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Determination of shear wave velocity profiles in soil deposit from seismic piezo-cone penetration test (탄성파 피에조콘 관입 시험을 통한 국내 퇴적 지반의 전단파 속도 결정)

  • Sun Chung Guk;Jung Gyungja;Jung Jong Hong;Kim Hong-Jong;Cho Sung-Min
    • 한국지구물리탐사학회:학술대회논문집
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    • 2005.09a
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    • pp.125-153
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    • 2005
  • It has been widely known that the seismic piezo-cone penetration test (SCPTU) is one of the most useful techniques for investigating the geotechnical characteristics including dynamic soil properties. As the practical applications in Korea, SCPTU was carried out at two sites in Busan and four sites in Incheon, which are mainly composed of alluvial or marine soil deposits. From the SCPTU waveform data obtained from the testing sites, the first arrival times of shear waves were and the corresponding time differences with depth were determined using the cross-over method, and the shear wave velocity profiles (VS) were derived based on the refracted ray path method based on Snell's law and similar to the trend of cone tip resistance (qt) profiles. In Incheon area, the testing depths of SCPTU were deeper than those of conventional down-hole seismic tests. Moreover, for the application of the conventional CPTU to earthquake engineering practices, the correlations between VS and CPTU data were deduced based on the SCPTU results. For the empirical evaluation of VS for all soils together with clays and sands which are classified unambiguously in this study by the soil behavior type classification Index (IC), the authors suggested the VS-CPTU data correlations expressed as a function of four parameters, qt, fs, $\sigma$, v0 and Bq, determined by multiple statistical regression modeling. Despite the incompatible strain levels of the down-hole seismic test during SCPTU and the conventional CPTU, it is shown that the VS-CPTU data correlations for all soils clays and sands suggested in this study is applicable to the preliminary estimation of VS for the Korean deposits and is more reliable than the previous correlations proposed by other researchers.

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An exploratory study on practice-oriented reconceptualization of self-sufficiency : Service providers' reflections on their own experiences from the field (현장의 시각으로부터 구조화된 자활 개념 탐색 연구 : 자활사업 실무자의 이해를 중심으로)

  • Choi, Sangmi;Hong, Song-Iee
    • Korean Journal of Social Welfare Studies
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    • v.49 no.3
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    • pp.5-33
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    • 2018
  • A self-sufficiency service has worked as a typical workfare policy combined with public assistance in Korea since 2000. Despite of its long history, three core pillars in administrating the self-sufficiency service, policy, research, and practice, have respectively understood the meaning of self-sufficiency in terms of their own interests. As a result, the self-sufficiency service has recently faced with its own identity issues by showing failures to its environmental changes. The current situation makes it necessary to reconceptualize the definition of self-sufficiency by exploring its in-depth understanding perceived by service providers. Specifically, we analyzed practical reflections on 35 service providers' experiences which were collected via focus group interviews for two hours. The study findings presented that service providers had two antithetical approaches towards self-sufficiency. While a dominant approach to self-sufficiency has been concentrated on improving clients' economic outcomes such as employment, job retention, the escape from welfare trap, and increasing earnings and assets, the other approach has been extended to empower clients and achieve their well-being and quality of life. Yet, these contrary perspectives have led to suffer from their role confusions and identity crisis between the work-ready process and the employment-oriented outcomes. Specifically, they described self-sufficiency in terms of psychological, social, and integrated aspects. The psychological aspect included a process of developing inner strengths, intensifying job motivation, and coping with barriers of employment. The social aspect meant a path toward social integration through recovering human relationships. The integrated aspect covered more comprehensive support for their recovery of daily life and autonomy to make a decision for their own life. In conclusion, the study findings suggest that self-sufficiency should be more extensively considered as a stepwise process towards work-ready preparations beyond ultimate economic outcomes. Such an extended concept of self-sufficiency could contribute to restructuring the whole practice of self-sufficiency including organizational and program changes in the fields.

