• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.369-376
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• 2007

With the convergence of ubiquitous networking and medical technologies, ubiquitous healthcare(U-Healthcare) service has come in our life, which enables a patient to receive medical services at anytime and anywhere. In the u-Healthcare environment, intelligent real-time biosignal aquisition/analysis techniques are inevitable. In this study, we propose a motion artifact cancelation method in portable photoplethysmography(PPG) signal aquisition using an accelerometer and an adaptive filter. A preliminary experiment represented that the component of the pedestrian motion artifact can be found under 5Hz in the spectral analysis. Therefore, we collected PPG signals under both simulated conditions with a motor that generates circular motion with uniform velocity (from 1 to 5Hz) and a real walking condition. We then reduced the motion artifact using a recursive least square adaptive filter which takes the accelerometer output as a noise reference. The results showed that the adaptive filter can remove the motion artifact effectively and recover peak points in PPG signals, which represents our method can be useful to detect heart rate in real walking condition.

• The Journal of the Korea Contents Association
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• v.17 no.8
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• pp.483-489
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• 2017

The purpose of this study is to analyze the catchment area of child care centers, which are becoming increasingly important due to social changes such as nuclear family and women's participation in society. In this study, we surveyed 2,174 children in 32 municipal child care centers in Suwon city. As a result, most of infants(0~2years old) were coming to daycare facilities by cars, and its catchment area for 90%ile were about 3km. Next, the catchment area of the children who walk to child care centers is about 500m. When using the car, the catchment area was 1.3km. This study provides the following suggestions. Considering the infant car use area, it is necessary to install more than one child care center per living area. In particular, there is a need to urgently expand daycare centers that provide child care services for infant care. Next, a nursing center-based pedestrian environment improvement project is needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6676-6684
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• 2014

This paper analyzed an existing literature review of street environment, density, accessibility, and diversity in terms of not the street level, but also the urban context level. In addition, this paper examined Jane Jacobs' theory (1961) regarding the relevance between the diversity of facilities and increasing volume of pedestrians. To find the explanation ability and significance among variables, this paper employed Enter's method of Regression Analysis in the industrial classification of restaurant business and liquor business. This empirical analysis of both theories of Jacobs (1961) and MacCormac (1983) had a different signification from existing research. Jacobs (1961) suggested the relevance among various facilities for increasing the volume of pedestrians, and MacCormac (1983) explained the different impact by industrial classification. In future research, the subdividing of industrial classification is necessary for a more precise and specific analysis.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.515-528
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• 1995

Slips and falls are the major causes of the pedestrian injuries in the industry and the general community throughout the world. With the awareness of these problems, the friction coefficients of the interface between floorings and footwear have been measured for the evaluation of slip resistant properties. During this measurement process, the surface texture has been shown to be substantially effective to the friction mechanism between shoe heels and floor surfaces under various types of walking environment. Roughness, either of the floor surface or shoe heels, provides the necessary drainage spaces. This roughness can be designed into the shoe heel but this is inadequate in some cases, especially a wear. Therefore, it is essential that the proper roughness for the floor surface coverings should be provided. The phenomena that observed at the interface between a sliding elastomer and a rigid contaminated floor surface are very diverse and combined mechanisms. Besides, the real surface geometry is quite complicate and the characteristics of both mating surfaces are continuously changing in the process of running-in so that a finite number of surface parameters can not provide a proper description of the complex and peculiar shoe - floor contact sliding mechanism. It is hypothesised that the interface topography changes are mainly occurred in the shoe heel surfaces, because the general property of the shoe is soft in the face of hardness compared with the floor materials This point can be idealized as sliding of a soft shoe heel over an array of wedge-shaped hard asperities of floor surface. Therefore, it is considered that a modelling for shoe - floor contact sliding mechanism is mainly depended upon the surface topography of the floor counterforce. With the model development, several surface parameters were measured and tested to choose the best describing surface parameters. As the result, the asperity peak density (APD) of the floor surface was developed as one of the best describing parameters to explain the ambiguous shoe - floor interface friction mechanism. It is concluded that the floor surface should be continuously monitored with the suitable surface parameters and kept the proper level of roughness to maintain the footwear slip resistance. This result can be applied to the initial stage of design for the floor coverings.

• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.93-101
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• 2011

In 2008, Korea has observed total 215,822traffic accidents Although the number has decreased since then, the crash rate is still higher than those of other advanced countries. In particular, high rate of pedestrian accidents occurred on urban streets is recognized as a serious problem. The previous studies, however, are not entirely considerate of accident factors by accident type. Inspired by the fact, this study analyzes factors affecting traffic accident by accident type. Using the accident data collected on urban streets in Seodaemun-gu, this paper classifies the accidents into two groups (i.e., vehicle-vs-vehicle and vehicle-vs-person crashes), and analyzes relationships between severity and exogenous variables. For the analysis, Structural Equation Modeling (SEM) is employed to estimate relationships among exogenous factors of traffic accident by each type on urban streets. The resulting model reveals that roadway related factors are highly correlated with the severity of vehicle-vs-vehicle crashes whereas environment factors are with vehicle-vs-person crashes.

