• Title/Summary/Keyword: change of variables

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Vulnerability Assessment of the Air Pollution Using Entropy Weights : Focused on Ozone (엔트로피 가중치를 활용한 대기오염 취약성 평가 - 오존을 중심으로 -)

  • Lee, Sang-hyeok;Kang, Jung Eun;Bae, Hyun Joo;Yoon, Dong Keun
    • Journal of the Korean association of regional geographers
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    • v.21 no.4
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    • pp.751-763
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    • 2015
  • Both the selection of indicators and weights for them are critical issues in the vulnerability assessment. This study is to assess the air pollution vulnerability focused on ozone for 249 local jurisdictions using weights calculated by the entropy methodology and then examine the applicability of the methodology. We selected indicators for air pollution vulnerability assessment and standardized them. Subsequently, we calculated weights of each indicator using the entropy method and then integrated them into the vulnerability index. The exposure indicators consider meteorological and air pollution factors and the sensitivity of the local jurisdiction include variables on vulnerable areas and environments. The adaptive capacity contains socio-economic characteristics, health care capacities and air pollution managemental factors. The results show that Hwaseong-si, Gwangjin-gu, Gimpo-si, Gwangju-si, Gunpo-si are among the highest vulnerabilities based on the simple aggregation of indicators. And vulnerability-resilience (VRI) aggregation results indicates the similar spatial pattern with the simple aggregation outcomes. This article extends current climate change vulnerability assessment studies by adopting the entropy method to evaluate relative usefulness of data. In addition, the results can be used for developing customized adaptation policies for each jurisdiction reflecting vulnerable aspects.

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Influences of Thermal Effluents on the Epilithic Algal Community in Small Stream Originating from the Seokjung Hot Spring (온천 배수 유입에 따른 소형 하천의 생태계 변화와 회복에 관한 연구 -소형 하천에서 온천 배수가 부착조류 군집에 미치는 영향)

  • 정연태;문연자;김미연;최민규;길봉섭
    • Korean Journal of Environmental Biology
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    • v.17 no.3
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    • pp.345-358
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    • 1999
  • To study the influences of thermal effluents flowing from hot spring on epilithic algal community, seasonal survey was carried out at stream and its watersheds from Seokjeong hot spring in Chollabuk-Do, Korea. Totally 7 points were divided into three regions fur sampling of water and epilithic algae, such as the direct effected, uneffected and the mixed region, respectively. At the discharging points of effluents, a dark-green cyanobacterial mat were remarkably constructed, mainly by two cyanobacteria, Oscillatoria and Phormidium. The mat formation were more obvious at low temperature than any other season, and even result in disappear with downstream and season. Totally, one hundred and fifty-three taxa of epilithic algae were classified with 15 unidentified species. Among the, diatoms occupied 58% of total species, whereas cyanobacteria was 67% of total biomass, comparatively. In terms of stream direction, relative abundance of cyanobacteria was only limited in the upstream in cold season, and result in this pattern disappeared with season change. Although all physicochemical variables at the discharging points, was very high, compare to other points, they were quickly decreased downstream. Among them, some heavy metals were not detected or below the detection levels at downstream. Nitrate nitrogen increased with downstream, as well as phosphorus and sulfate have a similar trend throughout, while ammonia quickly decreased in the initial period of discharging effluents. This suggest that although the thermal effluent with high temperature and organic compounds could polluted the small study stream, various contributions such as flowing water, intake of uneffected streawater and collaboration of cyanobacterial mat and stream bottom gradually induces a stable water system.

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Research of Pre-Service Science Teachers' Understanding About the Chemistry Concept and Analysis of Incorrect Responses: Focus on Middle School Curriculum (예비 과학교사의 화학 개념에 대한 이해도 조사와 오답 반응 분석: 중학교 교육과정을 중심으로)

  • Lee, Hyun-Jeong;Choi, Won-Ho
    • Journal of the Korean Chemical Society
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    • v.55 no.6
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    • pp.1030-1041
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    • 2011
  • We investigated the understanding of pre-service science teacher about the chemistry concept of middle school curriculum using some items in National Assessment of Educational Achievement and analyzed the result according to background variables of pre-service science teacher. The result was that there were some pre-service science teachers who select incorrect answer at all items, pre-service science teachers don't fully understand the concept needed to solve item. And the percentage of correct answer at some items was low regardless of selection of chemistry as an elective subject at CSAT(College Scholastic Ability Test). We found some facts through the depth interviews to find the cause of the result. First, the misconception acquired in middle school days is tend not to change until college student. Second, the formation of misconception is affected by the study habit with which solve problem by simple calculation and memory without essential understanding. Third, the study habit with which solve problem by simple calculation and memory without essential understanding could not replace misconceptions acquired in middle school days with scientific concept regardless of selection of chemistry as an elective subject at CSAT.

