• Title/Summary/Keyword: Environment characteristics

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COLOR DIFFERENCES BETWEEN RESIN COMPOSITES BEFORE- AND AFTER-POLYMERIZATION, AND SHADE GUIDES (복합레진의 광중합 전·후와 shade guide의 색차 비교)

  • Chon, Yi-Ju;Cho, Sung-Shik;Um, Chung-Moon
    • Restorative Dentistry and Endodontics
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    • v.24 no.2
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    • pp.299-309
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    • 1999
  • The composite resin, due to its esthetic qualities, is considered the material of choice for restoration of anterior teeth. With respect to shade control, the direct-placement resin composites offer some distinct advantages over indirect restorative procedures. Visible-light-cured (VLC) composites allow dentists to match existing tooth shades or to create new shades and to evaluate them immediately at the time of restoration placement. Optimal intraoral color control can be achieved if optical changes occurring during application are minimized. An ideal VLC composite, then, would be one which is optically stable throughout the polymerization process. The shade guides of the resin composites are generally made of plastic, rather than the actual composite material, and do not accurately depict the true shade, translucency, or opacity of the resin composite after polymerization. So the numerous problems associated with these shade guides lead to varied and sometimes unpredictable results. The aim of this study was to assess the color changes of current resin composite restorative materials which occur as a result of the polymerization process and to compare the color differences between the shade guides provided with the products and the actual resin composites before- and after-polymerization. The results obtained from this investigation should provide the clinician with information which may aid in improved color match of esthetic restoration. Five light activated, resin-based materials (${\AE}$litefil, Amelogen Universal, Spectrum TPH VeridonFil-Photo, and Z100) and shade guides were used in this study. Three specimens of each material and shade combination were made. Each material was condensed inside a 1.5mm thick metal mold with 10mm diameter and pressed between glass plates. Each material was measured immediately before polymerization, and polymerized with Curing Light XL 3000 (3M Dental products, USA) visible light-activation unit for 60 seconds at each side. The specimens were then polished sequentially on wet sandpaper. Shade guides were ground with polishing stones and rubber points (Shofu) to a thickness of approximately 1.5mm. Color characteristics were performed with a spectrophotometer (CM-3500d, Minolta Co., LTD). A computer-controlled spectrophotometer was used to determine CIELAB coordinates ($L^*$, $a^*$ and $b^*$) of each specimen and shade guide. The CIELAB measurements made it possible to evaluate the amount of the color difference values (${\Delta}E{^*}ab$) of resin composites before the polymerization process and shade guides using the post-polishing color of the composite as a control, CIE standard D65 was used as the light source. The results were as follows. 1. Each of the resin composites evaluated showed significant color changes during light-curing process. All the resin composites evaluated except all the tested shades of 2100 showed unacceptable level of color changes (${\Delta}E{^*}ab$ greater than 3.3) between pre-polymerization and post-polishing state. 2. Color differences between most of the resin composites tested and their corresponding shade guides were acceptable but those between C2 shade of ${\AE}$litefil and IE shade of Amelogen Universal and their respective shade guides exceeded what is acceptable. 3. Comparison of the mean ${\Delta}E{^*}ab$ values of materials revealed that Z100 showed the least overall color change between pre-polymerization and post-polishing state followed by ${\AE}$litefil, VeridonFil-Photo, Spectrum TPH, and Amelogen Universal in the order of increasing change and Amelogen Universal. Spectrum TPH, 2100, VeridonFil-Photo and ${\AE}$litefil for the color differences between actual resin and shade guide. 4. In the clinical environment, the shade guide is the better choice than the shade of the actual resin before polymerization when matching colors. But, it is recommended that custom shade guides be made from resin material itself for better color matching.

