• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.43-52
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• 2011

LED lighting may cause different sensation and color appearance due to the different spectral power distributions compared to those of conventional lightings. Particularly, the CCT (Correlated Color Temperature) of LED lighting has a major effect on color appearance so that this study conducted an experiment through a subjective evaluation and luminance measurement for effective color appearance in a space. This study performed a subjective evaluation under the seven different LED CCT conditions, and color appearance was evaluated with major five colors in a customized lighting box. In addition, luminance measurement was conducted for each CCT and color condition to compare the results from a subjective evaluation. The results of this study may help to select a proper LED CCT for specific color conditions.

• Journal of the Ergonomics Society of Korea
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• v.32 no.2
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• pp.167-177
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• 2013

Objective: This study aims to compare the usefulness of subjective measures which are comprised of existing methods like NASA-TLX, Bedford-scale and ZEIS and newly developed method like DALI in measuring drivers' mental workload in terms of validity, sensitivity and diagnosticity. Background: Nowadays, with the development of intelligent vehicle and HMI, mental workload of driver has become more and more important. For this reason, the studies on drivers' mental workload about driving situation and the use of information technology equipment such as mobile phones and navigations were conducted intensively. However, the studies on measuring drivers' mental workload were rarely conducted. Moreover, most of studies on comparison of subjective measures were used with performance based measure. However, performance based measures can cause distraction effect with subjective measures. Method: Participants (N=19) were engaged in a driving simulation experiment in 2 driving contexts (downtown driving and highway driving context). The experiment has 2 sessions according to driving contexts. The level of difficulties by driving contexts were adjusted according to existence of intersections, traffic signs and signals, billboards and the number of doublings. Moreover, as criteria of concurrent validity and sensitivity, the EEG data were recorded before and during the sessions. Results: The results indicated that all subjective methods were correlates with EEG in high-way driving. On the contrary to this, in downtown driving, all subjective methods were not correlates with EEG. In terms of sensitivity, multi-dimensional scales (NASA-TLX, DALI) were the only ones to identify differences between high way and downtown driving. Finally, in terms of diagnosticity, DALI was the most suitable method for evaluating drivers' mental workload in driving context. Conclusion: The DALI as newly developed method dedicated to evaluate driver's mental workload was superior in terms of sensitivity and diagnosticity. However, researchers should consider the characteristics of each subjective method synthetically according to research objective by selecting the method in subjective measures. Application: The results of this study could be applied to the intelligent vehicle and next generation of HMI design to decrease mental workload of driver and for the development of new subjective method in vehicle domain.

• Journal of the military operations research society of Korea
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• v.24 no.1
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• pp.41-57
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• 1998

Since the aircraft has a property of moving in the three-dimensional space, it may cause personally and financially critical damage in the case of an accident. Among the causes of aircraft accident, human factor has occupied about 70% of all accidents. Specially, fatigue among human's problems has been studied earlier than any other factor. Fatigue has been the cause of 75% of accidents that are related to human factor. So many studies have been conducted. But the direction of these studies mainly attach importance to the sleep loss and circadian rhythm. Limitation for flight time of ICAO is 8 hours per day, civil airlines in domestic line also adopt the limitation. But this rule is not based on human's performance but compromise between labor and management. The long-haul flight brings about a mental block to pilot. This mental block decreases performance of pilot and loses a lot of important information. So this may cause many accidents. This paper is to offer optimal flight time according to the amount of fatigue due to increasing flight time. The optimal flight time is searched through the field experiment. The experiment has adopted two methods. One is to examine pilot's objective fatigue accumulation rate through the critical fusion frequency, and another is to investigate pilot's subjective fatigue feeling through the fatigue subjective symptoms investigation table.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.5
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• pp.355-364
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• 2011