Recovery Process of Forest Edge Formed by Clear-cutting Harvest in Korean Red Pine (Pinus densiflora) Forest in Gangwondo, South Korea (강원도 남부 지역에서 소나무림 벌채 후 형성된 숲 가장자리의 회복 과정)

  • Kim, Jun-Soo;Cho, Yong-Chan;Bae, Kwan-Ho
    • Journal of Korean Society of Forest Science
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    • v.106 no.1
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    • pp.1-9
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    • 2017
  • Forest harvest as large scale artificial disturbance makes edge environment in both clear-cutted and forested habitat. To clarify the development and recovery process of forest edge after disturbances is essential to understand vegetation responses and landscape level consequences such as edge-distance. In Korea, after clear-cutting, edge-related changes of environment and vegetation was not clarified yet. In Korean red pine (Pinus densiflora) forest, by applying space-for-time approach (sites with undisturbed and 1, 3, 10, 16 yr after cutting), the edge-related change of plant abundance and abiotic factors were determined for 20 line-transect (60 m) and 340 ($1m{\times}5m$) quadrats, and clarified depth and duration of the disturbance. Immediately after edge formation, within 15m form the edge, biotic and abiotic factors such as cover, richness, canopy openness, temperature and moisture content exhibited larger changes compared to forest interior. Plant abundance and abiotic variables were stabilized at the level of forest inside within 16 yr and 10 yr after edge creation, respectively. Woody (tree and shrub) species generally was showed larger increment with proximity to edge than did herb or graminoid species. In addition, negative interactions between woody and herbaceous species were detected during the period of forest edge closure. Our results suggested that depth of forest edge formed by clear-cutting of Korean red pine forest was at least from 15 m to 20 m and edge effect were likely sustained more than 16 years. As the first empirical study on edge-distance between two contrast habitats of clear-cutted and adjacent forest in South Korea, the analytical reality on landscape structure and habitat patches can be improved.

Behavior of Reinforcement Ratio on Concrete Beams Reinforced with Lab Spliced GFRP Bar (GFRP 보강근으로 겹이음된 콘크리트 보의 보강비에 따른 거동특성)

  • Choi, Yun Cheul;Park, Keum Sung;Choi, Hyun Ki;Choi, Chang Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.1
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    • pp.67-76
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    • 2011
  • The use of glass-fiber-reinforced polymer (GFRP) bars in reinforced concrete (RC) structures has emerged as an alternative to traditional RC due to the corrosion of steel in aggressive environments. Although the number of analytical and experimental studies on RC beams with GFRP reinforcement has increased in recent decades, it is still lower than the number of such studies related to steel RC structures. This paper presents the experimental moment deflection relations of GFRP reinforced beam which are spliced. Test variables were different reinforcement ratio and cover thickness of GFRP rebars. Seven concrete beams reinforced with steel GFRP re-Bars were tested. All the specimens had a span of 4000mm, provided with 12.7mm nominal diameter steel and GFRP rebars. All test specimens were tested under 2-point loads so that the spliced region be subject to constant moment. The experimental results show that the ultimate moment capacity of beam increasing of the reinforcement ratio. Failure mode of these specimens was sensitively vary according to the reinforcement ratio. The change of beam effective depth, which was caused by cover thickness variation, controlled the maximum strength and deflection because of cover spalling in tension face.

A Comparative Study on the Characteristics of Friction with/without shoes by Analyzing Bio-signals during walking (보행 시 생체신호분석을 통한 신발 착용 유무에 따른 마찰 특성 비교)

  • Oh, Seong-geun;Kim, Jin-Hyun
    • Journal of Convergence for Information Technology
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    • v.8 no.6
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    • pp.59-66
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    • 2018
  • The utilized coefficient of friction (UCOF) as a ratio of the shear force to the normal force on the ground during walking is used to identify the point at which slip is likely to occur. Shoe walking will change the utilized coefficient of friction by shoe design such as sole thickness and hardness, heel shape, and outsole pattern. In this study, subjects are 21 adults (10 female, 11 male, age: $25.2{\pm}2.3yrs$, height: $165.6{\pm}7.2cm$), analysis variables were walking speed, GRF, when the UCOF is maximal, and Tangent of CoP-CoM angle, and correlation analysis with the utilized friction coefficient (UCOF). As a result, First, for the shod walking the time point which UCOF is maximum about heel strike was faster and the magnitude was larger than for barefoot walking. Second, the correlation between the tangent of CoP-CoM and UCOF of right foot was higher at the left heel striking point (UCOF2_h) which occurred in the post propulsion phase than at the right heel striking point (UCOF1_h). This suggests that the right foot UCOF is related to the braking phase of left foot( which is the propulsion phase of right foot) rather than the braking phase of right foot.

