• Journal of Distribution Science
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• v.20 no.11
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• pp.99-108
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• 2022

Purpose: The wide distribution of smartphones has changed life and user behavior. This phenomenon has both advantages and disadvantages for users. As smartphones become a part of our daily lives, smartphone addiction has recently become a social issue in many countries. This study explores factors that affect smartphone addiction and the consequences of addictive behaviors. Research design, data and methodology: Our model hypothesizes that four key factors determine addictive behavior: flow, enjoyment, preference for online social life, and escape reality. Commitment and compulsive use are mediating variables that connect key drivers and addictive results. Based on the SEM (structural equation model) analysis of 497 survey responses, these four driving factors each have a significant effect on the compulsive use of smartphones directly or indirectly; the compulsive use of smartphones directly influences the three results Results: We conducted a reliability and validity analysis, and the results were successful. In the hypothesis test, every path is accepted as expected at the significance level of 0.05. Conclusions: Among the four driving factors, escape reality is the vital factor influencing smartphone addiction and its consequences. And anxiety is the number one consequence influenced by the compulsive use of smartphones.

• Korean Journal of Occupational Health Nursing
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• v.29 no.4
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• pp.288-294
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• 2020

Purpose: This study aimed to comprehensively examine middle-aged male taxi drivers' perceptions of the risk of cardiovascular disease. Methods: A qualitative method was used, with focus group interviews. The participants were middle-aged male taxi drivers who had been driving for more than ten years and for more than six hours daily. Results: The data were analyzed using qualitative thematic analysis. Middle-aged male taxi drivers' perceptions of the risk of cardiovascular disease were categorized into three main themes: "individual perceptions of cardiovascular disease", "possibility of behaviors for cardiovascular disease" and "motivations of behaviors for cardiovascular disease". Six sub-themes were extracted as follows: "perception of vulnerability", "perception of seriousness", "perception of profitability", "perception of disability", "self-awareness" and "advancing toward health care". Conclusion: It is necessary to invigorate support systems through measures including education, counseling, and web-based programs to prevent cardiovascular disease in middle-aged male taxi drivers.

• Asian Journal for Public Opinion Research
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• v.5 no.3
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• pp.192-203
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• 2018

Alcohol consumption among soldiers impairs health status, performance, and increases the risks of injuries and violence. This study examined drinking behaviors, health problems, and violence among enlisted soldiers at Adisorn military unit in Saraburi, Thailand. Data collection using self-reported questionnaires were distributed to 256 enlisted male soldiers in May 2017. Participants were age 20-22 (93%), Buddhists (98%), high school education or lower (93%). They purchased alcohol at their own expense (46.5%). For alcohol consumption, all were lifetime drinkers (100%). The current drinking patterns were different 28.5% were current drinkers, 65.5% are currently abstaining from drinking (64.5%), and 6.6% stopped drinking permanently. The top three alcohol beverages were beer (52.3%), brandy (25.0%), and hard liquor (19.5%). Problems related to alcohol were from lost balance/falls (6.7%), illness (10.2%), driving under the influence (19.5%), and accidents (24.2%). Violence from drinking in the past month was from fighting (28.1%). This study is the first to provide information about alcohol-related problems in enlisted male soldiers. There is the need to offer straightforward advice, brief counseling, and refer soldiers to receive treatment to prevent alcohol-related problems. Online social media and web-based programs were recommended as platforms to provide preventive alcohol message to the enlisted.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.3
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• pp.279-286
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• 1995

As Al-Li based alloys are to find widespread use in aerospace and other structural applications in which their low-density high specific stiffness properties be exploited, their mechanical properties must adequately match those of the which they intended to replace. In order to develop these purposed, the precipitation behaviors of the rapidly solidified Al-Li-Ti alloys aged at various temperature were investigated. ${\delta}'$ phase precipitated homogeneously in the matrix during not only melt quenching but also aging at the aging temperature of $160^{\circ}C\;and\;210^{\circ}C$. The addition of the Ti in Al-Li alloy promoted the formation of $\delta$' phase. The addition of Ti on the ${\delta}'$ solvus line had a little effect over the thermodynamics ${\delta}'$ solvus line. The reason for these behavior was that the ${\delta}'$ phase was suppressed to precipitate as much as supercooling by melt quenching. The discontinuous precipitation reaction occurred by the preferential growth of ${\delta}'$ phase due to the migration of grain boundary provided the driving force dependent of solute concentration fluctuations.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.2
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• pp.161-168
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• 2015

An experimental study was conducted to scrutinize the influence of the frequency of an ultrasonic standing wave on the variation in the behavior of a methane-air premixed flame. The evolutionary features of the propagating flame were captured by a high-speed camera, and the macroscopic flame behavior, including the flame structure and local velocities, was investigated in detail using a post-processing analysis of the high-speed images. It was found that a structural variation and propagation-velocity augmentation of the methane-air premixed flame were caused by the intervention of the ultrasonic standing wave, which enhanced the combustion reaction. Conclusive evidence for the dependency of the flame behaviors on the driving frequency of the ultrasonic standing wave and equivalence ratio of the reactants is presented.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.731-736
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• 2011