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Occurrences of Uranium and Radon-222 from Groundwaters in Various Geological Environment in the Hoengseong Area (횡성지역 다양한 지질환경에서 지하수 중 우라늄 및 라돈-222 산출특성)

  • Jeong, Chan Ho;Yang, Jae Ha;Lee, Yu Jin;Lee, Yong Cheon;Choi, Hyeon Young;Kim, Moon Su;Kim, Hyun Koo;Kim, Tae Seong;Jo, Byung Uk
    • The Journal of Engineering Geology
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    • v.25 no.4
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    • pp.557-576
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    • 2015
  • Groundwaters in granite, gneiss, and two-mica granite formations, including faults, in the Hoengseong area are examined to determine the relationship between their uranium and radon-222 contents and rock types. The chemical compositions of 38 groundwater samples and four surface water samples collected in the study area were analyzed. Sixteen of the samples showing high uranium and radon-222 contents were repeatedly analyzed. Surface radioactivities were measured at 30 points. The uranium and radon-222 concentrations in the groundwater samples were in the ranges of 0.02-49.3 μg/L and 20-906 Bq/L, respectively. Four samples for uranium and 35 samples for radon had concentrations exceeding the alternative maximum contaminant level of the US EPA. The chemical compositions of groundwaters indicated Ca(Na)-HCO3 and Ca(Na)-NO3(HCO3+Cl) types. The pH values ranged from 5.71 to 8.66. High uranium and radon-222 contents in the groundwaters occurred mainly at the boundary between granite and gneiss, and in the granite area. The occurrence of uranium did not show any distinct relationship to that of radon-222. The radon-222, an inert gas, appeared to be dissolved in the groundwater of the aquifer after wide diffusion along rock fractures, having been derived from the decay of uranium in underground rocks. The results in this study indicate that groundwater of neutral or weakly alkaline pH, under oxidizing conditions and with a high bicarbonate content is favorable for the dissolution of uranium and uranium complexes such as uranyl or uranyl-carbonate.

Growth of CdSe thin films using Hot Wall Epitaxy method and their photoelectrical characteristics (HWE방법에 의한 CdSe 박막 성장과 광전기적 특성)

  • Hong, K.J.;Lee, K.K.;Lee, S.Y.;You, S.H.;Shin, Y.J.;Suh, S.S.;Jeong, J.W.;Jeong, K.A.;Shin, Y.J.;Jeong, T.S.;Kim, T.S.;Moon, J.D.;Kim, H.S.
    • Journal of Sensor Science and Technology
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    • v.6 no.4
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    • pp.328-336
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    • 1997
  • The CdSe thin films were grown on the Si(100) wafers by a hot wall epitaxy method (HWE). The source and substrate temperature are $600^{\circ}C$ and $430^{\circ}C$ respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. From Hall data, the mobility was increased in the temperature range 30K to 150K by impurity scattering and decreased in the temperature range 150k to 293k by the lattice scattering. In order to explore the applicability as a photoconductive cell, we measured the sensitivity(${\gamma}$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of $1.39{\times}10^{7}$, the MAPD of 335mW, and the rise and decay time of 10ms and 9.5ms, respectively.

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Early Growth of Cultured Larval Haddock, Melanogrammus aeglefinus (Haddock, Melanogrammus aeglefinus 자어의 초기성장)