Introduction: This study evaluated nerve recovery through retrospective study of patients with lingual nerve damage. Patients and Methods: The patients who visited Seoul National University Dental Hospital for an injury to the lingual nerve from April 1988 to August 2009 were enrolled in this study (n=41). The relevance of various factors including the causes of damage, age, etc. was analyzed by the subjective improvement based upon questionnaires and the clinical records. The evaluation variants were a subjective assessment and neurosensory examination composed of the direction, contact threshold, two-point discrimination, pin prick, thermal discrimination and current perception threshold. Results: The causes of lingual nerve damage were an extraction of the lower third molar (75.6%), local anesthesia (9.7%), incision and drainage (4.88%), trauma (2.44%). The evaluation of subjective prognosis exhibited no difference in sensory improvement depending on the cause, age and gender. Based upon the subjective evaluation, 44.7% of patients showed sensory improvement. The first hospital visit from injury was shorter in the group showing subjective improvement (3.41 months) than those showing no improvement (5.24 months) (P=0.301). Thirty six out of 41 patients were treated with only conservative therapy and 5 patients were treated by surgical intervention. Neurosensory examinations revealed improvement, although not statistically significant, and the degree was higher in the subjectively improved group. The contact threshold discrimination showed the highest correlation with subjective improvement (P=0.069). Most of the sensory recovery was gained within 12 months and the degree of improvement at the tip of the tongue was higher than that of the dorsum (P<0.001). Conclusion: The damaged lingual nerve improved at a rate of 44.7% and mostly within 12 months after the incident. There was no difference between the subjective prognosis and neurosensory examination depending on the cause of damage, age and gender, whereas the contact threshold discrimination was the best variant that reflected the subjective prognosis statistically.

• Journal of environmental and Sanitary engineering
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• v.21 no.4 s.62
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• pp.1-10
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• 2006

This research is based on self-filling survey which 220 dental hygienists who work in seoul participated on July 2006 through August 2006. This survey was analyzed the experience item and occurred time of the symptoms and the time of acute and vanish of the symptoms that dental office's working environment effects on physical subjective symptom. We suggest a plan to minimizing physical subjective symptom for health manage of dental hygienist. We found out the fact that dental hygienists were unsatisfied with hospital air condition and this polluted air condition cause them physical subjective symptom in work place. As follows analyzed results ventilation time is below the 3-times a day, this may be have some trouble in indoor air quality. The experience the symptoms level is higher then non-experience level in "Fatigue and sleepiness", "Dorsalgia, omarthralgia, cervicodynia", "Hypersensitivity", "Dry eye, itch, smarting", "Headaches" and a subjective symptom is occurred at after 11:00(am) more then 60%, 50% of the dental hygienist. This experience the symptom' pain is vanished after the work and reduced when go out the office and building, respectively. The ratio of the experience the symptoms and starting time the symptoms is anywhere from 12 noon to 4 pm (73.2%) in a day. The time of acute pain the symptoms is anywhere from 12 noon to 4 pm (78.7%) refer to the individual characteristics and work environment.

• Korean Journal of Occupational Health Nursing
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• v.14 no.2
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• pp.164-170
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• 2005

Purpose: The present study attempted to find subjective musculoskeletal symptoms of operating room nurses (OR nurses) and then to use them as basic data for prevention and management of musculoskeletal symptoms of OR nurses. Method: This study was an exploratory research, and data were collected from OR nurses working in 8 polyclinics in Korea from July 26 to August 19, 2004, using a self-report questionnaire. The questionnaire contains items concerned with subjective musculoskeletal symptoms include ones with the presence of symptoms and with the degree of discomfort, in the joints such as neck, shoulder, arm/elbow, hand/wrist/finger and waist. For data collection, the aim of the study was explained to the operating room managers to obtain their help, and these questionnaires were sent to hospitals, and were retrieved by post. 271(90.3%) questionnaires were returned among those sent to 300 nurses. 249 questionnaires excluding 22 insufficient ones such as no response were used for data analysis. Data were analyzed using SPSS WIN 12.0. Subjective musculoskeletal symptoms were analyzed in the number and percentage. Result: 187(75.1%) nurses said they 'had' subjective musculoskeletal symptoms and 62 (24.9%) said they had 'nothing'. 130(52.2%), 125 (50.2%), 113 (45.4%), 86(34.5%), and 42 (16.9%) nurses had subjective musculoskeletal symptoms in waist, shoulder, hand/wrist/finger, neck, and arm/elbow, respectively. 51(27.3%) and 136 (72.7%) nurses complained of the pain in one site, and in two or more sites, respectively. In particular, 51% and 47.4% nurses said that they were 'discomforted' due to the pain in waist and in shoulder, respectively. Conclusion: Subjective musculoskeletal symptoms which OR nurses complained of were significant. This may cause difficulty in nursing tasks in the operating room. So various arrangements have to be made for OR nurse with subjective musculoskeletal symptoms at an early stage.

