• Information Systems Review
• /
• v.17 no.2
• /
• pp.77-100
• /
• 2015

This study examined the factors that influence the smartphone user's decision to accept the personalized mobile advertisement. As a theoretical basis, we applied the privacy calculus model (PCM) that illustrates how consumers are engaged in a dynamic adjustment process in which privacy risks are weighted against benefits of information disclosure. In particular, we investigated how smartphone users make a risk-benefit assessment under which personalized service as benefit-side factor and information privacy risks as a risk-side factor accompanying their acceptance of advertisements. Further, we extend the current PCM by considering advertisement fatigue as a new factor that may influence the user's acceptance. The research model with five (5) hypotheses was tested using data gathered from 215 respondents through a quasi-experimental survey method. During the survey, each participant was asked to navigate the website where the experimental simulation of a mobile advertisement service was provided. The results showed that three (3) out of five (5) hypotheses were supported. First, we found that the intention to accept advertisements is positively and significantly influenced by the perceived value of personalization. Second, perceived advertisement fatigue was also found to be a strong predictor of the intention to accept advertisements. However, we did not find any evidence of direct influence of privacy risks. Finally, we found that the significant moderating effect between the perceived value of personalization and advertisement fatigue. This suggests that the firms should provide effective tailored advertisement that can increase the perceived value of personalization to mitigate the negative impacts of advertisement fatigue.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.5
• /
• pp.47-53
• /
• 2020

The purpose of this study was to increase product reliability by improving the durability of the breech block for a 30mm Automatic Gun. The breech block is a key component of a gun that functions as chambering, closing, and extracting. The breech block requires high reliability, which needs to be improved because cracks of a breech block can occur early in operation. Cause analysis confirmed that the crack is caused by repeated impacts. Therefore, the following improvement measures were studied, and the effects were demonstrated using a firing test. The energy of impact absorption was increased by changing the material, and the stress concentration was mitigated by increasing the value of R. In addition, the fatigue life was increased by adding Shot-peening, deleting chromium plating, and changing the forging method. The firing test did not show firing trouble for up to 5,000 rounds. The start timing of the crack was delayed, and the depth was small. Therefore, the improved product was more durable than the existing product. This study can be used as a useful reference when assessing the improvement of the durability of similar products, life study, and criteria for crack acceptance.

• Journal of Technologic Dentistry
• /
• v.32 no.2
• /
• pp.65-74
• /
• 2010

Purpose : To understand the impact on the strength or restoration force by the change of heating temperature when soldering 18-8 stainless steel round wire which is the chrome-nickel class for dental orthodontic device production. Methods : The following conclusions were made upon the results from tensile strength test, 3 point bending test, and $90^{\circ}$ bending fatigue test with 24 samples that had been applied with condition 1 (before heat treatment - natural) and condition 2 (after heat treatment - mooring 30 seconds after heating up to $500^{\circ}C$, $700^{\circ}C$, and $900^{\circ}C$) to ${\phi}0.4mm$, ${\phi}0.7{\beta}mm$, 18-8 stainless steel round wire (spring hard) by Jinsung Company. Results : When it was heat-treated at $900^{\circ}C$, both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low tensile strengths compared to the heat treated cases at $500^{\circ}C$ and $700^{\circ}C$ Yield strengths of both ${\phi}0.4mm$ and ${\phi}0.7mm$ showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$, as well. Upon the results of 3 point bending test, the heat treated case at $900^{\circ}C$ showed very low in both ${\phi}0.4mm$ and ${\phi}0.7mm$, compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Tensile strength of both ${\phi}0.4mm$ and ${\phi}0.7mm$ as well, showed very low compared to the heat treated cases at natural, $500^{\circ}C$, and $700^{\circ}C$. Upon the results of $90^{\circ}$ bending fatigue test, the heat treated case at $900^{\circ}C$ showed the highest wave node resistance in both ${\phi}0.4mm$ and ${\phi}0.7mm$. Conclusion : This study concluded that heating temperature change during wire soldering impacts on the characteristics of orthodntic wire.