  • Park, In-Seok;Johnson, Stewart C.;Hur, Jun-Wook
    • Development and Reproduction
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    • v.10 no.4
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    • pp.271-275
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    • 2006
  • The objective of this study was to examine the early growth of haddock, Melanogrammus aeglefinus larvae from a series of reared specimens for provide information to developmental biology and more information on the aspect of aquaculture in the larvae of this species. Larvae were reared in the laboratory and sampled periodically for developmental study until 67 days after hatching. An increase in total length of fish indicated continuous growth, described by the growth expression of the type $TL=3.5374e^{0.0536X}(r^2=0.8759$, where TL is total length and X is at days after hatching) and $BW=0.0002e^{0.1858X}(r^2=0.8671$, where BW is body weight and X is at days after hatching), respectively. Pattern of body depth and pectoral fin length are instantaneous growth which expression of the type $BD=0.3545e^{0.0778X},\;r^2=0.9563$(where BD is body depth and X is at days after hatching) for body depth growth and the type $PL=0.0111e^{0.1591X},\;r^2=0.9194$(where PL is pectoral fin length and X is at days after hatching) for pectoral fin length growth. The relationship of body depth and total length expressed as $BD=0.2397X-0.5735(r^2=0.9957$, where BD is body depth and X is total length), and pectoral fin length and total length is $PL=0.1929X-1.3767(r^2=0.9882$, where PL is pectoral fin length and X is total length) pectoral fin length against body depth simultaneously recorded for juvenile haddock(PL=0.8117BD-0.9718, $r^2=0.9814$, where PL is pectoral fin length and BD is body depth). Relationship of body depth and body weight was expressed the type of $BD=-9.4734X^2+19.046X+1.3672,\;r^2=0.941$(where BD is body depth and X is body weight), and pectoral fin length and body weight expressed the type of $PL=6.379X^2+14.023X+0.3774,\;r^2=0.9494$(where PL is pectoral fin length and X is body weight). From this point view, growth characteristics of juvenile haddock in this experiment may be useful to establish a successful culture technique for rearing larval haddock.

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Status of Brain-based Artistic Education Fusion Study - Basic Study for Animation Drawing Education (뇌기반 예술교육 융합연구의 현황 - 애니메이션 드로잉 교육을 위한 기초연구)

  • Lee, Sun Ju;Park, Sung Won
    • Cartoon and Animation Studies
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    • s.36
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    • pp.237-257
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    • 2014
  • This study is the process of performing the interdisciplinary fusion study between multiple fields by identifying the status on the previous artistic education considering the brain scientific mechanism of image creativity and brain-based learning principles. In recent years, producing the educational methods of each field as the fusion study activities are emerging as the trend and thanks to such, the results of brain-based educational fusion studies are being presented for each field. It includes artistic fields such as music, art and dance. In other words, the perspective is that by understanding the operating principles of the brain while creativity and learning is taking place, when applying various principles that can develop the corresponding functions as a teaching method, it can effectively increase the artistic performance ability and creativity. Since the animation drawing should be able to intuitively recognize the elements of movement and produce the communication with the target beyond the delineative perspective of simply drawing the objects to look the same, it requires the development of systematic educational method including the methods of communication, elements of higher cognitive senses as well as the cognitive perspective of form implementation. Therefore, this study proposes a literature study results on the artistic education applied with brain-based principles in order to design the educational model considering the professional characteristics of animation drawing. Therefore, the overseas and domestic trends of the cases of brain-based artistic education were extracted and analyzed. In addition, the cases of artistic education studies applied with brain-based principles and study results from cases of drawing related education were analyzed. According to the analyzed results, the brain-based learning related to the drawing has shown a common effect of promoting the creativity and changes of positive emotion related to the observation, concentration and image expression through the training of the right brain. In addition, there was a case of overseas educational application through the brain wave training where the timing ability and artistic expression have shown an enhancement effect through the HRV training, SMR, Beta 1 and neuro feedback training that strengthens the alpha/seta wave and it was proposing that slow brain wave neuro feedback training contributes significantly in overcoming the stress and enhancing the creative artistic performance ability. The meaning of this study result is significant in the fact that it was the case that have shown the successful application of neuro feedback training in the environment of artistic live education beyond the range of laboratory but the use of the machine was shown to have limitations for being applied to the teaching methods so its significance can be found in providing the analytical foundation for applying and designing the brain-based learning principles for future animation drawing teaching methods.

