• Journal of Energy Engineering
• /
• v.29 no.1
• /
• pp.1-12
• /
• 2020

The rapid climate change is strengthening carbon emissions regulations internationally. Korea is strongly pressed to accept the obligation to reduce greenhouse gases as one of the United Nations Framework Convention on Climate Change. This article analyzed the Granger causalities among environmental regulation, economic growth, electricity consumption, and CO₂ emission in Korea, using unit root test, cointegration test, and vector error correction model. As the results, environmental regulation has shown the bidirectional causalities with electricity consumption and CO₂ emission, while being unilaterally affected by economic growth in the long-run and strong relationship. Economic growth has affected electricity consumption, CO2 emission, and environmental regulation in the long-run, in the complex structure of the unilateral and short-run causality with electricity consumption and the bidirectional causality with CO2 emission. The policy implications will be as follows: ① environmental regulation should induce sustainable growth through encouraging technological innovation relating to CO2 reduction and productivity enhancement. ② Responding to the international CO2 reduction regulation, the synthetic policy initiatives will be considered to make synergy effects among policies relating to economic growth, electricity consumption.

• Science of Emotion and Sensibility
• /
• v.14 no.1
• /
• pp.17-26
• /
• 2011

Health care service's added value and sustainability has been formed, through the product developing about sports equipment and special equipment for disabled in order to improve the life quality, with the increasing population of elderly and the attention about health care. This research's design and 3 testing sections has been done according to design process for design development of functional bike. 1st test is done through researching from 4 aspects: structure, aesthetic, function and using. In the 2nd testing, 10 universal design items were used to evaluate 10 modeling samples, and sample F which has high evaluation overall was chosen. In 3rd test, evaluation was done from the user service scene about the mock-up with 1/4 scale size. PPP (product performance program) which is constructed with 60 evaluation items about functional bike's service was tested, and these items were fixed through discussing with experts. Through the result we knew the aesthetic elements had relationship with proportion, unity and typicality. In 10 items (55 survey items), the scores of items with physical exposure's minimization, simple and intuitively usage showed high, on the contrary, the other items' scores was very low, such as information delivery's consideration and thought, failure preventing. The evaluation will be done once more by health care experts, designers and elderly together if the physical model could be made for getting accurate measurement about above test result in the future.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.1115-1123
• /
• 2008

When constructing projects such as road embankments, bridge approaches, dikes or buildings on soft, compressible soils, significant settlements may occur due to the consolidation of these soils under the superimposed loads. The compressibility of the soil skeleton of a soft clay is influenced by such factors as structure and fabric, stress path, temperature and loading rate. Although it is possible to determine appropriate relations and the corresponding material parameters in the laboratory, it is well known that sample disturbance due to stress release, temperature change and moisture content change can have a profound effect on the compressibility of a clay. The early research of Tezaghi and Casagrande has had a lasting influence on our interpretation of consolidation data. The 24 hour, incremental load, oedometer test has become, more or less, the standard procedure for determining the one-dimensional, stress-strain behavior of clays. An important notion relates to the interpretation of the data is the ore-consolidation pressure ${\sigma}_p$, which is located approximately at the break in the slope on the curve. From a practical point of view, this pressure is usually viewed as corresponding to the maximum past effective stress supported by the soil. Researchers have shown, however, that the value of ${\sigma}_p$ depends on the test procedure. furthermore, owing to sampling disturbance, the results of the laboratory consolidation test must be corrected to better capture the in-situ compressibility characteristics. The corrections apply, strictly speaking, to soils where the relation between strain and effective stress is time independent. An important assumption in Terzaghi's one-dimensional theory of consolidation is that the soil skeleton behaves elastically. On the other hand, Buisman recognized that creep deformations in settlement analysis can be important. this has led to extensions to Terzaghi's theory by various investigators, including the applicant and coworkers. The main object of this study is to suggestion the modified compression index value to predict settlements by back calculating the $C_c$ from different numerical models, which are giving best prediction settlements for multi layers including very thick soft clay.

• Journal of the Microelectronics and Packaging Society
• /
• v.29 no.3
• /
• pp.49-53
• /
• 2022

Ultra-thin glass (UTG) has been widely used in foldable display as a cover window for the protection of display and has a great potential for rollable display and various flexible electronics. The foldable display is under impact loading by bending and touch pen and exposed to other external impact loads such as drop while people are using it. These external impact loads can cause cracks or fracture to UTG because it is very thin under 100 ㎛ as well as brittle. Cracking and fracture lead to severe reliability problems for foldable smartphone. Thus, this study constructs finite element analysis (FEA) model for the pen drop test which can measure the impact resistance of UTG and conducts mechanical modeling to improve the reliability of UTG under impact loading. When a protective layer is placed to an upper layer or lower layer of UTG layer, stress mechanism which is applied to the UTG layer by pen drop is analyzed and an optimized structure is suggested for reliability improvement of UTG layer. Furthermore, maximum principal stress values applied at the UTG layer are analyzed according to pen drop height to obtain maximum pen drop height based on the strength of UTG.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.9
• /
• pp.177-188
• /
• 2023

