• Sleep Medicine and Psychophysiology
• /
• v.9 no.1
• /
• pp.41-47
• /
• 2002

Objectives: In a number of simulated night shift studies, timed exposure to bright light improves sleep quality and work performance. We evaluated the effect of bright light on adaptation to night shift work with a field study. Methods: Five female nurses working shifts at Korea University Hospital were recruited for participation in this study. We investigated two series of six consecutive shift rotations comprising three day and three night shifts, using wrist Actigraphy, the Stanford Sleepiness Scale, Visual-analogue scales, STIM and tympanic membrane temperature for daytime sleep quality, alertness, subjective feeling, attention performance, and temperature rhythm. The subjects were exposed to bright light (2,500 lux) from 24:00 to 04:00 a.m. on three consecutive night shifts during the second series, whereas they worked under normal lightening (650 lux) conditions during the first series. Results: Actigraphic assessment of daytime sleep showed no significant difference between the first and third night shift in both baseline and light exposure phase. The mean lowest temperature shifted earlier during baseline phase but not during the light exposure phase. Also, the score for subjective feelings of depression, anxiety, physical discomfort and sleepiness was significantly higher in the third night shift than the first during baseline phase but not during the light exposure phase. Attention and attention switching ability was significantly improved in the third night shift compared to the first night during the light exposure phase but there were no significant changes during the baseline phase. Conclusion: This result suggests that there were no significant differences between the two phases in measures of quality of daytime sleep, but subjective feelings, attention and alertness were enhanced during light exposure. Although some placebo effects and learning effects might influence this result, bright light exposure between midnight and 4:00 a.m. may improve adaptation to night shift. In future, further controlled studies with a larger sample size, including melatonin measurement, are needed for real shift workers.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.15 no.1
• /
• pp.95-112
• /
• 2020

This paper is to investigate how cognitive bias of college students and entrepreneurs relates to perceived risks and entrepreneurial opportunities that represent uncertainty, and how various cognitive bias and entrepreneurial efficacy In the same way. The purpose of this study is to find improvement points of entrepreneurship education for college students and to suggest problems and improvement possibilities in the decision making process of current entrepreneurs. This empirical study is a necessary to improve the decision-making of individuals who want to start a business at the time when various attempts are made to activate the start-up business and increase the sustainability of the existing SME management. And understanding of the difference in opportunity evaluation, and suggests that it is necessary to provide good opportunities together with the upbringing of entrepreneurs. In order to achieve the purpose of the study, questionnaires were conducted for college students and entrepreneurs. A total of 363 questionnaire data were obtained and demonstrated through structural equation modeling. This study confirms that there is some relationship between perceived risk and cognitive bias. Overconfidence and control illusions among cognitive bias have a significant relationship between perceived risk and wealth. Especially, it is confirmed that control illusion of college students has a significant relationship with perceived risk. Second, cognitive bias demonstrated some significant relationship with opportunity evaluation. Although we did not find evidence that excess self-confidence is related to opportunity evaluation, we have verified that control illusions and current status bias are related to opportunity evaluation. Control illusions were significant in both college students and entrepreneurs. Third, perceived risk has a negative relationship with opportunity evaluation. All students, regardless of whether they are college students or entrepreneurs, judge opportunities positively if they perceive low risk. Fourth, it can be seen from the college students 'group that entrepreneurial efficacy has a moderating effect between perceived risk and opportunity evaluation, but no significant results were found in the entrepreneurs' group. Fifth, the college students and entrepreneurs have different cognitive bias, and they have proved that there is a different relationship between entrepreneurial opportunity evaluation and perceived risk. On the whole, there are various cognitive biases that are caused by time pressure or stress on college students and entrepreneurs who have to make judgments in uncertain opportunities, and in this respect, they can improve their judgment in the future. At the same time, university students can have a positive view of new opportunities based on high entrepreneurial efficacy, but if they fully understand the intrinsic risks of entrepreneurship through entrepreneurial education and fully understand the cognitive bias present in direct entrepreneurial experience, You will get a better opportunity assessment. This study has limitations in that it is based on the fact that university students and entrepreneurs are integrated, and that the survey respondents are selected by the limited random sampling method. It is necessary to conduct more systematic research based on more faithful data in the absence of the accumulation of entrepreneurial research data. Second, the translation tools used in the previous studies were translated and the meaning of the measurement tools might not be conveyed due to language differences. Therefore, it is necessary to construct a more precise scale for the accuracy of the study. Finally, complementary research should be done to identify what competitive opportunities are and what opportunities are appropriate for entrepreneurs.