Exploring Elementary Teacher's Challenges with the Perspective of Structure and Agency When Implementing Social Action-Oriented SSI Education Classes (사회적 실천지향 SSI 수업을 시행하면서 직면하는 초등 교사의 어려움 탐색 -구조와 행위주체성 관점에서-)

  • Lim, Sung-Eun;Kim, Jong-Uk;Kim, Chan-Jong
    • Journal of The Korean Association For Science Education
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    • v.41 no.2
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    • pp.115-131
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    • 2021
  • As the global climate change emergency is escalating, the need for 'Social Action-Oriented SSI (SAO-SSI) on climate change topics' in science education that can change society through social activity is increasing. By employing sociocultural theory, this study explores the challenges of limiting teacher's agency in implementing SAO-SSI on climate change topics in science education. Data from participant observation for 46 lessons, in-depth interviews with participants, field notes, and teacher reflection notes were analyzed by the structure of into micro- (classrooms), meso- (school), and macro- (Korea society) level. At the micro-level, the teacher's new attempts of SAO-SSI on climate change topics class made it difficult for him to identify students' understanding of climate change, because they have a low sense of perception that climate change is also their problem. In addition, the teacher had difficulties leading students' into an engagement for social action because students were skeptical about the feasibility of planned social behavior by positioning themselves as children or had difficulty in understanding social action and sympathizing with its values. At the meso-level, a school culture that encourages the implementation of a curriculum similar to that of colleagues, it was difficult to implement one's own curriculum. And it was difficult to develop expertise without the support and communications with colleagues who revealed the burden of unfamiliar science topics of climate change. In addition, conflicts arose in the process of implementing out-of-school social actions with the principal's passive support. At the macro-level, the insufficient proper material resources for SAO-SSI on climate change topics class, and negative perceptions on the students' social action in the society were acting as constraints. We offer implications for what kind of structural support and efforts from various subjects in the educational community should be provided to implement SAO-SSI on climate change topics class in science education.

An Analysis of the Impact of Strategic Festival Planning on Festival Satisfaction and Urban Regeneration : Focusing on the Gimje Horizon Festival (전략적 축제기획이 축제만족과 도시재생에 미치는 영향 분석: 김제지평선축제를 중심으로)

  • Kim, Namhee
    • 지역과문화
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    • v.7 no.1
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    • pp.59-98
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    • 2020
  • An empirical study utilizing data was performed with a variable called 'strategic planning' for festivals in order to look into the impact of a cultural tourism festival on urban regeneration. As a success factor of a festival, strategic festival planning was drawn up, and the following hypotheses were set: Seven strategic factors verified through an exploratory factor analysis will have a positive impact on festival satisfaction (festival success) and on urban regeneration, and festival satisfaction will have a positive impact on urban regeneration by having a mediating effect on it. For the analysis, the Gimje Horizon Festival was selected as it was considered as a typical case of urban regeneration through a festival, and the relationship between the festival and urban regeneration was understood by conducting a combined analysis of a quantitative analysis through a survey, a literature search, field investigations and in-depth interviews. The quantitative analysis indicates that strategic planning has a positive impact on festival satisfaction (festival success) and on urban regeneration and that festival satisfaction has a positive impact on urban regeneration. The same study result as the quantitative analysis result was obtained even through a qualitative analysis. This shows that the higher the path coefficient of strategic planning, the higher the path coefficient of festival satisfaction and urban generation and that with better strategic planning, the effects of festival satisfaction and urban regeneration are maximized. In other words, when planning and implementing a festival by actively incorporating the seven strategic planning factors which were suggested as festival success factors earlier in this study beginning from the stage of festival planning, it is likely to have a positive impact not only on the success of the festival but also on urban regeneration. This is an implication that gives a new alternative to software-based urban regeneration through festivals. It is meaningful to present the importance of festival planning and the direction of planning to maximize the effect of urban regeneration to festival planners and urban regeneration experts. This study is believed to serve as a momentum for people to take a new approach to studies on festivals and urban regeneration utilizing software in the future.

