination; 5) walking with an obstruction while gaming under a bright illumination level; and 6) walking with an obstruction while gaming with a low level of illumination. All participants were asked to text the Korean national anthem by their own phone and play Temple Run 2 using an iPhone 5. Gait variances were measured over a distance of 3 m, and the mean value after three trials was used. A gait analyzer was used to measure the data. Results: Compared to normal gait with obstruction, gait speed, step length, stride length, step time, stride time, cadence while texting and gaming showed significant differences (p<0.05). Differences between the illumination levels included gait speed, step length, stride length, and step time (p<0.05) with no significant differences in stride time and cadence. Conclusions: Dual-tasking using a smartphone under low levels of illumination lowers the quality of gait with obstructions.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.495-501
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• 2016

The film has always reflected the culture of the era based on reality and imagination. The visual effect in the film has mainly played a role of expressing the reality more realistically or recognizing the virtual as reality. This study examines the meaning and the effect of fantasy realism through Oasis of Lee Chang-dong. Fantastic realism has separated the reality from the imaginary space by using a dual meaning tool that affects the time and space in the film and reflects the human desire and desire to see. It was also reproduced in the real world through the medium of pigeons. In addition, it separates visualized space from non-visualized space in film narrative structure, separation of real and unreal space, segregation of consciousness and unconscious space, and separation of reality and reality space into power structure. With the development of technology, the image of the yellow image comes closer to us like reality, which will express the space of unconsciousness that we could not think of.

• Journal of Digital Convergence
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• v.18 no.9
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• pp.9-15
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• 2020

This study is to analyze the influence of the digital divide on the digital daily life of the elderly. Adaptation tendencies for digital divide were measured and classified into groups for elderly people over 60 years old. And digital communication skills, digital confidence, digital self-control, and digital life satisfaction were measured. The research model used a cross over design model and a dual mediation model. As a result of the study, first, it was found that a group with high adaptive accessibility to the digital divide had a positive effect on the overall digital daily life. Second, a group with high adaptive literacy to the digital divide had a positive effect on the digital self-control. Third, digital communication skill has a positive effect on digital life satisfaction, and digital confidence and digital self-control play a mediating role. Based on these findings, we discussed strategies to overcome the digital divide in old age.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.1
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• pp.17-26
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• 2005

Both numerical analysis and cold tests for the swirl coaxial type injector were performed to obtain the influence of spray angle, velocity ratio and liquid film thickness for pressure drop and recess. The basic experimental and numerical data obtained in this study can be applicable to the performance design of swirl coaxial type injector. Spray angle was not affected by the applied test pressure drop, but spray angle was affected by tangential velocity ratio and shape factors. Feasibility of numerical analysis for the liquid film thickness and spray angle was confirmed, and the change of liquid film thickness by tangential velocity ratio affected more seriously than pressure drop, and liquid film thickness was decreased with increasing tangential velocity ratio.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.6
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• pp.59-67
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• 2014

Acceptance level random vibration and life firing test for development model of 1 N-class monopropellant thruster have been performed. From the results of random vibration, the natural frequency of the dual thurst module composed of 1 N-class development model thrusters was higher than the part level requirement(>100 Hz) and the structural robustness was verified. Thrust decrease of steady sate was below 7% and thrust instability was within ${\pm}5%$ in the life firing test using over 20 kg propellant throughput. The computerized tomography for catalyst bed showed a less than 7% of catalyst loss and it revealed the design appropriateness of the current thruster development model.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.189-197
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• 2008

ENS-2 simulator is the most widely-used simulator in the research of wired/wireless communication. Since an IEEE 802.11 module has been implemented in NS-2. much research using this module has been done for various MAC layer functions. The most important problem in terms of performance is the hidden terminal problem. To solve this problem, the solutions using a busy-tone such as BTMA, DBTMA, etc. have been proposed. In order to be able to use a busy-tone, channels using the frequency bandwidth except the frequency bandwidth of the data channel is required for the collision prevention, and a MAC layer has to be able to menage such multiple channels. In this research, we implement a module that can use a busy-tone in NS-2, implement a modified RI-BTMA by applying the implemented module, and verify its performance.