• Journal of ILASS-Korea
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• v.8 no.2
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• pp.1-6
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• 2003

The liquid phase LPG injection (LPLI) system (the third generation technology) has been considered as one of the next generation fuel supply systems for LPG vehicles, since it has a very strong potential to accomplish the higher power, higher efficiency, and lower emission characteristics than the mixer type(the second generation technology) fuel supply system However. when a liquid LPG fuel is injected into the inlet duct of an engine, a large quantity of heat is extracted due to evaporation of fuel. This leads to freezing of the moisture in the air around the outlet of a nozzle, which is called icing phenomenon. It may cause damage to the outlet nozzle of an injector or inlet valve seat. In this work, the experimental investigation of the icing phenomenon was carried out The results showed that the icing phenomenon and process were mainly affected by humidity of inlet air instead of air temperature in the inlet duel. Also, it was observed that the total ice formed around the nozzle weighs at about $150mg{\sim}260mg$ after injection for ten minutes. And some fuel species were found in the ice attached at the front side of a nozzle, while frozen ice attached at the back of a nozzle was mostly' consisted of moisture of inlet air. Therefore, some frozen ice deposit. detached from front nozzle of an injector, may cause a problem of unfavorable air fuel ratio control in the small LPLI engine.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.221-230
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• 2008

We Studied current Flight Information System everyone employing, and this paper designed a next generation Ubiquitous Flight Information System. Studied a Ubiquitous Flight Information System regarding AVOD, game TV, cellular phone, cabin Internet use for a customer, and airline and control of Air Traffic Service, Air Traffic Control, in seat reservation, transportation, ticketing and luggage back-tracking and airplanes in earthly service. We Designed for a Next Generation Ubiquitous Flight Information System and for necessary for network security, system security of information security system, and derived from comparative analysis of improvement point and difference to existing Ubiquitous Flight Information System and Next Generation Ubiquitous Flight Information as was based on result of research. Present vision to aerial the result of research world of this paper related industry, and ensure safety and communication efficiency and a customer and flight satisfaction, efficiency, and will reclaim the new horizon to the Flight Information Industry.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1195-1200
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• 2008

This study have goal with conceptual design for Offshore Structures of high pressure control valve for localization. Ball valve for development accomplished with flow analysis based on provision of ANSI B16.34, ANSI B16.10, ANSI B16.25 In order to localize the Offshore Structures high pressure control valve. Numerical simulation using CFD(Computational Fluid Dynamic) in order to predict a mass flow rate and a flow coefficient form flow dynamic point of view. The working fluid assumed the glycerin($C_3H_8O_3$). The valve inlet and outlet setup a pressure boundary condition. The outlet pressure was fixed by atmospheric pressure and calculated until increasing 1bar to 10bar. CFD analysis used STAR-CCM+ which is commercial code and Governing equations were calculated by moving mesh which is rotated 90 degrees when ball valve operated opening and closing in 1 degree interval. The result shows change of mass flow rate according to opening and closing angle of valve. Flow decrease observed open valve that equal percentage flow paten which is general inclination of ball valve. Relation with flow and flow coefficient can not be proportional according to inlet pressure when compare with mass flow rate. Because flow coefficient have influence in flow and pressure difference. Namely, flow can be change even if it has same Cv value. The structural analysis used ANSYS which is a commercial code. Stress analysis result of internal pressure in valve showed lower than yield strength. This is expect to need more detail design and verification for stem and seat structure.

• Molecules and Cells
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• v.39 no.3
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• pp.250-257
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• 2016

Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.

• Journal of the Korean Society for Railway
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• v.13 no.6
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• pp.552-558
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• 2010

Ride comfort of railway vehicles is affected by many factors, such as vibration, noise, smell, temperature, visual stimuli, humidity and a seat design. In general, vibration, which originates from vehicle motion, is considered as the primary concern. In evaluating the ride comfort, relationship between passenger's feeling and vibration characteristics is very important because human feeling is dependent on frequency spectrum of vibration. Therefore, the weighing functions in frequency domain are used to evaluate the ride comfort of railway vehicles. In the present paper, we have analyzed the characteristics of the frequency weighting curves defined in many standards and reviewed the effect resulting from their difference on the ride comfort.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.659-669
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• 2011

Objective: The aim of this study is to suggest a package layout guideline for low-floor bus by interview with passengers and observations of their behavior. Background: Increasing attention has been introduced the low-floor bus to be more suitable for use by transportation handicapped. Complex issues are involved in providing comfortable services to all people. We are going to suggest package layout guidelines for more comfortable and suitable travel to all people. Method: The two times of survey and video observation sessions were conducted on low-floor buses in Seoul; (1) a finding of potential issues in the first session, (2) a confirming of issues from the last session. Results: The three of major issues were founded in this study; (1) difficulties in supporting body when standing, (2) difficulties in sitting on front wheel pan seat, (3) difficulties in passing through the aisle. Conclusion: There were clear differences between public and transportation handicapped in using some tools which are used for support body such as roof hand rails, side hand rails, and hand rail rings. Some of design problems were founded to improve from the perspective of ergonomics and universal design. Such differences and design guidelines have to be considered in bus design as well as commercial vehicle. Application: The proposed design guidelines can be used to development of low-floor bus and other public transportations.

