• Title/Summary/Keyword: Critical Time

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Iron chelating agent, deferoxamine, induced apoptosis in Saos-2 osteosarcoma cancer cells (Saos-2 골육종 세포에서 iron chelating agent, deferoxamine에 의한 apoptosis 유도)

  • Park, Eun Hye;Lee, Hyo Jung;Lee, Soo Yeon;Kim, Sun Young;Yi, Ho Keun;Lee, Dae Yeol;Hwang, Pyoung Han
    • Clinical and Experimental Pediatrics
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    • v.52 no.2
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    • pp.213-219
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    • 2009
  • Purpose:Iron is a critical nutritional element that is essential for a variety of important biological processes, including cell growth and differentiation, electron transfer reactions, and oxygen transport, activation, and detoxification. Iron is also required for neoplastic cell growth due to its catalytic effects on the formation of hydroxyl radicals, suppression of host defense cell activities, and promotion of cancer cell multiplication. Chronic transfusion-dependent patients receiving chemotherapy may have iron overload, which requires iron-chelating therapy. We performed this study to demonstrate whether the iron chelating agent deferoxamine induces apoptosis in Saos-2 osteosarcoma cells, and to investigate the underlying apoptotic mechanism. Methods:To analyze the apoptotic effects of an iron chelator, cultured Saos-2 cells were treated with deferoxamine. We analyzed cell survival by trypan blue and crystal violet analysis, apoptosis by nuclear condensation, DNA fragmentation, and cell cycle analysis, and the expression of apoptotic related proteins by Western immunoblot analysis. Results:Deferoxamine inhibited the growth of Saos-2 cell in a time- and dose-dependent manner. The major mechanism for growth inhibition with the deferoxamine treatment was by the induction of apoptosis, which was supported by nuclear staining, DNA fragmentation analysis, and flow cytometric analysis. Furthermore, bcl-2 expression decreased, while bax, caspase-3, caspase-9, and PARP expression increased in Saos-2 cells treated with deferoxamine. Conclusion:These results demonstrated that the iron chelating agent deferoxamine induced growth inhibition and mitochondrial-dependent apoptosis in osteosarcoma Saos-2 cells, suggesting that iron chelating agents used in controlling neoplastic cell fate can be potentially developed as an adjuvant agent enhancing the anti-tumor effect for the treatment of osteosarcoma.

A Hybrid Forecasting Framework based on Case-based Reasoning and Artificial Neural Network (사례기반 추론기법과 인공신경망을 이용한 서비스 수요예측 프레임워크)