The purpose of this study is to develop and validate a scale for measuring digital literacy by identifying the factors consisting of digital literacy and extracting items for each factor. Preliminary items for the Delphi study were developed through the analysis of previous literature and the deliberation of the research team. As a result of two rounds of the expert Delphi study, 65 items were selected for the main survey. The validation of the items was carried out in the process of exploratory and confirmatory factor analyses, reliability test, and criterion validity test using the data collected in the main survey. As a result, a 4-factor structure composed of 31 questions(factor 1: digital technology & data literacy- 9 questions, factor 2: digital content & media literacy- 8 questions, factor 3: digital communication & community literacy- 9 questions, factor 4: digital wellness literacy - 5 questions) was confirmed. Also, the goodness of fit indices of the model were found to be good and the result of reliability test revealed the scale had a very appropriate level of Cronbach's alpha(α=.956). In addition, a statistically significantly positive correlations(p<.001) were found between digital literacy and internet self-efficacy and between digital literacy and self-directed learning ability, which were predicted in the existing evidence, therefore the criterion validity of the developed scale was secured. Finally, practical and academic implications of the study are provided and future study and limitations of the study are discussed.

• Asia Marketing Journal
• /
• v.11 no.3
• /
• pp.125-149
• /
• 2009

Many studies have been conducted to find the causal factors that influence salesforce performance and turnover behavior. This study focuses on the turnover intention of salesperson. Specifically this study argues that the causal relationship among job performance, job stress and turnover intention will be mediated by job conflict of salesperson. We develop the hypotheses from the conceptual framework and empirically test them for the salespersons of lifetime insurance companies. Based on the previous studies and conceptual framework developed in this study, we derive 8 hypotheses. <Figure 1> shows the conceptual framework from which hypotheses are derived. Hypotheses for the empirical test are as follows: H1: Job performance will have negative impact on the turnover intention. H2: Job performance will have negative impact on the job conflict. H3: Job stress will have the positive relationship with the turnover intention. H4: Job stress will have the positive relationship with the job conflict. H5: Job conflict will have the positive relationship with the turnover intention. H6: The negative impact of job performance on the job conflict will be moderated by job education/training. H7: The positive impact of job stress on the job conflict will be moderated by job training. H8: The positive impact of job conflict on the turnover intention will be moderated by the switching costs. To test the 8 hypotheses, we estimate the level of fitness and parameters of structure equation model by using AMOS 5.0. <Table 1> shows the results of empirical tests for hypotheses. <Table 2> shows the moderating effect of job training. <Table 3> shows the moderating effect of switching costs. This empirical study finds interesting results. The job training has the moderating effect on the causal relationship between job performance and job conflict. But it is found that the job training has not the moderating effect on the causal relationship between job performance and job conflict. These results may be due to the fact that Korean insurance company mainly focuses on training of the job skill and knowledge, not motivational elation of salesforce.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.6
• /
• pp.1061-1071
• /
• 2018

A subsea tunnel, being a super-sized underground structure must ensure safety at the time of earthquake, as well as at ordinary times. At the time of earthquake, in particular, of a subsea tunnel, a variety of response behaviors are induced owing to relative rigidity to the surrounding ground, or difference of displacement, so that the behavior characteristics can be hardly anticipated. The investigation aims to understand the behavior characteristics switched by earthquake of an imaginary subsea tunnel which passes through a fault zone having different physical properties from those of the surrounding ground. In order to achieve the aim, dynamic response behaviors of a subsea tunnel which passes through a fault zone were observed by means of indoor experiments. For the sake of improved earthquake resistance, a shape of subsea tunnel to which flexible segments have been applied was considered. Afterward, it is believed that a D/B can be established through 3-dimensional earthquake resistance interpretation of various grounds, on the basis of verified results from the experiments and interpretations under various conditions. The present investigation performed 1 g shaking table test in order to verify the result of 3-dimensional earthquake resistance interpretation. A model considering the similitude (1:100) of a scale-down model test was manufactured, and tests for three (3) Cases were carried out. Incident seismic wave was introduced by artificial seismic wave having both long-period and short-period earthquake properties in the horizontal direction which is rectangular to the processing direction of the tunnel, so that a fault zone was modeled. For numerical analysis, elastic modulus of the fault zone was assumed 1/5 value of the modulus of individual grounds surround the tunnel, in order to simulate a fault zone. Resultantly, reduced acceleration was confirmed with increase of physical properties of the fault zone, and the result from the shaking table test showed the same tendency as the result from 3-dimensional interpretation.

