• Title/Summary/Keyword: Visibility Analysis

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Analysis of Traffic Crash Severity on Freeway Using Hierarchical Binomial Logistic Model (계층 이항 로지스틱모형에 의한 고속도로 교통사고 심각도 분석)

  • Mun, Sung-Ra;Lee, Young-Ihn
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.199-209
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    • 2011
  • In the study of traffic safety, the analysis on factors affecting crash severity and the understanding about their relationship is important to be planning and execute to improve safety of road and traffic facilities. The purpose of this study is to develop a hierarchical binomial logistic model to identify the significant factors affecting fatal injuries and vehicle damages of traffic crashes on freeway. Two models on death and total vehicle damage are developed. The hierarchical structure of response variable is composed of two level, crash-occupant and crash-vehicle. As a result, we have gotten the crash-level random effect from these hierarchical structure as well as the fixed effect of covariates, namely odds ratio. The crash on the main line and in-out section have greater damage than other facilities. Injuries and vehicle damages are severe in case of traffic violations, centerline invasion and speeding. Also, collision crash and fire occurrence is more severe damaged than other crash types. The surrounding environment of surface conditions by climate and visibility conditions by day and night is a significant factor on crash occurrence. On the orher hand, the geometric condition of road isn't.

Finding Smartphone's Factors which Affect Satisfaction or Dissatisfaction based on KANO Model (KANO 모델을 활용한 스마트폰의 만족 및 불만족 요인 분석)

  • Lee, Sang-Gun;Lee, Sin-Seok;Kang, Ju-Young
    • The Journal of Information Systems
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    • v.20 no.3
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    • pp.257-277
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    • 2011
  • The current study categorizes factors of smartphone into three, using KANO model: attractive factors which cause only product satisfaction, must-be factors for dissatisfaction, and one-dimensional factors for both. Based on it, it presents a new model for the effects that smartphone factors have on satisfaction or dissatisfaction. The purpose is to theoretically explain that smartphone factors on which companies and users place a high value can actually affect satisfaction or dissatisfaction. After choosing 15 factors out of 25 which had been selected through literature study, these were divided into attractive, must-be, and one-dimensional ones. 93 out of 109 questionnaires returned were used for analysis. After frequency analysis using SPSS were conducted on the surveys, the factors were grouped, based on KANO table. The grouping results are as follows. Attractive factors include 'expansion slots for external memory, battery desorption, brand awareness, mobile banking and internet telephony'. Must-be ones include 'multi-touch, information security, entertainment, information retrieval, location based service and SNS. Finally, 'screen visibility, size of internal memory, the amount of internal memory, battery life, and response to after-sales service' are classified as one-dimensional factors. A critical finding of this paper is that since the results are different depending on the operating system of smartphones, it must be taken into consideration in studies on smartphones. The wide and rapid spread of smartphones has changed people's lifestyle as well as business environment, which forces companies to compete with each other to adapt to the changed circumstances. In this competitive system, studies on smartphone factors of satisfaction and dissatisfaction are essential for firms to establish a new strategy. From this point of view, the present paper is expected to be a basic material for enterprises not only to develop goods and services that maximize customer satisfaction and minimize dissatisfaction, but also to establish the future business strategy.

A Study on the Crew's Survival ratio according to ship's structure (선박구조가 승무원 생존율에 미치는 영향에 대한 연구)

  • Kim, Won-Ouk
    • Journal of Navigation and Port Research
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    • v.34 no.6
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    • pp.423-427
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    • 2010
  • Land fire receives additional extinguishing methods easily by professional extinguisher. But because of isolation and independence from land when sailing on the sea, ships are difficult to get special help from land. Generally, the death ratio by suffocation is higher than the death rate by flame and to reduce suffocation death ratio, fast evacuation is required. This paper aims to improve survival ratio at ship fires by soot density reduction. This study examines soot density and visibility using FDS. And also examines evacuation time by Pathfinder. The FDS(Fire Dynamic Simulator) is a 3 zone model(Field Model) analysis tool and the patherfinder is a useful analysis tool for evacuation. This research examined about evacuation time using the current regulations of the ship's corridor width and exit width first. And then studied evacuation time again when ship's structure was changed according to the method that is proposed in this paper. And finally compared the results each other.

