• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.4
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• pp.42-50
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• 2000

Drop size distribution of an air-assisted fuel injector(AAFI) was investigated. Influence of parameters such as ambient air density supply pressure and air-liquid mass ratio(ALR) was examined through both measurement and analysis. The Sauter mean diameter$D_{32}$ varied from 9 to 25$\mu$m throughout all experimental conditions. An empirical correlation for droplet size was obtained. Analytical correlations for predicting $D_{32}$ with respect to operating conditions were also derived through energy consideration and introduction of a simplified model of the from the empirical fitting was adapted to the original equation the proposed correlation in this study matched more closely with measured results. The current correlation exhibited a favorable study matched more closely with measured results. The current correlation exhibited a favorable prediction for $D_{32}$ compared to that by the empirical correlation at selected experimental conditions so that it may be used to predict atomization performance of the AAFI at operating conditions which was not covered in the measurements. After validation the analytical equation was applied to survey the feasible operating conditions for gasoline direct injection application.

• KSBB Journal
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• v.16 no.5
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• pp.511-515
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• 2001

In this paper, we development and operated a two-stage continuous stirred tank reactor (CSTR)/trickling biofilter(TBF)system for the long-term continuous treatment of trichloroethylene (TCE) using Burkholderia cepacia G4. In this reactor system. CDTR with cell recycle from TBF was coupled to the TBF for the reactivation of the cells deactivated during TCE degradation. The critical elimination capacity was determined to be 25.3 mg TCE/L day and the reactor has been stably operated for more than 1 months, which clearly represented that CSTR/TBF system can be used for long-term treatment of TCE.

• Tunnel and Underground Space
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• v.17 no.5
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• pp.337-349
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• 2007

Yearly, it seems the fact that the numbers of tunnels with wide sections are on the rise as the length of tunnel and number of lanes continues increasing. According to these trends, well-schemed plans of design, construction and management related with tunnel safety has become to be crucial. It is a high possibility to be observed by the fact that the direct effects of casualties and property damages are caused by the situations of car collisions, bump to solid structures by careless driving and the outbreak on vehicles by mechanical fault. Therefore, in order to prevent these types of accidents, we would make issues md adopt appropriate mechanical and management plans of emergency exits and disaster prevention equipments inside of tunnel, based on up-to dated experiences and study of foreign cases, to structural design technology. The objectives of this study are to recognize related actual problems and suggest improvement plans.

• Physical Therapy Korea
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• v.4 no.2
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• pp.18-35
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• 1997

The purpose of this study were to determine causes of low back pain in bus drivers who usually work in prolonged sitting position and to find the relationship of back pain with general characteristics and work environmental characteristics, stress symptoms, to com맹re lordosis angle of habitual driving posture and resting posture in low back pain group and non-low back pain group, and to use this result as a basis for improvement of work environment and comprehensive rehabilitative management of low back pain. Ninety-eight bus drivers were selected from the membership of an urban transit union in Seoul. These informations were collected from May 1, 1997 to May 25, 1997 by means of structured questionnaires and X-ray findings. These data were analyzed by $x^2$ test, t-test, logistic regression using SAS. The major results were as follows: 1. Of the respondents, 66.3% of bus drivers were found to be experiencing back pain. 2. Of the respondents of low back pain groups, 78.5% reported that major cause of low back pain was due to prolonged sitting. 3. The group with experiences of frequent or continuous vibration had more low back pain (p<0.05). There were no significant differences among other work environmental factors. 4. Average stress score was significantly higher in the group with low back pain than in the group without low back pain (p<0.05). 5. The results of the logistic regression analyses were statistically significant vibration from seat and stress score among the risk factors (p<0.05). 6. Averaged lordosis angle of habitual driving posture was $7.6{\pm}14.9$ degrees in low back pain group, $16.5{\pm}8.7$ degrees in non-low back pain and averaged lordosis angle of resting sitting posture was $10.8{\pm}13.7$ degrees in low back pain, $18.9{\pm}9.6$ degrees in non-low back pain group but the difference in mean lordosis angles of two groups was not statistically significant. The results of this study indicate that professional drivers developed chronicity of low back pain due to unfit seat, poor habitual posture and stress from vibration or other risk factors. Therefore, there is need to improve work environment, i.e. enough resting, to set a seat to support lumbar spine properly and to provide comprehensive rehabilitation program including early diagnosis, proper treatment and education for self help management.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.159-165
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• 2022

The purpose of this study is to examine racism in the movie ≪Green Book≫ and to find solutions to racism through discussion with students. Set in 1962 in the United States, this film depicts the process of forming a good bond with the black pianist Dr. Shirley and the driver Tony in a racist society. This study utilized the subject of race, one of the subjects covered in the humanities class in the global era of S University in the second semester of 2021. This is because, since the outbreak of racism, the problem of racism has continued to arise in the current COVID-19 pandemic situation. Therefore, the researcher looked at racism and intercultural education as a theoretical background, and looked at cases of racism in movies and cases of racism that have occurred today. The history of racism and discrimination dates back to medieval Europe and was caused by religious conflicts and was attributed to white supremacy. As a solution to this racial discrimination, international organizations suggested intercultural education. And the reason why film was used in this study is because it aims to provoke students' interest and motivation for learning by targeting first-year university students called the digital native generation who were born and grew up with the Internet. In this study, students' solutions to racism were presented using discussion, and then the researcher's solutions were presented.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.428-432
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• 2015

