• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.427-427
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• 2015

The storm water management and drainage relation are the key variable that plays a vital role on hydrological design and risk analysis. These require knowledge about spatial variability over a specified area. Generally, design rainfall values are expressed from the fixed point rainfall, which is depth at a specific location. Concurrently, determine the areal rainfall amount is also very important. Therefore, a spatial rainfall interpolation (point rainfall converting to areal rainfall) can be solved by areal reduction factor (ARF) estimation. In mainland of South Korea, for dam design and its operation, public safety, other surface water projects concerned about ARF for extreme hydrological events. In spite of the long term average rainfall (2,061 mm) and increasing extreme rainfall events, ARF estimation is also essential for Jeju Island's water control structures. To meet up this purpose, five fixed rainfall stations of automatic weather stations (AWS) near the "Hancheon Stream Watershed" area has been considered and more than 50 years of high quality rainfall data have been analyzed for estimating design rainfall. The relationship approach for the 24 hour design storm is assessed based on ARF. Furthermore, this presentation will provide an outline of ARF standards that can be used to assist the decision makers and water resources engineers for other streams of Jeju Island.

• Journal of environmental and Sanitary engineering
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• v.21 no.4 s.62
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• pp.19-28
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• 2006

The purpose of this study was to investigate the related factor for the prevalence of musculoskeletal symptoms among 212 sewing worker. The survey was performed with self-administered questionnaire for the risk factors related to musculoskeletal disorders(MSDs) from August 5 to 7 in 2005. The prevalence of musculoskeletal symptoms were 75.8% and the those of the local symptoms were 71.7 % for shoulder, 60.4 % for neck, 35.8 % for arm and 50.9 % for wrist. The risk factors related the self-reported MSDs had not shown in general characteristics. But, there was a significant difference between daily working hour and wrist, working speed and neck, the degree of satisfaction and wrist for work related factor. Also, it was shown the significant difference between chair height and neck, the height of sewing machine and wrist among the space below work station, neck, waist for the prevalence of musculoskeletal symptoms. The significant correlation was shown for daily working hour and wrist, working speed and arm, work load and shoulder and the degree of satisfaction and arm for work related subjective symptom. Considering above results, it is suggested the ergonomic design be provided to working hour, the height of chair and work station as well as daily working hour even there is a significant difference for the prevalence of symptoms in each body part for sewing workers.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.1
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• pp.19-30
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• 2021

This research studied the effect of visual improvement of "72 Hour Project" that has regenerated small scale derelict spaces in Seoul through citizen participation. 29 projects built form 2016 to 2019 were analyzed. The research analyzed landscape image preference of before and after status of projects using 12 pairs of landscape adjectives. Basic statistical analysis, correlation analysis, factor analysis, cluster analysis, and ANOVA were performed based on the survey results. Since the satisfaction level of the projects compared with the before-condition was 3.63 higher than 3.00, it could be concluded that there was an meaningful effect of visual improvement after completion of the projects. As the result of the factor analysis, landscape adjective pairs were categorized into two factors: harmony and aesthetics. Through the cluster analysis, four clusters were formed and characteristics of each cluster were identified. As the result of rhe cluster analysis, the cluster with the high harmony level and the aesthetics level showed the highest overall satisfaction level. Comparing each cluster, it could be concluded that the factor of harmony was more important than the factor of aesthetics in evaluating the satisfaction level of projects. Analyzing qualitative aspects of project groups, spatially well-balanced design with generous vegetation areas was more effective in landscape improvement than artistic design with visually strong installations. Further researches based on behavior studies of actual users are required to compensate the limits of this research. This research can contribute to establish the improved direction of policies to regenerate various types of small scale derelict spaces.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.385-397
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• 2002

Objectives: This study was to investigate the experience and a Point prevalence rate and factors related with Low Back Pain (LBP) in instructors of drive institute. Methods: Questionnaires were completed by 174 instructors who worked at 13 drive institutes in 4 small cities from June 2002. The information was used to estimate odds ratio (OR) and 95$\%$ confidence intervals (CI) for factors relation to LBP. A retrospective study design was used. Results: The experience rate for LBP was 57.2$\%$, 43.4$\%$ in one year interval prevalence, 42.2$\%$ in 6 months interval prevalence, and 35.8$\%$ in a point prevalence rate. Factor significantly associated with LBP experience by logistic regression was labour hour (p=0.0034), subjects who worked for long hours a day were higher than those who did not (OR=3.8, 95$\%$ CI 1.4-5.6). Conclusions: In conclusion, labour hour was significantly associated with LBP experience.