  • Hwang, Yousub
    • Journal of Intelligence and Information Systems
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    • v.18 no.4
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    • pp.43-57
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    • 2012
  • To enhance the competitive advantage in a constantly changing business environment, an enterprise management must make the right decision in many business activities based on both internal and external information. Thus, providing accurate information plays a prominent role in management's decision making. Intuitively, historical data can provide a feasible estimate through the forecasting models. Therefore, if the service department can estimate the service quantity for the next period, the service department can then effectively control the inventory of service related resources such as human, parts, and other facilities. In addition, the production department can make load map for improving its product quality. Therefore, obtaining an accurate service forecast most likely appears to be critical to manufacturing companies. Numerous investigations addressing this problem have generally employed statistical methods, such as regression or autoregressive and moving average simulation. However, these methods are only efficient for data with are seasonal or cyclical. If the data are influenced by the special characteristics of product, they are not feasible. In our research, we propose a forecasting framework that predicts service demand of manufacturing organization by combining Case-based reasoning (CBR) and leveraging an unsupervised artificial neural network based clustering analysis (i.e., Self-Organizing Maps; SOM). We believe that this is one of the first attempts at applying unsupervised artificial neural network-based machine-learning techniques in the service forecasting domain. Our proposed approach has several appealing features : (1) We applied CBR and SOM in a new forecasting domain such as service demand forecasting. (2) We proposed our combined approach between CBR and SOM in order to overcome limitations of traditional statistical forecasting methods and We have developed a service forecasting tool based on the proposed approach using an unsupervised artificial neural network and Case-based reasoning. In this research, we conducted an empirical study on a real digital TV manufacturer (i.e., Company A). In addition, we have empirically evaluated the proposed approach and tool using real sales and service related data from digital TV manufacturer. In our empirical experiments, we intend to explore the performance of our proposed service forecasting framework when compared to the performances predicted by other two service forecasting methods; one is traditional CBR based forecasting model and the other is the existing service forecasting model used by Company A. We ran each service forecasting 144 times; each time, input data were randomly sampled for each service forecasting framework. To evaluate accuracy of forecasting results, we used Mean Absolute Percentage Error (MAPE) as primary performance measure in our experiments. We conducted one-way ANOVA test with the 144 measurements of MAPE for three different service forecasting approaches. For example, the F-ratio of MAPE for three different service forecasting approaches is 67.25 and the p-value is 0.000. This means that the difference between the MAPE of the three different service forecasting approaches is significant at the level of 0.000. Since there is a significant difference among the different service forecasting approaches, we conducted Tukey's HSD post hoc test to determine exactly which means of MAPE are significantly different from which other ones. In terms of MAPE, Tukey's HSD post hoc test grouped the three different service forecasting approaches into three different subsets in the following order: our proposed approach > traditional CBR-based service forecasting approach > the existing forecasting approach used by Company A. Consequently, our empirical experiments show that our proposed approach outperformed the traditional CBR based forecasting model and the existing service forecasting model used by Company A. The rest of this paper is organized as follows. Section 2 provides some research background information such as summary of CBR and SOM. Section 3 presents a hybrid service forecasting framework based on Case-based Reasoning and Self-Organizing Maps, while the empirical evaluation results are summarized in Section 4. Conclusion and future research directions are finally discussed in Section 5.

Social Learning Values in the Justification Discourses for One Million-pyeong Park, Busan, South Korea (담론분석을 통한 100만평공원운동의 사회학습적 가치)

  • Lee, Sungkyung;Kim, Seung-Hwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.5
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    • pp.19-27
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    • 2013
  • This paper claims that the One Million-peyong Park(hereafter abbreviated as OMP) project is different from a typical citizen participatory park project by recognizing the exceptional leadership of the Civic Committee for the One Million-pyeong Park Construction(CCOMPC) in promoting and developing the OMP project. Since 2001 the CCOMPC has published a variety of written promotional materials to inform and educate the public about the project. In terms of approaching the promotional materials, this research focuses on the use of language on how the CCOMPC justifies the OMP project, namely the OMP justification discourse, and considers the discourse as a unique form of social document that represents the perspective of the CCOMPC in explaining the local environmental issues and values of urban parks to the public. Using a discourse analysis method, this research analyzes the justification discourses and investigates how they changed over the three main development phases of the OMP: the initiation and preliminary development phase(1999-2001.2), the development phase (2001.2-2008), and the time period after the greenbelt policy release on Dunchi Island(2008-present). In each discourse, the OMP project is rationalized as a citizen participation park project that (1) aims to enhance the quality of public green space in Busan, (2) is accompanied by various community engagement programs that emphasize the value of urban nature and environmental education to expand citizen participation, and (3) has contributed to the National Urban Park Bill. This research emphasizes the role of the discourses in helping the public gain a critical understanding about the local environment and values of urban parks. By analyzing the contents of the discourses, it explains the social learning values of the OMP expressed in the discourses.