Feeding Characteristics of the Japanese Anchovy, Engraulis japonicus According to the Distribution of Zooplankton in the Coastal Waters of Southern Korea (한국 남해 연안 해역에서 출현하는 동물플랑크톤의 분포에 따른 멸치 섭이 특성)

  • Kim, Min Jung;Youn, Seok Hyun;Kim, Jin-Yeong;Oh, Chul-Woong
    • Korean Journal of Environmental Biology
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    • v.31 no.4
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    • pp.275-287
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    • 2013
  • The Japanese anchovy Engraulis japonicus is a widespread species in the western North Pacific and major fishery resource. To understand the spatio-temporal variation of anchovy prey items in the coastal waters of southern Korea, the stomach contents of anchovy and the structure of the zooplankton community were analysed at three sites (Jindo, Yeosu and Tong-yeong) from July 2011 to February 2012. The main prey items in Yeosu and Jindo were cyprid stage of barnacle (>35%) and copepod Calanus sinicus (>22%) in July, respectively, while, predominant ones in Tongyeong were small copepods, Paracalanus parvus s.l. (41%) and Corycaeus affinis (22%). During this period, the dominant zooplankton were cladoceran Evadne tergestina (39%) in Yeosu, small copepod, P. parvus s.l. (28%) in Jindo and cladoceran E. tergestina (14%) in Tongyeong. The dominant prey items were barnacle larvae and copepods in summer, phytoplankton and Pseudodiaptomus marinus in autumn and P. parvus s.l. and cold water copepod, Centropages abdominalis in winter. Anchovy prefer the prey item C. sinicus (3%) over E. tergestina (39%), which was a dominant species in the catching site in summer. P. marinus (0.5%) and C. abdominalis (0.9%) were preferred over P. parvus s.l. (30%, 21%) in autumn and winter, respectively. Prey items varied with area and season in the coastal waters of southern Korea. These results suggest that the prey selectivity of anchovy showed high flexibility and adaptability in the study waters.

Personalized Recommendation System for IPTV using Ontology and K-medoids (IPTV환경에서 온톨로지와 k-medoids기법을 이용한 개인화 시스템)

  • Yun, Byeong-Dae;Kim, Jong-Woo;Cho, Yong-Seok;Kang, Sang-Gil
    • Journal of Intelligence and Information Systems
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    • v.16 no.3
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    • pp.147-161
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    • 2010
  • As broadcasting and communication are converged recently, communication is jointed to TV. TV viewing has brought about many changes. The IPTV (Internet Protocol Television) provides information service, movie contents, broadcast, etc. through internet with live programs + VOD (Video on demand) jointed. Using communication network, it becomes an issue of new business. In addition, new technical issues have been created by imaging technology for the service, networking technology without video cuts, security technologies to protect copyright, etc. Through this IPTV network, users can watch their desired programs when they want. However, IPTV has difficulties in search approach, menu approach, or finding programs. Menu approach spends a lot of time in approaching programs desired. Search approach can't be found when title, genre, name of actors, etc. are not known. In addition, inserting letters through remote control have problems. However, the bigger problem is that many times users are not usually ware of the services they use. Thus, to resolve difficulties when selecting VOD service in IPTV, a personalized service is recommended, which enhance users' satisfaction and use your time, efficiently. This paper provides appropriate programs which are fit to individuals not to save time in order to solve IPTV's shortcomings through filtering and recommendation-related system. The proposed recommendation system collects TV program information, the user's preferred program genres and detailed genre, channel, watching program, and information on viewing time based on individual records of watching IPTV. To look for these kinds of similarities, similarities can be compared by using ontology for TV programs. The reason to use these is because the distance of program can be measured by the similarity comparison. TV program ontology we are using is one extracted from TV-Anytime metadata which represents semantic nature. Also, ontology expresses the contents and features in figures. Through world net, vocabulary similarity is determined. All the words described on the programs are expanded into upper and lower classes for word similarity decision. The average of described key words was measured. The criterion of distance calculated ties similar programs through K-medoids dividing method. K-medoids dividing method is a dividing way to divide classified groups into ones with similar characteristics. This K-medoids method sets K-unit representative objects. Here, distance from representative object sets temporary distance and colonize it. Through algorithm, when the initial n-unit objects are tried to be divided into K-units. The optimal object must be found through repeated trials after selecting representative object temporarily. Through this course, similar programs must be colonized. Selecting programs through group analysis, weight should be given to the recommendation. The way to provide weight with recommendation is as the follows. When each group recommends programs, similar programs near representative objects will be recommended to users. The formula to calculate the distance is same as measure similar distance. It will be a basic figure which determines the rankings of recommended programs. Weight is used to calculate the number of watching lists. As the more programs are, the higher weight will be loaded. This is defined as cluster weight. Through this, sub-TV programs which are representative of the groups must be selected. The final TV programs ranks must be determined. However, the group-representative TV programs include errors. Therefore, weights must be added to TV program viewing preference. They must determine the finalranks.Based on this, our customers prefer proposed to recommend contents. So, based on the proposed method this paper suggested, experiment was carried out in controlled environment. Through experiment, the superiority of the proposed method is shown, compared to existing ways.