• International Journal of Contents
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• v.12 no.1
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• pp.44-48
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• 2016

Driver fatigue is a major cause of fatal road accidents and has significant implications in road safety. In recent years, researchers have investigated steering wheel grip force as an alternative method to detect driver fatigue noninvasively and in real time. In this study, a fatigue detection system was developed by monitoring the grip force and changes in the grip force were measured while participants' engaged in an interactive simulated driving task. The study also measured the participants' subjective sleepiness to ensure the validity of measuring grip force. The results indicated that while participants engaged in a driving task, steering wheel grip force decreased and subjective sleepiness increased concurrently over time. The possible applications of the driver fatigue detection system by steering wheel grip force and future guidelines are discussed.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.498-506
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• 2021

This study identified the relationship between perceived mother-grandmother conflicts and subjective well-being among multicultural children, and examined the double mediating model of acculturative stress and adjustment to school life on that relationship. Participants were 205 male and female adolescents living at J county in Gangwon-do. PROCESS Macro 3.5 Model 6 was used for analysis of a double mediating effect. Results revealed that perceived mother-grandmother conflicts was positively correlated with acculturative stress of multicultural children, and negatively correlated with adjustment to school life and subjective well-being. And, acculturative stress of multicultural children was negatively correlated with adjustment to school life and subjective well-being, whereas adjustment to school life was positively correlated with subjective well-being. This study found that acculturative stress and adjustment to school life were sequentially mediating perceived mother-grandmother conflicts and subjective well-being of multicultural children. These findings suggest that the perceived mother-grandmother conflicts might cause multicultural children to experience acculturative stress, and as a result, their subjective well-being level might be reduced due to their low adjustment to school life.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.147-153
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• 2022

The uncertainty of start-ups are factors that weaken the entrepreneurial intentions of college students and prospective founders, and are also the cause of the low rate of entrepreneurship among art college students. This study tried to identify the effect of subjective norms entrepreneurial efficacy on start-up intentions. Studies have shown that entrepreneurial efficacy and subjective norms have a significant impact on start-up intentions. In addition, start-up education support has been shown to control the impact of subjective norms on start-up intentions, and start-up activity support has been shown to control the impact of subjective norms on start-up intentions, while start-up commercialization support does not control the impact of start-up efficacy or subjective norms on start-up intentions. In order to revitalize the start-up and effectively guide the start-up of art college students, it is necessary to show the social support of the people around them for the start-up and to enhance the efficacy of the start-up by supporting the prototyping activities.

• Research in Community and Public Health Nursing
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• v.16 no.3
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• pp.351-359
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• 2005

Purpose: To find the factors of subjective musculoskeletal symptoms associated with the general characteristics and tasks of operating room nurses (OR nurses) and then to use the factors as basic information for preventing and managing musculoskeletal symptoms in OR nurses. Method: This study was an exploratory research. Data were collected using a self-report questionnaire from OR nurses working at 8 polyclinics in Korea during the period from July 26 2004 to August 19 2004. The questionnaire contains 7 questions on general characteristics and 18 questions on tasks in the operating room. Result: 187 (75.1%) nurses said they 'had' subjective musculoskeletal symptoms. Statistically significant differences were observed according to clinical career, career as an OR nurse, skillfulness, satisfaction with tasks in the operating room, perception on suitable treatment, care of symptoms by the hospital. weight of hospital linen and weight of a basic operation set (p<.05). Conclusion: Musculoskeletal symptoms complained of by OR nurses were significant. This may cause difficulties in nursing tasks in the operating room. Thus, various arrangements should be made for OR nurse with subjective musculoskeletal symptoms at the early stage.