• Journal of the Ergonomics Society of Korea
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• v.26 no.3
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• pp.81-89
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• 2007

The purpose of this study is to develop data base and interface for sofa consumers and sofa designers. The human sensibility ergonomics method was used to find the consumer needs and Quality Function Deployment (QFD) method was used to extract the designing characteristics required for sofa production. About 200 words and 100 images were gathered from sofa and furniture related catalogs and internet sites to find the best emotional words and images that can express the various sofa aspect. Among the collected words and images, 34 emotional words were selected for sensibility experiment according to the opinions of experts, relations of closeness and frequency of use, and 50 images were selected for the experiment by the diversity. Selected words and images were used for the semantic differential method with 94 subjects, and sensibility characteristics of sofas were defined through various statistical analysis methods including basic statistical analysis, factor analysis and multi-dimensional scale. In reflecting design characteristics of sofas, design factors of sofas were divided into backrest, seat, armrest, neck support and leg, and relative importance of each factor for design was determined with analytic hierarchy process (AHP) by utilizing the experts' opinions. Based on the results above, relationship analysis between emotional evaluation results and design factors was performed. Also, as various sofa images are presented diagrammatically through multidimensional scaling method, it can be used as an important tool for the development of sofa design. This study will contribute improving the product quality of sofas as it enables applying consumer needs into the sofa design.

• Korean Journal of Occupational Health Nursing
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• v.23 no.1
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• pp.20-27
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• 2014

Purpose: This study was conducted to identify the association between emotional labor and job stress in bus drivers, as well as to propose management strategies for job stress. Methods: The study was conducted in February 2013 and involved 182 bus drivers working in the Gyeonggi area. Results: emotional labor was $9.5{\pm}2.34$ on average, and job stress was higher than the median of the same indicator among Korea's workers in the areas of physical environment, job autonomy, and relationship conflicts. Factors that affected job stress was lower if the subjects' Higher values for emotional labor indicated a higher level of job stress. Conclusion: To reduce among drivers, the following measures are necessary: increase the comfort of the driver's seat within the vehicle, provide adequate rest between bus headways, provide comfortable in-house rest facilities, and establish physical training spaces to reduce musculoskeletal disorders as well as programs for reducing back pain. In addition, relationship conflicts may be relieved by increasing job autonomy as much as possible, by granting autonomous control of working hours and bus headways, as well as by banning long work hours. Moreover, various club activities, exercise programs, and counseling programs that workers can be involved in together may be beneficial. This study is significant in that it identified the relationship of the bus drivers' emotional labor and job stress, which has previously been ignored as a research topic. Through its results, this study provides baseline data for the preparation of management strategies that can address the job stress of bus drivers.

• Korean Journal of Health Education and Promotion
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• v.26 no.4
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• pp.49-62
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• 2009

Objectives: Few studies have focused on health behaviors and health status among teachers even though these are one of principles and values of WHO's Health Promoting Schools. In this study, we described health behaviors and health status among teachers and explored the differences of these by personal and school characteristics. Methods: A stratified and random cluster sampling design was used to obtain a cross-sectional sample. A total of 59 elementary, middle and high schools in Seoul and Gyeonggi areas were included in which 333 teachers (males 40.6%, females 59.4%) participated in this survey. Chi-square tests were conducted with SPSS 17.1. Results: Overall, health behaviors and health status among teachers were better than the general public according to Korea National Health and Nutrition Examination Survey. Male and middle/high school teachers had higher prevalence of alcohol dependence and of driving under the influence of alcohol. Also, their rate of wearing seat belts were lower compare to female. In other hand, female, health and nutrition teachers, rural school teachers had lower prevalence of meeting recommended levels of physical activity. Underweight were more prevalent to them in contrast to male with higher prevalence of obesity. In addition, teachers of health promoting schools were not likely to ride on a car with a drunk driver. They also have a lower prevalence of skipping breakfast and have higher positive perception of health for themselves. Conclusion: Teachers' health should be given higher concerns as a key component of school based health promotion. Gender and age specific programs should be considered to develop health promoting programs for them.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.6
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• pp.967-975
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• 2010

There have been a lot of efforts on the improvement for the ride comfort and handling stability of the combat vehicles. Especially most of vehicles for military purpose have bad inertial condition and severe operating condition such as the rough road driving, and need a high mobility in the emergency status. It is necessary to apply the controlled suspension system in order to improve the vehicle mobile stability and ride comfort ability of crews. A feasibility study is performed on the application of the semi-active suspension system with a magneto-rheological controlled shock absorber for a $6{\times}6$ combat vehicle. First, the dynamic simulation model of the vehicle including the control model for the semi-active suspension system was executed. Based on this model, a hardware-in-the-loop simulation(HILS) system which has a semi-active suspension controller hardware was constructed. After full vehicle simulations were performed in virtual proving courses with this system, the semi-active suspension system was proven to give better ride comfort and handling stability in comparison with the conventional passive suspension system.