• 제목/요약/키워드: Environment-free

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Disposable in-field electrochemical potable sensor system for free available chlorine (FAC) detection

  • Chang, Seung-Cheol;Park, Deog-Su
    • Journal of Sensor Science and Technology
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    • v.16 no.6
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    • pp.449-456
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    • 2007
  • The work described in this study concerns the development of a disposable amperometric sensor for the electrochemical detection of a well-known aqueous pollutant, free available chlorine (FAC). The FAC sensor developed used screen printed carbon electrodes (SPCEs) coupled with immobilised syringaldazine, commonly used as an indicator in photometric FAC detection, which was directly immobilised on the surface of SPCEs using a photopolymer PVA-SbQ. To enable in-field analysis of FAC, a prototype hand-held electrochemical analyzer has been developed to withstand the environment with its rugged design and environmentally sealed connections; it operates from two PP3 (9 volt) batteries and is comparable in accuracy and sensitivity to commercial bench top systems. The sensitivity of the FAC sensor developed was $3.5{\;}nA{\mu}M^{-1}cm^{-2}$ and the detection limit for FAC was found to be $2.0{\;}{\mu}M$.

Corrosion Resistance Characteristics of Cr-free Coating Solution for Degraded STS316L (열화한 STS316L에 대한 Cr-free 코팅액의 내식특성)

  • Lee, So-Young;Kim, Young-Soo;Jeong, Hee-Rock;Ahn, Seok-hwan;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
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    • v.29 no.6
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    • pp.475-480
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    • 2015
  • In this study, we developed a Cr-free organic/inorganic hybrid solution and investigated its coating properties on degraded STS316L. Both the OIBD-1 solution and OIBD-2 solution had excellent corrosion resistance and adhesion ability. However, the solution had some problems in a boiling water environment. In addition, the flexibility was excellent, and the scratch resistance was relatively good.

Free exciton transitions and Varshni′s coeffecients for GaN epitaxial layers grown by horizontal LP - MOCVD

  • Lee, Joo-in;Leem, Jae-Young;Son, J.S.;Viswanath, A. Kasi
    • Journal of Korean Vacuum Science & Technology
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    • v.4 no.3
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    • pp.63-67
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    • 2000
  • We have studied the photoluminescence properties of undoped epitaxial layers of GaN on sapphire substrate grown by horizontal low pressure metal organic chemical vapor deposition method in the temperature range of 9-300 K. At 9 K the spectra are dominated by the well resolved interband free excitons A and B as well as bound excitons. Temperature dependence of free exciton transitions was studied and Varshni's coefficients for the temperature variation of bandgap were determined.

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A local path planning algorithm for free-ranging mobil robot (자율 주행로봇을 위한 국부 경로계획 알고리즘)

  • Cha, Y.Y.;Gweon, D.G.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.4
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    • pp.88-98
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    • 1994
  • A new local path planning algorithm for free-ranging robots is proposed. Considering that a laser range finder has the excellent resolution with respect to angular and distance measurements, a simple local path planning algorithm is achieved by a directional weighting method for obtaining a heading direction of nobile robot. The directional weighting method decides the heading direction of the mobile robot by estimating the attractive resultant force which is obtained by directional weighting function times range data, and testing whether the collision-free path and the copen parthway conditions are satisfied. Also, the effectiveness of the established local path planning algorithm is estimated by computer simulation in complex environment.

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Process and Results of Seoul Metropolitan Government's Environmental Health Policy Road Map (서울시 환경보건정책 로드맵 수립)

  • Lim, Ji-Ae;Kwon, Ho-Jang;Kim, Shinbum;Chou, Youngeun;Gu, Seulgi;Jeong, Hoi-Seong;Kim, Myung Han;Choi, Kyungho
    • Journal of Environmental Health Sciences
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    • v.40 no.5
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    • pp.425-434
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    • 2014
  • Objectives: The purpose of this study is to introduce the establishment process and results of the Seoul Metropolitan Government's road map on environmental health policy. Methods: The process consisted of expert group meetings, civic participation, research, and questionnaire survey for priority environmental health policy agenda items in Seoul. Results: The announced vision for the environmental health policy was "a healthy environment, safety in Seoul". This policy was established in order to define environment health policy initiatives for a period of five years with an aim to protect Seoul citizens' health from hazardous environmental factors. The resulting Seoul environmental health policy consisted of four areas and 16 key agenda items. The four areas were "Protection for children against hazardous materials", "Enhancement of health and safety of all", "Carcinogen-free and endocrine-disrupting chemical-free Seoul (reducing environmental exposure to hazardous materials), and "Establish the foundation of environmental health policy". Sixteen key agenda items include the enhancement of management of spaces for children, certification of environmental health status at schools, establishment of a unit responsible for the environmental health of children, strengthening environmental health management for susceptible populations (children, the aged, and the socioeconomically vulnerable), management of hazardous materials, physical hazardous factors (noise, radiation, etc.), indoor air quality, and the enhancement of monitoring, research, and regulation of environment health. Conclusion: The Seoul Metropolitan Government established an environmental health policy road map for a five-year period (2013-2017). To implement this environmental health policy, budget allocation, and detailed execution plans are required.

A Study on the Application Status of Convenience Facilities for the Disabled at High Schools in Seoul - Focusing on the Timing of Establishment and the Presence of Special Classes - (서울 소재 고등학교의 장애인편의시설 적용 현황분석 연구 - 설립시기 및 특수학급 유무를 중심으로 -)

  • Lee, Kyoo-Il
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.21 no.1
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    • pp.1-10
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    • 2022
  • To understand the level of disability-free environment in existing high schools, this study evaluated the level of application of facilities for the disabled at 177 high schools located in Seoul and suggested the direction of improving the physical environment of high schools. Detailed standards related to school facilities such as the Act on the guarantee of convenience promotion for persons with disabilities, senior citizens, pregnant women and nursing mothers, and the Act on the prohibition of discrimination against persons with disabilities were examined, and previous studies related to the subject were reviewed. The overall application level of facilities for the disabled was investigated by conducting a field survey of high schools, and the application level was analyzed by the period before and after the enforcement of the Acts and by the presence or absence of special classes.