Usefulness of Flow Composite Image in Raynaud Scan ($^{201}Tl$) ($^{201}Tl$을 이용한 레이노 검사에서 동적 Composite 영상의 유용성)

  • Kim, Dae-Yeon;Shin, Gyoo-Seol;Oh, Eun-Jung;Kim, Gun-Jae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.101-104
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    • 2010
  • Purpose: Raynaud scan is divided to flow, blood pool and local-delay image. Usually, we evaluate comparison through blood pool and local-delay image. We will evaluate about usability when comparative observe blood image and local-delay image in Raynaud scan that used $^{201}Tl$ as making flow image to one sheet of images. Materials and Methods: We have selected 29 Raynaud phenomenon patients aged 14~68 years who visited department of vascular surgery between Feb. 2008 and Aug. 2009. An intravenous injection $^{201}Tl$ of 111 MBq (3 mCi) to opposite side diagonal line limbs above an internal auditing department. Equipment used Philips gamma camera forte A-Z, and collimator used LEHR. Matrix size set up to each $64{\times}64$, $128{\times}128$, $256{\times}256$ and zoom factor used to full field. Protocol of dynamic is 2 second to 155 frames. Blood pool and delay count to 300 second. We set up ROI by a foundation to data acquired in PEGASYS processing program. Each results were analyzed with the SPSS 12.0 statistical software. Results: Each averages of count ratio (Rt / Lt) to have been given at composite image, a blood pool image, delay images analyzed at Raynaud phenomenon patients is $1.25{\pm}0.39$, $1.20{\pm}0.33$, $1.11{\pm}0.17$. The sample analysis results of blood pool image and delay image contented itself with p<0.029. Also, there don't have been each difference, and blood pool image, delay image regarding composite image was able to know. Conclusion: We were able to give help for comparison to evaluate a blood pool image and a local delay image at the Raynaud scan which used $^{201}Tl$ while making a flow image to one sheet image. Identification to be visual too was possible. If you are proceeded a researcher that there was further depth, you are more appropriate for, and you may get useful information.

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Surface Exchange of Energy and Carbon Dioxide between the Atmosphere and a Farmland in Haenam, Korea (한국 해남 농경지와 대기간의 에너지와 이산화탄소의 지표 교환)

  • Hee Choon Lee;Jinkyu Hong;Chun-Ho Cho;Byoung-Cheol Choi;Sung-Nam Oh;Joon Kim
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.5 no.2
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    • pp.61-69
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    • 2003
  • Surface energy and $CO_2$ fluxes have been measured over a farmland in Haenam, Korea since July 2002. Eddy covariance technique, which is the only direct flux measurement method, was employed to quantitatively understand the interaction between the farmland ecosystem and the atmospheric boundary layer. Maintenance of eddy covariance system was the main concern during the early stage of measurement to minimize gaps and uncertainties in the dataset. Half-hourly averaged $CO_2$ concentration showed distinct diurnal and seasonal variations, which were closely related to changes in net ecosystem exchange (NEE) of $CO_2$. Daytime maximum $CO_2$ uptake was about -1.0 mg $CO_2$ m$^{-2}$ s$^{-1}$ in August whereas nighttime $CO_2$ release was up to 0.3 mg $CO_2$ m$^{-2}$ s$^{-1}$ during the summer. Both daytime $CO_2$ uptake and nighttime release decreased gradually with season. During the winter season, NEE was from near zero to 0.05 mg $CO_2$ m$^{-2}$ s$^{-1}$ . FK site was a moderate sink of atmospheric $CO_2$ until September with daily NEE of 22 g $CO_2$ m$^{-2}$ d$^{-1}$ . In October, it became a weak source of $CO_2$ with an emission rate of 2 g $CO_2$ m$^{-2}$ d$^{-1}$ . Long-term flux measurements will continue at FK site to further investigate inter-annual variability in NEE. to better understand these exchange mechanism and in-depth analysis, process-level field experiments and intensive short-term intercomparisons are also expected to be followed.