• Journal of Radiation Protection and Research
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• v.28 no.2
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• pp.127-135
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• 2003

The primary contributors to the total occupational radiation exposure in operating nuclear power plants are operation and maintenance activities doting refueling outages. The Advanced Power Reactor 1400 (APR1400) includes a number of design improvements and plans to utilize advanced maintenance methods and robotics to minimize the annual collective dose. The major radiation exposure reduction features implemented in APR1400 are a permanent refueling pool seal, quick opening transfer tube blind flange, improved hydrogen peroxide injection at shutdown, improved permanent steam generator work platforms, and more effective temporary shielding. The estimated average annual occupational radiation exposure for APR1400 based on the reference plant experience and an engineering judgment is determined to be in the order of 0.4 man-Sv, which is well within the design goal of 1 man-Sv. The basis of this average annual occupational radiation exposure estimation is an eighteen (18) month fuel cycle with maintenance performed to steam generators and reactor coolant pumps during refueling outage. The outage duration is assumed to be 28 days. The outage work is to be performed on a 24 hour per day basis, seven (7) days a week with overlapping twelve (12) hour work shifts. The occupational radiation exposure for APR1400 is also determined by an alternate method which consists of estimating radiation exposures expected for the major activities during the refueling outage. The major outage activities that cause the majority of the total radiation exposure during refueling outage such as fuel handling, reactor coolant pump maintenance, steam generator inspection and maintenance, reactor vessel head area maintenance, decontamination, and ICI & instrumentation maintenance activities are evaluated at a task level. The calculated value using this method is in close agreement with the value of 0.4 man-Sv, that has been determined based on the experience aid engineering judgement. Therefore, with the As Low As Reasonably Achievable (ALARA) advanced design features incorporated in the design, APR1400 design is to meet its design goal with sufficient margin, that is, more than a factor of two (2), if operated on art eighteen (18) month fuel cycle.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.4
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• pp.185-192
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• 2005

This paper proposes a DRMS(Distribution Remote Management System) which can enhance highly the economics of automatic metering system and the power quality supplied to the electric customer improving the efficiency of the meter reading, voltage management and load management work by realizing the remote meter reading, the remote voltage management and the remote load management based on the ADWHM(Advanced Digital Watt Hour Meter). The DRMS is designed so that the voltage management and load management work in remote site can be processed by collecting the voltage pattern and current pattern as well as watt hour data from all ADWHMs one time every month regularly or from special ADWHMS several time irregularly, A new on-line voltage and load management strategy based on the ADWHM is designed by analyzing the existing voltage management and load management process. Also, DRMS is designed so that watt-hour data, voltage pattern data, load pattern data and power factor data can be collected selectively according to the selection of user to assist effectively the methodology. Remote management program and database of the DRMS are implemented based on Visual C++, MFC and database library of MS. Also, DRMS is designed so as to communicate with the ADWHM using RS232C-TCP/IP converter and ADSL. The effectiveness of the remote metering function is proven by collecting and analyzing the data after ADWHMs installed in any site. The developed strategy and program also is verified through the simulation of voltage management and load management.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.11
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• pp.995-1000
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• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.92-97
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• 2007

A temporary structure is a framework of metal poles and planks, used as a working platform from which building repairs or construction can be carried out safety. The manufacturing process of the existing model consumes a many hour. So, it is modified manufacturing process. In this study, it is attempted to find out the shape of modified working platform considering manufacturing process and using Taguchi method, and it reduces production process. The design parameters are defined to discribe shape of model. As a result of the shape design, maximum Von-Mises stress and displacement considering a safety factor were satisfied with CTEA (Construction Temporary Equipment Association of Korea) standard.

• The Journal of Natural Sciences
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• v.15 no.1
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• pp.111-125
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• 2005

This study aims at reconsidering the spacial structure and suggesting guidelines for campus planning and design with spatial reference to the Campus of PaiChai university, area $208,499m^2$, Taejon. This study is mainly based on user's behavior and physical traces and questionnaire survey. User's behavior and physical traces were carefully observed by 20 students of dept. of landscape architecture at each alloted zone, 6 zones in Campus. Questionnaire survey, consisted of user attitudes, use satisfaction factors and personal items was carried out to 320 persons. As a result, the item of 'rest' shows the highest mean and the item of 'chatting' and 'meeting' follows to utilization purpose. The length of stay is generally 30minute to 1hour. The factor analysis, on the object of 32 items except 4 item, appeared 8 factors: visual elements, activity, vehicle, plants, practicality of street furniture, bench, spacial use and shade.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.43-52
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• 2005

Highway classification is an essential part of defining design criteria of roads. This study is to classify highways by factor analysis. To accomplish the objectives, factor analysis is performed for classifying highways using the traffic data observed at the permanent traffic count points in 2004. A total off variables are applied : AADT, K factor, D factor, heavy vehicle proportion, day time traffic volume proportion, peak hour volume proportion, sunday factor, vacation factor and COV(Coefficient of Variation). The results of factor analysis show that variables are divided into two factors, which are the factor related to the fluctuational characteristics of traffic volume and the factor related to heavy vehicle and directional volume characteristics. According to the results of cluster analysis, 353 permanent traffic count points are categorized into such three groups as type I for urban highway, type II for rural highway, type III for recreational highway, respectively.