Development of Revitalization Plans on the Incheon Free Economic Zone (인천경제자유구역 실태분석 및 발전방안)

  • Park, Chongdon
    • International Commerce and Information Review
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    • v.16 no.5
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    • pp.387-407
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    • 2014
  • The purpose of this study was to substantially survey the satisfaction of resident companies in Incheon Free Economic Zone to improve the investment environment of Incheon Free Economic Zone to attract more resident companies. This study implies that additional industrial lots should be secured and the restrictions against small/medium companies should be alleviated so they can grow into strong companies considering that the resident companies in Incheon Free Economic Zone are highly satisfied with their business in Incheon Free Economic Zone. As resident companies' satisfaction with administrative support, recruitment, and industrial infrastructure is low, Incheon Free Economic Zone Authority should understand and improve the specific complaints of resident companies.

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A Value Analysis of Accessibility as an Attribute of Housing (주택의 특성으로서 접근성에 대한 가치분석)

  • Lee, So-Young
    • Journal of the Korean housing association
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    • v.22 no.4
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    • pp.43-50
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    • 2011
  • In an aging society, as the number of people with disabilities increases concerns are raised about the quality of life of these people and their access to a safe environment becomes important. The purpose of this study is to find out the value of accessibility as an attribute of housing. To estimate the value of accessible, barrier-free housing, this study uses the Contingent Valuation Method (CVM) and analyzes the factors which affect the Willingness To Pay (WTP) of survey respondents by using Survival Analysis. In addition, the importance and satisfaction of barrier-free facilities in the dwellings of survey respondents was investigated. Since aging could be an important factor in influencing the need for accessibility, this study surveyed two age groups, one group (212 respondents) of people below the age of 65 and the other (162 respondents) of people above 65. The results of this study show that respondents would pay on average 2.67% more for being barrier-free when answering an open-ended question and 3.87% more for barrier-free housing when using the double referendum model. This is the increase in value that the respondents perceive as a consequence of removing all the architectural barriers from a dwelling. On average, elderly respondents would pay 2.99% of housing price for accessible features compared to 4.40% of the younger group. However, if the elderly who have willingness to pay for accessibility, the value the older group put on barrier-free housing was higher than the value perceived by the younger group. Factors that influence the WTP are importance of barrier-free facilities, education level and housing type. The value of dwellings without barriers estimated in this study shows the potential size and value of this kind of housing market to the housing development sector.

Design of Dynamic Free Span for a Subsea Pipeline: Application to the Gas Fields in the South of East Sea of Korea (해저 파이프라인의 동적 자유경간 설계: 동해 남부해역 가스전에의 응용)

  • 박한일;김창현;최경식
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.1
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    • pp.81-86
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    • 1996
  • Subsea pipelines have an important role in the overall tasks of offshore oil and gas production but arc exposed to various hazards with high potential risks of damage resulting in serious economic loss and impact on ocean environment. In this paper, the dynamic free span is analysed, which is one of main risk factors against the safety of subsea pipelines and the allowable length of dynamic free span which is important for the design of subsea pipelines is determined. The allowable free span length is examined by considering the relationship between vortex shedding frequency and natural frequency of pipeline free span, and the variation of the allowable length is analysed for different boundary conditions of pipe ends. The free span is regarded as a beam on elastic foundations and the boundary condition of the beam is generalized by modelling as restrained by linear and rotational spring at each end. A non-dimensionalized curve is obtained to facilitate the determination of exact allowable length of dynamic free span for subsea pipelines and is applied to the pipelines which is to be installed in the gas fields of the south of East Sea of Korea.

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A Study on Improvement of Barrier Free Door Standard (Barrier Free 출입문 규격기준 개선에 관한 연구)

  • Kim, In-Bae;Kim, Won-pil
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.23 no.4
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    • pp.7-15
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    • 2017
  • Purpose: The Korean government has implemented a Barrier Free Certification System since 2008 to create a secure and convenient environment for the socially disadvantaged. The drastic increase in the number of BF-certification facilities is expected due to the revision of the system and increasing the number of certification institutions. An analysis of individual evaluation items needs to be made for the BF-Certification with public confidence. Method: Korean standard, International Standard(ISO/FDIS 21542, 2011), German Standard(DIN 18040-1, 2010), Austrian Standard(${\ddot{O}}NORM$ B 1600, 2017) and Swiss Standard(Norm SIA 500 / SN 521 500, 2009) were investigated and analyzed. A comprehensive improvement plan is proposed by comparing details of the aforementioned standards and the evaluation items of BF-Certification. Results: Many problems arise in applying existing Barrier-free standards due to changes in population structure, environmental change and the use of powered wheelchairs. International standards are being improved to solve these problems. The korean standards also require improving of the Barrier Free Law and Certification System, which reflect these trends. In korean cases, standards such as the size of the doors (width and height), the Unobstructed Manoeuvring Space and Clear Space at the Latch side of the Door are required to improve standards in accordance with international standards. In addition, the expression of laws and evaluation items of BF-Certification should be clearly defined. And the application of visual contrast standards for the enhancement of perceptions presented in international standards should be considered. Implication: Barrier Free related legal standards and evaluation items of BF-Certification that are used in Korea are required to be revised in consideration of social and environmental changes. Comprehensive improvements should be made through detailed review.