High Dose Rate Interstitial Brachytherapy in Soft Tissue Sarcomas : Technical Aspect (연부조직종양에서 고선량율 조직내 방사선치료: 기술적 측면에서의 고찰)

  • Chun Mison;Kang Seunghee;Kim Byoung-Suck;Oh Young-Taek
    • Radiation Oncology Journal
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    • v.17 no.1
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    • pp.43-51
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    • 1999
  • Purpose : To discuss the technical aspect of interstitial brachytherapy including method of implant, insertion time of radioactive source, total radiation dose, and complication, we reviewed patients who had diagnoses of soft tissue sarcoma and were treated by conservative surgery, interstitial implant and external beam radiation therapy Materials and Methods : Between May 1995 and Dec. 1997, ten patients with primary or recurrent soft tissue sarcoma underwent surgical resection (wide margin excision) and received radiotherapy including interstitial brachytherapy. Catheters were placed with regular intervals of 1 ~l.5 cm immediately after tumor removal and covering the critical structures, such as neurovascular bundle or bone, with gelform, muscle, or tissue expander in the cases where the tumors were close to those structures. Brachytherapy consisted of high dose rate, iridium-192 implant which delivered 12~15 Gy to 1 cm distance from the center of source axis with 2~2.5 Gy/fraction, twice a day, starting on 6th day after the surgery, Within one month after the surgery, total dose of 50~55 Gy was delivered to the tumor bed with wide margin by the external beam radiotherapy. Results : All patients completed planned interstitial brachytherapy without acute side effects directly related with catheter implantation such as infection or bleeding. With median follow up duration of 25 months (range 12~41 months), no local recurrences were observed. And there was no severe form of chronic complication (RTOGIEORTC grade 3 or 4). Conclusion : The high dose rate interstitial brachytherapy is easy and safe way to minimize the radiation dose delivered to the adjacent normal tissue and to decrease radiation induced chronic morbidity such as fibrosis by reducing the total dose of external radiotherapy in the management of soft tissue sarcoma with conservative surgery.

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Development and Prey Consumption of Phytoseiid Mites, Amblyseius womersleyi, A. fallacis, and Typhlodromus occidentalis under controlled Environments (점박이응애 천적인 3종 이리응애의 발육 및 포식량 비교)

  • 권기면;이영인;이순원;최경희
    • Korean journal of applied entomology
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    • v.37 no.1
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    • pp.53-58
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    • 1998
  • Comparative studies on some ecological characteristics of three phytoseiid mitespecies (one native; Arnblyseius womersleyi Schica, and two introduced species; A. fallacis Garmanand Typhlodromus occidentalis Nesbit) were carried out. The two-spotted spider mite (Tetranychusurticae Koch) was supplied as prey. Under four constant temperatures of 20, 23, 25 and 30f OS$^{\circ}$C,duration of growth from egg to adult for A. womer.vleyi was 11.5, 7.7, 6.7 and 5.6 days. While twoother species needed slightly shorter time but not significantly different. Critical temperature andeffective degree-days (DD) of A. womerslevi females were 83$^{\circ}$C and 1 1 1.6 DD, whereas those of A..fallacis were 10.7"C and 86.0 DD, and those of 7: occidentalis were 10.7"C and 94.1 DD. Also, thoseof males were similar to their females. Average longevity of females of A. womersleyi, A. fallucisand 7: occidentalis were 18.2 k 8.67, 19.6 3~7.18 and 13.0f5.66 days, total fecundity were 34.3 $-11.93, 39.8k 12.64 and 23.6k8.86, respectively. Under four constant temperatures of 20, 23, 25 and30-t0.S$^{\circ}$C, A. womersleyi consumed 9.1 f2.49, 9.7 k2.00, 9.7 f 2.61, and 10.3 k2.33 eggs of 7:urticae throughout their development. A. ,fizlluc~i.sc onsumed 10.2 k 2.52, 9.7 f2.29, 10.7 f 2.37 and10.1 k2.62 eggs, while, 7: occidentalis consumed 1 1.9 k3.43, 14.2 f4.50, 14.8 k 3.2 1 and 12.7 f2.95 eggs, respectively. Gravid females of A. womersleyi, A. f~zllacis and 7: occidentalis consumed11.4f1.59, 12.5k1.43 and 11.7k3.07 eggs, or consumed 11.9f 2.63, 12.4k3.82, and 12.5f 3.73protonymphs of 7: urticae in a day at 25-30$^{\circ}$C.e in a day at 25-30$^{\circ}$C.

