• Title/Summary/Keyword: Outdoor Environments

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A study on a power plant using Dye-sensitized solar cells in low light environments (저조도 환경에서의 염료감응형 태양전지를 활용한 발전소자에 관한 연구)

  • Kim, Sun-Geum;Baek, Sung-June
    • Journal of IKEEE
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    • v.25 no.2
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    • pp.267-272
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    • 2021
  • Recently, attention has been focused on renewable energy and carbon neutrality to resolve fossil energy depletion and environmental problems. In addition, high-rise urban buildings and an increase in building energy are rapidly increasing. There are many restrictions on installing solar power in urban areas. In addition, as buildings become taller, a lot of low-light environments in which shade is formed occur. Therefore, in this study, we intend to develop a power plant capable of generating electric power in an outdoor low-light environment and indoor lighting environment. The power plant in a low-light environment used a dye-sensitized solar cell. A unit cell and a 20cm×20cm module were manufactured, and the electrical characteristics of the power plant were measured using light sources of LED, halogen lamp, and 3-wavelength lamp. The photoelectric conversion efficiency of the unit cell was 17.2%, 1.28%, 19,2% for each LED, halogen lamp, and 3-wavelength lamp, and the photoelectric conversion efficiency of the 20cm×20cm module was 10.9%, 8.7%, and 11.8%, respectively. In addition, the maximum power value of the module was 13.1mW, 15.7 mW, and 14.2 mW for each light source, respectively, confirming the possibility of power generation in a low-light environment

The comparison between measurement and prediction values for the vertical illuminances by relux program in the survey region (상용 조명해석 프로그램(Relux)을 이용한 가로등 주택침입광 예측값과 실측값 비교)

  • Jung, Dae-Kwan;Park, Hyung-Kyu;Jung, Joon-Sig
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.98-104
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    • 2018
  • The assessment of the light trespass in terms of light pollution is difficult due to the complexity of light environments. As a result, the light pollution research has examined the influences of light pollution using simulation program such as RELUX. However, there still exists a differences between the real measurement value and the simulation value for the light trespass. In this paper, we analyzed the light trespass using the RELUX simulation program, and compared results with real measurement values. In this study, the regions (Seoul, Incheon, etc.) were investigated regarding the light trespass for outdoor lighting. The survey of vertical illuminance was analyzed measuring point (more than 2 point) out the window that was expected to light trespass for the higher anticipated to illumination. The illuminational predicted values for the RELUX program were compared with maximum one. As a result of this study, the illuminational errors between the measurement values and predicted values for the simulation were examined from -0.97 lx to 0.65 lx except 2.08 lx and -7.70 lx. The light trespass was analyzed the higher by how much the located close to the height, length, width of the outdoor lighting for the window. For measuring predicted values using RELUX, it was not sufficiently considered in the simulation conditions because of environmental factors and investigator error etc. Limitations of this study include the limited number of measurements, and greater field data is required in future studies.

The Study on Concentration of PM10 and Heavy Metal in Public Schools at Chung-Nam Area (충남 지역 일부 학교의 PM10과 중금속 농도에 관한 연구)

  • Son, Bu-Soon;Song, Mi-Ra;Kim, Jung-Duk;Cho, Tae-Jin;Yang, Won-Ho;Chung, Tae-Woong
    • Journal of Environmental Science International
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    • v.17 no.9
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    • pp.1005-1013
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    • 2008
  • In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of $PM_{10}$ for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is $43.27\;{\mu}g/m^3$ for new classrooms while $53.38\;{\mu}g/m^3$ for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors $46.71\;{\mu}g/m^3$, outdoors $50.46\;{\mu}g/m^3$, and personal $41.62\;{\mu}g/m^3$. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors $39.11\;{\mu}g/m^3$, outdoors $34.86\;{\mu}g/m^3$, and personal $49.01\;{\mu}g/m^3$. 2. Cr concentration level within dust was slightly higher in summer indoors ($101.50{\pm}32.10\;ng/m^3$) and outdoors ($100.89{\pm}35.18\;ng/m^3$) than winter indoors ($85.80{\pm}48.95\;ng/m^3$) and outdoors ($74.43{\pm}38.93\;ng/m^3$), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of $PM_{10}$ concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.

