• Title/Summary/Keyword: Visibility Analysis

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Performance Analysis of Machine Learning Based Spatial Disorientation Detection Algorithm Using Flight Data (비행데이터를 활용한 머신러닝 기반 비행착각 탐지 알고리즘 성능 분석)

  • Yim Se-Hoon;Park Chul;Cho Young jin
    • Journal of Advanced Navigation Technology
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    • v.27 no.4
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    • pp.391-395
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    • 2023
  • Helicopter accidents due to spatial disorientation in low visibility conditions continue to persist as a major issue. These incidents often stem from human error, typically induced by stress, and frequently result in fatal outcomes. This study employs machine learning to analyze flight data and evaluate the efficacy of a flight illusion detection algorithm, laying groundwork for further research. This study collected flight data from approximately 20 pilots using a simulated flight training device to construct a range of flight scenarios. These scenarios included three stages of flight: ascending, level, and descent, and were further categorized into good visibility conditions and 0-mile visibility conditions. The aim was to investigate the occurrence of flight illusions under these conditions. From the extracted data, we obtained a total of 54,000 time-series data points, sampled five times per second. These were then analyzed using a machine learning approach.

Presidential Candidate's Speech based on Network Analysis : Mainly on the Visibility of the Words and the Connectivity between the Words (18대 대통령 선거 후보자의 연설문 네트워크 분석: 단어의 가시성(visibility)과 단어 간 연결성(connectivity)을 중심으로)

  • Hong, Ju-Hyun;Yun, Hae-Jin
    • The Journal of the Korea Contents Association
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    • v.14 no.9
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    • pp.24-44
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    • 2014
  • This study explores the political meaning of candidate's speech and statement who run for the 18th presidential election in the viewpoint of communication. The visibility of the words and the connectivity between the words are analyzed in the viewpoint of structural aspect and the vision, policy. The visibility of the words is analyzed based on the frequency of the words mentioned in the speech or the statement. The connectivity between the words are analyzed based on the network analysis and expressed by graph. In the case of candidate Park, the key word is the happiness of the people and appointment. The key word for candidate Moon is regime change and the Korean Peninsula and the key word for candidate Ahn is the people and change. This study contributes positively to the study of candidate's discourse in the viewpoint of methodology by using network analysis and exploring scientifically the connectivity of the words. In the theoretical aspect this study uses the results of network analysis for revealing what is the leadership components in the speech and the statement. In conclusion, this study highlights the extension of the communication studies.

Exploration of a New Method of Spatial Analysis to Predict the Pedestrian Pattern in the Circulation Spaces of Shopping Centers: The Case of Shenzhen

  • Bai, Xue;Yao, Shen
    • International Journal of High-Rise Buildings
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    • v.7 no.2
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    • pp.171-183
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    • 2018
  • Turner and Penn (1) from UCL have proved that Visibility Graph Analysis (VGA) can be used as a more accurate method to predict the pedestrian distribution in building spaces. However, this methodology neglects certain elements that are of special influence on pedestrian distribution in buildings, especially the entrances and exits. Based on Space Syntax, this dissertation improves on the traditional method of Visibility Graph Analysis, using three shopping centers in Shenzhen as examples, attempts to explore a new parameter - "attenuation index of pedestrians at the entrances and exits" - using relevant data of the entrances and exits of the three cases, and combines it with traditional VGA analysis through weighted calculation, in order to provide more accurate predictions of pedestrian patterns in shopping centers.

Study on Downlink Capacity based on the Visibility Analysis between KPLO and KDSA/DSN (시험용 달 궤도선과 KDSA 및 DSN 간 가시성 분석을 통한 다운링크 용량 연구)

  • Kim, Changkyoon;Jeon, Moon-Jin;Lee, Sang-Rok;Lim, Seong-Bin
    • Journal of Satellite, Information and Communications
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    • v.11 no.3
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    • pp.86-91
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    • 2016
  • KARI(Korea Aerospace Research Institute) has been developing the KPLO(Korea Pathfinder Lunar Orbiter) for Korean first lunar exploration, and analysing various subjects for the mission success. Especially the performance of the communication is one of important factors, because massive scientific and technical data acquired by multiple payloads might be transferred to ground stations on the Earth. In this paper, we explained the study on the 1-day average downlink capacity based on the visibility analysis between ground stations and KPLO, and described its results.