Examination of Urban Gardening as an Everydayness in Urban Residential Area, Haebangchon (도심주거지에 나타나는 일상문화로서의 도시정원가꾸기에 대한 고찰 - 용산구 용산동2가 해방촌을 중심으로 -)

  • Sim, Joo-Young;Zoh, Kyung-Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.2
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    • pp.1-12
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    • 2015
  • This study explores urban gardening and garden culture in residential area as an everydayness that has been overlooked during the modern period urbanization and investigates the meaning and value of urban gardening from the perspective of urban formations and growth in spontaneous urban residential area, Haebangchon. The result identified that urban gardening as a meaning of contemporary culture is a new clue to improving the urban physical environment and changing the lives and community network of residents. Haebangchon is one of the few remaining spontaneous habitations in Seoul, and was created as a temporary unlicensed shantytown in 1940s. It became the representative habitation for common people in downtown Seoul through the revitalization of the 60s and the local reform through self-sustaining redevelopment projects during the 70s through the 90s. This area still contains the image of times during the 50s to the 60s, the 70s to the 80s and present, with the percentage of long-term stay residents high. Within this context, the site is divided into third quarters, and the research undertaken by observation and investigation to determine characteristics of urban gardening as an everydayness. It can be said that urban gardening and garden culture in Haebangchon is a unique location culture that has accumulated in the crevices of the physical condition and culture of life. These places are an expression of resident's desires that seeking out nature and gardening as revealed in densely-populated areas and the grounds of practical acting and participating in care and cultivation. It forms a unique, indigenous local landscape as an accumulation of everyday life of residents. Urban gardens in detached home has retained the original function of the dwelling and the garden, or 'madang', and takes on the characteristic of public space through the sharing of a public nature as well as semi-private spatial characteristic. Also, urban gardens including small kitchen garden and flowerpots that appear in the narrow streets provide pleasure as a part of nature that blossoms in narrow alley and functions as a public garden for exchanging with neighbors by sharing produce. This paper provides the concept of redefining the relationship between the private-public area that occurs between outside spaces that are cut off in a modern city.

A Study on Embodiment Aspects and Practice Strategies of Welfare Ideology in Contemporary Urban Park (현대 도시공원에서 나타나는 복지이념 구현양상 및 실천 전략에 관한 연구)