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Analysis on the Positional Accuracy of the Non-orthogonal Two-pair kV Imaging Systems for Real-time Tumor Tracking Using XCAT (XCAT를 이용한 실시간 종양 위치 추적을 위한 비직교 스테레오 엑스선 영상시스템에서의 위치 추정 정확도 분석에 관한 연구)

  • Jeong, Hanseong;Kim, Youngju;Oh, Ohsung;Lee, Seho;Jeon, Hosang;Lee, Seung Wook
    • Progress in Medical Physics
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    • v.26 no.3
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    • pp.143-152
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    • 2015
  • In this study, we aim to design the architecture of the kV imaging system for tumor tracking in the dual-head gantry system and analyze its accuracy by simulations. We established mathematical formulas and algorithms to track the tumor position with the two-pair kV imaging systems when they are in the non-orthogonal positions. The algorithms have been designed in the homogeneous coordinate framework and the position of the source and the detector coordinates are used to estimate the tumor position. 4D XCAT (4D extended cardiac-torso) software was used in the simulation to identify the influence of the angle between the two-pair kV imaging systems and the resolution of the detectors to the accuracy in the position estimation. A metal marker fiducial has been inserted in a numerical human phantom of XCAT and the kV projections were acquired at various angles and resolutions using CT projection software of the XCAT. As a result, a positional accuracy of less than about 1mm was achieved when the resolution of the detector is higher than 1.5 mm/pixel and the angle between the kV imaging systems is approximately between $90^{\circ}$ and $50^{\circ}$. When the resolution is lower than 1.5 mm/pixel, the positional errors were higher than 1mm and the error fluctuation by the angles was greater. The resolution of the detector was critical in the positional accuracy for the tumor tracking and determines the range for the acceptable angle range between the kV imaging systems. Also, we found that the positional accuracy analysis method using XCAT developed in this study is highly useful and will be a invaluable tool for further refined design of the kV imaging systems for tumor tracking systems.

A STUDY ON THE EFFECTS OF FINISHING/POLISHING TIMING ON SURFACE FEATURES OF COMPOSITE RESTORATION (연마시기에 따른 복합레진의 표면 특성에 관한 연구)

  • Yang, Kyu-Ho;Choi, Nam-Ki;Park, Eun-Hae;Lee, Young-Jun;Kim, Seon-Mi
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.1
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    • pp.98-107
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    • 2004
  • Proper finishing/polishing of dental restorations are critical clinical procedures that enhance both esthetics and longevity of restored teeth. This study was to compare the effects of immediate and delayed finishing/polishing procedures on the surface roughness and surface hardness of tooth-colored restoratives including two microfilled composite resins, such as Filtek A110 and Silux Plus, two hybrid composite resins, such as Revolution formular2 and Palfique Estelite. A total of 48 specimens were made for each material. The first 16 specimens served as the control group and the remaining 32 specimens were randomly divided into two equal groups. The control group was stored in distilled water at $37^{\circ}C$ for 1 week after light polymerization against the Mylar sheet. The first experimental group was finished/polished immediately after light polymerization and stored for 1 week in distilled water at $37^{\circ}C$, whereas the while the second group was finished/polished 1 week after light polymerization and stored in distilled water at $37^{\circ}C$. The results were as follows: 1. The smoothest surface was produced by Mylar sheet and finishing/polishing procedure increased the surface roughness. However, the surface roughness of composite resins were not influenced by the finishing/polishing timing. 2. There were significant differences about surface roughness between Revolution formular 2 and Silux Plus, regarding immediate finishing/polishing, and between Palfique Estelite and Silux Plus regarding delayed finishing/polishing(p<0.05). 3. The sequence of the surface hardness was ascending order by Revolution formular 2, Silux Plus, Filtek A110 and Palfique Estelite. However there were no significant differences about hardness among the control group and two finishing/polishing timing groups. 4. The effects of finishing/polishing time on surface roughness and hardness appeared to be material-dependent.