• Journal of Forest and Environmental Science
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• v.34 no.2
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• pp.176-179
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• 2018

To restore the connectivity of fragmented habitats, 415 wildlife crossings have been built between 1998 and 2014 in South Korea. However, their effect on wildlife conservation is still in doubt. As a first step to examine the effectiveness, our study aims to assess compliance with the guideline for wildlife crossing construction and management, developed by the Ministry of Environment Korea that provides fundamental information to understand the status and the problem of wildlife crossings in Korea and thus to provide practical guidance for the improvement. According to our survey, the Korea National Park Service complied with the guideline best (62.5%) while local government followed the guideline least (46.1%). In addition, the compliance rate was the highest for wildlife crossings in national roads (53.6%) followed by highways (53.2%) and local and municipal roads (52.2%). For the overpass wildlife crossings, the compliance rates for installation of an escaping facility in the drainage and prevention of pedestrian and vehicle access were particularly low. In case of underpass wildlife crossings, small ditches for amphibians and reptiles were not sufficient, and the linkage between wildlife fences and underpass were weak. In order to ensure the effectiveness of wildlife crossings, the effort to increase the compliance rate with the guideline is critical, and mandating the guideline could be a practical way to enforce the compliance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.36-54
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• 2017

The purpose of this paper is to develop a multi-sensor fusion-based traffic information acquisition system with robust to environmental changes. it combines the characteristics of each sensor and is more robust to the environmental changes than the video detector. Moreover, it is not affected by the time of day and night, and has less maintenance cost than the inductive-loop traffic detector. This is accomplished by synthesizing object tracking informations based on a radar, vehicle classification informations based on a video detector and reliable object detections of a infrared range finder. To prove the effectiveness of the proposed system, I conducted experiments for 6 hours over 5 days of the daytime and early evening on the pedestrian - accessible road. According to the experimental results, it has 88.7% classification accuracy and 95.5% vehicle detection rate. If the parameters of this system is optimized to adapt to the experimental environment changes, it is expected that it will contribute to the advancement of ITS.

• Wind and Structures
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• v.22 no.4
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• pp.455-476
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• 2016

In both structural and environmental wind engineering, the vertical variation of wind direction is important as it impacts both the torsional response of the high-rise building and the pedestrian level wind environment. In order to systematically investigate the vertical variation of wind directions (i.e., the so-called 'twist effect') induced by hills with idealized geometries, a series of wind-tunnel tests was conducted. The length-to-width aspect ratios of the hill models were 1/3, 1/2, 1, 2 and 3, and the measurements of both wind speeds and directions were taken on a three-dimensional grid system. From the wind-tunnel tests, it has been found that the direction changes and most prominent at the half height of the hill. On the other hand, the characteristic length of the direction change, has been found to increase when moving from the windward zone into the wake. Based on the wind-tunnel measurements, a descriptive model is proposed to calculate both the horizontal and vertical variations of wind directions. Preliminarily validated against the wind-tunnel measurements, the proposed model has been found to be acceptable to describe the direction changes induced by an idealized hill with an aspect ratio close to 1. For the hills with aspect ratios less than 1, while the description of the vertical variation is still valid, the horizontal description proposed by the model has been found unfit.

• Korean Journal of Health Education and Promotion
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• v.11 no.2
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• pp.18-32
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• 1994

The purpose of this study was to analyze the effectiveness of injury prevention education on elementary school students. We are selected two elementary school in Tejeon, one was intervention school, the other was control school. Surveys were completed before the begining of the interventions in February in 1994 and again after their completion in July 1994. Intervention group was 284 students in pre-test and 218 students in post-test. And control group was 253 students in pre-test and 208 students in post-test. The results of this study was followed. 1. In the general characteristics of subjects studied, sex, mother education, father education, economic status, number of household, and traffic environment were not significant difference between intervention and control group(p>0.05). 2. The contents of injury prevention education that subjects wished to learn, were not significant difference between intervention and control group(p>0.05). Also the mothods of that were significant difference between intervention and control group in pre-test(p<0.05) but not in post-test(p>0.05). 3. Education in knowledge, attitude and practice of injury prevention was slightly effectiveness. Change in attitude of injury prevention was higher than in knowledge and attitude of that we guess that they require a lot of education in the pedestrian prevention. 4. Reative risk between intervention and control group in injury incidence was 1.53 in hospital-care students, and 1.43 in home-care children. Also relative risk of total injury incidence was 1.38, therefore we knew that injury incidence after education was reduced. 5. In the analysis of injury causes, pedestrain injury was remarkably reduced at hospital-care students in two group. At home-care students, two groups were high proportion in play injury. 6. In the analysis of injury places, intervention group was high proportion at near-the house in pre-test(35.4%) and at school in post-test(36.4%). And control group was high at inside-the house in pre-test(31.5%) and at near-the house in post-test(28.2%).

• Atmosphere
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• v.26 no.3
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• pp.445-459
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• 2016

Air temperature deviation (ATD) is one of major indicators to represent spatial distribution of urban heat island (UHI), which is induced from the urbanization. The purpose of this study is to evaluate the accuracy of air temperature deviation about Climate Analysis Seoul (CAS) workbench, which had developed by National Institute Meteorological Science and TU Berlin. Comparison and correlation analysis for CAS ATD including meso-scale air temperature deviation, local-scale air temperature deviation, total air temperature deviation, surface heat flux deviation, cold air production deviation among meso-scale numerical modelling variable in 'Seoul Region', micro-scale numerical modelling in 'Detail Region', and CAS workbench variable using observation data in ground stations. Comparison between night time OBS ATD and CAS ATD show that have most close values. Most of observations ($dT_{max}$ and $dT_{min}$) have highly positive ($dT_{SHP}$, $dT_{CA}$, MD, TD, $f_{BS}$, $f_{US}$, $f_{WS}$, $h_B$) and negative ($f_{VS}$, $f_{TV}$, $h_V$, Z) correlations. However, CAS workbench needs further improvement of both observational framework and analytical framework to resolve the problems; (1) night time OBS ATD of has closer values in compare with at high rise mountain area and (2) correlations are very dependable to meteorological scale.