• Asia pacific journal of information systems
• /
• v.24 no.3
• /
• pp.255-279
• /
• 2014

It is not too much to say that smartphones have become an essential part of our lives due to their versatility. Nevertheless, they still have less overall capabilities than their desktop counterparts. Specifically, they have small screens and low resolutions, which make their applications difficult to have a usable interface. To account for these limitations, the interface of smartphone applications should be designed carefully and properly. Good interface design to any application is critical. However, a comprehensive information systems (IS) literature review found that there has been little research on the user interface design of smartphone applications. More specifically, there has been little empirical evidence and understanding about how metaphors, an imaginative way of describing objects and concepts, in the user interface of smartphone applications affect users' intention to use the applications. Thereby, the research goals of this study are to examine 1) the effects of the metaphors in the user interface of smartphone applications on the interaction between users and applications and 2) the effects of mediating variables including the interaction between users and applications, users' beliefs and attitudes, on users' intention to use the applications. A survey was conducted to collect data. University students and practitioners participated in the survey. A 24-item questionnaire was developed on a 5-point Likert-type scale. The measurement items were mostly adapted from the previous studies in the IS literature and modified to fit the context of this study. First, a principal component factor analysis was performed to explore the inter-relationships among a set of variables. The analysis showed that most of the items loaded quite strongly on the six components. The analysis also revealed the six components with eigenvalues exceeding 1, explaining a total of 70.7 per cent of the variance. The reliabilities of the items were also checked. Most Cronbach alpha values were above 0.8, so the scales were considered reliable. In sum, the results of the analysis support the decision to retain the six factors for further investigation. Next, the structural model was analyzed with AMOS structural equation modeling. The values of GFI, AGFI, NFI, TLI, CFI, and RMSEA were checked. The values showed that the research model considerably have a good fit in general. Next, the convergent and discriminant validities of all constructs were examined. The values for the standardized regression weights and critical ration (CR) indicated sufficient convergent validity for all constructs. In addition, the square root of the average variance extracted (AVE) of each construct was compared with its correlations with all other constructs. The results supported discriminant validity for all constructs. In sum, the results of analysis demonstrated adequate convergent and discriminant validities for all constructs. Finally, path coefficients between the variables were examined. Methphor was found to have an impact on interaction (${\beta}$ = .457, p = .000). There were also significant effects of the interaction on perceived usefulness (${\beta}$ = .273, p = .000) and ease of use (${\beta}$ = .405, p = .000). User attitude was significantly influenced by these two beliefs, perceived usefulness (${\beta}$ = .386, p = .000) and ease of use (${\beta}$ = .347, p = .000) respectively. Further, the results of analysis found that users' intention to use smartphone applications was significantly influenced by user attitude (${\beta}$ = .567, p = .000). Based upon the analyses, all hypotheses were supported. This study found that the metaphors used in the interface of smartphone applications affect not only the interaction between users and applications, but also users' intention to use the applications through the mediating variables, perceived usefulness and ease of use. These findings imply that if the metaphors used in the user interface of application are easy enough to understand for smartphone users, then the application can be perceived useful and easy to use, which in turn make users to have an intention to use the application. In conclusion, this study contributed not only to validate and extend Technology Acceptance Model (TAM) partially, but also to develop the construct of metaphor in smartphone settings. However, since a single empirical study cannot be enough to validate the findings, some limitations should be considered.