2-D/3-D Seismic Data Acquisition and Quality Control for Gas Hydrate Exploration in the Ulleung Basin (울릉분지 가스하이드레이트 2/3차원 탄성파 탐사자료 취득 및 품질관리)

  • Koo, Nam-Hyung;Kim, Won-Sik;Kim, Byoung-Yeop;Cheong, Snons;Kim, Young-Jun;Yoo, Dong-Geun;Lee, Ho-Young;Park, Keun-Pil
    • Geophysics and Geophysical Exploration
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    • v.11 no.2
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    • pp.127-136
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    • 2008
  • To identify the potential area of gas hydrate in the Ulleung Basin, 2-D and 3-D seismic surveys using R/V Tamhae II were conducted in 2005 and 2006. Seismic survey equipment consisted of navigation system, recording system, streamer cable and air-gun source. For reliable velocity analysis in a deep sea area where water depths are mostly greater than 1,000 m and the target depth is up to about 500 msec interval below the seafloor, 3-km-long streamer and 1,035 $in^3$ tuned air-gun array were used. During the survey, a suite of quality control operations including source signature analysis, 2-D brute stack, RMS noise analysis and FK analysis were performed. The source signature was calculated to verify its conformity to quality specification and the gun dropout test was carried out to examine signature changes due to a single air gun's failure. From the online quality analysis, we could conclude that the overall data quality was very good even though some seismic data were affected by swell noise, parity error, spike noise and current rip noise. Especially, by checking the result of data quality enhancement using FK filtering and missing trace restoration technique for the 3-D seismic data inevitably contaminated with current rip noises, the acquired data were accepted and the field survey could be conducted continuously. Even in survey areas where the acquired data would be unsuitable for quality specification, the marine seismic survey efficiency could be improved by showing the possibility of noise suppression through onboard data processing.

Leaching of Chromium, Copper and Arsenic in Soils and Rapid Identification of CCA-Treated Woods Using Modified PAN Stain (CCA 목재방부제 설치지역 토양의 크롬.구리.비소 분포와 PAN 지시약을 이용한 CCA 방부목의 현장 검출방법 개발)

  • Abdelhafez, Ahmed A.;Awad, Yasser M.;El-Azeem, Samy A.M. Abd;Kim, Min-Su;Ham, Kwang-Joon;Lim, Kyoung-Jae;Yang, Jae-E;Ok, Yong-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.1
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    • pp.60-67
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    • 2010
  • Although several studies have reported that Cr, Cu and As can leach from CCA-treated woods, few studies have been conducted on this topic in Korea. Therefore, this study was conducted to monitor Cr, Cu and As leaching from CCA-treated wood products and to develop a rapid identification method for CCA-treated wood products by using indicators such as PAN stain. Soil samples were collected at depths of 0-70 cm and wood samples were collected by thickness of wood layer. The soil and wood samples were then digested and analyzed for Cr, Cu and As concentrations using an atomic absorption spectrometer. The As and Cu concentrations decreased sharply with depth from 34.38 and 33.65 mg $kg^{-1}$ at 0-1 cm to 1.72 and 7.84 mg $kg^{-1}$ at 70 cm, respectively. In general, As was more mobile than Cr and Cu in the soil. For wood samples, the Cr, Cu and As concentrations were higher in the outer layer (0-0.5cm) than the inner layers (0.6-4.5cm). Evaluation of rapid identification methods revealed that 100% acetone with 0.1% PAN indicator was the best combination for detection of CCA-treated wood in the field.