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A Study on the Consumer's Service Quality Perception Based on the Types of Life-style (소비자의 라이프스타일에 따른 서비스품질 지각 차이에 관한 연구)

  • Park, Yoon-Seo;Lee, Seung-In;Choi, In
    • Journal of Global Scholars of Marketing Science
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    • v.19 no.2
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    • pp.53-67
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    • 2009
  • For the last decades, service quality has been studied as one of the most important tools for a service company to compete with the other companies. Based on these past researches, it has been agreed that the service quality is a basic and powerful tool to create the competitive advantage. Due to similar reason, many service marketing practitioners have been also focused on the service quality to retain the existing consumers and collect the new consumers. However, service quality is subjectively perceived by individual consumers. Consumer evaluation of service quality can be different from each other. Especially consumers with one life-style may evaluate the service quality differently from the consumers with the other life-styles. Therefore we need to know whether there are differences in service quality perception on the categories of life-style. Life-style refers to a distinctive mode of living in its aggregate and broadest sense. It embodies the patterns that were developed and emerged from the dynamics of living in a society. Since the concept of life-style and its relationship to marketing was introduced in 1963 by William Lazer, methods of measuring the life-style and their application have been developed. Life-style has been usually used to segment the marketplace because it offers marketers a unique and important view of the market. When Life-style is combined with clustering methods, life-style segmentation can generate identifiable whole persons rather than isolated fragment. Life-style segmentation begins with people instead of products and classifies them into different life-style types, each characterized by a unique style of living based on a wide range of activities, interests, and opinions(Plummer, 1974). In this study we applies the life-style segmentation based on the AIO(Activities, Interests, and Opinions) to the consumers of the large discount stores. In Korea, the large discount store market has entered into maturity stage so that the market differentiation strategy is becoming a more critical issue to the marketing practitioners. One of the most important tools to differentiate from the competitors in large discount store market is continuously to provide service of better quality than competitors. This study tries to find answers about the following questions: 1) How can we categorize the consumer life-styles in the large discount store? 2) What are the characteristics of the categorized groups? 3) Are there any differences in service quality perception among the consumers with different life-styles 4) Are there any differences in consumer behavior among them in the large discount store? For the purpose, we collected survey data from consumers and analyzed the data with the SPSS package where we had $X^2$-test, factor analysis, ANOVA, MANOVA, and cluster analysis. The survey was made during one month in the April of 2008. Among the collected 306 copies of questionnaires, 281 copies were chosen as the effective samples for empirical analysis except 25 copies with wrong responses. To identify the life-style patterns, we used the measures employed by Kim and Kwon(1999), where 44 items on a seven-point scale were used to measure factors of the life-style patterns. The Principal Component Method was used for factor extraction, and the VARIMAX orthogonal factor rotation was employed. The 7 items showing low factor loading were eliminated. The results of the factor analysis suggested that nine factors of the life-style patterns were identified as follows: 1) the equality-of-sexes and pursuit-of-independence tendency 2) self-management tendency 3) sociable tendency 4) self-display tendency 5) degree of a dilettante life 6) pursuit-of-information tendency 7) bargain hunter tendency 8) TV preference tendency 9) pursuit-of-leisure tendency. Next, after the K-means cluster analysis was performed with nine factors of the life-style patterns, the life-styles of the respondents were classified into four groups which are named as the 'progressive practicality-oriented group', 'positive success-oriented group', 'sociable ostentation-oriented group', 'stable conservation-oriented group'. The analysis results for usage behavior between the market segments showed statistically significant differences in the frequency of usage, duration time in the store, consumer satisfaction, and loyalty. Also, we tried to investigate whether the large discount store consumers differently perceive the quality of service based upon the types of life-style. To measure the service quality of large discount store, we adapted several measurement models measuring the service quality such as SERVPERF, BCP, R-SERVPERF, R-BCP. MANOVA and One-Way ANOVA were performed to confirm the difference in service quality perception based on the market segments. The results have also shown significant differences between life-style types in service quality perception. These findings show that the large discount store marketers should consider consumer life-style as one of the most important market segments for marketing and understand the difference in service quality perception between life-style types. Our findings give important implications to marketers of large discount stores as well as life-style researchers. First, this study showed there were significant differences in consumer's service quality perception and usage behavior between the types of life-style. It provides evidence that the life-style approach can be a important basis in segmenting the large discount store market and will make consumers perceive the service quality high. Second, most previous researches on service quality have been in aggregate level. However, our results imply that the future research on service quality have to focus on segment level.