• Ocean Systems Engineering
• /
• v.2 no.2
• /
• pp.99-113
• /
• 2012

Steel Catenary Risers (SCR) are the simplest and often the most economic solution compared to other riser types such as flexible pipe, riser towers, top tensioned risers, etc. The top of a SCR is connected to the host platform riser porch. The other end of the SCR connects to flowlines from subsea wells. The riser touchdown point (TDP), which is the location along the riser where contact with the sea floor first occurs, exhibits complex behaviors and often results in compression and fatigue related issues. Heave dynamic responses of semisubmersibles in extreme and operating sea states are crucial for feasibility of SCR application. Recent full field measurement results of a deep draft semisubmersible in Hurricane Gustav displayed the considerable discrepancies in heave responses characteristics between the measured and the simulated results. The adequacy and accuracy of the simulated results from recognized commercial software should be examined. This finding raised the awareness of shortcomings of current commercial software and potential risk in mega investment loss and environmental pollutions due to SCR failures. One main objective of this paper is to attempt to assess the importance and necessity of accounting for viscous effects during design and analysis by employing indicator of viscous parameter. Since viscous effects increase with nearly third power of significant wave height, thus newly increased metocean criteria per API in central Gulf of Mexico (GoM) and even more severe environmental conditions in Western Australia (WA) call for fundamental enhancements of the existing analysis tools to ensure reliable and robust design. Furthermore, another aim of this paper is to address the impacts of metocean criteria and design philosophy on semisubmersible hull sizing in WA and GoM.

• Physical Therapy Rehabilitation Science
• /
• v.5 no.4
• /
• pp.178-184
• /
• 2016

Objective: Tension-type headache is caused by hormones, foods, irritants, stress, obesity, fatigue, and neck and head trigger points-prolonged abnormal posture. The purpose of this study was to evaluate the effects of relaxation approach on head posture, static postural stability, and headache in persons with tension-type headache. Design: Randomized controlled trial. Methods: Thirty-five persons with tension-type headache participated in this study. This study was a pretest-posttest with a control group design for a duration of 4 weeks (60 min/3 times/1 wk). The participants were randomly allocated to the relaxation approach group (n=18) and the control group with conventional rehabilitation including thermotherapy and transcutaneous electrical stimulation for the same period (n=17). Outcome measures involved forward head posture (FHP), foot pressure, neck disability index (NDI), and six-item headache impact test (HIT-6). Results: Relaxation approach and control groups improved significantly in the amount of forward head posture, neck disability index, and six-item headache impact test scores after training (p<0.05). The control group was found to be significantly different in the amount of FHP, backward foot pressure, NDI, and HIT-6 after training compared to before training (p<0.05). The relaxation approach group significantly improved in forward head posture, neck disability index, and six-item headache impact test compared with control group after training (p<0.05). Neck disability index and six-item headache impact test significantly improved after training compared with before training in the control group (p<0.05). However, the foot pressure was not significantly different between relaxation approach and control groups. Conclusions: This study suggests that treatment with relaxation approach combined with self-exercise would be effective in reducing the amount of forward head posture, neck disability and headache impacts.

• Journal of Home Health Care Nursing
• /
• v.27 no.1
• /
• pp.29-41
• /
• 2020

Purpose: This study aimed to investigate the influence of post-traumatic stress on professional quality of life as mediated by cognitive emotion regulation among nurses working in small and medium hospitals who have experienced violence and to develop and test a structural equation model of that professional quality of life. Methods: Participants were 215 nurses who had experienced violence working in medium and small hospitals. They were surveyed using a structured questionnaire. Results: The final model was shown to have good fit with χ² (2.83), GFI (.90), TLI (.90), and CIF (.90). Therefore, the model was selected as the final model, supporting 7 of the 11 hypotheses. Post-traumatic stress, adaptive emotional regulation, and maladaptive emotional regulation had significant impacts on empathy satisfaction (professional quality of life subscale) and empathy fatigue (subscale of professional life quality) among nurses who had experienced violence, and the explanatory power of these variables was 28.7% and 38.6%, respectively. Conclusion: In the development of nursing intervention programs to improve the professional quality of life of nurses who have experienced violence, factors such as post-traumatic stress and cognitive emotion regulation (adaptive and maladaptive) should be considered as they were identified in this study as influencing the professional quality of life of such nurses in medium and small hospitals.

• Structural Engineering and Mechanics
• /
• v.63 no.1
• /
• pp.1-9
• /
• 2017

Shot peening is a cold surface treatment employed to induce residual stress field in a metallic component beneficial for increasing its fatigue strength. The experimental investigation of parameters involved in shot peening process is very complex as well as costly. The most attractive alternative is the explicit dynamics finite element (FE) analysis capable of determining the shot peening process parameters subject to the selection of a proper material's constitutive model and numerical technique. In this study, Ansys / LS-Dyna software was used to simulate the impact of steel shots of various sizes on an aluminium alloy plate described with strain rate dependent elasto-plastic material model. The impacts were carried out at various incident velocities. The influence of shot velocity and size on the plastic deformation, compressive residual stress and force-time response were investigated. The results exhibited that increasing the shot velocity and size resulted in an increase in plastic deformation of the aluminium target. However, a little effect of the shot velocity and size was observed on the magnitude of target's subsurface compressive residual stress. The obtained results were close to the published ones, and the numerical models demonstrated the capability of the method to capture the pattern of residual stress and plastic deformation observed experimentally in aluminium alloys. The study can be quite helpful in determining and selecting the optimal shot peening parameters to achieve specific level of plastic deformation and compressive residual stress in the aluminium alloy parts especially compressor blades.