Effect of Soil Characteristics and Fertilizers Application on Fresh Root Yield of Aralia continentalis K. -I. Survey on Cultivation Methods and Soil Characteristics in the Main Producting Districts (독활(獨活) (Aralia continentalis K.)주산지(主産地) 토양특성(土壤特性)과 시비양분(施肥養分)이 근경수량(根莖收量)에 미치는 영향(影響) -I. 재배법(栽培法) 실태(實態) 및 토양특성(土壤特性) 조사(調査))

  • Oh, Dong-Hoon;Han, Soo-Gon;Kim, Gap-Cheol;Na, Jong-Seong;Park, Keon-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.27 no.1
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    • pp.27-32
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    • 1994
  • These studies were Conducted to survey cultivation methods, and to analyze soil chemical properties for stable production of Aralia continentalis K., a promising medicinal crop, in the main producting districts. Aralia continentalis K. was cultivated with planting budstocks in distances of $90cm{\times}60cm$ for 3~4 years in the same field, and application rates were N 10~31 kg/10a and P, K 8~17/10a using inorganic fertilizer, that is compound fertilizer(21-17-17) for basal dressings and urea for topdressings. Most of all, the soil surveyed was coarse loamy class which was well drained and soil depth is 50~150cm in the valleys. Soil pH was low, and content of organic matters and av. $P_2O_5$ was abundant but that of exchangeable cation such as Ca, Mg, K was deficient. The relationship between growth characteristics and weight of fresh root was positive correlation in the order of No. of root, stem width, No. of node and branch, plant height and root width. On the path coefficiant analysis, the relationship between content of soil K, Ca and root yield was more apparent than other chemical properties.

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Effect of Humidified High Flow CO2 Gas Insufflation on the Coronary Endothelium (가습화한 고유량의 이산화탄소가스 통기가 관상동맥 내피세포층에 미치는 영향)

  • 최재성;김준성;서정욱;김기봉
    • Journal of Chest Surgery
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    • v.37 no.2
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    • pp.131-138
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    • 2004
  • High-flow gas insufflation to get a bloodless field during off-pump coronary artery bypass may have adverse effects on the coronary endothelium. This study was designed (1) to elucidate the effect of carbon dioxide gas insufflations on the coronary endothelium at different flow rates and (2) to assess the protective effect of humidifcation against the coronary endothelial damage. Material and Method: In nine pigs, the left anterior descending coronary artery (LAD) was exposed after a median sternotomy. The LAD was divided into 4 segments and a coronary arteriotomy was made in each LAD segment in the beating heart. The far distal arteriotomy was exposed to room air for 10 minutes and was harvested as a control. Non-humidified carbon dioxide gas at a continuous flow rate of 5 L/min (Group I), humidified carbon dioxide gas at a continuous flow rate of 5 L/min (Group II), and humidified carbon dioxide gas at a continuous flow rate of 10 L/min (Group III) were insufflated for 10 minutes on each coronary arteriotomy site, respectively. After harvesting the coronary segments, hematoxylin-eosin staining, elastic fiber staining, and immunostaining with a CD34 monoclonal antibody were performed to evaluate the depth of endothelial damage and to count the residual endothelial cells, Result: In all three groups (Group I, II, and III), internal elastic laminae were preserved, however, the endothelial layers were significantly damaged by carbon dioxide gas insufflation. The mean percentages of remaining endothelial cells were 20,9$\pm$16.7%, 39.3$\pm$19.6%, and 6.8$\pm$5.3%, in groups I, II, and III, respectively. The percentages of remaining cells were significantly higher in group II than in groups I and III (p=0.008). The percentages of remaining cells were significantly higher in group I than in group III (p=0.008). Conclusions: The harmful effect of carbon dioxide gas insufflation on the coronary endothelium was dependent on the flow rate. The addition of humidification did not protect the coronary endothelium from denudation injury caused by high flow carbon dioxide gas insufflations.