Analysis of a Simulated Optical GSO Survey Observation for the Effective Maintenance of the Catalogued Satellites and the Orbit Determination Strategy

  • Choi, Jin;Jo, Jung Hyun;Yim, Hong-Suh;Choi, Young-Jun;Son, Ju-Young;Park, Sun-youp;Bae, Young-Ho;Roh, Dong-Goo;Cho, Sungki
    • Journal of Astronomy and Space Sciences
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    • v.32 no.3
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    • pp.237-245
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    • 2015
  • A strategy is needed for a regional survey of geosynchronous orbits (GSOs) to monitor known space objects and detect uncataloged space objects. On the basis of the Inter-Agency Debris Committee's recommendation regarding the protected region of geosynchronous Earth orbit (GEO), target satellites with perigee and apogee of $GEO{\pm}200km$ and various inclinations are selected for analysis. The status of the GSO region was analyzed using the satellite distribution based on the orbital characteristics in publicly available two-line element data. Natural perturbation effects cause inactive satellites to drift to two stable longitudinal points. Active satellites usually maintain the designed positions as a result of regular or irregular maneuver operations against their natural drift. To analyze the detection rate of a single optical telescope, 152 out of 412 active satellites and 135 out of 288 inactive satellites in the GSO region were selected on the basis of their visibility at the observation site in Daejeon, Korea. By using various vertical view ranges and various numbers of observations of the GSO region, the detection efficiencies were analyzed for a single night, and the numbers of follow-up observations were determined. The orbital estimation accuracies were also checked using the arc length and number of observed data points to maintain the GSO satellite catalog.

A Study on Optimized MRI Fat-Saturation Technique for Brachial Plexus Patients : Focused on SPAIR and STIR Fat-Saturation (상완신경총 환자에서 최적의 자기공명영상 지방소거 기법에 관한 연구 : SPAIR, STIR 지방소거 중심으로)

  • Goo, Eunhoe
    • Journal of the Korean Society of Radiology
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    • v.8 no.5
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    • pp.271-278
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    • 2014
  • The purpose of this study is to know optimized fat suppression techniques for brachial plexus compared with STIR and SPAIR T1, T2 techniques. A total of 30 normal volunteers without brachial plexus disease were studied on a 3.0 T MRI scanner. As an analytical method, SNR, CNR, 4-point grading scale were evaluated by using three pulse sequences. As a quantitative analysis, the SNR, CNR for SPAIR T1 technique provided high value in branchial plexus roots (03.07, -2.25), branchial plexus trunks(06.70, 36.31)(p<0.05). As a qualitative Analysis, The visibility for delineation of brachial plexus, fat suppression, artifact was significantly better on SPAIR T1(3.2, 3.6, 3.4) technique(p<0.05).

The Evaluation of Fire-Resistant Performance of the Non-bearing Steel Wall Using Fire Resistant Glass (내화유리를 적용한 강재 유리벽의 내화성능 평가)

  • Lee, Jae-Sung;Yim, Hyun-Chang;Yang, Seung-Cho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.5
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    • pp.72-81
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    • 2018
  • Fireproof structures using concrete, built-up panels and dry walls are usually used in walls inside fire compartments. However, demand for glass walls is emerging due to increase in interest in visibility and external appearance. In this study on steel fire resistance walls using insulation glass, fire resistance tests and performance evaluations were conducted on 60 minute fire resistance walls and exterior walls which could be applied to interior fire compartments and 90 minute fire resistance walls which could be applied to curtain walls. According to the tests, the specimens satisfied the required fire resistance performance. The finite element analysis was conducted after the tests to evaluate the fire resistance performance of the glass walls. The analysis results showed that the preliminary evaluation of fire resistance performance would be feasible.

Safety Evaluation of Iopamidol Contrast Medium Used for Radiological Examination of a Local Clinic in Korea (방사선 검사에 사용되는 조영제 Iopamidol의 안전성 평가)