• Investigative Magnetic Resonance Imaging
• /
• v.18 no.2
• /
• pp.151-156
• /
• 2014

Purpose : Spin-echo (SE) technique is most commonly used pulse sequence for T1-weighted MR imaging. T1-weighted fluid-attenuated inversion recovery (T1FLAIR) is a relatively new pulse sequence and it provides higher tissue contrast between the gray matter (GM) and white matter (WM) of the brain than T1-weighted SE (T1SE) sequence. However, there has been controversy for the evaluation of enhancing brain tumors with T1FLAIR compared to T1SE. The purpose of this study was to compare T1FLAIR and T1SE sequences for the evaluation of enhancing intracranial tumors. Materials and Methods: Fifty-two patients with enhancing brain tumors were evaluated with contrast-enhanced (CE) T1SE and T1FLAIR imaging. Eight quantitative criteria were calculated: lesion-to-WM contrast ratio (CR) and contrast-to-noise ratio (CNR), lesion-to-GM CR and CNR, lesion-to-CSF CR and CNR, and WM-to-GM CR and CNR. For qualitative evaluation, two radiologists assessed lesion conspicuity on CE T1SE and T1FLAIR sequences with three-scale: 1, T1SE superior; 2, sequence equal; T1FLAIR superior. Results: Seventy-nine tumors (31 primaries, 48 metastases) were assessed. For quantitative measurement, the T1FLAIR lesion-to-GM, lesion-to-CSF, WM-to-GM CR and CNR values were comparable and statistically superior to those of the T1SE images (p < 0.001 in all). However, lesion-to-WM CR and CNR were similar on both two sequences without statistically significant difference (p = 0.661, 0.662, respectively). For qualitative evaluation, both radiologists assessed that T1FLAIR images were superior to T1SE images for the evaluation of lesion conspicuity. Conclusion: For the evaluation of enhancing intracranial tumors, T1FLAIR sequence was superior or comparable to T1SE sequence.

• 모자간호학회지
• /
• v.2 no.1
• /
• pp.21-33
• /
• 1992

This study was done to investigate how importantly midwives thought of Lamaze Method of Childbirth, how satisfactorily they performed their Lamaze Method of Childbirth and what inhibited their activities from being performed if not done satisfactorily. The subjects of this study were 76midwives at midwifery in Pusan, Deagu, Kyungnam and Kyungbok. Data were collected by using questionaire from Sep. 1 to Sep.30, 1991. The measurement tools was maded by the researcher based on Kim's scale for prenatal nursing activities. The statistical analysis was done with based statistical values likes frequencies, means, standard deviations and advanced methods such as Pearson's correlation coefficient, 1-test, F-test, F-test by using SPSS package program. The results of this study can be summarized as follows ; 1. The results of Investigating perception according to importance degree and performance degree of Lamaze Method of Childbring showed that midwives were slightly below both perception according to importance(2.17) and performance(2.16) of Lamaze Method of Childbirth 2. Inhibiting factors of Lamaze Method of Childbirth were abscence of husband(3.08), lack of teaching room(2.71), and lack of books or literature of Lamaze Method (2.58). 3. There appears to be a positive relation between perception according to importance degree and performance degree of Lamaze Method of Childbirth (r=0.69, P<0.01). There appears to be a negative relation between perception according to importance degree and inhibit factors of performance (r=-0.38, P<0.01). There appears to be a negative relation between performance and inhibit factors of performance (r=-0.22. P<0.01). 4. The item of highest perception defree in prenatal education is 1st, Consultation about sexual life (2.53), End, illustration of the importance of a bath and perinal cleanliness and Avoidance of excessive respiration method and also its comfortable application during uterine contractility(2.45). The item of lowest perception degree is about pregnant symptom sign and predicted date of birth (E.D.C.). On the other hand, The item of highest performance degree is education about nurtrition during pregnacy. 2nd, Illustration of the Importance of a bath and perineal cleanness(2.45). The lowest one is leaching the pregnant woman and her family about the role of husband and her family and also teaching the couple to learn exercise and respiration method (1.84). Though importance perception degree and performance degree is low. Midwives who wert subject in this research shoves that they perform general items concerning prenatal education well. 5. In the relationship between perception according to importance degree of Lamaze Method of Childbirth and the general characteristics of subjects, the differences in mean number of visiting pregnacies for 1 month. 6. In the relationship between performance degree of Lamaze Method of Childbirth and the general characteristics of subjects, the differences in age, marriage, and mean number of visiting pregnancies for 1 month. With the above information we see the importance of midwife prenatal care education and high correlation between performance degree and perception degree. When Lamaze prenatal education is well performed the number of pregnant woman who have follow-up, check-ups increase. Therefore in this research we can validity that there is a relation between Lamaze prenatal education and patient follow-up. This research showes in a situation where if one does not maximally perform a prenatal education there is a possibility that the popular use of midwife activities may encounter obstacles so the education to save new knowledge and training for prenatal education is needed as a function of Lamaze prenatal education, when a special Lamaze education is well performed for the pregnant woman, who follows-up at amidwife clinic. With the above conclusion we can suggest : 1. Continued research which minimized obstacles to Lamaze prenatal education is needed. 2. The official method of midwives is necessary.