• Sleep Medicine and Psychophysiology
• /
• v.13 no.2
• /
• pp.67-74
• /
• 2006

Introduction: Excessive daytime sleepiness and cataplexy are key features of narcolepsy. Modafinil is psychostimulant used in the treatment of narcolepsy. In this study, we evaluated effects of modafinil on nocturnal sleep structure and sleep latency in multiple sleep latency test and clinical features. Methods: Twelve narcoleptic patients (7 male, age: $22.9{\pm}2.6\;yrs$) were participated in the study. All of them had done nocturnal polysomnography (nPSG), multiple sleep latency test (MSLT), clinical symptoms scales and have repeated same procedure after taking 200 mg of modafinil. We have done linear mixed model analysis to describe effects of group, medication and nap time on these measures. Results: Modafinil did not affect clinical scales except PSQI which had been reduced after medication. In this study, Modafinil reduced total sleep time, sleep efficiency and increased wake after sleep onset and percent of arousal during sleep in nocturnal polysomnography and prolonged mean sleep latency in multiple sleep latency tests in both group. Discussion: Modafinil has stimulant effect of central nervous system but its effect on night sleep is less than other psychostimulants such as methylphenidate. We ascertained that modafinil affected total sleep time, sleep efficiency and percent of wake during sleep but did not effect on sleep structure. Modafinil was effective in the management of day time sleepiness. Modafinil can enhance alertness of control group without day time sleepiness.

• The Korean Journal of Elementary Counseling
• /
• v.10 no.2
• /
• pp.185-201
• /
• 2011

The purpose of this study is to reveal and confirm the factor structure inherent in the Korean inventory of peer relationships(KIPR; Sang-Hwang Hong, et al., 2009) in order to strengthen the interpretive usefulness of the test. For this purpose, the inventory was administered to the total of 616 children in the fourth through sixth grades in three elementary schools located in Gyungnam area, and the data from 578 of them were analyzed. The results of the study can be summarized as follows. First, as a result of the exploratory factor analysis of 3-factor and 4-factor models, the 3-factor model was found to be more appropriate. In the 3-factor model, the factor 1 is named "Lack of Self-Confidence and Social Withdrawal" as it consists of such circumplex scale items as Non-Assertiveness (C5), Social Avoidance (C4), the Cold (C3), and Too Submissive (C6). The factor 2 is named "Too Aggressive and Controlling" and consists of items Too Controlling (C1) and Hard to be Supportive (C2). The factor 3 is named "Too Caring" and consists of items Too Responsible (C7), Over Involvement (C8), and Too Submissive (C6). Second, as a result of the confirmatory factor analysis, the 3-factor model, in comparison to the 4-factor model, was found to better reflect the collected data(RMSEA=.054), its goodness of fit was not satisfactory but within the acceptable range(CFI=.786), and its power of simplicity and clarity was also adequate(PCFI=.733). In the current study, through the exploratory and confirmatory factor analyses of scores from the Korean inventory of peer relationships circumplex scales, scales within the peer relationship circumplex model that are near each other and are highly correlated were confirmed to be grouped together as same factors. I believe the main merit of the study lies in the above result having provided the necessary foundation for forming the superordinate and representative scale that encompasses the eight circumplex scales, which enhances the test's interpretive usefulness.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.3
• /
• pp.213-220
• /
• 2019

Desire for a happy life becomes the will that man instinctively desires. In that the conditions of happiness are subjective and varied, the will of subjective desires has been studied with the attention of objective tendencies. The positive and meaningful will of life in the desire for happiness leads us to be the functionaries who act. These wills can be the driving force of a happy life, which allows one to have a hopeful reflective will in one's inner life, connecting oneself with others, and working in relationships with others. In addition, those who become lazy or lose their orientation in life can instill a will to be the main character of life, and furthermore, to give the ultimate meaning and goals of life. To understand and analyze these wills for happy lives more specifically, structural model compatibility and confirmatory factors were conducted. relatively reliable α=.855 value, the coefficient of correlation between recognition and will **p<.01, *p<.05 statistically significant measuring tool of not less than 05 was used. The study results of the structural model suitability of the factors of will and the confirmatory factor analysis showed that the model set by the researcher could reflect the characteristics of the data collected, and that the χ²(Chi-square) value was .126, which was consistent with the model by satisfying the acceptance criteria, and that the comparison of the reference values of the study model showed a relatively high level of suitability. To identify the relationship between cognitive and defined and behavioral factors of subjective will and existent will variables, the results of a verification factor analysis show that the χ²(Chi-square) value is 2.36 and the model and data are consistent with the acceptance criteria, and that the test data is consistent with the model and data set by the researcher are consistent with the model5.0 Through structural model analysis of human will, it was confirmed that the variables of subjective and existential, sensible and reflective will directly and indirectly influence and form a complex relationship. Our will is recognized as the subjective will, and the structure of the subjective will consists of the sensible and reflective will, and the relationship between the cognitive and just action elements and the subjective will of the human life and the will to exist is shown to be very meaningful, so we should conduct the education of the happy will of the emotional and just areas of life as well as the reestablishment of the cognitive educational direction that can lead to action.