  • Park, Chang-Mook;Lee, Bo-Reum;Song, Tea-Bum;Jang, Je-Kwan;Lee, Yu-Jeung;Lee, Myung-Koo;Lim, Sung-Cil
    • YAKHAK HOEJI
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    • v.53 no.6
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    • pp.328-333
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    • 2009
  • Contrast media are substances that are used to enhance the contrast of structures or fluids within the body in medical imaging. Those are commonly used to enhance the visibility of blood vessels and the gastrointestinal tract. The aim of this study is to evaluate patients who got injected iopamidol, developed as one of contrast medium regarding changes in cardiovascular system and especially, adverse drug reactions. This study were performed on randomly selected a total of 51 patients (range of 15~85 years old) who got injected contrast medium, Iopamidol at a P hospital in Gyeonggi province from September 22nd, 2008 to January 24th, 2009. Data were collected by questionnaire though person to person. We analyzed the data by SPSS (Version 12. for windows). Methods of analysis were frequency and cross analysis. In results, 19.6% (n=10) were founded for adverse drug reactions of contrast medium. 25.0% (n=4) of 10 patients who had adverse drug reactions of contrast medium had took abdomen contrast test. 2 patients of those took contrast test for chest. Also, 3.9% (n=2) patients felt vomiting and nausea after injection of contrast medium. In conclusion, 19.6% patients experienced adverse drug reaction of contrast medium. Therefore, when taking radiation test, we should make efforts to minimize adverse drug reactions to achieve suitable and effective treatment.

Characteristics of Time Variations of PM10 Concentrations in Busan and Interpreting Its Generation Mechanism Using Meteorological Variables (부산 지역 미세먼지 농도의 시간변동 특성 및 기상인자 분석을 통한 먼지생성 해석)

  • Kim, Ji-A;Jin, Hyung-Ah;Kim, Cheol-Hee
    • Journal of Environmental Science International
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    • v.16 no.10
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    • pp.1157-1167
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    • 2007
  • In an effort to interpret the characteristics of fine particle concentrations in Busan, time variations of hourly monitored concentrations $PM_{10}$ (Particulate Matter with aerodynamic Diameter ${\le}10\;{\mu}m$) in Busan are analyzed for the period from 2000 to 2005. The characteristics of aerosol second generation formation process is also interpreted qualitatively, by using the statistical analysis of the meteorological variables including temperature, wind speed, and relative humidity. The result shows some significant annual, seasonal, weekly and diurnal variations of $PM_{10}$ concentrations. In particular, seasonal(i.e., spring) variations are governed by frequency of yellow sand events even for the non-yellow sand cases where yellow-sand days are eliminated in our analysis. However, in seasonal variation, summer season predominate lower $PM_{10}$ concentrations due to the frequent precipitation, and weekly and diurnal variations are both found to be reflecting the emission rate from traffic amount. Correlation coefficients between $PM_{10}$ concentration and meterological variables for non-yellow sand days show overall negative correlation with visibility, wind speed, cloud amounts, and relative humidity. However for non-precipitation days, during non-yellow sand period positive correlation are found clearly with relative humidity, suggesting the importance of secondary aerosol formation in Busan that can be achieved by both homogeneous aerosol formation and heterogeneous transformations resulting from hygroscopic aerosol characteristics.

An Analysis of Location Determining Factors for Starting A Food Service Business (외식사업 창업에 따른 입지 결정 요인 분석)

  • Kim, Young-Chan
    • Culinary science and hospitality research
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    • v.15 no.1
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    • pp.30-46
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    • 2009
  • This study analyzes the factors to determine the location for a food service business. The results and suggestions are as follows. Research hypothesis showed that accessibility, visibility, the property of location and community may have differences by general matters and vital statistical matters. As a result, there were significant differences statistically. Here's the critical point of the research. This result wasn't analyzed by the managers who managed restaurant business because of the restriction of time, space, etc. but by customers and soon-to-be owners or marketers, so the research requires the survey on the factors of location hereafter. Because of the restrictions, the research subject was limited, so the measurement of the vital statistics is inaccurate. According to researcher's opinion, it's a little unjustifiable to generalize this research for all types of restaurant business and conditions. The next research needs to analyze the research results by conditions and much more various subjects.

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A Study on the improvement the efficiency of the evacuation of the ship's crews (선박 승무원의 피난 효율 향상에 관한 연구)

  • Kim, Won-Ouk;Kim, Jong-Su
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.153-154
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    • 2013
  • In this study, we used the program of three-dimensional analysis of fire for analyzing visibility of smoke flow and temperature of the accommodation area what is required for the analysis of survival of the crew. In particular, I would like to propose a method for reducing the flow rate performance in order to reduce the suffocation from the smoke of the majority of personal injury. Existing vessels are designed to close the fire door automatically when the fire alarm issued. When there is no crew that dared to escape, it can delay the spread of fire and smoke flow which is determined to be very useful to improve the survival rate of the crew. However, it can be fatal to the crew whose rooms are located on the inside of the fire door that has not completed the evacuation. In this study, we check the smoke flow rate and rate of temperature rise when crew open the fire door what is closed due to fire and compare to the structure of the blocking layer.

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