A Trail Plan for At-Risk Walkers in Mountainous Urban Park - A Focus on Umyen Nature Park - (산지형 도시공원 내 보행약자를 위한 산책로 조성 연구 -우면산도시자연공원을 대상으로-)

  • Han, Bong-Ho;Bae, Jung-Hee;Ahn, In-Su;Lee, Kyong-Jae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.6
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    • pp.22-33
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    • 2009
  • This study was undertaken to provide a basis for planning trail standards, providing rights of movement, improvement of health and the experience of nature for at-risk walkers for application to the Umyen Park site. This study researched related laws, manuals, scholastic writing and the established site, a raku-raku mountain trail in Osata, Japan. By referencing these results and similar standards, a conceptual trail plan for at-risk walkers was created. The plan suggests five points -- accessibility, convenience, social aspects, economic efficiency, and environmentally-friendliness -- and referenced an evaluation of outdoor living environments for the elderly. The planning standards are comprised of four steps that are ranked in order and are related to the selection of location, trail structure, route patterns, and equipment. Plans for trails catering to at-risk walkers in Umyen Park were then based on these standards. As a result, it was found that the mountain has both a high elevation and abundant natural resource, both of which must be taken into account during planning. This study is valuable because it is one of the first studies of trail plans for at-risk walkers made in mountainous urban parte. Subsequent research can use the standards of this study for further evaluation while future modifications must reflect changing needs and details.

Structural Integrity Evaluation of Mechanically Fastened FRP Beams Under the Effects of Sustained Loads and Environments (지속하중과 환경영향을 받은 MF-FRP 보강보의 구조건전성 평가)

  • Lee, Jae-Ha;Kim, Woo-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.1
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    • pp.10-18
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    • 2014
  • Mechanically fastening FRP (MF-FRP) strips using nails and anchors, has been shown to provide a more ductile behavior to the strengthened structural element than using bonded FRP. To further advance the state of the knowledge on this strengthening method, the current study examined environmental effects for six months on MF-FRP beams. Reinforced concrete beams strengthened with mechanically fastened FRP strips and subjected to sustained loads for six months were exposed to outdoor weather and constant high temperatures ($40^{\circ}C$). For comparison, the behavior of RC beam with and without sustained loads was evaluated. Results from flexural tests did not show any significant degradation or change of failure mode as a result of sustained load and of environmental effects such as high temperatures and outdoor weather over a period of six months. Failure of the beams was governed by FRP delamination followed by concrete crushing as not much load applied to the nail and anchors because of slip effects.

Exposure and Risk Assessment of Benzene and PM10 for Sub-populations using Monte-Carlo Simulations (Monte-Carlo 모의실험을 통한 부분 인구집단별 벤젠 및 PM10의 노출 및 위해성 평가)

  • Park, Jinhyeon;Yang, So Young;Park, Yunkyung;Ryu, Hyeonsu;Kim, Eunchae;Choe, Youngtae;Heo, Jung;Cho, Mansu;Yang, Wonho
    • Journal of Environmental Health Sciences
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    • v.45 no.3
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    • pp.247-257
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    • 2019
  • Objectives: The Korea Ministry of Environment regulates concentrations of hazardous air pollutants (HAPs) through Atmosphere Environmental Standards to protect public health from HAPs. However, simply determining the exceedance of HAP concentrations has several limitations and more comprehensive assessment is required. In addition, integrated risk assessment is needed considering exposure in all microenvironments, including outdoor as well as indoor environments. The purpose of this study was to assess the differences in risk by sub-population groups according to time-activity patterns and reported concentrations, as well as the lifetime risk for Koreans. Methods: In this study, we calculated time-weighted average exposure concentrations for benzene and $PM_{10}$ among preschool-age children, students, housewifes, workers, and the elderly using residential time and concentrations for indoor (house, school or workplace, other), outdoor, and transport by the meta-analysis method. The risk assessments were conducted by excess cancer risk and disease death risk using 1,000,000 Monte-Carlo simulations for probabilistic analysis. Results: Preschool-age children, students, housewifes, workers, and the elderly spent 91.9, 86.0, 79.8, 82.2, and 77.3% of their day in their house, workplace, or school, respectively. The more than 99% excess cancer risk for benzene exceed 1.0E-06 in all sub-populations and lifetime. The acute disease death risk for $PM_{10}$ for housewifes and workers for lifetime were 3.35E-04 and 3.18E-04, and chronic disease death risks were 2.84E-03 and 2.70E-03, respectively. Conclusions: The risk of benzene and $PM_{10}$ by sub-population group and for the lifetime of housewifes and workers were assessed. Benzene showed risky results for this study. All disease death risks of $PM_{10}$ were higher than 1.0E-04 and showed different risks by sub-population. This study can be used as a basis for lifetime exposure and risk assessment to benzene and $PM_{10}$.