A pneumatic driving solenoid valve operates pneumatic control devices by opening/closing operating flow passage when the command is given by control system for the liquid-propellant feeding system of space launch vehicle. The simulation model of pneumatic driving solenoid valve is designed with AMESim to verify the designs and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of their operating durations of valve by AMESim analysis are compared with the results of experiments. In addition, the results of internal flow simulation with FLUENT are utilized to improve the accuracy of valve-modeling. Using the model, we analyze performance of valve; opening/closing pressure, operating time on various design factors; shape of control valve seat, drainage seat, rate of sealing diameter, volume of control cavity. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditions, which shall be used in Korea Space Launch Vehicle-II.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1555-1558
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• 2008

Various approaches were undertaken by major PDP makers in order to improve the luminous efficacy of the plasma discharge cells. There have been many reports that state that using a high Xe content PDP is one of the most promising key technologies available to improve the luminous efficacy. In the case of the higher Xe content panel, the higher address and sustain voltage were needed to drive the panel under the same reset condition. In this study, a variety of Xe content panels were investigated in order to examine wall voltage transfer behaviors. The transferred wall voltage status after addressing discharge at the same driving condition was analyzed by comparing Vt close curve of high and low Xe content panels. Through this analysis of Vt close curve difference, the driving waveform of a high Xe panel was quantitatively adjusted Under the same address voltage condition, results showed that the amount of the transferred wall voltage and Vt close curve after addressing discharge was matched for the first sustain discharge. Taking these results into consideration, we conclude that the driving waveform for different Xe content panels could be designed for the desired addressing discharge condition and the wall voltage state of the cell could be quantitatively controlled and measured through these approaches.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.112-123
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• 2012

Different from general roads, intersections are the points where roads having different geometric structure and traffic operation system are met, and thereby they have complicated road structure and environmental factors. Various changes in driving patterns such as collision between vehicles approaching from roads adjacent to intersections, sudden stop of vehicles upon stop sign, quick start upon green lights kept increasing traffic accidents. It is known that traffic accidents are mainly derived from human factors. This study, in order to find out factors affecting drivers' behaviors within intersections, measured physiological responses such as brain wave, sight, driving speed, and so on by using state-of-the-art measuring device. As to concentration brain wave at individual intersections, it was found out that brain wave of testes was higher at main Arterial and accident-prone intersections compared with that of subsidiary Arterial. In addition, it was detected that drivers' visual activity was widely distributed at accident-prone intersections, meaning that it enhanced cautious driving from nearby vehicles. As to major factors causing drivers' workloads, factors from nearby vehicles such as deceleration, acceleration, lane change of nearby vehicles appeared as direct factors causing drivers' workloads, clarifying that these factors were closely related to causes of traffic accidents at intersections. Results of this study are expected to be used as basic data for evaluation of safety at intersections in consideration of physiological response of drivers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6C
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• pp.251-258
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• 2011

Steel pipe piles have been used as various deep foundation materials for a long time. Recent increase in steel material cost has made engineers reluctant in using it even with its good quality and ease of construction. Therefore when constructing with steel pipe pile, the decision to reuse the excessive pile length that is cut off from the designed pile head elevation after pile driving can be cost saving. This has caused many constructors to reuse the pile leftovers with new piles, but the absence of quantitative structural capacity behaviors of steel pipe pile after pile driving or appropriate countermeasures and standards in reusing steel pipe pile has resulted in wrong applications, pile structural integrity problems, inappropriate limitation of reusable pile length, etc. The structural performance analysis between a new pile and a pile that has undergone working state and ultimate state stress level during pile driving was performed in this research by means of comparing the results between the dynamic pile load test, tensile load test, charpy energy test and fatigue test for high strength steel of $440N/mm^2$ yield strength. Test results show that under working load conditions the yield strength variation is less than 2% and for ultimate load conditions the variation is less than 5% for maximum total blow count of 3000. The results have been statistically analyzed to check the sensitivity of each factors involved. From the test results, reusability of steel pipe pile lies not in the main pipe yield strength deviation but in the reduction of absorb energy, strength changes and quality control at the welded section, shape deformation and local buckling during pile driving.

• Journal of the Korean Society of Costume
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• v.62 no.1
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• pp.1-13
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• 2012

This study is aimed at finding out the self-perception and value of clothing they wear to today's businessmen who work in a fast-growing global network society and for developing a suitable image consulting program for businessmen. The purpose of this study is to categorize businessmen into personality types, and then analyzing purchase behaviors for clothing and image perception, self-image satisfaction among categorized groups. The participants of this study are 320 businessmen who are from 20's to 50's and working in Seoul. A total of 302 questionnaires were used for the survey of this study. The questionnaire is composed of 3 different parts as follows: 1) personality types, 2) purchase behaviors for clothing and image perception, 3) self-image satisfaction. The methods of this study are frequency analysis, descriptive analysis, factor analysis, variance analysis, cluster analysis, t-test and reliability analysis. In conclusion, an image consulting education program for businessmen has to be based on one's own personality type, current fashion style and image perception. Each person has to be provided a unique direction to increase his self satisfaction, which will result in improvements in both personal image satisfaction and social satisfaction. These changes will ultimately become the driving force of career life.