• Journal of the Korean Society for Railway
• /
• v.16 no.1
• /
• pp.26-31
• /
• 2013

The reduction unit is one of the most important components for railway vehicles because the torque of the motor must be transmitted to the wheels of the vehicle by the reduction unit. The faults in the reduction units of high-speed trains are caused by damage such as gear, fatigue. These have serious impacts on safety of the train during operation. To address this development of a system for monitoring, fault diagnosis of the reduction unit is needed to keep the vehicle running safely. Before that can be accomplished, it is most important to understand the vibration characteristics of the reduction unit in a normal state. Vibration diagnosis technology using characteristic-analysis of vibration waveform and frequency is known to be the most effective method for fault diagnosis. In this paper, we analyzed the vibration characteristics of the reduction units two Korean high-speed trains (KTX and KTX II), under normal conditions, by two test methods (driving gear test, full-vehicle test).

• The Korean Journal of Food And Nutrition
• /
• v.29 no.6
• /
• pp.899-910
• /
• 2016

The purpose of this study was to determine factors related to the consumption of energy drinks among male and female high school students in Daejeon. The research data, derived from the self-administered questionnaire method, was collected from 664 students in fifteen high schools during the spring of 2016. A total of 542 complete questionnaires were analyzed (response rate: 79.8%). Approximately 73% of the students self-reported having consumed energy drinks, with a greater percentage of male (as opposed to female) students self-reporting as having done so. The most common reasons given for the consumption of energy drinks were to stay awake (54.8%), the good taste of the drink (28.0%), to concentrate during studying (17.2%), and to relieve fatigue (16.9%). The adverse effects were palpitation (59.3%), insomnia (35.6%), and experiencing difficulty in waking up (30.5%). More than two in three (67.8%) students who experienced adverse effects still consumed energy drinks. The average level of health consciousness was lower than 3 out of 5 points. The results of the logistic regression analyses indicated a positive relationship between monthly allowance (OR=1.01 for male and female students) and the consumption of energy drinks by both male and female students. Among the male students, freshmen (OR=0.23) were less likely to have consumed energy drinks than juniors. Male students' sleeping hours (OR=0.65) and perceived school life satisfaction scores (OR=0.63) were negatively associated with the consumption of energy drinks. In the case of female students, study hours (OR=0.83) and energy drinks consumption were negatively related. These factors affecting energy drinks consumption could be considered in the development of dietary education programs aimed at protecting high school students from the adverse health impacts of energy drinks.

• Wind and Structures
• /
• v.23 no.2
• /
• pp.157-169
• /
• 2016

The structural integrity of tube bundles represents a major concern when dealing with high risk industries, such as nuclear steam generators, where the rupture of a tube or tubes will lead to the undesired mixing of the primary and secondary fluids. Flow-induced vibration is one of the major concerns that could compromise the structural integrity. The vibration is caused by fluid flow excitation. While there are several excitation mechanisms that could contribute to these vibrations, fluidelastic instability is generally regarded as the most severe. When this mechanism prevails, it could cause serious damage to tube arrays in a very short period of time. The tubes are therefore stiffened by means of supports to avoid these vibrations. To accommodate the thermal expansion of the tube, as well as to facilitate the installation of these tube bundles, clearances are allowed between the tubes and their supports. Progressive tube wear and chemical cleaning gradually increases the clearances between the tubes and their supports, which can lead to more frequent and severe tube/support impact and rubbing. These increased impacts can lead to tube damage due to fatigue and/or wear at the support locations. This paper presents simulations of a loosely supported multi-span U-bend tube subjected to turbulence and fluidelastic instability forces. The mathematical model for the loosely-supported tubes and the fluidelastic instability model is presented. The model is then utilized to simulate the nonlinear response of a U-bend tube with flat bar supports subjected to cross-flow. The effect of the support clearance as well as the support offset are investigated. Special attention is given to the tube/support interaction parameters that affect wear, such as impact and normal work rate.