Development of regression functions for human and economic flood damage assessments in the metropolises (대도시에서의 인적·물적 홍수피해 추정을 위한 회귀함수 개발)

  • Lim, Yeon Taek;Lee, Jong Seok;Choi, Hyun Il
    • Journal of Korea Water Resources Association
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    • v.53 no.12
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    • pp.1119-1130
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    • 2020
  • Flood disasters have been recently increasing worldwide due to climate change and extreme weather events. Since flood damage recovery has been conducted as a common coping strategy to flood disasters in the Republic of Korea, it is necessary to predict the regional flood damage costs by rainfall characteristics for a preventative measure to flood damage. Therefore, the purpose of this study is to present the regression functions for human and economic flood damage assessments for the 7 metropolises in the Republic of Korea. A comprehensive regression analysis was performed through the total 48 simple regression models on the two types of flood damage records for human and economic costs over the past two decades from 1998 to 2017 using the four kinds of nonlinear equations with each of the six rainfall variables. The damage assessment functions for each metropolis were finally selected by the evaluation of the regression results with the coefficient of determination and the statistical significance test, and then used for the human and economic flood damage assessments for 100-year rainfall in the 7 metropolises. The results of this study are expected to provide the basic information on flood damage cost assessments for flood damage mitigation measures.

A Study on the Effect of Consumer Characteristics on Intention to Use in Mobile Location-Based Advertising (모바일 위치기반 광고에서 소비자 특성이 이용의도에 미치는 영향에 관한 연구)

  • Cho, Won-Sang;Han, Dong-Gyun;Whang, Jae-Hoon
    • Informatization Policy
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    • v.29 no.1
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    • pp.38-59
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    • 2022
  • The development of IT technology and the spread of smartphones are having a great impact on businesses and consumers. Consumers have been able to acquire more diverse and larger amounts of information than in the past due to information provided through smartphones and information search on the internet, which has a significant influence on decision-making. Companies have also become sensitive to such changes in consumer behavior patterns, reflected in their marketing. In addition, among the various characteristics of smartphones, location-based technology has become an important factor in providing targeted marketing from a company's point of view. Such technological development and social change have led to the expansion of the mobile advertising market, which promotes products or services based on the location of consumers and provides benefits such as discount coupons. In this study, we have analyzed the influence of consumer characteristics on intention to use in mobile location-based advertising, which has become an important marketing method in the mobile advertising market. The effects of variables of personalization, engagement, coupon proneness, economic efficiency, and irritation on attitude and information privacy concerns were analyzed, and the effects of attitude and information privacy concerns on intention to use were analyzed. The results of this study are deemed to be able to suggest factors to consider when providing mobile location-based advertising to consumers in the future.

Mountain Meteorology Data for Forest Disaster Prevention and Forest Management (산림재해 방지와 산림관리를 위한 산악기상정보)

  • Keunchang, Jang;Sunghyun, Min;Inhye, Kim;Junghwa, Chun;Myoungsoo, Won
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.24 no.4
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    • pp.346-352
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    • 2022
  • Mountain meteorology in South Korea that is covered mountains with complex terrain is important for understanding and managing the forest disaster and forest ecosystems. In particular, recent changes in dryness and/or rainfall intensity due to climate change may cause an increase in the possibility of forest disasters. Therefore, accurate monitoring of mountain meteorology is needed for efficient forest management. Korea Forest Service (KFS) is establishing the Automatic Mountain Meteorology Observation Stations (AMOS) in the mountain regions since 2012. 464 AMOSs are observing various meteorological variables such as air temperature, relative humidity, wind speed and direction, precipitation, soil temperature, and air pressure for every minute, which is conducted the quality control (QC) to retain data reliability. QC process includes the physical limit test, step test, internal consistency test, persistence test, climate range test, and median filter test. All of AMOS observations are open to use, which can be found from the Korean Mountain Meteorology Information System (KoMIS, http://mtweather.nifos.go.kr/) of the National Institute of Forest Science and the Public Data Portal (https://public.go.kr/). AMOS observations with guaranteed quality can be used in various forest fields including the public safety, forest recreation, forest leisure activities, etc., and can contribute to the advancement of forest science and technology. In this paper, a series of processes are introduced to collect and use the AMOS dataset in the mountain region in South Korea.

The Opportunities for New Filters in the Developing Low Tar Markets (저타르 담배의 시장증대에 따른 새로운 필터의 역할)

  • Shepherd, R.J.K.;Taylor, M.J.
    • Proceedings of the Korean Society of Tobacco Science Conference
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    • 1997.10a
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    • pp.79-90
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    • 1997
  • The world-wide cigarette market is becoming increasingly regulated. This involves restrictions on the freedom to advertise, restrictions on where people can smoke, and in some ways of most importance, limits on cigarette smoke deliveries. In particular, in an increasingly large number of countries maximum tar legislation is being enacted. In many cases, such as the European Union, this type of legislation is progressive and over time it is entirely conceivable that maximum permitted tar deliveries will be reduced to as low as 5 mg, possibly with additional restrictions on smoke nicotine deliveries. In addition, the pace of change is increasing as more and more countries embark on tar reduction programmes. The key challenge facing the cigarette industry is to manage these changes in such a way which ensures that product acceptability is maintained at as high a level as is possible in these circumstances. There are a number of ways of achieving this involving filter ventilation, modifying blends and using different filter constructions The real innovation comes when combining these in a way that gives the most acceptable balance of all these competing variables as far as the smoker is concerned. Undoubtedly, the nature of the filter is of crucial importance in designing the most acceptable low tar products, and this paper will discuss some of the filter types which are currently in use in the various low tar markets around the world. Also, some thoughts about the future in terms of new filter developments will be presented.

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