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Critical Analysis of Cultural Imperialism - From Simplistic Imperialism to Dynamic Cultural Fluid (문화제국주의의 비판적 고찰 - 단선적 문화제국주의에서 역동적인 국제적 문화 유동으로)

  • Yim, Dong-Uk
    • Korean journal of communication and information
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    • v.45
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    • pp.151-186
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    • 2009
  • This article focuses on analysing and interpreting cultural imperialism issues that have long been debated. One of issues among them is related to the characteristics of international cultural fluid. What had been debated is that cultural imperialism has been ended or not and the debates were connected to the so called 'reverse cultural imperialism'. The other issue is about this fluid is the continuation of globalization or a part of localization and this is related to the phenomena of cultural homogenization or hybrid. General trend was that simplistic cultural imperialism which had been occurred during the 1970s and 1980s was no longer effective but global dominance by transnational global media is still strong and worldwide. Therefore my research interest is centered on how they look international cultural exchanges with regard to cultural imperialism. And is the framework of cultural imperialism thesis still effective tool in researching and analysing international cultural flows? How do we look globalization relating to international exchanges? Is globalization an another aspect of imperialism? In conclusion, international cultural fluid is not so simple. Like natural phenomena or human progress, a phenomenon is not consisted of a single factor or relation. Cultural fluid is a complex one mixed with various phenomena and relations. This is related to internal and external contradictions, internal and external dynamics of a society and nation, and social and cultural life of human beings. Recent research results show that globalization and localization are closely related to many country's programming schedule, and particular cultural interpretation of specific programmes and culture are adopted to the country's culture and patterns. Cultural fluid has both-sides. One the hand it has useful and positive sides and on the other hand it has harmful and negative aspects. Imperialistic factor, globalization, cultural homogenization or hybrid are all operated and functioned together in cultual fluid. It is difficult to say that cultural imperialism thesis has been ended because American and global media's dominance is still effective. What needed at this time for us is a complex and dynamic analysis of international cultural fluid instead of simplistic cultural imperialism.

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Effects of SSI Argumentation Program based on SEL for Preservice Biology Teachers (예비 생물교사를 위한 사회정서학습에 기반한 SSI 논증 프로그램 적용 효과 탐색)

  • Kim, Sun Young;Kim, Su Hyeon
    • Journal of The Korean Association For Science Education
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    • v.38 no.2
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    • pp.259-271
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    • 2018
  • This study examined the effect of the SSI argumentation program based on social and emotional learning(SEL). The program consisted of 3 stages: (1) express their own feelings about SSI, identify the issues of SSI, and define a goal; (2) think of many possible solutions and envision results through argumentation; (3) select the best solution and make a decision based on warrants, data, and rebuttals. In each stage, the social-emotional strategies of self-awareness, self-management, social-awareness, relationship-management, and responsible decision making were used. Seventeen preservice biology teachers participated in this study during one semester dealing with four socioscientific issues. The results indicated that the preservice teachers, as time went on, became accustomed to expressing identifiable rebuttals, dispute talk, and asking questions. At the first SSI argumentation, argumentation mainly consisted of cumulative talk with no rebuttals, representing level 2 argumentation. Level 3 argumentation represented rebuttals that were implicit and weak, with cumulative talk. In level 2 and 3 argumentation, the preservice teachers represented understanding of others and compassion for self and others. Level 4 argumentation had rebuttals that were explicit, asking critical questions of the opposite sides. In addition, level 5 argumentation represented more than two controversial points with several instances of dispute talk. In levels 4 and 5, the preservice teachers became actively engaged in communication, inquiry self with others, managing vulnerability and negotiation.