Early Frost Damage and Diagnose of Damage Depth Due to Early Frost Damage of the Concrete According to the Thickness of Members (부재 두께 변화에 따른 콘크리트의 초기동해 특성 분석 및 깊이진단)

  • Kim, Tae-Woo;Han, Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.19 no.2
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    • pp.131-138
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    • 2019
  • Recently, there are many structures exposed to severe outdoor environments, which results in rapid degradation of durability of the concrete structures. there can be rapid deterioration of the concrete structures from early frost damage due to the insufficient curing in low outdoor temperature condition. The objective of this study is to investigate the effect of thickness change conditions and binding material on early frost damage depth of the concrete exposed to cold weather in winter, and is to clearly assess damage depth of the concrete structure due to early frost damage. Specimens with 300x300x(150, 200, 250, 300mm) were prepared. OPC and OPC+FA+BS were adopted for binders. Test results indicate that the depth of the early frost damage was deeper with the decrease of thickness of members. The brightness of specimens were reduced when the member thickness was thinner. When determining the depth of early frost damage, it can be distinguished into dark color and relatively bright color when dried for approximately 30 minutes in the indoors of $20^{\circ}C$ in temperature and 60% in relative humidity after submerging in water for 24 hours. The dark colored part can be determined easily when measured with vernier calipers.

Design of a Displacement and Velocity Measurement System Based on Environmental Characteristic Analysis of Laser Sensors for Automatic Mooring Devices (레이저 센서의 환경적 특성 분석에 기반한 선박 자동계류장치용 변위 및 속도 측정시스템 설계)

  • Jin-Man Kim;Heon-Hui Kim
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.980-991
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    • 2023
  • To prevent accidents near the quay caused by a ship, ports are generally designed and constructed through navigation and berthing safety assessment. However, unpredictable accidents such as ship collisions with the quay or personal accidents caused by ropes still occur sometimes during the ship berthing or mooring process. Automatic mooring systems, which are equipped with an attachment mechanism composed of robotic manipulators and vacuum pads, are designed for rapid and safe mooring of ships. This paper deals with a displacement and velocity measurement system for the automatic mooring device, which is essential for the position and speed control of the vacuum pads. To design a suitable system for an automatic mooring device, we first analyze the sensor's performance and outdoor environmental characteristics. Based on the analysis results, we describe the configuration and design methods of a displacement and velocity measurement system for application in outdoor environments. Additionally, several algorithms for detecting the sensor's state and estimating a ship's velocity are developed. The proposed method is verified through some experiments for displacement and speed measurement targeted at a moving object with constant speed.