Opto-Chemical Characteristics of Visibility Impairment Using Semi-Continuous Aerosol Monitoring in an Urban Area during Summertime (에어로졸의 준실시간 관측에 의한 여름철 도시지역 시정 감쇄 현상의 광ㆍ화학적인 특성 분석)

  • 김경원;김영준
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.6
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    • pp.647-661
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    • 2003
  • For continuous monitoring of atmospheric visibility in the city of Kwanaju, Korea, a transmissometer system consisting of a transmitter and a receiver was installed at a distance of 1.91 km across the downtown Kwanaju. At the transmitter site an integrating nephelometer and an aethalometer were also installed to measure the scattering and absorption coefficients of the atmosphere, respectively. At the receiver site. an URG PM$_{2.5}$ cyclone sampler and an URG-VAPS (Versatile Air Pollutant Sampler) with three filter packs and two denuders were used to collect both PM$_{2.5}$ and PM$_{10}$ samples at a 2-hour or 12-hour sampling interval for aerosol chemical analysis. Sulfate, organic mass by carbon (OMC), nitrate, elemental carbon (EC) components of fine aerosol were the major contributors to visibility impairment. Diurnal variation of visibility during best-case days showed rapid improvement in the morning hours, while it was delayed until afternoon during the worst-case days. Aerosol mass concentration of each aerosol component for the worst-case was calculated to be 11.2 times larger than the best-case for (NH$_4$)$_2$SO$_4$(NHSO), 19.0 times for NH$_4$NO$_3$ (NHNO), 2.2 times for OMC, respectively. Also result shows that elemental carbon and fine soil (FS) were 3.7 and 2.2 times more than those of best-case. respectively- Sum of total contributions of wet NHSO and NHNO to light extinction was calculated to be 301 Mm$^{-1}$ for the worst-case. However, sum of contributions by dry NHSO and NHNO was calculated to be 123 Mm$^{-1}$ for the best case. Mass extinction efficiencies of fine and coarse particles were calculated to be 5.8$\pm$0.3 $m^2$/g and 1.8$\pm$0.1 $m^2$/g, respectively.ely.

Effect of Agricultural Machine Lighting systems on Drivers Night Visibility (농기계의 등화장치가 운전자의 야간시인성에 미치는 영향)

  • Choi, Seung hyun;Lee, Sung yeol;Jang, Taek young;Do, Myung sik
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.4
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    • pp.25-35
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    • 2017
  • This study aimed to analyze a driver's night visibility, according to the installation of a lighting system for driving an agricultural machine during the night time. For the night visibility analysis, a luminance measurement test on the lighting system and a gaze duration measurement test through eye movement measurement devices were carried out. In the luminance measurement test, the increase of luminance was confirmed as relative distance from an agricultural machine was closer and the conditions of the lighting equivalence are improved. Also the gaze duration measurement test, total gaze duration from an agricultural machine increased, as the conditions of the lighting equivalence are improved. In addition, it was identified that the difference in average gaze duration from an agricultural machine was statistically significant as the agricultural machine was driven in high speed. In conclusion, when the lighting system is installed on an agricultural machine, a driver's night visibility from the agricultural machine improves, which is expected to be enormously helpful to the prevention of agricultural machine accidents.