  • Cho, Han-Sol;Han, So-Young;Zoh, Kyung-Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.6
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    • pp.60-71
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    • 2014
  • In this study, on the assumption that the urban park originally is imbued with a public welfare ideology, said public welfare ideology and its characteristics were attended to among the various social roles that the urban park currently fulfills. Aspects of welfare meaning in urban parks were attempted to be identified with the former history of urban parks and the movements of the connections between modern parks and welfare territories. The ideologies, benefits and practices regarding the welfare role that the urban park has played from the past to the present were examined and the backgrounds and contexts within which the welfare ideologies have been expressed in the urban park were examined. In order to examine the implicated public welfare ideologies of the urban park, case studies were conducted to identify how they are expressed and practiced in the present times and the facilitation of these parks and public welfare both in the U.S. and the South Korea. The study results of the cases show that expressions of public welfare in urban parks are composed of more specific and visible programs and strategies in the present times, which are different from the simple proclamatory ways in the past. Particularly, in order to visibly practice a public welfare ideology, many-sided integrated designs are conducted along with various public welfare institutions and programs inside and outside of the urban park. The conclusions from this study are as follows. First, the urban park plays a role as a space to realize public welfare ideology, to create welfare benefits and to realize social welfare. Modern urban parks are used as an indicator to measure the actual conditions of social welfare and are a social environmental commodity that can offer universal benefits to urban residents. Second, many-sided integrated designs are tried along with various public welfare institutions at urban parks, which visibly practice public welfare ideologies in the present. In addition, public welfare institutions greatly influence the consistent development of the resources in the urban park. Third, if the detailed utilization of the regional facilities infrastructure could be brought along with multidimensional approaches about the resources in the urban park, it could be much closer to the lives of residents and could secure a space for increasing resident quality of life.

A Study on Decreasing Effects of Ultra-fine Particles (PM2.5) by Structures in a Roadside Buffer Green - A Buffer Green in Songpa-gu, Seoul - (도로변 완충녹지의 식재구조에 따른 초미세먼지(PM2.5)농도 저감효과 연구 - 서울 송파구 완충녹지를 대상으로 -)

  • Hwang, Kwang-Il;Han, Bong-Ho;Kwark, Jeong-In;Park, Seok-Cheol
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.4
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    • pp.61-75
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    • 2018
  • This study aims to verify the effect of green buffers, built as urban planning facilities on the reduction of ultra-fine particulate($PM_{2.5}$) and analyze changes in ultra-fine particles by structure, green volume and planting types of wayside green buffers, thus drawing the factors that can be used when green buffers are built to reduce ultra-fine particulate based on the results. This study selected Songpa-gu, and investigated 16 sites on 5 green buffers adjacent to two of Songpa-gu's main roads, 'Yangjaedaero' and 'Songpadaero'. This study divided all the green spaces into three different types-slope type, plain type and mounding type, and analyzed the mean green volume. As a result of measuring the concentration of $PM_{2.5}$, this study found that it was $55.5{\mu}g/m^3$ on average in winter, which was a harmful level according to the integrated environmental index provided by Seoul City, saying that levels above $50{\mu}g/m^3$ may have a harmful effect on sensitive groups of people. Particularly, the concentration of $PM_{2.5}$ was $38.6{\mu}g/m^3$ on average in spring, which exceeded the mean concentration of $PM_{2.5}$ in Seoul City in 2015. The mean concentrations of $PM_{2.5}$ in every investigation spot were $46.6{\mu}g/m^3$ for sidewalks, $45.5{\mu}g/m^3$ for green spaces and $42.9{\mu}g/m^3$ for residential areas, all of which were lower than $53.2{\mu}g/m^3$ for roads, regardless of the season. The concentration of $PM_{2.5}$ for residential areas was the lowest. In the stage of confirming the effect of green buffers, this study analyzed the correlation between the green volume of vegetation and the fluctuated rate of ultra-fine particles. As a result, it was found that the green coverage rate of trees and shrubs was related to the crown volume in every investigation spot but were mutually and complexly affected by each other. Therefore, this study judged that the greater the number of layers of shrubs that are made, the more effective it is in reducing the concentration of $PM_{2.5}$. As for seasonal characteristics, this study analyzed the correlation between the concentration of $PM_{2.5}$ for residential areas in winter and the green coverage rate of each green space type. As a result, this study found that there was a negative correlation showing that the higher the shrub green coverage rate is, the lower the concentration value becomes in all the slope-type, plain-type and mounding-type green spaces. This study confirmed that the number of tree rows and the number of shrub layers have negative correlations with the fluctuated concentration rate of $PM_{2.5}$. Especially, it was judged that the shrub green volume has greater effect than any other factor, and each green space type shows a negative correlation with the shrub coverage rate in winter.