• Korean Journal of Food Science and Technology
• /
• v.35 no.6
• /
• pp.1064-1071
• /
• 2003

An investigation of various olive oils available in Korea was carried out to assess their quality properties such as color, oxidative stability, fatty acid composition, tocopherol content, sterol content and benzo(a)pyrene content. In color measurement, by using a Lovibond color scale and Hunter color difference meter, both a and b values of extra virgin olive oil were higher than those of pure olive oil by Tintometer (Lovibond PFX995). However, extra virgin olive oil showed higher a value and lower L value than pure olive oil by the Hunter color difference meter. In the rancimat test, the induction period of extra virgin olive oil $(38.03{\sim}8.47hr)$ was longer than that of pure olive oil $(32.40{\sim}9.94hr)$. In fatty acid composition, C18:1 $(72.01{\sim}78.53wt%)$ was present in the greatest amount, with lesser amounts of C18:2 $(4.88{\sim}10.36wt%)$ and C18:3 $(0.56{\sim}1.09wt%)$. The tocopherol content ranged from ${\alpha}-Toc\;4.09{\sim}13.89mg/100g$, ${\beta}-Toc\;0.57{\sim}1.34mg/100g$, and ${\gamma}-Toc$ $3.41{\sim}8.03mg/100g$, and ${\alpha}-tocopherol$ was found to be the main isomer in all oil samples. Therefore, there was little difference in the fatty acid composition and tocopherol content among the different types of olive oils. In sterol content, ${\beta}-sitosterol$ $(124.52{\sim}19.33mg/100g)$ and campesterol $(1.10{\sim}0.62mg/100g)$ of extra virgin olive oil were higher than that of pure olive oil $({\beta}-sitosterol\;92.68{\sim}17.44mg/100g,\;campesterol\;0.59{\sim}0.35mg/100g)$. Benzo(a)pyrene was found in almost all samples, with $0.287{\sim}0.106{\mu}g/kg$ in extra virgin olive oil and $1.204{\sim}2.130{\mu}g/kg$ in pure olive oil.