The Fashion Product Purchasing Behavior of Indonesian Muslim Women (인도네시아 무슬림여성의 패션제품 구매 행동)

  • Park, Younghee;Park, Hyewon
    • Journal of Fashion Business
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    • v.25 no.3
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    • pp.17-35
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    • 2021
  • The purpose of this study was to analyze the different consumption patterns of fashion products according to the demographic characteristics and religious variables of Muslim women in Indonesia. The research method consisted of a questionnaire, which surveyed Muslim women in Indonesia, whose ages ranged from teens to 40s. The final questionnaire made use of 301 responses, and the analysis methods included 𝛘2-testing, factor analysis, and ANOVA. The results of this survey are as follows: For differences in average monthly clothing purchase costs, there were significant differences according to age, monthly income, final education, and whether or not the respondent wore a hijab, but there was also significant difference according to marital status and religious faithfulness. Muslim women's clothing purchasing factors were practicality, visibility, fit-to-wear, and design. In terms of the differences in factors which were considered when purchasing clothing, they depended on whether or not the respondent was married, practicality and visibility according to age, visibility according to final education, and religious faithfulness. There were significant differences in practicality and visibility, but not according to monthly income. When accounting for the differences in the places where Muslim women bought fashion products, there were significant differences according to marital status and age. In terms of the differences in reasons for choosing a place of purchase, there were significant differences according to age, monthly income, final education, and the degree of hijab wearing.

Evaluation of Suitability of Retroreflective Material Locations by Motion Analysis of the Wearer of Safety Clothing (안전의복 착용자의 동작분석에 의한 재귀반사 소재 위치의 적합성 평가)

  • Soon Ja Park;Satoko Tanabe;Mariko Sato
    • Human Ecology Research
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    • v.61 no.3
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    • pp.493-503
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    • 2023
  • Since ISO 20471 regulations(2013) were enacted, high-visibility clothing made of fluorescent fabric and retroreflective materials has been standardized to distinguish the wearers from the surrounding background in a dark place and to protect them. Accordingly, we made high-visibility safety clothing based on the international standards, and examined the positions of the retro-reflective materials on the attached sites to evaluate the suitability of the positions, by 3 types of safety clothing and the body regions when the wearers work or move. Two retro-reflective films of 5cm-horizontal lines were attached to the front/back of the upper-wear, and the lower-wear. Vertical lines were attached from the shoulder to the horizontal waistline. To analyze the motion in 3-dimension, we took pictured infrared-reflective markers on the retro-reflective film covered with yellow-tape on the front-side when 6 subjects wearing experimental garments performed 6 types of motions. According to the metronome tempo, the motions were performed for 30 seconds and repeated 6 motions ①~⑥ by 3 experimental clothing. Among the 6 motions, significant differences in the appearance rate of the markers by body region during the motions were found in 5 types except for motion ③. Significant differences by the post-hoc test were shown in motions ④ and ⑥ as well. Therefore, for high-visibility safety clothing, it is necessary to anticipate the worker's motion and consider the attaching position of the retro-reflective material. It is considered desirable to attach the retro-reflective materials to several places where the clothing is hard to wrinkle.

Multivariate Analysis for Classification of Smog Type during the Summer Season in Seoul, Korea (다변량해석을 이용한 서울시 하계 스모그의 형태 분류)

  • 홍낙기;이종범;김용국
    • Journal of Korean Society for Atmospheric Environment
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    • v.9 no.4
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    • pp.278-287
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    • 1993
  • In order to calssify smog type durnig the summer season in Seoul, air Quality and meterorological data were analyzed by multivariate analysis. Among 15 variables relating to visibility, 10 variables were selected by multiple regression analysis for clustering of smog types; total suspended particle, sulfur dioxide, ozone, ntrogen dioxide, total hydrocarbon, south-north wind component, ralative humidity, precipitable water, mixing height and air temperature. Somg types were grouped into three clusters using cubic clustering criterion and the mumbers of days in each cluster were contained 74, 28 and 16 days. Each cluster was seperated clearly by sulfur dioxide, precipitable water and air teperature. The first cluster was representative of high ozone concentration and prevailing meterological conditions for ozone formation. Therefore, visibility in the first cluster was considered to be affected by photochemical smog. The third cluster showed characteristics of sulphurous smog type due to the higher concentration of primary pollutant, based on the dry condition than that in another cluster. On the other hand, the characteristic of the second cluster was not relatively clear, but considered to be in an intermediate characteristic between photochemical smog and sulphurous smog type.

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