• 가정과삶의질연구
• /
• 제34권5호
• /
• pp.35-52
• /
• 2016

The purpose of this study was to compare college students' emoticon use for positive behavior and to analyze the impact of the factors. This study is consisted of 66 questions based on Social demographic characteristics, personality characteristics factors and both scales of emotional expression. The operational test was administered to 340 college students. In an effort to calibrate emoticon use of positive behavior, the results displayed significance differences depending on the gender and grade of the students. Women used more emoticons than men, and freshman used more emoticons than any other year of students. Women used more emoticons such as texts, images, and flash more than men. Students in their freshman year were shown to use more emoticons than students in other grade levels. Emotional expression was strongly related man with personality traits of integrity. Personality traits of sensitivity, openness, intimacy, and sincerity had a significant influence on the emotional expression. An emoticon is, therefore, be a useful tool to express their emotions. Male and female students with higher levels of congeniality had expressed more emotions that were self-defence ambivalent and concerned-relation ambivalent. However, in the case of the female students, those with higher levels of self-defence ambivalent emotional expressiveness had a lower usage of positive emoticons, while male students with higher levels of self-defence emotional expressiveness used more positive emoticons. Higher levels of congeniality among groups that use mobile emoticons with their parents, whether the frequency of use was high or low, were associated with higher levels of self-defence ambivalence and concerned-relation ambivalence. Those with higher levels of sincerity had low levels of self-defence ambivalence and concerned-relation ambivalence, and those with higher levels of concerned-relation ambivalence had higher levels of positive emoticon usage.

• 한국자동차공학회논문집
• /
• 제19권1호
• /
• pp.125-132
• /
• 2011

The dynamic characteristics of valve train are responsible for the dynamic performances of engine. We derived the equation of motion for 6 degrees of freedom model of the valve train. Computer model is also developed with flexible multibody model considering contact between components. The simulation results with these two models are compared with experimental results. We investigated the effect of the two spring models, TSDA (Translational Spring Damper Actuator) element and flexible body model, on the valve behavior and spring force. It is found that the dynamic behavior of the two models are not very different at normal operational velocity of the engine. By modeling contact between cam and tappet, the stress distributions of the cam were found. Using stress distribution obtained, contact width and contact stresses of the cam surface were calculated with Hertz contact theory.

• 한국항공운항학회지
• /
• 제18권1호
• /
• pp.1-10
• /
• 2010

Structures under high temperature may have creep behavior and fatigue behavior. Durability study of the structures need the damage analysis with the creep-fatigue effects. In this paper, the damage analysis is studied for a turbine blade in the turbopump for a liquid rocket engine which is operated under high temperature condition. First of all, the load cycle is required for defining the operational characteristics of turbopump. The thermal stress analysis is done for a turbine blade of the turbopump. The stress analysis results are used to judge damage due to the creep and the fatigue. The strain-life method with miner rule is used for fatigue damage analysis. The Larson-Miller parameter master curve and robinson rule are used for the creep damage analysis. The linear damage summation method is used to consider creep-fatigue effects of turbopump turbine. Finally, the analysis results for fatigue and the influence are compared to figure out the damage phenomenon of the turbopump turbine.

• 한국도로학회논문집
• /
• 제20권3호
• /
• pp.75-84
• /
• 2018

PURPOSES: This study analyzes feasibility for application white pavement markings in the roadways with median barrier. METHODS : By reviewing numerous relevant laws, standards, and operational cases, the white pavement markings' excellence was demonstrated. Driver's behavior was analyzed through a virtual driving experiment using driving simulator and field tests. RESULTS:First, white pavement markings are superior to yellow pavement markings in terms of visibility, economics, and safety. Second, as a result of virtual driving experiment, the color of line in the roadway with median barrier didn't affect the driver's behavior such as the average vehicle speed, the distance bias in the lane and the separation distance from the centerline. Third, field test demonstrated that the driver tended to recognize the median barrier as an obstacle. In addition, the central driving ratio in the lane was increased due to improving the visibility of line at night in case of the white pavement markings. CONCLUSIONS : The application of white pavement markings in the roadways with median barrier can enhance traffic safety by improving the visibility of line at night.

• 한국자동차공학회논문집
• /
• 제8권5호
• /
• pp.54-66
• /
• 2000

A gasoline direct injection single cylinder engine has been developed to study operational characteristics for highly stratified conditions. Parameters related to design and experiment were also studied to understand the characteristics of combustion and emissions at some part load conditions. It was found that optimal timings between the end of fuel injection and spark ignition were existed for stable combustion under the stratified modes, In a low engine speed, fuel spray behavior around piston bowl was important for stable combustion. The in-cylinder air motion affecting fuel spray behavior was found to be a dominant factor at higher engine speed as fuel injection timing had to be advanced to secure enough time for fuel evaporation and mixing with surrounding air. As swirl ratio increased, spark timing could be advanced for stable combustion and a higher compression ratio could be used for improved fuel consumption and stable combustion at the stratified mode. It was also observed that electrode geometry and piston bowl shape played an important role for combustion and emission characteristics and some results were shown for comparison.