Detailed Deterioration Evaluation and Analysis of Conservation Environment for the Seosanmaaesamjonbulsang (Rock-carved Triad Buddha in Seosan), Korea (서산마애삼존불상의 정밀 손상도 평가와 보존환경 분석)

  • Lee, Sun-Myung;Lee, Chan-Hee;Kim, Ji-Young
    • Journal of Conservation Science
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    • v.26 no.3
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    • pp.277-294
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    • 2010
  • The Seosanmaaesamjonbulsang (National Treasure No. 84) consists of light gray and coarse to mediumgrained biotite granite with partly developed pegmatite and quartz vein. The host rock is divided into dozens of rock blocks with various shape along irregular discontinuity plane. The evaluation results of discontinuity systems reveal that the host rock were exposed to instable sloping environments. Results of deterioration diagnosis show that the degree of damage has been made worse by physical weathering and surface discoloration laying stress on part that vertical and horizontal joints are massed. Generally, deterioration rate of the triad Buddha surface cover with 42.7%, however, the rate of physical weathering and surface discoloration are subdivided to 9.6% and 33.1%, respectively. Ultrasonic measurements indicate that the triad Buddha was reached highly weathered grade in general. And the rock material was weaken to show low velocity zone of 1,000m/s along irregular joint systems. Indoor and outdoor mean relative humidity of the shelter was recorded more than 70% during every season, and high frequency appears in high relative humidity range over 95%. Such environments seem to have produced dew condensation on the rock surface with rainfall and supply water, promoted physical, chemical and biological weathering along crack and joint, resulting in high permeation of water and percentage of water content. Therefore, it is judged that for scientific conservation of the triad Buddha it needs environment control through persistent preservation environment monitoring including water problem.

Evaluation of Atopy and Its Possible Association with Indoor Bioaerosol Concentrations and Other Factors at the Residence of Children (초등학생 가정을 대상으로 한 바이오에어로졸 노출과 아토피와의 연관성 평가)

  • Ha, Jin-Sil;Jung, Hea-Jung;Byun, Hyae-Jeong;Yoon, Chung-Sik;Kim, Yang-Ho;Oh, In-Bo;Lee, Ji-Ho;Ha, Kwon-Chul
    • Journal of Environmental Health Sciences
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    • v.37 no.6
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    • pp.406-417
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    • 2011
  • Objectives: Exposure to bioaerosols in the indoor environment could be associated with a variety adverse health effects, including allergic disease such atopy. The objectives of this study were to assess children's exposure to bioaerosol in home indoor environments and to evaluate the association between atopy and bioaerosol, environmental, and social factors in Ulsan, Korea. Methods: Samples of viable airborne bacteria and fungi were collected by impaction onto agar plates using a Quick Take TM 30 and were counted as colony forming units per cubic meter of air (CFU/$m^3$). Bioaerosols were identified using standard microbial techniques by differential stains and/or microscopy. The environmental factors and possible causes of atopy based on ISAAC (International Study of Allergy and Asthma in Childhood) were collected by questionnaire. Results: The bioaerosol concentrations in indoor environments showed log-normal distribution (p < 0.01). Geometric mean (GM) and geometric standard deviation (GSD) of airborne bacteria and fungi in homes were 189.0 (2.5), 346.1(2.0) CFU/$m^3$, respectively. Indoor fungal levels were significantly higher than those of bacteria (p < 0.001). The concentration of airborne bacteria exceeded the limit recommended by the Korean Ministry of Environment, 800 CFU/$m^3$, in three out of 92 samples (3.3%) from 52 homes. The means of indoor to outdoor ratio (I/O) for airborne bacteria and fungi were 8.15 and 1.13, respectively. The source of airborne bacteria was not outdoors but indoors. GM of airborne bacteria and fungi were 217.6, 291.8 CFU/$m^3$ in the case's home and 162.0, 415.2 CFU/$m^3$ in the control's home respectively. The difference in fungal distributions between case and control were significant (p = 0.004) and the odds ratio was 0.996 (p = 0.027). Atopy was significantly associated with type of house (odds ratio = 1.723, p = 0.047) and income (odds ratio = 1.891, p = 0.041). Some of the potential allergic fungal genera isolated in homes were Cladosporium spp., Botrytis spp., Aspergillus spp., Penicillium spp., and Alternatia spp. Conclusions: These results suggest that there this should be either 'was little' meaning 'basically no significant association was found' or 'was a small negative' mean that an association was found but it was minor. It's a very improtant distinction. Association between airborne fungal concentrations and atopy and certain socioeconomic factors may affect the prevalence of childhood atopy.