• Economic and Environmental Geology
• /
• v.43 no.1
• /
• pp.13-20
• /
• 2010

Acid mine drainage (AMD) from abandoned mine sites typically has low pH and contains high level of various heavy metals, aggravating ground- and surface water qualities and neighboring environments. This study investigated removal of heavy metals in a biological treatment system, mainly focusing on the removal by adsorption on a substrate material. Bench-scale batch experiments were performed with a mushroom compost to evaluate the adsorption characteristics of heavy metals leached out from a mine tailing sample and the role of SRB in the overall removal process. In addition, adsorption experiments were perform using an artificial AMD sample containing $Cd^{2+}$, $Cu^{2+}$, $Pb^{2+}$ and $Zn^{2+}$ to assess adsorption capacity of the mushroom compost. The results indicated Mn leached out from mine tailing was not subject to microbial stabilization or adsorption onto mushroom compost while microbially mediated stabilization played an important role in the removal of Zn. Fe leaching significantly increased in the presence of microbes as compared to autoclaved samples, and this was attributed to dissolution of Fe minerals in the mine tailing in a response to the depletion of $Fe^{3+}$ by iron reduction bacteria. Measurement of oxidation reduction potential (ORP) and pH indicated the reactive mixture maintained reducing condition and moderate pH during the reaction. The results of the adsorption experiments involving artificial AMD sample indicated adsorption removal efficiency was greater than 90% at pH 6 condition, but it decreased at pH 3 condition.

• Economic and Environmental Geology
• /
• v.50 no.4
• /
• pp.303-311
• /
• 2017

The laboratory scale experiment was performed to evaluate the sealing capacity of the capping rock such as tuff and mudstone, measuring the intial supercritical $CO_2$ ($scCO_2$) injection pressure and the $scCO_2$-water-rock reaction for 90 days. The drilling cores sampled from 800 m in depth around the Janggi basin, Korea were used for the experiment. The mineralogical changes of mudstone and tuff were measured to evaluate the geochemical stability during the $scCO_2$-water-rock reaction at $CO_2$ storage condition (100 bar and $50^{\circ}C$). The rock core was fixed in the high pressurized stainless steel cell and was saturated with distilled water at 100 bar of pore water pressure. The effluent of the cell was connected to the large tank filled with 3 L of water and 2 L of $scCO_2$ at 100 bar, simulating the subsurface injection condition. The $scCO_2$ injection pressure, which was higher than 100 bar, was controlled at the influent port of the cell until the $scCO_2$ begin to penetrate into the rock and the initial injection pressure (> 100 bar) of $scCO_2$ into the rock was measured for each rock. The mineralogical compositions of mudstones after 90 days reaction were similar to those before the reaction, suggesting that the mudstone in the Janggi basin has remained relatively stable for the $scCO_2$ involved geochemical reaction. The initial $scCO_2$ injection pressure (${\Delta}P$) of a tuff in the Janggi basin was 15 bar and the continuous $scCO_2$ injection into the tuff core occurred at higher than 20 bar of injection pressure. For the mudstone in the Janggi basin, the initial $scCO_2$ injection pressure was higher than 150 bar (10 times higher than that of the tuff). From the results, the mudstone in Janggi basin was more suitable than the tuff to shield the $scCO_2$ leakage from the reservoir rock at subsurface.

• Korean Journal of Occupational Health Nursing
• /
• v.4
• /
• pp.5-29
• /
• 1995