• Safety and Health at Work
• /
• 제5권2호
• /
• pp.53-59
• /
• 2014

Background: In a safety perspective, efficient knowledge management is important for learning purposes and thus to prevent errors from occurring repeatedly. The relationship between knowledge exchange among employees and safety behavior may be of particular importance in distributed organizational systems where similar high-risk activities take place at several locations. This study develops and tests hypotheses concerning the relationship between knowledge exchange systems usage, knowledge exchange in the organizational system, and safety compliance. Methods: The operational context of the study is petroleum drilling and well operations involving distributed high-risk activities. The hypotheses are tested by use of survey data collected from a large petroleum operator company and eight of its main contractors. Results: The results show that safety compliance is influenced by use of knowledge exchange systems and degree of knowledge exchange in the organizational system, both within and between units. System usage is the most important predictor, and safety compliance seems to be more strongly related to knowledge exchange within units than knowledge exchange between units. Conclusion: Overall, the study shows that knowledge management is central for safety behavior.

• 정보관리학회지
• /
• 제20권2호
• /
• pp.177-198
• /
• 2003

정보시스템의 최근 개발 경향은 이용자 중심이다. 이 연구는 이용자 중심적 PDL을 개발할 때 실질적으로 활용할 수 있는 실험적 모형을 제시하였다. 개념적 모형에서는 다양한 정보입수를 위한 외부시스템과의 연계 및 시스템전반에 개인의 정신모형과 함께하는 관리형태를 가질 수 있는 모형을 제시하였고, 물리적 모형에서는 연구자의 개발경험을 토대로 툴의 기능을 최대한 활용하였으며, 시스템개발에 곧 바로 적용할 수 있는 과정까지를 진행하였다.

• ETRI Journal
• /
• 제40권5호
• /
• pp.613-623
• /
• 2018

The instability of operational channels on cognitive radio networks (CRNs), which is due to the stochastic behavior of primary users (PUs), has increased the complexity of the design of the optimal routing criterion (ORC) in CRNs. The exploitation of available opportunities in CRNs, such as the channel diversity, as well as alternative routes provided by the intermediate nodes belonging to routes (internal backup routes) in the route-cost (or weight) determination, complicate the ORC design. In this paper, to cover the channel diversity, the CRN is modeled as a multigraph in which the weight of each edge is determined according to the behavior of PU senders and the protection of PU receivers. Then, an ORC for CRNs, which is referred to as the stability probability of communication between the source node and the destination node (SPC_SD), is proposed. SPC_SD, which is based on the obtained model, internal backup routes, and probability theory, calculates the precise probability of communication stability between the source and destination. The performance evaluation is conducted using simulations, and the results show that the end-to-end performance improved significantly.

• 제어로봇시스템학회논문지
• /
• 제19권10호
• /
• pp.947-954
• /
• 2013

This article focuses on a hemispherical resonator gyro driven by the Coriolis effect. The operational principle of resonator gyros and mathematical models are introduced. These models are useful to explain the behavior of a resonator and to design controllers. Several control tests of a resonator have been done. A resonator has been excited by electromagnets controlled by a computer. Its amplitude has been adjusted by a PI control. The transient response is matched with a simulation result based on a mathematical model. A vibrating pattern may drift due to non-uniform factors of a resonator. The drift of the vibrating pattern is controlled and aligned to a reference direction by a PI control. These results are very useful to understand the behavior of resonator gyros and to design advanced control algorithm for better performance.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집B
• /
• pp.222-227
• /
• 2001

This paper introduces the spring-mounted odometer system which maintains the correct contact with the pipe wall and measures the distance along the pipe. The odometer wheel is designed to keep contact to the pipelines inner wall and to generate fifty rectangular pulses per one turn(l59.5681mm) during pigging. The pipeline has the defects in various types such as buckles, winkles, cracks, dents, welding point and so on. Specially, girth welding points which exist each 12m of the pipeline, much affects the operational environment of the odometer. The measurement error of the distance along the pipe is accumulated, for the measurement error of wheel's circumference and the pipeline inner environment. So, this paper proposes the method for the error compensation based on the analysis of the odometer's behavior around the girth welding point of pipe. The experimental results show that developed odometer system can be used for the intelligent pig with good performances.