Objectives: The purpose of this study was to research 'Daeri' drivers who work for drunken customers as a substitute driver. This was the first study in Korea to investigate assault and verbal abuse experienced while employed as a 'Daeri' driver. Methods: In this study, we conducted a survey to investigate people who work as 'Daeri' drivers. The survey was performed from September 1 to 7, 2014. The participants were 166 adult men and women who work as full-time 'Daeri' drivers. Results: Participants who experienced physical violence and assault from the customers to the point of disturbing safe driving in a year were 36.1% of total respondents. People who experienced verbal abuse to the point of disturbing safe driving in a year totaled 80.4% of respondents. In addition, there were also qualitative research results. Conclusions: Acts that impede safe driving are a danger to both passengers and drivers. By protecting the safety of 'Daeri' drivers, we will be able to protect the safety of citizens. Therefore, it is necessary to make an effort to protect 'Daeri' drivers from customer violence. Furthermore, it is also necessary to research policy to emplace a legal system that can protect 'Daeri' drivers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.260-264
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• 1981

The purpose of the present study is to measure the sound spectrum of the underwater noise generated by a stern trawler M/S Saebada (2,275 GT, 3600 ps) in the various operational conditions. Underwater noises were recorded by a hydrophone (B & K 8100) and analyses were made rising a digital frequency analyzer (B & K 2131) and level recorder (B & K 2370). The predominant frequency range was 100-500 Hz, and maximum sound pressure level was 121 dB(re. $1{\mu}Pa$). Underwater noise level increased with the increased speed of the vessel. Sound pressure level measured in the course of astern cruising was higher than that measured in the course of ahead cruising and also the noise spectrums were different in these two cases. At the time of cruising the underwater noise was higher than 10 dB compared to those values measured at the time at rest with only engine operation. The underwater noise of the vessel was mainly due to the main engine revolution of the propeller and the vibration of hull.

• The Journal of the Korea Contents Association
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• v.13 no.7
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• pp.248-264
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• 2013

This study analyzed the differences of the person-environment fit, work stress and work satisfaction according to a demographic factors of elderly people under participation in job activities. And this study analyzed the relationship of the effects on person-environment fit, work stress and work satisfaction as well as the moderating effects of self-efficacy. The survey was conducted from February 15 to March 20, 2013 among the male taxi drivers aged 60 or older in the Seoul areas, and 358 responses were used in the data analysis. As a results, there were partially differences in the person-environment fit, work stress and work satisfaction according to a demographic factors. The person-environment fit had a negative impact on work stress, but it had a positive impact on work satisfaction. In addition, the self-efficacy had a moderating effects in the relationship of the person-organization fit and work stress.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.421-426
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• 1999

Objectives: An outbreak of dermatosis occurred at a city gas manufacturing factory in Pohang in Aug, 1998. The authors conducted a study to find the cause and prevent the dermatosis, Methods: We conducted a questionnaire survey of 73 workers in the factory twice, once or Aug. 14th and then Sept. 11th, 1998. Also, a dermatologist examined their skin lesions. We suspected ants as the cause, so we collected them for identification. Results: Twelve cases of dermatosis were identified with an attack rate of 16.4%. The attack rates were not different by age, educational level or tenures. The attack rates were 66.6% among production workers, 2.0% among clerical workers, 16.7% among tank trailer drivers and 0% among guards. The attack rate among production workers was significantly higher than that of the others (<0.01). There were no histories of the same dermatosis for the past one year. Histories of other skin diseases and allergies were very rare in both cases with skin diseases and control. Multiple, pruritic, rice-grained to bean sized erythemafous macules or papules with a central biting point could be found after initial severe itching occurred, Three cases showed signs of dermatosis with an allergic nature. The onset of dermatosis was between July 30 and Aug 12 and the durations varied from 5 days to over a month. The most frequent sites of stir lesions were the chest and abdomen (60.6%), and they were also observed on the neck (33.3%), arms (33.3%), shoulders (16.7%) and back (16.7%). Over 10 ants with their wings were collected in the work place and identified as Pachycondyla chinensis, subfamily Ponerinae. Conclusions : We thought that the outbreak of dermatosis was brought about by the ants flying into the work place through the open windows. Further studies on the factors contributing to the prosperity of the ants in this area are needed.

• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.101-114
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• 2001

Transportation enterprises should maintain constant and qualitative operation. Thus, in short period, transportation enterprises don't change supply in accordance with demand. In the result, transportation enterprises don't reduce operation in spite of management deficit at will. In freight transportation type, less-than-truckload(LTL) has more relation with above transportation feature than truckload(TL) does. Because freight transportation supply of TL is more flexible than that of LTL in correspondence of freight transportation demand. Relating to above mention, it appears that shortage of road and freight terminal of LTL is larger than that of TL. Especially in road and freight terminal comparison, shortage of freight terminal is larger than that of road. Shortage of road is the largest in 1990, and improved after-ward. But shortage of freight terminal is serious lately. So freight terminal needs more expansion than road, and shows better investment condition than road. Freight terminal expansion brings road expansion in LTL, on the contrary, freight terminal expansion substitutes freight terminal for road in TL. In transportation revenue, freight terminal's contribution to LTL is larger than that to TL. However, when we adjust quasi-fixed factor - road and freight terminal - to optimal level in the long run, in TL, diseconomies of scale becomes large, but in LTL, economies of scale becomes large. Consequently, it is necessary for TL to make counterplans to activate management of small size enterprises and owner drivers. And LTL should make use of economies of scale by solving the problem, such as nonprofit route, excess of rental freight handling of office, insufficiency of freight terminal, shortage of driver, and unpreparedness of freight insurance.