Occupational health services in Korea have been operated as dual types : one is operated by occupational health care manager and the other is health care agency without their own personnel. The performance of occupational health service should be different due to the variety of characteristics of health care manager and workplace, qualification of health care manager. This study is to analyze performance of occupational health care services with a particular consideration of job performance shape and efficiency, based on comparing those two types of health care management to show on the basic data for the settlement of more qualitative health care management system at workplace. For this study, total 391 places in Seoul and Inchon city area ; 154 places (39.4%) managed by designated health care manager and 237 places (60.6%) by the agency with their commission are selected as research samples. Tools for data collection are questionnares that have been investigated during the period of 20 September 1993-20 December 1993. Those data are compared with percentiles, mean, standard deviation and B/C ratio using SPSS PC program. Conclusions observed from the tests and each comparison could be summerized as follows : 1. Occupational health care have been accomplished at workplaces with designated people than with agencies people, and coverage rate of the occupational health care services has differences, due to management types. The reason of these results is due to visit only one or two times monthly by the agencies, while their own health care manager obsess, at the workplaces all the times. 2. Most of the expense for environmental control of all health care services expenditures shows that there is almost no fundamental improvement because more expenses are needed for procuring personal protective equipment and measuring work environment instead of environmental improvement. 3. It is investigated how much the cost of occupational health care services needs per worker, and calculated how much the cost needs per service hour per worker. The results from this show that the cost of occupational health services at workplaces with their own managers used less than the cost of health care agencies, eventually the former gives better services with less cost than the latter. 4. Benefit/Cost ratio is also produced by total benefit/total cost. The result from the above way reads 4.57 as a whole, while their own manager having workplaces reads 4.82 and the agencies do l.56. Even if their own manager performing workplaces spent more cost, this system produces more benefit than the agencies management. 5. The B/C ratio for medical organization such as local clinic, health care center and pharmacy shows more than or equal to at the workplaces controlled by the agencies. It is inferred that benefit would be much less than the cost used, with so being inefficient. 6. It is assumed that the efficiency ratio of health education is equal to reduction rate of workers medical organization visit. Estimated reduction rate 5%, 10%, 15%, show that the efficiency ratio of health education have an effect on producing benefits. It is estimated that more benefit can be produced if more qualitative education will be provided for enhancing health care efficiency. 7. Results of this study cannot be generalized because there are large scale of deviation in case of workplaces with less than 300 full time workers, but B/C ratio reads 2.69 as a whole and 3.25 at workplaces with their own health care manager are higher than 1.63 at the workplaces manged by the agencies. Finally, all the benefit concerning health care services could not be quantified, measured and shown on the value of money. This is a reason that a considerable part of benefits are so underestimated. This is also thought that measurement tools should be developed for measuring benefits of health care services with a comprehensive quantification. in the future. It is also expected that efficiency of occupational health care services should be investigated using cost-effectiveness analysis.

• Cartoon and Animation Studies
• /
• s.26
• /
• pp.131-156
• /
• 2012

As the Global Age has arrived, the domain of festivals has expanded to fulfill the role of being not only a tourist attraction but of being a factor that determines the image and identity of cities, and the factor of enhancing the brand value of a particular city is being focused upon. The city of Bucheon, which aims to be a culture oriented city, is attempting to utilize the Bucheon International Comics Festival as a cultural asset for the revitalization of the city. This study has as its purpose the development of an evaluation index model on the brand value of the Bucheon International Comics Festival and research being conducted based on the developed evaluation index model on the awareness level of the citizens of Bucheon of the festival. In regards to this, the theoretical background was examined and the index model was developed based on precedent research. Based on this, a survey of 1,000 citizens of Bucheon was conducted in this study. This study conducted a survey targeting 500 persons, dividing them into 2 groups according to whether they participated in the festival. The survey of this study established 9 evaluation categories for the International Comics Festival evaluation index model which consists of demographic research and participation motivation, value of comics, festival brand awareness and association image, perceived product quality and loyalty for the festival, internationality of the festival and urban activation. Each survey question is composed of 5 points scale measurement. As a result of the survey, 'for an education of children' was the highest for the participation motivation, and 'not knowing of the festival information' was the highest for the reason of not having participated. The industrial value was evaluated as the highest among the value of comics by the both two groups, and it was studied that there was perception gap for the festival according to whether they participated in the festival for each survey question. It was revealed that the level of awareness of the Bucheon International Comics Festival was "normal," the "city revitalization" index and the "value of comics" index were relatively high and the "international character of the festival" index was the lowest. Furthermore, it was shown that there were differences in the awareness of the established categories of the developed evaluation index model based on whether or not there was participation in the festival. This study comprehensively organizes these analytical results and derives implications which can be used as data for the criteria of the development of future strategy for the Bucheon International Comics Festival.